Science 9.10.2020

CONTENTS

9 OCTOBER 2020 • VOLUME 370 • ISSUE 6513

As COVID-19 cases climbed in May, Stockholm remained busy—and largely maskless. 159

PHOTO: BLOOMBERG/GETTY IMAGES NEWS F E AT U R E S 170 Layer-cake 2D superconductivity
An easy-to-synthesize quantum material may
IN BRIEF 159 Sweden’s gamble help unveil quantum effects By L. M. Schoop
The country’s pandemic policies came
150 News at a glance at a high price—and created painful rifts REPORT p. 231
in its scientific community
IN DEPTH 171 Better, faster, and even cheap
By G. Vogel An inexpensive gold grid with submicrometer
153 Astronomy is—and has— holes minimizes protein sample
a climate problem INSIGHTS movement By M. Rapp and B. Carragher
Big carbon footprints and rising
vulnerabilities push astronomers to take PERSPECTIVES REPORT p. 223
action By D. Clery
164 Novel communities are a risky 172 Contextualizing bats as viral reservoirs
154 A call to test new vaccines head business Preventing zoonotic emergence
to head, in monkeys High turnover leads to novel combinations from bats requires integrative research
Proposed comparison study could clarify of species and involves high extinction
safety and which vaccines work best By D. G. Streicker and A. T. Gilbert
By M. Dornelas and J. S. Madin
By J. Cohen POLICY FORUM
REPORT p. 220
156 With to-do list checked off, 174 U.S. policy puts the safe development
U.S. physicists ask, ‘What’s next?’ 166 Making a bed for viral infections of space at risk
Giant neutrino experiment is only sure thing An inflamed mucosal niche is Promoting national regulation of space
for the field By A. Cho permissive for symptomatic respiratory mining rather than multilateral governance risks
syncytial virus infection a “race to the bottom” By A. Boley and M. Byers
157 Newly found viruses
suggest rubella originated in animals By A. S. Mirchandani and S. R. Walmsley BOOKS ET AL.
Two relatives discovered in bats, mice, and
zoo animals suggest “German measles” RESEARCH ARTICLE p. 188 177 Plotting a path to a more
jumped the species barrier By A. Gibbons sustainable future
167 Inhibiting Ebola virus and Persistent political pressure staves off global
158 NASA mission set to sample SARS-CoV-2 entry warming in a new climate allegory
carbon-rich asteroid Screening identifies CD74 as a cellular
Bennu’s thick carbonate veins suggest past antiviral protein against Ebola virus and By C. Abbott
life as a water world By P. Voosen SARS-CoV-2
178 Moving beyond buzzwords
10.1126/SCIENCE.ABC3660; 10.1126/SCIENCE. By A. I. Wells and C. B. Coyne Rejecting conventional connotations, two
ABC3522; 10.1126/SCIENCE.ABC3557; 10.1126/ books urge readers to rethink innovation
SCIADV.ABC3550; 10.1126/SCIADV.ABD3649; REPORT p. 241
10.1126/SCIADV.ABC3699 By D. Greenbaum and M. Gerstein
168 A new villain in neuronal death
SCIENCE sciencemag.org A newly discovered partnership for LETTERS
glutamate triggers brain toxicity By S. Jones
179 Retraction
RESEARCH ARTICLE p. 191
By Y. Wu et al.
Published by AAAS
9 OCTOBER 2020 • VOL 370 ISSUE 6513 145

CONTENTS

PHOTO: M. I. WALKER/SCIENCE SOURCE 179 Hidden ethical costs of conservation 188 Viral infections 223 Electron microscopy
Neutrophilic inflammation in the Cryo-EM with sub–1 Å specimen
By K. E. Lynch and D. T. Blumstein respiratory mucosa predisposes to RSV movement K. Naydenova et al.
infection M. S. Habibi et al.
180 Pragmatic animal welfare is PERSPECTIVE p. 171
independent of feelings RESEARCH ARTICLE SUMMARY; FOR FULL TEXT:
DX.DOI.ORG/10.1126/SCIENCE.ABA9301 227 Plant science
By R. Arlinghaus et al. PERSPECTIVE p. 166 WUSCHEL triggers innate antiviral immunity
in plant stem cells H. Wu et al.
180 Animal welfare science aids 189 Structural biology
conservation Conformational states dynamically 231 Superconductivity
populated by a kinase determine Clean 2D superconductivity in a bulk van der
By J. O. Hampton et al. its function T. Xie et al. Waals superlattice A. Devarakonda et al.

181 Response RESEARCH ARTICLE SUMMARY; FOR FULL TEXT: PERSPECTIVE p. 170
DX.DOI.ORG/10.1126/SCIENCE.ABC2754
By N. Sekar and D. Shiller 237 Vaccines
190 Metallurgy Influenza vaccine–induced human bone
181 Techincal comment abstracts The heterogeneity of persistent slip band marrow plasma cells decline within a year
nucleation and evolution in metals at the after vaccination C. W. Davis et al.
164 & 220 micrometer scale S. Lavenstein et al.
241 Coronavirus
RESEARCH RESEARCH ARTICLE SUMMARY; FOR FULL TEXT: MHC class II transactivator CIITA induces
DX.DOI.ORG/10.1126/SCIENCE.ABB2690 cell resistance to Ebola virus and
IN BRIEF SARS-like coronaviruses A. Bruchez et al.
191 Neuroscience
182 From Science and other journals Coupling of NMDA receptors and PERSPECTIVE p. 167
TRPM4 guides discovery of unconventional
REVIEW neuroprotectants J. Yan et al. 247 Neuroscience
Alternating sequences of future and
185 Biotechnology RESEARCH ARTICLE SUMMARY; FOR FULL TEXT: past behavior encoded within hippocampal
Bioengineered human blood vessels DX.DOI.ORG/10.1126/SCIENCE.AAY3302 theta oscillations M. Wang et al.
PERSPECTIVE p. 168
L. E. Niklason and J. H. Lawson D E PA R T M E N T S
192 Batteries
REVIEW SUMMARY; FOR FULL TEXT: Black phosphorus composites with 149 Editorial
DX.DOI.ORG/10.1126/SCIENCE.AAW8682 engineered interfaces for high-rate Here today, gone tomorrow
high-capacity lithium storage H. Jin et al.
186 Electrochemistry By Peter H. Raven and Scott E. Miller
Recent advances in solid oxide cell 198 Quantum gravity
technology for electrolysis A. Hauch et al. Spacetime from bits M. Van Raamsdonk 258 Working Life
A pandemic journey By Sergio E. Ramos
REVIEW SUMMARY; FOR FULL TEXT: 203 Coronavirus
DX.DOI.ORG/10.1126/SCIENCE.ABA6118 In situ structural analysis of ON THE COVER
SARS-CoV-2 spike reveals flexibility
RESEARCH ARTICLES mediated by three hinges The spike protein (teal), covered in pro-
B. Turoňová et al. tective glycan molecules, on the surface
187 HIV of SARS-CoV-2 is the primary target for
Reconstitution and visualization of HIV-1 208 Developmental biology COVID-19 vaccine development. The spike
capsid-dependent replication and integration The mole genome reveals regulatory contains three hinges that enable it to be
in vitro D. E. Christensen et al. rearrangements associated highly flexible on the viral surface and may
with adaptive intersexuality facilitate host cell entry. The spike positions
RESEARCH ARTICLE SUMMARY; FOR FULL TEXT: F. M. Real et al.
DX.DOI.ORG/10.1126/SCIENCE.ABC8420 shown here are from
REPORTS structural data of intact
SARS-CoV-2 virions. See
214 Organic chemistry page 203. Illustration: V.
Electro-inductive effect: Electrodes as Altounian/Science; Data:
functional groups with tunable electronic Paul Ehrlich Institute,
properties J. Heo et al. European Molecular Biology
Laboratory, and Max Planck
220 Novel communities Institute of Biophysics
Increased extinction in the emergence
of novel ecological communities Science Staff .............................................. 148
J. M. Pandolfi et al. New Products.............................................254
Science Careers .........................................255
PERSPECTIVE p. 164

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SCIENCE sciencemag.org 9 OCTOBER 2020 • VOL 370 ISSUE 6513 147

Published by AAAS

EDITORIAL

Words matter

H. Holden Thorp F or more than 200 years, U.S. presidents have science he has long undermined. The experimental an-
Editor-in-Chief, strived to deliver words of inspiration and humility tibody cocktail that he is taking is the fruit of a gar-
Science Journals. that will stand the test of time. Even in a conten- gantuan effort by scientists fighting hard to understand
[email protected]; tious debate in which the Oval Office is at stake, the viral spike protein and characteristics of the most
@hholdenthorp we expect a standing president to inspire and unite potent neutralizing antibodies. That effort stands on
the country. Not surprisingly, President Donald the shoulders of decades of fundamental research in
Trump used the occasion of the first presidential immunology and structural biology, science that Trump
debate of 2020 to deny reality, insult his opponent, and has insulted and devalued by cutting funding for the
praise himself—all with his customary lean vocabulary. National Institutes of Health in every budget he has
submitted, but even more so with his words. Words that
Over the ages, U.S. presidents have pored over parch- criticized science for discouraging use of hydroxychlo-
ment, legal pads, and laptops to create the scripture of the roquine, a drug that he is not taking now that he has
nation: “…the only thing we have to fear is…fear itself,” “a COVID-19. Words that discouraged public health inter-
date which will live in infamy,” “ask not what your coun- ventions that cost lives and led directly to his own su-
try can do for you…,” and “Mr. Gorbachev, tear down this perspreader event in the White House’s Rose Garden.
wall” resonate ever stronger over time. Words that painted career scientists at the Food and
Drug Administration, who have devoted their lives to
There are no such inspiring words today. President protecting the public’s health, as the “deep state.” And
Trump has no interest in lifting up Americans or the words that implied that the only reason scientists were
rest of the world. He only wants to bring society down working so hard was because of his compelling exhor-
with his rhetorical carnage. During the past 4 years we’ve tations to do him a favor and speed it up. A speedy re-
heard “very fine people, on both sides,” “I need loyalty,” covery is hoped for President Trump and everyone who
and “shithole countries.” And from the debate stage, he is battling this disease, as science strives to provide an
told one group of militant right-wing thugs to “stand back effective vaccine.
and stand by,” as if he was asking them to cool it for now
while awaiting further orders. Those of us who live in Washington, DC, are sur-
rounded by the words that define America. We can go
When it comes to the crisis of coronavirus disease 2019 on long walks to the World War II Memorial, along the
(COVID-19), Trump’s words could not be more destruc- Reflecting Pool, and up the steps of the Lincoln Memo-
tive. When scientists tried to tell him a crisis was com- rial. We can stand where Dr. Martin Luther King Jr. said,
ing, he called it “their new hoax.” About the extraordinary “I have a dream.” And we can see chiseled into marble
number of lives lost he says, “it is what it is.” His plan the words of Abraham Lincoln: “Let us strive on to finish
for conquering the virus is simply that “like a miracle, it the work we are in; to bind up the nation’s wounds; to
will disappear.” His communications strategy is “I always care for him who shall have borne the battle, and for his
wanted to play it down.” And as for his role as the leader widow, and his orphan—to do all which may achieve and
of a country in crisis, he says, “No, I don’t take respon- cherish a just and lasting peace, among ourselves, and
sibility at all.” It’s safe to say that Presidents Roosevelt, with all nations.”
Kennedy, and Reagan would have said something more
comforting and profound. By now, we know that we will not get such uplifting
rhetoric from Donald Trump. For the scientists and many
His words are particularly painful for science. Long others who have made sacrifices to fight this pandemic,
days and nights have been spent by scientists working at we’d settle for just two words. Two words he has a hard
the bench, fighting to understand the causative virus and time saying. Two words that he has rarely said to the vac-
methods to defeat it. Epidemiologists have been analyz- cine scientists who have worked 18-hour days, their kids
ing their models trying to devise mitigations. Physician- out of school and family members affected by the pan-
scientists and their colleagues in academic hospitals demic. Or to the health care workers, their faces raw from
have developed new approaches to bring down the death their protective masks and their souls crushed because
rate substantially. And through all this, these research- they are living in self-isolation to protect their families,
ers rarely have heard one word of acknowledgment from who have labored in the wards to bring down the death
their president. It’s no wonder that the braggart who said, rate. Two words that he says now, only because he has
“I alone can fix it” can’t bring himself to admit that he been diagnosed with COVID-19 himself. Two words he
is not the person who will get us through the pandemic. should say constantly to those who have borne the battle
Even with the vaccine that so many have worked toward, of COVID-19. Two words Donald Trump struggles to say:
Trump has manufactured a rationale by which he is the “Thank you.”
one who deserves the credit.
–H. Holden Thorp*
Now that Trump himself has been diagnosed with
COVID-19, he is seeing first-hand the benefits of the

*Editor’s note: An earlier version of this editorial was published online as 10.1126/science.abf0577
“Two words Trump can’t say” prior to the president’s diagnosis of COVID-19.

148 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

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Here today, gone tomorrow

W e are destroying the life-support systems out to be all that remains of organisms that once thrived. Peter H. Raven
of Earth rapidly, making our future uncer- Faced with this grave future, we must find ways to is president
tain. Ecosystems—the complex sets of or- emeritus of the
ganisms that form the globe’s living land- preserve these specimens as well as we can for as long Missouri Botanical
scape—regulate the atmosphere, water, and as we can. They are vulnerable to degradation and loss Garden, St. Louis,
soils. They supply humanity its food, most from pests, humidity, fire, and the simple ravages of MO, USA. peter.
time. While renewing efforts to protect them, we need [email protected]

medicines, and many other essential prod- to make them more accessible through digitization, in- Scott E. Miller
is the chief scientist,
ucts, and they fill our lives with beauty. But they are cluding imaging and DNA barcoding (at least a mini- and interim director
of Smithsonian
falling apart as, one by one, their constituent species mal DNA sequence of the representative specimens). Libraries,
Smithsonian
are lost. To save what we can and provide our children We also need to continue targeted sampling, focused Institution,
Washington, D.C.,
and grandchildren with a sustainable future, studies on key taxa and habitats. USA. [email protected]

must be conducted not only in nature but also, to an in- Some groups of great ecological and environmental

creasing extent, on the billions of specimens preserved importance are dying off too rapidly to ever be com-

in the world’s natural history collections. For many spe- pletely understood. We have named 25,000 species of

cies barely hanging on in their endan- nematodes, 64,000 species of mites,

gered habitats, these samples will one and 100,000 species of fungi. Yet each

day be all that we have. “…we are of these groups is estimated to con-
Last week’s United Nations Summit sist of a million or more species, with

on Biodiversity discussed earlier re- in danger the number of fungi likely to be 2.2
ports that perhaps 1 million of the es- to 2.6 million. We must sample them

timated 8.5 million species of plants, of losing 80% and understand them as well as we
animals, and other organisms are in can before many of their species dis-

imminent danger of extinction. Prob- or more appear forever.
ably as many as half of the popula- of the world’s To do all of this, we need many
tions of organisms that existed half a species…”
century ago are already gone. Over the more specialists in all regions of the
past quarter century, about a quarter world who are trained in advanced
of all tropical forests have been lost. methods for collecting and preserv-
Because we have identified no more ing specimens, and in the exciting
new field of “museomics”—determin-

than a tenth of the estimated tens of ing DNA sequences from old pre-

thousands of species in those habi- served specimens. The standards for

tats, most that were lost may forever remain unknown. the best preservation and training established by the

Unless we control the underlying causes, including International Society for Biological and Environmen-

overdevelopment and climate change, we are in dan- tal Repositories may help point the way.

ger of losing 80% or more of the world’s species, the Many of the world’s biological collections are in insti-

proportion lost 66 million years ago when the dino- tutions that depend in part on attendance for their sup-

saurs became extinct and many of the plants and ani- port. In this time of coronavirus disease 2019 (COVID-19),

mals known today began their ascent. We have clearly many of them will fail financially or be unable to con-

entered the world’s sixth major extinction event. tinue maintaining their own collections. These and

While we work to forestall this destruction, we must other potentially “orphan” collections have immense

treat the specimens in our collections with ever more value and should be monitored and incorporated as

care. They are no longer simply samples of wild pop- needed into permanent homes. This is likely to be our

ulations from which more will always be available. As last chance to know many of Earth’s species. We must

many as half of the specimens likely represent popula- make the most of it.

tions that no longer exist, and an increasing number of

species as well. What is in our collections will often turn –Peter H. Raven and Scott E. Miller

SCIENCE sciencemag.org 10.1126/science.abf1185
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NEWS “ ”Very few don’t have some sort of connection to Big Tech.
Doctoral student Mohamed Abdalla, in Wired, about a study he led of faculty members specializing
IN BRIEF in artificial intelligence at four leading research universities. He found 58% (48 of 83) had received a grant or

Edited by fellowship from one of 14 large technology companies, which may distort research priorities.
Jeffrey Brainard
President Donald Trump
removes his mask on

a White House balcony
after returning from
his stay at the Walter

Reed National Military
Medical Center.

POLITICS

Trump’s brief hospitalization for COVID-19 follows bitter debate

T he U.S. presidential race was upended in the first days rancorous first debate on 29 September between Trump and PHOTO: ANNA MONEYMAKER/THE NEW YORK TIMES/REDUX PICTURES
of October as President Donald Trump tested positive Democratic challenger Joe Biden. Trump mocked Biden for
for the pandemic virus and spent 3 days in the hospi- having worn a mask at other times, despite evidence that the
tal. He was aggressively treated with two experimental precaution reduces transmission of the virus. The president
medicines—monoclonal antibodies and the repurposed also left scientists puzzled when he described as a “disaster”
antiviral remdesivir—and a steroid used in severe Biden’s role in the response to the H1N1 swine flu out-
COVID-19 cases. Trump returned to the White House on break in 2009. Then-President Barack Obama, whom Biden
5 October saying people should not fear the disease. But pub- served under as vice president, declared it a public health
lic health specialists voiced astonishment when he re-entered emergency 6 weeks before the World Health Organization
the building maskless, trailed by questions about his medical declared a pandemic. That flu killed an estimated 12,000
condition and a lack of information about how staff mem- Americans—far fewer than the 210,000 U.S. deaths recorded
bers would be protected from infection. All that followed a so far from COVID-19.

CDC’s COVID-19 advice faulted an order barring cruise ships from sailing pandemic virus. The agency recommended
despite a recommendation by its director, different frequencies of testing, including
PU B L I C H E A LT H | Coronavirus guidelines Robert Redfield, to extend the ban until just a single, initial one, depending on
issued last week by the U.S. Centers for February 2021. The industry shut down in circumstances such as whether students
Disease Control and Prevention (CDC) March after severe COVID-19 outbreaks lived in residences with others who tested
again stirred controversy and con- occurred on multiple ships. Last week, positive. Critics said the new guidelines
cerns that undue political pressure had CDC also drew fire for its updated guide- should have recommended more regular
influenced some of its decisions. CDC lines on when colleges should test students testing of asymptomatic individuals. CDC
announced that on 31 October it will lift and faculty and staff members for the addressed another uproar this week by

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acknowledging evidence that the virus can THE NOBEL PRIZES
travel by air and infect people standing
more than 2 meters apart in indoor spaces.
The agency was faulted last month after it
posted, and then withdrew, a draft suggest-
ing otherwise.

U.S. launches zoonosis project Researchers isolated the hepatitis C virus (shown), leading to a safer blood supply and life-saving treatments.

I N F ECT I O U S D I S E AS E S | An interna- Medicine prize goes to discoverers of virus that destroys the liver
tional program to reduce the risk of new
zoonotic diseases, allowed to expire by The Nobel Prize in Physiology or Medicine was awarded this week for the discovery of the
the U.S. government in 2019 but extended hepatitis C virus, one of the most common causes of liver cancer. The prize went to Harvey
until last month, will get a successor. On Alter of the U.S. National Institutes of Health; Michael Houghton of the University of Alberta,
30 September, the United States Agency Edmonton; and Charles Rice of Rockefeller University.
for International Development (USAID)
awarded a $100 million grant to help The hepatitis C virus, transmitted via blood, can cause chronic inflammation of the liver
countries in Asia and Africa curb viruses that quietly destroys the organ over decades, ultimately leading to cirrhosis and cancer.
jumping from animals to humans. The The laureates did work over 3 decades to identify the virus and show it was responsible
5-year Strategies to Prevent Spillover pro- for unexplained cases of hepatitis in people who received blood transfusions. They also
gram will have a different focus from its developed a test to screen blood donations for the virus, which has nearly eliminated the risk
predecessor, PREDICT, whose termination of hepatitis from blood transfusions. Their research ultimately led to a successful treatment
was criticized by the scientific community: for the disease, which has cured millions of people. But about 71 million people worldwide still
Rather than studying the drivers of spill- have chronic hepatitis C, and transmission continues via contaminated medical equipment,
over, it will seek interventions to reduce sharing drug injection needles, and from infected mothers to newborns during birth. The
viral jumps, a USAID spokesperson says. A disease causes few acute symptoms, and testing in many developing countries is limited.
key goal is to “help partners at the country
level build their expertise and ability to Black hole hunters receive physics prize
take action,” says veterinarian Deborah
Kochevar of Tufts University, which leads a The Nobel Prize in Physics has been awarded for pioneering discoveries regarding black
13-institute consortium that won the grant. holes—self-sustaining gravitational fields so intense that nothing, not even light, can escape.

Top Soviet-era dissident dies Roger Penrose, a mathematician at the University of Oxford, received half of the $1.1 million
prize for his theoretical work, conducted in part with the late Stephen Hawking, that proved
I N T E R N AT I O N A L A F FA I R S | Yuri Orlov, a black hole would be stable and thus could be a real astrophysical object and not a
the Russian physicist who champi- mere mathematical curiosity. Astronomers Reinhard Genzel of the Max Planck Institute for
oned human rights in the Soviet Union Extraterrestrial Physics and Andrea Ghez of the University of California, Los Angeles, share
before being exiled in 1985, died on the other half of the prize for deducing the presence of the supermassive black hole that
27 September at age 96. Orlov helped lies in the heart of our Galaxy. Since the 1990s, Genzel and Ghez have led rival research
organize the Soviet Union’s branch of groups that observed stars there, 26,000 light-years from Earth. They found ones orbiting
Amnesty International in 1973 and 3 years a heavy, unseen object, called Sagittarius A*, at incredible speeds—some of the most
later co-founded the Moscow Helsinki convincing evidence for a behemoth black hole, with the mass of millions of Suns.
Group, which monitored Soviet adher-
ence to the civil rights provisions of the
1975 Helsinki Accords between the Soviet
Union and the West. In 1977, Orlov was
arrested and sentenced to 12 years of hard
labor and exile in Siberia. After coming to
the United States in a prisoner exchange,
Orlov, an expert in particle accelerators,
worked at Cornell University. He didn’t
think much of Russian President Vladimir
Putin, writing in 2004 that “Russia is fly-
ing backward in time.”

PHOTO: JAMES CAVALLINI/SCIENCE SOURCE Japan leader blocks appointments freedom. SCJ makes policy recommenda- withheld his blessing from six academics,
tions, promotes scientific literacy and in a list of 105 put forward, who work in
G OV E R N A N C E | Japan’s new prime min- international cooperation, and represents the social sciences, law, and the humanities.
ister, Yoshihide Suga, has disrupted the the interests of more than 800,000 scholars All six had criticized legislation adopted by
process by which scientists are appointed to in virtually all academic disciplines. The Japan’s previous government, in which Suga
serve on the governing body of the coun- prime minister customarily ratifies appoin- was chief cabinet secretary. His failure to
try’s leading academic society, the Science tees recommended by SCJ for its governing appoint them violated a law governing SCJ,
Council of Japan (SCJ). Researchers are body, the General Assembly. But accord- said Satoshi Ihara, secretary general of the
criticizing the move as a threat to academic ing to an announcement last week, Suga Japan Scientists’ Association.

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NEWS | IN BRIEF

Mexico axes science funds On 6 October, Mexico’s Chamber of Deputies reported on 30 September that they had
approved a bill to terminate the funds, but found the virus in a woman from the
POLICY | Mexican scientists this week with “reservations” that require further Fairbanks area with a mild, gray skin lesion
blasted a move by the national legislature debate; it is expected to pass in the Senate. on one arm, similar to one seen in 2015 in
to eliminate 109 trust funds run by public The plan is “a brutal blow” and the worst hit the first known patient, also a woman from
research centers and government institutes, to Mexican science in 50 years, says Antonio Fairbanks. Human infections with pox-
one-third of them devoted to science and Lazcano, an evolutionary biologist at the viruses are on the rise, presumably because
technology. The government wants to use National Autonomous University of Mexico, vaccination against smallpox—which offers
the money, some $3 billion in total, for the University City. some protection against related viruses—
coronavirus pandemic. The funds support was halted after that deadly disease was
everything from student scholarships and Rare poxvirus found in Alaska eradicated 40 years ago. But the Alaska
emergency maintenance of equipment to cases are no cause for alarm: There is no
major research projects at dozens of govern- VIROLOGY | There’s been a new case of evidence the virus can be transmitted
ment centers. The money also helps pay infection with Alaskapox virus, a recently between humans—scientists think it came
for biosecurity and biotechnology research, discovered pathogen that’s related to from wild mammals—and the lesions went
fighting climate change, and disaster relief. smallpox. Alaska state health authorities away by themselves.

Olive ridley sea turtle hatchlings creep FEATURED INTERVIEW
seaward just after emerging from eggs
Fauci: ‘Skunk at the picnic’
on Costa Rica’s Pacific Coast.
On 23 September, in the relative calm
C O N S E R VAT I O N before President Donald Trump’s PHOTOS: (TOP TO BOTTOM) INGO ARNDT/MINDEN PICTURES; HELEN PHEASLEY
coronavirus infection was revealed,
Spy eggs help track Anthony Fauci relaxed at home after
turtle poaching tangling earlier that day with U.S. Senator
Rand Paul (R–KY) during a hearing on
High-tech fake turtle eggs can spy on poachers and wildlife trafficking routes. The real COVID-19. Fauci still had 200 emails in
eggs are a delicacy in Central America, and illicit trading of them adds to other hazards his inbox to read that night, but the head
to the survival of turtle species that are threatened. Researchers slipped 101 decoy of the National Institute of Allergy and
Infectious Diseases, who also serves
eggs with GPS trackers embedded (left) into nests on four Costa on the White House’s Coronavirus Task
Rican beaches. The scientists tracked five eggs to learn where the Force, sat down with Science to discuss
poachers took them; the farthest ended up 137 kilometers the pandemic and research on vaccines.
inland, the multinational team reported on 5 October in (Read the full interview at scim.ag/
Current Biology. The researchers did not share this informa- FauciOctober.) Some excerpts:
tion with authorities, noting ethical concerns; many poachers
live in poverty, and in Costa Rica, buying the eggs is not On his showdown with Paul: “I said to
illegal. But, the authors say, the study shows that law enforce- myself, you know, ‘I’m sorry, I’m not
ment agencies could use the method. gonna disrespect him, but I’m not gonna
let him get away with saying things
152 9 OCTOBER 2020 • VOL 370 ISSUE 6513 that are cherry-picked data.’” (Paul had
suggested that the United States follow
Sweden’s COVID-19 policies because it
had a lower death rate from the disease.)

On speaking bluntly at the White
House: “I’m walking a fne line of being
someone who is not hesitant to tell the
president and the vice president what
they may not want to hear. There are
some people in the White House, who,
even when I frst started telling it like
it was in the task force meetings, they
were like, ‘Oh my goodness.’ That’s when
I got that nickname ‘the skunk at the
picnic.’ ... I say, ‘I’m sorry, I’m not trying
to undermine the president. But there is
something that’s called reality.’”

On the state of the pandemic: “Yes, there
are parts of the country that are doing
well. But this country is a big forest, and
when you have fres in some parts of the
forest, the entire forest is at risk.”

sciencemag.org SCIENCE

Published by AAAS

IN DEPTH

In August, raging fires in California destroyed buildings at the Lick Observatory but spared telescopes.

CLIMATE CHANGE

Astronomy is—and has—a climate problem

Big carbon footprints and rising vulnerabilities push astronomers to take action

PHOTO: ELINOR GATES/UCO/LICK OBSERVATORY By Daniel Clery Those concerns were cast in sharp relief emissions overall (18 tons per astronomer),
by six papers published last month in Na- to which flights were the biggest contributor.
I n August, as wildfires crept close to the ture Astronomy. One, on the carbon costs The authors say the greater use of renewable
historic Lick Observatory near San Jose, of meetings, emerged directly from the energy in Germany may explain some of that
California, Claire Max watched as live 2019 European Astronomical Society (EAS) difference, but the MPIA astronomers still
webcams showed flames edging toward meeting in France, which took place dur- generated three times the emissions of a typi-
observatory buildings and several tele- ing a record-breaking heat wave when tem- cal German.
scopes. In the end, firefighters kept the peratures exceeded 45°C. “We were sitting
flames at bay. Although two unused build- with no air conditioning, sweating through The climate that astronomers are help-
ings were destroyed and several houses were all these interesting talks,” Burtscher says. ing warm is in turn threatening their view
damaged, the working telescopes only had a Discussions turned to climate change and of the sky. In another of the papers, MPIA’s
bit of ash on the mirrors. “We really lucked the carbon emitted getting everyone to the Faustine Cantalloube and colleagues went
out,” says Max, director of the University of meeting, and they inspired Burtscher and through 30 years of weather records from
California Observatories, which runs Lick. his colleagues to size up the meeting’s travel the Paranal Observatory in Chile, operated
Coastal California has always experienced emissions. They added up to nearly 1900 by the European Southern Observatory
cycles of drought and fire, she says. “But it’s tons of carbon dioxide (CO ) equivalent or (ESO). They found average temperatures
perfectly plausible for people to say global there had risen by 1.5°C, more than the 1°C
warming didn’t make it any better.” 2 average global rise since preindustrial times.
Cantalloube says that’s already causing trou-
Astronomers have a climate problem. about 1.5 tons per delegate—roughly the ble for Paranal’s Very Large Telescope—four
Not only is global warming increasing the same as emitted by an average resident of separate 8.2-meter reflectors. During the day,
frequency of wildfires and the strength of India in a whole year. cooling systems kick in to keep temperatures
hurricanes that physically threaten obser- inside the telescope domes the same as that
vatories, but a changing climate could mar Other fields of science doubtless generate of exterior air at sunset, to avoid temperature
their views by bringing higher tempera- similar emissions from large meetings, but differences that create turbulence when the
tures, humidity, and turbulent air closer astronomers’ work habits are carbon heavy dome is opened. When daytime temperatures
to their mountaintop perches. Astrono- as well. Another of the six studies found exceed 16°C, the system struggles. “The dome
mers are also adding to the climate prob- that Australian astronomers each produced cooling is not good enough,” Cantalloube
lem themselves, with long flights to remote 37 tons of CO equivalent per year, of which says. “At the time it was built in the 1990s,
facilities and meetings and heavy use of we were not thinking that [the temperatures]
energy-hungry supercomputers for cosmic 2 would be so high by 2020.”
simulations. “We’re part of the problem,
not of the solution,” says Leo Burtscher of 60% came from supercomputer usage. “We The hike in temperature has also in-
Leiden University. were surprised how big the supercomputers creased turbulence in the surface layer, the
were. Everyone thought flights would domi- air a few tens of meters above the telescopes.
nate,” says lead author Adam Stevens of the
University of Western Australia, Perth. A sim-
ilar analysis in Nature Astronomy of the 2018
emissions from Germany’s Max Planck In-
stitute for Astronomy (MPIA) showed lower

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NEWS | IN DEPTH

Surface layer turbulence has risen since the near Paranal. The Keck and Gemini tele- COVID-19
1980s, the researchers found, and although it scopes in Hawaii and the Murchison Radio-
hasn’t yet affected observing, it is worrying, astronomy Observatory in Australia have A call to test
Cantalloube says. “There is clearly something installed solar arrays, too. To cut down on new vaccines
going on very close to the ground,” she says. flying, more and more telescopes are mak- head to head,
ing remote observing routine. Max says in monkeys
A hotter climate is expected to raise hu- the University of California built remote
midity levels as well, which can lead to in- observing rooms on its far-flung campuses Proposed comparison study
creased cloud cover—an obvious problem so researchers didn’t need to travel to Lick could clarify safety and
for astronomers. The water vapor itself can and other telescopes. Since the arrival of which vaccines work best
block infrared and microwave radiation, COVID-19, the scheme has been extended
the focus of the Atacama Large Millimeter/ to home laptops—“pajama observing,” Max By Jon Cohen
submillimeter Array (ALMA), also in Chile. calls it. “The days of flying to Hawaii to ob-
So far, moisture has not increased at Paranal, serve are numbered,” she says. P rimate researchers in the United
Cantalloube’s analysis shows, or at ALMA, ac- States have banded together in a
cording to a separate study. Climate models Meetings are another target ripe for re- push for an ambitious monkey study
are not yet fine-grained enough to predict form. “There’s a lot of excitement about that would do head-to-head compari-
future moisture trends at the observatories. the potential” of virtual meetings, says sons of the leading COVID-19 vaccine
“We will have to see if climate change will Travis Rector of the University of Alaska, candidates. Although 10 candidates
drive more humidity into the region,” says Anchorage, who heads the sustainability are already undergoing large-scale tests
ESO atmospheric scientist Angel Otárola. committee of the American Astronomical in people, proponents of the monkey plan
Society (AAS). When this year’s EAS meet- say those clinical trials may not deliver the
Astronomers are now taking steps to re- ing went virtual because of COVID-19, the comprehensive data needed to choose the
duce their carbon footprint. In another of the team that calculated the carbon costs of the safest and most effective vaccines. The com-
six studies, Simon Portegies Zwart of Leiden 2019 meeting did a new analysis. Based on parison trial in monkeys, in contrast, could
University calls for changes in computing a survey of computer and internet usage by shed light in a matter of weeks on how the
strategy. Astronomers should avoid tradi- delegates and organizers, they calculated candidates stack up on measures including
tional computers and instead use ones that emissions of 582 kilograms for the entire potential side effects, the strength of im-
rely on more efficient graphical processor meeting, less than one–three-thousandth of mune responses they trigger, and how well
units, Zwart says, although they are harder to the 2019 meeting total. “That really gave a they protect against infection and disease.
program. Astronomers should also abandon pause for thought,” says Mark McCaughrean,
popular programming languages such as Py- an author and a senior adviser at the Euro- “We should take a cold, hard look at all of
thon in favor of efficient compiled languages. pean Space Agency. the data and ask ourselves, ‘What appears
Languages such as Fortran and C++, Zwart to work best?’” says Nancy Haigwood, who
calculates, are more than 100 times more EAS is studying a hybrid format for future directs the Oregon National Primate Re-
carbon efficient than Python because they meetings, where those farther away would search Center and is a key advocate for the
require fewer operations. Another option, take part virtually. Rector says AAS has con- comparative monkey study.
says MPIA’s Knud Jahnke, is to set up super- tracts that commit it to several years of in-
computers in Iceland, with its carbon-free person meetings, but he expects the society The proposed monkey vaccine compari-
geothermal power and cold climate, which to move to virtual meetings after that. Societ- son faces hurdles: It would add to the pres-
reduces cooling needs, or in other countries ies, he says, “will learn from each other how sure on the dwindling U.S. supply of research
with plentiful renewable energy. to do it better.” monkeys, potentially delaying research on
other diseases, and it does not yet have fund-
Major observatories are also taking ac- This month, Lick workers cleared brush ing. Haigwood says she expected the U.S.
tion. ESO completed a solar power array and trees around the site to lessen the risk of government would gladly support the effort,
in 2016 for its La Silla Observatory in Chile future fires. Astronomers need to take action, which would cost an estimated $10 million,
and last year inked a deal for a photo- too, Burtscher says. It’s a moral decision—and compared with the $10 billion the Trump
voltaic plant to help cool its Extremely a practical one, he says. “We need to change administration’s Operation Warp Speed has
Large Telescope, now under construction in order to continue our professions.” j already devoted to a COVID-19 vaccine push.
But facing a lack of interest by current Warp
Astronomers lost sleep Speed officials, Haigwood and colleagues at PHOTO: UCO/LICK OBSERVATORY
watching flames approach the the six other national primate research cen-
Lick Observatory on its webcams. ters are now turning to the National Insti-
tutes of Health (NIH) for support.

Most developers of the vaccine candidates
in efficacy trials have already published
how well each works in monkeys against a
“challenge” with SARS-CoV-2—a deliberate

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A study comparing COVID-19 vaccines would use monkeys at the Oregon National Primate Research Center. groups, but because those firms have been
short on animals, more researchers have
exposure to the pandemic coronavirus that could deliver definitive results quickly. She turned to the national primate centers for
help. Haigwood says the U.S. consortium
causes COVID-19. But the details of how the says the monkey comparison could start as has many experiments now in the wings
that they’re willing to delay to conduct the
experiments were conducted and the ways soon as this month and would require only comparative COVID-19 vaccine work. “We
have set aside our precious monkeys for
the results were analyzed differ so pro- about 6 weeks to vaccinate animals, chal- this use, because we think it’s in the na-
tional interest.”
foundly that immunologist John Moore of lenge them, and assess their immune re-
The proposed comparative study would
Weill Cornell Medicine says he can’t make sponses and levels of protection. use a standardized stock of challenge virus
that NIH’s National Institute of Allergy and
sense of how the candidates compare. “It’s Yet now that human vaccine efficacy tri- Infectious Diseases (NIAID) recently made,
and it would follow consistent protocols to
comparing apples to oranges and bananas,” als are underway, says Moncef Slaoui, Warp challenge the monkeys and evaluate im-
mune responses to the vaccine candidates.
says Moore, who has co-authored a review, Speed’s chief scientific adviser, monkey stud- As a first step, Tulane has applied to NIH
for a $1.7 million grant to establish a coor-
on preprint.org, that compares the various ies won’t add much. “Frankly, I did this for dinating center to develop standard tech-
niques and data collection for the study. If
monkey studies. 30 years,” adds Slaoui, who headed vaccine NIH backs the full study, Haigwood and col-
leagues expect to test roughly 10 vaccines.
The human vaccine trials, for their part, development at GlaxoSmithKline, “and the Each vaccine challenge study would require
eight to 10 rhesus macaques; shared placebo
are likely to yield only preliminary sig- primate study is relevant to give you infor- groups would limit the animals needed.

nals of efficacy over the next few mation before the clinical trial. But A comparative monkey experiment was
part of Warp Speed’s early plans developed
months, not clear-cut evidence when you have a phase III trial in by Peter Marks of the Food and Drug Ad-
ministration (FDA). Marks, who left Warp
that one or more is safe and pro- Science’s tens of thousands of subjects, the Speed in part because it conflicted with
his job as head of the FDA division that
tects people. “We’re going to get COVID-19 relevance of that information is 10 oversees vaccines, had wanted to select
14 candidates for phase I and II human
data dribbling in from clinical reporting is times, 100 times more significant.” studies—early trials that focus on safety
trials,” says Haigwood, a veteran supported by the The backers of the monkey and immune responses, not efficacy—and,
AIDS vaccine researcher. Pulitzer Center in parallel, conduct the apples-to-apples
comparison see the situation dif- monkey studies. After Warp Speed assessed
The data from the many human and the ferently. “I understand that some both the monkey and human data, Marks
trials, some in multiple countries, Heising-Simons people say it’s too little, too late, hoped it would pick the best four or five for
human efficacy trials. “It may be that at the
Foundation. end of the day, they’ll get to a vaccine with
90%, 95% efficacy here, but that [proposed
will also be tough to compare. but it’s not,” insists Haigwood, comparative monkey study] was just a way
to try to get there,” Marks says. “I can’t say
Jay Rappaport, who heads the Tulane Na- who helped the seven national primate re- that I was right or wrong.”

tional Primate Research Center, notes the search centers form a consortium to con- NIAID head Anthony Fauci says “it would
be worthwhile” to conduct a rigorous com-
trial populations differ and are infected by duct the study. “This is not a competition parative study, noting that animal results
from vaccine studies for AIDS and other
different variants of SARS-CoV-2. In addi- with Warp Speed. The goal here is to have infectious diseases have also been difficult
to compare, complicating attempts to trans-
tion, the human trials—as with the monkey data that are additive.” late their results to humans. “It’s been one
of the banes of our existence.”
PHOTO: WILLIAM SUTTON/ONPRC/OHSU experiments—often use different assays to The comparison study would likely re-
If NIH won’t fund the work, Haigwood
measure immune responses. “There’s so quire a few hundred rhesus macaques, at says, she’ll turn to philanthropic institu-
tions. She also needs to persuade vaccine
much variation in the primate studies, but a time when the long-standing U.S. short- companies to supply their candidates. “I’ll
do whatever it takes,” Haigwood says, in-
there’s even more variation in the human age of monkeys for biomedical research cluding “twisting the arms” of companies.
“We can get a hell of a lot of information
studies,” Rappaport says. has been exacerbated by China’s decision before the end of December. Wouldn’t you
like to have that?” j
In contrast to the human trials that must in January to stop exporting all wild ani-

wait for enough participants to become nat- mals in the wake of COVID-19. The foreign

urally infected to gauge a vaccine’s worth, monkeys went to private labs that do con-

Haigwood says, monkey challenge studies tract research for companies and academic

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The LUX-Zeplin dark matter detector, which will hold
7 tons of liquid xenon, may have no larger successors.

Physicists have just started to build

the current plan’s centerpiece. The Long-

Baseline Neutrino Facility (LBNF) at Fermi

National Accelerator Laboratory (Fermilab)

in Illinois will shoot the particles through

1300 kilometers of rock to the Deep Under-

ground Neutrino Experiment (DUNE) in

South Dakota, a detector filled with 40,000

tons of frigid liquid argon. LBNF/DUNE,

which should come online in 2026, aims to

be the definitive study of neutrino oscilla-

PARTICLE PHYSICS tions and whether they differ between neu-

With to-do list checked off, U.S. trinos and antineutrinos, which could help
explain how the universe generated more
matter than antimatter.

physicists ask,‘What’s next?’ “The angst in the neutrino community is
a lot lower than it was last time,” says Kate
Scholberg, a neutrino physicist at Duke

Giant neutrino experiment is only sure thing for the field University. “The DUNE program will be go-
ing on at least into the 2030s.” However, re-

searchers are already thinking of upgrades

By Adrian Cho along. Others wanted the country to help to the $2.6 billion experiment, she notes.

push for the next big collider. In other areas, the future looks less certain.

A s U.S. particle physicists contemplate Those tensions came to a head during the The last time around, for example, scientists
their future, they find themselves vic- last Snowmass effort in 2013, and the sub- had a pretty clear path forward in their
tims of their own surprising success. sequent deliberations of the Particle Phys- search for particles of dark matter—the so-
Seven years ago, the often fractious ics Project Prioritization Panel (P5), which far-unidentified stuff that appears to pervade
community hammered out its current wrote the road map. U.S. researchers agreed the galaxies and bind them with its gravity.

research road map and rallied around to build the neutrino experiment, but make Researchers had built small underground de-

it. Thanks to that unity—and generous it bigger and better by inviting interna- tectors that searched for the signal of weakly

budgets—the Department of Energy (DOE), tional partners. They also decided to con- interacting massive particles (WIMPs), the

the field’s main U.S. sponsor, has already tinue to participate fully in the LHC, and to leading dark matter candidate, bumping into

started on almost every project on the list. pursue a variety of smaller projects at home atomic nuclei. The obvious plan was to ex-

So this week, as U.S. particle physicists start (see table, below). The next collider would pand the detectors to the ton scale.

to drum up new ideas for the next decade in a have to wait. Most important, DOE officials Now, two multi-ton WIMP detectors

yearlong Snowmass process—named for the warned, the squabbling and backstabbing are under construction. But so far WIMPs

Colorado ski resort where such planning ex- had to stop. In fact, physicists recall, the haven’t shown up, and scaling up that

ercises once took place—they have no single 2013 process had an informal motto: “Bick- technology further “is probably not going

big project to push for (or against). And in ering scientists get nothing.” to work very well anymore,” says Marcelle

some subfields, the next steps seem far less

obvious than they were 10 years ago. “We

have to be much more open minded about Missions accomplished CREDITS: (PHOTO) MATTHEW KAPUST/STANFORD UNDERGROUND RESEARCH FACILITY;
what particle physics and fundamental phys- (DATA) PARTICLE PHYSICS PROJECT PRIORITIZATION PANEL REPORT (2014)
ics are,” says Young-Kee Kim of the University Major projects prioritized by particle physicists in 2014 are approved, under construction, or up and running.
of Chicago, chair of the American Physical So-
ciety’s division of particles and fields, which PROJECT PURPOSE STATUS
is sponsoring the planning exercise.
Long-Baseline Neutrino Facility/Deep Study how neutrinos change type as they Civil construction
Underground Neutrino Experiment fly from Fermilab in Illinois to South Dakota. begun

Ten years ago, the U.S. particle phys- High-Luminosity Large Hadron U.S. contributions to upgrades at the LHC Design work

ics community was in disarray. The high- Collider (LHC) continuing

energy frontier had passed to CERN, the Camera for Vera C. Rubin Observatory Survey entire hemisphere of sky every 3 days. Under construction

European particle physics laboratory near Second- and third-generation Reach ton-scale detectors for Running or
Geneva, where in 2012 the world’s biggest dark matter detectors dark-matter particles. under construction
atom smasher, the Large Hadron Collider
(LHC), blasted out the long-sought Higgs Next-generation cosmic microwave Network of telescopes to study big Design work
boson, the last piece in particle physicists’ background experiment bang afterglow continuing

standard model. Some physicists wanted Dark Energy Spectroscopic Telescope to study distribution of galaxies Running
the United States to build a huge experi- Instrument and probe space-stretching dark energy

ment to fire elusive particles called neutri- Short-baseline neutrino Study properties of neutrinos in experiments Under

nos long distances through Earth to study experiments at Fermilab. construction

how they “oscillate”—morph from one of Proton Improvement Plan II New linear accelerator to increase power at Design work
their three types to another—as they zip Fermilab complex continuing

156 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

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NEWS | IN DEPTH

Soares-Santos, a physicist at the University INFECTIOUS DISEASES
of Michigan, Ann Arbor. “So we need to
think a little bit more out of the box.” Re- Newly found viruses suggest
searchers are now contemplating a hunt for rubella originated in animals
other types of dark matter particles, using
new detectors that exploit quantum me- Two relatives discovered in bats, mice, and zoo animals
chanical effects to achieve exquisite levels suggest “German measles” jumped the species barrier
of sensitivity.
By Ann Gibbons those in rubella. The protein that interacts
A perennial question for the field is what
the next great particle collider will be. The with the host’s immune cells was almost
obvious need is for one that fires electrons
into positrons to crank out copious Higgs T he virus that causes rubella, or Ger- identical in both viruses.
bosons and study their properties in detail, man measles, finally has company. As they were getting ready to publish,
says Meenakshi Narain, a physicist at Brown Scientists had never identified close
University. But possible designs vary. Physi- relatives of the virus, leaving it as the the researchers learned that a team led by
cists in Japan are discussing such a Higgs fac- only member of its genus, Rubivirus. Martin Beer at the Friedrich-Loeffler Insti-
tory in the form of a 30-kilometer-long linear tute had detected another rubella relative
electron-positron collider. Meanwhile, CERN
has begun a study of an 80- to 100-kilometer But with a report in this week’s issue in brain tissue from a donkey, a kangaroo,
circular collider. China has plans for a similar
circular collider. of Nature, rubella has gained a family. One and a capybara—a giant rodent native to

However, Vladimir Shiltsev, an accelerator of its two newfound relatives infects bats in South America—that all died from enceph-
physicist at Fermilab, says those aren’t the
only potential options. “The real picture is Uganda; the other killed animals from three alitis, an inflammation of the brain, at an
much murkier.” Snowmass organizers have
received at least 16 different proposals for different species in a German zoo and was unnamed zoo. They found the same virus
colliders, including one that would smash
together muons—heavier, unstable cousins found in wild mice living nearby as well. in wild yellow-necked field mice caught in
of electrons—and another that would use
photons. Snowmass participants should con- The findings strongly suggest that at or near the zoo. The mice appeared to be
sider all options, Shiltsev says.
some point in the past, a similar virus fine, suggesting they were a natural reser-
Joe Lykken, Fermilab’s deputy director
for research, suggests physicists could even jumped from animals to humans, giving voir from which the virus spilled over to
push for DOE to support a massive experi-
ment that has nothing to do with particles: rise to today’s rubella virus, “We would be the zoo animals.
a next-generation detector of gravitational the researchers say. Although remiss not Comparing their data, the
waves, spacetime ripples set off when mas- neither of the new viruses is
sive objects such as black holes collide. Their known to infect humans, the teams realized their viruses
discovery in 2015 by the Laser Interferometer were related, although ruhugu
Gravitational-Wave Observatory (LIGO)
opened a new window on the universe. to be concerned,fact that a related virus jumped was closer to rubella than the
second relative, the rustrela
LIGO consists of two L-shaped optical in- species raises concerns that
struments with arms 4 kilometers long in
Louisiana and Washington; it was built by the two viruses or other, as- given what’s virus, named after a lagoon in
the National Science Foundation. The next yet-unknown relatives could going on in the Baltic Sea. The teams de-
generation of ground-based detectors could cause human outbreaks. “We cided to publish jointly.
be 10 times as big, and might better fit DOE,
which specializes in scientific megaprojects, the world today.”would be remiss not to be con- The paper is “really im-
Lykken says. “It starts to sound like the kind portant because there’s very
of thing that the DOE would be interested in cerned, given what’s going on in
and maybe required for,” he says.
the world today,” says epidemio- Tony Goldberg, little understanding of where
During the coming year, Snowmass partic- logist Tony Goldberg of the Uni- University of rubella came from,” says mo-
ipants will air the more than 2000 ideas re- versity of Wisconsin, Madison, a lecular anthropologist Anne
searchers have already proffered in two-page senior author of the study. Wisconsin, Madison Stone of Arizona State Uni-
summaries. Then, a new P5 will formulate a
new plan. Whatever ideas scientists come up The rubella virus usually causes rashes and versity, Tempe. Measles and mumps also
with, to execute their new plan they’ll have
to maintain the harmony that in recent years fever, but in pregnant women it can lead to came from animals, Goldberg notes. “Now
has made their planning process an exem-
plar to other fields. “Being unified is the new miscarriages, stillbirth, and babies born with we know that every disease in the letters
norm for us,” quips Jim Siegrist, DOE’s asso-
ciate director for high energy physics. “So we congenital rubella syndrome, which includes of the MMR vaccine has a zoonotic origin,”
have to continue to keep a lid on divisiveness
and that’ll be a challenge.” j deafness and eye, heart, and brain problems. he says. Given the genetic distance between

An estimated 100,000 newborns are affected rubella and the ruhugu and rustrela viruses,

by the syndrome annually, mostly in Africa, the researchers don’t think either of them

the western Pacific, and the eastern Mediter- made the jump to humans—but they sus-

ranean; in many other countries the measles, pect they’ll find other Rubiviruses if they

mumps, and rubella (MMR) vaccine has look closely.

made it a rarity. Both viruses bear close watching, re-

Goldberg and his former graduate stu- searchers say. It’s “really interesting” that

dent Andrew Bennett discovered one of the rustrela was able to infect placental and

new viruses in apparently healthy cyclops marsupial mammals, and “was actively

leaf-nosed bats, netted at night in Kibale jumping between species,” says evolution-

National Park in Uganda. They named it ary virologist Edward Holmes of the Uni-

ruhugu virus, after the Ruteete region of versity of Sydney. That flexibility could spell

Uganda and the local word for bat. The ar- trouble, says vaccinologist Gregory Poland

chitecture of ruhugu’s genome is identical of the Mayo Clinic: “Who knows, if it could

to that of the rubella virus, and 56% of the move from mice to other mammals, could it

amino acids in its eight proteins matched move to humans?” j

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NEWS | IN DEPTH

PLANETARY SCIENCE

NASA mission set to sample carbon-rich asteroid

Bennu’s thick carbonate veins suggest past life as a water world

By Paul Voosen for us,” says Mike Moreau, the mission’s and a planetary scientist at the University CREDITS: (GRAPHIC) G. GRULLÓN/SCIENCE; (IMAGES, LEFT TO RIGHT) NASA; NASA/GODDARD/UNIVERSITY OF ARIZONA (2)
deputy project manager at NASA’s Goddard of Arizona. The veins also suggest watery
O SIRIS-REx is ready to get the goods. Space Flight Center. bodies like Bennu were a cauldron for the
On 20 October, after several years of organic chemistry that generated the amino
patient study of its enigmatic target, Despite the logistical challenge, the boul- acids and other unusual prebiotic com-
NASA’s $800 million spacecraft will ders contain a prize: veins of carbonate pounds found in carbon-rich meteorites
finally stretch out its robotic arm, minerals thicker than your hands, the team (Science, 14 August, p. 760).
swoop to the surface of the near- reports in one of six studies published today
Earth asteroid Bennu, and sweep up some in Science and Science Advances. The min- OSIRIS-REx won’t be sampling the car-
dust and pebbles. The encounter, 334 mil- erals, which precipitate out of hot water, bonate veins directly: The chamber at the
lion kilometers from Earth, will last about popped out of data gathered during a close end of its robotic arm is designed to suck up
10 seconds. If it is successful, OSIRIS-REx flyby of light-colored boulders near the tar- grit smaller than a penny. That’s all right,
could steal away with up to 1 kilogram of get site, called Nightingale. Researchers however, because the small pebbles strewn
carbon-rich material from the dawn of the believe the veins grew in channels of fluid across Nightingale also contain signs of
Solar System for return to Earth in 2023. circulating within Bennu’s parent body, a carbonates and other organic molecules,
larger planetesimal thought to have formed the team reports today. “This gives me a
Since OSIRIS-REx (short for Origins, beyond Jupiter’s orbit soon after the dawn hint that my dream is going to come true,”
Spectral Interpretation, Resource Identifi- of the Solar System 4.56 billion years ago, Lauretta says. “I want to bring back some-
cation, Security, Regolith Explorer) arrived before being smashed apart in the asteroid thing we’ve never seen before.”
in 2018, Bennu has yielded surprises, not belt within the last billion years. Heat from
all of them welcome. The 500-meter-wide the decay of radioactive elements in its in- The team picked Nightingale for its
asteroid was not smooth, as expected, but terior presumably drove the churning, and abundant pebbles and because the site ap-
studded with more than 200 large boulders the presence of so much carbonate “suggests pears young, probably because an impact
that could upset the sampling maneuver. large-scale fluid flow, possibly over the entire exposed it in recent geological time, leaving
And every so often, the asteroid ejected parent body,” says Hannah Kaplan, a plan- it largely unaltered by bombarding cosmic
coin-size pebbles, probably propelled etary scientist at Goddard who led the work. rays. But navigating the van-size spacecraft
by meteoroid impacts or solar heating. to a safe touchdown still won’t be easy; the
The boulder hazard, in particular, forced This ancient water world is consistent site is ringed with building-size rocks, in-
the team to target an area just 16 meters with the idea that objects like Bennu deliv- cluding one nicknamed Mount Doom, along
across for sampling, 10 times smaller than ered much of Earth’s water when they struck with smaller boulders throughout. Observa-
planned. “Bennu has not made things easy the planet billions of years ago, says Dante tions suggest many of these boulders are
Lauretta, the mission’s principal investigator porous, almost fluffy, and would crumble if
touched. But the team doesn’t want to take
To an asteroid and back that chance: Using its cameras to navigate,
the spacecraft will automatically abort its
On 20 October, OSIRIS-REx, a NASA asteroid sample return approach at an altitude of 5 meters if the
mission, will attempt to gather up to 1 kilogram of dust and pebbles site appears hazardous.
for eventual return to Earth. Its carbon-rich target, Bennu, could
hold organic molecules from the Solar System’s earliest days. The entire sampling attempt, lasting
4.5 hours, needs to be autonomous; Bennu
Local target Earth The spacecraft will extend is currently five times farther from Earth
Bennu’s orbit brings it a sampling arm as it than Mars, and radio signals take 18 min-
nearly as close to Earth Bennu approaches its target area. utes to reach it. After thruster maneuvers
as the Moon. OSIRIS-REx Approach bring it to the touch point with Bennu,
reached the asteroid Sun blasts of nitrogen should push dust and
in 2018. pebbles into the doughnut-shaped collec-
tor at the end of the robotic arm. It will
Scientific treasure *not to scale A "touch and go" be several days before NASA can judge
OSIRIS-REx’s return maneuver how much was gathered, based on images
capsule will parachute to Bennu of the target site and sampling head, and
landing in Utah in 2023. Nitrogen changes in how the spacecraft spins. By
the end of the month, managers will de-
Collected sample cide whether to make a second attempt at
a backup site in January 2021. Either way,
On contact, the arm The gas will sweep the spacecraft will leave Bennu next year
and head back to Earth. It will arrive in
International will blast Bennu’s up at least 60 grams September 2023 and eject the sample cap-
Space Station sule, which will parachute to a landing in
surface with nitrogen. of material. the Utah desert. j

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NEWS

FEATURES

Passengers wait for a Stockholm ferry in July. Swedish health officials insist face masks offer a false sense of security and can lead people to forget about social distancing.

SWEDEN’S GAMBLE
The country’s pandemic policies came at a
high price—and created painful rifts in its scientific community

PHOTO: JONATHAN NACKSTRAND/AFP VIA GETTY IMAGES O n 5 April, Anders Tegnell, chief By Gretchen Vogel when visiting busy, closed spaces.” Tegnell
epidemiologist for the Swedish still disagrees. “We have looked very care-
public health authority, sent an vice “would also imply that the spread is air- fully. The evidence is weak,” he told Science.
email to the European Centre borne, which would seriously harm further “Countries that have masks are not doing
for Disease Prevention and Con- communication and trust among the popu- the best right now. It is very dangerous to
trol (ECDC) expressing concern lation and health care workers.” try to believe that masks are a silver bullet.”
about proposed new advice that
face masks worn in public could On 8 April, ECDC published its recom- Sweden’s approach to the coronavirus
slow the spread of the pandemic mendations anyway, in line with an emerg- pandemic is out of step with much of the
coronavirus. “We would like to warn against ing scientific consensus. Although questions world. The government never ordered a
the publication of this advice,” Tegnell remained, “use of face masks in the commu- “shutdown” and kept day care centers and
wrote. How much people without symptoms nity could be considered,” it said, “especially primary schools open. While cities world-
contribute to spread was a “question that wide turned into ghost towns, Swedes could
remains unanswered,” he wrote, and the ad- Science’s COVID-19 reporting is supported by the be seen chatting in cafés and working out at
Pulitzer Center and the Heising-Simons Foundation. the gym. The contrast evoked both admira-

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NEWS | FEATURES

tion and alarm in other countries, with jour- in the opinion pages of newspapers, within has been so, so surreal,” says Nele Brusselaers,

nalists and experts debating whether the university departments, and among hospital a member of the Vetenskapsforum and a

strategy was brilliant—or whether Tegnell, staff. A group of scientists known as “the clinical epidemiologist at the prestigious

its main architect, had lost the plot. 22” has called for tougher measures since Karolinska Institute (KI). It is strange, she

The country did not ignore the threat April, when it published a blistering critique says, to face backlash “even though we are

entirely. Although stores and restaurants of the country’s public health authority, the saying just what researchers internationally

remained open, many Swedes stayed home, Folkhälsomyndigheten (FoHM). The group, are saying. It’s like it’s a different universe.”

at rates similar to their European neighbors, which has grown to include 50 scientists

surveys and mobile phone data suggest. and another 150 supporting members, now LENA EINHORN PAID CLOSE attention in Janu-

And the government did take some strict calls itself the Vetenskapsforum COVID-19 ary to the news of a new virus spreading in

measures in late March, including bans on (Science Forum COVID-19). Wuhan, China. Einhorn, who has an M.D./

gatherings of more than 50 people and on It says the price for Sweden’s laissez-faire Ph.D. in virology and tumor biology, is bet-

nursing home visits. approach has been too high. The country’s ter known in Sweden as a filmmaker and

Yet Sweden adopted strikingly different cumulative death rate since the beginning book author. “But I can still read a scientific

policies from those of other European coun- of the pandemic rivals that of the United paper,” she says. And what she read in The

tries, out of a desire to avoid disrupting daily States, with its shambolic response. And the Lancet on 31 January was alarming: A model

life—and perhaps the hope that,

by paying an immediate price

in illness, the country could

achieve “herd immunity” and

put the pandemic behind it.

Swedish authorities actively

discouraged people from wear-

ing face masks, which they said

would spread panic, are often

worn the wrong way, and can

provide a false sense of safety.

Some doctors who insisted on

wearing a mask at work have

been reprimanded or even fired.

Until last month, Sweden’s of-

ficial policy stated people with- PHOTOS: (CLOCKWISE FROM LEFT) ASTRID ERIKSSON TROPP/CC 3.0; ANDERS WIKLUND/TT NEWS AGENCY/AFP VIA GETTY IMAGES; IBL/SHUTTERSTOCK

out obvious symptoms are very

unlikely to spread the virus. So

instead of being quarantined

or asked to stay home, fam-

ily members, colleagues, and

classmates of confirmed cases

had to attend school and show

up for work, unless they had

symptoms themselves. Test-

ing in Sweden still lags behind

many other countries, and in

many districts infected people

are expected to notify their own

contacts—in contrast to, say,

Germany and Norway, where

small armies of contact tracers Lena Einhorn (left) is a member of the Vetenskapsforum COVID-19, a group that has harshly criticized policies championed by

help track down people who Sweden’s chief epidemiologist, Anders Tegnell (upper right), and his predecessor, Johan Giesecke (lower right).

may have been exposed.

The Swedish approach has its fans. virus took a shocking toll on the most vul- predicted large outbreaks of the new virus in

Protesters against coronavirus-related re- nerable. It had free rein in nursing homes, cities around the world. As far as she could

strictions in Berlin in late August waved where nearly 1000 people died in a matter see, nothing was being done in Sweden to

Swedish flags. In the United States, a of weeks. Stockholm’s nursing homes ended get ready for the threat.

prominent member of President Donald up losing 7% of their 14,000 residents to the Concerned, she wrote an email to Tegnell.

Trump’s coronavirus task force, neuro- virus. The vast majority were not taken to “I asked, ‘Have you seen this paper? Isn’t it

radiologist Scott Atlas, has cited Sweden as hospitals. Although infections waned over time we prepare for this?’” Tegnell answered

a model to follow. The policies also have the summer, scientists worry a new wave immediately, Einhorn says: “He basically

widespread public support in Sweden, will hit in the fall. Cases are rising rapidly said, ‘Well, we shall see. Everyone is trying

where consensus is prized and criticism of in the greater Stockholm area, where almost to apply complex models to very limited

the government is rare. one-quarter of the Swedish population lives. data.’” She wrote back emphasizing how

But within Sweden’s scientific and medi- The group’s criticism has not been easily the virus seemed to spread, including

cal community, a debate about the strategy welcomed—indeed, some of the critics say from people without obvious symptoms, and

has simmered and frequently boiled over— they have been pilloried or reprimanded. “It asked about restricting travel from China.

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Tegnell noted that the World Health Organi- home if possible, FoHM said, but tests re- their numbers wrong. Tegnell said the au-

zation (WHO) opposed such measures, she mained very limited, and close contacts of thors “were not leaders in their field” and

says, then stopped responding. So Einhorn suspected cases were not asked to stay home claimed they “cherrypicked” days with the

approached Björn Olsen, a professor of in- unless they had symptoms. highest death tolls. (The scientists replied

fectious diseases at Uppsala University who Soon, infections surged. By late March, they had used ECDC statistics and noted

was raising the alarm in interviews. “What more than 30 COVID-19 patients were being there were even more deaths the next

can we do?” she says she asked Olsen. admitted to ICUs every day. By early April, week.) The response to the op-ed was “in-

In late February, during the school holi- Sweden was recording about 90 deaths from sane,” says co-author Jan Lötvall, an aller-

days, thousands of families went skiing in the virus daily—a significant undercount, gist at the University of Gothenburg. “A

the Alps—just as reports surfaced about an critics say, because many died without get- colleague emailed me to say [the article]

outbreak in northern Italy. Many had asked ting tested. Hospitals did not become as was shameful, and that we should be loyal

whether they should stay home, but health overwhelmed as those in northern Italy or and follow the tradition of respecting pub-

authorities “kept saying, ‘No, don’t cancel New York City, but that was in part because lic health workers.”

your trip!’” Einhorn says. “It was the middle many severely ill patients weren’t hospi- The frontal attack violated one of Swe-

of that week when the cases in the Italian talized. A 17 March directive to Stockholm den’s strongest cultural norms, the taboo on

Alps went boom.” As vacationers returned, area hospitals stated patients older than 80 open disagreement, says Andrew Ewing, an

many asked whether they should quaran- or with a body mass index above 40 should analytical chemist at the University of Go-

tine, but FoHM maintained there was no not be admitted to intensive care, because thenburg who moved to Sweden from the

reason to worry. they were less likely to recover. Most nurs- United States 13 years ago. If a disagreement

When 30,000 music fans gathered in ing homes were not equipped to administer does arise, “you can never make it personal,”

a Stockholm arena on 7 March for the na- oxygen, so many residents instead received says Ewing, who was not part of the original

tional final of the Eurovision Song Contest, morphine to alleviate their suffering. News- 22 but has since joined the Vetenskapsforum.

“I’m going bonkers,” Einhorn says. “I “When the debate started, harsh

can’t sit still.” She reached out to a words were exchanged,” says Göran

journalist friend and started to write Unwelcome distinction Hansson, a cardiac specialist at KI and
op-eds. Olsen linked her to “a group of secretary general of the Royal Swedish
desperate scientists,” she says. “Sud- One measure of COVID-19’s impact, excess mortality, was far Academy of Sciences. But the debate
denly I’m in the middle of an email higher in Sweden than in neighboring countries and Germany, is important, he adds. “Maybe Sweden
thread of infectious disease special- but not as high as in England and Wales. has too much of a consensus culture.
ists, virologists, epidemiologists,” all … It’s healthy for science to have dis-
England & Wales Sweden Norway Germany Denmark

extremely worried. 200 cussions. One thing we don’t need in
CREDITS: (GRAPHIC) X. LIU/SCIENCE; (DATA) THE HUMAN MORTALITY DATABASE, U.K. OFFICE FOR NATIONAL STATISTICS
On 12 March, as new cases outpaced 150 this situation is silencing of views, es-
Excess deaths per milliontest capacity, FoHM announced doc- pecially from those with expertise.”

tors should only test those with severe 100 Healthy or not, Brusselaers says she
symptoms, recalls KI immunologist also faced backlash from colleagues

Cecilia Söderberg Nauclér. “I turned 50 and was publicly reprimanded by her
to my husband and said, ‘They are let- department chair for being a “trouble-

ting it loose. We are going to crash the 0 maker” and “a danger to society.” “A
health system. We are going to need colleague told me, ‘We have to stick

500 ICU [intensive care unit] beds –50 with [FoHM] and defend it,’” she says.

and we have 90 in Stockholm.’” On 1 March 1 April 1 May 1 June 1 July The situation prompted her to return

the same day, Norway closed schools, to her native Belgium, where she now

many businesses, and its borders, mirroring paper reports told stories of people who died has a position at the University of Antwerp,

measures across Europe. after being turned away from emergency although she is also keeping her group at KI.

On 15 March, Olsen, Nauclér, and five oth- rooms because they were deemed too young “I just didn’t expect this reaction in Sweden,”

ers warned in an opinion piece in the Sven- to suffer serious COVID-19 complications. she says. “I never felt like such a foreigner as

ska Dagbladet newspaper that Sweden was On 25 March, as confirmed cases passed I did over the past few months.”

just a few weeks behind Italy, where hospi- 300 per day, about 2000 scientists signed Those who challenged the recommen-

tals were already overflowing. Nauclér says an open letter calling for stricter control dations against face masks faced a simi-

she reached Tegnell by phone the next day measures. It provoked little reaction. But lar backlash. Agnieszka Howoruszko, an

and told him, “I don’t want to argue with a scathing op-ed, published by the 22 re- ophthalmologist at a regional hospital

you, but you shouldn’t be doing what you’re searchers in the newspaper Dagens Nyheter in Landskrona, began to wear a mask in

doing unless you have data that I don’t know on 14 April, did get noticed. The piece carried March when she examined patients. “My

about.” She says they had a good conversa- the headline “The public health agency has manager reprimanded me twice,” she says.

tion and Tegnell agreed to a meeting, but it failed. Politicians must intervene.” It noted Howoruszko held her ground. “I said, ‘I’m

never happened. that from 7 to 9 April, more people per mil- sorry, if I can’t wear it, I cannot work. Many

The next week, Tegnell announced Swe- lion inhabitants had died in Sweden from of my patients are elderly and in high-risk

den would try to “flatten the curve” so the COVID-19 than in Italy—and 10 times more groups.” The manager relented and allowed

health system would not get overwhelmed than in Finland. FoHM officials “have so far the clinic’s doctors (but not other staff ) to

with cases. The government limited gather- not shown any talent for either predicting or wear masks. “We are the only eye clinic in

ings to a maximum of 500 people, but day limiting” the epidemic, they wrote. our province” to take that step, she says.

care and schools through ninth grade stayed The response was swift. A cascade of Dorota Szlosowska, a pulmonologist who

open. (Upper secondary schools and univer- columnists and opinion writers criticized had been working at Sundsvall regional hos-

sities went online.) People should work from the piece for its tone and said the 22 got pital, shared an email with Science stating

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NEWS | FEATURES

that one of the reasons her contract wasn’t nosed with COVID-19, and at least 5895 population would have to be immune to ar- PHOTO: DAVID LIDSTROM/GETTY IMAGES
renewed was that “she walked around with have died. The country has seen roughly rest the spread of the virus. Many scientists
a mask,” which the email said made her look 590 deaths per million—on par with 591 per say reaching that percentage without the
unfriendly and made it hard for patients million in the United States and 600 in Italy, help of a vaccine would cause far too many
to understand her. Björn Lindström, an but many times the 50 per million in Nor- deaths and long-term side effects.
ophthalmologist at Falu lasarett, a hospital way, 108 in Denmark, and 113 in Germany.
in central Sweden, says he is the only one Tegnell has consistently denied that herd
in his clinic who wears a mask. In a letter Another way to measure the pandemic’s immunity is his goal. But emails released in
in Dagens Nyheter, Lindström has argued impact is to look at “excess deaths,” the dif- late July after journalists requested them
that the failure of health care workers to ference between the number of people who under open records laws show he discussed
adopt masks violates Sweden’s patient safety died this year and average deaths in earlier the idea. In an exchange on 14 and 15 March
act, meant to prevent patients from being years. Those curves show Sweden did not with the head of Finland’s public health
harmed while receiving care. suffer as many excess deaths as England agency, Tegnell speculated that “one point
and Wales—whose tolls were among Eu- would be to keep schools open to reach
HARM SEEMS to have occurred. The Falu la- rope’s highest—but many more than Ger- herd immunity faster.” When the Finn-
sarett announced last week that it had been many and its Nordic neighbors (see graphic, ish colleague said models suggested clos-
fighting a COVID-19 outbreak in its cardiac p. 161). Immigrant communities were hit ing schools would decrease infection rates
ward for 3 weeks, with 10 patients and 12 staff very hard. Between March and September, among the elderly by 10%, Tegnell replied:
infected so far. As of 27 September, staff will 111 people from Somalia and 247 from Syria “Ten percent might be worth it?” (Tegnell
“use protective visors when working closely died, compared with 5-year averages of says he was only speculating, and the pros-
with patients,” the hospital said. The Swed- 34 and 93, respectively. pect of reaching herd immunity was irrel-
ish Health and Social Care Inspectorate told evant to the decision to keep schools open.)
Science it is investigating 17 hospital and TEGNELL HAS SAID repeatedly that the
clinic-based outbreaks. In September, Ry- Swedish strategy takes a holistic view of Tegnell’s thinking appears to have been
hov community hospital in Jönköping an- public health, aiming to balance the risk shaped by his predecessor, Johan Giesecke,
nounced 20 patients and 40 staff members of the virus with the damage from counter- an epidemiologist and professor emeri-
had been infected in an outbreak in the hos- measures like closed schools. The goal was tus at KI with whom he exchanged many
pital’s orthopedic ward in May. Five patients to protect the elderly and other high-risk emails. Giesecke has been a vocal defender
died and one is still hospitalized. (The hospi- groups while slowing viral spread enough of FoHM’s strategy, which he praised in a
tal said it had followed FoHM’s policies.) At to avoid hospitals being overwhelmed. 5 May article in The Lancet. He said the vi-
least three patients have reportedly died of Protecting the economy was not the aim,
COVID-19 after being infected at the univer- he says. (Initial data suggest Sweden’s
sity hospital in Lund. economy contracted about as much as its
immediate neighbors’ as exports and con-
FoHM’s decision to keep schools open sumer spending dropped.)
despite surging cases may also have added
to the spread. A report from the agency Sweden’s light approach is more sus-
itself, released in July, compared Sweden tainable than the harsher methods used
with Finland, which closed its schools be- in other countries, Tegnell also argues. He
tween March and May, and concluded that regrets the death toll in nursing homes, he
“closing of schools had no measurable ef- told Science, and says Sweden should have
fect on the number of cases of COVID-19 made it easier financially for caregivers to
in children.” But few Swedish children stay home. “It was a very bad situation for
were tested in that period, even if they had a month,” he says, “but after that it changed
COVID-19 symptoms. When new FoHM completely.” Once strong restrictions were
guidelines allowed symptomatic children in place, transmission in nursing homes “be-
to be tested in June, cases in children shot came lower than in the community.” Tegnell
up—from fewer than 20 per week in late has also said he suspects the number of in-
May to more than 100 in the second week fections and deaths in other countries will
of June. (FoHM reversed course in July and eventually match Sweden’s. Einhorn finds
returned to recommending that children this absurd: “If Norway ever catches up to
under 16 not be tested.) Sweden in the proportion of people killed by
COVID-19,” she says, “I’ll eat my hat.”
Indirect data suggest children in Sweden
were infected far more often than their Many of Tegnell’s critics say FoHM had
Finnish counterparts. The FoHM report says an unspoken agenda: to reach herd immu-
14 Swedish kids were admitted to intensive nity. Sweden wouldn’t be the only country to
care with COVID-19, versus one in Finland, consider that strategy: British Prime Minis-
whichhasroughlyhalfasmanyschoolchildren. ter Boris Johnson toyed with the idea before
In Sweden, at least 70 children have been rejecting it (and contracting COVID-19 him-
diagnosed with multisystem inflammatory self ). Dutch Prime Minister Mark Rutte ex-
syndrome, a rare complication of COVID-19, plicitly said achieving herd immunity would
versus fewer than five in Finland. help protect the economy before also aban-
doning the idea.
In the population as a whole, the impact
of Sweden’s approach is unmistakable. More Herd immunity is still not well under-
than 94,000 people have so far been diag- stood, but scientists estimate that in the case
of COVID-19, between 40% and 70% of a

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A senior couple dines separately from the rest of their
family on 18 April in Östersund, Sweden. The Swedish
government never ordered a lockdown, but many
citizens reduced their contacts anyway, data suggest.

ond week of September to 967 last week.
Whether immunity is making a big differ-
ence remains to be seen.

rus was “an invisible pandemic” in which showed the number was actually about 6% THE SWEDISH EXPERIMENT is coming to an
98% to 99% of infected people don’t real- in late May, Tegnell said immunity was hard end, as its policies fall in line with those of
ize they have been infected. “Our most im- to measure. FoHM continued to say Swedes its neighbors. FoHM officials are “quietly
portant task is not to stop spread, which is had built up immunity, but in September changing their approach,” Einhorn says. The
all but futile, but to concentrate on giving it backtracked, estimating that “just under country has boosted test rates; at roughly
the unfortunate victims optimal care,” he 12%” of Stockholm residents, and 6% to 8% two tests per 1000 inhabitants per day,
wrote. (Giesecke stated he did not have any of the Swedish population as a whole, had Sweden’s testing rate is almost on par with
conflicts of interest, but his correspondence antibodies to the virus by mid-June. Norway’s—although it is only one-quarter
with Tegnell revealed he had been a paid of Denmark’s. The recommendation against
consultant for FoHM since March. Giesecke If herd immunity is beginning to kick in, testing children between ages 6 and 16 was
told Science he sees no conflict.) it should become visible in Sweden’s case lifted for a second time in September. (FoHM
numbers. Cases fell from a record 1698 says this is so children with mild symptoms
Giesecke, a member of WHO’s Strategic on 24 June to about 200 per day in early can return to school more quickly if their
and Technical Advisory Group for Infectious September, and the percentage of positive test is negative.) Children under 6 are still
Hazards, is still advising a similar approach tests reached a record low of 1.2%. Some not tested unless severely ill.
to governments elsewhere. On 23 Septem- speculate that Sweden’s summer traditions
ber, he told an Irish parliamentary commit- may have helped: Hundreds of thousands The drop in cases allows Sweden to start
tee that Ireland should aim for “controlled leave cities and towns for remote cabins in to use its contact tracing system, in place
spread” in people under age 60 and “tolera- what amounts to 3 months of national so- for other diseases, for COVID-19, Tegnell
ble spread” among those over age 60, though cial distancing. says: “Before, we just didn’t have the capac-
in a later interview he backed off, saying Ire- ity.” And on 1 October, FoHM announced
land had to decide policies for itself. At the time, numbers elsewhere in Eu- family members of confirmed cases should
rope were beginning to soar again, espe- stay home for 7 days, even if they don’t have
Giesecke and Tegnell believed herd im- cially among young adults, whereas those any symptoms—although children through
munity would arrive quickly. In the Lan- in Sweden remained stable. But over the ninth grade should still go to school.
cet article, Giesecke claimed about 21% of past few weeks, infections in Sweden have
residents of Stockholm county had already started to rise as well. On 25 September, FoHM should go much further, Hansson
been infected by the end of April; Tegnell FoHM reported 633 new cases nationwide and a colleague said in an August opinion
predicted 40% of them would have antibod- in 1 day. Stockholm’s rates have nearly piece, for instance by limiting public trans-
ies by the end of May. When initial studies tripled in 2 weeks, from 334 in the sec- port to 50% capacity, recommending masks,
and asking travelers from hard-hit regions
abroad and all contacts of known cases to
quarantine. On 25 September, Hansson an-
nounced the Royal Swedish Academy had
assembled an expert group to compare the
Swedish response with that of other coun-
tries and recommend how “researchers can
best contribute to future crisis situations.”

FoHM “should have listened more care-
fully to the scientific community both in-
side and outside the country,” Hansson says.
Still, he predicts the rifts will eventually
heal. “I am sure we will continue to argue,
but I don’t see permanent damage,” he says.
“We’ll move on. We’ll go back to complain-
ing about grants.”

But Ewing worries the fight has left per-
manent scars. He says at least three more
members of the Vetenskapsforum are con-
sidering leaving Sweden, as Brusselaers did.
And even if it turns out that the country has
built up enough immunity to evade a new
wave of disease, he says, the price has been
too high. “I worry that countries around
the world are going to say, ‘We can try what
Sweden did.’ But we have killed too many
people already.” j

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INSIGHTS

PERSPECTIVES

COMMUNITY ECOLOGY

Novel communities are a risky business

High turnover leads to novel combinations of species and involves high extinction

By Maria Dornelas1 and Joshua S. Madin2 encapsulated in turnover hold essential in- tions, there is some degree of turnover; envi- PHOTO: M. I. WALKER/SCIENCE SOURCE
formation about biodiversity change. High ronmental variation and chance events lead
A s in business, most action in bio- turnover is emerging as the signature of to some fluctuation in which species exist in
diversity happens in turnover. Net biodiversity patterns in the Anthropocene any particular community. One view is that
changes in balance give us some in- (1–3), raising questions as to the causes and this variation occurs within bounds because
dication of performance. However, consequences of high turnover in biodiver- ecological communities exist in dynamic
knowing the volumes of income and sity. On page 220 of this issue, Pandolfi et equilibrium in configurations called stable
payments that make up that balance al. (4) look into the deeper past to identify states. Extreme disturbances and persistent
conveys much more information about when turnover is so increased that it results forces can lead to abrupt changes in com-
how a business is operating. The same is in completely new combinations of species,
true of ecological communities: Knowing known as novel communities. 1Centre for Biological Diversity, School of Biology,
net changes in the number of species is University of St Andrews, St Andrews, UK. 2Hawai’i Institute
useful, but the gains and losses of species The stability of ecological communities is of Marine Biology, University of Hawai’i at Manoa, Honolulu,
a controversial topic. Under normal condi- HI, USA. Email: [email protected]

164 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

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munities called phase shifts (5), which are Examination of global marine plankton communities ples of extraordinary communities that no
characterized by very high turnover in com- over the past 65 million years (such as fossil diatom longer exist. Benthic marine faunas of the
position. Modern examples of this phenome- communities, shown) suggests that change in Cambrian bear little resemblance to those
non are shifts between coral- and algal-dom- community composition leads to further change, of the modern because of the extinction or
inated systems in tropical reefs or between including extinction. major decline of groups such as the trilo-
clear and turbid lakes (5). A contrasting view bites and brachiopods and the radiation of
is that community composition changes con- The rates of change in species losses and groups such as snails, clams, and corals (11).
tinuously, determined by a complex array of gains that underpin turnover have varied Pandolfi et al. add to growing evidence that
continuously changing conditions interact- greatly in the past (10). The biggest turn- turnover occurs even during relatively sta-
ing with demographic variation of each spe- over events occurred during mass extinc- ble periods of the past. This constant change
cies (6). This view is supported by growing tion events (11). However, in their study of in composition has important implications
empirical evidence that discrete community the past composition of marine plankton for conservation goals because it challenges
stable states, and shifts between them, are communities, Pandolfi et al. identify sev- the idea of baseline communities with any
rare or nonexistent (7). Even gut microbi- eral transitions in the past 65 million years particular composition. Communities have
omes, originally thought to be relatively sta- when increased turnover led to the appear- always changed in their composition and
ble, show extraordinary turnover (8), with ance of novel communities. These transi- should continue to do so. A nostalgic long-
communities measured weeks apart bearing tions are rare in the time period examined ing for a lost Garden of Eden, which per-
very little resemblance to one another (9). but highly influential in that they disrupt meated the roots of the conservation move-
Looking at how communities have changed the communities of species that are found ment, is not supported by what we know of
in the past can help us understand the me- together. For example, the biotic interac- the past and expect in the future. 
chanics of stability. tions that are necessary for ecosystems to
function are disrupted during periods of Understanding past transitions to novel
increased turnover (12). Critically, Pandolfi communities has important implications
et al. find evidence that novelty generates for current trends in biodiversity. Cases of
more novelty, with transitions among novel complete turnover in marine assemblages
states being 2 to 10 times more likely than (3), combined with evidence of accelerating
one would expect by chance. The transience extinction and colonization rates (14), add
of novel communities is perhaps indicative to the evidence that many communities are
of restructuring biotic interactions. Using currently undergoing similar transitions.
the quantitative approach proposed by Lessons from the past warn us that more
Pandolfi et al., it will be possible to exam- change is likely to unfold. The past also
ine whether periods of transition to novel tells us that although biodiversity is always
communities coincide with periods of dis- changing, not all change is the same. The
ruption in ecosystem functions.  dynamic nature of community composition
provides an argument for conservation goals
Transitions to novel communities are to focus on rates of change (15) rather than
underpinned by enhanced rates of local aiming for particular states and for biodiver-
extinctions and colonizations (see the fig- sity science to scrutinize the mediating pro-
ure). Four main types of process have been cesses (13) responsible for changing rates. j
proposed to mediate community dynamics:
drift, selection, dispersal, and speciation REFERENCES AND NOTES
(13). Drift entails random changes in spe-
cies abundances; selection refers to differ- 1. M. Dornelas et al., Science 344, 296 (2014).
ences among organisms that determine 2. H. Hillebrand et al., J.Appl. Ecol. 55, 169 (2018).
their ability to leave descendants; dispersal 3. S.A. Blowes et al., Science 366, 339 (2019).
relates to movement of organisms across 4. J. M. Pandolfi et al., Science 370, 220 (2020).
different communities; and speciation is 5. M. Scheffer, S. Carpenter,J.A. Foley, C. Folke, B.Walker,
the process of generating new species. Drift
and selection control extinction rates, and Nature 413, 591 (2001).
colonization can arise either from disper- 6. D. E. Schindler,J. B.Armstrong,T. E. Reed, Front. Ecol.
sal of existing species or speciation. All
four processes are likely to accelerate in Environ. 13, 257 (2015).
transitions to novel communities. For ex- 7. H. Hillebrand et al., Nat. Ecol. Evol. 10.1038/s41559-020-
ample, 10 million to 12 million years ago,
climatic change unleashed selection forces, 1256-9 (2020).
in combination with enhanced dispersal fa- 8. S. Priya, R. Blekhman, Genome Biol. 20, 150 (2019).
cilitated by new land bridges, which led to 9. J. R.Johnson et al., J. Clin. Microbiol. 46, 4078 (2008).
novel communities in North America (12). 10. J.Alroy et al., Science 321, 97 (2008).
Pandolfi et al. find that transitions to novel 11. J. Sepkoski Jr., R. K. Bambach, D. M. Raup,J.W.
communities involve the highest rates of lo-
cal extinctions and originations (relative to Valentine, Nature 293, 435 (1981).
emigrations and immigrations).  12. J. L. Blois, P. L.Zarnetske, M. C. Fitzpatrick, S. Finnegan,

Evidence is clear that the composition of Science 341, 499 (2013).
ecological communities is not static. The 13. M.Vellend, Q. Rev. Biol. 85, 183 (2010).
history of life on this planet is full of exam- 14. M. Dornelas et al., Ecol. Lett. 22, 847 (2019).
15. D. Leclère et al., Nature 10.1038/s41586-020-2705-y

(2020).

ACKNOWLEDGMENTS

M.D. and J.S.M. are supported by a National Science
Foundation–Natural Environment Research Council
Biological Oceanography grant (1948946). M.D. is supported
by Leverhulme Trust Research Centre–the Leverhulme Centre
for Anthropocene Biodiversity and a Leverhulme Research
Grant (RPG-2019-402).

10.1126/science.abe4727

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INSIGHTS | PERSPECTIVES

INFECTIOUS DISEASE

Making a bed for viral infections

An inflamed mucosal niche is permissive for symptomatic respiratory syncytial virus infection

By Ananda S. Mirchandani and The timing of neutrophil presence in tis- ulation levels of the neutrophil-associated

Sarah R. Walmsley sues, as well as their activation status, appears proteases lipocalin-2 (LCN2) and myeloper-

to be key. It has been demonstrated that de- oxidase (MPO) in the nasal mucosa of the

I n the past 100 years, humans have har- pletion of nonactivated neutrophils before in- individuals who developed RSV infection.
nessed the power of antibiotics to save fection and thereafter, or enhancement after Moreover, CXCL1 enhanced MPO production
countless lives from bacterial infec- infection, does not worsen RSV outcomes in in mice, beyond the levels seen in RSV infec-
tion, however, our capacity to treat vi- mice (9). Habibi et al. inoculated 58 healthy tion alone, suggesting that CXCL1 per se was
ral illnesses lags far behind. Prevention adults with RSV and assessed the preinfec- altering the lung niche.

through vaccination has been the most tion transcriptional landscape of their nasal While the timing of the inflammatory

effective method to tackle viral infections, mucosa, identifying a specific inflammatory milieu appears to be important in allowing

yet vaccines have not always been achievable, milieu in those who developed symptomatic the establishment of a symptomatic RSV in-

as in the case of respiratory syncytial fection, the dynamic changes in the

virus (RSV) (1). In most people, RSV immune responses recorded in the

infection causes a mild “cold”-like Mucosal niches cohort by Habibi et al. are also in-
illness, and by age 2, most children sightful. Those who developed RSV
will have been infected by RSV (2). The presence of inflammatory mediators such as the neutrophil infection had lower intranasal levels
Although most develop only mild chemokine interleukin-17 (IL-17) and the neutrophil-associated of the archetypal “cytokine storm” cy-
symptoms, some children will develop proteases lipocalin-2 (LCN2) and myeloperoxidase (MPO) in the tokines, interleukin-1b (IL-1b), IL-10,
nasal mucosa of adults is associated with symptomatic respiratory

severe lung inflammation (bronchiol- syncytial virus (RSV) infection. Dissecting the mechanisms and and IL-6, in the presymptomatic

itis) that can be fatal. Therefore, de- immune responses that also allow asymptomatic infection and viral phase of the infection. This finding

termining the risk of severe illness shedding is an important future aim. emphasizes that immune responses

would transform the management of are dynamic and that snapshots in

RSV. On page 188 of this issue, Habibi disease processes may be misleading,

et al. (3) identified an inflammatory especially when cross-talk between in-

signature in adults susceptible to nate and adaptive immune responses

symptomatic RSV infection, which RSV is being ascertained. Furthermore, al-

they ascribe to activated neutrophils. though an increased preinfection IL-17

Their findings suggest that the im- level in nasal mucosa was associated

mune environment in which the virus with RSV infection, this cytokine was

is received may dictate the outcome. diminished during the incubation pe-

Neutrophils are often overlooked Viral replication No viral replication Viral replication and riod in these people, again underpin-
as mediators of the immune re- and symptoms
no symptoms ning the importance of the timing of

sponse to viruses, even though they Super-spreader? these responses in dictating outcomes.

are the predominant immune cell in The role of IL-17 as an indirect

the lungs of individuals with RSV- neutrophil chemoattractant is estab-
induced bronchiolitis (4) and de- ? lished, however, the exact source of

spite measurements of neutrophil- this cytokine in the nasal mucosa was

associated mediators in the lung cor- not determined by Habibi et al. Both

relating with RSV disease severity innate (e.g., gd T cells) and adaptive

(5). Neutrophils have been shown to (e.g., CD4+ T cells) lymphocytes have

exacerbate epithelial cell damage but been shown to be the predominant

reduce viral titers in RSV infection producers of IL-17 (10), and airway ep-

in vitro, demonstrating how their ithelial cells express the IL-17 receptor.

presence can alter the course of the A role for IL-17 in immune responses

infection once it has commenced (6). IL-17 LCN2 MPO Epithelium Lymphocyte Neutrophil to bacterial infection has been shown

Furthermore, neutrophils express (11). Yet, whether IL-17 (unlike its close

most Toll-like receptors (7), which recog- RSV infection. In mouse models, preinfection relative IL-22) has a role in epithelial homeo-

nize pathogens, and they have been shown expansion of lung neutrophil numbers with stasis remains unclear. Further studies to de-

to respond to other single-stranded RNA C-X-C motif chemokine ligand 1 (CXCL1) led termine whether IL-17 plays an active role in GRAPHIC: A. KITTERMAN/SCIENCE

viruses, such as influenza A virus (8). Thus, to increased RSV infection–associated weight mucosal homeostasis and in creating an RSV-

it is likely that neutrophils can play an ac- loss, which was partially rescued by blocking permissive milieu is warranted, especially as

tive part in immune responses to other viral neutrophil recruitment to the lung. This sug- it could allow patient risk stratification.

infections, including RSV. gests that an aberrant inflammatory milieu The capacity to determine the suscep-

created by activated neutrophils is necessary tibility to viral infection on an individual

Centre for Inflammation Research, University of Edinburgh, to drive symptomatic RSV infection. This is level has never been so attractive, given the
Edinburgh, UK. Email: [email protected] supported by the finding of higher preinoc- global impact of the severe acute respiratory

166 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

Published by AAAS

syndrome coronavirus 2 (SARS-CoV-2) pan- INFECTIOUS DISEASE
demic. Undoubtedly, a number of similarities
can be drawn between the viral illnesses in- Inhibiting Ebola virus and
duced by RSV and SARS-CoV-2. Both of these SARS-CoV-2 entry
enucleated RNA viruses cause a more severe
infection in men, patients with underlying Screening identifies CD74 as a cellular antiviral protein
immunosuppression, and those with chronic against Ebola virus and SARS-CoV-2
cardiovascular disease (12, 13). However,
the age distribution of the severe spectrum By Alexandra I. Wells1,2 and Carolyn B. Coyne1,2 which CD74, previously only associated with
of disease is somewhat different. Although antigen presentation, directly inhibits EBOV
both viruses can severely affect older people, T he mechanisms by which cells defend and SARS-CoV-2 entry into host cells.
SARS-CoV-2 does not appear to be as patho- against many viruses remain largely
genic in younger children, albeit infants are unknown. Defining these mechanisms Viruses must gain entry into the host cell
still at risk (14, 15). Whether the findings of is important not only for understand- to replicate. In the case of EBOV, an envel-
Habibi et al. therefore apply to other respira- ing viral pathogenesis but also for oped virus, virions are internalized by mac-
tory viruses, or indeed other age groups, re- informing the development of anti- ropinocytosis. Once virions reach endosomes,
mains to be elucidated. viral therapeutics. The concerted efforts of host cathepsin proteases cleave viral glyco-
antiviral factors within cells are central to proteins. The glycoproteins then fuse with
Much of our understanding of immune host cell defense. Without these factors, the the lysosomal membrane, which is followed
responses to pathogens, including viral cell remains defenseless against potentially by release of the viral genome into the host
pathogens, has been dissected during infec- harmful pathogens. Understanding how the cell cytoplasm, where viral replication can oc-
tion stages. From a population perspective, cell defends itself is particularly important cur (2). Thus, cathepsin-mediated cleavage is
however, prevention and risk stratification for viruses that have the potential to affect a critical step in the entry of many enveloped
remain the cornerstone for improving out- global health, such as Ebola virus (EBOV) viruses, including EBOV, into the host cell.
comes, whether from established and en- and severe acute respiratory syndrome coro-
demic pathogens such as influenza viruses navirus 2 (SARS-CoV-2). On page 241 of this Similar to EBOV, coronaviruses, includ-
and RSV, or from emerging pathogens such issue, Bruchez et al. (1) developed a transpo- ing SARS-CoV-2, are enveloped viruses that
as SARS-CoV-2. This study also identified a son screening approach in a human osteo- undergo a series of entry steps culminating
subgroup of people who developed asympto- sarcoma cell line to identify a mechanism by in genome release. Coronavirus entry also re-
matic RSV replication. Dissecting the mecha- quires delivery of incoming viral particles to
nisms and immune responses that also allow host lysosomes, where the coronavirus spike
this outcome would greatly enhance our ca-
pacity to control the spread of viral patho- Ebola virus cell entry
gens on a global scale.
Normal cellular entry (left) of Ebola virus (EBOV) involves binding to cells expressing DC-SIGN
The findings of Habibi et al. provide a (dendritic cell–specific ICAM-3–grabbing non-integrin 1) and TIM1 (T cell immunoglobulin mucin receptor 1),
strong start to further our understanding of macropinocytosis, and cathepsin-mediated cleavage of the viral glycoproteins. Together with NPC1
how the immune landscape before an insult (Niemann-Pick C1), glycoprotein cleavage allows fusion with endosomal membranes and genome release
is just as important in shaping outcomes as into the cytoplasm. However, CIITA (class II major histocompatibility complex transactivator) up-regulates
the responses to the pathogen itself (see the the CD74 p41 isoform, which inhibits cathepsins and prevents genome release into the cytoplasm (right).
figure). It is a reminder too, of the dynamic
complexity of the immune system, and of the EBOV
work that lies ahead. j
DC-SIGN TIM1 Internalization Internalization
REFERENCES AND NOTES NPC1
1. P. L.Acosta, M.T. Caballero, F. P. Polack, Clin.Vaccine Cathepsin Glycoprotein
Immunol. 23, 189 (2015). Receptor Endosome processing
2. W. P. Glezen, L. H.Taber,A. L. Frank,J.A. Kasel, Am.J. Dis. attachment Glycoprotein inhibited
Child. 140, 543 (1986). processing
3. M. S. Habibi et al., Science 370, eaba9301 (2020). Lysosome Endolysosome
4. M. L. Everard et al., Arch. Dis. Child. 71, 428 (1994).
GRAPHIC: KELLIE HOLOSKI/SCIENCE 5. K.Yasui et al., Pediatr. Int. 47, 190 (2005). Genome CIITA CD74 CD74
6. Y. Deng et al., J.Virol. 94, e02161 (2020). release Transport p41
7. F. Hayashi,T. K. Means,A. D. Luster, Blood 102, 2660 vesicle
(2003).
8. J. P.Wang et al., Blood 112, 2028 (2008).
9. F. Kirsebom, C. Michalaki, M.Agueda-Oyarzabal,
C.Johansson, Sci. Rep. 10, 1110 (2020).

10. S.J. Gurczynski, B. B. Moore, Am.J. Physiol. Lung Cell.
Mol. Physiol. 314, L6 (2018).

11. K. Chen et al., Cell Host Microbe 20, 596 (2016).
12. E.J.Williamson et al., Nature 584, 430 (2020).
13. A. R. Falsey, P.A. Hennessey, M.A. Formica, C. Cox,

E. E.Walsh, N. Engl.J. Med. 352, 1749 (2005).
14. O.V. Swann et al., BMJ 370, m3249 (2020).
15. T. Shi et al., Lancet 390, 946 (2017).

ACKNOWLEDGMENTS

S.R.W. holds a Wellcome Trust Senior Clinical Fellowship
(209220).A.S.M. holds a Wellcome Trust Postdoctoral
Training Clinical Fellowship (110086).

10.1126/science.abe3685

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INSIGHTS | PERSPECTIVES

protein is cleaved by cathepsins to facilitate do not bind peptides prior to trafficking. NEUROSCIENCE
fusion between virus and host membranes Thus, without CD74, MHC class II molecules
(3, 4). However, in contrast to EBOV, SARS- are not properly processed, and antigen pre- A new villain in
CoV-2 also requires the activity of transmem- sentation becomes impaired. neuronal death
brane serine protease 2 (TMPRSS2) to prime
the viral spike protein (5). Thus, despite their Bruchez et al. show that the thyroglobulin A newly discovered
differences in size and shape, EBOV and domain of CD74 is required for its antiviral partnership for glutamate
SARS-CoV-2 rely on similar proteolytic pro- activity. This domain inhibits cathepsins (8). triggers brain toxicity
cesses to gain entry into a target cell. CD74 has four isoforms but only two of them,
p41 and p43, have the thyroglobulin domain. By Susan Jones
Bruchez et al. used a transposon screen The authors show that the p41 isoform is re-
in which transposable elements were in- sponsible for the antiviral activity of CD74 E xcitotoxicity is the process by which the
serted in front of or within genes. This ap- against EBOV entry and inhibits SARS-CoV-2 excitatory amino acid neurotransmit-
proach allowed for tandem gene activation fusion, suggesting a broad antiviral activity ter glutamate causes neuronal toxicity
and inactivation in a single screen. To iden- of CD74 against many cathepsin-dependent (1). A landmark study in 1987 revealed
tify host factors involved in EBOV infection, viruses. These findings highlight the often that Ca2+ influx into neurons through
the authors infected these cells with EBOV shared strategies of distinct viruses that are glutamate N-methyl-D-aspartate recep-
and identified two main “hits,” including co-opted from host cells to promote cell entry. tor channels (NMDARs) could trigger exci-
Niemann-Pick C1 (NPC1), an intracellular totoxicity (2), making Ca2+ ions potential vil-
EBOV receptor that is required for entry, These findings suggest that molecules in- lains as well as functionally critical signaling
thus validating the approach (6). NPC1 is a volved in antigen presentation could also molecules in neurons. On page 191 of this is-
cholesterol transporter in the lysosome and possess direct antiviral activity and that other sue, Yan et al. (3) reveal a newly discovered
is essential for EBOV fusion of the glyco- factors with defined functions may possess mechanism of NMDAR-mediated excitotox-
proteins with the lysosomal membrane and additional roles in antiviral immunity. CIITA icity: a physical interaction with TRPM4,
subsequent genome release. activates antiviral factors that inhibit a broad a transient receptor potential channel (4).
range of viruses, such as human T cell leu- Small-molecule “interface inhibitors” pre-
Additionally, the authors found that activa- kemia virus type 2 (HTLV-2) (9), although vent NMDAR-TRPM4 physical coupling and
tion of the transcription factor major histo- the steps of the viral life cycle that it targets eliminate excitotoxicity in vitro and in vivo.
compatibility complex (MHC) class II trans- differ from those for EBOV and SARS-CoV-2. This mechanism of excitotoxicity does not re-
activator (CIITA) inhibited EBOV infection. During HTLV-2 infection, CIITA acts more quire NMDAR-mediated Ca2+ influx: TRPM4
CIITA is a nucleotide-binding oligomeriza- directly and inhibits the viral transactivator is the new villain. Consequently, excitotoxic-
tion domain–like receptor (NLR). Typically, protein (TAX2), which promotes transcrip- ity can be halted without disrupting physi-
NLRs detect pathogen-associated molecular tion of the viral genome and thus directly ologically crucial NMDAR-mediated Ca2+
patterns (PAMPs) within the cell and trig- inhibits HTLV-2 replication (9). Some viruses signaling. This presents opportunities in the
ger an intracellular antimicrobial signaling have evolved mechanisms to inhibit this re- design of therapeutics for disorders involving
cascade leading to nuclear factor-kB (NF-kB) striction. For example, Epstein-Barr virus excitotoxicity, including stroke, epilepsy, and
nuclear translocation and expression of vari- (EBV), an oncogenic DNA virus, encodes Zta, neurodegeneration.
ous proinflammatory cytokines. Unlike most a protein that directly inhibits CIITA and re-
NLRs, CIITA acts mainly as a transcription sults in down-regulation of MHC class II mol- Glutamate, released at excitatory synapses
factor to promote the expression of other ecules. This potentially allows EBV to escape in the vertebrate brain, binds to NMDARs
genes, including serving as the master regu- recognition from the immune system (10). to induce Ca2+-dependent forms of synaptic
lator of MHC gene expression. MHC presents plasticity (5) and survival-promoting intra-
peptides from either intracellular (MHC class The identification of host factors that could cellular signaling pathways involving CREB
I) or extracellular (MHC class II) proteins to be targeted therapeutically to limit the repli- [cyclic adenosine monophosphate (cAMP)
adaptive immune cells. CIITA induces the cation of broad families of viruses may be an response element–binding protein] (6).
expression of MHC class II genes to initiate effective approach to combat viral-mediated Glutamate can also spill over beyond the syn-
antigen presentation. The authors deter- disease. However, the therapeutic benefits of apse and activate neighboring synaptic and
mined that expression of CIITA was specifi- viral entry inhibitors are likely most effective extrasynaptic NMDARs. Excessive NMDAR-
cally associated with inhibition of cell entry prior to the onset of symptoms and the devel- mediated Ca2+ influx is a widely accepted ex-
by EBOV, thus defining the step of the viral opment of disease, given that by these stages, planation for excitotoxicity (7, 8).
life cycle that CIITA inhibits (see the figure). viral particles have already gained entry into
the cell and begun to efficiently replicate. A hitherto unrelated ion channel, TRPM4,
Bruchez et al. identified CD74 as the CIITA- is activated by cytoplasmic Ca2+ and is per-
controlled host factor responsible for inhib- REFERENCES AND NOTES meable to monovalent cations Na+ and K+
iting EBOV entry. CD74, often called the in- 1. A. Bruchez et al., Science 370, 241 (2020). (but not to Ca2+), mediating membrane de-
variant chain or Ii, is enriched in immune cell 2. C. L. Hunt et al., Viruses 4, 258 (2012). polarization (9). TRPM4 has previously been
populations and associates with MHC class 3. J. Shang et al., Proc. Natl.Acad. Sci. U.S.A. 117, 11727 linked to neuronal death: In mice, inhibition
II. It localizes to endoplasmic reticulum (ER) (2020). of TRPM4 reduces neurodegeneration, and
membranes and facilitates MHC class II ex- 4. T. Heald-Sargent,T. Gallagher, Viruses 4, 557 (2012).
port from the ER to vesicles that fuse with 5. M. Hoffmann et al., Cell 181, 271 (2020). Department of Physiology, Development and
the late endosome, resulting in trafficking to 6. J. E. Carette et al., Nature 477, 340 (2011). Neuroscience, University of Cambridge, Cambridge, UK.
the cell surface (7). CD74 also blocks the pep- 7. O. Bakke, B. Dobberstein, Cell 63, 707 (1990). Email: [email protected]
tide-binding groove so that MHC molecules 8. M. Mihelič et al., J. Biol. Chem. 283, 14453 (2008).
9. C. Casoli et al., Blood 103, 995 (2004).
1Department of Pediatrics, University of Pittsburgh School
of Medicine, Pittsburgh, PA, USA. 2Center for Microbial 10. D. Li et al., J. Immunol. 182, 1799 (2009).
Pathogenesis, UPMC Children’s Hospital of Pittsburgh,
Pittsburgh, PA, USA. Email: [email protected] ACKNOWLEDGMENTS

A.I.W. is supported by NIH T32-AI060525 and NIH
F31-AI149866, and C.B.C. is supported by NIH AI081759,
AI150151,AI145828, and AI145296.

10.1126/science.abe2977

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genetic deletion of Trpm4 protects Disrupting glutamate receptor interactions suggests that NMDAR-TRPM4 com-
against glutamate excitotoxicity (10). plexes would only form extrasynap-
Synaptic N-methyl-D-aspartate receptor channels (NMDARs), activated tically, offering a satisfying explana-
Yan et al. demonstrate a physical by glutamate release and coincident membrane depolarization,

interaction between NMDARs and trigger neuroprotective signaling pathways involving phosphorylated tion for this puzzle.

TRPM4 in hippocampal cell cultures cAMP-responsive element–binding protein (pCREB). Extrasynaptic Considerable research effort

and brain tissue from mice. NMDARs NMDARs that are activated by synaptic glutamate spillover interact with has focused on the role of Ca2+ in

are typically composed of GluN1, transient receptor potential monovalent cation channel 4 (TRPM4), NMDAR-mediated excitotoxicity. The

GluN2, and sometimes GluN3 sub- triggering excitotoxic cell death. Blocking NMDAR-TRPM4 binding study of Yan et al. introduces a new
units (11). TRPM4 specifically inter- with an N/T inhibitor eliminates neuronal death signaling and enables villain, TRPM4. This requires reeval-
acts with GluN2A and GluN2B, but neuroprotective synaptic signaling. uation of the role of NMDARs in neu-

not GluN2C/D, GluN1, or GluN3. The ronal death. It may redirect research

site of NMDAR-TRPM4 interaction efforts away from Ca2+ and toward

was narrowed down to a cytoplasmic physical interactions of NMDARs,

region of TRPM4, which the authors and it could provide another argu-

call TwinF. They further identify a ment against developing NMDAR

highly conserved isoleucine-rich cy- Glutamate antagonist and channel blocker

toplasmic sequence in GluN2A and therapies. It is unknown whether

GluN2B to which TwinF binds; they the NMDAR-TRPM4 interaction will

name this I4. NMDAR prove to be the primary (or even ex-
A TwinF peptide used to block clusive) excitotoxicity mechanism
Ca2+ in a broader range of neurons. For
NMDAR-TRPM4 interaction was

neuroprotective in three assays of example, neurodegeneration in

cell death: (i) NMDAR-evoked exci- Huntington’s and Parkinson’s dis-

totoxicity of neuronal cultures, (ii) TRPM4 N/T eases affects the basal ganglia (14),
oxygen-glucose deprivation–evoked inhibitor whereas Yan et al. studied hippo-
cell death in neuronal cultures, and campal neurons. There is evidence
(iii) a small but significant reduc- pCREB for acute and chronic excitotoxicity
tion in ischemic brain damage in immediate early in human neurological disorders
gene expression

vivo after middle cerebral artery (8), and so it may be illuminating to

occlusion (MCAO) in mice. Small- screen postmortem human brains

molecule inhibitors that target the Cell death Neuroprotection from patients with neurodegenera-
precise NMDAR-TRPM4 interaction, tive diseases for NMDAR-TRPM4 in-

called compounds 8 and 19, were identified. ing. A surprising finding is that blocking the teractions. If higher amounts of interaction

In the mouse MCAO model and in retinal NMDAR-TRPM4 interaction with TwinF or are seen compared with healthy subjects, can

degeneration induced by NMDA (the selec- small-molecule inhibitors has no effect on small-molecule protein interaction inhibitors

tive NMDAR agonist for which the receptor normal synaptic NMDAR channel function be designed to produce a sufficiently robust

was named), intraperitoneal delivery of com- recorded in hippocampal CA1 pyramidal yet safe disruption? Another intriguing ques-

pound 8 offered neuroprotection—a small neurons in mouse brain slices. Nor is there tion is whether NMDAR-TRPM4 interaction

but significant reduction in infarct volume any effect on NMDAR-mediated Ca2+ influx is triggered under normal physiological con-

and cell loss, as well as reduction in NMDAR- and signaling in vitro. TRPM4 channel activ- ditions and plays an important functional

TRPM4 interaction by as much as 38%. Thus, ity is also unaffected by blocking NMDAR in- role, or is instead purely a pathological re-

these small and simple molecules could po- teraction. Conventional NMDAR antagonists sponse to injury. After more than 30 years

tentially be delivered systemically to patients. typically impair cognitive function (13), most of research, perhaps Ca2+ signaling will ulti-

Rapid delivery would be required in acute likely by blocking NMDAR-mediated synaptic mately be shown to have little importance in

excitotoxic injury—for example, after stroke transmission, Ca2+ influx, and plasticity (5). excitotoxicity—to be a hero and not a villain

or epilepsy—whereas in chronic neurodegen- Being able to target excitotoxicity while hav- in neuronal signaling. j

GRAPHIC: KELLIE HOLOSKI/SCIENCE erative diseases, possible contributions of ex- ing no detrimental effect on NMDAR ionic REFERENCES AND NOTES
citotoxicity to disease progression (8) might current flux or calcium permeability in vitro
be mitigated over a longer time course. constitutes an important step. It remains to 1. J.W. Olney, Science 164, 719 (1969).
be confirmed that the small-molecule inhibi- 2. D.W. Choi, J. Neurosci. 7, 369 (1987).
The authors hypothesize that NMDAR- tors have no detrimental effects in vivo. 3. J.Yan et al., Science 370, eaay3302 (2020).
TRPM4 coupling triggers “CREB shutoff” 4. P. Launay et al., Cell 109, 397 (2002).
(CREB dephosphorylation) (6, 12). TwinF A physical coupling between TRPM4 and 5. C. Lüscher, R. C. Malenka, Cold Spring Harb. Perspect.
and compounds 8 and 19 appear to “de- NMDARs in mediating excitotoxicity ex-
toxify” NMDAR signaling by preventing plains a conundrum in NMDAR research: Biol. 4, a005710 (2012).
CREB shutoff. In addition, TwinF reduces why NMDARs located at synapses appear 6. G. E. Hardingham, H. Bading, Nat. Rev. Neurosci. 11, 682
NMDAR-induced mitochondrial membrane to mediate prosurvival signaling, whereas
dysfunction. By disrupting NMDAR-TRPM4 NMDARs located away from the synapse (2010).
coupling, harmful signaling pathways are si- appear to prevent this and indeed trigger 7. M.Arundine, M.Tymianski, Cell Calcium 34, 325 (2003).
lenced while neuroprotective signaling path- prodeath signaling pathways (6, 8, 12, 14). 8. J. Lewerenz, P. Maher, Front. Neurosci. 9, 469 (2015).
ways are spared (see the figure). Previous explanations for this include the 9. R. Guinamard, C. Simard, L. Sallé, in Encyclopedia of
subcellular localization of different signaling
The mechanism by which physical cou- molecules or different concentrations of Ca2+ Signaling Molecules, S. Choi, Ed. (Springer, 2016).
pling of NMDAR-TRPM4 brings about such influx at synaptic versus extrasynaptic sites. 10. B. Schattling et al., Nat. Med. 18, 1805 (2012).
neuroprotective effects is not yet elucidated, 11. D.J.A.Wyllie, M. R. Livesey, G. E. Hardingham,

Neuropharmacology 74, 4 (2013).
12. G. E. Hardingham,Y. Fukunaga, H. Bading, Nat. Neurosci.

5, 405 (2002).
13. S.A. Lipton, Nat. Rev. Drug Discov. 5, 160 (2006).
14. M. P. Parsons, L.A. Raymond, Neuron 82, 279 (2014).

but it does not appear to involve Ca2+ signal- Because TRPM4 is absent from synapses, this 10.1126/science.abe2791

SCIENCE sciencemag.org 9 OCTOBER 2020 • VOL 370 ISSUE 6513 169

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INSIGHTS | PERSPECTIVES

QUANTUM MATERIALS

Layer-cake 2D superconductivity

An easy-to-synthesize quantum material may help unveil quantum effects

By Leslie M. Schoop transition (6), which is an early example of a single, unprotected layer. This feature

a “topological” phase transition whose dis- is manifested by the mobility of electrons

M aterials science historically has covery was awarded the 2016 Nobel Prize within the protected NbS layer, which
had an immense impact on hu- in Physics. 2
manity, as entire periods of time,
such as the Bronze or Iron ages, Although materials that exhibit 2D is three orders of magnitude higher than
have been named after materials superconductivity are known, imperfec-
(1). In the modern era, a new class tions in the crystals have impeded study. what has been reported in the unprotected
of materials called quantum materials has Because 2D materials are only a few atoms
thick, they often suffer from degradation counterpart. In addition, the BKT transition

can be observed in Ba Nb S because of the
6 11 28.

high purity of the NbS layers.
2
The beauty of this material also lies in

started to affect people’s lives. Quantum upon exposure to air or from defects that the natural growth of the heterostructure,

materials are broadly defined as materi- result from exfoliation. For these reasons, as if the aforementioned layer cake could

als whose electronic or magnetic behavior 2D materials are usually manually encap- be baked by merely mixing the chocolate

cannot be explained by classical physics sulated with protecting layers, typically and batter in a bowl and putting the mix-

(2). Discoveries of quantum materials with boron nitride (7). To create a system for ture in an oven with the two components

distinct or improved properties are often studying the pure physics of 2D supercon- naturally separating during the baking

followed by a surge of research, resulting ductivity, a known material can be made process. This makes the synthesis process

in either the discovery of new physics, as pure as possible, or a new material can much less labor-intensive than adding each

or in applications, such as in layer manually, as is necessary

low–power consumption elec- when protecting 2D crystals

tronics, sensing, photodetec- Protected 2D layers with boron nitride. Because of
tion, high-speed electronics, or the ease of synthesis, different
quantum information science Alternating layers of superconducting NbS2 and a Ba3NbS5 spacer allow types of layered materials may
(3). On page 231 in this issue, high electron mobility in the NbS2 while also protecting it. This creates be developed where the 2D
Devarakonda et al. report the a “layer cake”– like structure that permits clean superconducting behavior. layers are naturally protected

synthesis of a highly inter- Spacer layer by their environment. The 2D
esting quantum material (4), layer would not always have to

which may facilitate the study be a superconductor. Different

of quantum effects that so far types of quantum materials

have been obscured. are also possible. One example

Superconductors are a class might be topological insula-

of fascinating quantum mate- tors, which belong to a class of

rials with properties that in- Superconducting layer quantum materials with prom-

spired dreams of applications Sulfur (S) Niobium (Nb) Barium (Ba) ise for several applications, one
without power loss, such as example being quantum com-

high-speed, levitating trains. puting (8). The authors’ dis-

These dreams have in part been realized be designed. Although purifying materi- covery suggests a much simpler alternative

through development of materials that als is costly and time-consuming, devel- to exfoliated nanodevice fabrication. The

superconduct at high enough tempera- oping new materials presents a host of key question is whether this strategy will

tures for cooling of liquid nitrogen instead other challenges. The discovery of clean easily extend to other materials beyond

of helium, which is expensive and sparse 2D superconductivity in Ba Nb S by Ba Nb S . j GRAPHIC: N. DESAI/SCIENCE ADAPTED FROM (4)
(5). The discovery of these high–critical 6 11 28 6 11 28
temperature superconductors created a
fascinating puzzle. The superconductiv- Devarakonda et al. opens the door to a bet- REFERENCES AND NOTES
ity of these materials is “unconventional,”
meaning that the mechanism is not fully ter understanding of 2D superconductivity 1. N.A. Spaldin, VSH-Bull. no. 2 (August 2017), p.11.
understood. One way to shine light on the 2. B. Keimer,J. E. Moore, Nat. Phys. 13, 1045 (2017).
physics behind the superconductivity is to and its associated quantum phenomena. 3. Y.Tokura, M. Kawasaki, N. Nagaosa, Nat. Phys. 13, 1056
reduce the dimensionality of the materials.
Two-dimensional (2D) superconductors The material is an intrinsic heterostruc- (2017).
4. A. Devarakonda et al., Science 370, 231 (2020).
ture consisting of alternating layers of the 5. R.J. Cava, J.Am. Ceram. Soc. 83, 5 (2000).
6. A. M. Goldman, in 40 Years of Berezinskii–Kosterlitz–
2D superconductor NbS and an electroni-
2 Thouless Theory (World Scientific, 2013), pp. 135–160.
7. K. S. Novoselov et al., Science 353, aac9439 (2016).
cally uninteresting spacer layer, Ba NbS
35

(see the figure). Think of the material as

a layer cake with a thin layer of chocolate

simplify the problem and also offer ac- repeatedly inserted between thicker layers 8. S.D. Sarma, M. Freedman, C. Nayak, npj Quantum Inf. 1, 1
cess to many other unsolved mysteries of of cake. The chocolate is the superconduc- (2015).

condensed matter physics. These include tor (NbS ) and the dough is the spacer layer ACKNOWLEDGMENTS
the Berezenskii-Kosterlitz-Thouless (BKT) 2
The author acknowledges support by the Gordon and Betty
that protects the chocolate from cracking or Moore Foundation through grant GBMF9064.

being attacked by air or moisture. Because

Department of Chemistry, Princeton University, Princeton, of this protection, the NbS layer exhibits 10.1126/science.abd4225
NJ 08544, USA. Email: [email protected] 2

much cleaner 2D superconductivity than

170 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

Published by AAAS

ELECTRON MICROSCOPY images) and propose that as many as 800 im-
ages could be obtained with an appropriately
Better, faster, and even cheap configured microscope.

An inexpensive gold grid with submicrometer holes A second approach to increasing through-
minimizes protein sample movement put that Naydenova et al. addressed is to in-
crease the data quality by minimizing the in-
ILLUSTRATIONS: MICAH RAPP By Micah Rapp and Bridget Carragher the pharmaceutical drug discovery pipeline formation loss from both radiation damage
(11). These timelines also present a barrier and sample movement. They present a fasci-
C ryo–electron microscopy (cryo-EM) for academic research. Increasing through- nating and exhaustive analysis showing that
enables access to structures of pro- put will lower costs and enable more re- the primary cause of specimen movement
teins that were previously intractable, searchers to use cryo-EM to solve structures during imaging is a buckling of the vitrified
including large protein complexes and accelerate scientific discovery. ice layer. On the basis of these insights, they
such as the ribosome (1), integral created a support film with an optimal sub-
membrane proteins (2, 3), and highly Naydenova et al. propose a new specimen strate thickness relative to the hole diameter,
heterogeneous or conformationally dynamic support film, dubbed “HexAuFoil,” that pro- which reduces the total movement of the
systems (4). Each sample is a vitrified layer of vides many advantages over conventional sample to <1 Å during the course of an expo-
protein suspended over a support film on an sure. They could mathematically extrapolate
EM grid. Despite recent advances in cryo-EM Grid schematics the data to a three-dimensional map before
(the so-called “resolution revolution”) (5, 6), the onset of radiation damage.
major barriers persist, including loss of the The sample holder developed by Naydenova et al. for
highest-resolution information through elec- cryo-EM has a dense packing of holes 200 to 300 nm Standard support films have recently been
tron beam damage and blurring from sam- in diameter for supporting vitrified proteins. used to obtain the first truly atomic-level
ple movement (which is most pronounced cryo-EM reconstructions (12, 13) of apofer-
initially when the sample is least damaged). Conventional holders with holes 1 to 2 µm in diameter ritin, a very stable test specimen. The ad-
Typically, tens of thousands of images must are less stable and lead to more sample movement. vances developed by Naydenova et al. should
be averaged to compensate for signal loss. bring this goal closer for less well-behaved
On page 223 of this issue, Naydenova et al. support films. In cryo-EM, images are typi- proteins. Although software is also now
(7) describe a new specimen support film cally taken of proteins embedded in a layer available to correct for the effects of beam-
(see the figure) that not only improves both of vitrified ice suspended over a support induced movement (14), this approach does
the quality of images and the efficiency of films containing holes ~1 to 2 mm in diam- not provide the concomitant benefit of faster
collection, but also does so at a relatively low eter. By making these holes smaller (200 to data collection.
price. 300 nm in diameter) and packing them more
tightly together (a nontrivial feat), they sub- High-resolution cryo-EM is still in a state
Like much of society, the strengths and stantially increased data throughput. They of active method development, its true po-
weaknesses of cryo-EM have been high- obtained 200 images for every microscope tential not yet realized. Thus, it is exciting
lighted by the coronavirus disease 2019 stage movement (versus a typical 10 to 30 that Naydenova et al., with one accessible,
(COVID-19) pandemic. Structural biology inexpensive hardware development, will al-
has contributed to our understanding of se- low all practitioners to acquire better images
vere acute respiratory syndrome coronavirus much more rapidly as soon as the grids be-
2 (SARS-CoV-2), with more than 330 struc- come commercially available. The promise is
tures deposited into the Protein Data Bank of a future of high-resolution structures of
since early March. At the time of writing, 264 a wide range of proteins, in an ensemble of
of those structures were produced by x-ray conformational or compositional states (15),
crystallography and 72 by cryo-EM. The as- produced with much higher throughput. j
tonishing throughput of crystallography was
demonstrated in recent work on the main REFERENCES AND NOTES
SARS-CoV-2 protease, where ~1500 datasets
were collected in a single day (8). 1. A. Brown, S. Shao, Curr. Opin. Struct. Biol. 52, 1 (2018).
2. Y. Cheng, Curr. Opin. Struct. Biol. 52, 58 (2018).
In contrast, cryo-EM datasets typically re- 3. M. Dong et al., Nat. Commun. 11, 4137 (2020).
quire on the order of 24 hours of data collec- 4. T. Nakane, D. Kimanius, E. Lindahl, S. H.W. Scheres, eLife
tion, even though the process is largely au-
tomated (9). High-end microscopes are not 7, e36861 (2018).
only under extraordinary demand, but are 5. W. Kühlbrandt, Science 343, 1443 (2014).
also associated with very high capital and 6. Y. Cheng, Science 361, 876 (2018).
annual maintenance costs (10). These differ- 7. K. Naydenova, P.Jia, C.J. Russo, Science 370, 223
ences have made x-ray crystallography better
suited to the rapid turnaround required by (2020).
8. A. Douangamath et al., bioRxiv 118117 (2020).
Simons Electron Microscopy Center, New York Structural 9. D. Lyumkis, J. Biol. Chem. 294, 5181 (2019).
Biology Center, New York, NY 10027, USA, and Department of 10. K. Naydenova et al., IUCrJ 6, 1086 (2019).
Biochemistry and Molecular Biophysics, Columbia University, 11. G. Scapin, C. S. Potter, B. Carragher, Cell Chem. Biol. 25,
New York, NY 10032, USA. Email: [email protected]
1318 (2018).
12. T. Nakane et al., bioRxiv 110189 (2020).
13. K. M.Yip, N. Fischer, E. Paknia,A. Chari, H. Stark, bioRxiv

106740 (2020).
14. D.Tegunov, L.Xue, C. Dienemann, P. Cramer,J. Mahamid,

bioRxiv 136341 (2020).
15. A. Dance, Nat. Methods 17, 879 (2020).

ACKNOWLEDGMENTS

Supported by NIH grants GM103310 and OD019994 and
Simons Foundation grant SF349247.

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INSIGHTS | PERSPECTIVES

VIEWPOINT: COVID-19

Contextualizing bats as viral reservoirs

Preventing zoonotic emergence from bats requires integrative research

By Daniel G. Streicker1,2 and Amy T. Gilbert3 Marburg virus, SARS-coronavirus (SARS- and environmental conditions. Identifying
CoV), and MERS-CoV are thought to cause the eco-evolutionary determinants and range
C oronavirus disease 2019 (COVID-19) subclinical infections in the presumed natu- of antiviral defenses might help identify un-
is the latest in a distressing tally of ral bat hosts (Egyptian fruit bats, Rousettus reported reservoirs of zoonoses but requires
viral infections—including Ebola, aegyptiacus, for Marburg virus and horse- expanding research beyond the relatively few
Nipah, rabies, severe acute respira- shoe bats, Rhinolophus spp., for both CoVs) bat species known to transmit zoonoses.
tory syndrome (SARS), and Middle but immunopathology in other vertebrates.
East respiratory syndrome (MERS)— Over evolutionary time scales, limited inflam- Whether features of bat immunology pre-
that have evolutionary origins or epidemio- matory responses in bats, together with high dictably translate into functionally distinct
logical associations with bats. This seeming population densities and gregarious social antiviral strategies is unresolved. For ex-
preponderance of zoonoses has propelled behaviors in some species that may facilitate ample, the popular notion that bats tolerate
bats from biomedical obscurity to the fore- virus transmission, could have selected for vi- virus infections is supported by experimental
front of global health. Immunological traits ruses that cause severe disease in incidental infections of bats with Marburg virus, Ebola
have been proposed to allow bats to control hosts that lack analogous defenses. virus, and MERS-CoV. Conversely, other vi-
viruses differently from other animals. How- ruses that may be lethal to humans—includ-
ever, incomplete baselines for broader com- Peculiarities in bat immune systems that ing lyssaviruses, Tacaribe virus, and Lloviu
parisons across vertebrates and extensive plausibly alter viral interactions are increas- virus (human pathogenicity unknown)—are
immunological variation among bat species ingly recognized (2). Whether bats are ex- also apparently lethal to bats, including pu-
casts uncertainty on their distinctiveness as ceptional in this respect is unclear because tative reservoir hosts. Sublethal effects of
viral reservoirs. Moreover, common percep- knowledge of vertebrate immune systems viruses on wild bats are largely undetectable
tions that bats asymptomatically harbor vi- largely derives from inbred mice or immor- because longitudinal monitoring of individu-
ruses more often than other animals and that talized cells, which diverge substantially from als is only possible in philopatric species,
their viruses are more diverse or pose system- wild relatives. Fortunately, the rise in genome which live in relatively small groups and can
atically heightened zoonotic risk remain un- sequencing has provided crucial phylogenetic be reliably recaptured. Individual heterogene-
resolved. The search for answers may inspire context to the evolutionary origins of bat im- ities that alter infection outcomes in humans
new approaches to manage disease threats to munity while facilitating comparisons with and other animals—such as age, sex, social
human and animal health. diverse nonmodel species (3). For example, hierarchies, and past and contemporaneous
comparative transcriptomics showed distinct infections—remain virtually unexplored in
Bats (order Chiroptera) comprise ~1400 aspects of innate immunity in little brown bats. Given limited evidence from wild popu-
species that split from the remaining mem- bat (Myotis lucifugus) and large flying fox lations, meta-analyses of experimental infec-
bers of the Scrotifera (carnivores, pangolins, (Pteropus vampyrus) but also in eight other tions might test whether bats systematically
cetaceans, and odd- and even-toed ungulates) mammalian and avian species (4). By charac- manifest less symptomatic disease than other
over 60 million years ago. The capacity for terizing distinct antiviral features across taxa, hosts. Other taxa that are infected with some
true flight, specific to bats among mammals, efforts to contextualize bat immunity might zoonotic viruses but exhibit mild or no symp-
opened diverse trophic niches, making bats inspire new strategies to prevent and treat toms, such as rodents (for example, Lassa vi-
key providers of global ecosystem services, viral zoonoses in humans and animals. rus) and birds (for example, West Nile virus),
including insect pest control, seed dispersal, provide relevant contrasts.
and pollination of agricultural plants. Flight Heightened interest in bat-associated viral
also introduced physiological challenges that zoonoses has also revealed high immuno- Whether bat viruses are disproportionately
transformed bat life history. For example, logical variation among species. For example, zoonotic is an outstanding global health co-
aerial transport of young restricts litter sizes black flying foxes (P. alecto) have an unusually nundrum. A meta-analysis of 2805 host-virus
to one or two pups annually across most spe- contracted interferon-a (IFN-a) locus (genes interactions showed that bats are more likely
cies. The need for multiple bouts of reproduc- that encode components of the innate im- than other mammals to be infected by viruses
tion to maximize fitness therefore favored mune response) and cells that constitutively that also infect humans (7). Yet when analy-
longevity, hypothesized to be mediated by express IFN-a, inducing antiviral activity (5). ses are restricted to hosts that are believed
adaptations to suppress tumors and inflam- However, other bat species have expanded to be important for natural transmission
mation caused by DNA damage (1). IFN-a loci and lack constitutive IFN-a (6). cycles, viral richness among Chiroptera was
Similarly, bat species with increased consti- unexceptional, and they contributed approxi-
Perhaps serendipitously, these mecha- tutive antiviral defenses may do so through mately the number of zoonoses expected for
nisms also limit virus-induced inflammation, differing gene expression pathways (4), and the number of species in this order (8). Thus,
potentially explaining why viruses including the antiviral APOBEC gene family has un- evolutionarily conserved traits of bats seem
dergone bat lineage–specific expansions or unlikely to produce viruses with inflated zoo-
1Institute of Biodiversity, Animal Health and Comparative duplication (3). This implies that some of the notic capability. Heightened susceptibility or
Medicine, College of Medical, Veterinary and Life Sciences, unusual antiviral defenses in bats arose inde- perhaps surveillance may explain why bats
University of Glasgow, Glasgow, UK. 2Medical Research pendently after the evolution of flight. Diver- appear to host a relatively large number of
Council–University of Glasgow Centre for Virus Research, gent immunological repertoires among bat zoonotic viruses.
Glasgow, UK.3U.S. Department of Agriculture, Animal and species may reflect alternative responses to
Plant Health Inspection Service, National Wildlife Research biogeographic variation in viral assemblages Once introduced into the human popula-
Center, Fort Collins, CO, USA. Email: daniel.streicker@ tion, are bat viruses exceptionally dangerous?
glasgow.ac.uk; [email protected]

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One meta-analysis found higher case fatality of bat reservoirs, research should also tackle bats, analogous to ongoing efforts to control
ratios (CFRs) and lower human-to-human the real-world complexity underlying viral Lyme disease in wild mice (13). Historical
transmissibility of bat viruses; however, the zoonotic emergence (see the figure). A first barriers to delivering vaccines at sufficient
extent that these patterns generalize among step may be to identify how intrinsic traits scales to alter viral dynamics in wild bat
bat viruses was uncertain (9). The rabies- of bats and extrinsic factors interact to gov- populations are also diminishing. The rela-
causing lyssaviruses, which comprise ~50% ern viral transmission, community assembly, tive ease of metagenomic sequencing enables
of zoonotic viruses recognized from bats (8), and zoonotic emergence. For example, spa- rapid discovery of naturally occurring, in-
exemplify high CFRs and low transmissibil- tially replicated metagenomic sequencing in nocuous, and species-specific bat viruses that
ity among humans but, being lethal across all vampire bats (Desmodus rotundus) found no might be engineered into transmissible vac-
mammals, do not fit the emerging paradigm evidence that larger colonies sustain more cines targeting zoonoses in wild bats. This
of tolerance in bats contrasted with virulence viruses but revealed elevational gradients idea has empirical precedents from efforts
in humans. Deviations such as SARS-CoV-2 and age biases in viral diversity (11). In fly- to vaccinate wild rabbits against myxomato-
(low CFR and high transmissibility) and the ing foxes, longitudinal monitoring showed sis and rabbit hemorrhagic disease (14). The
ebolaviruses (moderate CFR and transmissi- pulsed shedding of multiple paramyxovi- traits expected to facilitate virus transmis-
bility) highlight further complexity. ruses (a virus family associated with several sion in some bats, such as gregariousness and
emerging zoonoses), potentially arising from flight, could support live vaccine dissemina-
If the virulence of bat viruses is systemati- physiological stress induced by acute food tion, and naturally slow demographic turn-
cally increased, mathematical models fit to in shortages (12). Understanding virus coin- over would help to maintain vaccine-induced
vitro experiments provide a possible explana- fection and community dynamics may also population-level immunity, allowing less
tion: Accelerated viral propagation with lim- reveal recombination opportunities that po- frequent interventions (15). Such potentially
ited cellular morbidity might favor chronic transformative strategies require rigorous
investigation into efficacy, safety, and ecologi-
Dimensions of zoonotic emergence cal impacts as well as overcoming barriers to
societal acceptance. Viruses such as rabies
Bat viruses emerge through currently unpredictable interactions of evolutionary and ecological forces. Intrinsic virus, Marburg virus, and henipaviruses—for
features of bat immune systems have been shaped by bat life history and past viral interactions. Anthropogenic which bat reservoirs are known, host and
perturbations may alter host-virus interactions at the individual or population levels while breaking down viral genomes are available, and transmis-
historical barriers between species, culminating in viral emergence. sion to humans and/or animals occurs with
measurable frequency—can serve as tractable
Land use and Urbanization Wildlife trade Bat persecution and important models to evaluate and refine
climate change (culling, dispersal) candidate interventions.

Evolutionary Intrinsic Inter-species Human-animal Zoonotic Viral emergence from bats is largely un-
drivers factors variation interface opportunities predictable and unpreventable. Solutions re-
Life span (Social structure, quire qualitative and quantitative expansions
(Resistance, population biology, (Cross-species Direct contacts over current practice in bat research, which
Flight tolerance, dispersal, virus exposure) (bites, butchering) rarely considers heterogeneities among indi-
shedding) coevolution) viduals, populations, and species. This vari-
Biogeographic Environmental ability can reveal the drivers and phenotypic
context Individual transmission importance of bat-virus interactions as well
heterogeneity (fomites, excretions) as whether they generalize in ways that might
(Age, sex, aid surveillance or management of zoonotic
coinfections) Intermediate threats. Given the costs of the COVID-19 pan-
hosts (especially demic, the need for an ambitious research
Altered infection Altered frequency or nature peridomestic) agenda is more evident now than ever. j
dynamics in bats of cross-species exposure
Reservoir host REFERENCES AND NOTES
Zoonotic emergence geographic range 1. G.Zhang et al., Science 339, 456 (2013).
2. J. N. Mandl et al.,Front. Immunol. 9, 2112 (2018).
GRAPHIC: JOSHUA BIRD/SCIENCE subclinical infections in bats but acute in- tentially enable emergence. Anticipating how 3. D.Jebb et al., Nature 583, 578 (2020).
fections in other hosts (10). Although the anthropogenic perturbations such as land 4. A.E.Shaw et al.,PLOS Biol.15,e2004086 (2017).
prediction that bat viruses that cause short- use change, persecution of bats for consump- 5. P.Zhou et al.,Proc.Natl.Acad.Sci.U.S.A.113,2696 (2016).
lived, lethal infections in humans infect bats tion, trade, or from fear, or misguided efforts 6. S.S.Pavlovich et al.,Cell 173,1098 (2018).
chronically remains unconfirmed in vivo, the at disease control will precipitate emergence 7. K.J.Olival et al.,Nature 546,646 (2017).
short time frames and small sample sizes of is a greater challenge. These actions can alter 8. N.Mollentze,D.G.Streicker,Proc.Natl.Acad.Sci.U.S.A.
most experiments make detecting reactiva- both viral transmission among bats and the 117,9423 (2020).
tion of latent viral infections in bats unlikely. frequency of interspecies contacts (including 9. S.Guth et al.Philos.Trans.R.Soc.B Biol.Sci.374,
Ultimately, virulence is an emergent prop- with intermediate hosts) but are conceptually 20190296 (2019).
erty of host and virus interactions. As such, underdeveloped and rarely tested empirically.
determining whether differences among 10. C.E.Brook et al.,eLife 9,e48401 (2020).
species arise from virus-specific phenomena Integrating understanding of the zoonotic 11. L.M.Bergner et al.,Mol.Ecol.29,26 (2020).
within bats, inappropriate responses of naïve process across biomedical, population, and 12. A.J.Peel et al.,Emerg.Microbes Infect.8,1314 (2019).
immune systems, or viral tolerance mecha- ecosystem scales may enable prevention of 13. J.Buchthal et al.Philos.Trans.R.Soc.B Biol.Sci.374,
nisms may require profiling immunological zoonotic emergence by reducing virus cir-
responses and within-host dynamics across culation in bat reservoirs. Knowledge of bat 20180105 (2019).
diverse viruses and host species. genomics and immunity opens the door for 14. J.J.Bull et al.,Trends Microbiol.26,6 (2018).
using genetic editing technologies such as 15. K.M.Bakker et al.,Nat.Ecol.Evol.3,1697 (2019).
Beyond contextualizing the distinctiveness CRISPR to engineer viral resistance in wild
ACKNOWLEDGMENTS

D.G.S. is funded by a Wellcome Trust Senior Research
Fellowship (217221/Z/19/Z).We thank M. Palmarini, S.
Babayan, and M.Viana for discussions.

10.1126/science.abd4559

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INSIGHTS

POLICY FORUM ship of something from an “area beyond na-
tional jurisdiction.” Still, it should be noted
SPACE POLICY that fishing without science-based regula-
tion often leads to overexploitation and even
U.S. policy puts the safe destruction of stocks, and that nations have
development of space at risk responded to these risks by negotiating mul-
tilateral treaties on the management of high-
Promoting national regulation of space mining rather than seas fisheries that result in science-based
multilateral governance risks a “race to the bottom” quotas and sometimes moratoria.

By Aaron Boley1 and Michael Byers2 in NASA’s Artemis lunar program. For many The Artemis Accords have been con-
nations, the chance to have their own astro- demned by Russia as a blatant move to re-
I n September 2020, the U.S. National naut on the Moon is a powerful incentive. make international space law in favor of
Aeronautics and Space Administration the United States. The first casualty of this
(NASA) announced that it is seeking The permissibility of commercial space initiative might therefore be the long and
proposals from private companies to mining has become a central aspect of U.S. stable relationship of space cooperation be-
extract small amounts of regolith from space policy: In 2015, the Commercial Space tween these two nations. Nor is there any
the surface of the Moon. According to Launch Competitiveness Act gave U.S. citi- indication that the United States will involve
NASA Administrator Jim Bridenstine, the zens and companies the right to own and China, another superpower and an increas-
exercise will buttress an interpretation of in- sell space resources under U.S. law. In 2017, ingly capable space actor, in this effort to de-
ternational space law that is favored by the Luxembourg followed suit, adopting legis- velop a new governance regime.
U.S. government: “What we’re trying to do is lation in support of commercial space mining
make sure that there is a norm of behavior and offering subsidies to space mining com- MINING OPPORTUNITIES AND RISKS
that says that resources can be extracted and panies that incorporate there. Other nations The commercial potential of space mining
that we’re doing it in a way that is in compli- might seek to attract companies by offering is receiving most of the attention, but there
ance with the Outer Space Treaty” (OST) (1). minimal regulations and lax enforcement. is also a strong motivation rooted in science
NASA’s move is part of a larger U.S. diplo- Leaving regulation to national governments and exploration. At least 14 national space
matic effort. In April 2020, President Trump thus risks a “race to the bottom” and even agencies have identified in situ resource
signed an executive order (EO) that affirmed the emergence of “flags of convenience.” use (ISRU) as a needed capability for long-
a right of commercial space mining and di- duration missions, including crewed mis-
rected the U.S. State Department to secure The 2020 EO goes further than the 2015 sions to the Moon, Mars, and deep space (2).
the expressed support of U.S. allies. Shortly legislation by explicitly rejecting space as a Artemis will be the first such NASA-led pro-
after, NASA announced a plan for bilateral “global commons” and dismissing the 1979 gram (3). Resources such as ice and water-
Artemis Accords, which, if accepted by many United Nations (UN) Moon Agreement as bearing minerals from the lunar South Pole
nations, could enable the U.S. interpretation irrelevant because it has not been ratified will provide fuel, radiation shielding, and life
of international space law to prevail and by major spacefaring nations. The Moon support for surface and orbital operations.
make the United States—as the licensing Agreement declares the Moon and other The regolith will be mined for construction
nation for most of the world’s space compa- celestial bodies the “common heritage of materials and as a source of hydrogen and
nies—the de facto gatekeeper to the Moon, mankind” and provides a mechanism for oxygen (4). Many asteroids also contain an
asteroids, and other celestial bodies. Because initiating a multilateral negotiation on abundance of water and minerals (5, 6) that
acquiescence is often treated as consent in space mining. could be used to support space operations.
international law, even NASA’s purchase
of regolith would, if not protested by other Most other nations take the view that ISRU will provide new science opportuni-
nations, strengthen the U.S. interpretation. space mining should only be conducted un- ties and unprecedented sampling of celes-
Other nations need to speak up, now. der an international system of regulation, tial bodies. For example, asteroids contain
oversight, and benefit sharing. The 1967 some of the oldest materials in the Solar
The Artemis Accords are to include recog- OST provides the governance framework for System, some of which have experienced
nition of a right to commercial space min- all space activities. Article II reads: “Outer little thermal processing since their incor-
ing subject to national regulation only (i.e., space, including the moon and other celes- poration into parent bodies. The Moon’s
no need for a new multilateral agreement), tial bodies, is not subject to national appro- ice deposits are a partial record of volatile
as well as the right of companies to declare priation by claim of sovereignty, by means of delivery to Earth. However, space mining,
“safety zones” around their operations to use or occupation, or by any other means.” especially if conducted by loosely regulated
exclude other actors. Negotiations with indi- private companies, could hinder science.
vidual NASA partner nations are reportedly The term “national appropriation,” how- For example, water and oxygen could be ex-
under way, with the conclusion of an Artemis ever, is not defined in the OST, making it pos- tracted from astromaterials by pyrolysis (7),
Accord being a prerequisite for participation sible to argue that the extraction and even and, without systematic scientific sampling
the sale of space resources is not prohibited before alteration or consumption, valuable
1Department of Physics and Astronomy, University of and is therefore already permitted. NASA’s information about the Solar System (e.g.,
British Columbia, Vancouver, BC, Canada. 2Department of Bridenstine has drawn an analogy to fish- locked into cosmochemical or mineralogi-
Political Science, University of British Columbia, Vancouver, ing on the high seas, where a fish cannot be cal signatures) could be lost. Analysis to
BC, Canada. Email: [email protected] owned while in the ocean but can be owned maximize resource yields is not generally
as soon as it is caught. The analogy is apt the same as that needed for understanding
because it concerns the acquisition of owner- the Solar System. Inconsistent practices in
resource extraction, a likely result of purely
national regulations, would only exacerbate
the losses in scientific opportunities (8).

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Some of the first efforts at private space gations of stewardship. There are analogies During negotiation of the 1982 UN

exploration have already manifested a here on Earth, including “orphan” oil wells Convention on the Law of the Sea

less than rigorous approach to risk avoid- and abandoned mine tailings. (UNCLOS), the United States demanded

ance. In 2019, the Israeli nonprofit SpaceIL that private companies have access to deep

crashed a robotic lander on the Moon. MANAGING A GLOBAL COMMONS seabed resources beyond the continental

Unbeknownst to SpaceIL, its partner—the Lunar dust, anthropogenic meteoroids, shelf and be answerable to national regu-

Arch Mission Foundation—had placed and the loss of science opportunities are lators only. Most other nations wished the

thousands of nearly indestructible tar- examples of negative externalities that deep seabed to be recognized as “common

digrades on board (9). In 2018, SpaceX could arise because of space mining. Their heritage of mankind,” with mining subject

launched a Tesla automobile on an orbit inadequate consideration can be expected to international regulation and oversight.

that extends past Mars; although no im- when rulemaking and oversight in an area The latter view prevailed, mostly because

pact with Mars is expected, there was an beyond national jurisdiction are left to in- of coordinated negotiating by developing

initial lack of clarity on the mission pro- dividual nations rather than a multilateral nations. The United States has not ratified

file and the potential for the unsterilized regime. The approach being taken by the UNCLOS but accepts its provisions as cus-

payload to encounter Mars (10). tomary international law.

Mining can generate serious op- With its proposed Artemis

erational concerns. Lunar dust is Accords, the United States is over-

a known challenge to operations looking best practice with regard

on the Moon. Any surface activity to the sustainable development of

could exacerbate lunar dust migra- space. Instead of pressing ahead

tion, including by lofting dust onto unilaterally and bilaterally, the

trajectories that cross lunar orbits, United States should support ne-

such as that of NASA’s proposed gotiations on space mining within

Lunar Gateway (11). Moreover, the UN Committee on the Peaceful

without cooperation by all actors, Uses of Outer Space, the same mul-

the limited number of useful lunar tilateral body that drafted the five

orbits could quickly become filled major space treaties of the 1960s

with space debris. and ’70s. Meanwhile, NASA’s ac-

On asteroids, low escape speeds tions must be seen for what they

will make it difficult to prevent the are—a concerted, strategic effort

loss of surface material. Even if full to redirect international space co-

enclosures are used, waste mate- operation in favor of short-term

rial may be purposefully jettisoned. Concept for robotic construction of buildings on the Moon. Lunar mining U.S. commercial interests, with lit-

Mining could also lead to uncon- is envisaged to be necessary for developing such infrastructure. tle regard for the risks involved. j

trolled outbursts of volatile subli-

mation after the removal of surface layers. U.S. government, of bilateral negotiations REFERENCES AND NOTES

Because the asteroids targeted for mining are and purely national regulations, ignores 1. J. Foust,“NASA offers to buy lunar samples to set space
likely to be those with small minimum orbit widely adopted insights into the manage- resources precedent,”SpaceNews, 10 September 2020;
intersection distances, the resulting meteor- ment of common pool resources and global https://spacenews.com/nasa-offers-to-buy-lunar-
oid debris streams could threaten lunar op- commons (8, 15). Multilateral management samples-to-set-space-resources-precedent/.

2. International Space Exploration Coordination Group,

erations as well as satellites in Earth’s orbit takes time and requires compromise but “The global exploration roadmap”(Publication
(12). In a worst-case scenario, a trajectory also internalizes externalities by, for ex- NP-2018-01-2502-HQ, NASA, 2018).
change resulting from mining could eventu- ample, ensuring a degree of peer review 3. NASA,The Artemis Accords: Principles for a safe, peace-
ful, and prosperous future (2020); https://www.nasa.

ally lead to an Earth-impact emergency. with respect to the proposed actions of in- gov/specials/artemis-accords/index.html.
Space missions already provide some dividual governments. The U.S. approach, 4. M. B. Duke, L. R. Gaddis, G.J.Taylor, H. H. Schmitt, Rev.
instead, is an application of basic game
evidence of these risks. In 2019, during the theory—the prisoner’s dilemma—whereby Mineral. Geochem. 60, 597 (2006).
course of Japan’s Hayabusa2 mission, a individual, similarly situated actors, in ne- 5. E.Jarosewich, Meteoritics 24, 323 (1990).
small impactor was used to make a crater gotiations with a more powerful actor, are 6. K. Lodders, H. Palme, H. P. Gail, in Landolt-Börnstein—
on (162173) Ryugu (13). Some of the result-
Group VI Astronomy and Astrophysics,J. E.Trümper, Ed.
(Springer, 2009), vol. 4B, chap. 4.4, pp. 560–630.
7. L. Schlüter,A. Cowley, Planet. Space Sci. 181, 104753

ing anthropogenic meteoroids could begin denied the opportunity to communicate (2020).
reaching Earth during the 2033 apparition. with each other. Of course, U.S. allies are 8. E. Ostrom,J. Burger, C. B. Field, R. B. Norgaard, D.
In 2022, NASA will test its ability to deflect not precluded from coordinating with each
an asteroid by striking (65803) Didymos other as they negotiate with NASA—indeed, Policansky, Science 284, 278 (1999).
B (Dimorphos) with the Double Asteroid coordination is their best strategy—but the 9. K. Shahar, D. Greenbaum, New Astron. 4, 208 (2020).
Redirection Test spacecraft. This impact bilateral context makes this more difficult. 10. National Academies of Sciences, Engineering, and
will produce anthropogenic meteoroids,
We have been here before with different Medicine,“Review and assessment of planetary protec-
tion policy development process”(Consensus Study
Report,The National Academies Press, 2018).
11. P.T. Metzger, paper presented at the Impact of Lunar

with the possibility of immediate delivery to outcomes. In 1945, the United States claimed Dust on Human Exploration Workshop, Houston,TX, 11
Earth (14). Although these risks are small, exclusive jurisdiction over the resources to 13 February 2020.
they demonstrate how easily human actions of the continental shelf located offshore its 12. L. Fladeland,A. C. Boley, M. Byers, paper presented at
the First International Orbital Debris Conference, Sugar

ILLUSTRATION: NASA can change the near-Earth environment. territory. Although novel, the claim quickly Land,TX, 9 to 12 December 2019.
As for the safety zones envisaged in the became part of international law, because its 13. M.Arakawa et al., Science 368, 67 (2020).
framing made the same right available to ev- 14. P.Wiegert, Planet. Sci.J. 1, 3 (2020).
Artemis Accords, these would provide a 15. P. C. Stern, Int.J. Commons 5, 213 (2011).

space actor with many of the benefits of ter- ery coastal nation. Those nations responded

ritory while relieving it of long-term obli- by making the same claim themselves. 10.1126/science.abd3402

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INSIGHTS

A man pauses to watch the sunset in Romania during
a punishing heat wave in August 2019.

the Future explores two prominent science-

based interventions that have been proposed

as potential mitigators of global warming.

Several chapters detail efforts to stabilize

Antarctic and Greenland glaciers by drilling

into their respective bases and pumping out

the meltwater that lubricates their speedy

advance. Several others imagine how early

efforts to restore wildlife corridors might be

scaled up to rewild much of the planet.

Ultimately, however, the book privileges

global politics over geoengineering. For

example, over several pivotal scenes, Mur-

phy works to convince the heads of the

BOOKS et al. world’s largest central banks to back car-
bon coins—monetized credits awarded for

keeping fossil fuels in the ground and for

sequestering atmospheric carbon.

FICTION Climate action in Robinson’s fictional

Plotting a path to a more future comes from strategy sessions in Zu-
rich and from lobbying the Federal Reserve
and the Chinese Ministry of Finance, but

sustainable future it also comes from local initiatives. One
important chapter is simply a list of hun-
dreds of grassroots organizations—from

Persistent political pressure staves off global an Argentine permaculture initiative to a
Zimbabwean ecological land trust—whose

warming in a new climate allegory cumulative impact forces power brokers to
consider alternatives to neoliberalism. Cit-

ing, both as an example and a caution, the

By Carl Abbott official action. She visits him in prison, and revolution that swept through Europe in

they slowly build an unlikely friendship. 1848, the novel envisions a moment when

R enowned science fiction writer Kim May serves as a stand-in for the damaged both governors and the governed realize
Stanley Robinson has long been fas- Earth that Murphy is trying to protect. that a new set of ideas has more power and
cinated by climate-modifying tech- relevance than the old.
nologies such as geoengineering and This is a book of ideas, not a plot-driven
terraforming, but his passion lies page-turner, which advances through 106 Like the protagonists of Robinson’s ear-
short chapters. Some are episodes of tra- lier books, Murphy is a hero because she

in the necessity of political action ditional action—activists take is persistent. Her Ministry for

to achieve a sustainable future. Based in over a Davos meeting and hold the Future pushes, prods, and

an affectionately described Zurich, whose the economic elite captive, Mur- persuades decision-makers to re-

normalcy contrasts with global crisis, the phy escapes from assassins over verse greenhouse gas accumula-

titular Ministry for the Future described an Alpine pass. Interspersed are tion, but even as she retires from

in Robinson’s new book is a small agency loving portraits of landscapes her post, she knows that prog-

within the United Nations with a mandate and ecosystems, as well as cap- ress does not mean victory—just

to encourage nations to realize the goals sule essays on climate science, a measure of positive change.

of the Paris Agreement on climate change. ecology, politics, economic his- The Ministry She has spent her career strug-
The book follows Mary Murphy, a middle- tory, and global finance. Chap- for the Future gling with “the clot of trends,
ters that give first-person voice Kim Stanley Robinson the Gordian knot of the world,”
aged Irish diplomat who heads the minis- to a photon, a carbon atom, and Orbit, 2020. 576 pp. tugging at this strand and that to
try from the mid-2020s through the 2040s. a herd of caribou put human loosen the snag. The future, she
Her story intertwines with that of Frank

May, who survives a heat wave that kills 20 concerns in perspective. Readers familiar realizes, will be filled with new and differ-

PHOTO: ANDREEA ALEXANDRU/AP PHOTO million people in 2025 but never regains with Robinson’s work will see parallels ent challenges. “We will keep going,” she

his mental stability. May seeks peace by to his Science in the Capital trilogy (1–3), muses to herself, “because we never really

living rough in Zurich and working with which followed fictional scientists and come to the end.” Like Murphy, we must all

refugees, but he is eventually imprisoned administrators at the National Science keep at it. j

for breaking into Murphy’s apartment—an Foundation struggling to translate climate REFERENCES AND NOTES
act driven by anguish over the slow pace of science into action. 1. K. S. Robinson, Forty Signs of Rain (HarperCollins, 2004).
2. K. S. Robinson, Fifty Degrees Below (Spectra, 2005).
The reviewer is an emeritus professor in the Nohad A. Toulan Along with some of Robinson’s favorite 3. K. S. Robinson, Sixty Days and Counting (Spectra, 2007).
School of Urban Studies and Planning, Portland State alternative technologies, such as dirigible
University, Portland, OR, USA. Email: [email protected] airships and hybrid clipper ships powered 10.1126/science.abd9837
by sails and solar energy, The Ministry for

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INSIGHTS | BOOKS

TECHNOLOGY

Moving beyond buzzwords

Rejecting conventional connotations, two books urge readers to rethink innovation

By Dov Greenbaum1,2 and Mark Gerstein2 ous case studies of innovation maintainers that Vinsel and Rus-

in domains ranging from public sell celebrate could be considered

T wo new books—Matt Ridley’s How In- health to communications. innovators. They cite John Day
novation Works and Lee Vinsel and Invention may be the initial Jr., for example, who pioneered
Andrew Russell’s The Innovation De- the idea that computers could be
lusion—reflect on society’s semantic trigger for a new technology, ac- used to manage maintenance and
satiation with “innovation.” Both find knowledges Ridley, but innova- advanced the idea that “every cor-
tion happens as the initial idea

that the term has been reduced to a evolves into marketable goods. To rective maintenance action should

buzzword; however, from this shared starting maximally benefit from science How Innovation Works be balanced by six preventive
point, they take distinctly different directions. and technology, he argues that Matt Ridley maintenance actions.” Readers
we must focus less on revolution- might also take Vinsel and Rus-
In How Innovation Works, Ridley aims to aries and more on the follow-on HarperCollins, 2020. sell to task for not appreciating
upend the notion that innovation emanates 416 pp.

from a lone inventor. Although he finds inno- incremental tinkerers who sub- how innovation can supplant the

vation to be “the most important fact about stantially benefit from the unen- need for maintenance—think cell

the modern world,” he reports that what is cumbered exchange of knowledge. phones versus phone booths.

popularly perceived as “invention” is really an In stark contradiction to Rid- Although they diverge on many

extended innovation process—an evolution- ley’s efforts to bolster the concept issues, both books posit that inno-

ary, as opposed to a revolutionary, process. of innovation and save it from its vation is not only the purview of

Just as DNA recombination often results success, in their book, The Innova- Silicon Valley. Vinsel and Russell,

in more-successful traits than those that tion Delusion, authors Lee Vinsel for example, quote the economist

arise from random mutations, so too, he and Andrew Russell expose soci- The Innovation Robert Gordon, who noted that
argues, do innovations occur when humans ety’s Faustian bargain with it. In Delusion computing technologies “do not
mingle and exchange ideas, whether in cul- their opinion, strategies to boost hold a candle to the technological
tural hotbeds such as today’s Silicon Valley or innovation, such as emphasizing Lee Vinsel and advances between 1870 and 1970,”
in the Renaissance’s wealthy city-states. Rid- STEM education—which, they ar- Andrew L. Russell such as electricity, concrete, steel,
Currency, 2020. 272 pp.

ley maintains, however, that even in these in- gue, often advance “the interests of univer- automobiles, and airplanes. Quoting the ven-

cubators, innovation is a bottom-up, iterative sities and corporations” rather than those of ture capitalist Peter Thiel, Ridley expresses a

process that is often the result of aftermarket students—have led us to a misplaced focus on similar sentiment: “We wanted flying cars;

tinkering by many users rather than the ac- innovation for innovation’s sake. Moreover, instead we got 140 characters.”

tions of the initial inventors. To support his this misguided emphasis ignores what mat- Both books also cite government regula-

assertion, he meticulously documents vari- ters most in a thriving society: maintenance. tion as inhibitory to the innovation process.

Vinsel and Russell note that they are “sick Ridley, for example, uses numerous examples

1Zvi Meitar Institute for Legal Implications of Emerging of hearing about what’s good for Silicon Val- to show how intellectual property (IP) laws
Technologies, Radzyner Law School, Interdisciplinary Center ley, and what the innovating classes think is inhibit innovation. In particular, he notes
Herzliya, Herzliya, Israel. 2Computational Biology good for us.” However, as much as they dis- how expansive regulation impedes innova-
and Bioinformatics, Yale University, New Haven, CT, USA. like the innovation mind-set, many of the tion in areas such as the genetic modifica-
Email: [email protected]

tion of foods by disincentivizing the trial

and error necessary for such technologies to

advance. IP regulations are also limitations

on maintenance, according to Vinsel and

Russell. The “right to repair” is an ongoing

fight in Congress, hampered by restrictive IP

licenses that limit owners’ ability to fix prop-

erty ranging from tractors to cell phones.

The titles of both books under review

herein reveal that even those who aim to

change our understanding of innovation are PHOTO: MPI34/MEDIAPUNCH/IPX/AP PHOTO

themselves unable to fully reject conventional

definitions of the word. Were we consulted,

we would have advised leaving “innovation”

out of each title lest it perpetuate an outdated

connotation. This criticism aside, both books

are valuable in forcing us to look beyond un-

informative buzzwords to appreciate what is

truly valuable to society. j

A bridge collapse in Tempe, Arizona, highlights the importance of investment in infrastructure maintenance. 10.1126/science.abd9805

178 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

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LETTERS

Feral horses in the Australian Alps threaten the environment, forcing policy-makers to weigh humane conservation practices against less costly approaches.

Edited by Jennifer Sills to a new campus 30 km away. During the Hidden ethical costs
same time, author L. Liu graduated, but the of conservation
Retraction ordinary data transfer to successors was
temporarily discontinued. The manuscript We agree with N. Sekar and D. Shillers
The supplementary materials (SM) for was finalized between mid-December 2019 (“Engage with animal welfare in conserva-
and March 2020, during the unprecedented tion,” Policy Forum, 7 August, p. 629) that
our Report “Proton transport enabled by lockdown of the city of Wuhan for coronavi- welfare considerations are an important
rus disease 2019. All authors who prepared part of the myriad values in conserva-
a field-induced metallic state in a semi- the main manuscript and SM data were tion. However, more humane conservation
isolated in different cities and countries, tactics are often costlier. The money and
conductor heterostructure” (1) contained without access to lab computers or database resources spent on humane conservation
resources, which led to miscommunications. practices detract from the resources avail-
mistakes. Fig. S10 was incorrect. The able for other conservation projects. This
We take full responsibility for the acci- hidden ethical cost of humane conservation
image had been previously saved in an dental mistakes in the SM. We stand by our must be considered when proposing new
experimental design, theoretical calculations, approaches to conservation management.
experimental database. The figure should main data, and analysis of low-temperature
proton ceramic fuel cells. However, given Biodiversity conservation is associated
have shown a schematic illustration. This the mistakes in the SM, we have decided to with a variety of values that often vary
retract the Report. All authors except for implicitly between individuals and organiza-
mistake occurred when computer data was B. Zhu, M. Huang, M. Akbar, and J. S. Kim tions (1, 2). These values are rarely noticed
approved this Retraction. until they conflict, such as when invasive-
transferred from one student to another. species culling is proposed. Compassionate
Y. Wu1, L. Liu1, Q. Shi1, C. Chen2, J. Wei3, J. F. Li3, conservationists have responded to this
Fig. S9B also raised questions. The image L. R. Zheng4, H. B. Song1* challenge with humane but more expensive
1Engineering Research Center of Nano-Geo animal management alternatives including
appears to be a copy of figure 8B in a Materials of Ministry of Education, Faculty of fertility control and trapping and rehoming
Materials Science and Chemistry, China University animals (3). Feral horse management in the
2018 paper in the International Journal of Geosciences, Wuhan, 430074, China. 2Huazhong Australian Alps with passive trapping costs
University of Science and Technology, Wuhan, approximately AU$1116 per horse, whereas
of Hydrogen Energy (2). The tests produc- 430074, China. 3College of Chemistry and Chemical aerial culling costs approximately AU$85
Engineering, Xiamen University, Xiamen, 361005, per horse (4). For the same cost, more
ing the data for these two figures were China. 4Institute of High Energy Physics, Chinese culling could be carried out, resulting in a
Academy of Sciences, Beijing, 100049, China. greater net area of biodiversity conserved.
performed during the same period of time. *Corresponding author. Email: [email protected] Alternatively, savings achieved by imple-
menting aerial culling could be spent on
Because of the similarity between the IV-IP REFERENCES AND NOTES

measurements of SN-120 and the Na CoO / 1. Y.Wu, B.Zhu, M. Huang, L. Liu, Q. Shi, M.Akbar, C. Chen,
x2 J.Wei,J. F. Li, L. R.Zheng,J. S. Kim, H. B. Song, Science
369, 184 (2020).
CeO (x = 0.55) measurements, these data
2 2. L. Liu et al., Int.J. Hydrogen Energ. 43, 12739 (2018).

were wrongly saved in the same folder. 10.1126/science.abe7205

Therefore, the final plotted fig. S9B in

Science erroneously contains data from the

PHOTO: © LANGRISH, BOB/ANIMALS ANIMALS figure in the 2018 paper. We repeated the

experiment to replicate the data and found

that the new outputs of two Na CoO /CeO
x2 2

(x < 0.6) cells are above 550 mW cm–2 at

520∞C, consistent with the data in fig. S9.

These mistakes were related to recent

location and personnel changes. Between

June and September 2019, all laboratories

of the Faculty of Materials Science and

Chemistry, including ours, had to move

SCIENCE sciencemag.org 9 OCTOBER 2020 • VOL 370 ISSUE 6513 179

Published by AAAS

INSIGHTS | LETTERS

other conservation projects in the region. Recreational fishing policies recognize the importance of animal welfare regardless of whether fish are sentient.
In addition to promoting biodiversity
conservation, these projects could benefit An effective application of animal welfare Animal welfare science PHOTO: FLORIAN MÖLLERS
the welfare of other animals by protecting aids conservation
threatened native species (5). in conservation is possible—and is perhaps
In their Policy Forum “Engage with ani-
Considerations of what one could have more effective and convincing to stakehold- mal welfare in conservation” (7 August,
done otherwise with a given resource is p. 629), N. Sekar and D. Shiller overlooked
a foundational principle of the effective ers—without invoking or relying on concepts a long history of conservation-related
altruism movement, an evidence-based animal welfare science. The integration
ethical framework (6). Emerging applica- such as consciousness, sentience, or pain (5, of animal welfare science and conserva-
tions of this framework to conservation tion spans at least 60 years (1) and has
include considerations of animal welfare 7). A pragmatic approach to animal welfare been applied to a broad range of wildlife
and offer promising solutions to complex management activities (2) and interdisci-
cases of value conflict (7, 8). that relies on objective and measurable end- plinary research (3–5). Understanding and
incorporating animal welfare science can
Kate E. Lynch1* and Daniel T. Blumstein2 points of animal well-being is more likely benefit conservation efforts.
1Department of Philosophy, The University of
Sydney, Camperdown, NSW 2006, Australia. to gain support among stakeholders and Animal welfare science is not synony-
2Department of Ecology and Evolutionary Biology, mous with opposition to intentional killing
Institute of the Environment and Sustainability, be implemented in practice than a feelings- of wildlife (compassionate conservation)
University of California, Los Angeles, Los Angeles, (6, 7). Rather, animal welfare science uses
CA 90095, USA. based framework that is based on concepts quantitative measurements to assess harm-
*Corresponding author. ful and positive impacts of human activities
Email: [email protected] that are difficult to define and cannot be on animals (8). Traditionally, the harms are
weighed against conservation benefits to
REFERENCES AND NOTES readily measured in many taxa (5, 7). justify (or rule out) a management action.
1. C.Gamborg et al.,Nat.Educ.Knowl. 3, 8 (2012). Approaches such as compassionate con-
2. J.A.Newman et al., Defending Biodiversity: Environmental Robert Arlinghaus1,2*, Ian G. Cowx3, Brian Key4, Ben servation may, perhaps counterintuitively,
Science and Ethics (Cambridge University Press, K. Diggles5, Alexander Schwab6, Steven J. Cooke7, worsen animal welfare outcomes and make
Cambridge, UK, 2017). Anne Berit Skiftesvik8, Howard I. Browman8 biodiversity conservation more difficult (9).
3. A.Wallach et al.,Conserv.Biol. 32,1255 (2018). 1Department of Biology and Ecology of Fishes,
4. N.J.Beeton,C.N.Johnson,Ecol.Manage.Restor.20, Leibniz-Institute of Freshwater Ecology and Inland Sekar and Shiller use prescriptive
57 (2019). Fisheries, Berlin, Germany. 2Division of Integrative advocacy framing that does not represent
5. D.A.Driscoll et al.,Ecol.Manage.Restor.20,63 (2019). Fisheries Management, Faculty of Life Sciences, animal welfare science. Stipulating that
6. W.McAskill,Doing Good Better: How EffectiveAltruism Humboldt-Universität zu Berlin, Berlin, Germany. conservation agencies should avoid factory
Can HelpYou Make a Difference (Penguin Random House, 3University of Hull International Fisheries Institute, farming products does not reflect scientific
2015). Hull HU6 7RX, UK. 4School of Biomedical Sciences, quantification and comparison of harms
7. K. E.Lynch,D.T.Blumstein,TREE 35,857 (2020). University of Queensland, Brisbane, QLD 4072, posed by this and other human activities.
8. B.S.Freeling,S.D.Connell,TREE 35,3 (2020). Australia. 5DigsFish Services, Banksia Beach, QLD Processes such as land clearing (10) may
4507, Australia. 6Eichelmändli Verlag, Hofstetten pose greater animal welfare impacts when
10.1126/science.abe2505 SO, Switzerland. 7Fish Ecology and Conservation all wild sentient species and types of harm
Physiology Laboratory, Department of Biology, (11) are considered.
Pragmatic animal welfare Carleton University, Ottawa, ON K1S 5B6,
Canada. 8Institute of Marine Research, Ecosystem We agree that increased animal welfare
is independent of feelings Acoustics Group, Austevoll Research Station, 5392 focus is warranted in conservation. Progress
Storebø, Norway. will be expedited by wider collaboration
In their Policy Forum “Engage with animal *Corresponding author. with animal welfare scientists. Decades-old
welfare in conservation” (7 August, p. 629), Email: [email protected]
N. Sekar and D. Shiller state that the “over-
whelming evidence that animals think and REFERENCES AND NOTES
feel” is the basis for their call to include
animal welfare in conservation practices. 1. J.D.Rose et al.,Fish Fish.15,97 (2014).
This feelings-based approach is problem- 2. B.Key,Biol.Phil.30,149 (2015).
atic because there is substantial scientific 3. Food andAgriculture Organization of the United Nations
uncertainty about whether taxa such as
fish are sentient and, therefore, able to feel (FAO),“FAO technical guidelines for responsible fisheries
pain and suffer (1, 2). recreational fisheries”(2012).
4. European Inland FisheriesAdvisory Commission (EIFAC),
In recreational fishing, animal welfare “EIFAC code of practice for recreational fisheries”
concepts are embedded in global interna- (FAO, 2008).
tional conservation policies (3, 4) and in 5. R.Arlinghaus et al.,J.Fish Biol.75,2448 (2009).
local welfare actions (5), despite the uncer- 6. J.C.Evans,With Respect for Nature: Living as Part of the
tainty about fish sentience. These activities NaturalWorld (Sunypress,2015).
are motivated by the reality that fish popula- 7. M.S.Dawkins,J.Zool.301,1 (2017).
tions are composed of individuals whose
well-being is important to the conservation COMPETING INTERESTS
of populations and fisheries, regardless of
whether the animal is able to think and feel. This piece reflects the views of the authors and not those
Moreover, many users of fish respect the life, of their organizations or relevant funding sources.
function, and welfare of individual fish and
act accordingly, independent of whether they 10.1126/science.abe3397
think that the animal can feel pain (5, 6).

180 9 OCTOBER 2020 • VOL 370 ISSUE 6513 sciencemag.org SCIENCE

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scientific tradition in this space teaches us lead to innovations that circumvent difficult planet for animals, including efforts
trade-offs. For instance, conservationists to shape the cultural and consumptive
to prioritize objective assessment of harms have already demonstrated the promise of practices of people around the world (11,
contraceptives to address population control 12). When presented with evidence-based
rather than deferring to advocacy. for horses (2). Giving animal welfare the opportunities to improve the quality of
appropriate weight could motivate efforts to animal life, conservation organizations
Jordan O. Hampton1*, Sandra E. Baker2, Ngaio J. reduce the costs of contraceptive programs. must be receptive to altering their own
Beausoleil3, Marc Cattet4,David M. Forsyth5,6, Clive Prioritization drives innovation. practices as well. 
R. McMahon7, Gilbert Proulx8, Bruce Warburton9
1School of Veterinary and Life Sciences, Murdoch Arlinghaus et al. are likely correct that an Nitin Sekar1* and Derek Shiller2
University, Murdoch, WA 6150, Australia. 2Wildlife instrumental approach, which sets aside the 1Wildlife and Habitats Division, WWF-India, New
Conservation Research Unit, Department of issue of suffering, eases the introduction of Delhi, India. 2The Humane League, New York, NY
Zoology, Recanati-Kaplan Centre, University of some safeguards for animal welfare in rec- 10022, USA.
Oxford, OX13 5JL, UK. 3Animal Welfare Science reational fishing. However, experts remain *Corresponding author.
and Bioethics Centre, School of Veterinary divided on the capacity for consciousness Email: [email protected]
Science, Massey University, Palmerston North in fish (3, 4). If fish can suffer, protections
4442, New Zealand. 4RGL Recovery Wildlife based solely on instrumental considerations REFERENCES AND NOTES
Health and Veterinary Services, Saskatoon, SK would be inadequate. Conservation organi- 1. J. O. Hampton et al., Wildl. Res. 44, 97 (2017).
S7H 4A6, Canada. 5Vertebrate Pest Research zations should, wherever practical, establish 2. C. M.V. Nuñez et al., Conserv. Physiol. 5, 1 (2017).
Unit, Department of Primary Industries, Orange, policies that reflect the diversity of evidence 3. V. Braithwaite, Do fish feel pain? (OUP, Oxford, 2010).
NSW 2800, Australia. 6School of Biological, Earth on suffering in fish. The uncertainty about 4. J. D. Rose et al., Fish Fish. 15, 97 (2014).
and Environmental Sciences, University of New what fish can experience—in contrast to 5. International Fund for Animal Welfare, Guiding Principles
South Wales, Sydney, NSW 2052, Australia. 7IMOS the expert consensus about the capacity for (2020); www.ifaw.org/about/guiding-principles.
Animal Satellite Tagging, Sydney Institute of Marine mammals and birds to suffer—highlights 6. Sierra Club Board of Directors,“Policy on trapping of wild-
Science, Mosman, NSW 2088, Australia. 8Alpha how animal welfare institutions in conserva- life”(2012); www.sierraclub.org/sites/www.sierraclub.
Wildlife Research & Management Ltd., Sherwood tion must navigate diverse challenges across org/files/uploads-wysiwig/Trapping-Wildlife.pdf.
Park, AB T8H 1W3, Canada.9Landcare Research, taxa. Formal concern for animal welfare 7. R.J.Julian, Poult. Sci. 77, 1773 (1998).
Lincoln 7640, New Zealand. could not only shape conservation practice 8. M. R. N. Bruijnis et al., Animal 7, 167 (2013).
*Corresponding author. Email: jordan.hampton@ but also influence the direction of funda- 9. J. Poore,T. Nemecek, Science 360, 987 (2018).
murdoch.edu.au mental research on the quality of animal life. 
10. B. Machovina et al., Sci.Total Environ. 536, 419 (2015).
REFERENCES AND NOTES Hampton et al. describe the work done 11. Global Wildlife Conservation, #endthetrade (2020);
by animal welfare scientists in conservation.
1. B.Warburton,J. Hall, New Zealand J.Zool. 22, 39 (1995). Our Policy Forum did not claim that animal https://endthetrade.com/.
2. S. E. Baker et al., BioScience 63, 928 (2013). welfare science in conservation would be 12. R. Fobar,“Shark fin is banned in 12 U.S. states—but it’s
3. D. Fraser, Anim.Welfare 19, 121 (2010). novel but rather that it deserves more atten-
4. B.Warburton, B. Norton, J.Wildl. Manag. 73, 158 (2009). tion and institutional support. The public still on the menu,”National Geographic (2019).
5. A. M. Harvey et al., Animals 10, 148 (2020). looks to conservation organizations for lead-
6. A. D.Wallach et al., Conserv. Biol. 32, 1255 (2018). ership in how to ethically engage with other COMPETING INTERESTS
7. N.J. Beausoleil, Animals 10, 257 (2020). species. As such, institutional safeguards for This piece reflects the views of the authors and not the official
8. C. R. McMahon et al., Wildl. Res. 39, 375 (2012). animal welfare should be at least as much positions of their organizations.
9. A. Callen et al., Biol. Conserv. 241, 108365 (2020). a priority in conservation as in academic
10. H. Finn, N. Stephens, Wildl. Res. 44, 377 (2017). research. The small minority of conservation 10.1126/science.abe5111
11. D. Fraser,A. M. MacRae, Anim.Welfare 20, 581 (2011). organizations that do explicitly recognize
animal welfare concerns [e.g., (5, 6)] have TECHNICAL COMMENT ABSTRACTS
10.1126/science.abe2171 demonstrated that policies promoting ani-
mal welfare in conservation are practicable. Comment on “Female toads engaging in adaptive
Response hybridization prefer high-quality heterospecifics
We agree with Hampton et al. that ani- as mates”
We agree with Lynch and Blumstein mal welfare science should not be biased
by unsubstantiated pre-existing beliefs. Michael J. Braun, Gerald S. Wilkinson, Brian S. Cade
that decision-makers must consider the However, once enough evidence has accu- Chen and Pfennig (Reports, 20 March 2020,
mulated, evidence-driven advocacy can be p. 1377) analyze the fitness consequences
opportunity costs—financial and ethi- crucial for translating science into societal of hybridization in toads but do not account
improvement. The harms from factory for differences in survival among progeny.
cal—of conservation programming. Making farming to billions of domestic animals Apparent fitness effects depend on families
[e.g., (7, 8)], the climate, and biodiversity with anomalously low survival, yet survival
decisions in the face of such trade-offs (9, 10) merit decisive action from con- is crucial to evolutionary fitness. This and
servation organizations. Whereas some other analytical shortcomings demonstrate
will inevitably require value judgments. substitutes for factory farming might have that a conclusion of adaptive mate choice is
negative biodiversity consequences, other not yet justified.
Decision-makers will likely continue to alternatives—such as diets that largely Full text: dx.doi.org/10.1126/science.abd3905
exclude animal products—can offer a clear
conclude that interventions that harm net win for both animal welfare and biodi- Response to Comment on “Female toads engaging
versity (9, 10).   in adaptive hybridization prefer high-quality hetero-
individual animals, such as culling, are specifics as mates”
Conservation organizations frequently
sometimes merited by the benefits and engage in advocacy to build a better Catherine Chen and Karin S. Pfennig
Braun et al. contend that we did not account
necessitated by financial constraints. for survival, but we did. Differential survival
does not alter our conclusions, which were
Even so, explicit consideration of also robust to removing anomalous families.
They ignore the study system’s natural his-
animal welfare could lead to affordable tory justifying our fitness measures, while
failing to account for our behavioral data. We
improvements when ideal alternatives stand by our conclusion that females adap-
tively choose among heterospecific males.
are unworkable. For instance, evidence Full text: dx.doi.org/10.1126/science.abd5373

suggests that aerial culling operations

might entail acceptable levels of duress

for feral horses if done properly (1). For

a marginal increase in cost, conservation

organizations could promote oversight by

independent animal welfare experts to

ensure adherence to best practices during

unavoidable culling operations. 

Focusing too much on the current finan-

cial costs of humane alternatives could cause

the conservation community to discount

the value of prioritizing animal welfare. We

hope that recognition of the moral relevance

of individual animals’ life experiences could

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10.1126/science.abd3905 (2020).

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10.1126/science.abd5373 (2020).

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RESEARCH NEUROSCIENCE

IN SCIENCE JOURNALS Representing the past
and the future
Edited by Michael Funk
Adaptive behavior requires the
DEVELOPMENTAL BIOLOGY ability to analyze experience both
prospectively and retrospectively.
Intersexuality in female moles How can forward-ordered neural
activity facilitate the storage or
F emale moles are intersexual and develop masculinizing ovotestes, a distinctive trait among expression of reverse-ordered
mammals. Real et al. investigated the origin of this trait by sequencing the Iberian mole sequences? Wang et al. used
genome and applying comparative strategies that integrate transcriptomic, epigenetic, and multitetrode recordings from
chromatin interaction data. They identified mole-specific genomic rearrangements that many individual hippocam-
alter the three-dimensional regulatory landscape of the androgen-converting gene CYP17A1 pal CA1 neurons in rats while
and the pro-testicular factor gene FGF9, both of which show distinct expression patterns in mole simultaneously recording field
gonads. The use of transgenic mice confirms the capability of these factors to increase circulating potentials expressing theta
testosterone levels and to induce gonadal masculinization. This study highlights how integrative oscillations. Spatial representa-
approaches can reveal the phenotypic impact of genomic variation. —BAP Science, this issue p. 208 tion in the place cell network
oscillated between forward and
An Iberian mole peeks out of a burrow. Female moles exhibit intersex characteristics that are due to changes in backward sweeps within each
chromosome structure and gene regulation. theta oscillation. Backward replay
was associated with theta peaks,
VACCINES decline over time. In a human did generate influenza-specific whereas forward replay was PHOTO: TONY EVANS/TIMELAPSE LIBRARY LTD./GETTYIMAGES
study of healthy volunteers, cells, most were short-lived and associated with theta troughs.
Immunity after Davis et al. tracked antibody lost within 1 year. The fact that Most cells fell into one category,
the flu shot responses after flu vaccination. a small number did persist over but some corresponding to
They investigated whether the 1 year raises prospects that the deep-layer neurons showed
The seasonal flu shot is cur- vaccine led to the generation longevity of flu vaccines can bimodular responses. Backward
rently recommended each of antibody-secreting plasma be improved and provides key replay was driven by entorhinal
year because the influenza cells in the bone marrow, a information for the development inputs, whereas forward replay
viral strains in circulation are lymphoid organ that supports of universal vaccines against was evoked by CA3 inputs. These
continuously changing and the survival of these cells for influenza. —PNK are important insights into the
because the antibody responses years. Although vaccination underlying basis of coding future
produced by the vaccine Science, this issue p. 237 and past experiences. —PRS

Science, this issue p. 247

QUANTUM GRAVITY

Spacetime, reconstructed

Theories of holographic dual-
ity feature a correspondence
between a gravitational sys-
tem and a strongly interacting
conformal field theory (CFT)
living on the system’s boundary.
Through this correspondence,
the CFT encodes the geometry
of spacetime in the gravitational
system. Van Raamsdonk ana-
lyzed the role of entanglement
in this theoretical framework.
Instead of considering a single
CFT, the author’s starting point
was a collection of CFT “bits” that
are mutually entangled but do
not interact with one another. The
spacetime that these bits col-
lectively encode was then shown
to be arbitrarily close to the one
encoded by the original CFT, sug-
gesting that entanglement plays
a crucial role in the emergence of
spacetime. —JS

Science, this issue p. 198

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PHOTO (LEFT TO RIGHT): NOAA CC BY 2.0; RJ STYLES/ALAMY STOCK PHOTO B AT T E R I E S and demonstrates that reversal IN OTHER JOURNAL S Edited by Caroline Ash
of ecological collapse is possible and Jesse Smith
Engineering when sustained initial efforts lead
phosphorous anodes to positive feedbacks that support An intermediate
ecosystem recovery. —MEH state between clear
A focus of battery research has and cloudy sky greatly
been the development of a range Sci. Adv. 10.1126/sciadv.abc6434 affects the radiative
of lithium, sodium, and potas- (2020). balance of the planet.
sium cathodes, but improving
anode materials is also an PLANT SCIENCE CLOUD PROPERTIES
important goal. Silicon has shown
some promise for replacing Building a safe space Between states
graphite because of its excep- for stem cells
tional capacity, but the dramatic T he greatest obstacle to understanding and projecting
volume change during lithiation- The meristem, the collection of climate warming is uncertainty about how clouds affect
delithiation processes often leads stem cells that builds plants, is Earth’s radiative balance. Clouds can have either cool-
to failure. Jin et al. developed a resistant to viral infection. Wu et ing or warming effects depending on type and location.
composite that is made of black al. now show that WUSCHEL, a However, the sky is not either cloudy or clear; there is also
phosphorous and graphite in its transcription factor that helps an intermediate state with its own radiative properties. Eytan
core and covered with swollen to sustain stem cell production et al. analyzed satellite data about this “cloud twilight zone”
polyaniline. In contrast to previ- in the shoot apical meristem of and found that it has a significant effect on longwave radia-
ous efforts, bonding between the Arabidopsis, also protects that tive forcing. Its impact is equivalent to that of a 75 parts per
carbon and phosphorous allows stem cell domain from viruses. million increase in atmospheric carbon dioxide, which is nearly
for a high charging rate without WUSCHEL inhibited viral protein equivalent to that caused by anthropogenic emissions for the
sacrifices in capacity and cycling synthesis by repressing meth- past 60 years. —HJS Nat. Geosci. 13, 669 (2020).
stability. —MSL yltransferases that regulate
ribosomal RNA processing and
Science, this issue p. 192 ribosome stability. —PJH

ECOSYSTEM RECOVERY Science, this issue p. 227

Successful restoration TINNITUS
of seagrass beds
Relief from ringing
Since 1999, broadcasting more
than 70 million seeds of the There is no universally effective
seagrass Zostera marina into treatment for tinnitus, which is
coastal lagoons in Virginia has led phantom perceived sound or
to the reestablishment of more ringing in the ears. Conlon et al.
than 3600 hectares of previously studied the effects of bimodal
lost seagrass beds. Orth et al. neuromodulation using a device
found that seagrass recovery led that delivers electrical stimula-
to rapid increases in the produc- tion to the tongue and sound to
tion and diversity of animals, the ears. Participants reported
increases in carbon and nitrogen reduced symptom severity at the
sequestration, decreases in end of 12 weeks of treatment,
turbidity, and increases in previ- which persisted for 12 months.
ously depleted bay scallops. This Results support the safety and
is one of the larger success potential utility of bimodal neuro-
stories of ecosystem restoration modulation for tinnitus. —CC
Sci. Transl. Med. 12, eabb2830 (2020).

Eel grass restoration off the coast of eastern Virginia has enabled repopulation of NEURODEVELOPMENT how variation in speech process-
important species such as the bay scallop, pictured here. ing affects the ability to read
Speech processing for children with typical reading
and reading skills ability and those with dyslexia.
A child introduced to a spoken
People differ in their ability to word in a noisy classroom setting
parse language in noisy environ- may find that word difficult to
ments. Especially challenging are recognize in the written context.
settings in which the talking face Reciprocally, reduced reading
is not visible and background experience would give a child
noise consists of other people a more limited mental lexicon
talking. Destoky et al. investigated

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RESEARCH | IN OTHER JOURNALS

SYMBIOSIS

Hyphal toll roads through the soil

F ilamentous fungi such as Aspergillus nidulans grow
by hyphal branching and extension in a multicellular
network. These networks make “highways” through
the soil for motile bacteria such as Bacillus
subtilis, but whether this relationship is exploit-
ative or mutualist is not well understood. Abeysinghe
et al. found that when B. subtilis grows together with
A. nidulans, the bacteria’s thiamine biosynthesis operon
is induced. However, the fungal equivalent is repressed,
and the authors presume that this is to save metabolic
costs. If the fungal operon is experimentally ablated, the
resulting growth defect of the fungus can be rescued by
intact B. subtilis. It appears that bacteria using the fungal
highway to reach new foraging grounds pay for the ride by
delivering thiamine to the hyphal tips.
—CA Life Sci. Alliance 3, e202000878 (2020).

Mycelium of cultured Aspergillus nidulans. In the soil, this fungus
allows bacteria to travel along its hyphae in return for delivering
vitamins to help it grow.

to draw upon when trying to displayed activation of inflamma- deficient in Grip1 exhibited learn- with just two single-point conven- PHOTO: GEOFF TOMPKINSON/SCIENCE SOURCE
interpret what the teacher says in somes, autophagy, and metabolic ing and memory deficits. These tional DFT calculations. —YS
that noisy classroom. The authors dysfunction. Thus, cardiac findings indicate an essential
suggest that small alterations in a macrophages play an important role for GRIP1 in synaptic plas- J. Phys. Chem. Lett. 11, 7882 (2020).
variety of processing abilities, as role in maintaining heart health ticity and cognitive functions.
reflected by cortical representa- by providing a way for cardiomyo- —PRS ECONOMIC INEQUALITY
tion of speech in noise, determine cytes to maintain organelle and
reading abilities and differentiate metabolic homeostasis under Proc. Natl. Acad. Sci. U.S.A. 10.1073/ Minimum wage policy and
those with dyslexia from typical incessant stress. —SMH pnas.2014827117 (2020). the racial earnings gap
readers. —PJH
Cell 10.1016/j.cell.2020.08.031 QUANTUM CHEMISTRY The earnings gap between white
PLOS Biol. 18, e3000840 (2020). (2020). and Black workers in the United
UV-vis spectra from States fell substantially only
BIOMEDICINE NEUROSCIENCE time-independent DFT once over the past 70 years.
Derenoncourt and Montialoux
Eating the heart healthy Getting a GRIP on AMPARs Theoretical chemistry methods show how this change was
used to simulate electronic driven in large part by the
The heart is composed of cardio- Regulation of synaptic AMPA absorption properties, such 1967 extension of the federal
myocytes that beat all day every receptors (AMPARs) is a key as time-dependent density minimum wage to sectors that
day with very little cellular turn- process implicated in synaptic functional theory (TD-DFT), employed about 20% of the
over. How do these cells manage plasticity. Glutamate receptor are usually applicable only to total U.S. workforce but nearly a
to keep themselves healthy in interacting protein 1 (GRIP1) is a small- or medium-size systems third of Black workers, includ-
the face of such constant stress? scaffolding protein that interacts because of their unfavorable ing agriculture, hotels, and
Nicolás-Ávila et al. found that directly with several members scaling behavior. Chan and Hirao schools. This policy extension
macrophages residing in the of the AMPAR family. GRIP1 propose an orbital energy-based can explain more than 20% of
myocardium actively contribute regulates the surface expres- approximation scheme aimed to the decline in the racial earnings
to cardiomyocyte maintenance. sion and synaptic stabilization accurately simulate ultraviolet- gap between 1965 and 1980
Cardiomyocytes expel damaged of AMPARs, but its role in the visible (UV-vis) spectra using and did not have large adverse
organelles, including mitochon- expression of long-term poten- a lower-cost conventional employment effects on either
dria, in packages that resemble tiation (LTP) is unknown. Tan (time-independent) version of Black or white workers. The
structures in the brain called et al. investigated the function DFT. Their proposed approach gap between the average wage
exophers. These membranous of GRIP1 in LTP and its impact demonstrates reliable perfor- in the treated industries and
particles are then consumed by on learning and memory. GRIP1 mance across an extensive range the rest of the economy fell, as
macrophages using phagocyto- was recruited into synapses with of examples, from small organic did the gap between Black and
sis. When cardiac macrophages AMPARs. The GRIP1-AMPAR molecules to large metal-organic white workers within the treated
were depleted in mice, the myo- interaction was enhanced during frameworks with electrochromic industries. —BW
cardium became compromised. LTP. Loss of GRIP1 blocked the properties. Its accuracy is com-
Cardiomyocytes accumulated activity-induced accumulation parable to TD-DFT but is achieved Q. J. Econ. 10.1093/qje/
defective mitochondria and of synaptic AMPARs and mice qjaa031 (2020).

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ALSO IN SCIENCE JOURNALS
Edited by Michael Funk

BIOTECHNOLOGY CORONAVIRUS contribute to the first half of the includes the regulatory domain,
HIV life cycle. —SMH depending on the relative
Evolution of bioengineered Questions about bats arrangement of the kinase and
blood vessels and viruses Science, this issue p. 187 regulatory domains, the kinase
domain is stabilized in either
Biotechnology approaches Bats have been attributed as the VIRAL INFECTIONS the active state or one of the
to repair and replace arteries source of several recent diseases inhibited states. Understanding
have been under development that have made the jump from ACHOO!-trophils? the conformational dynamics
for more than a century. Early animal hosts to humans. It has of kinases can be leveraged to
synthetic approaches used rub- been suggested that bats have Why some individuals come design selective drugs. —VV
ber-based replacements, which an attenuated inflammatory down with a cold in any given
then evolved into the use of poly- immune response that allows year, whereas others are spared, Science, this issue p. 189
mer fabrics and, more recently, them to tolerate more viruses is poorly understood. Habibi et
into biological approaches that than other mammals, making al. exposed volunteers to respira- M E TA L LU R GY
permit the growth of blood ves- them a hotbed for zoonotic tory syncytial virus (RSV), one
sels in the laboratory. Niklason virus evolution. In a Perspective, of the pathogens responsible Disentangling fatigue
and Lawson review the scientific Streicker and Gilbert discuss for the common cold, and then
and technological advances what is known about bats as followed them over the ensuing Metal fatigues when repeatedly
that allow the regeneration of a source of zoonotic viruses, 2 weeks (see the Perspective by loaded, ultimately failing when
a patient’s own blood vessels. raising questions about the Mirchandani and Walmsley). The cracks form and propagate
The authors discuss how blood influence of species diversity on main factor distinguishing the through the material. Lavenstein
vessel cells, when combined such generalizations. Moreover, infected from the noninfected et al. studied the origins of this
with suitable substrates for zoonotic spillover is a poorly was that the former showed process in nickel. Using high-
tissue growth under conditions understood and complicated signs of airway neutrophil resolution observations, they
that mimic human physiology, process that is influenced by activation before exposure to tracked how dislocations evolved
can produce functional bioengi- anthropogenic behaviors such RSV. Conversely, protected into microstructural features
neered arteries. These biological as culling, the wildlife trade, individuals showed enhanced called persistent slip bands that
approaches pave the way to and consumption. The role of interleukin-17 signaling soon preceded crack formation. The
advancing how vascular disease bats in zoonoses needs much after virus inoculation. Similarly, evolution of tangles of disloca-
is managed and treated in the more investigation, including mice pretreated with a neutro- tions to a more regularly spaced
future. —PNK long-term monitoring, before phil chemoattractant were more pattern form the basis for the
solutions can be found. —GKA susceptible to RSV infection persistent slip bands and provide
Science, this issue p. 185 and CD8+ T cell–driven disease. a road map for understanding
Science, this issue p. 172 Neutrophil proteases, which can fatigue cracking in metals. —BG
ELECTROCHEMISTRY modulate cytokine activity, may
HIV explain the disparity and could Science, this issue p. 190
Electrolysis feels the heat provide therapeutic targets for
HIV-1 replication and RSV and other respiratory infec- NEUROSCIENCE
Electricity infrastructure integration in vitro tions. —STS
powered by sunlight and wind Interface targeting skirts
requires flexible storage capacity To infect a host cell, HIV-1 must Science, this issue p. 188; excitotoxicity
to compensate for the intermit- reverse transcribe its single- see also p. 166
tency of these sources. In this stranded RNA genome into a Nearly all attempts to use
context, Hauch et al. review double-stranded DNA copy and STRUCTURAL BIOLOGY traditional N-methyl-D-aspartate
progress in solid oxide electro- integrate that copy into a host receptor (NMDAR) antagonists
lyzer technology to split water chromosome. Reverse transcrip- A moving target to treat neurodegenerative
and/or carbon dioxide into tion and integration have been diseases have failed. This is
chemical fuels. These devices, characterized separately but Abl kinase is an important signal- because NMDARs are not only
which rely on oxide conduction have not been reconstituted ing protein that is dysregulated promoters of neuronal death but
between cathode and anode, use together outside of the cell. in leukemia and other cancers also have essential physiologi-
nonprecious metals as cata- Christensen et al. now report and is the target of inhibitors cal roles in synaptic plasticity
lysts and operate above 600°C, that viral core particles can such as imatinib. Like other and cognitive functions such
thereby benefiting from thermo- complete full reverse transcrip- kinases, Abl kinase is dynamic, as learning and memory. Yan
dynamic and kinetic efficiencies. tion and integration in a cell-free and regulating conformational et al. explored the structural
The authors highlight recent system. The external capsid shell dynamics is key to regulating basis of NMDAR coupling to
optimizations of cell compo- of the core is required for effi- activity. Xie et al. used nuclear neuronal cell death (see the
nents as well as systems-level cient reverse transcription, and magnetic resonance to show Perspective by Jones). The
architecture. —JSY the replicating DNA can loop out that the Abl kinase domain inter- death-promoting activity, but
of capsid openings. Integration converts between one active and not the essential physiological
Science, this issue p. 186 requires cell extract, and this two inactive states. Imatinib sta- function, was mediated by the
cell-free system should be useful bilizes an inactive conformation, physical interaction of NMDARs
for analyzing how host factors and several resistance muta- with TRPM4, a calcium-imper-
tions act by destabilizing this meable ion channel activated by
conformation. In a construct that

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RESEARCH

intracellular calcium, depo- ORGANIC CHEMISTRY the next generation of antiviral in cryo-EM structures. Far fewer
larization, and temperature. A therapies. Bruchez et al. used a particles per unit resolution are
subsequent structure-based A potential method to transposon-mediated gene- required, which greatly acceler-
computational drug screen led tune reactivity activation screen to search for ates structure determination,
to the discovery of neuroprotec- previously unreported host especially at high resolution.
tive small molecules that block In organic chemistry, reaction restriction factors for Ebola virus —MAF
the NMDAR-TRPM4 interaction rates are often sensitive to sub- (see the Perspective by Wells
interface but spare the critical stituents that either donate or and Coyne). The authors found Science, this issue p. 223;
healthy NMDAR function. —PRS withdraw electron density from a that a transcription factor, major see also p. 171
reactive carbon center. Heo et al. histocompatibility complex class
Science, this issue p. 191; now report that when reactants II transactivator (CIITA), induces CANCER IMMUNOLOGY
see also p. 168 are tethered to an electrode, the resistance in human cell lines
polarization effect of an applied by directing the expression of TAMs reprogram tumor
CORONAVIRUS potential can exert an analogous the p41 isoform of the invariant metabolism
influence, essentially acting chain (CD74). CD74 p41 then
Flexible spikes as a tunable functional group. disrupts cathepsin-mediated Macrophages in the tumor
The authors demonstrate rate Ebola glycoprotein processing, microenvironment (called
The severe acute respiratory modulations in ester hydrolysis which prevents viral fusion and tumor-associated macro-
syndrome coronavirus 2 (SARS- and arene cross-coupling, as entry. CD74 p41 can also stymie phages or TAMs) often support
CoV-2) spike protein enables viral well as a two-step acid-to-amide the endosomal entry of corona- tumor growth and metastatic
entry into host cells by binding conversion that benefits from viruses, including severe acute progression. Gomez et al.
to the angiotensin-converting inversion of the polarization mid- respiratory syndrome coronavi- found that secretion of the
enzyme 2 (ACE2) receptor and way through the reaction. —JSY rus 2 (SARS-CoV-2). This work cytokine transforming growth
is a major target for neutralizing should inform future treatments factor–beta (TGF-b) from anti-
antibodies. About 20 to 40 spikes Science, this issue p. 214 against cathepsin-dependent inflammatory TAMs suppressed
decorate the surface of virions. viruses such as filoviruses and the abundance of succinate
Turoňová et al. now show that NOVEL COMMUNITIES coronaviruses. Additionally, the dehydrogenase in breast
the spike is flexibly connected screening strategy used may cancer cells. The loss of this
to the viral surface by three Change begets change serve as a blueprint for uncov- metabolic enzyme promoted
hinges that are well protected by ering resistance mechanisms glycolysis, thereby enhancing
glycosylation sites. The flexibility In the Anthropocene, humans against other dangerous patho- tumor growth, angiogenesis, and
imparted by these hinges may are altering ecosystems, causing gens. —STS immunosuppression. Depleting
explain how multiple spikes act extinctions, and reassorting anti-inflammatory TAMs or
in concert to engage onto the flat species distributions. As we Science, this issue p. 241 blocking TGF-b suppressed
surface of a host cell. —SMH facilitate these changes, we see also p. 167 these effects in mice. —LKF
are creating new collections
Science, this issue p. 203 of species. Such “novel com- ELECTRON MICROSCOPY Sci. Signal. 13, eaax4585 (2020).
munities” are not specific to
SUPERCONDUCTIVITY our epoch, and the patterns of Going for the gold VIRAL IMMUNOLOGY
diversity and extinction associ-
Alternative route to a 2D ated with past events can shed Single-particle cryogenic elec- Revenge against rotavirus
superconductor light on the implications of tron microscopy (cryo-EM) has
current community restructur- become a go-to technique for Rotavirus (RV) is an enteric
Single layers of transition metal ing. Pandolfi et al. looked at structural biologists. Although infection that can cause severe
dichalcogenides exhibit exotic marine plankton communities data-processing and reconstruc- morbidity and contributes to
properties, including super- over the past ~66 million years tion methods have improved, childhood mortality in resource-
conductivity. The usual route and found that the emergence innovations in sample prepara- poor countries where the existing
to obtaining such samples is to of novel communities leads tion and data collection are vaccine is of moderate efficacy. A
exfoliate a three-dimensional to further novelty and extinc- essential to reliably achieve previous study showed that the
(3D) crystal. Devarakonda et al. tion (see the Perspective by high-resolution reconstructions cytokines interleukin-18 (IL-18)
instead grew a superlattice com- Dornelas and Madin). Although while also reducing the amount and IL-22 work together to pre-
prising alternating layers of the community change is a natural of time required per structure. vent or treat RV infection. Zhang
transition metal dichalcogenide biological response to environ- Naydenova et al. tackled the et al. now show that IL-22 drives
hexagonal NbS2 and the material mental change, the current rate issue of electron beam–induced intestinal epithelial cell (IEC) pro-
Ba3NbS5 (see the Perspective of change could lead to impend- particle movement, a major liferation and migration toward
by Schoop). The inert Ba3NbS5 ing and rapid impacts. —SNV source of information loss, by villus tips, resulting in extrusion
layers serve to dissociate the designing a gold sample sup- of differentiated IECs, which
superconducting NbS2 layers Science, this issue p. 220; port that prevents buckling are sites of RV replication. IL-18
from one another, resulting in see also p. 164 of the extremely thin layer of induces cell death of infected
2D superconductivity with high ice in which the particles are IECs, and together these mecha-
carrier mobility. The combina- CORONAVIRUS suspended (see Perspective nisms accelerate clearance of RV
tion of high mobility and reduced by Rapp and Carragher). The from the intestine. These findings
dimensionality may give rise to The CIITAdel keeps negligible particle displacement suggest that these cytokines may
exotic quantum phases. —JS viruses at bay permits extrapolation to “zero support the clearance of other
exposure” structure factors, enteric viral infections. —CNF
Science, this issue p. 231 A better understanding of cel- revealing features typically lost
see also p. 170 lular mechanisms involved in Sci. Immunol. 5, eabd2876 (2020).
viral resistance is needed for

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