CREDITS: (PHOTO IGOR ALECSANDER/GETTY IMAGES; (GRAPHIC C. BICKEL/
SCIENCE
256
CONTENTS
21 JANUARY 2022
VOLUME 375
ISSUE 6578260
INSIGHTS
PERSPECTIVES
260 Kids attend to saliva sharing
to infer social relationships
Saliva sharing suggests “thick,”
intimate bonds By C. Fawcett
REPORT p. 311FEATURES
256 Window of opportunity
When surgery to treat neurological
conditions lets researchers peer
into the brain, ethical questions abound
By K. Servick
PODCASTNEWS
IN BRIEF
248 News at a glanceIN DEPTH
250 A controversial train heads for
the Maya forest
Critics fear Mexico’s presidential megaproject
could threaten ecology, archaeology
By R. Pérez Ortega and I. Gutiérrez Jaber252 EU grants restrict U.K. and Swiss
research
Rules on first grants from Horizon Europe
highlight ongoing diplomatic disputes
By G. Guglielmi253 Studies reveal dangers of
SARS-CoV-2 infection in pregnancy
Vaccination helps prevent stillbirths,
critical care By M. Wadman254 Mars rover detects carbon
signature that hints at past life source
Dramatically “light” carbon could also be
explained by atmospheric reactions or
cosmic dust B y P. Vo o s e n255 China falls silent about its
recruitment efforts
Information about “talent programs” that
drew U.S. scrutiny is no longer available
By D. Normile262 One cell, many fates
A synthetic gene circuit enables
programming of many stable states in
mammalian cells By C. Kunze and A. S. Khalil
RESEARCH ARTICLE p. 284263 Many-particle electron states
in graphene
Scanning tunneling microscopy probes
ground state competition in a magnetic field
By M. Morgenstern and M. Goerbig
REPORT p. 321264 Epstein-Barr virus and multiple
sclerosis
Infection with Epstein-Barr virus is the trigger
for the development of multiple sclerosis
By W. H. Robinson and L. Steinman
REPORT p. 296266 The global nitrogen-phosphorus
imbalance
The imbalance has grave consequences for
natural ecosystems and global food security
By J. Peñuelas and J. Sardans267 Nervous system consequences
of COVID-
Neurological symptoms highlight the need
to understand pathophysiologic mechanisms
By S. Spudich and A. NathPOLICY FORUM
270 How privacy’s past may shape
its future
An account of privacy’s evolutionary roots
may hold lessons for policies in the digital age
By A. Acquisti et al.SCIENCE science.org 21 JANUARY 2022 • VOL 375 ISSUE 6578 243