syndrome–coronavirus 2
(SARS-CoV-2), which causes
coronavirus disease 2019
(COVID-19)? The rich data from
the Open COVID-19 Data Working
Group include the dates when
people first reported symptoms,
not just a positive test date. Using
these data and real-time travel
data from the internet services
company Baidu, Kraemer et al.
found that mobility statistics
offered a precise record of the
spread of SARS-CoV-2 among
the cities of China at the start of- The frequency of introduc-
tions from Wuhan were predictive
of the size of the epidemic
sparked in other provinces.
However, once the virus had
escaped Wuhan, strict local
control measures such as social
isolation and hygiene, rather than
Mouse models of two other
coronaviruses demonstrated
that early treatment reduced viral
replication and damage to the
lungs. Mechanistically, this drug
is incorporated into the viral RNA,
inducing mutations and eventu-
ally leading to error catastrophe
in the virus. —LP
Sci. Transl. Med. 12 , eabb5883 (2020).APPLIED ECOLOGY
New roads threaten
Asian tigers
The development of road
networks in Asia, specifically
China’s Belt and Road Initiative, is
expanding at an unprecedented
rate and eating up previously
protected areas meant for endan-
gered tigers. Carter et al. foundthat ~43% of the area where
tiger breeding occurs and ~57%
of tiger conservation landscapes
have fallen prey to proliferating
road networks. According to
this analysis, more than 20% of
tiger and prey abundance could
decrease by the year 2050.
Sustainable road development is
thus an urgent priority to prevent
further decreases in endangered
tiger species. —SN
Sci. Adv. 10.1126/sciadv.aaz9619
(2020).CORONAVIRUS
Tracing infection from
mobility data
What sort of measures are
required to contain the spread
of severe acute respiratoryCORONAVIRUS
Antiviral error
catastrophe
The development of broad-
spectrum antiviral drugs is
desirable, particularly in the
context of emerging zoonotic
infections for which specific
interventions do not yet exist.
Sheahan et al. tested the poten-
tial of a ribonucleoside analog,
b-D-N^4 -hydroxycytidine, which
was previously shown to be
active against RNA viruses such
as influenza and Ebola virus, to
inhibit coronaviruses. This drug
was effective in cell lines and
primary human airway epithe-
lial cultures against multiple
coronaviruses, including severe
acute respiratory syndrome–
coronavirus 2 (SARS-CoV-2). IMAGE: PENG
ET AL.484 1 MAY 2020 • VOL 368 ISSUE 6490 sciencemag.org SCIENCE
Edited by Michael FunkIN SCIENCE JOURNALS
RESEARCHNANOPHOTONICSNanowire-based THz detection
T
erahertz (THz) radiation is an interesting region of the
electromagnetic spectrum lying between microwaves and
infrared. Non-ionizing and transparent to most fabrics, it is
finding application in security screening and imaging but
is also being developed for communication and chemical
sensing. To date, most THz detectors have focused just on signalintensity, an effort that discards half the signal in terms of the full
optical state, including polarization. Peng et al. developed a THz
detector based on crossed nanowires (arranged in a hash struc-
ture) that is capable of resolving the full state of the THz light. The
approach provides a nanophotonic platform for the further devel-
opment of THz-based technologies. —ISO Science, this issue p. 510A detector made from crossed nanowires resolves the full polarization state of terahertz radiation.