1458 17 DECEMBER 2021 • VOL 374 ISSUE 6574 science.org SCIENCE
al. used an approach com-
monly used to predict spatially
explicit regions of physiological
challenge in animal species to
create a hazard landscape for
the border crossing between
the United States and Mexico.
Their predictions of high risk,
particularly due to dehydra-
tion, coincided with regions of
high migrant mortality. Such
detailed predictions may help
to prevent these tragedies.
—SNV
Science, abh1924, this issue p. 1496CELL BIOLOGY
Elusive inhibin B
co-receptor identified
Inhibin B secreted by the
ovarian follicle in response to
follicle-stimulating hormone
(FSH) plays an essential role inNEUROSCIENCE
Locomotion-related
signals in the brain
To calculate where we are in
space, continuous knowledge
of one’s speed is necessary.
How does the brain know
how fast the body is traveling
during locomotion? Using in
vivo calcium imaging, electro-
physiology, optogenetics, cell
tracing, and histology, Farrell
et al. identified neurons in
the rodent supramammillary
nucleus of the hypothalamus
that encode future locomo-
tor speed and potently drive
locomotion when stimulated.
Because these locomotor neu-
rons have extensive axons in
brain areas that support spatial
navigation, this cell type distrib-
utes this information selectively
to areas that require knowledge
of speed. This nucleus is func-
tionally positioned between
input from a higher-order cogni-
tive center and the downstream
midbrain where locomotor
nuclei reside. —PRS
Science, abh4272, this issue p. 1492MAGNETISM
Peeking into magnetic
textures
Topological spin textures hold
promise as robust carriers of
information and have been
observed in bulk materials with
a specific crystal structure. One
of these materials, manganese
germanide (MnGe), exhibits
unusual textures in bulk form.
Repicky et al. used spin-
polarized scanning tunneling
microscopy to study surface
magnetism in thin films ofMnGe. Achieving high spatial
resolution, the researchers
observed stripe-like features
consistent with a helical state.
In regions where the film was
slightly curved due to strain,
the intersection of domain
walls led to characteristic
closed patterns that could be
manipulated with current/volt-
age pulses. —JS
Science, abd9225, this issue p. 1484PHYSIOLOGICAL STRESS
Dangerous terrain
As climate change leads to
regions of the world becom-
ing increasingly uninhabitable,
unregulated human migration
is likely to increase. Migrants
often traverse dangerous ter-
rain, and the environmental
conditions they encounter can
be deadly. Campbell-Staton etEdited byMichael FunkIN SCIENCE JOURNALS
RESEARCH
RADIATIVE COOLINGA passive turnoff
P
assive radiative cooling technology uses the infrared atmospheric window to allow outer space to be a cold sink
for heat. However, this effect is one that is only helpful for energy savings in the warmer months. Wang et al. and
Tang et al.used the metal-insulator transition in tungsten-doped vanadium dioxide to create window glass and
a rooftop coating that circumvent this problem by turning off the radiative cooling at lower temperatures. Because
the transition is simply temperature dependent, this effect also happens passively. Model simulations suggest that
these materials would lead to energy savings year-round across most of the climate zones in the United States. —BG
Science, abg0291, abf7136, this issue p. 1501, p. 1504New materials for passive radiative cooling of homes and buildings can be deactivated at cooler temperatures by a temperature-dependent transition.CREDITS: (THIS PAGE PHOTO KALULU/ISTOCK.COM; (OPPOSITE PAGE LEFT TO RIGHT GOOGLE QUANTUM AI; WALLIS ET AL., DEV. CELL56, P3192 (2021/CC BY