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764 24 AUGUST 2018 • VOL 361 ISSUE 6404 sciencemag.org SCIENCE
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BLOOD
A turbulent way to make platelets Donations from volunteers are
the only source of blood for trans-
fusions. But blood components
such as platelets have a shelf
life of only 5 days, and alterna-
tive sources of platelets are in
demand. By visualizing fluores-
cently tagged megakaryocytes
(precursor cells of platelets) in
transgenic mice, Ito et al. dem-
onstrated that highly turbulent
blood flow is a determining factor
of platelet production from mega-
karyocytes. Turbulence triggered
the production of thrombopoietic
factors from megakaryocytes,
which, along with shear stress,
stimulated platelet release. By
using a turbulence-controllable
bioreactor, functionally viable
platelets could be generated
from megakaryocytes derived
from human-induced pluripotent
stem cells at a quantity that
satisfies clinical-scale demand,
suggesting the possibility of de
novo platelet production as an
alternative to acquiring platelets
through blood donations. —MY
Cell 174, 636 (2018).
INFECTIOUS DISEASE
Zika in the testes: A Trojan horseZika virus (ZIKV) is a mosquito-
borne flavivirus that can also be
sexually transmitted. Although
people infected with ZIKV are
often asymptomatic, there is
an association between ZIKV
infection in pregnant women and
severe birth defects in their chil-
dren. Matusali et al. showed that
ZIKV can replicate for several
days in testicular tissue explants.
ZIKV infects testicular somatic
cells, germ cells, and spermato-
zoa, and its presence has been
detected in semen samples from
ZIKV-infected patients. Despite
Edited by Sacha Vignieri
and Jesse SmithIN OTHER JOURNALS
because of the protein’s wide-
spread role in multiple tissues
and organs. Cuchet-Lourenço et
al. studied patients with inherited
immunodeficiency of unknown
cause (see the Perspective by
Pasparakis and Kelliher). They
identified inactivating mutations
in the RIPK1 gene in four individu-
als. Unlike what has been seen
in mice, the deleterious effects
of RIPK1 loss in humans were
confined to the immune system, a
finding with potential therapeutic
implications. —PAK
Science, this issue p. 810;
see also p. 756
SOCIAL ROBOTICS
Robots help autistic kids interact with adultsChildren with autism spectrum
disorder (ASD) often struggle
with social behaviors such as
recognizing emotional responses
in others and understanding
gaze direction. Scassellati et al.
put a fully autonomous, adap-
tive robot in the homes of 12
children with ASD for 1 month to
help improve the children’s social
skills. The robot and a caregiver
engaged with each child for 30
minutes every day, playing games
that involved activities such as
emotional storytelling and taking
another’s perspective. The robot
autonomously adapted task diffi-
culty to each child’s performance
and modeled appropriate gaze
directions. The children showed
improvements in attention skills
and, crucially, demonstrated the
improvements while interacting
with adults even when the robot
was not present. —RLK
Sci. Robot. 3, eaat7544 (2018).
GAS GIANT PLANETS
Moons drive structure in Jupiter’s auroraeLike Earth, Jupiter has aurorae
generated by energetic particles
hitting its atmosphere. Those
incoming particles can come
from Jupiter’s moons Io and
Ganymede. Mura et al. used
infrared observations from the
Juno spacecraft to image the
moon-generated aurorae. The
pattern induced by Io showed
an alternating series of spots,
reminiscent of vortices, and
sometimes split into two arcs.
Aurorae related to Ganymede
could also show a double struc-
ture. Although the cause of these
unexpected features remains
unknown, they may provide a
way to examine how the moons
produce energetic particles or
how the particles propagate to
Jupiter. —KTS
Science, this issue p. 774
PROTEOMICS
The blood proteome in diseaseUnderstanding the function of
human blood serum proteins
in disease has been limited by
difficulties in monitoring their
production, accumulation, and
distribution. Emilsson et al. inves-
tigated human serum proteins of
more than 5000 Icelanders over
the age of 65. The composition of
blood serum includes a complex
regulatory network of proteins
that are globally coordinated
across most or all tissues. The
authors identified modules and
functional groups associated with
disease and health outcomes and
were able to link genetic variants
to complex diseases. —LMZ
Science, this issue p. 769
GRAPHENE
An electronic wedding cakeIn nanostructures such as quan-
tum dots, spatial confinement
forces electrons to assume dis-
crete energy levels. Quantization
can also occur in an external
magnetic field, where electrons’
energies group into so-called
Landau levels (LLs). Gutiérrez et
al. explored the interplay between
these two mechanisms and elec-
tronic interactions in a circulator
resonator made of graphene. As
an external magnetic field was
increased, the electron quantum
states transformed from atomic-
like states to LL-like states.
Electronic interactions caused a
characteristic wedding cake–like
shape of electronic density at
high fields. —JS
Science, this issue p. 789
Artist’s rendering of the Gaia spacecraft
STELLAR EVOLUTION
A population of
merged white dwarfs
White dwarfs are the hot
exposed cores left over when
a dying low-mass star throws
off its outer layers. The Gaia
spacecraft recently provided
accurate distances to more than a
hundred times as many white dwarfs
than were previously available, allow-
ing detailed studies of the population.
Kilic et al. investigated the mass and
composition of these white dwarfs and
reproduced them with stellar evolu-
tion models. They show that about
15% of the white dwarfs have higher-
than-expected masses. This is a sign
that they formed from mergers, either
between two parent stars or two white
dwarfs. —KTS
Mon. Not. R. Astron. Soc. Lett. 479, L113 (2018).
RESEARCH | IN SCIENCE JOURNALS
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24 AUGUST 2018 • VOL 361 ISSUE 6404 765SCIENCE sciencemag.org
PH
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HIR
OF
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induction of antiviral genes, no
overt inflammatory response was
observed, and testicular morphol-
ogy and hormone production
remained unaffected. Apparently,
ZIKV remains quiescent in the
testes. This phenomenon may
explain asymptomatic disease
transmission and offer a possible
target for antiviral drugs. —MY
J. Clin. Invest. 10.1172/
JCI121735 (2018).
CELL BIOLOGY
Raman spectroscopic transcriptome Raman spectroscopy records
the vibrational Raman spectra
of biomolecules, allowing the
determination of chemical spe-
cies in target samples. Although
nondisruptive and label-free, its
application in cell imaging is lim-
ited because of the complexity of
cellular compositions. Kobayashi-
Kirschvink et al. described
computational approaches to
extract key information from cel-
lular Raman spectra in yeast and
bacteria. Dimension-reduction
methods enabled a direct predic-
tion of transcriptomes from
cellular Raman spectra. A better
correlation between the Raman
spectra and noncoding tran-
scriptome revealed a more linear
correspondence of noncoding
RNAs with cellular constituent
biomolecules. Although it remains
unknown if the linkage can be
demonstrated at the single-cell
level, spectroscopic live-cell
omics provides new possibili-
ties to monitor different cellular
states. —SYM
Cell Syst. 7, 104 (2018).
EDUCATION
Teaching and research in synergyThe unspoken belief in gradu-
ate student training is that time
spent teaching, or learning about
teaching, will decrease research
productivity. Shortlidge and
Eddy tested this trade-off using
a national sample of life science
Ph.D. students. Results show
that graduate students who
participated in evidence-based
teaching (EBT) trainings did not
exhibit a reduction in confidence
in their research career, in their
ability to communicate their
research, or in their publication
number. Contrary to current
belief, the data trended toward a
slight synergy between investing
in EBT and research prepara-
tion, suggesting that institutions
can integrate EBT training into
graduate programs without
reducing students’ research
success. Additionally, invest-
ment in EBT training can better
prepare graduate students for
the multifaceted role of a faculty
member. —MMc
PLOS ONE 13, e0199576 (2018).
HIBERNATION
Snowy bat caves Snow provides thermal protec-
tion from extreme temperatures,
a phenomenon capitalized on by
polar bears and people indig-
enous to parts of the Arctic. But
snow does not provide a cozy
environment, a likely reason
why more mammals have not
evolved to take advantage of
its protection against extreme
cold. Hirakawa and Nagasaka,
however, report that Ussurian
tube-nosed bats (Murina
ussuriensis) appear to create tiny
snow “caves” with their bodies,
which then serve as opportu-
nistic hibernacula. After coming
across anecdotal accounts of
small bats being found curled up
in the snow, the authors system-
atically searched for bats in such
conditions, finding more than
30 near Sapporo, Japan. The
animals displayed classic torpor
positions, curled nose-to-tail, and
decreased body temperatures.
The authors model conditions
under which the bats’ bodies
could create their small caves
and set forth several hypotheses
for hibernating conditions and
scenarios. The finding that these
bats use a snowy blanket for
hibernation protection opens up
the opportunity for many intrigu-
ing questions to be answered.
—SNV
Sci. Rep. 8, 12047 (2018).
BIOMATERIALS
Layers of bone repairThe repair of osteochondral
defects requires proper growth
of subchondral bone, articular
cartilage, and the interface
between them, but current treat-
ments have been more palliative
than curative. Kang et al. devel-
oped a trilayer scaffold, with
variations in the architecture
and mineral environment along
its depth. The bottom layer was
enhanced with calcium phos-
phate to recruit endogenous
cells, whereas the upper two
layers were loaded with donor
cells to support stratified carti-
lage formation. When implanted
in vivo, these trilayer scaffolds
formed osteochondral tissue
with a lubricin-rich cartilage
surface. —MSL
Acta Biomater. 10.1016/
j.actbio.2018.07.039 (2018).
Ussurian tube-nosed bats hibernate in tiny snow caves.
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Snowy bat cavesSacha Vignieri
DOI: 10.1126/science.361.6404.764-f (6404), 764-765.361Science
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