Science - USA (2020-01-17)

SCIENCE sciencemag.org

enabling receptor recycling and

proper routing of cellular cargo.

—SMH

Science, this issue p.301;

see also p. 246

MAMMALIAN EVOLUTION

Making a mammalian ear

Mammals have keen hearing

owing to their complex inner

ear. In our vertebrate ances-

tors, as in extant reptiles, the

three bones that make up the

inner ear were instead part

of the jaw. Understanding the

functional transition of these

bones is challenging given their

small and delicate nature. Mao

et al. describe a new genus

and species of stem therian

mammal represented by six well-

preserved specimens, seemingly

caught as they slept huddled

together (see the Perspective

by Schultz). The unprecedented

preservation reveals a clear

transitional stage between the

two very different functions of

the bones. —SNV

Science, this issue p. 305;

see also p. 244

SOLAR PHYSICS

Magnetic energy

release in a solar flare

Solar flares are bright flashes

and associated eruptions of

plasma from the Sun that are

thought to be powered by violent

rearrangement of the magnetic

fields near sunspots. Fleishman

et al. observed a bright solar

flare with a microwave inter-

ferometer, allowing them to

map the magnetic field in the

solar corona and monitor how it

changed during the flare. They

Edited by Caroline Ash

and Jesse Smith

IN OTHER JOURNALS

FOREST ECOLOGY

The legacy of logging

Logging in tropical forests

affects the future ecosystem

functioning of the affected areas.

Swinfield et al. investigated how

logging affects the distribu-

tion of phosphorus, a key plant

nutrient, over a wide area in

Borneo. Spectroscopic imag-

ing of forest canopies showed

that the foliar concentrations

of phosphorus were lower in

logged than unlogged areas,

indicating that soil phosphorus

availability is decreased by log-

ging. Because soil phosphorus

is a key determinant of the tree

species composition of tropical

forests, the authors suggest that

repeated logging of tropical for-

est on relatively infertile soils will

lead to permanent, long-term

changes in nutrient cycling and

forest tree communities. —AMS

Glob. Chang. Biol. 10.1111/gcb.14903

(2019).

IMMUNOLOGY

Death suppression

resolves inflammation

Impaired signaling of tyro-

sine-protein phosphatase

found a large drop in the local

field strength over 2 minutes,

releasing enough magnetic

energy to power the entire solar

flare. Determining the origin of

this energy will help to predict

how strong future solar flares

may be and their potential space

weather impacts on Earth. —KTS

Science, this issue p. 278

ORGANOMETALLICS

Teaching bismuth

to make and break bonds

One major reason why transition

metals are good catalysts is that

they can shuttle between oxida-

tion states. This flexibility lets

them slide in and out of chemical

bonds; so, for instance, they can

snip a bond between carbon and

boron and then stitch a carbon-

fluorine bond in its place. Planas

et al. now report that bismuth

can also orchestrate such

bond-swapping events. They

implement a fully catalytic cycle

for fluorination of aryl boronates,

in which bismuth hops between

its +3 and +5 oxidation states.

—JSY

Science, this issue p. 313

TRANSPLANTATION

A better reception

for islets

Pancreatic islet transplanta-

tion can stabilize blood glucose

concentrations in individu-

als with type 1 diabetes, but

transplant function decreases

over time. Forbes et al. inves-

tigated the supportive effects

of cotransplanting islets and

human umbilical cord perivascu-

lar mesenchymal stromal cells

(HUCPVCs). HUCPVCs inhibited

T cells, expressed proregen-

erative and immune-regulatory

markers in vitro, and increased

islet vascularization in vivo.

Cotransplanting human islets

and HUCPVCs under the kidney

capsule or via the hepatic portal

vein improved control of blood

glucose in diabetic immunode-

ficient and immunocompetent

mouse models for up to 16

weeks. —CC

Sci. Transl. Med. 12 , eaan5907 (2020).

EDUCATION

Sex, physics, and anxiety

A

nxiety negatively affects academic performance, but little

is known about the neural mechanisms underlying anxiety

and STEM learning. To develop a more complete model

of anxiety-related mechanisms and learning strategies,

Gonzalez et al. evaluated anxiety and large-scale brain con-

nectivity in 101 undergraduate physics students, collecting both

self-reporting questionnaire and neuroimaging data. Results iden-

tified sex-specific relationships between STEM anxiety and brain

connectivity, with male students exhibiting distinct internetwork

connectivity for STEM and clinical anxiety and female students

demonstrating no significant within-sex correlations. Using these

data together with additional study results, the authors show that

sex differences in brain networks are not fixed and that STEM

anxiety is related to changes in both female and male students’

brains during the physics-learning process. —MMc

NPJ Sci. Learn. 4 , 18 (2019).

Solar f are and accompanying ejected

solar material

Gender-related differences in neural mechanisms (within the colored brain

regions) drive how anxiety is related to STEM learning.

PHOTOS: (LEFT TO RIGHT) NASA/SDO; A. A. GONZALEZ

ET AL., NPJ SCI. LEARN.

4 , 18 (2019)

17 JANUARY 2020 • VOL 367 ISSUE 6475 261

Published by AAAS