Science - USA (2018-12-21)

a Saturn-mass planet, trailing

behind it in its orbit. They com-

bined this with observations of

several other exoplanets to show

that atmospheres are being lost

more quickly by exoplanets that

are more strongly heated. —KTS

Science, this issue p. 1384, p. 1388;

see also p. 1360

MOLECULAR MAGNETS

Breaking through the

nitrogen ceiling

Single-molecule magnets

could prove useful in miniatur-

izing a wide variety of devices.

However, their application has

been severely hindered by the

need to cool them to extremely CREDITS: (TOP) ROCHA

ET AL

.; (BOTTOM) DANIEL VON WANGENHEIM

sciencemag.org SCIENCE

examples of quasicrystalline

superlattices formed from dif-

ferent types of particles are rare.

Nagaoka et al. discovered a type

of 10-fold quasicrystalline super-

lattice formed from truncated

tetrahedral quantum dots (see

the Perspective by Wu and Sun).

The order is driven by a “flex-

ible polygon tiling rule,” which

explains the unique arrangement

of the quantum dots. —BG

Science, this issue p. 1396;

see also p. 1354

MARINE PROTECTED AREAS

Not as advertised

Marine protected areas (MPAs)

have increasingly designated

globally, with an associated

EXOPLANET ATMOSPHERES

Helium escaping from

hot gas giants
Many gas giant exoplanets orbit
so close to their host star that
they are heated to high tem-
peratures, causing atmospheric
gases to escape. Gas giant atmo-
spheres are mostly hydrogen
and helium, which are difficult
to observe. Two papers have
now observed escaping helium
in the near-infrared (see the
Perspective by Brogi). Allart et al.
observed helium in a Neptune-
mass exoplanet and performed
detailed simulations of its atmo-
sphere, which put constraints
on the escape rate. Nortmann et
al. found that helium is escaping

Edited by Stella Hurtley

IN SCIENCE JOURNALS

RESEARCH

Network analysis of

ecosystem regime shifts

Rocha et al., p. 1379

low temperature using liquid

helium. Guo et al. now report

a dysprosium compound that

manifests magnetic hysteresis

at temperatures up to 80 kelvin.

The principles applied to tuning

the ligands in this complex could

point the way toward future

architectures with even higher

temperature performance. —JSY

Science, this issue p. 1400

Q UAS I C RYSTA L S

Quantum dots line up

as a quasicrystal

Quasicrystals have rotational

symmetry but no long-range

order. Although several materi-

als have quasicrystalline order,

PLANT SCIENCE

Rooting out the

mechanism of asymmetry

P

lant roots grow not in response to

architectural blueprints but rather

in search of scarce resources in

the soil. Orosa-Puente et al. show

why a new lateral root emerges

on the damp side of a root rather than

the dry side (see the Perspective by

Giehl and von Wirén). The transcription

factor ARF7 is found across the whole

root but acquires a posttranslational

modification on the dry side of the root,

which represses its function. ARF7

on the damp side remains functional

and is thus able to initiate the signal-

ing cascade that leads to a new lateral

root. —PJH

Science, this issue p. 1407; see also p. 1358

1372 21 DECEMBER 2018 • VOL 362 ISSUE 6421

Computer-generated image of

Arabidopsis thaliana root preferentially

branching toward moist soil.

Published by AAAS