SCIENCE sciencemag.org 22 MAY 2020 • VOL 368 ISSUE 6493 842-C
CHEMICAL PHYSICS
Electronic and nuclear
dynamics in one
Because of the complex, ultra-
fast interplay between nuclear
and electronic degrees of free-
dom, probing both nuclear and
electronic dynamics in excited
electronic states within a single
time-resolved experiment is a
great challenge. Yang et al. used
ultrafast electron diffraction in
combination with ab initio non-
adiabatic molecular dynamics
and diffraction simulations to
study the relaxation dynamics of
isolated pyridine molecules after
photoexcitation to the S 1 state
(see the Perspective by Domcke
and Sobolewski). They showed
that electronic state evolu-
tion and molecular structural
changes can be recorded simul-
taneously and independently
by tracing a transient signal in
small-angle inelastic scattering
and large-angle elastic diffrac-
tion, respectively. —YS
Science, this issue p. 885;
see also p. 820
POLLINATORS
Bumble bee gardeners
Bumble bees rely heavily on
pollen resources for essential
nutrients as they build their
summer colonies. Therefore,
we might expect that annual
differences in the availability of
these resources must simply be
tolerated, but Pashalidou et al.
made observations suggesting
that bees may have strategies
to cope with irregular seasonal
flowering (see the Perspective
by Chittka). When faced with a
shortage of pollen, bumble bees
actively damaged plant leaves
in a characteristic way, and
this behavior resulted in earlier
flowering by as much as 30 days.
Experimenters were not able to
fully replicate the results with
their own damage, suggesting
that there is a distinct method
that the bees use to stimulate
earlier flowering. —SNV
Science, this issue p. 881;
see also p. 824
BONE
Screening for side-effect
susceptibility
Osteoporosis is typically treated
with nitrogen-containing
bisphosphonates (N-BPs) to
inhibit bone resorption; however,
N-BPs can cause serious side
effects, including osteonecrosis
and fracture. To understand sus-
ceptibility to these side effects,
Surface et al. investigated the
role of the gene ATRAID in medi-
ating response to N-BPs. Mice
deficient in this gene had weaker
bone and did not respond to
N-BP treatment in models of
osteoporosis. Patients with
coding variants in ATRAID taking
N-BPs presented with fractures
and osteonecrosis of the jaw.
The authors determined that
ATRAID is necessary for inhibi-
tion of osteoclast function by
N-BPs. It may thus be prudent
to screen patients for variants
in ATRAID to avoid N-BP side
effects. —CC
Sci. Transl. Med. 12 , eaav9166 (2020).Published by AAAS