Table Of Contents Page, PNAS Volume 121, Number 14
This Week in PNAS
Opinion
Commentaries
Perspective
Ultraviolet radiation (UVR) is primarily recognized for its detrimental effects such
as cancerogenesis, skin aging, eye damage, and autoimmune disorders. With exception
of ultraviolet B (UVB) requirement in the production of vitamin D3, the positive role
...
Letters
Brief Report
Depression has robust natural language correlates and can increasingly be measured
in language using predictive models. However, despite evidence that language use varies
as a function of individual demographic features (e.g., age, gender), previous work
...
Physical Sciences
Applied Mathematics
Motivated by the implementation of a SARS-Cov-2 sewer surveillance system in Chile
during the COVID-19 pandemic, we propose a set of mathematical and algorithmic tools
that aim to identify the location of an outbreak under uncertainty in the network
...
The causal connectivity of a network is often inferred to understand network function.
It is arguably acknowledged that the inferred causal connectivity relies on the causality
measure one applies, and it may differ from the network’s underlying ...
Applied Physical Sciences
The structure of dislocation cores, the fundamental knowledge on crystal plasticity,
remains largely unexplored in covalent crystals. Here, we conducted atomically resolved
characterizations of dislocation core structures in a plastically deformed diamond
...
Granular media constitute the most abundant form of solid matter on Earth and beyond.
When external forces are applied to a granular medium, the forces are transmitted
through it via chains of contacts among grains—force chains. Understanding the spatial
...
Biophysics and Computational Biology
Trimethylamine-N-oxide (TMAO) and urea are metabolites that are used by some marine
animals to maintain their cell volume in a saline environment. Urea is a well-known
denaturant, and TMAO is a protective osmolyte that counteracts urea-induced protein
...
Stochastic reaction networks are widely used in the modeling of stochastic systems
across diverse domains such as biology, chemistry, physics, and ecology. However,
the comprehension of the dynamic behaviors inherent in stochastic reaction networks
is a ...
RNA decay is a crucial mechanism for regulating gene expression in response to environmental
stresses. In bacteria, RNA-binding proteins (RBPs) are known to be involved in posttranscriptional
regulation, but their global impact on RNA half-lives has not ...
Chemistry
Photochemical valence bond isomerization of a crystalline Dewar benzene (DB) diacid monoanion salt with an acetophenone-linked piperazinium cation that serves
as an intramolecular triplet energy sensitizer (DB-AcPh-Pz) exhibits a quantum chain reaction ...
Biological membrane potentials, or voltages, are a central facet of cellular life.
Optical methods to visualize cellular membrane voltages with fluorescent indicators
are an attractive complement to traditional electrode-based approaches, since imaging
...
Though YB6 and LaB6 share the same crystal structure, atomic valence electron configuration, and phonon
modes, they exhibit drastically different phonon-mediated superconductivity. YB6 superconducts below 8.4 K, giving it the second-highest critical ...
A concept of solar energy convertible zinc–air battery (SZAB) is demonstrated through
rational design of an electrode coupled with multifunction. The multifunctional electrode
is fabricated using nitrogen-substituted graphdiyne (N-GDY) with large π-...
The inherently low signal-to-noise ratio of NMR and MRI is now being addressed by
hyperpolarization methods. For example, iridium-based catalysts that reversibly bind
both parahydrogen and ligands in solution can hyperpolarize protons (SABRE) or ...
Chemical transformations near plasmonic metals have attracted increasing attention
in the past few years. Specifically, reactions occurring within plasmonic nanojunctions
that can be detected via surface and tip-enhanced Raman (SER and TER) scattering ...
The exploitation of novel wound healing methods with real-time infection sensing and
high spatiotemporal precision is highly important for human health. Pt-based metal-organic
cycles/cages (MOCs) have been employed as multifunctional antibacterial agents ...
Sulfur in nature consists of two abundant stable isotopes, with two more neutrons
in the heavy one (34S) than in the light one (32S). The two isotopes show similar physicochemical properties and are usually considered
an integral system for chemical ...
Protein–ligand complex formation is fundamental to biological function. A central
question is whether proteins spontaneously adopt binding-competent conformations to
which ligands bind conformational selection (CS) or whether ligands induce the binding-...
Earth, Atmospheric, and Planetary Sciences
Warmer temperatures and higher sea level than today characterized the Last Interglacial
interval [Pleistocene, 128 to 116 thousand years ago (ka)]. This period is a remarkable
deep-time analog for temperature and sea-level conditions as projected for 2100 ...
View related content:
Tropical paleobiology discovers biodiversity in a warmer past
Dust loading in West and South Asia has been a major environmental issue due to its
negative effects on air quality, food security, energy supply and public health, as
well as on regional and global weather and climate. Yet a robust understanding of
its ...
Pressure-induced transformations in an archetypal chalcogenide glass (GeSe2) have been investigated up to 157 GPa by X-ray absorption spectroscopy (XAS) and
molecular dynamics (MD) simulations. Ge and Se K-edge XAS data allowed simultaneous
tracking of ...
Central Asia (CA) is one of the world’s most significant arid regions, which is markedly
impacted by global warming. A better understanding of the dynamical processes governing
its Holocene climate variability is critical for a better understanding of ...
Engineering
In nature, leafhoppers cover their body surfaces with brochosomes as a protective
coating. These leafhopper-produced brochosomes are hollow, buckyball-shaped, nanoscopic
spheroids with through-holes distributed across their surfaces, representing a class
...
Intelligent electroactive material systems with self-adaptive mechanical memory and sequential logic
By synthesizing the requisite functionalities of intelligence in an integrated material
system, it may become possible to animate otherwise inanimate matter. A significant
challenge in this vision is to continually sense, process, and memorize information
...
Design tactics and mechanistic studies both remain as fundamental challenges during
the exploitations of earth-abundant molecular electrocatalysts for CO2 reduction, especially for the rarely studied Cr-based ones. Herein, a quaterpyridyl
CrIII catalyst ...
Partial cystectomy procedures for urinary bladder–related dysfunction involve long
recovery periods, during which urodynamic studies (UDS) intermittently assess lower
urinary tract function. However, UDS are not patient-friendly, they exhibit user-to-user
...
Aquatic locomotion is challenging for land-dwelling creatures because of the high
degree of fluidity with which the water yields to loads. We surprisingly found that
the Chinese rice grasshopper Oxya chinensis, known for its terrestrial acrobatics, could ...
The ability to selectively bind to antigenic peptides and secrete effector molecules
can define rare and low-affinity populations of cells with therapeutic potential in
emerging T cell receptor (TCR) immunotherapies. We leverage cavity-containing hydrogel
...
Environmental Sciences
It is well-known that highly reactive hydroxyl radicals (HO•) can be produced by the classic Fenton system and our recently discovered haloquinone/H2O2 system, but rarely from thiol-derivatives. Here, we found, unexpectedly, that HO• can be generated from ...
Physics
The flowing, jamming, and avalanche behavior of granular materials is satisfyingly
universal and vexingly hard to tune: A granular flow is typically intermittent and
will irremediably jam if too confined. Here, we show that granular metamaterials made
...
Diamond color centers have proven to be versatile quantum emitters and exquisite sensors
of stress, temperature, electric and magnetic fields, and biochemical processes. Among
color centers, the silicon-vacancy (SiV) defect exhibits high brightness, ...
We introduce a machine learning–based approach called ab initio generalized Langevin
equation (AIGLE) to model the dynamics of slow collective variables (CVs) in materials
and molecules. In this scheme, the parameters are learned from atomistic ...
The strange metal phase of correlated electrons materials was described in a recent
theory by a model of a Fermi surface coupled a two-dimensional quantum critical bosonic
field with a spatially random Yukawa coupling. With the assumption of self-...
Sustainability Science
Climate change persists as a pressing global issue due to high greenhouse gas emissions
from fossil fuel–based energy sources. A transition to a greener energy matrix combined
with carbon offsetting is imperative to mitigate the rate at which global ...
Social Sciences
Psychological and Cognitive Sciences
Facial emotion expressions play a central role in interpersonal interactions; these
displays are used to predict and influence the behavior of others. Despite their importance,
quantifying and analyzing the dynamics of brief facial emotion expressions ...
People want to “feel heard” to perceive that they are understood, validated, and valued.
Can AI serve the deeply human function of making others feel heard? Our research addresses
two fundamental issues: Can AI generate responses that make human ...
The contents and dynamics of spontaneous thought are important factors for personality
traits and mental health. However, assessing spontaneous thoughts is challenging due
to their unconstrained nature, and directing participants’ attention to report ...
Sustainability Science
Climate change persists as a pressing global issue due to high greenhouse gas emissions
from fossil fuel–based energy sources. A transition to a greener energy matrix combined
with carbon offsetting is imperative to mitigate the rate at which global ...
Biological Sciences
Agricultural Sciences
Throughout evolution, arboviruses have developed various strategies to counteract
the host’s innate immune defenses to maintain persistent transmission. Recent studies
have shown that, in addition to bacteria and fungi, the innate Toll-Dorsal immune
...
Applied Biological Sciences
In nature, leafhoppers cover their body surfaces with brochosomes as a protective
coating. These leafhopper-produced brochosomes are hollow, buckyball-shaped, nanoscopic
spheroids with through-holes distributed across their surfaces, representing a class
...
Energy metabolism is highly interdependent with adaptive cell migration in vivo. Mechanical
confinement is a critical physical cue that induces switchable migration modes of
the mesenchymal-to-amoeboid transition (MAT). However, the energy states in ...
Heparins have been invaluable therapeutic anticoagulant polysaccharides for over a
century, whether used as unfractionated heparin or as low molecular weight heparin
(LMWH) derivatives. However, heparin production by extraction from animal tissues
...
Dysregulation of polyamine metabolism has been implicated in cancer initiation and
progression; however, the mechanism of polyamine dysregulation in cancer is not fully
understood. In this study, we investigated the role of MUC1, a mucin protein ...
Biochemistry
Dephosphorylation of pSer51 of the α subunit of translation initiation factor 2 (eIF2αP) terminates signaling in the integrated stress response (ISR). A trimeric mammalian
holophosphatase comprised of a protein phosphatase 1 (PP1) catalytic subunit, the
...
Methanogenic archaea inhabiting anaerobic environments play a crucial role in the
global biogeochemical material cycle. The most universal electrogenic reaction of
their methane-producing energy metabolism is catalyzed by N 5-methyl-...
Malignant glioma exhibits immune evasion characterized by highly expressing the immune
checkpoint CD47. RNA 5-methylcytosine(m5C) modification plays a pivotal role in tumor
pathogenesis. However, the mechanism underlying m5C-modified RNA metabolism ...
Pv11 is the only animal cell line that, when preconditioned with a high concentration
of trehalose, can be preserved in the dry state at room temperature for more than
one year while retaining the ability to resume proliferation. This extreme desiccation
...
Biophysics and Computational Biology
Trimethylamine-N-oxide (TMAO) and urea are metabolites that are used by some marine
animals to maintain their cell volume in a saline environment. Urea is a well-known
denaturant, and TMAO is a protective osmolyte that counteracts urea-induced protein
...
Stochastic reaction networks are widely used in the modeling of stochastic systems
across diverse domains such as biology, chemistry, physics, and ecology. However,
the comprehension of the dynamic behaviors inherent in stochastic reaction networks
is a ...
Protein–ligand complex formation is fundamental to biological function. A central
question is whether proteins spontaneously adopt binding-competent conformations to
which ligands bind conformational selection (CS) or whether ligands induce the binding-...
Aquatic locomotion is challenging for land-dwelling creatures because of the high
degree of fluidity with which the water yields to loads. We surprisingly found that
the Chinese rice grasshopper Oxya chinensis, known for its terrestrial acrobatics, could ...
While the existence and functional role of class C G-protein-coupled receptors (GPCR)
dimers is well established, there is still a lack of consensus regarding class A and
B GPCR multimerization. This lack of consensus is largely due to the inherent ...
Tumor necrosis factor (TNF) receptor 1 (TNFR1) plays a pivotal role in mediating TNF
induced downstream signaling and regulating inflammatory response. Recent studies
have suggested that TNFR1 activation involves conformational rearrangements of preligand
...
Photodynamic therapy (PDT) relies on a series of photophysical and photochemical reactions
leading to cell death. While effective for various cancers, PDT has been less successful
in treating pigmented melanoma due to high light absorption by melanin. ...
Cell Biology
A major consequence of aging and stress, in yeast to humans, is an increased accumulation
of protein aggregates at distinct sites within the cells. Using genetic screens, immunoelectron
microscopy, and three-dimensional modeling in our efforts to ...
Mitochondria constantly fuse and divide for mitochondrial inheritance and functions.
Here, we identified a distinct type of naturally occurring fission, tail-autotomy
fission, wherein a tail-like thin tubule protrudes from the mitochondrial body and
...
Melanosomes are specific organelles dedicated to melanin synthesis and accumulation
in melanocytes. Autophagy is suggestively involved in melanosome degradation, although
the potential underlying molecular mechanisms remain elusive. In selective autophagy,...
Ecology
Consumers range from specialists that feed on few resources to generalists that feed
on many. Generalism has the clear advantage of having more resources to exploit, but
the costs that limit generalism are less clear. We explore two understudied costs
of ...
Climate change is affecting the phenology of organisms and ecosystem processes across
a wide range of environments. However, the links between organismal and ecosystem
process change in complex communities remain uncertain. In snow-dominated watersheds,
...
Despite experimental and observational studies demonstrating that biodiversity enhances
primary productivity, the best metric for predicting productivity at broad geographic
extents—functional trait diversity, phylogenetic diversity, or species richness—...
Environmental Sciences
Warmer temperatures and higher sea level than today characterized the Last Interglacial
interval [Pleistocene, 128 to 116 thousand years ago (ka)]. This period is a remarkable
deep-time analog for temperature and sea-level conditions as projected for 2100 ...
View related content:
Tropical paleobiology discovers biodiversity in a warmer past
Fine particulate matter (PM2.5) is globally recognized for its adverse implications on human health. Yet, remain
limited the individual contribution of particular PM2.5 components to its toxicity, especially considering regional disparities. Moreover,
...
Evolution
Understanding, predicting, and controlling the phenotypic consequences of genetic
and environmental change is essential to many areas of fundamental and applied biology.
In evolutionary biology, the generative process of development is a major source of
...
Immunology and Inflammation
The ability to selectively bind to antigenic peptides and secrete effector molecules
can define rare and low-affinity populations of cells with therapeutic potential in
emerging T cell receptor (TCR) immunotherapies. We leverage cavity-containing hydrogel
...
How T-cell receptor (TCR) characteristics determine subset commitment during T-cell
development is still unclear. Here, we addressed this question for innate-like T cells,
mucosal-associated invariant T (MAIT) cells, and invariant natural killer T (iNKT)
...
Medical Sciences
Motivated by the implementation of a SARS-Cov-2 sewer surveillance system in Chile
during the COVID-19 pandemic, we propose a set of mathematical and algorithmic tools
that aim to identify the location of an outbreak under uncertainty in the network
...
Apneic events are frightening but largely benign events that often occur in infants.
Here, we report apparent life-threatening apneic events in an infant with the homozygous
SCN1AL263V missense mutation, which causes familial hemiplegic migraine type 3 in ...
Host-directed therapies (HDTs) represent an emerging approach for bacterial clearance
during tuberculosis (TB) infection. While most HDTs are designed and implemented for
immuno-modulation, other host targets—such as nonimmune stromal components found in
...
Microbiology
RNA decay is a crucial mechanism for regulating gene expression in response to environmental
stresses. In bacteria, RNA-binding proteins (RBPs) are known to be involved in posttranscriptional
regulation, but their global impact on RNA half-lives has not ...
Motile bacteria use large receptor arrays to detect chemical and physical stimuli
in their environment, process this complex information, and accordingly bias their
swimming in a direction they deem favorable. The chemoreceptor molecules form tripod-like
...
Neuroscience
The causal connectivity of a network is often inferred to understand network function.
It is arguably acknowledged that the inferred causal connectivity relies on the causality
measure one applies, and it may differ from the network’s underlying ...
The contents and dynamics of spontaneous thought are important factors for personality
traits and mental health. However, assessing spontaneous thoughts is challenging due
to their unconstrained nature, and directing participants’ attention to report ...
Subcallosal cingulate (SCC) deep brain stimulation (DBS) is an emerging therapy for
refractory depression. Good clinical outcomes are associated with the activation of
white matter adjacent to the SCC. This activation produces a signature cortical evoked
...
Sensory adaptation allows neurons to adjust their sensitivity and responses based
on recent experience. The mechanisms that mediate continuous adaptation to stimulus
history over seconds- to hours-long timescales, and whether these mechanisms can operate
...
During foraging behavior, action values are persistently encoded in neural activity
and updated depending on the history of choice outcomes. What is the neural mechanism
for action value maintenance and updating? Here, we explore two contrasting network
...
Optimal feedback control provides an abstract framework describing the architecture
of the sensorimotor system without prescribing implementation details such as what
coordinate system to use, how feedback is incorporated, or how to accommodate changing
...
Physiology
Biological membrane potentials, or voltages, are a central facet of cellular life.
Optical methods to visualize cellular membrane voltages with fluorescent indicators
are an attractive complement to traditional electrode-based approaches, since imaging
...
Plant Biology
Polymethoxyflavones (PMFs) are a class of abundant specialized metabolites with remarkable
anticancer properties in citrus. Multiple methoxy groups in PMFs are derived from
methylation modification catalyzed by a series of hydroxylases and O-...
To preserve germination ability, plant seeds must be protected from environmental
stresses during the storage period. Here, we demonstrate that autophagy, an intracellular
degradation system, maintains seed germination ability in Arabidopsis thaliana. The ...
Psychological and Cognitive Sciences
Facial emotion expressions play a central role in interpersonal interactions; these
displays are used to predict and influence the behavior of others. Despite their importance,
quantifying and analyzing the dynamics of brief facial emotion expressions ...
Human working memory is a key cognitive process that engages multiple functional anatomical
nodes across the brain. Despite a plethora of correlative neuroimaging evidence regarding
the working memory architecture, our understanding of critical hubs ...
Corrections
Cover image: Pictured are nanoscopic brochosomes produced by the leafhopper Gyponana serpenta. Brochosomes are secreted by leafhoppers and confer an antireflective covering. Lin Wang et al. 3D-printed brochosomes with the same geometric features as their biological counterparts. Reflectance analysis of the synthetic brochosomes revealed that the narrow range of brochosome diameters is optimal for broadband light scattering and that the holes act as filters for short-wavelength light. According to the authors, brochosomes also reduce reflection of UV radiation, suggesting that the structures may reduce leafhoppers’ visibility to predators with UV vision. See the article by Wang et al. e2312700121. Image credit: Lin Wang and Tak-Sing Wong.
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