Table Of Contents Page, PNAS Volume 119, Number 1
This Week in PNAS
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Perspectives
Dormancy is an evolutionarily conserved protective mechanism widely observed in nature.
A pathological example is found during cancer metastasis, where cancer cells disseminate
from the primary tumor, home to secondary organs, and enter a growth-arrested ...
About 50 y ago, Crow and Kimura [An Introduction to Population Genetics Theory (1970)] and Ohta and Kimura [Genet. Res. 22, 201–204 (1973)] laid the foundations of conservation genetics by predicting the
relationship between population size and genetic ...
Brief Reports
US state legislatures have proposed laws to prohibit abortion once the earliest embryonic
electrical activity is detectable (fetal “heartbeat”). On average, this occurs roughly
6 wk after the last menstrual period. To be eligible for abortion, people must ...
Nuclear noncoding RNAs (ncRNAs) are key regulators of gene expression and chromatin
organization. The progress in studying nuclear ncRNAs depends on the ability to identify
the genome-wide spectrum of contacts of ncRNAs with chromatin. To address this ...
Physical Sciences
Applied Mathematics
Abdominal aortic aneurysm (AAA) is a common degenerative cardiovascular disease whose
pathobiology is not clearly understood. The cellular heterogeneity and cell-type-specific
gene regulation of vascular cells in human AAA have not been well-...
We present a numerical method specifically designed for simulating three-dimensional
fluid–structure interaction (FSI) problems based on the reference map technique (RMT).
The RMT is a fully Eulerian FSI numerical method that allows fluids and large-...
Applied Physical Sciences
DNA-coated colloids can self-assemble into an incredible diversity of crystal structures,
but their applications have been limited by poor understanding and control over the
crystallization dynamics. To address this challenge, we use microfluidics to ...
Tiny water drops produced from bubble bursting play a critical role in forming clouds,
scattering sunlight, and transporting pathogens from water to the air. Bubbles burst
by nucleating a hole at their cap foot and may produce jets or film drops. The ...
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Biophysics and Computational Biology
Recent advances in super-resolution microscopy revealed the previously unknown nanoscopic
level of organization of endoplasmic reticulum (ER), one of the most vital intracellular
organelles. Membrane nanostructures of 10- to 100-nm intrinsic length scales,...
Most organisms grow in space, whether they are viruses spreading within a host tissue
or invasive species colonizing a new continent. Evolution typically selects for higher
expansion rates during spatial growth, but it has been suggested that slower ...
Living systems propagate by undergoing rounds of cell growth and division. Cell division
is at heart a physical process that requires mechanical forces, usually exerted by
assemblies of cytoskeletal polymers. Here we developed a physical model for the ...
The gut microbiota features important genetic diversity, and the specific spatial
features of the gut may shape evolution within this environment. We investigate the
fixation probability of neutral bacterial mutants within a minimal model of the gut
that ...
Several publications describing high-resolution structures of amyloid-β (Aβ) and other
fibrils have demonstrated that magic-angle spinning (MAS) NMR spectroscopy is an ideal
tool for studying amyloids at atomic resolution. Nonetheless, MAS NMR suffers ...
Ants, mice, and dogs often use surface-bound scent trails to establish navigation
routes or to find food and mates, yet their tracking strategies remain poorly understood.
Chemotaxis-based strategies cannot explain casting, a characteristic sequence of ...
Chemistry
Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic
manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however,
the lack of a high-...
Deoxypodophyllotoxin contains a core of four fused rings (A to D) with three consecutive
chiral centers, the last being created by the attachment of a peripheral trimethoxyphenyl
ring (E) to ring C. Previous studies have suggested that the iron(II)- and 2-...
The viscoelectric effect concerns the increase in viscosity of a polar liquid in an
electric field due to its interaction with the dipolar molecules and was first determined
for polar organic liquids more than 80 y ago. For the case of water, however, the
...
Conventional embeddings of the edge-graphs of Platonic polyhedra, {f, z}, where f, z denote the number of edges in each face and the edge-valence at each vertex, respectively,
are untangled in that they can be placed on a sphere () such that distinct ...
Geminal diols—organic molecules carrying two hydroxyl groups at the same carbon atom—have
been recognized as key reactive intermediates by the physical (organic) chemistry
and atmospheric science communities as fundamental transients in the aerosol cycle
...
Computer Sciences
Content on Twitter’s home timeline is selected and ordered by personalization algorithms.
By consistently ranking certain content higher, these algorithms may amplify some
messages while reducing the visibility of others. There’s been intense public and
...
Earth, Atmospheric, and Planetary Sciences
The Late Bronze Age Thera eruption was one of the largest natural disasters witnessed
in human history. Its impact, consequences, and timing have dominated the discourse
of ancient Mediterranean studies for nearly a century. Despite the eruption’s high
...
Planktonic organic matter forms the base of the marine food web, and its nutrient
content (C:N:Porg) governs material and energy fluxes in the ocean. Over Earth history, C:N:Porg had a crucial role in marine metazoan evolution and global biogeochemical ...
Light elements in Earth’s core play a key role in driving convection and influencing
geodynamics, both of which are crucial to the geodynamo. However, the thermal transport
properties of iron alloys at high-pressure and -temperature conditions remain ...
Engineering
Impulsive overeating is a common, disabling feature of eating disorders. Both continuous
deep brain stimulation (DBS) and responsive DBS, which limits current delivery to
pathological brain states, have emerged as potential therapies. We used in vivo ...
Solid–solid phase transformations can affect energy transduction and change material
properties (e.g., superelasticity in shape memory alloys and soft elasticity in liquid
crystal elastomers). Traditionally, phase-transforming materials are based on ...
Mixed matrix membranes (MMMs) are one of the most promising solutions for energy-efficient
gas separation. However, conventional MMM synthesis methods inevitably lead to poor
filler–polymer interfacial compatibility, filler agglomeration, and limited ...
Inspired by crystallography, the periodic assembly of trusses into architected materials
has enjoyed popularity for more than a decade and produced countless cellular structures
with beneficial mechanical properties. Despite the successful and steady ...
Physics
Unidirectional (“stripe”) charge density wave order has now been established as a
ubiquitous feature in the phase diagram of the cuprate high-temperature superconductors,
where it generally competes with superconductivity. Nonetheless, on theoretical ...
The quantitative understanding and precise control of complex dynamical systems can
only be achieved by observing their internal states via measurement and/or estimation.
In large-scale dynamical networks, it is often difficult or physically impossible
to ...
Relaxation of quantum systems is a central problem in nonequilibrium physics. In contrast
to classical systems, the underlying quantum dynamics results not only from atomic
interactions but also from the long-range coherence of the many-body wave ...
Social Sciences
Anthropology
Paleoclimatic evidence indicating a series of droughts in the Yucatan Peninsula during
the Terminal Classic period suggests that climate change may have contributed to the
disruption or collapse of Classic Maya polities. Although climate change cannot ...
The Late Bronze Age Thera eruption was one of the largest natural disasters witnessed
in human history. Its impact, consequences, and timing have dominated the discourse
of ancient Mediterranean studies for nearly a century. Despite the eruption’s high
...
Economic Sciences
Technological improvement is the most important cause of long-term economic growth.
In standard growth models, technology is treated in the aggregate, but an economy
can also be viewed as a network in which producers buy goods, convert them to new
goods, ...
Political Sciences
Content on Twitter’s home timeline is selected and ordered by personalization algorithms.
By consistently ranking certain content higher, these algorithms may amplify some
messages while reducing the visibility of others. There’s been intense public and
...
Psychological and Cognitive Sciences
The default mode network (DMN) is the most-prominent intrinsic connectivity network,
serving as a key architecture of the brain’s functional organization. Conversely,
dysregulated DMN is characteristic of major neuropsychiatric disorders. However, the
...
Individuals in all societies conform to their cultural group’s conventional norms,
from how to dress on certain occasions to how to play certain games. It is an open
question, however, whether individuals in all societies actively enforce the group’s
...
Over the past decade, choice architecture interventions or so-called nudges have received
widespread attention from both researchers and policy makers. Built on insights from
the behavioral sciences, this class of behavioral interventions focuses on the ...
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No evidence for nudging after adjusting for publication bias
Left-truncated effects and overestimated meta-analytic means
No reason to expect large and consistent effects of nudge interventions
This article has a correction:The recent emergence of machine-manipulated media raises an important societal question:
How can we know whether a video that we watch is real or fake? In two online studies
with 15,016 participants, we present authentic videos and deepfakes and ask ...
Biological Sciences
Agricultural Sciences
Flight ability is essential for the enormous diversity and evolutionary success of
insects. The migratory locusts exhibit flight capacity plasticity in gregarious and
solitary individuals closely linked with different density experiences. However, the
...
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Gregarious locusts down-regulate muscular catabolic capacities yet fly far
Anthropology
Paleoclimatic evidence indicating a series of droughts in the Yucatan Peninsula during
the Terminal Classic period suggests that climate change may have contributed to the
disruption or collapse of Classic Maya polities. Although climate change cannot ...
Individuals in all societies conform to their cultural group’s conventional norms,
from how to dress on certain occasions to how to play certain games. It is an open
question, however, whether individuals in all societies actively enforce the group’s
...
Biochemistry
Photosystem II (PSII) enables global-scale, light-driven water oxidation. Genetic
manipulation of PSII from the mesophilic cyanobacterium Synechocystis sp. PCC 6803 has provided insights into the mechanism of water oxidation; however,
the lack of a high-...
Deoxypodophyllotoxin contains a core of four fused rings (A to D) with three consecutive
chiral centers, the last being created by the attachment of a peripheral trimethoxyphenyl
ring (E) to ring C. Previous studies have suggested that the iron(II)- and 2-...
Cu/Zn superoxide dismutase (Sod1) is a highly conserved and abundant antioxidant enzyme
that detoxifies superoxide (O2•−) by catalyzing its conversion to dioxygen (O2) and hydrogen peroxide (H2O2). Using Saccharomyces cerevisiae and mammalian cells, we ...
Telomerase synthesizes telomeres at the ends of linear chromosomes by repeated reverse
transcription from a short RNA template. Crystal structures of Tribolium castaneum telomerase reverse transcriptase (tcTERT) and cryoelectron microscopy (cryo-EM) ...
Many soil-, water-, and plant-associated bacterial species from the orders Xanthomonadales,
Burkholderales, and Neisseriales carry a type IV secretion system (T4SS) specialized
in translocating effector proteins into other gram-negative species, leading ...
Biophysics and Computational Biology
Living systems propagate by undergoing rounds of cell growth and division. Cell division
is at heart a physical process that requires mechanical forces, usually exerted by
assemblies of cytoskeletal polymers. Here we developed a physical model for the ...
Recent advances in super-resolution microscopy revealed the previously unknown nanoscopic
level of organization of endoplasmic reticulum (ER), one of the most vital intracellular
organelles. Membrane nanostructures of 10- to 100-nm intrinsic length scales,...
Fitness functions map biological sequences to a scalar property of interest. Accurate
estimation of these functions yields biological insight and sets the foundation for
model-based sequence design. However, the fitness datasets available to learn these
...
RAS is a signaling protein associated with the cell membrane that is mutated in up
to 30% of human cancers. RAS signaling has been proposed to be regulated by dynamic
heterogeneity of the cell membrane. Investigating such a mechanism requires near-...
Defining the denatured state ensemble (DSE) and disordered proteins is essential to
understanding folding, chaperone action, degradation, and translocation. As compared
with water-soluble proteins, the DSE of membrane proteins is much less characterized.
...
Several publications describing high-resolution structures of amyloid-β (Aβ) and other
fibrils have demonstrated that magic-angle spinning (MAS) NMR spectroscopy is an ideal
tool for studying amyloids at atomic resolution. Nonetheless, MAS NMR suffers ...
Cell Biology
Symplasmicly connected cells called sieve elements form a network of tubes in the
phloem of vascular plants. Sieve elements have essential functions as they provide
routes for photoassimilate distribution, the exchange of developmental signals, and
the ...
Adenosine diphosphate (ADP)-ribosylation is a posttranslational modification involved
in key regulatory events catalyzed by ADP-ribosyltransferases (ARTs). Substrate identification
and localization of the mono-ADP-ribosyltransferase PARP12 at the trans-...
When nuclear membranes are stretched, the peripheral membrane enzyme cytosolic phospholipase
A2 (cPLA2) binds via its calcium-dependent C2 domain (cPLA2-C2) and initiates bioactive lipid signaling and tissue inflammation. More than 150
C2-like domains are ...
Developmental Biology
In mammals, circadian clocks are strictly suppressed during early embryonic stages,
as well as in pluripotent stem cells, by the lack of CLOCK/BMAL1-mediated circadian
feedback loops. During ontogenesis, the innate circadian clocks emerge gradually at
a ...
The development of a plastic root system is essential for stable crop production under
variable environments. Rice plants have two types of lateral roots (LRs): S-type (short
and thin) and L-type (long, thick, and capable of further branching). LR types ...
Ecology
Most organisms grow in space, whether they are viruses spreading within a host tissue
or invasive species colonizing a new continent. Evolution typically selects for higher
expansion rates during spatial growth, but it has been suggested that slower ...
Disentangling the roles of the external environment and internal biotic drivers of
plant population dynamics is challenging due to the absence of relevant physiological
and abundance information over appropriate space and time scales. Remote observations
...
The stoichiometric coupling of carbon to limiting nutrients in marine phytoplankton
regulates the magnitude of biological carbon sequestration in the ocean. While clear
links between plankton C:N ratios and environmental drivers have been identified,
the ...
Evolution
The gut microbiota features important genetic diversity, and the specific spatial
features of the gut may shape evolution within this environment. We investigate the
fixation probability of neutral bacterial mutants within a minimal model of the gut
that ...
Planktonic organic matter forms the base of the marine food web, and its nutrient
content (C:N:Porg) governs material and energy fluxes in the ocean. Over Earth history, C:N:Porg had a crucial role in marine metazoan evolution and global biogeochemical ...
Millions of species are currently being sequenced, and their genomes are being compared.
Many of them have more complex genomes than model systems and raise novel challenges
for genome alignment. Widely used local alignment strategies often produce ...
How cooperation emerges in human societies is both an evolutionary enigma and a practical
problem with tangible implications for societal health. Population structure has long
been recognized as a catalyst for cooperation because local interactions ...
Animals have repeatedly evolved specialized organs and anatomical structures to produce
and deliver a mixture of potent bioactive molecules to subdue prey or predators—venom.
This makes it one of the most widespread, convergent functions in the animal ...
Genetics
Abdominal aortic aneurysm (AAA) is a common degenerative cardiovascular disease whose
pathobiology is not clearly understood. The cellular heterogeneity and cell-type-specific
gene regulation of vascular cells in human AAA have not been well-...
Ancient DNA recovered from Pleistocene sediments represents a rich resource for the
study of past hominin and environmental diversity. However, little is known about
how DNA is preserved in sediments and the extent to which it may be translocated between
...
Immunology and Inflammation
Infection by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) provokes
a potentially fatal pneumonia with multiorgan failure, and high systemic inflammation.
To gain mechanistic insight and ferret out the root of this immune dysregulation,
we ...
Type I interferons (IFNs) are the first frontline of the host innate immune response
against invading pathogens. Herein, we characterized an unknown protein encoded by
phospholipase A2 inhibitor and LY6/PLAUR domain-containing (PINLYP) gene that ...
Macrophages induce a number of inflammatory response genes in response to stimulation
with microbial ligands. In response to endotoxin Lipid A, a gene-activation cascade
of primary followed by secondary-response genes is induced. Epigenetic state is an
...
Medical Sciences
The interaction of signal regulatory protein α (SIRPα) on macrophages with CD47 on
cancer cells is thought to prevent antibody (Ab)-dependent cellular phagocytosis (ADCP)
of the latter cells by the former. Blockade of the CD47-SIRPα interaction by Abs to
...
SF3B1 is the most frequently mutated RNA splicing factor in cancer, including in ∼25%
of myelodysplastic syndromes (MDS) patients. SF3B1-mutated MDS, which is strongly
associated with ringed sideroblast morphology, is characterized by ineffective ...
Brain metastases are a leading cause of death in patients with breast cancer. The
lack of clinical trials and the presence of the blood–brain barrier limit therapeutic
options. Furthermore, overexpression of the human epidermal growth factor receptor
2 (...
Microbiology
Appended to the 5′ end of nascent RNA polymerase II transcripts is 7-methyl guanosine
(m7G-cap) that engages nuclear cap-binding complex (CBC) to facilitate messenger RNA
(mRNA) maturation. Mature mRNAs exchange CBC for eIF4E, the rate-limiting ...
Coxiella burnetii is a bacterial pathogen that replicates within host cells by establishing a membrane-bound
niche called the Coxiella-containing vacuole. Biogenesis of this compartment requires effectors of its Dot/Icm
type IV secretion system. A large ...
The biogenesis of integral β-barrel outer membrane proteins (OMPs) in gram-negative
bacteria requires transport by molecular chaperones across the aqueous periplasmic
space. Owing in part to the extensive functional redundancy within the periplasmic
...
The COVID-19 pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)
infection has resulted in tremendous loss worldwide. Although viral spike (S) protein
binding of angiotensin-converting enzyme 2 (ACE2) has been established, the ...
The assembly and maintenance of microbial diversity in natural communities, despite
the abundance of toxin-based antagonistic interactions, presents major challenges
for biological understanding. A common framework for investigating such antagonistic
...
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a highly transmissible
coronavirus responsible for the global COVID-19 pandemic. Herein, we provide evidence
that SARS-CoV-2 spreads through cell–cell contact in cultures, mediated by the ...
Neuroscience
Impulsive overeating is a common, disabling feature of eating disorders. Both continuous
deep brain stimulation (DBS) and responsive DBS, which limits current delivery to
pathological brain states, have emerged as potential therapies. We used in vivo ...
The default mode network (DMN) is the most-prominent intrinsic connectivity network,
serving as a key architecture of the brain’s functional organization. Conversely,
dysregulated DMN is characteristic of major neuropsychiatric disorders. However, the
...
The perception of pain is shaped by somatosensory information about threat. However,
pain is also influenced by an individual’s expectations. Such expectations can result
in clinically relevant modulations and abnormalities of pain. In the brain, sensory
...
Pharmacology
Cyclic adenosine monophosphate (cAMP) is a pivotal second messenger with an essential
role in neuronal function. cAMP synthesis by adenylyl cyclases (AC) is controlled
by G protein–coupled receptor (GPCR) signaling systems. However, the network of ...
Physiology
Airway remodeling and airway hyperresponsiveness are central drivers of asthma severity.
Airway remodeling is a structural change involving the dedifferentiation of airway
smooth muscle (ASM) cells from a quiescent to a proliferative and secretory ...
Plant Biology
Plant cells can be distinguished from animal cells by their cell walls and high-turgor
pressure. Although changes in turgor and the stiffness of cell walls seem coordinated,
we know little about the mechanism responsible for coordination. Evidence has ...
In Arabidopsis, vacuolar sorting receptor isoform 1 (VSR1) sorts 12S globulins to the protein storage
vacuoles during seed development. Vacuolar sorting is mediated by specific protein–protein
interactions between VSR1 and the vacuolar sorting determinant ...
Psychological and Cognitive Sciences
Perhaps the most recognizable sensory map in all of neuroscience is the somatosensory
homunculus. Although it seems straightforward, this simple representation belies the
complex link between an activation in a somatotopic map and the associated touch ...
Corrections
View the original article:
Cover image: Pictured are tangled versions of classic Platonic solids or polyhedra: a tetrahedron, cube, octahedron, dodecahedron, and icosahedron (clockwise from top). By wrapping multistrand helices around the edges of conventional polyhedra, Stephen T. Hyde and Myfanwy E. Evans constructed the tangled versions, which contain symmetrical vertices, edges, and faces as well as kinked edges to allow entanglement. The authors report that a variety of maximally symmetric entanglements are possible for each polyhedron. According to the authors, simple forms of tangled polyhedra can be found in synthetic organometallic materials as well as in clathrin networks, which are lattices that enclose intracellular vesicles involved in protein transport. See the article by Hyde and Evans, e2110345118. Image credit: Myfanwy E. Evans.
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