Table Of Contents Page, PNAS Volume 121, Number 50
Special Feature
Sustainability of Animal-Sourced Foods and Plant-Based Alternatives
The high emissions intensity of terrestrial animal source food (TASF) and projected
increasing demand in low- and middle-income countries (LMIC) have spurred interest
in the development of animal-free alternatives and manufactured food items that aim
to ...
Plant-based proteins are promoted as nutritious, environmentally safe, and a key element
for food security. Numerous studies using environmental life cycle assessments confirmed
plant-based meat alternatives are more environmentally favorable than animal-...
The world faces a global challenge of how to meet the nutritional needs of a diverse
global population through diets. This paper defines the relative nutritional needs
across each stage of the life cycle to support human health and identifies who is
...
Child undernutrition remains a widespread public health problem in the Global South,
especially in Africa. Childhood stunting—meaning linear growth retardation—is a comprehensive
and commonly used indicator of chronic child undernutrition and is mostly ...
The ruminant livestock sector considerably contributes to global greenhouse gas emissions.
This study investigates the effectiveness of pelleted bromoform-containing seaweed
(Asparagopsis taxiformis) (Brominata) as an enteric methane (CH4) inhibitor in ...
Consumer interest in meat and dairy alternatives drives demand for plant-based protein
ingredients. While soy and gluten dominate the market, there is a trend to explore
alternative crops for functional ingredient production. The multitude of ingredients
...
Reducing meat and dairy intake has been identified as a necessary strategy for mitigating
the high environmental impacts food systems are currently having on climate change,
biodiversity loss associated with land-use changes, and freshwater use. Having a ...
Efforts to promote sustainable resource use through reduced meat consumption face
challenges as global meat consumption persists. The resistance may be attributed to
the lower sales price of meat compared to most plant-based meat alternatives (PBMAs).
...
Encouraging consumption of plant-based food products can help mitigate the impact
of dietary choices on climate change. Research suggests that modifying environments
in which people make purchasing decisions has the potential to achieve behavioral
changes ...
The Planetary Health Diet (PHD), also known as the EAT-Lancet reference diet, was
developed to optimize global dietary quality while keeping the environmental impacts
of food production within sustainable planetary boundaries. We calculated current
...
Reduced consumption of animal-sourced food (ASF) has been recommended for environmental
and human health objectives; however, ASF can be important for food security and diet
affordability. We explored country-level relationships among various metrics of ...
This Week in PNAS
Opinion
Commentaries
Perspective
Research funding systems fundamentally influence how science operates. This paper
aims to analyze the allocation of competitive research funding from different perspectives:
How reliable are decision processes for funding? What are the economic costs of ...
Physical Sciences
Applied Mathematics
Rapid movement is rare in the plant kingdom, but a prerequisite for ballistic seed
dispersal. A particularly dramatic example of rapid motion in plants is the squirting
cucumber (Ecballium elaterium) which launches its seeds explosively via a high-...
In fighting infectious diseases posing a global health threat, ranging from influenza
to Zika, nonpharmaceutical interventions (NPI), such as social distancing and face
covering, remain mitigation measures public health can resort to. However, the success
...
In many complex systems encountered in the natural and social sciences, mechanisms
governing system dynamics at a microscale depend upon the values of state variables
characterizing the system at coarse-grained, macroscale (Goldenfeld and Woese, 2011,
...
Applied Physical Sciences
Understanding the impact of digital platforms on user behavior presents foundational
challenges, including issues related to polarization, misinformation dynamics, and
variation in news consumption. Comparative analyses across platforms and over different
...
Mechanical properties of disordered materials are governed by their underlying free
energy landscape. In contrast to external fields, embedding a small fraction of active
particles within a disordered material generates nonequilibrium internal fields, ...
Mobula rays have evolved leaf-shaped filter structures to separate food particles
from seawater, which function similarly to industrial cross-flow filters. Unlike cross-flow
filtration, where permeability and selectivity are rationally designed following ...
The design of synthetic soft matter capable of emulating the complex behaviors of
living organisms, such as sensing and adapting to their environment, remains an important
challenge in developing biomimetic materials. Functionalized hydrogels are ideal ...
Phase transition between ordered phases has garnered attention from the viewpoint
of materials science as well as statistical physics. One interesting example is martensitic
transformation and the resulting formation of twin structures, in which atoms or ...
Solute transport and biogeochemical reactions in porous and fractured media flows
are controlled by mixing, as are subsurface engineering operations such as contaminant
remediation, geothermal energy production, and carbon sequestration. Porous media
...
Biophysics and Computational Biology
Liquid–liquid phase separation (LLPS) is an intracellular process widely used by cells
for many key biological functions. It occurs in complex and crowded environments,
where amino acids (AAs) are vital components. We have found that AAs render the net
...
Intrinsically disordered proteins (IDPs) adopt ensembles of rapidly fluctuating heterogeneous
conformations, influencing their binding capabilities and supramolecular transitions.
The primary conformational descriptors for understanding IDP ensembles—the ...
HIV, like other membrane-enveloped viruses, has protein spikes that include a fusion
peptide (Fp) segment that binds the host cell membrane and plays a critical role in
fusion (joining) viral and cell membranes. The HIV Fp is the ~23 N-terminal residues
...
Many microorganisms exhibit upstream swimming, which is important to many biological
processes and can cause contamination of biomedical devices and the infection of organs.
This process, called rheotaxis, has been studied extensively in Newtonian fluids.
...
Understanding the biophysical basis of protein aggregation is important in biology
because of the potential link to several misfolding diseases. Although experiments
have shown that protein aggregates adopt a variety of morphologies, the dynamics of
their ...
The stability of ecological communities has a profound impact on humans, ranging from
individual health influenced by the microbiome to ecosystem services provided by fisheries.
A long-standing goal of ecology is the elucidation of the interplay between ...
Motile organisms can expand into new territories and increase their fitness, while
nonmotile viruses usually depend on host migration to spread across long distances.
In general, faster host motility facilitates virus transmission. However, recent ...
Chemistry
Magnetotactic bacteria have evolved the remarkable capacity to biomineralize chains
of magnetite [Fe(II)Fe(III)2O4] nanoparticles that align along the geomagnetic field and optimize their navigation
in the environment. Mechanisms enabling magnetite ...
The dissolution of active atoms under operating potential will lead to a decline in
their oxygen evolution reaction (OER) performance, thus preventing the current highly
active catalysts from being practically applicable in industrial water electrolysis.
...
Metathesis reactions that operate cleanly and reversibly under biocompatible conditions
are crucial in diverse fields such as drug development, chemical biology, and dynamic
combinatorial chemistry. This paper introduces an innovative strategy using the ...
Lithium-rich layered oxides (LLOs) hold the promise for high-energy battery cathodes.
However, its application has been hindered by voltage decay associated with irreversible
reactions at high voltages despite decades of intensive efforts. Here, we first ...
Fischer-Tropsch synthesis represents a key endeavor aimed at converting nonpetroleum
carbon resources into clean fuels and valuable chemicals. However, the current state-of-the-art
industrial FTS employing Fe-based catalysts is still challenged by the low ...
Photoinduced ultrafast multielectron transfer (m-ET) and long-lived charge-accumulated
states in single molecules hold promise for light-energy conversion and utilization.
However, compared to single-electron transfer (s-ET), m-ET tends to be ...
Photolyase and cryptochrome belong to a group of structurally similar flavoproteins
but with two distinct functions of DNA repair as a photoenzyme and signal transduction
as a photoreceptor, respectively, under blue-light illumination. Here, we studied
a ...
Autophagy is a conserved catabolic process crucial for maintaining cellular homeostasis
and has emerged as a promising therapeutic target for many diseases. Mechanistically
novel small-molecule autophagy regulators are highly desirable from a ...
Earth, Atmospheric, and Planetary Sciences
Arctic shorelines are vulnerable to climate change impacts as sea level rises, permafrost
thaws, storms intensify, and sea ice thins. Seventy-five years of aerial and satellite
observations have established coastal erosion as an increasing Arctic hazard. ...
Foraminifera are unicellular protists capable of precipitating calcite tests, which
fossilize and preserve geochemical signatures of past environmental conditions dating
back to the Cambrian period. The biomineralization mechanisms responsible for the
...
Engineering
Aqueous organic redox flow batteries (AORFBs), which exploit the reversible redox
reactions of water-soluble organic electrolytes to store electricity, have emerged
as a promising electrochemical energy storage technology. Organic electrolytes possess
...
Polymer film dielectrics are highly favored for capacitive energy storage due to the
inherent advantages of high breakdown strength, low dielectric loss, and ease of processing.
High-density renewables conversion and harsh-condition electrification ...
Environmental Sciences
Increasing food production and ensuring drinking water safety have always been a focus
of attention, especially for people in underdeveloped regions of the world. Traditional
excessive fertilizer applications have increased crop yield but also caused ...
Physics
In unconventional superconductors, coupled charge and lattice degrees of freedom can
manifest in ordered phases of matter that are intertwined. In the cuprate family,
fluctuating short-range charge correlations can coalesce into a longer-range charge
...
Dirac fluids—interacting systems obeying particle–hole symmetry and Lorentz invariance—are
among the simplest hydrodynamic systems; they have also been studied as effective
descriptions of transport in strongly interacting Dirac semimetals. Direct ...
The high-temperature superconducting cuprates host unidirectional spin- and charge-density-wave
orders that can intertwine with superconductivity in nontrivial ways. While the charge
components of these stripes have now been observed in nearly all cuprate ...
Emergent electronic phenomena, from superconductivity to ferroelectricity, magnetism,
and correlated many-body band gaps, have been observed in domains created by stacking
and twisting atomic layers of Van der Waals materials. In graphene, emergent ...
Recent experiments suggest a new paradigm toward novel colossal magnetoresistance
(CMR) in a family of materials EuMX (M Cd, In, Zn; X P, As), distinct from the traditional avenues involving Kondo–Ruderman–Kittel–Kasuya–Yosida
crossovers, magnetic phase ...
A long-standing problem in the study of the under-hole-doped cuprates has been the
description of the Fermi surfaces underlying the high magnetic field quantum oscillations,
and their connection to the higher temperature pseudogap metal. Harrison and ...
Strong laser pulses can control superconductivity, inducing nonequilibrium transient
pairing by leveraging strong-light matter interaction. Here, we demonstrate theoretically
that equilibrium ground-state phonon-mediated superconductive pairing can be ...
Sustainability Science
Arctic shorelines are vulnerable to climate change impacts as sea level rises, permafrost
thaws, storms intensify, and sea ice thins. Seventy-five years of aerial and satellite
observations have established coastal erosion as an increasing Arctic hazard. ...
As the largest oil and gas producer in the United States, Texas confronts significant
challenges in its shift toward decarbonization. This study explores the potential
for green hydrogen in Texas as a substitute for current development, underscoring
...
Social Sciences
Environmental Sciences
As the largest oil and gas producer in the United States, Texas confronts significant
challenges in its shift toward decarbonization. This study explores the potential
for green hydrogen in Texas as a substitute for current development, underscoring
...
Political Sciences
Direct reciprocity is a wide-spread mechanism for the evolution of cooperation. In
repeated interactions, players can condition their behavior on previous outcomes.
A well-known approach is given by reactive strategies, which respond to the coplayer’s
...
Psychological and Cognitive Sciences
Language is a productive system––we routinely produce well-formed utterances that
we have never heard before. It is, however, difficult to assess when children first
achieve linguistic productivity simply because we rarely know all the utterances a
child ...
View related content:
Understanding the impact of digital platforms on user behavior presents foundational
challenges, including issues related to polarization, misinformation dynamics, and
variation in news consumption. Comparative analyses across platforms and over different
...
Learning requires changing the brain. This typically occurs through experience, study,
or instruction. We report an alternate route for humans to acquire visual knowledge,
through the direct sculpting of activity patterns in the human brain that mirror ...
Deception is a universal human behavior. Yet longstanding skepticism about the validity
of measures used to characterize the biological mechanisms underlying deceptive behavior
has relegated such studies to the scientific periphery. Here, we address these ...
Social Sciences
A large body of research documents the barriers faced by first-generation, low-income
(FGLI) students as “hidden minorities” on elite college campuses. Although existing
studies show brief psychological interventions can help mitigate some of these ...
Fact checking can be an effective strategy against misinformation, but its implementation
at scale is impeded by the overwhelming volume of information online. Recent AI language
models have shown impressive ability in fact-checking tasks, but how humans ...
Active labor market programs (ALMPs) are widely used to speed up return to work among
the unemployed. We examine their long-run effects on employment- and health-related
outcomes for different target groups, arguing that ALMPs are associated with ...
Unlike traditional approaches to Greco-Roman medicine, which are strongly based on
textual evidence, we addressed some problems, currently debated by historians, through
a technique borrowed from the biological sciences: We reenacted an ancient anatomical
...
Biological Sciences
Anthropology
Unlike traditional approaches to Greco-Roman medicine, which are strongly based on
textual evidence, we addressed some problems, currently debated by historians, through
a technique borrowed from the biological sciences: We reenacted an ancient anatomical
...
Biochemistry
Foraminifera are unicellular protists capable of precipitating calcite tests, which
fossilize and preserve geochemical signatures of past environmental conditions dating
back to the Cambrian period. The biomineralization mechanisms responsible for the
...
Vacuolar-type ATPases (V-ATPases) are membrane-embedded proton pumps that acidify
intracellular compartments in almost all eukaryotic cells. Homologous with ATP synthases,
these multisubunit enzymes consist of a soluble catalytic V1 subcomplex and a ...
The oxidative pentose phosphate (OPP) pathway is a fundamental carbon catabolic route
for generating reducing power and metabolic intermediates for biosynthetic processes.
In addition, its first two reactions form the OPP shunt, which replenishes the ...
Lysine lactylation (Kla) is a new type of histone mark implicated in the regulation
of various functional processes such as transcription. However, how this histone mark
acts in cancers remains unexplored due in part to a lack of knowledge about its ...
Biophysics and Computational Biology
Liquid–liquid phase separation (LLPS) is an intracellular process widely used by cells
for many key biological functions. It occurs in complex and crowded environments,
where amino acids (AAs) are vital components. We have found that AAs render the net
...
Intrinsically disordered proteins (IDPs) adopt ensembles of rapidly fluctuating heterogeneous
conformations, influencing their binding capabilities and supramolecular transitions.
The primary conformational descriptors for understanding IDP ensembles—the ...
Photolyase and cryptochrome belong to a group of structurally similar flavoproteins
but with two distinct functions of DNA repair as a photoenzyme and signal transduction
as a photoreceptor, respectively, under blue-light illumination. Here, we studied
a ...
Understanding the biophysical basis of protein aggregation is important in biology
because of the potential link to several misfolding diseases. Although experiments
have shown that protein aggregates adopt a variety of morphologies, the dynamics of
their ...
The toxic effects of C9orf72-derived arginine-rich dipeptide repeats (R-DPRs) on cellular
stress granules in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia
remain unclear at the molecular level. Stress granules are formed through the ...
Cortical condensates, transient punctate-like structures rich in actin and the actin
nucleation pathway member Neural Wiskott-Aldrich syndrome protein (N-WASP), form during
activation of the actin cortex in the Caenorhabditis elegans oocyte. Their ...
Despite the tremendous accomplishments of AlpaFold2/3 in predicting biomolecular structure,
the protein folding problem remains unsolved in the sense that accurate atomistic
models of how protein molecules fold into their native conformations from an ...
The regulation of heart function is attributed to a dual filament mechanism: i) the
Ca2+-dependent structural changes in the regulatory proteins of the thin, actin-containing
filament making actin available for myosin motor attachment, and ii) the release ...
We developed an advanced optical microscope for the simultaneous visualization of
membrane fluidity and morphology to define cell adhesion signatures. This microscope
combines ratiometric spectral imaging of membrane fluidity and interferometric imaging
...
The living cell creates a unique internal molecular environment that is challenging
to characterize. By combining single-molecule displacement/diffusivity mapping (SMdM) with physiologically active extracts prepared from Xenopus laevis eggs, we sought to ...
Cell Biology
Autophagy is a conserved catabolic process crucial for maintaining cellular homeostasis
and has emerged as a promising therapeutic target for many diseases. Mechanistically
novel small-molecule autophagy regulators are highly desirable from a ...
RAD51 is related to the bacterial RecA protein and is best known for its role in homologous
recombination-mediated repair of DNA damage. Here, we report an unexpected function
of RAD51 in the maintenance methylation of genomic DNA, a function that is ...
The p38 MAP kinase (MAPK) signaling pathway plays pivotal roles in various cellular
processes. Phosphorylation serves as a canonical way to regulate p38α activation through
a phosphorylation cascade. Thus, understanding the mechanism governing p38α ...
Oral squamous cell carcinoma (OSCC) is a subtype of head and neck cancer that arises
in the multilayered epithelia of the mouth and lips. Although inactivating mutations
in CASP8 are frequently found in human OSCC their role in the disease is unknown. To ...
The consequences of reactive oxygen species (ROS) in cancer cells are complex and
have been shown to both promote and retard tumorigenesis in different models. In mouse
models of pancreatic ductal adenocarcinoma (PDAC), loss of the antioxidant defense
...
Fibrosis drives end-organ damage in many diseases. However, clinical trials targeting
individual upstream activators of fibroblasts, such as TGFβ, have largely failed.
Here, we target the leukemia inhibitory factor receptor (LIFR) as an “autocrine master
...
A hallmark of neurodegenerative diseases (NDs) is the progressive loss of proteostasis,
leading to the accumulation of misfolded proteins or protein aggregates, with subsequent
cytotoxicity. To combat this toxicity, cells have evolved degradation pathways ...
Ecology
In many complex systems encountered in the natural and social sciences, mechanisms
governing system dynamics at a microscale depend upon the values of state variables
characterizing the system at coarse-grained, macroscale (Goldenfeld and Woese, 2011,
...
The stability of ecological communities has a profound impact on humans, ranging from
individual health influenced by the microbiome to ecosystem services provided by fisheries.
A long-standing goal of ecology is the elucidation of the interplay between ...
Climate warming can alleviate temperature and nutrient constraints on tree growth
in boreal regions, potentially enhancing boreal productivity. However, in permafrost
environments, warming also disrupts the physical foundation on which trees grow, leading
...
Evolution
Direct reciprocity is a wide-spread mechanism for the evolution of cooperation. In
repeated interactions, players can condition their behavior on previous outcomes.
A well-known approach is given by reactive strategies, which respond to the coplayer’s
...
Spatial games provide a simple and elegant mathematical model to study the evolution
of cooperation in networks. In spatial games, individuals reside in vertices, adopt
simple strategies, and interact with neighbors to receive a payoff. Depending on their
...
Genetics
Epithelial–mesenchymal transition (EMT) involves profound changes in cell morphology,
driven by transcriptional and epigenetic reprogramming. However, evidence suggests
that translation and ribosome composition also play key roles in establishing ...
Immunology and Inflammation
Myalgic encephalomyelitis/chronic fatigue syndrome (ME) is a severe, debilitating
disease, with substantial evidence pointing to immune dysregulation as a key contributor
to pathophysiology. To characterize the gene regulatory state underlying T cell ...
Proliferating tumor cells take up glutamine for anabolic processes, engendering glutamine
deficiency in the tumor microenvironment. How this might impact immune cells is not
well understood. Using multiple mouse models of soft tissue sarcomas, glutamine ...
Medical Sciences
Recent discoveries have revealed that genetic variants in γ-aminobutyric acid type
A (GABAA) receptor subunits can lead to both gain-of-function (GOF) and loss-of-function (LOF)
receptors. GABAA receptors, however, have a pseudosymmetrical pentameric ...
There are three distinct forms of autophagy, namely, macroautophagy, microautophagy,
and HSPA8 chaperone-mediated autophagy (CMA). While macroautophagy is widely recognized
as a regulator of chromosomal instability (CIN) through various pathways, the ...
Microbiology
Magnetotactic bacteria have evolved the remarkable capacity to biomineralize chains
of magnetite [Fe(II)Fe(III)2O4] nanoparticles that align along the geomagnetic field and optimize their navigation
in the environment. Mechanisms enabling magnetite ...
OmpA, a predominant outer membrane (OM) protein in Escherichia coli, affects virulence, adhesion, and bacterial OM integrity. However, despite more than
50 y of research, the molecular basis for the role of OmpA has remained elusive. In
this study, we ...
Neuroscience
Learning requires changing the brain. This typically occurs through experience, study,
or instruction. We report an alternate route for humans to acquire visual knowledge,
through the direct sculpting of activity patterns in the human brain that mirror ...
Deception is a universal human behavior. Yet longstanding skepticism about the validity
of measures used to characterize the biological mechanisms underlying deceptive behavior
has relegated such studies to the scientific periphery. Here, we address these ...
When we vocalize, our brain distinguishes self-generated sounds from external ones.
A corollary discharge signal supports this function in animals; however, in humans,
its exact origin and temporal dynamics remain unknown. We report electrocorticographic
...
The gray mouse lemur (Microcebus murinus), one of the smallest living primates, emerges as a promising model organism for
neuroscience research. This is due to its genetic similarity to humans, its evolutionary
position between rodents and humans, and its ...
The brain has evolved mechanisms to dynamically modify blood flow, enabling the timely
delivery of energy substrates in response to local metabolic demands. Several such
neurovascular coupling (NVC) mechanisms have been identified, but the vascular signal
...
Ultrasound neuromodulation has become an innovative technology that enables noninvasive
intervention in mammalian brain circuits with high spatiotemporal precision. Despite
the expanding utility of ultrasound neuromodulation in the neuroscience research ...
Circadian clocks respond to temperature changes over the calendar year, allowing organisms
to adjust their daily biological rhythms to optimize health and fitness. In Drosophila, seasonal adaptations are regulated by temperature-sensitive alternative ...
Childhood exposure to social disadvantage is a major risk factor for psychiatric disorders
and poor developmental, educational, and occupational outcomes, presumably because
adverse exposures alter the neurodevelopmental processes that contribute to risk ...
Gliomas are the most common malignant primary brain tumor and are often associated
with severe neurological deficits and mortality. Unlike many cancers, gliomas rarely
metastasize outside the brain, indicating a possible dependency on unique features
of ...
Perception is influenced by sensory stimulation, prior knowledge, and contextual cues,
which collectively contribute to the emergence of perceptual biases. However, the
precise neural mechanisms underlying these biases remain poorly understood. This study
...
Plant Biology
Haptophyta represents a major taxonomic group, with plastids derived from the primary
plastids of red algae. Here, we elucidated the cryoelectron microscopy structure of
the photosystem I–light-harvesting complex I (PSI–LHCI) supercomplex from the ...
Systems Biology
Motile organisms can expand into new territories and increase their fitness, while
nonmotile viruses usually depend on host migration to spread across long distances.
In general, faster host motility facilitates virus transmission. However, recent ...
Corrections
Cover image: Pictured are cattle herders in Ethiopia. A collection of articles in the Sustainability of Animal-Sourced Foods and Plant-Based Alternatives Special Feature explores the contributions of animal-sourced foods to human nutrition and health, the environmental impact of animal-sourced foods, and the potential of plant-based alternatives to help reduce animal-sourced food consumption. Together, the articles outline innovations and policies that could help transform global food systems to support human and environmental health across social and cultural contexts. See the Introduction to the Special Feature, e2400495121. Image credit: Asrat Ayalew (University of Bonn, Bonn, Germany).
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