Subscribe: PNAS - RSS feed of Early Edition articles
http://www.pnas.org/rss/ahead.xml
Added By: Feedage Forager Feedage Grade B rated
Language: English
Tags:
atmospheric  biology  cell  cells  development  gene  human  inflammation  large  model  physics  protein  proteins  role  sciences 
Rate this Feed
Rate this feedRate this feedRate this feedRate this feedRate this feed
Rate this feed 1 starRate this feed 2 starRate this feed 3 starRate this feed 4 starRate this feed 5 star

Comments (0)

Feed Details and Statistics Feed Statistics
Preview: PNAS - RSS feed of Early Edition articles

PNAS - RSS feed of Early Edition articles



Proceedings of the National Academy of Sciences RSS feed -- Early Edition



 



Future urban land expansion and implications for global croplands [Sustainability Science]

2016-12-27T09:51:19-08:00

Urban expansion often occurs on croplands. However, there is little scientific understanding of how global patterns of future urban expansion will affect the world’s cultivated areas. Here, we combine spatially explicit projections of urban expansion with datasets on global croplands and crop yields. Our results show that urban expansion will...



Global urban signatures of phenotypic change in animal and plant populations [Sustainability Science]

2017-01-03T08:47:11-08:00

Humans challenge the phenotypic, genetic, and cultural makeup of species by affecting the fitness landscapes on which they evolve. Recent studies show that cities might play a major role in contemporary evolution by accelerating phenotypic changes in wildlife, including animals, plants, fungi, and other organisms. Many studies of ecoevolutionary change...



Urban sustainability in an age of enduring inequalities: Advancing theory and ecometrics for the 21st-century city [Perspectives]

2017-01-06T12:50:12-08:00

The environmental fragility of cities under advanced urbanization has motivated extensive efforts to promote the sustainability of urban ecosystems and physical infrastructures. Less attention has been devoted to neighborhood inequalities and fissures in the civic infrastructure that potentially challenge social sustainability and the capacity of cities to collectively address environmental...



Global scenarios of urban density and its impacts on building energy use through 2050 [Sustainability Science]

2017-01-09T12:10:28-08:00

Although the scale of impending urbanization is well-acknowledged, we have a limited understanding of how urban forms will change and what their impact will be on building energy use. Using both top-down and bottom-up approaches and scenarios, we examine building energy use for heating and cooling. Globally, the energy use...



EHD2 restrains dynamics of caveolae by an ATP-dependent, membrane-bound, open conformation [Biochemistry]

2017-02-21T10:14:29-08:00

The EH-domain–containing protein 2 (EHD2) is a dynamin-related ATPase that confines caveolae to the cell surface by restricting the scission and subsequent endocytosis of these membrane pits. For this, EHD2 is thought to first bind to the membrane, then to oligomerize, and finally to detach, in a stringently regulated mechanistic...



Structural insights into the activation mechanism of dynamin-like EHD ATPases [Biophysics and Computational Biology]

2017-02-22T11:34:28-08:00

Eps15 (epidermal growth factor receptor pathway substrate 15)-homology domain containing proteins (EHDs) comprise a family of dynamin-related mechano-chemical ATPases involved in cellular membrane trafficking. Previous studies have revealed the structure of the EHD2 dimer, but the molecular mechanisms of membrane recruitment and assembly have remained obscure. Here, we determined the...



Genetic variation in chromosome Y regulates susceptibility to influenza A virus infection [Immunology and Inflammation]

2017-02-27T11:53:49-08:00

Males of many species, ranging from humans to insects, are more susceptible than females to parasitic, fungal, bacterial, and viral infections. One mechanism that has been proposed to account for this difference is the immunocompetence handicap model, which posits that the greater infectious disease burden in males is due to...



Correction for Hou et al., Homeostatic regulation of AMPA receptor expression at single hippocampal synapses [Corrections]

2017-03-06T11:56:43-08:00

NEUROSCIENCE Correction for “Homeostatic regulation of AMPA receptor expression at single hippocampal synapses,” by Qingming Hou, Dawei Zhang, Larissa Jarzylo, Richard L. Huganir, and Heng-Ye Man, which appeared in issue 2, January 15, 2008, of Proc Natl Acad Sci USA (105:775–780; first published January 3, 2008; 10.1073/pnas.0706447105). The authors note...



Correction for Koop, Crystals creeping out of cracks [Corrections]

2017-03-06T11:56:43-08:00

COMMENTARY Correction for “Crystals creeping out of cracks,” by Thomas Koop, which appeared in issue 5, January 31, 2017, of Proc Natl Acad Sci USA (114:797–799; first published January 19, 2017; 10.1073/pnas.1620084114). The author notes that panel E in Fig. 1 appeared incorrectly. The corrected figure and its legend appear...



Reconstitution of Saccharomyces cerevisiae DNA polymerase ϵ-dependent mismatch repair with purified proteins [Biochemistry]

2017-03-06T11:56:51-08:00

Mammalian and Saccharomyces cerevisiae mismatch repair (MMR) proteins catalyze two MMR reactions in vitro. In one, mispair binding by either the MutS homolog 2 (Msh2)–MutS homolog 6 (Msh6) or the Msh2–MutS homolog 3 (Msh3) stimulates 5′ to 3′ excision by exonuclease 1 (Exo1) from a single-strand break 5′ to the...



Common coding variant in SERPINA1 increases the risk for large artery stroke [Biochemistry]

2017-03-06T11:56:53-08:00

Large artery atherosclerotic stroke (LAS) shows substantial heritability not explained by previous genome-wide association studies. Here, we explore the role of coding variation in LAS by analyzing variants on the HumanExome BeadChip in a total of 3,127 cases and 9,778 controls from Europe, Australia, and South Asia. We report on...



Hybrid incompatibility caused by an epiallele [Genetics]

2017-03-07T09:43:16-08:00

Hybrid incompatibility resulting from deleterious gene combinations is thought to be an important step toward reproductive isolation and speciation. Here, we demonstrate involvement of a silent epiallele in hybrid incompatibility. In Arabidopsis thaliana accession Cvi-0, one of the two copies of a duplicated histidine biosynthesis gene, HISN6A, is mutated, making...



Monostable superrepellent materials [Physics]

2017-03-09T12:36:51-08:00

Superrepellency is an extreme situation where liquids stay at the tops of rough surfaces, in the so-called Cassie state. Owing to the dramatic reduction of solid/liquid contact, such states lead to many applications, such as antifouling, droplet manipulation, hydrodynamic slip, and self-cleaning. However, superrepellency is often destroyed by impalement transitions...



Topological knots and links in proteins [Applied Mathematics]

2017-03-09T12:36:52-08:00

Twenty years after their discovery, knots in proteins are now quite well understood. They are believed to be functionally advantageous and provide extra stability to protein chains. In this work, we go one step further and search for links—entangled structures, more complex than knots, which consist of several components. We...



Electron-hole asymmetry of the topological surface states in strained HgTe [Physics]

2017-03-09T12:36:52-08:00

Topological insulators are a new class of materials with an insulating bulk and topologically protected metallic surface states. Although it is widely assumed that these surface states display a Dirac-type dispersion that is symmetric above and below the Dirac point, this exact equivalence across the Fermi level has yet to...



Steady-state EB cap size fluctuations are determined by stochastic microtubule growth and maturation [Biophysics and Computational Biology]

2017-03-09T12:36:53-08:00

Growing microtubules are protected from depolymerization by the presence of a GTP or GDP/Pi cap. End-binding proteins of the EB1 family bind to the stabilizing cap, allowing monitoring of its size in real time. The cap size has been shown to correlate with instantaneous microtubule stability. Here we have quantitatively...



Multitrait successional forest dynamics enable diverse competitive coexistence [Ecology]

2017-03-10T12:17:47-08:00

To explain diversity in forests, niche theory must show how multiple plant species coexist while competing for the same resources. Although successional processes are widespread in forests, theoretical work has suggested that differentiation in successional strategy allows only a few species stably to coexist, including only a single shade tolerant....



Morphological features of IFN-{gamma}-stimulated mesenchymal stromal cells predict overall immunosuppressive capacity [Applied Biological Sciences]

2017-03-10T12:17:48-08:00

Human mesenchymal stromal cell (MSC) lines can vary significantly in their functional characteristics, and the effectiveness of MSC-based therapeutics may be realized by finding predictive features associated with MSC function. To identify features associated with immunosuppressive capacity in MSCs, we developed a robust in vitro assay that uses principal-component analysis...



Structure-guided SCHEMA recombination generates diverse chimeric channelrhodopsins [Biochemistry]

2017-03-10T12:17:48-08:00

Integral membrane proteins (MPs) are key engineering targets due to their critical roles in regulating cell function. In engineering MPs, it can be extremely challenging to retain membrane localization capability while changing other desired properties. We have used structure-guided SCHEMA recombination to create a large set of functionally diverse chimeras...



Exhaustion-associated regulatory regions in CD8+ tumor-infiltrating T cells [Immunology and Inflammation]

2017-03-10T12:17:48-08:00

T-cell exhaustion is a progressive loss of effector function and memory potential due to persistent antigen exposure, which occurs in chronic viral infections and cancer. Here we investigate the relation between gene expression and chromatin accessibility in CD8+ tumor-infiltrating lymphocytes (TILs) that recognize a model tumor antigen and have features...



Dynamic cross-correlations between entangled biofilaments as they diffuse [Applied Physical Sciences]

2017-03-10T12:17:49-08:00

Entanglement in polymer and biological physics involves a state in which linear interthreaded macromolecules in isotropic liquids diffuse in a spatially anisotropic manner beyond a characteristic mesoscopic time and length scale (tube diameter). The physical reason is that linear macromolecules become transiently localized in directions transverse to their backbone but...



Correction for Sethna et al., Insights into immune system development and function from mouse T-cell repertoires [Corrections]

2017-03-13T12:02:15-07:00

BIOPHYSICS AND COMPUTATIONAL BIOLOGY Correction for “Insights into immune system development and function from mouse T-cell repertoires,” by Zachary Sethna, Yuval Elhanati, Chrissy S. Dudgeon, Curtis G. Callan Jr., Arnold J. Levine, Thierry Mora, and Aleksandra M. Walczak, which appeared in issue 9, February 28, 2017, of Proc Natl Acad...



Ligand-induced allostery in the interaction of the Pseudomonas aeruginosa heme binding protein with heme oxygenase [Biophysics and Computational Biology]

2017-03-13T12:02:15-07:00

A heme-dependent conformational rearrangement of the C-terminal domain of heme binding protein (PhuS) is required for interaction with the iron-regulated heme oxygenase (HemO). Herein, we further investigate the underlying mechanism of this conformational rearrangement and its implications for heme transfer via site-directed mutagenesis, resonance Raman (RR), hydrogen–deuterium exchange MS (HDX-MS)...



AMPK blocks starvation-inducible transgenerational defects in Caenorhabditis elegans [Developmental Biology]

2017-03-13T12:02:15-07:00

Life history events, such as traumatic stress, illness, or starvation, can influence us through molecular changes that are recorded in a pattern of characteristic chromatin modifications. These modifications are often associated with adaptive adjustments in gene expression that can persist throughout the lifetime of the organism, or even span multiple...



Cathepsin S is the maȷor activator of the psoriasis-associated proinflammatory cytokine IL-36{gamma} [Immunology and Inflammation]

2017-03-13T12:02:15-07:00

The proinflammatory cytokine IL-36γ is highly expressed in epithelial cells and is a pivotal mediator of epithelial inflammation. In particular, IL-36γ is strongly associated with the inflammatory skin disease psoriasis. As with other IL-1 cytokines, IL-36γ is expressed as an inactive precursor and must be processed by specific proteases to...



BRASSINOSTEROID INSENSITIVE2 negatively regulates cellulose synthesis in Arabidopsis by phosphorylating cellulose synthase 1 [Plant Biology]

2017-03-13T12:02:16-07:00

The deposition of cellulose is a defining aspect of plant growth and development, but regulation of this process is poorly understood. Here, we demonstrate that the protein kinase BRASSINOSTEROID INSENSITIVE2 (BIN2), a key negative regulator of brassinosteroid (BR) signaling, can phosphorylate Arabidopsis cellulose synthase A1 (CESA1), a subunit of the...



Host immunity to Plasmodium falciparum and the assessment of emerging artemisinin resistance in a multinational cohort [Microbiology]

2017-03-13T12:02:16-07:00

Artemisinin-resistant falciparum malaria, defined by a slow-clearance phenotype and the presence of kelch13 mutants, has emerged in the Greater Mekong Subregion. Naturally acquired immunity to malaria clears parasites independent of antimalarial drugs. We hypothesized that between- and within-population variations in host immunity influence parasite clearance after artemisinin treatment and the...



Effect of material flexibility on the thermodynamics and kinetics of hydrophobically induced evaporation of water [Applied Physical Sciences]

2017-03-13T12:02:16-07:00

The evaporation of water induced by confinement between hydrophobic surfaces has received much attention due to its suggested functional role in numerous biophysical phenomena and its importance as a general mechanism of hydrophobic self-assembly. Although much progress has been made in understanding the basic physics of hydrophobically induced evaporation, a...



Deep melting reveals liquid structural memory and anomalous ferromagnetism in bismuth [Physics]

2017-03-13T12:02:16-07:00

As an archetypal semimetal with complex and anisotropic Fermi surface and unusual electric properties (e.g., high electrical resistance, large magnetoresistance, and giant Hall effect), bismuth (Bi) has played a critical role in metal physics. In general, Bi displays diamagnetism with a high volumetric susceptibility (∼10−4). Here, we report unusual ferromagnetism...



Osmolality/salinity-responsive enhancers (OSREs) control induction of osmoprotective genes in euryhaline fish [Evolution]

2017-03-13T12:02:17-07:00

Fish respond to salinity stress by transcriptional induction of many genes, but the mechanism of their osmotic regulation is unknown. We developed a reporter assay using cells derived from the brain of the tilapia Oreochromis mossambicus (OmB cells) to identify osmolality/salinity-responsive enhancers (OSREs) in the genes of O. mossambicus. Genomic...



Toll pathway is required for wound-induced expression of barrier repair genes in the Drosophila epidermis [Developmental Biology]

2017-03-13T12:02:17-07:00

The epidermis serves as a protective barrier in animals. After epidermal injury, barrier repair requires activation of many wound response genes in epidermal cells surrounding wound sites. Two such genes in Drosophila encode the enzymes dopa decarboxylase (Ddc) and tyrosine hydroxylase (ple). In this paper we explore the involvement of...



Large-scale identification of coevolution signals across homo-oligomeric protein interfaces by direct coupling analysis [Biophysics and Computational Biology]

2017-03-13T12:02:17-07:00

Proteins have evolved to perform diverse cellular functions, from serving as reaction catalysts to coordinating cellular propagation and development. Frequently, proteins do not exert their full potential as monomers but rather undergo concerted interactions as either homo-oligomers or with other proteins as hetero-oligomers. The experimental study of such protein complexes...



Correction for Nielsen et al., Opinion: Gender diversity leads to better science [Corrections]

2017-03-13T12:02:18-07:00

OPINION Correction for “Opinion: Gender diversity leads to better science,” by Mathias Wullum Nielsen, Sharla Alegria, Love Börjeson, Henry Etzkowitz, Holly J. Falk-Krzesinski, Aparna Joshi, Erin Leahey, Laurel Smith-Doerr, Anita Williams Woolley, and Londa Schiebinger, which appeared in issue 8, February 21, 2017, of Proc Natl Acad Sci USA (114:1740–1742;...



Dynamic neural architecture for social knowledge retrieval [Neuroscience]

2017-03-13T12:02:18-07:00

Social behavior is often shaped by the rich storehouse of biographical information that we hold for other people. In our daily life, we rapidly and flexibly retrieve a host of biographical details about individuals in our social network, which often guide our decisions as we navigate complex social interactions. Even...



In vivo diagnostics of early abiotic plant stress response via Raman spectroscopy [Physics]

2017-03-13T12:02:18-07:00

Development of a phenotyping platform capable of noninvasive biochemical sensing could offer researchers, breeders, and producers a tool for precise response detection. In particular, the ability to measure plant stress in vivo responses is becoming increasingly important. In this work, a Raman spectroscopic technique is developed for high-throughput stress phenotyping...



Intensified agriculture favors evolved resistance to biological control [Agricultural Sciences]

2017-03-13T12:02:18-07:00

Increased regulation of chemical pesticides and rapid evolution of pesticide resistance have increased calls for sustainable pest management. Biological control offers sustainable pest suppression, partly because evolution of resistance to predators and parasitoids is prevented by several factors (e.g., spatial or temporal refuges from attacks, reciprocal evolution by control agents,...



Storage and release of hydrogen cyanide in a chelicerate (Oribatula tibialis) [Chemistry]

2017-03-13T12:02:19-07:00

Cyanogenesis denotes a chemical defensive strategy where hydrogen cyanide (HCN, hydrocyanic or prussic acid) is produced, stored, and released toward an attacking enemy. The high toxicity and volatility of HCN requires both chemical stabilization for storage and prevention of accidental self-poisoning. The few known cyanogenic animals are exclusively mandibulate arthropods...



Eradicating catastrophic collapse in interdependent networks via reinforced nodes [Applied Physical Sciences]

2017-03-13T12:02:19-07:00

In interdependent networks, it is usually assumed, based on percolation theory, that nodes become nonfunctional if they lose connection to the network giant component. However, in reality, some nodes, equipped with alternative resources, together with their connected neighbors can still be functioning after disconnected from the giant component. Here, we...



Conserved role for Gga proteins in phosphatidylinositol 4-kinase localization to the trans-Golgi network [Cell Biology]

2017-03-13T12:02:08-07:00

Phosphoinositides serve as key membrane determinants for assembly of clathrin coat proteins that drive formation of clathrin-coated vesicles. At the trans-Golgi network (TGN), phosphatidylinositol 4-phosphate (PtdIns4P) plays important roles in recruitment of two major clathrin adaptors, Gga (Golgi-localized, gamma-adaptin ear homology, Arf-binding) proteins and the AP-1 (assembly protein-1) complex. The...



Specific deletion of LKB1/Stk11 in the Mullerian duct mesenchyme drives hyperplasia of the periurethral stroma and tumorigenesis in male mice [Developmental Biology]

2017-03-13T12:02:08-07:00

Nearly all older men will experience lower urinary tract symptoms associated with benign prostatic hyperplasia (BPH), the etiology of which is not well understood. We have generated Stk11CKO mice by conditional deletion of the liver kinase B1 (LKB1) tumor suppressor gene, Stk11 (serine threonine kinase 11), in the fetal Müllerian...



Injury-stimulated and self-restrained BMP signaling dynamically regulates stem cell pool size during Drosophila midgut regeneration [Developmental Biology]

2017-03-13T12:02:09-07:00

Many adult organs rely on resident stem cells to maintain homeostasis. Upon injury, stem cells increase proliferation, followed by lineage differentiation to replenish damaged cells. Whether stem cells also change division mode to transiently increase their population size as part of a regenerative program and, if so, what the underlying...



Phosphorylation-induced conformational dynamics in an intrinsically disordered protein and potential role in phenotypic heterogeneity [Biophysics and Computational Biology]

2017-03-13T12:02:09-07:00

Intrinsically disordered proteins (IDPs) that lack a unique 3D structure and comprise a large fraction of the human proteome play important roles in numerous cellular functions. Prostate-Associated Gene 4 (PAGE4) is an IDP that acts as a potentiator of the Activator Protein-1 (AP-1) transcription factor. Homeodomain-Interacting Protein Kinase 1 (HIPK1)...



George Klein: 1925-2016 [Retrospectives]

2017-03-13T12:02:09-07:00

George Klein, famous cancer biologist and acclaimed writer on matters of science, human responsibility, and the human condition, decorated by innumerable awards, honorary doctorates and other honors, elected member of this Academy and many other learned societies, including the Royal Swedish Academy of Sciences and the American Philosophical Society, and...



Sediment supply controls equilibrium channel geometry in gravel rivers [Earth, Atmospheric, and Planetary Sciences]

2017-03-13T12:02:09-07:00

In many gravel-bedded rivers, floods that fill the channel banks create just enough shear stress to move the median-sized gravel particles on the bed surface (D50). Because this observation is common and is supported by theory, the coincidence of bankfull flow and the incipient motion of D50 has become a...



New Middle Pleistocene hominin cranium from Gruta da Aroeira (Portugal) [Anthropology]

2017-03-13T12:02:09-07:00

The Middle Pleistocene is a crucial time period for studying human evolution in Europe, because it marks the appearance of both fossil hominins ancestral to the later Neandertals and the Acheulean technology. Nevertheless, European sites containing well-dated human remains associated with an Acheulean toolkit remain scarce. The earliest European hominin...



Photocyclic behavior of rhodopsin induced by an atypical isomerization mechanism [Biochemistry]

2017-03-13T12:02:10-07:00

Vertebrate rhodopsin (Rh) contains 11-cis-retinal as a chromophore to convert light energy into visual signals. On absorption of light, 11-cis-retinal is isomerized to all-trans-retinal, constituting a one-way reaction that activates transducin (Gt) followed by chromophore release. Here we report that bovine Rh, regenerated instead with a six-carbon-ring retinal chromophore featuring...



Selective dietary supplementation in early postpartum is associated with high resilience against depressed mood [Medical Sciences]

2017-03-13T12:02:10-07:00

Medical research is moving toward prevention strategies during prodromal states. Postpartum blues (PPB) is often a prodromal state for postpartum depression (PPD), with severe PPB strongly associated with an elevated risk for PPD. The most common complication of childbearing, PPD has a prevalence of 13%, but there are no widespread...



B vitamins attenuate the epigenetic effects of ambient fine particles in a pilot human intervention trial [Medical Sciences]

2017-03-13T12:02:10-07:00

Acute exposure to fine particle (PM2.5) induces DNA methylation changes implicated in inflammation and oxidative stress. We conducted a crossover trial to determine whether B-vitamin supplementation averts such changes. Ten healthy adults blindly received a 2-h, controlled-exposure experiment to sham under placebo, PM2.5 (250 μg/m3) under placebo, and PM2.5 (250...



Electron transfer between anatase TiO2 and an O2 molecule directly observed by atomic force microscopy [Chemistry]

2017-03-13T12:02:11-07:00

Activation of molecular oxygen is a key step in converting fuels into energy, but there is precious little experimental insight into how the process proceeds at the atomic scale. Here, we show that a combined atomic force microscopy/scanning tunneling microscopy (AFM/STM) experiment can both distinguish neutral O2 molecules in the...



Stability of Ar(H2)2 to 358 GPa [Physics]

2017-03-13T12:02:11-07:00

“Chemical precompression” through introducing impurity atoms into hydrogen has been proposed as a method to facilitate metallization of hydrogen under external pressure. Here we selected Ar(H2)2, a hydrogen-rich compound with molecular hydrogen, to explore the effect of “doping” on the intermolecular interaction of H2 molecules and metallization at ultrahigh pressure....



Modulating IgG effector function by Fc glycan engineering [Immunology and Inflammation]

2017-03-13T12:02:11-07:00

IgG antibodies contain a conserved N-glycosylation site on the Fc domain to which a complex, biantennary glycan is attached. The fine structures of this glycan modulate antibody effector functions by affecting the binding affinity of the Fc to diverse Fc receptor family members. For example, core fucosylation significantly decreases antibody-dependent...



Phytosphingosine degradation pathway includes fatty acid {alpha}-oxidation reactions in the endoplasmic reticulum [Biochemistry]

2017-03-13T12:02:11-07:00

Although normal fatty acids (FAs) are degraded via β-oxidation, unusual FAs such as 2-hydroxy (2-OH) FAs and 3-methyl-branched FAs are degraded via α-oxidation. Phytosphingosine (PHS) is one of the long-chain bases (the sphingolipid components) and exists in specific tissues, including the epidermis and small intestine in mammals. In the degradation...



Gentamicin B1 is a minor gentamicin component with major nonsense mutation suppression activity [Genetics]

2017-03-13T12:02:12-07:00

Nonsense mutations underlie about 10% of rare genetic disease cases. They introduce a premature termination codon (PTC) and prevent the formation of full-length protein. Pharmaceutical gentamicin, a mixture of several related aminoglycosides, is a frequently used antibiotic in humans that can induce PTC readthrough and suppress nonsense mutations at high...



Fossil and genomic evidence constrains the timing of bison arrival in North America [Earth, Atmospheric, and Planetary Sciences]

2017-03-13T12:02:12-07:00

The arrival of bison in North America marks one of the most successful large-mammal dispersals from Asia within the last million years, yet the timing and nature of this event remain poorly determined. Here, we used a combined paleontological and paleogenomic approach to provide a robust timeline for the entry...



Biological regulation of atmospheric chemistry en route to planetary oxygenation [Earth, Atmospheric, and Planetary Sciences]

2017-03-13T12:02:12-07:00

Emerging evidence suggests that atmospheric oxygen may have varied before rising irreversibly ∼2.4 billion years ago, during the Great Oxidation Event (GOE). Significantly, however, pre-GOE atmospheric aberrations toward more reducing conditions—featuring a methane-derived organic-haze—have recently been suggested, yet their occurrence, causes, and significance remain underexplored. To examine the role of...



Patterns of coordinated cortical remodeling during adolescence and their associations with functional specialization and evolutionary expansion [Neuroscience]

2017-03-13T12:02:12-07:00

During adolescence, the human cortex undergoes substantial remodeling to support a rapid expansion of behavioral repertoire. Accurately quantifying these changes is a prerequisite for understanding normal brain development, as well as the neuropsychiatric disorders that emerge in this vulnerable period. Past accounts have demonstrated substantial regional heterogeneity in patterns of...



Pacific North American circulation pattern links external forcing and North American hydroclimatic change over the past millennium [Earth, Atmospheric, and Planetary Sciences]

2017-03-13T12:02:13-07:00

Land and sea surface temperatures, precipitation, and storm tracks in North America and the North Pacific are controlled to a large degree by atmospheric variability associated with the Pacific North American (PNA) pattern. The modern instrumental record indicates a trend toward a positive PNA phase in recent decades, which has...



Naturally occurring fluorescence in frogs [Ecology]

2017-03-13T12:02:13-07:00

Fluorescence, the absorption of short-wavelength electromagnetic radiation reemitted at longer wavelengths, has been suggested to play several biological roles in metazoans. This phenomenon is uncommon in tetrapods, being restricted mostly to parrots and marine turtles. We report fluorescence in amphibians, in the tree frog Hypsiboas punctatus, showing that fluorescence in...



Wettability effect on nanoconfined water flow [Engineering]

2017-03-13T12:02:13-07:00

Understanding and controlling the flow of water confined in nanopores has tremendous implications in theoretical studies and industrial applications. Here, we propose a simple model for the confined water flow based on the concept of effective slip, which is a linear sum of true slip, depending on a contact angle,...



Persistence of the mitochondrial permeability transition in the absence of subunit c of human ATP synthase [Biochemistry]

2017-03-13T12:02:13-07:00

The permeability transition in human mitochondria refers to the opening of a nonspecific channel, known as the permeability transition pore (PTP), in the inner membrane. Opening can be triggered by calcium ions, leading to swelling of the organelle, disruption of the inner membrane, and ATP synthesis, followed by cell death....



Cross-cousin marriage among the Yanomamo shows evidence of parent-offspring conflict and mate competition between brothers [Anthropology]

2017-03-13T12:02:14-07:00

Marriage in many traditional societies often concerns the institutionalized exchange of reproductive partners among groups of kin. Such exchanges most often involve cross-cousins—marriage with the child of a parent’s opposite-sex sibling—but it is unclear who benefits from these exchanges. Here we analyze the fitness consequences of marrying relatives among the...



Flowering phenology shifts in response to biodiversity loss [Ecology]

2017-03-13T12:02:14-07:00

Observational studies and experimental evidence agree that rising global temperatures have altered plant phenology—the timing of life events, such as flowering, germination, and leaf-out. Other large-scale global environmental changes, such as nitrogen deposition and altered precipitation regimes, have also been linked to changes in flowering times. Despite our increased understanding...



Transcriptional landscape of the human cell cycle [Genetics]

2017-03-13T12:02:14-07:00

Steady-state gene expression across the cell cycle has been studied extensively. However, transcriptional gene regulation and the dynamics of histone modification at different cell-cycle stages are largely unknown. By applying a combination of global nuclear run-on sequencing (GRO-seq), RNA sequencing (RNA-seq), and histone-modification Chip sequencing (ChIP-seq), we depicted a comprehensive...



Volatile secondary metabolites as aposematic olfactory signals and defensive weapons in aquatic environments [Chemistry]

2017-03-13T12:02:15-07:00

Olfaction is considered a distance sense; hence, aquatic olfaction is thought to be mediated only by molecules dissolved in water. Here, we challenge this view by showing that shrimp and fish can recognize the presence of hydrophobic olfactory cues by a “tactile” form of chemoreception. We found that odiferous furanosesquiterpenes...



Coarse graining from variationally enhanced sampling applied to the Ginzburg-Landau model [Physics]

2017-03-14T08:11:04-07:00

A powerful way to deal with a complex system is to build a coarse-grained model capable of catching its main physical features, while being computationally affordable. Inevitably, such coarse-grained models introduce a set of phenomenological parameters, which are often not easily deducible from the underlying atomistic system. We present a...



Distinct recognition of complement iC3b by integrins {alpha}X{beta}2 and {alpha}M{beta}2 [Biochemistry]

2017-03-14T08:10:58-07:00

Recognition by the leukocyte integrins αXβ2 and αMβ2 of complement iC3b-opsonized targets is essential for effector functions including phagocytosis. The integrin-binding sites on iC3b remain incompletely characterized. Here, we describe negative-stain electron microscopy and biochemical studies of αXβ2 and αMβ2 in complex with iC3b. Despite high homology, the two integrins...



Noncanonical role of Arabidopsis COP1/SPA complex in repressing BIN2-mediated PIF3 phosphorylation and degradation in darkness [Plant Biology]

2017-03-14T08:10:58-07:00

The E3 ligase CONSTITUTIVELY PHOTOMORPHOGENIC 1 (COP1) has been known to mediate key signaling factors for degradation via the ubiquitin/26S proteasome pathway in both plants and animals. Here, we report a noncanonical function of Arabidopsis COP1, the central repressor of photomorphogenesis, in the form of a COP1/ SUPPRESSOR of phyA-105...



Small molecule selectively suppresses MYC transcription in cancer cells [Medical Sciences]

2017-03-14T08:10:58-07:00

Stauprimide is a staurosporine analog that promotes embryonic stem cell (ESC) differentiation by inhibiting nuclear localization of the MYC transcription factor NME2, which in turn results in down-regulation of MYC transcription. Given the critical role the oncogene MYC plays in tumor initiation and maintenance, we explored the potential of stauprimide...



Receptor Mincle promotes skin allergies and is capable of recognizing cholesterol sulfate [Immunology and Inflammation]

2017-03-14T08:10:58-07:00

Sterile (noninfected) inflammation underlies the pathogenesis of many widespread diseases, such as allergies and autoimmune diseases. The evolutionarily conserved innate immune system is considered to play a key role in tissue injury recognition and the subsequent development of sterile inflammation; however, the underlying molecular mechanisms are not yet completely understood....



Diagnosis of prostate cancer by desorption electrospray ionization mass spectrometric imaging of small metabolites and lipids [Chemistry]

2017-03-14T08:10:59-07:00

Accurate identification of prostate cancer in frozen sections at the time of surgery can be challenging, limiting the surgeon’s ability to best determine resection margins during prostatectomy. We performed desorption electrospray ionization mass spectrometry imaging (DESI-MSI) on 54 banked human cancerous and normal prostate tissue specimens to investigate the spatial...



Loss of LMOD1 impairs smooth muscle cytocontractility and causes megacystis microcolon intestinal hypoperistalsis syndrome in humans and mice [Genetics]

2017-03-14T08:10:59-07:00

Megacystis microcolon intestinal hypoperistalsis syndrome (MMIHS) is a congenital visceral myopathy characterized by severe dilation of the urinary bladder and defective intestinal motility. The genetic basis of MMIHS has been ascribed to spontaneous and autosomal dominant mutations in actin gamma 2 (ACTG2), a smooth muscle contractile gene. However, evidence suggesting...



Inhibition of atherogenesis by the COP9 signalosome subunit 5 in vivo [Immunology and Inflammation]

2017-03-14T08:10:59-07:00

Constitutive photomorphogenesis 9 (COP9) signalosome 5 (CSN5), an isopeptidase that removes neural precursor cell-expressed, developmentally down-regulated 8 (NEDD8) moieties from cullins (thus termed “deNEDDylase”) and a subunit of the cullin-RING E3 ligase-regulating COP9 signalosome complex, attenuates proinflammatory NF-κB signaling. We previously showed that CSN5 is up-regulated in human atherosclerotic arteries....



Multisite aggregation of p53 and implications for drug rescue [Biochemistry]

2017-03-14T08:11:00-07:00

Protein aggregation is involved in many diseases. Often, a unique aggregation-prone sequence polymerizes to form regular fibrils. Many oncogenic mutants of the tumor suppressor p53 rapidly aggregate but form amorphous fibrils. A peptide surrounding Ile254 is proposed to be the aggregation-driving sequence in cells. We identified several different aggregating sites...



Fission yeast myosin I facilitates PI(4,5)P2-mediated anchoring of cytoplasmic dynein to the cortex [Cell Biology]

2017-03-14T08:11:01-07:00

Several key processes in the cell, such as vesicle transport and spindle positioning, are mediated by the motor protein cytoplasmic dynein, which produces force on the microtubule. For the functions that require movement of the centrosome and the associated nuclear material, dynein needs to have a stable attachment at the...



Hormone and receptor interplay in the regulation of mosquito lipid metabolism [Developmental Biology]

2017-03-14T08:11:01-07:00

Mosquitoes transmit devastating human diseases because they need vertebrate blood for egg development. Metabolism in female mosquitoes is tightly coupled with blood meal-mediated reproduction, which requires an extremely high level of energy consumption. Functional analysis has shown that major genes encoding for enzymes involved in lipid metabolism (LM) in the...



Bacterial proteostasis balances energy and chaperone utilization efficiently [Biophysics and Computational Biology]

2017-03-14T08:11:01-07:00

Chaperones are protein complexes that help to fold and disaggregate a cell’s proteins. It is not understood how four major chaperone systems of Escherichia coli work together in proteostasis: the recognition, sorting, folding, and disaggregating of the cell’s many different proteins. Here, we model this machine. We combine extensive data...



Tunable moire bands and strong correlations in small-twist-angle bilayer graphene [Physics]

2017-03-14T08:11:02-07:00

According to electronic structure theory, bilayer graphene is expected to have anomalous electronic properties when it has long-period moiré patterns produced by small misalignments between its individual layer honeycomb lattices. We have realized bilayer graphene moiré crystals with accurately controlled twist angles smaller than 1° and studied their properties using...



Mouse cytomegalovirus M36 and M45 death suppressors cooperate to prevent inflammation resulting from antiviral programmed cell death pathways [Microbiology]

2017-03-14T08:11:02-07:00

The complex interplay between caspase-8 and receptor-interacting protein (RIP) kinase RIP 3 (RIPK3) driving extrinsic apoptosis and necroptosis is not fully understood. Murine cytomegalovirus triggers both apoptosis and necroptosis in infected cells; however, encoded inhibitors of caspase-8 activity (M36) and RIP3 signaling (M45) suppress these antiviral responses. Here, we report...



Optimal run-and-tumble-based transportation of a Janus particle with active steering [Physics]

2017-03-14T08:11:02-07:00

Although making artificial micrometric swimmers has been made possible by using various propulsion mechanisms, guiding their motion in the presence of thermal fluctuations still remains a great challenge. Such a task is essential in biological systems, which present a number of intriguing solutions that are robust against noisy environmental conditions...



Computational investigation of surface freezing in a molecular model of water [Applied Physical Sciences]

2017-03-14T08:11:03-07:00

Water freezes in a wide variety of low-temperature environments, from meteors and atmospheric clouds to soil and biological cells. In nature, ice usually nucleates at or near interfaces, because homogenous nucleation in the bulk can only be observed at deep supercoolings. Although the effect of proximal surfaces on freezing has...



Parasitophorous vacuole poration precedes its rupture and rapid host erythrocyte cytoskeleton collapse in Plasmodium falciparum egress [Cell Biology]

2017-03-14T08:11:03-07:00

In the asexual blood stages of malarial infection, merozoites invade erythrocytes and replicate within a parasitophorous vacuole to form daughter cells that eventually exit (egress) by sequential rupture of the vacuole and erythrocyte membranes. The current model is that PKG, a malarial cGMP-dependent protein kinase, triggers egress, activating malarial proteases...



Overcoming catastrophic forgetting in neural networks [Applied Mathematics]

2017-03-14T08:11:03-07:00

The ability to learn tasks in a sequential fashion is crucial to the development of artificial intelligence. Until now neural networks have not been capable of this and it has been widely thought that catastrophic forgetting is an inevitable feature of connectionist models. We show that it is possible to...



QnAs with Marcia McNutt [QnAs]

2017-03-15T12:25:48-07:00

When geophysicist Marcia McNutt learned that she had been nominated to stand for election as president of the National Academy of Sciences (NAS), she modestly pointed out to the selection committee that, although she felt honored, she was surprised to be chosen from a pool of what were surely far...



Deep-sea coral evidence for lower Southern Ocean surface nitrate concentrations during the last ice age [Earth, Atmospheric, and Planetary Sciences]

2017-03-15T12:25:48-07:00

The Southern Ocean regulates the ocean’s biological sequestration of CO2 and is widely suspected to underpin much of the ice age decline in atmospheric CO2 concentration, but the specific changes in the region are debated. Although more complete drawdown of surface nutrients by phytoplankton during the ice ages is supported...



Quantifying the driving factors for language shift in a bilingual region [Computer Sciences]

2017-03-15T12:25:49-07:00

Many of the world’s around 6,000 languages are in danger of disappearing as people give up use of a minority language in favor of the majority language in a process called language shift. Language shift can be monitored on a large scale through the use of mathematical models by way...



Reply to Yamini and Nestorovich: Alternate clamped states of the anthrax toxin protective antigen channel [Letters (Online Only)]

2017-03-15T12:58:11-07:00

Yamini and Nestorovich (1) recently commented on our article in PNAS (2). In their letter, they weigh in on two issues with the previously reported (3, 4) alternate conductance substate of the protective antigen (PA) translocase channel. The first point they raised was whether the conductance substate was a clamped...



Relevance of the alternate conductance states of anthrax toxin channel [Letters (Online Only)]

2017-03-15T13:28:47-07:00

In their recent article in PNAS, Das and Krantz (1) attempt to relate the previously described (2, 3) alternate conductance substate of the anthrax toxin protective antigen (PA63) channel to the allosteric helix compression model (4). Although we do not intend to discuss the differences between this model and the...



Can self-awareness be taught? Monkeys pass the mirror test—again [Commentaries]

2017-03-16T12:12:57-07:00

“Mirrors,” she said, “are never to be trusted.” Neil Gaiman, Coraline The ability to recognize oneself in the mirror is often held as evidence of self-awareness. However, children under the age of 2 y and most animals do not behave as if their mirrored reflection represents their own face or...



Common nonmutational NOTCH1 activation in chronic lymphocytic leukemia [Medical Sciences]

2017-03-17T11:41:48-07:00

Activating mutations of NOTCH1 (a well-known oncogene in T-cell acute lymphoblastic leukemia) are present in ∼4–13% of chronic lymphocytic leukemia (CLL) cases, where they are associated with disease progression and chemorefractoriness. However, the specific role of NOTCH1 in leukemogenesis remains to be established. Here, we report that the active intracellular...



Eliciting probabilistic expectations: Collaborations between psychologists and economists [Perspectives]

2017-03-07T09:43:17-08:00

We describe two collaborations in which psychologists and economists provided essential support on foundational projects in major research programs. One project involved eliciting adolescents’ expectations regarding significant future life events affecting their psychological and economic development. The second project involved eliciting consumers’ expectations regarding inflation, a potentially vital input to...



Real space renormalization group theory of disordered models of glasses [Applied Physical Sciences]

2017-02-21T10:14:37-08:00

We develop a real space renormalization group analysis of disordered models of glasses, in particular of the spin models at the origin of the random first-order transition theory. We find three fixed points, respectively, associated with the liquid state, with the critical behavior, and with the glass state. The latter...



Manipulating molecules with quantum light [Commentaries]

2017-03-16T12:12:57-07:00

It was first realized by Purcell (1) that the spontaneous emission rate of a quantum system can be enhanced or suppressed by placing it in a resonant radiofrequency cavity. Spontaneous emission as it was first theoretically described by Einstein (2) is not a pure property of matter. It is described...



Data-based modeling of drug penetration relates human skin barrier function to the interplay of diffusivity and free-energy profiles [Applied Physical Sciences]

2017-03-20T12:07:00-07:00

Based on experimental concentration depth profiles of the antiinflammatory drug dexamethasone in human skin, we model the time-dependent drug penetration by the 1D general diffusion equation that accounts for spatial variations in the diffusivity and free energy. For this, we numerically invert the diffusion equation and thereby obtain the diffusivity...



Activin-A co-opts IRF4 and AhR signaling to induce human regulatory T cells that restrain asthmatic responses [Immunology and Inflammation]

2017-03-20T12:07:01-07:00

Type 1 regulatory T (Tr1) cells play a pivotal role in restraining human T-cell responses toward environmental allergens and protecting against allergic diseases. Still, the precise molecular cues that underlie their transcriptional and functional specification remain elusive. Here, we show that the cytokine activin-A instructs the generation of CD4+ T...



Allele-specific non-CG DNA methylation marks domains of active chromatin in female mouse brain [Genetics]

2017-03-20T12:07:01-07:00

DNA methylation at gene promoters in a CG context is associated with transcriptional repression, including at genes silenced on the inactive X chromosome in females. Non-CG methylation (mCH) is a distinct feature of the neuronal epigenome that is differentially distributed between males and females on the X chromosome. However, little...



Triad of human cellular proteins, IRF2, FAM111A, and RFC3, restrict replication of orthopoxvirus SPI-1 host-range mutants [Microbiology]

2017-03-20T12:07:01-07:00

Viruses and their hosts can reach balanced states of evolution ensuring mutual survival, which makes it difficult to appreciate the underlying dynamics. To uncover hidden interactions, virus mutants that have lost defense genes may be used. Deletion of the gene that encodes serine protease inhibitor 1 (SPI-1) of rabbitpox virus...



High-capacity, low-tortuosity, and channel-guided lithium metal anode [Engineering]

2017-03-20T12:07:01-07:00

Lithium metal anode with the highest capacity and lowest anode potential is extremely attractive to battery technologies, but infinite volume change during the Li stripping/plating process results in cracks and fractures of the solid electrolyte interphase, low Coulombic efficiency, and dendritic growth of Li. Here, we use a carbonized wood...



Meta-assessment of bias in science [Medical Sciences]

2017-03-20T12:07:02-07:00

Numerous biases are believed to affect the scientific literature, but their actual prevalence across disciplines is unknown. To gain a comprehensive picture of the potential imprint of bias in science, we probed for the most commonly postulated bias-related patterns and risk factors, in a large random sample of meta-analyses taken...



Effectiveness of UNAIDS targets and HIV vaccination across 127 countries [Population Biology]

2017-03-20T12:07:02-07:00

The HIV pandemic continues to impose enormous morbidity, mortality, and economic burdens across the globe. Simultaneously, innovations in antiretroviral therapy, diagnostic approaches, and vaccine development are providing novel tools for treatment-as-prevention and prophylaxis. We developed a mathematical model to evaluate the added benefit of an HIV vaccine in the context...



Decoupling local mechanics from large-scale structure in modular metamaterials [Engineering]

2017-03-20T12:07:02-07:00

A defining feature of mechanical metamaterials is that their properties are determined by the organization of internal structure instead of the raw fabrication materials. This shift of attention to engineering internal degrees of freedom has coaxed relatively simple materials into exhibiting a wide range of remarkable mechanical properties. For practical...