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



 



Aqueous phosphorene dispersions [Applied Physical Sciences]

2016-04-18T11:52:20-07:00

Understanding and exploiting the remarkable optical and electronic properties of phosphorene require mass production methods that avoid chemical degradation. Although solution-based strategies have been developed for scalable exfoliation of black phosphorus, these techniques have thus far used anhydrous organic solvents in an effort to minimize exposure to known oxidants, but...



Magnetite pollution particles in the human brain [Neuroscience]

2016-09-06T08:36:22-07:00

Biologically formed nanoparticles of the strongly magnetic mineral, magnetite, were first detected in the human brain over 20 y ago [Kirschvink JL, Kobayashi-Kirschvink A, Woodford BJ (1992) Proc Natl Acad Sci USA 89(16):7683–7687]. Magnetite can have potentially large impacts on the brain due to its unique combination of redox activity,...



Measuring the neuroanatomical signature of a trait [Neuroscience]

2016-09-09T11:37:43-07:00

Complex physiological and behavioral traits, including neurological and psychiatric disorders, often associate with distributed anatomical variation. This paper introduces a global metric, called morphometricity, as a measure of the anatomical signature of different traits. Morphometricity is defined as the proportion of phenotypic variation that can be explained by macroscopic brain...



Men{#x2019}s status and reproductive success [Anthropology]

2016-09-06T08:36:23-07:00

Social status motivates much of human behavior. However, status may have been a relatively weak target of selection for much of human evolution if ancestral foragers tended to be more egalitarian. We test the “egalitarianism hypothesis” that status has a significantly smaller effect on reproductive success (RS) in foragers compared...



Acetyl-carnitine and the brain [Letters (Online Only)]

2016-09-12T13:36:33-07:00

Arduini et al. raise interesting issues related to mechanisms involving carnitine (1). The authors ask whether there is a free-carnitine deficiency in Flinders Sensitive Line rats (FSL) (2) and, more broadly, raise the question of whether the deficiency of acetyl-l-carnitine (LAC) occurs systemically or in the brain in FSL (1)....



Antidepressant effect of acetyl-carnitine [Letters (Online Only)]

2016-09-12T13:54:46-07:00

Bigio et al. (1) report that oral administration of acetyl-l-carnitine (LAC) results in antidepressant-like effects along with an improvement of energy metabolism in the ventral dentate gyrus in endogenously depressed Flinders Sensitive Line rats (FSL). FSL also show a significant reduction of LAC in the hippocampus and prefrontal cortex compared...



E4F1-mediated regulation of PDH in skin [Physiology]

2016-09-12T12:02:25-07:00

The multifunctional protein E4 transcription factor 1 (E4F1) is an essential regulator of epidermal stem cell (ESC) maintenance. Here, we found that E4F1 transcriptionally regulates a metabolic program involved in pyruvate metabolism that is required to maintain skin homeostasis. E4F1 deficiency in basal keratinocytes resulted in deregulated expression of dihydrolipoamide...



Dual role in nutritional quality and yield [Agricultural Sciences]

2016-09-12T12:02:25-07:00

The maize endosperm-specific transcription factors opaque2 (O2) and prolamine-box binding factor (PBF) regulate storage protein zein genes. We show that they also control starch synthesis. The starch content in the PbfRNAi and o2 mutants was reduced by ∼5% and 11%, respectively, compared with normal genotypes. In the double-mutant PbfRNAi;o2, starch...



Connectivity rescues genetic diversity [Ecology]

2016-09-12T12:02:26-07:00

Demographic bottlenecks that occur when populations fluctuate in size erode genetic diversity, but that diversity can be recovered through immigration. Connectivity among populations and habitat patches in the landscape enhances immigration and should in turn facilitate recovery of genetic diversity after a sudden reduction in population size. For the conservation...



Selective NP delivery to cancer over normal cells [Engineering]

2016-09-12T12:02:26-07:00

Conventional chemotherapeutics nonselectively kill all rapidly dividing cells, which produces numerous side effects. To address this challenge, we report the discovery of functional polyesters that are capable of delivering siRNA drugs selectively to lung cancer cells and not to normal lung cells. Selective polyplex nanoparticles (NPs) were identified by high-throughput...



Regulation of bacterial F1-ATPase [Biochemistry]

2016-09-12T12:02:26-07:00

The crystal structure has been determined of the F1-catalytic domain of the F-ATPase from Caldalkalibacillus thermarum, which hydrolyzes adenosine triphosphate (ATP) poorly. It is very similar to those of active mitochondrial and bacterial F1-ATPases. In the F-ATPase from Geobacillus stearothermophilus, conformational changes in the ε-subunit are influenced by intracellular ATP...



Beyond ethanol: A yeast factory for oleochemicals [Applied Biological Sciences]

2016-09-12T12:02:26-07:00

Harnessing lipogenic pathways and rewiring acyl-CoA and acyl-ACP (acyl carrier protein) metabolism in Yarrowia lipolytica hold great potential for cost-efficient production of diesel, gasoline-like fuels, and oleochemicals. Here we assessed various pathway engineering strategies in Y. lipolytica toward developing a yeast biorefinery platform for sustainable production of fuel-like molecules and...



Cross-societal cooperation [Psychological and Cognitive Sciences]

2016-09-12T12:02:27-07:00

In a globalized world, establishing successful cooperation between people from different nations is becoming increasingly important. We present results from a comprehensive investigation of cross-societal cooperation in one-shot prisoner’s dilemmas involving population-representative samples from six countries and identify crucial facilitators of and obstacles to cooperation. In interactions involving mutual knowledge...



CD8 T cell in the pathogenesis of narcolepsy [Medical Sciences]

2016-09-12T12:02:27-07:00

Narcolepsy with cataplexy is a rare and severe sleep disorder caused by the destruction of orexinergic neurons in the lateral hypothalamus. The genetic and environmental factors associated with narcolepsy, together with serologic data, collectively point to an autoimmune origin. The current animal models of narcolepsy, based on either disruption of...



NAF-1 Fe-S clusters promote tumorigenicity [Biophysics and Computational Biology]

2016-09-12T12:02:27-07:00

Iron–sulfur (Fe-S) proteins are thought to play an important role in cancer cells mediating redox reactions, DNA replication, and telomere maintenance. Nutrient-deprivation autophagy factor-1 (NAF-1) is a 2Fe-2S protein associated with the progression of multiple cancer types. It is unique among Fe-S proteins because of its 3Cys-1His cluster coordination structure...



Harnessing adolescent values boosts healthy eating [Psychological and Cognitive Sciences]

2016-09-12T12:02:28-07:00

What can be done to reduce unhealthy eating among adolescents? It was hypothesized that aligning healthy eating with important and widely shared adolescent values would produce the needed motivation. A double-blind, randomized, placebo-controlled experiment with eighth graders (total n = 536) evaluated the impact of a treatment that framed healthy...



Genetic forecasting of bat rabies invasions [Evolution]

2016-09-12T12:02:28-07:00

Anticipating how epidemics will spread across landscapes requires understanding host dispersal events that are notoriously difficult to measure. Here, we contrast host and virus genetic signatures to resolve the spatiotemporal dynamics underlying geographic expansions of vampire bat rabies virus (VBRV) in Peru. Phylogenetic analysis revealed recent viral spread between populations...



Laccase-containing designer cellulosome [Applied Biological Sciences]

2016-09-12T12:02:28-07:00

Efficient breakdown of lignocellulose polymers into simple molecules is a key technological bottleneck limiting the production of plant-derived biofuels and chemicals. In nature, plant biomass degradation is achieved by the action of a wide range of microbial enzymes. In aerobic microorganisms, these enzymes are secreted as discrete elements in contrast...



Pollen dispersal alters response to climate change [Evolution]

2016-09-12T12:02:28-07:00

Species may survive climate change by migrating to track favorable climates and/or adapting to different climates. Several quantitative genetics models predict that species escaping extinction will change their geographical distribution while keeping the same ecological niche. We introduce pollen dispersal in these models, which affects gene flow but not directly...



Real-time 3D MRI of dendrite growth in batteries [Chemistry]

2016-09-12T12:02:29-07:00

Lithium metal is a promising anode material for Li-ion batteries due to its high theoretical specific capacity and low potential. The growth of dendrites is a major barrier to the development of high capacity, rechargeable Li batteries with lithium metal anodes, and hence, significant efforts have been undertaken to develop...



Pip6a-PMO enhances efficacy of SSO therapy for SMA [Medical Sciences]

2016-09-12T12:02:29-07:00

The development of antisense oligonucleotide therapy is an important advance in the identification of corrective therapy for neuromuscular diseases, such as spinal muscular atrophy (SMA). Because of difficulties of delivering single-stranded oligonucleotides to the CNS, current approaches have been restricted to using invasive intrathecal single-stranded oligonucleotide delivery. Here, we report...



E4F1 transcriptional program controlling PDH [Physiology]

2016-09-12T12:02:30-07:00

The mitochondrial pyruvate dehydrogenase (PDH) complex (PDC) acts as a central metabolic node that mediates pyruvate oxidation and fuels the tricarboxylic acid cycle to meet energy demand. Here, we reveal another level of regulation of the pyruvate oxidation pathway in mammals implicating the E4 transcription factor 1 (E4F1). E4F1 controls...



Mammal skin carotenoids [Evolution]

2016-09-12T12:02:30-07:00

Animals cannot synthesize carotenoid pigments de novo, and must consume them in their diet. Most mammals, including humans, are indiscriminate accumulators of carotenoids but inefficiently distribute them to some tissues and organs, such as skin. This limits the potential capacity of these organisms to benefit from the antioxidant and immunostimulatory...



GIV is a GDI for G{alpha}s [Cell Biology]

2016-09-12T12:02:30-07:00

We previously showed that guanine nucleotide-binding (G) protein α subunit (Gα)-interacting vesicle-associated protein (GIV), a guanine-nucleotide exchange factor (GEF), transactivates Gα activity-inhibiting polypeptide 1 (Gαi) proteins in response to growth factors, such as EGF, using a short C-terminal motif. Subsequent work demonstrated that GIV also binds Gαs and that inactive...



Localizing a staggered brown rot mechanism [Microbiology]

2016-09-12T12:02:31-07:00

Wood-degrading brown rot fungi are essential recyclers of plant biomass in forest ecosystems. Their efficient cellulolytic systems, which have potential biotechnological applications, apparently depend on a combination of two mechanisms: lignocellulose oxidation (LOX) by reactive oxygen species (ROS) and polysaccharide hydrolysis by a limited set of glycoside hydrolases (GHs). Given...



Mammalian diversity and primary productivity [Earth, Atmospheric, and Planetary Sciences]

2016-09-12T12:02:31-07:00

At global and regional scales, primary productivity strongly correlates with richness patterns of extant animals across space, suggesting that resource availability and climatic conditions drive patterns of diversity. However, the existence and consistency of such diversity–productivity relationships through geological history is unclear. Here we provide a comprehensive quantitative test of...



Correction for Tien et al., Identification of a dimerization domain in the TMEM16A calcium-activated chloride channel (CaCC) [Corrections]

2016-09-12T12:02:31-07:00

BIOCHEMISTRY Correction for “Identification of a dimerization domain in the TMEM16A calcium-activated chloride channel (CaCC),” by Jason Tien, Hye Young Lee, Daniel L. Minor, Jr., Yuh Nung Jan, and Lily Yeh Jan, which appeared in issue 16, April 16, 2013, of Proc Natl Acad Sci USA (110:6352–6357; first published April...



Implications of 30-y isotopic record of methane [Environmental Sciences]

2016-09-12T12:02:31-07:00

Observations of atmospheric methane (CH4) since the late 1970s and measurements of CH4 trapped in ice and snow reveal a meteoric rise in concentration during much of the twentieth century. Since 1750, levels of atmospheric CH4 have more than doubled to current globally averaged concentration near 1,800 ppb. During the...



Languages share similar sound-meaning associations [Psychological and Cognitive Sciences]

2016-09-12T12:02:32-07:00

It is widely assumed that one of the fundamental properties of spoken language is the arbitrary relation between sound and meaning. Some exceptions in the form of nonarbitrary associations have been documented in linguistics, cognitive science, and anthropology, but these studies only involved small subsets of the 6,000+ languages spoken...



Tuning electronic transport via peptides by Trp [Chemistry]

2016-09-12T12:02:32-07:00

Charge migration for electron transfer via the polypeptide matrix of proteins is a key process in biological energy conversion and signaling systems. It is sensitive to the sequence of amino acids composing the protein and, therefore, offers a tool for chemical control of charge transport across biomaterial-based devices. We designed...



Correction for Ho et al., Itch E3 ubiquitin ligase regulates large tumor suppressor 1 stability [Corrections]

2016-09-12T12:02:32-07:00

CELL BIOLOGY Correction for “Itch E3 ubiquitin ligase regulates large tumor suppressor 1 stability,” by King Ching Ho, Zhonghua Zhou, Yi-Min She, Alex Chun, Terry D. Cyr, and Xiaolong Yang, which appeared in issue 12, March 22, 2011, of Proc Natl Acad Sci USA (108:4870–4875; first published March 7, 2011;...



Transposable element activation in aging flies [Genetics]

2016-09-12T12:02:24-07:00

Transposable elements (TEs) are mobile genetic elements, highly enriched in heterochromatin, that constitute a large percentage of the DNA content of eukaryotic genomes. Aging in Drosophila melanogaster is characterized by loss of repressive heterochromatin structure and loss of silencing of reporter genes in constitutive heterochromatin regions. Using next-generation sequencing, we...



A{beta}42 {beta}-barrel pore-forming oligomers [Biochemistry]

2016-09-12T12:02:24-07:00

The formation of amyloid-β peptide (Aβ) oligomers at the cellular membrane is considered to be a crucial process underlying neurotoxicity in Alzheimer’s disease (AD). Therefore, it is critical to characterize the oligomers that form within a membrane environment. To contribute to this characterization, we have applied strategies widely used to...



Illusory Late Heavy Bombardments [Earth, Atmospheric, and Planetary Sciences]

2016-09-12T12:02:25-07:00

The Late Heavy Bombardment (LHB), a hypothesized impact spike at ∼3.9 Ga, is one of the major scientific concepts to emerge from Apollo-era lunar exploration. A significant portion of the evidence for the existence of the LHB comes from histograms of 40Ar/39Ar “plateau” ages (i.e., regions selected on the basis...



Stromal SPRY1 regulates mammary branching [Developmental Biology]

2016-09-12T12:02:33-07:00

The role of the local microenvironment in influencing cell behavior is central to both normal development and cancer formation. Here, we show that sprouty 1 (SPRY1) modulates the microenvironment to enable proper mammary branching morphogenesis. This process occurs through negative regulation of epidermal growth factor receptor (EGFR) signaling in mammary...



Direct role of Stac3 in skeletal-type EC coupling [Physiology]

2016-09-12T12:02:33-07:00

In skeletal muscle, conformational coupling between CaV1.1 in the plasma membrane and type 1 ryanodine receptor (RyR1) in the sarcoplasmic reticulum (SR) is thought to underlie both excitation–contraction (EC) coupling Ca2+ release from the SR and retrograde coupling by which RyR1 increases the magnitude of the Ca2+ current via CaV1.1....



Tunable failure in marginally rigid matter [Physics]

2016-09-12T12:02:33-07:00

We investigate how material rigidity acts as a key control parameter for the failure of solids under stress. In both experiments and simulations, we demonstrate that material failure can be continuously tuned by varying the underlying rigidity of the material while holding the amount of disorder constant. As the rigidity...



In vivo structured illumination microendoscopy [Medical Sciences]

2016-09-12T12:02:33-07:00

Fiber optic microendoscopy has shown promise for visualization of molecular contrast agents used to study disease in vivo. However, fiber optic microendoscopes have limited optical sectioning capability, and image contrast is limited by out-of-focus light generated in highly scattering tissue. Optical sectioning techniques have been used in microendoscopes to remove...



{beta}-Carotene accumulation and stability in sorghum [Plant Biology]

2016-09-12T12:02:34-07:00

Micronutrient deficiencies are common in locales where people must rely upon sorghum as their staple diet. Sorghum grain is seriously deficient in provitamin A (β-carotene) and in the bioavailability of iron and zinc. Biofortification is a process to improve crops for one or more micronutrient deficiencies. We have developed sorghum...



Fluids by design [Physics]

2016-09-12T12:02:34-07:00

In conventional fluids, viscosity depends on temperature according to a strict relationship. To change this relationship, one must change the molecular nature of the fluid. Here, we create a metafluid whose properties are derived not from the properties of molecules but rather from chaotic waves excited on the surface of...



Divergent H19/Igf2 imprinting across species [Genetics]

2016-09-12T12:02:34-07:00

Genomic imprinting affects a subset of genes in mammals, such that they are expressed in a monoallelic, parent-of-origin–specific manner. These genes are regulated by imprinting control regions (ICRs), cis-regulatory elements that exhibit allele-specific differential DNA methylation. Although genomic imprinting is conserved in mammals, ICRs are genetically divergent across species. This...



PtdIns(4,5)P2 regulation of autophagy [Cell Biology]

2016-09-12T12:02:35-07:00

Autophagy is a regulated self-digestion pathway with fundamental roles in cell homeostasis and diseases. Autophagy is regulated by coordinated actions of a series of autophagy-related (ATG) proteins. The Barkor/ATG14(L)–VPS34 (a class III phosphatidylinositol 3-kinase) complex and its product phosphatidylinositol 3-phosphate [PtdIns(3)P] play key roles in autophagy initiation. ATG14 contains a...



Circadian sex differences in sleep and alertness [Neuroscience]

2016-09-12T12:02:35-07:00

This study quantifies sex differences in the diurnal and circadian variation of sleep and waking while controlling for menstrual cycle phase and hormonal contraceptive use. We compared the diurnal and circadian variation of sleep and alertness of 8 women studied during two phases of the menstrual cycle and 3 women...



Status and reproductive success [Commentaries]

2016-09-12T12:02:35-07:00

Attempts to gain or maintain status are ubiquitous in human social groups, and are particularly evident among men (1). Status rivalries and maneuvers are a common theme in literary works, and of course are amply described and theorized in the social sciences. Sustained analysis of this topic within an evolutionary...



Tunable shear thickening in suspensions [Applied Physical Sciences]

2016-09-12T12:02:35-07:00

Shear thickening, an increase of viscosity with shear rate, is a ubiquitous phenomenon in suspended materials that has implications for broad technological applications. Controlling this thickening behavior remains a major challenge and has led to empirical strategies ranging from altering the particle surfaces and shape to modifying the solvent properties....



Molecular determinants of cadherin ideal bonds [Biophysics and Computational Biology]

2016-09-12T12:02:36-07:00

Classical cadherin cell–cell adhesion proteins are essential for the formation and maintenance of tissue structures; their primary function is to physically couple neighboring cells and withstand mechanical force. Cadherins from opposing cells bind in two distinct trans conformations: strand-swap dimers and X-dimers. As cadherins convert between these conformations, they form...



pH-regulated client specificity of acid chaperones [Biochemistry]

2016-09-12T12:02:36-07:00

HdeA and HdeB constitute the essential chaperone system that functions in the unique periplasmic space of Gram-negative enteric bacteria to confer acid resistance. How this two-chaperone machinery cooperates to protect a broad range of client proteins from acid denaturation while avoiding nonspecific binding during bacterial passage through the highly acidic...



Adaptation and functional diversity of tMDA5 [Immunology and Inflammation]

2016-09-12T12:02:37-07:00

The function of the RIG-I-like receptors (RLRs; including RIG-I, MDA5, and LGP2) as key cytoplasmic sensors of viral pathogen-associated molecular patterns (PAMPs) has been subjected to numerous pathogenic challenges and has undergone a dynamic evolution. We found evolutionary evidence that RIG-I was lost in the Chinese tree shrew lineage. Along...



Ccr2-independent extramedullary monocytopoiesis [Immunology and Inflammation]

2016-09-12T12:02:37-07:00

Monocytes are innate immune cells that interact with their environment through the expression of pattern recognition receptors, including Toll-like receptors (TLRs). Both monocytes and TLRs are implicated in driving persistent inflammation in autoimmune diseases. However, cell-intrinsic mechanisms to control inflammation, including TLR tolerance, are thought to limit inflammatory responses in...



Structural features of a plant reticulon [Cell Biology]

2016-09-12T12:02:37-07:00

Reticulons (RTNs) are a class of endoplasmic reticulum (ER) membrane proteins that are capable of maintaining high membrane curvature, thus helping shape the ER membrane into tubules. The mechanism of action of RTNs is hypothesized to be a combination of wedging, resulting from the transmembrane topology of their conserved reticulon...



Dystroglycan and sarcomeric cytoskeleton [Physiology]

2016-09-13T09:01:51-07:00

Dystroglycan (DG) is a highly expressed extracellular matrix receptor that is linked to the cytoskeleton in skeletal muscle. DG is critical for the function of skeletal muscle, and muscle with primary defects in the expression and/or function of DG throughout development has many pathological features and a severe muscular dystrophy...



Impaired mating behavior in Gnao-knockout mice [Neuroscience]

2016-09-13T09:01:51-07:00

In mammals, initial detection of olfactory stimuli is mediated by sensory neurons in the main olfactory epithelium (MOE) and the vomeronasal organ (VNO). The heterotrimeric GTP-binding protein Go is widely expressed in the MOE and VNO of mice. Early studies indicated that Go expression in VNO sensory neurons is critical...



High-throughput MERFISH [Systems Biology]

2016-09-13T09:01:51-07:00

Image-based approaches to single-cell transcriptomics, in which RNA species are identified and counted in situ via imaging, have emerged as a powerful complement to single-cell methods based on RNA sequencing of dissociated cells. These image-based approaches naturally preserve the native spatial context of RNAs within a cell and the organization...



Box C/D RNAs recognize maximum 10 nt of substrates [Biochemistry]

2016-09-13T09:01:52-07:00

Box C/D RNAs guide site-specific 2′-O-methylation of RNAs in archaea and eukaryotes. The spacer regions between boxes C to D′ and boxes C′ to D contain the guide sequence that can form a stretch of base pairs with substrate RNAs. The lengths of spacer regions and guide-substrate duplexes are variable...



Unreplicated DNA resolved in the next cell cycle [Systems Biology]

2016-08-11T11:43:04-07:00

To prevent rereplication of genomic segments, the eukaryotic cell cycle is divided into two nonoverlapping phases. During late mitosis and G1 replication origins are “licensed” by loading MCM2-7 double hexamers and during S phase licensed replication origins activate to initiate bidirectional replication forks. Replication forks can stall irreversibly, and if...



ECM proteolysis by MMPs dictates cell behavior [Biochemistry]

2016-09-14T11:14:24-07:00

It is well established that the expression profiles of multiple and possibly redundant matrix-remodeling proteases (e.g., collagenases) differ strongly in health, disease, and development. Although enzymatic redundancy might be inferred from their close similarity in structure, their in vivo activity can lead to extremely diverse tissue-remodeling outcomes. We observed that...



Containment of replication errors in eukaryotes [Systems Biology]

2016-09-14T11:14:24-07:00

The replication of DNA is initiated at particular sites on the genome called replication origins (ROs). Understanding the constraints that regulate the distribution of ROs across different organisms is fundamental for quantifying the degree of replication errors and their downstream consequences. Using a simple probabilistic model, we generate a set...



Metabolism studies in Sphingobium sp. SYK-6 [Applied Biological Sciences]

2016-09-15T11:31:38-07:00

Sphingobium sp. SYK-6 is a soil bacterium boasting a well-studied ligninolytic pathway and the potential for development into a microbial chassis for lignin valorization. An improved understanding of its metabolism will help researchers in the engineering of SYK-6 for the production of value-added chemicals through lignin valorization. We used 13C-fingerprinting,...



Nitrate predicts ocean carbon accumulation [Commentaries]

2016-09-16T09:42:04-07:00

Biology and the environment interact, one shaping the other (1). In the oceans, the chemistry of seawater and the chemistry of life are intimately linked (2). In 1958, Alfred Redfield (3) noted that the microscopic plankton of the surface ocean contain carbon, nitrogen, and phosphorous atoms in a stoichiometry of...



Visualizing the emergence of autocatalytic systems [Chemistry]

2016-09-16T09:42:04-07:00

Autocatalytic chemical reactions are widely studied as models of biological processes and to better understand the origins of life on Earth. Minimal self-reproducing amphiphiles have been developed in this context and as an approach to de novo “bottom–up” synthetic protocells. How chemicals come together to produce living systems, however, remains...



Anticipating collapse; Hints from the Stone Age [Commentaries]

2016-09-16T09:42:05-07:00

Few aspects of human history are as mindboggling as the sudden disintegration of advanced societies. It is tempting to seek common patterns or even draw some lessons for modern times from the many ancient cases of societal disintegration. In PNAS, Downey et al. (1) report that universal warning signals of...



Leveraging premalignant biology: Immune prevention [Perspectives]

2016-09-16T08:40:54-07:00

Prevention is an essential component of cancer eradication. Next-generation sequencing of cancer genomes and epigenomes has defined large numbers of driver mutations and molecular subgroups, leading to therapeutic advances. By comparison, there is a relative paucity of such knowledge in premalignant neoplasia, which inherently limits the potential to develop precision...



When fairness matters less than we expect [Psychological and Cognitive Sciences]

2016-09-16T08:40:55-07:00

Do those who allocate resources know how much fairness will matter to those who receive them? Across seven studies, allocators used either a fair or unfair procedure to determine which of two receivers would receive the most money. Allocators consistently overestimated the impact that the fairness of the allocation procedure...



Invasive predators and global biodiversity loss [Ecology]

2016-09-16T08:40:55-07:00

Invasive species threaten biodiversity globally, and invasive mammalian predators are particularly damaging, having contributed to considerable species decline and extinction. We provide a global metaanalysis of these impacts and reveal their full extent. Invasive predators are implicated in 87 bird, 45 mammal, and 10 reptile species extinctions—58% of these groups’...



Autophagy induction promotes axon regeneration [Neuroscience]

2016-09-16T08:40:55-07:00

Remodeling of cytoskeleton structures, such as microtubule assembly, is believed to be crucial for growth cone initiation and regrowth of injured axons. Autophagy plays important roles in maintaining cellular homoeostasis, and its dysfunction causes neuronal degeneration. The role of autophagy in axon regeneration after injury remains speculative. Here we demonstrate...



High fat alters the small intestinal ecosystem [Microbiology]

2016-09-16T08:40:55-07:00

Diet is among the most important factors contributing to intestinal homeostasis, and basic functions performed by the small intestine need to be tightly preserved to maintain health. Little is known about the direct impact of high-fat (HF) diet on small-intestinal mucosal defenses and spatial distribution of the microbiota during the...



Maritime adaptation in the western Pacific by 35 ka [Anthropology]

2016-09-16T08:40:56-07:00

Maritime adaptation was one of the essential factors that enabled modern humans to disperse all over the world. However, geographic distribution of early maritime technology during the Late Pleistocene remains unclear. At this time, the Indonesian Archipelago and eastern New Guinea stand as the sole, well-recognized area for secure Pleistocene...



Neurobiology of number in congenital blindness [Psychological and Cognitive Sciences]

2016-09-16T08:40:56-07:00

In humans, the ability to reason about mathematical quantities depends on a frontoparietal network that includes the intraparietal sulcus (IPS). How do nature and nurture give rise to the neurobiology of numerical cognition? We asked how visual experience shapes the neural basis of numerical thinking by studying numerical cognition in...



LCPUFA support aerial insectivore performance [Ecology]

2016-09-16T08:40:56-07:00

Once-abundant aerial insectivores, such as the Tree Swallow (Tachycineta bicolor), have declined steadily in the past several decades, making it imperative to understand all aspects of their ecology. Aerial insectivores forage on a mixture of aquatic and terrestrial insects that differ in fatty acid composition, specifically long-chain omega-3 polyunsaturated fatty...



Orthographic processing in pigeons [Psychological and Cognitive Sciences]

2016-09-16T08:40:56-07:00

Learning to read involves the acquisition of letter–sound relationships (i.e., decoding skills) and the ability to visually recognize words (i.e., orthographic knowledge). Although decoding skills are clearly human-unique, given they are seated in language, recent research and theory suggest that orthographic processing may derive from the exaptation or recycling of...



Proteomic evidence for Chatelperronian hominins [Anthropology]

2016-09-16T08:40:54-07:00

In Western Europe, the Middle to Upper Paleolithic transition is associated with the disappearance of Neandertals and the spread of anatomically modern humans (AMHs). Current chronological, behavioral, and biological models of this transitional period hinge on the Châtelperronian technocomplex. At the site of the Grotte du Renne, Arcy-sur-Cure, morphological Neandertal...



TRPV1 supports heat tolerance in squirrels, camels [Physiology]

2016-09-16T08:40:54-07:00

The ability to sense heat is crucial for survival. Increased heat tolerance may prove beneficial by conferring the ability to inhabit otherwise prohibitive ecological niches. This phenomenon is widespread and is found in both large and small animals. For example, ground squirrels and camels can tolerate temperatures more than 40...



Fate of the Amazon forests and the Third Way [Sustainability Science]

2016-09-16T08:40:54-07:00

For half a century, the process of economic integration of the Amazon has been based on intensive use of renewable and nonrenewable natural resources, which has brought significant basin-wide environmental alterations. The rural development in the Amazonia pushed the agricultural frontier swiftly, resulting in widespread land-cover change, but agriculture in...



Hippocampus and language processing [Psychological and Cognitive Sciences]

2016-09-19T12:06:46-07:00

Language is classically thought to be supported by perisylvian cortical regions. Here we provide intracranial evidence linking the hippocampal complex to linguistic processing. We used direct recordings from the hippocampal structures to investigate whether theta oscillations, pivotal in memory function, track the amount of contextual linguistic information provided in sentences....



Macropinosome recycling via WASH [Cell Biology]

2016-09-19T12:06:46-07:00

Macropinocytosis is an ancient mechanism that allows cells to harvest nutrients from extracellular media, which also allows immune cells to sample antigens from their surroundings. During macropinosome formation, bulk plasma membrane is internalized with all its integral proteins. It is vital for cells to salvage these proteins before degradation, but...



Cerebral nuclei connectome [Neuroscience]

2016-09-19T12:06:46-07:00

The cerebral nuclei form the ventral division of the cerebral hemisphere and are thought to play an important role in neural systems controlling somatic movement and motivation. Network analysis was used to define global architectural features of intrinsic cerebral nuclei circuitry in one hemisphere (association connections) and between hemispheres (commissural...



SVM predicts zoonotic potential of E. coli O157 [Microbiology]

2016-09-19T12:06:47-07:00

Sequence analyses of pathogen genomes facilitate the tracking of disease outbreaks and allow relationships between strains to be reconstructed and virulence factors to be identified. However, these methods are generally used after an outbreak has happened. Here, we show that support vector machine analysis of bovine E. coli O157 isolate...



TCO induced by liquid electrolyte gating [Physics]

2016-09-19T12:06:47-07:00

Optically transparent conducting materials are essential in modern technology. These materials are used as electrodes in displays, photovoltaic cells, and touchscreens; they are also used in energy-conserving windows to reflect the infrared spectrum. The most ubiquitous transparent conducting material is tin-doped indium oxide (ITO), a wide-gap oxide whose conductivity is...



Structure of norovirus HBGA blocking mAb complex [Biochemistry]

2016-09-19T12:06:47-07:00

Human noroviruses (HuNoVs) cause sporadic and epidemic gastroenteritis worldwide. They are classified into two major genogroups (GI and GII), with each genogroup further divided into multiple genotypes. Susceptibility to these viruses is influenced by genetically determined histo-blood group antigen (HBGA) expression. HBGAs function as cell attachment factors by binding to...



Vitamin B6 biosynthesis in Arabidopsis [Biochemistry]

2016-09-19T12:06:48-07:00

Vitamin B6 is indispensible for all organisms, notably as the coenzyme form pyridoxal 5′-phosphate. Plants make the compound de novo using a relatively simple pathway comprising pyridoxine synthase (PDX1) and pyridoxine glutaminase (PDX2). PDX1 is remarkable given its multifaceted synthetic ability to carry out isomerization, imine formation, ammonia addition, aldol-type...



Crystal structures and dynamical properties of CO2 [Chemistry]

2016-09-19T12:06:48-07:00

Structural polymorphism in dense carbon dioxide (CO2) has attracted significant attention in high-pressure physics and chemistry for the past two decades. Here, we have performed high-pressure experiments and first-principles theoretical calculations to investigate the stability, structure, and dynamical properties of dense CO2. We found evidence that CO2-V with the 4-coordinated...



Passive dynamics of E. coli's downshock response [Biophysics and Computational Biology]

2016-09-19T12:06:48-07:00

For most cells, a sudden decrease in external osmolarity results in fast water influx that can burst the cell. To survive, cells rely on the passive response of mechanosensitive channels, which open under increased membrane tension and allow the release of cytoplasmic solutes and water. Although the gating and the...



Myosin-5a in complex with Ca2+-calmodulin [Biochemistry]

2016-09-19T12:06:48-07:00

The motor function of vertebrate myosin-5a is inhibited by its tail in a Ca2+-dependent manner. We previously demonstrated that the calmodulin (CaM) bound to the first isoleucine-glutamine (IQ) motif (IQ1) of myosin-5a is responsible for the Ca2+-dependent regulation of myosin-5a. We have solved the crystal structure of a truncated myosin-5a...



Superflexibility of graphene oxide [Applied Physical Sciences]

2016-09-19T12:06:48-07:00

Graphene oxide (GO), the main precursor of graphene-based materials made by solution processing, is known to be very stiff. Indeed, it has a Young’s modulus comparable to steel, on the order of 300 GPa. Despite its very high stiffness, we show here that GO is superflexible. We quantitatively measure the...



Rotation of artificial rotor axles [Biophysics and Computational Biology]

2016-09-19T12:06:49-07:00

F1- and V1-ATPase are rotary molecular motors that convert chemical energy released upon ATP hydrolysis into torque to rotate a central rotor axle against the surrounding catalytic stator cylinder with high efficiency. How conformational change occurring in the stator is coupled to the rotary motion of the axle is the...



Nanoparticles size-dependently induce NETosis [Cell Biology]

2016-09-19T12:06:49-07:00

The critical size for strong interaction of hydrophobic particles with phospholipid bilayers has been predicted to be 10 nm. Because of the wide spreading of nonpolar nanoparticles (NPs) in the environment, we aimed to reveal the ability of living organisms to entrap NPs via formation of neutrophil extracellular traps (NETs)....



Mitofusin 2 tethers mitochondria to ER [Cell Biology]

2016-09-19T12:06:49-07:00

The discovery of the multiple roles of mitochondria–endoplasmic reticulum (ER) juxtaposition in cell biology often relied upon the exploitation of Mitofusin (Mfn) 2 as an ER–mitochondria tether. However, this established Mfn2 function was recently questioned, calling for a critical re-evaluation of Mfn2’s role in ER–mitochondria cross-talk. Electron microscopy and fluorescence-based...



Striosome-dendron bouquets [Neuroscience]

2016-09-19T12:06:49-07:00

The dopamine systems of the brain powerfully influence movement and motivation. We demonstrate that striatonigral fibers originating in striosomes form highly unusual bouquet-like arborizations that target bundles of ventrally extending dopamine-containing dendrites and clusters of their parent nigral cell bodies. Retrograde tracing showed that these clustered cell bodies in turn...



Evolution of adaptation to varying environments [Physics]

2016-09-19T12:06:49-07:00

Organisms can adapt to a randomly varying environment by creating phenotypic diversity in their population, a phenomenon often referred to as “bet hedging.” The favorable level of phenotypic diversity depends on the statistics of environmental variations over timescales of many generations. Could organisms gather such long-term environmental information to adjust...



Modeling universals and variation in focal colors [Psychological and Cognitive Sciences]

2016-09-19T12:06:50-07:00

Focal colors, or best examples of color terms, have traditionally been viewed as either the underlying source of cross-language color-naming universals or derived from category boundaries that vary widely across languages. Existing data partially support and partially challenge each of these views. Here, we advance a position that synthesizes aspects...



BMI1 and UBR5 induce gene silencing at UV lesions [Cell Biology]

2016-09-19T12:06:50-07:00

BMI1 is a component of the Polycomb Repressive Complex 1 (PRC1), which plays a key role in maintaining epigenetic silencing during development. BMI1 also participates in gene silencing during DNA damage response, but the precise downstream function of BMI1 in gene silencing is unclear. Here we identified the UBR5 E3...



Cellulose biosynthesis by a single CesA isoform [Plant Biology]

2016-09-19T12:06:50-07:00

Plant cell walls are a composite material of polysaccharides, proteins, and other noncarbohydrate polymers. In the majority of plant tissues, the most abundant polysaccharide is cellulose, a linear polymer of glucose molecules. As the load-bearing component of the cell wall, individual cellulose chains are frequently bundled into micro and macrofibrils...



Mechanical approach to chemical transport [Chemistry]

2016-09-19T12:06:50-07:00

Nonequilibrium thermodynamics describes the rates of transport phenomena with the aid of various thermodynamic forces, but often the phenomenological transport coefficients are not known, and the description is not easily connected with equilibrium relations. We present a simple and intuitive model to address these issues. Our model is based on...



Fluorescent metallacycle-cored polymers [Chemistry]

2016-09-19T12:06:50-07:00

The covalent linkage of supramolecular monomers provides a powerful strategy for constructing dynamic polymeric materials whose properties can be readily tuned either by the selection of monomers or the choice of functional linkers. In this strategy, the stabilities of the supramolecular monomers and the reactions used to link the monomers...



Fast revascularization supports heart regeneration [Cell Biology]

2016-09-19T12:06:51-07:00

Zebrafish have a remarkable capacity to regenerate their heart. Efficient replenishment of lost tissues requires the activation of different cell types including the epicardium and endocardium. A complex set of processes is subsequently needed to support cardiomyocyte repopulation. Previous studies have identified important determinants of heart regeneration; however, to date,...



Molecular interactions in auxin response circuits [Plant Biology]

2016-09-19T12:06:51-07:00

Auxin-regulated transcription pivots on the interaction between the AUXIN/INDOLE-3-ACETIC ACID (Aux/IAA) repressor proteins and the AUXIN RESPONSE FACTOR (ARF) transcription factors. Recent structural analyses of ARFs and Aux/IAAs have raised questions about the functional complexes driving auxin transcriptional responses. To parse the nature and significance of ARF–DNA and ARF–Aux/IAA interactions,...



Ab initio structure determination by MicroED [Biophysics and Computational Biology]

2016-09-19T12:06:51-07:00

Electrons, because of their strong interaction with matter, produce high-resolution diffraction patterns from tiny 3D crystals only a few hundred nanometers thick in a frozen-hydrated state. This discovery offers the prospect of facile structure determination of complex biological macromolecules, which cannot be coaxed to form crystals large enough for conventional...



Theory of {delta}-plutonium's temperature response [Physics]

2016-09-19T12:06:51-07:00

The electronic and thermodynamic complexity of plutonium has resisted a fundamental understanding for this important elemental metal. A critical test of any theory is the unusual softening of the bulk modulus with increasing temperature, a result that is counterintuitive because no or very little change in the atomic volume is...



NsD7 binds PA to form oligomeric complexes [Biochemistry]

2016-09-19T12:06:51-07:00

Defensins are cationic antimicrobial peptides that serve as important components of host innate immune defenses, often by targeting cell membranes of pathogens. Oligomerization of defensins has been linked to their antimicrobial activity; however, the molecular basis underpinning this process remains largely unclear. Here we show that the plant defensin NsD7...



Zn2+ inhibition of a voltage-gated proton channel [Neuroscience]

2016-09-19T12:06:52-07:00

Voltage-gated proton (Hv1) channels are involved in many physiological processes, such as pH homeostasis and the innate immune response. Zn2+ is an important physiological inhibitor of Hv1. Sperm cells are quiescent in the male reproductive system due to Zn2+ inhibition of Hv1 channels, but become active once introduced into the...