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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...



Heterogeneity and scale of sustainable development in cities [Sustainability Science]

2017-05-01T12:09:28-07:00

Rapid worldwide urbanization is at once the main cause and, potentially, the main solution to global sustainable development challenges. The growth of cities is typically associated with increases in socioeconomic productivity, but it also creates strong inequalities. Despite a growing body of evidence characterizing these heterogeneities in developed urban areas,...



Solar thermochemical splitting of water to generate hydrogen [Perspectives]

2017-05-18T11:58:25-07:00

Solar photochemical means of splitting water (artificial photosynthesis) to generate hydrogen is emerging as a viable process. The solar thermochemical route also promises to be an attractive means of achieving this objective. In this paper we present different types of thermochemical cycles that one can use for the purpose. These...



Water is an active matrix of life for cell and molecular biology [Perspectives]

2017-06-07T12:43:37-07:00

Szent-Győrgi called water the “matrix of life” and claimed that there was no life without it. This statement is true, as far as we know, on our planet, but it is not clear whether it must hold throughout the cosmos. To evaluate that question requires a close consideration of the...



Microscopic dynamics of charge separation at the aqueous electrochemical interface [Chemistry]

2017-07-11T09:36:45-07:00

We have used molecular simulation and methods of importance sampling to study the thermodynamics and kinetics of ionic charge separation at a liquid water–metal interface. We have considered this process using canonical examples of two different classes of ions: a simple alkali–halide pair, Na+I−, or classical ions, and the products...



Bidirectional manipulation of mTOR signaling disrupts socially mediated vocal learning in juvenile songbirds [Neuroscience]

2017-07-24T11:55:09-07:00

Early life experiences can have long-lasting behavioral consequences because they are encoded when the brain is most malleable. The mechanistic target of rapamycin (mTOR) signaling cascade modulates experience-dependent synaptic plasticity, among other processes. mTOR has been almost exclusively examined in adult rodent learning models, but may be especially important in...



Assessing benefits, costs, and disparate racial impacts of confrontational proactive policing [Economic Sciences]

2017-07-24T11:55:04-07:00

Effective policing in a democratic society must balance the sometime conflicting objectives of public safety and community trust. This paper uses a formal model of optimal policing to explore how society might reasonably resolve the tension between these two objectives as well as evaluate disparate racial impacts. We do so...



Social network fragmentation and community health [Social Sciences]

2017-07-24T11:54:59-07:00

Community health interventions often seek to intentionally destroy paths between individuals to prevent the spread of infectious diseases. Immunizing individuals through direct vaccination or the provision of health education prevents pathogen transmission and the propagation of misinformation concerning medical treatments. However, it remains an open question whether network-based strategies should...



Structural basis of kindlin-mediated integrin recognition and activation [Biochemistry]

2017-07-24T11:55:09-07:00

Kindlins and talins are integrin-binding proteins that are critically involved in integrin activation, an essential process for many fundamental cellular activities including cell-matrix adhesion, migration, and proliferation. As FERM-domain–containing proteins, talins and kindlins, respectively, bind different regions of β-integrin cytoplasmic tails. However, compared with the extensively studied talin, little is...



Metal-mediated diradical tuning for DNA replication arrest via template strand scission [Chemistry]

2017-07-31T11:50:59-07:00

A series of M(PyED)·X (X = 2Cl−, SO42−) pyridine–metalloenediyne complexes [M = Cu(II), Fe(II), or Zn(II)] and their independently synthesized, cyclized analogs have been prepared to investigate their potential as radical-generating DNA-damaging agents. All complexes possess a 1:1 metal-to-ligand stoichiometry as determined by electronic absorption spectroscopy and X-ray diffraction. Solution...



Molecular characterization of water and surfactant AOT at nanoemulsion surfaces [Chemistry]

2017-07-31T11:51:02-07:00

Nanoemulsions and microemulsions are environments where oil and water can be solubilized in one another to provide a unique platform for many different biological and industrial applications. Nanoemulsions, unlike microemulsions, have seen little work done to characterize molecular interactions at their surfaces. This study provides a detailed investigation of the...



Deep evolutionary conservation of autism-related genes [Evolution]

2017-07-31T11:51:00-07:00

E. O. Wilson proposed in Sociobiology that similarities between human and animal societies reflect common mechanistic and evolutionary roots. When introduced in 1975, this controversial hypothesis was beyond science’s ability to test. We used genomic analyses to determine whether superficial behavioral similarities in humans and the highly social honey bee...



Nasopharyngeal infection by Streptococcus pyogenes requires superantigen-responsive V{beta}-specific T cells [Microbiology]

2017-08-09T11:34:49-07:00

The globally prominent pathogen Streptococcus pyogenes secretes potent immunomodulatory proteins known as superantigens (SAgs), which engage lateral surfaces of major histocompatibility class II molecules and T-cell receptor (TCR) β-chain variable domains (Vβs). These interactions result in the activation of numerous Vβ-specific T cells, which is the defining activity of a...



Lethality of MalE-LacZ hybrid protein shares mechanistic attributes with oxidative component of antibiotic lethality [Microbiology]

2017-08-09T11:34:49-07:00

Downstream metabolic events can contribute to the lethality of drugs or agents that interact with a primary cellular target. In bacteria, the production of reactive oxygen species (ROS) has been associated with the lethal effects of a variety of stresses including bactericidal antibiotics, but the relative contribution of this oxidative...



Phosphoantigen-induced conformational change of butyrophilin 3A1 (BTN3A1) and its implication on V{gamma}9V{delta}2 T cell activation [Immunology and Inflammation]

2017-08-14T11:44:59-07:00

Human Vγ9Vδ2 T cells respond to microbial infections as well as certain types of tumors. The key initiators of Vγ9Vδ2 activation are small, pyrophosphate-containing molecules called phosphoantigens (pAgs) that are present in infected cells or accumulate intracellularly in certain tumor cells. Recent studies demonstrate that initiation of the Vγ9Vδ2 T...



Immunogenicity and structures of a rationally designed prefusion MERS-CoV spike antigen [Microbiology]

2017-08-14T11:44:59-07:00

Middle East respiratory syndrome coronavirus (MERS-CoV) is a lineage C betacoronavirus that since its emergence in 2012 has caused outbreaks in human populations with case-fatality rates of ∼36%. As in other coronaviruses, the spike (S) glycoprotein of MERS-CoV mediates receptor recognition and membrane fusion and is the primary target of...



Role of co-occurring competition and facilitation in plant spacing hydrodynamics in water-limited environments [Environmental Sciences]

2017-08-14T11:45:00-07:00

Plant performance (i.e., fecundity, growth, survival) depends on an individual’s access to space and resources. At the community level, plant performance is reflected in observable vegetation patterning (i.e., spacing distance, density) often controlled by limiting resources. Resource availability is, in turn, strongly dependent on plant patterning mediated by competitive and...



Vibrio cholerae type 6 secretion system effector trafficking in target bacterial cells [Microbiology]

2017-08-14T11:45:00-07:00

The type 6 secretion system (T6SS) is used by many Gram-negative bacterial species to deliver toxic effector proteins into nearby bacteria prey cells to kill or inhibit their growth. VgrG proteins are core conserved secretion substrates of the T6SS and one subset of T6SS effectors consists of VgrG proteins with...



Two transmembrane dimers of the bovine papillomavirus E5 oncoprotein clamp the PDGF {beta} receptor in an active dimeric conformation [Biochemistry]

2017-08-14T11:45:00-07:00

The dimeric 44-residue E5 protein of bovine papillomavirus is the smallest known naturally occurring oncoprotein. This transmembrane protein binds to the transmembrane domain (TMD) of the platelet-derived growth factor β receptor (PDGFβR), causing dimerization and activation of the receptor. Here, we use Rosetta membrane modeling and all-atom molecular dynamics simulations...



Optimized strategy for in vivo Cas9-activation in Drosophila [Genetics]

2017-08-14T11:45:00-07:00

While several large-scale resources are available for in vivo loss-of-function studies in Drosophila, an analogous resource for overexpressing genes from their endogenous loci does not exist. We describe a strategy for generating such a resource using Cas9 transcriptional activators (CRISPRa). First, we compare a panel of CRISPRa approaches and demonstrate...



Signaling from the plasma-membrane localized plant immune receptor RPM1 requires self-association of the full-length protein [Plant Biology]

2017-08-14T11:45:01-07:00

Plants evolved intracellular immune receptors that belong to the NOD-like receptor (NLR) family to recognize the presence of pathogen-derived effector proteins. NLRs possess an N-terminal Toll-like/IL-1 receptor (TIR) or a non-TIR domain [some of which contain coiled coils (CCs)], a central nucleotide-binding (NB-ARC) domain, and a C-terminal leucine-rich repeat (LRR)....



Critical structural fluctuations of proteins upon thermal unfolding challenge the Lindemann criterion [Biophysics and Computational Biology]

2017-08-14T11:45:01-07:00

Internal subnanosecond timescale motions are key for the function of proteins, and are coupled to the surrounding solvent environment. These fast fluctuations guide protein conformational changes, yet their role for protein stability, and for unfolding, remains elusive. Here, in analogy with the Lindemann criterion for the melting of solids, we...



Conformational dynamics of 1-deoxy-d-xylulose 5-phosphate synthase on ligand binding revealed by H/D exchange MS [Biochemistry]

2017-08-14T11:45:01-07:00

The enzyme 1-deoxy-d-xylulose 5-phosphate synthase (DXPS) is a key enzyme in the methylerythritol 4-phosphate pathway and is a target for the development of antibiotics, herbicides, and antimalarial drugs. DXPS catalyzes the formation of 1-deoxy-d-xylulose 5-phosphate (DXP), a branch point metabolite in isoprenoid biosynthesis, and is also used in the biosynthesis...



Impact of catch shares on diversification of fishers’ income and risk [Sustainability Science]

2017-08-14T11:45:01-07:00

Many fishers diversify their income by participating in multiple fisheries, which has been shown to significantly reduce year-to-year variation in income. The ability of fishers to diversify has become increasingly constrained in the last few decades, and catch share programs could further reduce diversification as a result of consolidation. This...



Early photosynthetic eukaryotes inhabited low-salinity habitats [Evolution]

2017-08-14T11:45:01-07:00

The early evolutionary history of the chloroplast lineage remains an open question. It is widely accepted that the endosymbiosis that established the chloroplast lineage in eukaryotes can be traced back to a single event, in which a cyanobacterium was incorporated into a protistan host. It is still unclear, however, which...



Mathematical model reveals role of nucleotide signaling in airway surface liquid homeostasis and its dysregulation in cystic fibrosis [Biophysics and Computational Biology]

2017-08-14T11:45:02-07:00

Mucociliary clearance is composed of three components (i.e., mucin secretion, airway surface hydration, and ciliary-activity) which function coordinately to clear inhaled microbes and other foreign particles from airway surfaces. Airway surface hydration is maintained by water fluxes driven predominantly by active chloride and sodium ion transport. The ion channels that...



A protein complex regulates RNA processing of intronic heterochromatin-containing genes in Arabidopsis [Plant Biology]

2017-08-14T11:45:02-07:00

In several eukaryotic organisms, heterochromatin (HC) in the introns of genes can regulate RNA processing, including polyadenylation, but the mechanism underlying this regulation is poorly understood. By promoting distal polyadenylation, the bromo-adjacent homology (BAH) domain-containing and RNA recognition motif-containing protein ASI1 and the H3K9me2-binding protein EDM2 are required for the...



Voltage-gated calcium flux mediates Escherichia coli mechanosensation [Microbiology]

2017-08-14T11:45:02-07:00

Electrically excitable cells harness voltage-coupled calcium influx to transmit intracellular signals, typically studied in neurons and cardiomyocytes. Despite intense study in higher organisms, investigations of voltage and calcium signaling in bacteria have lagged due to their small size and a lack of sensitive tools. Only recently were bacteria shown to...



Behavioral responses to annual temperature variation alter the dominant energy pathway, growth, and condition of a cold-water predator [Environmental Sciences]

2017-08-14T11:45:02-07:00

There is a pressing need to understand how ecosystems will respond to climate change. To date, no long-term empirical studies have confirmed that fish populations exhibit adaptive foraging behavior in response to temperature variation and the potential implications this has on fitness. Here, we use an unparalleled 11-y acoustic telemetry,...



BDNF-TrkB controls cocaine-induced dendritic spines in rodent nucleus accumbens dissociated from increases in addictive behaviors [Neuroscience]

2017-08-14T11:45:03-07:00

Chronic cocaine use is associated with prominent morphological changes in nucleus accumbens shell (NACsh) neurons, including increases in dendritic spine density along with enhanced motivation for cocaine, but a functional relationship between these morphological and behavioral phenomena has not been shown. Here we show that brain-derived neurotrophic factor (BDNF) signaling...



Disaggregating sorghum yield reductions under warming scenarios exposes narrow genetic diversity in US breeding programs [Sustainability Science]

2017-08-14T11:45:03-07:00

Historical adaptation of sorghum production to arid and semiarid conditions has provided promise regarding its sustained productivity under future warming scenarios. Using Kansas field-trial sorghum data collected from 1985 to 2014 and spanning 408 hybrid cultivars, we show that sorghum productivity under increasing warming scenarios breaks down. Through extensive regression...



Adaptive benefit of cross-modal plasticity following cochlear implantation in deaf adults [Neuroscience]

2017-08-14T11:45:03-07:00

It has been suggested that visual language is maladaptive for hearing restoration with a cochlear implant (CI) due to cross-modal recruitment of auditory brain regions. Rehabilitative guidelines therefore discourage the use of visual language. However, neuroscientific understanding of cross-modal plasticity following cochlear implantation has been restricted due to incompatibility between...



A p53-dependent response limits the viability of mammalian haploid cells [Cell Biology]

2017-08-14T11:45:03-07:00

The recent development of haploid cell lines has facilitated forward genetic screenings in mammalian cells. These lines include near-haploid human cell lines isolated from a patient with chronic myelogenous leukemia (KBM7 and HAP1), as well as haploid embryonic stem cells derived from several organisms. In all cases, haploidy was shown...



Hydrodynamics of microbial filter feeding [Applied Physical Sciences]

2017-08-14T11:45:03-07:00

Microbial filter feeders are an important group of grazers, significant to the microbial loop, aquatic food webs, and biogeochemical cycling. Our understanding of microbial filter feeding is poor, and, importantly, it is unknown what force microbial filter feeders must generate to process adequate amounts of water. Also, the trade-off in...



Antitumor effect of Batf2 through IL-12 p40 up-regulation in tumor-associated macrophages [Immunology and Inflammation]

2017-08-14T11:45:04-07:00

The development of effective treatments against cancers is urgently needed, and the accumulation of CD8+ T cells within tumors is especially important for cancer prognosis. Although their mechanisms are still largely unknown, growing evidence has indicated that innate immune cells have important effects on cancer progression through the production of...



A genome Tree of Life for the Fungi kingdom [Evolution]

2017-08-14T11:45:04-07:00

Fungi belong to one of the largest and most diverse kingdoms of living organisms. The evolutionary kinship within a fungal population has so far been inferred mostly from the gene-information–based trees (“gene trees”), constructed commonly based on the degree of differences of proteins or DNA sequences of a small number...



Next step in the ongoing arms race between myxoma virus and wild rabbits in Australia is a novel disease phenotype [Evolution]

2017-08-14T11:45:04-07:00

In host–pathogen arms races, increases in host resistance prompt counteradaptation by pathogens, but the nature of that counteradaptation is seldom directly observed outside of laboratory models. The best-documented field example is the coevolution of myxoma virus (MYXV) in European rabbits. To understand how MYXV in Australia has continued to evolve...



KCNE1 and KCNE3 modulate KCNQ1 channels by affecting different gating transitions [Physiology]

2017-08-14T11:45:04-07:00

KCNE β-subunits assemble with and modulate the properties of voltage-gated K+ channels. In the heart, KCNE1 associates with the α-subunit KCNQ1 to generate the slowly activating, voltage-dependent potassium current (IKs) in the heart that controls the repolarization phase of cardiac action potentials. By contrast, in epithelial cells from the colon,...



Kinetic and high-throughput profiling of epigenetic interactions by 3D-carbene chip-based surface plasmon resonance imaging technology [Biochemistry]

2017-08-14T11:45:04-07:00

Chemical modifications on histones and DNA/RNA constitute a fundamental mechanism for epigenetic regulation. These modifications often function as docking marks to recruit or stabilize cognate “reader” proteins. So far, a platform for quantitative and high-throughput profiling of the epigenetic interactome is urgently needed but still lacking. Here, we report a...



Genomic evidence reveals a radiation of placental mammals uninterrupted by the KPg boundary [Evolution]

2017-08-14T11:45:05-07:00

The timing of the diversification of placental mammals relative to the Cretaceous–Paleogene (KPg) boundary mass extinction remains highly controversial. In particular, there have been seemingly irreconcilable differences in the dating of the early placental radiation not only between fossil-based and molecular datasets but also among molecular datasets. To help resolve...



Prefrontal cortex modulates posterior alpha oscillations during top-down guided visual perception [Psychological and Cognitive Sciences]

2017-08-14T11:45:05-07:00

Conscious visual perception is proposed to arise from the selective synchronization of functionally specialized but widely distributed cortical areas. It has been suggested that different frequency bands index distinct canonical computations. Here, we probed visual perception on a fine-grained temporal scale to study the oscillatory dynamics supporting prefrontal-dependent sensory processing....



Structural and functional studies of pyruvate carboxylase regulation by cyclic di-AMP in lactic acid bacteria [Biochemistry]

2017-08-14T11:45:05-07:00

Cyclic di-3′,5′-adenosine monophosphate (c-di-AMP) is a broadly conserved bacterial second messenger that has been implicated in a wide range of cellular processes. Our earlier studies showed that c-di-AMP regulates central metabolism in Listeria monocytogenes by inhibiting its pyruvate carboxylase (LmPC), a biotin-dependent enzyme with biotin carboxylase (BC) and carboxyltransferase (CT)...



Knee osteoarthritis has doubled in prevalence since the mid-20th century [Anthropology]

2017-08-14T11:45:05-07:00

Knee osteoarthritis (OA) is believed to be highly prevalent today because of recent increases in life expectancy and body mass index (BMI), but this assumption has not been tested using long-term historical or evolutionary data. We analyzed long-term trends in knee OA prevalence in the United States using cadaver-derived skeletons...



Superior colliculus encodes visual saliency before the primary visual cortex [Psychological and Cognitive Sciences]

2017-08-14T11:45:06-07:00

Models of visual attention postulate the existence of a bottom-up saliency map that is formed early in the visual processing stream. Although studies have reported evidence of a saliency map in various cortical brain areas, determining the contribution of phylogenetically older pathways is crucial to understanding its origin. Here, we...



De novo mutations in inhibitors of Wnt, BMP, and Ras/ERK signaling pathways in non-syndromic midline craniosynostosis [Medical Sciences]

2017-08-14T11:45:06-07:00

Non-syndromic craniosynostosis (NSC) is a frequent congenital malformation in which one or more cranial sutures fuse prematurely. Mutations causing rare syndromic craniosynostoses in humans and engineered mouse models commonly increase signaling of the Wnt, bone morphogenetic protein (BMP), or Ras/ERK pathways, converging on shared nuclear targets that promote bone formation....



Immune evasion by a staphylococcal inhibitor of myeloperoxidase [Microbiology]

2017-08-14T11:45:06-07:00

Staphylococcus aureus is highly adapted to its host and has evolved many strategies to resist opsonization and phagocytosis. Even after uptake by neutrophils, S. aureus shows resistance to killing, which suggests the presence of phagosomal immune evasion molecules. With the aid of secretome phage display, we identified a highly conserved...



Elucidating crosstalk mechanisms between phosphorylation and O-GlcNAcylation [Biochemistry]

2017-08-14T11:45:06-07:00

Proteins can be modified by multiple posttranslational modifications (PTMs), creating a PTM code that controls the function of proteins in space and time. Unraveling this complex PTM code is one of the great challenges in molecular biology. Here, using mass spectrometry-based assays, we focus on the most common PTMs—phosphorylation and...



Oxytocin-enforced norm compliance reduces xenophobic outgroup rejection [Psychological and Cognitive Sciences]

2017-08-14T11:45:07-07:00

Never before have individuals had to adapt to social environments defined by such magnitudes of ethnic diversity and cultural differentiation. However, neurobiological evidence informing about strategies to reduce xenophobic sentiment and foster altruistic cooperation with outsiders is scarce. In a series of experiments settled in the context of the current...



Changes in aggregation states of light-harvesting complexes as a mechanism for modulating energy transfer in desert crust cyanobacteria [Plant Biology]

2017-08-14T11:45:07-07:00

In this paper we propose an energy dissipation mechanism that is completely reliant on changes in the aggregation state of the phycobilisome light-harvesting antenna components. All photosynthetic organisms regulate the efficiency of excitation energy transfer (EET) to fit light energy supply to biochemical demands. Not many do this to the...



Mechanical constraint from growing jaw facilitates mammalian dental diversity [Evolution]

2017-08-14T11:45:07-07:00

Much of the basic information about individual organ development comes from studies using model species. Whereas conservation of gene regulatory networks across higher taxa supports generalizations made from a limited number of species, generality of mechanistic inferences remains to be tested in tissue culture systems. Here, using mammalian tooth explants...



Multiplex, quantitative cellular analysis in large tissue volumes with clearing-enhanced 3D microscopy (Ce3D) [Immunology and Inflammation]

2017-08-14T11:45:07-07:00

Organ homeostasis, cellular differentiation, signal relay, and in situ function all depend on the spatial organization of cells in complex tissues. For this reason, comprehensive, high-resolution mapping of cell positioning, phenotypic identity, and functional state in the context of macroscale tissue structure is critical to a deeper understanding of diverse...



Feedback amplification loop drives malignant growth in epithelial tissues [Genetics]

2017-08-14T11:45:08-07:00

Interactions between cells bearing oncogenic mutations and the surrounding microenvironment, and cooperation between clonally distinct cell populations, can contribute to the growth and malignancy of epithelial tumors. The genetic techniques available in Drosophila have contributed to identify important roles of the TNF-α ligand Eiger and mitogenic molecules in mediating these...



Fission yeast myosin Myo2 is down-regulated in actin affinity by light chain phosphorylation [Biochemistry]

2017-08-14T11:45:08-07:00

Studies in fission yeast Schizosaccharomyces pombe have provided the basis for the most advanced models of the dynamics of the cytokinetic contractile ring. Myo2, a class-II myosin, is the major source of tension in the contractile ring, but how Myo2 is anchored and regulated to produce force is poorly understood....



Reducing posttreatment relapse in cleft lip palatal expansion using an inȷectable estrogen-nanodiamond hydrogel [Engineering]

2017-08-14T11:45:08-07:00

Patients with cleft lip and/or palate (CLP), who undergo numerous medical interventions from infancy, can suffer from lifelong debilitation caused by underdeveloped maxillae. Conventional treatment approaches use maxillary expansion techniques to develop normal speech, achieve functional occlusion for nutrition intake, and improve esthetics. However, as patients with CLP congenitally lack...



Separate mesocortical and mesolimbic pathways encode effort and reward learning signals [Psychological and Cognitive Sciences]

2017-08-14T11:45:08-07:00

Optimal decision making mandates organisms learn the relevant features of choice options. Likewise, knowing how much effort we should expend can assume paramount importance. A mesolimbic network supports reward learning, but it is unclear whether other choice features, such as effort learning, rely on this same network. Using computational fMRI,...



Stochastic feeding dynamics arise from the need for information and energy [Neuroscience]

2017-08-11T12:24:19-07:00

Animals regulate their food intake in response to the available level of food. Recent observations of feeding dynamics in small animals showed feeding patterns of bursts and pauses, but their function is unknown. Here, we present a data-driven decision-theoretical model of feeding in Caenorhabditis elegans. Our central assumption is that...



Oxidation of alkyl benzenes by a flavin photooxidation catalyst on nanostructured metal-oxide films [Chemistry]

2017-08-11T12:24:19-07:00

We describe here a surface-bound, oxide-based procedure for the photooxidation of a family of aromatic hydrocarbons by a phosphate-bearing flavin mononucleotide (FMN) photocatalyst on high surface area metal-oxide films.



Anomalous relaxation kinetics and charge-density-wave correlations in underdoped BaPb1-xBixO3 [Physics]

2017-08-08T07:45:11-07:00

Superconductivity often emerges in proximity of other symmetry-breaking ground states, such as antiferromagnetism or charge-density-wave (CDW) order. However, the subtle interrelation of these phases remains poorly understood, and in some cases even the existence of short-range correlations for superconducting compositions is uncertain. In such circumstances, ultrafast experiments can provide new...



Arc restores juvenile plasticity in adult mouse visual cortex [Neuroscience]

2017-08-08T07:45:11-07:00

The molecular basis for the decline in experience-dependent neural plasticity over age remains poorly understood. In visual cortex, the robust plasticity induced in juvenile mice by brief monocular deprivation during the critical period is abrogated by genetic deletion of Arc, an activity-dependent regulator of excitatory synaptic modification. Here, we report...



Asymmetric percolation drives a double transition in sexual contact networks [Population Biology]

2017-08-08T07:45:12-07:00

Zika virus (ZIKV) exhibits unique transmission dynamics in that it is concurrently spread by a mosquito vector and through sexual contact. Due to the highly asymmetric durations of infectiousness between males and females—it is estimated that males are infectious for periods up to 10 times longer than females—we show that...



Beyond icosahedral symmetry in packings of proteins in spherical shells [Biophysics and Computational Biology]

2017-08-08T07:45:12-07:00

The formation of quasi-spherical cages from protein building blocks is a remarkable self-assembly process in many natural systems, where a small number of elementary building blocks are assembled to build a highly symmetric icosahedral cage. In turn, this has inspired synthetic biologists to design de novo protein cages. We use...



Antibiotic susceptibility testing in less than 30 min using direct single-cell imaging [Microbiology]

2017-08-08T07:45:13-07:00

The emergence and spread of antibiotic-resistant bacteria are aggravated by incorrect prescription and use of antibiotics. A core problem is that there is no sufficiently fast diagnostic test to guide correct antibiotic prescription at the point of care. Here, we investigate if it is possible to develop a point-of-care susceptibility...



Noradrenergic activation of the basolateral amygdala maintains hippocampus-dependent accuracy of remote memory [Neuroscience]

2017-08-08T07:45:13-07:00

Emotional enhancement of memory by noradrenergic mechanisms is well-described, but the long-term consequences of such enhancement are poorly understood. Over time, memory traces are thought to undergo a neural reorganization, that is, a systems consolidation, during which they are, at least partly, transferred from the hippocampus to neocortical networks. This...



MicroRNA-mediated disruption of dendritogenesis during a critical period of development influences cognitive capacity later in life [Neuroscience]

2017-08-08T07:45:13-07:00

The prenatal period of cortical development is important for the establishment of neural circuitry and functional connectivity of the brain; however, the molecular mechanisms underlying this process remain unclear. Here we report that disruption of the actin–cytoskeletal network in the developing mouse prefrontal cortex alters dendritic morphogenesis and synapse formation,...



Landowner behavior can determine the success of conservation strategies for ecosystem migration under sea-level rise [Sustainability Science]

2017-08-08T07:45:13-07:00

The human aspects of conservation are often overlooked but will be critical for identifying strategies for biological conservation in the face of climate change. We surveyed the behavioral intentions of coastal landowners with respect to various conservation strategies aimed at facilitating ecosystem migration for tidal marshes. We found that several...



Alignment of the protein substrate hairpin along the SecA two-helix finger primes protein transport in Escherichia coli [Biophysics and Computational Biology]

2017-08-10T11:47:10-07:00

A conserved hairpin-like structure comprised of a signal peptide and early mature region initiates protein transport across the SecY or Sec61α channel in Bacteria or Archaea and Eukarya, respectively. When and how this initiator substrate hairpin forms remains a mystery. Here, we have used the bacterial SecA ATPase motor protein...



Accurate RNA consensus sequencing for high-fidelity detection of transcriptional mutagenesis-induced epimutations [Genetics]

2017-08-10T11:47:10-07:00

Transcriptional mutagenesis (TM) due to misincorporation during RNA transcription can result in mutant RNAs, or epimutations, that generate proteins with altered properties. TM has long been hypothesized to play a role in aging, cancer, and viral and bacterial evolution. However, inadequate methodologies have limited progress in elucidating a causal association....



On the mechanism of long-range orientational order of fibroblasts [Cell Biology]

2017-08-07T11:52:21-07:00

Long-range alignment ordering of fibroblasts have been observed in the vicinity of cancerous tumors and can be recapitulated with in vitro experiments. However, the mechanisms driving their ordering are not understood. Here, we show that local collision-driven nematic alignment interactions among fibroblasts are insufficient to explain observed long-range alignment. One...



Profile of Peidong Yang [Profiles]

2017-08-07T11:52:22-07:00

In the fall of 2015, Peidong Yang, professor of chemistry at the University of California, Berkeley, received a phone call from the MacArthur Foundation. The caller asked if Yang was alone. Having just finished his lunch, Yang hurried to his office. The caller identified himself as the director of the...



Chaperonin GroEL accelerates protofibril formation and decorates fibrils of the Het-s prion protein [Biophysics and Computational Biology]

2017-08-07T11:52:22-07:00

We have studied the interaction of the prototypical chaperonin GroEL with the prion domain of the Het-s protein using solution and solid-state NMR, electron and atomic force microscopies, and EPR. While GroEL accelerates Het-s protofibril formation by several orders of magnitude, the rate of appearance of fibrils is reduced. GroEL...



3.3 A structure of Niemann-Pick C1 protein reveals insights into the function of the C-terminal luminal domain in cholesterol transport [Biophysics and Computational Biology]

2017-08-07T11:52:23-07:00

Niemann–Pick C1 (NPC1) and NPC2 proteins are indispensable for the export of LDL-derived cholesterol from late endosomes. Mutations in these proteins result in Niemann–Pick type C disease, a lysosomal storage disease. Despite recent reports of the NPC1 structure depicting its overall architecture, the function of its C-terminal luminal domain (CTD)...



Functional New World monkey oxytocin forms elicit an altered signaling profile and promotes parental care in rats [Anthropology]

2017-08-07T11:52:23-07:00

The neurohormone oxytocin is a key player in the modulation of reproductive and social behavioral traits, such as parental care. Recently, a correlation between different forms of oxytocin and behavioral phenotypes has been described in the New World Monkeys (NWMs). Here, we demonstrate that, compared with the Leu8OXT found in...



Aquaporins facilitate hydrogen peroxide entry into guard cells to mediate ABA- and pathogen-triggered stomatal closure [Plant Biology]

2017-08-07T11:52:23-07:00

Stomatal movements are crucial for the control of plant water status and protection against pathogens. Assays on epidermal peels revealed that, similar to abscisic acid (ABA), pathogen-associated molecular pattern (PAMP) flg22 requires the AtPIP2;1 aquaporin to induce stomatal closure. Flg22 also induced an increase in osmotic water permeability (Pf) of...



Structural insights into the catalytic mechanism of a sacrificial sulfur insertase of the N-type ATP pyrophosphatase family, LarE [Biophysics and Computational Biology]

2017-08-07T11:52:24-07:00

The lar operon in Lactobacillus plantarum encodes five Lar proteins (LarA/B/C/D/E) that collaboratively synthesize and incorporate a niacin-derived Ni-containing cofactor into LarA, an Ni-dependent lactate racemase. Previous studies have established that two molecules of LarE catalyze successive thiolation reactions by donating the sulfur atom of their exclusive cysteine residues to...



Dual-reporter SERS-based biomolecular assay with reduced false-positive signals [Applied Physical Sciences]

2017-08-07T11:52:24-07:00

We present a sensitive and quantitative protein detection assay that can efficiently distinguish between specific and nonspecific target binding. Our technique combines dual affinity reagents with surface-enhanced Raman spectroscopy (SERS) and chemometric analysis. We link one Raman reporter-tagged affinity reagent to gold nanoparticles and another to a gold film, such...



Identification of the Tau phosphorylation pattern that drives its aggregation [Biochemistry]

2017-08-07T11:52:24-07:00

Determining the functional relationship between Tau phosphorylation and aggregation has proven a challenge owing to the multiple potential phosphorylation sites and their clustering in the Tau sequence. We use here in vitro kinase assays combined with NMR spectroscopy as an analytical tool to generate well-characterized phosphorylated Tau samples and show...



Molecularly targeted drug combinations demonstrate selective effectiveness for myeloid- and lymphoid-derived hematologic malignancies [Medical Sciences]

2017-08-07T11:52:25-07:00

Translating the genetic and epigenetic heterogeneity underlying human cancers into therapeutic strategies is an ongoing challenge. Large-scale sequencing efforts have uncovered a spectrum of mutations in many hematologic malignancies, including acute myeloid leukemia (AML), suggesting that combinations of agents will be required to treat these diseases effectively. Combinatorial approaches will...



Phosphorylation of serine96 of histidine-rich calcium-binding protein by the Fam20C kinase functions to prevent cardiac arrhythmia [Biochemistry]

2017-08-07T11:52:25-07:00

Precise Ca cycling through the sarcoplasmic reticulum (SR), a Ca storage organelle, is critical for proper cardiac muscle function. This cycling initially involves SR release of Ca via the ryanodine receptor, which is regulated by its interacting proteins junctin and triadin. The sarco/endoplasmic reticulum Ca ATPase (SERCA) pump then refills...



Electrical conductivity of SiO2 at extreme conditions and planetary dynamos [Earth, Atmospheric, and Planetary Sciences]

2017-08-07T11:52:26-07:00

Ab intio molecular dynamics simulations show that the electrical conductivity of liquid SiO2 is semimetallic at the conditions of the deep molten mantle of early Earth and super-Earths, raising the possibility of silicate dynamos in these bodies. Whereas the electrical conductivity increases uniformly with increasing temperature, it depends nonmonotonically on...



Permeability transition in human mitochondria persists in the absence of peripheral stalk subunits of ATP synthase [Biochemistry]

2017-08-07T11:52:26-07:00

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



Air-quality implications of widespread adoption of cool roofs on ozone and particulate matter in southern California [Sustainability Science]

2017-08-07T11:52:27-07:00

The installation of roofing materials with increased solar reflectance (i.e., “cool roofs”) can mitigate the urban heat island effect and reduce energy use. In addition, meteorological changes, along with the possibility of enhanced UV reflection from these surfaces, can have complex impacts on ozone and PM2.5 concentrations. We aim to...



Profile of Nahum Sonenberg [Profiles]

2017-08-07T11:52:27-07:00

Five years after the final shots of World War II rang out, a child and his father stood on the coast of the Mediterranean Sea. From their vantage point in a cemetery in the town of Jaffa, Israel, the boy gazed across the sea and envisioned stepping onto the sands...



Electrocatalytic hydrogen evolution reaction activity comparable to platinum exhibited by the Ni/Ni(OH)2/graphite electrode [Chemistry]

2017-08-07T11:52:27-07:00

Electrochemical dual-pulse plating with sequential galvanostatic and potentiostatic pulses has been used to fabricate an electrocatalytically active Ni/Ni(OH)2/graphite electrode. This electrode design strategy to generate the Ni/Ni(OH)2 interface on graphite from Ni deposits is promising for electrochemical applications and has been used by us for hydrogen generation. The synergetic effect...



Climate matching drives spread rate but not establishment success in recent unintentional bird introductions [Ecology]

2017-08-07T11:52:28-07:00

Understanding factors driving successful invasions is one of the cornerstones of invasion biology. Bird invasions have been frequently used as study models, and the foundation of current knowledge largely relies on species purposefully introduced during the 19th and early 20th centuries in countries colonized by Europeans. However, the profile of...



Effects of maternal investment, temperament, and cognition on guide dog success [Psychological and Cognitive Sciences]

2017-08-07T11:52:28-07:00

A continuing debate in studies of social development in both humans and other animals is the extent to which early life experiences affect adult behavior. Also unclear are the relative contributions of cognitive skills (“intelligence”) and temperament for successful outcomes. Guide dogs are particularly suited to research on these questions....



Inferring patterns of folktale diffusion using genomic data [Anthropology]

2017-08-07T11:52:28-07:00

Observable patterns of cultural variation are consistently intertwined with demic movements, cultural diffusion, and adaptation to different ecological contexts [Cavalli-Sforza and Feldman (1981) Cultural Transmission and Evolution: A Quantitative Approach; Boyd and Richerson (1985) Culture and the Evolutionary Process]. The quantitative study of gene–culture coevolution has focused in particular on...



Redox variations in Mauna Kea lavas, the oxygen fugacity of the Hawaiian plume, and the role of volcanic gases in Earth’s oxygenation [Earth, Atmospheric, and Planetary Sciences]

2017-08-07T11:52:28-07:00

The behavior of C, H, and S in the solid Earth depends on their oxidation states, which are related to oxygen fugacity (fO2). Volcanic degassing is a source of these elements to Earth’s surface; therefore, variations in mantle fO2 may influence the fO2 at Earth’s surface. However, degassing can impact...



Early history of Neanderthals and Denisovans [Anthropology]

2017-08-07T11:52:29-07:00

Extensive DNA sequence data have made it possible to reconstruct human evolutionary history in unprecedented detail. We introduce a method to study the past several hundred thousand years. Our results show that (i) the Neanderthal–Denisovan lineage declined to a small size just after separating from the modern lineage, (ii) Neanderthals...



Ancient DNA reveals the Arctic origin of Viking Age cod from Haithabu, Germany [Anthropology]

2017-08-07T11:52:29-07:00

Knowledge of the range and chronology of historic trade and long-distance transport of natural resources is essential for determining the impacts of past human activities on marine environments. However, the specific biological sources of imported fauna are often difficult to identify, in particular if species have a wide spatial distribution...



Molecular basis for the substrate specificity of quorum signal synthases [Biochemistry]

2017-08-07T11:52:29-07:00

In several Proteobacteria, LuxI-type enzymes catalyze the biosynthesis of acyl–homoserine lactones (AHL) signals using S-adenosyl–l-methionine and either cellular acyl carrier protein (ACP)-coupled fatty acids or CoA–aryl/acyl moieties as progenitors. Little is known about the molecular mechanism of signal biosynthesis, the basis for substrate specificity, or the rationale for donor specificity...



Emergence of a global science-business initiative for ocean stewardship [Sustainability Science]

2017-08-07T11:52:29-07:00

The ocean represents a fundamental source of micronutrients and protein for a growing world population. Seafood is a highly traded and sought after commodity on international markets, and is critically dependent on healthy marine ecosystems. A global trend of wild stocks being overfished and in decline, as well as multiple...



Stress promotes generalization of older but not recent threat memories [Psychological and Cognitive Sciences]

2017-08-07T11:52:29-07:00

Stress broadly affects the ability to regulate emotions and may contribute to generalization of threat-related behaviors to harmless stimuli. Behavioral generalization also tends to increase over time as memory precision for recent events gives way to more gist-like representations. Thus, acute stress coupled with a delay in time from a...



Organotypic models of type III interferon-mediated protection from Zika virus infections at the maternal-fetal interface [Microbiology]

2017-08-07T11:52:18-07:00

Protecting the fetus from the hematogenous spread of viruses requires multifaceted layers of protection and relies heavily on trophoblasts, the fetal-derived cells that comprise the placental barrier. We showed previously that trophoblasts isolated from full-term placentas resist infection by diverse viruses, including Zika virus (ZIKV), and transfer this resistance to...



Cytotoxic protein from the mushroom Coprinus comatus possesses a unique mode for glycan binding and specificity [Biochemistry]

2017-08-07T11:52:18-07:00

Glycans possess significant chemical diversity; glycan binding proteins (GBPs) recognize specific glycans to translate their structures to functions in various physiological and pathological processes. Therefore, the discovery and characterization of novel GBPs and characterization of glycan–GBP interactions are significant to provide potential targets for therapeutic intervention of many diseases. Here,...



Sustainability in an urbanizing planet [Introductions]

2017-08-07T11:52:18-07:00

Sustainability science is use-inspired fundamental research that links knowledge to action such that meeting the needs of society can be balanced with sustaining the life support systems of the planet (1, 2). Nowhere is this action-oriented research needed more than in urban areas that are now home to more than...



Origins of coevolution between residues distant in protein 3D structures [Biophysics and Computational Biology]

2017-08-07T11:52:18-07:00

Residue pairs that directly coevolve in protein families are generally close in protein 3D structures. Here we study the exceptions to this general trend—directly coevolving residue pairs that are distant in protein structures—to determine the origins of evolutionary pressure on spatially distant residues and to understand the sources of error...



Hippocampal maturity promotes memory distinctiveness in childhood and adolescence [Psychological and Cognitive Sciences]

2017-08-07T11:52:19-07:00

Adaptive learning systems need to meet two complementary and partially conflicting goals: detecting regularities in the world versus remembering specific events. The hippocampus (HC) keeps a fine balance between computations that extract commonalities of incoming information (i.e., pattern completion) and computations that enable encoding of highly similar events into unique...



Bilingual infants control their languages as they listen [Psychological and Cognitive Sciences]

2017-08-07T11:52:19-07:00

Infants growing up in bilingual homes learn two languages simultaneously without apparent confusion or delay. However, the mechanisms that support this remarkable achievement remain unclear. Here, we demonstrate that infants use language-control mechanisms to preferentially activate the currently heard language during listening. In a naturalistic eye-tracking procedure, bilingual infants were...



Lampreys, the jawless vertebrates, contain only two ParaHox gene clusters [Evolution]

2017-08-07T11:52:19-07:00

ParaHox genes (Gsx, Pdx, and Cdx) are an ancient family of developmental genes closely related to the Hox genes. They play critical roles in the patterning of brain and gut. The basal chordate, amphioxus, contains a single ParaHox cluster comprising one member of each family, whereas nonteleost jawed vertebrates contain...



CRISPR-Cas9 vectors for genome editing and host engineering in the baculovirus-insect cell system [Applied Biological Sciences]

2017-08-07T11:52:20-07:00

The baculovirus–insect cell system (BICS) has been widely used to produce many different recombinant proteins for basic research and is being used to produce several biologics approved for use in human or veterinary medicine. Early BICS were technically complex and constrained by the relatively primordial nature of insect cell protein...