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A long-standing topic of interest in human neurosciences is the understanding of the neurobiology underlying human cognition. Less commonly considered is to what extent such systems may be shared with other species. We examined individual variation in brain connectivity in the context of cognitive abilities in chimpanzees (n = 45) and humans in search of a conserved link between cognition and brain connectivity across the two species. Cognitive scores were assessed on a variety of behavioral tasks using chimpanzee- and human-specific cognitive test batteries, measuring aspects of cognition related to relational reasoning, processing speed, and problem solving in both species. We show that chimpanzees scoring higher on such cognitive skills display relatively strong connectivity among brain networks also associated with comparable cognitive abilities in the human group. We also identified divergence in brain networks that serve specialized functions across humans and chimpanzees, such as stronger language connectivity in humans and relatively more prominent connectivity between regions related to spatial working memory in chimpanzees. Our findings suggest that core neural systems of cognition may have evolved before the divergence of chimpanzees and humans, along with potential differential investments in other brain networks relating to specific functional specializations between the two species. [ABSTRACT FROM AUTHOR]

A thorough understanding of the circadian clock requires qualitative evaluation of circadian clock gene expression. Thus far, no simple and effective method for detecting human clock gene expression has become available. This limitation has greatly hampered our understanding of human circadian rhythm. Here we report a convenient, reliable, and less invasive method for detecting human clock gene expression using biopsy samples of hair follicle cells from the head or chin. We show that the circadian phase of clock gene expression in hair follicle cells accurately reflects that of individual behavioral rhythms, demonstrating that this strategy is appropriate for evaluating the human peripheral circadian clock. Furthermore, using this method, we indicate that rotating shift workers suffer from a serious time lag between circadian gene expression rhythms and lifestyle. Qualitative evaluation of clock gene expression in hair follicle cells, therefore, may be an effective approach for studying the human circadian clock in the clinical setting. circadian rhythm | clock gene | shift work | jet lag | chronotherapy doi/ 10.1073/pnas.10038781071

In addition to its role in shifting the line of sight, the oculomotor system is also involved in the covert orienting of visuospatial attention. Causal evidence supporting this premotor theory of attention, or oculomotor readiness hypothesis, comes from the effect of subsaccadic threshold stimulation of the oculomotor system on behavior and neural activity in the absence of evoked saccades, which parallels the effects of covert attention. Here, by recording neck-muscle activity from monkeys and systematically titrating the level of stimulation current delivered to the frontal eye fields (FEF), we show that such subsaccadic stimulation is not divorced from immediate motor output but instead evokes neck-muscle responses at latencies that approach the minimal conduction time to the motor periphery. On average, neck-muscle thresholds were ~25% lower than saccade thresholds, and this difference is larger for FEF sites associated with progressively larger saccades. Importantly, we commonly observed lower neck-muscle thresholds even at sites evoking saccades [less than or equal to] 5[degrees] in magnitude, although such small saccades are not associated with head motion. Neck-muscle thresholds compare well with the current levels used in previous studies to influence behavior or neural activity through activation of FEF neurons feeding back to extrastriate cortex. Our results complement this previous work by suggesting that the neurobiologic substrate that covertly orients visuospatial attention shares this command with head premotor circuits in the brainstem, culminating with recruitment in the motor periphery. eye--head gaze shifts | oculomotor | visuospatial attention doi/10.1073/pnas.0911902107

Archaeological excavations at a U-shaped pyramid in the northern Lake Titicaca Basin of Peru have documented a continuous 5-m-deep stratigraphic sequence of metalworking remains. The sequence begins in the first millennium AD and ends in the Spanish Colonial period ca. AD 1600. The earliest dates associated with silver production are 1960 [+ or -] 40 BP (2-sigma cal. 40 BC to AD 120) and 1870 [+ or -] 40 BP (2-sigma cal. AD 60 to 240) representing the oldest known silver smelting in South America. Scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS) analysis of production debris indicate a complex, multistage, high temperature technology for producing silver throughout the archaeological sequence. These data hold significant theoretical implications including the following: (i) silver production occurred before the development of the first southern Andean state of Tiwanaku, (ii) the location and process of silverworking remained consistent for 1,500 years even though political control of the area cycled between expansionist states and smaller chiefly polities, and (iii) that U-shaped structures were the location of ceremonial, residential, and industrial activities. Andes | craft specialization | metallury doi/ 10.1073/pnas.0907733106

To what extent genotypic differences translate to phenotypic variation remains a poorly understood issue of paramount importance for several cornerstone concepts of microbiology including the species definition. Here, we take advantage of the completed genomic sequences, expressed proteomic profiles, and physiological studies of 10 closely related Shewanella strains and species to provide quantitative insights into this issue. Our analyses revealed that, despite extensive horizontal gene transfer within these genomes, the genotypic and phenotypic similarities among the organisms were generally predictable from their evolutionary relatedness. The power of the predictions depended on the degree of ecological specialization of the organisms evaluated. Using the gradient of evolutionary relatedness formed by these genomes, we were able to partly isolate the effect of ecology from that of evolutionary divergence and to rank the different cellular functions in terms of their rates of evolution. Our ranking also revealed that whole-cell protein expression differences among these organisms, when the organisms were grown under identical conditions, were relatively larger than differences at the genome level, suggesting that similarity in gene regulation and expression should constitute another important parameter for (new) species description. Collectively, our results provide important new information toward beginning a systems-level understanding of bacterial species and genera. comparative genomics | evolution | proteomics | speciation | phenotype

Inappropriate activation of the Hedgehog (Hh) signaling pathway has been implicated in a diverse spectrum of cancers, and its pharmacological blockade has emerged as an anti-tumor strategy. While nearly all known Hh pathway antagonists target the transmembrane protein Smoothened (Smo), small molecules that suppress downstream effectors could more comprehensively remediate Hh pathway-dependent tumors. We report here four Hh pathway antagonists that are epistatic to the nucleocytoplasmic regulator Suppressor of Fused [Su(fu)], including two that can inhibit Hh target gene expression induced by overexpression of the Gli transcription factors. Each inhibitor has a unique mechanism of action, and their phenotypes reveal that Gli processing, Gli activation, and primary cilia formation are pharmacologically targetable. We further establish the ability of certain compounds to block the proliferation of cerebellar granule neuron precursors expressing an oncogenic form of Smo, and we demonstrate that Hh pathway inhibitors can have tissue-specific activities. These antagonists therefore constitute a valuable set of chemical tools for interrogating downstream Hh signaling mechanisms and for developing chemotherapies against Hh pathway-related cancers. antagonist | cancer | Gli | medulloblastoma

Wheat is a widely grown food crop that suffers major yield losses due to attack by pests and pathogens. A better understanding of biotic stress responses in wheat is thus of major importance. The recently assembled bread wheat genome coupled with extensive transcriptomic resources provides unprecedented new opportunities to investigate responses to pathogen challenge. Here, we analyze gene coexpression networks to identify modules showing consistent induction in response to pathogen exposure. Within the top pathogen-induced modules, we identify multiple clusters of physically adjacent genes that correspond to six pathogen-induced biosynthetic pathways that share a common regulatory network. Functional analysis reveals that these pathways, all of which are encoded by biosynthetic gene clusters, produce various different classes of compounds--namely, flavonoids, diterpenes, and triterpenes, including the defense-related compound ellarinacin. Through comparative genomics, we also identify associations with the known rice phytoalexins momilactones, as well as with a defense-related gene cluster in the grass model plant Brachypodium distachyon. Our results significantly advance the understanding of chemical defenses in wheat and open up avenues for enhancing disease resistance in this agriculturally important crop. They also exemplify the power of transcriptional networks to discover the biosynthesis of chemical defenses in plants with large, complex genomes. [ABSTRACT FROM AUTHOR]

Mechanically interlocked compounds, such as bistable catenanes and bistable rotaxanes, have been used to bring about actuation in nanoelectromechanical systems (NEMS) and molecular electronic devices (MEDs). The elaboration of the structural features of such rotaxanes into macromolecular materials might allow the utilization of molecular motion to impact their bulk properties. We report here the synthesis and characterization of polymers that contain electron-donating 1,5-dioxynaphthalene (DNP) units encircled by cyclobis(paraquat-p-phenylene) ([CBPQT.sup.4+]), a [tau] electron-accepting tetracationic cyclophane, synthesized by using the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC). The polyrotaxanes adopt a well defined 'folded' secondary structure by virtue of the judicious design of two DNP-containing monomers with different binding affinities for [CBPQT.sup.4+]. This efficient approach to the preparation of polyrotaxanes, taken alongside the initial investigations of their chemical properties, sets the stage for the preparation of a previously undescribed class of macromolecular architectures. click chemistry | foldamers | polymers | supramolecular chemistry | rotaxanes

Vascular smooth muscle cells (SMCs) have been implicated in the pathophysiology of stroke, the third most common cause of death and the leading cause of long-term neurological disability in the world. However, there is little insight into the underlying cellular pathways that link SMC function to brain ischemia susceptibility. Using a hitherto uncharacterized knockout mouse model of Notch 3, a Notch signaling receptor paralogue highly expressed in vascular SMCs, we uncover a striking susceptibility to ischemic stroke upon challenge. Cellular and molecular analyses of vascular SMCs derived from these animals associate Notch 3 activity to the expression of specific gene targets, whereas genetic rescue experiments unambiguously link Notch 3 function in vessels to the ischemic phenotype. ischemia | Notch3 | vascular smooth muscle | CADASIL

Microorganisms facilitate the formation of a wide range of minerals that have unique physical and chemical properties as well as morphologies that are not produced by abiotic processes. Here, we report the production of an extensive extracellular network of filamentous, arsenic-sulfide (As-S) nanotubes (20-100 nm in diameter by [approximately not equal to]30 [micro]m in length) by the dissimilatory metal-reducing bacterium Shewanella sp. HN-41. The As-S nanotubes, formed via the reduction of As(V) and [S.sub.2][O.sub.3.sup.2-], were initially amorphous [As.sub.2][S.sub.3] but evolved with increasing incubation time toward polycrystalline phases of the chalcogenide minerals realgar (ASS) and duranusite ([As.sub.4]S). Upon maturation, the As-S nanotubes behaved as metals and semiconductors in terms of their electrical and photoconductive properties, respectively. The As-S nanotubes produced by Shewanella may provide useful materials for novel nano- and opto-electronic devices.

In humans, the wakeful resting condition is characterized by a default mode of brain function involving high levels of activity within a functionally connected network of brain regions. This network has recently been implicated in mental self-projection into the past, the future, or another individual's perspective. Here we use [[sup.18]F]-fluorodeoxyglucose positron emission tomography imaging to assess resting-state brain activity in our closest living relative, the chimpanzee, as a potential window onto their mental world and compare these results with those of a human sample. We find that, like humans, chimpanzees show high levels of activity within default mode areas, including medial prefrontal and medial parietal cortex. Chimpanzees differ from our human sample in showing higher levels of activity in ventromedial prefrontal cortex and lower levels of activity in left-sided cortical areas involved in language and conceptual processing in humans. Our results raise the possibility that the resting state of chimpanzees involves emotionally laden episodic memory retrieval and some level of mental self-projection, albeit in the absence of language and conceptual processing. comparative cognition | neuroimaging | default mode

Wild barley (Hordeum spontaneum) represents a significant genetic resource for crop improvement in barley (Hordeum vulgare) and for the study of the evolution and domestication of plant populations. The Isa gene from barley has a putative role in plant defense. This gene encodes a bifunctional [alpha]-amylase/subtilisin inhibitor that inhibits the bacterial serine protease subtilisin, fungal xylanase, and the plant's own [alpha]-amylase. The inhibition of plant [alpha]-amylases suggests this protein may also be important for grain quality from a human perspective. We identified 16 SNPs in the coding region of the Isa locus of 178 wild barley accessions from eight climatically divergent sites across Israel. The pattern of SNPs suggested a large number of recombination events within this gene, indicating that the Iow-outcrossing rate of wild barley is not a barrier to recombinant haplotypes becoming established in the population. Seven amino acid substitutions were present in the coding region. Genetic diversity for each population was calculated by using Nei's diversity index, and a Spearman rank correlation was carried out to test the association between gene diversity and 16 ecogeographical factors. Highly significant correlations were found between diversity at the Isa locus and key water variables, evaporation, rainfall, humidity, and latitude. The pattern of association suggests selective sweeps in the wetter climates, with resulting low diversity and weaker selection or diversifying selection in the dryer climates resulting in much higher diversity. climatic selection | crop improvement | Hordeum spontaneum | Isa molecular polymorphism

Recent analyses of global pig populations revealed strict correlations between mtDNA phylogenies and geographic locations. An exception was the monophyletic 'Pacific clade' (PC) of pigs not previously linked to any specific location. We examined mtDNA sequences of two varieties of Vanuatu sacred pigs, the male pseudohermaphroditic Narave from the island of Malo (n = 9) and the hairless Kapia from the island of Tanna (n = 9), as well as control pigs (n = 21) from the islands of Malo, Tanna, and Epi and compared them with GenBank sequences to determine (11 the distribution of PC and introduced domestic lineages within Vanuatu, (ii) relationship between the Narave and Kapia, and (iii) origin of the PC. All of the Narave share two PC mtDNA sequences, one of which matches the sequence of a Narave collected in 1927, consistent with an unbroken maternal descent of these intersex pigs from the original pigs brought to Vanuatu 3,200 years ago. One-third of the Kapia share a single PC lineage also found in the Narave. The remaining Kapia lineages are associated with recently introduced, globally distributed domestic breeds. The predominant Narave lineage is also shared with two wild boars from Vietnam. These data suggest that PC pigs were recently domesticated within Southeast Asia and dispersed during the human colonization of Remote Oceania associated with the Lapita cultural complex. More extensive sampling of Southeast Asian wild boar diversity may refine the location of Pacific pig domestication and potentially the proximate homeland of the Lapita cultural complex. mtDNA | Pacific | Remote Oceania | Sus scrofa

The binding of thyroid hormone to the thyroid hormone receptor (TR) mediates important physiological effects. However, the transcriptional effects of TR mediated by the thyroid response element (TRE) cannot explain many actions of thyroid hormone. We postulate that TR can initiate rapid, non-TRE-mediated effects in the cardiovascular system through cross-coupling to the phosphatidylinositol 3-kinase (PI3-kinase)/protein kinase Akt pathway. In vascular endothelial cells, the predominant TR isoform is TR[[alpha].sub.1]. Treatment of endothelial cells with L-3,5,3'-triiodothyronine ([T.sub.3]) increased the association of TR[[alpha].sub.1] with the p85[alpha] subunit of PI3-kinase, leading to the phosphorylation and activation of Akt and endothelial nitric oxide synthase (eNOS). The activation of Akt and eNOS by [T.sub.3] was abolished by the PI3-kinase inhibitors, LY294002 and wortmannin, but not by the transcriptional inhibitor, actinomycin D. To determine the physiological relevance of this PI3-kinase/Akt pathway, we administered [T.sub.3] to mice undergoing transient focal cerebral ischemia. Compared with vehicle, a single bolus infusion of [T.sub.3] rapidly increased Akt activity in the brain, decreased mean blood pressure, reduced cerebral infarct volume, and improved neurological deficit score. These neuroprotective effects of [T.sub.3] were greatly attenuated or absent in [eNOS.sup.-/-] and TR[[alpha].sub.1.sup.-/-][[beta].sup.-/-] mice and were completely abolished in WT mice pretreated with LY294002 or a [T.sub.3] antagonist, NH-3. These findings indicate that the activation of PI3-kinase/Akt pathways can mediate some of the rapid, non-TRE effects of TR and suggest that the activation of Akt and eNOS contributes to some of the acute vasodilatory and neuroprotective effects of thyroid hormone. nitric oxide | phosphatidylinositol 3-kinase | protein kinase Akt | stroke

The development of cardiac hypertrophy is mediated, in part, by increase in NADPH oxidase activity and myocardial oxidative stress. The Rho GTPase, Rac, regulates NADPH oxidase activity through interaction with gp[91.sup.phox] and p[67.sup.phox] (in which 'phox' is phagocyte oxidase). However, it is not known which Rac isoform mediates this effect in the heart. Here we show that Rac1 is critical for generating oxidative stress and producing cardiac hypertrophy in the adult heart. The Rac1 gene was temporally and specifically deleted in adult mouse cardiomyocytes (c-[Rac1.sup.-/-]). Compared with wild-type or Rac1 heterozygous mice, the hearts of c-[Rac1.sup.-/-]mice showed decreased gp[91.sup.phox] and p[67.sup.phox] interaction, NADPH oxidase activity, and myocardial oxidative stress in response to angiotensin II (400 ng/kg per day for 2 weeks) stimulation. This result correlated with decreased myocardial hypertrophy. These results indicate that Rac1 is critical for the hypertrophic response in the heart and suggest that therapies which target myocardial Rac1 may be beneficial in the treatment of cardiac hypertrophy. small G protein | oxidative stress angiotensin II | NADPH oxidase

Multicellular microbial communities are the predominant form of existence for microorganisms in nature. As one of the most primitive social organisms, Myxococcus xanthus has been an ideal model bacterium for studying intercellular interaction and multicellular organization. Through previous genetic and EM studies, various extracellular appendages and matrix components have been found to be involved in the social behavior of M. xanthus, but none of them was directly visualized and analyzed under native conditions. Here, we used atomic force microscopy (AFM) imaging and in vivo force spectroscopy to characterize these cellular structures under native conditions. AFM imaging revealed morphological details on the extracellular ultrastructures at an unprecedented resolution, and in vivo force spectroscopy of live cells in fluid allowed us to nanomechanically characterize extracellular polymeric substances. The findings provide the basis for AFM as a useful tool for investigating microbial-surface ultrastructures and nanomechanical properties under native conditions. force spectroscopy | nonomechanics | bacteria | swarm

The [gamma]-proteobacterium Shewanella oneidensis strain MR-1 is a metabolically versatile organism that can reduce a wide range of organic compounds, metal ions, and radionuclides. Similar to most other sequenced organisms, [approximately equal to] 40% of the predicted ORFs in the S. oneidensis genome were annotated as uncharacterized 'hypothetical' genes. We implemented an integrative approach by using experimental and computational analyses to provide more detailed insight into gene function. Global expression profiles were determined for cells after UV irradiation and under aerobic and suboxic growth conditions. Transcriptomic and proteomic analyses confidently identified 538 hypothetical genes as expressed in S. oneidensis cells both as mRNAs and proteins (33% of all predicted hypothetical proteins). Publicly available analysis tools and databases and the expression data were applied to improve the annotation of these genes. The annotation results were scored by using a seven-category schema that ranked both confidence and precision of the functional assignment. We were able to identify homologs for nearly all of these hypothetical proteins (97%), but could confidently assign exact biochemical functions for only 16 proteins (category 1; 3%). Altogether, computational and experimental evidence provided functional assignments or insights for 240 more genes (categories 2-5; 45%). These functional annotations advance our understanding of genes involved in vital cellular processes, including energy conversion, ion transport, secondary metabolism, and signal transduction. We propose that this integrative approach offers a valuable means to undertake the enormous challenge of characterizing the rapidly growing number of hypothetical proteins with each newly sequenced genome. computational biology |expression analysis | microarrays | proteomics | integrative microbiology

Benzodiazepines exert their effects by binding to multiple subtypes of the GAB[A.sub.A] receptor, the predominant subtypes in the brain being those that contain [[alpha].sub.1]-, [[alpha].sub.2]-, [[alpha].sub.3]-, and [[alpha].sub.5]-subunits. To understand the potentially different roles of these subtypes in the therapeutic and side effects of benzodiazepines, we evaluated GAB[A.sub.A] receptor subtype-preferring compounds in nonhuman primate models predictive of anxiolytic, sedative, motor, subjective, and reinforcing effects of benzodiazepine-type drugs. These compounds included zolpidem, which shows preferential binding to GAB[A.sub.A] receptors containing [[alpha].sub.1]-subunits ([[alpha].sub.1]GAB[A.sub.A] receptors); L-838,417, which shows functional selectivity for [[alpha].sub.2]GAB[A.sub.A], [[alpha].sub.3]GAB[A.sub.A], and [[alpha].sub.5]GAB[A.sub.A] receptors; and nonselective conventional benzodiazepines. The results provide evidence in nonhuman primates that [[alpha].sub.1]GAB[A.sub.A] receptors do not play a key role in the anxiolytic and muscle-relaxant properties of benzodiazepine-type drugs; instead, these effects involve [[alpha].sub.2]GAB[A.sub.A], [[alpha].sub.3]GAB[A.sub.A], and/or [[alpha].sub.5]GAB[A.sub.A] subtypes. Our results also suggest that the [[alpha].sub.1]GAB[A.sub.A] receptor subtype might be critically involved in the subjective, sedative, and motor effects of benzodiazepine-type drugs. In contrast, stimulation of [[alpha].sub.1]GAB[A.sub.A] receptors is sufficient, but not necessary, for mediation of the abuse potential of these drugs. addiction | anxiety

Large, intense forest fires, along with their causes and their consequences, have become important political and social issues. In the United States, however, there is no comprehensive policy to deal [...]

Cognitive control requires the resolution of interference among competing and potentially conflicting representations. Such conflict can emerge at different points between stimulus input and response generation, with the net effect being that of compromising performance. The goal of this article was to dissociate the neural mechanisms underlying different sources of conflict to elucidate the architecture of the neural systems that implement cognitive control. By using functional magnetic resonance imaging and a verbal working memory task (item recognition), we examined brain activity related to two kinds of conflict with comparable behavioral consequences. In a trial of our item-recognition task, participants saw four letters, followed by a retention interval, and a probe letter that did or did not match one of the letters held in working memory (positive probe and negative probe, respectively). On some trials, conflict arose solely because of the current negative probe having a high familiarity, due to its membership in the immediately preceding trial's target set. On other trials, additional conflict arose because of the current negative probe having also been a positive probe on the immediately preceding trial, producing response-level conflict. Consistent with previous work, conflict due to high familiarity was associated with left prefrontal activation, but not with anterior cingulate activation. The response-conflict condition, when compared with high-familiarity conflict trials, was associated with anterior cingulate cortex activation, but with no additional left prefrontal activation. This double dissociation points to differing contributions of specific cortical areas to cognitive control, which are based on the source of conflict.

Cryo-electron microscopy was exploited to reveal and study the influence of pyruvate dehydrogenase ([E.sub.1]) occupancy on the conformational states of the Saccharomyces cerevisiae pyruvate dehydrogenase complex (PDC). Structures representative of PDC preparations with [approximately equal to] 40% and full [E.sub.1] occupancy were determined after the electron microscopy images from each preparation were classified according to their sizes. The reconstructions derived from two size groups showed that the deposition of the [E.sub.1] molecules associated with the larger complex is, unexpectedly, not icosahedrally arranged, whereas in the smaller complex the [E.sub.1] molecules have an arrangement and architecture similar to their more ordered deposition in the WT bovine kidney PDC. This study also shows that the linker of dihydrolipamide acetyltransferase ([E.sub.2]) that tethers [E.sub.1] to the [E.sub.2] core increases in length from [approximately equal to] 50 to 75 [Angstrom], accounting largely for the size difference of the smaller and larger structures, respectively. Extensive [E.sub.1] occupancy of its 60 [E.sub.2] binding sites favors the extended conformation of the linker associated with the larger complex and appears to be related to the loss of icosahedral symmetry of the [E.sub.1] molecules. However, the presence of a significant fraction of larger molecules also in the WT PDC preparation with low [E.sub.1] occupancy indicates that the conformational variability of the linker contributes to the overall protein dynamics of the PDC and the variable deposition of [E.sub.1]. The flexibility of the complex may enhance the catalytic proficiency of this macromolecular machine by promoting the channeling of the intermediates of catalysis between the active sites.

Decades of air pollution regulation have yielded enormous benefits in the United States, but vehicle emissions remain a climate and public health issue. Studies have quantified the vehicle-related fine particulate matter (PM2.5)-attributable mortality but lack the combination of proper counterfactual scenarios, latest epidemiological evidence, and detailed spatial resolution; all needed to assess the benefits of recent emission reductions. We use this combination to assess PM2.5-attributable health benefits and also assess the climate benefits of on-road emission reductions between 2008 and 2017. We estimate total benefits of $270 (190 to 480) billion in 2017. Vehicle-related PM2.5-attributable deaths decreased from 27,700 in 2008 to 19,800 in 2017; however, had per-mile emission factors remained at 2008 levels, 48,200 deaths would have occurred in 2017. The 74% increase from 27,700 to 48,200 PM2.5-attributable deaths with the same emission factors is due to lower baseline PM2.5 concentrations (+26%), more vehicle miles and fleet composition changes (+22%), higher baseline mortality (+13%), and interactions among these (+12%). Climate benefits were small (3 to 19% of the total). The percent reductions in emissions and PM2.5-attributable deaths were similar despite an opportunity to achieve disproportionately large health benefits by reducing high-impact emissions of passenger light-duty vehicles in urban areas. Increasingly large vehicles and an aging population, increasing mortality, suggest large health benefits in urban areas require more stringent policies. Local policies can be effective because high-impact primary PM2.5 and NH3 emissions disperse little outside metropolitan areas. Complementary national-level policies for NOx are merited because of its substantial impacts--with little spatial variability--and dispersion across states and metropolitan areas. [ABSTRACT FROM AUTHOR]

Ventricular septal defects are common in human infants, but the genetic programs that control ventricular septation are poorly understood. Here we report that mice with a targeted disruption of the cardiovascular basic helix--loop--helix factor (CHF)1/Hey2 gene show isolated ventricular septal defects. These defects result primarily in failure to thrive. Mice often succumbed within the first 3 wk after birth and showed pulmonary and liver congestion. The penetrance of this phenotype varied, depending on genetic background, suggesting the presence of modifier genes. Expression patterns of other cardiac-specific genes were not affected. Of the few animals on a mixed genetic background that survived to adulthood, most developed a cardiomyopathy but did not have ventricular septal defects. Our results indicate that CHF1 plays an important role in regulation of ventricular septation in mammalian heart development and is important for normal myocardial contractility. These mice provide a useful model for the study of the ontogeny and natural history of ventricular septal defects and cardiomyopathy.

Smoothened (Smo), a distant relative of G protein-coupled receptors, mediates Hedgehog (Hh) signaling during embryonic development and can initiate or transmit ligand-independent pathway activation in tumorigenesis. Although the cellular mechanisms that regulate Smo function remain unclear, the direct inhibition of Smo by cyclopamine, a plant-derived steroidal alkaloid, suggests that endogenous small molecules may be involved. Here we demonstrate that SAG, a chlorobenzothiophene-containing Hh pathway agonist, binds to the Smo heptahelical bundle in a manner that antagonizes cyclopamine action. In addition, we have identified four small molecules that directly inhibit Smo activity but are structurally distinct from cyclopamine. Functional and biochemical studies of these compounds provide evidence for the small molecule modulation of Smo through multiple mechanisms and yield insights into the physiological regulation of Smo activity. The mechanistic differences between the Smo antagonists may be useful in the therapeutic manipulation of Hh signaling.

Endothelium-derived nitric oxide (NO) is an important regulator of vascular function. NO is produced by endothelial NO synthase (eNOS) whose function is modulated, in part, by specific protein interactions. By coimmunoprecipitation experiments followed by MS analyses, we identified a human voltage-dependent anion/ cation channel or porin as a binding partner of eNOS. The interaction between porin and eNOS was demonstrated by coimmunoprecipitation studies in nontransfected human endothelial cells and Cos-7 cells transiently transfected with eNOS and porin cDNAs. In vitro binding studies with glutathione S-transferase-porin indicated that porin binds directly to eNOS and that this interaction augmented eNOS activity. The calcium ionophore, A23187, and bradykinin, which are known to activate eNOS, markedly increased porin-eNOS interaction, suggesting a potential role of intracellular [Ca.sup.2+] in mediating this interaction. Theses results indicate that the interaction between a voltage-dependent membrane channel and eNOS may be important for regulating eNOS activity.

The peptide antibiotic ramoplanin inhibits bacterial peptidoglycan (PG) biosynthesis by interrupting late-stage membrane-associated glycosyltransferase reactions catalyzed by the transglycosylase and MurG enzymes. The mechanism of ramoplanin involves sequestration of lipid-anchored PG biosynthesis intermediates, physically occluding these substrates from proper utilization by these enzymes. In this report, we describe the first molecular-level details of the interaction of ramoplanin with PG biosynthesis intermediates. NMR analysis in conjunction with chemical dissection of the PG monomer revealed that the ramoplanin octapeptide D-Hpg-D-Orn-D-alloThr-Hpg-D-Hpg-alloThr-Phe-D-Orn recognizes MurNAc-Ala-[gamma]-D-Glu pyrophosphate, the minimum component of PG capable of high-affinity complexation and fibril formation. Ramoplanin therefore recognizes a PG binding locus different from the N-acyl-D-Ala-D-Ala moiety targeted by vancomycin. Because ramoplanin is structurally less complex than glycopeptide antibiotics such as vancomycin, peptidomimetic chemotherapeutics derived from this recognition sequence may find future use as antibiotics against vancomycin-resistant Enterococcus faecium, methicillin-resistant Staphylococcus aureus, and related pathogens.

The three-dimensional reconstruction of the bovine kidney pyruvate dehydrogenase complex ([M.sub.r] [approximately equal to] 7.8 x [10.sup.6]) comprising about 22 molecules of pyruvate dehydrogenase ([E.sub.1]) and about 6 molecules of dihydrolipoamide dehydrogenase ([E.sub.3]) with its binding protein associated with the 60-subunit dihydrolipoamide acetyltransferase ([E.sub.2]) core provides considerable insight into the structural and functional organization of the largest multienzyme complex known. The structure shows that potentially 60 centers for acetyl-CoA synthesis are organized in sets of three at each of the 20 vertices of the pentagonal dodecahedral core. These centers consist of three [E.sub.1] molecules bound to one [E.sub.2] trimer adjacent to an [E.sub.3] molecule in each of 12 pentagonal openings. The [E.sub.1] components are anchored to the [E.sub.1]-binding domain of the [E.sub.2] subunits through an [approximately equal to] 50-[Angstrom]-long linker. Three of these linkers emanate from the outside edges of the triangular base of the [E.sub.2] trimer and form a cage around its base that may shelter the lipoyl domains and the [E.sub.1] and [E.sub.2] active sites. The docking of the atomic structures of [E.sub.1] and the [E.sub.1] binding and lipoyl domains of [E.sub.2] in the electron microscopy map gives a good fit and indicates that the [E.sub.1] active site is [approximately equal to] 95 [Angstrom] above the base of the trimer. We propose that the lipoyl domains and its tether (swinging arm) rotate about the [E.sub.1]-binding domain of [E.sub.2], which is centrally located 45-50 [Angstrom] from the [E.sub.1], [E.sub.2], and [E.sub.3] active sites, and that the highly flexible breathing core augments the transfer of intermediates between active sites.

Symbiotic nitrogen fixation, the process whereby nitrogen-fixing bacteria enter into associations with plants, provides the major source of nitrogen for the biosphere. Nitrogenase, a bacterial enzyme, catalyzes the reduction of atmospheric dinitrogen to ammonium. In rhizobia-leguminous plant symbioses, the current model of nitrogen transfer from the symbiotic form of the bacteria, called a bacteroid, to the plant is that nitrogenase-generated ammonia diffuses across the bacteroid membrane and is assimilated into amino acids outside of the bacteroid. We purified soybean nodule bacteroids by a procedure that removed contaminating plant proteins and found that alanine was the major nitrogen-containing compound excreted. Bacteroids incubated in the presence of 15[N.sub.2] excreted alanine highly enriched in 15N. The ammonium in these assays neither accumulated significantly nor was enriched in 15N. The results demonstrate that a transport mechanism rather than diffusion functions at this critical step of nitrogen transfer from the bacteroids to the plant host. Alanine may serve only as a transport species, but this would permit physiological separation of the transport of fixed nitrogen from other nitrogen metabolic functions commonly mediated through glutamate.

The treatment of ischemic strokes is limited to prophylactic agents that block the coagulation cascade. Here, we show that cholesterol-lowering agents, 3-hydroxy-3-methylglutaryl (HMG)-CoA reductase inhibitors, protect against cerebral injury by a previously unidentified mechanism involving the selective up-regulation of endothelial NO synthase (eNOS). Prophylactic treatment with HMG-CoA reductase inhibitors augments cerebral blood flow, reduces cerebral infarct size, and improves neurological function in normocholesterolemic mice. The up-regulation of eNOS by HMG-CoA reductase inhibitors is not associated with changes in serum cholesterol levels, but is reversed by cotreatment with L-mevalonate and by the downstream isoprenoid, geranylgeranyl pyrophosphate and not by farnesyl pyrophosphate. The blood flow and neuroprotective effects of HMG-CoA reductase inhibitors are completely absent in eNOS-deficient mice, indicating that enhanced eNOS activity by HMG-CoA reductase inhibitors is the predominant if not the only mechanism by which these agents protect against cerebral injury. Our results suggest that HMG-CoA reductase inhibitors provide a prophylactic treatment strategy for increasing blood flow and reducing brain injury during cerebral ischemia.

Inactivation of the genes involved in DNA mismatch repair is associated with microsatellite instability (MSI) in colorectal cancer. We report that hypermethylation of the 5[prime] CpG island of hMLH1 is found in the majority of sporadic primary colorectal cancers with MSI, and that this methylation was often, but not invariably, associated with loss of hMLH1 protein expression. Such methylation also occurred, but was less common, in MSI - tumors, as well as in MSI+ tumors with known mutations of a mismatch repair gene (MMR). No hypermethylation of hMSH2 was found. Hypermethylation of colorectal cancer cell lines with MSI also was frequently observed, and in such cases, reversal of the methylation with 5-aza-2[prime]-deoxycytidine not only resulted in reexpression of hMLH1 protein, but also in restoration of the MMR capacity in MMR-deficient cell lines. Our results suggest that microsatellite instability in sporadic colorectal cancer often results from epigenetic inactivation of hMLH1 in association with DNA methylation.

The kinetic properties of an adenine DNA methyltransferase involved in cell cycle regulation of Caulobacter crescentus have been elucidated by using defined unmethylated or hemimethylated DNA ([DNA.sub.HM]) substrates. Catalytic efficiency is significantly enhanced with a [DNA.sub.HM] substrate. Biphasic kinetic behavior during methyl incorporation is observed when unmethylated or [DNA.sub.HM] substrates are used, indicating that a step after chemistry limits enzyme turnover and is most likely the release of enzyme from methylated DNA product. The enzyme is thermally inactivated at 30[degrees]C within 20 min; this process is substantially decreased in the presence of saturating concentrations of [DNA.sub.HM], suggesting that the enzyme preferentially binds DNA before S-adenosylmethionine. The activity of the enzyme shows an unusual sensitivity to salt levels, apparently dissociating more rapidly from methylated DNA product as the salt level is decreased. The enzyme acts processively during methylation of specific DNA sequences, indicating a preferred order of product release in which S-adenosylhomocysteine is released from enzyme before fully methylated DNA. The kinetic behavior and activity of the enzyme are consistent with the temporal constraints during the cell cycle-regulated methylation of newly replicated chromosomal DNA.

We pooled data from 10 longitudinal studies of 1,104married couples to test the Vulnerability-Stress-Adaptation (VSA) model of change in relationship satisfaction. Studies contained both spouses' self-reports of neuroticism, attachment anxiety, and attachment avoidance; observationalmeasures of engagement and opposition during problemsolving discussions at baseline; and repeated reports of both spouses' stress and marital satisfaction over several years. Consistent with the VSA model, all three individual and partner qualities predicted changes in marital satisfaction that were mediated by observations of behavior and moderated by both partners' experiences with stress. In contrast to the VSA model, however, rather than accentuating the association between individual differences and behavior, both partners' stress moderated the strength, and even direction, of the association between behavior and changes in marital satisfaction over time. Taken together, these findings indicate that 1) qualities of both couple members shape their behavioral exchanges, 2) these behaviors explain how individuals and their partners' enduring qualities predict relationship satisfaction, and 3) stress experienced by both couple members strongly determines how enduring qualities and behavior predict changes in relationship satisfaction over time. The complex interplay among both partners' enduring qualities, stress, and behavior helps explain why studies may fail to document direct main effects of own and partner enduring qualities and behavior on changes in relationship satisfaction over time. [ABSTRACT FROM AUTHOR]

Infection of mucosal epithelium by papillo-maviruses is responsible for the induction of genital and oral warts and plays a critical role in the development of human cervical and oropharyngeal cancer. We have employed a canine model to develop a systemic vaccine that completely protects against experimentally induced oral mucosal papillomas. The major capsid protein, L1, of canine oral papillo-mavirus (COPV) was expressed in Sf9 insect cells in native conformation. L1 protein, which self-assembled into virus-like particles, was purified on CsCl gradients and injected intradermally into the foot pad of beagles. Vaccinated animals developed circulating antibodies against COPV and became completely resistant to experimental challenge with COPV. Successful immunization was strictly dependent upon native L1 protein conformation and L1 type. Partial protection was achieved with as little as 0.125 ng of L1 protein, and adjuvants appeared useful for prolonging the host immune response. Serum immunoglobulins passively transferred from COPV L1-immunized beagles to naive beagles conferred protection from experimental infection with COPV. Our results indicate the feasibility of developing a human vaccine to prevent mucosal papillomas, which can progress to malignancy.

Variants of chemically immortalized Syrian hamster embryo cells that had either retained ([supB.sup.+]) or lost ([supB.sup.-]) the ability to suppress tumorigenicity when hybridized with a fibrosarcoma cell line were subcloned. Both supB cell types are nontumorigenic; however, the [supB.sup.-] but not [supB.sup.+] cells exhibit conditional anchorage-independent growth. Alterations of actin microfilament organization were observed in [supB.sup.-] but not [supB.sup.+] cells that corresponded to a significant reduction of the actin-binding protein tropomyosin 1 (TM-1) in [supB.sup.-] cells. To examine the possibility of a direct relationship between TM-1 expression and the [supB.sup.-] phenotype, [supB.sup.+] cells were transfected with an expression vector containing the TM-1 cDNA in an antisense orientation. The antisense-induced reduction of TM-1 levels in [supB.sup.+] clones caused a microfilament reorganization and conferred anchorage-independent growth potential that were indistinguishable from those characteristic of [supB.sup.-] cells. These data provide direct evidence that TM-1 regulates both microfilament organization and anchorage-independent growth and suggest that microfilament alterations are sufficient for anchorage-independent growth.

The signaling pathway for regulation of retinoblastoma (Rb) gene product requires the lipid mediator ceramide and this suppressor pathway plays an important role in oncogenesis. Dephosphorylation of Rb occurs in the presence of exogenous C6-ceramide, depending on the dosage and duration of ceramide administration. Rb functions as a downstream ceramic-pathway target during growth suppression.

Overexpression of E2F1 transcription factor, using a recombinant adenovirus containing the human E2F1 gene, in mink lung epithelial cells exhibiting transforming growth factor-beta (TGF-beta)-mediated growth arrest helps assess the role of E2F1 transcription factor. E2F1 overexpression prevents growth inhibition mediated by TGF-beta. Thus, E2F activation is a downstream target for the TGF-beta-mediated cyclin-dependent kinases.

Amiloride-sensitive Na+/H+ antiport, potassium conductance and glutamate efflux are stimulated by subjecting primary rat and human astrocytes to heat-activated human immunodeficiency virus type 1 (HIV-1) or to eukaryotically exposed HIV-1 and HIV-2 envelope glycoproteins (gp-120). Pathogenesis of acquired immunodeficiency syndrome dementia complex involves the astrocyte.

The varying potencies of transforming growth factor (TGF) beta2 and TGF-beta1 on the fetal bovine heart endothelial cell development are due to aa 45 and 47 amino acids. TGF-beta1 and TGF-beta2 are the functional domains of TGF-beta, the former being sequestered by alpha2-macroglobulin. The activity of TGF-beta1 with aa 40-82 can be specified by amino acids external to the aa 40-82 region.

An isoform of the estrogen receptor messenger RNA, ER-mRNA, was noticed in RNA from the brain of lizards and rats, and the gene-specific primer for the ER employed to reverse transcribe Poly(A)+ RNA from brain and uteri showed that the complementary DNA was amplified in a polymerase chain reaction after which there was cloning and sequencing of the amplified products. The triangle 4 isoform, the only one observed in normal tissue, was in abundance in RNA from brain tissue, while uterine RNA had only small traces of it. This abundance was due to tissue-specific alternative splicing. The putative triangle 4 protein may be a ligand-independent transcription factor that acts on the same DNA response elements as the conventional ER.

Metaseiulus occidentalis was transformed using a newly developed microinjection technique which utilizes the microinjection of early preblastoderm eggs within gravid females. Maternal injection was administered through the cuticle of gravid females into the egg or in the tissue immediately surrounding the egg. Transformation occurred in the sixth generation and the technique was found to show high levels of survival and transformation.

A study was done on the structure-function relationship of the yeast fatty acid synthase using negative stain, cryo-electron microscopy and image analysis studies. Results show that the yeast fatty acid molecule is a prolate ellipsoid with a high-density band of protein bisecting its major axis. It has a Y-shaped central core connected to a hexagonal ring having three each alternating egg- and kidney shaped features with low-density-protein protrusions.

Amino acids responsible for the enhanced activity of transforming growth factor beta1 (TGF) and TGF beta2 on the growth and migration of endothelial cells were mapped using a chimeric TGF-beta molecule. Results show that the sequence between amino acids 40 and 82 of the mature TGF-beta molecule specifies TGF-beta1 potency on both the growth and migration of endothelial cells. The use of chimeric molecules is seen as a practical approach to investigating the structure and function relationships in closely related proteins.

Permanent human aortic and myometrical smooth muscle cell (SMC) lines were established by infecting the primary cell cultures with the E6 and E7 open reading frames of type 16 human papilloma virus using a defective retrovirus vector. The resulting cell lines retained the ability to express alpha-actin and aquired characteristics comparable to in vivo benign SMC proliferation. These lines maybe used in the study of development of atherosclerosis and leiomyomas.

Cell-cell adhesions are often subjected to mechanical strains of different rates and magnitudes in normal tissue function. However, the rate-dependent mechanical behavior of individual cell-cell adhesions has not been fully characterized due to the lack of proper experimental techniques and therefore remains elusive. This is particularly true under large strain conditions, which may potentially lead to cell-cell adhesion dissociation and ultimately tissue fracture. In this study, we designed and fabricated a single-cell adhesion micro tensile tester (SCAµTT) using twophoton polymerization and performed displacement-controlled tensile tests of individual pairs of adherent epithelial cells with a mature cell-cell adhesion. Straining the cytoskeleton-cell adhesion complex system reveals a passive shear-thinning viscoelastic behavior and a rate-dependent active stress-relaxation mechanism mediated by cytoskeleton growth. Under low strain rates, stress relaxation mediated by the cytoskeleton can effectively relax junctional stress buildup and prevent adhesion bond rupture. Cadherin bond dissociation also exhibits rate-dependent strengthening, in which increased strain rate results in elevated stress levels at which cadherin bonds fail. This bond dissociation becomes a synchronized catastrophic event that leads to junction fracture at high strain rates. Even at high strain rates, a single cell-cell junction displays a remarkable tensile strength to sustain a strain as much as 200% before complete junction rupture. Collectively, the platform and the biophysical understandings in this study are expected to build a foundation for the mechanistic investigation of the adaptive viscoelasticity of the cell-cell junction. [ABSTRACT FROM AUTHOR]

New Guinea singing dogs (NGSD) are identifiable by their namesake vocalizations, which are unlike any other canid population. Their novel behaviors and potential singular origin during dog domestication make them an attractive, but elusive, subject for evolutionary and conservation study. Although once plentiful on the island of New Guinea (NG), they were presumed to currently exist only in captivity. This conclusion was based on the lack of sightings in the lowlands of the island and the concurrent expansion of European- and Asian-derived dogs. We have analyzed the first nuclear genomes from a canid population discovered during a recent expedition to the highlands of NG. The extreme altitude (>4,000 m) of the highland wild dogs’ (HWD) observed range and confirmed vocalizations indicate their potential to be a wild NGSD population. Comparison of single-nucleotide polymorphism genotypes shows strong similarity between HWD and the homogeneous captive NGSD, with the HWD showing significantly higher genetic diversity. Admixture analyses and estimation of shared haplotypes with phylogenetically diverse populations also indicates the HWD is a novel population within the distinct evolutionary lineage of Oceanic canids. Taken together, these data indicate the HWD possesses a distinct potential to aid in the conservation of NGSD both in the wild and under human care. [ABSTRACT FROM AUTHOR]

A dominant male-determining locus (M-locus) establishes the male sex (M/m) in the yellow fever mosquito, Aedes aegypti. Nix, a gene in the M-locus, was shown to be a male-determining factor (M factor) as somatic knockout of Nix led to feminized males (M/m) while transient expression of Nix resulted in partially masculinized females (m/m), with male reproductive organs but retained female antennae. It was not clear whether any of the other 29 genes in the 1.3-Mb M-locus are also needed for complete sexconversion. Here, we report the generation of multiple transgenic lines that express Nix under the control of its own promoter. Genetic and molecular analyses of these lines provided insights unattainable from previous transient experiments. We show that the Nix transgene alone, in the absence of the M-locus, was sufficient to convert females into males with all male-specific sexually dimorphic features and male-like gene expression. The converted m/m males are flightless, unable to perform the nuptial flight required for mating. However, they were able to father sex-converted progeny when presented with cold-anesthetized wild-type females. We show that myo-sex, a myosin heavy-chain gene also in the M-locus, was required for male flight as knockout of myo-sex rendered wild-type males flightless. We also show that Nix-mediated female-to-male conversion was 100% penetrant and stable over many generations. Therefore, Nix has great potential for developing mosquito control strategies to reduce vector populations by female-to-male sex conversion, or to aid in a sterile insect technique that requires releasing only non-biting males. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) molybdenum disulfide (MoS2) nanomaterials are an emerging class of biomaterials that are photoresponsive at near-infrared wavelengths (NIR). Here, we demonstrate the ability of 2D MoS2 to modulate cellular functions of human stem cells through photothermal mechanisms. The interaction of MoS2 and NIR stimulation of MoS2 with human stem cells is investigated using whole-transcriptome sequencing (RNA-seq). Global gene expression profile of stem cells reveals significant influence of MoS2 and NIR stimulation of MoS2 on integrins, cellular migration, and wound healing. The combination of MoS2 and NIR light may provide new approaches to regulate and direct these cellular functions for the purposes of regenerative medicine as well as cancer therapy. [ABSTRACT FROM AUTHOR]

The development of complex cognitive functions during human evolution coincides with pronounced encephalization and expansion of white matter, the brain’s infrastructure for region-toregion communication. We investigated adaptations of the human macroscale brain network by comparing human brain wiring with that of the chimpanzee, one of our closest living primate relatives. White matter connectivity networks were reconstructed using diffusion-weighted MRI in humans (n = 57) and chimpanzees (n = 20) and then analyzed using network neuroscience tools. We demonstrate higher network centrality of connections linking multimodal association areas in humans compared with chimpanzees, together with a more pronounced modular topology of the human connectome. Furthermore, connections observed in humans but not in chimpanzees particularly link multimodal areas of the temporal, lateral parietal, and inferior frontal cortices, including tracts important for language processing. Network analysis demonstrates a particularly high contribution of these connections to global network integration in the human brain. Taken together, our comparative connectome findings suggest an evolutionary shift in the human brain toward investment of neural resources in multimodal connectivity facilitating neural integration, combined with an increase in language-related connectivity supporting functional specialization. [ABSTRACT FROM AUTHOR]