13,366 research outputs found

    The envirome and the connectome: exploring the structural noise in the human brain associated with socioeconomic deprivation

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    Complex cognitive functions are widely recognized to be the result of a number of brain regions working together as large-scale networks. Recently, complex network analysis has been used to characterize various structural properties of the large scale network organization of the brain. For example, the human brain has been found to have a modular architecture i.e. regions within the network form communities (modules) with more connections between regions within the community compared to regions outside it. The aim of this study was to examine the modular and overlapping modular architecture of the brain networks using complex network analysis. We also examined the association between neighborhood level deprivation and brain network structure – modularity and grey nodes. We compared network structure derived from anatomical MRI scans of 42 middle-aged neurologically healthy men from the least (LD) and the most deprived (MD) neighborhoods of Glasgow with their corresponding random networks. Cortical morphological covariance networks were constructed from the cortical thickness derived from the MRI scans of the brain. For a given modularity threshold, networks derived from the MD group showed similar number of modules compared to their corresponding random networks, while networks derived from the LD group had more modules compared to their corresponding random networks. The MD group also had fewer grey nodes – a measure of overlapping modular structure. These results suggest that apparent structural difference in brain networks may be driven by differences in cortical thicknesses between groups. This demonstrates a structural organization that is consistent with a system that is less robust and less efficient in information processing. These findings provide some evidence of the relationship between socioeconomic deprivation and brain network topology

    Multiple interfaces between a serine recombinase and an enhancer control site-specific DNA inversion.

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    Serine recombinases are often tightly controlled by elaborate, topologically-defined, nucleoprotein complexes. Hin is a member of the DNA invertase subclass of serine recombinases that are regulated by a remote recombinational enhancer element containing two binding sites for the protein Fis. Two Hin dimers bound to specific recombination sites associate with the Fis-bound enhancer by DNA looping where they are remodeled into a synaptic tetramer competent for DNA chemistry and exchange. Here we show that the flexible beta-hairpin arms of the Fis dimers contact the DNA binding domain of one subunit of each Hin dimer. These contacts sandwich the Hin dimers to promote remodeling into the tetramer. A basic region on the Hin catalytic domain then contacts enhancer DNA to complete assembly of the active Hin tetramer. Our results reveal how the enhancer generates the recombination complex that specifies DNA inversion and regulates DNA exchange by the subunit rotation mechanism. DOI:http://dx.doi.org/10.7554/eLife.01211.001

    Social, Environmental, and Racial/Ethnic Factors in Diabetes Prevalence in the U.S.

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    PURPOSE: The purpose of this study was to determine the extent to which socioeconomic status, race/ ethnicity, and disparities in neighborhood environmental factors affect diabetes prevalence among U.S. adults. METHODS: County-level data were collected from the 1000 U.S. counties with the highest diabetes incidence and the 1000 U.S. counties with the lowest diabetes incidence using the 2014 USDA Food Environmental Atlas. The dependent measure was diabetes prevalence. Independent measures were median household income, percentage of people with no car, percentage of population that was black, white, or Hispanic, and the number of fitness centers, fast food restaurants, farmer’s markets, and grocery stores. Stepwise multiple linear regression was used to assess the relationship of these independent variables to diabetes incidence. RESULTS: Of the nine independent measures evaluated, seven explained a significant amount of the variance in diabetes prevalence (Table 1). Median household income accounted for the largest proportion of variance (38%) with the non-white population percentages collectively accounting for an additional 19%. The specific indicators of commercial entities accounted for small (≤1%) but significant proportions of variance. CONCLUSION: The results of this study indicate socioeconomic and racial/ethnic factors account for the majority of variance in prevalence of diabetes in the U.S. However, not only availability but access to healthy foods and lifestyle choices also seem to play a role in the magnitude of the incidence of diabetes. There is an apparent need for local and federal programs to focus on these high-risk areas of concentrated poverty and minority populations in order to educate communities, increase social support, and improve access to factors related to developing healthy lifestyles

    Spectropolarimetry of the H-alpha line in Herbig Ae/Be stars

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    Using the HiVIS spectropolarimeter built for the Haleakala 3.7m AEOS telescope, we have obtained a large number of high precision spectropolarimetrc observations (284) of Herbig AeBe stars collected over 53 nights totaling more than 300 hours of observing. Our sample of five HAeBe stars: AB Aurigae, MWC480, MWC120, MWC158 and HD58647, all show systematic variations in the linear polarization amplitude and direction as a function of time and wavelength near the H-alpha line. In all our stars, the H-alpha line profiles show evidence of an intervening disk or outflowing wind, evidenced by strong emission with an absorptive component. The linear polarization varies by 0.2% to 1.5% with the change typically centered in the absorptive part of the line profile. These observations are inconsistent with a simple disk-scattering model or a depolarization model which produce polarization changes centered on the emmissive core. We speculate that polarized absorption via optical pumping of the intervening gas may be the cause.Comment: Accepted for publication in ApJ Letter

    ISTRAŽIVANJE MOGUĆNOSTI RASTA KOMARČI DRŽANIH U KOMERCIJALNOM RECIRKULACIJSKOM SISTEMU I TRETIRANIH NUSPROIZVODOM INDUSTRIJSKE PROIZVODNJE GOVEĐEG HORMONA RASTA

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    Gilthead sea bream, maintained in a commercial scale recirculation system, were subjected to three injections (0,5 and 10 µg -1 body weight) with a by-product from the industrial production of recombinant bovine growth hormone (rbGH). Injections were provided at experiment start and at 3 and 6 weeks. Growth performance of animals was evaluated over a period of 8 weeks (n = 171 per treatment). At trial end fish were examined for proximate composition, fillet yield and visceral indices. No differences were recorded in individual growth performance between the three treatment groups (P > 0.05). Examination of protein productive value and protein efficiency ratio indicated approximately 20% of dietary protein was incorporated into animals irrespective of treatment. However incorporation of dietary lipid decreased with increasing dose of rbGH. High dose GH decreased liver weight (P 0,05). Istraživanje vrijednosti produktivnog proteina i količine efikasnosti proteina pokazalo je da je približno 20% proteina bilo inkorporirano u životinje neovisno o tretmanu. No inkorporacija lipida bila je smanjena povećanjem doze hormona rasta (rbGH). Visoka doza hormona rasta smanjila je težinu jetre (P < 0,05) u usporedbi s kontrolom s istodobnim smanjenjem hepatosomatskog indeksa (P < 0,05). Težina i postotak fileta bili su viši u životinja tretiranih dozom od 10 µg g -1 tjelesne težine u usporedbi s niskom dozom rbGH tretiranih riba (P < 0,05)

    Strong Nebular Line Ratios in the Spectra of z~2-3 Star-forming Galaxies: First Results from KBSS-MOSFIRE

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    We present initial results of a deep near-IR spectroscopic survey covering the 15 fields of the Keck Baryonic Structure Survey (KBSS) using MOSFIRE on the Keck 1 telescope, focusing on a sample of 251 galaxies with redshifts 2.0< z < 2.6, star-formation rates 2 < SFR < 200 M_sun/yr, and stellar masses 8.6 < log(M*/M_sun) < 11.4, with high-quality spectra in both H- and K-band atmospheric windows. We show unambiguously that the locus of z~2.3 galaxies in the "BPT" nebular diagnostic diagram exhibits a disjoint, yet similarly tight, relationship between the ratios [NII]6585/Halpha and [OIII]/Hbeta as compared to local galaxies. Using photoionization models, we argue that the offset of the z~2.3 locus relative to z~ 0 is explained by a combination of harder ionizing radiation field, higher ionization parameter, and higher N/O at a given O/H than applies to most local galaxies, and that the position of a galaxy along the z~2.3 star-forming BPT locus is surprisingly insensitive to gas-phase oxygen abundance. The observed nebular emission line ratios are most easily reproduced by models in which the net ionizing radiation field resembles a blackbody with effective temperature T_eff = 50000-60000 K and N/O close to the solar value at all O/H. We critically assess the applicability of commonly-used strong line indices for estimating gas-phase metallicities, and consider the implications of the small intrinsic scatter in the empirical relationship between excitation-sensitive line indices and stellar mass (i.e., the "mass-metallicity" relation), at z~2.3.Comment: 41 pages, 25 figures, accepted for publication in the Astrophysical Journal. Version with full-resolution figures available at http://www.astro.caltech.edu/~ccs/mos_bpt_submit.pd

    Retrospective Barrier Placements for a Skunk Rabies Epizootic in NW Wyoming

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    Striped skunks (Mephitis mephitis) are the most important reservoir of rabies on the Great Plains. In August, 1988 a skunk rabies epizootic proceeded from the index case west of Cowley, WY. By 1991, epizootic had reached nearly all areas in the Shoshone River Basin (SRB), and it ended in 1993. This area and the remainder of the SRB had been previously considered rabies-free. The USDA\u27s Wildlife Services (WS) cooperated with state and local officials in a rabies monitoring and control program starting in 1990. Using information from the literature, signs, tracks, and radio-telemetry of normal and rabid skunks, WS decided to trap mainly riparian and irrigated agricultural habitats in the valley\u27s floor. Here, a mosaic of irrigation ditches (e.g., Buffalo Bill Cody\u27s circa 1908) was shown to be travel corridors for skunks. Trapped species (\u3e1,000 skunks) were sent to the Wyoming State Veterinary Laboratory for rabies testing using immuno-fluorescent of brain tissues. The study area extended from the Bighorn Canyon and Lake on the east up river to Buffalo Bill Reservoir on the west. The study area and subsequent epizootic encompassed a portion of the Shoshone River ~90 km in length and an area of ~ 85,000 ha (54 mi2). Traditional surveillance data composed \u3c10% of the sample -public referrals of suspiciously acting wildlife and road kills. We analyzed 215 rabid skunk locations and dates together with GIS hydrology and land use information. Hypothetical barriers were modeled using potential synergisms formed among restricted habitat, depopulation, and vaccine (if one had been available), combined with the natural epizootiology of this rabies strain with high virulence. Two dates for barrier locations were identified that may have halted the spreading epizootic: 1) before April 1989, when the rabies epizootic might have been limited to Polecat and Sage Creeks, and 2) June 1989, when the epizootic may have been stopped before it entered the majority of SRB including the larger population centers of Byron, Powell, and Cody

    A Review of Network and Computer Analysis of Epileptiform Discharge Free EEG to Characterize and Detect Epilepsy.

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    Objectives. There is emerging evidence that network/computer analysis of epileptiform discharge free electroencephalograms (EEGs) can be used to detect epilepsy, improve diagnosis and resource use. Such methods are automated and can be performed on shorter recordings of EEG. We assess the evidence and its strength in the area of seizure detection from network/computer analysis of epileptiform discharge free EEG. Methods. A scoping review using Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance was conducted with a literature search of Embase, Medline and PsychINFO. Predesigned inclusion/exclusion criteria were applied to selected articles. Results. The initial search found 3398 articles. After duplicate removal and screening, 591 abstracts were reviewed, 64 articles were selected and read leading to 20 articles meeting the requisite inclusion/exclusion criteria. These were 9 reports and 2 cross-sectional studies using network analysis to compare and/or classify EEG. One review of 17 reports and 10 cross-sectional studies only aimed to classify the EEGs. One cross-sectional study discussed EEG abnormalities associated with autism. Conclusions. Epileptiform discharge free EEG features derived from network/computer analysis differ significantly between people with and without epilepsy. Diagnostic algorithms report high accuracies and could be clinically useful. There is a lack of such research within the intellectual disability (ID) and/or autism populations, where epilepsy is more prevalent and there are additional diagnostic challenges

    Ground state properties of heavy alkali halides

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    We extend previous work on alkali halides by calculations for the heavy-atom species RbF, RbCl, LiBr, NaBr, KBr, RbBr, LiI, NaI, KI, and RbI. Relativistic effects are included by means of energy-consistent pseudopotentials, correlations are treated at the coupled-cluster level. A striking deficiency of the Hartree-Fock approach are lattice constants deviating by up to 7.5 % from experimental values which is reduced to a maximum error of 2.4 % by taking into account electron correlation. Besides, we provide ab-initio data for in-crystal polarizabilities and van der Waals coefficients.Comment: accepted by Phys. Rev.
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