11 research outputs found
Characterization of Genome-Wide Association-Identified Variants for Atrial Fibrillation in African Americans
Despite a greater burden of risk factors, atrial fibrillation (AF) is less common among African Americans than European-descent populations. Genome-wide association studies (GWAS) for AF in European-descent populations have identified three predominant genomic regions associated with increased risk (1q21, 4q25, and 16q22). The contribution of these loci to AF risk in African American is unknown.We studied 73 African Americans with AF from the Vanderbilt-Meharry AF registry and 71 African American controls, with no history of AF including after cardiac surgery. Tests of association were performed for 148 SNPs across the three regions associated with AF, and 22 SNPs were significantly associated with AF (P<0.05). The SNPs with the strongest associations in African Americans were both different from the index SNPs identified in European-descent populations and independent from the index European-descent population SNPs (r(2)<0.40 in HapMap CEU): 1q21 rs4845396 (odds ratio [OR] 0.30, 95% confidence interval [CI] 0.13-0.67, P = 0.003), 4q25 rs4631108 (OR 3.43, 95% CI 1.59-7.42, P = 0.002), and 16q22 rs16971547 (OR 8.1, 95% CI 1.46-45.4, P = 0.016). Estimates of European ancestry were similar among cases (23.6%) and controls (23.8%). Accordingly, the probability of having two copies of the European derived chromosomes at each region did not differ between cases and controls.Variable European admixture at known AF loci does not explain decreased AF susceptibility in African Americans. These data support the role of 1q21, 4q25, and 16q22 variants in AF risk for African Americans, although the index SNPs differ from those identified in European-descent populations
Abstracts of presentations on plant protection issues at the fifth international Mango Symposium Abstracts of presentations on plant protection issues at the Xth international congress of Virology: September 1-6, 1996 Dan Panorama Hotel, Tel Aviv, Israel August 11-16, 1996 Binyanei haoma, Jerusalem, Israel
Bioclimates, aridity and végétation stages mapping in Morocco
Lâobjectif de cet article est lâanalyse comparative de lâextension spatiale et de la localisation gĂ©ographique de lâariditĂ© et des Ă©tages bioclimatiques du Maroc et de leurs limites en utilisant diffĂ©rents indices utilisĂ©s en Afrique du Nord et ailleurs en MĂ©diterranĂ©e. Lâanalyse a Ă©tĂ© orientĂ©e vers lâutilisation des donnĂ©es issues de la base donnĂ©es WorldClim, la spatialisation moyennant les techniques SIG et lâĂ©tude de la rĂ©partition des diffĂ©rentes espĂšces vĂ©gĂ©tales. Ainsi, les Ă©tages bioclimatiques ont Ă©tĂ© caractĂ©risĂ©s moyennant une approche spatiale en utilisant le diagramme pluviothermique dâEmberger (Sauvage, 1963). Les rĂ©sultats obtenus montrent que les zones hyperarides au Maroc reprĂ©sentent 45 Ă 55% du territoire en fonction des diffĂ©rents indices dâariditĂ©. La rĂ©partition spatiale des pluies indique que 48% du territoire Marocain reçoit moins de 100mm annuellement, alors que les rĂ©gions oĂč il pleut plus de 600mm ne dĂ©passent pas les 6%. Les zones arides, semi-arides et subhumides potentiellement concernĂ©es par la dĂ©sertification sont de lâordre de 42%. La comparaison des diffĂ©rents indices utilisĂ©s montre que lâindice dâariditĂ© de De Martonne, le plus facile Ă calculer, reste satisfaisant pour les Ă©tudes Ă caractĂšre rĂ©gional. La dĂ©rivation de la carte des Ă©tages bioclimatiques, en se basant sur le diagramme dâEmberger, (Q2 et Tmin) montre lâexistence au Maroc de 5 grands types de climats allant de humide jusquâau peraride. LâĂ©tage perhumide nâexistant que sous forme insignifiante au niveau des crĂȘtes de la chaine du Rif (<5KmÂČ). Les variantes thermiques allant du « TempĂ©rĂ© » à « TrĂšs chaud » y reprĂ©sentent plus que 70%
Investigations of the availability and survival of submersed aquatic vegetation propagules in the tidal Potomac River
The establishment of submersed aquatic vegetation (SAV) at unvegetated sites in the freshwater tidal Potomac River was limited primarily by factors other than propagule availability. For two years, traps were used to quantify the amount of plant material reaching three unvegetated sites over the growing season. The calculated flux values provided a gross estimate of the flux of propagules that could potentially survive if other site factors were suitable. The mean flux ofHydrilla verticillata and all other species (?0.01 gdw m?2 d?1) appeared sufficient to favor the establishment of vegetation, particularly considering the high viability (70â100%) of whole plants and fragments under controlled conditions. However, median water clarity values (i.e., for light attenuation, Secchi depth, total suspended solids, and chlorophylla) were below SAV restoration goals at all unvegetated sites. Additionally, sediments from unvegetated sites showed a potential for nitrogen limitation of the growth ofH. verticillata. Our findings support the hypothesis that in the tidal Potomac River, water clarity and nutrient (especially nitrogen) levels in sediment are key to plant community establishment
Habitat requirements for submerged aquatic vegetation in Chesapeake Bay: Water quality, light regime, and physical-chemical factors
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Coronary Artery Calcification (CAC) and PostâTrial Cardiovascular Events and Mortality Within the Women's Health Initiative (WHI) EstrogenâAlone Trial
Background: Among women aged 50 to 59 years at baseline in the Women's Health Initiative (WHI) EstrogenâAlone (EâAlone) trial, randomization to conjugated equine estrogenâalone versus placebo was associated with lower risk of myocardial infarction and mortality, and, in an ancillary study, the WHIâCACS (WHI Coronary Artery Calcification Study) with lower CAC, measured by cardiac computed tomography â8.7 years after baseline randomization. We hypothesized that higher CAC would be related to postâtrial coronary heart disease (CHD), cardiovascular disease (CVD), and total mortality, independent of baseline randomization or risk factors. Methods and Results: WHIâCACS participants (n=1020) were followed â8 years from computed tomography scan in 2005 (mean age=64.4) through 2013 for incident CHD (myocardial infarction and fatal CHD, n=17), CVD (n=69), and total mortality (n=55). Incident CHD and CVD analyses excluded women with CVD before scan (n=89). Women with CAC=0 (n=54%) had very low ageâadjusted rates/1000 personâyears of CHD (0.91), CVD (5.56), and mortality (3.45). In comparison, rates were â2âfold higher for women with any CAC (>0). Associations were not modified by baseline randomization to conjugated equine estrogenâalone versus placebo. Adjusted for baseline randomization and risk factors, the hazard ratio (95% confidence interval) for CAC >100 (19%) was 4.06 (2.11, 7.80) for CVD and 2.70 (1.26, 5.79) for mortality. Conclusions: Among a subset of postmenopausal women aged 50 to 59 years at baseline in the WHI EâAlone Trial, CAC at mean age of 64 years was strongly related to incident CHD, CVD, and to total mortality over â8 years, independent of baseline randomization to conjugated equine estrogenâalone versus placebo or CVD risk factors. Clinical Trial Registration URL: https://www.clinicaltrials.gov. Unique identifier: NCT00000611
BioTIME:a database of biodiversity time series for the Anthropocene
Abstract
Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a communityâled openâsource database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.
Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of 2 years, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology and contextual information about each record.
Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 kmÂČ (158 cmÂČ) to 100 kmÂČ (1,000,000,000,000 cmÂČ).
Time period and grain: BioTIME records span from 1874 to 2016. The minimal temporal grain across all datasets in BioTIME is a year.
Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton and terrestrial invertebrates to small and large vertebrates.
Software format: .csv and .SQL
BioTIME:a database of biodiversity time series for the Anthropocene
Motivation: The BioTIME database contains raw data on species identities and abundances in ecological assemblages through time. These data enable users to calculate temporal trends in biodiversity within and amongst assemblages using a broad range of metrics. BioTIME is being developed as a community led open-source database of biodiversity time series. Our goal is to accelerate and facilitate quantitative analysis of temporal patterns of biodiversity in the Anthropocene.Main types of variables included: The database contains 8,777,413 species abundance records, from assemblages consistently sampled for a minimum of two, which need not necessarily be consecutive. In addition, the database contains metadata relating to sampling methodology andcontextual information about each record.Spatial location and grain: BioTIME is a global database of 547,161 unique sampling locations spanning the marine, freshwater and terrestrial realms. Grain size varies across datasets from 0.0000000158 km2 (158 cm2) to 100 km2 (1 000 000 000 000 cm2).Time period and grain: BioTIME records span from 1874 to 2016. The minimum temporal grain across all datasets in BioTIME is year.Major taxa and level of measurement: BioTIME includes data from 44,440 species across the plant and animal kingdoms, ranging from plants, plankton, and terrestrial invertebrates to small and large vertebrates.Software format: .csv and .SQ
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Are rare species useful species? Obstacles to the conservation of tree diversity in the dry forest zone agro-ecosystems of Mesoamerica
Aim To test the potential to conserve rare dry forest tree and shrub species circa situm.Location Oaxaca, Mexico and Southern Honduras.Methods Local uses (timber, posts and firewood) of species were determined principally through semistructured interviews with 20 rural householders in each of four communities in Honduras and four in Oaxaca. Tree and shrub diversity inventories were carried out in a total of 227 forest patches and parcels of farmland in those eight communities. Speciesâ conservation priorities were determined using the star system of Hawthorne (1996) and IUCN listings.Results Despite a large number of useful species, remarkably few were also conservation priorities. Useful species were found to be substitutable as is illustrated by Bombacopsis quinata, Cordia alliodora, Guaiacum sanctum and G. coulteri.Conclusions In these areas, circa situm conservation is inhibited by the lack of species that are both rare and useful. Usefulness must be interpreted as a function of substitutability. Natural regeneration provides an abundance of diversity, farmers are unlikely to invest in the management of a species when suitable substitutes are freely available. The key to conserving rare species may be in maintaining or enhancing the value of the landscape elements in which they are found