37 research outputs found
Genome-wide association study in an admixed case series reveals IL12A as a new candidate in Behçet Disease
Introduction: The etiology of Behçet's disease (BD) is unknown, but widely considered an excessive T-cell mediated inflammatory response in a genetically susceptible host. Recent genomewide association studies (GWAS) have shown limited number of novel loci-associations. The rarity and unequal distribution of the disease prevalence amongst different ethnic backgrounds have hampered the use of GWAS in cohorts of mixed ethnicity and sufficient sample size. However, novel statistical approaches have now enabled GWAS in admixed cohorts. Methods: We ran a GWAS on 336 BD cases and 5,843 controls. The cases consisted of Western Europeans, Middle Eastern and Turkish individuals. Participants from the Generation R study, a multiethnic birth cohort in Rotterdam, The Netherlands were used as controls. All samples were genotyped and data was combined. Linear regression models were corrected for population stratification using Genomic Principal Components and Linear Mixed Modelling. Meta-analysis was performed on selected results previously published. Results: We identified SNPs associated at genome-wide significant level mapping to the 6p21.33 (HLA) region. In addition to this known signal two potential novel associations on chromosomes 6 and 18 were identified, yet with low minor allele frequencies. Extended metaanalysis reveal a GWS association with the IL12A variant rs17810546 on chromosome 3. Discussion: We demonstrate that new statistical techniques enable GWAS analyses in a limited sized cohort of mixed ethnicity. After implementation, we confirmed the central role of the HLA region in the disease and identified new regions of interest. Moreover, we validated the association of a variant in the IL2A gene by meta-analysis with previous work. These findings enhance our
Diverse aging rates in ectothermic tetrapods provide insights for the evolution of aging and longevity
Comparative studies of mortality in the wild are necessary to understand the evolution of aging; yet, ectothermic tetrapods are underrepresented in this comparative landscape, despite their suitability for testing evolutionary hypotheses. We present a study of aging rates and longevity across wild tetrapod ectotherms, using data from 107 populations (77 species) of nonavian reptiles and amphibians. We test hypotheses of how thermoregulatory mode, environmental temperature, protective phenotypes, and pace of life history contribute to demographic aging. Controlling for phylogeny and body size, ectotherms display a higher diversity of aging rates compared with endotherms and include phylogenetically widespread evidence of negligible aging. Protective phenotypes and life-history strategies further explain macroevolutionary patterns of aging. Analyzing ectothermic tetrapods in a comparative context enhances our understanding of the evolution of aging.Animal science
IDCS J1426.5+3508: Weak Lensing Analysis of a Massive Galaxy Cluster at z = 1.75
We present a weak lensing study of the galaxy cluster IDCS J1426.5+3508 at z = 1.75, which is the highest-redshift strong lensing cluster known and the most distant cluster for which a weak lensing analysis has been undertaken. Using F160W, F814W, and F606W observations with the Hubble Space Telescope, we detect tangential shear at 2Ï significance. Fitting a NavarroâFrenkâWhite mass profile to the shear with a theoretical median mass-concentration relation, we derive a mass Mâ. This mass is consistent with previous mass estimates from the SunyaevâZel'dovich (SZ) effect, X-ray, and strong lensing. The cluster lies on the local SZâweak lensing mass scaling relation observed at low redshift, indicative of minimal evolution in this relation
1963 summer study report.
"AEC Contract AT(04-3)-476.""AEC Contract AT(04-3)-400.""SLAC Report No. 25.""Summer 1963."Cover title.Includes bibliographical references.Part 2. Authors include: L. Hand and R. WIson.Part 1. Authors include: K. Berkelman, G.R. Bishop, C. de Vries, G. Feldman, D.B. Isabelle, D.B. Lichtenberg, J. Mathews, J. Pine, R. Wilson.Mode of access: Internet
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1989 neutron and gamma personnel dosimetry intercomparison study using RADCAL (Radiation Calibration Laboratory) sources
The fourteenth Personnel Dosimetry Intercomparison Study (i.e., PDIS 14) was conducted during May 1-5, 1989. A total of 48 organizations (33 from the US and 15 from abroad) participated in PDIS 14. Participants submitted by mail a total of 1,302 neutron and gamma dosimeters for this mixed field study. The type of neutron dosimeter and the percentage of participants submitting that type are as follows: TLD-albedo (40%), direct interaction TLD (22%), track (20%), film (7%), combination (7%), and bubble detectors (4%). The type of gamma dosimeter and the percentage of participants submitting that type are as follows: TLD (84%) and film (16%). Radiation sources used in the six PDIS 14 exposures included {sup 252}Cf moderated by 15-cm D{sub 2}O, {sup 252}Cf moderated by 15-cm polyethylene (gamma-enhanced with {sup 137}Cs), and {sup 238}PuBe. Neutron dose equivalents ranged from 0.44--2.63 mSv and gamma doses ranged from 0. 01-1.85 mSv. One {sup 252}Cf(D{sub 2}O) exposure was performed at a 60{degree} angle of incidence (most performance tests are at perpendicular incidence). The average neutron dosimeter response for this exposure was 70% of that at normal incidence. The average gamma dosimeter response was 96% of that at normal incidence. A total of 70% of individual reported neutron dosimeter measurements were within {plus minus}50% of reference values. If the 0.01 mSv data are omitted, approximately 90% of the individual reported gamma measurements were within {plus minus}50% of reference values. 33 refs., 9 figs., 27 tabs
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Methods of analysis for complex organic aerosol mixtures from urban emission sources of particulate carbon
Extractable organic compounds having between 6 to 40 carbon atoms comprise an important mass fraction of the fine particulate matter samples from major urban emission sources. Depending on the emission source type, this solvent-soluble fraction accounts for <20% to 100% of the total organic aerosol mass, as measured by quantitative high-resolution has chromatography (HRGC) with flame ionization detection. In addition to total extract quantitation, HRGC can be applied to further analyses of the mass distributions of elutable organics present in the complex aerosol extract mixtures, thus generating profiles that serve as fingerprints'' for the sources of interest. This HRGC analytical method is applied to emission source samples that contain between 7 to 12,000 {mu}g/filter organic carbon. It is shown to be a sensitive technique for analysis of carbonaceous aerosol extract mixtures having diverse mass loadings and species distributions. This study describes the analytical chemical methods that have been applied to: the construction of chemical mass balances based on the mass of fine organic aerosol emitted for major urban sources of particulate carbon; and the generation of discrete emission source chemical profiles derived from chromatographic characteristics of the organic aerosol components. 21 refs., 1 fig., 2 tabs
Diving behaviour of Elseya albagula from a naturally flowing and hydrologically altered habitat
This study investigated the diving behaviour and performance of the bimodally respiring turtle Elseya albagula within the Burnett River, central Qld, Australia. Diving parameters were recorded using pressure-sensitive time-depth recorders for turtles residing within a free flowing versus regulated reach. Maximum submergence time recorded for El. albagula (greater than 3 hours) is among the longest recorded for a voluntarily diving vertebrate, and is attributed to the turtle's ability to respire aquatically. Median dive times logged for El. albagula within the regulated reach (6.7 min) were threefold longer than values recorded for turtles residing within a naturally flowing creek (1.9 min), with discrepancies in dive duration possibly due to the variable hydrologic flows recorded below the weir. No correlation was observed between dive duration and subsequent surfacing intervals, suggesting that dives remained aerobic throughout the study. Despite considerable differences in the magnitude and daily variation of water flow between the two locations, similar diel activity and surfacing trends were recorded for El. albagula. Turtles undertook deep resting dives (> 1.5 m) during the day before moving into shallower habitats (< 1.0m) for the night, while the crepuscular hours were characterized by elevated surfacing frequencies attributed to periods of increased activity possibly associated with foraging