1,017 research outputs found
Reaction times and reflection in social dilemmas:Extreme responses are fast, but not intuitive
Large-scale pharmacogenomic study of sulfonylureas and the QT, JT and QRS intervals: CHARGE Pharmacogenomics Working Group
Sulfonylureas, a commonly used class of medication used to treat type 2 diabetes, have been associated with an increased risk of cardiovascular disease. Their effects on QT interval duration and related electrocardiographic phenotypes are potential mechanisms for this adverse effect. In 11 ethnically diverse cohorts that included 71 857 European, African-American and Hispanic/Latino ancestry individuals with repeated measures of medication use and electrocardiogram (ECG) measurements, we conducted a pharmacogenomic genome-wide association study of sulfonylurea use and three ECG phenotypes: QT, JT and QRS intervals. In ancestry-specific meta-analyses, eight novel pharmacogenomic loci met the threshold for genome-wide significance (P<5 × 10−8), and a pharmacokinetic variant in CYP2C9 (rs1057910) that has been associated with sulfonylurea-related treatment effects and other adverse drug reactions in previous studies was replicated. Additional research is needed to replicate the novel findings and to understand their biological basis
Search for direct production of charginos and neutralinos in events with three leptons and missing transverse momentum in √s = 7 TeV pp collisions with the ATLAS detector
A search for the direct production of charginos and neutralinos in final states with three electrons or muons and missing transverse momentum is presented. The analysis is based on 4.7 fb−1 of proton–proton collision data delivered by the Large Hadron Collider and recorded with the ATLAS detector. Observations are consistent with Standard Model expectations in three signal regions that are either depleted or enriched in Z-boson decays. Upper limits at 95% confidence level are set in R-parity conserving phenomenological minimal supersymmetric models and in simplified models, significantly extending previous results
Naked Singularity Formation In f(R) Gravity
We study the gravitational collapse of a star with barotropic equation of
state in the context of theories of gravity.
Utilizing the metric formalism, we rewrite the field equations as those of
Brans-Dicke theory with vanishing coupling parameter. By choosing the
functionality of Ricci scalar as , we
show that for an appropriate initial value of the energy density, if
and satisfy certain conditions, the resulting singularity would be naked,
violating the cosmic censorship conjecture. These conditions are the ratio of
the mass function to the area radius of the collapsing ball, negativity of the
effective pressure, and the time behavior of the Kretschmann scalar. Also, as
long as parameter obeys certain conditions, the satisfaction of the
weak energy condition is guaranteed by the collapsing configuration.Comment: 15 pages, 4 figures, to appear in GR
Low-mass pre--main-sequence stars in the Magellanic Clouds
[Abridged] The stellar Initial Mass Function (IMF) suggests that sub-solar
stars form in very large numbers. Most attractive places for catching low-mass
star formation in the act are young stellar clusters and associations, still
(half-)embedded in star-forming regions. The low-mass stars in such regions are
still in their pre--main-sequence (PMS) evolutionary phase. The peculiar nature
of these objects and the contamination of their samples by the evolved
populations of the Galactic disk impose demanding observational techniques for
the detection of complete numbers of PMS stars in the Milky Way. The Magellanic
Clouds, the companion galaxies to our own, demonstrate an exceptional star
formation activity. The low extinction and stellar field contamination in
star-forming regions of these galaxies imply a more efficient detection of
low-mass PMS stars than in the Milky Way, but their distance from us make the
application of special detection techniques unfeasible. Nonetheless, imaging
with the Hubble Space Telescope yield the discovery of solar and sub-solar PMS
stars in the Magellanic Clouds from photometry alone. Unprecedented numbers of
such objects are identified as the low-mass stellar content of their
star-forming regions, changing completely our picture of young stellar systems
outside the Milky Way, and extending the extragalactic stellar IMF below the
persisting threshold of a few solar masses. This review presents the recent
developments in the investigation of PMS stars in the Magellanic Clouds, with
special focus on the limitations by single-epoch photometry that can only be
circumvented by the detailed study of the observable behavior of these stars in
the color-magnitude diagram. The achieved characterization of the low-mass PMS
stars in the Magellanic Clouds allowed thus a more comprehensive understanding
of the star formation process in our neighboring galaxies.Comment: Review paper, 26 pages (in LaTeX style for Springer journals), 4
figures. Accepted for publication in Space Science Review
Reassured evaluation of the Bioline HCV point-of-care testing for diagnosing hepatitis C virus infection in primary healthcare settings of Ghana : a study protocol
INTRODUCTION: Hepatitis C virus (HCV) infection is a silent epidemic that needs a comprehensive and contextualised approach to manage. Access to readily available, affordable and acceptable HCV point-of-care (POC) in vitro diagnostics (IVDs) is equally required to meet the global HCV goals. However, most guidelines for evaluating these IVDs such as the WHO prequalification process and country-specific standards disproportionately focus on diagnostic performance. The real-time connectivity, ease of specimen collection, affordability, sensitivity, specificity, user-friendliness, rapidity and robustness, equipment-free or simplicity and deliverability to end-users (REASSURED) criteria provide a holistic and user-oriented evaluation of the IVDs in the populations they are meant to be used. Therefore, as part of a multinational study in sub-Saharan Africa, we will conduct an evaluation of the Bioline HCV POC test for diagnosing HCV infection in primary healthcare settings of Ghana using the REASSURED criteria.
METHODS AND ANALYSIS: This field evaluation will be conducted in three phases. The first phase will use a cross-sectional field evaluation study design to evaluate the diagnostic performance of the Bioline HCV POC test. The second phase will use mixed methods to ascertain operational characteristics and users’ perceptions. In the third phase, a cross-sectional survey will be used to estimate the costs of accessing HCV diagnostics services using three proposed HCV testing models to inform the affordability of the testing pathways and linkage to care in the primary healthcare clinics. This phase will run concurrently with the second phase of the study. Thematic content analysis and quantitative data analysis will be performed using ATLAS.ti V.23.0.6 and StataCorp LLC’s Stata statistical software V.16.0, respectively.
ETHICS AND DISSEMINATION: The study protocol has been reviewed and fully approved by the Faculty of Health Sciences Research Ethics Committee, University of Pretoria (281/2023) and the Ghana Health Service Ethics Review Committee (GHS-ERC013/08/23). This diagnostic trial has also been registered in the Pan African Clinical Trial Registry (PACTR202410837698664). The findings of the study will be presented in relevant peer-reviewed journals, at local and international conferences, and to all stakeholders involved.Abbott Rapid Diagnostics.https://bmjopen.bmj.com/School of Health Systems and Public Health (SHSPH)SDG-03:Good heatlh and well-beingSDG-10:Reduces inequalitie
Drug-gene interactions of antihypertensive medications and risk of incident cardiovascular disease: A pharmacogenomics study from the CHARGE consortium
Background Hypertension is a major risk factor for a spectrum of cardiovascular diseases (CVD), including myocardial infarction, sudden death, and stroke. In the US, over 65 million people have high blood pressure and a large proportion of these individuals are prescribed antihypertensive medications. Although large long-term clinical trials conducted in the last several decades have identified a number of effective antihypertensive treatments that reduce the risk of future clinical complications, responses to therapy and protection from cardiovascular events vary among individuals. Methods Using a genome-wide association study among 21,267 participants with pharmaceutically treated hypertension, we explored the hypothesis that genetic variants might influence or modify the effectiveness of common antihypertensive therapies on the risk ofmajor cardiovascular outcomes. The classes of drug treatments included angiotensin-converting enzyme inhibitors, beta-blockers, calcium channel blockers, and diuretics. In the setting of the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, each study performed array-based genome-wide genotyping, imputed to HapMap Phase II reference panels, and used additive genetic models in proportional hazards or logistic regressionmodels to evaluate drug-gene interactions for each of four therapeutic drug classes. We used meta-analysis to combine study-specific interaction estimates for approximately 2 million single nucleotide polymorphisms (SNPs) in a discovery analysis among 15,375 European Ancestry participants (3,527 CVD cases) with targeted follow-up in a case-only study of 1,751 European Ancestry GenHAT participants as well as among 4,141 African-Americans (1,267 CVD cases). Results Although drug-SNP interactions were biologically plausible, exposures and outcomes were well measured, and power was sufficient to detect modest interactions, we did not identify any statistically significant interactions from the four antihypertensive therapy meta-analyses (Pinteraction > 5.0×10-8). Similarly, findings were null for meta-analyses restricted to 66 SNPs with significant main effects on coronary artery disease or blood pressure from large published genom
Genome-Wide Association Study for Incident Myocardial Infarction and Coronary Heart Disease in Prospective Cohort Studies: The CHARGE Consortium
Background Data are limited on genome-wide association studies (GWAS) for incident coronary heart disease (CHD). Moreover, it is not known whether genetic variants identified to date also associate with risk of CHD in a prospective setting. Methods We performed a two-stageGWAS analysis of incident myocardial infarction (MI) and CHD in a total of 64,297 individuals (including 3898MI cases, 5465 CHD cases). SNPs that passed an arbitrary threshold of 5×10-6 in Stage I were taken to Stage II for further discovery. Furthermore, in an analysis of prognosis, we studied whether known SNPs from former GWAS were associated with totalmortality in individuals who experienced MI during follow-up. Results In Stage I 15 loci passed the threshold of 5×10-6; 8 loci for MI and 8 loci for CHD, for which one locus overlapped and none were reported in previous GWAS meta-analyses. We took 60 SNPs representing these 15 loci to Stage II of discovery. Four SNPs near QKI showed nominally significant association with MI (p-value<8.8×10-3) and three exceeded the genome-wide significance threshold when Stage I and Stage II results were combined (top SNP rs6941513: p = 6.2×10-9). Despite excellent power, the 9p21 locus SNP (rs1333049) was only modestly associated with MI (HR = 1.09, p-value = 0.02) and marginally with CHD (HR = 1.06, p-value = 0.08). Among an inception cohort of those who experienced MI during follow-up, the risk allele of rs1333049 was associated with a decreased risk of subsequent mortality (HR = 0.90, p-value = 3.2×10-3). Conclusions QKI represents a novel locus that may serve as a predictor of incident CHD in prospective studies. The association of the 9p21 locus both with increased risk of first myocardial infarction and longer survival after MI highlights the importance of study design in investigating genetic determinants of complex disorders
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Genome-Wide Meta-Analyses of Smoking Behaviors in African Americans
The identification and exploration of genetic loci that influence smoking behaviors have been conducted primarily in populations of the European ancestry. Here we report results of the first genome-wide association study meta-analysis of smoking behavior in African Americans in the Study of Tobacco in Minority Populations Genetics Consortium (n=32 389). We identified one non-coding single-nucleotide polymorphism (SNP; rs2036527[A]) on chromosome 15q25.1 associated with smoking quantity (cigarettes per day), which exceeded genome-wide significance (=0.040, s.e.=0.007, P=1.84 × 10). This variant is present in the 5′-distal enhancer region of the CHRNA5 gene and defines the primary index signal reported in studies of the European ancestry. No other SNP reached genome-wide significance for smoking initiation (SI, ever vs never smoking), age of SI, or smoking cessation (SC, former vs current smoking). Informative associations that approached genome-wide significance included three modestly correlated variants, at 15q25.1 within PSMA4, CHRNA5 and CHRNA3 for smoking quantity, which are associated with a second signal previously reported in studies in European ancestry populations, and a signal represented by three SNPs in the SPOCK2 gene on chr10q22.1. The association at 15q25.1 confirms this region as an important susceptibility locus for smoking quantity in men and women of African ancestry. Larger studies will be needed to validate the suggestive loci that did not reach genome-wide significance and further elucidate the contribution of genetic variation to disparities in cigarette consumption, SC and smoking-attributable disease between African Americans and European Americans
Water vapor measurements by Raman lidar during the ARM 1997 Water Vapor Intensive Observation Period
Water vapor is the most important greenhouse gas in the atmosphere, as it is the most active infrared absorber and emitter of radiation, and it also plays an important role in energy transport and cloud formation. Accurate, high resolution measurements of this variable are critical in order to improve the understanding of these processes and thus their ability to model them. Because of the importance of water vapor, the Department of Energy`s Atmospheric Radiation Measurement (ARM) program initiated a series of three intensive operating periods (IOPs) at its Cloud and Radiation Testbed (CART) site in northern Oklahoma. The goal of these IOPs is to improve and validate the state-of-the-art capabilities in measuring water vapor. To date, two of the planned three IOPs have occurred: the first was in September of 1996, with an emphasis on the lowest kilometer, while the second was conducted from September--October 1997 with a focus on both the upper troposphere and lowest kilometer. The ARM CART site is the home of several different water vapor measurement systems. These systems include a Raman lidar, a microwave radiometer, a radiosonde launch site, and an instrumented tower. During these IOPs, additional instrumentation was brought to the site to augment the normal measurements in the attempt to characterize the CART instruments and to address the need to improve water vapor measurement capabilities. Some of the instruments brought to the CART site include a scanning Raman lidar system from NASA/GSFC, additional microwave radiometers from NOAA/ETL, a chilled mirror that was flown on a tethersonde and kite system, and dewpoint hygrometer instruments flow on the North Dakota Citation. This paper will focus on the Raman lidar intercomparisons from the second IOP
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