28 research outputs found
Meta-analysis of type 2 Diabetes in African Americans Consortium
Type 2 diabetes (T2D) is more prevalent in African Americans than in Europeans. However, little is known about the genetic risk in African Americans despite the recent identification of more than 70 T2D loci primarily by genome-wide association studies (GWAS) in individuals of European ancestry. In order to investigate the genetic architecture of T2D in African Americans, the MEta-analysis of type 2 DIabetes in African Americans (MEDIA) Consortium examined 17 GWAS on T2D comprising 8,284 cases and 15,543 controls in African Americans in stage 1 analysis. Single nucleotide polymorphisms (SNPs) association analysis was conducted in each study under the additive model after adjustment for age, sex, study site, and principal components. Meta-analysis of approximately 2.6 million genotyped and imputed SNPs in all studies was conducted using an inverse variance-weighted fixed effect model. Replications were performed to follow up 21 loci in up to 6,061 cases and 5,483 controls in African Americans, and 8,130 cases and 38,987 controls of European ancestry. We identified three known loci (TCF7L2, HMGA2 and KCNQ1) and two novel loci (HLA-B and INS-IGF2) at genome-wide significance (4.15 × 10(-94)<P<5 × 10(-8), odds ratio (OR) = 1.09 to 1.36). Fine-mapping revealed that 88 of 158 previously identified T2D or glucose homeostasis loci demonstrated nominal to highly significant association (2.2 × 10(-23) < locus-wide P<0.05). These novel and previously identified loci yielded a sibling relative risk of 1.19, explaining 17.5% of the phenotypic variance of T2D on the liability scale in African Americans. Overall, this study identified two novel susceptibility loci for T2D in African Americans. A substantial number of previously reported loci are transferable to African Americans after accounting for linkage disequilibrium, enabling fine mapping of causal variants in trans-ethnic meta-analysis studies.Peer reviewe
“The Motherhood Wage Gap for Women in the United States: The Importance of College and Fertility Delay”
family pay gap, mother’s wages, fertility delay, motherhood wage gap, wage penalty, childbearing postponement, college education,
Acute administration of dopaminergic drugs has differential effects on locomotion in larval zebrafish
Altered dopaminergic signaling causes behavioral changes in mammals. In general, dopaminergic receptor agonists increase locomotor activity, while antagonists decrease locomotor activity. In order to determine if zebrafish (a model organism becoming popular in pharmacology and toxicology) respond similarly, the acute effects of drugs known to target dopaminergic receptors in mammals were assessed in zebrafish larvae. Larvae were maintained in 96-well microtiter plates (1 larva/well). Non-lethal concentrations (0.2–50 µM) of dopaminergic agonists (apomorphine, SKF-38393, and quinpirole) and antagonists (butaclamol, SCH-23390, and haloperidol) were administered at 6 days post-fertilization (dpf). An initial experiment identified the time of peak effect of each drug (20–260 minutes post-dosing, depending on the drug). Locomotor activity was then assessed for 70 minutes in alternating light and dark at the time of peak effect for each drug to delineate dose-dependent effects. All drugs altered larval locomotion in a dose-dependent manner. Both the D1- and D2-like selective agonists (SKF-38393 and quinpirole, respectively) increased activity, while the selective antagonists (SCH-23390 and haloperidol, respectively) decreased activity. Both selective antagonists also blunted the response of the larvae to changes in lighting conditions at higher doses. The nonselective drugs had biphasic effects on locomotor activity: apomorphine increased activity at the low dose and at high doses, while butaclamol increased activity at low to intermediate doses, and decreased activity at high doses. This study demonstrates that (1) larval zebrafish locomotion can be altered by dopamine receptor agonists and antagonists, (2) receptor agonists and antagonists generally have opposite effects, and (3) drugs that target dopaminergic receptors in mammals appear, in general, to elicit similar locomotor responses in zebrafish larvae
Search for the decay at the Belle experiment
This letter presents a search for the rare flavor-changing neutral current process using data taken with the Belle detector at the KEKB asymmetric energy collider. The analysis is based on the entire resonance data sample of 711 , corresponding to pairs. In our search we fully reconstruct the companion meson produced in the process from its hadronic decay modes, and look for the decay in the rest of the event. No evidence for a signal is found. We report an upper limit on the branching fraction at 90% confidence level. This is the first direct limit on
Development of predator defences in fishes
A variety of development characteristics, morphological, behavioural, and experiential, contribute to the extreme vulnerability of young fishes to predation. The influence of these characteristics is complicated by the fact that the larval period is one of substantial and rapid change. Yet survival is the ultimate goal;-it is only by reaching maturity that individual fish have the opportunity to reproduce. With such high stakes it is not surprising that predator defences are of major importance during all phases of life. Developmental constraints may limit the defensive options for young fishes. Avoidance behaviours, which reduce the likelihood of encountering a predator or of being attacked by it, are particulaly evident in the youngest stages. Here size, coloration and dispersal are used to help elude the predator's attention. As fishes grow and acquire greater morphological and behavioural sophistication, there is more scope for predator evasion when avoidance fails. Older fishes are increasingly able to respond to external stimuli and can detect and react to predators or join conspecifics in common defence (schooling). Behavioural development is not simply a consequence of growth and the concomitant physical alterations of the body; it is also mediated by experience that comes through interaction with the physical and biotic environment. Predispositions to respond to experience may be a product of evolutionary history. Although mortality rates decline markedly with development and maturity, changes in size or behaviour can render fishes vulnerable to new suites of predators. Effective predator avoidance can compromise other activities, such as foraging, and individuals may be forced to reconcile conflicting demands. Developmental niche shifts that occur, for example, when certain size classes take refuge in less profitable feeding habitats, represent one such trade-off. Niche shifts may also be mediated by the influence of the programme for morphological development on sensory or behavioural capabilities. In addition to all of these developmental consderations, natural variations in environmental conditions - such as temperature, photoperiod, predator density and variety, and presence of alternative prey - represent additional challenges to predator defences during the rite of passage from birth to reproduction.</p
Rediscovery of at Belle II
We present preliminary results on the reconstruction of the decay, where or . Using a dataset corresponding to a luminosity of 62.8\pm0.6\mbox{fb}^{-1} collected by the Belle II experiment at the SuperKEKB asymmetric energy collider, we measure a total of candidates with and with with . The quoted errors are statistical only
Measurement of the Branching Fraction in 62.8 fb of Belle II data
We report a measurement of the branching fraction of the semileptonic decay (and its charge conjugate) using 62.8 fb of (4) data recorded by the Belle II experiment at the SuperKEKB asymmetric-energy collider. The neutral charm meson is searched for in the decay mode and combined with a properly charged identified lepton (electron or muon) to reconstruct this decay. No reconstruction of the second meson in the (4) event is performed. We obtain () = (2.29 0.05 0.08, in agreement with the world average of this decay. We also determine the ratio of the electron to muon branching fractions to be (/) = 1.04 0.05 0.03 and observe no deviation from lepton universality
Measurements of branching fractions and CP-violating charge asymmetries in multibody charmless decays reconstructed in 2019-2020 Belle II data
We report on measurements of branching fractions () and CP-violating charge asymmetries () of multibody charmless decays reconstructed by the Belle II experiment at the SuperKEKB electron-positron collider. We use a sample of collisions collected in 2019 and 2020 at the resonance and corresponding to fb of integrated luminosity. We use simulation to determine optimized event selections. The and distributions of the resulting samples are fit to determine signal yields of approximately 690, 840, and 380 decays for the channels , , and , respectively. These yields are corrected for efficiencies determined from simulation and control data samples to obtain , , , , , and . Results are consistent with previous measurements and demonstrate detector performance comparable with the best Belle results
Angular analysis of decays reconstructed in 2019-2020 Belle II data
We report on the first Belle II measurement of the branching fraction () and longitudinal polarization fraction () of decays. We reconstruct decays in a sample of SuperKEKB electron-positron collisions collected by the Belle II experiment in 2019 and 2020 at the (4S) resonance and corresponding to fb of integrated luminosity. We fit the distributions of the difference between expected and observed candidate energy, continuum-suppression variable, dipion masses, and angular distributions of the resulting samples, to determine a signal yield of events. The signal yields are corrected for efficiencies determined from simulation and control data samples to obtain , and . This first Belle II angular analysis yields results compatible with previous determinations, and indicates Belle II performance superior to early Belle results