498 research outputs found
Statutory Responses to Interested Directors\u27 Transactions: A Watering Down of Fiduciary Standards
Galaxy Peculiar Velocities From Large-Scale Supernova Surveys as a Dark Energy Probe
Upcoming imaging surveys such as the Large Synoptic Survey Telescope will
repeatedly scan large areas of sky and have the potential to yield
million-supernova catalogs. Type Ia supernovae are excellent standard candles
and will provide distance measures that suffice to detect mean pairwise
velocities of their host galaxies. We show that when combining these distance
measures with photometric redshifts for either the supernovae or their host
galaxies, the mean pairwise velocities of the host galaxies will provide a dark
energy probe which is competitive with other widely discussed methods. Adding
information from this test to type Ia supernova photometric luminosity
distances from the same experiment, plus the cosmic microwave background power
spectrum from the Planck satellite, improves the Dark Energy Task Force Figure
of Merit by a factor of 1.8. Pairwise velocity measurements require no
additional observational effort beyond that required to perform the traditional
supernova luminosity distance test, but may provide complementary constraints
on dark energy parameters and the nature of gravity. Incorporating additional
spectroscopic redshift follow-up observations could provide important dark
energy constraints from pairwise velocities alone. Mean pairwise velocities are
much less sensitive to systematic redshift errors than the luminosity distance
test or weak lensing techniques, and also are only mildly affected by
systematic evolution of supernova luminosity.Comment: 18 pages; 4 figures; 4 tables; replaced to match the accepted versio
Heritability in genetic heart disease : the role of genetic background
Background Mutations in genes encoding ion channels or sarcomeric proteins are an important cause of hereditary cardiac disease. However, the severity of the resultant disease varies considerably even among those with an identical mutation. Such clinical variation is often thought to be explained largely by differences in genetic background or ` modifier genes'. We aimed to test the prediction that identical genetic backgrounds result in largely similar clinical expression of a cardiac disease causing mutation, by studying the clinical expression of mutations causing cardiac disease in monozygotic twins. Methods We compared first available clinical information on 46 monozygotic twin pairs and 59 control pairs that had either a hereditary cardiomyopathy or channelopathy. Results Despite limited power of this study, we found significant heritability for corrected QT interval (QTc) in long QT syndrome (LQTS). We could not detect significant heritability for structural traits, but found a significant environmental effect on thickness of the interventricular septum in hypertrophic cardiomyopathy. Conclusions Our study confirms previously found robust heritability for electrical traits like QTc in LQTS, and adds information on low or lacking heritability for structural traits in heritable cardiomyopathies. This may steer the search for genetic modifiers in heritable cardiac disease.Peer reviewe
Long-term cardiac follow-up of athletes infected with SARS-CoV-2 after resumption of elite-level sports
OBJECTIVE: Longitudinal consequences and potential interactions of COVID-19 and elite-level sports and exercise are unclear. Therefore, we determined the long-term detrimental cardiac effects of the interaction between SARS-CoV-2 infection and the highest level of sports and exercise.METHODS: This prospective controlled study included elite athletes from the Evaluation of Lifetime participation in Intensive Top-level sports and Exercise cohort. Athletes infected with SARS-CoV-2were offered structured, additional cardiovascular screenings, including cardiovascular MRI (CMR). We compared ventricular volumes and function, late gadolinium enhancement (LGE) and T1 relaxation times, between infected and non-infected elite athletes, and collected follow-up data on cardiac adverse events, ventricular arrhythmia burden and the cessation of sports careers.RESULTS: We included 259 elite athletes (mean age 26±5 years; 40% women), of whom 123 were infected (9% cardiovascular symptoms) and 136 were controls. We found no differences in function and volumetric CMR parameters. Four infected athletes (3%) demonstrated LGE (one reversible), compared with none of the controls. During the 26.7 (±5.8) months follow-up, all four athletes resumed elite-level sports, without an increase in ventricular arrhythmias or adverse cardiac remodelling. None of the infected athletes reported new cardiac symptoms or events. The majority (n=118; 96%) still participated in elite-level sports; no sports careers were terminated due to SARS-CoV-2.CONCLUSIONS: This prospective study demonstrates the safety of resuming elite-level sports after SARS-CoV-2 infection. The medium-term risks associated with SARS-CoV-2 infection and elite-level sports appear low, as the resumption of elite sports did not lead to detrimental cardiac effects or increases in clinical events, even in the four elite athletes with SARS-CoV-2 associated myocardial involvement.</p
Genomic, Pathway Network, and Immunologic Features Distinguishing Squamous Carcinomas
This integrated, multiplatform PanCancer Atlas study co-mapped and identified distinguishing
molecular features of squamous cell carcinomas (SCCs) from five sites associated with smokin
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