Bayesian screening for feature selection Gould, A. Lawrence; Baumgartner, Richard; Zhao, Amanda
Journal of biopharmaceutical statistics,
11/2022, Letnik:
32, Številka:
6
Journal Article
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Biomedical applications such as genome-wide association studies screen large databases with high-dimensional features to identify rare, weakly expressed, and important continuous-valued features for ...subsequent detailed analysis. We describe an exact, rapid Bayesian screening approach with attractive diagnostic properties using a Gaussian random mixture model focusing on the missed discovery rate (the probability of failing to identify potentially informative features) rather than the false discovery rate ordinarily used with multiple hypothesis testing. The method provides the likelihood that a feature merits further investigation, as well as distributions of the effect magnitudes and the proportion of features with the same expected responses under alternative conditions. Important features include the dependence of the critical values on clinical and regulatory priorities and direct assessment of the diagnostic properties.
We analyze an ensemble of microlensing events from the 2015 Spitzer microlensing campaign, all of which were densely monitored by ground-based high-cadence survey teams. The simultaneous observations ...from Spitzer and the ground yield measurements of the microlensing parallax vector , from which compact constraints on the microlens properties are derived, including 25% uncertainties on the lens mass and distance. With the current sample, we demonstrate that the majority of microlenses are indeed in the mass range of M dwarfs. The planet sensitivities of all 41 events in the sample are calculated, from which we provide constraints on the planet distribution function. In particular, assuming a planet distribution function that is uniform in , where q is the planet-to-star mass ratio, we find a 95% upper limit on the fraction of stars that host typical microlensing planets of 49%, which is consistent with previous studies. Based on this planet-free sample, we develop the methodology to statistically study the Galactic distribution of planets using microlensing parallax measurements. Under the assumption that the planet distributions are the same in the bulge as in the disk, we predict that ∼1/3 of all planet detections from the microlensing campaigns with Spitzer should be in the bulge. This prediction will be tested with a much larger sample, and deviations from it can be used to constrain the abundance of planets in the bulge relative to the disk.
This book gives professionals in clinical research valuable information on the challenging issues of the design, execution, and management of clinical trials, and how to resolve these issues ...effectively. It also provides understanding and practical guidance on the application of contemporary statistical methods to contemporary issues in safety evaluation during medical product development. Each chapter provides sufficient detail to the reader to undertake the design and analysis of experiments at various stages of product development, including comprehensive references to the relevant literature. * Provides a guide to statistical methods and application in medical product development * Assists readers in undertaking design and analysis of experiments at various stages of product development * Features case studies throughout the book, as well as, SAS and R code
Based on high-resolution spectra obtained during gravitational microlensing events we present a detailed elemental abundance analysis of 32 dwarf and subgiant stars in the Galactic bulge. Combined ...with the sample of 26 stars from the previous papers in this series, we now have 58 microlensed bulge dwarfs and subgiants that have been homogeneously analysed. The results from the microlensed bulge dwarf stars in combination with other findings in the literature, in particular the evidence that the bulge has cylindrical rotation, indicate that the Milky Way could be an almost pure disk galaxy. The bulge would then just be a conglomerate of the other Galactic stellar populations, residing together in the central parts of the Galaxy, influenced by the Galactic bar.
Despite the expected advantages of appointing women to corporate leadership roles, empirical evidence provides mixed support for the positive relationship between women's representation in the top ...management team (TMT) and subsequent firm performance. Considering the evidence that female TMT members are often paid less than their male colleagues, this study examines the implications of a gender pay disparity for the relationship between women's representation in the TMT and firm performance. Our analysis that draws on TMT pay data in public Australian firms demonstrates that gender pay disparities within TMTs negatively moderate the relationship between women's representation in the TMT and subsequent firm performance. Specifically, when female TMT members are paid less than their male colleagues, and this gender pay disparity is large, women's representation in the TMT is negatively associated with firm performance.
The Routledge Handbook on American Prisons is an authoritative volume that provides an overview of the state of U.S. prisons and synthesizes the research on the many facets of the prison system. The ...United States is exceptional in its use of incarceration as punishment. It not only has the largest prison population in the world, but also the highest per-capita incarceration rate. Research and debate about mass incarceration continues to grow, with mounting bipartisan agreement on the need for criminal justice reform.
Divided into four parts (Prison Security, Operations, and Administration; Types of Offenders and Populations; Living and Dying in Prison; and Release, Reentry, and Reform), the volume explores the key issues fundamental to understanding the U.S. prison system, including the characteristics of facilities, inmate risk assessment and classification, prison administration and employment, for-profit prisons, special populations, overcrowding, prison health care, prison violence, the special circumstances of death row prisoners, collateral consequences of incarceration, prison programming, and parole. The final section examines reform efforts and ideas, and offers suggestions for future research and attention.
With contributions from leading correctional scholars this book is a valuable resource for scholars with an interest in U.S. prisons and the issues surrounding them. It is structured to serve scholars and graduate students studying corrections, penology, institutional corrections, and other related topics.
We present microlensing planet OGLE-2017-BLG-0173Lb, with planet-host mass ratio of either or , the lowest or among the lowest ever detected. The planetary perturbation is strongly detected, Δχ2 ∼ ...10000, because it arises from a bright (therefore, large) source passing over and enveloping the planetary caustic: a so-called "Hollywood" event. The factor ∼2.5 offset in q arises because of a previously unrecognized discrete degeneracy between Hollywood events in which the caustic is fully enveloped and those in which only one flank is enveloped, which we dub "Cannae" and "von Schlieffen," respectively. This degeneracy is "accidental" in that it arises from gaps in the data. Nevertheless, the fact that it appears in a Δχ2 = 10000 planetary anomaly is striking. We present a simple formalism to estimate the sensitivity of other Hollywood events to planets and show that they can lead to detections close to, but perhaps not quite reaching, the Earth/Sun mass ratio of . This formalism also enables an analytic understanding of the factor ∼2.5 offset in q between the Cannae and von Schlieffen solutions. The Bayesian estimates for the host mass, system distance, and planet-host projected separation are , , and , respectively. The two estimates of the planet mass are and . The measured lens-source relative proper motion will permit imaging of the lens in about 15 years or at first light on adaptive-optics imagers on next-generation telescopes. These will allow one to measure the host mass but probably will not be able to resolve the planet-host mass-ratio degeneracy.
•We provide a comprehensive review of phleboviruses vectored by sandflies in the Old World.•Toscana virus is the agent with the greatest known virulence for humans.•Several properties of these ...viruses make them candidates for emergence as human pathogens.•The possible future evolution and geographic spread of sandfly-borne phleboviruses are discussed.•We suggest potential studies for the discovery of antiviral drug and vaccines against these viruses.
Sandfly-borne phleboviruses may cause a transient febrile illness (sandfly fever) or more severe neuroinvasive disease. In the Old World, they are vectored by phlebotomine flies, which are widely distributed in the Mediterranean basin, North Africa, the Indian subcontinent, the Middle East and central Asia. High seroprevalence rates have been recorded in humans and domestic animals in areas where sandflies are present. Most published studies have focused on phlebovirus infections of travelers and of soldiers stationed in endemic areas, but the health impact on local populations should not be underestimated, as seroprevalence studies indicate massive circulation of these viruses, even if disease is seldom documented. Except for Toscana virus, which shows a marked neurotropism and is a leading cause of aseptic meningitis in endemic regions, phlebovirus infections are inadequately considered by physicians and are generally underestimated. However, several properties of these viruses suggest that they will extend their geographic range. First, changes in the areas occupied by sandflies as a result of climate change have a direct impact on the epidemiology of associated human and animal diseases. Second, phleboviruses exhibit a high mutation rate, and their tri-segmented genome is prone to reassortment and recombination. Third, distinct virus strains can be transmitted by the same arthropod species. Recent studies have documented the distribution of sandfly-borne phleboviruses in Western Europe, but data for Eastern Europe, the Middle East and Africa are very limited. With the goal of filling knowledge gaps and planning new research programs, we have examined available information and present it as a comprehensive review, with a specific focus on understudied regions. We also discuss the need to conduct studies aimed at developing new antiviral drugs and vaccines.
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