-
作者：Chiarucci, Alessandro; Di Biase, Rosa Maria; Fattorini, Lorenzo; Marcheselli, Marzia; Pisani, Caterina
作者单位：University of Bologna; Tuscia University; University of Siena
摘要：The lists of species obtained by purposive sampling by field ecologists can be used to improve the sample-based estimation of species richness. A new estimator is here proposed as a modification of the difference estimator in which the species inclusion probabilities are estimated by means of the species frequencies from incidence data. If the species list used to support the estimation is complete the estimator guesses the true richness without error. In the case of incomplete lists, the esti...
-
作者：Weber, Sebastian; Gelman, Andrew; Lee, Daniel; Betancourt, Michael; Vehtari, Aki; Racine-Poon, Amy
作者单位：Novartis; Columbia University; Aalto University
摘要：Throughout the different phases of a drug development program, randomized trials are used to establish the tolerability, safety and efficacy of a candidate drug. At each stage one aims to optimize the design of future studies by extrapolation from the available evidence at the time. This includes collected trial data and relevant external data. However, relevant external data are typically available as averages only, for example, from trials on alternative treatments reported in the literature...
-
作者：Rodriguez-Girondo, Mar; Salo, Perttu; Burzykowski, Tomasz; Perola, Markus; Houwing-Duistermaat, Jeanine; Mertens, Bart
作者单位：Leiden University - Excl LUMC; Leiden University; Leiden University Medical Center (LUMC); Finland National Institute for Health & Welfare; Hasselt University; University of Leeds
摘要：Enriching existing predictive models with new biomolecular markers is an important task in the new multi-omic era. Clinical studies increasingly include new sets of omic measurements which may prove their added value in terms of predictive performance. We introduce a two-step approach for the assessment of the added predictive ability of omic predictors, based on sequential double cross-validation and regularized regression models. We propose several performance indices to summarize the two-st...
-
作者：Ding, Ying; Li, Ying Grace; Liu, Yushi; Ruberg, Stephen J.; Hsu, Jason C.
作者单位：Pennsylvania Commonwealth System of Higher Education (PCSHE); University of Pittsburgh; Eli Lilly; Lilly Research Laboratories; University System of Ohio; Ohio State University
摘要：Our research is for finding SNPs that are predictive of treatment efficacy, to decide which subgroup (with enhanced treatment efficacy) to target in drug development. Testing SNPs for lack of association with treatment outcome is inherently challenging, because any linkage disequilibrium between a noncausal SNP with a causal SNP, however small, makes the zero-null (no association) hypothesis technically false. Control of Type I error rate in testing such null hypotheses are therefore difficult...
-
作者：Cheng, Yicheng; Dundar, Murat; Mohler, George
作者单位：Purdue University System; Purdue University; Purdue University in Indianapolis
摘要：Epidemic-type aftershock sequence (ETAS) point process is a common model for the occurrence of earthquake events. The ETAS model consists of a stationary background Poisson process modeling spontaneous earthquakes and a triggering kernel representing the space-time-magnitude distribution of aftershocks. Popular nonparametric methods for estimation of the background intensity include histograms and kernel density estimators. While these methods are able to capture local spatial heterogeneity in...
-
作者：Golchi, Shirin; Lockhart, Richard
作者单位：Simon Fraser University
摘要：The statistical procedure used in the search for new particles is investigated in this paper. The discovery of the Higgs particles is used to lay out the problem and the existing procedures. A Bayesian hierarchical model is proposed to address inference about the parameters of interest while incorporating uncertainty about the nuisance parameters into the model. In addition to inference, a decision making procedure is proposed. A loss function is introduced that mimics the important features o...
-
作者：Huang, Yen-Tsung
作者单位：Academia Sinica - Taiwan
摘要：Mediation analysis has become a popular practice in biomedical research. We conduct mediation analyses to investigate whether epigenetic variations mediate the effect of socioeconomic disadvantage on adiposity. Mediation effects can be expressed as a product of two parameters: one for the exposure-mediator association and the other for the mediator-outcome association conditional on the exposure. Under multi-mediator models, we study joint significance tests which examine the two parameters se...
-
作者：Tao, Yebin; Wang, Lu; Almirall, Daniel
作者单位：University of Michigan System; University of Michigan; University of Michigan System; University of Michigan
摘要：Dynamic treatment regimes (DTRs) are sequences of treatment decision rules, in which treatment may be adapted over time in response to the changing course of an individual. Motivated by the substance use disorder (SUD) study, we propose a tree-based reinforcement learning (T-RL) method to directly estimate optimal DTRs in a multi-stage multi-treatment setting. At each stage, T-RL builds an unsupervised decision tree that directly handles the problem of optimization with multiple treatment comp...
-
作者：Luo, Xiangyu; Wei, Yingying
作者单位：Chinese University of Hong Kong; Chinese University of Hong Kong
摘要：Gene expression is largely controlled by transcription factors (TFs) in a collaborative manner. Therefore, an understanding of TF collaboration is crucial for the elucidation of gene regulation. The co-activation of TFs can be represented by networks. These networks are dynamic in diverse biological conditions and heterogeneous across the genome within each biological condition. Existing methods for construction of TF networks lack solid statistical models, analyze each biological condition se...
-
作者：Franks, Alexander M.; Markowetz, Florian; Airoldi, Edoardo M.
作者单位：University of California System; University of California Santa Barbara; University of Cambridge; Cancer Research UK; CRUK Cambridge Institute; Pennsylvania Commonwealth System of Higher Education (PCSHE); Temple University
摘要：Improving current models and hypotheses of cellular pathways is one of the major challenges of systems biology and functional genomics. There is a need for methods to build on established expert knowledge and reconcile it with results of new high-throughput studies. Moreover, the available sources of data are heterogeneous, and the data need to be integrated in different ways depending on which part of the pathway they are most informative for. In this paper, we introduce a compartment specifi...
