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作者：O'Sullivan, Finbarr; Muzi, Mark; Mankoff, David A.; Eary, Janet F.; Spence, Alexander M.; Krohn, Kenneth A.
作者单位：University College Cork; University of Washington; University of Washington Seattle; University of Pennsylvania; University of Alabama System; University of Alabama Birmingham
摘要：Most radiotracers used in dynamic positron emission tomography ( PET) scanning act in a linear time-invariant fashion so that the measured time-course data are a convolution between the time course of the tracer in the arterial supply and the local tissue impulse response, known as the tissue residue function. In statistical terms the residue is a life table for the transit time of injected radiotracer atoms. The residue provides a description of the tracer kinetic information measurable by a ...
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作者：Schnitzer, Mireille E.; van der Laan, Mark J.; Moodie, Erica E. M.; Platt, Robert W.
作者单位：Universite de Montreal; University of California System; University of California Berkeley; McGill University
摘要：The PROmotion of Breastfeeding Intervention Trial (PROBIT) cluster-randomized a program encouraging breastfeeding to new mothers in hospital centers. The original studies indicated that this intervention successfully increased duration of breastfeeding and lowered rates of gastrointestinal tract infections in newborns. Additional scientific and popular interest lies in determining the causal effect of longer breastfeeding on gastrointestinal infection. In this study, we estimate the expected i...
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作者：Sun, Zhaonan; Kuczek, Thomas; Zhu, Yu
作者单位：Purdue University System; Purdue University
摘要：The accurate quantification of gene expression levels is crucial for transcriptome study. Microarray platforms are commonly used for simultaneously interrogating thousands of genes in the past decade, and recently RNA-Seq has emerged as a promising alternative. The gene expression measurements obtained by microarray and RNA-Seq are, however, subject to various measurement errors. A third platform called qRT-PCR is acknowledged to provide more accurate quantification of gene expression levels t...
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作者：Meyer, Sebastian; Held, Leonhard
作者单位：University of Zurich; Swiss School of Public Health (SSPH+)
摘要：Short-time human travel behaviour can be described by a power law with respect to distance. We incorporate this information in space-time models for infectious disease surveillance data to better capture the dynamics of disease spread. Two previously established model classes are extended, which both decompose disease risk additively into endemic and epidemic components: a spatio-temporal point process model for individual-level data and a multivariate time-series model for aggregated count da...
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作者：Wilson, James D.; Wang, Simi; Mucha, Peter J.; Bhamidi, Shankar; Nobel, Andrew B.
作者单位：University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina; University of North Carolina Chapel Hill; University of North Carolina; University of North Carolina Chapel Hill
摘要：A common and important problem arising in the study of networks is how to divide the vertices of a given network into one or more groups, called communities, in such a way that vertices of the same community are more interconnected than vertices belonging to different ones. We propose and investigate a testing based community detection procedure called Extraction of Statistically Significant Communities (ESSC). The ESSC procedure is based on p-values for the strength of connection between a si...
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作者：Ge, Tian; Mueller-Lenke, Nicole; Bendfeldt, Kerstin; Nichols, Thomas E.; Johnson, Timothy D.
作者单位：Fudan University; University of Warwick; University of Basel; University of Warwick; University of Warwick; University of Michigan System; University of Michigan
摘要：Magnetic resonance imaging (MRI) plays a vital role in the scientific investigation and clinical management of multiple sclerosis. Analyses of binary multiple sclerosis lesion maps are typically mass univariate and conducted with standard linear models that are ill suited to the binary nature of the data and ignore the spatial dependence between nearby voxels (volume elements). Smoothing the lesion maps does not entirely eliminate the non-Gaussian nature of the data and requires an arbitrary c...
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作者：Guolo, Annamaria; Varin, Cristiano
作者单位：University of Verona; Universita Ca Foscari Venezia
摘要：Bounded time series consisting of rates or proportions are often encountered in applications. This manuscript proposes a practical approach to analyze bounded time series, through a beta regression model. The method allows the direct interpretation of the regression parameters on the original response scale, while properly accounting for the heteroskedasticity typical of bounded variables. The serial dependence is modeled by a Gaussian copula, with a correlation matrix corresponding to a stati...
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作者：Fan, Yingying; Foutz, Natasha; James, Gareth M.; Jank, Wolfgang
作者单位：University of Southern California; University of Virginia; State University System of Florida; University of South Florida
摘要：While functional regression models have received increasing attention recently, most existing approaches assume both a linear relationship and a scalar response variable. We suggest a new method, Functional Response Additive Model Estimation (FRAME), which extends the usual linear regression model to situations involving both functional predictors, Xj (t), scalar predictors, Z(k), and functional responses, Y(s). Our approach uses a penalized least squares optimization criterion to automaticall...
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作者：Wang, Xuejing; Nan, Bin; Zhu, Ji; Koeppe, Robert
作者单位：University of Michigan System; University of Michigan; University of Michigan System; University of Michigan; University of Michigan System; University of Michigan
摘要：The primary motivation and application in this article come from brain imaging studies on cognitive impairment in elderly subjects with brain disorders. We propose a regularized Haar wavelet-based approach for the analysis of three-dimensional brain image data in the framework of functional data analysis, which automatically takes into account the spatial information among neighboring voxels. We conduct extensive simulation studies to evaluate the prediction performance of the proposed approac...
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作者：Cervone, Daniel; Pillai, Natesh S.; Pati, Debdeep; Berbeco, Ross; Lewis, John Henry
作者单位：Harvard University; State University System of Florida; Florida State University; Harvard University; Harvard University Medical Affiliates; Dana-Farber Cancer Institute; Brigham & Women's Hospital; Harvard University; Harvard Medical School
摘要：Lung tumor tracking for radiotherapy requires real-time, multiple-step ahead forecasting of a quasi-periodic time series recording instantaneous tumor locations. We introduce a location-mixture autoregressive (LMAR) process that admits multimodal conditional distributions, fast approximate inference using the EM algorithm and accurate multiple-step ahead predictive distributions. LMAR outperforms several commonly used methods in terms of out-of-sample prediction accuracy using clinical data fr...
