University of Waterloo

About: University of Waterloo is a education organization based out in Waterloo, Ontario, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 36093 authors who have published 93906 publications receiving 2948139 citations. The organization is also known as: UW & uwaterloo.

The Practical Implementation of Bayesian Model Selection

Abstract: In principle, the Bayesian approach to model selection is straightforward. Prior probability distributions are used to describe the uncertainty surrounding all unknowns. After observing the data, the posterior distribution provides a coherent post data summary of the remaining uncertainty which is relevant for model selection. However, the practical implementation of this approach often requires carefully tailored priors and novel posterior calculation methods. In this article, we illustrate some of the fundamental practical issues that arise for two different model selection problems: the variable selection problem for the linear model and the CART model selection problem. Hugh Chipman is Associate Professor of Statistics, Department of Statistics and Actuarial Science, University of Waterloo, Waterloo, ON N2L 3G1, Canada; email: hachipman@uwaterloo.ca. Edward I. George is Professor of Statistics, Department of Statistics, The Wharton School of the University of Pennsylvania, 3620 Locust Walk, Philadelphia, PA 19104-6302, U.S.A; email: edgeorge@wharton.upenn.edu. Robert E. McCulloch is Professor of Statistics, Graduate School of Business, University of Chicago, 1101 East 58th Street, Chicago, IL, U.S.A; email: Robert.McCulloch@gsb.uchicago.edu. This work was supported by NSF grant DMS-98.03756 and Texas ARP grant 003658.690.

Rapid determination of myosin heavy chain expression in rat, mouse, and human skeletal muscle using multicolor immunofluorescence analysis.

Abstract: Skeletal muscle is a heterogeneous tissue comprised of fibers with different morphological, functional, and metabolic properties. Different muscles contain varying proportions of fiber types; therefore, accurate identification is important. A number of histochemical methods are used to determine muscle fiber type; however, these techniques have several disadvantages. Immunofluorescence analysis is a sensitive method that allows for simultaneous evaluation of multiple MHC isoforms on a large number of fibers on a single cross-section, and offers a more precise means of identifying fiber types. In this investigation we characterized pure and hybrid fiber type distribution in 10 rat and 10 mouse skeletal muscles, as well as human vastus lateralis (VL) using multicolor immunofluorescence analysis. In addition, we determined fiber type-specific cross-sectional area (CSA), succinate dehydrogenase (SDH) activity, and α-glycerophosphate dehydrogenase (GPD) activity. Using this procedure we were able to easily identify pure and hybrid fiber populations in rat, mouse, and human muscle. Hybrid fibers were identified in all species and made up a significant portion of the total population in some rat and mouse muscles. For example, rat mixed gastrocnemius (MG) contained 12.2% hybrid fibers whereas mouse white tibialis anterior (WTA) contained 12.1% hybrid fibers. Collectively, we outline a simple and time-efficient method for determining MHC expression in skeletal muscle of multiple species. In addition, we provide a useful resource of the pure and hybrid fiber type distribution, fiber CSA, and relative fiber type-specific SDH and GPD activity in a number of rat and mouse muscles.

The WiggleZ Dark Energy Survey: survey design and first data release

Abstract: The WiggleZ Dark Energy Survey is a survey of 240 000 emission-line galaxies in the distant Universe, measured with the AAOmega spectrograph on the 3.9-m Anglo-Australian Telescope (AAT). The primary aim of the survey is to precisely measure the scale of baryon acoustic oscillations (BAO) imprinted on the spatial distribution of these galaxies at look-back times of 4–8 Gyr. The target galaxies are selected using ultraviolet (UV) photometry from the Galaxy Evolution Explorer satellite, with a flux limit of NUV < 22.8 mag . We also require that the targets are detected at optical wavelengths, specifically in the range 20.0 < r < 22.5 mag . We use the Lyman break method applied to the UV colours, with additional optical colour limits, to select high-redshift galaxies. The galaxies generally have strong emission lines, permitting reliable redshift measurements in relatively short exposure times on the AAT. The median redshift of the galaxies is z_(med)= 0.6 . The redshift range containing 90 per cent of the galaxies is 0.2 < z < 1.0 . The survey will sample a volume of ~1 Gpc^3 over a projected area on the sky of 1000 deg^2, with an average target density of 350 deg^(−2). Detailed forecasts indicate that the survey will measure the BAO scale to better than 2 per cent and the tangential and radial acoustic wave scales to approximately 3 and 5 per cent, respectively. Combining the WiggleZ constraints with existing cosmic microwave background measurements and the latest supernova data, the marginalized uncertainties in the cosmological model are expected to be σ(Ω_m) = 0.02 and σ(w) = 0.07 (for a constant w model). The WiggleZ measurement of w will constitute a robust, precise and independent test of dark energy models. This paper provides a detailed description of the survey and its design, as well as the spectroscopic observations, data reduction and redshift measurement techniques employed. It also presents an analysis of the properties of the target galaxies, including emission-line diagnostics which show that they are mostly extreme starburst galaxies, and Hubble Space Telescope images, which show that they contain a high fraction of interacting or distorted systems. In conjunction with this paper, we make a public data release of data for the first 100 000 galaxies measured for the project.

High-Performance Anode Materials for Rechargeable Lithium-Ion Batteries

Abstract: Transformational changes in battery technologies are critically needed to enable the effective use of renewable energy sources, such as solar and wind, and to allow for the expansion of the electrification of vehicles. Developing high-performance batteries is critical to meet these requirements, which certainly relies on material breakthroughs. This review article presents the recent progresses and challenges in discovery of high-performance anode materials for Li-ion batteries related to their applications in future electrical vehicles and grid energy storage. The advantages and disadvantages of a series of anode materials are highlighted.

Aggregation of inequalities in integer programming.

Abstract: Given an m $\times$ n zero-one matrix $\underset\tilde\to A$ we ask whether there is a single linear inequality $\underset\tilde\to a \underset\tilde\to x \leq b$ whose zero-one solutions are precisely the zero-one solutions of $\underset\tilde\to A \underset\tilde\to x \leq e$. We develop an algorithm for answering this question in O(m$n^2$) steps and investigate other related problems. Our results may be interpreted in terms of graph theory and threshold logic.