Simulation sample sizes for Monte Carlo partial EVPI calculations

Partial expected value of perfect information (EVPI) quantifies the value of removing uncertainty about unknown parameters in a decision model. EVPIs can be computed via Monte Carlo methods. An outer loop samples values of the parameters of interest, and an inner loop samples the remaining parameters from their conditional distribution. This nested Monte Carlo approach can result in biased estimates if small numbers of inner samples are used and can require a large number of model runs for accurate partial EVPI estimates. We present a simple algorithm to estimate the EVPI bias and confidence interval width for a specified number of inner and outer samples. The algorithm uses a relatively small number of model runs (we suggest approximately 600), is quick to compute, and can help determine how many outer and inner iterations are needed for a desired level of accuracy. We test our algorithm using three case studies. (C) 2010 Elsevier B.V. All rights reserved

Calculating partial expected value of perfect information via Monte Carlo sampling algorithms

Partial expected value of perfect information (EVPI) calculations can quantify the value of learning about particular subsets of uncertain parameters in decision models. Published case studies have used different computational approaches. This article examines the computation of partial EVPI estimates via Monte Carlo sampling algorithms. The mathematical definition shows 2 nested expectations, which must be evaluated separately because of the need to compute a maximum between them. A generalized Monte Carlo sampling algorithm uses nested simulation with an outer loop to sample parameters of interest and, conditional upon these, an inner loop to sample remaining uncertain parameters. Alternative computation methods and shortcut algorithms are discussed and mathematical conditions for their use considered. Maxima of Monte Carlo estimates of expectations are biased upward, and the authors show that the use of small samples results in biased EVPI estimates. Three case studies illustrate 1) the bias due to maximization and also the inaccuracy of shortcut algorithms 2) when correlated variables are present and 3) when there is nonlinearity in net benefit functions. If relatively small correlation or nonlinearity is present, then the shortcut algorithm can be substantially inaccurate. Empirical investigation of the numbers of Monte Carlo samples suggests that fewer samples on the outer level and more on the inner level could be efficient and that relatively small numbers of samples can sometimes be used. Several remaining areas for methodological development are set out. A wider application of partial EVPI is recommended both for greater understanding of decision uncertainty and for analyzing research priorities

Distance Education in Alberta public colleges.

The intent of this study was to analyse and describe the attitudes and decision making criteria utilized by senior decision makers within Alberta's public colleges and how they affect the adoption or rejection of distance education within these institutions. The analysis into the attitudes and decision making criteria was conducted using five central research questions: 1.How aware or knowledgeable are senior decision makers of distance education within their institution? 2.Have feelings towards distance education changed or evolved? 3.What are the future intentions for distance education within each institution? 4.What are the main sources of information that are utilized by senior decision makers to make decisions regarding distance education? 5.How do senior decision makers evaluate the sources of information they use to make decisions? This study will provide an understanding and focus for present and future distance education programs that would be similar in nature. The insights gained from this study will have significant implications for the planning, development, and design of distance education curricula and systems within Alberta's public colleges. The thesis begins with an introduction into the current contextual conditions present within the province of Alberta which describes the changes occurring in the economic climate, technology, increased public demand and changes in Alberta’s demographics. Chapter two consists of four sections: Competition and Demand in Alberta’s Public Colleges, Innovation Decision Process, Forces that Influence Decision Making Processes and Leaders as Change Agents. These four sections serve to provide a framework for an inquiry into previous research related to this study, and contextual insight into the present technological, social and political climate within Alberta. Chapter three serves to describe and inform the reader of how the study was conducted. Chapter four presents the analysis of the results obtained from the information collected as well as the findings in relation to these results. The analysis of the findings is guided by the five themes presented in the five central research questions. In chapter five the conclusions, implications, and recommendations for the findings derived from in chapter four are discussed. The principle conclusions that can be drawn from this study are: 1.Attitudes towards distance education by senior decision makers in Alberta's public colleges is generally positive, however, there is a significant amount of ambiguity regarding distance education. 2.There are significant external pressures forcing Alberta’s public colleges to get involved in distance education. 3.Distance education within Alberta’s public colleges will grow in the future. 4.There is an overriding technocratic view of distance education. 5. There is a pre-occupation with economic efficiencies rather than effectiveness as it relates to distance education

The effect of core-shell engineering on the energy product of magnetic nanometals.

Solution-based growth of magnetic FePt-FeCo (core-shell) nanoparticles with a controllable shell thickness has been demonstrated. The transition from spin canting to exchange coupling of FePt-FeCo core-shell nanostructures leads to a 28% increase in the coercivity (12.8 KOe) and a two-fold enhancement in the energy product (9.11 MGOe)

The Fiber Optic Reel System: A Compact Deployment Solution for Tethered Live-Telemetry Deep-Sea Robots and Sensors

Tethered deep-sea robots and instrument platforms, such as Remotely Operated Vehicles (ROVs) and vertical-profiling or towed instrument arrays, commonly rely on fiber optics for real-time data transmission. Fiber optic tethers used for these applications are either heavily reinforced load-bearing cables used to support lifting and pulling, or bare optical fibers used in non-load bearing applications. Load-bearing tethers directly scale operations for deep-sea robots as the cable diameter, mass, and length typically require heavy winches and large surface support vessels to operate, and also guide the design of the deep-sea robot itself. In an effort to dramatically reduce the physical scale and operational overhead of tethered live-telemetry deep-sea robots and sensors, we have developed the Fiber Optic Reel System (FOReelS). FOReelS utilizes a customized electric fishing reel outfitted with a proprietary hollow-core braided fiber optic fishing line and mechanical termination assembly (FOFL), which offers an extremely small diameter (750 μm) load-bearing (90 lb/400 N breaking strength) tether to support live high-bandwidth data transmission as well as fiber optic sensing applications. The system incorporates a novel epoxy potted data payload system (DPS) that includes high-definition video, integrated lighting, rechargeable battery power, and gigabit ethernet fiber optic telemetry. In this paper we present the complete FOReelS design and field demonstrations to depths exceeding 780 m using small coastal support vessels of opportunity. FOReelS is likely the smallest form factor live-telemetry deep-sea exploration tool currently in existence, with a broad range of future applications envisioned for oceanographic sensing and communication

Mobile Authentication Assurance Statement (MAAS) Draft Specification

Authentication assurance is a statement of the level of protection that the authenticator enforces to assure that a user retains control of the credentials used in authentication. Protected secret credentials enable user authentication at high levels of assurance. This specification describes the format of a message for mobile assurance along with a healthcare provider use case, involving the user’s acquisition and operation of an app on a smartphone that uses the statement in an authentication protocol

GUDMAP - An Online GenitoUrinary Resource

The GenitoUrinary Development Molecular Anatomy Project (GUDMAP) is a consortium of laboratories working to provide the scientific and medical community with gene expression data and tools to facilitate research (see "www.gudmap.org":http://www.gudmap.org). The data provided by GUDMAP includes large _in situ_ hybridization screens (wholemount and section) and expression microarray analysis of components of the developing mouse urogenital system (including laser-captured material and FACS-isolated cells from transgenic reporter mice). In addition, a high-resolution anatomy ontology has been developed by members of the GUDMAP consortium to describe the subcompartments of the developing murine genitourinary tract. 

The GUDMAP Database Development Team and Editorial Office - both based in Edinburgh - function to ensure submission, curation, storage and presentation of the data submitted by the GUDMAP consortium. Our collective aim is twofold: 1) to simplify the process of submission so that data is publically available as soon as it is produced; and 2) to organize this information in a database and ensure that the online interface is continuously available and easy to use. Thus far, we have developed a range of tools that help both the submitter and the end user. These include: an online annotation tool that simplifies _in situ_ data submission through an ontology-based graphical user interface; a database interface that allows users to browse and query expression data, and to filter data by organ system; a heat-map display of microarray data and analyses. Furthermore, the Edinburgh team has developed a GUDMAP Disease Database that queries associations between genes, genitourinary diseases, and renal/urinary and reproductive phenotypes. In collaboration with GUDMAP consortium members at the CCHMC (Cincinnati Children's Hospital Medical Center), the Disease Database is being extended to include mammalian phenotypes mapped to OMIM entries. 

By virtue of its impressive dataset and its ease of use we hope that the GUDMAP Website will continue to serve as a powerful resource for biologists, clinicians and bioinformaticians with an interest in the urogenital system

Protein quality and quantity influence the effect of dietary fat on weight gain and tissue partitioning via host-microbiota changes

ACKNOWLEDGMENTS This work was supported by a research grant from Science Foundation Ireland (SFI) under grant SFI/16/BBSRC/3389, BBSRC under grant number BB/ P009875/1 (to K.N.N. and J.R.S.), and in part by SFI and the Department of Agriculture, Food and Marine under grant 16/RC/3835 (to VistaMilk). We thank Conall Strain, David Mannion, and John Leech for contributing to the metabolomics analysis. We thank Alina Kondrashina for help with the Milliplex system.Peer reviewedPublisher PD