Search Results
Results 1 - 50 of 3006
1 2 3 4 5 6 7 8 9 10 >
Ingle Atul A Department of Electrical and Computer Engineering, University of Wisconsin-Madison, Madison WI 53706, USA. ; Department of Medical Physics, University of Wisconsin-Madison, Madison WI 53705, - - 2015
This paper discusses the development of a slope estimation algorithm called MAPSlope for piecewise linear data that is corrupted by Gaussian noise. The number and locations of slope change points (also known as breakpoints) are assumed to be unknown a priori though it is assumed that the possible range of ...
Mwaffo Violet V Department of Mechanical and Aerospace Engineering, New York University Polytechnic School of Engineering, Brooklyn, NY, - - 2015
Zebrafish are gaining momentum as a laboratory animal species for the investigation of several functional and dysfunctional biological processes. Mathematical models of zebrafish behaviour are expected to considerably aid in the design of hypothesis-driven studies by enabling preliminary in silico tests that can be used to infer possible experimental outcomes ...
Wang Xiao-Feng XF Department of Quantitative Health Sciences / Biostatistics Section, Cleveland Clinic Lerner Research Institute, Cleveland, OH 44195, - - 2015
This paper is motivated by a wide range of background correction problems in gene array data analysis, where the raw gene expression intensities are measured with error. Estimating a conditional density function from the contaminated expression data is a key aspect of statistical inference and visualization in these studies. We ...
Vexler Albert A Department of Biostatistics, New York State University at Buffalo, 715 Kimball Tower, 3435 Main Street, Buffalo, NY, 14214, USA, - - 2015
The aim of this chapter is to review and examine different methods in order to display correct and efficient statistical techniques based on complete/incomplete data subject to different sorts of measurement error (ME) problems. Instrument inaccuracies, biological variations, and/or errors in questionnaire-based self-report data can lead to significant MEs in ...
Pekala Ronald J RJ a Coatesville Veterans Administration Medical Center , Pennsylvania , - - 2015
Abstract This study sought to replicate an earlier study wherein imagery vividness before and during a phenomenological hypnotic assessment procedure was assessed, while also measuring trance (hypnoidal) state effects and several other variables. Correlational and regression analyses for that study suggested that imagery vividness during hypnotism was predicted by combined ...
Hansen Thomas F TF Department of Biology, Centre for Ecological and Evolutionary Synthesis, University of Oslo, P.B. 1066, Blindern, Oslo, 0316, Norway, - - 2015
Measurement is the assignment of numbers to reality, and valid measurement requires that these numbers represent relevant aspects of reality. I discuss epistatic gene interactions from a measurement-theoretical perspective and argue that the standard measurements of epistasis in classical quantitative genetics have failed to capture aspects of epistasis that are ...
Wagner Günter P GP Department of Ecology and Evolutionary Biology, and Systems Biology Institute, Yale University, 840 West Campus Drive, West Haven, CT, 06516, USA, - - 2015
Traditionally statistical interactions and epistasis are defined with respect to the ANOVA model of additive effects; that is, epistasis is defined as a deviation from the additive mode of combining main effects of gene substitutions. Furthermore, the definition is relative to a particular scale and epistasis can potentially be eliminated ...
Liu Jie J Department of Computer Sciences, University of - - 2014
It has been shown that graphical models can be used to leverage the dependence in large-scale multiple testing problems with significantly improved performance (Sun & Cai, 2009; Liu et al., 2012). These graphical models are fully parametric and require that we know the parameterization of f 1 - the density ...
Ghanbarnejad Fakhteh F Max Planck Institute for the Physics of Complex Systems, Dresden, Germany - - 2014
It is well accepted that adoption of innovations are described by S-curves (slow start, accelerating period and slow end). In this paper, we analyse how much information on the dynamics of innovation spreading can be obtained from a quantitative description of S-curves. We focus on the adoption of linguistic innovations ...
Gupta Ankit A Department of Biosystems Science and Engineering, ETH Zurich, Mattenstrasse 26, 4058 Basel, - - 2014
We consider the problem of estimating parameter sensitivity for Markovian models of reaction networks. Sensitivity values measure the responsiveness of an output with respect to the model parameters. They help in analysing the network, understanding its robustness properties and identifying the important reactions for a specific output. Sensitivity values are ...
Volz Erik M - - 2014
Many population genetic models have been developed for the purpose of inferring population size and growth rates from random samples of genetic data. We examine two popular approaches to this problem, the coalescent and the birth–death-sampling model (BDM), in the context of estimating population size and birth rates in a ...
Chi Eric C EC Department of Electrical and Computer Engineering, Rice University, Texas, - - 2014
Estimation of a covariance matrix or its inverse plays a central role in many statistical methods. For these methods to work reliably, estimated matrices must not only be invertible but also well-conditioned. The current paper introduces a novel prior to ensure a well-conditioned maximum a posteriori (MAP) covariance estimate. The ...
Solberg Svein S Norwegian Forest and Landscape Institute, P.O. Box 115, 1431 Ås, - - 2014
There is a need for new satellite remote sensing methods for monitoring tropical forest carbon stocks. Advanced RADAR instruments on board satellites can contribute with novel methods. RADARs can see through clouds, and furthermore, by applying stereo RADAR imaging we can measure forest height and its changes. Such height changes ...
Zhang Yajun - - 2014
In this paper, the challenging issue of estimating virtual unmodeled dynamics is addressed. A novel estimation algorithm based on historical data and the output of low-order approximation models for virtual un-modeled dynamics is presented. In particular, the virtual un-modeled dynamics are decomposed into known and unknown parts, where only the ...
Bakowies Dirk - - 2014
The ATOMIC protocol is a quantum-chemical thermochemistry protocol designed to obtain accurate atomization energies and derived heats of formation. It reduces errors of computationally tractable composite schemes through the use of bond separation reactions, which are implemented in a consistent ab initio framework. The present work explores possible simplification of ...
Villamor Eduardo E Department of Epidemiology, University of Michigan School of Public Health , Ann Arbor, MI , USA - - 2014
Abstract Background: Anthropometric studies often include replicates of each measurement to decrease error. The optimal method to combine these measurements is uncertain. Aim: To identify the optimal method to combine replicate measures for analysis. Methods: The authors carried out 10 000 Monte Carlo simulations to explore the effect of six approaches ...
Björnsson Marcus A MA AstraZeneca R&D, 15185, Södertälje, Sweden, - - 2014
Informative dropout can lead to bias in statistical analyses if not handled appropriately. The objective of this simulation study was to investigate the performance of nonlinear mixed effects models with regard to bias and precision, with and without handling informative dropout. An efficacy variable and dropout depending on that efficacy ...
Wang Xiaoguang X School of Mathematical Sciences, Dalian University of Technology, Dalian, Liaoning, 116024, - - 2014
Count data often arise in biomedical studies, while there could be a special feature with excessive zeros in the observed counts. The zero-inflated Poisson model provides a natural approach to accounting for the excessive zero counts. In the semiparametric framework, we propose a generalized partially linear single-index model for the ...
Cao Yang Y Department of Computer Science, Virginia Tech, Blacksburg, VA, 24061, USA, - - 2014
Turing patterns can be observed in reaction-diffusion systems where chemical species have different diffusion constants. In recent years, several studies investigated the effects of noise on Turing patterns and showed that the parameter regimes, for which stochastic Turing patterns are observed, can be larger than the parameter regimes predicted by ...
Mattle Michael Jon - - 2014
Sunlight inactivates waterborne viruses via direct (absorption of sunlight by the virus) and indirect processes (adsorption of sunlight by external chromophores, which subsequently generate reactive species) processes. While the mechanisms underlying these processes are understood, their relative importance remains unclear. This study establishes an experimental framework to determine the kinetic ...
Turner G G School of Sport and Service Management, University of Brighton, Eastbourne, UK. Physiology Department, English Institute of Sport, EIS Performance Centre, Loughborough University, Loughborough, - - 2014
A new Radiometer™ hemoximeter (ABL-80) has recently become available to measure carboxyhaemoglobin concentration for the optimized CO-rebreathing method (oCOR-method). Within the English Institute of Sport (EIS), hemoximeters are used in three different laboratories; therefore, precision and agreement of total haemoglobin mass (tHbmass) determination across sites is essential, and comparison to ...
Moreira Marcelo M Agroicone , Av. General Furtado do Nascimento, 740 cj. 8, São Paulo, SP Brazil - - 2014
This study evaluated the life cycle GHG emissions of a renewable jet fuel produced from sugar cane in Brazil under a consequential approach. The analysis included the direct and indirect emissions associated with sugar cane production and fuel processing, distribution, and use for a projected 2020 scenario. The CA-GREET model ...
Fortier Antoine A a Department of Kinesiology and Physical Education , McGill University , Montreal , Quebec , - - 2014
Ice hockey requires rapid transitions between skating trajectories to effectively navigate about the ice surface. Player performance relates in large part to effective change-of-direction manoeuvres, but little is known about how those skills are performed mechanically and the effect of equipment design on them. The purpose of this study was ...
Keadle Sarah Kozey - - 2014
Accelerometers objectively assess physical activity (PA) and are currently used in several large-scale epidemiological studies, but there is no consensus for processing the data. This study compared the impact of wear-time assessment methods and using either vertical (V)-axis or vector magnitude (VM) cut-points on accelerometer output. Participants (7,650 women, mean ...
Calderhead Ben B Department of Mathematics, Imperial College London, London SW7 2AZ, United Kingdom - - 2014
Markov chain Monte Carlo methods (MCMC) are essential tools for solving many modern-day statistical and computational problems; however, a major limitation is the inherently sequential nature of these algorithms. In this paper, we propose a natural generalization of the Metropolis-Hastings algorithm that allows for parallelizing a single chain using existing ...
Kremers Romy M W RM Synapse bv, Cardiovascular Research Institute Maastricht, Maastricht University, the - - 2014
Generation of thrombin in time is the combined effect of the processes of prothrombin conversion and thrombin inactivation. Measurement of prothrombin consumption used to provide valuable information on haemostatic disorders, but is no longer used, due to its elaborate nature. Because thrombin generation (TG) curves are easily obtained with modern ...
Moore Sarah A SA 1Department of Orthopaedics, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, CANADA; 2Centre for Hip Health and Mobility, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, CANADA; 3Department of Family Medicine, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia, CANADA; 4Child and Family Research Institute, BC Women's and Children's Hospital, Vancouver, British Columbia, CANADA; 5College of Kinesiology, University of Saskatchewan, Saskatoon, Saskatchewan, CANADA; 6Centre for Global Health and Human Development, Department of Sport, Exercise and Health Sciences, Loughborough University, Leicestershire, UNITED KINGDOM; 7Centre for Clinical Epidemiology and Evaluation, Vancouver Coastal Health Research Institute, Vancouver, British Columbia, CANADA; 8Department of Statistics, Faculty of Science, University of British Columbia, Vancouver, British Columbia, - - 2014
Assessing biological maturity in studies of children is challenging. Sex-specific regression equations developed using anthropometric measures are widely used to predict somatic maturity. However, prediction accuracy was not established in external samples. Thus, we aimed to evaluate the fit of these equations, assess for over-fitting (adjusting as necessary), and calibrate ...
Spratford Wayne W a Movement Science , Australian Institute of Sport , Canberra , - - 2014
Abstract The purpose of this study was to investigate the utility of peak outward acceleration (POA) measured from an inertial sensor worn at the wrist as an indicator of the critical end point of the bowling action - ball release, a critical element when assessing illegal actions. Twenty-one finger-spin and ...
IJzerman-Boon Pieta C PC Center for Mathematical Sciences - Europe, MSD, Oss, The - - 2014
This paper considers a statistical model for the detection mechanism of qualitative microbiological test methods with a parameter for the detection proportion (the probability to detect a single organism) and a parameter for the false positive rate. It is demonstrated that the detection proportion and the bacterial density cannot be ...
Gibson Troy J TJ a Department of Production and Population Health , Royal Veterinary College , Hatfield , United - - 2014
Captive bolt stunning is used for rendering livestock insensible at slaughter. The mechanical factors relating to performance of 6 penetrating captive bolt gun (CBG) models were examined. The Matador Super Sécurit 3000 and the .25 Cash Euro Stunner had the highest kinetic energy values (443 J and 412 J, respectively) ...
Ogungbenro Kayode K Centre for Applied Pharmacokinetic Research, Manchester Pharmacy School, The University of Manchester, Oxford Road, Manchester, M13 9PT, UK, - - 2014
Models have been developed to explain double-peaked plasma concentration-time profiles using mechanisms such as variable absorption and enterohepatic recirculation. Interruption of gastric emptying has also been shown to produce double-peaks, and this work proposes models for analysis of such data. In the presence of levodopa, gastric emptying is interrupted at ...
Cheng Mu-Hua MH Department of Nuclear Medicine, Third Affiliated Hospital of Sun Yat-sen University, GuangZhou, Guangdong, - - 2014
The estimation of the glomerular filtration rate (GFR) is essential for the renal function. However, all estimation methods for GFR have advantages and disadvantages. The aim of this study was to develop a new quantitative method for estimating GFR and evaluate its clinical value. The new GFR was estimated by ...
Morrison Devlin G DG Department of Surgery, University of Alberta, Edmonton, AB, T6G 2B7, - - 2014
To investigate the accuracy and reliability of the Cobb angle, the spinous process angle (SPA), and apical vertebral rotation (AVR) for measuring adolescent idiopathic scoliosis (AIS), and to evaluate the correlations between these measurements. A retrospective study of two sets of standing posteroanterior radiographs of patients with AIS was performed. ...
Heskes Tom - - 2014
BackgroundThe rank product method is a powerful statistical technique for identifying differentially expressed molecules in replicated experiments. A critical issue in molecule selection is accurate calculation of the p-value of the rank product statistic to adequately address multiple testing. Both exact calculation and permutation and gamma approximations have been proposed ...
Prüstel Thorsten T Laboratory of Systems Biology, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland 20892, - - 2014
We further develop the general theory of the area reactivity model that describes the diffusion-influenced reaction of an isolated receptor-ligand pair in terms of a generalized Feynman-Kac equation and that provides an alternative to the classical contact reactivity model. Analyzing both the irreversible and reversible reaction, we derive the equation ...
Almukainzi May M Faculty of Pharmacy & Pharmaceutical Science, 3-142K Katz Group Centre for Pharmacy & Health Research, University of Alberta, 11361 - 87 Ave., Edmonton, AB, T6G 2E1, - - 2014
Dissolution testing is a performance test for many dosage forms including tablets and capsules. The objective of this study was to evaluate if computer simulations can predict the in vitro dissolution of two model drugs for which different dissolution data were available. Published montelukast sodium and glyburide dissolution data was ...
Sargento Paulo P Escola de Psicologia e Ciências da Vida, Universidade Lusófona de Humanidades e Tecnologias and COPELABS, Campo Grande, 376, 1749-024, Lisboa, Portugal, - - 2014
The Epworth Sleepiness Scale (ESS) is a largely wide used scale for sleepiness assessment. Measurement properties are studied in a sample of Portuguese adults, using different statistical procedures. The sample consisted of 222 Portuguese adults (97 men and 125 women) with a mean age of 42 years old (SD = 12.5), 46 of ...
Rostellato R R Department of Comparative Biomedicine and Food Science, University of Padova, viale dell'Università 16, 35020 Legnaro (PD), - - 2014
The aims of this study were to estimate covariance components for BW at 270 d ( BW270: ), carcass and ham quality traits in heavy pigs using models accounting for social effects and to compare the ability of such models to fit the data relative to models ignoring social interactions. ...
Murata Hiroshi H Ophthalmology, University of Tokyo, Tokyo, - - 2014
Purpose To generate a Variational Bayes model to predict visual field (VF) progression in glaucoma patients. Method This retrospective study included VF series from 911 eyes of 547 glaucoma patients as test data, and VF series from 5049 eyes of 2858 glaucoma patients as training data. Using training data, Variational ...
Rodriguez Pedro - - 2014
Constrained independent component analysis (CICA) algorithms provide an effective way to introduce prior information into the complex- and real-valued ICA framework. The work in this area has focus on adding constraints to the objective function of algorithms that assume a unitary demixing matrix. The unitary condition is required in order ...
Ning Kefeng - - 2014
In the operational optimization and scheduling problems of actual industrial processes, such as iron and steel, and microelectronics, the operational indices and process parameters usually need to be predicted. However, for some input and output variables of these prediction models, there may exist a lot of uncertainties coming from themselves, ...
Suo Shiteng S Department of Radiology, Ren Ji Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, - - 2014
To compare three different curve-fitting methods for intravoxel incoherent motion (IVIM) analysis in breast cancer. Diffusion-weighted imaging was acquired in 30 patients with breast cancer using seven b-values (0-800 s/mm(2) ). Three curve-fitting methods were used for biexponential IVIM analysis: a. Direct estimation of D (diffusion coefficient), D* (pseudodiffusion coefficient) ...
Franc Jeffrey Michael JM 1Emergency Medicine,University of - - 2014
Introduction Surge capacity, or the ability to manage an extraordinary volume of patients, is fundamental for hospital management of mass-casualty incidents. However, quantification of surge capacity is difficult and no universal standard for its measurement has emerged, nor has a standardized statistical method been advocated. As mass-casualty incidents are rare, ...
Milovanovic Olivera - - 2014
Objectives: The aim of our study was to develop a population pharmacokinetic (PPK) model for 25-hydroxyvitamin D clearance in a healthy young adult population in Serbia. Methods: Study sample consisted of 70 healthy young students of the Faculty of Medical Science, University of Kragujevac, Serbia, with a mean age and ...
Márquez G C GC 1Department of Animal and Poultry Sciences,Virginia Tech,Blacksburg,VA - - 2014
Accounting for environmental heteroscedasticity and genetics by environment interaction (G×E) in genetic evaluation is important because animals may not perform predictably across environments. The objectives of this study were to evaluate the presence and consequences of heteroscedasticity and G×E on genetic evaluation. The population considered was crossbred lambs sired by ...
Austin Peter C PC Institute for Clinical Evaluative Sciences, Toronto, Canada Institute of Health Management, Policy and Evaluation, University of Toronto, Toronto, Canada Schulich Heart Research Program, Sunnybrook Research Institute, Toronto, Canada - - 2014
We conducted an extensive set of empirical analyses to examine the effect of the number of events per variable (EPV) on the relative performance of three different methods for assessing the predictive accuracy of a logistic regression model: apparent performance in the analysis sample, split-sample validation, and optimism correction using ...
Chen Hsiang-Chun HC Department of Biostatistics, The University of Texas MD Anderson Cancer Center, Houston, TX, - - 2014
The classic concordance correlation coefficient measures the agreement between two variables. In recent studies, concordance correlation coefficients have been generalized to deal with responses from a distribution from the exponential family using the univariate generalized linear mixed model. Multivariate data arise when responses on the same unit are measured repeatedly ...
Avni Eliran E Dept. of Evolutionary Biology, University of Haifa, Haifa 31905, Israel ,E-mail: - - 2014
Despite impressive technical and theoretical developments, reconstruction of phylogenetic trees for enormous quantities of molecular data is still a challenging task. A key tool in analyses of large data sets has been the construction of separate trees for subsets (e.g., quartets) of sequences, and subsequent combination of these subtrees into ...
Fackle-Fornius Ellinor E Department of Statistics, Stockholm University, Stockholm, - - 2014
This paper considers the maximin approach for designing clinical studies. A maximin efficient design maximizes the smallest efficiency when compared with a standard design, as the parameters vary in a specified subset of the parameter space. To specify this subset of parameters in a real situation, a four-step procedure using ...
Qu Yongming Y Department of Biometrics, Eli Lilly and Company, Indianapolis, IN, - - 2014
Generalized linear models are commonly used to analyze categorical data such as binary, count, and ordinal outcomes. Adjusting for important prognostic factors or baseline covariates in generalized linear models may improve the estimation efficiency. The model-based mean for a treatment group produced by most software packages estimates the response at ...
1 2 3 4 5 6 7 8 9 10 >