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https://www.readbyqxmd.com/read/28431361/uncertainty-quantification-and-validation-of-3d-lattice-scaffolds-for-computer-aided-biomedical-applications
#1
Recep M Gorguluarslan, Seung-Kyum Choi, Christopher J Saldana
A methodology is proposed for uncertainty quantification and validation to accurately predict the mechanical response of lattice structures used in the design of scaffolds. Effective structural properties of the scaffolds are characterized using a developed multi-level stochastic upscaling process that propagates the quantified uncertainties at strut level to the lattice structure level. To obtain realistic simulation models for the stochastic upscaling process and minimize the experimental cost, high-resolution finite element models of individual struts were reconstructed from the micro-CT scan images of lattice structures which are fabricated by selective laser melting...
April 12, 2017: Journal of the Mechanical Behavior of Biomedical Materials
https://www.readbyqxmd.com/read/28429965/bayesian-sem-for-specification-search-problems-in-testing-factorial-invariance
#2
Dexin Shi, Hairong Song, Xiaolan Liao, Robert Terry, Lori A Snyder
Specification search problems refer to two important but under-addressed issues in testing for factorial invariance: how to select proper reference indicators and how to locate specific non-invariant parameters. In this study, we propose a two-step procedure to solve these issues. Step 1 is to identify a proper reference indicator using the Bayesian structural equation modeling approach. An item is selected if it is associated with the highest likelihood to be invariant across groups. Step 2 is to locate specific non-invariant parameters, given that a proper reference indicator has already been selected in Step 1...
April 21, 2017: Multivariate Behavioral Research
https://www.readbyqxmd.com/read/28429842/linking-macroecology-and-community-ecology-refining-predictions-of-species-distributions-using-biotic-interaction-networks
#3
Phillip P A Staniczenko, Prabu Sivasubramaniam, K Blake Suttle, Richard G Pearson
Macroecological models for predicting species distributions usually only include abiotic environmental conditions as explanatory variables, despite knowledge from community ecology that all species are linked to other species through biotic interactions. This disconnect is largely due to the different spatial scales considered by the two sub-disciplines: macroecologists study patterns at large extents and coarse resolutions, while community ecologists focus on small extents and fine resolutions. A general framework for including biotic interactions in macroecological models would help bridge this divide, as it would allow for rigorous testing of the role that biotic interactions play in determining species ranges...
April 21, 2017: Ecology Letters
https://www.readbyqxmd.com/read/28429470/meta-analysis-combining-parallel-and-cross-over-trials-with-random-effects
#4
François Curtin
Meta-analysis can necessitate the combination of parallel and cross-over trial designs. Because of the differences in the trial designs and potential biases notably associated with the crossover trials, one often combines trials of the same designs only, which decreases the power of the meta-analysis. To combine results of clinical trials from parallel and cross-over designs, we extend the method proposed in an accompanying study to account for random effects. We propose here a hierarchical mixed model allowing the combination of the 2 types of trial designs and accounting for additional covariates where random effects can be introduced to account for heterogeneity in trial, treatment effect, and interactions...
April 21, 2017: Research Synthesis Methods
https://www.readbyqxmd.com/read/28429157/scenes-as-micro-cultures-examining-heterogeneity-of-hiv-risk-behavior-among-gay-bisexual-and-other-men-who-have-sex-with-men-in-toronto-canada
#5
Syed W Noor, Barry D Adam, David J Brennan, David A Moskowitz, Sandra Gardner, Trevor A Hart
Using latent class analysis (LCA), we examined patterns of participation in multiple scenes, how sexual risk practices vary by scene, and psychosocial factors associated with these patterns among 470 gay, bisexual, and other men who have sex with men (GBM) recruited from Toronto. We calculated posterior probability of being in a class from participation in nine separate scenes. We used Entropy, the Bayesian information criterion and the Lo-Mendel-Rubin likelihood ratio test to identify the best fit model. Fit indices suggested a four-class solution...
April 20, 2017: Archives of Sexual Behavior
https://www.readbyqxmd.com/read/28428869/rapid-maximum-likelihood-ancestral-state-reconstruction-of-continuous-characters-a-rerooting-free-algorithm
#6
Eric W Goolsby
Ancestral state reconstruction is a method used to study the evolutionary trajectories of quantitative characters on phylogenies. Although efficient methods for univariate ancestral state reconstruction under a Brownian motion model have been described for at least 25 years, to date no generalization has been described to allow more complex evolutionary models, such as multivariate trait evolution, non-Brownian models, missing data, and within-species variation. Furthermore, even for simple univariate Brownian motion models, most phylogenetic comparative R packages compute ancestral states via inefficient tree rerooting and full tree traversals at each tree node, making ancestral state reconstruction extremely time-consuming for large phylogenies...
April 2017: Ecology and Evolution
https://www.readbyqxmd.com/read/28428322/glycemic-control-during-continuous-subcutaneous-insulin-infusion-versus-multiple-daily-insulin-injections-in-type-2-diabetes-individual-patient-data-meta-analysis-and-meta-regression-of-randomized-controlled-trials
#7
REVIEW
John C Pickup, Yves Reznik, Alex J Sutton
OBJECTIVE: To compare glycemic control during continuous subcutaneous insulin infusion (CSII) and multiple daily insulin injections (MDI) in people with type 2 diabetes to identify patient characteristics that determine those best treated by CSII. RESEARCH DESIGN AND METHODS: Randomized controlled trials were selected comparing HbA1c during CSII versus MDI in people with type 2 diabetes. Data sources included Cochrane database and Ovid Medline. We explored patient-level determinants of final HbA1c level and insulin dose using Bayesian meta-regression models of individual patient data and summary effects using two-step meta-analysis...
May 2017: Diabetes Care
https://www.readbyqxmd.com/read/28427363/a-spatio-temporal-analysis-of-suicide-in-el-salvador
#8
Carlos Carcach
BACKGROUND: In 2012, international statistics showed El Salvador's suicide rate as 40th in the world and the highest in Latin America. Over the last 15 years, national statistics show the suicide death rate declining as opposed to an increasing rate of homicide. Though completed suicide is an important social and health issue, little is known about its prevalence, incidence, etiology and spatio-temporal behavior. The primary objective of this study was to examine completed suicide and homicide using the stream analogy to lethal violence within a spatio-temporal framework...
April 20, 2017: BMC Public Health
https://www.readbyqxmd.com/read/28427355/identifying-and-characterizing-hepatitis-c-virus-hotspots-in-massachusetts-a-spatial-epidemiological-approach
#9
Thomas J Stopka, Michael A Goulart, David J Meyers, Marga Hutcheson, Kerri Barton, Shauna Onofrey, Daniel Church, Ashley Donahue, Kenneth K H Chui
BACKGROUND: Hepatitis C virus (HCV) infections have increased during the past decade but little is known about geographic clustering patterns. METHODS: We used a unique analytical approach, combining geographic information systems (GIS), spatial epidemiology, and statistical modeling to identify and characterize HCV hotspots, statistically significant clusters of census tracts with elevated HCV counts and rates. We compiled sociodemographic and HCV surveillance data (n = 99,780 cases) for Massachusetts census tracts (n = 1464) from 2002 to 2013...
April 20, 2017: BMC Infectious Diseases
https://www.readbyqxmd.com/read/28427337/treatment-seeking-behaviour-in-low-and-middle-income-countries-estimated-using-a-bayesian-model
#10
Victor A Alegana, Jim Wright, Carla Pezzulo, Andrew J Tatem, Peter M Atkinson
BACKGROUND: Seeking treatment in formal healthcare for uncomplicated infections is vital to combating disease in low- and middle-income countries (LMICs). Healthcare treatment-seeking behaviour varies within and between communities and is modified by socio-economic, demographic, and physical factors. As a result, it remains a challenge to quantify healthcare treatment-seeking behaviour using a metric that is comparable across communities. Here, we present an application for transforming individual categorical responses (actions related to fever) to a continuous probabilistic estimate of fever treatment for one country in Sub-Saharan Africa (SSA)...
April 20, 2017: BMC Medical Research Methodology
https://www.readbyqxmd.com/read/28426818/alternative-glacial-interglacial-refugia-demographic-hypotheses-tested-on-cephalocereus-columna-trajani-cactaceae-in-the-intertropical-mexican-drylands
#11
Amelia Cornejo-Romero, Carlos Fabián Vargas-Mendoza, Gustavo F Aguilar-Martínez, Javier Medina-Sánchez, Beatriz Rendón-Aguilar, Pedro Luis Valverde, Jose Alejandro Zavala-Hurtado, Alejandra Serrato, Sombra Rivas-Arancibia, Marco Aurelio Pérez-Hernández, Gerardo López-Ortega, Cecilia Jiménez-Sierra
Historic demography changes of plant species adapted to New World arid environments could be consistent with either the Glacial Refugium Hypothesis (GRH), which posits that populations contracted to refuges during the cold-dry glacial and expanded in warm-humid interglacial periods, or with the Interglacial Refugium Hypothesis (IRH), which suggests that populations contracted during interglacials and expanded in glacial times. These contrasting hypotheses are developed in the present study for the giant columnar cactus Cephalocereus columna-trajani in the intertropical Mexican drylands where the effects of Late Quaternary climatic changes on phylogeography of cacti remain largely unknown...
2017: PloS One
https://www.readbyqxmd.com/read/28425926/chemical-source-localization-fusing-concentration-information-in-the-presence-of-chemical-background-noise
#12
Víctor Pomareda, Rudys Magrans, Juan M Jiménez-Soto, Dani Martínez, Marcel Tresánchez, Javier Burgués, Jordi Palacín, Santiago Marco
We present the estimation of a likelihood map for the location of the source of a chemical plume dispersed under atmospheric turbulence under uniform wind conditions. The main contribution of this work is to extend previous proposals based on Bayesian inference with binary detections to the use of concentration information while at the same time being robust against the presence of background chemical noise. For that, the algorithm builds a background model with robust statistics measurements to assess the posterior probability that a given chemical concentration reading comes from the background or from a source emitting at a distance with a specific release rate...
April 20, 2017: Sensors
https://www.readbyqxmd.com/read/28424892/bayesian-characterization-of-uncertainty-in-species-interaction-strengths
#13
Christopher Wolf, Mark Novak, Alix I Gitelman
Considerable effort has been devoted to the estimation of species interaction strengths. This effort has focused primarily on statistical significance testing and obtaining point estimates of parameters that contribute to interaction strength magnitudes, leaving the characterization of uncertainty associated with those estimates unconsidered. We consider a means of characterizing the uncertainty of a generalist predator's interaction strengths by formulating an observational method for estimating a predator's prey-specific per capita attack rates as a Bayesian statistical model...
April 19, 2017: Oecologia
https://www.readbyqxmd.com/read/28424482/logistic-bayesian-lasso-for-genetic-association-analysis-of-data-from-complex-sampling-designs
#14
Yuan Zhang, Jonathan N Hofmann, Mark P Purdue, Shili Lin, Swati Biswas
Detecting gene-environment interactions with rare variants is critical in dissecting the etiology of common diseases. Interactions with rare haplotype variants (rHTVs) are of particular interest. At the same time, complex sampling designs, such as stratified random sampling, are becoming increasingly popular for designing case-control studies, especially for recruiting controls. The US Kidney Cancer Study (KCS) is an example, wherein all available cases were included while the controls at each site were randomly selected from the population by frequency matching with cases based on age, sex and race...
April 20, 2017: Journal of Human Genetics
https://www.readbyqxmd.com/read/28423913/application-of-iata-a-case-study-in-evaluating-the-global-and-local-performance-of-a-bayesian-network-model-for-skin-sensitization
#15
J M Fitzpatrick, G Patlewicz
The information characterizing key events in an Adverse Outcome Pathway (AOP) can be generated from in silico, in chemico, in vitro and in vivo approaches. Integration of this information and interpretation for decision making are known as integrated approaches to testing and assessment (IATA). One such IATA was published by Jaworska et al., which describes a Bayesian network model known as ITS-2. The current work evaluated the performance of ITS-2 using a stratified cross-validation approach. We also characterized the impact of replacing the most significant component of the network, output from the expert system TIMES-SS, with structural alert information from the OECD Toolbox and Toxtree...
April 20, 2017: SAR and QSAR in Environmental Research
https://www.readbyqxmd.com/read/28423058/accurate-phenotyping-reconciling-approaches-through-bayesian-model-averaging
#16
Carla Chia-Ming Chen, Jonathan Macgregor Keith, Kerrie Lee Mengersen
Genetic research into complex diseases is frequently hindered by a lack of clear biomarkers for phenotype ascertainment. Phenotypes for such diseases are often identified on the basis of clinically defined criteria; however such criteria may not be suitable for understanding the genetic composition of the diseases. Various statistical approaches have been proposed for phenotype definition; however our previous studies have shown that differences in phenotypes estimated using different approaches have substantial impact on subsequent analyses...
2017: PloS One
https://www.readbyqxmd.com/read/28423011/the-range-of-the-mange-spatiotemporal-patterns-of-sarcoptic-mange-in-red-foxes-vulpes-vulpes-as-revealed-by-camera-trapping
#17
David Carricondo-Sanchez, Morten Odden, John D C Linnell, John Odden
Sarcoptic mange is a widely distributed disease that affects numerous mammalian species. We used camera traps to investigate the apparent prevalence and spatiotemporal dynamics of sarcoptic mange in a red fox population in southeastern Norway. We monitored red foxes for five years using 305 camera traps distributed across an 18000 km2 area. A total of 6581 fox events were examined to visually identify mange compatible lesions. We investigated factors associated with the occurrence of mange by using logistic models within a Bayesian framework, whereas the spatiotemporal dynamics of the disease were analysed with space-time scan statistics...
2017: PloS One
https://www.readbyqxmd.com/read/28422991/mortality-is-associated-with-inflammation-anemia-specific-diseases-and-treatments-and-molecular-markers
#18
Mark Moeller, Christiane Pink, Nicole Endlich, Karlhans Endlich, Hans-Jörgen Grabe, Henry Völzke, Marcus Dörr, Matthias Nauck, Markus M Lerch, Rüdiger Köhling, Birte Holtfreter, Thomas Kocher, Georg Fuellen
Lifespan is a complex trait, and longitudinal data for humans are naturally scarce. We report the results of Cox regression and Pearson correlation analyses using data of the Study of Health in Pomerania (SHIP), with mortality data of 1518 participants (113 of which died), over a time span of more than 10 years. We found that in the Cox regression model based on the Bayesian information criterion, apart from chronological age of the participant, six baseline variables were considerably associated with higher mortality rates: smoking, mean attachment loss (i...
2017: PloS One
https://www.readbyqxmd.com/read/28422990/sensory-cortical-response-to-uncertainty-and-low-salience-during-recognition-of-affective-cues-in-musical-intervals
#19
Fernando Bravo, Ian Cross, Emmanuel Andreas Stamatakis, Martin Rohrmeier
Previous neuroimaging studies have shown an increased sensory cortical response (i.e., heightened weight on sensory evidence) under higher levels of predictive uncertainty. The signal enhancement theory proposes that attention improves the quality of the stimulus representation, and therefore reduces uncertainty by increasing the gain of the sensory signal. The present study employed functional magnetic resonance imaging (fMRI) to investigate the neural correlates for ambiguous valence inferences signaled by auditory information within an emotion recognition paradigm...
2017: PloS One
https://www.readbyqxmd.com/read/28422650/joint-magnetic-calibration-and-localization-based-on-expectation-maximization-for-tongue-tracking
#20
Jun Lu, Zhongtao Yang, Klaus Okkelberg, Maysam Ghovanloo
BACKGROUND: Tongue tracking, which helps researchers gain valuable insights into speech mechanism, has many applications in speech therapy and language learning. The wireless localization technique, which involves tracking a small magnetic tracer within the 3-D oral space, provides a low cost and convenient approach to capture tongue kinematics. In practice, this technique requires accurate calibration of 3-axial magnetic sensors used in the tracking system. The data-driven calibration depends on the trajectories of magnetic tracer and the ambient noise, which may change across time and space...
April 12, 2017: IEEE Transactions on Bio-medical Engineering
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