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https://www.readbyqxmd.com/read/28213206/selected-aspects-of-prior-and-likelihood-information-for-a-bayesian-classifier-in-a-road-safety-analysis
#1
Marzena Nowakowska
The development of the Bayesian logistic regression model classifying the road accident severity is discussed. The already exploited informative priors (method of moments, maximum likelihood estimation, and two-stage Bayesian updating), along with the original idea of a Boot prior proposal, are investigated when no expert opinion has been available. In addition, two possible approaches to updating the priors, in the form of unbalanced and balanced training data sets, are presented. The obtained logistic Bayesian models are assessed on the basis of a deviance information criterion (DIC), highest probability density (HPD) intervals, and coefficients of variation estimated for the model parameters...
February 14, 2017: Accident; Analysis and Prevention
https://www.readbyqxmd.com/read/28212281/energy-based-acoustic-source-localization-methods-a-survey
#2
Wei Meng, Wendong Xiao
Energy-based source localization is an important problem in wireless sensor networks (WSNs), which has been studied actively in the literature. Numerous localization algorithms, e.g., maximum likelihood estimation (MLE) and nonlinear-least-squares (NLS) methods, have been reported. In the literature, there are relevant review papers for localization in WSNs, e.g., for distance-based localization. However, not much work related to energy-based source localization is covered in the existing review papers. Energy-based methods are proposed and specially designed for a WSN due to its limited sensor capabilities...
February 15, 2017: Sensors
https://www.readbyqxmd.com/read/28212131/psychometric-properties-of-a-new-instrument-for-assessing-irrational-thoughts-in-burn-victims-scale-of-irrational-thoughts-after-burn-injuries
#3
Zahra Zare, Homayoun Sadeghi-Bazargani, Fatemeh Ranjbar, Diana Stark Ekman, Mostafa Farahbakhsh, Hemmat Maghsoudi, Robert Ekman, Farideh Nasiri
The objective of this study was to develop and evaluate a scale for assessing irrational thoughts among burned patients. The present study was mixed (qualitative-methodologic) which was performed in several stages such as investigating similar or related scales, interviewing with patients and psychologists. Content validity was calculated by modified KAPPA basis on relevance and clarity. The reliability of the scale was measured using internal consistency and the test-retest method. To determine the construct validity, exploratory factor analysis approach using maximum likelihood extraction with varimax rotation was conducted...
February 9, 2017: Journal of Burn Care & Research: Official Publication of the American Burn Association
https://www.readbyqxmd.com/read/28211951/semiparametric-regression-analysis-of-interval-censored-competing-risks-data
#4
Lu Mao, Dan-Yu Lin, Donglin Zeng
Interval-censored competing risks data arise when each study subject may experience an event or failure from one of several causes and the failure time is not observed directly but rather is known to lie in an interval between two examinations. We formulate the effects of possibly time-varying (external) covariates on the cumulative incidence or sub-distribution function of competing risks (i.e., the marginal probability of failure from a specific cause) through a broad class of semiparametric regression models that captures both proportional and non-proportional hazards structures for the sub-distribution...
February 17, 2017: Biometrics
https://www.readbyqxmd.com/read/28211087/semiparametric-pseudoscore-for-regression-with-multidimensional-but-incompletely-observed-regressor
#5
Zonghui Hu, Jing Qin, Dean Follmann
We study the regression fβ (Y|X,Z), where Y is the response, Z∈Rd is a vector of fully observed regressors and X is the regressor with incomplete observation. To handle missing data, maximum likelihood estimation via expectation-maximisation (EM) is the most efficient but is sensitive to the specification of the distribution of X. Under a missing at random assumption, we propose an EM-type estimation via a semiparametric pseudoscore. Like in EM, we derive the conditional expectation of the score function given Y and Z, or the mean score, over the incompletely observed units under a postulated distribution of X...
February 16, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28211076/comparison-of-conditional-bias-adjusted-estimators-for-interim-analysis-in-clinical-trials-with-survival-data
#6
Masashi Shimura, Masahiko Gosho, Akihiro Hirakawa
Group sequential designs are widely used in clinical trials to determine whether a trial should be terminated early. In such trials, maximum likelihood estimates are often used to describe the difference in efficacy between the experimental and reference treatments; however, these are well known for displaying conditional and unconditional biases. Established bias-adjusted estimators include the conditional mean-adjusted estimator (CMAE), conditional median unbiased estimator, conditional uniformly minimum variance unbiased estimator (CUMVUE), and weighted estimator...
February 17, 2017: Statistics in Medicine
https://www.readbyqxmd.com/read/28209119/plastome-phylogeny-and-early-diversification-of-brassicaceae
#7
Xinyi Guo, Jianquan Liu, Guoqian Hao, Lei Zhang, Kangshan Mao, Xiaojuan Wang, Dan Zhang, Tao Ma, Quanjun Hu, Ihsan A Al-Shehbaz, Marcus A Koch
BACKGROUND: The family Brassicaceae encompasses diverse species, many of which have high scientific and economic importance. Early diversifications and phylogenetic relationships between major lineages or clades remain unclear. Here we re-investigate Brassicaceae phylogeny with complete plastomes from 51 species representing all four lineages or 5 of 6 major clades (A, B, C, E and F) as identified in earlier studies. RESULTS: Bayesian and maximum likelihood phylogenetic analyses using a partitioned supermatrix of 77 protein coding genes resulted in nearly identical tree topologies exemplified by highly supported relationships between clades...
February 16, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28208832/mitigating-multipath-bias-using-a-dual-polarization-antenna-theoretical-performance-algorithm-design-and-simulation
#8
Lin Xie, Xiaowei Cui, Sihao Zhao, Mingquan Lu
It is well known that multipath effect remains a dominant error source that affects the positioning accuracy of Global Navigation Satellite System (GNSS) receivers. Significant efforts have been made by researchers and receiver manufacturers to mitigate multipath error in the past decades. Recently, a multipath mitigation technique using dual-polarization antennas has become a research hotspot for it provides another degree of freedom to distinguish the line-of-sight (LOS) signal from the LOS and multipath composite signal without extensively increasing the complexity of the receiver...
February 13, 2017: Sensors
https://www.readbyqxmd.com/read/28208652/a-new-distribution-family-for-microarray-data
#9
Diana Mabel Kelmansky, Lila Ricci
The traditional approach with microarray data has been to apply transformations that approximately normalize them, with the drawback of losing the original scale. The alternative stand point taken here is to search for models that fit the data, characterized by the presence of negative values, preserving their scale; one advantage of this strategy is that it facilitates a direct interpretation of the results. A new family of distributions named gpower-normal indexed by p∈R is introduced and it is proven that these variables become normal or truncated normal when a suitable gpower transformation is applied...
February 10, 2017: Microarrays
https://www.readbyqxmd.com/read/28203352/a-glossy-simultaneous-contrast-conjoint-measurements-of-gloss-and-lightness
#10
Sabrina Hansmann-Roth, Pascal Mamassian
Interactions between the albedo and the gloss on a surface are commonplace. Darker surfaces are perceived glossier (contrast gloss) than lighter surfaces and darker backgrounds can enhance perceived lightness of surfaces. We used maximum likelihood conjoint measurements to simultaneously quantify the strength of those effects. We quantified the extent to which albedo can influence perceived gloss and physical gloss can influence perceived lightness. We modeled the contribution of lightness and gloss and found that increasing lightness reduced perceived gloss by about 32% whereas gloss had a much weaker influence on perceived lightness of about 12%...
January 2017: I-Perception
https://www.readbyqxmd.com/read/28202088/what-influences-the-home-range-size-of-free-roaming-domestic-dogs
#11
S Dürr, N K Dhand, C Bombara, S Molloy, M P Ward
In many regions of the world domestic dogs are free roaming and live in close relationship with humans. These free-roaming domestic dogs (FRDD) can cause public health problems such as dog bites and transmission of infectious diseases. To effectively control diseases transmitted by FRDD, knowledge on the dogs' behaviour is required. To identify predictors of home range (HR) size, we collected global positioning system data from 135 FRDD living in eight Aboriginal and Torres Strait Islander communities in Northern Australia...
February 16, 2017: Epidemiology and Infection
https://www.readbyqxmd.com/read/28198889/single-lane-180%C3%A2-%C3%A2-gb-s-db-pam-4-signal-transmission-over-an-80%C3%A2-%C3%A2-km-dcf-free-ssmf-link
#12
Qiang Zhang, Nebojsa Stojanovic, Jinlong Wei, Changsong Xie
We experimentally demonstrate the generation and successful transmission of a single-lane 180 Gb/s (90 GBd) duo-binary four-level pulse-amplitude modulation (DB-PAM-4) signal over an 80 km standard single-mode fiber with a net data-rate of 150 Gb/s, enabled by a dual-drive Mach-Zehnder modulator-aided dispersion pre-compensation. A net data rate of 168 Gb/s is also achievable, for ranges up to 40 km. To mitigate bandwidth limitations and error spreading, pre-coded DB-PAM-4 is used; the pre-coding provides a gain of approximately 1 dB...
February 15, 2017: Optics Letters
https://www.readbyqxmd.com/read/28195664/an-adaptive-model-for-rapid-and-direct-estimation-of-extravascular-extracellular-space-in-dynamic-contrast-enhanced-mri-studies
#13
Azimeh N V Dehkordi, Alireza Kamali-Asl, James R Ewing, Ning Wen, Indrin J Chetty, Hassan Bagher-Ebadian
Extravascular extracellular space (ve ) is a key parameter to characterize the tissue of cerebral tumors. This study introduces an artificial neural network (ANN) as a fast, direct, and accurate estimator of ve from a time trace of the longitudinal relaxation rate, ΔR1 (R1  = 1/T1 ), in DCE-MRI studies. Using the extended Tofts equation, a set of ΔR1 profiles was simulated in the presence of eight different signal to noise ratios. A set of gain- and noise-insensitive features was generated from the simulated ΔR1 profiles and used as the ANN training set...
February 14, 2017: NMR in Biomedicine
https://www.readbyqxmd.com/read/28193727/inference-of-gene-flow-in-the-process-of-speciation-an-efficient-maximum-likelihood-method-for-the-isolation-with-initial-migration-model
#14
Rui J Costa, Hilde Wilkinson-Herbots
The isolation-with-migration (IM) model is commonly used to make inferences about gene flow during speciation, using polymorphism data. However, Becquet and Przeworski (2009) report that the parameter estimates obtained by fitting the IM model are very sensitive to the model's assumptions, including the assumption of constant gene flow until the present. This paper is concerned with the isolation-with-initial-migration (IIM) model, which drops precisely this assumption. In the IIM model, one ancestral population divides into two descendant subpopulations, between which there is an initial period of gene flow and a subsequent period of isolation...
February 13, 2017: Genetics
https://www.readbyqxmd.com/read/28193153/molecular-evolution-of-globin-genes-in-gymnotiform-electric-fishes-relation-to-hypoxia-tolerance
#15
Ran Tian, Mauricio Losilla, Ying Lu, Guang Yang, Harold Zakon
BACKGROUND: Nocturnally active gymnotiform weakly electric fish generate electric signals for communication and navigation, which can be energetically taxing. These fish mainly inhabit the Amazon basin, where some species prefer well-oxygenated waters and others live in oxygen-poor, stagnant habitats. The latter species show morphological, physiological, and behavioral adaptations for hypoxia-tolerance. However, there have been no studies of hypoxia tolerance on the molecular level. Globins are classic respiratory proteins...
February 13, 2017: BMC Evolutionary Biology
https://www.readbyqxmd.com/read/28192280/iterative-reconstruction-of-sipm-light-response-functions-in-a-square-shaped-compact-gamma-camera
#16
Andrey Morozov, Francisco Alves, Joao Marcos, Raimundo Martins, Luis Pereira, Vladimir Solovov, Vitaly Chepel
Compact gamma cameras with a square-shaped monolithic scintillator crystal and an array of silicon photomultipliers (SiPMs) are actively being developed for applications in areas such as small animal imaging, cancer diagnostics and radiotracer guided surgery. Statistical methods of position reconstruction, which are potentially superior to the traditional centroid method, require accurate knowledge of the spatial response of each photomultiplier. Using both Monte Carlo simulations and experimental data obtained with a camera prototype, we show that the spatial response of all photomultipliers (light response functions) can be parameterized with axially symmetric functions obtained iteratively from flood field irradiation data...
February 13, 2017: Physics in Medicine and Biology
https://www.readbyqxmd.com/read/28188878/towards-a-higher-level-ensifera-phylogeny-inferred-from-mitogenome-sequences
#17
Zhijun Zhou, Ling Zhao, Nian Liu, Huifang Guo, Bei Guan, Juanxia Di, Fuming Shi
Although mitogenomes are useful tools for inferring evolutionary history, only a few representative ones can be used for most Ensifera lineages. Thirty-two ensiferan mitogenomes were determined using ABI Sanger sequencing and standard primer walking of 2-3 overlapping Long-PCR fragments, or Illumina® HiSeq2000 for "shotgun" sequenced long-PCR-amplified mitochondrial or total genomic DNA. Six patterns of gene arrangements, including the novel trnR-trnS(AGN)-trnA-trnN-trnG-nad3 in Lipotactes tripyrga (Lipotactinae), were identified from 59 ensiferan mitogenomes...
February 8, 2017: Molecular Phylogenetics and Evolution
https://www.readbyqxmd.com/read/28187633/integrative-taxonomy-reveals-the-first-record-and-a-new-species-for-the-previously-monotypic-genus-i-tethytimea-i-tethyida-tethyidae-in-the-gulf-of-mexico
#18
José Antonio Cruz-Barraza, Cristina Vega, Enrique Ávila, Laura Elena Vázquez-Maldonado
The first record of the previous monotypic genus Tethytimea and the description of a new species from cryptic habitats of Gulf of Mexico are presented. Tethytimea carmelita sp. nov., is a red orange cushion shaped sponge (about 5 mm thick) with a tuberculate to granular surface. The spicular complement is formed by tylostyles (200-1120 µm length), smooth spheres (12.5-55 µm in diameter); megasters-spheroxyasters (12.5-90 µm in diameter); and micrasters in two categories: oxy-strongylasters (12.5-27.5 µm in diameter) and spherotylasters (2...
January 25, 2017: Zootaxa
https://www.readbyqxmd.com/read/28187423/integrated-automatic-workflow-for-phylogenetic-tree-analysis-using-public-access-and-local-web-services
#19
Kasikrit Damkliang, Pichaya Tandayya, Unitsa Sangket, Ekawat Pasomsub
At the present, coding sequence (CDS) has been discovered and larger CDS is being revealed frequently. Approaches and related tools have also been developed and upgraded concurrently, especially for phylogenetic tree analysis. This paper proposes an integrated automatic Taverna workflow for the phylogenetic tree inferring analysis using public access web services at European Bioinformatics Institute (EMBL-EBI) and Swiss Institute of Bioinformatics (SIB), and our own deployed local web services. The workflow input is a set of CDS in the Fasta format...
November 28, 2016: Journal of Integrative Bioinformatics
https://www.readbyqxmd.com/read/28187237/zero-inflated-spatio-temporal-models-for-disease-mapping
#20
Mahmoud Torabi
In this paper, our aim is to analyze geographical and temporal variability of disease incidence when spatio-temporal count data have excess zeros. To that end, we consider random effects in zero-inflated Poisson models to investigate geographical and temporal patterns of disease incidence. Spatio-temporal models that employ conditionally autoregressive smoothing across the spatial dimension and B-spline smoothing over the temporal dimension are proposed. The analysis of these complex models is computationally difficult from the frequentist perspective...
February 10, 2017: Biometrical Journal. Biometrische Zeitschrift
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