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hierarchical generative model

Ming Wang, Stephen A Matthews, Khaled Iskandarani, Yimei Li, Zheng Li, Vernon M Chinchilli, Lijun Zhang
Prostate cancer is the most common cancer diagnosed among males, and the incidence in Pennsylvania, USA is considerably higher than nationally. Knowledge of regional differences and time trends in prostate cancer incidence may contribute to a better understanding of aetiologic factors and racial disparities in outcomes, and to improvements in preventive intervention and screening efforts. We used Pennsylvania Cancer Registry data on reported prostate cancer diagnoses between 2000 and 2011 to study the regional distribution and temporal trends of prostate cancer incidence in both Pennsylvania White males and Philadelphia metropolitan area Black males...
November 28, 2017: Geospatial Health
Xianfeng Lin, Jiaxin Chen, Pengcheng Qiu, Qi Zhang, Shengyu Wang, Mingzhen Su, Yunbin Chen, Keke Jin, An Qin, Shunwu Fan, Pengfei Chen, Xing Zhao
OBJECTIVE: To investigate the effect of decellularized osteochondral extracellular matrix (ECM) scaffold for osteochondral defect regeneration. DESIGN: We compared the histological features and microstructure of degenerated cartilage to normal articular cartilage. We also generated and evaluated osteochondral ECM scaffolds through decellularization technology. Then scaffolds were implanted to osteochondral defect in rabbit model. After 12 weeks surgery, regeneration tissues were analyzed by histology, immunohistochemistry evaluation...
December 9, 2017: Osteoarthritis and Cartilage
Jianyu Wang, Zhiwei Sun, Yongli Liu, Liangsheng Kong, Shixia Zhou, Junlin Tang, Hongmei Rosie Xing
Characterization of the stem-like properties of cancer stem cells (CSCs) remain indirect and qualitative, especially the ability of CSCs to undergo asymmetric cell division for self renewal and differentiation, a unique property of cells of stem origin. It is partly due to the lack of stable cellular models of CSCs. In this study, we developed a new approach for CSC isolation and purification to derive a CSC-enriched cell line (LLC-SE). By conducting five consecutive rounds of single cell cloning using the LLC-SE cell line, we obtained two distinct sub-population of cells within the Lewis lung cancer CSCs that employed largely symmetric division for self-renewal (LLC-SD) or underwent asymmetric division for differentiation (LLC-ASD)...
November 14, 2017: Oncotarget
Wiktor Młynarski, Josh H McDermott
Interaction with the world requires an organism to transform sensory signals into representations in which behaviorally meaningful properties of the environment are made explicit. These representations are derived through cascades of neuronal processing stages in which neurons at each stage recode the output of preceding stages. Explanations of sensory coding may thus involve understanding how low-level patterns are combined into more complex structures. To gain insight into such midlevel representations for sound, we designed a hierarchical generative model of natural sounds that learns combinations of spectrotemporal features from natural stimulus statistics...
December 8, 2017: Neural Computation
Jason H Moore, Maksim Shestov, Peter Schmitt, Randal S Olson
A central challenge of developing and evaluating artificial intelligence and machine learning methods for regression and classification is access to data that illuminates the strengths and weaknesses of different methods. Open data plays an important role in this process by making it easy for computational researchers to easily access real data for this purpose. Genomics has in some examples taken a leading role in the open data effort starting with DNA microarrays. While real data from experimental and observational studies is necessary for developing computational methods it is not sufficient...
2018: Pacific Symposium on Biocomputing
K M Rhodes, R M Turner, J Savović, H E Jones, D Mawdsley, J P T Higgins
OBJECTIVE: We investigated the associations between risk of bias judgments from Cochrane reviews for sequence generation, allocation concealment and blinding and between-trial heterogeneity. STUDY DESIGN AND SETTING: Bayesian hierarchical models were fitted to binary data from 117 meta-analyses, to estimate the ratio λ by which heterogeneity changes for trials at high/unclear risk of bias, compared to trials at low risk of bias. We estimated the proportion of between-trial heterogeneity in each meta-analysis that could be explained by the bias associated with specific design characteristics...
December 4, 2017: Journal of Clinical Epidemiology
Zhenyang Hui, Beiping Wu, Youjian Hu, Yao Yevenyo Ziggah
Obtaining high-precision filtering results from airborne lidar point clouds in complex environments has always been a hot topic. Mathematical morphology was widely used for filtering, owing to its simplicity and high efficiency. However, the morphology-based algorithms are deficient in preserving terrain details. In order to obtain a better filtering effect, this paper proposed an improved progressive morphological filter based on hierarchical radial basis function interpolation (PMHR) to refine the classical progressive morphological filter...
December 1, 2017: Applied Optics
Tianmin Shu, Yujia Peng, Lifeng Fan, Hongjing Lu, Song-Chun Zhu
People are adept at perceiving interactions from movements of simple shapes, but the underlying mechanism remains unknown. Previous studies have often used object movements defined by experimenters. The present study used aerial videos recorded by drones in a real-life environment to generate decontextualized motion stimuli. Motion trajectories of displayed elements were the only visual input. We measured human judgments of interactiveness between two moving elements and the dynamic change in such judgments over time...
December 7, 2017: Topics in Cognitive Science
Deirel Paz-Linares, Mayrim Vega-Hernández, Pedro A Rojas-López, Pedro A Valdés-Hernández, Eduardo Martínez-Montes, Pedro A Valdés-Sosa
The estimation of EEG generating sources constitutes an Inverse Problem (IP) in Neuroscience. This is an ill-posed problem due to the non-uniqueness of the solution and regularization or prior information is needed to undertake Electrophysiology Source Imaging. Structured Sparsity priors can be attained through combinations of (L1 norm-based) and (L2 norm-based) constraints such as the Elastic Net (ENET) and Elitist Lasso (ELASSO) models. The former model is used to find solutions with a small number of smooth nonzero patches, while the latter imposes different degrees of sparsity simultaneously along different dimensions of the spatio-temporal matrix solutions...
2017: Frontiers in Neuroscience
Emilia V Silletta, María B Franzoni, Gustavo A Monti, Rodolfo H Acosta
Two-dimension (2D) Nuclear Magnetic Resonance relaxometry experiments are a powerful tool extensively used to probe the interaction among different pore structures, mostly in inorganic systems. The analysis of the collected experimental data generally consists of a 2D numerical inversion of time-domain data where T2-T2 maps are generated. Through the years, different algorithms for the numerical inversion have been proposed. In this paper, two different algorithms for numerical inversion are tested and compared under different conditions of exchange dynamics; the method based on Butler-Reeds-Dawson (BRD) algorithm and the fast-iterative shrinkage-thresholding algorithm (FISTA) method...
November 30, 2017: Journal of Magnetic Resonance
Jongho Heo, Audrey N Beck, Shih-Fan Lin, Enrico Marcelli, Suzanne Lindsay, Brian Karl Finch
OBJECTIVES: No studies have focused on socioeconomic disparities in obesity within and between cohorts. Our objectives were to examine income gradients in obesity between birth-cohorts (inter-cohort variations) and within each birth-cohort (intra-cohort variations) by gender and race/ethnicity. METHODS: Our sample includes 56,820 white and black adults from pooled, cross-sectional National Health and Nutrition Examination Surveys (1971-2012). We fit a series of logistic hierarchical Age-Period-Cohort models to control for the effects of age and period, simultaneously...
November 27, 2017: American Journal of Human Biology: the Official Journal of the Human Biology Council
Femke Hoekstra, Marjolein A G van Offenbeek, Rienk Dekker, Florentina J Hettinga, Trynke Hoekstra, Lucas H V van der Woude, Cees P van der Schans
BACKGROUND: Although the importance of evaluating implementation fidelity is acknowledged, little is known about heterogeneity in fidelity over time. This study aims to generate insight into the heterogeneity in implementation fidelity trajectories of a health promotion program in multidisciplinary settings and the relationship with changes in patients' health behavior. METHODS: This study used longitudinal data from the nationwide implementation of an evidence-informed physical activity promotion program in Dutch rehabilitation care...
December 1, 2017: Implementation Science: IS
Laura N Medford-Davis, Rohan Shah, Danielle Kennedy, Emilie Becker
BACKGROUND: Preventable hospitalizations are markers of potentially low-value care. Addressing the problem requires understanding their contributing factors. OBJECTIVE: The objective of this study is to determine the correlation between specific mental health diseases and each potentially preventable hospitalization as defined by the Agency for Healthcare Research and Quality. DESIGN/SUBJECTS: The Texas Inpatient Public Use Data File, an administrative database of all Texas hospital admissions, identified 7,351,476 adult acute care hospitalizations between 2005 and 2008...
November 17, 2017: Medical Care
Yiping Wang, Fan Li, Tianshan Xue, Chao Liu, Donghai Yuan, Fei Qi, Bingbing Xu
Activation of peroxymonosulfate (PMS) by a novel hierarchical CuBi2O4 generated reactive oxygen radical for degradation refractory organic compounds in aqueous solution, which would be controlled by the morphology and surface chemistry of solid catalyst. It's found that the activation ability of CuBi2O4 toward PMS was highly dependent on the morphology and surface hydroxyl group, as using rhodamine B (RhB) as the model compound. The spherical CuBi2O4, which possessed higher density of surface hydroxyl group, exhibited better catalytic activity in RhB degradation than scattered cluster CuBi2O4, and as-prepared CuBi2O4 could efficiently activated PMS to degrade RhB within a wide pH range as an absolute heterogeneous process...
November 28, 2017: Environmental Science and Pollution Research International
Grace Edwards, Petra Vetter, Fiona McGruer, Lucy S Petro, Lars Muckli
Predictive coding theories propose that the brain creates internal models of the environment to predict upcoming sensory input. Hierarchical predictive coding models of vision postulate that higher visual areas generate predictions of sensory inputs and feed them back to early visual cortex. In V1, sensory inputs that do not match the predictions lead to amplified brain activation, but does this amplification process dynamically update to new retinotopic locations with eye-movements? We investigated the effect of eye-movements in predictive feedback using functional brain imaging and eye-tracking whilst presenting an apparent motion illusion...
November 28, 2017: Scientific Reports
Michael J Kinney, David Kacev, Suzanne Kohin, Tomoharu Eguchi
Horizontal behavior of highly migratory marine species is difficult to decipher because animals are wide-ranging, spend minimal time at the ocean surface, and utilize remote habitats. Satellite telemetry enables researchers to track individual movements, but population level inferences are rare due to data limitations that result from difficulty of capture and sporadic tag reporting. We introduce a Bayesian modeling framework to address population level questions with satellite telemetry data when data are sparse...
2017: PloS One
Kathryn Ogden, Jennifer Barr, David Greenfield
BACKGROUND: Recognition of a need for patient-centred care is not new, however making patient-centred care a reality remains a challenge to organisations. We need empirical studies to extend current understandings, create new representations of the complexity of patient-centred care, and guide collective action toward patient-centred health care. To achieve these ends, the research aim was to empirically determine what organisational actions are required for patient-centred care to be achieved...
November 28, 2017: BMC Health Services Research
Janis Klaise, Samuel Johnson
Food webs have been found to exhibit remarkable "motif profiles", patterns in the relative prevalences of all possible three-species subgraphs, and this has been related to ecosystem properties such as stability and robustness. Analysing 46 food webs of various kinds, we find that most food webs fall into one of two distinct motif families. The separation between the families is well predicted by a global measure of hierarchical order in directed networks-trophic coherence. We find that trophic coherence is also a good predictor for the extent of omnivory, defined as the tendency of species to feed on multiple trophic levels...
November 23, 2017: Scientific Reports
Nima Haghighi, Xiaoyue Cathy Liu, Guohui Zhang, Richard J Porter
This study examines the impact of a wide range of roadway geometric features on the severity outcomes of crashes occurred on rural two-lane highways. We argue that crash data have a hierarchical structure which needs to be addressed in modeling procedure. Moreover, most of previous studies ignored the impact of geometric features on crash types when developing crash severity models. We hypothesis that geometric features are more likely to determine crash type, and crash type together with other occupant, environmental and vehicle characteristics determine crash severity outcome...
November 20, 2017: Accident; Analysis and Prevention
Yuan Zhou, Karl J Friston, Peter Zeidman, Jie Chen, Shu Li, Adeel Razi
An important characteristic of spontaneous brain activity is the anticorrelation between the core default network (cDN) and the dorsal attention network (DAN) and the salience network (SN). This anticorrelation may constitute a key aspect of functional anatomy and is implicated in several brain disorders. We used dynamic causal modeling to assess the hypothesis that a causal hierarchy underlies this anticorrelation structure, using resting-state fMRI of healthy adolescent and young adults (N = 404). Our analysis revealed an asymmetric effective connectivity, such that the regions in the SN and DAN exerted an inhibitory influence on the cDN regions; whereas the cDN exerted an excitatory influence on the SN and DAN regions...
November 17, 2017: Cerebral Cortex
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