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Neighborhood AND spatial modeling

Ahmed Soliman, Fahmi Khalifa, Ahmed Elnakib, Mohamed Abou El-Ghar, Neal Dunlap, Brian Wang, Georgy Gimel'farb, Robert Keynton, Ayman El-Baz
To accurately segment pathological and healthy lungs for reliable computer-aided disease diagnostics, a stack of chest CT scans is modeled as a sample of a spatially inhomogeneous joint 3D Markov-Gibbs random field (MGRF) of voxel-wise lung and chest CT image signals (intensities). The proposed learnable MGRF integrates two visual appearance sub models with an adaptive lung shape submodel. The first-order appearance submodel accounts for both the original CT image and its Gaussian scale space (GSS) filtered version to specify local and global signal properties, respectively...
September 12, 2016: IEEE Transactions on Medical Imaging
A M E Noreen, M A Niissalo, S K Y Lum, E L Webb
As deforestation and urbanization continue at rapid rates in tropical regions, urban forest patches are essential repositories of biodiversity. However, almost nothing is known about gene flow of forest-dependent tree species in urban landscapes. In this study, we investigated gene flow in the insect-pollinated, wind-dispersed tropical tree Koompassia malaccensis in and among three remnant forest patches in the urbanized landscape of Singapore. We genotyped the vast majority of adults (N=179) and a large number of recruits (N=2103) with 8 highly polymorphic microsatellite markers...
October 5, 2016: Heredity
Jana A Hirsch, Joe Grengs, Amy Schulz, Sara D Adar, Daniel A Rodriguez, Shannon J Brines, Ana V Diez Roux
Investments in neighborhood built environments could increase physical activity and overall health. Disproportionate distribution of these changes in advantaged neighborhoods could inflate health disparities. Little information exists on where changes are occurring. This paper aims to 1) identify changes in the built environment in neighborhoods and 2) investigate associations between high levels of change and sociodemographic characteristics. Using Geographic Information Systems, neighborhood land-use, local destinations (for walking, social engagement, and physical activity), and sociodemographics were characterized in 2000 and 2010 for seven U...
September 23, 2016: Social Science & Medicine
Wang Cong, Jianhua Song, Kuan Luan, Hong Liang, Lei Wang, Xingcheng Ma, Jin Li
Because of the poor radio frequency coil uniformity and gradient-driven eddy currents, there is much noise and intensity inhomogeneity (bias) in brain magnetic resonance (MR) image, and it severely affects the segmentation accuracy. Better segmentation results are difficult to achieve by traditional methods; therefore, in this paper, a modified brain MR image segmentation and bias field estimation model based on local and global information is proposed. We first construct local constraints including image neighborhood information in Gaussian kernel mapping space, and then the complete regularization is established by introducing nonlocal spatial information of MR image...
2016: Computational and Mathematical Methods in Medicine
Hoehun Ha, Peter A Rogerson, James R Olson, Daikwon Han, Ling Bian, Wanyun Shao
Heavy industrialization has resulted in the contamination of soil by metals from anthropogenic sources in Anniston, Alabama. This situation calls for increased public awareness of the soil contamination issue and better knowledge of the main factors contributing to the potential sources contaminating residential soil. The purpose of this spatial epidemiology research is to describe the effects of physical factors on the concentration of lead (Pb) in soil in Anniston AL, and to determine the socioeconomic and demographic characteristics of those residing in areas with higher soil contamination...
2016: International Journal of Environmental Research and Public Health
Honghong Yang, Shiru Qu
Object tracking based on sparse representation has given promising tracking results in recent years. However, the trackers under the framework of sparse representation always overemphasize the sparse representation and ignore the correlation of visual information. In addition, the sparse coding methods only encode the local region independently and ignore the spatial neighborhood information of the image. In this paper, we propose a robust tracking algorithm. Firstly, multiple complementary features are used to describe the object appearance; the appearance model of the tracked target is modeled by instantaneous and stable appearance features simultaneously...
2016: Computational Intelligence and Neuroscience
Amy A Mericle, Katherine J Karriker-Jaffe, Shalika Gupta, David M Sheridan, Doug L Polcin
Sober living houses (SLHs) are alcohol and drug-free living environments for individuals in recovery. The goal of this study was to map the distribution of SLHs in Los Angeles (LA) County, California (N = 260) and examine neighborhood correlates of SLH density. Locations of SLHs were geocoded and linked to tract-level Census data as well as to publicly available information on alcohol outlets and recovery resources. Neighborhoods with SLHs differed from neighborhoods without them on measures of socioeconomic disadvantage and accessibility of recovery resources...
September 2016: American Journal of Community Psychology
Eric Delmelle, Michael Hagenlocher, Stefan Kienberger, Irene Casas
Dengue fever has gradually re-emerged across the global South, particularly affecting urban areas of the tropics and sub-tropics. The dynamics of dengue fever transmission are sensitive to changes in environmental conditions, as well as local demographic and socioeconomic factors. In 2010, the municipality of Cali, Colombia, experienced one of its worst outbreaks, however the outbreak was not spatially homogeneous across the city. In this paper, we evaluate the role of socioeconomic and environmental factors associated with this outbreak at the neighborhood level, using a Geographically Weighted Regression model...
September 9, 2016: Acta Tropica
Candice A Myers, Kara D Denstel, Stephanie T Broyles
Multilevel health research often focuses on a singular dimension of the neighborhood environment in relation to individual-level health behaviors (e.g., diet, physical activity) and outcomes (e.g., obesity). This study examined associations between healthy and unhealthy neighborhood features across food, physical activity, and social environments. We used neighborhood-level (i.e., census block group) access (0/1) measures of the 1) food (grocery store, convenience store, fast food restaurant), 2) physical activity (fitness/recreation facility, park), and 3) social (crime, renter occupancy) environments to capture both healthy and unhealthy neighborhood features for a sample of neighborhoods (n=126) in East Baton Rouge Parish, Louisiana, United States...
September 6, 2016: Preventive Medicine
Matteo Detto, Helene C Muller-Landau
Spatial interactions are widely acknowledged to play a significant role in sustaining diversity in ecological communities. However, theoretical work on this topic has focused on how spatial processes affect coexistence of species that differ in their strategies, with less attention to how spatial processes matter when competitors are equivalent. Furthermore, though it is recognized that models with local dispersal and local competition may sustain higher diversities of equivalent competitors than models in which these are not both localized, there is debate as to whether this reflects merely equalizing effects or whether there is also a stabilizing component...
September 5, 2016: Theoretical Population Biology
Jun-Hyun Kim, Donghwan Gu, Wonmin Sohn, Sung-Ho Kil, Hwanyong Kim, Dong-Kun Lee
Rapid urbanization has accelerated land use and land cover changes, and generated the urban heat island effect (UHI). Previous studies have reported positive effects of neighborhood landscapes on mitigating urban surface temperatures. However, the influence of neighborhood landscape spatial patterns on enhancing cooling effects has not yet been fully investigated. The main objective of this study was to assess the relationships between neighborhood landscape spatial patterns and land surface temperatures (LST) by using multi-regression models considering spatial autocorrelation issues...
2016: International Journal of Environmental Research and Public Health
Laura Tach, Sara Jacoby, Douglas J Wiebe, Terry Guerra, Therese S Richmond
The ACHIEVEability model of affordable housing aims to promote self-sufficiency by requiring enrollment in postsecondary education in exchange for subsidized housing. In this study, we exploit the quasi random assignment of ACHIEVEability participants (N = 84) to subsidized housing units to evaluate whether microneighborhood environments moderated participants' progress in postsecondary education. Participants progressed in their educational pursuits in line with program requirements, earning about 12 college credits per year...
2016: Housing Policy Debate
Chawarat Rotejanaprasert, Andrew Lawson, Susan Bolick-Aldrich, Deborah Hurley
There has been little development of surveillance procedures for epidemiological data with fine spatial resolution such as case events at residential address locations. This is often due to difficulties of access when confidentiality of medical records is an issue. However, when such data are available, it is important to be able to affect an appropriate analysis strategy. We propose a model for point events in the context of prospective surveillance based on conditional logistic modeling. A weighted conditional autoregressive model is developed for irregular lattices to account for distance effects, and a Dirichlet tessellation is adopted to define the neighborhood structure...
August 2016: Statistical Methods in Medical Research
Iyad Kheirbek, Jay Haney, Sharon Douglas, Kazuhiko Ito, Thomas Matte
BACKGROUND: On-road vehicles are an important source of fine particulate matter (PM2.5) in cities, but spatially varying traffic emissions and vulnerable populations make it difficult to assess impacts to inform policy and the public. METHODS: We estimated PM2.5-attributable mortality and morbidity from on-road vehicle generated air pollution in the New York City (NYC) region using high-spatial-resolution emissions estimates, air quality modeling, and local health incidence data to evaluate variations in impacts by vehicle class, neighborhood, and area socioeconomic status...
2016: Environmental Health: a Global Access Science Source
Xuejing Li, Lin Wang, Zhixin Liu, Daoyi Dong
This paper considers the consensus behavior of a spatially distributed 3-D dynamical network composed of heterogeneous agents: leaders and followers, in which the leaders have the preferred information about the destination, while the followers do not have. All followers move in a 3-D Euclidean space with a given speed and with their headings updated according to the average velocity of the corresponding neighbors. Compared with the 2-D model, a key point lies in how to analyze the dynamical behavior of a "linear" nonhomogeneous equation where the nonhomogeneous term strongly nonlinearly depends on the states of all agents...
August 18, 2016: IEEE Transactions on Neural Networks and Learning Systems
Susanne A Kraemer, Sébastien Wielgoss, Francesca Fiegna, Gregory J Velicer
The spatial distribution of potential interactants is critical to social evolution in all cooperative organisms. Yet the biogeography of microbial kin discrimination at the scales most relevant to social interactions is poorly understood. Here we resolve the microbiogeography of social identity and genetic relatedness in local populations of the model cooperative bacterium Myxococcus xanthus at small spatial scales, across which the potential for dispersal is high. Using two criteria of relatedness-colony-merger compatibility during cooperative motility and DNA-sequence similarity at highly polymorphic loci-we find that relatedness decreases greatly with spatial distance even across the smallest scale transition...
October 2016: Molecular Ecology
Nathan C Lo, Jean T Coulibaly, Eran Bendavid, Eliézer K N'Goran, Jürg Utzinger, Jennifer Keiser, Isaac I Bogoch, Jason R Andrews
BACKGROUND: A key epidemiologic feature of schistosomiasis is its focal distribution, which has important implications for the spatial targeting of preventive chemotherapy programs. We evaluated the diagnostic accuracy of a urine pooling strategy using a point-of-care circulating cathodic antigen (POC-CCA) cassette test for detection of Schistosoma mansoni, and employed simulation modeling to test the classification accuracy and efficiency of this strategy in determining where preventive chemotherapy is needed in low-endemicity settings...
August 2016: PLoS Neglected Tropical Diseases
Weeberb J Requia, Henrique L Roig, Matthew D Adams, Antonella Zanobetti, Petros Koutrakis
Neighborhood characteristics affect an individual's quality of life. Although several studies have examined the relationship between neighborhood environments and human health, we are unaware of studies that have examined the distance-decay of this effect and then presented the risk results spatially. Our study is unique in that is explores the health effects in a less developed country compared to most studies that have focused on developed countries. The objective of our study is to quantify the distance-decay cardiorespiratory diseases risk related to 28 neighborhood aspects in the Federal District, Brazil and present this information spatially through risk maps of the region...
August 3, 2016: Environmental Research
Tony H Grubesic, Ran Wei, Alan T Murray, William Alex Pridemore
BACKGROUND: A growing body of research recommends controlling alcohol availability to reduce harm. Various common approaches, however, provide dramatically different pictures of the physical availability of alcohol. This limits our understanding of the distribution of alcohol access, the causes and consequences of this distribution, and how best to reduce harm. The aim of this study is to introduce both a gravity potential measure of access to alcohol outlets, comparing its strengths and weaknesses to other popular approaches, and an empirically-derived taxonomy of neighborhoods based on the type of alcohol access they exhibit...
2016: Population Health Metrics
Simon Willi, Anselm Grundhofer
Galvanoscopic scanning laser projectors are powerful vector graphic devices offering a tremendous local brightness advantage compared to standard video projection systems. However, such devices have inherent problems, such as temporal flicker and spatially inaccurate rendering. We propose a method to generate an accurate point-based projection with such devices. To overcome the mentioned problems, we present a camera-based method to automatically analyze the laser projector's motion behavior. With this information, a model database is generated that is used to optimize the scanning path of projected point sequences...
November 2016: IEEE Transactions on Visualization and Computer Graphics
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