Spatial autocorrelation analysis of health care hotspots in Taiwan in 2006

<p>Abstract</p> <p>Background</p> <p>Spatial analytical techniques and models are often used in epidemiology to identify spatial anomalies (hotspots) in disease regions. These analytical approaches can be used to not only identify the location of such hotspots, but also their spatial patterns.</p> <p>Methods</p> <p>In this study, we utilize spatial autocorrelation methodologies, including Global Moran's I and Local Getis-Ord statistics, to describe and map spatial clusters, and areas in which these are situated, for the 20 leading causes of death in Taiwan. In addition, we use the fit to a logistic regression model to test the characteristics of similarity and dissimilarity by gender.</p> <p>Results</p> <p>Gender is compared in efforts to formulate the common spatial risk. The mean found by local spatial autocorrelation analysis is utilized to identify spatial cluster patterns. There is naturally great interest in discovering the relationship between the leading causes of death and well-documented spatial risk factors. For example, in Taiwan, we found the geographical distribution of clusters where there is a prevalence of tuberculosis to closely correspond to the location of aboriginal townships.</p> <p>Conclusions</p> <p>Cluster mapping helps to clarify issues such as the spatial aspects of both internal and external correlations for leading health care events. This is of great aid in assessing spatial risk factors, which in turn facilitates the planning of the most advantageous types of health care policies and implementation of effective health care services.</p

Change of support problemへの新たな空間統計モデルの開発

筑波大学 (University of Tsukuba)201

Modeling Precipitation, Acute Gastrointestinal Illness, and Environmental Factors in North Carolina, USA

Increasing intensity and frequency of extreme weather events due to climate change underscores the importance of understanding the influence of hydroclimatic variability on health. Meteorological drivers affect rates of acute gastrointestinal illness (AGI), but the association between precipitation and AGI, the sensitivity to modeling decisions, and the effects of sociodemographic and environmental risk factors are not well characterized. Furthermore, methodological differences may reduce inter-study comparability and can affect model estimates.In this dissertation, we reviewed the methodologies of recent time series AGI-weather studies, including outcome and exposure variables, data sources, spatiotemporal aggregation, and model specification. To investigate the sensitivity of the association between AGI and precipitation to exposure definitions and effect measure modification (EMM), we used AGI emergency department (ED) visit and weather data (2008-2015) from North Carolina (NC) to develop daily, ZIP code-level quasi-Poisson generalized linear models and distributed lag models. We compared multiple precipitation metrics: absolute (total precipitation), extreme (90th, 95th, and 99th percentiles with and without zero-precipitation days), and antecedent (cumulative wet-dry days; 8-week wet-dry periods). We assessed for potential EMM by physiographic region, the density of hogs in concentrated animal feeding operations (CAFOs), and percent of population on private drinking water wells.Depending on exposure definition, we observed an overall cumulative decrease of 1-18% in AGI ED rates following extreme precipitation events (over 0-7 days), with stronger effects associated with heavier rainfall, and a 2% (95% CI: 1.02, 1.03) increase after antecedent (8-week) wet periods. Inverse statewide results following extreme precipitation—dominated by the demographic weight of urban centers in the Piedmont region—were consistent with dilution effects posited by the concentration-dilution hypothesis but obscured dramatic sub-state variation. While EMM by private wells was inconclusive, region and hog density strongly modified the associations observed, with increased AGI ED rates following 95th percentile precipitation in the mountains (18%), coastal plains (19%), and areas exposed to hog CAFOs (7-15%). Our results reveal the vulnerability of mountainous, coastal, and CAFO-impacted areas in NC to rainfall-exacerbated AGI risk. This dissertation highlights the hazards of data aggregation and importance of precipitation exposure definitions and effect measure modification when modeling climate-health relationships.Doctor of Philosoph

Construction and application of a landscape dynamics assessment tool

Landscapes are shaped and influenced by a dynamic balance of ecological processes and anthropogenic activity. Substantial changes may disrupt the natural balance of ecosystems, jeopardizing their capacity to provide essential services for the population. Landscape changes, often measured via land cover variations, are pointed out as a major cause of biodiversity loss and, thus, a central topic in Conservation Biology. Some authors warned that key concepts like ‘habitat loss and fragmentation’ are often misused, causing misinterpretations and erroneous conclusions. The central aim of this work is to develop an analytical method of assessing landscape dynamics and a conceptual framework capable of clarifying the spatial patterns of land transformation. The conceptual framework, the associated terminology, and the method called Landscape Dynamic Typology, were developed based on the landscape composition and configuration variations. To complement and enhance the methodological approach, two tools were built: i) LDTtool, an ArcGIS toolbox and ii) LDT4QGIS, a group of scripts for QGIS. The tools’ multiple features and settings were demonstrated in illustrative examples and case studies as distinct as grasslands preservation in Slovenia, invasive plants removal in a mountainous Natura 2000 site, or the characterization of montado loss in Portugal. The use of these software by other authors in urban studies in places like Romania and Indonesia further attests to their usefulness and acceptance by the community. Both tools are freely available and can be adapted to fulfil analysts’ needs. New versions will be released whenever a relevant update or improvement is implemented. In specialized or in more comprehensive approaches, complementing or complemented by other software, Landscape Dynamic Typology has shown to be useful in analytical procedures involving land use or land cover changes. By allowing iterative simulations, assisting in change detection and in spatial pattern classification and visualization, it contributes to more informed decision-making; CONSTRUÇÃO E APLICAÇÃO DE UMA FERRAMENTA DE AVALIAÇÃO DE DINÂMICAS DE PAISAGENS RESUMO: As paisagens são moldadas por um equilíbrio dinâmico de processos ecológicos e actividade antropogénica. Alterações substanciais podem perturbar o equilíbrio natural dos ecossistemas, diminuindo a sua capacidade para fornecer serviços essenciais à população. As alterações paisagísticas, geralmente medidas através da variação da ocupação do solo, são uma das principais causas da perda de biodiversidade e um tópico central em biologia da conservação. Alguns autores alertaram que conceitos como ‘perda e fragmentação de habitats’ são frequentemente mal aplicados, originando interpretações e conclusões erradas. O objectivo central deste trabalho é desenvolver uma estrutura conceptual para clarificar os padrões espaciais de transformação e um construir um método de análise de dinâmicas paisagísticas. O enquadramento conceptual, a terminologia associada e o método, Tipologia de Dinâmicas de Paisagem, foram desenvolvidos com base na variação da composição do mosaico de ocupação do solo. Para complementar a abordagem metodológica foram construídas duas ferramentas: i) LDTtool, uma toolbox para ArcGIS; e ii) LDT4QGIS, um grupo de scripts para QGIS. As suas funcionalidades foram demonstradas em exemplos e casos de estudo tão díspares como a conservação de prados na Eslovénia, remoção de plantas invasoras num sítio da Rede Natura 2000 em ambiente montanhoso ou a caracterização da perda de áreas de montado em Portugal. O uso deste software por outros autores, nomeadamente em estudos urbanos na Roménia e na Indonésia, atesta a sua usabilidade e aceitação pela comunidade. As ferramentas estão disponíveis gratuitamente e podem ser adaptadas para fazer face às necessidades do analista. Serão lançadas novas versões quando novas funcionalidades forem desenvolvidas. Em abordagens especializadas ou generalistas, a Tipologia de Dinâmicas de Paisagem, mostrou ser útil para procedimentos analíticos envolvendo alterações de ocupação do solo. Auxiliando na detecção de alterações, classificação e visualização de padrões espaciais e permitindo fazer simulações, contribui para uma tomada de decisão informada

LIPIcs, Volume 277, GIScience 2023, Complete Volume

LIPIcs, Volume 277, GIScience 2023, Complete Volum

Accessibility to green space in the Melbourne metropolitan area.

Demand for green space by the public is becoming stronger for aesthetic enjoyment, recreation, clean air and quiet environment. Green space can protect biodiversity, absorb pollutants, adjust urban temperature and increase urban residents’ longevity. Accessibility to green spaces has been regarded as a useful measure of the quality of life in urban areas. Adequate and equitable accessibility to green space for all residents in urban areas is an important planning objective in many urban areas in the world, including the Melbourne Metropolitan Area (MMA), to sustain urban residents’ quality of life and well-being. The relative contributions of different kinds of facilities to the attractiveness of a green space have been weighted in relation to four population groups, determined from the 2011 ABS census data, including young (aged 0-15), adult (aged 16-64), aged (aged 65+), and total (aged 0-115). The accessibility values to neighbourhood green spaces for the four groups of population from each Mesh block (MB) across the MMA are measured with the following four different methods: M2SFCA_G, the 2-step floating catchment area modified by the Gaussion function; M2SFCA_B, the 2-step floating catchment area modified by the Butterworth filter; M3SFCA_G, the 3-step floating catchment area modified by the Gaussion function; and M3SFCA_B, the 3-step floating catchment area modified by the Butterworth filter.. According to MB level accessibility measured with the modified floating catchment area method, on average, the percentage of population with relatively high, Medium +, Medium, Medium -, and low accessibility to green space is about 21.2%, 18.5%, 25.6%, 18.7%, and 16.2%, These findings should provide valuable evidence for urban planners and public policy makers as well as the general public for formulating future urban plans. The methodology developed in this study should be applicable to other metropolitan areas within and even beyond Australia, should the required datasets are readily available and accessible. The thesis also includes some discussions about the relative merits of the four different floating catchment area based methods and some recommendations for future researches

Aedes aegypti Density and Risk of Dengue Virus Seroconversion

Routine entomological monitoring data are used as a surrogate for overall risk of dengue virus (DENV) infection and to trigger implementation of control interventions. Indicators that characterize Aedes aegypti abundance have not consistently been associated with an increased risk of dengue virus (DENV) seroconversion. Using longitudinal entomological and serological data from Iquitos, Peru, this dissertation estimated the risk of DENV infection for several entomological indicators to determine if any measure of Ae. aegypti abundance was associated with transmission. Entomological survey data from two longitudinal cohort studies linked with 8,153 paired serological observations were analyzed. Indicators of Ae. aegypti density were calculated from entomological. The risk ratios (RR) estimating the association between Ae. aegypti abundance at the household and block levels and the six-month risk of DENV seroconversion were obtained. Cross-sectional Ae. aegypti densities were not associated with an increased risk of DENV seroconversion. Longitudinal measures of adult stage density resulted in adjusted RRs ranging from 1.01 (95% CI: 1.01, 1.02) to 1.30 (95% CI: 1.17, 1.46) and categorical immature indices (RRs ranging from 1.21 (95% CI: 1.07, 1.37) to 1.75 (95% CI: 1.23, 2.5)). A total of 90,046 entomological monitoring observations were used to model the space/time covariance of ln(adult Ae. aegypti per m2). Mosquito density modeled using the Bayesian Maximum Entropy (BME) geostatistical framework was associated with an increased risk of DENV infection among densities ranging from 0.005 to 0.01 mosquitoes per m2 (adjusted risk ratio: 1.14; 95% CI: 1.01, 1.28). A multi-level logistic model was used to test for heterogeneity of the association between DENV risk and longitudinal measures of Ae. aegypti density. The multi-level model results suggest that the population-level risk ratios are more appropriate estimates of the Ae. aegypti-DENV seroconversion association. Ae. aegypti densities calculated from repeat entomological monitoring were associated with DENV seroconversion, whereas estimates of Ae. aegypti abundance measured cross-sectionally were not. It is possible that Ae. aegypti populations exhibit too much variability across space and time for periodic, cross-sectional measurement to adequately characterize entomological risk, in addition to having no correlation with true infection events due to human movement in space and time.Doctor of Philosoph

Applications of geospatial analysis techniques for public health

Indiana University-Purdue University Indianapolis (IUPUI)Geospatial analysis is a generic term describing several technologies or methods of computational analysis using the Earth as a living laboratory. These methods can be implemented to assess risk and study preventative mitigation practices for Public Health. Through the incorporation Geographic Information Science and Remote Sensing tools, data collection can be conducted at a larger scale, more frequent, and less expensive that traditional in situ methods. These techniques can be extrapolated to be used to study a variety of topics. Application of these tools and techniques were demonstrated through Public Health research. Although it is understand resolution, or scale, of a research project can impact a study’s results; further research is needed to understand the extent of the result’s bias. Extreme heat vulnerability analysis was studied to validate previously identified socioeconomic and environmental variables influential for mitigation studies, and how the variability of resolution impacts the results of the methodology. Heat was also investigated for the implication of spatial and temporal resolution, or aggregation, influence on results. Methods studying the physical and socioeconomic environments of Dengue Fever outbreaks were also studied to identify patters of vector emergence