[Show abstract][Hide abstract] ABSTRACT: This paper reports a study examining the association between colorectal cancer (CRC) survival and access to healthcare in Texas using data from the Texas cancer registry. We geo-referenced the data to the census tract level and used an enhanced 2-step floating catchment area method and factor analysis to estimate people's spatial and non-spatial access to healthcare. In addition, Cox proportional hazard regression was employed to assess the influence of different factors on CRC survival, and a spatial scan statistic was used to investigate the geographic disparity of CRC survival and the influence of access to healthcare. The analyses revealed that Hispanics, non-Hispanic blacks, and residents from several regions in Texas were more likely to die from CRC than others. Disadvantaged population groups based on factors rather than spatial access had an increased risk of CRC-specific mortality. Spatial access to oncologists has a significant association with CRC survival in non-urban areas but not in urban areas. Geographic disparities of CRC survival were largely influenced by factors rather than spatial access to healthcare.
Health & Place 11/2011; 18(2):321-9. · 2.42 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The purpose of this article is to describe a capstone course in undergraduate student geographical research in which GIS and other geospatial tools were used to teach undergraduate students basic geographical principles. The course uses the “cooperative learning” pedagogical approach to address one of a number of client-supplied research projects, chosen on the basis of logistical difficulty, time, student ability, and project importance. In the connection of primary data with existing data, students confronted a number of important research issues such as mapping ethics, database design and management, time management, group dynamics, and research limitations.
[Show abstract][Hide abstract] ABSTRACT: Chagas disease is endemic and is recognized as a major health problem in many Latin American countries. Despite the parallels between socio-economic and environmental conditions in Texas and much of Latin America, Chagas disease is not a notifiable human disease in Texas. Based on extensive review of related literature, this paper seeks to recognize the evidence that Chagas Disease is endemic to Texas but the epidemiological, parasitological and entomological patterns of Chagas disease in Texas are both different from and parallel to other endemic regions. We find that with a growing immigrant human reservoir, the epidemiological differences may be reduced and result in increasing incidence of the disease. Chagas disease should be recognized as an emerging disease among both immigrant and indigenous populations. Without proper actions, Chagas disease will place increasing burden on the health care system. Current medical treatments consist of chemotherapies that carry the risk of serious side effects; curing the potentially fatal disease remains equivocal. Therefore, as shown in South America, prevention is paramount and can be successfully achieved through intervention and education. We conclude that biogeographical research is needed to (1) distinguish the dynamic evolution of the agent-vector-host system, (2) document locations with greater risk and identify mechanisms responsible for observed changes in risk, and (3) assist in developing a model for Triatomid vector-borne disease in states like Texas where the disease is both endemic and may be carried by a sizeable immigrant population. Tracking of Chagas disease and planning for appropriate health care services would also be aided by including Chagas disease on the list of reportable diseases for humans.
Social Science [?] Medicine 08/2007; 65(1):60-79. · 2.73 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Many social and economic activities, especially those in urban areas, are subject to location restrictions imposed by existing street networks. To analyze the spatial patterns of these urban activities, the restrictions imposed by the street networks need to be taken into account. K-function is a method commonly used for general point pattern analysis as well as crime pattern study. However, applying the planar K-function to analyze the spatial autocorrelation patterns of urban activities that are typically distributed along streets could result in false alarm problems. Depending on the nature of the urban street networks and the distribution of the urban activities, either positive or negative false alarm might be introduced. Acknowledging that many urban crimes are typically distributed along streets, this paper compares the traditional planar K-function with a network K-function for crime pattern analysis. The patterns of vehicle thefts in San Antonio, Texas are examined as a case study.
[Show abstract][Hide abstract] ABSTRACT: Abstract Multi-scale effects of spatial autocorrelation may be present in datasets. Given the importance of detecting local non-stationarity in many theoretical as well as applied studies, it is necessary to “remove” the impact of large-scale autocorrelation before common techniques for local pattern analysis are applied. It is proposed in this paper to employ the regionalized range to define spatially varying sub-regions within which the impact of large-scale autocorrelation is minimized and the local patterns can be investigated. A case study is conducted on crime data to detect crime hot spots and cold spots in San Antonio, Texas. The results confirm the necessity of treating the non-stationarity of large-scale spatial autocorrelation prior to any action aiming at detecting local autocorrelation.
Transactions in GIS 01/2006; 10:301-318. · 0.54 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: A series of exploratory analyses of auto thefts in the city of Buffalo are reported and discussed in this paper. With the aid of Geographic Information Systems (GIS) and Exploratory Spatial Data Analysis (ESDA), the spatial clustering of auto thefts in Buffalo is evaluated, the distribution of auto thefts along the streets is examined, and the spatial choice of auto thefts as related to the patterns of socioeconomic activities in the study area is investigated. In addition to the patterns of auto theft hot spots, this study also examines the impact that the distribution of the available vehicles has on auto theft locations. Analyses reveal that locations along the major roads and the roads directly connected to the major roads are at high risk of being targeted by auto thieves. Furthermore, it is concluded that certain types of urban socioeconomic activities are more attractive to the potential auto thieves than others.
[Show abstract][Hide abstract] ABSTRACT: While we have seen the wide use of other information technologies in health services and management, the use of geographic information technologies in health related services has been limited so far. Given that location-related data play important roles in many health related services, it is anticipated that geographic information technologies have a lot to offer in helping improve health related services, management, and research. As an example, the authors report the development of a geographic information system (GIS) for Texas-Mexico border disease surveillance and environmental health research. This presentation covers three important aspects in the development of the GIS: (1) the specification of uses and users of the GIS and the associated data, products, and functions; (2) a preliminary design of the data types and formats in the GIS; and (3) a prototype of a GIS-based spatial search tool that can be used to support environmental epidemiology research. In some disease monitoring and environmental epidemiology studies, it is often necessary to perform spatial search to determine the distances between environmental hazardous sites and the locations of cases and controls when distance is used as measure of exposure. The GIS can be used to interactively and automatically determine the distance between any possible pair of environmental hazardous sites and cases/controls. Preliminary results suggest that the prototype GIS is indeed a powerful tool for spatial search when distance is used as a measure of exposure in environmental health research. The reported system should be useful to researchers facing similar situations in disease monitoring and environmental health research.
Services Systems and Services Management, 2005. Proceedings of ICSSSM '05. 2005 International Conference on; 07/2005