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Fernández-Casal Rubén González-Manteiga Wenceslao Febrero-Bande Manuel 《Statistics and Computing》2003,13(2):127-136
In this paper we propose a generalization of the Shapiro and Botha (1991) approach that allows one to obtain flexible spatio-temporal stationary variogram models. It is shown that if the weighted least squares criterion is chosen, the fitting of such models to pilot estimations of the variogram can be easily carried out by solving a quadratic programming problem. The work also includes an application to real data and a simulation study in order to illustrate the performance of the proposed space-time dependency modeling. 相似文献
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This study explored how different ecological factors, within and outside the family, affected the educational success of the children of undocumented families. The sample consisted of 63 immigrant Latino parents (40 families) who resided in North Central Indiana. This study utilized an ethnographic research design. Findings demonstrated that immigration laws were affecting the educational success of the children of undocumented families. Most parents expressed lack of familiarity of the American educational system and that they had culture and language barriers. Findings also demonstrated that undocumented families were adapting to their realities, as a result of the resiliency in their families and communities. Implications for practice and future research were provided. 相似文献
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Anurans are excellent site-specific bioindicators. Although urbanization imposes diverse threats to wildlife species, little is known about its effect on tropical anurans. In this study we assessed the response of anurans to different conditions within an urban area (i.e. highly developed intra-urban residential areas, highly developed peri-urban residential areas, intra-urban abandoned lots, waterway). Our results show that: (1) 36 % of the regional anuran species pool was found within the boundaries of the studied city, (2) species richness peaked in highly developed peri-urban areas, (3) anuran abundance scores were highest in abandoned lots, and (4) highest similarity was found between the anuran community from highly developed peri-urban areas and abandoned lots. Although this study was carried out in a single city, and we only recorded four species, our results suggest that the urban semi-permeability process occurs for anuran communities, plus the fact that abandoned lots seem to offer better breeding habitat for anurans than a polluted waterway. 相似文献
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Horsford SR Parra-Cardona JR Schiamberg L Post LA 《Journal of elder abuse & neglect》2011,23(1):75-88
Despite the rapid growth of the elderly African American population in the U.S., elder abuse and neglect in African American families continue to be underdeveloped areas of study. This article presents an ecological and culturally informed framework for the study of elder abuse in African American populations. The model was developed based on Bronfenbrenner's Human Ecological Theory. The model identifies risk factors associated with different systems that have an influence on the lives of African American families. Cultural protective factors also are identified in the model. The model is intended to provide an understanding of elder abuse and neglect in African American families by considering the influence of contextual factors such as the legacy of slavery, social exclusion, and structural segregation and racism. Specific suggestions for practice are proposed according to cultural strengths of African American communities as well as the ecological premises of the model. 相似文献