31 research outputs found

    Climate and habitat configuration limit range expansion and patterns of dispersal in a non-native lizard

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    Invasive species are one of the main causes of biodiversity loss worldwide. As introduced, populations increase in abundance and geographical range, so does the potential for negative impacts on native communities. As such, there is a need to better understand the processes driving range expansion as species become established in recipient landscapes. Through an investigation into capacity for population growth and range expansion of introduced populations of a nonā€native lizard (Podarcis muralis), we aimed to demonstrate how multiā€scale factors influence spatial spread, population growth, and invasion potential in introduced species. We collated location records of P. muralis presence in England, UK through data collected from field surveys and a citizen science campaign. We used these data as input for presenceā€background models to predict areas of climate suitability at a nationalā€scale (5 km resolution), and fineā€scale habitat suitability at the local scale (2 m resolution). We then integrated local models into an individualā€based modeling platform to simulate population dynamics and forecast range expansion for 10 populations in heterogeneous landscapes. Nationalā€scale models indicated climate suitability has restricted the species to the southern parts of the UK, primarily by a latitudinal cline in overwintering conditions. Patterns of population growth and range expansion were related to differences in local landscape configuration and heterogeneity. Growth curves suggest populations could be in the early stages of exponential growth. However, annual rates of range expansion are predicted to be low (5ā€“16 m). We conclude that extensive nationwide range expansion through secondary introduction is likely to be restricted by currently unsuitable climate beyond southern regions of the UK. However, exponential growth of local populations in habitats providing transport pathways is likely to increase opportunities for regional expansion. The broad habitat niche of P. muralis, coupled with configuration of habitat patches in the landscape, allows populations to increase locally with minimal dispersal

    Racial and Ethnic Disparities in Cancer Screening: The Importance of Foreign Birth as a Barrier to Care

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    CONTEXT: Racial/ethnic groups comprised largely of foreign-born individuals have lower rates of cancer screening than white Americans. Little is known about whether these disparities are related primarily to their race/ethnicity or birthplace. OBJECTIVE: To determine whether foreign birthplace explains some racial/ethnic disparities in cancer screening. DESIGN, SETTING, AND SUBJECTS: Cross-sectional study using 1998 data from the National Health Interview Survey. MAIN OUTCOME MEASURES: Completion of cervical, breast, or colorectal cancer screening. RESULTS: Of respondents, 15% were foreign born. In analyses adjusted for sociodemographic characteristics and illness burden, black respondents were as or more likely to report cancer screening than white respondents; however, Hispanic and Asian-American and Pacific Islander (AAPI) respondents were significantly less likely to report screening for most cancers. When race/ethnicity and birthplace were considered together, U.S.-born Hispanic and AAPI respondents were as likely to report cancer screening as U.S.-born whites; however, foreign-born white (adjusted odds ratio [AOR], 0.58; 95% confidence interval [CI], 0.41 to 0.82), Hispanic (AOR, 0.65; 95% CI, 0.53 to 0.79), and AAPI respondents (AOR, 0.28; 95% CI, 0.19 to 0.39) were less likely than U.S.-born whites to report Pap smears. Foreign-born Hispanic and AAPI respondents were also less likely to report fecal occult blood testing (FOBT); AORs, 0.72; 95% CI, 0.53 to 0.98; and 0.61; 95% CI, 0.39 to 0.96, respectively); and sigmoidoscopy (AORs, 0.70; 95% CI, 0.51 to 0.97; and 0.63; 95% CI, 0.40 to 0.99, respectively). Furthermore, foreign-born AAPI respondents were less likely to report mammography (AOR, 0.49; 95% CI, 0.28 to 0.86). Adjusting for access to care partially attenuated disparities among foreign-born respondents. CONCLUSION: Foreign birthplace may explain some disparities previously attributed to race or ethnicity, and is an important barrier to cancer screening, even after adjustment for other factors. Increasing access to health care may improve disparities among foreign-born persons to some degree, but further study is needed to understand other barriers to screening among the foreign-born
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