1,682 research outputs found

    Health care utilization among immigrants and native-born populations in 11 European countries. Results from the Survey of Health, Ageing and Retirement in Europe

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    Objective: This study examines health care utilization of immigrants relative to the native-born populations aged 50 years and older in eleven European countries. Methods. We analyzed data from the Survey of Health Aging and Retirement in Europe (SHARE) from 2004 for a sample of 27,444 individuals in 11 European countries. Negative Binomial regression was conducted to examine the difference in number of doctor visits, visits to General Practitioners (GPs), and hospital stays between immigrants and the native-born individuals. Results: We find evidence those immigrants above age 50 use health services on average more than the native-born populations with the same characteristics. Our models show immigrants have between 6% and 27% more expected visits to the doctor, GP or hospital stays when compared to native-born populations in a number of European countries. Discussion: Elderly immigrant populations might be using health services more intensively due to cultural reasons.count data, physician services, immigration.

    Applying the USA National Phenology Network\u27s Growing Degree Day Maps in Making Management Decisions

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    The USA National Phenology Network generates daily growing degree day maps for the United States at fine spatial resolution (2.5–3.0 km) using a January 1 start date and two common base temperatures. Maps are available up to 6 days into the future and can be viewed and manipulated using an online visualization tool or downloaded as image or raster files. By exploring these maps through the visualization tool, it is possible to see how heat accumulation over the course of the year varies from average conditions and to anticipate when heat accumulation thresholds will be met

    Book Reviews

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    Book Review

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    Ecology of a central Appalachian white-tailed deer herd at low density

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    White-tailed deer (Odocoileus virginianus) are the most abundant big game species in North America and serve as the dominant herbivore in the majority of the Appalachian region. Despite the abundance of research conducted on this species, relatively little is known of the ecology of white-tailed deer occurring at low densities. Our study population experienced a 75% decline in population density and a three-fold increase in habitat disturbance via timber harvests between 2002 and 2005. From May 2006 to April 2008 I examined the home-range, survival, and herbivory patterns of a central Appalachian white-tailed deer herd that has recently experienced both a substantial decline in population density and now occurs at extremely low densities (1--3/km 2). Home-range and core-area size did not differ among age classes in any season. Annual home-range size of yearlings (505 ha) was larger than for adults (313 ha), although core-area size did not differ. Within age classes there were no seasonal differences in home-range or core-area size. Home-range site-fidelity did not differ among age classes for any season or among seasons for any age class. Core-area site fidelity was higher in fall (74%) than in summer (45%) or winter (36%) when pooled across age classes but did not differ among age classes. Survival was lower during the fall (0.89) than during summer (0.99) or winter (0.94). Human-induced mortalities (n = 12) constituted 67% of all observed mortalities during the study; all mortalities were in the adult age class. Woody browse abundance differed among plot types, with clearcut interior (50.16 twigs/plot) plots having more browse than clearcut edge (31.95 twigs/plot) or mature forest (18.93 twigs/plot) plots. Browsing rates of woody plants was higher in clearcut edge plots (5.55%) than in clearcut interior (3.99%) or mature forest plots (3.32%). Observed home-range and core-area sizes were substantially larger than previously reported for the same population prior to declines in density. This supports previous work that suggests home-range size is inversely related to population density and positively correlated with habitat disturbance. Survival rates were similar to previously reported, suggesting that adult survival is robust to changes in population density. Previously reported browsing rates were approximately 5 times the levels reported herein, however such a decrease would be expected with reduced population density and an increase in browse abundance, both of which occurred on the study site

    A Letter of Alexander H. Stephens

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    Understanding the dynamics of species distributions under climate change: linking empirical evidence, ecological theory, and statistical models

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    Climate change is threatening biota all over the world through dictating changes in species distributions. The ability to predict the effects of climate on species distributions requires an understanding of how climatic and disturbance factors relate to species distributions. I examined the relationship between climate, disturbance, and geographic distributions of vascular plants in the western United States. Within the mountain ranges of California, woody plants have largely shifted their distributions downhill during the 20th century. These shifts were strongly related to observed changes in climatic water balance, consistent with theoretical predictions. Downhill shifts were most prominent for species occurring at higher elevations where environmental conditions were marginal. Downhill shifts were observed at nested spatial scales where changes in climatic conditions were consistent, but at all scales were unrelated to species ecological traits. Niche models based entirely on climatic variables were highly accurate both within and across time periods. The inclusion of fire occurrence as an additional explanatory variable did not affect model likelihood or niche model transferability, due primarily to climatic influences on fire occurrence. Departure from historical return interval influenced total model likelihood when it was included as an additional explanatory variable for species adapted to high frequency return intervals, but did not improve model transferability for most species. Regeneration of tree species occurred within a narrower range of climatic conditions than adults. Species with greater niche breadth displayed greater differences between adult and regeneration niches. Both adults and juveniles displayed higher sensitivity to climatic variables representing mortality risk than to variables representing growth potential. Spatially explicit models of regeneration indicated overestimation of tree ranges based on niche models and the potential for future range contractions. These results were consistent across species
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