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We quantified relationships between a suite of landscape metrics measured at different spatial scales and sizes of home ranges for female mule deer (Odocoileus hemionus) to test whether spatial heterogeneity played a major role in determining the distribution of deer. We collected data on female mule deer and their habitats at five diverse study sites that spanned the length of California, USA. Sizes of home ranges (95% adaptivekernel analysis) for 80 adult female mule deer varied markedly among individual deer (39-2878 ha) and among the five study sites (range of means for each study site, 49-1138 ha). We measured landscape metrics within varying radii (250, 500, 1000, and 2000 m) from the center of the home range for each deer. Landscape metrics such as edge density, mean shape index, and double-log fractal dimension were inversely correlated with the size of log e -transformed home ranges in deer across all spatial scales. Mean nearest neighbor and contagion index were positively correlated with home-range size across all scales. Significant responses of other metrics such as mean patch size, patch size coefficient of variation, mean edge contrast index, and patch richness density were scale dependent; that is, evident at some spatial scales but not others. We explicitly tested the role of spatial heterogeneity in determining home-range size in female mule deer using a multiple-regression model at the 2000-m scale, which included patch richness density, mean nearest neighbor, mean shape index, and mean edge contrast index. That model explained 57% of the variation in home-range size of mule deer. Models at successively smaller spatial scales explained progressively less of the variation in sizes of deer home ranges.Although home-range size in mule deer was expected to vary with an array of landscape and other variables such as season, reproductive status, and availability of food and water, we explained much of the variation in home-range size with metrics related specifically to heterogeneity of habitats. That outcome highlights the potential importance of spatial heterogeneity in determining the distribution of large herbivores. Such landscape metrics largely have been ignored in attempting to understand the dynamics of home ranges of animals. Better correspondence between landscape heterogeneity and home-range size at larger spatial scales further indicated that mule deer likely made decisions about habitat selection at scales larger than their home ranges. That result has implications for models of habitat choice that rely on home-range size as the appropriate scale for analyses. Moreover, our results indicated that habitat heterogeneity was more important than single landscape measures, such as the amount of habitat edge, in determining home-range size. That outcome has consequences for paradigms used to manage habitats for large herbivores. Finally, we believe that incorporating knowledge concerning habitat heterogeneity into the design of landscape treatments holds the potential to affect the distributi...

An entomologic index based on density estimates of Lyme disease spirochete-infected nymphal deer ticks (lxodes scapularis) was developed to assess human risk of Lyme disease. The authors used a standardized protocol to determine tick density and infection in numerous forested sites in six Rhode Island towns. An entomologic risk index calculated for each town was compared with the number of human Lyme disease cases reported to the Rhode Island State Health Department for the same year. A strong positive relation between entomologic risk index and the Lyme disease case rate for each town suggested that the entomologic index was predictive of Lyme disease risk.

Venous thromboembolism (VTE) is the third most common cause of vascular mortality worldwide and comprises deep-vein thrombosis (DVT) and pulmonary embolism (PE). In this review, we discuss how an understanding of VTE epidemiology and the results of thromboprophylaxis trials have shaped the current approach to VTE prevention. We will discuss modern thromboprophylaxis as it pertains to genetic risk factors, exogenous hormonal therapies, pregnancy, surgery, medical hospitalization, cancer, and what is known thus far about VTE in COVID-19 infection.

We quantified relationships between a suite of landscape metrics measured at different spatial scales and sizes of home ranges for female mule deer (Odocoileus hemionus) to test whether spatial heterogeneity played a major role in determining the distribution of deer. We collected data on female mule deer and their habitats at five diverse study sites that spanned the length of California, USA. Sizes of home ranges (95% adaptivekernel analysis) for 80 adult female mule deer varied markedly among individual deer (39-2878 ha) and among the five study sites (range of means for each study site, 49-1138 ha). We measured landscape metrics within varying radii (250, 500, 1000, and 2000 m) from the center of the home range for each deer. Landscape metrics such as edge density, mean shape index, and double-log fractal dimension were inversely correlated with the size of log e -transformed home ranges in deer across all spatial scales. Mean nearest neighbor and contagion index were positively correlated with home-range size across all scales. Significant responses of other metrics such as mean patch size, patch size coefficient of variation, mean edge contrast index, and patch richness density were scale dependent; that is, evident at some spatial scales but not others. We explicitly tested the role of spatial heterogeneity in determining home-range size in female mule deer using a multiple-regression model at the 2000-m scale, which included patch richness density, mean nearest neighbor, mean shape index, and mean edge contrast index. That model explained 57% of the variation in home-range size of mule deer. Models at successively smaller spatial scales explained progressively less of the variation in sizes of deer home ranges.Although home-range size in mule deer was expected to vary with an array of landscape and other variables such as season, reproductive status, and availability of food and water, we explained much of the variation in home-range size with metrics related specifically to heterogeneity of habitats. That outcome highlights the potential importance of spatial heterogeneity in determining the distribution of large herbivores. Such landscape metrics largely have been ignored in attempting to understand the dynamics of home ranges of animals. Better correspondence between landscape heterogeneity and home-range size at larger spatial scales further indicated that mule deer likely made decisions about habitat selection at scales larger than their home ranges. That result has implications for models of habitat choice that rely on home-range size as the appropriate scale for analyses. Moreover, our results indicated that habitat heterogeneity was more important than single landscape measures, such as the amount of habitat edge, in determining home-range size. That outcome has consequences for paradigms used to manage habitats for large herbivores. Finally, we believe that incorporating knowledge concerning habitat heterogeneity into the design of landscape treatments holds the potential to affect the distributi...