Brief Note Are Geographic Effects on Life Expectancy in Ohio Spurious Because of Race?

Author Institution: Department of Sociology, Bowling Green State UniversityThe possibility that significant geographic effects on life expectancy found in Ohio may have been spurious because of race is tested in this paper, which utilizes a regression-based technique to estimate life expectancy for selected cities and their suburbs. Using multivariate analysis in conjunction with race-specific regression models we find that, although white life expectancy values exceed those of blacks, the geographic effects described in an earlier paper were not spurious. Because socioeconomic status is associated with both race and geography, these findings provide support for the argument that socioeconomic status plays an instrumental role in differential life expectancy

Geographic Variation of Longevity in Ohio, 1930 and 1980

Author Institution: Department of Sociology, Bowling Green State UniversityAt broad levels (i.e., urban and rural, north and south, state-by-state), variations in longevity have been recorded over time in the United States and elsewhere. However, there is little information on life expectancy variation for specific small areas such as cities and suburbs over time. This is understandable because life expectancy is usually calculated by constructing a life table which has rigorous requirements not usually met by published data for small areas. In this paper, we use a regression-based technique to estimate life expectancy in 1930 and 1980 for selected cities and their suburbs as well as rural counties in Ohio. We examine the variation and changes in life expectancy through multivariate analysis, and find that while differences have narrowed between 1930 and 1980, significant variations in longevity persist among suburban, urban, and rural areas in Ohio

Landscape genetics reveal broad and fine‐scale population structure due to landscape features and climate history in the northern leopard frog (Rana pipiens) in North Dakota

Prehistoric climate and landscape features play large roles structuring wildlife populations. The amphibians of the northern Great Plains of North America present an opportunity to investigate how these factors affect colonization, migration, and current population genetic structure. This study used 11 microsatellite loci to genotype 1,230 northern leopard frogs (Rana pipiens) from 41 wetlands (30 samples/wetland) across North Dakota. Genetic structure of the sampled frogs was evaluated using Bayesian and multivariate clustering methods. All analyses produced concordant results, identifying a major east–west split between two R. pipiens population clusters separated by the Missouri River. Substructuring within the two major identified population clusters was also found. Spatial principal component analysis (sPCA) and variance partitioning analysis identified distance, river basins, and the Missouri River as the most important landscape factors differentiating R. pipiens populations across the state. Bayesian reconstruction of coalescence times suggested the major east– west split occurred ~13–18 kya during a period of glacial retreat in the northern Great Plains and substructuring largely occurred ~5–11 kya during a period of extreme drought cycles. A range‐wide species distribution model (SDM) for R. pipiens was developed and applied to prehistoric climate conditions during the Last Glacial Maximum (21 kya) and the mid‐Holocene (6 kya) from the CCSM4 climate model to identify potential refugia. The SDM indicated potential refugia existed in South Dakota or further south in Nebraska. The ancestral populations of R. pipiens in North Dakota may have inhabited these refugia, but more sampling outside the state is needed to reconstruct the route of colonization. Using microsatellite genotype data, this study determined that colonization from glacial refugia, drought dynamics in the northern Great Plains, and major rivers acting as barriers to gene flow were the defining forces shaping the regional population structure of R. pipiens in North Dakota

A CONCEPTUAL MODEL TO FACILITATE AMPHIBIAN CONSERVATION IN THE NORTHERN GREAT PLAINS

As pressures on agricultural landscapes to meet worldwide resource needs increase, amphibian populations face numerous threats including habitat destruction, chemical contaminants, disease outbreaks, wetland sedimentation, and synergistic effects of these perturbations. To facilitate conservation planning, we developed a conceptual model depicting elements critical for amphibian conservation in the northern Great Plains. First, we linked upland, wetland, and landscape features to specific ecological attributes. Ecological attributes included adult survival; reproduction and survival to metamorphosis; and successful dispersal and recolonization. Second, we linked ecosystem drivers, ecosystem stressors, and ecological effects of the region to each ecological attribute. Lastly, we summarized information on these ecological attributes and the drivers, stressors, and effects that work in concert to influence the maintenance of viable and genetically diverse amphibian populations in the northern Great Plains. While our focus was on the northern Great Plains, our conceptual model can be tailored to other geographic regions and taxa