Evaluating Temporal Differences in Land Cover: Implications for Managing Bobwhite at the Landscape Scale in Virginia

Northern bobwhite (Colinus virginianus) populations have declined substantially across large portions of their range. A number of factors may be contributing to that decline including disease, predation, pesticides, and habitat loss. Of these, habitat loss has emerged as the primary factor. Habitat loss has occurred at large and small scales. It is relatively easy to evaluate bobwhite habitat at the micro scale, but evaluating habitat change at the landscape scale is difficult. The goal of this pilot study was to evaluate a novel technique using aerial imagery and line transects to evaluate both contemporary and historic landscapes effectively, quantifying the differences observed to describe what changes, if any, occurred through time. Contemporary photos were available through the 2013 Virginia Base Mapping Program. Historic photos were obtained via United States Geological Survey (1967 – 1969). Two Virginia Quail recovery Initiative focal counties were chosen for the study, Halifax (south central Piedmont) and Sussex (southeastern Coastal Plain). A 12-class habitat categorization system was developed to use in analysis. We developed a technique that allowed photo interpreters to identify and delineate features at a large scale (\u3e 1:6000) over a wide geographic area. Thirty-five to forty transects were evaluated for each site (n = 7). Favorable habitat decline observed ranged from -2% to -49%. Favorable edge decreased through time in four of five sites in Halifax County. Favorable edge increased dramatically within both Sussex County sites, particularly in the bobwhite focal area. Overall, habitat appears to have improved in Sussex County, and declined significantly in Halifax County. Habitats differed both through time and across the landscape. The largest habitat change noted was conversion from field to forest, predominantly pine. We feel this landscape scale habitat analysis technique holds much promise across the bobwhite’s range

Critical thickness for ferromagnetism in LaAlO3/SrTiO3 heterostructures

In heterostructures of LaAlO3 (LAO) and SrTiO3 (STO), two nonmagnetic insulators, various forms of magnetism have been observed [1-7], which may [8, 9] or may not [10] arise from interface charge carriers that migrate from the LAO to the interface in an electronic reconstruction [11]. We image the magnetic landscape [5] in a series of n-type samples of varying LAO thickness. We find ferromagnetic patches that appear only above a critical thickness, similar to that for conductivity [12]. Consequently we conclude that an interface reconstruction is necessary for the formation of magnetism. We observe no change in ferromagnetism with gate voltage, and detect ferromagnetism in a non-conducting p-type sample, indicating that the carriers at the interface do not need to be itinerant to generate magnetism. The fact that the ferromagnetism appears in isolated patches whose density varies greatly between samples strongly suggests that disorder or local strain induce magnetism in a population of the interface carriers

TMEM45A, SERPINB5 and p16INK4A transcript levels are predictive for development of high-grade cervical lesions

Women persistently infected with human papillomavirus (HPV) type 16 are at high risk for development of cervical intraepithelial neoplasia grade 3 or cervical cancer (CIN3+). We aimed to identify biomarkers for progression to CIN3+ in women with persistent HPV16 infection. In this prospective study, 11,088 women aged 20-29 years were enrolled during 1991-1993, and re-invited for a second visit two years later. Cervical cytology samples obtained at both visits were tested for HPV DNA by Hybrid Capture 2 (HC2), and HC2-positive samples were genotyped by INNO-LiPA. The cohort was followed for up to 19 years via a national pathology register. To identify markers for progression to CIN3+, we performed microarray analysis on RNA extracted from cervical swabs of 30 women with persistent HPV16-infection and 11 HPV-negative women. Six genes were selected and validated by quantitative PCR. Three genes were subsequently validated within a different and large group of women from the same cohort. Secondly, Kaplan-Meier and Cox-regression analyses were used to investigate whether expression levels of those three genes predict progression to CIN3+. We found that high transcript levels of TMEM45A, SERPINB5 and p16INK4a at baseline were associated with increased risk of CIN3+ during follow-up. The hazard ratios of CIN3+ per 10-fold increase in baseline expression level were 1.6 (95% CI: 1.1-2.3) for TMEM45A, 1.6 (95% CI: 1.1-2.5) for p16INK4a, and 1.8 (95% CI: 1.2-2.7) for SERPINB5. In conclusion, high mRNA expression levels of TMEM45A, SERPINB5 and p16INK4a were associated with increased risk of CIN3+ in persistently HPV16-infected women

Effects of experience and body size on refuge choice in the crayfish Orconectes immunis

We investigated whether refuge size or experience with a refuge affected the refuge use of male Orconectes immunis crayfish. Individuals were given choices among seven refuges for 10 consecutive days. Refuges were formed from equal length but different diameter PVC pipe and placed in an array in a random sequence. Three treatments were used. In the Novel Refuge treatment, individuals were placed in a new test arena with a new arrangement of cleaned refuges every day. In the Nonremoval treatment, individuals were left in the same arena with the same set of refuges each day. In the Removal treatment, individuals were removed from the refuges each day but placed back in the same arena with the same set of refuges after the refuges had been cleaned. We found that refuge occupation was correlated with an individual\u27s size; smaller crayfish tended to use smaller refuges than larger crayfish, even though all crayfish could fit in all of the different sized refuges. When first tested, individuals initially chose larger refuges than they would subsequently settle in, suggesting that under duress, they were not as particular about refuge characteristics. Individuals in the Nonremoval and Removal treatments were significantly more consistent in their refuge use than those in the Novel Refuge treatment, suggesting that experience with a particular refuge increased use of that refuge. Individuals from the Novel Refuge treatment that were housed for a month with a single refuge did not increase their use of that sized refuge more than those that were housed without a refuge, indicating that simply occupying a refuge of a given size did not affect refuge preference

Seasonal variation in glucose and insulin is modulated by food and temperature conditions in a hibernating primate

Feast-fast cycles allow animals to live in seasonal environments by promoting fat storage when food is plentiful and lipolysis when food is scarce. Fat-storing hibernators have mastered this cycle over a circannual schedule, by undergoing extreme fattening to stockpile fuel for the ensuing hibernation season. Insulin is intrinsic to carbohydrate and lipid metabolism and is central to regulating feast-fast cycles in mammalian hibernators. Here, we examine glucose and insulin dynamics across the feast-fast cycle in fat-tailed dwarf lemurs, the only obligate hibernator among primates. Unlike cold-adapted hibernators, dwarf lemurs inhabit tropical forests in Madagascar and hibernate under various temperature conditions. Using the captive colony at the Duke Lemur Center, we determined fasting glucose and insulin, and glucose tolerance, in dwarf lemurs across seasons. During the lean season, we maintained dwarf lemurs under stable warm, stable cold, or fluctuating ambient temperatures that variably included food provisioning or deprivation. Overall, we find that dwarf lemurs can show signatures of reversible, lean-season insulin resistance. During the fattening season prior to hibernation, dwarf lemurs had low glucose, insulin, and HOMA-IR despite consuming high-sugar diets. In the active season after hibernation, glucose, insulin, HOMA-IR, and glucose tolerance all increased, highlighting the metabolic processes at play during periods of weight gain versus weight loss. During the lean season, glucose remained low, but insulin and HOMA-IR increased, particularly in animals kept under warm conditions with daily food. Moreover, these lemurs had the greatest glucose intolerance in our study and had average HOMA-IR values consistent with insulin resistance (5.49), while those without food under cold (1.95) or fluctuating (1.17) temperatures did not. Remarkably low insulin in dwarf lemurs under fluctuating temperatures raises new questions about lipid metabolism when animals can passively warm and cool rather than undergo sporadic arousals. Our results underscore that seasonal changes in insulin and glucose tolerance are likely hallmarks of hibernating mammals. Because dwarf lemurs can hibernate under a range of conditions in captivity, they are an emerging model for primate metabolic flexibility with implications for human health

Evaluation of Euler Fluxes for Hypersonic Heating Computations

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/83575/1/AIAA-41605-439.pd