292 research outputs found

    Electrostatic potential on human leukocyte antigen: implications for putative mechanism of chronic beryllium disease.

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    The pathobiology of chronic beryllium disease (CBD) involves the major histocompatibility complex class II human leukocyte antigen (HLA). Although occupational exposure to beryllium is the cause of CBD, molecular epidemiologic studies suggest that specific (Italic)HLA-DPB1(/Italic) alleles may be genetic susceptibility factors. We have studied three-dimensional structural models of HLA-DP proteins encoded by these genes. The extracellular domains of HLA-DPA1*0103/B1*1701, *1901, *0201, and *0401, and HLA-DPA1*0201/B1*1701, *1901, *0201, and *0401 were modeled from the X-ray coordinates of an HLA-DR template. Using these models, the electrostatic potential at the molecular surface of each HLA-DP was calculated and compared. These comparisons identify specific characteristics in the vicinity of the antigen-binding pocket that distinguish the different HLA-DP allotypes. Differences in electrostatics originate from the shape, specific disposition, and variation in the negatively charged groups around the pocket. The more negative the pocket potential, the greater the odds of developing CBD estimated from reported epidemiologic studies. Adverse impact is caused by charged substitutions in positions 55, 56, 69, 84, and 85, namely, the exact same loci identified as genetic markers of CBD susceptibility as well as cobalt-lung hard metal disease. These findings suggest that certain substitutions may promote an involuntary cation-binding site within a putatively metal-free peptide-binding pocket and therefore change the innate specificity of antigen recognition

    Does Personality Affect the Probability That Piute Ground Squrriels (\u3cem\u3eUrocitellus Mollis\u3c/em\u3e) Will Be Shot by Recreational Hunters?

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    Recreational shooting of Piute ground squirrels (Urocitellus mollis) in southern Idaho is an activity growing in popularity. One factor that may influence shooting success is the personality of individuals within a population. We hypothesized that bold individual ground squirrels would be more/less likely to be targeted by a hunter and would be more/less disturbed by gun fire. To test these hypotheses, we simulated recreational shooting to identify which personalities are more susceptible hunters and more responsive to gun fire. We preformed simulations in March of 2015 on a population of Piute ground squirrels with known personalities. Bold and shy individuals were coded by dying the fur of squirrels in a way distinguishable by observers during simulations which took place at three sites with varying vegetative cover. We recorded the frequency of detection of each personality type through a hunting scope. In addition, we observed the behavioral response (e.g. flee, vigilance, alarm call) of ground squirrels to a recording of a .22 caliber fire. We also identified whether raptors were attracted to the simulated shooting area for scavenging in response to the sound of the gun fire. We calculated whether the detection and behavioral responses of squirrel personalities in shooting simulations was disproportionate to that of the marked population. This information can lead to a greater understanding of the role of behavioral factors in the survival of Piute ground squirrels and provide insight into how recreational shooting could influence the personality landscape of a dominant prey species

    Habitat Features Predict the Distribution of Recreational Shooters in the Morley Nelson Snake River Birds of Prey National Conservation Area

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    The Morley Nelson Snake River Birds of Prey National Conservation Area (NCA) is a popular destination of many Treasure Valley residents. There, recreationists participate in various pastimes such as target shooting, recreational shooting/hunting, and wildlife viewing. However, these activities have the potential to interfere with one another. Recreational shooting of Piute ground squirrels (Urocitellus mollis) could affect prey availability and scavenging opportunities for associated raptor species, most notably local golden eagle (Aquila chrysaetos) populations. To assess possible interactions among shooters, prey and raptors, the spatial density and habitat preference of human shooters must be determined. We hypothesized that higher shooter density would be correlated with proximity to high-use roads and habitat with high visibility. To test this hypothesis, the spatial density and habitat preference of human shooters was determined. First, three routes of approximately 16 km each were established throughout the northwest section of the NCA through “hunter hotspots” of various habitat types. Routes were driven on weekends, starting in the morning, from February 28 to March 21, 2015. Data was collected opportunistically on all shooters observed including group size, demographics, location, and the habitat characteristics (e.g. proximity to roads and visibility) of shooting sites. These data were used to determine which habitat features best predicted shooting locations. This study may directly inform future research on golden eagle scavenging ecology, competition between hunters and eagles, and the potential for lead entry into the ecosystem through use of lead ammunition

    Collective modes and correlations in one-component plasmas

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    The static and time-dependent potential and surface charge correlations in a plasma with a boundary are computed for different shapes of the boundary. The case of a spheroidal or spherical one-component plasma is studied in detail because experimental results are available for such systems. Also, since there is some knowlegde both experimental and theoretical about the electrostatic collective modes of these plasmas, the time-dependent correlations are computed using a method involving these modes.Comment: 20 pages, plain TeX, submitted to Phys. Rev.

    A Heterogenous Thermal Environment Enables Remarkable Behavioral Thermoregulation in Uta Stansburiana

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    Ectotherms can attain preferred body temperatures by selecting specific temperature microhabitats within a varied thermal environment. The side-blotched lizard, Uta stansburiana may employ microhabitat selection to thermoregulate behaviorally. It is unknown to what degree habitat structural complexity provides thermal microhabitats for thermoregulation. Thermal microhabitat structure, lizard temperature, and substrate preference were simultaneously evaluated using thermal imaging. A broad range of microhabitat temperatures was available (mean range of 11°C within 1–2 m2) while mean lizard temperature was between 36°C and 38°C. Lizards selected sites that differed significantly from the mean environmental temperature, indicating behavioral thermoregulation, and maintained a temperature significantly above that of their perch (mean difference of 2.6°C). Uta’s thermoregulatory potential within a complex thermal microhabitat structure suggests that a warming trend may prove advantageous, rather than detrimental for this population

    Seasonal shifts in clutch size and egg size in the side-blotched lizard, Uta stansburiana Baird and Girard

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    There is evidence that the side-blotched lizard, Uta stansburiana , and some other organisms of temperate latitudes produce fewer and larger eggs as the reproductive season progresses. There are at least two models that could explain this phenomenon.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47737/1/442_2004_Article_BF00376891.pd
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