1,603 research outputs found

    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

    The tRNA Synthetase Paralog PoxA Modifies Elongation Factor-P with (R)-ÎČ-lysine

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    The lysyl-tRNA synthetase paralog PoxA modifies elongation factor P (EF-P) with α-lysine at low efficiency. Cell-free extracts containing non–α-lysine substrates of PoxA modified EF-P with a change in mass consistent with addition of ÎČ-lysine, a substrate also predicted by genomic analyses. EF-P was efficiently functionally modified with (R)-ÎČ-lysine but not (S)-ÎČ-lysine or genetically encoded α-amino acids, indicating that PoxA has evolved an activity orthogonal to that of the canonical aminoacyl-tRNA synthetases

    Individual and non‐additive effects of exotic sap‐feeders on root functional and mycorrhizal traits of a shared conifer host

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    Forest pests drive tree mortality through disruption of functional traits linked to nutrient acquisition, growth and reproduction. The impacts of attack by individual or multiple above‐ground herbivores on root functional traits critical to tree health have received little attention. This is especially true for exotic herbivores, organisms often found in disturbed forests. We excavated whole‐root systems from eastern hemlock (Tsuga canadensis) individuals experimentally infested with hemlock woolly adelgid (HWA: Adelges tsugae) and elongate hemlock scale (EHS: Fiorina externa) individually, or in combination, for periods of 2 and 4 years. Below‐ground root biomass, functional traits and storage nutrients were measured to assess impacts of herbivory. We also quantified ectomycorrhizal fungal (EMF) colonisation of fine roots and used culture‐independent methods to examine EMF diversity. Trees infested with HWA had a greater root mass fraction (root to total biomass ratio), although feeding had no observable effects on root functional traits (e.g. specific root length) or on resource allocation to roots. HWA feeding did significantly reduce EMF colonisation of hemlock fine roots, though surprisingly, EMF diversity and that of other fungal associates were unaffected. In contrast to HWA, EHS (alone or in conjunction with HWA) feeding had no observable effect on below‐ground traits or EMF colonisation alone; however, its presence mediated HWA effects when trees were co‐infested. Simultaneous infestation within the same year yielded significant reductions in EMF colonisation, whereas prior EHS attack weakened HWA effects. Our results collectively suggest that prior EHS attack dampens the impact of HWA on below‐ground functional traits. This highlights how the timing and sequence of herbivore arrival can alter plant‐mediated interactions between herbivores and their effects on above–below‐ground linkages and associated tree health

    Atmospheric Acetaldehyde: Importance of Air-Sea Exchange and a Missing Source in the Remote Troposphere.

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    We report airborne measurements of acetaldehyde (CH3CHO) during the first and second deployments of the National Aeronautics and Space Administration (NASA) Atmospheric Tomography Mission (ATom). The budget of CH3CHO is examined using the Community Atmospheric Model with chemistry (CAM-chem), with a newly-developed online air-sea exchange module. The upper limit of the global ocean net emission of CH3CHO is estimated to be 34 Tg a-1 (42 Tg a-1 if considering bubble-mediated transfer), and the ocean impacts on tropospheric CH3CHO are mostly confined to the marine boundary layer. Our analysis suggests that there is an unaccounted CH3CHO source in the remote troposphere and that organic aerosols can only provide a fraction of this missing source. We propose that peroxyacetic acid (PAA) is an ideal indicator of the rapid CH3CHO production in the remote troposphere. The higher-than-expected CH3CHO measurements represent a missing sink of hydroxyl radicals (and halogen radical) in current chemistry-climate models

    Major depression, fibromyalgia and labour force participation: A population-based cross-sectional study

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    BACKGROUND: Previous studies have documented an elevated frequency of depressive symptoms and disorders in fibromyalgia, but have not examined the association between this comorbidity and occupational status. The purpose of this study was to describe these epidemiological associations using a national probability sample. METHODS: Data from iteration 1.1 of the Canadian Community Health Survey (CCHS) were used. The CCHS 1.1 was a large-scale national general health survey. The prevalence of major depression in subjects reporting that they had been diagnosed with fibromyalgia by a health professional was estimated, and then stratified by demographic variables. Logistic regression models predicting labour force participation were also examined. RESULTS: The annual prevalence of major depression was three times higher in subjects with fibromyalgia: 22.2% (95% CI 19.4 – 24.9), than in those without this condition: 7.2% (95% CI 7.0 – 7.4). The association persisted despite stratification for demographic variables. Logistic regression models predicting labour force participation indicated that both conditions had an independent (negative) effect on labour force participation. CONCLUSION: Fibromyalgia and major depression commonly co-occur and may be related to each other at a pathophysiological level. However, each syndrome is independently and negatively associated with labour force participation. A strength of this study is that it was conducted in a large probability sample from the general population. The main limitations are its cross-sectional nature, and its reliance on self-reported diagnoses of fibromyalgia

    Time variation of the fine structure constant in the early universe and the Bekenstein model

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    We calculate bounds on the variation of the fine structure constant at the time of primordial nucleosynthesis and at the time of neutral hydrogen formation. We use these bounds and other bounds from the late universe to test Bekenstein model. We modify the Kawano code, CAMB and CosmoMC in order to include the possible variation of the fine structure constant. We use observational primordial abundances of \De, \He and \Li, recent data from the Cosmic Microwave Background and the 2dFGRS power spectrum, to obtain bounds on the variation of α\alpha. We calculate a piecewise solution to the scalar field equation of Bekenstein model in two different regimes; i) matter and radiation, ii) matter and cosmological constant. We match both solutions with appropriate boundary conditions. We perform a statistical analysis using the bounds obtained from the early universe and other bounds from the late universe to constrain the free parameters of the model. Results are consistent with no variation of α\alpha in the early universe. Limits on α\alpha are inconsistent with the scale length of the theory ll being larger than Planck scale. In order to fit all observational and experimental data, the assumption l>Lpl>L_p implied in Bekenstein's model has to be relaxed.Comment: 13 pages, 8 figures,version accepted to be published in Astronomy and Astrophysic
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