1,390 research outputs found

    James A. Martin

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    A tribute to James A, Marti

    Comparison of Dog Surveys and Fall Covey Surveys in Estimating Fall Population Trends of Northern Bobwhite

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    The use of fall covey surveys to monitor population trends for northern bobwhite (Colinus virginianus; hereafter bobwhite) have been widely used in bobwhite research. Estimates of relative abundance from this monitoring technique are often important in assessing population responses to management practices or annual variation. However, conducting covey call surveys is labor intensive and typically can only be conducted during a narrow time frame. The use of dogs as a research tool may offer an efficient alternative to monitor bobwhite population trends. While dogs have been used in research for many other gallinaceous species, their application for bobwhite has received minimal research. To compare traditional and novel (dog) methods for both relative population abundance and density estimation, we conducted covey call surveys (50 points) and dog transects (32 km) during the fall (Sep-Oct) season from 2012-2014 at Beaver River WMA, Beaver County, Oklahoma, USA. A total of 306 detections were observed through fall covey count surveys, while only 44 detections were observed through dog transect surveys. Fall covey surveys yielded indices of 1.45, 2.04, and 3.21 detections per point count during 2012, 2013, and 2014, respectively. Dog transects yielded 0.23, 0.34, and 0.67 detections per km during 2012, 2013, and 2014, respectively. A Pearson’s correlation coefficient of 0.996 indicated high correlation between indices estimated between both survey methods. However, the low sample size for detections during dog surveys precluded any analysis that would yield bobwhite density estimates. Our results indicate that dog transects can be a method for estimating abundance indices for bobwhite. However, if estimates of bobwhite densities are of interest, then use of dog transect surveys are not recommended as only under high quail densities or with high observer efforts do enough detections accumulate for robust density estimation unless large effort is expended

    Utilization and Impact of Career Services Among Collegiate Athletes

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    Career readiness is a concern within the American educational system, particularly among student-athletes that must manage intense time commitments both on and off the field. Student services have emerged in higher education to support career preparation, but the utilization and impact of these services for collegiate athletes is largely unknown. The systems-theory framework (STF) of career development identifies a multitude of internal and external factors that influence individual career development. Guided by STF, the purpose of this study was to predict the factors that influence collegiate athletes\u27 utilization of career services and resulting perceived career skills. An online questionnaire was distributed to collegiate athletes at a Division I university, resulting in 143 collegiate athletes completing the questionnaire. Multiple regression analysis demonstrated collegiate athletes’ familiarity with career services significantly predicted their utilization of career services. In turn, utilization of only four of nine career services investigated (i.e., Careers Online, Career Fairs, Career Workshops, and Athletic Academic Advisor) significantly predicted perceived career skills positively. Implications for the design and marketing of career services for collegiate athletes are discussed

    Violence in the Dark Ages

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    A wide range of observational and theoretical arguments suggest that the universe experienced a period of heating and metal enrichment, most likely from starbursting dwarf galaxies. Using a hydrodynamic simulation we have conducted a uniquely detailed theoretical investigation of this epoch at the end of the cosmological ``dark ages''. Outflows strip baryons from pre-viralized halos with total masses ≲1010\lesssim10{}^{10} M⊙{}_\odot, reducing their number density and the overall star formation rate, while pushing these quantities toward their observed values. We show that the metallicity of ≲1010\lesssim10{}^{10} M⊙{}_\odot objects increases with size, but with a large scatter, reproducing the metallicity-luminosity relation of dwarf galaxies. Galaxies ≳1010\gtrsim10{}^{10} M⊙{}_\odot form with a roughly constant initial metallicity of 10% solar, explaining the observed lack of metal-poor disk stars in these objects. Outflows enrich roughly 20% of the simulation volume, yielding a mean metallicity of 0.3% solar, in agreement with observations of CIV in QSO absorption-line systems.Comment: 14 pages, 5 figures, condensed preprint version. Minor revisions included, accepted by Ap

    Does the presence of oil and gas infrastructure potentially increase risk of harvest in northern bobwhite?

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    Beyond organisms experiencing direct impacts (mortality) from the presence of anthropogenic features, interactive relationships may exacerbate the effects of anthropogenic disturbance within the context of these features. For example, mortality risk may be affected by the road infrastructure associated with energy development by influencing space use of predators including human hunters. To assess these relationships, we conducted research on northern bobwhite Colinus virginianusacross a hunted and non-hunted area of Beaver River Wildlife Management Area, Oklahoma, using radiotelemetry from 2012–2015. We found that bobwhite mortality risk decreased as the distance from primary roads (m) increased across weeks (hazard ratio [HR] = 1.008, 95% confidence interval [CI] = 1.0003 to 1.0013). The interaction between unit (hunted and non-hunted) and distance from primary roads was not significant (HR = 1.00, 95% CI = 0.999 to 1.001) indicating that hunting pressure was not a likely explanation for the observed decrease in survival related to primary roads. Bobwhite on the hunted unit avoided exposed soil/sparse vegetation ( = -0.01, CI = -0.02 to -0.002) and bare ground ( =-0.01, CI =-0.02 to -0.002) more than bobwhite on the non-hunted unit, however these were weak relationships. No other differences in bobwhite space use were detected related to hunting. Though we were limited to estimating theoretical rather than empirical amounts of hunting pressure during our study, we were unable to detect any negative compounding effects of anthropogenic development and hunting pressure on bobwhite ecology during the hunting season

    Control of a Glove-Based Grasp Assist Device

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    A grasp assist system includes a glove and sleeve. The glove includes a digit, i.e., a finger or thumb, and a force sensor. The sensor measures a grasping force applied to an object by an operator wearing the glove. The glove contains a tendon connected at a first end to the digit. The sleeve has an actuator assembly connected to a second end of the tendon and a controller in communication with the sensor. The controller includes a configuration module having selectable operating modes and a processor that calculates a tensile force to apply to the tendon for each of the selectable operating modes to assist the grasping force in a manner that differs for each of the operating modes. A method includes measuring the grasping force, selecting the mode, calculating the tensile force, and applying the tensile force to the tendon using the actuator assembly

    CHILES: HI morphology and galaxy environment at z=0.12 and z=0.17

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    We present a study of 16 HI-detected galaxies found in 178 hours of observations from Epoch 1 of the COSMOS HI Large Extragalactic Survey (CHILES). We focus on two redshift ranges between 0.108 <= z <= 0.127 and 0.162 <= z <= 0.183 which are among the worst affected by radio frequency interference (RFI). While this represents only 10% of the total frequency coverage and 18% of the total expected time on source compared to what will be the full CHILES survey, we demonstrate that our data reduction pipeline recovers high quality data even in regions severely impacted by RFI. We report on our in-depth testing of an automated spectral line source finder to produce HI total intensity maps which we present side-by-side with significance maps to evaluate the reliability of the morphology recovered by the source finder. We recommend that this become a common place manner of presenting data from upcoming HI surveys of resolved objects. We use the COSMOS 20k group catalogue, and we extract filamentary structure using the topological DisPerSE algorithm to evaluate the \hi\ morphology in the context of both local and large-scale environments and we discuss the shortcomings of both methods. Many of the detections show disturbed HI morphologies suggesting they have undergone a recent interaction which is not evident from deep optical imaging alone. Overall, the sample showcases the broad range of ways in which galaxies interact with their environment. This is a first look at the population of galaxies and their local and large-scale environments observed in HI by CHILES at redshifts beyond the z=0.1 Universe.Comment: 23 pages, 12 figures, 1 interactive 3D figure, accepted to MNRA
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