1,359 research outputs found

    On the Diversity of Erosion Control Products: Implications for Snake Entanglement

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    After a road construction project, Texas Department of Transportation (TxDOT) mandates that erosion control products (ECPs) are installed to prevent soil loss and promote plant growth. However, their presence on the landscape pose negative consequences to wildlife via entanglement. TxDOT provides an Approved Products List (APL) of ECPs meeting soil erosion prevention and plant growth standards. In Texas, multiple types of ECPs are produced with a range of materials and attributes to decrease the erosion potential on multiple soil types and slopes. Certain attributes are more likely to lead to snake entanglement (Ebert et al. 2019 Wildl. Soc. Bull.; Fig. 1A & B). The purpose of this study was to quantify the diversity of traits of the erosion control products to determine which products pose the least risk of snake entanglement to limit this additional source of mortality

    The Impact of a Leadership Development Plan on Future Leadership Preparedness: A Descriptive Case Study of the Lead Teachers Program at Owl Elementary School

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    The purpose of this case study was to describe the ways the development leadership plan impacts leadership preparedness for teachers in the Lead Teachers program at Owl Elementary School. The departure of experienced employees potentially impacts an organization negatively and impedes the fulfillment of the leadership positions. A leadership development plan will be generally defined for this study as a systematic and continuous effort to support institutional stability by identifying and developing the appropriate employees to fill the key positions at the suitable time. The transformational leadership theory by Kouzes and Posner framed this case study because it was based on the relationships between the leader and followers with a focus on inspiring, enabling, modeling, challenging, and encouraging. This study followed Creswell’s linear data analysis model to utilize ten individual interviews, observations, and historical document analysis to describe the impact on leadership preparedness. Three themes emerged from the analysis: participation is voluntary, leadership development is valued, and leadership opportunities are important. Findings indicated that having Lead Teachers did not create a formalized leadership development plan that ensured current educators are prepared to lead

    Prospects for a civil/military transport aircraft

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    The similarities and disparities between commercial and military payloads, design features, missions, and transport aircraft are enumerated. Two matrices of civil/military transport aircraft designs were evaluated to determine the most cost effective payloads for a projected commercial route structure and air freight market. The probability of this market developing and the prospects for alternate route structures and freight markets are evaluated along with the possible impact on the aircraft designs. Proposals to stimulate the market and increase the viability of the common aircraft concept are reviewed and the possible impact of higher cargo demand on prospects for common civil/military freighters is postulated. The implications of planned advanced technology developments on the aircraft performance and cost are also considered

    Does Installation Method Affect Snake Entanglement in Erosion Control Blankets?

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    Erosion control blankets (ECBs) are installed at construction sites to mitigate against soil loss and promote plant growth. Wildlife, particularly snakes, are prone to becoming entangled in ECBs that contain fixed‐intersection, small‐diameter polypropylene mesh with multiple layers (Ebert et al. 2019 Wildl. Soc. Bull.; Fig. 1). The majority of ECBs on the Texas Department of Transportation’s Approved Product List contain fixed-intersection mesh, which pose a risk to snakes. Snake entanglements often occur at the edge of an ECB where the snake often passes between the multiple mesh layers (Ebert et al. 2019 Wildl. Soc. Bull.) Burying the edge of an ECB may decrease the risk of snake entanglement by allowing them to pass over the ECB edge reducing their encounters with the multiple layers of mesh netting. We hypothesized burying the ECB edge would reduce snakes attempting to pass through the mesh and reducing their risk of entanglement and that there will be a positive correlation between circumference and entanglement

    High blood pressure and associated risk factors as indicator of preclinical hypertension in rural West Africa: A focus on children and adolescents in The Gambia.

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    Hypertension is fast becoming a major public health problem across sub-Saharan Africa. We sought to determine the prevalence of high blood pressure (BP) and associated risk factors as indicator of preclinical hypertension in a rural Gambian population.We analyzed data on 6160 healthy Gambians cross-sectionally. Attention was given to 5 to <18-year olds (N = 3637), as data from sub-Saharan Africa on this young age group are scarce. High BP was defined as systolic blood pressure (SBP) above the 95th percentile for age-sex specific height z scores in <18-year olds employing population-specific reference values. Standard high BP categories were applied to ≄18-year olds.In <18-year olds, the multivariable analysis gave an adjusted high BP prevalence ratio of 0.95 (95% confidence interval [CI] 0.92-0.98; P = 0.002) for age and 1.13 (95% CI 1.06-1.19; P < 0.0001) for weight-for-height z score (zWT-HT); sex and hemoglobin were not shown to affect high BP. In adults age 1.05 (95% CI 1.04-1.05; P < 0.0001), body mass index z score 1.28 (95% CI 1.16-1.40; P < 0.0001), hemoglobin 0.90 (95% CI 0.85-0.96; P < 0.0001) and high fasting glucose 2.60 (95% CI 2.02-3.36; P < 0.0001, though the number was very low) were confirmed as risk factors for high BP prevalence; sex was not associated.The reported high BP prevalence and associated risk factors in adults are comparable to other studies conducted in the region. The observed high BP prevalence of 8.2% (95% CI 7.4-9.2) in our generally lean young Gambians (<18 years) is alarming, given that high BP tracks from childhood to adulthood. Hence there is an urgent need for further investigation into risk factors of pediatric high BP/hypertension even in rural African settings

    Picosecond timing of Microwave Cherenkov Impulses from High-Energy Particle Showers Using Dielectric-loaded Waveguides

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    We report on the first measurements of coherent microwave impulses from high-energy particle-induced electromagnetic showers generated via the Askaryan effect in a dielectric-loaded waveguide. Bunches of 12.16 GeV electrons with total bunch energy of ∌103−104\sim 10^3-10^4 GeV were pre-showered in tungsten, and then measured with WR-51 rectangular (12.6 mm by 6.3 mm) waveguide elements loaded with solid alumina (Al2O3Al_2 O_3) bars. In the 5-8 GHz TE10TE_{10} single-mode band determined by the presence of the dielectric in the waveguide, we observed band-limited microwave impulses with amplitude proportional to bunch energy. Signals in different waveguide elements measuring the same shower were used to estimate relative time differences with 2.3 picosecond precision. These measurements establish a basis for using arrays of alumina-loaded waveguide elements, with exceptional radiation hardness, as very high precision timing planes for high-energy physics detectors.Comment: 16 pages, 15 figure

    Combined Effects of Experimentally Elevated CORT and Predation Threat on Exploratory and Foraging Behavior of Desmognathus ochrophaeus

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    Amphibian responses to stress are generally mediated through glucocorticoids produced by the hypothalamic–pituitary–interrenal axis. Chronic elevation of glucocorticoids can result in delayed wound healing and growth, but less is known about its influence on behavioral responses to predators. We examined the effect of acute and chronic CORT elevation on exploratory and foraging behaviors of Allegheny Mountain Dusky Salamanders (Desmognathus ochrophaeus) exposed to kairomones from a predatory snake. We established ‘No CORT,\u27 ‘Acute CORT,\u27 and ‘Chronic CORT’ conditions during an 18-d preparation phase by varying salamander exposure to an exogenous source of CORT (0.51 mg/mL) delivered via cutaneous patch. During the trial phase, we conducted assays to evaluate exploratory and foraging behavior of salamanders from the different CORT groups when exposed to snake kairomones or control. Exploratory behavior was examined within a circular arena with a series of surmountable concentric barriers, and foraging behavior was observed within Petri dishes containing Drosophila prey. Salamanders experiencing both Chronic CORT and snake kairomones exhibited the least exploratory behavior, escaped the array with the lowest frequency, climbed the fewest barriers, and delayed their movement. However, foraging behavior (latency to strike at prey, number of strikes, number of prey captured) was not affected by exposure to CORT or snake kairomone. Our findings suggest that artificially elevated CORT can modify some behavioral responses to predator kairomones, but only when individuals experience multiple CORT applications in the period preceding the trials
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