2,140 research outputs found

    Alpine thermal dynamics and associated constraints on the behavior of mountain goats in Southeast Alaska

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    Thesis (M.S.) University of Alaska Fairbanks, 2015Alpine Caprinae, including mountain goats (Oreamnos americanus), have been described to be sensitive to temperature changes within their summer range and consequently may be forced to select habitats that allow for the maintenance of a stable core temperature on warm days. Survival may be inhibited if warm ambient temperatures cause mountain goats to reduce time foraging or if too much time is spent on thermoregulatory habitat selection. I investigated mountain goat behavioral activity budgets across alpine temperature gradients in Southeast Alaska using focal animal sampling and scan sampling techniques. I tested the effects of temperature on mountain goat activity and mountain goat elevation. Coupled with the behavioral investigations, I simultaneously monitored elevational temperature gradients using an array of passive thermistors. By monitoring hourly temperatures and deriving near-surface lapse rates, I demonstrate the utility of downscaled, region-specific temperature-elevation profiles for ecological applications rather than making inferences based on broad spatial models. Except in winter, lapse rates within the study area were between -0.3°C 100m⁻¹ and -0.4°C 100m⁻¹, and were not inclusive of the global mean environmental lapse rate (-0.65°C 100m⁻¹). Mountain goats within the study area demonstrated behavioral conservation of their activity budgets by altering their orientation through space and time, rather than incurring thermal and/or nutritional deficits. In addition, the animals took advantage of cooler temperatures at high elevations to bolster thermoneutrality. I highlight the need for behavioral ecology research that links physiological mechanisms and mammalian life history in an effort to predict the fate of a sentinel wildlife species as it copes with a changing environment. Indeed, such indicator species are invaluable to understanding the dynamics of change in ecosystem structure, function, and phenology. Given current warming trends and projections of changing climate regimes being more pronounced at higher latitudes, there is a marked need to better understand thermoregulatory constraints on faunal behavior and the effect of changing landscapes on the distributions and survival of wildlife populations in Alaska

    Hormonal medications and partner odor preferences

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    The ability to recognize kin through the olfactory sense has important survival and evolutionary implications when choosing mates. Failing to recognize kin when making a choice of whom to mate with can lead to an increase in detrimental genetic outcomes in offspring. Previous studies have indicated that normally ovulating heterosexual women and men prefer the body odor of those with dissimilar immune systems than those with similar immune systems. The use of hormonal contraceptives has shown a preference for similar immune system odors. The current study examines whether the use of hormonal medications predicts preference for body odor. Importantly, this research consists to a diverse population, that goes beyond the heteronormative parameters of previous work and addition of hormonal medications other than just the combined oral contraceptive pill. Originally, this study was designed to take biological samples, but the COVID-19 pandemic forced a change to an online survey. In a sample of 282 participants, male, female and non-binary, there were no differential effects of hormonal medication use between sexes. These results suggest that any effect of hormonal medications would not depend on the sex of the person

    Achieving Learning Outcomes in the World of COVID

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    Presenters assessment will explore how focusing on the learning outcomes guides faculty into determining best instructional practices in a remote/hybrid delivery method, illustrating examples of faculty shifting from traditional face-to-face teaching strategies to remote or hybrid teaching strategies, while achieving the same learning outcomes

    Environmental stressors and cooling interventions on simulated soccer performance

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    A thesis submitted to the University of Bedfordshire, in partial fulfilment of therequirements for the degree of Doctor of PhilosophyThe increasing globalization of elite soccer match-play means that soccer players are likely to compete in hot, hypoxic and hot-hypoxic environments over a season. Soccer match-play studies have identified a marked decline in soccer-specific physical performance in the heat and hypoxia due to increasing body temperatures and a reduction in partial pressure of oxygen (PO2), respectively. As hot environments are more prevalent in elite soccer match-play, cooling strategies have been assessed within the literature in an attempt to alleviate these heat-induced- decrements. However, utilising a soccer match-play design makes environmental and interventional inferences difficult to ascertain, as a plethora of match factors and adaptive pacing strategies cause high variability in key physical performance measures within soccer match-play. Therefore, the three experiments within thesis aimed to assess the reliability and validity of a non-motorised treadmill (NMT) based soccer-specific simulation [intermittent Soccer Performance Test - (iSPT)], to enable the reliable investigation of environmental stress on soccer performance and the efficacy of pre- and half-time-cooling to attenuate any heat- induced-decrements. The purpose of experiment 1 was to investigate the reliability and validity of iSPT which utilised a novel speed component called a ‘variable run’. This speed component quantified the distance covered at a self-selected speed above the second ventilatory threshold (VT2speed), which attempted to delimit a ‘high-intensity’ threshold. Twenty male University soccer players completed one maximal oxygen (O2) uptake (V̇ O2max ) test, three familiarisation (FAM) sessions and one peak speed assessment (PSA) on the NMT, before completing the iSPT twice (iSPT1 and iSPT2). The total distance, sprint distance and high-speed distance covered were 8,952 ± 476 m, 1,000 ± 74 m and 2156 ± 140 m, respectively. No significant difference (p>0.05) was found between repeated trials of the iSPT for all physical performance measures and physiological responses. Reliability measures between iSPT1 and iSPT2 showed good agreement [Coefficient of variation: 0.80] compared with statistical guidelines. Furthermore, the variable run phase showed high speed running capacity was significantly decreased (p<0.05) in the last 15 min compared to the first 15 min, showing parity with previous match-play data. Experiment 1 validated the iSPT as a NMT based soccer- specific simulation compared to previous match-play data, and is a reliable tool for assessing and monitoring the physical performance and physiological responses in soccer players. Successfully completing the aim of experiment 1 facilitated the quantification of hot (HOT), hypoxia (HYP) and hot-hypoxia (HH) mediated decrements on maximal soccer-specific performance in experiment 2. Twelve male University soccer players completed three FAM sessions, one PSA and four randomised crossover experimental trials of the intermittent Soccer Performance Test (iSPT) in normoxic-temperate (CON: 18oC 50% rH), HOT (30oC; 50% rH), HYP (1,000m; 18oC 50% rH) and HH (1,000m; 30oC; 50% rH). Physical performance and its performance decrements, body temperatures [rectal (Tre), skin (Tsk) and estimated muscle temperature (Tmu)], heart rate (HR), arterial blood oxygen saturation (SaO2), perceived exertion, thermal sensation (TS), body mass changes, blood lactate (Bla) and plasma volume were all measured. Performance decrements were similar in HOT and HYP [total distance (-4%), high- speed distance (~-8%) and variable run distance (~-12%) covered] and exacerbated in HH [total distance (-9%), high-speed distance (-15%) and variable run distance (-15%)] compared to CON. A 4% increase in peak sprint speed was present in HOT compared with CON and HYP and 7% greater in HH. The sprint distance covered was unchanged (p > 0.05) in HOT and HYP and only decreased in HH (-8%) compared with CON. Body mass (-2%), temperatures (+2- 5%) and TS (+18%) were altered in HOT. Furthermore, SaO2 (-8%) and HR (+3%) were changed in HYP. Similar changes in body mass and temperatures, HR, TS and SaO2 were evident in HH compared to HOT and HYP, however, Bla (p < 0.001) and plasma volume (p <0.001) were only significantly altered in HH. Perceived exertion was elevated (p < 0.05) by 7% in all conditions compared with CON. Regression analysis identified that absolute TS and absolute rise in Tsk and estimated Tmu (r = 0.82, r = 0.84 r = 0.82, respectively; p <0.05) predicted the hot-mediated-decrements in HOT. The hot, hypoxic and hot-hypoxic environments impaired physical performance during iSPT. Future interventions should address the increases in TS and body temperatures, to attenuate these decrements in physical performance. Experiment 3 of this thesis aimed to identify three pre- and half-time-cooling strategies to attenuate the heat-induced-decrements previously seen in experiment 2. Eight male University soccer players completed four randomised experimental trials of iSPT, three with cooling and one control (i.e. No pre- or half-time cooling: CON). The pre- and half-time-cooling interventions involved were 30-min or 15 min in duration, respectively. Ice slurry ingestion (SLURRY), ice packs (PACKS) covering the upper legs and mixed-methods (MM: PACKS and SLURRY) were utilised as the three cooling interventions. Physical performance and its performance decrements, body temperatures (Tre, Tsk and estimated Tmu), HR, perceived exertion, TS, body mass changes and Bla were all measured. Compared with CON, both PACKS and SLURRY pre-cooling significantly reduced (p > 0.05) central (Tre) and peripheral (Tsk and estimated Tmu) body temperatures prior to iSPT, respectively. However, body temperature and physical performance were unchanged during the first half of PACKS and SLURRY compared with CON. The MM pre-cooling significantly reduced all body temperatures and TS both prior to and during the first half which coincided with an improvement in total distance (+3%), high-speed distance (+4%) and variable run distance (+5%) covered. Half-time-cooling via PACKS, SLURRY and MM had no ergogenic effect (p> 0.05) upon physical performance in the second half, compared with CON. The 30 min of mixed-method pre-cooling, via ice packs placed upon the upper legs and ice slurry ingestion, significantly improved simulated soccer performance during the first half, however, future research should identify a valid half-time-cooling strategy to offer further improvements to physical performance in the second half. The main findings within this thesis revealed that the iSPT showed validity with previous soccer match-play data and strong reproducibility between two tests (iSPT1 and iSPT2). Furthermore, the variable run component showed efficacy as sensitive measure of the decrements in high-speed running capability. As the iSPT demonstrated low test-retest error compared with the statistical guidelines and previous NMT based soccer-specific simulations, any changes to physical performance can be attributed to an intervention and not the variability of the measure, unlike in soccer match-play situations. No difference was seen for all physical performance measures in both HOT and HYP, however, the heat and hypoxic-induced- decrements stem from increasing body temperatures and changes to both SaO2 and HR, respectively. Such decrements may have a detrimental effect upon the match outcome. These heat-induced-decrements were attenuated in the first half after 30 min of mixed-methods pre- cooling, however, the 15 min of mixed-methods half-time-cooling did not significantly improve any physical performance measure in the second half. The mixed-method pre-cooling strategy tested within this thesis could go some way in maintaining physical performance during the first half of soccer match-play in hot environments (~30oC). However, future laboratory based research within a controlled environment should look to assess different combinations, times and strategies of cooling which may be applicable to the time constraints associated with elite soccer

    Doppler imaging of AR Lacertae at three epochs

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    Observations from IUE were used to study the structure of the lower chromosphere of AR Lacertae in the light of Mg II k. Sequences of LWR/P-HI images distributed around the binary period at three epochs were obtained. Discrete plage-like regions of enhanced Mg II surface flux in this system are identified. There are temporal variations in the Mg II flux on timescales of hours as well as substantial changes in chromospheric morphology on timescales of years. Even with the limited S/N attainable with the IUE, one can map the gross structures of active stellar atmospheres. With such information, one can begin to study the true 3-D structure of the atmospheres of late-type stars

    Data-driven Strategic Planning

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    Participants will explore strategies for strategic planning that focuses on: (a) selecting, locating, and reporting data; (b) guiding common goals and expectations; (c) defining and implementing an action; (d) setting benchmarks and assessable outcomes; and (e) considering the impact on student learning

    First Amendment, Newsracks and Public Property after City of Lakewood v. Plain Dealer Publishing Co.

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    City of Lakewood v. Plain Dealer Publishing Co., 108 S. Ct. 2138 (interim ed. 1988)

    The Origins of Fluorescent H_2 Emission From T Tauri Stars

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    We survey fluorescent H_2 emission in HST STIS spectra of the classical T Tauri stars (CTTSs) TW Hya, DF Tau, RU Lupi, T Tau, and DG Tau, and the weak-lined T Tauri star (WTTS) V836 Tau. From each of those sources we detect between 41 and 209 narrow H_2 emission lines, most of which are pumped by strong Lyα emission. H_2 emission is not detected from the WTTS V410 Tau. The fluorescent H_2 emission appears to be common to circumstellar environments around all CTTSs, but high spectral and spatial resolution STIS observations reveal diverse phenomenon. Blueshifted H_2 emission detected from RU Lupi, T Tau, and DG Tau is consistent with an origin in an outflow. The H_2 emission from TW Hya, DF Tau, and V836 Tau is centered at the radial velocity of the star and is consistent with an origin in a warm disk surface. The H_2 lines from RU Lupi, DF Tau, and T Tau also have excess blueshifted H_2 emission that extends to as much as -100 km s^(-1). The strength of this blueshifted component from DF Tau and T Tau depends on the upper level of the transition. In all cases, the small aperture and attenuation of H_2 emission by stellar winds restricts the H_2 emission to be formed close to the star. In the observation of RU Lupi, the Lyα emission and the H_2 emission that is blueshifted by 15 km s^(-1) are extended to the SW by ~0".07, although the faster H_2 gas that extends to ~100 km s^(-1) is not spatially extended. We also find a small reservoir of H_2 emission from TW Hya and DF Tau consistent with an excitation temperature of ~2.5 × 10^4 K
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