4,280 research outputs found

    Watered Down: The Challenges of Managing Water Resources in Montana

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    Like much of the American West, Montana sits in the cross hairs of climate change. State drought resiliency projects and cooperative watershed management are on the rise in the face of decreased snowpack, early runoff, precipitation variability and lower seasonal stream flows. Population growth, land use practices, recreation and tourism all contribute to pressures on state water supplies. Montana is faced with the arrival of invasive species that threaten the ecological health of its lakes, rivers and streams. State budget constraints and depressed agency capacity are hurting our ability to fend off these threats. There’s a lack of public education necessary to bolster our defenses and make combating invasive species a priority among state lawmakers. Statewide water infrastructure is outdated, inefficient and in need of a massive overhaul. According to the American Society of Civil Engineers, many of the public water systems serving Montana’s cities and towns have distribution and transmission piping that is 75 to 100 years old, with a majority experiencing significant losses of water. In 2014, the ASCE noted that more than 50 percent of these systems reported that their working capacity is five years or less. Inadequate water infrastructure also contributes to increased public health risks to communities. State data shows that of the state’s 700 public water systems, more than 1 in 5 are currently not in compliance with monitoring and other regulatory requirements. Small public water systems are especially prone to contamination. Together, all of these pressing problems – climatic and ecological shifts, defunded state programs or agencies, poor infrastructure and public detachment – create a complex set of obstacles to better water management. The primary goal of my Master’s Portfolio and the reporting therein is to raise awareness and effectively communicate these issues with the hope that people pay closer attention to how the state manages water resources. Another goal, in the context of each story, is to explore possible solutions and highlight the means to address, discuss and move forward with these issues. Finally, my portfolio seeks to reflect Montana voices that are directly impacted by our state’s water resources, but are often neglected

    H2 molecule in strong magnetic fields

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    The Pauli-Hamiltonian of a molecule with fixed nuclei in a strong constant magnetic field is asymptotic, in norm-resolvent sense, to an effective Hamiltonian which has the form of a multi-particle Schr\"odinger operator with interactions given by one-dimensional \delta-potentials. We study this effective Hamiltonian in the case of the H2 -molecule and establish existence of the ground state. We also show that the inter-nuclear equilibrium distance tends to 0 as the field-strength tends to infinity

    Prevention of muscle wasting and osteoporosis: the value of examining novel animal models

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    Bone mass and skeletal muscle mass are controlled by factors such as genetics, diet and nutrition, growth factors and mechanical stimuli. Whereas increased mechanical loading of the musculoskeletal system stimulates an increase in the mass and strength of skeletal muscle and bone, reduced mechanical loading and disuse rapidly promote a decrease in musculoskeletal mass, strength and ultimately performance (i.e. muscle atrophy and osteoporosis). In stark contrast to artificially immobilised laboratory mammals, animals that experience natural, prolonged bouts of disuse and reduced mechanical loading, such as hibernating mammals and aestivating frogs, consistently exhibit limited or no change in musculoskeletal performance. What factors modulate skeletal muscle and bone mass, and what physiological and molecular mechanisms protect against losses of muscle and bone during dormancy and following arousal Understanding the events that occur in different organisms that undergo natural periods of prolonged disuse and suffer negligible musculoskeletal deterioration could not only reveal novel regulatory factors but also might lead to new therapeutic options. Here, we review recent work from a diverse array of species that has revealed novel information regarding physiological and molecular mechanisms that dormant animals may use to conserve musculoskeletal mass despite prolonged inactivity. By highlighting some of the differences and similarities in musculoskeletal biology between vertebrates that experience disparate modes of dormancy, it is hoped that this Review will stimulate new insights and ideas for future studies regarding the regulation of atrophy and osteoporosis in both natural and clinical models of muscle and bone disuse

    The Total Synthesis of (–)-Scabrolide A

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    The first total synthesis of the norcembranoid diterpenoid scabrolide A is disclosed. The route begins with the synthesis of two chiral pool-derived fragments, which undergo a convergent coupling to expediently introduce all 19 carbon atoms of the natural product. An intramolecular Diels–Alder reaction and an enone–olefin cycloaddition/fragmentation sequence are then employed to construct the fused [5–6–7] linear carbocyclic core of the molecule and complete the total synthesis

    Angular Power Spectrum Estimation of Cosmic Ray Anisotropies with Full or Partial Sky Coverage

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    We study the angular power spectrum estimate in order to search for large scale anisotropies in the arrival directions distribution of the highest-energy cosmic rays. We show that this estimate can be performed even in the case of partial sky coverage and validated over the full sky under the assumption that the observed fluctuations are statistically spatial stationary. If this hypothesis - which can be tested directly on the data - is not satisfied, it would prove, of course, that the cosmic ray sky is non isotropic but also that the power spectrum is not an appropriate tool to represent its anisotropies, whatever the sky coverage available. We apply the method to simulations of the Pierre Auger Observatory, reconstructing an input power spectrum with the Southern site only and with both Northern and Southern ones. Finally, we show the improvement that a full-sky observatory brings to test an isotropic distribution, and we discuss the sensitivity of the Pierre Auger Observatory to large scale anisotropies.Comment: 16 pages, 6 figures, version accepted for publication by JCA

    Effects of water availability on the germination of native and exotic forbs

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    Native and Exotic Forbes Germination Response to Drought Stress Beau R. Jennings, Mandy L. Slate, Dean E. Pearson Abstract The shifting climate of the western North American grasslands is forecasted to continue the trend of decreased annual rainfall and longer phases of rain-free windows in times where rainfall has been previously abundant. This understanding has inspired many studies on how ecosystems will respond to these changes. One of the key factors in the shaping of the ecosystem is the availability of precipitation in the spring, which will limit plant recruitment and seedling survival for the dryland ecosystem. Furthermore, seedling’s ability to establish themselves prior to hot dry summers is a key attribute to ensuring success in survival and reproduction. Yet, the expansion of exotic over native species in dryland ecosystems suggests that some exotic plants have traits that allow them to succeed at a higher success rate than native plants. Specifically, understanding the germination tendencies of exotic and native forbes will allow better predictions to be made on the future shaping of these ecosystems. We conducted an experiment in a lab comparing germination percentages and rates of germination for multiple species of native and exotic grassland forbs under different levels of water availability. The experiment was conducted in a growth chamber where temperature, lighting, and humidity were kept as constant variables. The specimens were placed in petri dishes on top of filter paper, and each petri dish lid had three ⅛” holes to allow some evaporation. We hydrated seeds with either 2ml and 3ml daily or every other day. Specimens were examined daily in order to record germination promptly. We will present a comparison of Germination synchrony, germinability, time to germination, germination t50, and germination range between native and exotic forbes species, and discuss how these findings may be used to better understand the processes in which exotic plants are able to overtake plants in their native habitats

    Acute Effects of Plyometric and Resistance Training on Running Economy in Trained Runners

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    Results regarding the acute effects of plyometric and resistance training (PRT) on running economy (RE) are conflicting. Eight male collegiate distance runners (21 +/- 1 years, 62.5 +/- 7.8 ml/kg/min V[Combining Dot Above]O2 peak) completed V[Combining Dot Above]O2 peak and 1 repetition maximum (1RM) testing. Seven days later, subjects completed a 12 minute RE test at 60% and 80% V[Combining Dot Above]O2 peak, followed by a PRT protocol or a rested condition of equal duration (CON). The PRT protocol consisted of 3 sets of 5 repetitions at 85% 1RM for barbell squats, Romanian deadlifts, and barbell lunges; the same volume was utilized for resisted lateral lunges, box jumps, and depth jumps. Subjects completed another RE test immediately following the treatments as well as 24 hours later. Subjects followed an identical protocol six days later with condition assignment reversed. RE was determined by both relative V[Combining Dot Above]O2 (ml/kg/min) as well as energy expenditure (kcal/min). There was a significant (p \u3c 0.05) between-trial increase in V[Combining Dot Above]O2 (37.1 +/- 4.2 ml/kg/min PRT vs. 35.5 +/- 3.9 ml/kg/min CON) and energy expenditure (11.4 +/- 1.3 kcal/min PRT vs. 11.0 +/- 1.4 kcal/min CON) immediately post-PRT at 60% V[Combining Dot Above]O2 peak, but no significant changes were observed at 80% V[Combining Dot Above]O2 peak. Respiratory exchange ratio (RER) was significantly (p \u3c 0.05) reduced 24 hours post-PRT (0.93 +/- 0.0) as compared to the CON trial (0.96 +/- 0.0) at 80% V[Combining Dot Above]O2 peak. Results indicate that high intensity PRT may acutely impair RE in aerobically trained individuals at a moderate running intensity, but that the attenuation lasts less than 24 hours in duration

    Reliability of BOD POD Measurements Remain High Following a Short Duration Low-Carbohydrate Diet

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    The purpose of the present study was to determine whether expected changes in body weight via a three day low-carbohydrate (CHO) diet will disrupt the reliability of air displacement plethysmography measurements via BOD POD. Twenty-four subjects recorded their typical diets for three days prior to BOD POD and seven-site skinfold analyses. Subjects were matched for lean body mass and divided into low-CHO (LC) and control (CON) groups. The LC group was given instruction intended to prevent over 50 grams/day of carbohydrate consumption for three consecutive days, while the CON group replicated their previously recorded diet. Body composition measurements were repeated post-dietary intervention. Test -retest reliability measures were significant (p \u3c 0.01) and high for body fat percentage in both the LC and CON groups (r = 0.993, 0.965, respectively). Likewise, skinfold analysis for body fat percentage reliability was high in both groups (r = 0.996, 0.997, respectively). There were significant differences between first and second BOD POD measurements for body mass (72.9 ± 13.3 vs. 72.1 ± 13.0 kg) and body volume (69.0 ± 12.7 to 68.1 ± 12.2 L) in the LC group (p \u3c 0.05). However, there were no differences (p \u3e 0.05) in BOD POD-determined body fat percentage, lean body mass, or fat mass between the first and second trial in either groups. Body composition measures via BOD POD and seven-site skinfolds remain reliable after three days of a LC diet despite significant decreases in body mass
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