548 research outputs found
Industrial laser welding: An evaluation
Report describes 10-kW laser welding system, designed to weld large structures made from 1/4-inch and 1/2-inch aluminum (2219) and D6AC steel
Montana Climate Change and Big Game: Things Were Better When They Were Worse
Climate change may influence wildlife populations more than any management challenge in recent history. Within the past year numerous reports and papers have come out relative to wildlife and climate change. Now is the time to start addressing the impacts of these changes in Montana. This paper discusses some of the ways climate change may impact big game populations relative to recent climate data sets for Montana. Length of growing season, winter severity, time of spring green-up, summer heat, drought, all may have direct or indirect impacts on wildlife populations. Indirect impacts include disease and disease vectors. Recent declines in some of our big game species may be attributed in part to climate change. Hunting quotas and seasons have been modified to ameliorate some of the population changes. We must be proactive in assessing the impacts of climate change on Montana wildlife populations in order to apply adaptive management
Baseline performance and emissions data for a single-cylinder, direct-injected diesel engine
Comprehensive fuel consumption, mean effective cylinder pressure, and emission test results for a supercharged, single-cylinder, direct-injected, four-stroke-cycle, diesel test engine are documented. Inlet air-to-exhaust pressure ratios were varied from 1.25 to 3.35 in order to establish the potential effects of turbocharging techniques on engine performance. Inlet air temperatures and pressures were adjusted from 34 to 107 C and from 193 to 414 kPa to determine the effects on engine performance and emissions. Engine output ranged from 300 to 2100 kPa (brake mean effective pressure) in the speed range of 1000 to 3000 rpm. Gaseous and particulate emission rates were measured. Real-time values of engine friction and pumping loop losses were measured independently and compared with motored engine values
A Forty Year Odyssey with Montana Wolves: Beginnings Through Five Years of State Management
This study traces wolf population growth in Montana from initial searches for wolves in 1973, through the first wolf radio-collared in the North Fork Flathead in 1979 up to the 2014 population. Reintroduction of wolves to Yellowstone NP and Central Idaho in 1995 and 1996 resulted in two “non-essential experimental” Montana recovery areas in addition to the Northwest Montana “endangered” recovery area. From early in wolf recovery to present, livestock depredation control actions have removed individuals or packs from the population. The first public harvest of wolves began in 2009, was stopped by legal action in 2010 and resumed in 2011 to present. The Montana population appears to have leveled off at approximately 700-900 wolves. Minimum counts peaked at 653 in 2011 and have been approximately 625 wolves for the last two years. Approximately 60% of Montana’s wolves occupy the Northwest Montana recovery area. Through the 5 years state harvests have been conducted, harvest quotas and restrictions on methods of take have been gradually relaxed. However, those changes have resulted in relatively little change in harvest or in Montana’s wolf population. Wolf depredation control actions have decreased since the advent of public harvests. Wolves are here to stay at about the current population level, assuming no drastic changes in public harvests or wolf control actions
MT Legislature and Wildlife 101
Bob Ream and Jake Troyer will lead an educational discussion about the Montana Legislature. The discussion will center on the best ways to engage with legislators, critical wildlife legislation introduced in the 2015 Montana Legislature, and how you can get involved as a citizen advocate on the issues that are most important to you
Montana Climate Variability: a Challenge for Big Game Management
In recent decades changes in climate have influenced wildlife populations worldwide. This paper presents recent climate data sets for Montana with an emphasis on some ways changes in climate have impacted big game populations and management in our state. Length of growing season, winter severity, time of spring green-up, summer heat, drought, all may have direct or indirect impacts on wildlife populations. Indirect impacts include disease and disease vectors. These changes have implications for how we manage hunting and fishing opportunities. Recent declines in some of our big game species may be attributed in part to climate change. Hunting quotas and seasons have been modified to ameliorate some of the population changes. Further modifications in hunting season structure may be required to maintain hunting opportunities and sustain big game populations
Exposure to chronic mild stress prevents kappa opioid-mediated reinstatement of cocaine and nicotine place preference
Stress increases the risk of drug abuse, causes relapse to drug seeking, and potentiates the rewarding properties of both nicotine and cocaine. Understanding the mechanisms by which stress regulates the rewarding properties of drugs of abuse provides valuable insight into potential treatments for drug abuse. Prior reports have demonstrated that stress causes dynorphin release, activating kappa opioid receptors (KOR) in monoamine circuits resulting in both potentiation and reinstatement of cocaine and nicotine conditioned place preference. Here we report that kappa opioid-dependent reinstatement of cocaine and nicotine place preference is reduced when the mice are exposed to a randomized chronic mild stress (CMS) regime prior to training in a conditioned place preference-reinstatement paradigm. The CMS schedule involves seven different stressors (removal of nesting for 24 h, 5 min forced swim stress at 15°C, 8 h food and water deprivation, damp bedding overnight, white noise, cage tilt, and disrupted home cage lighting) rotated over a 3-week period. This response is KOR-selective, as CMS does not protect against cocaine or nicotine drug-primed reinstatement. This protection from reinstatement is also observed following sub-chronic social defeat stress, where each mouse is placed in an aggressor mouse home cage for a period of 20 min over 5 days. In contrast, a single acute stressor resulted in a potentiation of KOR-induced reinstatement, as previously reported. Prior studies have shown that stress alters sensitivity to opioids and prior stress can influence the pharmacodynamics of the opioid receptor system. Together, these findings suggest that exposure to different forms of stress may cause a dysregulation of kappa opioid circuitry and that changes resulting from mild stress can have protective and adaptive effects against drug relapse
Communications Biophysics
Contains reports on six research projects.National Science Foundation (Grant G-16526)National Institutes of Health (Grant MH-04737-02
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