1,727 research outputs found

    Staying in place during times of change in Arctic Alaska: The implications of attachment,alternatives, and buffering

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    The relationship between stability and change in social-ecological systems has received considerable attention in recent years, including the expectation that significant environmental changes will drive observable consequences for individuals, communities, and populations. Migration, as one example of response to adverse economic or environmental changes, has been observed in many places, including parts of the Far North. In Arctic Alaska, a relative lack of demographic or migratory response to rapid environmental and other changes has been observed. To understand why Arctic Alaska appears different, we draw on the literature on environmentally driven migration, focusing on three mechanisms that could account for the lack of response: attachment, the desire to remain in place, or the inability to relocate successfully; alternatives, ways to achieve similar outcomes through different means; and buffering, the reliance on subsidies or use of reserves to delay impacts. Each explanation has different implications for research and policy, indicating a need to further explore the relative contribution that each makes to a given situation in order to develop more effective responses locally and regionally. Given that the Arctic is on the front lines of climate change, these explanations are likely relevant to the ways changes play out in other parts of the world. Our review also underscores the importance of further attention to the details of social dynamics in climate change impacts and responses

    Ways to Help and Ways to Hinder: Governance for Effective Adaptation to an Uncertain Climate

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    This paper compares two case studies in Alaska, one on commercial fishers of the Bering Sea and Aleutian Islands region and the other on moose hunters of Interior Alaska, to identify how governance arrangements and management strategies enhance or limit people’s ability to respond effectively to changing climatic and environmental conditions. The two groups face similar challenges regarding the impacts of a changing climate on wild fish and game, but they tell very different stories regarding how and under what conditions these impacts challenge their harvest activities. In both regions, people describe dramatic changes in weather, land, and seascape conditions, and distributions of fish and game. A key finding is that the “command-and-control” model of governance in the Alaska Interior, as implemented through state and federal management tools such as registration hunts and short open seasons, limits effective local responses to environmental conditions, while the more decentralized model of governance created by the Limited Access Privilege systems of the Bering Sea allows fishers great flexibility to respond. We discuss ways to implement aspects of a decentralized decision-making model in the Interior that would benefit hunters by increasing their adaptability and success, while also improving conservation outcomes. Our findings also demonstrate the usefulness of the diagnostic framework employed here for facilitating comparative crossregional analyses of natural resource use and management.Ce document établit une comparaison entre deux études de cas effectuées en Alaska, l’une portant sur les pêcheurs commerciaux de la mer de Béring et de la région des Aléoutiennes et l’autre, sur les chasseurs d’orignaux de l’intérieur de l’Alaska. Cette comparaison avait pour but de déterminer comment les ententes de gouvernance et les stratégies de gestion rehaussent ou restreignent l’aptitude des gens à réagir de manière efficace au changement climatique et aux conditions environnementales. Dans le cas des deux groupes, les défis sont semblables en ce qui a trait aux incidences du changement climatique sur le poisson sauvage et le gibier, mais il n’en reste pas moins que les deux groupes témoignent d’histoires très différentes relativement à la façon dont les incidences influencent leurs activités de chasse ou de pêche, et les circonstances dans lesquelles les incidences présentent des défis à leurs activités de chasse ou de pêche. Dans les deux cas, les individus décrivent des changements dramatiques sur le plan des conditions météorologiques, du paysage terrestre et du paysage marin, ainsi que sur le plan de la répartition du poisson et du gibier. Une des grandes observations ayant émané de cette comparaison, c’est que le modèle de gouvernance consistant à « commander et contrôler » qui est en vigueur dans l’intérieur de l’Alaska, tel qu’imposé par les outils de gestion de l’État et du gouvernement fédéral, et qui se traduit notamment par l’enregistrement des chasses et par des saisons de chasse courtes, se trouve à restreindre l’efficacité des réactions locales vis-à-vis des conditions environnementales, tandis que le mode de gouvernance plus décentralisé créé par les systèmes de privilège à accès limité de la mer de Béring donne aux pêcheurs une plus grande souplesse pour réagir. Nous nous penchons sur diverses façons de mettre en oeuvre les aspects d’un modèle de prise de décisions décentralisé dans l’intérieur de manière à ce que les chasseurs en bénéficient en augmentant leur adaptabilité et leur succès, tout en améliorant les résultats de conservation. Nos constatations démontrent aussi l’utilité du cadre diagnostic employé ici pour faciliter les analyses inter-régionales en matière d’utilisation et de gestion des ressources naturelles

    Acute treatment of stroke (except thrombectomy)

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    Purpose of Review: The management of patients with acute stroke has been revolutionized in recent years with the advent of new effective treatments. In this rapidly evolving field, we provide an update on the management of acute stroke excluding thrombectomy, looking to recent, ongoing, and future trials.Recent Findings: Large definitive trials have provided insight into acute stroke care including broadening the therapeutic window for thrombolysis, alternatives to standard dose alteplase, the use of dual antiplatelet therapy early after minor ischemic stroke, and treating elevated blood pressure in intracerebral hemorrhage. Further ongoing and future trials are eagerly awaited in this ever-expanding area.Summary: Although definitive trials have led to improvements in acute stroke care, there remains a need for further research to improve our understanding of pathophysiological mechanisms underlying different stroke types with the potential for treatments to be tailored to the individual

    Agent-Based Model of Navigable Inland Waterway Tow Operation Procedures

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    Transportation modeling within the context of extreme weather events induced by climate change is critical to understand and improve the resilience of transport systems as the world moves further into the 21st century. Among transportation modes, navigable inland waterways in particular face severe challenges to their future reliability as a result of extreme weather events. The economic implications of inland waterway operational efficiencies on commercial shipping have been studied in detail for several decades. Less well understood, however, are the effects of tow operation procedures enacted during adverse river conditions that have resulted from extreme weather events. This paper describes a model of a waterway segment that simulates stakeholder decision making and tow operator behavior to provide stakeholders with insights into the possible benefits of waterway action plans as operational guidance documents. Simulations run for a test area of the navigable inland waterway system indicated that operational procedures recommended in waterway action plans might have a significant impact on waterway operational efficiencies, which suggests that the model may be a useful decision-support tool for waterway stakeholders

    Method of isolating an analyte using a solid phase extraction medium

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    A functionalized macroporous poly(styrene divinylbenzene) particle comprises at least one ionic functional group covalently bonded thereto, the functionalized particle having sorptive capability towards an analyte, said functional group being present in the range of 0.1 to 2.5 milliequivalents per gram of poly(styrene divinylbenzene). The functionalized particles can be used in a packed column or enmeshed in a nonwoven web for utility in solid phase extraction applications

    Nutritional and Demographic Consequences of Varying Elk Migratory Behaviors

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    Elk (Cervus elaphus) populations in the American West exhibit wide variation in migratory behavior. The traditional view of elk migration holds that migratory elk move from winter range in order to track growth of highly nutritious fresh vegetation into higher elevation areas. Non-migratory elk forego this seasonal movement, typically foraging in lower elevation winter range areas throughout the summer. Although the effect of summer nutrition on elk body condition and reproductive success is well known, the nutritional and demographic consequences of these differing migratory behaviors remain unclear. We developed a predictive model of summer forage quality to compare the nutrition available to migrants and non-migrants in a partially migratory population of elk in western Montana. Non-migratory elk had access to significantly higher forage quality than their migratory counterparts; the lower forage quality available to migrants is predicted to result in reduced reproductive success based on published studies linking nutrition with elk demographic rates. We therefore expect non-migrants to have higher fecundity rates and to comprise a higher proportion of the population relative to migrants. Harvest management actions that reduce survival rates of non-migrants or increase survival rates of migrants may be an effective tool for maintaining migratory behavior in partially migratory populations

    Thermal Testing of a Stacked Core Mirror for UV Applications

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    The ASTRO2010 Decadal Survey stated that an advanced large-aperture ultraviolet, optical, near-infrared (UVOIR) telescope is required to enable the next generation of compelling astrophysics and exoplanet science; and, that present technology is not mature enough to affordably build and launch any potential UVOIR mission concept. Under Science and Technology funding, NASA's Marshall Space Flight Center and ITT Exelis have developed a more cost effective process to make 4m monolithic spaceflight UV quality, low areal density, thermally and dynamically stable primary mirrors. A proof of concept mirror was built and tested down to 250K which would allow imaging out to 2.5 microns. This mirror was thermally tested at the Marshall Spaceflight Center to understand the thermal changes between the processing temperature of 293K and the potential low end of the operational temperature of 250K. Isothermal testing results and front plate gradient results have been evaluated and compared to analysis predictions. Measurement of gravity effects on surface figure will be compared to analytical predictions. Future testing of a larger Pathfinder mirror will also be discussed
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