2,069 research outputs found

    Steady-state attitude control propulsion systems computer program documentation and user's manual, volume 1

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    Computer program documentation and user manual for steady state attitude control propulsion system - vol.

    Ozone Depletion: International Protective Strategies and Implications

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    Reading the Game: Exploring Narratives in Video Games as Literary Texts

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    Indiana University-Purdue University Indianapolis (IUPUI)Video games are increasingly recognized as powerful tools for learning in classrooms. However, they are widely neglected in the field of English, particularly as objects worthy of literary study. This project argues the place of video games as objects of literary study and criticism, combining the theories of Espen Aarseth, Ian Bogost, Henry Jenkins, and James Paul Gee. The author of this study presents an approach to literary criticism of video games that he names “player-generated narratives.” Through player-generated narratives, players as readers of video games create loci for interpretative strategies that lead to both decoding and critical inspection of game narratives. This project includes a case-study of the video game Undertale taught in multiple college literature classrooms over the course of a year. Results of the study show that a video game introduced as a work of literature to a classroom increases participation, actives disengaged students, and connects literary concepts across media through multimodal learning. The project concludes with a chapter discussing applications of video games as texts in literature classrooms, including addressing the practical concerns of migrating video games into an educational setting

    Economic Values of Saginaw Bay Coastal Marshes

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    We estimate the economic values of Saginaw Bay coastal marshes with multiple methods. First we estimate the value of coastal marsh recreation with two variations of the travel cost method: the single-site recreation demand model and the recreation site selection or random utility model. Using the single site model the current level of day trip recreation in the Saginaw Bay coastal marsh area is valued at almost 16millioneachyear.Thepresentvalueis16 million each year. The present value is 239 million. Using the site selection travel cost model, an increase in 1125 acres of coastal marsh is valued at about 94,000annually.Thepresentvalueis94,000 annually. The present value is 1.83 million. Willingness to pay for recreation and other values of coastal marsh protection is estimated using the contingent valuation method. The annual value of protection of 1125 acres of coastal marsh is 113,000.Thepresentvalueis113,000. The present value is 2.2 million.

    Ocean acidification

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    KEY HEADLINES • Global-scale patterns and processes of ocean acidification are superimposed on other factors influencing seawater chemistry over local to regional space scales, and hourly to seasonal time scales. • Future ocean conditions will depend on future CO2 emissions; there is now international agreement that these should be reduced to net zero, thereby reducing the consequences of both climate change and ocean acidification. • Assessments of ocean acidification by the Intergovernmental Panel on Climate Change (IPCC) gave high or very high confidence to chemical aspects, but a much wider range of confidence levels to projected biological and biogeochemical impacts. Biotic impacts will depend on species-specific responses, interactions with other stressors and food-web effects. • Previous MCCIP statements are considered to still be valid, with increased confidence for some aspects. • Observed pH decreases in the North Sea (over 30 years) and at coastal UK sites (over 6 years) seem more rapid than in the North Atlantic as a whole. However, shelf sea and coastal data sets show high variability over a range of timescales, and factors affecting that variability need to be much better understood. • UK research on ocean acidification has been productive and influential. There is no shortage of important and interesting topic areas that would improve scientific knowledge and deliver societally-important outcomes

    From laboratory manipulations to Earth system models: scaling calcification impacts of ocean acidification

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    The observed variation in the calcification responses of coccolithophores to changes in carbonate chemistry paints a highly incoherent picture, particularly for the most commonly cultured "species", <i>Emiliania huxleyi</i>. The disparity between magnitude and potentially even sign of the calcification change under simulated end-of-century ocean surface chemical changes (higher <i>p</i>CO<sub>2</sub>, lower pH and carbonate saturation), raises challenges to quantifying future carbon cycle impacts and feedbacks because it introduces significant uncertainty in parameterizations used for global models. Here we compile the results of coccolithophore carbonate chemistry manipulation experiments and review how ocean carbon cycle models have attempted to bridge the gap from experiments to global impacts. Although we can rule out methodological differences in how carbonate chemistry is altered as introducing an experimental bias, the absence of a consistent calcification response implies that model parameterizations based on small and differing subsets of experimental observations will lead to varying estimates for the global carbon cycle impacts of ocean acidification. We highlight two pertinent observations that might help: (1) the degree of coccolith calcification varies substantially, both between species and within species across different genotypes, and (2) the calcification response across mesocosm and shipboard incubations has so-far been found to be relatively consistent. By analogy to descriptions of plankton growth rate vs. temperature, such as the "Eppley curve", which seek to encapsulate the net community response via progressive assemblage change rather than the response of any single species, we posit that progressive future ocean acidification may drive a transition in dominance from more to less heavily calcified coccolithophores. Assemblage shift may be more important to integrated community calcification response than species-specific response, highlighting the importance of whole community manipulation experiments to models in the absence of a complete physiological understanding of the underlying calcification process. However, on a century time-scale, regardless of the parameterization adopted, the atmospheric <i>p</i>CO<sub>2</sub> impact of ocean acidification is minor compared to other global carbon cycle feedbacks

    Illegal Shooting is Now a Leading Cause of Death of Birds Along Power Lines in the Western USA

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    Human actions, both legal and illegal, affect wildlife in many ways. Inaccurate diagnosis of cause of death undermines law enforcement, management, threat assessment, and mitigation. We found 410 dead birds collected along 196 km of power lines in four western USA states during 2019–2022. We necropsied these carcasses to test conventional wisdom suggesting that electrocution is the leading cause of death of birds at electrical infrastructure. Of 175 birds with a known cause of death, 66% died from gunshot. Both raptors and corvids were more likely to die from gunshot than from other causes, along both transmission and distribution lines. Past mitigation to reduce avian deaths along power lines has focused almost exclusively on reducing electrocutions or collisions. Our work suggests that, although electrocution and collision remain important, addressing illegal shooting now may have greater relevance for avian conservation
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