7,005 research outputs found

    2001 Platte River Basin Ecosystem Symposium Proceedings

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    Over 75 people braved the wintry weather to attend the Eleventh Platte River Basin Ecosystem Symposium that convened in Kearney on 27 February 2001. Icy roads lead to cancellation of only 2 papers. Seventeen papers were presented and 5 posters were on display. Nebraska Public Radio and NTV News covered the event. The presentations were excellent and participants were well satisfied with not only the program but also the food. This year the symposium broadened its charge to include more discussion on community-based environmental protection, sustainable development, and policy-making. The Symposium was sponsored by the University of Nebraska Cooperative Extension Platte Watershed Program in cooperation with the U.S. Environmental Protection Agency - Region VII, the U.S. Department of Agriculture/CSREES, the U.S. Fish and Wildlife Service, and the University of Nebraska Water Center. ‱ Part I of the proceedings contains papers submitted for publication. ‱ Part II contains a complete set of abstracts of oral and poster presentations. Part I: Papers Instream Flow Rights for the Platte River- A Major Tributary of the Missouri River Eugene J. Zuerlein , J.L. Hutchinson, Steve Schainost, and Ross Lock. Nebraska Game and Parks Commission Endangered Species Act / Recovery Drives Platte River Cooperative Agreement Jerry Vandersnick, Kearney NE Converting Row Crop Area to Permanent Pasture Bob Scriven, UN Coop Extension, Kearney NE Do You See What I See?: Looking at Conservation and Sustainability in the Central Platte Valley from an Anthropological Perspective John T. Heaston, The Nature Conservancy, Aurora, NE Wintering Bald Eagle Survey of the CNPPID Supply Canal and Lake McConaughy 1992-1999 Mark M. Peyton, Central Nebraska Public Power and Irrigation District, Gothenburg, NE Upper Platte River Fish Diversity and Abundance Sampling 1997 and 1998 Mark M. Peyton, Central Nebraska Public Power and Irrigation District, Gothenburg, NE Part II: Abstracts Mapping Sandhill Crane Roost Sites Along the Central Platte River Using Aerial Infrared Videography P.J. Kinzel, U.S.Geological Survey, Water Resources Division, Denver CO; R.S. Parker, U. S. Geological Survey, Denver CO; J.M. Nelson, U. S. Geological Survey, Denver, CO; M. Starbuck, U.S. Geological Survey, Rolla, MO; L. Davis, Davis Aviation Is Stability of the Platte River Myth or Reality? A. Steele Becker and Jacqueline V. Becker, Department of Geography and Earth Science, University of Nebraska at Kearney, Kearney NE Soil Vegetation Correlations along Hydrologic Gradients in the Platte River Wet Meadows Andrew W. Simpson and Harold G. Nagel, Department of Biology, University of Nebraska at Kearney, NE From Main Channel to Riverine Landscape: Maintaining Hydrological Connectivity on the Platte River Floodplain Wanli Wu, School of Natural Resource Sciences, University of Nebraska-Lincoln, Lincoln, NE Linking the Hydroperiod to Riparian Grassland Plant Species of the Platte River in central Nebraska Robert J. Henszey and Kent Pfeiffer, Platte River Whooping Crane Maintenance Trust, Wood River, NE; Janet Keough, USGS Patuxent Wildlife Research Center, Laurel, MD Land Management Effects on Invertebrate Diversity in Riparian Meadows of the Platte River in South-Central Nebraska Justin R. Krahulik and W. Wyatt Hoback, Department of Biology, University of Nebraska at Kearney, Kearney NE; Craig A. Davis, Whooping Crane Maintenance Trust, Inc., Wood River NE Alternative Methods to Maintain and Enhance Wet Meadow Habitat Along the Platte River, Nebraska Mark M. Czaplewski, Central Platte NRD, Grand Island NE; James J. Jenniges, Nebraska Public Power District, Kearney NE; Mark J. Humpert, Nebraska Game and Parks Commission, Kearney NE; Mark M. Peyton, Central Nebraska Public Power and Irrigation District, Gothenburg NE Platte River Color-Infrared Orthophotographs Available through the Internet Michael Starbuck, U.S. Geological Survey, Mid-Continent Mapping Center, Rolla, Missouri Reflections on EPAs CBEP Project Robert Fenemore, Project Manager, U.S. EPA Region VII, Kansas City MO The Platte River Corridor Initiative William S. Whitney, Prairie Plains Resource Institute, Aurora NE Influencing the Nest Site Selection of Least Terns and Piping Plovers Jeffrey F. Marcus, University of Nebraska, Lincoln, NE; John J. Dinan, Nebraska Game and Parks Commission; Lincoln, NE; Ron J. Johnson, University of Nebraska, Erin E. Blankenship, University of Nebraska, and Jeanine Lackey, University of Nebraska Factors Influencing Soil Macroinvertebrate Communities in Riparian Grasslands of the Central Platte River Flood Plain Craig A. Davis, Platte River Whooping Crane Maintenance Trust, Wood River, NE; Jane E. Austin, USGS Biological Resources Division, Northern Prairie Wildlife Research Center, Jamestown, ND Changes in Abundance and Distribution of Wintering Canada Geese Along the Platte Rivers of Nebraska, 1960-2000 Mark P. Vrtiska, Nebraska Game and Parks Commission, Lincoln, NE; Nick Lyman, Nebraska Game and Parks Commission, North Platte, NE Changes in Waste Corn Availability Affect Fat Storage by Sandhill Cranes Staging in the Central Platte River Valley, Nebraska Gary L. Krapu and David A. Brandt. USGS, Northern Prairie Wildlife Research Center, Jamestown, ND Yellow-billed Cuckoo Subspecies Designation Along the North Platte River and Other Locations in Nebraska, a New Endangered Taxon? William C. Scharf, Ecological Inventory, Traverse City, M

    Can sexual selection theory inform genetic management of captive populations? A review

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    International audienceCaptive breeding for conservation purposes presents a serious practical challenge because several conflicting genetic processes (i.e., inbreeding depression, random genetic drift and genetic adaptation to captivity) need to be managed in concert to maximize captive population persistence and reintroduction success probability. Because current genetic management is often only partly successful in achieving these goals, it has been suggested that management insights may be found in sexual selection theory (in particular, female mate choice). We review the theoretical and empirical literature and consider how female mate choice might influence captive breeding in the context of current genetic guidelines for different sexual selection theories (i.e., direct benefits, good genes, compatible genes, sexy sons). We show that while mate choice shows promise as a tool in captive breeding under certain conditions, for most species, there is currently too little theoretical and empirical evidence to provide any clear guidelines that would guarantee positive fitness outcomes and avoid conflicts with other genetic goals. The application of female mate choice to captive breeding is in its infancy and requires a goal-oriented framework based on the needs of captive species management, so researchers can make honest assessments of the costs and benefits of such an approach, using simulations, model species and captive animal data

    MyoD- and nerve-dependent maintenance of MyoD expression in mature muscle fibres acts through the DRR/PRR element

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    <p>Abstract</p> <p>Background</p> <p>MyoD is a transcription factor implicated in the regulation of adult muscle gene expression. Distinguishing the expression of <it>MyoD </it>in satellite myoblasts and muscle fibres has proved difficult <it>in vivo </it>leading to controversy over the significance of <it>MyoD </it>expression within adult innervated muscle fibres. Here we employ the <it>MD6.0-lacZ </it>transgenic mouse, in which the 6 kb proximal enhancer/promoter (DRR/PRR) of <it>MyoD </it>drives <it>lacZ</it>, to show that MyoD is present and transcriptionally active in many adult muscle fibres.</p> <p>Results</p> <p>In culture, <it>MD6.0-lacZ </it>expresses in myotubes but not myogenic cells, unlike endogenous <it>MyoD</it>. Reporter expression <it>in vivo </it>is in muscle fibre nuclei and is reduced in <it>MyoD </it>null mice. The <it>MD6.0-lacZ </it>reporter is down-regulated both in adult muscle fibres by denervation or muscle disuse and in cultured myotubes by inhibition of activity. Activity induces and represses <it>MyoD </it>through the DRR and PRR, respectively. During the postnatal period, accumulation of ÎČ-galactosidase correlates with maturation of innervation. Strikingly, endogenous <it>MyoD </it>expression is up-regulated in fibres by complete denervation, arguing for a separate activity-dependent suppression of <it>MyoD </it>requiring regulatory elements outside the DRR/PRR.</p> <p>Conclusion</p> <p>The data show that <it>MyoD </it>regulation is more complex than previously supposed. Two factors, MyoD protein itself and fibre activity are required for essentially all expression of the 6 kb proximal enhancer/promoter (DRR/PRR) of <it>MyoD </it>in adult fibres. We propose that modulation of MyoD positive feedback by electrical activity determines the set point of <it>MyoD </it>expression in innervated fibres through the DRR/PRR element.</p

    Does recognized genetic management in supportive breeding prevent genetic changes in life-history traits?

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    International audienceSupportive breeding is one of the last resort conservation strategies to avoid species extinction. Management of captive populations is challenging because several harmful genetic processes need to be avoided. Several recommendations have been proposed to limit these deleterious effects, but empirical assessments of these strategies remain scarce. We investigated the outcome of a genetic management in a supportive breeding for the Houbara Bustard. At the phenotypic level, we found an increase over generations in the mean values of gamete production, body mass and courtship display rate. Using an animal model, we found that phenotypic changes reflected genetic changes as evidenced by an increase in breeding values for all traits. These changes resulted from selection acting on gamete production and to a lesser extent on courtship display. Selection decreased over years for female gametes, emphasizing the effort of managers to increase the contribution of poor breeders to offspring recruited in the captive breeding. Our results shed light on very fast genetic changes in an exemplary captive programme that follows worldwide used recommendations and emphasizes the need of more empirical evidence of the effects of genetic guidelines on the prevention of genetic changes in supportive breeding

    Distinct roles for Pax7 and Pax3 in adult regenerative myogenesis

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    We assessed viable Pax7−/− mice in 129Sv/J background and observed reduced growth and marked muscle wasting together with a complete absence of functional satellite cells. Acute injury resulted in an extreme deficit in muscle regeneration. However, a small number of regenerated myofibers were detected, suggesting the presence of residual myogenic cells in Pax7-deficient muscle. Rare Pax3+/MyoD+ myoblasts were recovered from Pax7−/− muscle homogenates and cultures of myofiber bundles but not from single myofibers free of interstitial tissues. Finally, we identified Pax3+ cells in the muscle interstitial environment and demonstrated that they coexpressed MyoD during regeneration. Sublaminar satellite cells in hind limb muscle did not express detectable levels of Pax3 protein or messenger RNA. Therefore, we conclude that interstitial Pax3+ cells represent a novel myogenic population that is distinct from the sublaminar satellite cell lineage and that Pax7 is essential for the formation of functional myogenic progenitors from sublaminar satellite cells

    Multi-Dimensional Codebooks for Multiple Access Schemes

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    The sparse code multiple access (SCMA) scheme directly maps the incoming bits of several sources (users/streams) to complex multi-dimensional codewords selected from a specific predefined sparse codebook set. The codewords of all sources are then superimposed and exchanged. The shaping gain of the multi-dimensional constellation of SCMA leads to a better system performance. The decoder’s objective will be to separate the superimposed sparse codewords. Most existing works on SCMA decoders employ message passing algorithm (MPA) or one of its variations, or a combination of MPA and other methods. The system architecture is highlighted and its basic principles are presented. Then, an overview of main multi-dimensional constellations for SCMA systems will be provided. Afterwards, we will focus on how the SCMA codebooks are decoded and how their performance is evaluated and compared

    Euniwell: Maximising Academic And Social Outcomes In Engineering Education

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    The ERASMUS+ European University for Well-Being (EUniWell) alliance’s mission aims to resolve the paradox of Europeans’ relative prosperity against the global security and sustainability challenge. “Maximising Academic and Social Outcomes in Engineering Education” is a project which interprets this contradiction for engineering educators; how to best teach non-technical skills to ensure engineers make the utmost contribution to societal wellbeing? Appreciably, the social outcome for the person who becomes an engineer is positive because the profession is relatively well-paid. Therefore, engineering education is good for social mobility providing the learning environment narrows attainment gaps between disadvantaged and mainstream cohorts. Accordingly, our strategy is to bring together the expertise of the British, French, Italian and Swedish faculties to transfer best practice for professional, business and sustainability skill teaching, while contrasting how their disadvantaged cohorts present. The project has two primary objectives: To understand how partners differ in terms of skill teaching, and how students from disadvantaged backgrounds are accommodated. The paper describes the background and rationale of the project, and its research design and methodology. Although the project is still in progress and data collection is still underway, this paper provides insights and perspectives for engineering educators looking to design similar collaborations to share best practice, while considering engineering identities and their underlying competencies

    Effects of habitat and livestock on nest productivity of the Asian houbara Chlamydotis macqueenii in Bukhara Province, Uzbekistan

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    To inform population support measures for the unsustainably hunted Asian houbara Chlamydotis macqueenii (IUCN Vulnerable) we examined potential habitat and land-use effects on nest productivity in the Kyzylkum Desert, Uzbekistan. We monitored 177 nests across different semi-arid shrub assemblages (clay-sand and salinity gradients) and a range of livestock densities (0–80 km-2). Nest success (mean 51.4%, 95% CI 42.4–60.4%) was similar across four years; predation caused 85% of those failures for which the cause was known, and only three nests were trampled by livestock. Nesting begins within a few weeks of arrival when food appears scarce, but later nests were more likely to fail owing to the emergence of a key predator, suggesting foraging conditions on wintering and passage sites may be important for nest productivity. Nest success was similar across three shrub assemblages and was unrelated to landscape rugosity, shrub frequency or livestock density, but was greater with taller mean shrub height (range 13–67 cm) within 50 m. Clutch size (mean = 3.2 eggs) and per-egg hatchability in successful nests (87.5%) did not differ with laying date, shrub assemblage or livestock density. We therefore found no evidence that livestock density reduced nest productivity across the range examined, while differing shrub assemblages appeared to offer similar habitat quality. Asian houbara appear well-adapted to a range of semi-desert habitats and tolerate moderate disturbance by pastoralism. No obvious in situ mitigation measures arise from these findings, leaving regulation and control as the key requirement to render hunting sustainable

    Evolutionary conservation-evaluating the adaptive potential of species

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    Despite intense efforts, biodiversity around the globe continues to decrease. To cease this phenomenon, we urgently need a better knowledge not only of the true extent of biodiversity, but also of the evolutionary potential of species to respond to environmental change. These aims are the heart of the developing field of Evolutionary conservation. Here, after describing problems associated with implementing evolutionary perspectives into management, we outline how evolutionary principles can contribute to efficient conservation programmes. We then introduce articles from this special issue on Evolutionary conservation, outlining how each study or review provides tools and concepts to contribute to efficient management of species or populations. Ultimately, we highlight what we believe can be future research avenues for evolutionary conservation

    Effects of habitat and land use on breeding season density of male Asian Houbara Chlamydotis macqueenii

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    Landscape-scale habitat and land-use influences on Asian Houbara Chlamydotis macqueenii (IUCN Vulnerable) remain unstudied, while estimating numbers of this cryptic, low-density, over-hunted species is challenging. In spring 2013, male houbara were recorded at 231 point counts, conducted twice, across a gradient of sheep density and shrub assemblages within 14,300 kmÂČ of the Kyzylkum Desert, Uzbekistan. Four sets of models related male abundance to: (1) vegetation structure (shrub height and substrate); (2) shrub assemblage; (3) shrub species composition (multidimensional scaling); (4) remote-sensed derived land-cover (GLOBCOVER, 4 variables). Each set also incorporated measures of landscape rugosity and sheep density. For each set, multi-model inference was applied to generalised linear mixed models of visit-specific counts that included important detectability covariates and point ID as a random effect. Vegetation structure received strongest support, followed by shrub species composition and shrub assemblage, with weakest support for the GLOBCOVER model set. Male houbara numbers were greater with lower mean shrub height, more gravel and flatter surfaces, but were unaffected by sheep density. Male density (mean 0.14 km-2, 95% CI, 0.12‒0.15) estimated by distance analysis differed substantially among shrub assemblages, being highest in vegetation dominated by Salsola rigida (0.22 [CI, 0.20‒0.25]), high in areas of S. arbuscula and Astragalus (0.14 [CI, 0.13‒0.16] and 0.15 [CI, 0.14‒0.17] respectively), lower (0.09 [CI, 0.08‒0.10]) in Artemisia and lowest (0.04 [CI, 0.04‒0.05]) in Calligonum. The study area was estimated to hold 1,824 males (CI: 1,645‒2,030). The spatial distribution of relative male houbara abundance, predicted from vegetation structure models, had the strongest correspondence with observed numbers in both model-calibration and the subsequent year’s data. We found no effect of pastoralism on male distribution but potential effects on nesting females are unknown. Density differences among shrub communities suggest extrapolation to estimate country- or range-wide population size must take account of vegetation composition
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