3,305 research outputs found

    Caragana Establishment, Survival and Regeneration in the Black Hills, South Dakota

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    The purpose of this study was to determine the adaptability and potential wildlife value of Caragana also known as Siberian peashrub for establishment, survival, growth, regeneration, and nutritional qualities. This study was initiated in 1968 in the Black Hills, South Dakota on the McVey Burn (1939), within an open stand of a ponderosa pine forest. Bare rootstock was planted in 1968, and after 35 years survival was 74 percent. Average height was 3 m (10 feet) and plants did regenerate by seed bt did not expand into adjacent habitat. Ideal growing condition evaluated at 35 years, was in a closed tree canopy with 35 percent overstory and basal area 17.7 m2/ha (77 ft2/ acre). Open growing conditions was had exposed areas, canopy cover 17 percent and basal area 5.4 m2/ha (24 ft2/acre). Tree overstory cover on North facing slopes was approximately 2 times greater than on more open south facing slopes. Caragana has not shown signs of spreading from original planting sites. A model developed for habitat assignment defining Closed and Open tree overstory cover for growth, regeneration, and establishment for future sites was 90 percent accurate. Utilization of Caragana by deer based on volume (length x width x height) was 77 percent, 12 years after establishment, with greatest use on south facing slopes. Nutritional qualities of Caragana are generally greater than native shrubs for winter use, with only phosphorous being marginal. The adaptability of Caragana and its qualities makes this browse species suitable for white-tailed deer use for winters. Plantations of Caragana in key wintering areas for white-tailed deer on south facing slopes with Open tree overstory cover and low basal area is recommended for restoration on over browsed ranges

    Energy and Climate Change: Key Lessons for Implementing the Behavioral Wedge

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    The individual and household sector accounts for roughly 40 percent of United States energy use and carbon dioxide emissions, yet the laws and policies directed at reductions from this sector often reflect a remarkably simplistic model of behavior. This Essay addresses one of the obstacles to achieving a “behavioral wedge” of individual and household emissions reductions: the lack of an accessible, brief summary for policymakers of the key findings of behavioral and social science studies on household energy behavior. The Essay does not provide a comprehensive overview of the field, but it discusses many of the leading studies that demonstrate the extent and limits of rational action. These studies can inform lawyers and policymakers who are developing measures to reduce energy use and carbon emissions and can serve as an entry point for more detailed studies of the literature. An effective response to the climate change problem will require substantial reductions in energy demand in addition to new developments in low-carbon energy supplies. The individual and household sector presents a major opportunity: the sector accounts for roughly 40% of U.S. carbon emissions and a comparable percentage of total U.S. energy production, and it is one of the most promising areas for reducing emissions. A recent analysis estimates that behavioral measures directed at this sector could reasonably be expected to reduce total US emissions by over 7% by 2020, an amount larger than the combined emissions from several of the largest-emitting industrial sectors and larger than the total emissions of France. In many cases, these emissions reductions can be achieved at less cost than the leading alternatives. Despite this opportunity, recent regulatory and policy efforts are only beginning to direct substantial attention to the individual and household sector. Findings from the social sciences provide valuable insights into how to capitalize on this opportunity, yet policymakers often have little time to develop new polices and are confronted with a barrage of often-conflicting approaches and theories. This Essay addresses the policy-making challenge by distilling the findings from a broad range of fields into several key principles for those developing energy and climate laws and policies. The principles we outline here are a starting point for policymakers working in this area. We attempt to provide insight into which principles are most relevant to law and policy, but instructions as to how to incorporate these principles are beyond the scope of this essay. The principles include only a subset of the insights from the behavioral and social science literature. In many cases, adherence to multiple principles will be necessary to develop the most effective policy design. Policymakers should consult the body of work referenced here, as well as experts in the social sciences to further their understanding of these and other principles. More extensive reviews of this literature and its relevance to energy and climate policy are also available

    Scientific mindfulness: a foundation for future themes in international business

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    We conceptualize new ways to qualify what themes should dominate the future IB research agenda by examining three questions: Whom should we ask? What should we ask and which selection criteria should we apply? What are the contextual forces? We propose scientific mindfulness as the way forward for generating themes in IB research

    BRIGHT METAL-POOR STARS FROM THE HAMBURG/ESO SURVEY. II. A CHEMODYNAMICAL ANALYSIS

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    We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B <14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of T[subscript eff], log, g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local—about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell "weak metal" candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin.National Science Foundation (U.S.) (CAREER Grant AST 12-55160)Massachusetts Institute of Technology. Silverman (1968) Family Career Development Professorshi

    Tightening the knot in phytochrome by single molecule atomic force microscopy

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    A growing number of proteins have been shown to adopt knotted folds. Yet the biological roles and biophysical properties of these knots remain poorly understood. We have used protein engineering and atomic force microscopy to explore single-molecule mechanics of the figure-of-eight knot in the chromophore-binding domain of the red/far red photoreceptor, phytochrome. Under load, apo phytochrome unfolds at forces of ~47 pN, while phytochrome carrying its covalently bound tetrapyrrole chromophore unfolds at ~73 pN. These forces are among the lowest measured in mechanical protein unfolding, hence the presence of the knot does not automatically indicate a super-stable protein. Our experiments reveal a stable intermediate along the mechanical unfolding pathway, reflecting sequential unfolding of two distinct subdomains in phytochrome, potentially the GAF and PAS domains. For the first time, our experiments allow direct determination of knot size under load. In the unfolded chain, the tightened knot is reduced to 17 amino acids, resulting in apparent shortening of the polypeptide chain by 6.2 nm. Steered molecular dynamics simulations corroborate this number. Finally, we found that covalent phytochrome dimers created for these experiments retain characteristic photoreversibility, unexpectedly arguing against dramatic rearrangement of the native GAF dimer interface upon photoconversion.Comment: 12 pages plus five figures; has been submitted to Biophysical J. Replacement on 9/16 is ONLY to correct a typo in the meta data; the uploaded file is identical to first versio

    Age- and Sex-Specific Mortality Patterns in an Emerging Wildlife Epidemic: The Phocine Distemper in European Harbour Seals

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    Analyses of the dynamics of diseases in wild populations typically assume all individuals to be identical. However, profound effects on the long-term impact on the host population can be expected if the disease has age and sex dependent dynamics. The Phocine Distemper Virus (PDV) caused two mass mortalities in European harbour seals in 1988 and in 2002. We show the mortality patterns were highly age specific on both occasions, where young of the year and adult (>4 yrs) animals suffered extremely high mortality, and sub-adult seals (1–3 yrs) of both sexes experienced low mortality. Consequently, genetic differences cannot have played a main role explaining why some seals survived and some did not in the study region, since parents had higher mortality levels than their progeny. Furthermore, there was a conspicuous absence of animals older than 14 years among the victims in 2002, which strongly indicates that the survivors from the previous disease outbreak in 1988 had acquired and maintained immunity to PDV. These specific mortality patterns imply that contact rates and susceptibility to the disease are strongly age and sex dependent variables, underlining the need for structured epidemic models for wildlife diseases. Detailed data can thus provide crucial information about a number of vital parameters such as functional herd immunity. One of many future challenges in understanding the epidemiology of the PDV and other wildlife diseases is to reveal how immune system responses differ among animals in different stages during their life cycle. The influence of such underlying mechanisms may also explain the limited evidence for abrupt disease thresholds in wild populations

    Bright Metal-Poor Stars from the Hamburg/ESO Survey. II. A Chemodynamical analysis

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    We obtain estimates of stellar atmospheric parameters for a previously published sample of 1777 relatively bright (9 < B < 14) metal-poor candidates from the Hamburg/ESO Survey. The original Frebel et al. analysis of these stars was able to derive estimates of [Fe/H] and [C/Fe] only for a subset of the sample, due to limitations in the methodology then available. A new spectroscopic analysis pipeline has been used to obtain estimates of Teff , log g, [Fe/H], and [C/Fe] for almost the entire data set. This sample is very local-about 90% of the stars are located within 0.5 kpc of the Sun. We consider the chemodynamical properties of these stars in concert with a similarly local sample of stars from a recent analysis of the Bidelman and MacConnell 'weak metal' candidates by Beers et al. We use this combined sample to identify possible members of the halo stream of stars suggested by Helmi et al. and Chiba & Beers, as well as stars that may be associated with stripped debris from the putative parent dwarf of the globular cluster Omega Centauri, suggested to exist by previous authors. We identify a clear increase in the cumulative frequency of carbon-enhanced metal-poor (CEMP) stars with declining metallicity, as well as an increase in the fraction of CEMP stars with distance from the Galactic plane, consistent with previous results. We also identify a relatively large number of CEMP stars with kinematics consistent with the metal-weak thick-disk population, with possible implications for its origin.T.C.B., D.C., V.M.P., and S.D. acknowledge partial support for this work from grants PHY 08-22648, Physics Frontier Center/JINA, and PHY 14-30152, Physics Frontier Center/ JINA Center for the Evolution of the Elements, awarded by the US National Science Foundation. S.R. acknowledges partial support for this work from CAPES, CNPq, FAPESP, and INCT. Y.S.L. acknowledges partial support from the National Research Foundation of Korea (NRF) to the Center for Galaxy Evolution Research and Basic Science Research Program, funded by the Ministry of Science, ICT, and Future Planning (NRF-2015R1C1A1A02036658). A.F. acknowledges funding from NSF-CAREER grant AST 12-55160 and from the Silverman (1968) Family Career Development Professorship. The study at RSAA, ANU, of the Galaxyʼs metal-poor stars is supported by Australian Research Council grants DP0663562 and DP0984924, which J.E.N. is pleased to acknowledge
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