559 research outputs found

    Sustainable Grassland Management: An Exploratory Study of Progressive Ranchers in Nebraska

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    Well-managed grasslands provide numerous ecosystem services. Ranchers who employ sustainable grazing practices limit grassland conversion and conserve critical habitats. This phenomenological study explored the grassland management decisions of progressive ranchers in Nebraska. Each individual interviewed for this study is proactive about the state of their grasslands, whether they are motivated by financial or conservation factors. Throughout the evolution of their businesses, these ranchers have taken steps to improve their management techniques and continue to employ new strategies while planning for the long-term productivity of their grasslands. For policy makers and educators seeking to improve grassland management decisions, demonstrating new methods to be economical, promoting stewardship, and allowing for flexible implementation may increase acceptance of recommendations. Because progressive ranchers’ livelihoods are connected to the land, and they are long-term goal oriented, they closely scrutinize, yet are open to advancing grassland management practices that benefit their cash flow, their pastures, their animals, and their families

    Sustainable Grassland Management: An Exploratory Study of Progressive Ranchers in Nebraska

    Get PDF
    Well-managed grasslands provide numerous ecosystem services. Ranchers who employ sustainable grazing practices limit grassland conversion and conserve critical habitats. This phenomenological study explored the grassland management decisions of progressive ranchers in Nebraska. Each individual interviewed for this study is proactive about the state of their grasslands, whether they are motivated by financial or conservation factors. Throughout the evolution of their businesses, these ranchers have taken steps to improve their management techniques and continue to employ new strategies while planning for the long-term productivity of their grasslands. For policy makers and educators seeking to improve grassland management decisions, demonstrating new methods to be economical, promoting stewardship, and allowing for flexible implementation may increase acceptance of recommendations. Because progressive ranchers’ livelihoods are connected to the land, and they are long-term goal oriented, they closely scrutinize, yet are open to advancing grassland management practices that benefit their cash flow, their pastures, their animals, and their families

    Rural Population Health and Aging: Introduction to the Special Issue

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    This special issue of the Journal of Rural Social Sciences (JRSS) focuses on rural population health and aging. It showcases the work of scholars from several backgrounds and social science disciplines to advance knowledge in a critical field of investigation. Assembled through an open call for submissions coordinated through the National Institute on Aging (NIA) funded Interdisciplinary Network on Rural Population Health and Aging (INRPHA), the collection of articles helps inform a more nuanced understanding of the factors associated with rural places, which often have different health outcomes and aging patterns than their urban counterparts. The authors achieve this through application of innovative analytical strategies used with a combination of data sources. This introductory essay provides background and an overview of the four articles, followed by discussion of future opportunities to advance an agenda for rural population health and aging research

    An Integration Testing Facility for the CERN Accelerator Controls System

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    A major effort has been invested in the design, development, and deployment of the LHC Control System. This large control system is made up of a set of core components and dependencies, which although tested individually, are often not able to be tested together on a system capable of representing the complete control system environment, including hardware. Furthermore this control system is being adapted and applied to CERN's whole accelerator complex, and in particular for the forthcoming renovation of the PS accelerators. To ensure quality is maintained as the system evolves, and toimprove defect prevention, the Controls Group launched a project to provide a dedicated facility for continuous, automated, integration testing of its core components to incorporate into its production process. We describe the project, initial lessons from its application, status, and future directions

    Controls on lithium concentration and diffusion in zircon

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    This study was supported by ETH Research Grants ETH-34 15-2 (JS), ETH-14 16-1 (FM) and by Swiss National Science Foundation research grant 200020-153112/1 (NK).Thermal annealing of zircons prior to uranium-lead dating by laser ablation inductively coupled plasma mass spectrometry is a commonly-implemented procedure which improves data accuracy and precision by partially repairing radiation damage from the decay of uranium and thorium. However, it also leads to significantly higher concentrations of lithium in the zircon lattice, which become positively correlated with trivalent yttrium and rare earth elements. Prior to such treatments, zircons typically contain lithium below detection limits (typically <0.55 μg g−1), unless correlated with lanthanum and aluminum (i.e., melt/mineral inclusion tracer elements). This suggests that lithium in zircon is primarily sequestered within inclusions, and is able to permeate the crystal lattice to couple with yttrium and rare earth elements during the thermal annealing procedure. This process occurs 2–3 orders of magnitude faster than diffusion experiments have previously determined, indicating that another diffusion mechanism may apply. A model is proposed, whereby: (i) charge compensation of stoichiometrically over-abundant trivalent cations under water-rich magmatic conditions is likely accomplished by hydrogen, given the incompatibility of lithium in zircon and the abundance of hydrogen. However, (ii) conditions that are high temperature and low pressure (characteristic of both thermal annealing and the syn-eruptive environment), drive silicate melt inclusions to exsolve water, generating a motive force for both hydrogen and lithium from inclusions to permeate the lattice in order to reestablish electrochemical equilibrium between the interior and exterior of the zircon. To test the pressure dependency of lithium migration in the zircon lattice, thermal annealing experiments were performed at 850 °C and 1 bar, 2 kbar and 6 kbar using zircons from the Fish Canyon Tuff. The experiments demonstrate that thermal annealing at 2 and 6 kbar inhibits lithium mobility, with zircons registering lithium concentrations below detection limits similar to controls. The experimental results suggest that lithium concentrations in zircon are vulnerable to rapid perturbation by decompression (concurrent with high temperatures), which further indicate that lithium-in-zircon diffusion data should be interpreted with caution.Publisher PDFPeer reviewe

    Uma sondagem via internet projetada para avaliar a vida diária dos idosos

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    O declínio da saúde física e do funcionamento cognitivo, em decorrência da idade, pode ter efeitos profundos na vida diária dos idosos, inclusive no desempenho de tarefas de autocuidado e na participação em atividades sociais. No entanto, pouco ainda se sabe sobre essa relação, devido à falta de medidas adequadas para uma avaliação diária dessa população. Este artigo apresenta um projeto piloto interdisciplinar que desenvolveu medidas diárias de saúde, funcionamento físico, atividades de autocuidado e atividades sociais entre  idosos. No estudo, 182 idosos (com idades entre 60 e 90 anos) participaram, através da internet, de uma breve (~15 minutos) pesquisa de base, e de avaliações diárias, durante sete dias consecutivos. As medidas incluídas nesse estudo, e suas estatísticas descritivas, são apresentadas neste trabalho. Na conclusão são discutidas suas implicações para pesquisas futuras, incluindo os desafios envolvidos no uso da internet para a coleta de dados de idosos

    Distinguishing the vegetation and soil component of &delta;13C variation in speleothem records from degassing and prior calcite precipitation effects

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    The carbon isotopic signature inherited from soil/epikarst processes may be modified by degassing and prior calcite precipitation (PCP) before its imprint on speleothem calcite. Despite laboratory demonstration of PCP effects on carbon isotopes and increasingly sophisticated models of the governing processes, to date, there has been limited effort to deconvolve the dual PCP and soil/epikarst components in measured speleothem isotopic time series. In this contribution, we explore the feasibility, advantages, and disadvantages of using trace element ratios and &delta;44Ca to remove the overprinting effect of PCP on measured &delta;13C to infer the temporal variations in the initial &delta;13C of dripwater. In 8 examined stalagmites, the most widely utilized PCP indicators Mg/Ca and &delta;44Ca covary as expected. However, Sr/Ca does not show consistent relationships with &delta;44Ca so PCP is not universally the dominant control on Sr/Ca. From &delta;44Ca and Mg/Ca, our calculation of PCP as fCa, fraction of initial Ca remaining at the deposition of the stalagmite layer, yields multiple viable solutions depending on the assumed &delta;44Ca fractionation factor and inferred variation in DMg. Uncertainty in the effective fractionation of &delta;13C during degassing and precipitation contributes to uncertainty in the absolute value of estimated initial &delta;13C. Nonetheless, the trends in initial &delta;13C are less sensitive to these uncertainties. In coeval stalagmites from the same cave spanning 94 to 82 ka interval, trends in calculated initial &delta;13C are more similar than those in measured &delta;13C, and reveal a common positive anomaly initial &delta;13C during a stadial cooling event. During deglaciations, the trend of greater respiration rates and higher soil CO2 is captured in the calculated initial &delta;13C, despite the tendency of higher interglacial dripwater situation to favor more extensive PCP.</p

    Third International Conference on Applications of Optics and Photonics

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    Organic semiconductor rubrene (C42H28) belongs to most preferred spintronic materials because of the high charge carrier mobility up to 40 cm(2)(V.s)(-1). However, the fabrication of a defect-free, polycrystalline rubrene for spintronic applications represents a difficult task. We report preparation and properties of rubrene thin films deposited by pulsed laser evaporation of solidified solutions. Samples of rubrene dissolved in aromatic solvents toluene, xylene, dichloromethane and 1,1-dichloroethane (0.23-1% wt) were cooled to temperatures in the range of 16.5-163 K and served as targets. The target ablation was provided by a pulsed 1064 nm or 266 nm laser. For films of thickness up to 100 nm deposited on Si, glass and ITO glass substrates, the Raman and AFM data show presence of the mixed crystalline and amorphous rubrene phases. Agglomerates of rubrene crystals are revealed by SEM observation too, and presence of oxide/peroxide (C42H28O2) in the films is concluded from matrix-assisted laser desorption/ionization time-offlight spectroscopic analysis
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