464 research outputs found

    On farm conservation of rice biodiversity in Nepal: a simultaneous estimation approach

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    "This paper presents an empirical case study about farmer management of rice genetic resources in two communities of Nepal, drawing on interdisciplinary, participatory research that involved farmers, rice geneticists, and social scientists. The decision-making process of farm households is modeled and estimated in order to provide information for the design of community-based conservation programs. A bivariate model with sample selection treats the simultaneous process of whether farmers decide to plant landraces or modern varieties, and whether the landraces they choose to plant constitute genetic diversity of interest for future crop improvement. Findings show that the two landrace choices are affected by different social and economic factors. The estimation procedure demonstrates that in certain cases, however, the decision processes are interrelated. Policies to promote the conservation of local rice diversity will need to take both processes into account. Fitted equations are then used to compare the likelihood that households targeted for conservation according to one set of conservation criteria also meet other conservation criteria. Households most likely to plant landraces identified as important for crop improvement also grow richer, more spatially diverse rice varieties. In these communities, few policy trade-offs would result from employing one set of criteria instead of the other." Authors' AbstractLandraces, Crop diversity,

    Case Study Hydrologic Effects of Size and Location of Fields Converted from Drained Pine Forest to Agricultural Cropland

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    Abstract: Hydrological effects of land-use change are of great concern to ecohydrologists and watershed managers, especially in the Atlantic coastal plain of the southeastern United States. The concern is attributable to rapid population growth and the resulting pressure to develop forested lands. Many researchers have studied these effects in various scales, with varying results. An extended watershed-scale forest hydrologic model, calibrated with 1996–2000 data, was used to evaluate long-term hydrologic effects of conversion to agriculture (corn–wheat–soybean cropland) of a 29.5-km2 intensively managed pine-forested watershed in Washington County in eastern North Carolina. Fifty years of weather data (1951–2000) from a nearby weather station were used for simulating hydrology to evaluate effects on outflows, evapotranspiration, and water table depth compared with the baseline scenario. Other simulation scenarios were created for each of five different percentages (10, 25, 50, 75, and 100%) of land-use conversion occurring at upstream and downstream locations in the pine-forest watershed. Simulations revealed that increased mean annual outflow was significant (α 0.05) only for 100 % conversion from forest (261 mm) to agricultural crop (326 mm), primarily attributed to a reduction in evapotranspiration. Although high flow rates>5 mm day−1 increased from 2.3 to 2.6 % (downstream) and 2.6 to 4.2 % (upstream) for 25 to 50 % conversion, the frequency was higher for the upstream location than the downstream. These results were attributed to a substantial decrease in soil hydraulic conductivity of one of the dominant soils in the upstream location, which is expected after land-use conversion to agriculture. As a result, predicted subsurface drainage decreased, and surface runoff increased as soil hydraulic conductivity decreased for the soil upstream. These results indicate tha

    Four Flats Poster

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    Poster for a Four Flats reunion concerts at Porland Civic Auditorium, Oregon. 1 page, black and white.https://digitalcommons.georgefox.edu/fourflats_papers/1014/thumbnail.jp

    Predominance of Ancestral Lineages of Mycobacterium tuberculosis in India

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    Molecular epidemiologic findings suggest an ancient focus of TB

    Physical-vapor-deposited metal oxide thin films for pH sensing applications: Last decade of research progress

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    In the last several decades, metal oxide thin films have attracted significant attention for the development of various existing and emerging technological applications, including pH sensors. The mandate for consistent and precise pH sensing techniques has been increasing across various fields, including environmental monitoring, biotechnology, food and agricultural industries, and medical diagnostics. Metal oxide thin films grown using physical vapor deposition (PVD) with precise control over film thickness, composition, and morphology are beneficial for pH sensing applications such as enhancing pH sensitivity and stability, quicker response, repeatability, and compatibility with miniaturization. Various PVD techniques, including sputtering, evaporation, and ion beam deposition, used to fabricate thin films for tailoring materials’ properties for the advanced design and development of high-performing pH sensors, have been explored worldwide by many research groups. In addition, various thin film materials have also been investigated, including metal oxides, nitrides, and nanostructured films, to make very robust pH sensing electrodes with higher pH sensing performance. The development of novel materials and structures has enabled higher sensitivity, improved selectivity, and enhanced durability in harsh pH environments. The last decade has witnessed significant advancements in PVD thin films for pH sensing applications. The combination of precise film deposition techniques, novel materials, and surface functionalization strategies has led to improved pH sensing performance, making PVD thin films a promising choice for future pH sensing technologies

    In search of a theory of supercooled liquids

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    Despite the absence of consensus on a theory of the transition from supercooled liquids to glasses, the experimental observations suggest that a detail-independent theory should exist.Comment: Commentary. 3 pages 2 figure
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