9,849 research outputs found

    Provisions and Potential Impacts of the Average Crop Revenue Election (ACRE) Program

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    Replaced with revised version of paper 11/24/08.Agricultural and Food Policy, Crop Production/Industries,

    "Maximizing Conservation and In-Kind Cost Share: Applying Goal Programming to Forest Protection"

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    This research evaluates the potential gains in benefits from using Goal Programming to preserve forestland. Two- and three-dimensional Goal Programming models are developed and applied to data from applicants to the U.S. Forest Service’s Forest Legacy Program, the largest forest protection program in the United States. Results suggest that not only do these model yield substantial increases in benefits, but by being able to account for both environmental benefits and in-kind partner cost share, Goal Programming may be flexible enough to facilitate adoption by program managers needing to account for both ecological and political factors.Goal programming, multi-objective programming, conservation optimization, forest conservation, environmental services, in-kind cost sharing, matching grants

    Estimates of Minnesota Farm-Level Crop Commodity Payments under New House Framework

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    The objective of this study is to compare commodity payments under current Federal farm policy with the previous Senate and Administration proposals and the recently released “2008 Farm Bill Conference: House Agriculture Committee-Developed Concept for a Farm Bill Spending Framework.” Projections of crop revenue and government payments are made using historical yield data for each example farm, the county, and the nation; historical price data; and statistical distributions and relationships of these yields and prices. Using 2007 FAPRI price projections (which are closer to the prices expected in the next few years when a new farm bill will be in force), expected Total Government Payments (TGP) are almost entirely attributed to the fixed direct payments under all these proposals. Since commodity prices are so far above their “target levels” the possibility of a counter cyclical price or revenue payment or a loan deficiency payment is highly unlikely. TGP under the alternative policies follows a similar pattern on the example corn and soybean farms and a slightly different but fairly consistent pattern for the example wheat and soybean farms. For the corn and soybean example farms in southern Minnesota, the HB-RCCP and USDA proposals generate very similar levels of TGPs compared to current policy. HB-RCCP provides a slightly higher expected TGP than CP for all example farms except for one and higher TGP than USDA for all farms. ACR is estimated to provide lower TGP for all example corn and soybean farms. For the example wheat and soybean farms in northwest Minnesota, the results are mixed. Compared to the other three proposals, ACR provides higher TGP for 2 of the 6 example farms. Each of the proposals does reduce risk as measured by CV. We note ACR is not quite as efficient at risk reduction except for two wheat/soybean farms in northwest Minnesota.Farm Management,

    Risk Analysis of Organic Cropping Systems in Minnesota

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    When all strategies received conventional market prices, 4-year cropping sequences had greater net returns than 2-year sequences, and the organic input, 4-year strategy had the highest net return. Adding 50% of the estimated organic premium, the 4-year, organic strategy dominated all low- and high-purchased input strategies.Crop Production/Industries, Risk and Uncertainty,

    Causal Quantum Theory and the Collapse Locality Loophole

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    Causal quantum theory is an umbrella term for ordinary quantum theory modified by two hypotheses: state vector reduction is a well-defined process, and strict local causality applies. The first of these holds in some versions of Copenhagen quantum theory and need not necessarily imply practically testable deviations from ordinary quantum theory. The second implies that measurement events which are spacelike separated have no non-local correlations. To test this prediction, which sharply differs from standard quantum theory, requires a precise theory of state vector reduction. Formally speaking, any precise version of causal quantum theory defines a local hidden variable theory. However, causal quantum theory is most naturally seen as a variant of standard quantum theory. For that reason it seems a more serious rival to standard quantum theory than local hidden variable models relying on the locality or detector efficiency loopholes. Some plausible versions of causal quantum theory are not refuted by any Bell experiments to date, nor is it obvious that they are inconsistent with other experiments. They evade refutation via a neglected loophole in Bell experiments -- the {\it collapse locality loophole} -- which exists because of the possible time lag between a particle entering a measuring device and a collapse taking place. Fairly definitive tests of causal versus standard quantum theory could be made by observing entangled particles separated by 0.1\approx 0.1 light seconds.Comment: Discussion expanded; typos corrected; references adde

    Social Support and the Perception of Geographical Slant.

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    The visual perception of geographical slant is influenced by physiological resources, such as physical fitness, age, and being physically refreshed. In two studies we tested whether a psychosocial resource, social support, can also affect the visual perception of slants. Participants accompanied by a friend estimated a hill to be less steep when compared to participants who were alone (Study 1). Similarly, participants who thought of a supportive friend during an imagery task saw a hill as less steep than participants who either thought of a neutral person or a disliked person (Study 2). In both studies, the effects of social relationships on visual perception appear to be mediated by relationship quality (i.e., relationship duration, interpersonal closeness, warmth). Artifacts such as mood, social desirability, and social facilitation did not account for these effects. This research demonstrates that an interpersonal phenomenon, social support, can influence visual perception

    Mantle heterogeneity during the formation of the North Atlantic Igneous Province: Constraints from trace element and Sr-Nd-Os-O isotope systematics of Baffin Island picrites

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    Sr-Nd-Os-O isotope and major and trace element data from ~62 Ma picrites from Baffin Island constrain the composition of mantle sources sampled at the inception of North Atlantic Igneous Province (NAIP) magmatism. We recognize two compositional types. Depleted (N-type) lavas have low 87Sr/86Sri (0.702990–0.703060) and 187Os/188Osi (0.1220–0.1247) and high 143Nd/144Ndi (0.512989–0.512999) and are depleted in incompatible elements relative to primitive mantle. Enriched (E-type) lavas have higher 87Sr/86Sri (0.703306–0.703851) and 187Os/188Osi (0.1261–0.1303), lower 143Nd/144Ndi (0.512825–0.512906), and incompatible element concentrations similar to, or more enriched than, primitive mantle. There is also a subtle difference in oxygen isotope composition; E-type lavas are marginally lower in δ18Oolivine value (5.16–4.84‰) than N-type lavas (5.15–5.22‰). Chemical and isotopic variations between E- and N-type lavas are inconsistent with assimilation of crust and/or subcontinental lithospheric mantle and appear to instead reflect mixing between melts derived from two distinct mantle sources. Strontium-Nd-O isotope compositions and incompatible trace element abundances of N-type lavas suggest these are largely derived from the depleted upper mantle. The 187Os/188Osi ratios of N-type lavas can also be explained by such a model but require that the depleted upper mantle had γOs of approximately −5 to −7 at 62 Ma. This range overlaps the lowest γOs values measured in abyssal peridotites. Baffin Island lava compositions are also permissive of a model involving recharging of depleted upper mantle with 3He-rich material from the lower mantle (Stuart et al., Nature, 424, 57–59, 2003), with the proviso that recharge had no recognizable effect on the lithophile trace element and Sr-Nd-Os-O isotope composition. The origin of the enriched mantle component sampled by Baffin Island lavas is less clear but may be metasomatized and high-temperature-altered recycled oceanic lithosphere transported within the proto Iceland plume. Differences between Baffin Island lavas and modern Icelandic basalts suggest that a range of enriched and depleted mantle sources have been tapped since the inception of magmatism in the province. Similarities between Baffin Island lavas erupted and those of similar age from East and West Greenland also suggest that the enriched component in Baffin Island lavas may have been sampled by lavas erupted over a wide geographic range
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