9,281 research outputs found

    Changing Farm Structure and the Distribution of Farm Payments and Federal Crop Insurance

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    The distribution of commodity-related payments and Federal crop insurance indemnities to U.S. farmers has shifted to larger farms as more and more U.S. agricultural production is done on those farms. Since the operators of larger farms tend to have higher household incomes than other farm operators, commodity-related program payments and Federal crop insurance indemnities also have shifted to higher income households. By 2009, half of commodity-related program payments went to farms operated by households earning over 89,540,aquarterwenttofarmsoperatedbyhouseholdswithincomesgreaterthan89,540, a quarter went to farms operated by households with incomes greater than 209,000 and 10 percent went to farms operated by households with incomes of at least 425,000.Currentincomeeligibilitycapsandpaymentlimitsaffectfewfarmhouseholdsbecausemostofthemhaveincomesbelowtheincomecapsorreceivepaymentslessthanthepaymentlimits.Basedon2009AgriculturalResourceManagementSurvey(ARMS)data,recentproposalstolowerthoseincomecapsandpaymentlimitswouldstillaffectonlyasmallpercentageofU.S.farmhouseholds,becausetheirincomeswouldstillfallbelowtheproposedincomecapsandpaymentlimits.TotalGovernmentprogrampaymentstoU.S.farmswere425,000. Current income eligibility caps and payment limits affect few farm households because most of them have incomes below the income caps or receive payments less than the payment limits. Based on 2009 Agricultural Resource Management Survey (ARMS) data, recent proposals to lower those income caps and payment limits would still affect only a small percentage of U.S. farm households, because their incomes would still fall below the proposed income caps and payment limits. Total Government program payments to U.S. farms were 12.3 billion in 2009. Total Federal crop insurance indemnity payments were $5.2 billion in 2009.farm program payments, Federal crop insurance, Agricultural Resource Management Survey, structural change, income caps, payment limits., Agricultural and Food Policy, Agricultural Finance, Industrial Organization, Public Economics,

    Efficient and Robust Weighted Least-Squares Cell-Average Gradient Construction Methods for the Simulation of Scramjet Flows

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    The ability to solve the equations governing the hypersonic turbulent flow of a real gas on unstructured grids using a spatially-elliptic, 2nd-order accurate, cell-centered, finite-volume method has been recently implemented in the VULCAN-CFD code. The construction of cell-average gradients using a weighted linear least-squares method and the use of these gradients in the construction of the inviscid fluxes is the focus of this paper. A comparison of least-squares stencil construction methodologies is presented and approaches designed to minimize the number of cells used to augment/stabilize the least-squares stencil while preserving accuracy are explored. Due to our interest in hypersonic flow, a robust multidimensional cell-average gradient limiter procedure that is consistent with the stencil used to construct the cellaverage gradients is described. Canonical problems are computed to illustrate the challenges and investigate the accuracy, robustness and convergence behavior of the cell-average gradient methods on unstructured cell-centered finite-volume grids. Finally, thermally perfect, chemically frozen, Mach 7.8 turbulent flow of air through a scramjet engine flowpath is computed and compared with experimental data to demonstrate the robustness, accuracy and convergence behavior of the preferred gradient method for a realistic 3-D geometry on a non-hex-dominant grid

    Hopkins\u27 Theory of the Perception of Natural Beauty

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    Hubble Advanced Camera for Surveys Observations of the z=6.42 Quasar SDSS 1148+5251: A Leak in the Gunn-Peterson Trough

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    The Hubble Advanced Camera for Surveys has been used to obtain a narrow-band image of the weak emission peak seen at lambda=7205 A in the Gunn-Peterson Ly beta absorption trough of the highest redshift quasar, SDSS J1148+5251. The emission looks perfectly point-like; there is no evidence for the intervening galaxy that we previously suggested might be contaminating the quasar spectrum. We derive a more accurate astrometric position for the quasar in the two filters and see no indication of gravitational lensing. We conclude that the light in the Ly beta trough is leaking through two unusually transparent, overlapping windows in the IGM absorption, one in the Ly beta forest at z ~ 6 and one in the Ly alpha forest at z ~ 5. If there are significant optical depth variations on velocity scales small compared with our spectral resolution (~150 km/s), the Ly alpha trough becomes more transparent for a given Ly beta optical depth. Such variations can only strengthen our conclusion that the fraction of neutral hydrogen in the IGM increases dramatically at z>6. We argue that the transmission in the Ly beta trough is not only a more sensitive measure of the neutral fraction than is Ly alpha, it also provides a less biased estimator of the neutral hydrogen fraction than does the Ly alpha transmission.Comment: Submitted to the Astronomical Journa

    Probing the Ionization State of the Universe at z>6

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    We present high signal-to-noise ratio Keck ESI spectra of the two quasars known to have Gunn-Peterson absorption troughs, SDSS J1030+0524 (z=6.28) and SDSS J1148+5251 (z=6.37). The Ly alpha and Ly beta troughs for SDSS J1030+0524 are very black and show no evidence for any emission over a redshift interval of ~0.2 starting at z=6. On the other hand, SDSS J1148+5251 shows a number of emission peaks in the Ly beta Gunn-Peterson trough along with a single weak peak in the Ly alpha trough. The Ly alpha emission has corresponding Ly beta emission, suggesting that it is indeed a region of lower optical depth in the intergalactic medium at z=6.08. The stronger Ly beta peaks in the spectrum of SDSS J1148+5251 could conceivably also be the result of "leaks" in the IGM, but we suggest that they are instead Ly alpha emission from an intervening galaxy at z=4.9. This hypothesis gains credence from a strong complex of C IV absorption at the same redshift and from the detection of continuum emission in the Ly alpha trough at the expected brightness. If this proposal is correct, the quasar light has probably been magnified through gravitational lensing by the intervening galaxy. The Stromgren sphere observed in the absorption spectrum of SDSS J1148+5251 is significantly smaller than expected based on its brightness, which is consistent with the hypothesis that the quasar is lensed. If our argument for lensing is correct, the optical depths derived from the troughs of SDSS J1148+5251 are only lower limits (albeit still quite strong, with tau(LyA)>16 inferred from the Ly beta trough.) The Ly beta absorption trough of SDSS J1030+0524 gives the single best measurement of the IGM transmission at z>6, with an inferred optical depth tau(LyA)>22.Comment: To appear in July 2003 AJ, 34 pages, 11 figures; minor changes/typos fixe

    Tectonics of the western Gulf of Oman

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    Also published as: Journal of Geophysical Research 84 (1979): 3479-3489The Oman line, running northward from the Strait of Hormuz separates a continent‐continent plate boundary to the northwest (Persian Gulf region) from an ocean‐continent plate boundary to the southeast (Gulf of Oman region). A large basement ridge detected on multichannel seismic reflection and gravity profiles to the west of the Oman line is probably a subsurface continuation of the Musandam peninsula beneath the Strait of Hormuz. Collision and underthrusting beneath Iran of the Arabian plate on which this ridge lies has caused many of the large earthquakes that have occurred in this region. Convergence between the oceanic crust of the Arabian plate beneath the Gulf of Oman and the continental Eurasian plate beneath Iran to the north is accommodated by northward dipping subduction. A deformed sediment prism which forms the offshore Makran continental margin and which extends onto land in the Iranian Makran has accumulated above the descending plate. In the western part of the Gulf of Oman, continued convergence has brought the opposing continental margin of Oman into contact with the Makran continental margin. This is an example of the initial stages of a continent‐continent type collision. A model of imbricate thrusting is proposed to explain the development of the fold ridges and basins on the Makran continental margin. Sediments from the subducting plate are buckled and incorporated into the edge of the Makran continental margin in deformed wedges and subsequently uplifted along major faults that penetrate the accretionary prism further to the north.Prepared for the Office of Naval Research under Contract N00014-74-C-0262; NR 083-004 and for the National Science Foundation under Grant 76-10417

    Building Understanding and Knowledge: A Case Study in Stakeholder Orientation

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    Accumulation of knowledge and understanding is the goal of scientific research. Such accumulation requires that areas of interest be approached with a theoretical base and replicable processes and methodologies. Recent reviews of stakeholder theory (Laplume et al, 2008; Mainardes et al., 2011) have delineated a number of issues in this area of study. In particular, they identify that if this area of research is to move toward deeper understanding, then areas of interest need to be studied in different contexts and with validated measurement instruments. This paper provides an example of a replication and methods development of stakeholder orientation from the manager's perspective in small firms

    Missouri bobwhite quail habitat appraisal guide : assessing your farm's potential for bobwhites (2008)

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    New 1/05 ; Revised 4/08/XM

    MicroR159 regulation of most conserved targets in Arabidopsis has negligible phenotypic effects

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    BACKGROUND A current challenge of microRNA (miRNA) research is the identification of biologically relevant miRNA:target gene relationships. In plants, high miRNA:target gene complementarity has enabled accurate target predictions, and slicing of target mRNAs has facilitated target validation through rapid amplification of 5' cDNA ends (5'-RACE) analysis. Together, these approaches have identified more than 20 targets potentially regulated by the deeply conserved miR159 family in Arabidopsis, including eight MYB genes with highly conserved miR159 target sites. However, genetic analysis has revealed the functional specificity of the major family members, miR159a and miR159b is limited to only two targets, MYB33 and MYB65. Here, we examine the functional role of miR159 regulation for the other potential MYB target genes. RESULTS For these target genes, functional analysis failed to identify miR159 regulation that resulted in any major phenotypic impact, either at the morphological or molecular level. This appears to be mainly due to the quiescent nature of the remaining family member, MIR159c. Although its expression overlaps in a temporal and spatial cell-specific manner with a subset of these targets in anthers, the abundance of miR159c is extremely low and concomitantly a mir159c mutant displays no anther defects. Examination of potential miR159c targets with conserved miR159 binding sites found neither their spatial or temporal expression domains appeared miR159 regulated, despite the detection of miR159-guided cleavage products by 5'-RACE. Moreover, expression of a miR159-resistant target (mMYB101) resulted predominantly in plants that are indistinguishable from wild type. Plants that displayed altered morphological phenotypes were found to be ectopically expressing the mMYB101 transgene, and hence were misrepresentative of the in vivo functional role of miR159. CONCLUSIONS This study presents a novel explanation for a paradox common to plant and animal miRNA systems, where among many potential miRNA-target relationships usually only a few appear physiologically relevant. The identification of a quiescent miR159c:target gene regulatory module in anthers provides a likely rationale for the presence of conserved miR159 binding sites in many targets for which miR159 regulation has no obvious functional role. Remnants from the demise of such modules may lead to an overestimation of miRNA regulatory complexity when investigated using bioinformatic, 5'-RACE or transgenic approaches.RSA was funded by an ANU postgraduate scholarship and by a CSIRO Emerging Science Initiative. JL is the recipient of an ANU international student postgraduate scholarship. This research was supported by an Australian Research Council grant DP0773270
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