561 research outputs found

    Characteristics and Risk Management Needs of Limited-Resource and Socially Disadvantaged Farmers

    Get PDF
    Small U.S. farms and those run by socially disadvantaged minority operators tend not to purchase insurance or to participate in insurance-type programs operated by USDA. This report traces the lack of use of such risk management measures to several characteristics of such farmers, who include females, blacks, American Indians, Asian/Pacific Islanders, and operators of Spanish origin. These farmers tend, more than the typical U.S. farm, to raise livestock rather than crops, and there are no government-sponsored insurance-type programs for livestock.risk management, crop insurance, limited-resource farmers, limited-opportunity farmers, small farms, socially disadvantaged farmers, Farm Management, Risk and Uncertainty,

    Policy Implications of Crop Yield and Revenue Variability at Differing Levels of Disaggregation

    Get PDF
    Revenue variability at different levels of aggregation has been the focus of several proposals to reform U.S. commodity programs with the 2007 farm bill. In this paper, we estimate revenue variabilityyear-to-year deviations from expected revenuefor corn, soybeans, and cotton at four levels of aggregation: national, state, county and farm. We examine the factors that cause revenue variability and how differences across crops and regions would affect producers risks. We find that national-level revenue variability is nearly double national-level yield variability. Spatial disaggregation increases price and yield variability, but yield variability increases more rapidly than price and revenue variability. A hypothetical national-level revenue program would reduce risk at the average farm-level by slightly more than 8 percent for corn, about 7 percent for soybeans and about 21 percent for cotton. If one integrates farm-level revenue coverage with the national-level program the percent risk reduction more than doubles for both corn and soybeans. Although the increase in risk reduction between the simple national and the integrated program is proportionately less for cotton, the total risk reduction for cotton is the greatest among the three crops.Agricultural and Food Policy,

    An Economic Assessment of the 1999 Drought: Agricultural Impacts Are Severe Locally, but Limited Nationally

    Get PDF
    While the 1999 drought has had severe financial impacts on agricultural producers in the drought regions, its impact on U.S. agricultural production has been limited. The drought will reduce commodity receipts relative to 1998 by an estimated 1.29billion.Estimatedfarmnetincomelosses,includingexpectedyieldlosses,increasesinexpenses,andinsuranceindemnities,willtotal1.29 billion. Estimated farm net income losses, including expected yield losses, increases in expenses, and insurance indemnities, will total 1.35 billion, about 3 percent of expected 1999 U.S. net farm income. Drought impacts in areas of the Northeast designated as extreme and severe drought are expected to reduce farmers' net income by nearly $840 million. The regions affected, the crops grown in those regions, the increased use of irrigation, and crop insurance coverage limited the drought's impacts on agriculture nationally. Drought also affects the rural population by reducing water supplies available for human and livestock consumption.Agricultural Finance, Farm Management,

    Characterizing toxic emissions from a coal-fired power plant demonstrating the AFGD ICCT Project and a plant utilizing a dry scrubber/baghouse system: Bailly Station Units 7 and 8 and AFGD ICCT Project. Final report. Final report

    Full text link
    This report describes results of assessment of the risk of emissions of hazardous air pollutants at one of the electric power stations, Bailly Station, which is also the site of a Clean Coal Technology project demonstrating the Pure Air Advanced Flue Gas Desulfurization process (wet limestone). This station represents the configuration of no NO{sub x} reduction, particulate control with electrostatic precipitators, and SO{sub 2} control with a wet scrubber. The test was conducted September 3--6, 1993. Sixteen trace metals were determined along with 5 major metals. Other inorganic substances and organic compounds were also determined

    Effects of Acute Stress on Aircrew Performance: Literature Review and Analysis of Operational Aspects

    Get PDF
    Situational stress can adversely affect the cognition and skilled performance of pilots, as well as experts in other domains. Emergencies and other threatening situations require pilots to execute infrequently practiced procedures correctly and to use their skills and judgment to select an appropriate course of action, often under high workload, time pressure, and ambiguous indications, all of which can be stressful. Our current study, consited of three parts, starting with a critical review of the research literature on the effects of stress on skilled performance, going back to World War II and continuing to recent and more sophisticated studies of the cognitive effects of anxiety. In the second part we analyzed the specific ways stress may have impaired the performance of airline crews in twelve major accidents, selected for diversity of the situations the crews encountered. The third part examined the operational significance and practical implications of the findings from the first two parts, suggested specific ways to reduce the harmful effects of stress on flight crews, and identified aspects requiring further research. Even thought this study focused on flight crews, the findings apply to the effects of stress on the skilled performance of experts in almost any domain

    Thermodynamically accurate modeling of the catalytic cycle of photosynthetic oxygen evolution: A mathematical solution to asymmetric Markov chains

    Get PDF
    AbstractForty-three years ago, Kok and coworkers introduced a phenomenological model describing period-four oscillations in O2 flash yields during photosynthetic water oxidation (WOC), which had been first reported by Joliot and coworkers. The original two-parameter Kok model was subsequently extended in its level of complexity to better simulate diverse data sets, including intact cells and isolated PSII-WOCs, but at the expense of introducing physically unrealistic assumptions necessary to enable numerical solutions. To date, analytical solutions have been found only for symmetric Kok models (inefficiencies are equally probable for all intermediates, called “S-states”). However, it is widely accepted that S-state reaction steps are not identical and some are not reversible (by thermodynamic restraints) thereby causing asymmetric cycles. We have developed a mathematically more rigorous foundation that eliminates unphysical assumptions known to be in conflict with experiments and adopts a new experimental constraint on solutions. This new algorithm termed STEAMM for S-state Transition Eigenvalues of Asymmetric Markov Models enables solutions to models having fewer adjustable parameters and uses automated fitting to experimental data sets, yielding higher accuracy and precision than the classic Kok or extended Kok models. This new tool provides a general mathematical framework for analyzing damped oscillations arising from any cycle period using any appropriate Markov model, regardless of symmetry. We illustrate applications of STEAMM that better describe the intrinsic inefficiencies for photon-to-charge conversion within PSII-WOCs that are responsible for damped period-four and period-two oscillations of flash O2 yields across diverse species, while using simpler Markov models free from unrealistic assumptions

    Calculation of thermal parameters of SiGe microbolometers

    Full text link
    The thermal parameters of a SiGe microbolometer were calculated using numerical modeling. The calculated thermal conduction and thermal response time are in good agreement with the values found experimentally and range between 2x107^-7 and 7x108^-8 W/K and 1.5 and 4.5 ms, respectively. High sensitivity of microbolometer is achieved due to optimization of the thermal response time and thermal conduction by fitting the geometry of supporting heat-removing legs or by selection of a suitable material providing boundary thermal resistance higher than 8x103^-3 cm2^2K/W at the SiGe interface.Comment: 11 pages, 6 figure

    Economic Impact of Gulf of Mexico Ecosystem Goods and Services and Integration Into Restoration Decision-Making

    Get PDF
    Sustainability of natural resources requires balancing exploitation and conservation, enabled by management based on the best available scientific and economic information. Valuation of ecosystem goods and services is an important tool for prioritizing restoration efforts, recognizing the economic importance of conserving natural capital, and raising public awareness about the contribution of healthy ecosystems to social welfare, now and for future generations. The Deepwater Horizon oil spill (DHOS) in 2010 was a Gulf of Mexico ecological and economic disaster adding to decades-long degradation of the region’s coastal and marine environment. In 2010, revenues from provisioning ecosystem goods and services generated by the five U.S. states bordering the Gulf of Mexico contributed over 2trillionperyeartothenationsgrossdomesticproduct,including2 trillion per year to the nation’s gross domestic product, including 660 billion from the coastal county revenues and 110billionfromoceanrevenues.MexicoandCubacontributeatleastanother110 billion from ocean revenues. Mexico and Cuba contribute at least another 40 billion per year from their Gulf coastal and ocean economies. Total economic value of Gulf ecosystem goods and services also requires valuation of nonmarket regulating, cultural, and supporting services, which are far more difficult to assess, but add billions more dollars per year. In light of this total economic value and trends in ecosystem stressors, new investment is necessary to ensure completeness, accuracy, and availability of Gulf economic impact data. Civil and criminal settlements related to the DHOS provide unprecedented opportunities for improving integration of ecosystem goods and services into decisions that affect Gulf restoration and sustainability. This paper highlights the economic contributions of Gulf ecosystem goods and services to the nation’s welfare, and recommends actions and investments required to ensure that they are valued, and integrated into decision-making
    corecore