95 research outputs found

    Economic Contribution of the Agricultural Sector to the Arkansas Economy in 2010

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    This report is the seventh in a series of reports examining agriculture’s economic contribution on the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economic Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and Minnesota IMPLAN Group, Inc. (MIG), the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2010. Gross Domestic Product (GDP) by State information for Arkansas in 2010 was compared with those of other states in the Southeast U.S. to give a measure of the relative importance of agriculture in Arkansas.2 The total economic contribution of agriculture (direct, indirect, and induced effects) on value added, employment, and labor income was estimated with the Impact Analysis for Planning System (IMPLAN). The economic contributions of agricultural production and processing were estimated for agriculture as a whole and also separately for the Crops Sector, the Animal Agriculture Sector, and the Forestry Sector

    Economic Contribution of the Agricultural Sector to the Arkansas Economy in 2009

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    This report is the sixth in a series of reports examining agriculture’s economic contribution on the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economic Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and Minnesota IMPLAN Group, Inc. (MIG), the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2009. Gross Domestic Product (GDP) by State information for Arkansas in 2009 was compared with those of other states in the southeast U.S. to give a measure of the relative importance of agriculture in Arkansas.2 The total economic contribution of agriculture (direct, indirect, and induced effects) on value added, employment, and labor income was estimated by employing the Impact Analysis for Planning System (IMPLAN). The economic contributions of agricultural production and processing were estimated for agriculture as a whole and also separately for the Crops Sector, the Animal Agriculture Sector, and the Forestry Sector

    Some Analyses of Twentieth Century Landing Statistics of Marine Shrimp of the South Atlantic and Gulf States of the United States

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    There is a strong correlation between the total catch of white and brown shrimp with dockside prices on the United States Gulf Coast since 1902, but there is no significant correlation between South Atlantic production and prices, probably because the South Atlantic shrimp stocks have been over-fished since the 1920s. There is no negative or positive correlation between the catch statistics of brown and white shrimp of the United States, and these species seem to be weakly competitive, if at all. There is a significant correlation between the annual production of South Atlantic and Gulf white shrimp, but there is none between South Atlantic and Gulf brown shrimp, possibly because the brown shrimp live generally in deeper water and are not so much influenced by short term variations in climatic conditions as the white shrimp are in shallow water. In furtherance of this idea, there is some indication that the brown shrimp production is less variable than the white shrimp production

    Some observations on arkshell clams, Noetia ponderosa and Anadara ovalis, and implications for fisheries management

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    Two species of arkshell or blood clams, Noetia ponderosa (ponderous ark) and Anadara ovalis (blood ark), have been harvested by watermen on the Eastern shore in Virginia since 1991. There is little information on the life history of these species in Virginia waters. The intensive harvesting of blood clams and paucity of data on important factors such as distribution, densities, growth rates, and size-age relationships present a problem for management of the fishery. The primary purpose of this study is to provide some basic information on blood clams for management of the fishery. We focused on age-size relationships and growth rates of clams. Some data were also collected on densities of blood clams and size-frequency distributions in fisheries and non-fisheries samples, as well as some morphometric data

    A study of the arkshell clams, Noetia ponderosa (Say 1822) and Anadara ovalis (Bruguière 1789), in the oceanside lagoons and tidal creeks of Virginia

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    Two species of arkshell (\u27\u27blood\u27\u27) clams. Noelia ponderosa and Anadara ova/is. have recently been targeted by watermen on the eastern shore of Virginia for sale to both East and West Coast markets in the United States. Until 1991. fishermen caught both species in the harvest of oysters and hard clams, and discarded them as bycatch with little value. Very little is known about either species of blood clam. and preliminary data from a pilot study in 1993 indicated that they were being over-fished. We conducted a survey in September 1994 in the oceanside lagoon system along the eastern shore of Accomac and Nonhampton Counties, Virginia. and collected data on density. abundance. habitat preference. age-size and morphometric relationships. and mortality rates for both species of blood clams. as well as some ancillary data on the hard clam, Mercenaria mercenaria. The study provides baseline data for establishing management practices and regulations for the blood clam fishery. The total estimated abundance in the study area was about 16 million N. ponderosa and 6.4 mi llion A. ova/is. Of the clams taken in commercial catches on the oceanside of the eastern shore, M. mercenaria constitutes about 84%, N. ponderosa 15%, and A. ova/is I%. in our field survey, M. mercenaria was the most abundant species (72% of the total catch), followed by N. ponderosa ( 17%) and A. ova/is ( 11 %). Densities for blood clams averaged 0.35 clams m-2, or 3,500 clams per hectare. and were highest in shell and shell/mud substrate (I. I and 1.2 clams m- 2 • respectively). Growth studies and age-size data show that A. ova/is grows about twice as fast as N. ponderosa and that market-size N. ponderosa (about 56 mm in shell height) may be 8+ years old. We also present information on mortality rates and morphometric relationships for both species of blood clams, and recommendations for maintaining and enhancing the fishery

    Economic Contribution of the Agricultural Sector to the Arkansas Economy in 2008

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    This report is the fifth in a series of reports examining agriculture’s economic contribution to the Arkansas economy. Utilizing data from the United States Bureau of Economic Analysis (BEA), USDA Economics Research Service (ERS), USDA National Agricultural Statistics Service (NASS), and Minnesota IMPLAN Group, Inc. (MIG), the economic contribution of agriculture on the Arkansas economy was estimated for the most recent year available, 2008. Gross Domestic Product (GDP) by State information for Arkansas was compared with those of other states in the southeast U.S. to give a measure of the relative importance of agriculture in Arkansas.2 The total economic contribution of agriculture (direct, indirect, and induced effects) on value added, employment, and labor income was estimated by employing the Impact Analysis for Planning System (IMPLAN). The economic contributions of agricultural production and processing were estimated for agriculture as a whole and also separately for the Crops Sector, the Animal Agriculture Sector, and the Forestry Secto

    Hydrogen bonded complexes between nitrogen dioxide, nitric acid, nitrous acid and water with SiH3OH and Si(OH)4

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    The inter-conversion of nitrogen oxides and oxy acids on silica surfaces is of major atmospheric importance. As a preliminary step towards rationalising experimental observations, and understanding the mechanisms behind such reactions we have looked at the binding energies of NO2, N2O4, HNO3, HONO and H2O with simple proxies of a silica surface, namely SiH3OH and Si(OH)4 units. The geometries of these molecular clusters were optimised at both HF/6-311+G(d) and B3LYP/6-311+G(d) level of theory. The SCF energies of the species were determined at the HF/6-311++G(3df,2pd) and B3LYP/6-311++G(3df,2pd) level. The values indicate that nitric acid is by far the most strongly bound species, in agreement with experimental observations. It was also found that the dimer N2O4 is significantly more strongly bound to the Si(OH)4 and SiH3OH units than NO2 itself. The vibrational frequencies calculated for the hydrogen-bonded complexes are compared to the experimentally observed frequencies of the adsorbed species where possible

    Charge Violation and Alice Behavior in Global and Textured Strings

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    Spontaneous breaking of global symmetries can produce ``Alice'' strings: line defects which make unbroken symmetries multivalued, induce apparent charge violation via Aharonov-Bohm interactions, and form point defects when twisted into loops. We demonstrate this behavior for both divergent and textured global Alice strings. Both adiabatically scatter charged particles via effective Wilson lines. For textured Alice strings, such Wilson lines occur at all radii, and are multivalued only inside the string. This produces measurable effects, including path-dependent charge violation.Comment: 32 pages, 2 epsfigs, Revte

    Topologically Alice Strings and Monopoles

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    Symmetry breaking can produce ``Alice'' strings, which alter scattered charges and carry monopole number and charge when twisted into loops. Alice behavior arises algebraically, when strings obstruct unbroken symmetries -- a fragile criterion. We give a topological criterion, compelling Alice behavior or deforming it away. Our criterion, that \pi_o(H) acts nontrivially on \pi_1(H), links topologically Alice strings to topological monopoles. We twist topologically Alice loops to form monopoles. We show that Alice strings of condensed matter systems (nematic liquid crystals, helium 3A, and related non-chiral Bose condensates and amorphous chiral superconductors) are topologically Alice, and support fundamental monopole charge when twisted into loops. Thus they might be observed indirectly, not as strings, but as loop-like point defects. We describe other models, showing Alice strings failing our topological criterion; and twisted Alice loops supporting deposited, but not fundamental, monopole number.Comment: 2 figures; this paper consolidates preprints hep-th/0304161 and hep-th/0304162, to appear in Phys. Rev.

    Estimating Error in Using Ambient PM2.5 Concentrations as Proxies for Personal Exposures: A Review

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    Several methods have been used to account for measurement error inherent in using ambient concentration of particulate matter < 2.5 μm/m3 (PM2.5) as a proxy for personal exposure. Such methods usually rely on the estimated correlation between ambient and personal PM2.5 concentrations (r). These studies have not been systematically and quantitatively assessed for publication bias or heterogeneity
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