37,336 research outputs found

    Biology and Management of the American Shad and Status of the Fisheries, Atlantic Coast of the United States, 1960

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    This paper summarizes current information on the American shad, Alosa sapidissima, and describes the species and its fishery. Emphasis is placed on (1) life history of the fish, (2) condition of the fishery by State and water areas in 1960 compared to 1896 when the last comprehensive description was made, (3) factors responsible for decline in abundance, and (4) management measures. The shad fishery has changed little over the past three-quarters of a century, except in magnitude of yield. Types of shad-fishing gear have remained relatively unchanged, but many improvements have been made in fishing techniques, mostly to achieve economy. In 1896 the estimated catch was more than 50 million pounds. New Jersey ranked first in production with about 14 million pounds, and Virginia second with 11 million pounds. In 1960 the estimated catch was slightly more than 8 million pounds. Maryland ranked first in production with slightly more than 1.5 million pounds, Virginia second with slightly less than 1.4 million pounds, and North Carolina third with about 1.3 million pounds. Biological and economic factors blamed for the decline in shad abundance, such as physical changes in the environment, construction of dams, pollution, over-fishing, and natural cycles of abundance, are discussed. Also discussed are methods used for the rehabilitation and management of the fishery, such as artificial propagation, installation of fish-passage facilities at impoundments, and fishing regulations. With our present knowledge, we can manage individual shad populations; but, we probably cannot restore the shad to its former peak of abundance

    Initiation of Olefin Metathesis: Reaction of Deca-2,8-diene with Catalysts formed from Me_4Sn-WC1_6 and Me_3Al_2Cl_3-(Ph_3P)_2(NO)_2Cl_2Mo

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    The initial product of the metathesis of deca-2,8-diene with metathesis catalysts formed from either Me_4Sn–WCl_6 or Me_3Al_2Cl_3–(Ph_3P)_2(NO)_2Cl_2Mo is propene; labelling of the terminal groups of the diene and the alkylating agents gives a labelling pattern in the propene that is best explained in terms of generation of a carbene in the initiation step from the alkylating agent

    A Proposal for a Comprehensive Restructuring of the Public Information System

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    After more than ten years of legislative, judicial and bureaucratic tinkering, the public information system created by the Freedom of Information Act (FOIA) is still far from satisfactory. The present public information system has not been successful because its drafters lacked imagination and failed to do the basic work necessary to create a sound foundation for such a comprehensive program. They failed to analyze the realistic goals of a public information system; they ignored the ultimate goals of improved government performance; they misrepresented the system\u27s costs, both in monetary expense to taxpayers and in diminished government performance. They considered neither alternative techniques nor the problem of designing the public information system as an integral part of the total governmental structure. Actual open government for the benefit of the general populace will be possible only if the basic weaknesses of the present system are explored in depth. This Article is an appeal to Congress to undertake the careful analysis necessary to construct a workable, useful public information system

    Heat budget observations for the FIRE/SRB Wisconsin experiment region from October 9 through November 2, 1986

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    A map and concise tables are presented which show locations, pixel size, and heat budget products from the NOAA-9 satellite for the FIRE/SRB Wisconsin experiment region during the period 9 October through 2 November 1986. In addition to the operational standard products, a narrowband albedo parameter is calculated and presented based on values from AVHRR band 1. This parameter is useful in identifying and/or quantifying clouds on a global basis using a polar-stereographic grid system

    The Evolution of the American Real Estate Society

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    The American Real Estate Society (ARES) started with the need for real estate academics to increase their applied research and teaching skills and grew rapidly as research practitioners realized the benefits of working with academics in their field. From its humble beginnings, ARES has grown to be the largest organization of real estate researchers in the world and has spawned a number of new real estate societies on a number of continents. The history of the ARES approach to being innovative and inclusive to all real estate thought leaders is chronicled in this article by two authors who met at one of the early pre-ARES meetings and have been both real estate academics and practitioners in their careers.

    They (Don't) Care About Education: A Counternarrative on Black Male Students' Responses to Inequitable Schooling

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    Focus group interviews and systematic content analysis of 304 essays written by black male undergraduates refute the dominant message that black men do not care about education. On the contrary, these students aspire to earn doctoral degrees in education despite acute understanding that the education system is stacked against them. The analysis asks what compels that dedication

    The Volatility Trend of Protosolar and Terrestrial Elemental Abundances

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    We present new estimates of protosolar elemental abundances based on an improved combination of solar photospheric abundances and CI chondritic abundances. These new estimates indicate CI chondrites and solar abundances are consistent for 60 elements. We compare our new protosolar abundances with our recent estimates of bulk Earth composition (normalized to aluminium), thereby quantifying the devolatilization in going from the solar nebula to the formation of the Earth. The quantification yields a linear trend log(f)=αlog(TC)+β\log(f) = \alpha\log(T_C) + \beta, where ff is the Earth-to-Sun abundance ratio and TCT_C is the 50%\% condensation temperature of elements. The best fit coefficients are: α=3.676±0.142\alpha = 3.676\pm 0.142 and β=11.556±0.436\beta = -11.556\pm 0.436. The quantification of these parameters constrains models of devolatilization processes. For example, the coefficients α\alpha and β\beta determine a critical devolatilization temperature for the Earth TD(E)=1391±15T_{\mathrm{D}}(\mathrm{E}) = 1391 \pm 15 K. The terrestrial abundances of elements with TC<TD(E)T_{C} < T_{\mathrm{D}}(\mathrm{E}) are depleted compared with solar abundances, whereas the terrestrial abundances of elements with TC>TD(E)T_{C} > T_{\mathrm{D}}(\mathrm{E}) are indistinguishable from solar abundances. The terrestrial abundance of Hg (TCT_C = 252 K) appears anomalously high under the assumption that solar and CI chondrite Hg abundances are identical. To resolve this anomaly, we propose that CI chondrites have been depleted in Hg relative to the Sun by a factor of 13±713\pm7. We use the best-fit volatility trend to derive the fractional distribution of carbon and oxygen between volatile and refractory components (fvolf_\mathrm{vol}, freff_\mathrm{ref}). We find (0.91±0.080.91\pm 0.08, 0.09±0.080.09 \pm 0.08) for carbon and (0.80±0.040.80 \pm 0.04, 0.20±0.040.20 \pm 0.04) for oxygen.Comment: Accepted for publication in Icarus. 28 pages, 12 figures, 5 tables. Compared to v1, the results and conclusion are the same, while discussion of results and implications is expanded considerabl
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