54 research outputs found

    Variation in ruminant preference for alfalfa hays cut at sunup and sundown

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    Diurnal variation in the concentration of total nonstructural carbohydrates (TNC) occurs in plants as a result of photosynthesis. Ruminants have been shown to prefer tall fescue (Festuca arundinacea Schreber) hays cut in the afternoon but the effect of morning vs. evening cutting had not been tested in legumes. To test for diurnal variation in preference for alfalfa (Medicago sativa L.), we harvested six times in the midbud stage. Harvests were paired so that each time a cutting of alfalfa was made at sundown (PM) another was made the next morning at sunup (AM). We harvested in this manner three times resulting in six hays. The hays were field dried, baled, and chopped prior to their use 3 to 6 mo after harvest. Three experiments were conducted [Exp. 1, sheep (Ovis aries); Exp. 2, goats (Capra hircus hircus); and Exp. 3, cattle (Bos taunts)] utilizing six animals in each case. During an adaptation phase, hays were offered alone as meals. In the experimental phase, every possible pair of hays (15 pairs) was presented for a meal. Data were analyzed by multidimensional scaling as well as by traditional analyses. Multidimensional scaling indicated that the animals were basing selection on at least two criteria. Variables associated with preference through multiple regression varied across experiments but significant coefficients were found between preference and nitrate, protein, carbohydrate fractions, lignin, and cellulose. Coefficients varied depending on which other variables were in the model; however, carbohydrates were associated with positive coefficients. Shifting hay mowing from early in the day to late in the day was effective in increasing forage preference as expressed by short-term dry matter intake

    Variation in ruminants' preference for tall fescue hays cut either at sundown or at sunup

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    Plants vary diurnally in concentrations of nonstructural carbohydrates. If ruminants prefer forages with higher total nonstructural carbohydrates (TNC), then the preference for hays harvested within the same 24-h period may vary. An established field of tall fescue (Festuca arundinacea Schreb.) was harvested six times in the vegetative stage. Harvests were paired such that each cutting at sundown (P M) was followed by a cutting the next morning at sunup (AM). We harvested in this manner three times, resulting in six hays. The hays were field-dried, baled, and passed through a hydraulic bale processor prior to feeding. Experiments were conducted with sheep, goats, and cattle, using six animals in each case. During an adaptation phase, hays were offered alone as meals. In the experimental phase, every possible pair of hays (15 pairs) was presented for a meal. Data were analyzed by multidimensional scaling and by traditional analyses. Multidimensional scaling indicated that selection was based on a single criterion. Preference for PM hays was greater than for AM hays (P < .01) in all experiments. Increased preference was associated with increased TNC (P < .01) and in vitro true DM disappearance (P < .01) and decreased fiber concentration (P < .01; NDF, ADF, cellulose, and ADL). Mowing hay late in the day was effective in increasing forage preference

    Landscape Gardening.

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    8 p

    Water Quantity and Quality from a Small Georgia Pasture During 1998-2009: Impact of Drought

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    Proceedings of the 2011 Georgia Water Resources Conference, April 11, 12, and 13, 2011, Athens, Georgia.The water quality impact of pasture grazing in the Piedmont, which generally occurs under low-input management, is not well studied. Cattle, hydrologic and water quality data were collected from 1999 to 2009 from a rotationally grazed 7.8-ha pasture near Watkinsville Georgia. Grazing occurred during 69 time periods, with 20 to 225 head of cattle grazing 1 to 71 days each period. Mean cattle days (head of cattle x days spent) was 182.4 ha⁻Âč grazing-period⁻Âč. Drought occurred with 7 of the 11 years having below average annual rainfall. Runoff events were limited to 20 during 86 months of below average rainfall (deficit period) compared with 54 during 46 months of the non-deficit period. Instrument problems limited sample collection to 43-47 out of possible 67 events from 2000-2009. Across all data, mean event flow weighted concentration (FWC) in mg L⁻Âč was < 1.0 for nitrate-nitrogen (NO₃-N) and ammonium-nitrogen (NH₄- N), 3.7 for total nitrogen (TN), 9.1 for total organic carbon (TOC), 2.0 for ortho-P (PO₄4-P), 2.4 for total P (TP), 0.23 for iron (Fe), and 0.06 for aluminum (Al). Nutrient loads in kg ha⁻Âč event⁻Âč averaged 0.04 for NO₃-N, 0.03 for NH₄-N, 0.19 for TN, 0.54 for TOC, 0.11 for (PO₄4-P, and TP, 0.02 for Fe, and 0.01 for Al. Peak nutrient concentrations and loads occurred during calving season and/or when monthly rainfall was above average. Total load was 3 to 6 times greater from non-deficit than deficit periods. Concentrations of N were well below drinking water standards. Nevertheless observed N and P losses could pose risk of eutrophication because it can be stimulated at low concentrations. Such long-term data are needed to help states set or refine water quality standards.Sponsored by: Georgia Environmental Protection Division U.S. Geological Survey, Georgia Water Science Center U.S. Department of Agriculture, Natural Resources Conservation Service Georgia Institute of Technology, Georgia Water Resources Institute The University of Georgia, Water Resources FacultyThis book was published by Warnell School of Forestry and Natural Resources, The University of Georgia, Athens, Georgia 30602-2152. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Research Institutes Authorization Act of 1990 (P.L. 101-307) or the other conference sponsors

    Results from Six Years of Community-Based Volunteer Water Quality Monitoring By the Upper Oconee Watershed Network

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    Proceedings of the 2007 Georgia Water Resources Conference, March 27-29, 2007, Athens, Georgia.The Upper Oconee Watershed Network (UOWN), an Athens, GA-based non-profit volunteer organization, was organized in 2000 with the mission to improve water quality in the Upper Oconee River basin through community-based advocacy, monitoring, and education. Quarterly monitoring of both reference and impaired stream segments form the basis for achieving all three of UOWN’s mission objectives. UOWN has developed a model for engaging the public in quarterly monitoring and in the larger annual River Rendezvous events. Quarterly monitoring not only tracks long-term trends in targeted stream segments, but also has resulted in the discovery and remediation of acute incidences of pollution. Six years of data collection revealed high levels of contamination in urban streams as evidenced by high conductivity and bacterial numbers, and potential limitations when using quarterly water quality monitoring to assess the health of Piedmont streams.Sponsored and Organized by: U.S. Geological Survey, Georgia Department of Natural Resources, Natural Resources Conservation Service, The University of Georgia, Georgia State University, Georgia Institute of TechnologyThis book was published by the Institute of Ecology, The University of Georgia, Athens, Georgia 30602-2202. The views and statements advanced in this publication are solely those of the authors and do not represent official views or policies of The University of Georgia, the U.S. Geological Survey, the Georgia Water Research Institute as authorized by the Water Resources Research Act of 1990 (P.L. 101-397) or the other conference sponsors

    b-Lactam antibiotics offer neuroprotection by increasing glutamate transporter expression

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    Glutamate is the principal excitatory neurotransmitter in the nervous system. Inactivation of synaptic glutamate is handled by the glutamate transporter GLT1 (also known as EAAT2; refs 1, 2), the physiologically dominant astroglial protein. In spite of its critical importance in normal and abnormal synaptic activity, no practical pharmaceutical can positively modulate this protein. Animal studies show that the protein is important for normal excitatory synaptic transmission, while its dysfunction is implicated in acute and chronic neurological disorders, including amyotrophic lateral sclerosis (ALS) 3 , stroke 4 , brain tumours 5 and epilepsy To identify compounds capable of increasing rodent GLT1 expression, a structurally diverse library of 1,040 FDA-approved drugs and nutritionals were individually added to organotypic spinal cord slice cultures prepared from postnatal day 9 rats To better understand the mechanism of action, the effect of the drugs on the GLT1 promoter was examined in cell lines fro

    The one dimensional Kondo lattice model at partial band filling

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    The Kondo lattice model introduced in 1977 describes a lattice of localized magnetic moments interacting with a sea of conduction electrons. It is one of the most important canonical models in the study of a class of rare earth compounds, called heavy fermion systems, and as such has been studied intensively by a wide variety of techniques for more than a quarter of a century. This review focuses on the one dimensional case at partial band filling, in which the number of conduction electrons is less than the number of localized moments. The theoretical understanding, based on the bosonized solution, of the conventional Kondo lattice model is presented in great detail. This review divides naturally into two parts, the first relating to the description of the formalism, and the second to its application. After an all-inclusive description of the bosonization technique, the bosonized form of the Kondo lattice hamiltonian is constructed in detail. Next the double-exchange ordering, Kondo singlet formation, the RKKY interaction and spin polaron formation are described comprehensively. An in-depth analysis of the phase diagram follows, with special emphasis on the destruction of the ferromagnetic phase by spin-flip disorder scattering, and of recent numerical results. The results are shown to hold for both antiferromagnetic and ferromagnetic Kondo lattice. The general exposition is pedagogic in tone.Comment: Review, 258 pages, 19 figure

    Donor misreporting:conceptualizing social desirability bias in giving surveys

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    Although survey research is one of the most frequently used methods for studying charitable giving, the quality of the data is seldom stated or known. In particular, social desirability bias (SDB) has been found to distort data validity where respondents tend to over-report what is socially desirable and vice versa. We argue that this phenomenon has not been fully understood in the nonprofit context as existing social desirability scales are not appropriate to be used in giving surveys. Thus, this paper is the first to extend understanding of SDB to the nonprofit context and to explore its motivating factors. Based on a multidisciplinary literature review and qualitative interviews with various senior practitioners from the fundraising and marketing research sectors, it is suggested that SDB is a multidimensional construct yielding five dimensions, namely, impression management, self-deception, level of involvement, perceived benefits and social norms. The paper then discusses the implications for nonprofit researchers and concludes with directions for future research
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