11,545 research outputs found

    Postbuckling behavior of graphite-epoxy panels

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    Structurally efficient fuselage panels are often designed to allow buckling to occur at applied loads below ultimate. Interest in applying graphite-epoxy materials to fuselage primary structure led to several studies of the post-buckling behavior of graphite-epoxy structural components. Studies of the postbuckling behavior of flat and curved, unstiffened and stiffened graphite-epoxy panels loaded in compression and shear were summarized. The response and failure characteristics of specimens studied experimentally were described, and analytical and experimental results were compared. The specimens tested in the studies described were fabricated from commercially available 0.005-inch-thick unidirectional graphite-fiber tapes preimpregnated with 350 F cure thermosetting epoxy resins

    Uganda aquaculture value chains: strategic planning mission report

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    This report presents the findings and recommendations of a strategic planning mission to reevaluate the feasibility of WorldFish implementing a fish value chain research program in Uganda under the CGIAR Research Program on Livestock and Fish (L&F). The over-arching goal of L&F is to increase productivity of small-scale livestock and fish systems so as to increase availability and affordability of meat, milk and fish for poor consumers and, in doing so, to reduce poverty through greater participation by the poor along animal source food value chains. This will be achieved by making a small number of carefully selected animal source food value chains function better, for example by identifying and addressing key constraints and opportunities (from production to consumption), improving institutional arrangements and capacities, and supporting the establishment of enabling pro-poor policy and institutional environments

    Uganda aquaculture value chains: strategic planning mission: summary report

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    This report presents the findings and recommendations of a strategic planning mission to reevaluate the feasibility of WorldFish implementing a fish value chain research program in Uganda under the CGIAR Research Program on Livestock and Fish (L&F). The over-arching goal of L&F is to increase productivity of small-scale livestock and fish systems so as to increase availability and affordability of meat, milk and fish for poor consumers and, in doing so, to reduce poverty through greater participation by the poor along animal source food value chains. This will be achieved by making a small number of carefully selected animal source food value chains function better, for example by identifying and addressing key constraints and opportunities (from production to consumption), improving institutional arrangements and capacities, and supporting the establishment of enabling pro-poor policy and institutional environments

    A New Technique for Escherichia coli Testing of Beef and Pork Carcasses

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    A novel technique has been developed to monitor Escherichia coli contamination on carcasses using membrane filtration and m-ColiBlue24 (mCB). mCB is a membrane filtration medium that simultaneously detects total coliforms and E. coli (EC) in a period of 24 +/- 4 h. A study was conducted, using a sponge method to obtain samples from pork carcasses and the excision technique to remove samples from beef carcasses, that compared mCB to standard methods. On pork carcasses (n = 77), the mean values for mCB and violet red bile agar were 7.4 CFU/15 cm2 and 6.1 CFU/15 cm2, respectively. The paired t test (P \u3e 0.05) indicated no significant difference between the two methods (t = 0.5; P = 0.6). Samples from beef carcasses (n = 57) were used to compare mCB to both coliform count and EC Petrifilm. Of these samples, 27 were artificially inoculated with cattle manure. The mean total coliform count was 4.2 log CFU/cm2 and 4.0 log CFU/cm2 on mCB and coliform count Petrifilm, respectively. The mean EC count on mCB was 4.0 log CFU/cm2 and 3.5 log CFU/cm2 on EC Petrifilm. When comparing mCB to both coliform count (t = 2.4; P = 0.02) and EC (t = 3.5; P \u3c 0.01) Petrifilm, paired t tests (P \u3c or = 0.05) indicated significant differences

    Comparative Recovery of Coliforms from Meat and Milk Using m-Coliblue24 and Standard Methods

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    A new membrane filtration medium, m-ColiBlue24 (mCB), simultaneously detects Total Coliforms (TC) and Escherichia coli (EC) in a single 24-hour incubation. Samples of ground beef, ground pork, and milk were analyzed by mCB and compared to standard methods. When TC from beef and pork samples were compared, there were no significant difference between mCB and pour plating on Violet Red Bile (VRB) agar. In a most probable number (MPN) analysis, nine counts from mCB were within the 95% confidence interval (CI) and 13 were outside the CI. VRB yielded six counts within and 16 outside the CI. The raw milk samples contained confirmed TC counts as high as 9.00X10 2 on mCB and 2.20X10 3 on VRB. Furthermore, the raw milk had up to 1.73X10 3 confirmed EC population. The BBL Crystal system was used to identify representative isolates from mCB and VRB. Of 59 mCB isolates, 64.4% were classical TC. Of the 51 VRB isolates, 62.7% were identified as classical TC

    Good rotations

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    Numerical integrations in celestial mechanics often involve the repeated computation of a rotation with a constant angle. A direct evaluation of these rotations yields a linear drift of the distance to the origin. This is due to roundoff in the representation of the sine s and cosine c of the angle theta. In a computer, one generally gets c^2 + s^2 1, resulting in a mapping that is slightly contracting or expanding. In the present paper we present a method to find pairs of representable real numbers s and c such that c^2 + s^2 is as close to 1 as possible. We show that this results in a drastic decrease of the systematic error, making it negligible compared to the random error of other operations. We also verify that this approach gives good results in a realistic celestial mechanics integration.Comment: 24 pages, 3 figure

    Reduced specificity of personal goals and explanations for goal attainment in major depression.

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    Published onlineJournal ArticleOBJECTIVES: Overgeneralization has been investigated across many domains of cognitive functioning in major depression, including the imagination of future events. However, it is unknown whether this phenomenon extends to representations of personal goals, which are important in structuring long-term behaviour and providing meaning in life. Furthermore, it is not clear whether depressed individuals provide less specific explanations for and against goal attainment. METHOD: Clinically depressed individuals and controls generated personally important approach and avoidance goals, and then generated explanations why they would and would not achieve these goals. Goals and causal explanations were subsequently coded as either specific or general. RESULTS: Compared to controls, depressed individuals did not generate significantly fewer goals or causal explanations for or against goal attainment. However, compared to controls, depressed individuals generated less specific goals, less specific explanations for approach (but not avoidance) goal attainment, and less specific explanations for goal nonattainment. SIGNIFICANCE: Our results suggest that motivational deficits in depression may stem partly from a reduction in the specificity of personal goal representations and related cognitions that support goal-directed behaviour. Importantly, the findings have the potential to inform the ongoing development of psychotherapeutic approaches in the treatment of depression

    Mid-depth South Atlantic Ocean circulation and chemical stratification during MIS-10 to 12: implications for atmospheric CO<sub>2</sub>

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    A detailed record of benthic foraminifera carbon isotopes from the intermediate-depth South East Atlantic margin shows little glacial-interglacial variability between MIS-12 to MIS-10, suggesting that Northern Atlantic deepwaters consistently penetrated to at least 30° S. Millennial-scale increases in either the mass or flux of northern-sourced deepwaters over the core site occurred alongside reductions in Lower North Atlantic Deep Water recorded in North Atlantic sediment cores and show that the lower and intermediate limb of the Atlantic deepwater convective cell oscillated in anti-phase during previous glacial periods. In addition, a 500 yr resolution record of the Cape Basin intermediate-deep δ13C gradient shows that a reduction in deep Southern Ocean ventilation at the end of MIS-11 was consistent with a modelled CO2 drawdown of ~21–30 ppm. Further increases in the Southern Ocean chemical divide during the transition into MIS-10 were completed before minimum CO2 levels were reached, suggesting that other mechanisms such as alkalinity changes were responsible for the remaining ~45 ppm drawdown
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