3,551 research outputs found

    Advanced turboprop testbed systems study. Volume 1: Testbed program objectives and priorities, drive system and aircraft design studies, evaluation and recommendations and wind tunnel test plans

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    The establishment of propfan technology readiness was determined and candidate drive systems for propfan application were identified. Candidate testbed aircraft were investigated for testbed aircraft suitability and four aircraft selected as possible propfan testbed vehicles. An evaluation of the four candidates was performed and the Boeing KC-135A and the Gulfstream American Gulfstream II recommended as the most suitable aircraft for test application. Conceptual designs of the two recommended aircraft were performed and cost and schedule data for the entire testbed program were generated. The program total cost was estimated and a wind tunnel program cost and schedule is generated in support of the testbed program

    Hybrid exchange-correlation functional determined from thermochemical data and ab initio potentials

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    Multiplicative potentials, appropriate for adding to the non- multiplicative fractional orbital exchange term in the Kohn- Sham equations, are determined from correlated ab initio electron densities. The potentials are examined graphically and are used in conjunction with conventional thermochemical data to determine a new hybrid exchange-correlation functional, denoted B97-2. Calculations using B97-2 are compared with those from (a) the B97-1 functional [J. Chem. Phys. 109, 6264 (1998)], which has the same functional form and fraction of orbital exchange, but was fitted to just thermochemical data; and (b) the widely used B3LYP functional [J. Chem. Phys. 98, 5648 (1993)]. B97-2 atomization energies are close to those from B97-1; total electronic energies and ionization potentials are less accurate, but remain an improvement over B3LYP. Molecular structures from all three functionals are comparable. Static isotropic polarizabilities improve from B3LYP to B97-1 to B97-2; the B97-2 functional underestimates experimental values, which is consistent with the neglect of zero-point vibrational corrections. NMR shielding constants-determined as the conventional second derivative of the electronic energy- improve from B3LYP to B97-1 to B97-2. Shieldings determined directly from these DFT electron densities using the recently proposed MKS approach [Chem. Phys. Lett. 337, 341 (2001)] are two to three times more accurate than the conventional shieldings, and exhibit an analogous improvement across the three functionals. Classical reaction barriers for sixteen chemical reactions improve significantly from B3LYP to B97-1 to B97-2. The introduction of multiplicative potentials into semi- empirical hybrid functional development therefore appears beneficial

    Motherhood in the teens and twenties: some surprises.

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    We report a study of the association of health and social support variables with motherhood in teenagers and older mothers. Both teenage and older mothers reported poorer physical and mental health and fewer and less frequent social contacts than their nulliparous peers. Contrary to expectation, however, older mothers reported less extensive and less adequate social support networks than did teenagers

    Impact of Ramaekers Immune Primer on Finishing Beef Cattle Performance and Liver Abscess Rate

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    A feedlot study was conducted comparing a natural feed additive (Ramaekers Immune Primer) to Tylan or nothing on receiving and finishing performance. There were no differences for final BW, ADG, F:G, HCW, marbling, LM area, or fat thickness due to treatment. Liver abscess incidence and severity were reduced in steers fed Tylan, no differences were noted between Ramaekers Immune Primer and no additive. There was no difference in number of cattle treated for respiratory illness. Steers on the Ramaekers Immune Primer treatment had lower feed intake during the receiving period but had similar ADG and numerically better F:G at day 19 compared the control. These results suggest Ramaekers Immune Primer may be more beneficial, leading to increased performance, for younger, naive calves during the receiving phase

    Locating and eliminating feral swine from a large area of fragmented mixed forest and agriculture habitats in north-central USA

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    Illinois is one of the US states where elimination of feral swine (Sus scrofa) was determined practical, as only a few isolated populations were established. A particularly important step towards feral swine elimination from Illinois was to eliminate the population in Fulton County. We describe the approaches applied to systematically detect, locate, and eliminate feral swine in a successful county-wide elimination. Detecting and locating feral swine was facilitated by extensive outreach activities, aerial surveys to locate crop damage, and use of camera traps placed over bait in areas where reports, sign, or crop damage occurred. The population was eliminated after 376 feral swine were removed from 2009 to 2016 by trapping, sharpshooting over bait, and aerial shooting. Aerial surveys efficiently located feral swine activity over wide areas during times of the crop cycle when damage would occur and would be most distinguishable from other damage sources. Two applications of aerial shooting in 2014 were particularly efficient for rapidly eliminating most remaining feral swine after they had become difficult to locate and remove. Persistent efforts thereafter led to the successful elimination of feral swine in Fulton County by 2016.We believe this is the first documentation of a widespread feral swine elimination in mixed agriculture and forest habitats

    Real-Time Feedback of Air Quality in Children’s Bedrooms Reduces Exposure to Secondhand Smoke

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    Introduction:Secondhand smoke (SHS) exposure creates health risks for nonsmokers and is especially detrimental to children. This study evaluated whether immediate feedback in response to poor indoor air quality in children’s bedrooms can reduce the potential for SHS exposure, as measured by adherence to a World Health Organization (WHO) indoor air standard.Methods:Homes that contained children and an adult who regularly smoked inside (n=298) had an air particle monitor installed in the child’s bedroom. These devices measured the concentration of particulate matter (PM2.5) for approximately three months and, for half of the participants, immediately provided aversive feedback in response to elevated PM2.5. Hierarchical linear models were fit to the data to assess whether the intervention increased the probability that: 1) a given day was below the WHO guideline for daily exposure, and 2) a household established and maintained a smoke-free home (SFH), operationalized as achieving 30 consecutive days below the WHO guideline. The intervention’s impact was calculated as groupby- time effects.Results:The likelihood that a child’s bedroom met the WHO indoor air quality standard on a given day increased such that the baseline versus post-baseline odds ratio (OR) of maintaining indoor PM2.5 levels below the WHO guideline was 2.38 times larger for participants who received the intervention. Similarly, the baseline versus post-baseline OR associated with achieving an SFH was 3.49 times larger for participants in the intervention group.Conclusions:The real-time intervention successfully drove clinically meaningful changes in smoking behavior that mitigated indoor PM2.5 levels in children’s bedrooms and thereby reduced SHS exposure. These results demonstrate the effectiveness of targeting sensitive microenvironments by giving caregivers actionable information about children’s SHS risks. Future extensions should examine additional microenvironments and focus on identifying the potential for SHS exposure before it occurs

    Prevalence and determinants of the use of self-tests by members of the public: a mixed methods study

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    Background Self-tests can be used by members of the public to diagnose conditions without involving a doctor, nurse or other health professional. As technologies to design and manufacture diagnostic tests have developed, a range of self-tests have become available to the public to buy over-the-counter and via the Internet. This study aims to describe how many people have used self-tests and identify factors associated with their use. Methods A postal questionnaire will elicit basic information, including sociodemographic characteristics, and whether the person has used or would use specified self-tests. Consent will be sought to recontact people who want to participate further in the study, and interviews and focus groups will be used to develop hypotheses about factors associated with self-test use. These hypotheses will be tested in a case-control study. An in-depth questionnaire will be developed incorporating the identified factors. This will be sent to: people who have used a self-test (cases); people who have not used a self-test but would use one in the future (controls); and people who have not used and would not use a self-test (controls). Logistic regression analysis will be used to establish which factors are associated with self-test use. Discussion Self-tests do have potential benefits, for example privacy and convenience, but also potential harms, for example delay seeking treatment after a true negative result when the symptoms are actually due to another condition. It is anticipated that the outcomes from this study will include recommendations about how to improve the appropriate use of self-tests and existing health services, as well as information to prepare health professionals for patients who have used self-tests

    Celtic FC’s 1967 Lisbon Lions:Why the European Cup victory of the first club from Britain was a defining moment for the Irish diaspora in Scotland

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    In 1967, in Lisbon, Celtic Football Club, won the European Cup becoming the first club outside of Portugal, Spain and Italy to win it. The win was and is totemic for the Irish Catholic immigrant community in Scotland that has historically supported Celtic. We suggest the significance of the win reveals intersections of ethnicity, religion, nationalism, and the politics of ‘sectarianism’ in Scotland. During a period of discriminatory practices and attitudes towards Irish descended Catholics in Scotland, this iconic win for a Scottish based club born of Irish Catholics personified for this diaspora that (on one level) their day had arrived. This article explores the socio-cultural significance and legacy of ‘Lisbon 67ʹ for insider and outsider groups in Scotland. We reveal that soccer remains a central component of group memory connecting the past, present and future. We suggest Celtic’s win offered confidence and hope to a marginalized group within Scotland

    Removing Orbital Debris with Lasers

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    Orbital debris in low Earth orbit (LEO) are now sufficiently dense that the use of LEO space is threatened by runaway collisional cascading. A problem predicted more than thirty years ago, the threat from debris larger than about 1 cm demands serious attention. A promising proposed solution uses a high power pulsed laser system on the Earth to make plasma jets on the objects, slowing them slightly, and causing them to re-enter and burn up in the atmosphere. In this paper, we reassess this approach in light of recent advances in low-cost, light-weight modular design for large mirrors, calculations of laser-induced orbit changes and in design of repetitive, multi-kilojoule lasers, that build on inertial fusion research. These advances now suggest that laser orbital debris removal (LODR) is the most cost-effective way to mitigate the debris problem. No other solutions have been proposed that address the whole problem of large and small debris. A LODR system will have multiple uses beyond debris removal. International cooperation will be essential for building and operating such a system.Comment: 37 pages, 15 figures, in preparation for submission to Advances in Space Researc

    Probing a Complex of Cytochromecand Cardiolipin by Magnetic Circular Dichroism Spectroscopy: Implications for the Initial Events in Apoptosis

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    Oxidation of cardiolipin (CL) by its complex with cytochrome c (cyt c) plays a crucial role in triggering apoptosis. Through a combination of magnetic circular dichroism spectroscopy and potentiometric titrations, we show that both the ferric and ferrous forms of the heme group of a CL:cyt c complex exist as multiple conformers at a physiologically relevant pH of 7.4. For the ferric state, these conformers are His/Lys- and His/OH–-ligated. The ferrous state is predominantly high-spin and, most likely, His/–. Interconversion of the ferric and ferrous conformers is described by a single midpoint potential of -80 ± 9 mV vs SHE. These results suggest that CL oxidation in mitochondria could occur by the reaction of molecular oxygen with the ferrous CL:cyt c complex in addition to the well-described reaction of peroxides with the ferric form
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