1,027 research outputs found

    Letter to Charles Pettit McIlvaine

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    Bishop Whittingham laboriously precise in telling McIlvaine of procedure which had McIlvaine pastoral letter passed over by Bishop Hopkins. Unity will come, but not without some difficulty.https://digital.kenyon.edu/mcilvaine_letters/1369/thumbnail.jp

    Factorization fits to charmless strangeless B decays

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    We present fits to charmless strangeless hadronic B decay data for mean branching ratios and CP-violating asymmetries using the QCD factorization model of Beneke et al. Apart from one CP-violating parameter, the model gives a very good representation of 26 measured data. We find the CKM angle alpha = (93.5 +/- 8.4 -1.3) degrees and to be quite stable to plausible "charming penguin" corrections.Comment: 4 pages, LaTeX, Minor changes to text, references adde

    Gluon and gluino penguin diagrams and the charmless decays of the b quark

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    Gluon mediated exclusive hadronic decays of b quarks are studied within the standard model (SM) and the constrained minimally supersymmetric standard model (MSSM). For all allowed regions of the MSSM parameter space (A, tan beta, m_0, m_{1/2}) the penguin magnetic dipole form factor F^R_2 is dominant over the electric dipole and can be larger than the magnetic dipole form factor of the SM. However, overall the SM electric dipole decay amplitude F^L_1 dominates the decay rate. The MSSM penguin contributions to the free quark decay rate approach the 10% level for those regions of parameter space close to the highest allowed values of tan beta (~55) for which the gluino is light (m_{\tilde{g}} \approx 360 GeV) and lies within the range of the six d-squark masses. In these regions the supersymmetric box amplitudes are negligible. The MSSM phases change very little over the allowed parameter space and can lead to significant interference with the SM amplitudes

    Synthesis of H<sub>x</sub>Li<sub>1-x</sub>LaTiO<sub>4</sub> from quantitative solid-state reactions at room temperature

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    The layered perovskite HLaTiO4 reacts stoichiometrically with LiOH·H2O at room temperature to give targeted compositions in the series HxLi1-xLaTiO4. Remarkably, the Li+ and H+ ions are quantitatively exchanged in the solid state and this allows stoichiometric control of ion exchange for the first time in this important series of compounds

    1015-71 Lower Adenosine Levels During Early Ischemia: Cause of Increased Injury in the Aging Heart?

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    Myocardial injury following ischemia and reperfusion is increased in the aging heart, including in the aging 24 mo Fischer 344 rat (mean survival 29 mo) compared to the Fischer 344 adult (6 mo). Adenosine (ADO) has been increasingly appreciated as a cardioprotective agent in myocardial ischemia. We hypothesized that a potential mechanism of the increased injury in the aging heart is decreased production of ADO in response to ischemia. Isolated buffer perfused (glucose 5 mM — insulin 5 μ/1) hearts from aging and adult Fischer 344 rats were subjected to stop-flow ischemia for either 2, 5, 10, 15 or 25 min after a 15 min equilibration phase. ADO and hypoxanthine (HX) were measured by HPLC. Tissue total adenylates, ATP, glycogen and lactate were measured.IschemiaPre-ischemia2 min5 min10 min15 min25 min(n=5)(n=5)(n=5)(n=5)(n=5)(n=5)ADO 6 mo0.2±0.10.7±0.10.7±0.12.2±0.237±0.64.5±0.324 mo0.2±0.105±0.10.3±0.1*1.1±0.3*2.1±0.3*3.5±0.4HX 6 mo2.0±0.21.6±0.22.3±0.32.2±0.125±0.22.8±0.224mo1.9±0.21.4±0.11.4±0.2*2.1±0.22.2±0.83.5±0.3(Mean±SE, nmol/mg protein)*p&lt;0.05 vs 6 moADO levels were 50% lower in the aging heart at 5 and 10 min, remained depressed at 15 min and had not fully equalized to adult levels by 25 min of ischemia. HX was decreased at 5 min, consistent with decreased ADO production at that time. The change in total adenylate pool was similar in both groups. The decrease in tissue glycogen and increase in lactate were similar during ischemia in both groups, suggesting comparable glycolytic activity. ATP levels were decreased in aging hearts at 5 min (11.1±2.3 vs 18.7±1.9 nmol/mg protein), but reached levels similar to adult hearts as ischemia progressed.Thus, decreased ADO levels during early ischemia may reflect reduced production of ADO in the aging heart, and increase the susceptibility of the aging heart to damage during ischemia and reperfusion

    A framework for managing airport grasslands and birds amidst conflicting priorities

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    Management of modern airports is a task beset by conflicting priorities. Airports are vital to the global market economy, but impose costly environmental disturbances including habitat loss, noise, reduced air quality, erosion, introduction of invasive organisms, and polluted storm-water runoff (Blackwell et al. 2009). Airport environments also attract some wildlife hazardous to aviation safety, namely species involved in wildlife-aircraft collisions or ‘strikes’ (ICAO 2001, Blackwell et al. 2009, DeVault et al. 2011). Since 1912 at least 276 human lives have been lost due to bird strikes (Thorpe 2010), and from 1990 to 2010, more than 106 000 bird strikes involving civil aircraft were reported to the US Federal Aviation Administration (FAA; http://wildlife-mitigation. tc.faa.gov/wildlife/). Dolbeer (2006) reported that for strikes resulting in substantial aircraft damage (ICAO 1989), 66% occurred below 152 m altitude and within 1.5 km of a runway for airports servicing piston-powered aircraft only, and within 3 km of a runway for airports servicing turbine-powered aircraft (FAA 2009). Consequently, aviation authorities prioritize human safety over wildlife conservation in management of airport habitats (ICAO 2001, FAA 2009). Despite these problems, airports have been proposed as candidates for biodiversity conservation (Kelly & Allan 2006, Blackwell et al. 2009). For example, Kutschbach- Brohl et al. (2010) report that airport grasslands can provide habitat for a range of arthropod communities (e.g. Lepidoptera), and suggest the possibility of conserving these communities while minimizing provision of prey resources to birds recognized as hazardous to aviation. Moreover, declines in grassland bird populations in Europe and North America due to agricultural intensification and development have focused attention on enhancing quality and quantity of remnant grasslands (Herkert 1994, Vickery et al. 2004), including airport grasslands. In North America, airport properties have been identified as key areas of remnant grasslands important to obligate grassland bird species; species that both nest and forage in grasslands (Vickery et al. 1994, Askins et al. 2007). Airport properties in the contiguous USA include \u3e 330 000 ha of grassland, mostly annually mown areas, constituting 39–50% of airport property (DeVault et al. 2012). However, there is little research specific to airport environments that considers food resources for birds (Bernhardt et al. 2010, Kutschbach-Brohl et al. 2010), how birds perceive and react to predation risk (Baker & Brooks 1981) or disturbance (Kershner & Bollinger 1996), and no adequate assessment of how grassland management might affect strike risk (Blackwell et al. 2009, Martin et al. 2011). In this context, we contend that promoting conservation of obligate grassland birds and managing to reduce bird hazards to aviation safety combines two potentially conflicting objectives in a single management framework. Ecologically based guidance to solve this potential conflict is limited, if not oversimplified. Here, we question the potential use of airports to conserve grassland birds, and assess the challenges in managing airport grasslands in light of current ecological and behavioral frameworks. We consider conditions for conservation of obligate grassland birds on airports, and evidence on the use of airports by frequently struck, grassland birds (both obligate and facultative). We also provide a framework to manage grassland birds at airports, given current information and uncertainty. Because of the availability of strike data via the FAA, our focus is on North America. However, problems associated with bird use of airport grasslands are international (ICAO 2001). Therefore, our ultimate purpose is better to inform current management, but also identify research gaps and establish specific predictions that will guide future studies on the ecological basis of use of airport grasslands by birds
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