478 research outputs found

    Flora of the Erie Islands: A Review of Floristic, Ecological and Historical Research and Conservation Activities, 1976 – 2010

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    Author Institution: Lake Erie Islands Chapter, Black Swamp Conservancy, Put-in-Bay, OHAuthor Institution: Biota of North American Program, Chapel Hill, NCAuthor Institution: Ontario Natural Heritage Information Centre, Ministry of Natural Resources, Ontario, CanadaThe purpose of this review is to survey the floristic, ecological and historical research about the Erie Islands and its flora since 1976 and to describe efforts to conserve Erie Island habitats. Island location records, surveys and multi-island inventories reveal that over 1,000 vascular plant taxa are known from the Erie Islands and new records continue to be found. Alvar habitats, rare globally, occur on the Erie Islands and are a focus of conservation efforts. Forest composition is primarily related to island elevation above lake level and moisture availability. Patterns of succession in abandoned vineyards and orchards are not the same due to differing agricultural practices prior to abandonment that favored different suites of invading species. Applying island biogeographic theory and methods to analyze the flora of the Erie Islands demonstrated that the indigenous flora on individual islands varies in relation to the size of an island in accordance with biogeographic theory whereas the non-indigenous flora on smaller islands is a constantly changing random subset of the non-indigenous flora of larger islands. Geological and palynological research about pre-settlement forests support the historic descriptions of these forests by early European settlers. Governmental and private efforts to preserve Erie Island habitats and the flora therein expanded significantly in the past 35 years. Efforts by the State of Ohio, the Province of Ontario, non-governmental organizations and island communities to acquire and conserve unique island habitats resulted in the preservation of important alvar, wetland and woodland habitat on large islands and the acquisition of Green Island, Middle Island and West Sister Island

    1-D Transient Thermal Modeling of an Ablative Material (MCC-1) Exposed to a Simulated Convective Titan 4 Launch Environment

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    The purpose of the work is to demonstrate that the flat test panel substrate temperatures are consistent with analysis predictions for MCC-1 applied to a aluminum substrate. The testing was performed in an aerothermal facility on samples of three different thicknesses of MCC-1 on an aluminum substrate. The results of the test were compared with a Transient Thermal model. The key assumptions of the Transient Thermal model were: (1) a one-dimensional heat transfer; (2) a constant ablation recession rate (determined from pre and post-test measurements); (3) ablation temperature of 540 degrees F; (4) Char left behind the ablation front; and (5) temperature jump correction for incident heat transfer coefficient. Two methods were used to model the heating of bare MCC-1: (1) Directly input surface temperature as a function of time; and (2) Aerothermal heating using calibration plate data and subtracting the radiation losses to tunnel walls. The results are presented as graphs. This article is presented in Viewgraph format

    Strong contribution to octet baryon mass splittings

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    We calculate the mdmum_d-m_u contribution to the mass splittings in baryonic isospin multiplets using SU(3) chiral perturbation theory and lattice QCD. Fitting isospin-averaged perturbation theory functions to PACS-CS and QCDSF-UKQCD Collaboration lattice simulations of octet baryon masses, and using the physical light quark mass ratio mu/mdm_u/m_d as input, allows MnMpM_n-M_p, MΣMΣ+M_{\Sigma^-}-M_{\Sigma^+} and MΞMΞ0M_{\Xi^-}-M_{\Xi^0} to be evaluated from the full SU(3) theory. The resulting values for each mass splitting are consistent with the experimental values after allowing for electromagnetic corrections. In the case of the nucleon, we find MnMp=2.9±0.4MeVM_n-M_p= 2.9 \pm 0.4 \textrm{MeV}, with the dominant uncertainty arising from the error in mu/mdm_u/m_d

    Sigma-term physics in the perturbative chiral quark model

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    We apply the perturbative chiral quark model (PCQM) at one loop to analyse meson-baryon sigma-terms. Analytic expressions for these quantities are obtained in terms of fundamental parameters of low-energy pion-nucleon physics (weak pion decay constant, axial nucleon coupling, strong pion-nucleon form factor) and of only one model parameter (radius of the nucleonic three-quark core). Our result for the piN sigma term of about 45 MeV is in good agreement with the value deduced by Gasser, Leutwyler and Sainio using dispersion-relation techniques and exploiting the chiral symmetry constraints.Comment: 19 pages, LaTeX-file, 2 Figure

    Outcomes and Complications With Off-Label Use of Drug-Eluting Stents Results From the STENT (Strategic Transcatheter Evaluation of New Therapies) Group

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    ObjectivesThis study evaluates outcomes and complications in patients treated with drug-eluting stents (DES) for “off-label” indications.BackgroundDrug-eluting stents have been effective in randomized trials, but their safety and efficacy for off-label indications has not been well studied.MethodsThe STENT (Strategic Transcatheter Evaluation of New Therapies) Registry is the largest multicenter U.S. registry evaluating outcomes of DES. Off-label indications included ostial, left main, long, bifurcation, and in-stent restenotic lesions, saphenous vein grafts, chronic total occlusions, small or large vessels, multilesion or multivessel percutaneous coronary interventions, and ST-segment elevation myocardial infarction. Outcomes were adjusted using Cox proportional hazards regression and propensity analyses.ResultsDrug-eluting stents were used in an off-label manner in 59% of patients. The patients who received off-label treatment were more often male, had a higher incidence of prior infarction and bypass surgery, and lower ejection fractions. Off-label versus “on-label” use of DES was associated with higher rates of death, myocardial infarction, target vessel revascularization, major adverse cardiac events, and stent thrombosis at 9 months and 2 years. Off-label use of DES compared with off-label use of bare-metal stents (BMS) had lower rates of death, myocardial infarction, target vessel revascularization, and major adverse cardiac events at 9 months and 2 years and lower rates of stent thrombosis at 9 months.ConclusionsOff-label use of DES is associated with higher event rates compared with on-label use of DES, which is consistent with a higher risk clinical and lesion profile. However, event rates with off-label use of DES are lower compared with off-label use of BMS. Pending results from randomized trials, our data support the use of DES for off-label indications in selected patients
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