55 research outputs found

    Dynamic Critical Behavior of a Swendsen-Wang-Type Algorithm for the Ashkin-Teller Model

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    We study the dynamic critical behavior of a Swendsen-Wang-type algorithm for the Ashkin--Teller model. We find that the Li--Sokal bound on the autocorrelation time (τint,E≄const×CH\tau_{{\rm int},{\cal E}} \ge {\rm const} \times C_H) holds along the self-dual curve of the symmetric Ashkin--Teller model, and is almost but not quite sharp. The ratio τint,E/CH\tau_{{\rm int},{\cal E}} / C_H appears to tend to infinity either as a logarithm or as a small power (0.05≀p≀0.120.05 \leq p \leq 0.12). In an appendix we discuss the problem of extracting estimates of the exponential autocorrelation time.Comment: 59 pages including 3 figures, uuencoded g-compressed ps file. Postscript size = 799740 byte

    Effect of alirocumab on mortality after acute coronary syndromes. An analysis of the ODYSSEY OUTCOMES randomized clinical trial

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    Background: Previous trials of PCSK9 (proprotein convertase subtilisin-kexin type 9) inhibitors demonstrated reductions in major adverse cardiovascular events, but not death. We assessed the effects of alirocumab on death after index acute coronary syndrome. Methods: ODYSSEY OUTCOMES (Evaluation of Cardiovascular Outcomes After an Acute Coronary Syndrome During Treatment With Alirocumab) was a double-blind, randomized comparison of alirocumab or placebo in 18 924 patients who had an ACS 1 to 12 months previously and elevated atherogenic lipoproteins despite intensive statin therapy. Alirocumab dose was blindly titrated to target achieved low-density lipoprotein cholesterol (LDL-C) between 25 and 50 mg/dL. We examined the effects of treatment on all-cause death and its components, cardiovascular and noncardiovascular death, with log-rank testing. Joint semiparametric models tested associations between nonfatal cardiovascular events and cardiovascular or noncardiovascular death. Results: Median follow-up was 2.8 years. Death occurred in 334 (3.5%) and 392 (4.1%) patients, respectively, in the alirocumab and placebo groups (hazard ratio [HR], 0.85; 95% CI, 0.73 to 0.98; P=0.03, nominal P value). This resulted from nonsignificantly fewer cardiovascular (240 [2.5%] vs 271 [2.9%]; HR, 0.88; 95% CI, 0.74 to 1.05; P=0.15) and noncardiovascular (94 [1.0%] vs 121 [1.3%]; HR, 0.77; 95% CI, 0.59 to 1.01; P=0.06) deaths with alirocumab. In a prespecified analysis of 8242 patients eligible for ≄3 years follow-up, alirocumab reduced death (HR, 0.78; 95% CI, 0.65 to 0.94; P=0.01). Patients with nonfatal cardiovascular events were at increased risk for cardiovascular and noncardiovascular deaths (P<0.0001 for the associations). Alirocumab reduced total nonfatal cardiovascular events (P<0.001) and thereby may have attenuated the number of cardiovascular and noncardiovascular deaths. A post hoc analysis found that, compared to patients with lower LDL-C, patients with baseline LDL-C ≄100 mg/dL (2.59 mmol/L) had a greater absolute risk of death and a larger mortality benefit from alirocumab (HR, 0.71; 95% CI, 0.56 to 0.90; Pinteraction=0.007). In the alirocumab group, all-cause death declined wit h achieved LDL-C at 4 months of treatment, to a level of approximately 30 mg/dL (adjusted P=0.017 for linear trend). Conclusions: Alirocumab added to intensive statin therapy has the potential to reduce death after acute coronary syndrome, particularly if treatment is maintained for ≄3 years, if baseline LDL-C is ≄100 mg/dL, or if achieved LDL-C is low. Clinical Trial Registration: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01663402

    Selva Oscura

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    À l’épreuve de l’arbre Sur les empreintes d’Alan Guillou Allan Guillou est photographe et planteur d’arbres. Son biotope originel est la forĂȘt du FinistĂšre au cƓur de laquelle, enfant, il accompagnait son pĂšre faire du bois. Depuis, la forĂȘt ne l’a pas quittĂ©, elle prospĂšre dans son imaginaire d’artiste et Ă  travers son activitĂ© de militant. À la suite d’un bac STAE et d’un BTS « AmĂ©nagements paysagers » Ă  Montreuil, un emploi jeune fait un temps de lui le responsable du conservatoire botaniq..

    The Carboniferous (Serpukhovian) macroflora from the “Coteaux du Pont BarrĂ©â€, Beaulieu-sur-Layon (Maine-et-Loire), South of the Armorican Massif, France

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    International audienceThe “Coteaux du Pont BarrĂ©â€ in Beaulieu-sur-Layon is a Regional Natural Reserve which is home to exceptional flora and fauna. Recently fossil plants have been discovered at the site adding to its natural heritage significance. The exposure which is part of the “Sillon Houiller de la Basse-Loire” contains Serpukhovian-age (330–320 Ma) remains of sphenophytes, ferns, and lyginopteridopsid and cycadopsid pteridosperms, which are described for the first time as well as the geology of the site. Most Carboniferous macroflora previously described from the Maine-et-Loire has been based on ex situ specimens from now abandoned and inaccessible coal mines. The newly described macroflora shows evidence of in situ remains and differs somewhat in composition from those reported from the coal workings, especially in the total absence of lycopsids and Calymmotheca pteridosperms, and instead having abundant medullosalean foliage (Neuralethopteris). The co-occurrence of Sphenopteris elegans and Neuralethopteris densifolia suggests a slightly younger age compared to the macrofloras documented from the coal-bearing deposits. However, this could be an ecological consequence of the flora growing in better-drained substrate habitats

    The Carboniferous (Serpukhovian) macroflora from the “Coteaux du Pont BarrĂ©â€, Beaulieu-sur-Layon (Maine-et-Loire), South of the Armorican Massif, France

    No full text
    The “Coteaux du Pont BarrĂ©â€ in Beaulieu-sur-Layon is a Regional Natural Reserve which is home to exceptional flora and fauna. Recently fossil plants have been discovered at the site adding to its natural heritage significance. The exposure which is part of the “Sillon Houiller de la Basse-Loire” contains Serpukhovian-age (330–320 Ma) remains of sphenophytes, ferns, and lyginopteridopsid and cycadopsid pteridosperms, which are described for the first time as well as the geology of the site. Most Carboniferous macroflora previously described from the Maine-et-Loire has been based on ex situ specimens from now abandoned and inaccessible coal mines. The newly described macroflora shows evidence of in situ remains and differs somewhat in composition from those reported from the coal workings, especially in the total absence of lycopsids and Calymmotheca pteridosperms, and instead having abundant medullosalean foliage (Neuralethopteris). The co-occurrence of Sphenopteris elegans and Neuralethopteris densifolia suggests a slightly younger age compared to the macrofloras documented from the coal-bearing deposits. However, this could be an ecological consequence of the flora growing in better-drained substrate habitats.Copyright © 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/bync-nd/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited, and is not altered, transformed, or built upon in any way. The linked document is the published version of the article.NHM Repositor

    Agroforestry in the Hauts-de-France -A Research and Demonstration Experimental Site in Ramecourt

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    AFFInternational audienceAs the current agricultural practices in the Hauts-de-France region result in soil erosion, nitrate leaching and a decline in biodiversity, agroforestry systems (AFs) may be an alternative to conciliate productivity with lower environmental impact (Dupraz and Liagre, 2008). We set up the first AF experimental site to study its agro-economic and environmental performance in local agro-pedoclimatic conditions. The experimental site was established in autumn 2018 on an 18-ha plot in Ramecourt on a deep luvic cambisol with a silt loam texture developed on a flint clay. Due to a high silt content (73% silt) and a low organic matter content (2%), as well as a slope of 8%, the plot is highly affected by channel erosion. Modalities with or without nitrogen-fixing trees in AF treatment are compared with sole-crop (CC) and pure-forest control (FC) plots (Figure 1A) according to a randomised block design with 3 replicates. Tall trees in rows are intercalated with 9 species of shrubs (Figure 1B) and will be intercropped in AFs by sugar beet, potato, wheat, barley and flax. The tree density is 50 and 430 trees ha-1 for AFs and FC respectively, and the average size of the microplots is 0.9 ha. Using this experimental approach, we hypothesised that AFs should limit soil erosion, restore soil fertility and biodiversity, improve natural-resource use efficiency and water quality, reduce inputs and increase farmers’ incomes
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