De l’aide des maquettes virtuelles à la restauration d’un ouvrage d’art historique. Le viaduc de Lambézellec (Brest)

La restauration du viaduc de Lambézellec s’appuie sur les résultats de recherches historiques menées sur la conception et la construction de cet ouvrage. Les plans, dessins techniques et explications issus du riche corpus documentaire (entre 1891 et 1893) présent aux archives départementales du Finistère ont en particulier permis de comprendre les choix technologiques adoptés par les ingénieurs, de reconstituer virtuellement ce viaduc pour proposer une description fidèle des différents éléments structuraux qui le constituent et ainsi offrir une aide précieuse aux travaux de réparation.The results of historical researches on the design and the construction of the viaduct of Lambézellec (Brest, France) support the restoration of this structure. Plans, technical drawings and explanations taken from the large corpus (between 1891 and 1893) of the Departmental Archives service of Finistère made it possible to better understand the technical solutions that were adopted, to virtually re-build the structure in order to describe its different parts with accuracy and thus be helpful for the repairs

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

De l'aide des maquettes virtuelles à la restauration d'un ouvrage d'art historique. Le viaduc de Lambézellec (Brest)

International audienc

Where do fishmeal and fish oil products come from? An analysis of the conversion ratios in the global fishmeal industry

International audienceAs a result of the stagnation of commercial fishery landings, aquaculture activities are expected to increase over the next decades to match the growing demand for marine protein Overall, it is expected that the aquaculture sector could reduce sonic of the fishing pressure applied to wild stocks However, this development is likely to be limited by the availability of key aquaculture inputs, specifically fishmeal and fish oil products (FMFOP) Aquaculture provided 60% (fish meal) and 80% (fish oil) of the world total consumption of these products in 2007 FMFOP are generally derived from small pelagic fish species, but can also be derived from other sources Identifying the origin of FMFOP is crucial to understanding the effects of this new pressure on marine social-ecological systems Two factors are of particular importance in the reduction sector transforming wild fish into fishmeal or fish oil the two "conversion ratios" (le the ratio between the quantity of wild fish harvested and the resulting quantity of FMFOP), and the ratio between the quantity of FMFOP and aquaculture production), and the type of raw material used by the reduction sector Based on trade and production databases from FAO and the International Fishmeal and Fish oil Organisation (IFFO), this paper proposes an approach to identify the origin of FMFOP It shows that whereas different countries use different pelagic resources to produce FMFOP, other countries use non-pelagic sources, and some countries use pelagic resources for human consumption (C) 2010 Elsevier Ltd All rights reserve

Tallinn : balte, post-soviétique et néo-libérale

Avec la participation des étudiants de Master AUDIT, Université Rennes 2International audienc

Where do fishmeal and fish oil products come from? An analysis of the conversion ratios in the global fishmeal industry

As a result of the stagnation of commercial fishery landings, aquaculture activities are expected to increase over the next decades to match the growing demand for marine protein. Overall, it is expected that the aquaculture sector could reduce some of the fishing pressure applied to wild stocks. However, this development is likely to be limited by the availability of key aquaculture inputs, specifically fishmeal and fish oil products (FMFOP). Aquaculture provided 60 % (fish meal) and 80 % (fish oil) of the world total consumption of these products in 2007. FMFOP are generally derived from small pelagic fish species, but can also be derived from other sources. Identifying the origin of FMFOP is crucial to understanding the effects of this new pressure on marine social-ecological systems. Two factors are of particular importance in the reduction sector transforming wild fish into fishmeal or fish oil: the two "conversion ratios" (i.e. the ratio between the quantity of wild fish harvested and the resulting quantity of FMFOP, and the ratio between the quantity of FMFOP and aquaculture production), and the type of raw material used by the reduction sector. Based on trade and production databases from FAO and the International Fishmeal and Fish oil Organisation (IFFO), this paper proposes an approach to identify the origin of FMFOP. It shows that whereas different countries use different pelagic resources to produce FMFOP, other countries use non-pelagic sources, and some countries use pelagic resources for human consumption.Fishmeal Fish oil Pelagic fish Aquaculture Sustainable growth Conversion ratios

Tallinn : balte, post-soviétique et néo-libérale

Avec la participation des étudiants de Master AUDIT, Université Rennes 2International audienc

Variation in actuarial senescence does not reflect life span variation across mammals

International audienc

Electrochemistry of [Mo2Cp2(CO)4μ-η2:η 3-HC≡C-C(R1)(R2)]+ complexes (R1 =H, R2 = H, Me, Et, Fc; R1 = Me, R2 = Me, Ph). Control of the reduction process (two-electron vs one-electron) by the substituents R1 and R2: EHMO rationalization

International audienceThe electrochemical reduction of [Mo2Cp2(CO)4_μ-η2:η 3-HC≡C-C(R1)(R2)_]+ complexes has been investigated by cyclic voltammetry, controlled-potential electrolysis, and coulometry. On the cyclic voltammetry time scale, the complexes with R1 = H, R2 = H (1+), Me (2+), Et (3+) undergo an irreversible or a quasi-reversible one-electron reduction whereas the analogues with R1 = H, R2 = Fc (4+) and R1 = Me, R2 = Me (5+) and Ph (6+) reduce in a single-step, reversible or quasi-reversible, two-electron process. Two different chemical reactions are involved in the overall reduction mechanism. The first chemical step is assigned as a structural rearrangement, responsible for slowing down the heterogeneous electron transfer. Extended Huckel MO calculations indicate that in the case of the complexes with R1 = H, R2 = Fc and R1 = Me, R2 = Me or Ph, a small increase in the distance between one metal center and the carbon of the C(R1)(R2) group could trigger the two-electron transfer process. The second chemical reaction leading to the final product(s) of the reduction involves radical species, even when a two-electron transfer is observed by cyclic voltammetry. The final products formed in these processes have been identified either by 1H NMR spectroscopy of the compounds extracted from the catholyte after controlled-potential electrolyses or from a comparison of their characteristic redox potentials with those of authentic samples. The nature of the final product(s), either a dimer or μ-alkyne and μ-enyne complexes, is also dependent on the nature of R1 and R2