241 research outputs found

    Material behaviour at low temperatures for calibrating cryogenic machining numerical simulations

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    Abstract Recently, cryogenic machining of difficult-to-cut alloys has been adopted to increase tool life and improve the machined components surface integrity. Numerical models of cryogenic machining are being developed to evaluate the influence of the different process parameters. Up to now, their calibration in terms of material flow stress is fulfilled using data at conventional temperatures, whereas the material sensitivity to temperatures lower than the environment one should be taken into account. To this regard, the paper objective is to present material data, obtained through a newly developed Split Hopkinson Tension Bar, at cryogenic temperatures and high strain rates to properly calibrate cryogenic machining numerical models

    Determinants of Non-Vaccination against Pandemic 2009 H1N1 Influenza in Pregnant Women: A Prospective Cohort Study

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    International audienceBACKGROUND: In October 2009, the French government organized a national-wide, free of charge vaccination campaign against pandemic H1N1 influenza virus, especially targeting pregnant women, a high risk group for severe illness. The study objective was to evaluate pandemic flu vaccine uptake and factors associated with non-vaccination in a population of pregnant women. METHODOLOGY/PRINCIPAL FINDINGS: In a prospective cohort conducted in 3 maternity hospitals in Paris, 882 pregnant women were randomly included between October 12, 2009 and February 3, 2010, with the aim to study characteristics of pandemic influenza during pregnancy. At inclusion, socio-demographic, medical, obstetrical factors and those associated with a higher risk of flu exposition and disease-spreading were systematically collected. Pandemic flu vaccine uptake was checked until delivery. 555 (62.9%) women did not get vaccinated. Determinants associated with non-vaccination in a multivariate logistic regression were: geographic origin (Sub-Saharan African origin, adjusted Odd Ratio aOR = 5.4[2.3-12.7], North African origin, aOR = 2.5[1.3-4.7] and Asian origin, aOR = 2.1[1.7-2.6] compared to French and European origin) and socio-professional categories (farmers, craftsmen and tradesmen, aOR = 2.3[2.0-2.6], intermediate professionals, aOR = 1.3[1.0-1.6], employees and manual workers, aOR = 2.5[1.4-4.4] compared to managers and intellectual professionals). The probability of not receiving pandemic flu vaccine was lower among women vaccinated against seasonal flu in the previous 5 years (aOR = 0.6[0.4-0.8]) and among those who stopped smoking before or early during pregnancy (aOR = 0.6[0.4-0.8]). Number of children less than 18 years old living at home, work in contact with children or in healthcare area, or professional contact with the public, were not associated with a higher vaccine uptake. CONCLUSIONS/SIGNIFICANCE: In this cohort of pregnant women, vaccine coverage against pandemic 2009 A/H1N1 flu was low, particularly in immigrant women and those having a low socio-economic status. To improve its effectiveness, future vaccination campaign for pregnant women should be more specifically tailored for these populations

    Productive restructuring and the reallocation of work and employment: a survey of the “new” forms of social inequality

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    O propósito do presente artigo consiste em questionar a inevitabilidade dos processos de segmentação e precarização das relações de trabalho e emprego, responsáveis pela inscrição de “novas” formas de desigualdade social que alicerçam o actual modelo de desenvolvimento das economias e sociedades. Visa-se criticar os limites da lógica econômica e financeira, de contornos globais, que configuram um “novo espírito do capitalismo”, ou seja, uma espécie de divinização da ordem natural das coisas. Impõe-se fazer, por isso, um périplo analítico pelas transformações em curso no mercado de trabalho, acompanhado pela vigilância epistemológica que permita enquadrar e relativizar as (di)visões neoliberais e teses tecnodeterministas dominantes. A perspectivação de cenários sobre o futuro do trabalho encerrará este périplo, permitindo-nos alertar para os condicionalismos histórico-temporais, para a urgência de se desocultar o que de ideológico e político existe nas actuais lógicas de racionalização e para os processos de ressimbolização do trabalho e emprego enquanto “experiência social central” na contemporaneidade.The scope of this paper is to question the inevitability of the processes of segmentation and increased precariousness of the relations of labor and employment, which are responsible for the introduction of “new” forms of social inequality that underpin the current model of development of economies and societies. It seeks to criticize the limits of global financial and economic logic, which constitute a “new spirit of capitalism,” namely a kind of reverence for the natural order of things. It is therefore necessary to conduct an analytical survey of the ongoing changes in the labor market, accompanied by epistemological vigilance which makes it possible to see neoliberal (di)visions and dominant technodeterministic theses in context. The enunciation of scenarios on the future of work will conclude this survey and will make it possible to draw attention to both the historical and temporal constraints and to the urgent need to unveil what is ideological and political in the prevailing logic of rationalization and processes to reinstate work and employment as a “central social experience” in contemporary times

    Evolution of the ridges of Midelt-Errachidia section in the High Atlas revealed by paleomagnetic data

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    New paleomagnetic data (43 sites) from Mesozoic sediments are contributed in this work, verifying the presence of a pervasive syntectonic Early Cretaceous remagnetization in the easternmost area of the Moroccan High Atlas. Using the small circle intersection method, we have calculated the characteristic remagnetization direction (Dec: 337.3, Inc: 38.4) that fits with a 100-Ma age, according to the Apparent Polar Wander Path of Africa. The paleomagnetic vectors of remagnetization are used to obtain the geometry during the remagnetization stage (100Ma) of one of the most renowned geological cross sections of the High Atlas, the Midelt-Errachidia profile. The partial restoration of the cross section at 100Ma allows us to determine the dips of the beds at the remagnetization stage in five structures (ridges or anticlines). Our results indicate that the five ridges that configure the Midelt-Errachidia profile were initiated to different degrees prior to wholesale compressive deformation during the Cenozoic. This configuration can be explained according to two different scenarios that we discuss in this paper: transpression and diapirism. The geological model obtained, both at present and at 100Ma, indicates the existence of a Mesozoic cover substantially decolled from the Paleozoic basement, what strongly contrasts with previously published transects of the same area

    Clinical features and risk factors for severe and critical pregnant women with 2009 pandemic H1N1 influenza infection in China

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    <p>Abstract</p> <p>Background</p> <p>2009 pandemic H1N1 (pH1N1) influenza posed an increased risk of severe illness among pregnant women. Data on risk factors associated with death of pregnant women and neonates with pH1N1 infections are limited outside of developed countries.</p> <p>Methods</p> <p>Retrospective observational study in 394 severe or critical pregnant women admitted to a hospital with pH1N1 influenza from Sep. 1, 2009 to Dec. 31, 2009. rRT-PCR testing was used to confirm infection. In-hospital mortality was the primary endpoint of this study. Univariable logistic analysis and multivariate logistic regression analysis were used to investigate the potential factors on admission that might be associated with the maternal and neonatal mortality.</p> <p>Results</p> <p>394 pregnant women were included, 286 were infected with pH1N1 in the third trimester. 351 had pneumonia, and 77 died. A PaO<sub>2</sub>/FiO<sub>2 </sub>≤ 200 (odds ratio (OR), 27.16; 95% confidence interval (CI), 2.64-279.70) and higher BMI (i.e. ≥ 30) on admission (OR, 1.26; 95% CI, 1.09 to 1.47) were independent risk factors for maternal death. Of 211 deliveries, 146 neonates survived. Premature delivery (OR, 4.17; 95% CI, 1.19-14.56) was associated neonatal mortality. Among 186 patients who received mechanical ventilation, 83 patients were treated with non-invasive ventilation (NIV) and 38 were successful with NIV. The death rate was lower among patients who initially received NIV than those who were initially intubated (24/83, 28.9% vs 43/87, 49.4%; <it>p </it>= 0.006). Septic shock was an independent risk factor for failure of NIV.</p> <p>Conclusions</p> <p>Severe hypoxemia and higher BMI on admission were associated with adverse outcomes for pregnant women. Preterm delivery was a risk factor for neonatal death among pregnant women with pH1N1 influenza infection. NIV may be useful in selected pregnant women without septic shock.</p
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