635 research outputs found

    Occurrence and numerical prediction of surface defects during flanging of metallic sheets

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    International audienceSurface defects can develop on automotive exterior panels after drawing and flanging steps, during springback and may alter significantly the vehicle quality. These defects are characterized by a small depth below 0.5 mm and are then difficult to detect numerically. This study focuses on the surface defects for two parts: an industrial upper corner of a front door and a L-shaped part designed on purpose to reproduce at a small scale surface defects that occur after flanging. Dimensions of these defects are measured from profiles obtained either with a non-contacting method or a tridimensional measuring machine. Numerical simulations of the processes are performed with the commercial codes PamStamp2G or Abaqus and deformed meshes are analyzed in the same way as the experimental data. There is a good correlation between experiments and simulations concerning the spatial position of the defect and their dimensions. Moreover, a buckling analysis during springback is performed for the L-shaped part, showing that the position of the defect corresponds to one of the buckling mode

    Quenched convergence of a sequence of superprocesses in R^d among Poissonian obstacles

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    We prove a convergence theorem for a sequence of super-Brownian motions moving among hard Poissonian obstacles, when the intensity of the obstacles grows to infinity but their diameters shrink to zero in an appropriate manner. The superprocesses are shown to converge in probability for the law P\mathbf{P} of the obstacles, and P\mathbf{P}-almost surely for a subsequence, towards a superprocess with underlying spatial motion given by Brownian motion and (inhomogeneous) branching mechanism ψ(u,x)\psi(u,x) of the form ψ(u,x)=u2+κ(x)u\psi(u,x)= u^2+ \kappa(x)u, where κ(x)\kappa(x) depends on the density of the obstacles. This work draws on similar questions for a single Brownian motion. In the course of the proof, we establish precise estimates for integrals of functions over the Wiener sausage, which are of independent interest.Comment: 22 page

    Economic Empowerment of Women in Lebanon

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    This research discusses the importance of the economic role of the working woman in Lebanon. It discusses the revolution of the changing role of the Lebanese woman from being a mother and a wife, to being an important contributor to the economic growth. It highlights the effective impact of this changing role on the family stability, following the Lebanese woman integration into the working force which results in decreasing the dependency on the male partner in providing essential family needs.Furthermore, this paper tackles the cultural differences among Lebanese women, the ambitions, the values, and the priorities of Lebanese women. It touches also on the economic empowerment of woman, who plays a significant role in facilitating the achievement of a higher level of economic welfare. However, the main focus of this paper is on the socio-economic role of the woman in the global environment where material needs have become a priority and an ultimate value.Questions which to be addressed by this paper are: should oriental women devote their lives to material gains even if it is done at the expense of the family life? How economically important to promote the women’s role as leaders and managers fully devoted to economic growth and money earnings? Are working women economically independent

    First malaria infections in a cohort of infants in Benin: biological, environmental and genetic determinants. Description of the study site, population methods and preliminary results

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    Objectives: Malaria infection of the placenta during pregnancy was found to be associated with infant susceptibility to malaria. Other factors such as the intensity of malaria transmission and the nutritional status of the child might also play a role, which has not been adequately taken into account in previous studies. The aim of this study was to assess precisely the parts played by environmental, nutritional and biological determinants in first malaria infections, with a special interest in the role of placental infection. The objective of this paper is not to present final results but to outline the rationale of the study, to describe the methods used and to report baseline data. Design: A cohort of infants followed with a parasitological (symptomatic and asymptomatic parasitaemia) and nutritional follow-up from birth to 18 months. Ecological, entomological and behavioural data were collected along the duration of the study. Setting: A rural area in Benin with two seasonal peaks in malaria transmission. Participants: 656 infants of women willing to participate in the study, giving birth in one of the three maternity clinics and living in one of the nine villages of the study area. Primary Outcome Measures: The time and frequency of first malaria parasitaemias in infants, according to Plasmodium falciparum infection of the placenta. Results: 11% of mothers had a malaria-infected placenta at delivery. Mosquito catches made every 6 weeks in the area showed an average annual P falciparum entomological inoculation rate of 15.5, with important time and space variations depending on villages. Similarly, the distribution of rainfalls, maximal during the two rainy seasons, was heterogeneous over the area. Conclusions: Considering the multidisciplinary approach of all factors potentially influencing the malaria status of newborn babies, this study should bring evidence on the implication of placental malaria in the occurrence of first malaria infections in infants

    The impact of integrated prevention and treatment on child malnutrition and health: the PROMIS project, a randomized control trial in Burkina Faso and Mali

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    Abstract Background Evidence suggests that both preventive and curative nutrition interventions are needed to tackle child acute malnutrition (AM) in developing countries. In addition to reducing the incidence of AM, providing preventive interventions may also help increase attendance (and coverage) of AM screening, a major constraint in the community-based management of child acute malnutrition (CMAM) model. There is a paucity of evidence-based strategies to deliver integrated preventive and curative interventions effectively and affordably at scale. The aim of the Innovative Approaches for the Prevention of Childhood Malnutrition (PROMIS) study is to assess the feasibility, quality of implementation, effectiveness and cost-effectiveness of an integrated child malnutrition prevention and treatment intervention package implemented through a community-based platform in Mali and a facility-based platform in Burkina Faso. Methods/Design The PROMIS intervention entails a comprehensive preventive package offered on a monthly basis to caregivers of children, while children are screened for acute malnutrition (AM). The package consists of behavior change communication on essential nutrition and hygiene actions, and monthly preventive doses of small quantity lipid-based nutrient supplements (SQ-LNS) for children aged 6 to 23.9 months. Positive AM cases are referred to treatment services offered by first-line health services according to the CMAM model. The PROMIS intervention will be evaluated using a mixed methods approach. The impact study encompasses two types of study design: i) repeated cross-sectional surveys conducted at baseline and at endline after 24 months of program implementation and ii) a longitudinal study with a monthly follow-up for 18 months. Primary study impact measures include the incidence and endpoint prevalence of AM, AM screening coverage and treatment compliance. A process evaluation will assess the feasibility and quality of implementation of the intervention guided by country specific program impact pathways (PIPs). Cost-effectiveness analysis will assess the economic feasibility of the intervention. Discussion The PROMIS study assesses the effectiveness of an innovative model to integrate prevention and treatment interventions for greater and more sustainable impacts on the incidence and prevalence of AM using a rigorous, theory-based randomized control trial approach. This type of programmatic research is urgently needed to help program implementers, policy makers, and investors prioritize, select and scale-up the best program models to prevent and treat AM and achieve the World Health Assembly goal of reducing childhood wasting to less than 5% globally by the year 2025. Trial registration Clinicaltrials.gov NCT02323815 (registered on December 18, 2014) and NCT02245152 (registered on September 16, 2014

    Development and validation of a RAD-Seq target-capture based genotyping assay for routine application in advanced black tiger shrimp (Penaeus monodon) breeding programs

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    Background: The development of genome-wide genotyping resources has provided terrestrial livestock and crop industries with the unique ability to accurately assess genomic relationships between individuals, uncover the genetic architecture of commercial traits, as well as identify superior individuals for selection based on their specific genetic profile. Utilising recent advancements in de-novo genome-wide genotyping technologies, it is now possible to provide aquaculture industries with these same important genotyping resources, even in the absence of existing genome assemblies. Here, we present the development of a genome-wide SNP assay for the Black Tiger shrimp (Penaeus monodon) through utilisation of a reduced-representation whole-genome genotyping approach (DArTseq). Results: Based on a single reduced-representation library, 31,262 polymorphic SNPs were identified across 650 individuals obtained from Australian wild stocks and commercial aquaculture populations. After filtering to remove SNPs with low read depth, low MAF, low call rate, deviation from HWE, and non-Mendelian inheritance, 7542 high-quality SNPs were retained. From these, 4236 high-quality genome-wide loci were selected for baits-probe development and 4194 SNPs were included within a finalized target-capture genotype-by-sequence assay (DArTcap). This assay was designed for routine and cost effective commercial application in large scale breeding programs, and demonstrates higher confidence in genotype calls through increased call rate (from 80.2 ± 14.7 to 93.0% ± 3.5%), increased read depth (from 20.4 ± 15.6 to 80.0 ± 88.7), as well as a 3-fold reduction in cost over traditional genotype-by-sequencing approaches. Conclusion: Importantly, this assay equips the P. monodon industry with the ability to simultaneously assign parentage of communally reared animals, undertake genomic relationship analysis, manage mate pairings between cryptic family lines, as well as undertake advance studies of genome and trait architecture. Critically this assay can be cost effectively applied as P. monodon breeding programs transition to undertaking genomic selection

    Dynamic study of blood-brain barrier closure after its disruption using ultrasound: a quantitative analysis.

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    International audienceDelivery of therapeutic or diagnostic agents to the brain is majorly hindered by the blood-brain barrier (BBB). Recently, many studies have demonstrated local and transient disruption of the BBB using low power ultrasound sonication combined with intravascular microbubbles. However, BBB opening and closure mechanisms are poorly understood, especially the maximum gap that may be safely generated between endothelial cells and the duration of opening of the BBB. Here, we studied BBB opening and closure under magnetic resonance (MR) guidance in a rat model. First, MR contrast agents (CA) of different hydrodynamic diameters (1 to 65 nm) were employed to estimate the largest molecular size permissible across the cerebral tissues. Second, to estimate the duration of the BBB opening, the CA were injected at various times post-BBB disruption (12 minutes to 24 hours). A T(1) mapping strategy was developed to assess CA concentration at the ultrasound (US) focal point. Based on our experimental data and BBB closure modeling, a calibration curve was obtained to compute the half closure time as a function of CA hydrodynamic diameter. These findings and the model provide an invaluable basis for optimal design and delivery of nanoparticles to the brain

    Best practice coral restoration for the Great Barrier Reef

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    As the Great Barrier Reef (GBR) continues to degrade through repeated mass bleaching events, crown-of-thorns starfish and major disease outbreaks, and the impacts of intense cyclones, pressure is growing for direct intervention to assist the recovery of reef-building corals. Decreasing coral cover on the GBR and other Australian reefs has been recognised as a serious problem relatively recently in Australia but follows a global trend, with many overseas reefs now highly degraded. Various types of coral restoration, rehabilitation and assisted recovery projects have been trialled overseas for decades and it makes sense to look at what has and hasn’t worked overseas to determine a range of options that may suit GBR conditions. Some direct interventions to assist coral recovery have been trialled in Australia such as transplanting corals, algae removal to promote coral recovery and larval enhancement promoting direct coral recruitment. In addition, after physical damage from cyclones, ship strikes or dragged anchors, local dive operators and dive clubs (permitted or unpermitted) often attempt to assist the recovery of corals by tipping over flipped tabular corals and reattaching broken branching corals or sea fans. These latter assisted recovery techniques are rarely underpinned by scientific data on coral recovery. A lack of best practice guidelines for these actions limits the chance of success and increases the health and safety risks of these activities
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