299 research outputs found
Plate theory as the variational limit of the complementary energy functionals of inhomogeneous anisotropic linearly elastic bodies
We consider a sequence of linear hyper-elastic, inhomogeneous and fully
anisotropic bodies in a reference configuration occupying a cylindrical region
of height epsilon. We then study, by means of Gamma-convergence, the asymptotic
behavior as epsilon goes to zero of the sequence of complementary energies. The
limit functional is then identified as a dual problem for a two-dimensional
plate. Our approach gives a direct characterization of the convergence of the
equilibrating stress fields
Asymptotic behavior of an elastic beam fixed on a small part of one of its extremities
We study the asymptotic behavior of the solution of an anisotropic,
heterogeneous, linearized elasticity problem in a cylinder whose diameter
tends to zero. The cylinder is assumed to be fixed (homogeneous
Dirichlet boundary condition) on the whole of one of its extremities, but only
on a small part (of size ) of the second one; the Neumann
boundary condition is assumed on the remainder of the boundary. We show that
the result depends on , and that there are 3 critical sizes, namely
, , and
, and in total 7 different regimes. We also prove a
corrector result for each behavior of .Comment: Preliminary version of a Note to be published in a slightly
abbreviated form in C. R. Acad. Sci. Paris, Ser. I, 338 (2004), pp. 975-98
Junction of elastic plates and beams (Preliminary version)
We consider the linearized elasticity system in a multidomain of the three
dimensional space. This multidomain is the union of a horizontal plate, with
fixed cross section and small thickness "h", and of a vertical beam with fixed
height and small cross section of radius "r". The lateral boundary of the plate
and the top of the beam are assumed to be clamped. When "h" and "r" tend to
zero simultaneously, with "r" much greater than the square of "h", we identify
the limit problem. This limit problem involves six junction conditions.Comment: Ceci est la redaction du 3 Mars 2003. Francois Murat souhaite y faire
des modification
Recent advances in modelling and simulation of surface integrity in machining - A review
Machining is one of the final steps in the manufacturing value chain, where the dimensional tolerances are fine-tuned, and the functional surfaces are generated. Many factors such as the process type, cutting parameters, tool geometry and wear can influence the surface integrity (SI) in machining. Being able to predict and monitor the influence of different parameters on surface integrity provides an opportunity to produce surfaces with predetermined properties. This paper presents an overview of the recent advances in computational and artificial intelligence methods for modelling and simulation of surface integrity in machining and the future research and development trends are highlighted
Deciphering the genome structure and paleohistory of _Theobroma cacao_
We sequenced and assembled the genome of _Theobroma cacao_, an economically important tropical fruit tree crop that is the source of chocolate. The assembly corresponds to 76% of the estimated genome size and contains almost all previously described genes, with 82% of them anchored on the 10 _T. cacao_ chromosomes. Analysis of this sequence information highlighted specific expansion of some gene families during evolution, for example flavonoid-related genes. It also provides a major source of candidate genes for _T. cacao_ disease resistance and quality improvement. Based on the inferred paleohistory of the T. cacao genome, we propose an evolutionary scenario whereby the ten _T. cacao_ chromosomes were shaped from an ancestor through eleven chromosome fusions. The _T. cacao_ genome can be considered as a simple living relic of higher plant evolution
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
Natalizumab, Fingolimod and Dimethyl Fumarate Use and Pregnancy-Related Relapse and Disability in Women With Multiple Sclerosis
To investigate pregnancy-related disease activity in a contemporary multiple sclerosis (MS) cohort
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