991 research outputs found
Occupational Activities and Cognitive Reserve: a Frontier Approach Applied to the Survey on Health, Ageing, and Retirement in Europe
The aim of this paper was to use a parametric stochastic frontier approach (coming from the economic literature) to explore the impact of the concept of activity (taken in a broad sense: i.e., including both professional and non-professional activities) on the constitution and the care of cognitive reserve among the European population aged 50 and up. For this purpose, we use individual data collected during the first wave of SHARE (Survey on Health, Ageing and Retirement in Europe) performed in 2004. The advantages of this survey were (1) it included a large population (n = 18,623) geographically distributed throughout Europe; and (2) it simultaneously analyzed several dimensions (physical and mental health, mobility, occupational activities, socioeconomic status, etc.). Our results confirm the positive impact of occupational activities on the cognitive functioning of elderly people. These results are discussed in terms of the prevention of cognitive aging and Alzheimer’s disease, and more particularly of retirement policy issues.
Étude exploratoire des représentations des filles à l’égard des sciences et de la technologie au secondaire
Encore aujourd’hui, des positions diverses fusent quant à une problématique qui ne date pas d’hier : le manque d’intérêt des jeunes pour les sciences et la technologie (S et T). En effet, il semble que l’école ne réussisse pas à inculquer aux jeunes le goût de poursuivre des études postsecondaires vers les domaines technoscientifiques et cette problématique se rencontre plus particulièrement chez les filles (Gaudet, Mujawamariya et Lapointe, 2008 ; GERSO, 2004 ; Lafortune, Deaudelin, Doudin et Martin, 2003 ; Lafortune et Solar, 2003 ; OCDE, 2006 ; PISA, 2006 ; Samson, 2011). Au Québec, comme ailleurs dans le monde, la relève est rarissime dans plusieurs secteurs : sciences, technologies, ingénierie et mathématiques (STIM). Pourtant, des études en S et T au niveau collégial et universitaire donnent accès à un vaste éventail de métiers et de professions offrant de très bonnes conditions de travail.
Cette désaffection est davantage percutante chez les filles qui ont toujours cette tendance à privilégier certains domaines traditionnellement féminins2, et ce, en dépit des efforts et de la sensibilisation à des carrières dites traditionnellement masculines. La société québécoise a évolué depuis plusieurs décennies, l’égalité et l’équité sociales ont pris tout leur sens, mais les femmes occupent encore très peu de postes présentant un haut niveau de responsabilités (Lacroix, 2002, dans Lafortune et Solar, 2003). De surcroît, certaines filières en S et T reste encore suffisamment cantonnée de façon traditionnelle pour en faire des regroupements strictement féminins, notamment l’enseignement, les sciences infirmières et le domaine de la médecine. En rétrospective, on peut dire que le domaine de la santé est un secteur très féminisé et que le domaine du génie demeure très masculinisé (Gouvernement du Canada, 2010a). Il semble donc que les croyances, les préjugés et les stéréotypes véhiculés par la société jouent un rôle important dans le contexte actuel sous-jacent aux choix des filles qui optent pour le domaine de la santé ou de l’ensemble des domaines du travail reliés à une sectorisation (Gaudet et al., 2008 ; James, 2011 ; Lafortune et Solar, 2003 ; Lafortune et al., 2003). D’ailleurs, les influences sociales, familiales et scolaires, ainsi que les caractéristiques individuelles sont en prendre en compte dans l’établissement des représentations, et des attitudes qu’adoptent les jeunes filles à l’égard des S et T (Gaudet et al., 2008). En fait, les construits sociaux se modélisent tout au long du parcours scolaire et amènent les filles à adopter des attitudes plus négatives à l’égard des S et T. Les filles manquent de confiance en elles et de modèles féminins pour les accompagner vers les filières non traditionnelles. Dans bien des cas, les Québécoises réussissent aussi bien que les garçons en S et T, mais elles se retrouvent moins nombreuses dans les programmes d’études postsecondaires reliés aux STIM (Gaudet et al., 2008 ; Gouvernement du Canada, 2010a ; Lafortune et Solar, 2003 ; Lafortune et al., 2003).
En ce sens, le présent essai explore les représentations et les attitudes qu’entretiennent les filles à l’égard des S et T, au vu de leur choix de carrière. Cette étude s’est réalisée dans un établissement secondaire québécois non mixte, en première et deuxième année du deuxième cycle. Soulignons ici que la population à l’étude en provenance d’un collège privé est privilégiée tant par l’environnement éducatif que par son milieu socioéconomique. Ainsi, notre analyse des résultats révèle des éléments émergents très positifs quant aux différents aspects concernant l’intérêt des filles pour les S et T. Cependant, leur choix de carrière est manifestement marqué par le domaine de la santé
Retraite, activités non professionnelles et vieillissement cognitif. Une exploration à partir des données de Share
peer reviewedUne approche en termes de frontières d’effi cacité peut être utilisée pour étudier les relations
entre les fonctions cognitives des personnes âgées de plus de 50 ans en Europe
d’une part, et différents facteurs, plus particulièrement l’âge, l’éducation et l’exercice
d’activités, professionnelles ou non, d’autre part. Le but est de construire une « frontière
» correspondant au fonctionnement cognitif optimal que chacun des individus est
censé atteindre étant donné son âge et son niveau d’éducation. À cette fi n, nous utilisons
des données individuelles collectées durant la première vague de l’enquête internationale
et interdisciplinaire Share de 2004, laquelle contient le résultat de tests cognitifs
réalisés auprès de plus de 22 000 individus âgés, ainsi que des informations sur leur état
de santé, mentale et physique, leur situation socio-économique, leur entourage familial,
l’exercice d’activités professionnelles ou non professionnelles, l’isolement social et les
performances cognitives individuelles mesurées à l’aide de tests. En plus du rôle fondamental
joué par l’éducation face au vieillissement cognitif, le fait de rester en activité,
ainsi que la pratique d’une activité non professionnelle ou d’activités physiques, vigoureuses
ou modérées, sont positivement associés à la constitution des « réserves cognitives
» individuelles. La mise à disposition des données des vagues successives de Share ,
prévues tous les deux ans auprès des mêmes individus, pourrait permettre de déterminer
les liens de causalité subjacents
Retirement and cognitive reserve: a stochastic frontier approach applied to survey data
This paper proposes the use of the stochastic frontier approach to analyse the relationship
between cognitive performance, retirement and non-professional activities of the 50+
individuals using data from three surveys conducted in Europe (the Survey on Health,
Ageing and Retirement in Europe and the English Longitudinal Survey on Ageing) and
United States (the Health and Retirement Study). Next to the strong relationship between
cognitive performance, age and education, this study highlights the negative effect of
retirement and the positive impact of non-professional activities and social contacts
Retirement, Non-Professional Activities and Cognitive Ageing. An investigation Based on Share Data,
We apply frontier analysis tools to study the relationship between cognitive functioning and factors like age, education and occupational activities, professional or not, among individuals aged 50 year and more in Europe. We use individual data collected in the first wave of Share in 2004. Other than data on cognitive tests, Share contains detailed information on health status, socioeconomic characteristics and family composition for more than 22,000 individuals. The results highlight that, other than the main role played by education in cognitive ageing prevention, also delaying retirement, the practice of non-professional activities and moderate or vigorous physical activities are positively related to the constitution of individuals cognitive reserve. This is a first step in the study of these relations using Share. A deeper analysis, allowing to assess the causality links underlying these relationships, would be possible when the next waves of Share, conducted every two-year on the same individuals, will be available.Cognitive Ageing, Retirement, Non-Professional Activities, Stochastic Frontier
Occupational Activities and Cognitive Reserve: a Frontier Approach Applied to the Survey on Health, Ageing, and Retirement in Europe (SHARE)
The aim of this paper was to use a parametric stochastic frontier approach
(coming from the economic literature) to explore the impact of the concept of activity
(taken in a broad sense: i.e., including both professional and non-professional activities)
on the constitution and the care of cognitive reserve among the European population
aged 50 and up. For this purpose, we use individual data collected during the first wave
of SHARE (Survey on Health, Ageing and Retirement in Europe) performed in 2004.
The advantages of this survey were (1) it included a large population (n = 18,623)
geographically distributed throughout Europe; and (2) it simultaneously analyzed
several dimensions (physical and mental health, mobility, occupational activities,
socioeconomic status, etc.). Our results confirm the positive impact of occupational
activities on the cognitive functioning of elderly people. These results are discussed in
terms of the prevention of cognitive aging and Alzheimer’s disease, and more
particularly of retirement policy issues
Protein Antigens Increase the Protective Efficacy of a Capsule-Based Vaccine against Staphylococcus aureus in a Rat Model of Osteomyelitis
Staphylococcus aureus is an invasive bacterial pathogen, and antibiotic resistance has impeded adequate control of infections caused by this microbe. Moreover, efforts to prevent human infections with single-component S. aureus vaccines have failed. In this study, we evaluated the protective efficacy in rats of vaccines containing both S. aureus capsular polysaccharides (CPs) and proteins. The serotypes 5 CP (CP5) and 8 CP (CP8) were conjugated to tetanus toxoid and administered to rats alone or together with domain A of clumping factor A (ClfA) or genetically detoxified alpha-toxin (dHla). The vaccines were delivered according to a preventive or a therapeutic regimen, and their protective efficacy was evaluated in a rat model of osteomyelitis. Addition of dHla (but not ClfA) to the CP5 or CP8 vaccine induced reductions in bacterial load and bone morphological changes compared with immunization with either conjugate vaccine alone. Both the prophylactic and therapeutic regimens were protective. Immunization with dHla together with a pneumococcal conjugate vaccine used as a control did not reduce staphylococcal osteomyelitis. The emergence of unencapsulated or small-colony variants during infection was negligible and similar for all of the vaccine groups. In conclusion, addition of dHla to a CP5 or CP8 conjugate vaccine enhanced its efficacy against S. aureus osteomyelitis, indicating that the inclusion of multiple antigens will likely enhance the efficacy of vaccines against both chronic and acute forms of staphylococcal disease.Fil: Lattar, Santiago Martín. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Noto Llana, Mariangeles. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Denoël, Philippe. GlaxoSmithKline Vaccines; BélgicaFil: Germain, Sophie. GlaxoSmithKline Vaccines; BélgicaFil: Buzzola, Fernanda Roxana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Lee, Jean C.. Harvard Medical School; Estados UnidosFil: Sordelli, Daniel Oscar. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin
Regulation of COX-2 protein expression by Akt in endometrial cancer cells is mediated through NF-κB/IκB pathway
BACKGROUND: Cyclooxygenase-2 (COX-2) has been shown to be highly expressed in a broad series of primary endometrial tumors and its expression may be closely associated with parameters of tumor aggressiveness. In human endometrial cancer, tumor suppressor phosphatase tensin homologue (PTEN) is frequently mutated. In the presence of a mutated PTEN protein, Akt phosphorylation levels increase leading to the activation of this survival pathway. The nuclear transcription factor κB (NF-κB) is a well establish regulator of genes encoding cytokines, cytokine receptors, and cell adhesion molecules that drive immune and inflammatory responses. More recently, NF-κB activation has been connected with multiple aspects of oncogenesis, including the control of apoptosis, cell cycle, differentiation, and cell migration. It is known that Akt may act through NF-κB pathway and that COX-2 gene has been shown to be regulated at the promoter level by NF-κB. Recently, we showed that Akt regulates COX-2 gene and protein expressions in phospho-Akt expressing endometrial cancer cells. The present study was undertaken to determine the involvement of NF-κB pathway and IκB (an inhibitor of NF-κB) in the regulation of COX-2 expression and to determine more precisely the downstream targets of Akt involved in this process. RESULTS: Three different human endometrial cancer cell lines known to have wild type PTEN (HEC 1-A) or a mutated inactive PTEN protein (RL 95-2 and Ishikawa) were used for these studies. Expression IκB and Phospho-IκB were evaluated by Western analysis. The presence of IκB phosphorylation was found in all cell lines studied. There was no difference between cell lines in term of NF-κB abundance. Inhibition of PI 3-K with Wortmannin and LY294002 blocked IκB phosphorylation, reduced NF-κB nuclear activity, reduced COX-2 expression and induced apoptosis. Transfection studies with a dominant negative Akt vector blocked IκB phosphorylation and reduced COX-2 expression. On the opposite, constitutively active Akt transfections resulted in the induction of IκB phosphorylation and up-regulation of COX-2. CONCLUSION: These results demonstrate that Akt signals through NF-κB/IκB pathway to induce COX-2 expression in mutated PTEN endometrial cancer cells
Contribution of X-ray CMT and image processing to the modelling of pyrocarbon Chemical Vapour Infiltration
International audienceThe Chemical Vapour Infiltration (CVI) process is used to fabricate the pyrocarbon matrices of C/C composites. This process involves complex physico-chemical phenomena such as the transport of precursor, carrier, and by-product gases in the reactor and inside a fibrous preform, heat transfer, chemical reactions (pyrolysis and deposition), and the structural evolution of the preform. It is able to provide high-quality materials because the processing conditions are rather mild with respect to the fibres; however it is expensive and sometimes difficult to optimize. This process has been the object of extensive modelling efforts, because of imperative optimization needs. The present work presents an approach suited to the exploitation of computerized microtomographs of C/C composites, which features image acquisition, computation of geometrical and transport properties, and infiltration modelling, as applied to the infiltration of needled carbon fibre fabrics. Another application to the reinforcement of carbon foams is also presented, as an example of inserting this approach in a global modelling strategy
Viscosity solution of Hamilton-Jacobi equation by a limiting minmax method
For non convex Hamiltonians, the viscosity solution and the more geometric
minimax solution of the Hamilton-Jacobi equation do not coincide in general.
They are nevertheless related: we show that iterating the minimax procedure
during shorter and shorter time intervals one recovers the viscosity solution.Comment: 27 page
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