Prospectives

Tiré de: Prospectives, vol. 17, no 4, déc. 1981Titre de l'écran-titre (visionné le 24 janv. 2013

Identité ethnique à l’adolescence : perspectives interculturelles

Comme suite à la traduction française et à l'adaptation (Tremblay, Corbière, Perron, & Coallier, 2000) du Multigroup Ethnic Identity Measure (Phinney, 1992), cette étude vise à reproduire, avec des groupes d'élèves québécois du cursus secondaire, les conclusions de travaux réalisés aux États-Unis avec des groupes analogues. Les résultats de trois types d'analyses (développemental, différentiel, corrélationnel) sont la plupart du temps semblables à ceux des études américaines et permettent de conclure que la Mesure d'Identité Ethnique (M.I.E. ; Perron & Coallier, 1992) est valide et pourrait servir à mieux comprendre le processus de la formation de l'identité ethnique d'élèves de divers groupes culturels dans les pays de la francophonie.Following the translation and adaptation (Tremblay, Corbière, Perron, & Coallier, 2000) of the Multigroup Ethnic Identity Measure (M.E.LM. ; Phinney, 1992), this study aimed at replicating, with high school Québécois students, the conclusions of researches petformed in the United States with analogue groups. Results from three types of analyses (developmental, differential, and correlational) were mostly similar to those of the American studies and lent support for the conclusion that the Mesure d'Identité Ethnique (M.LE. ; Perron & Coallier, 1992) is a valid instrument and could help to further understand the process of ethnic identity formation among students of diverse ethnic groups within French-speaking countries

Detection and Quantification of Microparticles from Different Cellular Lineages Using Flow Cytometry. Evaluation of the Impact of Secreted Phospholipase A2 on Microparticle Assessment

Microparticles, also called microvesicles, are submicron extracellular vesicles produced by plasma membrane budding and shedding recognized as key actors in numerous physio(patho)logical processes. Since they can be released by virtually any cell lineages and are retrieved in biological fluids, microparticles appear as potent biomarkers. However, the small dimensions of microparticles and soluble factors present in body fluids can considerably impede their quantification. Here, flow cytometry with improved methodology for microparticle resolution was used to detect microparticles of human and mouse species generated from platelets, red blood cells, endothelial cells, apoptotic thymocytes and cells from the male reproductive tract. A family of soluble proteins, the secreted phospholipases A2 (sPLA2), comprises enzymes concomitantly expressed with microparticles in biological fluids and that catalyze the hydrolysis of membrane phospholipids. As sPLA2 can hydrolyze phosphatidylserine, a phospholipid frequently used to assess microparticles, and might even clear microparticles, we further considered the impact of relevant sPLA2 enzymes, sPLA2 group IIA, V and X, on microparticle quantification. We observed that if enriched in fluids, certain sPLA2 enzymes impair the quantification of microparticles depending on the species studied, the source of microparticles and the means of detection employed (surface phosphatidylserine or protein antigen detection). This study provides analytical considerations for appropriate interpretation of microparticle cytofluorometric measurements in biological samples containing sPLA2 enzymes

Les sociétés populaires à travers leurs procès-verbaux

Sous la Révolution française, les sociétés populaires ont créé et animé des réseaux de sociabilité politique dont leurs procès-verbaux sont des témoins. Ces délibérations sont des sources remarquables que la collection des "Documents inédits sur l’histoire de France", publiée sous l’égide du Comité des travaux historiques et scientifiques, permet de redécouvrir. Les études réunies dans cet ouvrage nous invitent à mieux comprendre le fonctionnement des sociétés populaires et à mesurer l’importance de leurs archives pour l’histoire politique et sociale

Isothermal and Cyclic Aging of 310S Austenitic Stainless Steel

Unusual damage and high creep strain rates have been observed on components made of 310S stainless steel subjected to thermal cycles between room temperature and 1143 K (870 °C). Microstructural characterization of such components after service evidenced high contents in sigma phase which formed first from δ-ferrite and then from γ-austenite. To get some insight into this microstructural evolution, isothermal and cyclic aging of 310S stainless steel has been studied experimentally and discussed on the basis of numerical simulations. The higher contents of sigma phase observed after cyclic agings than after isothermal treatments are clearly associated with nucleation triggered by thermal cycling

Normalisation to Blood Activity Is Required for the Accurate Quantification of Na/I Symporter Ectopic Expression by SPECT/CT in Individual Subjects

The utilisation of the Na/I symporter (NIS) and associated radiotracers as a reporter system for imaging gene expression is now reaching the clinical setting in cancer gene therapy applications. However, a formal assessment of the methodology in terms of normalisation of the data still remains to be performed, particularly in the context of the assessment of activities in individual subjects in longitudinal studies. In this context, we administered to mice a recombinant, replication-incompetent adenovirus encoding rat NIS, or a human colorectal carcinoma cell line (HT29) encoding mouse NIS. We used 99mTc pertechnetate as a radiotracer for SPECT/CT imaging to determine the pattern of ectopic NIS expression in longitudinal kinetic studies. Some animals of the cohort were culled and NIS expression was measured by quantitative RT-PCR and immunohistochemistry. The radioactive content of some liver biopsies was also measured ex vivo. Our results show that in longitudinal studies involving datasets taken from individual mice, the presentation of non-normalised data (activity expressed as %ID/g or %ID/cc) leads to ‘noisy’, and sometimes incoherent, results. This variability is due to the fact that the blood pertechnetate concentration can vary up to three-fold from day to day. Normalisation of these data with blood activities corrects for these inconsistencies. We advocate that, blood pertechnetate activity should be determined and used to normalise the activity measured in the organ/region of interest that expresses NIS ectopically. Considering that NIS imaging has already reached the clinical setting in the context of cancer gene therapy, this normalisation may be essential in order to obtain accurate and predictive information in future longitudinal clinical studies in biotherapy

The hedgehog pathway and ocular developmental anomalies.

Mutations in effectors of the hedgehog signaling pathway are responsible for a wide variety of ocular developmental anomalies. These range from massive malformations of the brain and ocular primordia, not always compatible with postnatal life, to subtle but damaging functional effects on specific eye components. This review will concentrate on the effects and effectors of the major vertebrate hedgehog ligand for eye and brain formation, Sonic hedgehog (SHH), in tissues that constitute the eye directly and also in those tissues that exert indirect influence on eye formation. After a brief overview of human eye development, the many roles of the SHH signaling pathway during both early and later morphogenetic processes in the brain and then eye and periocular primordia will be evoked. Some of the unique molecular biology of this pathway in vertebrates, particularly ciliary signal transduction, will also be broached within this developmental cellular context