137 research outputs found
A Comparison of Parent and Teacher Ratings of Child Behaviours: the Pygmalion Effect Revisited
Early schooling experience is a reliable predictor of later school and professional adjustment. In the context of important investment made in the preschool curriculum to promote early academic achievement among children at risk of failure, the validity of screening and referring procedures is a rising issue. 384 children and their family participated in an 18 months longitudinal study from kindergarten to first grade. Results of the present study confirmed the value of screening protocol based on consensus between parents and teacher for greater attention to children needs. However, further results suggested that kindergarten’ teachers might be considered as a unique and valid informant to predict early academic achievement
Dominance et hiérarchie dans une classe d'intégration de niveau préscolaire : une approche éthologique
Trace metal concentrations in Posidonia oceanica of North Corsica (northwestern Mediterranean Sea): use as a biological monitor?
BACKGROUND: Within semi-closed areas like the Mediterranean Sea, anthropic wastes tend to concentrate in the environment. Metals, in particular, are known to persist in the environment and can affect human health due to accumulation in the food chain. The seagrass Posidonia oceanica, widely found in Mediterranean coastal waters, has been chosen as a "sentinel" to quantify the distribution of such pollutants within the marine environment. Using a technique similar to dendrochronology in trees, it can act as an indicator of pollutant levels over a timeframe of several months to years. In the present study, we measured and compared the levels of eight trace metals (Cr, Ni, Cu, Zn, As, Se, Cd, and Pb) in sheaths dated by lepidochronology and in leaves of shoots sampled from P. oceanica meadows collected from six offshore sites in northern Corsica between 1988 and 2004; in the aim to determine 1) the spatial and 2) temporal variations of these metals in these areas and 3) to compared these two types of tissues. RESULTS: We found low trace metal concentrations with no increase over the last decade, confirming the potential use of Corsican seagrass beds as reference sites for the Mediterranean Sea. Temporal trends of trace metal concentrations in sheaths were not significant for Cr, Ni, Cu, As or Se, but Zn, Cd, and Pb levels decreased, probably due to the reduced anthropic use of these metals. Similar temporal trends between Cu levels in leaves (living tissue) and in sheaths (dead tissue) demonstrated that lepidochronology linked with Cu monitoring is effective for surveying the temporal variability of this metal. CONCLUSION: Leaves of P. oceanica can give an indication of the metal concentration in the environment over a short time period (months) with good accuracy. On the contrary, sheaths, which gave an indication of changes over long time periods (decades), seem to be less sensitive to variations in the metal concentration in the environment. Changes in human consumption of metals (e.g., the reduction of Pb in fuel) are clearly reflected in both organs. These results confirm that P. oceanica is a good bioindicator of metals and a good biomonitor species for assessing Cu in the environment
Enhancing genetic mapping of complex genomes through the design of highly-multiplexed SNP arrays: application to the large and unsequenced genomes of white spruce and black spruce
<p>Abstract</p> <p>Background</p> <p>To explore the potential value of high-throughput genotyping assays in the analysis of large and complex genomes, we designed two highly multiplexed Illumina bead arrays using the GoldenGate SNP assay for gene mapping in white spruce (<it>Picea glauca </it>[Moench] Voss) and black spruce (<it>Picea mariana </it>[Mill.] B.S.P.).</p> <p>Results</p> <p>Each array included 768 SNPs, identified by resequencing genomic DNA from parents of each mapping population. For white spruce and black spruce, respectively, 69.2% and 77.1% of genotyped SNPs had valid GoldenGate assay scores and segregated in the mapping populations. For each of these successful SNPs, on average, valid genotyping scores were obtained for over 99% of progeny. SNP data were integrated to pre-existing ALFP, ESTP, and SSR markers to construct two individual linkage maps and a composite map for white spruce and black spruce genomes. The white spruce composite map contained 821 markers including 348 gene loci. Also, 835 markers including 328 gene loci were positioned on the black spruce composite map. In total, 215 anchor markers (mostly gene markers) were shared between the two species. Considering lineage divergence at least 10 Myr ago between the two spruces, interspecific comparison of homoeologous linkage groups revealed remarkable synteny and marker colinearity.</p> <p>Conclusion</p> <p>The design of customized highly multiplexed Illumina SNP arrays appears as an efficient procedure to enhance the mapping of expressed genes and make linkage maps more informative and powerful in such species with poorly known genomes. This genotyping approach will open new avenues for co-localizing candidate genes and QTLs, partial genome sequencing, and comparative mapping across conifers.</p
COMPETITIVE OR WEAK COOPERATIVE STOCHASTIC LOTKA-VOLTERRA SYSTEMS CONDITIONED TO NON-EXTINCTION
International audienceWe are interested in the long time behavior of a two-type density-dependent biological population conditioned to non-extinction, in both cases of competition or weak cooperation between the two species. This population is described by a stochastic Lotka-Volterra system, obtained as limit of renormalized interacting birth and death processes. The weak cooperation assumption allows the system not to blow up. We study the existence and uniqueness of a quasi-stationary distribution, that is convergence to equilibrium conditioned to non extinction. To this aim we generalize in two-dimensions spectral tools developed for one-dimensional generalized Feller diffusion processes. The existence proof of a quasi-stationary distribution is reduced to the one for a -dimensional Kolmogorov diffusion process under a symmetry assumption. The symmetry we need is satisfied under a local balance condition relying the ecological rates. A novelty is the outlined relation between the uniqueness of the quasi-stationary distribution and the ultracontractivity of the killed semi-group. By a comparison between the killing rates for the populations of each type and the one of the global population, we show that the quasi-stationary distribution can be either supported by individuals of one (the strongest one) type or supported by individuals of the two types. We thus highlight two different long time behaviors depending on the parameters of the model: either the model exhibits an intermediary time scale for which only one type (the dominant trait) is surviving, or there is a positive probability to have coexistence of the two species
GNB: Projet de recherche finalisée à l’interface recherche-gestion et ses interactions avec BGF
La gestion durable des forêts repose largement sur la biodiversité dont le fonctionnement reste cependant encore très insuffisamment connu. Il en découle la nécessité d’améliorer, de manière générale, le socle de connaissances relatif à la biodiversité et, plus particulièrement, d’analyser les interactions entre changement climatique, productivité forestière et biodiversité en forêt. Par ailleurs, les stratégies et décisions des acteurs influent sur ces interactions et constituent également des objets d’étude à privilégier. C’est pourquoi le programme de recherche « Biodiversité, gestion forestière et politiques publiques » a lancé en 2013 un appel à projets de recherche avec deux entrées :
- l’une par les sciences de la nature axée sur le changement climatique, les mesures de gestion et la dynamique de la biodiversité dans les écosystèmes ;
- l’autre par les sciences humaines et sociales sur les stratégies et décisions des acteurs, la gouvernance et les politiques publiques correspondant à la première entrée.
Le présent colloque a pour objectifs de :
- présenter les résultats des cinq projets de recherche qui ont été sélectionnés à cette occasion sur chacune des deux entrées en les accompagnant en tant que de besoin de regards complémentaires et en illustrant l’un des projets par une visite sur le terrain ;
- initier une réflexion sur le progrès des connaissances dans ce domaine, en s’inspirant du devenir de projets antérieurs et en identifiant les principales lacunes à combler.
Il se déroulera en trois sessions, chacune introduite par des exposés d’une quinzaine de minutes et conclue par une table ronde permettant un débat avec les participants et les invités
Remote Sensing Image Representation based on Hierarchical Histogram Propagation
International audienceMany methods have been recently proposed to deal with the large amount of data provided by high- resolution remote sensing technologies. Several of these methods rely on the use of image segmentation algorithms for delineating target objects. However, a common issue in geographic object-based applications is the definition of the appropriate data representation scale, a problem that can be addressed by exploiting multiscale segmentation. The use of multiple scales, however, raises new challenges related to the definition of effective and efficient mechanisms for extracting features. In this paper, we address the problem of extracting histogram-based features from a hierarchy of regions for multiscale classification. The strategy, called H-Propagation, exploits the existing relation- ships among regions in a hierarchy to iteratively prop- agate features along multiple scales. The proposed method speeds up the feature extraction process and yields good results when compared with global low- level extraction approaches
Approaches to considering sex and gender in continuous professional development for health and social care professionals : an emerging paradigm
Consideration of sex and gender in research and clinical practice is necessary to redress health inequities and reduce knowledge gaps. As all health professionals must maintain and update their skills throughout their career, developing innovative continuing professional education programs that integrate sex and gender issues holds great promise for reducing these gaps. This article proposes new approaches to partnership, team development, pedagogical theory, content development, evaluation and data management that will advance the integration of sex and gender in continuing professional development (CPD). Our perspectives build on an intersectoral and interprofessional research team that includes several perspectives, including those of CPD, health systems, knowledge translation and sex and gender
LILAC pilot study : effects of metformin on mTOR activation and HIV reservoir persistence during antiretroviral therapy
Background: Chronic inflammation and residual HIV transcription persist in people living with HIV (PLWH)
receiving antiretroviral therapy (ART), thus increasing the risk of developing non-AIDS co-morbidities. The
mechanistic target of rapamycin (mTOR) is a key regulator of cellular metabolism and HIV transcription, and
therefore represents an interesting novel therapeutic target.
Methods: The LILAC pilot clinical trial, performed on non-diabetic ART-treated PLWH with CD4+
/CD8+ T-cell
ratios <0.8, evaluated the effects of metformin (12 weeks oral administration; 500-850 mg twice daily), an
indirect mTOR inhibitor, on the dynamics of immunological/virological markers and changes in mTOR activation/phosphorylation in blood collected at Baseline, Week 12, and 12 weeks after metformin discontinuation
(Week 24) and sigmoid colon biopsies (SCB) collected at Baseline and Week 12.
Findings: CD4+ T-cell counts, CD4+
/CD8+ T-cell ratios, plasma markers of inflammation/gut damage, as well as
levels of cell-associated integrated HIV-DNA and HIV-RNA, and transcriptionally-inducible HIV reservoirs,
underwent minor variations in the blood in response to metformin. The highest levels of mTOR activation/
phosphorylation were observed in SCB at Baseline. Consistently, metformin significantly decreased CD4+ Tcell infiltration in the colon, as well as mTOR activation/phosphorylation, especially in CD4+ T-cells expressing the Th17 marker CCR6. Also, metformin decreased the HIV-RNA/HIV-DNA ratios, a surrogate marker of
viral transcription, in colon-infiltrating CD4+ T-cells of 8/13 participants
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