Sales--Implied Warranties--Requirement of a Sale

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Statistical Modelling of Cardiovascular Data. An Introduction to Linear Mixed Models

Most of statistical approaches in cardiovascular research were based on variance analysis (ANOVA). However, most of the time, the assumption that data are independent is violated since several measures are performed on the same subject (repeated measures). In addition, the presence of intra- and inter-observers variability can potentially obscure significant differences. The linear mixed model (LMM) is an extended multivariate linear regression method of analysis that accounts for both fixed and random effects. LMM allows for addressing incomplete design cases. In this paper, LMM was applied to two sets of cardiovascular research data and compared to ANOVA. The first example is an analysis of heart rate in mice after atropine and propranolol injections. LMM shows an important mouse random effects that depends on pharmacological treatment and provides with accurate estimates for each significant experimental factors. When randomly suppressing observations from the data sets (20-30%) the time factor of Anova model becomes non significant while LMM still remains significant. The second example is the analysis of isolated coronary-perfused pressure of transgenic mice hearts. LMM evidenced a significant transgenic effect in both male and female animals, while, with ANOVA, the transgenic effects was limited to male mice only. In both cases, as compared to ANOVA, the LMM separately accounts for fixed and random effects, allowing thus for studying more adequately incomplete designs on repeated measures

The recent evolution of management strategies of invasive plants on Réunion Island

The important issue of plant invasions on Réunion Island necessitates a rapid upskilling of relevant institutional actors and land users. There is a need to balance diverse viewpoints and interests in order to open the way for broad-based, multi-stakeholder actions against invasive plants. A consensus is emerging in favour of preventive actions that regulate introduction pressures, and in favour of rapid intervention in new invasion sites. At the same time, people are taking more of a landscape level view of the invasion process. It is at this scale that agriculture, animal husbandry and forestry are being called upon to reduce their environmental externalities, notably by better controlling invasive plants upon which these industries rely. In the wake of the creation in 2007 of the new National Park "Parc National des Hauts de La Réunion", there is an increasing effort at finding reciprocally beneficial approaches that solve the numerous conflicts of interest over invasive species. On the other hand, the private sector remains insufficiently implicated as a partner in such management programsLe caractère préoccupant des invasions de plantes à l'île de La Réunion exige un apprentissage rapide et concerté de la part de l'ensemble des acteurs institutionnels et des usagers. La diversité de regards et d'intérêts enjeu nécessite d'être conciliée pour dégager des compromis d'actions et des programmes de lutte s'appuyant sur des dynamiques partenariales. Un consensus émerge en faveur d'actions préventives régulant la pression d'introduction ou permettant d'intervenir rapidement sur les nouveaux foyers d'invasion. Parallèlement, les processus d'invasion sont de plus en plus envisagés à l'échelle des paysages. C'est à cette même échelle que l'agriculture, l'élevage et la production sylvicole sont appelés à réduire leurs externalités environnementales, notamment par le jeu d'un meilleur contrôle des invasions de plantes dans lesquelles ils sont impliqués. Une forte mutualisation des actions de lutte contre les invasions végétales est en cours, dans le sillage immédiat de la constitution du Parc National des Hauts de La Réunion en 2007, et dans la perspective d'une meilleure résolution des nombreux conflits d'intérêts. En revanche, il est manifeste que le secteur privé reste insuffisamment impliqué en tant que partenaire privilégié, de tels programmes d'intervention

Peptide-protein microarrays and surface plasmon resonance detection: biosensors for versatile biomolecular interaction analysis.

International audienceBiosensors in microarray format provide promising tools for high-throughput analyses of complex samples. Although they are able to detect, quantify and characterize a multitude of compounds, most of the available devices are specialized in the analysis of one type of interaction, limiting their application to a define area. The aim of our work was to develop and characterize versatile protein (or peptide) microarrays suitable for the simultaneous analysis of a large panel of biological interactions. Our system involved a simple procedure to immobilized proteins or peptides, based on pyrrole electropolymerization, and ligand binding was detected by imaging the surface plasmon resonance. We demonstrated its suitability in three different contexts, i.e. humoral response characterization, ion binding analysis and cell detection. This work evidences the potentiality of this approach which allows multiparametric, high-throughput and label-free analysis of biological samples suitable for the detection of compounds as various as proteins, ions or cells and the characterization of their interaction with peptides or proteins

Le transfert vu par les élèves : témoignages d’hier et souvenirs aujourd’hui

Témoignage de deux kessiers de la promotion 1975 (Article publié dans La Jaune et la Rouge – N° 319 – Avril 1977) Christophe Van de Velde et Patrick Puy (X 1975) Pendant les mois qui précédèrent le transfert à Palaiseau, on a beaucoup parlé de notre promotion (la 75), promotion charnière à divers titres ; à savoir le transfert, le nouveau statut et la réforme de l’enseignement. Le transfert, qu’on l’approuve ou non - et nous sommes nombreux à le regretter - faisant partie du passé, les préocc..

Bilan des connaissances sur les conséquences écologiques des invasions de plantes a l'île de la réunion (archipel des mascareignes, océan indien)

Assessment of ecological consequences of plant invasions on Réunion Island (Mascarene Archipelago, Indian Ocean). In western Indian Ocean, Reunion Island remains a hotspot for biological conservation. Such a biological value is mainly threatened by invasion of alien species. Knowledge of ecological consequences of exotic plant invasions has been assessed, in order to suggest guidelines withstanding a regional strategy for invasive plant management. Despite a strong variability of used methods, studies agree on a general impoverishment of species communities and a decrease of natural regeneration. They plead for prioritizing invasive plants. Ecological impact mainly consists in competition between exotic and native plants, and in alteration of primary and secondary successions. Some introduced species act as refuges for some native animal species but the impact of invasive plants on animal communities remains poorly documented. Additionally, the role of human activities in plant invasions (e.g., fluxes of plant species between landscape units) is scarcely studied. A regional strategy developed at the South-eastern Indian Ocean level is recommended, based on both prevention programmes (e.g., control of species introduction, early detecting) and public informationL'île de la Réunion présente un intérêt majeur pour la conservation des ressources biologiques dans l'ouest de l'océan Indien. Ce patrimoine biologique reste menacé au premier rang par les invasions d'espèces introduites. Un bilan des méthodes et des résultats relatifs aux études traitant de la connaissance des conséquences écologiques des invasions de plantes exotiques y a été entrepris, afin de dégager des éléments généraux de stratégie relatifs au contrôle de ces espèces. Malgré une forte variabilité méthodologique, les études convergent vers un appauvrissement des communautés d'espèces et une diminution de la régénération naturelle, et invitent à une réactualisation de la hiérarchisation des priorités d'intervention. Les modes d'impact révélés mettent principalement en évidence une compétition entre les espèces exotiques et indigènes ainsi qu'une altération des successions primaires et secondaires. Certaines espèces introduites assurent un rôle de refuge à l'égard d'espèces animales indigènes mais l'impact général des plantes invasives sur les communautés animales reste sous-étudié. De même, la place des activités humaines, notamment dans le cadre de flux d'espèces entre différents compartiments du paysage, reste peu envisagée. Les méthodes de lutte préventive, basées sur le contrôle des introductions et la détection précoce, en relais avec des actions de sensibilisation, apparaissent comme les éléments centraux d'une stratégie de contrôle des plantes invasives qui pourrait être mise en oeuvre à l'échelle du sud-est de l'océan Indien

Tempo and drivers of plant diversification in the European mountain system

There is still limited consensus on the evolutionary history of species-rich temperate alpine floras due to a lack of comparable and high-quality phylogenetic data covering multiple plant lineages. Here we reconstructed when and how European alpine plant lineages diversified, i.e., the tempo and drivers of speciation events. We performed full-plastome phylogenomics and used multi-clade comparative models applied to six representative angiosperm lineages that have diversified in European mountains (212 sampled species, 251 ingroup species total). Diversification rates remained surprisingly steady for most clades, even during the Pleistocene, with speciation events being mostly driven by geographic divergence and bedrock shifts. Interestingly, we inferred asymmetrical historical migration rates from siliceous to calcareous bedrocks, and from higher to lower elevations, likely due to repeated shrinkage and expansion of high elevation habitats during the Pleistocene. This may have buffered climate-related extinctions, but prevented speciation along elevation gradients as often documented for tropical alpine floras