Impacts du mercure sur la pression artérielle et le système autonome cardiaque chez des populations grandes consommatrices de poisson

Des évidences épidémiologiques et expérimentales suggèrent que l'exposition au mercure pourrait augmenter la pression artérielle (PA) et réduire la variabilité de la fréquence cardiaque (VFC). Cependant, les études précédentes n'ont pas contrôlé l'influence des nutriments tels que les acides gras polyinsaturés oméga-3 (AGPI-oe3) et le sélénium qui pourraient diminuer la toxicité du mercure. L'objectif de cette thèse doctorale était d'évaluer l'impact du mercure sur ces paramètres physiologiques dans trois populations ayant une alimentation riche en poissons. Les résultats d'une enquête de santé conduite chez 732 adultes inuits montraient une association positive entre la concentration de mercure sanguin et la PA systolique et la pression puisée (PP) (Chapitre 2). Dans la même population, nous avons analysé une cohorte de 226 enfants qui ont été suivis de la naissance jusqu'à l'âge de 11 ans. L'augmentation de la concentration de mercure sanguin à 11 ans a été associée à la diminution de la VFC alors que les associations avec la PA n'ont pas atteint le seuil de signification (Chapitre 3). L'impact du mercure sur la PA et la VFC a également été étudié chez 397 adultes cris de la Baie James. Les résultats montraient une diminution de la VFC à travers les tertiles de la concentration sanguine de mercure (Chapitre 4). Finalement, des analyses ont été conduites chez 180 adultes et 101 adolescents de la Polynésie française. La VFC a diminué significativement à travers les tertiles de concentration sanguine de mercure chez les adolescents, alors que les différences étaient proches du seuil de signification chez les adultes (Chapitre 5). En conclusion, les résultats de la présente thèse suggèrent un impact délétère du mercure sur la VFC chez les enfants et les adultes provenant des populations exposées via leur alimentation riche en poissons. Par ailleurs, le mercure semble augmenter la PA et la PP chez les adultes. Ces effets sont indépendantes des nutriments (AGPI-co3 et sélénium) et d'autres contaminants tels que le plomb et les biphényles polychlorés également présents dans l'alimentation traditionnelle de certaines de ces populations

Synthetic seed production from encapsulated somatic embryos of cork oak (Quercus suber L.) and automated growth monitoring.

Cork oak (Quercus suber) somatic embryos were coatedwith alginate for the production of synthetic seeds and their storability for commercialization was investigated. Also, the automatic monitoring of somatic embryo growth with a digital system of image capture was tested.Apower regressionmodelwasfitted between size and fresh weight (Adjusted R-squared = 0.96). This method permitted growth assessment without contamination risk and opens the possibility of an automated control of culture growth for the future up scaling of plant production. Conversion rate of synthetic seedswas higher onmediumsupplementedwithmineral nutrients than onmediumwithout nutrients. Also, when the somatic embryos were coated without mineral nutrients added to the capsule, conversion rate was significantly lower. The addition of sucrose to the capsule had no significant effect on the conversion rate. No differences were recorded between 50 and 100 mM CaCl2 for capsule complexation. Synthetic seeds were cold stored at 4_C for two months without significant loss of conversion capacity. The present study reports the first attempts to determine optimal storage time and conditions for conversion of encapsulated somatic embryos of cork oak

Conceptual model about the entrepreneurial university: design and validation with the PLS methodology

The entrepreneurial university is a growing trend in higher education. Almost three decades of research with studies centred on successful cases from Anglo-Saxon countries serve as a reference for high-income countries. However, these cases cannot be applied to the Latin American reality, as it has distinct circumstances: high rates of informality, of business mortality, low education and scant research. This study analyses, via the technique of structural equation models, the relations between the cultural aspects of the entrepreneurial university, the carrying out of applied research and the creation of fi rms by university centres. With a sample of students of the University of San Martín de Porres (Peru), the existence of positive relations between the distinct variables which make up the idea of the entrepreneurial university is noted (entrepreneurial leadership, entrepreneurial curriculum, entrepreneurial culture, applied research, and fi rm creation and technology transfer). Also, in the area of non- Anglo-Saxon universities a positive effect of the impulse of entrepreneurial behaviours and activities on the starting up of new business initiatives by university graduates is observed

Local-scale dispersal patterns and susceptibility to Dryocosmus kuriphilus in different Castanea species and hybrid clones: insights from a field trial

artículoThe chestnut gall wasp Dryocosmus kuriphilus is a major insect pest affecting chestnut trees worldwide. Medium and long-term control of this pest can be improved by using resistant or less susceptible cultivars and hybrid clones. In addition, little is known about the local patterns of dispersal of the pest. We obtained data from trees of 3 chestnut species and 27 hybrid clones in a field trial in NW Spain with the aim of evaluating the susceptibility of the material to the gall wasp and identifying possible drivers of local spatial dispersal. In the first 3 years of the invasion by D. kuriphilus, the number of trees attacked and the number of galls on each tree were spatially clustered. Tree height significantly predicted both variables, suggesting that gall wasps may use visual cues to locate suitable host trees, at least in the early stage of invasion. Assessment of the susceptibility of hybrid clones/pure species must take concurrent indicators of infestation levels into account. We suggest the use of indices involving galls on shoots because these enable good assessment of the damage to chestnut trees. The study findings add to existing knowledge on the susceptibility of hybrid chestnut clones. We report, for the first time, two hybrid clones resistant to the pest and one hybrid clone which exhibited consistently low values for all of the indicators of infestation level. The results have important implications regarding selection of plant material for use in afforestation in Spain, where the current high rate of chestnut planting is expected to continue.S

Pulsed-field gel electrophoresis analysis of virus assemblages present in a hypersaline environment

A method for analyzing virus assemblages in aquatic environments was developed and used for studying the highest-salinity ponds (from 13.4 to 35% salinity) from a multi-pond solar saltern in Alicante, Spain. The protocol consisted of a series of concentration and purification steps including tangential flow filtration and ultracentrifugation, followed by the preparation of total viral nucleic acids that were subsequently separated by pulsed-field gel electrophoresis. For every sample analyzed, a characteristic DNA pattern was obtained, whose complexity was related to viral diversity. The comparison of our results with a similar analysis carried out with marine virus assemblages shows that, as expected, the viral diversity corresponding to the analyzed hypersaline environment is considerably lower than that of a marine environment

From Metagenomics to Pure Culture: Isolation and Characterization of the Moderately Halophilic Bacterium Spiribacter salinus gen. nov., sp. nov.

Recent metagenomic studies on saltern ponds with intermediate salinities have determined that their microbial communities are dominated by both Euryarchaeota and halophilic bacteria, with a gammaproteobacterium closely related to the genera Alkalilimnicola and Arhodomonas being one of the most predominant microorganisms, making up to 15% of the total prokaryotic population. Here we used several strategies and culture media in order to isolate this organism in pure culture. We report the isolation and taxonomic characterization of this new, never before cultured microorganism, designated M19-40T, isolated from a saltern located in Isla Cristina, Spain, using a medium with a mixture of 15% salts, yeast extract, and pyruvic acid as the carbon source. Morphologically small curved cells (young cultures) with a tendency to form long spiral cells in older cultures were observed in pure cultures. The organism is a Gram-negative, nonmotile bacterium that is strictly aerobic, non-endospore forming, heterotrophic, and moderately halophilic, and it is able to grow at 10 to 25% (wt/vol) NaCl, with optimal growth occurring at 15% (wt/ vol) NaCl. Phylogenetic analysis based on 16S rRNA gene sequence comparison showed that strain M19-40T has a low similarity with other previously described bacteria and shows the closest phylogenetic similarity with species of the genera Alkalilimnicola (94.9 to 94.5%), Alkalispirillum (94.3%), and Arhodomonas (93.9%) within the family Ectothiorhodospiraceae. The phenotypic, genotypic, and chemotaxonomic features of this new bacterium showed that it constitutes a new genus and species, for which the name Spiribacter salinus gen. nov., sp. nov., is proposed, with strain M19-40T ( CECT 8282T IBRC-M 10768T LMG 27464T) being the type strain

Sense of coherence and quality of life in patients treated with antivitamin k oral anticoagulants: a cross-sectional study

The aim of this study was to analyze the correlation between the participants’ self-reported quality of life and their sense of coherence in a sample (n = 85) of patients on treatment with oral antivitamin K anticoagulants. A cross-sectional design was used. The measurement instruments included a questionnaire on sociodemographic variables, the Spanish version of the Abbreviated World Health Organization Quality of Life questionnaire (WHOQOL-BREF), an oral-anticoagulant-treatment-specific quality-of-life questionnaire, and the sense-of-coherence (SOC) scale. We analyzed the correlations between the participants’ characteristics and the results from the quality-of-life and SOC scales. Age, level of education, employment status, living arrangement, and treatment length were the determinants of the quality of life in people treated with oral anticoagulants. We found a significant association between the four domains of the WHOQOL-BREF questionnaire and general treatment satisfaction (p < 0.01); no significant correlations were found between the SOC subscales and the oral-anticoagulant-treatment-specific quality of life in our sample. Women had a worse level of self-management than men. Nursing interventions should be tailored to the needs of the populations on treatment with oral anticoagulants in order to facilitate a higher level of self-management