Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Strain and strain rate partitioning in partially molten rocks are two of the important mechanisms that govern the process of coupling and/or decoupling of the partially molten lithosphere. Consequently, the proportion of partial melt and crystals and their network in partially molten rocks influence the degree of the partitioning along with the bulk rheology of the system. This study explores the possible role of finite strain and strain rate on the rate and volume of partial melting and crystallization in a metapelitic system undergoing deformation. Cylinders of synthetic quartz-muscovite aggregate (7: 3 volume ratio) were deformed in torsion at 750 C, 300 MPa and constant shear strain rate ((gamma) over dot = 3 x 10(-4) s(-1)) for finite shear strains (gamma) 1-15. The deformed samples were studied along the longitudinal tangential ( LT) and axial ( LA) sections to obtain the data along a range of strain rates for a given finite strain and vice versa. The results showed that deformation plays an important role on the kinetics of partial melting and crystallization. With increasing strain rate, amount and rate of crystallization comprise the volumetrically dominant process compared to partial melting at a given finite strain. In contrast, when the strain rate is constant, partial melting is the dominant process over crystallization up to moderate strain (gamma < 5). The dominant process reverses at higher strain, and the system shows more crystallization than partial melting. Application of the experimental data to geological systems implies that for metapelites a significant amount (similar to 20%) of partial melt can generate at high strain rate and moderate strain (gamma similar to 7), but at high strain (gamma = 15) the system is melt depleted. Under such conditions, decoupling should take place in brittle-ductile mode. On the other hand, rocks undergoing deformation with low strain rates and strain (gamma < 3) contain more than 25% partial melt, which can act as a major decoupling agent by localizing ductile shear zones.
ISSN: 0148-0227

hal-00617714
https://hal.archives-ouvertes.fr/hal-00617714
DOI : 10.1029/2010JB007865

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Few studies have considered using environmental amenities to explain social health inequalities.Nevertheless, Green spaces that promote good health may have an effect on socioeconomic health inequalities. In developed countries, there is considerable evidence that green spaces have a beneficial effect on the health of urban populations and recent studies suggest they can have a positive effect on pregnancy outcomes. To investigate the relationship between green spaces and the spatial distribution of infant mortality taking account neighborhood deprivation levels. METHODS: The study took place in Lyon metropolitan area, France. All infant deaths that occurred between 2000 and 2009 were geocoded at census block level. Each census block was assigned greenness and socioeconomic deprivation levels. The spatial--scan statistic was used to identify high risk cluster of infant mortality according to these neighborhood characteristics. RESULTS: The spatial distribution of infant mortality was not random with a high risk cluster in the south east of the Lyon metropolitan area (p<0.003). This cluster disappeared (p=0.12) after adjustment for greenness level and socioeconomic deprivation, suggesting that these factors explain part of the spatial distribution of infant mortality. These results are discussed using a conceptual framework with 3 hypothetical pathways by which green spaces may have a beneficial effect on adverse pregnancy outcomes: (i) a psychological pathway, (ii) a physiological disruption process and (iii) an environmental pathway. CONCLUSIONS: These results add some evidence to the hypothesis that there is a relationship between access to green spaces and pregnancy outcomes but further research is required to confirm this.
BMC Pregnancy and Childbirth

hal-00876083
https://hal.archives-ouvertes.fr/hal-00876083
https://hal.archives-ouvertes.fr/hal-00876083/document
DOI : 10.1186/1471-2393-13-191

Éditeur(s) : HAL CCSD Ecole nationale du génie rural
Résumé :  
Le Groupement d'Intérêt scientifique (GIS) Silvolab-Guyane coordonne, depuis 1992, les actions de recherche ou de développement sur la forêt tropicale en Guyane, à partir d'orientations scientifiques cadrées et sur financements publics. Les programmes sont exécutés par les chercheurs des organismes membres du GIS, éventuellement en partenariat avec des laboratoires métropolitains ou des instituts étrangers. L'objectif est d'enrichir les connaissances sur la description, la dynamique et l'évolution des écosystèmes pour mieux protéger, gérer ou valoriser la forêt en tant que ressource naturelle. Outre la réalisation conjointe de projets ciblés sur une problématique particulière, la mise en commun d'équipements transversaux tels les laboratoires, l'herbier de Cayenne, le centre de documentation de Kourou, mais aussi et surtout les stations de terrain et les dispositifs expérimentaux, sont des atouts majeurs du GIS.
ISSN: 0035-2829

hal-01032106
https://hal.archives-ouvertes.fr/hal-01032106

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
BACKGROUND: Few studies have considered using environmental amenities to explain social health inequalities.Nevertheless, Green spaces that promote good health may have an effect on socioeconomic health inequalities. In developed countries, there is considerable evidence that green spaces have a beneficial effect on the health of urban populations and recent studies suggest they can have a positive effect on pregnancy outcomes. To investigate the relationship between green spaces and the spatial distribution of infant mortality taking account neighborhood deprivation levels. METHODS: The study took place in Lyon metropolitan area, France. All infant deaths that occurred between 2000 and 2009 were geocoded at census block level. Each census block was assigned greenness and socioeconomic deprivation levels. The spatial--scan statistic was used to identify high risk cluster of infant mortality according to these neighborhood characteristics. RESULTS: The spatial distribution of infant mortality was not random with a high risk cluster in the south east of the Lyon metropolitan area (p<0.003). This cluster disappeared (p=0.12) after adjustment for greenness level and socioeconomic deprivation, suggesting that these factors explain part of the spatial distribution of infant mortality. These results are discussed using a conceptual framework with 3 hypothetical pathways by which green spaces may have a beneficial effect on adverse pregnancy outcomes: (i) a psychological pathway, (ii) a physiological disruption process and (iii) an environmental pathway. CONCLUSIONS: These results add some evidence to the hypothesis that there is a relationship between access to green spaces and pregnancy outcomes but further research is required to confirm this.
ISSN: 1471-2393

inserm-00878362
http://www.hal.inserm.fr/inserm-00878362
http://www.hal.inserm.fr/inserm-00878362/document
http://www.hal.inserm.fr/inserm-00878362/file/1471-2393-13-191.pdf
DOI : 10.1186/1471-2393-13-191

Éditeur(s) : HAL CCSD Cold Spring Harbor Laboratory Press
Résumé : “Human and Environmental Genomics” platform (Rennes) for Illumina sequencing / Proteomics Core Facility of the Cambridge Institute (Cancer Research UK)
International audience
Epigenetic mechanisms are believed to play key roles in the establishment of cell-specific transcription programs. Accordingly, the modified bases 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) have been observed in DNA of genomic regulatory regions such as enhancers, and oxidation of 5mC into 5hmC by Ten-eleven translocation (TET) proteins correlates with enhancer activation. However, the functional relationship between cytosine modifications and the chromatin architecture of enhancers remains elusive. To gain insights into their function, 5mC and 5hmC levels were perturbed by inhibiting DNA methyltransferases and TETs during differentiation of mouse embryonal carcinoma cells into neural progenitors, and chromatin characteristics of enhancers bound by the pioneer transcription factors FOXA1, MEIS1, and PBX1 were interrogated. In a large fraction of the tested enhancers, inhibition of DNA methylation was associated with a significant increase in monomethylation of H3K4, a characteristic mark of enhancer priming. In addition, at some specific enhancers, 5mC oxidation by TETs facilitated chromatin opening, a process that may stabilize MEIS1 binding to these genomic regions.
ISSN: 1088-9051

Droits : http://creativecommons.org/licenses/by-nc/
hal-01533248
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533248
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533248/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01533248/file/Genome%20Res.-2017-Mah%C3%A9-947-58.pdf
DOI : 10.1101/gr.211466.116