Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : International audience
Apatite fission track analysis (AFTA) data are used to bring new light on the long-term and recent history of the Baikal rift region (Siberia). We describe the evolution of the topography along a NW-SE profile from the Siberian platform to the Barguzin range across the Baikal-southern Patom range and the northern termination of Lake Baikal. Our results show that the Baikal-Patom range started to form in the Early Carboniferous and was reactivated in Middle Jurassic-Lower Cretaceous times during the orogenic collapse of the Mongol-Okhotsk belt. Samples located in the Siberian platform recorded a continuous sedimentation up to the early Carboniferous but remain unaffected by later tectonic episodes. The Barguzin basin probably started to form as early as Late Cretaceous, suggesting a continuum of deformation between the postorogenic collapse and the opening of the Baikal Rift System (BRS). The initial driving mechanism for the opening of the BRS is thus independent from the India-Asia collision. AFTA show a late Miocene-early Pliocene increase in tectonic extension in the BRS that confirms previous thoughts and might reflect the first significant effect of the stress field generated by the India-Asia collision.
ISSN: 0278-7407

hal-00420895
https://hal.archives-ouvertes.fr/hal-00420895
DOI : 10.1029/2008TC002404

Éditeur(s) : HAL CCSD
Résumé : The functioning of ecosystems is based on the functional diversity, which is the complementto the species diversity. In the tropical rain forest, the saplings grow in the dense and stratifiedunderstorey. This thesis deals with the diversity of realisation of the support function by thesaplings in this context. The hypotheses are that the race through higher and so brighter levelsconstrains the mechanical security of the saplings with necessary biomass saving and need ofreorientation (gravitropism) and acclimation (mecanoperception and response) processes andthat diversity is thus structured by the species light-demand and affinity for the risk. Using awide sample of 16 species, at the Paracou station, relevant functional traits - risk of not-selfsupportingand gravitropic performance - are defined through adapted modellings whichcombine trunk shape, biomass distribution and wood properties. The traits values varybetween species and also with ontogeny and saplings environment. These variations are dueto elementary traits (shape, biomass, wood) with strong geometrical effects. The less selfsupportingspecies (low mechanical security) have the highest gravitropic performances andare also the most light-demanders. A species, Tachigali melinonii, distinguishes itself bystrong slendernesses and a frequent not-self-supporting habit letting suppose a strongadaptability to its mechanical environment. An experiment (growth response to staking),however, did not provide the expected results whereas the species with lower risks, Dicoryniaguianensis, reacted more.
Le fonctionnement des écosystèmes repose sur la diversité fonctionnelle, complément de ladiversité spécifique. En forêt tropicale humide, les jeunes arbres croissent en sous-bois denseet stratifié. Cette thèse porte sur la diversité de réalisation de la fonction biomécanique desoutien. Les hypothèses sont que la "course" vers les strates plus éclairées contraint lasécurité mécanique des jeunes arbres, avec de nécessaires économies de matière et recours àdes processus de réparation (gravitropisme) et d'acclimatation (mécanoperception et réponse),et que la diversité est donc structurée par le besoin en lumière et l'affinité pour le risque desespèces. Avec un échantillon de 16 espèces sur le dispositif de Paracou, des traits fonctionnelspertinents - risque de non-autoportance et performance gravitropique - sont définis au traversde modélisations adaptées qui combinent forme des troncs, répartition des masses etpropriétés du bois. Ces traits varient entre espèces mais aussi avec le développement etl'environnement des arbres. Ces variations sont dues aux variations des traits élémentaires(forme, masses, bois) avec de forts effets géométriques. Les espèces les moins autoportantes(faible sécurité) ont les plus fortes performances gravitropiques. Ce sont aussi les plusdemandeuses de lumière. Une espèce Tachigali melinonii se distingue par de fortsélancements et une fréquente non-autoportance laissant supposer une adaptabilité forte àl'environnement mécanique. Une expérimentation (réponse de croissance au tuteurage) n'acependant pas abouti aux résultats supposés puisque c'est au contraire l'espèce à faible risque,Dicorynia guianensis, qui s'est montrée plus réactive.
https://tel.archives-ouvertes.fr/tel-00272100

tel-00272100
https://tel.archives-ouvertes.fr/tel-00272100
https://tel.archives-ouvertes.fr/tel-00272100/document
https://tel.archives-ouvertes.fr/tel-00272100/file/TheseJaouen.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Up-to-date estimates of the health outcomes of preterm children are needed for assessing perinatal care, informing parents, making decisions about care, and providing evidence for clinical guidelines. To determine survival and neonatal morbidity of infants born from 22 through 34 completed weeks' gestation in France in 2011 and compare these outcomes with a comparable cohort in 1997. The EPIPAGE-2 study is a national, prospective, population-based cohort study conducted in all maternity and neonatal units in France in 2011. A total of 2205 births (stillbirths and live births) and terminations of pregnancy at 22 through 26 weeks' gestation, 3257 at 27 through 31 weeks, and 1234 at 32 through 34 weeks were studied. Cohort data were collected from January 1 through December 31, 1997, and from March 28 through December 31, 2011. Analyses for 1997 were run for the entire year and then separately for April to December; the rates for survival and morbidities did not differ. Data are therefore presented for the whole year in 1997 and the 8-month and 6-month periods in 2011. Survival to discharge and survival without any of the following adverse outcomes: grade III or IV intraventricular hemorrhage, cystic periventricular leukomalacia, severe bronchopulmonary dysplasia, retinopathy of prematurity (stage 3 or higher), or necrotizing enterocolitis (stages 2-3). A total of 0.7% of infants born before 24 weeks' gestation survived to discharge: 31.2% of those born at 24 weeks, 59.1% at 25 weeks, and 75.3% at 26 weeks. Survival rates were 93.6% at 27 through 31 weeks and 98.9% at 32 through 34 weeks. Infants discharged home without severe neonatal morbidity represented 0% at 23 weeks, 11.6% at 24 weeks, 30.0% at 25 weeks, 47.5% at 26 weeks, 81.3% at 27 through 31 weeks, and 96.8% at 32 through 34 weeks. Compared with 1997, the proportion of infants surviving without severe morbidity in 2011 increased by 14.4% (P < .001) at 25 through 29 weeks and 6% (P < .001) at 30 through 31 weeks but did not change appreciably for those born at less than 25 weeks. The rates of antenatal corticosteroid use, induced preterm deliveries, cesarean deliveries, and surfactant use increased significantly in all gestational-age groups, except at 22 through 23 weeks. The substantial improvement in survival in France for newborns born at 25 through 31 weeks' gestation was accompanied by an important reduction in severe morbidity, but survival remained rare before 25 weeks. Although improvement in survival at extremely low gestational age may be possible, its effect on long-term outcomes requires further studies. The long-term results of the EPIPAGE-2 study will be informative in this regard.
ISSN: 2168-6211

hal-01258705
http://hal.univ-brest.fr/hal-01258705
PUBMED : 25621457
DOI : 10.1001/jamapediatrics.2014.3351

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Cnidarian–dinoflagellate photosynthetic symbioses are fundamental to biologically diverse and productive coral reef ecosystems. The hallmark of this symbiotic relationship is the ability of dinoflagellate symbionts to supply their cnidarian host with a wide range of nutrients. Many aspects of this association nevertheless remain poorly characterized, including the exact identity of the transferred metabolic compounds, the mechanisms that control their exchange across the host–symbiont interface, and the precise subcellular fate of the translocated materials in cnidarian tissues. This lack of knowledge is mainly attributed to difficulties in investigating such metabolic interactions both in situ, i.e. on intact symbiotic associations, and at high spatial resolution. To address these issues, we illustrate the application of two in situ and high spatial resolution molecular and ion imaging techniques–matrix-assisted laser desorption ionization mass spectrometry imaging (MALDI-MSI) and the nano-scale secondary-ion mass spectrometry (NanoSIMS) ion microprobe. These imaging techniques provide important new opportunities for the detailed investigation of many aspects of cnidarian–dinoflagellate associations, including the dynamics of cellular interactions.
ISSN: 0944-2006

hal-01546914
http://hal.upmc.fr/hal-01546914
DOI : 10.1016/j.zool.2014.06.006

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
ISSN: 1156-5233

hal-01659742
https://hal.archives-ouvertes.fr/hal-01659742
DOI : 10.1016/j.mycmed.2017.10.004

Éditeur(s) : HAL CCSD
Résumé : International audience
Background Orodental diseases include several clinically and genetically heterogeneous disorders that can present in isolation or as part of a genetic syndrome. Due to the vast number of genes implicated in these disorders, establishing a molecular diagnosis can be challenging. We aimed to develop a targeted next-generation sequencing (NGS) assay to diagnose mutations and potentially identify novel genes mutated in this group of disorders. Methods We designed an NGS gene panel that targets 585 known and candidate genes in orodental disease. We screened a cohort of 101 unrelated patients without a molecular diagnosis referred to the Reference Centre for Oro-Dental Manifestations of Rare Diseases, Strasbourg, France, for a variety of orodental disorders including isolated and syndromic amelogenesis imperfecta (AI), isolated and syndromic selective tooth agenesis (STHAG), isolated and syndromic dentinogenesis imperfecta, isolated dentin dysplasia, otodental dysplasia and primary failure of tooth eruption. Results We discovered 21 novel pathogenic variants and identified the causative mutation in 39 unrelated patients in known genes (overall diagnostic rate: 39%). Among the largest subcohorts of patients with isolated AI (50 unrelated patients) and isolated STHAG (21 unrelated patients), we had a definitive diagnosis in 14 (27%) and 15 cases (71%), respectively. Surprisingly, COL17A1 mutations accounted for the majority of autosomal-dominant AI cases. Conclusions We have developed a novel targeted NGS assay for the efficient molecular diagnosis of a wide variety of orodental diseases. Furthermore, our panel will contribute to better understanding the contribution of these genes to orodental disease. Trial registration numbers NCT01746121 and NCT02397824
Journal of Medical Genetics

hal-01272929
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01272929
DOI : 10.1136/jmedgenet-2015-103302
PUBMED : 26502894