Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
This study presents microstructural evidence for deformation-controlled melt organization and for changes in olivine deformation associated with the presence of melt in an 80 m vertical section of the crust-mantle transition zone in the Oman ophiolite. This zone represents an 'end member' case for analyzing feedbacks between deformation and melt distribution in the upper mantle, since it experienced strong shear strains in presence of large melt fractions. It is characterized by a subhorizontal compositional layering at the mm to meter scale, from weakly impregnated dunites to olivine-rich gabbros, which parallels a pervasive foliation containing a strong stretching lineation. The parallelism between the compositional layering and the foliation, the diffuse limits of the layers, the alignment of elongated plagioclase-rich aggregates devoid of internal deformation structures with the elongation of olivine crystals in the dunitic layers, and the sharp compositional changes across some, but not all layer limits suggest deformation plays an essential role on the development of the layering. The variation on a mm-scale of the olivine crystal preferred orientation (CPO) symmetry as a function of the modal content: from axial-[100] symmetry in layers with <70% modal olivine to axial-[010] in more gabbroic levels (<40% olivine), which is repeated over the entire section, implies deformation in presence of variable melt fractions. Axial-[100] olivine CPO in olivine-rich layers is consistent with deformation by dislocation creep under high temperature, low pressure, dry conditions. Axial-[010] olivine CPO patterns imply additional sliding along preferentially wetted (010) grain boundaries, increase in the activity of [001] glide, or transpression localized in the melt-rich layers. Since the change in CPO symmetry is not accompanied by dispersion, instantaneous melt fractions must have remained <30-40% in all layers. The continuous variation in olivine CPO symmetry with decreasing olivine content implies therefore that the former depends on the cumulated strain in presence of melt rather than on the instantaneous melt fraction.
ISSN: 0012-821X

hal-00795508
https://hal.archives-ouvertes.fr/hal-00795508
DOI : 10.1016/j.epsl.2012.10.003

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Several studies, both theoretical and experimental, show that sedimentary rocks have a fractal pore-grain interface. In this paper a computer simulated 3-D sedimentary rock structure generated by the Relaxed Ballistic Bidisperse Deposition Model (RBBDM), is investigated to characterize the micro structure of its pores. The pore volume and the rock-pore interface show the same fractal dimension indicating that the pore volume is a fractal. The two point density correlation is computed for the pore space and the results compare favourably with the range reported from experiments. An array of 2-D X-ray tomography micrograph sections of a real sedimentary rock, an oolitic limestone (pure calcite) from the Mondeville formation of Middle Jurassic age (Paris Basin, France), was used to generate a 3-D bitmap. The 3-D real rock sample generated in this manner, was analysed for similar studies as the simulated structure. The results were compared with those obtained from simulation. The simulation results agree qualitatively with the real rock sample. Diffusion through the connected pore space of the simulated structure was studied using a random walk algorithm and the results compared with the similar simulation study done on the 3-D oolitic limestone specimen. In both cases diffusion was found to be anomalous indicating that the sedimentary rock has a fractal geometry. The favourable comparability of results between the simulated and real rock supports the usefulness of the model of sedimentary rock generation which can be applicable to transport phenomena.
ISSN: 0956-540X

hal-00823061
https://hal.archives-ouvertes.fr/hal-00823061
DOI : 10.1093/gji/ggs084

Éditeur(s) : HAL CCSD ACSM
Résumé : International audience
PURPOSE AND METHODS: This study was designed to determine whether the physiological responses elicited during the run part of repeated bouts of cycle-run exercise are similar to those required during the run segment of a cycle-run succession. Thirteen male triathletes underwent four successive laboratory trials: 1) an incremental treadmill test, 2) an incremental cycle test, 3) 30 min of cycling followed by 20 min of running (C-R), and 4) five repeated bouts of 6 min of cycling and 4 min of running (X-CR). During the C-R and X-CR trials, venous blood samples were obtained to measure lactate, epinephrine and norepinephrine concentrations. During all trials, ventilatory data were collected every min using an automated breath-by-breath system. RESULTS: The results showed that 1) the cardiorespiratory responses observed during running were similar in the X-CR and C-R trials, 2) the lactate concentration was similar in both trials, 3) the epinephrine concentration was greater (277.9 +/- 11.9 vs 169.8 +/- 86.7 pg x mL(-1), P < 0.025) in X-CR than in C-R, and 4) the norepinephrine concentration was similar in both trials, except at the first cycle-run succession (T1) of X-CR. CONCLUSION: We concluded that 1) multi-block training is a good method to stimulate the specific adaptations required for the cycle-run succession, and particularly for the cycle-run transition, and 2) multi-block training seems to induce a greater catecholaminergic response, which may be due to a combination of an inherent effect of this type of training and the triathletes' relative lack of experience with it. In any case, the efficacy of the multi-block model needs to be more thoroughly evaluated over the course of a longer-term training program.
Medicine & Science in Sports & exercise

hal-00720475
https://hal.univ-antilles.fr/hal-00720475
https://hal.univ-antilles.fr/hal-00720475/document
https://hal.univ-antilles.fr/hal-00720475/file/Article_2_.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
Over the past decade, much attention has been devoted to the development of forest biomass estimation methods at a stand scale, leading to the establishment of allometric models (Chave et al., 2014). These allometric equations use a unique wood specific gravity value (WSG) per species, but neglect the within tree variations of WSG found by others (Wiemann & Williamson, 1989).The main objectives of this study are (1) to illustrate the diversity of radial (from pith to bark) and longitudinal (from bottom to top) patterns of WSG variation within and between species, (2) to highlight different trends of WSG radial variations and the possible misinterpretations of these trends due to the effect of heartwood and (3) to link these variations and patterns to the successional status of the species (from pioneer to sciaphilic species).We sampled 33 small trees (10 Wood sciences underpinning tropical ecology and management. International closing symposium of the XYLAREDD project.
Tervuren, Belgium

hal-01188894
https://hal-sde.archives-ouvertes.fr/hal-01188894

Éditeur(s) : HAL CCSD
Résumé : International audience
Radiocarbon dating and "old wood problem" in the Antilles : the state of the artAmong the many effects that may distort the interpretation of radiocarbon dates are those for which the age of the archaeological event is different from the radiocarbon age of the sample or "14C event" age. This type of problem arises in many cases, notably in the "old wood effect”, and occurs in various regions of the world where very long-lived trees species are common. In the Caribbean anthracological studies indicate a very high frequency of some indigenous centuries-old species such as Guaiacum, Guaiacum officinale L. However the absence of tree-ring data in humid tropical zones deprives us of an accurate inventory of long-lived species and especially the assessment of their longevity. Here we present measurements which enable us to estimate the longevity of archaeological Guaiacum wood posts. They highlight a gap of several centuries between wood from the outer edge and the heart of the tree. This example illustrates the additional uncertainty that can result from dating archeological events when dates are realized on unidentified botanical species from which the area that was sampled is unknown. Another source of error could arise from the use of rot-proof dead wood as fuel if we take into consideration that major hurricanes can produce large amounts of dead wood that may be collected for decades, even centuries. To improve chronometric data used in archaeological interpretations, it is necessary to ensure the quality of the dating process by following a protocol similar to those used in other regions of the world based on a better understanding of the material to be dated by preliminary identifications of wood samples: species, anatomical part, wood moisture content (unseasoned or seasoned).
Radiocarbono y "problema madera vieja", que data de las Antillas: estado del arteEntre los muchos efectos que pueden distorsionar la interpretación de fechas de radiocarbono, destacan aquellos para los que la edad de la prueba arqueológica es diferente de la edad de radiocarbono de la muestra, o la edad del "evento de radiocarbono." Este tipo de problema se presenta en muchos casos, especialmente uno llamado "efecto madera vieja." Esto se refleja en diversas regiones del mundo donde las especies de plantas de mucha longevidad son comunes. En el Caribe, los estudios antracológicos disponibles indican una muy alta frecuencia de algunas especies autóctonas como el guayaco, Guaiacum officinale L. Sin embargo, la casi ausencia de datos de anillos de árboles en los trópicos húmedos, nos impide realizar un inventario exacto de especies de mucha longevidad y sobre todo la evaluación de la longevidad. Algunas de las pruebas presentadas aquí permitieron una estimación de la longevidad de de unos postes de guayaco de origen arqueológico. Ponen de manifiesto una brecha de varios siglos entre las partes externas y el corazón del tronco. Este ejemplo ilustra la aparición de una incertidumbre adicional en la datación de los eventos arqueológicos cuando no conocemos la especie botánica y tampoco la zona de la muestra en el árbol. Otra fuente de error puede surgir de la utilización de la madera muerta de calidad duradera como combustible ya que los grandes huracanes pueden producir grandes cantidades de madera muerta, que puede ser requerida durante décadas, incluso siglos. Para mejorar los datos cronométricos utilizados en interpretaciones arqueológicas, es necesario asegurarse de la calidad de las fechas, y por lo tanto seguir un protocolo similar a los utilizados en otras regiones fundado en una mejor comprensión de los elementos: especie, parte anatómica, humedad de la madera usada (verde o seco).
Parmi les nombreux effets susceptibles de fausser l’interprétation des datations par le radiocarbone, figurent ceux pour lesquels l’âge de l’événement archéologique est différent de l’âge radiocarbone de l’échantillon, ou âge de l’« événement radiocarbone ». Ce type de problème se pose dans de nombreux cas, en particulier celui dénommé « effet vieux bois ». Cette question est prise en compte dans diverses régions du monde où des espèces végétales très longévives sont fréquentes. Dans les Antilles les études anthracologiques disponibles indiquent une fréquence très importante de certaines espèces autochtones multiséculaires dont le gaïac, Guaiacum officinale L.. Cependant, la quasi absence de données dendrochronologiques dans la zone tropicale humide, nous privent d’un inventaire précis des espèces longévives et surtout de l’évaluation de leur longévité. Quelques tests présentés ici ont permis une estimation de la longévité de poteaux d’origine archéologique en bois de gaïac. Ils mettent en évidence un décalage de plusieurs siècles entre les parties externes et le cœur du tronc. Cet exemple illustre l’apparition d’une incertitude supplémentaire dans la datation de l’événement archéologique lorsque que l’on ne connaît ni l’espèce botanique ni la zone de prélèvement dans l’arbre. Une autre source d’erreur pourrait provenir de l’utilisation de bois mort de qualité très durable comme combustible, sachant que les grands cyclones peuvent produire d’importantes quantités de bois mort susceptible d’être récolté pendant des décennies, voire des siècles. Afin d’améliorer les données chronologiques utilisées dans les interprétations archéologiques, il apparaît nécessaire de s’assurer de la qualité des datations, et donc de suivre un protocole similaire à ceux utilisés dans d’autres régions basé sur une meilleure connaissance des éléments datés : espèce, partie anatomique, humidité du bois utilisé (vert ou sec).
Puerto Rico 2013 : Actas del 25to Congreso Internacional de Arqueología del Caribe - Proceeding of the 25th International Congress for Caribbean Archeology - Comptes rendus des communications du 25e Congrés International de l'Archéologie de la Caraïbe
San-Juan, Puerto Rico

hal-01198567
https://hal.archives-ouvertes.fr/hal-01198567
https://hal.archives-ouvertes.fr/hal-01198567/document
https://hal.archives-ouvertes.fr/hal-01198567/file/Stouvenot%20et%20al.%202015.%20Effet%20vieux%20bois%20radiocarbone%20Antilles%20HD.pdf

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
IntroductionLeishmania RNA virus type 1 (LRV1) is an endosymbiont of some Leishmania (Vianna) species in South America. Presence of LRV1 in parasites exacerbates disease severity in animal models and humans, related to a disproportioned innate immune response, and is correlated with drug treatment failures in humans. Although the virus was identified decades ago, its genomic diversity has been overlooked until now.Methodology/Principles findingsWe subjected LRV1 strains from 19 L. (V.) guyanensis and one L. (V.) braziliensis isolates obtained from cutaneous leishmaniasis samples identified throughout French Guiana with next-generation sequencing and de novo sequence assembly. We generated and analyzed 24 unique LRV1 sequences over their full-length coding regions. Multiple alignment of these new sequences revealed variability (0.5%±23.5%) across the entire sequence except for highly conserved motifs within the 5' untranslated region. Phylogenetic analyses showed that viral genomes of L. (V.) guyanensis grouped into five distinct clusters. They further showed a species-dependent clustering between viral genomes of L. (V.) guyanensis and L. (V.) braziliensis, confirming a long-term co-evolutionary history. Noteworthy, we identified cases of multiple LRV1 infections in three of the 20 Leishmania isolates.Conclusions/SignificanceHere, we present the first-ever estimate of LRV1 genomic diversity that exists in Leishmania (V.) guyanensis parasites. Genetic characterization and phylogenetic analyses of these viruses has shed light on their evolutionary relationships. To our knowledge, this study is also the first to report cases of multiple LRV1 infections in some parasites. Finally, this work has made it possible to develop molecular tools for adequate identification and genotyping of LRV1 strains for diagnostic purposes. Given the suspected worsening role of LRV1 infection in the pathogenesis of human leishmaniasis, these data have a major impact from a clinical viewpoint and for the management of Leishmania-infected patients.
ISSN: 1935-2727

pasteur-01583523
https://hal-riip.archives-ouvertes.fr/pasteur-01583523
DOI : 10.1371/journal.pntd.0005764
PUBMED : 28715422

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Exposure to solvents during pregnancy has long been suspected to increase the risk of congenital malformations. Glutathione S-transferases (GSTs) are enzymes essential for the detoxification of various chemicals. Our objective here was to assess whether GST polymorphisms might modify the association between maternal solvent exposure and the risk of birth defects. A prospective cohort included 3421 pregnant women in Brittany, France (2002-2006). Occupational exposure to solvents was assessed from a job-exposure matrix. Congenital malformations were diagnosed among livebirths, stillbirths, and medical pregnancy terminations. Using a nested case-control design, 32 babies with major birth defects were compared to 348 normal births for babies' cord blood genotypes (at GSTT1 and GSTM1) and maternal occupational solvent exposure. Logistic models were used to adjust for potential confounders. The risk of major defects increased significantly in women with solvent exposure (20% of controls and 34% of cases). Frequencies of the null genotype of both the GSTT1 and GSTM1 genes were similar among controls and cases. There was a significantly increased risk of birth defects in GSTM1 not-null cord-blood genotype in pregnancies exposed to solvents (odds ratio [OR], 1.0 for not-null, not-exposed; OR, 4.0 for not-null, exposed; 95% confidence interval [CI], 1.4-11.2; OR, 1.6 for null, not-exposed; 95% CI, 0.6-3.9; OR, 1.0 for null, exposed; 95% CI, 0.2-4.7; p = 0.05). This nested case-control study suggests that the child's GSTM1 genotype modifies the risk of major birth defects among offspring of solvent-exposed women. Replication and additional investigations are necessary to confirm and elucidate these findings.
ISSN: 1542-0752

hal-00875957
https://hal.archives-ouvertes.fr/hal-00875957
DOI : 10.1002/bdra.23018
PUBMED : 22570144

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
BACKGROUND: This study examines gene-environment interaction between the MTHFR C667T polymorphism and folic acid in the etiology of orofacial clefts (OFC). We used a pooled-analytical approach on four studies that used similar methods. METHODS: We used logistic regression to analyze the pooled sample of 1149 isolated cases and 1161 controls. Fetal and maternal MTHFR C677T genotypes, and maternal periconceptional exposure to smoking, alcohol, vitamin containing folic acid and folic acid supplements were contrasted between the cleft types [non-syndromic clefts lip or without cleft palate (CL(P)) and non-syndromic cleft palate (CP)] and control groups. RESULTS: There was a reduced risk of CL(P) with maternal folic acid use (p = 0.008; OR = 0.70, 95% CI: 0.65-0.94) and with supplements containing folic acid (p = 0.028, OR = 0.80, 95% CI: 0.65-0.94). Maternal smoking increased the risk of both CL(P) (p < 10 e-3; OR = 1.62, 95% CI: 1.35-1.95) and CP (p = 0.028; OR = 1.38, 95% CI: 1.04-1.83). No significant risk was observed with either maternal or fetal MTHFR C677T genotypes. CONCLUSION: This individual participant data (IPD) meta-analysis affords greater statistical power and can help alleviate the problems associated with aggregate-level data-sharing. The result of this IPD meta-analysis is consistent with previous reports suggesting that folic acid and smoking influence OFC outcomes.
ISSN: 1542-0752

hal-00875899
https://hal.archives-ouvertes.fr/hal-00875899
DOI : 10.1002/bdra.23133
PUBMED : 23670871

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
The etiology of congenital heart defect (CHD) combines environmental and genetic factors. So far, there were studies reporting on the screening of a single gene on unselected CHD or on familial cases selected for specific CHD types. Our goal was to systematically screen a proband of familial cases of CHD on a set of genetic tests to evaluate the prevalence of disease-causing variant identification. A systematic screening of GATA4, NKX2-5, ZIC3 and Multiplex ligation-dependent probe amplification (MLPA) P311 Kit was setup on the proband of 154 families with at least two cases of non-syndromic CHD. Additionally, ELN screening was performed on families with supravalvular arterial stenosis. Twenty-two variants were found, but segregation analysis confirmed unambiguously the causality of 16 variants: GATA4 (1 x), NKX2-5 (6 x), ZIC3 (3 x), MLPA (2 x) and ELN (4 x). Therefore, this approach was able to identify the causal variant in 10.4% of familial CHD cases. This study demonstrated the existence of a de novo variant even in familial CHD cases and the impact of CHD variants on adult cardiac condition even in the absence of CHD. This study showed that the systematic screening of genetic factors is useful in familial CHD cases with up to 10.4% elucidated cases. When successful, it drastically improved genetic counseling by discovering unaffected variant carriers who are at risk of transmitting their variant and are also exposed to develop cardiac complications during adulthood thus prompting long-term cardiac follow-up. This study provides an important baseline at dawning of the next-generation sequencing era.
ISSN: 1018-4813

hal-01404211
https://hal-univ-bourgogne.archives-ouvertes.fr/hal-01404211
DOI : 10.1038/ejhg.2015.105
PUBMED : 26014430

Éditeur(s) : HAL CCSD
Résumé : National audience
Objective of the study An estimation of burden of serious fungal diseases in France is essential data to inform public health priorities on the importance of resources and research needed on these infections. In France, precise data are available for invasive fungal diseases but estimates for several other diseases such as chronic and immunoallergic diseases are by contrast less known. Materials and methods A systematic literature search was conducted using the Web of Science Platform. Published epidemiology papers reporting fungal infection rates from France were identified. Where no data existed, we used specific populations at risk and fungal infection frequencies in those populations to estimate national incidence or prevalence, depending on the condition. Results The model predicts high prevalences of severe asthma with fungal sensitization episodes (189 cases/100,000 adults per year), of allergic bronchopulmonary aspergillosis (145/100,000) and of chronic pulmonary aspergillosis (5.24/100,000). Besides, estimated incidence for invasive aspergillosis is 1.8/100,000 annually based on classical high risk factors. Estimates for invasive mucormycosis, pneumocystosis and cryptococcosis are 0.12/100,000, 1/100,000 and 0.2/100,000, respectively. Regarding invasive candidiasis, more than 10,000 cases per year are estimated, and a much higher number of recurrent vaginal candidiasis is probable but must be confirmed. Finally, this survey was an opportunity to report a first picture of the frequency of tinea capitis in France. Conclusion Using local and literature data of the incidence or prevalence of fungal infections, approximately 1,000,000 (1.47%) people in France are estimated to suffer from serious fungal infections each year. © 2016 Elsevier Masson SAS
Journal de Mycologie Medicale

hal-01467554
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467554
DOI : 10.1016/j.mycmed.2016.11.001
PUBMED : 27887809

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Predicting the impact of underground engineering on the environment requires the knowledge of natural media at different scales. In particular, understanding basic phenomena controlling the properties of rocks in the presence of complex fluids necessitates a detailed atomic description of the solid/fluid/solid contacts, the subject of Part I of the present study. First, building the solid interspace between two different crystals in a non-periodic situation is achieved using the ab initio and molecular mechanics code GenMol (TM). A description of the fluid confined within the interspace is then derived from the original genetic iterative multi-species (GIMS) algorithm implemented in the same code. This approach consists of equilibrating chemical potentials, cycle after cycle and species after species, between the confined fluid and the free natural fluid. An elementary iteration for a species k consists of different steps incrementing the number N-k of particles k, with other numbers N-k remaining constant. At each step, an optimum fluid composition is obtained by a genetic process distributing the fluid particles on a grid by stochastic shots, followed in fine by a refining process. The effectiveness of the GIMS approach is demonstrated in the case study of a fluid confined between two (0 0 1) kaolinite faces, with apertures h varying between 4 and 10 A. connected to a 9-species external solution [H2O, Cl-, Na+ CO2(aq), NaCl(aq), Ca2+, Mg2+, HCO3-, H3O+] where concentrations are ranging from 55 to 10(-4) mol/L. The results show a drastic variation in the solute/solvent and cations/ions ratios in the confined fluid when aperture h is lowered to less than 1 nm. These results obtained with a very rapid convergence of the iterative algorithm combined with a very competitive genetic optimizer are validated with high precision on a free solution. This description of contacts between crystals is original and unattainable by standard crystal interface approaches. It opens the way to understanding and/or predicting phenomena between crystals in a complex natural environment, such as adhesion or repulsion investigated in the Part II of this study.
ISSN: 0022-0248

hal-00544569
https://hal.archives-ouvertes.fr/hal-00544569
DOI : 10.1016/j.jcrysgro.2010.08.009

Éditeur(s) : HAL CCSD American Society of Tropical Medicine and Hygiene
Résumé : International audience
Histoplasmosis is the first cause of acquired immunodeficiency syndrome (AIDS) and AIDS-related deaths in French Guiana. Cohort data were used to determine whether primary prophylaxis with 100 mg itraconazole for patients with CD4 counts < 150/mm(3) was cost-effective with different scenarios. For a scenario where 12% of patients died, 60% were aware of their human immunodeficiency virus (HIV) infection and adherence was only 50%, primary prophylaxis would prevent 1 death and 9 cases of histoplasmosis for a cost of 36,792 Euros per averted death, 1,533 per life-year saved, 4,415 Euros per averted case, when only counting the costs of itraconazole prophylaxis. Taking into account the total costs of hospitalization showed that primary prophylaxis would allow a savings of 185,178 Euros per year. Even in a scenario of low adherence, primary prophylaxis would be cost-effective in French Guiana, and presumably in the rest of the Guianas and the Amazon.
ISSN: 0002-9637

inserm-00913886
http://www.hal.inserm.fr/inserm-00913886
http://www.hal.inserm.fr/inserm-00913886/document
http://www.hal.inserm.fr/inserm-00913886/file/2013_Nacher_-_Primary_prophylaxissur disseminated_histoplasmosis_in_HIV_patients_in_French_Guiana_a_cost_effectiveness_study.pdf
DOI : 10.4269/ajtmh.13-0082

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Plant-ants live in a mutualistic association with host plants known as "myrmecophytes" that provide them with a nesting place and sometimes with extra-floral nectar (EFN) and/or food bodies (FBs); the ants can also attend sap-sucking Hemiptera for their honeydew. In return, plant-ants, like most other arboreal ants, protect their host plants from defoliators. To satisfy their nitrogen requirements, however, some have optimized their ability to capture prey in the restricted environment represented by the crowns of trees by using elaborate hunting techniques. In this study, we investigated the predatory behavior of the ant Azteca andreae which is associated with the myrmecophyte Cecropia obtusa. We noted that up to 8350 ant workers per tree hide side-by-side beneath the leaf margins of their host plant with their mandibles open, waiting for insects to alight. The latter are immediately seized by their extremities, and then spread-eagled; nestmates are recruited to help stretch, carve up and transport prey. This group ambush hunting technique is particularly effective when the underside of the leaves is downy, as is the case for C. obtusa. In this case, the hook-shaped claws of the A. andreae workers and the velvet-like structure of the underside of the leaves combine to act like natural Velcro that is reinforced by the group ambush strategy of the workers, allowing them to capture prey of up to 13,350 times the mean weight of a single worker.
ISSN: 1932-6203

hal-00818187
https://hal.archives-ouvertes.fr/hal-00818187
https://hal.archives-ouvertes.fr/hal-00818187/document
https://hal.archives-ouvertes.fr/hal-00818187/file/Dejean2010_Arboreal.pdf
DOI : 10.1371/journal.pone.0011331

Éditeur(s) : HAL CCSD
Résumé : International audience
Background: We examined the association between exposure during pregnancy to trihalomethanes, the most common water disinfection by-products, and birth outcomes in a European cohort study (Health Impacts of Long-Term Exposure to Disinfection By-Products in Drinking Water). We took into account exposure through different water uses, measures of water toxicity, and genetic susceptibility. Methods: We enrolled 14,005 mothers (2002-2010) and their children from France, Greece, Lithuania, Spain, and the UK. Information on lifestyle- and water-related activities was recorded. We ascertained residential concentrations of trihalomethanes through regulatory records and ad hoc sampling campaigns and estimated route-specific trihalomethane uptake by trimester and for whole pregnancy. We examined single nucleotide polymorphisms and copy number variants in disinfection by-product metabolizing genes in nested case-control studies. Results: Average levels of trihalomethanes ranged from around 10 μg/L to above the regulatory limits in the EU of 100 μg/L between centers. There was no association between birth weight and total trihalomethane exposure during pregnancy (β = 2.2 g in birth weight per 10 μg/L of trihalomethane, 95% confidence interval = 3.3, 7.6). Birth weight was not associated with exposure through different routes or with specific trihalomethane species. Exposure to trihalomethanes was not associated with low birth weight (odds ratio [OR] per 10 μg/L = 1.02, 95% confidence interval = 0.95, 1.10), small-for-gestational age (OR = 0.99, 0.94, 1.03) and preterm births (OR = 0.98, 0.9, 1.05). We found no gene-environment interactions for mother or child polymorphisms in relation to preterm birth or small-for-gestational age. Conclusions: In this large European study, we found no association between birth outcomes and trihalomethane exposures during pregnancy in the total population or in potentially genetically susceptible subgroups. © 2016 Wolters Kluwer Health, Inc.
Epidemiology

hal-01392115
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01392115
DOI : 10.1097/EDE.0000000000000544
PUBMED : 27468006

Éditeur(s) : Université des Antilles et de la Guyane
Résumé : The need for an integrated approach to fisheries is now widely affirmed, including the FAO, in particular in the context of tropical artisanal fisheries. These small-scale fisheries, often multispecies are very important in terms of production, employment and food security. However these fisheries and the exploited resources are often characterized by a lack of data making difficult their management within an ecosystem approach, and by the ecological and economic system complexities including trophic and technological interactions. This thesis aims to contribute to the development of bioeconomic tools for small tropical fisheries in a sustainable management perspective based on the ecosystem approach. In this perspective, the French Guiana coastal fishery constitutes an interesting case study. The thesis proposes multi-criteria evaluations, complex bioeconomic models and viable management scenarios for this fishery. At first, multivariate statistical analysis suggests a satisfactory overall status of the fishery in terms of sustainability. However, some performance differences are noted within the fishery, particularly at border areas. Also, management improvements are proposed. Then, through bioeconomic modeling, projections of different fishing scenarios show that, in the long-term, the current exploitation level may not be consistent with the future increase of local demand and a loss of biodiversity may occur. A scenario called "co-viability" reconciling ecological, economic and social objectives, with a high probability of achievement is exhibited. Finally, the comparison of optimal behavior in cooperative and non-cooperative conditions, confirms that harvest levels are greater when actors do not cooperate. Furthermore, it is shown that the state of the ecosystem depends on the fishing strategies and the type of interaction between species. Beyond the diagnosis made for the case study, the method is promising in the context of small tropical fisheries, while the co-viability approach allows finding the exploitation conditions under which ecological and socio-economic sustainability are meet, what the conventional fisheries management generally do not allow.
La nécessité d’une approche intégrée des pêches est actuellement largement affirmée, notamment par la FAO, en particulier dans le contexte des pêcheries artisanales tropicales. Ces pêcheries à petites échelles, souvent multi-spécifiques sont très importantes en termes d’emploi et de production, y compris pour la sécurité alimentaire. Néanmoins ces pêcheries et la biodiversité exploitées sont souvent marquées, d’une part, par le manque de données rendant difficile leur gestion dans le cadre d’une approche écosystémique, d’autre part, par la complexité des systèmes écologiques et économiques sous-jacents incluant interactions trophiques et techniques. Cette thèse contribue à la mise au point d’outils bioéconomiques adaptés aux petites pêcheries tropicales dans la perspective d’une gestion durable des pêches fondée sur l’approche écosystémique. Dans cette perspective, la pêcherie côtière en Guyane Française constitue un cas d’étude particulièrement fécond. La thèse propose ainsi des évaluations multi-critères, des modèles bioéconomiques complexes et des scénarios de gestion viable pour cette pêcherie. Dans un premier temps l’analyse statistique multivariée suggère un statut global satisfaisant de la pêcherie en termes de durabilité. Cependant des différences de performance sont notées au sein de la pêcherie, notamment au niveau des zones frontalières. Aussi des améliorations dans le mode de gestion sont proposées. Ensuite, à travers la modélisation bioéconomique, les projections des différents scénarios de pêche montrent qu’à long terme le niveau d’exploitation actuel peut ne pas être en adéquation avec la future augmentation de la demande locale et qu’une perte de biodiversité peut avoir lieu. Un scenario dit de "co-viabilité" conciliant des objectifs à la fois écologique, économique et social, avec une probabilité de réalisation satisfaisante, est mis en exergue. Enfin, la comparaison des comportements optimaux en situation coopératif et non coopératif, montre dans quelle mesure la viabilité est favorisée quand les acteurs coopèrent. Au-delà du diagnostic apporté pour le cas d’étude, la méthode utilisée s’avère prometteuse dans le contexte des petites pêcheries tropicales, tandis que l’approche de co-viabilité permet de trouver les modalités d’exploitation dans le cadre de compromis entre durabilité écologique et socio-économique, ce que les principes de gestion halieutiques traditionnels ne permettent généralement pas.

Droits : 2013 Université des Antilles et de la Guyane
http://archimer.ifremer.fr/doc/00144/25492/23646.pdf
http://archimer.ifremer.fr/doc/00144/25492/

Éditeur(s) : Gauthier-Villars
Résumé : Mud fields located In the inner part of shelves in front of large estuaries are preferential environments for the investigation of the mechanisms and evolution in time of the supply of such sedimentary bodies. The study of different constituents of the particulate organic matter trapped in the sediments of the West Gironde mud patch contributes to the knowledge of the input origins. This study was carried out with different techniques, including pyrolysis-gas chromatography-mass spectrometry and high performance liquid chromatography, on samples from a core collected in the centre of the mud field. At the bottom of the core, the increase of sugars, amino-sugars and some aromatic hydrocarbons may indicate a more marine character of organic components. The same appears to be the case at the top of the core, where, despite a finer sedimentation, biochemical characteristics could show a more pronounced marine influence than in the middle part. In the middle part of the core, on the other hand, the increase in phenols could result from an increase in lignin-derived. terrestrial inputs. The increase in pyrolysis-derived cyclopentenone may indicate the same terrestrial influence, because this component has its origin in aliphatic polycarboxylic acids resulting from sail leaching. The continental character of the sedimentation is also reflected in the increase of the silt-clay fractions representative of suspended matter originating in the Gironde estuary, associated with a slight carbonate decrease. The taxonomic significance of some phenols is noteworthy: this is especially the case of the cinnamyls which, in the middle part of the core, emphasize the input of herbaceous debris and of the hydroxybenzyls which, at the bottom, provide evidence of the algal origin of part of the organic material. Thus, by means of pyrolysis results and HPLC phenol analysis, it is possible to establish the more or less continental signature of organic components trapped in the ''Ouest-Gironde'' mud patch. This study of organic matter, which confirms earlier sedimentological and micropaleontological data, constitutes a new approach, adapted to the identification of the origin of carbon sources.
Oceanolica Acta (0399-1784) (Gauthier-Villars), 1997 , Vol. 20 , N. 5 , P. 687-695

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00093/20426/18093.pdf
http://archimer.ifremer.fr/doc/00093/20426/

Éditeur(s) : EDP Sciences
Résumé : Market position and its evolution were analysed in nine key fish and cephalopod species subject to long-term changes, using the Bay of Biscay fisheries as a case study. Although such long term changes have already been documented, and in some cases shown to be related to the impacts of fishing, changes in the physical environment, or both, relatively little work has been devoted to their potential consequences in economic terms. The nature and extent of these consequences was determined in the present study by looking at the composition of the affected fish production, and the status of different fish products on the markets. We propose a methodology to characterize market position for this set of nine species. The selected species represent a significant part of the gross turnover of French fishing fleets operating in the bay. These species were characterized in terms of their potential sensitivity to fishing and changes in environmental conditions due to global warming. We separated species potentially positively (Engraulis encrasicolus and Lophius budegassa) and negatively affected (Pollachius pollachius and Lophius piscatorius) by warming. Evolution of the value of production of the nine species was then depicted using analysis of macro-economic index (production and potential consumption) and price indices. This revealed the relatively high sensitivity of domestic production to the market crisis that occurred in France in the early 1990s, compared to imported and exported products. The relative position of individual species, with respect to the market and its evolution between 1990 and 2005, was analyzed by multi-factorial analysis. Results derived from the analysis clearly distinguish two groups of species, the first characterized by higher prices (monkfish, Nephrops, sole, seabass) and the second by larger volumes available on the French market (pollack, hake, anchovy, sardine, cuttlefish). We conclude that a major part (69 to 87%) of the gross turnover associated with catches of these fish species in the Bay of Biscay remains potentially unaffected by long-term changes related to climate.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2008-07 , Vol. 21 , N. 3 , P. 307-316

Droits : EDP Sciences, IFREMER, IRD 2008
http://archimer.ifremer.fr/doc/2008/publication-4716.pdf
DOI:10.1051/alr:2008047
http://archimer.ifremer.fr/doc/00000/4716/

Éditeur(s) : HAL CCSD Elsevier
Résumé : Vegetation phenology is the study of the timing of seasonal events that are considered to be the result of adaptive responses to climate variations on short and long time scales. In the field of remote sensing of vegetation phenology, phenological metrics are derived from time series of optical data. For that purpose, considerable effort has been specifically focused on developing noise reduction and cloud-contaminated data removal techniques to improve the quality of remotely-sensed time series. Comparative studies between time series composed of satellite data acquired under clear and cloudy conditions and from radiometric data obtained with high accuracy from ground-based measurements constitute a direct and effective way to assess the operational use and limitations of remote sensing for predicting the main plant phenological events. In the present paper, we sought to explicitly evaluate the potential use of MODerate resolution Imaging Spectroradiometer (MODIS) remote sensing data for monitoring the seasonal dynamics of different types of vegetation cover that are representative of the major terrestrial biomes, including temperate deciduous forests, evergreen forests, African savannah, and crops. After cloud screening and filtering, we compared the temporal patterns and phenological metrics derived from in situ NDVI time series and from MODIS daily and 16-composite products. We also evaluated the effects of residual noise and the influence of data gaps in MODIS NDVI time series on the identification of the most relevant metrics for vegetation phenology monitoring. The results show that the inflexion points of a model fitted to a MODIS NDVI time series allow accurate estimates of the onset of greenness in the spring and the onset of yellowing in the autumn in deciduous forests (RMSE <= one week). Phenological metrics identical to those provided with the MODIS Global Vegetation Phenology product (MDC12Q2) are less robust to data gaps, and they can be subject to large biases of approximately two weeks or more during the autumn phenological transitions. In the evergreen forests, in situ NDVI time series describe the phenology with high fidelity despite small temporal changes in the canopy foliage. However, MODIS is unable to provide consistent phenological patterns. In crops and savannah, MODIS NDVI time series reproduce the general temporal patterns of phenology, but significant discrepancies appear between MODIS and ground-based NDVI time series during very localized periods of time depending on the weather conditions and spatial heterogeneity within the MODIS pixel. In the rainforest, the temporal pattern exhibited by a MODIS 16-day composite NDVI time series is more likely due to a pattern of noise in the NDVI data structure according to both rainy and dry seasons rather than to phenological changes. More investigations are needed, but in all cases, this result leads us to conclude that MODIS time series in tropical rainforests should be interpreted with great caution. (C) 2013 Elsevier Inc. All rights reserved.
ISSN: 0034-4257

hal-01032407
https://hal.archives-ouvertes.fr/hal-01032407
DOI : 10.1016/j.rse.2013.01.010

Éditeur(s) : HAL CCSD National Institute of Environmental Health Sciences (NIEHS) National Institute of Environmental Health Sciences
Résumé : International audience
Long-term exposure to persistent pollutants with hormonal properties (endocrine-disrupting chemicals, EDCs) may contribute to the risk of prostate cancer (PCa). However, epidemiological evidence remains limited. We investigated the relationship between PCa and plasma concentrations of universally widespread pollutants, in particular p,p'-dichlorodiphenyl dichloroethene (DDE) and the non-dioxin like polychlorinated biphenyl congener 153 (PCB153). We evaluated before treatment 576 men with newly diagnosed PCa and 655 controls in Guadeloupe (French West Indies). Exposure was analyzed according to case-control status. Associations were assessed by unconditional logistic regression analysis, controlling for confounding factors. Missing data were handled by multiple imputation. We estimated a significant positive association between DDE and PCa (adjusted odds ratio [OR] 1.53; 95% CI 1.02, 2.30 for the highest versus lowest quintile of exposure; PTrend = 0.01). PCB153 was inversely associated with PCa (OR 0.30; 95% CI 0.19, 0.47 for the highest versus lowest quintile of exposure values; PTrend < 0.001). Also, PCB153 was more strongly associated to low-grade than high grade PCa. Associations of PCa with DDE and PCB153 were in opposite directions. This may reflect differences in the mechanisms of action of these EDCs, and although our findings need to be replicated in other populations, they are consistent with complex effects of EDCs on human health.
ISSN: 0091-6765

hal-01118553
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01118553
DOI : 10.1289/ehp.1408407
PUBMED : 25493337

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Holoprosencephaly (HPE) is the most common congenital cerebral malformation, characterized by impaired forebrain cleavage and midline facial anomalies. Heterozygous mutations in 14 genes have been associated with HPE, and are often inherited from an unaffected parent underlying complex genetic bases. It is now emerging that HPE may result from a combination of multiple genetic events, rather than from a single heterozygous mutation. To explore this hypothesis, we undertook whole exome sequencing (WES) and targeted high-throughput sequencing approaches to identify mutations in HPE subjects. We report here two HPE families in which two mutations are implicated in the disease. In the first family presenting two fetuses with alobar and semi-lobar HPE, we found mutations in two genes involved in HPE, SHH and DISP1, inherited respectively from the father and the mother. The second reported case is a family with a 9-year old girl presenting lobar HPE, harbouring two compound heterozygous mutations in DISP1. Together, these cases of digenic inheritance SHH/DISP1 and autosomal recessive HPE suggest that in some families, several genetic events are necessary to cause HPE. This study highlights the complexity of HPE inheritance and has to be taken into account by clinicians to improve HPE genetic counseling.
ISSN: 0009-9163

hal-01259228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259228
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259228/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259228/file/Complex%20mode%20of%20inheritance%20in%20holoprosencephaly_accepted.pdf
DOI : 10.1111/cge.12722