Éditeur(s) : HAL CCSD Elsevier
Résumé : This study analyzes the records of several trace metals sensitive to redox conditions in continental shelf sediments off Concepcion, Chile (36 degrees S). The continental margin off Concepcion (36 S; 73 W) lies beneath an important upwelling center characterized by high primary production rates and, consequently, high fluxes of organic matter. In spring and summer, this material settles to the seafloor where it decays, producing periods of very low oxygen content in bottom waters (<1 mL L-1). In addition, an oxygen minimum zone develops at similar to 100-400 m water depth, where dissolved oxygen levels are <0.5 mL L-1. This situation changes during strong El Nino events, when dissolved oxygen at the bottom increases drastically (>1 mL L-1).;The goals of this study were to determine the input of trace metals to the sediment and to decipher how this information can be used to reveal variations in primary productivity or bottom oxygenation. Gravity cores collected at two stations - VG06-2 over the mid-shelf station (88 m water depth, upper boundary of the oxygen minimum zone) and VG06-3 over the outer shelf (120 m water depth, within the oxygen minimum zone) - were sampled for high resolution profiles (1 cm) of trace metals, biogenic opal, stable isotopes, and total organic carbon. The results suggest that the variability in the trace metal distribution on the continental shelf off Concepcion is determined by redox conditions and the organic carbon flux to the bottom. Some sections of the sediment cores from the outer shelf showed appreciable authigenic enrichment of U, Cd, and Mo (EF: 5-10, 2-5, and 10-16 respectively) along with heavier values of delta N-15, suggesting periods of suboxic conditions. During these periods, fluxes of organic material to the bottom were higher, as indicated by elevated TOC and opal contents. Alternating periods of higher and lower trace metal contents were not observed mid-shelf as they were on the outer shelf. Rather, the mid-shelf samples showed authigenic enrichment of U, Cd, and Mo (EF: 1-6, 4-5, and 10-20, respectively) throughout the core except in a 10-cm-thick gray layer. In general, authigenic enrichment of U. Mo, and Cd occurred at both sites, coincident with olive green layers in the cores. These layers were associated with periods of elevated primary productivity and suboxic conditions. Such periods did not seem to last as long as the oxygenated periods, which had higher inputs of refractive detrital material, coincident with the occurrence of distinct gray sediment layers.
ISSN: 0079-6611

hal-00682159
https://hal.archives-ouvertes.fr/hal-00682159
DOI : 10.1016/j.pocean.2011.07.010

Éditeur(s) : Academic Press Ltd- Elsevier Science Ltd
Résumé : Ensuring the sustainability of fish resources necessitates understanding their interaction with coastal habitats, which is becoming ever more challenging in the context of ever increasing anthropogenic pressures. The ability of coastal lagoons, exposed to major sources of disturbance, to provide resources and suitable habitats for growth and survival of juvenile fish is especially important. We analysed three lagoons with different ecological statuses and habitat quality on the basis of their eutrophication and ecotoxicity (Trix test) levels. Fish abundances were sampled using fishing and horizontal beaming acoustic surveys with the same protocols in the same year. The relative abundance of Anguilla anguilla, Dicentrarchus labrax or the Mugilidae group was not an indicator of habitat quality, whereas Atherina boyeri and Sparus aurata appeared to be more sensitive to habitat quality. Fish abundance was higher in the two lagoons with high eutrophication and ecotoxicity levels than in the less impacted lagoon, while fish sizes were significantly higher in the two most severely impacted lagoons. This leads us to suggest low habitat quality may increase fish growth rate (by the mean of a cascading effect), but may reduce lagoon juvenile abundance by increasing larval mortality. Such a hypothesis needs to be further validated using greater investigations which take into account more influences on fish growth and recruitment in such variable environments under complex multi-stressor conditions.
Estuarine Coastal And Shelf Science (0272-7714) (Academic Press Ltd- Elsevier Science Ltd), 2013-07 , Vol. 126 , P. 1-6

Droits : 2013 Elsevier Ltd. All rights reserved
http://archimer.ifremer.fr/doc/00148/25963/24083.pdf
DOI:10.1016/j.ecss.2013.03.011
http://archimer.ifremer.fr/doc/00148/25963/

Éditeur(s) : HAL CCSD BMJ Publishing Group
Résumé : International audience
OBJECTIVES: Many women who work during pregnancy are occupationally exposed to toxicants. The developing central nervous system is highly vulnerable to neurotoxicants such as solvents. Although the neurotoxicity of solvents to adults is well established, very few studies have examined their effects on children's behaviour following prenatal exposure. METHODS: Women from the Perturbateurs endocriniens: Étude Longitudinale sur les Anomalies de la Grossesse, l'Infertilité et l'Enfance (PELAGIE) mother-child cohort (including 3005 working women) were recruited in Brittany (France) between 2002 and 2006, at the beginning of pregnancy, to assess occupational exposure to solvents at that time. Child behaviour was documented at age 2 by mothers (n=1278) assessing components of attention deficit/hyperactivity, aggression, opposition and emotionality. We used a multiple linear regression analysis to evaluate the association between occupational solvent exposure and children's behaviour. Complementary sensitivity analyses allowed us to handle missing data, due mostly to attrition. RESULTS: 20% of women reported occasional exposure and 31% regular exposure to solvents. Children prenatally exposed were more likely to have higher scores of attention deficit/hyperactivity and aggression, and dose-response relations were observed. CONCLUSIONS: The dose-response effect and the high prevalence of children potentially exposed to solvents from their mother's workplace exposure underline the public health relevance of this result. Our results should be replicated in further studies designed to identify which solvents are most deleterious and to assess child behaviour at school age.
ISSN: 1351-0711

inserm-00795043
http://www.hal.inserm.fr/inserm-00795043
http://www.hal.inserm.fr/inserm-00795043/document
http://www.hal.inserm.fr/inserm-00795043/file/Occupationnal_solvent_exposure_child_behavior_HAL.pdf
DOI : 10.1136/oemed-2012-100892

Éditeur(s) : Elsevier
Résumé : In order to provide reliable scientific advice and support for fisheries management, it is necessary to evaluate the biological and economic sustainability of complex fisheries, such as multi-species multi-fleet fisheries. Existing policy-screening modelling tools are not fully suitable in this purpose due to either an over-simplified description of population dynamics, or due to the lack of consideration of economic aspects. In this paper, we present a package that enables quantitative bioeconomic assessment of management scenarios. Population dynamics is described through spatially- and seasonally-explicit models. Exploitation dynamics is characterized by several fishing activities with specific spatial and seasonal features, and practiced by several kinds of vessels with specific technical characteristics. Exploitation costs and revenues are considered at several levels: the fishing trip, the fishing unit (vessel and crew), and the vessel owner. The model is generic and can be used for different types of fisheries. A database is attached to the software for the storage and updating of information for each fishery. This includes the specification of model dimensions and of the parameters describing populations and exploitation. Several model assumptions regarding either population or exploitation may be adapted to suit a specific fishery. Both policies and corresponding fishers' response may be interactively specified through JAVA (TM) scripts. This version of ISIS-Fish allows for the calculation of biological and economic consequences of a range of policies, including conventional ones like catch and effort controls, and alternative policies such as marine protected areas. To facilitate policy-screening in a high-dimension parameter space, the software includes features, like interfaces for sensitivity analysis and simulation queues. (C) 2009 Elsevier B.V. All rights reserved.
Ecological Modelling (0304-3800) (Elsevier), 2009-04 , Vol. 220 , N. 7 , P. 1013-1033

Droits : 2009 Elsevier B.V. All rights reserved.
http://archimer.ifremer.fr/doc/2009/publication-6782.pdf
DOI:10.1016/j.ecolmodel.2009.01.007
http://archimer.ifremer.fr/doc/00000/6782/

Éditeur(s) : HAL CCSD Elsevier
Résumé : Over-exploitation and fragmentation are serious problems for tropical forests. Most sustainable forest management practices avoid clear-cuts and apply selective logging systems focused on a few commercial species. We applied a simulation model to estimate the impact of such selective logging scenarios on the genetic diversity and demography of four tropical tree species from French Guiana. The simulations used data on genetic and demographic composition, growth, phenology and pollen and seed dispersal obtained for Dicorynia guianensis, Sextonia rubra, Symphonia globulifera and Vouacapoua americana at the experimental site in Paracou. Whereas Symphonia globulifera serves as a model for a species with low logging pressure, the other three species represent the most exploited tree species in French Guiana. In simulations with moderate logging, typical for French Guiana, with large cutting diameter (>60 cm diameter) and long cutting cycles (65 years), the two species V. americana and Sextonia rubra were not able to recover their initial stock at the end of the rotation period, with a large decrease in the number of individuals and in basal area. Under a more intensive logging system (cutting diameter >45 cm diameter, cutting cycles of 30 years) that is common practice in the Brazilian Amazon, only Symphonia globulifera showed no negative impact. Generally, the differences between the genetic parameters in the control scenarios without logging and the logging scenarios were surprisingly small. The main reasons for this were the overlapping of generations and the effective dispersal ability of gene vectors in all species, which guarantee relative homogeneity of the genetic structure in different age classes. Nevertheless, decreasing the population size by logging reduced the number of genotypes and caused higher genetic distances between the original population and the population at the end of the logging cycles. Sensitivity analysis showed that genetic changes in the logging scenarios were principally determined by the growth, densities and cutting diameter of each species, and only to a very small extent by the reproductive system including factors such as pollen and seed dispersal and flowering phenology
ISSN: 0006-3207

hal-01032050
https://hal.archives-ouvertes.fr/hal-01032050
DOI : 10.1016/j.biocon.2006.02.014

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The aim of this paper is twofold. First, it is to extend the sensitivity analysis framework, developed recently for variational inequalities, to mixed equilibrium problems. The second is to propose iterative methods for solving this kind of problems. In the process, we establish an equivalence between an extended version of Wiener-Hopf equations and the given problems relying on a generalization of the Yosida approximation notion. Our results generalize results obtained for optimization, variational inequalities, complementarity problems, and problems of Nash equilibria.
ISSN: 0898-1221

hal-00779234
https://hal.univ-antilles.fr/hal-00779234
DOI : 10.1016/S0898-1221(02)00218-3

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Androgen signaling, via the androgen receptor (AR), is crucial in mediating prostate cancer (PCa) initiation and progression. Identifying new downstream effectors of the androgens/AR pathway will allow a better understanding of these mechanisms and could reveal novel biomarkers and/or therapeutic agents to improve the rate of patient survival. We compared the microRNA expression profiles in androgen-sensitive LNCaP cells stimulated or not with 1 nM R1881 by performing a high-throughput reverse transcriptase-quantitative PCR and found that miR-135a was upregulated. After androgen stimulation, we showed that AR directly activates the transcription of miR-135a2 gene by binding to an androgen response element in the promoter region. Our findings identify miR-135a as a novel effector in androgens/AR signaling. Using xenograft experiments in chick embryos and adult male mice, we showed that miR-135a overexpression decreases in vivo invasion abilities of prostate PC-3 cells. Through in vitro wound-healing migration and invasion assays, we demonstrated that this effect is mediated through downregulating ROCK1 and ROCK2 expression, two genes that we characterized as miR-135a direct target genes. In human surgical samples from prostatectomy, we observed that miR-135a expression was lower in tumoral compared with paired adjacent normal tissues, mainly in tumors classified with a high Gleason score (⩾8). Moreover, miR-135a expression is lower in invasive tumors, showing extraprostatic extension, as compared with intraprostatic localized tumors. In tumor relative to normal glands, we also showed a more frequently higher ROCK1 protein expression determined using a semi-quantitative immunohistochemistry analysis. Therefore, in tumor cells, the lower miR-135a expression could lead to a higher ROCK1 protein expression, which could explain their invasion abilities. The highlighted relationship between miR-135a expression level and the degree of disease aggressiveness suggests that miR-135a may be considered as a prognostic marker in human PCa.Oncogene advance online publication, 28 July 2014; doi:10.1038/onc.2014.222.
ISSN: 0950-9232

hal-01063902
https://hal.archives-ouvertes.fr/hal-01063902
https://hal.archives-ouvertes.fr/hal-01063902/file/Androgen-regulated%20microRNA-135a.pdf
DOI : 10.1038/onc.2014.222
PUBMED : 25065599

Éditeur(s) : Agrocampus Ouest
Résumé : The origin of fish stocks variability is a key question in fisheries science. The exploitation indeed has an important effect in terms of biomass reduction, but environmental forcing is of central interest as it affects numerous key biological processes. Recent theoretical results have shown that the nature of the environmental fluctuations, the environmental noise, has important ecological consequences on populations and particularly on their fluctuations. In addition the effects of exploitation, that are not a simple removal of individuals but also profoundly modifies the demography, the structure and the trophic interactions of fish stocks, can interact with environmental effects. Through an extensive analysis of time series we aim at understanding the effects of environmental noise on fish stocks variability, according to their biological characteristics (life-history traits) and their exploitation. A technique of time series comparison allows to propose that the fluctuations of Atlantic large pelagics are inherited from the interaction between environmental effects, endogenous dynamics and exploitation. We then show that the colour of environmental noise affects the variability of time series, its effects depending on the life-history traits of species. Finally, preliminary results on bentho-demersal and pelagic stocks from the North Atlantic suggest that the exploitation increases the sensitivity of fish stocks to the colour of environmental noise and affects their variability, according to their life-history traits.
L'origine de la variabilité des stocks de pêche est une question centrale en halieutique. Si l'exploitation tient un rôle important dans la réduction de biomasse, le forçage environnemental affecte de nombreux processus biologiques clés. Des résultats théoriques récents ont montré que la nature des fluctuations environnementales, la couleur du bruit environnemental, avait des implications écologiques importantes sur les populations et notamment sur leurs fluctuations. De plus, les effets environnementaux peuvent agir en interaction avec l'exploitation qui ne consiste pas en un simple prélèvement d'individus, mais qui modifie profondément la démographie, la structure et les interactions trophiques des stocks. Au travers de l'analyse extensive de séries temporelles, on essaye ici de comprendre les effets de la couleur du bruit environnemental sur la variabilité des stocks en fonction de leurs caractéristiques biologiques (traits d'histoire de vie) et de leur état d'exploitation. Le développement d'une technique de comparaison des séries temporelles permet de proposer que les fluctuations des grands pélagiques de l'Atlantique sont héritées de l'interaction entre effets environnementaux, dynamique interne et dynamique de l'exploitation. On montre ensuite que la couleur du bruit environnemental affecte la variabilité des séries temporelles, mais que son effet dépend des traits d'histoire de vie des espèces. Enfin, des résultats préliminaires sur les stocks bentho-démersaux et pélagiques de l'Atlantique Nord, suggèrent que l'exploitation augmente la sensibilité des stocks à la couleur du bruit environnemental et affecte leur variabilité en fonction de leurs traits d'histoire de vie.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2008/these-6596.pdf
http://archimer.ifremer.fr/doc/00000/6596/

Éditeur(s) : HAL CCSD Inter Research
Résumé : International audience
The main objective of the VULSACO (VULnerability of SAndy COasts to climate change and anthropic pressure) project was to investigate present day and potential future vulnerability of sandy coasts at the 2030 horizon, i.e. on a time scale related to climate variability. The method, based on a multidisciplinary approach bringing together geologists, geographers, physicists, social psychologists, engineers and stakeholders, was structured around 4 axes: field data analysis; numerical modelling; analysis of governance and stakeholder perceptions; and development of vulnerability indexes. This approach was designed to investigate vulnerability at a local scale and was applied to 4 contrasting beaches located in France: Sète Lido (Mediterranean Sea), Truc Vert and La Tresson beaches (Atlantic Ocean), and Dewulf (English Channel). The results focus on decadal and multi-annual beach trends at the Truc Vert beach site. There is almost no trend in beach volume at Truc Vert beach, although there is a variation in this parameter on a cycle of 2 to 3 yr, with variations related to wave energy and probably to indexes of climate variability. Numerical modelling identified the sensitivity of beach responses to changes in wave height and direction, especially in terms of subtidal morphology and the potential development of shoreline instability. Together with the observed offshore wave angle at the Biscay Buoy, these model results suggest that a potential change in wave angle due to climate variability could significantly modify the bars' morphology. The combination of data analysis and numerical modelling contributed to the development of vulnerability indexes designed for sandy coasts, which take into account climate-dependant variables such as waves. This allowed the differentiation of the sites in terms of vulnerability to erosion: Sète Lido and Truc Vert beach were the most and least vulnerable sites, respectively. These indexes help in identifying the dominant components of beach vulnerability, and provide potential for the study of how anthropogenic factors affect vulnerability. The study of stakeholder perceptions and decision-making with regard to climate-related risk also highlighted potential anthropogenic effects on beach vulnerability, and identified possible site-specific outcomes.
ISSN: 0936-577X

hal-00843946
https://hal-brgm.archives-ouvertes.fr/hal-00843946
DOI : 10.3354/cr01153

Éditeur(s) : Gauthier-Villars
Résumé : The Scopoletin-Peroxidase fluorescence decay method has been developed using standard additions and a flow injection manifold for hydrogen peroxide (H2O2) determination in marine waters. The limit of detection of the method was optimized using stored milli-Q water with a minimum of 5 nM (3 sigma). The method was found to be linear from 5 to 700 nM, with an approximate relative standard deviation of 10%. This accuracy was verified on both milli-Q and natural waters running systematically duplicate analysis. The validity and the sensitivity of the technique was studied through the influence of pH, salinity and the dissolved organic matter (DOM) concentration. Standard additions avoided all matrix and experimental interferences, making it possible to use this method under any field conditions and on ''humic-rich'' waters. Additionally, the flow injection manifold improved the accuracy and the runtime of the analytical procedure and simplified the field manipulation.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1995 , Vol. 18 , N. 3 , P. 353-361

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00097/20784/18409.pdf
http://archimer.ifremer.fr/doc/00097/20784/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The anisotropy of vibrational properties influences the acoustic behaviour of wooden pieces and their dependence on grain angle (GA). As most pieces of wood include some GA, either for technological reasons or due to grain deviations inside trunks, predicting its repercussions would be useful. This paper aims at evaluating the variability in the anisotropy of wood vibrational properties and analysing resulting trends as a function of orientation. GA dependence is described by a model based on transformation formulas applied to complex compliances, and literature data on anisotropic vibrational properties are reviewed. Ranges of variability, as well as representative sets of viscoelastic anisotropic parameters, are defined for mean hardwoods and softwoods and for contrasted wood types. GA-dependence calculations are in close agreement with published experimental results and allow comparing the sensitivity of different woods to GA. Calculated trends in damping coefficient (tanδ) and in specific modulus of elasticity (E′/ρ) allow reconstructing the general tanδ-E′/ρ statistical relationships previously reported. Trends for woods with different mechanical parameters merge into a single curve if anisotropic ratios (both elastic and of damping) are correlated between them, and with axial properties, as is indicated by the collected data. On the other hand, varying damping coefficient independently results in parallel curves, which coincide with observations on chemically modified woods, either "artificially", or by natural extractives.
ISSN: 0043-7719

hal-00804242
https://hal.archives-ouvertes.fr/hal-00804242
https://hal.archives-ouvertes.fr/hal-00804242/document
https://hal.archives-ouvertes.fr/hal-00804242/file/Anisotropy_wood_variational_properties_Bremaud_al_2011.pdf
DOI : 10.1007/s00226-010-0393-8

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : The present work aimed at better understanding metal and metalloid bioaccumulation in the edible Pacific blue shrimp Litopenaeus stylirostris, using both laboratory and field approaches. In the laboratory, the bioaccumulation kinetics of Ag, Cd, Co, Cr, and Zn have been investigated in shrimp exposed via seawater and food, using the corresponding gamma-emitting radiotracers (Ag-110m, Cd-109, Co-57, Cr-51, and Zn-65) and highly sensitive nuclear detection techniques. Results showed that hepatopancreas and intestine concentrated the metals to the highest extent among the blue shrimp organs and tissues. Moulting was found to play a non negligible detoxification role for Co, Cr and, to a lesser extent, Zn. Metal retention by L stylirostris widely varied (from a few days to several months), according to the element and exposure pathway considered (a given metal was usually less strongly retained when ingested with food than when it was taken up from the dissolved phase). In the field study, Ag, As, Cd, Co, Cr, Cu, Mn, Ni, and Zn were analysed in shrimp collected from a New Caledonian aquaculture pond. Metal concentrations in the shrimp muscles were generally relatively low and results confirmed the role played by the digestive organs and tissues in the bioaccumulation/storage/detoxification of metals in the Pacific blue shrimp. Preliminary risk considerations indicate that consumption of the shrimp farmed in New Caledonia is not of particular concern for human health. (C) 2010 Elsevier Ltd. All rights reserved.
Marine Pollution Bulletin (0025-326X) (Pergamon-elsevier Science Ltd), 2010 , Vol. 61 , N. 7-12 , P. 576-584

Droits : 2010 Elsevier Ltd All rights reserved.
http://archimer.ifremer.fr/doc/00014/12528/9869.pdf
DOI:10.1016/j.marpolbul.2010.06.035
http://archimer.ifremer.fr/doc/00014/12528/

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
: Estradiol signaling is ideally suited for analyzing molecular and functional linkages between the different layers of information directing transcriptional regulations: DNA sequence, chromatin modifications and the spatial organization of the genome. Hence, estrogen receptor (ER) can bind at a distance from its target genes and engages timely and spatially coordinated processes to regulate their expression. In the context of the coordinated regulations of co-linear genes, identifying which ER binding sites (ERBSs) regulate a given gene still remains a challenging question. Here, we investigated the coordination of such regulatory events at a 2 Mb genomic locus containing the estrogen-sensitive TFF cluster of genes in breast cancer cells. We demonstrated that this locus exhibits a hormone and cohesin-dependent reduction in the plasticity of its three-dimensional organization that allows multiple ERBSs to be dynamically brought to the vicinity of estrogen-sensitive genes. Additionally, by using triplex forming oligonucleotides, we could precisely document the functional links between ER engagement at given ERBSs and the regulation of particular genes. Hence, our data evidence a formerly suggested cooperation of enhancers towards gene regulations, and also show that redundancy between ERBSs can occur.
ISSN: 0270-7306

hal-00984591
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00984591
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00984591/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00984591/file/Mol._Cell._Biol.-2014-Quintin-MCB.00918-13.pdf
DOI : 10.1128/MCB.00918-13

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Both flow field heterogeneity and mass transfer between mobile and immobile domains have been studied separately for explaining observed anomalous transport. Here we investigate non-Fickian transport using high-resolution 3-D X-ray microtomographic images of Berea sandstone containing microporous cement with pore size below the setup resolution. Transport is computed for a set of representative elementary volumes and results from advection and diffusion in the resolved macroporosity (mobile domain) and diffusion in the microporous phase (immobile domain) where the effective diffusion coefficient is calculated from the measured local porosity using a phenomenological model that includes a porosity threshold ( inline image) below which diffusion is null and the exponent n that characterizes tortuosity-porosity power-law relationship. We show that both flow field heterogeneity and microporosity trigger anomalous transport. Breakthrough curve (BTC) tailing is positively correlated to microporosity volume and mobile-immobile interface area. The sensitivity analysis showed that the BTC tailing increases with the value of inline image, due to the increase of the diffusion path tortuosity until the volume of the microporosity becomes negligible. Furthermore, increasing the value of n leads to an increase in the standard deviation of the distribution of effective diffusion coefficients, which in turn results in an increase of the BTC tailing. Finally, we propose a continuous time random walk upscaled model where the transition time is the sum of independently distributed random variables characterized by specific distributions. It allows modeling a 1-D equivalent macroscopic transport honoring both the control of the flow field heterogeneity and the multirate mass transfer between mobile and immobile domains.
ISSN: 0043-1397

hal-01278285
https://hal.archives-ouvertes.fr/hal-01278285
DOI : 10.1002/2015WR017645

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : National audience
The sources of exposure during diseases due to Aspergillus fungi in cystic fibrosis patients are still poorly explored. We assessed home fungal exposure in patients suffering from cystic fibrosis and analysed its impact on the presence of Aspergillus biological markers, the colonisation of airways, as well as the sensitization and Aspergillus serology. Between March 2012 and August 2012, 34 patients benefited from a visit performed by a home environment medical adviser including sampling for mycological analysis. The number of colonies of Aspergillus was not significantly different in the various sampling sites (P = 0.251), but the number of non-Aspergillus colonies was much higher in the kitchen (P = 0.0045). Subsequently, home fungal exposure was compared between the groups “absence of Aspergillus-related markers” and “presence of Aspergillus-related markers”. Home exposure to Aspergillus (P = 0.453) and non-Aspergillus (P = 0.972) flora was not significant between the 2 groups. Within this series of 34 patients that should be expanded, we note an absence of clear relationship between home exposure and the Aspergillus-linked markers in patients suffering from cystic fibrosis. This result should be taken into account regarding too restrictive hygiene advices provided to families, given the fact that fungal exposure can also results from activities performed away from home.
La source d’exposition au cours des pathologies aspergillaires du patient atteint de mucoviscidose reste encore peu explorée. Nous avons évalué l’exposition fongique domiciliaire chez des patients atteints de mucoviscidose, et analysé son impact sur la présence de marqueurs biologiques aspergillaires, colonisation des voies aériennes, ainsi que sensibilisation et sérologie anti-aspergillaire. Trente-quatre patients ont bénéficié d’une visite par un conseiller médical en environnement intérieur entre mars et août 2012, comprenant des prélèvements à visée mycologique. Le nombre de colonies aspergillaires ne différait pas significativement d’un site de prélèvement à l’autre (p = 0,251), mais le nombre de colonies non aspergillaires était significativement plus important dans la cuisine (p = 0,0045). L’exposition fongique domiciliaire a ensuite été comparée entre les groupes « marqueurs aspergillaires absents » et « marqueurs aspergillaires présents ». L’exposition domiciliaire à une flore aspergillaire (p = 0,453) et non aspergillaire (p = 0,972) ne différait pas significativement entre les 2 groupes. Sur cette série de 34 patients qui mérite d’être élargie, on note une absence de lien évident entre l’exposition domiciliaire et la pathologie aspergillaire. Ce résultat doit rendre prudent sur des conseils d’hygiène parfois très contraignants donnés aux familles, l’exposition fongique étant également importante dans le cadre des activités extra-domiciliaires.
ISSN: 1156-5233

hal-01158660
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01158660/file/Exposition%20domiciliaire%20aux%20moisissures%20postprint%20MYCMED-S-14-00173.pdf
DOI : 10.1016/j.mycmed.2015.03.005

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
STUDY QUESTION: Is there evidence at the population level of associations between different male genital disorders, outside Scandinavian countries? SUMMARY ANSWER: At an international scale, there is evidence for a number of correlations between rates of four male reproductive disorders (hypospadias, cryptorchidism, testicular cancer and low sperm concentration). WHAT IS KNOWN ALREADY: Some associations between these outcomes have been shown in studies focusing on individuals and mainly in Nordic European countries. These associations, together with histological evidence of a dysgenesis pattern in testicular tissue specimens, have generated the concept of the existence of a 'testicular dysgenesis syndrome' originating in utero. STUDY DESIGN, SIZE, DURATION: This is a geographical correlation study using cancer, malformations rates and sperm quality data collected between the years 1998 and 2005. PARTICIPANTS/MATERIALS, SETTING, METHODS: Incidence rates of testicular cancer were extracted from International Agency for Research on Cancer registries and Globocan, while cryptorchidism and hypospadias prevalence rates were obtained from EUROCAT and International Clearinghouse for Birth Defects Surveillance and Research registries. Sperm concentration data were extracted from recent studies using standardized methodology. A total of 39 registries and 9 sperm studies were selected. Non-parametric Spearman correlation tests were used to test the association between these four disorders. Correlations were computed for all registries together, for registries with high-quality matching coverage only and by continents. Sensitivity analyses were also conducted using data from prospective clinical studies to take into account potential bias related mainly to ascertainment of malformation rates. MAIN RESULTS AND THE ROLE OF CHANCE: We found positive correlations between testicular cancer and hypospadias (r = 0.32, P = 0.05) and between hypospadias and cryptorchidism (r = 0.70, P = 0.008). Stronger correlations were observed when using registries with high-quality matching coverage. Among these registries, differences between Europe and the rest of the world appeared (the positive correlation between testicular cancer and cryptorchidism was stronger outside Europe, r = 0.83, P = 0.01 compared with 0.40, P = 0.60 for European registries). A negative correlation between testicular cancer and sperm concentration was observed (r = -0.88, P = 0.002). These correlations support our initial hypothesis but remain only suggestive due to the intrinsic limitations in the study design (i.e. geographical correlation study) and do not allow causal inference. LIMITATIONS, REASONS FOR CAUTION: Differences in the ascertainment of malformations rates (definition, length of follow-up) make the international comparison difficult. The small number of registries for some conditions (cryptorchidism) or of studies (for sperm quality) and the absence of information about major risk factors such as ethnicity and socioeconomic status in the registries are also limitations. WIDER IMPLICATIONS OF THE FINDINGS: Our findings are in agreement with results of studies focusing on individuals and suggest that shared risk factors are present in the populations studied.
ISSN: 0268-1161

inserm-00863412
http://www.hal.inserm.fr/inserm-00863412
DOI : 10.1093/humrep/det111
PUBMED : 23670171

Éditeur(s) : HAL CCSD PeerJ
Résumé : International audience
The adaptative bleaching hypothesis (ABH) states that, depending on the symbiotic flexibility of coral hosts (i.e., the ability of corals to ''switch'' or ''shuffle'' their algal symbionts), coral bleaching can lead to a change in the composition of their associated Symbiodinium community and, thus, contribute to the coral's overall survival. In order to determine the flexibility of corals, molecular tools are required to provide accurate species delineations and to detect low levels of coral-associated Symbiodinium. Here, we used highly sensitive quantitative (real-time) PCR (qPCR) technology to analyse five common coral species from Moorea (French Polynesia), previously screened using only traditional molecular methods, to assess the presence of low-abundance (background) Symbiodinium spp. Similar to other studies, each coral species exhibited a strong specificity to a particular clade, irrespective of the environment. In addition, however, each of the five species harboured at least one additional Symbiodinium clade, among clades A–D, at background levels. Unexpectedly, and for the first time in French Polynesia, clade B was detected as a coral symbiont. These results increase the number of known coral-Symbiodinium associations from corals found in French Polynesia, and likely indicate an underestimation of the ability of the corals in this region to associate with and/or ''shuffle'' different Symbiodinium clades. Altogether our data suggest that corals from French Polynesia may favor a trade-off between optimizing symbioses with a specific Symbiodinium clade(s), maintaining associations with particular background clades that may play a role in the ability of corals to respond to environmental change. How to cite this article Rouzé et al. (2017), An updated assessment of Symbiodinium spp. that associate with common scleractinian corals from Moorea (French Polynesia) reveals high diversity among background symbionts and a novel finding of clade B.
ISSN: 2167-8359

Droits : info:eu-repo/semantics/OpenAccess
hal-01430294
https://hal-sde.archives-ouvertes.fr/hal-01430294
https://hal-sde.archives-ouvertes.fr/hal-01430294/document
https://hal-sde.archives-ouvertes.fr/hal-01430294/file/Rouze-2017-PeerJ-Updated.pdf
DOI : 10.7717/peerj.2856

Éditeur(s) : HAL CCSD IOP Publishing
Résumé : The use of electron probe microanalysis (EPMA) at low voltage allows improvements in the lateral resolution and surface sensitivity of the technique down to the sub-micrometre scale, and it is also useful in minimizing X-ray absorption (for the analysis of ultra-light elements), charging effects and secondary fluorescence. However, EPMA at low voltage is accompanied by a number of problems which may affect the accuracy of quantitative results. A large number of these problems arise from the need of using low-energy X-ray lines such as L- and M-lines, which have low fluorescence yields, large uncertainties in the mass attenuation coefficients, and are affected by several spectroscopic difficulties (e.g., peak shifts and overlaps). Other factors that play an important role at low voltage are carbon contamination, surface oxidation, the quality of sample polishing, the influence of a conductive coating and the limitations of matrix correction procedures. In this paper, we illustrate the capabilities of EPMA at low voltage and we examine in detail the different sources of uncertainty that may affect the accuracy of quantitative results.
ISSN: 1757-8981

hal-00767564
https://hal.archives-ouvertes.fr/hal-00767564
DOI : 10.1088/1757-899X/32/1/012016

Éditeur(s) : HAL CCSD Botanical Society of America
Résumé :  
Tree buckling risk (actual height/critical buckling height) is an important biomechanical trait of plant growth strategies, and one that contributes to species coexistence. To estimate the diversity of this trait among wide samples, a method that minimizes damage to the plants is necessary. On the basis of the rarely used, complete version of Greenhill's model (1881, Proceedings of the Cambridge Philosophical Society 4(2): 65-73), we precisely measured all the necessary parameters on a sample of 236 saplings of 16 species. Then, using sensitivity (variance) analysis, regressions between successive models for risk factors and species ranks and the use of these models on samples of self- and nonself-supporting saplings, we tested different degrees of simplification up to the most simple and widely used formula that assumes that the tree is a cylindrical homogeneous pole. The size factor had the greatest effect on buckling risk, followed by the form factor and the modulus of elasticity of the wood. Therefore, estimates of buckling risk must consider not only the wood properties but especially the form factor. Finally, we proposed a simple but accurate method of assessing tree buckling risk that is applicable to a wide range of samples and that requires mostly nondestructive measurements.
ISSN: 0002-9122

hal-01032059
https://hal.archives-ouvertes.fr/hal-01032059

Éditeur(s) : HAL CCSD
Résumé : International audience
In many geological reservoirs, open fractures or fault zones generally induce high spatial variability of hydrodynamical properties and shape the main deep-seated flow paths. It is of crucial interest to determine their structure and properties in order to achieve a sound and sustained exploitation of resources or to estimate the risk of failure of any underground storage. Tiltmeters have emerged as new tools to observe deformation generated by groundwater flow. As such instruments are highly sensitive to pressure gradients, they are perfectly suited for monitoring channelized flow in connected fractures and fault zones. Hence, they provide a unique insight of these reservoirs' geometry and dynamics over broad time scales. Here we demonstrate that continuous tilt data from surface long baseline tiltmeters (LBT) can be used alone to evaluate the general functioning of a fractured hardrock system and estimate the hydraulic properties of its main conductive features. The study is applied to the pumping site of Ploemeur observatory (Brittany, France) which is well documented and instrumented, and therefore forms a convenient setting for introducing LBT as tools for fractured media hydrology. On the short term, tilt signals are strongly correlated with pumping cycles and associated head level changes in well-connected boreholes. Besides, when pumps are stopped the maximal tilt direction is systematically perpendicular to a subvertical fault zone whose azimuth of strike has thereby been refined down to degree precision. By using a semi-analytical model of deformation, we establish the link between tilt and pressure change during pumping interruptions which then allows for hydraulic properties estimation from tilt measurements only. Finally, we validate our results with previous estimates obtained from other studies and discuss the orientation of future work that could enhance these estimates.
AGU Fall Meeting 2014
San Francisco, United States

insu-01093437
https://hal-insu.archives-ouvertes.fr/insu-01093437