Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
We report structural evidence of ductile strain localization in mantle pyroxenite from the spinel to plagioclase websterite transition in the Ronda Peridotite (southern Spain). Mapping shows that, in this domain, small-scale shear zones occurring at the base of the lithospheric section are systematically located within thin pyroxenite layers, suggesting that the pyroxenite was locally weaker than the host peridotite. Strain localization is associated with a sudden decrease of grain size and increasing volume fractions of plagioclase and amphibole as a result of a spinel to plagioclase phase transformation reaction during decompression. This reaction also fostered hydrogen extraction ('dehydroxylation') from clinopyroxene producing effective fluid saturation that catalyzed the synkinematic net-transfer reaction. This reaction produced fine-grained olivine and plagioclase, allowing the onset of grain-size sensitive creep and further strain localization in these pyroxenite bands. The strain localization in the pyroxenites is thus explained by their more fertile composition, which allowed earlier onset of the phase transition reactions. Geothermobarometry undertaken on compositionally zoned constituent minerals suggests that this positive feedback between reactions and deformation is associated with cooling from at least 1000°C to 700°C and decompression from 1*0 to 0*5 GPa.
ISSN: 0022-3530

hal-00941293
https://hal.archives-ouvertes.fr/hal-00941293
DOI : 10.1093/petrology/egt039

Résumé : The maritime economy includes the activities linked to the sea, namely: - Marine resource extraction: living resources and marine minerals, - Exploitation of marine space and of physical properties of marine waters (energy plants - using marine water as a heat sink, marine renewable energies, submarine cable laying, - maritime and coastal construction and public works, maritime transport, Navy), - Exploitation of seascapes (tourism, leisure, boating), - Resource processing (of living resources and oil & gas) - Manufacturing and service industries supplying the above exploitation activities: shipbuilding, ship repair and boat building and their suppliers, oil and gas services, financial services, - Public services: defence; State intervention at sea and public services to maritime activities and to seafarers; public and private activities contributing to the protection of marine and coastal environment; and public research. Since 1997, the French Marine Economic Data report, published by Ifremer, includes a set of key sectoral indicators used to value the economic significance of the French marine-related activities in terms of production and jobs, their role in the national economy, their weight in international competition and the importance of non-market public services. The analysis of the marine sectors is carried out mainly at national scale but regional indicators are also presented when they are available. The European dimension of the activities is also taken into account.

Droits : 2014 Ifremer
http://archimer.ifremer.fr/doc/00253/36455/34990.pdf
DOI:10.13155/36455
http://archimer.ifremer.fr/doc/00253/36455/

Éditeur(s) : HAL CCSD Wiley
Résumé : Seasonal variations in environmental conditions influence the functioning of the whole ecosystem of tropical rain forests, but as yet little is known about how such variations directly influence the leaf gas exchange and transpiration of individual canopy tree species. We examined the influence of seasonal variations in relative extractable water in the upper soil layers on predawn leaf water potential, saturated net photosynthesis, leaf dark respiration, stomatal conductance, and tree transpiration of 13 tropical rain forest canopy trees (eight species) over 2yr in French Guiana. The canopies were accessed by climbing ropes attached to the trees and to a tower. Our results indicate that a small proportion of the studied trees were unaffected by soil water depletion during seasonal dry periods, probably thanks to efficient deep root systems. The trees showing decreased tree water status (i.e., predawn leaf water potential) displayed a wide range of leaf gas exchange responses. Some trees strongly regulated photosynthesis and transpiration when relative extractable water decreased drastically. In contrast, other trees showed little variation, thus indicating good adaptation to soil drought conditions. These results have important applications to modeling approaches: indeed, precise evaluation and grouping of these response patterns are required before any tree-based functional models can efficiently describe the response of tropical rain forest ecosystems to future changes in environmental conditions.
ISSN: 0006-3606

hal-01032411
https://hal.archives-ouvertes.fr/hal-01032411
DOI : 10.1111/j.1744-7429.2012.00902.x

Éditeur(s) : HAL CCSD
Résumé : International audience
The authors analyze the data concerning 219 sera, that they have tested in passive hemagglutination, with as antigen a Dirofilaria immitis proteic extract, in French Polynesia. Besides its light sensitivity, this method does appear very interesting. It points out: --First, that there is a gaussian distribution of the results found at various dilutions, both by "filarian" and "non filarian" people. Therefore, this distribution is a feasible and practical parameter for evaluation of the Filariasis transmission in different populations. --On the other hand, that there is an inverse correlation between the presence of microfilaria in the blood and the level of immunological response for lymphatic Filariasis.
Bull Soc Pathol Exot Filiales

hal-00715412
https://hal.univ-antilles.fr/hal-00715412
PUBMED : 1037386

Éditeur(s) : HAL CCSD Hermann-Éditions
Résumé : International audience
Dans le domaine des réseaux sociaux, la recherche de motifs fréquents correspond à l'extraction de sous-graphes retrouvés fréquemment dans un réseau ou un ensemble de réseaux. Contrairement aux approches classiques qui s'appuient uniquement sur des régularités structurelles, nous présentons dans ce travail l'outil GT-FLMin, capable d'exploiter les informations sur la structure pour extraire des régularités dans les liens qui connectent des noeuds similaires du point de vue de leurs caractéristiques. Nous appelons de tels motifs des liens fréquents.
Extraction et gestion des connaissances
Bordeaux, France

hal-00768426
https://hal.archives-ouvertes.fr/hal-00768426

Éditeur(s) : HAL CCSD
Résumé : International audience
Handwriting difficulties represent a common cause of underachievement in children education and low self-esteem in daily life. The analysis of handwriting could be an important tool for the evaluation of a teaching method in order to assess its efficacy in preventing dysgraphia. We performed a comparative analysis of the traditional handwriting method and the alternative Terzi's approach in pupils at the end of primary school, when cursive skills should have been achieved.Qualitative and kinematic parameters were considered: the first ones were calculated as a visual analysis of written texts (by using check-lists and scales regarding qualitative, postural and pen grasp aspects), while the latter ones were automatically extracted through digitizing tablet acquisitions. Results showed significant differences concerning handwriting quality and dynamic movement in pupils handwriting depending on the teaching method applied.
17th Biennial Conference of the International Graphonomics Society
Pointe-à-Pitre, Guadeloupe

hal-01165776
https://hal.univ-antilles.fr/hal-01165776
https://hal.univ-antilles.fr/hal-01165776/document
https://hal.univ-antilles.fr/hal-01165776/file/IGS_2015_submission_10.pdf

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cet article se réfère à ce que certains auteurs nomment, au Brésil, «nouveaux territoires» qui, depuis les débats lors de la Constituante fédérale de 1988, ont pris place, totalement ou partiellement, dans les circonscriptions tels qu’un État, une Commune, un District. Ce texte aborde deux types de réserves de conservation environnementale: une « réserve extractiviste » conquise par des populations rurales riveraines au confluent des fleuves Xingu et Amazone; et une « réserve marine» de populations rurales côtières – les deux à l’État du Pará. Au Brésil comme en Europe, ces initiatives ont visé un meilleur mode de vie et le développement des populations locales et, éventuellement, par surplus, régionales ou nationales. Au Brésil, ces objectifs ont été liés au droit à l’usage collectif des forêts, des bois, des cours d’eau et des mangroves. À des degrés différents, ces territoires sont issus de luttes pour la défense des ressources qui étaient la source de la subsistance de leurs habitants, de leur mode de vie et culture, en un mot, leur patrimoine – contre la pénétration d’« étrangers » venus d’ailleurs en dépit de la loi et de la légitimité: entreprises du bois, de grands élevages et de pêche. Ce texte cherche à confronter, au niveau de l’analyse sociologique, des intérêts de groupes, des acteurs, des stratégies des uns et des autres et de leurs perspectives pour les actuelles et futures générations.
This article refers to what some writers call, in Brazil, "new territories". Since the debates during the Federal Constitution elaboration, in 1988, they have been implemented, wholly or partly, within the jurisdiction of a state, a municipality, or a district. This paper addresses two types of environmental conservation reserves: an "extractive reserve" conquered by rural people at the confluence of the rivers Xingu and Amazon; and a "marine reserve" of rural populations on the northern coast of Brazil - both in the federal state of Pará. In Brazil as in Europe, these initiatives aim at better living standards and collective development of local populations. In Brazil, these have been linked to the respect of their collective rights to use the forests, wood, water streams and mangroves. To varying degrees, these territories result from struggles in defense of natural resources that were source of livelihood, lifestyle and culture of the inhabitants, in short, their heritage – against the invasion of "foreigners", timber companies, large farms and fishers. This text contrasts, through sociological analysis, the interest groups, the stakeholders, the challenges and their development prospects vis-à-vis the present and future generations.
Brésil

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.8854
http://journals.openedition.org/etudescaribeennes/8854

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : Climate models for the coming century predict rainfall reduction in the Amazonian region, including change in water availability for tropical rainforests. Here, we test the extent to which climate variables related to water regime, temperature and irradiance shape the growth trajectories of neotropical trees. . We developed a diameter growth model explicitly designed to work with asynchronous climate and growth data. Growth trajectories of 205 individual trees from 54 neotropical species censused every 2 months over a 4-year period were used to rank 9 climate variables and find the best predictive model. . About 9% of the individual variation in tree growth was imputable to the seasonal variation of climate. Relative extractable water was the main predictor and alone explained more than 60% of the climate effect on tree growth, i.e. 5.4% of the individual variation in tree growth. Furthermore, the global annual tree growth was more dependent on the diameter increment at the onset of the rain season than on the duration of dry season. . The best predictive model included 3 climate variables: relative extractable water, minimum temperature and irradiance. The root mean squared error of prediction (0.035 mm.d(-1)) was slightly above the mean value of the growth (0.026 mm.d(-1)). . Amongst climate variables, we highlight the predominant role of water availability in determining seasonal variation in tree growth of neotropical forest trees and the need to include these relationships in forest simulators to test, in silico, the impact of different climate scenarios on the future dynamics of the rainforest.
ISSN: 1932-6203

hal-01268350
https://hal.archives-ouvertes.fr/hal-01268350
DOI : 10.1371/journal.pone.0034074
PRODINRA : 215438
PUBMED : 22506012

Éditeur(s) : HAL CCSD
Résumé : International audience
We instrumented a car simulator by gathering low level data and fed it to an artificial neural network in order to perform blood alcohol content (BAC) estimations. The results depend on the quality of the data extraction and processing, and also on the selected inputs. We explain our data extraction and processing methodology, and how we used it to generate reliable and comparable features. At last, we describe the performances of individual features and how they combine. In the end, the prototype was able to accurately estimate the BAC value of a subject after being trained with driving samples of this subject with various BAC values.
Proceedings of ACHI 2013, The Sixth International Conference on Advances in Computer-Human Interactions
Nice, France

hal-00850137
https://hal.archives-ouvertes.fr/hal-00850137

Éditeur(s) : HAL CCSD
Résumé : International audience
Symbiosis is a widespread phenomenon in the biosphere. In marine benthic environments breakdown of symbiosis is responsible for coral bleaching and dramatically affects coral reef ecosystems functioning [1]. In the water column, planktonic organisms are key component of pelagic ecosystems and a number of species form mutualistic association with microalgae forming a photosymbiosis [2]. Here we intended to investigate the genetic basis of photosymbiosis, through a transcriptomic approach on marine plankton organisms. We focused more specifically on associations occurring between radiolarian host (protist, zooplankton) and dinoflagellates symbiont (protist, phytoplankton) living inside the host cell. It has recently been highlighted that these holobionts are widespread in oligotrophic open oceans and there are also evidences of their fundamental implication in biogeochemical carbon, silica and strontium cycles [3, 4, 5, 6]. RNA-seq technologies allow obtaining an unprecedented amount of data for unicellular organisms isolated from the environment [7]. The study of such non-model holobionts datasets requires de novo assembly, which implies considerable computational resources and the potential production of chimeric sequences [8, 9].We therefore developed an original strategy aiming at accelerating and improving de novo assembly for holobiont datasets. We chose SIMKA [10] a fast kmer-based method initially developed to estimate the similarity between numerous metagenomic datasets, and which has been recently adapted to extract their common sequences. As our symbionts are identified, we used SIMKA to compare our holobionts transcriptomes to publicly available dinoflagellates transcriptomes [11] generating two datasets, one composed of reads from the symbionts and another with reads from the host (for which no reference data are currently available). Independent assemblies were then performed in parallel, accelerating the study process, and minimizing the proportion of resulting chimeric sequences. Our strategy produced a unique and comprehensive genomic dataset for Radiolaria [12, 13], and offers a pragmatic, large scale, comparison strategy to assemble and study holobionts [9]. Our new sequences obtained from holobionts study will be used for phylogenomics investigation, as reference for environmental metagenomic studies and ultimately to understand and characterize the molecular basis of symbiotic relationships in the plankton.Bibliografic references :[1] Simon K. Davy, Denis Allemand, and Virginia M. Weis. “Cell Biology of Cnidarian-Dinoflagellate Symbiosis”. In: Microbiology and Molecular Biology Reviews 76.2 (June 1, 2012), pp. 229–261. issn: 1092-2172, 1098- 5557. doi: 10.1128/MMBR.05014-11.[2] Janouškovec, J. et al. “Major transitions in dinoflagellate evolution unveiled by phylotranscriptomics”. in: PNAS 201614842 (2016). doi:10.1073/pnas.1614842114[3] Tristan Biard et al. “In situ imaging reveals the biomass of giant protists in the global ocean”. In: Nature advance online publication (Apr. 20, 2016). issn: 0028-0836. doi: 10.1038/nature17652.[4] Lionel Guidi et al. “Plankton networks driving carbon export in the olig- otrophic ocean”. In: Nature 532.7600 (Apr. 28, 2016), pp. 465–470. issn: 0028-0836. doi: 10.1038/nature16942.[5] Diane K. Stoecker et al. “Acquired phototrophy in aquatic protists”. In: Aquatic Microbial Ecology 57.3 (Nov. 24, 2009), pp. 279–310. doi: 10.3354/ame01340.[6] Johan Decelle et al. “An original mode of symbiosis in open ocean plankton”. In: Proceedings of the National Academy of Sciences 109.44 (Oct. 30, 2012), pp. 18000–18005. issn: 0027-8424, 1091-6490. doi: 10. 1073/pnas.1212303109.[7] Sergio Balzano et al. “Transcriptome analyses to investigate symbiotic relationships between marine protists”. In: Frontiers in Microbiology 6 (Mar. 17, 2015). issn: 1664-302X. doi: 10.3389/fmicb.2015.00098.[8] Li, B. et al. “Evaluation of de novo transcriptome assemblies from RNA-Seq data”. In: Genome Biology 15, 553 (2014).[9] Sangwan, N., Xia, F. & Gilbert, J. A. “Recovering complete and draft population genomes from metagenome datasets”. In: Microbiome 4, 8 (2016).[10] Gaëtan Benoit et al. “Multiple comparative metagenomics using mul- tiset k -mer counting”. In: PeerJ Computer Science 2 (Nov. 14, 2016). doi: 10.7717/peerj-cs.94.[11] Patrick J. Keeling et al. “The Marine Microbial Eukaryote Transcriptome Sequencing Project (MMETSP): Illuminating the Functional Diversity of Eukaryotic Life in the Oceans through Transcriptome Sequencing”. In: PLOS Biol 12.6 (June 2014), e1001889. issn: 1545-7885. doi: 10.1371/journal.pbio.1001889.[12] Burki, F. et al. “Evolution of Rhizaria: new insights from phylogenomic analysis of uncultured protists”. In BMC Evolutionary Biology 10, 377 (2010).
International Conference on Holobionts
Paris, France

hal-01575069
https://hal.inria.fr/hal-01575069

Éditeur(s) : HAL CCSD
Résumé : The use of Xylopia frutescens extract as a C38 steel corrosion inhibitor in 1 M HCl solution was investigated by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) methods. Potentiodynamic polarization curves indicated that Xylopia frutescens extract behaves as mixed-type inhibitor. Graphical methods are illustrated by synthetic data to determine the parameter of CPE (α, Q). The adsorption of the extract constituents was further discussed in view of Langmuir adsorption isotherm. The effect of temperature on the inhibition efficiency was investigated using EIS and potentiodynamic polarization. SEM and EDX observations confirmed the existence of protective inhibitor film on metal surface.
ISSN: 1938-6737

hal-01304527
https://hal.archives-ouvertes.fr/hal-01304527
DOI : 10.1149/06426.0001ecst
PRODINRA : 351608

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Three soil DNA extraction procedures (homemade protocols and commercial kit) varying in their practicability were applied to contrasting soils to evaluate their efficiency in recovering: (i) soil DNA and (ii) bacterial diversity estimated by 16S rDNA pyrosequencing. Significant differences in DNA yield were systematically observed between tested procedures. For certain soils, 10 times more DNA was recovered with one protocol than with the others. About 15 000 sequences of 16S rDNA were obtained for each sample which were clustered to draw rarefaction curves. These curves, as well as the PCA ordination of community composition based on OTU clustering, did not reveal any significant difference between procedures. Nevertheless, significant differences between procedures were highlighted by the taxonomic identification of sequences obtained at the phylum to genus levels. Depending on the soil, differences in the number of genera detected ranged from 1% to 26% between the most and least efficient procedures, mainly due to a poorer capacity to recover populations belonging to Actinobacteria, Firmicutes or Crenarchaeota. This study enabled us to rank the relative efficiencies of protocols for their recovery of soil molecular microbial biomass and bacterial diversity and to help choosing an appropriate soil DNA extraction procedure adapted to novel sequencing technologies.
ISSN: 1751-7915

hal-01546177
https://hal.archives-ouvertes.fr/hal-01546177
DOI : 10.1111/j.1751-7915.2011.00307.x

Éditeur(s) : HAL CCSD IEEE
Résumé : International audience
In this paper, we present an evolutionary approach for extracting a model of flood prediction from hydrological data observed timely on water heights in a river watershed. Since this kind of data recorded by sensors on river basins is highly scarce and hopefully much unbalanced between cases of floods and non-floods, we have adopted the notion of aggregate variables which values are computed as aggregates on raw data. An evolutionary algorithm is involved to allow selecting the best sets - juries of classifiers- of such variables as predictive variables. Two real hydrological data sets are trained and they both show the efficiency of the method compared to traditional solutions for prediction.
IEEE Congress on Evolutionary Computation 2012
Brisbane, Australia

hal-00840739
https://hal.archives-ouvertes.fr/hal-00840739
DOI : 10.1109/CEC.2012.6252897

Éditeur(s) : HAL CCSD
Résumé : International audience
More and more animal species are endangered. In order to study and protect them, several measures have been taken, which now seem to show their limit. This work focuses on the counting process, a key issue for any project that aims to protect animals. Indeed, this paper proposes an algorithm for automatic counting of singing birds in their habitat by using wireless sensors fitted with microphone. Sensors are used to record audio samples of bird songs. These samples are used to extract some kinds of song fingerprint that are thereafter used to recognize the bird species, through a classification process. Afterwards, by analyzing data which have been collected by a central base, the network structure derived from detection fields of sensors, allows our algorithm to propose an estimate of singing birds in the habitat. This paper details the counting algorithm which uses graph theory and audio inputs comparison. Finally, we demonstrate our scheme efficiency through experimentations.
Local Computer Networks (LCN)
Clearwater, United States

hal-00786165
https://hal.archives-ouvertes.fr/hal-00786165
DOI : 10.1109/LCNW.2012.6424060

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Grain deviations and high extractives content are common features of many tropical woods. We aimed at clarifying their respective impact on vibrational properties, referring to African Padauk (Pterocarpus soyauxii Taub.), a species selected for its interlocked grain, high extractives content, and uses in xylophones. Specimens were cut parallel to the trunk axis (L), and local variations in grain angle (GA), microfibril angle (MFA), specific Young's modulus (E'L/ρ, where r stands for specific gravity) and damping coefficient (tanδL), were measured. GA dependence was analyzed by a mechanical model which allowed to identify the specific Young's modulus (E'3/ρ) and shear modulus (G'/ρ) along the grain (3), as well as their corresponding damping coefficients (tanδ3, tanδG). This analysis was done for native and then for extracted wood. Interlocked grain resulted in 0-25° GA and in variations of a factor 2 in E'L/ρ and tanδL. Along the grain, Padauk wood was characterized, as compared to typical hardwoods, by a somewhat lower E'3/ρ and elastic anisotropy (E'/G'), due to a wide microfibril angle plus a small weight effect of extracts; and a very low tanδ3 and moderate damping anisotropy (tanδG/tanδ3). Extraction affected mechanical parameters in the order: tanδ3 ≈ tanδG > G'/ρ >> E'3/ρ. That is, extractives' effects were nearly isotropic on damping but clearly anisotropic on storage moduli.
ISSN: 0043-7719

hal-00544382
https://hal.archives-ouvertes.fr/hal-00544382
https://hal.archives-ouvertes.fr/hal-00544382/document
https://hal.archives-ouvertes.fr/hal-00544382/file/Identification_anisotropic_vibrational_properties_Bremaud_al.pdf
DOI : 10.1007/s00226-010-0348-0

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : Though the root biomass of tropical rainforest trees is concentrated in the upper soil layers, soil water uptake by deep roots has been shown to contribute to tree transpiration. A precise evaluation of the relationship between tree dimensions and depth of water uptake would be useful in tree-based modelling approaches designed to anticipate the response of tropical rainforest ecosystems to future changes in environmental conditions. We used an innovative dual-isotope labelling approach (deuterium in surface soil and oxygen at 120-cm depth) coupled with a modelling approach to investigate the role of tree dimensions in soil water uptake in a tropical rainforest exposed to seasonal drought. We studied 65 trees of varying diameter and height and with a wide range of predawn leaf water potential (I-pd) values. We confirmed that about half of the studied trees relied on soil water below 100-cm depth during dry periods. I-pd was negatively correlated with depth of water extraction and can be taken as a rough proxy of this depth. Some trees showed considerable plasticity in their depth of water uptake, exhibiting an efficient adaptive strategy for water and nutrient resource acquisition. We did not find a strong relationship between tree dimensions and depth of water uptake. While tall trees preferentially extract water from layers below 100-cm depth, shorter trees show broad variations in mean depth of water uptake. This precludes the use of tree dimensions to parameterize functional models.
ISSN: 0029-8549

hal-01032433
https://hal.archives-ouvertes.fr/hal-01032433
DOI : 10.1007/s00442-013-2724-6

Éditeur(s) : Public Library Science
Résumé : The European Union and other states are moving towards Ecosystem Based Fisheries Management to balance food production and security with wider ecosystem concerns. Fishing is only one of several sectors operating within the ocean environment, competing for renewable and non-renewable resources that overlap in a limited space. Other sectors include marine mining, energy generation, recreation, transport and conservation. Trade-offs of these competing sectors are already part of the process but attempts to detail how the seas are being utilised have been primarily based on compilations of data on human activity at large spatial scales. Advances including satellite and shipping automatic tracking enable investigation of factors influencing fishers' choice of fishing grounds at spatial scales relevant to decision-making, including the presence or avoidance of activities by other sectors. We analyse the determinants of English and Welsh scallop-dredging fleet behaviour, including competing sectors, operating in the eastern English Channel. Results indicate aggregate mining activity, maritime traffic, increased fishing costs, and the English inshore 6 and French 12 nautical mile limits negatively impact fishers' likelihood of fishing in otherwise suitable areas. Past success, net-benefits and fishing within the 12 NM predispose fishers to use areas. Systematic conservation planning has yet to be widely applied in marine systems, and the dynamics of spatial overlap of fishing with other activities have not been studied at scales relevant to fisher decision-making. This study demonstrates fisher decision-making is indeed affected by the real-time presence of other sectors in an area, and therefore trade-offs which need to be accounted for in marine planning. As marine resource extraction demands intensify, governments will need to take a more proactive approach to resolving these trade-offs, and studies such as this will be required as the evidential foundation for future seascape planning.
Plos One (1932-6203) (Public Library Science), 2015-01-27 , Vol. 10 , N. 1 , P. 1-14

Droits : 2015 Tidd et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
http://archimer.ifremer.fr/doc/00254/36518/35064.pdf
DOI:10.1371/journal.pone.0116335
http://archimer.ifremer.fr/doc/00254/36518/

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 Wiley-VCH Verlag
Résumé : International audience
Saccharopolyspora rectivirgula is the principal cause of farmer's lung disease (FLD). Serodiagnosis is based on immunoprecipitation techniques or enzyme immunoassays with homemade crude antigens and is not standardized. We aimed to produce specific recombinant antigens for the development of a standardized ELISA. We recruited 41 patients and 43 healthy exposed controls from five university hospital pneumology departments in France and Switzerland. S. rectivirgula proteins were extracted, separated by 2D electrophoresis, and subjected to Western blotting, with sera from FLD patients or controls. FLD-specific proteins were identified by MS and were produced as recombinant antigens. The diagnostic performance of ELISA tests using the recombinant antigens was assessed with all the sera from FLD patients and controls. We identified 25 FLD-specific proteins, some of which play important roles in transport, nutrition, or virulence. We produced 17 of these proteins as recombinant antigens and assessed their suitability for inclusion in the ELISA test. A combination of three of these proteins (SR1FA, SR17, and SR22) proved remarkably effective at discriminating between patients and controls, with a sensitivity of 83% and a specificity of 77%. The recombinant antigens produced in this study constitute a major step toward the improvement of diagnostic performance and the standardization of FLD serodiagnosis.
ISSN: 1862-8346

hal-01115880
https://hal.archives-ouvertes.fr/hal-01115880
DOI : 10.1002/prca.201400024
PUBMED : 25264606

Résumé : En raison de la nature symbiotique des micro-organismes endophytes, cette étude visait à étudier l'activité antibactérienne, antifongique et cytotoxique chez les métabolites secondaires des extraits endophytes foliaires de plantes de l'Amazonie brésilienne et du Cerrado. Dans ce travail de thèse 147 micro-organismes cultivables ont été isolés (130 champignons, 3 bactéries e 14 champignons non-identifiés ou inconnus) à partir de 28 plantes (4 espèces collectées au Brésil et 24 en Guyane Française). Tous les micro-organismes furent identifiés par analyse moléculaire des régions spécifiques de l'ADNr en utilisant des techniques de séquençage génomique. Des champignons endophytes de l’ordre des Xylariales furent ceux de plus importante fréquence d’isolation dans cette étude, représentés par 25 isolats. Des extraits bruts à l’AcOEt furent produits à partir de cultures de chaque micro-organisme isolé. Une proportion relative signifiante (23,1%) des extraits démontra une activité sur Candida albicans ATCC 10213, pendant que 4% furent actifs sur Staphylococcus aureus ATCC 29213. Le potentiel cytotoxique des extraits fut évalué pour des lignées cellulaires humaines KB (carcinome cervical utérin), MDA-MB-435 (mélanome), et MRC-5 (fibroblastes de poumon normal), résultant en proportion signifiante avec activité d’inhibition de la prolifération cellulaire (24,4%, 23,1% e 16,3%, respectivement).Dix-huit métabolites secondaires furent isolés et identifiés à partir du fractionnement des extraits bruts de huit endophytes. Dix-sept de ces substances furent déjà décrites précédemment dans la littérature: l’acide piliformique (24) et la griséofulvine (25) isolés à partir de Xylaria cubensis SNB-GCI02; La phomopirone (26), la pyrenocine (27), l’alterpérilenol (28) et la novae-zelandine (29), isolés de Lewia infectoria SNB-GTC2402; 5-métilmelleina (31) et la dihidrosporothrioride (32) isolées à partir de Xylaria sp. SNB-GTC2501; La mycoleptodiscine (34) et la mycoleptodiscine B (35) isolées à partir de Mycoleptodiscus sp. SNB-GTC2304; le mycoepoxidiène (36) et la altiloxina A (37) isolés à partir de Diaporthe pseudomangiferae SNB-GSS10; L’acremonisol (40), le semicochliodinol (41) et le cochliodinol (42) isolés à partir de Chaetomium globosum SNB-GTC2114; la colletofragarone A2 (43) isolée à partir de Colletotrichum sp. SNB-GTC0201; la flavoglaucine (44) isolée à partir de Eurotium rubrum BBS01. Parmi ces substances, la flavoglaucine (44) isolée à partir de E. rubrum BBS01 démontra une activité comparable au contrôle fluconazol en C. albicans (CIM de 4 µg.mL-1). La substance (44) présenta IC50 >10 µM sur cellules normales MRC-5, ce qui en fait un candidat pour des études ultérieures. Dans ce travail, fut identifié pour la première fois l’activité de la colletofragarone A2 (43) isolée à partir de Colletotrichum sp. SNB-GTC0201. La substance inédite nommée pyrrocidine C (30) fut isolée à partir de L. infectoria SNB-GTC2402 et identifiée par des analyses spectroscopiques (Casella et al., 2013). La pyrrocidine C (30) fut active en S. aureus ATCC 10213 (CIM de 2 µg.mL-1) et ne fut pas considérées cytotoxique pour les cellules normales MRC-5 (IC50 >10 µM), démontrant une sélectivité dans l’action antimicrobienne. Ces résultats démontrent la grande diversité des endophytes fongiques chez les plantes de l'Amazonie brésilienne et du Cerrado et la grande chimiodiversité associée aux métabolites secondaires de ces micro-organismes. Des champignons endophytes tropicaux, comme ceux présentés dans cette étude, peuvent apparaître comme une nouvelle source de substances antimicrobiennes et cytotoxiques.
Because of the symbiotic nature of endophytes, this survey aims to investigate the probality of discovering antibacterial, antifungal and cytotoxic activities in secondary metabolites of leaf endophytes isolated from plants of Amazon and Cerrado biomes. In this study, 147 cultivable microorganisms were isolated (130 fungi, 3 bacteria and 14 unidentified or unknown microbes) from 28 plant species (4 species collected in Brazil and 24 in French Guyana). All endophytes were identified by molecular analyses of specific rDNA regions, with genomic sequencing techniques. Fungal endophytes belonging to Xylariales order were the most frequently isolated in this study, represented by 25 isolates. Crude AcOEt extracts were produced from cultures of each isolated endophyte. A significant relative proportion (23,1%) of extracts showed activity in Candida albicans ATCC 10213, while 4% were active in Staphylococcus aureus ATCC 29213. The cytotoxic potencial of the extracts was evaluated for human cell lines KB (uterin cervical carcinome), MDA-MB-435 (melanoma) and MRC-5 (normal lung fibroblasts), and a significant proportion of them showed cellular proliferation inhibition (24,4%, 23,1% e 16,3%, respectively).Eighteen secondary metabolites were isolated by the fractionation of eight endophytic extracts. Seventeen of these substances had already been previously described in the literature: piliformic acid (24) and griseofulvin (25) isolated from Xylaria cubensis SNB-GCI02; phomopiron A (26), pyrenocin A (27), alterperilenol (28) and novae-zelandin A (29) isolated from Lewia infectoria SNB-GTC2402; 5-metilmellein (31) and dihidrosporothriorid (32) isolated from Xylaria sp. SNB-GTC2501; mycoleptodiscin A (34) and mycoleptodiscin B (35) isolated from Mycoleptodiscus sp. SNB-GTC2304; mycoepoxidien (36) and altiloxin A (37) isolated from Diaporthe pseudomangiferae SNB-GSS10; acremonisol A (40), semicochliodinol A (41) and cochliodinol (42) isolated from Chaetomium globosum SNB-GTC2114; colletofragaron A2 (43) isolated from Colletotrichum sp. SNB-GTC0201; flavoglaucin (44) isolated from Eurotium rubrum BBS01. Among these substances, flavoglaucin (44), isolated from E. rubrum BBS01, showed comparable antifungal activity with the positive control fluconazol in C. albicans (MIC of 4 µg.mL-1). Flavoglaucin (44) also showed IC50 >10 µM in normal MRC-5 cells, becoming a good candidate for further studies. In this work, the cytotoxic activity of colletofragaron A2 (43), isolated from Colletotrichum sp. SNB-GTC0201 was described for the first time. The unpublished substance named pyrrocidin C (30) isolated from L. infectoria SNB-GTC2402 was identified by spectroscopic analyses (Casella et al., 2013). The pyrrocidin C (30) was active in S. aureus ATCC 10213 (MIC of 2 µg.mL-1), and was not considered cytotoxic for normal MRC-5 cells (IC50 >10 µM), showing selectivity in antimicrobial activity. These results demonstrate the great endophytic fungal diversity in plants of Amazon and Cerrado biomes, along with the chemodiversity associated to the secondary metabolites of these endophytes. Tropical fungal endophytes, like those seen in this work, may emerge as a new source of antimicrobial and cytotoxic substances.
Devido à natureza simbiótica dos micro-organismos endofíticos, este estudo teve como objetivo investigar a atividade antibacteriana, antifúngica e citotóxica em metabólitos secundários de extratos de fungos endofíticos foliares de plantas do bioma Amazônia e Cerrado. Neste trabalho de tese foram isolados 147 micro-organismos cultiváveis (130 fungos, 3 bactérias e 14 fungos não-identificados ou desconhecidos) a partir de 28 plantas (4 espécies coletadas no Brasil e 24 na Guiana Francesa). Todos os micro-organismos foram identificados por análise molecular de regiões específicas de DNAr, com uso de técnicas de sequenciamento genômico. Fungos endofíticos da ordem Xylariales foram os de maior frequência de isolamento neste estudo, representados por 25 isolados. Extratos brutos em AcOEt foram produzidos a partir de culturas de cada micro-organismo isolado. Uma proporção relativa significante (23,1%) dos extratos demonstrou atividade em Candida albicans ATCC 10213, enquanto 4% foram ativos em Staphylococcus aureus ATCC 29213. O potencial citotóxico dos extratos foi avaliado para as linhagens celulares humanas KB (carcinoma cervical uterino), MDA-MB-435 (melanoma), e MRC-5 (fibroblastos de pulmão normal), resultando em proporção significante com atividade de inibição da proliferação celular (24,4%, 23,1% e 16,3%, respectivamente). Dezoito metabólitos secundários foram isolados a partir do fracionamento de oito extratos brutos endofíticos. Dezessete destas substâncias já tinham sido descritas anteriormente na literatura: ácido pilifórmico (24) e griseofulvina (25) isoladas de Xylaria cubensis SNB-GCI02; phomopirona A (26), pyrenocina A (27), alterperilenol (28) e novae-zelandina A (29) isoladas de Lewia infectoria SNB-GTC2402; 5-metilmelleina (31) e Dihidrosporothriolida (32) isoladas de Xylaria sp. SNB-GTC2501; mycoleptodiscina A (34) e mycoleptodiscina B (35) isoladas de Mycoleptodiscus sp. SNB-GTC2304; mycoepoxidieno (36) e altiloxina A (37) isoladas de Diaporthe pseudomangiferae SNB-GSS10; acremonisol A (40), semicochliodinol A (41) e cochliodinol (42) isoladas de Chaetomium globosum SNB-GTC2114; colletofragarona A2 (43) isolada de Colletotrichum sp. SNB-GTC0201; flavoglaucina (44) isolada de Eurotium rubrum BBS01. Dentre estas substâncias, a flavoglaucina (44) isolada de E. rubrum BBS01, demonstrou atividade comparável ao controle fluconazol em C. albicans (CIM de 4 µg.mL-1). Esta substância (44) apresentou IC50 >10 µM em células normais MRC-5, tornando-se candidata para estudos posteriores. Neste trabalho foi identificado pela primeira vez a atividade citotóxica da colletofragarona A2 (43), isolada de Colletotrichum sp. SNB-GTC0201. A substância inédita nomeada pyrrocidina C (30) foi isolada a partir de L. infectoria SNB-GTC2402 e identificada através de análises espectroscópicas (Casella et al., 2013). A pyrrocidina C (30) foi ativa em S. aureus ATCC 10213 (CIM de 2 µg.mL-1), e não foi considerada citotóxica para as células normais MRC-5 (IC50 >10 µM), demonstrando seletividade na ação antimicrobiana. Estes resultados demonstram a grande diversidade fúngica endofítica em plantas do bioma Amazônia e Cerrado, e a quimiodiversidade associada aos metabólitos secundários destes micro-organismos. Fungos endofíticos tropicais, como os vistos neste trabalho, podem emergir como uma nova fonte de substâncias antimicrobianas e citotóxicas.

http://www.theses.fr/2014AGUY0836/document