Éditeur(s) : HAL CCSD European Geosciences Union
Résumé : International audience
The seasonal climate drivers of the carbon cycle in tropical forests remain poorly known, although these forests account for more carbon assimilation and storage than any other terrestrial ecosystem. Based on a unique combination of seasonal pan-tropical data sets from 89 experimental sites (68 include aboveground wood productivity measurements and 35 litter productivity measurements), their associated canopy photosynthetic capacity (enhanced vegetation index, EVI) and climate, we ask how carbon assimilation and aboveground allocation are related to climate seasonality in tropical forests and how they interact in the seasonal carbon cycle. We found that canopy photosynthetic capacity seasonality responds positively to precipitation when rainfall is < 2000 mm yr(-1) (water-limited forests) and to radiation otherwise (light-limited forests). On the other hand, independent of climate limitations, wood productivity and litterfall are driven by seasonal variation in precipitation and evapotranspiration, respectively. Consequently, light-limited forests present an asynchronism between canopy photosynthetic capacity and wood productivity. First-order control by precipitation likely indicates a decrease in tropical forest productivity in a drier climate in water-limited forest, and in current light-limited forest with future rainfall < 2000 mm yr(-1).
ISSN: 1726-4170

hal-01557759
https://hal.univ-lorraine.fr/hal-01557759
https://hal.univ-lorraine.fr/hal-01557759/document
https://hal.univ-lorraine.fr/hal-01557759/file/bg-13-2537-2016.pdf
DOI : 10.5194/bg-13-2537-2016

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
A new portable sampling system was developed to extract Radium isotopes from large volumes (up to 300 L) of fresh surface- and ground-waters of low Ra-activities (<5 mBq/L). Ra is quantitatively adsorbed on a small amount (6.5 g) of MnO2-coated acrylic fibers, which are then dried and burned at 600 °C in the laboratory. The resulting Mn-oxide powder (about 2 cm3 when compacted) is then analyzed through gamma-ray spectrometry which allows measurement of the whole Ra quartet (226Ra, 228Ra, 224Ra and 223Ra) in a single counting of a few days. The usual relative standard combined uncertainties (1σ) are 2–3% for 226Ra, 228Ra and 224Ra; and less than 10% for 223Ra. This method was applied to the analysis of Ra in karstic waters of the Lez aquifer, and surface- and ground-waters of the upper and middle Vidourle watershed (South of France). The analyzed waters have relatively low 226Ra activities (1–4 mBq/L) in both cases, regardless of the contrasted geology (Mesozoic limestone vs crystalline Variscan basement), but clearly distinct (228Ra/226Ra) ratios in agreement with the differences in Th/U ratios of the two drained areas. Short-lived Ra isotopes (224Ra and 223Ra) appear to be mainly influenced by near-surface desorption/recoil processes for most of the sampling sites.
ISSN: 0969-8043

hal-01491281
https://hal.archives-ouvertes.fr/hal-01491281
DOI : 10.1016/j.apradiso.2016.12.010

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Little is known of how linkage patterns between species change along environmental gradients. The small, spatially discrete food webs inhabiting tank-bromeliads provide an excellent opportunity to analyse patterns of community diversity and food-web topology (connectance, linkage density, nestedness) in relation to key environmental variables (habitat size, detrital resource, incident radiation) and predators: prey ratios. We sampled 365 bromeliads in a wide range of understorey environments in French Guiana and used gut contents of invertebrates to draw the corresponding 365 connectance webs. At the bromeliad scale, habitat size (water volume) determined the number of species that constitute food-web nodes, the proportion of predators, and food-web topology. The number of species as well as the proportion of predators within bromeliads declined from open to forested habitats, where the volume of water collected by bromeliads was generally lower because of rainfall interception by the canopy. A core group of microorganisms and generalist detritivores remained relatively constant across environments. This suggests that (i) a highly-connected core ensures food-web stability and key ecosystem functions across environments, and (ii) larger deviations in food-web structures can be expected following disturbance if detritivores share traits that determine responses to environmental changes. While linkage density and nestedness were lower in bromeliads in the forest than in open areas, experiments are needed to confirm a trend for lower food-web stability in the understorey of primary forests.
PLoS ONE

hal-00913931
https://hal.archives-ouvertes.fr/hal-00913931
https://hal.archives-ouvertes.fr/hal-00913931/document
DOI : 10.1371/journal.pone.0071735
OATAO : 10204

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé :  
Modeling soil water availability for tropical trees is a prerequisite to predicting the future impact of climate change on tropical forests. In this paper we develop a discrete-time deterministic water balance model adapted to tropical rainforest climates, and we validate it on a large dataset that includes micrometeorological and soil parameters along a topographic gradient in a lowland forest of French Guiana. The model computes daily water fluxes (rainfall interception, drainage, tree transpiration and soil plus understorey evapotranspiration) and soil water content using three input variables: daily precipitation, potential evapotranspiration and solar radiation. A novel statistical approach is employed that uses Time Domain Reflectometer (TDR) soil moisture data to estimate water content at permanent wilting point and at field capacity, and root distribution. Inaccuracy of the TDR probes and other sources of uncertainty are taken into account by model calibration through a Bayesian framework. Model daily output includes relative extractable water, REW, i.e. the daily available water standardized by potential available water. The model succeeds in capturing temporal variations in REW regardless of topographic context. The low Root Mean Square Error of Predictions suggests that the model captures the most important drivers of soil water dynamics, i.e. water refilling and root water extraction. Our model thus provides a useful tool to explore the response of tropical forests to climate scenarios of changing rainfall regime and intensity.
ISSN: 0168-1923

hal-01032181
https://hal.archives-ouvertes.fr/hal-01032181
DOI : 10.1016/j.agrformet.2011.04.012

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Isotopic fractionation of tritium is a highly relevant issue in radiation protection and requires certain radioecological considerations. Sound evaluation of this factor is indeed necessary to determine whether environmental compartments are enriched/depleted in tritium or if tritium is, on the contrary, isotopically well-distributed in a given system. The ubiquity of tritium and the standard analytical methods used to assay it may induce biases in both the measurement and the signification that is accorded to the so-called fractionation: based on an exhaustive review of the literature, we show how, sometimes large deviations may appear. It is shown that when comparing the non-exchangeable fraction of organically bound tritium (neOBT) to another fraction of tritium (e.g. tritiated water) the preparation of samples and the measurement of neOBT reported frequently led to underestimation of the ratio of tritium to hydrogen (T/H) in the non-exchangeable compartment by a factor of 5 % to 50 %. In the present study, corrections are proposed for most of the biological matrices studied so far. Nevertheless, the values of isotopic fractionation reported in the literature remain difficult to compare with each other, especially since the physical quantities and units often vary between authors. Some improvements are proposed to better define what should encompass the concepts of exchangeable and non-exchangeable fractions.
ISSN: 0160-4120

hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744
https://hal.archives-ouvertes.fr/hal-01117744/document
https://hal.archives-ouvertes.fr/hal-01117744/file/Article%20review%20discrimination%20isotopique-envoy%C3%A9.pdf
DOI : 10.1016/j.envint.2013.12.020

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The paper presents coastal structures design in the presence of waves by the minimization of a cost function. It aims to show that shape optimization can be efficiently applied to ocean engineering. This is an underlying guiding principle for the design of harbors or offshore breakwaters. We compute the solution of a specific simplified boundary value problem describing the short wave propagation toward a vertical sea cliff or vertical wall and modify accordingly the shape of defense structures in order to minimize a pre-defined cost function taking into account the strength (energy) of the water waves. The optimization procedure relies on a global semi-deterministic search algorithm able to escape from local minima.
ISSN: 0378-3839

hal-00411905
https://hal.archives-ouvertes.fr/hal-00411905
DOI : 10.1016/j.coastaleng.2007.06.006

Résumé : Les réseaux de capteurs constituent un axe de recherche très fertile ces dernières années. Cette technique se développe dans différents domaines comme l'environnement, l'industrie, le commerce, la médecine, l'armée, etc. Les réseaux de capteurs sont difficiles à concevoir parce qu'ils sont fortement contraints en énergie et que tous les éléments ont potentiellement une influence sur la durée de vie du système. Nous proposons un outil permettant l'aide au bon paramétrage et aux choix de paramètres optimaux pour la stabilité des applications.Dans cette thèse, nous nous sommes intéressés à deux problématiques : une classification des paramètres pour un outil d'aide à la décision pour la configuration d'un réseau de capteurs et la seconde, un outil de test de conformité du système dans un environnement réel. Le document est divisé en deux parties où la première partie est un état de l'art de différents protocoles existants et la deuxième partie décrit notre contribution dans ces deux problématiques.Dans la première contribution, nous avons analysé l'impact de la couverture radio puis de la topologie sur les performances d'un réseau de capteurs. Nous étudions le taux de perte et le niveau d'énergie pour en déduire la stabilité d'une application. Puis nous avons proposé une étude menant à une classification pour notre outil d'aide à la décision. Notre classification est basée sur une étude de divers paramètres de la couche MAC, physique, protocole de routage, nombre de nœuds et type d'application.Dans la deuxième contribution, nous nous sommes focalisés sur une approche pragmatique permettant de tester la conformité d'un réseau de capteurs dans un environnement réel. Pour tester la conformité dans un environnement réel, nous proposons une architecture d'exécution de test sur un réseau de capteurs réel. Ceci dans un but d'assurer un niveau correct de conformité et la stabilité de celui-ci durant son fonctionnement.
Wireless sensor networks is one of the hotest research topic in the last few years. This technology can be applied for different fields such as environment, industry, trading, medicine, military etc. Wireless sensor networks are hard to conceive because they require a lot of energy and because each of its component may have an influence on the lifetime of the whole system. What we suggest is a tool allowing to choose the correct and optimal parameters for the reliability of the applications.In this thesis, we focused on two major problems : firstly, a classification of the parameters for a tool allowing to make decisions about the configuration of a wireless sensors network, and secondly, a tool testing the compliance of the system with a real environment. The document is divided into two parts : the first part states the different protocols that exist, and the second part describes our contributions to those topics.In the first contribution, we analyzed how influential the radio cover and the network topology are on the network performances. Then, we deduced from the study of the loss rate and of the level of energy, the reliability of the application. Next, we suggested a study leading to a classification for our decision making tool. For this classification, we studied various parameters related to the MAC layer, the Physical layer, the network layer, the application layer the number of nodes involved in the network.In the second contribution, we adopted a pragmatic approach so we could test the conformity of a wireless sensors network in a real environment. In order to test its conformity in a real environment, we suggested a structured test execution on a real wireless sensor network. This task has been suggested in order to check the conformance level of the network while it was working.

http://www.theses.fr/2012AGUY0586/document

Éditeur(s) : HAL CCSD Intech
Résumé : International audience
The massive integration of sustainable energies into electrical grids (non-interconnectedor connected) is a major problem due to their stochastic character revealed by strongfluctuations at all scales. In this paper, the scaling behaviour or power law correlationsand the nature of scaling behaviour of sustainable resource data such as flow velocity,atmospheric wind speed, solar global solar radiation and sustainable energy such as,wind power output, are highlighted. For the first time, Fourier power spectral densitiesare estimated for each dataset. We show that the power spectrum densities obtained areclose to the 5/3 Kolmogorov spectrum. Furthermore, the multifractal and intermittentproperties of sustainable resource and energy data have been revealed by the concavityof the scaling exponent function. The proposed analysis frame allows a full descriptionof fluctuations of processes considered. A good knowledge of the dynamic of fluctua-tions is crucial to management of the integration of sustainable energies into a grid.
Sustainable Energy - Technological Issues, Applications and Case Studies

hal-01528087
https://hal.archives-ouvertes.fr/hal-01528087
DOI : 10.5772/106341

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Polarized emittance measurements were acquired for synthetic forsterite, the pure magnesium end member of the olivines group, on the whole infrared spectral range and up to the melting point by using CO2 laser heating. The experimental data, fitted with a semi-quantum dielectric function model, allowed the retrieval of the temperature dependence of the absorption coefficient of forsterite both in the opaque and semi-transparent regions. The analysis of the phonon parameters indicates that the lattice dynamics evolve drastically with increasing temperature. The normal modes involving motions of the magnesium cations located in site 1 are the more impacted, and some of them vanish around 1,200 K. The results confirm that the enhancement of the lattice anharmonicity and the increasing mobility of the magnesium cations are closely linked and are at the origin of the anomalies observed in the evolution of the thermophysical properties. This complete set of spectroscopic data may be a step toward a more precise evaluation of the impact of thermal radiation heat transfer inside systems involving forsterite and quantification of their heat budget.
ISSN: 0342-1791

hal-00817079
https://hal.archives-ouvertes.fr/hal-00817079
DOI : 10.1007/s00269-013-0570-z

Éditeur(s) : HAL CCSD
Résumé : International audience
The Heliosat-II method was developed to process Meteosat satellite images in order to assess the solar irradiation at surface. It is modified for its use with GOES satellite images in order to estimate the solar irradiation over French Guiana.Modifications include a change in the calibration formula, in the calculation of the cloud albedo, and in the values of the Linke turbidity factor. These modifications allow the improvement of the performances of the Heliosat-II model in Intertropical zones in French Guiana. The outcomes were compared to coincident measurements of hourly irradiation performed by ground stations.The results show that the use of the maximum apparent albedo as the cloud albedo (ρcmax), along with a fixed value of the Linke turbidity factor produces the best results; the bias was less than 23.61 Wh/m2 (5% of the mean value of the measurements) overall, and the RMSE was less than 109.39 W/m2 (24%) overall when using hourly values. In the case of daily means, the RMSE drops to less than 10.08 W/m2 (10%) overall, whereas the overall bias remains unchanged, as expected. The model performs better in clear skies than in cloudy skies. The results suggest that the Linke turbidity factor used in the Heliosat-II method does not reproduce well the attenuation of the solar radiation in French Guiana. The results were compared to those obtained from Heliosat II method and Meteosat images (HelioClim-3 database) and we found a better accuracy for GOES satellite data, which exhibits smaller viewing angle. The use of the Heliosat II method with GOES images allows assessment of the SSI with a good accuracy and high temporal and spatial resolutions.
Canadian Journal of Remote Sensing

meteo-01304576
https://hal-meteofrance.archives-ouvertes.fr/meteo-01304576
DOI : 10.1080/07038992.2015.1040876

Éditeur(s) : HAL CCSD Museum National d'Histoire Naturelle Paris
Résumé : This study focuses on new fossil faunas of bats discovered in North Africa following several field campaigns. The fossiliferous localities include those from the Early to Middle Eocene of Tunisia (Chambi) and Algeria (Glib Zegdou). Systematic and cladistic analyses carried out on the fossil material, primarily including isolated teeth, allow us to highlight the modalities of the radiation of the first modern microbats. These new faunas include eight well-identified new taxa belonging to five modern families: one Necromantidae (?Necromantis fragmentum Ravel, n. sp.), two Hipposideridae Miller, 1907 (?Palaeophyllophora tunisiensis Ravel, n. sp. and Hipposideros [Pseudorhinolophus] africanum Ravel, n. sp.), three Emballonuridae Gervais in de Castelnau, 1855 (Vespertiliavus kasserinensis Ravel, n. sp., ?Vespertiliavus aenigma Ravel, n. sp., and Pseudovespertiliavus parva Ravel n. gen., n. sp.), one Nycteridae (Khoufechia gunnelli Ravel n. gen., n. sp.) and an undetermined Vespertilionidae. Two other taxa are identified (Chambinycteris pusilli Ravel n. gen., n. sp. and Drakonycteris glibzegdouensis Ravel n. gen., n. sp.), but they show an original dental pattern which precludes a family attribution. Two cladistic analyses allow to clarify the phylogenetic position of the best documented taxa. The results highlight for Hipposideridae and Emballonuridae chiropterans a major dispersal axis from North Africa towards South Europe during the Middle Eocene.
ISSN: 1280-9659

hal-01467508
https://hal.archives-ouvertes.fr/hal-01467508
DOI : 10.5252/g2016n3a3

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Although ants may induce community-wide effects via changes in physical habitats in terrestrial environments, their influence on aquatic communities living in plant-held waters remains largely underexplored. The neotropical tank-bromeliad Aechmea mertensii (Bromeliaceae) occurs along forest edges in ant-gardens initiated by Camponotus femoratus or by Pachycondyla goeldii. Its leaves form wells that hold rainwater and provide suitable habitats for many aquatic organisms. We postulated that these ant-plant mutualisms indirectly affect the microbial community structure via changes in the environmental conditions experienced by the plants. To test this hypothesis, we analyzed the protist communities from 63 tank-bromeliads associated with either C. femoratus or P. goeldii (hereafter Cf-Aechmea and Pg-Aechmea) along a forest edge in French Guiana. For each plant, a large number of environmental variables (including habitat structure, food resources, incident radiation and the presence of aquatic invertebrates) were quantified to determine their relative importance in driving any observed differences across ant-associated plants. Pg-Aechmea are located in sun-exposed areas and hold low volumes of water and low amounts of detritus, whereas Cf-Aechmea are located in partially shaded areas and accumulate higher amounts of water and detritus. Protists (i.e., protozoa and algae) inhabiting Cf-Aechmea exhibit greater richness and abundances than those in Pg-Aechmea. Variations in detritus content, number of leaves, incident radiation, and the epiphyte richness of the ant-garden were the main factors explaining the variation in protist richness. A shift in the functional group composition of protists between bromeliads tended by different ant species suggested that mutualistic ants indirectly mediate changes in the microbial food web.
Basic and Applied Ecology

hal-00913126
https://hal.archives-ouvertes.fr/hal-00913126
https://hal.archives-ouvertes.fr/hal-00913126/document
DOI : 10.1016/j.baae.2012.10.002
OATAO : 10190

Éditeur(s) : HAL CCSD INVS
Résumé : National audience
Context – Cervical cancer is the second most frequent cancer of women in French Guiana. Studies have shown that populations living in remote villages in the interior of the territory have early sexual relations and that multiple sexual partnerships are frequent. Hence, the main objective of the study was to determine the prevalence of Human Papilloma Virus (HPV) in these areas.Methods – This multicentric cross sectional study was conducted in women aged 20 to 65 years, living in theremote villages along the Maroni and Oyapock rivers. Women were included on a voluntary basis after beinginformed of the study team schedule through radio address and key opinion leaders.The search for HPV and cytologic examinations were performed on each sample. HPV infection was defined bythe detection of viral DNA using the Greiner Bio One® kit. Cytologic analyses were performed using the 2001Bethesda classification.Results – Overall, 643 women were included in the study. Age-standardized HPV prevalence was 35%. Theprevalence curve by age group showed a U-shaped pattern: women over 50 years had the highest risk of being infected by HPV, followed by women aged 20-29 years. In addition, 26.1% of women with a normal smear test had HPV infection. The most frequent genotypes were HPV52, HPV58, and HPV16. On interpretable smears 1.16% of women had high grade superficial intra-epithelial (HSIL) lesions.Conclusions – The standardized prevalence of HPV in French Guiana is among the highest in the world. HSILcytological lesions were nearly 4 times more frequent than in the Île-de-France region. Given the importance of the incidence of cervical cancer in French Guiana, these results suggest it may be preferable to use HPV testing than cytology. Vaccination against HPV, preferably with the new nonavalent vaccine seems an appropriate prevention measure. However, this intervention will be a challenge to implement in this region where a significant proportion of the population is not covered by health insurance.
Contexte – Le cancer du col de l’utérus est le deuxième cancer féminin le plus fréquent en Guyane française.Des études ont montré que les populations résidant dans les communes isolées de l’intérieur du départementdébutent leur vie sexuelle de façon précoce et que le multipartenariat sexuel y est fréquent. Dans ce contexte, l’objectif principal de cette étude était de déterminer la prévalence de l’infection à papillomavirus humains (HPV) dans ces zones.Méthodes – Cette étude transversale multicentrique a été conduite auprès des femmes âgées de 20 à 65 ansrésidant dans les communes isolées des fleuves Maroni et Oyapock. Les femmes étaient incluses sur la basedu volontariat après avoir été informées du passage de l’équipe de l’étude via la radio locale et par les leadersd’opinion. La recherche d’infection à HPV et les analyses cytologiques ont été réalisées sur chaque prélèvement. L’infection à HPV était définie par la détection d’ADN viral par le kit de dépistage Greiner Bio One®. Les analyses cytologiques ont été décrites selon la classification de Bethesda 2001.Résultats – Au total, 643 femmes ont été incluses. La prévalence de l’infection à HPV, standardisée sur l’âge,était de 35%. La courbe de prévalence par classe d’âge présentait une forme en U : les femmes de plus de50 ans avaient le plus haut risque d’être infectées par HPV, suivies par les femmes âgées de 20 à 29 ans.Par ailleurs, 26,1% des femmes ayant un frottis normal étaient infectées par le HPV. Les génotypes les plusfréquents étaient HPV52, HPV58 et HPV16. Sur les frottis interprétables, 1,16% des femmes avaient des lésions de haut grade (type HSIL).Conclusions – Le taux standardisé de prévalence de l’infection par le HPV en Guyane est parmi les plus élevésau monde. Les lésions cytologiques de type HSIL étaient près de 4 fois plus fréquentes qu’en Île-de-France.Étant donné l’importance de l’incidence du cancer du col de l’utérus en Guyane, ces résultats montrent qu’il est peut être préférable d’utiliser le test HPV plutôt que la cytologie. La vaccination anti-HPV, de préférence avec le nouveau vaccin nonavalent, semble être une mesure de prévention appropriée. Pour autant, cela reste un challenge de mettre en oeuvre ces interventions dans cette région où une part importante de la population n’a pas d’assurance maladie.
ISSN: 1953-8030

Droits : info:eu-repo/semantics/OpenAccess
inserm-01407222
http://www.hal.inserm.fr/inserm-01407222
http://www.hal.inserm.fr/inserm-01407222/document
http://www.hal.inserm.fr/inserm-01407222/file/2016%2C%20Dufit%20et%20al.pdf

Éditeur(s) : Mercator Ocean
Résumé : Face to the lack of data to assess precisely the spatial distribution of catches and fishing effort and for the environmental characterization of the fishing area, Ifremer has been implemented since 2005 a new project, Recopesca. It consists in fitting out a sample of voluntary fishing vessels with sensors recording data on fishing effort (and at mid-terms catches) and physical parameters such as temperature or salinity. Recopesca aims at setting up a network of sensors, for scientific purposes, to collect data and improve resources assessment and diagnostics on fisheries, and environmental data required for ecosystem-based management initiatives. The challenge was to develop sensors with no trouble for the fishermen, tough enough to be fixed up on fishing gears, self powered and autonomous. Insofar as the sample of targeted vessels intends to be representative of all the metiers and fleets, the sensors are modular and scalable to collect new data. Different sensors have been implemented: (i) a temperature-salinity sensor, able to record physical parameters, depth and duration of immersion, for passive and active gears, and (ii) a specific sensor to record number or length of passive gears. A GPS monitors the position of the vessels and the temperature or salinity profiles and series. Each sensor is equipped with a radio device transferring the data to a receiver on-board, called “concentrator” that sends the data to Ifremer central databases by GPRS. An anti-rolling weigh-scale has been developed and is currently on test to record catches per species and fishing operation. The presentation will show the first data and results of this participative approach.
Mercator Ocean - Quarterly Newsletter (Mercator Ocean), 2010-04 , N. 37 , P. 40-48

Droits : 2010 Mercator Ocean
http://archimer.ifremer.fr/doc/00024/13500/10514.pdf
http://archimer.ifremer.fr/doc/00024/13500/

Éditeur(s) : HAL CCSD IOP Publishing
Résumé : International audience
Based on the very recent work by Censor and Segal (2009 J. Convex Anal. 16 587-600) and inspired by Xu (2006 Inverse Problems 22 2021-34) and Yang (2004 Inverse Problems 20 1261-6), we investigate an algorithm for solving the split common fixed-point problem for the class of demicontractive operators in a Hilbert space. Our results improve and/or develop previously discussed feasibility problems and related algorithms. It is worth mentioning that the convex feasibility formalism is at the core of the modeling of many inverse problems and has been used to model significant real-world problems, for instance, in sensor networks, in radiation therapy treatment planning, in computerized tomography and data compression, see Censor et al (2006 Phys. Med. Biol. 51 2353-65) and Combettes (1996 Adv. Imaging Electron. Phys. 95 155-270) and references therein.
ISSN: 0266-5611

hal-00778174
https://hal.univ-antilles.fr/hal-00778174
DOI : 10.1088/0266-5611/26/5/055007

Éditeur(s) : HAL CCSD
Résumé : International audience
Several forthcoming wireless telecommunication systems will use electromagnetic frequencies at millimeter waves (MMWs), and technologies developed around the 60-GHz band will soon know a widespread distribution. Free nerve endings within the skin have been suggested to be the targets of MMW therapy which has been used in the former Soviet Union. So far, no studies have assessed the impact of MMW exposure on neuronal metabolism. Here, we investigated the effects of a 24-h MMW exposure at 60.4 GHz, with an incident power density (IPD) of 5 mW/cm2, on the dopaminergic turnover of NGF-treated PC12 cells. After MMW exposure, both intracellular and extracellular contents of dopamine (DA) and 3,4-dihydroxyphenylacetic acid (DOPAC) were studied using high performance liquid chromatography. Impact of exposure on the dopamine transporter (DAT) expression was also assessed by immunocytochemistry. We analyzed the dopamine turnover by assessing the ratio of DOPAC to DA, and measuring DOPAC accumulation in the medium. Neither dopamine turnover nor DAT protein expression level were impacted by MMW exposure. However, extracellular accumulation of DOPAC was found to be slightly increased, but not significantly. This result was related to the thermal effect, and overall, no evidence of non-thermal effects of MMW exposure were observed on dopamine metabolism. © 2017 The Author. Published by Oxford University Press on behalf of The Japan Radiation Research Society and Japanese Society for Radiation Oncology.
Journal of Radiation Research

hal-01580502
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01580502
DOI : 10.1093/jrr/rrx004
PUBMED : 28339776

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Background: Health care workers (HCWs) are occupationally exposed to various hazards, some associated with adverse pregnancy outcomes in previous reviews. This systematic review aims at synthesizing the recent literature on occupational exposures among HCWs related to fetal death, congenital anomalies, and fertility disorders. Methods: We searched the Medline database from 2000 to 2015 for articles about all potential occupational exposures of women and men working in this sector. Results: We retained 32 studies, most of them (n = 30) among women HCWs. Studies based on job title reported excess risks of some congenital anomalies (especially nervous and musculoskeletal systems) among HCWs compared to non-HCWs but no evidence about fetal death. Excess risks associated with specific exposures includes reports of some congenital anomalies forwomenexposed to anesthetic gases. Exposure to some sterilizing agents and, with less evidence, to antineoplastic drugs and to ionizing radiation, is associated with increased risks of miscarriage but not stillbirth. Strenuous work schedules appear to be associated with fertility disorders, but the evidence is limited. Only a few studies have been published since 2000 about non-ionizing radiation, or about fertility disorders related to chemical or physical agents, or about male HCWs. Conclusions: Despite the establishment of recommendations to limit exposures of HCWs, some excess risks of adverse pregnancy outcomes are still reported and need to be explained.
ISSN: 0271-3586

hal-01560148
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01560148
DOI : 10.1002/ajim.22711
PUBMED : 28514021

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The purpose of this article is to improve modeling of solar irradiance through the analysis of measurement data on the ground in the intertropical zone. For this, we identify, using information criteria, the probabilistic distributions introduced in two models of synthetic solar irradiance generation. We then validate the results by using the KL divergence and KSI parameter as comparison criteria between distributions arising from real and synthesized data. Our study confirms, for example, that the Gaussian classical distribution is not suitable for modeling solar irradiance, and we propose other more suitable statistical laws instead. The value of the identification procedure of the distribution laws presented in this article is that it ensures the production of solar irradiance data comparable in their statistical content to the measured data. Another advantage is that this procedure contributes to highlighting the time invariance of distribution laws representing the random terms. We conclude that this new information-criteria-based method permits the identification of the probability laws that best describe the statistical distributions introduced in models of synthetic solar irradiance generation.
ISSN: 0038-092X

meteo-01304572
https://hal-meteofrance.archives-ouvertes.fr/meteo-01304572
https://hal-meteofrance.archives-ouvertes.fr/meteo-01304572/document
https://hal-meteofrance.archives-ouvertes.fr/meteo-01304572/file/Manuscript_Hal.pdf
DOI : 10.1016/j.solener.2016.02.038

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : A development programme for the promotion of FADs in Sao Tome and Principe has implemented an original interactive approach by granting a predominant place to the initiative of the target group and its participation in decision making. The appropriation process of the innovative fads by the beneficiaries takes place in three stages described herewith. the technical research phase. This consists of formally describing an idea in reply to an expressed or potential need. The envisaged fad type is developed and tested by the project's agents in order to obtain a technically appropriate prototype.- the research and adjustment phase. The fad is given to a small number of people to be used in real-life conditions. Reaction surveys will enable its pertinence to be tested and its adaptation to normal conditions of use. This second phase results in the production of a technically and socio-economically appropriated fad. - the diffusion-perpetuation phase. This entails i) identification of the sequences of the various stages, ii) definition and grouping of contributions by the various parties, iii) production of educational auxiliaries, iv) initiating actions for user awareness and demonstration, v) staff training, vi) monitoring of the fad "socialisation", vii) solving funding problems.Original Abstract: Un projet visant, entre autres, la promotion de DCP pour la peche artisanale fonctionne a Sao Tome et Principe depuis 1993. Le processus d'appropriation daune telle innovation par les beneficiaires comprend trois etapes ici decrites. La phase de recherche technique. Il s'agit d'instrumentaliser une idee en reponse a un besoin exprime ou potentiel. L'innovation envisagee est mise au point et testee par les agents du projet en milieu controle de facon a obtenir un prototype techniquement approprie. La phase de recherche-developpement: l'outil est confie a un petit nombre de personnes pour une utilisation en conditions reelles. C'est une phase de mise au point interactive, seule susceptible de provoquer une reelle appropriation par les recipiendaires. Des enquetes de reaction permettront de tester sa pertinence et de l'adapter aux conditions normales d'utilisation. Cette seconde phase debouche sur la production d'un outil de reference approprie techniquement et socio-economiquement. La phase de diffusion-perennisation: il s'agira la : i) d'identifier les sequences d'intervention, ii) d'identifier et de regrouper les apports des differentes parties, iii) de definir et de produire les auxiliaires pedagogiques (manuels, affiches, radio), iv) d'entreprendre des actions de sensibilisation et de demonstration, v) de former les personnels, vi) de veiller a la socialisation de l'innovation, pour les outils collectifs, vii) de resoudre le probleme du financement.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15306/12641.pdf
http://archimer.ifremer.fr/doc/00042/15306/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
UNLABELLED: ABSTRACT: BACKGROUND: Malaria remains a major health problem in French Guiana, with a mean of 3800 cases each year. A previous study in Camopi, an Amerindian village on the Oyapock River, highlighted the major contribution of environmental features to the incidence of malaria attacks. We propose a method for the objective selection of the best multivariate peridomestic landscape characterisation that maximises the chances of identifying relationships between environmental features and malaria incidence, statistically significant and meaningful from an epidemiological point of view. METHODS: A land-cover map, the hydrological network and the geolocalised inhabited houses were used to characterise the peridomestic landscape in eleven discoid buffers with radii of 50, 100, 200, 300, 400, 500, 600, 700, 800, 900 and 1000 metres. Buffer-based landscape characterisations were first compared in terms of their capacity to discriminate between sites within the geographic space and of their effective multidimensionality in variable space. The Akaike information criterion (AIC) was then used to select the landscape model best explaining the incidences of P. vivax and P. falciparum malaria. Finally, we calculated Pearson correlation coefficients for the relationships between environmental variables and malaria incidence, by species, for the more relevant buffers. RESULTS: The optimal buffers for environmental characterisation had radii of 100 m around houses for P. vivax and 400 m around houses for P. falciparum. The incidence of P. falciparum malaria seemed to be more strongly linked to environmental features than that of P. vivax malaria, within these buffers. The incidence of P. falciparum malaria in children was strongly correlated with proportions of bare soil (r = -0.69), land under high vegetation (r = 0.68) and primary forest (r = 0.54), landscape division (r = 0.48) and the number of inhabited houses (r = -0.60). The incidence of P. vivax malaria was associated only with landscape division (r = 0.49). CONCLUSIONS: The proposed methodology provides a simple and general framework for objective characterisation of the landscape to account for field observations. The use of this method enabled us to identify different optimal observation horizons around houses, depending on the Plasmodium species considered, and to demonstrate significant correlations between environmental features and the incidence of malaria.
ISSN: 1476-072X

inserm-00674075
http://www.hal.inserm.fr/inserm-00674075
http://www.hal.inserm.fr/inserm-00674075/document
http://www.hal.inserm.fr/inserm-00674075/file/1476-072X-10-65.pdf
DOI : 10.1186/1476-072X-10-65