[hal-01118445] Multi-locus microsatellite analysis supports the hypothesis of an autochthonous focus of Echinococcus multilocularis in northern Italy.
19 février 2015
Echinococcus multilocularis is characterised by a wide geographical distribution, encompassing three continents (North America, Asia and Europe) yet very low genetic variability is documented. Recently, this parasite has been detected in red foxes (Vulpes vulpes) circulating in an Alpine region of Italy, close to Austria. This finding raised the question as to whether an autochthonous cycle exists in Italy or whether the infected foxes originated from the neighbouring regions of Austria. Studies have shown that multi-locus microsatellite analysis can identify genomic regions carrying mutations that result in a local adaptation. We used a tandem repeated multi-locus microsatellite (EmsB) to evaluate the genetic differences amongst adult worms of E. multilocularis collected in Italy, worms from neighbouring Austria and from other European and extra-European countries. Fluorescent PCR was performed on a panel of E. multilocularis samples to assess intra-specific polymorphism. The analysis revealed four closed genotypes for Italian samples of E. multilocularis which were unique compared with the other 25 genotypes from Europe and the five genotypes from Alaska. An analysis in the Alpine watershed, comparing Italian adult worms with those from neighbouring areas in Austria, showed a unique cluster for Italian samples. This result supports the hypothesis of the presence of an autochthonous cycle of E. multilocularis in Italy. EmsB can be useful for 'tracking' the source of infection of this zoonotic parasite and developing appropriate measures for preventing or reducing the risk of human alveolar echinococcosis.
[hal-01118443] The EmsB tandemly repeated multilocus microsatellite: a new tool to investigate genetic diversity of Echinococcus granulosus sensu lato.
19 février 2015
Cystic echinococcosis (CE) is a widespread and severe zoonotic disease caused by infection with the larval stage of the eucestode Echinococcus granulosus sensu lato. The polymorphism exhibited by nuclear and mitochondrial markers conventionally used for the genotyping of different parasite species and strains does not reach the level necessary for the identification of genetic variants linked to restricted geographical areas. EmsB is a tandemly repeated multilocus microsatellite that proved its usefulness for the study of genetic polymorphisms within the species E. multilocularis, the causative agent of alveolar echinococcosis. In the present study, EmsB was used to characterize E. granulosus sensu lato samples collected from different host species (sheep, cattle, dromedaries, dogs, and human patients) originating from six different countries (Algeria, Mauritania, Romania, Serbia, Brazil, and the People's Republic of China). The conventional mitochondrial cox1 and nad1 markers identified genotypes G1, G3, G5, G6, and G7, which are clustered into three groups corresponding to the species E. granulosus sensu stricto, E. ortleppi, and E. canadensis. With the same samples, EmsB provided a higher degree of genetic discrimination and identified variations that correlated with the relatively small-scale geographic origins of the samples. In addition, one of the Brazilian single hydatid cysts presented a hybrid genotypic profile that suggested genetic exchanges between E. granulosus sensu stricto and E. ortleppi. In summary, the EmsB microsatellite exhibits an interesting potential for the elaboration of a detailed map of the distribution of genetic variants and therefore for the determination and tracking of the source of CE.
[hal-01118392] Serological studies of neurologic helminthic infections in rural areas of southwest cameroon: toxocariasis, cysticercosis and paragonimiasis.
19 février 2015
Both epilepsy and paragonimiasis had been known to be endemic in Southwest Cameroon. A total of 188 people (168 and 20 with and without symptoms confirmed by clinicians, respectively, 84.6% under 20 years old) were selected on a voluntary basis. Among 14 people (8.3%) with history of epilepsy, only one suffered from paragonimiasis. Therefore, we challenged to check antibody responses to highly specific diagnostic recombinant antigens for two other helminthic diseases, cysticercosis and toxocariasis, expected to be involved in neurological diseases. Soil-transmitted helminthic infections were also examined. Fecal samples were collected exclusively from the 168 people. Eggs of Ascaris lumbricoides, Trichuris trichiura and hookworms were found from 56 (33.3%), 72 (42.8%), and 19 (11.3%) persons, respectively. Serology revealed that 61 (36.3%), 25 (14.9%) and 2 (1.2%) of 168 persons showed specific antibody responses to toxocariasis, paragonimiasis and cysticercosis, respectively. By contrast, 20 people without any symptoms as well as additional 20 people from Japan showed no antibody responses. Among the 14 persons with epilepsy, 5 persons were seropositive to the antigen specific to Toxocara, and one of them was simultaneously positive to the antigens of Paragonimus. The fact that 2 children with no history of epilepsy were serologically confirmed to have cysticercosis strongly suggests that serological survey for cysticercosis in children is expected to be useful for early detection of asymptomatic cysticercosis in endemic areas. Among persons surveyed, toxocariasis was more common than paragonimiasis, but cysticercosis was very rare. However, the fact that 2 children were serologically confirmed to have cysticercosis was very important, since it strongly suggests that serology for cysticercosis is useful and feasible for detection of asymptomatic cysticercotic children in endemic areas for the early treatment.
[hal-00465417] Aortic valve replacement for active infective endocarditis: 5-year survival comparison of bioprostheses, homografts and mechanical prostheses.
9 décembre 2014
Objective: In the surgical treatment of acute aortic valve infective endocarditis (IE), the long-term outcome depending on the choice of valve replacement remains uncertain. We aimed to compare the impact on 5-year mortality of use of three types of implanted valves: bioprosthesis (heterograft), mechanical prosthesis and homograft. Methods: A total of 167 patients with a definite aortic valve IE who underwent aortic replacement were selected from a prospective observational population-based study. Association between the type of implanted valve and 5-year mortality was examined by the use of an adjusted Cox model. Results: Bioprostheses were implanted in 31 patients (18.6%), homograft in 27 (16.2%) and mechanical valves in 109 (65.2%). Patients with bioprothesis had a higher 5-year mortality risk than patients with mechanical prosthesis (adjusted hazard ratio (HR) 2.39, 95% confidence interval (95% CI), 1.09-5.21; p=0.029), particularly in patients 65 years old (adjusted HR: 1.45 (0.35-5.97), p=0.60). Five-year mortality risk did not differ between patients with homografts and those with mechanical prostheses (HR 0.46, 95% CI (0.15-1.42), p=0.18). Conclusions: A bioprosthetic valve used for aortic valve IE replacement may be associated with lower overall 5-year survival than the use of a mechanical valve in patients up to 65 years old. Further studies are needed to explain these results.
[hal-00465392] The impact of valve surgery on short- and long-term mortality in left-sided infective endocarditis: do differences in methodological approaches explain previous conflicting results?
9 décembre 2014
Aims The aim of this study was to evaluate the effect of valve surgery (VS) in infective endocarditis (IE) on 5-year mortality and to evaluate whether conflicting results reported by previous studies could be due to differences in their methodological approaches. Methods and results Four hundred and forty-nine patients with a definite left-sided IE were selected from a prospective, population-based study. Association between VS and 5-year mortality was examined with a Cox model. To determine the impact of different methodological approaches, we also analysed the relationship between VS and mortality in our database, according to each method used in the five previous studies. Valve surgery was performed in 240 patients (53%). It was associated with an increase in short-term mortality [within the first 14 post-operative days; adjusted hazard ratio (HR), 3.69; 95% confidence interval (CI), 2.17-6.25; P < 0.0001] and a decrease in long-term mortality (adjusted HR, 0.55; 95% CI, 0.35-0.87; P = 0.01). At least 188 days of follow-up were required for VS to provide an overall survival advantage. When applying each study's method to our database, we obtained results similar to those reported. Conclusion Previous conflicting results appear to be related to differences in statistical methods. When using appropriate models, we found that VS was significantly associated with reduced long-term mortality.
[hal-00481851] Environments and societies of small Caucasus (Armenia) in the light of the Quaternary climatic changes and landscape mutations.
9 décembre 2014
N/A
[hal-00419940] The climate in central Italy during the last 15,000 yrs BP: seasonality changes inferred from pollen and lake levels
1er décembre 2014
N/A
[hal-00421405] Various Litter Species and High Water-Table Levels Hamper Type II Methanotrophs in a Bare Peatland Regeneration Experiment
27 novembre 2014
Significant areas of temperate bogs have been damaged by peat harvesting. After abandonment and spontaneous regeneration, these secondary mires can become important methane sources towards the atmosphere (Basiliko et al., 2007). Recent studies have shown the importance of methane oxidising bacteria (MOB) for the recycling of carbon from methane effluxes (e.g., Dedysh et al., 2001; Raghoebarsing et al., 2005). We set up a factorial experiment that allowed us to tests the effects of three levels of naturally fluctuating water table depths (13, 22, 35 cm) crossed with the effects of four different litter types (control, E. vaginatum, E. angustifolium, S. fallax). With help of improved 16 rRNA fluorescent in-situ hybridisation techniques we quantified the number of type II methane oxidising bacteria (MOB) living at different depths and just bellow the surface. The results show that the water table can strongly influence the active type II methan-otrophs living in the first 5 cm of the regenerating bare peat. These methane oxidis-ing bacteria were also hampered by the presence of plant litter placed on top of the bare peat surface. This could have important implication for the methane oxidation potential of methane and on restoration management practices.
[hal-00448341] Various litter species and high water-table levels hamper type II methanotrophs in a bare peatland regeneration experiment.
27 novembre 2014
N/A
[hal-01067221] Sediment dynamic, channel morphology and ecological restoration downstream a dam : the case of the Ain river
29 octobre 2014
[...]
[halshs-00421624] Applied geophysics in archaeological prospecting at sites of Authumes (Saône-et-Loire) and Mirebeau (Côte-d'Or) (Bourgogne, Eastern France)
29 octobre 2014
N/A
[halshs-00739448] Pompeian millstones in France
29 octobre 2014
Pompeian millstones are known by their characteristic shape and size. They consist of an hourglass-shaped (bi-conical) upper stone (catillus) and a conical lower stone (meta). The larger models were driven by animals (hence their name, 'donkey mills') by means of fittings inserted in lugs on opposite sides of the catillus. The inclination of the grinding surfaces is very important. Recent research has proved, contrary to established assumption, that this type of mill was quite common in Narbonese Gaul. In this Roman Province, all of these mills are made of volcanic rock. The source of this volcanic rock is most likely the Italian peninsula, specifically the region of Orvieto. Although this distinctive rock was also used for other types of large (hydraulic?) millstones and small hand-operated rotary querns, it was mainly used for Pompeian millstones. Beyond southern France, no comprehensive survey of this type of mill has yet been conducted. Several are known in Amiens, Lyon, Paris, Troyes, etc. Unlike the finds from southern France, not all are of volcanic rock. Most come from excavations of urban sites. The aim of this study is to provide a first distribution of Pompeian mills across French territory. For this study, the factors taken into account are raw material, chronology, and the context of each find
[halshs-00705210] Les temples du sanctuaire gallo-romain de Ribemont-sur-Ancre, Somme
29 octobre 2014
[...]
[halsde-01072139] Do parafluvial zones have an impact in regulating river pollution? Spatial and temporal dynamics of nutrients, carbon, and bacteria in a large gravel bar of the Doubs River (France)
28 octobre 2014
The changes in both physical and chemical properties of interstitial water were investigated within a large gravel bar to determine if the parafluvial zone was a hotspot for nutrient transformations in a lowland eutrophic river, the Doubs (Eastern France). Interstitial water was sampled in 30 piezometers along five transects across the gravel bar, surface water was sampled in main and chute channels. Five campaigns of sampling were performed among summer and winter. In both interstitial and surface samples, water chemistry (electrical conductivity, pH, chloride, dissolved oxygen concentrations-DO) and nutrient concentrations (nitrate-NO3 (-), ammonium-NH4 (+), soluble reactive phosphorus-SRP, dissolved organic carbon-DOC) were measured. Moreover, temperature, water level, sediment grain size distribution and total bacterial abundance were assessed along a flowpath through a lateral gravel bar of the Doubs River. Measurements of water table elevation in the bar, main and chute channels indicated that the parafluvial flowpath was perpendicular to the main channel. Very low changes in chloride concentration and electrical conductivity showed minor groundwater input along the flowpath. The parafluvial zone was 0.9 m thick under the mean piezometric level, hydraulic gradients along the flowpath were 0.3%, and the discharge of interstitial water through the bar calculated at low flow was 40.6 m(3) day(-1). Most changes in interstitial nutrients occurred during the warm season, suggesting that biotic mechanisms occurred. Along the flowpath, DO, DOC, and bacterial abundance declined, while phosphate increased. Temporal trends of nitrate were less clear, exhibiting a slight increase during spring (organic matter biodegradation) and a decrease during summer (denitrification). Using the parafluvial discharge and nutrient concentrations of water infiltrating into and seeping from the gravel bar, the retention capacity of the bar was 171 gC day(-1) for DOC and 48.3 gN day(-1) for nitrate. Phosphate production ranged from 0.65 to 2.3 gP day(-1). These values were low compared to the nutrient fluxes in the river Doubs, suggesting a minimal local impact of the parafluvial zone in regulating of river pollution.
[hal-00382583] Do parafluvial zones have an impact in regulating river pollution? Spatial and temporal dynamics of nutrients, carbon, and bacteria in a large gravel bar of the Doubs River (France)
13 octobre 2014
The changes in both physical and chemical properties of interstitial water were investigated within a large gravel bar to determine if the parafluvial zone was a hotspot for nutrient transformations in a lowland eutrophic river, the Doubs (Eastern France). Interstitial water was sampled in 30 piezometers along five transects across the gravel bar, surface water was sampled in main and chute channels. Five campaigns of sampling were performed among summer and winter. In both interstitial and surface samples, water chemistry (electrical conductivity, pH, chloride, dissolved oxygen concentrations—DO) and nutrient concentrations (nitrate—NO3 −, ammonium—NH4 +, soluble reactive phosphorus—SRP, dissolved organic carbon—DOC) were measured. Moreover, temperature, water level, sediment grain size distribution and total bacterial abundance were assessed along a flowpath through a lateral gravel bar of the Doubs River. Measurements of water table elevation in the bar, main and chute channels indicated that the parafluvial flowpath was perpendicular to the main channel. Very low changes in chloride concentration and electrical conductivity showed minor groundwater input along the flowpath. The parafluvial zone was 0.9 m thick under the mean piezometric level, hydraulic gradients along the flowpath were 0.3%, and the discharge of interstitial water through the bar calculated at low flow was 40.6 m3 day−1. Most changes in interstitial nutrients occurred during the warm season, suggesting that biotic mechanisms occurred. Along the flowpath, DO, DOC, and bacterial abundance declined, while phosphate increased. Temporal trends of nitrate were less clear, exhibiting a slight increase during spring (organic matter biodegradation) and a decrease during summer (denitrification). Using the parafluvial discharge and nutrient concentrations of water infiltrating into and seeping from the gravel bar, the retention capacity of the bar was 171 gC day−1 for DOC and 48.3 gN day−1 for nitrate. Phosphate production ranged from 0.65 to 2.3 gP day−1. These values were low compared to the nutrient fluxes in the river Doubs, suggesting a minimal local impact of the parafluvial zone in regulating of river pollution.
[hal-00515772] Risk of complications after abdominal paracentesis in cirrhotic patients : a prospective study
13 octobre 2014
N/A
Do parafluvial zones have an impact in regulating river pollution? Spatial and temporal dynamics of nutrients, carbon, and bacteria in a large gravel bar of the Doubs River (France)
7 octobre 2014
The changes in both physical and chemical properties of interstitial water were investigated within a large gravel bar to determine if the parafluvial zone was a hotspot for nutrient transformations in a lowland eutrophic river, the Doubs (Eastern France). Interstitial water was sampled in 30 piezometers along five transects across the gravel bar, surface water was sampled in main and chute channels. Five campaigns of sampling were performed among summer and winter. In both interstitial and surface samples, water chemistry (electrical conductivity, pH, chloride, dissolved oxygen concentrations-DO) and nutrient concentrations (nitrate-NO3 (-), ammonium-NH4 (+), soluble reactive phosphorus-SRP, dissolved organic carbon-DOC) were measured. Moreover, temperature, water level, sediment grain size distribution and total bacterial abundance were assessed along a flowpath through a lateral gravel bar of the Doubs River. Measurements of water table elevation in the bar, main and chute channels indicated that the parafluvial flowpath was perpendicular to the main channel. Very low changes in chloride concentration and electrical conductivity showed minor groundwater input along the flowpath. The parafluvial zone was 0.9 m thick under the mean piezometric level, hydraulic gradients along the flowpath were 0.3%, and the discharge of interstitial water through the bar calculated at low flow was 40.6 m(3) day(-1). Most changes in interstitial nutrients occurred during the warm season, suggesting that biotic mechanisms occurred. Along the flowpath, DO, DOC, and bacterial abundance declined, while phosphate increased. Temporal trends of nitrate were less clear, exhibiting a slight increase during spring (organic matter biodegradation) and a decrease during summer (denitrification). Using the parafluvial discharge and nutrient concentrations of water infiltrating into and seeping from the gravel bar, the retention capacity of the bar was 171 gC day(-1) for DOC and 48.3 gN day(-1) for nitrate. Phosphate production ranged from 0.65 to 2.3 gP day(-1). These values were low compared to the nutrient fluxes in the river Doubs, suggesting a minimal local impact of the parafluvial zone in regulating of river pollution.
Sediment dynamic, channel morphology and ecological restoration downstream a dam : the case of the Ain river
23 septembre 2014
[halshs-00945594] Multidisciplinary approach to reconstructing local pastoral activities: an example from the Pyrenean Mountains (Pays Basque)
23 juin 2014
In this study archaeology, history and palaeoecology (modern and fossil data sets of pollen and nonpollen palynomorphs) were used to reconstruct small-scale pastoral activities in the Pyrenees Mountains during the last two millennia. Modern pollen assemblages from the major vegetation units (both natural andanthropogenic) are studied on one restricted watershed area. A correlative model (RDA) of 61 modern pollen spectra and 35 external variables distinguishes two groups of taxa, providing information on the nature and spatial extent of human impact on the landscape. The first pool indicates local pastoral activities, and the second one implies regional input from outside the studied watershed, and is not characteristic of a specific land use. These pools are described as 'Local Pastoral Pollen Indicators' (LPPI) for this particular mountain region on crystalline bedrock and 'Regional Human Activities Pollen Indicators' (RHAPI). The modern data set is used to aid interpretation of the local pollen sequence of Sourzay that covers the last 2000 calendar years BP, using RDA reconstructions, and best modern analogues as a means of comparing modern and fossil spectra. The study also demonstrates agreement between the independent interpretations of two fossil proxies, LPPI and coprophilous fungi.
[halshs-00955686] First steps in the modelling of Territorial Intelligence Community Systems
5 mars 2014
[...]
Multidisciplinary approach to reconstructing local pastoral activities: an example from the Pyrenean Mountains (Pays Basque)
12 février 2014
In this study archaeology, history and palaeoecology (modern and fossil data sets of pollen and nonpollen palynomorphs) were used to reconstruct small-scale pastoral activities in the Pyrenees Mountains during the last two millennia. Modern pollen assemblages from the major vegetation units (both natural andanthropogenic) are studied on one restricted watershed area. A correlative model (RDA) of 61 modern pollen spectra and 35 external variables distinguishes two groups of taxa, providing information on the nature and spatial extent of human impact on the landscape. The first pool indicates local pastoral activities, and the second one implies regional input from outside the studied watershed, and is not characteristic of a specific land use. These pools are described as 'Local Pastoral Pollen Indicators' (LPPI) for this particular mountain region on crystalline bedrock and 'Regional Human Activities Pollen Indicators' (RHAPI). The modern data set is used to aid interpretation of the local pollen sequence of Sourzay that covers the last 2000 calendar years BP, using RDA reconstructions, and best modern analogues as a means of comparing modern and fossil spectra. The study also demonstrates agreement between the independent interpretations of two fossil proxies, LPPI and coprophilous fungi.
[hal-00943341] Le Paléolithique supérieur ancien dans le quart nord-est de la France : l'exemple de la Franche-Comté. Environnement, chronologie et faciès culturels
7 février 2014
[...]
[halshs-00927128] The Transformation of Rural Structures in Southern Gaul between the 1st Century BC and the 1st Century AD. The Case of Eastern Languedoc
11 janvier 2014
[...]
[halshs-00470220] The transformation of rural structures in Southern Gaul between the first century BC and the first century AD. The case of eastern Languedoc (France)
24 août 2013
Romanization was a gradual and complex phenomenon. It is often investigated in urban settings where Roman power was ostentatious. Where the process has been examined in rural contexts, research has focused primarily on the most prominent production and land management facilities, such as villae or centuriations. More rarely is use made of the overall dynamics of the rural structures under study and of the system of settlement through which urban and rural areas interact in synergy. It is this last approach that is highlighted in this study. By examining settlement dynamics within a broad time frame, from the Iron Age to the 2nd century AD, this paper seeks to clarify how the Roman system of organization adapted to what was already a well organized indigenous set-up, by amplifying a dynamic that had been primed well before the conquest, probably by Phocaean commercial impetus. We attempt to show how the native population adopted and adapted certain Roman ways of doing things in order to control and develop their territory. Far from following on from one another, the two facets of the process interacted, making for a complex picture of Romanization and of its failures and successes.
[halshs-00847743] First steps in the modelling of Territorial Intelligence Community Systems
24 juillet 2013
[...]
[insu-00446344] Quantitative reconstruction of climatic variations during the Bronze and early Iron ages based on pollen and lake-level data in the NW Alps, France
3 mai 2013
Vegetation and lake-level data from the archaeological site of Tresserve, on the eastern shore of Lake Le Bourget (Savoie, France), are used to provide quantitative estimates of climatic variables over the period 4000-2300 cal BP in the northern French Pre-Alps, and to examine the possible impact of climatic changes on societies of the Bronze and early Iron Ages. The results obtained indicate that phases of higher lake level at 3500-3100 and 2750-2350 cal BP coincided with major climate reversals in the North Atlantic area. In west-central Europe, they were marked by cooler and wetter conditions. These two successive events may have affected ancient agricultural communities in west-central Europe by provoking harvest failures, more particularly due to increasing precipitation during the growing season. However, archaeological data in the region of Franche-Comté (Jura Mountains, eastern France) show a general expansion of population density from the middle Bronze Age to the early Iron Age. This suggests a relative emancipation of proto-historic societies from climatic conditions, probably in relation to the spread of new modes of social and economic organisation.
Quantitative reconstruction of climatic variations during the Bronze and early Iron ages based on pollen and lake-level data in the NW Alps, France
3 mai 2013
Vegetation and lake-level data from the archaeological site of Tresserve, on the eastern shore of Lake Le Bourget (Savoie, France), are used to provide quantitative estimates of climatic variables over the period 4000-2300 cal BP in the northern French Pre-Alps, and to examine the possible impact of climatic changes on societies of the Bronze and early Iron Ages. The results obtained indicate that phases of higher lake level at 3500-3100 and 2750-2350 cal BP coincided with major climate reversals in the North Atlantic area. In west-central Europe, they were marked by cooler and wetter conditions. These two successive events may have affected ancient agricultural communities in west-central Europe by provoking harvest failures, more particularly due to increasing precipitation during the growing season. However, archaeological data in the region of Franche-Comté (Jura Mountains, eastern France) show a general expansion of population density from the middle Bronze Age to the early Iron Age. This suggests a relative emancipation of proto-historic societies from climatic conditions, probably in relation to the spread of new modes of social and economic organisation.
[halshs-00819035] Topographie et fonctions religieuses sur l'oppidum de Bibracte et sa périphérie
29 avril 2013
[...]
[hal-00815891] Valeur de la rareté et collections d'animaux : quelles menaces sur les lucanes au Japon ?
19 avril 2013
[...]
Valeur de la rareté et collections d'animaux : quelles menaces sur les lucanes au Japon ?
19 avril 2013
[hal-00815631] The value of rarity : a new threat for animal of hobby collections ?
19 avril 2013
[...]
[hal-00412043] Radiofrequency exposure in the French general population: Band, time, location and activity variability.
20 mars 2013
Information on the exposure of individual persons to radiofrequency (RF) fields is scarce, although such data are crucial in order to develop a suitable exposure assessment method, and frame the hypothesis and design of future epidemiological studies. The main goal of this survey is to assess individual RF exposure on a population basis, while clarifying the relative contribution of different sources to the total exposure. A total of 377 randomly selected people were analyzed. Each participant was supplied with a personal exposure meter for 24-hour measurements (weekday), and kept a time-location-activity diary. Electric field strengths were recorded in 12 different RF bands every 13s. Summary statistics were calculated with the robust regression on order statistics method. Most of the time, recorded field strengths were not detectable with the exposure meter. Total field, cordless phones, WiFi-microwave, and FM transmitters stood apart with a proportion above the detection threshold of 46.6%, 17.2%, 14.1%, and 11.0%, respectively. The total field mean value was 0.201V/m, higher in urban areas, during daytime, among adults, and when moving. When focusing on specific channels, the highest mean exposure resulted from FM sources (0.044V/m), followed by WiFi-microwaves (0.038V/m), cordless phones (0.037V/m), and mobile phones (UMTS: 0.036V/m, UMTS: 0.037V/m). Various factors, however, contributed to a high variability in RF exposure assessment. These population-based estimates should therefore be confirmed by further surveys to better characterize the exposure situation in different microenvironments.
[hal-00432692] The New Caledonia Ophiolite: Multiple melting stages and refertilisation process as indicators for ridge to subduction formation.
24 janvier 2013
N/A
[hal-00764749] Utilisation de typologies territoriales dans l'étude des déterminants sociaux des hémopathies lymphoïdes, dans cinq départements français disposant d'un registre de cancer
17 décembre 2012
[...]
[halshs-00739408] Les moulins de type Pompéi en France
8 octobre 2012
Caractéristiques par leur forme et leurs dimensions, les meules de type Pompéi sont composées d'un catillus de grande taille en forme de coquetier ou de sablier et d'une meta conique. Ces pièces imposantes étaient mues par traction animale au moyen d'encoches aménagées de part et d'autre de la meule dans sa partie la plus étroite. La pente des surfaces actives est importante. Une récente étude a montré l'importance numérique de ce type de moulins dans la Gaule narbonnaise, alors que leur usage était préalablement considéré comme plutôt limité. Dans cette région, la totalité des éléments recensés sont en roche volcanique, très probablement originaire de la péninsule italienne et notamment de la région d'Orvieto. Ce matériau si caractéristique est connu principalement pour des meules de ce type, mais on trouve aussi dans la même roche des meules de grand format d'un autre type (meules hydrauliques ?) et quelques rares meules manuelles. Au-delà de la partie méridionale de la France, aucun recensement exhaustif de ce type d'outils de mouture n'a pour l'instant été mené. Plusieurs meules pompéiennes sont cependant connues à Amiens, Lyon, Paris, Troyes. Contrairement aux pièces originaires du sud de la France, toutes ne sont pas en roche volcanique. Elles ont essentiellement été découvertes lors de fouilles urbaines. Le but du présent travail est de dresser une première carte des meules de type Pompéi à l'échelle du territoire français. L'inventaire de ce type de meules prendra en compte la matière première, la datation et le contexte de chacune des pièces.
[hal-00480124] Lieux de culte dans l'Est de la Gaule : la place des sanctuaires dans la cité
27 mars 2012
N/A
[hal-00663222] Cysteine oxidation by the superoxide radical: a theoretical study
29 février 2012
The cysteine residue oxidation by the superoxide radical in the gas phase and in aqueous solution was studied using the integrated molecular orbital + molecular orbital (IMOMO) method combining the Quadratic Configuration Interaction (QCISD(T)) and density functional (DFT) methods. The molecular environment effects were systematically investigated by considering two alternative directions of attack of superoxide radical on the thiol and two different cysteine residue conformations. It was found that hydrogen bonding and the electrostatic interactions between the superoxide radical and cysteine side chaine significantly affect the reaction energy barrier, as compared to that derived for the simple thiol model methanethiol. Among the two possible reaction channels, that involving the sulfinyl radical formation is predicted to be the dominant channel in aqueous solution. In a highly hydrophobic environment the thiyl radical formation channel becomes the main cysteine oxidation channel.
[hal-00675004] Protein S-S bridges reduction: a Raman and computational study of lysozyme interaction with TCEP
28 février 2012
The role of protein structure in the reactivity of the four disulphide (S-S) bridges of lysozyme was studied using Raman spectroscopy and molecular modelling. The experimental kinetics of S-S bridges reduction by tris 2-carboxyethyl phosphine (TCEP) was obtained by monitoring the protein S-S Raman bands. The kinetics are heterogeneous and were fitted using two apparent reaction rate constants. Kinetic measurements performed at different pH values indicate only moderate charge effects. The two intrinsic reaction rate constants derived for the neutral TCEP species were 0.45 and 0.052 mol-1 s-1, respectively. The molecular dynamics simulation of the reactants encounter shows that the accesibility of the lysozyme S-S bridges by TCEP decreases in the following order: cys30-cys115 > cys6-cys127 > cys64-cys80 > cys76-cys94. This simulation also illustrates the reaction mechanism which consists in a local unfolding followed by the reduction of the exposed S-S bridge. The Gibbs free energy for local unfolding was evaluated by comparing the actual reaction rate constant with that of a model system containing a fully exposed S-S bridge (oxidized glutathione). These values corresponding to the fast and slow reaction rate constants were 8.5 and 13.8 kJ mol-1, respectively. On the other hand, Raman measurements as well as the molecular dynamics simulations strongly suggest that the protein global unfolding following S-S bridges cleavage has only limited effects in stabilizing the reaction products.
Protein S-S bridges reduction: a Raman and computational study of lysozyme interaction with TCEP
28 février 2012
The role of protein structure in the reactivity of the four disulphide (S-S) bridges of lysozyme was studied using Raman spectroscopy and molecular modelling. The experimental kinetics of S-S bridges reduction by tris 2-carboxyethyl phosphine (TCEP) was obtained by monitoring the protein S-S Raman bands. The kinetics are heterogeneous and were fitted using two apparent reaction rate constants. Kinetic measurements performed at different pH values indicate only moderate charge effects. The two intrinsic reaction rate constants derived for the neutral TCEP species were 0.45 and 0.052 mol-1 s-1, respectively. The molecular dynamics simulation of the reactants encounter shows that the accesibility of the lysozyme S-S bridges by TCEP decreases in the following order: cys30-cys115 > cys6-cys127 > cys64-cys80 > cys76-cys94. This simulation also illustrates the reaction mechanism which consists in a local unfolding followed by the reduction of the exposed S-S bridge. The Gibbs free energy for local unfolding was evaluated by comparing the actual reaction rate constant with that of a model system containing a fully exposed S-S bridge (oxidized glutathione). These values corresponding to the fast and slow reaction rate constants were 8.5 and 13.8 kJ mol-1, respectively. On the other hand, Raman measurements as well as the molecular dynamics simulations strongly suggest that the protein global unfolding following S-S bridges cleavage has only limited effects in stabilizing the reaction products.
[hal-00448435] Detection of a new extended-spectrum oxacillinase in Pseudomonas aeruginosa.
27 février 2012
N/A
[hal-00673360] Simulation des échanges thermiques dans une enceinte expérimentale dédiée à l'étude de la fiabilité des matériaux fonctionnels. (poster)
23 février 2012
[...]
[halshs-00670538] Grüne Schätze vom heiligen Berg : Steinbeile aus Jade im Kyffhäuserkreis
15 février 2012
[...]
[halshs-00670535] Ein herausragendes neolithisches Jadebeil aus Hiddenhausen-Bermbeck
15 février 2012
[...]
[hal-00670089] La circulation monétaire dans l'Avallonnais durant l'Antiquité, apports du médaillier du musée de l'Avallonnais et des découvertes récentes
14 février 2012
[...]
[hal-00670088] De la ferme au palais. Les établissements ruraux antiques de Bourgogne du nord, IIè-IVè siècles p.C.
14 février 2012
N/A
[hal-00670079] L'occupation laténienne du sanctuaire des " Champs des Fougères "à Mandeure (Doubs). Campagnes 2007 et 2008
14 février 2012
[...]
De la ferme au palais. Les établissements ruraux antiques de Bourgogne du nord, IIè-IVè siècles p.C.
14 février 2012
L'occupation laténienne du sanctuaire des " Champs des Fougères "à Mandeure (Doubs). Campagnes 2007 et 2008
14 février 2012
Experimental investigation of the Cs2 a 3Sigma(u)+ triplet ground state: multiparameter Morse long range potential analysis and molecular constants.
7 février 2012
We have observed the vibrational levels v(") = 0-40 of the Cs(2) a (3)Sigma(u)(+) state by perturbation facilitated infrared-infrared double resonance excitation and spectrally resolved fluorescence measurements, and derived a multiparameter Morse long range potential and molecular constants based on these data.
Cysteine oxidation by the superoxide radical: a theoretical study
26 janvier 2012
The cysteine residue oxidation by the superoxide radical in the gas phase and in aqueous solution was studied using the integrated molecular orbital + molecular orbital (IMOMO) method combining the Quadratic Configuration Interaction (QCISD(T)) and density functional (DFT) methods. The molecular environment effects were systematically investigated by considering two alternative directions of attack of superoxide radical on the thiol and two different cysteine residue conformations. It was found that hydrogen bonding and the electrostatic interactions between the superoxide radical and cysteine side chaine significantly affect the reaction energy barrier, as compared to that derived for the simple thiol model methanethiol. Among the two possible reaction channels, that involving the sulfinyl radical formation is predicted to be the dominant channel in aqueous solution. In a highly hydrophobic environment the thiyl radical formation channel becomes the main cysteine oxidation channel.
[hal-00662258] Silicon-Micromachined Gas Chromatographic Columns for the Development of Portable Detection Device
23 janvier 2012
We report the fabrication of a gas chromatographic column module integrated on a silicon substrate and usable as a portable measurement device dedicated to the selective detection of various chemical compounds (gas or vapour). PDMS, PEG, and F13- TEOS stationary phases have been prepared in order to coat the inside walls of microchannels. The microcolumn tests were performed with a mixture of hydrocarbons and ketone. After having evaluated the effectiveness of such a separation module, we showed an application by coupling a GC microcolumn with a metal oxide-based gas sensor. The best results were obtained at a low isothermal temperature mode of the GC micro-column (near the ambient temperature). The coupling between the GC microcolumn and ametal oxide gas sensor enables to obtain a rapid, reliable, and selective analysis of various chemical compounds.
[hal-00662251] Towards a hybrid micro-device allowing the selective detection of hydrogen fluoride vapours in a complex mixture
23 janvier 2012
In thiswork, design and fabrication of a hybrid micro-device dedicated to the selective detection of hydrogen fluoride vapours is reported. This micro-device is composed by a gas chromatographic micro-column positioned in front of a tin dioxide-based gas sensor. The efficiency of this hybrid micro-system regarding to reproducibility and reversibility for various HF concentrations was investigated. The influence of the HF concentration on the electrical responses of the sensor is also studied. The experimental results show that this hybrid micro-system is efficient since it allows the elution, separation and detection of hydrogen fluoride at a low temperature close to ambient.
[hal-00662235] Detection of hydrogen fluoride using SnO2-based gas sensors : Understanding of the reactional mechanism
23 janvier 2012
Tin dioxide-based gas sensors are very efficient devices for the detection of hydrogen fluoride in trace levels since amounts lower than 50 ppb can be detected. Considering the working temperatures of tin dioxide-based gas sensors which are included between 25 and 500 ◦C, the best sensitivity was obtained when the sensor's temperature was maintained at 380 ◦C. In order to explain why high sensitivity is obtained for this temperature and then to understand the reactional mechanism between HF molecules and tin dioxide surfaces, X-ray photoelectron spectroscopy investigations were performed on tin dioxide samples treated with HF vapors at temperatures ranging from 200 to 500 ◦C. For this temperature range, the comparison between the electrical response curves and the XPS characterization, led to the consideration of two separate temperature ranges, where the interaction mechanism between HF and SnO2 can be explained. For temperature lower than 380 ◦C, the adsorption of HF induces the formation of surface hydroxyl groups and SnF4 species. In that case, the electrical conductance of the sensitive material gradually increases. Beyond this temperature, water vapors desorb from tin dioxide surfaces and then the electrical conductance is lowered. Finally, for both ranges of temperatures, the interaction mechanism occurring at the gas/detector interface is proposed.
Silicon-Micromachined Gas Chromatographic Columns for the Development of Portable Detection Device
23 janvier 2012
We report the fabrication of a gas chromatographic column module integrated on a silicon substrate and usable as a portable measurement device dedicated to the selective detection of various chemical compounds (gas or vapour). PDMS, PEG, and F13- TEOS stationary phases have been prepared in order to coat the inside walls of microchannels. The microcolumn tests were performed with a mixture of hydrocarbons and ketone. After having evaluated the effectiveness of such a separation module, we showed an application by coupling a GC microcolumn with a metal oxide-based gas sensor. The best results were obtained at a low isothermal temperature mode of the GC micro-column (near the ambient temperature). The coupling between the GC microcolumn and ametal oxide gas sensor enables to obtain a rapid, reliable, and selective analysis of various chemical compounds.
Towards a hybrid micro-device allowing the selective detection of hydrogen fluoride vapours in a complex mixture
23 janvier 2012
In thiswork, design and fabrication of a hybrid micro-device dedicated to the selective detection of hydrogen fluoride vapours is reported. This micro-device is composed by a gas chromatographic micro-column positioned in front of a tin dioxide-based gas sensor. The efficiency of this hybrid micro-system regarding to reproducibility and reversibility for various HF concentrations was investigated. The influence of the HF concentration on the electrical responses of the sensor is also studied. The experimental results show that this hybrid micro-system is efficient since it allows the elution, separation and detection of hydrogen fluoride at a low temperature close to ambient.
Detection of hydrogen fluoride using SnO2-based gas sensors : Understanding of the reactional mechanism
23 janvier 2012
Tin dioxide-based gas sensors are very efficient devices for the detection of hydrogen fluoride in trace levels since amounts lower than 50 ppb can be detected. Considering the working temperatures of tin dioxide-based gas sensors which are included between 25 and 500 ◦C, the best sensitivity was obtained when the sensor's temperature was maintained at 380 ◦C. In order to explain why high sensitivity is obtained for this temperature and then to understand the reactional mechanism between HF molecules and tin dioxide surfaces, X-ray photoelectron spectroscopy investigations were performed on tin dioxide samples treated with HF vapors at temperatures ranging from 200 to 500 ◦C. For this temperature range, the comparison between the electrical response curves and the XPS characterization, led to the consideration of two separate temperature ranges, where the interaction mechanism between HF and SnO2 can be explained. For temperature lower than 380 ◦C, the adsorption of HF induces the formation of surface hydroxyl groups and SnF4 species. In that case, the electrical conductance of the sensitive material gradually increases. Beyond this temperature, water vapors desorb from tin dioxide surfaces and then the electrical conductance is lowered. Finally, for both ranges of temperatures, the interaction mechanism occurring at the gas/detector interface is proposed.
[halshs-00612050] Le contexte des découvertes, la perception de la chronologie, les attributions culturelles
28 juillet 2011
[...]
Le contexte des découvertes, la perception de la chronologie, les attributions culturelles
28 juillet 2011
Le contexte des découvertes, la perception de la chronologie, les attributions culturelles
28 juillet 2011
[insu-00577773] P/T ratio in high-pressure rocks as a function of dip and velocity of continental subduction
17 mars 2011
[...]
P/T ratio in high-pressure rocks as a function of dip and velocity of continental subduction
17 mars 2011
P/T ratio in high-pressure rocks as a function of dip and velocity of continental subduction
17 mars 2011
[insu-00576000] Quantification of cationic exchanges in the Upper Rhine valley potash basin: Coupled geochemical and modeling approach.
11 mars 2011
N/A
[hal-00565295] Surface Acoustic Wave Resonators as Passive Buried Sensors
11 février 2011
Acoustic wave devices are well known passive transducers for probing through a wireless link a physical quantity. Amongst the two main classes of designs - resonators and delay lines - the former have the advantage of providing informations in a narrow band signal and are hence compatible with an interrogation strategy compliant with radiofrequency (RF) emission regulations, while the latter are probed by a short RF pulse with larger instantaneous energy and shorter response time. We here demonstrate the measurement of temperature using the two configurations, and more specifically for sensors buried in soil. While we demonstrate long term stability and ruggedness of packaged resonators, and signal to noise ratio compatible with the envisioned application, the interrogation range in insufficient for most purposes and we focus towards the use of delay lines. Indeed, the interrogation method of the latter is similar to that used by ground penetrating RADAR (GPR) which displays interrogation ranges in the meter to tens of meters in the lower RF range, depending on soil water content, permittivity and conductivity.
Surface Acoustic Wave Resonators as Passive Buried Sensors
11 février 2011
Acoustic wave devices are well known passive transducers for probing through a wireless link a physical quantity. Amongst the two main classes of designs - resonators and delay lines - the former have the advantage of providing informations in a narrow band signal and are hence compatible with an interrogation strategy compliant with radiofrequency (RF) emission regulations, while the latter are probed by a short RF pulse with larger instantaneous energy and shorter response time. We here demonstrate the measurement of temperature using the two configurations, and more specifically for sensors buried in soil. While we demonstrate long term stability and ruggedness of packaged resonators, and signal to noise ratio compatible with the envisioned application, the interrogation range in insufficient for most purposes and we focus towards the use of delay lines. Indeed, the interrogation method of the latter is similar to that used by ground penetrating RADAR (GPR) which displays interrogation ranges in the meter to tens of meters in the lower RF range, depending on soil water content, permittivity and conductivity.
Surface Acoustic Wave Resonators as Passive Buried Sensors
11 février 2011
Acoustic wave devices are well known passive transducers for probing through a wireless link a physical quantity. Amongst the two main classes of designs - resonators and delay lines - the former have the advantage of providing informations in a narrow band signal and are hence compatible with an interrogation strategy compliant with radiofrequency (RF) emission regulations, while the latter are probed by a short RF pulse with larger instantaneous energy and shorter response time. We here demonstrate the measurement of temperature using the two configurations, and more specifically for sensors buried in soil. While we demonstrate long term stability and ruggedness of packaged resonators, and signal to noise ratio compatible with the envisioned application, the interrogation range in insufficient for most purposes and we focus towards the use of delay lines. Indeed, the interrogation method of the latter is similar to that used by ground penetrating RADAR (GPR) which displays interrogation ranges in the meter to tens of meters in the lower RF range, depending on soil water content, permittivity and conductivity.
[halshs-00552850] Apports de la micromorphologie des sols à l'interprétation de trois séquences pédo-sédimentaires lorraines fossiles bien datées
13 janvier 2011
N/A
[hal-00465391] [Clinical audit on the use of expensive systemic antifungals in the Besançon University Hospital]
16 décembre 2010
The continuous improvement policy for healthcare quality requires practice evaluation. The principle of a clinical audit is to compare practice to guidelines. Prescription guidelines on antifungal agent use has been available in our hospital since 2003. It was updated in 2005 and 2006. OBJECTIVE: The aim of this study was to assess compliance to guidelines, with an audit of prescriptions: amphotericin B lipid formulation, voriconazole and caspofungin, expensive antifungals concerned by the budget allowance correlated to activity, subject to supplementary reimbursement to the coded Homogeneous Group of Diseases. METHOD: The assessment criteria were: relevance of the indication, absence of a better alternative, complying to recommended dosage, loading dose and timing. This retrospective study dealt with all prescriptions of all departments, from January to May 2007. RESULTS: Hundred and eighteen prescriptions were retrospectively analyzed for 81 patients. The rate of overall conformity was 54%. Antifungal therapy was justified for 113 prescriptions (96%). In 30% of the cases, a more efficient alternative was advised, cheaper or less toxic. The dosage and the charge dosing were right in 92% and 80% of the cases respectively. CONCLUSION: This audit allowed assessing good-use of antifungals. We showed an over-prescription of caspofungin and sometimes insufficient regimen of voriconazole dosages for children. Reporting these audit results and development of new international guidelines stress the need to update local recommendations regularly.
Communities structure of the planktonic halophiles in the solar saltern of Sfax, Tunisia
14 octobre 2010
The composition and distribution of the main planktonic halophilic micro-organisms (heterotrophic and autotrophic picoplankton, nanoplankton, phytoplankton, ciliates) and metazooplankton were investigated in six ponds of increasing salinity in the solar salt works of Sfax, Tunisia, from January to December 2003. Marked changes in the composition and biomass of the communities were found along the salinity gradient, especially at salinities of 150 and 350. Autotrophic picoplankton, nanoplankton, diatoms, dinoflagellates and ciliates characterized the less salted ponds. Planktonic biomass was the highest at intermediate salinity as a consequence of a bloom of Ochromonas. Species richness of phytoplankton, ciliates and zooplankton greatly decrease above a salinity of 150 and typical halophiles (Dunaliella salina, cyanobacteria, Fabrea salina and Artemia salina) were found between 150 and 350 salinity. In this environment, F. salina appeared more adapted than the brine shrimp to survive during phytoplankton blooms. The halophilic plankton was however almost entirely composed of heterotrophic prokaryotes in the crystallizers. We thus observed a progressive disappearance of the autotrophic planktonic communities along the salinity gradient. Multivariate analysis of the communities provides evidence that ponds represent discrete aquatic ecosystems within this salt works.
Communities structure of the planktonic halophiles in the solar saltern of Sfax, Tunisia
14 octobre 2010
The composition and distribution of the main planktonic halophilic micro-organisms (heterotrophic and autotrophic picoplankton, nanoplankton, phytoplankton, ciliates) and metazooplankton were investigated in six ponds of increasing salinity in the solar salt works of Sfax, Tunisia, from January to December 2003. Marked changes in the composition and biomass of the communities were found along the salinity gradient, especially at salinities of 150 and 350. Autotrophic picoplankton, nanoplankton, diatoms, dinoflagellates and ciliates characterized the less salted ponds. Planktonic biomass was the highest at intermediate salinity as a consequence of a bloom of Ochromonas. Species richness of phytoplankton, ciliates and zooplankton greatly decrease above a salinity of 150 and typical halophiles (Dunaliella salina, cyanobacteria, Fabrea salina and Artemia salina) were found between 150 and 350 salinity. In this environment, F. salina appeared more adapted than the brine shrimp to survive during phytoplankton blooms. The halophilic plankton was however almost entirely composed of heterotrophic prokaryotes in the crystallizers. We thus observed a progressive disappearance of the autotrophic planktonic communities along the salinity gradient. Multivariate analysis of the communities provides evidence that ponds represent discrete aquatic ecosystems within this salt works.
Jasmonate controls late development stages of petal growth in Arabidopsis thaliana.
28 septembre 2010
Jasmonate controls late development stages of petal growth in Arabidopsis thaliana.
28 septembre 2010
Nitrate Contamination of Groundwater in Irrigated Perimeters under Arid Climate (The Case of Souss-Massa Aquifer, Morocco)
9 septembre 2010
The objective of this study was to clarify, the current status of alluvial aquifer in the Souss-Massa basin, where, the nitric pollution of groundwater is being increasing along the last decades. A multi-approach methodology using hydrogeology, nitrate concentrations, irrigation mode and Oxygen-18 and Deuterium isotopes data, was carried out to identify the sources of this pollution. According to the spatial distribution of nitrate contents, nitric pollution occurs mainly in the Chtouka-Massa plain. More than 36% of the sampled wells exceed the value of 50 mg L-1 which, constitutes the threshold value of nitrate concentrations for drinking water Moroccan standards. The groundwater in Souss plain is less polluted comparing to Chtouka-Massa. Only 7% of wells exceed the permitted level. The widespread distribution of high nitrate contents agrees with the distribution of irrigated areas, which can explain the major origin from agricultural fertilizers. High nitrate levels are associated with high δ18O values, clearly indicating that significant quantities of evaporated (isotopically enriched) irrigation water infiltrate along with fertilizer nitrate to the groundwater system. Different δ18O-NO3- trends suggest isotopically distinct, non-point source origins, which vary spatially and temporally, due to different degrees of evaporation/recharge and amounts of fertilizer applied.
Nitrate Contamination of Groundwater in Irrigated Perimeters under Arid Climate (The Case of Souss-Massa Aquifer, Morocco)
9 septembre 2010
The objective of this study was to clarify, the current status of alluvial aquifer in the Souss-Massa basin, where, the nitric pollution of groundwater is being increasing along the last decades. A multi-approach methodology using hydrogeology, nitrate concentrations, irrigation mode and Oxygen-18 and Deuterium isotopes data, was carried out to identify the sources of this pollution. According to the spatial distribution of nitrate contents, nitric pollution occurs mainly in the Chtouka-Massa plain. More than 36% of the sampled wells exceed the value of 50 mg L-1 which, constitutes the threshold value of nitrate concentrations for drinking water Moroccan standards. The groundwater in Souss plain is less polluted comparing to Chtouka-Massa. Only 7% of wells exceed the permitted level. The widespread distribution of high nitrate contents agrees with the distribution of irrigated areas, which can explain the major origin from agricultural fertilizers. High nitrate levels are associated with high δ18O values, clearly indicating that significant quantities of evaporated (isotopically enriched) irrigation water infiltrate along with fertilizer nitrate to the groundwater system. Different δ18O-NO3- trends suggest isotopically distinct, non-point source origins, which vary spatially and temporally, due to different degrees of evaporation/recharge and amounts of fertilizer applied.
Tritium in plants: A review of current knowledge
8 septembre 2010
The aim of this paper is to provide an overview of the literature regarding the fate of tritium in plants. At first, some prerequisites about the sources, chemical and physical characteristics, biological effects and potential risks associated to tritium are presented. The general scheme of tritium transport and cycling in the environment, the different tritium fractions in biological organisms and the corresponding techniques for sampling and measurement are discussed. Then, the main processes of uptake, incorporation and conversion of tritium into plants are described, based on experimental data. As tritium incorporated into the organic fraction may be the major contributor to the dose of radiation received following its ingestion by man, the biological mechanisms and kinetics of organically bound tritium (OBT) production are a major focus. Some predictive models of short-term or chronic exposure are described. Finally, the pending questions, concerning the fate of tritium in plants, are tackled.
Tritium in plants: A review of current knowledge
8 septembre 2010
The aim of this paper is to provide an overview of the literature regarding the fate of tritium in plants. At first, some prerequisites about the sources, chemical and physical characteristics, biological effects and potential risks associated to tritium are presented. The general scheme of tritium transport and cycling in the environment, the different tritium fractions in biological organisms and the corresponding techniques for sampling and measurement are discussed. Then, the main processes of uptake, incorporation and conversion of tritium into plants are described, based on experimental data. As tritium incorporated into the organic fraction may be the major contributor to the dose of radiation received following its ingestion by man, the biological mechanisms and kinetics of organically bound tritium (OBT) production are a major focus. Some predictive models of short-term or chronic exposure are described. Finally, the pending questions, concerning the fate of tritium in plants, are tackled.
Risk of complications after abdominal paracentesis in cirrhotic patients : a prospective study
7 septembre 2010
Risk of complications after abdominal paracentesis in cirrhotic patients : a prospective study
7 septembre 2010
Habitats, terroirs et territoire dans le Languedoc oriental durant l'Antiquité. Approche spatiotemporelle d'un système de peuplement
1er septembre 2010
Habitats, terroirs et territoire dans le Languedoc oriental durant l'Antiquité. Approche spatiotemporelle d'un système de peuplement
1er septembre 2010
Numerical and dietary responses of a predator community in a temperate zone of Europe
27 août 2010
The generalist predation hypothesis predicts that the functional responses of generalist predator species should be quicker than those of specialist predators and have a regulating effect on vole populations. New interpretations of their role in temperate ecosystems have, however, reactivated a debate suggesting generalist predators may have a destabilizing effect under certain conditions (e.g. landscape homogeneity, low prey diversity, temporary dominance of 1 prey species associated with a high degree of dietary specialization). We studied a rich predator community dominated by generalist carnivores (Martes spp., Vulpes vulpes, Felis catus) over a 6 yr period in farmland and woodland in France. The most frequent prey were small rodents (mostly Microtus arvalis, a grassland species, and Apodemus spp., a woodland species). Alternative prey were diverse and dominated by lagomorphs (Oryctolagus cuniculus, Lepus europeus). We detected a numerical response among specialist carnivores but not among generalist predators. The dietary responses of generalist predators were fairly complex and most often dependent on variation in density of at least 1 prey species. These results support the generalist predation hypothesis. We document a switch to alternative prey, an increase of diet diversity, and a decrease of diet overlap between small and medium-sized generalists during the low density phase of M. arvalis. In this ecosystem, the high density phases of small mammal species are synchronous and cause a temporary specializing of several generalist predator species. This rapid functional response may indicate the predominant role of generalists in low amplitude population cycles of voles observed in some temperate areas.
Numerical and dietary responses of a predator community in a temperate zone of Europe
27 août 2010
The generalist predation hypothesis predicts that the functional responses of generalist predator species should be quicker than those of specialist predators and have a regulating effect on vole populations. New interpretations of their role in temperate ecosystems have, however, reactivated a debate suggesting generalist predators may have a destabilizing effect under certain conditions (e.g. landscape homogeneity, low prey diversity, temporary dominance of 1 prey species associated with a high degree of dietary specialization). We studied a rich predator community dominated by generalist carnivores (Martes spp., Vulpes vulpes, Felis catus) over a 6 yr period in farmland and woodland in France. The most frequent prey were small rodents (mostly Microtus arvalis, a grassland species, and Apodemus spp., a woodland species). Alternative prey were diverse and dominated by lagomorphs (Oryctolagus cuniculus, Lepus europeus). We detected a numerical response among specialist carnivores but not among generalist predators. The dietary responses of generalist predators were fairly complex and most often dependent on variation in density of at least 1 prey species. These results support the generalist predation hypothesis. We document a switch to alternative prey, an increase of diet diversity, and a decrease of diet overlap between small and medium-sized generalists during the low density phase of M. arvalis. In this ecosystem, the high density phases of small mammal species are synchronous and cause a temporary specializing of several generalist predator species. This rapid functional response may indicate the predominant role of generalists in low amplitude population cycles of voles observed in some temperate areas.
Emergence of extensive-drug-resistant Pseudomonas aeruginosa in a French university hospital.
19 août 2010
Emergence of extensive-drug-resistant Pseudomonas aeruginosa in a French university hospital.
19 août 2010
[hal-00504971] Identifications de levures et antifongigrammes : comparaison entre la méthode manuelle et le Vitek 2
22 juillet 2010
N/A
Identifications de levures et antifongigrammes : comparaison entre la méthode manuelle et le Vitek 2
22 juillet 2010
Identifications de levures et antifongigrammes : comparaison entre la méthode manuelle et le Vitek 2
22 juillet 2010
[hal-00488014] Digestive cryptosporidiosis mimics GVHD after Hematopoietic Stem Cell Transplantation and responds to bi-antibiotic therapy
21 juillet 2010
N/A
[hal-00465942] Misidentification of the emerging pathogenic yeasts Candida nivariensis as Zygosaccharamyces sp.
21 juillet 2010
N/A
[hal-00466198] Maxillary sinus fungus ball due to Rhizomucor pusillus : an uncommun clinical presentation of mucormycosis
21 juillet 2010
N/A
Microbiological and epidemiological features of clinical respiratory isolates of Burkholderia gladioli.
30 juin 2010
Microbiological and epidemiological features of clinical respiratory isolates of Burkholderia gladioli.
30 juin 2010
[halshs-00476188] Une production du Mont Viso en Italie : l'ébauche de haches de Lugrin (Haute-Savoie, France)
8 juin 2010
Production de haches néolithiques par sciage
[halshs-00476187] L'Unique, la Paire, les Multiples. A propos des dépôts de haches polies en roches alpines en Europe occidentale pendant les Ve et IVe millénaires
8 juin 2010
Signification sociale des grandes haches néolithiques en jades alpins
Hydraulic interactions between fractures and bedding planes in a carbonate aquifer studied by means of experimentally induced water-table fluctuations (Coaraze experimental site, southeastern France)
2 juin 2010
In aquifers with variable permeability, the water exchanges between high and low permeability regions are controlled by the hydraulic head gradient. Past studies have addressed this problem mainly considering steadystate hydraulic conditions. To study such exchanges during water-table fluctuations, a spring was equipped with a water-gate that creates 10-meter artificial fluctuations of the water table. The water exchanges are discussed with respect to hydrochemical and pressure measurements in the groundwater. With successive water-table fluctuations the mineralization and pH decrease, but the bicarbonate content increases in response to carbon dioxide dissolution . At this scale of single fractures and surroundings, the hydrochemistry allows water flows from low or high permeability discontinuities to be discriminated. During hydraulic head fluctuations, the waters from low and high permeability discontinuities become mixed. During water-table rise, the low-permeability matrix contributed to the refilling of the permeable faults and to the mixing of the waters. Dynamic flows in the opposite direction to the hydraulic gradient can expel mineralized water, pushing it towards permeable discontinuities. This mechanism could be the cause of the peak in the mineralisation recorded in some karst springs at the start of flood events.
Mechanical decoupling of high-pressure crustal units during continental subduction.
2 juin 2010
The mechanics of the transition from continental subduction toward upper crustal nappe stacking is still poorly understood and is studied here through a 2D thermal and strength numerical modelling of a subducted passive margin. Geological observations in the core of most mountain belts show the piling up of several HP-LT upper crustal units that are most likely related to the detachment of upper crustal units from the subducted continental margin and to the subsequent stacking of the detached units at depths. The Adula unit (Lepontine dome, Central Alps, Switzerland) is a long and thin upper crustal unit and is used here as a natural case-study as it provides a well-documented example of these units. 2D thermal modeling shows that two steps, successive in time, characterized the burial history of the passive margin undergoing continental subduction: 1-an increase in the margin strength due to an increase in the confining pressure during the first million years of the margin subduction and 2-the progressive heating of the subducted margin from the overlying lithosphere leads to a decrease in the margin strength due to thermal weakening, which progressively counter-balances the increase in confining pressure. Two strength gradients develop within the subducted lithosphere: 1-along the slab, the strength decreases with increasing burial depth and 2-perpendicular to the slab, the strength increases with depth due to an inverse temperature distribution. The detachment of HP-LT continental units from the subducted margin could occur when the slab strength becomes lower than the applied net stress. This allows the detachment of ductile weakened thin and long upper-crustal units. The thickness and length of the detached crustal units are controlled by the following parameters, in order of their importance: subduction dip angle, crustal rheology, mantle heat flux and subduction velocity. The comparison of our model results with the geometry and PT conditions of the Adula unit yields an estimate of the Alpine subduction dip angle at the time of deformation and metamorphism.
[hal-00462066] La grotte du Gardon (Ain)
2 juin 2010
La grotte du Gardon à Ambérieu-en-Bugey (Ain), au sud du Jura, a fait l'objet, durant plus de quinze années, d'une importante fouille programmée afin d'établir une nouvelle séquence chrono-culturelle de référence pour la Préhistoire récente du haut Bassin rhodanien. Ce volume constitue le premier volet d'une trilogie présentant les résultats de ces recherches qui documentent les occupations humaines depuis la fin du sixième millénaire jusqu'au XVIIe siècle de notre ère. La première partie de l'ouvrage présente le gisement dans son contexte géographique et géologique, les résultats des fouilles anciennes, la stratigraphie, les datations absolues et les facteurs de remplissage. Il est notamment possible de mettre en évidence une alternance de couches d'occupation et de niveaux d'inondation du trop-plein karstique, en lien avec les variations paléo-climatiques reconnues dans le Jura. La seconde partie traite de l'environnement du gisement, qu'il soit archéologique ou naturel (anthracologie, carpologie, paléoenvironnement, microfaune, ressources lithiques). En dernier lieu est abordée la question de la néolithisation de cette région par la présentation des couches 60 à 47. Durant le Néolithique ancien, entre 5300 et 4800 avant notre ère, la grotte est occupée à plusieurs reprises, soit par des éleveurs d'origine méridionale, soit par des chasseurs autochtones dont les pratiques renvoient pour l'essentiel aux traditions mésolithiques locales. Le début du Néolithique moyen, entre 4700 et 4250 avant notre ère, correspond à des occupations semi-permanentes (habitats ou bergeries). Ces niveaux, riches en matériaux archéologiques, ont contribuéà la définition des ensembles culturels de cette période, et notamment du style de Saint-Uze.
[hal-00452439] Nosocomial transmission of hepatitis B from an infected healthcare worker to a patient, France, 2005
28 mai 2010
In 2005, following seroconversion by hepatitis B virus in a patient who underwent surgery, an investigation was carried out to identify the origin of the contamination. Evidence collected through this investigation strongly suggests a likely nosocomial transmission from a healthcare worker to a patient. An observational workplace practice review disclosed a certain number of malfunctions that could have played a role in the transmission, even if the exact route of transmission could not be established retrospectively. This case report underlines the importance of standard precautions and good practices of care.
Distribution of ciliates in relation to environmental factors along the coastline of the Gulf of Gabes, Tunisia
22 mai 2010
We studied the seasonal distribution of the ciliate community coupled with environmental factors along the coast at three stations sampled (from March 2006 to February 2007) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 56 species belonging to 11 orders, were identified. Harbor of Gabes station was more diversified (45 species) than both Tabia (26 species) and Karboub (31 species) stations. The ciliate assemblage was numerically dominated by Spirotrichea in Tabia (82% of the total abundance), in the Harbor of Gabes (86% of the total abundance), whereas, in Karboub, Spirotrichea represented only 40% of the total abundance. The unexpected lower quantitative importance of Spirotrichea in Karboub station was apparently the result of the high salt concentration found in water samples throughout the study, probably originating from the saline area surrounding Karboub station, known as Sabkha. The distribution of species in the nearshore of the Gulf of Gabes seemed most likely influenced by the combined effects of temperature, salinity and hydrographic conditions.
Distribution of ciliates in relation to environmental factors along the coastline of the Gulf of Gabes, Tunisia
22 mai 2010
We studied the seasonal distribution of the ciliate community coupled with environmental factors along the coast at three stations sampled (from March 2006 to February 2007) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 56 species belonging to 11 orders, were identified. Harbor of Gabes station was more diversified (45 species) than both Tabia (26 species) and Karboub (31 species) stations. The ciliate assemblage was numerically dominated by Spirotrichea in Tabia (82% of the total abundance), in the Harbor of Gabes (86% of the total abundance), whereas, in Karboub, Spirotrichea represented only 40% of the total abundance. The unexpected lower quantitative importance of Spirotrichea in Karboub station was apparently the result of the high salt concentration found in water samples throughout the study, probably originating from the saline area surrounding Karboub station, known as Sabkha. The distribution of species in the nearshore of the Gulf of Gabes seemed most likely influenced by the combined effects of temperature, salinity and hydrographic conditions.
Phytoplankton-pigment signatures and their relationship to spring–summer stratification in the Gulf of Gabes
22 mai 2010
We investigated the phytoplankton dynamics (determined by CHEMTAX analysis of HPLC pigment data) and its relationships with nutrients and water column structure, during two oceanographic cruises in May–June and September 2006 in the Gulf of Gabes (south-eastern Mediterranean). The May–June cruise coincided with the beginning of the summer stratification, while a strong stratification occurred in September with a more than 30 m deepening of the thermocline, and a reduction of the euphotic depth. This strong stratification resulted in a shift in nitrogen sources from nitrates to ammonium as well as phosphate depletion (0.2 mM) and a decrease in silicate concentrations (<2 mM). With the exception of chlorophyll a, pigment concentrations were higher in September than in May–June samplings. The picoand nanophytoplankton were the major contributors to phytoplankton total biomass, accounting for 90% and 87% of total chlorophyll a in May–June and September, respectively. Picoplankton persisted throughout the entire survey, occupying different depth layers. Chlorophytes were present at substantial amounts (average 23% of total chlorophyll a) during May–June; however, they declined in September (average 5%). Diatoms were overall poorly represented in this study (2% of total chlorophyll a), due probably to silicate shortage. Apparently, the nutrient availability, but also the water column stability seemed to be among the major factors determining phytoplankton dynamics. Indeed, cyanobacteria were prominent in surface samples during the period of strong stratification, whereas the relative contribution of chlorophytes decreased, probably due to low phosphate availability.
Phytoplankton-pigment signatures and their relationship to spring–summer stratification in the Gulf of Gabes
22 mai 2010
We investigated the phytoplankton dynamics (determined by CHEMTAX analysis of HPLC pigment data) and its relationships with nutrients and water column structure, during two oceanographic cruises in May–June and September 2006 in the Gulf of Gabes (south-eastern Mediterranean). The May–June cruise coincided with the beginning of the summer stratification, while a strong stratification occurred in September with a more than 30 m deepening of the thermocline, and a reduction of the euphotic depth. This strong stratification resulted in a shift in nitrogen sources from nitrates to ammonium as well as phosphate depletion (0.2 mM) and a decrease in silicate concentrations (<2 mM). With the exception of chlorophyll a, pigment concentrations were higher in September than in May–June samplings. The picoand nanophytoplankton were the major contributors to phytoplankton total biomass, accounting for 90% and 87% of total chlorophyll a in May–June and September, respectively. Picoplankton persisted throughout the entire survey, occupying different depth layers. Chlorophytes were present at substantial amounts (average 23% of total chlorophyll a) during May–June; however, they declined in September (average 5%). Diatoms were overall poorly represented in this study (2% of total chlorophyll a), due probably to silicate shortage. Apparently, the nutrient availability, but also the water column stability seemed to be among the major factors determining phytoplankton dynamics. Indeed, cyanobacteria were prominent in surface samples during the period of strong stratification, whereas the relative contribution of chlorophytes decreased, probably due to low phosphate availability.
Phytoplankton dynamics related to water mass properties in the Gulf of Gabes: Ecological implications
22 mai 2010
The spatial distribution of chlorophylls and carotenoids was recorded throughout the Gulf of Gabes (South Ionian Sea) in March 2007, and was related to patterns of the physical structure and the nutrient concentrations. Two distinctwater masseswere identified based on the temperature and salinity (T–S) analysis: a cool and less salty Modified Atlantic Water (MAW) and a saltier Mediterranean Mixed Water (MMW). There was no significant difference in the mean nitrogen and phosphate concentrations between MMW and MAW, although the silica values were significantly higher in MAW. The Integrated chlorophyll a mean value was about 4 mg m−2, with a maximum of 13 mg m−2 at MAW stations. Higher Chlorophyll a records in typical MAW stations were mainly due to chlorophytes, which contributed up to 58% of the pigments concentrations in the MAWand about 46% in theMMW. The contribution of chlorophytes to total Chlorophyll a was found to be relatively stable throughout the water column. The contribution of diatoms, which were twofold higher in the MMW than in the MAW, did not exceed 17% of chlorophyll a and was mainly due to subsurface maxima. The chlorophytes, pelagophytes, prymnesiophytes and cryptophytes all together accounted for more than 77% of total chlorophyll a in the MAWand about 67% in the MMW. There were statistically significant differences between MMW and MAW in the pigment contribution of cyanobacteria and pelagophytes. These two taxa accounted for 13% and 24% of chlorophyll a respectively in the MAWand MMW indicating that these differences concerned phytoplankton classes at relatively low contributions to total chlorophyll a.
Phytoplankton dynamics related to water mass properties in the Gulf of Gabes: Ecological implications
22 mai 2010
The spatial distribution of chlorophylls and carotenoids was recorded throughout the Gulf of Gabes (South Ionian Sea) in March 2007, and was related to patterns of the physical structure and the nutrient concentrations. Two distinctwater masseswere identified based on the temperature and salinity (T–S) analysis: a cool and less salty Modified Atlantic Water (MAW) and a saltier Mediterranean Mixed Water (MMW). There was no significant difference in the mean nitrogen and phosphate concentrations between MMW and MAW, although the silica values were significantly higher in MAW. The Integrated chlorophyll a mean value was about 4 mg m−2, with a maximum of 13 mg m−2 at MAW stations. Higher Chlorophyll a records in typical MAW stations were mainly due to chlorophytes, which contributed up to 58% of the pigments concentrations in the MAWand about 46% in theMMW. The contribution of chlorophytes to total Chlorophyll a was found to be relatively stable throughout the water column. The contribution of diatoms, which were twofold higher in the MMW than in the MAW, did not exceed 17% of chlorophyll a and was mainly due to subsurface maxima. The chlorophytes, pelagophytes, prymnesiophytes and cryptophytes all together accounted for more than 77% of total chlorophyll a in the MAWand about 67% in the MMW. There were statistically significant differences between MMW and MAW in the pigment contribution of cyanobacteria and pelagophytes. These two taxa accounted for 13% and 24% of chlorophyll a respectively in the MAWand MMW indicating that these differences concerned phytoplankton classes at relatively low contributions to total chlorophyll a.
Spatial and temporal variations of microphytoplankton composition related to hydrographic conditions in the Gulf of Gabès
21 mai 2010
The spatial and temporal variations of the microphytoplankton communities were examined during four oceanographic cruises conducted between July 2005 and March 2007 aboard the RV ‘Hannibal'. Water thermal stratification started in May–June, and a thermocline established at 20 m depth, but ranged between 25 m during July and more than 30 m during September. The high concentrations of chlorophyll a were observed during the May–June semi-mixed conditions and were mainly correlated with the concentrations of phosphate, suggesting a potential limitation by this nutrient. The Bacillariophyceae were dominant in the coastal samples, whereas they declined in the offshore area, most likely due to silicate shortage. Cyanobacteriae developed over semi-mixed conditions and at the thermocline depth. Relatively constant abundance of dinoflagellates was observed during the sampling periods from the coast to the offshore area, mainly explained by the high diversity species of this group. The results suggest that some phytoplankton taxa are generally adapted to specific hydrological conditions, whereas the dinoflagellates did not seem to follow this trend. Our findings have important biogeochemical implications in relationship with the export fluxes of the particulate matter throughout the water column.
Spatial and temporal variations of microphytoplankton composition related to hydrographic conditions in the Gulf of Gabès
21 mai 2010
The spatial and temporal variations of the microphytoplankton communities were examined during four oceanographic cruises conducted between July 2005 and March 2007 aboard the RV ‘Hannibal'. Water thermal stratification started in May–June, and a thermocline established at 20 m depth, but ranged between 25 m during July and more than 30 m during September. The high concentrations of chlorophyll a were observed during the May–June semi-mixed conditions and were mainly correlated with the concentrations of phosphate, suggesting a potential limitation by this nutrient. The Bacillariophyceae were dominant in the coastal samples, whereas they declined in the offshore area, most likely due to silicate shortage. Cyanobacteriae developed over semi-mixed conditions and at the thermocline depth. Relatively constant abundance of dinoflagellates was observed during the sampling periods from the coast to the offshore area, mainly explained by the high diversity species of this group. The results suggest that some phytoplankton taxa are generally adapted to specific hydrological conditions, whereas the dinoflagellates did not seem to follow this trend. Our findings have important biogeochemical implications in relationship with the export fluxes of the particulate matter throughout the water column.
Distribution of zooplankton related to environmental factors in three interconnected reservoirs: Kasseb, Mornaguia and Ghdir El Goulla (North of Tunisia)
21 mai 2010
The spatial and temporal distribution of zooplankton and environmental parameters in Kasseb, Mornaguia and Ghdir El Goulla reservoirs (North of Tunisia) were studied monthly from July to December 2002 in order to establish seasonal patterns, biotic and abiotic relationships for these reservoirs. In Kasseb reservoir, the zooplankton community was dominated by Acanthocyclops sp. (37.3% of total zooplankton density) and Bosmina longirostris (32.6% of total zooplankton density). In Mornaguia and Ghdir El Goulla, Copidodiaptomus numidicus was the most abundant species with 62.1% and 97.5% of total zooplankton density respectively. Our study indicated that the zooplankton community of Ghdir El Goulla reservoir was influenced by the impact of internal environmental factors and artificially introduced water from the two Kasseb and Mornaguia reservoirs. Highest density of zooplankton species was recorded in Kasseb reservoir, which indicated an increased tendency for eutrophication. Mornaguia and Ghdir El Goulla are oligo-mesotrophic reservoirs. Understanding the relationship between the zooplankton community and temporal distribution is important for the understanding of trophic interactions within these reservoirs.
Distribution of zooplankton related to environmental factors in three interconnected reservoirs: Kasseb, Mornaguia and Ghdir El Goulla (North of Tunisia)
21 mai 2010
The spatial and temporal distribution of zooplankton and environmental parameters in Kasseb, Mornaguia and Ghdir El Goulla reservoirs (North of Tunisia) were studied monthly from July to December 2002 in order to establish seasonal patterns, biotic and abiotic relationships for these reservoirs. In Kasseb reservoir, the zooplankton community was dominated by Acanthocyclops sp. (37.3% of total zooplankton density) and Bosmina longirostris (32.6% of total zooplankton density). In Mornaguia and Ghdir El Goulla, Copidodiaptomus numidicus was the most abundant species with 62.1% and 97.5% of total zooplankton density respectively. Our study indicated that the zooplankton community of Ghdir El Goulla reservoir was influenced by the impact of internal environmental factors and artificially introduced water from the two Kasseb and Mornaguia reservoirs. Highest density of zooplankton species was recorded in Kasseb reservoir, which indicated an increased tendency for eutrophication. Mornaguia and Ghdir El Goulla are oligo-mesotrophic reservoirs. Understanding the relationship between the zooplankton community and temporal distribution is important for the understanding of trophic interactions within these reservoirs.
Abundance and biomass of rotifers in relation to the environmental factors in geothermal waters in Southern Tunisia
21 mai 2010
The spatial and temporal dynamics of rotifers in relation to the physico-chemical parameters in Fish- Culture Research Station (Southern Tunisia) were studied monthly from February 2005 to January 2006. Thirteen rotifer species were found: Brachionus urceolaris, Brachionus calyciflorus, Brachionus sp., Lecane stichaea, Lecane rhytida, Lecane sp., Hexarthra mira, Rotaria tardigrada, Conochiloides natans, Trichocerca marina, Keratella quadrata, Keratella cochlearis and Notommata codonella. The most dominant rotifer was B. urceolaris (76% of total abundance). Rotifer density and water temperature were negatively correlated (r ¼ 0.94, n ¼ 12, p ¼ 0.001). The highest abundance of rotifers was found in basin 4 (1.5105 indm3, in June 2005)
Abundance and biomass of rotifers in relation to the environmental factors in geothermal waters in Southern Tunisia
21 mai 2010
The spatial and temporal dynamics of rotifers in relation to the physico-chemical parameters in Fish- Culture Research Station (Southern Tunisia) were studied monthly from February 2005 to January 2006. Thirteen rotifer species were found: Brachionus urceolaris, Brachionus calyciflorus, Brachionus sp., Lecane stichaea, Lecane rhytida, Lecane sp., Hexarthra mira, Rotaria tardigrada, Conochiloides natans, Trichocerca marina, Keratella quadrata, Keratella cochlearis and Notommata codonella. The most dominant rotifer was B. urceolaris (76% of total abundance). Rotifer density and water temperature were negatively correlated (r ¼ 0.94, n ¼ 12, p ¼ 0.001). The highest abundance of rotifers was found in basin 4 (1.5105 indm3, in June 2005)
Microalgal cryo preservation using dimethyl sulfoxide(Me2SO) coupled with two freezing protocols: Influence on the fatty acid profile
20 mai 2010
Procedures for determining the optimal pre-freezing protocol for cryo-preservation of microalgae are discussed.Threealgalspecieswereused(Chlorellavulgaris, Isochrysis galbana and Dunaliella salina) and cryo-storedusingtwodifferentmethods:theslowcoolingandthefastfreezing.Intheslowcooling, each algaebatchwastreatedwithorwithoutcryo-protectant(dimethylsulfoxide:Me2SO 5%v/v).After 20 minat4 1C, themidi-straws were filled and cooled slowly (1.5 1C min1) to 140 1C, bya programmable freezer (Digitcool—IMV), before putting them directly into liquid nitrogen. Fast freezing was performedwith10%or15%Me2SO priortoplungingintoliquidnitrogen.Thethreealgalspecies followedthesamere-growthpatternasthatofthecontrols.Thepost-thawedviabilitywithMe2SO was good foralltheselectedalgae(C. vulgaris 495%, I. galbana and D. salina 470% ofthecontrol),applying the slowcooling.Thepost-thawedviabilitywithoutMe2SO was60%for I. galbana, 52%for D.salina and 33% for C. vulgaris. Fastfreezingwasnotsuitableforcryo-storageof I. galbana but gavegoodpost- thawingviabilityfor D. salina (70%).Thedecreaseinfattyacidcontentofthecryo-storedalgaewas influencedbythetemperature.Therapiddecreaseintemperatureinducedbyfastfreezingcanexplain the lowleveloffattyacidcontentofthethreecryo-storedalgae.Fattyacidprofilesshowthatthe nutritionalvaluesofthethreecryo-storedmicro-algaewerenotsignificantlyaffectedespeciallywhen treatedwithslowcoolingprotocols.
Microalgal cryo preservation using dimethyl sulfoxide(Me2SO) coupled with two freezing protocols: Influence on the fatty acid profile
20 mai 2010
Procedures for determining the optimal pre-freezing protocol for cryo-preservation of microalgae are discussed.Threealgalspecieswereused(Chlorellavulgaris, Isochrysis galbana and Dunaliella salina) and cryo-storedusingtwodifferentmethods:theslowcoolingandthefastfreezing.Intheslowcooling, each algaebatchwastreatedwithorwithoutcryo-protectant(dimethylsulfoxide:Me2SO 5%v/v).After 20 minat4 1C, themidi-straws were filled and cooled slowly (1.5 1C min1) to 140 1C, bya programmable freezer (Digitcool—IMV), before putting them directly into liquid nitrogen. Fast freezing was performedwith10%or15%Me2SO priortoplungingintoliquidnitrogen.Thethreealgalspecies followedthesamere-growthpatternasthatofthecontrols.Thepost-thawedviabilitywithMe2SO was good foralltheselectedalgae(C. vulgaris 495%, I. galbana and D. salina 470% ofthecontrol),applying the slowcooling.Thepost-thawedviabilitywithoutMe2SO was60%for I. galbana, 52%for D.salina and 33% for C. vulgaris. Fastfreezingwasnotsuitableforcryo-storageof I. galbana but gavegoodpost- thawingviabilityfor D. salina (70%).Thedecreaseinfattyacidcontentofthecryo-storedalgaewas influencedbythetemperature.Therapiddecreaseintemperatureinducedbyfastfreezingcanexplain the lowleveloffattyacidcontentofthethreecryo-storedalgae.Fattyacidprofilesshowthatthe nutritionalvaluesofthethreecryo-storedmicro-algaewerenotsignificantlyaffectedespeciallywhen treatedwithslowcoolingprotocols.
CORRESPONDENCE OF THE SEASONAL PATTERNS OF THE BRINE SHRIMP, ARTEMIA SALINA (LEACH, 1819) (ANOSTRACA) WITH SEVERAL ENVIRONMENTAL FACTORS IN AN ARID SOLAR SALTERN (SFAX, SOUTHERN TUNISIA)
20 mai 2010
We investigated the correspondence of the seasonal patterns of Artemia salina with several environmental factors along a natural salinity gradient in four ponds (M1, M2, M3, and B1) located in the arid solar saltern of Sfax (southern Tunisia). The shape of the frontal knobs of males showed the dominance of the autochthonous species, A. salina. Artemia abundance and fecundity were assessed. Biometrics of A. salina stages were studied by comparing cyst size and body length. A. salina abundance displayed a clear seasonal and spatial variation. Abundance of live Artemia ranged between 0.25 × 103 and 1414 × 103 ind m−3. The highest numbers were recorded in pond M3, as nauplii (771.8×103 ind m−3 corresponding to 31.8 g m−3). This resulted from low male and female numbers (34 and 17×103 ind m−3, respectively). Artemia cysts were predominant (92.96% of total Artemia), and grouped in small (216 μm) and large (243 μm) sized cysts, which correlated negatively with temperature (r = −0.4, N = 294, p < 0.01) and salinity (r = −0.39, N = 294, p < 0.01), and positively with female fecundity (r = 0.6, p < 0.05). The large (270 μm) and small (216 μm) cysts suggested the presence of also the species A. parthenogenetica and A. franciscana in the saltern, respectively. Fecundity showed a summer-autumn distribution that correlated significantly (−0.6 and −0.9, N = 35, p < 0.01) with both temperature and salinity. A. salina performed best in M2 (more than 80 cysts per brood), at about 200 g l−1 and 26.8◦C, with gravid females representing 20%. A. salina from the Sfax solar saltern was unable to withstand extreme temperatures (35◦C), but tolerated extreme salinity (330 g l−1). Abundance, biometrics, and reproductive descriptors of A. salina appeared to be governed chiefly by temperature and salinity, the physical structure of the saltern, and food availability, such as the unicellular green alga, Dunaliella salina. Nauplii (mean length: 401 μm) from small-sized cysts encountered in the saltern might be a valuable food source for hatcheries of some small-mouthed marine fish.
CORRESPONDENCE OF THE SEASONAL PATTERNS OF THE BRINE SHRIMP, ARTEMIA SALINA (LEACH, 1819) (ANOSTRACA) WITH SEVERAL ENVIRONMENTAL FACTORS IN AN ARID SOLAR SALTERN (SFAX, SOUTHERN TUNISIA)
20 mai 2010
We investigated the correspondence of the seasonal patterns of Artemia salina with several environmental factors along a natural salinity gradient in four ponds (M1, M2, M3, and B1) located in the arid solar saltern of Sfax (southern Tunisia). The shape of the frontal knobs of males showed the dominance of the autochthonous species, A. salina. Artemia abundance and fecundity were assessed. Biometrics of A. salina stages were studied by comparing cyst size and body length. A. salina abundance displayed a clear seasonal and spatial variation. Abundance of live Artemia ranged between 0.25 × 103 and 1414 × 103 ind m−3. The highest numbers were recorded in pond M3, as nauplii (771.8×103 ind m−3 corresponding to 31.8 g m−3). This resulted from low male and female numbers (34 and 17×103 ind m−3, respectively). Artemia cysts were predominant (92.96% of total Artemia), and grouped in small (216 μm) and large (243 μm) sized cysts, which correlated negatively with temperature (r = −0.4, N = 294, p < 0.01) and salinity (r = −0.39, N = 294, p < 0.01), and positively with female fecundity (r = 0.6, p < 0.05). The large (270 μm) and small (216 μm) cysts suggested the presence of also the species A. parthenogenetica and A. franciscana in the saltern, respectively. Fecundity showed a summer-autumn distribution that correlated significantly (−0.6 and −0.9, N = 35, p < 0.01) with both temperature and salinity. A. salina performed best in M2 (more than 80 cysts per brood), at about 200 g l−1 and 26.8◦C, with gravid females representing 20%. A. salina from the Sfax solar saltern was unable to withstand extreme temperatures (35◦C), but tolerated extreme salinity (330 g l−1). Abundance, biometrics, and reproductive descriptors of A. salina appeared to be governed chiefly by temperature and salinity, the physical structure of the saltern, and food availability, such as the unicellular green alga, Dunaliella salina. Nauplii (mean length: 401 μm) from small-sized cysts encountered in the saltern might be a valuable food source for hatcheries of some small-mouthed marine fish.
Abundance and Biomass of the Ciliate Community during a Spring Cruise in the Gulf of Gabes (Eastern Mediterranean Sea, Tunisia)
19 mai 2010
We studied the spring spatial distribution of the ciliate community coupled with environmental factors along the coast and in the open sea at 30 stations sampled (between 27 May and 9 June 2006) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 61 taxa belonging to 36 genera and 5 taxonomic classes were identified. The ciliate assemblage was numerically dominated by spirotrichs (86% of total ciliates). This group is largely dominated by the choreotrichs (92%) among which tintinnids represented 99%. The total ciliates abundance showed a gradual decrease from the coastal area to the open sea and an increase from the surface to the bottom. The maximum abundance (400 cells l-1) and biomass (6.29 μgC l-1) were found in station 27, close to Djerba Island. The tinitinnid Rhabdonella spiralis was cosmopolitan, being found almost at every station and at each depth, while other taxa may be exclusive to the neritic area, others to the open sea area. The distribution of species in the Gulf of Gabes seemed most likely influenced by the combined effects of hydrographic conditions, zooplankton predation and urban interferences.
Abundance and Biomass of the Ciliate Community during a Spring Cruise in the Gulf of Gabes (Eastern Mediterranean Sea, Tunisia)
19 mai 2010
We studied the spring spatial distribution of the ciliate community coupled with environmental factors along the coast and in the open sea at 30 stations sampled (between 27 May and 9 June 2006) in the Gulf of Gabes (Tunisia, Eastern Mediterranean Sea). A total of 61 taxa belonging to 36 genera and 5 taxonomic classes were identified. The ciliate assemblage was numerically dominated by spirotrichs (86% of total ciliates). This group is largely dominated by the choreotrichs (92%) among which tintinnids represented 99%. The total ciliates abundance showed a gradual decrease from the coastal area to the open sea and an increase from the surface to the bottom. The maximum abundance (400 cells l-1) and biomass (6.29 μgC l-1) were found in station 27, close to Djerba Island. The tinitinnid Rhabdonella spiralis was cosmopolitan, being found almost at every station and at each depth, while other taxa may be exclusive to the neritic area, others to the open sea area. The distribution of species in the Gulf of Gabes seemed most likely influenced by the combined effects of hydrographic conditions, zooplankton predation and urban interferences.
Sur la route des Flandres. Les liens entre les Pays-Bas méridionaux et le comté de Bourgogne.
17 mai 2010
Sur la route des Flandres. Les liens entre les Pays-Bas méridionaux et le comté de Bourgogne.
17 mai 2010
Éléments d'écologie de la transmission d'Echinococcus multilocularis en Chine (Sichuan) Modélisation des distributions spatiales des communautés et populations des hôtes : des données de terrain aux prédictions
17 mai 2010
La transmission du parasite Echinococcus multilocularis à l'origine d'une zoonose fatale chez l'homme, l'échinococcose alvéolaire, peut être modulée par des perturbations anthropiques de l'écologie des populations de ses hôtes intermédiaires (micro-mammifères) et définitifs (canidés). Nous avons étudié des paramètres écologiques des populations de ces hôtes dans la province du Sichuan, en Chine, où sont observées de fortes prévalences humaines. Sur la base de données de piégeage, la définition d'assemblages d'espèces de micro-mammifères a permis de résumer la grande diversité des habitats échantillonnés et des espèces piégées. Nous avons trouvé que les régressions multiples non-linéaires étaient la méthode la plus performante pour modéliser les distributions des assemblages le long de gradients environnementaux extraits d'images satellites telles que l'altitude, la pente et des indices de végétation. Alors que les modèles locaux n'étaient pas transférables sur des sites distants d'une centaine de km, une classification régionale des groupes de transmission a pu être établie. D'autre part, les analyses des distributions spatiales des fèces de canidés, de leurs contaminations et des trajectoires nocturnes de chiens équipés de colliers GPS ont permis de confirmer et de quantifier le rôle prédominant du chien sur le renard dans la contamination environnementale et de localiser des zones à haut risque de transmission près des habitations. Enfin, des interactions spatiales entre les chiens et les micro-mammifères ont été mises en évidence dans les villages et constituent une estimation préliminaire du taux de contact entre les hôtes requis pour modéliser la transmission.
Éléments d'écologie de la transmission d'Echinococcus multilocularis en Chine (Sichuan) Modélisation des distributions spatiales des communautés et populations des hôtes : des données de terrain aux prédictions
17 mai 2010
La transmission du parasite Echinococcus multilocularis à l'origine d'une zoonose fatale chez l'homme, l'échinococcose alvéolaire, peut être modulée par des perturbations anthropiques de l'écologie des populations de ses hôtes intermédiaires (micro-mammifères) et définitifs (canidés). Nous avons étudié des paramètres écologiques des populations de ces hôtes dans la province du Sichuan, en Chine, où sont observées de fortes prévalences humaines. Sur la base de données de piégeage, la définition d'assemblages d'espèces de micro-mammifères a permis de résumer la grande diversité des habitats échantillonnés et des espèces piégées. Nous avons trouvé que les régressions multiples non-linéaires étaient la méthode la plus performante pour modéliser les distributions des assemblages le long de gradients environnementaux extraits d'images satellites telles que l'altitude, la pente et des indices de végétation. Alors que les modèles locaux n'étaient pas transférables sur des sites distants d'une centaine de km, une classification régionale des groupes de transmission a pu être établie. D'autre part, les analyses des distributions spatiales des fèces de canidés, de leurs contaminations et des trajectoires nocturnes de chiens équipés de colliers GPS ont permis de confirmer et de quantifier le rôle prédominant du chien sur le renard dans la contamination environnementale et de localiser des zones à haut risque de transmission près des habitations. Enfin, des interactions spatiales entre les chiens et les micro-mammifères ont été mises en évidence dans les villages et constituent une estimation préliminaire du taux de contact entre les hôtes requis pour modéliser la transmission.
Risk of complications after abdominal paracentesis in cirrhotic patients: a prospective study.
17 mai 2010
BACKGROUND & AIMS: Complications and technical problems of paracentesis in cirrhotic patients are infrequent. However, the severity and the incidence of these events and their risk factors have not been assessed prospectively. METHODS: Cirrhotic patients (n = 171) undergoing paracentesis were included. Of the 515 paracenteses, 8.8% were diagnostic, and 91.2% were therapeutic. Technical features, demographic data, and adverse events during a period of 72 hours after the procedure were examined. RESULTS: Major complications occurred in 1.6% of procedures and included 5 bleedings and 3 infections, resulting in death in 2 cases. Major complications were associated with therapeutic but not diagnostic procedures and tended to be more prevalent in patients with low platelet count (<50 10(9)/L), Child-Pugh stage C, and in alcoholic cirrhosis patients. Technical problems occurred in 5.6%. The most frequent complication was a leak of ascites at the puncture site (5.0%), and in 89.5% there were no complications. CONCLUSIONS: The safety of paracentesis in cirrhotic patients might be decreased if risk factors, which depend on the characteristics of the patient and of the procedure itself, are present.
Risk of complications after abdominal paracentesis in cirrhotic patients: a prospective study.
17 mai 2010
BACKGROUND & AIMS: Complications and technical problems of paracentesis in cirrhotic patients are infrequent. However, the severity and the incidence of these events and their risk factors have not been assessed prospectively. METHODS: Cirrhotic patients (n = 171) undergoing paracentesis were included. Of the 515 paracenteses, 8.8% were diagnostic, and 91.2% were therapeutic. Technical features, demographic data, and adverse events during a period of 72 hours after the procedure were examined. RESULTS: Major complications occurred in 1.6% of procedures and included 5 bleedings and 3 infections, resulting in death in 2 cases. Major complications were associated with therapeutic but not diagnostic procedures and tended to be more prevalent in patients with low platelet count (<50 10(9)/L), Child-Pugh stage C, and in alcoholic cirrhosis patients. Technical problems occurred in 5.6%. The most frequent complication was a leak of ascites at the puncture site (5.0%), and in 89.5% there were no complications. CONCLUSIONS: The safety of paracentesis in cirrhotic patients might be decreased if risk factors, which depend on the characteristics of the patient and of the procedure itself, are present.
Les stèles funéraires de la nécropole de Pont-l'Évêque : Contextes de découverte et étude du corpus.
14 mai 2010
Les stèles funéraires de la nécropole de Pont-l'Évêque : Contextes de découverte et étude du corpus.
14 mai 2010
Assessment of dust sampling methods for the study of cultivable-microorganism exposure in stables.
14 mai 2010
Studies have shown a link between living on a farm, exposure to microbial components (e.g., endotoxins or beta-d-glucans), and a lower risk for allergic diseases and asthma. Due to the lack of validated sampling methods, studies of asthma and atopy have not relied on exposure assessment based on culture techniques. Our objective was therefore to compare several dust sampling methods for the detection of cultivable-microorganism exposure in stables. Sixteen French farms were sampled using four different methods: (i) active air sampling using a pump, (ii) passive dust sampling with a plastic box, (iii) dust sampling with an electrostatic dust fall collector (wipe), and (iv) dust sampling using a spatula to collect dust already settled on a windowsill. The results showed that collection of settled dust samples with either plastic boxes or wipes was reproducible (pairwise correlations, 0.72 and 0.73, respectively) and resulted in highly correlated results (pairwise correlation between the two methods, 0.82). We also found that settled dust samples collected with a plastic box correctly reflected the composition of the samples collected in the air of the stable when there was no farmer activity. A loss of microbial diversity was observed when dust was kept for 3 months at room temperature. We therefore conclude that measurement of viable microorganisms within a reasonable time frame gives an accurate representation of the microbial composition of stable air.
Assessment of dust sampling methods for the study of cultivable-microorganism exposure in stables.
14 mai 2010
Studies have shown a link between living on a farm, exposure to microbial components (e.g., endotoxins or beta-d-glucans), and a lower risk for allergic diseases and asthma. Due to the lack of validated sampling methods, studies of asthma and atopy have not relied on exposure assessment based on culture techniques. Our objective was therefore to compare several dust sampling methods for the detection of cultivable-microorganism exposure in stables. Sixteen French farms were sampled using four different methods: (i) active air sampling using a pump, (ii) passive dust sampling with a plastic box, (iii) dust sampling with an electrostatic dust fall collector (wipe), and (iv) dust sampling using a spatula to collect dust already settled on a windowsill. The results showed that collection of settled dust samples with either plastic boxes or wipes was reproducible (pairwise correlations, 0.72 and 0.73, respectively) and resulted in highly correlated results (pairwise correlation between the two methods, 0.82). We also found that settled dust samples collected with a plastic box correctly reflected the composition of the samples collected in the air of the stable when there was no farmer activity. A loss of microbial diversity was observed when dust was kept for 3 months at room temperature. We therefore conclude that measurement of viable microorganisms within a reasonable time frame gives an accurate representation of the microbial composition of stable air.
The hydrothermal carbonated complexes in the Acambaro Valley: precolumbian and modern human impacts
13 mai 2010
The hydrothermal carbonated complexes in the Acambaro Valley: precolumbian and modern human impacts
13 mai 2010
Evidence for active folding along the northwestern end of the Jura belt, northern alpine domain
13 mai 2010
Evidence for active folding along the northwestern end of the Jura belt, northern alpine domain
13 mai 2010
[hal-00464330] La poterie Hoguette de Choisey (Jura), les Champins. Observations techniques et insertion régionale
12 mai 2010
The detailed technical analysis of a remarkable Hoguette type pot, attributed to the 54th-53rd centuries B.C., demonstrates that the diffusion of a new technique, that of pottery, is tied to specific types of know-how. The production of such pots, whose use for ostentatious display has been demonstrated, was probably in the hands of skilled potters. Later, towards 5000-4900 B.C., we witness a simplification in the technique of Hoguette pottery production, which precedes the end of La Hoguette pottery. The authors propose a scenario concerning the conditions for the introduction and development of this "First Neolithic" of Mediterranean origin as far as the valleys of the Neckar and the Rhine, whilst the cultivation of cereals, flax and poppies is associated with substantial forest clearance in the French Jura just after the middle of the 6th millennium.
Settlement patterns and territories over the long term from Prehistory to the Middle Ages
11 mai 2010
Several projects, developed since the 1990s, provide the background for the ideas and questions on which this paper will focus. From the European programs 'Archaeomedes' I (1992-1994) and II (1996-1999) to the Archaedyn I project (2005-2007, ACI 'Spaces and Territories') and II (2009-2010), the object was to analyze the evolution of settlement patterns over a long period, from the Iron Age to the Middle Ages. These successive programs provided a common protocol for comparing several areas located in the Rhône valley (Archaeomedes ) and, later on, in different parts of France: Center, North-East and South-East, as well as in Slovenia (Archaedyn ).
Les changements dans la végétation à l'Holocène au Lac du Ledro (Trentino, Italy).
7 mai 2010
Dans le cadre du projet ANR LAMA coordonné par M. Magny et N. Combourieu-Nebout, nous présentons de nouvelles analyses palynologiques de 3 carottes prélevées au Lac du Ledro (Trentino, Italie). Ce lac, avec un bassin versant de 48 km2, se trouve au sud des Alpes à 650 m d'altitude. Les carottes (...)
Déclin de la fonction respiratoire chez les producteurs laitiers : influence des poussières organiques
1er mai 2010
Bronze Age at Lake Bourget (NW Alps, France): Vegetation, human impact and climatic change.
30 avril 2010
Pollen analyses of three sediment cores performed on the archaeological lake dwellings of Chindrieux and Tresserve (Savoie, France), on the eastern shore of Lake Bourget, enable the reconstruction of vegetation history and human impact during the Bronze Age. Results show a good correlation between lake-level fluctuations and the evolution of anthropogenic indicators. The end of the Neolithic period and the early Bronze Age are characterised by a discreet occupation of the Lake Bourget surroundings, in spite of a warmer climatic condition. The middle Bronze Age, contemporaneous with wetter and cooler conditions, is related to a decrease in pollen of cultivated plants and weed. Farming activities reappear in the late Bronze Age and human impact increases suddenly at the very end of the late Bronze Age. Three anthropogenic phases are clearly visible: a short decrease in anthropogenic indicators and a high lake-level phase occur in the middle of this period of intense farming development. A new decrease in human impact appears at the beginning of the Iron Age.
Les recherches de Julien Feuvrier (1851-1936), historien, archéologue, archiviste et conservateur du musée
29 avril 2010
Une hache à fonction rituelle ? La hache en jadéitite alpine d'Ostheim (Haut-Rhin)
23 avril 2010
hache en jade plantée verticalement dans le sol
Le Néolithique du Jura : de la première poterie aux villages fortifiés
23 avril 2010
Evolution culturelle du Néolithique dans le nord du Jura
Une production du Mont Viso en Italie : l'ébauche de haches de Lugrin (Haute-Savoie, France)
23 avril 2010
Production de haches néolithiques par sciage
L'Unique, la Paire, les Multiples. A propos des dépôts de haches polies en roches alpines en Europe occidentale pendant les Ve et IVe millénaires
23 avril 2010
Signification sociale des grandes haches néolithiques en jades alpins
Grabanlagen des frühen Endneolithikums und der späten Hallstattzeit in Jettingen-Unterjettingen, Hau, Lkr. Böblingen - ein Beitrag zur Megalithik im Flussgebiet des Neckars
23 avril 2010
hache en jadéitite dans une sépulture collective
L'habitat rural en Alsace au premier Moyen Âge : une diversité de plans et d'évolutions encore peu explicitée.
11 avril 2010
[Bronchial involvement in hypersensitivity pneumonitis]
10 avril 2010
Hypersensitivity pneumonitis is a respiratory disease resulting from the inhalation of antigens to which the exposed subject has been previously sensitized. Hypersensitivity pneumonitis is characterized by a diffuse and predominantly mononuclear cell inflammation of the alveolar regions that involves the small airways in most cases. It explains the presence of mosaic attenuation and expiratory air trapping at HRCT Scan. Chronic bronchitis, an obstructive defect at lung function tests and emphysema as long-term outcome are frequent consequences of this bronchial involvement.
Maxillary sinus fungus ball due to Rhizomucor pusillus : an uncommun clinical presentation of mucormycosis
23 mars 2010
Misidentification of the emerging pathogenic yeasts Candida nivariensis as Zygosaccharamyces sp.
22 mars 2010
Scedosporium prolificans: an emerging pathogen in France?
22 mars 2010
For the last ten years, non-Aspergillus mold species have been increasingly involved in human invasive infections, probably as a consequence of more intense immunosuppression and prolonged patient survival, and of selective pressure since antifungal agents are currently used for prophylaxis or therapy. Scedosporium prolificans, one of these emerging fungi, has been isolated in a broad spectrum of clinical presentations in humans, including respiratory-tract colonization, superficial or locally invasive infections, and disseminated infections in immunocompromised patients. Here, we report the recent emergence of invasive infections due to S. prolificans in France, and describe four new cases diagnosed during the last six years. Only one disseminated scedosporiosis has been reported before this in France, in 1994. Three out of our four cases were breakthrough infections in immunocompromised patients receiving posaconazole or voriconazole therapy. The aims of the present review were thus to gain a better understanding of scedosporiosis epidemiology and clinical features, and to review recent advances in multimodal management of these infections, including surgery, recovery and/or enhancement of immunity, and antifungal combinations, especially voriconazole plus terbinafine.
Molecular and phenotypic evaluation of Lichtheimia corymbifera (formerly Absidia corymbifera) complex isolates associated with human mucormycosis: rehabilitation of L. ramosa.
22 mars 2010
Thirty-eight isolates (including 28 isolates from patients) morphologically identified as Lichtheimia corymbifera (formerly Absidia corymbifera) were studied by sequence analysis (analysis of the internal transcribed spacer [ITS] region of the ribosomal DNA, the D1-D2 region of 28S, and a portion of the elongation factor 1alpha [EF-1alpha] gene). Phenotypic characteristics, including morphology, antifungal susceptibility, and carbohydrate assimilation, were also determined. Analysis of the three loci uncovered two well-delimited clades. The maximum sequence similarity values between isolates from both clades were 66, 95, and 93% for the ITS, 28S, and EF-1alpha loci, respectively, with differences in the lengths of the ITS sequences being detected (763 to 770 bp for isolates of clade 1 versus 841 to 865 bp for isolates of clade 2). Morphologically, the shapes and the sizes of the sporangiospores were significantly different among the isolates from both clades. On the basis of the molecular and morphological data, we considered isolates of clade 2 to belong to a different species named Lichtheimia ramosa because reference strains CBS 269.65 and CBS 270.65 (which initially belonged to Absidia ramosa) clustered within this clade. As neotype A. corymbifera strain CBS 429.75 belongs to clade 1, the name L. corymbifera was conserved for clade 1 isolates. Of note, the amphotericin B MICs were significantly lower for L. ramosa than for L. corymbifera (P < 0.005) but were always
[Regional audit on fluoroquinolones usage in the hospital and the community: Are these antibiotics over-used?]
19 mars 2010
AIM OF THE STUDY: The ecological impact of an over-use or a mis-use of fluoroquinolones (FQs) appears of great importance according to published data. With the objective to set up a regional antibiotic stewardship program, we conducted a regional audit on FQs usage. MATERIAL ET METHODS: Ninety general practionners and 15 health care facilities participated to this prospective study. Overall, 511 prescriptions were evaluated (276 from hospital physicians and 235 [46%] from general practionners). The compliance of FQs prescription with national recommendations and with a regional referential was assessed. This regional referential was established in order to preserve FQs. RESULTS: Only 14,3% of the prescriptions complied with the regional referential, even if the choice of FQs were in accordance with national recommendations in 56,8% of the prescriptions. Urinary tract infections (mostly non-complicated) were the most common indication for FQs prescription. CONCLUSION: Analysis of FQs prescriptions shows that there is a significant potential for FQs preservation in Franche-Comté.
Aortic valve replacement for active infective endocarditis: 5-year survival comparison of bioprostheses, homografts and mechanical prostheses.
19 mars 2010
Objective: In the surgical treatment of acute aortic valve infective endocarditis (IE), the long-term outcome depending on the choice of valve replacement remains uncertain. We aimed to compare the impact on 5-year mortality of use of three types of implanted valves: bioprosthesis (heterograft), mechanical prosthesis and homograft. Methods: A total of 167 patients with a definite aortic valve IE who underwent aortic replacement were selected from a prospective observational population-based study. Association between the type of implanted valve and 5-year mortality was examined by the use of an adjusted Cox model. Results: Bioprostheses were implanted in 31 patients (18.6%), homograft in 27 (16.2%) and mechanical valves in 109 (65.2%). Patients with bioprothesis had a higher 5-year mortality risk than patients with mechanical prosthesis (adjusted hazard ratio (HR) 2.39, 95% confidence interval (95% CI), 1.09-5.21; p=0.029), particularly in patients 65 years old (adjusted HR: 1.45 (0.35-5.97), p=0.60). Five-year mortality risk did not differ between patients with homografts and those with mechanical prostheses (HR 0.46, 95% CI (0.15-1.42), p=0.18). Conclusions: A bioprosthetic valve used for aortic valve IE replacement may be associated with lower overall 5-year survival than the use of a mechanical valve in patients up to 65 years old. Further studies are needed to explain these results.
Clinical consensus conference: survey on Gram-positive bloodstream infections with a focus on Staphylococcus aureus.
19 mars 2010
The increased incidence over the past decade of bloodstream infections (BSIs) caused by gram-positive bacteria, particularly methicillin-resistant Staphylococcus aureus, highlights the critical need for a consistent approach to therapy. However, there is currently no international consensus on the diagnosis and management of gram-positive BSIs. The Clinical Consensus Conference on Gram-Positive Bloodstream Infections was convened as a session at the 9th International Symposium on Modern Concepts in Endocarditis and Cardiovascular Infections held in 2007. Participants discussed various aspects of the practical treatment of patients who present with gram-positive BSI, including therapeutic options for patients with BSIs of undefined origin, the selection of appropriate empirical therapy, and treatment of complicated and uncomplicated BSIs. The opinions of participants about these key issues are reflected in this article.
[Differentiating bacterial from viral meningitis: contribution of nonmicrobiological laboratory tests]
19 mars 2010
In most cases, differentiating viral from bacterial meningitis is relatively easy, based on clinical examination, CSF appearance and results of CSF examination (cytology, biochemistry and Gram stain). However, in about 20% of cases, this diagnosis may be difficult. For such cases, additional non-microbiological tests may be helpful. CSF lactate level is a good predictor of bacterial meningitis for values greater than 3.5 mmol/l. Serum procalcitonin is effective to discriminate between bacterial and viral meningitis, using a threshold between 1 and 2 ng/ml, although this parameter may fail in individual situations. Accurate diagnosis scores or models have been validated and may be used in routine clinical practice, especially in emergency rooms, both for adults and children to help identify patients with a very low probability of bacterial meningitis in whom antibiotic may thus be avoided.
Étude des transferts du tritium atmosphérique chez la laitue: étude cinétique, état d'équilibre et intégration du tritium sous forme organique lors d'une exposition atmosphérique continue
16 mars 2010
Ce travail de thèse a concerné l'étude des phénomènes d'absorption et d'incorporation sous forme organique du tritium dans un végétal de consommation courante, la laitue (Lactuca sativa L.), en réponse à une exposition atmosphérique. Il apparaît que la voie foliaire joue un rôle primordial dans (...)
[hal-00453638] Traitement des eaux par dur chitosane - Intérêts, méthodes et perspectives
5 février 2010
N/A
Nosocomial transmission of hepatitis B from an infected healthcare worker to a patient, France, 2005
2 février 2010
In 2005, following seroconversion by hepatitis B virus in a patient who underwent surgery, an investigation was carried out to identify the origin of the contamination. Evidence collected through this investigation strongly suggests a likely nosocomial transmission from a healthcare worker to a (...)
[hal-00451030] Applied geophysics in archaeological prospecting at sites of Authumes (Saône-et-Loire) and Mirebeau (Côte-d'Or) (Bourgogne, Eastern France)
28 janvier 2010
N/A
Variability of the groundwater sulfate concentration in fractured rock slopes: a tool to identify active unstable areas
22 décembre 2009
Water chemical analysis of 100 springs from the Orco and the Tinée valleys (Western Italy and Southern France) and a 7 year groundwater chemistry monitoring of the 5 main springs were performed. All these springs drain from crystalline rock slopes. Some of these drain from currently active (...)
Dynamique des épidémies de choléra dans la région des grands lacs africains: cas de la République Démocratique du Congo
16 décembre 2009
Le choléra est une maladie diarrhéique contagieuse strictement humaine, causée par Vibrio cholerae, un bacille gram négatif. La maladie se traduit par une diarrhée acqueuse profuse parfois accompagnée de vomissements survenant quelques heures à quelques jours après l'ingestion d'eau ou d'aliments (...)
Habitat, terroirs et territoire en Languedoc oriental durant l'Antiquité. Approche spatio-temporelle d'un système de peuplement.
4 novembre 2009
Cette étude porte sur une portion du territoire de la cité de Nîmes durant l'Antiquité. L'espace considéré, de Montpellier et Lattes à l'ouest, au Vidourle à l'est – en englobant les communes qui jouxtent la rive gauche du fleuve –, du littoral au sud à Combas et Montpezat, dans la « garrigue », au nord, (...)
Various Litter Species and High Water-Table Levels Hamper Type II Methanotrophs in a Bare Peatland Regeneration Experiment
1er octobre 2009
Significant areas of temperate bogs have been damaged by peat harvesting. After abandonment and spontaneous regeneration, these secondary mires can become important methane sources towards the atmosphere (Basiliko et al., 2007). Recent studies have shown the importance of methane oxidising (...)
Bronze Age at Lake Bourget (NW Alps, France): vegetation, human impact and climate change
26 juin 2009
Risk of cancer in the vicinity of municipal solid waste incinerators: importance of using a flexible modelling strategy.
24 juin 2009
ABSTRACT: BACKGROUND: We conducted an ecological study in four French administrative departments and highlighted an excess risk in cancer morbidity for residents around municipal solid waste incinerators. The aim of this paper is to show how important are advanced tools and statistical techniques to better assess weak associations between the risk of cancer and past environmental exposures. METHODS: The steps to evaluate the association between the risk of cancer and the exposure to incinerators, from the assessment of exposure to the definition of the confounding variables and the statistical analysis carried out are detailed and discussed. Dispersion modelling was used to assess exposure to sixteen incinerators. A geographical information system was developed to define an index of exposure at the IRIS level that is the geographical unit we considered. Population density, rural/urban status, socio-economic deprivation, exposure to air pollution from traffic and from other industries were considered as potential confounding factors and defined at the IRIS level. Generalized additive models and Bayesian hierarchical models were used to estimate the association between the risk of cancer and the index of exposure to incinerators accounting for the confounding factors. RESULTS: Modelling to assess the exposure to municipal solid waste incinerators allowed accounting for factors known to influence the exposure (meteorological data, point source characteristics, topography). The statistical models defined allowed modelling extra-Poisson variability and also non-linear relationships between the risk of cancer and the exposure to incinerators and the confounders. CONCLUSIONS: In most epidemiological studies distance is still used as a proxy for exposure leading to significant exposure missclassification. Additionally, in geographical correlation studies the non-linear relationships are usually not accounted for in the statistical analysis. In studies of weak associations it is important to use advanced methods to better assess dose-response relationships with disease risk.
Passive concentration of REE during skarn formation: example from the Querigut massif (Pyrénées, France)
23 juin 2009
Late Holocene summer temperature reconstruction from chironomid assemblages of Lake Anterne, northern French Alps
27 mai 2009
We present a chironomid-based reconstruction of late-Holocene temperature from Lake Anterne (2060 m a.s.l.) in the northern French Alps. Chironomid assemblages were studied in 49 samples along an 8 m long sediment core covering the last 1800 years. July air temperatures were inferred using an inference model based on the distribution of chironomid assemblages in 100 Swiss lakes. The transfer function has a leave-one-out cross-validated coefficient of determination (r2) of 0.88, a root mean square error of prediction (RMSEP) of 1.40°C. Despite possible biases induced by methodological aspects and the ecological complexity of the chironomid response to both climate and environmental changes, the concordance of the Lake Anterne temperature reconstruction with other Alpine records suggests that the transfer function has successfully reconstructed past summer temperature during the last two millennia. The twentieth century is the only section of the record which shows a poor agreement with other climate reconstructions and the distinct warming found in most instrumental records for this period is not apparent in the Lake Anterne record. Stocking of the lake with fish from the early twentieth century onwards was found to be a possible cause of changes in the chironomid fauna and subsequent distortion in the inferred climate signal. Evidence was found of a cold phase at Lake Anterne between AD 400 and 680, a warm episode between AD 680 and 1350, and another cold phase between AD 1350 and 1900. These events were possibly correlated to the so-called ‘Dark Age Cold Period' (DACP), the ‘Mediaeval Warm Period' (MWP) and the ‘Little Ice Age' (LIA). The chironomid-based inference model reconstructed a July air temperature decrease of c. 0.7°C for the DACP and 1.3°C for the LIA compared with the temperature prevailing during the MWP.
L'apport du laser scanneur aéroportéà l'étude des parcellaires gallo-romains du massif forestier de Haye (Meurthe-et-Moselle)
27 mai 2009
Les grandes forêts implantées sur le plateau calcaire des revers de la Côte de Moselle en Lorraine, recèlent de nombreux parcellaires fossiles d'époque gallo-romaine. Ces vestiges font l'objet de travaux depuis 1998 par une équipe pluridisciplinaire, composée d'archéologues du SRA de Lorraine et de l'INRAP, de chercheurs de l'INRA et d'agents de l'ONF. Un levé topographique par laser scanneur aéroporté ou LIDAR a été réalisé en mars 2007 dans le massif forestier de Haye, sur une surface de 113 km2. Il avait pour objectif de compléter et de préciser la localisation des vestiges de parcellaires antiques, mais aussi de recueillir des données sur les peuplements forestiers. Cette communication visait, après une présentation de cette nouvelle méthode, à montrer ses apports pour l'étude de ce type de vestiges archéologiques : analyse critique des résultats (types de vestiges détectés, taux de détection des vestiges selon les contextes, etc) et modalités d'utilisation des résultats dans un SIG.
Cholera Epidemics, War and Disasters around Goma and Lake Kivu: An Eight-Year Survey.
23 mai 2009
BACKGROUND: During the last eight years, North and South Kivu, located in a lake area in Eastern Democratic Republic of Congo, have been the site of a major volcano eruption and of numerous complex emergencies with population displacements. These conditions have been suspected to favour emergence and spread of cholera epidemics. METHODOLOGY/PRINCIPAL FINDINGS: In order to assess the influence of these conditions on outbreaks, reports of cholera cases were collected weekly from each health district of North Kivu (4,667,699 inhabitants) and South Kivu (4,670,121 inhabitants) from 2000 through 2007. A geographic information system was established, and in each health district, the relationships between environmental variables and the number of cholera cases were assessed using regression techniques and time series analysis. We further checked for a link between complex emergencies and cholera outbreaks. Finally, we analysed data collected during an epidemiological survey that was implemented in Goma after Nyiragongo eruption. A total of 73,605 cases and 1,612 deaths of cholera were reported. Time series decomposition showed a greater number of cases during the rainy season in South Kivu but not in North Kivu. Spatial distribution of cholera cases exhibited a higher number of cases in health districts bordering lakes (Odds Ratio 7.0, Confidence Interval range 3.8-12.9). Four epidemic reactivations were observed in the 12-week periods following war events, but simulations indicate that the number of reactivations was not larger than that expected during any random selection of period with no war. Nyiragongo volcanic eruption was followed by a marked decrease of cholera incidence. CONCLUSION/SIGNIFICANCE: Our study points out the crucial role of some towns located in lakeside areas in the persistence of cholera in Kivu. Even if complex emergencies were not systematically followed by cholera epidemics, some of them enabled cholera spreading.
Do parafluvial zones have an impact in regulating river pollution? Spatial and temporal dynamics of nutrients, carbon, and bacteria in a large gravel bar of the Doubs River (France)
8 mai 2009
The changes in both physical and chemical properties of interstitial water were investigated within a large gravel bar to determine if the parafluvial zone was a hotspot for nutrient transformations in a lowland eutrophic river, the Doubs (Eastern France). Interstitial water was sampled in 30 piezometers along five transects across the gravel bar, surface water was sampled in main and chute channels. Five campaigns of sampling were performed among summer and winter. In both interstitial and surface samples, water chemistry (electrical conductivity, pH, chloride, dissolved oxygen concentrations—DO) and nutrient concentrations (nitrate—NO3 −, ammonium—NH4 +, soluble reactive phosphorus—SRP, dissolved organic carbon—DOC) were measured. Moreover, temperature, water level, sediment grain size distribution and total bacterial abundance were assessed along a flowpath through a lateral gravel bar of the Doubs River. Measurements of water table elevation in the bar, main and chute channels indicated that the parafluvial flowpath was perpendicular to the main channel. Very low changes in chloride concentration and electrical conductivity showed minor groundwater input along the flowpath. The parafluvial zone was 0.9 m thick under the mean piezometric level, hydraulic gradients along the flowpath were 0.3%, and the discharge of interstitial water through the bar calculated at low flow was 40.6 m3 day−1. Most changes in interstitial nutrients occurred during the warm season, suggesting that biotic mechanisms occurred. Along the flowpath, DO, DOC, and bacterial abundance declined, while phosphate increased. Temporal trends of nitrate were less clear, exhibiting a slight increase during spring (organic matter biodegradation) and a decrease during summer (denitrification). Using the parafluvial discharge and nutrient concentrations of water infiltrating into and seeping from the gravel bar, the retention capacity of the bar was 171 gC day−1 for DOC and 48.3 gN day−1 for nitrate. Phosphate production ranged from 0.65 to 2.3 gP day−1. These values were low compared to the nutrient fluxes in the river Doubs, suggesting a minimal local impact of the parafluvial zone in regulating of river pollution.
Mechanical decoupling of high-pressure crustal units during continental subduction
6 mai 2009
The mechanics of the transition from continental subduction toward upper crustal nappe stacking is still poorly understood and is studied here through a 2D thermal and strength numerical modeling of a subducted passive margin. Geological observations in the core of most mountain belts show the piling up of several HPLT upper crustal units that are most likely related to the detachment of upper crustal units from the subducted continental margin and to the subsequent stacking of the detached units at depths. The Adula unit (Lepontine Dome, Central Alps, Switzerland) is a long and thin upper crustal unit and is used here as a natural case-study as it provides a well-documented example of these units. 2D thermal modeling shows that two steps, successive in time, characterized the burial history of the passive margin undergoing continental subduction: 1ƒan increase in the margin strength due to an increase in the confining pressure during the first million years of the margin subduction and 2ƒthe progressive heating of the subducted margin from the overlying lithosphere leads to a decrease in the margin strength due to thermal weakening, which progressively counter-balances the increase in confining pressure. Two strength gradients develop within the subducted lithosphere: 1ƒalong the slab, the strength decreases with increasing burial depth and 2ƒperpendicular to the slab, the strength increases with depth due to an inverse temperature distribution. The detachment of HPLT continental units from the subducted margin could occur when the slab strength becomes lower than the applied net stress. This allows the detachment of ductile weakened thin and long upper-crustal units. The thickness and length of the detached crustal units are controlled by the following parameters, in order of their importance: subduction dip angle, crustal rheology, mantle heat flux and subduction velocity. The comparison of our model results with the geometry and PT conditions of the Adula unit yields an estimate of the Alpine subduction dip angle at the time of deformation and metamorphism.
Modelling and spatial discrimination of small mammal assemblages: An example from western Sichuan (China)
29 avril 2009
We investigate the relationship between landscape heterogeneity and the spatial distribution of small mammals in two areas of Western Sichuan, China. Given a large diversity of species trapped within a large number of habitats,we first classified small mammal assemblages and then modelled the habitat of each in the space of quantitative environmental descriptors. Our original two step “classify then model” procedure is appropriate for the frequently encountered study scenario: trapping data collected in remote areas with sampling guided by expert field knowledge. In the classification step, we defined assemblages by grouping sites of similar species composition and relative densities using an expert-class-merging procedure which reduced redundancy in the habitat factor used within a multinomial logistic regression predicting species trapping probabilities. Assemblages were thus defined as mixtures of small mammal frequency distributions in discrete groups of sampled sites. In the modelling step, assemblages' habitats and environments of the two sampled areas were discriminated in the space of remotely sensed environmental descriptors. First, we compared the discrimination of assemblage/study areas by linear and non-linear forms of discriminant analysis (linear discriminant analysis versus mixture discriminant analysis) and of multiple regression (generalized linear models versus multiple adaptive regression splines). The “best” predictive modelling technique was then used to quantify the contribution of each environmental variable in discriminations of assemblages and areas. Mixtures of Gaussians provided a more efficient model of assemblage coverage in environmental space than a single Gaussian cluster model. However, non-linearity in assemblage response to environmental gradients was consistently predicted with lower deviance and misclassification error by multiple adaptive regression splines. The two study areas were mainly discriminated along vegetation indices. However, although the normalized difference vegetation index (NDVI) could discriminate forested from non-forested habitats, its power to discriminate assemblages in Maerkang, where a greater diversity of forest habitat was observed, was seen to be limited, and in this case NDVI was outperformed by the enhanced vegetation index (EVI). Our analyses highlight previously unobserved differences between the environments and smallmammalcommunities oftwo fringe areas of the Tibetan plateauand suggests that a biogeographical approach is required to elucidate ecological processes in small mammal communities and to reduce extrapolation uncertainty in distribution mapping
Genetic diversity of the cestode Echinococcus multilocularis in red foxes at a continental scale in Europe
29 avril 2009
Background: Alveolar echinococcosis (AE) is a severe helminth disease affecting humans, which is caused by the fox tapeworm Echinococcus multilocularis. AE represents a serious public health issue in larger regions of China, Siberia and other regions in Asia. In Europe, a significant increase of prevalence since the 1990's is not only affecting the historically documented endemic area North of the Alps, but more recently also neighbouring regions previously not known to be endemic. The genetic diversity of the parasite population and respective distribution in Europe has now been investigated in view of generating a fine-tuned map of parasite variants occurring in Europe. This approach may serve as a model to study the parasite at a world-wide level. Methodology/Principle findings: The genetic diversity of E. multilocularis was assessed based upon the tandemly repeated microsatellite marker EmsB in association with matching fox host geographical positions. Our study demonstrated a higher genetic diversity in the endemic areas North of the Alps when compared to other areas. Conclusions/Significance: The study of the spatial distribution of E. multilocularis in Europe, based on 32 genetic clusters, suggests that Europe can be considered as a unique global focus of E. multilocularis, which can be schematically drawn as a central core located in Switzerland and Jura Swabe flanked by neighbouring regions where the parasite exhibits a lower genetic diversity. The transmission of the parasite into peripheral regions is governed by a “mainland-island” system. Moreover, the presence of similar genetic profiles in both zones indicated a founder event.
Reflectance as a predictor for rodent species in the semiarid landscape Llanos de Ojuelos México
25 avril 2009
Although Mexico's central arid and semiarid lands face numerous conservation problems, they have largely been neglected from conservation, despite their apparent biological importance. We studied the semiarid Llanos de Ojuelos, where the original plant communities of grasslands, shrublands, and patches of oaks have been modified strongly by cattle grazing and for cultivation, affecting animal populations and communities, as well as the landscape-level ecological dynamics. Very little about the populations of wild animals in the area and the processes underlying their distribution and dynamics is known. We focused on whether satellite information was useful to explain rodent distributions and abundances in this area with a complex landscape of diffuse plant communities. In the spring of 2008 we inventoried the rodents at 74 locations in the area, through the use of Sherman live-traps (40 traps during two nights, per site; total=5920 night-traps). We covered the major perennial vegetation types. The existence of a complex landscape of intergrading grasslands, Opuntia comunities and shrublands (dominated by Acacia, Mimosa, Dodonaea, and Quercus) of different types and composition creates rich habitat mosaic that promotes a rich rodent fauna. We captured 20 species of rodents (458 individuals), while richness was estimated at 21-25 species. Reithrodontomys fulvescens, Chaetodipus nelsoni, Dipodomys phillipsii, Peromyscus melanophrys, Peromyscus gratus, and Peromyscus difficilis were very common at our sites, while Chaetodipus pennicillatus, Liomys irroratus, Perognathus flavus, Dipodomys merriami, Reithrodontomys megalotis, Peromyscus boylii, Neotoma leucodon, Peromyscus eremicus, Dipodomys ordii, and Peromyscus manicultatus were common, and Neotoma goldmani, Chaetodipus hispidus, Onychomys arenarius, and Baiomys taylori were rare. To explore the value of satellite information to understand and predict the rodents' distributions, we derived reflectance data from all bands of a Landsat5 TM Image (5 March 2008) for each trapline's midpoint. We will compare each rodent species' abundance with this data as well as with the normalized difference vegetation index (NDVI) and tasseled cap transformations (TCs: brightness, greenness, and wetness). We will link rodent presence/absences to reflectance values through linear and non-linear discriminant analysis, as well as through general linear models and multiple adaptive regression splines. Satellite images classified following the best models will then be interpreted according to field expertise. As end results we expect to have a better understanding on the rodent species' ecology, an adequate image classification procedure, and potential distribution maps for the rodent species in the study area.
Habitat modelling of small mammals assemblages in Western Sichuan (China): from locally trained models at landscape scale to regional predictive mapping
25 avril 2009
Building predictive maps of assemblage habitat, a widely used method in conservation and landscape management, is based on fitting habitat model on a training area, corresponding to a limited region in the environmental space. Model predictive performances need to be robustly evaluated on test data set. This is often realized at the landscape level, i.e taking as test data set one part of the original sample or a resampling one. Predicting assemblage occurrences at a regional level requires a step further in the modelling validation stage: testing model extrapolation performances. We estimated and compared the predictive performances of two scales of predictive mapping of small mammals assemblages in a remote area of Sichuan province. Small mammal assemblages were defined in two distant areas and differed between both areas. Their habitats were modelled, predicted and mapped using ETM bands at two different spatial scales: local (in each area) versus regional (including both areas). While locally trained models provided large predictive errors on independent data sets, the regionally trained model more accurately predicted assemblage occurrences and could be considered at this state of the research as an appropriate method to map assemblage regionally.
Spatial ecology and transmission of a zoonotic helminth in Tibetan pastoralist communities
24 avril 2009
Human alveolar echinococcosis (AE) is a rare but potentially fatal zoonotic disease across the northern hemisphere, caused by hepatic infection with the larval stage of the fox tapeworm Echinococcus multilocularis. It is endemic in areas of western China and our collaborative studies showed major human disease foci in south Gansu, south Ningxia and in Tibetan areas of northwest Sichuan, with ultrasound prevalences from <1->14%. Risk factors included dog ownership and proximity of deforested scrub/grass landscape habitats for susceptible small mammal reservoir host populations (microtines, ochotonids). In Tibetan pastoral communities semi-domestic parasite transmission involving dogs was described and modelled. Spatial variation in village AE rates was also linked to occurrence of optimal habitats for small mammals in overgrazed and fenced pastures. Anthropogenic induced heterogeneity in landscapes at local scales provided a metastable focus for sustainable transmission at regional scales across the eastern Tibetan Plateau. A spatial-deterministic model was developed that linked infection pressure to dogs (β) (based on purge, coproELISA and coproPCR) with the ratio of optimal/marginal habitats (ROMPA) of key small mammal species (based on spatial analyses of trapping data and activity indices). The model explains transmission heterogeneity in recent and past (archived satellite data) endemic landscapes, and is being applied across the Plateau to predict potential zones of transmission outside the current study sites
Spatial modelling of small mammal distributions in relation to parasite transmission and long-term landscape change in western China
24 avril 2009
This research investigates the spatial distributions of small mammal species which act as intermediate host vectors for the parasitic tapeworm Echinococcus multilocularis which causes a significant burden of human disease in western China. Small mammal distributions are modelled in relation to landscape characteristics derived from Landsat TM and ETM+ datasets. Statistical models are used to identify the landscape variables influencing small mammal spatial distributions, and to describe the nature of these relationships. They are then used predictively to determine probable small mammal distributions over large areas. Assessment of landscape change over a twenty-four year period, and its impact on small mammal communities are modelled. Results indicate that Ochotona distributions are significantly related to the spatial distribution of the degraded grassland habitat. Long-term landscape change analysis showed that large scale landscape degradation has occurred at the Serxu site between 1977 and 2001, increasing the area of degraded grassland, and the probability of small mammal presence. Probability maps of small mammal distributions are produced, with potentially significant applications in the development of future disease control programmes
Integrating landscape ecology and epidemiology
24 avril 2009
Biological mechanisms known to affect space-time dynamics of infectious diseases may be impacted by ecosystem change and the last 50 years have seen the greatest changes in ecosystem structure and function in human history (Patz and Confalonieri 2005). Alveolar echinococcosis (AE) is a disease lethal to humans caused by a Cestod parasite. The parasite is transmitted through a life-cycle including small mammal intermediate hosts (rodents and lagomorphs) and carnivore definitive hosts, mostly foxes and domestic dogs. Over the last 15 years it appears that the parasite has spread its geographic range in the red fox populations of western and eastern Europe and large foci of AE have been discovered in Western China at the Eastern border of the Tibetan plateau. Transmission systems have been studied in eastern France and Western China combining quantified analysis of landscape changes, small mammal communities and AE prevalence in humans and foxes (Giraudoux et al. 2002; Giraudoux et al. 2006). Evidence has been provided that at the regional scale landscape can affect human disease distribution through interaction with small mammal communities and their population dynamics. Regional models have been proposed where satellite imagery was used to describe landscapes and evaluate transmission risk. Here we review those studies and discuss their results with perspectives for studies of pathogenic organism transmission grounded on systems approach and landscape ecology concepts.
Large calcite and bulk-rock volume loss in metacarbonate xenoliths from the Querigut massif (French Pyrénées).
24 avril 2009
High performance automated ion chromatography separation for Ca isotope measurements in multiple natural matrices
16 avril 2009
High-precision cadmium isotope measurements determined by double spike thermal ionisation mass spectrometry
16 avril 2009
Mass-dependent cadmium isotopic variations in nature with emphasis on the marine environment
16 avril 2009
Influence of watershed's anthropogenic activities on fish nitrogen and carbon stable isotope ratios in nine French lakes
27 mars 2009
The relationships between fish community delta15N and delta13C values and land use in watersheds and in buffer zones of nine French lakes were studied. The results showed inter-lakes variability of mean delta15N and delta13C values for different fish species. The study of correlations between fish delta15N and delta13C values and the proportions from different land use categories in watersheds showed a land use effect on fish delta15N values but not on delta13C values. The results underlined the great impact of manure spreading on grasslands as a nitrate source in our lakes. Nevertheless, the best correlations between fish delta15N values and land use were obtained when the entire fish community (i.e. the whole fish community mean delta15N values in each lake) and all anthropogenic activities (residential lands, camp sites and grasslands for our systems) were considered in either watersheds or in buffer zones. Thus, for our sites, the fish delta15N values are useful to evaluate nitrogen inputs from human and animal wastes at the watershed-scale as well as at the buffer zone-scale. The absence of land use effect on the fish community delta13C values could be at least partly explain by the great importance of heterotrophic activity in the studied lakes.