Éditeur(s) : HAL CCSD Ecological Society of America
Résumé : Herbivores are often implicated in the generation of the extraordinarily diverse tropical flora. One hypothesis linking enemies to plant diversification posits that the evolution of novel defenses allows plants to escape their enemies and expand their ranges. When range expansion involves entering a new habitat type, this could accelerate defense evolution if habitats contain different assemblages of herbivores and/or divergent resource availabilities that affect plant defense allocation. We evaluated this hypothesis by investigating two sister habitat specialist ecotypes of Protium subserratum (Burseraceae), a common Amazonian tree that occurs in white-sand and terra firme forests. We collected insect herbivores feeding on the plants, assessed whether growth differences between habitats were genetically based using a reciprocal transplant experiment, and sampled multiple populations of both lineages for defense chemistry. Protium subserratum plants were attacked mainly by chrysomelid beetles and cicadellid hemipterans. Assemblages of insect herbivores were dissimilar between populations of ecotypes from different habitats, as well as from the same habitat 100 km distant. Populations from terra firme habitats grew significantly faster than white-sand populations; they were taller, produced more leaf area, and had more chlorophyll. White-sand populations expressed more dry mass of secondary compounds and accumulated more flavone glycosides and oxidized terpenes, whereas terra firme populations produced a coumaroylquinic acid that was absent from white-sand populations. We interpret these results as strong evidence that herbivores and resource availability select for divergent types and amounts of defense investment in white-sand and terra firme lineages of Protium subserratum, which may contribute to habitat-mediated speciation in these trees.
ISSN: 0012-9658

hal-01032403
https://hal.archives-ouvertes.fr/hal-01032403
DOI : 10.1890/12-1920.1

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Among pregnant women ibuprofen is one of the most frequently used pharmaceutical compounds with up to 28% reporting use. Regardless of this, it remains unknown whether ibuprofen could act as an endocrine disruptor as reported for fellow analgesics paracetamol and aspirin. To investigate this, we exposed human fetal testes (7-17 gestational weeks (GW)) to ibuprofen using ex vivo culture and xenograft systems. Ibuprofen suppressed testosterone and Leydig cell hormone INSL3 during culture of 8-9 GW fetal testes with concomitant reduction in expression of the steroidogenic enzymes CYP11A1, CYP17A1 and HSD17B3, and of INSL3. Testosterone was not suppressed in testes from fetuses younger than 8 GW, older than 10-12 GW, or in second trimester xenografted testes (14-17 GW). Ex vivo, ibuprofen also affected Sertoli cell by suppressing AMH production and mRNA expression of AMH, SOX9, DHH, and COL2A1. While PGE2 production was suppressed by ibuprofen, PGD2 production was not. Germ cell transcripts POU5F1, TFAP2C, LIN28A, ALPP and KIT were also reduced by ibuprofen. We conclude that, at concentrations relevant to human exposure and within a particular narrow â €' early window' of sensitivity within first trimester, ibuprofen causes direct endocrine disturbances in the human fetal testis and alteration of the germ cell biology. © The Author(s) 2017.
ISSN: 2045-2322

hal-01517095
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01517095
DOI : 10.1038/srep44184
PUBMED : 28281692

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé :  
Cross-species analyses of plant functional traits have shed light on factors contributing to differences in performance and distribution, but to date most studies have focused on either leaves or stems. We extend these tissue-specific analyses of functional strategy towards a whole-plant approach by integrating data on functional traits for 13 448 leaves and wood tissues from 4672 trees representing 668 species of Neotropical trees. Strong correlations amongst traits previously defined as the leaf economics spectrum reflect a tradeoff between investments in productive leaves with rapid turnover vs. costly physical leaf structure with a long revenue stream. A second axis of variation, the 'stem economics spectrum', defines a similar tradeoff at the stem level: dense wood vs. high wood water content and thick bark. Most importantly, these two axes are orthogonal, suggesting that tradeoffs operate independently at the leaf and at the stem levels. By simplifying the multivariate ecological strategies of tropical trees into positions along these two spectra, our results provide a basis to improve global vegetation models predicting responses of tropical forests to global change.
Ecology Letters

hal-01032142
https://hal.archives-ouvertes.fr/hal-01032142
DOI : 10.1111/j.1461-0248.2010.01517.x

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Amelotin (AMTN) is an ameloblast-secreted protein that belongs to the secretory calcium-binding phosphoprotein family, which also includes the enamel matrix proteins amelogenin, ameloblastin and enamelin. Although AMTN is supposed to play an important role in enamel formation, data were long limited to the rodents, in which it is expressed during the maturation stage. Recent comparative studies in sauropsids and amphibians revealed that (i) AMTN was expressed earlier, i.e. as soon as ameloblasts are depositing the enamel matrix, and (ii) AMTN structure was different, a change which mostly resulted from an intraexonic splicing in the large exon 8 of an ancestral mammal. The present study was performed to know whether the differences in AMTN structure and expression in rodents compared to non-mammalian tetrapods dated back to an early ancestral mammal or were acquired later in mammalian evolution. We sequenced, assembled and screened the jaw transcriptome of a neonate opossum Monodelphis domestica, a marsupial. We found two AMTN transcripts. Variant 1, representing 70.8% of AMTN transcripts, displayed the structure known in rodents, whereas variant 2 (29.2%) exhibited the nonmammalian tetrapod structure. Then, we studied AMTN expression during amelogenesis in a neonate specimen. We obtained similar data as those reported in rodents. These findings indicate that more than 180 million years ago, before the divergence of marsupials and placentals, changes occurred in AMTN function and structure. The spatiotemporal expression was delayed to the maturation stage of amelogenesis and the intraexonic splicing gave rise to isoform 1, encoded by variant 1 and lacking the RGD motif. The ancestral isoform 2, housing the RGD, was initially conserved, as demonstrated here in a marsupial, then secondarily lost in the placental lineages. These findings bring new elements towards our understanding of the non-prismatic to prismatic enamel transition that occurred at the onset of mammals.
ISSN: 1932-6203

Droits : http://creativecommons.org/licenses/by/
hal-01233552
https://hal.archives-ouvertes.fr/hal-01233552
https://hal.archives-ouvertes.fr/hal-01233552/document
https://hal.archives-ouvertes.fr/hal-01233552/file/journal.pone.0133314.pdf
DOI : 10.1371/journal.pone.0133314

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The barrier reef tract of New Caledonia is the second largest in the world enclosing lagoons of variable width. The Late Quaternary evolution of these barrier reefs and lagoons is poorly known. A recent high resolution seismic and multibeam bathymetry survey was carried out in the south-western lagoon from shoreline to open ocean across the barrier reef pass systems to perform sequence stratigraphy and to better understand the Quaternary evolution of the lagoon. Two depositional sequences bounded by type-1 erosional surfaces can be identified. The bounding surfaces delineate the bottom of two generations of incised valleys. System tracts comprising a complete succession of regressive, lowstand, transgressive and highstand tracts were observed only in the upper sequence. Chronostratigraphic and sedimentological interpretations of the seismic data are based on correlations with the chronology defined in the nearby cores drilled through the reefs and in the gravity cores previously recovered in the inner lagoon. Interpretation of seismic data is also carried out on the basis of correlation with multibeam bathymetric data. Our results indicate that the history of the New Caledonian lagoon probably does not exceed 200ka marked by two or three brief episodes each of immersion of about ten thousand years. The bathymetric data reveal that during successive low sea level stands, the lagoon was dependent upon erosional fluvial networks. The deep fluvial valleys were connected to the continental slope through the passes. Seismic records reveal that upstream palaeo-channels are not connected to the modern coastal rivers. In contrast, many aggrading deposits, including numerous stacking channels, and extending across the proximal part of the outer lagoon, can be identified. Examination of drainage network morphology suggests a progressive tilt of the outer lagoon. Such evolution reveals that the Nouméa lagoon which is one of the widest in the world is an exceptional modern example of a rimmed shelf providing data to analyze the past counterparts.
ISSN: 0031-0182

insu-00338953
https://hal-insu.archives-ouvertes.fr/insu-00338953
DOI : 10.1016/j.palaeo.2008.08.012

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The basement of central Madagascar displays two contrasted structural patterns. The first one (D1) is characterized by north-striking foliations that are gently dipping to the west and carry W- to WSW-plunging lineations, whereas the second one (D2) is characterized by steeper foliations that are striking to the NNE and lineations that are either subhorizontal or gently plunging to the SSW. The younger pattern is related to late-Panafrican tectonics along the major Angavo shear zone that is about 1000 km in length and 40 km in width with apparently little offset. Deformation in the Angavo zone induced interference folding on both sides. The D2 event is characterized by low pressures (ca 400 MPa) and high temperatures (up to 790 degrees C) responsible for prograde granulite facies conditions, that resulted from heat transfer due to magma and fluid advection in the Angavo shear zone. The D2 event is pinned at 550 +/- 11 Ma by a new monazite age from a reoriented Andringitrean granite near Ankaramena. A new suite of amphibole and biotite Ar-Ar geochronological data enables to retrace the thermochronogical evolution inside and outside the Angavo shear zone. Combined with new structural results from the western interference zone. these ages yield a better understanding of the late-Panafrican history of central Madagascar. No diachronism is observed along the strike of the Angavo shear zone. Conversely, amphibole and especially biotite ages decrease from West to East, i.e. towards the shear zone. These new ages range from 511 to 469 Ma. A 1-D conductive model constrains the thermal effect in relation with the Angavo shear zone to be restricted to a lateral distance of ca 60 km (in map view) for a maximum heating duration of 20 Myr. This is in agreement with the Ar-Ar data and with the width of the observed interference zone. Following this episode of deformation and heat transfer, the estimated cooling rates of the Angavo shear zone range from to 15 to 6 degrees C/Myr, respectively before and after 515 Ma. A post-collision intracontinental setting is suggested for the Angavo shear zone, which is regarded as a remote effect of the Kuunga Orogeny between India and Antarctica.
ISSN: 0040-1951

hal-00463507
https://hal.archives-ouvertes.fr/hal-00463507
DOI : 10.1016/j.tecto.2009.03.009

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The present study aims at better deciphering the different mechanisms involved in the functioning of the subduction interplate. A 2D thermo-mechanical model is used to simulate a subduction channel, made of oceanic crust, free to evolve. Convergence at constant rate is imposed under a 100 km thick upper plate. Pseudo-brittle and non-Newtonian behaviours are modelled. The influence of the subduction channel strength, parameterized by the difference in activation energy between crust and mantle () is investigated to examine in detail the variations in depth of the subduction plane down-dip extent, . First, simulations show that numerical resolution may be responsible for an artificial and significant shallowing of if the weak crustal layer is not correctly resolved. Second, if the age of the subducting plate is 100 Myr, subduction occurs for any . The stiffer the crust is, that is, the lower is, the shallower is (60 km depth if kJ/mol) and the hotter the fore-arc base is. Conversely, imposing a very weak subduction channel ( J/mol) leads there to an extreme mantle wedge cooling and inhibits mantle melting in wet conditions. Partial kinematic coupling at the fore-arc base occurs if kJ/mol. If the incoming plate is 20 Myr old, subduction can occur under the conditions that the crust is either stiff and denser than the mantle, or weak and buoyant. In the latter condition, cold crust plumes rise from the subduction channel and ascend through the upper lithosphere, triggering (1) partial kinematic coupling under the fore-arc, (2) fore-arc lithosphere cooling, and (3) partial or complete hindrance of wet mantle melting. then ranges from 50 to more than 250 km depth and is time-dependent if crust plumes form. Finally, subduction plane dynamics is intimately linked to the regime of subduction-induced corner flow. Two different intervals of are underlined: 80–120 kJ/mol to reproduce the range of slab surface temperature inferred from geothermometry, and 10–40 kJ/mol to reproduce the shallow hot mantle wedge core inferred from conditions of last equilibration of near-primary arc magmas and seismic tomographies. Therefore, an extra process controlling mantle wedge dynamics is needed to satisfy simultaneously the aforementioned observations. A mantle viscosity reduction, by a factor 4–20, caused by metasomatism in the mantle wedge is proposed. From these results, I conclude that the subduction channel down-dip extent, , should depend on the subduction setting, to be consistent with the observed variability of sub-arc depths of the subducting plate surface.
ISSN: 0031-9201

hal-01623155
https://hal.archives-ouvertes.fr/hal-01623155
DOI : 10.1016/j.pepi.2017.05.008

Éditeur(s) : HAL CCSD
Résumé : Given a set of strings, the Common Subsequence Automaton accepts all common subsequences of these strings. Such an automaton can be deduced from other automata like the Directed Acyclic Subsequence Graph or the Subsequence Automaton. In this paper, we introduce some new issues in text algorithm on the basis of Common Subsequences related problems. Firstly, we make an overview of different existing automata, focusing on their similarities and differences. Secondly, we present a new automaton, the Constrained Subsequence Automaton, which extends the Common Subsequence Automaton, by adding an integer $q$ denoted quorum.
https://hal.inria.fr/inria-00257561

inria-00257561
https://hal.inria.fr/inria-00257561
https://hal.inria.fr/inria-00257561/document
https://hal.inria.fr/inria-00257561/file/CSAq.pdf

Résumé : Les aciers inoxydables à haute teneur en molybdène présentent une excellente résistance à la corrosion et ont été récemment utilisés dans des applications marines. L'acier inoxydable de type 254 SMO contient du molybdène (6% Mo) et des quantités plus élevées en éléments d'alliages que les aciers inoxydables plus classiques tels que 304, 316 et 316L. Alors que Anees Uddin Malik et al. montrent que l’acier 254 SMO est moins sensible à la corrosion par piqûre en eau de mer du golfe persique, Abdulsalam et al. démontrent que bien que cet acier présente une bonne résistance à la corrosion, il reste encore sensible à une corrosion caverneuse (surtout en milieu à 16% en masse d’ion chlorure ou à plus de 30°C).La première partie de ce travail traite du comportement électrochimique de l’acier inoxydable 254 SMO immergé dans l’eau de mer naturelle en laboratoire. Ainsi deux sites de la Guyane ont été choisis pour effectuer des prélèvements d’eau. Des analyses physicochimiques de ces eaux sont réalisées et montrent que l’eau du site du Port Larivot contient une quantité en ions chlorures plus importante que celle de l’eau du site du Mahury. Une colonisation par des bactéries et crustacés (balanes) a été mise en évidence, à l’aide du microscope électronique à balayage environnemental. Les mesures électrochimiques, notamment la voltammétrie cyclique a montré l’existence d’une zone de passivation et l’augmentation du courant de passivation par un facteur de 10 en présence d’un biofilm pour l’acier inoxydable immergé en eau du Mahury durant 22 jours. La deuxième partie propose une étude approfondie du comportement de l’interface complexe métal/couche passive/biofilm. Trois différents coupons d’aciers inoxydables (brut, poli et grenaillé) ont été déposés sur site (in-situ) dans un premier temps. Dans une seconde étape, nous avons réalisé des expérimentations mixtes (incubation in-situ et croissance en laboratoire). L’évolution du potentiel d’abandon de ces aciers est très proche pour l’acier brut et l’acier poli. En revanche, celui de l’acier grenaillé, de par la présence des grains d’alumine à sa surface, affiche un comportement différent. Une étude comparative des deux expérimentations montre des différences concernant les paramètres électriques de l’interface complexe métal/couche passive/biofilm.
Stainless steels with high content in molybdenum present an excellent corrosion resistance and were recently used in marine applications. The stainless steel 254 SMO contains molybdenum (6 %) and higher amounts of alloying elements than conventional stainless steels such as 304, 316 and 316L. While Anees Uddin Malik et al. show that 254 SMO steel is less likely to be susceptible to pitting corrosion in Arabian Gulf sea water, Abdulsalam et al. demonstrate that although this steel has good resistance to corrosion, it remains still susceptible to crevice corrosion (especially in environment with 16 chloride percent weight or more than 30 ° C).The first part of this work deals with the electrochemical behaviour of stainless steel 254 SMO immersed in natural seawater at laboratory. Two sites in French Guyane were chosen to take samples of seawater. Physicochemical analyses of these waters are made and show than the in Port Larivot site seawater contains a higher quantity of chloride ion than to Mahury seawater. Colonization by bacteria and crustaceans (barnacles) was highlighted, using the environmental scanning electron microscope. The electrochemical measurements, including cyclic voltammetry showed the existence of a passivation region and increasing the passivation current by a factor of 10 in the presence of biofilm on stainless steel immersed in Mahury seawater during 22 days.The second part offers a detailed study of the behaviour of the interface metal/passive film/biofilm. Three different coupons of stainless steel (crude, polished and blasted) were deposited on the site (in-situ) in the first time. In a second step, we performed experiments mixed (in-situ incubation and growth in the laboratory). The evolution of the free potential of these steels is very close for crude steel and polished steel. Conversely, the blasted steel, by the presence of alumina grains on its surface, shows a different behaviour. A comparative study of those two experiments shows differences in the electrical parameters of the interface metal/passive film/biofilm.

http://www.theses.fr/2013AGUY0598/document

Éditeur(s) : HAL CCSD Springer-Verlag
Résumé : International audience
High-resolution borehole strainmeters are usually installed in tectonically active regions in order to detect slow-slip events, and to estimate slow transients related to earthquake swarms. However, they are also sensitive to other numerous influences, internal or external. Furthermore, the quality of their coupling to the rock through cementation, and the mechanical properties of the rock mass around them, have a critical influence on their records. Many of the existing strainmeters present such problems, and the correction for these effects often remains a challenge. In this paper, we present the analysis of the records of a high-resolution borehole dilatometer (Sacks–Evertson), located in the seismically active rift of Corinth (Greece) (station TRZ in the Trizonia island). We show that the instrument suffers from an only partial-solid coupling, and that the nearby sea tides have a direct (through elastic response) and indirect (through pore-pressure diffusion) effect on the dilatation signal, which adds up to the solid tidal strain source. We propose a methodology that allows, in a first step, to better separate the internal (solid tide) from the external (air pressure, sea level) influences, by calculating a frequency-dependent transfer function outside the range of the tidal periods. We then extrapolate this function, in particular at the tidal periods. In a second step, the resulting variation with frequency of the coupling coefficients with sea level led us to estimate the proportion of instrument not solidly cemented to rock (thus in contact with water pore pressure), which is about 90 % of the total height. Despite the small proportion of solid coupling, the sensor resolution remains very good up to a few tens of hours of a time period, thanks to the confining effects of the rocks on the local pore pressure. These results allow us to correct for the external effects, and reduce the associated variance by 80–90 % (in the period range of minutes to days). The empirical correction of the sea level effect could be explained using a simple Boussinesq’s approximation and 1D pore-pressure diffusion model, which contributed to better constraint of some of the poro-elastic parameters in the vicinity of the instrument. After correction, the solid tidal signal at the 24-h period is almost anti-correlated with those of the theoretical solid tide. This surprising result is consistent with a similar anti-correlation observed for the longest period surface waves (200 s) comparing the TRZ dilatometer signals to the strain measured by a nearby borehole strainmeter (MOK, 15 km). This could be related to the presence of a shallow fault close to the instrument, which would creep in response to seismic wave-related stress.
ISSN: 0033-4533

hal-01122853
https://hal.archives-ouvertes.fr/hal-01122853
DOI : 10.1007/s00024-013-0742-2

Éditeur(s) : HAL CCSD American Society for Microbiology
Résumé : International audience
Coronaviruses (CoVs) have shown neuroinvasive properties in human and animal secondary to replication in peripheral organ but the mechanism of neuroinvasion is unknown. The major aim of our work was to evaluate the ability of CoVs to enter the central nervous system (CNS) through the blood brain barrier (BBB). Using the high hepatotropic mouse hepatitis virus (MHV) type 3, its attenuated variant 51.6-MHV3, showing low tropism for endothelial cells, and the low hepatotropic MHV-A59 strains from murine coronavirus group, we investigated the viral-induced dysfunctions of BBB in vivo and in brain microvascular endothelial cells (BMECs) in vitro. We report here a MHV strain-specific ability to cross the BBB during acute infection according to their virulence for liver. Brain invasion was only observed in MHV3-infected mice and correlated with enhanced BBB permeability associated with decreased expression of ZO-1, VE-cadherin and occludin but not claudin-5 in the brain or in cultured BMECs. BBB breakdown in MHV3 infection was not related to production of barrier-dysregulating inflammatory cytokines or chemokines by infected BMECs but rather to a downregulation of barrier protective IFN-β production. Our findings highlight the importance of IFN-β production by infected BMECs in preserving BBB function and preventing access of blood-borne infectious viruses to the brain. IMPORTANCE: Coronaviruses (CoVs) infect several mammals including humans and are associated with respiratory, gastrointestinal and/or neurological diseases. Some evidences suggest that human respiratory CoVs may show neuroinvasive properties. Indeed, the SARS-CoV, causing severe acute respiratory syndrome, and the CoVs OC43 and 229E were found in the brains of SARS and multiple sclerosis patients respectively. These finding suggest that hematogenous spread CoVs may gain access to CNS at the BBB level. Herein we report for the first time that CoVs exhibit ability to cross the BBB according to strain virulence. BBB invasion by CoVs correlates with viral-induced disruption of tight junctions on BMECs, leading to BBB dysfunction and enhanced permeability. We provide evidence that production of IFN-β by BMECs during CoV infection may prevent BBB breakdown and brain viral invasion
ISSN: 0022-538X

hal-01187308
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187308
DOI : 10.1128/JVI.01501-15
PUBMED : 26202229

Éditeur(s) : HAL CCSD
Résumé : International audience
The aboveground biomass density (AGBD) or aboveground carbon density is mapped for the rainforest of the Basse-Terre Island (Guadeloupe, French West Indies). This mapping is the first devoted to the rainforest of the Lesser Antilles.Mapping AGBD needs the successive realization of two steps. At first, AGBD was estimated in studied forest plots where trees were individually measured; secondly these local estimations were extended through multiple regression including remote sensing LiDAR measurements.Due to the structural specificity of the Caribbean-islands forests, applying general allometry relationship overestimates tree above-ground biomass. Yet we take advantage of pantropical database (Chave et al. 2014) by adopting a suitable statistical procedure: bayesian mixed decision rule.Despite the reduced canopy height, generally less than 35 m, Caribbean lowland rainforests have a high biomass, in every respect comparable to that of continental lowland forests. Such peculiarity is achieved through increased tree density that compensate for lower canopy height.
CAS
Deshaies, Guadeloupe

hal-01514241
https://hal.archives-ouvertes.fr/hal-01514241

Éditeur(s) : HAL CCSD
Résumé : Taiwan is a young mountain belt, known as one of the most active area in the world. Since the beginning of the 20th century more than twenty _ Mw 7 earthquakes have struck the island. However, the occurrence of larger events (_Mw 8) is still a matter of debate. In this framework it is of key importance to obtain longer record in order to evaluate the occurrence of large past earthquakes. The sub-aqueous paleoseismology, based on the record of the sedimentary gravity deposits, appears as a serious alternative to approach this thematic and is a rapidly advancing field that has the potential to illuminate the long-term history of seismicity.The first part of this work was to investigate the present sedimentary systems off east Taiwan, essential to understand the morphosedimentary features, sedimentary facies and processes governing the evolution of the submarine slope, and the controlling factors of the recent sedimentation. Our results showed that the offshore slope east Taiwan is affected by a variety of sedimentary systems and processes, and that turbidity currents appear as the main erosional processes covering nearly 60% of the sedimentary record. Turbidity currents are generated by distinct controlling factors such as tectonic and climatic activity that enabled us to define twoend-members relative to turbidity currents initiation: Turbidity currents preconditioned by tectonic activity and triggered by earthquakes shaking and likely deposited into intra-slope basin and turbidity currents driven by climatic activity such as extreme floods or typhoons, generated in basin directly connected with onland rivers.The second part consisted to apply a paleoseismic approach, based on turbidites record, at two time-scales. First, we tested and validated the method by correlating turbidites deposits with instrumental earthquakes. Then, once calibrated we extended the time-series back in time. We dated the three most recent turbidites layers circa 2001 ± 3 AD, 1950 ± 5 AD and 1928 ± 10 AD. Using empirical relationship that link peakground acceleration, distance and magnitude to calibrate the seismic sources, we correlate these three turbidites with instrumental earthquakes: the Chengkong Earthquake 12/10/2003 (Mw 6.8), the 11/24/1951 Taitung Earthquake (Mw 7.1) and the 9/4/1935 Lutao Earthquake (Mw 7.0) respectively. Applying criteria to discriminating the different triggering mechanisms for turbidity current generation, we propose that earthquakes are the main triggering mechanisms. Dating and age modeling provided a part of the chronology of extreme events since the last 3000 years and allowed us to estimate return time for earthquakes Mw _ 6.8.This work represents a good starting-point for future investigations in order to better assess Holocene time series of extreme events.
La chaine de Taïwan représente l’une des zones les plus actives au monde. Depuis le début du XXe siècle, plus d’une vingtaine de séismes _Mw 7 ont affecté l’île. Cependant la probabilité d’occurrence de séismes plus importants (_Mw 8) est toujours matière à débat. Dans un tel contexte, il apparait donc important d’obtenir des enregistrements plus anciens pour évaluer l’occurrence de tels évènements. La paléosismologie marine, basée sur l’enregistrement des dépôts issus de la sédimentation gravitaire, apparait comme une alternative sérieuse afin d’illuminer l’histoire de la sismicité sur des périodes anciennes. Ce travail de thèse apporte de nouvelles contraintes sur l’histoire sismique au large, à l’est de Taïwan, au cours des derniers 3000 ans.La première partie de ce travail consiste à caractériser les systèmes sédimentaires récents. Cette étape fut essentielle pour la compréhension des processus, faciès sédimentaires et les facteurs de contrôle de la sédimentation qui régissent l’évolution de la pente sous-marine. Ces résultats ont montré que l’Est de Taïwan est caractérisé par une grande variabilité de processus et que les courants de turbidité dominent l’enregistrement sédimentaire.Les courants de turbidité sont générés par deux facteurs distincts : l’activité tectonique/sismique et l’activité climatique. La deuxième partie de ce travail est consacrée à l’approche paléosismique en utilisant les dépôts de turbidités comme marqueurs des paléoséismes. Pour ce faire, nous avons dans un premier temps testé et validé l’approche à l’échelle du siècle dernier. Ensuite une fois calibré, nous avons pu étendre les séries temporelles à l’échelle de l’Holocène. Nous avons daté les trois plus récents évènements turbiditiques autour de 2001 ± 3 AD, 1950 ± 5 AD et 1928 ± 10 AD. En utilisant des relations empiriques intégrant magnitude, distance et valeur du "peak ground acceleration", nous avons pu calibrer la source sismique et ainsi corréler ces trois turbidites à trois séismes instrumentaux : le séisme de Chengkong (12/10/2003) (Mw 6.8), le séisme de Taitung (11/24/1951) (Mw 7.1) et le séisme de Lutao (9/4/1935) (Mw 7.0). Au-delà du siècle dernier, les datations et modèles d’âges nous permettent d’établir une partie de la chronologie des évènements extrêmes sur une période de 3000 ans et d’estimer un temps de retour pour des évènements de l’ordre _Mw 7. Les résultats ont toutefois montré que ces temps de retour sont nettement supérieurs à ceux connus sur le siècle dernier, ce qui suggère que tous les séismes ne sont pas enregistrés par les dépôts sédimentaires marins. Ce travail de thèse a donc permis de montrer que les dépôts issus de la sédimentation évènementielle peuvent être considérés comme marqueurs de la sismicité et que cette approche peut constituer un outil complémentaire pour les études portant sur le risque sismique.
https://tel.archives-ouvertes.fr/tel-01661529

NNT : 2014MON20133
tel-01661529
https://tel.archives-ouvertes.fr/tel-01661529
https://tel.archives-ouvertes.fr/tel-01661529/document
https://tel.archives-ouvertes.fr/tel-01661529/file/55796_LEHU_2014_archivage_cor.pdf

Éditeur(s) : HAL CCSD IOS Press
Résumé : The main objectives of the present work were to test the effects of heat stress on blood rheology and to determine whether the responses can change according to the pig breeds. Thirty-six pigs from three pig's lines (n = 12 for each line) with assumed different tolerance to heat stress were compared: Large White (LW, little tolerance), Creole (CR, good tolerance) and LW × CR pigs (produced from a cross between LW and CR lines). In a first period, all pigs were exposed to a 9-d period of thermo-neutral environment (24°C; d-9 to d-1; P0). At the end of P0, six pigs from each line were slaughtered (n = 18). Then in a second period, the remaining pigs (6/breed; n = 18) were exposed to a 5-d period of heat stress (32°C; d + 1 -d + 5; P1) and thereafter slaughtered at d + 5. Rectal and skin temperatures, as well as respiratory rate, were recorded on d-1 and d + 5. At slaughter, blood was sampled for hematological and hemorheological measurements. Heat stress caused a rise of the skin temperature and respiratory rate without any changes in the rectal temperature or on the hematological and hemorheological parameters when all pigs' lines were considered. We observed a pig line effect on blood viscosity at high shear rate (375 s-1) and red blood cell deformability at 30 Pa with CR pigs having lower blood viscosity and higher red blood cell deformability than LW pigs. While the changes of blood viscosity under heat stress did not reach statistical significance in LW and CR lines, blood viscosity (at 375 s-1) increased above the temperate values in the LW × CR line. Red blood cell deformability at 30 Pa was higher in CR pigs exposed to heat stress compared to LW pigs in the same condition. In conclusion, thermal loading caused physiological stress but did not widely change the hematological and hemorheological profiles. Although some blood rheological parameters seem to vary with the pig breeds, the responses to heat stress are very similar.
ISSN: 1386-0291

hal-01210926
https://hal.archives-ouvertes.fr/hal-01210926
DOI : 10.3233/CH-131722
PRODINRA : 286489
PUBMED : 23603327

Éditeur(s) : Gauthier-Villars
Résumé : In the sedimentary areas surrounding the Florida Keys, Soritidae and Peneroplidae are very well represented. These benthic foraminifera are generally attached to seagrasses or algae and more rarely to carbonate deposits. The colouring of their protoplasm results from the nature of endosymbiotic algae. The principal species represented are: Androsina lucasi (never recorded before in Florida) which lives only in the margino-littoral biotopes where the salinity is highly variable; Archaias angulatus and Amphisorus hemprichii which live in the biotopes of the littoral platform but also in those of the interior margin of the bay where the variations of salinity are weak; Cyclorbiculina compressa and Peneroplis proteus which live for the main part in the littoral biotopes of the oceanic platform where the salinity is normal and quite constant; five other species of secondary importance take the number of taxa observed alive in the Keys area up to ten. Moreover, if the comparison of the biocenoses and thanatocenoses emphasizes their comparative similitude, knowledge of the biocenoses permits a better understanding of their adaptation to present-day environments.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1991 , Vol. 14 , N. 5 , P. 515-524

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00103/21379/18979.pdf
http://archimer.ifremer.fr/doc/00103/21379/

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

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

Éditeur(s) : HAL CCSD
Résumé : This study is designed to improve the understanding of structural, mechanical and petrophysical characteristics of deformation bands in porous sandstone such as their potential influence on fluid storage or migration in reservoir setting. Structural and petrophysical analysis of band networks from Provence show that permeability of band is mainly controlled by the degree of cataclasis and diagenetic processes at depth. Map-scale analysis of band networks underlines the major influence of tectonic regime on band distribution, organization and permeability. Band associated to normal-fault regime (cataclasis and low-permeability) are located around map-sclae-fault whereas band associated to thurst-fault regime (moderate cataclasis and permeability) are pervasively distributed in all the area. Reverse-sense band are cataclastic and low-permeabiilty around the Roquemaure thrust, which show the potential role of large-scale fault on structural and petrophysical characteristics of bands. This analysis also shows the influence of fault propagation on formation of low permeability catacastic bands. This analysis suggests also granulometry as factor controlling organization of band networks.A mechanical analysis of deformation bands is realized based on results from Provence. Yield envelopes of these materials are calculated from analytical solution. Triaxial tests done on sandstone (L'Etang quarry, Orange) confirm the shape of yield envelope theoretically calculated. Triaxial tests done on the poorly-lithified sands (Boncavaï quarry, Uchaux) show grain size, sorting and packing influencing yield envelope and cataclastic band localization at shallow burial depth. Stress paths are calculated for burial and tectonic event (extension and contraction) using the relationship between main stress and secondary stresses (K0) calibrated from well data. These different results are integrated into a model which allows to estimate type and structural characteristics of bands susceptible to form for a known geological setting.A structural, mechanical and petrophysical model is established form these results. This model is calibrated by permeability data from deformation bands of Provence and results from the mechanical model of strain localization. This model is also confronted to a synthesis of permeability data from literature, which confirms the influence of the different controlling parameters integrated to the model. This model is applied for two sites of uranium exploration/exploitation in porous sandstone reservoirs and validated by field observations.
Cette étude est destinée à améliorer la compréhension des caractéristiques structurales, pétrophysiques et mécaniques des bandes de déformation dans les grès poreux ainsi que de leur rôle potentiel sur la migration ou le piégeage des fluides en milieu réservoir. L'analyse structurale et pétrophysique des réseaux de bandes de Provence montre que leur perméabilité découle principalement de l'intensité de la cataclase dans leur microstructure et des processus diagénétiques qui peuvent s'y localiser avec la profondeur. L'analyse régionale de ces réseaux de bandes souligne l'influence majeure du régime tectonique sur leur distribution, leur organisation et leur perméabilité. Les bandes associées au régime normal (cataclactiques et peu perméables) sont localisées autour des failles cartographiques, tandis que les bandes associées au régime inverse (modérement cataclastiques et perméables) sont distribuées dans toute la région. Les bandes inverses sont fortement cataclastiques et imperméables uniquement autour du chevauchement de Roquemaure ce qui montre le rôle potentiel de la présence de grande faille sur les caractéristiques structurales et pétrophysiques de ces bandes. D'autre part, cette analyse suggère que la granulométrie de l'encaissant peut influencer l'initiation et l'organisation des réseaux. L'analyse mécanique des bandes de déformation a ensuite été réalisée à partir des résultats obtenus en Provence. L'enveloppe de plasticité de ces matériaux est calculée à l'aide d'une solution analytique. Les essais triaxiaux menés sur le grès de la carrière de l'Etang (orange) confirment la forme de ces enveloppes estimées théoriquement. Les essais réalisés sur les sables de Boncavaï (Uchaux) montrent que la taille des grains, le tri et de la compaction dans ces matériaux peu lithifiés influent sur leurs enveloppes de plasticité et la localisation des bandes cataclastiques à faibles profondeurs. Les trajets de contraintes sont estimés pour les phases d'enfouissement et de chargement tectonique (extension et compression) à partir de la relation entre contrainte principale et contraintes secondaires (K0), calibrée à partir de données de forage. Ces résultats sont intégrés à un modèle permettant d'estimer la nature et les caractéristiques structurales des bandes susceptibles de se former dans un contexte géologique donné. Un modèle structural, mécanique et pétrophysique a été établir à partir de ces différents résultats. Ce modèle est calibré à partir des données de perméabilité mesurées sur les bandes de Provence et des résultats du modèle mécanique de localisation cité précédemment. Ce modèle a ensuite été confronté à une synthèse des données de perméabilité disponibles dans la littérature et confirme l'influence des différents paramètres de contrôle pris en compte dans le modèle. Ce modèle a enfin pu être appliqué sur deux sites d'explorations/exploitations d'uranium en réservoir gréseux poreux et validé par les résultats obtenus, en concordance avec les observations de terrain.
https://tel.archives-ouvertes.fr/tel-01001389

NNT : 2013MON20067
tel-01001389
https://tel.archives-ouvertes.fr/tel-01001389
https://tel.archives-ouvertes.fr/tel-01001389/document
https://tel.archives-ouvertes.fr/tel-01001389/file/36072_BALLAS_2013_archivage-1_cor.pdf

Résumé : L'objectif de cette thèse est de s'intéresser à la chimie des substances naturelles (extraction et caractérisation des molécules issues des forêts de Guyane) et d'étudier des extraits ou familles de molécules naturelles ayant des propriétés inhibitrices de la corrosion du zinc. Dans la première partie du document, un screening de plantes a été effectué. Celles dont les extraits ont présenté les propriétés inhibitrices les plus intéressantes - la Mansoa alliaceae et la Bagassa guianensis -ont été sélectionnées parmi les Il plantes étudiées. Dans la seconde partie du document, différentes techniques électrochimiques ont été utilisées- la spectroscopie d'impédance électrochimique (SEI) et la polarisationlinéaire (PL)- afin de calculer les taux d'inhibition et de remonter aux mécanismes réactionnels caractérisant l'inhibition. Ainsi, le rôle des paramètres tels que le mode d'extraction et le milieu corrosif (ASTM et NaCI3%) sur le taux d'inhibition ont été étudiés. Ces travaux ont débouché sur de nombreux résultats expérimentaux nouveaux et notamment un modèle dynamique prenant en compte l'efficacité de l'inhibiteur en fonction de sa concentration dans le milieu
The objective of this thesis is to focus on the chemistry of na tura! substances (extraction and characterization of molecules from forests of French Guiana) and to study extracts or families ofnatural molecules with inhibiting properties of zinc corrosion. In the first part of the document, a screening of plants was made. Those whose extracts have shown the most interesting potential inhibitors - the Mansoa alliaceae and Bagassa guianensis - were selected among the Il plants studied. In the second part of the paper, different electrochemical techniques were used - the electrochemical impedance spectroscopy (EIS) and linear polarization (LP) - to calculate the inhibition rate and to understand the reaction mechanisms characterizing the inhibition. Thus, the role of parameters such as the method of extraction and the corrosive medium (ASTM and NaCI3%) on the inhibition rate were studied. This work bas led to many new experimental results including a dynamic mode! taking into account the effectiveness of the inhibitor according to its concentration in the medium

http://www.theses.fr/2014AGUY0745/document

Éditeur(s) : HAL CCSD Oxford University Press (OUP): Policy F
Résumé : International audience
We discuss a property of distance-based measures that has not been addressed with regard to evaluating the geographic concentration of economic activities. The article focuses on the choice between a probability density function of point-pair distances or a cumulative function. We begin by introducing a new cumulative function, M, for evaluating the relative geographic concentration and the co-location of industries in a non-homogeneous spatial framework. Secondly, some rigorous comparisons are made with the leading probability density function of Duranton and Overman (2005), Kd. The merits of the simultaneous use of Kd and M is proved, underlining the complementary nature of the results they provide.
Journal of Economic Geography

hal-01094082
https://hal-agroparistech.archives-ouvertes.fr/hal-01094082
DOI : 10.1093/jeg/lbp056

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Multiple chemicals are emitted in residential accommodation. Aggregate Daily Doses (ADD) (ng/kg-bw/d) were estimated for 32 semivolatile organic compounds (SVOCs) of different chemical families that are frequently detected in French dwellings in both air and settled dust. Daily doses were determined using steady-state models for the population, categorized into 11 age groups covering birth to age 30. Three routes of exposure were taken into account: dust ingestion, inhalation (gaseous and particulate phases) and dermal contact with the gaseous phase of air. Contamination levels were preferentially retrieved from large, nationwide representative datasets. A two-dimensional probabilistic approach was used to assess parametric uncertainty and identify the most influential factors. For children aged 2 to 3 years, ADD estimates spanned orders of magnitude, with median values ranging from 8.7 pg/kg-bw/d for 2,2′,3,4,4′-pentabromodiphenylether (BDE 85) to 1.3 μg/kg-bw/d for di-isobutyl phthalate (DiBP). Inhalation, ingestion and dermal pathway contributed at varying levels, and depending on compound, air was the dominant medium for 28 of the 32 compounds (either by inhalation or dermal contact). Indoor exposure estimate variance was mainly driven by indoor contamination variability, and secondarily by uncertainty in physical and chemical parameters. These findings lend support to the call for cumulative risk assessment of indoor SVOCs.
ISSN: 0160-4120

hal-01635777
https://hal.archives-ouvertes.fr/hal-01635777
https://hal.archives-ouvertes.fr/hal-01635777/document
https://hal.archives-ouvertes.fr/hal-01635777/file/Article_Expo_Pelletier_Manuscript%20Env%20Int%20rev2.pdf
DOI : 10.1016/j.envint.2017.08.024