Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Veterinary pharmaceuticals, widely used in intensive livestock production, may contaminate surface waters. Identifying their sources and pathways in watersheds is difficult because i) most veterinary pharmaceuticals are used in human medicine as well and ii) septic or sewer wastewater treatment plants (WWTP) can release pharmaceuticals into surface water, even in agricultural headwater watersheds. This study aimed to analyze the spatiotemporal variability of animal-specific, mixed-use, and human-specific pharmaceuticals, from agricultural headwaters with intensive livestock production and a WWTP to a watershed used for Water Framework Directive monitoring. Grab sampling was performed during one hydrological year upstream and downstream from a WWTP and at three dates in seven nested watersheds with areas of 1.9-84.1km2. Twenty pharmaceuticals were analyzed. Animal-specific pharmaceuticals were detected at all sampling dates upstream and downstream from the WWTP and at concentrations higher than those of human-specific pharmaceuticals. The predominance of animal-specific and mixed-use pharmaceuticals vs. human-specific pharmaceuticals observed at these sampling points was confirmed at the other sampling points. Animal-specific pharmaceuticals were detected mainly during runoff events and periods of manure spreading. A large percentage of mixed-use pharmaceuticals could come from animal sources, but it was difficult to determine. Mixed-use and human-specific pharmaceuticals predominated in the largest watersheds when runoff decreased. In areas of intensive livestock production, mitigation actions should focus on agricultural headwater watersheds to decrease the number of pathways and the transfer volume of veterinary pharmaceuticals, which can be the main contaminants
ISSN: 0048-9697

insu-01574739
https://hal-insu.archives-ouvertes.fr/insu-01574739
DOI : 10.1016/j.scitotenv.2017.07.206
PUBMED : 28783916

Éditeur(s) : HAL CCSD
Résumé : International audience
Understand the dynamics of the fresh-salt water interface in aquifers is a key issue to comprehend mixing processand to quantity the discharge of nutrients in to coastal areas. In order to go beyond the current knowledge inthis issue an experimental site has been set up at the alluvial aquifer Riera Argentona (Barcelona – Spain). Thesite comprises 16 shallow piezometers installed between 30 and 90 m from the seashore, with depths rangingbetween 15 and 25 meters. The seawater interface is being monitored using several techniques, the combinationof which will help us to understand the spatial and temporal behaviour of the mixing zone and the geochemicalprocesses occurring there. Specially the deepest piezometers are equipped with electrodes in order to performcross-hole electrical resistivity tomography (CHERT). In addition, all piezometers are also equipped with FiberOptic cable to perform distributed temperature measurements. Two single steel armoured fibre optic cable lines ofaround 600m length were installed in all boreholes. The objective is to use the cable both as passive and activetemperature sensor. The first is being done for the continuous monitoring of temperature whereas; the secondprovides a higher temperature resolution used to monitor field experiments.Periodic CHERT measurements are carried out between the piezometer equipped with electrodes, resultingin parallel and perpendicular vertical cross sections of the site resistivity. The position of the fresh-salt waterinterface can be identified due to the resistivity contrast between the saline and fresh water. Preliminary resultsof periodic distributed temperature measurements will be also be used to monitor the position of the mixing zonethanks to the contrast and seasonal temperature changes. Periodic down-hole EC profiles will be used to validatethe method.AcknowledgementsThis work was funded by the projects CGL2013-48869-C2-1 y CGL2013-48869-C2-2-R of the Spanish Government.We would like to thank SIMMAR (Serveis Integrals de Manteniment del Maresme) and the ConsellComarcal del Maresme in the construction of the research site
European Geosciences Union General Assembly 2016
Vienne, Austria

insu-01308757
https://hal-insu.archives-ouvertes.fr/insu-01308757

Éditeur(s) : American Geophysical Union
Résumé : Lagrangian analyses of a global ocean circulation model quantify the salinity changes experienced by the warm limb of the thermohaline circulation during the northward flow to the Atlantic deep convection regions. 6 Sv out of the estimated 10-Sv transfer from 45 degrees S to 47 degrees N flow through regions of prevailing surface evaporation: the southern and northern formation regions of Salinity Maximum Water and the Gulf of Cadiz/Mediterranean Sea domain. The remaining transport gains salinity through mixing with adjacent waters. As much as 6 Sv flow through the low-salinity surface mixed layer at the latitudes of the ITCZ whose effect annihilates that of the southern region of Salinity Maximum Water. Most of the salinity increase corresponds to the transformation of South to North Atlantic Central Water, with strong diapycnal transfers for the water that intersects the high and low salinity regions, and nearly isopycnal modifications for the water that avoids these regions.
Geophysical Research Letters ( GRL ) (0094-8276) (American Geophysical Union), 2006-03 , Vol. 33 , N. 6 , P. NIL_44-NIL_47

Droits : 2006 by the American Geophysical Union
http://archimer.ifremer.fr/doc/2006/publication-1213.pdf
DOI:10.1029/2005GL024938
http://archimer.ifremer.fr/doc/00000/1213/

Éditeur(s) : HAL CCSD Instituto Oswaldo Cruz, Ministério da Saúde
Résumé : International audience
Leishmania are protozoan parasites that show remarkable diversity, as revealed by the various clinical forms of leishmaniasis, which can range from mild skin lesions to severe metastatic cutaneous/mucosal lesions. The exact nature and extent of Leishmania phenotypic diversity in establishing infection is not fully understood. In order to try to understand some aspects of this diversity, we subcutaneously infected BALB/c mice with first and second generation subclones of a L. amazonensis strain isolated from a patient (BA125) and examined in vivo lesion growth rate and antimony susceptibility. In vivo fast-, medium- and slow-growing subclones were obtained; moreover, fast-growing subclones could generate slow-growing subclones and inversely, revealing the continuous generation of diversity after passage into mice. No antimony-resistant subclone appeared, probably a rare occurrence. By tagging subclone cells with a L. amazonensis genomic cosmid library, we found that only a very small number of founding cells could produce lesions. Leishmania clones transfected with in vivo selected individual cosmids were also diverse in terms of lesion growth rate, revealing the cosmid-independent intrinsic characteristics of each clone. Our results suggest that only a few of the infecting parasites are able to grow and produce lesions; later, within the cell mixture of each lesion, there coexist several parasite populations with different potentialities to grow lesions during the next infection round. This may reflect a sort of programmed heterogeneity of individual parasites, favoring the survival of some individuals in various environmental conditions.
ISSN: 0074-0276

hal-01489009
https://hal-univ-perp.archives-ouvertes.fr/hal-01489009

Éditeur(s) : HAL CCSD
Résumé : The genus Cecropia includes pioneer trees that colonize canopy gaps and cleared areas. It is widely distributed from Mexico to Northern Argentina. Cecropia trees have architecture, which corresponds to the Rauh’s architectural model. In recent studies we have found that C. obtusa/ and C. sciadophylla, in French Guiana, have a strong annual periodicity for growth, branching and flowering processes, with annual emission of 35 nodes for C. obtusa and 25 for C. sciadophylla. Those species show different life histories since C. sciadophylla has longer life expectancy. In addition, C. sciadophylla is found more frequently in forest gaps, although in French Guiana mixed populations are found. The aim of this work was to compare developmental strategies of both species in three different field stations in French Guiana and to determine how these two species coexist during its first years of life. We studied a 20-year old population of /C. sciadophylla/ at Saint Elie’s Road, a 10-year old population of /C. obtusa/ at Paracou’s field station, and a 7-year old mixed population at Counami’s Road. /C. sciadophylla /emits 25 nodes per year in both studied populations, while/ C. obtusa /emits 35 nodes in the monospecific population and 30 nodes in the mixed population. In the monocaule stage, the lower number of nodes emitted by /C. sciadophylla/ compared to /C. obtusa /is compensated with a higher internodal length, which allows finding individuals with similar ages and lengths, but different number of nodes. The branching and flowering processes start on average three years before in /C. obtusa/, however for 12-year old individuals we observed a dominancy of C. sciadophylla over C. obtusa. In the mixed population it is likely that the different life histories would decrease competition effects allowing coexistence of both species during the first stages of life
Botany 2008
Vancouver, Canada

hal-01190209
https://hal.archives-ouvertes.fr/hal-01190209
PRODINRA : 182910

Éditeur(s) : HAL CCSD American Society for Biochemistry and Molecular Biology
Résumé : International audience
Chronic low grade inflammation is closely linked to obesity-associated insulin resistance. To examine how administration of the anti-inflammatory compound indomethacin, a general cyclooxygenase inhibitor, affected obesity development and insulin sensitivity, we fed obesity-prone male C57BL/6J mice a high fat/high sucrose (HF/HS) diet or a regular diet supplemented or not with indomethacin (±INDO) for 7 weeks. Development of obesity, insulin resistance, and glucose intolerance was monitored, and the effect of indomethacin on glucose-stimulated insulin secretion (GSIS) was measured in vivo and in vitro using MIN6 β-cells. We found that supplementation with indomethacin prevented HF/HS-induced obesity and diet-induced changes in systemic insulin sensitivity. Thus, HF/HS+INDO-fed mice remained insulin-sensitive. However, mice fed HF/HS+INDO exhibited pronounced glucose intolerance. Hepatic glucose output was significantly increased. Indomethacin had no effect on adipose tissue mass, glucose tolerance, or GSIS when included in a regular diet. Indomethacin administration to obese mice did not reduce adipose tissue mass, and the compensatory increase in GSIS observed in obese mice was not affected by treatment with indomethacin. We demonstrate that indomethacin did not inhibit GSIS per se, but activation of GPR40 in the presence of indomethacin inhibited glucose-dependent insulin secretion in MIN6 cells. We conclude that constitutive high hepatic glucose output combined with impaired GSIS in response to activation of GPR40-dependent signaling in the HF/HS+INDO-fed mice contributed to the impaired glucose clearance during a glucose challenge and that the resulting lower levels of plasma insulin prevented the obesogenic action of the HF/HS diet.
ISSN: 0021-9258

hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01074835/file/JBC-2013-525220v2-Kristiansen-POSTPRINT.pdf
DOI : 10.1074/jbc.M113.525220

Éditeur(s) : Departamento de Agricultura Departamento de Agricultura ( Santo Domingo R.D )
Résumé : (Statement of Responsibility) por E.L. Ekman.
(Funding) Serie B--Botánica (Estación Agronómica de Moca) ;
Dominican Republic
Dominican Republic

07543458

Éditeur(s) : The Center ( Washington D.C )
Résumé : Relief shown by contours, and spot heights.
Depths shown by bathymetric isolines and soundings.
Mixed set: maps prepared by the Instituto Geográfico Nacional "Tommy Guardia," the Dirección de Cartográfico de Panamá, the Inter-American Geodetic Survey or the Army Map Service.
Some maps only in Spanish.
Standard map series designation: Series E762.
Includes index to adjoining sheets, boundaries and elevation guides.
(Funding) Funded in part by the University of Florida, the Florida Heritage Project of the State University Libraries of Florida, the Institute for Museum and Library Services, and the U.S. Department of Education's TICFIA granting program.
(Statement of Responsibility) prepared and published by the Defense Mapping Agency, Hydrographic/Topographic Center.
Panama
Panama

Droits : This item is a work of the U.S. federal government and not protected by copyright pursuant to 17 U.S.C. §105.
21132987
http://ufdc.ufl.edu/UF00077003/00001

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
ISSN: 0006-3207

hal-01090646
https://hal-agroparistech.archives-ouvertes.fr/hal-01090646
DOI : 10.1016/j.biocon.2010.07.034

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Ukrainian shield hosts two Palaeoproterozoic anorthosite-mangerite-charnockite-granite (AMCG) complexes (the Korosten and Korsun-Novomyrhorod complexes) that intruded Palaeoproterozoic continental crust in north-western and central parts of the shield, respectively. We report results of U-Pb zircon and baddeleyite dating of 16 samples from the Korosten plutonic complex (KPC), and 6 samples from the Korsun-Novomyrhorod plutonic complex (KNPC). Fifteen zircon samples from both complexes were also analysed for Hf isotopes. These new, together with previously published data indicate that the formation of the KPC started at c. 1815 Ma and continued until 1743 Ma with two main phases of magma emplacement at 1800–1780 and 1770–1758 Ma. Each of the main phases of magmatic activity included both basic and silicic members. The emplacement history of the KNPC is different from that of the KPC. The vast majority of the KNPC basic and silicic rocks were emplaced between c. 1757 and 1750 Ma; the youngest stages of the complex are represented by monzonites and syenites that were formed between 1748 and 1744 Ma. Both Ukrainian AMCG complexes are closely associated in space and time with mantle-derived mafic and ultramafic dykes. The Hf isotope ratios in the zircons indicate a predominantly crustal source for the initial melts with some input of juvenile Hf from mantle-derived tholeiite melts.The preferred model for the formation of the Ukrainian AMCG complexes involves the emplacement of large volumes of hot mantle-derived tholeiitic magma into the lower crust. This resulted in partial melting of mafic lower-crustal material, mixing of lower crustal and tholeiitic melts, and formation of ferromonzodioritic magmas. Further fractional crystallization of the ferromonzodioritic melts produced the spectrum of basic rocks in the AMCG complexes. Emplacement of the ferromonzodioritic and tholeiitic melts into the middle crust and their partial crystallization caused abundant melting of the ambient crust and formation of the large volumes of granitic rocks present in the complexes.
ISSN: 0301-9268

hal-01622715
https://hal.archives-ouvertes.fr/hal-01622715
DOI : 10.1016/j.precamres.2017.02.009

Éditeur(s) : Blackwell science
Résumé : This paper deals with the design of modelling tools suitable for investigating the consequences of alternative policies on the dynamics of resources and fisheries, such as the evaluation of marine protected areas (MPA). We first review the numerous models that have been developed for this purpose, and compare them from several standpoints: population modelling, exploitation modelling and management measure modelling. We then present a generic fisheries simulation model, Integration of Spatial Information for FISHeries simulation (ISIS-Fish). This spatially explicit model allows quantitative policy screening for fisheries with mixed-species harvests. It may be used to investigate the effects of combined management scenarios including a variety of policies: total allowable catch (TAC), licenses, gear restrictions, MPA, etc. Fisher's response to management may be accounted for by means of decision rules conditioned on population and exploitation parameters. An application to a simple example illustrates the relevance of this kind of tool for policy screening, particularly in the case of mixed fisheries. Finally, the reviewed models and ISIS-Fish are discussed and confronted in the light of the underlying assumptions and model objectives. In the light of this discussion, we identify desirable features for fisheries simulation models aimed at policy evaluation, and particularly MPA evaluation.
Fish and Fisheries (1467-2960) (Blackwell science), 2005-12 , Vol. 6 , N. 4 , P. 307-349

Droits : 2005 Blackwell Publishing, Inc
http://archimer.ifremer.fr/doc/2005/publication-1031.pdf
DOI:10.1111/j.1467-2979.2005.00199.x
http://archimer.ifremer.fr/doc/00000/1031/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Kazdag Massif exposes an extensional metamorphic dome in the Biga Peninsula of northwest Turkey, bounded on both flanks by detachments and/or shear zones. The northern flank is marked by the extensional Alakeci shear zone (ASZ), with poorly known P-T-t path. We therefore focus on metamorphic conditions and temporal history of the ASZ to determine its tectono-metamorphic evolution. ASZ mylonites were derived from both the footwall Kazdag Massif core metamorphic rocks and the hanging wall Cetmi melange lithologies. The mylonitic fabrics in the ASZ depict a top-to-the NNE shearing, parallel to the NNE-plunging stretching lineation and NNW-dipping mylonitic foliation. This geometry implies normal sense movement i.e. north-side down-dip extensional displacement along this flank of the Kazdag Massif. The northward transition from ductile to brittle-ductile shear regime through the ASZ shows that the non-coaxial deformation occurred at decreasing temperatures and degree of metamorphism. The paragenesis in equilibrium of the mylonitic gneisses and schists contains quartz + feldspar + muscovite + biotite + garnet staurolite, with late retrogressive chlorite after biotite and garnet. Calculated thermo-barometric conditions for ASZ rocks yielded pressures between 6.9 and 5.7 kbar and temperatures between 706 and 587 degrees C, which constrain the peak metamorphism. The mylonitic rocks supplied isochron Ar-39/Ar-40 mica ages between 26.97 and 24.19 Ma, which we interpret to date the cooling of the mylonites following the P-T decrease across the ASZ. The metamorphic data support the structural record and strengthen the extensional character of the ASZ. The transition from sillimanite-bearing footwall Kazdag Massif core gneisses in the deeper structural levels to chlorite schists; towards the shallow structural levels at the top of the ASZ, is consistent with an extensional exhumation of the metamorphic pile. These data allow us to determine the peak P-T conditions and the temporal evolution in the northern flank of the Kazdag Massif, where Late Oligocene extensional exhumation was assisted by NNE-directed ductile-brittle ASZ, which had operated from amphibolite to greenschist facies. The ASZ, together with similar time-constrained ductile-brittle activity of SW-directed detachment along the southern flank of the massif, collectively indicates a bivergent mode of extension in the western Kazdag Massif. The latter is likely influenced by magmatic activity spatially and temporally related to these extensional zones. At the regional scale, the bivergent tectono-metamorphic pattern of the Kazdag Massif is similar to those observed on other places of the north-central Aegean domain.
ISSN: 0024-4937

hal-00445246
https://hal.archives-ouvertes.fr/hal-00445246
DOI : 10.1016/j.lithos.2009.02.010

Éditeur(s) : Gauthier-Villars
Résumé : The variability of ''yellow substance'' in waters of the Skagerrak and the Kattegat was studied during the international Skagex programme in 1990 and 1991. Data on attenuation of light and fluorescence of dissolved organic matter (DOM) in sea water were collected with a spectral transmissiometer and a submersible fluorometer within a depth range of 0-250 m at several stations. More than fifty-fold variations of fluorescence intensity over space and time were due to the combined action of different sources of DOM in the straits. The surface maximum of fluorescing DOM, related to river outflow, was spreading from Oslo fjord to the central Skagerrak in late spring. This maximum may be ecologically important because it diminishes shortwave PAR. In the autumn the brightest DOM fluorescence was found in the Kattegat and along the Norwegian coast in accordance with earlier studies. The local minima of DOM fluorescence are associated with the Jutland current. Both the instability of the current and a ten-fold difference in DOM content between deep layers of the Skagerrak and Kattegat resulted in strong synoptic variability of fluorescence in the transitional area between the straits. Seasonal and synoptic variabilities of ''yellow substance'' were minimal in the southern Kattegat. The vertical gradients of DOM fluorescence were mostly negative at the depth of the thermocline of the open Skagerrak in spring, reaching values of 40-50 % m-1. Fine structure and complex shape were inherent to fluorescence profiles from areas of intensive water mixing. DOM fluorescence closely covaried with attenuation of UV light: the correlation coefficient was + 0.9 for wavelength w <= 350 nm regardless of season. The inverse dependence between wavelength derivative and magnitude of UV attenuation in the straits did not change with season. DOM fluorescence and water salinity were negatively correlated at depths of 25-50 m but they varied independently in the upper 10 m. No significant correlation between fluorescence and nitrates has been found. Estimates of correlation with phosphates ranged from 0.7 to 0.8. In general, the changes of fluorescence were due to variations of DOM content in sea water but not to variability of DOM composition or state. The properties of DOM fluorescence in the Skagerrak-Kattegat area make it a useful natural tracer of water movements suitable for active remote sensing with airborne lidar.
Oceanologica Acta (0399-1784) (Gauthier-Villars), 1993 , Vol. 16 , N. 2 , P. 115-125

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00099/21041/18667.pdf
http://archimer.ifremer.fr/doc/00099/21041/

Éditeur(s) : New York, NY : Carl Fischer, Inc. ; 1929. New York, NY : Carl Fischer, Inc. ; 1929.
Résumé : Four-part chorus for mixed voices.

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The Roussillon sedimentary Basin (South France) is a complex multi-layered aquifer, close to the Mediterranean Sea facing seasonally increases of water abstraction and salinization issues. We report geochemical and isotopic vertical variability in this aquifer using groundwater sampled with a Westbay System® at two coastal monitoring sites: Barcarès and Canet. The Westbay sampling allows pointing out and explaining the variation of water quality along vertical profiles, both in productive layers and in the less permeable ones where most of the chemical processes are susceptible to take place.The aquifer layers are not equally impacted by salinization, with electrical conductivity ranging from 460 to 43,000 μS·cm− 1. The δ2H–δ18O signatures show mixing between seawater and freshwater components with long water residence time as evidenced by the lack of contribution from modern water using 3H, 14C and CFCs/SF6. S(SO4) isotopes also evidence seawater contribution but some signatures can be related to oxidation of pyrite and/or organically bounded S. In the upper layers 87Sr/86Sr ratios are close to that of seawater and then increase with depth, reflecting water–rock interaction with argillaceous formations while punctual low values reflect interaction with carbonate. Boron isotopes highlight secondary processes such as adsorption/desorption onto clays in addition to mixings. At the Barcarès site (120 m deep), the high salinity in some layers appear to be related neither to present day seawater intrusion, nor to Salses-Leucate lagoonwater intrusion. Groundwater chemical composition thus highlights binary mixing between fresh groundwater and inherited salty water together with cation exchange processes, water–rock interactions and, locally, sedimentary organic matter mineralisation probably enhanced by pyrite oxidation.Finally, combining the results of this study and those of Caballero and Ladouche (2015), we discuss the possible future evolution of this aquifer system under global change, as well as the potential management strategies needed to preserve quantitatively and qualitatively this water resource.
ISSN: 0048-9697

hal-01685219
https://hal-brgm.archives-ouvertes.fr/hal-01685219
DOI : 10.1016/j.scitotenv.2016.05.016

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
The ENE-WSW Autun Shear Zone in the northeastern part of the French Massif Central has been interpreted previously as a dextral wrench fault. New field observations and microstructural analyses document a NE-SW stretching lineation that indicates normal dextral motions along this shear zone. Further east, similar structures are observed along the La Serre Shear Zone. In both areas, a strain gradient from leucogranites with a weak preferred orientation to highly sheared mylonites supports a continuous Autun-La Serre fault system. Microstructural observations, and shape and lattice-preferred orientation document high-temperature deformation and magmatic fabrics in the Autun and La Serre granites, whereas low- to intermediate-temperature fabrics characterize the mylonitic granite. Electron microprobe monazite geochronology of the Autun and La Serre granites yields a ca. 320 Ma age for pluton emplacement, while mica 40Ar-39Ar datings of the Autun granite yield plateau ages from 305 to 300 Ma. The ca. 300 Ma 40Ar-39Ar ages, obtained on micas from Autun and La Serre mylonites, indicate the time of the mylonitization. The ca. 15-Ma time gap between pluton emplacement and deformation along the Autun-La Serre fault system argue against a synkinematic pluton emplacement during late orogenic to postorogenic extension of the Variscan Belt. A ductile to brittle continuum of deformation is observed along the shear zone, with Lower Permian brittle faults controlling the development of sedimentary basins. These results suggest a two-stage Late Carboniferous extension in the northeastern French Massif Central, with regional crustal melting and emplacement of the Autun and La Serre leucogranites around 320 Ma, followed, at 305-295 Ma, by ductile shearing, normal brittle faulting, and subsequent exhumation along the Autun-La Serre transtensional fault system.
ISSN: 1437-3254

insu-00596918
https://hal-insu.archives-ouvertes.fr/insu-00596918
https://hal-insu.archives-ouvertes.fr/insu-00596918/document
https://hal-insu.archives-ouvertes.fr/insu-00596918/file/Article_Morvan_v_INIST.pdf
DOI : 10.1007/s00531-011-0673-z

Éditeur(s) : HAL CCSD American Association of Petroleum Geologists
Résumé : International audience
We describe the structure, microstructure, and petrophysical properties of fault rocks from two normal fault zones formed in low-porosity turbiditic arkosic sandstones, in deep diagenesis conditions similar to those of deeply buried reservoirs. These fault rocks are characterized by a foliated fabric and quartz-calcite sealed veins, which formation resulted from the combination of the (1) pressure solution of quartz, (2) intense fracturing sealed by quartz and calcite cements, and (3) neoformation of synkinematic white micas derived from the alteration of feldspars and chlorite. Fluid inclusion microthermometry in quartz and calcite cements demonstrates fault activity at temperatures of 195degC to 268degC. Permeability measurements on plugs oriented parallel with the principal axes of the finite strain ellipsoid show that the Y axis (parallel with the foliation and veins) is the direction of highest permeability in the foliated sandstone (10-2 md for Y against 10-3 md for X, Z, and the protolith, measured at a confining pressure of 20 bars). Microstructural observations document the localization of the preferential fluid path between the phyllosilicate particles forming the foliation. Hence, the direction of highest permeability in these fault rocks would be parallel with the fault and subhorizontal, that is, perpendicular to the slickenlines representing the local slip direction on the fault surface. We suggest that a similar relationship between kinematic markers and fault rock permeability anisotropy may be found in other fault zone types (reverse or strike-slip) affecting feldspar-rich lithologies in deep diagenesis conditions.
ISSN: 0149-1423

hal-00903428
https://hal.archives-ouvertes.fr/hal-00903428
DOI : 10.1306/03071312127

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
Genetic recombination occurs during meiosis, the key developmental programme of gametogenesis. Recombination in mammals has been recently linked to the activity of a histone H3 methyltransferase, PR domain containing 9 (PRDM9), the product of the only known speciation-associated gene in mammals. PRDM9 is thought to determine the preferred recombination sites--recombination hotspots--through sequence-specific binding of its highly polymorphic multi-Zn-finger domain. Nevertheless, Prdm9 knockout mice are proficient at initiating recombination. Here we map and analyse the genome-wide distribution of recombination initiation sites in Prdm9 knockout mice and in two mouse strains with different Prdm9 alleles and their F(1) hybrid. We show that PRDM9 determines the positions of practically all hotspots in the mouse genome, with the exception of the pseudo-autosomal region (PAR)--the only area of the genome that undergoes recombination in 100% of cells. Surprisingly, hotspots are still observed in Prdm9 knockout mice, and as in wild type, these hotspots are found at H3 lysine 4 (H3K4) trimethylation marks. However, in the absence of PRDM9, most recombination is initiated at promoters and at other sites of PRDM9-independent H3K4 trimethylation. Such sites are rarely targeted in wild-type mice, indicating an unexpected role of the PRDM9 protein in sequestering the recombination machinery away from gene-promoter regions and other functional genomic elements.
ISSN: 0028-0836

hal-00877666
https://hal.archives-ouvertes.fr/hal-00877666
DOI : 10.1038/nature11089
PUBMED : 22660327

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
In cyclic females, FSH stimulates ovarian estradiol (E2) production and follicular growth up to the terminal stage. A transient elevation in circulating FSH and E2 levels occurs shortly after birth. But what could be the action of FSH on the ovary during this period, and in particular how it stimulates ovarian steroidogenesis without supporting terminal follicular maturation is intriguing. By experimentally manipulating FSH levels, we demonstrate in mice that the mid-infantile elevation in FSH is mandatory for E2 production by the immature ovary, but that it does not stimulate follicle growth. Importantly, FSH increases aromatase expression to stimulate E2 synthesis, however it becomes unable to induce cyclin D2, a major driver of granulosa cell proliferation. Besides, although FSH prematurely induces luteinizing hormone (LH) receptor expression in granulosa cells, LH pathway is not functional in these cells to induce their terminal differentiation. In line with these results, supplying infantile mice with a superovulation regimen exacerbates E2 production, but it does not stimulate the growth of follicles and it does not induce ovulation. Overall, our findings unveil a regulation whereby high postnatal FSH concentrations ensure the supply of E2 required for programming adult reproductive function without inducing follicular maturation before puberty.
ISSN: 2045-2322

hal-01516023
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01516023
DOI : 10.1038/srep46222
PUBMED : 28397811
PUBMEDCENTRAL : PMC5387682

Éditeur(s) : HAL CCSD Nature Publishing Group
Résumé : International audience
EXOSC10 is a catalytic subunit of the exosome that processes biologically active transcripts, degrades aberrant mRNAs and targets certain long non-coding RNAs (lncRNAs). The yeast orthologue Rrp6 is required for efficient growth and gametogenesis, and becomes unstable during meiosis. However, nothing is known about the localization, stability and function of EXOSC10 in the rodent male germline. We detect the protein in nucleoli and the cytoplasm of mitotic and meiotic germ cells, and find that it transiently associates with the XY body, a structure targeted by meiotic sex chromosome inactivation (MSCI). Finally, EXOSC10 becomes unstable at later stages of gamete development. To determine Exosc10's meiotic function, we inactivated the gene specifically in male germ cells using cre recombinase controlled by Stra8 or Ddx4/Vasa promoters. Mutant mice have small testes, show impaired germ cell differentiation and are subfertile. Our results demonstrate that EXOSC10 is post-translationally regulated in germ cells, associate the protein with epigenetic chromosome silencing, and reveal its essential role in germ cell growth and development.
ISSN: 2045-2322

hal-01647082
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647082
DOI : 10.1038/s41598-017-14643-y
PUBMED : 29118343