Éditeur(s) : HAL CCSD Universidad Complutense de Madrid
Résumé : Based on new seismological and recent faulting data, we analyze five main sectors in the western part of the Betic Cordillera from an active tectonic perspective: i. The northwestern frontal sector of the cordillera, including the Morón de la Frontera area, with shallow (< 15 km depth) seismogenic active NE-SW reverse and strike-slip faults that do not reach the surface. ii. The Teba area, in the External Zones, which is deformed by sparse N-S to NW-SE normal faults with associated wedges of Quaternary sediments and active strike-slip faults at intermediate crustal levels. iii. The Ronda Basin, representing the major Late Miocene intramontane basin of the western Betic Cordillera, is mainly deformed by NNE-SSW and WNW-ESE folds and locally by NW-SE normal faults. iv. The internal part of the orogen, which is characterized by shallow (<40 km) and intermediate (40 to 120 km depth) seismicity beneath Málaga and the Alborán Sea, ENE-WSW folding, relief uplift, river incision and scarce active faults with surface expression. v. The Spanish Atlantic coast, which coincides with the western end of the Betic orogen, where Pliocene to Quaternary shallowmarine sedimentary rocks are deformed by meso-scale NW-SE oriented normal faults and few ENE-WSW reverse faults. These data support the recent tectonic activity of the western Betic Cordillera determined by the NW-SE Eurasian-African convergence with variable features from the mountain front, characterized by shallow deformations, up to the Internal Zones that mainly undergo uplift and intermediate seismicity.
ISSN: 1698-6180

hal-00750359
https://hal.archives-ouvertes.fr/hal-00750359
DOI : 10.5209/rev_JIGE.2012.v38.n1.39211

Éditeur(s) : HAL CCSD Springer/Terra Scientific Publishing Company
Résumé : International audience
We carried out a detailed paleomagnetic, rock-magnetic, and Thellier paleointensity study of all similar to 3.6 My Pliocene lava flow succession in southern Georgia. An earlier study (Camps et al., 1996) revealed that several consecutive lava flows record an intermediate polarity direction at the base of the section followed by a thick reverse polarity zone. The transitional field was interpreted as an excursion within chron 2Ar or all upper Cochiti-Gilbert reversal. New paleomagnetic data reported here have been obtained from nearby lava successions. In total, about 170 standard paleomagnetic cores belonging to 22 lava flows were collected during the 2005 sample collection campaign. Rock-magnetic experiments showed that the remanence is carried by Ti-poor titanomagnetite in most of the samples. The fraction of grains with multidomain magnetic structure does not seem to be important. Characteristic remanent magnetization was successfully determined oil all samples. The direct correlation with the original (Thoki) sequence, previous preliminary measurements of natural remanent magnetization (Sologashvili, 1986), and field observations allowed us to establish a new magnetic stratigraphy. The lower part of section is characterized by intermediate magnetic polarity followed by thick reversely magnetized lavas. The upper sequence, represented by 18 consecutive flows yielded normal magnetic polarity. The mean paleointensity of the intermediate field is drastically reduced with respect to the post-transitional field strength. Based on all available radiometric ages and new paleomagnetic data, it may be speculated that Gilbert-Gauss (R-N) reversal was recorded at the upper part of sequence. Lower intermediate polarity flows possibly represent a form of precursor of this reversal that is similar to the Matuyama-Brunhes geomagnetic transition.
ISSN: 1343-8832

hal-00413099
https://hal.archives-ouvertes.fr/hal-00413099

Éditeur(s) : Yale University
Résumé : Data from a hydrographic section carried out in January-March 1994 offshore from the eastern coast of South America from 50S to 10N, are used to quantify the full-depth exchanges of water between the western boundary currents and the ocean interior. In the upper and intermediate layers, the westward transport associated with the southern branch of the South Equatorial Current was 49 Sv at the time of the cruise. The transports of the central and northern branches in the upper 200 m were 17 Sv and 12 Sv, respectively. After subtraction of the parts that recirculate in the subtropical, subequatorial, and equatorial domains, the fraction of the South Equatorial Current that effectively contributes to the warm water export to the North Atlantic is estimated at 18 Sv. The poleward boundary of the current southern branch is at 31S through the whole thickness of the subtropical gyre, but the latitude of the northern boundary varies from 7 degrees 30'S at the surface to 27S at 1400 m depth. The estimated latitude of its bifurcation into the Brazil Current and North Brazil Undercurrent also varies downward from about 14S at the surface to 28S at a depth of 600 m.In the North Atlantic Deep Water, eastward flows exceeding 10 Sv are observed at 3 degrees -4 degrees of latitude in both hemispheres, at 10S, and at 34S-30S. Between 4S and 17S, a net westward flow with an estimated transport of 19 Sv reinforces the southward deep western boundary current. Cyclonic circulations of Antarctic Bottom Water along the western boundaries of the Argentine and Brazil basins have amplitudes of 15 Sv and 13 Sv, respectively, exceeding those of the interbasin exchanges. The net alongshore transport of this water mass between the hydrographic section and the continental slope reverses to a southward direction from 13S to 27S, probably in relation with an eastward shift of the equatorward near-bottom boundary current at these latitudes.
Journal of Marine Research (0022-2402) (Yale University), 2000-11 , Vol. 58 , N. 6 , P. 1007-1039

Droits : 2000 Yale University
http://archimer.ifremer.fr/doc/2000/publication-803.pdf
DOI:10.1357/002224000763485782
http://archimer.ifremer.fr/doc/00000/803/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
We report paleomagnetic results from four overlapping stratigraphic sections (55 flows) through the lava pile in Tjörnes peninsula (North Iceland). The initial aim of our study was to check the existence of intermediate directions previously interpreted as belonging to the Matuyama-Brunhes geomagnetic reversal (MBR), and complete this record with Thellier-Thellier paleointensity determinations and 40Ar/39Ar radioisotopic dating. The directional results corroborate the findings by Kristjánsson et al. (1988): a sequence of reversed, transitional, normal, and transitional polarity (R-T-N-T) is found in each section. The polarity change is characterized by a jump from reversed virtual geomagnetic poles (VGPs) to a quasi-cluster of transitional VGPs located over China, followed by a second jump to a cluster of normal polarity before moving again towards intermediate polarities. Reversely magnetized flows exhibit a magnetic mineralogy well suited for paleointensity determination. Of these 25 flows, 20 yielded paleointensity estimates of good quality. Unfortunately, the systematic presence of coarse multidomain (MD) titanomagnetite in the transitional and normal polarity flows hampered paleointensity estimates for these flows. The Virtual Dipole Moments (VDM) calculated for the reversed polarity flows vary from 4.9 to 7.0 × 1022 Am2 with an arithmetic mean value of 5.5 ± 0.8 × 1022 Am2. This value is identical to the mean VDM obtained for the 0.3-5 Ma time window and thus strengthens the conclusion that the recent geomagnetic field strength is anomalously high compared to that older than 0.3 Ma. 40Ar/39Ar isochron ages were obtained with the incremental heating technique on groundmass separates or phenocryst-poor whole rock samples. Six of the transitionally magnetized lavas yielded isochron ages that are indistinguishable from one another at the 95% confidence level. The weighted average age is 862 ± 51 ka. In the upper part of this volcanic sequence, the normally magnetized flows yielded a weighted average age of 787 ± 40 ka. This finding supports the conclusion that a geomagnetic excursion within the Matuyama chron is recorded in the lower part of the Tjörnes volcanic sequence, whereas only the latest portion of the MBR is recorded by flows in the upper part of the lava pile. This conclusion is supported via comparison of the VGPs obtained from the lavas with those predicted by a geomagnetic field model.
ISSN: 0012-821X

hal-00618515
https://hal.archives-ouvertes.fr/hal-00618515
https://hal.archives-ouvertes.fr/hal-00618515/document
https://hal.archives-ouvertes.fr/hal-00618515/file/Camps-epsl2011.pdf
DOI : 10.1016/j.epsl.2011.07.026

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Absolute earthquake hypocenter locations have been determined in the area offshore eastern Taiwan, at the Southernmost Ryukyu subduction zone. Location process is run within a 3D velocity model by combining the Taiwanese and neighboring Japanese networks and using the 3D MAXI technique. The study focuses on the most active seismic cluster in the Taiwan region that occurs in the forearc domain offshore eastern Taiwan. Earthquakes distribute mainly along 2 active planes. The first one aligns along the subduction interface and the second one, shallower affects the overriding margin. Focal mechanisms within the shallow group indicate that nodal planes are either compatible with high-angle back-thrusts or low-angle thrusts. The active seismic deformation exclusively indicates reverse faulting revealing that the forearc basement undergoes trench-perpendicular strong compression. By integrating the seismological image into the regional context, we favor the hypothesis in which the dense seismicity occurring offshore marks the activity of en-échelon high-angle reverse faults accommodating the uplift of a broken piece of Ryukyu Arc basement, called Hoping Basement Rise. The uplift is inferred to be caused by the subduction of an oceanic relief, either exotic block, seamount or oceanic crust sliver. Our favored solution satisfies the narrowness of epicenter's cluster along the Hoping Canyon, and the observation of high-angle active faults on seismic lines crossing the area. Furthermore, this solution is compatible with the active uplift of the Hoping Rise demonstrated from morphological and sedimentological data. We do not exclude the branching of the high-angle reverse faults system onto a splay fault connected with the subduction interface but further investigations are needed to map precisely the 3D distribution of active faults that break the margin.
ISSN: 0040-1951

hal-00407726
https://hal.archives-ouvertes.fr/hal-00407726
DOI : 10.1016/j.tecto.2007.11.018

Éditeur(s) : HAL CCSD Elsevier
Résumé : Remerciements :- Dr. Jacques Delabie- Andrea Yockey-Dejean- Geoff Brown- Jean-Pierre Andrieu
Background: Most ant venoms consist predominantly of small linear peptides, although some contain disulfide linked peptides as minor components. However, in striking contrast to other ant species, some Anochetus venoms are composed primarily of disulfide-rich peptides. In this study, we investigated the venom of the ant Anochetus emarginatus with the aim of exploring these novel disulfide-rich peptides.Methods: The venom peptidome was initially investigated using a combination of reversed-phase HPLC and mass spectrometry, then the amino acid sequences of the major peptides were determined using a combination of Edman degradation and de novo MS/MS sequencing. We focused on one of these peptides, U-1-PONTX-Ae1a (Ae1a), because of its novel sequence, which we predicted would form a novel 3D fold. Ae1a was chemically synthesized using Fmoc chemistry and its 3D structure was elucidated using NMR spectroscopy. The peptide was then tested for insecticidal activity and its effect on a range of human ion channels.Results: Seven peptides named poneritoxins (PONTXs) were isolated and sequenced. The three-dimensional structure of synthetic Ae1a revealed a novel, compact scaffold in which a C-terminal beta-hairpin is connected to the N-terminal region via two disulfide bonds. Synthetic Ae1a reversibly paralyzed blowflies and inhibited human L-type voltage-gated calcium channels (Ca(v)1).Conclusions: Poneritoxins from Anochetus emarginatus venom are a novel class of toxins that are structurally unique among animal venoms.General significance: This study demonstrates that Anochetus ant venoms are a rich source of novel ion channel modulating peptides, some of which might be useful leads for the development of biopesticides.
ISSN: 0304-4165

hal-01511987
https://hal.archives-ouvertes.fr/hal-01511987
https://hal.archives-ouvertes.fr/hal-01511987/document
https://hal.archives-ouvertes.fr/hal-01511987/file/2016_Touchard_Biochimica_Biophysica_%7B4B3BE6A3-AE83-4C6E-B678-BBFB5CC84AF7%7D.pdf
DOI : 10.1016/j.bbagen.2016.07.027

Éditeur(s) : Actes de colloques Ifremer, Tahiti, French Polynesia, 20 Feb - 4 Mar 1989, n°9, chap. 52, pp.543-557
Résumé : The Polynesian grouper, Epinephelus microdon , was chosen as an experimental model in order to investigate about factors controlling sexuality in groupers.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/1989/acte-1439.pdf
http://archimer.ifremer.fr/doc/00000/1439/

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
Benthic microbial fuel cells (BMFCs) are continuous electricity generators using electroactive microorganisms and organic matter from aquatic environment, respectively, as catalysts and substrate. In this paper, first a low-cost PVC-made structure is constructed to harvest electricity from mangrove environment located in French Guiana. An in situ BMFC has given power density of 30 mW/m2 of the anodic surface area. This performance has been confirmed by experience in laboratory where inter-electrode distance and electrode surface area appeared to be power increasing factors. However, the output power of one BMFC is not used to supply real devices such as autonomous sensors. Second, to meet this expectation, in parallel and in series associations were considered. These associations were made in order to increase the output voltage and consequently the power, to reach levels that can supply small sensors (about 3 V). Finally, to improve the performance of the series association and to avoid the voltage reversal phenomenon, a voltage balancing circuit was simulated and added to the series connections. With balancing method, the cell voltage of BMFCs can be equalized, and the performances can be improved. This allows an optimal energy harvesting and a better global efficiency of the set.
ISSN: 0363-907X

hal-01683128
https://hal.univ-antilles.fr/hal-01683128
DOI : 10.1002/er.3270

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Despite the increasing dominance of turf algae in coral reefs, few studies have investigated their physiological and ecological responses to changes in abiotic factors. We tested the effects of depth and ultraviolet radiation on turf algae at different levels of successional stages using two experiments. Depth-related differences were found for all turf algal communities, characterized by a higher amount of the cyanobacteria taxon Dichothrix and the red filamentous genera Poly-/Herposiphonia in the shallow and the appearance of oscillating cyanobacteria in deeper waters. In the first experiment, cross-depth transplantation of 153 days old communities influenced percentage cover, biomass and taxa composition. Downward transplantation lowered overall biomass and abundance of the foraminifera Sorites, whereas the crustose green alga Pringsheimiella and filamentous cyanobacteria colonized the communities. A nearly reverse pattern was observed in upward transplanted communities. Overall we distinguished between sensitive taxa, like Oscillatoria, and taxa able to acclimate to alterations in their environment, like Pringsheimiella, Poly/Herposiphonia and Dichothrix. In the second experiment, algae grown for 285 days at 5 m were exposed together with a set of sterile settlement tiles to three UVR regimes at 2 m for 22 days. UVR had no effect on turf algal communities regardless of successional stage. This study highlights the presence of high light and UV tolerant species. The high UV tolerance of turf communities may confer a competitive advantage over other more sensitive coral reef biota, such as corals. This study demonstrates that turf algae are dynamic communities exhibiting species-specific resistance to environmental changes.
ISSN: 0022-0981

hal-01333486
https://hal-univ-perp.archives-ouvertes.fr/hal-01333486
DOI : 10.1016/j.jembe.2014.07.017

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) : Amer Geophysical Union
Résumé : After the January 12, 2010, Haiti earthquake, we deployed a mainly offshore temporary network of seismologic stations around the damaged area. The distribution of the recorded aftershocks, together with morphotectonic observations and mainshock analysis, allow us to constrain a complex fault pattern in the area. Almost all of the aftershocks have a N-S compressive mechanism, and not the expected left-lateral strike-slip mechanism. A first-order slip model of the mainshock shows a N264 degrees E north-dipping plane, with a major left-lateral component and a strong reverse component. As the aftershock distribution is sub-parallel and close to the Enriquillo fault, we assume that although the cause of the catastrophe was not a rupture along the Enriquillo fault, this fault had an important role as a mechanical boundary. The azimuth of the focal planes of the aftershocks are parallel to the north-dipping faults of the Transhaitian Belt, which suggests a triggering of failure on these discontinuities. In the western part, the aftershock distribution reflects the triggering of slip on similar faults, and/or, alternatively, of the south-dipping faults, such the Trois-Baies submarine fault. These observations are in agreement with a model of an oblique collision of an indenter of the oceanic crust of the Southern Peninsula and the sedimentary wedge of the Transhaitian Belt: the rupture occurred on a wrench fault at the rheologic boundary on top of the under-thrusting rigid oceanic block, whereas the aftershocks were the result of the relaxation on the hanging wall along pre-existing discontinuities in the frontal part of the Transhaitian Belt. Citation: Mercier de Lepinay, B., et al. (2011), The 2010 Haiti earthquake: A complex fault pattern constrained by seismologic and tectonic observations, Geophys. Res. Lett., 38, L22305, doi:10.1029/2011GL049799.
Geophysical Research Letters (0094-8276) (Amer Geophysical Union), 2011-11 , Vol. 38 , N. L22305 , P. 7 p.

Droits : 2011 by the American Geophysical Union
http://archimer.ifremer.fr/doc/00054/16557/14071.pdf
DOI:10.1029/2011GL049799
http://archimer.ifremer.fr/doc/00054/16557/

Éditeur(s) : HAL CCSD Thieme Publishing
Résumé : International audience
The aim of the present study was to compare the effects of prior cycling and a successive run on respiratory muscle performance during a cycle-run succession as performed in the triathlon. We hypothesized that despite the moderate intensity of exercise and the absence of exhaustion, the crouched cycling position would induce a decrease in respiratory muscle performance that would be reversed by the successive vertical run position. Ten male triathletes (22.6 +/- 1.1 yr) performed a four-trial protocol: (1) an incremental cycle test to assess maximal oxygen uptake (VO2max), (2) 20 min of cycling (C), (3) 20 min of running (R), and (4) 20 min of cycling followed by 20 min of running (C-R). Trials 2, 3 and 4 were performed at the same metabolic intensity, i. e., 75 % of VO2max. Respiratory muscle force was assessed by measuring maximal expiratory (P(Emax)) and inspiratory (P(Imax)) pressures from the functional residual capacity (FRC) before and 10 min after C, R, and C-R. Respiratory muscle endurance was assessed one day before and 30 min after C, R, and C-R, by measuring the time limit (T(lim)), which corresponds to the length of time a respiratory load can be sustained before the process of fatigue develops sufficiently to cause task failure. The results showed a similar significant decrease in P(Imax) (132.4 +/- 4.9 versus 125.7 +/- 5.6 cm H2O, p < 0.05) and T(lim) (5.22 +/- 0.28 versus 3.68 +/- 0.32 min, p < 0.05) post-C and post-C-R (133.7 +/- 4.0 versus 126.9 +/- 5.2 cm H2O, and 5.29 +/- 0.18 versus 3.49 +/- 0.41 min, respectively, p < 0.05) compared with the pre-trial values. In contrast, P(Imax) and T(lim) were not significantly decreased post-R (131.8 +/- 6.1 cm H2O versus 129.6 +/- 6.4 cm H2O, and 4.90 +/- 0.69 versus 4.40 +/- 0.56 min, respectively, p > 0.05). We concluded that moderate intensity exercise not performed to exhaustion induced a decrease in respiratory muscle performance. Moreover, the respiratory muscle fatigue induced by prior cycling was maintained, and neither reversed nor worsened, by the successive run.
ISSN: 0172-4622

hal-01622938
https://hal-umontpellier.archives-ouvertes.fr/hal-01622938
DOI : 10.1055/s-2003-37201
PUBMED : 12582954

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
A detailed rock-magnetic and archeointensity study was carried out on materials baked by a western Mexican artisan following traditional techniques to produce faithful reproductions of archeological pieces of the Michoacan region (Western Mesoamerica). The field strength at the site (41.0 +/- 0.51 mu T) was measured with a fluxgate magnetometer and the temperature of the furnace during the baking process was monitored continually by means of a thermocouple placed in the middle of the baking cavity.;Rock-magnetic experiments performed on the raw material (clay and paste) and on in situ prepared baked ceramics and bricks included measurement of thermomagnetic curves (susceptibility and strong-field magnetization versus temperature), first-order reversal curves (FORC), anisotropy of magnetic susceptibility (AMS) and anisotropy of thermoremanent magnetization (A-TRM). Magnetite and probably hematite are present in the samples as carriers of the remanence. Hysteresis ratios suggest that the samples fall in the pseudo-single-domain grain size region, which may indicate a mixture of multidomain and a significant amount of single-domain grains.;Ceramic pieces and brick fragments were subjected to the Thellier-Coe archeointensity method and to an alternative paleointensity experiment, with a TRIAXE magnetometer, in order to check whether they are faithful recorders of the local geomagnetic field strength.;Mean raw-intensity of sample M1 (pottery) overestimates a 7% the expected site intensity, while those corresponding to the brick samples (LQ1 and LQ2) underestimate it 15%. Brick sample LNQ shows a slightly lower intensity (7%), but agrees with the expected site intensity within the experimental uncertainty. The intensity retrieved from the volcanic fragment also included closely reproduces the expected intensity. After A-TRM and cooling-rate corrections, all mean raw values move closer to the expected intensity.;Measurement of temperatures at different parts inside the kiln (bottom and upper parts of both central and peripheral parts) revealed the existence of significant thermal gradients, similar to those observed in ovens from other localities. Different cooling rates are then expected in a single oven.;The scatter in the intensity determinations observed in this study, retrieved from pieces elaborated together in the same oven, could arise from this differentiated cooling rate within the oven and thus, to an inappropriate cooling rate correction in the archeointensity protocol. As this situation was probably reproduced in the baking of ancient ceramic artifacts, a better knowledge of the temperature distribution inside these types of kiln would be desirable in order to choose the appropriate cooling rate correction.
ISSN: 0031-9201

hal-00644559
https://hal.archives-ouvertes.fr/hal-00644559
DOI : 10.1016/j.pepi.2011.06.007

Éditeur(s) : HAL CCSD American Association for the Advancement of Science
Résumé :  
Amazon forests are a key but poorly understood component of the global carbon cycle. If, as anticipated, they dry this century, they might accelerate climate change through carbon losses and changed surface energy balances. We used records from multiple long-term monitoring plots across Amazonia to assess forest responses to the intense 2005 drought, a possible analog of future events. Affected forest lost biomass, reversing a large long-term carbon sink, with the greatest impacts observed where the dry season was unusually intense. Relative to pre-2005 conditions, forest subjected to a 100-millimeter increase in water deficit lost 5.3 megagrams of aboveground biomass of carbon per hectare. The drought had a total biomass carbon impact of 1.2 to 1.6 petagrams (1.2 × 1015 to 1.6 × 1015 grams). Amazon forests therefore appear vulnerable to increasing moisture stress, with the potential for large carbon losses to exert feedback on climate change.
ISSN: 0036-8075

hal-01032111
https://hal.archives-ouvertes.fr/hal-01032111
DOI : 10.1126/science.1164033

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Les « printemps » arabo-africains se suivent et ne se ressemblent pas, aux  « printemps » doux et pacifiques succèdent des « printemps » chauds et sanguinaires. Un « printemps » en chasse un autre, mais le bilan est mitigé, l’avenir encore incertain et les acquis réversibles. Indéniablement, ils n’ont pas encore dit leur dernier mot. De nouvelles raisons de préoccupations voient le jour, de nature différente ; elles ont pour nom : instabilité, intolérance, chaos, paralysie de l’État et ses institutions, menace qui plane sur le droit des femmes, des minorités de tous ordres, sur la liberté de conscience et le droit à la différence. Mais aussi de nouvelles raisons d’espérer des lendemains meilleurs.L'Afrique n’en est pas à un « printemps » près, mais les retombées sont toujours restées en deçà des attentes. La mise en place laborieuse d'un système panafricain des droits de l’homme et des peuples fut saluée, à juste titre, comme un évènement majeur et un « printemps » avant  la  lettre.L'article retrace toutes les étapes et péripéties de cette mise en place, le contexte, les tenants  et  les aboutissants de l'élaboration de la Charte africaine des droits de l'homme et des peuples qui en constitue le substratum. Il met en exergue ses spécificités, ses originalités, les mécanismes prévus et les organes érigés (Commission et Cour Africaine des Droits de l'Homme et des Peuples) pour assurer l'application et la promotion des  droits de l'homme et des peuples. À beaucoup d’égards, la Charte innove courageusement et originalement par  rapport à ses illustres devancières.Dans son intitulé d'abord : il s'agit d'une Charte et non d’une Déclaration. Ensuite, les droits de l’homme sont couplés aux droits des peuples et hissés au même niveau d'importance et d'impérativité, sinon plus. Enfin, la Charte ne reconnait pas seulement des droits mais elle édicte des devoirs (envers la famille, la communauté, l'État, l'Afrique, l’environnement, etc.) et fait de l'accomplissement de ceux-ci une condition de la jouissance de ceux-là. Deux décennies de recul et seulement 12 affaires traitées (sur seulement 24 qui lui sont parvenus), on peut dire que cette dernière est loin d'avoir atteint sa vitesse de croisière et mérité tant d'espoir placé en elle. De là à jeter le bébé avec l'eau du  bain, occulter tous les bienfaits d'un système qui est loin d'avoir démérité, il n'y a qu'un pas que ne franchirons guère.
The Arab-African springs follow one after the other but are not alike, soft and peaceful springs are succeeded by hot and bloodthirsty springs. One spring expels another one, but the situation s balance sheet is mixed, the future is still uncertain and the experiences are reversible. Undeniably, they didn't say their last word. New reasons of preoccupation are born, made of different nature : they are named : instability, intolerance, chaos, paralysis of the state and its institutions, threat to the women rights, minorities of all kinds, the conscience freedom and the rights to difference ; but also new reasons to hope for a better tomorrow. Africa is not at its last "spring" but the rewards remained always below expectations.The laborious Implementation of a Pan-African system of human rights and peoples was hailed, deservedly, as a major event and a "spring" far ahead of its time. The article in attached outlines all the steps and vicissitudes of this implementation rerelease the context, the end and results of the elaboration of human and people’s rights African charter which constitutes the substratum. It highlights its specificities, its originalities, the planed mechanisms and high instruments (Commission and the African Court of Human and Peoples' Rights) to ensure the application and the promotion of human and people’s rights.In many respects, the Charter innovates bravely and originally compared to its illustrious predecessors.At first in its title: it is matter of a charter and not a declaration. Then, human rights are closely connected to the people’s rights and hoisted at the same level of importance and imperativeness or more. Finally, the Charter does not only recognizes rights but it promulgates duties (to family, community, the state, Africa, the environment, etc.) and makes of the fulfillment of these a condition of enjoyment of those. Two decades backout, and only 12 cases treated (from only 24 have reached) later, in front of the Court, we can say that it is far from having reached its cruising speed and deserved so much hope placed in it.From there to throw the baby out with the bath water, hide all the benefits of a system which is far from being unworthy, there is only one step which shall exceed hardly.
Afrique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.6735
http://journals.openedition.org/etudescaribeennes/6735

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
IODP Expedition 352 cored igneous rocks from the Izu-Bonin-Mariana forearc crust. Cores from Sites U1440 and U1441 recovered Eocene basalts and related rocks and cores from Sites U1439 and U1442 recovered Eocene boninites and related rocks. We selected samples from Holes U1439C, U1440B and U1442A for palaeointensity measurements. Hysteresis measurements and high and low-temperature magnetization curves show that samples from Hole U1440B undergo magneto-chemical changes when heated and are mostly composed of single-domain (SD) or pseudo-single-domain (PSD) titanomaghemite. In contrast, the same measurements show that most selected samples from Holes U1439C and U1442A are thermally stable and are composed of either SD or PSD titanomagnetite with very little titanium content, or SD ferromagnetic grains with a large paramagnetic contribution. Thellier–Thellier palaeointensity experiments carried out on U1439C and U1442A samples give a good success rate of 25/60 and Virtual Dipole Moment (VDM) values between 1.3 and 3.5 × 1022 Am2. Multispecimen palaeointensity experiments with the domain-state corrected method carried out on 55 samples from Hole U1440B (divided into four groups) and 20 from Hole U1439C gave poor quality results, but indicated a VDM around 4–6 × 1022 Am2 in Hole U1440B forearc basalts. These results are in agreement with the few, low VDM values previously measured on Eocene rocks. However, they do not support an inverse relationship between field intensity and reversal rate for this period of time, since the Eocene reversal rate was low.
ISSN: 0956-540X

hal-01622775
https://hal.archives-ouvertes.fr/hal-01622775
https://hal.archives-ouvertes.fr/hal-01622775/document
https://hal.archives-ouvertes.fr/hal-01622775/file/carvalloGJI2017.pdf
DOI : 10.1093/gji/ggx208

Éditeur(s) : HAL CCSD
Résumé : International audience
The present study was conducted to assess the effects of Cd exposure on estrogen signaling in the zebrafish brain, as well as the potential protective role of Zn against Cd-induced toxicity. For this purpose, the effects on transcriptional activation of the estrogen receptors (ERs), aromatase B (Aro-B) protein expression and molecular expression of related genes were examined in vivo using wild-type and transgenic zebrafish embryos. For in vitro studies, an ER-negative glial cell line (U251MG) transfected with different zebrafish ER subtypes (ERα, ERβ1 and ERβ2) was also used. Embryos were exposed either to estradiol (E2), Cd, E2+Cd or E2+Cd+Zn for 72 h and cells were exposed to the same treatments for 30 h. Our results show that E2 treatment promoted the transcriptional activation of ERs and increased Aro-B expression, at both the protein and mRNA levels. Although exposure to Cd, does not affect the studied parameters when administered alone, it significantly abolished the E2-stimulated transcriptional response of the reporter gene for the three ER subtypes in U251-MG cells, and clearly inhibited the E2 induction of Aro-B in radial glial cells of zebrafish embryos. These inhibitory effects were accompanied by a significant downregulation of the expression of esr1, esr2a, esr2b and cyp19a1b genes compared to the E2-treated group used as a positive control. Zn administration during simultaneous exposure to E2 and Cd strongly stimulated zebrafish ERs transactivation and increased Aro-B protein expression, whereas mRNA levels of the three ERs as well as the cyp19a1b remained unchanged in comparison with Cd-treated embryos. In conclusion, our results clearly demonstrate that Cd acts as a potent anti-estrogen in vivo and in vitro, and that Cd-induced E2 antagonism can be reversed, at the protein level, by Zn supplement.
Journal of Applied Toxicology

Droits : info:eu-repo/semantics/OpenAccess
hal-01274217
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274217
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274217/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01274217/file/Inhibitory%20effect%20of%20Cadmium%20on%20estrogen_accepted.pdf
DOI : 10.1002/jat.3285

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
Strain and strain rate partitioning in partially molten rocks are two of the important mechanisms that govern the process of coupling and/or decoupling of the partially molten lithosphere. Consequently, the proportion of partial melt and crystals and their network in partially molten rocks influence the degree of the partitioning along with the bulk rheology of the system. This study explores the possible role of finite strain and strain rate on the rate and volume of partial melting and crystallization in a metapelitic system undergoing deformation. Cylinders of synthetic quartz-muscovite aggregate (7: 3 volume ratio) were deformed in torsion at 750 C, 300 MPa and constant shear strain rate ((gamma) over dot = 3 x 10(-4) s(-1)) for finite shear strains (gamma) 1-15. The deformed samples were studied along the longitudinal tangential ( LT) and axial ( LA) sections to obtain the data along a range of strain rates for a given finite strain and vice versa. The results showed that deformation plays an important role on the kinetics of partial melting and crystallization. With increasing strain rate, amount and rate of crystallization comprise the volumetrically dominant process compared to partial melting at a given finite strain. In contrast, when the strain rate is constant, partial melting is the dominant process over crystallization up to moderate strain (gamma < 5). The dominant process reverses at higher strain, and the system shows more crystallization than partial melting. Application of the experimental data to geological systems implies that for metapelites a significant amount (similar to 20%) of partial melt can generate at high strain rate and moderate strain (gamma similar to 7), but at high strain (gamma = 15) the system is melt depleted. Under such conditions, decoupling should take place in brittle-ductile mode. On the other hand, rocks undergoing deformation with low strain rates and strain (gamma < 3) contain more than 25% partial melt, which can act as a major decoupling agent by localizing ductile shear zones.
ISSN: 0148-0227

hal-00617714
https://hal.archives-ouvertes.fr/hal-00617714
DOI : 10.1029/2010JB007865

Éditeur(s) : HAL CCSD Geological Society of America
Résumé : International audience
We present a regional model of plate geometry and kinematics of Southeast Asia since the Late Cretaceous, embedded in a global plate model. The model involves subduction polarity reversals and sheds new light on the origin of the subduction polarity reversal currently observed in Taiwan. We show that this subduction zone reversal is inherited from subduction of the proto–South China Sea plate and owes its current location to triple junction migration and slab rollback. This analysis sheds new light on the plate tectonic context of the Taiwan orogeny and questions the hypothesis that northern Taiwan can be considered an older, more mature equivalent of southern Taiwan.
ISSN: 0091-7613

hal-01397683
https://hal.archives-ouvertes.fr/hal-01397683
DOI : 10.1130/G37821.1

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : Vertical displacements on the SW-NE T (e) over capt fault (Eastern Pyrenees Axial Zone, France), which separates the Variscan Canigou-Caranca and Mont-Louis massifs, were constrained using a thermochronologic multi-method approach. Ar-40/Ar-39 data from the granitic Mont-Louis massif record its Variscan cooling history and reveal no ages younger than Early Cretaceous, while the Canigou-Caranca gneiss massif records systematically younger Ar-40/Ar-39 ages. These younger Ar-40/Ar-39 ages in the Canigou-Caranca gneiss massif are the result of partial to total rejuvenation of argon isotopic systems related to a thermal flow coeval with the Cretaceous HT-BP metamorphism in the North Pyrenean Zone. Only the deepest rocks from the Canigou-Caranca suffered this extensive Mid-Cretaceous thermal overprint probably due to differential burial around 4 km at that time. The post Mid-Cretaceous vertical displacements along the T (e) over capt fault are recorded by "low" temperature thermochronology using K-feldspar Ar-40/Ar-39, zircon and apatite fission track and (U-Th)/He datings. The Mont-Louis granite samples experienced a long period of protracted cooling reflecting a lack of thermo-tectonic activity in this area from Late Palaeozoic to Early Cenozoic, followed by cooling from 55-60 Ma to Late Eocene at a mean rate of 15-20 degrees C/Ma in the final stage. This cooling stage corresponds to T (e) over capt fault reactivation with a reversed component, promoting exhumation of the Mont-Louis roof zone contemporaneously with the south-vergent Pyrenean thrusting. In the Canigou-Caranca massif, the main cooling event occurred from 32 to 18 Ma at a maximum rate of 30 degrees C/Ma during Early Oligocene followed by a more moderate rate of 3 degrees C/Ma from Late Oligocene to Early Burdigalian, coeval with the normal reactivation of the T (e) over capt fault in brittle conditions that accommodated the final exhumation of the massif during the opening of the Gulf of Lion.
ISSN: 1437-3254

hal-00411442
https://hal.archives-ouvertes.fr/hal-00411442
DOI : 10.1007/s00531-007-0179-x