Global Challenge Bellier, Irène
Civilisations,
09/2009
58-1
Journal Article
Recenzirano
Odprti dostop
Le titre choisi par Jean-Loup Amselle pour son Enquête sur les postcolonialismes témoigne d’une angoisse. On pourrait penser que dans un monde globalisé, interconnecté, et du point de vue d’un ...anthropologue spécialiste des « branchements » culturels, l’Occident se retrouve plutôt « interpellé » par les voix alternatives qui ont émergé dans les années 1980, si l’on se place dans la perspective du dialogue, « rattrapé » si l’on réfléchit en termes géopolitiques, ou « dépassé » si l’on pense à l...
Modelling habitat of species necessitates robust identification of relevant environmental variables linked to species distribution. To achieve this, we connect hierarchical patch theory and habitat ...modelling at multiple scales. We suggest discriminating between 'circumstancial variables' and 'process variables' on the basis of temporal evolution of the spatial links between species distribution and their environment at different scales. 'Process variables' are informative of the ecological processes driving the distribution of organisms at multiple scales. By opposition, 'circumstantial variable' provide little insight because their relationship with animal spatial distribution is subject to great variations through time. As a real case study, we investigate the relationships between auk distribution (mainly Uria aalge) and oceanographic landscapes over two scales (i.e. large ∼ 200 km and medium ∼ 50 km) during the wintering season in the Bay of Biscay. Surface salinity, mixed layer depth and chlorophyll a are identified as 'process variables' as they are invariably correlated with the spatial distribution of auks, whereas bottom temperature can be viewed as a 'circumstantial variable' since the correlation is non-constant through time at large scale. The process variables at large scale are used to model the potential habitat of auks in the Bay of Biscay during the wintering season. At medium scale, only the chlorophyll a is identified as 'process variable' and used to model preferential habitat of wintering auks in the Bay of Biscay. The analytical approach proposed here (i.e. multivariate factorial kriging in a temporal context) is an effective framework to model the potential and preferential habitat of a species and can be related to the ecological niche concept and by focusing explicitly on scale dependence, the distinction between the variables that can be used as niche descriptors into species distribution models. Then our method lead to the identification of variables that should be used to define the Grinnellian niche which is defined by environmental conditions on broad scales and the Eltonian niche which focuses on biotic interactions and resource—consumer dynamics that can be measured principally at local scales.
The Andean foreland of western Argentina (28°S-33°S) corresponds to retroarc deformations associated with the ongoing flat subduction of the Nazca plate beneath the South American lithosphere. This ...region is characterized by high levels of seismic activity and crustal active faulting. To improve earthquake source identification and characterization in the San Juan region, data from seismology, structural geology and quantitative geomorphology were integrated and combined to provide a seismotectonic model. In this seismotectonic model, the Andean back-arc of western Argentina can be regarded as an obliquely converging foreland where Plio-Quaternary deformations are partitioned between strike-slip and thrust motions that are localized on the E-verging, thin-skinned Argentine Precordillera, and the W-verging thick-skinned Sierras Pampeanas, respectively. In this seismotectonic model, the Sierra Pie de Palo appears to be a key structure playing a major role in the partitioning of the Plio-Quaternary deformations.
In eastern Indonesia, the Central Sulawesi fault system consists of complex left‐lateral strike‐slip fault zones located within the triple junction area between the Pacific, Indo‐Australian and ...Eurasian plates. Seismicity in Central Sulawesi documents low‐magnitude shallow earthquakes related, from NW to SE, to the NNW‐trending Palu‐Koro (PKF) and WNW‐trending Matano fault zones. Study of the active fault traces indicates a northward growing complexity in the PKF segmentation. Left‐lateral displacement of 370 ± 10 m of streams incised within fans, whose deposition has been dated at 11 000 ± 2300 years, yields a calculated PKF horizontal slip rate of 35 ± 8 mm yr−1. This geologically determined long‐term slip rate agrees with the far‐field strike‐slip rate of 32–45 mm yr−1 previously proposed from GPS measurements and confirms that the PKF is a fast slipping fault with a relatively low level of seismicity.
A ce jour, six millions de français sont atteints de troubles de l'audition. Face à ce problème de santé publique, des outils performants d'exploration de la fonction auditive sont indispensables. La ...Speech ABR (Speech Auditory Brainstem Response ou Réponse du tronc cérébral auditif à la parole) est un outil prometteur, comme marqueur électrophysiologique fin de l'encodage neuronal de la parole. Cependant, sa méthodologie reste peu développée, son origine neuronale incertaine et elle n'a jamais été enregistrée chez le malentendant porteur d'aides auditives. Le premier axe de cette thèse porte sur les générateurs neuronaux de la Speech ABR. Le développement d'une méthodologie de recueil topographique de cette réponse jusqu'alors décrite comme strictement sous-corticale, a d'abord suggéré la possibilité d'un générateur cortical. Une étude en stéréo-électroencéphalographie a ensuite confirmé l'existence d'une activité Speech ABR dans les cortex auditifs primaires bilatéraux. Ce résultat apporte un éclairage nouveau sur la représentation des sons de parole par système nerveux auditif. Le second axe concerne l'étude de la Speech ABR chez le malentendant appareillé. Après avoir développé une méthodologie de stimulation acoustique directement au travers des aides auditives, nous avons étudié la plasticité neuronale induite par le port d'aides auditives. Les résultats montrent une amélioration de l'identification des phonèmes amplifiés, liée à une représentation corticale modifiée et à un encodage fréquentiel rééquilibré. Ces toutes premières preuves de plasticité neuronales dès les 4 premiers mois d'utilisation des aides auditives ouvrent de nouveaux espoirs thérapeutiques
To date, six million French are hearing impaired. To address this public health issue, efficient tools for exploration of the hearing function are essentials. Speech ABR (Speech Auditory Brainstem Response) is a promising tool, being a fine electrophysiological marker of the neuronal encoding of speech. Though, its methodology remains underdeveloped, its neural origin is still uncertain, and it has never been recorded in hearing aid users. The first axis of this thesis focuses on the neural generators of Speech ABR. The development of a methodology for recording topographies of this response, up to now described as strictly subcortical, first suggested the possibility of a cortical generator. A stereo-electroencephalography study then confirmed the existence of Speech ABR activity in bilateral primary auditory cortices. This result sheds a new light on the representation of speech sounds within the auditory nervous system. The second axis concerns the study of Speech ABR in hearing aid users. After having developed a methodology of acoustic stimulation directly through hearing aids, we investigated neural plasticity induced by hearing aid use. Results show an improvement in the identification of amplified phonemes, linked to an altered cortical representation and a rebalanced frequency encoding. This very first evidence of neural plasticity as soon as the first four months of hearing aid use opens up new therapeutic hopes
A lung retransplant has been shown to be a valid option in selected patients with chronic lung allograft dysfunction (CLAD). However, a subgroup of patients may require, in addition to invasive ...mechanical ventilation, extracorporeal membrane oxygenation (ECMO) as a bridge to a retransplant. Overall and CLAD-free survival after ECMO-bridged retransplants are compared to first transplants with and without bridging ECMO and to retransplants without bridging ECMO.
We reported a retrospective, single-institution experience based on a prospective data set of all patients undergoing lung transplants between January 2004 and December 2016 with a mean follow-up of 51 ± 41 months.
A total of 230 patients (96 men, 134 women, mean age 47.3 years) had lung transplants: 200 had first transplants without bridging ECMO; 13 had first transplants with bridging ECMO; 11 had retransplants without bridging ECMO; and 6 had retransplants with bridging ECMO. The 3- and 5-year survival rates were 81%/76%, 68%/68%, 69%/46% and 50%/25%, respectively. There was no significant difference in overall survival between those who had first transplants with and without bridging ECMO or retransplants without bridging ECMO. In contrast, patients undergoing ECMO-bridged retransplants had a significantly lower overall survival rate than those with a first transplant without bridging ECMO (P = 0.007). In addition, the post-transplant CLAD-free survival curves varied significantly among the 4 treatment groups (P = 0.041), paralleling overall survival.
Patients requiring ECMO as a bridge to a retransplant had lower overall and CLAD-free survival rates compared to those who had a first transplant with and without bridging ECMO and a retransplant without bridging ECMO.
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•Obovacoumaric acid and obovatol were isolated from the methanolic extracts of Manilkara obovata.•A new ethylcanophyllate was obtained by esterification of canophyllic acid.•The ...structures were elucidated by NMR and single crystal X-ray crystallography.•Antibacterial effects of the methanolic extracts of Manilkara obovata.
The investigation of the methanolic extracts of the roots, stem bark and leaves of Manilkara obovata (Sabine & G. Don) J. H. Hemsl. (Sapotaceae), synonym Manilkara argentea Pierre ex Dubard, has led to the isolation and characterization of a new 4-phenylcoumarin derivative, in form of a racemic mixture of obovacoumaric acid (1a) and the previously reported callophyllic acid (1b) as well as a new taraxerane type triterpene named obovatol (2), alongside twenty-five known compounds. In addition, ethylcanophyllate (3a), obtained by esterification of canophyllic acid (3) is reported here for the first time. The structures of compounds were determined by comprehensive spectroscopic analyses of their 1D and 2D NMR, EI/ESI-MS and single crystal X-ray diffraction (SC-XRD) analysis for 1a and 1b, accompanied by comparison with reported records. In addition, the antibacterial activity of crude extracts, fractions and some of the isolated compounds including the hemi-synthesized ethylcanophyllate (3a) was determined against Salmonella typhi, Staphylococcus aureus ATCC4330, Enterobacter cloacae, Pseudomonas aeruginosa HM801, Streptococcus pneumoniae ATCC491619 and Escherichia coli ATCC25322 applying the broth microdilution method. While the methanolic stem bark extract showed good to significant activity against all bacterial test strains with MICs between 7.8 and 62.5 μg/mL, its fractions A and B were less active, indicating synergistic effects. This effect was also observed for the methanolic root extract, which gave a significant MIC against Staphylococcus aureus ATCC4330 with MIC < 3.9 μg/mL, but only MICs of 31.2 and 7.8 μg/mL for its fractions D and E. Likewise, though fractions F3 and F4 of the methanolic leaf extract displayed good MICs of 31.2 and 15.6 μg/mL, respectively, against Staphylococcus aureus ATCC4330, tested compounds were not stronger active. Interestingly, the hemi-synthesized ethylcanophyllate (3a) based on the completely antibacterial inactive canophyllic acid (3) displayed a good MIC of 15.6 μg/mL against Staphylococcus aureus ATCC4330, pointing here to a dominant role of the ester function in compound 3a in the structure-activity relationship.
Landscape evolution from the Early 1st millennium BCE to the mid-1st millennium CE is poorly documented around major archaeological sites in Crete. In a previous publication, the general landscape ...configuration in the vicinity of ancient Phaistos was reconstructed using a palaeoenvironmental approach, from the Proto-Palatial period (ca. 2000 BCE) to the Late-Proto Geometric period (ca. 8th cent. BCE). However, the physiography of the landscape, its hydrology and vegetation history remained uncertain for the later archaeological periods. In the present study, additional radiocarbon dates (8) together with pollen, mollusc and sedimentological analyses (CM diagram) were conducted on previously documented sediment cores. These new results enable us to reconstruct in greater detail the landscape history from the Early Archaic period to Late Byzantine times. The results indicate the continuous presence of swampland from the Proto-Geometric period (10th cent. BCE) probably until the initial stages of the Classical period (5th cent. BCE). Subsequently, during the Classical and Hellenistic periods, there was a short interval of alluvial input of terriginous sediments (not exceeding two centuries in duration) which is directly linked with the complete drying up and drainage of the swampland. We address the issue of the possible climatic origin of this abrupt hydrological change, especially in relation to regional climate change and the sedimentary history of adjacent rivers and streams. Tectonic activity in the area is also an important factor and can be invoked as a potential environmental influence. Anthropogenic factors are also considered, even though there is no direct archaeological evidence of drainage in the western Messara Plain during the Archaic and Classical periods. Finally, from Roman times to the Early Byzantine period, floodplain development prevailed in the area and ponds formed locally, in particular from the Late Hellenistic to Early Byzantine periods; this was related to the climatic conditions of the Roman Warm period. Pollen analysis reveals an open forested landscape during the time interval under investigation, within which domesticated plants such as Olea (olive) were present. However, the representation of Olea decreases continuously from the Late Geometric period to Byzantine times, probably indicating much lower intensity of land use than during Minoan times and possibly also related to the generally colder climatic conditions in Crete from the 8th cent. BCE until the 1st Cent. CE. During this latter interval, there is also the first pollen analytical evidence of Vitis sp.
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