Analyse de la tâche d'un pilote de Rafale à l'aide d'une HTA étendue à la gestion des modes dégradés

International audienceCette communication présente l'adaptation de la méthode HTA pour l'étude d'une situation dynamique incertaine et coopérative : une mission militaire aérienne réalisée par un pilote de chasse à bord d'un avion Rafale. Les boucles - perception, représentation, action - caractéristiques de la gestion d'une situation dynamique sont intégrées dans la HTA sous la forme de buts de haut-niveau. La mise en évidence de plans contingents permet de rendre compte de la gestion de l'incertitude et des situations dégradées. Enfin, la coopération multiagents est décrite par un codage des tâches de communication précisant la fonction, l'objet et les acteurs impliqués. Finalement, les intérêts et les limites de l'application de la méthode HTA dans le cadre des situations dynamiques sont discutés

Scientific Drilling

Integrated Ocean Drilling Program (IODP) Expedition 340T returned to the 1.4-km-deep Hole U1309D at Atlantis Massif to carry out borehole logging including vertical seismic profiling (VSP). Seismic, resistivity, and temperature logs were obtained throughout the geologic section in the footwall of this oceanic core complex. Reliable downhole temperature measurements throughout and the first seismic coverage of the 800–1400 meters below seafloor (mbsf) portionof the section were obtained. Distinct changes in velocity, resistivity, and magnetic susceptibility characterize the boundaries of altered, olivine-rich troctolite intervals within the otherwise dominantly gabbroic se-quence. Some narrow fault zones also are associated with downhole resistivity or velocity excursions. Small deviations in temperature were measured in borehole fluid adjacent to known faults at 750 mbsf and 1100 mbsf. This suggests that flow of seawater remains active along these zones of faulting and rock alteration. Vertical seismic profile station coverage at zero offsetnow extends the full length of the hole, including the uppermost 150 mbsf, where detachment processes are expected to have left their strongest imprint. Analysis of wallrock properties, together with alteration and structural characteristics of the cores from Site U1309, highlights the likely interplay between lithology, structure, lithospheric hydration, and core complex evolution

Innovative Policies for Alpine Towns

Knjiga Inovativne politike za alpska mesta predstavlja rezultate projekta CAPACities, v katerem smo preučevali vlogo mest v alpskem svetu. Pri tem smo se osredotočili na definicijo malih alpskih mest, njihovo vpetost v policentrični razvojni koncept, bistveni poudarek pa je bil na njihovi konkurenčnosti in privlačnosti. Teoretske podlage smo nadgradili z analizo razpoložljivih podatkov, še pomembnejše pa so bile aktivnosti v pilotnih območjih, s katerimi smo skušali ugotovitve prenašati v prakso. Predstavljene specifike pilotnih območij in tam izvedene aktivnosti so nam bile v pomoč pri izdelavi smernic in orodij za spodbujanje razvoja malih alpskih mest

Geophysical signatures of past and present hydration within a young oceanic core complex

Borehole logging at the Atlantis Massif oceanic core complex provides new information on the relationship between the physical properties and the lithospheric hydration of a slow-spread intrusive crustal section. Integrated Ocean Drilling Program Hole U1309D penetrates 1.4 km into the footwall to an exposed detachment fault on the 1.2 Ma flank of the mid-Atlantic Ridge, 30°N. Downhole variations in seismic velocity and resistivity show a strong correspondence to the degree of alteration, a recorder of past seawater circulation. Average velocity and resistivity are lower, and alteration is more pervasive above a fault around 750 m. Deeper, these properties have higher values except in heavily altered ultramafic zones that are several tens of meters thick. Present circulation inferred from temperature mimics this pattern: advective cooling persists above 750 m, but below, conductive cooling dominates except for small excursions within the ultramafic zones. These alteration-related physical property signatures are probably a characteristic of gabbroic cores at oceanic core complexes

Prevalence, risk factors, and impact on outcome of cytomegalovirus replication in serum of Cambodian HIV-infected patients (2004-2007)

BACKGROUND: In developing countries, the study of cytomegalovirus (CMV) coinfection in HIV-infected patients remains neglected. Quantitative CMV polymerase chain reaction (PCR) is the gold standard diagnostic tool for analyzing serum CMV replication and for predicting CMV disease. We estimated the prevalence of replicating CMV in sera of newly diagnosed HIV-infected Cambodian patients and examined its impact on mortality. METHODS: This cohort study was based on 2 highly active antiretroviral therapy treatment programs in Cambodia between 2004 and 2007. Quantitative CMV PCR was performed on baseline serum samples of 377 HIV-infected patients. RESULTS: The prevalence of serum CMV DNA was 55.2% (150 of 272) in patients with CD4 count <100/mm. In multivariate analysis, hemoglobin <9 g/dL, CD4 count <100/mm, and Karnofsky index <50 were independently associated with positive serum CMV DNA at baseline. During a 3-year follow-up period, CMV viral load >or=3.1 log10 copies per milliliter was significantly associated with death independently of CD4 count, other opportunistic infections, and highly active antiretroviral therapy. CONCLUSIONS: As in industrialized countries, serum CMV replication is highly prevalent among HIV-infected Cambodian patients and is associated with increased mortality. This underscores the importance of diagnostic CMV infection by PCR in sera of HIV-infected patients with CD4 count <100/mm and treating this opportunistic infection to reduce its associated mortality

PALÉORIVAGES, DUNES CÔTIÈRES ET OCCUPATIONS HUMAINES À L’EMBOUCHURE DE L’OUED TAMRI, MAROC ATLANTIQUE, AU PLÉISTOCÈNE SUPÉRIEUR (SIM 5)

A l’embouchure de l’oued Tamri, rive gauche, un paléorivage de faciès marin et fluvio-marin (unité U1) culmine aux environs de + 6m a.s.l. Une coquille marine de Patella sp. prélevée dans cette unité U1 (faciès marin) a été datée 100,02 ± 1,662 ka et 101,188 ±  1,339 ka par la méthode U/Th (SIM 5.3). La dune surincombante (série Sx) a été datée par OSL 84 ± 4 ka (SIM 5.1). A Tighrine Imksawne, à 200 m au Sud de l’embouchure, ce paléorivage est surmonté d’une séquence de dépôts dunaires et colluviaux de plus de 20 m d’épaisseur. Ces derniers renferment plusieurs paléosols rubéfiés interstratifiés et des encroûtements, témoins de périodes humides et de ruissellements, qui permettent de distinguer trois unités principales (unités U2, U3, U4) :(U2), unité d’accumulation interdunaire inférieure, où dominent les faciès détritiques continentaux de colluvionnement/ruissellement, avec de nombreux Hélicidés et de rares témoins d’outillage lithique. (U3), unité d’accumulation éolienne moyenne, à séries dunaires encroûtées, où la série (S5) a été datée par OSL 92 ± 6 ka (SIM 5.3 ou SIM 5.2), et où le paléosol rubéfié (S6) a fourni une industrie à proto-hachereaux. (U4), unité d’accumulation éolienne supérieure à séries friables, séparée de la précédente par une paléo-surface encroûtée (S6/S7) à industrie probablement épipaléolithique, et où des coquilles d’œufs d’Autruche de la série (S8) sont datées par radiocarbone à plus de 30 ka. BPLes analyses géomorphologiques, sédimentologiques et pétrographiques aboutissent à un modèle sédimentaire d’accumulation de pied de falaise morte qui permet de répondre aux contradictions apparentes entre la position de l’industrie lithique et des datations.A l’embouchure de l’oued Tamri, rive gauche, un paléorivage de faciès marin et fluvio-marin (unité U1) culmine aux environs de + 6m a.s.l. Une coquille marine de Patella sp. prélevée dans cette unité U1 (faciès marin) a été datée 100,02 ± 1,662 ka et 101,188 ±  1,339 ka par la méthode U/Th (SIM 5.3). La dune surincombante (série Sx) a été datée par OSL 84 ± 4 ka (SIM 5.1). A Tighrine Imksawne, à 200 m au Sud de l’embouchure, ce paléorivage est surmonté d’une séquence de dépôts dunaires et colluviaux de plus de 20 m d’épaisseur. Ces derniers renferment plusieurs paléosols rubéfiés interstratifiés et des encroûtements, témoins de périodes humides et de ruissellements, qui permettent de distinguer trois unités principales (unités U2, U3, U4) :(U2), unité d’accumulation interdunaire inférieure, où dominent les faciès détritiques continentaux de colluvionnement/ruissellement, avec de nombreux Hélicidés et de rares témoins d’outillage lithique. (U3), unité d’accumulation éolienne moyenne, à séries dunaires encroûtées, où la série (S5) a été datée par OSL 92 ± 6 ka (SIM 5.3 ou SIM 5.2), et où le paléosol rubéfié (S6) a fourni une industrie à proto-hachereaux. (U4), unité d’accumulation éolienne supérieure à séries friables, séparée de la précédente par une paléo-surface encroûtée (S6/S7) à industrie probablement épipaléolithique, et où des coquilles d’œufs d’Autruche de la série (S8) sont datées par radiocarbone à plus de 30 ka. BPLes analyses géomorphologiques, sédimentologiques et pétrographiques aboutissent à un modèle sédimentaire d’accumulation de pied de falaise morte qui permet de répondre aux contradictions apparentes entre la position de l’industrie lithique et des datations

Stimulation of MMP-11 (stromelysin-3) expression in mouse fibroblasts by cytokines, collagen and co-culture with human breast cancer cell lines

BACKGROUND: Matrix metalloproteinases (MMPs) are central to degradation of the extracellular matrix and basement membrane during both normal and carcinogenic tissue remodeling. MT1-MMP (MMP-14) and stromelysin-3 (MMP-11) are two members of the MMP family of proteolytic enzymes that have been specifically implicated in breast cancer progression. Expressed in stromal fibroblasts adjacent to epithelial tumour cells, the mechanism of MT1-MMP and MMP-11 induction remains unknown. METHODS: To investigate possible mechanisms of induction, we examined the effects of a number of plausible regulatory agents and treatments that may physiologically influence MMP expression during tumour progression. Thus NIH3T3 and primary mouse embryonic fibroblasts (MEFs) were: a) treated with the cytokines IL-1β, IL-2, IL-6, IL-8 and TGF-β for 3, 6, 12, 24, and 48 hours; b) grown on collagens I, IV and V; c) treated with fibronectin, con-A and matrigel; and d) co-cultured with a range of HBC (human breast cancer) cell lines of varied invasive and metastatic potential. RESULTS: Competitive quantitative RT-PCR indicated that MMP-11 expression was stimulated to a level greater than 100%, by 48 hour treatments of IL-1β, IL-2, TGF-β, fibronectin and collagen V. No other substantial changes in expression of MMP-11 or MT1-MMP in either tested fibroblast culture, under any treatment conditions, were observed. CONCLUSION: We have demonstrated significant MMP-11 stimulation in mouse fibroblasts using cytokines, matrix constituents and HBC cell lines, and also some inhibition of MT1-MMP. Our data suggest that the regulation of these genes in the complex stromal-epithelial interactions that occur in human breast carcinoma, is influenced by several mechanisms

Primitive layered gabbros from fast-spreading lower oceanic crust

Three-quarters of the oceanic crust formed at fast-spreading ridges is composed of plutonic rocks whose mineral assemblages, textures and compositions record the history of melt transport and crystallization between the mantle and the sea floor. Despite the importance of these rocks, sampling them in situ is extremely challenging owing to the overlying dykes and lavas. This means that models for understanding the formation of the lower crust are based largely on geophysical studies and ancient analogues (ophiolites) that did not form at typical mid-ocean ridges. Here we describe cored intervals of primitive, modally layered gabbroic rocks from the lower plutonic crust formed at a fast-spreading ridge, sampled by the Integrated Ocean Drilling Program at the Hess Deep rift. Centimetre-scale, modally layered rocks, some of which have a strong layering-parallel foliation, confirm a long-held belief that such rocks are a key constituent of the lower oceanic crust formed at fast-spreading ridges. Geochemical analysis of these primitive lower plutonic rocks-in combination with previous geochemical data for shallow-level plutonic rocks, sheeted dykes and lavas-provides the most completely constrained estimate of the bulk composition of fast-spreading oceanic crust so far. Simple crystallization models using this bulk crustal composition as the parental melt accurately predict the bulk composition of both the lavas and the plutonic rocks. However, the recovered plutonic rocks show early crystallization of orthopyroxene, which is not predicted by current models of melt extraction from the mantle and mid-ocean-ridge basalt differentiation. The simplest explanation of this observation is that compositionally diverse melts are extracted from the mantle and partly crystallize before mixing to produce the more homogeneous magmas that erupt

Revealing the pace of river landscape evolution during the Quaternary: recent developments in numerical dating methods

During the last twenty years, several technical developments have considerably intensified the use of numerical dating methods for the Quaternary. The study of fluvial archives has greatly benefited from these enhancements, opening new dating horizons for a range of archives at distinct time scales and thereby providing new insights into previously unanswered questions. In this contribution, we separately present the state of the art of five numerical dating methods that are frequently used in the fluvial context: radiocarbon, Luminescence, Electron Spin Resonance (ESR), 230Th/U and terrestrial cosmogenic nuclides (TCN) dating. We focus on the major recent developments for each technique that are most relevant for new dating applications in diverse fluvial environments and on explaining these for non-specialists. Therefore, essential information and precautions about sampling strategies in the field and/or laboratory procedures are provided. For each method, new and important implications for chronological reconstructions of Quaternary fluvial landscapes are discussed and, where necessary, exemplified by key case studies. A clear statement of the current technical limitations of these methods is included and forthcoming developments, which might possibly open new horizons for dating fluvial archives in the near future, are summarised