54 research outputs found

    Upper Pleistocene comparativeOSL, U/Th and 14C datings of sedimentary sequences and correlative morphodynamical implications in the South-Western Anti-Atlas (Oued Noun, 29° N, Morocco)

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    The lower Oued Noun valley, in the arid region of the Atlantic SW Anti-Atlas, contains an extensive Soltanian (= Upper Pleistocene pro-parte) terrace. The paper presents dates for these deposits and an interpretation of their fluvial dynamic and morpho-climatic geneses in this distal part of the valley.The Soltanian terrace, about 30 m thick at Fort Oued Noun, consists of 3 units: a basal deposit of coarse gravel buried by slope deposits and travertine (Unit 1); a main unit, more than 20 m thick (Unit 2) that consists of at least 7 repeated sequences each comprising basal fine gravels and sands, associated with detrital travertine, overlain by stromatolithic tufa and finally by a thick accumulation of sandy silts. These silts were deposited by suspension and decantation in shallow non-turbulent water bodies. The gravels, sands and travertines are more prominent at the bottom and in the upper parts of Unit 2 whilst silts dominate the mid members. Middle Paleolithic artefacts and bones of large mammals are found throughout this Unit.Unit 3, at the top of the formation, comprises red silts that differ from those of Unit 2, containing more aeolian grains and more palygorskyte and being spatially associated with adjacent tributaries fans.Radiometric dates were obtained on travertine (U/Th), on quartz grains extracted from sediments (OSL) and on Melanopsis and Charcoal (14C). U/Th results show three travertine constructions at ca 90, 55-50 and 25-20 ka B.P. The 90 ka dates, however, are not in correct stratigraphic position. The OSL dates suggest that the period of silt aggradation of Unit 2 occured between ca. 50 and 25 ka B.P., the main part of them being deposited between 40 and 30 ka B.P. 14C dates from the upper part of Unit 2 and the base of Unit 3, range between ca 28 and 18 ka B.P. These dates, together with geomorphological and sedimentological analyses, indicate that the valley floor had been lowered to its present depth before ca. 90 ka B.P. However, the slope deposits, older travertines and the basal gravel (Unit 1), classic fluvial and colluvial deposits, are not yet securely dated but they possibly correspond with wetter episodes in O.I.S. stages 5b, 5a and 4, or even later. The silts that form the bulk of Unit 2 were deposited into shallow swamps during biostasic episodes of O.I.S. 3 and were associated with high groundwater levels. Then, large mammals found grass and water along the valley and were hunted by Middle Paleolithic people. The water table remained high after 30 ka B.P. and the gravel-bed channels of the local tributaries were active during the 30-20 ka B.P. period. After ca. 20 ka, sediments suggest more varied conditions in this part of the valley, vegetation disappeared and soils were reworked into local colluvial fans, with concomitant aeolian deposits (Unit 3, O.I.S. 2). Finally, deep linear incision occured dissecting the Soltanian aggraded valley floor during the early Holocene.La basse vallĂ©e de l'oued Noun, aujourd'hui situĂ©e dans le domaine aride du versant sud de l'Anti-Atlas, montre une terrasse soltanienne (PlĂ©istocĂšne supĂ©rieur pro-parte) bien dĂ©veloppĂ©e. Les objectifs de cet article sont de dĂ©terminer avec prĂ©cision les Ăąges des sĂ©diments et de comprendre les changements de la dynamique fluviale, avec ses phases successives d’aggradation et d’érosion, Ă  la fin du PlĂ©istocĂšne supĂ©rieur.La formation soltanienne, Ă©paisse de 30 m Ă  Fort Oued Noun, se compose de 3 unitĂ©s : un dĂ©pĂŽt conglomĂ©ratique de base surmontĂ© par des dĂ©pĂŽts de pente et Ă  des travertins (Unité 1) ; un dĂ©pĂŽt principal de plus de 20 m (Unité 2), qui consiste en au moins 7 sĂ©quences rĂ©pĂ©titives montrant chacune Ă  la base des petits galets et des sables associĂ©s Ă  des travertins dĂ©tritiques, surmontĂ©s de travertins stromatolithiques construits finalement recouverts d'accumulations Ă©paisses de limons. Ces limons ont Ă©tĂ© dĂ©posĂ©s par suspension et dĂ©cantation dans des eaux calmes et peu profondes. Les galets, sables et travertins sont surtout frĂ©quents Ă  la base et au sommet de l’Unité 2, tandis que les limons dominent dans sa partie moyenne. Dans toute l’Unité 2, on trouve des ossements de grands mammifĂšres et des outillages lithiques du PalĂ©olithique moyen. Au sommet de la formation, des limons rouges supĂ©rieurs (Unité 3) diffĂšrent des prĂ©cĂ©dents et appartiennent Ă  des cĂŽnes dĂ©posĂ©s par les affluents locaux, avec davantage de grains Ă©oliens et de palygorskyte.Les datations radiomĂ©triques ont Ă©tĂ© obtenues  pour des travertins (U/Th), des grains de quartz extraits des sĂ©diments (OSL), des charbons et Melanopsis (14C). Les datations U/Th montrent trois pĂ©riodes de construction de travertins autour de 90, 55-50 et 25-20 ka B.P. Les rĂ©sultats Ă  90 ka ne sont toutefois pas en bon accord avec la stratigraphie. D'aprĂšs les rĂ©sultats OSL, la pĂ©riode d'aggradation des silts de l'UnitĂ© 2 se situe entre environ 50 et 25 ka B.P., la majeure partie de ces silts se dĂ©posant entre 40 et 30 ka B.P. Les datations 14C se rangent entre 28 et 18 ka B.P. Elles concernent la partie supĂ©rieure de l'Unité 2 et la partie basale de l'Unité 3.Ces rĂ©sultats, associĂ©s aux observations gĂ©omorphologiques et sĂ©dimentologiques, montrent que la vallĂ©e Ă©tait dĂ©jĂ  creusĂ©e autour de 90 ka B.P. Les dĂ©pĂŽts de pente, les plus anciens travertins et le dĂ©pĂŽt basal graveleux, ayant tous une signature de dĂ©pĂŽts colluviaux ou alluviaux classiques, ne sont pas datĂ©s avec sĂ»reté ; ils peuvent correspondre Ă  des Ă©pisodes humides des stages isotopiques 5b, 5a et 4, mais peuvent aussi ĂȘtre plus rĂ©cents. Les silts qui forment la masse de l'Unité 2 ne peuvent ĂȘtre reliĂ©s uniquement Ă  une activitĂ© fluviale et ont Ă©tĂ© dĂ©posĂ©s dans des Ă©tendues d'eaux calmes liĂ©es Ă  une Ă©lĂ©vation concomitante du niveau des nappes phrĂ©atiques durant des Ă©pisodes biostasiques du stage isotopique 3. De grands mammifĂšres ont alors pu trouver de l'eau et de l'herbe dans la vallĂ©e et ĂȘtre chassĂ©s par les hommes du PalĂ©olithique moyen. La nappe phrĂ©atique s'est maintenue Ă  un niveau Ă©levĂ© aprĂšs 30 ka B.P et les chenaux Ă  graviers des affluents locaux sont restĂ©s actifs durant la pĂ©riode 30-20 ka B.P. AprĂšs cette date, l’instabilitĂ© s’est accrue ; dans cette partie de la vallĂ©e, la vĂ©gĂ©tation s'est rarĂ©fiĂ©e, les sols ont Ă©tĂ© remaniĂ©s, Ă©difiant des cĂŽnes locaux oĂč s'observent aussi des influences Ă©oliennes (Unité 3, stage isotopique 2). Enfin, une forte incision linĂ©aire s’est produite Ă  l’HolocĂšne infĂ©rieur, dissĂ©quant l'accumulation soltanienne

    Estudio técnico de las pinturas murales de Germolles: la contribución de las técnicas de imagen

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    [EN] The ChĂąteau de Germolles is one of the rare palace in France dating from the 14th century. The noble floor is decorated with wall paintings that are a unique example of courtly love spirit that infused the princely courts of the time. After being concealed sometime in the 19th century, the paintings were rediscovered and uncovered in the middle of the 20th century and partly restored at the end of the 1990s. No scientific documentation accompanied these interventions and important questions, such as the level of authenticity of the mural decorations and the original painting technique(s) used in the medieval times remained unanswered. The combined scientific and financial supports of COSCH Cost Action and DRAC-Burgundy enabled to study Germolles’ wall paintings using some of the most innovative imaging and analytical techniques and to address some of the questions raised. The study provided significant information on the material used in the medieval times and on the conservation condition of the paintings. The data collected is vast and varied and exposed the owners of the property to the challenges of data management.[ES] El castillo de Germolles es uno de los raros palacios principescos en Francia que data del siglo XIV. La planta noble estĂĄ decorada con pinturas murales que son un ejemplo Ășnico del amor cortĂ©s, ese espĂ­ritu que se divulgĂł en las cortes de la Ă©poca.Ocultadas desde el fin del siglo XIX, las pinturas fueron descubiertas en la mitad del siglo XXy fueron parcialmente restauradas al finalde la dĂ©cada de 1990. No hay documentaciĂłn cientĂ­fica queacompañelas intervenciones, y cuestiones importantesse quedaronsin repuesta, en particular el nivel de autenticidad de las decoraciones de las paredes, asĂ­ como lastĂ©cnicaspictĂłricasutilizadasen laĂ©poca medieval. El apoyo cientĂ­fico y econĂłmico de la AcciĂłn Cost COSCH y de la DRAC de Borgoña permitiĂł elestudio delas pinturas murales de Germolles con algunas de las tĂ©cnicas de imagen y analĂ­ticasmĂĄs innovadoras, con tal de responder a algunas de las cuestiones planteadas. El estudio proporcionĂł informaciĂłnrelevante en lo que se refiere al material utilizado durante la Edad Mediay sobreel estado de conservaciĂłn de las pinturas. La toma de datos es ampliay variada, y expuso a los dueños de la propiedad al desafĂ­o de la gestiĂłn de datos.This project would not have been possible without the financial support by DRAC-Burgundy and the COST Action TD1201: Colour and Space in Cultural Heritage (COSCH) (www.cosch.info) which the authors wish to sincerely thank.Degrigny, C.; PiquĂ©, F.; Papiashvili, N.; Guery, J.; Mansouri, A.; Le GoĂŻc, G.; Detalle, V.... (2016). Technical study of Germolles’ wall paintings: the input of imaging technique. Virtual Archaeology Review. 7(15):1-8. https://doi.org/10.4995/var.2016.5831SWORD18715Giovannoni, S., Matteini, M., & Moles, A. (1990). Studies and developments concerning the problem of altered lead pigments in wall painting. Studies in Conservation, 35(1), 21-25. doi:10.1179/sic.1990.35.1.21Manuel, A., Gattet, E., De Luca, L., & Veron, P. (2013). An approach for precise 2D/3D semantic annotation of spatially-oriented images for in situ visualization applications. 2013 Digital Heritage International Congress (DigitalHeritage). doi:10.1109/digitalheritage.2013.6743752Wefers, S., Reich, T., Tietz, B. and Boochs, F. 2016. SIVT – Processing, Viewing, and Analysis of 3D Scans of the Porthole Slab and Slab B2 of ZĂŒschen I. In: S. Campana, R. Sopigno, G. Carpentiero and M. Cirillo, eds, CAA2015. Keep the Revolution Going. Proceedings of the 43rd Annual Conference on Computer Applications and Quantitative Methods In Archaeology. Oxford : Archaeopress Publishing Ltd, pp. 1067-1080

    Correlation between cytotoxicity induced by Pseudomonas aeruginosa clinical isolates from acute infections and IL-1ÎČ secretion in a model of human THP-1 monocytes

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    Type III secretion system (T3SS) in Pseudomonas aeruginosa is associated with poor clinical outcome in acute infections. T3SS allows for injection of bacterial exotoxins (e.g. ExoU or ExoS) into the host cell, causing cytotoxicity. It also activates the cytosolic NLRC4 inflammasome, activating caspase-1, inducing cytotoxicity and release of mature IL-1ÎČ, which impairs bacterial clearance. In addition, flagellum-mediated motility has been suggested to also modulate inflammasome response and IL-1ÎČ release. Yet the capacity of clinical isolates to induce IL-1ÎČ release and its relation with cytotoxicity have never been investigated. Using 20 clinical isolates from acute infections with variable T3SS expression levels and human monocytes, our aim was to correlate IL-1ÎČ release with toxin expression, flagellar motility and cytotoxicity. ExoU-producing isolates caused massive cell death but minimal release of IL-1ÎČ, while those expressing T3SS but not ExoU (i.e. expressing ExoS or no toxins) induced caspase-1 activation and IL-1ÎČ release, the level of which was correlated with cytotoxicity. Both effects were prevented by a specific caspase-1 inhibitor. Flagellar motility was not correlated with cytotoxicity or IL-1ÎČ release. No apoptosis was detected. Thus, T3SS cytotoxicity is accompanied by a modification in cytokine balance for P. aeruginosa clinical isolates that do not express Exo

    Introduction of SARS in France, March–April, 2003

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    We describe severe acute respiratory syndrome (SARS) in France. Patients meeting the World Health Organization definition of a suspected case underwent a clinical, radiologic, and biologic assessment at the closest university-affiliated infectious disease ward. Suspected cases were immediately reported to the Institut de Veille Sanitaire. Probable case-patients were isolated, their contacts quarantined at home, and were followed for 10 days after exposure. Five probable cases occurred from March through April 2003; four were confirmed as SARS coronavirus by reverse transcription–polymerase chain reaction, serologic testing, or both. The index case-patient (patient A), who had worked in the French hospital of Hanoi, Vietnam, was the most probable source of transmission for the three other confirmed cases; two had been exposed to patient A while on the Hanoi-Paris flight of March 22–23. Timely detection, isolation of probable cases, and quarantine of their contacts appear to have been effective in preventing the secondary spread of SARS in France

    COVID-19 symptoms at hospital admission vary with age and sex: results from the ISARIC prospective multinational observational study

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    Background: The ISARIC prospective multinational observational study is the largest cohort of hospitalized patients with COVID-19. We present relationships of age, sex, and nationality to presenting symptoms. Methods: International, prospective observational study of 60 109 hospitalized symptomatic patients with laboratory-confirmed COVID-19 recruited from 43 countries between 30 January and 3 August 2020. Logistic regression was performed to evaluate relationships of age and sex to published COVID-19 case definitions and the most commonly reported symptoms. Results: ‘Typical’ symptoms of fever (69%), cough (68%) and shortness of breath (66%) were the most commonly reported. 92% of patients experienced at least one of these. Prevalence of typical symptoms was greatest in 30- to 60-year-olds (respectively 80, 79, 69%; at least one 95%). They were reported less frequently in children (≀ 18 years: 69, 48, 23; 85%), older adults (≄ 70 years: 61, 62, 65; 90%), and women (66, 66, 64; 90%; vs. men 71, 70, 67; 93%, each P < 0.001). The most common atypical presentations under 60 years of age were nausea and vomiting and abdominal pain, and over 60 years was confusion. Regression models showed significant differences in symptoms with sex, age and country. Interpretation: This international collaboration has allowed us to report reliable symptom data from the largest cohort of patients admitted to hospital with COVID-19. Adults over 60 and children admitted to hospital with COVID-19 are less likely to present with typical symptoms. Nausea and vomiting are common atypical presentations under 30 years. Confusion is a frequent atypical presentation of COVID-19 in adults over 60 years. Women are less likely to experience typical symptoms than men

    Photogrammetry

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    L'apport du drone dans l'étude géomorphologique de secteurs isolés : le cas des terrasses fluviatiles du Sufrat Dishshah

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    National audienceLes Ă©tudes gĂ©omorphologiques menĂ©es dans la rĂ©gion d’Adam, au Sultanat d’Oman, sont rĂ©alisĂ©es sur un terrain exploratoire oĂč les donnĂ©es bibliographiques sont rares. Les recherches effectuĂ©es se concentrent principalement sur l’étude des terrasses fluviatiles, vestiges d’anciennes plaines alluviales aujourd’hui fossilisĂ©es. L’objectif de cette Ă©tude est de reconstituer un signal hydro-climatique Ă  l’échelle du Quaternaire rĂ©cent, pĂ©riode durant laquelle le climat a fluctuĂ© entre pĂ©riodes humides et pĂ©riodes arides dans ces rĂ©gions du globe. A terme, il s’agit de restituer une chronologie palĂ©oclimatique prĂ©cise et de mieux comprendre les conditions environnementales dans lesquelles Ă©voluaient les hommes des pĂ©riodes historiques et protohistoriques, Ă  l’origine de nombreux vestiges archĂ©ologiques dĂ©couverts dans la rĂ©gion. La production de donnĂ©es locales inĂ©dites dans ce secteur, qu’elles soient tant archĂ©ologiques, que gĂ©omorphologiques ou topographiques, est l’axe de recherche sur lequel se concentre la Mission ArchĂ©ologique Française d’Adam depuis 200

    Les pesticides dans le bassin de la Seine: Comprendre les origines et le transfert des pesticides pour en Ă©valuer l'impact sur l'homme et l'environnement

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    La contamination de l'environnement par les pesticides est une problĂ©matique majeure du XXIe siĂšcle. Les produits de synthĂšse dĂ©veloppĂ©s pour protĂ©ger les cultures sont devenus indispensables pour maintenir les rendements agricoles. Leurs usages se sont rĂ©pandus jusque dans nos villes et nos jardins pour l'entretien des allĂ©es et trottoirs. Chaque annĂ©e, de nouvelles matiĂšres actives sont autorisĂ©es. Dans le bassin versant de la Seine oĂč se mĂȘlent terres agricoles et zones pĂ©riurbaines, il est difficile d'identifier ces sources. Le constat est prĂ©occupant : les suivis de la qualitĂ© des eaux de surface montrent une contamination rĂ©currente par les pesticides sur l'ensemble du territoire. La rĂ©manence de certains produits comme l'atrazine explique Ă©galement la contamination des eaux souterraines malgrĂ© leur interdiction, ce qui a conduit Ă  l'abandon des captages d'eau potable les plus contaminĂ©s. Or, seulement 1 Ă  5 % des quantitĂ©s appliquĂ©es sont effectivement transfĂ©rĂ©es dans les cours d'eau. Dans un contexte oĂč la rĂ©glementation sur les usages et sur les seuils de contamination das l'environnement Ă©volue en continu, il devient indispensable de comprendre le devenir des pesticides dans le bassin versant. Cela passe par l'analyse du comportement des produits depuis leur application jusqu'Ă  leur transfert dans les cours d'eau ou les eaux souterraines, en tenant compte des interactions possibles dans le sol, le sous-sol et l'atmosphĂšre. Enfin, la modĂ©lisation est l'Ă©tape indispensable pour Ă©valuer le risque de contamination future par des nouveaux produits actuellement utilisĂ©s. L'Ă©tude des anciennes molĂ©cules toujours prĂ©sentes dans l'environnement permet d'Ă©tablir les paramĂštres Ă  prendre en compte. Les quantitĂ©s utilisĂ©es et le taux de dĂ©tection dans les milieux facilitent la calibration. Cela ne sera peut-ĂȘtre pas le cas des molĂ©cules plus rĂ©centes ayant un effet Ă  des doses plus infimes et devenant donc difficiles Ă  dĂ©tecter dans le milieu naturel par des techniques d'analyse chromatographique classiques. Ces analyses amĂšnent tant Ă  rechercher de nouvelles pratiques culturales qu'Ă  concevoir des programmes de rĂ©duction du recours aux produits phytosanitaires en milieu urbain, avec pour objectif une moindre contamination des milieux par les pesticides
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