77 research outputs found

    A Cretaceous carbonate delta drift in the Montagna della Maiella, Italy

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    The Upper Cretaceous (Campanian\u2013Maastrichtian) bioclastic wedge of the Orfento Formation in the Montagna della Maiella, Italy, is compared to newly discovered contourite drifts in the Maldives. Like the drift deposits in the Maldives, the Orfento Formation fills a channel and builds a Miocene delta-shaped and mounded sedimentary body in the basin that is similar in size to the approximately 350 km 2 large coarse-grained bioclastic Miocene delta drifts in the Maldives. The composition of the bioclastic wedge of the Orfento Formation is also exclusively bioclastic debris sourced from the shallow-water areas and reworked clasts of the Orfento Formation itself. In the near mud-free succession, age-diagnostic fossils are sparse. The depositional textures vary from wackestone to float-rudstone and breccia/conglomerates, but rocks with grainstone and rudstone textures are the most common facies. In the channel, lensoid convex-upward breccias, cross-cutting channelized beds and thick grainstone lobes with abundant scours indicate alternating erosion and deposition from a high-energy current. In the basin, the mounded sedimentary body contains lobes with a divergent progradational geometry. The lobes are built by decametre thick composite megabeds consisting of sigmoidal clinoforms that typically have a channelized topset, a grainy foreset and a fine-grained bottomset with abundant irregular angular clasts. Up to 30 m thick channels filled with intraformational breccias and coarse grainstones pinch out downslope between the megabeds. In the distal portion of the wedge, stacked grainstone beds with foresets and reworked intraclasts document continuous sediment reworking and migration. The bioclastic wedge of the Orfento Formation has been variously interpreted as a succession of sea-level controlled slope deposits, a shoaling shoreface complex, or a carbonate tidal delta. Current-controlled delta drifts in the Maldives, however, offer a new interpretation because of their similarity in architecture and composition. These similarities include: (i) a feeder channel opening into the basin; (ii) an excavation moat at the exit of the channel; (iii) an overall mounded geometry with an apex that is in shallower water depth than the source channel; (iv) progradation of stacked lobes; (v) channels that pinch out in a basinward direction; and (vi) smaller channelized intervals that are arranged in a radial pattern. As a result, the Upper Cretaceous (Campanian\u2013Maastrichtian) bioclastic wedge of the Orfento Formation in the Montagna della Maiella, Italy, is here interpreted as a carbonate delta drift

    "Megalosaurus cf. superbus" from southeastern Romania: the oldest known Cretaceous carcharodontosaurid (Dinosauria: Theropoda) and its implications for earliest Cretaceous Europe-Gondwana connections

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    La mise en scĂšne du "Jeu d'Adam"

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    Il y a peu de temps encore, la mise en scĂšne du Jeu d'Adam posait peu de problĂšmes aux historiens du thĂ©Ăątre religieux, malgrĂ© le laconisme de rubriques qui, pour ĂȘtre nombreuses, ne disaient pas ce que l'on aurait aimĂ© le plus savoir. Ainsi G. Cohen pouvait-il imaginer que "sous le porche s'Ă©levait un Ă©chafaud Ă  quelques pieds de terre et des escaliers, sans doute, le reliaient Ă  la place oĂč Ă  quelques mĂštres de distance, se massait la foule avide de contempler l'enfer dont on sait mal la fo..

    Étude sur le sens moral du Mystùre de la Passion de Jean Michel

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    Accarie Maurice. Étude sur le sens moral du MystĂšre de la Passion de Jean Michel. In: Bulletin de l'Association d'Ă©tude sur l'humanisme, la rĂ©forme et la renaissance, n°8, 1978. pp. 35-39

    Studies of mechanisms involved in visceral hypersensitivity of colic origin

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    Les douleurs abdominales, principale cause de consultation en gastroentĂ©rologie, sont souvent le reflet d’un dysfonctionnement du tractus gastro‐intestinal, parfois responsable d’un Syndrome de l’Intestin Irritable (SII) ou d’une Maladie Inflammatoire Chronique de l’Intestin (MICI). Ces deux types de pathologies ont des caractĂ©ristiques bien distinctes (inflammation sĂ©vĂšre avec des phases de poussĂ©e et de rĂ©mission dans le cas des MICI, absentes dans le SII). Cependant elles ont aussi des caractĂ©ristiques communes comme le dĂ©veloppement d’une hypersensibilitĂ© colique (HSC), visible pendant les phases de rĂ©mission des MICI. Cette hypersensibilitĂ©, dont la physiopathologie est encore mal connue, entraĂźne une altĂ©ration de la qualitĂ© de vie des patients. Il paraĂźt donc nĂ©cessaire de comprendre les mĂ©canismes qui sous‐tendent son apparition, son dĂ©veloppement et son maintien, afin de dĂ©velopper des stratĂ©gies thĂ©rapeutiques adaptĂ©es. Les canaux ioniques sont des cibles intĂ©ressantes pour cela. Deux ont particuliĂšrement retenu notre attention : le canal ASIC3 (Acid Sensing Ion Channels), sensible Ă  l’acidose tissulaire et impliquĂ© dans de nombreux processus physiopathologiques douloureux et le canal calcique Cav3.2 (voltage‐gated calcium channel) impliquĂ© dans la mĂ©canoperception physiologique et physiopathologique. Dans une premiĂšre partie, nous avons Ă©valuĂ© le rĂŽle des sous‐unitĂ©s ASIC3 dans l’hypersensibilitĂ© colique. Pour cela, nous avons utilisĂ© plusieurs modĂšles animaux mimant une hypersensibilitĂ© colique de diverses origines chez des animaux dĂ©ficients pour le canal ASIC3 et leurs littermates. Le premier modĂšle utilisait du DSS Ă  deux concentrations : 0.5% et 1% induisant une hypersensibilitĂ© colique respectivement sans et avec inflammation. Le deuxiĂšme modĂšle mimait une hypersensibilitĂ© colique induite par une infection gastro‐intestinale. Pour cela, nous avons utilisĂ© une bactĂ©rie AIEC (Adherent Invasive Escerichia Coli) de souche LF82 anormalement prĂ©sente chez les patients atteints de la maladie de Crohn. Nous avons mis en Ă©vidence que le canal ASIC3 est impliquĂ© dans la mise en place de l’HypersensibilitĂ© ViscĂ©rale d’origine Colique (HSVC) dans ces deux modĂšles, et que la dĂ©lĂ©tion de cette sous‐unitĂ© entraĂźne une moindre inflammation colique. Dans un dernier modĂšle, pour dĂ©terminer si ces rĂ©sultats au niveau colique Ă©taient transposables au cas d’une hypersensibiltĂ© viscĂ©rale d’origine diffĂ©rente, nous avons choisi un modĂšle de cystite pour lequel nous n’avons pas pu mettre en Ă©vidence une implication de la sous‐unitĂ© ASIC3. Dans une deuxiĂšme partie, nous avons travaillĂ© sur le canal calcique Cav3.2, dĂ©jĂ  Ă©tudiĂ© au laboratoire, et qui n’avait pas montrĂ© d’implication dans les douleurs viscĂ©rales inflammatoires. Son implication dans l’HSC non inflammatoire a Ă©tĂ© Ă©tudiĂ©e Ă  travers deux modĂšles : le modĂšle de DSS 0.5% et le modĂšle de sĂ©paration maternelle. Une absence d’hypersensibilitĂ© chez les animaux dĂ©ficients pour ce canal a Ă©tĂ© mise en Ă©vidence, et nous avons trouvĂ© une implication de ce canal calcique chez des patients atteints du SII. La derniĂšre partie de ce travail s’est intĂ©ressĂ©e Ă  une nouvelle cible pouvant ĂȘtre impliquĂ©e dans la perception des stimuli mĂ©caniques au niveau colique, le facteur de transcription EGR‐4. Ce facteur de transcription appartient Ă  la famille des protĂ©ines en doigts de zinc et est extrĂȘmement conservĂ© entre les ĂȘtres vivants ; il est impliquĂ© dans de nombreuses cascades de signalisations cellulaires. Une Ă©quipe clermontoise a montrĂ© son implication dans la mĂ©canoperception chez la plante. Nous avons donc voulu savoir si cette implication Ă©tait transposable Ă  la souris et nos travaux se sont alors concentrĂ©s sur le cĂŽlon et sur l’implication de ce facteur lors d’une stimulation mĂ©canique. Il est principalement exprimĂ© au niveau des cellules musculaires lisses et est surexprimĂ© au niveau du cĂŽlon dans le cas d’une stimulation mĂ©canique.Abdominal pain is one of the most common gastrointestinal disorder which accounts for the majority ofconsultations in general practice and half of those in gastroenterology. They often reflect a dysfunction ofthe gastrointestinal tract may be responsible for irritable bowel syndrome (IBS) or chronic inflammatorybowel disease (IBD). Despite significant differences particularly illustrated by a severe inflammatoryphenomenon associated with IBD which is not observed in IBS, these pathologies share colonichypersensitivity (CHS) as a common feature. This hypersensitivity whose pathophysiology is still poorlyunderstood, results in impaired quality of life of patients. It therefore seems necessary to be able tounderstand the mechanisms that underlie the emergence, development and maintenance of the HSC todevelop appropriate therapeutic strategies. Ion channels are attractive targets because of their critical role insynaptic transmission of sensory information. Two of them in particular caught our attention: ASIC3 channel(Acid Sensing Ion Channels), sensitive to tissue acidosis and involved in many pathophysiological processesand painful calcium channel Cav3.2 (voltage‐gated calcium channel) involved in the physiologic andpathophysiologic mechanoperception.In the first part, we evaluated the role of ASIC3 subnits in colonic hypersensitivity. For this, we used severalanimal models mimicking colonic hypersensitivity of different origins in deficient animals for ASIC3 and theirlittermates. The first model using the DSS at two concentrations: 0.5% and 1% respectively inducing colonichypersensitivity with and without inflammation. The second model mimicking colonic hypersensitivityinduced gastrointestinal infection. For this, we used a AIEC bacteria (Adherent‐Invasive Escerichia Coli) ofLF82 strain abnormally present in patients with Crohn's disease. We were able to show that the ASIC3channel is involved in the establishment of the original Visceral Hypersensitivity Colic (HSVC) found in thesetwo models. We were also able to show that the deletion of this channel leads to lower colonic inflammationin our animals. Then, we evaluated its involvement in a cystitis model and found that this channel was notinvolved in this type of pain or in the resulting inflammation.In the second part, we worked on the calcium channel Cav3.2. This channel already studied in the laboratoryhad shown no involvement in visceral inflammatory pain, we observed his involvement in thenoninflammatory colonic hypersensitivity through two models: the DSS model 0.5% and the maternalseparation model. We were able to demonstrate a lack of hypersensitivity in animals deficient for thischannel. In addition, we found an involvement of this calcium channel in patients IBS, resulting in increasedexpression in these patients compared to control patients.The aim of this third part is to determine the EGR‐4 localization and its involvement in the mouse colonsensitivity to a mechanical stimulus. For that purpose, wild‐type and healthy mice were subjected or not to acolorectal distension (mechanical stimulus) for 10 seconds via inflation of a balloon inserted at 1cm from theanal margin. Then, we analyzed the expression of EGR‐4 at different time points after the distension at themRNA level in the colon, dorsal root ganglia (DRG) and spinal cord by quantitative RT‐PCR and its cellularlocalization in DRG, and in colon after whole‐mount dissection, by immunohistochemistry. We also identified targeted genes of this transcription factor in mouse colonic epithelial cells transfected by an EGR‐4expressing vector after microarray analysis. EGR‐4 transcription factor is localized in the colon, DRG andspinal cord cells. In addition, its expression is modified after colorectal distension in a time dependentmanner

    Étude sur le sens moral du Mystùre de la Passion de Jean Michel

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    Accarie Maurice. Étude sur le sens moral du MystĂšre de la Passion de Jean Michel. In: Bulletin de l'Association d'Ă©tude sur l'humanisme, la rĂ©forme et la renaissance, n°8, 1978. pp. 35-39

    Palygorskite and eustatism during Mid-Cretaceous in the Maiella Mountain (Abruzzi, Central Italy)

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    The clay mineralogy of Mid-Cretaceous carbonate pelagic sediments of the Maiella Mountain, a transition zone between the Abruzzi platform and the Umbrian basin, have been studied by X-ray diffraction and transmission electron microscopy. The clay assemblages are composed of chlorite, illite, smectite, illite/smectite mixed-layers and detrital palygorskite. The palygorskite occurs only in sediments deposited during anoxic periods. These periods are associated with sea-level rises, and therefore it is suggested that during Mid-Cretaceous, in the basin of the Maiella Mountain, palygorskite was derived from the reworking of pedogenic crusts or chemical sediments which were deposited on the adjacent platform areas during transgressive events.Deconinck Jean-François, Accarie H. Palygorskite and eustatism during Mid-Cretaceous in the Maiella Mountain (Abruzzi, Central Italy). In: Proceedings of the 9th international Clay Conference, Strasbourg, 1989. Vol IV : Clays in sediments. Diagenesis and hydrothermalism. Strasbourg : Institut de GĂ©ologie – UniversitĂ© Louis-Pasteur, 1990. pp. 15-22. (Sciences GĂ©ologiques. MĂ©moire, 88
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