361 research outputs found
Karsts, Paysages et Préhistoire
Collection edytem n°13Les Gorges de lâArdĂšche. Quelle pouvait ĂȘtre lâimpression dâun Homme parcourant celles-ci il y a plus de 30 000ans ? Quel regard portait-il sur ces versants abrupts, ces roches calcaires aux formes spectaculaires et ses nombreuxporches et autres abris sous roche ? Quelle conscience avait-il de leurs prolongements souterrains, dans la pĂ©nombredâabord, dans lâobscuritĂ© des grottes ensuite ? Force est de relever que ces diffĂ©rentes interrogations nâont pas derĂ©ponse car quels que soient les modes dâinvestigation, il nâest guĂšre possible de reconstituer ce qui est au plus profondde nous, les pensĂ©es, et ce dâautant moins si elles sont contemporaines dâune pĂ©riode sans Ă©crit, comme câest lecas de la PrĂ©histoire. Cette absence de rĂ©ponse ne signifie pas quâil ne faille pas se pencher sur ces questions, bienau contraire, et sur la place des paysages, des monuments naturels, de lieux particuliers comme les grottes dans leschoix des Hommes de la PrĂ©histoire pour les explorer, les amĂ©nager, les utiliser comme supports de reprĂ©sentationset de transmission des savoirs. Ne pouvant rĂ©pondre directement Ă ces interrogations, il est nĂ©cessaire de dĂ©finir desmodes de recherche permettant de bĂątir des hypothĂšses les plus robustes possibles pour apprĂ©hender au mieux lesreprĂ©sentations et les actions des Hommes de la PrĂ©histoire. La robustesse de ces hypothĂšses repose, Ă la fois, sur lesdonnĂ©es produites par les diffĂ©rents champs de recherche souhaitant sâinvestir sur ces questions et sur la multiplicitĂ©des travaux sur diffĂ©rents terrains et aires culturelles. Cet ouvrage sâinscrit dans cette dĂ©marche en croisant diffĂ©rentsregards sur les paysages et patrimoines du Sud-ArdĂšche
Aspergillus fumigatus stimulates the NLRP3 inflammasome through a pathway requiring ROS production and the Syk tyrosine kinase
Invasive aspergillosis (IA) is a life-threatening disease that occurs in immunodepressed patients when infected with Aspergillus fumigatus. This fungus is the second most-common causative agent of fungal disease after Candida albicans. Nevertheless, much remains to be learned about the mechanisms by which A. fulmigatus activates the innate immune system. We investigated the inflammatory response to conidia and hyphae of A. fumigatus and specifically, their capacity to trigger activation of an inflammasome. Our results show that in contrast to conidia, hyphal fragments induce NLRP3 inflammasome assembly, caspase-1 activation and IL-1ÎČ release from a human monocyte cell line. The ability of Aspergillus hyphae to activate the NLRP3 inflammasome in the monocytes requires K+ efflux and ROS production. In addition, our data show that NLRP3 inflammasome activation as well as pro-IL-1ÎČ expression relies on the Syk tyrosine kinase, which is downstream from the pathogen recognition receptor Dectin-1, reinforcing the importance of Dectin-1 in the innate immune response against fungal infection. Furthermore, we show that treatment of monocytes with corticosteroids inhibits transcription of the gene encoding IL-1ÎČ. Thus, our data demonstrate that the innate immune response against A. fumigatus infection involves a two step activation process, with a first signal promoting expression and synthesis of pro-IL-1ÎČ; and a second signal, involving Syk-induced activation of the NLRP3 inflammasome and caspase-1, allowing processing and secretion of the mature cytokine
Salivary biomarkers for the diagnosis and monitoring of neurological diseases
Current research efforts on neurological diseases are focused on identifying novel disease biomarkers to aid in diagnosis, provide accurate prognostic information and monitor disease progression. With advances in detection and quantification methods in genomics, proteomics and metabolomics, saliva has emerged as a good source of samples for detection of disease biomarkers. Obtaining a sample of saliva offers multiple advantages over the currently tested biological fluids as it is a non-invasive, painless and simple procedure that does not require expert training or harbour undesirable side effects for the patients. Here, we review the existing literature on salivary biomarkers and examine their validity in diagnosing and monitoring neurodegenerative and neuropsychiatric disorders such as autism and Alzheimer\u27s, Parkinson\u27s and Huntington\u27s disease. Based on the available research, amyloid beta peptide, tau protein, lactoferrin, alpha-synuclein, DJ-1 protein, chromogranin A, huntingtin protein, DNA methylation disruptions, and micro-RNA profiles display a reliable degree of consistency and validity as disease biomarkers
Immunotherapies for Neurodegenerative Diseases
The current treatments for neurodegenerative diseases are mostly symptomatic without affecting the underlying cause of disease. Emerging evidence supports a potential role for immunotherapy in the management of disease progression. Numerous reports raise the exciting prospect that either the immune system or its derivative components could be harnessed to fight the misfolded and aggregated proteins that accumulate in several neurodegenerative diseases. Passive and active vaccinations using monoclonal antibodies and specific antigens that induce adaptive immune responses are currently under evaluation for their potential use in the development of immunotherapies. In this review, we aim to shed light on prominent immunotherapeutic strategies being developed to fight neuroinflammation-induced neurodegeneration, with a focus on innovative immunotherapies such as vaccination therapy
Find the food first: An omnivorous sensory morphotype predates biomechanical specialization for plant based diets in phyllostomid bats
Aerobic oxidation of 1,6-hexanediol to adipic acid over Au-based catalysts: the role of basic supports
1,6-Hexanediol is a relevant building blocks that could be obtained from biomass and transformed under base free conditions into adipic acid used for polymer synthesis
Gurzil
DivinitĂ© chez les Laguatan* de Tripolitaine dâaprĂšs Corippe (Johan., V, 22-26). Au moment dâengager le combat, les Laguatan lĂąchaient sur lâennemi un taureau reprĂ©sentant leur dieu Gurzil. Ce dieu Ă©tait nĂ© de lâaccouplement du dieu Amon*, sans doute celui de Siwa*, et dâune vache. Cette divinitĂ© jouissait dâun culte organisĂ© qui semble avoir dĂ©passĂ© celui qui Ă©tait rendu aux dieux locaux africains ou aux simples gĂ©nies*. Corippe mentionne, en effet, chez les Laguatan, la prĂ©sence dâidoles en ..
Modeling Edar expression reveals the hidden dynamics of tooth signaling center patterning.
When patterns are set during embryogenesis, it is expected that they are straightly established rather than subsequently modified. The patterning of the three mouse molars is, however, far from straight, likely as a result of mouse evolutionary history. The first-formed tooth signaling centers, called MS and R2, disappear before driving tooth formation and are thought to be vestiges of the premolars found in mouse ancestors. Moreover, the mature signaling center of the first molar (M1) is formed from the fusion of two signaling centers (R2 and early M1). Here, we report that broad activation of Edar expression precedes its spatial restriction to tooth signaling centers. This reveals a hidden two-step patterning process for tooth signaling centers, which was modeled with a single activator-inhibitor pair subject to reaction-diffusion (RD). The study of Edar expression also unveiled successive phases of signaling center formation, erasing, recovering, and fusion. Our model, in which R2 signaling center is not intrinsically defective but erased by the broad activation preceding M1 signaling center formation, predicted the surprising rescue of R2 in Edar mutant mice, where activation is reduced. The importance of this R2-M1 interaction was confirmed by ex vivo cultures showing that R2 is capable of forming a tooth. Finally, by introducing chemotaxis as a secondary process to RD, we recapitulated in silico different conditions in which R2 and M1 centers fuse or not. In conclusion, pattern formation in the mouse molar field relies on basic mechanisms whose dynamics produce embryonic patterns that are plastic objects rather than fixed end points
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