75 research outputs found
Using ABM to explore the role of socio-environmental interactions on Ancient Settlement Dynamics
This paper presents a work in progress within the project « Modeling the role
of socio-environmental interactions on Ancient Settlement Dynamics - ModelAnSet
» developed by archaeologists, historians, palaeoenvironmentalists and
computer scientists at University CĂŽte dâAzur (Nice). Agent-based modelling
is used to explore the respective role of environmental and social factors in
the evolution of the settlement pattern and dynamics during the Roman period
in South-Eastern France. The model aims at simulating the impact of the
climatic and macro-economic conditions on the behaviour of Gallo-Roman
landowners. According to the profit they derive from their farms and/or villas,
which depends both on natural and socio-economic factors, the landowners
can decide to maintain without change, improve, enlarge or abandon their agricultural
holdings or to create a new one. Through the repeated landownersâ
decision-making, the ABM thus simulates a changing macro-level settlement
pattern, in terms of number, type and location of the settlements. The paper
focuses on the conceptual model in order to present the model entities and the
dynamics underlying their interactions, and explain our choices and hypotheses
Rifampicin and Its Derivative Rifampicin Quinone Reduce Microglial Inflammatory Responses and Neurodegeneration Induced In Vitro by α-Synuclein Fibrillary Aggregates
Abstract: Aggregated forms of the synaptic protein αâsynuclein (αS) have been proposed to operateas a molecular trigger for microglial inflammatory processes and neurodegeneration in ParkinsonÂŽsdisease. Here, we used brain microglial cell cultures activated by fibrillary forms of recombinanthuman αS to assess the antiâinflammatory and neuroprotective activities of the antibiotic rifampicin(Rif) and its autoxidation product rifampicin quinone (RifQ). Pretreatments with Rif and RifQreduced the secretion of prototypical inflammatory cytokines (TNFâ, ILâ6) and the burst ofoxidative stress in microglial cells activated with αS fibrillary aggregates. Note, however, that RifQwas constantly more efficacious than its parent compound in reducing microglial activation. Wealso established that the suppressive effects of Rif and RifQ on cytokine release was probably dueto inhibition of both PI3Kâ and nonâPI3Kâdependent signaling events. The control of oxidative stressappeared, however, essentially dependent on PI3K inhibition. Of interest, we also showed that RifQwas more efficient than Rif in protecting neuronal cells from toxic factors secreted by microgliaactivated by αS fibrils. Overall, data with RifQ are promising enough to justify further studies toconfirm the potential of this compound as an antiâparkinsionian drug.Fil: Acuña, Leonardo. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Salta. Instituto de PatologĂa Experimental. Universidad Nacional de Salta. Facultad de Ciencias de la Salud. Instituto de PatologĂa Experimental; Argentina. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Hamadat, Sabah. Sorbonne University; FranciaFil: Corbalan, Natalia Soledad. UniversitĂ© Paris Est CrĂ©teil; Francia. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: GonzĂĄlez Lizarraga, Maria Florencia. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Dos Santos Pereira, Mauricio. Sorbonne University; Francia. Centre National de la Recherche Scientifique; Francia. Universidade de Sao Paulo; BrasilFil: Rocca, JĂ©rĂ©my. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: SepĂșlveda DĂaz, Julia. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Del Bel, Elaine. Universidade de Sao Paulo; BrasilFil: Papy GarcĂa, Dulce. UniversitĂ© Paris Est CrĂ©teil; FranciaFil: Chehin, Rosana Nieves. Universidad Nacional de Tucuman. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Gobierno de la Provincia de Tucuman. Ministerio de Salud. Sistema Provincial de Salud. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario. - Consejo Nacional de Investigaciones Cientificas y Tecnicas. Centro Cientifico Tecnologico Conicet Noa Sur. Instituto de Investigaciones En Medicina Molecular y Celular Aplicada del Bicentenario.; ArgentinaFil: Michel, Patrick P.. Sorbonne University; Francia. Centre National de la Recherche Scientifique; FranciaFil: Raisman Vozari, Rita. Sorbonne University; Francia. Centre National de la Recherche Scientifique; Franci
Introduction to the French GEOTRACES North Atlantic transect (GA01): GEOVIDE cruise
© 2018 Author(s). The GEOVIDE cruise, a collaborative project within the framework of the international GEOTRACES programme, was conducted along the French-led section in the North Atlantic Ocean (Section GA01), between 15 May and 30 June 2014. In this special issue (https://www.biogeosciences.net/special-issue900.html), results from GEOVIDE, including physical oceanography and trace element and isotope cyclings, are presented among 18 articles. Here, the scientific context, project objectives, and scientific strategy of GEOVIDE are provided, along with an overview of the main results from the articles published in the special issue
Colonization of the Mediterranean Basin by the vector biting midge species Culicoides imicola: an old story
Understanding the demographic history and genetic make-up of colonizing species is critical for inferring population sources and colonization routes. This is of main interest for designing accurate control measures in areas newly colonized by vector species of economically important pathogens. The biting midge Culicoides imicola is a major vector of Orbiviruses to livestock. Historically, the distribution of this species was limited to the Afrotropical region. Entomological surveys first revealed the presence of C. imicola in the south of the Mediterranean basin by the 1970's. Following recurrent reports of massive bluetongue outbreaks since the 1990s, the presence of the species was confirmed in northern areas. In this study, we addressed the chronology and processes of C. imicola colonization in the Mediterranean basin. We characterized the genetic structure of its populations across Mediterranean and African regions using both mitochondrial and nuclear markers, and combined phylogeographical analyses with population genetics and approximate Bayesian computation. We found a west/east genetic differentiation between populations, occurring both within Africa and within the Mediterranean basin. We demonstrated that three of these groups had experienced demographic expansions in the Pleistocene, probably because of climate changes during this period. Finally, we showed that C. imicola could have colonized the Mediterranean basin in the late Pleistocene or early Holocene through a single event of introduction; however we cannot exclude the hypothesis involving two routes of colonization. Thus, the recent bluetongue outbreaks are not linked to C. imicola colonization event, but rather to biological changes in the vector or the virus
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Continuation vs Discontinuation of Renin-Angiotensin System Inhibitors Before Major Noncardiac Surgery
ImportanceBefore surgery, the best strategy for managing patients who are taking renin-angiotensin system inhibitors (RASIs) (angiotensin-converting enzyme inhibitors or angiotensin receptor blockers) is unknown. The lack of evidence leads to conflicting guidelines.ObjectiveTo evaluate whether a continuation strategy vs a discontinuation strategy of RASIs before major noncardiac surgery results in decreased complications at 28 days after surgery.Design, setting, and participantsRandomized clinical trial that included patients who were being treated with a RASI for at least 3 months and were scheduled to undergo a major noncardiac surgery between January 2018 and April 2023 at 40 hospitals in France.InterventionPatients were randomized to continue use of RASIs (nâ=â1107) until the day of surgery or to discontinue use of RASIs 48 hours prior to surgery (ie, they would take the last dose 3 days before surgery) (nâ=â1115).Main outcomes and measuresThe primary outcome was a composite of all-cause mortality and major postoperative complications within 28 days after surgery. The key secondary outcomes were episodes of hypotension during surgery, acute kidney injury, postoperative organ failure, and length of stay in the hospital and intensive care unit during the 28 days after surgery.ResultsOf the 2222 patients (mean age, 67 years [SD, 10 years]; 65% were male), 46% were being treated with angiotensin-converting enzyme inhibitors at baseline and 54% were being treated with angiotensin receptor blockers. The rate of all-cause mortality and major postoperative complications was 22% (245 of 1115 patients) in the RASI discontinuation group and 22% (247 of 1107 patients) in the RASI continuation group (risk ratio, 1.02 [95% CI, 0.87-1.19]; Pâ=â.85). Episodes of hypotension during surgery occurred in 41% of the patients in the RASI discontinuation group and in 54% of the patients in the RASI continuation group (risk ratio, 1.31 [95% CI, 1.19-1.44]). There were no other differences in the trial outcomes.Conclusions and relevanceAmong patients who underwent major noncardiac surgery, a continuation strategy of RASIs before surgery was not associated with a higher rate of postoperative complications than a discontinuation strategy.Trial registrationClinicalTrials.gov Identifier: NCT03374449
ANALYSES ET COMPORTEMENTS DES PARTICULES CREEES DANS UN PLASMA RADIOFREQUENCE BASSE PRESSION EN MELANGE METHANE/AZOTE.
In this work, the generation and characterization of particles in methane and methane-nitrogen radiofrequency discharges have been studied in order to understand the effect of nitrogen incorporation within the gas mixture onto the formation and the chemical structure of the carbonaceous particles. We have also analyzed the nitrogen effect of the particle behaviour on the electric characteristics of plasma. Whereas the incorporation of a small quantity of nitrogen within a methane plasma delays the particle formation without modifying their behaviour within the discharge, a greater incorporation of nitrogen ([N2]>30%) enhances the particle synthesis, modifies their behaviour within the discharge and leads to a multi-generation phenomenon for nitrogen-rich plasmas ([N2]>70%). For a particular gas mixture of 30% CH4 / 70% N2, we also put in evidence the presence of macroscopic instabilities corresponding to a phenomenon of electrostatic interactions between the two particle clouds at the cathodic and anodic sheath boundaries. These phenomena of multi-generations and instabilities were correlated with the variations of the electric characteristics of the discharge. Various characterization methods (SEM, FTIR, XPS, EDAX) are used to evidence the size modifications, the morphology and the chemical composition of the particles. These analyses show the emergence of nitrogenized bonds CN (simple, double and triple) and NH ones. For 10% CH4 / 90% N2 mixtures, we measured a N/C ratio close to 0,5. The increase of the nitrogen percentage also involves a graphitization of the particle chemical structure.Ce travail de thÚse porte sur la synthÚse et la caractérisation de poudres dans les plasmas radiofréquence basse pression de méthane et méthane-azote. Nous avons étudié le rÎle du pourcentage d'azote dans le mélange gazeux sur la formation et la structure chimique des particules carbonées. Nous avons analysé l'influence du comportement des particules sur les caractéristiques électriques du plasma. Alors que l'incorporation d'une faible quantité d'azote au sein d'un plasma de méthane retarde la formation des particules sans modifier leur comportement au sein de la décharge, une plus grande incorporation d'azote ([N2]>30%) favorise la création des particules, modifie leur comportement au sein de la décharge et conduit à un phénomÚne de multi-génération pour les plasmas les plus riches en azote ([N2]>70%). Pour un mélange gazeux particulier de 30%CH4/70%N2, nous avons aussi mis en évidence la présence d'instabilités macroscopiques correspondant à un phénomÚne d'interactions électrostatiques entre les nuages de particules en limite de gaine cathodique et anodique. Les phénomÚnes de multi-générations et d'instabilités ont été corrélés avec les variations des caractéristiques électriques du plasma. Différentes techniques d'analyses (MEB, IRTF, XPS, EDAX) sont utilisées pour mettre en évidence les modifications de la taille, de la morphologie et de la composition chimique des particules. Ces analyses nous ont permis de mettre en évidence l'émergence de liaisons azotées CN (simples, doubles et triples) et NH. Pour des mélanges 10%CH4/90%N2 nous avons mesuré un rapport N/C proche de 0,5. Cette forte incorporation d'azote entraßne une graphitisation de la structure des particules
Analyse et comportements des particules créées dans un plasma radiofréquence basse pression en mélange méthane/azote
Ce travail de thÚse porte sur la synthÚse et la caractérisation de poudres dans les plasmas radiofréquence basse pression de méthane et méthane-azote. Nous avons étudié le rÎle du pourcentage d azote dans le mélange gazeux sur la formation et la structure chimique des particules carbonées. Nous avons analysé l influence du comportement des particules sur les caractéristiques électriques du plasma. Alors que l incorporation d une faible quantité d azote au sein d un plasma de méthane retarde la formation des particules sans modifier leur comportement au sein de la décharge, une plus grande incorporation d azote ([N2]>30%) favorise la création des particules, modifie leur comportement au sein de la décharge et conduit à un phénomÚne de multi-génération pour les plasmas les plus riches en azote ([N2]>70%). Pour un mélange gazeux particulier de 30%CH4/70%N2, nous avons aussi mis en évidence la présence d instabilités macroscopiques correspondant à un phénomÚne d interactions électrostatiques entre les nuages de particules en limite de gaine cathodique et anodique. Les phénomÚnes de multi-générations et d instabilités ont été corrélés avec les variations des caractéristiques électriques du plasma. Différentes techniques d analyses (MEB, FTIR, XPS, EDAX) sont utilisées pour mettre en évidence les modifications de la taille, de la morphologie et de la composition chimique des particules. Ces analyses nous ont permis de mettre en évidence l émergence de liaisons azotées CN (simples, doubles et triples) et NH. Pour des mélanges 10%CH4/90%N2 nous avons mesuré un rapport N/C proche de 0,5. Cette forte incorporation d azote entraßne une graphitisation de la structure des particules.ORLEANS-BU Sciences (452342104) / SudocSudocFranceF
Analyse par Spectroscopie infrarouge des particules carbonées contenues dans une décharge R.F. basse pression de méthane azote
National audienc
Emerging Trends in Understanding Chemotherapy-Induced Peripheral Neuropathy
Chemotherapy-induced peripheral neuropathy (CIPN) is a major concern in oncology practice given the increasing number of cancer survivors and the lack of effective treatment. The incidence of peripheral neuropathy depends upon the anticancer drug used, but is commonly under-reported in clinical trials. Several animal models have been developed in an attempt to better characterize the pathophysiological mechanisms underlying these CIPN and to find more specific treatments. Over the past two decades, three main trends have emerged from preclinical research on CIPN. There is a compelling body of evidence that neurotoxic anticancer drugs affect the peripheral sensory nerve by directly targeting the mitochondria and producing oxidative stress, by functionally impairing the ion channels and/or by triggering immunological mechanisms through the activation of satellite glial cells. These various neurotoxic events may account for the lack of effective treatment, as neuroprotection may probably only be achieved using a polytherapy that targets all of these mechanisms. The aim of this review is to describe the clinical features of CIPN and to summarize the recent trends in understanding its pathophysiology
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