141 research outputs found
RĂšglement des faillites et pratiques judiciaires
Qui dit faillite dit procĂ©dure judiciaire et examen de la comptabilitĂ©. Or la lĂ©gislation, le rĂŽle et la signification de la comptabilitĂ© ont connu dâimportantes Ă©volutions au fil des siĂšcles. Pour comprendre ces mutations, qui ont pour consĂ©quence une judiciarisation des procĂ©dures et le passage Ă une logique dâexpertise, nous avons choisi de croiser analyses historique et comptable : lâĂ©tude est menĂ©e sur un temps long, de 1673, date de lâOrdonnance de commerce, premiĂšre unification du droit des marchands, Ă 1889, date de la loi qui crĂ©e la liquidation judiciaire, deux moments importants du droit des faillites. Dans ce cadre chronologique, deux angles dâapproche sont privilĂ©giĂ©s : dâune part, les pratiques sociales et judiciaires, dâautre part, les pratiques comptables, autour de la figure clĂ© du syndic qui, de marchand Ă©lu parmi ses pairs Ă la pluralitĂ© des voix, devient homme de loi, expert a priori indĂ©pendant.Bankruptcy implies the involvement of legal procedure and a comprehensive examination of accounting. Yet the legislation, the function and the meaning of accounting have changed over the last centuries. To understand these changes, which have resulted in the judicialisation of procedures and the transition to a logic of expertise, we have chosen to cross both historical and accounting analyses. Our study covers an extensive period: from 1673, the date of the first Ordonnance de commerce, which unified French mercantile law, to 1889, when the law creating the legal system of compulsory liquidation was established. Both dates are milestones in bankruptcy law. Within this chronological framework, we have given importance to two angles of approach. On the one hand, we examine social and judiciary practices; and on the other hand, we look into accounting practices, focusing on the key figure of the trustee. Once chosen by his peers in a plurality voting system, he became a court-appointed expert, with a priori independence
Synthesis of new high molecular weight phosphorylated chitosans for improving corrosion protection
Two grades of chitosan [chitosan 30000 g molâ1 (N-chitosan 30) and 250000 g molâ1 (N-chitosan 250)] were functionalized by the KabachnikâFields reaction. To obtain the highest phosphonic ester grafting rate (55% and 40% for the N-chitosan 30 and N-chitosan 250, respectively), the pH must be kept constant during the reaction (pH=5). Then, a partial hydrolysis of the ester functions was carried out in HCl medium to generate phosphonic acid functions up to 25% and 20% for the N-chitosan 30 and N-chitosan 250, respectively. It was shown that the grafting of phosphonic acids on chitosan significantly reduced the dynamic viscosity. Afterwards, electrochemical impedance measurements were performed in an aqueous solution (pH=5) in the presence of either N-chitosans or P-chitosans (3 wt.%). The two native N-chitosans were little adsorbed onto the carbon steel surface and the corrosion protection was low. In contrast, the impedance results in the presence of the 30000 g molâ1 phosphorylated chitosan (P-chitosan 30) evidenced the beneficial effect of grafted phosphonic acid on its adsorption on the steel surface. The lower efficiency of the 250000 g molâ1 (P-chitosan 250) was attributed to its high molecular weight which made difficult the interactions between the phosphonic groups and the metallic surface
Fully Automatic Lesion Localization and Characterization: Application to Brain Tumors Using Multiparametric Quantitative MRI Data
International audienceWhen analyzing brain tumors, two tasks are intrinsically linked, spatial localization and physiological characterization of the lesioned tissues. Automated data-driven solutions exist, based on image segmentation techniques or physiological parameters analysis, but for each task separately, the other being performed manually or with user tuning operations. In this work, the availability of quantitative magnetic resonance (MR) parameters is combined with advanced multivariate statistical tools to design a fully automated method that jointly performs both localization and characterization. Non trivial interactions between relevant physiological parameters are captured thanks to recent generalized Student distributions that provide a larger variety of distributional shapes compared to the more standard Gaussian distributions. Probabilistic mixtures of the former distributions are then considered to account for the different tissue types and potential heterogeneity of lesions. Discriminative multivariate features are extracted from this mixture modelling and turned into individual lesion signatures. The signatures are subsequently pooled together to build a statistical fingerprint model of the different lesion types that captures lesion characteristics while accounting for inter-subject variability. The potential of this generic procedure is demonstrated on a data set of 53 rats, with 36 rats bearing 4 different brain tumors, for which 5 quantitative MR parameters were acquired
New bio-based phosphorylated chitosan/alginate protective coatings on aluminum alloy obtained by the LbL technique
Bio-based coatings were obtained by the layer-by-layer (LbL) technique from a native chitosan (Mw â 30,000âŻg molâ1) or from two synthesized phosphorylated chitosan of different molecular weights (Mw â 30,000âŻg molâ1 and Mw â 250,000âŻg molâ1) combined with alginate and used for corrosion protection of an aluminum alloy (AA) 3003. First, the LbL growth was monitored by Fourier transform infrared spectroscopy on silicon wafers. Cross-sections of Si wafers were examined by scanning electron microscopy allowing the films thickness to be measured. With the native chitosan and in the presence of 10 bilayers, the LbL thickness was about 200âŻnm, whereas it was about 300âŻnm with the phosphorylated chitosan of low molecular weight and about 500âŻnm with the phosphorylated chitosan of high molecular weight. Then, the bio-based coatings were deposited on the AA3003 by the LbL technique and their protective properties were evaluated by electrochemical impedance spectroscopy (EIS) during immersion in a 0.1âŻM Na2SO4 solution. It was shown that the three LbL coatings improved the corrosion resistance of the AA3003. The resistance values, extracted at low frequency on the impedance diagrams were attributed to the resistance of the aluminum oxide layer (Rox). The Rox values were at least two orders of magnitude higher for the coated samples (108 Ω cm2) compared to the uncoated one (5 105 Ω cm2). There was no significant difference between the different LbL coatings, which mainly acted by decreasing the active surface area and have a limited barrier effect
An in situ intercomparison exercise on passive samplers for the monitoring of metals, polycyclic aromatic hydrocarbons and pesticides in surface water
An intercomparison exercise on passive samplers (PSs) was organized in summer 2010 for the measurement of selected metals, polycyclic aromatic hydrocarbons (PAHs) and pesticides in surface waters. Various PSs were used and compared at 2 rivers sites and one marine lagoon. A total of 24 laboratories participated. We present selected significant outputs from this exercise, including discussion on quality assurance and quality control for PSs, the interlaboratory variability of field blanks, time weighted average water concentrations and its uncertainties, the representativity of DGT samples, the ability of PSs to lower limits of detection, PAH fingerprints in various PSs compared with spot samples, and the relevance of the permeability reference compounds (PRC) approach for POCIS with pesticides. These in situ intercomparison exercises should enable to progress on the harmonization of practices for the use of passive sampling, especially for priority chemical monitoring and regulatory programs in compliance with the Water Framework Directive (WFD) and Marine Strategy Framework Directive (MSFD)
A primeira partilha da Ăfrica: decadĂȘncia e ressurgĂȘncia do comĂ©rcio portuguĂȘs na Costa do Ouro (ca. 1637-ca. 1700)
Intrahippocampale Transplantation von MSC und MSC-exprimierendem BDNF bei einem Tiermodell fĂŒr depressionsĂ€hnliches Verhalten in der Ratte
Early hypotheses on the pathophysiology of major Depression were based on
aberrant intrasynaptic concentrations of the neurotransmitters Serotonin and
Norepinephrine. However, a number of recent studies suggested that changes in
hippocampal neuroplasticity may underlie the development of Depression and the
recovery from disease. Moreover, brain-derived neurotrophic factor (BDNF) has
been proposed as one of the most promising molecular targets to stimulate
hippocampal neuroplasticity and to reverse Depression phenotypes. We
hypothesized that intrahippocampal transplantation of mesenchymal stromal
cells (MSC) from bone marrow, which are genetically engineered to express
BDNF, might offer a promising approach for the treatment of depression-like
behaviour in rodents by increasing hippocampal neuroplasticity. We used two
validated models of Depression: the Open Space Swim Test and the Learned
Helplessness paradigm. In addition, a battery of behavioural tests was
performed, namely screening of learning and memory with the 8-arm Radial Maze,
locomotion with the Open Field test and anxiety with the Elevated plus Maze.
MSC were labelled with a magnetic contrast agent (VSOP) and the transplanted
cells were tracked in vivo using Magnetic Resonance Imaging (MRI). With the
help of the thymidine analogues, BrdU and IdU, effects of MSC transplantation
on hippocampal structural plasticity were assessed by determination of cell
proliferation and survival in the Dentate Gyrus of the hippocampus.
Intrahippocampal transplantation of MSC promoted long-term changes in
hippocampal structural plasticity, but failed to provide antidepressant
effects in both models of depression-like behaviour. The most likely
explanation for our findings is the rapid immune rejection of the transplanted
allogeneic MSC in the adult brain.AnfĂ€ngliche Hypothesen bezĂŒglich der Pathophysiologie von Depression basierten
auf abweichender intrasynaptischer Konzentration der Neurotransmitter
Serotonin und Noradrenalin. Eine Zahl neuerer Studien deutet jedoch daraufhin,
dass VerÀnderungen in hippokampaler NeuroplastizitÀt der Entwicklung sowie
auch der Genesung von Depression zugrunde liegen könnten. Weiterhin wurde BDNF
(brain derived neurotrophic factor) als eines der meistversprechenden
molekularen Angriffsziele propagiert, welches hippokampale NeuroplastizitÀt
stimuliert und Depressions-PhÀnotypen umkehrt. Unsere Hypothese war, dass
intrahippokampale Transplantation mesenchymatisch-stromaler Zellen (MSC) aus
Knochenmark, die genetisch modifiziert wurden, um BDNF zu exprimieren, ein
vielversprechender Ansatz zur Behandlung von depressions-Ă€hnlichem Verhalten
sein könnte. Wir benutzten zwei Depressions-Modelle: den Open-Space-Swim-Test
und das Learned-Helplessness-Paradigma. ZusÀtzlich wurde eine Reihe
behavioraler Tests durchgefĂŒhrt, d.h. Testen von Lernen und GedĂ€chtnis mit dem
8-Arm Radial-Maze, von Lokomotion mit dem Open-Field-Test und von Angst (oder
Ăngstlichkeit?) mit dem Elevated-Plus-Maze. MSC wurden mit einem magnetischen
Kontrastmittel versehen (VSOP) und der Weg der transplantierten Zellen wurde
in vivo mit Hilfe der Magnetresonanz-tomographie (MRT) verfolgt. Mit Hilfe der
Thymidin-Analoga BrdU und IdU wurde der Effekt der MSC-Transplantation auf
hippokampale strukturelle PlastizitÀt anhand der Zell-Proliferation und
âĂberlebensrate im Gyrus Dentatus des Hippokampus geschĂ€tzt. Intrahippokampale
Transplantation von MSC begĂŒnstigte langfristige VerĂ€nderungen der
hippokampalen strukturellen PlastizitÀt, aber konnte keine antidepressiven
Effekte in einem der beiden Modelle fĂŒr depressions-Ă€hnliches Verhalten
aufweisen. Die wahrscheinlichste ErklĂ€rung dafĂŒr ist die schnell erfolgte
Immunabwehr der transplantierten allogenenen MSC im Gehirn der adulten Ratte
Uncoupling between striatal dopamine transporter and glucose metabolism in diet induced obesity
International audienceUncoupling between striatal dopamine transporter and glucose metabolism in diet induced obesity. 27th International Symposium on Cerebral Blood Flow, Metabolism and Function / 12th International Conference on Quantification of Brain Function with PE
Neurosciences
Richement illustré et particuliÚrement pédagogique, cet ouvrage, un classique du domaine, accompagné de ses compléments en ligne est la référence en neurosciences pour tout étudiant en psychologie et sciences cognitives, médecine et biologie
Exercices d'intercomparaison in situ des échantillonneurs intégratifs. Application pour l'échantillonnage de métaux, d'hydrocarbures aromatiques polycycliques et de pesticides
[Departement_IRSTEA]Eaux [TR1_IRSTEA]BELCACe rapport final prĂ©sente le cahier des charges et l'organisation pour la rĂ©alisation d'exercices d'intercomparaison d'Ă©chantillonneurs intĂ©gratifs in situ, ainsi quâune synthĂšse sur les rĂ©sultats obtenus et les produits de valorisation et de diffusion de ces rĂ©sultats. Il s'agit d'exercices collaboratifs entre laboratoires experts pour Ă©valuer l'applicabilitĂ© des Ă©chantillonneurs intĂ©gratifs dans le cadre des programmes de surveillance de la Directive cadre sur lâeau (DCE). Les campagnes d'Ă©chantillonnage se sont dĂ©roulĂ©es entre avril et juillet 2010 pour la mesure de plusieurs familles de substances prioritaires dans des eaux de surface : hydrocarbures aromatiques polycycliques (HAP), pesticides et mĂ©taux. Les outils testĂ©s incluent des POCIS (Polar Organic Chemical Integrative Sampler), SPMD (Semi-Permeable membrane Device), membranes (LDPE, silicone), Chemcatcher, MESCO (Membrane-Enclosed Sorptive Coating) pour les contaminants organiques et la DGT (Diffusive Gradient in Thin Film) pour les mĂ©taux. Deux sites d'eaux douces (Beillant, Charente maritime et Ternay, RhĂŽne) et un site d'eaux marines (Thau, HĂ©rault) ont Ă©tĂ© Ă©chantillonnĂ©s. Au total, 24 laboratoires ont participĂ© Ă l'exercice, dont 13 laboratoires Ă©trangers. Les durĂ©es d'exposition ont Ă©tĂ© fixĂ©es Ă 7 jours pour les mĂ©taux, 14 jours pour les pesticides et 21 jours pour les HAP. Les Ă©chantillonneurs ont Ă©tĂ© exposĂ©s en triplicats afin d'estimer la rĂ©pĂ©tabilitĂ© de l'Ă©chantillonnage. Pour Ă©valuer la pertinence de ces Ă©chantillonneurs intĂ©gratifs, des laboratoires rĂ©fĂ©rents Ă©taient responsables de lâanalyse des molĂ©cules dans les Ă©chantillons d'eaux collectĂ©s pendant les campagnes de terrain. Par ailleurs, pour avoir des Ă©lĂ©ments d'interprĂ©tation des rĂ©sultats, nous avons mesurĂ© rĂ©guliĂšrement la vitesse du courant, la tempĂ©rature et les paramĂštres physico-chimiques du milieu. Enfin, nous avons mis en place des contrĂŽles qualitĂ©, notamment pour contrĂŽler lâĂ©tape finale dâanalyse des laboratoires participants. Les rĂ©sultats obtenus apportent des Ă©lĂ©ments sur lâĂ©valuation des concentrations dans lâeau moyennĂ©e sur la durĂ©e dâexposition et leurs variabilitĂ©s, la comparaison entre diffĂ©rents outils dâĂ©chantillonnage intĂ©gratifs et avec un Ă©chantillonnage classique ponctuel en terme dâempreinte de contamination, de limite de quantification et de fraction Ă©chantillonnĂ©e. Afin de promouvoir ces outils dâĂ©chantillonnage, nous pensons quâil est nĂ©cessaire de statuer plus clairement sur ce quâils permettent de faire et aussi sur ce quâils ne permettent pas de faire ; de mieux dĂ©finir quel(s) Ă©chantillonneur(s) intĂ©gratif(s) pour quel(s) objectif(s). Pour Ă©tendre leur utilisation en routine, nous estimons quâil manque encore de protocoles dĂ©taillĂ©s sur leur utilisation avec description des contrĂŽles qualitĂ© ou de la dĂ©marche qualitĂ© Ă suivre ; et, si lâobjectif est dâĂ©valuer une concentration dans lâeau moyennĂ©e sur la durĂ©e dâexposition, sur les PRC Ă utiliser et les modĂšles/Ă©quations Ă appliquer. Ces exercices dâintercomparaison donnent des Ă©lĂ©ments de rĂ©ponse et des pistes Ă suivre pour favoriser lâutilisation plus large de ces outils dans le cadre de programme de surveillance des eaux. Ces exercices d'intercomparaison permettent Ă©galement de donner des Ă©lĂ©ments complĂ©mentaires au livrable AQUAREF 2011 sur "l'applicabilitĂ© des Ă©chantillonneurs intĂ©gratifs dans le cadre de la surveillance DCE"
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