Sur une extension des nombres de Genocchi

AbstractWe study the sequence of polynomials Bn(x, y) defined through the recurrence B1(x, y) = 1, Bn(x, y) = (x + 1)(y + 1)Bn−1(x + 1, y + 1) − xyBn−1(x, y), which extend the Gandhi polynomials generating the Genocchi numbers. We give a combinatorial interpretation of these polynomials, and a continued fraction representation for their ordinary generating function

Extraction des paramètres électriques sur les transistors CMOS de technologies avancées

Session POSTER 3L'extraction des paramètres électriques est un point clef pour la compréhension des phénomènes physiques qui régissent le fonctionnement des transistors. La réduction des dimensions impose aujourd'hui d'adapter les méthodes d'extraction préexistantes aux nouvelles générations de dispositifs. Ainsi, nous montrons comment – à partir de courbe courant-tension ID(VG) et capacité-tension Cgc(VG) – il est possible d'extraire avec précision la mobilité à bas champ (μ0) et les résistances séries (RSD) sur des transistors ultra-courts

Qualité urbaine et ville durable à l’épreuve du renouvellement urbain. L’exemple du Grand Projet de Ville Malakoff Pré Gauchet à Nantes

Les nouvelles politiques urbaines engagées par les métropoles françaises manient abondamment nombre de thématiques en vogue, comme celles du renouvellement urbain et du développement durable, lequel reste encore surtout utilisé sur mode de l’incantation et du faire-valoir de pratiques urbanistiques. Toutefois, au-delà de leurs aspects à premier abord consensuels, ces thématiques peuvent surgir en confrontation à l’occasion de grandes opérations urbaines et révéler par-là même les enjeux, mécanismes, contraintes et logiques spatiales de la production de la ville contemporaine. C’est le cas du Grand Projet de Ville (GPV) Malakoff Pré Gauchet, une opération visant à transformer un quartier dit sensible et actuellement en phase opérationnelle dans la métropole nantaise, dans laquelle une confrontation de cet ordre se révèle à l’occasion du traitement de la qualité architecturale des produits immobiliers censés contribuer au renouvellement de l’offre et de la qualité urbaine d’un secteur de ville. Les démarches sont-elles pour autant radicalement antagoniques? La recherche d’une qualité urbaine tant architecturale qu’environnementale reste-t-elle une démarche à haute valeur ajoutée incompatible avec la question du traitement des espaces publics de proximité, la transformation des grands ensembles se situe-t-elle irrémédiablement dans d’autres sphères que celles de la sortie de nouveaux programmes immobiliers? C’est sur ces différentes questions que le présent article souhaite apporter une série d’éclairages en s’appuyant sur une approche ethnographique d’un projet urbain qui couple une lecture des transformations concrètes avec des observations de réunions et de discussions entre maîtrises d’ouvrage, maîtrises d’œuvres et concessionnaires. Il s’agit ici moins tant de viser à y formuler des solutions substantielles que de souligner les différents défis qui, par l’espace, se posent désormais à l’aménagement de quartiers urbains.The new urban development policies of the French metropolises broadly invested a various number of themes, particularly that of sustainable development which, while still employed more as a marketing argument of town planning practices, is nevertheless present in large scale urban operations. Sometimes, sustainable development joins the problems of urban renewal, as part of operations aiming at the transformation of so-called shaded quarters. It is the case of operation Malakoff Pré Gauchet, at present in operational stage in Nantes city, notably in the context of the treatment of architectural quality through the realization of property products, which should contribute to the renewal of the urban offer of this city area. But are these approaches indeed radically antagonistic? Do social projects and “sustainable City” remain practices with high added value incompatible with the question of the management of public areas, with that of the transformation of large housing estates or with that of new property programs? By following a pragmatic approach, which favors observations of meetings and debates between diverse operators of development, this article underlines how agreements can take shape beyond the difference of cultures (technical, juridical) and identifies the spatial challenges that arise today in the context of the development of urban quarters

Polycistronic Delivery of IL-10 and NT-3 Promotes Oligodendrocyte Myelination and Functional Recovery in a Mouse Spinal Cord Injury Model.

One million estimated cases of spinal cord injury (SCI) have been reported in the United States and repairing an injury has constituted a difficult clinical challenge. The complex, dynamic, inhibitory microenvironment postinjury, which is characterized by proinflammatory signaling from invading leukocytes and lack of sufficient factors that promote axonal survival and elongation, limits regeneration. Herein, we investigated the delivery of polycistronic vectors, which have the potential to coexpress factors that target distinct barriers to regeneration, from a multiple channel poly(lactide-co-glycolide) (PLG) bridge to enhance spinal cord regeneration. In this study, we investigated polycistronic delivery of IL-10 that targets proinflammatory signaling, and NT-3 that targets axonal survival and elongation. A significant increase was observed in the density of regenerative macrophages for IL-10+NT-3 condition relative to conditions without IL-10. Furthermore, combined delivery of IL-10+NT-3 produced a significant increase of axonal density and notably myelinated axons compared with all other conditions. A significant increase in functional recovery was observed for IL-10+NT-3 delivery at 12 weeks postinjury that was positively correlated to oligodendrocyte myelinated axon density, suggesting oligodendrocyte-mediated myelination as an important target to improve functional recovery. These results further support the use of multiple channel PLG bridges as a growth supportive substrate and platform to deliver bioactive agents to modulate the SCI microenvironment and promote regeneration and functional recovery. Impact statement Spinal cord injury (SCI) results in a complex microenvironment that contains multiple barriers to regeneration and functional recovery. Multiple factors are necessary to address these barriers to regeneration, and polycistronic lentiviral gene therapy represents a strategy to locally express multiple factors simultaneously. A bicistronic vector encoding IL-10 and NT-3 was delivered from a poly(lactide-co-glycolide) bridge, which provides structural support that guides regeneration, resulting in increased axonal growth, myelination, and subsequent functional recovery. These results demonstrate the opportunity of targeting multiple barriers to SCI regeneration for additive effects

PLG Bridge Implantation in Chronic SCI Promotes Axonal Elongation and Myelination.

Spinal cord injury (SCI) is a devastating condition that may cause permanent functional loss below the level of injury, including paralysis and loss of bladder, bowel, and sexual function. Patients are rarely treated immediately, and this delay is associated with tissue loss and scar formation that can make regeneration at chronic time points more challenging. Herein, we investigated regeneration using a poly(lactide-co-glycolide) multichannel bridge implanted into a chronic SCI following surgical resection of necrotic tissue. We characterized the dynamic injury response and noted that scar formation decreased at 4 and 8 weeks postinjury (wpi), yet macrophage infiltration increased between 4 and 8 wpi. Subsequently, the scar tissue was resected and bridges were implanted at 4 and 8 wpi. We observed robust axon growth into the bridge and remyelination at 6 months after initial injury. Axon densities were increased for 8 week bridge implantation relative to 4 week bridge implantation, whereas greater myelination, particularly by Schwann cells, was observed with 4 week bridge implantation. The process of bridge implantation did not significantly decrease the postinjury function. Collectively, this chronic model follows the pathophysiology of human SCI, and bridge implantation allows for clear demarcation of the regenerated tissue. These data demonstrate that bridge implantation into chronic SCI supports regeneration and provides a platform to investigate strategies to buttress and expand regeneration of neural tissue at chronic time points

Chemical and dynamical processes in the mesospheric emissive layer. First results of stereoscopic observations

[1] The mesospheric emissive layer is an efficient tracer of the dynamical processes propagating in the atmosphere at that level. CCD images in the near infrared taken from the ground at slant angles often reveal the existence of wavy fields. A series of such images has been transformed, using matrix operations, producing a downward satellite-type view that covers a circular area of radius ∼1000 km at the altitude of the layer. The Fourier characteristics of the wave system are measured using a Morlet-type wavelet generator function with horizontal wavelengths of mostly ∼20–40 km and 100–150 km and temporal periods of ∼15–30 min. An oxygen-hydrogen model is used to evaluate the response of the emissive layer to a progressive density wave. The altitude of the layer is modulated with an amplitude of ∼0.8–1.8 km when a density wave propagates vertically. The layer thickness is slightly modulated and is equal to ∼7 km. Stereoscopic pairs of photographs taken simultaneously on 8–9 September 2000 at the Château-Renard and Pic du Midi observatories are used to obtain surface maps of the emission layer barycenter altitude. A stereocorrelation method suitable for low contrast objects without discrete contours is employed. Preliminary results for areas ∼50 × 50 km2 are presented. The surface maps of the layer barycenter altitude depict the existence of waves. They show the same wavy structure and compare favorably with the maps showing the emission intensity

Recent Evolutions and Trends in the Use of Computer Aided Chemical Engineering for Educational Purposes at the University of Liège

peer reviewedThe present paper addresses the evolution and perspectives in the teaching of CAPE methods in the Department of Chemical Engineering at the University of Liège. The transition that happened in the 90ies with the arrival of commercial software is highlighted, as the learning outcomes evolved from the ability of building programs to solve chemical engineering problems towards the ability to use complex commercial software and to understand their limitations. Moreover, CAPE methods were extended to non-dedicated CAPE courses, which is illustrated here by the goals and challenges of their use in courses like “Reactor Engineering” and “Life Cycle Analysis”. It was observed that students sometimes assume that CAPE softwares provide straightforward and trustworthy solutions without the need of understanding their mathematical bases and assumptions. Thus, solutions to make students aware of these limitations are proposed, including the creation of an integrated project focussing on complex multi-disciplinary issues, evidencing the need for critical input from the operator

Combinatorial lentiviral gene delivery of pro‐oligodendrogenic factors for improving myelination of regenerating axons after spinal cord injury

Spinal cord injury (SCI) results in paralysis below the injury and strategies are being developed that support axonal regrowth, yet recovery lags, in part, because many axons are not remyelinated. Herein, we investigated strategies to increase myelination of regenerating axons by overexpression of platelet‐derived growth factor (PDGF)‐AA and noggin either alone or in combination in a mouse SCI model. Noggin and PDGF‐AA have been identified as factors that enhance recruitment and differentiation of endogenous progenitors to promote myelination. Lentivirus encoding for these factors was delivered from a multichannel bridge, which we have previously shown creates a permissive environment and supports robust axonal growth through channels. The combination of noggin+PDGF enhanced total myelination of regenerating axons relative to either factor alone, and importantly, enhanced functional recovery relative to the control condition. The increase in myelination was consistent with an increase in oligodendrocyte‐derived myelin, which was also associated with a greater density of cells of an oligodendroglial lineage relative to each factor individually and control conditions. These results suggest enhanced myelination of regenerating axons by noggin+PDGF that act on oligodendrocyte‐lineage cells post‐SCI, which ultimately led to improved functional outcomes.Spinal cord injury (SCI) results in paralysis below the injury and strategies are being developed that support axonal regrowth, yet recovery lags, in part because many axons are not remyelinated. Herein, we investigated strategies to increase myelination of regenerating axons by overexpression of platelet‐derived growth factor‐AA and noggin either alone or in combination in a mouse SCI model.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/146575/1/bit26838_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/146575/2/bit26838.pd