Global modelisation and local characteristics of French periurban spatial organization

International audienceThis paper aims at finding global rules about periurban spatial organization in France according to three main indexes: intensity of periurbanisation, range of periurban commutes and concentration of periurban flows. Comparing all French agglomerations with more than 5.000 jobs, we have highlighted links between the population of these agglomerations and our three indexes. That is why this research proposes statistical models to determinate periurban spatial organization according to agglomeration size. Moreover, observing the spatial repartition of residuals, we have highlighted some local characteristics in this organization. Using geographical information systems, we have tried, in this paper, to explain these local characteristics by geographic facts and historic resilience.Modélisation statistique et caractéristiques locales de l'organisation spatial de la périurbanisation en France. Cet article a pour but de modéliser l'organisation spatiale de la périurbanisation dans les 353 aires urbaines françaises selon 3 axes : l'intensité de la périurbanisation, la portée des navettes et la concentration des flux. L'analyse des résidus permet de mettre en évidence des particularités locales indépendante de la taille des agglomérations. Grâce à une analyse par SIG, certaines pistes d'explication de ces particularités sont proposées

Les effets de la mise en service des TCSP urbains sur l’organisation du transport interurbain par autocar : quel impact pour l’accessibilité des territoires d’entre deux ?

International audienceWhen an agglomeration opens a massive transit line, local authorities try to rationalise transport networks. Intercity coach routes’ terminals are moved from the city centre to suburban area, at the end of the light rail, BRT or subway line. In this organization, commuters are forced to transfer to go to city centre.This paper aims at highlighting one limit of urban mass transit transport (light rail, BRT…) and focus on accessibility from “betweenness territories” (periurban area without train station) to urban resources. Comparing 18 metropolitan areas, we have analysed integration policies (spatial integration and cost integration) between urban public transport and intercity coach routes. Then, we have tested the efficiency of several theoretical spatial integration solutions in Montpellier metropolitan area (including lane share, circular route or periurban light rail).Au nom de la rationalisation des réseaux de transport, la mise en service de TCSP au coeur des agglomérations entraîne dans certaines villes une réorganisation des réseaux de cars interurbains : les terminus des lignes sont déplacés de la gare routière centrale vers un terminus de la ligne de TCSP, en périphérie de l'agglomération. Une rupture de charge forcée est alors créée sur le trajet entre les territoires « d'entre deux » (sans desserte ferroviaire) et le centre-ville, qui est pourtant un lieu de concentration des ressources urbaines. Ce travail cherche à identifier une des limites potentielles des TCSP en s'intéressant à l'accessibilité depuis les territoires « en négatif » des réseaux dits « structurants » de transports en commun. Il s'agit alors, à partir d'un ensemble comparatif de 18 aires urbaines, d'analyser les différentes politiques d'intégration (spatiale et tarifaire) des transports départementaux et urbains. Puis, à partir de l'exemple de Montpellier, nous avons testé l'efficacité de plusieurs hypothèses d'articulation entre cars interurbains et transports urbains (mutualisation des infrastructures, desserte en rocade, tramway périurbain…). The effect of urban rapid transit on intercity coach routes: which impact for betweenness territories? Abstract: When an agglomeration opens a massive transit line, local authorities try to rationalise transport networks. Intercity coach routes' terminals are moved from the city centre to suburban area, at the end of the light rail, BRT or subway line. In this organization, commuters are forced to transfer to go to city centre. This paper aims at highlighting one limit of urban mass transit transport (light rail, BRT…) and focus on accessibility from " betweenness territories " (periurban area without train station) to urban resources. Comparing 18 metropolitan areas, we have analysed integration policies (spatial integration and cost integration) between urban public transport and intercity coach routes. Then, we have tested the efficiency of several theoretical spatial integration solutions in Montpellier metropolitan area (including lane share, circular route or periurban light rail)

Vaulting quantification during level walking of transfemoral amputees

Background: Vaulting is a gait compensatory mechanism used by transfemoral amputees to assist toe clearance during the prosthetic swing phase. It is defined by a plantar flexion of the contralateral ankle during the single-limb support phase. The aim of the study is to propose a method to quantify vaulting of transfemoral amputees. Methods: 17 transfemoral amputees and 28 asymptomatic subjects participated in the data collection. Kinematics and kinetics of thewhole bodywere recordedwhile subjectswerewalking on a level surface. Biomechanical gait analysis was focused on a reduced set of parameters linked to the contralateral ankle, the contralateral knee and the trajectory of the center of pressure. The patients were classified in two groups: with orwithout vaulting using video recordings. Differences between both groups and the control group were analyzed. Findings: A higher generated ankle powerwas found during the single support phase of the contralateral limb of transfemoralamputees presenting vaulting. These subjects presented also a higher dissipated knee flexion power before the peak in ankle flexion power. The trajectory of the center of pressurewas also modified by the vaulting. Interpretation: Vaulting for transfemoral amputees is characterized by a propulsive plantar flexion at the contralateral ankle. Quantifying the ankle flexion power during the contralateral single support phase will help in understanding vaulting.This study was supported by the French National Research Agency, under reference ANR-2010-TECS-020. The authors are deeply grateful to F. Lavaste, N. Martinet, J. Paysant, and N. Rapin for their contribution to the study

Influence d'un film de polycaprolactone fonctionnalisé par des peptides d'adhésion sur la réponse de préostéoblastes à la BMP-2 et à la BMP-9

L'efficacité des matériaux utilisés pour favoriser la régénération osseuse dépend entre autres de leur capacité d'interaction avec le tissu environnant. Ainsi, des peptides d'adhésion contenant la séquence Arginine-Glycine-Acide aspartique (RGD) sont parmi les plus utilisés pour favoriser 1'attachement des cellules osseuses au matériau. Les facteurs de croissance, dont les protéines morphogénétiques osseuses (BMPs), jouent également un rôle clé dans le processus de différenciation et de fonctionnement des cellules osseuses. La BMP-2 approuvée par la Food and Drug Administration aux États-Unis dans le cadre d'un système de libération est déjà actuellement utilisée cliniquement pour accroître la régénération osseuse. De plus, la BMP-9 a récemment suscité un grand intérêt en raison de son potentiel ostéogénique supérieur à celui de la BMP-2. Néanmoins, peu d'études se sont intéressées à l'influence des peptides d'adhésion sur la réponse cellulaire aux BMPs. Le principal objectif de ce travail de doctorat a donc été de fonctionnaliser un polymère par des peptides d'adhésion et de déterminer son impact sur la capacité de préostéoblastes de souris MC3T3-E1 à répondre à la BMP-2 et à la BMP-9. Cette étude s'est tout d'abord intéressée à la synthèse et à la caractérisàtion d'un film de polycaprolactone (PCL) fonctionnalisé par un peptide dérivé de la sialoprotéine osseuse qui contient 15 acides aminés dont la séquence RGD (pRGD). La fonctionnalisation a consisté en une hydrolyse alcaline du film PCL suivie d'un greffage covalent du pRGD. Les films PCL hydrolysés ont adsorbé des protéines sériques adhésives fibronectine et vitronectine mais sans favoriser l'étalement des préostéoblastes MC3T3-E1. En absence de sérum, les films PCL-pRGD ont permis un étalement plus important des préostéoblastes MC3T3-E1 par rapport au PCL fonctionnalisé par le pRGE (peptide négatif) ou au PCL hydrolysé. Le PCL-pRGD a augmenté le niveau de phosphorylation de la FAK (Tyr 397 ), évènement nécessaire chez les préostéoblastes murins pour permettre leur différenciation en ostéoblastes matures. Ainsi, seules les cellules adhérant au PCL-pRGD ont répondu à la BMP-2 via une activation de la voie canonique des Smads. Dans un deuxième temps, la stimulation des préostéoblastes par la BMP-2 et/ou BMP-9 a été déterminée sur PCL-pRGD. L'EC50 pour chacune des BMPs a tout d'abord été évaluée afin de choisir la concentration optimale à utiliser lors de la combinaison des BMP-2/BMP-9. Tandis que la BMP-2 a induit une phosphorylation des Smad1/5/8 dès 30 min, la BMP-9 a engendré un retard d'activation à 4 h. Cette observation était concomitante avec une diminution de la ?-caténine. Par contre, aucune différence n'a été observée avec la BMP-2 et la BMP-9 en termes d'activation des MAPKinases. Néanmoins, tant la BMP-2 que la BMP-9 ont été capables d'induire la différenciation des préostéoblastes MC3T3-E1 sur PCL-pRGD telle que mis en évidence par la synthèse d' ARNm codant pour Dlx5, Ostérix ou l'ostéocalcine et l'augmentation de l'activité de l'alcaline phosphatase à 72h. Mais l'utilisation d'une combinaison de la BMP-2 avec la BMP-9 stabilisant la ?-caténine n'a pas permis d'obtenir un effet additif sur la différenciation, des activations semblables à celles de la BMP-2 utilisée seule ayant été alors observées. En résumé, l'utilisation de BMP-2 ou de BMP-9 en combinaison avec une surface fonctionnalisée par des peptides d'adhésion semble être une voie prometteuse pour favoriser la différenciation cellulaire. Cependant, cette étude montre également que la BMP-2 et la BMP-9 induisent des voies d'activation antagonistes au contact du PCL-pRGD. Elle met donc l'emphase sur la nécessité de mieux comprendre l'influence de la fonctionnalisation de matériaux par des peptides d'adhésion sur la réponse aux facteurs de croissance

INFLUENCE OF PLAYING SURFACE ON KNEE LOADS DURING RUNNING, SIDESTEP CUTTING AND DROP JUMPING

The purpose of this study was to analyse the influence of 3 different playing surfaces on knee load during sport tasks. 15 young skilled rugby players (17-19 year old) performed running, sidestep cutting and drop jumping tasks on 3 different tracks; i.e. a natural turf, an artificial turf and an hybrid turf (natural grass rooted in artificial rootzone). Kinematic analysis and inverse dynamic methods were applied to assess the knee loads during these exercises. A special attention was paid to knee valgus and internal rotation moments related to ACL injury risk. Results showed that moment of knee valgus during running and sidestep cutting were significantly higher on artificial turf compared with natural ones (3.73 ± 1.13 vs. 1.98 ±. 0.83 N.m.kg-1). In the same way, internal rotation moments in sidestep cutting displayed higher values on artificial track than natural grass (2.97 ± 1.21 vs. 2.51 ±. 1.15 N.m.kg-1). Furthermore, hybrid turf exhibited the lowest knee moments except for the running task. In conclusion, the type of the playing surface play an important role in knee loads related to ACL injury risk

Cooperative localization of drones by using interval methods

In this article we address the problem of cooperative pose estimation in a group of unmanned aerial vehicles (UAVs) in a bounded-error context. The UAVs are equipped with cameras to track landmarks, and with a communication and ranging system to cooperate with their neighbors. Measurements are represented by intervals, and constraints are expressed on the robots poses (positions and orientations). Pose domains subpavings are obtained by using set inversion via interval analysis. Each robot of the group first computes a pose domain using only its sensors measurements. Then, through position boxes exchanges, the positions are cooperatively refined by constraint propagation in the group. Results with real robot data are presented, and show that the position accuracy is improved thanks to cooperation

Early Detection of Progressive Adolescent Idiopathic Scoliosis: A Severity Index

Study Design. Early detection of progressive adolescent idiopathic scoliosis (AIS) was assessed based on 3D quantification of the deformity. Objective. Based on 3D quantitative description of scoliosis curves, the aim is to assess a specific deformation pattern that could be an early detectable severity index for progressive AIS. Summary of Background Data. Early detection of progressive scoliosis is important for adapted treatment to limit progression. However, progression risk assessment is mainly based on the follow up, waiting for signs of rapid progression that generally occur during the growth peak. Methods. 65 mild scoliosis (16 boys, 49 girls, Cobb Angle between 10 and 20°) with a Risser between 0 and 2 were followed from their first exam until a decision was made by the clinician, either considering the spine as stable at the end of growth (26 patients) or planning to brace because of progression (39 patients). Calibrated bi-planar X-rays were performed and 3D reconstructions of the spine allowed to calculate six local parameters related to main curve deformity. For progressive curve 3D phenotype assessment, data were compared to those previously assessed for 30 severe scoliosis (Cobb Angle > 35°), 17 scoliosis before brace (Cobb Angle > 29°) and 53 spines of non-scoliosis subjects. A predictive discriminant analysis was performed to assess similarity of mild scoliosis curves either to those of scoliosis or non-scoliosis spines, yielding a severity index (S-index). S index value at first exam was compared to clinical outcome. Results. At the first exam, 53 out of 65 predictions (82%) were in agreement with actual clinical outcome. 89 % of the curves that were predicted as progressive proved accurate Conclusion. Although still requiring large scale validation, results are promising for early detection of progressive curves.The “Fondation Yves Cotrel pour la recherche en pathologie rachidienne” and the other partners of the ParisTech BiomecAM chair program on subject-specific musculoskeletal modelling (ParisTech Foundation, Société Générale, Proteor and Covea) funds were received in support of this work

Cooperative Localization of Drones by using Interval Methods

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Peptides derived from the knuckle epitope of BMP-9 induce the cholinergic differentiation and inactivate GSk3beta in human SH-SY5Y neuroblastoma cells

The incidence of brain degenerative disorders like Alzheimer's disease (AD) will increase as the world population ages. While there is presently no known cure for AD and current treatments having only a transient effect, an increasing number of publications indicate that growth factors (GF) may be used to treat AD. GFs like the bone morphogenetic proteins (BMPs), especially BMP-9, affect many aspects of AD. However, BMP-9 is a big protein that cannot readily cross the blood-brain barrier. We have therefore studied the effects of two small peptides derived from BMP-9 (pBMP-9 and SpBMP-9). We investigated their capacity to differentiate SH-SY5Y human neuroblastoma cells into neurons with or without retinoic acid (RA). Both peptides induced Smad 1/5 phosphorylation and their nuclear translocation. They increased the number and length of neurites and the expression of neuronal markers MAP-2, NeuN and NSE better than did BMP-9. They also promoted differentiation to the cholinergic phenotype more actively than BMP-9, SpBMP-9 being the most effective as shown by increases in intracellular acetylcholine, ChAT and VAchT. Finally, both peptides activated the PI3K/Akt pathway and inhibited GSK3beta, a current AD therapeutic target. BMP-9-derived peptides, especially SpBMP-9, with or without RA, are promising molecules that warrant further investigation

Patient-specific anisotropic model of human trunk based on MR data

There are many ways to generate geometrical models for numerical simulation, and most of them start with a segmentation step to extract the boundaries of the regions of interest. This paper presents an algorithm to generate a patient-specific three-dimensional geometric model, based on a tetrahedral mesh, without an initial extraction of contours from the volumetric data. Using the information directly available in the data, such as gray levels, we built a metric to drive a mesh adaptation process. The metric is used to specify the size and orientation of the tetrahedral elements everywhere in the mesh. Our method, which produces anisotropic meshes, gives good results with synthetic and real MRI data. The resulting model quality has been evaluated qualitatively and quantitatively by comparing it with an analytical solution and with a segmentation made by an expert. Results show that our method gives, in 90% of the cases, as good or better meshes as a similar isotropic method, based on the accuracy of the volume reconstruction for a given mesh size. Moreover, a comparison of the Hausdorff distances between adapted meshes of both methods and ground-truth volumes shows that our method decreases reconstruction errors faster. Copyright © 2015 John Wiley & Sons, Ltd.Natural Sciences and Engineering Research Council (NSERC) of Canada and the MEDITIS training program (´Ecole Polytechnique de Montreal and NSERC)