349 research outputs found

    Les transports de marchandises et l'urbanisme : d'une prise en compte législative à la simulation des interactions

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    De nouvelles organisations et pratiques dans les politiques urbaines et rĂ©gionales sont impulsĂ©es depuis quelques annĂ©es par un ensemble lĂ©gislatif ayant un objectif de mise en cohĂ©rence des politiques de transport, d'urbanisme et de dĂ©veloppement durable. Les transports de marchandises en ville ont ainsi Ă©tĂ© introduits dans les plans de dĂ©placements urbains avec la loi sur l'air et l'utilisation rationnelle de l'Ă©nergie du 30 dĂ©cembre 1996 et dans les schĂ©mas de cohĂ©rence territoriale relatifs Ă  la loi SolidaritĂ© et Renouvellement Urbains (SRU) du 13 dĂ©cembre 2000. Leur prise en compte est en effet nĂ©cessaire dans une optique de dĂ©veloppement durable qui requiert une approche globale et systĂ©mique des transports, de l'activitĂ© Ă©conomique et des choix de localisation. Ce cadre lĂ©gislatif favorisant une intĂ©gration des transports de marchandises en ville dans les politiques d'urbanisme sera traitĂ© dans une premiĂšre partie qui abordera Ă©galement les principales caractĂ©ristiques du transport de marchandises en milieu urbain. Dans une seconde partie, nous exposerons les orientations mĂ©thodologiques et fonctions structurelles du modĂšle FRETURB de simulation du transport de marchandises en ville, en prĂ©cisant leur cohĂ©rence vis-Ă -vis des orientations lĂ©gislatives. Nous terminerons dans un troisiĂšme temps par la prĂ©sentation de simulations d'hypothĂšses d'amĂ©nagement urbain, de logistique ou de rĂ©glementation affectant les transports de marchandises ville. L'approvisionnement en marchandises d'une agglomĂ©ration est au cƓur de sa dynamique Ă©conomique. Son dĂ©veloppement harmonieux, tant social qu'Ă©conomique, passe par une bonne rĂ©alisation des livraisons et enlĂšvements de marchandises auprĂšs des diffĂ©rents commerces et entreprises mais aussi des dĂ©placements d'achat effectuĂ©s par les particuliers. Ces transports reprĂ©sentent une part non nĂ©gligeable des dĂ©placements urbains et pĂ©riurbains, de l'ordre de 15 Ă  25% des vĂ©hicules-kilomĂštres – Ă©quivalent voitures particuliĂšres (LET, 2001). A l'instar des transports urbains de personnes, ce trafic a des impacts sur l'ensemble du systĂšme de transport en milieu urbain ainsi que sur l'usage de la voirie et les amĂ©nagements urbains. La distribution des marchandises engendre divers effets externes : pollution atmosphĂ©rique, nuisances sonores, encombrements liĂ©s Ă  la circulation et Ă  l'immobilisation sur la voirie de nombreux vĂ©hicules utilitaires. Son rĂŽle Ă©conomique indĂ©niable et sa part non nĂ©gligeable dans le trafic urbain font du transport de marchandises un des Ă©lĂ©ments dĂ©terminants de la maĂźtrise des besoins de dĂ©placements et de la circulation automobile dans les textes lĂ©gislatifs rĂ©cents. Ainsi, la loi sur l'air et l'utilisation rationnelle de l'Ă©nergie vise Ă  intĂ©grer les transports de marchandises en ville dans la constitution de bilans environnementaux et Ă  minimiser les nuisances gĂ©nĂ©rĂ©es par les transports grĂące Ă  une plus grande rationalisation de la mobilitĂ© urbaine de toute nature, des personnes comme des marchandises. Plus rĂ©cemment, la loi SRU, caractĂ©risĂ©e par une volontĂ© de traiter simultanĂ©ment de l'urbanisme, des dĂ©placements et du logement, introduit les transports de marchandises et la question du stationnement dans les schĂ©mas de cohĂ©rence territoriale et les plans locaux d'urbanisme. Elle renforce Ă©galement les plans de dĂ©placements urbains, notamment concernant l'organisation du stationnement sur voirie et le transport et la livraison des marchandises.Le transport de marchandises en ville, longtemps considĂ©rĂ© comme un " mal nĂ©cessaire ", est devenu prĂ©occupant au dĂ©but des annĂ©es 90. Une double prĂ©occupation de dĂ©veloppement et de maĂźtrise des flux a Ă©mergĂ© en lien avec le constat du dĂ©clin de la population et des activitĂ©s commerciales dans les centres-villes d'une part et la montĂ©e des prĂ©fĂ©rences environnementales d'autre part. Des outils d'analyse et de modĂ©lisation des flux urbains de marchandises ont alors Ă©tĂ© dĂ©veloppĂ©s (COST 321 meeting, 1997 ; Dufour, 2000 ; LET et GĂ©rardin Conseil, 2000). Le modĂšle FRETURB s'inscrit dans cette perspective de diagnostic de la " logistique urbaine " et de simulation des effets de mesures envisagĂ©es pour rationaliser les trafics liĂ©s aux mouvements de marchandises. Il repose sur une mĂ©thode d'investigation spĂ©cifique (Bonnafous, 2000) centrĂ©e sur une relation forte entre des enquĂȘtes de terrain auprĂšs des acteurs du fret urbain et une modĂ©lisation Ă  partir d'une unitĂ© d'observation pertinente : l'opĂ©ration de livraison/enlĂšvement des marchandises. La mĂ©thodologie se distingue radicalement de celle traditionnellement utilisĂ©e dans les modĂšles de transports de personnes. Le recours Ă  une matrice origine-destination n'a pas de signification en raison notamment de l'existence de tournĂ©es complexes de livraison. L'objet d'Ă©tude, l'opĂ©ration de livraison, s'avĂšre dĂ©terminant car il permet de caractĂ©riser l'opĂ©ration de chargement/dĂ©chargement, le vĂ©hicule utilisĂ©, l'Ă©tablissement livrĂ© et son environnement, l'occupation de la voirie Ă  l'arrĂȘt, le dĂ©placement du vĂ©hicule, le mode d'organisation de la distribution, etc. Le modĂšle FRETURB s'attache Ă  considĂ©rer les interactions entre l'organisation du systĂšme de livraison, la gestion urbaine Ă  travers les rĂ©glementations, l'activitĂ© Ă©conomique qui conditionne les stratĂ©gies logistiques de distribution et la vie de la citĂ© qui renvoie aux modes de vie, Ă  l'usage de la voirie et aux conditions d'achat. Cette capacitĂ© de diagnostic global du modĂšle et de prise en compte des interactions entre transport et urbanisme est renforcĂ©e par le dĂ©veloppement de simulations des effets de mesures logistiques ou d'amĂ©nagement. Quatre sĂ©ries de mesures affectant l'occupation de la voirie par les vĂ©hicules de livraison ont Ă©tĂ© distinguĂ©es. La premiĂšre concerne les actions sur le systĂšme logistique soit par la transformation des modes d'organisation des livraisons soit par l'adoption de nouveaux choix techniques (carburants propres, gabarit des vĂ©hicules). Ces actions agissent sur le mode de gestion du transport notamment en raison de l'essor du e-commerce (Browne, 2001 ; Patier, 2000), sur la taille des tournĂ©es ou sur les durĂ©es des diffĂ©rents types de stationnement (licite, en double file, etc.). La seconde sĂ©rie de mesures relĂšve des plans d'urbanisme et affecte l'occupation de la voirie par le jeu des dĂ©localisations et substitutions d'Ă©tablissements entre les diffĂ©rentes zones d'une agglomĂ©ration. La troisiĂšme sĂ©rie se rĂ©fĂšre Ă  des actions rĂ©glementaires : limitation d'accĂšs Ă  certains quartiers, stationnement, etc. Ces actions cherchent Ă  faciliter les livraisons grĂące Ă  une mise en cohĂ©rence des politiques d'urbanisme et de transport au travers des plans d'occupation des sols et des plans locaux d'urbanisme. La quatriĂšme sĂ©rie enfin s'inscrit dans le champ de l'amĂ©nagement urbain et porte en particulier sur la maĂźtrise de l'urbanisme commercial par le recentrage des activitĂ©s Ă©conomiques ou la crĂ©ation de centres de distribution urbains. Ces simulations permettent de rendre compte au moins partiellement de la complexitĂ© de la logistique urbaine et de ses relations Ă©troites avec les orientations en matiĂšre d'amĂ©nagement urbain, d'urbanisme commercial ou avec les mutations liĂ©es au dĂ©veloppement du commerce Ă©lectronique.Transport urbain de marchandises ; modĂ©lisation systĂ©mique ; simulations ; urbanisme ; logistique urbaine

    Resistance to Dihydroartemisinin

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    Ten Years of Valuation of the Local Impact of Atmospheric Pollution: from Scientific Assessments to Political Decisions

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    This paper focuses on the economic valuation of the impact of local air pollution. Two main issues are considered: 1. The scientific issue: what is estimated, how and why? The main studies from the nineties are presented here. Two strong issues are stressed, with the diversity of valuation methods, on the one hand, and the debates on how to take the long term into account and the discount technique, on the other. 2. The political issue: how the results from the economic field are analysed and used to establish official values for public policies? The methods used in the transport sector in three different European countries (France, Sweden and Switzerland) are studied here.To conclude, we highlight the discrepancy between these two processes and, wherever possible, offer solutions to reach better synergy.Local air pollution ; External costs ; Economic valuation ; Official values ; Public decision ; International comparison

    Lack of association between putative transporter gene polymorphisms in Plasmodium falciparum and chloroquine resistance in imported malaria isolates from Africa

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    BACKGROUND: Plasmodium falciparum drug resistance represents a major health problem in malaria endemic countries. The mechanisms of resistance are not fully elucidated. Recently, an association between putative transporter gene polymorphisms and in vitro response to chloroquine (CQ) and quinine has been reported in culture-adapted, cloned isolates from various geographical origins. However, this was not confirmed in another study performed on isolates from a defined region in Thailand. METHODS: This study tried to find an association between putative transporters gene polymorphisms with in vitro response to CQ and pfcrt genotype in isolates originating from various African countries. To avoid biases of parasites adaptation in culture, fresh isolates obtained from symptomatic, malaria-infected travellers returning from Africa to France were used. Monoclonal isolates included in the study were selected using a msp-2 fragment analysis method. In vitro susceptibility to CQ, single nucleotide polymorphisms and microsatellite polymorphisms in pfcrt, pfmdr1 and six putative transporter genes were established in 27 isolates and three reference strains. RESULTS: Polymorphism of pfcrt at positions 76 and 220 showed a significant association with in vitro chloroquine resistance (P < .02 and P < .05 respectively). Polymorphism of pfmdr1 at position 86 showed an equally significant association with in vitro chloroquine response (P < .05). No association was found between SNPs or microsatellite polymorphisms of putative transporter genes and in vitro CQR or pfcrt genotype in imported malaria isolates from Africa. CONCLUSION: The previously described association between putative transporter gene polymorphisms and in vitro response to chloroquine (CQ) was not confirmed in the present study

    Impact of Airborne Particle Size, Acoustic Airflow and Breathing Pattern on Delivery of Nebulized Antibiotic into the Maxillary Sinuses Using a Realistic Human Nasal Replica

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    International audiencePurpose:Improvement of clinical outcome in patients with sinuses disorders involves targeting delivery of nebulized drug into the maxillary sinuses. We investigated the impact of nebulization conditions (with and without 100 Hz acoustic airflow), particle size (9.9 ÎŒm, 2.8 ÎŒm, 550 nm and 230 nm) and breathing pattern (nasal vs. no nasal breathing) on enhancement of aerosol delivery into the sinuses using a realistic nasal replica developed by our team.Methods:After segmentation of the airways by means of high-resolution computed tomography scans, a well-characterized nasal replica was created using a rapid prototyping technology. A total of 168 intrasinus aerosol depositions were performed with changes of aerosol particle size and breathing patterns under different nebulization conditions using gentamicin as a marker.Results:The results demonstrate that the fraction of aerosol deposited in the maxillary sinuses is enhanced by use of submicrometric aerosols, e.g. 8.155 ± 1.476 mg/L of gentamicin in the left maxillary sinus for the 2.8 ÎŒm particles vs. 2.056 ± 0.0474 for the 550 nm particles. Utilization of 100-Hz acoustic airflow nebulization also produced a 2- to 3-fold increase in drug deposition in the maxillary sinuses (e.g. 8.155 ± 1.476 vs. 3.990 ± 1.690 for the 2.8 ÎŒm particles).Conclusions:Our study clearly shows that optimum deposition was achieved using submicrometric particles and 100-Hz acoustic airflow nebulization with no nasal breathing. It is hoped that our new respiratory nasal replica will greatly facilitate the development of more effective delivery systems in the future

    Assessing sinus aerosol deposition: benefits of SPECT-CT imaging

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    International audiencePurpose: Aerosol inhalation therapy is one of the methods to treat rhinosinusitis. However the topical drug delivery to the posterior nose and paranasal sinuses shows only limited efficiency. A precise sinusal targeting remains a main challenge for aerosol treatment of sinus disorders. This paper proposes a comparative study of the nasal deposition patterns of micron and submicron particles using planar gamma-scintigraphy imaging vs. a new 3-dimensional (3D) imaging approach based on SPECT-CT measurements. Methods: Radiolabelled nebulizations have been performed on a plastinated model of human nasal cast coupled with a respiratory pump. First, the benefits provided by SPECT-CT imaging were compared with 2D gamma-scintigraphy and radioactive quantification of maxillary sinus lavage as reference for the sonic 2.8 Όm aerosol sinusal deposition. Then, the impact on nasal deposition of various airborne particle sizes was assessed. Results: The 2D methodology overestimates aerosol deposition in the maxillary sinuses by a factor 9 whereas the 3D methodology is in agreement with the maxillary sinus lavage reference methodology. Then with the SPECT-CT approach we highlighted that the higher particle size was mainly deposited in the central nasal cavity contrary to the submicron aerosol particles (33.8 ± 0.6% of total deposition for the 2.8 Όm particles vs. 1 ± 0.3% for the 230 nm particles). Conclusion: Benefits of SPECT/CT for the assessment of radiolabelled aerosol deposition in rhinology are clearly demonstrated. This 3D methodology should be preferentially used for scintigraphic imaging of sinusal deposition in Human

    Impact of acoustic airflow nebulization on intrasinus drug deposition of a human plastinated nasal cast: New insights into the mechanisms involved

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    International audienceThe impact of 100 Hz (Hertz) acoustic frequency airflow on sinus drug deposition of aerosols was investigated using a human plastinated nasal cast. The influence of drug concentration and endonasal anatomical features on the sinus deposition enhanced by the 100 Hz acoustic airflow was also examined. Plastinated models were anatomically, geometrically and aerodynamically validated (endoscopy, CT scans, acoustic rhinometry and rhinomanometry). Using the gentamicin as a marker, 286 experiments of aerosol deposition were performed. Changes of airborne particles metrology produced under different nebulization conditions (100 Hz acoustic airflow and gentamicin concentration) were also examined. Aerodynamic and geometric investigations highlighted a global behaviour of plastinated models in perfect accordance with a nasal decongested healthy subject. The results of intrasinus drug deposition clearly demonstrated that the aerosols can penetrate into the maxillary sinuses. The 100 Hz acoustic airflow led to increase the deposition of drug into the maxillary sinuses by a factor 2-3 depending on the nebulization conditions. A differential intrasinus deposition of active substance depending on maxillary ostium anatomical features and drug concentration was emphasized. The existence of a specific transport mechanism of penetration of nebulized particles delivered with acoustic airflow was proposed

    Analysis of Several PLA2 mRNA in Human Meningiomas

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    In view of the important oncogenic action of phospholipase A2(PLA2) we investigated PLA2 transcripts in human meningiomas. Real-time PCR was used to investigate PLA2 transcripts in 26 human meningioma tumors. Results indicated that three Ca2+-dependent high molecular weight PLA2 (PLA2-IVA, PLA2-IVB, PLA2-IVC), one Ca2+-independent high molecular weight PLA2 (PLA2-VI) and five low molecular weight secreted forms of PLA2 (PLA2-IB, PLA2-IIA, PLA2-III, PLA2-V, and PLA2-XII) are expressed with PLA2-IVA, PLA2-IVB, PLA2-VI, and PLA2-XIIA as the major expressed forms. PLA2-IIE, PLA2-IIF, PLA2-IVD, and PLA2-XIIB are not detected. Plasma (PLA2-VIIA) and intracellular (PLA2-VIIB) platelet-activating factor acetylhydrolase transcripts are expressed in human meningiomas. However no difference was found for PLA2 transcript amounts in relation to the tumor grade, the subtype of meningiomas, the presence of inflammatory infiltrated cells, of an associated edema, mitosis, brain invasion, vascularisation or necrosis. In conclusion numerous genes encoding multiples forms of PLA2 are expressed in meningiomas where they might act on the phospholipid remodeling and on the local eicosanoid and/or cytokine networks

    Foster rather than biological parental telomere length predicts offspring survival and telomere length in king penguins

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    ACKNOWLEDGMENTS We are grateful to the field assistants who helped us with data collection in 2012-2013. This research was supported by the French Polar Research Institute (IPEV; program 119 ECONERGY), by the Centre National de la Recherche Scientifique (CNRS), by an International Emerging Action Grant (IEA n°203036) from the CNRS, and by the AXA Research Fund (post-doctoral fellowship to VA Viblanc). We are grateful to S Rogers and 5 anonymous reviewers for constructive and useful comments on previous drafts of the paper. DATA ACCESSIBILITY The data associated with this manuscript are available online at figshare doi: 10.6084/m9.figshare.12249902 (Viblanc et al. 2020).Peer reviewedPostprin
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