An alternative to conventional public water service : "user group networks" in a Mumbai slum

Consultable en ligne : http://www.csh-delhi.com/ops.php?idop=30CSH Occasional Paper, n° 30, 37 p. ISSN : 0972 - 357.Providing universal access to drinking water remains a formidable challenge in the cities of developing countries and all potential technical and institutional solutions need to be taken into account. By looking at the specific example of "user group networks" set up in a poor neighbourhood in the North-East of Mumbai, this article aims to highlight the ability of local communities to design and run functional systems that compensate for shortcomings in the public service. We will analyse the effective role that users play in regulating these groups at local level as well as the political-territorial implications of this type of management. After providing a clear overview of the systems that have emerged and their modus operandi, we will describe and assess them from a critical technical/economic perspective in order to suggest possible improvements. More generally, our research is part of a broader attempt to study the different ways of providing access to urban water and the legitimacy of local communities in taking the process in hand. We wish to contribute to the debate that focuses on providing a differentiated service to the inhabitants of the same city

Alternative au service public d'eau conventionnel : l'exemple des " réseaux de groupes d'usagers " d'un bidonville de Mumbai

Consultable en ligne : http://metropoles.revues.org/4462International audienceL'universalisation de l'accès à l'eau potable reste un défi majeur dans les villes du monde en développement. Face à l'ampleur de cet enjeu, toutes les initiatives techniques et institutionnelles tentant d'y répondre doivent être prises en compte. A travers l'analyse précise de " réseaux de groupes d'usagers " mis en place dans un quartier pauvre du Nord-Est de Mumbai, l'objet de cet article est de mettre en lumière la capacité des communautés locales à élaborer et gérer elles-mêmes des modes de desserte fonctionnels pour compenser les insuffisances du service public. On cherchera à questionner l'efficacité du rôle des usagers dans la régulation locale de ces " réseaux de groupes d'usagers " et les implications politico-territoriales de cette gestion. Ainsi, après avoir explicité les modalités d'émergence et de fonctionnement des dispositifs observés, leur description critique et leur évaluation technico-économique en seront faites afin d'en proposer d'éventuelles améliorations. Plus largement, cette réflexion s'inscrit dans un champ d'étude portant sur la diversité des modalités d'accès à l'eau urbaine et la légitimité des communautés locales à les prendre en charge. Elle vise à contribuer au débat sur la différenciation du service entre les habitants d'une même ville

Estudio por elementos finitos de un tratamiento por angioplastia de una arteria

Doble titulacióLa grasa y el colesterol se acumulan en el interior de las arterias lo que se denomina aterosclerosis. Debido a esta acumulación las arterias pueden bloquearse o ver reducida la sección de paso de sangre por su interior. De hecho, daños y atascos en las arterias son la mayor causa de muerte en los países industrializados. La angioplastia es la expansión de una arteria por un globo que se hincha y se vacía para eliminar el problema permanentemente. La mayoría de las angioplastias acaban con la colocación de un "stent" cardiovascular que permite que la zona ensanchada por el globo permanezca abierta durante más tiempo. Un estudio por elementos finitos ha sido realizado para investigar el comportamiento mecánico del conjunto stent-placa-arteria y la interacción entre el stent y la arteria durante la angioplastia. Por eso, se han considerado modelos sucesivos y evolutivos. Las propiedades mecánicas del stent (Acero Inoxidable) y de la arteria (modelo hiperelástico) tienen muchos impactos sobre la distribución de tensiones. Lo importante es que un stent es movido por un esfuerzo radial durante el despliegue, y en este tipo de angioplastia, es el globo que aplica el esfuerzo necesario. Así, la fuerza de despliegue del stent es la que se debe aplicar al stent para desplegarlo hasta obtener el diámetro correcto. Con el estudio se ha determinado esta fuerza que es del orden de 8 MPa. Frente a la presión sanguínea promedia (100 mm Hg) alrededor de 0,013 MPa, es una carga considerable. Por otro lado, se ha analizado el comportamiento de un stent frente a las distribuciones de tensiones, las deformaciones máximas que se pueden almacenar que corresponden a la aplicación de 18 atmósferas, eso practicando análisis hasta la rotura. Al final, un stent puede permitir que una zona con placa de ateroma recupere hasta 50 % de “luz” arterial. Se han medido los resultados en cuanto al porcentaje de estenosis restante (con el diámetro interior final de la arteria) que representa un 30 % al cabo del análisis con la presión adecuada. Esta misma presión se determina procediendo por ensayos (dicotomía). Al final, el valor de estenosis considerado no es el valor al máximo y se ha considerado una contracción elástica que alcanza los 8-10%. De hecho, la presión necesaria de despliegue depende a la vez de la geometría del stent, de sus dimensiones, del material componente del stent, de la configuración tridimensional del mallado, etc.... Así, al final, este estudio permite preguntarse sobre la realización del modelo y la consideración de los daños posibles de la arteria

A White Campion (Silene latifolia) floral expressed sequence tag (EST) library: annotation, EST-SSR characterization, transferability, and utility for comparative mapping

<p>Abstract</p> <p>Background</p> <p>Expressed sequence tag (EST) databases represent a valuable resource for the identification of genes in organisms with uncharacterized genomes and for development of molecular markers. One class of markers derived from EST sequences are simple sequence repeat (SSR) markers, also known as EST-SSRs. These are useful in plant genetic and evolutionary studies because they are located in transcribed genes and a putative function can often be inferred from homology searches. Another important feature of EST-SSR markers is their expected high level of transferability to related species that makes them very promising for comparative mapping. In the present study we constructed a normalized EST library from floral tissue of <it>Silene latifolia </it>with the aim to identify expressed genes and to develop polymorphic molecular markers.</p> <p>Results</p> <p>We obtained a total of 3662 high quality sequences from a normalized <it>Silene </it>cDNA library. These represent 3105 unigenes, with 73% of unigenes matching genes in other species. We found 255 sequences containing one or more SSR motifs. More than 60% of these SSRs were trinucleotides. A total of 30 microsatellite loci were identified from 106 ESTs having sufficient flanking sequences for primer design. The inheritance of these loci was tested via segregation analyses and their usefulness for linkage mapping was assessed in an interspecific cross. Tests for crossamplification of the EST-SSR loci in other <it>Silene </it>species established their applicability to related species.</p> <p>Conclusion</p> <p>The newly characterized genes and gene-derived markers from our <it>Silene </it>EST library represent a valuable genetic resource for future studies on <it>Silene latifolia </it>and related species. The polymorphism and transferability of EST-SSR markers facilitate comparative linkage mapping and analyses of genetic diversity in the genus <it>Silene</it>.</p

Probing of local ferroelectricity in BiFeO3 thin films and (BiFeO3)m(SrTiO3)m superlattices

Ferroelectric BiFeO3 thin films and artificial superlattices of (BiFeO3)m(SrTiO3)m (m~ 1 to 10 unit cells) were fabricated on (001)-oriented SrTiO3 substrates by pulsed laser ablation. The variation of leakage current and macroscopic polarization with periodicity was studied. Piezo force microscopy studies revealed the presence of large ferroelectric domains in the case of BiFeO3 thin films while a size reduction in ferroelectric domains was observed in the case of superlattice structures. The results show that the modification of ferroelectric domains through superlattice, could provide an additional control on engineering the domain wall mediated functional properties.Comment: 14 pages, To be published in J. Mag. Mag Mater. proceedings of EMRS 200

A revised generic classification of the tribe Sileneae (Caryophyllaceae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73198/1/j.1756-1051.2000.tb00760.x.pd

Transport properties of ybco thin films near the critical state with no applied field

Transport measurements carried out on twinned ybco films are compared to the predictions of a previously proposed model suggesting that the vortices move along the films twin boundaries that behave as rows of Josephson weak links [P.Bernstein and J.F.Hamet, J.Appl.Phys.95 (2004) 2569]. The obtained results suggest that, except if the films are very thin, the twin boundaries consist of superimposed rows of weak links with mean height,ds, whose mean length along the TBs is an universal function of T/Tc, the reduced temperature. This conclusion yields a general expression for the critical surface current density of the films as a function of T/Tc and of the number of superimposed weak links rows, while the critical current density depends on ds. A comparison of the measurements reported by various authors shows that the nature of the substrate and the growth technique have both a strong effect on ds . The existence of superimposed weak links rows is attributed to extended defects generated by y2o3 inclusions.Comment: 33 pages, 13 figures; accepted for publication in Physica

Complete genome of Bradyrhizobium sp. strain BDV5419, representative of Australian genospecies L

International audienceWe report the complete genome sequence of Bradyrhizobium sp. strain BDV5419, representative of Bradyrhizobium genospecies L, which symbiotically associates with the Australian native legume Hardenbergia violaceae and is expected to represent a novel Bradyrhizobium species. The complete genome sequence provides a genetic reference for this Australian genospecies