trans-Polyacetylene on sodium and cesium mordenites: a resonance Raman spectroscopic study

Sodium and cesium mordenite (denoted NaM and CsM, respectively) were investigated as potential catalysts for the synthesis of polyacetylene ((CH) x). Both were successful in initiating polymerization of purified gaseous acetylene at room temperature as evidenced by Raman spectroscopic studies. The polyacetylene synthesised in this way exhibited resonance enhancement of the polyene skeletal vibrations. trans-Polyacetylene, but no cis-(CH) x, was detected. As no apparent coloration of the NaM and CsM substrates accompanied the formation of trans-(CH) x it was concluded that only small quantities of the polymer were present. The number of conjugated double bonds was estimated from the frequencies of the Raman active C-C and C=C stretching vibrations, and it was shown that the trans-(CH) x formed on CsM has a distribution of conjugation lengths ranging from less than 6 to at least 30 double bonds. The polyacetylene formed on NaM was significantly shorter and was produced in lower yields than that synthesized on CsM. "Sliced" resonance excitation profiles of polyacetylene formed on CsM were obtained using nearly 40 different excitation wavelengths and these confirmed that the adsorbed trans-(CH) x was composed of segments having a distribution of conjugated lengths. The architecture of the mordenite pore system permitted only a single polymer molecule per channel, thereby preventing cross-linking. Raman spectroscopic studies of the effects of exposure to air revealed that progressive oxidative degradation occurred with a reduction in the number of conjugated double bond

The effect of polystyrene sodium sulfonate grafting on polyethylene terephthalate artificial ligaments on in vitro mineralisation and in vivo bone tissue integration

This study investigates the impact of polystyrene sodium sulfonate (PolyNaSS) grafting onto the osseo-integration of a polyethylene terephthalate artificial ligament (Ligament Advanced Reinforcement System, LARS™) used for Anterior Cruciate Ligament (ACL). The performance of grafted and non-grafted ligaments was assessed in vitro by culturing human osteoblasts under osteogenic induction and this demonstrated that the surface modification was capable of up-regulating the secretion of ALP and induced higher level of mineralisation as measured 6 weeks post-seeding by Micro-Computed Tomography. Grafted and non-grafted LARS™ were subsequently implanted in an ovine model for ACL reconstruction and the ligament-to-bone interface was evaluated by histology and biomechanical testings 3 and 12 months post-implantation. The grafted ligaments exhibited more frequent direct ligament-to-bone contact and bone formation in the core of the ligament at the later time point than the non-grafted specimens, the grafting also significantly reduced the fibrous encapsulation of the ligament 12 months post-implantation. However, this improved osseo-integration was not translated into a significant increase in the biomechanical pull-out loads. These results provide evidences that PolyNaSS grafting improved the osseo-integration of the artificial ligament within the bone tunnels. This might positively influence the outcome of the surgical reconstructions, as higher ligament stability is believed to limit micro-movement and therefore permits earlier and enhanced healing.

Selection et controle de modes de deplacement pour un robot mobile autonome en environnements naturels

Autonomous navigation and locomotion of a mobile robot in natural environments remain a rather open issue. Several functionalities are required to complete the usual perception/decision/action cycle. They can be divided in two main categories : navigation (perception and decision about the movement) and locomotion (movement execution). In order to be able to face the large range of possible situations in natural environments, it is essential to make use of various kinds of complementary functionalities, defining various navigation and locomotion modes. Indeed, a number of navigation and locomotion approaches have been proposed in the literature for the last years, but none can pretend being able to achieve autonomous navigation and locomotion in every situation. Thus, it seems relevant to endow an outdoor mobile robot with several complementary navigation and locomotion modes. Accordingly, the robot must also have means to select the most appropriate mode to apply. This thesis proposes the development of such a navigation/locomotion mode selection system, based on two types of data: an observation of the context to determine in what kind of situation the robot has to achieve its movement and an evaluation of the behavior of the current mode, made by monitors which influence the transitions towards other modes when the behavior of the current one is considered as non satisfying. Hence, this document introduces a probabilistic framework for the estimation of the mode to be applied, some navigation and locomotion modes used, a qualitative terrain representation method (based on the evaluation of a difficulty computed from the placement of the robot's structure on a digital elevation map), and monitors that check the behavior of the modes used (evaluation of rolling locomotion efficiency, robot's attitude and configuration watching. . .). Some experimental results obtained with those elements integrated on board two different outdoor robots are presented and discussed.

Proposing and developing a definition and conceptual framework for health care resilience to cope with disasters [Resiliencia: Propuesta y desarrollo de la definicion y del marco conceptual en relacion a los desastres en el ambito sanitario]

La creación del término resiliencia en salud es un paso importante hacia la construcción de comunidades más resilientes para afrontar mejor los desastres futuros. Hasta la fecha, sin embargo, parece que hay poca literatura sobre cómo el concepto de resiliencia en salud debe ser definido. Este artículo tiene como objetivo construir un enfoque de gestión de desastres de salud integral guiado por el concepto de resiliencia. Se realizaron busquedas en bases de datos electrónicas de salud para recuperar publicaciones críticas que pueden haber contribuido a los fines y objetivos de la investigación. Un total de 61 publicaciones se incluyeron en el análisis final de este documento, que se centraron en aquéllas que proporcionan una descripción completa de las teorías y definiciones de resiliencia ante los desastres y las que proponen una definición y un marco conceptual para la capacidad de resiliencia en salud. La resiliencia es una capacidad inherente de adaptación para hacer frente a la incertidumbre del futuro. Esto implica el uso de múltiples estrategias, un enfoque de riesgos máximos y tratar de lograr un resultado positivo a través de la vinculación y cooperación entre los distintos elementos de la comunidad. Resiliencia en salud puede definirse como la capacidad de las organizaciones de salud para resistir, absorber, y responder al impacto de los desastres, mientras mantiene las funciones esenciales y se recupera a su estado original o se adapta a un nuevo estado. Puede evaluarse por criterios como la robustez, la redundancia, el ingenio y la rapidez e incluye las dimensiones clave de la vulnerabilidad y la seguridad, los recursos y la preparación para casos de desastre, la continuidad de los servicios esenciales de salud, la recuperación y la adaptación. Este nuevo concepto define las capacidades en gestión de desastres de las organizaciones sanitarias, las tareas de gestión, actividades y resultados de desastres juntos en una visión de conjunto integral, y utiliza un enfoque integrado y con un objetivo alcanzable. Se necesita urgentemente investigación futura de su medición

Nedd4-2(NEDD4L) controls intracellular Na(+)-mediated activity of voltage-gated sodium channels in primary cortical neurons.

Nedd4-2, a HECT (homologous with E6-associated protein C-terminus)-type ubiquitin protein ligase, has been implicated in regulating several ion channels, including Navs (voltage-gated sodium channels). In Xenopus oocytes Nedd4-2 strongly inhibits the activity of multiple Navs. However, the conditions under which Nedd4-2 mediates native Nav regulation remain uncharacterized. Using Nedd4-2-deficient mice, we demonstrate in the present study that in foetal cortical neurons Nedd4-2 regulates Navs specifically in response to elevated intracellular Na(+), but does not affect steady-state Nav activity. In dorsal root ganglia neurons from the same mice, however, Nedd4-2 does not control Nav activities. The results of the present study provide the first physiological evidence for an essential function of Nedd4-2 in regulating Navs in the central nervous system.

Structures of μOconotoxins from Conusmarmoreus. Inhibitors of tetrodotoxin (TTX)-sensitive and TTX-resistant sodium channels in mammalian sensory neurons

The μO-conotoxins are an intriguing class of conotoxins targeting various voltage-dependent sodium channels and molluscan calcium channels. In the current study, we have shown MrVIA and MrVIB to be the first known peptidic inhibitors of the transient tetrodotoxin-resistant (TTX-R) Na+ current in rat dorsal root ganglion neurons, in addition to inhibiting tetrodotoxin-sensitive Na+ currents. Human TTX-R sodium channels are a therapeutic target for indications such as pain, highlighting the importance of the μO-conotoxins as potential leads for drug development. Furthermore, we have used NMR spectroscopy to provide the first structural information on this class of conotoxins. MrVIA and MrVIB are hydrophobic peptides that aggregate in aqueous solution but were solubilized in 50% acetonitrile/water. The three-dimensional structure of MrVIB consists of a small β-sheet and a cystine knot arrangement of the three-disulfide bonds. It contains four backbone “loops” between successive cysteine residues that are exposed to the solvent to varying degrees. The largest of these, loop 2, is the most disordered part of the molecule, most likely due to flexibility in solution. This disorder is the most striking difference between the structures of MrVIB and the known δ- and ω-conotoxins, which along with the μO-conotoxins are members of the O superfamily. Loop 2 of ω-conotoxins has previously been shown to contain residues critical for binding to voltage-gated calcium channels, and it is interesting to speculate that the flexibility observed in MrVIB may accommodate binding to both sodium and molluscan calcium channels.

Coordination polymeric structures in the sodium salt of 4-chloro-3-nitrobenzoic acid and the sodium and potassium salts of 4-nitroanthranilic acid

The structures of the hydrated sodium salts of 4-chloro-3-nitrobenzoic acid {poly[aqua(μ4-4-chloro-3-nitrobenzoato)sodium(I)], [Na(C7H3ClNO4)(H2O)]n, (I)} and 2-amino-4-nitrobenzoic acid {poly[μ-aqua-aqua(μ3-2-amino-4-nitrobenzoato)sodium(I)], [Na(C7H5N2O4)(H2O)2]n, (II)}, and the hydrated potassium salt of 2-amino-4-nitrobenzoic acid {poly[μ-aqua-aqua(μ5-2-amino-4-nitrobenzoato)potassium(I)], [K(C7H5N2O4)(H2O)]n, (III)} have been determined and their complex polymeric structures described. All three structures are stabilized by intra- and intermolecular hydrogen bonding and strong π–π ring interactions. In the structure of (I), the distorted trigonal bipyrimidal NaO5 coordination polyhedron comprises a monodentate water molecule and four bridging carboxylate O-atom donors, generating a two-dimensional polymeric structure lying parallel to (001). Intra-layer hydrogen-bonding associations and strong inter-ring π–π interactions are present. Structure (II) has a distorted octahedral NaO6 stereochemistry, with four bridging O-atom donors, two from a single carboxylate group and two from a single nitro group and three from the two water molecules, one of which is bridging. Na centres are linked through centrosymmetric four-membered duplex water bridges and through 18-membered duplex head-to-tail ligand bridges. Similar centrosymmetric bridges are found in the structure of (III), and in both (II) and (III) strong inter-ring π–π interactions are found. A two-dimensional layered structure lying parallel to (010) is generated in (II), whereas in (III) the structure is three-dimensional. With (III), the irregular KO7 coordination polyhedron comprises a doubly bridging water molecule, a single bidentate bridging carboxylate O-atom donor and three bridging O-atom donors from the two nitro groups. A three-dimensional structure is generated. These coordination polymer structures are among the few examples of metal complexes of any type with either 4-chloro-3-nitrobenzoic acid or 4-nitroanthranilic acid.

From democracy in America to a la francaise accountability. Grasping the sociopolitical origins of accountability [De la démocratie en Amérique du Nord à l’accountability à la française]

Whilst native French speakers oftentimes collapse accountability to account giving, this paper outlines the shape of an accountability ala française. Reading Tocqueville’s (1835) work highlights that accountability as practiced in Anglo-Saxonc countries has been an offspring of American democracy. An accountability a la française would be characterised by conformance to a set or universal values, the submission of minorities to choices made by the majority, a means obligation as well as the rejection of transparency. [Alors que le francophone réduit généralement l’accountability à la reddition de comptes, cet article esquisse les contours d’une véritable accountability à la française. La lecture de Tocqueville (1835) révèle que l’accountability pratiquée dans les pays anglo-saxons trouve ses origines dans les fondements de la démocratie américaine. En France, l’accountability serait caractérisée par le respect d’un ensemble de valeurs universelles, l’adhésion des minorités aux choix majoritaires, l’absence de discriminations, une obligation de moyens et un rejet de la transparence.]

Víctimas de un experimento: Conflicto multicultural en el programa de oportunidades

This article presents a reflection of the application of multiculturality principles into tertiary educational programs at the University of Los Andes, Bogota Colombia. The main focus of this paper is debating the concept of 'positive discrimination' as a challenge taken by educational centres in societies with cultural diversity populations.

Control social y familia en el siglo XIX colombiano : una aproximación a distintas prácticas de regulación estatal

This article explores a number of social control strategies on individuals and families actioned by the newly created state-national project during the first decades of Colombian XIX century. With special attention on the discourse of urbanity, also named 'civility or good manners', this paper analyses literary sources produced in the time for molding citizens behaviors in order to incorporate the society into the new paradigm of Modernity.

Programa Piloto de Diseño Promoción y Desarrollo de Productos con Alto Valor Agregado en la Empresa Peruana

Este proyecto se desarrollo por iniciativa de las autoras y con el apoyo de un grupo interdisciplinario, con el interés común de desarrollar una investigación académica cuyo resultado sea de utilidad para el desarrollo del sector productivo artesanal Peruano. El proceso de investigación nace a partir de una observación de campo acerca de la problemática del producto artesanal Peruana y enfocada en los aspectos comerciales, de diseño y producción. Esta observación se centro en Cajamarca (por ser el departamento menos intervenido por otras investigaciones en este tema) en la zona de Aylambo y Cruz Blanca, en los talleres artesanales que desarrollan productos cerámicos. A partir de un análisis de tipo FODA de los productos y de su contexto de desarrollo, encontramos que los artesanos que trabajan con los empresarios exportadores, requieren un tipo de capacitación que les permita desarrollar su trabajo mediante un proceso orientado a cumplir con exigencias técnicas y de diseño para el desarrollo de productos validos como oferta exportable. Como punto de partida se recurrió a las instituciones no gubernamentales y del gobierno, que promueven el sector artesanal Peruano (Prompex, Adex, Proyecto PARA, IMPART) para conocer su opinión respecto a los mercados objetivos de este sector, y para adoptar como parte del proyecto, lo vigente respecto a las políticas y planes de comercialización. Para entender la contraparte comercial de este sector artesanal recurrimos a empresas privadas exportadoras con muchos años de experiencia, para ello contamos con la colaboración de empresas como Allpa, Manos Amigas, Novica. A partir de la observación de campo preliminar y de la información recogida de los expertos consultados, se realizo un diagnostico de la situación productiva en este sector. En base a la definición del problema, se establecieron las estrategias y metodologías para el diseño de la investigación, siendo parte de estas estrategias, la realización de un taller de desarrollo de productos en Cajamarca. Las estrategias tuvieron como enfoque principal la definición de metodologías de trabajo, cuya aplicación sea posible en el marco del contexto económico, político y cultural en el que se desarrolla este sector en la realidad inmediata del país. El proyecto culmina con la presentación de una propuesta que mas allá de abarcar únicamente lo metodológico en el área del diseño, presenta también ‘modelos’ de trabajo entre los diferentes actores que intervienen en el sector, de manera que a través de estrategias colaborativas se pueda potenciar el crecimiento del sector y beneficiar el desarrollo del artesano.

Accumulation of heme oxygenase-1 (HSP32) in Xenopus laevis A6 kidney epithelial cells treated with sodium arsenite, cadmium chloride or proteasomal inhibitors

The present study examined the effect of sodium arsenite, cadmium chloride, heat shock and the proteasomal inhibitors MG132, withaferin A and celastrol on heme oxygenase-1 (HO-1; also known as HSP32) accumulation in Xenopus laevis A6 kidney epithelial cells. Immunoblot analysis revealed that HO-1 accumulation was not induced by heat shock but was enhanced by sodium arsenite and cadmium chloride in a dose- and time-dependent fashion. Immunocytochemistry revealed that these metals induced HO-1 accumulation in a granular pattern primarily in the cytoplasm. Additionally, in 20% of the cells arsenite induced the formation of large HO-1-containing perinuclear structures. In cells recovering from sodium arsenite or cadmium chloride treatment, HO-1 accumulation initially increased to a maximum at 12h followed by a 50% reduction at 48 h. This initial increase in HO-1 levels was likely the result of new synthesis as it was inhibited by cycloheximide. Interestingly, treatment of cells with a mild heat shock enhanced HO-1 accumulation induced by low concentrations of sodium arsenite and cadmium chloride. Finally, we determined that HO-1 accumulation was induced in A6 cells by the proteasomal inhibitors, MG132, withaferin A and celastrol. An examination of heavy metal and proteasomal inhibitor-induced HO-1 accumulation in amphibians is of importance given the presence of toxic heavy metals in aquatic habitats.

[Den musikindustriella förändringen fortsätter och en tjänstebaserad musikekonomi börjar ta form] [in Swedish]

Det har nu gått mer än tio år sedan en student vid Northeastern University i USA lanserade den första fildelningstjänsten som blev framgångsrik bland den breda allmänheten (e.g. Alderman 2001). Lanseringen av tjänsten, som kallades Napster, ses ofta som inledningen på ett av de mest dramatiska decennierna i musikbranschens historia. En lång rad internetbaserade tjänster som följt i Napsters spår har gjort det möjligt att sprida musik till miljontals användare utan att upphovsmän och rättighetsinnehavare fått någon ersättning. Katt-och-råtta-leken mellan lagstiftning och teknik har varit intensiv och har utvecklats till ett av decenniets allra hetaste diskussionsämnen bland politiker och ledarskribenter. Försäljningen av inspelad musik har sjunkit dramatiskt och musikbranschen har tvingats ifrågasätta många väletablerade sanningar. Det här kapitlet belyser ett antal fundamentala aspekter av denna förändring och utforskar några av den ”nya” musikbranschens viktigaste karaktäristika. Under den tid som musikbranschen har beforskats har vanligtvis betoningen legat på fonogrammen, det vill säga den del av branschen som rör produktion och konsumtion av inspelad musik. På grund av branschens förändrade struktur kommer dock det här kapitlet att vidga perspektivet en smula och även inkludera musikbranschens andra delar som exempelvis konserter och förlagsverksamhet...

Mechanical bending properties of sodium titanate (Na2Ti3O7) nanowires

We report on the mechanical properties of sodium titanate nanowires (Na2Ti3O7 NW) through a combination of bending experiments and theoretical analysis. Na2Ti3O7 NWs with lateral dimensions ranging from 20–700 nm were synthesized by a hydrothermal approach. A focused ion beam (FIB) was used to manipulate the selected Na2Ti3O7 NW over a hole drilled in an indium tin oxide substrate. After welding the nanowire, a series of bending tests was performed. It was observed that the Na2Ti3O7 NW exhibits a brittle behavior, and a nonlinear elastic deformation was observed before failure. By using the modified Euler–Bernoulli beam theory, such nonlinear elastic deformation is found to originate from a combination of surface effects and axial elongation (arising from the bending deformation). The effective Young's modulus of the Na2Ti3O7 NW was found to be independent of the wire length, and ranges from 21.4 GPa to 45.5 GPa, with an average value of 33 ± 7 GPa. The yield strength of the Na2Ti3O7 NW is measured at 2.7 ± 0.7 GPa.