Controlled Anisotropic Deformation of Ag Nanoparticles by Si Ion Irradiation

The shape and alignment of silver nanoparticles embedded in a glass matrix is controlled using silicon ion irradiation. Symmetric silver nanoparticles are transformed into anisotropic particles whose larger axis is along the ion beam. Upon irradiation, the surface plasmon resonance of symmetric particles splits into two resonances whose separation depends on the fluence of the ion irradiation. Simulations of the optical absorbance show that the anisotropy is caused by the deformation and alignment of the nanoparticles, and that both properties are controlled with the irradiation fluence.Comment: Submitted to Phys. Rev. Lett. (October 14, 2005

In Situ Label-Free Study of Protein Adsorption on Nanoparticles

[Image: see text] Improving the design of nanoparticles for use as drug carriers or biosensors requires a better understanding of the protein–nanoparticle interaction. Here, we present a new tool to investigate this interaction in situ and without additional labeling of the proteins and/or nanoparticles. By combining nonresonant second-harmonic light scattering with a modified Langmuir model, we show that it is possible to gain insight into the adsorption behavior of blood proteins, namely fibrinogen, human serum albumin, and transferrin, onto negatively charged polystyrene nanoparticles. The modified Langmuir model gives us access to the maximum amount of adsorbed protein, the apparent binding constant, and Gibbs free energy. Furthermore, we employ the method to investigate the influence of the nanoparticle size on the adsorption of human serum albumin and find that the amount of adsorbed protein increases more than the surface area per nanoparticle for larger diameters

Comment on a recent sensitivity analysis of radial base function and multi-layer feed-forward neural network models - Response

Contains fulltext : 112420.pdf (publisher's version ) (Open Access

String tension in gonihedric 3D Ising models

For the 3D gonihedric Ising models defined by Savvidy and Wegner the bare string tension is zero and the energy of a spin interface depends only on the number of bends and self-intersections, in antithesis to the standard nearest-neighbour 3D Ising action. When the parameter kappa weighting the self-intersections is small the model has a first order transition and when it is larger the transition is continuous. In this paper we investigate the scaling of the renormalized string tension, which is entirely generated by fluctuations, using Monte Carlo simulations This allows us to obtain an estimate for the critical exponents alpha and nu using both finite-size-scaling and data collapse for the scaling function.Comment: Latex + postscript figures. 8 pages text plus 7 figures, spurious extra figure now removed

SL para la Gestión por Procesos y Resultados en la DGR de Misiones

Conocer y ordenar la “Gestión por Resultados” del Organismo, identificando sus modelos: Organizacional, de Procesos, Comunicacional, Flujo de Trabajo y Datos. Introducir el nuevo modelo de gestión en un Portal, transitando etapas de fortalecimiento y mejora en la prestación de Servicios a la Comunidad(Cadena de Valor Público), modelando sus Procesos en el paradigma BPM(Business Process Modeling), construidos y ejecutados en entornos web/móvil: unificados, sencillos y amigables. El usuario interno o externo, hace uso efectivo de las nTIC, minimizando la brecha digital al ser asistido por Tutores, para conformar un verdadera Sociedad del Conocimiento. Las autoridades cuentan con Información para: Control de Gestión, mejora e innovación permanente, toma de decisiones, automatización y proactividad(BP-Roules, reglas gestionadas por Usuarios). Se vuelca la Gestión mediante Procesos Catalogados, conformando “Modelos de Negocios”, identificando buenas prácticas, generando Base de Conocimientos a ser replicada en organizaciones similares, a bajo costo y en pocos meses. Los catálogos permiten ordenar toda la Oferta del Organismo, simplificando navegar y ejecutar tareas bajo diferentes perfiles de Usuarios (menú personalizado). Un único sistema integral e integrado en el Estado, remplazando sistemas y sitios: obsoletos, costosos, desconectados y desactualizados. Utilizando Software e Intercambio de Conocimiento Libre, junto a estándares globales.Sociedad Argentina de Informática e Investigación Operativ

La Gestión por Procesos y Resultados en la DGR de Misiones

Conocer y ordenar la “Gestión por Resultados” del Organismo, identificando sus modelos: Organizacional, de Procesos, Comunicacional, Flujo de Trabajo y Datos. Introducir el nuevo modelo de gestión en un Portal, transitando etapas de fortalecimiento y mejora en la prestación de Servicios a la Comunidad (Cadena de Valor Público), modelando sus Procesos en el paradigma BPM (Business Process Modeling), construidos y ejecutados en entornos web/móvil: unificados, sencillos y amigables. El usuario interno o externo, hace uso efectivo de las nTIC, minimizando la brecha digital al ser asistido por Tutores, para conformar una verdadera Sociedad del Conocimiento. Las autoridades cuentan con Información para: Control de Gestión, mejora e innovación permanente, toma de decisiones, automatización y proactividad (BP-Roules, reglas gestionadas por Usuarios). Se vuelca la Gestión mediante Procesos Catalogados, conformando “Modelos de Negocios”, identificando buenas prácticas, generando Base de Conocimientos a ser replicada en organizaciones similares, a bajo costo y en pocos meses. Los catálogos permiten ordenar toda la Oferta del Organismo, simplificando navegar y ejecutar tareas bajo diferentes perfiles de Usuarios (menú personalizado). Un único sistema integral e integrado en el Estado, remplazando sistemas y sitios: obsoletos, costosos, desconectados y desactualizados. Utilizando Software e Intercambio de Conocimiento Libre, junto a estándares globales.Sociedad Argentina de Informática e Investigación Operativ

Surfactant-like Effect and Dissolution of Ultrathin Fe Films on Ag(001)

The phase immiscibility and the excellent matching between Ag(001) and Fe(001) unit cells (mismatch 0.8 %) make Fe/Ag growth attractive in the field of low dimensionality magnetic systems. Intermixing could be drastically limited at deposition temperatures as low as 140-150 K. The film structural evolution induced by post-growth annealing presents many interesting aspects involving activated atomic exchange processes and affecting magnetic properties. Previous experiments, of He and low energy ion scattering on films deposited at 150 K, indicated the formation of a segregated Ag layer upon annealing at 550 K. Higher temperatures led to the embedding of Fe into the Ag matrix. In those experiments, information on sub-surface layers was attained by techniques mainly sensitive to the topmost layer. Here, systematic PED measurements, providing chemical selectivity and structural information for a depth of several layers, have been accompanied with a few XRD rod scans, yielding a better sensitivity to the buried interface and to the film long range order. The results of this paper allow a comparison with recent models enlightening the dissolution paths of an ultra thin metal film into a different metal, when both subsurface migration of the deposit and phase separation between substrate and deposit are favoured. The occurrence of a surfactant-like stage, in which a single layer of Ag covers the Fe film is demonstrated for films of 4-6 ML heated at 500-550 K. Evidence of a stage characterized by the formation of two Ag capping layers is also reported. As the annealing temperature was increased beyond 700 K, the surface layers closely resembled the structure of bare Ag(001) with the residual presence of subsurface Fe aggregates.Comment: 4 pages, 3 figure

Hostels : greenhouses or warehouses? : an ethnographic and theoretical study of the origins, development and purposes of approved premises

This thesis explores the development of hostels / approved premises and considers the existence of an 'unexplored' past that may help cast light on their current purposes. Drawing on historical and theoretical domains it constructs a hinterland from which to undertake critical exploration of their current practices and possible futures. A staged ethnographic study of two hostels is offered, with a four year gap in between to allow consideration as to whether hostels are changing and whether wider policy shifts impacting on probation more generally, can be seen to be shaping hostels' possible future(s). Observations, interviews, engagement in both formal and informal meetings with staff, residents and managers have been used to develop a view of hostels from the underside of practice. Critical theorising and exploration of hostels' past has been located against both the wider social and political shifts that may be seen to have impacted on the rehabilitative and re-integrative role of the hostel, and the emerging themes emanating from the ethnographic work. Key points of discussion include: an argument for a longer history of hostels than is currently suggested, an exploration of the relationship between hostels and the wider probation service and criminal justice system, the centrality of re-integration to rehabilitation and the impact of new punitiveness on hostels' changing role and function at the start of the 21st century. It is argued that a retreat from integration of offenders into society and a devaluing of their social agency and moral worth is now at risk of becoming accepted as part of hostels' 'new' public protection role. Consideration is given to how staff and residents may be experiencing the 'risk driven' changes that are taking place and what wider implications this works findings may have for policy, practice and rehabilitative theory. An alternative penology is offered that both takes account of hostels past and acknowledges their changed clientele.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Asaia, a versatile acetic acid bacterial symbiont, capable of cross-colonizing insects of phylogenetically-distant genera and orders

Bacterial symbionts of insects have been proposed for blocking transmission of vector-borne pathogens. However, in many vector models the ecology of symbionts and their capability of cross-colonizing different hosts, an important feature in the symbiotic control approach, is poorly known. Here we show that the acetic acid bacterium Asaia, previously found in the malaria mosquito vector Anopheles stephensi, is also present in and capable of cross-colonizing other sugar-feeding insects of phylogenetically distant genera and orders. PCR, real-time PCR and in situ-hybridization experiments showed Asaia in the body of the mosquito Aedes aegypti and the leafhopper Scaphoideus titanus, vectors of human viruses and a grapevine phytoplasma, respectively. Cross colonization patterns of the body of Ae. aegypti, An. stephensi and S. titanus have been documented with Asaia strains isolated from An. stephensi or Ae. aegypti, and labelled with plasmid- or chromosome-encoded fluorescent proteins (Gfp and DsRed, respectively). Fluorescence and confocal microscopy showed that Asaia, administered with the sugar meal, efficiently colonized guts, male and female reproductive systems and the salivary glands. The ability in cross-colonizing insects of phylogenetically distant orders indicates that Asaia adopts body invasion mechanisms independent from the host biological characteristics. This versatility is an important property for the development of symbiont-based therapies of different vector-borne diseases