Visual search in spatial neglect studied with a preview paradigm.

Impaired visual search is a hallmark of spatial neglect. When searching for an unique feature (e.g., color) neglect patients often show only slight visual field asymmetries. In contrast, when the target is defined by a combination of features (e.g., color and form) they exhibit a severe deficit of contralesional search. This finding suggests a selective impairment of the serial deployment of spatial attention. Here, we examined this deficit with a preview paradigm. Neglect patients searched for a target defined by the conjunction of shape and color, presented together with varying numbers of distracters. The presentation time was varied such that on some trials participants previewed the target together with same-shape/different-color distracters, for 300 or 600 ms prior to the appearance of additional different-shape/same-color distracters. On the remaining trials the target and all distracters were shown simultaneously. Healthy participants exhibited a serial search strategy only when all items were presented simultaneously, whereas in both preview conditions a pop-out effect was observed. Neglect patients showed a similar pattern when the target was presented in the right hemifield. In contrast, when searching for a target in the left hemifield they showed serial search in the no-preview condition, as well as with a preview of 300 ms, and partly even at 600 ms. A control experiment suggested that the failure to fully benefit from item preview was probably independent of accurate perception of time. Our results, when viewed in the context of existing literature, lead us to conclude that the visual search deficit in neglect reflects two additive factors: a biased representation of attentional priority in favor of ipsilesional information and exaggerated capture of attention by ipsilesional abrupt onsets.

Hierarchical conditional random fields for parts based models matching

A parts based model is a parametrization of an object class using a collection of landmarks following the object structure. The matching of parts based models is one of the problems where pairwise Conditional Random Fields have been successfully applied. The main reason of their effectiveness is tractable inference and learning due to the simplicity of involved graphs, usually trees. However, these models do not consider possible patterns of statistics among sets of landmarks, and thus they sufffer from using too myopic information. To overcome this limitation, we propoese a novel structure based on a hierarchical Conditional Random Fields, which we explain in the first part of this memory. We build a hierarchy of combinations of landmarks, where matching is performed taking into account the whole hierarchy. To preserve tractable inference we effectively sample the label set. We test our method on facial feature selection and human pose estimation on two challenging datasets: Buffy and MultiPIE. In the second part of this memory, we present a novel approach to multiple kernel combination that relies on stacked classification. This method can be used to evaluate the landmarks of the parts-based model approach. Our method is based on combining responses of a set of independent classifiers for each individual kernel. Unlike earlier approaches that linearly combine kernel responses, our approach uses them as inputs to another set of classifiers. We will show that we outperform state-of-the-art methods on most of the standard benchmark datasets.

Control of optical fields and single photon emitters by advanced nanoantenna structures

The control of optical fields on the nanometre scale is becoming an increasingly important tool in many fields, ranging from channelling light delivery in photovoltaics and light emitting diodes to increasing the sensitivity of chemical sensors to single molecule levels. The ability to design and manipulate light fields with specific frequency and space characteristics is explored in this project. We present an alternative realisation of Extraordinary Optical Transmission (EOT) that requires only a single aperture and a coupled waveguide. We show how this waveguide-resonant EOT improves the transmissivity of single apertures. An important technique in imaging is Near-Field Scanning Optical Microscopy (NSOM); we show how waveguide-resonant EOT and the novel probe design assist in improving the efficiency of NSOM probes by two orders of magnitude, and allow the imaging of single molecules with an optical resolution of as good as 50 nm. We show how optical antennas are fabricated into the apex of sharp tips and can be used in a near-field configuration.

Imatges i paraules : poesia visual catalana a la primera avantguarda

Es pregunta pels trets característics de la poesia visual de la primera avantguarda, els que resten fidels a la inspiració europea i els que sorgeixen com a resposta particular mediatitzada per unes determinades condicions socioculturals, i de quina manera aquests trets prenen cos en la producció poètica.

The role of urea in the oviposition behaviour of Japanese encephalitis vectors in rice fields of South India

The effect of urea on the oviposition behaviour of culicine vectors of Japanese encephalitis was studied in rice fields. Gravid females had a strong preference for oviposition in urea treated areas in rice fields, while no such preference was exhibited in untreated areas. The egg laying declined in the area where urea treated water surface had a mechanical barrier, which allowed volatile fractions to escape, but prevented contact with the water. Urea was shown to act as an oviposition attractant/stimulant for Culex tritaeniorhynchus, but its role was not clear for Cx. vishnui, as the number of egg rafts obtained for the latter species was low.

Librería visual adaptativa para integrar servicios de un touroperador en plataformas web

La innovación abierta (Open innovation) se presenta como una oportunidad para combinar los conocimientos internos de la venta de servicios vacacionales combinado con los conocimientos de tecnologías innovadoras. El desarrollo de una librería visual adaptativa pretende ser una solución a la tendencia de cambio actual y a las dificultades de integración de los servicios vacacionales. En el transcurso del proyecto se desarrolla un marco de trabajo que permita cumplir los objetivos marcados para la librería.

Gestió de factures electròniques amb .NET (Visual Studio Tools for Office)

Creació d¿un software de gestió de factures electròniques desenvolupat en aquesta plataforma tecnològica, amb indicació expressa d¿utilització de les eines VSTO (Visual Studio Tools for Office) en la seva última versió.

Visual Management Vinotec V.1.0

El projecte amb nom clau Visual Management Vinotec neix de la necessitat d'administrar i gestionar el catàleg de productes d'una empresa que es dedica a la distribució de licors espirituosos (conyacs i whiskies), generesos (Jerez), vins i caves. Es tracta d'una eina web destinada als professionals del món dels destil·lats i del món vinícola.

Calculation of correction factors for ionization chamber measurements with small fields in low-density media.

The quantity of interest for high-energy photon beam therapy recommended by most dosimetric protocols is the absorbed dose to water. Thus, ionization chambers are calibrated in absorbed dose to water, which is the same quantity as what is calculated by most treatment planning systems (TPS). However, when measurements are performed in a low-density medium, the presence of the ionization chamber generates a perturbation at the level of the secondary particle range. Therefore, the measured quantity is close to the absorbed dose to a volume of water equivalent to the chamber volume. This quantity is not equivalent to the dose calculated by a TPS, which is the absorbed dose to an infinitesimally small volume of water. This phenomenon can lead to an overestimation of the absorbed dose measured with an ionization chamber of up to 40% in extreme cases. In this paper, we propose a method to calculate correction factors based on the Monte Carlo simulations. These correction factors are obtained by the ratio of the absorbed dose to water in a low-density medium □D(w,Q,V1)(low) averaged over a scoring volume V₁ for a geometry where V₁ is filled with the low-density medium and the absorbed dose to water □D(w,QV2)(low) averaged over a volume V₂ for a geometry where V₂ is filled with water. In the Monte Carlo simulations, □D(w,QV2)(low) is obtained by replacing the volume of the ionization chamber by an equivalent volume of water, according to the definition of the absorbed dose to water. The method is validated in two different configurations which allowed us to study the behavior of this correction factor as a function of depth in phantom, photon beam energy, phantom density and field size.

Traceroute Visual : Geolocalización IP

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