1,206 research outputs found

    Crafting positive/negative patterns and nanopillars of polymer brushes by photocatalytic lithography

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    We demonstrate a convenient and versatile approach based on the photocatalytic lithography to obtain micro- and nanostructures of polymer brushes. Micro-patterns of polymer brushes are obtained through two ways: by the selective photocatalytic degradation of an initiator, self-assembled on the surface (\u201cpositive\u201d pattern), or by a \u201cnegative\u201d pattern obtained, first, degrading an alkylsiloxane monolayer and, then, refilling it with the initiator. In both cases, the patterned initiator monolayer is eventually amplified into polymer brushes with a controlled radical polymerization protocol (ARGET ATRP). The approach described here mimics the conventional photolithography but is free from the disadvantages associated to this technique (i.e. highly energetic light sources, polymeric resists and on purpose-made photomasks). Moreover, the ability to generate nanometer-sized pillars of polymer brushes using remote photocatalysis coupled with nanosphere lithography is demonstrated. Highly monodisperse silica particles with spherical shape (diameter 3c600\ua0nm) are assembled on the surface to be patterned and used as a mask for remote photocatalysis. Our results confirm the great potentialities of TiO2-photocatalytic lithography for patterning of polymer brushes

    Don't judge a book by its cover. factitious disorder imposed on children-report on 2 cases

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    Factitious Disorder Imposed on Another (FDIA), also known as Munchausen Syndrome by Proxy (MSbP) is a very serious form of child abuse. The perpetrator, usually the mother, invents symptoms or causes real ones in order to make her child appear sick. Usually this is due to a maladaptive disorder or to an excessive of attention-seeking on her part. We report here two new cases of FDIA. The first one is a 9-year-old boy with a history of convulsive episodes, reduced verbal production, mild psychomotor disorder and urological problems who underwent several invasive procedures and hospitalizations before a diagnosis of FDIA was made. The second is a 12 year-old girl with headache, abdominal pain, lipothymic episodes, seizures and a gait impairment, who was hospitalized in several hospitals before an FDIA was diagnosed

    A knowledge based architecture for the virtual restoration of ancient photos

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    Historical images are essential documents of the recent past. Nevertheless, time and bad preservation corrupt their physical supports. Digitization can be the solution to extend their \u201clives\u201d, and digital techniques can be used to recover lost information. This task is often difficult and time-consuming, if commercial restoration tools are used for the purpose. A new solution is proposed to help non-expert users in restoring their damaged photos. First, we defined a dual taxonomy for the defects in printed and digitized photos. We represented our restoration domain with an ontology and we created some rules to suggest actions to perform in case of some specific events. Classes and properties of the ontology are included into a knowledge base, that grows dynamically with its use. A prototypal tool and a web application version have been implemented as an interface to the database, and to support non-expert users in the restoration process

    Combining Top-down and Bottom-up Visual Saliency for Firearms Localization

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    Object detection is one of the most challenging issues for computer vision researchers. The analysis of the human visual attention mechanisms can help automatic inspection systems, in order to discard useless information and improving performances and efficiency. In this paper we proposed our attention based method to estimate firearms position in images of people holding firearms. Both top-down and bottom-up mechanisms are involved in our system. The bottom-up analysis is based on a state-of-the-art approach. The top-down analysis is based on the construction of a probabilistic model of the firearms position with respect to the people\u2019s face position. This model has been created by analyzing information from of a public available database of movie frames representing actors holding firearms

    Hydrodynamical Models of Superfluid Turbulence

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    This review paper puts together some of our results concerning the application of non equilibrium Thermodynamics to superfluid liquid helium. Two of the most important situations of this quantum fluid are rotating superfluid and superfluid turbulence, both characterized by the presence of quantized vortices (vortex lines whose core is about 1 Angstrom and the quantum of circulation is h/mh/m, hh being the Plank's constant and mm the mass of helium atom). In the first part of the work a non-standard model of superfluid helium, which considers heat flux as independent variable, is briefly recalled, and compared with the well known two-fluid model, in absence of vortices, proposed by Tisza and Landau more than half a century ago. The model is generalized taking into account the presence of vortices in different cases of physical interest: rotating superfluids, counterflow superfluid turbulence (a particular situation in which no mass flux but only heat flux is present) and combined situations of counterflow and rotation. Since vortices are not fixed when all the hydrodynamical fields change, an additional scalar quantity, the averaged vortex line density per unit volume LL, {\it line density} for short, is introduced in the model as a new field variable and an evolution equation is written for it, both in linear and in nonlinear regimes, via Extended Thermodynamics. Finally, to encompass more general situations, the model is further extended considering the flux of vortex line density as an independent new variable. In all these models the propagation of harmonic waves is studied, motivated by the fact that vortex lines density is experimentally detected via the attenuation of second sound. A new kind of waves, vortex density waves, is also dealt with

    A dataset of annotated omnidirectional videos for distancing applications

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    Omnidirectional (or 360â—¦ ) cameras are acquisition devices that, in the next few years, could have a big impact on video surveillance applications, research, and industry, as they can record a spherical view of a whole environment from every perspective. This paper presents two new contributions to the research community: the CVIP360 dataset, an annotated dataset of 360â—¦ videos for distancing applications, and a new method to estimate the distances of objects in a scene from a single 360â—¦ image. The CVIP360 dataset includes 16 videos acquired outdoors and indoors, annotated by adding information about the pedestrians in the scene (bounding boxes) and the distances to the camera of some points in the 3D world by using markers at fixed and known intervals. The proposed distance estimation algorithm is based on geometry facts regarding the acquisition process of the omnidirectional device, and is uncalibrated in practice: the only required parameter is the camera height. The proposed algorithm was tested on the CVIP360 dataset, and empirical results demonstrate that the estimation error is negligible for distancing applications

    Observations on the reproductive cycle, age and growth of the salema, <em>Sarpa salpa</em> (Osteichthyes: Sparidae) along the western central coast of Italy

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    La maduración sexual y crecimiento de Sarpa salpa (Linnaeus, 1758) en las costas del Mediterráneo italiano (Italia central) fueron estudiadas a partir de la recolecta de ejemplares muertos accidentalmente (n = 105) como consecuencia de las explosiones submarinas acaecidas durante la construcción del puerto de Civitavecchia en 1999, así como de ejemplares recolectados mediante redes de arrastre (n = 339). Esta especie se caracteriza por un hermafroditismo protándrico, ocurriendo el proceso de cambio sexual entre los 24 y 31 cm TL, los cuales corresponden a un amplio rango de edades (3-7 años). La talla de maduración (L50) fue de 19,5 cm, siendo la casi la totalidad de los individuos eran de sexo masculino. Se observaron dos períodos diferentes de reproducción: uno en primavera, de marzo a mayo y otro en otoño, de finales de septiembre a noviembre. Se observó, durante el primer año, un crecimiento compensatorio ocurrido entre los individuos nacidos en los dos períodos. Se identificó en los otolitos un modelo anual y regular de deposición de anillos. Se observó el depósito de un anillo translúcido durante los meses invernales, mientras que otro opaco se formó durante los meses de verano. Las composición por edades y tallas retrocalculadas se utilizaron para estimar los parámetros de la ecuación de crecimiento de Von Bertalanffy, es decir: L∞ = 37,27 cm, K = 0,27 año-1 y t0 = -0,53 año. S. salpa demostró un crecimiento isométrico (b = 3,04; P = 0,84; t = 0,19)

    SMAP Data Assimilation at the GMAO

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    The NASA Soil Moisture Active Passive (SMAP) mission has been providing L-band (1.4 GHz) passive microwave brightness temperature (Tb) observations since April 2015. These observations are sensitive to surface(0-5 cm) soil moisture. Several of the key applications targeted by SMAP, however, require knowledge of deeper-layer, root zone (0-100 cm) soil moisture, which is not directly measured by SMAP. The NASA Global Modeling and Assimilation Office (GMAO) contributes to SMAP by providing Level 4 data, including the Level 4 Surface and Root Zone Soil Moisture(L4_SM) product, which is based on the assimilation of SMAP Tb observations in the ensemble-based NASA GEOS-5 land surface data assimilation system. The L4_SM product offers global data every three hours at 9 km resolution, thereby interpolating and extrapolating the coarser- scale (40 km) SMAP observations in time and in space (both horizontally and vertically). Since October 31, 2015, beta-version L4_SM data have been available to the public from the National Snow and Ice Data Center for the period March 31, 2015, to near present, with a mean latency of approx. 2.5 days
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