Search results for "Contraste"
showing 10 items of 20 documents
Influence of contrast polarity on the accommodative response☆
2018
espanolObjetivo Evaluar los cambios de la respuesta acomodativa del ojo al leer un texto en diferentes condiciones de polaridad de contraste: letras negras sobre fondo blanco (condicion BoW) y letras blancas sobre fondo negro (condicion WoB). Metodos En este estudio experimental participaron dieciocho sujetos de edades comprendidas entre 21 y 41 anos. Se obtuvo objetivamente la respuesta acomodativa (AR) del ojo al leer un texto con polaridad de contraste BoW o WoB con un sistema de optica adaptativa que corregia todas las aberraciones salvo las propias del sujeto. Se estudiaron dos tamanos de letra diferentes (condiciones de agudeza visual), mostrados en una micropantalla. Se midio la AR d…
Diseño de una nueva prueba para medir la función de sensibilidad al contraste con iPad
2015
[EN] Purpose: To introduce a new application (ClinicCSF) to measure Contrast Sensitivity Function (CSF) with tablet devices, and to compare it against the Functional Acuity Contrast Test (FACT). Methods: A total of 42 subjects were arranged in two groups of 21 individuals. Different versions of the ClinicCSF (.v1 and .v2) were used to measure the CSF of each group with the same iPad and the results were compared with those measured with the FACT. The agreements between ClinicCSF and FACT for spatial frequencies of 3, 6, 12 and 18 cycles per degree (cpd) were represented by Bland---Altman plots. Results: Statistically significant differences in CSF of both groups were found due to the change…
Porphyrines et tétraazamacrocycles dérivés du DOTA : association de deux ligands pour la chélation de métaux d'intérêt en imagerie médicale multimoda…
2012
The goal of my PhD thesis was to synthesize new molecules, which give access to heterobimetallic complexes with interesting properties for multimodal imaging. In this manuscript, several main points have been studied. The first part of this work concerns the synthesis and characterization of ligands. We describe here the synthesis of five new ligands based on the association of one porphyrin and one or several cyclen derivatives. Those ligands are water-soluble. During the synthesis, we have targeted improvements to our work and developed a new synthetic pathway, which allowed us to obtain one ligand incorporating a porphyrin, a cyclen derivative and a free amine function. This function cou…
Problemas en la estimación y en el contraste de los rendimientos anormales a largo plazo: Estado de la cuestión
2002
-Jose.E.Farinos@uv.es -Ana.M.Ibanez@uv.es El paradigma de la eficiencia ha sido puesto en entredicho en las últimas décadas como consecuencia de la obtención de rendimientos anormales, estadística y económicamente significativos, durante amplios periodos de tiempo tras algunas importantes decisiones empresariales. No obstante, los problemas conceptuales y estadísticos que presenta la medición y contrastación de los rendimientos anormales a largo plazo ha supuesto que la evidencia obtenida pase a calificarse como anomalía. Dada la escasa proliferación de este tipo de estudios en nuestro mercado y el desafortunado desarrollo de algunos de los existentes, en este trabajo presentamos estos prob…
Inferencia Estadística (2010/11)
2010
Los contenidos de la materia , tras repasar y consolidar algunas cuestiones del cálculo de probabilidades , especialmente las distribuciones multivariantes y las derivadas de las distribución normal, se centran en los recursos teóricos fundamentales para resolver los dos problemas esenciales de la inferencia estadística: la estimación de parámetros y el contaste de hipótesis
Casting the light on cinema – how luminance and contrast patterns create meaning
2012
The question of meaning creation has always been at the core of cross-disciplinary scholarly research. Considered from the cinematographic perspective, it inevitably evokes correlations with plot and dialogue. However, the conveyance of significance in films does not rely solely on the verbal channel, but also manifests itself in the visual layer, ranging from facial expressions, setting and locations, to directorial editing choices. Elevating the role of the how of film making, this article focuses on the influence of light and contrast patterns on the reading of cinema. In order to highlight their position in film text vocabulary and recognize their relevance in film translations and adap…
I traffici illeciti nel Mediterraneo. Persone, stupefacenti, tabacco
2019
Attraverso la combinazione di ricerca criminologica e giuridico-normativa, e grazie anche alla collaborazione con esperti esterni (studiosi, magistrati, rappresentanti di istituzioni italiane e straniere), la ricerca da cui scaturisce il volume ha indagato le interazioni tra i diversi traffici illeciti e la criminalità organizzata nel bacino del Mediterraneo. In tale area, storicamente cruciale per la mobilità di persone e di beni, l’attenzione si è rivolta in particolare ai fenomeni del traffico e della tratta di persone, del traffico di stupefacenti e del contrabbando di sigarette. I contributi raccolti – unitamente al rapporto criminologico e ai cinque rapporti nazionali accessibili su w…
Implantable collamer lens and femtosecond laser for myopia: comparison using an adaptive optics visual simulator.
2014
Purpose: To compare optical and visual quality of implantable collamer lens (ICL) implantation and femtosecond laser in situ keratomileusis (F-LASIK) for myopia. Methods: The CRX1 adaptive optics visual simulator (Imagine Eyes, Orsay, France) was used to simulate the wavefront aberration pattern after the two surgical procedures for -3-diopter (D) and -6-D myopia. Visual acuity at different contrasts and contrast sensitivities at 10, 20, and 25 cycles/degree (cpd) were measured for 3-mm and 5-mm pupils. The modulation transfer function (MTF) and point spread function (PSF) were calculated for 5-mm pupils. Results: F-LASIK MTF was worse than ICL MTF, which was close to diffraction-limited MT…
ESGAR consensus statement on liver MR imaging and clinical use of liver-specific contrast agents
2016
Objectives: To develop a consensus and provide updated recommendations on liver MR imaging and the clinical use of liver-specific contrast agents. Methods: The European Society of Gastrointestinal and Abdominal Radiology (ESGAR) formed a multinational European panel of experts, selected on the basis of a literature review and their leadership in the field of liver MR imaging. A modified Delphi process was adopted to draft a list of statements. Descriptive and Cronbach’s statistics were used to rate levels of agreement and internal reliability of the consensus. Results: Three Delphi rounds were conducted and 76 statements composed on MR technique (n = 17), clinical application of liver-speci…
Utilidad de la ecografía con contraste intravenoso en la valoración de la recurrencia postquirúrgica de la enfermedad de Crohn
2016
Introducción: La recurrencia postquirúrgica es una situación frecuente en la enfermedad de Crohn (EC). La utilidad de la valoración clínica y analítica para el diagnóstico de recurrencia es limitado y actualmente, la técnica de referencia es la ileocolonoscopia que permite la valoración de la anastomosis ileocólica y/o del intestino proximal a la misma. Mediante el Índice de Rutgeerts se puede determinar la gravedad de la recurrencia que está relacionada con el desarrollo precoz de recurrencia clínica y necesidad de nueva cirugía. No obstante la técnica endoscópica, es una prueba con escasa aceptación por la paciente, no exenta de riesgos y limitaciones como la imposibilidad de franquear la…