Estudi i implementació de tècniques de reconeixement facial

Estudi i implementació de les tècniques de reconeixement facial més conegudes: eigenfaces, fisherfaces i ASM. El resultat és una aplicació implementada en Matalab que permet realitzar el reconeixement de persones en temps real.

Psychometric characteristics of the Spanish version of instruments to measure neck pain disability

Background: The NDI, COM and NPQ are evaluation instruments for disability due to NP. There was no Spanish version of NDI or COM for which psychometric characteristics were known. The objectives of this study were to translate and culturally adapt the Spanish version of the Neck Disability Index Questionnaire (NDI), and the Core Outcome Measure (COM), to validate its use in Spanish speaking patients with non-specific neck pain (NP), and to compare their psychometric characteristics with those of the Spanish version of the Northwick Pain Questionnaire (NPQ).Methods: Translation/re-translation of the English versions of the NDI and the COM was done blindly and independently by a multidisciplinary team. The study was done in 9 primary care Centers and 12 specialty services from 9 regions in Spain, with 221 acute, subacute and chronic patients who visited their physician for NP: 54 in the pilot phase and 167 in the validation phase. Neck pain (VAS), referred pain (VAS), disability (NDI, COM and NPQ), catastrophizing (CSQ) and quality of life (SF-12) were measured on their first visit and 14 days later. Patients' self-assessment was used as the external criterion for pain and disability. In the pilot phase, patients' understanding of each item in the NDI and COM was assessed, and on day 1 test-retest reliability was estimated by giving a second NDI and COM in which the name of the questionnaires and the order of the items had been changed.Results: Comprehensibility of NDI and COM were good. Minutes needed to fill out the questionnaires [median, (P25, P75)]: NDI. 4 (2.2, 10.0), COM: 2.1 (1.0, 4.9). Reliability: [ICC, (95%CI)]: NDI: 0.88 (0.80, 0.93). COM: 0.85 (0.75,0.91). Sensitivity to change: Effect size for patients having worsened, not changed and improved between days 1 and 15, according to the external criterion for disability: NDI: -0.24, 0.15, 0.66; NPQ: -0.14, 0.06, 0.67; COM: 0.05, 0.19, 0.92. Validity: Results of NDI, NPQ and COM were consistent with the external criterion for disability, whereas only those from NDI were consistent with the one for pain. Correlations with VAS, CSQ and SF-12 were similar for NDI and NPQ (absolute values between 0.36 and 0.50 on day 1, between 0.38 and 0.70 on day 15), and slightly lower for COM (between 0.36 and 0.48 on day 1, and between 0.33 and 0.61 on day 15). Correlation between NDI and NPQ: r = 0.84 on day 1, r = 0.91 on day 15. Correlation between COM and NPQ: r = 0.63 on day 1, r = 0.71 on day 15.Conclusion: Although most psychometric characteristics of NDI, NPQ and COM are similar, those from the latter one are worse and its use may lead to patients' evolution seeming more positive than it actually is. NDI seems to be the best instrument for measuring NP-related disability, since its results are the most consistent with patient's assessment of their own clinical status and evolution. It takes two more minutes to answer the NDI than to answer the COM, but it can be reliably filled out by the patient without assistance.

Fine speckle contrast in InGaAs/InP systems: Influence of layer thickness, missmatch, and growing temperature

This work is focused on the study of the fine speckle contrast present in planar view observations of matched and mismatched InGaAs layers grown by molecular beam epitaxy on InP substrates. Our results provide experimental evidence of the evolution of this fine structure with the mismatch, layer thickness, and growth temperature. The correlation of the influence of all these parameters on the appearance of the contrast modulation points to the development of the fine structure during the growth. Moreover, as growth proceeds, this structure shows a dynamic behavior which depends on the intrinsic layer substrate stress.

Origin of the neutron skin thickness of 208Pb in nuclear mean-field models

We study whether the neutron skin thickness Δrnp of 208Pb originates from the bulk or from the surface of the nucleon density distributions, according to the mean-field models of nuclear structure, and find that it depends on the stiffness of the nuclear symmetry energy. The bulk contribution to Δrnp arises from an extended sharp radius of neutrons, whereas the surface contribution arises from different widths of the neutron and proton surfaces. Nuclear models where the symmetry energy is stiff, as typical of relativistic models, predict a bulk contribution in Δrnp of 208Pb about twice as large as the surface contribution. In contrast, models with a soft symmetry energy like common nonrelativistic models predict that Δrnp of 208Pb is divided similarly into bulk and surface parts. Indeed, if the symmetry energy is supersoft, the surface contribution becomes dominant. We note that the linear correlation of Δrnp of 208Pb with the density derivative of the nuclear symmetry energy arises from the bulk part of Δrnp. We also note that most models predict a mixed-type (between halo and skin) neutron distribution for 208Pb. Although the halo-type limit is actually found in the models with a supersoft symmetry energy, the skin-type limit is not supported by any mean-field model. Finally, we compute parity-violating electron scattering in the conditions of the 208Pb parity radius experiment (PREX) and obtain a pocket formula for the parity-violating asymmetry in terms of the parameters that characterize the shape of the 208Pb nucleon densities.

Computer-aided procedure for optimization of layer thickness uniformity in thermal evaporation physical vapor deposition chambers for lens coating

A computer-aided method to improve the thickness uniformity attainable when coating multiple substrates inside a thermal evaporation physical vapor deposition unit is presented. The study is developed for the classical spherical (dome-shaped) calotte and also for a plane sector reversible holder setup. This second arrangement is very useful for coating both sides of the substrate, such as antireflection multilayers on lenses. The design of static correcting shutters for both kinds of configurations is also discussed. Some results of using the method are presented as an illustration.

Automatic Prediction of Facial Trait Judgments: Appearance vs. Structural Models

Evaluating other individuals with respect to personality characteristics plays a crucial role in human relations and it is the focus of attention for research in diverse fields such as psychology and interactive computer systems. In psychology, face perception has been recognized as a key component of this evaluation system. Multiple studies suggest that observers use face information to infer personality characteristics. Interactive computer systems are trying to take advantage of these findings and apply them to increase the natural aspect of interaction and to improve the performance of interactive computer systems. Here, we experimentally test whether the automatic prediction of facial trait judgments (e.g. dominance) can be made by using the full appearance information of the face and whether a reduced representation of its structure is sufficient. We evaluate two separate approaches: a holistic representation model using the facial appearance information and a structural model constructed from the relations among facial salient points. State of the art machine learning methods are applied to a) derive a facial trait judgment model from training data and b) predict a facial trait value for any face. Furthermore, we address the issue of whether there are specific structural relations among facial points that predict perception of facial traits. Experimental results over a set of labeled data (9 different trait evaluations) and classification rules (4 rules) suggest that a) prediction of perception of facial traits is learnable by both holistic and structural approaches; b) the most reliable prediction of facial trait judgments is obtained by certain type of holistic descriptions of the face appearance; and c) for some traits such as attractiveness and extroversion, there are relationships between specific structural features and social perceptions.

Growth and melting of the nematic phase: sample thickness dependence of the Mullins-Sekerka instability

In this article we report our systematic studies of the dependence on the sample thickness of the onset parameters of the instability of the nematic-isotropic interface during directional growth and melting, in homeotropic or planar anchoring.

Tratamiento de las úlceras neuropáticas con descargas

Las úlceras neuropáticas es una de las complicaciones que con más frecuencia presenta el paciente diabético. El principal objetivo en el tratamiento de las úlceras neuropáticas es potenciar los mecanismos fisiológicos de cicatrización, para ello es necesario actuar sobre los factores que retrasan este proceso. Uno de los principales factores que actúan como desencadenante y agravante en la aparición de una úlcera neuropática es el aumento de la presión plantar, condicionada por una alteración en el apoyo ya sea por causa estructural o biomecánica, al mismo tiempo esta hiperpresión continuada actúa retrasando los mecanismos de cicatrización. El método que ha demostrado mayor efectividad es el tratamiento de las úlceras neuropáticas plantares es el tratamiento con descargas. Vamos a exponer en este trabajo las diferentes técnicas de descarga que se pueden utilizar para tratar una ulcera neuropática a nivel ambulatorio.

Alternativas del moldeado en alteraciones del antepié

El molde en carga controlada sobre espumas de poliuretano es la técnica de moldeado que mejores resultados nos está ofreciendo en la actualidad, ya que permite la obtención del molde en posición más fisiológica, con el paciente en bipedestación en ángulo y base de marcha, permitiendo la distensión de tejidos blandos evitando riesgo de hipercorrecciones, además de poder realizarlo sobre un banco de marcha informatizado permitiendo visualizar a través del monitor la huella plantar simultáneamente a la confección de dicho molde. La importancia de la realización de tratamientos ortopodológicos individualizados o personalizados en función de cada patología, nos ha conducido a realizar también el molde de forma personalizada en función del diagnóstico obtenido. Para ello hemos descrito una técnica modificada del molde en carga controlada aplicando el sistema diagnóstico "Functional block test" en su confección. El sistema diagnóstico "block test", descrito por el Doctor Whitney de la Temple University de Philadelphia, es de gran utilidad en laexploración clínica diaria. Se basa en el diseño de diferentes cuñas o elementos compensadores de cada patología existente en el pie en cada uno de los tres planos corporales. La aplicación del elemento correspondiente a la patología situado bajo el pie con el paciente en blpedestación conduce a la articulación subastragalina hacia su neutralidad y por tanto ayuda a confirmar el diagnóstico obtenido. La aplicación de dichos elementos en la confección del molde en carga permite un mejor control de la posición neutra del pie y un óptimo reflejo de dicha patología en el molde confeccionado, permitiendo posteriormente su correcta compensación en el tratamiento ortopodológico..

Efecto de las ortesis plantares en los cambios de presión del antepié

El uso de soportes plantares ante la presenda de sobrecargas metatarsales se ha mostrado como un tratamiento muy efectivo ante la sintomatología dolorosa asociada a esta problemática del antepié, secundariaprincipalmente a problemas biomecánicos. Este estudio trata de demostrar la justificación del efecto de estos tratamientos, mediante el análisis de los cambios de presión que suceden en el antepié con el uso de un soporte plantar prefabricado y otro confeccionado a medida. Los resultados ofrecen cambios significativos con el uso de los tratamientos ortopodológicos, principalmente con los individualizados, es decir, los confeccionados a medida sobre un molde del pie.

Tratamiento combinado en un pie cavo varo bilateral

Paciente femenina de 34 años de edad, acude a la consulta con dolor agudo selectivo en la zona plantar del antepie a nivel de las cabezas del 1er y 2º metatarsiano. Realizada la anamnesis descartamos cualquier posibilidad de traumatismo o neuralgia. A lo largo de este trabajo expondremos las características principales de la paciente observadas durante la exploración tanto en estática como en dinámica, diseño del plan de tratamiento con los objetivos que pretendemos alcanzar, metodología de aplicación y conclusiones.