309 research outputs found

    Neural Networks, Ordered Probit Models and Multiple Discriminants. Evaluating Risk Rating Forecasts of Local Governments in Mexico.

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    Credit risk ratings have become an important input in the process of improving transparency of public finances in local governments and also in the evaluation of credit quality of state and municipal governments in Mexico. Although rating agencies have recently been subjected to heavy criticism, credit ratings are indicators still widely used as a benchmark by analysts, regulators and banks monitoring financial performance of local governments in stable and volatile periods. In this work we compare and evaluate the performance of three forecasting methods frequently used in the literature estimating credit ratings: Artificial Neural Networks (ANN), Ordered Probit models (OP) and Multiple Discriminant Analysis (MDA). We have also compared the performance of the three methods with two models, the first one being an extended model of 34 financial predictors and a second model restricted to only six factors, accounting for more than 80% of the data variability. Although ANN provides better performance within the training sample, OP and MDA are better choices for classifications in the testing sample respectively.Credit Risk Ratings, Ordered Probit Models, Artificial Neural Networks, Discriminant Analysis, Principal Components, Local Governments, Public Finance, Emerging Markets

    El estilo de aprendizaje y su relación con la educación entre pares

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    The objectives of this work are: to diagnose the Learning Style (LS) of the students of compulsory secondary education (ESO), to know their perception of the peer tutoring and to analyze the relationship between the students’ LS and peer tutoring. The empirical study was conducted with students from all courses of the ESO in 6 school centers in Spain. Data collection was performed using two instruments: the CHAEA and a questionnaire designed by the team of research on peer tutor. In the results it is found that the students´LS is predominantly reflective, students consider the figure of the peer tutor right for learning, and the largest significant differences were found between the active Style and peer tutor.Los objetivos de esta investigación son: diagnosticar el Estilo de Aprendizaje (EA) del alumnadode la Educación Secundaria Obligatoria (ESO), conocer la percepción de este alumnado sobre la figura del compañero tutor, y analizar la relación entre el EA del alumnado y la figura del compañero tutor. Se plantean como hipótesis que no existen diferencias entre los Estilos de Aprendizaje del alumnado y las características del compañero tutor. El estudio empírico se llevó a cabo con estudiantes de todos los cursos de la ESO en 6 Centros en España. La recogida de datos se realizó con dos instrumentos: el CHAEA y un cuestionario diseñado por el propio equipo de investigación sobre compañero tutor. En los resultados se comprueba que el EA del alumnado es predominantemente reflexivo, que los alumnos consideran la figura del compañero tutor adecuada para su aprendizaje, y las mayores diferencias significativas se encuentran entre el Estilo activo y el compañero tutor

    Comparative study between nail retraining with gauze bandaging and the nail remodeling with acrylics as a conservative treatment for stage I and IIa onychocryptosis

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    Objective: Onychocryptosis is one of the most prevalent onychopathies, being a frequent reason for consultation in podiatric clinical practice. Conservative treatments are the first therapeutic choice, with nail remodeling using clotrimazole gel emerging as an alternative, although its medium-term effectiveness is unknown. The objective of this study was therefore to compare the efficacy of the technique of nail retraining using gauze bandaging with that of nail remodeling for the conservative treatment of stage I and IIA onychocryptosis. Methods: An analytical, randomized clinical trial study was performed following a longitudinal and prospective design. A sample was selected of 20 subjects presenting stage I and IIA onychocryptosis. Of these, 10 cases formed the group of nail retraining using gauze bandaging, and the other 10 the nail remodeling group. The presence of recurrence in a 3-month period was evaluated. Results: Before the intervention, the patients in the retraining group presented pain of 6.7 ± 1.9 vs. 6.8 ± 1.6 in the remodeling group, with no significant difference between the two (p = 0.900). After the 3-month follow-up period, seven of the retraining group patients presented recurrence of onychocryptosis vs. only one in the remodeling group. Conclusion: The technique of nail remodeling has a lower recurrence rate than that of nail retraining with gauze bandaging, with the pain, inflammation, and infection reported being less, and with greater patient satisfactio

    Estudio de los beneficios obtenidos en fuerza explosiva y flexibilidad tras una intervención de un programa de K-Stretch.

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    Objetivos. Analizar si existe relación entre el trabajo de estiramiento miofascial de K-Stretch y los protocolos de fuerza explosiva tras una intervención de 5 sesiones. Además valorar los beneficios a nivel de flexibilidad isquiosural y de dorsiflexión del tobillo. Material y métodos. Se trata de un estudio prospectivo y cuasi experimental que se ha realizado a 16 estudiantes del Grado Universitario de Ciencias de la Actividad y el Deporte, formando parte 8 sujetos del grupo experimental, realizaron cinco sesiones de K-Stretch® Postural (1 sesión por semana) y los 8 restantes del grupo control que continuaron con su actividad física y entrenamiento habitual. En los dos grupos se realizó una valoración inicial y una final, en el grupo experimental al finalizar las cinco sesiones y en el grupo control transcurridas 5 semanas. Resultados. El estudio muestra que los grupos son homogéneos en cuanto a los datos sociodemográficos, sin encontrar diferencias entre ellos. Se observan ligeros cambios del grupo experimental aunque no son significativos en los protocolos de salto vertical (SJ y CMJ), mientras que en los protocolos de salto horizontal no se aprecian mejoras. En el grupo experimental existe una mejora significativa tanto en dorsiflexión del pie como en la flexibilidad isquiosural, mientras que en el grupo control no se aprecian. Conclusiones. Un programa de cinco sesiones de K-Stretch® Postural mejora significativamente la dorsiflexión del pie y la flexibilidad isquiosural. Además, produce cambios que son casi-significativos en los protocolos de salto vertical

    USEQ: A Short Questionnaire for Satisfaction Evaluation of Virtual Rehabilitation Systems

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    [EN] New emerging technologies have proven their efficacy in aiding people in their rehabilitation. The tests that are usually used to evaluate usability (in general) or user satisfaction (in particular) of this technology are not specifically focused on virtual rehabilitation and patients. The objective of this contribution is to present and evaluate the USEQ (User Satisfaction Evaluation Questionnaire). The USEQ is a questionnaire that is designed to properly evaluate the satisfaction of the user (which constitutes part of usability) in virtual rehabilitation systems. Forty patients with balance disorders completed the USEQ after their first session with ABAR (Active Balance Rehabilitation), which is a virtual rehabilitation system that is designed for the rehabilitation of balance disorders. Internal consistency analysis and exploratory factor analysis were carried out to identify the factor structure of the USEQ. The six items of USEQ were significantly associated with each other, and the Cronbach alpha coefficient for the questionnaire was 0.716. In an analysis of the principal components, a one-factor solution was considered to be appropriate. The findings of the study suggest that the USEQ is a reliable questionnaire with adequate internal consistency. With regard to patient perception, the patients found the USEQ to be an easy-to-understand questionnaire with a convenient number of questions.Gil-Gómez, J.; Manzano-Hernández, P.; Albiol-Perez, S.; Aula-Valero, C.; Gil Gómez, H.; Lozano Quilis, JA. (2017). USEQ: A Short Questionnaire for Satisfaction Evaluation of Virtual Rehabilitation Systems. Sensors. 17(7):1-12. https://doi.org/10.3390/s17071589S112177BEVAN, N. (2001). International standards for HCI and usability. International Journal of Human-Computer Studies, 55(4), 533-552. doi:10.1006/ijhc.2001.0483Abran, A., Khelifi, A., Suryn, W., & Seffah, A. (2003). 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    Estados sincronizados en la dinámica de circuitos genéticos oscilatorios.

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    Los circuitos genéticos oscilatorios son un componente fundamental de la biología de los seres vivos. Estos circuitos están presentes en la fisiología de los todos los seres vivos a través de los circuitos circadianos y en muchos otros procesos de regulación, formación de patrones, etc (ver por ejemplo: Towards a physical understanding of developmental patterning, J. Negrete Jr, A. C. Oates, Nature Reviews Genetics 2021). El objetivo principal de este trabajo es analizar circuitos genéticos que presentan comportamientos oscilatorios basados en el retardo de las respuestas y los mecanismos de sincronización entre células aplicado a un modelo del reloj de segmentación en el proceso de somitogénesis. El estudio la dinámica del sistema ha revelado que los osciladores celulares experimentan una bifurcación de Hopf mediada por el retardo y que, al introducir el acoplo mediado por un segundo retardo intercelular, se observan ventanas de sincronización global o asincronía en función del valor que toma dicho retardo.<br /

    La participación de las mujeres en el desarrollo rural y el bienestar social

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    Women are frequently situated at a risky situation at the rural social environment. Social agents aware of this situation, have to design specific programs to them in order to improve her development and participation. They have to affront not only the economical decadency of their communities but the native culture resistance to social innovation and traditional gender roles change. But in our globalize world, welfare is not possible without taking into account personal wellbeing and human and social capital importance. This article deeps into these topics and suggests possible intervention strategies.La mujer en el entorno rural se encuentra en una situación de vulnerabilidad que obliga a los agentes sociales a la articulación de medidas específicas de desarrollo y participación. Al hecho de encontrarse en un enclave económicamente desprotegido se suele sumar una cultura compartida reticente al cambio y a la innovación en los roles de género. Pero el bienestar social y el desarrollo comunitario no son posibles en nuestro entorno globalizado sin contar con el bienestar individual y la importancia de su capital humano y social. El artículo reflexiona sobre estos temas y aporta posibles estrategias de intervención. 

    Multi-Sensor Feature Extraction and Data Fusion Using ANFIS and 2D Wavelet Transform in Structural Health Monitoring

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    In this chapter, a novel feature extraction and data fusion approach for structural damage detection and localisation is presented. This approach combines adaptive network-based fuzzy inference systems (ANFIS) and two-dimensional wavelet transform (2D-WT) technologies. Simultaneous multi-sensor feature extraction and data fusion based on 2D-WT is carried out by forming a 2D multivariate signal, which is used to analyse the structure vibration response by measuring all sensors jointly. Energy values obtained from two-level db3 wavelet decomposition are arranged in a so-called energy percentage matrix (EPM), which is taken as an input for the ANFIS. The system is further trained by defining its output as the structural condition represented by a condition index. A set of output index patterns are defined depending on the level of damage assessment performed. The proposed method was tested through experiments using a cantilever beam structure. The testing results showed that the method is successful in detecting and localising damage by vibration analysis in structural health monitoring

    Implementing Horizon Scanning as a tool for the strategic development of regulatory guidelines for nanotechnology-enabled health products

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    Strategic regulatory development is essential to ensure that new innovations in nanotechnology-enabled health products (NHPs) successfully reach the market and benefit patients. Currently, the lack of specific regulatory guidelines for NHPs is considered one of the primary causes of the so-called “valley of death” in these products, impacting both current and future advancements. In this study, we have implemented a methodology to anticipate key trends in NHP development and compare them with the current regulatory landscape applicable to NHPs. This methodology relies on Horizon Scanning, a tool commonly used by policymakers to foresee future needs and proactively shape a regulatory framework tailored to those needs. Through the application of this methodology, different trends in NHP have been identified, notably NHPs for drug delivery and dental applications. Furthermore, the most disruptive elements involve NHPs that are multicomposite and multifunctional, harnessing nano-scale properties to combine therapeutic and diagnostic purposes within a single product. When compared with the regulatory landscape, current regulations are gradually adapting to accommodate emerging trends, with specific guidelines being developed. However, for the most disruptive elements, multicomposite and multifunctional NHPs, their novelty still poses significant regulatory challenges, requiring a strategic development of guidelines by regulatory agencies to ensure their safe and effective integration into healthcare practices. This study underscores the importance of proactive regulatory planning to bridge the gap between NHP innovation and market implementation

    Classification system for nanotechnology-enabled health products with both scientific and regulatory application

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    The lack of specific regulatory guidelines for nanotechnology-enabled health products (NHPs) is hampering development and patient access to these innovative technologies. Namely, there is an urgent need for harmonized regulatory definitions and classification systems that allow establishing a standardized framework for NHPs regulatory assessment. In this work, a novel classification system for NHPs is proposed. This classification can be applied for sorting nano-based innovations and regulatory guidelines according to the type of NHPs they address. Said methodology combines scientific and regulatory principles and it is based on the following criteria: principal mode of action, chemical composition, medical purpose and nanomanufacturing approach. This classification system could serve as a useful tool to sensor the state of the art of NHPs which is particularly useful for regulators to support strategy development of regulatory guidelines. Additionally, this tool would also allow manufacturers of NHPs to align their development plans with their applicable guidelines and standards and thus fulfill regulators expectations
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