K-means algorithms for functional data

Cluster analysis of functional data considers that the objects on which you want to perform a taxonomy are functions f : X e Rp ↦R and the available information about each object is a sample in a finite set of points f ¼ fðx ; y ÞA X x Rgn . The aim is to infer the meaningful groups by working explicitly with its infinite-dimensional nature. In this paper the use of K-means algorithms to solve this problem is analysed. A comparative study of three K-means algorithms has been conducted. The K-means algorithm for raw data, a kernel K-means algorithm for raw data and a K-means algorithm using two distances for functional data are tested. These distances, called dVn and dϕ, are based on projections onto Reproducing Kernel Hilbert Spaces (RKHS) and Tikhonov regularization theory. Although it is shown that both distances are equivalent, they lead to two different strategies to reduce the dimensionality of the data. In the case of dVn distance the most suitable strategy is Johnson–Lindenstrauss random projections. The dimensionality reduction for dϕ is based on spectral methods

Teaching foreign language implementing human values activities

El objetivo principal de este proyecto es reportar el impacto de la instrucción de los valores humanos, a través de la clase de inglés a estudiantes de grado séptimo. Observar las reflexiones y perspectivas de los estudiantes acerca de las actividades aplicadas en la instrucción de los valores humanos estuvo presente como objetivo especifico durante la realización del presente proyecto. El estudio se basó en el fortalecimiento de los valores de los estudiantes a través de la clase de inglés, además los educandos tuvieron la oportunidad de optimizar aspectos del idioma como vocabulario, pronunciación, lectura, escritura y producción oral. Las actividades de este proyecto se llevaron a cabo de manera grupal, con el fin de lograr que los estudiantes se integraran e intercambiaran información, y se conocieran más a fondo. El propósito de dichas actividades era impulsar a los estudiantes a reflexionar acerca de diferentes situaciones que se podrían presentar en la vida cotidiana, así como también a expresar sus perspectivas, pensamientos y sentimientos respecto a estas. El impacto que causó en los estudiantes la aplicación de los valores humanos en la clase de Inglés, se reflejó en los resultados principales de este estudio, tales como; el punto de vista de los estudiantes acerca de la instrucción de los valores humanos en la clase de Inglés, y el desarrollo de las habilidades del idioma extranjero, además del fortalecimiento de lazos y autoconciencia a través de la interacción de los estudiantes. Finalmente, obtuvimos un resultado inesperado de este estudio el cual fue el hecho de que los estudiantes notaron la metodología de las clases utilizada en este proyecto comparado con la metodología de sus clases de inglés habituales. Como conclusiones, sugerimos llevar a cabo el mismo contenido de valores humanos en otras materias además del inglés, teniendo en cuenta el rol de modelos que tienen los profesores y padres de familia, frente a los estudiantes. Finalmente concluimos que entre más tenga relación el contenido con la realidad, mas se envolverán los estudiantes con la clase, ya que de esta manera podrían aplicar lo aprendido en clase a su contexto real.The main objective of this project is to report, the impact of the human values instruction through the English class in seventh graders. Observing the students’ reflections and perspectives about the activities of the human values instruction was the specific objective of the present project. The focus of the study was strengthen students’ human values through the English class, besides the learners had the possibility to optimize aspects of the foreign language like vocabulary, pronunciation, reading, writing and speaking. The activities of this project were carried collectively, with the purpose of enable the students integrated among them and interchanging information; additionally students could know better each other. The purpose of the activities was to make the students reflect on different possible situations in the daily life. Furthermore, the learners were also encouraged to express their perspectives, thoughts, and feelings related to those circumstances. The impact that the human values instruction caused in the students through the English class, was reflected in the main results of this study, such as the students’ point of view about the content class, English skills development, and the bonding and self consciousness improvement through the group interaction. Finally, we obtained an unexpected finding from this research which was that the students noticed the methodology used in the classes of the study in comparison with their regular English classes. As conclusions we suggested to carried out the same content of human values in other subjects beside English, taking into account the teachers’ and parents’ role model respect to the students. Finally we conclude that the more relation has the content with reality, the more students get involved in the class, because they can use in their real context what they learnt during the lessons

A bilevel approach to enhance prefixed traffic signal optimization

The segmentation of multivariate temporal series has been studied in a wide range of applications. This study investigates a challenging segmentation problem on traffic engineering, namely, identification of time-of-day breakpoints for pre-fixed traffic signal timing plans. A large number of urban centres have traffic control strategies based on time-of-day intervals. We propose a bilevel optimization model to address simultaneously the segmentation problems and the traffic control problems over these time intervals. Efficient memetic algorithms have been developed for the bilevel model based on the hybridization of the particle swarm optimization, genetic algorithms or simulated annealing with the Nelder–Mead method. Numerically the effectiveness of the algorithms using real and synthetic data sets is demonstrated. We address the problem of automatically estimating the number of time-of-day segments that can be reliably discovered. We adapt the Bayesian Information Criterion, the PETE algorithm and a novel oriented-problem approach. The experiments show that this last method gives interpretable results about the number of reliably necessary segments from the traffic-engineering perspective. The experimental results show that the proposed methodology provides an automatic method to determine the time-of-day segments and timing plans simultaneously.La segmentación de series temporales multivariadas ha sido estudiada en una amplia gama de aplicaciones. Este estudio investiga un problema de segmentación desafiante en la ingeniería de tráfico, a saber, la identificación de puntos de interrupción de la hora del día para planes de sincronización de señales de tráfico prefijados. Un gran número de centros urbanos tienen estrategias de control de tráfico basadas en intervalos de tiempo del día. Proponemos un modelo de optimización binivel para abordar simultáneamente los problemas de segmentación y los problemas de control de tráfico en estos intervalos de tiempo. Se han desarrollado algoritmos meméticos eficientes para el modelo binivel basados ​​en la hibridación de la optimización del enjambre de partículas , algoritmos genéticos o recocido simulado con el método Nelder-Mead. Numéricamente se demuestra la eficacia de los algoritmos utilizando conjuntos de datos reales y sintéticos. Abordamos el problema de estimar automáticamente la cantidad de segmentos de hora del día que se pueden descubrir de manera confiable. Adaptamos el Criterio de Información Bayesiano, el algoritmo PETE y un enfoque novedoso orientado al problema. Los experimentos muestran que este último método da resultados interpretables sobre el número de segmentos fiablemente necesarios desde la perspectiva de la ingeniería de tráfico. Los resultados experimentales muestran que la metodología propuesta proporciona un método automático para determinar los segmentos de tiempo del día y los planes de tiempo simultáneament

Exact solutions through symmetry reductions for a high-grade brain tumor model with response to hypoxia.

Mathematical biology models can simulate cell behavior scenarios, specifically for tumor proliferation. In this paper, we study a continuous model describing the evolution of high-grade gliomas from the point of view of the theory of symmetry reductions in partial differential equations (PDEs). Malignant gliomas are the most frequent and deadly type of brain tumor. Over the last few years, complex mathematical models of cancerous growths have been developed increasingly, especially on solid tumors, in which growth primarily comes from abnormal cellular proliferation. The presented PDE system includes two different cellular phenotypes, depending on their oxygenation level. Furthermore, this mathematical model assumes that both phenotypes differ in migration and proliferation rates. Specifically, it includes the possibility of hypoxic cells diffusing into well-oxygenated areas of a tumor. Our main findings are obtained through the classical symmetries admitted by the proposed system, and transformation groups are used to reduce the PDE system to ordinary differential equations. By these means, we provide not only exact solutions but also capture a 3-dimensional representation of the biological phenomenon. The simulations provided show the relationship between normoxic and hypoxic phenotypes in high-grade gliomas

Major dietary patterns and risk of frailty in older adults: A prospective cohort study

Background: There is emerging evidence of the role of certain nutrients as risk factors for frailty. However, people eat food, rather than nutrients, and no previous study has examined the association between dietary patterns empirically derived from food consumption and the risk of frailty in older adults. Methods: This is a prospective cohort study of 1,872 non-institutionalized individuals aged ≥60 years recruited between 2008 and 2010. At baseline, food consumption was obtained with a validated diet history and, by using factor analysis, two dietary patterns were identified: a ‘prudent’ pattern, characterized by high intake of olive oil and vegetables, and a ‘Westernized’ pattern, with a high intake of refined bread, whole dairy products, and red and processed meat, as well as low consumption of fruit and vegetables. Participants were followed-up until 2012 to assess incident frailty, defined as at least three of the five Fried criteria (exhaustion, weakness, low physical activity, slow walking speed, and unintentional weight loss). Results: Over a 3.5-year follow-up, 96 cases of incident frailty were ascertained. The multivariate odds ratios (95% confidence interval) of frailty among those in the first (lowest), second, and third tertile of adherence to the prudent dietary pattern were 1, 0.64 (0.37–1.12), and 0.40 (0.2–0.81), respectively; P-trend = 0.009. The corresponding values for the Westernized pattern were 1, 1.53 (0.85–2.75), and 1.61 (0.85–3.03); P-trend = 0.14. Moreover, a greater adherence to the Westernized pattern was associated with an increasing risk of slow walking speed and weight loss. Conclusions: In older adults, a prudent dietary pattern showed an inverse dose-response relationship with the risk of frailty while a Westernized pattern had a direct relationship with some of their components. Clinical trials should test whether a prudent pattern is effective in preventing or delaying frailtyBaseline data collection was funded by Sanofi-Aventis. Data collection during follow-up was funded by the Spanish Government grants 09/1626 and 09/0104 (Ministry of Health of Spain). Funding specific for this analysis was obtained from the Spanish Government grant 12/1166 (Ministry of Health of Spain) and the FP7-HEALTH-2012-Proposal No: 305483–2 (FRAILOMIC Initiative). Funders had no role in data analyses, preparation of the manuscript, or in the decision to submit it for publicatio

Passenger Centric Train Timetabling Problem with elastic demand

A wide taxonomy of the adopted design criterion in models for Train Timetabling Problem (TTP), considers two kinds of models: operations-centric models, which are focused on railway operations and assume the demand has been considered and modeled in the design stage of the railway network, and passenger-centric models, which tries to maximize customers satisfaction. The first models have been widely studied since historically, the train operating companies (TOC) had a monopoly in the railway market. Currently, and because of the European directive (EU Directive 91/440) which allows the competition between different TOC, the research interest in the second kind of models is increasing. This paper proposes a mathematical model for TTP which includes the elasticity of the demand against the characteristics of supply. To do that, the proposed model is based on the concept of strategy and by means of the use of radial-basis functions, the demand model allows to estimate the number of passengers in each strategy on the network, taking into account the existing correlation between strategies

Non-invasive biomonitoring of infant exposure to environmental organic pollutants in north-western Spain based on hair analysis. Identification of potential sources

Recent years have seen growing interest in hair sample analysis to detect organic pollutants (OPs). This biological matrix can be analysed non-invasively for biomonitoring of OPs over a wide exposure window. Obtaining hair sample amounts that meet the needs of the analytical methodology required for the determination of the POs of interest can be challenging, especially in infants. As a result, studies assessing organic pollutants in infant hair have been very scarce. We quantified levels of about 60 OPs, including persistent organic pollutants (POPs), in 110 hair samples from a patient cohort (60 mothers and 50 infants) from Santiago de Compostela (north-western Spain). For each participant we examined relationship between OP levels and corresponding epidemiological parameters using correlations, principal component analysis (PCA), hierarchical cluster analysis, and Multivariate analysis of variance (MANOVA). For many OPs we observed significant correlations with place of residence, parity, and maternal age, as well as pet ownership. Evaluation of dietary habits showed significant associations between levels some OPs and the consumption of fish, molluscs, and cereal. There were significant associations between chlorpyrifos and deltamethrin levels and infant birth characteristics such as birthweight and head circumference. Relations between OP levels in the hair of mothers and their infants were also examined, revealing common sources of exposure for dioxin-like polychlorinated biphenyls (DLPCBs), non-dioxin-like polychlorinated biphenyls (NDLPCBs), polybrominated diphenyl ethers (PBDEs), and polycyclic aromatic hydrocarbons (PAHs). Levels of fluoranthene (F), pyrene (P), endrin, and some PBDEs in maternal hair were significantly correlated with those in infant hair. Our findings identified common sources of exposure to OPs of distinct chemical classes.Xunta de Galicia | Ref. GRC-ED431C 2022/35Universidade de Vigo/CISU

Ca2 + Dynamics in chemoreceptor cells: an overview

Producción CientíficaThe carotid body (CB) was defined as a sensory organ by De Castro in 1928. Two years later, Heymanns and coworkers demostrated that the organ was sensitive to alterations in blood gases and pH, in such a way that a decrease in blood P02 or pH or an increase in blood PC02 produced activation of the CB and, reflexely, hyperventilation. De Castro postulated that glomus cells were the sensor structures and that they should release sorn substance to transmit the stimulus to the sensory nerve endings (De Castro, 1928). De Castro's point of view, was widely accepted, and therefore the CB was considered a secondary sensory receptor. As a consequence, the principal aims of many workers in the chemoreception field have been to define the nature of the sensing mechanims ( sensory transduction process ) and to identify the substances released by chern cells

Combined impact of traditional and non-traditional health behaviors on mortality: A national prospective cohort study in Spanish older adults

Background: Data on the combined effect of lifestyles on mortality in older people have generally been collected from highly selected populations and have been limited to traditional health behaviors. In this study, we examined the combined impact of three traditional (smoking, physical activity and diet) and three non-traditional health behaviors (sleep duration, sedentary time and social interaction) on mortality among older adults. Methods: A cohort of 3,465 individuals, representative of the Spanish population aged ≥60 years, was established in 2000/2001 and followed-up prospectively through 2011. At baseline, the following positive behaviors were selfreported: never smoking or quitting tobacco >15 years, being very or moderately physically active, having a healthy diet score ≥ median in the cohort, sleeping 7 to 8 h/d, spending <8 h/d in sitting time, and seeing friends daily. Analyses were performed with Cox regression and adjusted for the main confounders. Results: During an average nine-year follow-up, 1,244 persons died. Hazard ratios (95% confidence interval) for allcause mortality among participants with two, three, four, five and six compared to those with zero to one positive behaviors were, respectively, 0.63 (0.46 to 0.85), 0.41 (0.31 to 0.55), 0.32 (0.24 to 0.42), 0.26 (0.20 to 0.35) and 0.20 (0.15 to 0.28) (P for trend <0.001). The results were similar regardless of age, sex and health status at baseline. Those with six vs. zero to one positive health behaviors had an all-cause mortality risk equivalent to being 14 years younger. Adding the three non-traditional to the four traditional behaviors improved the model fit (likelihood ratio test, P <0.001) and the accuracy of mortality prediction (c-statistic: + 0.0031, P = 0.040). Conclusions: Adherence to some traditional and non-traditional health behaviors may substantially reduce mortality risk in older adults.This work was funded by grants from the FIS (ref. 12/1166) and the ‘Plan Nacional sobre Drogas’ (ref. 06/2010), and by the ‘Cátedra UAM de Epidemiología y Control del Riesgo Cardiovascular’. DMG had a “Juan de la Cierva” contract from the Spanish Ministry of Scienc

Coordinación interdisciplinar y Aprendizaje basado en problemas: Educación Superior

The aspect of the European Higher Education Area is the need to educate students using a multidisciplinary approach. The undergraduates should also acquire competencies that will be essential in their future profession. The interdisciplinary approach provides many benefits that develop into much needed lifelong, learning interdisciplinary coordination of two subjects of Degree for the achievement of the competencies and the skills of students. In this context, this work describes an educational constructivist, innovation consisting of interdisciplinary coordination between two subjects from the Bachelor’s Degree in Business Administration and Management: Production Management and Business Statistics, using Problem-based learning (PBL). As secondary objectives we set out, to intend, to encourage the participation and implication of students through the proposals of real problems and motivators; to ensure that students have a global and integrating vision of the production and operations function and the possibilities of statistical techniques; to Improved communication between students and teachers, promoting teamwork and work together with some of the necessary skills in the degree. We ran the educational innovation project over three consecutive academic years, the results demonstrate that acquiring knowledge via interdisciplinary coordination is highly valued by students and also allows them to acquire competencies that will be essential in their future careers. It highlights the need for a policy maker to evaluate an interdisciplinary curriculum.El objetivo del Espacio Europeo de Educación Superior es la necesidad de educar a los estudiantes utilizando un enfoque multidisciplinario. Los estudiantes de grado también deben adquirir competencias que serán esenciales en su futura profesión. El enfoque interdisciplinar proporciona muchos beneficios que se convierten en habilidades de aprendizaje para toda la vida y que son esenciales para el aprendizaje futuro del estudiante. El objetivo de este trabajo es aplicar la coordinación interdisciplinaria de dos asignaturas de grado para el logro de las competencias y habilidades de los alumnos. En este contexto, este trabajo describe una innovación educativa constructivista, que consiste en la coordinación interdisciplinaria entre dos asignaturas de la Licenciatura en Administración y Dirección de Empresas: Gestión de la Producción y Estadística Empresarial, utilizando el aprendizaje basado en problemas (PBL). Como objetivos secundarios nos propusimos fomentar la participación e implicación de los estudiantes a través de propuestas de problemas reales y motivadores; asegurar que los estudiantes tengan una visión global e integradora de la función de producción y técnicas estadísticas; mejorar la comunicación entre alumnos y docentes, promoviendo el trabajo en equipo y el trabajo conjunto. Ejecutamos el proyecto de innovación educativa durante tres años académicos consecutivos, los resultados demuestran que la adquisición de conocimiento a través de la coordinación interdisciplinar, que resulta muy valorada por los estudiantes y también les permite adquirir competencias que serán esenciales en sus futuras carreras profesionales. Destaca la necesidad de que un responsable de políticas educativas evalúe un plan de estudios interdisciplinar