A Bayesian model for longitudinal circular data

The analysis of short longitudinal series of circular data may be problematic and to some extent has not been completely developed. In this paper we present a Bayesian analysis of a model for such data. The model is based on a radial projection onto the circle of a particular bivariate normal distribution. Inferences about the parameters of the model are based on samples from the corresponding joint posterior density which are obtained using a Metropolis-within-Gibbs scheme after the introduction of suitable latent variables. The procedure is illustrated both using a simulated data set and a realdata set previously analyzed in the literature.Circular data, Longitudinal data, Gibbs sampler, Latent variables, Mixed-effects linear models, Projected normal distribution

A Bayesian model for longitudinal circular data

The analysis of short longitudinal series of circular data may be problematic and to some extent has not been completely developed. In this paper we present a Bayesian analysis of a model for such data. The model is based on a radial projection onto the circle of a particular bivariate normal distribution. Inferences about the parameters of the model are based on samples from the corresponding joint posterior density which are obtained using a Metropolis-within-Gibbs scheme after the introduction of suitable latent variables. The procedure is illustrated both using a simulated data set and a realdata set previously analyzed in the literature

Evaluación de riesgos por puesto de trabajo para la empresa central American Fisheries S.A ubicada en la ciudad de Managua

Presenta propuesta de un plan de acción para controlar los riesgos laborales identificados mediante la evaluación de puestos así como la identificación de los riesgos y la elaboración de la matriz de riesgo correspondiente a los departamentos y puestos

Individualism, Competitiveness, and Fear of Negative Evaluation in Pre-adolescents: Does the Teacher’s Controlling Style Matter?

The traditional teaching style in which the teacher is in control and there is a submissive attitude in students is predominant in Mexico. The development of identity in preadolescence is subjected to social groups, which could develop interpersonal difficulties through the controlling teaching style. Although the fear of negative evaluation in students and competitive sport has been studied in education, relatively little research has been done in the area of physical education in relation to the controlling style. The purpose of this study was to investigate the correlation and predictive relationship between controlling teaching and the fear of negative evaluation mediated by the frustration of the basic psychological needs (BPN), controlled motivation, and individualism/competitiveness through the theoretical framework of self-determination theory. Participants were 1132 students in the fifth and sixth grades in public elementary schools in the state of Chihuahua, Mexico, with ages between 10 and 13 (M = 10.51 years; SD = 0.66 years). Results indicate the perceived controlling teaching style positively predicted the fear of negative evaluation in students of this study through BPN frustration, that is positively related to low-quality motivation, which is related to a higher level of individualism/competitiveness. This, in turn, is proven to be a predictor of the fear of negative evaluation. The results also discuss the promotion of the autonomy support style, avoiding the controlling teaching style, for the minimization of negative results related to the perception of fear and the development of student well-being both within and beyond the school context

A semiquantitative scoring tool to evaluate eccentric exercise-induced muscle damage in trained rats

Unaccustomed eccentric exercise is a welldocumented cause of exercise-induced muscle damage. However, in trained subjects muscle injury involves only light or moderate tissue damage. Since trained rats are widely used as a model for skeletal muscle injury, here we propose a semiquantitative scoring tool to evaluate muscle damage in trained rats. Twenty male Sprague-Dawley rats were trained for two weeks following a two-week preconditioning period, and randomly divided into two groups: control rats (CTL; n=5) and rats with eccentric exercise-induced muscle damage (INJ; n=15). Injured rats were sacrificed at three time points: 1, 3 and 7 days post injury (n=5 each). Transverse sections from the right soleus were cut (10 μm) and stained with haematoxylineosin. Samples were evaluated by two groups of observers (four researchers experienced in skeletal muscle histopathology and four inexperienced) using the proposed tool, which consisted of six items organised in three domains: abnormal fibre morphology, necrotic/(re) degenerating fibres (muscle fibre domain), endomysial and perimysial infiltration (inflammatory state domain) and endomysium and perimysium distension (interstitial compartment domain). We observed the expected time course in the six evaluated items. Furthermore, agreement among observers was evaluated by measuring the Intraclass Correlation Coefficient (ICC). Within the experienced group, items from the muscle fibre and interstitial compartment domains showed good agreement and the two items from the infiltration compartment domain showed excellent agreement. In conclusion, the proposed tool allowed quick and correct evaluation of light to moderate muscle damage in trained rats with good agreement between observers

Estado del Arte de las Soluciones a Perturbaciones Armónicas en Generadores Eoloeléctricos Interconectados a la Red basados en un Generador Doblemente Alimentado

En las últimas décadas, la tecnología asociada a la generación eoloeléctrica ha avanzado significativamente. Sin embargo, en el contexto de los generadores eoloeléctricos interconectados a la red eléctrica, existen diversas perturbaciones eléctricas que pueden provocar consecuencias negativas en la calidad de la energía. En este artículo se muestra una revisión del estado del arte de los problemas producidos en generadores eoloeléctricos interconectados a red, específicamente debido a perturbaciones armónicas. Se muestran los diferentes escenarios que la literatura reporta sobre las fuentes de los armónicos, su interacción con los generadores eoloeléctricos y las soluciones propuestas por diversos autores. La revisión se centra en sistemas eoloeléctricos basados en el generador doblemente alimentado

Test-retest and minimal detectable change in the assessment of muscle strength and muscle power in upper and lower extremity exercises in 9- to 14-year-old children

The prescription of maximal dynamic strength training in both adults and children is based on the evaluation of maximum strength, usually by one-repetition maximum tests (1RM). This study examined the test-retest reliability and the minimal detectable change (MDC) of the maximal force test and muscle power test. Forty-eight children (9–14 years old) completed two test–retest sessions that involved a one-repetition maximum (1RM) test and a muscle power test for leg extension (LE) and seated bench press (SBP). The MDC values of the 1RM test in the LE and SBP tests ranged from 7.35 to 11.34 kg and 6.84 to 7.92 kg, respectively. The MDC values of the muscle power test in the LE and SBP ranged from 30.32 to 63.20 Watt and 22.65 to 29.53 Watt, respectively. In children 9 to 14 years old, the increase of maximum strength along the growth curve was different in each muscle group studied. The repeatability of the 1RM test of the SBP was excellent (ICC 0.974) and was better than that of the LE (ICC, 0.954). The MDC of the 1RM test evaluation was 19.56% in the LE and 12.93% in the SBP.info:eu-repo/semantics/publishedVersio

Modelado y control de un generador de SAGS basado en un convertidor back to back

En las últimas décadas, la tecnología asociada a la generación eoloeléctrica ha avanzado significativamente, sin embargo, en el contexto de los generadores eoloeléctricos interconectados a la red eléctrica, existen diversas perturbaciones eléctricas que pueden provocar consecuencias negativas en la calidad de la energía, así como el posible daño del generador. Entre las perturbaciones eléctricas que más preocupa en el contexto de los generadores eoloeléctricos interconectados, está el SAG o hueco de tensión. Actualmente existen esfuerzos por desarrollar soluciones que ayuden a mitigar los efectos de los SAGs; sin embargo, cuando se trata de probar estas soluciones es necesario contar con un mecanismo que permita emular la presencia de SAGs en la red eléctrica.En este sentido, este trabajo muestra el modelado y control de un generador de SAGs basado en un convertidor back to back utilizando control vectorial orientado al voltaje de red, cuya obtención del ángulo de dicho marco de referencia se realiza a través de un lazo de seguimiento de fase (PLL por sus siglas en inglés). Este generador es capaz decrear caídas de tensión de magnitud y duración variable, cuyo buen desempeño queda demostrado con una serie de simulaciones implementadas en PSIM.Palabra(s) Clave(s): back to back, control vectorial, SAGs, PLL

Diseño de compuestos multiblanco basado en similitudes de sitios de unión entre las estructuras de SERT y EAAT3 como potencial alternativa farmacológica para el tratamiento del Trastorno Obsesivo Compulsivo

49 p.A nivel mundial, se estima que el Trastorno Obsesivo Compulsivo (TOC) tiene una prevalencia en la población que varía del 2 a 3%, es un trastorno de carácter invalidante que se caracteriza por comportamientos repetitivos que invaden la conducta y la calidad de vida de las personas. Su etiología no está del todo clara, algunos modelos evidencian alteraciones en los circuitos frontoestriatales cerebrales, aun así, se indica que los componentes ambientales y genéticos serían su principal causa. En ese sentido, el TOC estaría influenciado por genes que modulan los sistemas serotoninérgico y glutamatérgico. En el sistema glutamatérgico, se ha demostrado que la transmisión excitatoria anormal en el SNC, vinculada a la función del transportador de glutamato EAAT3, sería un factor promotor de la enfermedad. En cuanto a, el sistema serotoninérgico bajos niveles de serotonina 5-HT han demostrado una sobreexcitación neuronal en zonas del cerebro ocurrentes de TOC. Hoy, los ISRS son el tratamiento de primera línea para la enfermedad, aún cuando su desarrollo farmacéutico es para la depresión mayor, estas drogas actúan bloqueando a SERT en el espacio sináptico, asimismo como compuestos que modulan el glutamato. El tratamiento farmacológico combinado con la psicoterapia han sido útiles para mantener a raya los síntomas, sin embargo estos reaparecen en casi la mitad de los pacientes, por lo cual se aprecia la necesidad urgente de un tratamiento farmacológico para TOC. La mayoría de los fármacos son desarrollados bajo el paradigma de “bala mágica”, que implica un diseño de compuestos altamente selectivos, pero en la práctica las drogas son naturalmente promiscuas y trastornos como el TOC son cuadros complejos que a menudo incluyen una amplia gama de objetivos, he ahí el perfil polifarmacológico. Las estructuras de SERT y EAAT3 humanas se utilizaron como blanco polifarmacológico, por ello, estas se equilibraron mediante simulaciones de DM, se determinaron 4 receptoforos mediante la búsqueda y descubrimiento de patrones comunes con la herramienta Geomfinder, se construyó una librería de compuestos a través de un modelo heurístico de algoritmo genético usando LEA3D para cada receptoforo. Travoprost, Ticagrelor, NRX-1074 y Rapastinel fueron los 4 compuestos seleccionados y sometidos a simulaciones de acoplamiento molecular en ambas estructuras en la suite Schrodinger Maestro. Travoprost, siendo una solución oftalmológica para el glaucoma presenta interacciones de tipo enlaces de hidrógeno en los residuos de Asp y Arg tanto en EAAT3 como SERT con puntajes de acoplamiento de -7.362 y -8.062 kcal/mol, respectivamente

Ultrasound-assisted extraction of fructans from agave (Agave tequilana Weber var. azul) at different ultrasound powers and solid-liquid ratios

Abstract The effects of ultrasound-assisted extraction (UAE) at different ultrasound power densities (UPDs; 40, 80, and 120 mW/mL) and solid:liquid (S:L) ratio (1:2, 1:3, and 1:6) on the extraction of carbohydrates from Agave tequilana plant of different ages were evaluated. Extracts obtained (6- and 7-year-old plant) were analyzed in the yield of carbohydrates (YC), fructan (FRU) content, simple sugars, fructan profile and the average degree of polymerization (DPn). UPD, S:L ratio, and plant age all affected YC, FRU, and DPn. Maximum YC and FRU were obtained from the older agave with UPD and S:L ratio of 120 mW/mL and 1:6, respectively; while glucose, fructose, and sucrose were highly released from the younger plant. Agave of 7-year-old presented the highest DPn. Fructan degradation occurred at high UPD, increasing the simple sugars and decreasing the DPn. Thermal-traditional extraction without sonication caused more fructan degradation; and overall, ultrasound enhanced fructan extraction and minimized fructan damage, representing a technological alternative for fructan extraction from agave. Keywords: agave; fructans; ultrasound; power density; solid:liquid ratio; plant age. Practical Application: Agave tequilana Weber var. azul plants have significant amounts of fructans. Extraction of these components by alternative methods such as ultrasound could represent advantages, improving the extraction and product quality. This research presents an alternative for the extraction of fructans assisted with ultrasound, evaluating different powers and solid-liquid ratios from agave heads of two different ages. Both variables, as well as age of agave showed a strong effect on fructan extraction. Ultrasound enhanced the extraction and minimized fructan damage, representing a technological alternative