Helical propulsion in shear-thinning fluids

Swimming micro-organisms often have to propel themselves in complex non-Newtonian fluids. We carry out experiments with self-propelling helical swimmers driven by an externally rotating magnetic field in shear-thinning inelastic fluids. Similarly to swimming in a Newtonian fluid, we obtain for each fluid a locomotion speed that scales linearly with the rotation frequency of the swimmer, but with a prefactor that depends on the power index of the fluid. The fluid is seen to always increase the swimming speed of the helix, up to 50 % faster, and thus the strongest of such type reported to date. The maximum relative increase is for a fluid power index of approximately 0.6. Using simple scalings, we argue that the speed increase is not due directly to the local decrease of the flow viscosity around the helical filament, but hypothesise instead that it originates from confinement-like effect due to viscosity stratification around the swimmer.This work was funded in part by the European Union (CIG grant to E.L.). R.Z. acknowledges the financial support of the Moshinsky Foundation and the PAPIIT-DGAPA-UNAM program (grant no. IN101312)

Os problemas internalizados e externalizados na competência acadêmica de escolares

Several studies emphasize the high prevalence of internalizing and externalizing problems (I&EP) in childhood and the impact they have on academic competence (AC). In Mexico, there is little empirical evidence about this topic, so it is important to test the relationship between I&EP and AC in school children, in order to have indicators that may guide the design of interventions. The aim of this study was to analyze the scores obtained on AC indicators in three groups of children with differentials levels of I&EP. The sample was composed by 314 children from public schools, aged between 8 and 12 years, 51% girls and 49% boys. The Internalizing and Externalizing Problems Questionnaire (IEPQ), a Checklist of Demographic Data, the Raven's Progressive Matrices Test, and Academic Competence Tests were administered. A cross-sectional study of comparison groups was carried out. The tests were administered in a group manner in the classrooms. The SPSS v.20 was used for data analysis. Three clusters of I&EP were formed and the scores obtained by each cluster on AC indicators were analyzed and compared through MANOVA. Data showed significant effects on writing in the groups of internalizing problems (IP) and on reading in the groups of externalizing problems (EP). Results about the influence of I&EP on AC are discussed.Diversos estudios destacan la elevada prevalencia de problemas internalizados y externalizados (PIyE) en la niñez, así como sus repercusiones en la competencia académica (CA). En México existe poca evidencia empírica al respecto, por lo que resulta relevante analizar esta relación para contar con indicadores que guíen el diseño de intervenciones. El objetivo del trabajo fue comparar los puntajes obtenidos en indicadores de CA en tres grupos de niños con niveles diferenciados de PIyE. Se trabajó con 314 niños con edades entre 8 y 12 años de primarias públicas, 51% niñas y 49% niños. Se aplicaron cuatro instrumentos: Cuestionario de Problemas Internalizados y Externalizados (CPIEN), Ficha Socio-demográfica para Niños, Escala de Inteligencia Coloreada Raven, y Pruebas Académicas. Se realizó un estudio transversal de comparación de grupos. Las pruebas se aplicaron de manera grupal en los salones de clases. El análisis estadístico se realizó mediante el programa SPSS v.20. Se conformaron tres grupos en función de los niveles de PIyE, y se compararon las puntuaciones que cada grupo obtuvo en los indicadores de CA por medio del MANOVA. Los datos mostraron efectos significativos en escritura en los grupos de problemas internalizados (PI), y en lectura en los grupos de problemas externalizados (PE). Se discuten los resultados de la influencia de los PIyE sobre la CA.Diversos estudos destacam a elevada prevalência de problemas internalizados e externalizados (PIyE) na infância, bem como suas repercussões na competência acadêmica (CA). No México existe pouca evidência empírica a respeito, por isso é relevante analisar esta relação para contar com indicadores que guiem o desenho de intervenções. O objetivo do trabalho foi comparar as pontuações obtidas de CA em três grupos de crianças com níveis diferenciados de PIyE. Trabalhou-se com 314 crianças com idades entre 8 e 12 anos de escolas primárias públicas, 51% meninas e 49% meninos. Aplicaram-se quatro instrumentos: Questionário de Problemas Internalizados e Externalizados (CPIEN), Ficha Sócio demográfica para crianças, Escala de Inteligência Raven, e Testes Acadêmicos. Realizou-se um estudo transversal de comparação de grupos. Os testes foram aplicados de maneira grupal nas salas de aula. A análise estatística realizou-se mediante o programa SPSS v.20. Formaram-se três grupos em função dos níveis de PIyE, e compararam-se as pontuações que cada grupo obteve nos indicadores de CA através do MANOVA. Os dados mostraram efeitos significativos em escritura nos grupos de problemas internalizados (PI), e em leitura nos grupos de problemas externalizados (PE). Discutem-se os resultados da influência dos PIyE sobre a CA

Propuesta de reconformación del espacio público para fortalecer el tejido social en el nuevo malecón de Jamay, Jalisco

El proyecto, propuesta de reconformación del espacio público para fortalecer el tejido social en el nuevo malecón de Jamay, Jalisco busca participar en proyectos ya existentes en la localidad para generar una mejora social, turística y económica en la zona mediante simples cambios que procuran hacer en este caso del corredor libertad una atmósfera culturalmente importante sobre la ribera de chapala.ITESO, A.C

Efficiency Analysis of Mexican Stock Exchange Sustainable Firms

This research aims at analyzing the impact that the variables of sustainable value generation (ESG) have on the efficiency of firms listed on the Mexican Stock Exchange Sustainable Index during the period 2014-2017. The non-parametric method of Data Envelopment Analysis (DEA) was used to determine their efficiency. Results indicate that, given the level of profitability, the variable that most affects the generation of sustainable value is corporate governance (G), followed by environmental (E) and social (S) practices. The main limitation of the study is the sample size. The originality of this paper lies in the fact that it determines corporate efficiency using financial performance as an input of a DEA model and sustainable value ratings as outputs. Conclusions show that corporate social responsibility activities may enhance firms’ sustainable efficiency. Therefore, it is proposed that corporate efficiency might be complemented by sustainable value measurements.Análisis de Eficiencia de Empresas Sustentantes de la Bolsa Mexicana de ValoresEn esta investigación se analiza el impacto de las variables de generación de valor sustentable (ESG) en la eficiencia de las empresas que calificaron para pertenecer al Índice de Sustentabilidad de la Bolsa Mexicana de Valores durante el periodo 2014-2017. La eficiencia se determinó utilizando el método no paramétrico del Análisis Envolvente de Datos (DEA). Los resultados indican que, dado el nivel de rentabilidad, la variable que mayormente incide en la generación de valor sustentable es gobierno corporativo (G), seguida de medio ambiente (E) y prácticas sociales (S). La principal limitación del estudio radica en el tamaño de la muestra. La originalidad de esta investigación consiste en determinar la eficiencia corporativa utilizando el desempeño financiero como input y las calificaciones de valor sustentable como outputs del modelo DEA.  Como conclusión, esta investigación muestra que las acciones de responsabilidad social contibuyen a incrementar la eficiencia sustentable de las empresas, por lo que se propone que la medición del valor sustentable sea complemento de la evaluación de la eficiencia corporativa

Therapeutic potential of topical administration of siRNAs against HIF-1α for corneal neovascularization.

Given the implications of the problem of neovascularization on ocular health, as well as the growth in the number of cases, the purpose of the present study has been testing the efficacy of siRNAs (small interfering RNA) designed to silence Hypoxia Inducible Factor -1α (HIF-1α) and to demonstrate that their use stops neovascularization in a model of corneal burn. Corneal wounds in the limbic zone were made in the eyes of New Zealand white rabbits. Topical applications of siRNAs were done the next day to the wound for four consecutive days and eyes were examined with a slit lamp. Evaluation of neovascularization progress was done by analyzing images by ImageJTM and to determine the neovascular area in Matlab ® was used. At the same time, a rabbit corneal cell line was used for in vitro study of hypoxia exposure and Western blot analysis of the cell's extracts were done. Under normal cell culture oxygenation, the expression of HIF-1α was lower than that observed under hypoxic conditions. After 2 h of hypoxia, there was a significant increase in the HIF-1α expression, effect that was maintained up to 6 h. The increased in HIF-1α was mimicked by a cell permeable prolyl-4-hydroxylase inhibitor. Cobalt chloride showed no capacity to increase HIF-1α in vitro. The effect of three different siRNA on HIF-1α was tested after 4 h of hypoxia. siRNA#1 was able to silence 80% of HIF-1α expression, siRNA#2 and siRNA#3 reduce the expression in 45% and 40% respectively. In addition, the three siRNA were tested in a corneal model of neovascularization. scrambledsiRNA#2 was the most effective inhibitor of blood vessel production, followed by siRNA#3 and siRNA#1. Compared to the scrambled siRNA (100% of blood vessel generation), siRNA#2 blocked the presence of blood vessels by 83 ± 2%, siRNA#3 inhibited 45 ± 7% and siRNA#1 only inhibited 18 ± 5%. The necessary time to observe the 50% of effect showed values of NV50 of 10.2 ± 2.4 days for the scrambled siRNA, 9.1 ± 1.4 for siRNA#1, 6.5 ± 1.85 for siRNA#2 and 4.8 ± 1.8 days for siRNA#3. In conclusion, the topical application of siRNA towards HIF-1α seems to be an effective and reliable method to stop neovascularization.This work was supported by a grant from Ministerio de Ciencia e Innovación (SAF2010-16024 and SAF2013-44416-R) and RETICS (RD12/0034/0003), and a grant from the Instituto de Salud Carlos III of Spain and Fondo Europeo de Desarrollo Regional (FEDER, “Una manera de hacer Europa”) (FIS-FEDER PI07-1168 to J. Mateo)S

Estrés y afrontamiento en niños institucionalizados y no institucionalizados

A study was carried out in order to know the differences in the level of stress experienced by institutionalized children, and also to know the types and coping strategies employed by them in comparison with non-institutionalized children. Also, the influence of stress in coping was analyzed by a lineal regression. Participants were 126 children (65 institutionalized and 61 non-institutionalized, age M = 10 years, age range 8 to 12 years. Children Stress Scale (EIE), Children Coping scale (EIA) and a socio-demographic profile were administered. The results showed higher levels of stress in institutionalized children compared to their non institutionalized peers (t = 3.298, P = 0.001) Statistically significant differences were obtained also in the types and the strategies that both groups employ to address their problems. The regression analysis showed that stress predicts dysfunctional and emotional coping strategies with respect to institutionalized children. These results have important implications for child socio-emotional development and hence the importance of early intervention in the population of institutionalized children is a priority.Se realizó un estudio con el propósito de conocer las diferencias en el nivel de estrés que experimentan los niños en situación de institucionalización, así como los tipos y estrategias de afrontamiento que emplean respecto a sus iguales no institucionalizados. Asimismo, se analizó la influencia del estrés en el afrontamiento a través de una regresión lineal. Para esto, se trabajó con 126 niños (65 institucionalizados y 61 no institucionalizados, edad M = 10 años, rango de edad de 8 a 12 años. Se empleó la Escala Infantil de Estrés (EIE), la Escala Infantil de Afrontamiento (EIA) y una ficha sociodemográfica. Los resultados obtenidos indicaron mayores niveles de estrés en los niños institucionalizados en comparación con sus iguales no institucionalizados (t = 3,298; p = 0,001). Además, se encontraron diferencias estadísticamente significativas tanto en los tipos como en las estrategias que emplean ambos grupos para afrontar sus problemas. Respecto a los resultados de las relaciones entre el estrés y el afrontamiento, se observó que el primero predice las estrategias de tipo disfuncional y centrado en la emoción, en el caso de los niños institucionalizados. Estos resultados tienen implicaciones importantes en el desarrollo socioemocional infantil y, por ende, se debe priorizar en la intervención temprana de los niños institucionalizados

Factores Pedagógicos que inciden en el rendimiento académico de la asignatura de Informática Básica de la modalidad Profesionalización de la Facultad de educación e Idiomas de la UNAN-Managua, durante el primer semestre del año 2019

La presente investigación tiene como finalidad realizar una valoración acerca del rendimiento académico de los estudiantes en la asignatura de Informática Básica de la modalidad Profesionalización de la Facultad de Educación e Idiomas, de la UNAN Managua, durante el primer semestre del año lectivo 2019. En esta investigación se abordan algunos de los factores pedagógicos que inciden sobre el rendimiento académico, se describen las características particulares de las modalidades de estudio B-Learning, la influencia de la experiencia docente y los recursos didácticos que emplea al impartir una asignatura en la modalidad B-Learning así como algunos aspectos teóricos acerca de las Tecnologías de la Información y la Comunicación. Asimismo, se utiliza el enfoque cualitativo ya que se pretende obtener puntos de vista y opiniones de los estudiantes acerca de la metodología empleada por el docente en la asignatura de Informática Básica, así como de las dificultades que experimentan en el aprendizaje de esta asignatura por medio de un cuestionario con preguntas abiertas. Además, esta investigación es descriptiva ya que se pretende reunir información acerca de los factores pedagógicos que inciden sobre el rendimiento académico, para luego describir los resultados con la ayuda del marco teóric

Evaluation of microbiological safety in bioinputs produced in Mexico

Objective: This work aimed to evaluate the microbiological safety of bioinputs produced in Mexico. The main reason for this evaluation is that bioinputs are products made from the region's manures, plant residues and raw materials. The transformation of these raw materials is carried out by microorganisms present. The process goes through three stages: initial, thermophilic and final. The thermophilic stage is critical because weeds and microorganisms with pathogenic potential disappear in processes under optimal conditions. Methodology: 1345 bioinputs samples were received from different states of Mexico. The samples were evaluated for the presence of total and fecal coliforms and Escherichia coli under the provisions of the Official Mexican STANDARDS, NOM-210-SSA1-2014 and NOM-114-SSA1-1994. Results: It was possible to identify 79% of the samples with Most Probable Number values <3 of total coliforms, fecal coliforms and Escherichia coli, the minimum permissible by the Official Mexican STANDARD NOM-210-SSA1-2014, also identified 99% of samples free of Salmonella. Conclusions: The results obtained allow us to conclude that the bioinputs produced in Mexico are free of pathogens for humans, which can also be represented as innocuous bioinputs.  Objective: This work aimed to evaluate the microbiological safety of bioinputs produced in Mexico. The main reason for this evaluation is that bioinputs are products made from the region's manures, plant residues and raw materials. The transformation of these raw materials is carried out by microorganisms present. The process goes through three stages: initial, thermophilic and final. The thermophilic stage is critical because weeds and microorganisms with pathogenic potential disappear in processes under optimal conditions. Methodology: 1345 bioinputs samples were received from different states of Mexico. The samples were evaluated for the presence of total and fecal coliforms and Escherichia coli under the provisions of the Official Mexican STANDARDS, NOM-210-SSA1-2014 and NOM-114-SSA1-1994. Results: It was possible to identify 79% of the samples with Most Probable Number values <3 of total coliforms, fecal coliforms and Escherichia coli, the minimum permissible by the Official Mexican STANDARD NOM-210-SSA1-2014, also identified 99% of samples free of Salmonella. Conclusions: The results obtained allow us to conclude that the bioinputs produced in Mexico are free of pathogens for humans, which can also be represented as innocuous bioinputs

Estado clínico-oncológico de pacientes incluidos en el ensayo clínico RANIDO tratados con Racotumomab o Nimotuzumab

Introduction: RANIDO is a clinical trial extended to primary health care with the objective of assessing the efficiency of Cuban biotechnology products Racotumomab and Nimotuzumab for the treatment of non-small cell lung cancer.Objective: to characterize the patients from the clinical and oncological assessments included in the RANIDO clinical trial treated with Racotumomab and Nimotuzumab in Pinar del Río between January 2013 and January 2018.Methods: observational, descriptive and cross-sectional study carried out at Raúl Sánchez Rodríguez University Polyclinic between 2013 and 2018. The target group comprised 33 patients, working with the totality of them. The information was collected from the clinical records. Descriptive statistical methods were applied.Results: male patients prevailed (63,6 %). The age group from 60 to 69 years old predominated (57,6 %). Adenocarcinoma (54,5 %) was the predominant histopathological type. Stage IIIB was the most frequent at diagnosis (54,5 %); the disease in progression was the response to the standard oncological treatment (48.5 %). Most patients survived between 12-17 months (42,4%); the overall survival rate was 18,6 months.Conclusions: a greater number of adults were found after the sixth decade of life and of the male sex; who were affected in greater percentage by epidermoid carcinoma and detected in advanced stages of the disease. With the immunotherapy, favorable results were obtained in the treatment of patients with advanced stages of the disease, which turned into an increase in their survival.Introducción: RANIDO es un ensayo clínico extendido hasta la atención primaria de salud con el objetivo de evaluar la eficacia de los productos biotecnológicos cubanos Racotumomab y Nimotuzumab para el tratamiento del cáncer de pulmón de células no pequeñas.Objetivo: caracterizar clínico-oncológicamente a los pacientes incluidos en el ensayo clínico RANIDO tratados con Racotumomab y Nimotuzumab en Pinar del Río entre enero de 2013 y enero de 2018.Métodos: estudio observacional, descriptivo y de corte transversal en el Policlínico Universitario “Raúl Sánchez Rodríguez” entre 2013 y 2018. El universo lo constituyeron 33 pacientes, trabajándose con la totalidad. La información fue extraída de las historias clínicas. Se emplearon métodos de estadística descriptiva.Resultados: el 63,6 % de los pacientes fueron del sexo masculino. Predominó el grupo etario de 60 a 69 años (57,6 %). El adenocarcinoma (54,5 %) fue el tipo histopatológico predominante. El estadio IIIB fue el más frecuente al diagnóstico (54,5 %); la enfermedad en progresión constituyó la respuesta al tratamiento oncoespecífico usual (48,5 %). La mayoría de los pacientes sobrevivieron entre 12 y 17 meses (42,4 %); la media de supervivencia global fue de 18,6 meses.Conclusiones: Se encontró mayor número de adultos pasados la sexta década de vida y del sexo masculino; afectados en mayor porciento por el carcinoma epidermoide y detectados en estadíos avanzados de la enfermedad. Con la inmunoterapia se obtuvieron resultados favorables en el tratamiento de los pacientes con estadios avanzados de la enfermedad, lo que se tradujo en un aumento de su supervivencia