122 research outputs found
Las desigualdades de la escuela y del entorno
La ponencia revisa la forma en que las carencias del entorno social y familiar de los alumnos se combinan con las de las escuelas, conformando un círculo perverso de inequidad. Se utilizan como conceptos clave –ordenadores del conjunto de aspectos analizados- los de demanda y oferta educativas.
Para mostrar la relación a que alude el objetivo, se analizan datos provenientes de los estudios sobre resultados de aprendizaje y factores asociados realizados por el Instituto Nacional para la Evaluación de la Educación (INEE) en 2005 y 2006, así como indicadores sobre recursos materiales de las escuelas primarias y secundarias del país, abordados en otros estudios del propio Instituto.
Aunque la ponencia no se inscribe propiamente en el marco de estudios sobre eficacia escolar o factores asociados, aborda una problemática sensible desde una perspectiva de política basada en dichos campos de investigación: la falta de equidad con que se distribuyen los recursos educativos que lejos de compensar las desigualdades en cuanto al origen social de los educandos, las refuerza en su efecto sobre el logro escolar
GESTIÓN DEL AGUA EN UNA UNIDAD HABITACIONAL TRADICIONAL EN CUERNAVACA, MORELOS
Este trabajo toma como punto de partida el inicio de las unidades habitacionales de alta densidad, de interés social, que fueron edificadas en los 80s y 90s en Cuernavaca, Morelos. Actualmente se registran 11 unidades habitacionales tradicionales, las cuales estuvieron acompañadas de obras de equipamiento urbano y servicios públicos municipales, a fin de que estas fueran funcionales durante su periodo de vida. Sin embargo, en la actualidad las viviendas de estas unidades presentan entre otros problemas, la reducción en el acceso al agua potable. Por ello, el objetivo de esta investigación es mostrar de manera exploratoria los retos a los que se enfrenta una de las unidades habitacionales tradicionales en la gestión del agua a nivel interno. La información se obtuvo a través de documentos de la unidad habitacional, por observación participante y entrevista abierta a condóminos. En el análisis de la información se utilizó la técnica del árbol de problemas y la elaboración de tablas y gráficas. Los resultados obtenidos muestran como principales problemas de la gestión del agua, la insuficiente cantidad del vital líquido para uso doméstico a disposición de los condóminos, derivado de la reducción del tiempo de bombeo del agua hacia los departamentos con la finalidad de disminuir los costos de energía eléctrica, esta situación origina inconformidad en los usuarios quienes por un lado dejan de pagar su cuota por concepto de mantenimiento de servicios generales o abandonan su departamento lo que conlleva al decremento en la captación de ingresos destinados al funcionamiento de la unidad habitacional. Lo anterior refleja la necesidad de una planeación urbana sostenible donde exista una corresponsabilidad entre autoridades municipales, estatales, federales y condóminos que faciliten una gestión del agua desde un enfoque más integral en beneficio de la sociedad como lo pretenden los objetivos del desarrollo sostenible al 2030
Implementación de una estrategia de marketing digital en una MiPyME del sector comercio en Campeche y su impacto en ventas
El comercio electrónico es una plataforma amplia de negocio que puede ser adaptada a cualquier empresa. Actualmente la evolución de transacciones a través de este modelo de negocio ha ido en aumento en los últimos años. En México, según datos de la Asociación Mexicana de Venta Online, el comercio electrónico incrementó en 2020 un 81% en comparación al año anterior. Algunos de los beneficios del e-commerce para las empresas son la mejora de procesos organizacionales hasta la exploración de una ventaja competitiva. Es importante señalar que incursionar en este tipo de plataformas no es exclusivo para grandes empresas, las MiPyMEs pueden acceder a los beneficios del e-commerce sin necesidad de grandes inversiones, el abanico de opciones es amplio y las ventajas de implementación puede resultar muy redituable para el desarrollo de la organización. La presente investigación tiene como finalidad presentar los resultados de la implementación del comercio electrónico en una MiPyME del sector comercio, ubicada en la ciudad de San Francisco de Campeche, Campeche, México
The validity of incremental exercise testing in discriminating of physiological profiles in elite runners
The goal of this study was to determine whether traditional ergoespirometric incremental exercise testing carried out to the point of exhaustion could be useful in distinguishing the physiological profiles of elite runners that compete in races that lasted about 8 minutes versus those that lasted about 2 hours. Ten male marathon runners (performance time: 2:12:04, coefficient of variation (CV) = 2.33%) and 8 male 3000 m steeplechase runners (performance time: 8:37.83, CV = 2.12%) performed an incremental test on the treadmill (starting speed 10 km. h–1; increments, 2 km. h–1; increment duration, 3 min to exhaustion). Heart rate (HR), VO2 , and lactate concentrations were measured at the end of each exercise level. At maximal effort, there were no differences between the groups regarding VO2max and maximal HR; however, the workload time, vVO2max and peak treadmill velocity were significantly higher in the 3000m steeplechase group (p<0.05). At submaximal effort, there were no significant differences between groups for VO2
(ml.kg–1.min–1), HR, or lactate. Our results show that this type of testing was not sufficient for discriminating the physiological profiles of elite runners who competed in middle-distance versus long-distance events (e.g. in the marathon and the 3000 m steeplechase
Design, implementation, and validation of a piezoelectric device to study the effects of dynamic mechanical stimulation on cell proliferation, migration and morphology
Cell functions and behavior are regulated not only by soluble (biochemical) signals but also by biophysical and mechanical cues within the cells’ microenvironment. Thanks to the dynamical and complex cell machinery, cells are genuine and effective mechanotransducers translating mechanical stimuli into biochemical signals, which eventually alter multiple aspects of their own homeostasis. Given the dominant and classic biochemical-based views to explain biological processes, it could be challenging to elucidate the key role that mechanical parameters such as vibration, frequency, and force play in biology. Gaining a better understanding of how mechanical stimuli (and their mechanical parameters associated) affect biological outcomes relies partially on the availability of experimental tools that may allow researchers to alter mechanically the cell’s microenvironment and observe cell responses. Here, we introduce a new device to study in vitro responses of cells to dynamic mechanical stimulation using a piezoelectric membrane. Using this device, we can flexibly change the parameters of the dynamic mechanical stimulation (frequency, amplitude, and duration of the stimuli), which increases the possibility to study the cell behavior under different mechanical excitations. We report on the design and implementation of such device and the characterization of its dynamic mechanical properties. By using this device, we have performed a preliminary study on the effect of dynamic mechanical stimulation in a cell monolayer of an epidermal cell line (HaCaT) studying the effects of 1 Hz and 80 Hz excitation frequencies (in the dynamic stimuli) on HaCaT cell migration, proliferation, and morphology. Our preliminary results indicate that the response of HaCaT is dependent on the frequency of stimulation. The device is economic, easily replicated in other laboratories and can support research for a better understanding of mechanisms mediating cellular mechanotransduction.Peer ReviewedPostprint (published version
Decolorization and detoxification of synthetic dyes by mexican strains of trametes sp
Laccases have attracted a great deal of interest because of their remarkable ability for the degradation of synthetic dyes present in wastewaters. New laccase producing sources with robust operational and functional properties are being continuously explored. In this work, the potential for the decolorization and detoxification of synthetic dyes was evaluated in two Mexican strains of the genus Trametes. The decolorization capacity of Trametes maxima LE130 and Trametes sp. LA1 was tested in solid and liquid media. The phytotoxicity of the degradation products was determined using Raphanus sativus and Pisum sativum seeds. In solid media, both strains showed a higher decolorization capacity (p ≤ 0.05) than Phanerochaete chrysosporium ATCC 24725, which is known to be very efficient in lignin and dye-degradation. They produced laccase as the main ligninolytic enzyme; T. maxima LE130 secreted a single isoform of 43.9 kDa, while Trametes sp. LA1 produced three isoforms of 67.3, 58.6 and 52.7 kDa, respectively. Trametes sp. LA1 culture fluids were capable of decolorizing and detoxifying chemically diverse dyes (anthraquinonic dye Remazol Brilliant Blue R, azoic Reactive Black 5 and triphenylmethane Crystal Violet) without the addition of redox mediators. Therefore, this could be considered as a new laccase source which could be potentially competitive in the bioremediation of dye-containing wastewaters.Fil: Levin, Laura Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Micología y Botánica. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Micología y Botánica; ArgentinaFil: Hernández Luna, Carlos E.. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Niño Medina, Guillermo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: García Rodríguez, Juan Pablo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: López Sadin, Iosvany. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Méndez Zamora, Gerardo. Universidad Autonoma de Nuevo Leon.; MéxicoFil: Gutiérrez Soto, Guadalupe. Universidad Autonoma de Nuevo Leon.; Méxic
Estudo piloto em cuidadores de pacientes com enfermidades neurológicas, sobre o significado e conhecimento de cuidados paliativos
Aim. To describe the meaning attributed to palliative care (PC) by caregivers, as well as their preference with respect to informing the patient and their satisfaction in their caring role. Methodology: Study descriptive transversal, sample intended of 40 caregivers of neurologic patients needing PC. A questionnaire about knowledge of the topic and their burnout status was applied. A descriptive-comparative analysis was carried out with 95% (pObjetivo. Describir el significado que atribuyen cuidadores a los cuidados paliativos (CPS), así como su preferencia respecto a informar al paciente y su satisfacción con el papel de cuidador. Metodología. Estudio descriptivo transversal, muestra intencional de 40 cuidadores de enfermos neurológicos con necesidad de CPS. Se aplicó un cuestionario de conocimientos sobre el tema y sobrecarga. Se realizó análisis descriptivo-comparativo con un intervalo de confianza de 95% (pObjetivo. Descrever o significado que atribuem cuidadores aos cuidados paliativos (CPS), assim como sua preferência com respeito a informar ao paciente e sua satisfação com o papel de cuidador. Metodologia. Estudo descritivo transversal, amostra intencional de 40 cuidadores de enfermos neurológicos com necessidade de CPS. Aplicou-se um questionário de conhecimentos sobre o tema e sobrecarga. Realizou-se análise descritivo-comparativa com um intervalo de confiança de 95%
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Fructose transporter Glut5 expression in clear renal cell carcinoma
[Abstract] Renal cell carcinomas (RCC) can be subclassified for general purposes into clear cell, papillary cell, chromophobe cell carcinomas and oncocytomas. Other tumours such as collecting duct, medullary, mucinous tubular and spindle cell and associated with Xp 11.2 translocations/TFE 3 gene fusion, are much less common. There is also a residual group of unclassified cases. Previous studies have shown that RCC has high glycolytic rates, and expresses GLUT transporters, but no distinction has been made among the different subtypes of renal cell tumours and their grades of malignancy. In clear renal cell carcinoma (cRCC) glycogen levels increase, glycolysis is activated and gluconeogenesis is reduced. The clear cell subtype of RCC is characterized histologically by a distinctive pale, glassy cytoplasm and this appearance of cRCC is due to abnormalities in carbohydrate and lipid metabolism, and this abnormality results in glycogen and sterol storage. Several isoforms of glucose carriers (GLUTs) have been identified. We show here in a panel of 80 cRCC samples a significant correlation between isoform 5 (GLUT5) and many pathological parameters such as grade of differentiation, pelvis invasion and breaking capsule. GLUT5 expression also appears to associate more strongly with the clear cell RCC subtype. These data suggest a role for the GLUT5 isoform in fructose uptake that takes place in cRCC cells and which subsequently leads to the malignant RCC progression
Zn supported on Zr modified mesoporous SBA-15 as sorbents of pollutant precursors contained in fossil fuels: Si/Zr ratio effect
The adsption processes have become an additional alternative to hydrotreatment processes of oilderived
middle distillates. The crucial point is the type of adsorbent employed. SBA-15 mesoporous materials were used to adsorb quinoline (Q) and dibenzothiophene (DBT) as N- and S-containing model species, espectively, contained in a model mixture mimicking middle distillates. Q and DBT in dodecane solutions (50-250 ppm and 500 ppm, respectively) were used to that end. In order to improve the adsorption properties, SBA-15 was modified, incorporating zirconium at Si/Zr weight ratios of 5, 16, 60, and 150. At those ratios, Q was adsorbed preferably, whereas DBT was removed only below 10%. To increase the amount of S dsorbed, Zn was incorporated at 2 wt. %. At 250 ppm (sol. concentration) of N, the amount adsorbed of Q and DBT on the material without Zn (Si/Zr=5) was 1.51 and 0.02 mmolgads -1, respectively. The results were notably different when Zn was incorporated in adsorbents. In these case, amounts of adsorbed Q and DBT were 2.2 and 1.3 mmolgads -1, respectively, showing that metal sites are essential to adsorb DBT
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