79 research outputs found

    Skill development in experimental courses

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    Experimental courses offer a good opportunity to work with competences, promoting the incorporation of strategies oriented towards motivating students to actively involve in the learning process, promoting reflexive learning and developing generic skills. This study presents different ways of developing and evaluating some important general skills, settle on four specific objectives: 1. To increase student motivation using samples of potential interest to students and explaining real-live application of their samples analyses; 2. To assist students' self-regulation and learning autonomy by using the portfolio; 3. To promote group work through experiments in pairs and small-group discussions; 4. To develop communication skills through small-group discussions and oral presentations. Results show that the type of sample used and real-life application has important influence on motivation. The portfolio is a good tool to promote reflection and to evaluate both specific and generic skills in experimental courses, the dynamics of a laboratory course permit students to develop their group-work and communicative skills, and peer evaluations both improve students' communication skills and promote metacognitive reflection. Finally, the project demonstrates that it is possible to train students in general skills using the specific course content and that the incorporation of participatory methodologies encourages students to become actively involved in the teaching-learning process

    Analysis of isotopes of plutonium in water samples with a PSresin based on aliquat⋅336

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    There is a necessity to have techniques capable to perform rapid determinations of specific radionuclides with the aim to provide fast response in emergency situations where a large number of samples need to be measured in a short time. Plastic Scintillation Resins (PSresins) raises as an adequate tool to achieve this purpose and in the present study a methodology to determine plutonium using a PSresin based on Aliquat·336 was developed. Different sample treatments have been studied under acidic conditions with an emphasis on valence adjustment treatment to achieve an effective retention within the PSresin. Under 3 M nitric acid conditions and an iron sulphamate (II) + nitrite valence adjustment, quantitative retention and 100% detection efficiency were achieved. The retention of the different interferences evaluated (238U, 230Th, 241Am, 210Pb and 99Tc) was low and therefore they do not interfere significantly in the determination of plutonium, except for 99Tc. Finally, a stable tracer to calculate the PSresin separation yield was studied, revealing that gold is suitable for this purpose. This procedure was applied to the analysis of spiked sea and river water samples, obtaining errors lower than 10% in their quantification

    PSresin for the analysis of alpha-emitting radionuclides: Comparison of diphosphonic acid-based extractants

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    The analysis of radionuclides is complex, with high economic and time costs. For this reason, there is a need to develop new methods and strategies to reduce these costs. One important group in the analysis of radionuclides is the actinides, which are the main constituents assessed in the total gross alpha together with radium and radon test used to measure radioactivity in drinking water. Moreover, in nuclear dismantling processes, the possible spread of the released radionuclides has to be controlled, which is measured by many techniques, depending on the radionuclides, through scintillation. This work presents a new method to analyse actinides using plastic scintillation resins (PSresins) packed in a solid-phase extraction cartridge. The proposed method combines chemical separation and sample measurement into a single step, reducing the effort, time and reagents required for analysis as well as decreasing the amount of waste generated. The PSresins compared in this study contained three selective extractants based on Methylenediphosphonic acid with different radicals, which has a high affinity for tri-, tetra-, and hexavalent actinides in dilute acids. These extractants were immobilised on plastic scintillation microspheres at a ratio of 1/1:6, producing a retention and detection efficiency of 100% for 241Am, 230Th, Uranium and 238Pu. The retention and detection efficiency were 20% and 100%, respectively, for 210Po and low for 226Ra

    Highly multiplexed immune profiling throughout adulthood reveals kinetics of lymphocyte infiltration in the aging mouse prostate

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    Aging is a significant risk factor for cancer in several tissues, including the prostate. Defining the kinetics of age-related changes in these tissues is critical for identifying regulators of aging and evaluating interventions to slow the aging process and reduce disease risk. An altered microenvironment is characteristic of prostatic aging in mice. Whether features of aging in the prostate emerge predominantly in old age or earlier in adulthood has not previously been established. Using comprehensive immune profiling and time-course analysis, we show that populations of T and B lymphocytes increase in the mouse prostate between 6 and 12 months of age. When comparing the prostate to other urogenital tissues, we found similar features of age-related inflammation in the mouse bladder. In summary, our study offers new insight into the kinetics of prostatic inflammaging and the window when interventions to slow down age-related changes may be most effective

    Highly multiplexed immune profiling throughout adulthood reveals kinetics of lymphocyte infiltration in the aging mouse prostate

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    Aging is a significant risk factor for cancer in several tissues, including the prostate. Defining the kinetics of age-related changes in these tissues is critical for identifying regulators of aging and evaluating interventions to slow the aging process and reduce disease risk. An altered microenvironment is characteristic of prostatic aging in mice. Whether features of aging in the prostate emerge predominantly in old age or earlier in adulthood has not previously been established. Using comprehensive immune profiling and time-course analysis, we show that populations of T and B lymphocytes increase in the mouse prostate between 6 and 12 months of age. When comparing the prostate to other urogenital tissues, we found similar features of age-related inflammation in the mouse bladder. In summary, our study offers new insight into the kinetics of prostatic inflammaging and the window when interventions to slow down age-related changes may be most effective

    Estrategia en el simulador de negocios Capstone para la empresa Baldwin

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    Este trabajo representa el trabajo de obtención de grado de los autores de este de la maestría en administración del ITESO a través del estudio de caso del simulador de negocios Capstone. El capítulo uno presenta el marco teórico que recoge información valiosa para la planeación estratégica de una compañía, diferentes tipos de liderazgo, situaciones complejas del mercado como la aparición de una pandemia y ejemplos prácticos mediante el análisis de casos de estudio. Durante el capítulo dos se tiene el primer acercamiento a la industria Capstone y sus características como el detalle del reporte Courier, Balanced Scorecard, reglas, estrategias genéricas y primer vistazo a la situación del mercado. También se utiliza para definir la estrategia de la compañía Baldwin y las acciones concretas a seguir durante la competencia. En los capítulos tres al seis se desarrolla un análisis de los resultados obtenidos por Baldwin en el periodo 2024 a 2031. Cada uno de ellos revisa un periodo de dos años de operaciones y presenta todas las decisiones tomadas por la mesa directiva evaluando efectividad y si deben continuar o no por ese camino mientras revisan a los competidores y las áreas de oportunidad que se pueden aprovechar. En el capítulo siete se encuentran las conclusiones generales de la competencia simulada, las materias de investigación y desarrollo y del posgrado. Cada integrante del equipo Baldwin considera que este documento es evidencia de los conocimientos y aprendizajes adquiridos durante su paso por la maestría de administración de empresas.ITESO, A.C

    Involvement of Mechanical Cues in the Migration of Cajal-Retzius Cells in the Marginal Zone During Neocortical Development

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    Emerging evidence points to coordinated action of chemical and mechanical cues during brain development. At early stages of neocortical development, angiogenic factors and chemokines such as CXCL12, ephrins, and semaphorins assume crucial roles in orchestrating neuronal migration and axon elongation of postmitotic neurons. Here we explore the intrinsic mechanical properties of the developing marginal zone of the pallium in the migratory pathways and brain distribution of the pioneer Cajal-Retzius cells. These neurons are generated in several proliferative regions in the developing brain (e.g., the cortical hem and the pallial subpallial boundary) and migrate tangentially in the preplate/marginal zone covering the upper portion of the developing cortex. These cells play crucial roles in correct neocortical layer formation by secreting several molecules such as Reelin. Our results indicate that the motogenic properties of Cajal-Retzius cells and their perinatal distribution in the marginal zone are modulated by both chemical and mechanical factors, by the specific mechanical properties of Cajal-Retzius cells, and by the differential stiffness of the migratory routes. Indeed, cells originating in the cortical hem display higher migratory capacities than those generated in the pallial subpallial boundary which may be involved in the differential distribution of these cells in the dorsal-lateral axis in the developing marginal zone

    Flora y vegetación de suelos crioturbados y hábitats asociados en los alrededores del abra Apacheta, Ayacucho - Huancavelica (Perú)

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    around Abra Apacheta, in Cangallo (Ayacucho) and Huaytara (Huancavelica) Provinces. The aims of this study were: to study vascular floristic composition of High Andes (over 4500 m of altitude) and characterize highland vegetation. There were used conventional techniques for botanical collection and vegetation coverage measurements by intersection-line transects and Point Quadrat modifyed method. There were registered 134 species of vascular plants (Pteridophytes, Gymnospems, Eudicots and Monocots) grouped in 60 genera and 23 families. Eudicots were the dominant group with 74% of the total registered, 82% in genera and 77% in species; followed by Monocots with 13%, 13% and 21% in the previous categories. Monilophytes (ferns) were poorly represented by two families (9%), two genera (3%) and two species (1%); while Gymnosperms only registered one specie (Ephedra rupestris Benth.). By the quantitative analysis three types of plant communities associated to cryoturbated soils were characterized, we also report two types of associated vegetation: grasslands and rocky areas.Se presentan los resultados del estudio de la flora y vegetación de suelos crioturbados y hábitats asociados realizados en la zona del Abra Apacheta, en las provincias de Cangallo (Ayacucho) y Huaytará (Huancavelica). Los objetivos fueron: estudiar la composición de la flora vascular de los altos Andes (por encima de los 4500 m de altitud) y caracterizar la vegetación altoandina. Se aplicaron técnicas convencionales de colecta botánica, así como evaluaciones de la cobertura vegetal mediante transectos. Se registraron 134 especies de plantas vasculares agrupadas en 60 géneros y 23 familias. Las eudicotiledóneas son el grupo dominante con el 74% del total de familias reportadas, 82% en géneros y 77% en especies; seguido por las monocotiledóneas (13% de las familias, 13% de los géneros y 21% de las especies). Los monilófitos (helechos) están representados por dos familias (9%), dos géneros (3%) y dos especies (1%); mientras que para las gimnospermas se registra una sola especie (Ephedra rupestris Benth.). Tres tipos de comunidades en suelos crioturbados fueron caracterizadas y es reportada la presencia de dos tipos de vegetación asociada: pajonales y vegetación de roquedales

    Study and characterization of global solar radiation and incident UV in the city of Leon, Guanajuato, Mexico

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    Controlled sun exposure can greatly benefit vitamin D synthesis, however, irresponsible sun exposure can cause considerable biological damage. Among the extraterrestrial solar radiation that reaches the earth's surface, UV rays are characterized by having the shortest wavelengths (less than 400 nm) and the highest frequencies, which is why they concentrate a large amount of energy. In particular, radiation with wavelengths less than 300 nm can alter DNA molecules and cause biological damage such as skin changes, cataracts, possible mutations, immunosuppression, photoaging and many other conditions. Therefore, this research estimates the global solar radiation and the incident daily UV radiation, as well as the UV index in order to identify the possible dose of absorbed radiation and consequently identify the relevant protection actions for the local population
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