Un nuevo modo de proceder en el aula aprendiendo mediante el ordenador

El presente estudio analiza la eficacia del aprendizaje mediante ordenador (AMO) en cuarto y quinto de EGB, aplicado en un contexto didáctico en el que se enfrenta directamente al alumno con el reto de aprender a través de su propia acción, frente a la utilización convencional de la enseñanza asistida por ordenador (CAI), concebida — habitualmente — como complemento para reforzar la enseñanza el profesor. El software empleado en este estudio es del tipo drill and practice sobre el sistema métrico decimal, pero utilizado con anterioridad a las explicaciones del profesor. Se ha utilizado un diseño pretest-postest con cinco grupos de quinto de EGB (N = 148) y tres de cuarto de EGB (N = 72). El análisis de covarianza mostró la eficacia diferencial de los tratamientos, revelándose la combinación del AMO y la clase convencional como la estrategia más efectiva respecto al aprendizaje de los alumnos. Por la peculiar utilización de los programas se pone de manifiesto la potencialidad de un enfoque de carácter más inductivo, que abre nuevas posibilidades para el desarrollo del proceso de aprendizaje en el aula, reconduciendo el rol del profesor y realzando el protagonismo del alumno en su propio aprendizaje

Anomalous ordering in inhomogeneously strained materials

We study a continuous quasi-two-dimensional order-disorder phase transition that occurs in a simple model of a material that is inhomogeneously strained due to the presence of dislocation lines. Performing Monte Carlo simulations of different system sizes and using finite size scaling, we measure critical exponents describing the transition of beta=0.18\pm0.02, gamma=1.0\pm0.1, and alpha=0.10\pm0.02. Comparable exponents have been reported in a variety of physical systems. These systems undergo a range of different types of phase transitions, including structural transitions, exciton percolation, and magnetic ordering. In particular, similar exponents have been found to describe the development of magnetic order at the onset of the pseudogap transition in high-temperature superconductors. Their common universal critical exponents suggest that the essential physics of the transition in all of these physical systems is the same as in our model. We argue that the nature of the transition in our model is related to surface transitions, although our model has no free surface.Comment: 5 pages, 3 figure

A review on the potential of aquaculture development in Kenya for poverty alleviation and food security

On the global scene, aquaculture accounts for about 50% of total fish production amounting to about 80 million metric tonnes. It is estimated that another 40 million metric tonnes of aquatic food will be required by the year 2030. Today, fish farming represents the fastest growing sector of food production. Moreover, aquaculture has a major role to play in the achievement of the first three Sustainable Development Goals on poverty, hunger, food security and healthy lives of people from developing countries. This is significant especially in the developing countries where poverty and malnutrition are a reality. However, in sub-Saharan Africa, per capita fish production from aquaculture is still below world production levels. In Kenya, inland capture fisheries accounted for over 90% of the total national fish production while marine capture fisheries contributed about 5% in the last decade. Kenya has one of the fastest growing human populations in the world indicating that the demand for fish and fish products will continue to rise, increasing the gap between supply and demand. Currently, aquaculture only produces about 24,000 metric tonnes of fish annually compared to an annual average of 178,000 metric tonnes from natural fisheries. The dominant cultured species include: Nile tilapia (Oreochromis niloticus), African catfish (Clarias gariepinus), rainbow trout (Onchorhynchus mykis) and common carp (Cyprinus carpio). Culture systems commonly used are static ponds and raceway systems. In addition, the country is endowed with numerous aquaculture resources ranging from favorable climatic conditions to vast water resources. In the year 2009, the Kenyan government took steps to enhance aquaculture production through an Economic Stimulus Programme. This has increased the contribution of aquaculture in Kenya to 11.0% of the total fish production. This paper discusses the growth and development of aquaculture in Kenya during the last 50 years and the impact of government support to the sub-sector. The paper also proposes strategies for ensuring that Kenya becomes one of the leading producers of fish from aquaculture in Africa.Key words: Fish production, capture fisheries, culture systems, Economic Stimulus Programme, aquacultur

La Generación Interactiva frente a un nuevo escenario de comunicación. Retos sociales y educativos

A lo largo de los últimos años se ha configurado un escenario de comunicación al que niños y jóvenes se han adaptado rápidamente. Por este motivo, surge en nuestra sociedad el reto de averiguar las fórmulas de protección y educación más adecuadas para evitar que los menores naufraguen en este nuevo entorno, así como formular las oportunas reflexiones que ayuden en esta tarea a sus padres y responsables para alcanzar un uso y consumo responsable de las pantallas audiovisuales (televisión, teléfonos móviles, Internet y videojuegos). El Consejo Audiovisual de Navarra (CoAN), con este estudio y otras iniciativas –entre las que destaca la campaña de alfabetización mediática “Familia y Pantallas Audiovisuales”–, dirige sus esfuerzos hacia la defensa de los intereses legítimos de los usuarios de los medios de comunicación audiovisual y, muy especialmente, los intereses de los menores para preservar su correcto desarrollo físico, mental y moral

Health implications of an immigration raid: findings from a Latino community in the midwestern United States.

Immigration raids exemplify the reach of immigration law enforcement into the lives of Latino community members, yet little research characterizes the health effects of these raids. We examined the health implications of an immigration raid that resulted in multiple arrests and deportations and occurred midway through a community survey of a Latino population. We used linear regression following principal axis factoring to examine the influence of raid timing on immigration enforcement stress and self-rated health. We controlled for age, sex, relationship status, years in the county in which the raid occurred, children in the home, and nativity. 325 participants completed the survey before the raid and 151 after. Completing the survey after the raid was associated with higher levels of immigration enforcement stress and lower self-rated health scores. Findings indicate the negative impact of immigration raids on Latino communities. Immigration discussions should include holistic assessments of health.UL1 TR000433 - NCATS NIH HH

Menores y redes ¿sociales?: de la amistad al cyberbullying

En el siguiente trabajo se estudian cuatro cuestiones relacionadas con el fenómeno de las redes sociales y el acoso digital, a través de los datos obtenidos por el proyecto Generaciones Interactivas, que entre marzo y junio de 2009 encuestó en España a 13.000 menores de entre 6 y 18 años: ¿Es el acceso a Internet determinante a la hora de estar expuesto a recibir agresiones virtuales? ¿Facilita el acceso el desarrollo de conductas negativas de agresión a terceros? ¿Qué papel juegan el género y la edad en esta realidad de víctimas y agresores? Las redes sociales, tan populares entre este grupo de edad, ¿constituyen un caldo de cultivo para este tipo de prácticas

La educación sexual en los textos escolares españoles: evaluación de un texto alternativo

Junto al aumento de la utilización de preservativos, asistimos también al aumento de la transmisión de infecciones de transmisión sexual, al adelanto en la edad de inicio de relaciones sexuales y al aumento de embarazos en adolescentes. En este sentido cobra especial importancia la educación sexual recibida en el último tramo de la educación obligatoria. Es importante, desde el punto de vista de la Salud Pública, desarrollar contenidos que permitan al alumno adquirir habilidades sociales que le ayuden a tomar decisiones más libres e informadas encaminadas a retrasar el inicio de las relaciones sexuales. En este trabajo se presentan los resultados de la evaluación comparativa sobre los contenidos de los libros escolares del área de Biología de 3º de la ESO en su capítulo sobre sexualidad y reproducción humana con un texto escolar alternativo. Se evalúa si posibilitan la consecución de los objetivos educativos señalados en el currículo y si promocionan estilos de vida saludables que lleguen a prevenir conductas de riesgo. ------------------------Together with the increase of condom use, the spread of sexually transmitted infections, earlier ages of sexual debut and pregnancies in teenagers are also increasing. Sexual education in schools plays an important role. It is therefore important, from a public health point of view, to develop materials with contents that can help students acquire the life skills that will enable them to make free and informed decisions concerning sexuality. In this study the results of a comparative evaluation of different school texts with an alternative we have elaborated for the area of sexuality and human reproduction are presented. The extent to which these books achieve official educational objectives, promote healthy life styles and convey information enabling the prevention of risky sexual behaviours was evaluated

Cyberbullying: un análisis comparativo en estudiantes de Argentina, Brasil, Chile, Colombia, México, Perú y Venezuela

This study explores the issue of cyberbullying from a cross-cultural perspective. The focus is on the examination of the extent of Argentina, Brazil, Chile, Colombia, México, Peru, Venezuela tweens and adolescents’ experiences of cyberbullying. A survey study of 21.000 students from 10 to 18 years. In this paper, “cyberbullying” refers to bullying via electronic communication tools: mobile phone/video/picture/text message, Internet/gaming/instant messaging

Permissive expansion and homing of adoptively transferred T cells in tumor-bearing hosts

Activated T cells expressing endogenous or transduced TCRs are two cell types currently used in clinical adoptive T-cell therapy. The ability of these cells to recognize their antigen, expand, and traffic to the tumor site are the initial steps necessary for successful therapy. In this study, we used in vivo bioluminescent imaging (BLI) of Renilla luciferase (RLuc) expressing T cells to evaluate the ability of adoptively transferred T cells to survive, expand and home to tumor site in vivo. Using this method, termed RT-Rack (Rluc T cell tracking), we followed T-cell response against tumors in vivo. Expansion and homing of adoptively transferred T cells were antigen dependent, but independent of the host immune status. Moreover, we successfully detected T-cell response to small and large tumors, including autochthonous liver tumors. The adoptively transferred T cells were not ignorant or excluded in a partially tolerant host, which expressed low level of the target in the periphery. Using T cell receptor-engineered T cells, we showed the ability of these cells to respond in tumor-bearing hosts by expanding and homing to the tumor site. In all these models, the host immune status, the nature of the tumor or of the antigen, the tumor size, and the presence of the targeted antigen in the periphery did not prevent the adoptively transferred T cells from responding by expanding and homing to the tumor. However, T cells had higher expression of the inhibitory receptor PD1 and reduced functional activity when a self-antigen was targeted

Depth-dependent critical behavior in V2H

Using X-ray diffuse scattering, we investigate the critical behavior of an order-disorder phase transition in a defective "skin-layer" of V2H. In the skin-layer, there exist walls of dislocation lines oriented normal to the surface. The density of dislocation lines within a wall decreases continuously with depth. We find that, because of this inhomogeneous distribution of defects, the transition effectively occurs at a depth-dependent local critical temperature. A depth-dependent scaling law is proposed to describe the corresponding critical ordering behavior.Comment: 5 pages, 4 figure