Aprender a enseñar ciencias vinculando el museo como recurso didáctico para la enseñanza del sistema circulatorio humano

Esta investigación se centró en describir cómo aprende a enseñar ciencias una profesora de secundaria en formación continua, incorporando el Museo de Ciencias en la enseñanza del sistema circulatorio. A través de la clínica didáctica, se buscaron evidencias sobre las modificaciones en el estatus de sus ideas respecto a este recurso en el marco de su PCK, las cuales se interpretaron desde el cambio conceptual en relación con el papel regulador de la metacognición. Los resultados indican que la idea es inteligible y plausible en su discurso, destacando el potencial del museo para la enseñanza y el aprendizaje, pero la fructibilidad se alcanza cuando la profesora reflexiona sobre sus acciones, luego de ejecutar la unidad didáctica

Ampliando la perspectiva escolar : los museos como espacio de formación

Se presentan los resultados de un programa de formación continua con profesores en ejercicio que tuvo como centro de atención la utilización de los museos como herramienta pedagógica y didáctica. Cómo hipótesis de trabajo se plantea que el uso de los museos por parte de los docentes abre nuevas perspectivas referentes al ejercicio pedagógico y al mismo tiempo permite enriquecer el medio didáctico así como la producción de materiales de apoyo escolar. El programa se desarrolló con ocho profesores de educación básica y media e integro el trabajo de tres museos de ciencia de la ciudad de Medellín (Colombia)

¿Contribuyen los talleres en el Museo de Ciencias a fomentar actitudes hacia la conservación del ambiente?

Esta investigación se centró en evaluar el impacto de seis talleres sobre la adopción de actitudes deseables respecto a la conservación del ambiente y la sostenibilidad, por parte de distintos públicos visitantes de un Museo Interactivo. La metodología incluyó: a) el diseño de escalas con cuatro opciones de respuesta que se aplicaron antes y después del taller b) entrevistas telefónicas o visita a instituciones educativas, dos meses después de la visita al Museo. El análisis cuantitativo mostró que las actitudes de los participantes mejoraron en todos los talleres aunque no siempre fue estadísticamente significativo. El análisis cualitativo reveló que los participantes mostraron actitudes de compromiso y cuidado hacia el ambiente. Algunas estuvieron asociadas a los talleres y otras a actitudes desarrolladas con anterioridad al taller.This research focused on assessing the impact of six workshops on the adoption of desirable attitudes about environmental conservation and sustainability, of different group visitors of an interactive museum. The methodology included: a) the design of four-option scales that were applied before and after the workshop b) either telephone interviews or visits to schools, two months after the visit to the museum. The quantitative analysis showed that the attitudes of the participants improved in all the workshops but not all of them were statistically significant. The qualitative analysis revealed that participants demonstrated attitudes of commitment and care towards the environment. Some of these attitudes were associated with the workshops and other associated with attitudes developed prior to the workshop

Poverty, social exclusion and dental caries of 12-year-old children: a cross-sectional study in Lima, Peru

Background: Socioeconomic differences in oral health have been reported in many countries. Poverty and social exclusion are two commonly used indicators of socioeconomic position in Latin America. The aim of this study was to explore the associations of poverty and social exclusion with dental caries experience in 12-year-old children. Methods: Ninety families, with a child aged 12 years, were selected from 11 underserved communities in Lima (Peru), using a two-stage cluster sampling. Head of households were interviewed with regard to indicators of poverty and social exclusion and their children were clinically examined for dental caries. The associations of poverty and social exclusion with dental caries prevalence were tested in binary logistic regression models. Results: Among children in the sample, 84.5% lived in poor households and 30.0% in socially excluded families. Out of all the children, 83.3% had dental caries. Poverty and social exclusion were significantly associated with dental caries in the unadjusted models (p = 0.013 and 0.047 respectively). In the adjusted model, poverty remained significantly related to dental caries (p = 0.008), but the association between social exclusion and dental caries was no longer significant (p = 0.077). Children living in poor households were 2.25 times more likely to have dental caries (95% confidence interval: 1.24; 4.09), compared to those living in non-poor households. Conclusion: There was support for an association between poverty and dental caries, but not for an association between social exclusion and dental caries in these children. Some potential explanations for these findings are discussed

GABA-A Channel Subunit Expression in Human Glioma Correlates with Tumor Histology and Clinical Outcome

GABA (γ-aminobutyric acid) is the main inhibitory neurotransmitter in the CNS and is present in high concentrations in presynaptic terminals of neuronal cells. More recently, GABA has been ascribed a more widespread role in the control of cell proliferation during development where low concentrations of extrasynaptic GABA induce a tonic activation of GABA receptors. The GABA-A receptor consists of a ligand-gated chloride channel, formed by five subunits that are selected from 19 different subunit isoforms. The functional and pharmacological properties of the GABA-A channels are dictated by their subunit composition. Here we used qRT-PCR to compare mRNA levels of all 19 GABA-A channel subunits in samples of human glioma (n = 29) and peri-tumoral tissue (n = 5). All subunits except the ρ1 and ρ3 subunit were consistently detected. Lowest mRNA levels were found in glioblastoma compared to gliomas of lower malignancy, except for the θ subunit. The expression and cellular distribution of the α1, γ1, ρ2 and θ subunit proteins was investigated by immunohistochemistry on tissue microarrays containing 87 gliomas grade II. We found a strong co-expression of ρ2 and θ subunits in both astrocytomas (r = 0.86, p<0.0001) and oligodendroglial tumors (r = 0.66, p<0.0001). Kaplan-Meier analysis and Cox proportional hazards modeling to estimate the impact of GABA-A channel subunit expression on survival identified the ρ2 subunit (p = 0.043) but not the θ subunit (p = 0.64) as an independent predictor of improved survival in astrocytomas, together with established prognostic factors. Our data give support for the presence of distinct GABA-A channel subtypes in gliomas and provide the first link between specific composition of the A-channel and patient survival

Probiotic Sonicates Selectively Induce Mucosal Immune Cells Apoptosis through Ceramide Generation via Neutral Sphingomyelinase

This is an open-access article distributed under the terms of the Creative Commons Attribution License.-- et al.[Background]: Probiotics appear to be beneficial in inflammatory bowel disease, but their mechanism of action is incompletely understood. We investigated whether probiotic-derived sphingomyelinase mediates this beneficial effect. [Methodology/Principal Findings]: Neutral sphingomyelinase (NSMase) activity was measured in sonicates of the probiotic L. brevis (LB) and S. thermophilus (ST) and the non-probiotic E. coli (EC) and E. faecalis (EF). Lamina propria mononuclear cells (LPMC) were obtained from patients with Crohn's disease (CD) and Ulcerative Colitis (UC), and peripheral blood mononuclear cells (PBMC) from healthy volunteers, analysing LPMC and PBMC apoptosis susceptibility, reactive oxygen species (ROS) generation and JNK activation. In some experiments, sonicates were preincubated with GSH or GW4869, a specific NSMase inhibitor. NSMase activity of LB and ST was 10-fold that of EC and EF sonicates. LB and ST sonicates induced significantly more apoptosis of CD and UC than control LPMC, whereas EC and EF sonicates failed to induce apoptosis. Pre-stimulation with anti-CD3/CD28 induced a significant and time-dependent increase in LB-induced apoptosis of LPMC and PBMC. Exposure to LB sonicates resulted in JNK activation and ROS production by LPMC. NSMase activity of LB sonicates was completely abrogated by GW4869, causing a dose-dependent reduction of LB-induced apoptosis. LB and ST selectively induced immune cell apoptosis, an effect dependent on the degree of cell activation and mediated by bacterial NSMase. [Conclusions]: These results suggest that induction of immune cell apoptosis is a mechanism of action of some probiotics, and that NSMase-mediated ceramide generation contributes to the therapeutic effects of probiotics.The funding sources included grants from Centro de Investigación Biomédica en Red de Enfermedades Hepáticas y Digestivas (CIBERehd), Ministerio de Ciencia e Innovación (SAF2005-00280 and SAF2008-03676 to MS, FIS2009-00056 to AM, SAF2009-11417 to JCF), Fundación Ramón Areces (to MS), the National Institutes of Health (DK30399 and DK50984 to CF) and the Research Center for Liver and Pancreatic Diseases funded by the United States National Institute for Alcohol Abuse and Alcoholism (P50 AA 11999 to JCF).Peer reviewe

Structured models of cell migration incorporating molecular binding processes

The dynamic interplay between collective cell movement and the various molecules involved in the accompanying cell signalling mechanisms plays a crucial role in many biological processes including normal tissue development and pathological scenarios such as wound healing and cancer. Information about the various structures embedded within these processes allows a detailed exploration of the binding of molecular species to cell-surface receptors within the evolving cell population. In this paper we establish a general spatio-temporal-structural framework that enables the description of molecular binding to cell membranes coupled with the cell population dynamics. We first provide a general theoretical description for this approach and then illustrate it with two examples arising from cancer invasion