299 research outputs found
Construyendo dominios de encuentro para problematizar acerca de las prácticas pedagógicas de profesores secundarios de Ciencias: Incorporando el modelo de Investigación-Acción como plan de formación continua
Frente a la actual crisis de la educación científica, la capacidad docente de transformar sus prácticas para mejorar el logro de aprendizajes parece ser fundamental. Los programas de formación docente continua tradicionales, generalmente prescriptivos y descontextualizados del aula, han tenido bajo impacto en los procesos de transformación de las prácticas docentes. El presente trabajo describe la primera fase de un programa de formación continua consistente en la construcción de dominios de encuentro entre el saber académico generado en la Universidad y el saber profesional de 16 profesores secundarios de Ciencias a través de un proceso de investigación-acción conjunta, basado en el trabajo colaborativo, la reflexión y la retroalimentación. Los resultados dan cuenta de la complejidad de generar significados comunes, los que una vez logrados, permiten fortalecer el razonamiento científico, la autoeficacia y conformación de una comunidad de aprendizaje que posibilita una actitud indagatoria hacia sus prácticas en Ciencias. / Considering the current scientific education crisis, teachers' capacity to transform their practice in order to improve learning achievement seems fundamental. The traditional programs of continuous professional development, generally prescriptive and uncontextualized from the classroom, have had a low impact on processes of teachers' practice transformation. This work describes the first stage of continuous development program, consisting on building encounter domains between the academic knowledge of Universities, and professional knowledge of 16 secondary science teachers, through a joint action-research process, based on collaborative work, reflection and feedback. The results show the complexity of building shared sense which, once achieved, allows strong scientific reasoning, self-efficacy and the construction of a learning community facilitating an inquiry-driven attitude towards their science teaching practice
Role of toxin activation on binding and pore formation activity of the Bacillus thuringiensis Cry3 toxins in membranes of Leptinotarsa decemlineata (Say)
AbstractBinding and pore formation constitute key steps in the mode of action of Bacillus thuringiensis δ-endotoxins.In this work, we present a comparative analysis of toxin-binding capacities of proteolytically processed Cry3A, Cry3B and Cry3C toxins to brush border membranes (BBMV) of the Colorado potato beetle Leptinotarsa decemlineata (CPB), a major potato coleopteran-insect pest. Competition experiments showed that the three Cry3 proteolytically activated toxins share a common binding site. Also heterologous competition experiments showed that Cry3Aa and Cry3Ca toxins have an extra binding site that is not shared with Cry3Ba toxin. The pore formation activity of the three different Cry3 toxins is analysed. High pore-formation activities were observed in Cry3 toxins obtained by proteolytical activation with CPB BBMV in contrast to toxins activated with either trypsin or chymotrypsin proteases. The pore-formation activity correlated with the formation of soluble oligomeric structures. Our data support that, similarly to the Cry1A toxins, the Cry3 oligomer is formed after receptor binding and before membrane insertion, forming a pre-pore structure that is insertion-competent
Refractory Thrombocytopenia Responds to Octreotide Treatment in a Case of Evans Syndrome with Gastric Neuroendocrine Tumor
A 37-year-old woman with history of Evans Syndrome with poor response to high-dose corticoid treatment presented to the emergency department with gastrointestinal and vaginal bleeding. The patient was later diagnosed with severe thrombocytopenia and a stage G1, well-differentiated gastric neuroendocrine tumor, confirmed by a biopsy. A total gastrectomy was performed to eradicate the tumor. After being treated with a total splenectomy for her Evans Syndrome with no clinical or laboratory improvement, she began regular treatment with octreotide on the basis of a possible hepatic metastasis. Days after the initiation of the octreotide, an increase in the platelet count was evidenced by laboratory findings, from 2,000 platelets/mm3 to 109,000 platelets/mm3 . Weeks later, the hepatic metastasis is discarded by a negative octreotide-body scan, and the octreotide treatment was interrupted. Immediately after the drug interruption, a progressive and evident descent in the platelet count was evidenced (4000 platelets/mm3 ). The present case report highlights the possible association between octreotide treatment and a severe thrombocytopenia resistant to conventional treatment.Revisión por pare
A Jasmonate-Inducible Defense Trait Transferred from Wild into Cultivated Tomato Establishes Increased Whitefly Resistance and Reduced Viral Disease Incidence
Early Risk Factors for Obesity in the First 1000 Days-Relationship with Body Fat and BMI at 2 Years
Background: Obesity is defined as an excessive accumulation of body fat. Several early developmental factors have been identified which are associated with an increased risk of childhood obesity and increased adiposity in childhood. The primary objective of the present study is to analyse the effect of various early risk factors on Body Mass Index (BMI) and body fat percentage at 2 years of age. (2) Methods: A prospective cohort study design was used, with the sample consisting of 109 mother-child pairs from whom data were collected between early pregnancy and 2 years old. Adiposity was determined based on skinfold measurements using the Brooks and Siri formulae. Mean comparison tests (Student's t-test and ANOVAs) and multiple linear regression models were used to analyse the relationship between early programming factors and dependent variables. (3) Results: Maternal excess weight during early pregnancy (beta = 0.203, p = 0.026), gestational smoking (beta = 0.192, p = 0.036), and accelerated weight gain in the first 2 years (beta = - 0.269, p = 0.004) were significantly associated with high body fat percentage. Pre-pregnancy BMI and accelerated weight gain in the first 2 years were associated with high BMI z-score (beta = 0.174, p = 0.047 and beta = 0.417, p = 0.000 respectively). The cumulative effect of these variables resulted in high values compared to the baseline zero-factor group, with significant differences in BMI z-score (F = 8.640, p = 0.000) and body fat percentage (F = 5.402, p = 0.002) when three factors were present. (4) Conclusions: The presence of several early risk factors related to obesity in infancy was significantly associated with higher BMI z-score and body fat percentage at 2 years of age. The presence of more than one of these variables was also associated with higher adiposity at 2 years of age. Early prevention strategies should address as many of these factors as possible.This study was supported by public funds, the ITI call (integrated territorial investment), developed by the Health Department of the Andalusian Government. The project has been 80% co-financed by funds from the FEDER operational program of Andalusia 2014-2020.
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Impact of public preventive programmes on oral quality of life of 11 to 12-yr-old school students
Objetivos: El objetivo es analizar el impacto de programas preventivos sobre la calidad de vida oral en escolares de 11- 12 años. Diseño del estudio: En el curso académico 1996/97 se inició un estudio quasiexperimental en la provincia de Granada con cuatro grupos de escolares de 6-7 años de edad: Sellador + Flúor (selladores en primeros molares permanentes aplicados en el centro de salud, durante 3 años de programa activo, y barniz de flúor aplicado cuatrimestralmente durante 3 años, n=65), Sellador (sólo selladores, n=80), Flúor (sólo barniz de flúor, n=107) y grupo Control (n=59). Todos los escolares fueron explorados cada 6 meses en los colegios durante los 3 años de programa activo, entregándoseles un informe de salud oral tras cada exploración. Tras un periodo de discontinuidad de 2.5 años, en el curso escolar 2002/03 (a los 5.5 años), los escolares fueron explorados, y se les pasó un cuestionario de calidad de vida oral, cuya puntuación va de -6 (mínima) a +6 (máxima). Resultados: Los valores de calidad de vida oral (± desviación estándar) fueron: 3.31±0.30 (Sellador + Flúor), 3.11±0.27 (Sellador), 3.18±0.23 (Flúor) y 2.95±0.32 (Control), sin diferencias estadísticamente significativas entre ellos. Conclusiones: Los programas de Sellador de fisuras y Barniz de flúor no muestran influencia significativa sobre la calidad de vida oral a 5.5 años de seguimiento (3 años de programa activo y 2.5 años de discontinuidad)
Interventions in the first 1000 days to prevent childhood obesity: a systematic review and quantitative content analysis
Background: Childhood obesity poses a global health challenge. In recent years, there has been an increase in interventions that begin in pregnancy, putting the concept of early programming and early risk factors into practice. The present study aims to update the findings regarding interventions in the first 1000 days of life. Methods: A systematic review based on the PRISMA guidelines was carried out in PubMed, WoS, Scopus and CINAHL to obtain the articles to be analysed. We included those studies published between 2016 and 2021. Human interventions that started within the first 1000 days of life and acted on at least one programming factor were included. Once selected, coding and quantitative content analysis was carried out to obtain a profile of the interventions during the first 1000 days. Results: From all screened articles, 51 unique interventions, which met the selection criteria, were included. The majority of interventions (81%) took place in high-income areas. Almost all (86%) were targeted at the general population. The majority (54%) started in the second trimester of pregnancy. A clear majority (61%) ended at the time of birth. 44% of the interventions included all pregnant women. Only 48% of these interventions were focused on improving the nutritional status of the offspring in the short term. Most interventions collected the baby's weight at birth (68%). Conclusions: It can be concluded that current interventions are not covering as many aspects as they should. Future research should be conducted more frequently in developing countries and target disadvantaged groups. These interventions should include all pregnant women, regardless of their nutritional status, aiming to cover as many programming factors as possible and extending through the first 1000 days of life, with body mass index or skinfolds as measures of effectiveness during this period.11 página
Cerebrospinal Fluid Cytokines in Multiple System Atrophy: a Cross-Sectional Catalan MSA Registry Study
Introduction: Neuroinflammation is a potential player in neurodegenerative conditions, particularly the aggressive ones, such as multiple system atrophy (MSA). Previous reports on cytokine levels in MSA using serum or cerebrospinal fluid (CSF) have been inconsistent, including small samples and a limited number of cytokines, often without comparison to Parkinson's disease (PD), a main MSA differential diagnosis.
Methods: Cross-sectional study of CSF levels of 38 cytokines using a multiplex assay in 73 participants: 39 MSA patients (19 with parkinsonian type [MSAp], 20 with cerebellar type [MSAc]; 31 probable, 8 possible), 19 PD patients and 15 neurologically unimpaired controls. None of the participants was under non-steroidal anti-inflammatory drugs at the time of the lumbar puncture.
Results: There were not significant differences in sex and age among participants. In global non-parametric comparisons FDR-corrected for multiple comparisons, CSF levels of 5 cytokines (FGF-2, IL-10, MCP-3, IL-12p40, MDC) differed among the three groups. In pair-wise FDR-corrected non-parametric comparisons 12 cytokines (FGF-2, eotaxin, fractalkine, IFN-α2, IL-10, MCP-3, IL-12p40, MDC, IL-17, IL-7, MIP-1β, TNF-α) were significantly higher in MSA vs. non-MSA cases (PD + controls pooled together). Of these, MCP-3 and MDC were the most significant ones, also differed in MSA vs. PD, and were significant MSA-predictors in binary logistic regression models and ROC curves adjusted for age. CSF levels of fractalkine and MIP-1α showed a strong and significant positive correlation with UMSARS-2 scores.
Conclusion: Increased CSF levels of cytokines such as MCP-3, MDC, fractalkine and MIP-1α deserve consideration as potential diagnostic or severity biomarkers of MSA.info:eu-repo/semantics/publishedVersio
Statistical validation of Aeolus L2A particle backscatter coefficient retrievals over ACTRIS/EARLINET stations on the Iberian Peninsula
The Global Observing System (GOS) has encountered some limitations due to a lack of worldwide
real-time wind measurements. In this context, the European Space Agency (ESA) has developed the Aeolus satellite
mission, based on the ALADIN (Atmospheric Laser Doppler Instrument) Doppler wind lidar; this mission
aims to obtain near-real-time wind retrievals at the global scale. As spin-off products, the instrument retrieves
aerosol optical properties such as particle backscatter and extinction coefficients. In this work, a validation of Aeolus
reprocessed (baseline 10) co-polar backscatter coefficients (
part
Aeolus) is presented through an intercomparison
with analogous ground-based measurements taken at the ACTRIS (Aerosols, Clouds and Trace gases Research
InfraStructure Network)/EARLINET (European Aerosol Research Lidar Network) stations of Granada (Spain),
Évora (Portugal) and Barcelona (Spain) over the period from July 2019 until October 2020. Case studies are first
presented, followed by a statistical analysis. The stations are located in a hot spot between Africa and the rest
of Europe, which guarantees a variety of aerosol types, from mineral dust layers to continental/anthropogenic
aerosol, and allows us to test Aeolus performance under different scenarios. The so called Aeolus-like profiles
(
part
Aeolus like;355) are obtained from total particle backscatter coefficient and linear particle depolarization
ratio (
part
linear) profiles at 355 and 532 nm measured from the surface, through a thorough bibliographic review of
dual-polarization measurements for relevant aerosol types. Finally, the study proposes a relation for the spectral
conversion of
part
linear, which is implemented in the Aeolus-like profile calculation. The statistical results show
the ability of the satellite to detect and characterize significant aerosol layers under cloud-free conditions, along
with the surface effect on the lowermost measurements, which causes the satellite to largely overestimate copolar
backscatter coefficients. Finally, the Aeolus standard correct algorithm middle bin (SCAmb) shows a better
agreement with ground-based measurements than the standard correct algorithm (SCA), which tends to retrieve negative and meaningless coefficients in the clear troposphere. The implementation of Aeolus quality flags entails
a vast reduction in the number of measurements available for comparison, which affects the statistical
significance of the results
First use of a compound-specific stable isotope (CSSI) technique to trace sediment transport in upland forest catchments of Chile.
Land degradation is a problem affecting the sustainability of commercial forest plantations. The identification of critical areas prone to erosion can assist this activity to better target soil conservation efforts. Here we present the first use of the carbon-13 signatures of fatty acids (C14 to C24) in soil samples for spatial and temporal tracing of sediment transport in river bodies of upland commercial forest catchments in Chile. This compound-specific stable isotope (CSSI) technique was tested as a fingerprinting approach to determine the degree of soil erosion in pre-harvested forest catchments with surface areas ranging from 12 to 40ha. For soil apportionment a mixing model based on a Bayesian inference framework was used (CSSIAR v.2.0). Approximately four potential sediment sources were used for the calculations of all of the selected catchments. Unpaved forestry roads were shown to be the main source of sediment deposited at the outlet of the catchments (30-75%). Furthermore, sampling along the stream channel demonstrated that sediments were mainly comprised of sediment coming from the unpaved roads in the upper part of the catchments (74-98%). From this it was possible to identify the location and type of primary land use contributing to the sediment delivered at the outlet of the catchments. The derived information will allow management to focus efforts to control or mitigate soil erosion by improving the runoff features of the forest roads. The use of this CSSI technique has a high potential to help forestry managers and decision makers to evaluate and mitigate sources of soil erosion in upland forest catchments. It is important to highlight that this technique can also be a good complement to other soil erosion assessment and geological fingerprinting techniques, especially when attempting to quantify (sediment loads) and differentiate which type of land use most contributes to sediment accumulation
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