Análisis y comparación de los sistemas de interacción didáctica : Aschner-Gallagher y Claim, Claim y G. Vázquez.

Buscar la concomitancia existente entre los sistemas de interacción didáctica Aschner-Gallagher y Claim, Claim y G. Vázquez, a través del coeficiente de contingencia. Interacción didáctica en varias clases de segundo de EGB. Análisis de los distintos sistemas de interacción en el aula: Claim, Vázquez, Aschner-Gallagher, y Flanders comparación cuantitativa de los sistemas Aschner-Gallagher y Claim, Claim y G. Vázquez. En el sistema Aschner-Gallagher se estudian los siguientes factores: rutina, memoria cognitiva, pensamiento convergente, pensamiento divergente, pensamiento evaluativo, del sistema Claim se estudian los comportamientos y los niveles cognitivos. Del sistema Vázquez sus categorías. Grabaciones en cinta magnetofónica de doce horas de diferentes clases dadas por cinco profesores distintos de segundo de EGB. Frecuencias. Coeficiente de contingencia. Correlación de frecuencias por pares de categorías. El coeficiente de contingencia entre los sistemas Aschner-Gallagher y Claim no es muy elevado, tan solo un 0,696, lo que significa baja concomitancia entre ambos. Sin embargo, el coeficiente obtenido en la comparación del sistema de Claim y el de G. Vázquez, se deduce una alta concomitancia. De la correlación de frecuencias se deduce que en el aula predominan las preguntas directas y cerradas sobre las amplias y divergentes en todos los sistemas analizados. Propone un nuevo sistema de interacción didáctica basado en todos los sistemas analizados y al que se denomina BGBQ. Fecha finalización tomada del código del documento.

Sentencia de la Corte Constitucional del Ecuador sobre la constitucionalidad de la obligación del afianzamiento tributario (Jurisprudencia)

Los sujetos pasivos que impugnen ante la vía judicial un acto administrativo mediante el cual se pretenda determinar o recaudar tributos, deben rendir una caución equivalente al 10% de la cuantía de su demanda, de no presentársela en el término de quince días, el acto impugnado queda ejecutoriado y los jueces deben ordenar el archivo del proceso. Nuestra Corte Constitucional para el Período de Transición considera que no se vulnera derecho alguno en ese caso, siempre y cuando se exija rendir la caución después de calificada la demanda. Estudiaremos los fundamentos que tuvo la Corte Constitucional para llegar a esa conclusión. Pretenderemos analizarlos y cuestionarlos objetivamente, para así demostrar por qué su falta de coherencia y de sustento permite concluir que su análisis pecó por falto de imparcialidad, y por qué es razonable suponer que sus móviles no fueron jurídicos en lo absoluto, sin perjuicio de que, a la par, demos nuestro parecer al respecto. Independientemente de la trascendencia jurídica que puedan o no tener en nuestro ordenamiento, esperamos se entienda por qué creemos que estos precedentes deben ser considerados como un capítulo funesto en la historia de la jurisprudencia constitucional ecuatoriana.

Forest Policy Scenario Analysis: Sensitivity of Songbird Community to Changes in Forest Cover Amount and Configuration

Changes in mature forest cover amount, composition, and configuration can be of significant consequence to wildlife populations. The response of wildlife to forest patterns is of concern to forest managers because it lies at the heart of such competing approaches to forest planning as aggregated vs. dispersed harvest block layouts. In this study, we developed a species assessment framework to evaluate the outcomes of forest management scenarios on biodiversity conservation objectives. Scenarios were assessed in the context of a broad range of forest structures and patterns that would be expected to occur under natural disturbance and succession processes. Spatial habitat models were used to predict the effects of varying degrees of mature forest cover amount, composition, and configuration on habitat occupancy for a set of 13 focal songbird species. We used a spatially explicit harvest scheduling program to model forest management options and simulate future forest conditions resulting from alternative forest management scenarios, and used a process-based fire-simulation model to simulate future forest conditions resulting from natural wildfire disturbance. Spatial pattern signatures were derived for both habitat occupancy and forest conditions, and these were placed in the context of the simulated range of natural variation. Strategic policy analyses were set in the context of current Ontario forest management policies. This included use of sequential time-restricted harvest blocks (created for Woodland caribou (Rangifer tarandus) conservation) and delayed harvest areas (created for American marten (Martes americana atrata) conservation). This approach increased the realism of the analysis, but reduced the generality of interpretations. We found that forest management options that create linear strips of old forest deviate the most from simulated natural patterns, and had the greatest negative effects on habitat occupancy, whereas policy options that specify deferment and timing of harvest for large blocks helped ensure the stable presence of an intact mature forest matrix over time. The management scenario that focused on maintaining compositional targets best supported biodiversity objectives by providing the composition patterns required by the 13 focal species, but this scenario may be improved by adding some broad-scale spatial objectives to better maintain large blocks of interior forest habitat through time.

Amount of substance and the Mole

The International System of Units, the SI, is built upon seven base quantities and seven base units, as summarized in the table below. Although most of these are familiar to all scientists, the quantity “amount of substance” and its unit “mole” are less familiar and are mainly used by chemists.1 In the chemistry community, the unit “mole” is familiar, but the name of the corresponding quantity “amount of substance” is not so familiar, and the concept is still a source of difficulty for many students. This article reviews and clarifies these two concepts2 and discusses the definition of the unit “mole” and its possible revision.

Amount of substance and the proposed redefinition of the mole

There has been considerable discussion about the merits of redefining four of the base units of the SI, including the mole. In this paper, the options for implementing a new definition for the mole based on a fixed value for the Avogadro constant are discussed. They are placed in the context of the macroscopic nature of the quantity amount of substance and the opportunity to introduce a system for molar and atomic masses with unchanged values and consistent relative uncertainties.

Amount of substance and the mole

The unit mole is very familiar amongst both chemists and physicists, but the name of the corresponding quantity 'amount of substance' is not so familiar and the concept is still a source of difficulty for many students. This paper reviews and clarifies these concepts and also discusses the definition of the unit mole, and its possible revision.

The absorption of vitamin E is influenced by the amount of fat in a meal and the food matrix

Vitamin E absorption requires the presence of fat; however, limited information exists on the influence of fat quantity on optimal absorption. In the present study we compared the absorption of stable-isotope-labelled vitamin E following meals of varying fat content and source. In a randomised four-way cross-over study, eight healthy individuals consumed a capsule containing 150 mg H-2-labelled RRR-alpha-tocopheryl acetate with a test meal of toast with butter (17.5 g fat), cereal with full-fat milk (17.5 g fat), cereal with semi-skimmed milk (2.7 g fat) and water (0g fat). Blood was taken at 0, 0.5, 1, 1.5, 2, 3, 6 and 9 h following ingestion, chylomicrons were isolated, and H-2-labelled alpha-tocopherol was analysed in the chylomicron and plasma samples. There was a significant time (P<0.001) and treatment effect (P<0.001) in H-2-labelled alpha-tocopherol concentration in both chylomicrons and plasma between the test meals. H-2-labelled alpha-tocopherol concentration was significantly greater with the higher-fat toast and butter meal compared with the low-fat cereal meal or water (P< 0.001), and a trend towards greater concentration compared with the high-fat cereal meal (P= 0.065). There was significantly greater H-2-labelled α-tocopherol concentration with the high-fat cereal meal compared with the low-fat cereal meal (P< 0.05). The H-2-labelled alpha-tocopherol concentration following either the low-fat cereal meal or water was low. These results demonstrate that both the amount of fat and the food matrix influence vitamin E absorption. These factors should be considered by consumers and for future vitamin E intervention studies.

Effect of changing the amount and type of fat and carbohydrate on insulin sensitivity and cardiovascular risk: the RISCK (Reading, Imperial, Surrey, Cambridge, and Kings) trial

Background: Insulin sensitivity (Si) is improved by weight loss and exercise, but the effects of the replacement of saturated fatty acids (SFAs) with monounsaturated fatty acids (MUFAs) or carbohydrates of high glycemic index (HGI) or low glycemic index (LGI) are uncertain. Objective: We conducted a dietary intervention trial to study these effects in participants at risk of developing metabolic syndrome. Design: We conducted a 5-center, parallel design, randomized controlled trial [RISCK (Reading, Imperial, Surrey, Cambridge, and Kings)]. The primary and secondary outcomes were changes in Si (measured by using an intravenous glucose tolerance test) and cardiovascular risk factors. Measurements were made after 4 wk of a high-SFA and HGI (HS/HGI) diet and after a 24-wk intervention with HS/HGI (reference), high-MUFA and HGI (HM/HGI), HM and LGI (HM/LGI), low-fat and HGI (LF/HGI), and LF and LGI (LF/LGI) diets. Results: We analyzed data for 548 of 720 participants who were randomly assigned to treatment. The median Si was 2.7 × 10−4 mL · μU−1 · min−1 (interquartile range: 2.0, 4.2 × 10−4 mL · μU−1 · min−1), and unadjusted mean percentage changes (95% CIs) after 24 wk treatment (P = 0.13) were as follows: for the HS/HGI group, −4% (−12.7%, 5.3%); for the HM/HGI group, 2.1% (−5.8%, 10.7%); for the HM/LGI group, −3.5% (−10.6%, 4.3%); for the LF/HGI group, −8.6% (−15.4%, −1.1%); and for the LF/LGI group, 9.9% (2.4%, 18.0%). Total cholesterol (TC), LDL cholesterol, and apolipoprotein B concentrations decreased with SFA reduction. Decreases in TC and LDL-cholesterol concentrations were greater with LGI. Fat reduction lowered HDL cholesterol and apolipoprotein A1 and B concentrations. Conclusions: This study did not support the hypothesis that isoenergetic replacement of SFAs with MUFAs or carbohydrates has a favorable effect on Si. Lowering GI enhanced reductions in TC and LDL-cholesterol concentrations in subjects, with tentative evidence of improvements in Si in the LF-treatment group. This trial was registered at clinicaltrials.gov as ISRCTN29111298.