The Impact of Social Constructivist Mathematics Learning Experiences on Latino, Middle School Students’ Proportional Reasoning

Due to its centrality in the curriculum, research on proportional reasoning (PR) has seen a resurgence of interest. Recent research examined students’ patterns, strategies, and achievement when solving PR problems. Other studies explored PR learning trajectories. Additional studies focused on instructional interventions such as the effect of number structure, continuous, discrete, and intensive quantities to promote the development of proportional reasoning skills (PRS). The subjects of these studies have been United States white middle school students, Icelandic grade 5 girls, Spanish secondary school students, Turkish middle school students, as well as Scottish and Korean upper primary grades’ students. Few studies examined the factors that explain how instructional experiences influence Latino, middle school students’ PRS proficiency. This study aims to contribute to the literature by examining the impact of instruction that involves manipulatives, representations, and discourse to foster the strategic competence of Latino middle school students on proportional reasoning tasks (PRT). Subjects were 80 sixth-grade Latino students with low socioeconomic background. A quasi-experimental, comparison group design was used involving two mathematics classrooms as the treatment and two classrooms as the comparison group. Each group was administered a pretest of mathematics ability and PR posttest. The teacher was a Mexican-heritage public school educator. Students varied in their mathematics ability and engaged in distinct curricula and pedagogical approaches to promote their PR development. Two treatment classrooms experienced tasks involving concrete manipulatives, multiple representations, and negotiation of meaning and two comparison classrooms received teacher-centered textbook instruction that consisted on a teacher explaining definitions and examples from the notes from the textbook, followed by individual problem-solving of worksheets from the textbook. Analysis of Covariance and Pearson Chi-Square tests reported statistically significant differences in performance and use of representational reasoning when solving proportional reasoning tasks. A significant impact was also observed on the performance in PR tasks involving one-step partitioning and non-integer relationships. Social constructivist experiences resulted in a meaningful understanding of PRS empowering Latino middle school students with stronger connections between the central ideas of PR. Participants receiving social constructivist instruction used significantly greater representational reasoning that resulted in statistically significantly higher PR strategic competence

Effect of ice sheet interactions in anthropogenic climate change simulations

We investigate the effect of ice sheets on climate change under elevated atmospheric CO2 concentrations with an atmosphere ocean general circulation model ( AOGCM) coupled to a thermomechanical ice sheet model and a vegetation model. The effect of increased meltwater fluxes from ice sheets turned out to be negligible in the phase of initial weakening of the North Atlantic meridional overturning circulation ( AMOC), and more important during the recovery in subsequent centuries. Lower surface height of the Greenland ice sheet ( GRIS) leads locally to a warming, especially in winter, and remotely to a cooling over northern Eurasia due to modified atmospheric circulation. With quadrupling of the atmospheric CO2 concentration the entire GRIS is exposed to surface melt in summer. On formerly ice-covered grid points climate locally warms strongly via increased albedos, with positive feedbacks due to boreal forest expansion

Cine-esquina: Un híbrido programático en la memoria de la ciudad chilena

Indexación: Scopus.The emblematic palace-cinemas which accompanied the rise of cinematographic exhibition in Chile during the 20th century, reflect a widespread practice codified by a series of exhibition halls that inherit the tradition of a theatrical stylistic architecture. However, this account does not take notice of another kind of halls built during the same period that entails the development of an unprecedented typology: the corner-cinema. Identified as a programmatically hybrid building, the latter incorporated specific spaces for commerce and housing in addition to the projection space, resulting in an architectural strategy that would anticipate a response to urban density. Recognizing that distinctive feature, this article exposes and classifies a set of cinemas built in Santiago and other Chilean cities that share similar characteristics in terms of their programmatic mixture and formal structures, composing a catalogue of singular works that reveals their distinctive aspects as an experience of disciplinary innovation. Located at the corner of a block, these projects not only fulfilled the requirement of modernizing the places for films as the 1920's cinematographic industry demanded, but also constituted a timely response whose logic promoted a new way to build the city. Based on this evidence, the historical perspective implied by the typological approach of this analysis provides a more general insight about the role of architecture and its ability to perform as an active component in the configuration of urban and social environment.http://www.revista180.udp.cl/index.php/revista180/article/view/74

Validity of a four-factor modelunderlying the physical fitness in adults with intellectual disabilities a confirmatory factor analysis

Purpose: To use confirmatory factor analysis to test whether a four factor might explain the clustering of the components of the physical fitness in adults with intellectual disabilities (FID). Relevance: Individuals with intellectual disabilities (ID) are significantly weaker than individuals without ID at all stages of life. These subjects might be particularly susceptible to loss of basic function because of poor physical fitness. Participants: We studied 267 adults with intellectual disability of the Spanish Special Olympics Games. Methods: The four-factor model included: the flexibility, the strength, the balance and the cardiorespiratory endurance with 9 variables of the fitness assessment. Analysis: The construct validity of the model was assessed through the factor loadings, interpreted as the correlation between the variables in the model and their underlying factor, which is the FID construct. Results: Factor loading were 0,55 for the passive knee extension, o,52 for Functional shoulder rotation, −0.71 for the timed-stand test, 0.58 for the grip test, 0.75 the single leg stance with eyes open, 0.69 single leg stance with eyes closed, 0.72 for the resting heart rate, 0.56 for the two-minute step test (2MST) 0,97 for 2 minutes after finish 2MST. The four-factor model also showed a good fit to the data, as indicated by a high comparative fit index (CFI=0,93) and a low standardized root mean square residual (SRMR=0,072) Conclusions: A four underlying factor has shown acceptable validity to represent FID Implications: The new model of FID can offer understanding better these construct in this special populationUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Effects of peroxisome proliferator-activated receptor- activation in endothelin-dependent hypertension

Aims We analysed the chronic effects of the peroxisome proliferator-activated receptor β/δ (PPAR-β) agonist GW0742 on the renin-independent hypertension induced by deoxycorticosterone acetate (DOCA)-salt. Methods and results Rats were treated for 5 weeks with: control-vehicle, control-GW0742 (5 or 20 mg kg−1 day−1), DOCA-vehicle, DOCA-GW0742 (5 or 20 mg kg−1 day−1), DOCA-GSK0660 (1 mg kg−1 day−1), and DOCA-GSK0660-GW0742. Rats receiving DOCA-vehicle showed increased systolic blood pressure, left ventricular and kidney weight indices, endothelin-1 (ET-1), and malondialdehyde plasma levels, urinary iso-PGF2α excretion, impaired endothelium-dependent relaxation to acetylcholine, and contraction to ET-1 when compared with controls. Aortic reactive oxygen species content, NADPH oxidase activity, and p47phox, p22phox, NOX-4, glutathione peroxidase 1, hemeoxygenase-1, and preproET-1 expression were increased, whereas catalase and regulators of G protein-coupled signalling proteins (RGS)5 expression were decreased in the DOCA-vehicle group. GW0742 prevented the development of hypertension in a dose-dependent manner but the reduction of renal and cardiac hypertrophy, systemic and vascular oxidative stress markers, and improvement of endothelial dysfunction were only observed after the higher dose. GW0742, at 20 mg kg−1 day−1, attenuated ET-1 contraction by increasing RGS5 expression and restored the intracellular redox balance by reducing NADPH-oxidase activity, and by increasing the antioxidant genes expression. The PPAR-β antagonist GSK0660 prevented all vascular changes induced by GW0742 but not its antihypertensive effects. Conclusion Vascular protective effects of GW0742 operate via PPAR-β by interference with the ET-1 signalling as a result of increased expression of RGS5 and up-regulation of antioxidant genes and via PPAR-β-independent mechanisms to decrease blood pressure