Autorregulación del aprendizaje: una revisión sistemática en revistas de la base SciELO / Self'Regulated Learning: A Systematic Review Based in Scielo Journals

El concepto de autorregulación del aprendizaje ha asumido una importancia creciente en la literatura, ya que la investigación ha sugerido que los alumnos participan activamente en su proceso de aprendizaje, monitorizando y regulando su proceso de estudio con el fin de alcanzar determinados objetivos. La información recogida en revistas indexadas en la base Scielo, en cuanto a la autorregulación, todavía no ha sido sistematizada convenientemente. Por ello, se ha realizado una revisión sistemática de la literatura, con base en datos SciELO.org, en el período comprendido entre el año 2001 y el año 2011, para analizar las evidencias recogidas en diferentes investigaciones sobre: a) la naturaleza del aprendizaje autorregulado, b) su evaluación, c) la promoción de habilidades para la autorregulación y su utilidad en el contexto educativo y d) la posibilidad de implicación de los profesores en la promoción de dicho aprendizaje.

The concept of self-regulation in learning has been assuming a rising importance in the literature once the research has suggested that students participate actively in their learning process, monitoring and regulating their study process to achieve self-set goals. Nevertheless, the information about self-regulation has not been yet systematized on the journals indexed in Scielo. Therefore, the current study performed a systematic review of the literature on Scielo.org, between the period 2001 and 2011 to analyze the existence evidence regarding: a) the nature of self-regulated learning, b) it's assessment, c) the promotion of self-regulated skills and their usefulness in the context of education, and d) the potential implication of teachers on the promotion of lifelong learning.

Caveolin-1 associates with TRAF2 to form a complex that is recruited to tumor necrosis factor receptors.

Tumor necrosis factor (TNF) receptor-associated factor (TRAF) 2 is an intracellular adapter protein, which, upon TNF stimulation, is directly recruited to the intracellular region of TNF receptor 2 (TNFR2) or indirectly, via TRADD, to the intracellular region of TNF receptor 1 (TNFR1). In cultured human umbilical vein endothelial cells, endogenous TRAF2 colocalizes with the membrane-organizing protein caveolin-1 at regions of enrichment subjacent to the plasma membrane as detected by confocal fluorescence microscopy. Both endogenous and transfected TRAF2 protein coimmunoprecipitate with caveolin-1 in the absence of ligand. Upon TNF treatment, the TRAF2-caveolin-1 complex transiently associates with TRADD, and upon overexpression of TNFR2, the TRAF2-caveolin-1 complex stably associates with and causes redistribution of this receptor as detected by confocal fluorescence microscopy. In human embryonic kidney 293 cells, which have minimal endogenous expression of caveolin-1, cotransfection of TRAF2 and caveolin-1 results in spontaneous association of these proteins which can further associate with and redistribute transfected TNFR2 molecules. The association of caveolin-1 with TNFR2 depends upon TRAF2. Cotransfection of caveolin-1 protein increases TRAF2 protein expression levels in HEK 293 cells, which correlates with enhancement of TNF and TRAF2 signaling, measured as transcription of a NF-kappaB promoter-reporter gene, although the caveolin-enhanced response to TNF is attenuated at higher caveolin levels. These findings suggest that intracellular distribution of activated TNF receptors may be regulated by caveolin-1 via its interaction with TRAF2.

The death domain of tumor necrosis factor receptor 1 is necessary but not sufficient for Golgi retention of the receptor and mediates receptor desensitization.

TNF signals are mediated through two different receptors, TNFR1 and TNFR2. In endothelial cells, TNFR1 is predominantly localized in the Golgi apparatus and TNFR2 on the plasma membrane. To investigate structural features responsible for the disparate localization, endothelial cells were transfected with epitope-tagged or green fluorescent protein-fused wild type and mutant receptor molecules. Wild type receptors recapitulated the distribution of endogenous receptors. Deletions of the entire TNFR1 intracellular domain or of the C-terminal death domain (TNFR1(-DD)) allowed expression of the receptor on the plasma membrane. However, addition of the death domain to the C-terminus of TNFR2 (TNFR2(+DD)) did not lead to Golgi-retention of this chimeric receptor. Overexpressed TNFR1, TNFR2, and TNFR2(+DD) increased basal expression of a cotransfected NF-kappaB-dependent promotor-reporter gene. Overexpressed TNFR1(-DD) did not activate NF-kappaB but acted as a ligand-specific dominant negative inhibitor of TNF actions. Unexpectedly, TNF responses were also inhibited by overexpressed TNFR1 and TNFR2(+DD), but not TNFR2. We conclude that the death domain of TNFR1 is required for retention of TNFR1 in the Golgi apparatus but is not sufficient to direct Golgi retention of a TNFR2(+DD) chimera, and that overexpressed receptors that contain the death domain (TNFR1 and TNFR2(+DD)) spontaneously activate NF-kappaB while inhibiting TNF responses.

Treatment of traumatic brain injury with hypothermia.

Despite increasing understanding of the cellular and molecular mechanisms that cause pathology in children who suffer traumatic brain injury, few advances have been made in developing new effective therapies for such injury. In the past, clinicians treated some neurologically injured patients with the sustained application of systemic hypothermia. This practice was largely abandoned when patients experienced complications; however, interest has been renewed in treatment with milder forms of hypothermia. This review focuses on the clinical and laboratory evidence concerning this therapy. Promising results from two clinical trials are presented. Moreover, evidence is discussed in support of the notion that some children with traumatic brain injury, more so than adults, may benefit from hypothermic therapy. Lastly, putative mechanisms for the effects of hypothermia, including attenuation of injury caused by inflammation, excitotoxic amino acids, nitric oxide, and free radicals, are discussed.

Cloning of cDNA for a novel mouse membrane glycoprotein (gp42): shared identity to histocompatibility antigens, immunoglobulins and neural-cell adhesion molecules.

A full-length clone encoding a murine membrane glycoprotein, gp42, was selected from a mouse fibroblast cDNA expression library by screening with a polyclonal antiserum. The deduced amino acid (aa) sequence indicates that gp42 is a transmembrane protein of 273 aa with a large N-terminal portion exposed outside the cell and a short cytoplasmic domain. Computer assisted analysis shows that gp42 is distinct from previously characterized proteins, but shares a number of structural features with the class II histocompatibility antigens. The sizes of the extracellular domains of gp42 and of class II histocompatibility antigens are similar, the position of four cysteines and the location of several aa residues are conserved. Some of these conserved residues are also present in immunoglobulins (Ig) and in the neural-cell adhesion molecule, thus indicating that gp42 is a new member of the Ig superfamily.