Intermittent hypoxia exposure in a hypobaric chamber and erythropoietin abuse interpretation

Abstract

The aim of this study was to assess the effect of intermittent hypoxia exposure on direct and indirect methods used to evaluate recombinant human erythropoietin (rhEPO) misuse. Sixteen male triathletes were randomly assigned to either the intermittent hypoxia exposure group (experimental group) or the control normoxic group (control group). The members of the experimental group were exposed to simulated altitude (from 4000 to 5500 m) in a hypobaric chamber for 3 h per day, 5 days a week, for 4 weeks. Blood and urine samples were collected before and after the first and the final exposures, and again 2 weeks after the final exposure. While serum EPO significantly increased after the first [from a mean 8.3 IU · l^?1 (s = 3.2) to 16.6 IU · l^?1 (s = 4.7)] and final exposures [from 4.6 IU · l^?1 (s = 1.4) to 24.8 IU · l^?1 (s = 9.3)], haemoglobin, percentage of reticulocytes, and soluble transferrin receptor were not elevated. Second-generation ON/OFF models (indirect rhEPO misuse detection) were insensitive to intermittent hypoxia exposure. The distribution of the urinary EPO isoelectric profiles (direct rhEPO misuse detection) was altered after intermittent hypoxia exposure with a slight shift towards more basic isoforms. However, those shifts never resulted in misinterpretation of results. The intermittent hypoxia exposure protocol studied did not produce any false-positive result for indirect or direct detection of rhEPO misuse in spite of the changes in EPO serum concentrations and urinary EPO isoelectric profiles, respectively.     

In and of the City: Theory of Action and the NYU Partnership School Program

This article explores the theory of action underlying New York University's (NYU's) Partnership Schools Program—explaining in the process what a theory of action is, and how it can be constructed for other innovations in other contexts. NYU's Partnership Program involves 23 schools, K-12, spanning several of New York City's most economically disadvantaged neighborhoods. It operates on the basis of what the authors call “mutual self-interest” and exploits what they call “complementarity.” The authors illuminate the program's original as well as its evolving intentions, and the environmental conditions necessary to enact them and to sustain the program over a decade. They also describe the program's core design elements, with a view to how these may be replicated elsewhere. Finally, they look closely at the Partnership's theory of action in action, employing action research data to portray a meeting where professors and teachers discuss the teacher education residency experiment they have collaboratively launched.     

La construcción individual del sistema de numeración convencional

Resumen

El sistema de numeración posicional de base 10 constituye un objeto cultural, resultado de un largo y dificultoso desarrollo histórico, que se convierte en un objeto de conocimiento a asimilar por el niño. En este artículo se estudia el proceso de reconstrucción individual de este instrumento intelectual, a través de las producciones gráficas espontáneas de 100 niños de edades comprendidas entre los 6 y 10 años, obtenidas en situación de invención de sistemas de notación de cantidades. Las producciones de los niños, cuyas estrategias recuerdan en muchos casos a las empleadas en los sistemas de numeración históricos, describen una génesis. Esta se extiende desde producciones que no contemplan la estabilidad de los grafismos ni la posibilidad de combinarlos, hasta las que recurren al principio del valor posicional, pasando por producciones de tipo aditivo y producciones que intentan, sin conseguirlo, la transposición del sistema de numeración convencional.     

Computadores,comunicación y educación: una colaboración internacional en la intervención e investigación educativa

Resumen

El presente articulo describe y justifica teóricamente una actividad educativa que induye el uso de microcomputadores a través de una comunicación telemática. Esta actividad consiste en la redacción de una revista bilingüe (inglés-español) en la que colaboran niños de diversas culturas. A través de esta actividad se trabajan temas como la «alfabetización informàtica», la composición de textos y los idiomas. Esta intervención educativa viene acompañada de un intercambio de información científica a través de una red académica de comunicaciones telemáticas para el intercambio de información científica. El marco teórico en el que se desarrolla este trabajo se deriva del de la psicología vygotskiana y de alguno de sus desarrollos posteriores.     

Empatía,Role-taking y concepto de ser humano,como factores asociados a la conducta prosocial/altruista

Resumen

Se trata de un estudio realizado con 224 sujetos, de ambos sexos, entre 10 y 12 años, de tres ciudades distintas (Salamanca, Málaga y Donostia). En él se estudia el poder predictor de la empatía, la capacidad de ponerse en el punto de vista de los demás y el concepto de hombre sobre la conducta prosocial altruista. Los resultados demuestran un alto poder predictor de estos factores.     

Voluntary Interdistrict Choice Program: Examining Black Girls’ Experiences at a Predominately White School

The Urban Review - A plethora of research on voluntary school choice programs and the impact on student’s outcomes have been documented. However, lacking are the experiences of students of...     

Primary and secondary teachers’ conceptions about heritage and heritage education: A comparative analysis

This study describes and analyses the conceptions of primary teachers and secondary teachers of Physics–Chemistry, Biology–Geology and Geography–History with respect to the concept of heritage and its teaching and learning, taking the model of teacher-researcher as the theoretical referent. The data collection instrument used was a questionnaire, designed on the basis of categories that in turn were used for the analysis of the resulting data. The results show a high degree of homogeneity in pedagogic content knowledge, in contrast to the heterogeneity of the conceptions with respect to purely content knowledge.     

Actitudes,valores y normas: aprendizaje y desarrollo moral

En este artículo se constata el creciente reconocimiento del campo del desarrollo moral en el marco de la investigación cognitiva, tanto desde la perspectiva psicológica como social. Se relacionan competencias psicosociales, procesos de maduración y procesos de aprendizaje, sugiriéndose pautas para la actuación del profesorado en torno a las actitudes, valores y normas.     

The Conceptions of In-service and Prospective Primary School Teachers About the Teaching and Learning of Science

A study was performed to describe and analyze the conceptions about teaching and learning science held by different samples of teachers in Spain. The responses of 265 teachers (107 prospective teachers and 158 active teachers) to items from the Inventory of Scientific and Pedagogical Beliefs (Porlán, 1989) were subjected to multifactorial analysis. The results showed various tendencies in how the teaching/learning process is viewed, ranging from a predominant view based on the transmission-reception of knowledge to a minority constructivist view. There was a greater diversity of viewpoints among the in-service teachers than among the prospective teachers. In both samples, the most representative tendency was learning as appropriation of meanings, followed by a technical view of teaching among the prospective teachers and a more traditional view among the in-service teachers. Finally, some implications for teacher education are discussed.