Effects of active, passive or no warm-up on metabolism and performance during high-intensity exercise

The aim of this study was to determine the influence of type of warm-up on metabolism and performance during high-intensity exercise. Eight males performed 30 s of intense exercise at 120% of their maximal power output followed, 1 min later, by a performance cycle to exhaustion, again at 120% of maximal power output. Exercise was preceded by active, passive or no warm-up (control). Muscle temperature, immediately before exercise, was significantly elevated after active and passive warm-ups compared to the control condition (36.9 +/- 0.18 degrees C, 36.8 +/- 0.18 degrees C and 33.6 +/- 0.25 degrees C respectively; mean +/- sx) (P< 0.05). Total oxygen consumption during the 30 s exercise bout was significantly greater in the active and passive warm-up trials than in the control trial (1017 +/- 22, 943 +/- 53 and 838 +/- 45 ml O2 respectively). Active warm-up resulted in a blunted blood lactate response during high-intensity exercise compared to the passive and control trials (change = 5.53 +/- 0.52, 8.09 +/- 0.57 and 7.90 +/- 0.38 mmol x l(-1) respectively) (P < 0.05). There was no difference in exercise time to exhaustion between the active, passive and control trials (43.9 +/- 4.1, 48.3 +/- 2.7 and 46.9 +/- 6.2 s respectively) (P= 0.69). These results indicate that, although the mechanism by which muscle temperature is elevated influences certain metabolic responses during subsequent high-intensity exercise, cycling performance is not significantly affected.     

The Early Childhood Teacher's Voice in the Research Community La Voix de l'Educateur des Jeunes Enfants dans le Monde de la Recherche La Voz del Profesor de la Primera Infancia en la Comuniad Investigadora

This paper focuses attention on the early childhood teacher's place in the research community. It provides a look at the teachers' perspectives of research and then points out ways and reasons for early childhood teachers to become more active as classroom researchers, research partners and consumers of research through pre-service and in-service opportunities. After providing a definition of teacher research as systematic inquiry into one's own classroom, it discusses the value of such research and identifies historical support for it. The paper presents examples of partnership research using a video camera as a tool for data collection and teachers' reactions to it. It also provides quotes of individual teacher's introduction to teacher research and some points to consider in embarking on classroom research. Cette conference traite de la place de l'enseignant de la petite enfance dans le monde de la recherche. Nous allons examiner les perspectives des enseignants en matiere de recherche, puis indiquer comment et pourquoi rendre les enseignants de la petite enfance plus actifs en tant que chercheurs dans le cadre de la classe, partenaires de recherche et consommateurs de recherche grace a des opportunites offertes avant et pendant leur enseignement. Apres avoir fourni une definition de la recherche des enseignants en tant qu'examen systematique de leur propre classe, nous examinerons la valeur de cette recherche a l'aide d'une camera video comme outil de collecte de donnees et les reactions des enseignants. Nous citerons egalement l'opinion d'enseignants formes a cette recherche et nous signalerons quelques aspects a considerer avant de lancer une recherche en classe. Esta charla centra su atencion en la posicion del profesor de pequenos en la comunidad investigadora. Ofrece un idea de las perspectivas de investigacion de los profesores y luego senala maneras y razones para que los profesores de ninos pequenos sean mas activos como investigadoes de clase, socios de investigacion y consumidoes de investigacion a traves de oporunidades de preservicio y en servicio. Despues de facilitar una definicion de la investigacion de profesores como encuesta sistematica del aula propia, se habla del valor de dicha investigacion y se identifica un apoyo historico para la misma. Esta charla presenta ejemplos de investigacion conjunta usando videocamara como herramienta para la recopilacion de datos y reacciones de los profesores. Tambien ofrece citas de introducciones individuales de profesores a la investigacion de profesores y algunos puntos a considerar al emprender la investigacion de una clase.     

Path analysis: A model for the development of scientific reasoning abilities in adolescents

A model was formulated and tested for the development of scientific reasoning abilities in adolescents. Piagetian theory provided the framework for choosing potential determinants of the dependent variable, scientific reasoning abilities. A model reflecting hypothesized causal relationships among determinants and with the dependent variable was developed a priori on the basis of theoretical and substantive reasoning. The hypothesized model was tested and revised using path analysis. Data from intact classes of middle-school (n = 101) and high-school (n = 89) students from an upper-middle-class suburb of a midwestern city revealed significant (p < 0.05) path coefficients for these variables and scientific reasoning abilities: age, I.Q., field dependence–independence, and experience. A path from locus of control to scientific reasoning abilities through field dependence-independence was also statistically significant. The revised model explained 61 percent of the variance in scientific reasoning abilities.