Transient VO2 Characteristics in Children at the Onset of Steady-Rate Exercise     

Patty S. Freedson  Thomas B. Gilliam  Stanley P. Sady  Victor L. Katch 《Research quarterly for exercise and sport》2013,84(2):167-173

Abstract

The transient oxygen uptake (VO₂) response during the initial phase of exercise was investigated in 28 children (mean age ± SD = 10.2 ± 2.28 years) during constant load submaximum bicycle ergometer exercise (mean power output ± SD = 56 ± 4.0 watts; mean VO₂ ± SD = .92 ± .141 [mdot] min^-1). The VO₂ half-time (VO₂ - t½) averaged (± SD) 34.8 (± 12.70) sec which is similar to that observed in adults. Examination of the VO₂-t ½ response as it related to age (7 to 14 years) showed that younger children attained steady-rate VO₂ more quickly than older children (r = .77 between age and VO₂-t½, P < .05). Body size, maturational level, exercise intensity, cardiorespiratory factors, and anaerobic potential are suggested as possible factors accounting for the positive age vs VO₂-t ½ relationship.  相似文献   

Some assembly required: How scientific explanations are constructed during clinical interviews     

Bruce L. Sherin  Moshe Krakowski  Victor R. Lee 《科学教学研究杂志》2012,49(2):166-198

This article is concerned with commonsense science knowledge, the informally gained knowledge of the natural world that students possess prior to formal instruction in a scientific discipline. Although commonsense science has been the focus of substantial study for more than two decades, there are still profound disagreements about its nature and origin, and its role in science learning. What is the reason that it has been so difficult to reach consensus? We believe that the problems run deep; there are difficulties both with how the field has framed questions and the way that it has gone about seeking answers. In order to make progress, we believe it will be helpful to focus on one type of research instrument—the clinical interview—that is employed in the study of commonsense science. More specifically, we argue that we should seek to understand and model, on a moment‐by‐moment basis, student reasoning as it occurs in the interviews employed to study commonsense science. To illustrate and support this claim, we draw on a corpus of interviews with middle school students in which the students were asked questions pertaining to the seasons and climate phenomena. Our analysis of this corpus is based on what we call the mode‐node framework. In this framework, student reasoning is seen as drawing on a set of knowledge elements we call nodes, and this set produces temporary explanatory structures we call dynamic mental constructs. Furthermore, the analysis of our corpus seeks to highlight certain patterns of student reasoning that occur during interviews, patterns in what we call conceptual dynamics. These include patterns in which students can be seen to search through available knowledge (nodes), in which they assemble nodes into an explanation, and in which they converge on and shift among alternative explanations. © 2011 Wiley Periodicals, Inc. J Res Sci Teach 49: 166–198, 2012  相似文献   

Cognitive Development and Comprehension of Physics Concepts     

Victor Y. Billeh  Khalil Khalili 《International Journal of Science Education》2013,35(1):95-104

Summaries

English

The purpose of this study was twofold: (1) to investigate the cognitive development of llth‐grade science students in Jordan; and (2) to investigate the relationship between cognitive development of science students and their comprehension of concrete and formal physics concepts.

The sample of this study consisted of 389 secondary science students (209 males and 180 females) of the school year 1979‐1980. Cognitive development of the students was measured by an Arabic version of the Longeot Test. Comprehension of physics concepts was assessed by an achievement test constructed by the researchers and validated by teachers of physics and the science supervisor in the Irbid district of Jordan.

The study did not reveal any significant difference between males and females in cognitive development. Moreover, it revealed that only 17% of the students were formal thinkers, whereas 52% were concrete thinkers.

The 2×3 ANOVA revealed that cognitive level was a highly significant factor in the comprehension of both concrete and formal concepts. It also revealed that while sex was not a significant factor in the comprehension of concrete concepts, it was a significant factor in the comprehension of formal concepts. The interaction between sex and cognitive level was not significant in the comprehension of both types of concepts.  相似文献   

Argument-Driven Inquiry as a Way to Help Undergraduate Students Write to Learn by Learning to Write in Chemistry     

Victor Sampson  Joi Phelps Walker 《International Journal of Science Education》2013,35(10):1443-1485

This exploratory study examined how undergraduate students’ ability to write in science changed over time as they completed a series of laboratory activities designed using a new instructional model called argument-driven inquiry. The study was conducted in a single section of an undergraduate general chemistry lab course offered at a large two-year community college located in the southeast USA. The intervention took place over a 15-week semester and consisted of six laboratory activities. During each laboratory activity, the undergraduates wrote investigation reports, participated in a double-blind group peer review of the reports, and revised their reports based on the reviews. The reports written during each laboratory activity were used to examine changes in the students’ writing skills over time and to identify aspects of scientific writing that were the most difficult for the undergraduates in this context. The reviews produced by the students during each report were used to evaluate how well undergraduates engage in the peer-review process. The results of a quantitative and qualitative analysis of the reports and reviews indicate that the participants made significant improvements in their ability to write in science and were able to evaluate the quality of their peers’ writing with a relatively high degree of accuracy, but they also struggled with several aspects of scientific writing. The conclusions and implications of the study include recommendations for helping undergraduate students learn to write by writing to learn in science and new directions for future research.  相似文献   

Peer Judgments of Teaching Competence as a Function of Field Independence and Dogmatism,     

James B. Victor 《Journal of Experimental Education》2013,81(3):10-13

The theoretical relationships among field independence, dogmatism, and a peer judgment criterion of professional competence were examined. The subjects were master’s level interns in a training program. The data illustrate the reliability of the criterion and indicate that these interns differentiate between professional competence judgments and more interpersonal judgments when making peer choices. Neither dogmatism nor field independence alone predicts the criterion, but the interaction term for the two variables significantly predicts the criterion. It is the field dependent/highly dogmatic person who is chosen less often by his peers, while the field dependent/low dogmatic person is chosen more often.  相似文献   

Non-abandonment as a foundation for inclusive school practice     

Michal Razer  Victor J. Friedman 《Prospects》2013,43(3):361-375

The authors of this article describe an essential feature of inclusive educational practice: non-abandonment. When students’ needs and difficult behavior are overwhelming, teachers may abandon them emotionally as a defensive reaction to their own experience of emotional distress and helplessness. Non-abandonment represents a constructive strategy for dealing with these students based on the psychodynamic concepts of containing and holding. The authors provide a theoretical grounding for the processes of abandonment and non-abandonment, and then illustrate how these two processes play themselves out in school practice, drawing on action research conducted with educators in Israeli schools. They then describe eight elements in an active strategy of non-abandonment. These are: (1) make a conscious choice to assume professional responsibility for these students; (2) “stand by” students whose behaviour leads others to abandon them; (3) reframe self-defeating ways of thinking to open new avenues for action; (4) attempt to understand students’ real needs, including emotional ones; (5) adapt teaching practice to meet these needs, even going beyond traditional pedagogy; (6) create school frameworks in which teachers can systematically reflect on and improve practice; (7) address teachers’ emotional needs by making their own negative feelings openly discussable; and (8) promote teamwork and supportive relations among school faculty based on honest feedback and mutual non-abandonment.  相似文献   

El lugar de los procedimientos de aprendizaje «espontáneo» en la formación científica     

Victor Host 《Infancia y Aprendizaje》2013,36(19-20):3-19

RESUMEN

Un modelo pedagógico informal, basado únicamente en los aprendizajes espontáneos, no es suficiente para alcanzar los objetivos que caracterizan al pensamiento científico. Hay que encontrar una forma de articular los aprendizajes espontáneos y los aprendizajes sistemáticos, en el marco de la pedagogía activa. Se propone un modelo pedagógico basado en favorecer una serie de actividades funcionales de investigación en una situación de autonomía que responda a las necesidades de aprendizaje del alumno y sobre las cuales se construyan las redes conceptuales. Los aprendizajes sistemáticos (para la adquisición de conocimientos o de habilidades) intervienen en diferentes momentos de este proceso. Realizando la investigación didáctica adecuada, este modelo de aprendizaje puede llegar a ser operativo.  相似文献   

The Mother's Magazine: moral media for an emergent domestic pedagogy, 1833–1848     

Matthew Victor Schertz 《Gender and education》2009,21(3):309-320

This paper presents a theoretical analysis of selected passages from The Mother's Magazine, one of the first periodicals for women published in the USA. Of particular interest are selections that highlight desirable maternal characteristics and those that described the intended pedagogical experiences within the domestic sphere. The layout, overarching themes and content of specific articles provide a gateway to discern contributors' attempts at moral regulation. The authors facilitated a character education initiative to ensure that both mother and child would be dutiful and thoughtful Christian citizens. There is also a focus to secure the proliferation of industrious, gendered subjects. It could be argued that the periodical marks the transition from a Calvinist to a Lockean conception of childhood. More accurately, the magazine utilises modern methods of childrearing while still adhering to an evangelical ideology that both reinforces traditional power structures and redefines the role of mother for the emerging nuclear family.  相似文献   

Effects of different percentages of body weight support on spatiotemporal step characteristics during running     

Luis E. Roche-Seruendo  Isabel Auria-Martin  Ana V. Bataller-Cervero  Pedro A. Latorre Román  Victor M. Soto -Hermoso 《Journal of sports sciences》2018,36(13):1441-1446

This study aimed to determine the effect of different percentages of body weight support (BWS) on spatiotemporal step characteristics during running. 26 endurance runners (age: 37 ± 9 years) completed a running treadmill protocol consisting of 6 different conditions (BWS combinations: 0–50%), with velocity maintained at 12 km/h. Each condition lasted 1 minute. Step angle, ground contact time (CT), flight time (FT), step length (SL) and frequency (SF), and duration of phases during stance time (phase1: initial contact; phase2: midstance; phase3: propulsion) were measured for every step during the test using a photoelectric cell system. Compared with the baseline condition (100% BW), FT was longer, CT was shorter, SL was longer, SF was lower, and the step angle was higher with each increase in BWS (p < 0.05). Also, some changes were observed in the duration of phases during stance time: phase1 did not experience changes across experimental conditions (p = 0.096), phase2 decreased and phase3 increased as BW was supported (p < 0.05). These results indicate that as BW was supported, runners showed longer FT and SL, shorter CT, lower SF, and greater step angle as well as some changes in the phases during the ground contact. Therefore, this study highlights the effect of different percentages of BWS on spatiotemporal parameters.  相似文献   

Achieving Learning Goals with Student-Created Podcasts     

Gary R. Armstrong  Joanne M. Tucker  Victor J. Massad 《Decision Sciences Journal of Innovative Education》2009,7(1):149-154

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