Cardiopulmonary loading in motocross riding

Abstract

The present study was designed to examine physiological responses during motocross riding. Nine Finnish A-level motocross riders performed a 15-min ride at a motocross track and a test of maximal oxygen uptake ([Vdot]O_2max) in the laboratory. Cardiopulmonary strain was measured continuously during the ride as well as in the [Vdot]O_2max test. During the ride, mean [Vdot]O₂ was 32 ml · kg^?1 · min^?1 (s = 4), which was 71% (s = 12) of maximum, while ventilation (V _E) was 73% (s = 15) of its maximum. The relative [Vdot]O₂ and V _E values during the riding correlated with successful riding performance (r = 0.80, P < 0.01 and r = 0.79, P < 0.01, respectively). Mean heart rate was maintained at 95% (s = 7) of its maximum. Mean blood lactate concentration was 5.0 mmol · l^?1 (s = 2.0) after the ride. A reduction of 16% (P < 0.001) in maximal isometric handgrip force was observed. In conclusion, motocross causes riders great physical stress. Both aerobic and anaerobic metabolism is required for the isometric and dynamic muscle actions experienced during a ride.     

The deterioration and mobilization effects of trauma on social support: childhood maltreatment and adulthood military violence in a Palestinian community sample

OBJECTIVES: To show that exposure to childhood maltreatment deteriorates, whereas exposure to adulthood military violence mobilizes social support; second, to show that associations between traumatic events and mental health problems are mediated through social support and, subsequently, adulthood military violence is associated with low level and childhood maltreatment with high level of mental health symptoms; third, to explore whether the moderating (protecting) effect of sufficient and satisfactory social support would differ among victims of childhood maltreatment and adulthood military violence. METHOD: The participants were a random-sample of Palestinian men and women (n=585) of 16-60 years of age. Exposure to military violence in adulthood was assessed by the Harvard Trauma Questionnaire (HTQ_I), and to childhood maltreatment by a 13-item questionnaire developed for the study. A Social Network Schedule was applied to assess the function, source, and satisfaction with social support, and the Revised SCL90-R Symptoms Checklist to assess mental health symptoms. RESULTS: Findings supported our hypothesis that exposure to childhood maltreatment was associated with low levels of social support, whereas exposure to adulthood military violence was associated with high levels of social support. Contrary to our second hypothesis, both childhood maltreatment and adulthood military violence were associated with high levels of mental health symptoms. Finally, high level and satisfactory social support moderated the association between exposure to military violence in adulthood and mental health symptoms, but not between childhood maltreatment and mental health symptoms. CONCLUSION: The findings emphasize that the nature of trauma, that is, whether familial or political, determines the availability of protective resources versus vulnerability, which should be considered when tailoring interventions to trauma victims.     

Global Self-Worth among Adolescents: The Role of Basic Psychological Need Satisfaction in Physical Education

ABSTRACT

Global self-worth is important for healthy development and learning, and is therefore highlighted as a major aim in the Norwegian physical education (PE) curriculum. Based on prior research this study aimed to assess potential differences in global self-worth and contextual basic need satisfaction among 2854 adolescents (47.5% boys, 52.5% girls, ages 13 and 16) participating in different movement contexts, and to determine whether basic need satisfaction in PE relates to global self-worth. Structural equation modeling analyses indicate that basic need satisfaction in PE relates significantly to global self-worth. However, adolescents who do not participate in movement contexts outside school report significantly lower basic need satisfaction in PE compared to their sports-active peers, and could possibly therefore experience reduced global self-worth development through PE. Findings support research showing that sports active youth reap most of the bene?ts of PE, and thus, that PE violates the principles of equal education.     

School Principal as Pedagogical Leader

The position and duties of a school principal should be rapidly changing along with the changes in the policy of school development. School‐based curriculum and staff development are the main components of the present policy. If an individual school is the basic unit of development then the role of the principal is crucial in leading pedagogical activities within the unit. This study, carried out in Finland, attempts to consider how principals see their work now. The results show that the principals’ still see their most important tasks in organisation (resource provider) and in maintaining a good climate in school.     

Talk as Data and Practice — a critical look at phenomenographic inquiry and the appeal to experience

The article continues a critical discussion of phenomenography by raising some issues on the status of interview data in such research. It is argued that it is doubtful if and in what sense the interview data generated in much of the empirical work within this tradition can be assumed to refer to “ways of experiencing”, the core object of research in phenomenography. In general, it would seem that the data must be understood as indicative of accounting practices — ways of talking and reasoning — that interviewees, for one reason or another, find appropriate when being asked questions. Very little, if anything, is gained in analytical terms by an initial commitment to a position in which the researcher connects utterances to experiences rather than to discourse, since the latter is what is in fact analyzed. It is also argued that in some important respects discursive practices must be seen as preceding experience, and that experiential accounts given by individuals are grounded in discursive patterns.     

Artifacts as authoritative actors in educational reform

Educational reforms are often translated in and implemented through artifacts. Although research has frequently treated artifacts as merely functional, more recent work acknowledges the complex relationship between material artifacts and human/organizational behavior. This article aims at disentangling this relationship in order to deepen our understanding of the role of artifacts within processes of educational change. In particular, we study the implementation of a data-transfer instrument developed to stimulate care continuity between primary and secondary schools. In order to understand an artifact’s authority and to unravel its role in processes of innovation, we turned to organizational routines and neo-institutional theory. Drawing on data from an artifact analysis and semi-structured interviews, this article reports how this artifact not only transfers data, but also changed the discursive interactions (routines) in the school team around care. From an institutional perspective, implementing the artifact can be viewed as an answer to institutional forces that are pressurizing organizations to conform to particular ideas of what care and care continuity should ideally look like. The use of the artifact contributed to the schools’ organizational legitimacy by serving their symbolic needs and it enabled them to position themselves towards stakeholders, parents and other schools as a truly legitimate school.     

The Effect of Using a Visual Representation Tool in a Teaching-Learning Sequence for Teaching Newton’s Third Law

This paper presents a research-based teaching-learning sequence (TLS) that focuses on the notion of interaction in teaching Newton’s third law (N3 law) which is, as earlier studies have shown, a challenging topic for students to learn. The TLS made systematic use of a visual representation tool—an interaction diagram (ID)—highlighting interactions between objects and addressing the learning demand related to N3 law. This approach had been successful in enhancing students’ understanding of N3 law in pilot studies conducted by teacher-researchers. However, it was unclear whether teachers, who have neither been involved with the research nor received intensive tutoring, could replicate the positive results in ordinary school settings. To address this question, we present an empirical study conducted in 10 Finnish upper secondary schools with students (n?=?261, aged 16) taking their mandatory physics course. The study design involved three groups: the heavy ID group (the TLS with seven to eight exercises on IDs), the light ID group (two to three exercises on IDs) and the no ID group (no exercises on IDs). The heavy and light ID groups answered eight ID questions, and all the students answered four questions on N3 law after teaching the force concept. The findings clearly suggest that systematic use of the IDs in teaching the force concept significantly fostered students’ understanding of N3 law even with teachers who have no intensive tutoring or research background.     

The Independence of Research—A Review of Disciplinary Perspectives and Outline of Interdisciplinary Prospects

Minerva - The independence of research is a key strategic issue of modern societies. Dealing with it appropriately poses legal, economic, political, social and cultural problems for society, which...     

Consolidating Pre-service Physics Teachers’ Subject Matter Knowledge Using Didactical Reconstructions

In the Department of Physics, University of Helsinki, there are advanced physics courses designed for the needs of pre-service physics teachers. The starting point is that after introductory and intermediate physics courses, pre-service physics teachers know laws and definitions but the knowledge is quite fragmented and does not form coherent wholes. Graphical tools called didactical reconstructions were developed to help pre-service physics teachers to consolidate their physics knowledge. The idea behind the reconstructions is that “new” physics knowledge is always constructed based on previous knowledge (quantities, laws, theory). This means that every new concept is connected to previous concepts when it is formed; this is captured in the didactical reconstruction of processes. Then, when the knowledge is further constructed, the formed concept will be connected to other new concepts. This approach leads to the didactical reconstruction of structure: networks of quantities and laws, where the experiments and models construct the connections between quantities and laws. Here an overview and summary of the educational approach based on the didactical reconstruction is given for the first time. The results of the previously reported case studies show that the didactical reconstructions help students to connect the knowledge pieces into meaningful and more coherent wholes. These didactical reconstructions are now an integral part of our pre-service physics teacher education.