Impaired pulmonary and cardiac function after maximal exercise

The cardiopulmonary response to maximal rowing exercise of short duration was studied in six healthy well-trained oarsmen. The lung diffusing capacity for carbon monoxide was significantly decreased below the pre-exercise value for 2.5 days post-exercise (P less than 0.05). Residual volume (RV) showed a significantly increased value at 30 min of recovery (P less than 0.01) with no change in total lung capacity. There was no significant change in transthoracic electrical impedance following exercise but a decrease may have been masked by the increased RV. The changes in the pulmonary parameters may reflect the occurrence of a transient interstitial lung oedema. Exercise-induced bronchoconstriction may be a part of the cardiopulmonary response as peak expiratory flow rate (PEFR) was significantly reduced at 30 min of recovery. The reason for the increase in pulmonary extravascular water volume may be a marked distension of the lung capillaries due to increased blood volume in the lungs and as a consequence increased vascular permeability. The changes may also be caused by impaired myocardial contractility indicated by a split impedance dZ/dt waveform, not previously described in healthy persons, which occurred in all six subjects immediately following exercise.     

‘Alternative’ universities revisited: A study of the distinctiveness of universities established in the spirit of 1968

Abstract

In the late 60s and early 70s, several universities were set up in various European countries with the intention of providing an alternative to established institutions of higher education. The new universities were expected, amongst other things, to experiment with new forms of leadership and management internally, give teaching and learning higher priority, and to be regional relevant institutions for the area in which they were located. The paper analyses to what extent three such university establishments: Aalborg University in Denmark, Maastricht University in the Netherlands and Troms?University in Norway have managed to maintain and develop their alternative profile during the last thirty years. The study suggests that even though the universities in some areas have adapted to environmental pressure, they have managed to keep their profile as innovative and alternative.     

The importance of communication in teaching: A systems-theory approach to the scaffolding metaphor

Scaffolding as a metaphor for support of learning processes places focus on the relationship between the psychic and social aspects of those processes. This paper examines the conceptualization of this relationship in activity theory and in operational constructivism. The importance of a distinction between psychic processes, language and communication is especially emphasized and discussed in relation to understandings of empathy, inter-subjectivity, and distributed cognition.     

Measuring Children's Age Stereotyping Using a Modified Piagetian Conservation Task

We examined five-year-old-children's age stereotyping using a modified Piagetian conservation task. Children were asked if two lines of objects were the “same” after one line had been made longer (transformed). A conversational account posits that children's answers reflect assumptions about the asker's motivation for the question (Schwarz, 1996 Schwarz , N. ( 1996 ). Cognition and communication: Judgmental biases, research methods, and the logic of conversation . Mahwah , NJ : Lawrence Erlbaum . [Google Scholar]). We reasoned that when asked by a young adult (puppet Experiment 1, experimenter Experiment 2) children would assume the question is to ascertain if they have noted a perceptual change and would provide answers focused on the change (length). If older adults are assumed to be in decline because of negative age stereotyping, however, children may assume an older adult (puppet, experimenter) is seeking clarification about line equality and would, therefore, give responses focused on the similarity of the lines (number). The expectation that a focus on length or number should differ across puppet/experimenter conditions was supported in both experiments and provides behavioral evidence for children's old age stereotyping.     

The importance of being elastic: Deflection of a badminton racket during a stroke

Abstract

The deflection profiles of a badminton racket during strokes performed by elite and world-class badminton players were recorded by strain gauges and subsequently analysed to determine the role of shaft stiffness in racket performance. Deflection behaviour was consistent in all strokes across all players, suggesting a controlled use of racket elasticity. In addition, all impacts occurred within 100 ms of each other, a duration in which deflection velocity provides an increase in racket velocity, indicating that the players were able to use racket elasticity to their advantage. Since deflection behaviour is a product of the racket–player interaction, further work is required to determine the effects of different racket properties and player techniques on the elastic response of rackets during strokes.     

Electromyographic Patterns During Level and Inclined Treadmill Running and Their Relationship to Step Cycle Measures

Abstract

Eight highly skilled male distance runners were filmed while running on level and inclined treadmills. During the filming sequence, EMG measurements were collected on vastus medialis (VM) and semimembranosus (SM) of the right thigh. The initiation and duration of electrical activity of the two muscles was extracted from the recordings relative to the step cycle events. Analysis of covariance for repeated measures was utilized as a statistical treatment to examine the effect of treadmill grade (– 10%, 0%, and + 10%) upon step cycle and EMG data. Results indicate that treadmill grade had a significant effect on the relative duration of both stance and swing phases of the running step cycle and total step cycle duration. Total step cycle time and relative swing phase duration decreased as the treadmill grade was changed from a negative grade to a zero grade to a positive grade while the duration of the stance phase increased. EMG measures indicated decreases in relative duration of SM activity during the stance phase progressing from negative grade to zero grade to positive grade while an increase in SM activity was noted during the swing phase. VM activity during stance was longest in negative grade running, decreased in level grade running, and increased again in positive grade running.     

Plant hormones in war and peace. Science, industry, and government in the development of herbicides in 1940s America

This essay describes the emergence of "hormone" herbicides from academic plant physiology research in America in the late 1930s and 1940s, attending especially to the role of interactions between university scientists, industrial concerns, and government (particularly agricultural) agencies. The importance of an intellectual shift among the physiologists to viewing hormones as plant toxins rather than growth stimulators, spurred by wartime events, is discussed. The essay concludes by exploring the postwar marketing of these hormones as agrichemicals and as lawn treatments for suburban consumers, placing these in the economic and ecological context of other contemporary developments in farming technique.     

A characterization of a unified notion of mathematical function: the case of high school function and linear transformation

In this paper, we draw on the contemporary perspective of inclusive materialism offered by de Freitas and Sinclair to contribute to current discussions on the role of the body in the learning of mathematics. Using the notions of distributed agency and assemblage, we illustrate the way in which three students engage with a patterning task. We discuss this as an example to show how the mathematics activity involves, besides the students’ bodies, other materialities that populate the classroom, and how all the human and non-human bodies form a moving assemblage that constantly reconfigures and reorients learning. The inclusive materialism helps us talk about learning as a dynamic assemblage rather than in terms of individual achievements and directs attention to the material learning environment.     

Didactising: Continuing the work of Leen Streefland

In this paper we present three cases of instructional design that illustrates both horizontal didactising, the activity of using already established principles to design instruction, and vertical didactising the activity of developing new tools and principles for instructional design. The first case illustrates horizontal didactising by elaborating how the constructs chains of signification and models were used to design an instructional sequence involving linear growth. The second and third cases illustrate vertical didactising by developing argumentation analyses and generative listening, respectively, as instructional design tools. In the second case, argumentation analyses emerge as a tool that other designers can use to anticipate the quality of conversations that can occur as students engage in tasks prior to implementing the instructional sequence. The third case develops the notion of generative listening as a conceptual tool within the context of designing differential equations instruction to gain insights into what are, for students, experientially-real starting points that are mathematical in nature and to provide inspirations for revisions to instructional sequences. This revised version was published online in August 2006 with corrections to the Cover Date.