Root clustering for rational convex regions

We restrict the discussion of root clustering (exclusion) to rational convex regions. A region in this family is constructed as the intersection of an infinite number of half planes. The root clustering criterion involves the positivity of a set of polynomials with respect to the region's parameter.     

Stress, Sport und Beschwerdewahrnehmung

Sport and physical activity are attributed with a positive influence on stress induced complaints due to their overall positive effect on health. The buffering effect on stress has not yet been clearly shown and the findings are inhomogeneous. The following article examines the buffering effect of sport and physical activity on different types of psychological and physical complaints. Therefore, a study was conducted questioning 453 people (M?=?53.56 years; SD?=?11.31) about chronic stress (Perceived Stress Scale), physical complaints (Gießener Beschwerdebogen) and their subjective physical activities (Energy consumption through physical activity – e.g. Soccer or Jogging) and energy consumption – daily bike and walking activity). A buffering effect on nearly all types of complaints could be shown through physical activity, but not through lifestyle activities. Physical activity acts complaint reducing on people suffering from increased stress. A more differentiated examination of the physical activity behaviour, the stress perception and the type of complaints might contribute to clearer findings.     

Does endurance training improve red blood cell aging and hemorheology in moderate-trained healthy individuals?

ObjectiveTo examine the impact of a 6-week endurance training on red blood cell (RBC) aging and deformability of healthy participants to detect possible improved hemorheological and performance-related adaptations.MethodsA total of 31 participants (17 females and 14 males) performed a 6-week moderate training protocol (three 1-h running sessions per week at 70% of maximal heart rate). Blood was sampled before and after the training. RBCs from each participant were fractioned according to density and age into 4 RBC subfractions. Subfractions were examined for changes of RBC properties, including aging distribution, RBC deformability, RBC microparticles, and phosphatidylserine concentrations. RBC and plasma nitrite levels were measured as indicators of nitric oxide metabolism.ResultsAerobic performance, peak oxygen consumption, ventilatory thresholds, velocity at the aerobic–anaerobic threshold, and lactate at exhaustion improved after training. The relative amount of both young RBCs and old RBCs increased, and the amount of the main RBC fraction decreased. Phosphatidylserine externalization and RBC-derived microparticles decreased. Overall deformability expressed as shear stress required to achieve half-maximum deformation to theoretical maximal elongation index at infinite shear stress improved in unfractioned RBCs (p < 0.001). Nitrite decreased in total (p = 0.001), young (p < 0.001), main (p < 0.001), and old (p = 0.020) aged RBCs and in plasma (p = 0.002), but not in very old RBCs.ConclusionThese results indicate that non-endurance-trained healthy participants benefit from a regular moderate running training program because performance-related parameters improve and a younger RBC population with improved RBC properties is induced, which might support oxygen supply in the microcirculation.     

The dynamics of online learning at the workplace: Peer-facilitated social learning and the application in practice

Research stresses the importance of social components in learning. The social contact with peers and tutors stimulates reflection and supports higher processes of learning necessary for the internalisation and application of new knowledge. However, merely proposing opportunities for interaction does not necessarily lead to fruitful discussion and collaboration. Social presence and facilitation are key concepts for successful mutual learning. Both are represented in Murphy’s collaboration model; social presence forms the basis of collaboration on which discussions and co-construction of knowledge evolve. Facilitation supports the entire collaboration process. In this paper, an adjusted version of Murphy’s model was applied to analyse 1085 comments shared in an online course between career practitioners of a public employment service. The results show that without a dedicated tutor, learners can still be involved in collaborative learning and co-construction of new knowledge provided that the topic under discussion is highly relevant and controversial. Learners themselves take over social presence and facilitation activities, but less frequently than when a professional tutor facilitates discussions. Ex post summative evaluation revealed that only a few learners applied the gained knowledge in the long-term. As comparisons with related research suggest, higher facilitation support leading to a higher cognitive interaction with the learning could have better supported the transfer to practice.     

Exploring the lack of a disfluency effect: evidence from eye movements

An eye-tracking study with 60 native Swedish speakers (18–30 years) was conducted to investigate the positive effects on learning outcomes predicted by the disfluency effect. Subtle low-pass filtering was used as a disfluency manipulation and compared with a control condition using regular text. The text was presented on four separate text presentation screens (TPSs), and eye movements were recorded. A free recall task was given 25 min later, and working memory capacity (WMC) was assessed to test if it would moderate learning outcomes. The disfluency manipulation had no effect on learning outcomes, total reading times on words or lines, first- or second-pass reading on lines, or average fixation durations. Moreover, the disfluency effect was not moderated by students’ WMC or self-reported prior knowledge of the topic. However, an adaptation to the disfluency manipulation was found. Total reading times on both words and lines were shorter in TPS 1 and 2 in the disfluency condition compared with the control condition, whereas reading times were longer in TPS 3 and 4. It is discussed if failures to replicate the disfluency effect arise from material features, with positive adaptations to disfluency (i.e., higher effort investment) possibly requiring more comprehensive materials.     

The transformation of academic ideals: an Australian analysis

This article explores the role that universities play in shaping the relationship between academics and their work. Drawing on Miller and Rose's interpretation of our present era as being characterised by ‘Advanced Liberal’ governance, this article demonstrates how discourses seeking to govern academic labour enrol ideals about the academic and subjectify academic staff within strategies to govern their conduct. Entrepreneurial conceptions of ‘good’ academic conduct are valorised through such initiatives as performance evaluation, interdisciplinary research programmes and Graduate Certificates of university teaching and skills development. Drawing on the past literature and an analysis of three Australian public universities, this article proposes three ideals through which academics are enrolled into strategies to govern their conduct: ‘the career academic’, ‘the tribal academic’ and ‘the celebrity academic’. The centrality of an entrepreneurial sense of self within academic ideals contributes to the production of insidious effects within academic practices. The subjectification of academics, as entrepreneurial knowledge managers, may potentially produce strain within academics who fail to close the psychological distance between their self-perceptions and academic ideals. This article proposes that future investigations of the development of academic ideals and values should engage with an analysis of modes of self-government. The utility of self-government is explored in an analysis of the dynamic production of academic ideals within policies and programmes aimed at governing the behaviour of academic staff.     

Revealing the decision-making of dribbling in the sport of futsal

ABSTRACT

This study aimed to investigate why futsal players decide to dribble. For this purpose, we analysed 396 trials comprising the dribbles (n = 132), passes (n = 131) or shots (n = 133), performed by 70 male futsal players. Passing and shooting angles, and interpersonal distance, including their rates of change (velocity and variability), were regarded as measures of interpersonal coordination tendency and a comparison was made among dribbling, passing and shooting situations. In addition, the variables identified as constraints on deciding to dribble were analysed in relation to age categories, dribbling outcomes and futsal court zone. Results revealed that passing and shooting angles, and interpersonal distance showed higher variability in dribbling than in passing and shooting situations. The findings allowed us to conclude that decision-making on dribbling was influenced by the variabilities of passing angles as well as shooting and interpersonal distance, and that success in dribbling was affected by the variability of interpersonal distance. Such variabilities were interpreted concerning their meaning of risk and/or uncertainty in the execution of motor skills.     

Cognitive and socio-motivational aspects in learning with animations: there is more to it than ‘do they aid learning or not’

Animations have become a ubiquitous component of computer-based instruction. Despite their widespread use, however, the evidence concerning their effects on learning is rather ambiguous, suggesting that one needs to have a closer look at the conditions under which animations will aid learning. Accordingly, three sets of moderating variables were identified: (1) the degree of processing support that is used to enhance learning with animation, (2) the context in which the animation is being used (e.g., laboratory setting versus classroom), and (3) the domain that is illustrated by the animation. On the one hand, the studies reported in the current special issue investigate manipulations of these variables. On the other hand, the studies vary among each other with respect to these factors, thereby reflecting the enlarged range of current animation research.     

The acquisition of problem-solving skills in mathematics: How animations can aid understanding of structural problem features and solution procedures

In this paper the augmentation of worked examples with animations for teaching problem-solving skills in mathematics is advocated as an effective instructional method. First, in a cognitive task analysis different knowledge prerequisites are identified for solving mathematical word problems. Second, it is argued that so called hybrid animations would be most effective for acquiring these prerequisites, because they show the continuous transition from a concrete, but superficial problem representation to a more abstract, mathematical problem model that forms a basis for solving a problem. An experiment was conducted, where N = 32 pupils from a German high school studied either only text-based worked examples explaining different problem categories from the domain of algebra or worked examples augmented with hybrid animations. Learners with hybrid animations showed superior problem-solving performance for problems of different transfer distance relative to those in the text-only condition.     

'Well,I've Not Done Any Work Today. I Don't Know Why I Came to School'. Perceptions of Play in the Reception Class

The place of play in the education of young children has been the focus of much interest in the past. But the findings from this research project demonstrate that there remains a significant amount of confusion about the role that play has in young children's education. In particular we found that there is a clear distinction between the rhetoric and reality of play in the reception class. Further, there was evidence of real anguish for some early years workers who were failing to offer the play activities that they knew should be provided. These findings are particularly interesting at present, since the debate on the role of play has once again emerged as fundamental in the attempt to define a curriculum appropriate to the needs of the 3-6 year olds who, from the year 2000, will be required to work within the highly contentious Foundation Stage of the National Curriculum.