The “manifest destiny” of the performing arts by A. Peacock

Journal of Cultural Economics -     

Adaptive progressive download based on the MPEG-4 file format

In this paper we describe how progressive download and adaptive streaming can be combined into a simple and efficient streaming framework. Based on the MPEG-4 file format (MP4) we use HTTP for transport and argue that these two components are sufficient for specifying an open streaming architecture. The client selects appropriate chunks from the MP4 file to be transferred based on (1) the header information (i.e. the "moov" box) in the first part of the file and (2) his observation of network throughput. The framework is completely client driven which allows for better server scalability and reduces signalling overhead. We discuss architecture and implementation issues such as complexity, interoperability and scalability and compare to 3GPP PSS Re1-6 adaptive streaming when appropriate. Measurements from a simple MP4/HTTP streaming client are presented showing that appropriate chunks are selected such that increased reliability is achieved.     

Adaptive progressive download based on the MPEG-4 file format

In this paper we describe how progressive download and adaptive streaming can be combined into a simple and efficient streaming framework. Based on the MPEG-4 file format (MP4) we use HTTP for transport and argue that these two components are sufficient for specifying an open streaming architecture. The client selects appropriate chunks from the MP4 file to be transferred based on (1) the header information (i.e. the “moov” box) in the first part of the file and (2) his observation of network throughput. The framework is completely client driven which allows for better server scalability and reduces signalling overhead. We discuss architecture and implementation issues such as complexity, interoperability and scalability and compare to 3GPP PSS Rel-6 adaptive streaming when appropriate. Measurements from a simple MP4/HTTP streaming client are presented showing that appropriate chunks are selected such that increased reliability is achieved.     

Authorship order

Considering the fact that authorship order plays such a significant role as a basis for scientific merit, this paper looks into the practices of authorship order from a research ethical perspective. We conclude that there is a wide variety of practices and no common understanding of what the different authorship positions signify. Authorship guidelines do not provide much help. We recognize that, regardless of what system for valuing authorship positions is used, it will be misleading and unfair in most applications because relative contributions vary in ways that are not captured by fixed value assignments to authorship positions. In theory, assigning percentage figures reflecting the relative contributions of the authors would solve that problem, but we argue that such a scheme is not likely to work in practice. It can also be questioned whether relative, rather than absolute, contributions should be the basis for scientific merit. Contributorship is discussed as an alternative, but is recognized to be insufficient both in communicating absolute and relative contributions, as standardly used. However, there may be a way forward with contributorship, but then, the level of detail needs to increase considerably and its application be standardized.     

Regulation and deregulation in education policy: new reforms and school sports in Swedish upper secondary education

During the 1990s, neoliberal reforms in Sweden increased local school actors' possibilities to develop school profiles regarding both organization and content. This restructuring has increased the total number of school sports programs as well as the possibilities for upper secondary schools and sports clubs to develop elite and amateur sports on a local level. In a new educational reform, the Swedish Government criticizes parts of the Swedish school sports system. The Government believes that the majority of local school sports programs and courses obstruct the maintenance of national equivalence, that upper secondary schools use school sports to attract pupils for economic reasons and that some pupils involved in school sports may fail to reach the academic or vocational goals of regular upper secondary education. Using critical discourse analysis, the present paper illustrates how educational policies are linked to wider symbolic meaning systems in an attempt to legitimize, define and organize upper secondary schools and to characterize pupils as either eligible or ineligible to participate in school sports. The analyses are based on various types of empirical data: policy documents, official letters from the sports movement on the government bill and in-depth interviews. The results indicate that the reform represents a shift in the policy rhetoric: from a normative rhetoric highlighting pupils' social and emotional reasons for choosing school sports, to a rational rhetoric emphasizing efficiency, standardization and regulation of pupils' educational choices. Using school sports as an example, the paper shows how the main aim of the reform—to raise educational standards and maintain national equivalence—is achieved through social differentiation, meaning that pupils with the right performance indicators are selected for participation in programs to which they are suited.     

Eine generische Komponente zur rechnergestützten Nutzung von Aufbauorganisationen

Zusammenfassung.   Die klassische Unterscheidung zwischen Aufbau- und Ablauforganisation eines Unternehmens deutet auf eine getrennte rechnergestützte Realisierung dieser beiden fundamentalen Komponenten einer Organisation hin. Dieser Beitrag unterstützt diese These, verweist aber gleichzeitig auf die integrierende Bedeutung einer rechnergestützten Aufbauorganisationsverwaltung, welche unterschiedliche Realisierungsformen der Ablauforganisation (unter anderem workflow-management und eCommerce) bedient. Die generelle Konzeption und Umsetzung einer solchen Aufbauorganisationsverwaltung wird in diesem Beitrag vorgestellt. Eingegangen am 14. Februar 2000 / Angenommen am 31. Mai 2000     

A proficiency model for pre-service physics teachers' pedagogical content knowledge (PCK)—What constitutes high-level PCK?

This study identifies proficiency levels in pre-service physics teachers' pedagogical content knowledge (PCK) and reveals how teacher education can promote transitions into higher proficiency. Teacher education plays a fundamental role in supporting pre-service teachers' PCK development. Proficiency levels are a powerful source when evaluating this PCK development because they characterize what learners are likely to be able to know on a specific level. Previous research has presented a model of proficiency levels in pre-service physics teachers' PCK; however, evidence for the model's validity is still lacking. According to the Refined Consensus Model of PCK, factors such as teachers' content knowledge (CK), their teaching experience, and their beliefs about teaching and learning science promote PCK development. Thus, understanding how and when pre-service physics teachers' CK, teaching experience, and beliefs contribute to their proficiency can bring insights into how teacher education can promote PCK development. To address this issue, N = 427 observations of pre-service physics teachers were analyzed. Utilizing the scale anchoring procedure, four different proficiency levels in pre-service physics teachers' PCK were identified. Analyzing these proficiency levels showed that lower levels can be characterized as remembering content-unspecific knowledge, whereas higher levels encompass content-specific strategies to structure and elaborate lessons. Additionally, logistic regression models revealed that pre-service physics teachers' CK is crucial for an increase in PCK proficiency. However, transitions into higher levels of PCK additionally require teaching experience and adequate beliefs about teaching and learning. Thus, our proficiency levels can be used to bring insights into how proficiency in PCK can be supported during teacher education. For example, teacher education should provide courses focusing on the science curriculum and the assessment of student learning to promote pre-service physics teachers' progression in PCK.     

Unsteady flow phenomena in human undulatory swimming: a numerical approach

The undulatory underwater sequence is one of the most important phases in competitive swimming. An understanding of the recurrent vortex dynamics around the human body and their generation could therefore be used to improve swimming techniques. In order to produce a dynamic model, we applied human joint kinematics to three-dimensional (3D) body scans of a female swimmer. The flow around this dynamic model was then calculated using computational fluid dynamics with the aid of moving 3D meshes. Evaluation of the numerical results delivered by the various motion cycles identified characteristic vortex structures for each of the cycles, which exhibited increasing intensity and drag influence. At maximum thrust, drag forces appear to be 12 times higher than those of a passive gliding swimmer. As far as we know, this is the first disclosure of vortex rings merging into vortex tubes in the wake after vortex recapturing. All unsteady structures were visualized using a modified Q-criterion also incorporated into our methods. At the very least, our approach is likely to be suited to further studies examining swimmers engaging in undulatory swimming during training or competition.     

Alterations in Body Size and Composition Consequent to Astro-Trimmer and Slim-Skins Training Programs

Tennis is an activity requiring both endurance and anaerobic components, which could have immunosuppressive effects postexercise.

Purpose

The purpose of this investigation was to determine the effect of a simulated tennis match on apoptotic and migratory markers on lymphocyte subsets.

Method

Male high school (n = 5) and college (n = 3) tennis players (M _age = 18.9 ± 3.3 years) completed 10 sets of a tennis protocol including serves, forehand strokes, and backhand groundstrokes with 1-min rest periods between sets. Apoptosis antigen 1 receptor (CD95) and chemokine receptor fractalkine (CX₃CR1) expression was analyzed on helper T lymphocytes (CD4+), cytotoxic T lymphocytes (CD8+), and B lymphocytes (CD19+) twice, at resting baseline and immediately after all 10 sets of the tennis protocol.

Results

An increase was observed in each lymphocyte subtype (p < .02, effect size = .41), and comparison of absolute changes revealed increases in CD4+/CD95+, CD8+/CD95+, and CD8+/CX₃CR1 lymphocytes following the tennis protocol (p < .01, effect size = .43), but not in CD19+ cells.

Conclusions

A simulated tennis match has adequate intensity to induce immune modulations in terms of increased cell death and cellular migration in T lymphocyte subsets. Lymphocytopenia following tennis play is influenced by both apoptotic and migratory mechanisms.