The Effects of Stress Tensor Fluctuations upon Focusing

We treat the gravitational effects of quantum stress tensor fluctuations. An operational approach is adopted in which these fluctuations produce fluctuations in the focusing of a bundle of geodesics. This can be calculated explicitly using the Raychaudhuri equation as a Langevin equation. The physical manifestation of these fluctuations are angular blurring and luminosity fluctuations of the images of distant sources. We give explicit results for the case of a scalar field on a flat background in a thermal state.Comment: 26 pages, 1 figure, new material added in Sect. III and in Appendices B and

Bekæmpelse af trafikulykker

Erindringer fra Sekretariatet for Sikkerhedsfremmende Vejforanstaltninger (SSV) (1974-1990). &nbsp

Classroom dialogue and digital technologies: A scoping review

AbstractThis article presents a systematic scoping review of the literature focusing on interactions between classroom dialogue and digital technology. The first review of its type in this area, it both maps extant research and, through a process of thematic synthesis, investigates the role of technology in supporting classroom dialogue. In total, 72 studies (published 2000–2016) are analysed to establish the characteristics of existing evidence and to identify themes. The central intention is to enable researchers and others to access an extensive base of studies, thematically analysed, when developing insights and interpretations in a rapidly changing field of study. The discussion illustrates the interconnectedness of key themes, placing the studies in a methodological and theoretical context and examining challenges for the future.</jats:p

Olympic Planning, Profit, and Participation: Towards a Children’s rights-based Approach to Sport mega-event Research?

It is well-established that sport mega-events remain highly relevant sites of enquiry for sociologists of leisure. Whereas sport mega-events are associated with a range of diverse and (un-)intended socio-spatial impacts, they can also have transformative impacts on children and young people. Against this backdrop, this article discusses the inter-relationship between sport mega-events and young people. By focusing predominantly on Olympic planning, participation and profits – which we call the ‘3Ps’ – we argue that researchers may turn towards research methodologies that are underpinned by children’s rights principles and which increasingly voice the perceptions of children and young people on the social impacts of sport mega-events. At the same time, we also reflect on exactly how children’s rights-based methodologies in this context can push the boundaries of the sociology of leisure, events and sport. In this sense, we contend that this article makes an important contribution to the academic work on the nexus between sport mega-events and young people and to our understanding of mega-events’ social costs

The Duty of Engagement: An Analysis of the 2016 European Convention on an Integrated Safety, Security and Service Approach at Football Matches and Other Events

Safety and security concerns in the context of sporting events and, in particular, football, have existed for decades. This has led to responses from individual countries as well as on a supranational level through, for example, the Council of Europe (CoE) conventions. In this article, we critically analyse the CoE’s2016 Convention on an Integrated Safety, Security and Service Approach atFootball Matches and Other Sports Events (CETS, No.218). Hitherto, few analyses have concentrated on the scope and impacts of the Convention. Thus, this article first asks how contracting states should implement Article 8 of the Convention which enshrines a duty of engagement. Second, it questions how the Convention plays into the wider embrace of human rights in contemporary sport settings. The unfolding argument is that the Convention has been comparably under-researched within the literature on both human rights and sport mega-events and football-related legal analyses. Moreover, we argue that the Convention contains much potential for driving forward a more visible engagement with human rights law within a sporting context. In particular, Article 8, which enshrines a duty of engagement has the potential to foster a robust and transformative human rights compliant culture within the context of sport

On certain quasi-local spin-angular momentum expressions for small spheres

The Ludvigsen-Vickers and two recently suggested quasi-local spin-angular momentum expressions, based on holomorphic and anti-holomorphic spinor fields, are calculated for small spheres of radius $r$ about a point $o$. It is shown that, apart from the sign in the case of anti-holomorphic spinors in non-vacuum, the leading terms of all these expressions coincide. In non-vacuum spacetimes this common leading term is of order $r^4$, and it is the product of the contraction of the energy-momentum tensor and an average of the approximate boost-rotation Killing vector that vanishes at $o$ and of the 3-volume of the ball of radius $r$. In vacuum spacetimes the leading term is of order $r^6$, and the factor of proportionality is the contraction of the Bel-Robinson tensor and an other average of the same approximate boost-rotation Killing vector.Comment: 16 pages, Plain Te

Heart Angiotensin-Converting Enzyme and Angiotensin-Converting Enzyme 2 Gene Expression Associated With Male Sex and Salt-Sensitive Hypertension in the Dahl Rat

Angiotensin-converting enzyme 2 (ACE 2) in the heart including its sex dependency in the hypertensive heart, has not been much studied compared to ACE. In the present study, we used the Dahl salt-sensitive rat exposed to fructose and salt to model a hypertensive phenotype in males, females, and ovariectomized females. Blood pressure was measured by the tale-cuff technique in the conscious state. Expression of RAS-related genes ACE, ACE2, angiotensin II receptor type 1, Mas1, and CMA1 in the heart were quantified. The results revealed small but significant differences between male and female groups. The main results indicate the presence of a male preponderance for an increase in ACE and ACE2 gene expression. The results are in accordance with the role of androgens or male chromosomal complement in controlling the expression of the two ACE genes

Sport mega-event governance and human rights: the ‘Ruggie Principles’, responsibility and directions

In recent years, the discourses surrounding human rights and sport mega-events (SMEs) have grown immensely. These are often directed towards sport’s governing bodies responsible for the administration of these mega-events. Tapping into the growing scholarship, this article aims to advance the fields of sport, leisure and human rights. By reconsidering the commercial nature of sports’ governing bodies (focusing on IOC and FIFA), we argue that what is commonly referred to as the ‘Ruggie Principles’ both can and should be applied to FIFA and IOC’s practices and event-related operations. In this context, and by reflecting on the practical applications of human rights impact assessments in the context of sport governing bodies who are the awarding bodies of hosting rights, the paper argues that due diligence and human rights impact assessments should become an organisational mainstay of FIFA and IOC’s event-related operations. Whilst our normative argument can have implications for policy and practice, we also provide further directions for research in what remains a pivotal era of SMEs globally

Positive Mass Theorem for Black Holes in Einstein-Maxwell Axion-dilaton Gravity

We presented the proof of the positive mass theorem for black holes in Einstein-Maxwell axion-dilaton gravity being the low-energy limit of the heterotic string theory. We show that the total mass of a spacetime containing a black hole is greater or equal to the square root of the sum of squares of the adequate dilaton-electric and dilaton-axion charges.Comment: latex file, to appear in Classical Quantum Gravit

Further towards the right to ‘safe leisure’: a case study of the Council of Europe’s 2016 Saint-Denis Convention

In the context of the right to leisure – enshrined by the Universal Declaration of Human Rights (1948) – this article addresses how the Council of Europe’s (2016) Convention on an ‘Integrated Safety, Security and Service Approach at Football Matches and Other Sports Events’ (‘Saint-Denis Convention’) provides a legal pathway towards what we conceptualize here as the right to ‘safe leisure’. This right to ‘safe leisure’, we locate within broader right to leisure discourses which this article reconsiders. We contend that the Convention has wider ramifications for the intersection between human rights and leisure and that the Convention’s potential resides in the fact that it enhances the existing and orthodox conceptualizations of leisure. Following an unpacking and operationalization of the right to leisure, this conceptual article then showcases how the 2016 Convention enshrines distinct duties and obligations which establish a clear right to ‘safe leisure’ within a significant realm of leisure life