Existence of Spherical Initial Data with Unit Mass, Zero Energy, and Virial less than - 1/2 for the Relativistic Vlasov-Poisson Equation with Attractive Coupling

In a recent paper, Kiessling and Tahvildar-Zadeh proved that any classical solution of the relativistic Vlasov-Poisson equation with attractive coupling launched by spherically symmetric initial data with zero total energy and virial less than or equal to -1/2 will blow up in finite time. They left open whether such data exist. Subsequently, the question was raised whether any such data exist at all. In fact, the simplest conceivable ansatz, a nearly uniform ball of material centered at the origin with momenta directed inward, must have virial strictly larger than -1/2! In this brief note, we settle this issue by constructing two classes of such initial data

Recipe for Victory: The Fight for Hill 677 during the Battle of the Kap’yong River, 24-25 April 1951

During the night of 24–25 April 1951, the Second Battalion, Princess Patricia’s Canadian Light Infantry fought what became the most famous Canadian battle of the Korean War. Outnumbered and isolated, the Princess Pats repulsed wave after wave of attacking Chinese infantry from their positions atop Hill 677 overlooking the Kap’yong River Valley. Although a comparatively minor episode in the broader context of the Korean War, Canadian retention of Hill 677 made an important contribution to the Commonwealth victory at Kap’yong. More significantly, the fight for Hill 677 was clearly the most successful set-piece engagement fought by the Canadians in Korea. In recognition of their achievement, the Princess Pats were awarded the United States Presidential Unit Citation—the only Canadian unit ever to earn this distinction. Although clearly an important event for the Canadians, the fight for Hill 677 has received little scholarly attention in Canada. Commonwealth historians, in contrast, have been busy. Examining the action from the perspective of the New Zealand gunners who supported the Canadians, Ian MacGibbon suggested that artillery fire was the key to victory, and saved the beleaguered Patricias from certain defeat. Although supporting fire, including that from the Canadians themselves, was the single most important factor in the successful defence of Hill 677, it was by no means the only one. An operational analysis of the battle reveals that the Second World War experiences of the Patricias’ senior officers, the specialized nature of the battalion’s pre-battle training program, high morale, and the failure of the enemy to coordinate and press his attack also helped to make the Canadian stand possible

The Ethical Implications of Personal Health Monitoring

Personal Health Monitoring (PHM) uses electronic devices which monitor and record health-related data outside a hospital, usually within the home. This paper examines the ethical issues raised by PHM. Eight themes describing the ethical implications of PHM are identified through a review of 68 academic articles concerning PHM. The identified themes include privacy, autonomy, obtrusiveness and visibility, stigma and identity, medicalisation, social isolation, delivery of care, and safety and technological need. The issues around each of these are discussed. The system / lifeworld perspective of Habermas is applied to develop an understanding of the role of PHMs as mediators of communication between the institutional and the domestic environment. Furthermore, links are established between the ethical issues to demonstrate that the ethics of PHM involves a complex network of ethical interactions. The paper extends the discussion of the critical effect PHMs have on the patient’s identity and concludes that a holistic understanding of the ethical issues surrounding PHMs will help both researchers and practitioners in developing effective PHM implementations

Stacking the Deck? An Empirical Analysis of Agreement Rates Between Pro Tempore Justices and Chief Justices of California, 1977-2003

The chief justice of California is empowered to select a pro tempore justice when one or more of the court\u27s regular justices are absent. Chief Justice Rose Bird was accused of using this power to manipulate case outcomes. Contemporary scholarly investigations came to mixed conclusions. Bird\u27s successors have adopted the nondiscretionary method of alphabetical selection. The present study compares the agreement rates of temporary justices with Bird and with her two immediate successors, Malcolm Lucas and Ronald George. It finds evidence of vote bias for Bird, particularly in close cases and cases before April 1981. It does not find evidence of vote bias for Chief Justices Lucas or George, suggesting that a non-discretionary selection procedure should be formally required

Designing the Health-related Internet of Things: Ethical Principles and Guidelines

The conjunction of wireless computing, ubiquitous Internet access, and the miniaturisation of sensors have opened the door for technological applications that can monitor health and well-being outside of formal healthcare systems. The health-related Internet of Things (H-IoT) increasingly plays a key role in health management by providing real-time tele-monitoring of patients, testing of treatments, actuation of medical devices, and fitness and well-being monitoring. Given its numerous applications and proposed benefits, adoption by medical and social care institutions and consumers may be rapid. However, a host of ethical concerns are also raised that must be addressed. The inherent sensitivity of health-related data being generated and latent risks of Internet-enabled devices pose serious challenges. Users, already in a vulnerable position as patients, face a seemingly impossible task to retain control over their data due to the scale, scope and complexity of systems that create, aggregate, and analyse personal health data. In response, the H-IoT must be designed to be technologically robust and scientifically reliable, while also remaining ethically responsible, trustworthy, and respectful of user rights and interests. To assist developers of the H-IoT, this paper describes nine principles and nine guidelines for ethical design of H-IoT devices and data protocols

Graphs, free groups and the Hanna Neumann conjecture

A new bound for the rank of the intersection of finitely generated subgroups of a free group is given, formulated in topological terms, and very much in the spirit of Stallings. The bound is a contribution to (although unfortunately not a solution of) the strengthened Hanna Neumann conjecture.Comment: J. Group Theory (to appear