Scattering of massive scalars by Schwarzschild black holes

The Klein-Gordon equation for the wave function of a single massive scalar is written in spherical and parabolic coordinates in the presence of a Schwarzschild background, and some semi-classical techniques for deriving asymptotic results are considered. In addition to the well-known logarithmic phase shift due to the tortoise radial coordinate, it is found that there is a mass-dependent logarithmic phase shift at infinity. This is found to be necessary to match the Newtonian cross-section in the non-relativistic limit. Finally, by imposing suitable boundary conditions near the horizon, the phase shift is calculated.Comment: 8 pages, 3 figure

Light Hadron Spectroscopy on Coarse Lattices with O(a^2) Mean-Field Improved Actions

The masses and dispersions of light hadrons are calculated in lattice QCD using an O(a^2) tadpole-improved gluon action and an O(a^2) tadpole-improved next-nearest-neighbor fermion action originally proposed by Hamber and Wu. Two lattices of constant volume with lattice spacings of approximately 0.40 fm and 0.24 fm are considered. The results reveal some scaling violations at the coarser lattice spacing on the order of 5%. At the finer lattice spacing, the calculated mass ratios reproduce state-of-the-art results using unimproved actions. Good dispersion and rotational invariance up to momenta of pa ~ 1 are also found. The relative merit of alternative choices for improvement operators is assessed through close comparisons with other plaquette-based tadpole-improved actions.Comment: 17 page RevTeX manuscript. 7 Figures. This and related papers may also be obtained from http://www.physics.adelaide.edu.au/~dleinweb/Publications.htm

A Foucauldian analysis on the professionalisation effort of nursing in Singapore

Aim: A discussion using Foucault’s genealogical analysis to explain the professionalisation effort of nursing in Singapore. Background: Nursing in Singapore is strongly influenced by Western civilisation, however, the discipline may not have adopted similar responses to the world’s nursing professionalisation agenda as led by the West. An explanation on the ways nursing is spoken of and practiced in Singapore provides insights to the effects on nursing development in the country. Design: The discussion uses Foucault’s genealogy of power to draw on the practices of clinical nursing and nursing education in Singapore in an attempt to uncover the unorthodox professionalisation effort. Data Sources: The discussion is an outcome of a critical reflective observation made by the authors between 1993 and 2014. It is supported by related literature, critical debates amongst Singapore healthcare professionals, nurse lecturers and the Singapore locals. Implications for Nursing: Time and effort vested in overcoming medico-political dominance, should be used in the pursuit of high quality nursing clinical knowledge and acumen. Specialised nursing knowledge and autonomous practice should adopt an explicit focus in its mission to achieve the common good which is in favour of the public interest. Conclusions: While the hierarchical nursing structure was the foundation for professionalising nursing, nursing subservience was the gateway for advancing nursing in Singapore. Without generalising the positive effects of the power-relations in Singapore, nursing practice which reflected the ‘subservience in females’ and demonstrated respect for authority within a hierarchical system had evidently led to good quality nursing practices which serve as a strong foundation for nursing to secure professional recognition

Selective Population of Edge States in a 2D Topological Band System

We consider a system of interacting spin-one atoms in a hexagonal lattice under the presence of a synthetic gauge field. Quenching the quadratic Zeeman field is shown to lead to a dynamical instability of the edge modes. This, in turn, leads to a spin current along the boundary of the system which grows exponentially fast in time following the quench. Tuning the magnitude of the quench can be used to selectively populate edge modes of different momenta. Implications of the intrinsic symmetries of Hamiltonian on the dynamics are discussed. The results hold for atoms with both antiferromagnetic and ferromagnetic interactions.Comment: 7 pages (expanded Supplemental Material

Let\u27s make a harbor into a harbor : an environmental history of Bellingham Bay

Bellingham Bay is a rich environment that has been appreciated by geologists, geographers, biologists as well as other academics from the natural sciences. This thesis highlights many of these scholarly approaches, but adds a human element to the history of this harbor. Special attention is paid to the underwater landscape of the Bay because different groups of people have tried to control this feature of the Bay and embed various social constructions into the physical geography. More importantly, differing ideas about the Bay and how it should be managed and altered have brought different groups into conflict. These conflicts make up the bulk of this interpretation. I argue that social scientists have failed to appreciate the relationship between human history and the natural environments below the surface of coastal areas

A glimpse into nursing discursive behaviour in interprofessional online learning

Background: The importance of interprofessional learning to provide quality patient care has resulted in the increasing use of asynchronous computer mediated conferencing in healthcare programmes within universities. The asynchronicity based on typed-written discussions in a virtual learning environment which provided flexibility in learning was used to increase opportunities for nurses and other allied healthcare professionals to participate in interprofessional learning in higher education. However, successful online learning relies on discursive practices in the virtual learning environment, embedded within discursive exchanges in practice are power relations in nursing language use; which had a negative impact on interprofessional learning and working relationships amongst nurses, between nurses and other allied healthcare professionals. This paper presents an analysis of the discursive practices of registered nurses in interprofessional learning based on asynchronous computer mediated conferencing. It aimed to ascertain if power relations were implicit in nursing language. Methods: Fairclough’s critical discourse analysis was used to analyse eight hundred and ninety typewritten online messages created in a 100% text-based online learning module at Master’s level in a University in North England between September 2004 and September 2009. Although the messages were created by 9 registered nurses and 4 other allied healthcare professionals undertaking interprofessional learning to learn about the issues surrounding e-learning in healthcare settings, this paper is part of a larger study focused on the messages by the nurses. Results: Nurses’ messages tended to appear as the first few responses in the discussion threads and their language was formal and objectifying. The genres resembled those found either in written assignment within higher education or in nursing documentation within practice. The virtual learning environment was an alternative social space for clinical practice where dominance of nurses was created, maintained and reinforced. Conclusions: Existing literature highlighted the incidents of problematic issues of interprofessional learning. In contrast, this paper explains the way nurses, through discursive practices, construct themselves in relation to their nursing and allied healthcare colleagues. Nurses need to be aware of the power-relations embedded in their language use and future research could usefully focus on the discursive aspect of interprofessional learning