452 research outputs found
Generalized embedding variables for geometrodynamics and spacetime diffeomorphisms: Ultralocal coordinate conditions
We investigate the embedding variable approach to geometrodynamics advocated
in work by Isham, Kucha\v{r} and Unruh for a general class of coordinate
conditions that mirror the Isham-Kucha\v{r} Gaussian condition but allow for
arbitrary algebraic complexity. We find that the same essential structure
present in the ultralocal Gaussian condition is repeated in the general case.
The resultant embedding--extended phase space contains a full representation of
the Lie algebra of the spacetime diffeomorphism group as well as a consistent
pure gravity sector.Comment: 16 page
Yang-Mills Flow and Uniformization Theorems
We consider a parabolic-like systems of differential equations involving
geometrical quantities to examine uniformization theorems for two- and
three-dimensional closed orientable manifolds. We find that in the
two-dimensional case there is a simple gauge theoretic flow for a connection
built from a Riemannian structure, and that the convergence of the flow to the
fixed points is consistent with the Poincare Uniformization Theorem. We
construct a similar system for the three-dimensional case. Here the connection
is built from a Riemannian geometry, an SO(3) connection and two other 1-form
fields which take their values in the SO(3) algebra. The flat connections
include the eight homogeneous geometries relevant to the three-dimensional
uniformization theorem conjectured by W. Thurston. The fixed points of the flow
include, besides the flat connections (and their local deformations), non-flat
solutions of the Yang-Mills equations. These latter "instanton" configurations
may be relevant to the fact that generic 3-manifolds do not admit one of the
homogeneous geometries, but may be decomposed into "simple 3-manifolds" which
do.Comment: 21 pages, Latex, 5 Postscript figures, uses epsf.st
Physicians' perspectives on the treatment of patients with eating disorders in the acute setting
Abstract Background Hospitalisation for an eating disorder is rare, however treatment in the acute medical setting can be a life-saving admission. While the multidisciplinary team delivers overall patient care, medical decisions are the responsibility of the treating physicians. Treatment decisions directly impact on patient care and outcomes. This study aimed to explore the considerations that influence the medical decisions of physicians when treating patients with eating disorders in the acute setting. Method Semi-structured interviews were conducted with ten medical physicians who had previously treated eating disorders on a general medical unit in two Australian tertiary hospitals. An interview schedule, based on the literature and four relevant domains from the Consolidated Framework for Implementation Research, was developed. Interviews were audio recorded, transcribed verbatim and analyzed thematically. Coding and interim themes and sub-themes were developed by two dietitian researchers; these were further refined through researcher discussion and triangulation with two additional dietitian researchers. Results Ten doctors were interviewed (3 consultants (1 adult general medical and 2 paediatricians: 13â16âyears medical experience), 2 registrars (4â7âyears experience), 1 resident (1âyear experience), and 4 interns (<â1âyear experience). Doctors described memorable patient cases, related to hospital stays over several weeks. Interviews ranged in length from 58âmin to 91âmin. Four themes (with five sub-themes) were developed: 1) navigating uncertainty (focusing on processes and goals and seeking information), 2) being âthe good doctorâ (doing the right thing), 3) seeing the big picture (depending on key players and considering short and long-term), and 4) involving family and patient. Conclusions Non-specialist physicians described challenges in the treatment of eating disorders in the inpatient setting. They take a holistic approach that considers both short and longer-term goals, relying on specialist colleagues, the wider multidisciplinary team and sometimes family members to guide treatment decisions during admissions on general medical wards. Additional support, education and training centered on the key themes may increase physiciansâ confidence and ability to make effective treatment decisions for this patient group. The results are relevant to all health professionals working in this field to better understand the priorities of medical physicians and to support them to achieve positive outcomes in the inpatient treatment of patients with eating disorders
A Kucha\v{r} Hypertime Formalism For Cylindrically Symmetric Spacetimes With Interacting Scalar Fields
The Kucha\v{r} canonical transformation for vacuum geometrodynamics in the
presence of cylindrical symmetry is applied to a general non-vacuum case. The
resulting constraints are highly non-linear and non-local in the momenta
conjugate to the Kucha\v{r} embedding variables. However, it is demonstrated
that the constraints can be solved for these momenta and thus the dynamics of
cylindrically symmetric models can be cast in a form suitable for the
construction of a hypertime functional Schr\"odinger equation.Comment: 5 pages, LaTeX, UBCTP-93-02
Management of tuberculosis by healthcare practitioners in Pakistan: A systematic review
Objective: To assess the quality of tuberculosis (TB) care in Pakistan, through determining comparison of healthcare practitionersâ knowledge and practices to national and international TB care guidelines. Methods: Studies reporting on knowledge, attitudes and practices of public and private practitioners with TB patients were selected through searching electronic databases and grey literature. Findings: Of 1458 reports, 20 full-texts were assessed, of which 11 met the eligibility and quality criteria; all studies focused on private sector care. Heterogeneity precluded meta-analysis. In 3 of 4 studies, over 50% of practitioners correctly identified a cough as the main TB symptom. However, 4 out of 6 studies showed practitionersâ compliance to be low (under 50%) for the use of sputum microscopy in diagnosis. The poorest quality care occurred in the later stages of treatment, with low compliance in prescribing practices for continuation-phase care and in monitoring and recording treatment progress, the latter of which is particularly critical for treatment success. Conclusion: TB care was variable and generally inadequate, with both a lack of knowledge and a small âknow-doâ gap evidentâpractitioners did not use methods that they know they should use. A lack of recent evidence found suggests that the quality of current practices may not be fully captured and further research is needed, especially on non-allopathic, rural and public-sector contexts. Improved training of practitioners, greater availability of recommended diagnostic tools and expansion of public-private partnerships are suggestions for improving the quality of TB care in Pakistan
Somewhere in Europe (1947): locating Hungary within a shifting geopolitical landscape
Somewhere in Europe/Valahol EurĂłpĂĄban (RadvĂĄnyi, 1947) was one of the first films made in Hungary after 1945. Financed by the Hungarian Communist Party (MKP), it loudly proclaimed a broad European pertinence in an effort to privilege the universal narrative of childhoods disrupted by the war over narrowly national political concerns. The filmâs story of a gang of half-starved children battling for survival in a bombed-out Central European landscape places it squarely within a transnational post-war film-making tradition. Similarities with both Italian neorealism and Soviet socialist realist cinema indicate a shared European experience of the war, but is also attributable to the international training and experience of the filmâs personnel. The director RadvĂĄnyi had worked in the Italian industry, while the scriptwriter was the well-known film theorist BĂ©la BalĂĄzs, who had worked in Weimar Germany and Soviet Russia. This article argues that in spite of its ostensible commitment to a communist and humanist ideology, the film gives an insight into the Hungarian national obsession with territorial integrity. Hungaryâs participation in World War II on the side of the Axis, and its position as a defeated nation under Allied occupation, are seen to complicate the film text. This article contends that in spite its transnational flavour, the filmâs focus on lost children wandering a borderless Europe suggests a preoccupation with the countryâs uncertain position within a shifting geopolitical landscape. In turn, the filmâs official reading by NemeskĂŒrty shows an eagerness to accept the filmâs representation of Hungary as a blameless victim of the war, and gives evidence of a need to insert a (false) break between the countryâs wartime past as a member of the Axis, and the countryâs 1968 present as a member of the Communist world order
Application of multireïŹection grazing incidence method for stress measurements in polished AlâMg alloy and CrN coating
Multi-reïŹection grazing incidence geometry, referred to as MGIXD, characterized by a small and constant incidence angle, was applied to measure low surface stresses in very thin layers of AlâMg alloy and CrN coating. These two materials were selected in order to deal with the low and high levels of residual stress, respectively. The inïŹuence of different mechanical treatments on residual stresses was studied for AlâMg samples. It was found that both rolling and mechanical polishing inïŹuence the distribution and amplitude of residual stress in surface layers. In the case of CrN coating, a very high compressive stress was generated during the deposition process. The stress distributions determined by the MGIXD method is in good agreement with the classic sin2 technique results for all studied samples. In performing stress measurements for a powder sample, it was found that the application of the Göbel mirror in the incident beam strongly reduces statistical and misalignment errors. Additionally, the root mean square values of the third order lattice strain within diffracting grains were determined
Using 3D Stringy Gravity to Understand the Thurston Conjecture
We present a string inspired 3D Euclidean field theory as the starting point
for a modified Ricci flow analysis of the Thurston conjecture. In addition to
the metric, the theory contains a dilaton, an antisymmetric tensor field and a
Maxwell-Chern Simons field. For constant dilaton, the theory appears to obey a
Birkhoff theorem which allows only nine possible classes of solutions,
depending on the signs of the parameters in the action. Eight of these
correspond to the eight Thurston geometries, while the ninth describes the
metric of a squashed three sphere. It therefore appears that one can construct
modified Ricci flow equations in which the topology of the geometry is encoded
in the parameters of an underlying field theory.Comment: 17 pages, Late
Application of multireïŹection grazing incidence method for stress measurements in polished AlâMg alloy and CrN coating
Multi-reïŹection grazing incidence geometry, referred to as MGIXD, characterized by a small and constant incidence angle, was applied to measure low surface stresses in very thin layers of AlâMg alloy and CrN coating. These two materials were selected in order to deal with the low and high levels of residual stress, respectively. The inïŹuence of different mechanical treatments on residual stresses was studied for AlâMg samples. It was found that both rolling and mechanical polishing inïŹuence the distribution and amplitude of residual stress in surface layers. In the case of CrN coating, a very high compressive stress was generated during the deposition process. The stress distributions determined by the MGIXD method is in good agreement with the classic sin2 technique results for all studied samples. In performing stress measurements for a powder sample, it was found that the application of the Göbel mirror in the incident beam strongly reduces statistical and misalignment errors. Additionally, the root mean square values of the third order lattice strain within diffracting grains were determined
- âŠ