Geometric structures on loop and path spaces

Is is known that the loop space associated to a Riemannian manifold admits a quasi-symplectic structure. This article shows that this structure is not likely to recover the underlying Riemannian metric by proving a result that is a strong indication of the "almost" independence of the quasi-symplectic structure with respect to the metric. Finally conditions to have contact structures on these spaces are studied.Comment: Final version. To appear in Proceedings of Math. Sci. Indian Academy of Science

Relative cost-effectiveness of using a liquid human milk fortifier in preterm infants in the US

Objective: To estimate the cost-effectiveness of using a liquid human milk fortifier (LHMF) compared to a powdered human milk fortifier (PHMF) in preterm infants in the US from the perspective of third-party payers and parents. Methods: This was a decision modelling study using patient data obtained from a random- ized controlled trial comparing a LHMF with a PHMF in preterm infants, supplemented with additional data obtained by performing a chart review among 79% of the trial patients. The model estimated the cost-effectiveness of LHMF versus PHMF in US$at 2014/2015 prices. Results: More infants in the LHMF group were discharged home (92$10,497 per infant less in the LHMF group than the PHMF group ($240,928 versus$251,425). Conclusion: Using LHMF instead of PHMF in preterm infants enabled resources to be freed-up for alternative use within the system. There is no health economic reason why LHMF should not be used in preference to PHMF in the NICU

Surfaces immersed in su(N+1) Lie algebras obtained from the CP^N sigma models

We study some geometrical aspects of two dimensional orientable surfaces arrising from the study of CP^N sigma models. To this aim we employ an identification of R^(N(N+2)) with the Lie algebra su(N+1) by means of which we construct a generalized Weierstrass formula for immersion of such surfaces. The structural elements of the surface like its moving frame, the Gauss-Weingarten and the Gauss-Codazzi-Ricci equations are expressed in terms of the solution of the CP^N model defining it. Further, the first and second fundamental forms, the Gaussian curvature, the mean curvature vector, the Willmore functional and the topological charge of surfaces are expressed in terms of this solution. We present detailed implementation of these results for surfaces immersed in su(2) and su(3) Lie algebras.Comment: 32 pages, 1 figure; changes: major revision of presentation, clarifications adde

Tzitz\'eica transformation is a dressing action

We classify the simplest rational elements in a twisted loop group, and prove that dressing actions of them on proper indefinite affine spheres give the classical Tzitz\'eica transformation and its dual. We also give the group point of view of the Permutability Theorem, construct complex Tzitz\'eica transformations, and discuss the group structure for these transformations

Shearmeter floats in the area of the WHOI Brazil Basin Tracer Release Experiment : technical and oceanographic data

Six drifting floats designed to measure shear were deployed in the vicinity of the Brazil Basin Tracer Release Experiment. The one-year long time series of oceanographic conditions obtained by the floats are for direct comparison with long-term tracer dispersion. The purpose of the tracer dispersion experiment was to study mixing of Antarctic Bottom Water at approximately 4000 m depth with less dense water above. Two of the floats returned shear records, one from about 1660 m depth and one from about 2800 m depth. Mean shear at 1660 m was 2.2 x 10 -3 s-1 with N = 1.1 cph, about 1.9 times the Garrett-Munk model amount. Mean shear at 2800 m was 1.1 x 10-3 with N = 0.5 cph, about 2.2 times Garrett-Munk. There was no apparent depth structure to the shear recorded by the near-bottom float moving over the mountainous seafloor. The two shear time series and the local tidal velocities were not strongly correlated, but the tide and shear series did have some similarities. Some variability in the 1660-m shear may be due to atmospheric forcing. Three floats deeper than 2800 m returned one-year long trajectories. Two trajectories were persistently eastward.Funding was provided by the National Science Foundation under Grant Nos. OCE-9416014 and OCE-9906685

Clinical and cost-effectiveness of absorbent dressings in the treatment of highly exuding VLUs

l Objective: To estimate the clinical effectiveness and cost effectiveness of using a sodium carboxymethylcellulose dressing (CMC [Aquacel]) and four superabsorbent dressings (DryMax Extra [DM], Flivasorb [F], Kerramax [K] and sachet S [S]) in the treatment of highly exuding chronic venous leg ulcers (VLUs) in the UK, from the perspective of the National Health Service (NHS). l Method:A decision model was constructed depicting the patient pathways and associated management of a cohort of 439 patients with highly exuding chronic VLUs of ≥3 months of age. The model was based on the case records of a cohort of matched patients from The Health Improvement Network (THIN) database (a nationally representative database of patients registered with general practitioners (GPs) in the UK) who were treated with one of the five dressings. The model estimated the costs and outcomes of patient management over 6 months and the relative cost-effectiveness of using each dressing. l Results: Patients’ mean age was 73.1 years, and 46% were female. Between 39% and 56% of VLUs healed by 6 months. CMC-treated wounds that remained unhealed increased in size by 43% over the study period, whereas unhealed wounds treated with the other dressings decreased in size by a mean 34%. Consequently, CMC was excluded from the cost-effectiveness analysis. The 6-monthly NHS cost of managing a VLU with S was £3700 per patient, which was 15–28% lower than the cost of managing patients with the other three superabsorbents. Additonally, use of S improved patients’ health status to a greater extent than the other three superabsorbents, since S-treated patients accrued 0.3–3% more QALYs. Starting treatment with S was the preferred strategy followed by DM, K and F in that order. l Conclusion: Within the limitations of the data set, S affords the NHS a cost-effective treatment for managing highly exuding chronic VLUs of ≥3 months of age, compared with DM, F, K and CMC. l Declaration of interest: This study was funded with an unrestricted research grant from Sorbion GmbH & Co. KG, Senden, Germany, manufacturers of sachet S. However, Sorbion did not have any control of the methodology, conduct, results or conclusion of this study, or editorial involvement in this manuscript. The authors have no other conflicts of interest that are directly relevant to the content of this manuscript, which remains their sole responsibilit

Conformally parametrized surfaces associated with CP^(N-1) sigma models

Two-dimensional conformally parametrized surfaces immersed in the su(N) algebra are investigated. The focus is on surfaces parametrized by solutions of the equations for the CP^(N-1) sigma model. The Lie-point symmetries of the CP^(N-1) model are computed for arbitrary N. The Weierstrass formula for immersion is determined and an explicit formula for a moving frame on a surface is constructed. This allows us to determine the structural equations and geometrical properties of surfaces in R^(N^2-1). The fundamental forms, Gaussian and mean curvatures, Willmore functional and topological charge of surfaces are given explicitly in terms of any holomorphic solution of the CP^2 model. The approach is illustrated through several examples, including surfaces immersed in low-dimensional su(N) algebras.Comment: 32 page

On the shopfloor: exploring the impact of teacher trade unions on school-based industrial relations

Teachers are highly unionised workers and their trade unions exert an important influence on the shaping and implementation of educational policy. Despite this importance there is relatively little analysis of the impact of teacher trade unions in educational management literature. Very little empirical research has sought to establish the impact of teacher unions at school level. In an era of devolved management and quasi-markets this omission is significant. New personnel issues continue to emerge at school level and this may well generate increased trade union activity at the workplace. This article explores the extent to which devolved management is drawing school-based union representation into a more prominent role. It argues that whilst there can be significant differences between individual schools, increased school autonomy is raising the profile of trade union activity in the workplace, and this needs to be better reflected in educational management research

Partnership, ownership and control: the impact of corporate governance on employment relations

Prevailing patterns of dispersed share ownership and rules of corporate governance for UK listed companies appear to constrain the ability of managers to make credible, long-term commitments to employees of the kind needed to foster effective labour-management partnerships. We present case study evidence which suggests that such partnerships can nevertheless emerge where product market conditions and the regulatory environment favour a stakeholder orientation. Proactive and mature partnerships may also be sustained where the board takes a strategic approach to mediating between the claims of different stakeholder groups, institutional investors are prepared to take a long-term view of their holdings, and strong and independent trade unions are in a position to facilitate organisational change