5,713 research outputs found
Noncommutative QED and Anomalous Dipole Moments
We study QED on noncommutative spaces, NCQED. In particular we present the
detailed calculation for the noncommutative electron-photon vertex and show
that the Ward identity is satisfied. We discuss that in the noncommutative case
moving electron will show {\it electric} dipole effects. In addition, we work
out the electric and magnetic dipole moments up to one loop level. For the
magnetic moment we show that noncommutative electron has an intrinsic (spin
independent) magnetic moment.Comment: 27 pages, several .ps and .eps figures, v3:typos in some formula
corrected, version appeared in JHE
Comment on "Constraint Quantization of Open String in Background B field and Noncommutative D-brane"
In the paper "Constraint Quantization of Open String in Background field
and Noncommutative D-brane", it is claimed that the boundary conditions lead to
an infinite set of secondary constraints and Dirac brackets result in a
non-commutative Poisson structure for D-brain. Here we show that contrary to
the arguments in that paper, the set of secondary constraints on the boundary
is finite and the non-commutativity algebra can not be obtained by evaluating
the Dirac brackets.Comment: minor corrections, to appear in Phys.Lett.
Contemporary Issues in Current Account Operations in Pakistani IBs - Sharia Compliant Solution
Contemporary Sharia scholars have three stances about the Current Account Operations in Pakistani Islamic Banks (IBs) i.e., (i) Ijarah based contract (ii) Wadi'ah based contract, and (iii) Qard based contract. This paper is an attempt to delve into the root causes of the differences of scholars and to find the Sharia-compliant solution acceptable for all. Descriptive as well as applied approaches are used in this paper. Clearing of ambiguity on this issue may result in twofold benefits: from the public point of view, it would satisfy practising Muslims which may result in form of huge deposits in this account (ii) from IBs viewpoint the Current Account is a bonus deposit
Labour Market Dynamics in Pakistan: Evidence from the Longitudinal Data
The bulk of research on labour market conditions in Pakistan has concentrated on the economic activity rate, the number of employed persons, or the unemployment rate at a particular point in time. These stock measures of labour market situation are useful from a policy viewpoint as they give a broad indication of the dimension of the problem. For example, the recent labour force surveys show an increase in the level of open unemployment from 5.9 percent in 1997-98 to 7.8 percent in 1999-2000 [Pakistan (2001)]. There is also an emerging consensus that during the 1990s poverty has increased at the national as well as for rural and urban areas of the country [Qureshi and Arif (2001)]. Labour market is considered as the main route for establishing the link between macro policies, the resulting GDP growth and poverty alleviation [Rahman (2002)]. Interim Poverty Reduction Strategy Paper (IPRSP) and other development plans have suggested various targets of employment creation for poverty reduction. The stock measures of labour market conditions, such as unemployment rate, are considered to be inadequate from the viewpoint of developing appropriate policy responses. There is a need to gain further insights by examining the structure of labour market in terms of its dynamic components: these being the turnover of persons into and out of the labour force and turnover into and out of employment and unemployment pools
Dirac Quantization of Open Strings and Noncommutativity in Branes
We apply the Dirac bracket quantization to open strings attached to branes in
the presence of background antisymmetric field and recover an inherent
noncommutativity in the internal coordinates of the brane.Comment: 25 pp, typos corrected, minor change
Achieving hip fracture surgery within 36 hours: an investigation of risk factors to surgical delay and recommendations for practice
BACKGROUND: The UK hip fracture best practice tariff (BPT) aims to deliver hip fracture surgery within 36 h of admission. Ensuring that delays are reserved for conditions which compromise survival, but are responsive to medical optimisation, would help to achieve this target. We aimed to identify medical risk factors of surgical delay, and assess their impact on mortality. MATERIALS AND METHODS: Prospectively collected patient data was obtained from the National Hip Fracture Database (NHFD). Medical determinants of surgical delay were identified and analysed using a multivariate regression analysis. The mortality risk associated with each factor contributing to surgical delay was then calculated. RESULTS: A total 1361 patients underwent hip fracture surgery, of which 537 patients (39.5 %) received surgery within 36 h of admission. Following multivariate analyses, only hyponatraemia was deduced to be a significant risk factor for delay RR = 1.24 (95 % CI 1.06-1.44). However, following a validated propensity score matching process, a Pearson chi-square test failed to demonstrate a statistical difference in mortality incidence between the hypo- and normonatraemic patients [χ (2) (1, N = 512) = 0.10, p = 0.757]. CONCLUSIONS: Hip fracture surgery should not be delayed in the presence of non-severe and isolated hyponatraemia. Instead, surgical delay may only be warranted in the presence of medical conditions which contribute to mortality and are optimisable. LEVEL OF EVIDENCE: III
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