29,456 research outputs found
M-Theory and Hypercharge
We discuss the possibility that the electro-weak and strong interactions
arise as the low energy effective description of branes in M-theory. As a step
towards constructing such a model we show how one can naturally obtain
SU(N_1)\times SU(N_2)\times U(1) gauge theories from branes, including matter
in the bi-fundamental representation of SU(N_1)\times SU(N_2) which are
fractionally charged under U(1).Comment: 29 pages Phyzzx. Two figure
N=2 Superfields and the M-Fivebrane
In this paper we provide a manifestly N=2 supersymmetric formulation of the
M-fivebrane in the presence of threebrane solitons. The superspace form of
four-dimensional effective equations for the threebranes are readily obtained
and yield the complete Seiberg-Witten equations of motion for N=2
super-Yang-Mills. A particularly simple derivation is given by introducing an
N=2 superfield generalisation of the Seiberg-Witten differential.Comment: 14 pages phyzzx. Added paragraph on the existence of a
six-dimensional action. To appear in Phys. Lett.
GPs' views on new national smoking cessation guidelines
Objectives: To assess GPs? views on recently published national smoking cessation guidelines that form the foundation of the government?s smoking cessation strategy.Design: Postal survey of a random sample of GPs. GPs were asked to judge the appropriateness, effectiveness and practicability of key recommendations for primary care in recent national smoking cessation guidelines.Setting: General practice, England and Wales.Subjects: 236 GPs, effective response rate: 62%.Results: Only 16% of GPs accepted that all the recommendations in the guidelines were appropriate; 43% accepted that it was appropriate to check the smoking status of known smokers when they visit the surgery and only 30% thought it was practicable to advise smokers to stop at every opportunity. However, 77% of GPs thought that they should provide assistance for smokers wanting to stop; 74% believed that they should refer smokers to specialist services if appropriate and a similar proportion (77%) believed that it was appropriate to recommend nicotine replacement. Conclusions: Recommendations that involved the GP being proactive in monitoring smoking status and advising smokers to stop were not widely supported. There was greater acceptance that GPs should assist smokers wanting to stop, either by recommending NRT or providing counselling or referral. It appears that GPs do not widely support those recommendations that would produce the greatest public health gains
Holder exponent spectra for human gait
The stride interval time series in normal human gait is not strictly
constant, but fluctuates from step to step in a complex manner. More precisely,
it has been shown that the control process for human gait is a fractal random
phenomenon, that is, one with a long-term memory. Herein we study the Holder
exponent spectra for the slow, normal and fast gaits of 10 young healthy men in
both free and metronomically triggered conditions and establish that the stride
interval time series is more complex than a monofractal phenomenon. A slightly
multifractal and non-stationary time series under the three different gait
conditions emerges.Comment: 23 pages, 12 figures, 9 Table
Predictive control for energy management in all/more electric vehicles with multiple energy storage units
The paper describes the application of Model Predictive Control (MPC) methodologies for application to electric and hybrid-electric vehicle drive-train formats incorporating multiple energy/power sources. Particular emphasis is given to the co-ordinated management of energy flow from the multiple sources to address issues of extended vehicle range and battery life-time for all-electric drive-trains, and emissions reduction and drive-train torsional oscillations, for hybrid-electric counterparts, whilst accommodating operational constraints and, ultimately, generic non-standard driving cycles
Generalised BPS conditions
We write down two E11 invariant conditions which at low levels reproduce the
known half BPS conditions for type II theories. These new conditions contain,
in addition to the familiar central charges, an infinite number of further
charges which are required in an underlying theory of strings and branes. We
comment on the application of this work to higher derivative string
corrections
E11 and Spheric Vacuum Solutions of Eleven- and Ten dimensional Supergravity Theories
In view of the newly conjectured Kac-Moody symmetries of supergravity
theories placed in eleven and ten dimensions, the relation between these
symmetry groups and possible compactifications are examined. In particular, we
identify the relevant group cosets that parametrise the vacuum solutions of AdS
x S type.Comment: discussion improve
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