1,334 research outputs found

    Minimum intervention children's dentistry - the starting point for a lifetime of oral health

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    Child-friendly minimum intervention dentistry (MID) dominates modern thinking and practice around delivery of oral care for children. It is an enormous challenge for our profession to move away from the narrow focus of a mechanistic, cavity-orientated surgical approach for managing dental caries to one which embraces new strategies for caries prevention and management, delivered in the context of a partnership with children, families and other adults involved in the child's life environment. It is also time for a shift in the orientation of dentistry towards 'patient self-care' becoming a core goal of dental care, where dentists help their patients assume responsibility for achieving and maintaining their own oral health, and that of their children. Holistic care, which improves oral health and maximises ability to maintain oral health, should be regarded with the same importance and rewarded with a similar level of remuneration as 'traditional operative dentistry'. This paper gives an overview of a model of care involving the principles of this new approach, and the application of MID in clinical practice for primary teeth

    Zero Modes of Rotationally Symmetric Generalized Vortices and Vortex Scattering

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    Zero modes of rotationally symmetric vortices in a hierarchy of generalized Abelian Higgs models are studied. Under the finite-energy and the smoothness condition, it is shown, that in all models, nn self-dual vortices superimposed at the origin have 2n2n modes. The relevance of these modes for vortex scattering is discussed, first in the context of the slow-motion approximation. Then a corresponding Cauchy problem for an all head-on collision of nn vortices is formulated. It is shown that the solution of this Cauchy problem has a πn\frac{\pi}{n} symmetry.Comment: 12 pages. late

    Statistical Mechanics of Charged Particles in Einstein-Maxwell-Scalar Theory

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    We consider an NN-body system of charged particle coupled to gravitational, electromagnetic, and scalar fields. The metric on moduli space for the system can be considered if a relation among the charges and mass is satisfied, which includes the BPS relation for monopoles and the extreme condition for charged black holes. Using the metric on moduli space in the long distance approximation, we study the statistical mechanics of the charged particles at low velocities. The partition function is evaluated as the leading order of the large dd expansion, where dd is the spatial dimension of the system and will be substituted finally as d=3d=3.Comment: 11 pages, RevTeX3.

    New Integrable Sectors in Skyrme and 4-dimensional CP^n Model

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    The application of a weak integrability concept to the Skyrme and CPnCP^n models in 4 dimensions is investigated. A new integrable subsystem of the Skyrme model, allowing also for non-holomorphic solutions, is derived. This procedure can be applied to the massive Skyrme model, as well. Moreover, an example of a family of chiral Lagrangians providing exact, finite energy Skyrme-like solitons with arbitrary value of the topological charge, is given. In the case of CPnCP^n models a tower of integrable subsystems is obtained. In particular, in (2+1) dimensions a one-to-one correspondence between the standard integrable submodel and the BPS sector is proved. Additionally, it is shown that weak integrable submodels allow also for non-BPS solutions. Geometric as well as algebraic interpretations of the integrability conditions are also given.Comment: 23 page

    Massless monopoles and the moduli space approximation

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    We investigate the applicability of the moduli space approximation in theories with unbroken non-Abelian gauge symmetries. Such theories have massless magnetic monopoles that are manifested at the classical level as clouds of non-Abelian field surrounding one or more massive monopoles. Using an SO(5) example with one massive and one massless monopole, we compare the predictions of the moduli space approximation with the results of a numerical solution of the full field equations. We find that the two diverge when the cloud velocity becomes of order unity. After this time the cloud profile approximates a spherical wavefront moving at the speed of light. In the region well behind this wavefront the moduli space approximation continues to give a good approximation to the fields. We therefore expect it to provide a good description of the motion of the massive monopoles and of the transfer of energy between the massive and massless monopoles.Comment: 18 pages, 5 figure

    Electrically Charged Sphalerons

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    We investigate the possibility that the Higgs sector of the Weinberg-Salam model admits the existence of electrically charged, sphaleron states. Evidence is provided through an asymptotic and numerical perturbative analysis about the uncharged sphaleron. By introducing a toy model in two dimensions we demonstrate that such electrically charged, unstable states can exist. Crucially, they can have a comparable mass to their uncharged counterparts and so may also play a role in electroweak baryogenesis, by opening up new channels for baryon number violating processes.Comment: 12 pages, 4 Postscript figure

    Dynamics of BPS Dyons: Effective Field Theory Approach

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    Based on a detailed analysis of nonlinear field equations of the SU(2) Yang-Mills-Higgs system, we obtain the effective field theory describing low-energy interaction of BPS dyons and massless particles (i.e., photons and Higgs particles). Our effective theory manifests electromagnetic duality and spontaneously broken scale symmetry, and reproduces the multimonopole moduli space dynamics of Manton in a suitable limit. Also given is a generalization of our approach to the case of BPS dyons in a gauge theory with an arbitrary gauge group that is maximally broken.Comment: 48 pages, uses revte
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