Aesthetic and functional rehabilitation of missing teeth in growing patients with mini-implants: a contemporary approach

Growing patients with missing teeth in aesthetically prominent areas pose a challenge in restoration of the same. Fracture of anterior teeth in these age groups is very common and often requires removal of the affected tooth. After the decision to maintain the space in the dental arch is made, some other factors have to be borne in mind before restoration of the space. Continuing growth of the alveolar bones, questionable cooperation of the patient and aesthetics are deciding factors that may limit the treatment options. The effective use of mini-implants for space preservation, alveolar bone width maintenance and aesthetics represents an elective way of successfully treating such cases. The aim of this article is to describe as well as highlight the advantages and ease of the procedure with the help of two clinical cases

Understanding team resilience in the world's best athletes: a case study of a rugby union World Cup winning team

Objective: Although team resilience research has identified the characteristics of elite sport teams that positively adapt to adversity, further research is required to understand how resilient teams function. The objective of this study, therefore, was to explore the psychosocial processes underpinning team resilience in elite sport. Design: Narrative inquiry was employed to better understand team resilience. Method: The sample consisted of eight members of the 2003 England rugby union World Cup winning team. The autobiographies of these team members were analyzed using three types of narrative analyzes: holistic-content analysis, holistic-form analysis, and categorical-form analysis. Results: Findings revealed five main psychosocial processes underpinning team resilience: transformational leadership, shared team leadership, team learning, social identity, and positive emotions. An examination of narrative structure within the autobiographies revealed a progressive narrative form characterized by a collective positive evaluation of setbacks. Conclusions: This study extends previous team resilience research by going beyond the identification of resilient characteristics to explaining underpinning psychosocial processes. The team resilience processes are discussed in relation to previous research findings and in terms of their implications for practising sport psychologists. It is anticipated that this study will provide practitioners with a framework to develop team resilience at the highest levels of sport

Defining and characterizing team resilience in elite sport

Objectives: The objectives of this study were to develop a definition of team resilience and to identify the resilient characteristics of elite sport teams. Design and Method: Focus groups consisting of a total of 31 participants were conducted with five elite teams from a range of sports. An interpretive thematic analysis using inductive and deductive reasoning was employed to analyze the data. Results and Conclusions: Team resilience was defined as a dynamic, psychosocial process which protects a group of individuals from the potential negative effect of the stressors they collectively encounter. It comprises of processes whereby team members use their individual and combined resources to positively adapt when experiencing adversity. Findings revealed four main resilient characteristics of elite sport teams: group structure, mastery approaches, social capital, and collective efficacy. This study extends resilience research in sport psychology by providing greater conceptual clarity of resilience at a team level. The implications of the findings for those conducting research in this area and for those consulting with elite sport teams are discussed

Closed String Tachyon Condensation at c=1

The c=1 matrix model, with or without a type 0 hat, has an exact quantum solution corresponding to closed string tachyon condensation along a null surface. The condensation occurs, and spacetime dissolves, at a finite retarded time on I^+. The outgoing quantum state of tachyon fluctuations in this time-dependent background is computed using both the collective field and exact fermion pictures. Perturbative particle production induced by the moving tachyon wall is shown to be similar to that induced by a soft moving mirror. Hence, despite the fact that I^+ for the tachyon is geodesicaly incomplete, quantum correlations in the incoming state are unitarily transmitted to the outgoing state in perturbation theory. It is also shown that, non-perturbatively, information can leak across the tachyon wall, and tachyon scattering is not unitary. Exact unitarity remains intact only in the free fermion picture.Comment: Minor corrections; References added; 24 pages, 2 figures, harvma

Glassy Phase Transition and Stability in Black Holes

Black hole thermodynamics, confined to the semi-classical regime, cannot address the thermodynamic stability of a black hole in flat space. Here we show that inclusion of correction beyond the semi-classical approximation makes a black hole thermodynamically stable. This stability is reached through a phase transition. By using Ehrenfest's scheme we further prove that this is a glassy phase transition with a Prigogine-Defay ratio close to 3. This value is well placed within the desired bound (2 to 5) for a glassy phase transition. Thus our analysis indicates a very close connection between the phase transition phenomena of a black hole and glass forming systems. Finally, we discuss the robustness of our results by considering different normalisations for the correction term.Comment: v3, minor changes over v2, references added, LaTeX-2e, 18 pages, 3 ps figures, to appear in Eour. Phys. Jour.

Off-Shell Interactions for Closed-String Tachyons

Off-shell interactions for localized closed-string tachyons in C/Z_N superstring backgrounds are analyzed and a conjecture for the effective height of the tachyon potential is elaborated. At large N, some of the relevant tachyons are nearly massless and their interactions can be deduced from the S-matrix. The cubic interactions between these tachyons and the massless fields are computed in a closed form using orbifold CFT techniques. The cubic interaction between nearly-massless tachyons with different charges is shown to vanish and thus condensation of one tachyon does not source the others. It is shown that to leading order in N, the quartic contact interaction vanishes and the massless exchanges completely account for the four point scattering amplitude. This indicates that it is necessary to go beyond quartic interactions or to include other fields to test the conjecture for the height of the tachyon potential.Comment: 37 pages, 3 figures, LaTeX, JHEP class. Typos corrected, references added, published versio

A texture of neutrino mass matrix in view of recent neutrino experimental results

In view of recent neutrino experimental results such as SNO, Super-Kamiokande (SK), CHOOZ and neutrinoless double beta decay $(\beta\beta_{0\nu})$, we consider a texture of neutrino mass matrix which contains three parameters in order to explain those neutrino experimental results. We have first fitted parameters in a model independent way with solar and atmospheric neutrino mass squared differences and solar neutrino mixing angle which satisfy LMA solution. The maximal value of atmospheric neutrino mixing angle comes out naturally in the present texture. Most interestingly, fitted parameters of the neutrino mass matrix considered here also marginally satisfy recent limit on effective Majorana neutrino mass obtained from neutrinoless double beta decay experiment. We further demonstrate an explicit model which gives rise to the texture investigated by considering an $SU(2)_L\times U(1)_Y$ gauge group with two extra real scalar singlets and discrete $Z_2\times Z_3$ symmetry. Majorana neutrino masses are generated through higher dimensional operators at the scale $M$. We have estimated the scales at which singlets get VEV's and M by comparing with the best fitted results obtained in the present work.Comment: Journal Ref.: Phys. Rev. D66, 053004 (2002

Can R-parity violation explain the LSND data as well?

The recent Super-Kamiokande data now admit only one type of mass hierarchy in a framework with three active and one sterile neutrinos. We show that neutrino masses and mixings generated by R-parity-violating couplings, with values within their experimental upper limits, are capable of reproducing this hierarchy, explaining all neutrino data particularly after including the LSND results.Comment: 7 pages, Latex, 3 PS figures; in v2 a few clarifying remarks included and two references added (to appear in Physical Review D

Gravitational Lensing by Black Holes

We review the theoretical aspects of gravitational lensing by black holes, and discuss the perspectives for realistic observations. We will first treat lensing by spherically symmetric black holes, in which the formation of infinite sequences of higher order images emerges in the clearest way. We will then consider the effects of the spin of the black hole, with the formation of giant higher order caustics and multiple images. Finally, we will consider the perspectives for observations of black hole lensing, from the detection of secondary images of stellar sources and spots on the accretion disk to the interpretation of iron K-lines and direct imaging of the shadow of the black hole.Comment: Invited article for the GRG special issue on lensing (P. Jetzer, Y. Mellier and V. Perlick Eds.). 31 pages, 12 figure

Search for a W' boson decaying to a bottom quark and a top quark in pp collisions at sqrt(s) = 7 TeV

Results are presented from a search for a W' boson using a dataset corresponding to 5.0 inverse femtobarns of integrated luminosity collected during 2011 by the CMS experiment at the LHC in pp collisions at sqrt(s)=7 TeV. The W' boson is modeled as a heavy W boson, but different scenarios for the couplings to fermions are considered, involving both left-handed and right-handed chiral projections of the fermions, as well as an arbitrary mixture of the two. The search is performed in the decay channel W' to t b, leading to a final state signature with a single lepton (e, mu), missing transverse energy, and jets, at least one of which is tagged as a b-jet. A W' boson that couples to fermions with the same coupling constant as the W, but to the right-handed rather than left-handed chiral projections, is excluded for masses below 1.85 TeV at the 95% confidence level. For the first time using LHC data, constraints on the W' gauge coupling for a set of left- and right-handed coupling combinations have been placed. These results represent a significant improvement over previously published limits.Comment: Submitted to Physics Letters B. Replaced with version publishe