Three Dimensional Integrable Mappings

We derive three-dimensional integrable mappings which have two invariants.Comment: 6 pages, part of this paper is taken from the author's PhD thesis, not submitted for publicatio

Singularity confinement and algebraic integrability

Two important notions of integrability for discrete mappings are algebraic integrability and singularity confinement, have been used for discrete mappings. Algebraic integrability is related to the existence of sufficiently many conserved quantities whereas singularity confinement is associated with the local analysis of singularities. In this paper, the relationship between these two notions is explored for birational autonomous mappings. Two types of results are obtained: first, algebraically integrable mappings are shown to have the singularity confinement property. Second, a proof of the non-existence of algebraic conserved quantities of discrete systems based on the lack of confinement property is given.Comment: 18 pages, no figur

An Attempt to Measure the Traffic Impact of Airline Alliances

This paper analyzes the effects of airline alliances on the allied partners output by comparing the traffic change observed between the pre- and the post-alliance period. First, a simple methodology based on traffic passenger modelling is developed, and then an empirical analysis is conducted using time series from four global strategic alliances (Wings, Star Alliance, oneworld and SkyTeam) and 124 alliance routes. The analysis concludes that, all other things being equal, strategic alliances do lead to a 9.4%, on average, improvement in passenger volume

Characterization of Acetyl-CoA: Lyso-PAF Acetyltransferase of Human Mesangial Cells

Platelet activating factor (PAF) is a potent inflammatory mediator produced by various renal cells and it is implicated in renal pathology. The aim of this study is the characterization of remodeling lyso-PAF acetyltransferase, which is activated under inflammatory conditions, in human mesangial cell. Total membranes of mesangial cells were isolated and enzymatic activity and kinetic parameters were determined by trichloroacetic acid precipitation method. The effect of BSA, divalent cations, EDTA, and various chemicals on the activity of lyso-PAF acetyltransferase was also studied. Various detergents were also tested for the solubilization of the enzyme and only glycerol did not affect its activity. Partial purification of solubilized enzyme preparations of human kidney tissue and mesangial cells was performed on anion exchange column chromatography and native-PAGE electrophoresis and two active fractions were detected

How Do Airlines Perceive That Strategic Alliances Affect Their Individual Branding?

Much research has been carried out to evaluate the impact of strategic alliance membership on the performance of airlines. However it would be of interest to identify how airlines perceive this impact in terms of branding by each of the three global alliance groupings. It is the purpose of this paper to gather the opinion of airlines, belonging to the three strategic alliance groups, on the impact that the strategic alliance brands have had on their individual brands and how do they perceive that this impact will change in the future. To achieve this, a comprehensive survey of the alliance management and marketing departments of airlines participating in the three global strategic alliances was required. The results from this survey give an indication whether the strategic airline alliances, which are often referred to as marketing agreements, enhance, damage or have no impact on the individual airline brands

Segmental sandwich osteotomy of the posterior mandible in pre-implant surgery : a systematic review

The rehabilitation of the atrophic posterior mandible with dental implants often requires bone augmentation procedures. The aim of the present study is the systematic review of the literature concerning the success rate of Segmental Sandwich Osteotomy (SSO) of the posterior mandible in pre-implant surgery. Systematic review of all clinical cases and clinical studies of SSO of the posterior mandible in pre-implant surgery with a minimum follow-up of 6 months after implant loading was performed, based on specific inclusion and exclusion criteria. The search strategy involved searching the electronic databases of MEDLINE, EMBASE, COCHRANE LIBRARY, Clinical Trials (www.clinicaltrials.gov) and National Research Register (www.controlled-trials.com), supplemented by a manual search, in August 2015. In every study, the intervention characteristics and the outcome were recorded. Out of the 756 initial results, only 17 articles fulfilled the predetermined inclusion and exclusion criteria. They consisted of 9 retrospective case reports or series and 8 prospective randomized clinical trials. Overall, the studies included 174 patients. In these patients, 214 SSO augmentation procedures were performed in the posterior mandible and 444 implants were placed. The follow-up period after implant loading ranged between 8 months and 5.5 years. The success rate of SSO ranged between 90% and 100%. The implant survival during the follow-up period ranged between 90.9% and 100%. Segmental Sandwich Osteotomy should be considered as a well documented technique for the rehabilitation of the atrophic posterior mandible, with long-term postsurgical follow-up. The success rates are very high, as well as the survival of the dental implants placed in the augmented area