Admission control for Web server systems - design and experimental evaluation

evaluatio

Introduction of total knee arthroplasty in Lithuania: Results from the first 10 years

Background and purpose We have previously reported that the first 10 years of hip arthroplasty in Lithuania resulted in a higher cumulative revision rate than that observed in Sweden. We thus compared the corresponding results after introduaction of total knee replacement in Lithuania

State of the science on controversial topics: missing maxillary lateral incisors--a report of the Angle Society of Europe 2012 meeting.

BACKGROUND: The optimal long-term management of the congenitally missing maxillary lateral incisor continues to cause controversy within the specialty. The Angle Society of Europe meeting 2012 dedicated a day to address some of the current controversies relating to the management of these missing lateral incisors. FINDINGS: The format of the day consisted of morning presentations and afternoon breakout sessions to discuss a variety of questions related to the management of missing lateral incisors. CONCLUSIONS: The consensus viewpoint from this day was that the care of patients with congenitally missing lateral incisors is best achieved through a multi-disciplinary approach. The current evidence base is weak, and further well-designed, prospective trials are needed

Free and smooth boundaries in 2-D finite-difference schemes for transient elastic waves

A method is proposed for accurately describing arbitrary-shaped free boundaries in single-grid finite-difference schemes for elastodynamics, in a time-domain velocity-stress framework. The basic idea is as follows: fictitious values of the solution are built in vacuum, and injected into the numerical integration scheme near boundaries. The most original feature of this method is the way in which these fictitious values are calculated. They are based on boundary conditions and compatibility conditions satisfied by the successive spatial derivatives of the solution, up to a given order that depends on the spatial accuracy of the integration scheme adopted. Since the work is mostly done during the preprocessing step, the extra computational cost is negligible. Stress-free conditions can be designed at any arbitrary order without any numerical instability, as numerically checked. Using 10 grid nodes per minimal S-wavelength with a propagation distance of 50 wavelengths yields highly accurate results. With 5 grid nodes per minimal S-wavelength, the solution is less accurate but still acceptable. A subcell resolution of the boundary inside the Cartesian meshing is obtained, and the spurious diffractions induced by staircase descriptions of boundaries are avoided. Contrary to what occurs with the vacuum method, the quality of the numerical solution obtained with this method is almost independent of the angle between the free boundary and the Cartesian meshing.Comment: accepted and to be published in Geophys. J. In

Different incidences of knee arthroplasty in the Nordic countries.

To access publisher's full text version of this article, please click on the hyperlink in Additional Links field or click on the hyperlink at the top of the page marked FilesBackground and purpose - The annual number of total knee arthroplasties (TKAs) has increased worldwide in recent years. To make projections regarding future needs for primaries and revisions, additional knowledge is important. We analyzed and compared the incidences among 4 Nordic countries Patients and methods - Using Nordic Arthroplasty Register Association (NARA) data from 4 countries, we analyzed differences between age and sex groups. We included patients over 30 years of age who were operated with TKA or unicompartmental knee arthroplasty (UKA) during the period 1997-2012. The negative binomial regression model was used to analyze changes in general trends and in sex and age groups. Results - The average annual increase in the incidence of TKA was statistically significant in all countries. The incidence of TKA was higher in women than in men in all 4 countries. It was highest in Finland in patients aged 65 years or more. At the end of the study period in 2012, Finland's total incidence was double that of Norway, 1.3 times that of Sweden and 1.4 times that of Denmark. The incidence was lowest in the youngest age groups (< 65 years) in all 4 countries. The proportional increase in incidence was highest in patients who were younger than 65 years. Interpretation - The incidence of knee arthroplasty steadily increased in the 4 countries over the study period. The differences between the countries were considerable, with the highest incidence in Finland. Patients aged 65 years or more contributed to most of the total incidence of knee arthroplasty.NordForsk gran

High tibial osteotomy in Sweden, 1998–2007: A population-based study of the use and rate of revision to knee arthroplasty

To access publisher's full text version of this article. Please click on the hyperlink in Additional Links field.Most studies on high tibial osteotomies (HTOs) have been hospital-based and have included a limited number of patients. We evaluated the use and outcome-expressed as rate of revision to knee arthroplasty-of HTO performed in Sweden with 9 million inhabitants, 1998-2007. 3, 161 HTO procedures on patients 30 years or older (69% men) who were operated on for knee osteoarthritis in Sweden, 1998-2007, were identified through the inpatient and outpatient care registers of the Swedish National Board of Health and Welfare. Pertinent data were verified through surgical records. Conversions of HTO to knee arthroplasty before 2010 were identified through the Swedish Knee Arthroplasty Register (SKAR). The 10-year survival was determined using revision to an arthroplasty as the endpoint. The number of HTOs decreased by one third between 1998 and 2007, from 388 operations a year to 257 a year. Most of the HTOs were performed with open wedge osteotomy using external fixation. The cumulative revision rate at 10 years was 30% (95% CI: 28-32). The risk of revision increased with increasing age and was higher in women than in men (RR = 1.3, CI: 1.1-1.5). If being without an artificial joint implant is considered to be beneficial, then HTO is an excellent alternative to knee arthroplasty in younger and/or physically active patients suffering from knee osteoarthritis.Swedish Research Council Swedish Rheumatism Association King Gustaf V 80-year Birthday Fund Faculty of Medicine, Lund University Region Skan

Intracapsular pressure and interleukin-1β cytokine in hips with acetabular dysplasia

Background and purpose Several studies have demonstrated an increased intracapsular pressure in several hip disorders such as septic arthritis, synovitis, and trauma. We therefore measured the intracapsular pressure in different positions in early dysplasic hips and its relation to the concentration of interleukin-1β (IL-1β), the volume of joint fluid, and the clinical and radiographic findings before a periacetabular osteotomy

Statistical analysis of arthroplasty data: II. Guidelines

It is envisaged that guidelines for statistical analysis and presentation of results will improve the quality and value of research. The Nordic Arthroplasty Register Association (NARA) has therefore developed guidelines for the statistical analysis of arthroplasty register data. The guidelines are divided into two parts, one with an introduction and a discussion of the background to the guidelines (Ranstam et al. 2011a, see pages x-y in this issue), and this one with a more technical statistical discussion on how specific problems can be handled. This second part contains (1) recommendations for the interpretation of methods used to calculate survival, (2) recommendations on howto deal with bilateral observations, and (3) a discussion of problems and pitfalls associated with analysis of factors that influence survival or comparisons between outcomes extracted from different hospitals

Compensating for source directivity in immersive wave experimentation

ISSN:0001-4966ISSN:1520-852

In vitro influence of stem surface finish and mantle conformity on pressure generation in cemented hip arthroplasty

Background and purpose Under physiological loads, debonded cemented femoral stems have been shown to move within their cement mantle and generate a fluid pump that may facilitate peri-prosthetic osteolysis by pressurizing fluid and circulating wear debris. The long-term physiological loading of rough and polished tapered stems in vitro has shown differences in performance, with greater interface pressures generated by the rough stems. In this study we investigated the individual effects of stem surface finish, degree of mantle wear, and mode of loading on the stem pump mechanism