Computer Algebra meets Finite Elements: an Efficient Implementation for Maxwell's Equations

We consider the numerical discretization of the time-domain Maxwell's equations with an energy-conserving discontinuous Galerkin finite element formulation. This particular formulation allows for higher order approximations of the electric and magnetic field. Special emphasis is placed on an efficient implementation which is achieved by taking advantage of recurrence properties and the tensor-product structure of the chosen shape functions. These recurrences have been derived symbolically with computer algebra methods reminiscent of the holonomic systems approach.Comment: 16 pages, 1 figure, 1 table; Springer Wien, ISBN 978-3-7091-0793-

An Operations management approach for radiology services

This paper focus on the application of Operations Management techniques in the context of radiological and diagnostic imaging services provision. More specifically, the outpatient appointment scheduling problem for MRI diagnostic imaging services in a radiology clinics is approached and solved taking into account set-up time minimization. This is pursued trough the design of an innovative system for the on-line assignment of appointments for specific diagnostic imaging scans. An appointment rule, a patient classification and an heuristic procedure for the booking process are defined in order to better manage uncertainty and improve system performance. The proposed approach was validated on the case of a diagnostic centre of Alliance Medical, a primary multinational company in the field of diagnostic imaging services

Treatment of intermetatarsal Morton's neuroma with alcohol injection under US guide: 10-month follow-up

Mortons neuroma (MN) is a frequent cause of metatarsalgia. The aim of our study was to evaluate the efficacy of neuroma alcohol-sclerosing therapy (NAST) under US guide in MN after a 10-month follow-up. Forty intermetatarsal neuromas underwent alcohol-sclerosing therapy after sonographic evaluation of their dimensions and echotexture. After subcutaneous anesthesia, a sclerosing solution composed of anesthetic (carbocaine-adrenaline 70%) and ethylic alcohol (30%) was injected inside the mass under US guidance. The procedure was repeated at intervals of 15 days until the resolution of the symptoms. A total or partial symptomatic relief was obtained in 36 cases (90%). No procedure-related complications were observed. Transitory plantar pain, due to the flogistic reaction induced by the sclerosing solution, occurred in 6 cases (15%). The 10-month follow-up revealed a 20-30% mass volume reduction and an adiposus-like change in echotexture. In the 4 cases (10%) of therapeutic failure, the preliminary sonography demonstrated a hypoechoic echotexture with a strong US beam attenuation corresponding to a highly fibrous neuroma after surgical resection. The NAST is a feasible and cost-efficient procedure with high rates of therapeutic success

Etude des contraintes dynamiques et l'interaction homme-cadre aérien chez les artistes du cirque.

Le but de cette étude et d'analyser le comportement dynamique d'un cadre aérien sujet a des sollicitations induites par les voltigeuses lors d'un numéro. L'étude est divisée en deux parties et pour chaque partie une étude expérimentales et numérique est entreprise. Le calcul par éléments finis permet, entre autres, la simulation très précise et réaliste du comportement mécanique (déplacements, contraintes, déformations...) de structures complexes sans avoir à réaliser de prototype physique. Ainsi, en phase de conception, on peut tirer très avantageusement profit du calcul par éléments finis pour dimensionner, valider ou optimiser des composants ou assemblages complets

A First Comparison Between LIGO and Virgo Inspiral Search Pipelines

This article reports on a project that is the first step the LIGO Scientific Collaboration and the Virgo Collaboration have taken to prepare for the mutual search for inspiral signals. The project involved comparing the analysis pipelines of the two collaborations on data sets prepared by both sides, containing simulated noise and injected events. The ability of the pipelines to detect the injected events was checked, and a first comparison of how the parameters of the events were recovered has been completed.Comment: GWDAW-9 proceeding

Pedobarographic analysis and quality of life after lisfranc fracture dislocation

Background: Few studies on tarsometatarsal fracture dislocations report on plantar pressure analysis and quality of life. The primary aim of this study was to determine the added value of plantar pressure analysis. The secondary aim was to determine quality of life and functional outcome. Materials and Methods: With a median followup of 76 months, 26 patients with an isolated Lisfranc injury participated. The Short Form 36 (SF-36) was used to determine the health related

Combined rotation scarf and Akin osteotomies for hallux valgus: a patient focussed 9 year follow up of 50 patients

<p>Abstract</p> <p>Background</p> <p>The Cochrane review of hallux valgus surgery has disputed the scientific validity of hallux valgus research. Scoring systems and surrogate measures such as x-ray angles are commonly reported at just one year post operatively but these are of dubious relevance to the patient. In this study we extended the follow up to a minimum of 8 years and sought to address patient specific concerns with hallux valgus surgery. The long term follow up also allowed a comprehensive review of the complications associated with the combined rotation scarf and Akin osteotomies.</p> <p>Methods</p> <p>Between 1996 and 1999, 101 patients underwent rotation scarf and Akin osteotomies for the treatment of hallux valgus. All patients were contacted and asked to participate in this study. 50 female participants were available allowing review of 73 procedures. The average follow up was over 9 years and the average age at the time of surgery was 57. The participants were physically examined and interviewed.</p> <p>Results</p> <p>Post-operatively, in 86% of the participants there were no footwear restrictions. Stiffness of the first metatarsophalangeal joint was reported in 8% (6 feet); 10% were unhappy with the cosmetic appearance of their feet, 3 feet had hallux varus, and 2 feet had recurrent hallux valgus. There were no foot-related activity restrictions in 92% of the group. Metatarsalgia occurred in 4% (3 feet). 96% were better than before surgery and 88% were completely satisfied with their post-operative result. Hallux varus was the greatest single cause of dissatisfaction. The most common adverse event in the study was internal fixation irritation. Hallux valgus surgery is not without risk and these findings could be useful in the informed consent process.</p> <p>Conclusions</p> <p>When combined the rotation scarf and Akin osteotomies are an effective treatment for hallux valgus that achieves good long-term correction with a low incidence of recurrence, footwear restriction or metatarsalgia. The nature of the osteotomies allows early return to normal shoes and activity without the need for postoperative immobilisation in a plaster cast.</p

Biophysical stimulation of bone and cartilage : state of the art and future perspectives

Introduction: Biophysical stimulation is a non-invasive therapy used in orthopaedic practice to increase and enhance reparative and anabolic activities of tissue. Methods: A sistematic web-based search for papers was conducted using the following titles: (1) pulsed electromagnetic field (PEMF), capacitively coupled electrical field (CCEF), low intensity pulsed ultrasound system (LIPUS) and biophysical stimulation; (2) bone cells, bone tissue, fracture, non-union, prosthesis and vertebral fracture; and (3) chondrocyte, synoviocytes, joint chondroprotection, arthroscopy and knee arthroplasty. Results: Pre-clinical studies have shown that the site of interaction of biophysical stimuli is the cell membrane. Its effect on bone tissue is to increase proliferation, synthesis and release of growth factors. On articular cells, it creates a strong A2A and A3 adenosine-agonist effect inducing an anti-inflammatory and chondroprotective result. In treated animals, it has been shown that the mineralisation rate of newly formed bone is almost doubled, the progression of the osteoarthritic cartilage degeneration is inhibited and quality of cartilage is preserved. Biophysical stimulation has been used in the clinical setting to promote the healing of fractures and non-unions. It has been successfully used on joint pathologies for its beneficial effect on improving function in early OA and after knee surgery to limit the inflammation of periarticular tissues. Discussion: The pooled result of the studies in this review revealed the efficacy of biophysical stimulation for bone healing and joint chondroprotection based on proven methodological quality. Conclusion: The orthopaedic community has played a central role in the development and understanding of the importance of the physical stimuli. Biophysical stimulation requires care and precision in use if it is to ensure the success expected of it by physicians and patients