Breakout Local Search for the Travelling Salesman Problem

The travelling salesman problem (TSP), a famous NP-hard combinatorial optimisation problem (COP), consists of finding a minimum length tour that visits n cities exactly once and comes back to the starting city. This paper presents a resolution of the TSP using the breakout local search metaheuristic algorithm (BLS), which is based on the iterated local search (ILS) framework and improves it by introducing some fundamental features of several well-established metaheuristics such as tabu search (TS) and variable neighbourhood search (VNS). BLS moves from a local optimum of a neighbourhood to another by applying perturbation jumps whose type and number are determined adaptively. It has already been applied to many COP and gives good results. This innovative hybridisation resolved well 41 instances from the commonly used benchmark library TSPLIB. The high quality of experimental results shows the competitiveness of the proposed algorithm compared to other algorithms based on local search

A Memetic Algorithm Based on Breakout Local Search for the Generalized Traveling Salesman Problem

The Traveling Salesman Problem (TSP) is one of the most popular Combinatorial Optimization Problem. It is well solicited for the large variety of applications that it can solve, but also for its difficulty to find optimal solutions. One of the variants of the TSP is the Generalized TSP (GTSP), where the TSP is considered as a special case which makes the GTSP harder to solve. We propose in this paper a new memetic algorithm based on the well-known Breakout Local Search (BLS) metaheuristic to provide good solutions for GTSP instances. Our approach is competitive compared to other recent memetic algorithms proposed for the GTSP and gives at the same time some improvements to BLS to reduce its runtime

Autologous Myoblast Transplantation for Oculopharyngeal Muscular Dystrophy: a Phase I/Iia Clinical Study

International audienc

Autologous Myoblast Transplantation for Oculopharyngeal Muscular Dystrophy: a Phase I/Iia Clinical Study

Oculopharyngeal muscular dystrophy (OPMD) is a late-onset autosomal dominant genetic disease mainly characterized by ptosis and dysphagia. We conducted a phase I/IIa clinical study (ClinicalTrials.gov NCT00773227) using autologous myoblast transplantation following myotomy in adult OPMD patients. This study included 12 patients with clinical diagnosis of OPMD, indication for cricopharyngeal myotomy, and confirmed genetic diagnosis. The feasibility and safety end points of both autologous myoblast transplantation and the surgical procedure were assessed by videoendoscopy in addition to physical examinations. Potential therapeutic benefit was also assessed through videoendoscopy and videofluoroscopy of swallowing, quality of life score, dysphagia grade, and a drink test. Patients were injected with a median of 178 million myoblasts following myotomy. Short and long-term (2 years) safety and tolerability were observed in all the patients, with no adverse effects. There was an improvement in the quality of life score for all 12 patients, and no functional degradation in swallowing was observed for 10 patients. A cell dose-dependant improvement in swallowing was even observed in this study. This trial supports the hypothesis that a local injection of autologous myoblasts in the pharyngeal muscles is a safe and efficient procedure for OPMD patients