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Until recent years there has been no evidence from randomized controlled trials (RCTs) on the efficacy of deep brain stimulation (DBS) for Parkinson's disease (PD). This review and meta-analysis of RCTs describes the efficacy of DBS in improving motor signs, functionality and quality of life of PD patients. Several electronic databases were consulted up to(More)
User-level threads have been used to implement migratable MPI processes. This is a better strategy to implement load balancing mechanisms. That is because, in general, these threads are faster to create, manage and migrate than heavy processes and kernel threads. However, they present some issues concerning private data because they break the private(More)
We revisit and use the dependence transformation method to generate parallel algorithms suitable for cluster and grid computing. We illustrate this method in two applications: to obtain a systolic matrix product algorithm, and to compute the alignment score of two strings. The product of two n × n matrices is viewed as multiplying two p × p matrices whose(More)
BACKGROUND Reactive oxygen species may mediate tissue injury in inflammatory bowel disease. Aminosalicylates have antioxidant activity and the antioxidants, superoxide dismutase and allopurinol, are of reported benefit in inflammatory bowel disease. AIM To develop a convenient technique for testing the antioxidant potential of standard and novel(More)
We reviewed the medical records of all patients with confirmed mitochondrial diseases treated with any or all of thiamin, riboflavin, coenzyme Q, vitamin C (approximately 10 mg/kg per day) and a high-fat diet (50-60% of caloric intake) between 1997 and 2003. There were 15 patients (9 male): 10 had enzymatic deficiency and 10 had a molecular diagnosis. Age(More)
We describe the computational characteristics of the Kirchhoff prestack seismic migration currently used in daily production runs at Petrobras and its port to novel architectures. Fully developed in house, this portable and fault tolerant application has high sequential and parallel efficiency, with parallel scalability tested up to 8192 processors on the(More)
We discuss the performance of Petrobras production Kirchhoff prestack seismic migration on a cluster of 64 GPUs and 256 CPU cores. Porting and optimization of the application hot spot (98.2% of a single CPU core execution time) to a single GPU reduces total execution time by a factor of 36 on a control run. We then argue against the usual practice of(More)
Among the many reasons for load imbalance in weather forecasting models, the dynamic imbalance caused by localized variations on the state of the atmosphere is the hardest one to handle. As an example, active thunderstorms may substantially increase load at a certain time step with respect to previous time steps in an unpredictable manner – after(More)
This work shows how a Hybrid MPI/OpenMP implementation can improve the performance of the Ocean-Land-Atmosphere Model (OLAM) on a multi-core cluster environment, which is a typical HPC many small files workload application. Previous experiments have shown that the scalability of this application on clusters is limited by the performance of the output(More)