Analyzing the Sensitivity to Faults of Synchronization Primitives

Modern multi-core processors provide primitives to allow parallel programs to atomically perform selected operations. Unfortunately, the increasing number of gates in such processors leads to a higher probability of faults happening during the computation. In this paper, we perform a comparison between the robustness of such primitives with respect to faults, operating at a functional level. We focus on locks, the most widespread mechanism, and on transactional memories, one of the most promising alternatives. The results come from an extensive experimental campaign based upon simulation of the considered systems. We show that locks prove to be a more robust synchronization primitive, because their vulnerable section is smaller. On the other hand, transactional memory is more likely to yield an observable wrong behaviour in the case of a fault, and this could be used to detect and correct the error. We also show that implementing locks on top of transactional memory increases its robustness, but without getting on par with that offered by locks

Topiramate and severe metabolic acidosis: case report Acidose metabólica grave por topiramato: relato de caso

Topiramate infrequently induces anion gap metabolic acidosis through carbonic anhydrase inhibition on the distal tubule of the nephron - a type 2 renal tubular acidosis. We report on a 40 years old woman previously healthy that developed significant asymptomatic metabolic acidosis during topiramate therapy at a dosage of 100mg/day for three months. Stopping medication was followed by normalization of the acid-base status within five weeks. This infrequent side effect appears unpredictable and should be given careful attention.<br>Topiramato pode produzir raramente uma acidose metabólica através da inibição da anidrase carbônica no túbulo distal do néfron - acidose tubular renal do tipo 2. Relatamos o caso de mulher de 40 anos previamente saudável que desenvolveu quadro de acidose metabólica assintomática grave, sem outra etiologia identificável, durante uso de topiramato na dose de 100mg/dia por três meses. Este efeito colateral, embora infrequente, parece ser imprevisível e requer atenção cuidadosa

2PARMA: Parallel Paradigms and Run-time Management Techniques for Many-core Architectures

The 2PARMA project focuses on the development of parallel programming models and run-time resource management techniques to exploit the features of many-core processor architectures. The main goals of the 2PARMA project are: the definition of a parallel programming model combining component-based and singleinstruction multiple-thread approaches, instruction set virtualisation based on portable byte-code, run-time resource management policies and mechanisms as well as design space exploration methodologies for many-core computing architectures