Progress and status of APEmille

We report on the progress and status of the APEmille project: a SIMD parallel computer with a peak performance in the TeraFlops range which is now in an advanced development phase. We discuss the hardware and software architecture, and present some performance estimates for Lattice Gauge Theory (LGT) applications.Comment: Talk presented at LATTICE97, 3 pages, Late

The Impact of Sprint Exercise Training on Vascular Functions in 50-70 y Olds

PURPOSE: Aging is a major risk factor for the development of cardiovascular disease due in part to increased oxidative stress and arterial stiffening. Lifestyle modifications, such as exercise, are among the first-line of approach for preventing vascular dysfunction. Exercise training has been shown to foster antioxidant states and improve vascular health. Therefore, the purpose of this study was to determine the effect of 8-weeks of sprint exercise training using inertial loading on vascular health in 50-70 y old. METHODS: Thirty-one apparently healthy middle-aged and older adults (59 ± 5 years, 17 females) participated in the study. The participants performed 15 sprints per training session week 1, 20 sprints per session weeks 2-4 and 30 sprints per session weeks 5-8 with 56s, 41s, and 26s of rest, respectively, between sprints. Training sessions occurred three times per week for 8 weeks. Each sprint consisted of 4s of all-out cycling where the participants accelerated a heavy flywheel from a stationary position to maximal angular velocity. They were instructed to keep pedaling throughout the duration of the 4s to achieve maximal power and cadence. Baseline and post intervention measurements of flow-mediated dilation (FMD; index of endothelium-dependent vasodilation), cardio-ankle vascular index (CAVI; indicator of arterial stiffness), and arterial blood pressure were made. RESULTS: CAVI decreased significantly following the 8-weeks of inertial load exercise training (2.38%; p=0.048). Additionally, grouping the participants by age or sex did not influence the reduction observed with CAVI. However, FMD and blood pressure did not change significantly (p≥0.05). CONCLUSIONS: The 8-weeks of exercise training using an inertial load ergometer decreased arterial stiffness in men and women 50-70 y. Future studies are needed to determine the efficacy of this type of exercise intervention in clinical populations to improve vascular function

The PeakSum processing system for the NA48 experiment: A VLSI based processor

The PeakSum Processing System (PSS) is an element of the neutral trigger of the NA48 experiment at CERN. The PSS is a pipelined processor based on a VLSI semi-custom device, containing all the processing blocks needed in the system. The PSS provides information on the energy pattern released in the electromagnetic calorimeter of the NA48 experiment, used to identify K-0 double right arrow pi(0) pi(0) double right arrow 4 gamma decays

Potential risk of myopathy by HMG-CoA reductase inhibitors: a comparison of pravastatin and simvastatin effects on membrane electrical properties of rat skeletal muscle fibers

To get insight into the potential risk of myopathy associated with therapy involving 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors, we evaluated in vivo and in vitro the effects of a daily 2 to 3-month treatment with pravastatin (100 mg/kg) and with simvastatin (5, 10 and 50 mg/kg) on the electrical properties of rat skeletal muscle fibers. The electromyographic activity revealed no sign of myopathy during treatment with pravastatin and with simvastatin. At the end of the treatment, the passive and active membrane electrical parameters of the extensor digitorum longus muscles were measured in vitro by computerized two-intracellular-microelectrode technique. A dose-dependent reduction of membrane chloride conductance was recorded in extensor digitorum longus fibers of simvastatin-treated groups, and at 50 mg/kg the reduction of chloride conductance was significant in 6 out of the 7 treated rats. By contrast, none of the pravastatin-treated rats showed significant alteration of chloride conductance. Consequently, the excitability parameters were modified by simvastatin but not by pravastatin treatment, whereas the resting membrane potential was not affected. An increase in potassium conductance, reduced by in vitro application of glybenclamide, was recorded in 30% of the simvastatin-treated rats (50 mg/kg) and in only 15% of the pravastatin-treated rats. Our results suggest that the risk of myopathy is much higher with the lipophilic simvastatin than with the hydrophilic pravastatin and support the hypothesis that the muscle toxicity of HMG-CoA reductase inhibitors is due to an intracellular action mediated by the inhibition of muscle cholesterol synthesis

An overview of the APEmille parallel computer

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A 40 MHz pipelined trigger for K-0 -> 2 pi(0) decays for the CERN NA48 experiment

A first level trigger system based on a 40 MHz digital pipeline has been developed for the CERN NA48 [1] experiment, aiming at measuring CP violation in K-0 --> 2 pi decays.The outputs of the 13340 cells of the 10 m(3) liquid krypton calorimeter are summed into 64 X and 64 Y projection strips and continuously digitised with 40 MHz FADCs.This information is used to reconstruct at each clock cycle and for the two calorimeter projections, the number of clusters, the impact time of each of them (with a precision of about 3 ns), their total energy and the first and second moments of the energy distribution.Based on the quantities listed above, a programmable look-up table system subsequently computes online the longitudinal position of the kaon decay vertex and performs an event selection.The system is described

The teraflop supercomputer APEmille: architecture, software and project status report

APEmille is a SPMD parallel processor under development at INFN, Italy, in cooperation with DESY, Germany. APEmille is suited for grand challenges computational problems such as QCD simulations, climate modelling, neural networks, computational chemistry, numerical wind tunnels, seismic and combustion simulations. Its 1 Teraflop/s peak performance and its architecture, together with its language features, allow such applications to execute effectively.APEmille is based on an array of custom arithmetic processors arranged on a tridimensional torus. The processor is optimized for complex computations and has a peak performance of 528 Mflop at 66 MHz. Each processing element has 8 Mbytes of locally addressable RAM.On the software side particular emphasis is devoted to the programming languages that will be available (TAO and C++) and their object oriented, dynamic characteristics: with TAO it is possible to develop language extensions similar to the usual HEP notation; with C++ the portability from and towards different platforms is made possible

An Overview of the APEmille Project

This paper describes the main architectural features of the APEmille parallel architecture. It covers in some details the hardware and software details of this machine, now in an advanced development phase. It finally presents a status report of the project