RESUMO
We describe a fully GPU-based implementation of the first level trigger for the upgrade of the LHCb detector, due to start data taking in 2021. We demonstrate that our implementation, named Allen, can process the 40 Tbit/s data rate of the upgraded LHCb detector and perform a wide variety of pattern recognition tasks. These include finding the trajectories of charged particles, finding proton-proton collision points, identifying particles as hadrons or muons, and finding the displaced decay vertices of long-lived particles. We further demonstrate that Allen can be implemented in around 500 scientific or consumer GPU cards, that it is not I/O bound, and can be operated at the full LHC collision rate of 30 MHz. Allen is the first complete high-throughput GPU trigger proposed for a HEP experiment.
RESUMO
The evidence that there is intracellular compartmentalization of potassium is indirect but diverse. Intracellular electrode measurement of potassium activity, 42K radioisotope studies, and more recently 39K nuclear magnetic resonance (NMR) all support such compartmentalization. The use of rubidium to apparently shift potassium between sites with different NMR characteristics (visibility) is strong evidence for such compartmentalization. The evidence that intracellular compartmentalization of potassium is of (patho) physiological significance is also indirect. Postulated roles for regulation of intracellular K+ activity, perhaps by control of compartmentalization, include enzyme activity, protein synthesis, and cell growth. There is also evidence that compartmentalization of potassium may contribute to the maintenance of a stable intracellular environment following potassium loading. The apparent magnetic field dependence of the visibility of K+ by 39K NMR offers the opportunity to explore further the phenomenon of compartmentalization.
