Towards a realistic Standard Model from D-brane configurations

Effective low energy models arising in the context of D-brane configurations with Standard Model (SM) gauge symmetry extended by several gauged abelian factors are discussed. The models are classified according to their hypercharge embeddings consistent with the SM spectrum hypercharge assignment. Particular cases are analyzed according to their perspectives and viability as low energy effective field theory candidates. The resulting string scale is determined by means of a two-loop renormalization group calculation. Their implications in Yukawa couplings, neutrinos and flavor changing processes are also presented.Comment: 22 pages, 12 EPS figures, some clarifications/references adde

FADE: A programmable filtering accelerator for instruction-grain monitoring

Instruction-grain monitoring is a powerful approach that enables a wide spectrum of bug-finding tools. As existing software approaches incur prohibitive runtime overhead, researchers have focused on hardware support for instruction-grain monitoring. A recurring theme in recent work is the use of hardware-assisted filtering so as to elide costly software analysis. This work generalizes and extends prior point solutions into a programmable filtering accelerator affording vast flexibility and at-speed event filtering. The pipelined microarchitecture of the accelerator affords a peak filtering rate of one application event per cycle, which suffices to keep up with an aggressive OoO core running the monitored application. A unique feature of the proposed design is the ability to dynamically resolve dependencies between unfilterable events and subsequent events, eliminating data-dependent stalls and maximizing accelerator’s performance. Our evaluation results show a monitoring slowdown of just 1.2-1.8x across a diverse set of monitoring tools

Death and myocardial infarction following initial revascularization versus optimal medical therapy in chronic coronary syndromes with myocardial ischemia: A systematic review and meta-analysis of contemporary randomized controlled trials

Background In chronic coronary syndromes, myocardial ischemia is associated with a greater risk of death and nonfatal myocardial infarction (MI). We sought to compare the effect of initial revascularization with percutaneous coronary intervention (PCI) or coronary artery bypass grafting (CABG) plus optimal medical therapy (OMT) with OMT alone in patients with chronic coronary syndrome and myocardial ischemia on long-term death and nonfatal MI. Methods and Results Ovid Medline, Embase, Scopus, and Cochrane Library databases were searched for randomized controlled trials of PCI or CABG plus OMT versus OMT alone for patients with chronic coronary syndromes. Studies were screened and data were extracted independently by 2 authors. Random-effects models were used to generate pooled treatment effects. The search yielded 7 randomized controlled trials that randomized 10 797 patients. Median follow-up was 5 years. Death occurred in 640 of the 5413 patients (11.8%) randomized to revascularization and in 647 of the 5384 patients (12%) randomized to OMT (odds ratio [OR], 0.97; 95% CI, 0.86-1.09