Response to peginterferon plus ribavirin and subsequent retreatment with telaprevir-based triple therapy in a patient with chronic lymphocytic leukaemia and chronic HCV genotype 1b infection

BACKGROUND: Case-controlled studies have clearly demonstrated a link between chronic hepatitis C infection (CHC) and B cell non-Hodgkin lymphoma (NHL). To our knowledge, this is the first case report of outcome in a patient with CLL and chronic HCV infection treated with PEG-IFN/RBV and subsequent retreated with triple therapy. FINDINGS: We report the case of a 54-year old, caucasian woman with a history of elevated liver enzymes diagnosed with chronic lymphocytic leukaemia (CLL) detected during investigation for hepatitis C (HCV) infection. The patient showed a haematological response following initially successful anti-HCV therapy with peginterferon plus ribavirin (PEG-IFN/RBV), with normalization of leukocyte and lymphocyte counts. She subsequently showed a late virological relapse at week 24, and was successfully retreated with telaprevir-based triple therapy. Despite an increase in leucocyte and lymphocyte count compared to baseline following triple therapy, to date there is no evidence of progression of CLL and the patient remains asymptomatic. CONCLUSION: Patients with CLL may experience haematological response following successful anti-HCV therapy using IFN-based regimens. Re-treatment with triple therapy including telaprevir following late virological relapse was successful, was not associated with any unexpected safety issues, and did not adversely affect CLL status

Dynamics of bad-cavity enhanced interaction with cold Sr atoms for laser stabilization

Hybrid systems of cold atoms and optical cavities are promising systems for increasing the stability of laser oscillators used in quantum metrology and atomic clocks. In this paper we map out the atom-cavity dynamics in such a system and demonstrate limitations as well as robustness of the approach. We investigate the phase response of an ensemble of cold strontium-88 atoms inside an optical cavity for use as an error signal in laser frequency stabilization. With this system we realize a regime where the high atomic phase-shift limits the dynamical locking range. The limitation is caused by the cavity transfer function relating input field to output field. However, the cavity dynamics is shown to have only little influence on the prospects for laser stabilization making the system robust towards cavity fluctuations and ideal for the improvement of future narrow linewidth lasers.Comment: 10 pages, 7 figure

From Lagrangians to Events: Computer Tutorial at the MC4BSM-2012 Workshop

This is a written account of the computer tutorial offered at the Sixth MC4BSM workshop at Cornell University, March 22-24, 2012. The tools covered during the tutorial include: FeynRules, LanHEP, MadGraph, CalcHEP, Pythia 8, Herwig++, and Sherpa. In the tutorial, we specify a simple extension of the Standard Model, at the level of a Lagrangian. The software tools are then used to automatically generate a set of Feynman rules, compute the invariant matrix element for a sample process, and generate both parton-level and fully hadronized/showered Monte Carlo event samples. The tutorial is designed to be self-paced, and detailed instructions for all steps are included in this write-up. Installation instructions for each tool on a variety of popular platforms are also provided.Comment: 58 pages, 1 figur

Lasing on a narrow transition in a cold thermal strontium ensemble

Highly stable laser sources based on narrow atomic transitions provide a promising platform for direct generation of stable and accurate optical frequencies. Here we investigate a simple system operating in the high-temperature regime of cold atoms. The interaction between a thermal ensemble of $^{88}$Sr at mK temperatures and a medium-finesse cavity produces strong collective coupling and facilitates high atomic coherence which causes lasing on the dipole forbidden $^1$S$_0 \leftrightarrow ^3$P$_1$ transition. We experimentally and theoretically characterize the lasing threshold and evolution of such a system, and investigate decoherence effects in an unconfined ensemble. We model the system using a Tavis-Cummings model, and characterize velocity-dependent dynamics of the atoms as well as the dependency on the cavity-detuning.Comment: 9 pages, 7 figure

Multi-Pitch Estimation Exploiting Block Sparsity

We study the problem of estimating the fundamental frequencies of a signal containing multiple harmonically related sinusoidal components using a novel block sparse signal representation. An efficient algorithm for solving the resulting optimization problem is devised exploiting a novel variable step-size alternating direction method of multipliers (ADMM). The resulting algorithm has guaranteed convergence and shows notable robustness to the f 0 vs f0/2f0/2 ambiguity problem. The superiority of the proposed method, as compared to earlier presented estimation techniques, is demonstrated using both simulated and measured audio signals, clearly indicating the preferable performance of the proposed technique