Computing Quantum Mean Values in the Deep Chaotic Regime.

We study the time evolution of mean values of quantum operators in a regime plagued by two difficulties: the smallness of ℏ and the presence of strong and ubiquitous classical chaos. While numerics become too computationally expensive for purely quantum calculations as ℏ→0, methods that take advantage of the smallness of ℏ-that is, semiclassical methods-suffer from both conceptual and practical difficulties in the deep chaotic regime. We implement an approach which addresses these conceptual problems, leading to a deeper understanding of the origin of the interference contributions to the operator's mean value.

Thermalization slowing down in multidimensional Josephson junction networks.

We characterize thermalization slowing down of Josephson junction networks in one, two, and three spatial dimensions for systems with hundreds of sites by computing their entire Lyapunov spectra. The ratio of Josephson coupling E_{J} to energy density h controls two different universality classes of thermalization slowing down, namely, the weak-coupling regime, E_{J}/h→0, and the strong-coupling regime, E_{J}/h→∞. We analyze the Lyapunov spectrum by measuring the largest Lyapunov exponent and by fitting the rescaled spectrum with a general ansatz.

Attosecond Real-Time Observation of Recolliding Electron Trajectories in Helium at Low Laser Intensities.

Laser-driven recollision physics is typically accessible only at field intensities high enough for tunnel ionization. Using an extreme ultraviolet pulse for ionization and a near-infrared (NIR) pulse for driving of the electron wave packet lifts this limitation. This allows us to study recollisions for a broad range of NIR intensities with transient absorption spectroscopy, making use of the reconstruction of the time-dependent dipole moment.

Quantum-Chaotic Evolution Reproduced from Effective Integrable Trajectories.

Classically integrable approximants are here constructed for a family of predominantly chaotic periodic systems by means of the Baker-Hausdorff-Campbell formula. We compare the evolving wave density and autocorrelation function for the corresponding exact quantum systems using semiclassical approximations based alternatively on the chaotic and on the integrable trajectories. It is found that the latter reproduce the quantum oscillations and provide superior approximations even when the initial coherent state is placed in a broad chaotic region.

Meat consumption, cooking methods, mutagens, and risk of squamous cell carcinoma of the esophagus: a case-control study in Uruguay.

The role of meat in squamous cell carcinoma of the esophagus (ESCC) has been considered conflictive. For this reason, we decided to conduct a case-control study on meat consumption and ESCC. Data included 234 newly diagnosed and microscopically examined ESCC and 2,020 controls with conditions not related to tobacco smoking nor alcohol drinking and without changes in their diets.

Maté consumption and risk of cancer: a multi-site case-control study in Uruguay.

In the time period 1990-2004 we conducted a multisite case-control study in order to examine the relationship of mate consumption and risk of 13 cancer sites in Montevideo, Uruguay. The study included 13,201 participants (8,875 cases and 4,326 controls) drawn from the four major public hospitals in the city of Montevideo. Newly diagnosed and microscopically confirmed cases of cancers of the mouth, pharynx, esophagus, stomach, colon, rectum, larynx, lung, female breast, cervix uteri, prostate, bladder and kidney were included in the study.

Dietary patterns and risk of colorectal cancer: a factor analysis in uruguay.

In the time period 1996-2004, a case-control study of colorectal cancer was conducted in Montevideo, Uruguay. The study included 610 cases and 1,220 controls, frequency matched for age, sex, and residence. All cases were newly diagnosed and microscopically confirmed and controls were drawn from the same hospitals.

Dietary patterns and risk of ductal carcinoma of the breast: a factor analysis in Uruguay.

Breast cancer (BC) shows very high incidence rates in Uruguayan women. The present factor analysis of ductal carcinoma of the breast, the most frequent histological type of this malignancy both in Uruguay and in the World, was conducted at a prepaid hospital of Montevideo, Uruguay. We identified 111 cases with ductal BC and 222 controls with normal mammograms.