BACKGROUND/AIM Atrial fibrillation (AF) increases the risk for ischemic stroke and other thromboembolic (TE) events. Aim of the study was to examine the relationship between clinical types of atrial fibrillation (AF) and (TE) events. METHODS This longitudinal, observational study included patients with nonvalvular AF as main indication for in-hospital and/or outpatient treatment in the Cardiology Clinic, Clinical Center of Serbia during a period 1992-2007. The treatment of AF was based on the International Guidelines for diagnosis and treatment of AF, correspondent to given study period. Clinical types of AF were defined according to the latest ACC/AHA/ESC Guidelines for AF, from 2006. Diagnosis of central and systemic TE events during a follow-up was made exclusively by the neurologist and vascular surgeon. RESULTS During a follow-up of 9.9 +/- 6 years, TE events were documented in 88/1 100 patients (8%). In the time of TE event 46/88 patients (52.3%) had permanent AF. The patients with permanent AF were at baseline significantly older and more frequently had underlying heart disease and diabetes mellitus. Cumulative TE risk during follow-up was similar for patients with paroxysmal and permanent AF, and significantly higher as compared to TE risk in patients with persistent AF. However, multivariate Cox proportional hazard regression analysis with independent variables clinical types of AF at baseline and in the time of TE event, clinical and echocardiographic characteristics and therapy for prevention of TE complications at baseline and at the time of TE event, did not reveal independent predictive value of clinical type of AF for the occurrence of TE events during a follow-up. CONCLUSION TE risk in patients with AF does not depend on clinical type of AF. Treatment for prevention of TE events should be based on the presence of well recognized risk factors, and not on the clinical type of AF.

We explore phonon decay processes necessary to the design of efficient rough semiconductor nanowire (NW) thermoelectric devices. A novel approach to surface roughness-limited thermal conductivity of Si, Ge, and GaAs NW with diameter D < 500 nm is presented. In particular, a frequency-dependent phonon scattering rate is computed from perturbation theory and related to a description of the surface through the root-mean-square roughness height Δ and autocovariance length L. Using a full phonon dispersion relation, the thermal conductivity varies quadratically with diameter and roughness as (D/Δ)2. Computed results are in agreement with experimental data, and predict remarkably low thermal conductivity below 1 W/m/K in rough-etched 56 nm Ge and GaAs NW at room temperature.

We study phonons produced by transitions between the equivalent X valleys in silicon. We use the Monte Carlo method first to select stochastically the time between phonon collisions, and then to select a final-state pair of phonons from the probability distribution for anharmonic decay. Our results show that intervalley phonons decay into one near-equilibrium transverse acoustic phonon and another intermediate longitudinal phonon either on the acoustic or optical branch. This second phonon has energies between 40 and 50 meV and undergoes another decay before turning into a pair of near-equilibrium transverse acoustic phonons, presenting an additional potential bottleneck.

This paper presents a system for advanced verbal interactions between humans and artificial agents with the aim to learn a simple language in which words and their meaning are grounded in sensory-motor experiences of the agent, and which allows agents to interact and cooperate with humans in shared environments. The system learns grounded language models from examples with a minimum of user intervention and without feedback, and it has been used to understand and subsequently to generate appropriate natural language descriptions of real objects and to engage in verbal interactions with a human partner.

A taxonomic study into the anatomical, morphological and phytochemical differentiation of the genus Mentha L (Lamiaceae) in Bosnia & Hercegovina and Slovakia is presented. Following a population-based approach and using hierarchical cluster analyses the following basic species and hybrids corresponding to exclusive branches, i.e. groups, in the constructed hierarchies were recognized: Mentha aquatica, M. spicata, M. arvensis, M. longifolia, M. rotundifolia, M. × piperita, M. × villosa, M. × verticillata, M. × gentillis, M. × gracilis and M. pulegium. These groups were independently found by separate analyses of the sampled anatomical and morphological variation. In contrast, these anatomically and morphologically defined species exhibited a high level of phytochemical polymorphism which was largely inconsistent with the hierarchical classification. Among the analysed characters, the inflorescence type, dentation of the leaf margin, hair density, the type of capitate glandular hairs, and the main containing compound in essential oil proved most useful for the discrimination of taxa. However, most of the observed traits were not exclusive to a particular species and only the combined consideration of traits revealed coherent taxonomic groups. Basic species and hybrids are described in detail based on the anatomical, morphological and phytochemical characters used for their definition. The performed cluster analysis finally supported hypotheses on the parentage of some of the studied hybrids.

Charm procceses are usually not considered to be favorable candidates in the search for new physics. Recent disagreement between experimental and lattice QCD results on the D_s decay constant has motivated us to systematically reinvestigate role of leptoquarks in rare charm meson decays. We include constrains coming from the light meson decays.