G-Compactness and Groups

Lascar described E_KP as a composition of E_L and the topological closure of EL. We generalize this result to some other pairs of equivalence relations. Motivated by an attempt to construct a new example of a non-G-compact theory, we consider the following example. Assume G is a group definable in a structure M. We define a structure M_0 consisting of M and X as two sorts, where X is an affine copy of G and in M_0 we have the structure of M and the action of G on X. We prove that the Lascar group of M_0 is a semi-direct product of the Lascar group of M and G/G_L. We discuss the relationship between G-compactness of M and M_0. This example may yield new examples of non-G-compact theories.Comment: 18 page

Computed tomography in the evaluation of the anomalous origin of the coronary artery: coexistence with other congenital heart disease in an adult population

Background: The aim of the study is to assess the prevalence of anomalous origin of the coronary artery in cardiac computed tomography (CT) and to evaluate its coexistence with other congenital heart disease. Materials and methods: 7,115 patients, who underwent 64-slice or dual source cardiac CT in the years 2005–2011 were screened for the presence of anomalous origin of the coronary artery. Results: Anomalous origin of coronary artery was found in 62 (0.87%) patients (34 males, mean age 57.4 ± 15.1 years). Anomalous aortic and pulmonary origin of coronary artery concerned 59 (0.83%) and 3 (0.04%) cases, respectively. Concomitant heart defects were observed in 5 (0.07%) patients, all with anomalous aortic origin of coronary artery. Malformations included transposition of great arteries (4 patients) and single ventricle in (1 patient). Conclusions: The incidence of anomalous origin of a coronary artery in cardiac CT is similar to invasive coronary angiography. In an adult population the vast majority of those anomalies are isolated abnormalities without concomitant other congenital heart defects

Cosmic Ray Extremely Distributed Observatory: a global network of detectors to probe contemporary physics mysteries

In the past few years, cosmic-rays beyond the GZK cut-off ($E > 5 \times 10^{19}$ eV) have been detected by leading collaborations such as Pierre Auger Observatory. Such observations raise many questions as to how such energies can be reached and what source can possibly produce them. Although at lower energies, mechanisms such as Fermi acceleration in supernovae front shocks seem to be favored, top-down scenarios have been proposed to explain the existence of ultra-high energy cosmic-rays: the decay of super-massive long-lived particles produced in the early Universe may yield to a flux of ultra-high energy photons. Such photons might be presently generating so called super-preshowers, an extended cosmic-ray shower with a spatial distribution that can be as wide as the Earth diameter. The Cosmic Ray Extremely Distributed Observatory (CREDO) mission is to find such events by means of a network of detectors spread around the globe. CREDO's strategy is to connect existing detectors and create a worldwide network of cosmic-ray observatories. Moreover, citizen-science constitutes an important pillar of our approach. By helping our algorithms to recognize detection patterns and by using smartphones as individual cosmic-ray detectors, non-scientists can participate in scientific discoveries and help unravel some of the deepest mysteries in physics.Comment: excited QCD Conference, CREDO Collaboration, 7 pages, 3 figure

Topographical anatomy of the left ventricular summit: implications for invasive procedures

Background: Recent clinical reports have emphasized the clinical significance of the left ventricular summit (LVS), a specific triangular epicardial area, as the source of ventricular arrhythmias where radiofrequency ablation is of great difficulty. Materials and methods: The macroscopic morphology of the LVS has been assessed in 80 autopsied and 48 angio-CT human hearts. According to Yamada’s equation, the size was calculated based on the distance to the first, most prominent septal perforator. Results: The size of the LVS varies from 33.69 to 792.2 mm2, is highly variable, and does not correlate with BMI, sex, or age in general. The mean size of the LVS was 287.38 ± 144.95mm2 in autopsied and angio-CT (p=0.44). LVS is mostly disproportionately bisected by cardiac coronary veins to superior – inaccessible and inferior–accessible areas. The superior aspect dominates over the inferior in both groups (p=0.04). The relation between superior and inferior groups determines three possible arrangements: the most common type is superior domination (50.2%), then inferior domination (26.6%), and finally, equal distribution (17.2%). In 10.9 %, the inferior aspect is absent. Only 16.4% of the LVS were empty, without additional trespassing coronary arteries. Conclusions: The difference in size and content of the LVS is significant, with no correlation to any variable. The size depends on the anatomy of the most prominent septal perforator artery. The superior, inaccessible aspect dominates, and the LVS is seldom free from additional coronary vessels, thus making this region hazardous for electrophysiological procedures

Zastosowanie wybranych testów statystycznych w badaniach pomiarów wysokościowych.

The following paper presents a comparative application of three selected tests (L’Abbé’s, Kolmogorov’s, and Kuiper’s) in order to verify the normality of the distribution of measurement errors in precise levelling. The calculations were made on the basis of observations obtained from the levelling test network, established at the LZD experimental station in Krynica. The tests subjected to the comparison have demonstrated that the distribution of error in the studied tests is a normal distribution, and that there are no systematic errors in the measurements.Poniższa praca przedstawia porównanie wykorzystania trzech wybranych testów (Abbe`go, Kołmogorowa i Kuipera) w celu sprawdzenia normalności rozkładu błędów pomiarowych w niwelacji precyzyjnej. Obliczeń dokonano na podstawie obserwacji uzyskanych z testowej sieci niwelacyjnej założonej w LZD Krynica. Porównane testy wykazały, że rozkład w błędu w badanych testach jest rozkładem normalnym, oraz, że nie występują błędy systematyczne w pomiarach