[Left ventricular non-compaction: What should be known!] / La non-compaction du ventricule gauche : ce qu'il faut savoir !

Isolated non-compaction of the left ventricle (NCVG) is a rare congenital cardiomyopathy resulting from the shutdown of normal embryogenesis of the myocardium. Its main feature is the existence of many deep heart-related ventricular trabeculations, generally located at the level of the apex of the left ventricle. Diagnosis is based on echocardiography and magnetic resonance imaging (MRI), and may be difficult in the atypical forms. The clinical presentation and the prognosis are very variable. Familial forms are not rare, ordering a family screening.

Efficiency transfer using the GEANT4 code of CERN for HPGe gamma spectrometry.

In this work we apply the GEANT4 code of CERN to calculate the peak efficiency in High Pure Germanium (HPGe) gamma spectrometry using three different procedures. The first is a direct calculation. The second corresponds to the usual case of efficiency transfer between two different configurations at constant emission energy assuming a reference point detection configuration and the third, a new procedure, consists on the transfer of the peak efficiency between two detection configurations emitting the gamma ray in different energies assuming a "virtual" reference point detection configuration. No pre-optimization of the detector geometrical characteristics was performed before the transfer to test the ability of the efficiency transfer to reduce the effect of the ignorance on their real magnitude on the quality of the transferred efficiency. The obtained and measured efficiencies were found in good agreement for the two investigated methods of efficiency transfer. The obtained agreement proves that Monte Carlo method and especially the GEANT4 code constitute an efficient tool to obtain accurate detection efficiency values. The second investigated efficiency transfer procedure is useful to calibrate the HPGe gamma detector for any emission energy value for a voluminous source using one point source detection efficiency emitting in a different energy as a reference efficiency. The calculations preformed in this work were applied to the measurement exercise of the EUROMET428 project. A measurement exercise where an evaluation of the full energy peak efficiencies in the energy range 60-2000 keV for a typical coaxial p-type HpGe detector and several types of source configuration: point sources located at various distances from the detector and a cylindrical box containing three matrices was performed.

Exposure to radiation from the natural radioactivity in Tunisian building materials.

Building materials can expose public and workers to radiation because of their content of radium, thorium and potassium isotopes. This is why it is very important from the radiological point of view to survey the natural radioactivity content of commonly used building materials in any country. This work consists of the measurement of (226)Ra, (232)Th and (40)K activity concentrations in a variety of commonly used building materials in Tunisia and on the estimation of their radiological hazard. The maximum value of radium equivalent for the studied materials was equal to 169 Bq kg(-1) and corresponds to the clay brick, which is lower than the recommended value of 370 Bq kg(-1). In this work, several radiological indexes were calculated and were found to be under their highest permitted limit.

[Incidence of previous engagement in sports among patients with symptomatic arthrosis. Controlled study]. / Fréquence des antécédents de pratique sportive chez les sujets atteints d'arthrose symptomatique. Une étude contrölée.

The authors investigated sports-related precedents in two groups of male subjects, aged 40 years and over, of French nationality. One group had consulted for a degenerative, chronic rheumatic disorder, and the control group showed no signs of this type of disorder. Care was taken to verify that the two groups did not differ in terms of profession, means of commuting from home to work, and non-sporting leisure physical activities. The authors observed that the subjects of the first group (chronic degenerative rheumatic disease) more frequently engaged in a sports activity, and in a significant manner, than did the control subjects. A separate study of the certain kinds of sports and the various arthritic localisations also revealed significant correlations. Although this involved a retrospective enquiry, the authors feel that the results provide arguments in favor of the pathogenic role of sports activity, with regard to peripheral joints and the spine. However, this role of sports is probably only partial and irregular. The risks of sports activity must be put in perspective and balanced with the various advantages afforded by the practice of sports.