No abstract

In this article we present the results of a study in which we tested the use of the experimental inventory BRI (Bonding Representations Inventory), developed by Cynthia J. Luxford and Stacey Lowery Bretz. The aim of our study was to test the usability of the experimental instrument in the Slovak educational system and to identify concrete misconceptions in the theme of chemical bonding. In the conclusion, we compare the results obtained with the use of BRI in the USA educational system and the Slovak educational system. We point to the possibility of using BRI in a different educational system. The results of the prestudy and the main study showed that the BRI diagnostic instrument for identifying students' misconceptions is applicable outside the USA didactic system, for which it was developed.

A statistical comparison of the clinical picture in the 2 surgically treated groups failed to reach statistical significance. Nevertheless, a trend toward better clinical picture in the steroid mix group was observed. Paradoxically, when statistically compared, the rate of EF build-up was found greater in the steroid-treated group. A 5% statistical significance was established in the correlation between the presence of EF and the patients' subjective rating (difference between input and output visual analog scale).

Our study finds that per cent stenosis measurement obtained by angiography with NASCET or ECST methods does not reliably reflect the anatomical degree of per cent stenosis, which makes questionable the rigorous following of percentage stenosis using angiography as the sole indicator for carotid endarterectomy in all cases.

A b s t r a c tCough is the most common symptom of many respiratory diseases. Currently, no standardized methods exist for objective monitoring of cough, which could be commercially available and clinically acceptable. Our aim is to develop an algorithm which will be capable, according to the sound events analysis, to perform objective ambulatory and automated monitoring of frequency of cough. Because speech is the most common sound in 24-hour recordings, the first step for developing this algorithm is to distinguish between cough sound and speech. For this purpose we obtained recordings from 20 healthy volunteers. All subjects performed continuous reading of the text from the book with voluntary coughs at the indicated instants. The obtained sounds were analyzed using by linear and non-linear analysis in the time and frequency domain. We used the classification tree for the distinction between cough sound and speech. The median sensitivity was 100% and the median specificity was 95%. In the next step we enlarged the analyzed sound events. Apart from cough sounds and speech the analyzed sounds were induced sneezing, voluntary throat and nasopharynx clearing, voluntary forced ventilation, laughing, voluntary snoring, eructation, nasal blowing and loud swallowing. The sound events were obtained from 32 healthy volunteers and for their analysis and classification we used the same algorithm as in previous study. The median sensitivity was 86% and median specificity was 91%. In the final step, we tested the effectiveness of our developed algorithm for distinction between cough and non-cough sounds produced during normal daily activities in patients suffering from respiratory diseases. Our study group consisted from 9 patients suffering from respiratory diseases. The recording time was 5 hours. The number of coughs counted by our algorithm was compared with manual cough counts done by two skilled co-workers. We have found that the number of cough analyzed by our algorithm and manual counting, as well, were disproportionately different. For that reason we have used another methods for the distinction of cough sound from non-cough sounds. We have compared the classification tree and artificial neural networks. Median sensitivity was increasing from 28% (classification tree) to 82% (artificial neural network), while the median specificity was not changed significantly. We have enlarged our characteristic parameters of the Mel frequency cepstral coefficients, the weighted Euclidean distance and the first and second derivative in time. Likewise the modification of classification algorithm is under our interest.