Application of Shemesh theorem to quantum channels

Completely positive maps are useful in modeling the discrete evolution of quantum systems. Spectral properties of operators associated with such maps are relevant for determining the asymptotic dynamics of quantum systems subjected to multiple interactions described by the same quantum channel. We discuss a connection between the properties of the peripheral spectrum of completely positive and trace preserving map and the algebra generated by its Kraus operators $\mathcal{A}(A_1,\ldots A_K)$. By applying the Shemesh and Amitsur - Levitzki theorems to analyse the structure of the algebra $\mathcal{A}(A_1,\ldots A_K)$ one can predict the asymptotic dynamics for a class of operations

Starość jako czasoprzestrzeń: wokół powieści Wiesława Myśliwskiego

The article describes the category of time and space in Wiesław Myśliwski’s books. The main research tools in the analysis of the material were hermeneutics and subject literature analysis. The particular focus was on how spacetime is perceived by elder characters. The conclusions show how the creation of the world in Myśliwski’s novels correlate with Bakhtin’s concept of chronotope.Artykuł ma na celu opis kategorii czasu i przestrzeni w książkach Wiesława Myśliwskiego. Głównymi narzędziami badawczym w analizie materiału była hermeneutyka oraz analiza reprezentacji literackiej. W szczególności skupiono się na ukazaniu tego, w jaki sposób czasoprzestrzeń postrzegana jest przez bohaterów w podeszłym wieku. Autor wiąże kreację świata przedstawionego w powieściach Myśliwskiego z bachtinowską koncepcją chronotopu

Quality of life measured by OHIP-14 and GOHAI in elderly people from Bialystok, north-east Poland

BACKGROUND: The Oral Health Impact Profile-14 (OHIP-14) and the Geriatric/General Oral Health Assessment Index (GOHAI) have never been compared for a group of the same subjects in the Polish population. The aim of the study was to compare the OHIP-14 and GOHAI measures. METHODS: 178 independently living people over the age of 55 were included in the study. The GOHAI and OHIP-14 measures were used. Other variables included age, gender, self-ratings of oral general health, education, number of missing teeth, chewing problems and dry mouth. RESULTS: The mean age of respondents was 70.8 years. The internal reliability (Cronbach’s alpha) showed a high internal consistency for both measures. Spearman’s rank correlation coefficient between the GOHAI and OHIP-14 scores was 0.81. Using the additive method of creating scores, 1.1% of respondents had the GOHAI score of zero, indicating no impact from oral conditions, while 13.5% of them had an OHIP-14 score of zero. Dental status, partial dentures, chewing problems, dry mouth and self-rated oral health were significantly associated with the results of the GOHAI and the OHIP-14 (Kruskal–Wallis test, Mann–Whitney U test). The numbers of preserved and missing teeth significantly correlated with the GOHAI and the OHIP-14, while DMF was significantly associated with the GOHAI only. 6 individuals with discrepant results were revealed. After the exclusion of the abovementioned patients, the internal reliability (Cronbach’s alpha) still showed a high internal consistency, and the correlation between the GOHAI and OHIP-14 scores using Spearman’s rank-correlation coefficient increased to 0.87. This phenomenon was identified as a “fatigue effect”. CONCLUSIONS: There was a strong correlation between the GOHAI and the OHIP-14. Both instruments demonstrated good discriminant properties and helped capture the respondents’ oral health problems. The questionnaires should be randomly distributed to avoid the influence of “fatigue effect” on the results of a comparison of different measures