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Recognition of Households Consumption Preferences' Profiles

100%

Kuszewski T. , Sokolinska A. , Zakrzewska K.

Roczniki Kolegium Analiz Ekonomicznych

2007

tom 17

19-40

This article shows the results of the households' income and expenditures analysis. Special attention was given to the relation between food and alcohol-free beverages in general expenditures and social-demographic characteristics. Three criteria of households' division were introduced. The households were divided according to the main source of maintenance, according to number of members in the household, according to the economic situation. As a result of these steps we got 18 households subsets. For each subset the linear econometric models were estimated and verified. These models illustrate the Engel's Law. In the next step of analysis the classification rules were generated with use of data mining techniques. Data mining analysis was made for the same subsets as previously econometric models. As an output we got the rules with economic interpretation, allowing for complement of households' characteristics resulting from research based on econometric techniques.

Modelling the frequencies of chromosomal aberrations in peripheral lymphocytes of patients undergoing radiotherapy

88%

Urbanik W. , Kukołowicz P. , Kuszewski T. , Góźdź S. , Wójcik A.

2003

tom Vol. 48, nr 1

3-8

Recently, several attempts have been undertaken to correlate in vitro calibration curves with observed frequencies of chromosomal aberrations and micronuclei in lymphocytes of patients undergoing radiotherapy. The aim of such correlations is the search for a biological method to reconstruct the dose received during radiotherapy. While the in vitro dose-response curves are linear-quadratic, the observed in vivo relationship is usually linear and there is some controversy as to the nature of the observed linearity. We have, therefore, constructed a model to calculate the frequencies and distributions of chromosomal aberrations in lymphocytes of patients undergoing conventional radiotherapy. The model assumes that each fraction of radiation induces a certain number of Poisson-distributed aberrations in the irradiated blood volume. In addition, a simplified assumption is made that lymphocytes flow freely inside the body of the patient and no elimination of cells occurs. The model yields linear dose response curves. The steepness of the curves increases with increasing size of irradiated block of tissue (referred to as irradiated volume) and increasing dose per fraction. The distributions of aberrations become increasingly overdispersed with increasing dose per fraction but are independent of the number of radiation fractions. The modelled dose-response curves agree well with the majority of published experimental results. Given the simple assumptions made, this indicates that cell elimination, which occurs during radiotherapy does not bias the results obtained experimentally. The linearity of the dose response-curve results from the fractionated irradiation. Hence, great care should be applied when attempting to use standard, linear-quadratic calibration curves to estimate the doses received by patients during radiotherapy.