Two series of new thermoplastic poly(thiourethane-urethane) elastomers (EPTURs), with different hardsegment content (40-60 wt%), were synthesized by a onestep melt polymerization from poly(oxytetramethylene) diol (PTMO) of M n = 1,000 g mol -1 or poly(hexamethylene carbonate) diol (PHCD) of M n = 860 g mol -1 as a soft segment, hexane-1,6-diyl diisocyanate and (methylenedi-1,4-phenylene)dimethanethiol as a chain extender at the NCO/(OH ? SH) molar ratio of 1. The structures of all the EPTURs were examined by Fourier transform infrared spectroscopy (FTIR), atomic force microscopy and X-ray diffraction analysis. Their thermal behavior was investigated by means of differential scanning calorimetry and thermogravimetric analysis (TG). For the chosen polymers the gaseous products evolved during the decomposition process were analyzed by TG-FTIR. Moreover, physicochemical, adhesive and tensile properties as well as Shore A/D hardness were determined. The resulting highmolecular-mass EPTURs were stable up to 254-262°C, as measured by the temperature of 1 % mass loss. They decomposed in three or four stages. The main decomposition products were carbonyl sulfide, isocyanate, carbon dioxide, aromatic hydrocarbons as well as aliphatic ethers and aldehydes (in PTMO series) and alcohols (in PHCD series). All the polymers showed partially crystalline structures, associated with crystallization of thiourethane hard segments. Their melting temperatures were in the range of 184-186°C. The PTMO series EPTURs exhibited better low-temperature properties (glass-transition temperature in the range of -64 to -44 vs. -26 to -22°C), but poorer tensile strengths (20-28 vs. 37-43 MPa). These EPTURs showed improved adhesive properties in comparison with their polyurethane analogs.

The categories of the rural population, farmers, farm-workers and landless rural inhabitants were variously affected by the economic crisis, as well as by the process of economic transformation. This shows that living conditions of each of those categories changed in different ways and to a different degree during the years 1967-2001. Farmers' families achieved the highest social advancement, as the AM of girls from those families decreased by 0.98 years compared to those from farmer-worker and landless rural families, which decreased by 0.85 and 0.60 years, respectively.

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The age at menarche, body height and weight of the daughters of farmers, farmer-workers and landless villagers in a rural region of Poland were studied. In the period 1967-1977, a time of economic development, a decrease in age at menarche (by 0.74 years) and a secular trend in body height (by 2.4 cm/decade) was observed. In 1977-1987, a period of acute economic crisis, age at menarche increased by 0.16 years and the secular trend in body height was only 1.1 cm/decade. In 1987-2001, age at menarche decreased and body height increased by 0.28 years and 2.9 cm respectively. The percentage of families owning a car, freezer and video increased during this period. These last results are indicative of an improvement in living conditions, but the villagers regard themselves as losers as a result of the political transformation (1989) in Poland.

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The aim of the study is to present social distances in biological development of youth in the period of changes in economic and political situation in Poland.Material and methods: 1. Nationwide study of children and adolescents aged 7.5 to 19.5 years started in 1979 and repeated every decade till 2009, 2. Survey conducted in the region of eastern Poland in 1987 and 2007, 3. Study of rural girls repeated four times between 1967 and 2001. The differences in body height and age at menarche between the inhabitants of towns and rural areas, as well as the differences between rural girls determined by diversified source of income for the family, will be presented. The age at menarche (AM) in each study was calculated using probit method. A monotonic decrease in body height differences between the inhabitants of towns, and girls living in rural areas was observed. On the basis of nationwide studies arithmetic means of the differences in terms of age were 1.9 cm in 1979 and 0.82 in 2009. At the same time, differences in the AM among girls in compared agglomerations decreased from 0.36 to 0.26, respectively. In eastern region of Poland the difference in body height between the residents of towns and villages in 1987 was 1.76 cm, and in 2007, only 0.38 cm; the difference of AM decreased from 0.41 to 0.14 years.The research conducted on inhabitants of rural areas has shown the earliest maturation and slightly greater body height for girls from landless families and the latest maturation and the smallest body height for the daughters of farmers. The differences in AM between the two groups decreased from 0.53 years in 1967 to 0.15 in 2001.The political transformation (1989) unequally influenced people on different levels of urbanization, different socio-professional groups and residents of various regions of the country, but was reflected in the results of anthropological research.The largest social advancement measured in terms of acceleration of maturation in the period covered by the research was characteristic for rural girls, especially the daughters of farmers.

Unemployment in the Polish countryside and its effect on the development and rate of maturation of rural girlsThe aim of this study is to assess the biological status of girls from landless rural families - daughters of working fathers, and those of unemployed fathers. The measures include age at menarche, body height and weight, and the body mass index (BMI). The study of rural girls was conducted in 2001; a total of 9599 girls aged 9-18 were examined. The material used in the present article only embraces girls from non-farming rural families (N = 4476). It was divided into daughters of working fathers (86.5%) and those of unemployed fathers (13.5%). Daughters of working fathers mature earlier than those of unemployed fathers. The difference in the age at menarche is 0.39 years and is statistically significant. The age at menarche of daughters of unemployed fathers approximates the menarchal age of daughters from farming families with many children (5 or more) in which both parents have elementary education. In groups similar in terms of the father's education and the number of children in the family, daughters of unemployed fathers display a later age at menarche and a lower body height and weight. These results support the statement that a father's lack of employment affects the biological status of his daughters.