Structural differences of microtriches and distal cytoplasm of the tegument in the apical and lateral suckers, scolex proper and neck of Proteocephalus macrocephalus (Creplin,1815) were studied. The microthrix border in the apical sucker is formed by filamentous microtriches only. The frontal and lateral parts of scolex bear mainly filamentous microtriches, but seldom short conoid types occur. The transitional zone between scolex and neck is covered mainly with short conoid microtriches. The neck bears blade-like microtriches. In the apical and lateral suckers, the basal plasma membrane of the distal cytoplasm adheres to the basal lamina at some points only, forming thus a lacunal system at the base of the sucker tegument. In the scolex proper and neck region, the basal plasma membrane of the tegument is connected continuously with the basal lamina. The distal cytoplasm is penetrated by two types of gland cell ducts and cibate sensory receptors. Possible functions of different parts of the microthrix border are discussed.
The social transformation in post-totalitarian countries is characterised by extraordinarily dynamic differentiation tendencies. With respect to social groups and territorial communities, these tendencies differ or are even contradictory, resulting in an internal social and territorial polarisation in the national systems concerned. These polarisation processes are, on the one hand, a reaction to the equalising tendencies in communist countries, and, on the other hand, are the result of the need for qualitative changes to social structures. One such structure is the regional organisation of society, which owing to the heterogeneous nature of the conditions it exists in has very specific features. Essentially it is the environmental organisation of society, where the effects of social and natural factors are combined. Consequently, there is typically a higher level of territorial inequality in the distribution of economic activities than in social distribution, and, by contrast, less variability of geographical differentiation than social differentiation. These features are demonstrated in an empirical analysis of the current development in the Czech Republic, wherein a distinction is made between two ways of assessing regional distribution. First, there is the assessment of differentiation of the territorial intensity of economic activities (economic aggregate/km2). Second, there is the assessment of relative economic and social development (economic aggregate/inhabitant). Despite the differences in the level and variability of the two types of regional differentiation, there are similar trends in their development, heading towards greater inequalities.
The article focuses on representatives of the regional (and most recently established) level of government in the Czech Republic. It describes the context behind the emergence of regional governments and how they differ from the local and national political levels. It notes the close personnel connection between local and regional political elites. Experience gained in local politics helps elites to succeed at the regional level. The presence of local politicians in regional government varies with the level of residential fragmentation and the degree of urbanisation in the given region. Unlike local politics, which is consistently comprised of a significant proportion of independents, regional representatives are almost exclusively members of political parties and movements. This situation on the one hand serves to increase the politicisation of local politics and on the other leads to greater competition within political parties, whose programmes and national leadership regional politicians wish to influence.
A low irradiance mediated regulation of C4 metabolism during acclimation is reported for first time in Amaranthus hypochondriacus L., a NAD-ME dicot, Eleusine coracana (L.) Gaertn., an NAD-ME monocot, and Gomphrena globosa, a NADP-ME dicot. Significant decline in activities of key C4 enzymes were observed under limited irradiances in each of the species studied. When the plants were transferred to full natural irradiance, the enzyme activities were restored to originál State in 3-5 d, a similar time frame needed for acclimation to limiting irradiance. This identifies the decarboxylation reaction involving NAD-ME in Amaranthus and Eleusine or NADP-ME in Gomphrena as crucial sites of regulation under limiting irradiance.
A surprísingly high level of the CPI membrane-bound apoprotein was found through ELISA test in barley coleoptiles, cotnpared with etiolated leaves. Non-synchronous changes of the chlorophyll (Chl) a and CPI apoprotein contents were found in greening etiolated seedlings after brief preinradiation, in green leaves after continuous darkness and the second weak irradiation, and in old leaves after a period of darkness. The complexity of these fmdings gives a possibility of the CPI apoprotein formation without direct cotmection to Chl a biosynthesis. The CPI apoprotein accumulation in young etiolated leaves was stimulated by S-aminolevulinic acid.
Four-d-old seedlings were exposed to ultraviolet-B, UV-B (20 pinol ht^), and UV-B supplemented with red, R {X 612 nin, 5 pmol nr^) or far-red, FR (X 712 nin, 4.5 pmol nr^) radiation for 30 min during the middle of tlie light phase. Three d of UV-B treatment caused reduction in shoot elongation and expansion of cotyledonaiy leaves. The reduction was largely reversed by supplementary R and FR radiations. Supplementation of FR accelerated senescence process. Similar changes were also noted in the contents of photosynthetic piginents, while the level of anthocyanin was enhanced by all treatments. Flavonoid accumulation was enhanced by UV-B, whereas R and FR radiations suppressed its synthesis to various degrees. The chlorophyll (Chl) fluorescence ratio Fy/F,„ and half-rise time of maximum fluorescence were greatly reduced by UV-B and with FR supplementation. R reversed this UV-B inhibition to a great extent. Likewise, tlie P-S dechne was higher under control and +UV-B+R than under +UV-B and +UV-B+FR treatments, At the protein level both the subunits of ribulose 1,5-bisphosphate carboxylase alone were regulated by phytochrome. All these experiments indicated a possible role of phytochrome in regulating the UV-B induced changes in plant morphology and chloroplast proteins.