The contribution includes several remarks on the subject matter of the study of the contemporary Czech ethnomusicology. Some topics and methods are based on the research conducted in the second half of the 20th century: monographical study of singers and musicians, singing skills of the youngest generation, singing in the city with the use of sociological methods.Other methods developed after 1989, e.g. the study of religious songs and their relation to secular songs.The area which has seen remarkable development during the last twenty years is publishing, especially the publication of song editions in printed and audio forms. Interdisciplinary
cooperation is also developing, namely cooperation with music studies, history, psychology, literary science or linguistics, especially with regard to the study of ethnic stereotypes, contemporary ethnocultural tradition, liturgical songs or fair traditions.The contemporary research in the field of ethnomusicology goes beyond the area of the so-called
“genuine folk songs” and includes various genres belonging to the area of non-artificial music.
In greening mustard cotyledons, both photosystems (PS) 1 and 2 were significantly promoted by addition of gibberelic acid (GA) at low concentrations, i.e. upto 10 μΜ, while at higher concentrations no significant changes were recorded. PS2 activity in kinetin (KN) treated seedlings was promoted at concentrations upto 5 μΜ KN, while it showed a slight inhibition at higher concentrations. No significant change in PS1 activity was observed when compared to controls. Other particular photosynthetic electron transport reactions were also increased by GA and KN. KN03 showed concentration-dependent effects on photosynthetic electron transport reactions.
Quercetin, rutin and phioridzin inhibited the activity of glyceraldehyde-3-phosphate dehydrogenase (GPD) complex from spinách leaves. At a concentiation of 5 X 10'5 M they decreased the rate of 3-phosphoglycerate (PGA) leduction by 90, 50- 80 and 30-40 % , respectively. The activity of the effectors depended on the tiine of isolation of enzymes and the corresponding level of endogenic phenolic compounds. To estimate the effect of the last factor, the enzj^e preparation was obtained in the presence and in the absence of insoluble polyvinylpyrrolidone (Polyciar AT). Using rutin it was shown that in the absence of endogenic phenols the inhibition of PGA reduction was decreased as compared with the variant without Polyciar AT. The effect of rutin was constant during the day. On the basis of data obtained the flavonoids are supposed to inhibit the Benson-Calvin cycie at its reducing stage; this effect may be cooperative and depend on quantitative and qualitative content of endogenic phenolic compounds.
The type species of the genus Glossocercus Chandler, 1935, G. cyprinodontis Chandler, 1935, was described as metacestode (larval stage) from the mesentery of the sheepshead minnow fish (Cyprinodon variegatus Lacépède) from Galveston Bay, Texas. The description was based on the morphology of the rostellar hooks; however, the features of the internal morphology of the proglottides could no be provided. In the present study we describe for the first time the features of the adult G. cyprinodontis from the intestine of Pelecanus occidentalis Linnaeus, Nycticorax nycticorax Linnaeus and Egretta rufescens Gmelin in Mexico. Glossocercus cyprinodontis possesses similar strobilar morphology with the two other congeneric species, both distributed in the Neartic and Neotropical regions, i.e. Glossocercus caribaensis (Rysavy et Macko, 1971) and Glossocercus auritus (Rudolphi, 1819). However, G. cyprinodontis differs mainly in the shape of the rostellar hooks (those of G. cyprinodontis possess the handle and the guard strongly sclerified compared to those of G. auritus and G. caribaensis) and their size (total length of 175-203 mm in G. cyprinodontis compared to 189-211 mm in G. caribaensis and 220-285 mm in G. auritus). Generic diagnosis of Glossocercus is emended: rostellar hooks in two rows with ten hooks of different shape and length in each, scolex large and globular, proglottides craspedote, wider than long, genital pores irregularly alternating, vagina transverse, surrounded by epithelial cells, ventral to cirrus-sac, uterus bar-shaped in mature proglottides, occupies all space between osmoregulatory ducts with eggs in gravid proglottides, ovary lobed in middle of proglottis, cirrus-sac elongate, between osmoregulatory canals, cirrus armed with spinitriches and apical tuft of slender spinitriches.
Semirings are modifications of unitary rings where the additive reduct does not form a group in general, but only a monoid. We characterize multiplicatively idempotent semirings and Boolean rings as semirings satisfying particular identities. Further, we work with varieties of enriched semirings. We show that the variety of enriched multiplicatively idempotent semirings differs from the join of the variety of enriched unitary Boolean rings and the variety of enriched bounded distributive lattices. We get a characterization of this join.
The class of pure submodules (P) and torsion-free images (R) of finite direct sums of submodules of the quotient field of an integral domain were first investigated by M. C. R. Butler for the ring of integers (1965). In this case P = R and short exact sequences of such modules are both prebalanced and precobalanced. This does not hold for integral domains in general. In this paper the notion of precobalanced sequences of modules is further investigated. It is shown that as in the case for abelian groups the exact sequence 0 → M → L → T → 0 with torsion T is precobalanced precisely when it is cobalanced and in this case will split if M is torsion-free of rank 1. It is demonstrated that containment relationships between P and R for a domain R are intimately related to the issue of when pure submodules of Butler modules are precobalanced. An analogous statement is made regarding the dual question of when torsion-free images of Butler modules are prebalanced.