Histamine metabolism and its role in central nervous system function

The present day data concerning biosynthesis, storage, release and inactivation of histamine in the brain of mammals are given. The possibility to regulate histamine of the action of physiologically active substances is discussed.     

Infrared spectra of uracil and thymine in an argon matrix

High-resolution IR spectra of uracil, thymine, methyl-derivatives of uracil and 5,6-dihydrouracil are obtained using the matrix isolation method.     

Catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria

The present catalogue of the ants (Hymenoptera, Formicidae) of Bulgaria is made on a base of critical reconsideration of literature (covering the period from 1892 till 2009 and part of 2010) as well as on examination of the authors' and several museum's collections. A lot of data were omitted in the previous Bulgarian monograph on ants, lots of new data were recently added and many important additions and alterations were made due to taxonomic revisions of Eurasian Formicidae during the last three decades. Two new species are reported for the country [Temnothorax graecus (Forel, 1911) and Temnothorax cf. korbi (Emery, 1924)].This catalogue contains a list of 163 ant species belonging to 40 genera of 6 subfamilies now known from Bulgaria. Synonyms and information on the previously reported names in relevant publications are given. Known localities of the species are grouped by geographic regions. Maps with concrete localities or regions for each species were prepared. The conservation status of 13 ant species is given as they are included in IUCN Red List of Threatened Species and Bulgarian Biodiversity Act. In comparison with adjacent Balkan regions the ant fauna of Bulgaria is quite rich and its core is composed of South European elements.     

Identification in the rat olfactory epithelium new subgroup YM-1 chitinase-like protein

Novel protein with a molecular mass of ~43 kDa from rat olfactory epithelium in pathophysiological conditions was discovered. Its amino acid sequence and affiliation with the family 18 glycohydrolase subgroup of chitinase-like proteins YM-1 were determined.     

Relationships of eelpouts of genus Zoarces (Zoarcidae, Pisces) inferred from molecular genetic and morphological data

Molecular genetic and morphological analysis of eelpouts of the genus Zoarces was carried out. Based on the mitochondrial DNA sequence variation, haplotypes of notched-fin eelpout, Z. elogatus, more closely related Fedorov eelpout, Z. fedorovi, and common eelpout, Z. viviparus, as well as of Andriyashev eelpout, Z. andriashevi, were grouped in one macrocluster. Haplotypes of American eelpout, Z. americanus, and blotched eelpout, Z. gillii, clustered separately from other species. The genetic differences between Z. gillii and the other eelpout species were very high for within-genus comparisons, constituting 7.62%. Species divergence in terms of morphological characters was generally consistent with molecular genetic data and confirmed distinct isolation of American eelpout, and especially of blotched eelpout.     

Growth and photosynthetic activity of diatom Thalassiosira weissflogii at decreasing salinity

The relative yield of variable chlorophyll fluorescence (F _v/F _m), rate of photosynthetic carbon fixation (P), growth rate, and production of extracellular photosynthates (P _ec) was studied in diatom T. weissflogii in seawater with salinity decreasing from 35 to 15 and 5‰. After incubation at 5‰ for 1 day, the diatom abundance (N) decreased as a result of death of a fraction of cells, while viable cells demonstrated decreased F _v/F _m and P, P _ec was detectable, and cell division was likely inhibited. After incubation for 2 days, population started to grow, while exponential growth rate and the abundance by day 8 were lower compared to 35‰. After incubation at 15‰ for 1 day, P was higher and F _v/F _m was lower compared to 35‰. No cell death was observed and exponential growth rate insignificantly differed from that at 5‰. The value of N by day 8 was lower compared to 35‰ but higher compared to 5‰. The dependence of photosynthetic parameters and population dynamics of T. weissflogii on the relative salinity is discussed.