Age and growth of kaluga Acipenser dauricus from the estuary of the Amur and its lagoon

Age composition and the rate of growth of kaluga Acipenser dauricus from the estuary of the Amur and the Amur lagoon have been analyzed. Differences in the distribution of juvenile and mature individuals of kaluga in the river estuary and the lagoon were revealed. Males are dominant among mature individuals aged 18–26 years, and females are dominanat at an age 27–43 years. Females and males of the same age do not differ in length and body weight. A decrease in the rate of linear and gravimetric growth of mature individuals at the modern stage (2005–2008) compared to the period of 1965–1982 was revealed. Juvenile individuals of kaluga from the near-estuarine part of the Amur and its lagoon are inferior in the rate of growth to fish of the same age caught in the river channel, 500 km to the south.     

Trilobites Plicatolina lucida Lazarenko from the Upper Cambrian of the Kharaulakh Mountains (Northeastern Siberian Platform)

A collection of trilobites of the genus Plicatolina Shaw, 1951 from the upper Ogon’or Formation, Cambrian Section, Chekurovka Anticline (northeastern Siberian Platform, Kharaulakh Mountains), is studied. It is shown that all specimens of this collection belong to the same species, Plicatolina lucida Lazarenko, 1966, but represent different age stages. It is also shown that species of the genus Plicatolina (P. quadrata Pokrovskaya, 1966 and P. yakutica Pokrovskaya, 1966) described from the Upper Cambrian of the Siberian Platform are probably synonyms of P. lucida.     

Lowland river reference condition: spatial and temporal patterns of the zoobenthos community in the Volga headwaters (2006–2010)

The Volga, the largest river in Europe, has experienced multiple stressors from human activities. Recently we showed that its upper course (about 500 km, from its source to Tver) still has large sections with low impact and a natural type-specific potamal flora and fauna. Our present research in the East European lowlands aim to define reference conditions for mid-sized to large lowland rivers in order to build a basis for future management and conservation. Three monitoring sites were selected based on the results from intensive sampling in 2005. In subsequent field campaigns between 2006 and 2010 regular surveys were carried out each year in summer and additional ones in spring. A taxon-rich macroinvertebrate fauna, including several rare potamal relict species, was recorded and the data was used to provide an overview of annual and interannual variation in community indices and metrics. The conditions described for the headwaters of the Volga River system can be used as a reference state for medium-sized and large lowland rivers in regions where reference sites of these types are lacking.     

Wavelet-synchrony of Brain Evoked Responses during Listening to Naturalistic Stimuli in the Prognosis of Consciousness Recovery (Study 1: Wavelet-synchrony during Listening to Instrumental Music)

The features and prognostic value of wavelet-synchrony of evoked responses during the listening to realistic stimuli (music) were revealed in the study. Musical passages were selected according the patients’ preferences by their relations consultation. Wavelet-connections were calculated for each melody in the range from 0 to 1000 ms from stimuli. Total 22 examinees in 12 patients being in unconsciousness state were carried out. Resting state values of wavelet-connectivity were poorer in vegetative patients in comparison to healthy subjects regardless of consciousness recovery degree in future while wavelet-connections in mutism were higher in comparison to healthy subjects. Absolute value of wavelet-synchrony was lower than in norm. In patients with compete consciousness recovery in the future the maximal values of wavelet-synchrony were revealed in the temporal-occipital area while in patients who in the future have been revealed in the lesser degree the maximal values of wavelet-synchrony are shown in frontal-central areas. In chronic unconsciousness patients during the listening to instrumental music the maximal wavelet-connections values were determined in the right frontal area.     

Effect ofKluyveromyces marxianus on the growth and survival of bifidobacteria in milk

Four strains of bifidobacteria (B. bifidum 93,B. infantis ATCC 17 930,B. longum ATCC 15 707, andB. longum JR) cultivated in MRS broth modified by the addition of cysteine-hydrochloride (0.05 %) were serially subcultured in unsupplemented cow milk alone or in combination withKluyveromyces marxianus var.marxianus 269 under aerobic conditions. In monoculture, bifidobacteria did not multiply after the second subculture. In contrast, in coculture with yeast bifidobacteria reached counts about 8 log CFU/g even during 15 subcultures. In addition,K. marxianus var.marxianus 269 significantly prolonged the survival of bifidobacteria in milk at 4 °C. The most susceptible strains (B. longum Jr andB. infantis ATCC 17 930) completely lost their viability within 5 and 12 d of storage, respectively, while in coculture with yeasts all bifidobacteria cultures tested survived for at least 40 d. The results could be useful in producing kefir-like fermented milks containing bifidobacteria. The study was supported by grant no. 238/10/12596/0 of theInternal Grant Agency of Czech University of Agriculture ion Prague.     

Biochemical mechanisms of resistance to a new antineoplastic drug CRC 680578 from the nitrosourea class]

The biochemical mechanisms of resistance to CRC 680578, a new antitumour chloroethylnitrosourea alpha-amino acid derivative, were studied. Alterations in DNA, RNA and protein syntheses, SH-group content, drug efflux, activities of replicative and repair enzymes, such as ribonucleotide reductase, thymidine kinase, O6-alkylguanine-DNA-alkyltransferase and DNA polymerases alpha and beta and damages of the DNA secondary structure were investigated in sensitive and resistant to CRC 680578 leukemia L1210 cells. It was found that the total SH-group number in drug-resistant cells was increased (about 1.3-fold in comparison with sensitive cells) which seems to be due to the mechanisms of drug resistance. CHC 680578 induced less pronounced inhibition and more rapid restoration of DNA and RNA synthesis in resistant cells. No differences between the ribonucleotide reductase and thymidine kinase activities were found either in intact cells of the both strains or after drug administration. The efficiency of repair of DNA chloroethyl adducts by O6-alkylguanine-DNA-alkyltransferase in leukemia cells of various sensitivity was found to be identical. The differences in enzyme activities in intact cells of the both strains were insignificant. It was supposed that factors other than changes in the level of O6-alkylguanine-DNA-alkyltransferase in leukemia cells may be responsible for the resistance to CRC 680578. The increase in the levels of DNA polymerase alpha and, especially, of DNA polymerase beta, in sensitive (but not resistant) mouse leukemia cells 48 hours after drug administration is though to define the mechanism of resistance to the new antitumour agent CHC 680578.