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Number of results: 10
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Abstract

Results of measurements of temperature and salinity of surface waters of the Hornsund (South Spitsbergen) carried out at a coastal point of the Isbjornhamna Bay during the winter expedition 1979/80 of the Polish Academy of Sciences are discussed. Courses of both parameters, their variability, mean values and distributions are analyzed.
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Abstract

The present study aimed to evaluate the efficiency of hypertonic saline solution (HSS) as a novel treatment of acute ruminal lactic acidosis (ARLA) in cattle, focusing on urinary excretion of acids. Twelve cannulated steers were submitted to experimentally induced ARLA by adminis- tering sucrose into the rumen. Twenty hours later, the cattle were randomly divided into two equal groups. The first group was treated with 7.5% HSS (5 mL/kg) over 15 min, and isotonic saline solution (ISS; 20 mL/kg) for the subsequent 165 minutes. The control group was administered ISS instead of HSS. Rumen and urine samples were collected at different times during the experiment from the baseline to 64 h post-induction. The induction caused a medium-to-moderate ruminal acidosis, and a moderate degree of systemic acidosis and dehydration. Steers treated with HSS increased by 50% its glomerular filtration rate (1.61 mL/min) compared to ISS group (1.06 mL/ min; p<0.03). The overall volume of urine excreted by HSS group was higher than that in ISS group (1.62 L vs 0.7 L; p<0.02). This increase in total volume of urine provided by HSS favored a greater excretion of H+ ions in urine, which was 3.39-fold higher in HSS group (64.3*10-7 vs 18.9*10-7 Mol) as well as lactate (241.7 vs 181.8 mMol) and P urinary excretion (3.8 vs 1.1 mMol) that reduced the urine pH (5.3 vs 5.7). Only the HSS group decreased significantly blood total lactic acid concentration (20.3 %) throughout the treatment. A positive relationship was found between the excretion of urinary phosphorus and urinary pH (r2=0.562). The results showed that this novel treatment with HSS enhanced renal excretion of acids and may be recommended as an additional treatment for cattle with lactic acidosis.
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Abstract

Endopolyploidy is a condition of a cell containing reduplicated genetic material in its nucleus. Cells with the nuclei of different ploidy levels are often present within a single polysomatic organism. Endoreduplication is thus a modified cell cycle that omits cytokinesis and leads to chromatin replication in the endopolyploid cells. This study aimed to research the effect of salinity on endopolyploidy of Trifolium pratense and T. repens. Both species are important pasture legumes and belong to the genus Fabaceae with the well documented endopolyploidy occurence. Endopolyploidy levels in the seedlings treated with 0, 30, 60, 90 and 120 mM NaCl were investigated by flow cytometry. The seedling organs were evaluated during three ontogeny stages. The cytometric data plotted on a histogram showed the presence of 2C-16C nuclei in T. pratense and 2C-8C in T. repens. The hypothesis that salinity induces additional endocycles was not confirmed. Our results show that the distribution of nuclei among ploidy levels does not differ markedly between the treatment groups and the control ones. Additionally, only minor changes were observed among the endoreduplication indexes (EI) of plant organs after exposure to various salt concentrations. Endopolyploidy patterns within the salt-treated seedlings during ontogeny are similar to the controls. We suggest that endopolyploidy in Trifolium species is a conserved genetic trait, rather than an adaptation to salinity stress. The analyses of the roots of T'. pratense at stage III show that with the increased concentrations of NaCl the length of roots decreased, but no evident changes in endopolyploidy occured.
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Abstract

This paper presents the impact of salinisation on the aquatic mollusc fauna in flooded mine subsidences in the Karvina region (Czech Republic). The results of the previous research on salinity in flooded mine subsidences show that some of them contain a high content of dissolved inorganic substances (above 1000 mg·l-1). These substances can affect the vegetation and animals occurring in the water and the surrounding area. The phylum of Mollusca was selected as a model group for the fieldwork as it includes species with the proven bioindication potential. The occurrence of aquatic mollusc species was studied at 10 sites. The sites were selected based on the content of dissolved substances (the salinity gradient from <500 to >1000 mg·l-1. A total of 12 aquatic mollusc species were found, including one species identified as a potential bioindicator of the negative effect of salinisation on aquatic biota. The analysis showed statistically significant positive correlations between the content of dissolved inorganic substances and the presence of alien species Potamopyrgus antipodarum (J.E. Gray, 1843). The gradient of salinity significantly affects the species composition of the mollusc fauna in flooded mine subsidences and may affect the biodiversity of this group.
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Abstract

SDS-PAGE electrophoresis was used to study the effect of NaCl on protein expression in two cultivars of tomato (Solanum lycopersicum L.): Edkawi (salt-tolerant) and Castle rock (salt-sensitive). Five-day-old seedlings were grown on MS agar media supplemented with 0, 50, 100, 150, 200 and 300 mM NaCl. Two days after treatment the seedlings were examined to determine the effect of salt on their growth and to relate that to protein banding variations. Gel analysis showed differences in at least 4 protein bands with molecular weights at 20, 25, 45 and 65 kDa. These proteins were induced in the 50 mM NaCl treatment in the salt-sensitive cultivar, then decreasing to undetectability at higher concentrations. In the salt-tolerant cultivar, most of the proteins exhibited a more or less steady expression pattern and maintained expression through the 200 mM NaCl treatment. All proteins gave weak or no expression signals at 300 mM NaCl, the treatment that proved lethal. Differentially expressed bands were identified using MALDI-TOF mass spectrometry. The putative function of each identified protein in relation to salt stress is discussed.
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Abstract

A number of technologies is developed that substitute simple metal cores in the high-pressure casting technology. Soluble cores, namely on the salt basis, represent the highest prospect. The contribution gives the results of the production of salt cores by high-pressure squeezing and shooting with using a binder. Special attention is paid to the shape of NaCl salt crystals with additives and the influence on strength properties of cores. A technology of bonding the salt cores is developing. Salinity of circulating water is studied and it is checked with the aid of electrical conductance.
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