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101.
Piotr Tomasik Christopher M. Magadza Sungano Mhizha Alfred Chirume Mark. F. Zaranyika Satchmore Muchiriri 《Water, air, and soil pollution》1995,83(1-2):123-145
The toxicity against title snails of all Al, Cd, Co(II), Cr(III), Cu(II), Fe (III), Mg, Mn(II), Mo(VI), Ni(II), Pb(II), Se(VI), V(V) and Zn ions was checked in 96 h tests in the water of Kariba Lake. Based on the mortality — concentration relationship the toxicity order of the above ions against Bulinus globosus is Cu(II) > Ni(II) > Cd > Pb(II) > Zn > Al > V(V)> Cr(III)> Se(VI) > Fe(III) =Co(II)> Mn(II) > Mg > Mo(VI). Only Mg, Pb(II), Cu(II), Cd, Zn and Ni(II) ions are harmful to these snails as their mortality is observed at the naturally occuring concentrations. Other metal ions cause lethality at naturally unrealistic concentrations. The following pairs of metal ions were also checked for mutual interactions: Cd-Al, Cd-Co, Cd-Cr, Cd-Cu, Cd-Fe, Cd-Mg, Cd-Mn, Cd-Mo, Cd-Ni, Cd-Pb, Cd-Se, Cd-V, Cd-Zn, Cu-Al, Cu-Co, Cu-Cr, Cu-Fe, Cu-Mg, Cu-Mn, Cu-Mo, Cu-Ni, Cu-Pb, Cu-Se, Cu-V, Cu-Zn, Ni-Al, Ni-Co, Ni-Cr, Ni-Fe, Ni-Mg, Ni-Mn, Ni-Mo, Ni-Pb, Ni-Se, Ni-V, Ni-Zn, Pb-Al, Pb-Co, Pb-Cr, Pb-Fe, Pb-Mg, Pb-Mn, Pb-Mo, Pb-Se, Pb-V, Pb-Zn, Zn-Al, Zn-Co, Zn-Cr, Zn-Fe, Zn-Mg, Zn-Mn, Zn-Mo, Zn-Se, Zn-V. Synergism and antagonism were several times observed in various combinations of ions. The effect of metal-metal interactions on an accumulation of those metals in the flesh and shells of snails was also observed and measured. 相似文献
102.
The accumulation of Be and Ge by selected macrohydrophytes in environments polluted by industrial dust and waste products was shown to be higher than the average concentrations in unpolluted water. The Ge content of macrohydrophytes in polluted environments ranges from 7.1 to 220.4 μg g?1 and the Be content from 0.7 to 136.6 μg g?1. We have at the same time shown the relationships between Be and Ge in water and plants. The accumulation of Be and Ge in plants is conditioned by the amount of N and K in water, hydrosol and in the plants themselves. Our experiments show growth disturbances in macrohydrophytes containing high concentration of Be and Ge. 相似文献
103.
Wiesław Barabasz Bogusława Hetmańska Piotr Tomasik 《Water, air, and soil pollution》1990,52(3-4):337-357
The effect of nine metal ions: Co(II), Cr(III), Mg, Ni(II), Pb(II), Se(IV), Ti(III), V(IV) and Zn and following pairs of them: Cr-Mg, Cr-Se, Cr-Co, Cr-Zn, Cr-Ni, Ni-Mg, Ni-Se, Ni-Co, Ni-Zn, Pb-Mg, Pb-Se, Pb-Co, Pb-Zn, Ti-Mg, Ti-Se, Ti-Co, Ti-Zn, V-Mg, V-Se, V-Co and V-Zn was tested on the growth of Escherichia coli. Each test lasted 4 days. Magnesium is the most potent protective agent in all pairs of metals. The observed effects are not dependent only on concentration but also on time. 相似文献
104.
Droplets of one liquid suspended in a second, immiscible liquid move through a microfluidic device in which a channel splits into two branches that reconnect downstream. The droplets choose a path based on the number of droplets that occupy each branch. The interaction among droplets in the channels results in complex sequences of path selection. The linearity of the flow through the microchannels, however, ensures that the behavior of the system can be reversed. This reversibility makes it possible to encrypt and decrypt signals coded in the intervals between droplets. The encoding/decoding device is a functional microfluidic system that requires droplets to navigate a network in a precise manner without the use of valves, switches, or other means of external control. 相似文献
105.
Zdanowicz Marta Mudryk Zbigniew Jan Perliński Piotr 《Veterinary research communications》2020,44(1):9-18
Veterinary Research Communications - Abundance and antibiotic resistance of bacteria of the genus Aeromonas isolated from the water of three carp ponds were studied. The number of those bacteria... 相似文献
106.
107.
Katarzyna Andraszek Dorota Banaszewska Olga Szeleszczuk Piotr Niedbała Marta Kuchta-Gładysz 《Reproduction in domestic animals》2020,55(4):515-522
Sperm cells isolated from the tail of the epididymis and from the semen of the same individuals were analysed. The use of silver nitrate to stain sperm cells isolated from the tail of the epididymis made it possible to identify structures that were not visible in the sperm from semen. Silver nitrate very clearly distinguished the acrosomal and distal parts of the sperm head. Following silver nitrate staining, the sperm isolated from the tail of the epididymis were characterized by dark ‘collars’ in the distal part of the head. These ‘collars’ are not visible in the sperm cells isolated from semen. The results of the study indicate differences in the dimensions of sperm isolated from the tail of the epididymis and sperm in semen. Sperm isolated from the tail of the epididymis had smaller heads, despite their longer length, and had longer midpieces and tails than ejaculate sperm. Silver nitrate staining is a simple and fast technique. Silver nitrate makes it possible to identify the acrosome and post-acrosomal region of the sperm head and to clearly identify the midpiece. Therefore, it can be successfully used to supplement routine techniques for evaluating sperm morphology or as an independent technique. 相似文献
108.
Piotr Brodzki Urszula Lisiecka Adam Brodzki Leszek Krakowski Marek Szczubia Roman Dbrowski Andrzej Junkuszew Mariola Bochniarz 《Animal Science Journal》2020,91(1)
The aim of the study was to evaluate the selected lymphocyte subpopulations TCD4, TCD8, BCD21, BCD25, CD18, CD11b, and MHC II in blood and uterine flush of cows with endometritis, before and after intrauterine (i.u.) administration of cefapirin and methisoprinol. The research was carried out on 28 cows with clinical endometritis. Animals were divided into four groups, each composed of seven cows, depending on the i.u. preparation used: Group A, cefapirin; Group B, methisoprinol; Group C, cefapirin and methisoprinol simultaneously; and a control group—without medication. The study was performed using flow cytometry method. Summarizing the results of the research, i.u. infusion of cefapirin caused a weakening of the effector phase of the local uterine immune response; however, it enhanced leukocyte chemotaxis and antigen presentation. After i.u. administration of methisoprinol, the stimulation of specific uterine immunity mechanisms was mainly observed. The use of both mentioned preparations showed the strengthening of specific uterine immunological mechanisms presumably caused by methisoprinol, despite the inhibitory effect of the antibiotic. Intrauterine use of immunostimulatory substances can improve the effectiveness of the endometritis treatment in cows by improving specific local mechanisms of uterine immunity. As a consequence, it may enhance the effector function of immune competent cells and finally eliminate inflammation. 相似文献
109.
Piotr Nowicki Vladimir Vrabec Birgit Binzenhöfer Johann Feil Barbara Zakšek Thomas Hovestadt Josef Settele 《Landscape Ecology》2014,29(3):401-412
Metapopulation models typically assume that suitable habitats occupied by local populations and unsuitable matrix separating them form a ‘black-and-white’ landscape mosaic, in which dispersal is primarily determined by the spatial configuration of habitat patches. In reality, however, the matrix composition is also likely to influence dispersal. Using intensive mark-recapture surveys we investigated inter-patch movements in Maculinea (Phengaris) nausithous and M. teleius occurring sympatrically in six metapopulations. Three of these metapopulations had the matrix dominated by forest, an inhospitable environment for grassland butterflies, whereas in the remaining three the matrix was mostly composed of open environments. Dispersal parameters derived with the Virtual Migration model revealed significant differences between both groups of metapopulations. Both species had a lower propensity to emigrate from their natal habitat patches, and they suffered substantially higher dispersal mortality in the metapopulations with forest matrix. On the other hand, mean dispersal distances were roughly an order of magnitude longer in forest matrix as compared with open landscapes (ca. 500–1,500 vs. 100–200 m). Our results suggest that inhospitable forest matrix induces strong selection against dispersal, leading to a reduced emigration rate. At the same time, the selection may promote emigrants with good dispersal abilities, which are able to perform long-distance movements. Thus, while it is generally believed that a matrix structurally similar to the habitat of a species should improve the functional connectivity of habitat patches, our findings imply that this may not necessarily be the case. 相似文献
110.
Felska-Błaszczyk L Lasota B Sulik M Masłowska A Dziadosz M Błaszczyk B Błaszczyk P 《The Journal of reproduction and development》2011,57(3):416-420
The aim of this study was to determine whether blood plasma progesterone is a reliable indicator of pregnancy in mink at an early stage of gestation. We also attempted to establish the threshold value of progesterone as a pregnancy indicator. The analysis was carried out at a production farm on 42 standard female mink aged 1 year, which were grouped both according to the observed success of mating ("mated" and "unmated") and the level of blood serum progesterone measured afterwards ("pregnant" and "nonpregnant"). It was next verified whether a particular female had been assigned to the proper group in the first place. An analysis of accuracy of mating success assessment within the group of unmated females revealed that more than one-third of decisions were wrong, since some females that had been considered unmated ultimately whelped. This suggests that mating supervision by farm workers lacks reliability. A progesterone test for verification of such management decisions should limit the risk of err,or. We suggest that progesterone tests could be carried out using the threshold values 1.9 ng/ml and 20 ng/ml in blood sampled on 25 March and 8 April, respectively, although some level of uncertainty should be taken into account. 相似文献