Electrophoretic characteristics of ram and rabbit spermatozoa

1961 ◽  
Vol 155 (959) ◽  
pp. 292-305 ◽  
Keyword(s):  
Electric Field ◽  
Swimming Speed ◽  
Salt Concentration ◽  
High Salt ◽  
Ion Concentration ◽  
Ground Speed ◽  
Constant Ph ◽  
Electrophoretic Velocity ◽  
Low Ionic Strength ◽  
Rabbit Spermatozoa

1. The influence of a d. c. electric field on the direction in which ram and rabbit spermatozoa swim has been investigated. The magnitude of the electrophoretic component is so small in the presence of high salt concentrations ( μ = 0.1) that it plays no part in controlling the direction in which the spermatozoa swim. A significant electrophoretic velocity component can, however, be imposed if the spermatozoa are suspended in a diluent (277 mM-fructose) with a low ionic strength ( μ < 0.01). In this condition higher field strengths can be applied without any concomitant rise in temperature, and the ζ-potential increases because the gegen-ion concentration is reduced. 2. In a diluent containing 277 mM-fructose and 10 mM-NaCl two types of spermatozoa are seen when the electric field is applied. Their orientation depends on whether they carry a net negative charge in the region of their heads or their tails. 'Head-anode' spermatozoa swim with unusual rapidity towards the anode but immediately decelerate when the field is switched off. ‘Tail-anode' spermatozoa have a variable ground speed and may, if the field strength is high, be seen swimming tail first towards the anode. They accelerate away from the anode when the field is switched off. 3. The proportions of the two types of spermatozoa vary with salt concentration at constant pH, and with pH at constant salt (10 mM-NaCl) concentration. 4. If the swimming speed of spermatozoa is reduced by cooling, electrophoresis in the presence of high salt concentration ( μ = 0.1) differentiates spermatozoa into two kinds in another way. Both are oriented with their tails pointing towards the anode (tail-anode), but their net ground speed may vary in magnitude and direction according to their inherent swimming speed. Complete immobilization of the spermatozoa resulted in a uniform electrophoretic migration towards the anode, tail first, at all pH’s above 3.5. 5. The implications of these findings are discussed with respect to sperm phenotypes and their possible electrophoretic separation.

Sand priming improves alfalfa germination under high-salt concentration stress

2006 ◽  
Vol 34 (1) ◽  
pp. 199-204 ◽  
Author(s):  
J. Hu ◽  
X.J. Xie ◽  
Z.F. Wang ◽  
W.J. Song
Keyword(s):  
Salt Concentration ◽  
High Salt ◽  
High Salt Concentration

Effect of Salt Concentration and Incubation Temperature on Formation of Histamine, Phenethylamine, Tryptamine and Tyramine During Miso Fermentation

1986 ◽  
Vol 49 (6) ◽  
pp. 423-427 ◽  
Author(s):  
K.-D. HENRY CHIN ◽  
P. E. KOEHLER
Keyword(s):  
Salt Concentration ◽  
Incubation Temperature ◽  
High Salt ◽  
Soybean Paste ◽  
Salt Level ◽  
Low Salt ◽  
Two Factors

Two factors, salt concentration and incubation temperature, were examined for their effect on the formation of histamine, phenethylamine, tryptamine and tyramine during miso (soybean paste) fermentation. Misos containing 5 and 10% NaCl were prepared and incubated at 25 and 35°C. The effect of each factor was determined from the chemical and microbiological changes in the misos during fermentation. Salt level was a significant factor in the formation of amines. Higher amine levels were found in low-salt (5% NaCl) formulations than in high-salt (10% NaCl) misos. Incubation temperature within the range of 25 to 35°C during fermentation had little effect on amine formation in misos.

scholarly journals A numerical model of the ionosphere, including the E-region above EISCAT

1996 ◽  
Vol 14 (2) ◽  
pp. 191-200 ◽  
Author(s):  
P.-Y. Diloy ◽  
A. Robineau ◽  
J. Lilensten ◽  
P.-L. Blelly ◽  
J. Fontanari
Keyword(s):  
Electric Field ◽  
Fluid Model ◽  
Molecular Ions ◽  
Ion Concentration ◽  
Topside Ionosphere ◽  
Ion Chemistry ◽  
Vhf Radar ◽  
Theoretical Predictions ◽  
Consistent Manner ◽  
E Region

Abstract. It has been previously demonstrated that a two-ion (O+ and H+) 8-moment time-dependent fluid model was able to reproduce correctly the ionospheric structure in the altitude range probed by the EISCAT-VHF radar. In the present study, the model is extended down to the E-region where molecular ion chemistry (NO+ and O+2, essentially) prevails over transport; EISCAT-UHF observations confirmed previous theoretical predictions that during events of intense E×B induced convection drifts, molecular ions (mainly NO+) predominate over O+ ions up to altitudes of 300 km. In addition to this extension of the model down to the E-region, the ionization and heating resulting from both solar insolation and particle precipitation is now taken into account in a consistent manner through a complete kinetic transport code. The effects of E×B induced convection drifts on the E- and F-region are presented: the balance between O+ and NO+ ions is drastically affected; the electric field acts to deplete the O+ ion concentration. The [NO+]/[O+] transition altitude varies from 190 km to 320 km as the perpendicular electric field increases from 0 to 100 mV m-1. An interesting additional by-product of the model is that it also predicts the presence of a noticeable fraction of N+ ions in the topside ionosphere in good agreement with Retarding Ion Mass Spectrometer measurements onboard Dynamic Explorer.

Full-Scale MBR Operating Experience for the Treatment of high Salt Concentration Wastewater from Carrageenan Production

2014 ◽  
Vol 2014 (13) ◽  
pp. 5362-5373
Author(s):  
Joseph Lala ◽  
Renato Lebumfacil ◽  
Ed Mira ◽  
Shannon R. Grant ◽  
Scott J. Christian ◽  
...  
Keyword(s):  
Salt Concentration ◽  
Operating Experience ◽  
Full Scale ◽  
High Salt ◽  
High Salt Concentration

scholarly journals Release of poly a(+) messenger RNA from rat liver rough microsomes upon disassembly of bound polysomes

1977 ◽  
Vol 74 (2) ◽  
pp. 414-427 ◽  
Author(s):  
J Kruppa ◽  
DD Sabatini
Keyword(s):  
Ionic Strength ◽  
Rat Liver ◽  
Messenger Rna ◽  
High Salt ◽  
Salt Medium ◽  
Ribosomal Subunits ◽  
Microsomal Membranes ◽  
Low Ionic Strength

Several procedures were used to disassemble rat liver rough microsomes (RM) into ribosomal subunits, mRNA, and ribosome-stripped membrane vesicles in order to examine the nature of the association between the mRNA of bound polysomes and the microsomal membranes. The fate of the mRNA molecules after ribosome release was determined by measuring the amount of pulse-labeled microsomal RNA in each fraction which was retained by oligo-dT cellulose or by measuring the poly A content by hybridization to radioactive poly U. It was found that ribosomal subunits and mRNA were simultaneously released from the microsomal membranes when the ribosomes were detached by: (a) treatment with puromycin in a high salt medium containing Mg++, (b) resuspension in a high salt medium lacking Mg++, and (c) chelation of Mg++ by EDTA or pyrophosphate. Poly A-containing mRNA fragments were extensively released from RM subjected to a mild treatment with pancreatic RNase in a medium of low ionic strength. This indicates that the 3' end of the mRNA is exposed on the outer microsomal surface and is not directly bound to the membranes. Poly A segments of bound mRNA were also accessible to [(3)H] poly U for in situ hybridization in glutaraldehyde-fixed RM. Rats were treated with drugs which inhibit translation after formation of the first peptide bonds or interfere with the initiation of protein synthesis. After these treatments inactive monomeric ribosomes, as well as ribosomes bearing mRNA, remained associated with their binding sites in microsomes prepared in media of low ionic strength. However, because there were no linkages provided by nascent chains, ribosomes, and mRNA, molecules were released from the microsomal membranes without the need of puromycin, by treatment with a high salt buffer containing Mg++. Thus, both in vivo and in vitro observations are consistent with a model in which mRNA does not contribute significantly to the maintenance of the interaction between bound polysomes and endoplasmic reticulum membranes in rat liver hepatocytes.

scholarly journals Leakage Current Degradation Due to Ion Drift and Diffusion in Tantalum and Niobium Oxide Capacitors

2017 ◽  
Vol 24 (2) ◽  
pp. 255-264 ◽  
Author(s):  
Martin Kuparowitz ◽  
Vlasta Sedlakova ◽  
Lubomir Grmela
Keyword(s):  
High Temperature ◽  
Electric Field ◽  
Leakage Current ◽  
Niobium Oxide ◽  
Ion Concentration ◽  
Homogeneous Distribution ◽  
Insulating Layer ◽  
Ion Drift ◽  
Positive Ions ◽  
And Diffusion

AbstractHigh temperature and high electric field applications in tantalum and niobium capacitors are limited by the mechanism of ion migration and field crystallization in a tantalum or niobium pentoxide insulating layer. The study of leakage current (DCL) variation in time as a result of increasing temperature and electric field might provide information about the physical mechanism of degradation. The experiments were performed on tantalum and niobium oxide capacitors at temperatures of about 125°C and applied voltages ranging up to rated voltages of 35 V and 16 V for tantalum and niobium oxide capacitors, respectively. Homogeneous distribution of oxygen vacancies acting as positive ions within the pentoxide layer was assumed before the experiments. DCL vs. time characteristics at a fixed temperature have several phases. At the beginning of ageing the DCL increases exponentially with time. In this period ions in the insulating layer are being moved in the electric field by drift only. Due to that the concentration of ions near the cathode increases producing a positively charged region near the cathode. The electric field near the cathode increases and the potential barrier between the cathode and insulating layer decreases which results in increasing DCL. However, redistribution of positive ions in the insulator layer leads to creation of a ion concentration gradient which results in a gradual increase of the ion diffusion current in the direction opposite to the ion drift current component. The equilibrium between the two for a given temperature and electric field results in saturation of the leakage current value. DCL vs. time characteristics are described by the exponential stretched law. We found that during the initial part of ageing an exponent n = 1 applies. That corresponds to the ion drift motion only. After long-time application of the electric field at a high temperature the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5. Here, the equilibrium between the ion drift and diffusion is achieved. The process of leakage current degradation is therefore partially reversible. When the external electric field is lowered, or the samples are shortened, the leakage current for a given voltage decreases with time and the DCL vs. time characteristics are described by the exponential stretched law with an exponent n = 0.5, thus the ion redistribution by diffusion becomes dominant.

scholarly journals Efficient conjugal transfer of inc R-plasmids at high salt concentration in the mating media.

1988 ◽  
Vol 54 (5) ◽  
pp. 845-849 ◽  
Author(s):  
Fujio Hayashi ◽  
Yasuhisa Araki ◽  
Matsuhisa Inoue ◽  
Hajime Hashimoto
Keyword(s):  
Salt Concentration ◽  
High Salt ◽  
Conjugal Transfer ◽  
High Salt Concentration ◽  
R Plasmids
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