scholarly journals ELECTRIC IMPEDANCE OF ASTERIAS EGGS

1936 ◽  
Vol 19 (4) ◽  
pp. 609-623 ◽  
Author(s):  
Kenneth S. Cole ◽  
Robert H. Cole
Keyword(s):  
Plasma Membrane ◽  
Sea Water ◽  
Specific Resistance ◽  
Surface Conductance ◽  
Electric Impedance ◽  
High Concentration ◽  
Low Frequencies ◽  
Definite Evidence ◽  
Asterias Forbesi ◽  
Current Resistance

The alternating current resistance and capacity of suspensions of unfertilized eggs of Asterias forbesi have been measured at frequencies from one thousand to sixteen million cycles per second. The plasma membrane of the egg has a static capacity of 1.10µf/cm.2 which is practically independent of frequency. The suspensions show a capacity dependent on frequency at low frequencies which may be attributable to surface conductance. The specific resistance of the cytoplasm is between 136 and 225 ohm cm. (4 to 7 times sea water), indicating a relatively high concentration of non-electrolytes. At frequencies above one million cycles there is definite evidence of another element of which the nucleus is presumably a part.

scholarly journals ELECTRIC IMPEDANCE OF ARBACIA EGGS

1936 ◽  
Vol 19 (4) ◽  
pp. 625-632 ◽  
Author(s):  
Kenneth S. Cole ◽  
Robert H. Cole
Keyword(s):  
Plasma Membrane ◽  
Sea Water ◽  
Low Frequency ◽  
Relaxation Dispersion ◽  
Surface Conductance ◽  
Low Frequencies ◽  
Membrane Capacity ◽  
A Value ◽  
Fertilization Membrane ◽  
Fertilized Egg

The alternating current resistance and capacity of suspensions of unfertilized and fertilized eggs of Arbacia punctulata have been measured at frequencies from 103 to 1.64 x 107 cycles per second. The unfertilized egg has a static plasma membrane capacity of 0.73 µf./cm.2 which is practically independent of frequency. The fertilized egg has a static membrane capacity of 3.1 µf./cm.2 at low frequencies which decreases to a value of 0.55 µf./cm.2 at high frequencies. The decrease follows closely the relaxation dispersion of the dielectric constant if the dissipation of such a system is ignored. It is considered more probable that the effect is due to a fertilization membrane of 3.1 µf./cm.2 capacity lifted 1.5 µ. from the plasma membrane, the interspace having the conductivity of sea water. The suspensions show a frequency-dependent capacity at low frequencies which may be attributable to surface conductance. The equivalent low frequency internal specific resistance of both the unfertilized and fertilized egg is about 186 ohm cm. or about 6 times that of sea water, while the high frequency data extrapolate to a value of about 4 times sea water. There is evidence at the highest frequencies that the current is penetrating the nucleus and other materials in the cytoplasm. If this effect were entirely due to the nucleus it would lead to a very approximate value of 0.1 µf./cm.2 for the capacity of the nuclear membrane. The measurements do not indicate any change in this effect on fertilization.

scholarly journals ELECTRIC IMPEDANCE OF HIPPONOË EGGS

1935 ◽  
Vol 18 (6) ◽  
pp. 877-887 ◽  
Author(s):  
Kenneth S. Cole
Keyword(s):  
Volume Concentration ◽  
Marked Effect ◽  
Sea Water ◽  
Unit Area ◽  
Specific Resistance ◽  
Internal Resistance ◽  
Simple Method ◽  
Low Frequencies ◽  
Static Capacity ◽  
Current Resistance

Alternating current resistance and capacity measurements have been made from 1.08 103 to 2.32 106 cycles per second on suspensions of unfertilized, fertilized, and swollen unfertilized eggs of the echinoderm Hipponoë esculenta. A simple method has been developed for measuring the volume concentration of eggs in a suspension. The membrane of the unfertilized egg is practically non-conducting at low frequencies and shows a static capacity of 0.87 µf/cm.2 except perhaps at the highest frequencies. The equivalent specific resistance of the egg interior is 11 times that of sea water. The membrane of the fertilized egg is practically non-conducting at low frequencies and shows a static capacity 2.5 times that of the unfertilized egg except at the higher frequencies where another reactive element produces a marked effect. The internal resistance is apparently higher than that of the unfertilized egg. The static capacity per unit area of the membrane decreases as a linear function of the surface area when the eggs are swollen in dilute sea water. In 40 per cent sea water, the capacity falls to about 75 per cent of normal.

scholarly journals ELECTRIC IMPEDANCE OF FERTILIZED ARBACIA EGG SUSPENSIONS

1938 ◽  
Vol 21 (5) ◽  
pp. 583-590 ◽  
Author(s):  
Kenneth S. Cole ◽  
Joseph M. Spencer
Keyword(s):  
Plasma Membrane ◽  
High Resistance ◽  
Sea Water ◽  
High Capacity ◽  
Low Frequency ◽  
Alternating Current ◽  
Electric Impedance ◽  
Perivitelline Space ◽  
Membrane Capacity ◽  
Fertilization Membrane

From the low frequency alternating current impedance and the volume concentrations of suspensions of Arbacia eggs, it is shown that the high resistance membrane is either at or very near the plasma membrane for both unfertilized and fertilized eggs, and that the specific resistances of the perivitelline space and fertilization membrane are not greatly different from that of sea water. The effect of the capacity element which appears after fertilization at intermediate frequencies is considerably less than in the earlier experiments on Arbacia and Hipponoë eggs. These findings indicate that the fertilization membrane does not have the high capacity previously attributed to it and that the increase in membrane capacity takes place at or near the plasma membrane.

scholarly journals ELECTRIC IMPEDANCE OF SUSPENSIONS OF ARBACIA EGGS

1928 ◽  
Vol 12 (1) ◽  
pp. 37-54 ◽  
Author(s):  
Kenneth S. Cole
Keyword(s):  
Cell Division ◽  
Surface Impedance ◽  
Sea Water ◽  
Specific Resistance ◽  
Electric Impedance ◽  
Membrane Formation ◽  
Specific Change ◽  
Polarization Capacity

Apparatus has been designed and constructed for the measurement of the electric impedance of suspensions of Arbacia eggs in sea water to alternating currents of frequencies from one thousand to fifteen million cycles per second. This apparatus is simple, rugged, compact, accurate, and rapid. The data lead to the conclusions that the specific resistance of the interior of the egg is about 90 ohm cm. or 3.6 times that of sea water, and that the impedance of the surface of the egg is probably similar to that of a "polarization capacity". The characteristics of this surface impedance can best be determined by measurements of the capacity and resistance of suspensions of eggs. No specific change has been found in the interior resistance or the surface impedance which can be related either to membrane formation or to cell division.

scholarly journals TRANSVERSE ELECTRIC IMPEDANCE OF THE SQUID GIANT AXON

1938 ◽  
Vol 21 (6) ◽  
pp. 757-765 ◽  
Author(s):  
Howard J. Curtis ◽  
Kenneth S. Cole
Keyword(s):  
Current Flow ◽  
Transverse Electric ◽  
Sea Water ◽  
Specific Resistance ◽  
Giant Axon ◽  
Simple Analysis ◽  
Axon Membrane ◽  
Polarization Impedance ◽  
Direct Current Resistance ◽  
Current Resistance

The impedance of the excised giant axon from hindmost stellar nerve of Loligo pealii has been measured over the frequency range from 1 to 2500 kilocycles per second. The measurements have been made with the current flow perpendicular to the axis of the axon to permit a relatively simple analysis of the data. It has been found that the axon membrane has a polarization impedance with an average phase angle of 76° and an average capacity of 1.1µf./cm2 at 1 kilocycle. The direct current resistance of the membrane could not be measured, but was greater than 3 ohm cm.2 and the average internal specific resistance was four times that of sea water. There was no detectable change in the membrane impedance when the axon lost excitability, but some time later it decreased to zero.

scholarly journals ELECTRIC IMPEDANCE OF THE FROG EGG

1942 ◽  
Vol 25 (5) ◽  
pp. 765-775 ◽  
Author(s):  
Kenneth S. Cole ◽  
Rita M. Guttman
Keyword(s):  
Plasma Membrane ◽  
Electrical Impedance ◽  
Rana Pipiens ◽  
Specific Resistance ◽  
Membrane Resistance ◽  
Leopard Frog ◽  
Electric Impedance ◽  
Frequency Range ◽  
Impedance Measurements ◽  
Membrane Capacity

Electrical impedance measurements were made upon unfertilized and fertilized eggs of the leopard frog, Rana pipiens, over a frequency range of 0.05 to 10 kc. Average values of 170 ohm cm.2 were obtained for the plasma membrane resistance of the egg, 2.0 µf/cm.2 for the plasma membrane capacity, 86° for the phase angle of the membrane, and 570 ohm cm. for the specific resistance of the interior. These values did not change upon fertilization. No spontaneous rhythmical impedance changes such as have been found by Hubbard and Rothschild in the trout egg were found in frog eggs.

MEASURES FOR ENVIRONMENT CONSERVATION IN ENCLOSED COASTAL SEAS

2017 ◽  
Author(s):  
Keizo Negi ◽  
Keizo Negi ◽  
Takuya Ishikawa ◽  
Takuya Ishikawa ◽  
Kenichiro Iba ◽  
...  
Keyword(s):  
Water Pollution ◽  
Water Quality ◽  
Water Mass ◽  
Sea Water ◽  
Red Tide ◽  
Water Environment ◽  
Quality Standard ◽  
Tokyo Bay ◽  
View Point ◽  
High Concentration

Japan experienced serious water pollution during the period of high economic growth in 1960s. It was also the period that we had such damages to human health, fishery and living conditions due to red tide as much of chemicals, organic materials and the like flowing into the seas along the growing population and industries in the coastal areas. Notable in those days was the issues of environment conservation in the enclosed coastal seas where pollutants were prone to accumulate inside due to low level of water circulation, resulting in the issues including red tide and oxygen-deficient water mass. In responding to these issues, we implemented countermeasures like effluent control with the Water Pollution Control Law and improvement/expansion of sewage facilities. In the extensive enclosed coastal seas of Tokyo Bay, Ise Bay and the Seto Inland Sea, the three areas of high concentration of population, we implemented water quality total reduction in seven terms from 1979, reducing the total quantities of pollutant load of COD, TN and TP. Sea water quality hence has been on an improvement trend as a whole along the steady reduction of pollutants from the land. We however recognize that there are differences in improvement by sea area such as red tide and oxygen-deficient water mass continue to occur in some areas. Meanwhile, it has been pointed out that bio-diversity and bio-productivity should be secured through conservation/creation of tidal flats and seaweed beds in the view point of “Bountiful Sea” To work at these challenges, through the studies depending on the circumstances of the water environment in the enclosed coastal seas, we composed “The Policy of Desirable State of 8th TPLCS” in 2015. We have also added the sediment DO into the water quality standard related to the life-environmental items in view of the preservation of aquatic creatures in the enclosed water areas. Important from now on, along the Policy, is to proceed with necessary measures to improve water quality with good considerations of differences by area in the view point of “Beautiful and bountiful Sea”.

High concentration of plasma membrane H+-ATPase in root caps ofLepidium sativum L.

1993 ◽  
Vol 80 (7) ◽  
pp. 317-319 ◽  
Author(s):  
H. -G. Stenz ◽  
H. -G. Heumann ◽  
M. H. Weisenseel
Keyword(s):  
Plasma Membrane ◽  
High Concentration

Propagation of electrical signals along giant nerve fibres

1952 ◽  
Vol 140 (899) ◽  
pp. 177-183 ◽  
Keyword(s):  
Sea Water ◽  
Giant Axon ◽  
High Concentration ◽  
Nerve Fibres ◽  
Giant Fibre ◽  
Electrical Signals ◽  
Small Fibre ◽  
The Central Nervous System ◽  
Good Conductor ◽  
Ionic Movement

In this part of the discussion we shall attempt to describe the way in which electrical signals are propagated along the giant nerve fibres of squids and cuttlefish. These fibres consist of cylinders of protoplasm, 0.2 to 0.6 mm in diameter, and ire bounded by a thin membrane which acts as a barrier to ionic movement. The protoplasm, or axoplasm as it is commonly called, is an aqueous gel which is a reasonably good conductor of electricity. It contains a high concentration of K + and a low concentration of Na + and Cl - , this situation being the reverse of that in the animal’s blood or sea water. Axons which are left in sea water slowly lose potassium and gain sodium. This process takes about 24 hours and is roughly 80 000 times slower than the diffusion of ions out of a cylinder of gelatin of the same size. The interchange of sodium and potassium is very greatly accelerated by stimulating the fibres. Experiments with tracers, such as those made by Keynes & Lewis (1951) or Rothenberg (1950), allow the interchange to be measured quantitatively, and there is general agreement that the impulse is associated with an entry of 3 to 4 µ µ mol of Na + through 1 cm 2 of membrane and an exit of a corresponding quantity of K + . These quantities are very small compared with the total number of ions inside the fibre. In the giant axon of the squid the quantity of potassium lost in each impulse corresponds to only about 1 millionth if the total internal potassium. One would therefore expect that a giant fibre should be able to carry a great many impulses without recharging its batteries by metabolism. On the other hand, a very small fibre such as a dendrite in the central nervous system should be much more dependent on metabolism since the ratio of surface to volume may be nearly 1000 times greater.

Motility and energy-rich phosphorus compounds in spermatozoa of Octopus dofleini martini

1971 ◽  
Vol 178 (1051) ◽  
pp. 151-160 ◽  
Keyword(s):  
Sea Water ◽  
Phosphorus Compounds ◽  
Short Exposure ◽  
Motile Sperm ◽  
High Concentration ◽  
Irreversible Loss ◽  
Prolonged Incubation ◽  
The North ◽  
Sperm Suspension ◽  
The North Pacific

The spermatozoa of the giant octopus of the North Pacific, freshly removed from spermatophores, showed very little motility, but on dilution with sea-water or 2.7 % NaCl, followed by dialysis against either of these two media, they became intensely motile and remained so for several days at 2 to 10 °C. At higher temperatures, particularly above 25 °C, octopus spermatozoa lost their motility rapidly. At 35 °C, complete and irreversible loss of motility occurred within less than 1 min. The motility of octopus spermatozoa at 2 to 10 °C persisted under both anaerobic and aerobic conditions and did not require the presence of exogenous glycolysable sugar. The addition of spermatophoric plasma to a motile sperm suspension inhibited motility. Other inhibitors were sodium azide, 2, 4-dinitrophenol and ethylenediaminetetra-acetate, at 0.001 M concentrations. ATP, ADP and arginine phosphate have been identified and quantitatively measured in octopus spermatozoa. On prolonged incubation of motile sperm suspensions a t 3 °C, ATP and ADP did not decline appreciably, whilst arginine phosphate decreased considerably. The decrease was even more pronounced in sperm suspensions which had first been inactivated by short exposure to 35 °C, prior to prolonged incubation at 3 °C. Glycogen, the main carbohydrate store of octopus spermatozoa, remained at a high concentration even in sperm suspensions kept for 5 days at 3 °C, and there was no appreciable difference in that respect between a sample containing motile spermatozoa and one in which, at the outset of incubation, the spermatozoa were immobilized by heating to 35 °C.

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