Varying Ion Concentrations Research Articles

Indirect evidence of the importance of water-soluble continentally derived aerosols

The Ca++/Cl– ratio is a logical index of the predominance of continental or marine water-soluble aerosols in precipitation. Use of this ratio and others indicates that, excluding immediate coastal areas, continental aerosols constitute a large majority of the soluble material brought down in precipitation over land. The correlation of the concentrations of various ions in precipitation with the regional distribution of these elements in the soil presents further support for this conclusion.

Voltage-Clamp Experiments with Nitella

HOPE1 has suggested that in the large internodal cells of Chara australis, the depolarization of the plasmalemma during an action potential is caused by a sudden transient increase in the permeability of this membrane to calcium ions, and a consequent inward movement of these ions. This suggestion followed from an investigation of the effects of changes in concentration of various ions on the action potential in single Chara cells.

The Plateau of the Action Potential of the Frog Ventricle

A study was made of the changés produced in action potentials of frog ventricular cells by variation in ion concentrations, by administration of NaN 3 , 2:4 DNP, NaCN, NaIA and N 2 which shortened the potentials. The exposure of the perfused tissue to ionized acridines, barbiturates and desoxyglucose caused a prolongation of the action potentials. These actions as obtained were reversible. The evidence from the time-course and differential effects of inhibitors suggests that an active ion transport, modulated by K o + may be important in maintaining the plateau phase of the action potential.

The composition of the Orion Nebula.

view Abstract Citations References Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS The composition of the Orion Nebula. Aller, Lawrence H. ; Liller, William Abstract Photoelectric spectrophotometric measurements of line intensities in the Orion Nebula are combined with Wyse's photographic measurements for the weaker lines to obtain the concentrations of various ions of the permanent gases. As noted by Osterbrock and others, there is evidence for large density fluctuations in this object. We have adopted a mean electron density NE = 4 X i~~ from the forbidden lines and TE = 90000K from the photoelectrically measured ~4363/ (N1 + N2) ratio. Approximate cross- sections have had to be used for sulfur, chlorine, and argon. A fairly well-defined empirical ionization curve was obtained. The following table compares the nebular abundances with those of early type stars as determined in the Michigan program: logN logN Star Nebula Star Nebula Nitrogen 9.2 9.1 Sulphur 9.0 9.1 Oxygen 10.0 10.0 Chlorine 8.7 7.3 Neon 10.1 10.2 Argon 8.4 8.6 University of Michigan Observatory, Ann Arbor, Mich. Publication: The Astronomical Journal Pub Date: 1959 DOI: 10.1086/108011 Bibcode: 1959AJ.....64R..49A full text sources ADS |

Electrophoresis of the blood of the silkworm, Bombyx mori on filter paper

1) The daily change of the electrophoretic pattern of the silkworm blood from larval to pupal stage was examined. Three components (b3, b2, b1) were present in the blood of the early period of the 5th instar as shown in the previous paper (AIZAWA, 1955), while from 4-5th day of the 5th instar to pupal stage, there appeared two components, which were densely stained (Figs. 1, 3). In the latter case, when the electrophoresis was performed with the diluted blood, three protein components could be clearly detected (Fig. 2). b3 is the fastest moving component and it seems to be albumin. b2 and b1 are probably globulin. b3 component decreased with the pupal age and finally disappeared, at earlier time in male than in female.2) Comparison of the electrophoretic patterns was made by veronal, phosphate, citrate, borate or tris (hydroxymethyl) aminomethane buffer with the varying ion concentration and pH. The separation of the protein fractions with veronal buffer (pH 8.6, I=0.05) was better than with other buffers.3) Comparison of staining, was examined using bromphenol blue, solar blue black and amido black. All dyes were suitable for the purpose. By sudan black staining, b3 component was slightly stained (Fig. 4).4) Paper strips were cut off from the electrophoresis paper of the jaundice-diseased blood at the regions of b3, b2+b1 and the starting line as shown in Fig. 5. The virus was extracted with the distilled water and the injection experiments were performed. The virus amount was highest in b2+b1 fractions and it decreased in the fraction from near the starting line. The virus activity was scarecely shown in the fraction of b3.5) Any difference, except for quantitative one was not observed in the electrophoretic patterns of the blood between the normal and diseased larvae (both nuclear and cytoplasmic polyhedroses). On the contrary, the pattern of Galleria mellonella is, however, different from that of Galleria-adapted silkworm jaundice virus (Aizawa, unpub.).

Variations in Concentration of Ions in Aqueous Humor : Following Paracentesis in the Contralateral Eye

Variations in Concentration of Ions in Aqueous Humor : Following Paracentesis in the Contralateral Eye

Dynamic Characteristics of the Plasma in Discharges through Rare Gases

The time variation of ion concentration in the plasma of flash discharges through neon and argon at low pressures has been determined from the Stark broadening of ${H}_{\ensuremath{\alpha}}$ and ${H}_{\ensuremath{\beta}}$ lines. Hydrogen gas at about 1 percent of the total pressure was used for this purpose. A special method of oscilloscopic observation is employed. Analysis of the results explains differences in the time of appearance of various types of radiation in the discharge. A mechanism is proposed to account for the time variation of the intense continuum.

A Practical Method for the Determination of the Chloride Content for Plant Tissue Fluids

A long series of investigations carried out over a wide geographic range has shown that the physico-chemical properties of leaf tissue fluids vary from habitat to habitat in correlation with environmental conditions. An outline of problems was drawn some years ago (Harris 'I7) and a brief review of results has been given as an introduction to a recent investigation of the vegetation of Tooele Valley, Utah (Harris et al., '24b) and in explanation of the application of tissue fluid studies to agricultural problems (Harris et al., '24a). The mass of evidence now accumulating tends to show that the differences demonstrable in the tissue fluids of plants of various habitats are in part due to innate differentiation of the species and in part to direct influence of environmental conditions. This is clear from unpublished work on various wild species growing under diverse environmental conditions and has been established experimentally for small cultivated tracts by investigations on the variation and differentiation of Egyptian and Upland cotton (Harris et al., '24a). The investigations of Cavara ('05) and Fitting ('II), and subsequent studies by our coworkers and ourselves, have shown that plants growing under saline conditions may be characterized by enormously high osmotic concentrations. We have noted, for example, that during periods of drought Atriplex confertifolia and Atriplex nuttallii may exhibit concentrations far above ioo atmospheres (Harris et al., '2I) . It seems probable that ions absorbed from the soil contribute largely to the development of such concentrations. In the analysis of the variables to which differences in osmotic concentration are due it therefore becomes of great importance to determine by precise analytical methods the concentration of various ions and of inorganic and organic molecules in the plant tissue fluids. Because of their widespread and abundant occurrence and high solubility chlorides seem one of the most important constituents to be determined. While a score or more papers on the detrmination of chlorides in blood and urine have been presented by biochemists and animal physiologists, and while one of these methods has been modified with a view to fitting it for