bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE MECHANISM OF VITAL STAINING WITH BASIC DYES
Authors: McCutcheon Morton , Lucre Baldwin 
Published: May 2004

1. Solutions containing NH4OH and NaOH, and CO2 and HCl may be used to produce various combinations of extracellular and intracellular reactions in starfish eggs, Gonionemus, and Nitella cells.
2. Staining by basic dyes is, with a constant intracellular reaction, favored by increased extracellular alkalinity. With a constant extracellular reaction, staining is hindered by increased intracellular alkalinity.
3. These facts are in opposition to the view that staining of cells by basic dyes is chiefly governed by a combination of the dyes with cell proteins. It is more in harmony with the view that the combination is with a substance or substances of acid nature.
VALENCY RULE AND ALLEGED HOFMEISTER SERIES IN THE COLLOIDAL BEHAVIOR OF PROTEINS
Authors: Kunitz M. 
Published: May 2004

A detailed study was made on the influence of salts on those physicochemical properties of sodium gelatinate which are regulated by Donnan's law of membrane equilibria; namely, osmotic pressure, membrane potentials, and swelling. It was found that the influence of salts on these properties in the case of sodium gelatinate obeys the same rules of valency as in the case of the influence of salts on gelatin chloride as discussed in a previous publication. The rules state that when a salt is added to an ionized protein, without causing a change in the hydrogen ion concentration of the protein, the general effect is a depression of the mentioned properties. The degree of depression depends not only on the concentration of the salt but on the electrical properties of the ions constituting the salt. Of the two or more oppositely charged ions of which a salt consists, only the valency of those ions which carry charges opposite to those carried by the protein ions affects the degree of depression which increases with the valency of the ions.
It was also found that the phenomenon of swelling of gelatin becomes modified by solubility of the gelatin when salts are added in concentrations higher than N/4. Emphasis is laid on the point that the valency rule holds perfectly also in relation to swelling as long as the phenomenon is pure swelling which is the case when salt solutions of concentrations lower than N/4 are added to gelatin.
THE LOCUS OF THE ACTION OF VERATRIN
Authors: Wible Charles L. 
Published: May 2004

1. In Mnemiopsis veratrin shows two stages of veratrin poisoning. First, inhibition of the beats of the plates which disappears on cutting them away either singly or in small groups. Second, after half an hour mechanical stimulation excites the beat of the plates in the intact veratrinized animal. It is concluded that veratrin acts on nervous tissue and not on the substance of the swimming plates.
2. In Lumbricus, veratrin acts on the ventral nerve cord alone, and not on the muscles and peripheral nerves.
3. In Musca, veratrin first causes opisthotonos, then spasms and extreme flexion of the legs. Decapitation causes these effects to disappear hence veratrin acts on the cerebral ganglia of the fly.
4. Veratrin applied to the sciatic nerve of the frog causes, after a latent period of 20 minutes, irregular contractions of the gastrocnemius which persist for an hour or more. Veratrin is thus a neurophil alkaloid of the first class as well as second and in this way resembles tetraethyl ammonium chloride.
5. If the end of a sciatic nerve is dipped into veratrin solution, then direct stimulation of the gastrocnemius muscle results in contraction with delayed relaxation, although the muscle itself is not subject to the action of veratrin.
6. By means of preparations of the sartorius muscle of the frog it is shown that veratrin acts not on the muscle cells directly but on the nerve fibers. Hence veratrin produces the characteristic muscle curve showing delayed relaxation by its action on the nervous elements.
A NOTE ON THE SIMILARITIES BETWEEN THE CURVES OF GROWTH AND OF REGENERATION
Authors: Brody Samuel 
Published: May 2004

The curves of growth and of regeneration follow the same course, and can be represented by the same exponential equation. This is taken to substantiate the theory that growth and regeneration are essentially identical processes governed by the same laws.
A common peculiarity of the curves of growth and of regeneration is that during a short period in the early stages of regeneration and of growth, the apparent observed speed of these processes seems to be relatively slow. As a result, the curve of the fitted equation cuts the time axis not at zero, the beginning of growth or regeneration, but somewhat later. Data on regeneration are cited indicating that the initial slow phase of regeneration is due to the time required for the formation of a cap of embryonic cells which serves as a basis for the more active later regeneration; in other words, to qualitative growth which cannot be expressed in terms of quantitative units. It is suggested that the apparent initial slow phase of growth of the individual from the fertilized egg is due to a similar qualitative growth. It is suggested that if the initial qualitative changes could be converted into some common unit with the subsequent quantitative changes, the apparent initial lag would disappear, and the exponential equation representing the course of these processes would then be the same as the equation used to represent the course of a monomolecular chemical reaction.
Certain implications of this reasoning are discussed in the text.
GROWTH OF MAIZE SEEDLINGS AS AFFECTED BY GLUCOKININ AND INSULIN
Authors: Eyster W. H. , Ellis M. M. 
Published: May 2004

1. Solutions of glucokinin and insulin, particularly those from which the easily dialyzable substances had been removed, increased the growth of roots and tops of young maize seedlings, as shown by comparisons with untreated seedlings grown in distilled water.
2. Strong solutions of crude glucokinin or of crude insulin repressed growth.
3. Seedlings from which the tips of the primary roots had been removed just before placing the plants in the test solutions made greater gains in both top growth and root growth than seedlings with uncut roots treated with solutions of the same strength. Control experiments showed that this difference in growth was not the result of cutting the roots, and that crude glucokinin and crude insulin contained several substances some of which were more readily absorbed by the plant than others.
4. Purification of crude glucokinin and crude insulin by dialysis showed that the residue of relatively non-dialyzable substance was the growth-promoting fraction.
5. The dialysate of crude glucokinin contained at least three types of material, one of which repressed growth.
6. Ammonium sulfate, one of the possible impurities of glucokinin, repressed the growth of seedlings but did not produce the other changes in metabolism shown by seedlings treated with dialysate of onion glucokinin.
7. The endosperm of plants treated with growth-promoting solutions of purified insulin did not lose weight as rapidly as the endosperms of untreated plants, indicating that the treated plants made their greater gains in growth by more efficient utilization of the endosperm, or as a result of greater photosynthetic activity, or by a combination of these.
8. Experiments with albino seedlings suggested that the greater gain in weight made by plants treated with insulin was the result in part of increased photosynthetic activity.
APPLICATION OF THE DIFFUSION HYPOTHESIS TO MEMBRANE POTENTIALS
Authors: Murray Cecil D. 
Published: May 2004

A system consisting of two aqueous solutions, containing equal concentrations of lactic acid, but different concentrations of Na lactate, separated by a layer of amyl alcohol has been described. This system exhibits electrical properties ranging (as the concentration of NaL is increased) from those characteristic of a simple Donnan equilibrium to those characteristic of simple diffusion.
The fact that the Donnan P.D. can be treated as a special case of a diffusion potential has been emphasized.
The experiments call attention to the effect of the thermodynamic properties of the membrane, and it is suggested that such properties as conductivities, ionic mobilities, and distribution coefficients in membranes of any sort should be investigated.
The experiments afford an interesting example of "phase reversal."
Interaction of External K, Na, and Cardioactive Steroids with the Na-K Pump of the Human Red Blood Cell
Authors: Sachs John R. 
Published: May 2004

The interaction of extracellular Na (Nao), K (Ko), and strophanthidin with the Na-K pump of the human red blood cell has been investigated. Inhibition by submaximal concentrations of strophanthidin rapidly reaches a level which does not increase further over a relatively long period of time. Under these circumstances, it is possible to apply a steady-state kinetic analysis to the interaction of Nao, Ko, and strophanthidin with the pump. In Na-free solutions, strophanthidin increases the apparent K1/2 of the pump for Ko, but does not change the form of the relation between the reciprocal of the active K influx (iMKP–1) and the reciprocal of [Ko] ([Ko]–1); the relation both in the presence and absence of strophanthidin is adequately described by a straight line. In solutions containing Na, strophanthidin changes the form of the curve describing the relation between iMKP–1 vs. [Ko]–1; the curve becomes more parabolic in solutions containing strophanthidin. The rate of ouabain binding to K-free cells has also been measured; in the absence of K, the rate of binding is unaffected by Nao. The data are considered in terms of a simple kinetic model.
The findings can be explained if it is supposed that at low external K the form of the pump combined with one Nao is more likely to combine with strophanthidin than is the uncombined form of the pump. The uncombined form of the pump is more likely to combine with K even at very low Ko than with strophanthidin.
THE INFLUENCE OF ELECTROLYTES ON THE STABILITY OF RED BLOOD CORPUSCLE SUSPENSIONS
Authors: Oliver Jean , Barnard Leonard 
Published: May 2004

Two types of stability are observed in suspensions of red blood cells. In weak concentrations of electrolytes the stability depends on the electric charge of the cells and suspension is unstable below a certain critical P.D.
In strong concentrations of electrolyte, the stability bears no relation to the charge.
TEMPERATURE AND FORWARD MOVEMENT OF PARAMECIUM
Authors: Glaser Otto 
Published: May 2004

1. The rate of forward movement in Paramecium as affected by changes in temperature can be described accurately in terms of the Arrhenius equation.
See PDF for Equation
2. For the range from 6–15°, µ = 16,000; from 16–40°, µ = 8,000. These values fall within the limits characteristic for chemical processes.
3. On the principle of velocity control by the slowest rate, it is assumed that in Paramecium at temperatures above normal, control passes from one underlying reaction to another.
4. The views expressed by Rice, the recent results of Crozier, and certain µ values given by Arrhenius all suggest that µ = 16,000 may represent an oxidation, and µ = 8,000 either a modified oxidation or an hydrolysis.
5. For the system of controls, the catenary series O → A → E with the lower µ value attached to the precursor reaction is adequate. We may also assume a cyclical system analogous to Meyerhof's conception of carbohydrate metabolism in muscle. In this case it is necessary to assign µ = 16,000 to the oxidation of A and E and µ = 8,000 to the synthesis E → O. This model also accounts for the fact that the data might be interpreted as involving, apparently, a depletion of A at the higher temperature.
THE EFFECT OF VALENCY OF CATIONS AND ANIONS ON NEGATIVELY AND POSITIVELY CHARGED RED BLOOD CELLS
Authors: Oliver Jean , Barnard Leonard 
Published: May 2004

1. Under comparable conditions, valency effect may be demonstrated with a suspension of red blood cells and the cations and anions of salts.
2. The valency of the cation determines the degree of the effect on negatively charged cells, the valency of the anion, the effect on positively charged cells.
3. Anomalies in valency effects with different salts and red cell suspensions are in part due to variations in H ion concentration, depending on the degree of hydrolysis of the salt.
THE VISUAL DISCRIMINATION OF INTENSITY AND THE WEBER-FECHNER LAW
Authors: Hecht Selig 
Published: May 2004

1. A study of the historical development of the Weber-Fechner law shows that it fails to describe intensity perception; first, because it is based on observations which do not record intensity discrimination accurately, and second, because it omits the essentially discontinuous nature of the recognition of intensity differences.
2. There is presented a series of data, assembled from various sources, which proves that in the visual discrimination of intensity the threshold difference ΔI bears no constant relation to the intensity I. The evidence shows unequivocally that as the intensity rises,
the ratio
See PDF for Equation
first decreases and then increases.
3. The data are then subjected to analysis in terms of a photochemical system already proposed for the visual activity of the rods and cones. It is found that for the retinal elements to discriminate between one intensity and the next perceptible one, the transition from one to the other must involve the decomposition of a constant amount of photosensitive material.
4. The magnitude of this unitary increment in the quantity of photochemical action is greater for the rods than for the cones. Therefore, below a certain critical illumination—the cone threshold—intensity discrimination is controlled by the rods alone, but above this point it is determined by the cones alone.
5. The unitary increments in retinal photochemical action may be interpreted as being recorded by each rod and cone; or as conditioning the variability of the retinal cells so that each increment involves a constant increase in the number of active elements; or as a combination of the two interpretations.
6. Comparison with critical data of such diverse nature as dark adaptation, absolute thresholds, and visual acuity shows that the analysis is consistent with well established facts of vision.
THE KINETICS OF STARVATION
Authors: Wetzel Norman C. 
Published: May 2004

1. The relative weight loss of pigeons on starving rations may be represented by a simple modification of the law of autocatalysis.
2. An equation giving the actual weight of the animals during the 53 day period of the experiment is derived by means of the hypothesis that the process of inanition is governed by the simultaneous velocity relations between two independent, homogeneous systems, such that
MT = (A0 → 0) + (B0 → BC)
in which A is taken proportional to the amount of carbohydrate-fat reserves, and B proportional to the amount of reacting body protoplasm.
3. The course of starvation is governed by the rate of destruction of body protein, but it is modified by the amount and by the rate of destruction of reserve materials.
4. The processes of breaking down tissues are analogous to those by which tissues are synthesized.
5. The close agreement between observed and calculated values suggests that the original assumptions set forth in deriving the foregoing equations were valid.
6. Attention is called to the fact that the time of onset of beriberi in pigeons is coincident with the half period of starvation.
THE ELECTRICAL CONDUCTIVITY OF PURE PROTOPLASM
Authors: Brooks S. C. 
Published: May 2004

The electrical conductivity of the plasmodium of the slime-mold Brefeldia maxima (Fr.) Rost., which constitutes practically pure protoplasm, was found to be approximately equivalent under normal conditions to that of a 0.00145 N NaCl solution, and about 2.8 times that of the liquid in contact with which it developed.
When bathed in 1 per cent sea water, the conductivity was much increased, becoming greater than that of the surrounding fluid.
These preliminary tests are in agreement with the supposition that the protoplasm is permeable to and in equilibrium with its environment in so far as electrolytes are concerned.
NOTE ON THE EXCITATION AND INHIBITION OF LUMINESCENCE IN BERŒ
Authors: Heymans C. , Moore A. R. 
Published: May 2004

1. The ions of Ca and K condition general luminescence, and are therefore necessary to the conduction of the impulse.
2. In van't Hoff's solution from which Mg is omitted, Berœ shows hyperirritability with respect to luminescence. This is the result of the action of Ca and K ions unantagonized by Mg.
3. The luminescent material spread on filter paper does not show luminescence in sea water, NaCl, MgCl2, or saccharose solutions isotonic with sea water. In solutions of CaCl2, SrCl2, BaCl2, KCl, and K2SO4 the indicator paper glows with a bright luminescence.
4. In dark adapted Berœ, luminescence is inhibited by a certain quantity of light. This quantity has an average value of 57,285 meter-candle-minutes, which is twelve times the value given by Mnemiopsis.
THE EFFECT OF LIGHT ON THE PERMEABILITY OF PARAMECIUM
Authors: Packard Charles 
Published: May 2004

1. The permeability of Paramecium to NH4OH is greater when the cells are exposed to light than it is when they are in darkness.
2. This change can be demonstrated in cells exposed to monochromatic red light, though it is small. It becomes greater as the wave lengths shorten, and is greatest in the near ultra-violet.
3. The permeability increases as the duration of exposure to light is prolonged.
4. These experiments demonstrate the necessity of controlling the illumination when using Paramecium in physiological tests.
THE KINETICS OF THE DECOMPOSITION OF PEROXIDE BY CATALASE
Authors: Northrop John H. 
Published: May 2004

It has been shown that the experimental results obtained by Morgulis in a study of the decomposition of hydrogen peroxide by liver catalase at 20°C. and in the presence of an excess of a relatively high concentration of peroxide are quantitatively accounted for by the following mechanisms.
1. The rate of formation of oxygen is independent of the peroxide concentration provided this is greater than about 0.10 M.
2. The rate of decomposition of the peroxide is proportional at any time to the concentration of catalase present.
3. The catalase undergoes spontaneous monomolecular decomposition during the reaction. This inactivation is independent of the concentration of catalase and inversely proportional to the original concentration of peroxide up to 0.4 M. In very high concentrations of peroxide the inactivation rate increases.
4. The following equation can be derived from the above assumptions and has been found to fit the experiments accurately.
See PDF for Equation
in which x is the amount of oxygen liberated at the time t, A is the total amount of oxygen liberated (not the total amount available), and K is the inactivation constant of the enzyme.
THE GROWTH OF DUCKWEEDS IN MINERAL NUTRIENT SOLUTIONS WITH AND WITHOUT ORGANIC EXTRACTS
Authors: Saeger Albert 
Published: May 2004

1. Detmer's solution and a modified Knop's solution are unfavorable culture media for the growth of Spirodela polyrhiza.
2. When the modified Knop's solution was diluted to 10 times its volume, Spirodela polyrhiza and Lemna valdiviana grew and reproduced for periods of 26 months and 21 months, respectively.
3. Growth in the dilute Knop's solution, which alone can support the growth of Spirodela indefinitely, was considerably stimulated over a period of 23 days by adding to every liter the water-soluble material of 0.4 gm. autolyzed yeast, or the material of 2.5 gm. peat soluble in a 1 per cent solution of NaHCO3.
4. The nature of the stimulus or of the protection afforded by the organic material is as yet unknown.
5. The necessity of organic accessory foods (auximones) in the nutrition of green plants cannot be accepted as an established fact.
METABOLISM DURING EMBRYONIC AND METAMORPHIC DEVELOPMENT OF INSECTS
Authors: Fink David E. 
Published: May 2004

1. For species of insects that deposit their eggs on foliage, as Leptinotarsa decemlineata, Crioceris asparagi, and Anasa tristis, the rates of metabolism as measured by the CO2 output or the oxygen intake indicate, during embryonic development, a short formative period, followed by a very active extended growth. Those species that deposit their eggs in the soil, as Cotinis nitida and Popillia japonica, show that the formative period is greatly extended and the growth period similarly lengthened.
2. It has been shown from metabolism experiments that intensive histolysis occurs during the prepupal period and becomes less intensive during pupal development.
3. Metabolism experiments show a greater amount of energy change during embryonic development as compared to the energy developed during metamorphosis. This is shown by the greater CO2 output and by the oxygen intake.
4. Low respiratory quotients, varying from 0.42 to 0.71, have been obtained during the embryonic and pupal development of insects, resembling similar low quotients obtained with hibernating forms.
5. Changes from a neutral to an acid reaction (pH 6.8 to 5.9) have been observed to take place in some species during prepupal and early pupal development. As metamorphosis is completed a converse change occurs (pH 5.9 to 6.8). Changes in pH from an acid to neutral reaction were also observed to take place in some species, as Cotinis nitida and Hylemyia cilicrura, during embryonic development.
PULSATION OF THE CONTRACTILE VACUOLE OF PARAMECIUM AS AFFECTED BY TEMPERATURE
Authors: Cole William H. 
Published: May 2004

1. The rate of pulsation of the anterior contractile vacuole of Paramecium caudatum under chloretone anesthesia has been determined over a range of temperatures from 9–31°C. It has been found that the rate is a logarithmic function of the temperature according to the Arrhenius equation. From 9–16° the temperature characteristic (µ) has the value 25,600; from 16–22° it is 18,900; and from 22–31° it becomes 8,600.
2. It is concluded that there are at least three underlying reactions responsible for pulsation, the rates of which vary. Which reaction becomes the limiting one depends upon the range of temperature considered.
3. It does not appear that oxidative processes alone determine the rate of pulsation, although they may be of fundamental importance.
A TEST FOR DIFFUSIBLE IONS
Authors: Northrop John H. 
Published: May 2004

1. The distribution of pepsin between particles of gelatin or coagulated egg albumin and the outside solution has been found to be equal to the distribution of chloride or bromide ion under the same conditions. This is the case from pH 1 to 7, and in the presence of a variety of salts.
2. Pepsin is therefore probably a monovalent anion.
3. Under certain conditions the enzyme may be adsorbed on the surface of the protein particles. This reaction is irreversible and is markedly influenced by the presence of low concentrations of electrolytes.
THE PRODUCTION OF CARBON DIOXIDE BY NERVE
Authors: Parker G. H. 
Published: May 2004

1. A modified Osterhout respiratory apparatus for the detection of CO2 from nerve is described.
2. The lateral-line nerve from the dogfish discharges CO2 at first with a gush for half an hour or so and then steadily at a lower rate for several hours.
3. Simple handling of the nerve does not increase the output of CO2; cutting it revives gush.
4. The CO2 produced by nerve is not escaping simply from a reservoir but is a true nervous metabolite.
5. The rate of discharge of CO2 from a quiescent nerve varied from 0.0071 to 0.0128 mg. per gram of nerve per minute and averaged 0.0095 mg.
6. Stimulated nerve showed an increased rate of CO2 production of 15.8 percent over that of quiescent nerve.
7. The results of these studies indicate that chemical change is a factor in nerve transmission.