bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE PHYSIOLOGICAL BASIS OF MORPHOLOGICAL POLARITY IN REGENERATION. II
Authors: Loeb Jacques 
Published: May 2004

1. The experiments show that the mass of air roots formed in a stem increases with the mass of the leaf attached to the stem, though it has not been possible to establish an exact mathematical relation between the two masses, owing to unavoidable sources of error.
2. Darkened leaves do not increase the mass of roots formed.
3. In stems suspended horizontally air roots appear on the lower side of the stem, with the exception of the cut end where they usually appear around the whole circumference of the stem. When the lower half of a stem suspended horizontally is cut off, roots are formed on the upper side. It is shown by experiments on leaves suspended horizontally that the more rapidly growing roots and shoots on the lower side inhibit the root and shoot formation in the upper half of such a leaf; and likewise the more rapid formation of roots on the lower side of a horizontally suspended stem seems to account for the inhibition of root formation on the upper side of such a stem. Likewise the more rapid growth of shoots on the upper side of a stem suspended horizontally is likely to inhibit the growth of shoots on the lower side.
4. Each leaf contains in its axil a preformed bud capable of giving rise to a root, which never grows out in the normal stem on account of the inhibitory influence of the normal roots at the base of the plant. These dormant root buds are situated above (apically from) the dormant shoot bud. The apical root buds can be caused to develop into air roots when a piece of stem is cut out from a plant from which the leaves except those in the basal node of the piece are removed. The larger these basal leaves the better the experiments succeed.
5. These apical air roots grow out in a few days, while the roots at the basal end of the stem (which in our experiments dip into water) grow out about a week later. As soon as the basal roots grow out in water they cause the air roots in the more apical region of the stem to dry out and to disappear.
6. In addition to the basal roots, basal nodes have also an inhibitory effect on the growth of the dormant root buds in the apical region of a stem. This is indicated by the fact that a stem with one pair of leaves near the base will form apical air roots more readily when no node is situated on the stem basally from the leaf than if there is a node basally from the leaf.
STUDIES ON ENZYME ACTION
Authors: Noyes Helen Miller , Lorberblatt I. , Falk K. George 
Published: May 2004

The hydrolyzing actions of various preparations of the adult eel were studied on ten esters in the usual way. The results are presented in the form of curves for the relative actions and in a table for the absolute actions obtained in one complete experiment.
The separation of the enzyme material in some cases into an active portion and a co-enzyme, the mixture showing greater actions on some esters than the sums of the individual actions, is described and discussed.
FURTHER STUDIES ON THE INHIBITION OF CYPRIDINA LUMINESCENCE BY LIGHT, WITH SOME OBSERVATIONS ON METHYLENE BLUE
Authors: Harvey E. Newton 
Published: May 2004

1. Eosin, erythrosin, rose bengale, cyanosin, acridine, and methylene blue act photodynamically on the luminescence of a Cypridina luciferin-luciferase solution. In presence of these dyes inhibition of luminescence, which without the dye occurs only in blue-violet light, takes place in green, yellow, orange, or red light, depending on the position of the absorption bands of the dye.
2. Inhibition of Cypridina luminescence without photosensitive dye in blue-violet light, or with photosensitive dye in longer wave-lengths, does not occur in absence of oxygen. Light acts by accelerating the oxidation of luciferin without luminescence. Eosin or methylene blue act by making longer wave-lengths effective, but there is no evidence that these dyes become reduced in the process.
3. The luciferin-oxyluciferin system is similar to the methylene white-methylene blue system in many ways but not exactly similar in respect to photochemical change. Oxidation of the dye is favored in acid solution, reduction in alkaline solution. However, oxidation of luciferin is favored in all pH ranges from 4 to 10 but is much more rapid in alkaline solution, either in light or darkness. There is no evidence that reduction of oxyluciferin is favored in alkaline solution. Clark's observation that oxidation (blueing) of methylene white occurs in complete absence of oxygen has been confirmed for acid solutions. I observed no blueing in light in alkaline solution.
THE INFLUENCE OF LIGHT, TEMPERATURE, AND OTHER CONDITIONS ON THE ABILITY OF NITELLA CELLS TO CONCENTRATE HALOGENS IN THE CELL SAP
Authors: Hoagland D. R. , Hibbard P. L. , Davis A. R. 
Published: May 2004

1. By the use of a special analytical technique it has been possible to study the accumulation of halogens in the cell sap of Nitella.
2. From a dilute solution, Br may be accumulated in the sap in a concentration much greater than that of the external solution. The conductivity of the sap may be markedly increased by such accumulation. The process is a slow one so that a month or more may be required to approach equilibrium.
3. Cl may be lost from the cell as a result of the accumulation of Br and vice versa. Other reciprocal relations between Cl and Br are indicated.
4. At equilibrium practically as much Br accumulated in the sap with an external solution containing 1 milli-equivalent of Br as with one containing 5 milli-equivalents.
5. Light energy was indispensable to the accumulation of Br. The temperature coefficient was characteristic of a chemical process.
THE EFFECT OF THE pH ON THE GERMICIDAL ACTION OF SOAPS
Authors: Eggerth Arnold H. 
Published: May 2004

1. The effect of the pH on the germicidal action of soaps has been studied. The lower members of the series were found to be most active in acid solution; the higher members, in alkaline. The point of transition varied with the test organism used.
2. This is probably due to the effect of the pH on the dissociation residue and on the solubility of the soap. The dissociation residue may affect the germicidal titer by modifying the surface tension, the penetration into the bacteria, and the partition coefficient of the germicide between bacteria and water.
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THE SWELLING PRESSURE OF GELATIN AND THE MECHANISM OF SWELLING IN WATER AND NEUTRAL SALT SOLUTIONS
Authors: Northrop John H. , Kunitz M. 
Published: May 2004

1. A method is described for measuring the swelling pressure of solid gelatin.
2. It was found that this pressure increases rapidly between 15° and 37°C., and that the percentage change is nearly independent of the concentration of gelatin.
3. It is suggested that this pressure is due to the osmotic pressure of a soluble constituent of the gelatin held in the network of insoluble fibers, and that gelatin probably consists of a mixture of at least two substances or groups of substances, one of which is soluble in cold water, does not form a gel, and has a low viscosity and a high osmotic pressure. The second is insoluble in cold water, forms a gel in very low concentration, and swells much less than ordinary gelatin.
4. Two fractions, having approximately the above properties, were isolated from gelatin by alcohol precipitation at different temperatures.
5. Increasing the temperature and adding neutral salts greatly increase the pressure of the insoluble fraction and have little effect on that of the soluble fraction.
6. Adding increasing amounts of the soluble fraction to the insoluble one results in greater and greater swelling.
7. These results are considered as evidence for the idea that the swelling of gelatin in water or salt solutions is an osmotic phenomenon, and that gelatin consists of a network of an insoluble substance enclosing a solution of a soluble constituent.
CONCERNING THE INFLUENCE OF POLARIZED LIGHT ON THE GROWTH OF SEEDLINGS
Authors: Macht David I. 
Published: May 2004

While these experiments are not exhaustive, a sufficient number have been made to warrant the statement that the effect of polarized light of the visible spectrum on the growth of various seedlings and
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more particularly on the growth of Lupinus albus is somewhat different from that of non-polarized light. This is especially convincing in view of the results obtained with double sets of plants which were alternately exposed to polarized and non-polarized lights of the same intensities and at the same temperature. In every experiment thus performed the set which was placed in a polarizing chamber grew better. It is, furthermore, interesting to note that the phenomenon above observed did not take place when the seed portion of the plants was protected from light by wrapping with tinfoil. This agrees well with previous findings concerning the action of diastase on starch in polarized light. The above researches will be continued on a more elaborate scale but the results so far obtained are deemed worthy of publication in the form of a preliminary communication at the present time.
EXIT OF DYE FROM LIVING CELLS OF NITELLA AT DIFFERENT pH VALUES
Authors: Irwin Marian 
Published: May 2004

Experiments on the exit of brilliant cresyl blue from the living cells of Nitella, in solutions of varying external pH values containing no dye, confirm the theory that the relation of the dye in the sap to that in the external solution depends on the fact that the dye exists in two forms, one of which (DB) can pass through the protoplasm while the other (DS) passes only slightly. DB increases (by transformation of DS to DB) with an increase in the pH value, and is soluble in substances like chloroform and benzene. DS increases with decrease in pH value and is insoluble (or nearly so) in chloroform and benzene.
The rate of exit of the dye increases as the external pH value decreases. This may be explained on the ground that DB as it comes out of the cell is partly changed to DS, the amount transformed increasing as the pH value decreases.
The rate of exit of the dye is increased when the pH value of the sap is increased by penetration of NH3.
TEMPERATURE AND FREQUENCY OF HEART BEAT IN THE COCKROACH
Authors: Fries E. F. B. 
Published: May 2004

The frequency of pulsation of the intact heart in nymphs (final (?) instar) of Blatta orientalis L. increases with the temperature according to the equation of Arrhenius. The constant µ has typically the same value, within reasonable limits of error, as that (12,200) deduced for other, homologous activities of arthropods where the rate of central nervous discharge is perhaps the controlling element, namely 12,500 ± calories for temperatures 10–38°C. Below a critical temperature of about 10° a change to a higher value of the temperature characteristic occurs, such that µ = 18,100 ±. Exceptionally (one individual) µ = 14,100 ± over the whole range of observed temperature (4.5–28°).
The quantitative correspondence of µ for frequency of heart beat in different arthropods adds weight to the conception that this constant may be employed for the recognition of controlling processes.
THE PENETRATION OF BASIC DYE INTO NITELLA AND VALONIA IN THE PRESENCE OF CERTAIN ACIDS, BUFFER MIXTURES, AND SALTS
Authors: Irwin Marian 
Published: May 2004

When living cells of Nitella are exposed to an acetate buffer solution until the pH value of the sap is decreased and subsequently placed in a solution of brilliant cresyl blue, the rate of penetration of dye into the vacuole is found to decrease in the majority of cases, and increase in other cases, as compared with the control cells which are transferred to the dye solution directly from tap water. This decrease in the rate is not due to the lowering of the pH value of the solution just outside the cell wall, as a result of diffusion of acetic acid from the cell when cells are removed from the buffer solution and placed in the dye solution, because the relative amount of decrease (as compared with the control) is the same whether the external solution is stirred or not.
Such a decrease in the rate may be brought about without a change in the pH value of the sap if the cells are placed in the dye solution after exposure to a phosphate buffer solution in which the pH value of the sap remains normal. The rate of penetration of dye is then found to decrease. The extent of this decrease is the greater the lower the pH value of the solution.
It is found that hydrochloric acid and boric acid have no effect while phosphoric acid has an inhibiting effect at pH 4.8 on stirring.
Experiments with neutral salt solutions indicate that a direct effect on the cell (decreasing penetration) is due to monovalent base cations, while there is no such effect directly on the dye.
It is assumed that the effect of the phosphate and acetate buffer solutions on the cell, decreasing the rate of penetration, is due (1) to the penetration of these acids into the protoplasm as undissociated molecules, which dissociate upon entrance and lower the pH value of the protoplasm or to their action on the surface of the protoplasm, (2) to the effect of base cations on the protoplasm (either at the surface or in the interior), and (3) possibly to the effect of certain anions. In this case the action of the buffer solution is not due to its hydrogen ions.
In the case of living cells of Valonia under the same experimental conditions as Nitella it is found that the rate of penetration of dye decreases when the pH value of the sap increases in presence of NH3, and also when the pH value of the sap is decreased in the presence of acetic acid. Such a decrease may be brought about even when the cells are previously exposed to sea water containing HCl, in which the pH value of the sap remains normal.
THE RÔLE OF CERTAIN METALLIC IONS AS OXIDATION CATALYSTS
Authors: Cook S. F. 
Published: May 2004

1. When iron and copper are allowed to act on hydrogen peroxide and pyrogallol, enough carbon dioxide is produced to be readily measured.
2. The curve of the production of carbon dioxide may be fitted by an empirical equation, by the use of which the initial rate and the total amount of the oxidation may be determined.
3. The effect of the concentration of the reagents is different in each case, the effect varying as a fractional power of the copper and pyrogallol concentrations and as a logarithmic function of the hydrogen peroxide concentration.
4. When gold or silver is used the rate changes suddenly during the course of the reaction due to the precipitation of colloidal metal.
5. Mercury, cadmium, zinc, tin, and some other metals have no effect.
6. A theoretical set of equations is assumed to account for the action of the metals.
7. The metals are assumed to act by means of the formation of intermediate peroxides.
8. Experiments on the action of gold indicate that the metals are active in the ionic and not in the colloidal state.
AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS
Authors: Stearn Allen E. 
Published: May 2004

Electrometric titrations of glycine, sulfanilic acid, and various mixtures of the two have been made. These mixtures are shown to give a curve which, between their respective isoelectric points, is different from that of either substance. These mixtures have a maximum buffering power at a pH which can be theoretically calculated, and which has the characteristics of an "isoelectric point of the system."
Other pairs of ampholytes are shown to act in an analogous manner.
PHYSIOLOGICAL ONTOGENY
Authors: Murray Henry A. ,   With the Assistance of Yetta Porosowsky.
Published: May 2004

1. The previous findings that the rate of metabolism per gm. of body weight decreased with age, and that during the incubation period catabolism was mostly at the expense of fat, have been confirmed.
2. These determinations of the rate of oxygen uptake have afforded more precise values for the catabolic rate and thus permit estimations of the changes with age in the rate of absorption.
AMPHOTERIC BEHAVIOR OF COMPLEX SYSTEMS
Authors: Stearn Allen E. 
Published: May 2004

From the solubility minimum the value of the basic ionization constant of sulfanilic acid is shown to lie probably between the values 1.7 x 10–15 and 3.2 x 10–15. From solubility measurements the value of this same constant is shown to lie probably between 2.0 and 2.2 x 10–15, and the isoelectric point of sulfanilic acid is thus at a cH of 0.056 or a pH of 1.25. From conductivity ratios the acid ionization constant of sulfanilic acid is shown to be 7.05 x 10–4 at room temperature (21°C.).
Calculations are made, from data published in preceding papers, of the ionization constants of glycine, Ka being 2.3 x 10–10, and Kb being 2.2 x 10–12.
CERTAIN EFFECTS OF SALTS ON THE PENETRATION OF BRILLIANT CRESYL BLUE INTO NITELLA
Authors: Irwin Marian 
Published: May 2004

The effect of various substances on living cells may be advantageously studied by exposing them to such substances and observing their subsequent behavior in solutions of a basic dye, brilliant cresyl blue.
The rate of penetration of the basic dye, brilliant cresyl blue, is decreased when cells are exposed to salts with monovalent cations before they are placed in the dye solution (made up with borate buffer mixture). This inhibiting effect is assumed to be due to the effect of the salts on the protoplasm.
This effect is not readily reversible when cells are transferred to distilled water, but it is removed by salts with bivalent or trivalent cations. In some cases it disappears in dye made up with phosphate buffer mixture, or with borate buffer mixture at the pH value in which the borax predominates, and in the case of NaCl it disappears in dye containing NaCl.
No inhibiting effect is seen when cells are exposed to NaCl solution containing MgCl2 before they are placed in the dye solution.
The rate of penetration of dye is not decreased when cells are previously exposed to salts with bivalent and trivalent cations.
The rate is slightly increased when cells are placed in the dye solution containing a salt with monovalent cation and probably with bivalent or trivalent cations. In the case of the bivalent and trivalent salts the increase is so slight that it may be negligible.
THE AUTODESTRUCTION OF PEPSIN IN RELATION TO ITS IONIZATION
Authors: Goulding Arthur M. , Borsook Henry , Wasteneys Hardolph 
Published: May 2004

1. Evidence is presented that pepsin is a univalent acid with a value for pK of 6.85 (or a base, with pK 7.39).
2. The autodestruction of the pepsin is shown to be dependent in part upon an instantaneous irreversible change occurring in the ionized form of the enzyme (if it be an acid) or in the unionized form (if it be a base).
3. A further progressive autodestruction of pepsin at any given hydrogen ion concentration and temperature is defined by the mass law equation for a monomolecular reaction
4. The velocity of autodestruction of pepsin is directly proportional to the hydroxyl ion concentration. It is much less in the range of hydroxyl ion concentration from pOH 9.89-7.7, than in the range greater than pOH 7.7. In both of these ranges variations in pK with pOH may be represented by straight lines.
THE EFFECT OF CERTAIN RESPIRATORY INHIBITORS ON THE RESPIRATION OF CHLORELLA
Authors: Emerson Robert 
Published: May 2004

Chlorella, when made heterotrophic by means of certain sugars, respires like other heterotrophic cells when subjected to the respiratory inhibitors, hydrocyanic acid, hydrogen sulfide, and carbon monoxide.
Whether the case of Chlorella is typical for green cells in general remains to be seen. Experiments with various other green organisms are being carried out, in hope of settling this point.
THE PROTEIN ASSOCIATED WITH HEMOLYSIN IN RABBIT SERUM AND PLASMA
Authors: Coulter Calvin B. 
Published: May 2004

1. The water-insoluble globulin with which hemolysin is associated, may be separated from immune serum or plasma by dilution and simple dialysis at optimal pH.
2. This optimum in plasma is influenced by the presence of the fibrinogen.
3. Fibrinogen carries no immune body, or only an insignificant amount; when present in immune body solutions in other form than fibrin gel, it depresses the hemolytic activity. The conditions for the formation of fibrin gel are similar to those for the formation of a gel by banana protein.
4. The hemolytic activity is a more labile property of the immune protein than the agglutinating activity; hemolysin is destroyed, hemagglutinin shows an apparent increase, as a result of alcohol extraction.
"GALVANOTROPISM" OF ROOTS
Authors: Navez A. E. 
Published: May 2004

1. New experiments, made in such a way to eliminate as completely as possible products of polarization and the migration of such products when formed, have shown that the exhibition of galvanotropic curvature in roots is mainly dependent upon such products, since no curvature appears when they are excluded.
2. The polarization products injure the external layer of cells of the root; this allows these cells to act as electrodes directly applied on the internal tissues. The inner electrolysis produces such changes in the interior cells that they may be considered as becoming ionically different. This differential state is responsible for curvature.
3. "Galvanotropism" of roots, therefore, cannot be regarded as exactly comparable to the galvanotropic orientations of certain animals, but is essentially dependent upon injury.
THE FREE ENERGY OF NITROGEN FIXATION BY LIVING FORMS
Authors: Burk Dean 
Published: May 2004

Fixation of nitrogen even with liberation of energy or free energy, will take place if either oxygen gas or hydrogen gas, or other substances, especially gases, whose standard free energies are close to zero, are involved to form either nitrates, ammonia, or cyanide, not to speak of still other compounds. It has been pointed out that there are two and only two general conditions where nitrogen fixation can require energy. These are, first, if nitrogen reacts with some compound like water with an already high negative free energy of formation and where negligible oxidation of nitrogen would occur; second, if the plant does not take advantage of working at concentrations where the process would yield free energy.
If nitrogen fixation is exothermic and free energy-yielding, how is the carbohydrate requirement of nitrogen-fixing organisms to be interpreted? Are the experimental determinations of the carbon to nitrogen ratio purely circumstantial? Is further hope given to those who may experimentally try to narrow this ratio to where the carbon used is only for the carbon requirements of general metabolism, exclusive of fixation? Do not hypotheses concerning the fixation of nitrogen in the evolutionary process, which are based on the conception that energy is required, lose some of their significance? Does it not suggest that perhaps fixation is far more universal than is supposed among living forms, particularly among the higher green plants, and thereby give encouragement to those who may wish to demonstrate this experimentally? Does it not indicate that perhaps the function of fixation is often to obtain energy for use in general metabolism? Is the general carbohydrate metabolism of the fixation forms to be regarded as being merely extremely inefficient? Or most suggestive of all, is the carbohydrate serving some unobserved function?