bluuebunny/crossref_metadata_2025_split huggingface dataset:
STUDIES ON PENETRATION OF DYES WITH GLASS ELECTRODE
Authors: Irwin Marian 
Published: May 2004

Glass electrode measurements of the pH value of the sap of Nitella show that cresyl blue in form of free base penetrates the vacuoles and raises pH value of the sap to about the same degree as the free base of the dye added to the sap in vitro, while the dye salt dissolved in the sap does not alter its pH value. It is proved conclusively that the increase in the pH value of the sap is due only to the presence of the dye and not to some other alkaline substance.
Spectrophotometric measurements show that the dye which penetrates the vacuole is chiefly cresyl blue.
When the protoplasm is squeezed into the sap, the pH value of the sap is higher than that of the pure sap. Such a mixture behaves very much like the sap in respect to the dye.
THE INTRINSIC RHYTHM OF THE TURTLE'S HEART STUDIED WITH A NEW TYPE OF CHRONOGRAPH, TOGETHER WITH THE EFFECTS OF SOME DRUGS AND HORMONES
Authors: Loomis Alfred L. , Harvey E. Newton , MacRae C. 
Published: May 2004

A chronograph is described for recording continuously the rates of many different kinds of rhythmic processes over long time periods. The rate is read directly from the length of a line of ink, drawn by a moving pen.
Rates of beat of excised turtle's hearts in Ringer's solution have been recorded at 25°C. under constant conditions of temperature, pH, and oxygen supply for periods of 36 hours. Regular periodic variations in the fundamental rhythm are figured, as well as rates of extraordinary constancy. The effects of adrenalin, ephedrin, thyroxin, α and ß pituitary hormone insulin, nicotin, and atropin are described in the text.
THE ACCUMULATION OF ELECTROLYTES
Authors: Cooper Wm. C. , Osterhout W. J. V. 
Published: May 2004

When 0.005 M NH4Cl is added to sea water containing cells of Valonia macrophysa ammonia soon appears in the sap and may reach a concentration inside over 40 times as great as outside. It appears to enter as undissociated NH3 (or NH4OH) and tends to reach a pseudoequilibrium in which the activity of undissociated NH3 (or NH4OH) is the same inside and outside.
When ammonia first enters, the pH value of the sap rapidly rises but it soon reaches a maximum and subsequently falls off. At the same time there is an increase of halide in the sap which, however, does not run a parallel course to the ammonia accumulation, but it comes to a new equilibrium value and remains constant.
The increase in NH3 in the sap is accompanied by a decrease in the concentration of K.
As NH3 enters the specific gravity of the sap decreases and the cells rise to the surface and continue to grow as floating organisms. The growth of the cells is increased.
THE ARGININE AND PREARGININE GROUPS IN EDESTIN
Authors: Simms Henry S. 
Published: May 2004

The author corroborates the data of Schmidt showing that the dissociation index of the third group of arginine is pK3' = 12.5.
New titration data of edestin have been obtained in very alkaline solutions and show that there is a corresponding group with a titration index of pG' = 12.0, but present in much less quantity than can account for the arginine found on hydrolysis. The data support the theory that the combination of strong base or strong acid with proteins is produced by the formation of salts with the "extra groups" of those trivalent amino acids which can be isolated from the protein, with the exception of arginine. Arginine contributes to the titration curve in much smaller amount than is found on hydrolysis. This deficiency in the arginine group may be accounted for by the basic group in proteins having a titration index of pG' = 3.8 to 4.6 (depending on the protein), which apparently yields arginine on hydrolysis, and may properly be called prearginine.
THE CONDITIONS OF RECOVERY OF TRANSMISSIVITY OF NEWLY REPASSIVATED IRON WIRES IN NITRIC ACID
Authors: Lillie Ralph S. 
Published: May 2004

1. Passive steel wires were activated in a bath (Bath A) containing 70 v. per cent HNO3 (in which they undergo prompt repassivation), and immediately transferred to a second bath (Bath B) containing HNO3 of a concentration varying in different experiments. After varying intervals in this bath they were transferred while still passive to a third bath (Bath C) containing strong HNO3 (70 or 100 v. per cent) and there immediately activated.
2. During the immersion in Bath B the wires progressively recover their ability to transmit activation waves in strong HNO3. The measure of this recovery is the distance travelled by the activation waves in Bath C after the varying times of exposure in Bath B. Transmissivity as thus measured is at first incomplete (decremental) and later becomes complete. The minimal exposures in Bath B required to render wires completely transmissive in the strong acid of Bath C were determined for concentrations of HNO3 between 10 and 100 v. per cent. With 100 v. per cent HNO3 in Bath C, these exposures range from 40 minutes or more in 15 v. per cent to 10 minutes in 100 v. per cent HNO3 (temperature 19–20° in all baths).
3. The time required for complete recovery varies inversely with the concentration of the acid in the recovery bath (Bath B), but increases rapidly with the concentration of the acid in the testing bath (Bath C). Hence at a time when a wire has recovered just sufficiently to transmit non-decrementally in a given strong acid (e.g., 70 v. per cent) it still transmits decrementally in a stronger acid. Complete recovery for transmission in 100 v. per cent HNO3 requires about twice as long as for 70 v. per cent HNO3. In HNO3 of 50 v. per cent and less decremental transmission does not occur.
4. The indications are that recovery is an effect of the progressive solvent action of the external acid on the passivating oxide film, which at its first deposition appears to be relatively thick and hence resistant to electrochemical reduction. The final stage of recovery, when electrical sensitivity and speed of transmission are maximal, would on this hypothesis correspond to minimal thickness, possibly monomolecular.
5. The rate of recovery in Bath B is not far from proportional to the concentration of HNO3 in the more dilute solutions, but in the higher, especially the strongly passivating, concentrations (70 to 100 v. per cent) the rate becomes appreciably slower than proportional, apparently because of the intense oxidizing action of these solutions, which reinforces the oxide sheet and retards the thinning process.
6. The bearing of these observations on the problem of the conditions of recovery in irritable living tissues (such as nerve) during the absolute and relative refractory periods is briefly discussed.
THE DEATH WAVE IN NITELLA
Authors: Osterhout W. J. V. , Hill S. E. 
Published: May 2004

Cutting a cell of Nitella sets up a series of rapid electrical responses, transmitted at a rate too rapid to be measured by means of our records. These are followed by slower responses whose speed falls off as the distance from the cut increases, as though they were caused by a mechanical disturbance whose intensity falls off as it travels.
The faster responses seem to be due to the motion of sap past protoplasmic surfaces which have suffered little or no alteration (they seem to be similar to the electrical changes following a blow on the end of a soft rubber tube containing Ag-AgCl electrodes). The slower responses appear to be due to alterations in the protoplasm and are usually irreversible.
ON CHROMOSOME BALANCE AS A FACTOR IN DURATION OF LIFE
Authors: Gowen John W. 
Published: May 2004

This paper presents a study of the influence of chromosome balance on duration of life in Drosophila. The balanced type of cells are shown to favor a longer life than are the unbalanced type.
Under the identical conditions of the experiment, the type females live an average of 33.1±.6 days; the type males 28.9±.8 days; the triploid females 33.1±.8 days and the sex-intergrade females 15.0±.3 days. The unbalance of the chromosomes and therefore of the genes contained within them is evidently a fundamental factor in the probable life span of the individual. The magnitude of the effect is fully on a par with that found for other factors, i.e., different Mendelian genes for constitutional vigor, etc.
It has been possible to show by a study of the various sex classifications within the sex-intergrade class that the presence or absence of ovarian or testicular tissue as such is not the primary cause of the difference in the life duration in the type males and females but that the cause is to be found deeper, sex determination and duration of life accompanying each other and resulting from the common cause, chromosome constitution.
The survival curve of the sex-intergrade groups present a limiting curve of duration of life, a constant death rate for each day of age. The curves have different rates of degeneration. To account for this fact it is necessary to assume that for these particular organisms a different organ in the two groups has assumed major significance to life due to the gene complex which causes their differentiation. Recurrent chance environmental and hereditary agents acting on organs generate the type of probability curve observed.
Triploid flies are made up of cells which are one-third larger than the cells of the type flies. It is not without significance to note that such individuals show no greater or less duration of life than do the ordinary flies when both groups have their chromosomes in balance.
THE ANALYSIS OF BIOLUMINESCENCES OF SHORT DURATION, RECORDED WITH PHOTOELECTRIC CELL AND STRING GALVANOMETER
Authors: Harvey E. Newton , Snell Peter A. 
Published: May 2004

1. The rapid decay of luminescence in extracts of the ostracod crustacean Cypridina hilgendorfii, has been studied by means of a photoelectric-amplifier-string galvanometer recording system.
2. For rapid flashes of luminescence, the decay is logarithmic if ratio of luciferin to luciferase is small; logarithmic plus an initial flash, if ratio of luciferin to luciferase is greater than five. The logarithmic plot of luminescence intensity against time is concave to time axis if ratio of luciferin to luciferase is very large.
3. The velocity constant of rapid flashes of luminescence is approximately proportional to enzyme concentration, is independent of luciferin concentration, and varies approximately inversely as the square root of the total luciferin (luciferin + oxyluciferin) concentration. For large total luciferin concentrations, the velocity constant is almost independent of the total luciferin.
4. The variation of velocity constant with total luciferin concentration (luciferin + oxyluciferin) and its independence of luciferin concentration is explained by assuming that light intensity is a measure of the luciferin molecules which become activated to oxidize (accompanied with luminescence) by adsorption on luciferase. The adsorption equilibrium is the same for luciferin and oxyluciferin and determines the velocity constant.
ELECTROKINETIC PHENOMENA
Authors: Abramson H. A. , Grossman E. B. 
Published: May 2004

1. The conditions are described which are necessary for the comparison of certain types of electrokinetic potentials. An experimental comparison is made of (a) electrophoresis of quartz particles covered with egg albumin; and (b) similar experiments by Briggs on streaming potentials. A slight, consistent, difference is found between the electrophoretic potential and the streaming potential. This difference is probably due to the difference in the protein preparations used rather than to real difference in the electrophoretic and streaming potentials.
2. Data are given which facilitate the measurements and enhance the precision of the estimation of electrical mobilities of microscopic particles.
THE FLOCCULATION OF GELATIN AT THE ISOELECTRIC POINT
Authors: Straup Danella 
Published: May 2004

The results of this investigation show that a gelatin solution consists of a considerable number of constituents. At a particular temperature, certain gelatin constituents tend to aggregate and to flocculate from solution. When these particular gelatin constituents have completely flocculated, no further change occurs in the system and an apparent equilibrium exists. This is not a dynamic equilibrium between the gelatin flocculate as a whole and the gelatin remaining in the solution but a steady state determined for that system by the temperature.
It is also shown that gelatin can be separated into fractions in which the gelatin constituents are more nearly uniform and tend to flocculate over a much narrower temperature range. It should be possible to obtain a number of fractions in which all of the gelatin would flocculate at a definite temperature. The aggregation of the various gelatin constituents is presumably due to loss of thermal energy, and the temperature at which this occurs must be some function of the mass of the constituent. It is natural to assume, then, that the constituents which flocculate at a given temperature are larger than those which remain in solution at that temperature. Recently, Krishnamurti and Svedberg (1930) have obtained evidence with the ultra-centrifuge that the constituents of a gelatin solution are heterogeneous as to mass, even at a pH value at which there is no tendency toward aggregation.
There is much reason to suppose that the gelatin constituents do not differ very greatly chemically since different fractions have the same refractive index and the same isoelectric point.
The data as a whole are best explained by considering the gelatin constituents to be different degrees of association of the same or very similar molecular structural units. This is in agreement with Sheppard and Houck (1930), who consider that "the molecules of gelatin are fundamentally identical with those of collagen, the difference being only in the degree of association and orientation". Meyer and Mark (1928) have interpreted the x-ray data obtained from collagen as indicating that the micelles of the collagen fiber are built up of main valency chains of anhydro-amino acids. It may be supposed that during peptization of these fibers, the amino acid chains become separated, disorientated, and partially broken up, so producing the heterogeneous system which we know as gelatin. It is evident that the manner in which this breaking-up proceeds depends upon the chemical treatment previous to the peptization process and the gelatin produced from lime-treated collagen would be expected to differ from that from acid-treated collagen.
From the results herein reported it seems evident that the technique of isoelectric flocculation of electrolyte-free gelatin offers a profitable method for the study of gelatin and an extended investigation along these lines should yield much valuable information concerning the nature of gelatin. It is possible that this method may also be extended to other hydrophilic colloids.
CRYSTALLINE PEPSIN
Authors: Northrop John H. 
Published: May 2004

1. Pepsin solutions which have been completely denatured and inactivated by adjusting to pH 10.5 recover some of their activity when titrated to about pH 5.4 and allowed to stand at 22°C. for 24 to 48 hours.
2. Control experiments show that this inactivation and reactivation are probably not due to the effect of any inhibiting substance.
3. A method of isolation of the reactivated material has been worked out.
4. The reactivated material recovered in this way is a protein with the same general solubility, the same crystalline form, and the same specific proteolytic activity as the original crystalline pepsin.
5. This furnishes additional proof that the proteolytic activity is a property of the protein molecule.
THE KILLING OF COLON BACILLI BY ULTRAVIOLET LIGHT
Authors: Wyckoff Ralph W. G. 
Published: May 2004

The survival ratios of colon bacilli subjected to several monochromatic ultraviolet radiations follow semilogarithmic straight lines. For each wave length approximate observations have been made of the energy involved in cell destruction. This energy varies somewhat with frequency in the ultraviolet region; it is furthermore nearly one hundred times as great as the amount of X-ray energy required to bring about the same killing.
Preliminary experiments show no measurable difference either in rate of killing or in lethal energy between B. coli and B. aertrycke. Parallel results have already been obtained with X-rays and electrons.
The data from colon bacilli are interpreted in terms of the assumptions employed for X-rays. They indicate that though bacterial death should result from a single quantum absorption, millions more such absorptions seemingly are without injurious effect on cell growth and multiplication. The "sensitive volume" within which, according to this picture, the lethal quantum must be stopped proves to be about the same as that of a single protein molecule. If this is the correct description of the phenomena of ultraviolet killing, it seems strange that the millions of non-deadly quanta absorbed per bacillus should not show themselves by altered growth rates or in other ways. That they apparently do not suggests the inapplicability of the statistical picture. The death rate under this kind of radiation then would be primarily an expression of the relative sensitivities of the bacterial population. Additional experiments are required to determine this question.
THE MOBILITY OF THE GELATINATE ION
Authors: Ferguson A. L. , Schluchter A. W. 
Published: May 2004

1. Many measurements were made with the two systems
H2/NaOH C/NaOH C + x gm. gelatin/H2
H2/NaOH C/KCl (sat.)/NaOH C + x gm. gelatin/H2
in which x was varied from zero to more than enough for complete combination.
2. From these measurements the change in boundary potential with quantity of gelatin present was determined.
3. The boundary potentials were calculated by means of a modified form of the Henderson equation.
4. The results indicate that the mobility of the gelatinate ion is about 20.
SIMILARITY OF THE KINETICS OF INVERTASE ACTION IN VIVO AND IN VITRO
Authors: Nelson J. M. , Palmer Elizabeth T. , Wilkes B. G. 
Published: May 2004

1. A method is given whereby the course of hydrolysis of sucrose by live yeast cells may be followed with precision equal to that found when invertase solutions prepared from autolyzed yeast are used to cause inversion.
2. The practical value of the equation of Nelson and Hitchcock as a means of following the course of enzymic hydrolysis of sucrose is hereby extended.
3. The inversion of sucrose by live yeast cells and by extracted invertase has been quantitatively compared.
4. The course of hydrolysis of sucrose by the invertase of Fleischmann's yeast has been found to be identical in vivo and in vitro.
STIMULATION BY HYDROCHLORIC ACID AND BY THE NORMAL ALIPHATIC ACIDS IN THE SUNFISH EUPOMOTIS
Authors: Allison James B. 
Published: May 2004

1. The reaction of the sunfish, Eupomotis gibbosus, to different concentrations of hydrochloric acid and of the first six members of the N aliphatic acids has been studied.
2. The stimulating efficiency of hydrochloric acid may best be related to the concentration of hydrogen ions produced by that acid.
3. The stimulating efficiency of the N aliphatic acids may best be correlated with the non-polar nature of a portion of the molecule, but it is necessary to consider the higher potential of the polar group of formic acid to account satisfactorily for its position in the series.
4. When equally effective concentrations of the N aliphatic acids are compared, formic acid is more effective at lower concentrations than at higher.
5. Per cent variation in response appears to be independent of the chemical environment to which the animal responded.
ELECTRIC PHASE ANGLE OF CELL MEMBRANES
Authors: Cole Kenneth S. 
Published: May 2004

From the theory of an electric network containing any combination of resistances and a single variable impedance element having a constant phase angle independent of frequency, it is shown that the graph of the terminal series reactance against the resistance is an arc of a circle with the position of the center depending upon the phase angle of the variable element.
If it be assumed that biological systems are equivalent to such a network, the hypotheses are supported at low and intermediate frequencies by data on red blood cells, muscle, nerve, and potato. For some tissues there is a marked divergence from the circle at high frequencies, which is not interpreted.
THE ACCUMULATION OF ELECTROLYTES
Authors: Osterhout W. J. V. , Stanley W. M. 
Published: May 2004

Inasmuch as attempts to explain accumulation by the Donnan principle have failed in the case of Valonia, a hypothesis of the steady state has been formulated to explain what occurs. In order to see whether this hypothesis is in harmony with physico-chemical laws attempts have been made to imitate its chief features by means of a model.
The model consists of a non-aqueous layer (representing the protoplasmic surface) placed between an alkaline aqueous phase (representing the external solution) and a more acid aqueous phase (representing the cell sap).
The model reproduces most of the features of the hypothesis. Attention may be called to the following points.
1. The semipermeable surface is a continuous non-aqueous phase.
2. Potassium penetrates by combining with an acid HX in the non-aqueous layer to form KX which in turn reacts with an acid HA in the sap to form KA. Since KX is little dissociated in the non-aqueous layer potassium appears to pass through it chiefly in molecular form.
3. The internal composition depends on permeability, e.g., sodium penetrates less rapidly than potassium and in consequence potassium predominates over sodium in the "artificial sap." The order of penetration in the model is the same as in Valonia, i.e., K &gt; Na &gt; Ca &gt; Mg, and Cl &gt; SO4, but the quantitative resemblance is not close, e.g., the difference between potassium and sodium, and chloride and sulfate is much less in the model.
4. The formation of KA and NaA in the sap raises its osmotic pressure and water enters.
5. The concentration of potassium and sodium and the osmotic pressure become much greater inside than outside. For example, potassium may become 200 times as concentrated inside as outside.
6. No equilibrium occurs but a steady state is reached in which water and salt enter at the same rate so that the composition of the sap remains constant as its volume increases.
7. Since no equilibrium occurs there is a difference of thermodynamic potential between inside and outside. At the start the thermodynamic potential of KOH is much greater outside than inside. This difference gradually diminishes and in the steady state has about the same value as in Valonia. The difference in pH value between the internal and external solutions is also similar in both cases (about 2 pH units).
8. Accumulation does not depend on the presence of molecules or ions inside which are unable to pass out.
One important feature of the hypothesis is not seen in the model: this is the exchange of HCO3 for Cl-. Experiments on this point are in progress.
THE OXYGEN CONSUMPTION OF ESCHERICHIA COLI DURING THE LAG AND LOGARITHMIC PHASES OF GROWTH
Authors: Martin Donald S. 
Published: May 2004

The oxygen consumption of rapidly growing cultures of Esch. coli (S) have been measured by means of Fenn's respirometer.
The rate of oxygen consumption of a growing culture uniformly attains a phase of logarithmic increase before the growth curve of the organisms becomes logarithmic.
The rate of oxygen consumption per cell increases rapidly from the time of inoculation to a point of maximum respiration near the end of the lag phase of the growth curve, followed by a gradual decrease in the respiratory rate.
The surface area of the average cell when plotted against time passes through a point of maximum surface area which coincides with the point of maximum oxygen consumption per cell.
Figures obtained by different methods, CO2 output and heat production when reduced to the same units, agree remarkably well.