bluuebunny/crossref_metadata_2025_split huggingface dataset:
ON THE RELATION BETWEEN TOXICITY, RESISTANCE, AND TIME OF SURVIVAL, AND ON RELATED PHENOMENA
Authors: Reiner L. 
Published: May 2004

1. A relation between toxicity, resistance, and time of survival has been derived on the basis of the assumption that the time is a function of a parameter which is the difference between the toxicity and the resistance. Toxicity and resistance act like forces which can maintain an equilibrium-like (or stationary) state. If the equilibrium is upset, the time at which the event (death) occurs is proportional to the logarithm of the difference between toxicity and resistance.
2. It was found that if values proportional to the resistance are calculated with the proposed equation and the percentage mortality plotted against them (instead of against the time as is usual) symmetrical curves are obtained even though the corresponding mortality-time curves are asymmetrical. Assuming that the resistance varies like an error, that is, according to probability rules, theoretical mortality-time curves, similar to the experimental curves, can be constructed from the proposed equations.
3. In the case of a toxic agent acting on a unicellular organism suspended in solution, the toxicity is proportional to the adsorbed amount of the agent, as calculated with the aid of the Langmuir equation. In small concentration ranges the toxicity can be taken as approximately proportional to the concentration.
4. The variation of the temperature affects mainly the constant a which is a function of the temperature similar to that of the velocity constant of a chemical reaction (Arrhenius' law).
5. The proposed equation has been tested in four different combinations of the variables, concentration, resistance, time, and temperature. The agreement with the experiments is satisfactory.
6. Any noxious agent acting on a unicellular organism may be characterized by three constants: r, the resistance, which is the threshold value at which the agent is still fatally toxic for the organism; a, the reciprocal of the rate constant determining the specific rate (that is, the time corresponding to a difference of 1 between the toxicity and the resistance); and finally the constant γ of the function representing the relation between toxicity and concentration.
THE KINETICS OF PENETRATION
Authors: Osterhout W. J. V. , Kamerling S. E. , Stanley W. M. 
Published: May 2004

Some of the factors affecting penetration in living cells may be advantageously studied in models in which the organic salts KG and NaG diffuse from an aqueous solution A, through a non-aqueous layer B (representing the protoplasmic surface) into an aqueous solution C (representing the sap and hence called artificial sap) where they react with CO2 to form KHCO3 and NaHCO3. Their relative proportions in C depend chiefly on the partition coefficients and on the diffusion constants in the non-aqueous layer. But the ratio is also affected by other variables, among which are the following:
1. Temperature, affecting diffusion constants and partition coefficients and altering the thickness of the unstirred layers by changing viscosity.
2. Viscosity (especially in the non-aqueous layers) which depends on temperature and the presence of solutes.
3. Rate of stirring, which affects the thickness of the unstirred layers and the transport of electrolyte in those that are stirred.
4. Shape and surface area of the non-aqueous layer.
5. Surface forces.
6. Reactions occurring at the outer surface such as loss of water by the electrolyte or its molecular association in the non-aqueous phase. The reverse processes will occur at the inner surface and here also combinations with acids or other substances in the "artificial sap" may occur.
7. Outward diffusion from the artificial sap. The outward movement of KHCO3 and NaHCO3 is small compared with the inward movement of KG and NaG when the concentrations are equal. This is because the partition coefficients3 of the bicarbonates are very low as compared with those of NaG and KG.
Since CO2 and HCO3- diffuse into A and combine with KG and NaG the inward movement of potassium and sodium falls off in proportion as the concentration of KG and NaG is lessened.
8. Movement of water into the non-aqueous phase and into the artificial sap. This may have a higher temperature coefficient than the penetration of electrolytes.
9. Variation of the partition coefficients with concentration and pH.
Many of these variables may occur in living cells. (It happens that the range of variation in the ratio of potassium to sodium in the models resembles that found in Valonia.)
KINETICS OF PENETRATION
Authors: Osterhout W. J. V. , Kamerling S. E. , Stanley W. M. 
Published: May 2004

In some living cells the order of penetration of certain cations corresponds to that of their mobilities in water. This has led to the idea that electrolytes pass chiefly as ions through the protoplasmic surface in which the order of ionic mobilities is supposed to correspond to that found in water.
If this correspondence could be demonstrated it would not prove that electrolytes pass chiefly as ions through the protoplasmic surface for such a correspondence could exist if the movement were mostly in molecular form.
This is clearly shown in the models here described. In these the protoplasmic surface is represented by a non-aqueous layer interposed between two aqueous phases, one representing the external solution, the other the cell sap.
The order of penetration through the non-aqueous layer is
Cs &gt; Rb &gt; K &gt; Na &gt; Li.
This will be recognized as the order of ionic mobilities in water. Nevertheless the movement is mostly in molecular form in the nonaqueous layer (which is used in the model to represent the protoplasmic surface) since the salts are very weak electrolytes in this layer.
The chief reason for this order of penetration lies in the fact that the partition coefficients exhibit the same order, that of cesium being greatest and that of lithium smallest.
The partition coefficients largely control the rate of entrance since they determine the concentration gradient in the non-aqueous layer which in turn controls the process of penetration. The relative molecular mobilities (diffusion constants) in the non-aqueous layer do not differ greatly. The ionic mobilities are not known (except for K+ and Na+) but they are of negligible importance, since the movement in the non-aqueous layer is largely in molecular form. They may follow the same order as in water, in accordance with Walden's rule.
Ammonium appears to enter faster than its partition coefficient would lead us to expect, which may be due to rapid penetration of NH3. This recalls the apparent rapid penetration of ammonium in living cells which has also been explained as due to the rapid penetration of NH3.
Both observation and calculation indicate that the rate of penetration is not directly proportional to the partition coefficient but increases somewhat less rapidly.
Many of these considerations doubtless apply to living cells.
BLAIR'S "CONDENSER THEORY" OF NERVE EXCITATION
Authors: Rushton W. A. H. 
Published: May 2004

Blair's recent theory of excitation is analysed with the following conclusions:
1. The theory is inapplicable to currents of long duration; i.e., slowly increasing currents and the opening excitation.
2. The theory is a modification of the condenser theory of excitation but the modification is to be rejected on three grounds:
(a) The modification has no obvious physical significance.
(b) It does not in fact remedy the divergence between calculation and observation.
(c) It leads to certain conclusions of a surprising kind which are contrary to observed fact.
3. The qualitative value of the condenser theory is demonstrated by the fairly close agreement between calculation and observation over a considerable field of enquiry.
INACTIVATION OF CRYSTALLINE TRYPSIN
Authors: Kunitz M. , Northrop John H. 
Published: May 2004

1. The rate of inactivation of crystalline trypsin solutions and the nature of the products formed during the inactivation at various pH at temperatures below 37°C. have been studied.
2. The inactivation may be reversible or irreversible. Reversible inactivation is accompanied by the formation of reversibly denatured protein. This denatured protein exists in equilibrium with the native active protein and the equilibrium is shifted towards the denatured form by raising the temperature or by increasing the alkalinity. The decrease in the fraction of active enzyme present (due to the formation of this reversibly denatured protein) as the pH is increased from 8.0 to 12.0 accounts for the decrease in the rate of digestion of proteins by trypsin in this range of pH.
3. The loss of activity at high temperatures or in alkaline solutions, just described, is very rapid and is completely reversible for a short time only. If the solutions are allowed to stand the loss in activity becomes gradually irreversible and is accompanied by the appearance of various reaction products the nature of which depends upon the temperature and pH of the solution.
4. On the acid side of pH 2.0 the trypsin protein is changed to an inactive form which is irreversibly denatured by heat. The course of the reaction in this range is monomolecular and its velocity increases as the acidity increases.
5. From pH 2.0 to 9.0 trypsin protein is slowly hydrolyzed. The course of the inactivation in this range of pH is bimolecular and its velocity increases as the alkalinity increases to pH 10.0 and then decreases. As a result of these two reactions there is a point of maximum stability at about pH 2.3.
6. On the alkaline side of pH 13.0 the reaction is similar to that in strong acid solution and consists in the formation of inactive protein. The course of the reaction is monomolecular and the velocity increases with increasing alkalinity. From pH 9.0 to 12.0 some hydrolysis takes place and some inactive protein is formed and the course of the reaction is represented by the sum of a bi- and monomolecular reaction. The rate of hydrolysis decreases as the solution becomes more alkaline than pH 10.0 while the rate of formation of inactive protein increases so that there is a second point at about pH 13.0 at which the rate of inactivation is a minimum. In general the decrease in activity under all these conditions is proportional to the decrease in the concentration of the trypsin protein. Equations have been derived which agree quantitatively with the various inactivation experiments.
STIMULATION OF FUNDULUS BY HYDROCHLORIC AND FATTY ACIDS IN FRESH WATER, AND BY FATTY ACIDS, MINERAL ACIDS, AND THE SODIUM SALTS OF MINERAL ACIDS IN SEA WATER
Authors: Allison J. B. , Cole William H. 
Published: May 2004

1. Fundulus heteroclitus was found to be a reliable experimental animal for studies on chemical stimulation in either fresh or sea water.
2. The response of Fundulus to hydrochloric, acetic, propionic, butyric, valeric, and caproic acids was determined in fresh water, while the same acids plus sulfuric and nitric, as well as the sodium salts of the mineral acids, were tested in sea water.
3. Stimulation of Fundulus by hydrochloric acid in fresh water is correlated with the effective hydrogen ion concentration. Stimulation by the n-aliphatic acids in the same environment is correlated with two factors, the effective hydrogen ion concentration and the potential of the non-polar group in the molecule. However, as the number of CH2 groups increases the stimulating effect increases by smaller and smaller amounts, approaching a maximum value.
4. Stimulation of Fundulus by hydrochloric, sulfuric, and nitric acids in sea water is correlated with the forces of primary valence which in turn are correlated with the change in hydrogen ion concentration of the sea water. The n-aliphatic acids increase in stimulating efficiency in sea water as the length of the carbon chain increases, but a limiting value is not reached as soon as in fresh water.
5. Only a slight difference in stimulation by hydrochloric acid is found in sea water and in fresh water. However, there is a significant difference in stimulation by the fatty acids in fresh and in sea water, which is partly explained by the different buffering capacities of the two media. It is to be noted that in the same environment two different fish, Fundulus and Eupomotis, give different results, while the same fish (Fundulus) in two different environments responds similarly to mineral acids but differently to fatty acids. These results illustrate that stimulation is a function of the interaction between environment and receptors, and that each is important in determining the response.
6. Stimulation by sodium chloride, nitrate, and sulfate is correlated with equivalent concentrations of the salts added to sea water, or with the forces of primary valence. Although the threshold for stimulation by the salts is considerably higher than for the acids, the efficiency of stimulation by the salts is greater.
MANOMETRIC MEASUREMENTS OF PHOTOSYNTHESIS IN THE MARINE ALGA GIGARTINA
Authors: Emerson Robert , Green Lowell 
Published: May 2004

A manometric method for measuring photosynthesis in marine algae is described.
Photosynthesis in the red alga Gigartina harveyana is shown to be similar in all important respects to photosynthesis in Chlorella and other Chlorophyceae.
ELECTRICAL CONTROL OF RHIZOID FORMATION IN THE RED ALGA, GRIFFITHSIA BORNETIANA
Authors: Schechter Victor 
Published: May 2004

1. Direct galvanic current of 10 to 40 microamperes per square millimeter of cross-section of medium results in anodal determination of rhizoid origin in the differentiated cells of the red alga Griffithsia bornetiana. The current is most effective near the upper end of the range.
2. Within the range used there is an increase in the number of rhizoids produced with increase in current intensity and a decrease in size of rhizoids.
3. Currents of lower intensity require a longer time to produce these effects than comparatively high currents.
4. The orientation of the plants in the electrical field seems to affect the number of rhizoids produced, in that plants with apexes toward the anode produce more rhizoids.
5. Together with anodal rhizoid determination there is migration of chromatophores toward the anodal side of each cell.
6. Displacement of chromatophores (and other cytoplasmic bodies) by the centrifuge does not affect the point of rhizoid origin, but does affect the shoots.
7. Together with anodal determination of rhizoids the algal filaments become graded in color, from bright pink toward the cathode to pale tan toward the anode.
8. Evidence is presented to show that this is not due to a pH change, but to a loss of pigment by chromatophores toward the anode and electrophoresis of the pigment toward the cathode.
9. In conclusion the probability is pointed out that the current acts in morphogenesis by moving particles of different charge.
STUDIES ON THE GROWTH HORMONE OF PLANTS
Authors: Thimann Kenneth V. 
Published: May 2004

1. It is shown that when plant tissues are ground with water the growth substance contained therein is inactivated by the oxidizing enzymes.
2. A simple method of extraction is described which enables the quantitative determination of growth substance in such tissues.
3. The amount and distribution of growth substance in the Avena coleoptile is determined by this method, and it is shown that while the substance does not diffuse out from the lower parts of the coleoptile, it is nevertheless present in considerable amounts, the concentration decreasing steadily with the distance from the tip.
4. Growth substance is also present in considerable amounts in Avena roots, and here also its concentration decreases steadily with distance from the tip.
5. The amount of growth substance diffusing out of root tips into dextrose agar, even during long periods of time, is not greater than the amount obtainable by direct extraction. Actual production in the root tip therefore either does not take place at all, or else takes place under quite different conditions from the production in the tip of the coleoptile.
ELECTRICAL RESPONSES FROM THE LATERAL-LINE NERVES OF FISHES
Authors: Hoagland Hudson 
Published: May 2004

Records of spontaneous discharge of nerve impulses, similar to that previously described in catfish and in trout, have been obtained from lateral-line nerves of goldfish and perch, by the use of concentric micro electrodes slipped under the nerve in situ. These impulses have been followed into the central nervous system. They enter the tuberculum acusticum and thence apparently spread diffusely through the cerebellum. Cutting the lateral-line nerve on one side silences the ipsilateral tuberculum acusticum, but only reduces the intensity of ipsilateral cerebellar activity. Cutting the remaining lateral-line nerve silences activity throughout the tuberculum acusticum and the cerebellum.
The maintenance of tonic activity in the tuberculum acusticum by way of lateral-line discharge may account for the inhibitory effects of the lateral-line system on auditory responses.
RESULTS OF IRRADIATING SACCHAROMYCES WITH MONOCHROMATIC ULTRA-VIOLET LIGHT
Authors: Oster Robert H. 
Published: May 2004

Possible variation in the probability that absorbed quanta of ultra-violet energy will produce observable inhibitory and lethal effects in the yeast cell, due to non-uniformity in sensitivity of the different regions of the cell, may be further modified by the reproductive stage of the cell at the time of irradiation. Tests of the survival of yeast cells of 15 day and 24 hour cultures indicate that the older resting cells are more resistant to ultra-violet irradiation effects than cells undergoing rapid cell division.
The effects of temperature changes within the range of normal growth are evidently small, as judged from the temperature coefficient (1.10).
Possible inhibitory effects due to the action of ultra-violet radiation on the malt agar medium and to toxic substances diffused from cells killed by irradiation were not found under the conditions of the experiments.
Tests of the validity of the Bunsen-Roscoe reciprocity law for variation in the intensity of the incident ultra-violet radiation up to 30 per cent indicate that for this range the rate of absorption of quanta by the cell does not produce any marked change in the lethal effects observed.
THE ACCUMULATION OF ELECTROLYTES
Authors: Jacques A. G. 
Published: May 2004

Analyses have been made of the inorganic constituents of the juices expressed from the leaves of Rheum, Rumex, and Oxalis.
It has been shown that in all cases there is a large excess of inorganic cations over anions in the sap, the average ratio of cations to anions being 3.8 (Part 1, p. 239).
The ash analyses of plant tissues (chiefly leaves) reported in the literature have been examined critically, and it has been shown that the preponderance of inorganic cations over inorganic anions in the ash and in the sap is general.
It has been concluded that the excess of inorganic cations is consistent with the view that cations pass into the protoplasm chiefly in the form of hydroxides, and are accumulated either in the form of organic salts (such as the oxalates) or in non-polar linkage.
It has been concluded that practically all the potassium and sodium found in plant ash must have been present originally in the form of soluble ionogenic compounds, but that a considerable part of the calcium and magnesium may have been present originally in the form of insoluble salts or as components of non-polar compounds.
The methods whereby the cations, particularly potassium, may have been accumulated have been discussed, and it has been concluded that as it does not seem very probable that they enter chiefly as nitrates or bicarbonates we may suppose that they go in to a large extent as hydrates: this is highly probable in the case which has been most carefully investigated (Valonia).
SULFHYDRYL AND DISULFIDE GROUPS OF PROTEINS
Authors: Mirsky A. E. , Anson M. L. 
Published: May 2004

1. Methods have been described for reducing protein S-S groups, for oxidizing protein SH groups, and for estimating protein S-S and SH groups.
2. It has been found necessary in estimating the cystine content of proteins by the Folin-Marenzi method to take into account any cysteine that may be present.
3. A method for estimating the cysteine content of proteins has been described.
4. With these methods, estimations have been made of the S-S and SH groups and of the cystine and cysteine contents of a number of proteins.
5. In a denatured, but unhydrolyzed protein, the number of S-S and SH groups is equivalent to the quantity of cystine and cysteine found in the protein after hydrolysis.
PRODUCTS OF THE OXIDATION OF THIOSULFATE BY BACTERIA IN MINERAL MEDIA
Authors: Starkey Robert L. 
Published: May 2004

Various cultures (previously described), which oxidize thiosulfate in mineral media have been studied in an attempt to determine the products of oxidation. The transformation of sodium thiosulfate by Cultures B, T, and K yields sodium tetrathionate and sodium hydroxide; secondary chemical reactions result in the accumulation of some tri- and pentathionates, sulfate, and elemental sulfur. As a result of the initial reaction, the pH increases; the secondary reactions cause a drop in pH after this initial rise. The primary reaction yields much less energy than the reactions effected by autotrophic bacteria. No significant amounts of assimilated organic carbon were detected in media supporting representatives of these cultures. It is concluded that they are heterotrophic bacteria.
Th. novellus oxidizes sodium thiosulfate to sodium sulfate and sulfuric acid; the pH drops progressively with growth and oxidation. Carbon assimilation typical of autotrophic bacteria was detected; the ratio of sulfate-sulfur formed to carbon assimilated was 56:1. It is calculated that 5.1 per cent of the energy yielded by the oxidation of thiosulfate is accounted for in the organic cell substance synthesized from inorganic materials. This organism is a facultative autotroph.
The products of oxidation of sodium thiosulfate by Th. thioparus are sodium sulfate, sulfuric acid, and elemental sulfur; the ratio of sulfate sulfur to elemental sulfur is 3 to 2. The pH decreases during growth and oxidation. The elemental sulfur is produced by the primary reaction and is not a product of secondary chemical changes. The bacterium synthesizes organic compounds from mineral substances during growth. The ratio of thiosulfate-sulfur oxidized to carbon assimilated was 125:1, with 4.7 per cent of the energy of oxidation recovered as organic cell substance. This bacterium is a strict autotroph.
NATURE OF THE ACTION CURRENT IN NITELLA
Authors: Osterhout W. J. V. , Hill S. E. 
Published: May 2004

Several forms of the action curve are described which might be accounted for on the ground that the outer protoplasmic surface shows no rapid electrical change. This may be due to the fact that the longitudinal flow of the outgoing current of action is in the protoplasm instead of in the cellulose wall. Hence the action curve has a short period with a single peak which does not reach zero.
On this basis we can estimate the P.D. across the inner and outer protoplasmic surfaces separately. These P.D.'s can vary independently.
In many cases there are successive action currents with incomplete recovery (with an increase or decrease or no change of magnitude).
Some of the records resemble those obtained with nerve (including bursts of action currents and after-positivity).