bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE KINETICS OF STARVATION
Authors: Wetzel Norman C. 
Published: May 2004

1. The loss of weight in pigeons subjected to prolonged starvation on water alone may be accurately represented by an appropriate form of the law of autocatakinesis.
2. This function, within proper limitations, gives a definite indication as to the nature and character of the fundamental reactions involved. In addition, it provides quantitative measures of the relative progress and importance of these reactions.
3. Analytically, the process of starvation consists of two nearly symmetrical cycles, corresponding chemically to the destruction of the carbohydrate-fat reserves and to the decomposition of body protein.
4. A suitable transformation overcoming certain difficulties inherent in the general form of the law is discussed and applied to the data reported.
DIURNAL CHANGES IN THE ACIDITY OF BRYOPHYLLUM CALYCINUM
Authors: Gustafson Felix G. 
Published: May 2004

1. It has been shown that there is a diurnal change in the H ion concentration in Bryophyllum calycinum corresponding approximately to the total acidity changes. The H ion concentration increases at night and decreases during the day.
2. Light is the main factor in causing the decrease in acidity, though it also occurs in the dark. but much more slowly.
3. External oxygen tension does not seem to influence the acidity of the plant, nor does it influence the decomposition of the extracted juice.
STUDIES ON LUMINOUS BACTERIA
Authors: Morrison Thomas F. 
Published: May 2004

1. A method has been described whereby the intensity of the light of luminous bacteria may be measured in a quantitative manner.
2. It is pointed out that the temperature coefficients for light intensity do not follow the van't Hoff rule, but are higher and vary with each 10° temperature interval.
3. From a comparison with other data it is found that the process is not a simple one, but that the observed curve is the resultant of several reactions which proceed simultaneously.
4. The discrepancies in the temperature coefficients in the neighborhood of the "optimum temperature" may be due to a process of coagulation of the colloidal particles of the enzyme. This coagulation will tend to cause a deviation of the curve away from that normal for chemical reactions.
ON THE ACCUMULATION OF DYE IN NITELLA
Authors: Irwin Marian 
Published: May 2004

Living cells of Nitella were placed in different concentrations of brilliant cresyl blue solutions at pH 6.9. It was found that the greater the concentration of the external dye solution, the greater was the speed of accumulation of the dye in the cell sap and higher was the concentration of dye found in the sap at equilibrium.
Analysis of the time curves showed that the process may be regarded as a reversible pseudounimolecular reaction.
When the concentration in the sap is plotted as ordinates and the concentration in the outside solution as abscissae the curve is convex toward the abscissae. There is reason to believe that secondary changes involving injury take place as the dye accumulates and that if these changes did not occur the curve would be concave toward the abscissae.
The process may be explained as a chemical combination of the dye with a constituent of the cell. This harmonizes with the fact that the temperature coefficient is high (about 4.9). Various other possible explanations are discussed.
THE EXCRETION OF CARBON DIOXIDE BY FROG NERVE
Authors: Parker G. H. 
Published: May 2004

1. Quiescent sciatic nerve of the frog discharges CO2 at the average rate of 0.00876 mg. CO2 per gram of nerve per minute.
2. Sciatic nerve steeped one minute in boiling water discharges CO2 at first at a low rate and after an hour and a half not at all.
3. Degenerated sciatic nerve discharges CO2 at a slightly higher rate than normal living nerve does.
4. Connective tissue from the frog discharges CO2 at an average rate of 0.0097 mg. per gram of tissue per minute.
5. Assuming that a nerve is composed of from one-half to one-quarter connective tissue the CO2 output from its strictly nervous components is estimated to be at a rate of 0.008 mg. CO2 per gram of nerve per minute.
6. Stimulated sciatic nerve increases the rate of its CO2 output over quiescent nerve by about 14 per cent. When this number is corrected for strictly nervous tissue the rate is about 16 per cent.
7. The increased rate of CO2 production noted on stimulation in normal sciatic nerves was not observed when they were boiled, blocked, or degenerated. It was also not observed with stimulated strands of connective tissue.
CONTRIBUTION TO THE THEORY OF PERMEABILITY OF MEMBRANES FOR ELECTROLYTES
Authors: Michaelis L. 
Published: May 2004

From experiments on such membranes as apple skin, parchment paper membrane, and a membrane of completely dry collodion, results have been obtained which could be interpreted by the assumption that these membranes are less permeable for anions than for cations. In parchment paper there is only a relative diminution of the mobility of the anions, in the apple skin and in the dry collodion membrane there is practically no permeability for anions at all. The theory is developed which explains how the decrease or complete lack of mobility of anions influences the electromotive effects of the membrane and the diffusibility of electrolytes across a membrane. The results of the theory are compared with the experimental results.
In membranes impermeable for anions the permeability for cations gives the same order of cations as for the mobilities in a free aqueous solution. But the differences of the mobilities are enormously magnified, e.g. the mobilities of H• and Li•, which are in the proportion of about 1:10 in aqueous solution, are in proportion of about 1:900 in the collodion membrane. The general cause for the retardation of ionic mobility within the membrane may be supposed to be the increased friction of the water envelope dragged along by the ion in the capillary canals of the membrane. The difference of the effect on the cations and on the anions may be attributed to the electric charge of the walls of the canals.
STUDIES ON THE FORMATION AND IONIZATION OF THE COMPOUNDS OF CASEIN WITH ALKALI
Authors: Greenberg David M. , Schmidt Carl L. A. 
Published: May 2004

1. Data from the results of transference experiments on solutions of the alkaline earth caseinates are given.
2. The data support the idea that part of the alkaline earth element is held by the casein in the form of complex ions.
3. Grounds are given for believing that the complex anions have a definite composition.
A STUDY OF THE CIRCULATION, BLOOD PRESSURE, AND RESPIRATION OF SHARKS
Authors: Lyon E. P. 
Published: May 2004

The average branchial blood pressure in sand sharks was 32 mm. of mercury. The highest recorded in a resting animal was 43 mm. The average dorsal or systemic pressure was 23.3 mm.; highest 30 mm. The ratio of branchial to systemic pressure is about 3 to 2.
The pressure in both systems keeps up well under trauma; but under experimental conditions, with or without manipulation of viscera, slowly falls after several hours.
It rises with muscular effort, and a long rise usually follows stoppage of struggling. It rises when sodium carbonate is injected. The adrenalin curve resembles that in a mammal. Spontaneous rises and falls not attributable to the heart occur. Light in some animals increases blood pressure. It is suspected that these fishes have a vasomotor apparatus.
The heart rate except after trauma is practically always the same as the respiration rate, and there is some reason for believing that the heart rate is determined by the respiration rate. When not in step with respiration, the heart is slower and often in a simple ratio with respiration.
The heart is inhibited by all sorts of stimuli applied practically anywhere (except to the liver?). This effect is abolished by atropin.
Respiration is faster in small animals and averages 24 per minute. Respiration slowly decreases in strength with little change in rate. Usually respiration ceases long before the heart stops.
THE ANALYSIS OF THE GROWTH OF THE NORMAL WHITE MOUSE INTO ITS CONSTITUENT PROCESSES
Authors: Robertson T. Brailsford 
Published: May 2004

1. The several growth-cycles which are distinguishable in the growth of an animal or plant are mutually independent in that they do not share a common catalyser.
2. The growth of the white mouse has been shown to consist of three autocatalytic processes and one "linear process" of weight-accretion. The parameters of these processes have been evaluated for one strain and generation of mice.
3. The first and most extensive autocatalytic process is asymmetrical, being defined by an equation of the type:
See PDF for Equation
The second and third cycles, which are more rapid and do not begin to affect the growth of the animal until a later stage of development, are symmetrical, being defined by equations of the type:
See PDF for Equation
4. The amplitude of the first autocatalytic growth-cycle in the mouse is almost the same in males and females, but the moment of maximum growth-velocity in the female anticipates that in the male, the velocity constant is smaller in the female, and the asymmetry estimated by the magnitude of the constant B, is greater in the female than in the male.
5. The amplitude of the second cycle is almost the same in males and females, but data are as yet lacking which would enable us to ascertain whether the velocity-constant and moments of maximum growth-velocity in this cycle differ in the two sexes or not.
6. The amplitude of the third cycle is much less in the female than in the male, and this difference of amplitude almost wholly accounts for the difference of adult weight in the two sexes. The velocity-constant of the third cycle is, however, greater in the female than in the male. Maximum growth velocity due to this cycle is attained at very nearly the same age in both sexes.
7. The origin of asymmetry in autocatalytic growth-processes is discussed. It is pointed out that asymmetry might originate in a progressive diminution of the velocity-constant. If this is the origin of the asymmetry of the first growth-cycle in the mouse, then it is shown that the velocity constant of autocatalysis in this cycle must be very nearly proportional to the nucleo-cytoplasmic ratio, as estimated by the chemical method of Le Breton and Schaeffer.
8. It is pointed out that no reliable measure of senescent loss of weight is available at present. It is shown that removal or decay of those conditions which initially maintain the separability of the growth-cycles which collectively constitute the growth of the white mouse would necessarily result in loss of weight.
THE REACTIONS OF CERIANTHUS TO LIGHT
Authors: Moore Mary Mitchell 
Published: May 2004

1. When Cerianthus membranaceus is illuminated upon one side, the animal turns its anterior portion toward the source of light. The number of degrees through which the animal turns is proportional to the logarithm of the intensity of the light.
2. A light intensity of between 250 m.c. and 15,000 m.c. is necessary to cause retraction of the animal.
3. The part of the spectrum which is most effective in causing heliotropic bending of Cerianthus lies between µµ 510 and µµ 570.
THE INFLUENCE OF THE BACKWARD REACTION IN THE PEPTIC HYDROLYSIS OF ALBUMIN
Authors: Morrell Clarence A. , Borsook Henry , Wasteneys Hardolph 
Published: May 2004

1. No destruction of pepsin by heat is demonstrable at pH 1.6 until a temperature of 40°C. is exceeded.
2. The influence of the backward reaction in peptic hydrolysis is shown in the diminishing rate at which increasing concentrations of protein are hydrolyzed.
3. The backward reaction causes the optimum for the hydrolysis of higher concentrations of protein to be attained at a lower temperature than with more dilute solutions.
4. The proteose and peptone associated with commercial pepsin retard hydrolysis in the same sense as the products due to the action of the enzyme.
STUDIES IN THE PHYSICAL CHEMISTRY OF THE PROTEINS
Authors: Cohn Edwin J. , Prentiss Adela M. 
Published: May 2004

1. The solvent action of a neutral salt upon a protein, oxyhemoglobin, has been found identical to the solvent action of a neutral salt upon a bi-bivalent or uni-quadrivalent compound.
2. The solubility of oxyhemoglobin in phosphate solutions of varying ionic strength has been defined by the equation: log
See PDF for Equation
in which µ is the ionic strength, and S0 is the solubility in the absence of salt.
3. The values of S0 have been calculated to be 12.2, 11.2, and 13.1 gm. per liter respectively at pH 6.4, 6.6, and 6.8.
4. The relatively great solubility of oxyhemoglobin in water has been ascribed to the strong affinity constants for acid and base of certain groups in oxyhemoglobin.
5. The small change in the solubility of oxyhemoglobin effected by neutral salts suggests that but few such groups are dissociated in oxyhemoglobin in the state in which it crystallizes near its isoelectric point.
6. Certain of the other properties of oxyhemoglobin, such as its low viscosity, are considered in the light of its molecular weight and its valence type.
THE ORIENTATION OF ANIMALS BY OPPOSED BEAMS OF LIGHT
Authors: Crozier W. J. 
Published: May 2004

When orientation is attained under the influence of beams of parallel light opposed at 180° the deflection θ from a path at right angles to the beams is given by tan
See PDF for Equation,
where I1 and I2 are the photic intensities and H is the average angle between the photoreceptive surfaces. This expression is independent of the units in which I is measured, and holds whether the primary photosensory effect is proportional to I or to log I. When photokinetic side-to-side motions of the head occur, H decreases with increasing total acting light intensity, but increases if higher total light intensity restricts the amplitude of random movements; in each case, H is very nearly proportional to log I1I2.
For beams of light at 90°,
See PDF for Equation.
The application of these equations to some particular instances is discussed, and it is shown why certain simpler empirical formulæ previously found by others yield fair concordance with the experimental data. The result is thus in complete accord with the tropism theory, since the equations are based simply on the assumption that when orientation is attained photic excitation is the same on the two sides.
PHYSIOLOGICAL ONTOGENY
Authors: Murray Henry A. 
Published: May 2004

1. The average weights of chicken embryos between 5 and 19 days of incubation as found by over 600 weighings may be expressed by a simple exponential equation,
W = K t3.6
where K = 0.668.
2. The velocity of growth (i.e. the percentage increase in mass) is inversely proportional to the incubation age. The product of the two (vt) is a constant (3.6). The negative acceleration of growth likewise decreases with age.
ELECTROENDOSMOSIS THROUGH MAMMALIAN SEROUS MEMBRANES
Authors: Mudd Stuart 
Published: May 2004

The hydrogen ion reversal points of human, dog, and cat serous membranes have been determined with acetic acid-sodium acetate buffer mixtures, and are compared with the reversal points of the same membranes estimated with citrate-phosphate mixtures. The values with acetate buffer are about one-quarter of a pH unit higher (more alkaline) for fat membranes and almost one-half a pH unit higher for lean membranes. The acetate values are believed to correspond more closely to the true hydrogen ion reversal points.
The reversal points are again found to be characteristic for membrane and species. No evidence of a postmortem shift in reversal point has been found. The charge of the membranes even in the living animal is capable of ready and repeated reversal.
THE INACTIVATION OF TRYPSIN BY X-RAYS
Authors: Clark Harry , Northrop John H. 
Published: May 2004

1. The inactivating effect of soft x-rays on trypsin in solutions of various degrees of concentration has been studied.
2. It has been found to run parallel with spontaneous heat inactivation. It is almost, if not entirely, confined to the free or active trypsin.
3. Under radiation of constant intensity, the inactivation follows the simple exponential law which indicates a monomolecular reaction.
4. Estimates have been made of the amount of ionization required to inactivate trypsin to half value in these experiments and in those of Hussey and Thompson, who employed the beta rays from Radium B and C. The close agreement corroborates the idea that the effect is a function of ionization only.
5. The nature of the process of inactivation is discussed; inactivation seems to result from electrical neutralization of the trypsin ion.
STUDIES ON SALT ACTION
Authors: Shaughnessy Howard J. , Criswell Katharine I. 
Published: May 2004

1. The strain of Bacterium coli used in these experiments multiplies in distilled water at pH 6.0 and pH 8.0 and in Ringer-Locke solution at pH 6.0. Under all the other conditions studied the numbers decrease with the passage of time.
2. The electrophoretic charge of the cells is highest in distilled water at pH 6.0 and pH 8.0. Under all other conditions studied the velocity of migration is decreased, but the decrease is immediate and is not affected by more prolonged exposure.
3. A strongly acid solution (pH 2.0) causes a rapid death of the cells and a sharp decrease in electrophoretic charge, sometimes leading to complete reversal.
4. A strongly alkaline solution (pH 11.0) is almost as toxic as a strongly acid one, although in distilled water the organisms survive fairly well at this reaction. Electrophoretic charge, on the other hand, is only slightly reduced in such an alkaline medium.
5. In distilled water, reactions near the neutral point are about equally favorable to both viability and electrophoretic charge, pH 8.0 showing slightly greater multiplication and a slightly higher charge than pH 11.0. In the presence of salts, however, pH 8.0 is much less favorable to viability and somewhat more favorable to electrophoretic charge than is pH 6.0.
6. Sodium chloride solutions, in the concentrations studied, all proved somewhat toxic and all tended to depress electrophoretic charge. Very marked toxicity was, however, exhibited only in a concentration of .725 M strength or over and at pH 8.0, while electrophoretic migration velocity was only slightly decreased at a concentration of .0145 M strength.
7. Calcium chloride was more toxic than NaCl, showing very marked effects in .145 M strength at pH 8.0 and in 1.45 M strength at pH 6.0. It greatly depressed electrophoretic charge even in .0145 M concentration.
8. Ringer-Locke solution proved markedly stimulating to the growth of the bacteria at pH 6.0 while at pH 8.0 it was somewhat toxic, though less so than the solutions of pure salts. It depressed migration velocity at all pH values, being more effective than NaCl in this respect, but less effective than CaCl2.
9. It would appear from these experiments that a balanced salt solution (Ringer-Locke's) may be distinctly favorable to bacterial viability in water at an optimum reaction while distinctly unfavorable in a slightly more alkaline solution.
10. Finally, while there is a certain parallelism between the influence of electrolytes upon viability and upon electrophoretic charge, the parallelism is not a close one and the two effects seem on the whole to follow entirely different laws.
THE ELECTRIC CAPACITY OF SUSPENSIONS WITH SPECIAL REFERENCE TO BLOOD
Authors: Fricke Hugo 
Published: May 2004

1. The specific capacity of a suspension is that capacity which) combined in parallel with a certain resistance, electrically balances 1 cm. cube of the suspension.
2. The following formula holds for the specific capacity of a suspension of spheroids, each of which is composed of a well conducting interior surrounded by a thin membrane of a comparatively high resistance:
See PDF for Equation
C, specific capacity of suspension; Co, static capacity of one sq. cm. of membrane; r, r1 specific resistances respectively of suspension and of suspending liquid; 2 q major axis of spheroid, α constant tabulated in Table I.
3. The following formula holds practically for any suspension whatever the form of the suspended particle.
See PDF for Equation
C = C100 being the specific capacity of a suspension with a concentration of 100 per cent.
Formulæ (1a) and (1b) hold only for the case, when the frequency is so low, that the impedance of the static capacity of the membrane around a single particle is high as compared with the resistance of the interior of the particle. The formulae hold also for a suspension of homogeneous particles, when polarization takes place at the surface of each particle, provided the polarization resistance is low as compared with the impedance of the polarization capacity.
4. A description is given of a method for measuring the capacity of a suspension at frequencies between 800 and 4½ million cycles. By means of a specially designed bridge, a substitution method is employed, by which in the last analysis the suspension is compared with the suspending liquid which is so diluted as to have the same specific resistance as the suspension, consecutive measurements being made in the same electrolytic cell.
5. Formula (1b) is verified by measurements of the capacity of suspensions of varying volume concentrations of the red corpuscles of a dog.
6. By means of the above measurements, the value of Co is calculated by equation (1a).
7. It is found that Co is independent of the frequency up to 4½ million cycles and that it is also independent of the suspending liquid. These results furnish considerable evidence of the validity of the theory, that Co represents the static capacity of a corpuscle membrane.
8. On this assumption and using a probable value for the dielectric constant of the membrane, the thickness of the membrane is calculated to be 3.3·10–7 cm.
THE ELECTRIC RESISTANCE AND CAPACITY OF BLOOD FOR FREQUENCIES BETWEEN 800 AND 4½ MILLION CYCLES
Authors: Fricke Hugo , Morse Sterne 
Published: May 2004

1. The variation of the experimental values (R (ω)), (C (ω)) of the resistance and capacity of blood for increasing frequencies is approximately represented by the equation:
See PDF for Equation
in which Ro and Co are the resistance and capacity of the blood at low frequency and
See PDF for Equation
is the resistance of the blood at infinite frequency. Formulæ (1) and (2) are derived by considering the blood as equivalent to the system shown in the diagram (a) of Fig. 1.
2. By the application of formula (1) to our experimental data the value of R(∞) can be extrapolated with high accuracy. R(∞) represents the resistance) which would have been obtained at low frequency, if the membranes around the corpuscles could have been removed.
3. The specific resistance of the corpuscle interior can be calculated by equation (5), using experimental values for R(∞), for the volume concentration of the blood and for the specific resistance of the serum.
4. The specific resistance of the interior of the red corpuscle of the calf is found to be 3.5 ± 10 per cent times the specific resistance of the serum.