bluuebunny/crossref_metadata_2025_split huggingface dataset:
ON GUAIACOL SOLUTIONS
Authors: Shedlovsky Theodore , Uhlig Herbert H. 
Published: May 2004

1. Measurements on the densities, viscosities, dielectric constants, and specific conductances of pure anhydrous and water-saturated guaiacol at 25°C. are reported.
2. The solubility of water in guaiacol at 25°C., and its effect on the electrical conductivity of a sodium guaiacolate solution is given.
3. Electrical conductivity measurements are reported on solutions of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C.
4. The decrease of electrical conductivity with increasing concentration for these salts is explained on the basis of an ionic equilibrium combined with the interionic attraction theory of Debye and Hückel.
5. The limiting equivalent conductances of sodium and potassium guaiacolates in water-saturated guaiacol at 25°C., the corresponding limiting ionic mobilities, and the dissociation constants are computed from the conductivity measurements. The salts are found to be weak electrolytes with dissociation constants of the order of 5 x 10–6.
INFLUENCE OF DEATH CRITERIA ON THE X-RAY SURVIVAL CURVES OF THE FUNGUS, NEUROSPORA
Authors: Uber Fred M. , Goddard David R. 
Published: May 2004

1. When ascospores of Neurospora tetrasperma were irradiated with 11 kv. X-rays, the single spore cultures obtained displayed a wide variety of mutated forms.
2. Control germinations of ascospores showed uniform behavior, ranging from 92–95 per cent germination.
3. The shape of the survival curves was found to be a function of the criterion of death. The following criteria were used: germination, growth, production of mature ascospores, and the production of normal perithecia.
4. The germination survival curve exhibited a rhythmic variation with dosage. Germination is not a significant criterion of death.
5. Half-survival dosages for growth and ascospore production were approximately 30,000 and 20,000 roentgens, respectively.
6. Multiple hit-to-kill relations were found on the basis of the quantum hit theory; no accurate analysis was possible.
7. The studies indicate that ascospore death does not result from a single well defined reaction, but rather from the integrated effects of several deleterious processes initiated by the radiation.
BOUND WATER IN MUSCLE
Authors: Brooks J. 
Published: May 2004

1. The amount of free unfrozen water, i.e. water acting as normal solvent, in frog's muscle at temperatures below the initial freezing-point has been calculated from the vapour pressure isotherm of the muscle.
2. Significant amounts of free water are present at –20°C. The total amount of unfrozen water at –20°C. cannot, therefore, be taken as a measure of the bound water in muscle.
3. The calculated values of free water, when compared with experimentally determined values of total unfrozen water, indicate that the amount of bound water in muscle at various temperatures is small.
4. A temperature considerably below –20°C., roughly between –40° and –60°C., is required to freeze completely the free water in muscle.
THE INFLUENCE OF MINIMAL NARCOTIC DOSES ON THE RESPIRATION OF ERYTHROCYTES
Authors: Fleischmann Walter , Rand Charles S. 
Published: May 2004

Low concentrations of ethyl alcohol stimulate the respiration of mammalian erythrocytes in vitro.
Low concentrations of ethyl urethan remain without effect on, or tend slightly towards depressing the respiration of mammalian erythrocytes in vitro.
It is suggested that this may be due to the oxidizable nature of alcohol, and the non-oxidizable nature of urethan, properties which come into evidence only when these narcotics are present in such low concentrations that the threshold of inhibition (narcosis) has not been reached.
SEARCH FOR MITOGENETIC RADIATION BY MEANS OF THE PHOTOELECTRIC METHOD
Authors: Lorenz Egon 
Published: May 2004

The intensity of mitogenetic radiation was estimated from data given by Gurwitsch.
The sensitivity of the biological method and of the physical methods were compared.
With onion-base pulp and onion roots as mitogenetic inductors, the photographic method gave no perceptible blackening for exposures up to 184 hours.
A photoelectric counter tube was described with cadmium as photoelectric metal. Its sensitivity was such that a radiation intensity of 10 to 15 quanta per cm.2 per second of the Hg line 2536 A was detectable.
Spurious effects produced by the counter tube were described and means for their avoidance given.
A number of different biological materials, all supposed to be excellent mitogenetic radiators, were investigated by means of the counter tube. No mitogenetic radiation could be detected.
THE PREPARATION OF THE GRADED COLLODION MEMBRANES OF ELFORD AND THEIR USE IN THE STUDY OF FILTERABLE VIRUSES
Authors: Bauer Johannes H. , Hughes Thomas P. 
Published: May 2004

1. The method described by Elford for the preparation of graded collodion membranes suitable for ultrafiltration was found to give excellent results, and his findings are fully confirmed.
2. A formula is given for the preparation of collodion from which satisfactory membranes of graded porosity can be prepared.
3. The technique and apparatus used in the preparation, and standardization of membranes are described in detail.
4. The technique and apparatus required for ultrafiltration experiments are described, and some drawbacks encountered in the experiments are discussed.
5. The results of ultrafiltration experiments show that the pores of the membranes are remarkably uniform in size.
NATURE OF THE ACTION CURRENT IN NITELLA
Authors: Osterhout W. J. V. 
Published: May 2004

The outstanding features of the action curve in Nitella are explained as due to the movement of potassium ions accompanied by increase of permeability. This may be useful as a working hypothesis since it accounts not only for the normal behavior but also for many striking deviations which will be treated in subsequent papers.
The views here set forth are in harmony with the local circuit theory of stimulation.
THE KINETICS OF PENETRATION
Authors: Kamerling S. E. , Osterhout W. J. V. 
Published: May 2004

To imitate cells which have ceased to grow we have made models in which artificial sap is separated from the external solution by a non-aqueous layer (representing the protoplasm). A stream of CO2 is bubbled through the artificial sap to imitate its production by the living cell.
Potassium passes from the external solution through the non-aqueous layer into the artificial sap and there reacts with CO2 to form KHCO3: its rate of entrance depends on the supply of CO2. Hence the increase of volume depends on the supply of CO2 (as is probably true of the living cell).
By regulating the supply of CO2 and the osmotic pressure we are able to keep the volume and composition of the artificial sap approximately constant while maintaining a higher concentration of potassium than in the external solution. In these respects the model resembles certain mature cells which have ceased to grow.
SOME TEMPERATURE CHARACTERISTICS IN MAN
Authors: Hoagland Hudson , Perkins Clifton T. 
Published: May 2004

The value of µ = 29,400 has been found for the human heart beat over the temperature range of approximately 4.7°C. This value is different from that of 24,000 calories which has been obtained for the effect of temperature on judgments of short durations.
The evidence indicates that the estimation of short time intervals is controlled by a chemical master reaction which is independent of the pulse rhythm.
STUDIES ON BLOOD COAGULATION
Authors: Eagle Harry 
Published: May 2004

1. A method is described for the preparation and titration of prothrombin and thrombin.
2. Confirming the views of Morawitz, Howell (1916–17, 1925), and Bordet, thrombin cannot be regarded as an artificial by-product of coagulation (Wooldridge, Nolf (both quoted from Morawitz)). Calcium, a platelet factor, and a plasma factor (prothrombin) interact to form thrombin, and this then acts upon fibrinogen to form fibrin. The amount and rate of thrombin formation in the first reaction are independent of the presence or absence of fibrinogen. After a variable latent period, thrombin suddenly appears in large quantities, coincident with or immediately preceding the deposition of fibrin if fibrinogen is present.
3. The amount of thrombin formed in a mixture of prothrombin, Ca and platelets is independent of the platelet or Ca concentration, and depends primarily upon the amount of prothrombin used. The platelets (or cephalin) enormously accelerate the transformation of prothrombin to thrombin, and this acceleration seems to be their physiological rôle in the coagulation process.
4. Contrary to previous reports, platelets have not been demonstrated to contain significant quantities of prothrombin.
5. The available data do not allow any definite decision as to whether the platelet factor actually combines with prothrombin to form thrombin, or merely catalyzes the transformation. The very slow formation of thrombin in the complete absence of platelets may be due to dissolved traces of platelet material released during the physical manipulation of the plasma (centrifuging, Berkefeld filtration).
6. There was no evidence for a species-specific activity of platelets in the transformation of prothrombin to thrombin.
QUANTITATIVE STUDIES ON THE PHOTOLETHAL EFFECTS OF QUARTZ ULTRA-VIOLET RADIATION UPON PARAMECIUM
Authors: Giese A. C. , Leighton P. A. 
Published: May 2004

Paramecia grown under controlled conditions were irradiated at known intensities of light of wave-lengths 2537, 2654, 2804, 3025, and 3130 A. The approximate absorption of the light by the Parmecia was found to be greatest and of the same order of magnitude at the three shortest wave-lengths, considerably less at 3025, and least at 3130 A.
Paramecia did not die when irradiated with high dosages of intense light of wave-length 3130 A. At the other wave-lengths 50 per cent vesiculation occurred when between 1012 and 1013 quanta had been absorbed by a Paramecium. This would indicate that a very large number of molecules in a Paramecium are affected before vesiculation occurs.
THE RELATION BETWEEN CHLOROPHYLL CONTENT AND RATE OF PHOTOSYNTHESIS
Authors: Fleischer Walter E. 
Published: May 2004

1. Data are presented which support the conclusion of Emerson (1929) that the rate of photosynthesis is proportional to the chlorophyll content when the latter is varied by varying the iron supply. These data give a straight line passing through the origin, which is not true of Emerson's results.
2. Similar data are presented which show that a similar relation exists when nitrogen controls the chlorophyll content.
3. Evidence is given which indicates that magnesium plays a part in the process of photosynthesis in addition to its effect upon the chlorophyll content.
MECHANICAL RESTORATION OF IRRITABILITY AND OF THE POTASSIUM EFFECT
Authors: Hill S. E. , Osterhout W. J. V. 
Published: May 2004

Treatment of Nitella with distilled water apparently removes from the cell something which is responsible for the normal irritability and the potassium effect, (i.e. the large P.D. between a spot in contact with 0.01 M KCl and one in contact with 0.01 M NaCl). Presumably this substance (called R) is partially removed from the protoplasm by the distilled water. When this has happened a pinch which forces sap out into the protoplasm can restore its normal behavior.
The treatment with distilled water which removes the potassium effect from the outer protoplasmic surface does not seem to affect the inner protoplasmic surface in the same way since the latter retains the outwardly directed potential which is apparently due to the potassium in the sap. But the inner surface appears to be affected in such fashion as to prevent the increase in its permeability which is necessary for the production of an action current. The pinch restores its normal behavior, presumably by forcing R from the sap into the protoplasm.
ON THE RELATION OF DIRECT CURRENTS TO CONDENSER DISCHARGES AS STIMULI
Authors: Blair H. A. 
Published: May 2004

Data on the electrical stimulation of sciatic-gastrocnemius preparations of the frog by both direct currents and condenser discharges at the same time are discussed in relation to the validity of the differential equation
See PDF for Equation
where p is the local excitatory process, V the stimulating current or voltage, and K and k are constants. It is concluded that the constant k is the same whether it is derived from the data of the one stimulus or the other when the same fibres are being stimulated.
THE ELECTRIC IMPEDANCE OF HEMOLYZED SUSPENSIONS OF MAMMALIAN ERYTHROCYTES
Authors: Fricke Hugo , Curtis Howard J. 
Published: May 2004

This paper is concerned with the changes in the electric surface capacity and surface resistivity of the membrane surrounding the mammalian red corpuscle, as a result of various types of hemolysis. In the case of hemolysis with water, the cells swell with no apparent change in the electric properties of the membrane. They then hemolyze, but the membrane persists, although showing evidence of injury, as indicated by a change in the frequency dependence of its capacity and resistivity at low frequencies. The fact that a change of the frequency dependence takes place shows that the injury cannot be due merely to a rupture in the membrane, but must be due to changes in the properties (increased permeability) of the membrane as a whole.
With chemical lysins (saponin, complement and amboceptor, digitonin, sodium taurocholate) a similar type of injury to the membranes of a certain number of the corpuscles takes place, to an increasing extent as the concentration of lysin is increased. The rest of the corpuscles become completely permeable to the electric current, and as the amount of lysin is increased, this number of completely permeable corpuscles increases until all are affected. This change, presumably associated with a disintegration of the corpuscle membrane, is referred to as stromatolysis, and the method gives a quantitative means of determining percentage stromatolysis.
For lysis by freezing and thawing, the results obtained indicate this type of lysis to be different from that of the others studied.
THE EFFECT OF LIGHT INTENSITY, AREA, AND FLICKER FREQUENCY ON THE VISUAL REACTIONS OF THE HONEY BEE
Authors: Wolf Ernst , Zerrahn-Wolf Gertrud 
Published: May 2004

1. For the phototropic reaction of bees, the stimulating effects of two illuminated fields differing in intensity and area become equal when the product of area and intensity is the same for both fields.
2. The effect of two areas differing in size and flicker frequency is the same for the bee, when the product of area and flicker frequency is equal for both fields.
3. If two patterns of the same character but varying in size and coarseness are presented to bees for free choice, a 1:1 ratio of choices is obtained when both patterns stimulate equal numbers of retinal elements alternately by transition from one state of excitation to another.
VITAMIN A IN EYE TISSUES
Authors: Wald George 
Published: May 2004

1. Vitamin A has been found in the retinas and the combined pigment epithelia and choroid layers of frogs, pigs, sheep, and cattle. The vitamin was identified by (a) its specific absorption at 328 mµ; (b) the blue color yielded with antimony trichloride, associated with an absorption band at about 620 mµ; (c) anti-xerophthalmic and growth-promoting activity; and (d) quantitative relationships among the results of these three types of observation.
2. The mammalian retinas contain about 22γ, the frog retinas about 400γ, and the frog pigmented layers almost 2 mg. of vitamin A per gram of dry tissue.
3. With the possible exception of hepaxanthin, no other carotenoids were found in the mammalian tissues.
THE RESPONSE OF SINGLE VISUAL SENSE CELLS TO LIGHTS OF DIFFERENT WAVE LENGTHS
Authors: Graham C. H. , Hartline H. K. 
Published: May 2004

The effect of various wave lengths of visible light in the stimulation of single visual sense cells has been studied by means of the single fiber preparation from the eye of Limulus. Oscillographic records were made of the impulse discharge in a single optic nerve fiber in response to stimulation of the attached sense cell by lights of different wave lengths. Wratten monochromatic filters supplied the means for obtaining the different spectral lights; the total intensity supplied to the eye being determined by a thermopile and galvanometer.
With lights of approximately equal energy content the strongest response occurs to the green region of the spectrum. The response, however, does not vary qualitatively with wave length. By the proper adjustment of intensity, responses can be obtained which are identical, impulse for impulse, for all the spectral lights used. Moreover the ratios of the intensities for the various wave lengths necessary to produce a constant response do not vary with the intensity level of the stimulating lights; there is no Purkinje effect. The single visual sense cell can gauge brightness but cannot distinguish wave length.
The reciprocals of the intensities necessary to produce a constant response when plotted against wave length give the visibility curve for the single sense cell. This curve is symmetrical about a maximum at λ520mµ, falling off to low values in the red and violet. It closely resembles the visibility curve for human rod vision.
Bundles from the optic nerve containing several active fibers whose impulses can be distinguished by differences in form and magnitude or whose attached sense cells can be located and illuminated independently were used to determine whether there is any differential sensitivity among sense cells in the same eye for different regions of the spectrum. Such a differential sensitivity has been found to exist in the eye of Limulus and may be considered a peripheral mechanism of color vision.
THE COMBINATION OF DIVALENT MANGANESE WITH CERTAIN PROTEINS, AMINO ACIDS, AND RELATED COMPOUNDS
Authors: Main Raymond K. , Schmidt Carl L. A. 
Published: May 2004

1. A study of the mode of combination which takes place between certain amino acids, proteins, various carboxylic acids, and certain sulfonic acids and manganous ions to form complexes is reported.
2. Three criteria for complex formation were used: (a) the equilibrium between the substance under test and manganous ions dissolved in aqueous buffered solution and isonitrosoacetophenone dissolved in chloroform; (b) the electrophoretic migration of manganese in the presence of the test substance with varying pH; and (c) anomalous titration.
3. The following classes of substances were found to possess the necessary groupings to form manganese complexes: hydroxy-monocarboxylic acids (lactic, gluconic), dicarboxylic acids (oxalic, malonic), hydroxy-, di- and tricarboxylic acids (citric, tartaric), dicarboxylic amino acids (aspartic, glutamic), certain inorganic acids (phosphoric, sulfuric), certain phosphoric acid-containing compounds (nucleic, glycerophosphoric), certain aromatic enol sulfonic acids (phenolsulfonic, catecholsulfonic), and certain proteins (casein, edestin, gelatin).
4. A correlation between the amount of manganese bound by the several proteins and the free carboxyl and phosphoric acid groups has been made.
5. An explanation based on the residual charge of certain atoms is advanced for the manner in which divalent manganese may be united by the compounds studied.
INCREASED PERMEABILITY TO WATER OF AGING UNFERTILIZED EGGS (ARBACIA PUNCTULATA)
Authors: Goldforb A. J. 
Published: May 2004

1. Unfertilized Arbacia eggs, subjected to 50, 60, or 80 per cent sea water, at the same temperature, pH, and duration, swelled progressively faster with age. Swelling increased 12.2 to 39.6 per cent.
2. Permeability to water was calculated by the method of Lucké and McCutcheon. For freshly shed eggs from nine different females, permeability varied from 0.078 to 0.124, or 59 per cent. This variation was not due to differences in age nor to physiologic condition but was correlated with size of eggs.
3. About twenty eggs were tested each age to 60 hours after shedding. The permeability rate increased with age in all nine experiments.
4. The total increase ranged from 30 to 69 per cent.
5. The increase was slow but constant or almost constant during early and intermediate ages.
6. The increase began at earliest ages.
7. An increase may not be demonstrable for any short interval but is readily demonstrable for longer intervals (6 or more hours), or, from the entire curve.
8. Permeability increased faster at late ages. For special factors during late ages see text.
9. Injury by experimental procedure was not induced until ca. the 24th hour. Injury by aging was not detectable during the first 6 to 9 hours. It increased progressively between 10 and 24 hours, and very rapidly thereafter. Permeability increased at approximately the same rate during early and intermediate ages. Permeability therefore was not correlated with degree of injury.
10. The troublesome factor in the permeability equation was initial size, or Vo. Several methods were used to obtain this Vo, viz. (a) extrapolations approximating known cyclical change in size, (b) extrapolations approximating control sizes, (c) constant or average of all Vo's, (d) maximum Vo approximating control Vo's. Recalculation with these different Vo's gave approximately the same permeabilities.
11. The increase in permeability with age was substantially the same whether "approved," or other possible rates or average rates or range of rates be used as criteria of change.
12. When the data were recalculated by integrating the equation of Northrop, the increases in permeability with age were essentially the same as the increases calculated by the graphic method of Lucké.
THE ACCUMULATION OF ELECTROLYTES
Authors: Osterhout W. J. V. , Kamerling S. E. 
Published: May 2004

Models are described in which KCl enters until its chemical potential becomes much greater inside than outside. The energy needed to accomplish this comes from the chemical reactions occurring in the system and the continual supply of certain materials. An important factor is the maintenance of a lower pH value inside by means of CO2. This may be analogous to what happens in some living cells.
The concentration of K+ becomes higher inside, as happens in many living cells, but the concentration of Cl- does not and in this respect the model differs from many living cells. As in Valonia, potassium tends to go out as KCl when the ionic activity product (K)(Cl) is greater inside but at the same time it tends to enter as KOH since the activity product (K)(OH) is greater outside. The net result is entrance of potassium presumably because the latter process is the more rapid.
ELECTROPHORESIS OF STEROLS
Authors: Moyer Laurence S. 
Published: May 2004

1. No significant differences were noted between the electrophoretic mobilities of unground cholesterol crystallized from alcohol, acetone, or the melted state.
2. On grinding with ice at –10°C. the mobility drops to less than half (at pH 5.8) that observed in the unground state. This equilibrium condition is reached after 50 minutes grinding. Cholesterol crystals from alcohol or acetone behave identically throughout the course of this change.
3. When cholesterol crystals which have been ground with ice are dried in vacuo at room temperature they revert to the mobility of unground cholesterol. The cause of this phenomenon is discussed.
4. Both ground and unground cholesterol have an isoelectric point near pH 3.0, even after crystallization from the melted state.