scholarly journals TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT

1939 ◽  
Vol 23 (2) ◽  
pp. 143-163 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Arrhenius Equation ◽  
Temperature Characteristic ◽  
F1 Hybrids ◽  
Intergeneric Cross ◽  
Chemical Mechanisms ◽  
Rods And Cones ◽  
Flicker Response ◽  
Chemical Factors ◽  
Different Shapes ◽  
Critical Intensity

For the teleosts Xiphophorus montezuma, Platypoecilius maculatus, and their F1 hybrids the temperature characteristics (µ in Arrhenius' equation) are the same for the shift of the low intensity and the high intensity segments of the respective and different flicker response contours (critical intensity I as a function of flash frequency F, with light time fraction constant, at 50 per cent). The value of µ is 12,500 calories or a very little less, over the range 12.5 to 36°. This shows that 1/I can be understood as a measure of excitability, with F fixed, and that the excitability is governed by the velocity of a chemical process common to both the classes of elements represented in the duplex performance curve (rods and cones). It is accordingly illegitimate to assume that the different shapes of the rod and cone branches of the curves are determined by differences in the chemical mechanisms of excitability. It is also forbidden to assume that the differing form constants for the homologous segments in the curves for two forms (X. and P.) are the reflections of a difference in the chemical factors of primary excitability. These differences are determined by statistical factors of the distribution of excitabilities among the elements implicated in the sensory effect vs. intensity function, and are independent of temperature and of the temperature characteristic. It must be concluded that the physicochemical nature of the excitatory process cannot be deduced from the shape of the performance contour. The form constants (σ'log I and Fmax.) for F vs. log I are specifically heritable in F1, although µ is here the same as for X. and P. In an intergeneric cross one cannot in general expect Mendelian simplicity of segregation in subsequent generations, and in the present case we find that F2 individuals are indistinguishable from F1, both as regards F vs. log I and as regards the variation of I within a group of 17 individuals. The result in F2 definitely shows, however, that certain specific statistical form constants for the F-log I contour are transmissible in inheritance. It is pointed out that there thus is provided an instance in which statistical (distribution) factors in performance characteristics involving the summating properties of assemblages of cellular units are heritable in a simple manner without the implication of detectable differences in chemical organization of the units involved. This has an important bearing upon the logic of the theory of the gene.

scholarly journals REACTION TO VISUAL FLICKER IN THE NEWT TRITURUS

1940 ◽  
Vol 23 (6) ◽  
pp. 667-676 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Fresh Water ◽  
Response Curve ◽  
Integral Form ◽  
Quantitative Structure ◽  
Rods And Cones ◽  
Flicker Response ◽  
Probability Integral ◽  
Cone Curve ◽  
Critical Intensity

The flicker response curve for the newt Triturus viridescens (water phase) has much the same quantitative structure as that found with various fresh-water teleosts at the same temperature (21.5°). The variability of critical intensity and of critical flash frequency likewise follows the same rules. The cone portion of the F - log I curve is much more widely spread, however. This, and the rather low maximum to which the rod curve rises, produce a considerable overlapping of the two parts additively fused. In addition, and to an extent which differs in various individuals, there is apparent a slight departure from the probability integral form of the cone curve. Reasons are given for considering that this is possibly connected with the role of an additional (small) number of (perhaps temporary, or developmental) retinal elements in addition to the typical rods and cones.

scholarly journals THE FLICKER RESPONSE CONTOURS FOR GENETICALLY RELATED FISHES. II

1939 ◽  
Vol 22 (4) ◽  
pp. 463-485 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
F1 Hybrids ◽  
Genetic Constitution ◽  
Rational Analysis ◽  
Organic System ◽  
Rods And Cones ◽  
Flicker Response ◽  
Physical Organization ◽  
Biological Performance ◽  
Intermediate Value ◽  
Invariant Properties

The flicker response contour has been determined for several species and types of the teleosts Xiphophorus (X.) and Platypoecilius (P.) under the same conditions. The curve (F vs. log Im) is the same for representatives of each generic type, but is different for the two genera. Its duplex nature is analyzable in each instance by application of the probability integral equation to the rod and cone constituent parts. The parameters of this function provide rational measures of invariant properties of the curves, which have specific values according to the genetic constitution of the animal. The F1 hybrids (H'') of X. montezuma x P. variatus show dominance of the X. properties with respect to cone Fmax. and σ' log I, but an intermediate value of the abscissa of inflection (τ'). The rod segment shows dominance of σ' log I from P., but an intermediate value of Fmax. and of τ'. The composite flicker curve involves the operation of two distinct assemblages of excitable elements, differing quantitatively but not qualitatively in physicochemical organization, probably only secondarily related to the histological differentiation of rods and cones because almost certainly of central nervous locus, but following different rules in hereditary determination, and therefore necessarily different in physical organization. The interpretation of the diverse behavior of the three parameters of the probability summation is discussed, particularly in relation to the physical significance of these parameters as revealed by their quantitative relations to temperature, retinal area, and light time fraction in the flash cycle, and to their interrelations in producing the decline of rod effects at higher intensities. It is stressed that in general the properties of the parameters of a chosen interpretive analytical function must be shown experimentally to possess the physical properties implied by the equation selected before the equation can be regarded as describing those invariant properties of the organic system concerned upon which alone can deduction of the nature of the system proceed. The importance of genetic procedures in furthering demonstration that the biological performance considered in any particular case exhibits constitutionally invariant features provides a potentially powerful instrument in such rational analysis.

scholarly journals TEMPERATURE AND CRITICAL ILLUMINATION FOR REACTION TO FLICKERING LIGHT

1939 ◽  
Vol 22 (4) ◽  
pp. 487-499 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Critical Temperature ◽  
Low Temperature ◽  
Arrhenius Equation ◽  
Temperature Characteristic ◽  
Mean Value ◽  
Genetic Evidence ◽  
Flickering Light ◽  
Flicker Response ◽  
Dark Time ◽  
The Mean

For the sunfish Enneacanthus the mean value of the critical illumination for response to visual flicker at constant flash frequency (with light time = dark time) is related to temperature by the Arrhenius equation. The temperature characteristic for 1/Im is different above and below 20°C. In each range (12° to 20°; 20° to 30°) the temperature characteristic is the same for rod and cone segments of the duplex flicker response contour: 8,200 and 14,400. This makes it difficult, if not impossible, to consider that the two groups of elements are organized in a significantly different way chemically. For the presumptively rod-connected elements implicated in response to flicker, the curve is markedly discontinuous, so that the high and low temperature parts are dislocated; whereas for the cones they are not. This is entirely consistent with other (e.g., genetic) evidence pointing to their separate physical substrata. The uncommon exhibition of a higher µ over a higher range of temperature, previously found, however, in a few cases, together with the different relations of rod and cone effects to the critical temperature, explain aspects of these data which in earlier incomplete measurements were found to be puzzling.

scholarly journals ON THE TEMPERATURE CHARACTERISTICS FOR FREQUENCY OF BREATHING MOVEMENTS IN INBRED STRAINS OF MICE AND IN THEIR HYBRID OFFSPRING. I

1931 ◽  
Vol 14 (4) ◽  
pp. 421-443 ◽  
Author(s):  
Gregory Pincus
Keyword(s):  
Critical Temperature ◽  
Inbred Strains ◽  
Temperature Characteristic ◽  
F1 Hybrids ◽  
Temperature Characteristics ◽  
A Value ◽  
Inbred Strains Of Mice ◽  
Biological Reality ◽  
Albino Strain ◽  
Young Mice

Young mice of a selected line of the dilute brown strain of mice exhibit over the range 15–25°C. (body temperature) a relation of frequency of breathing movements to temperature such that when fitted by the Arrhenius equation the data give a value for the constant µ of 24,000± calories or, less frequently, 28,000±. Young mice of an inbred albino strain show over the range 15–20°C. a value of µ = 34,000±, or, less frequently, 14,000±, with a critical temperature at about 20°C. and a value of µ = 14,000± above 20°C. The F1 hybrids of these two strains, and the backcross generations to either parent strain, exhibit only those four values of the temperature characteristic observed in the parent strains and none other. One may therefore speak of the inheritance of the value of the constant µ, but the inheritance shows in this instance no Mendelian behavior. Furthermore there appears to be inherited the occurrence (or absence) of a critical temperature at 20°C. These experiments indicate the "biological reality" of the temperature characteristics.

scholarly journals THE FLICKER RESPONSE FUNCTION FOR THE TURTLE PSEUDEMYS

1939 ◽  
Vol 22 (3) ◽  
pp. 311-340 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf ◽  
Gertrud Zerrahn-Wolf
Keyword(s):  
Flash Intensity ◽  
Rods And Cones ◽  
Sensory Effects ◽  
Retinal Rods ◽  
Fixed Proportion ◽  
Order Of Magnitude ◽  
The Mean ◽  
Probability Integral ◽  
The Individual ◽  
Critical Intensity

1. At constant temperature, with a fixed proportion of light time in a flash cycle (namely, tL/tD = 1), the mean critical intensity for motor response to visual flicker by the turtle Pseudemys scripta follows a probability integral (log I) as a function of flash frequency F. The fit is close and satisfactory; certain quite minor but consistent deviations are adequately explained by features of the experiments. 2. The variation (σI) of critical I is directly proportional to the mean critical intensity (Im), over the entire explorable range. 3. These facts are consistent with the fact that the retina of this turtle is devoid of rods. It contains only cones, histologically, which, with their central representations, provide a single population of sensory effects. The properties of this population are compared with those of homologous populations deduced from corresponding measurements with other forms (various fishes; amphibian; man) which exhibit two such groups of sensory effects associated with the possession of retinal rods and cones. 4. Certain other formulations which have previously been applied to homologous data obtained with other organisms do not properly describe the Pseudemys measurements. 5. The use of a probability integral to describe the data of response to visual flicker for the dissection of the compound curves provided by animals possessing both rods and cones, is accordingly Justified. 6. Persisting differences among individuals of Pseudemys as regards the values of the critical flash intensity under various conditions of experimentation are of the same order of magnitude as are the transitory differences found in lots of other kinds of animals. 7. Determinations of mean critical flash frequency (Fm) at fixed levels of I lie slightly above determinations of Im at fixed values of I, as with other forms. The variation of critical flash frequency goes through a maximum as log I is increased; its height is lower than with certain other forms, in correlation with the low general slope of the F - log I curve (more properly, band). 8. These facts are consistent with the view that the dispersions of the individual critical intensities (and flash frequencies) are determined by organic variation rather than by "experimental error." 9. When the temperature is altered the F - log Im curve is shifted, with no change of Fmax. or of shape; the curve moves to lower intensities as the temperature is raised. 10. The reciprocal of the mean critical intensity, at fixed flash frequency, is a measure of excitability. With increase of temperature (12.5° to 36°) 1/Im for given F follows the Arrhenius equation, exhibiting a "break" at 29.5° (µ = 26,700, 12.5° to 29.5°; 12,400, 29.5° to 36°). This is explained by the necessary theory that, the number of elements of sensory effect required for the index response at fixed F being constant, the ease of their excitation is governed by temperature through its control of the velocity of an interrelated system of catalyzed processes common to all of the sensory elements concerned.

scholarly journals THE FLICKER RESPONSE CONTOUR FOR THE GECKO (ROD RETINA)

1939 ◽  
Vol 22 (5) ◽  
pp. 555-566 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Visual Performance ◽  
Histological Evidence ◽  
Rods And Cones ◽  
Flicker Response ◽  
Intensity Range ◽  
Probability Integral ◽  
Equivalent Conditions

The flicker response contour for the gecko Sphaerodactylus (retina with only rods) agrees in all essential respects (intensity range, shape) with that for the turtle Pseudemys (cone retina), as determined under equivalent conditions with the same apparatus. With experimentally determined correction for the expansion of the iris at the very lowest intensities, the F - log I contour for the gecko is a simple probability integral. Its maximum F is lower than that for other animals; this means simply a smaller number of available sensory elements. The quantitative parallelism in the magnitudes of the intensities at the inflection of F - log I and the shape constants for rod and cone animals show that assumptions from comparative histological evidence concerning the properties of rods and cones in relation to visual performance may be quite misleading.

scholarly journals FLICKER RESPONSE CONTOURS FOR THE SPARROW, AND THE THEORY OF THE AVIAN PECTEN

1944 ◽  
Vol 27 (4) ◽  
pp. 315-324 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Zebra Finch ◽  
House Sparrow ◽  
Passer Domesticus ◽  
Rods And Cones ◽  
Flicker Response ◽  
Analytical Separation

The flicker contour for the house sparrow Passer domesticus is duplex, corresponding to the presence of both rods and cones in the retina. The presence of the pecten brings about changes in the "cone" part of the contour when the light-time in the flash cycle is varied. These changes are of the same sort as those we have already described for the visually simplex zebra finch, and for man provided with an artificial "pecten shadow." The changes are such as to greatly enhance flicker acuity for small dark-times (moving stripe technique). The form of the scotopic part of the duplex contour (also as in the case with man) gives no evidence that rod excitation is specifically influenced by the presence of the pecten. The changing integration of "rod" and "cone" effects as the light-time fraction is altered provides another means of testing the theory used for the analytical separation of the two components of the duplex flicker contour.

scholarly journals THE SIMPLEX FLICKER THRESHOLD CONTOUR FOR THE ZEBRA FINCH

1941 ◽  
Vol 24 (5) ◽  
pp. 625-633 ◽  
Author(s):  
W. J. Crozier ◽  
Ernst Wolf
Keyword(s):  
Zebra Finch ◽  
Visual Theory ◽  
Time Ratio ◽  
Flicker Response ◽  
Dark Time ◽  
Normal Probability ◽  
Probability Integral ◽  
Critical Intensity

The flicker response contour has been determined, with equality of light-dark time ratio, for the diurnal bird the Australian zebra finch. This bird has only cones in the retina. The curve of log critical intensity as a function of flash frequency is simplex, a normal probability integral. In this respect it is like that for other vertebrates not exhibiting visual duplexity. The parameters of the curve most closely approach those for the turtle Pseudemys (extrapolated to about the same temperature); it is not improbable that the approximation of these two curves would be less close for other values of the light-time fraction. Some points of interpretive visual theory are discussed in relation to the present measurements.

scholarly journals The role of hazardous factors of chemical and physical nature in welders’ occupational risks management

2021 ◽  
Vol 273 ◽  
pp. 12028
Author(s):  
Yuriy Bulygin ◽  
Elena Andreeva ◽  
David Shoniya
Keyword(s):  
Chemical Nature ◽  
Arrhenius Equation ◽  
Physical Nature ◽  
Physical Factor ◽  
Dust Particles ◽  
Occupational Risks ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Near Future

The article is devoted to a review of the available scientific approaches to assess the role of hazardous factors of physical and chemical nature, which are very important for the management of occupational risks of workers in dust-hazardous industries using the example of welders. General approaches and models for assessing the risk to public health in general are presented quite fully, the mechanisms of the effect of dust particles on the development of occupational pathologies in welders, including toxic and carcinogenic ones, have been studied in depth, a number of articles are devoted to the study of the effect of a thermal (physical) factor of a chronic nature. The above studies are of a scattered nature, the combined effect of physical and chemical factors are not taken into account, based on the S. Arrhenius equation, which is especially important in the closed spaces of the working area. There is no comprehensive methodology for assessing health risks for workers in dust-hazardous industries and welders. The development of the above-mentioned comprehensive methodology for assessing health risk of workers in dust-hazardous industries based on taking into account hazardous factors of physical and chemical nature is very promising in the near future.

scholarly journals CRITICAL THERMAL INCREMENT FOR THE MOVEMENT OF OSCILLATORIA

1924 ◽  
Vol 7 (1) ◽  
pp. 137-150 ◽  
Author(s):  
W. J. Crozier ◽  
H. Federighi
Keyword(s):  
Chemical Process ◽  
Arrhenius Equation ◽  
Temperature Characteristic ◽  
Translatory Motion ◽  
Exact Measurement ◽  
Different Temperatures ◽  
In Series

In a species of Oscillatoria exhibiting movement of type suitable for exact measurement the velocity of linear translatory motion is found to be controlled by the temperature (6 – 36°C.) in accordance with Arrhenius' equation for irreversible reactions. The value of the critical increment (µ) is 9,240. The extreme variates in series of measurements at different temperatures yield the same value of µ. The velocity of movement is therefore regarded as determined by the velocity of an underlying chemical process, controlled by the temperature and by the amount of a substance (? catalyst) whose effective quantity at any moment varies within definite limits in different filaments of the alga. On the basis of its temperature characteristic the locomotion of Oscillatoria is compared with certain other processes for which this constant is calculated.

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