The Colour Change of the Minnow (PHOXINUS LAEVIS AG.)

1954 ◽  
Vol 31 (4) ◽  
pp. 473-490
Author(s):  
E. G. HEALEY
Keyword(s):  
Statistical Treatment ◽  
Colour Change ◽  
Spinal Nerve ◽  
White Background ◽  
Nerve Fibres ◽  
Degree Of Dispersion ◽  
Colour Changes ◽  
Spinal Section ◽  
The Times ◽  
Different Levels

1. Minnows were subjected to spinal section at different levels between vertebrae 4 and 15, and the degree of dispersion of all the main melanophore regions was recorded in terms of the melanophore index. 2. Records were made of the times required to reach equilibrium (a) when the fish were placed after the operation on a black or white illuminated background, and (b) when the fish at equilibrium on a black or white background were subjected to background reversal. 3. These records show that the times necessary for the melanophores to reach equilibrium on a given background are of the same order at all the vertebral levels investigated. 4. There is considerable variation in the degree of dispersion of similar melanophore regions of different individuals under the same conditions of operation and background. The nature of these individual differences is not known. 5. Apart from the possibility of incomplete section of chromatic nerve fibres near the 15th vertebra, there appears to be no correlation between the chromatic behaviour and the level of the operation; i.e. there is no indication that any activity of the spinal paling centre is being affected by spinal section at the different levels. 6. The results of experiments involving the elimination of the spinal paling centre were tested statistically. Within the limits of this treatment, based upon the melanophore index, it was concluded that the spinal paling centre plays no part in these colour changes. 7. Spinal section was carried out anterior to the 1st spinal nerve in order to interrupt the path of von Gelei's dispersing fibres. Statistical treatment of the results indicates that these fibres are playing no part in these colour changes. 8. Experiments involving combined spinal and autonomic section confirm the conclusions given in paragraphs 6 and 7. 9. Since no activity of the nervous system arising from the spinal paling centre or resulting from the background through von Gelei's dispersing fibres appears to be involved, the colour changes of these spinal minnows in response to illuminated backgrounds must be controlled by hormones alone. 10. In these spinal fish the various melanophore regions do not all react equally in terms of the melanophore index. Thus, those of the lateral stripe and associated dark pattern tend to have relatively higher M.I. values under all conditions.

Experimental evidence for the regeneration of nerve fibres controlling colour changes after anterior spinal section in the minnow ( Phoxinux Phoxinus L)

1967 ◽  
Vol 168 (1010) ◽  
pp. 57-81 ◽  
Keyword(s):  
Colour Change ◽  
Hormonal Control ◽  
Whole Body ◽  
White Background ◽  
Nerve Fibres ◽  
Nervous Control ◽  
Colour Changes ◽  
Spinal Section ◽  
Final Degree ◽  
Degree Of Recovery

A method for quantitative recording of the general tint of the skin of the minnow is described. Using this method, the colour changes in response to black/white background reversal of normal and of equilibrated chromatically spinally operated minnows, previously black- or white-adapted for more than 9 months, were plotted to give standard curves. These enabled a clear distinction to be made between the rapid colour changes of the normal minnow with intact chromatic nervous system and the relatively very slow changes, only under hormonal control, of the chromatically spinally operated fish. Twenty minnows that had been white-adapted for more than 9 months and 19 that had been black-adapted for the same time were subjected to chromatic spinal section and replaced on the same backgrounds. At intervals their colour changes were recorded and plots of these records were compared with the standard curves. In the course of about 10 months 11 of these minnows showed a good recovery of rapid colour change, 9 showed medium recovery, 8 showed poor recovery and 11 continued to change colour at a rate typical of hormonal control. After another 9 months there was generally no further improvement. This varying degree of recovery of rapid colour change appears to have been the result of regeneration of chromatic fibres in the spinal cord, since a second section anterior to the level of the first and made 19 months after it was followed by darkening of the whole animal. Later it was able to change colour again in response to background reversal but these colour changes were of the slow hormonal type. Observations that recovery of nervously controlled colour change improved with time until some steady condition was reached and that there was great variation in this final degree of nervous control suggest that a number of chromatic fibres may run in the cord. Further,since the colour and pattern produced by the melanophores were affected equally over the whole body as the recovery of rapid colour change proceeded, it appears possible that each chromatic nerve fibre in the cord contributes to the state of excitation of a postganglionic system which is common to all the melanophores in the skin. Records of colour changes at certain stages during regeneration in the cord indicate that there was recovery of nervous control in one direction, i.e. for paling or darkening, while the change in the other direction was still only hormonal. Such observations suggest, in addition to the familiar concept of a nervous aggregating system, the existence of an active pigment-dispersing nervous mechanism.

The Colour Change of the Minnow (Phoxinus Laevis AG.)

1951 ◽  
Vol 28 (3) ◽  
pp. 298-319
Author(s):  
E. G. HEALEY
Keyword(s):  
Spinal Cord ◽  
Colour Change ◽  
White Background ◽  
Time Intervals ◽  
Black Background ◽  
Colour Changes ◽  
The Times

1. Records were made of the times required for the melanophores of the normal minnow to reach equilibrium when the fish is transferred from one to another of the following conditions: on an illuminated white background; on an illuminated black background; in darkness. 2. These times give further evidence of the parts played by nervous and hormonal mechanisms in the colour change of the minnow. 3. After section of the spinal cord between the 5th and the 12th vertebrae the fish darkens but gradually becomes pale again if kept on an illuminated white background. 4. Such fish can still show a slow colour change: dark on a black background, pale on a white background and intermediate in darkness. 5. Observations of the times required for these colour changes in the spinal minnow show that these no longer resemble those associated with the unoperated fish; rather, they resemble the time intervals associated with amphibian colour change. 6. Further consideration of the times required for colour change in the spinal minnow indicate that there is not only a hormone causing aggregation of the melanophores but also a hormone causing melanophore dispersion. 7. The part played by double innervation of the melanophores is considered.

scholarly journals Alteration of Tissue Marking Dyes Depends on Used Chromogen during Immunohistochemistry

Cells ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 835
Author(s):  
Selina Kiefer ◽  
Julia Huber ◽  
Hannah Füllgraf ◽  
Kristin Sörensen ◽  
Agnes Csanadi ◽  
...  
Keyword(s):  
Colour Change ◽  
Residual Tumour ◽  
Blue Colour ◽  
Close Margin ◽  
Correct Orientation ◽  
Therapeutic Regime ◽  
Colour Changes ◽  
Tissue Specimens ◽  
Immunohistochemical Analyses ◽  
Colour Signal

Pathological biopsy protocols require tissue marking dye (TMD) for orientation. In some cases (e.g., close margin), additional immunohistochemical analyses can be necessary. Therefore, the correlation between the applied TMD during macroscopy and the examined TMD during microscopy is crucial for the correct orientation, the residual tumour status and the subsequent therapeutic regime. In this context, our group observed colour changes during routine immunohistochemistry. Tissue specimens were marked with various TMD and processed by two different methods. TMD (blue, red, black, yellow and green) obtained from three different providers (A, B and C, and Whiteout/Tipp-Ex®) were used. Immunohistochemistry was performed manually via stepwise omission of reagents to identify the colour changing mechanism. Blue colour from provider A changed during immunohistochemistry into black, when 3,3′-Diaminobenzidine-tetrahydrochloride-dihydrate (DAB) and H2O2 was applied as an immunoperoxidase-based terminal colour signal. No other applied reagents, nor tissue texture or processing showed any influence on the colour. The remaining colours from provider A and the other colours did not show any changes during immunohistochemistry. Our results demonstrate an interesting and important pitfall in routine immunohistochemistry-based diagnostics that pathologists should be aware of. Furthermore, the chemical rationale behind the observed misleading colour change is discussed.

scholarly journals Indicator Layers Based on Ethylene-Vinyl Acetate Copolymer (EVA) and Dicyanovinyl Azobenzene Dyes for Fast and Selective Evaluation of Vaporous Biogenic Amines

Sensors ◽  
2018 ◽  
Vol 18 (12) ◽  
pp. 4361
Author(s):  
Tinkara Mastnak ◽  
Aleksandra Lobnik ◽  
Gerhard Mohr ◽  
Matjaž Finšgar
Keyword(s):  
Biogenic Amines ◽  
Vinyl Acetate ◽  
Colour Change ◽  
Ethylene Vinyl Acetate ◽  
Yellow Orange ◽  
Colour Changes ◽  
Limit Sensitivity ◽  
Linear Concentration Range ◽  
Acetate Copolymer ◽  
Ethylene Vinyl Acetate Copolymer

The article presents naked-eye methods for fast, sensitive, and selective detection of isopentylamine and cadaverine vapours based on 4-N,N-dioctylamino-4′-dicyanovinylazobenzene (CR-528) and 4-N,N-dioctylamino-2′-nitro-4′-dicyanovinylazobenzene (CR-555) dyes immobilized in ethylene-vinyl acetate copolymer (EVA). The reaction of CR-528/EVA and CR-555/EVA indicator layers with isopentylamine vapours caused a vivid colour change from pink/purple to yellow/orange-yellow. Additionally, CR-555/EVA showed colour changes upon exposure to cadaverine. The colour changes were analysed by ultraviolet–visible (UV/VIS) molecular absorption spectroscopy for amine quantification, and the method was partially validated for the detection limit, sensitivity, and linear concentration range. The lowest detection limits were reached with CR-555/EVA indicator layers (0.41 ppm for isopentylamine and 1.80 ppm for cadaverine). The indicator layers based on EVA and dicyanovinyl azobenzene dyes complement the existing library of colorimetric probes for the detection of biogenic amines and show great potential for food quality control.

The Artisential® Articulated Laparoscopic Forceps: A Dry Lab Study to Examine Dexterity and Learning Effects in Operators with Different Levels of Laparoscopic Experience

2021 ◽  
Author(s):  
Ibrahim Darwich ◽  
Mohammad Abuassi ◽  
Christel Weiss ◽  
Dietmar Stephan ◽  
Frank Willeke
Keyword(s):  
Learning Effect ◽  
Training Session ◽  
Transfer Task ◽  
Learning Effects ◽  
Laparoscopic Instrument ◽  
Significant Difference ◽  
The Times ◽  
Time Required ◽  
Laparoscopic Experience ◽  
Different Levels

Purpose: The advent of robotic surgery has highlighted the advantages of articulation. This dry-lab study examined the dexterity and learning effect of a new articulated laparoscopic instrument: the ArtiSential® forceps (LIVSMED, Seongnam, Republic of Korea). Methods: A peg board task was designed. Three groups of volunteers with varying levels of laparoscopic expertise were organized to perform the task: expert, intermediate and novice. The participants performed the task using articulated and straight instruments, once before a 30-min training session and once afterwards. The times required to perform the task were recorded. The performances were analyzed and compared between the groups as well as between the straight and articulated instruments. Results: The experts were significantly faster than the novices with both instruments before the 30-min training session (p = 0.0317 for each instrument). No significant time difference was found among the three groups after the 30-min training session. The decrease in the time required to perform the peg-transfer task with the articulated instrument was significantly greater in the novice and intermediate groups (p = 0.0159 for each group). No significant difference in time reduction was observed between the groups with the straight instrument. Regardless of the user, the articulated device was associated with faster task performance than the straight device after 8 hours of training (p = 0.0039). Conclusion: The ArtiSential® articulated device can improve dexterity. A significantly greater learning effect was observed in the novice and intermediate groups in comparison with experts. A plateau in the learning curve was observed after a few hours of training.

scholarly journals Influence of Natural and Artificial Weathering on the Colour Change of Different Wood and Wood-Based Materials

Forests ◽  
2018 ◽  
Vol 9 (8) ◽  
pp. 488 ◽  
Author(s):  
Davor Kržišnik ◽  
Boštjan Lesar ◽  
Nejc Thaler ◽  
Miha Humar
Keyword(s):  
Laboratory Test ◽  
Colour Change ◽  
Natural Weathering ◽  
Blue Staining ◽  
Artificial Weathering ◽  
Blue Stain Fungi ◽  
Colour Changes ◽  
Blue Stain ◽  
Positive Correlations ◽  
The Aesthetic

The importance of the aesthetic performance of wood is increasing and the colour is one of the most important parameters of aesthetics, hence the colour stability of twelve different wood-based materials was evaluated by several in-service and laboratory tests. The wood used for wooden façades and decking belongs to a group of severely exposed surfaces. Discolouration of wood in such applications is a long-known phenomenon, which is a result of different biotic and abiotic causes. The ongoing in-service trial started in October 2013, whilst a laboratory test mimicking seasonal exposure was performed in parallel. Samples were exposed to blue stain fungi (Aureobasidium pullulans and Dothichiza pithyophila) in a laboratory test according to the EN 152 procedure. Afterwards, the same samples were artificially weathered and re-exposed to the same blue stain fungi for the second time. The purpose of this experiment was to investigate the synergistic effect of weathering and staining. The broader aim of the study was to determine the correlation factors between artificial and natural weathering and to compare laboratory and field test data of fungal disfigurement of various bio-based materials. During the four years of exposure, the most prominent colour changes were determined on decking. Respective changes on the façade elements were significantly less prominent, being the lest evident on the south and east façade. The results showed that there are positive correlations between natural weathering and the combination of artificial weathering and blue staining. Hence, the artificial weathering of wood-based materials in the laboratory should consist of two steps, blue staining and artificial weathering, in order to simulate colour changes.

scholarly journals Research on the Role of Situational Teaching in Second Language Teaching

2019 ◽  
Vol 3 (2) ◽  
pp. 59
Author(s):  
Lijuan Gao
Keyword(s):  
Second Language ◽  
Teaching Method ◽  
Language Teaching ◽  
Language Skills ◽  
Colleges And Universities ◽  
Language Ability ◽  
Second Language Teaching ◽  
The Times ◽  
Different Levels

<p>With the development of society and the progress of the times, it is very important for people to master a second language. Nowadays, the development of our country is becoming more and more international. Under such an environment, the application of second language is becoming more and more popular. At present, various colleges and universities have listed second language as a compulsory course, mainly to attract students' attention. In the process of second language teaching, in order to effectively enhance students' language skills and promote the teaching results of second language, the author believes that language teaching and situational teaching should be fully combined to effectively enhance students' second language ability. On this basis, the application of situational teaching method in second language teaching is discussed and analyzed in details from different levels.</p>

Formation of Green Pigment and Colour Changes in Orthoptera

1953 ◽  
Vol 44 (2) ◽  
pp. 299-315 ◽  
Author(s):  
Salâhattin Okay
Keyword(s):  
Fat Body ◽  
Colour Change ◽  
Blue Pigment ◽  
Breakdown Product ◽  
Bile Pigment ◽  
Green Pigment ◽  
Yellow Colour ◽  
Blue Component ◽  
Colour Changes ◽  
Background Reaction

The colour change and formation of green pigment in Mantis, Acrida, Locusta, Schistocerca and Dixippus are studied.There is no background reaction to green and brown or yellow colour in these species.Usually the young nymphs of Mantis are green; some ofthe old nymphs and adults have a tendency to lose the green pigment. Phytophagous nymphsbecome green only when fed on fresh or growing grass. Green individuals may be obtained in darkness on this food (Locusta). The green pigmentdisappears on a diet of dry grass.The colour change from non-green to green, or vice versa, is dependent on the formation or disappearance of the blue component (bile pigment-protein) of green pigment. The blue pigment generally appears first in the blood and is deposited in the integument at the following moult; it does not appear to be a breakdown product of chlorophyll or haematin. It is probably synthesised from a colourless precursor in the peripheral fat body.Observations made on the pericardial cells of Locusta suggest that the blue pigment may be converted into insectorubin.

scholarly journals A modified metabolic inhibition test for the titration of poliovirus neutralizing antibodies

1961 ◽  
Vol 59 (3) ◽  
pp. 295-302 ◽  
Author(s):  
Marjorie V. Mussett ◽  
Mileva Dimic ◽  
Nermin Ege ◽  
J. O'H. Tobin
Keyword(s):  
Statistical Analysis ◽  
Neutralizing Antibodies ◽  
Technical Assistance ◽  
Colour Change ◽  
Enteric Viruses ◽  
Metabolic Inhibition ◽  
Inhibition Test ◽  
Virus Activity ◽  
Colour Changes ◽  
Initial Medium

A modification of the metabolic inhibition test for titrating poliomyelitis antibody is described. The method depends on the substitution of galactose for glucose in the initial medium to eliminate colour change during the period of virus activity. Neutralization is detected by the addition of glucose at the end of the period, when the usual colour changes associated with this type of test occur. A statistical analysis of the results obtained is given.This method can also be used for titrating antibodies to other enteric viruses.Thanks are due to Dr Hélène Mair, Dr D. R. Gamble and Dr A. D. Macrae for strains of enteroviruses, and to Miss Patricia Jerram, for valuable technical assistance in the early days of this work.

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