Quantitative (?morphological?) colour changes on prolonged black and white background adaptations of the minnowPhoxinus phoxinus (L.) and the effects of chromatic spinal section on these colour changes

1972 ◽  
Vol 77 (2) ◽  
pp. 170-189 ◽  
Author(s):  
R. U. Ahmad
Keyword(s):  
White Background ◽  
Black And White ◽  
Colour Changes ◽  
Spinal Section

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.

Comparison of Noninvasive Tear Break-up Time Measurements from Black and White Background Instruments

2004 ◽  
Vol 81 (6) ◽  
pp. 436-441 ◽  
Author(s):  
PAULINE CHO ◽  
KWAI-YING HO ◽  
YEUNG-CHI HUANG ◽  
HON-YEE CHUI ◽  
MAN-CHUI KWAN
Keyword(s):  
White Background ◽  
Black And White ◽  
Break Up

THE RELATION OF ENDOGENOUS MELANOPHORE-EXPANDING HORMONE TO HYPERGLYCAEMIA IN XENOPUS LAEVIS

1957 ◽  
Vol 15 (2) ◽  
pp. 190-198 ◽  
Author(s):  
K. A. MUNDAY
Keyword(s):  
Xenopus Laevis ◽  
Blood Sugar ◽  
Water Injection ◽  
White Background ◽  
Glycaemic Response ◽  
Effective Agent ◽  
Black And White ◽  
Lower Blood ◽  
Effective Level ◽  
Sugar Levels

SUMMARY 1. Xenopus laevis responds to injected adrenaline by an increase in the level of blood sugar. This increased blood sugar is apparently derived from liver and not from muscle glycogen. 2. Blood-sugar levels of Xenopus equilibrated on a black background (BB) and on a white background (WB) are statistically different throughout 6 months' starvation (P<0·05). On prolonged starvation for 14–16 months the lower blood-sugar level recorded in WB animals is not statistically different from that in BB animals (P> 0·10). 3. Xenopus shows a marked excitation hyperglycaemia, which is thought to be due to secretion of endogenous adrenaline. This hyperglycaemia is greatest in animals kept on a white background. 4. Xenopus equilibrated on black and white backgrounds show different hyperglycaemic responses to similar doses of adrenaline (P < 0·01). Compared with their own 'control-distilled water injection' levels, WB animals show an increase of blood sugar 40% higher than BB animals. 5. If melanophore-expanding hormone ('B') is an effective agent in decreasing the hyperglycaemic response to adrenaline, the greater effective level of circulating hormone in BB animals, together with their relatively reduced glycaemic response, supports the view that endogenous 'B' hormone plays a role in normal carbohydrate metabolism.

The impact of varying warning color on e-cigarette advertisements: Results from an online experiment among young adults

2021 ◽  
Author(s):  
Jessica L King ◽  
Connor Simper ◽  
Jacob Razzouk ◽  
Julie W Merten
Keyword(s):  
Young Adults ◽  
Tobacco Use ◽  
Future Research ◽  
White Background ◽  
Chi Square ◽  
Message Effectiveness ◽  
Black And White ◽  
Black Background ◽  
Downstream Effects ◽  
The Impact

Abstract Introduction Advertisement warnings are often overlooked, which reduces the opportunity for risk communication. Methods We used Prolific to survey 1,131 young adults (18-35) who currently used e-cigarettes or tobacco products. We randomized participants to one of four warning conditions: black text on white background (BW), white on black (WB), black on yellow (BY), and yellow on black (YB). We examined associations between condition and attention, recall, ad appeal, perceived message effectiveness (PME), and intentions to use e-cigarettes using chi-square and ANOVA where appropriate. We conducted logistic regressions by condition for attention and recall controlling for demographics and tobacco use. Results The warning was selected as the most attention-capturing area of the advertisement more often by those exposed to yellow warnings than white (59.9% versus 46.8%), even after controlling for demographics and tobacco use (p&lt;.05). Recall was greater among those exposed to yellow warnings than white (44.2% vs. 37.3%), which held in controlled models. There were no significant differences between yellow and white warnings for ad appeals, PME, or intentions to use. In subanalyses, WB warnings generated higher PME (10.1 vs. 9.5) and lower intentions to use e-cigarettes (3.0 vs. 3.3) than BW (each p&lt;.05). Conclusions Yellow warning color increases attention and recall of the warning, but this increase in attention did not translate to differences in downstream effects. Among currently mandated warning variations, the white text on black background warning appears more effective than the black on white. Future research should examine whether differences translate to behavior change. Implications We tested color variations of the FDA-mandated nicotine text warning on e-cigarette advertisements. Yellow variations (yellow text on black background and black on yellow) better captured attention and increased warning recall compared to the mandated black and white warnings. Among the FDA-mandated black on white and white on black warnings, the white on black variation appears more effective, generating higher perceived message effectiveness and lower intentions to use e-cigarettes. Given the difficulty in implementing pictorial warnings in the US, color might represent an alternative to improve warning effectiveness. Findings may also be applicable to those designing tobacco-related health communications.

Effects of Illumination on Behavior of Wild Brown (Salmo trutta) and Rainbow Trout (Salmo gairdneri) Exposed to Black and White Backgrounds

1973 ◽  
Vol 30 (12) ◽  
pp. 1875-1880 ◽  
Author(s):  
John A. Ritter ◽  
Hugh R. MacCrimmon
Keyword(s):  
Rainbow Trout ◽  
Salmo Trutta ◽  
Salmo Gairdneri ◽  
White Background ◽  
Activity Levels ◽  
Sudden Increase ◽  
Experimental Tank ◽  
Protective Response ◽  
Black And White ◽  
Selection Of

Wild brown (Salmo trutta) and rainbow trout (Salmo gairdneri) placed in a circular tank illuminated at 10−2 lx immediately selected black rather than white background. Preference for black fluctuated with activity during the first 2 hr while both selection of black and activity gradually decreased with habituation over the following 84 hr. A sudden increase in illumination to 200 lx reestablished the strong selection of black which decreased rapidly with rising activity. Selection of black was inversely correlated with activity of the fish and was greater under moving than nonmoving water conditions. Differences in activity levels between rainbow and brown trout caused minor differences in response to background.Temporal preference for black background is interpreted as a protective response to the fright stimuli of initial handling, unfamiliarity with the experimental tank, and sudden increase in illumination. Duration of the response after the sudden increase in illumination was less in brown than rainbow trout. Because of its influence on activity and selection of light or dark backgrounds, light is an important ecological factor for trout.

Test of Relative Translucency of 5 All-Ceramic Core Materials

2013 ◽  
Vol 591 ◽  
pp. 289-292
Author(s):  
Jian Feng Chen ◽  
Rui Jie Dang ◽  
Li Sheng Zhao ◽  
Bin Deng ◽  
Bin Gu ◽  
...  
Keyword(s):  
Color Difference ◽  
Core Material ◽  
White Background ◽  
Ceramic Core ◽  
Black And White ◽  
Significant Difference ◽  
All Ceramic ◽  
Core Materials

Objective:To study the relative translucency of 5 veneered and glazed all-ceramic systems core material, including Procerra AllCeram Alumina, Vita In-Ceram Zirconium, Ivoclar Vivodent Empress, In-Ceram Spinell and Colored Zirconia. Methods: Under standard black and white background, the surface light reflectivity of 5 veneered all-ceramic systems core material was determined with contact color difference meter, and the ratio of Yb /Yw was calculated. Results: After veneered, the relative translucency of 5 core materials all declined, and ranged from 0.6740 of In-Ceram Spinell to 1.00 of In-Ceram zirconia, among of that In-Ceram Spinell was most transparent. Conclusion: Among the groups, there is no significant differences among Empress II, Procera AllCeram and Colored Zirconia (IL1,IL2,IL3). Compared with Procera AllCeram and Vita In-Ceram Zirconium , Procera AllCeram has significant difference. There is a significant difference between Procera AllCeram and In-Ceram Spinell.

A Simple and Rapid Method of Adding Color to Photographic Projection Materials

1974 ◽  
Vol 32 ◽  
pp. 118-119
Author(s):  
Jack A. Horner ◽  
Catherine Pennington
Keyword(s):  
Rapid Method ◽  
White Background ◽  
Cover Glass ◽  
Color Film ◽  
Black And White ◽  
Colored Paper ◽  
Short Time

It is becoming quite popular to utilize some colored materials with projection slides which would otherwise be black and white. For example, one might wish to show a black table or graph on a blue rather than a white background. Such presentations are aesthetically pleasing, reduce eye strain and glare, and add clarity to a presentation. There are several methods commonly used to achieve the colored effect. Perhaps the most obvious method would be to prepare the material on colored paper and photograph it with color film. This method is expensive, time consuming and precludes the use of already prepared black and white slides on file. Another method often used is to sandwich a colored theatrical gel between the cover glass. This generally results in wrinkling of the gel and makes the use of multiple colors difficult. Still another method utilizes photo water colors intended for print tinting but suffer from severe fading in a relatively short time.

Discrimination of closed shapes by two species of bee, Apis mellifera and Megachile rotundata

2002 ◽  
Vol 205 (4) ◽  
pp. 559-572 ◽  
Author(s):  
Raymond Campan ◽  
Miriam Lehrer
Keyword(s):  
Apis Mellifera ◽  
Template Matching ◽  
Discrimination Performance ◽  
Luminance Contrast ◽  
Image Motion ◽  
White Background ◽  
Megachile Rotundata ◽  
Black And White ◽  
Matching Process ◽  
Motion Contrast

SUMMARY In the present study, the performance of two bee species, the honeybee Apis mellifera and the leaf-cutter bee Megachile rotundata, in discriminating among various closed (convex) shapes was examined systematically for the first time. Bees were trained to each of five different shapes, a disc, a square, a diamond and two different triangles, all of the same area, using fresh bees in each experiment. In subsequent tests, the trained bees were given a choice between the learned shape and each of the other four shapes. Two sets of experiments were conducted with both species. In the first, solid black shapes were presented against a white background, thus providing a high luminance contrast. In the second, the shapes carried a random black-and-white pattern and were presented 5 cm in front of a similar pattern, thus producing motion contrast, rather than luminance contrast, against the background. The results obtained with the solid shapes reveal that both bee species accomplish the discrimination, although the performance of the honeybee is significantly better than that of the leaf-cutter bee. Furthermore, the effectiveness of the various shapes differs between the two species. However, in neither species is the discrimination performance correlated with the amount of overlap of the black areas contained in the various pairs of shapes, suggesting that, in our experiments, shape discrimination is not based on a template-matching process. We propose that it is based on the use of local parameters situated at the outline of the shape, such as the position of angles or acute points and, in particular, the position and orientation of edges. This conclusion is supported by the finding that bees of both species accomplish the discrimination even with the patterned shapes. These shapes are visible only because of the discontinuity of the speed of image motion perceived at the edge between the shape and the background.

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