Search

A number of organic compounds have been screened as reagents for the spectrophotometric determination of small amounts of selenium. 4,5-Diamino-6-thiopyrimidine shows promise for this determination. In ammoniacal solution, even on long standing, this reagent is colourless in the presence of quadrivalent selenium. However, at pH 1.5–2.5 or lower, 4,5-diamino-6-thiopyrimidine forms a yellow colour with quadrivalent selenium, and this has a strong absorption peak at 380 mμ when compared with a reagent blank of the same concentration. Beer's Law holds when the selenium concentration is between 0.1–2.5 μg per ml. The conditions for the quantitative determination of selenium have been investigated. When selenium in solution is in the quadrivalent state, measurement of absorption should be carried out within 30 min of the addition of the reagent. On longer standing, the reagent gives a slight yellow colour with the formation of elemental selenium. The formation of elemental selenium is slow in dilute solutions of selenium.

Two batches of analytical grade ZnO powder (ZnON) are heated to 920 °C and one, (ZnOA), quenched to room temperature, and the other, (ZnOB), cooled slowly. Samples of both ZnOA and ZnOB are afterwards heated for one hour at temperatures between 100 and 800 °C and quenched. From all these samples the amount of free zinc is determined and the reflection and luminescence spectra measured. The reflection spectra with ZnON as blank indicate the presence of a supplementary absorption band having an intensity which depends upon the previous treatment. From this variation and correlation with the amount of free zinc the yellow colour of the samples can be explained and new models for the centres deduced. Zwei Teile analysenreines ZnO-Pulver (ZnON) wurden bis 920 °C erhitzt. Der eine Teil wurde auf Zimmertemperatur abgeschreckt (ZnOA), der zweite Teil langsam abgekuhlt (ZnOB). ZnOA- und ZnOB-Proben wurden danach fur eine Stunde bei Temperaturen zwischen 100 und 800 °C erhitzt und abgeschreckt. Bei allen Proben wurden der Gehalt an freiem Zin bestimmt und die Reflexions- und Lumineszenzspektren untersucht. Die Reflexions-Spektren bei ZnON gestatten neben der b-Bande eine zusatzliche Absorptionsbande festzustellen, deren Intensitat von der Vorbehandlung abhangt. Aus dieser Anderung und ihrer Beziehung zur Menge freien Zinks konnte die gelbe Farbe der Proben gedeutet und ein neues Modell fur diese Zentren hergeleitet werden.

If birds reared in isolation learn visual features of their own bodies, they could generalize from such learned perceptions and choose to associate with members of their own species rather than with other species when subsequently placed with other animals. This self-perception hypothesis could account for some published studies showing preferential choice of own species by birds reared in isolation. A series of experiments was conducted to test this hypothesis. Typically, newly-hatched chicks were dyed red, or green, or were left their natural yellow colour. After being reared for 8 days in visual isolation or in small social groups, the chicks were tested in a three-choice test apparatus for their approach to red, green, and yellow chicks. A chick was scored for a choice if it reached a goal-box and tried to push through the separating wire-mesh. In Experiment I, red and green chicks, reared socially or in isolation, were tested for their choice of red, green, and empty goals. The socially-reared chicks clearly chose goal chicks of their own colour. The isolate-reared chicks responded in an indiscriminate manner. In Experiment 2, chicks of the natural yellow colour were used along with red and green ones. Again, social-chicks chose goals of their own body colour, while isolate chicks responded indiscriminately. Some generalization appeared to occur in the social-chick responses, particularly between green and yellow, with green and yellow chicks clearly avoiding the red goal. To a lesser extent, red was generalized to yellow, so that red chicks avoided the green rather than the yellow goals. In Experiment 3, newly-hatched yellow chicks responded to red, green, and yellow goals indiscriminately, showing that they have no innate companion-colour preference. However, 8-day isolate-reared yellow chicks behaved like 8-day social-chicks and avoided red goals in favour of green and yellow ones. Experiment 4 tested an hypothesis that isolate-chicks learn their own colour from their reflection in their drinking water. Green and yellow chicks, reared in isolation for 8 days with no drinking water (which was administered by pipette directly into the crop, either in light or in darkness), failed to show any tendency to choose green and yellow goals preferentially to red and empty goals. In Experiment 5, chicks coloured red, yellow or green were reared in mixed groups; one chick of one colour with two companions of another colour. In this way chicks experienced companions either of one, or of two, colours. The tests at 8-days showed that when two colours had been experienced either colour may be chosen, but that green was more often chosen than might have been expected. It appeared that green was most, and red least, readily learned and responded to. The 'natural' yellow colour tended to be confused with green. Experiment 6 tested for the possibility of individual recognition in 8-day social-chicks by using cage-mates in one of the goals. Responding was indiscriminate in yellow chicks tested in this way with yellow goal chicks. Taken together, these experiments show that newly-hatched chicks have no preference for red, yellow, or green chicks, but that they learn the colour of their companions and selectively approach them by 8-days of age. These results are compared with the published work on colour and approach and following responses in chicks. In general there seems to be more evidence against colour preferences in such responses in newly-hatched chicks. The apparent stronger preference shown by chicks that have experienced colours at the extremes of the visible spectrum could be due to the greater possibilities for generalization in birds trained to colours in the middle of the spectrum. In any event, there seems no doubt that the colour of the companion is learned. The self-perception hypothesis was not supported by the results of Experiments I and 2. However, if the colour groups are combined in Experiment 2, the isolate-chicks appear to have chosen their own body-colour significantly more than would be expected by chance. Furthermore, in Experiment 3 yellow isolate-chicks clearly avoided red goals. It appears, then, that isolates can develop a weak tendency to choose colours not too different from their own body-colour. Experiment 4 showed that such a tendency did not develop if the chicks were not able to see their own reflection. It must be concluded, therefore, that the self-perception hypothesis is tenable at least if perception through reflection in water is included. It is not known whether, in the absence of reflected self-images, such a tendency would develop over a longer period of time through the bird seeing its own body directly. This conclusion is discussed in relation with published studies of species and familial recognition in birds reared in isolation or in the company of other breeds or species.

An investigation, into the determination of traces of boron as boric acid by development of a yellow colour with morin in an anhydrous solution of tartaric acid in acetone, has been carried out. It has been shown that boron can be estimated accurately over the range 20 to 200 μg boron, using a photometric method. Factors influencing the development of the colour reaction have been examined and discussed.

Measurements on photoemitted electron distributions from Cu, Zn and β'-CuZn up to 21 eV photon energy are reported. It is found that the Cu d-band is 0.9 eV lower relative to the Fermi level in β'-CuZn than in pure Cu and the width is only slightly smaller. The Zn d-band however has essentially the same position in both Zn and β'-CuZn. It is shown that the Cu d-states are responsible for the yellow colour of β'-CuZn rather than the conduction states as has been previously proposed.

The changing properties of the outer layers of the cuticle ofPeriplanetaduring preparation for phenolic tanning are due to the passage into them, by different routes, of a lipoid and a protein. Both inner and outer zones of the pre-exuvial endocuticle become impregnated, but the final concentration of the lipoprotein mixture is much greater in the outer zone than in the inner. The lipoid is a sterol which imparts a yellow colour to the cuticle, and the protein is rich in phenolic groups owing to the presence of tyrosine. The isoelectric point of the protein is similar to that of tyrosine.

It has been known for some time that Penicillium citrinum Thom when grown on suitable media produces a characteristic lemon yellow colour. Thus Thom in his monograph on “Cultural Studies of species of Penicillium ” (1910), says, “ P. citrinum produces a lemon yellow colour, soluble in alcohol, in media containing sugars, milk, gelatin, bread and potato.” This colouring matter was not isolated, however, nor was its nature further investigated. In the course of an investigation into the colour reactions given with ferric chloride by metabolism solutions produced by various species of Penicillium , it was found that a very characteristic reaction was given by each of the strains of Penicillium citrinum THOM in our possession, but was not given by any other species in pure culture whether of Penicillium or of any other genus tested.

Ancient wheat species (einkorn, emmer, spelt and Khorasan wheat) have been suggested to have health benefits when compared with modern cultivars of bread and durum wheat. Although limited data are available on the contents and compositions of bioactive components in ancient wheat species, reported studies show that they differ little from modern wheat species in the contents of most bioactive components, and may be lower in some components (such as dietary fibre). Although einkorn, emmer and Khorasan wheat all have higher high contents of the carotenoid lutein than bread wheat, durum wheat is also rich in lutein due to selection for yellow colour. These reported analyses do not support the suggestion that ancient wheats are generally more “healthy” than modern wheats.

Natural products such as pure phytoconstituents and plant extracts offer limitless opportunities for the new drug development due to its unmatched chemical diversity. Plants play an important role in the medicinal preparations for both preventive and curative purpose. Some of the currently available drugs i.e. aspirin, digitalis, anti-malarial (quinine) and anti-cancer (vincristine, vinblastine) were derived from the plant sources. Aloin (C 21 H 22 O 9 ), a yellow colour compound is a mixture of two diastereoisomers, aloin A and aloin B. Aloin is an anthrone C-glucoside having molecular weight 418, and it is the main phytoconstituents of aloes. Aloin is used for various pharmacological purposes such as laxative agent. It is also used as ingredients of various laxative pharmaceutical preparations. So far, varieties of analytical methods have been developed for the estimation of aloin in aloes product, which are mainly based on HPLC and TLC techniques. In the present review, pharmacological activities and analytical aspects of aloin were highlighted along with some useful tissue culture techniques. This review could be helpful to the researcher for the investigation of new molecule from aloin in the future.

This study aims at identification of gender-based colour differences among 7-9 years old children at single- gender schools in an Islamic country. This will help to better understand the effects of certain educational environments on children's tendencies towards specific colors. In this study multi-stage cluster sampling was applied to select a total of 100 students (50 boys and 50 girls) among 7-9 years old children chosen from one all- boy and one all-girl elementary schools. The color preference in children was evaluated based on Luscher colour test and the results were analyzed according to Uman-Vitni and Kruskal-Wallis nonparametric tests. It is found that a significant difference exists between boys and girls tendencies towards four colours including blue, green, pink and black. In addition, it is observed that with age, children preference in yellow colour will vary considerably with their age.

A colorimetric spot test was developed to monitor the accumulation of oxidative products in heated oils. To test the oil, a drop was placed on a silica-gel covered slide which had bromocresol-green incorporated into the gel. The colour range developed by several oils was from blue to an intense yellow colour. A comparison of the spot test with silica-gel chromatography showed that oils containing 4, 10 and 20% or more of altered triglycerides developed blue, green and yellow colours, respectively. The simplicity and rapidity of the spot test enables food processors to rapidly assess the state of the oil and prevent the sale and distribution of food with a high content of thermally oxidized products.

SummaryAlthough the pigments of pollen responsible for its yellow colour, and also for the absorption of long-wave UV light, attracted foraging honeybees to pollen sources in the flight room, they appeared not to be directly associated with the substance(s) that attracted bees in the hive to eat the pollen fed to them.

The gradual disappearance of the yellow colour of ferricyanide with the addition of vanadyl ions in alkaline medium has been made the basis of the quantitative determination of both vanadium and ferricyanide. The colorimetric titrations were carried out with the aid of a Hilger Spekker Absorptiometer with a blue filter having maximum transmission in the range of 450–500 mμ. It is shown that the accuracy of the results compares favourably with those obtained by other standard procedures.

A fine yellow clay which occurs in Jersey and in at least some of the other Channel Islands has received little attention from geologists, and the few who have noticed it appear to have considered it merely the result of local weathering. This clay is more or less sandy, and though generally of a dull yellow colour, is sometimes reddish orange. On microscopic examination many of the grains are seen to be somewhat rounded, but the majority of them have sharp angles. In one or two situations the clay effervesces freely with acids, and at some places on the coast it has been found to coat the grass roots with a pipe-like covering. On a small detached island on the south-east coast it contains fantastically-shaped concretions like the “ Mannchen ” of the Rhenish loss. This, however, is probably due to the fact that above the clay at this point there is a bed of shells, all modern, from which carbonate of lime has been washed down by rain. Sometimes the clay exhibits obscure marks of bedding, and at one point in the town of St. Helier, where an excavation had been made for relaying some drains, I noticed distinct lamination. Mr. Green, a well-sinker, has also told me that, in sinking wells, he has often noticed distinct stratification. The lower part of the clay often contains angular stones, sometimes grouped together pretty closely, sometimes at some distance from each other, while occasionally a single stone, or one or two, may be

The yellow colour of the heartwood of Atherosperma moschatum Labill. (Tasmanian sassafras) is due principally to the presence of the alkaloids spermatheridine (I) and atherospermidine (II) ; atherosperminine (III) was the only other alkaloid isolated.

When trigonelline is heated with alkali, methylamine is split off and the remaining dialdehyde, formed by ring opening, is conjugated to aniline in acid medium. A yellow colour appears almost instantly, suitable for colorimetric determination. No turbidities occur, the colour is sufficiently stable in full daylight and 10 γ per ml can be determined with an accuracy of about 5%.

Dicyclohexylamine is determined in sodium cyclamate at levels of concentration down to the order of 1 ppm by measurement of the yellow colour of the chloroform extract of its Bromophenol Blue complex.

A precise and specific method for the determination of L-ascorbic acid in the presence of dehydro-L-ascorbic acid and 2,3-diketo-L-gulonic acid has been developed. The method is based on the reaction of phenylhydrazinium chloride with ascorbic acid in 0·1 N hydrochloric acid at a temperature of 50 ± 2 °C. The stable yellow colour produced is measured spectrophotometrically at 395 nm. The results obtained by this method and the B.P. method are compared. There is no interference from other vitamins, minerals, glucose, sucrose or the most commonly used excipients with this method and it has been successfully applied to pharmaceutical preparations. The simplicity of the procedure permits rapid analysis, which is necessary for routine control work.

Maurice Raynaud (39) provided the first accurate clinical description of the condition that now bears his name: Madame X, aged 26 years, has never been ill; but she has been the subject since childhood of an infirmity which makes her an object of curiosity to her acquaintances. Under the influence of very moderate cold, and even at the height of summer, she sees her fingers become exsanguine, completely insensible, and of a whitish yellow colour. This phenomenon happens often without reason, lasts a variable time and terminates by a period of very painful reaction, during which the circulation is re-established little by little and return to the normal state. Madame X has no better remedy than shaking her hands hard, or soaking them in lukewarm water....This state, which I dare hardly call a disease, is local syncope in its simplest form. [As quoted by Birnstingl (1)]

Preparative organic reactions rarely give a complete conversion of the starting material into the required product. In a good ‘synthetic’ reaction a yield of product of 70–80% or more would be expected, but in addition there may be small amounts of other organic materials formed as by-products. In some cases reactions also produce polymeric ‘tarry’ material, which may be a brown or yellow colour. In addition to these organic products, many reactions also produce equimolar amounts of inorganic products, e.g. the metal halides produced in a typical ether synthesis: $$\textup{RCH}_{2}\textup{Br}\ +\textup{NaOCH}_{3}\rightarrow \textup{RCH}_{2}\textup{OCH}_{3}\ +\textup{NaBr}$$

Potassium trithiocarbonate is used as reluctant for the titrimetric determination of thiuram disulphides in dimethylformamide—water media. The method is based on reductive cleavage of the disulphide linkage to yield the corresponding dithiocarbamates. In visual titrations, the end-point is marked by appearance of a yellow colour with the first drop of reagent added in excess. The method is simple, accurate, reliable and of wide applicability. It has been successfully extended to the analysis, in the same sample solution, of thiuram disulphide-dithiocarbamate mixtures.

Eyes of a green or yellow colour, a flow of bile in the urine, white excrement the colour of the food that is taken: all these are counted evidence of the jaundice, engendered by infarction of the liver, scirrhus or inflammation: or else the gallbladder contains thick bile, not readily excreted, or else a stone or tumour which the bladder is unable to pass. Or the bile, in the crisis of high fevers, traverses the pores of the skin: or dire poison is drunk, like the venom discharged from the teeth of vipers. Sometimes the jaundice is black, the skin dry and dark in hue: there is fear and oppression, distress in sleep and melancholy by day: this is a black humour that is caught up in the vessels, not excepting the spleen.

3-Amino-2-piperidone, a δ-lactam of ornithme, has been detected in the urine of a number of patients with hyperomithinemia. The distinctive yellow colour formed with a ninhydrin-cadmium reagent should help in the detection of hyperomithinemia by urinary chromatography.

A colorimetric method for the determination of iota-carrageenan is described, based on the measurement of the yellow colour developed by the reaction of the 3,6-anhydro-D-galactose residue with 2-thiobarbituric acid and hydrochloric acid. The method has a sensitivity equivalent to 0·01 mg ml–1 of carrageenan and can also be used to determine carrageenan in blood and urine in concentrations of 0·02 and 0·01 mg ml–1, respectively. The method has advantages of sensitivity, relative specificity, a small sample-volume requirement and convenience over previously published methods for the determination of sulphated polysaccharides, thus providing a means of extending quantitative biological investigations of this group of substances.

MANY insects contain carotenoid pigments1, and some notable examples are found in the Coleoptera, where carotenoids are responsible for the yellow colour of the yellow and black striped wing cases of the Colorado beetle, Leptinotarsa decemlineata, and the orange-red colour of the ladybird beetles, Coccinella spp. There has, however, been no report of any insect species being able to synthesise carotenoids de novo, and it is generally accepted that in insects, as in other animals, any carotenoids present are of dietary origin2. In July 1976 the Liverpool area, like many regions of the UK, experienced an invasion by enormous numbers of ladybirds, almost entirely of the seven-spot variety, Coccinella septempunctata. With such large numbers of insects available we were able to use modern analytical techniques to identify the carotenoids of these beetles. We report here that the carotenoids identified were mostly hydrocarbons, and the carotenoid pattern indicated that these pigments in the ladybird are likely to be of microbial rather than plant origin, thus suggesting the involvement of symbiotic microorganisms.

A histochemical method is described to demonstrate tissue proteases with chromogenic substrates. The tissue sections are placed upon a thin agar film containing the dissolved substrates. After incubation the developed yellow colour is transformed into a red stain. Tissue proteases of various organs were microscopically localizated and compared with the fibrinolytic activity of the specimens on plasminogen containing fibrin slides.

A relatively quick and simple procedure is described for the detection of N-nitrosodiethanolamine in various cosmetic products. The procedure is based on the irreversible formation of p-nitroso-N,N-dimethylaniline which has a bright yellow colour in basic solution. The compound is formed following extraction of the cosmetic, photolysis of the aqueous extract and the addition of N,N-dimethylaniline to photolysed extract.

Oxidation products of manganese react with o-tolidine to produce a yellow colour, which can be utilised for the photometric determination of manganese. Prior to the determination, divalent manganese is converted into the higher valency forms by oxidation with atmospheric oxygen in alkaline solution in the presence of magnesium and iron(III) salts.

The title esters are effective acylating agents in solid phase peptide synthesis; completion of acylation is indicated by fading of the transient yellow colour produced by ionisation of the liberated hydroxy component.

IN Roth and Schuster's method1 for colorimetric determination of tryptophan in vegetable matter, the measurement of the yellow colour is made with a Pulfrich Stufenfotometer with filter S 43. The method has often been used, but I have been unable to find any published account of the measurements made spectrophotometrically. I have therefore tested the method for some cereals, etc., by means of a Beckman spectrophotometer, model D.U.

ON February 25, about 7.30 p.m., I chanced to see, at Coombe, near Woodstock, Oxfordshire, a globular meteor start from the Pointers, and fall with a slightly northerly inclination. When it was near the horizon, my garden wall hid from my sight the close of its brilliant career. Big as Venus at her brightest, it was substantially of a yellow colour, but shot over with flashes of glowing scarlet.

Introduction Raynaud provides us with an accurate clinical description of the disease which now bears his name. 'Madame X, aged 26 years, has never been ill; but she has been the subject since childhood of an infirmity which makes her an object of curiosity to her acquaintances. Under the influence of very moderate cold, and even at the height of summer, she sees her fingers become exsanguine, completely insensible, and of a whiteish yellow colour. This phenomenon happens often without reason, lasts a variable time and terminates by a period of very painful reaction, during which the circulation is re-established little by little and returns to the normal state. Madame X has no better remedy than shaking her hands hard, or soaking them in lukewarm water.... This state, which I dare hardly call a disease, is local syncope in its simplest form' (1862). Raynaud clearly recognized the vasospastic nature of this phenomenon in young, healthy women and in a later paper (1874) he put forward 'the hypothesis of a contraction of the terminal vascular ramifications, varying from a simple diminution of calibre up to complete narrowing of the lumen of the vessel. To the total closure of the arterial and venous vessels would correspond an exsanguine and cadaveric state of the extremities ... whilst the arterioles only being closed and the venules open, one would see a venous stasis produced by failure of vis a tergo, whence the cyanosis and livid ap. pearance'. Unfortunately he failed to understand the widely varying pathology of the examples he described, or that necrosis or frank gangrene can only result from actual structural obliteration of the vessels and it was left to Jonathan Hutchison (1901) to point out the many different diseases which are liable to present with digital ischaemia. Hutchison also advocated the term 'Raynaud's phenomenon' to describe the intermittent episodes and showed that these could be due either to vasospasm or organic obstruction, although even today this distinction remains difficult on clinical grounds alone.

A deep yellow colour is formed by the reaction with phenol and chloramine-T in the presence of copper, and this reaction is used for the photometric determination of copper. An aqueous solution of copper and the reagents at pH 11.5-11.6 is heated. The molar absorptivity at 410 mmu, is 2.32 x 10(6). The method has been used satisfactorily to determine ultram amounts of copper in high-purity silicon.

n/a

The method for the assay of β-galactosidase introduced by Lederberg (1950) was modified and used for studies of the enzyme in the soil.o-Nitrophenyl-β-d-galactoside served as substrate. Trismaleinate buffer was found to be more suitable than phosphate buffer in the assay. The enzyme reaction was stopped by adding sulphuric acid and the incubation mixture was alkalized with sodium carbonate so that the yellow colour ofo-nitrophenol could develop. The method is sensitive and specific and requires small quantities of soil and a short incubation time.

Thin films of various rubbers have been examined in a Siemens Elmiskop I. The materials used were all originally unvulcanized. They were dissolved in benzene and specimens were prepared in the following way: a drop of solution was allowed to fall on a clean water surface where it spread and — after evaporation of the solvent — left a floating rubber film. This was then picked up on a specimen grid brought through the water surface from below. It was found that the thickness of the rubber film was critical. If the film was too thick the resolution suffered, but if too thin it broke into a web of fine filaments. There was an intermediate thickness for which the film was coherent but had thin patches which were suitable for electron microscope examination. Such films could be obtained by using a solution of strength about 10 g/l, but it was found best to judge the film thickness by the interference colour and dilute the solution accordingly. Films which showed low order white with veining of yellow colour were suitable: the average thickness was then about 1000 A, but there were thin patches which were probably less than 100 A thick.

IN her letter to NATURE of March 24 Miss I. Sollas remarks on the “canary-yellow” colour “in members of the stoat family when the winter whitening is incomplete,” adding, “there can thus be little doubt that the yellow body produced artificially in the fur of the albino rat is a substance similar to the yellow pigment of the stoat's winter coat. … I do not know whether it has been recorded, though I should have thought so, that a stoat's fur of the purest white will, after exposure to light in a museum case for a time, varying with the intensity of the light, invariably turn distinctly yellow—fainter, however, than “canary-yellow.” I have made no chemical or microscopical examination of fur so yellowed, but the usual reason assigned for the change is the absorption by the hairs of a small amount of fat out of the skin, induced by the light and heat of summer. I understand, also, that ermine kept in a dark chamber or box the temperature of which is high will also turn yellow. Stoats in this part of the country often become white early in the season before any real cold weather has occurred.

A simple and quickly performed colour test is described, in which organisms containing catechol 2:3-oxygenase (meta-pyrocatechase) produce from catechol a yellow coloured intermediate, α-hydroxymuconic semialdehyde. The yellow colour is produced most consistently, rapidly and intensely by 2–4 day old cultures from 2·7–27 mM solutions of catechol. The purple-brown colour produced by some organisms is discussed. Using growth from nutrient agar plates, the test was applied to cultures of 239 Gram negative bacteria; all of the 64 cultures which gave a positive result had been in contact previously with aromatic substrates and many of them could oxidize phenol. The significance of a positive reaction is discussed briefly.

1. 1. Tumours in the opercular region of cod have been examined histopathologically. 2. 2. The growth pattern and the similarity between some of the tumour cells and the acidophilic cells of the covered pseudobranch show that these tumours probably have originated in the pseudobranch. 3. 3. The similarities between the present tumours and human carcinoids (e.g. yellow colour, infiltrating potentialities, mosaic growth pattern, lipoid-rich, argyrophil/argentaffin cytoplasmic granules) and the present findings make it probable that the covered pseudobranch normally has an endocrine function, producing 5-hydroxytryptamine, or a closely related substance.

Tetracyclines administered to growing children localize in dentine of forming teeth in sufficient amounts to give them a bright yellow colour. Fluorescence microscopy under ultra-violet light imparts a golden-yellow colour to areas of dentine stained yellow by the antibiotic. Fluorescence is associated with a typical globular pattern of calcification in dentine and cementum. Although disturbance of dentine mineralization is demonstrable in the form of large interglobular areas these are not associated with the tetracycline bands per se but are probably localized manifestations of chronic systemic illness. Enamel does not fluoresce when viewed directly along the ultra-violet beam.

Puring (Codiaeum variegatum (Linn.) Blume) which is native to Ambon has shape and colourful leaves, and people likethem much. This research was aimed to study: (i) the diversity of forma in Codiaeum variegatum, and (ii) number of those forma in Yogyakarta. There are thirteen forma in Yogyakarta, namely: C. verieqstum picturn 'Graigi', C. variegatum Golfinger, C. variegatum pictum, C. variegatum pictum Yoseph's coat, C. variegatum Mortii, C. variegatum Gold, C. variegatum Eggs, C. variegatum Tendril, C. variegatum pictum Princess Mary, C. variegatum pictum Princess, C. variegatum pictum Caudatum, C. variegatum Caudatum, and C. variegatum Sulcal. The two forma special form called kidang emas and lancuran planted in cemetery by Javanese due to its ritual value of yellow colour. The other forma its outdoor garden plants. The leaves of forma have degradation on colours and variation on shapes.© 2003 Jurusan Biologi FMIPA UNS SurakartaKey word: puring (Codiaeum variegatum), keragaman, forma, magis