White Pearls Research Articles

Influence of geographical origin and shell positions on nacre color and thickness in mabé pearl oysters Pteria penguin

To examine variations in nacre color and thickness in Pteria penguin oysters obtained from Tonga and Japan, a novel approach with a focus on their potential for mabé pearl production was used. Detailed analyses of color and microstructure revealed that the middle position of the right-valve nacre (position 1) primarily showed a reduction in yellow pigmentation. This was indicated by a decrease in the yellowness index (YI) and an increase in the whiteness index (WI). In contrast, the anterior and middle positions of the left-valve nacre (positions 2 and 3) consistently displayed a higher level of yellow pigmentation. A comparison of oysters from different geographical origin found that Tonga wild-caught oysters had significantly thicker nacre than Tonga culture-site oysters, suggesting the influence of probable genetic diversity and environmental factors on nacre formation. Notably, nacre at position 1 was generally thinner, while at positions 2 and 3 it was thicker, which would influence the resultant pearl quality and attributes. We demonstrate the significance of the nacre position on the valve for mabé pearl production: position 1 tended to produce white pearls with pronounced interference colors, whereas position 2 tended to yield gold pearls. Furthermore, our findings highlight the significant impact of the oysters' geographic origin on mabé pearl color and quality. This study emphasizes the importance of considering the position of shell nacre and the potential influences of the oysters' genetic origins and environmental factors on mabé pearl formation.

PROSPECTS FOR THE USE OF A NEW NON-TRADITIONAL CULTURE SPRING TRITICAL IN THE PRECISE AGRICULTURE SYSTEM IN THE NORTH-KAZAKHSTAN REGION

The article presents a comparative assessment of the productivity of springtriticale varieties and spring common wheat varieties. It has been shown that springtriticale varieties are significantly more productive than spring soft wheat varieties.It has been established that during the cultivation of spring triticale varieties withgrowth stimulants - White Pearls and Atonik plus, a positive trend is seen inincreasing yields. During the research period, spring triticale varieties showed highresistance to stem and brown rust. In addition to using for feed purposes, springtriticale culture can be successfully used in the field of increasing the nutritionalvalue of products in the bakery, confectionery and animal feed industries.

Influence of meteorological conditions on ripening of grape shoots in south areas of Western Siberia

Introduced grape varieties were studied in the south of Western Siberia in order to identify the effects of unfavourable factors of the growing season on the ripening of grape shoots. Weather conditions in the south of Western Siberia during the vegetation periods 2012-2017 were characterized by large fluctuations in water and temperature conditions; there were sharp changes not only in different years, but also during one season. Compared with long-term average data, a significant increase of relative air humidity and the amount of precipitation was noted from May to September. In 2016-2017 sharp changes of the amount of precipitation by months were marked (dry June, over-moistened July). The most unfavorable weather conditions for grape crop were the conditions of the growing season of 2013 with excessive rainfall (410.3 mm), very low average monthly air temperatures in May, June, July, September and the sum of active temperatures (2031.7°C). Under the influence of meteorological conditions, the terms of the beginning of the studied phenological phase changed very significantly over the years (30-62 days). Shoots ripening in years with favourable weather conditions (2012, 2015) began from July 14-August 1, with unfavorable (2013, 2017) — September 11-15. In one grape variety, insignificant variability of the degree of the studied character was revealed by years, in two — medium, in eight — high. Shoots ripened better in warmer and less humid 2012 (66.8-94.1 %) and in 2015 (58.4-92.5 %). Varieties with very poor ripening (33.0-46.9 %) Arkady, Kodryanka, Tomaysky are unsuitable for cultivation under production conditions and recommended for cultivation in amateur gardens with additional shelter. Varieties with maximum ripening of shoots on average over the years were selected from the American group White Pearls, Latvian Pink (83.1-84.9 %), Amurian Adel, Vaskovsky Souvenir, Hasan Bousa (65.5-79.3 %).

Use of wood in the Baltic courses architecture on the example of Binz in Ruges

Use of wood in the Baltic courses architecture on the example of Binz in Ruges. The town of Binz is a great example of a comprehensive renovation of a town built in a spa style using wood. Made of wood, balconies, loggias, porches, gables, half-timbered constructions of fragments or even entire floors of buildings, combined with various architectural elements, referring to different stylistic formations, creates a perfectly matching conglomerate of forms despite each other's diversity and the surrounding nature. Thanks to the forms of decoration used, the frontage of the building looks harmonious. Laurel ornaments give them a specific beauty that allows you to break away from reality and encourages relaxation. Accents in the landscape, especially variety of villas, prevent fatigue and add expression to the whole building giving desire to just watch them. However, without the use of wood usually painted white, this would never have been achieved. That is why they were often called "white pearls of the Baltic".

“This Heavy Thing”: Catherine the Great’s Coronation Crown

After seizing power in 1762, Catherine II organized the most extravagant coronation money could buy. To add to the splendour, she placed a rush order for a crown. With carte blanche to use luxurious objects from the Russian treasury, jeweler Jérémie Pauzié designed “one of the richest objects that has ever existed in Europe”. Five thousand diamonds adorned the surface of the two half spheres; two rows of white pearls outlined the edges of the miters. The pièce de résistance was a nearly 400-carat ruby red spinel, removed from the crown of Empress Anna, niece of Peter the Great. The world’s second largest spinel had been acquired in Peking in 1676 by Russia’s envoy to China. Thrilled, Catherine declared that she’d somehow manage to hold “this heavy thing” on her head during the four-hour Kremlin ceremony. In the tradition of Byzantine emperors before and Napoleon after, Catherine placed the crown on her own head. It was worn by all of her successors, from her son Paul I to Nicholas II, Russia’s last tsar.

Relationship of the orange tissue morphotype with shell and pearl colouration in the mollusc Pinctada margaritifera

Molluscs display a vast range of shell colours both between and within species. However, only a few species show colour variation in their soft tissues. In French Polynesia, the pearl oyster Pinctada margaritifera has three tissue morphotypes: the black wild-type and two rare mutations: white albino and orange mantle. Phenotypic transmission is known to occur from these phenotypes when they are used as graft donors for pearl production, leading to multicoloured and white pearls from black and albino mantle grafts, respectively. The present study furthers this knowledge by examining the phenotypic association between the orange mantle tissue morphotype and hard tissues: shells and cultured pearls. Based on a large experimental graft, shell colour quantification and pearl qualification showed that the orange morphotype is associated with light-coloured shells and pearls. Expression analysis of some candidate genes previously identified in the white mantle mutant, tested here on both graft and pearl sac tissues from orange mantle donors, confirmed the involvement of genes associated with shell matrix protein (shem4) and the melanin biosynthesis pathway (zinc). This study provides fundamental information on the mechanism behind mantle tissue colour in P. margaritifera and its association with biomineralisation and pigmentation processes that will be potentially valuable in future selection programs.

A COLOR THAT COMMUNICATES WITHOUT A WORD – “WHITE”

The meaning of color white is purity, innocence, wholeness and completeness. It is the color produced by the combination of all the colors of visible spectrum.The color white belongs to ancient history. During the Paleolithic age, the artists used calcite and in chalk in their paintings. Egyptians connected it with their goddess Isis,who only dressed in white linen and hence used to wrap mummies.White was often associated with mother’s milk, in Greek mythology .White is the color of the human eye sees when it senses light which contains all the wave lengths of the visible spectrum. Mostly white animals have their color as a form of camouflage in winter such as dove,ivory gull,swans,arctic fox, white pearls produced by mollusk and when talking of its horrifying side it symbolizes ghosts and phantoms in many cultures/civilization. In India, white is worn on various rituals and often associated with sadness especially when somebody dies. Unlike other things, white also plays an important role in our diet.White is associated with the top of the color spectrumand, inAsian medicine, with strengthening to the lungs and large intestines .White fruits and vegetables contain nutrients such as beta-glucans, EGCG, SDG, and lignans that provide powerful immune boosting activity. These nutrients also activate natural killer B and T cells, reduce the risk of colon, breast, and prostate cancers, and balance hormone levels, reducing the risk of hormone-related cancers.White foods are often rich in sulfur and Quercetin. May reduce the risk of cancer and help the body get rid of cancer causing chemicals.e.g. buckwheat, cauliflower ,coconut, garlic, green onion, millet,mushrooms, sunflower seeds, tofu, white beans, corn, white eggplant, white radishes.

In situ study of stones adorning a silver Torah shield using portable Raman spectrometers

A silver Torah shield fitted with a set of precious stones and glass imitations crafted in Poland in the first half of the 19th century was investigated using two of the currently distributed portable and relatively low‐cost Raman spectrometers in situ at the Jewish Museum in Prague. Observed Raman peaks corresponded well (+/− 3 cm−1) to the reference values. The hand‐held instruments operated at 785‐ and 532‐nm laser excitations showed good performance in the fast and unambiguous identification of nearly 60 stones which were fitted on the shield: one blue aquamarine, three purple amethysts, thirteen red garnets (all classified as high‐percentage almandines), three white pearls, fifteen pieces of red coral and five chalcedonies (one white and four red). All of the other stones were identified as colored glass. The rather chaotic mixture of stones of various colors, cuts and sizes and the total volume of imitation glass support the theory that the mounted stones were gathered from Jewish households and donated for the adornment of the shield. The common portable Raman instruments represent an ideal tool for the quick and accurate identification of gemstones mounted in historical artifacts in situ in the framework of museum or collection sites in a non‐destructive way. Copyright © 2014 John Wiley & Sons, Ltd.

Assessing Pearl Quality Using Reflectance UV-Vis Spectroscopy: Does the Same Donor Produce Consistent Pearl Quality?

Two groups of commercial quality (“acceptable”) pearls produced using two donors, and a group of “acceptable” pearls from other donors were analyzed using reflectance UV-Vis spectrophotometry. Three pearls with different colors produced by the same donor showed different absorption spectra. Cream and gold colored pearls showed a wide absorption from 320 to about 460 nm, while there was just slight reflectance around 400 nm by the white pearl with a pink overtone. Cream and gold pearls reached a reflectance peak at 560 to 590 nm, while the white pearl with pink overtone showed slightly wider absorption in this region. Both cream and gold pearls showed an absorption peak after the reflectance peak, at about 700 nm for the cream pearl and 750 nm for the gold pearl. Two other pearls produced by the same donor (white with cream overtone and cream with various overtones) showed similar spectra, which differed in their intensity. One of these pearls had very high lustre and its spectrum showed a much higher percentage reflectance than the second pearl with inferior lustre. This result may indicate that reflectance is a useful quantitative indicator of pearl lustre. The spectra of two white pearls resulting from different donors with the same color nacre (silver) showed a reflectance at 260 nm, followed by absorption at 280 nm and another reflectance peak at 340 nm. After this peak the spectra for these pearls remained flat until a slight absorption peak around 700 nm. Throughout the visible region, all white pearls used in this study showed similar reflectance spectra although there were differences in reflectance intensity. Unlike the spectral results from white pearls, the results from yellow and gold pearls varied according to color saturation of the pearl. The results of this study show that similarities between absorption and reflectance spectra of cultured pearls resulting from the same saibo donor are negligible and could not be detected with UV-Vis spectrophotometry. Nevertheless, this technique could have a role to play in developing less subjective methods of assessing pearl quality and in further studies of the relationships between pearl quality and that of the donor and recipient oysters.

Chord theorems on graphs

The Horizontal Chord Theorem states that if a continuous curve connects points A and B in the plane, then for any integer k there are points C and D on the curve such that − − → AB = k − − → CD. In this note, we discuss a few combinatorial-analysis problems related to this theorem and introduce a different formulation that gives way to generalizations on graphs. 1 THE NECKLACE OF PEARLS PROBLEM. Two pirates have a single-strand necklace containing 2N black pearls and 2N white pearls arranged in any order. They would like to cut the necklace into as few pieces as possible so that after dividing the pieces of the necklace between them, each gets exactly N white pearls and N black ones. Using the following theorem, one can show that two cuts are sufficient. V. Totik has discussed several problems, including the above mentioned and the combinatorial-analysis theorem below, in the Monthly paper ‘A Tale of Two Integrals’ [4].

Determination by Raman scattering of the nature of pigments in cultured freshwater pearls from the mollusk Hyriopsis cumingi

AbstractThe nature of pigments in naturally colored pearls is still under discussion. For this study, Raman scattering measurements were obtained for 30 untreated freshwater cultured pearls from the mollusk Hyriopsis cumingi covering their typical range of colors. The originality of this work is that seven different excitation wavelengths (1064 nm, 676.44 nm, 647.14 nm, 514.53 nm, 487.98 nm, 457.94 nm, 363.80 nm) are used for the same samples at the highest possible resolution. All colored pearls show the two major Raman features of polyenic compounds assigned to double carbon–carbon (CC) – at about 1500 cm−1 – and single carbon–carbon (CC) – at about 1130 cm−1 – bond stretching mode, regardless of their specific hue. These peaks are not detected in the corresponding white pearls, and therefore seem directly related to the major cause of body color. Additionally, the exact position of CC stretching vibration shows that these compounds are not members of the carotenoid family. Moreover, some changes are observed in intensities, shape and positions of the two main characteristic polyenic peaks from one sample to the next. Similar changes are observed also using several excitation wavelengths for the same point of the same pearl. The exact position of CC stretching vibration of polyenic molecules depends strongly on the number of double bonds (N) contained in their polyenic chain. Hence, using a constrained decomposition of this band for different excitation wavelengths, up to nine different pigments may be detected in the same pearl. Their general chemical formula is R‐(CHCH)N‐R′ with N = 6–14. All our colored samples contained at least four pigments (N = 8–11). Different colors are explained by different mixtures, not by a simple change of pigment. The chemical nature of the chain ends is still unknown, because it cannot be detected with Raman scattering. However, it is possible that these polyenes are complexed with carbonate molecules of the nacre. Similar coloration mechanisms are found in products from other living organisms (e.g. parrots feathers). Moreover, it seems that a similar series of pigments is found in other pearls also, as well as in some marine animals living in similar environments (e.g. corals). Copyright © 2006 John Wiley & Sons, Ltd.

Multiple Personalities and Pastiches: Proust pere et fils

IT HAS BEEN SOME TIME SINCE PSYCHIATRY, followed by mass media, rediscovered a syndrome that kept specialists in various disciplines, including philosophy, in suspense even at turn of century: multiple personality disorder. The genealogy and archaeology of this oddly illness seem not yet sufficiently linked to cultural and literary history, despite contributions of scientific theorist Ian Hacking in describing appearance, reappearance, and disappearance of double and multiple personalities, and their metamorphoses. My own contribution goes beyond Hacking, in that it calls for an integration of history of science and of literary history that I would characterize as a discursive-analytical integration. In any case, following concerns neither theoretical nor historical configurations that might give us an overview of problem. Rather, I limit myself to a few specific case-studies that I hope will make desideratum of an interdiscursivelyoriented literary history plausible. In Goncourt pastiche that Marcel Proust incorporates in last volume of A la recherche du temps perdu, we are confronted with a curious detail: black pearl necklace that Madame Verdurin wears was originally white. The art-lover Swann, who attests to change in color, has even seen the portrait of these pearls around Madame de La Fayette's neck, later sold at auction by her descendants. The white pearls were blackened during a conflagration in part of Verdurin house. This oddity leads to Dr. (and Professor) Cottard's informative and entertaining contribution to conversation. I would like to quote extensively from this contributionalways from perspective of Proust's fabrication of unpublished Goncourt diaries. I owe pleasure of being able to introduce theme of split (double and multiple) personalities in complex Proust-Goncourt authorial figure and in fictional Dr. Cottard to insights that Henri F. Ellenberger offers in his admirable book, The Discovery of Unconscious.1