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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
71

How to get changing patterns on a textile surface by using thermo chromic pigments and an inherently conductive polymer

Maleki, Laleh January 2013 (has links)
With regard to the recent interests in smart textiles,this research activity has been conducted with the aim of producing a pattern changing design on textiles. In order to fulfill the demands of such dynamic patterns a combinationof conductive polymer and thermochromic pigments wereused. The textile substrate was coated by conductive polymer dispersion(PEDOT:PSS) and it was followed with printing thermochromic pigments on the surface of coating.The driving force of such thermochromic reaction has to be provided by the heat generated from conductive layer dueto the current of electricity passing through the conductivelayer. These experiments were continued by changing thecoating recipe in order to achieve the highest possible electrical resistance,which leads to the best initiation ofthermochromic reactions. / Program: Master programme in Textile Technology
72

Estudo morfológico da retina e genético do pigmento visual LWS de cinco espécies de corujas e sua relação com o ritmo circadiano / Not informed by the author

Vasconcelos, Felipe Tadeu Galante Rocha de 21 November 2017 (has links)
As corujas formam um grupo diversificado, estando presentes em diversos habitats ao redor do globo e têm diferentes padrões de atividade, com espécies diurnas, noturnas e crepusculares. Os fotorreceptores encontrados em corujas são os bastonetes e três classes de cones, levando potencialmente à tricromacia, e as demais camadas da retina mantém a mesma organização de outras aves. O gene LWS tem sido estudado em aves e o pico de absorção espectral da opsina expressa por esse gene está entre 560-570nm. Exceções foram reportadas no melro-preto (P557), pinguim Humboldt (P543) e na corujado- mato (Strix aluco). Entre esses três gêneros, somente as corujas apresentam espécies com diferentes hábitos circadianos. Dessa forma é possível que diferentes adaptações visuais possam ser encontradas em associação com o padrão circadiano. Neste trabalho foi investigada a morfologia da retina e a genética do pigmento visual LWS de cinco espécies de corujas com diferentes ritmos circadianos: Asio clamator, Megascops choliba, Tyto alba (noturnas), Athene cunicularia e Glaucudium brasilianum (diurnas). Um indivíduo de cada espécie foi utilizado nos experimentos. Foi realizada a extração de RNA a partir de uma retina homogeneizada de cada espécie e o RNA mensageiro (mRNA) foi convertido em DNA complementar (cDNA). Partes do gene LWS foram amplificadas utilizado a reação em cadeia da polimerase (PCR) e sequenciadas utilizando a metodologia de Sanger. Cinco sítios importantes para o ajuste espectral da opsina LWS (164,181, 261, 269 e 292) foram analisados e comparados com a sequência de outras aves e da rodopsina bovina, a qual foi referência para determinar as posições dos aminoácidos. No estudo morfológico, foram realizados cortes transversais em criostato de uma retina de cada espécie de coruja. Para a reação de imunohistoquímica foi utilizado o anticorpo Rabbit anti opsin (AB5405) para marcar cones L/M e DAPI marcando núcleos celulares. Também foi realizada a coloração de Hematoxilina-Eosina (HE) para visualizar a organização da retina. A partir das análises morfológicas foi possível observar a presença de cones nas retinas das cinco espécies de corujas, bem como uma organização laminar semelhante a de outros vertebrados. Para todas as espécies estudadas, os resultados da análise de sequência da opsina LWS foram: A164, H181, Y261, T269 e A292. Ao menos para o gene LWS, não foram encontradas diferenças entre espécies diurnas e noturnas de corujas / The owls forms a diverse group present in many habitats around the world and they have different activity patterns, with diurnal, nocturnal and crepuscular species. Photoreceptors found in owls are the rods and three classes of cones that potentially provide trichromacy, and the other retinal layers maintain the same organization of other birds. The LWS gene has been studied in birds and the peak spectral absorption of opsin expressed by this gene is between 560- 570nm. Exceptions were reported on blackbird (P557), Humboldt penguin (P543) and tawny owl (Strix aluco). Among these three genera, only owls have species with different circadian habits. It is therefore possible that different visual adaptations can be found in association with the circadian pattern. In this study the retinal morphology and the genetics of LWS visual pigment of five owl species with different circadinan habits were investigated: Asio clamator, Megascops choliba, Tyto alba (nocturnal), Athene cunicularia e Glaucudium brasilianum (diurnal). One individual of each species was used in the experiments. RNA extraction was performed from a homogenized retina of each species and messenger RNA (mRNA) was converted into complementary DNA (cDNA). Parts of the LWS gene were amplified using the polymerase chain reaction (PCR) and sequenced using the methodology of Sanger. Five important sites for the spectral tuning of the LWS opsin (164, 181, 261, 269 and 292) were analyzed and compared to the sequence of other birds and bovine rhodopsin, which was referenced to determine amino acid positions. In the morphological study, cross - sections were performed in cryostat of a retina of each owl species. For the immunohistochemistry reaction, the rabbit anti-opsin antibody (AB5405) was used to label L / M cones and DAPI labeling cell nuclei. Hematoxylin-Eosin (HE) staining was also performed to visualize the organization of the retina. From the morphological analyzes it was possible to observe the presence of cones in the retinas of the five species of owls, as well as a laminar organization similar to that of other vertebrates. For all species studied, the results of LWS opsin sequence analysis were: A164, H181, Y261, T269 and A292. At least for the LWS gene, no differences were found between diurnal and nocturnal species of owls
73

Noble souls

Heineman, Margaret Mae 01 May 2015 (has links)
Sunset Iridescence is a one of a kind sculptural bookwork which reflects the essence of the wings of the Madagascar Sunset Moth. My work is very much about the physical qualities of the materials I use. The papers, inks and gilding supplies used to recreate the colors and iridescence of the moth are described. A comparison of color created by pigment and color created by the refraction of light rays is discussed. Parallels are drawn between the structure of the codex and the behavioral patterns of the moths. The local name for the Madagascar Sunset Moth is Lolonandriana - lolo for `spirit or soul,' andriana for `noble.' I was inspired by this concept of the soul to publish a letterpress printed chapbook. Unlike Flying in an Airplane is a short memoir of one of my experiences as a flight nurse. It recalls the first moments of lifting off in a helicopter as I prepared to stabilize and transport a critically ill child.
74

Isolation, characterisation and properties of 8,8-methylmethine flavan-3-ol-malvidin-3-glucoside pigments found in red wines.

Lee, David, F. January 2008 (has links)
This study concerns the isolation, characterisation and physio-chemical properties of 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside compounds found in red wines. 8,8-Methylmethine-(epi)catechin-malvidin-3-glucoside compounds were isolated via chromatographic methods developed in this study. The compounds were characterised via nuclear magnetic resonance spectrometry which, with the aid of molecular modelling, afforded their possible 3-dimensional structures. Their physio-chemical properties including ionisation and hydration constants, colour parameters and chemical stabilities were determined. The formation of 8,8-methylmethine-flavan-3-ol-malvidin-3-glucoside compounds and other pigments in wines was also studied. 8,8-Methylmethine-(epi)catechin-malvidin-3-glucoside compounds were also synthesised by condensing malvidin-3-glucoside with (epi)catechin in the presence of acetaldehyde. Diastereomers of 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside pigments were isolated from the reaction using size-exclusion liquid chromatography followed by cation-exchange liquid chromatography. The structures of the four 8,8-methylmethine-catechin (and epicatechin)-malvidin-3-glucoside diastereomers were determined using mass spectrometry and one and two-dimensional nuclear magnetic resonance spectroscopy. It was found that for all four compounds, the methylmethine bridge occurs at the 8-positions of malvidin-3-glucoside and (epi)catechin and that the 3-dimensional structural differences between the diastereomers is the positioning of the (epi)catechin moiety with respect to the glucoside group. One diastereomer has the (epi)catechin on the same side, with respect to the malvidin entity whilst it is on the opposite side for the other diastereomer. The proposed structures also afforded the malvidin entity protection from nucleophilic attack via steric hindrance by the (epi)catechin moiety. 8,8-Methylmethine-(epi)catechin-malvidin-3-glucoside pigments have greater colour stability with regards to changes in pH and SO2 bleaching compared to malvidin-3-glucoside providing evidence that little or no hydration in aqueous solutions is occurring for these compounds. Further evidence for little or no hydration occurring is the presence of isosbestic points in the UV-vis spectra observed for the 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside in the pH range 2 to 7. Although the 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside pigments have greater colour stability to pH, SO2 and oxidation, compared to malvidin-3-glucoside, they have lower temporal stabilities and under both aerobic and anaerobic conditions they have significantly higher degradation rate constants than malvidin-3-glucoside. The ionisation constants of the 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside compounds were determined using high voltage paper electrophoresis (HVPE) and UV-visible spectroscopy. The first ionisation constants (pKa1) of the 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside compounds were found to be higher than that of malvidin-3-glucoside whereas the second and third ionisation constants (pKa2 and pKa3) were found to be lower. The correlation of the ionisation constants between HVPE and UV-visible spectroscopy supports the proposal that there is little or no occurrence of hydration for the 8,8-methylmethine-(epi)catechin-malvidin-3-glucoside compounds in the pH range investigated. 8,8-Methylmethine-flavan-3-ol-malvidin-3-glucoside compounds were the major pigments formed during fermentations of chemically defined grape juice media containing malvidin-3-glucoside and various flavan-3-ols. The yeast strain used for fermentation had a major influence on the levels and rates of formation of these pigments during fermentation. The yeast strain used also has an important influence on wine pigment composition, concentration and evolution during maturation thereby affecting the colour density and hue of the resultant wines. The initial formation of 8,8-methylmethine-flavan-3-ol-malvidin-3-glucoside compounds and their subsequent gradual degradation during maturation, allowed a pool of malvidin-3-glucoside to be available for the formation of other colour stable and more temporally stable pigments. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1339479 / Thesis (Ph.D.) - University of Adelaide, School of Agriculture, Food and Wine, 2008
75

Purification and Characterization of Blue and Green Chromoprotein Pigments from the Integument of Male Darters in the Genus Etheostoma

Boone, Katelyn 05 January 2012 (has links)
Unlike most other vertebrates, many species in the genus Etheostoma do not utilize structural refraction to display blue or green color. Instead, blue and green mating coloration exhibited by male rainbow darters (E. caeruleum) and male greenside darters (E. blennioides) results from the presence of true chromoprotein pigments. This study was conducted in order to extract, purify, characterize, and compare these novel pigments. Pigments were extracted in aqueous buffer and partially purified by ammonium sulfate fractionation and gel filtration chromatography. Final purification consisted of preparative non-denaturing polyacrylamide gel electrophoresis for E. caeruleum and hydroxyapatite chromatography for E. blennioides. Isolation of the chromophore was accomplished using acetone precipitation. The chromophore is the same in both species and is believed to be biliverdin. The protein component differs between the species and appears to have a greater number of subunits in E. blennioides. Binding of the protein to the chromophore amplifies the absorbance in the visible region and causes spectral tuning of the absorbance profile of the chromophore, with slight differences between species. In E. caeruleum, the chromoprotein pigment has a lambda max of 683 nm and transmits light at slightly shorter wavelengths, causing it to appear blue. In E. blennioides, the chromoprotein pigment has a lambda max of 696 nm and transmits light at slightly longer wavelengths, causing it to appear green. This work has shown that the protein component, not the chromophore, is responsible for the difference in hue between these two pigments. Future work will involve obtaining amino acid sequences for the protein component of the pigments and ultimately sequencing the gene coding for these proteins in darters. / Bayer School of Natural and Environmental Sciences; / Environmental Science and Management (ESM) / MS; / Thesis;
76

Association mapping of endosperm colour in durum wheat (<i>triticum turgidum</i> L. var. <i>durum</i>)

Reimer, Sherisse Opal 07 January 2009
Association mapping (AM), based on linkage disequilibrium, is a complementary strategy to traditional quantitative trait loci (QTL) mapping for describing associations between genotypes and phenotypes in crop plants. Yellow endosperm colour, an important quality trait in durum wheat (<i>Triticum turgidum L. var. durum</i>), was studied to determine the potential of AM to (1) identify previously reported QTL using a genome wide scan and (2) to determine allelic association of the phytoene synthase 1 (Psy1) gene using a candidate gene analysis. At present, a number of QTL for endosperm colour have been identified, and phytoene synthase, the initial enzyme of the carotenoid biosynthetic pathway, has been associated with QTL on the group 7 chromosomes which are considered to play a significant role in expression of yellow pigment concentration. CIE 1976 b*, a light reflectance measurement, and water-saturated butanol extracted pigments were assessed on a collection of 93 elite accessions from a variety of geographic origins, and genotyped with 245 markers. Population structure was assessed using genetic distance and Bayesian model based approaches, identifying five sub-populations consistent with breeding origin and pedigree. Association analysis identified significant associations with yellow endosperm colour on all chromosomes, including several previously identified QTL as well as new regions for genomic dissection. Pairwise LD mapping of Psy1-B1 and Psy1-A1 located the genes to chromosomes 7B and 7A respectively, to regions which have previously been identified for yellow pigment concentration QTL. The results of this study indicate that AM can be used to complement traditional QTL mapping techniques, and identify novel QTL for further study.
77

Carotenoid accumulation during grain development in durum wheat (<i>Triticum turgidum</i> L. var. <i>durum</i>)

Ramachandran, Adithya 24 March 2010
Yellow pigment (YP) concentration is an important quality trait in durum wheat (<i>Triticum turgidum</i> L. var <i>durum</i>) and is comprised primarily of carotenoids. The main objective of our study was to measure the accumulation of carotenoids during the grain fill period to improve our understanding of the physiological basis for differences among durum wheat cultivars. Thirteen cultivars and breeding genotypes with large variation in total YP concentration (<6 µg g-1 to >15 µg g-1) were studied. Spikes were sampled from replicated field plots in 2007 and 2008 near Saskatoon and Swift Current, Saskatchewan, Canada, at 14, 21, 28 and 35 days after heading (DAH). The remainder of each plot was combined at grain maturity for YP and carotenoid analysis. Carotenoids were extracted with 1:1 methanol:dichloromethane (0.1% BHT) and quantified with HPLC. <i>Trans</i> (E)-lutein was the predominant carotenoid at maturity and was detected at 14 DAH in all genotypes. The rate and duration of E-lutein accumulation was variable among genotypes expressing high, intermediate and low YP. The accumulation of all carotenoids was lowest in genotypes expressing low YP, and suggests rate limitations early in the carotenoid biosynthetic pathway. E-zeaxanthin concentrations were highest in mature grain, but no significant differences were detected among genotypes. However, the ratio of E-zeaxanthin to E-lutein was inversely correlated with total YP, suggesting that the â,å branch of lycopene cyclization is favoured over the â,â branch in high-YP genotypes. These results provide insights to the regulation of the carotenoid biosynthetic pathway during grain fill stage in durum wheat and will facilitate breeding for higher carotenoid concentration.
78

Differential changes in gene expression in cultured human retinal pigment epithelial cells after beta-amyloid stimulation

Kurji, Khaliq 05 1900 (has links)
Age related macular degeneration (AMD) is the most common cause of irreversible vision loss in the elderly. At present, there are an estimated one million people in Canada with some form of AMD and this number is expected to double to two million by 2031. These estimates are sobering, and it is predicted that costs for treatment and care of individuals who suffer vision loss from AMD will have significant impact on the social and public health systems in Canada in the next two decades. There are treatments to slow the progression of vision loss, but unfortunately, there are currently no cures available for AMD. In order to develop effective second generation therapies and cures, further insights into how and why AMD develops are greatly needed. Recent studies have provided novel insights into the role of inflammation in the pathogenesis of AMD. Inflammation, or swelling of the retinal tissues, causes harmful processes that promote macular degeneration. The proposed studies will focus on the triggers of inflammation in the retina. It is hypothesized that macular degeneration may be slowed or stopped by eliminating the molecules that cause inflammation in the retina. This study will focus on amyloid beta (Aβ), a toxic molecule that has been implicated in retinal inflammation, and the role that it may play in gene expression of the retinal pigment epithelial cell. Amyloid beta is a well studied peptide in another age related disorder, Alzheimer’s disease. It is the major extracellular deposit in Alzheimer’s disease plaques, and has recently been discovered as a component of drusen, the hallmark extracellular deposits in the retina of patients with the ‘dry’ form of AMD. These studies will allow the development of new treatment regimens that target retinal inflammation and thus minimize the processes that ‘trigger’ the onset of macular degeneration.
79

Sambandet mellan bestrykningsrecepturoch sänkningen av ytansvithet vid UV-lackning

Sjöström, Henrik January 2005 (has links)
AssiDomän tillverkar kartong till förpackningsindustrin. Inom detta område är vitheten på kartongytanen viktig parameter. För att höja intrycket av förpackningen samt skapa en skyddande yta lackas ofta förpackningen med UV-lack efter tryck. Efter lackning kan då otryckta lackade ytor uppfattas som mindre vita. För att ta reda på om bestrykningssammansättningen har betydelse har ett fem olika bestrykningar blandats. Pigmenten som använts i bestrykningarna är karbonat, kaolin och titandioxidi olika kombinationer. Kartong har sedan bestrukits med dessa och därefter lackerats med UV-lack. Lackningen har gjorts i tre olika lackmängder. Mätningar har sedan gjorts gällande framförallt vithet. Den samverkan som sker mellan ljus, materialet och dess struktur är av stor vikt för att skapa en yta med goda optiska egenskaper. Resultaten i detta försök visar att lacken påverkar de optiska egenskaperna och framförallt vitheten. De lackerade ytorna fick en gulton efter lackering vilket kan ha att göra med lackens egenskaper. Vitheten hade en något mindre minskning för den bestrykning som bestod av karbonat och titandioxid. Skillnaden var dock mycket liten då alla bestrykningar fick en sänkning av vitheten med cirka 11-13 procentenheter oberoende av utgångsvärdet i vithet för respektive bestrykning innan lackning. Positivt var att det kunde konstateras att den bestrykning som hade det högsta vithetsvärdet före lackning också hade det efter lackning med ett normalt lackpålägg vilket betyder att en hög vithet är av betydelse även om den bestrukna ytan ska lackas. Den sänkning av vitheten som sker kan ha flera tänkbara orsaker. En tänkbar orsak kan vara att lacken förstör den porösa struktur som ger den viktiga ljusspridningen i bestrykningsskiktet. Resultaten visar också att lackens egenskaper tycks vara av stor betydelse. Den gulton som framträdde efter lackning tyder på en ökad absorption av vissa ljusvåglängder. Något som också pekar på detta är att alla fem bestrykningarna fick en liknande sänkning av vitheten. För att säga exakt vad som är orsaken eller vilken kombination som påverkar vitheten mest krävs ytterliggare tester. Olika UV-lacker kan testas eftersom endast en UV-lack har använts i dessa försök. En närmare studie av gränsyta mellan UV-lacken och bestrykningsskiktet bör också göras för att se hur lacken påverkar bestrykningsskiktets struktur.
80

Association mapping of endosperm colour in durum wheat (<i>triticum turgidum</i> L. var. <i>durum</i>)

Reimer, Sherisse Opal 07 January 2009 (has links)
Association mapping (AM), based on linkage disequilibrium, is a complementary strategy to traditional quantitative trait loci (QTL) mapping for describing associations between genotypes and phenotypes in crop plants. Yellow endosperm colour, an important quality trait in durum wheat (<i>Triticum turgidum L. var. durum</i>), was studied to determine the potential of AM to (1) identify previously reported QTL using a genome wide scan and (2) to determine allelic association of the phytoene synthase 1 (Psy1) gene using a candidate gene analysis. At present, a number of QTL for endosperm colour have been identified, and phytoene synthase, the initial enzyme of the carotenoid biosynthetic pathway, has been associated with QTL on the group 7 chromosomes which are considered to play a significant role in expression of yellow pigment concentration. CIE 1976 b*, a light reflectance measurement, and water-saturated butanol extracted pigments were assessed on a collection of 93 elite accessions from a variety of geographic origins, and genotyped with 245 markers. Population structure was assessed using genetic distance and Bayesian model based approaches, identifying five sub-populations consistent with breeding origin and pedigree. Association analysis identified significant associations with yellow endosperm colour on all chromosomes, including several previously identified QTL as well as new regions for genomic dissection. Pairwise LD mapping of Psy1-B1 and Psy1-A1 located the genes to chromosomes 7B and 7A respectively, to regions which have previously been identified for yellow pigment concentration QTL. The results of this study indicate that AM can be used to complement traditional QTL mapping techniques, and identify novel QTL for further study.

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