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Hannach, Gabriela. "Phenotypic plasticity in the red alga Porphyra abbottae : environmental factors influencing light harvesting ability /." Thesis, Connect to this title online; UW restricted, 1990. http://hdl.handle.net/1773/5210.
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Curtis, Bruce Anthony. "A morphological and phylogenetic investigation of Porphyra linearis Greville and Porphyra purpurea (Roth) C. Agardh forms from Nova Scotia." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp04/mq23688.pdf.
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Griffin, Neil John. "Harvest ecology and biodiversity of South African Porphyra." Doctoral thesis, University of Cape Town, 2003. http://hdl.handle.net/11427/10564.
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Bibliography: 140-161 leaves .Porphyra (Bangiales, Rhodophyta) is the world's most valuable maricultured seaweed, due to its high value as a food crop. The vast majority of Porphyra in South Africa belongs to P. capensis, a morphologically and ecologically plastic taxon apparently endemic to the region. There is no demand for P. capensis as a food crop, as it is unsuitable for the market, and there are no records of its customary use locally. Porphyra capensis is however a potentially highly valuable fodder for the mariculture of abalone (Haliotis midae), and pressure to harvest it has recently increased. This study aims to assess the potential for harvest of Porphyra on the south-western shores of South Africa. There are two main thrusts to this work. The fIrst thrust examines Porphyra as an ecological entity in the region. The second thrust reassesses the taxonomy of Porphyra species in the region.
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Schweikert, Katja, and n/a. "The functional biology of Porphyra sp. in New Zealand." University of Otago. Department of Botany, 2007. http://adt.otago.ac.nz./public/adt-NZDU20080910.114121.
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The intertidal red algal genus Porphyra is found on rocky shores worldwide. In the Northern Hemisphere the genus is well studied but there is a paucity of data on southern hemisphere Porphyra and even less on New Zealand Porphyra. The species� taxonomy has been undergoing revision since the late 1990�s, when it was discovered that the main species P. columbina and P. lilliputana reported for New Zealand were a combination of several endemic species. These species are found from the low to the high intertidal watermark; hence they are exposed to fluctuating stresses such as desiccation, temperature, high light and UV radiation. Algae have evolved a number of mechanisms to adapt to naturally changing increasing abiotic conditions, such as accumulation of screening pigments and changes in antioxidant metabolism during light stress. For terrestrial plants, polyamines (small aliphatic amines) have been shown to be involved in protecting cells from damage under conditions of stress including UV-B radiation; such mechanisms have yet to be identified in algae.
The overall aim of this study was to determine the importance of cellular processes in shaping the community structure of Porphyra on a wave-exposed shore on the east coast of the South Island, New Zealand. Porphyra distribution and community structure was assessed by regular monthly monitoring of presence and absence of Porphyra along four transect lines at the site. Enviromnental information was recorded to determine the effects of temperature, light, UV radiation, humidity and wind on Porphyra�s spatial and temporal distribution. Regular tissue samples were taken for species identification by the application of primers, which were specifically designed during this study. P. cinnamomea and Porphyra spec. "ROS 54" were identified as dominant species present almost throughout the year with a pronounced maximum in presence during late winter and spring, and some weeks of absence during April or May. The two dominant species were recorded from the low to the high intertidal shore, but the mid intertidal was identified as the preferred habitat. Other species that were found were rare and only present for a few months in a very restricted area. It was hypothesised that free radical generation and antioxidant metabolism are associated with desiccation tolerance in Porphyra. An attempt was made to investigate the impact of desiccation stress on Porphyra. The extraction process of antioxidants was problematic and no reproducible results could be obtained. It was attempted to investigate the spatial distribution of spores and conchocelis of different Porphyra species in the field, and determine if those found at Brighton Beach are species-specific in their morphology. This indicated that the two main Porphyra species at Brighton Beach not only prefer to occupy the same habitat but that they also have a morphologically similar conchocelis phase.
Mechanisms on a cellular level such as polyamine metabolism affected by environmental (abiotic) stresses are related to the alga�s ability to adapt to stress and therefore can have an effect on Porphyra�s distribution along the shore and its presence throughout the year. The depletion of the ozone layer has become an important issue as the effects of increased UV radiation on the environment, especially the intertidal habitat, are revealed. Marine macrophytes possess the main three. polyamines: putrescine, spermidine and spermine of varying levels. For the few species studied, Rhodophyta generally contain higher levels of polyamines than Chlorophyta, while polyamine levels for the one heterokontophyte analysed were between Chlorophyta and Rhodophyta. Levels of the three most common polyamines (putrescine, spermidine, spermine) were determined in P. cinnamomea under controlled UV exposure. Tissue discs were exposed to visible light (PAR), PAR and UV-A or PAR, UV-A and UV-B radiation. Discs exposed to PAR and PAR and UV-A showed little change in polyamine levels over a six day trial period, while discs exposed to PAR, UV-A and UV-B showed a significant increase in free, bound soluble and bound insoluble polyamines over the same period of time. Correspondingly levels of ADC and ODC, two enzymes involved in polyamine synthesis, were measured. ODC levels changed little while ADC levels increased significantly during UV-B treatment, indicating that under UV-B stress polyamines are mainly synthesized via the ADC pathway. The experimental set-up and process of this study has not been applied in macroalgal polyamine research and results obtained are the first indication that increased levels of polyamines are involved in protection and/or protection mechanisms in macrophytic algae to prevent UV-B damage.
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Tala, Fadia. "Fenologia e ecofisiologia das macroalgas Porphyra spp. (Bangiales, Rhodophyta) e Lessonia spp. (Laminariales, Phaeophyceae) na costa norte e central do Chile: variações latitudinais e sazonais." Universidade de São Paulo, 2013. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-31032014-110235/.
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O propósito dos estudos fenológicos é descrever e compreender como o desenvolvimento dos organismos ocorre em resposta às variações ambientais que mudam ciclicamente e como certos fatores estimulam a geração de uma cascata de sinais e reações que abrangem desde mudanças moleculares, bioquímicas e fisiológicas, os que acabam se manifestando como padrões anuais de abundância e reprodução. As mudanças ambientais ocorrem em escalas temporais (diárias, sazonais, interanuais) e espaciais (latitudinal, em profundidade, em altitude) e têm um forte impacto no crescimento e desenvolvimento das espécies, em especial de aquelas com características sésseis. O objetivo deste estudo foi caracterizar os padrões fenológicos (sazonais e latitudinais) de abundância, reprodução, fotossíntese e capacidade antioxidante de dois gêneros de macroalgas de importância ecológica e econômica, Porphyra spp. (rodofícea) e Lessonia spp. (feofícea), distribuídas ao longo da costa norte e centro (25° - 34°S) do Chile. Os resultados mostram que variações sazonais de radiação e latitudinais de temperatura influenciam significativamente as respostas fenológicas e ecofisiológicas das espécies estudadas. No caso de Porphyra spp., o ajuste temporal mais notório envolve um desenvolvimento fenológico anual para a população do norte e perene para as do centro e sul. As características fisiológicas mostraram diminuição na eficiência fotossintetizante, pigmentos (clorofila α, carotenoides e ficobiliproteínas) e proteínas solúveis em primavera-verão, acompanhados por aumento da capacidade antioxidante. No caso de Lessonia e embora a abundância não tenha mostrado uma mudança sazonal nas populações, o ajuste temporal mais notório aconteceu nas características fisiológicas, com diminuição na eficiência fotossintetizante, pigmentos (clorofilas α e c, carotenoides), fenois e capacidade antioxidante durante o verão, acompanhado por aumento na absorptância do talo, ETRmax e NPQ. Estudos sobre as identidades taxonômicas das populações de Porphyra são necessários para distinguir entre possíveis padrões devido à caraterísticas da espécie de possíveis variações morfológicas ou ecotípicas. Estudos das espécies de Lessonia próximas aos seus limites de distribuição biogeográfica poderiam elucidar se as diferenças fenológicas e fisiológicas são devido a padrões dependentes das espécies ou são mascaradas por características ambientais locais. Os estudos fenológicos e as mudanças em nível bioquímico/fisiológico podem subsidiar novos destinos da biomassa produzida ou da matéria prima proveniente de organismos de importância econômica. Além disso, alterações nos padrões fenológicos e ecofisiológicos típicos podem direcionar a compreensão sobre os impactos de câmbios ambientais tais como os câmbios climáticos globais, contaminação e poluição, sobrexploração e as interações e dinâmica entre as populaçõesThe purpose of phenological studies is to describe and understand how the development of the organisms occurs in response to environmental variations which change cyclically and how certain factors stimulate the generation of signals and a cascade of reactions from molecular, biochemical and physiological levels, which at the end manifests annual patterns of abundance and reproduction. Environmental changes occur in time scale (daily, seasonal, interannual) and spatial scale (latitudinal, depth, altitude) and have a strong impact on growth and development of the species, especially those with sessile characteristics. The purpose of this study was to characterize the phenology (seasonal and latitudinal) of abundance, reproduction, photosynthesis and antioxidant capacity of two macroalgae with ecological and economic importance, Porphyra spp. (Rhodophyta) and Lessonia spp. (Phaeophyceae), distributed along the coast north and center (25° - 34°S) in Chile. The results show that seasonal changes in radiation and latitudinal temperature significantly influence the phenological and ecophysiological responses of the species studied. For Porphyra spp., the most notorious temporal adjustment involves an annual phenological development from north population in contrast to perennial populations from central and south. The physiological characteristics showed decrease in photosynthetic efficiency, pigments (chlorophyll a, carotenoids and phycobiliproteins) and soluble proteins in spring-summer, accompanied by increasing in antioxidant capacity. For Lessonia spp., although the abundance showed no seasonal changes between the populations, the most notoriously temporal adjustment occurs in physiological characteristics with decrease in photosynthetic efficiency, pigments (chlorophylls a and c, carotenoids), phenols and antioxidant capacity during the summer, followed by increase in thallus absorptance, ETRmax and NPQ. Studies on the taxonomic identity of Porphyra populations are required to distinguish between possible characteristics due to species-specific patterns from morphological or ecotypes variations. Studies in the species Lessonia near their limits of biogeographical distribution could elucidate whether the phenological and physiological differences are due to patterns species-specific or are masked by local environmental characteristics. The phenological studies and changes in the biochemical/physiological levels can subsidize new destination of biomass production and raw material from organisms economically important. Moreover, changes in typical phenological and ecophysiological patterns can give a light about environmental impacts of alterations such as global climate changes, contamination and pollution, overexploitation and interactions and dynamics between populations.
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McGregor, Bruce Jonathan. "Aspects of the biology of Porphyra (Bangiales, rhodophyta) of the Isle of Man." Thesis, University of Liverpool, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.317182.
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Yalo, Masande Nicholas. "An investigation of the natural products composition of Porphyra capensis (a red seaweed)." University of the Western Cape, 2017. http://hdl.handle.net/11394/6354.
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Magister Scientiae - MSc (Chemistry)Plants have been widely used in traditional medicine for a number of ailments, among which may be included infectious diseases such as colds, influenza, chicken pox, TB, etc. as well as lifestyle diseases such as diabetes and cancer. Seaweeds have also been shown to contribute to the maintenance of health through their nutritional and medicinal properties and recently, a great deal of interest has developed towards the isolation of bioactive compounds from marine sources due to their numerous health benefits. Furthermore, marine algae are valuable sources of structurally diverse metabolites with scientifically proven therapeutic claims. Chemical constituents of red seaweed, Porphyra capensis was investigated in this present study along with subsequent brine shrimp lethality assay analysis of the crude extracts. The compounds isolated from the plant were from the hexane (6) and butanol (2) extracts. These compounds were all isolated and purified by various chromatographic techniques, namely silica gel chromatography, Sephadex LH-20 gel as well as C18 reversed phase silica gel. The structures of the isolated compounds were analysed and characterised by NMR, GC-MS, ESI MS and FTIR spectroscopy. Eight compounds were isolated and identified as phytol, desmosterol, 9-eicosenoic acid, 5,8,11,14,17-eicosapentanoic acid, palmitic acid, methyl (E)-hexadec-9-enoate, glycerol and compound 1 (novel compound). All the compounds were isolated from Porphyra capensis for the first time. The hexane, butanol and methanol extracts were found to be non-toxic with the brine shrimp test LC50 value at least two times greater than ?g/ml.
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Oliveira, Mariana Cabral de. "Filogenia de Porphyra spp. (Rhodophyta): sequenciamento do gene nuclear para o RNA da subunidade pequena do ribossomo (rDNA 18S) e estudos morfológicos da fase Conchocelis." Universidade de São Paulo, 1993. http://www.teses.usp.br/teses/disponiveis/41/41132/tde-09082016-164600/.
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O gênero Porphyra (Rhodophyta) apresenta uma considerável importância econômica, sendo extensivamente cultivado e consumido como alimento. O gênero é representado por mais de 70 espécies e apresenta ampla distribuição geográfica, desde regiões tropicais até polares. Sua taxonomia, baseada em poucos caracteres da fase macroscópica do seu ciclo de vida, é ainda bastante problemática. Para tentar entender melhor a taxonomia e a história evolutiva de Porphyra foram utilizadas metodologias de biologia molecular e características da fase conchocelis do ciclo de vida. Verificou-se que caracteres da fase microscópica podem ser utilizados para complementar os conhecimentos taxonômicos tradicionais. Para tentar elucidar a posição filogenética do gênero Porphyra na divisão Rhodophyta e, dentro do gênero, entre espécies do Atlântico, o gene nuclear que codifica para o RNA ribossomal da subunidade pequena do ribossomo (rDNA 18S) foi amplificado através de PCR, clonado e completamente sequenciado. Foram utilizadas três espécies de Porphyra da Nova Escócia (Canadá) e duas de São Paulo (Brasil). As sequências obtidas foram alinhadas com as de alguns eucariontes e de outras algas vermelhas, incluindo uma sequência publicada de \"Porphyra umbilicalis\" da França. As árvores filogenéticas foram construídas através dos métodos de parcimônia, distancia e máxima verossimilhança. As analises mostraram que o gênero Porphyra é monofilético para as cinco espécies estudadas e constitui um dos ramos mais antigos dentro das algas vermelhas já analisados. O gênero Porphyra, subclasse Bangiophycidae, apresentou uma diferença substancial em relação aos gêneros da subclasse Florrideophycidae, sustentando assim, a divisão de Rhodophyta em duas subclasses pela taxonomia tradicional. Entre os eucariontes, Porphyra divergiu ao mesmo tempo que o nuclemorfo de Cryptomonas. O alto grau de divergência genética encontrada entre espécies de Porphyra, além de indicações do registo fóssil, na literatura, sugerem que o gênero é bastante primitivo dentro das algas vermelhas. Surpreendentemente, a sequência publicada para \"Porphyra umbilicalis\" apresentou mais de 99% de identidade com uma espécie de Palmaria que pertence à subclasse Florideophycidae; neste caso, a biologia molecular serviu para comprovar a identificação errônea do exemplar cuja sequência foi publicada. Durante a análise filogenética, verificou-se a ocorrência de um intron do grupo ICI nos genes rDNA 18S de Porphyra spiralis var. amplifolia. Esse intron ocorre na mesma posição que os introns do grupo IC1 nos rDNA 18S dos fungos Pneumocystis carinii, Protomyces inouyei e da alga verde Chlorella ellipsoidea, e apresenta identidade de sequências nos domínios P1 e P2, fora da região conservada, com o intron de Pn. Carinii. Três variantes, diferindo do tamanho da seqüencia do domínio P1, foram observados em três populações com distribuição geográfica diferente. O variante maior pode se auto-processar (\"self-splice\") in vitro. Quadros abertos de leitura estão presentes nos introns, mas não correspondem a nenhum gene conhecido. Introns estão presentes no rDNA 18S de outras espécies de Porphyra, que também podem apresentar variantes do rDNA 18S sem intronsThe red algas genus Porphyra has considerable economic importance, and some species are extensively cultivated for human food. The genus is represented by more than 70 species, and occurs worldwide. Its taxonomy, based mainly on morphological characters of the macroscopic phase of its life-cycle is still unsettled. Alternatives to try to understand better the taxonomy and evolutive history of the genus were ascertained. It was verified that characters of the microscopic, filamentous phase, of the life-cycle of Porphyra may be used to complement the traditional taxonomic studies. To try to elucidate the phylogenetic position of Porphyra relative to the other red algae, and within the genus, among isolates from different locations, nuclear-encoded small-subunit ribosomal RNA genes (18S rDNAs) were PCR-amplified, cloned and completely sequenced. Three species of Porphyra from Nova Scotia and two species from Brasil were aligned with 18S sequences of other eukaryotes, including one published sequence of \"Porphyra umbilicalis\" from France. Phylogenetic trees were constructed by parsimony, distance and maximum-likelihood procedures. Analysis of our data revealed that these Porphyra species represented one of the deepest branches so far discovered within red algae. There was a great degree of primary sequence difference between Porphyra (subclass Bangiophycidae), and the other red algae belonging to the subclasses Florideophycidae. These results support the division of red algae into two subclasses by traditional taxonomy. Among eukaryotes Porphyra diverges at the same point as the Cryptomonas nucleomorph. The great among of sequence divergence, and the fossil record suggest that Porphyra, my indeed, be a very primitive red alga. Surprisingly, the 18S RNA sequence of the French \"Porphyra umbilicalis\" does not fit in our Porphyra category; instead, it has more than 99% identity with a species of Palmaria belonging to the subclass Florideophycidae. Therefore it was concluded that \"P. umbilicalis\" with the published sequence was actually a Palmaria palmate that was misidentified. During the phylogenetic analysis it was found that a group IC1 intron occurs in nuclear 18S rRNA genes of Porphyra spiralis var. amplifolia. This intron occurs at the same position of the group IC1 introns in 18S rDNAs of the fungus Pneumocystis carinii, Protomyces inouyei and the green alga Chlorella ellipsoidea, and shares primary-structural identity with the Pn. Carinii intron in domains P1 and P2, outside the conserved core. Three size-variants, differing in amount of optimal sequence in P1, exist and are differentially distributed in geographically distinct populations. The largest variant can self-splice in vitro. Open reading frames are present, but do correspond to known genes. Introns are present in the 18S rDNAs of several other Porphyra species, that may also have intronless rDNA copies
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Dlaza, Thembinkosi Steven. "Development in culture, ecophysiology and nutritional content of three South African Porphyra (Rhodophyta, Bangiales) species." Doctoral thesis, University of Cape Town, 2011. http://hdl.handle.net/11427/10425.
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The first aim of this study was therefore to study the reproductive biology and phenology of three common Porphyra species (Porphyra aeodis Griffin, Bolton et Anderson 1999, Porphyra capensis Katzing 1843 and Porphyra saldanhae Stegenga, Bolton et Anderson 1997), which occur on the west coast of South Africa. The second aim of the study was to investigate, in culture, the ecophysiological responses of the different phases of the life histories of these threes species to various environmental variables. The third aim of this study was to quantify some important aspects of the nutritional composition of these three species and to investigate seasonal variations in these nutrients.
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Luo, Jin-Li. "Porphyrin metabolism in porphyria cutanea tarda." Thesis, Open University, 1992. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.315308.
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Guo, Rong. "Porphyrin metabolism in congenital erythropoietic porphyria." Thesis, Open University, 1992. http://oro.open.ac.uk/57392/.
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Meso-hydroxyuroporphyrin I, B-hydroxypropionic acid uroporphyrin I, hydroxyacetic acid uroporphyrin I and peroxyacetic acid uroporphyrin I have been isolated from the urine and plasma of patients with congenital erythropoietic porphyria (CEP) by high-performance liquid chromatography and characterized by liquid secondary ion mass spectrometry and chemical properties. The physico-chemical properties of these compounds have been studied. The hydroxy- and peroxyacetic acid- uroporphyrin I derivatives are the true metabolites of uroporphyrinogen I in vivo and their presence in urine and plasma is a common feature of CEP. The absence of these derivatives in duodenal aspirate and faeces suggests that they are of erythropoietic origin. The mechanism of formation of the hydroxy- and peroxyacetic acid- uroporphyrin I has been investigated. Peroxyacetic acid uroporphyrin I is formed from uroporphyrinogen I in the presence of H202 and iron while the hydroxylated uroporphyrin I derivatives are most probably produced by hydroxyl radicals generated during the formation of peroxyacetic acid uroporphyrin I. Destruction of porphyrins is found in the same reaction and can be prevented bydesferrioxamine, indicating that it is due to hydroxyl radicals. The formation of peroxyacetic acid- and hydroxyuroporphyrin I derivatives are uroporphyrinogen I concentration dependent. These derivatives can only be formed when uroporphyrinogen I is accumulated to a certain concentration (approx. 1-2 ~M) and the formation is then proportional to the uroporphyrinogen I concentration. The peroxylation reaction has been shown to take place only at the acetic acid side-chains of porphyrinogen and not at the propionic acid side-chains. The peroxylation reaction can therefore take place whenever a porphyrinogen with an acetic acid substituent is accumulated. Oral charcoal therapy failed to reduce the porphyrins accumulated in vivo in a patient with CEP. Uroporphyrin I, the major porphyrin accumulating in CEP, was not excreted into bile and interruption of the enterohepatic circulation by binding porphyrins onto charcoal therefore does not benefit CEP. It may, however, be effective in the treatment of hepatic porphyrias in which the accumulated porphyrins are mainly excreted via the gut lumen.
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Aguilar, Velasquez Blanca Yessenia. "Elucidación estructural del polisacárido del alga roja Porphyra columbina y determinación in vivo de la capacidad antioxidante e hipolipemiante." Bachelor's thesis, Universidad Nacional Mayor de San Marcos, 2015. https://hdl.handle.net/20.500.12672/4287.
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El objetivo principal de esta tesis es la elucidación estructural del polisacárido del alga roja marina Porphyra columbina, extraído en agua caliente, purificado y liofilizado, y el estudio de su actividad antioxidante en ratones e hipolipemiante en conejos. Previamente se evaluó la toxicidad aguda oral y toxicidad oral a dosis repetidas considerando que el material biológico sería expuesto a diferentes concentraciones del mismo. El análisis del espectro FT-IR y RMN-¹H muestra que el polisacárido de P. columbina tiene una típica estructura de porfirano: unidades β-D-galactosa, 4-O-α-L-galactosa-6-sulfato o 3,6-anhidro-α- L-galactosa. Los estudios de toxicidad para el caso de toxicidad aguda oral muestran ser no tóxico hasta concentraciones de 2000 mg/Kg, y para toxicidad oral dosis repetidas de 28 días a 50 mg/Kg evidencia daño hepático. Las pruebas in vivo en ratones midieron las actividades de las enzimas antioxidantes superóxido dismutasa (SOD), catalasa (CAT) y glutatión peroxidasa (GPx) así como los niveles medios de malondialdehído (MDA). Los resultados muestran incremento de las 3 enzimas evaluadas y disminución del MDA por administración intraperitoneal dosis-dependiente del polisacárido. El efecto hipolipemiante en conejos se determinó por evaluación del perfil lipídico: medición de C, TG, HDL y cálculo de LDL y VLDL. Los resultados mostraron disminución estadísticamente significativa, p < 0.05, tanto para los lípidos y lipoproteínas en evaluación en las condiciones del diseño experimental comparado con el grupo control de lipemia. El peso corporal de los conejos mostró diferencias significativas, p < 0.05, para los grupos en tratamiento.The main aim of this thesis is the structural elucidation of polysaccharide from the red seaweed Porphyra columbina, hot water extracted, purified and lyophilized, and the study of its antioxidant activity in mice and the lipid-lowering effect in Rabbits. Prior acute oral toxicity was evaluated considering the biological material would be exposed to different concentrations of the same. The IR and 1H-NMR spectrum shows that the polysaccharide of P. columbina has a typical porphyran structure: β-D-galactose, 4-O-α-L-galactose-6-sulphate or 3,6-anhydro-α-L-galactose units. The toxicity study for the case of acute oral toxicity shown to be nontoxic up to 2000 mg/Kg strength, and for repeated dose 28-day oral toxicity study to 50 mg/kg liver damage is evident. In vivo tests in mice measured the activities of antioxidant enzymes superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) as well as the mean levels of malondialdehyde (MDA). The results show increase of the 3 enzymes tested also decreased MDA by intraperitoneal administration dose-dependent polysaccharide. Hypolipidemic effect in rabbits was determined by the evaluation of the lipid profile: measurement of C, TG, HDL and LDL and VLDL was calculated. The results were statistically significant, p < 0.05, for both lipids and lipoproteins in assessment compared with control group of lipemia. Body weight of the rabbits showed significant differences, p < 0.05, for the groups in treatment. Keywords: Porphyra, porphyrano, lipid peroxidation, antioxidant, hypolipidemic, lipoprotein.
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Hana, Kucera. "Species identification and discovery in common marine macroalgae: Fucus, Porphyra and Ulva using a DNA barcoding approach." Thesis, University of New Brunswick, 2010. http://hdl.handle.net/1882/1090.
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The oceans represent a wealth of biological diversity where many species remain to be discovered and described. Among seaweeds, a paucity of morphological features by which to differentiate species means that many genera harbour overlooked or cryptic species. Fucus, Porphyra and Ulva are three common genera of marine intertidal algae and all include species that are particularly difficult to distinguish morphologically. DNA barcoding has been championed as a revolutionary tool for species identification and discovery and applying this tool to algae was a logical step due to the difficulty of morphological identification of many algal species. This thesis is part of a significant initiative aimed at identification and discovery of all species of seaweeds in Canadian waters, using a DNA barcoding approach. The original concept of DNA barcoding relied on comparing the 5’ region of the mitochondrial cytochrome c oxidase 1 (COI-5P) gene among animal species. In this study, DNA barcoding with COI-5P was applied to the brown algal genus Fucus and worked as well as any other marker to assign morphologies to known species. The DNA barcoding results also uncovered substantial phenotypic diversity in Pacific F. distichus. Results were confirmed by comparison with sequences of the nuclear internal transcribed spacer region (ITS). For Porphyra, COI-5P DNA barcoding was compared with species identification using the chloroplast large rubisco subunit (rbcL) and the Universal Plastid Amplicon (UPA) in a floristic survey of Canadian Porphyra species. Two new species were discovered and described (Porphyra corallicola and Porphyra peggicovensis), and P. cuneiformis was synonymized with P. amplissima. The COI-5P emerged as the best marker for species discrimination despite difficulties with primer universality. To aid in choosing a marker for DNA barcoding for green algae, the universality and species discriminatory power of the rubisco large subunit (rbcL) (considering the 5’ and 3’ fragments independently), the UPA, the D2/D3 region of the nuclear large ribosomal subunit (LSU-D2/D3) and the ITS were evaluated. While the rbcL-3P highlighted several cryptic species, and worked well to distinguish Ulva species, more research is needed to recommend a marker for DNA barcoding generally in marine green macroalgae.
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Hafting, Jeff T. "Strategies for growth management of Porphyra yezoensis(ueda) blades in suspension cultures, a step towards land-based mariculture." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp03/NQ27152.pdf.
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Blouin, Nicolas Achille. "Asexual Reproduction in Porphyra umbilicalis (L.) Kützing and Assessment of its Use in Integrated Multi-trophic Aquaculture (IMTA)." Fogler Library, University of Maine, 2006. http://www.library.umaine.edu/theses/pdf/BlouinNA2006.pdf.
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Holmes, Mary Jane. "Phenology and observations on the morphology, cytology and life history of species of Porphyra (Bangiales, Rhodophyta) from Britain." Thesis, Bath Spa University, 2004. http://researchspace.bathspa.ac.uk/1451/.
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Morais, Tania N. "Phosphorus, nitrogen, and carbon nutrition in fresh and starved gametophytes of the red alga Porphyra purpurea (Roth) C. Agardh and occurrence of polyphosphates." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0030/MQ65511.pdf.
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Azevedo, Vítor Manuel Madureira. "Lipidomic study of the red marine macroalgae as source of bioactive compounds." Master's thesis, Universidade de Aveiro, 2016. http://hdl.handle.net/10773/17513.
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Mestrado em Mestre em Bioquímica, ramo da Bioquímica ClínicaMarine macroalgae, or seaweeds, have gained an increased interest in recent times for the use in various biotechnological applications, due to the added-value of their chemical constituents. Among them, glycolipids and phospholipids display several commercial applications in a wide spectrum of industries, such as food, pharmaceutical and cosmetic. In an effort to further understand the lipid composition of macroalgae, the present work reports, for the first time, the isolation and characterization of the polar lipid profile of the red macroalgae Porphyra dioica cultivated on a land-based integrated multi-trophic aquaculture (IMTA) system, using a lipidomic-based approach employing hydrophilic interaction liquid chromatography-eletrospray ionization mass spectrometry (HILIC-ESI-MS). The fatty acid profile of this species of seaweed was also determined, accounting for season variability and its life cycle. The polar lipid profile of P. dioica revealed the presence of over 69 molecular species, corresponding to glycolipids (sulfoquinovolsyldiacylglycerols, sulfoquinovosylmonoacylglycerols, digalactosyldiacylglycerols) and glycerophospholipids (lyso- and phosphatidylglycerols), lyso- and phosphatidylcholines), as well as phytyl derivatives. Some of these polar lipids contain polyunsaturated fatty acids (PUFAs), namely arachidonic acid (C20:4) and eicosapentaenoic acid (C20:5), thus revealing the ability of P. dioica to biosynthesize this long chain PUFAs. P.dioica from the winter season revealed to be richer in PUFA content, accounting for 37.0% of total fatty acid (TFA) content, as opposed to P. dioica from the summer season (25.0% of TFA content). Eicosapentaenoic acid (EPA) content was revealed to be being significantly higher in the winter season (25.2% of TFA content). The diploid sporophyte conchocelis phase of P. dioica showed to possess the highest amount of PUFAs (47.0% of TFA content), with arachidonic acid being the most abundant fatty acid (21.2% of TFA content). Several of the lipids identified have been reported to possess nutritional and health benefits, thus allowing the valorisation of P. dioica from IMTA as a source of bioactive compounds, adequate for the use in a wide range of different applications and as a functional food, rich in omega-3 fatty acids.
As macroalgas têm vindo a ganhar um interesse cada vez maior para o uso em diversas aplicações biotecnológicas, devido ao valor acrescentado dos seus diferentes constituintes. Entre estes, os glicolípidos e os fosfolípidos podem ser usados comercialmente em diferentes indústrias, tais como as indústrias alimentar, farmacêutica e cosmética. Com o objetivo de compreender melhor a composição lipídica das macroalgas, o presente trabalho relata, pela primeira vez, a caracterização do perfil de lípidos polares da macroalga vermelha Porphyra dioica, cultivada num sistema de aquacultura multi-trófica integrada (IMTA), utilizando para esse fim uma abordagem lipidómica baseada na espectrometria de massa (HILIC-ESI-MS). Foi também determinado o perfil de ácidos gordos da referida espécie de alga, tendo em consideração a variabilidade sazonal e o seu ciclo de vida. O perfil de lípidos polares da alga P. dioica revelou a presença de mais de 69 espécies moleculares diferentes, correspondendo a classes de glicolípidos (sulfoquinovosildiacilgliceróis, sulfoquinovosilmonoacilgliceróis e digalactosildiacilgliceróis), fosfolípidos (liso- e fosfatidilglicerol, liso- e fosfatidilcolinas) e derivados fitil. Alguns destes lípidos polares contêm ácidos gordos polinsaturados (PUFAs) na sua composição, nomeadamente o ácido araquidónico (C20:4) e ácido eicosapentaenóico (C20:5), revelando, assim, a capacidade da alga P. dioica em biossintetizar este tipo de ácidos gordos polinsaturados de cadeia longa. Considerando a variação sazonal do conteúdo em ácidos gordos, a P. dioica cultivada no inverno revelou ser mais rica em PUFAs, correspondendo a 37.0% do conteúdo total de ácidos gordos, contrariamente à P. dioica cultivada no verão (25.0%). O conteúdo em ácido eicosapentaenóico (EPA) é significativamente maior na estação de inverno (25.2%). O perfil em ácidos gordos também variou com o ciclo de vida P. dioica, sendo que na fase de conchocelis a quantidade de PUFA é significativamente mais elevada (47.0% de conteúdo de ácidos gordos), sendo o ácido araquidónico o ácido gordo mais abundante (21.2% de conteúdo de ácidos gordos).Várias classes de lípidos polares foram identificados como possuindo benefícios nutricionais e para a saúde, permitindo assim a valorização da alga vermelha P. dioica produzida em IMTA como uma fonte de compostos bioativos, adequados para o uso numa grande variedade de aplicações como um alimento funcional, rica em ácidos gordos polinsaturados ómega-3.
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Lecerf, Adrien. "Ordre et variation : essai sur le système de Jamblique." Thesis, Paris, EPHE, 2015. http://www.theses.fr/2015EPHE5071.
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Cette thèse se propose de donner une synthèse générale du système du néoplatonicien Jamblique de Chalcis, acteur important de l’évolution de la métaphysique grecque durant l’âge antique tardif. Elle reconstruit tour à tour sa doctrine psychologique, sa hiérarchie des êtres et quelques-uns de ses concepts fondamentaux, en mettant l’accent sur l’histoire des idées entre le fondateur de l’école, Plotin, et la naissance de l’école néoplatonicienne d’Athènes. L’ensemble des œuvres laissées par Jamblique est exploité, ainsi que les quelque 800 fragments et témoignages sur sa vie et sa doctrine laissés par les auteurs postérieurs. Les influences subies sont analysées et replacées en contexte : néoplatonisme de Plotin et Porphyre, qui donne à Jamblique les principaux niveaux de son ontologie, qu’il analyse et fractionne ; médio-platonisme, dont le néoplatonisme hérite des topiques philosophiques ; aristotélisme, qui lègue une conception dynamique de l’âme et une hiérarchie des puissances cognitives consacrant la transcendance de l’intellect ; pythagorisme, qui permet à Jamblique de concevoir les mathématiques comme un langage valable pour la description de toutes les parties de la philosophie. Par l’ampleur de son œuvre ainsi que l’originalité et la fermeté des solutions apportées aux problèmes traités, Jamblique crée une synthèse puissante qui sert de base doctrinale aux écoles néoplatoniciennes tardives d’Athènes et Alexandrie, et est profondément représentative d’un âge théocentrique, où l’âme humaine n’est qu’un principe dérivé, qui doit prendre sa place dans l’ordre universel des choses : une métaphysique de l’unité, reposant sur la dualité dynamique de l’ordre et de sa variationThis thesis strives to provide modern research with a synthesis of the system of Iamblichus of Chalcis, an important figure in the development of later Greek metaphysics. It reconstructs in turn his psychology, his hierarchy of being and some of his most basic concepts and philosophical laws, with a stress on the continuity between Plotinus, founder of the Neoplatonic school, and the beginnings of the school of Athens. The whole of Iamblichus’ body of work is exploited, as well as the 800 fragments and testimonia on his life and doctrine handed down to us by later authors. Influences received are analysed and set in context: Plotinus’ and Porphyry’s Neoplatonism, which provides the general levels of reality which Iamblichus tried to analyse and enrich; Middle Platonism, whose topics are debated in Neoplatonism; Aristotelianism, which accounts for a dynamic conception of the human soul and a hierarchy of cognitive powers beginning with the transcendent Intellect; Pythagoreanism, which allows Iamblichus to depict mathematics as a universal language, able to take the mark of all parts of philosophy. By the scope of his work and the originality and neatness of the solutions he provided to problems which nascent Neoplatonism had to confront, Iamblichus is able to create a powerful synthesis which acts as a doctrinal basis for the later schools of Athens and Alexandria: it is profoundly representative of a theocentric era, in which human soul is but a derived principle that has to keep its place in the grand scheme of being. It is a metaphysics of unity, founded on the dual dynamic of order and variation
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Church, S. "The Chester porphyria." Thesis, University of Liverpool, 1986. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.382053.
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Innala, Eva. "Acute intermittent porphyria, women and sex hormones. Screening for hepatocellular carcinoma in porphyria." Doctoral thesis, Umeå universitet, Obstetrik och gynekologi, 2010. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-36884.
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Background: Porphyrias are inherited disorders with impaired heme biosynthesis. Acute intermittent porphyria (AIP) is the most common porphyria in Sweden. AIP attacks may be life-threatening. Female sex hormones are regarded as important precipitating factors. Hepatocellular carcinoma (HCC) is a severe complication in the older AIP population. The aim of the thesis was to describe the clinical expression of AIP in women, experience of hormonal contraception and hormonal replacement therapies (HRT) and of pregnancies. Secondly, we evaluated gonadotropin-releasing hormone (GnRH) agonist treatment for prevention of menstrual-cycle-related AIP attacks. Thirdly, we evaluated whether an altered sex-steroid metabolism was present in AIP women compared with controls. Finally, we evaluated the benefit of screening for HCC in AIP in a 15-year follow-up study. Methods and results: In a retrospective population-based study in northern Sweden, 166 female AIP gene carriers ≥18 years of age participated. Manifest AIP (MAIP) was reported in 55%; 82% had severe attacks and 39% had menstrual-cycle-related attacks. Hormonal contraceptives were used by 94, and 12 reported that this precipitated AIP attacks. HRT and local vaginal treatments in menopause did not precipitate AIP attacks. Only 10% reported impairment of AIP symptoms during pregnancy. In the retrospective follow-up study of GnRH-agonist treatment, 11 of 14 women improved during treatment. Porphyria attacks were triggered in two women after estradiol add-back and in 5 of 9 women after progesterone add-back. In the sex-steroid metabolism study, levels of s-progesterone, estradiol, allopregnanolone and pregnanolone during the menstrual cycle in 32 AIP gene carriers were compared with 20 healthy controls. Progesterone metabolism in the AIP group differed from controls. In the AIP group levels of allopregnanolone, but not pregnanolone, were significantly lower. In the prospective HCC screening study AIP gene carriers aged >55 years were included. On average 62 subjects participated during 15 years. HCC was diagnosed in 22 of 180 eligible AIP gene carriers in the region (male:female, 12:10, 73% MAIP). The annual incidence of HCC was 0.8%. The risk of HCC was 64-fold higher than in the general population over 50 years of age in this region, and even higher for AIP women (93-fold). Increased 3- and 5-year survival was seen in the regularly screened AIP group. Liver lab tests were not useful in HCC screening. Conclusion: The clinical expression of AIP in women is pronounced and menstrual-cycle-related attacks are common. Hormonal contraceptives can induce AIP attacks and caution is recommended. GnRH-agonist treatment can ameliorate menstrual-cycle-related attacks of porphyria. Dose findings for GnRH-agonists and add-back regimes, especially for progesterone, are intricate. Progesterone metabolism in the AIP group differs from that in healthy controls. HCC screening in AIP gene carriers >50 years of age enables early diagnosis and a possibility for curative treatments. Annual HCC screening with liver imaging is recommended in AIP gene carriers >50 years of age.
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Wimmershoff, Frank. "Porphyria cutanea urämica Unterschiede zwischen Hämodialysepatienten mit und ohne Porphyria cutanea-artigen Hautveränderungen /." [S.l.] : [s.n.], 2004. http://deposit.ddb.de/cgi-bin/dokserv?idn=972391541.
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Li, Yang. "Geochronology and fluid evolution of the Qulong porphyry system : implications for porphyry deposit formation." Thesis, Durham University, 2016. http://etheses.dur.ac.uk/11869/.
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Understanding the metal enrichment process and rate in porphyry Cu systems (PCS) is critical to underpin the genetic model of PCS and refine the template for exploration, of which robust temporal constrain is the key. In addition, fluid evolution paths constrained by bulk analysis potentially suffer problems of contamination. Based on detailed field geology and petrographic study, this PhD thesis addresses the timescales and fluid evolution process of the world class Qulong porphyry Cu-Mo deposit, Tibet, China, by applying high precision geochronology and high spatial resolution isotope analysis. A fluid inclusion study indicates that the bulk mineralization at Qulong was deposited between 425 and 280 oC under hydrostatic pressure conditions. The depth of formation of the Qulong porphyry Cu-Mo system is estimated at ~2.7 km, which implies ~2.3 km of erosion has occurred since its formation. Zircon CA-ID-TIMS U-Pb geochronology constrains the emplacement ages of the Rongmucuola pluton, the P porphyry and quartz aplite to 17.142 ± 0.014/0.014/0.023 (analytical/plus tracer/plus decay constant uncertainty), 16.009 ± 0.016/0.017/0.024 and 15.166 ± 0.010/0.011/0.020 Ma, respectively. Molybdenite ID-NTIMS Re-Os geochronology suggests that the bulk mineralization at Qulong was deposited through multiple shorted lived pulses (~ tens of kyrs) between 16.126 ± 0.008/0.060/0.077 and 15.860 ± 0.010/0.058/0.075 Ma, with a duration of 266 ± 13 kyrs. Quartz SIMS oxygen isotope analysis indicates a periodic interplay between meteoric and magmatic fluids and continuing increase of meteoric water from ~10 to ~25 % volume percent during the ore-forming process. As a result meteoric water is invoked as the main trigger for metal deposition at Qulong. The major conclusions of this study from Qulong are supported by numerical modelling, titanium diffusion and high precision studies, and have implications for understanding porphyry systems worldwide, for example, multiple and cyclic magmatic-hydrothermal fluid pulses cooled by meteoric water are fundamental for ore formation.
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Ong, Patricia Mei Lin. "Pathophysiology of acute intermittent porphyria." Thesis, University of Glasgow, 1996. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.318116.
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Holley, Ann E. "Studies on experimental hepatic porphyria." Thesis, University of Surrey, 1987. http://epubs.surrey.ac.uk/847524/.
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Intraperitoneal administration of 3,5-diethoxy-carbonyl-1,4-dihydrocollidine (DDC) to female C3H/He/01a and NIH/01a inbred mice produced a marked dose-dependent loss of hepatic ferrochelatase (FK) activity, induction of g-aminolaevulinic acid synthetase (ALA-S) and accumulation of protoporphyrin. There was no strain difference in the degree of FK inhibition. However, induction of ALA-S was greater in C3H/He/01a mice. The strain difference in ALA-S response was most marked when inhibition of FK (the "specific" effect of DDC) was maximal and this suggests that a genetic variation exists in the sensitivity of ALA-S to a second, "non-specific" action of DDC, possibly related to its property of lipid-solubility. A sex difference in griseofulvin (GF)-induced porphyria was found with a greater hepatic protoporphyrin accumulation in male mice of all three strains examined. Stimulation of ALA-S activity was slightly greater in males, but when porphyria was very marked, ALA-S levels were significantly lower in this sex. These, and other, results demonstrated a two-way relationship between ALA-S activity and porphyrin accumulation, with a repression of ALA-S activity occuring at high liver protoporphyrin concentrations. Using a new method to add drugs in solution to cultures of chick embryo hepatocytes, the porphyrogenic effects of various drugs was compared. DDC and ISO-griseofulvin markedly inhibited FK activity and caused accumulation of protoporphyrin. In this system, ISO-griseofulvin was a more potent inhibitor of FK activity than either GF or HET-griseofulvin and also produced a greater accumulation of protoporphyrin, as previously reported in rodents. The hepatic green pigment accumulating in DDC, GF and ISO-griseofulvin-treated mice has been isolated, purified and identified as N-MePP, a previously established inhibitor of FK. All four possible structural isomers were demonstrated and each drug produced primarily the same isomer. An additional hepatic green pigment has been isolated from GF-treated mice, and spectral characteristics suggest this pigment is also an N-mono-substituted porphyrin, but its identity has not yet been established.
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Meissner, Peter Nicholas. "Enzyme studies in variegate porphyria." Thesis, University of Cape Town, 1990. http://hdl.handle.net/11427/25672.
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Pizarro, Martínez Héctor Orlando. "Les traceurs minéralogiques comme indicateurs de porphyres cuprifères dans les remplissages sédimentaires des bassins adjacents, désert d'Atacama, Chili." Thesis, Toulouse 3, 2019. http://www.theses.fr/2019TOU30105.
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Les gisements de cuivre porphyrique (PCDs) sont liés au magmatisme calco-alkalins produit le long d'une marge tectonique convergente et résultent de la circulation de fluides hydrothermaux dérivés de magmas felsiques oxydés, hydratés et à faibles profondeurs. Au cours de l'évolution des systèmes magmatiques et hydrothermaux, les interactions fluide-roche génère des minéraux de l'altération hydrothermale typiques et peut également modifient ou génèrent des minéraux accessoires avec des signaux différents qui peuvent être associés à chaque étape de l'évolution du système, ce qui pourraient être distinguées par les caractéristiques physico et chimiques des minéraux accessoires hérités (zircon), des minéraux modifiés (apatites) ou des minéraux nouvellement formés (oxydes de Fe-Ti). Dans le désert d'Atacama, les bassins hydrographiques exposés le long de l'avant-arc occidental sont remplis de dépôts de gravier provenant de l'érosion de la Cordillère de Domeyko, en réponse à la phase tectonique éocene Incaique. On peut émettre l'hypothèse que certains de ces bassins contiennent des preuves minéralogiques qui qui vient de la dénudation des systèmes minéralisés en cuivre-porphyre situés en amont. L'objectif principal de cette thèse est donc de trouver des preuves magnétiques, minérales et chimiques qui permettront de relier la dénudation des PCDs aux sédiments déposés dans les bassins adjacents. Pour tester cette relation, nous comparons les caractéristiques magnétiques des roches et pétrographique et géochimique des minéraux accessoires (zircons et apatites) dans quatre PCDs situés dans la Cordillère de Domeyko (Chuquicamata, Mirador, Esperanza et Escondida), avec les mêmes caractéristiques des sédiments remplissant un bassin proche du district minier de Centinela. Dans ces PCDs, des caractéristiques pétrographique et géochimique distinctes des minéraux accessoires associées à la fertilité en cuivre ont été trouvés. Dans les zircons, la plus grande fertilité correspond aux signatures géochimiques : Hf > 8 750 (ppm), Eu / Eu* > 0,4, 10 000 x (Eu / Eu *) / Y> 1, (Ce / Nd) / Y> 0,01, Dy / Yb <0,3, Th / U < 1 -> 0,1), ce qui peut être lié à un état d'oxydation élevé et à une teneur élevée en eau magmatique dans le magma. Dans les apatites, les caractéristiques les plus distinctives de la fertilité en cuivre sont la couleur de luminescence verte, les valeurs élevées de Ca et la faible teneur en oligo-éléments, tels que Mg, Na, Cl, qui peuvent être liées à l'évolution des fluides hydrothermaux. Bien que le signal magnétique des PCDs soit contrôlé par la présence d'oxydes Fe-Ti d'origine hydrothermale et magmatique, il n'a pas été possible de différencier la contribution de ces deux composantes. Dans le bassin, il existe un dépôt de gravier (Tesoro) contenant un nombre important de zircons et d'apatites indicateurs de fertilité métallogénique des PCDs, qui coïncide avec une minéralisation de Cu exotique. On observe également une diminution des valeurs de susceptibilité magnétique des niveaux inférieurs aux niveaux supérieurs, qui est principalement contrôlée par la concentration en oxydes de Fe-Ti à grains grossiers d'origine détritique. La concentration la plus élevée en oxydes de fer pourrait être associée à un climat aride et à une influence tectonique, alors que la diminution de la concentration peut être liée à une tendance à l'aridification et / ou à un éloignement relatif des sources de ces oxydes. En conclusion, les apatites et les zircons détritiques des bassins ont le potentiel de documenter la dénudation des PCDs en amont. Par conséquent, l'utilisation de minéraux indicateurs représente une technique d'exploration potentiellement efficace qui peut facilement s'appliquer à la recherche de preuves concrètes de PCD contenues dans des dépôts de gravier. D'autre part, les propriétés magnétiques des sédiments nous renseignent sur les conditions paléo-climatiques et / ou tectoniques de leur dépôtPorphyry copper deposits (PCDs) are linked to calk-alkaline magmatism produced in a convergent tectonic margin and resulted from the circulation of hydrothermal fluids derived from oxidized and water rich felsic magmas emplaced at shallow depths. During the evolution of the magmatic and hydrothermal systems, the fluid-rock interaction generates typical hydrothermal alteration minerals and can also modify or generates accessories minerals with different properties that can be associated at each stage of the evolution of the system, which could be distinguished by the physico and geochemical characteristics of the inherited accessory minerals (zircon), the modified minerals (apatite) or the newly formed minerals (Fe-Ti oxides). In the Atacama Desert hydrographic basins exposed along the western forearc are filled by gravel deposits which were derived from the erosion of the Domeyko Cordillera in response to the Eocene Incaic tectonic phase. It can be hypothesized that some of these basins contain mineralogical evidences that come from the denudation of porphyry copper mineralized systems located upstream. Therefore, the main goal of this thesis is to find magnetic, mineral and chemical evidences that will help to link the denudation of PCDs with sediments deposited in adjacent basins, mainly by using heavy minerals and magnetic signals as tracers contained in the sedimentary record. To test this relationship, I compare the rock-magnetic properties and physical and geochemical characteristics of minerals (zircon and apatite) in four selected DPCs located in Domeyko Cordillera (Chuquicamata, Mirador, Esperanza and Escodida), with the same characteristics in detrital sediment filling a close basin in the Centinela Mining District. In the studied PCDs, accessory minerals with distinctive physical and geochemical characteristics associated with metallogenic fertility were identified. In zircons, the most fertile samples correspond to these geochemical signatures: Hf > 8,750 (ppm), Eu/Eu* > 0.4, 10.000 x (Eu/Eu*)/Y > 1, (Ce/Nd)/ Y > 0.01, Dy/Yb < 0.3, Th/U < 1 - > 0.1), which can be linked to high oxidation state and high content of magmatic water in the magma. In apatite, the most relevant features indicating fertility are the green luminescence color and high Ca values and low content of trace elements, such as Mg, Na, Cl, which can be related to the evolution of hydrothermal fluids. Although the magnetic signal from DPCs is controlled by the presence of Fe-Ti oxides of hydrothermal and magmatic origin, their characteristics could not be used to differentiate the contribution of these two components. In the stratigraphic record there is a gravel deposit (Tesoro) which contains an important number of zircons and apatite which can be signaled as indicators of metallogenic fertility, that coincides with exotic-Cu mineralization and abundant clasts coming from different hydrothermal alteration zones related to PCDs. In the gravel deposits, a decrease in the magnetic susceptibility values from lower to upper levels is observed, which is mainly controlled by coarse-grain Fe-Ti oxides concentration of detritic origin. In the gravel deposits, rock magnetic properties are mainly controlled by Fe-Ti oxides concentration of detritic origin, where the highest concentration of Fe-minerals could be associated to arid climatic conditions and a rapid tectonically-controlled denudation, whereas the decline in concentration can be related to an aridification trend and/or sources changes
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Wessendorf, Florian. "Supramolecular fullerene-porphyrin architectures = Supramolekulare Fulleren-Porphyrin-Architekturen." kostenfrei, 2010. http://d-nb.info/1000613593/34.
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Beavington, Richard. "Porphyrin arrays." Thesis, University of Oxford, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.388909.
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Promarak, Vinich. "Porphyrin arrays." Thesis, University of Oxford, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.249614.
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Zhang, Wei. "Porphyrin arrays." Thesis, University of Oxford, 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.494395.
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Hift, R. J. "Variegate porphyria : molecular aspects of variegate porphyria in South Africa and their biochemical and clinical consequences." Doctoral thesis, University of Cape Town, 2000. http://hdl.handle.net/11427/3398.
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Bibliography: p. 215-241.Variegate porphyria (VP) is the clinical disorder associated with a deficiency of the haemsynthesising enzyme protoporphyrinogen oxidase (PPO). VP is one of the commonest monogenic inherited disorders in South Africa. The clinical effects include photocutaneous sensitivity and the development of potentially life-threatening acute porphyric crises. Section 1 of this dissertation examines the molecular basis for VP in South Africa.
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Tannert, Sebastian. "Energy and electron transfer in porphyrin-phthalocyanin-porphyrin heterotrimers." Doctoral thesis, Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät I, 2013. http://dx.doi.org/10.18452/16850.
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Diese Dissertation leistet einen Beitrag zum Verständnis des Energie- und Elektronentransfers innerhalb von neuartigen supramolekularen Strukturen, die aus einem zentralen Phthalocyanin und zwei axial angekoppelten Porphyrinen bestehen. Zwei solcher Trimere, welche die koordinative Ankopplung von Porphyrinen über ein Silizium-Zentralatom des Phthalocyanins nutzen, wurden im Rahmen der Arbeit zum ersten Mal quantitativ bezüglich auftretender innermolekularer Transferprozesse charakterisiert. Ziel war die Beantwortung der Frage, ob diese Substanzklasse die wunschgemässe Vereinigung von Lichtsammlung und Ladungstrennung ermöglicht. Aus der Kombination der Messdaten, aufgenommen mit einer Vielzahl von Messverfahren, konnten für die beiden untersuchten Trimere in zwei unterschiedlich polaren Lösungsmitteln die Ratenkonstanten der Energie- und Ladungstransferkanäle ermittelt werden. In allen Fällen findet ein effizienter Ladungstransfer von den Porphyrinen zum Phthalocyanin und ein Lochtransfer vom Phthalocyanin zu einem der beiden Porphyrine statt. Dieses Ergebnis bestätigt die Erwartung, dass Lichtsammlung und Ladungstrennung in diesem Molekül vereint auftreten. Zusätzlich zu den beiden oben erwähnten Prozessen findet je nach Lösungmittelpolarität und Struktur der Porphyrine ein dem Energietransfer paralleler Elektronentransfer und ein Ladungsrücktransfer statt. Allerdings zerfällt der ladungsseparierte Zustand zu schnell, was eine praktische Nutzung der untersuchten Verbindungen in Solarzellen noch verhindert und ihre Weiterentwicklung erfordert.This thesis contributes to the comprehension of energy and electron transfer within novel supra-molecular structures, denominated triads, consisting of a central phthalocyanine axially-coupled to two porphyrins. In the course of this thesis, two of the trimers, were quantitatively characterized regarding their intramolecular transfer processes. Both feature a dative bond between the porphyrins and the phthalocyanine via the central silicium atom of the latter. These investigations aimed at answering whether this class of compounds allows the desired combination of light harvesting and charge separation. The rate constants of both investigated trimers in two solvents with different polarity were determined by the combination of data from a variety of measurement methods. An efficient charge transfer from the porphyrins to the phthalocyanine and a hole transfer from the phthalocyanine to one of the porphyrins occurs in all investigated cases. This result confirms the prospect that light harvesting and charge separation can occur combined in one molecule. Depending on solvent polarity and the structure of the porphyrines, electron transfer parallel to the energy transfer and a charge back transfer takes place in addition to both above-mentioned processes. However, the charge-separated state of the investigated substances decays to fast, still preventing a practical utilization of these compounds in solar cells and necessitating further developments.
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Rappé, Charles J. "Porphyry and the Platonic-Aristotelian tradition." [S.l. : s.n.], 2002. http://www.freidok.uni-freiburg.de/volltexte/599.
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McFall, Katie Anne. "Critical metals in porphyry copper deposits." Thesis, University of Southampton, 2016. https://eprints.soton.ac.uk/412122/.
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Critical metals are elements essential to high-tech industry and green technology which are associated with a significant supply risk. Diversifying supplies of these elements is therefore a high priority. Porphyry copper deposits contain potentially economic enrichments of some of these elements, namely rhenium, platinum group elements (PGEs), bismuth and tellurium. This thesis investigates the source, transport mechanism and distribution of these critical elements in two post-collisional Tethyan porphyry deposits. The Muratdere Cu-Mo (Au-Re) porphyry deposit, Turkey, described here for the first time, contains two generations of molybdenite with contrasting Re concentrations. The early, Re-poor molybdenites have magmatic δ34SCDT values, while the late, vein hosted Re-rich molybdenite has δ34SCDT values matching those of the surrounding country rock suggesting that the additional Re has been sourced from hydrothermal fluid-country rock interaction. The Skouries Cu-Au porphyry deposit, Greece, is PGE, Te and Bi enriched. In contrast to Muratdere, Skouries is shown to be an orthomagmatic system hosted by a series of overprinting dykes, with the metal enrichment hypothesised to have been provided by periodic mafic recharge of a deeper source magma chamber. The mineralising fluids in Skouries are shown to have been highly oxidised and hypersaline with complex cation chemistry (Na, K, Fe, Mn and Ca), and with the overall fluid evolution progressing from an early CO2 rich fluid to a later brine. The PGEs in the deposit are located in the main hypogene mineralising veinsets, associated with potassic alteration, and are found to be hosted in bismuth and tellurium complexes. A variety of platinum group minerals are identified, including sopcheite (Ag4Pd3Te4) and sobolevskite (PdBi). LA-ICP-MS of fluid inclusions, combined with microthermometry, has shown gold, bismuth and palladium to be hydrothermally transported by high temperature ( > 500°C), high salinity ( > 65 wt% NaCl+KCl) and highly oxidised fluids, and a bismuth-tellurium collector model is proposed to allow concentration of palladium from under-saturated fluids into platinum group minerals. High semi-metal (Te and Bi) contents in porphyries are therefore proposed to be an indicator of PGE enrichment.
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André-Mayer, Anne-Sylvie. "Fluides et fracturations dans les gisements de type porphyre et épithermal." Nancy 1, 2000. http://www.theses.fr/2000NAN10176.
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En métallogénie, il est admis depuis longtemps que les fluides sont les principaux vecteurs des métaux et que fluides et déformations sont étroitement associés dans le déroulement des processus minéralisateurs. Ce travail aborde ces deux principaux aspects en environnement porphyre et épithermal où de nombreuses inconnues subsistent en ce qui concerne les processus minéralisateurs, l'origine dès fluides minéralisateurs ainsi que le rôle joué par les drains de cas fluides à savoir les fractures. L'étude des fluides réalisée dans le district épithermal de Shila (SW Pérou) a permis de proposer un modèle de minéralisation pour l'ensemble des gisements du district. Les différences observées dans la nature des fluides et dans leurs propriétés PVT semblent expliquer les différents types et· styles de minéralisation. A Apacheta, l'étude de l'évolution verticale des paramètres physico-chimiques des fluides en parallèle de la minéralisation montre que la différence de minéralisation observée entre les niveaux profonds (Pb-Zn) et plus superficiels (Au-Ag) est lié à un fractionnement des gaz présents dans les fluides lors d'un phénomène d'ébullition. L'étude de la géochimie des fluides (crush-leach) associés à ce type de minéralisation dans différents districts (Shila, Pérou; Baia Mare et Monts Apuseni, Roumanie, Pongkor, Indonésie) montre que ces fluides présentent des chimies comparables quel que soit leur contexte géodynamique. Ces compositions sont également similaires aux fluides associés aux systèmes géothermiques. Des analyses des propriétés de réseaux de fractures ont été réalisé à échelle macroscopique sur des systèmes de veines qu'elle soient minéralisées ou non. Elles ont permis dans un premier temps d'établir une nouvelle méthode pour caractériser des paléocontraintes en tenant compte de l'influence de la présence de fluides. Appliquée sur le réseau de veines de Soultz-sous-Forêts, cette méthode donne des valeurs réalistes de paléocontraintes à l'origine de la réouverture d'un système de veines en présence de fluides. Différentes techniques d'études géométriques et statistiques permettant la caractérisation des propriétés d'un réseau de fractures ont également été appliquées sur le stockwerk minéralisé du porphyre cuprifère de Rosia Poienî (Roumanie). Les hétérogénéités constatées dans les caractéristiques du stockwerk (à l'échelle métrique) semblent se traduire directement pas des variations dans les teneurs en cuivre. La description statistique des propriétés du stockwerk minéralisé semble être un outil prospectif très intéressant. La caractérisation des propriétés hydrauliques des veines constitutives du stockwerk met également en évidence des hétérogénéités à l'échelle de la carrière. Les niveaux les plus profonds et les plus minéralisés sont dominés par des perméabilité de drains et une organisation de veines en clusters. Les niveaux les plus superficiels développent quant à eux de faible perméabilité de fissures, sans drains majeurs entraînant de ce fait une perméabilité pervasive dans la masseIn metallogeny, it is now obvious that fluids are the main vectors of metals and that fluids and deformations are closely associated in the mineralizing processes. This work deals about this two main aspects in the porphyry and epithermal environment. Fluid studies, realised in the epithermal district of Shila (SW Peru), allow to state a mineralizing model at the district scale. The differences observed in the PVT properties of the fluids seem to explain the different types and styles of mineralization. At Apacheta, studies of the vertical evolution of the physico-chemical parameters of the fluids in parallel to the mineralization show that differences, observed between deep levels (Pb-Zn) and shallower levels (AuAg), is directly linked to a fractionation of gases present in fluids during a boiling event. The geochemistry (crush-leach) of the fluids associated to this type of mineralization in various districts (Shila, Pero; Baia Mare and Apuseni Moutains, Romania; Pongkor, Indonesia) are similar whatever their geodynamic context and are comparable with the fluids associated to geothermal systems. Analyses of fracture networks has been realised at macroscopic scale on different (mineralized or not) vein systems. They allow in a first time to establish a new methodology to characterize paleostresses taking into account the influence of the fluid pressure. Applied on the Soultz-sous-Forêts vein system, this method gives realistic paleostress magnitudes linked to the reopening of quartz veins. The mineralized stockwerk of the Rosia Poieni porphyry copper (Apuseni Mts, Romania) has been chosen for a statistical and hydraulic characterization in order to understand how mineralized vein system evolve and grow. A 1D sampling of the stockwerk has been realized on 2000 fractures distributed on five levels of the open pit (910, 940, 1000, 1045 and 1060 ml. Various statistical analyses has been applied and heterogeneities observed in the stockwerk (metric scale) express directly variations in the copper content. Statistical description of the stockwerk properties seems thus to be a very powerful prospective tool. Estimation of hydraulic conductivities developed by veins has been realized and show equally heterogeneities at the quarry scale. The mean permeability developed by all the veins on each profile decrease from the deeper and more mineralized level (910m) to the highest level (1060m). High permeabilities developed on the 910 m profile are linked to the presence of major drains and the clustered organization of veins. The level 1060 m, characterized by numerous and thin veins with a homogeneous spatial repartition, develop a more pervasive permeability
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Panton, Nicola. "Mutation analysis of four genes implicated in iron homeostasis in porphyria cutanea tarda (PCT) patients." Thesis, Link to the online version, 2008. http://hdl.handle.net/10019/888.
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Valencia, Victor A. "EVOLUTION OF LA CARIDAD PORPHYRY COPPER DEPOSIT, SONORA AND GEOCHRONOLOGY OF PORPHYRY COPPER DEPOSITS IN NORTHWEST MEXICO." Diss., Tucson, Arizona : University of Arizona, 2005. http://etd.library.arizona.edu/etd/GetFileServlet?file=file:///data1/pdf/etd/azu%5Fetd%5F1085%5F1%5Fm.pdf&type=application/pdf.
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Dickinson, Jenni Michelle. "Jura-triassic magmatism and porphyry Au-Cu mineralization at the Pine Deposit, Toodoggone District, North-central British Columbia." Thesis, University of British Columbia, 2006. http://hdl.handle.net/2429/3959.
Full textAbstract:
The Pine, Fin, and Mex porphyry Au-Cu ± Mo systems are all located within a 10 km² area in the
Toodoggone district, along the eastern margin of the Stikine terrane in British Columbia. Multiple
episodes of porphyry-style mineralization are associated with these three magmatic centres. The Fin
monzogranite is the oldest dated pluton in the district, with a U-Pb zircon emplacement age of 217.8 ± 0.6
Ma. A cross-cutting main-stage quartz-pyrite-chalcopyrite ± molybdenite ± sphalerite vein gives an older
Re-Os molybdenite mineralization age of 221.0 ± 1.4 Ma. Hence the vein probably cross-cuts a slightly
older, undated magmatic phase. Lead isotope values for sulphide minerals from main-stage veins indicate
that magmatic-derived fluids interacted with country rocks and possibly other fluids.
The Pine quartz monzonite (U-Pb zircon emplacement age of 197.6 ± 0.5 Ma) intrudes, alters,
and locally mineralizes Toodoggone Formation Duncan Member andesite tuff (U-Pb zircon age of 200.9
± 0.4 Ma). High-grade (0.57 g/t Au and 0.15% Cu) mineralization occurs in main-stage quartz-magnetite
chalcopyrite-pyrite veins and disseminated throughout the potassic alteration zone in the Pine quartz
monzonite stock. Late-stage anhydrite-pyrite ± specular hematite ± chalcopyrite, quartz-pyrite ±
chalcopyrite, and pyrite ± chalcopyrite veins and related phyllic alteration cross-cut earlier veins.
Propylitic alteration occurs distal to the potassic core of Pine in the Fin monzogranite and Duncan
Member andesite. Limited fluid inclusion data, in combination with S and Pb isotope values for veins and
host rocks, suggest that the main-stage fluid was magmatic-derived and deposited metals at 430 to 550 °C
and depths of about 5.5 km. Late-stage fluids were also probably derived from the Pine quartz monzonite
but interacted with Takla Group country rock prior to metal deposition. Metals were deposited at
temperatures of 330 to 430 °C and depths of about 5.0 to 5.5 km.
The final mineralization phase of the Pine porphyry system is temporally constrained by the
emplacement of weakly mineralized syenite dykes (U-Pb zircon age of 193.8 ± 0.5 Ma). The final stage
of magmatism in the Pine-Fin-Mex area is defined by the emplacement of rhyolite dykes (U-Pb zircon
age of 193.6±0.4 Ma).
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Puig-Pichuante, R. M. "Molybdeunum mineralization with emphasis on porphyry systems genesis and exploration." Thesis, Rhodes University, 1986. http://hdl.handle.net/10962/d1006840.
Full textAbstract:
Mo became very important in the last century, because of its sophisticated properties and its use in the new technology of alloys . Porphyry systems (porphyry Cu-Mo and Mo) contribute a significant proportion (90 - 95 per cent) to the Mo world's production. This type of deposit is associated mainly with Phanerozoic orogenic belts. Above 87per cent of the world resources are in the American Circumpacific belts , both Andean and Cordilleran . Ore grade in porphyry Cu-Mo range from 0,005 to 0,04per cent Mo, whereas in porphyry Mo grades range from 0,08 to 0,75per cent Mo . These deposits are associated with a magmatism which shows an evolution from calcic in island arcs, to calc-alkaline in magmatic back arcs, with an increase of the Mo content in the same direction. Porphyry Mo deposits display several features in common with porphyry Cu deposits. hydrothermal Similarities include nature of host alteration patterns and distribution of rock intrusives, ore minerals. An interesting difference is found in the Re contents of the molybdenite mineral. This element is higher in the molybdenites of porphyry Cu, than in those of the porphyry Mo. The ore genesis process begins involves partial melting, within enriched zones of the upper mantle and magma differentation, liquid state thermogravitational diffusion, magma convection and boiling. These processes progressively concentrate Mo in the fluids, which are released at some stage, into sulphidic hydrothermal systems, under complex geologictectonic conditions involving fracturing, brecciation and hydrothermal alteration. Major concentrations of the ore mineral are always associated with potassic alteration, and with late magmatic-early hydrothermal stages (Chilean and Western North American porphyries). Geological mapping and a close understanding of alteration and mineralization patterns, and lithogeochemistry are important tools for the exploration of porphyry Mo deposits. Geochemical prospecting, using soils, vegetation and water as sampling media, and regional aeromagnetic, gravity surveys, aerial photography and remote sensing, are us.
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Piché, David. "Le problème des universaux dans l'Isagoge de Porphyre selon quelques commentateurs latins du XIIIe siècle (Pseudo-Robertus Anglicus, Jean le Page, Nicolas de Paris et Robert Kilwardby) : édition critique sélective, traduction française, analyses structurelle et formelle et étude historico-philosophique." Doctoral thesis, Université Laval, 2002. http://hdl.handle.net/20.500.11794/42828.
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Notre connaissance de l'histoire du problème des universaux, tel qu'il fut initialement formulé par Porphyre, souffre d'une importante lacune : nous ne savons strictement rien concernant le traitement que ce problème a reçu de la part de ceux qui faisaient profession de philosopher à l'Université de Paris entre 1230 et 1260. Notre thèse s'attaque à ce déficit de savoir en suivant une démarche heuristique qui se déploie en trois phases : premièrement, nous éditons, selon les règles de l'ecdotique, une partie substantielle du commentaire du Pseudo-Robertus Anglicus sur l'Isagoge de Porphyre et nous en offrons une traduction française; deuxièmement, nous sondons l'architectonique de ce texte et des écrits parallèles rédigés par des contemporains--nommément Jean le Page, Nicolas de Paris et Robert Kilwardby; troisièmement et finalement, par l'entremise d'une étude comparative qui met à profit ces documents inédits qui composent notre corpus, nous procédons à une étude historico-philosophique du commentaire isagogique du Pseudo-Robertus Anglicus.
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Fraunberg, Mikael von und zu. "Molecular genetics of variegate porphyria in Finland." Helsinki : University of Helsinki, 2003. http://ethesis.helsinki.fi/julkaisut/laa/kliin/vk/fraunberg/.
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Jones, Liza T. "Nitrogen dioxide sensing using porphyrin and porphyrin-calixarene hybrid LB films." Thesis, University of Sheffield, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.397502.
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Alemán, Elvin A. "PHOTOCHEMISTRY AND PHOTOPHYSICAL CHARACTERIZATION OF PORPHYRIN & N-CONFUSED PORPHYRIN DYADS: PORPHYRIN PHOTOPHYSICAL PROPERTIES AND ELECTRON AND ENERGY TRANSFER." University of Akron / OhioLINK, 2006. http://rave.ohiolink.edu/etdc/view?acc_num=akron1161633478.
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Lampadaridi, Anna. "La Vie de Porphyre de Gaza par Marc le Diacre (BHG³ 1570) : Édition critique, traduction, commentaire." Thesis, Paris 4, 2011. http://www.theses.fr/2011PA040140.
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La Vie de Porphyre de Gaza (BHG³ 1570) se présente comme un texte hagiographique de l’époque protobyzantine écrit par Marc le Diacre. Ce personnage se désigne lui-même comme le disciple du saint qui raconte la vie de son maître après sa mort en 420. Pourtant, à cause d’un emprunt à l’Histoire Philothée de Théodoret de Cyr, la Vie dans son état actuel est certainement postérieure à l’année 444 et ne peut pas provenir de la plume de Marc, qui n’est que le narrateur. Selon l’hypothèse des éditeurs Grégoire et Kugener, la Vie actuelle est le fruit du remaniement d’un texte plus ancien. Le texte nous offre un témoignage unique sur l’histoire du paganisme et du christianisme à Gaza à la fin du IVe et au début du Ve s. Ordonné évêque de Gaza en 395, Porphyre contribue activement à la christianisation de la ville, qui était alors majoritairement païenne. Le point culminant de son activité est la démolition du Marneion et la fondation sur ses débris de la « Grande Église » de Gaza. Cependant, outre les problèmes concernant l’identité de son auteur et sa datation, la Vie s’est trouvée dès l’époque de Tillemont au centre d’un grand débat concernant sa valeur historique, à cause des anachronismes qui ont été relevés. Dans le cadre de notre thèse, nous avons entrepris une nouvelle édition critique du texte, accompagnée d’une traduction française. La brève étude littéraire du texte est suivie par un commentaire historique guidé par le problème d’authenticité que pose la Vie. L’édition critique est précédée d’un examen de la tradition directe et indirecte du texte. Finalement, les notes de la traduction visent à faire ressortir sa valeur documentaireThe Life of Porphyry of Gaza (BHG³ 1570) is a hagiographical text of the protobyzantine period written by Mark the Deacon. He introduces himself as the saint’s loyal disciple, who narrates his master’s life after his death in 420. However, due to the plagiarism of Theodoret of Cyrrhus’s Philotheos History, the current form of the Vita dates certainly later than 444 and cannot have been written by Mark, who is just the narrator. According to the hypothesis of the editors Grégoire and Kugener, the current form of the Vita is the result of the revision of an older text. The text provides us with a unique account of the history of paganism and christianism in Gaza at the end of the 4th and the beginnings of the 5th century. Appointed bishop of Gaza in 395, Porphyry contributes actively to the christianisation of the city, which was largely pagan. The peak of his activity is the demolition of the Marneion and the erection of the “Great Church” of Gaza on the site of the former temple. However, in addition to the problems concerning its authorship and its datation, the Vita was found in the centre of a great debate concerning its historical value since the time of Tillemont. In the frame of our PhD thesis, we undertook a new critical edition, accompanied by a french translation. The brief literary study of the text is followed by a historical commentary guided by the problem of the Vita’s authenticity. The critical edition is preceded by an examination of the direct and the indirect text tradition. Finally, the notes of the translation aim to reveal its documentary value
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Huh, Min-Jun. "Le premier commentaire de Boèce à l’Isagogè de Porphyre : introduction, traduction et commentaire." Thesis, Paris 4, 2013. http://www.theses.fr/2013PA040145.
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Notre thèse en deux volumes vise à donner une traduction inédite du premier commentaire de Boèce à l’Isagogè de Porphyre à partir de l’édition critique de Samuel Brandt publiée en 1906. De fait, Boèce s’appuie sur la traduction latine de Marius Victorinus et non, comme le suggère le titre, sur le texte grec de Porphyre. Le premier volume contient une introduction générale articulée en quatre parties: examen critique des études secondaires; les sources matérielles du premier commentaire de Boèce à l’Isagogè; le traitement des questions de Porphyre sur les universaux; et l’Isagogè de Marius Victorinus et la tradition rhétorique latine. Les thèses que nous défendons sont les suivantes : le commentaire perdu de Porphyre sur les Catégories (A Gédalios) pourrait avoir été la source principale de ce traité logique de Boèce ; historiquement, les trois questions de Porphyre ont été apparentées à la réfutation porphyrienne de la position anti-aristotélicienne de Plotin ; et, contrairement à Victorinus qui considère l’Isagogè comme une introduction aux Topiques de Cicéron, Boèce la conçoit dans la perspective néoplatonicienne qui fait d’elle une introduction aux Catégories d’Aristote. Cette introduction est suivie de la traduction française accompagnée du texte latin de l’édition de Brandt. Notre commentaire à la traduction est développé dans le second volume qui contient également une traduction française inédite du commentaire d’Ammonius à l’Isagogè de Porphyre et une réfutation de la thèse soutenue par Brandt dans ses prolegomena de son édition critique à propos des parallèles textuels attestés dans les commentaires à l’Isagogè de Boèce et d’Ammonius (cf. appendices 1 et 2)Our thesis in two volumes aims to give an original French translation of Boethius’s first commentary on Porphyry’s Isagoge based on the critical edition published by Samuel Brandt in 1906. Actually, Boethius commentary deals with the Latin translation of Marius Victorinus and not, as the title seems to suggest, with the greek treatise of Porphyry. The first volume contains a general introduction divided into four parts : a critical studies of the secondary sources; the material sources of the Boethian first commentary on Isagoge; the Boethian analysis of Porphyry’s three questions about universals; and Marius Victorinus’ Isagoge and the Latin rhetorical tradition. The thesis we defend in the introduction can be summarized as follows : Porphyry’s lost commentary on Categories (Ad Gedalium) may have been the main source of the first Boethian commentary on Isagoge ; historically, the three questions on universals had been related to the Porphyrian refutation of anti-Aristotelian position of Plotinus ; and, unlike Victorinus which considers Isagoge as an introduction to Cicero’s Topica, Boethius adopts the Neoplatonic perspective which makes it an introduction to Aristotle’s Categories. This introduction is followed by the French translation accompanied by the latin text edited by Brandt. Our commentary on the Boethian treatise is developed in the second volume, which also contains an original French translation of Ammonius’ commentary on Porphyry’s Isagoge and a full refutation of the thesis supported by Brandt in his prolegomena to his critical edition about the textual parallels attested in the Boethian and Ammonian commentaries on Isagoge (cf. appendix 1 and 2)
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Du, Plessis Nelita. "Analysis of genetic variants in the 5' regulatory region of the ALAS1 gene in South African patients with variegate porphyria (VP) /." Thesis, Link to online version, 2007. http://hdl.handle.net/10019/420.
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Hori, Takaaki. "Studies on giant porphyrin wheels and on aggregation behavior of porphyrin family." 京都大学 (Kyoto University), 2010. http://hdl.handle.net/2433/120685.
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Steyn, Ilse. "Investigation of the possible influences of candidate modifier genes on the clinical expression of variegate porphyria (VP)." Thesis, Stellenbosch : Stellenbosch University, 2002. http://hdl.handle.net/10019.1/52896.
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Thesis (MSc)--University of Stellenbosch, 2002.ENGLISH ABSTRACT: Variegate porphyria (VP, MIM 176200) is a low penetrance autosomal dominant disorder that stems from mutations in the protoporphyrinogen oxidase (PPOX) gene. VP is found in most populations, but has a high prevalence in the South African Afrikaner population with most patients inheriting the same PPOX mutation (R59W) from a common ancestor. The clinical manifestations of the disease include acute neurovisceral attacks and/or cutaneous photosensitivity. Great variation in the clinical presentation of VP is observed; even in members of the same family that share a common genetic background and that have been exposed to similar environmental factors. Candidate genes that may have an influence on phenotypic variation due to the regulatory function in the haem biosynthetic pathway include the two deltaaminolevulinic acid synthase (ALAS) genes and the porphobilinogen deaminase (PBGD) gene. Sequence homology searches between different species indicated that the ALAS-1, ALAS-2 and PBGD genes are highly conserved, indicating that these genes have an important function to fulfill in the haem biosynthetic pathway. The study population of 25 R59W individuals were divided in four categories according to their clinical presentation. The distribution of clinical symptoms observed in this study corresponds with results from previous studies. Conformation sensitive gel electrophoresis (CSGE), conventional single stranded conformation polymorphism analysis (SSCP) and two buffer SSCP analysis were implemented to screen for possible sequence variants. The exons of all three genes as well as the adjacent intronic sequences were investigated. A total of six sequence variation sites were identified of which five had previously been described single nucleotide polymorphisms (ALAS-1: 4713 T>C; PBGD: -64 C>T, 3581 A>G, 6479 G>T, 7064 C>A)] and a novel 8bp deletion (PBGD: 4582_ 4589del). No sequence variant was identified in the ALAS-2 gene. The CSGE method proved to have the highest sensitivity (83%), identifying five of six sequence variant sites. The conventional SSCP method identified only three (50%) sequence variant sites, while the two buffer system detected two (33%) of the sequence variants. The 4713 T>C SNP in exon 4 of the ALAS-1 gene and the -64 C>T SNP in the PBGD gene were selected for further investigation due to their location in the respective genes. These sequence variants were typed in 50 patients and 50 control subjects matched for ethnic background. The relationship between variation at these loci and clinical features was investigated. No statistical significant association was observed for either of the 4713 T>C SNP (P= 0.717) or the -64 C>T SNP (P= 0.931). Genetic modifying factors make a variable contribution to the total clinical picture and are difficult to identify in small populations. Due to the fact that we only had a limited number of VP samples, association cannot be ruled out. This study does, however, provide insight into investigational approaches that should be undertaken in future research concerning the ALAS and PBGD genes. Further knowledge concerning the haem biosynthetic pathway could ultimately lead to the understanding and assessment of the clinical expression observed in individuals with VP.
AFRIKAANSE OPSOMMING: Variegate porfirie (VP, MIM 176200) is 'n lae penetrasie outosomaal dominante siekte wat veroorsaak word deur mutasies in die protoporfirienogeen oksidase (PPOX) geen. VP word gevind in die meeste populasies, maar het 'n hoë voorkoms in die Suid- Afrikaanse populasie waar meeste pasiente dieselfde PPOX mutasie (R59W) van 'n gemeenskaplike voorouer oorgeërf het. VP word gekenmerk deur akute neuroviserale aanvalle en/of fotosensitiewe vel. Groot variasie word egter waargeneem in die kliniese uitdrukking van VP, selfs in lede van dieselfde familie wat 'n gemeenskaplike genetiese agtergrond deel en wat blootgestel is aan dieselfde omgewingsfaktore. Kandidaat gene wat as gevolg van hulle regulatoriese funksie in die heem biosintetiese padweg 'n effek op die ekspressie van VP mag hê, sluit in die twee deltaaminolevuliniese suur sintase (ALAS) en die porfobilinogeen deaminase (PBGD) gene. Homologie ondersoeke van die ALAS-1, ALAS-2 en PBGD gene in verskillende spesies dui daarop dat die gene hoogs gekonserveerd is en dus gevolglik 'n belangrike funksie in die heem biosintetiese padweg vertolk. Die studie populasie van 25 R59W individue is verdeel in vier kategorieë op grond van hulle kliniese simptome. Die verspreiding van die kliniese simptome wat waargeneem is tydens hierdie studie stem ooreen met die resultate van vorige studies. Konformasie sensitiewe gel elektroforese (CSGE), konvensionele enkelstring konformasie polimorfisme analise (SSCP) en twee buffer SSCP analise is gebruik vir die identifisering van genetiese variasie. Die eksons van al drie gene, sowel as die aangrensende intron volgordes, is ondersoek. 'n Totaal van ses areas van genetiese variasie is geïdentifiseer, waarvan vyf reeds beskryfde polimorfismes is (ALAS-1: 4713 T>C; PBGD: -64 C>T, 3581 A>G, 6479 G>T, 7064 C>A) en 'n nuwe 8bp delesie (PBGD: 4582_ 4589del). Geen genetiese volgorde variasie is gevind in die ALAS-2 geen nie. Die CSGE metode het die hoogste sensitiwiteit getoon (83%) en het vyf van die ses volgorde variasies geïdentifiseer. Die konvensionele SSCP metode het slegs drie volgorde variasies geïdentifiseer (50%), terwyl die twee buffer deteksie-sisteem twee variasies geïdentifiseer (33%) het. Die 4713 T>C polimorfisme in ekson 4 van die ALAS-1 geen en die -64 C>T polimorfisme in die PBGD geen, is geselekteer vir verdere ondersoek as gevolg van hulle posisie in die respektiewe gene. Die volgorde variasies is getipeer in 50 R59W pasiënte sowel as in 'n kontrole groep van 50 individue met dieselfde etniese agtergrond. Die verband tussen die variasie by die lokusse en die kliniese kenmerke is ondersoek. Geen statisties beduidende assosiasie is waargeneem vir hetsy die 4713 T>C SNP (P= 0.717) of die -64 C>T SNP (P= 0.931). Genetiese modifiserende faktore word moeilik geïdentifiseer in klein populasies omdat hulle afsonderlike bydra tot die geheelbeeld van die kliniese simptome so varieerbaar is. 'n Relatiewe klein groep van VP pasiënte was tydens die studie beskikbaar en dus kan assosiasie nie uitgesluit word nie. Die studie verskaf egter insig in verband met toekomstige benaderings wat volg kan word in verdere ondersoeke van die ALAS en PBGD gene. Verdere kennis in verband met die heem biosihtetiese padweg kan uiteiHdelik lei tot die verduideliking en assesering van die kliHiese uitdrukking in vI=' individue.
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Herrick, Ariane L. "Studies of the pathogenesis and treatment of acute intermittent porphyria." Thesis, University of Aberdeen, 1989. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327839.
Full textAbstract:
The thesis examines the pathogenesis and treatment of acute intermittent porphyria (AIP), an inherited disorder of haem biosynthesis characterised biochemically by overproduction and increased excretion of porphyrin precursors, and clinically by neurovisceral crises which can be life-threatening. Both prevention and treatment of porphyric crises are considered. Acute attacks can be triggered by either endogenous or exogenous precipitants. A trial of hormonal suppression, using the luteinizing hormone releasing hormone analogue buserelin, in 7 patients suffering premenstrual attacks of AIP, suggested a trend towards clinical improvement on buserelin although response to treatment varied widely between patients. The relationship between endogenous steroids and disease activity in AIP was further examined by measuring urinary steroid metabolite excretion in patients with active, latent, and quiescent disease. In patients with active AIP the ratio of 5α to 5β urinary steroid metabolites was reduced, as was total steroid metabolite excretion. The finding of elevated plasma sex hormone-binding globulin concentrations in patients with active AIP is also reported. Drug porphyrinogenicity is discussed with reference to antidepressants and anticonvulsants. Preliminary anecdotal experience of the use of the haem derivative haem arginate in the treatment of 37 acute attacks of porphyria is described, and the first double-blind controlled trial of haem derivative treatment reported. This studied 21 attacks in 12 patients. While haem arginate invariably produced a marked fall in porphyrin precursor excretion, it did not significantly affect clinical outcome, although there was a trend in favour of haem treatment. In 7 attacks of AIP, haem arginate corrected the impaired hepatic mixed function oxygenase activity which is a recognised feature of AIP : antipyrine clearance was increased. The finding of raised blood lactate levels after glucose loading suggested that cytochrome deficiency affecting the terminal respiratory chain also occurs in AIP. It is postulated that the genetic, metabolic, endocrine and hepatic abnormalities of AIP may be inter-related through haem deficiency.