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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Photosynthesis and Respiration of Arceuthobium Tsugense

Miller, James Roger 01 January 1973 (has links)
Dark respiration rates of the aerial shoots of Arceuthobium tsugense, obtained by manometric and IRGA techniques, show production of C02to range between 155-300 µl CO2 g-1h-1 with evidence of seasonal variation. Experiments with 14C02 indicate that the aerial shoots are capable of some photosynthetic CO2 fixation, with 10-15% of the available 14C incorporated by the plant tissue in one hour.The portions of the o aerial shoots which are most active in C02 fixation are the young terminal regions. Biochemical characterization of the products of photosynthesis reveals that 80-90% of the incorporated 14C is ethanol soluble. Ten percent of the ethanol fraction is lipoidal in nature, the rest is H20 soluble. Ion exchange separation of the H20 soluble portion shows that 16-25% of the 14C activity is cationic, about 25% anionic, with the balance neutral. Aspartic acid, glutamic acid, and valine are present in the cationic fraction, with additional free amino acids indicated. IRGA experiments indicate an apparent photosynthetic CO2 fixation capacity of 80-90 percent of the ethanol fraction is lipoidal in nature, the rest is H20 soluble. Ion exchange separation of the H20 soluble portion shows that 16-25% of the 14C activity is cationic, about 25% anionic, with the balance neutral. Aspartic acid, glutamic acid, and valine are present in the cationic fraction, with additional free amino acids indicated. IRGA experiments indicate an apparent photosynthetic CO2 fixation capacity of 80-90 µl CO2 g-1 h-1, or 25-30% of the amount of C02 produced by respiration. The significance of these findings is discussed with respect to nutrition of the parasite.
12

Mistletoes and Thionins : as Selection Models in Natural Products Drug Discovery

Larsson, Sonny January 2007 (has links)
<p>The process of drug discovery from natural products starts with the selection of study object. In this project recent knowledge and methods are incorporated to investigate the process of such selection for pharmacognostic investigations. As the model and object of study mistletoes and their content of the small cytotoxic peptides thionins are chosen.</p><p>The thionins are compared in silico to other proposed plant innate defense peptides. Utilizing analysis of amino acid sequences and secondary structures, the thionins are shown to be one of eight distinct groups of cystein-rich plant polypeptides analysed. Common features of thionins are exploited in an investigation of isolation methods, where a simple acidic extraction is equally efficient to isolate thionins as the laborious methods hitherto used. </p><p>An effort to study the relationships of the order Santalales was done. To infer phylogenetic relationships from DNA sequences, we increased the taxon sampling for utilized genes and regions such as <i>rbcL</i>, <i>atpB</i> and ribosomal 18S and 26S rDNA sequences within the Santalales. Analysing these together with published sequences for other tricolpate taxa a position for Santalales as sister to caryophyllids and basal to asterids is implied. This indication is supported by chemical characters such as the presence of cyclopeptide alkaloids of a kind only known from Gentianales.</p><p>To validate the chemosystematic implications from thionin distribution extracts of mistletoes collected in Panama, Taiwan and Madagascar, and the relative <i>Osyris alba</i> (Santalaceae) collected in Spain, were screened with the established fluorescence microculture cytotoxicity assay using the thionin-sensitive human lymphoma cell-line U937GTB. Bioassay guided isolation concludes that the cytotoxic compounds in Loranthaceae may however constitute another group of peptides.</p><p>In conclusion this work shows that the incorporation of informatic techniques may aid prediction and decision making when planning pharmacognostic research.</p>
13

Mistletoes and Thionins : as Selection Models in Natural Products Drug Discovery

Larsson, Sonny January 2007 (has links)
The process of drug discovery from natural products starts with the selection of study object. In this project recent knowledge and methods are incorporated to investigate the process of such selection for pharmacognostic investigations. As the model and object of study mistletoes and their content of the small cytotoxic peptides thionins are chosen. The thionins are compared in silico to other proposed plant innate defense peptides. Utilizing analysis of amino acid sequences and secondary structures, the thionins are shown to be one of eight distinct groups of cystein-rich plant polypeptides analysed. Common features of thionins are exploited in an investigation of isolation methods, where a simple acidic extraction is equally efficient to isolate thionins as the laborious methods hitherto used. An effort to study the relationships of the order Santalales was done. To infer phylogenetic relationships from DNA sequences, we increased the taxon sampling for utilized genes and regions such as rbcL, atpB and ribosomal 18S and 26S rDNA sequences within the Santalales. Analysing these together with published sequences for other tricolpate taxa a position for Santalales as sister to caryophyllids and basal to asterids is implied. This indication is supported by chemical characters such as the presence of cyclopeptide alkaloids of a kind only known from Gentianales. To validate the chemosystematic implications from thionin distribution extracts of mistletoes collected in Panama, Taiwan and Madagascar, and the relative Osyris alba (Santalaceae) collected in Spain, were screened with the established fluorescence microculture cytotoxicity assay using the thionin-sensitive human lymphoma cell-line U937GTB. Bioassay guided isolation concludes that the cytotoxic compounds in Loranthaceae may however constitute another group of peptides. In conclusion this work shows that the incorporation of informatic techniques may aid prediction and decision making when planning pharmacognostic research.
14

Ecology of box mistletoe Amyema miquelii dispersal in pink gum Eucalyptus fasciculosa woodlands.

Ward, Matthew J. January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The proliferation of box mistletoe Amyema miquelii in eucalypt woodlands of south-eastern Australia may have resulted from the suppression of canopy fires, a reduction in herbivory by possums, and through environmental change, an improvement in conditions for mistletoe dispersal and establishment. In the Mount Lofty Ranges (MLR), South Australia, box mistletoe is often seen in high numbers in pink gum Eucalyptus fasciculosa woodlands. The following dissertation investigated box mistletoe dispersal and establishment by Mistletoebirds Dicaeum hirundinaceum in a pink gum woodland. The broad aims of the study were to advance our theoretical knowledge of mistletoe dispersal ecology, to understand why pink gum woodlands are more susceptible to mistletoe infection, and to increase the amount of ecological information available to land managers. A survey of box mistletoe and its Eucalyptus hosts in reserves of the MLR region revealed that almost a third of all pink gums were infected with box mistletoe. Individual pink gums with less foliage cover surrounding their canopy were more likely to host box mistletoe, suggesting canopy access for Mistletoebirds may influence the susceptibility of pink gums to mistletoe infection. Woodland type was more influential than fragmentation and edge effects in determining mistletoe presence, indicating a variation in host specificity across Eucalyptus species. The results of this survey indicated that further examination was required on Mistletoebird behaviour and mistletoe establishment success. Two aspects of Mistletoe bird ecology were examined: the influence of their movement patterns on the spatial dynamics of mistletoe dispersal, and their foraging behaviour. Mistletoebirds had home ranges of around 20 ha, and used small core areas (1 ha) of high mistletoe infestation more frequently than areas with lower mistletoe abundance. Modelling of mistletoe seed shadows indicated that the majority of mistletoe seeds (approx. 70%) would be deposited within 100 m of a parent plant. Consistent with this, seed rain modelling showed that mistletoe seed rain was aggregated, with birds dispersing large amounts of seed (> 66 000/ ha) in areas with higher mistletoe infestation levels. This indicated that the movements of mistletoe dispersers promote mistletoe aggregation not only at the scale of an individual tree, but also at a landscape scale. From a management perspective, the results indicated that the removal of mistletoes from single trees may have only short-term results, as reinfection from neighbouring host trees is likely. The attractiveness of pink gums to Mistletoebirds was a function of tree size, mistletoe crop size and tree access. Mistletoebirds preferred to forage in taller trees with a larger mistletoe crop size and which had greater canopy access, and Mistletoebirds most often alighted on dead pink gum when visiting a tree. The results support the notion that woodland dieback may improve conditions for mistletoe dispersal by allowing favourable habitat for Mistletoebirds, by increasing canopy access and by providing more perch sites. Dieback will also reduce mistletoe establishment, however, through a loss of suitable live host branches. The high frequency of box mistletoe infection in pink gum woodlands could also be explained by differences in establishment of box mistletoe between eucalypt species. A mistletoe establishment experiment demonstrated that establishment was significantly higher on pink gums than on E. porosa and E. camaldulensis, and that mistletoes established on pink gums were larger and had a greater number of leaves. The differences probably lay in underlying differences in host physical and chemical defences, and subsequent relative success of mistletoes to establish a functional haustorium. The dispersal syndrome of box mistletoe as described in this study is suitable and perhaps facilitated in the contemporary fragmented environment in a number of ways. These include an ability to concentrate their feeding and breeding activities in small areas of remnant vegetation, greater manoeuvrability between trees isolated by clearing, and easier access to the canopies and perch sites of individual trees in deteriorated woodlands. Priority research stemming from this study should include studies into the underlying causes of pink gum dieback, an experiment to test whether canopy die back directly results in more frequent visitation by Mistletoebirds, an examination of Mistletoebird movements in areas with low mistletoe abundance, and continued monitoring of mistletoe abundance and tree condition as established in this dissertation. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1285516 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007
15

Ecology of box mistletoe Amyema miquelii dispersal in pink gum Eucalyptus fasciculosa woodlands.

Ward, Matthew J. January 2007 (has links)
Title page, table of contents and abstract only. The complete thesis in print form is available from the University of Adelaide Library. / The proliferation of box mistletoe Amyema miquelii in eucalypt woodlands of south-eastern Australia may have resulted from the suppression of canopy fires, a reduction in herbivory by possums, and through environmental change, an improvement in conditions for mistletoe dispersal and establishment. In the Mount Lofty Ranges (MLR), South Australia, box mistletoe is often seen in high numbers in pink gum Eucalyptus fasciculosa woodlands. The following dissertation investigated box mistletoe dispersal and establishment by Mistletoebirds Dicaeum hirundinaceum in a pink gum woodland. The broad aims of the study were to advance our theoretical knowledge of mistletoe dispersal ecology, to understand why pink gum woodlands are more susceptible to mistletoe infection, and to increase the amount of ecological information available to land managers. A survey of box mistletoe and its Eucalyptus hosts in reserves of the MLR region revealed that almost a third of all pink gums were infected with box mistletoe. Individual pink gums with less foliage cover surrounding their canopy were more likely to host box mistletoe, suggesting canopy access for Mistletoebirds may influence the susceptibility of pink gums to mistletoe infection. Woodland type was more influential than fragmentation and edge effects in determining mistletoe presence, indicating a variation in host specificity across Eucalyptus species. The results of this survey indicated that further examination was required on Mistletoebird behaviour and mistletoe establishment success. Two aspects of Mistletoe bird ecology were examined: the influence of their movement patterns on the spatial dynamics of mistletoe dispersal, and their foraging behaviour. Mistletoebirds had home ranges of around 20 ha, and used small core areas (1 ha) of high mistletoe infestation more frequently than areas with lower mistletoe abundance. Modelling of mistletoe seed shadows indicated that the majority of mistletoe seeds (approx. 70%) would be deposited within 100 m of a parent plant. Consistent with this, seed rain modelling showed that mistletoe seed rain was aggregated, with birds dispersing large amounts of seed (> 66 000/ ha) in areas with higher mistletoe infestation levels. This indicated that the movements of mistletoe dispersers promote mistletoe aggregation not only at the scale of an individual tree, but also at a landscape scale. From a management perspective, the results indicated that the removal of mistletoes from single trees may have only short-term results, as reinfection from neighbouring host trees is likely. The attractiveness of pink gums to Mistletoebirds was a function of tree size, mistletoe crop size and tree access. Mistletoebirds preferred to forage in taller trees with a larger mistletoe crop size and which had greater canopy access, and Mistletoebirds most often alighted on dead pink gum when visiting a tree. The results support the notion that woodland dieback may improve conditions for mistletoe dispersal by allowing favourable habitat for Mistletoebirds, by increasing canopy access and by providing more perch sites. Dieback will also reduce mistletoe establishment, however, through a loss of suitable live host branches. The high frequency of box mistletoe infection in pink gum woodlands could also be explained by differences in establishment of box mistletoe between eucalypt species. A mistletoe establishment experiment demonstrated that establishment was significantly higher on pink gums than on E. porosa and E. camaldulensis, and that mistletoes established on pink gums were larger and had a greater number of leaves. The differences probably lay in underlying differences in host physical and chemical defences, and subsequent relative success of mistletoes to establish a functional haustorium. The dispersal syndrome of box mistletoe as described in this study is suitable and perhaps facilitated in the contemporary fragmented environment in a number of ways. These include an ability to concentrate their feeding and breeding activities in small areas of remnant vegetation, greater manoeuvrability between trees isolated by clearing, and easier access to the canopies and perch sites of individual trees in deteriorated woodlands. Priority research stemming from this study should include studies into the underlying causes of pink gum dieback, an experiment to test whether canopy die back directly results in more frequent visitation by Mistletoebirds, an examination of Mistletoebird movements in areas with low mistletoe abundance, and continued monitoring of mistletoe abundance and tree condition as established in this dissertation. / http://proxy.library.adelaide.edu.au/login?url= http://library.adelaide.edu.au/cgi-bin/Pwebrecon.cgi?BBID=1285516 / Thesis (Ph.D.) -- University of Adelaide, School of Earth and Environmental Sciences, 2007
16

Mistletoes and thionins : as selection models in natural products drug discovery /

Larsson, Sonny, January 2007 (has links)
Diss. (sammanfattning) Uppsala : Uppsala universitet, 2007. / Härtill 5 uppsatser.
17

Uso de viscum album no ponto de acupuntura VG14 como terapia adjuvante à mastectomia radical em cadelas com neoplasias mamárias /

Figueiredo, Renata Nogueira. January 2014 (has links)
Resumo:A acupuntura é considerada como modalidade adjuvante de tratamento, pois melhora a qualidade de vida dos pacientes oncológicos, além de controlar estas alterações metabólicas. Adjutoriamente, o extrato de Viscum album utilizado na medicina antroposófica pode ser utilizado por causar a apoptose e citotoxicidade de células tumorais e, por isso, vem sendo amplamente utilizado. Observa-se aumento desses efeitos quando aplicado no ponto Vaso Governador 14 (VG14), considerado um dos pontos da imunidade. Durante décadas foram utilizadas inúmeras terapias para combater o câncer, sendo que a cirurgia, ainda, é a principal forma de tratamento, cujos protocolos são indicados de acordo com o tipo e local de ocorrência do mesmo. Terapias adjuvantes, também, são praticadas como a quimioterapia que emprega agentes citotóxicos, mas que produzem efeitos colaterais e adversos. Concluise que o tratamento adjuvante fez com que as cadelas apresentassem menores valores de globulinas, cálcio e FA, podendo auxiliar na prevenção do desenvolvimento de síndromes paraneoplásicas. Porém, novas pesquisas devem ser realizadas para avaliar com mais precisão os efeitos benéficos do uso dessas terapias complementares, conforme apresente este capítulo / Abstract:Acupuncture should be seen as an adjuvant treatment modality, because it improves the quality of life of patients with cancer, in addition to controlling these metabolic changes. Concomitantly, Viscum album extract used in anthroposophical medicine can be used to cause cytotoxicity and apoptosis of tumor cells and therefore has been widely applied. The data showed an increase of these effects when applied at point Governor Vessel. (VG14), one of the immunity points. For decades numerous therapies have been used to combat cancer, wherein the surgery still is the primary form of treatment protocols which are set according to the type and place of occurrence thereof. Other therapies are also applied as chemotherapy employing cytotoxic agents, but they produce side effects and adverse effects. We conclude that adjuvant therapy made the bitches presented lower values of globulins, calcium and FA to assist in preventing the development of paraneoplastic syndromes. However, further research should be conducted to more accurately assess the beneficial effects of using these complementary therapies, as this chapter shows / Orientador:Alexandre Lima de Andrade / Banca:Flávia Rezende Eugênio / Banca:Talita Floering Brêda Souza / Mestre
18

Uso de viscum album no ponto de acupuntura VG14 como terapia adjuvante à mastectomia radical em cadelas com neoplasias mamárias

Figueiredo, Renata Nogueira [UNESP] 19 August 2014 (has links) (PDF)
Made available in DSpace on 2015-10-06T13:03:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2014-08-19. Added 1 bitstream(s) on 2015-10-06T13:19:01Z : No. of bitstreams: 1 000849244.pdf: 624171 bytes, checksum: 87b755a945d322c151256c67ed4aabbe (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Acupuncture should be seen as an adjuvant treatment modality, because it improves the quality of life of patients with cancer, in addition to controlling these metabolic changes. Concomitantly, Viscum album extract used in anthroposophical medicine can be used to cause cytotoxicity and apoptosis of tumor cells and therefore has been widely applied. The data showed an increase of these effects when applied at point Governor Vessel. (VG14), one of the immunity points. For decades numerous therapies have been used to combat cancer, wherein the surgery still is the primary form of treatment protocols which are set according to the type and place of occurrence thereof. Other therapies are also applied as chemotherapy employing cytotoxic agents, but they produce side effects and adverse effects. We conclude that adjuvant therapy made the bitches presented lower values of globulins, calcium and FA to assist in preventing the development of paraneoplastic syndromes. However, further research should be conducted to more accurately assess the beneficial effects of using these complementary therapies, as this chapter shows
19

Componentes quantitativos e qualitativos da dispersão de sementes de Struthanthus flexicaulis (Loranthaceae) em uma área de campo rupestre do sudeste brasileiro /

Guerra, Tadeu José de Abreu. January 2005 (has links)
Orientador: Marco Aurélio Pizo / Banca: Mauro Galetti / Banca: Wesley Rodrigues Silva / Resumo: A investigação das interações entre plantas e seus agentes dispersores têm implicações para a compreensão da diversidade biológica e sua conservação, e é um importante tema da ecologia evolutiva. Este estudo teve como objetivo investigar os componentes quantitativos e qualitativos na dispersão de sementes de Struthanthus flexicaulis (Loranthaceae), uma erva-de-passarinho dióica, hemiparasita generalista e de ampla distribuição no cerrado do Brasil central. O estudo foi realizado entre janeiro de 2004 e abril de 2005 em um afloramento rochoso na Serra do Cipó, Minas Gerais. Foram realizadas observações sobre a fenologia dos indivíduos femininos, observações focais para a avaliação dos parâmetros comportamentais dos dispersores, censos para avaliação da abundância relativa, sazonalidade e parâmetros comportamentais dos dispersores, observação direta e amostragem por procura ativa para avaliar a deposição das sementes de S. flexicaulis. Observou-se uma variação individual em S. flexicaulis com relação à duração do período e quantidade de produção de flores e frutos. A população estudada, no entanto, apresentou reprodução contínua ao longo do ano, porém de baixa intensidade na maioria dos indivíduos. Struthanthus flexicaulis teve seus frutos consumidos por um número bastante restrito de frugívoros: Elaenia cristata e Elaenia obscura (Tyrannidae), Mimus saturninus (Mimidae) e Schistochlamys ruficapillus (Thraupidae). No entanto, E. cristata foi o visitante mais freqüente e abundante ao longo do ano, responsável por mais de 96% das sementes dispersadas. Na área de estudo E. cristata apresentou uma dieta predominantemente frugívora, complementada pelo consumo de artrópodes... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Quantity and quality components of seed dispersal in Struthanthus flexicaulis (Loranthaceae) in a rupestrian field in southeastern Brazil. The investigation of interactions between plants and their seed dispersers has implications for the understanding of the biological diversity, its conservation and is an important issue in evolutionary ecology. The goal of this study is to investigate the components of quality and quantity in the seed dispersal of Struthanthus flexicaulis (Loranthaceae), a generalist dioceous mistletoe with wide distribution in central Brazil. The study was conducted between January 2004 and April 2005 in a rocky outcrop in Serra do Cipó, Minas Gerais, southeastern Brazil. I conducted observations on female plant reproductive phenology, focal observations on fruiting plants to record behavioral parameters of seed dispersers, censuses to record the relative abundance, seasonality and behavioral parameters of seed dispersers, a direct observations and search on random established plots to evaluate seed deposition. Individual variation in the duration and quantity of flower and fruit production was detected. At the population level, reproduction was continuous, but in low intensity for most of the individuals. The fruits of S. flexicaulis were consumed by a small set of avian frugivores: Elaenia cristata and Elaenia obscura (Tyrannidae), Mimus saturninus (Mimidae) and Schistochlamys ruficapillus (Thraupidae), but E. cristata was the most frequent and abundant visitor throughout the year, responsible for more than 96% of the dispersed seeds. In the study site this bird was highly frugivorous, but also consuming a small proportion of arthropods... (Complete abstract, click electronic address below) / Mestre
20

The effect of Viscum album 2CH, 200CH and 1M on the growth rate of germinating Zea mays seeds

Forsyth, Stuart Wake 31 July 2008 (has links)
Prof. D. Mycock Dr. E. Solomon

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