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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.
1

Studies on the Dasyaceae and the Lophothalieae (Rhodomelaceae) of the Rhodophyta

Parsons, Murray Jury January 1971 (has links)
286 leaves : 37 ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Botany, 1972
2

Studies on the Dasyaceae and the Lophothalieae (Rhodomelaceae) of the Rhodophyta.

Parsons, Murray Jury. January 1971 (has links) (PDF)
Thesis (Ph.D.) -- University of Adelaide, Dept. of Botany, 1972.
3

A psbA phylogeny for selected rhodophyceae /

Hunt, Jannine M. January 2006 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2006. / Includes bibliographical references (Leaves: 13-15)
4

Reproductive seasonality of Hypnea charoides (rhodophyta) and algal recruitment in Ping Chau, N.T., Hong Kong SAR, China.

January 2002 (has links)
Kong Sau Lai. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 209-225). / Abstracts in English and Chinese. / Acknowledgements --- p.ii / Abstract --- p.iii / Contents --- p.vii / List of Tables --- p.xi / List of Figures --- p.xxiv / Chapter Chapter 1: --- General Introduction / Chapter 1.1 --- Introduction --- p.1 / Chapter 1.2 --- Study Site --- p.4 / Chapter 1.3 --- Study Material --- p.5 / Chapter 1.4 --- General Objectives --- p.6 / Chapter 1.5 --- Organization of the Thesis --- p.6 / Chapter Chapter 2: --- Seasonal Occurrence and Reproduction of Hypnea charoides in Ping Chau / Chapter 2.1 --- Introduction --- p.10 / Chapter 2.2 --- Materials and Methods --- p.12 / Chapter 2.2.1 --- Study sites --- p.12 / Chapter 2.2.2 --- Populations of Hypnea charoides --- p.13 / Chapter 2.2.3 --- Measurement of plant length --- p.14 / Chapter 2.2.4 --- Examination of reproductive structures --- p.14 / Chapter 2.2.5 --- Environmental parameters --- p.15 / Chapter 2.2.6 --- Statistical analysis --- p.15 / Chapter 2.3 --- Results --- p.16 / Chapter 2.3.1 --- Seasonal occurrence and growth of Hypnea charoides --- p.16 / Chapter 2.3.1.1 --- A Ma Wan populations --- p.16 / Chapter 2.3.1.2 --- Lung Lok Shui populations --- p.16 / Chapter 2.3.2 --- Reproductive seasonality --- p.17 / Chapter 2.3.2.1 --- A Ma Wan populations --- p.17 / Chapter 2.3.2.2 --- Lung Lok Shui populations --- p.19 / Chapter 2.3.3 --- Other observations --- p.19 / Chapter 2.3.4 --- Environmental parameters --- p.20 / Chapter 2.3.4.1 --- Photoperiod --- p.20 / Chapter 2.3.4.2 --- Seawater temperature --- p.20 / Chapter 2.3.4.3 --- Nutrient concentrations --- p.20 / Chapter 2.3.5 --- Statistical analysis --- p.21 / Chapter 2.3.5.1 --- A Ma Wan populations --- p.21 / Chapter 2.3.5.2 --- Lung Lok Shui populations --- p.22 / Chapter 2.4 --- Discussion --- p.23 / Chapter 2.4.1 --- Seasonal occurrence and growth of Hypnea charoides --- p.23 / Chapter 2.4.2 --- Reproductive seasonality --- p.27 / Chapter 2.4.3 --- Occurrence of cystocarps and tetrasporangia on the same thallus in Hypnea charoides --- p.34 / Chapter Chapter 3: --- Algal Recruitment on Artificial Clearings / Chapter 3.1 --- Introduction --- p.50 / Chapter 3.2 --- Materials and Methods --- p.52 / Chapter 3.2.1 --- Study site --- p.52 / Chapter 3.2.2 --- Clearing experiment --- p.53 / Chapter 3.2.3 --- Investigation on the clearing and control plots --- p.53 / Chapter 3.2.3.1 --- Species composition --- p.53 / Chapter 3.2.3.2 --- Percentage cover --- p.54 / Chapter 3.2.3.3 --- Species richness --- p.54 / Chapter 3.2.3.4 --- Species diversity --- p.55 / Chapter 3.2.4 --- Statistical analyses --- p.55 / Chapter 3.3 --- Results --- p.56 / Chapter 3.3.1 --- Species composition --- p.57 / Chapter 3.3.2 --- Percentage cover --- p.58 / Chapter 3.3.3 --- Species richness --- p.61 / Chapter 3.3.4 --- Species diversity --- p.65 / Chapter 3.4 --- Discussion --- p.69 / Chapter 3.4.1 --- Species composition and percentage cover --- p.70 / Chapter 3.4.2 --- Implications on algal succession --- p.76 / Chapter 3.4.3 --- Implications for Hypnea charoides --- p.79 / Chapter 3.4.4 --- Species richness and diversity --- p.82 / Chapter Chapter 4: --- Colonization of Early Algal Assemblages on Artificial Substrata / Chapter 4.1 --- Introduction --- p.121 / Chapter 4.2 --- Materials and Methods --- p.123 / Chapter 4.2.1 --- Study sites --- p.123 / Chapter 4.2.2 --- Experimental design --- p.124 / Chapter 4.2.3 --- Investigation for optimal sampling --- p.125 / Chapter 4.2.4 --- Examination of tiles / Chapter 4.2.4.1 --- Species composition --- p.127 / Chapter 4.2.4.2 --- Species richness --- p.127 / Chapter 4.2.4.3 --- Mean density --- p.127 / Chapter 4.2.4.4 --- Percentage cover of encrusting coralline algae --- p.128 / Chapter 4.2.4.5 --- Species diversity --- p.128 / Chapter 4.2.5 --- Statistical analyses --- p.128 / Chapter 4.3 --- Results --- p.129 / Chapter 4.3.1 --- Species composition --- p.130 / Chapter 4.3.2 --- A Ma Wan tiles --- p.130 / Chapter 4.3.2.1 --- Species richness --- p.130 / Chapter 4.3.2.2 --- Algal density --- p.131 / Chapter 4.3.2.3 --- Percentage cover of encrusting coralline algae --- p.133 / Chapter 4.3.2.4 --- Species diversity --- p.134 / Chapter 4.3.3 --- Lung Lok Shui tiles at -2 to -3 m CD - Biweekly-retrieved tiles --- p.135 / Chapter 4.3.3.1 --- Species richness --- p.135 / Chapter 4.3.3.2 --- Algal density --- p.136 / Chapter 4.3.3.3 --- Percentage cover of encrusting coralline algae --- p.136 / Chapter 4.3.3.4 --- Species diversity --- p.136 / Chapter 4.3.4 --- Lung Lok Shui tiles at 一2 to -3 m CD - Monthly-retrieved tiles --- p.137 / Chapter 4.3.5 --- Lung Lok Shui tiles at -1 m CD --- p.137 / Chapter 4.3.6 --- Permanently-placed tiles in A Ma Wan and Lung Lok Shui --- p.138 / Chapter 4.3.7 --- Presence of grazers and other organisms --- p.139 / Chapter 4.4 --- Discussion --- p.140 / Chapter Chapter 5: --- Seasonal Availability of Algal Propagules at Different Water Depths / Chapter 5.1 --- Introduction --- p.170 / Chapter 5.2 --- Materials and Methods --- p.171 / Chapter 5.2.1 --- Study sites and sample collection --- p.171 / Chapter 5.2.2 --- Experimental design --- p.173 / Chapter 5.2.3 --- Examination of tiles and statistical analyses --- p.174 / Chapter 5.3 --- Results --- p.174 / Chapter 5.3.1 --- Species composition --- p.174 / Chapter 5.3.2 --- Availability of algal propagules in A Ma Wan --- p.175 / Chapter 5.3.2.1 --- Species richness --- p.175 / Chapter 5.3.2.2 --- Frequency --- p.176 / Chapter 5.3.2.3 --- Species diversity --- p.177 / Chapter 5.3.3 --- Availability of algal propagules in Lung Lok Shui --- p.178 / Chapter 5.3.3.1 --- Species richness --- p.178 / Chapter 5.3.3.2 --- Frequency --- p.178 / Chapter 5.3.3.3 --- Species diversity --- p.179 / Chapter 5.3.4 --- Comparisons between A Ma Wan and Lung Lok Shui --- p.180 / Chapter 5.3.5 --- Physical parameters --- p.180 / Chapter 5.3.6 --- Correlation --- p.181 / Chapter 5.3.7 --- Other recruits - --- p.182 / Chapter 5.4 --- Discussion --- p.182 / Chapter Chapter 6: --- General Discussion --- p.197 / References --- p.205 / Appendix A --- p.222 / Appendix B --- p.270 / Appendix C --- p.278
5

An approach toward the total synthesis of prefuroplocamioid /

Majkut, Yvette. January 2005 (has links)
Thesis (M.Sc.)--York University, 2005. Graduate Programme in Chemistry. / Typescript. Includes bibliographical references (leaves 115-121). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url%5Fver=Z39.88-2004&res%5Fdat=xri:pqdiss &rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR11848
6

Studies on the biology of the economic marine red alga Gelidium pristoides (Turner) Kuetzing (Gelidiales : Rhodophyta)

Carter, Alan Robert January 1987 (has links)
Various aspects of the biology of the intertidal agarophyte, Gelidium pristoides, were investigated, with the aim of providing information that would assist in formulating a management policy for this economic seaweed resource. G.pristoides occurs as tufts comprising as many as 40 individual plants, representing all three conspicuous life history stages, that are linked by the intertwining of their basal creeping axes. Individual plants consist of a system of branched creeping axes, which is largely responsible for colonizing surrounding substrata, from which one or more erect flattened fronds arise. These erect fronds may reach a height of 15 cm, and are irregularly bipinnately branched. Internal vegetative anatomy is generally typical of the genus. Morphological variation in mature plants is limited to increased plant height and branch density during the summer season. A dorso-ventrally flattened creeping habit was seen during early recruitment on flat rock surfaces and limpet shells within grazer exclusion plots, which developed into typical erect plants. Although there is a close taxonomic affinity between G.pristoides and the low-growing Gelidium turf, which occurs on wave-cut platforms in the eastern Cape (both produce bispores), the turf appears to represent a genetically divergent ecotype of the typical G.pristoides habit. In the light of present observations, it is suggested that the recent inclusion of G.pristoides in the new Onikusa genus should be questioned. Reproduction in G.pristoides is typical of the genus, except for the production of bispores, instead of tetraspores, in the sporophyte generation. The smaller nuclei in the binucleate bispores, in comparison to carpospores, suggested they are the product of normal meiosis (meiospores). This was confi rmed by chromosome counts of germl i ngs deri ved from bispores (n = 13-17) and carpospores (2n = 28-33). Throughout the geographical range of the seaweed, the bisporophyte generation is dominant over the combined male and female gametophyte generati on by a ratio of about 3 : 1. This imbalance may be due to bispores. G.pristoides a greater germination success of carpospores over plants are fertile throughout the year, while at Port Alfred there is no apparent seasonality in spore release. Growth of carpospore and bispore germlings is similar under various temperature treatments in culture. Optimum temperatures for growth were from 15-23°C, which corresponds with the sea temperatures experienced within the geographical range of the species . At Port Alfred, growth (linear frond elongation) and standing crop levels were maximal during summer . Ory weight levels were significantly inversely related to both growth and ash levels. Agar contents (% of dry weight) were generally greater in summer (48% ) than in winter (30%), and were inversely correlated with thallus nitrogen levels. Agar contents of distal plant halves were higher (8-15%) than in proximal halves. Regrowth of G.pristoides to original biomass or standing crop levels after harvesting, is similar for plucking and shearing at different times of the year. Regrowth is more rapid after spring and summer harvests (2-3 months) than after winter harvests (4-5 months). During the summer season, harvesting at monthly intervals showed significantly greater total yields, and production rates (e.g . 3.13 g. dry wt. / m2 / day for plucking) than under 3-monthly intervals (1.42 g. dry wt. / m2 / day for plucking). In contrast, average yields per harvest were Significantly greater when recovery period was longer (e.g. 3 months). Quadrats that were completely denuded failed to recover after a year, while regrowth was also retarded with increased elevation on the shore. Agar contents did not differ Significantly between plucked (38%) and sheared (42%) plant material. G.pristoides is distributed from about 0 . 2-0.75 m above MLWS, with a reduction in stature and frequency corresponding to increased elevation on the shore. Frond elongation rates, germling survival and recruitment within grazer-exclusion plots, is retarded with increased elevation level. Plants transplanted above the normal vertical range of the seaweed became severely bleached and died, while plants transplanted below the normal range of the seaweed (sub littoral fringe) senesced due to overgrowth by the epiphytic encrusting coralline, Polyporolithon patena (Hook . et Harv . ) Mason . G.pristoides recrui t ment in the sublittoral fri nge was enhanced with the exclusion of grazers . However, successful recruits were displaced due to smothering by articulated corallines (e.g. Corallina sp. and Jania sp. ) . G.pristoides is largely restricted to cracks and crevices in the rock, and also occurs on a large proportion of the available shells of the limpet Patella oculus Born., and to a lesser extent, shells of the barnacle Tetraclita serrata. G.pristoides recruitment was significantly enhanced by the exclusion of grazers (using toxic antifouling paint barriers). G.pristoides recruitment within the exclusion plots was significantly greater on artificially attached limpet shells (almost 100% cover) than on rock surfaces (20-30% cover), which occurred largely within cracks and crevies in the rocky substratum. ly attached to limpet G.pristoides plants are significantly more strongand barnacle shells than to rock and epilithic encrusting corallines (Lithothamnion sp.). Removal of G.pristoides from limpet shells revealed pits of a uniform size in the surface of the shells, into which the rhizoidal attachment organs of the seaweed penetrate. It is concluded that the horizontal distribution of G.pristoides is largely controlled by grazers (and "escapes" from grazing) and resistance to dislodgement by wave action. Based on present results, and considering some of the socio-economic factors associated with the Gelidium industry in South Africa, suggestions are made concerning the management and long-term maintenance of G.pristoides resources in the eastern Cape.
7

A structural investigation of the sulphated polysaccharide pachymenia carnos (J. Ag.) J. Ag.

Farrant, Annette J January 1972 (has links)
The highly sulphated, methylated polysaccharide isolated from Pachymenia Carnosa, a red seaweed, was shown to contain D- galactose, 2-o (underscore) methyl-D- galactose, 6-o (underscore) -methyl- D- galactose and 4-o (underscore)-methylgalactose. The polysaccharide was desulphated with methanolic hydrogen chloride. Methylation of the desulphated polysaccharide revealed that it was composed entirely of (1→73) and (1→4) links in approximately equal amounts. Treatment of the polysaccharide with alkali showed that the majority of the ester sulphate groups were alkali-stable. Partial hydrolysis and acetolysis studies indicated that the polysaccharide was extremely complex, and contained alternate (1→3) and β (1→4) glycosidic linkages. There is evidence for the presence of D-galactose-6-sulphate.
8

A structural investigation of the sulphated polysaccharide from Aeodes ulvoidea Schmitz

Allsobrook, Anthony John Robert January 1973 (has links)
Aeodes ulvoidea, a red seaweed of the Grateloupiaceae, yielded a highly sulphated polysaccharide which was shown to contain D- and L-galactose, 4-0-methy-L-galactose, 2-0-methyl - D- and L-galactose and 6-0-methyl-D-galactose, together with chromatographic traces of xylose and mannose. The sulphate was not labile to alkali, but it was largely removed with methanolic hydrogen chloride. Periodate oxidation of the polysaccharide, methylation of the de sulphated polysaccharide, and investigation of fifteen oligosaccharides from partial hydrolysis and acetolysis studies of the polysaccharide, indicate that (a) the polysaccharide is composed of a backbone of D-galactose residues which are 1,3- and 1,4-linked (b) at least some regions of alternating structure do occur (c) the 2-0-methylgalactose is linked through the 4-position (d) the 4-0-methyl-L-galactose is present as single unit side chains glycosidically linked to the galactose backbone at position 6, and (e) most of the 6-0-methyl-D-galactose is linked to the 4-position of 2-0-methyl-D-galactose.
9

Studies on the biology of the economic marine red alga Gelidium pristoides (Turner) Kuetzing (Gelidiales : Rhodophyta)

Carter, Alan Robert January 1987 (has links)
Various aspects of the biology of the intertidal agarophyte, Gelidium pristoides, were investigated, with the aim of providing information that would assist in formulating a management policy for this economic seaweed resource. G.pristoides occurs as tufts comprising as many as 40 individual plants, representing all three conspicuous life history stages, that are linked by the intertwining of their basal creeping axes. Individual plants consist of a system of branched creeping axes, which is largely responsible for colonizing surrounding substrata, from which one or more erect flattened fronds arise. These erect fronds may reach a height of 15 cm, and are irregularly bipinnately branched. Internal vegetative anatomy is generally typical of the genus. Morphological variation in mature plants is limited to increased plant height and branch density during the summer season. A dorso-ventrally flattened creeping habit was seen during early recruitment on flat rock surfaces and limpet shells within grazer exclusion plots, which developed into typical erect plants. Although there is a close taxonomic affinity between G.pristoides and the low-growing Gelidium turf, which occurs on wave-cut platforms in the eastern Cape (both produce bispores), the turf appears to represent a genetically divergent ecotype of the typical G.pristoides habit. In the light of present observations, it is suggested that the recent inclusion of G.pristoides in the new Onikusa genus should be questioned. Reproduction in G.pristoides is typical of the genus, except for the production of bispores, instead of tetraspores, in the sporophyte generation. The smaller nuclei in the binucleate bispores, in comparison to carpospores, suggested they are the product of normal meiosis (meiospores). This was confi rmed by chromosome counts of germl i ngs deri ved from bispores (n = 13-17) and carpospores (2n = 28-33). Throughout the geographical range of the seaweed, the bisporophyte generation is dominant over the combined male and female gametophyte generati on by a ratio of about 3 : 1. This imbalance may be due to bispores. G.pristoides a greater germination success of carpospores over plants are fertile throughout the year, while at Port Alfred there is no apparent seasonality in spore release. Growth of carpospore and bispore germlings is similar under various temperature treatments in culture. Optimum temperatures for growth were from 15-23°C, which corresponds with the sea temperatures experienced within the geographical range of the species . At Port Alfred, growth (linear frond elongation) and standing crop levels were maximal during summer . Ory weight levels were significantly inversely related to both growth and ash levels. Agar contents (% of dry weight) were generally greater in summer (48% ) than in winter (30%), and were inversely correlated with thallus nitrogen levels. Agar contents of distal plant halves were higher (8-15%) than in proximal halves. Regrowth of G.pristoides to original biomass or standing crop levels after harvesting, is similar for plucking and shearing at different times of the year. Regrowth is more rapid after spring and summer harvests (2-3 months) than after winter harvests (4-5 months). During the summer season, harvesting at monthly intervals showed significantly greater total yields, and production rates (e.g . 3.13 g. dry wt. / m2 / day for plucking) than under 3-monthly intervals (1.42 g. dry wt. / m2 / day for plucking). In contrast, average yields per harvest were Significantly greater when recovery period was longer (e.g. 3 months). Quadrats that were completely denuded failed to recover after a year, while regrowth was also retarded with increased elevation on the shore. Agar contents did not differ Significantly between plucked (38%) and sheared (42%) plant material. G.pristoides is distributed from about 0 . 2-0.75 m above MLWS, with a reduction in stature and frequency corresponding to increased elevation on the shore. Frond elongation rates, germling survival and recruitment within grazer-exclusion plots, is retarded with increased elevation level. Plants transplanted above the normal vertical range of the seaweed became severely bleached and died, while plants transplanted below the normal range of the seaweed (sub littoral fringe) senesced due to overgrowth by the epiphytic encrusting coralline, Polyporolithon patena (Hook . et Harv . ) Mason . G.pristoides recrui t ment in the sublittoral fri nge was enhanced with the exclusion of grazers . However, successful recruits were displaced due to smothering by articulated corallines (e.g. Corallina sp. and Jania sp. ) . G.pristoides is largely restricted to cracks and crevices in the rock, and also occurs on a large proportion of the available shells of the limpet Patella oculus Born., and to a lesser extent, shells of the barnacle Tetraclita serrata. G.pristoides recruitment was significantly enhanced by the exclusion of grazers (using toxic antifouling paint barriers). G.pristoides recruitment within the exclusion plots was significantly greater on artificially attached limpet shells (almost 100% cover) than on rock surfaces (20-30% cover), which occurred largely within cracks and crevies in the rocky substratum. ly attached to limpet G.pristoides plants are significantly more strongand barnacle shells than to rock and epilithic encrusting corallines (Lithothamnion sp.). Removal of G.pristoides from limpet shells revealed pits of a uniform size in the surface of the shells, into which the rhizoidal attachment organs of the seaweed penetrate. It is concluded that the horizontal distribution of G.pristoides is largely controlled by grazers (and "escapes" from grazing) and resistance to dislodgement by wave action. Based on present results, and considering some of the socio-economic factors associated with the Gelidium industry in South Africa, suggestions are made concerning the management and long-term maintenance of G.pristoides resources in the eastern Cape.
10

Mechanistic evaluation of red algal extracts that slow aging

Snare, David Joseph 20 September 2013 (has links)
Aging results from an accumulation of damage to macromolecules inhibiting cellular replication, repair, and other necessary functions. Damage may be due to environmental stressors such as metal toxicity, oxidative stress caused by imperfections in electron transfer reactions, or other metabolic processes. In an effort to discover medical treatments that counteract this damage, we have initiated a program to search for small molecule drugs from natural sources. We have identified marine red algae as a source of natural products that slow aging of the invertebrate rotifer Brachionus manjavacas. Rotifers are a promising model organism for life extension studies as they maintain a short, measurable lifespan while also having an accepted literature precedent related to aging. Rotifer lifespan was increased 9-14% by exposure to three of 200 screened red algal extracts. Bioassay guided fractionation led to semi-purified extracts composed primarily of lipids responsible for rotifer life extension. The life extending effects of these small molecule mixtures are not a result of their antioxidant capacity; instead they may activate pathways that slow the accumulation of cellular damage. An understanding of how these natural products interact with their molecular targets could lead to selective and efficient treatments for slowing aging and reducing age related diseases.

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