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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.
41

Patterns of resource allocation in Caribbean coral reef sponges

Leong, Wai January 2009 (has links) (PDF)
Thesis (M.S.)--University of North Carolina Wilmington, 2009. / Title from PDF title page (January 12, 2010) Includes bibliographical references (p. 52-55)
42

Studies in the evolution of creatine and arginine kinases in the basal metazoan sponges

Bertin, M., Ellington, W. Ross. January 1900 (has links)
Thesis (M. S.)--Florida State University, 2006. / Advisor: W. Ross Ellington, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Dec. 12, 2006). Document formatted into pages; contains xii, 77 pages. Includes bibliographical references.
43

Sponge community structure and anti-predator defenses on temperate reefs of the South Atlantic Bight

Ruzicka, Richard Robert. January 2005 (has links) (PDF)
Thesis (M.S.)--Georgia Southern University, 2005. / "A thesis submitted to the Graduate Faculty of Georgia Southern University in partial fulfillment of the requirements for the degree Master of Science" ETD. Includes bibliographical references (p. 74-82) and appendices.
44

La bioremédiation in situ des parcs conchylicoles par les éponges marines est-elle envisageable ? / Is bioremediation of shellfish farms by marine sponges possible ?

Gentric, Charline 06 June 2016 (has links)
La préservation de la qualité des eaux marines et la lutte contre les pollutions liées à l'activité humaine sont devenues des enjeux mondiaux. De nombreux contaminants biologiques et polluants chimiques se retrouvent dans l’eau de mer, par conséquent dans les produits aquacoles. Ce contexte fait qu’aujourd’hui, les professionnels de la mer sont à la recherche de solutions pour préserver voire améliorer la qualité de leurs eaux. Au sein de notre biodiversité, les éponges marines sont des animaux capables de filtrer 10 000 fois leur volume en eau par jour et de retenir 80% des particules en suspension comme la matière organique, les minéraux, les bactéries et les virus. Par la même occasion, elles accumulent certains éléments traces métalliques comme le plomb, le cadmium ou le cuivre. En collaboration avec le Comité Régional de Conchyliculture de Bretagne Sud, le projet REMEDBIO dans lequel s’inscrit cette thèse se propose d'exploiter le potentiel de filtration des éponges marines du littoral breton. Les objectifs sont de contrôler le développement de bactéries pathogènes et de réduire la présence de polluants chimiques. L’éponge marine Hymeniacidon perlevis (Demospongiae) a été choisie comme modèle pour cette étude. Après avoir mis en évidence la faisabilité de la culture d’éponges marines sur l’estran, notre travail a montré, lors d’essais in vitro, une diminution de la contamination des huîtres par deux bactéries, Escherichia coli et Vibrio aestuarianus, et par le plomb, un élément trace métallique, en présence d’éponges. La dernière phase de ce travail a consisté à valoriser les résultats obtenus. Le projet d’entreprise LECOMER a débuté par le concours START’UBS (lauréat) proposé par l’Université de Bretagne Sud en 2014. Par la suite, LECOMER a été élu lauréat des Trophées de l’Innovation du Morbihan 2014. / The conservation of waters quality and the fight against pollution due to human activities havebecome global issues. Many biological contaminants and chemical pollutants are found in sea water, therefore in aquaculture products. This context fact sea professional are looking for solutions to preserve or even improve the quality of their waters. Among marine biodiversity, marine sponges filter 10 000 times their volume of water per day and retain 80 % of suspended particles such as organic matter, minerals, bacteria and viruses. In addition, sponges are therefore considered as bio-accumulators of metallic trace element such as lead, cadmium or copper. In collaboration with the Comité Régional de Conchyliculture de Bretagne Sud, REMEDBIO project proposes to exploite potential of marine sponges of the Brittany coast. One of the main priorities of this project is to reduce the impact of chemicals (heavy metals) and of biological contaminants (bacteria, viruses) on shellfish breeding. The marine sponges Hymeniacidon perlevis (Demospongiae) was chosen as the model for this study. Having demonstrated the feasibility of the culture of marine sponges on the foreshore, our work has shown, when tested in vitro, reduced contamination of oysters by two bacteria, Escherichia coli and Vibrio aestuarianus, and lead, a metal trace element, in the presence of sponges. The last phase of this work has been to enhance the results. The company LECOMER project began with the START'UBS contest (winner) proposed by the Université de Bretagne Sud in 2014. Thereafter, LECOMER was elected winner of the Innovation Awards of Morbihan in 2014.
45

Matrix comparison of isolation conditions for secondary metabolite producing marine sponge associated bacteria

Matobole, Relebohile Matthew January 2015 (has links)
>Magister Scientiae - MSc / The discovery of novel secondary metabolites has declined significantly in recent years whereas there is a rise in the number of multi-drug resistant pathogens and other types of diseases. The decline in natural product discovery was due to high rediscovery of already known compounds and the costs in developing natural products. As a result pharmaceutical companies lost interest in investing in natural product discovery. However, there is a renewed interest in marine sponge associated microorganisms as a rich and untapped source of secondary metabolites. The objective of this study was to design a matrix to investigate the extent to which the One Strain-Many Compounds (OSMAC) approach applies to a collection of marine sponge isolates harvested from two South African marine sponge samples. Terminal restriction fragment length polymorphisms (T-RFLP) analysis was used to investigate and ascertain the two marine sponges which hosted the highest microbial diversities to be used for further culture-dependent studies. The culture-dependent studies, using 33 media which included liquid enrichment, heat treatments and antibiotic treatments, resulted in 400 sponge isolates from the two marine sponges Isodictya compressa and Higginsia bidentifera. Using antibacterial overlay assays, 31 dereplicated isolates showed antibacterial activity. Bioactivities were also exhibited against E. coli 1699 which is genetically engineered for resistance against 52 antibiotics which implies that some of the bioactive compounds could be novel. The 16S rRNA gene sequences revealed that the microbial phyla isolated from the marine sponges belonged to Actinobacteria, Firmicutes and Proteobacteria (Alphaproteobacteria and Gammaproteobacteria).Thirty isolates were selected for an OSMAC-based matrix study, 17 of which showed noantibacterial activities in preliminary screening. The application of the OSMAC approach using co-culture and 36 culture conditions resulted in 6 isolates showing antibacterial activities, three of which did not show activities in preliminary screening. One of these, a Bacillus pumilus isolated from I. compressa displayed antibacterial activity against 5 indicator strains whereas in preliminary screening it had not shown activity. The results show that marine sponges can host novel microbial species which may produce novel bioactive compounds. The results also confirm that traditional methods employing a single culture condition restricts the expression of some biosynthetic pathways of microorganisms and as a result many metabolites have yet to be identified.
46

Screening bacterial symbionts of marine invertebrates for ribosomally synthesized natural products

Hanekom, Thea January 2016 (has links)
>Magister Scientiae - MSc / Pharmaceutical research and development strategies rely on the constant discovery of novel natural products as potential drugs. Recent studies have shown that the microorganisms associated with sponges are the true producers of some previously isolated compounds. This study created a large collection of bacterial symbionts associated with the South African marine sponge, Hamacantha esperioides. The bioactivity assays performed, showed that 44 isolates produced compounds with antimicrobial or anti-inflammatory activity. The successful identification of novel species that produce potential natural products highlights the importance of cultivation-dependent methods. To further screen for natural products, a cultivation-independent approach was used. A sequenced-based method, based on the biosynthetic genes of polytheonamide, was developed to screen for proteusins in sponge metagenomic DNA and the genomes of bacterial symbionts. The degenerate primers could amplify the targeted genes from DNA known to contain homologues. Evaluation of the primers' specificity showed non-specific amplification of genes, some containing similar conserved domains as the target genes. This study demonstrated that the use and development of cultivation-dependent and -independent screens are important for the discovery of novel natural products from the symbiotic bacteria of South African sponges. / National Research Foundation (NRF)
47

Studies on the diversity and spatial distribution of deep-water sponges along the west and south coasts of South Africa

Maduray, Seshnee January 2013 (has links)
Magister Scientiae (Biodiversity and Conservation Biology) - MSc (Biodiv and Cons Biol) / This thesis explores the diversity, spatial patterns and community structure for the sponges (Porifera) along the west and south coasts of South Africa. Species collected were identified to the lowest level of lowest taxonomic unit possible (either species or genus). The study site was divided into areas and in each of these we documented the spatial diversity and in so doing were able to assess the variation of sponge communities between the west and south coasts. The total number of species recorded for this deep-water region was eighty-three of which nineteen are described. The south coast was more diverse than the west coast and eleven species were found to be common to both coasts. The analysis based on location and depth showed that both coasts are significantly different to each other. We determined that these areas are biogeographically separated. Species contributing toward the dissimilarity between both coasts include Suberites carnosus, Myxilla (Burtonanchora) sp 1, Rossella antarctica, Tetilla capillosa and Haliclona sp. Patterns of species richness showed an increase in diversity from the west to south. It was found that species richness increases with depth for both coasts but only up to 350 m for the west coast and 200 m for the south coast. However, the sampling effort was determined to possibly have not been enough to gain a full understanding of species richness for the entire study area as the number of species was correlated with sampling effort. Estimated richness found that higher richness of sponges could still be found within most of the best bins and for each coast. An estimate of samples needed both each depth bin per coast showed that more samples would be needed on the south coast and this is possibly due to the greater variety and variability of the species found on the coast. The sponge community on the south coast was found to have no significant difference in pattern with some of the depth bins, whereas depth plays a role in sponge community on the west coast. Species of Suberites were dominant at depths lower than 200 m while Hamacantha (Vomerula) esperioides was dominant between 200 and 350 m with Tetilla capillosa dominated depths lower than 350 m. The thesis is concluded with an overview of what is now known and what still needs to be discovered and determined to further enhance biodiversity knowledge in the country.
48

Taxonomy, distribution and ecology of the freshwater sponges (Porifera:Spongillidae) and bryozoans (Ectoprocta) of eastern Canada

Ricciardi, Anthony January 1992 (has links)
No description available.
49

Geological significance of boring sponges on Barbados reefs

MacGeachy, James Kirk. January 1978 (has links)
Note:
50

Synthesis and characterization of C-TiC bioceramics. / 碳-碳化鈦生物陶器之合成與表徵 / Synthesis and characterization of C-TiC bioceramics. / Tan-tan hua tai sheng wu tao qi zhi he cheng yu biao zheng

January 2006 (has links)
by Tang Wing Chi = 碳-碳化鈦生物陶器之合成與表徵 / 鄧詠芝. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references. / Text in English; abstracts in English and Chinese. / by Tang Wing Chi = Tan-tan hua tai sheng wu tao qi zhi he cheng yu biao zheng / Deng Yongzhi. / Acknowledgement --- p.i / Abstract --- p.ii / 摘要 --- p.iv / Table of contents --- p.vi / List of figures --- p.xi / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Biomorphic materials --- p.1-1 / Chapter 1.2 --- Synthesis of biomorphic ceramics --- p.1-1 / Chapter 1.2.1 --- Pyrolysis --- p.1-2 / Chapter 1.2.1.1 --- Pyrolysis conditions --- p.1-3 / Chapter 1.2.2 --- Infiltration --- p.1-4 / Chapter 1.2.2.1 --- Vapor or gas infiltration --- p.1-4 / Chapter 1.2.2.2 --- Liquid infiltration --- p.1-4 / Chapter 1.2.2.3 --- Chemical vapor infiltration (CVI) --- p.1-5 / Chapter 1.2.2.4 --- Sol-gel processing --- p.1-5 / Chapter 1.2.3 --- Sintering --- p.1-6 / Chapter 1.3 --- Potential applications of biomorphic ceramics --- p.1-7 / Chapter 1.3.1 --- Homogenous porosity structures --- p.1-7 / Chapter 1.3.2 --- Heterogeneous porosity structures --- p.1-7 / Chapter 1.4 --- Methods and raw materials --- p.1-8 / Chapter 1.4.1 --- Infiltration --- p.1-8 / Chapter 1.4.2 --- Starting materials --- p.1-8 / Chapter 1.4.2.1 --- Ti source --- p.1-8 / Chapter 1.4.2.2 --- Biotemplates --- p.1-9 / Chapter 1.5 --- Objectives and approaches --- p.1-9 / Chapter 1.6 --- Thesis layout --- p.1-10 / References --- p.1-11 / Figures --- p.1-13 / Chapter Chapter 2 --- Methodology and Instrumentation / Chapter 2.1 --- Introduction --- p.2-1 / Chapter 2.2 --- Synthesis --- p.2-1 / Chapter 2.2.1 --- Biomorphic C-TiC ceramics from dragon tree --- p.2-1 / Chapter 2.2.2 --- Biomorphic C-TiC ceramics from wool sponge --- p.2-2 / Chapter 2.3 --- Characterization methods --- p.2-3 / Chapter 2.3.1 --- Differential thermal analyzer (DTA) --- p.2-3 / Chapter 2.3.2 --- Scanning electron microscopy (SEM) --- p.2-4 / Chapter 2.3.3 --- X-Ray powder diffractometry (XRD) --- p.2-4 / Chapter 2.3.4 --- Transmission electron microscopy (TEM) --- p.2-4 / Chapter 2.3.5 --- X-ray photoelectron spectroscopy (XPS) --- p.2-6 / Chapter 2.3.6 --- Compression tests --- p.2-6 / References --- p.2-9 / Figures --- p.2-8 / Chapter Chapter 3 --- The starting materials / Chapter 3.1 --- Introduction --- p.3-1 / Chapter 3.2 --- Fresh dragon tree --- p.3-1 / Chapter 3.2.1 --- SEM results --- p.3-1 / Chapter 3.2.2 --- Discussions --- p.3-2 / Chapter 3.3 --- Fresh sea wool sponge --- p.3-2 / Chapter 3.3.1 --- SEM results --- p.3-3 / Chapter 3.3.2 --- Discussions --- p.3-3 / Chapter 3.4 --- Tyzor-LA solution --- p.3-3 / Chapter 3.4.1 --- Physical properties --- p.3-4 / Chapter 3.4.2 --- DTA results --- p.3-4 / Chapter 3.4.3 --- XRD results --- p.3-5 / Chapter 3.4.4 --- Discussions --- p.3-5 / Chapter 3.5 --- Conclusions --- p.3-6 / References --- p.3-7 / Figures --- p.3-8 / Chapter Chapter 4 --- Results and discussions of biomorphic products fabricated from dragon tree / Chapter 4.1 --- Introduction --- p.4-1 / Chapter 4.2 --- Fabrication of biomorphic C-TiC ceramics --- p.4-1 / Chapter 4.2.1 --- Biotemplates from dragon tree --- p.4-1 / Chapter 4.2.1.1 --- XRD results --- p.4-1 / Chapter 4.2.1.2 --- SEM results --- p.4-2 / Chapter 4.2.1.3 --- Discussions --- p.4-2 / Chapter 4.2.2 --- Biomorphic C-TiC ceramics --- p.4-3 / Chapter 4.2.2.1 --- XRD results --- p.4-3 / Chapter 4.2.2.1.1 --- Effects of sintering temperature --- p.4-3 / Chapter 4.2.2.1.2 --- Effects of time duration --- p.4-3 / Chapter 4.2.2.2 --- SEM results --- p.4-4 / Chapter 4.2.2.3 --- TEM results --- p.4-4 / Chapter 4.2.2.3.1 --- Sample sintered at 1400。C for 6 hours --- p.4-4 / Chapter 4.2.2.3.2 --- Sample sintered at 1200°C for 6 hours --- p.4-5 / Chapter 4.2.2.3.3 --- Sample sintered at 1100。C for 6 hours --- p.4-5 / Chapter 4.2.2.3.4 --- Sample sintered at 900°C for 32 hours --- p.4-6 / Chapter 4.2.2.4 --- XPS results --- p.4-6 / Chapter 4.2.2.5 --- Results of compression tests --- p.4-7 / Chapter 4.2.2.6 --- Discussions --- p.4-7 / Chapter 4.3 --- Biomorphic C-TiC ceramics by repeated infiltration --- p.4-10 / Chapter 4.3.1 --- XRD results --- p.4-10 / Chapter 4.3.2 --- Discussions --- p.4-10 / Chapter 4.4 --- Conclusions --- p.4-11 / References --- p.4-12 / Figures --- p.4-13 / Chapter Chapter 5 --- Results and discussions of biomorphic products fabricated from sea wool sponges / Chapter 5.1 --- Introduction --- p.5-1 / Chapter 5.2 --- Fabrication of C-TiC biomorphic ceramics with sea wool sponges --- p.5-1 / Chapter 5.2.1 --- XRD results --- p.5-1 / Chapter 5.2.2 --- SEM results --- p.5-2 / Chapter 5.2.3 --- TEM results --- p.5-3 / Chapter 5.2.4 --- Discussions --- p.5-3 / Chapter 5.3 --- Dilution of Tyzor-LA solution --- p.5-5 / Chapter 5.3.1 --- XRD results --- p.5-5 / Chapter 5.3.2 --- SEM results --- p.4-5 / Chapter 5.3.3 --- Discussions --- p.5-6 / Chapter 5.4 --- Further annealing of biomorphic C-TiC ceramics in air --- p.5-6 / Chapter 5.4.1 --- XRD results --- p.5-7 / Chapter 5.4.2 --- SEM results --- p.5-7 / Chapter 5.4.3 --- TEM results --- p.5-8 / Chapter 5.4.4 --- Discussions --- p.5-9 / Chapter 5.5 --- Conclusions --- p.5-11 / References --- p.5-12 / Figures --- p.5-13 / Chapter Chapter 6 --- Conclusions and future works / Chapter 6.1 --- Conclusions --- p.6-1 / Chapter 6.2 --- Future works --- p.6-2 / References --- p.6-4

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