Response of invertebrates to alien and indigenous vegetation characteristics in Nduli and Luchaba Nature Reserves, Eastern Cape, South Africa
- Authors: Yekwayo, Inam
- Date: 2012
- Subjects: Alien and indigenous vegetation -- Invertebrates , South Africa -- Eastern Cape
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:18489 , http://hdl.handle.net/11260/d1009478
- Description: Most invertebrate species are becoming extinct due to habitat loss and alien plant invasions. Hence this study aimed at determining the response of invertebrates to alien and indigenous vegetation within protected areas in the King Sabatha Dalindyebo (KSD) Local Municipality, Eastern Cape, South Africa. Invertebrates were collected using pitfall traps, during 12 sampling occasions from May 2010 to April 2011 numbers of sampling sites. Although the sampling method was adapted to collecting ground dwelling invertebrates, opportunistic flying invertebrates were also collected. A total of 7 flying invertebrate orders, 25 families, 34 species and 248 individuals were attracted to traps while 5 orders, 19 families, 50 species and 1976 individuals of soil surface-dwelling invertebrates were collected. ANOVA test showed no significant differences (p > 0.05) in species richness and abundance across sites for soil surface-dwelling invertebrates. Bray-Curtis similarity measures in PRIMER and correspondence analysis (CA) in CANOCO showed that sampling units with alien invasive plants shared most soil surface-dwelling invertebrate species at ± 75% level of similarity. Sampling unit A from the Mix alien (MA) site shared most species with indigenous vegetation sites. Sampling units from indigenous vegetation sites shared most species at ± 65% level of similarity. Multivariate analysis using CANOCO indicated that certain site variables such litter depth influenced the distribution of soil surface-dwelling invertebrates across sites. The study provided preliminary data and information for promoting invertebrate biodiversity conservation within protected areas (Nduli and Luchaba Nature Reserves) of the KSD Local Municipality. Key words: invertebrates, indigenous vegetation, alien vegetation, Lantana camara, Acacia mearnsii, and Eucalyptus.
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- Date Issued: 2012
An investigation into the localization of peptide-gold nanoparticles in an in vitro and in vivo colorectal cancer model
- Authors: Cairncross, Lynn
- Subjects: Colon (Anatomy) -- Cancer -- Treatment , Cancer -- Early detection
- Language: English
- Type: Thesis , Masters , MSc
- Identifier: vital:10351 , http://hdl.handle.net/10948/d1020921
- Description: Background: Colorectal cancer is the third most common cancer and cause of related deaths worldwide. Early colorectal cancer diagnosis is vital in reducing incidence and mortality. There is a need for the development of non-invasive screening tools for enhancing the detection of the disease. Cancer specific peptides are useful cancer targeting agents that can be used to specifically improve early detection strategies. Several cancer targeting peptides have been identified. Previous work investigated the specific binding of three of these peptides (p.C, p.L and p.14) conjugated to quantum dots and were found to bind to colorectal cancer cell lines (HT-29 and Caco-2). However, their uptake, localization and biodistribution in an in vitro and in vivo colorectal cancer model have not been determined. This is essential in gaining an understanding for future diagnostic or therapeutic based applications. Primary Aim: The aim of this study was investigate the localization of three selected peptides p.C, p.L and p.14 conjugated to gold nanoparticles in an in vitro and in vivo colorectal cancer model using HRTEM. Methodology: The AuNP/peptide conjugates were characterized by HRTEM and DLS. For in vitro studies; HT-29, Caco-2 and C3A cells were exposed to the AuNP-p.C, AuNP-p.L and AuNP-p.14, collected and processed for HRTEM to assess targeting and localization. For in vivo studies; the establishment of a colorectal cancer model using the AOM/DSS model 1 and 2 was conducted. Wistar rats were assigned to 6 groups, five experimental and 1 control group. Group 1 received AOM/DSS method 1 and was treated with AuNP-p.L. Group 2 and 3 received AOM/DSS method 2 and were treated with AuNP-p.C and AuNP-p.14. Group 4 and 5 remained healthy and treated with AuNP-p.C and AuNP-p.14. Group 6 remained healthy receiving no nanoparticle treatment. After treatment, rats were sacrificed and tissue was processed for HRTEM. Tissue chosen for HRTEM analysis included: Group 1 (inflamed colon, rectum, pancreatic and kidney), Group 4 (kidney) and Group 5 (liver). Results: results obtained from nanoparticle characterization suggested that nanoparticles were conjugated to their respective peptides and were stable in dispersion. For in vitro studies, results suggested no AuNP targeting and localization in HT-29 cell lines. For in vivo studies, no colorectal cancer tumours were induced. TEM micrographs did not indicate the presence of nanoparticles in colon, rectum, pancreatic, kidney and liver tissue. However, AuNPs were found in the kidney tissue (group 4). Conclusion: Although the overall objectives were not met, this study provided insight into TEM cell preparation and optimization for future nanoparticle cell interaction research. This study also demonstrated the absence of AuNPs in healthy tissue and the presence of AuNPs in healthy kidney tissue through renal clearance, a favourable quality for diagnostic or therapeutic applications.
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