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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

Effect of drinking water disinfection by-products in human peripheral blood lymphocytes and sperm

Ali, Aftab H.M., Kurzawa-Zegota, Malgorzata, Najafzadeh, Mojgan, Gopalan, Rajendran C., Plewa, M.J., Anderson, Diana 26 August 2014 (has links)
No / Drinking water disinfection by-products (DBPs) are generated by the chemical disinfection of water and may pose hazards to public health. Two major classes of DBPs are found in finished drinking water: haloacetic acids (HAAs) and trihalomethanes (THMs). HAAs are formed following disinfection with chlorine, which reacts with iodide and bromide in the water. Previously the HAAs were shown to be cytotoxic, genotoxic, mutagenic, teratogenic and carcinogenic. OBJECTIVES: To determine the effect of HAAs in human somatic and germ cells and whether oxidative stress is involved in genotoxic action. In the present study both somatic and germ cells have been examined as peripheral blood lymphocytes and sperm. The effects of three HAA compounds: iodoacetic acid (IAA), bromoacetic acid (BAA) and chloroacetic acid (CAA) were investigated. After determining appropriate concentration responses, oxygen radical involvement with the antioxidants, butylated hydroxanisole (BHA) and the enzyme catalase, were investigated in the single cell gel electrophoresis (Comet) assay under alkaline conditions, >pH 13 and the micronucleus assay. In the Comet assay, BHA and catalase were able to reduce DNA damage in each cell type compared to HAA alone. In the micronucleus assay, micronuclei (MNi) were found in peripheral lymphocytes exposed to all three HAAs and catalase and BHA were in general, able to reduce MNi induction, suggesting oxygen radicals play a role in both assays. These observations are of concern to public health since both human somatic and germ cells show similar genotoxic responses.
2

An archaeozoological and ethnographic investigation into animal utilisation practices of the Ndzundza Ndebele of the Steelpoort River Valley, South Africa, 1700 AD – 1900 AD

Nelson, Cindy 01 October 2009 (has links)
Focussing on Archaeozoological faunal analysis, this dissertation aims to investigate the animal food utilization practices of the Ndzundza Ndebele by combining archaeozoologcial methods, archaeological data, ethnographic and historic information. The Ndzundza Ndebele inhabited three different sites in the Steelpoort River Valley during c. 1700 AD – 1900 AD. They were forced to relocate from KwaMaza and Esikhunjini to KoNomtjarhelo as a result of continual fighting between themselves and contemporary Iron Age/Historic communities, the British and the Boers during this period. I aim to identify the animal species utilized by the Ndzundza Ndebele in addition to whether or not the hostile and politically unstable period had any effect on Ndzundza animal food procurement, use and discard. Additionally I investigate whether the faunal remains recovered from the three sites can be used to identify ethnic affiliations, gender roles and ritual use with regards to animals and/or animal parts. Ultimately, I aim to demonstrate that faunal remains cannot be fully understood and interpreted without incorporating relevant ethnographic and/or historic information and as comprehensive an archaeological context as possible. Copyright / Dissertation (MA)--University of Pretoria, 2009. / Anthropology and Archaeology / unrestricted
3

Subsistence at Si•čǝ’nǝł: the Willows Beach site and the culture history of southeastern Vancouver Island

Willerton, Ila Moana 03 September 2009 (has links)
Culture types in Pacific Northwest archaeology are characteristic artifact assemblages distinguishing different prehistoric periods. Assemblages indicate a culture type transition during the 2,630 BP–270 BP occupation of Willows Beach (DcRt-10), southeastern Vancouver Island. Faunal remains could reveal links to subsistence patterns, following Croes’s theory that culture type change reflects subsistence intensification. Five dated DcRt-10 faunal assemblages underwent taxonomic and size classification, weighing and MNI calculation. Vertebrate weight and NISP percentages were compared between stratigraphic units associated with the later Gulf of Georgia and earlier Locarno Beach culture types. The youngest assemblage contains a smaller proportion of land mammal bone, suggesting increased sea mammal, fish, and bird procurement. Faunal remains also suggest a greater variety of taxa exploited over time. Faunal assemblages suggest that culture type change at DcRt-10 is the product of subsistence change, increasing knowledge of the culture historic sequence of this region.

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