This thesis is concerned with the definition of radiobiology by the Medical Research Council (MRC), the state financed medical research funding organisation, in inter-war Britain. It argues that radiobiology was largely .. defined as a specialty by struggles in surrounding fields - particularily radiology, clinical research and the bio-medical sciences. Groups within each of these fields turned to experimental research into the biological effects of radiation to further their attempts to secure an autonomous professional space within medicine, often against resistance from the leaders of medical practice. The MRC was crucial to these attempts, as it provided the first and major systematic research programme into the medical uses and biological effects of radiation during the inter-war years. However, I argue, experimental research was generally subverted to clinical objectives. Indeed, experimentalists themselves were uneasy about clinical domination of their research. However, they were farced into alliance with clinicians partly because they required a medical justification for using the Council's small supply of radium, and partly because the Council's independence in medical research was threatened by the leaders of medical practice. If the Council was not the ideal place to foster experimental research free from clinical interference, the clinicians who dominated it were also opposed to the control of research by the leaders of medical practice, and were generally mare sympathetic towards the bio-medical sciences. Con~equentlYI mast experimental scient~sts sided with these clinicians in order. to protect the Council's independence. Radiobiology reflected the accomodations each side had to make in this alliance.

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In these studies several different types of antimetabolites were synthesized, and their biological effects were examined in various assay systems. More extensive investigations were done in microbial systems in which many of the compounds proved to be inhibitory to growth, and attempts were made to determine the mode of biochemical action by adding supplements of the appropriate natural metabolite.

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Every year hundreds of cetaceans strand on New Zealand beaches. Options for dealing with disposal of their carcasses are few, creating significant problems for the Department of Conservation (DOC). More often than not their carcasses are buried in beaches at or just above high water mark, near where the animals have stranded. The primary objective of this thesis is to determine the effects of cetacean burial on beach sediments, and evaluate potential health and safety risks associated with this practice. A secondary objective of this thesis is to appraise the appropriateness of one location DOC has repeatedly transported cetacean carcasses to and buried within beach sediments, Motutapu Island in Waitemata Harbour. The chemical effects of cetacean burial over a six-month period are reported for two sites at which animals were buried in 2008, Muriwai and Pakiri beaches; the biological effects of this burial are reported for one of these sites, Muriwai Beach, 12 months post burial. Intertidal faunal and floral inventories are provided for six sites around Motutapu Island, and these then compared and contrasted with inventories compiled from an additional 290 intertidal sites between Whangarei Heads and Tauranga Harbour, North Island East Coast, to appraise the relative uniqueness of intertidal species diversity around Motutapu Island. At both Muriwai and Pakiri beaches, nitrogen and phosphate concentrations in surface sands changed considerably following cetacean burial, although over six months the effect was localized and elevated concentrations of these two chemicals that could be attributed to a buried carcass did not extend more than 40 m from the site of whale burial. Deep-core profiles revealed nitrogen and phosphate concentrations at and in the immediate vicinity of cetacean burial approximately six months after burial to be markedly elevated to the level of the water table, but elevated concentrations attributable to the buried carcass were not observed greater than 25 m from the site of burial. Elevated concentrations of nitrogen and phosphates in beaches persist in surface sediments for at least six months post burial. Twelve months post cetacean burial no significant difference in species richness or abundance were apparent in intertidal communities extending along transects proximal to and some distance from the Muriwai Beach carcass; there is no evidence for any significant short-term (to 12 months) biological effects of cetacean burial in beaches. Of those shores on Motutapu Island accessible by earth-moving equipment and large vessels capable of dealing with and transporting large cetacean carcasses, Station Bay appeared to be the most appropriate site for whale burial. However its small size and relatively high biological value (fairly high species richness for comparable shores between Whangarei Heads and Tauranga) renders it an inappropriate long-term option for whale burial. Other shores on Motutapu Island host some of the highest species richness of all shores surveyed between Whangarei Heads and Tauranga Harbour, rendering them entirely inappropriate locations for burying cetaceans, over and above other variables that may influence disposal location identification (such as archaeological sites, dwellings and accessibility). Motutapu Island is not considered an appropriate location for cetacean burial within beaches. Alternative disposal strategies need to be explored for dealing with cetaceans that strand on Auckland east coast beaches. Although burial is the most convenient and most economical strategy to dispose of cetacean carcass, especially in mass stranding events or when cetaceans are of large size, and the biological effects of this practice are not considered significant (for the one whale that could be studied), persistent enrichment of beach sediments with organic matter could result in prolonged persistence of pathogens in beaches, causing unforeseen risks to human health and safety. Recommendations are made to minimize possible threats to public following burial of cetaceans in beaches, until the potential health risks of burial are more fully understood.

Every year hundreds of cetaceans strand on New Zealand beaches. Options for dealing with disposal of their carcasses are few, creating significant problems for the Department of Conservation (DOC). More often than not their carcasses are buried in beaches at or just above high water mark, near where the animals have stranded. The primary objective of this thesis is to determine the effects of cetacean burial on beach sediments, and evaluate potential health and safety risks associated with this practice. A secondary objective of this thesis is to appraise the appropriateness of one location DOC has repeatedly transported cetacean carcasses to and buried within beach sediments, Motutapu Island in Waitemata Harbour. The chemical effects of cetacean burial over a six-month period are reported for two sites at which animals were buried in 2008, Muriwai and Pakiri beaches; the biological effects of this burial are reported for one of these sites, Muriwai Beach, 12 months post burial. Intertidal faunal and floral inventories are provided for six sites around Motutapu Island, and these then compared and contrasted with inventories compiled from an additional 290 intertidal sites between Whangarei Heads and Tauranga Harbour, North Island East Coast, to appraise the relative uniqueness of intertidal species diversity around Motutapu Island. At both Muriwai and Pakiri beaches, nitrogen and phosphate concentrations in surface sands changed considerably following cetacean burial, although over six months the effect was localized and elevated concentrations of these two chemicals that could be attributed to a buried carcass did not extend more than 40 m from the site of whale burial. Deep-core profiles revealed nitrogen and phosphate concentrations at and in the immediate vicinity of cetacean burial approximately six months after burial to be markedly elevated to the level of the water table, but elevated concentrations attributable to the buried carcass were not observed greater than 25 m from the site of burial. Elevated concentrations of nitrogen and phosphates in beaches persist in surface sediments for at least six months post burial. Twelve months post cetacean burial no significant difference in species richness or abundance were apparent in intertidal communities extending along transects proximal to and some distance from the Muriwai Beach carcass; there is no evidence for any significant short-term (to 12 months) biological effects of cetacean burial in beaches. Of those shores on Motutapu Island accessible by earth-moving equipment and large vessels capable of dealing with and transporting large cetacean carcasses, Station Bay appeared to be the most appropriate site for whale burial. However its small size and relatively high biological value (fairly high species richness for comparable shores between Whangarei Heads and Tauranga) renders it an inappropriate long-term option for whale burial. Other shores on Motutapu Island host some of the highest species richness of all shores surveyed between Whangarei Heads and Tauranga Harbour, rendering them entirely inappropriate locations for burying cetaceans, over and above other variables that may influence disposal location identification (such as archaeological sites, dwellings and accessibility). Motutapu Island is not considered an appropriate location for cetacean burial within beaches. Alternative disposal strategies need to be explored for dealing with cetaceans that strand on Auckland east coast beaches. Although burial is the most convenient and most economical strategy to dispose of cetacean carcass, especially in mass stranding events or when cetaceans are of large size, and the biological effects of this practice are not considered significant (for the one whale that could be studied), persistent enrichment of beach sediments with organic matter could result in prolonged persistence of pathogens in beaches, causing unforeseen risks to human health and safety. Recommendations are made to minimize possible threats to public following burial of cetaceans in beaches, until the potential health risks of burial are more fully understood.

Made available in DSpace on 2014-10-09T12:26:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:39Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Made available in DSpace on 2014-10-09T12:26:12Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:10:39Z (GMT). No. of bitstreams: 0 / No presente estudo a técnica de analise por ativação com nêutrons foi utilizada para a determinação simultânea da concentração de elementos, de relevância em clínica, em sangue total de Hamster Dourado. O limite de normalidade obtido para Br, Ca Cl, Mg, Na e S considerando 2 (Dois Desvios Padrão), foi de 0,011 - 0,047 gL-1 (Br); 0,11 - 0,35 gL-1 (Ca); 2,11 - 3,75 gL-1 (Cl); 1,35 - 2,79 gL-1 (K), 0,026 0,090 gL-1 (Mg), 1,03 2,51 gL-1 (Na) e 0,97 2,01 gL-1 (S) . O conhecimento desses limites viabiliza o uso de sangue total em investigações clínicas deste modelo animal. A comparação com as estimativas de normalidade em sangue total em seres humanos (Hamster & humano) permitiu verificar as similaridades ou diferenças fisiológicas, dados importantes em experimentos utilizando este modelo animal. / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

Humans have evolved under a field of low level radiation, and continue to be exposed to ubiquitous levels from natural and man-made sources including diagnostic radiology. The computerized tomography scan, in particular, plays an important role in the investigation of disease and its use increased dramatically over the years. This raises the concern that elevation in radiation exposure from x-ray modalities may increase an individual's risk for cancer. The purpose of this study is to help address this issue by measuring biological changes in lymphocytes before and after a CT scan. Venous blood was collected from eight prostate cancer patient:> before and after their scan and delivered to McMaster University at room temperature. For the dicentric assay, 0.5 ml whole blood/tube was irradiated with 3 Gy gamma rays using a 0 ;137 source and then incubated at 37°C for 46 hours. Metaphases were scored by microscopy. For apoptosis and y-H2AX, lymphocytes in media were irradiated on ice with 8 Gy and analyzed by flow cytometry. Biological effects in vivo from the CT scan were minimal for all endpoints when averaged between all donors. Overall, there was a high degree of inter-individual variation for each effect, although no correlation was found between dose (dose length product) from CT and apoptosis as well as the induction of yH2AX foci. The adaptive response also showed patient variation, and the frequency of dicentrics was the only endpoint that was lower overall following CT + 3Gy in comparison to 3 Gy alone. This research presents a challenge to current linear models of radiation associated genetic risk, and shows that individuals respond to radiation differently depending on biological factors. / Thesis / Master of Science (MSc)