Wetlands have been described as “one of the most globally threatened and important ecosystems”, with most wetlands providing a variety of important ecosystem services, including water quality enhancement. Despite their importance the loss of wetlands is more rapid than that of any other ecosystem, which is of particular concern in South Africa, where many communities are directly and indirectly dependent on wetlands for survival. Two useful wetland assessment tools are currently used in South Africa, but a system that assesses the extent to which wetland ecosystem services (water quality enhancement in particular) are lost as a result of wetland degradation in a landscape context does not currently exist. This study therefore aims to develop a method to determine the cumulative effect of wetland degradation on water quality, which involves the exploration and integration of a number of issues, including land-cover and its effects on water quality, wetland health and its influence on the provision of ecosystem services such as water quality enhancement, and the spatial configuration of wetlands in a landscape, and its effect on water quality at a landscape scale. The method that has been developed is applied to a case study that comprises a quaternary catchment of the upper reaches of the Goukou River Wetlands in the Western Cape of South Africa. Prioritisation criteria are also explored in a series of scenarios, and the criterion and rehabilitation method that gives the best outcome in terms of water quality enhancement is applied to the case study catchment. The workings of the method are scrutinized and benefits and limitations are subsequently highlighted. An important benefit of the methodology is that many previously inadequately explored issues are integrated into a single tool that allows for prioritisation of wetlands for rehabilitation and conservation. This was achieved with South African contexts in mind. Limitations include poor responses by potential questionnaire respondents, while the scope of the study limits the inclusion of detailed aspects which would have further enhanced the accuracy of the tool and of the level of water quality enhancement explored. The methodology that is developed in this research has also not been applied to catchments with good long term water quality data in order to improve its validity. Recommendations for future research are made, which include possible refinement of the system by accounting for factors not included in the current methodology, validation of the system by applying it to a catchment with good water quality data, and the creation of software to make the system easier to use. / Thesis (M.Sc.)-University of KwaZulu-Natal, Westville, 2009.

Angiotensinogen is a blood protein that plays a critical role in the regulation of blood pressure in the body. This protein exists in two forms, oxidised and reduced, determined by the presence or absence of a disulfide bridge between Cys 18 and Cys 138. The ratio of oxidised to reduced angiotensinogen is 60:40 in the blood of healthy individuals - an equilibrium that is disrupted in women who develop pre-eclampsia, leading to a higher proportion of oxidised angiotensinogen in the blood. Pre-eclampsia, one of the leading causes of premature births, is a severe and potentially fatal pregnancy condition characterised by the sudden onset of symptoms such as high blood pressure and proteinuria typically during the third trimester. This condition is responsible for an estimated 550,000 deaths globally each year, and with no available treatment or cure other than early delivery of the child, there is a desperate need for a reliable and predictive diagnostic test for this condition. Can we use angiotensinogen as a biomarker for the early diagnosis of pre-eclampsia? Being able to distinguish between reduced and oxidised angiotensinogen and determine the relative amounts of each in blood samples would be of a huge diagnostic value for this condition. This thesis outlines the expression and purification of recombinant human angiotensinogen in Escherichia coli, and the development of an antibody-based SPR assay for angiotensinogen that was subsequently used to probe whether reduced and oxidised angiotensinogen can be distinguished experimentally. The assay developed was sensitive and reproducible, and demonstrated that the reduced and oxidised forms can be distinguished experimentally. The antibody bound the two forms with differential affinity, due to differences in both the association and dissociation rates of the two forms with the monoclonal antibody. Finally, in an attempt to further elucidate the differences between the two redox states of angiotensinogen, molecular dynamic simulations were carried out on angiotensinogen in the presence or absence of the disulfide bond between Cys 18 and Cys 138. These simulations revealed some quite striking differences in the dynamics between the two forms. Reduced angiotensinogen was found to be more dynamic in regions critical for binding to renin, providing a possible explanation for the reported differential affinity that renin displays for the two forms.1 Thus, reduced and oxidised angiotensinogen show some quite distinct differences and can be distinguished in an SPR-based assay, highlighting their potential for use as a biomarker in a diagnostic bioassay.

Bacteriological data from 1980 to 1991 were reviewed to determine whether coliform bacteria occurred seasonally and spatially within a midwestern city's distribution system. Coliform bacteria are used as microbiological indicator organisms to determine if a public water supply is safe for consumption. The public water_ distribution system examined had at least a twelve year history of the presence of coliform bacteria. Previous investigations have described the occurrence of the coliform bacteria as sporadic because there were no apparent patterns to their presence. An analysis of bacteriological data has not previously been performed to specifically detect seasonal and spatial occurrences of coliform bacteria.This study attempted to determine if seasonal or spatial patterns of coliform occurrences exist within the in the dominant coliform species. Data indicate that the highest percentage of coliform positive samples occurred in the summer, followed by fall, then winter, with spring having the lowest percentage of coliform positive samples. While Enterobacter cloacae was the dominant coliform species during the spring, summer and fall, Klebsiella oxytoca was the dominant coliform during the winter. Coliform occurrence throughout the distribution system was variable among the 43 sample sites. The percentage of positive samples from the various sites ranged from 0% to 10.5%. The five sites with the highest percentage of coliform positive samples were at the extremities of the distribution system. E. cloacae was dominant at 88% of the sites. K. oxytoca was dominant at 9% sites, which typically had a low percentage of coliform positive samples. / Department of Biology

Stuttgart, Univ., Diss., 2005.

Thesis (M.S.)--University of North Carolina Wilmington, 2006. / Includes bibliographical references (leaves: 77-79)

Thesis (M.S.)--Kutztown University. / Source: Masters Abstracts International, Volume: 45-06, page: 3039. Typescript. Abstract precedes thesis as preliminary leaves [1-4]. Includes bibliographical references (leaves [51-52]).

Thesis (M.S.)--Baylor University, 2009. / Includes bibliographical references (p. 66-76).

Made available in DSpace on 2014-06-11T19:30:26Z (GMT). No. of bitstreams: 0 Previous issue date: 2002-11Bitstream added on 2014-06-13T19:19:15Z : No. of bitstreams: 1 blanco_fmg_dr_botfca.pdf: 1170547 bytes, checksum: c187a16e76cabc346c9730542348388c (MD5) / Esta pesquisa foi realizada em Campinas SP/Brasil e teve como o objetivo estudar a persistência do herbicida sulfentrazone em solos cultivados com cana-deaçúcar e soja, e nesta, os efeitos da toxicidade do resíduo do herbicida nas culturas sucedâneas de milheto, girassol, aveia, trigo e feijão. Os solos dos ensaios com a soja e a cana-de-açúcar tiveram as seguintes características, respectivamente, 46% e 23% da argila; 12% e 13% do silte; 42% e 64% da areia 4% e 1% de MO e com pHs de 5,.8 e 6,4. As experiências foram projetadas em blocos ao acaso com 5 repetições. As amostras do solo foram coletadas na profundidade de 0-10cm, de 0-704 DAT (23 amostras) e de 0-539 DAT (24 amostras) nos experimentos de cana-de-açúcar e soja, respectivamente. A persistência do sulfentrazone foi avaliada por bioensaios usando a beterraba como a planta do teste. No ensaio com a cana-deaçúcar, os efeitos do sulfentrazone na beterraba foram detectados até 601 e 704 DAT para 0,6 e 1,2 kg a.i./ha, respectivamente. No ensaio com a soja, foram observados, os efeitos das mesmas doses até 376 e 539 DAT. Pelas análises das diversas características de desenvolvimento nas nas culturas que sucederam a soja, foi demonstrado que o resíduo do sulfentrazone afetou crescimento e o rendimento das culturas de milheto e aveia; por outro lado, o girassol e o feijão não foram afetados; o trigo foi afetado, somente, pela dose mais elevada. / This research was carried out in Campinas – SP / Brazil and had as objective to study the residual effects and persistence of sulfentrazone in sugarcane and soybean ecosystems and the toxicity of the residues of this herbicide to millet, sunflower, oats, wheat and beans cultivated in succession to soybean. The soils of the soybean and sugarcane fields had, respectively, 46% and 23% of clay; 12% and 13% of silt; 42% and 64% of sand 4% and y% of OM and pHs of 5,8 and 1,1.The experiments were designed in randomized blocks with 5 replications. Soil samples were collected at the depth of 0-10cm, from 0-704 DAT (23 timings) and from 0-539 DAT (24 timings) in sugarcane and soybean experiments, respectively. The persistence of sulfentrazone was evaluated by bioassay using sugar beet as test plant. In sugarcane field, the effects of sulfentrazone on sugar beet were detected up to 601 and 704 DAT for 0,6 and 1,2 kg a.i./ha, respectively. In soybean field the effects of the same rates were noticed up to 376 and 539 DAT. Concerning to the crops in succession to soybeans, the residues of sulfentrazone affected the growth and yield of millet and oats; sunflower and beans were not affected; wheat was affected by the higher rate, only.

Submitted by Lara Oliveira (lara@ufersa.edu.br) on 2016-11-22T16:48:40Z No. of bitstreams: 1 KalianeSS_TESE.pdf: 1965029 bytes, checksum: 2e7eb857c0039bd228f8df70999b8027 (MD5) / Approved for entry into archive by Vanessa Christiane (referencia@ufersa.edu.br) on 2017-01-24T14:46:31Z (GMT) No. of bitstreams: 1 KalianeSS_TESE.pdf: 1965029 bytes, checksum: 2e7eb857c0039bd228f8df70999b8027 (MD5) / Made available in DSpace on 2017-03-21T14:52:41Z (GMT). No. of bitstreams: 1 KalianeSS_TESE.pdf: 1965029 bytes, checksum: 2e7eb857c0039bd228f8df70999b8027 (MD5) Previous issue date: 2016-02-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The use of herbicides without the basic knowledge of their interactions with soil and climate is a high risk of environmental contamination and loss of biodiversity. To avoid these problems is essential to understand the dynamics of the herbicide in the soil. Two experiments were conducted to evaluate the dynamics of ametryn in five soils of sugar cane region of Northeast Brazil: Quartzipsamment; Ultisol; Spodosol; Oxisol and Cambisol. The first experiment evaluated the leaching ametryn in said soil by means of liquid chromatography and bioassay. It was observed that the leaching of the herbicide was influenced by the physicochemical characteristics of the soil, with the following leaching potential sequence: Quartzipsamment> Oxisol> Ultisol> Cambisol> Spodosol and the Quartzipsamment showed higher concentration of ametryn the layer 5 to 10 cm deep, indicating possible loss of agronomic efficiency and contamination of groundwater. The second experiment evaluated the persistence of ametryn in soils mentioned by bioassays and liquid chromatography. It was noted that the persistence of the herbicide varied depending on the physical and chemical properties of the soil, with a halflife (t ½) of 49 days to Quartzipsamment, 35 days for Ultisol, 28 days for Spodosol, Oxisol and Cambisol. Intoxication visual symptoms caused by ametryn occurred up to 133 days to Quartzipsamment and Spodosol, 168 days for Ultisol, Oxisol and Cambisol / O uso de herbicidas sem os conhecimentos básicos de suas interações com o solo e clima representa alto risco de contaminação ambiental e redução da biodiversidade. Para evitar esses problemas é fundamental compreender a dinâmica do herbicida no solo. Dois experimentos foram conduzidos, visando avaliar a dinâmica do ametryn em cinco solos da região canavieira do Nordeste brasileiro: Neossolo Quartzarênico; Argissolo; Espodossolo; Latossolo e Cambissolo. O primeiro experimento avaliou-se a lixiviação do ametryn nos referidos solos por meio de bioensaios e cromatografia líquida. Observou-se que a lixiviação do herbicida foi influenciada pelas características físico-químicas dos solos, apresentando a seguinte sequência de potencial de lixiviação: Neossolo Quartzarênico> Latossolo> Argissolo> Cambissolo> Espodossolo e que o Neossolo Quartzarênico apresentou maior concentração do ametryn na camada de 5 a 10 cm de profundidade, indicando possibilidade de perda da eficiência agronômica e contaminação de águas subterrâneas. O segundo experimento avaliou-se a persistência do ametryn nos solos mencionados por meio de bioensaios e cromatografia líquida. Observou-se que a persistência do herbicida variou em função dos atributos físicos e químicos dos solos, com meia-vida (t½) de 49 dias para o Neossolo Quartzarênico, 35 dias para o Argissolo, 28 dias para Espodossolo, Latossolo e Cambissolo. Sintomas visuais de intoxicação causados pelo ametryn ocorreram até aos 133 dias para o Neossolo Quartzarênico e Espodossolo, 168 dias para o Argissolo, Latossolo e Cambissolo

p. 1-94 / Submitted by Santiago Fabio (fabio.ssantiago@hotmail.com) on 2013-04-10T20:41:09Z No. of bitstreams: 1 Dissertacao seg16.pdf: 1967541 bytes, checksum: 6f4222d44500c9ca816ba7cfef0084e4 (MD5) / Approved for entry into archive by Alda Lima da Silva(sivalda@ufba.br) on 2013-04-15T20:16:47Z (GMT) No. of bitstreams: 1 Dissertacao seg16.pdf: 1967541 bytes, checksum: 6f4222d44500c9ca816ba7cfef0084e4 (MD5) / Made available in DSpace on 2013-04-15T20:16:48Z (GMT). No. of bitstreams: 1 Dissertacao seg16.pdf: 1967541 bytes, checksum: 6f4222d44500c9ca816ba7cfef0084e4 (MD5) Previous issue date: 2005 / O presente estudo teve como principais objetivos: avaliar o comportamento do efluente, lançado no rio, durante um ciclo de maré; estimar a carga de fósforo (P) que a ETE lança no rio e, através de bioensaio, determinar o possível efeito deste efluente no crescimento de microalgas. Foram coletadas amostras na ETE e no estuário para análises de parâmetros físico-químicos, nutricionais, clorofila a e produção primária. Na ETE foram realizadas coletas de superfície ao longo do dia. No estuário foram feitas coletas na coluna d?água em intervalos regulares (3h).O bioensaio foi conduzido sob condições controladas de luz e temperatura, utilizando Pseudokirchineriella. subcapitata como organismo-teste. A culturas foram expostas a diferentes concentrações do efluente durante os períodos de 96 e 144 horas. Os resultados indicaram que o efluente é constituído de uma elevada carga nutricional (166 a 183µM de fósforo total e 329 a 394µM de nitrogênio total) e lança uma carga diária de 14kg de fósforo no rio. A E1 é fortemente influenciada pela entrada do efluente, o qual parece não atingir a E2. Isso foi confirmado, principalmente, pela razão nitrogênio e fósforo (N/P), que indicou para a E1 uma maior proporção de fósforo em relação ao nitrogênio (N/P < 16), e pela maior produtividade primária (51,38 mgC/m3/h) em relação a E2 (3,33 mgC/m3/h), cujo resultado foi atribuído à maior disponibilidade nutricional, principalmente o fósforo. Apesar da rápida diluição do efluente, a entrada excessiva de nutrientes em ecossistemas aquáticos é sempre preocupante, em especial o fósforo, pois seu potencial eutrofizante nunca é reduzido. O bioensaio demonstrou que o efluente induz o crescimento das algas mesmo nas maiores diluições, indicando a sua riqueza de nutrientes. O efluente tem potencial de eutrofização, e por isso pode comprometer a qualidade da água do Rio Sauípe. / Salvador