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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.
21

Microbial drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa / Wernich Foit

Foit, Wernich January 2007 (has links)
Safe drinking water is a basic human right. This study mainly focused on the physicochemical and microbiological drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa. Parameters measured to determine the physico-chemical quality of drinking water were temperature, pH, total dissolved solids (TDS), electric conductivity, carbonate hardness, total hardness, NO2 -, NO3 - and chlorine. These parameters indicated hard water in the informal settlement (Sonderwater) as well as in the rural area (Ganyesa). Nitrate content were troubling for both areas, and total dissolved solids were higher than the standard in the water from Ganyesa. For microbiological quality of the water, heterotrophic plate count (HPC) bacteria, total coliforms, faecal coliforms, faecal streptococci, and staphylococci were enumerated on appropriate selective media using standard procedures. In the water from Sonderwater, faecal indicator bacteria were isolated, but none were found in the water from Ganyesa. Heterotrophic plate count bacteria and total coliforms were detected at levels above the standard in water samples from both areas. Staphylococci and faecal streptococci were present in low numbers in the water from both sites. Faecal coliforms isolated from Sonderwater showed multiple antibiotic resistances to beta-lactams. Identification of faecal coliforms from Sonderwater by API 20E strips and sequencing showed that they were Aeromonas spp. and Enterobacter spp.. Bacteria in the water from Sonderwater were tested for the potential to form biofilms. Scanning electron microscopy revealed multi-species biofilms developing in the water container after 5 days of storage. Water was sampled from four areas outside of Potchefstroom to determine a settlement gradient in water quality. Areas ranged from a formal area, through an established informal area and a newly established informal area to the newest established informal area. The water from these areas was classified as hard according to physico-chemical parameters measured, and TDS for the water from all areas were above the standard for domestic use. The established informal area had high numbers of total coliforms present in the water. Staphylococci and HPC bacteria were detected in levels higher than the standard for domestic use in all water samples. No faecal coliforms were found in the water from any of the areas. There was no visible gradient in the water quality between the areas. The water samples collected from rural, peri-urban and urban schools were also analysed in terms of physico-chemical and microbiological parameters. Water from all schools was classified as hard water. Only one school (peri-urban) had a pH above the standard. One rural school and one peri-urban school had TDS and electrical conductivity levels above the standard for domestic use. All rural and peri-urban schools had alarmingly high levels of nitrates present in the water. These schools receive groundwater as drinking water. Total coliform bacteria were present at high levels in all water samples from the schools. Rural and peri-urban schools presented levels of staphylococci and HPC bacteria higher than the standard for domestic use. Streptococci were present in water from some of the rural and peri-urban schools and one urban school. Faecal coliform/faecal streptococci ratios for rural schools indicated faecal pollution potentially of human origin, and in other schools faecal pollution from both human and animal origin. Before the vacation, faecal coliform bacteria were detected in water from all rural schools, two peri-urban schools and one urban school. After the vacation, faecal coliforms were only detected in water from two rural schools and one peri-urban school. Faecal coliforms identified and characterized showed multiple antibiotic resistances to beta-lactams, oxy-tetracycline and trimethoprim. Identification by API 20E strips and sequencing confirmed that faecal coliforms from schools were Escherichia coli and Klebsiella spp. It was concluded that water from Sonderwater were of poor quality and water from Ganyesa were acceptable with only the nitrates a troubling factor. There was no settlement gradient observed in terms of water quality between areas. Water from rural schools were generally of unacceptable quality in terms of both physico-chemical and microbiological parameters. The water quality of these schools was also very poor when compared to urban schools. Periurban schools had water quality better than rural schools, but poorer than urban schools. Surveys of water quality are recommended for all areas sampled, and education on the sanitary quality of water and related health implications is advisable for residents of informal and rural areas. / Thesis: B.Sc. Microbiology and Biochemistry School of Environmental Science and Development Faculty of Natural Sciences North-West University: Potchefstroom campus 2006.
22

Microbial drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa / Wernich Foit

Foit, Wernich January 2007 (has links)
Safe drinking water is a basic human right. This study mainly focused on the physicochemical and microbiological drinking water quality of selected rural, peri-urban and urban communities and schools in the North West Province, South Africa. Parameters measured to determine the physico-chemical quality of drinking water were temperature, pH, total dissolved solids (TDS), electric conductivity, carbonate hardness, total hardness, NO2 -, NO3 - and chlorine. These parameters indicated hard water in the informal settlement (Sonderwater) as well as in the rural area (Ganyesa). Nitrate content were troubling for both areas, and total dissolved solids were higher than the standard in the water from Ganyesa. For microbiological quality of the water, heterotrophic plate count (HPC) bacteria, total coliforms, faecal coliforms, faecal streptococci, and staphylococci were enumerated on appropriate selective media using standard procedures. In the water from Sonderwater, faecal indicator bacteria were isolated, but none were found in the water from Ganyesa. Heterotrophic plate count bacteria and total coliforms were detected at levels above the standard in water samples from both areas. Staphylococci and faecal streptococci were present in low numbers in the water from both sites. Faecal coliforms isolated from Sonderwater showed multiple antibiotic resistances to beta-lactams. Identification of faecal coliforms from Sonderwater by API 20E strips and sequencing showed that they were Aeromonas spp. and Enterobacter spp.. Bacteria in the water from Sonderwater were tested for the potential to form biofilms. Scanning electron microscopy revealed multi-species biofilms developing in the water container after 5 days of storage. Water was sampled from four areas outside of Potchefstroom to determine a settlement gradient in water quality. Areas ranged from a formal area, through an established informal area and a newly established informal area to the newest established informal area. The water from these areas was classified as hard according to physico-chemical parameters measured, and TDS for the water from all areas were above the standard for domestic use. The established informal area had high numbers of total coliforms present in the water. Staphylococci and HPC bacteria were detected in levels higher than the standard for domestic use in all water samples. No faecal coliforms were found in the water from any of the areas. There was no visible gradient in the water quality between the areas. The water samples collected from rural, peri-urban and urban schools were also analysed in terms of physico-chemical and microbiological parameters. Water from all schools was classified as hard water. Only one school (peri-urban) had a pH above the standard. One rural school and one peri-urban school had TDS and electrical conductivity levels above the standard for domestic use. All rural and peri-urban schools had alarmingly high levels of nitrates present in the water. These schools receive groundwater as drinking water. Total coliform bacteria were present at high levels in all water samples from the schools. Rural and peri-urban schools presented levels of staphylococci and HPC bacteria higher than the standard for domestic use. Streptococci were present in water from some of the rural and peri-urban schools and one urban school. Faecal coliform/faecal streptococci ratios for rural schools indicated faecal pollution potentially of human origin, and in other schools faecal pollution from both human and animal origin. Before the vacation, faecal coliform bacteria were detected in water from all rural schools, two peri-urban schools and one urban school. After the vacation, faecal coliforms were only detected in water from two rural schools and one peri-urban school. Faecal coliforms identified and characterized showed multiple antibiotic resistances to beta-lactams, oxy-tetracycline and trimethoprim. Identification by API 20E strips and sequencing confirmed that faecal coliforms from schools were Escherichia coli and Klebsiella spp. It was concluded that water from Sonderwater were of poor quality and water from Ganyesa were acceptable with only the nitrates a troubling factor. There was no settlement gradient observed in terms of water quality between areas. Water from rural schools were generally of unacceptable quality in terms of both physico-chemical and microbiological parameters. The water quality of these schools was also very poor when compared to urban schools. Periurban schools had water quality better than rural schools, but poorer than urban schools. Surveys of water quality are recommended for all areas sampled, and education on the sanitary quality of water and related health implications is advisable for residents of informal and rural areas. / Thesis: B.Sc. Microbiology and Biochemistry School of Environmental Science and Development Faculty of Natural Sciences North-West University: Potchefstroom campus 2006.
23

Anorectal Malformations : Long-term outcome and aspects of secondary treatment

Danielson, Johan January 2015 (has links)
Faecal incontinence (FI) is defined as the inability to control bowel movements. The causes of FI are many and diverse. One of the more uncommon reasons for FI is Anorectal Malformations (ARMs). An ARM is a congenital anomaly that affects somewhere between 1/2500 and 1/5000 live born babies. Many ARM patients have persistent FI. Several different procedures have been utilised to address this issue. This thesis aims to evaluate (1) the long-term outcome in adulthood of ARMs in relation to the modern Krickenbeck classification, and (2) scope for treating FI with transanal injection with dextranomer in non-animal stabilised hyaluronic acid (NASHA/Dx), in patients both with and without ARMs. All patients treated for ARMs in Uppsala up to 1993 were invited to participate in a questionnaire study of quality of life and function. The study included 136 patients and compared them with 136 age- and sex-matched controls. The Krickenbeck classification was found to predict functional outcome, and ARM patients had more problems with incontinence and obstipation, as well as inferior Quality of Life (QoL), compared with controls.  Thirty-six patients with FI, owing to causes other than ARMs, were treated with transanal submucous injection of NASHA/Dx. The patients were monitored for two years after treatment. Significant reductions in both their incontinence score and the number of their incontinence episodes were achieved.  A significant improvement in QoL was observed in patients who had at least a 75% reduction in incontinence episodes. No serious complications occurred. A prospective study of transanal injection of NASHA/Dx was conducted on seven patients with persistent FI after ARMs. After six months a significant reduction in the number of incontinence episodes was obtained. A significant improvement in QoL was also found. No serious complications occurred. In conclusion, adult patients with ARMs have inferior outcome of anorectal function and QoL compared with controls. NASHA/Dx is effective and appears to be safe in treating FI in general. This effect seems to be the same in selected patients with persistent FI after ARMs.
24

Treatment of faecal sludge from pit latrines and septic tanks using lime and urea : Pathogen die-off with respect to time of storage

Lindberg, Emma, Rost, Anna January 2018 (has links)
The study was made at Lubigi sewage treatment plant in Kampala, Uganda, during February and March 2018. The aim of this master thesis was to treat faecal sludge with two different methods, urea and lime, to investigate the efficiency of the chemicals to inactivate pathogens and to estimate the feasibility and the costs of the treatment. The chemical treatments were performed on sludge of two different moisture contents. The results from the treated sludge were compared with an untreated drying bed filled at the start of the study period to use as a control. The investigated pathogens were E. coli, bacteriophages and Ascaris eggs. The total solids and volatile solids were analysed, and the pH was measured. The results of the study including a calculation of costs were used to assess the feasibility of these treatment methods at Lubigi sewage treatment plant. The results show that the treatment using lime and urea reduces the level of active pathogens in the faecal sludge. The drying process in the beds at the treatment plant also decreases the level of detected pathogens in the sludge, but not to the same extent as when adding chemicals. The E. coli in the treated sludge were under the detection limit before the study period was done. Ascaris eggs were still detected in the sludge by the final sampling occasion. Further monitoring of the treated sludge might show an additional decrease of Ascaris since the time of storage after treatment enables pathogen die-off. The bacteriophages analyses only succeeded for two sampling occasions, although a decrease of detected phages is visible in the results. Again, the time of storage is significant for pathogen reduction, which is why a decrease of bacteriophages is expected if the sludge were to be further monitored. The feasibility of the two treatment methods is mainly restricted by costs. Lime treatment is approximately seven times more expensive than urea treatment and is also required in a larger amount to treat the sludge. On the other hand, using lime to treat faecal sludge is a proven and effective method. Further studies would improve the knowledge of the sludge characteristics at Lubigi and help determine the most preferable treatment for the sludge to protect the environment and public health. For example, by focusing on one treatment method, more detailed information can be gathered, and if performing a study in a larger scale, the representativeness would increase. To make sure there is no risk of spreading pathogens to the environment, further analyses should be carried out directly before selling the sludge to farmers.
25

Métodos de imunoensaio não radiométricos - enzimaimunoensaio (EIA) - e radiométricos - radioimunoensaio (RIA) - na avaliação dos metabólitos fecais de glicocorticoides em gatos domésticos que vivem sozinhos e em pequenas colônias / Immuneassay non radiometric - Enzime immuneassay (EIA) and radiometric - Radioimmune assay (RIA) methods - evaluation of faecal glucocorticoids metabolites in singles housed cats and cats from small colonies

Priscila Luzia Fragoso 11 July 2013 (has links)
A avaliação dos níveis de estresse nos animais tem importância tanto na área médica, econômica e de bem-estar, assim estudos vem sendo cada vez mais difundidos neste quesito. Os gatos são animais de companhia que tem progressivamente conquistado espaço no mundo moderno, dessa forma vem sendo mais observados e estudados, demonstrando-se bem mais sociais do que anteriormente se acreditava. Zelar pela qualidade de vida dos mesmos é dever do veterinário, e não somente pela questão médica em si mas também pelo bem-estar, já que se sabe, por exemplo, que condições estressantes podem levar a alterações orgânicas deletérias. A mensuração do cortisol, ou de seus metabólitos, tem sido utilizada para avaliar de forma fisiológica o bem-estar dos animais, tanto domésticos quanto selvagens. As técnicas para tal mensuração também vem sendo aperfeiçoadas, buscando-se assim ensaios mais precisos, seguros e baratos. No presente trabalho pretendemos comparar quantitativamente e qualitativamente dois imunoensaios radioimétrico (radioimunoensaio) e enzimático (enzimaimunoensaio) - utilizando amostras fecais de gatos domiciliados que vivem sozinhos ou em pequenas colônias. Sua importância deve-se ao uso de uma nova técnica, mais barata e segura, porém ainda pouco difundida no nosso país. / Evaluation of stress levels among animals has both medical and welfare importance and studies regarding this matter have been increasingly published. Cats are companion animals achieving a special position within modern societies they have been carefully observed and studied thus demonstrating that they are much more social than previously thought. Taking care of cats´ life quality is a veterinarian duty not only because it constitutes a medical issue per se but also due to its welfare implications: it is well known, for instance, that stressful conditions can lead to deleterious organic diseases. Measurement of cortisol levels (or its metabolites) has been used as a physiological parameter for investigating the welfare of both domestic and wild animals. Laboratory techniques used for such measurements have been under improvement in order to achieve more precise, safe and cheap assays. In the present study we aim at comparing quantitatively two assays radioimmunoassay and enzyme immunoassay by using domestic cats faecal samples (single and in-group housed cats). The relevance of this study lays on the use of a pioneering technique, cheap and safe, besides the establishment of a scientific cooperation with a leading university´s laboratory one of the few existing which deals with faecal hormonal dosages.
26

Suiformes conservation: a study case of strategies for DNA utilization

OLIVEIRA-MONTEIRO, NÁDIA, LOPES-RODRIGUES, VANESSA, BASTOS, ESTELA, GUEDES-PINTO, HENRIQUE 06 July 2013 (has links)
No description available.
27

Deep ocean clay crusts : behaviour and biological origin

Kuo, Matthew Yih-Han January 2011 (has links)
In water depths of 500m to greater than 2,000m, off the West coast of Africa, sediments comprise very soft clays with extremely high water contents and plasticity. In situ CPT and T-bar testing in these areas have identified 'crusts' with undrained shear strengths of up to15kPa at 0.5m depth, before the strength reduces by an order of magnitude to normallyconsolidated strengths by 2m depth. This thesis presents an investigation into the behaviour and origin of these crusts. Mini ball-penetrometer tests on natural cores confirm the crustal strength, and indicate a sensitivity of 3 within the crust. However, pipeline interface tests using the Cam-shear device demonstrate a significant variability in the measured interface friction coefficient. Particularlylow strengths are observed when shearing in an undrained manner on a rough interface. These results are attributed to the heterogeneity of natural samples, and demonstrate the need to better understand the origin of the crust material in relation to interface micro-mechanics. A microbiological investigation of crust material by extracting bacteria DNA from claysamples is described, and identifies the presence of the bacterium, Marinobacter aquaeolei. This bacterium is then used to inoculate sterile samples to determine its ability to produce crustal strength. Through this work, it is concluded that M. aquaeolei is unable to create crustal strength, although extracelluar polysaccharides produced by this bacterium will influence thepermeability of sediments through the clogging of voids. It is therefore also concluded that future geotechnical investigation into marine sediments should consider the presence of bacteriaand their ability to influence the soil properties. Wet sieving of crust material shows that the crust comprises a mixture of burrowing invertebrate faecal pellets and clay. Pellets are found to represent 20% to over 55% of the crust material by dry mass. Individual pellets are shown to exhibit unconfined compressive strengths of between 5kPa and 50kPa, thus demonstrating their strength and robustness. Consolidationbehaviour is governed by the percentage of pellets in natural samples. Based ontheir location, abundance and strength, it is concluded that the origin of crustal strength lies with the presence of burrowing invertebrate faecal pellets. When sheared on rough pipeline interfaces, however, pellets are observed to crush, expelling void-filling fragments that may generatepositive excess pore pressures. Smeared clay produced when shearing natural samplesobstructs the dissipation of pore pressures, which may encourage hydroplaning, and explainthe observation of very low interface friction coefficients. It is therefore suggested that smooth pipelines offer more sliding resistance by minimising the risk of pellet crushing. This thesis proposes that wet sieving of core samples should be undertaken during the site investigationsfor future deep-water, hot-oil pipeline installations to provide design information on both the consolidation and strength behaviour of natural sediments.
28

The sensitivity of direct faecal examination, faecal flotation and centrifugal sedimentation / flotation in the diagnosis of canine spirocercosis

Christie, Jevan Craig 25 May 2012 (has links)
A variety of faecal examination methods have shown variable sensitivity in identifying larvated Spirocerca lupi (S. lupi) eggs. The purpose of this study was to determine which faecal examination method, including a novel modified centrifugal flotation method, was most sensitive in the diagnosis of spirocercosis. Faeces were collected from 33 dogs diagnosed with spirocercosis by oesophageal endoscopy at the Onderstepoort Veterinary Academic Hospital between 2008 and 2009. If the first evaluation was negative, a second faecal sample was evaluated 24-48 h later. Ten faecal examinations using 1 g aliquots of faeces were performed per sample. Four faecal examination methods were evaluated; direct faecal examination using saline, direct faecal flotation, a modified faecal centrifugal flotation and a laboratory performed faecal sedimentation/flotation. The direct and modified centrifugal flotation methods were each performed using four faecal flotation solutions; NaNO3 (Specific gravity (SG) 1.22), MgSO4 (SG 1.29), ZnSO4 (SG 1.30) and saturated sugar (SG 1.27). The sedimentation/flotation method utilized MgSO4 (SG 1.29). The modified centrifugal flotation method required centrifugation (1400 G) of a prepared faecal suspension (1 g faeces suspended in 5 ml of flotation solution) after which 0.1 ml of the supernatant was aspirated from the surface using an adjustable volume micropipette for microscopic examination. The 10 faecal examination tests were statistically analysed using the Friedman test (nonparametric equivalent of analysis of variance) p=0.000, z value = 0.05. The sensitivity of the tests ranged between 42 % and 67 %, with the NaNO3 solution showing the highest sensitivity in both the direct and modified centrifugal flotation methods. The modified NaNO3 centrifugal method ranked first with the highest mean egg cell count (45.24 ± 83). The modified centrifugal NaNO3 method was found to be superior (i.e. higher egg counts) and significantly different (p<0.001) compared with the routine saturated sugar, ZnSO4 and MgSO4 flotation methods. The direct flotation method/technique using NaNO3 flotation fluid was also superior and significantly different (p<0.001) when compared to the same technique using ZnSO4 or MgSO4 flotation fluids. Neoplastic transformation of oesophageal nodules was confirmed in 15 % (n=5) of dogs and a further 18 % (n=6) had both neoplastic and non-neoplastic oesophageal nodules. S. lupi eggs were demonstrated in 40 % of dogs with neoplastic nodules and in 72.9 % of dogs with non-neoplastic nodules. The mean egg count in the non-neoplastic group (61) was statistically greater (p=0.02) than that of the neoplastic group (1). The results show that faecal examination using the direct and modified centrifugal flotation methods with the NaNO3 flotation fluid are the most sensitive methods in the diagnosis of spirocercosis. The modified centrifugal flotation method using this solution has the highest mean egg count. The study also found that dogs with neoplastic nodules shed significantly fewer eggs than dogs with non-neoplastic nodules. Copyright / Dissertation (MMedVet)--University of Pretoria, 2011. / Companion Animal Clinical Studies / unrestricted
29

Einfluss von fäkalem Calprotectin auf klinische Entscheidungen bei Patienten mit Morbus Crohn und Colitis ulcerosa / Impact of faecal calprotectin measurement on clinical decision-making in patients with Crohn’s disease and ulcerative colitis

Bathe, Anna Luisa 31 December 1100 (has links)
No description available.
30

Hygiene Aspects of Greywater and Greywater Reuse

Ottosson, Jakob January 2003 (has links)
<p>Greywater is domestic household wastewater without inputfrom the toilet, i.e. wastewater from sinks, the shower,washing machine and dishwasher in a home. Source separation ofgreywater can be a strategy to enhance recirculation of plantnutrients and/or improve water use. The risk for transmissionof disease when reusing greywater is largely dependent on thecross-contamination by faeces. High levels of faecalindicators, mainly thermotolerant coliform bacteria, have beenreported in greywater, indicating substantial faecal pollution.However, growth of indicator bacteria within the system leadsto an overestimation of thefaecal input and thus the hygienerisk. The faecal input of the greywater in Vibyåsen,Sollentuna, North of Stockholm, was estimated to be 0.04 ±0.02 g faeces person-1 day-1 from the quantification of thefaecal sterol coprostanol, compared to 65 g, 5.2 g and 0.22 gp-1 d-1 using E. coli, enterococci and cholesterolrespectively.</p><p>Prevalence of pathogens in the population and the faecalload based on coprostanol concentrations were used to form thebasis of a screening-level quantitative microbial riskassessment (QMRA) that was undertaken for rotavirus, Salmonellatyphimurium, Campylobacter jejuni, Giardia intestinalis andCryptosporidium parvum, looking at the treatment required to bebelow an acceptable level of risk (10-3) for reuse or dischargeof the greywater. The different exposure scenarios simulated–groundwater recharge, direct contact, irrigation andrecreational water–showed that a reduction of 0.7–3.7 log was needed for rotavirus, with the measured level offaecal load in Vibyåsen. The other pathogen of concern wasCampylobacter, where a 2.2 log reduction was needed forgroundwater recharge. The infectious dose of Salmonella is highand the excretion numbers of Giardia cysts and Cryptosporidiumoocysts low, resulting in no treatment requirements for theseorganisms under these circumstances. Pathogen input fromcontaminated food via the kitchen sink had a minor effect onthe microbiological quality of the greywater. Studies on virusoccurrence in greywater as well as validation of the faecalload of greywater at another site would give valuable input forfuture QMRAs.</p><p>Greywater treatment efficiency studies, especially on virusremoval, are scarce and more investigations are warranted.Active sludge may not be a suitable technique for greywater dueto the low carbon content in this flow. Chemical precipitationhas the advantage of removing phosphorus as well as virusesefficiently and it is suggested as one possible method fortreating greywater. Otherwise the most common practice forgreywater treatment in Sweden is soil infiltration. However, itis suggested that the recommendations for wastewaterinfiltration also be observed for greywater, despite the lowfaecal load, due to the simulated results on virus reductionneeded.</p><p><b>Key words:</b>greywater, greywater reuse, greywatertreatment, microbial risk assessment, groundwater recharge,irrigation, recreational water, faecal contamination, indicatorbacteria, index organisms, faecal sterols, bacteriophages,enteric pathogens, rotavirus, Salmonella, Campylobacter,Giardia, Cryptosporidium, Legionella</p>

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