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The effect that organic urinary macromolecules have on the crystallization of calcium oxalate from a synthetic urine-like solution was studied in a mixed suspension-mixed product removal (MSMPR) continuous crystallizer. Precipitation of calcium oxalate crystals occurs during the continuous passage of urine through the renal system (kidney, bladder and tubules). While in normal circumstances these crystals remain small in size and exit the system unimpeded, in the pathologic condition calcium oxalate crystals are observed to aggregate and grow beyond a critical size where there is a significant probability of being trapped inside the renal system, e.g., on the kidney wall or in the tubules. Once trapped, the crystals become a nidus for further solute deposition and aggregation, giving origin to a renal calculus or stone. It is shown that this process is significantly affected by the presence or absence of organic macromolecules that act as modifiers of crystal growth, nucleation, and aggregation. An ultrafiltration technique was used to fractionate urine specimens from normal (N) and stone-forming (SF) persons into organic compounds of different molecular weight. These compounds were then added to the MSMPR system to test their effect on calcium oxalate crystallization. Significant differences were found to exist between N and SF urines in the composition, molecular weight distribution, and total quantity of these organic macromolecular compounds. The fraction of macromolecules responsible for the major effects on calcium oxalate crystallization was isolated, and its effect on crystal growth and nucleation rates was quantified. The steady state driving force (supersaturation) in the MSMPR system was measured. Striking differences in supersaturation versus residence time behavior between N and SF macromolecules were observed. The experimental conditions under which calcium oxalate crystals agglomerate were identified. Evidence which supports agglomeration as a key mechanism in urinary stone formation is presented.

Doctorat en sciences médicales / info:eu-repo/semantics/nonPublished

We consider the optimization of a cost functional defined for a fluid flowing through a channeL Parameters control the shape of an obstruction in the flow, and the strength of the inflow. The problem is discretized using finite elements. Optimization algorithms are considered which use either finite differences or sensitivities to estimate the gradient of the cost functional. Problems of scaling, local minimization, and cost functional regularization are considered. Methods of improving the efficiency of the algorithm are proposed. / Ph. D.

Abstract not available

Background. Obstructive Sleep Apnoea (OSA) is associated with an increase in nocturnal gastro-oesophageal reflux (nocturnalGOR) events and symptoms, however the mechanism for this remains undefined. Treatment of OSA with continuous positive airway pressure (CPAP) has been shown to reduce nocturnalGOR in individuals with OSA however the reasons for this reduction are not clear. The combination of OSA and nocturnalGOR could be particularly problematic for individuals who have had a lung transplant in whom Bronchiolitis Obliterans Syndrome (BOS) limits survival. It is thought that GOR plays a role in the development of BOS in these individuals. Methods and Results. Five interrelated studies were undertaken. The first two studies sought to determine and compare the prevalence and risk factors of nocturnalGOR in OSA patients with the general population. To do this, a GOR questionnaire was completed by 2,042 members of the general community as part of the Busselton Health Survey and by 1,116 patients with polysomnography-diagnosed OSA. Risk of OSA in the general population was determined using a standardised sleep questionnaire. 137 of the OSA patients completed the questionnaire before and after treatment with CPAP. The prevalence of nocturnalGOR symptoms reported more than once a week (frequent symptoms) was greater in OSA patients (10.1%) than the general population (5.8%) (p<0.001), in individuals from the general population at high (11.2%) than low risk of OSA (4.5%) (p<0.001) and in patients with severe (14.7%) than mild OSA (5.2%) (p<0.001). Treatment of OSA with CPAP decreased the prevalence of frequent nocturnalGOR from 9.0% to 3.8% (p=0.04). In the general population, high risk of OSA was independently associated with a 2.4-fold increased risk of frequent ABSTRACT vi nocturnalGOR symptoms than low risk. In the OSA group, disease severity was independently associated with nocturnalGOR symptoms, with an adjusted odds ratio of 1.7 for frequent nocturnalGOR symptoms.

Aim The aim of this study was to determine the contribution of occupational exposures to the burden of Chronic Obstructive Pulmonary Disease (COPD) among a sample of hospital based patients. Methods Cases (n=110) with specialist physician diagnosed COPD from the three public sector specialist respiratory clinics in KZN and controls (n=102) from other nonrespiratory chronic ailment specialist clinics at the same institutions were selected. An interviewer administered questionnaire and exposure history was obtained for each participant. In addition, a valid lung function test was obtained for each case. Data was analysed using STATA version 10. Multivariate regression models were developed to examine the relationship between COPD and occupational exposures while adjusting for age, sex, smoking and previous history of tuberculosis. The relationship of FEV1 and occupational exposures, adjusted for age, height, previous history of tuberculosis and smoking history, was investigated among cases. Results Cases and controls were similar with respect to age and sex distribution. Cigarette smoking differed significantly between cases and controls with a larger proportion of cases having ceased to smoke compared to controls (72% vs 46%, p<0.01). A higher proportion of controls reported employment in administrative, managerial and quality control positions (21.3% vs 12.0%, 7.7% vs 2.6% and 5.4% vs 0.3% respectively). Employment in the construction and shoe manufacturing industries was reported more frequently by cases (10.3% vs 3.2% and 10.0% vs 4.9% respectively). Cases were more likely than controls to have been exposed to dust (72% vs 28%, p<0.001) or to chemicals, gas or fumes (74% vs 25.5%, p<0.001) and reported exposure durations 3-4 fold higher than that of controls (p<0.001). Dust and chemical, gas or fume exposure was associated with an increased odds of developing COPD. Exposure to dusts (OR 7.9, 95% CI 3.9-15.7, p<0.001), chemicals, gas or fumes (OR 6.4, 95% CI 3.2-12.8, p<0.001) were significantly associated with odds of developing COPD. In addition, previous history of tuberculosis, as well as smoking were associated with an increased odds of COPD (OR 5.7, 95% CI 1.2-27.4 p<0.001 and OR 6.4, 95% CI 2.3-17.7, p<0.001). Discussion and Conclusion This is one of the first hospital based case-control studies looking at occupational contribution to COPD undertaken in South Africa. In this sample of participants, strong associations were observed between self-reported occupational exposures to dust, and chemicals, gas or fumes, and physician’s diagnosis of COPD. The study also demonstrated a strong association between smoking and previous history of tuberculosis, and risk of COPD. The findings suggest that persons with known occupational exposures to respiratory irritants should be monitored to detect the onset of respiratory ill-health and that preventive strategies should reduce exposure to these agents in the workplace. / Thesis (M.Med.)-University of KwaZulu-Natal, Durban, 2009.

Orientador: Roberto Calderon Gonçalves / Resumo: A Mannheimia haemolytica A1 é o agente etiológico da Mannheimiose Pneumônica Bovina (MPB), uma doença de grande importância econômica. Um modelo experimental de MPB foi utilizado com o objetivo de avaliar os sinais clínicos, as alterações hematológicas e as espécies bacterianas das cavidades nasais e nasofaringeanas de bezerros com MPB, em diferentes momentos do curso da doença. Um total de 28 bezerros foi divido em sete lotes e os bezerros de cada lote foram distribuídos aleatoriamente em cada um dos quatro grupos. Cada grupo foi avaliado em um momento do curso da MPB: grupo I às 12, grupo II às 24, grupo III às 48 e grupo IV às 72 horas após a inoculação. Após incubação por cinco horas, a 37ºC e sob rotação de 150 ciclos/min, os inóculos da cepa D153 de M. haemolytica A1, com concentrações variando entre 1,5 x 10 8 a 8,20 x 10 9 UFCs (Unidades Formadoras de Colônias), foram infundidos na região da carina em todos os bezerros de cada lote, por via transtraqueal, enquanto eram mantidos em decúbito lateral direito. As respostas dos bezerros de cada grupo, I a IV, à M. haemolytica A1 foram caracterizadas por: hipertermia e taquicardia, com a temperatura corporal e a freqüência cardíaca tendendo a ser mais baixa nos grupos I a III e alcançando valores mais elevados no grupo IV. A freqüência respiratória aumentou em todos os grupos após a inoculação, com os valores dos grupos III e IV tendendo a ser mais elevados. Os sinais clínicos qualitativos da MPB que indicaram alterações da condição física geral, do sistema cardiovascular e alterações oculares tenderam a melhorar à medida que a doença progrediu, quando os quatro grupos foram comparados. Adicionalmente, a freqüência da secreção nasal mucosa e a intensidade da secreção nasal muco-purulenta tenderam a aumentar, concomitantemente com o aumento da... (Resumo completo, clicar acesso eletrônico abaixo). / Abstract: Mannheimia haemolytica A1 is the etiologic agent of Bovine Pneumonic Mannheimiosis (BPM), a disease of great economic importance. An experimental model of BPM was utilized with the objective of evaluating the clinical signs, hematologic changes and the bacterial species of the nasal and nasopharynx cavities of calves with BPM at different moments of the course of the disease. A total of 28 calves were divided in seven blocks, and the calves of each block were randomized to take part in one of four groups. Each group was evaluated at one moment of the course of BPM: group I at 12, II at 24, III at 48 and IV at 72 hours after inoculation. After incubation for 5 hours at 37ºC and under rotation of 150 cycles/min, the inoculums of the D153 strain of M. haemolytica A1, with concentrations varying between 1,5 x 10 8 a 8,20 x 10 9 CFU (Colonies Forming Unit), were infused at the karin region in all calves of each block, through transtraqueal route, while the calves were in right side lying. The reaction of the calves of each group (I to IV) to M. haemolytica A1 was characterized by: hipertermia and tachycardia, with body temperature and heart rate tending to be lower in groups I to III and reaching higher values in group IV. Respiratory rate increased in all groups after inoculation, with the values of groups III and IV tending to be higher. BPM qualitative clinical signs which indicated alterations of general physical condition, alterations of the cardiovascular system and ocular changes tended to improve along the progression of the disease when the four groups were compared. Additionally, the frequency of the mucous nasal... (Complete abstract, click electronic address below). / Doutor

The master thesis's topic are obstructions connected with the execution of the right to information, both by obligated entities as well as by information requestors. The right to information is a political right anchored in the Charter of Fundamental Rights and Freedoms and also in the international contracts stipulating human rights. Its definition is relatively wide, but not unlimited, because next to it from constitutional order flow other rights, freedoms or legitimate national interests, with which the right to information can be in conflict. In particular, it is concerning the law on protecting privacy or the national interest for protecting secret information, whose disclosure could endanger the national safety. The right to information can collide with other rights, freedoms or interests, therefore can be rightfully restricted and it is possible not to provide the requested information. However, such a restriction has to be anchored in the law and must be proportional and essential to the protection of rights and freedom of others, national safety, public safety, protection of public health and morals.in a democratic society. In reality, the right to information is restricted also for reasons unforeseen by the law. The right to information is nonetheless incorrectly executed even in cases of some...

Syftet med vår studie är att undersöka hur människor där den kreativa processen är central i sitt yrkesutövande upplever denna process och se om det går att hitta ett mönster. Vi bestämde oss för att ta reda på vad som händer inuti människan runt det kreativa ögonblicket. Vår huvudfrågeställning är: Vad är den kreativa processen? Vi gjorde öppna intervjuer med fem verksamma kreatörer med hjälp av DV-kamera. Vårt resultat visade att det gick att se ett gemensamt mönster i den kreativa processen. Vi fann tre teman: Flöde, Hinder och Strategier som beskrev olika faser av processen. Vi har även tittat på hur resultatet förhåller sig till formuleringarna om kunskap och lärande i Lpf 94. Detta har väckt frågor hos oss om de olika stadierna i den kreativa processen som motiverar vidare forskning inom området. Vår undersökning har på så sätt lett till nya frågeställningar. / The aim was to research how the Creative process are percieved in the creative professional and to find out if a pattern can be seen. We aimed to find out what is happening inside the person in the moment of creativity. Our main-question was: What is the Creative process? The 5 professionals was interviewed with the help of camcorders.Our result shows that a pattern can be found in the creative process. We found tree themes: Flow,Obstruction, Strategies that describe different stages in the process.We discuss our result in relation to views on knowledge and learning as expressed in LPf 94.This has created an interest in the stages of the Creative process and motivate new research. Our research has led to new inqueries.