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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.
61

Estimating trade flows : case of South Africa and BRICs

Manzombi, Prisca 03 1900 (has links)
This study examines the fundamental determinants of bilateral trade flows between South Africa and BRIC countries. This is done by exploring the magnitude of exports among these countries. The Gravity model approach is used as the preferred theoretical framework in explaining and evaluating successfully the bilateral trade flows between South Africa and BRIC countries The empirical part of this study uses panel data methodology covering the time period 2000-2012 and incorporates the five BRICS economies in the sample. The results of the regressions are subject to panel diagnostic test procedures. The study reveals that, on the one hand, there are positive and significant relationships between South African export flows with the BRICs and distance, language dummy, the BRICs’ GDP, the BRICs’ openness and population in South Africa. On the other hand, GDP in South Africa, real exchange rate and time dummy are found to be negatively related to export flows. / Economics / M. Com. (Economics)
62

Estudo da viabilidade para introduzir na rotina testes de diagnóstico para infecção respiratória aguda / Feasibility study to introduce the routine diagnostic tests for acute respiratory infection

Furlan, Teresa Maria 18 April 2016 (has links)
Para avaliar os benefícios da comunicação rápida ao clínico do diagnóstico de vírus respiratórios, foi analisado a viabilidade econômica de 2 testes, com o tempo de entrega de resultado em 2 horas para teste rápido e 48 horas para Biologia Molecular. As amostras coletadas foram processadas utilizando técnicas convencionais e os testes disponíveis no mercado local. Foram escolhidos dois testes rápidos pelo método de imunocromatografia para quatro parâmetros analíticos: Influenza A, Influenza H1N1, Influenza B e Vírus Sincicial Respiratório (RSV) e em Biologia Molecular um teste de RT-PCR multiplex com 25 patógenos entre vírus e bactérias. O tipo de amostra utilizada foi swab e lavado de nasofaringe. A população escolhida para o estudo foi paciente adulto, em tratamento de câncer, que necessita de uma resposta rápida já que a maioria se encontra com comprometimento do sistema imune por doença ou por tratamento. O estudo foi transversal, realizado entre os anos de 2012 e 2013, para avaliar a viabilidade econômica da introdução de testes de diagnóstico da infecção respiratória aguda de etiologia viral a partir de amostras de nasofaringe em pacientes com câncer atendidos no Centro de Atendimento de Oncologia Intercorrência (CAIO ), do Instituto do Câncer do Estado de São Paulo (ICESP), hospital público que atende exclusivamente Sistema Único de Saúde (SUS) e Hospital A.C. Camargo, que atende tanto a pacientes do SUS como da rede privada. O estudo incluiu 152 pacientes em tratamento para qualquer tipo de câncer, predominantemente do sexo feminino (81 mulheres e 70 homens) com idades entre 18-86 anos. Para participar do estudo o paciente era consultado e o critério para escolha do paciente foi ser portador de câncer, com história de febre (ainda que referida) acompanhada de tosse ou dor de garganta, tosse e sintomas respiratórios agudos, atendidos por protocolo padronizado que inclui avaliação na admissão, seguimento e manejo antimicrobiano. Para a avaliação econômica os pacientes foram classificados de acordo com o estado geral de saúde, se apresentavam bom estado de estado de saúde poderiam receber alta e faziam uso da medicação em casa evitando 5 dias de internação se recebessem algum resultado para Influenza ou RSV, no entanto os pacientes que apresentavam outro vírus, resultado negativo ou o estado geral era ruim permaneciam internados por 7 dias em observação e cuidados com medicação adequada. Foram realizadas análises econômicas em dois âmbitos: o sistema de saúde publico e o privado considerando o fator diminuição de dias de internação. A analise de Custo-benefício foi eficiente no Sistema privado mas inadequada para o SUS assim como, qualquer outra medida monetária já que os valores de reembolso do SUS estão defasados do custo de qualquer internação. A análise de Custo-efetividade que olha para outros fatores além do monetário foi efetiva nos dois sistemas que enfrentam falta de leitos além da condição de saúde do paciente de evitar a ingestão desnecessária de antibióticos, evitar os gastos do acompanhante, perda de dias de trabalho e estudo. Não houve correspondência de resultados dos testes rápidos com o multiplex de Biologia Molecular / To evaluate the benefits of the rapid communication of the respiratory viruses\' diagnosis to the doctor, the economic feasibility of two tests was analyzed, with the result delivery time within 2-hours for the rapid test and 48 hours for Molecular Biology. The samples were processed using conventional techniques and the available tests in the local market. Two rapid tests were selected by the immunochromatography method for four analytical parameters: Influenza A, Influenza A H1N1, Influenza B, and Respiratory Syncytial Virus (RSV) and in Molecular Biology a multiplex RT-PCR assay with 25 pathogens between viruses and bacteria. The type of sample used was swab and nasopharyngeal wash. The population chosen for the study was of adult patients undergoing cancer treatment, which requires a rapid response since most have a compromised immune system due to the disease or treatment. The study, conducted between 2012 and 2013, was cross-sectional to evaluate the economic feasibility of introducing diagnostic tests for acute respiratory infection of viral etiology from nasopharyngeal samples of patients with cancer attended at the Oncology Intercurrence Care Center (CAIO), at the Cancer Institute of the São Paulo State (ICESP), at public hospital that attends exclusively the Unified Health System (SUS) and at AC Camargo hospital, which attends SUS patients as well as the private health system. The study included 152 patients undergoing treatment for any type of cancer, predominantly female (81 women and 70 men) between 18 and 86 years. To participate in the study, the patients were consulted and the criteria for choosing a patient was to be a cancer patient with a history of fever (even if referred) accompanied by cough or sore throat, coughing and acute respiratory symptoms, attended by standardized protocol that includes an evaluation at the admission, tracking and antimicrobial management. For the economic evaluation, patients were classified according to the general health condition. If they were in a good health condition, they could receive medical discharge and make use of the medication at home avoiding five days of hospitalization when receiving a result for influenza or RSV. However, the patients with other viruses, negative results or with bad general condition remained hospitalized for seven days under observation and care with proper medication. Economic analyzes were carried out in two areas: the public health system and private health system considering the factor decreased length of hospital stay. The cost-benefit analysis was efficient in the private system but inadequate for the NHS as well as any other monetary measure since the SUS reimbursement values are too low when compared to the cost of any other hospital. The cost-effectiveness analysis that looks at other factors besides money was effective in both systems that were facing lack of beds in addition to the health condition of the patient to avoid unnecessary intake of antibiotics, avoid the costs of the accompanying person, loss of working and study days. There were no results correspondences of the rapid tests with the Molecular Biology multiplex
63

Bayesian methods and machine learning in astrophysics

Higson, Edward John January 2019 (has links)
This thesis is concerned with methods for Bayesian inference and their applications in astrophysics. We principally discuss two related themes: advances in nested sampling (Chapters 3 to 5), and Bayesian sparse reconstruction of signals from noisy data (Chapters 6 and 7). Nested sampling is a popular method for Bayesian computation which is widely used in astrophysics. Following the introduction and background material in Chapters 1 and 2, Chapter 3 analyses the sampling errors in nested sampling parameter estimation and presents a method for estimating them numerically for a single nested sampling calculation. Chapter 4 introduces diagnostic tests for detecting when software has not performed the nested sampling algorithm accurately, for example due to missing a mode in a multimodal posterior. The uncertainty estimates and diagnostics in Chapters 3 and 4 are implemented in the $\texttt{nestcheck}$ software package, and both chapters describe an astronomical application of the techniques introduced. Chapter 5 describes dynamic nested sampling: a generalisation of the nested sampling algorithm which can produce large improvements in computational efficiency compared to standard nested sampling. We have implemented dynamic nested sampling in the $\texttt{dyPolyChord}$ and $\texttt{perfectns}$ software packages. Chapter 6 presents a principled Bayesian framework for signal reconstruction, in which the signal is modelled by basis functions whose number (and form, if required) is determined by the data themselves. This approach is based on a Bayesian interpretation of conventional sparse reconstruction and regularisation techniques, in which sparsity is imposed through priors via Bayesian model selection. We demonstrate our method for noisy 1- and 2-dimensional signals, including examples of processing astronomical images. The numerical implementation uses dynamic nested sampling, and uncertainties are calculated using the methods introduced in Chapters 3 and 4. Chapter 7 applies our Bayesian sparse reconstruction framework to artificial neural networks, where it allows the optimum network architecture to be determined by treating the number of nodes and hidden layers as parameters. We conclude by suggesting possible areas of future research in Chapter 8.
64

Estudo da viabilidade para introduzir na rotina testes de diagnóstico para infecção respiratória aguda / Feasibility study to introduce the routine diagnostic tests for acute respiratory infection

Teresa Maria Furlan 18 April 2016 (has links)
Para avaliar os benefícios da comunicação rápida ao clínico do diagnóstico de vírus respiratórios, foi analisado a viabilidade econômica de 2 testes, com o tempo de entrega de resultado em 2 horas para teste rápido e 48 horas para Biologia Molecular. As amostras coletadas foram processadas utilizando técnicas convencionais e os testes disponíveis no mercado local. Foram escolhidos dois testes rápidos pelo método de imunocromatografia para quatro parâmetros analíticos: Influenza A, Influenza H1N1, Influenza B e Vírus Sincicial Respiratório (RSV) e em Biologia Molecular um teste de RT-PCR multiplex com 25 patógenos entre vírus e bactérias. O tipo de amostra utilizada foi swab e lavado de nasofaringe. A população escolhida para o estudo foi paciente adulto, em tratamento de câncer, que necessita de uma resposta rápida já que a maioria se encontra com comprometimento do sistema imune por doença ou por tratamento. O estudo foi transversal, realizado entre os anos de 2012 e 2013, para avaliar a viabilidade econômica da introdução de testes de diagnóstico da infecção respiratória aguda de etiologia viral a partir de amostras de nasofaringe em pacientes com câncer atendidos no Centro de Atendimento de Oncologia Intercorrência (CAIO ), do Instituto do Câncer do Estado de São Paulo (ICESP), hospital público que atende exclusivamente Sistema Único de Saúde (SUS) e Hospital A.C. Camargo, que atende tanto a pacientes do SUS como da rede privada. O estudo incluiu 152 pacientes em tratamento para qualquer tipo de câncer, predominantemente do sexo feminino (81 mulheres e 70 homens) com idades entre 18-86 anos. Para participar do estudo o paciente era consultado e o critério para escolha do paciente foi ser portador de câncer, com história de febre (ainda que referida) acompanhada de tosse ou dor de garganta, tosse e sintomas respiratórios agudos, atendidos por protocolo padronizado que inclui avaliação na admissão, seguimento e manejo antimicrobiano. Para a avaliação econômica os pacientes foram classificados de acordo com o estado geral de saúde, se apresentavam bom estado de estado de saúde poderiam receber alta e faziam uso da medicação em casa evitando 5 dias de internação se recebessem algum resultado para Influenza ou RSV, no entanto os pacientes que apresentavam outro vírus, resultado negativo ou o estado geral era ruim permaneciam internados por 7 dias em observação e cuidados com medicação adequada. Foram realizadas análises econômicas em dois âmbitos: o sistema de saúde publico e o privado considerando o fator diminuição de dias de internação. A analise de Custo-benefício foi eficiente no Sistema privado mas inadequada para o SUS assim como, qualquer outra medida monetária já que os valores de reembolso do SUS estão defasados do custo de qualquer internação. A análise de Custo-efetividade que olha para outros fatores além do monetário foi efetiva nos dois sistemas que enfrentam falta de leitos além da condição de saúde do paciente de evitar a ingestão desnecessária de antibióticos, evitar os gastos do acompanhante, perda de dias de trabalho e estudo. Não houve correspondência de resultados dos testes rápidos com o multiplex de Biologia Molecular / To evaluate the benefits of the rapid communication of the respiratory viruses\' diagnosis to the doctor, the economic feasibility of two tests was analyzed, with the result delivery time within 2-hours for the rapid test and 48 hours for Molecular Biology. The samples were processed using conventional techniques and the available tests in the local market. Two rapid tests were selected by the immunochromatography method for four analytical parameters: Influenza A, Influenza A H1N1, Influenza B, and Respiratory Syncytial Virus (RSV) and in Molecular Biology a multiplex RT-PCR assay with 25 pathogens between viruses and bacteria. The type of sample used was swab and nasopharyngeal wash. The population chosen for the study was of adult patients undergoing cancer treatment, which requires a rapid response since most have a compromised immune system due to the disease or treatment. The study, conducted between 2012 and 2013, was cross-sectional to evaluate the economic feasibility of introducing diagnostic tests for acute respiratory infection of viral etiology from nasopharyngeal samples of patients with cancer attended at the Oncology Intercurrence Care Center (CAIO), at the Cancer Institute of the São Paulo State (ICESP), at public hospital that attends exclusively the Unified Health System (SUS) and at AC Camargo hospital, which attends SUS patients as well as the private health system. The study included 152 patients undergoing treatment for any type of cancer, predominantly female (81 women and 70 men) between 18 and 86 years. To participate in the study, the patients were consulted and the criteria for choosing a patient was to be a cancer patient with a history of fever (even if referred) accompanied by cough or sore throat, coughing and acute respiratory symptoms, attended by standardized protocol that includes an evaluation at the admission, tracking and antimicrobial management. For the economic evaluation, patients were classified according to the general health condition. If they were in a good health condition, they could receive medical discharge and make use of the medication at home avoiding five days of hospitalization when receiving a result for influenza or RSV. However, the patients with other viruses, negative results or with bad general condition remained hospitalized for seven days under observation and care with proper medication. Economic analyzes were carried out in two areas: the public health system and private health system considering the factor decreased length of hospital stay. The cost-benefit analysis was efficient in the private system but inadequate for the NHS as well as any other monetary measure since the SUS reimbursement values are too low when compared to the cost of any other hospital. The cost-effectiveness analysis that looks at other factors besides money was effective in both systems that were facing lack of beds in addition to the health condition of the patient to avoid unnecessary intake of antibiotics, avoid the costs of the accompanying person, loss of working and study days. There were no results correspondences of the rapid tests with the Molecular Biology multiplex
65

Treating gambling addiction : a psychological study in the South African context

Bulwer, Miranda 06 1900 (has links)
The objectives of this study were to provide a detailed biopsychosocial description of the characteristics of a sample of 100 individuals screened and referred by the National Responsible Gaming Programme helpline for their outpatient treatment programme over an eighteen month period, and, importantly, to measure the success of this specific treatment programme at set intervals, up to a one year follow-up period. While 80% of the sample did not relapse during the six-week treatment programme, the number of treatment seekers without any gambling relapses during each follow-up period declined, and those falling back into gambling increased as time went on. After one year 47% of treatment seekers managed not to revert back to gambling – total abstinence. A further 28% reported having relapsed once or twice or that their gambling was controlled. 25% of treatment seekers reported that they reverted back to gambling fulltime which leaves the success rate of the treatment at 75%. Treatment seekers reported an overall reduction in gambling participation, debt and expenditure and an overall improvement in social and vocational functioning. There is evidence in this study to support the perspective that pathological gambling is a multidimensional disorder and that certain sub-groups of gamblers have distinct gambling behaviour. / Psychology / M.Soc.Sc.
66

Difficulties in the comprehension and interpretation of a selection of graph types and subject-specific graphs displayed by senior undergraduate biochemistry students in a South African university

Van Tonder, André 11 1900 (has links)
A carefully constructed set of 16 graphical tasks related to key biochemistry concepts was designed and administered to a group of 82 students in their final year of B.Sc. study. The test mean score of 48,3% ( 12,1) was low and characterised by gender and ethnic differences. There was a moderate linear relationship between biochemistry grades obtained by the students over two years of study and their graphical literacy (r = 0,433). The majority of the students exhibited slope/height confusion and only seven students (8,5%) were able to answer the two items corresponding to Kimura‘s Level F, the most complex and difficult level of graphical literacy. Eye tracking data gave valuable insights into different strategies used by students while interpreting graphs and is a valuable tool for assessing graphical literacy. These findings confirmed other studies where researchers have found a widespread lack of graph comprehension among biological science students. / Institute of Science and Technology Education / M. Sc. (Science Education)
67

Estimating trade flows : case of South Africa and BRICs

Manzombi, Prisca 03 1900 (has links)
This study examines the fundamental determinants of bilateral trade flows between South Africa and BRIC countries. This is done by exploring the magnitude of exports among these countries. The Gravity model approach is used as the preferred theoretical framework in explaining and evaluating successfully the bilateral trade flows between South Africa and BRIC countries The empirical part of this study uses panel data methodology covering the time period 2000-2012 and incorporates the five BRICS economies in the sample. The results of the regressions are subject to panel diagnostic test procedures. The study reveals that, on the one hand, there are positive and significant relationships between South African export flows with the BRICs and distance, language dummy, the BRICs’ GDP, the BRICs’ openness and population in South Africa. On the other hand, GDP in South Africa, real exchange rate and time dummy are found to be negatively related to export flows. / Economics / M. Com. (Economics)
68

Evaluering van skoolbeginners met die oog op effektiewe aanvangsonderrig

Heckroodt, Annétia Sophia 06 1900 (has links)
Summaries in Afrikaans and English / Text in Afrikaans / With compulsory education in the New South· Africa, an increase in the number of school beginners can be expected, together with the probability of large gaps in their readiness for school. In £his study, materials have been developed together with a structure for the organisation of teaching_~!?.r trainers/subject advisers, teachers and pupils, to ensure effective education for school beginners. The "Battery for the Assessment of Bridging period Yields" (BABY) has been developed as a valid, realiable and usable school readiness battery of tests for teachers as unregistered test users. The Pre-Test for division into homogeneous ability groups is applied shortly after entrance to school. The Battery of Diagnostic Tests ensures continuous evaluation of pupils during the school readiness programme. The Post-Test is applied at the end of the first term. In this dynamic interaction between tester and pupil in an instruction-test-instruction cycle, the pupils' readiness to progress with formal instruction is continuously evaluated. / Met verpligte onderwys in die Nuwe Suid-Afrika, kan 'n toename in die getal swart skoolbeginners ve:wag word, asook dat daar in hulle skoolvoorbereiding groot leemtes kan voorkom. In die onderhawige studie is hulpmiddels en 'n struktuur vir onderwysorganisasie vir opleiers/vakadviseurs, onderwyseresse en leerlinge ontwikkel om aan skoolbeginners effektiewe onderwys te verseker. Die "Battery for the Assessment of Bridging period Yields" (BABY), 'n geldige, betroubare en bruikbare skoolgereedheidstoetsbattery vir onderwyseresse as ongeregistreerde toetsgebruikers, is ontwikkel. Die Voortoets vtr indeling in homogene bevoegdheidsgroepe word kort na skooltoetrede toegepas. Die Diagnostiese Toetsbattery verseker deurlopende evaluering van leerlinge gedurende die skoolgereedmakingsprogram. Die Natoets word aan die einde van die eerste kwartaal toegepas. In hierdie dinamiese interaksie tussen toetser en leerling in 'n onderrig-toets-onderrig siklus, word leerlinge se gereedheid om met formele onderrig voort te gaan, deurlopend geevalueer. / Psychology og Education / M. Ed. (Psychology of Education)
69

The development of CT urography for investigating haematuria

Cowan, Nigel Christopher January 2013 (has links)
This thesis addresses the three principal questions concerning the development of CT urography for investigating haematuria and each question is the subject of a separate chapter. The questions are: What is the reasoning behind using CT urography? What is the optimum diagnostic strategy using CT urography? What are the problems with using CT urography and how may solutions be provided? Haematuria can signify serious disease such as urinary tract stones, renal cell cancer, upper tract urothelial cancer (UTUC) and bladder cancer (BCa). CT urography is defined as contrast enhanced CT examination of kidneys, ureters and bladder. The technique used here includes unenhanced, nephrographic and excretory-phases for optimized diagnosis of stones, renal masses and urothelial cancer respectively. The reasoning behind using excretory-phase CT urography for investigating haematuria is based on results showing its high diagnostic accuracy for UTUC and BCa. Patients with haematuria are classified as low risk or high risk for UTUC and BCa, by a risk score, determined by the presence/absence of risk factors: age > 50 years, visible or nonvisible haematuria, history of smoking and occupational exposure. The optimum diagnostic strategy for patients at high risk for urothelial cancer, uses CT urography as a replacement test for ultrasonography and intravenous urography and as a triage test for flexible and rigid cystoscopy, resulting in earlier diagnosis and potentially improving prognosis. For patients at low risk, ultrasonography, unenhanced and nephrographic-phase CT urography are proposed as initial imaging tests. Problems with using CT urography include false positive results for UTUC, which are eliminated by retrograde ureteropyelography-guided biopsy, an innovative technique, for histopathological confirmation of diagnosis. Recommendations for the NHS and possible future developments are discussed. CT urography, including excretory-phase imaging, is recommended as the initial diagnostic imaging test before cystoscopy for patients with haematuria at high risk for urothelial cancer.
70

Evaluering van skoolbeginners met die oog op effektiewe aanvangsonderrig

Heckroodt, Annétia Sophia 06 1900 (has links)
Summaries in Afrikaans and English / Text in Afrikaans / With compulsory education in the New South· Africa, an increase in the number of school beginners can be expected, together with the probability of large gaps in their readiness for school. In £his study, materials have been developed together with a structure for the organisation of teaching_~!?.r trainers/subject advisers, teachers and pupils, to ensure effective education for school beginners. The "Battery for the Assessment of Bridging period Yields" (BABY) has been developed as a valid, realiable and usable school readiness battery of tests for teachers as unregistered test users. The Pre-Test for division into homogeneous ability groups is applied shortly after entrance to school. The Battery of Diagnostic Tests ensures continuous evaluation of pupils during the school readiness programme. The Post-Test is applied at the end of the first term. In this dynamic interaction between tester and pupil in an instruction-test-instruction cycle, the pupils' readiness to progress with formal instruction is continuously evaluated. / Met verpligte onderwys in die Nuwe Suid-Afrika, kan 'n toename in die getal swart skoolbeginners ve:wag word, asook dat daar in hulle skoolvoorbereiding groot leemtes kan voorkom. In die onderhawige studie is hulpmiddels en 'n struktuur vir onderwysorganisasie vir opleiers/vakadviseurs, onderwyseresse en leerlinge ontwikkel om aan skoolbeginners effektiewe onderwys te verseker. Die "Battery for the Assessment of Bridging period Yields" (BABY), 'n geldige, betroubare en bruikbare skoolgereedheidstoetsbattery vir onderwyseresse as ongeregistreerde toetsgebruikers, is ontwikkel. Die Voortoets vtr indeling in homogene bevoegdheidsgroepe word kort na skooltoetrede toegepas. Die Diagnostiese Toetsbattery verseker deurlopende evaluering van leerlinge gedurende die skoolgereedmakingsprogram. Die Natoets word aan die einde van die eerste kwartaal toegepas. In hierdie dinamiese interaksie tussen toetser en leerling in 'n onderrig-toets-onderrig siklus, word leerlinge se gereedheid om met formele onderrig voort te gaan, deurlopend geevalueer. / Psychology og Education / M. Ed. (Psychology of Education)

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