Дисертації з теми "Sample chain"

Sample average approximation (SAA) is a well-known solution methodology for traditional stochastic programs which are risk neutral in the sense that they consider optimization of expectation functionals. In this thesis we establish sample average approximation methods for two classes of non-traditional stochastic programs. The first class is that of stochastic min-max programs, i.e., min-max problems with expected value objectives, and the second class is that of expected value constrained stochastic programs. We specialize these SAA methods for risk-averse stochastic problems with a bi-criteria objective involving mean and mean absolute deviation, and those with constraints on conditional value-at-risk. For the proposed SAA methods, we prove that the results of the SAA problem converge exponentially fast to their counterparts for the true problem as the sample size increases. We also propose implementation schemes which return not only candidate solutions but also statistical upper and lower bound estimates on the optimal value of the true problem. We apply the proposed methods to solve portfolio selection and supply chain network design problems. Our computational results reflect good performance of the proposed SAA schemes. We also investigate the effect of various types of risk-averse stochastic programming models in controlling risk in these problems.

It is suggested to discriminate between different state space models for a given time series by means of a Bayesian approach which chooses the model that minimizes the expected loss. Practical implementation of this procedures requires a fully Bayesian analysis for both the state vector and the unknown hyperparameters which is carried out by Markov chain Monte Carlo methods. Application to some non-standard situations such as testing hypotheses on the boundary of the parameter space, discriminating non-nested models and discrimination of more than two models is discussed in detail. (author's abstract)
Series: Forschungsberichte / Institut für Statistik

This study develops and empirically tests a model of factors determining green supply chain management practices in organisations. Previous research on aspects of green supply chain management is dominated by anecdotal, sector specific studies that examine specific aspects of the supply chain, such as purchasing or logistics. Many argue this field is embryonic and lacking a structured integrative framework of research. This study addresses this gap by focussing on a whole supply chain approach that provides a synthesis of previous research to develop a model of green supply chain management. The data from a cross-sectoral survey of 149 members the Chartered Institute of Purchasing and Supply is used to test this model, using a variety of multivariate techniques. The model identifies environmental attitude as the primary determinant of green supply chain management practices, influenced to a lesser extent by external legislative factors. The influence of organisational contingencies on this model is also explored, and size identified as the only contingency that influences the relationships in this model. The dominant influence of environmental attitude suggests that within organisations there are internal factors, or individuals, that may push forward the green agenda, and those initiatives that focus on changing the environmental attitude/ culture of an organisation might be the most effective at improving environmental performance. This study suggests that factors previously identified as important within green supply chain management, such as supply chain or competitive pressures, are less influential than expected. However, future research should seek to compare the findings from this study with a larger, cross-sectoral sample that includes diverse organisations from different nations, sectors and levels of channel power.

The Rasch sampler is an efficient algorithm to sample binary matrices with given marginal sums. It is a Markov chain Monte Carlo (MCMC) algorithm. The program can handle matrices of up to 1024 rows and 64 columns. A special option allows to sample square matrices with given marginals and fixed main diagonal, a problem prominent in social network analysis. In all cases the stationary distribution is uniform. The user has control on the serial dependency. (authors' abstract)

One of the most significant changes in the evolution of modern business management is that organizations no longer compete as individual entities in the market, but as interlocking supply chains. Markets are no longer simply trading desks but dynamic ecosystems where people, organizations and the environment interact. Products and associated materials and resources are links that bridge supply chains from upstream (sourcing and manufacturing) to downstream (delivering and consuming). The lifecycle of a product plays a critical role in supply chains. Supply chains may be composed by, designed around, and modified for products. Product-related issues greatly impact supply chains. Existing studies have advanced product management and product lifecycle management literature through dimensions of product innovation, product growth, product line extensions, product efficiencies, and product acquisition. Product deletion, rationalization, or reduction research is limited but is a critical issue for many reasons. Sustainability is an important reason for this managerial decision. This study, grounded from multiple literature streams in both marketing and supply chain fields, identified relations and propositions to form a firm-level analysis on the role of supply chains in organizational product deletion decisions. Interviews, observational and archival data from international companies (i.e.: Australia, China, India, and Iran) contributed to the empirical support as case studies through a grounded theory approach. Bayesian analysis, an underused empirical analysis tool, was utilized to provide insights into this underdeveloped research stream; and its relationship to qualitative research enhances broader methodological understanding. Gibbs sampler and reversible jump Markov chain Monte Carlo (MCMC) simulation were used for Bayesian analysis based on collected data. The integrative findings are exploratory but provide insights for a number of research propositions.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering, 1994.
Includes bibliographical references (leaves 191-203).
by Richard Griggs Lewis II.
Ph.D.

Reliable biomarkers of axonal damage are urgently needed in neurological diseases. Neurofilaments (Nf) are specific structural elements of neurons composed of at least three subunits: Nf light chain (NfL), Nf medium and Nf heavy chain (NfH). This PhD aimed to characterise NfL levels and their correlation with clinical features in patients with neurological diseases with a different rate of progression and following and under different treatment regimes. An important aim was also to develop a bioassay for NfL measurements in blood. Cerebrospinal fluid (CSF) NfL levels discriminated patients with a clinically isolated syndrome (CIS) (p=0.001) or multiple sclerosis (MS) (p=0.035) from healthy controls more efficiently, and was more sensitive to change after natalizumab therapy (p<0.0001) than CSF NfH (p=0.002). Further, CSF NfL levels decreased in fingolimodtreated MS patients (p=0.001), but not in those receiving placebo (p=0.433). Based on these findings, a sensitive method for the detection of NfL in serum was developed and validated. Patients with neurological diseases had higher serum NfL values than controls. In acute spinal cord injury (SCI), serum NfL levels correlated with injury severity and long-term motor outcome, and Minocycline treatment was associated with decreased NfL levels in complete SCI patients compared to placebo. Finally, I found that serum NfL levels were higher in CIS patients than in healthy controls but did not predict conversion to clinically definite MS (CDMS). Independent predictors of CDMS were instead oligoclonal bands, number of T2 lesions and age at CIS. Lower 25-OHvitamin D levels were associated with CDMS in univariate analysis, but this was attenuated in the multivariate model. In conclusion, NfL proved to be an analytically stable protein which is an important prerequisite for biomarkers. The role of NfL quantification as a surrogate measure of neuroaxonal damage is corroborated by my findings and further supports the usefulness of NfL as a putative biomarker of axonal damage in various neurological diseases.

The No-U-Turn Sampler (NUTS) is a relatively new Markov chain Monte Carlo (MCMC) algorithm that avoids the random walk behavior that common MCMC algorithms such as Gibbs sampling or Metropolis Hastings usually exhibit. Given the fact that NUTS can efficiently explore the entire space of the target distribution, the sampler converges to high-dimensional target distributions more quickly than other MCMC algorithms and is hence less computational expensive. The focus of this study is on applying NUTS to one of the complex IRT models, specifically the two-parameter mixture IRT (Mix2PL) model, and further to examine its performance in estimating model parameters when sample size, test length, and number of latent classes are manipulated. The results indicate that overall, NUTS performs well in recovering model parameters. However, the recovery of the class membership of individual persons is not satisfactory for the three-class conditions. Also, the results indicate that WAIC performs better than LOO in recovering the number of latent classes, in terms of the proportion of the time the correct model was selected as the best fitting model. However, when the effective number of parameters was also considered in selecting the best fitting model, both fully Bayesian fit indices perform equally well. In addition, the results suggest that when multiple latent classes exist, using either fully Bayesian fit indices (WAIC or LOO) would not select the conventional IRT model. On the other hand, when all examinees came from a single unified population, fitting MixIRT models using NUTS causes problems in convergence.

Background The lack of an effective diagnostic tool for Carrion’s disease leads to misdiagnosis, wrong treatments and perpetuation of asymptomatic carriers living in endemic areas. Conventional PCR approaches have been reported as a diagnostic technique. However, the detection limit of these techniques is not clear as well as if its usefulness in low bacteriemia cases. The aim of this study was to evaluate the detection limit of 3 PCR approaches. Methodology/Principal Findings We determined the detection limit of 3 different PCR approaches: Bartonella-specific 16S rRNA, fla and its genes. We also evaluated the viability of dry blood spots to be used as a sample transport system. Our results show that 16S rRNA PCR is the approach with a lowest detection limit, 5 CFU/μL, and thus, the best diagnostic PCR tool studied. Dry blood spots diminish the sensitivity of the assay. Methodology/Principal Findings We determined the detection limit of 3 different PCR approaches: Bartonella-specific 16S rRNA, fla and its genes. We also evaluated the viability of dry blood spots to be used as a sample transport system. Our results show that 16S rRNA PCR is the approach with a lowest detection limit, 5 CFU/μL, and thus, the best diagnostic PCR tool studied. Dry blood spots diminish the sensitivity of the assay. Conclusions/Significance From the tested PCRs, the 16S rRNA PCR-approach is the best to be used in the direct blood detection of acute cases of Carrion’s disease. However its use in samples from dry blood spots results in easier management of transport samples in rural areas, a slight decrease in the sensitivity was observed. The usefulness to detect by PCR the presence of low-bacteriemic or asymptomatic carriers is doubtful, showing the need to search for new more sensible techniques.

In Virginia, over one million households rely on private water supplies (e.g. well, spring, cistern). Previous literature acknowledges bacterial contamination in private water supplies as a significant public health concern in the United States. The present study tested private wells and springs in 20 Virginia counties for total coliforms (TC) and E. coli (EC) along with a suite of chemical contaminants. Sample collection was organized by the Virginia Household Water Quality Program (VAHWQP), a Virginia Cooperative Extension effort managed by faculty in the Biological Systems Engineering Department. Microbial and chemical source tracking were used to identify possible sources of contamination. A logistic regression was employed to investigate potential correlations between TC contamination and chemical parameters (e.g. NO3-, turbidity) as well as homeowner provided survey data describing system characteristics and perceived water quality. TC and EC contamination were quantified via the Colilert (www.idexx.com) defined substrate method for most probable number (MPN) of EC and TC per 100 mL of water. Of the 538 samples collected, 41% (n=221) were positive for TC and 10% (n=53) for EC. Chemical parameters were not statistically predictive of microbial contamination. Well depth, water treatment, and farm location proximate to the water supply were factors in a regression model that predicted presence/absence of TC with 74% accuracy. Microbial and chemical source tracking techniques (Polymerase Chain Reaction (PCR) and fluorometry, respectively) identified 4 of 26 samples as likely contaminated with human wastewater. Application of these source-tracking analyses on a larger scale will prove useful in defining remediation strategies.
Master of Science

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A presente pesquisa teve como objetivo analisar a atuação acadêmica do professor Chaim Samuel Hönig (1926 - ) para o desenvolvimento da Matemática no Brasil. Para tanto, investigamos sua trajetória acadêmica privilegiando suas principais obras, sua Descendência Científica, os matemáticos que o influenciaram e suas contribuições para a criação e o desenvolvimento da Comunidade Matemática brasileira. O professor Chaim graduou-se em Matemática e Física pela Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo - USP, nesta Universidade doutorou-se, tornou-se professor Livre Docente e professor Titular. Trabalhou no departamento de Matemática da USP, inicialmente na FFCL e, posteriormente, no IME, por mais de quatro décadas, lecionando na graduação e na pós-graduação. Na referida universidade criou um Seminário destinado a discussões relativas à pesquisa em Matemática e, ainda, assumiu importantes atividades administrativas. Realizou investigações matemáticas em várias áreas, das quais destacamos a Topologia (Topologia Geral) e a Análise (Equações Diferenciais e Análise funcional). Nestas áreas, foi influenciado pelos matemáticos A. Groethendieck (1928 - ), Leopoldo Nachbin (1922 - 1993), L. Schwartz (1915 - 2002) e Cândido da Lima Silva Dias (1913 - 1998). Dentre suas principais produções acadêmicas destacamos três livros da área de Análise amplamente utilizados para a formação de matemáticos em território nacional. Sua Descendência Científica é constituída de mais de 70 acadêmicos que atuam e/ou atuaram em importantes instituições de ensino superior no Brasil e realizam e/ou realizaram investigações nas áreas de Educação Matemática, História da Matemática e, especialmente, Análise. O professor Chaim...
This research aims at analyzing Professor Chaim S. Hõnig's (1926 - ) contributions to the development of Brazilian Mathematics. In order to achieve this goal, his academic career is investigated, with emphasis to his main works, his Scientific Lineage, the mathematicians who have influenced him, and his contributions to the creation and development of the Brazilian Community of Mathematics. Professor Hõnig obtained a degree in Mathematics and Physics from the Faculty of Philosophy, Sciences and Letters of the University of São Paulo - USP, where he also carried out his doctoral studies, became an Associate Professor, and a Full Professor. He worked in the Mathematics Department at USP, which was first located at the FFCL (Faculty of Philosophy, Sciences and Letters) and later at IME (Mathematics and Statistics Institute), for over four decades, teaching at both undergraduate and graduate levels. He created, at the University, a seminar dedicated to discussions related to the research in Mathematics and was also responsible for important administrative tasks. He carried out mathematical investigations in various fields, among which Topology (General Topology) and Analysis (Differential Equations and Functional Analysis) stand out. In these areas, he was influenced by the mathematicians A. Groethendieck (1928 -), Leopolodo Nachbin (1922 - 1993), L. Schwartz (1915 - 2002) and Candido da Lima Silva Dias (1913 - 1998). Among his main academic works, three books in the Analysis field, which are broadly used in the teaching of mathematicians in Brazil, are most noteworthy. His Scientific Lineage is formed by more than 70 scholars who either work or have worked at important higher education institutions in Brazil and have carried out investigations in the areas of Mathematics Education, the History of Mathematics... (Complete abstract click electronic access below)

Orientador: Sergio Roberto Nobre
Banca: Rosa Lúcia Svezut Baroni
Banca: Carlos Roberto Moraes
Banca: Iran Abreu Mendes
Banca: Romélia Mara Alves Souto
Resumo: A presente pesquisa teve como objetivo analisar a atuação acadêmica do professor Chaim Samuel Hönig (1926 - ) para o desenvolvimento da Matemática no Brasil. Para tanto, investigamos sua trajetória acadêmica privilegiando suas principais obras, sua Descendência Científica, os matemáticos que o influenciaram e suas contribuições para a criação e o desenvolvimento da Comunidade Matemática brasileira. O professor Chaim graduou-se em Matemática e Física pela Faculdade de Filosofia, Ciências e Letras da Universidade de São Paulo - USP, nesta Universidade doutorou-se, tornou-se professor Livre Docente e professor Titular. Trabalhou no departamento de Matemática da USP, inicialmente na FFCL e, posteriormente, no IME, por mais de quatro décadas, lecionando na graduação e na pós-graduação. Na referida universidade criou um Seminário destinado a discussões relativas à pesquisa em Matemática e, ainda, assumiu importantes atividades administrativas. Realizou investigações matemáticas em várias áreas, das quais destacamos a Topologia (Topologia Geral) e a Análise (Equações Diferenciais e Análise funcional). Nestas áreas, foi influenciado pelos matemáticos A. Groethendieck (1928 - ), Leopoldo Nachbin (1922 - 1993), L. Schwartz (1915 - 2002) e Cândido da Lima Silva Dias (1913 - 1998). Dentre suas principais produções acadêmicas destacamos três livros da área de Análise amplamente utilizados para a formação de matemáticos em território nacional. Sua Descendência Científica é constituída de mais de 70 acadêmicos que atuam e/ou atuaram em importantes instituições de ensino superior no Brasil e realizam e/ou realizaram investigações nas áreas de Educação Matemática, História da Matemática e, especialmente, Análise. O professor Chaim... (Resumo completo, clicar acesso eletrônico abaixo)
Abstract: This research aims at analyzing Professor Chaim S. Hõnig's (1926 - ) contributions to the development of Brazilian Mathematics. In order to achieve this goal, his academic career is investigated, with emphasis to his main works, his Scientific Lineage, the mathematicians who have influenced him, and his contributions to the creation and development of the Brazilian Community of Mathematics. Professor Hõnig obtained a degree in Mathematics and Physics from the Faculty of Philosophy, Sciences and Letters of the University of São Paulo - USP, where he also carried out his doctoral studies, became an Associate Professor, and a Full Professor. He worked in the Mathematics Department at USP, which was first located at the FFCL (Faculty of Philosophy, Sciences and Letters) and later at IME (Mathematics and Statistics Institute), for over four decades, teaching at both undergraduate and graduate levels. He created, at the University, a seminar dedicated to discussions related to the research in Mathematics and was also responsible for important administrative tasks. He carried out mathematical investigations in various fields, among which Topology (General Topology) and Analysis (Differential Equations and Functional Analysis) stand out. In these areas, he was influenced by the mathematicians A. Groethendieck (1928 -), Leopolodo Nachbin (1922 - 1993), L. Schwartz (1915 - 2002) and Candido da Lima Silva Dias (1913 - 1998). Among his main academic works, three books in the Analysis field, which are broadly used in the teaching of mathematicians in Brazil, are most noteworthy. His Scientific Lineage is formed by more than 70 scholars who either work or have worked at important higher education institutions in Brazil and have carried out investigations in the areas of Mathematics Education, the History of Mathematics... (Complete abstract click electronic access below)
Doutor

Thesis (Ph. D.)--Michigan State University. Dept. of Crops and Soil Sciences, 2008.
Title from PDF t.p. (viewed Aug. 18, 2009). Includes bibliographical references (p. 147-171). Also issued in print.

The analysis of big data is of great interest today, and this comes with challenges of improving precision and efficiency in estimation and prediction. We study binary data with covariates from numerous small areas, where direct estimation is not reliable, and there is a need to borrow strength from the ensemble. This is generally done using Bayesian logistic regression, but because there are numerous small areas, the exact computation for the logistic regression model becomes challenging. Therefore, we develop an integrated multivariate normal approximation (IMNA) method for binary data with covariates within the Bayesian paradigm, and this procedure is assisted by the empirical logistic transform. Our main goal is to provide the theory of IMNA and to show that it is many times faster than the exact logistic regression method with almost the same accuracy. We apply the IMNA method to the health status binary data (excellent health or otherwise) from the Nepal Living Standards Survey with more than 60,000 households (small areas). We estimate the proportion of Nepalese in excellent health condition for each household. For these data IMNA gives estimates of the household proportions as precise as those from the logistic regression model and it is more than fifty times faster (20 seconds versus 1,066 seconds), and clearly this gain is transferable to bigger data problems.

iv The present work describes the evaluation of the value of polymerase chain reaction in diagnosis of pneumonia caused by the most common three bacterial pathogens
Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis from sputum of patients with community acquired pneumonia admitted to The Department of Pulmonary Diseases of Gulhane Military Medical Academy. In this study, 107 sputa from 142 patients with suspected community acquired pneumonia were used to survey the causative agents. Identification of the pathogens was performed by sputum Gram stain and conventional microbiological methods. Polymerase chain reaction was performed to investigate the presence of S.pneumoniae, H.influenzae, and M.catarrhalis for the same sputum samples as well. PCR products were processed by electrophoresis on 2% agarose gels with visualization of the amplicon with ethidium bromide and UV illumination. The 33 of 107 samples were positive in cultures and 67 in PCR. S.pneumoniae (48.5%) was the most common etiologic agent as to PCR analysis. The incidences of H.influenzae and M.catarrhalis were determined as 18.6%, and 4.7% respectively. The incidence of S.pneumoniae in patients with CAP and control group individuals were almost the same. The sputum PCR positives were higher than those reported carriage rates for these three microorganisms. 9 of 107 patients with PCR-positive had evidence of infection with pathogens other than S.pneumoniae. The results indicated that some of the PCR results were false positive due to oropharyngeal contamination. PCR testing of sputum samples for diagnosing pneumococcal pneumonia is unable to distinguish colonization from infection in some circumstances. To distinguish the colonization from infection, sputum Gram stain should be applied to the sputum specimens. Because of being faster and easier, PCR looks like becoming more reliable technique by the using of valid specimens from patients with community-acquired pneumonia if supported by quantitative techniques.

Background: Tuberculosis (TB) is an infectious disease caused by Mycobacterium tuberculosis (MTB) and is a major global health problem with an annual mortality of 1.8 million people and being the cause of ill-health among many more millions. Rapid and accurate diagnosis of TB is key to managing the disease, its control and transmission. Many established diagnostic methods suffer from low sensitivity or delays in getting results and are inadequate for rapid detection of MTB in pulmonary and extra-pulmonary clinical samples. This study examined whether real-time polymerase chain reaction (RT-PCR) assay, with a 2 h turn-a-round time, would prove effective for routine detection of MTB in clinical microbiology laboratories. Methods: A systematic literature search was performed for publications in any language (January 1995–November 2016) on the detection of MTB in pathological samples by RT-PCR assay. The following databases were used: MEDLINE via PUBMED, EMBASE, BIOSIS Citation Index, Web of Science, SCOPUS, ISI Web of Knowledge and Cochrane Infectious Diseases Group Specialised Register, grey literature and the World Health Organization and Centers for Disease Control and Prevention websites. Studies were only included if they met set inclusion criteria. Generated pooled summary estimates (95% CIs) were calculated for sensitivity and specificity by use of random-effects meta-analysis when four or more studies were available. For meta-analysis, the bivariate model was used because it takes into account potential threshold effects and the correlation between sensitivity and specificity. It also allows addition of covariates for investigation of potential sources of heterogeneity. RevMan 5.3 and Meta-Disc software packages were used. Results: Forty-six studies out of 6,706 citations identified met the inclusion criteria, providing information from 21 countries with high, moderate and low prevalence of TB. Studies included patients with infections identified in primary, secondary and tertiary healthcare settings. There were a total of 35,380 samples: 28,406 from pulmonary TB (PTB) and 6974 from extra-pulmonary (EPTB). Summary estimates for PTB (31 studies) were: sensitivity 0.82; 95% CI, 0.81–0.83; specificity 0.99; 95% CI, 0.99–0.99; positive likelihood ratio 43.00 (28.23–64.81); negative likelihood ratio 0.16 (0.12–0.20), diagnostic odds ratio 324.26 (95% CI 189.08–556.09) and area under curve (AUC) 0.99. Summary estimates for EPTB (25 studies) were: sensitivity 0.70, 95% CI, 0.67–0.72; specificity 0.99, 95% CI, 0.99–0.99; positive likelihood ratio 29.82 (17.86–49.78); negative likelihood ratio 0.33 (0.26–0.42); diagnostic odds ratio 125.20 (95% CI 65.75–238.36) and AUC 0.96. Summary estimates for subgroup analyses by RT-PCR assay type were: with CobasTaqMan as the RTPCR assay (17 studies): sensitivity 0.78, 95% CI, 0.76–0.80; specificity 0.99, 95% CI, 0.99–0.99 and AUC 0.98. With Roche Light cycler as the RT-PCR assay (7 studies): sensitivity 0.85, 95% CI, 0.80–0.88; specificity 0.99, 95% CI, 0.98–0.99 and AUC 0.97. With Cepheid & other types of RT-PCR assay (22 studies): sensitivity 0.78, 95% CI, 0.77–0.80; specificity 0.99, 95% CI, 0.99–0.99 and AUC 0.99. Summary estimates for subgroup analyses by RT-PCR assay target sequence genes were: with IS6110 as the RT-PCR assay target sequence gene (22 studies): sensitivity 0.79, 0.77–0.81, specificity 0.98, 0.98–0.98 and AUC 0.99. With 16SRNA as the RTPCR assay target sequence gene (7 studies): sensitivity 0.69, 0.66–0.71; specificity 0.99, 0.99–0.99 and AUC 0.97. With other genes (17 studies): sensitivity 0.82, 0.80–0.84; specificity 0.99, 0.99–0.99 and AUC 0.98. Summary estimates for subgroup analyses by reference tests were: with solid and liquid media combined (25 studies): sensitivity 0.77, 95% CI, 0.76–0.79; specificity 0.99, 95% CI, 0.99–0.99 and AUC 0.99. With solid media alone (13 studies): sensitivity 0.80, 95% CI, 0.77–0.82; specificity 0.96, 95% CI, 0.96–0.97 and AUC 0.98. With liquid media alone (6 studies): sensitivity 0.81, 95% CI, 0.75–0.86; specificity 0.99, 95% CI, 0.99–1.00 and AUC 0.94. Conclusions: RT-PCR assay demonstrated a high degree of sensitivity for PTB and good sensitivity for EPTB. It indicated a high degree of specificity for ruling in TB infection from sampling regimes. This was acceptable, but may suggest it as a rule-out add-on diagnostic test. RT-PCR assay’s high degree of sensitivity in pulmonary samples and rapidity of detection of TB is an important factor in achieving effective global control and for patient management in terms of initiating early and appropriate anti-tubercular therapy.

Quality oriented management systems and methods have become the dominant business and governance paradigm. From this perspective, satisfying customers’ expectations by supplying reliable, good quality products and services is the key factor for an organization and even government. During recent decades, Statistical Quality Control (SQC) methods have been developed as the technical core of quality management and continuous improvement philosophy and now are being applied widely to improve the quality of products and services in industrial and business sectors. Recently SQC tools, in particular quality control charts, have been used in healthcare surveillance. In some cases, these tools have been modified and developed to better suit the health sector characteristics and needs. It seems that some of the work in the healthcare area has evolved independently of the development of industrial statistical process control methods. Therefore analysing and comparing paradigms and the characteristics of quality control charts and techniques across the different sectors presents some opportunities for transferring knowledge and future development in each sectors. Meanwhile considering capabilities of Bayesian approach particularly Bayesian hierarchical models and computational techniques in which all uncertainty are expressed as a structure of probability, facilitates decision making and cost-effectiveness analyses. Therefore, this research investigates the use of quality improvement cycle in a health vii setting using clinical data from a hospital. The need of clinical data for monitoring purposes is investigated in two aspects. A framework and appropriate tools from the industrial context are proposed and applied to evaluate and improve data quality in available datasets and data flow; then a data capturing algorithm using Bayesian decision making methods is developed to determine economical sample size for statistical analyses within the quality improvement cycle. Following ensuring clinical data quality, some characteristics of control charts in the health context including the necessity of monitoring attribute data and correlated quality characteristics are considered. To this end, multivariate control charts from an industrial context are adapted to monitor radiation delivered to patients undergoing diagnostic coronary angiogram and various risk-adjusted control charts are constructed and investigated in monitoring binary outcomes of clinical interventions as well as postintervention survival time. Meanwhile, adoption of a Bayesian approach is proposed as a new framework in estimation of change point following control chart’s signal. This estimate aims to facilitate root causes efforts in quality improvement cycle since it cuts the search for the potential causes of detected changes to a tighter time-frame prior to the signal. This approach enables us to obtain highly informative estimates for change point parameters since probability distribution based results are obtained. Using Bayesian hierarchical models and Markov chain Monte Carlo computational methods, Bayesian estimators of the time and the magnitude of various change scenarios including step change, linear trend and multiple change in a Poisson process are developed and investigated. The benefits of change point investigation is revisited and promoted in monitoring hospital outcomes where the developed Bayesian estimator reports the true time of the shifts, compared to priori known causes, detected by control charts in monitoring rate of excess usage of blood products and major adverse events during and after cardiac surgery in a local hospital. The development of the Bayesian change point estimators are then followed in a healthcare surveillances for processes in which pre-intervention characteristics of patients are viii affecting the outcomes. In this setting, at first, the Bayesian estimator is extended to capture the patient mix, covariates, through risk models underlying risk-adjusted control charts. Variations of the estimator are developed to estimate the true time of step changes and linear trends in odds ratio of intensive care unit outcomes in a local hospital. Secondly, the Bayesian estimator is extended to identify the time of a shift in mean survival time after a clinical intervention which is being monitored by riskadjusted survival time control charts. In this context, the survival time after a clinical intervention is also affected by patient mix and the survival function is constructed using survival prediction model. The simulation study undertaken in each research component and obtained results highly recommend the developed Bayesian estimators as a strong alternative in change point estimation within quality improvement cycle in healthcare surveillances as well as industrial and business contexts. The superiority of the proposed Bayesian framework and estimators are enhanced when probability quantification, flexibility and generalizability of the developed model are also considered. The empirical results and simulations indicate that the Bayesian estimators are a strong alternative in change point estimation within quality improvement cycle in healthcare surveillances. The superiority of the proposed Bayesian framework and estimators are enhanced when probability quantification, flexibility and generalizability of the developed model are also considered. The advantages of the Bayesian approach seen in general context of quality control may also be extended in the industrial and business domains where quality monitoring was initially developed.

This study was carried out to determine the frequency and levels of occurrence of legionellae in groundwaters from a variety of sources in U.S. and Canada. A limited number of water samples from cooling towers were also tested because municipally treated waters are considered to be the main sources of Legionella in artificial habitats such as cooling towers, air conditioners, whirlpools, hot tubs and plumbing systems (Krammer and Ford, 1994). Conventional procedures, including cultivation and polymerase chain reaction (PCR), were used to determine the presence of Legionella spp. in the water and biofilm samples during this study. A novel approach, using immuno-magnetic separation (IMS) in combination with cultivation or PCR, was also explored as an improved and rapid detection method for Legionella over conventional procedures. Because the IMS technique was continually being improved over the course of this study, all the samples received did not undergo the same procedure. (Abstract shortened by UMI.)

We have modified a technique which uses a single pair of primer sets directed against homologous but distinct genes on the X and Y chromosomes, all of which are coamplified in the same reaction tube with trace amounts of radioactivity. The resulting bands are equal in length, yet distinguishable by restriction enzyme sites generating two independent bands, a 364 bp X-specific band and a 280 bp Y-specific band. A standard curve was generated to show the linear relationship between X/Y ratio average vs. %Y or %X chromosomal content. Of the 51 purified amniocyte DNA samples analyzed, 16 samples showed evidence of high % X contamination while 2 samples demonstrated higher % Y than the expected 50% X and 50% Y chromosomal content. With regards to the 25 processed sperm samples analyzed, X-sperm enrichment was evident when compared to the primary sex ratio whereas Y-sperm was enriched when we compared before and after selection samples.

The transmission of enteric viruses by food, food products and water remains a wellrecognised, largely underestimated widespread public health problem. Outbreaks of gastroenteritis and hepatitis A due to the consumption of contaminated berry fruits have become a growing phenomenon worldwide. Contamination of fresh produce and other minimally processed foods can be attributed to pre- and post-harvest irrigation and washing water and food handlers. The prevention of such outbreaks relies on the optimisation of adequate methods for the recovery and detection of enteric viruses from food matrices and irrigation water. The aim of this study was to develop and apply optimised multiplex real-time reverse transcriptase-polymerase chain reaction (rt RT-PCR) assays for the detection of selected enteric viruses on berry fruits and in paired associated irrigation waters. In this study quality control measures were implemented by the development and optimisation of an internal amplification control (IAC) for norovirus (NoV) GII to monitor for the success of the amplification process. Mengovirus was used as a process control to validate the recovery and nucleic acid extraction of selected enteric viruses from strawberries and in associated irrigation waters. Three multiplex rt RT-PCR assays for the detection of NoV GI, NoV GII, sapovirus , hepatitis A virus, human astrovirus, human rotavirus and mengovirus were optimised with the IAC. Blackberries and strawberries were used to assess the efficiency of three nucleic acid extraction kits with the most efficient used in further investigations. Three elution buffers based on protein concentration, pH, Tris and elution period were assessed for the recovery of the viruses from the berry fruits. The pH more so than the protein concentration proved to be more effective in the recovery of the selected enteric viruses from the strawberries with no analytical significant differences noted for the two 3% glycine-beef extract (GBE) buffers assessed, irrespective of the parameters considered. During the period September 2010 to August 2011, strawberries and associated irrigation water were collected from which NoV GII, NoV GI and HAV could be recovered using a 3% tris-GBE pH 9.5 elution buffer and a glass-wool absorption elution method, respectively, and detected using optimised singleplex rt RT-PCR assays. The irrigation water samples together with eight surface and three groundwater samples collected from the Limpopo area was retested using the optimised multiplex rt RT-PCR assays. The multiplex rt RT-PCR assays proved to be more efficient in the detection of NoVs than the commercial environmental rt RT-PCR assays with lower detection efficiencies noted for HAV. Commercially obtained strawberries were dipped in polluted surface water, the viruses recovered from both and detected using the optimised multiplex rt RT-PCR assays resulted in the detection of similar viruses on both the strawberries and polluted irrigation water. Norovirus GII.7 and swine NoV GII.18 were identified on the strawberries and in the associated irrigation water, respectively. This is the first report of swine NoVs in South Africa, and begs the question as to the possibility of zoonotic NoV infection. This link between the viruses detected on the surface of the strawberries and in the irrigation water could not be confirmed by typing data. From this study, a functional AC was developed and used in the development and optimisation of three multiplex rt RT-PCR assays which made the gathering of new data of the role of irrigation water as a source of contamination of irrigated berry fruits in SA possible.
Dissertation (MSc)--University of Pretoria, 2013.
Medical Virology
MSc
Unrestricted

Thesis (Ph. D.)--Ohio State University, 2005.
Title from first page of PDF file. Document formatted into pages; contains xiii, 108 p.; also includes graphics. Includes bibliographical references (p. 104-108). Available online via OhioLINK's ETD Center

Item response theory (IRT) uses a family of statistical models for estimating stable characteristics of items and examinees and defining how these characteristics interact in describing item and test performance. With a focus on the three-parameter logistic IRT (Birnbaum, 1968; Lord, 1980) model, the current study examines the accuracy and variability of the item parameter estimates from the marginal maximum a posteriori estimation via an expectation-maximization algorithm (MMAP/EM) and the Markov chain Monte Carlo Gibbs sampling (MCMC/GS) approach. In the study, the various factors which have an impact on the accuracy and variability of the item parameter estimates are discussed, and then further evaluated through a large scale simulation. The factors of interest include the composition and length of tests, the distribution of underlying latent traits, the size of samples, and the prior distributions of discrimination, difficulty, and pseudo-guessing parameters. The results of the two estimation methods are compared to determine the lower limit--in terms of test length, sample size, test characteristics, and prior distributions of item parameters--at which the methods can satisfactorily recover item parameters and efficiently function in reality. For practitioners, the results help to define limits on the appropriate use of the BILOG-MG (which implements MMAP/EM) and also, to assist in deciding the utility of OpenBUGS (which carries out MCMC/GS) for item parameter estimation in practice.

Perfect slice sampling is a method to turn Markov Chain Monte Carlo (MCMC) samplers into exact generators for independent random variates. The originally proposed method is rather slow and thus several improvements have been suggested. However, two of them are erroneous. In this article we give a short introduction to perfect slice sampling, point out incorrect methods, and give a new improved version of the original algorithm. (author's abstract)
Series: Preprint Series / Department of Applied Statistics and Data Processing

Les méthodes de Monte Carlo par chaines de Markov MCMC sont des outils mathématiques utilisés pour simuler des mesures de probabilités π définies sur des espaces de grandes dimensions. Une des questions les plus importantes dans ce contexte est de savoir à quelle vitesse converge la chaine de Markov P vers la mesure invariante π. Pour mesurer la vitesse de convergence de la chaine de Markov P vers sa mesure invariante π nous utilisons la distance de la variation totale. Il est bien connu que la vitesse de convergence d’une chaine de Markov réversible P dépend de la deuxième plus grande valeur propre en valeur absolue de la matrice P notée β!. Une partie importante dans l’estimation de β! consiste à estimer la deuxième plus grande valeur propre de la matrice P, qui est notée β1. Diaconis et Stroock (1991) ont introduit une méthode basée sur l’inégalité de Poincaré pour estimer β1 pour le cas général des chaines de Markov réversibles avec un nombre fini d'état. Dans cette thèse, nous utilisons la méthode de Shiu et Chen (2015) pour étudier le cas de l'algorithme de l'échantillonneur de Gibbs pour le modèle d'Ising unidimensionnel avec trois états ou plus appelé aussi modèle de Potts. Puis, nous généralisons le résultat de Shiu et Chen au cas du modèle d’Ising deux- dimensionnel avec deux états. Les résultats obtenus minorent ceux introduits par Ingrassia (1994). Puis nous avons pensé à perturber l'échantillonneur de Gibbs afin d’améliorer sa vitesse de convergence vers l'équilibre
Monte Carlo Markov chain methods MCMC are mathematical tools used to simulate probability measures π defined on state spaces of high dimensions. The speed of convergence of this Markov chain X to its invariant state π is a natural question to study in this context.To measure the convergence rate of a Markov chain we use the total variation distance. It is well known that the convergence rate of a reversible Markov chain depends on its second largest eigenvalue in absolute value denoted by β!. An important part in the estimation of β! is the estimation of the second largest eigenvalue which is denoted by β1.Diaconis and Stroock (1991) introduced a method based on Poincaré inequality to obtain a bound for β1 for general finite state reversible Markov chains.In this thesis we use the Chen and Shiu approach to study the case of the Gibbs sampler for the 1−D Ising model with three and more states which is also called Potts model. Then, we generalize the result of Shiu and Chen (2015) to the case of the 2−D Ising model with two states.The results we obtain improve the ones obtained by Ingrassia (1994). Then, we introduce some method to disrupt the Gibbs sampler in order to improve its convergence rate to equilibrium

Cette thèse se décompose en deux parties. Dans un premier temps nous nous intéressons à la sélection bayésienne de variables dans un modèle probit mixte.L'objectif est de développer une méthode pour sélectionner quelques variables pertinentes parmi plusieurs dizaines de milliers tout en prenant en compte le design d'une étude, et en particulier le fait que plusieurs jeux de données soient fusionnés. Le modèle de régression probit mixte utilisé fait partie d'un modèle bayésien hiérarchique plus large et le jeu de données est considéré comme un effet aléatoire. Cette méthode est une extension de la méthode de Lee et al. (2003). La première étape consiste à spécifier le modèle ainsi que les distributions a priori, avec notamment l'utilisation de l'a priori conventionnel de Zellner (g-prior) pour le vecteur des coefficients associé aux effets fixes (Zellner, 1986). Dans une seconde étape, nous utilisons un algorithme Metropolis-within-Gibbs couplé à la grouping (ou blocking) technique de Liu (1994) afin de surmonter certaines difficultés d'échantillonnage. Ce choix a des avantages théoriques et computationnels. La méthode développée est appliquée à des jeux de données microarray sur le cancer du sein. Cependant elle a une limite : la matrice de covariance utilisée dans le g-prior doit nécessairement être inversible. Or il y a deux cas pour lesquels cette matrice est singulière : lorsque le nombre de variables sélectionnées dépasse le nombre d'observations, ou lorsque des variables sont combinaisons linéaires d'autres variables. Nous proposons donc une modification de l'a priori de Zellner en y introduisant un paramètre de type ridge, ainsi qu'une manière de choisir les hyper-paramètres associés. L'a priori obtenu est un compromis entre le g-prior classique et l'a priori supposant l'indépendance des coefficients de régression, et se rapproche d'un a priori précédemment proposé par Gupta et Ibrahim (2007).Dans une seconde partie nous développons deux nouvelles méthodes MCMC basées sur des populations de chaînes. Dans le cas de modèles complexes ayant de nombreux paramètres, mais où la vraisemblance des données peut se calculer, l'algorithme Equi-Energy Sampler (EES) introduit par Kou et al. (2006) est apparemment plus efficace que l'algorithme classique du Parallel Tempering (PT) introduit par Geyer (1991). Cependant, il est difficile d'utilisation lorsqu'il est couplé avec un échantillonneur de Gibbs, et nécessite un stockage important de valeurs. Nous proposons un algorithme combinant le PT avec le principe d'échanges entre chaînes ayant des niveaux d'énergie similaires dans le même esprit que l'EES. Cette adaptation appelée Parallel Tempering with Equi-Energy Moves (PTEEM) conserve l'idée originale qui fait la force de l'algorithme EES tout en assurant de bonnes propriétés théoriques et une utilisation facile avec un échantillonneur de Gibbs.Enfin, dans certains cas complexes l'inférence peut être difficile car le calcul de la vraisemblance des données s'avère trop coûteux, voire impossible. De nombreuses méthodes sans vraisemblance ont été développées. Par analogie avec le Parallel Tempering, nous proposons une méthode appelée ABC-Parallel Tempering, basée sur la théorie des MCMC, utilisant une population de chaînes et permettant des échanges entre elles
This thesis is divided into two main parts. In the first part, we propose a Bayesian variable selection method for probit mixed models. The objective is to select few relevant variables among tens of thousands while taking into account the design of a study, and in particular the fact that several datasets are merged together. The probit mixed model used is considered as part of a larger hierarchical Bayesian model, and the dataset is introduced as a random effect. The proposed method extends a work of Lee et al. (2003). The first step is to specify the model and prior distributions. In particular, we use the g-prior of Zellner (1986) for the fixed regression coefficients. In a second step, we use a Metropolis-within-Gibbs algorithm combined with the grouping (or blocking) technique of Liu (1994). This choice has both theoritical and practical advantages. The method developed is applied to merged microarray datasets of patients with breast cancer. However, this method has a limit: the covariance matrix involved in the g-prior should not be singular. But there are two standard cases in which it is singular: if the number of observations is lower than the number of variables, or if some variables are linear combinations of others. In such situations we propose to modify the g-prior by introducing a ridge parameter, and a simple way to choose the associated hyper-parameters. The prior obtained is a compromise between the conditional independent case of the coefficient regressors and the automatic scaling advantage offered by the g-prior, and can be linked to the work of Gupta and Ibrahim (2007).In the second part, we develop two new population-based MCMC methods. In cases of complex models with several parameters, but whose likelihood can be computed, the Equi-Energy Sampler (EES) of Kou et al. (2006) seems to be more efficient than the Parallel Tempering (PT) algorithm introduced by Geyer (1991). However it is difficult to use in combination with a Gibbs sampler, and it necessitates increased storage. We propose an algorithm combining the PT with the principle of exchange moves between chains with same levels of energy, in the spirit of the EES. This adaptation which we are calling Parallel Tempering with Equi-Energy Move (PTEEM) keeps the original idea of the EES method while ensuring good theoretical properties and a practical use in combination with a Gibbs sampler.Then, in some complex models whose likelihood is analytically or computationally intractable, the inference can be difficult. Several likelihood-free methods (or Approximate Bayesian Computational Methods) have been developed. We propose a new algorithm, the Likelihood Free-Parallel Tempering, based on the MCMC theory and on a population of chains, by using an analogy with the Parallel Tempering algorithm

This study employs Bayesian Hidden Markov Models as method to explore vehicle traffic flow conditions in an urban area in Stockholm, based on sensor data from separate road positions. Inter-arrival times are used as the observed sequences. These sequences of inter-arrival times are assumed to be generated from the distributions of four different (and hidden) traffic flow states; nightly free flow, free flow, mixture and congestion. The filtered and smoothed probability distributions of the hidden states and the most probable state sequences are obtained by using the forward, forward-backward and Viterbi algorithms. The No-U-Turn sampler is used to sample from the posterior distributions of all unknown parameters. The obtained results show in a satisfactory way that the Hidden Markov Models can detect different traffic flow conditions. Some of the models have problems with divergence, but the obtained results from those models still show satisfactory results. In fact, two of the models that converged seemed to overestimate the presence of congested traffic and all the models that not converged seem to do adequate estimations of the probability of being in a congested state. Since the interest of this study lies in estimating the current traffic flow condition, and not in doing parameter inference, the model choice of Bayesian Hidden Markov Models is satisfactory. Due to the unsupervised nature of the problematization of this study, it is difficult to evaluate the accuracy of the results. However, a model with simulated data and known states was also implemented, which resulted in a high classification accuracy. This indicates that the choice of Hidden Markov Models is a good model choice for estimating traffic flow conditions.

Modeindustrin karaktäriseras idag av fluktuerande efterfrågan och snabbt växlande trender, vilket gör att modeföretagens effektivitet ständigt sätts på sin spets för att möta marknadens förändringar. Förmågan att ta snabba beslut och anpassa sig till marknaden är idag avgörande för att vara konkurrenskraftig. Detta har bidragit till stora förändringar, inte enbart inom produktion och logistik, utan även inom inköp vilket har fått en allt mer viktig roll. Inköp och Supply Management är idag en vedertagen term i modeindustrin, inte bara på grund av sin finansiella inverkan utan även sin ökade strategiska roll i företaget. Enligt tidigare forskning kan en integrering av strategiskt inköp leda till konkurrensfördelar. Däremot har en brist i litteraturen gällande strategiskt inköp i fast fashion-företag identifierats. Syftet med denna studie var därför att undersöka inköpsfunktionens strategiska roll i svenska fast fashion-företag idag. Studien använder en kvalitativ forskningsmetod och resultatet baseras på empirisk data insamlad genom intervjuer. Intervjuerna har genomförts hos tre svenska fast fashion-företag med respektive fem respondenter vilka har omfattande kunskap och förståelse för företagets inköpsfunktion. Baserat på en analys av den empiriska datan gentemot insamlad sekundärdata från tidigare forskning drog slutsatsen att inköpsavdelningen i svenska fast fashion-företag har en viktig roll både ekonomiskt och strategiskt. Detta eftersom inköparnas beslut påverkar och kräver en kommunikation med stora delar av företaget. Vidare tyder studiens resultat på att strategiskt inköp faktiskt förekommer hos svenska fast fashion-företag, dock inte i sin helhet. Detta beror delvis på att strategiskt inköp såsom det definieras i litteraturen inte är ett vedertaget koncept hos de tre företagen. Avslutningsvis konstateras det att den tilltagande relevansen av strategiskt inköp kombinerat med den ökande globala konkurrensen tyder på att inköpsfunktionens strategiska roll kommer fortsätta växa.
Today’s fashion apparel industry is characterized by a volatile demand and fast trends. These toughened conditions have resulted in fashion companies constantly being put on their edge in order to follow the market changes. The ability to make quick decisions and adapt to the market is there fore crucial in order to stay competitive. This has led to extensive changes not only in production and logistics but also within purchasing operations, which in turn serve a more important role than ever. Purchasing and Supply management is nowadays an established termin the industry not only due to its financial effect but also its increasingly strategic role within the company. According to previous research, integrating a strategic approach towards the purchasing function might lead to competitive advantage. However, a shortage of research about strategic purchasing specifically in fast fashion companies has been identified. The purpose of this study was to examine the purchasing function’s current strategic role in Swedish fast fashion companies. The study uses a qualitative research approach and the result is based upon empirical data collected through interviews. These interviews have been conducted with five representatives of three Swedish fast fashion companies that have an extensive knowledge and understanding about the purchasing function. By analysing the empirical results in relation to secondary data obtained from previous research, it was found that the purchasing function in Swedish fast fashion companies holds an important role, both financially and strategically. This strategic importance is derived from the company wide impact of purchasers’ decision-making along with the need for communication between the purchasing function and other significant departments. Furthermore, the results indicate that strategic purchasing does in fact appear in Swedish fast fashion companies, although not to a full extent. This is partially due the fact that the concept of strategic purchasing, as the literature defines it, is not established within these three companies. At last it is concluded that the previously increased relevance of strategic purchasing combined with the cultivating globalisation indicates that the purchasing functions’ strategic role will continue to grow. The thesis is written in Swedish.

Detta arbete visualiserar värdeflöde av solceller vid tre olika typer av solcellsinstallationer följt av förslag till förbättring gällande ett växande installationsföretag i Sverige. Genom värdeflödesanalys kan vi se tydliga samband mellan snabb tillväxt och logistiska problem, där spårbarhet, lokaler och personal är viktiga faktorer som behöv bindas samman för att skapa ett så optimalt flöde som möjligt. Resultatet är delade i två grupper. En grupp består av visualisering och information kring hur värdeflödet ser ut och den andra av vilka förbättringsmöjligheter företaget har för sin framtida verksamhet. Vi kan också se att företaget har stor potential att öka sin lönsamhet genom att via affärssystem utveckla sin logistikhantering samt sammankoppla företagets olika instanser för att nå en mer effektiv installationsprocess.
This report visualizes the value stream of solar cells at three different types of installations, followed by proposal of improvement at a growing installation company in Sweden. Through value stream mapping, we see a clear connection between a fast growing rate and logistical problems, where traceability, facilities and staff are key factors, which needs to be connected to create as optimal flow as possible. The results are divided into two groups. The first consists of visualization and information of the current value stream and the second of what kind of improvement we suggest the company takes into consider to go even further. We can also see that the company has great potential to increase its profitability by implementing ERP to its logistical department and to connect the other departments to reach a higher level of efficiency.

“Overworking to death” is a phenomenon that has been noticeable in developing countries. The cause of death is mainly through ischemic strokes. While the victims’ occupations differed, they all shared a common characteristic, being positioned in a sedentary work, ranging from IT workers to doctors. This project’s aim was to develop a product that prevented or decreased the strokes that derived from sedentary overwork. This was mainly tackled by preventing one of the three causes of developing blood props, slowed blood flow. In order to gather rich data of the phenomenon, a qualitative study was conducted in China, during two months. By doing an extensive structured sampling, information rich data could be gathered during a short period of time. Data were derived from observations, questionnaires and an interview, which then was interpreted to customer needs and the final product specification. The final product became a trouser with an in built dynamic compression mechanic, that can compress the veins mostly during sitting activities, in order to prevent blood stasis. The compression mechanic works like the Chinese finger trap; compressing the calves while sitting and stretching the legs forward. It is made only out of polysaccharides fibres; cotton and corn.
"Guolaosi" eller död från överarbete är ett fenomen som i regel uppkommer bland utvecklingsländer. Dödsorsaken är huvudsakligen genom stroke. Offrens yrken varierar allt från professorer, IT-arbetare till läkare. De delar dock en sak gemensamt; att arbeta under långa perioder stillasittande. Projektets mål var att utveckla en produkt som minskar dödliga följderna av sedentära överarbete, genom att förebygga en av de tre orsakerna för att utveckla blodproppar; saktad blodström. Målgruppen var då kineser av de yrken som hade tidigare drabbats av fenomenet. För att samla informationsrika data om fenomenet genomfördes en kvalitativ studie i Kina under två månader. Genom att göra en omfattande strukturerad provtagning kunde informationsrika data samlas under en kort tidsperiod. Fältstudien bestod av observationer, frågeformulär och en intervju, som då tolkades till kundbehov och eventuellt produktspecifikationen. Den slutliga produkten kom att bli ett par byxor med en inbyggd dynamisk komprimeringsmekanism, som kan komprimera venerna under sittande aktiviteter, för att förhindra saktad blodström. Kompressionsmekanismen fungerar som den kinesiska fingerfällan. Den komprimerar blodkärlen medan personen sitter och sträcker benen framåt. Produkten är konstruerad på så sätt att den kan tillverkas endast av polysackariders tråd, från bomull och majs. Vilket är lämpligt för Kinas lokala resurser.

Doutoramento em Bioquímica
Os polissacarídeos são os componentes maioritários dos grãos de café verde e torrado e da bebida de café. Os mais abundantes são as galactomananas, seguindo-se as arabinogalactanas. Durante o processo de torra, as galactomananas e arabinogalactanas sofrem modificações estruturais, as quais estão longe de estar completamente elucidadas devido à sua diversidade e à complexidade estrutural dos compostos formados. Durante o processo de torra, as galactomananas e arabinogalactanas reagem com proteínas, ácidos clorogénicos e sacarose, originando compostos castanhos de alto peso molecular contendo nitrogénio, designados de melanoidinas. As melanoidinas do café apresentam diversas atividades biológicas e efeitos benéficos para a saúde. No entanto, a sua estrutura exata e os mecanismos envolvidos na sua formação permanecem desconhecidos, bem como a relação estrutura-atividade biológica. A utilização de sistemas modelo e a análise por espectrometria de massa permitem obter uma visão global e, simultaneamente, detalhada das modificações estruturais nos polissacarídeos do café promovidas pela torra, contribuindo para a elucidação das estruturas e mecanismos de formação das melanoidinas. Com base nesta tese, oligossacarídeos estruturalmente relacionados com a cadeia principal das galactomananas, (β1→4)-Dmanotriose (Man3), e as cadeias laterais das arabinogalactanas, (α1→5)-Larabinotriose (Ara3), isoladamente ou em misturas com ácido 5-Ocafeoilquínico (5-CQA), o ácido clorogénico mais abundante nos grãos de café verde, e péptidos compostos por tirosina e leucina, usados como modelos das proteínas, foram sujeitos a tratamento térmico a seco, mimetizando o processo de torra. A oxidação induzida por radicais hidroxilo (HO•) foi também estudada, uma vez que estes radicais parecem estar envolvidos na modificação dos polissacarídeos durante a torra. A identificação das modificações estruturais induzidas por tratamento térmico e oxidativo dos compostos modelo foi feita por estratégias analíticas baseadas principalmente em espectrometria de massa, mas também em cromatografia líquida. A cromatografia de gás foi usada na análise de açúcares neutros e ligações glicosídicas. Para validar as conclusões obtidas com os compostos modelo, foram também analisadas amostras de polissacarídeos do café obtidas a partir de resíduo de café e café instantâneo. Os resultados obtidos a partir dos oligossacarídeos modelo quando submetidos a tratamento térmico (seco), assim como à oxidação induzida por HO• (em solução), indicam a ocorrência de despolimerização, o que está de acordo com estudos anteriores que reportam a despolimerização das galactomananas e arabinogalactanas do café durante a torra. Foram ainda identificados outros compostos resultantes da quebra do anel de açúcares formados durante o tratamento térmico e oxidativo da Ara3. Por outro lado, o tratamento térmico a seco dos oligossacarídeos modelo (individualmente ou quando misturados) promoveu a formação de oligossacarídeos com um maior grau de polimerização, e também polissacarídeos com novos tipos de ligações glicosídicas, evidenciando a ocorrência de polimerização através reações de transglicosilação não enzimática induzidas por tratamento térmico a seco. As reações de transglicosilação induzidas por tratamento térmico a seco podem ocorrer entre resíduos de açúcares provenientes da mesma origem, mas também de origens diferentes com formação de estruturas híbridas, contendo arabinose e manose como observado nos casos dos compostos modelo usados. Os resultados obtidos a partir de amostras do resíduo de café e de café instantâneo sugerem a presença de polissacarídeos híbridos nestas amostras de café processado, corroborando a ocorrência de transglicosilação durante o processo de torra. Além disso, o estudo de misturas contendo diferentes proporções de cada oligossacarídeo modelo, mimetizando regiões do grão de café com composição distinta em polissacarídeos, sujeitos a diferentes períodos de tratamento térmico, permitiu inferir que diferentes estruturas híbridas e não híbridas podem ser formadas a partir das arabinogalactanas e galactomananas, dependendo da sua distribuição nas paredes celulares do grão e das condições de torra. Estes resultados podem explicar a heterogeneidade de estruturas de melanoidinas formadas durante a torra do café. Os resultados obtidos a partir de misturas modelo contendo um oligossacarídeo (Ara3 ou Man3) e 5-CQA sujeitas a tratamento térmico a seco, assim como de amostras provenientes do resíduo de café, mostraram a formação de compostos híbridos compostos por moléculas de CQA ligadas covalentemente a um número variável de resíduos de açúcar. Além disso, os resultados obtidos a partir da mistura contendo Man3 e 5-CQA mostraram que o CQA atua como catalisador das reações de transglicosilação. Por outro lado, nas misturas modelo contendo um péptido, mesmo contendo também 5-CQA e sujeitas ao mesmo tratamento, observou-se uma diminuição na extensão das reações transglicosilação. Este resultado pode explicar a baixa extensão das reações de transglicosilação não enzimáticas durante a torra nas regiões do grão de café mais ricas em proteínas, apesar dos polissacarídeos serem os componentes maioritários dos grãos de café. A diminuição das reações de transglicosilação na presença de péptidos/proteínas pode dever-se ao facto de os resíduos de açúcares redutores reagirem preferencialmente com os grupos amina de péptidos/proteínas por reação de Maillard, diminuindo o número de resíduos de açúcares redutores disponíveis para as reações de transglicosilação. Além dos compostos já descritos, uma diversidade de outros compostos foram formados a partir dos sistemas modelo, nomeadamente derivados de desidratação formados durante o tratamento térmico a seco. Em conclusão, a tipificação das modificações estruturais promovidas pela torra nos polissacarídeos do café abre o caminho para a compreensão dos mecanismos de formação das melanoidinas e da relação estrutura-atividade destes compostos.
Polysaccharides are the major components of green and roasted coffee beans, and coffee brew. The most abundant ones are galactomannans, followed by arabinogalactans. During the roasting process, galactomannans and arabinogalactans undergo structural modifications that are far to be completely elucidated due to their diversity and complexity of the compounds formed. During the roasting process, galactomannans and arabinogalactans react with proteins, chlorogenic acids, and sucrose, originating high molecular weight brown compounds containing nitrogen, known as melanoidins. Several biological activities and beneficial health effects have been attributed to coffee melanoidins. However, their exact structures and the mechanisms involved in their formation remain unknown, as well as the structure-biological activity relationship. The use of model systems and mass spectrometry analysis allow to obtain an overall view and, simultaneously, detailed, of the structural modifications in coffee polysaccharides promoted by roasting, contributing to the elucidation of the structures and formation mechanisms of melanoidins. Based on this thesis, oligosaccharides structurally related to the backbone of galactomannans, (β1→4)-D-mannotriose, and the side chains of arabinogalactans, (α1→5)-Larabinotriose, alone or in mixtures with 5-O-caffeoylquinic acid, the most abundant chlorogenic acid in green coffee beans, and dipeptides composed by tyrosine and leucine, used as models of proteins, were submitted to dry thermal treatments, mimicking the coffee roasting process. The oxidation induced by hydroxyl radicals (HO•) was also studied, since these radicals seem to be involved in the modification of the polysaccharides during roasting. The identification of the structural modifications induced by thermal and oxidative treatment of the model compounds was performed mostly by mass spectrometry-based analytical strategies, but also using liquid chromatography. Gas chromatography was used in the analysis of neutral sugars and glycosidic linkages. To validate the conclusions achieved with the model compounds, coffee polysaccharide samples obtained from spent coffee grounds and instant coffee were also analysed. The results obtained from the model oligosaccharides when submitted to thermal treatment (dry) or oxidation induced by HO• (in solution) indicate the occurrence of depolymerization, which is in line with previous studies reporting the depolymerization of coffee galactomannans and arabinogalactans during roasting. Compounds resulting from sugar ring cleavage were also formed during thermal treatment and oxidative treatment of Ara3. On the other hand, the dry thermal treatment of the model oligosaccharides (alone or when mixed) promoted the formation of oligosaccharides with a higher degree of polymerization, and also polysaccharides with new type of glycosidic linkages, evidencing the occurrence of polymerization via non-enzymatic transglycosylation reactions induced by dry thermal treatment. The transglycosylation reactions induced by dry thermal treatment can occur between sugar residues from the same origin, but also of different origins, with formation of hybrid structures, containing arabinose and mannose in the case of the model compounds used. The results obtained from spent coffee grounds and instant coffee samples suggest the presence of hybrid polysaccharides in these processed coffee samples, corroborating the occurrence of transglycosylation during the roasting process. Furthermore, the study of mixtures containing different proportions of each model oligosaccharide, mimicking coffee bean regions with distinct polysaccharide composition, subjected to different periods of thermal treatment, allowed to infer that different hybrid and non-hybrid structures may be formed from arabinogalactans and galactomannans, depending on their distribution in the bean cell walls and on roasting conditions. These results may explain the heterogeneity of melanoidins structures formed during coffee roasting. The results obtained from model mixtures containing an oligosaccharide (Ara3 or Man3) and 5-CQA and subjected to dry thermal treatment, as well as samples derived from spent coffee grounds, showed the formation of hybrid compounds composed by CQA molecules covalently linked to a variable number of sugar residues. Moreover, the results obtained from the mixture containing Man3 and 5-CQA showed that CQA acts as catalyst of transglycosylation reactions. On the other hand, in the model mixtures containing a peptide, even if containing 5-CQA and subjected to the same treatment, it was observed a decrease in the extent of transglycosylation reactions. This outcome can explain the low extent of non-enzymatic transglycosylation reactions during roasting in coffee bean regions enriched in proteins, although polysaccharides are the major components of the coffee beans. The decrease of transglycosylation reactions in the presence of peptides/proteins can be related with the preferential reactivity of reducing residues with the amino groups of peptides/proteins by Maillard reaction, decreasing the number of reducing residues available to be directly involved in the transglycosylation reactions. In addition to the compounds already described, a diversity of other compounds were formed from model systems, namely dehydrated derivatives formed during dry thermal treatment. In conclusion, the identification of the structural modifications in coffee polysaccharides promoted by roasting pave the way to the understanding of the mechanisms of formation of melanoidins and structure-activity relationship of these compounds.

碩士
逢甲大學
經營管理碩士在職專班
97
The dissertation adopted case study, took the supermarket of the case company and 7-Eleven (President Chain Store Corporation) as the research subjects, and did the initial analysis on the two companies via the industrial background and present conditions of supermarket and convenience store. For doing the deep-going management mode analysis, the research did the exploration on four dimensions of branch store extension mode, marketing and order management mode, logistic support business mode, and manpower resource management mode to explain and compare the two companies’ differences on four dimensions. Secondly, from each operational performance derived from the two companies’ financial statements, the research judged it was good or bad with excess returns, earnings quality, financial policy decision, and long-term operational performance, and analyzed their relationships with the management mode. The research findings are as follows: From four major operational performance indexes, the result showed that the management performance of the supermarket of the case company was not as good as 7-Eleven; to make deep-going analysis and explanation from excess returns, financial policy decision, and long-term operational performance, the case company’s operational mode should be adjusted so as to boost the operational performance; the future branch store extension can adopt the way of increasing franchise stores to expand the operational scale rapidly; besides, the store-within-a-store strategic alliance can increase the supermarket’s operational differentiation, and making use of the space of the store flexibly can boost the use efficiency so as to efficiently elevate capital turnover, and lower cost of goods sold rate and operating expense ratio to raise excess returns further. Moreover, the earnings uncertainty of the two companies was analyzed from earnings quality, and the result showed that 7-Eleven had high investment weight on professions outside of the original profession, resulting in greater variation of non-operating income and high earnings uncertainty; contrarily, the case company was absorbed in the original profession to operate; hence, from the angle of an investor, to invest on the case company was more secure relatively.

Item Response Theory (IRT) models are the basis of modern educational measurement. In order to increase testing efficiency, modern tests make ample use of groups of questions associated with a single stimulus (testlets). This violates the IRT assumption of local independence. However, a set of measurement models, testlet response theory (TRT), has been developed to address such dependency issues. This study investigates the effects of varying sample sizes and Markov Chain Monte Carlo burn-in chain lengths on the accuracy of estimation of a TRT model’s item and testlet parameters. The following outcome measures are examined: Descriptive statistics, Pearson product-moment correlations between known and estimated parameters, and indices of measurement effectiveness for final parameter estimates.
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碩士
國立高雄第一科技大學
行銷與流通管理所
92
Prosperity of chain store enterprise in Taiwan in recent years and the coming of knowledge economics era have forced chain store enterprise to deliberately study and implement topics in knowledge management for survival in an environment of keen competition. Due to lack of resource and maximization of resource facility efficiency, enterprises usually need to rely on support from and exchange of internal and external resources; completion of such activities require factors such as maintenance of internal and external partner relationship, common recognition, and structural position in social network(Nahapiet & Ghoshal, 1998). Such resources that are only available through a network with which inter-organizational linkages are embedded are social capital. Additionally, because knowledge and resource are often sticky(Szulanski, 1996), and are dispersedly embedded on members, routines, and processes in an organization, therefore, driving the flow, circulation, and proliferation of such embedded and dispersed knowledge to be effectively applied on organizational operation is one critical topic for enterprises and managers. 　　Hence, this research takes initiatives to discuss how chain store enterprise facilitates internal and external social capital accumulated from internal network between headquarter and chain stores and external network established with partners and customers, to promote effective implementation of knowledge circulation by mutual cooperation and linked interaction, and then enhance organizational performance. 　　Factual evidence suggests that the major findings of this research include (1)close social interaction and promotion of shared vision may actually enhance effective knowledge flow in terms of both quality and quantity; (2)establishment of linked connection and trust among external organization and persons may actually enhance quality of knowledge flow; (3)highly aligned correlation exists among internal and external social capital; (4)adjustment effects of partially strengthening and partially weakening exist in the relation of social capital to knowledge flow in a chain store enterprise with higher organizational learning competence; and (5)quantitative of knowledge flow may actually improves financial performance and consumer rating of a chain store enterprise.

Limited infrastructure in developing countries makes rapid and accurate diagnosis of Avian Influenza (AI) and Newcastle disease (ND) difficult. This project has examined a method for collecting and transporting samples that eliminates the problems associated with previous ways of managing viral outbreaks. This method, verified using Real time (quantitative) reverse transcriptase polymerase chain reaction (RT-qPCR), also overcomes quarantine restrictions between countries. An epidemiological study was then carried out using the collection and transportation method and the results of this study can be used to support further epidemiological studies of AI and ND and to standardise assays between countries. Diagnostic assays for AI and ND based on RT-qPCR have been developed and published. These assays use the deoxyribonucleic acid (DNA) binding dye, SYBR Green, or dual labelled TaqMan probes, (van Elden et al., 2001; Spackman et al., 2002; Tan et al., 2004; Ward et al., 2004; Pham et al., 2005; Payungporn et al., 2006b; Ong et al., 2007). However, SYBR Green and TaqMan probes have limitations. SYBR Green can inhibit PCR reactions because it degrades PCR products, while TaqMan probes have less sensitivity due to the specificity of the probe sequences. Therefore, a SYTO 9 RT-qPCR was developed for the AI and ND diagnosis. SYTO 9 RT-qPCR for AI virus (AIV) and ND virus (NDV) assays were successfully used. A series of new primers were evaluated and developed in these assays such as M+4100 forward and M-4220 reverse for ND detection of Class II NDVs (chicken) (Wise et al., 2004) and NDV MGB1 for ND detection of Class I NDVs (wild birds). For the AI screening test, a few pairs of primers based on the M gene were also evaluated (Ward et al., 2004; Heine et al., 2005). Subsequently, these diagnostic assays were used to evaluate sample collection and transportation without a cold chain. Further studies were also performed to evaluate the sequences of NDVs. This sequencing was intended to show the viral pathotyping and phylogenetic relationships of NDV. Primers that targeted a 343 bp Fusion sequence were designed and successfully used to amplify six Australian NDV isolates, both NDV Class I and Class II. Based on the amino acid sequence in the Fusion cleavage site, the six isolates were confirmed as low virulence of NDV. The motif of the cleavage sites were S-G-G-E-RQ- E-R-L-V, S-G-G-E-Q-Q-G-R-L-I and S-G-G-G-K-G-R-L-I. Evaluations of suitable buffers showed that Solid Tissue Digest Buffer (STDB) and Lysis Buffer (LB) were effective buffers for sample collection and transportation. Further studies showed that there was no significant difference between these two buffers. However, viability experiments showed that the LB deactivated both AI and NDV while STDB failed to fully inactivate NDV. Therefore, the lysis buffer was chosen for further sample collection and transportation without a cold chain. A protocol for the extraction of samples collected without cold chain was evaluated. This modified protocol was successfully integrated into the nucleic purification system using a robotic device and ribonucleic acid (RNA) extraction protocol (Corbett Research, Brisbane). However, extracted and purified RNA may be degraded by ribonuclease contamination. Therefore, this project also evaluated buffers for RNA storage after extraction. Evaluation of two modified buffers, the Tris EDTA (TE) carrier buffer (TCB) and modified RNA safe buffer (mRSB), showed that both buffers can prevent RNA degradation with no significant difference in cycle threshold (Ct)-Value detected by RT-qPCR. The method of collection and transportation samples without a cold chain was applied by collecting live viruses and also viral antigens in Indonesia and transporting to Australia. Due to the time limitation, viral isolates were collected only from AI viruses representing four different regions in Indonesia (Timika, Ambon, Tanggerang, and Sukabumi). For ND commercial antigens (Balitvet and Pusvetma) were purchased. The AI and ND samples were processed using a lysis buffer in the Quarantine Agency Laboratory of Indonesia and transported to James Cook University (JCU) in Townsville, Australia. Transported AI and ND viral RNA were successfully amplified using SYTO 9 RT-qPCR. This study confirmed that not only viral RNA but also inactivated viral RNA can be preserved, transported and detected after a month of processing. This transportation also verified that viral RNA can be recovered and detected after chemical inactivation. SYTO 9 RT-qPCR and TaqMan dual labelled probed RT-qPCR assays were carried out to screen the presence of AI viruses in the transport buffer. These assays used published protocols (Ward et al., 2004; Heine et al., 2005). The assays successfully detected viral RNA. However, the TaqMan dual labelled probe assay for H5 (Heine et al., 2005) failed to detect viral RNA in the Sukabumi isolates. Further studies of Indonesian AI isolates using High Resolution Melt assay recognised at least two populations from four different regions. Normalization data demonstrated that Timika and Ambon isolates were very similar while Tanggerang and Sukabumi isolates represented different populations. These results suggest that there is continued evolution of AI viruses in Indonesia. The ability of lysis buffer to preserve AI viral RNA was confirmed by amplification of 590bp and 1370 bp products from the Haemagglutinin (HA) gene. These products were successfully sequenced demonstrating that the viral RNA transported using lysis buffer was not fragmented. As a result, a molecular epidemiology study of AI and ND isolates was successfully carried out using the samples transported without a cold chain. However, at this stage, the method of collection and transportation of samples without a cold chain has not been applied to field and clinical samples. The value of the technique would be enhanced if it could be demonstrated that it works equally well for swabs and tissues collected in the field.

The research attempts to evaluate the maintaining of the chain of evidence as a process of effective collection, handling and preservation of evidence. The concept "chain of evidence" refers to the process of collecting, handling and preservation of evidence until its presentation in court, as part of the investigation process. Evidence is anything that tends logically to prove or disprove a fact at issue in a judicial case. Evidence essentially consists of oral evidence, documentary evidence and real evidence. The value of evidence cannot be underestimated as evidence can make or break a case. It is therefore important that evidence is correctly and properly collected, handled and preserved to establish a strong link between an individual and a specific act.
Police Practice
Thesis ((M. Tech. (Forensic Investigation) Police Practice))

Salmonella species is the etiologic agent of salmonellosis, which is a zoonotic infection that is characterized by diarrhea and systemic infection. Contaminated foods are usually the vehicles of Salmonella transmission along the food supply chain. Asymptomatic food production animals and effluents also contribute to contamination of meat. Antimicrobials have contributed significantly to treatment of salmonellosis. However, uncontrolled antimicrobial use is among the causes of antibiotic resistance, which results in treatment failure. The aim of this research study was to determine the extent of Salmonella spp contamination during the cattle slaughtering process in South African rural abattoirs (n = 23), water and cattle feaces. In addition, the aim was to determine antimicrobial resistance profiles of the Salmonella spp isolates. The specific objectives were: i) to establish the occurrence and distribution of Salmonella spp on cattle carcasses, hides, and intestinal contents and environmental samples using classical microbiology and molecular techniques; ii) to determine the Salmonella serovars using serotyping; and iii) to determine antimicrobial resistance patterns and multidrug resistance among the Salmonella isolates using the Kirby-Bauer disc diffusion method. Materials and Classical microbiology techniques were used to analyze cattle faeces (n = 400), hides (n = 67), intestinal contents (n = 62), carcass sponges (n = 100), and water from the abattoirs (n = 75) for the presence of Salmonella spp. Further confirmation of the Salmonella isolates was done using Polymerase Chain Reaction whereby the invA gene was targeted. A total of 92 Salmonella spp isolates were recuperated. The 92 Salmonella were serotyped as described in the White-Kauffmann-Le Minor scheme. The 92 Salmonella spp isolates were further subjected to antimicrobial susceptibility examination towards the following antimicrobials: ampicillin (10μg), cefotaxine (30μg), kanamycin (30μg), oxytetracycline (30μg), and enrofloxacin (5μg) by using the Kirby-Bauer disk diffusion procedure. All the isolates carried the invA genes. The average Salmonella spp occurrence on carcasses, hides, and intestinal contents was 35.37% (n = 81). Eleven of the faecal samples (2.75%) tested positive for Salmonella spp. The Salmonella serovar that occurred more frequently was S. Enteritidis. Different serovars that were recognized on carcasses were not automatically found on the hides and intestinal contents. The incompatible frequency of the different Salmonella serovars on carcasses, intestinal contents and hides means that in addition to carriage on hides and in intestinal contents, new external causes that did not form part of this study also play a vital role concerning carcass contamination. Most Salmonella spp (n = 66; 71.7%) isolates were resistant to a minimum of one antimicrobial with main resistance detected towards oxytetracycline (51.90%). This emphasizes on the call for wise antimicrobial use at some stage in animal production and strict sanitation for the duration of slaughtering. Briefly, cattle slaughtered in South African rural abattoirs harboured different types of Salmonella serovars that were resistant to antimicrobials, which could be a public health risk and danger. The outcome should support policymakers with determining the effectiveness of existing sanitary measures during cattle slaughtering in rural abattoirs, which is vital from socio-economic, public health, and epidemiological perspectives.
College of Agriculture and Environmental Sciences