According to Markus's theory of reuse, when digital repositories are deployed to collect and distribute organizational assets, they supposedly help ensure accountability, extend information exchange, and improve productivity. Such repositories require a large investment due to the continuing costs of hardware, software, user licenses, training, and technical support. The problem addressed in this study was the lack of evidence in the literature on whether users in fact reused enough digital assets in repositories to justify the investment. The objective of the study was to investigate the organizational value of repositories to better inform architectural, construction, software and other industries whether repositories are worth the investment. This study was designed to examine asset reuse of medical images at a health information publisher. The research question focused on the amount of asset reuse over time, which was determined from existing repository transaction logs generated over an 8-year period by all users. A longitudinal census data analysis of archival research was performed on the entire dataset of 85,250 transaction logs. The results showed that 42 users downloaded those assets, including 11,059 images, indicating that the repository was used by sufficient users at this publisher of about 80 employees. From those images, 1,443 medical images were reused for new product development, showing a minimal asset reuse rate of 13%. Assistants (42%), writers (20%), and librarians (16%) were the primary users of this repository. Collectively, these results demonstrated the value of repositories in improving organizational productivity---through reuse of existing digital assets such as medical images to avoid unnecessary duplication costs---for social change and economic transformation.

Even though the current level of communication and information sharing is greater than it has ever been throughout the history of the construction industry, the problem under investigation stems from the results of current research that indicate that many major projects have difficulty in achieving client expectations, resulting in a negative image of the construction industry. The purpose of this study was to analyze the impact on the level of trust in the use of information systems between construction firms and their clients. The theoretical foundations of this research were based in interdependence and coordination theories. While information systems enable improved communication processes, coordination and interdependency are central to mutually successful completion of construction projects. However, there is a lack of a prescriptive view present in the literature regarding the role of trust in enhancing client satisfaction through the use of information systems. The research questions that underlay this study were based on discovering the extent and nature of mistrust between contractors and their clients. Through the use of a qualitative methodology, data were collected through responses from a semi-structured, open-ended questionnaire. By analyzing consistencies in the responses, the researcher used grounded theory to determine trends and consistencies. The results revealed that while contractors believed trust existed between contractors and clients, clients believed mutual trust was low despite the increased communication through emails and current information systems. By emphasizing the notion of mutual trust in the communication process, contractors can improve the image of the construction industry. The magnitude of social change could result in more successful and timely completion of projects saving millions of dollars.

Abstract not available

The Australian HIV Observational Database (AHOD) is a collaboration of hospitals, sexual health clinics and specialist general practices throughout Australia, established in April 1999. Core data variables collected include demographic data, immunological and virological markers, AIDS diagnosis, antiretroviral and prophylactic treatment and cause of death. The first electronic data transfer occurred in September 1999 followed by six monthly data transfers thereafter. All analyses included in this thesis are based on patients recruited to AHOD by March 2004. By March 2004, 2329 patients had been recruited to AHOD from 27 sites throughout Australia. Of these, 352 (15%) patients were recruited from non-metropolitan clinics. The majority of patients were male (94%), and infected with HIV through male homosexual contact (73%). Almost 90% of AHOD patients are antiretroviral treatment experience, and the majority of patients are receiving triple therapy as mandated by standard of care guidelines in Australia. Antiretroviral treatment use has changed in Australia reflecting changes in the availability of new treatment strategies and agents. The crude mortality rate was 1.58 per 100 person years, and of the 105 deaths, more than half died from HIV-unrelated deaths. The prevalence of HBV and HCV in AHOD was 4.8% and 10.9%, respectively. HIV disease progression in the era of highly active antiretroviral treatment (HAART) among AHOD patients is consistent with what has been reported in developed countries. Common factors associated with HIV disease progression were low CD4 cell count, high viral load and prior treatment with mono or double therapy at the time of commencing HAART. This was demonstrated in AHOD in terms of long-term CD4 cell response, the rate of changing combination antiretroviral therapy and factors predicting death. HBV and HCV coinfection is also relatively common in AHOD, similar to other developed country cohorts. Coinfection does not appear to be serious impediments to the treatment of HIV infected patients. However, HIV disease outcome following HAART does appear to be adversely affected by HIV/HCV coinfection but not in terms of HIV/HBV coinfection. Patients attending non-metropolitan sites were found to be similar to those attending metropolitan sites in terms of both immunological response and survival.

This thesis examines HIV disease natural history and response to antiretroviral treatment (ART) in patients from The TREAT Asia HIV Observational Database (TAHOD), a mulitcentre, prospective observational cohort of HIV-infected patients from countries in the Asia-Pacific region. By September 2005, 2979 patients have been recruited to TAHOD from 15 participating sites. The majority were male (73%), median age 37 years. Chinese (37%), Thai (25%) and Indian (17%) were the main ethnicities. Most patients reported HIV infection through heterosexual (59%) and homosexual contact (23%); 5% injecting drug use. At baseline, 41% of patients were diagnosed with AIDS defining illness, and 77% were being treated with highly active antiretroviral therapy (HAART). Baseline and retrospective data suggest that the overall response to HAART in TAHOD is similar to that seen in western cohorts, with mean CD4 count increase of 115 cells/μL and 69% achieving a viral load less than 400 copies/mL six-month after HAART initiation. Baseline CD4 count was the strongest predictor of short-term disease progression. Prognostic models based on routine clinical data and haemoglobin gave a good estimation of disease progression. The rate of new AIDS defining illness was 26% in the first 90 days after HAART initiation, which may partly be due to immune reconstitution syndrome occurring shortly after treatment. The most frequently used first-line ART combination was stavudine/lamivudine/nevirapine. Approximately 22% of patients receiving this treatment changed or stopped at least one drug in the first year, with adverse effect (including lipodystrophy, hepatitis, rash and peripheral neuropathy) the major reasons. The rates of discontinuation of efavirenz or nevirapine as part of HAART were similar (16 vs. 20/100 person years). Older age and positive HCV antibody were associated with an elevated liver function (ALT) test. Both prevalence of HBV and HCV coinfection with HIV were approximately 10%. The impact of hepatitis coinfection on immunological and virological responses to ART and HIV disease progression was not statistically significant. Both HBV and HCV remained independently associated with elevated ALT in the multivariate models. The overall HIV disease progression and response to ART in TAHOD patients were similar to those seen in the western countries.

Feature selection is one of the important data preprocessing steps in data mining. The feature selection problem involves finding a feature subset such that a classification model built only with this subset would have better predictive accuracy than model built with a complete set of features. In this study, we propose two hybrid methods for feature selection. The best features are selected through either the hybrid methods or existing feature selection methods. Next, the reduced dataset is used to build classification models using five classifiers. The classification accuracy was evaluated in terms of the area under the Receiver Operating Characteristic (ROC) curve (AUC) performance metric. The proposed methods have been shown empirically to improve the performance of existing feature selection methods.

The past few decades have witnessed a revolution in recombinant DNA and nucleic acid sequencing technologies. Recently however, technologies capable of massively high-throughout, genome-wide data collection, combined with computational and statistical tools for data mining, integration and modeling have enabled the construction of predictive networks that capture cellular regulatory states, paving the way for ‘Systems biology’. Consequently, protein interactions can be captured in the context of a cellular interaction network and emergent ‘system’ properties arrived at, that may not have been possible by conventional biology. The ability to generate data from multiple, non-redundant experimental sources is one of the important facets to systems biology. Towards this end, we have established a novel platform called ‘spotted cell microarrays’ for conducting image-based genetic screens. We have subsequently used spotted cell microarrays for studying multidimensional phenotypes in yeast under different regulatory states. In particular, we studied the response to mating pheromone using a cell microarray comprised of the yeast non-essential deletion library and analyzed morphology changes to identify novel genes that were involved in mating. An important aspect of the mating response pathway is large-scale spatiotemporal changes to the proteome, an aspect of proteomics, still largely obscure. In our next study, we used an imaging screen and a computational approach to predict and validate the complement of proteins that polarize and change localization towards the mating projection tip. By adopting such hybrid approaches, we have been able to, not only study proteins involved in specific pathways, but also their behavior in a systemic context, leading to a broader comprehension of cell function. Lastly, we have performed a novel metabolic starvation-based screen using the GFP-tagged collection to study proteome dynamics in response to nutrient limitation and are currently in the process of rationalizing our observations through follow-up experiments. We believe this study to have implications in evolutionarily conserved cellular mechanisms such as protein turnover, quiescence and aging. Our technique has therefore been applied towards addressing several interesting aspects of yeast cellular physiology and behavior and is now being extended to mammalian cells. / text

This Thesis addresses how Semantic Web representations, in particular RDF, can enable flexible and scalable preservation, recreation, and querying of databases. An approach has been developed for selective scalable long-term archival of relational databases (RDBs) as RDF, implemented in the SAQ (Semantic Archive and Query) system. The archival of user-specified parts of an RDB is specified using an extension of SPARQL, A-SPARQL. SAQ automatically generates an RDF view of the RDB, the RD-view. The result of an archival query is RDF triples stored in: i) a data archive file containing the preserved RDB content, and ii) a schema archive file containing sufficient meta-data to reconstruct the archived database. To achieve scalable data preservation and recreation, SAQ uses special query rewriting optimizations for the archival queries. It was experimentally shown that they improve query execution and archival time compared with naïve processing. The performance of SAQ was compared with that of other systems supporting SPARQL queries to views of existing RDBs. When an archived RDB is to be recreated, the reloader module of SAQ first reads the schema archive file and executes a schema reconstruction algorithm to automatically construct the RDB schema. The thus created RDB is populated by reading the data archive and converting the read data into relational attribute values. For scalable recreation of RDF archived data we have developed the Triple Bulk Load (TBL) approach where the relational data is reconstructed by using the bulk load facility of the RDBMS. Our experiments show that the TBL approach is substantially faster than the naïve Insert Attribute Value (IAV) approach, despite the added sorting and post-processing. To view and query semi-structured Topic Maps data as RDF the prototype system TM-Viewer was implemented. A declarative RDF view of Topic Maps, the TM-view, is automatically generated by the TM-viewer using a developed conceptual schema for the Topic Maps data model. To achieve efficient query processing of SPARQL queries to the TM-view query rewrite transformations were developed and evaluated. It was shown that they significantly improve the query execution time. / eSSENCE

This thesis examines HIV disease natural history and response to antiretroviral treatment (ART) in patients from The TREAT Asia HIV Observational Database (TAHOD), a mulitcentre, prospective observational cohort of HIV-infected patients from countries in the Asia-Pacific region. By September 2005, 2979 patients have been recruited to TAHOD from 15 participating sites. The majority were male (73%), median age 37 years. Chinese (37%), Thai (25%) and Indian (17%) were the main ethnicities. Most patients reported HIV infection through heterosexual (59%) and homosexual contact (23%); 5% injecting drug use. At baseline, 41% of patients were diagnosed with AIDS defining illness, and 77% were being treated with highly active antiretroviral therapy (HAART). Baseline and retrospective data suggest that the overall response to HAART in TAHOD is similar to that seen in western cohorts, with mean CD4 count increase of 115 cells/μL and 69% achieving a viral load less than 400 copies/mL six-month after HAART initiation. Baseline CD4 count was the strongest predictor of short-term disease progression. Prognostic models based on routine clinical data and haemoglobin gave a good estimation of disease progression. The rate of new AIDS defining illness was 26% in the first 90 days after HAART initiation, which may partly be due to immune reconstitution syndrome occurring shortly after treatment. The most frequently used first-line ART combination was stavudine/lamivudine/nevirapine. Approximately 22% of patients receiving this treatment changed or stopped at least one drug in the first year, with adverse effect (including lipodystrophy, hepatitis, rash and peripheral neuropathy) the major reasons. The rates of discontinuation of efavirenz or nevirapine as part of HAART were similar (16 vs. 20/100 person years). Older age and positive HCV antibody were associated with an elevated liver function (ALT) test. Both prevalence of HBV and HCV coinfection with HIV were approximately 10%. The impact of hepatitis coinfection on immunological and virological responses to ART and HIV disease progression was not statistically significant. Both HBV and HCV remained independently associated with elevated ALT in the multivariate models. The overall HIV disease progression and response to ART in TAHOD patients were similar to those seen in the western countries.

Diss. (sammanfattning) Uppsala : Univ., 2003. / Härtill 6 uppsatser.