Thesis (Ph. D.)--University of Missouri-Columbia, 2003. / Typescript. Vita. Includes bibliographical references (leaves 101-107). Also available on the Internet.

Thesis (Ph. D.)--University of Hong Kong, 2002. / Includes bibliographical references (leaves 147-156).

Parenteral nutrition (PN) is a method of feeding those incapable of absorbing nutrients from the gastrointestinal tract. All required nutrients are combined in one "big bag". Consequently, many chemical interactions are possible between components. Ascorbic acid (AA) is ubiquitous to both animal and plant kingdoms. Although its biochemistry is not fully understood, dietary deficiency is detrimental to well being, with the most extreme condition being scurvy. AA is water-soluble and frequent intake is therefore required to maintain nutritional status. AA is possibly the most reactive additive in PN mixtures, readily reacting with dissolved oxygen, initially producing dehydroascorbic acid (OHAA). OHAA retains the biological activity of AA. It was the purpose of this study to further knowledge regarding stability of AA and OHAA in PN mixtures, informing pharmaceutical practice to improve safety and efficacy of PN. A stability-indicating HPLC method was optimised for the study of AA and OHAA in PN mixtures. A study of the kinetics of OHAA degradation was undertaken to provide data that could be used to predict OHAA stability. Results obtained indicated a first order reaction. In direct contrast to AA degradation, trace elements did not catalyse OHAA degradation. A further product of AA degradation is oxalic acid (OA) which is potentially toxic. A HPLC method for the determination of OA in PN mixtures was developed and validated, although minimum quantification limits were relatively high (~10J.Lg/ml).The method was used to assess OA appearance in stored PN mixtures, with results indicating that concentrations remained below 10J.Lg/ml even after 35 days storage. The final aspect of this research was to investigate the most likely components of a PN mixture which may "protect" AA from oxidation. a-tocopherol photo-oxidises and therefore may compete with AA for oxygen. As light catalyses the reaction it is possible oxygen reacts more rapidly with a-tocopherol compared with AA. Results indicated 0.- Tocopherol did not oxidise in preference to AA and therefore offered no "protection". Cysteine is a reducing agent included in some amino acid preparations. The average dissolved oxygen content of standard adult PN mixtures was determined, from which the amount of cysteine required to react with dissolved oxygen was calculated. AA instability in PN mixtures was compared with and without cysteine. Results indicated that adding cysteine to PN mixtures 24 hours before addition of AA, resulted in retention of >95% AA. Results obtained from this study have furthered knowledge of the AA degradation profile, its kinetics and the potential influence of other components in PN mixtures. In particular potential strategies for minimising AA degradation are identified therefore ensuring patients receive quantities approaching those prescribed.

Small information technology and management consulting businesses face increasingly contradictory strategic choices as they develop products and services for the marketplace. Building contextual ambidexterity is essential to the survival of small businesses as they seek to attain a desired balance of alignment and adaptability. Human Resource Management practices facilitate the development of ambidexterity within individuals thereby facilitating ambidexterity of the organization as a whole. Studies suggest that in order for an organization to be ambidextrous, its human resource management function also needs to ambidextrous. High-performance work systems are human resource practices designed to enhance the ability, motivation, and opportunity of employees with the overarching goal of attracting, retaining, and motivating human resources toward the completion of organizational goals. Based on Gibson and Birkinshaw’s concept of organizational ambidexterity, a qualitative case study of a small technology solution provider was conducted to explore the process by which CloudCo attempted to build contextual ambidexterity by implementing a high-performance work system. Findings show that executive management of small technology solution providers can build contextual ambidexterity and sustain a competitive advantage through the implementation of high-performance work systems but must overcome a series of important tensions to do so.

Many signal and image processing systems for high-throughput, high-performance applications require concurrent implementations in order to realize desired performance. Developing software for concurrent systems is widely acknowledged to be difficult, with common industry practice leaving the burden of preventing concurrency problems on the programmer. The Kahn Process Network model provides the mathematically provable property of determinism of a program result regardless of the execution order of its processes, including concurrent execution. This model is also natural for describing streams of data samples in a signal processing system, where processes transform streams from one data type to another. However, a Kahn Process Network may require infinite memory to execute. I present the dynamic distributed deadlock detection and resolution (D4R) algorithm, which permits execution of Process Networks in bounded memory if it is possible. It detects local deadlocks in a Process Network, determines whether the deadlock can be resolved and, if so, identifies the process that must take action to resolve the deadlock. I propose the Computational Process Network (CPN) model which is based on the formalisms of Kahn’s PN model, but with enhancements that are designed to make it efficiently implementable. These enhancements include multi-token transactions to reduce execution overhead, multi-channel queues for multi-dimensional synchronous data, zero-copy semantics, and consumer and producer firing thresholds for queues. Firing thresholds enable memoryless computation of sliding window algorithms, which are common in signal processing systems. I show that the Computational Process Network model preserves the formal properties of Process Networks, while reducing the operations required to implement sliding window algorithms on continuous streams of data. I also present a high-throughput software framework that implements the Computational Process Network model using C++, and which maps naturally onto distributed targets. This framework uses POSIX threads, and can exploit parallelism in both multi-core and distributed systems. Finally, I present case studies to exercise this framework and demonstrate its performance and utility. The final case study is a three-dimensional circular convolution sonar beamformer and replica correlator, which demonstrates the high throughput and scalability of a real-time signal processing algorithm using the CPN model and framework. / text

(Uncorrected OCR) Abstract Porphobilinogen (PBG) synthase condenses two molecules of aminolaevulinic acid (ALA) to form PBG in heme biosynthesis. The enzyme activity is sensitive to inhibition by heavy metals such as lead. It can act as a biological indicator of chronic lead POis~r\g to identify the risk group, especially in children, so that early treatment can be given to prevent possible permanent damages. A reversed-phase ion-pair HPLC analytical method for the assay of the PBG synthase activity based on detection of PBG production has been validated. A Hypersil CN column (150 x 4.6 mm; 5 urn) was employed together with a mixture of acetonitrile-40 mM phosphate buffer at pH 2.4 with 5 mM 1-heptanesulphonic acid (8:92, v/v). UV detection was performed at 240 nm. PBG was eluted as a spectrally pure peak resolved from its impurities in the methanol-inhibited enzyme reaction. The method was sensitive with a limit of quantitation of 2 ~M. The within-run and between-run precisions were 8.2% and 13.8% respectively. The recovery was 93.4 �7.1% (n=6). The preliminary reference range of the PBG synthase activities in the local pediatric population were from 21.5 to 26.3 ~mol/L RBC/min. Bland and Altman statistical analysis showed that the HPLC assay and the colorimetric assay could not be used interchangeably. The HPLC assay was an alternative way to assess the PBG synthase activities in the human erythrocyte samples. IV / abstract / toc / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / abstract / toc / Medical Sciences / Master / Master of Medical Sciences

published_or_final_version / Chemistry / Doctoral / Doctor of Philosophy

Flexible electronics using III-V materials for nano-electronics with high electron mobility and optoelectronics with direct band gap are attractive for many applications. This thesis describes a complementary metal oxide semiconductor (CMOS) compatible process for transforming traditional III-V materials based electronics into flexible one. The thesis reports releasing 200 nm of Gallium Arsenide (GaAs) from 200 nm GaAs / 300 nm Aluminum Arsenide (AlAs) stack on GaAs substrate using diluted hydrofluoric acid (HF). This process enables releasing a single top layer compared to peeling off all layers with small sizes at the same time. This is done utilizing a network of release holes that contributes to the better transparency (45 % at 724 nm wavelengths) observed. Fabrication of metal oxide semiconductor capacitor (MOSCAPs) on GaAs is followed by releasing it to have devices on flexible 200 nm GaAs. Similarly, flexible GaSb and InP fabrication process is also reported to transform traditional electronics into large-area flexible electronics.

This research is about disaster relief semi-temporary housing in China which based on disasters database, area selection and climate data in Yunnan Province, attempting to develop an effective and comfortable earthquake relief temporary shelter which can be processing both physical relief and psychological relief. The major components of this research are post-disaster analysis, project design, and computer simulation. By designing a new shelter model, we will try to identify different functions and reorganize them for the shelter in order to satisfy all special requests after disasters. After computer simulation, it will allow more energy efficient considerations and taking social responsibility to both the designing part and disaster relief process.