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The influences of loading cholesterol into stallion spermatozoa membranes prior to cold storage or cryopreservation were determined using cholesterol loaded cyclodextrin (CLC) before preservation, followed by the unloading of cholesterol after preservation using methyl beta cyclodextrin (MBCD). Experiment I: dose response trials determining optimal amounts of CLC and MBCD based on percentages of progressively motile spermatozoa (PMS) following preservation. Experiment II: influences of CLC and MBCD on PMS, the percentages of live intact (LI) and live non-intact (LNI) spermatozoa following cold storage. Experiment III: influences of CLC before cryopreservation and MBCD on PMS, LI, and LNI post-thaw. Addition of CLC improved (P<0.05) PMS and LI following preservation when compared to the control. Unloading cholesterol using MBCD does not alter PMS, LI nor LNI. Addition of CLC is beneficial to survival of spermatozoa following preservation and addition of MBCD in small amounts does not negatively influence PMS, LI or LNI.

Research was undertaken to optimize propagation of the southern China native Camptotheca acuminata Decaisne, source of the medicinal compound camptothecin that is used in the treatment of multiple forms of cancer and other diseases. The study focused on cutting propagation, micropropagation, and seed storage. Softwood cuttings of C. acuminata rooted readily in intermittent mist (4 sec on every 6 min.) in coarse vermiculite when treated with K-IBA (indolebutyric acid, potassium salt) quick dips ranging from 4.14 mM to 37.3 mM, with a 29.0 mM quick dip (5 sec.) promoting 82% rooting with little foliar damage. Actively growing shoot tip explants were tissue cultured on media containing Murashige and Skoog, Gamborg's B5, and Woody Plant Medium (WPM) salts in factorial combinations with BA (benzyladenine). WPM containing 4.44 μM BA promoted excellent shoot proliferation; microcuttings were rooted, acclimated, and grown in the greenhouse. Seeds stored in polyethylene bags in a refrigerator (4°C) or freezer (-20°C) maintained good germination (81% and 80%, respectively) while seeds stored at room temperature (25°C) in polyethylene bags lost germination ability quickly (58%) after one year of storage. C. acuminata is readily adaptable to modern nursery techniques for either vegetative or seed propagation.

Understanding the mechanisms plants utilize for seed storage protein (SSP) synthesis, transport and deposition have the potential rewards of enabling high yields of modified or foreign proteins. Hayashi et al. (1999) indicated that the machinery devoted to the synthesis of protein storage vacuoles in cotyledon cells can be induced in vegetative tissue by the constitutive expression of a pumpkin 2S albumin phosphinothricin-acetyl-transferase gene fusion (pumpkin 2S-PAT) resulting in the biogenesis of precursor-accumulating (PAC) vesicles in Arabidopsis leaves. This discovery was the impetus behind the work described which sought to examine this phenomenon further by ectopically evoking SSP trafficking and vesicle biogenesis machinery in leaves. With the aim of elucidating the mechanisms necessary to evoke PAC vesicle biogenesis, a suite of constructs including the pumpkin 2S-PAT and analogous napin-PAT and napin-GFP variants were synthesized. Analysis of these transgenes in Arabidopsis revealed that the pumpkin 2S albumin has a capacity unique from napin peptides to result in fusion protein accumulation. Further, the truncated pumpkin 2S albumin peptide and the pumpkin 2S albumin C-terminus were found to direct deposition to vesicles; however, the C-terminus alone was not enough to direct deposition to vesicles unless combined with a significantly shortened napin peptide. An increased ER protein throughput was correlated to trafficking of the fusion protein by Golgi-independent mechanisms resulting in stable accumulation of the unprocessed protein whereas less ER throughput indicated passage through the Golgi-dependent pathway resulting in accumulation of a processed variant. At the level of gene expression, as examined by a microarray study, both inducible and constitutive ectopic expression of pumpkin 2S-PAT resulted in substantial perturbations of the endomembrane system affecting protein folding, flowering time and ER-associated biosynthetic functions which indicated that modulation of flowering time and photoperiodism are highly dependent on protein trafficking and vacuolar biogenesis mechanisms and that high ER protein throughput occurs at the expense of biosynthesis and cessation of ER functioning.

This thesis analyses the development of the database for historical research within the context of the historical discipline. The first chapter gives a brief outline of the history of database technology and describes the theoretical perspectives from the history and sociology of technology which inform this work. The second chapter charts the development of the database for historical research from its beginnings in the 1960s to the present. This chapter situates the development of the database for historical research within the methodological and institutional frameworks that influenced its production. The third chapter analyses the historical database within the specific national context of Canadian historiography. This chapter provides an opportunity to investigate more closely the social constitution of a technology among a specialized group of users.

Using information retrieval systems to gain access to documents in languages other than English is becoming an increasingly significant problem. Rules, theories, algorithms, and retrieval methods designed and developed for English and other morphologically similar languages may or may not apply in the linguistic environments of other languages. The problem is particularly acute in languages that differ radically from English on account of morphological rules. This thesis compares the effects of two indexing and retrieval techniques (stemming and root retrieval) on information retrieval in Arabic through an exploratory study of the handling of Arabic words by an English search engine. It also investigates how best to adapt existing English-language information retrieval systems for use with Arabic-language texts, and specifically to process words and their morphological variations. Search experiments, using 2000 Arabic documents and 40 Arabic search terms (nouns), were conducted with a Web search engine developed for English, AltaVista, to compare the performances of stemming and root retrieval and to investigate the possibility of adapting this engine for use with Arabic text. The results of the experiments show that more effective retrieval can be accomplished through stemming, and that it is possible to adapt the engine for use with Arabic without the need to develop root-retrieval features.

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Forced convection cooling process is the most widely used method of cooling to extend shelf life of horticultural produce after harvest. However, heterogeneous cooling of produce inside different parts of ventilated packages is a serious problem. Therefore, it is essential to design packages that facilitate air circulation throughout the entire package to provide uniform cooling. Selection of appropriate combinations of air temperature and velocity for a given vent design is currently done largely by experimental trial and error approach. A more logical approach in designing new packages, to provide uniform cooling, is to develop mathematical models that would be able to predict package performance without requiring costly experiments. / In this study, mathematical models of simultaneous airflow, heat and mass transfer during forced convection cooling process were developed and validated with experimental data. The study showed that produce cooling is strongly influenced by different ventilated package designs. Generally, cooling uniformity was increased by increasing number of vents from 1 (2.4% vent area) to 5 (12.1% vent area). More uniform produce cooling was obtained at less cooling time when vents were uniformly distributed on package walls with at least 4.8% opening areas. Aerodynamic studies showed that heterogeneity of airflow distribution during the process is strongly influenced by different package vent configurations. The highest cooling heterogeneity index (108%) was recorded at 2.4% vent area whereas lowest heterogeneity index (0%) was detected in a package with 12.1% vent area. / The magnitudes of produce evaporative cooling (EC) and heat generation by respiration (HG) as well as the interactive effects of EC, HG and package vent design on produce cooling time were also investigated. Considerable differences in cooling times were obtained with regard to independent and simultaneous effects of EC and HG in different package vent configurations. Cooling time was increased to about 47% in a package with 1 vent compared to packages with 3 and 5 vents considering simultaneous effects of EC and HG. Therefore, the effects of EC and HG can be influential in designing the forced-air precooling system and consequently, in the accurate determination of cooling time and the corresponding refrigeration load.

The past decade has seen extensive research on audio classification algorithms which playa key role in multimedia applications, such as the retrieval of audio information from an audio or audiovisual database. However, the effect of background noise on the performance of classification has not been widely investigated. Motivated by the noise-suppression property of the early auditory (EA) model presented by Wang and Shamma, we seek in this thesis to further investigate this property and to develop improved algorithms for audio classification in the presence of background noise. / With respect to the limitation of the original analysis, a better yet mathematically tractable approximation approach is first proposed wherein the Gaussian cumulative distribution function is used to derive a new closed-form expression of the auditory spectrum at the output of the EA model, and to conduct relevant analysis. Considering the computational complexity of the original EA model, a simplified auditory spectrum is proposed, wherein the underlying analysis naturally leads to frequency-domain approximation for further reduction in the computational complexity. Based on this time-domain approximation, a simplified FFT-based spectrum is proposed wherein a local spectral self-normalization is implemented. An improved implementation of this spectrum is further proposed to calculate a so-called FFT-based auditory spectrum, which allows more flexibility in the extraction of noise-robust audio features. / To evaluate the performance of the above FFT-based spectra, speech/music/noise and noise/non-noise classification experiments are conducted wherein a support vector machine algorithm (SVMstruct) and a decision tree learning algorithm (C4.5) are used as the classifiers. Several features are used for the classification, including the conventional mel-frequency cepstral coefficient (MFCC) features as well as DCT-based and spectral features derived from the proposed FFT-based spectra. Compared to the conventional features, the auditory-related features show more robust performance in mismatched test cases. Test results also indicate that the performance of the proposed FFT-based auditory spectrum is slightly better than that of the original auditory spectrum, while its computational complexity is reduced by an order of magnitude. / Finally, to further explore the proposed FFT-based auditory spectrum from a practical audio classification perspective, a floating-point DSP implementation is developed and optimized on the TMS320C6713 DSP Starter Kit (DSK) from Texas Instruments.