Over recent years, the application of assisted reproductive techniques in the treatment of infertility has increased exponentially, yet these methodologies still remain inherently inefficient. It has long been established that the single greatest obstacle to improving the success of these treatments is determining the quality of the oocytes used. However, currently the methods available for oocyte assessment are mainly qualitative, and suffer due to a lack of standardisation. As such, the efficiency of fertility treatments could benefit from the introduction of a rigorous quantitative measure of oocyte quality and maturation. The principal aim of this thesis was to determine the potential of Raman spectroscopy when applied to the field of oocyte biology. Consequently, this thesis addressed three main areas of investigation: I. the intra-oocyte biochemical variation; II. the biochemistry of oocyte maturation; and finally, III. the effect of environment on the mature oocyte in vivo and in vitro. I. To investigate the presence of intra-oocyte biochemical variation, oocytes from various stages of development were analysed using high resolution Raman mapping, in combination with univariate and multivariate analysis. Images revealed variation between the germinal vesicle and ooplasm in immature oocytes, as well as intra-ooplasmic variation in all oocytes. II. The spectral analysis of oocytes derived from pre-antral and in vitro cultured follicles revealed significant variation: It was found that Raman spectroscopy could successfully discriminate between immature and mature oocytes. III. Finally, the spectral analysis of oocytes derived from unstimulated and stimulated ovulation cycles, as well as those derived from in vitro follicle cultures, revealed that although biochemically similar, in vitro matured oocytes demonstrated reduced protein content. Furthermore, greater spectral variation was observed in superovulated oocytes, which was found to describe the corresponding morphological quality. In conclusion, this thesis has demonstrated the effective application of Raman spectroscopy to the study of fixed murine oocytes. Raman mapping experiments have demonstrated this technique for the visualisation of biochemical variation which exists within the oocyte. Furthermore, using Raman spectroscopy, the identification of the biochemical variation resulting from different maturation mechanisms has been achieved, as has the discrimination of immature and mature oocytes. These results indicate that Raman spectroscopy holds promise as a quantitative analysis method in the field of fertility treatment.

No description available.

Thesis submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Faculty of Engineering and the Built Environment, School of Chemical and Metallurgical Engineering, University of the Witwatersrand, Johannesburg, 2017 / Three medium rank C coals and a discard coal from different coalfields within the Karoo Basin were investigated. In this study, physico-chemical properties, ash fusion tests, quantitative single particle -electron probe X-ray microanalysis (SPAEPXMA), petrography, X-ray diffraction (XRD), Fourier Transform Infrared (FTIR), and micro-Raman spectroscopy (mRs) were used as analytical techniques of choice to investigate the heterogeneous nature of coals, including mineralogical structure, mode of occurrence, and association of mineral matter in coals. The aim of the work was to highlight the significance of understanding the heterogeneous nature of coals, and to develop comprehensive and reliable approaches of characterising coals, coal ashes, and predict the behaviour of coals in coal conversion processes. The FTIR technique identified a well ordered kaolinite of authigenetic origin, characterised by inner hydroxyl group with H2O vibration at 3618 cm-1 absorption bands as the major mineral. Smectite and muscovite were identified at peaks 797 cm-1 and 799 cm-1 respectively, with quartz confirmed by the υ (Si-O-Si) and δ (Si-O) bands. The SPA-EPXMA data, modelled using principal component analysis (PCA) and chemical boundary classification (CBC), identified a diverse range of minerals such as alunite, chlorite, fayalite, almandine, anatase, ilmenite, brushite, goyazite, gypsum, dolomite, calcite, sodalite, rhodochrocite, and halite in raw coal samples. The mRs technique showed that in addition to bassinite, other oxidation products that formed at low temperature included lepidocrite and coquimbite. The technique proved to be ideal for the characterisation of high temperature ashes. High spatial resolution of mRs confirmed the presence of mixtures of anatase, brookite, and rutile, hematite, nephaline, apatite, crednerite and apatite in high temperature ashes. The SPA-EPMXA and mRs technique probed minerals on a micro-scale and their application could be extended to prediction of slagging and fouling behaviour in coals. The multiple technique approach revealed the importance of using a combination of techniques to characterise coals, and provided useful information that can help understand and relate the mineralogical and elemental composition of coals. This knowledge could be useful in designing conversion processes, and necessary downstream manipulations. / XL2018

Graduation date: 1994

Thesis (M.S.)--Oregon Graduate Center, 1976.

Thesis (Ph. D.)--Oregon Graduate Center, 1979.

M.S. / Applied Physics / This monograph summarizes the theory and construction of a tunable continuous wave (CW) Rhodamine 6G dye laser longitudinally pumped by an argon laser. (from Introduction; no abstract available)

Graduation date: 1991

Graduation date: 1991

No description available.