Thesis (MTech. degree in Policing) -- Tshwane University of Technology, 2010. / Looks at the causes for poor investigation of murder cases in Loate police station and seek ways which would assist in improving the investigation of murder cases.

published_or_final_version / Zoology / Master / Master of Philosophy

In order to establish a method of assessing the degree of inbreeding within herds of cattle, we constructed a calibration index relating kinship and the degree of DNA band sharing in DNA fingerprints. Firstly, chickens were used as a model system to test the possibility of using microsatellite DNA as a probe for DNA fingerprinting in inbreeding analysis. Six genetic groups of chickens with estimated coefficients of inbreeding ranging from 0.026 to $>$ 0.98 (pedigree analysis) were fingerprinted using the minisatellite probe derived from M13 and the microsatellite probe (CAC)$ sb5$. The degree of band sharing using either probe increased in concert with the known amount of inbreeding and was described by the equation Y = 0.56X ($ pm$0.06) + 0.42 ($ pm$0.03); r = 0.998. Since in-gel hybridization using the microsatellite probes was faster and less labour intensive than using the minisatellite probe, it was used in the subsequent studies. Pedigree analysis in Holstein dairy cattle allowed for the empirical calibration of the association of band sharing with the coefficient of relatedness, (r), defined as the expected proportion of genes in 2 individuals that are identical by descent (i.e. for monozygous twins r = 1; for first order relatives r = 0.5; for half sibs r = 0.25 etc.). The average band sharing between pairs (6 pairs at each r value) of individuals within each class formed the basis for calibration. DNA was digested using RsaI. The relationship between band sharing and relatedness was well represented by a linear approximation Y = 0.51X ($ pm$0.09) + 0.50 ($ pm$0.04); r = 0.992. Using this calibration curve, random samples of animals within herds can be tested to establish the herd variability and to minimize inbreeding.

Environmental liability cases involving spilled or released petroleum products into ocean ecosystems require oil identification techniques that are unambiguous and conclusive, even in situations where oils have been subjected to secondary environmental processes, such as, evaporation and dissolution. The ability and functionality of the Compound Specific Isotope Correlation (CSIC) technique is tested to determine its reliability to characterize released petroleum using the carbon isotope ratios (13C/12C) of the individual gasoline-range compounds (C5-C9). In particular, this thesis studies the potential of CSIC as a robust diagnostic tool, to identify and correlate marine releases of oil with their sources, especially those having undergone evaporative weathering. Three crude oils (Alberta Sweet Mixed Blend, Lacula and Louisiana) added to synthetic seawater were exposed to mechanically simulated wave energy and controlled evaporative weathering at 10 oC. Time-series sampling of the gasoline-range vapour fractions from the headspace employed Solid Phase Micro Extraction (SPME). SPME-Continuous Flow-Isotope Ratio Mass Spectrometry (SPME-CF-IRMS) determined the molecular abundances and stable carbon isotope ratios (δ13C) of the gasoline-range compounds of the original and weathered oils. Evaporation rates over the maximum 20 hour period varied for the 3 study oils. Most (74%) of the individual compounds measured in the oils display a δ13C enrichment with progressive evaporation with approximately half of the compounds in all 3 oils showing fractionation of the carbon isotopes ≤ 0.5‰ within measurement precision. The magnitude of carbon isotope shift observed in compounds pre-vs. post-weathering ranges from 0 to 2.8 ±0.6‰. There is no clear relationship identified between the degree of 13C enrichment in the oils and groupings such as chemical class, structure or carbon number. The overall weighted average 13C enrichment for all compounds in the 3 oils is approximately 1‰. Toluene was the only compound consistently exhibiting comparatively high 13C enrichment (1.6‰, 1.8‰ and 2.8‰) in all 3 oils after evaporative weathering. Hierarchical Cluster Analysis (HCA) treatment of the CSIC data set can reliably discriminate between the 3 oils despite evaporative weathering and δ13C changes. HCA is also able to unambiguously relate the three weathered oils back to their respective original unweathered oil. Diagnostic shifts in δ13C of individual compounds in an oil may potentially be used to trace weathered oils back to the source, and possibly give a estimation of time since release. However the typically rapid rate of evaporation for the gasoline-range fractions limits the time that an oil can be successfully identified by CSIC. / Graduate

A concern in transgenic crops is the potential risk posed by unintended effects which could result from genetic transformation. The objective of this work was to develop an untargeted approach that could characterize transgenic crops, as well as conventional crops, at the molecular level. An experimental approach was designed and used to compare conventional and transgenic soybean varieties. Varieties were compared using their metabolite fingerprints obtained by reverse-phase high performance liquid chromatography (HPLC) and both the analytical and biological variability were assessed. Multivariate and univariate statistical analyses were applied to the data to detect significant differences between the varieties. It was found that transgenic variety PS 46 RR was the most different variety analyzed and that it differed most from Mandarin (Ottawa) and AC Dundas. The statistical analyses also determined that PS 46 RR differed more from the conventional varieties tested than 2601R did.

The effectiveness of location aware applications is dependent on the accuracy of the supporting positioning system. This work evaluates the accuracy of an indoors 802.11 positioning system based on signal strength fingerprinting. The system relies on an empirical survey of signal strength prior to positioning. During this survey, signal strength recordings are made at a set of positions across the environment. These recordings are used as training data for the system during positioning. In this thesis, two surveying methods, five positioning algorithms, and two spatial output averaging methods are trialled. Accuracy is determined by empirical testing in two separate environments: a 100m square domestic house and the 1,333m square third floor of the University of New South Wales Computer Science and Engineering building. In the two environments, the lowest mean distance errors are 1.25m and 2.86m respectively.

Thesis (MSc)--University of Stellenbosch, 2007. / Bibliography. Also available via the Internet

Thesis (Ph. D.)--Washington State University, August 2008. / Includes bibliographical references.

Thesis (M.S.)--Michigan State University. School of Criminal Justice, 2008. / Title from PDF t.p. (viewed on Aug. 7, 2009) Includes bibliographical references (p. 52-54). Also issued in print.

Thesis (Ph. D.)--University of North Texas, Dec., 2008. / Title from title page display. Includes bibliographical references.