Iron (Fe) exerts strong control over environmental biogeochemistry. As the fourth most abundant element, Fe is present in nearly all earth environments, where it plays important roles in governing the transformation and movement of organic and inorganic constituents, and in microbial respiration. Consequently, the body of work on Fe biogeochemistry is vast. This study is specifically concerned with the dynamic changes in the oxidation state of Fe (i.e., redox cycling) and their impact on the inorganic, organic and microbial components in soil. I constructed a special apparatus to fluctuate redox potential on soil slurries while concurrently sampling a wide range of biogeochemical variables (pH, redox potential, major and trace elements, CO2 release, DNA community composition charges, etc.). Previous research has documented redox fluctuations along a climate gradient in Hawaii and a primary goal of this dissertation was to reconstruct these redox fluctuations, subjected to experimental constraints afforded by a laboratory setting, with minimal disruption to the biogeochemical processes controlling Fe redox cycling. By recasting the spatial and temporal characteristics of in situ Fe redox cycling in the laboratory, I was able to form testable hypotheses regarding the importance of Fe redox oscillations to soil mineral transformations, colloid composition/dynamics and microbial community structure. A second goal of this dissertation was to explore the utility of Fe isotopic composition for providing information on soil weathering processes along age and climate gradients at the field scale in Hawaii. This portion of the study tested emerging theories of Fe isotope fractionation during mineral dissolution using well-characterized sequences in soil weathering intensity.The principal findings of the laboratory redox fluctuation experiments are that Fe redox oscillations: (1) trigger an increase in the crystallinity of Fe-oxides; (2) mobilize colloids containing refractory elements (e.g., Zr, Nb, U, etc.); (3) reveal redox sensitive rare earth element (REE) anomalies in the aqueous phase; and (4) induce changes in the microbial community favoring microbes capable of growth under both oxic and anoxic conditions. The principal finding of the Fe isotope measurements is that isotopic composition is directly related to weathering intensity in the field, consistent with theoretical predictions.

DNA fingerprinting was used to assess levels of genetic variation within the captive colony of pedigreed American kestrels (Falco sparverius) which have been maintained for over twenty years at the Avian Science and Conservation Centre of McGill University. Several instances of apparent linkage and allelism were observed. The high probability of fortuitous co-segregation of parental bands as if linked or allelic resulting from the small number of offspring was most likely responsible. Otherwise, the kestrel fingerprints displayed germ-line stability and high levels of heterozygosity characteristic of other species. A positive linear and quasi-linear relationship was found between pedigree-based and DNA fingerprint-based relatedness coefficients. High levels of genetic variation and minimal inbreeding were detected via genetic analyses. Genetic similarity coefficients between colony-bred and free-ranging American kestrels were not significantly different (P $>$ 0.5), indicating minimal genetic drift within the colony. Managed mating combined with immigration of new members into the breeding pool can maintain genetic diversity within a captive population of 200 to 300 American kestrels for a long term management scale. The captive-bred kestrel population can be fully exploited for general research, management and care techniques and as a genetic and demographic reservoir.

The technique of restriction fragment length polymorphism (RFLP) analysis, of chloroplastic and genomic DNA, was investigated as a means of identifying eucalypt species and cultivars which are morphologically indistinguishable from one another. In order to resolve chloroplast DNA (cpDNA) RFLPs, a method was developed to extract high yields of intact chloroplasts from Eucalyptus grandis S/N M6. Starch contamination was reduced by incubation of saplings in the dark for 48 h prior to extraction and watering with a solution containing 370 mM Na-phosphate and 296 mM KN03. Optimal chloroplast yields (25 ug chlorophyll/g fresh mass) were obtained by chopping leaf material, using a vertical homogenizer, in a buffer containing 350 mM sorbitol, 50 mM tris-HCL and 5 mM EDTA, 0.1 % (w/v) bovine serum albumin, 0.15 % (w/v) 2-mercaptoethanol, 2 mM L-ascorbic acid and 1 mM MgCI2 followed by washing of leaf pieces in a buffer containing only sorbitol, tris-HCL and EDTA. When these chloroplasts were used in an "in-organelle" DNA digestion procedure, polymorphisms were observed between the cpDNA profiles resolved for E. grandis S/N M6 and that of an outgroup species (spinach). However, the developed chloroplast extraction technique could not be used to obtain chloroplasts from various other eucalypt species, probably as a result of variability in the material at an ultrastructural or biochemical level. For the analysis of genomic DNA RFLPs, a DNA extraction procedure was optimized for use with various eucalypt species and cultivars. This included the development of a purifcation technique during which DNA was ammonium acetate-ethanol precipitated and subjected to mini-dialysis. Following Dra I restriction of DNA, the extract was electrophoresed and Southern blotted onto both nylon and nitrocellulose membranes. These were probed with a Hind-III restricted sample of the multilocus plasmid probe pV47-2. This probe was labelled using 32p as well as a non-radioactive labelling substance digoxygenin (DIG). Hybridization conditions, including the composition of the hybridization buffer, were optimized for use with these labels, and DNA RFLPs (fingerprints) were resolved for the eucalypt species E. grandis and E. macarthurii and cultivars of E. grandis (S/N M6, TAG 5 and TAG 14). An average of 8.5 bands were detected with 32p and 5.0 fragments with DIG. All the species and cultivars fingerprinted with the 32P-label could be distinguished from one another. However, as a result of the reduced sensitivity of the DIG system, two of the E. grandis cultivars, S/N M6 and TAG 5, could not be differentiated. It is concluded that the latter system would be most suitable for incorporation into a routine eucalypt screening programme, although it is suggested that the colourimetric detection assay, used in this study to resolve DNA bands, be replaced by a more sensitive one. / Thesis (M.Sc)-University of Natal, Durban, 1993.

The purpose of this research endeavor was to determine the extent of genetic relatedness between an ancient and modern Miami Indian population. The modern Miami Indian nation in Indiana is currently in the process of regaining the federal recognition which was lost in the mid 1800's when part of the tribe was forced to relocate. A close genetic relationship between a modern and known ancient population could considerably strengthen the case to regain federal recognition. The human skeletal remains used for this experiment were excavated after partial exposure by flooding between 1989-1993 along the banks of the Mississinewa River in Wabash County. Through ethnohistoric dating techniques, the remains have been shown to represent a Miami Indian population living between 1790-1820. In order to yield amplifiable DNA several methods of isolation were attempted and compared. CTAB and phenol/chloroform/isoamyl alcohol (24:24:1) and a silica based purification method provided the best results yielding approximately 50-100 ng of amplifiable DNA from 3 of the 4 individuals. Purification of the DNA was found to be necessary following both isolation (Elu-Quik) prior to PCR amplification and after PCR but prior to sub-cloning(Gene-Clean). Regions of the mitochondrial DNA (mtDNA) genome of isolated DNA were amplified using primers which are specific for the HIizcIl and AIui regions of the mtDNA genome. Although the mtDNA proved to be somewhat amplifiable, it was still too fragmented to be cloned, which prevented genetic analysis and comparison of the two populations. As a result, a discussion of alternative methods for looking at relatedness between populations has been included. / Department of Biology

<p>The aim of this study was to investigate the forensic usefulness of various Y-chromosome short tandem repeat loci among South African sub-populations. Three different sets of Y-chromosome short tandem repeat loci were chosen for investigation.</p>

Thesis (Ph.D) -- McMaster University, 1999. / Includes bibliographical references [leaves 52-53]. Also available via World Wide Web.

Thesis (M.S.)--Michigan State University. School of Criminal Justice, 2006 / Title from PDF t.p. (viewed on Nov. 20, 2008) Includes bibliographical references (p. 112-116). Also issued in print.

Thesis (Ph. D.)--Virginia Polytechnic Institute and State University, 1993. / Vita. Abstract. Includes bibliographical references (leaves 109-117). Also available via the Internet.

Thesis (Ph. D.)--Ohio University, August, 2004. / Includes bibliographical references (p. 185-196).

Thesis (doctoral)--Universität Regensburg, 2009. / Includes bibliographical references.