The global movement of aquatic non-indigenous species can have severe ecological, environmental and economic impacts emphasizing the need to identify potential invaders and transport pathways. Initial transport is arguably the most important stage of the invasion process owing to its role in selectively determining potential invasion candidates. This study characterizes a well defined human-mediated dispersal mechanism, ballast water transport, as a vector for the introduction of non-indigenous zooplankton. Ballast water exchange in the open ocean is the most widely adopted practice for reducing the threat of aquatic invasions and is mandatory for most foreign vessels intending to release ballast in Canadian waters. Ships entering Canadian ports are categorized into the following three shipping classes based on current regulations: overseas vessels carrying exchanged ballast water, intra-coastal vessels carrying exchanged ballast water or intra-coastal vessels carrying un-exchanged ballast water. This study characterizes zooplankton communities associated with each of these shipping classes sampled from ports on Canada’s Pacific coast, Atlantic coast and the Great Lakes Basin. Ballast water samples were collected and analyzed from 77 vessels between 2006 - 2007. The ballast water environment was found to be diverse, with over 193 zooplankton taxa, 71 of which were non-indigenous to their receiving environments. Intracoastal vessels containing un-exchanged coastal water transported the greatest density of non-indigenous zooplankton into Canadian ports. Total zooplankton density was found to be negatively correlated with ballast water age The absence of mandatory ballast water exchange and the younger ballast water age of coastal un-exchanged vessels is likely responsible for the higher density of non-indigenous zooplankton in intracoastal un-exchanged vessels. Propagule pressure, invasion history and environmental suitability are all useful in evaluating invasion potential and all suggest that intracoastal un-exchanged vessels pose the greatest invasion threat to Canadian aquatic ecosystems. In conclusion, although the risk of primary introductions from overseas ports may have been reduced through open-ocean exchange of ballast water, secondary introductions from previously invaded ports in North America may be the primary threat to Canadian aquatic ecosystems via this transport vector.

Though British singer Dusty Springfield had a very prominent and successful career, she is often left out of the history books. Her North American legacy has been reduced to her album Dusty in Memphis, an inaccurate and incomplete representation of Dusty Springfield’s career. Many aspects of her career are largely ignored, for scholars put her sexuality, her ability to “sound black,” and the influence of black musicians at the forefront of Dusty Springfield scholarship. The purpose of this project is to highlight influential musicians, experiences, and talents which have been left out of Dusty Springfield studies. This thesis focuses on Dusty Springfield’s performance experiences, her songwriting abilities, her audience/performer dichotomy, and various people and styles that have influenced her persona. By examining the artists and experiences that influenced her career, this thesis explores the ways in which persona is constructed and how it functions in the pop music industry.

Cell migration and invasion are essential physiological processes required for the growth and development of all multicellular organisms. However, they have also been implicated in the pathogenesis of certain vascular system diseases and invasive cancers. In this study, we investigate two proteins involved in cell proliferation and survival signaling, p53 and Stat3, which have been found misregulated in atherosclerosis and cancer, to establish what effect they have on the development of Src-induced invasive phenotypes in aortic vascular smooth muscle cells (VSMC) and NIH 3T3 fibroblasts. In the first stage of this experiment, we investigated the tumor suppressor p53. Once believed to act primarily as a regulator of the cell cycle, DNA repair, senescence and apoptosis, current evidence suggests that p53 can also regulate cell migration and invasion. For our study, we stably transduced VSMC and NIH 3T3 fibroblasts with constitutively active Src (SrcY527F) to generate invasive cell lines with pronounced podosome and rosette formation. We established for the first time that p53 suppresses Src-induced podosome and rosette formation, extracellular matrix degradation, cell migration and invasion in these cells. We also present novel data showing that p53 suppresses these invasive phenotypes, at least in part, by up-regulating the expression of caldesmon, an actin binding protein which stabilizes stress fibers and inhibits podosome and rosette formation. In the second part of this study, we show that Stat3, a pro-survival and pro-metastatic transcription factor, is required downstream of Src for the promotion of invasive phenotypes in VSMC and NIH 3T3 fibroblasts. Interestingly we have also shown for the first time that Stat3 can localize to podosomes and rosettes in these cells. The exact physiological reasoning for this localization, however, remains to be determined. This study provides strong evidence suggesting that mutual antagonism between the anti-invasive ‘p53-caldesmon’ and pro-invasive ‘Src-Stat3’ pathways dictates the outcome of Src-induced invasive phenotypes in VSMC and NIH 3T3 fibroblasts. / Thesis (Master, Biochemistry) -- Queen's University, 2010-01-09 21:57:30.056

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Biological invasions pose a serious threat to biodiversity world-wide. Through various means, such as competition or predation, invaders can radically change species composition and the functioning of native ecosystems. Even though our understanding of the mechanisms underlying invasion success is improving, there is still a lack of knowledge on the response of native species under pressure from invasion. This study adds to existing knowledge on the responses of a native species to invasion by non-indigenous species. Pyura pachydermatina is a native ascidian in the southeast coast of New Zealand currently under pressure from increased urbanisation and invasion by other ascidian species. The reproductive strategies employed by P. pachydermatina are investigated and the role of these strategies to increase its resistance to invasion are assessed. A population study on the status of P. pachydermatina around the Banks Peninsula was carried out in Camp Bay, Pigeon Bay, and Wainui. Spawning experiments using P. pachydermatina and gonad histology were done regularly during the one year study period to assess its ability to self-fertilise and determine its reproductive period. In addition, predation experiments were carried out to assess the susceptibility of P. pachydermatina early life stages to two amphipod predators. The surveys indicated that the populations of P. pachydermatina in the three sites are different from one another. Wainui has on average the largest individuals of P. pachydermatina and Camp Bay, the smallest. Abundance of P. pachydermatina was highest in Pigeon Bay and lowest in Wainui. The three life stages of Pyura pachydermatina; recruits, juveniles, and adults, were present in all sites at all seasons. The spawning experiments confirmed the species’ ability to self-fertilise and that it has a year-round spawning period. The two amphipod predators, Jassa marmorata and Caprella mutica, were efficient in consuming the egg and larval stages of P. pachydermatina, but did not feed on the settlers. Year-round reproduction and the ability to self-fertilise potentially give P. pachydermatina increased resistance to the effects of urbanisation and invasion. This population study suggested that the species is thriving around the Banks Peninsula. This, combined with previous studies on the non-indigenous ascidian Styela clava that stated the static or declining populations of the potential invaders, gives a positive outlook for the native species for the future. I suggest the use of genetic techniques to assess, in more detail, the population structure and dispersal potential of this native species. I also suggest constant monitoring of native species is required to keep up to date with the current status of the species, which will in turn help management decisions should regional spread of the Lyttelton S. clava invasion occur in the future.

The metastasis suppressor gene NM23-H1 has been shown to possess three enzymatic activities including nucleoside diphosphate kinase, histidine-dependent protein kinase and 3’-5’ exonuclease activity. While these properties have been demonstrated in vitro using recombinant proteins, the contribution of these activities to suppression of metastatic dissemination is unknown. Site-directed mutagenesis studies were used to identify amino acid residues which are required for proper function of each enzymatic activity associated with H1, providing a platform for studying the importance of each function on an individual basis. To assess the relevance of these activities to melanoma progression, a panel of mutants harboring selective lesions disrupting the enzymatic activities of H1 were overexpressed using stable transfection in two melanoma cell lines, WM793 (isolated from a vertical growth phase human melanoma), and the metastatic derivative cell line 1205LU. In vitro correlates of metastasis measuring motility and invasion were used in an attempt to identify the mechanism mediating H1-dependent motility suppression of cancer cells. Surprisingly, all mutants studied retained full motility suppression in this setting, suggesting that the enzymatic functions associated with H1 are not required for inhibiting cell migration. Instead, gene expression analyses conducted on the panel of stable transfectants indicate that differences in steady-state mRNA levels of genes involved in mitogen-activated protein kinase (MAPK) signaling showed significant correlations with H1 expression and motility suppression. RNAi studies have confirmed that H1-dependent modulation of the expression of two genes in particular, BRAP and IQGAP2, contribute to the observed phenotype, suggesting a novel mechanism used by NM23 to control cellular migration in human melanoma.

A Deep Geologic Repository is proposed for a site on the eastern margin of the Michigan Basin at a depth of 680 metres in the Cobourg Formation. A study of the paleo-hydrogeolgical conditions for the area was conducted using numerical simulation of the distribution of natural tracers and the observed hydraulic head. To conduct the study, simulations of the groundwater flow systems were developed for hydraulic head generated from glacial loading cycles to study its effects on advective solute transport. The hydro-mechanical loading during the glacial cycles is assessed using numerical analysis of coupled stress and porewater pressure. The effect of density-dependent flow was assessed in a second study to estimate the degree of penetration of glacially-derived water driven into the basin during periods of glacial loading. Numerical simulations were used to explore the potential freshwater invasion pathways under a variety of conditions. Finally, profiles of 18O and 2H measured in porewater were combined with our understanding of the paleo-hydrogeological conditions derived from the studies above to test the hypothesis that solute transport was diffusion-dominated in this setting. A series of pure diffusion and advection-diffusion models were developed and the results were compared with profiles of natural water isotopes obtained from the study area. The results of the hydro-mechanical study of glacial impact show the development of significant underpressure during the interstadial periods, especially in the lowest permeability formations. The results also show that the formations have not reached hydrostatic conditions at the present time. These results were verified by comparison to measured environmental heads obtained from the study site. The density-dependent modeling showed that freshwater is capable of reaching the location of the study site through several permeable features. The transport simulations showed that the evolution time starting from a uniform initial condition, and using boundary conditions that are defined by freshwater invasion at several depths agrees with the hydro-geological history of this part of the Basin. The results also show the importance of advection on solute transport from the upper and lower boundaries even in rock of extremely low permeability. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2014-05-30 10:18:01.286

Cancer is a complex, multi-scale disease marked by unchecked cellular growth and proliferation. As a tumor grows, it is known to lose its capacity to maintain a compact structure. This stage of development, known as invasion, is marked by the disaggregation and dispersion of peripheral cells, and the formation of finger-like margins. This thesis provides an overview of three multi-scale models of tumor growth and invasion. The hybrid discrete-continuum (HDC) model couples a cellular automaton approach, which is used to direct the behavior and interactions of individual cells, with a system of reaction-diffusion-chemotaxis equations that describe the micro-environment. The evolutionary hybrid cellular automaton (EHCA) model maintains the core of the HDC approach, but employs an artificial response network to describe cellular dynamics. In contrast to these two, the immersed boundary (IBCell) model describes cells as fully deformable, viscoelastic entities that interact with each other using membrane bound receptors. As part of this thesis, the HDC model has been modified to examine the role of the ECM as a barrier to cellular expansion. The results of these simulations will be presented and discussed in the context of tumor progression.

The global movement of aquatic non-indigenous species can have severe ecological, environmental and economic impacts emphasizing the need to identify potential invaders and transport pathways. Initial transport is arguably the most important stage of the invasion process owing to its role in selectively determining potential invasion candidates. This study characterizes a well defined human-mediated dispersal mechanism, ballast water transport, as a vector for the introduction of non-indigenous zooplankton. Ballast water exchange in the open ocean is the most widely adopted practice for reducing the threat of aquatic invasions and is mandatory for most foreign vessels intending to release ballast in Canadian waters. Ships entering Canadian ports are categorized into the following three shipping classes based on current regulations: overseas vessels carrying exchanged ballast water, intra-coastal vessels carrying exchanged ballast water or intra-coastal vessels carrying un-exchanged ballast water. This study characterizes zooplankton communities associated with each of these shipping classes sampled from ports on Canada’s Pacific coast, Atlantic coast and the Great Lakes Basin. Ballast water samples were collected and analyzed from 77 vessels between 2006 - 2007. The ballast water environment was found to be diverse, with over 193 zooplankton taxa, 71 of which were non-indigenous to their receiving environments. Intracoastal vessels containing un-exchanged coastal water transported the greatest density of non-indigenous zooplankton into Canadian ports. Total zooplankton density was found to be negatively correlated with ballast water age The absence of mandatory ballast water exchange and the younger ballast water age of coastal un-exchanged vessels is likely responsible for the higher density of non-indigenous zooplankton in intracoastal un-exchanged vessels. Propagule pressure, invasion history and environmental suitability are all useful in evaluating invasion potential and all suggest that intracoastal un-exchanged vessels pose the greatest invasion threat to Canadian aquatic ecosystems. In conclusion, although the risk of primary introductions from overseas ports may have been reduced through open-ocean exchange of ballast water, secondary introductions from previously invaded ports in North America may be the primary threat to Canadian aquatic ecosystems via this transport vector.