Histone H2A.Z is a highly conserved replication-independent histone variant that is essential for survival in diverse organisms including Tetrahymena thermophila, Drosophila melanogaster, Xenopus laevis, and Mus musculus. H2A.Z has been shown to play a role in many cellular processes including, but not limited to, gene expression, chromosome segregation, cell cycle progression, heterochromatin maintenance and epigenetic transcriptional memory. However, the mechanism by which H2A.Z and its post-translationally modified forms participate in these diverse cellular events and their subsequent effects on chromatin structure and function are not entirely clear. A thorough review of H2A.Z is provided in Chapter 1. We have isolated native non-acetylated and acetylated forms of H2A.Z and characterized nucleosome core particles (NCPs) reconstituted with these proteins using the analytical ultracentrifuge (Chapter 2). We report that NCPs reconstituted with native non-acetylated H2A.Z exhibit a slightly more compact conformation compared to those reconstituted with H2A. Furthermore, we show that acetylation of H2A.Z in conjunction with acetylation of the histone complement, results in NCPs that are less compact and less stable than H2A.Z-containing NCPs reconstituted with non-acetylated histones. Acetylated H2A.Z NCPs are nevertheless more compact and stable than acetylated H2A-containing NCPs. We have also identified the presence of two H2A.Z protein isoforms in vertebrates, H2A.Z-1 and H2A.Z-2, and characterized the sites and abundances of their N-terminal peptide acetylation. Further characterization of the human H2A.Z isoforms is presented in Chapter 3 and indicates that they are expressed across a broad range of human tissues, and that they exhibit a similar but non-identical distribution within chromatin. Our results suggest that H2A.Z-2 preferentially associates with H3 trimethylated at lysine 4 compared to H2A.Z-1, and the phylogenetic analysis of the promoter regions of H2A.Z-1 and H2A.Z-2 indicate that they have evolved separately during vertebrate evolution. Overall, these data suggest that the two isoforms of H2A.Z present in vertebrates may have acquired a degree of functional independence. In Chapter 4, we show that H2A.Z and an N-terminally acetylated form of H2A.Z associate with the prostate specific antigen (PSA) gene promoter and the levels of these proteins are reduced upon induction of the gene with androgen. Furthermore, H2A.Z protein levels increase in response to treatment with androgen which correlates with an increase in the mRNA expression levels of the H2A.Z-1 gene. Preliminary Western Blot and quantitative PCR analysis of H2A.Z (-1 and -2) levels in a tumor progression model of prostate cancer indicate that increased H2A.Z expression may be involved in the development of androgen independent prostate cancer. Collectively, our results contribute to our understanding of H2A.Z biology in vertebrates and support a role for this protein and its acetylated forms in poising promoter chromatin for subsequent gene transcription.

This thesis focuses on one of the key development areas of Beyond IMT-2000 or Beyond 3rd Generation (B3G) systems recommended by ITU-R M.1645, that is, new radio access systems that provide significantly higher performance for different deployment scenarios which may encompass different access technologies while maintaining seamless access and mobility from the user's perspective. Our objective is to develop various Medium Access Control (MAC) solutions for this new B3G access system. We introduce a novel B3G multi-mode access system framework based on heterogeneous physical layer (PL) modes or configurations, anchored by a common layer 2 and layer 3 protocol stack. Such a system can support a wide variety of physical layer multiple access technologies to target different deployment scenarios and performance targets. The anchor or common layer 2/3 protocols enable seamless handoff and dynamic radio resource/load/spectrum management across the different PL modes to achieve optimum spectrum efficiency and Quality of Service (QoS) support. As a basic form of the proposed B3G multi-mode access system and the first evolution step from the existing 3rd Generation (3G) cellular systems, we propose the multi-carrier expansion of Direct Spread Code Division Multiple Access, i.e. MC DS-CDMA. MC DS-CDMA supports concurrent transmissions on multiple DS-CDMA carriers anchored by a common layer 2/3 protocol stack. The common layer 2/3 protocol stack supports fully asymmetrical and dynamic Forward Link (FL) and Reverse Link (RL) carrier(s) allocation based on QoS requirements and Service Level Agreement (SLA). MC DS¬CDMA also provides backward compatibility to existing single carrier DS-CDMA systems, thus allowing for overlay of legacy and new systems while the network deployment migrates towards B3G broadband support. We further investigate load balancing schemes across multiple PL modes sharing the same spectrum resource in Time Division Multiplex (TDM), Frequency Division Multiplex (FDM) or Code Division Multiplex (CDM) fashions. For TDM and FDM cases, we propose a new Integrated Load Balancing and Scheduling (ILBS) scheme that maximizes the system capacity while meeting users' QoS and SLA. For the CDM case, we propose a dynamic Walsh code and Base Station (BS) transmit power sharing scheme between power-controlled dedicated traffic channels and rate-controlled packet data channels across multiple CDMA carriers. An important aspect of MAC for wireless mobile systems is the MAC states management. We develop a universal MAC state machine concept that anchors the heterogeneous PL modes so that when a user switches from one PL mode to another, the MAC state and the associated context information of the MS can be retained. to minimize packet loss and PL mode switching/handoff latency. We further look into the decision criteria used to transition a user from one MAC state to another. It is an important part of MAC for both the existing 3G systems and the B3G systems. The decision criteria should aim to maximize system capacity while meeting users' QoS and SLA requirements, while at the same time achieving power-saving. We propose a novel priority based state transition algorithm that achieves these objectives. Overall, our research provides key solutions to the challenges of next generation wireless systems envisioned to encompass heterogeneous characteristics and performance targets.

The snowball Earth theory. that low-latitude continents became glaciated after sea ice extended from the poles to the equator during the Neoproterozoic (1000 - 545 Ma), has sparked a flood of numerical modelling studies investigating all phases of the proposed extreme climatic cycle. Modelling studies have both supported and refuted the original ‘hard’ snowball theory, as well as offered alternative theories such as the ‘soft’ snowball theory, where glaciers covered all land masses but sea ice did not extend equatorward of -25° latitude. Presented here are a number of sensitivity studies investigating the effects of different sea ice models on snowball inception and how large ranges in accepted albedo values affect the amount of radiative forcing required for deglaciation. These experiments shed light on disparities between previous modelling results. This study demonstrates the importance of a sea ice component's thermodynamic formulation by comparing the physically complete thermodynamic sea ice model in the UVic Earth System Climate Model to an incomplete sea ice model used in an early version of the Fast Ocean Atmosphere Model. As well as the importance of a sound thermodynamic sea ice model is the inclusion of sea ice dynamics. Sea ice dynamics have not previously been included in snowball simulations and their inclusion suggests that the alternative `soft' snowball theory may not be plausible. With a purely thermodynamic sea ice component. the 'soft' snowball state is stable whereas with the inclusion of sea ice dynamics it is not. Also gained from this study was the influence of wind speed on the level of CO2 required to produce a hard snowball solution: greater wind speed results in a cooler ocean and easier snowball inception. Finally, although albedo values are critical for the albedo feedback that initiates snowball inception, they are even more important for determining the amount of radiative forcing required to deglaciate the snowball Earth, as the entire planet is covered by snow and ice. Through a suit of sensitivity studies, the amount of forcing required to deglaciate a hard snowball Earth is found to be extremely sensitive to the snow albedo, sea ice albedo and snow masking depth.

Wilms' tumor suppressor protein (WTI) is a key regulatory factor involved in controlling the development and normal physiology of the genitourinary tract. Mutations within WT1 result in multiple syndromes affecting the kidney and gonads with the most severe effects being Wilms' tumor, a pediatric kidney cancer. The WTI protein is composed of two distinct functional domains; the amino terminus is a proline and glutamine rich regulatory domain, while the carboxyl terminus is a DNA binding domain which contains four C2H2 zinc fingers. Although the zinc finger motif is small in size, proteins containing zinc fingers are extremely diverse in their functions. The functional diversity of WT1 is exemplified through its interactions with a wide range of ligands, such as DNA, RNA and proteins. The interaction between WT1 and DNA has been well characterized, while the interactions with RNA and proteins still require intensive investigation. Recent studies have identified a diverse group of WT1 protein partners but the characterization of the protein-protein interactions has been limited and inconclusive. Therefore, the experiments conducted in this study focused on investigating the mechanism of interaction between WTI with the protein ligands Ciao 1, p53, par4, and U2AF65. To identify which WTI zinc finger(s) are critical in protein binding, a series of finger swap and deletion mutant proteins were created using site directed mutagenic PCR. The effects the mutant proteins had on the protein interactions were analyzed qualitatively using GST pulldown assays. Two different approaches were used for the GST pulldown assays. The first approach utilized bacterially expressed and purified proteins. None of the mutant WTI proteins exhibited a decrease in protein binding in these assays. Numerous pulldown trials involving various zinc fmger proteins revealed non-specific protein-protein interactions were occurring. The second approach employed in vitro translated 35S-labelled proteins. The results from these assays demonstrate a clear role for WT lzf3, and a possible role for WTI zf4 in the WT 1-par4 interaction. The replacement of WT 1 zinc fingers 3 and 4 with those from YY1 caused a distinct reduction in binding to par4 which was exclusive for the WT1-par4 interaction. YY1 is a transcription factor from yeast that contains four C2H2 type zinc fingers. A decrease in binding between the chimeric proteins WTI :YY1 and the protein partners Ciao 1 and U2AF65 was also observed, although to a much lesser extent. This difference in binding ability may indicate that the interactions between WT1 and its protein ligands involve different zinc fingers.

Zhang Xianliang's writing, best known for breaking sexual taboos, is also praised for its exposition of the Communist Party of China's persecution of male intellectuals, which led ultimately to their physical and psychological emasculation. Since the founding of the Qin dynasty in 221 BCE, Chinese intellectuals have been a primary target in the political campaigns of whatever elite happened to be in power, and Zhang's fictionalized autobiography apparently minors this narrative. However, it is the purpose of this thesis to offer a radically different reading, one that examines what is left unsaid in Zhang's texts. what falls under the mark of erasure- the status, role, and function of women in Chinese society . Drawing upon analytical techniques from Deconstruction, Feminist criticism and Freudian analysis I explore the following questions: (I) why are Chinese male intellectuals obsessed with having political power? (2) What is the relationship between politics and sexuality in the People's Republic? (3) What is it in the psychological make-up of male intellectuals which allows them to victimize women after they themselves were victimized? (4) How is it possible for the author to reconcile his criticism of state policies while supporting the rhetoric of the Party's propaganda? A close examination of the three texts under review yields a wealth of information, some of which answers questions, some of which raises other questions. However, in reading Zhang Xianliang's trilogy two things become apparent: his protagonist, Zhang Yonglin, only regains his "manhood" both psychologically and sexually through the intervention of women; and the unspoken truth that their insatiable desire for political and sexual power contributed to the "tragic" fate of male intellectuals in modern Chinese society.

Demonstrating a lacuna within the discipline of anthropology regarding its connection to colonialism in North America. this dissertation analyses Julian Steward's oeuvre and theorises him in four novel ways. First, his life-work is introduced with a focus on his representations of Indigenous Peoples. Second, his life-work is contextualised with respect to American federal Indian policy. Third, Steward's evolutionary theory is shown to have been designed as an explicit counter to Boas' method, belying a Spencerian biological analogy, and placing him outside of the "Americanist tradition." Finally, the culmination of Steward's method and theory, heralded as an objective approach to understanding Indigenous Peoples social organisation and the "scientific" method of anthropology, is exposed as a programmatic of the US Department of Justice in proceedings before the Indian Claims Commission, and showing it as a colonial science. Archival material regarding Steward's involvement in the Uintah Ute, Dockets 44 & 45 before the Indian Claims Commission, forms the data for this exposition. Exposing the connection of Steward's work to US government policy begins to fill the gap regarding anthropology's connection to colonialism in North America, and prompts a serious reconsideration of the discipline's method. practice, science, history, historiography, and curriculum regarding Indigenous Peoples.

Understanding how animals detect and discriminate different qualities of light is a key component of the study of visual ecology. My research investigated the use of three electrophysiological methods to assess the neuronal mechanisms involved in spectral and polarization sensitivity in one species of salmonid, the rainbow trout (Onchorynchus mykiss). 1 examined the neuronal mechanisms underlying polarization sensitivity using electroretinograms (ERG) and optic nerve compound action potential (CAP) recordings. Chromatic adaptation and pharmacological techniques were used to reveal opponent interaction at the cone-horizontal cell level and to provide the first evidence of retinal processing of polarization sensitivity. To facilitate additional research more suited to the exploration of neural networks and signaling, I developed the protocols and techniques necessary to investigate the spectral sensitivity of rainbow trout using whole-cell patch clamp (WPC) electrophysiology, and produced the first assessment of the ultraviolet component of spectral sensitivity in a vertebrate using this technique.

An experimental investigation on active aeroelastic aircraft structures with bending-torsion coupling properties is presented. Two techniques for vibration and flutter alleviation are studied and tested. The passive approach is based on the use of carbon composite spars with misaligned fibres. The second technique involves an active spar with a multi-cross section embedded with PZT actuators. A wing was designed and manufactured for testing in a wind tunnel and subsequently implemented on a demonstrator platform for flight testing. Results show that a carefully designed misalignment of the fibres can lead to significant performance increase. The active system based on PZT actuators with a linear controller exhibits significant improvements in aeroelastic performance compared to the passive system. The research findings lead to the conclusion that significant vibration reduction and flutter envelope extension can be achieved using the proposed strategies.

A collection of lyrical, free verse poems that trace the evolution of a young woman's consciousness as she matures into the roles of spouse. mother and grown daughter. The natural -slope"" from order to disorder runs through the poems as secrets take shape, children are injured, a marriage falters, and a mother dies. Even sleep, a recurring theme, loses its innocence: first appreciated for the rest it offers, it is soon disparaged as "grease for the gears of loss. rehearsal for complete darkness."

Pituitary adenylate cyclase-activating polypeptide (PACAP) is a ubiquitous peptide hormone involved in the regulation of several physiological processes. This hormone is a member of the glucagon superfamily of hormones, which are primarily involved in regulation of metabolism and growth. PACAP shows the highest sequence conservation of this superfamily during evolution, suggesting a critical role for PACAP in species survival. Mice lacking PACAP (Adcyap 1) show high mortality during the postnatal period, as well as impaired reproduction in females. In this thesis I have characterized the reproductive phenotype in female mice lacking PACAP due to disruption (knockout) of the single copy pacap gene (Adcyapl ). Previous experiments in other laboratories have described reduced fertility in mice lacking PACAP or one of its receptors, the PAC] receptor. However, the mechanism by which PACAP acts to enhance reproduction has not yet been elucidated. The purpose of this study was to determine the site(s) of action of PACAP in the cascade of reproductive events from puberty to implantation. I hypothesized that PACAP was an important regulator of an early phase of reproduction, and that lack of PACAP would result in impaired reproductive success. Initially I examined puberty onset, estrous cycles, mating behaviour, and delivery of live offspring. Estrous cycles were evaluated through vaginal cytology, both in juvenile mice, to confirm that puberty had occurred, and in adult females, to determine if they maintained a normal 4-5 day estrous cycle. Mating behaviour was evaluated through a natural mating strategy, with daily assessment of the presence of a copulatory plug. The reproductive outcome of delivering live pups was characterized, and pup survival was followed. I then characterized PACAP null mice as to ovulation, ovarian histology and fertilization of eggs in vivo. Finally, I measured implantation rates in PACAP null females, as well as levels of the hormone prolactin, an essential regulator of early pregnancy. In the present study I found a number of reproductive functions that were normal without PACAP. Puberty onset was unaffected in knockout mice and they displayed regular 4-5 day estrous cycles. Also. PACAP null females mated when paired with a male of proven fertility. However, mating behaviour follows an unusual pattern in PACAP null mice, where 33% mate on more than one day during a week-long pairing unlike wild-type mice that would normally mate only once. Also, significantly fewer PACAP null females than wild-type females gave birth following mating: 21% and 100%, respectively. Ovulation and ovarian histology were normal in PACAP null females, as was fertilization of released eggs. However, only 13% of PACAP null females had implanted embryos 6.5 days after mating. The mechanism of impaired implantation may be a defect in prolactin secretion. Prolactin levels were significantly lower in PACAP null females than in wild-types following mating. Prolactin is an essential hormone for the support of early pregnancy. These results support the conclusion that PACAP acts as an important regulator of prolactin in reproduction. It is possible that PACAP in the hypothalamus is the dominant prolactin-releasing factor, which has been sought many years but never definitively identified.