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To estimate the contribution of outdoor recreation on rural property sales in Mississippi, information was collected from lenders and appraisers associated with the Federal Land Bank, Mossy Oak Properties, and Rutledge Investment Company on properties sold from 2003-2008 in three regions of Mississippi: Mississippi Delta/Hills Region, North Mississippi Region and South Mississippi Region. Property sales information was collected on 102,747 hectares (ha) of rural properties valued at $475.1 million. Hedonic regression analysis was used to quantify the contribution of outdoor recreation on Total Sale Value (TSV). Outdoor recreation contributed $160.6 million of the TSV. Forests comprised 71% of land coverage statewide. Attributes that were related to TSV statewide were row crop lands, bottomland hardwood forests, mixed pine-hardwood forests, planted pine forests, pasture/fallow fields, natural pine forests, upland hardwood forests, cutover woodland forests, and overnight sleeping quarters. Attributes related to TSV varied across the three regions. Statewide, hunting was expected to be conducted on at least 96% of the properties sold. In the Mississippi Delta/Hills Region, outdoor recreation contributed the greatest percent increase in land value (55.4%) and properties leased for a greater value ($58.70 per ha). Information provided by this study will encourage rural property owners to justify enhancements of wildlife habitats, provide recreational opportunities, and enhance their income. Rural land appraisers will use the information to appraise lands more accurately, and resource and regulatory agencies will use it to protect wetlands and other sensitive lands or mitigate for adverse impacts.

Advances in synthesis of boron-containing molecules significantly enlarged the usage of boron-containing subunits in medicinal chemistry. Interestingly, few recently approved drugs are boron analogues of natural amino acid derivatives. They contain an aminoboronic subunit. This subunit is also known to serve as a useful synthetic intermediate. However, despite its unique properties, limited examples of its synthesis are reported. In this work, a new method of obtaining aminoboronic acids derivatives is discussed. In Chapter 2 conditions towards obtaining β-aminoboronic acid derivatives via anti-Markovnikov Cope-type hydroamination are presented. Cope-type hydroamination with boron containing species have shown to proceed at lower temperatures compared to unsubstituted alkene derivatives. The products of Cope-type hydroamination reaction are new: to our knowledge similar oxazaborolidine heterocycles have not been reported. Despite reduced stability of the synthesised products and their proneness to conduct bora-Cope type elimination reaction, it was possible to demonstrate oxazaborolidine synthetic utility by various derivatization reactions. A scope with primary and secondary hydroxylamines is presented for a vinylboronate substrate. This work required access to a range of hydroxylamines. Recently our group discovered simple conditions to oxidize amines to hydroxylamines. In Chapter 3 an investigation of isolation conditions for a variant of this newly developed hydroxylamine synthesis is presented. While the oxidation is generally efficient in the presence of excess amine, the main challenge proved to be the propensity of the unreacted amine and hydroxylamine product to interact together. The efficiency and main limitations of different isolation strategies are presented. In general, the best results of removal of the excess amine via filtration were obtained using oxalic acid to form the corresponding amine salt. This filtration was followed by a short silica plug to further remove the amine salt causing contamination.

Reniform nematode, Rotylenchulus reniformis is a semi-endoparasitic nematode infecting over 300 plant species including important fiber crops like cotton. Introgression of reniform nematode resistance from a distantly-related resistant species Gossypium longicalyx into cultivated upland species Gossypium hirsutum has been a challenge. An approach towards achieving nematode resistance in crop plants has been to identify candidate parasitism genes expressed in the nematode facilitating infection of host plant species, and silencing the same through reverse genetic approaches like RNAi. A cDNA library constructed from the sedentary female stage of reniform nematode revealed an EST coding for C-type lectins and occurring in high frequency. Identification and characterization of C-type lectins in reniform nematode is important in understanding the immune system of nematode and in planning strategies for the development of reniform nematode resistant cotton varieties. A total of 11 C-type lectin gene family members were identified across six life stages of reniform nematode, with each member expected to play a significant role in the development and parasitic establishment with the host plant. Conserved sites characteristic of C-type lectins found in other organisms have been identified in the C-type lectin genes in reniform nematode for binding of Ca+2 and mannose. The highest level of expression of C-type lectins was observed in the sedentary female stage indicating it to be possibly the most sensitive stage to microbial infection and so a likely stage to target for its management. The site of secretion of C-type lectins in the sedentary female stage could be identified by in situ hybridization as the hypodermal region of the exposed posterior body region which is not inserted into the host root tissue. Phylogenetic analyses of C-type lectin domains of various nematode groups placed the plant-parasitic nematodes in one group indicating the possibility of co-evolution and probably carrying out a similar function aiding in the establishment of parasitism with host plants. Our findings now extend the spectrum of known nematode C-type lectin genes and suggest that lectin activity might be a more general feature of parasitism which could be explored in better understanding the interactions occurring at the host-nematode and nematode-pathogen interfaces.

Type IV pili (T4P) are hair-like adhesins involved in many processes, including surface attachment, twitching, DNA uptake, electron transfer, and pathogenesis. These flexible filaments are expressed in various pathogens, including the opportunistic pathogen Pseudomonas aeruginosa. The pilus fibre is primarily composed of the major pilin structural subunit, PilA, which is rapidly polymerized or depolymerized during pilus extension or retraction, respectively. The transcription of pilA is tightly controlled by the PilS-PilR two-component system, which responds to fluctuating levels of PilA in the inner membrane. In addition to pilA, the response regulator, PilR, also regulates a subset of other non-T4P related genes. Here, we used hyperactivating point mutants in the PilS-PilR two-component system, which induce hyperpiliation without loss of pilus function, to assess the effects of increased surface pili expression on virulence against Caenorhabditis elegans, and to identify additional non-T4P genes regulated by the PilS-PilR two-component system. We hypothesized that dysregulation of the PilS-PilR two-component system impacts the expression of pilA and other genes, which impacts both surface piliation and T4P dynamics, resulting in altered P. aeruginosa virulence. C. elegans slow killing assays revealed that hyperpiliation, independently of T4P function, reduces virulence of model P. aeruginosa strains PAK and PA14. We propose a model whereby a surfeit of pili reduces virulence, potentially through impeding effective engagement of contact-dependent antagonism systems, such as the type III secretion system. Transcriptomic analysis of the hyperactive PilR point mutant also identified a subset of 26 genes, including those related to phenazine biosynthesis, quorum sensing, and ethanol oxidation, regulated by the PilS-PilR two-component system. Last, a T4P cysteine-labelling system was implemented for P. aeruginosa, allowing for the visualization of real-time pilus dynamics. Together, this work provides new insights into the consequences of hyperpiliation and the scope of the PilS-PilR signalling network, as well as novel tools for investigating P. aeruginosa T4P dynamics in vivo. / Thesis / Master of Science (MSc) / Pseudomonas aeruginosa is a major contributor to hospital-acquired infections and is of particular concern due to its intrinsic resistance to many frontline antibiotics. To aid in infection, Pseudomonas encodes an arsenal of virulence factors, including type IV pili (T4P), hair-like adhesins involved in many processes, such as twitching motility and surface attachment. T4P are primarily composed of the major pilin, PilA, whose expression is tightly regulated by the PilS-PilR two-component system. The sensor kinase, PilS, monitors the inner membrane PilA inventory and modifies activity of the response regulator, PilR, to regulate pilA transcription. Here, we demonstrate that P. aeruginosa virulence in a roundworm infection model is reduced when the amount of T4P expressed at the cell surface increases, regardless of the ability of the bacteria to twitch. We propose that inappropriate increases in surface T4P expression may impair pathogenicity-associated systems which require intimate host-cell contact. New genes in the regulon of the PilS-PilR two-component system were also identified. A tool to fluorescently label and image T4P in real-time using microscopy was established in the lab. This work highlights the consequences of increased surface T4P expression, providing potential new targets for antipseudomonal therapeutics which act on components involved in T4P expression and function.

Cardiovascular diseases are the leading cause of mortality worldwide. Ataxia telangiectasia mutated kinase (ATM) is a checkpoint protein involved in cell cycle regulation. It is activated in response to genotoxic mediators such as double-stranded DNA damage or oxidative damage. Mutations in the ATM gene result in a multisystemic disease called ataxia-telangiectasia (A-T). Independently, a Western-type Diet (WD) and ATM protein deficiency are linked with heart disease, exacerbated cardiac remodeling, and myocardial infarction (MI). Our laboratory has previously shown that in male mice, the consumption of a WD during ATM deficiency is associated with the exacerbation of cardiac remodeling. This study investigated the effect of ATM deficiency on WD-induced cardiac remodeling parameters before and 1-day post-MI in a sex-specific manner using female and male mice. Age-matched wild-type (WT) and ATM heterozygous knockout (hKO) mice were fed with normal-chow (NC) or WD for 14 weeks. MI was induced by ligation of the left anterior descending coronary artery (LAD) with a 7-0 polypropylene suture. After the study period, 14 weeks post-WD feeding and 1-day post-MI, the heart was removed through an opening in the diaphragm region. Heart sections were stained with Masson's trichrome to quantify fibrosis, TUNEL-stained to quantify apoptosis, infarct size, and infarct thickness, and wheat germ agglutinin-stained to quantify myocyte hypertrophy. In WT female mice, WD increased myocardial fibrosis, myocyte hypertrophy, and apoptosis at baseline compared to NC. However, in hKO-WD female mice, apoptosis was significantly lower, and hypertrophy was significantly higher than in WT-NC female mice at baseline. Intriguingly, no significant difference in apoptosis, infarct size, and infarct thickness was observed in both genotypes and genders 1-day post-MI. Thus, our data suggest that 1) ATM deficiency plays a cardioprotective role in female mice responding to WD, as it reduces apoptosis and increases hypertrophy at baseline, and 2) sex-specific cardioprotective effects of ATM deficiency in female mice were not observed 1-day post-MI in response to WD.

Type IV pili (T4P) are long, fibrous surface appendages involved in attachment, motility, biofilm formation and DNA uptake that are expressed by bacteria and archaea. They are an important virulence factor for a number of bacteria, including Pseudomonas aeruginosa, an opportunistic pathogen that is a common cause of nosocomial infections. T4P are composed mainly of monomers of the major pilin subunit, PilA, although several low abundance proteins called minor pilins are also present. These surface-exposed proteins are potential vaccine candidates, although a more complete understanding of their diversity and function is required for the rational development of a pilus-based vaccine. There are five distinct groups of P. aeruginosa major pilins, which vary based on their sequence and their associated accessory proteins, and two distinct sets of minor pilins, although the roles of the latter in pilus biology are poorly understood. This study focuses on the structural characterization of major and minor pilins and functional implications for pilus assembly and disassembly dynamics. The structural analysis of major pilins from groups III and V revealed specific differences in pilin structure that may affect subunit interactions within the pilus fibre and interactions with their specific accessory proteins and minor pilins. The minor pilins PilVWX were shown to form a putative subcomplex with the adhesin and anti-retraction protein PilY1, which is proposed to prime pilus assembly and thus traffic PilY1 to the bacterial surface. High resolution X-ray crystal structures of the minor pilins FimU and PilE were solved and functional characterization suggested that FimU and PilE are necessary for efficient pilus assembly to stably connect the priming subcomplex to the major pilin subunits. Together, this work has increased our understanding of pilin diversity and defined a concrete role for the minor pilins in pilus assembly. / Thesis / Doctor of Philosophy (PhD) / Pseudomonas aeruginosa is a bacterium that can take advantage of a weakened immune system to cause lethal infections. The first step of infection involves attachment to the host using long sticky fibres called type IV pili. Each fibre is composed primarily of a single protein, the major pilin, but also contains low abundance proteins called minor pilins. Without these proteins, the bacteria can’t attach and cause infections, making pilins excellent vaccine candidates. This study focused on the characterization of major and minor pilins to understand the diversity of these proteins and how these differences might affect pilus assembly. We show that the molecular structure of the major pilin differs between strains although the core architecture is the same, and that the minor pilins are required for initiation of pilus assembly. This work furthers our understanding of the structures and functions of pilin proteins, and provides information helpful for the development of vaccines.

No description available.

ABSTRACT: Objectives: Masseter muscle fast-fiber composition is reportedly increased on the deviant facial asymmetry side in dentofacial deformities patients. Recently, four distinct asymmetry classes have been identified, based on posterior-anterior cephalometrics in this same population, which may have different functional etiologies. Our aim is to relate muscle fiber type properties with specific asymmetric craniofacial growth in these asymmetry groups. Methods: Diagnostic evaluations, radiographs, and masseter specimens were obtained from orthognathic surgery patients at the University of Lille. Immunohistochemical muscle staining and morphometrics determined the mean areas and percent occupancies of slow-I, fast-II, neonatal, atrial and hybrid fiber types. Eighty-three subjects (twenty nine symmetric, fifty-four asymmetric) had at least unilateral (left or right) fiber type information, while twenty-seven had bilateral (left and right) data. Fiber data were compared between symmetry and asymmetry subjects and between the four asymmetry classes. Significant differences between groups were determined by Fisher’s and ANOVA tests. Results: Type-II mean fiber area (p<0.006) and percent occupancy (p<0.018) were significantly greater on shorter ramal sides in asymmetric compared to symmetric subjects, supporting previous data for facial vertical dimension asymmetry. Neonatal- atrial mean fiber area (p<0.017) and percent occupancy (p<0.027) were decreased in 3 asymmetric groups. No significant difference was found amongst the four asymmetry classes (p<0.05). Conclusions: Imbalanced skeletal proportions are associated with similar imbalances in fiber type properties in left versus right masseter muscle biopsies sampled in the same patient at the time of orthognathic surgery. Specific to our findings, there is an association between increase in neo-atrial and decrease in type II fiber type area and percent occupancy in symmetric patients. / Oral Biology

Chlamydia is the most prevalent sexually transmitted bacterial infection in many developed countries, including Canada. Untreated infections in women can lead to a number of complications including pelvic inflammatory disease, tubal factor infertility, and ectopic pregnancy. Public health programs, including screening for at-risk individuals, partner identification, and antibiotic treatment, have had limited success in controlling the rising incidence of chlamydial infections over the past two decades. A chlamydia vaccine that prevents infection and its pathological sequelae is the next essential step to control this persistent public health problem. Chlamydia spp. utilize the highly conserved type III secretion (T3S) system as an essential virulence factor for infection and intracellular replication. Here, we evaluated a novel chimeric antigen (BD584) consisting of three T3S proteins from C. trachomatis (CopB, CopD, and CT584) as a potential chlamydia vaccine candidate. Intranasal immunization with BD584 elicited strong humoral responses that neutralized infection in vitro. Following intravaginal challenge with C. muridarum, immunized mice had a 95% reduction in chlamydial shedding and a 87.5% reduction in incidence of upper genital tract pathology compared to control mice. BD584 immunization generated strong cell-mediated and mucosal antibody responses in mice with different genetic backgrounds, and conferred protection against an intravaginal C. trachomatis infection in two out of three strains of mice. BD584 formulated with NE01, a mucosal adjuvant known to be safe and effective in humans, was shown to be highly immunogenic and efficacious against C. trachomatis infection in mice. These results suggest that BD584 may represent a promising antigen for use in a chlamydia vaccine. / Thesis / Doctor of Philosophy (PhD) / Chlamydia is the most common sexually transmitted bacterial infection in the world. The goal of this thesis is to evaluate a novel chlamydia vaccine in a mouse model of genital chlamydia infection. We engineered a fusion protein, BD584, made up of three highly conserved type III secretion (T3S) proteins CopB, CopD, and CT584. We show that vaccination with BD584 generated strong immune responses and protected mice from chlamydia infection and the associated reproductive tract disease. Interestingly, the level of protection afforded by BD584 vaccination is dependent upon the genetic background of the animal. Furthermore, we have identified particular antibody subtypes directed against BD584 as markers of BD584-mediated protective immunity. Lastly, we show that vaccination with BD584 formulated with a clinically safe and effective mucosal adjuvant generates robust immune responses and confers protection against chlamydia in mice. Together, these results provide support for the use of T3S proteins in a chlamydia vaccine.