Alfalfa is an important forage crop in North America which can also escape cultivation and establish in unmanaged habitats. Genetically modified (GM) alfalfa has been approved for environmental release in Canada and the United States and the occurrence of alfalfa in unmanaged natural and semi-natural habitats may compromise the successful co-existence of GM and non-GM alfalfa. To-date, little information has been available on the nature and dynamics of roadside alfalfa populations and their ability to become feral. Such knowledge is necessary to design efficient trait confinement protocols and to enhance the co-existence of GM and non-GM alfalfa within agricultural regions. The overall aim of this work was to characterize roadside alfalfa populations and to establish their role in novel trait movement. A roadside survey revealed the widespread occurrence of feral alfalfa populations in southern Manitoba. We described the seedbanks of roadside alfalfa populations, seedling recruitment and adult reproductive success, indicating that alfalfa is capable of establishing self-perpetuating feral populations in unmanaged habitats. We also noted the successful establishment of alfalfa in a grass sward representing roadside vegetation. Roadside mowing can reduce (and perhaps prevent) seed production in roadside alfalfa; however, mowing failed to drive the populations to extinction in the short-term. Herbicide (2,4-D) applications controlled alfalfa plants but seeds in the seedbank may still contribute to new seedling recruitment. The roadside alfalfa populations we worked with exhibited high levels of genetic diversity, indicating an absence of past population bottlenecks or genetic drift. In addition, phenotypic characterization provided evidence that roadside alfalfa populations were experiencing selection pressure for adaptive traits including winter survivability, rhizome production and prostrate growth habit; all traits that favor persistence in unmanaged habitats. We also noted the occurrence of high (>60%) levels of outcrossing in feral alfalfa populations, establishing their role as sources and sinks for novel traits. Our findings indicate that alfalfa populations occurring in unmanaged habitats need to be considered in trait confinement protocols in order to reduce the adventitious presence (AP) of novel traits and to enhance the successful co-existence of GM and non-GM alfalfa.

Converging evidence indicates that SOD1 aggregation is a common feature of mutant SOD1 (mSOD1)-linked FALS, and seems to be directly related to the gain-of-function toxic property. However, the mechanisms of protein aggregation are not fully understood. To study the contribution of modification on cysteine residues in SOD1 aggregation, we systematically examined the redox state of SOD1 cysteine residues in the G37R transgenic mouse at different stages of ALS and under oxidative stress induced by H2O2. Our data showed that under normal circumstances, cysteine 111 in SOD1 is free. Under oxidative stress, it is prone to oxidative modification by providing the thiolate anion (S-). With the progression of ALS, increased levels of oxidative insults facilitated the oxidation of thiol groups of cysteine residues. Human mutant SOD1 could generate an upper shifted band in SDS-PAGE, which turned out to be a Cys111-peroxidized SOD1 species. We also found that at different stages of ALS, accumulated oxidative stress facilitated the aggregates formation, which were not mediated by disulfide bond. The oxidative modification of cysteine 111 may promote the formation of disulfide bond-independent SOD1 aggregates. In addition, we investigated the correlation between nitrosative stress and S-nitrosylation of protein disulfide isomerase (PDI) in the mechanism of aggregates formation. Our data showed that up-regulated inducible nitric oxide synthase (iNOS) generated high levels of nitric oxide (NO), which induced S-nitrosylation of PDI with the progression of ALS in the spinal cords of mSOD1 transgenic mice. This correlation was confirmed by treating SH-SY5Y cells with NO donor SNOC to trigger the formation of S-nitrosylated PDI (SNO-PDI). When mSOD1 was overexpressed in SH-SY5Y cells, iNOS expression was up-regulated, NO generation was increased consequently. Furthermore, both SNO-PDI and mSOD1 aggregates were detected in these cells. Blocking NO generation with NOS inhibitor N-nitro-L-arginine (NNA) attenuated the S-nitrosylation of PDI; the formation of mSOD1 aggregates was inhibited as well. We conclude that NO-mediated S-nitrosylation of PDI is highly linked to the accumulation of mSOD1 aggregates in ALS.

This master's thesis deals with the reification, or transformation into objects, of the female characters in Michel Butor's La Modification. It is our contention that the two female characters, Henriette and Cecile, function not as characters, but as objects: they are unable to take up subject positions, and they have the same roles as the other inanimate objects in Butor's work. The critical analysis is based in part on existentialist, psychoanalytic, and poststructuralist theories of subjectivity, as well as feminist rereadings of these theories. We have also used several critical and theoretical works on the object in the "Nouveau Roman", in the novels of Michel Butor, and, specifically, in La Modification. / The first chapter deals with the work of several feminist theoreticians, who claim that woman is objectified in patriarchal society because she has no access to subjectivity, be it through the means of action, of vision, or of language. In the second chapter we discuss critical writings on the treatment and role of the object in Butor's work, writings which claim that these objects have a specific role to contribute to the characterisation of the main character, and to allow this main character to take up a position as subject. In the third chapter we examine the link between these two critical fields. The female characters in La Modification are objectified because they are not able to assume subject positions, they have no access to subjectivity through action, vision, or language. In addition, the female characters have the same narrative role as the other objects in the novel.

No description available.

A variety of synthetic bone graft materials such as the polymer poly(lactic-co-glycolic acid) (PLGA) have been investigated as alternatives to current tissue based bone graft materials. In this study, efforts have been made to improve the tissue-PLGA interface by immobilizing bone morphogenetic protein-2 (BMP-2) in an oriented manner on scaffolds using covalently immobilized heparin. The results demonstrated a four-fold increase in covalently immobilized heparin compared to non-specific heparin attachment. Furthermore, the scaffolds with covalently attached heparin retained approximately three-fold more BMP-2 than did either scaffolds with no heparin attached or scaffolds with non-specific heparin attachment. The activity of scaffolds with BMP-2 immobilized in various manners was examined using an alkaline phosphatase assay on C3H10T1/2-seeded scaffolds. These results indicated approximately twice the amount of activity with scaffolds that had BMP-2 immobilized with covalently attached heparin than on scaffolds with adsorption of BMP-2 and a three-fold increase in activity when compared to scaffolds that had non-specific heparin attachment as the mechanism for BMP-2 immobilization. These results demonstrated that PLGA with covalently linked heparin has potential to immobilize BMP-2 in a specific orientation that is favorable for cell-receptor binding, leading to the more efficient use of the bone-growth factor.

Surface-induced osseointegration and antibacterial capability are very important criteria for the clinical success of titanium implants. To enhance these two criteria, an architectural hybrid system is constructed onto Ti-6Al-4V with a rough surface. First, thermal oxidation (TO), treatment with hydrogen peroxide (H2O2) and a mix of TO and H2O2 (Mixed) are used to modify the surface topography and chemistry of Ti-6Al-4V disks. Surface characterizations by the use of microscopes and spectroscopes indicate that TO can induce more favorable topography, roughness, wettability and hydroxyl group concentration on Ti-6Al-4V surfaces. Therefore, an alginate/chitosan LBL film that incorporates antibacterial nano-silver is bridged onto thermally oxidized Ti-6Al-4V alloy by mussel-inspired dopamine. The microscopies and spectrometers confirm that the hybrid system is successfully fabricated onto the Ti-6Al-4V surface while the sub-micron topography induced by TO is maintained. Bone marrow stem cell (BMSC) adhesion, proliferation and differentiation are up-regulated by the synergy of sub-micron surface produced by TO and alginate/chitosan LBL film. The incorporation of nano-silver into the hybrid system is demonstrated to inhibit the growth of Escherichia coli and Staphylococcus aureus, but not jeopardize the enhanced BMSC activities. Taken together, this thesis presents a promising strategy to fabricate novel Ti-6Al-4V implants with enhanced osseointegration and antibacterial capability.

This study investigated the relationship between smoking cessation and cognitive factors of attributional style, self-efficacy and locus of control. The roles of examined as they contributed to the prediction of smoking status. Questionnaires designed to measure these cognitivevariables, were administered to participants of smoking cessation programs at two times during the study; immediately before participation in the smoking cessation program and immediately after completion of the program. Smoking status was assessed at these times, as well as via telephone twice after the program's completion. Subjects were obtained from 16 American Cancer Society smoking cessation clinics in the Southern California area. The results of stepwise discriminant analyses of variance successfully predicted smoking status at end-of-clinic and follow-up periods, using a combination of demographic, smoking behavior and cognitive predictors. Cross-validations of the predictive models also were able to predict smoking status at end-of-clinic and follow-up. Additional analyses included stepwise discriminant demographic and smoking behavior variables styles, as well as demographic and smoking behavior Cognitive Factors 5 analyses of participants who relapsed at follow-up, and a comparison of those who completed the program versus those who dropped out prematurely. Both analyses resulted in obtaining significant discriminant functions. A final analysis compared pre- and post-treatment responses on the cognitive measures via a 2 X 2 multiple analysis of variance (group X time). A significant interaction between group and time of assessment was obtained. / Department of Counseling Psychology and Guidance Services

This study investigated the effects of self-instruction and alternate response training on oppositional behavior. Four oppositional adolescent females in a community-based residential treatment facility were taught to self-instruct alternate responses to their oppositional behaviors by participating in a series of Behavior Skills Training (BST) sessions. Subjects were required to role-play situations which subjects indicated evoke the targeted behaviors, that is, swearing/namecalling, noncompliance with rules, and noncompliance with requests. These self-reported situations were a major component in developing the BST. A multiple baseline design across behaviors was used. As an additional experimental control, two nontreatment subjects were included in the data analysis. Although trend analyses were conducted, variability in the data precluded the possibility of drawing conclusions based on statistical correlation. However, functional analyses of the treatment effects indicated that the BST was effective in reducing the oppositional behaviors of the subjects in the treatment group. Thus these results support the efficacy of using self-instruction and alternate response training procedures to reduce the occurrence of oppositional behavior in adolescent females. / Department of Educational Psychology

There is an ever-increasing desire to develop novel materials that could control the release of active compounds and increase their stability. Replacing petroleum-based synthetic polymers with sustainable materials has many advantages, such as reducing the dependence on fossil fuels, and diminishing environmental pollution. Recently, cellulose nanocrystal (CNC) obtained by acid hydrolysis of cellulose fibres has gained a lot of interest. The high mechanical strength, large and negatively charged surface area, and the presence of several hydroxyl groups that allow for modification with different functionalities make CNC an excellent candidate for various applications in the biomedical field. This thesis explores (i) the surface modification and characterization of modified CNC and (ii) the biomedical applications of these novel sustainable nanomaterials. In the first part, amine functionalized CNC was prepared. Ammonium hydroxide was reacted with epichlorohydrin (EPH) to produce 2-hydroxy-3-chloro propylamine (HCPA), which was then grafted to CNC using an etherification reaction. A series of reactions were carried out to determine the optimal conditions. The final product (CNC-NH2(T)) was dialyzed for one week. Further purification via centrifugation yielded the sediment (CNC-NH2(P)) and supernatant (POLY-NH2). The presence of amine groups was confirmed by FT-IR and the amine content was determined by potentiometric titration and elemental analysis. A high amine content of 2.2 and 0.6 mmol amine/g was achieved for CNC-NH2(T) and CNC-NH2(P), respectively. Zeta potential measurements confirmed the charge reversal of amine CNC from negative to positive when the pH was decreased from 10 to 3. TEM images showed similar structural properties of the nanocrystals along with some minor aggregation. This simple, yet effective synthesis method can be used for further conjugation as required for various biomedical applications. Moreover, the surface of CNC was modified with chitosan oligosaccharide (CSos). First, the primary alcohol groups of CNC were selectively oxidized to carboxyl groups using the catalyst, 2,2,6,6- tetramethylpiperidine-1-oxyl radical (TEMPO), and were then reacted with the amino groups of CSos via the carbodiimide reaction using N-hydroxysuccinimide (NHS) and 1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). The appearance of C=O peak in FT-IR spectrum of oxidized CNC (CNC-OX), accompanied by calculations based on potentiometric titration revealed that CNC was successfully oxidized with a degree of oxidation of 0.28. The grafting of CSos on oxidized CNC was confirmed by the following observations: (i) the reduction of the C=O peak in FT-IR of CNC-CSos and the appearance of new amide peaks; (ii) the significant reduction of the carbonyl peak at 175 ppm in the 13C NMR spectrum for CNC-CSos; (iii) a higher decomposition temperature in TGA of CNC-CSos; (iv) a positive zeta potential of CNC-CSos at acidic pH; and (v) a degree of substitution of 0.26, which is close to the DO (0.28), indicating that 90% of COOH groups on CNC-OX were involved in the formation of amide bonds with CSos. TEM and AFM studies also revealed a completely diff erent morphology for CNC-CSos. In the second part, the potential of exploiting CNCs as delivery carriers for two cationic model drugs, procaine hydrochloride (PrHy) and imipramine hydrochloride (IMI), were investigated. IMI displayed a higher binding to CNC derivatives compared to PrHy. Isothermal titration calorimetry (ITC), transmittance and zeta potential measurements were used to elucidate the complexation between model drugs and CNC samples. It was observed that the more dominant exothermic peak observed in the ITC isotherms leading to the formation of larger particle-drug complexes could explain the increased binding of IMI to CNC samples. Drug selective membranes were prepared for each model drug that displayed adequate stability and rapid responses. Different in vitro release profiles at varying pH conditions were observed due to the pH responsive properties of the systems. Both drugs were released rapidly from CNC samples due to the ion-exchange e ffect, and CNC-CSos displayed a more sustained release profile. Furthermore, the antioxidant properties of CNC samples and the potential of CNC-CSos as a carrier for the delivery of vitamin C was investigated. CNC-CSos/vitamin C complexes (CNCS/VC) were formed between CNC-CSos and vitamin C via ionic complexation using sodium tripolyphosphate (TPP). The complexation was confirmed via DSC and UV-Vis absorbance measurements. TEM images showed complexes with a size of approximately 1 micron. The encapsulation efficiency of vitamin C was higher (91%) at pH 5 compared to pH 3 (72%). The in vitro release of vitamin C from CNCS/VC complexes exhibited a sustained release of up to 3 weeks, with the released vitamin C displaying higher stability compared to a control vitamin C solution. Antioxidant activity and kinetics of various CNC samples were studied using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay. CNC-CSos possessed a higher scavenging activity and faster antioxidant activity compared to its precursors, CNC-OX and CSos, and their physical mixture. Therefore, by loading vitamin C into CNC-CSos particles, a dynamic antioxidant system was produced. Vitamin C can be released over a prolonged time period displaying enhanced and sustained antioxidant properties since the carrier CNC-CSos also possesses antioxidant properties. As a result of this doctoral study, knowledge on the surface modification of CNC with amine groups and CSos have been advanced. The in vitro drug release and antioxidant studies suggest that systems comprising of CNC could be further explored as potential carriers in biomedical applications.

Alfalfa is an important forage crop in North America which can also escape cultivation and establish in unmanaged habitats. Genetically modified (GM) alfalfa has been approved for environmental release in Canada and the United States and the occurrence of alfalfa in unmanaged natural and semi-natural habitats may compromise the successful co-existence of GM and non-GM alfalfa. To-date, little information has been available on the nature and dynamics of roadside alfalfa populations and their ability to become feral. Such knowledge is necessary to design efficient trait confinement protocols and to enhance the co-existence of GM and non-GM alfalfa within agricultural regions. The overall aim of this work was to characterize roadside alfalfa populations and to establish their role in novel trait movement. A roadside survey revealed the widespread occurrence of feral alfalfa populations in southern Manitoba. We described the seedbanks of roadside alfalfa populations, seedling recruitment and adult reproductive success, indicating that alfalfa is capable of establishing self-perpetuating feral populations in unmanaged habitats. We also noted the successful establishment of alfalfa in a grass sward representing roadside vegetation. Roadside mowing can reduce (and perhaps prevent) seed production in roadside alfalfa; however, mowing failed to drive the populations to extinction in the short-term. Herbicide (2,4-D) applications controlled alfalfa plants but seeds in the seedbank may still contribute to new seedling recruitment. The roadside alfalfa populations we worked with exhibited high levels of genetic diversity, indicating an absence of past population bottlenecks or genetic drift. In addition, phenotypic characterization provided evidence that roadside alfalfa populations were experiencing selection pressure for adaptive traits including winter survivability, rhizome production and prostrate growth habit; all traits that favor persistence in unmanaged habitats. We also noted the occurrence of high (>60%) levels of outcrossing in feral alfalfa populations, establishing their role as sources and sinks for novel traits. Our findings indicate that alfalfa populations occurring in unmanaged habitats need to be considered in trait confinement protocols in order to reduce the adventitious presence (AP) of novel traits and to enhance the successful co-existence of GM and non-GM alfalfa.