Ultra-thin films of pure elements are important in microelectronics due to their wide range of applications. Atomic Layer Deposition (ALD) has drawn increasing attention as the thin films deposition technique for applications in microelectronics, due to its ability to deposit thin films with high conformality with atomic level control of the thickness of the film. However, due to the limited number of suitable precursor/co-reactant pairs available, only a few pure elements have been deposited successfully by ALD to date. The current study involves the synthesis and identification of potentially suitable precursor and co-reactant molecules for ALD of elemental Zn and Ge, neither of which have previously been achieved. MeZnOiPr, Zn(OiPr)2, and ZnEt2 were investigated as Zn precursors while GeCl2(Dioxane), Ge{N(SiMe3)2}2, and Ge(OCH2CH2NMe2)2 were investigated as Ge precursors. Co-reactants of interest were, 4,4,5,5-tetramethyl-1,3,2-dioxaborolane (HBpin), PhSiH3, [H2Al(tBuNCH2CH2NMe2)] (LAlH2), BH3(NMe3), and AlH3(Quinuclidine). Ligand-exchange reactions between precursors and co-reactants were expected to produce unstable zinc or germanium hydride species, which would then reductively eliminate to produce the pure element. Solution reactivity studies were employed to identify potential precursor/co-reactant pairs. Solution reactions of Zn precursors with the selected co-reactants indicated that unstable ZnH2 is produced during the reactions, and will dissociate into its elements (Zn and H2) at room temperature. These solution reactivity studies revealed that, HBpin and LAlH2 were more reactive as co-reactants than BH3(NMe3), AlH3(Quinuclidine), and PhSiH3. Additionally, MeZnOiPr and ZnEt2 exhibited the highest reactivity as precursors, although the lower reactivity of Zn(OiPr)2 may simply be due to low solubility. Solution reactions of Ge precursors produced a polymeric mono-germanium hydride species (GeH)x, which will only dissociate into its elements upon heating at elevated temperatures. While LAlH2 indicated high reactivity with all Ge precursors, it was difficult to arrange co-reactants in order of reactivity as most reactions immediately produced insoluble (GeH)x upon mixing reagents at room temperature. Ge(OCH2CH2NMe2)2 found to be the most reactive precursor out of all Ge precursors investigated. / Thesis / Master of Science (MSc)

Introduction: Irritable bowel syndrome (IBS) is characterized by gastrointestinal (GI) symptoms, and as a consequence of dysregulated communication via the gut-brain axis, is highly comorbid with mental illnesses such as anxiety and depression. With no known cure, IBS patients must manage their symptoms through lifestyle factors. Physical activity is one such lifestyle factor that reduces GI symptoms and improves mental health; however, it remains unclear whether physical activity buffers against the acute worsening of IBS symptoms following a stressor. Method: To investigate this, we evaluated the stress reactivity and recovery of 9 IBS patients and 13 healthy controls following exposure to acute stress. We exposed participants to an electronic Trier Social Stress Test (e-TSST) and measured changes in psychological stress (state anxiety), physiological stress (sympathovagal balance, where higher LF/HF ratio indicates greater stress system activation), and GI symptom severity before, during and every 20 minutes for one hour after. Physical activity was measured using the Stanford Seven-Day Physical Activity Recall questionnaire and quantified as weekly energy expenditure. Results: IBS patients had higher state anxiety (p = .05), LF/HF ratio (p = .01) and GI symptom severity (p = .01) than healthy controls. Although the e-TSST did not exacerbate these group differences, higher state anxiety at baseline (p = .03) and higher LF/HF ratio in response to an acute stressor (p < .001) were associated with more severe GI symptoms within the first 20 minutes following the e-TSST. Importantly, IBS patients who were more physically active experienced less severe GI symptoms during that same timeframe (p = .03). Conclusion: Physical activity may be a promising lifestyle factor for lessening GI symptom severity in response to an acute stressor. / Thesis / Master of Science in Kinesiology

Social support has been linked to positive health outcomes. Specifically, having available support from a friend may act as a buffer to the negative effects of stress on cardiovascular reactivity. Relationship quality is an important moderator of this effect. The purpose of this study was to examine how cardiovascular reactivity is affected by relationship quality within friendships and whether the length of relationship and frequency of contact may moderate the effect. 134 healthy male and female adults (and their same-sex friend) were recruited to participate. Results revealed no significant difference between subjects interacting with supportive friends compared to interacting with ambivalent friends on cardiovascular reactivity. Length of relationship was independently associated with higher cardiac output (CO) and lower total peripheral resistance (TPR), but there was no statistical interaction between length of relationship and relationship quality. Frequency of contact was not a significant predictor of cardiovascular reactivity and no statistical interaction was found between frequency of contact and relationship quality. This study provides some evidence that length of relationships may be important to consider in future studies examining stressful relationships.

Mindfulness has historically been cultivated via formal meditation practice and the majority of meditation research examines individuals with extensive training or participants in Mindfulness based stress reduction programs that require considerable expense, a trained facilitator, and take approximately 8 weeks to complete. However, current literature does not speak directly to those who do not have the time or ability for such commitments. Formal mindfulness meditation practice and interventions reduce stress in various populations; however, the outcomes of a one-time intervention are relatively unknown. This study aims to examine whether a one-time (20-min) mindfulness meditation intervention would improve cardiovascular variables during acute stressors in a meditation naïve sample when compared to a control group. Fifty-eight (58) normotensive undergraduate students (27 males, 31 females) with no prior meditation experience were randomly placed into either a treatment group that participated in one-time 15-minute audio training session on mindfulness meditation or a control group which listened to an audio health article. Following the training, participants participated in a psychosocial stressor modeled after the Trier Social Stress Test. Heart rate and blood pressure were assessed before and after the intervention and during the stress task. Results showed the mindfulness meditation condition group was effective in decreasing blood pressure response during the study, when compared to the control group. These results indicate that brief meditation training has beneficial effects on cardiovascular variables. These findings suggest that the benefits of a brief one-time mindfulness meditation intervention can be recognized immediately after a brief training treatment.

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