The current National Academies of Sciences, Engineering and Medicine (NASEM) dry matter intake (DMI) prediction models are inadequate for DMI prediction of beef cattle in the Northern Great Plains. Four studies were conducted to account for additional variation in DMI and average daily gain (ADG) caused by weather variables. Experiment 1 and 2 had 13,895 steer-weeks observations, experiment 3 had 13,739 steer-weeks observations, and experiment 4 had 2,161 cow-weeks observations, respectively. Experiment 1 examined the influence of ambient temperature and solar radiation on DMI of beef steers. In experiment 2, 3, and 4, we examined the influence of ambient temperature, range of temperature, dew point, solar radiation, wind speed and their lags (two-week lag and monthly lag) on DMI of beef steers, ADG of beef steers, and DMI of beef cows, respectively. After adjusting for week of the year, linear and quadratic relationships of predictor variables on response variables were evaluated. In experiment 1 and 2, body weight (BW) had both linear and quadratic relationship with DMI of steers. In experiment 3 and 4, BW had a linear relationship with ADG of steers and DMI of cows, respectively. Week of the year, BW, and dietary energy density (NEm) were accounted for in the base model in experiment 1, 2 and 4 while in experiment 3, DMI was also accounted for. For the models, stepwise regression procedure was utilized. In experiment 1, ambient temperature and solar radiation interacted (P = 0.0001) and accounted for additional variation in DMI of beef steers. In experiment 2, weather variables and their interactions (P = 0.0001) accounted for additional variation in DMI of beef steers. In experiment 3, weather variables (P = 0.0001) accounted for additional variation in ADG of beef steers. In experiment 4, wind speed interacted (P <0.001) with ambient temperature and range of temperature which all accounted for additional variation in DMI of beef cows. These studies show that weather variables interact and cause variation in DMI and ADG in beef cattle. This has helped in better understanding the relationship between weather variables with DMI and ADG. This will improve the accuracy of DMI and ADG prediction equations and help beef cattle producers in managing their feed resources more efficiently.

The output characteristics of five compression hearing aids in response to a transient signal were examined to determine if, the input-output function (i.e. output levels of the hearing aid as a function of input level) for a transient signal could be made to approximate that of a continuous signal, by activating the compression circuit with a second signal (activator). Input-output functions for three input compression and two output compression hearing aids were obtained in order to determine if: 1. the automatic gain control (AGC) was activated by the second signal and the transient signal output approximates that of a continuous tone, and 2. if the second tone was evident in the output of the hearing aid and thereby potentially being an interfering factor in aided auditory brainstem response (ABR) measurement.

A healthy in utero environment is essential for achieving optimal outcomes for women and their children. Gestational weight gain (GWG) has been shown to impact current and future maternal-infant health outcomes. Suboptimal weight gain during pregnancy (defined by the Institute of Medicine GWG guidelines) has been linked to several complications and is implicated in the inter-general cycle of obesity. Understanding contributors to GWG and intervening during pregnancy with healthy behaviour strategies may have a multi-generational effect for chronic disease prevention. The objective of the first study of this thesis was to examine the association between i) eating habits during pregnancy, ii) advice from family or friends about GWG, and iii) personal effort to stay within weight gain limits, and meeting GWG recommendations. Cross-sectional data were collected from pregnant and postpartum women who responded to the validated electronic maternal (EMat) health survey. Regardless of receiving advice about GWG, women self-reporting less healthy eating habits in pregnancy than before pregnancy, receiving advice from family/friends about GWG, and lower personal effort to stay within guidelines, had an increased odds of weight gain discordant with recommendations. The objective of the second study was to assess the short-term effect of the SmartMoms Canada application (app) usage on promoting adequate GWG and healthy behaviours. SmartMoms Canada is an app-based intervention designed to help pregnant women adhere to GWG guidelines and improve healthful behaviours. Pregnant women using the SmartMoms Canada app more frequently had a higher moderate-to-vigorous physical activity daily average when compared with women with a lower usage. Together, the EMat and SmartMoms results from this thesis contribute to identifying and mitigating potential factors associated with discordant GWG and healthy behaviours.

Background: In the pregnant population, being physical active and meeting gestational weight gain (GWG) guidelines have numerous health benefits for both mother and infant. Markers of lipid metabolism are known to be influenced by these two variables in the non-pregnant population. However, the relationship between physical activity (PA) and GWG on lipid markers has yet to be assessed during pregnancy. My thesis aims to address this gap in the literature. Methods: The first objective of my thesis was to examine the relationship between maternal PA and GWG on gross measurements of fetal and placental development (n=40). Specifically, three markers of placental efficiency (Pl-E) were examined (birthweight [BW], BW-to-placenta weight ratio, and residual BW). The second objective of my thesis was to analyze maternal serum lipid and glucose markers (n=40), in mid (24-28 weeks) and late (34-38 weeks) gestation as well as from the umbilical cord (UC) as they relate to both PA and GWG. The third objective of my thesis was to explore how PA level and GWG status affect markers of lipid metabolism in term placenta (n=31). Markers of placental lipid transport (FATP1, FABP4, FAT/CD36) were assessed at the protein level, and enzymatic activity of placental lipoprotein lipase was also measured. Lastly, placental lipid storage was assessed by examining triglyceride content, paired with lipid droplet staining. Results: There was no relationship between PA independently or in combination with GWG on any Pl-E markers. A significant association was found between GWG and BW in women who gained weight excessively compared to insufficiently. Neither PA nor GWG categorization was associated with maternal lipid and glucose markers. Total cholesterol levels measured in UC serum were significantly lower in women categorized as active throughout pregnancy (p<0.0001) or whose activity dropped in late gestation (p<0.0001) compared to those who were inactive v throughout gestation. Glucose levels were lower in UC blood of women who gained weight appropriately in mid-gestation compared to those who gained insufficient (p=0.040) or excessive (p=0.021) weight. In terms of placental fatty acid transport, there was a significant interaction between PA status and GWG categorization and placental FATP1 protein expression (F=14.62, p<0.0001). Finally, while no differences were found in placental lipid droplet staining, the droplets were more likely to be clustered within the syncytiotrophoblast border. Conclusion: In conclusion, maternal PA had no association with Pl-E, while GWG was only associated with BW. My thesis work found that while maternal serum lipid markers were not associated with PA and GWG, both maternal PA and GWG status were related to changes in UC and placental lipid markers throughout pregnancy. In combination with previous research from our lab, it is suggested that women who are physically active during pregnancy, and gain weight appropriately may be transporting fewer nutrients (i.e. fatty acid, glucose, cholesterol) to the placenta than those who are inactive, yet simultaneously increasing metabolization. Future research should further investigate these findings by performing functional experiments.

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Syftet med den här undersökning var att se hur mycket jag som gitarrist och producent kan efterlikna olika typer av high gain elgitarrljud. Jag använde mig av modelleringsförstärkare och rördrivna elgitarrförstärkare med högtalarelement. Frågan var vilken av dessa förstärkartyper kommer egentligen närmast ett original? Hur mycket av karaktären ljudet sitter i anslag jämfört med mängd och karaktär av distorsion? För att få en överblick på hur bra jag lyckades att efterlikna olika gitarrljud har jag arbetat med tre olika soundalikes. Dessa tre låtar är tre exempel på hur olika high gain elgitarrer kan låta inom genren metal. Resultatet mynnade ut i att jag som gitarrist fick reda på hur mycket av ett elgitarrljud som faktiskt sitter i min spelstil och anslag. Jag fick även reda på att den förstärkartyp jag är van vid har en stor påverkan på hur jag skapar och försöker efterlikna olika ljud.

Objective: The purpose of this study was to assess the feasibility of conducting a prospective cohort study during early pregnancy (<24 weeks gestation) examining the psychological factors associated with excessive pregnancy weight gain. Study Design: Women who had at least 1 prenatal care visit, had a live singleton gestation and were able to read English were eligible to enroll in the study. Women completed the self-administered survey at their prenatal clinics in Hamilton and Brantford, Ontario, Canada. Final pregnancy weight was obtained from women’s clinical charts. Results: All approached clinics agreed to participate in the study (100% clinic agreement). Five hundred thirty women completed the enrolment survey, which was a 90.0% uptake rate. An average of 6 women enrolled each week at less than 24 weeks gestation. Less than 10% of data were missing for all survey questions and outcome data (final pregnancy weight) was available for all but one participant (97.3%). Final pregnancy weights were obtained a median of 1.0 days (interquartile 0.0-3.5 days) prior to delivery. No psychological factors were significantly associated with the odds of gaining above the 2009 IOM/Health Canada guidelines in the exploratory univariate analysis. Conclusion: All feasibility outcomes demonstrated that conducting a full-scale study in Southwestern Ontario would be feasible. Conducting a full-scale study may identify associations between psychological factors and excessive pregnancy weight gain. / Thesis / Master of Science (MSc)

The gas turbine engine is an integral component of the global energy infrastructure and, through widespread use, contributes significantly to the emission of harmful pollutants and greenhouse gases. As such, the research and industrial community have a significant interest in improving the thermal efficiency of these devices. However, after nearly a century of development, modern gas turbine technology is nearing its realizable efficiency limit. Thus, using conventional approaches, including increased compression ratios and turbine inlet temperatures, only small future efficiency gains are available at a high cost. If a significant increase in gas turbine engine efficiency is to be realized, a deviation from this convention is necessary. Pressure gain combustion is a new combustion technology capable of delivering a step increase in gas turbine efficiency by replacing the isobaric combustor found in conventional engines with an isochoric combustor. This modification to the engine's thermodynamic cycle enables the loss in stagnation pressure typical of an isobaric combustor to be replaced with an overall net gain in stagnation pressure across the heat addition process. In this work, a pressure gain combustion technology known as the resonant pulse combustor is studied experimentally and numerically to bridge the gap between lab-scale experiments and practical implementations. First, a functional novel active valve resonant pulse combustor was designed and prototyped, thereby demonstrating naturally aspirated resonant operation with an air inlet valve-driven at a fixed frequency. Then, a series of experimental and numerical studies were carried out to increase the pressure gain performance of the combustor, and the performance and applicability of the active valve resonant pulse combustor concept were then experimental demonstrated in atmospheric conditions with both gaseous and liquid hydrocarbon fuels. Finally, the improved active valve resonant pulse combustor's pressure gain and NOX emissions performance was characterized within a high-pressure shroud in a configuration applicable to gas turbine applications and with varied inlet pressures extending up to 3 bar. This study demonstrates the low NOX capability of the pulse combustor concept and provides insight into how the device's performance may scale with increasing inlet pressure, as would exist in a practical application.

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Background: In recent history, there have been significant increases in both soft drink consumption and the prevalence of obesity throughout the developed world. To help curb the obesity epidemic, a better understanding of the behaviors contributing to weight and fat gain is vital. Objective: To examine the extent to which soft drink consumption is predictive of changes in body composition in middle-aged women over a 4-year period, while statistically controlling for age, energy intake, physical activity, and menopause status. Design: A prospective cohort design over 48 months with no intervention. Self-reported soft drink consumption was used to predict changes in body weight and body fat percentage over the study period. Subjects included 170 healthy women (mean: 41.5 yrs at baseline). Soft drink consumption and menopause status were measured by questionnaire. Body weight was assessed using a calibrated, electronic scale, and total body fat percentage was measured using dual energy x-ray absorptiometry (DEXA). Energy intake was estimated using 7-day, weighed, food records. Results: Women who primarily consumed sugar-sweetened soft drinks gained significantly more weight than those who consumed diet soft drinks or no soft drinks (p = 0.022), even after controlling for confounding variables, except energy intake, which weakened the relationship by 28%. Changes in body fat were unrelated to the type of soft drink consumed. Women who consumed 7+ soft drinks per week gained significantly less body fat (p = 0.015) and body weight (p = 0.052) over the 4-year study compared to women who consumed fewer soft drinks per week. Further investigation revealed that women who consumed 7+ soft drinks per week did so almost exclusively in the form of diet soft drinks (87%). Conclusions: Drinking sugar-sweetened soft drinks significantly increases risk of weight gain compared to consuming diet soft drinks or no soft drinks over a 4-year period. It appears that this relationship is partly due to differences in energy intake among those who drink different types of soft drinks. Thus, it appears that consuming diet soft drinks or no soft drinks instead of sugar-sweetened soft drinks may be a worthwhile method of preventing weight gain.