Sex steroids influence the storing of fat, and differences in the distribution of fat are a typical secondary sexual characteristic. Androgens act on fatty tissues in males either directly through stimulation of the androgen receptor or indirectly through aromatization of the estrogen receptor. Androgens can be classified as aromatizable or non-aromatizable. Testosterone (T) is the main aromatizable androgen, while its metabolite dihydrotestosterone (DHT) is a non-aromatizable androgen that acts only through the androgen receptor. It is precisely this difference in having activity only through the androgen receptor that has given rise to the hypothesis concerning the differing effects of DHT and T on body composition, with DHT possibly being responsible for male-type fat distribution. As part of my post-graduate studies we analyzed the dependence serum levels of T and DHT on age, as well as changes in their ratio with age. Further, we sought relationships between aromatizable and non-aromatizable androgens and metabolic and anthropometric parameters. We also focused on following any changes in steroidogenesis in obese males. We showed that before puberty the dominant androgen is rather DHT than T, that the fDHT/fT ratio during the life of adult males is constant, and that there is no evidence of a reversal...

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The current generation of cosmological hydrodynamical simulations offer new levels of fidelity in galaxy formation and evolution that can be benchmarked against observations. However, it is crucial that the comparison between the simulation products and observations is performed on level-ground. Using mock-observations of galaxies from hydrodynamical simulations with observational realism, an image-based comparison is enabled between the simulations and modern galaxy surveys that allow galaxy properties to be derived consistently. A new methodology is presented that provides an unprecedentedly comprehensive suite of observational realism to synthetic images of galaxies from simulations and performs detailed decomposition of their morphological structures. The crux of the methodology is that the same procedure for image-based surface-brightness decompositions of galaxy structures is employed for the simulations and observations -- facilitating a fair and unbiased comparison of galaxy properties. The methodology is piloted on galaxies from the Illustris simulation and is designed to enable comparison with galaxies from the Sloan Digital Sky Survery (SDSS). The biases from observational realism on the decomposition results for the simulated galaxies are characterized in detail using several controlled experiments. Then, the decompositions are used in a comparison of the galaxy size-luminosity and bulge-to-total vs. total stellar mass relations. The comparisons show that galaxies from Illustris contain too many discs and too few bulges at low masses M*/M☉≤11 relative to the SDSS. A comparison of the photometric and kinematic bulge-to-total is also enabled by the methodology. The comparison suggests that photometry tends to systematically under-estimate the bulge fractions relative to the kinematics -- allowing no discernible connection to be made between photo-bulges and kinematic bulges. Several possibilities that may be driving the bulge deficit in Illustris' low-mass galaxies are discussed, though particle resolution is argued to be the main culprit. The methodology that is presented in this thesis has broad applications to comparisons between computational and observational galaxy astronomy and stands to provide a wealth of feedback between each community. / Graduate / 0606 / cbottrel@uvic.ca

Finding the most cost-effective and environmental friendly way to treat and disinfect wastewater has been raising concerns around the world. Failure in performing disinfection of wastewater before returning it to the environment could have terrible consequences to human health and the ecosystem. The risks associated to continue with current practices have led to the creation of stringent regulations. In this research the HYDROPATH technology is tested while attaching a HydroFlow 60i unit to a reactor that works as a closed recirculation system. To determine the feasibility of the HydroFlow 60i unit as an alternative method to chlorine, the EPA method 1306 is used being Escherichia coli the unit of quantification. After performing several experiments modifying parameters such as conductivity and detention time, it was concluded that the HydroFlow 60i unit by itself would not able to replace current disinfection technologies, to meet EPA standards of E. coli removal.

T2K is a long baseline neutrino experiment which uses a beam of muon neutrinos, produced at J-PARC and detected at Super-Kamiokande, to study the neutrino oscillation parameters. The measurement of cross-sections in the T2K energies can constrain the uncertainties on the model predictions and help the oscillation analyses reach the necessary sensitivity to measure CP violation in the lepton sector. This thesis describes the measurement of the CC1 + cross-section in water using Run II-IV T2K data. The T2K near detector, ND280, is used to select a sample of CC1 + events having vertices in the water layers of the downstream ne-grained detector (FGD). The Time Projection Chambers (TPC) are used for the particle identi cation and to measure their momenta. The Electromagnetic Calorimeters (ECals) are used to reject events that produce electromagnetic showers coming from neutral pions. A Bayesian unfolding method with background subtraction and two control samples is used to extract the cross-section. The control samples constrain the background coming from interactions on carbon and deep inelastic scattering. The single di erential cross-section is presented as a function of the muon kinematics, the pion kinematics, the angle between the muon and the pion, and the reconstructed neutrino energy. A future long baseline experiment between J-PARC and Hyper-Kamiokande is presented as a natural continuation to the T2K experiment. Hyper- Kamiokande will be a next generation water Cherenkov detector with a total ( ducial) mass of 0.99 (0.56) million metric tons. A total exposure of 7.5MW 107 sec integrated beam power will lead to the measurement of CP to better than 19 degrees for all possible values of CP . CP violation in the lepton sector could be established at better than 3 (5 ) for 76% (58%) of the CP parameter space.

According to current cosmological theory, the rate of expansion of the universe depends on the average energy densities of matter, radiation, and a possible vacuum energy described by a cosmological constant, &Lambda;, in the Einstein equation.<p>Observations of galaxies and radiation, along with an assumption that we hold no special place in the universe, imply an isotropic and homogeneous energy distribution, for which the universal rate of expansion for most of the history of the universe may be constructed to depend only on present values of the dimensionless matter and vacuum energy density parameters, &Omega;_M and &Omega;_&Lambda;, respectively, and the present rate of expansion of the universe, H₀. Over the past decade, much progress has been made in determining the values of the three density parameters using a variety of independent methods. In particular, observations of type Ia supernovae in the late 1990s provided the first evidence that &Lambda; &ne; 0 and that universal expansion is accelerating.<p>This study has determined values for &Omega;_M and &Omega;_&Lambda; using the brightest quasars in the Sloan Digital Sky Survey Data Release 5, which are located at a range of distances - equivalently, a range of lookback times - that have not been accessible through any other observations. After fitting the apparent magnitudes of the brightest quasars at various redshifts to the distance modulus equation with a luminosity evolution term, values for the density parameters were determined to be &Omega;_M = 0.07 and &Omega;_&Lambda; = 1.13.

According to current cosmological theory, the rate of expansion of the universe depends on the average energy densities of matter, radiation, and a possible vacuum energy described by a cosmological constant, &Lambda;, in the Einstein equation.<p>Observations of galaxies and radiation, along with an assumption that we hold no special place in the universe, imply an isotropic and homogeneous energy distribution, for which the universal rate of expansion for most of the history of the universe may be constructed to depend only on present values of the dimensionless matter and vacuum energy density parameters, &Omega;_M and &Omega;_&Lambda;, respectively, and the present rate of expansion of the universe, H₀. Over the past decade, much progress has been made in determining the values of the three density parameters using a variety of independent methods. In particular, observations of type Ia supernovae in the late 1990s provided the first evidence that &Lambda; &ne; 0 and that universal expansion is accelerating.<p>This study has determined values for &Omega;_M and &Omega;_&Lambda; using the brightest quasars in the Sloan Digital Sky Survey Data Release 5, which are located at a range of distances - equivalently, a range of lookback times - that have not been accessible through any other observations. After fitting the apparent magnitudes of the brightest quasars at various redshifts to the distance modulus equation with a luminosity evolution term, values for the density parameters were determined to be &Omega;_M = 0.07 and &Omega;_&Lambda; = 1.13.