This thesis describes several aspects of cosmic ray composition studies using the Utah Fly's Eye and High Resolution Fly's Eye (HiRes) detectors. The Fly's Eye detector utilises the atmospheric fluorescence technique to measure the development of cosmic ray cascades as they pass through the atmosphere. This is complementary to the surface array technique, as used by the Akeno experiment in Japan, which measures the electromagnetic and muon content of air showers at a single observation level. For some time it was thought that Fly's Eye and Akeno gave inconsistent composition results. In Chapter 4 I show that the inconsistency is due, for the most part, to a difference in the assumptions made about hadronic interactions. In Chapter 5 I present analysis of the composition between 10^17 and 10^18 eV using the prototype High Resolution Fly's Eye (HiRes) detector in coincidence with the Michigan Muon Array (MIA). The hybrid nature of these measurements gives us more information about cosmic ray showers than either technique on its own. The consistency or otherwise of the composition measured by the two detectors is discussed. Finally, in Chapter 6, I discuss a method of extracting the total proton-proton cross section from the cosmic ray data. This information is of interest because it is derived at centre of mass energies much higher (by at least an order of magnitude) than those currently accessible by collider experiments. I present a preliminary calculation of the cross section using the HiRes/MIA hybrid data set. / Thesis (Ph.D.)--Department of Physics and Mathematical Physics, 2001.

Thesis (Ph.D.)--Ohio University, November, 2007. / Abstract only has been uploaded to OhioLINK. Includes bibliographical references (leaves 174-186)

Thesis (M. S.)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Dickson, Robert; Committee Member: Brown, Ken; Committee Member: Curtis, Jennifer; Committee Member: Payne, Christine; Committee Member: Perry, Joseph.

Thesis (M.S.)--University of North Carolina at Wilmington, 2005. / Includes bibliographical references (leaves: [87]-88)

Call number: LD2668 .T4 1986 K55 / Master of Science / Human Nutrition

No description available.

A dissertation submitted in compliance with the requirements for the Masters Degree in Technology in Biotechnology, Durban University of Technology, 2011. / Under environmental stress, most microalgae produce intracellular neutral lipids as a storage mechanism. In the biotechnology industry, these lipids are extracted and converted to microalgal biodiesel; however the extent of the stress is not measured for optimum lipid accumulation. In the series of studies undertaken, Pulse Amplitude Modulated (PAM) fluorometry was used to measure three types of physiological stress on Chlorella sp., a freshwater microalgal species. Biomass and lipid yields were also used as indicators of the induced stress conditions. Firstly, nutrient induced physiological stress and the subsequent synthesis of cellular neutral lipids was investigated. / M

Yes / The intrinsic fluorescence of aquatic organic matter emitted at 350 nm when excited at 280 nm correlates widely with water quality parameters such as biochemical oxygen demand. Hence, in sewage-impacted rivers and groundwater, it might be expected that fluorescence at these wavelengths will also correlate with the microbial water quality. In this paper we use a portable fluorimeter to assess the relationship between fluorescence intensity at this wavelength pair and Escherichia coli enumeration in contrasting river catchments of poor water quality: in KwaZulu-Natal, S. Africa and the West Midlands, UK. Across all catchments we demonstrate a log correlation (r = 0.74) between fluorescence intensity and E. coli over a seven-log range in E. coli enumerations on non-perturbed (unfiltered) samples. Within specific catchments, the relationship between fluorescence intensity and E. coli is more variable, demonstrating the importance of catchment-specific interference. Our research demonstrates the potential of using a portable fluorimeter as an initial screening tool for indicative microbial water quality, and one that is ideally suited to simple pollution scenarios such as assessing the impact of faecal contamination in river or groundwater at specific sites. / This research was funded by the UK EPSRC Grant EP/H003061/1.

Proliferating cell nuclear antigen (PCNA) is an essential protein in the cell. It is involved in transcription and many types of DNA repair and replication. Homologues of this protein are found in all orders of life. The high level of conservation and essential nature of PCNA infers that it may be a potential drug target for anti-caner drugs in humans and also a potential anti-parasitic target. X-ray structures of PCNA from Homo sapiens (Hs), Schizosaccharomyces pombe (Sp) and Leishmania major (Lm) are now available and can be used as a template for structure based drug design. In this work PCNA from these three species have been prepared in milligram quantities for biochemical and biophysical studies. The previously unknown structure of LmPCNA has been solved in an uncomplexed form and also complexed with a dodecapeptide to a resolution of 3.0Å. A comparison of PCNA structures and their peptide complexes for the three species identifies structural differences which may be relevant in analysing thermodynamic contributions of binding. All eukaryotic PCNA molecules exist as ring shaped trimers which form around DNA. In this work the oligomeric state of LmPCNA has been determined to be hexameric both in solution and in the crystal. It has also been hypothesised that HsPCNA is hexameric however these would seem to form hexamers in which the trimeric rings associate “back-to-back” while LmPCNA trimers would seem to associate “face-to-face”. The binding affinities for these three PCNAs have been determined with a selection of peptides derived from the Hs p21 protein. This work has shown, using a selection of different techniques including Surface Plasmon Resonance (SPR), Isothermal Titration Calorimetry (ITC) and Dynamic Scanning Fluorimetry (DSF); that HsPCNA and SpPCNA have similar affinities for a 12mer peptide (Kd of ~1μM) however LmPCNA shows significantly weaker interactions (Kd of ~10μM). This is most likely due to divergence in the sequence and structure of LmPCNA. A systematic investigation by SPR on the effect of peptide linker length on binding has been carried out using a series of synthesised peptides with different lengths of chemical spacer. The series of streptavidin immobilised peptides show that longer spacers are required for the recovery of the PCNA peptide binding affinity. The results presented in this work indicate that a linker length of at least 20Å is required for measurable protein binding activity. This interaction is improved with longer peptide spacers.

O rio Paraíba do Sul, após formar o reservatório do Funil, abastece cidades ribeirinhas e a cidade do Rio de Janeiro. A INB, uma empresa da área nuclear, está localizada na margem norte deste reservatório. Neste trabalho, Ag, Al, As, Ba, Cd, Co, Cr, Fe, Mn, Ni e Pb foram determinados por ICP OES em água e sedimentos em pontos a montante e a jusante do Funil e neste. Urânio, usando fluorimetria, também foi determinado em amostras coletadas a montante e a jusante do ponto de descarga de efluentes da INB, no ribeirão da Água Branca. O estudo não mostrou evidências que a INB está provocando impacto ambiental nesse ribeirão. As, Ni e Pb em todos os pontos de amostragem e Al, Cr e Fe na maioria desses pontos apresentaram concentrações em água acima do máximo permitido pela CONAMA 357. A maioria dos elementos apresentou concentrações nas amostras de água a montante do reservatório do Funil superiores às verficadas a jusante, para ambas as estações chuvosa e seca. Os sedimentos estão impactados por As, Cd, Cr e Pb em quase todos os pontos estudados. / The Paraiba do Sul River after forming the Funil Reservoir serves as the major source of potable water for downstream cities and for the city of Rio de Janeiro. INB, a company of the nuclear area, is located in the north margin of this reservoir. In the present study, Ag, Al, As, Ba, Cd, Co, Cr, Fe, Mn, Ni and Pb were determined by ICP OES in water and sediments samples at points upstream and downstream from Funil and in this one. Uranium, using fluorimetry, was also determined in samples collected upstream and downstream from the INB effluent discharge point at the Água Branca Creek. The study did not show evidences that INB is provoking environmental impact in this creek. As, Ni and Pb in all the sampling points and Al, C and Fe in most of those points exceeded the CONAMA 357 standards for water. Most of the elements presented concentration in the water samples at the points upstream from Funil reservoir higher than those downstream, for both rainy and dry seasons. Sediments are impacted by As, Cd, Cr and Pb in almost all the studied points.