Genotypic characterisation of Giardia from domestic dogs in the USA

The first large-scale urban survey of Giardia infections in dogs was undertaken in the USA. It involved several locations in the Western United States with Giardia isolates from microscopy-positive samples characterised by multi-locus PCR and sequencing. A high prevalence of Giardia was confirmed in asymptomatic domestic dogs, and for the first time, provides evidence that zoonotic assemblages/subgroups of Giardia occur frequently in domestic dogs living in urban environments, and more frequently than the dog specific assemblages

Swiss Bank Secrecy and United States Efforts to Obtain Information from Swiss Banks

The United States has utilized numerous techniques to penetrate bank secrecy, with varying degrees of success. The United States and Switzerland have signed several agreements relating to bank secrecy and its role in United States criminal investigations. These efforts have allowed United States authorities to obtain normally privileged information in numerous investigations over the past ten years, although some confusion as to what information is available still exists today. Two recent events have expanded the scope of information available to United States investigators and alleviated some of the confusion. In November 1987 the United States and Switzerland exchanged a Memorandum of Understanding which granted United States authorities greater access to Swiss bank records. In addition, in December 1987 the two houses of the Swiss Parliament enacted a new law making insider trading illegal. This law will allow United States securities fraud investigators greater leeway in obtaining normally privileged financial records from Swiss banks. These two developments make Swiss bank secrecy almost obsolete as a means of hiding ill-gotten gains from United States investigators. By this summer, United States authorities can expect to have access to Swiss bank records in almost all future investigations

Nanoclay-Based Solid-Amine Adsorbents for Carbon Dioxide Capture

The objective of this research was to develop an efficient, low cost, recyclable solid sorbent for carbon dioxide adsorption from large point sources, such as coal-fired power plants. The current commercial way to adsorb CO 2 is to use a liquid amine or ammonia process. These processes are used in industry in the sweetening of natural gas, but liquid based technologies are not economically viable in the adsorption of CO2 from power plants due to the extremely large volume of CO2 and the inherent high regeneration costs of cycling the sorbent. Therefore, one of the main objectives of this research was to develop a novel sorbent that can be cycled and uses very little energy for regeneration.;The sorbent developed here is composed of a nanoclay (montmorillonite), commonly used in the production of polymer nanocomposites, grafted with commercially available amines. (3-aminopropyl) trimethoxysilane (APTMS) was chemically grafted to the edge hydroxyl groups of the clay. While another amine, polyethylenimine (PEI), was attached to the surface of the clay by electrostatic interactions. To confirm the attachment of amines to the clay, the samples were characterized using FTIR and the corresponding peaks for amines were observed. The amount of amine loaded onto the support was determined by TGA techniques. The treated clay was initially analyzed for CO2 adsorption in a pure CO 2 stream. The adsorption temperatures that had the highest adsorption capacity were determined to be between 75°C and 100°C for all of the samples tested at atmospheric pressure. The maximum CO2 adsorption capacity observed was with nanoclay treated with both APTMS and PEI at 85°C. In a more realistic flue gas of 10% CO2 and 90% N2, the adsorbents had essentially the same overall CO2 adsorption capacity indicating that the presence of nitrogen did not hinder the adsorption of CO2. Adsorption studies in pure CO2 at room temperature under pressure from 40-300 PSI were also conducted. The average adsorption capacity for the adsorbents did not change significantly over the range of pressures studied, indicating that the uptake of CO2 was due mainly to chemical reaction and not to the physical absorption of CO2. The average CO2 adsorption capacity at 300 psi and room temperature for clay treated with APTMS alone was 7.6 wt% CO2. The combination of APTMS and PEI treatment increased the average adsorption capacity to 11.4 wt% CO2.;The regeneration method for the majority of the adsorption tests employed pure N2 at 100°C as a sweep gas, and it was successful in regenerating the adsorbent. The regeneration of the adsorbent was also studied with pure and humid CO2 at 155°C. Using CO2 as a sweep gas for regeneration is more commercially relevant and was able to regenerate the sorbents. Vacuum regeneration and the stability of the adsorbents to water vapor were also studied. Our studies showed that the developed adsorbents were able to adsorb CO2 at atmospheric conditions using pure CO 2 as well as 10% CO2 and 90% nitrogen. Additionally, the adsorbents developed have the potential to be cycled using commercially applicable regeneration schemes. While these results are comparable to results of other emerging CO2 adsorption technologies, our adsorbent has the benefit of a very cheap support, and it could provide a commercially useful CO 2 adsorbent

The Roles of daf-6 and Cell-Cell Interactions in Sensory Organ Morphogenesis

The development of multicellular organs depends on the regulation of cell shape, position, and orientation. The genetic regulation of these morphogenetic processes is poorly understood. As a model for organ morphogenesis, I studied the development of the Caenorhabditis elegans amphid sensory organ. Sensory organs in diverse species are often composed of neuronal sensory endings accommodated in a lumen formed by ensheathing epithelia or glia. The generation of this structure may require cell-autonomous factors that control lumen formation, as well as cell non-autonomous factors that coordinate the morphogenesis of the lumen with the resident neuronal processes. Understanding these processes would provide insight into lumen formation, glia morphogenesis, and cell-cell interactions during development, especially neuronal regulation of glia morphogenesis. In this thesis, I identify and characterize genes required for lumen formation in the amphid sensory organ. First, the gene daf-6 is required cell autonomously during amphid lumen formation. daf-6 encodes a Patched-related protein that is a member of a previously uncharacterized sub-family of sterolsensing domain containing proteins. Interestingly, daf-6 is expressed and required in several tubular structures, such as the excretory system and vulva. Thus, a similar genetic pathway is required for the formation of different lumens. Secondly, I conducted a forward genetic screen and identified and characterized mutations that suppress the lumen formation defects in daf-6 mutants. Finally, by examining mutants defective in sensory neuron process formation, I showed that amphid lumen shape is determined by its resident sensory endings