Analysis

The dauer larva is an alternate larval stage which allows the nematode C. elegans to survive environmestress during development. Dauer formation requires autophagy, a cellular process responsible for degrading and recycling cytoplasmic components. I investigated the role of a spinster orthiolog, C13C4.5, by examining the effects of C13C4.5 loss-of-function and by generating a transgenic strain which expressed a C13C4.5::GFP fusion protein. Under normal conditions C13C4.5::GFP is expressed diffusely in the intestine, but under autophagy-promoting conditions the expression pattern becomes more punctate. This is consistent with localization of C13C4.5 to autophagolysomoes during autophagy, as has been shown for spinster in D. melanogaster. Loss of C13C4.5 function in a dauer-constitutive mutant resulted in a reduction in the proportion of animals entering into the dauer stage. Together these data suggest that C13C4.5 is involved in dauer formation and the autophagy pathway.

Gold is a highly prized metal whose ore deposits are continually being mined and depleted. With the increasing scarcity of continental gold ores, gold miners and scientist are turning to the sea as one alternate source of this precious metal. But the problem arises in determining which parts of the ocean to mine. Ideally the area with the greatest concentration of gold would be the best place to start but determining an accurate concentration of gold in a sample of seawater is difficult for various reasons. The main reason being gold's extremely low concentration in seawater, averaging at about13 [sic] parts per trillion. This study deals with detecting trace amounts of gold in seawater. The first step in the analysis involves pre-concentrating gold in seawater using an ion exchange resin, Chelexª -100, and optimizing the experimental conditions. Then the chromatographic fractions are analyzed using a graphite furnace atomic absorption spectrometer. The results from several trials are presented in this study.

Phosphorus (P) is required for all living organisms. Fully oxidized pentavalent (+V) is the principal form in organisms, however studies on Desulfotignum phosphitoxidans show the enzymatic metabolism of reduced P oxyanions. Thus a natural source of reduced P is expected. Geothermal waters are naturally occurring reducing environments and ion chromatography has been used for the detection of submicromolar concentrations of P, yet the detection of reduced oxyanions is complicated by fluoride and hydrogen carbonate with similar elution times as hypophosphite(+I) and phosphite(+III) respectively. Studies had shown that simplifying the matrix through pretreatment with silver and sulfonic acid cartridges improves IC limits of detection (LODs). The effects of pretreatment are dependant upon the total concentration of ions in solution. The purpose of this study is to determine IC phosphorous oxyanion LODs and to maximize signals by analyzing the relationship between filtering techniques, effective concentration of P oxyanions, and total ions in the matrix.