Water treatment facilities have been relying on indicator bacteria to assess the quality of water for decades. The purpose of this group of studies is to investigate the predictive capabilities of conventional and alternative indicators for pathogenic microorganisms in disinfection processes and treated wastewater effluents. In addition, the possibility that diversity of indicator bacteria, as well as overall bacterial diversity, correlate with fecal contamination in water bodies has been investigated. Indicator organisms (total coliforms, fecal coliforms, enterococci, C. perfringens, and coliphages) as well as pathogens (enteroviruses, Giardia, and Cryptosporidium) were enumerated from six wastewater treatment facilities at various stages of treatment. Statistical analyses were conducted to determine if the indicator organisms (individually or as a set) could predict the presence or absence of pathogens. Single indicator organism analysis failed to correlate with the occu rrence pathogens, thus monitoring a suite of indicator organisms may be a better measure to predict the presence of pathogens. The product of chlorine residual concentration and contact time (CT) was identified as a factor for determining the log10 reduction of enteric viruses in wastewater treatment facilities that used chloramines for disinfection.Samples were also collected from river waters and sediments in watersheds with different human population densities to identify the impact of anthropogenic activities on bacterial diversity. 16S rRNA restriction fragment length polymorphism (RFLP), ribotyping, and denaturing gradient gel electrophoresis (DGGE) were used to determine total coliform, Escherichia coli, and bacterial community population structures, respectively. The concentrations of indicator organisms were significantly different among the river sites in sediments, but not in water column. The population diversity measurements were not significantly different among the river sites; while the indicator population and bacterial community structures were dissimilar in water column vs. associated sediment samples. Accumulation curves demonstrated that greater than 20 isolates must be sampled at most of the sites to represent the dominant populations. A better understanding of the relationship between the indicator organisms and pathogens as well as knowledge of the ecology of indicator organisms in pristine and anthropogenically impacted waters may contribute to water quality restoration and public health protection.

Water quality worldwide is assessed by enumeration of fecal indicator bacteria (FIB) (fecal coliforms, Escherichia coli, and enterococci) intended to act as surrogates for human enteric pathogens. In environmental waters, this predictive relationship is confounded by many possible sources of FIB with varying implications for human health. Many physico-chemical and biological factors influence the fate of enteric pathogens and FIB in aquatic habitats, but are poorly understood, thus limiting our understanding of the usefulness of FIB as fecal pollution indicators. These studies explored the field application of a “toolbox” approach to microbial source tracking (MST) intended to discriminate between human and non-human fecal pollution: a) in a Florida estuary used for shellfishing and recreational activities and b) at public beaches before and after remediation of wastewater infrastructure. Lastly, the effects of environmental factors (sediments, protozoa, sunlight) on survival of culturable E. coli were investigated in freshwater and seawater mesocosms simulating environmental conditions. Detection of a human- associated MST marker (the esp gene of Enterococcus faecium) at sites with suspected sewage contamination indicated that human fecal pollution is impacting water quality in Wakulla County, while Lagrangian drifters designed to follow current and tidal movement suggested that local hydrology plays an important role in bacterial transport and deposition pathways. Elevated FIB concentrations and frequent detection of human-associated MST markers (esp and human polyomaviruses) identified human sewage pollution at a public beach, facilitating remediation efforts (sewage main repair, removal of portable/abandoned restrooms), followed by significant decreases in FIB concentrations and MST marker detection. These studies show that comprehensive microbial water quality assessment can reliably identify contamination sources, thereby improving pollution mitigation and restoring recreational water quality. Protozoan predation, freshwater vs. seawater habitat and sediment vs. water column location affected the concentration of culturable E. coli in outdoor mesocosms. Sediments offered a refuge from predation where freshwater vs. seawater habitat was amore important determinant of survival. These findings provide important insight into the ecology of E. coli and their natural predators in aquatic habitats and underscore the inherent effect different habitats play in their survival.

Microbial water quality is generally assessed using fecal indictor organisms; however host-specific microbial source tracking (MST) methodologies can be employed to differentiate sources of fecal pollution. The central goal of this research was to develop and validate a QPCR assay for the quantification of two human-specific polyomaviruses (HPyVs) in environmental water samples. These viruses are prevalent worldwide and produce lifelong, asymptomatic viruria in immunocompetent individuals. A Taqman® quantitative PCR (QPCR) assay based on the conserved T-antigen of two HPyVs (JCV and BKV) was developed and optimized (Chapter 2). HPyVs were detected in a high proportion of human-associated waste samples (e.g. sewage) and were not detected in animal excrement samples (Chapter 2). The effects of ultraviolet radiation, temperature, and salinity on the persistence of HPyVs in water were reported in Chapter 3. Laboratory studies analyzing the effects of various UV doses, temperatures, and/or salinities demonstrated high doses of UV were required to significantly decrease the detection of HPyVs DNA and salinity stabilized pure cultures of HPyVs virus particles at high temperatures (25°C and 35°C). Solar radiation as well as potential predation from microorganisms in sewage significantly reduced the persistence of HPyVs DNA in outdoor mesocosm studies (Chapter 3). An improved method to extract human polyomavirus (HPyVs) DNA from environmental water samples was developed, and the recoveries were larger and more consistent over a range of DNA concentrations as compared to the standard protocol (Chapter 4). In the California beaches study (Chapter 4), the presence of HPyVs by either QPCR or PCR had a high degree of matching results with the adenoviruses (83-91%), Methanobrevibacter smithii marker (82-92%) and moderate degree of matching results with the human-associated Bacteroidales spp. marker (57-80%) (Chapter 4). HPyVs were detected in the presence of various pathogens including: Giardia spp., Cryptosporidium spp., Vibrio spp., enteroviruses, and noroviruses (Chapter 5). The presence of HPyVs in relatively high concentrations of sewage and the specificity of HPyVs combined with the relatively conservative persistence of HPyVs when exposed to environmental conditions and the correlation of HPyVs with pathogens demonstrates that this assay is a useful MST method to detect human sewage.

Current research is revealing that stormwater can carry pathogens and that this stormwater is entering wastewater treatment facilities. During periods of intense rainfall, not only can stormwater carry higher amounts of pathogens, but it also increases the flow rate to the wastewater treatment facility. In many instances, the flow rate exceeds the facilities' treatment capacity and can impact treatment performance. The purpose of this study was to identify whether wastewater treatment is impaired during periods of increased rainfall, and to compare current policies that address this issue. The study was conducted using a case study approach to analyze historical precipitation and wastewater treatment data from facilities located in Clearwater and St. Petersburg, Florida. The effluent from the biological nutrient removal system operated at the facilities located in Clearwater was compared to the effluent from the activated sludge treatment system operated by the facility located in St. Petersburg. Statistical analyses were conducted to identify significant differences in either the loading or performance of wastewater treatment facilities under wet and dry flow conditions. In this case, the Clearwater facilities operating below their treatment capacity were better equipped to handle peak wet weather flows and efficiently treat wastewater than the St. Petersburg facility which has a less advanced treatment system and was operating at and above its treatment capacity.

Siesta Key Beach, located on the Gulf Coast of Florida, is frequently mentioned among the top ten beaches in the US. In summer 2004, high levels of indicator bacteria caused health warnings to be posted, and a storm drainage system was implicated as a possible source of microbial contamination. A study was initiated to determine whether indicator bacteria that persisted in the stormwater system could contribute to high microbial loads in receiving waters. Two sampling events, one within 48 hours of a rain event and the other during dry conditions, were conducted. Water and sediment samples were taken at various sites from the storm drainage system to the beach. Fecal coliforms and Enterococcus spp. were enumerated, and genotypic fingerprints of E. coli and Enterococcus spp. were generated by BOX-PCR. Diversity of E. coli and Enterococcus populations was calculated with the Shannon-Weiner diversity index. Similarity of E. coli and Enterococcus populations was calculated with the population similarity coefficient. After the rain event, levels of fecal coliforms and Enterococcus spp. were high in sediments and exceeded the regulatory standard for all water samples. In dry conditions, levels were lower in water samples, but still high in sediment samples. Significantly greater population diversity was observed in the rain event compared to the dry event for both E. coli and Enterococcus populations, and greater population similarity was vi observed in dry conditions. Enterococcus population diversity was significantly higher in untreated sewage and the Siesta Key rain event when compared to dry conditions, and to a site on the Myakka River (no known human input or urban stormwater runoff). Siesta Key populations in dry conditions were most similar to Myakka, and sewage was the least similar to all other populations. Increased population similarity for E. coli and Enterococcus spp. during dry conditions suggests that a portion of the population is composed of “survivor” isolates. Persistence of survivor isolates in the storm drainage system, where urban runoff can sit for days, suggests a reservoir for indicator bacteria that can be flushed through the system to the Gulf, causing high levels of indicator bacteria in receiving waters.

Abstract Accurate measurement of the hydroperiod in isolated wetlands currently relies upon the installation and frequent monitoring of devices such as piezometers and staff gauges. Observations of biological indicators of the hydroperiod may be able to supplement data collected from these devices and could potentially replace them as a means of accurately determining this hydrologic interval. The study objective was to determine whether adventitious root formation and maturation on buttonbush (Cephalanthus occidentalis) could be used as a viable indicator of the hydroperiod in isolated wetlands. Buttonbush seedlings were flooded in a controlled environment over a three month period in the summer of 2011. During this time, the length and complexity of adventitious roots observed were recorded. When average lengths of primary roots were regressed against time of inundation, a linear regression (r2) of 0.94 was calculated. The structure of these roots was then compared to adventitious roots observed in a natural wetland with a hydroperiod of 12 months. This was undertaken to allow a comparison of the observed lengths and complexity of adventitious roots in the controlled experiment with roots in the natural environment. The regression of both sets of observations yielded an r2 value of 0.99. Consequently, the results of this study found that the length of adventitious roots on buttonbush can help determine the hydroperiods of isolated wetland systems.

Asymmetric synthesis has become an important tool to prepare enantiomerically pure compounds because it avoids the wasteful discarding of the undesired enantiomer. Combinatorial libraries allow for much faster screening for new and better asymmetric catalysts/auxiliaries, but they generate a large number of samples whose enantiomeric excess (ee) cannot be determined rapidly. This bottleneck currently limits the applicability of such approaches. We propose here the use of faster optical techniques for the determination of ee using common instrumentation, such as UV-vis spectrophotometers, and circular dichroism (CD) spectrophotometers. Our methods are easily transitioned to the microwell format commonly used in parallel/combinatorial chemistry endeavors, just by using common microplate readers: this allows for an even more rapid analysis of samples and a seamless integration in a high-throughput workflow. We have shown that enantioselective indicator displacement assays can be developed to determine ee in a high-throughput fashion utilizing either a UV-vis spectrophotometer or a 96-well plate reader. Two chiral receptors and a commercial pH indicator were used to enantioselectively discriminate α-amino acids by monitoring the degree of indicator displacement. The two receptors were able to enantioselectively discriminate 13 of the 17 analyzed α-amino acids and accurately determine ee values of independent test samples with the use of ee calibration curves. Moreover, a sample of valine was synthesized through an asymmetric reaction, whose ee was then determined with our assay and compared to chiral HPLC and 1H NMR chiral shift reagent analysis, with excellent correlation. An artificial neural network was also successfully employed in the analyses, as an alternative to ee calibration curves. Both techniques consistently produced results accurate enough for preliminary determination of ee in a rapid manner, allowing for high throughput screening (HTS) of asymmetric reactions. The use of circular dichroism spectroscopy with chiral BINAP was also explored to enantioselectively discriminate α-chiral ketones. The ketones were derivatized with pyridyl hydrazines to produce hydrazones, which were then bound to enantiomerically pure [Cu(I)(BINAP)]+, forming diastereomeric complexes with differential steric interactions leading to different degrees of twist in the BINAP moiety and characteristic signatures in the CD spectrum, as a function of sample ee. / text

Determining the presence of an analyte of interest, and finding the enantiomeric purity of chiral molecules are challenging tasks. This work in molecular recognition is carried out routinely by many different researchers, including both academic as well as industrial research groups. The following dissertation presents original research directed toward two different areas of interest to the molecular recognition community: enantioselective sensing in solution, and sensing at a defined interfacial environment. This work begins with a review of the non-chromatographic ways that the enantiomeric purity of chiral carboxylic acids is determined, presented in Chapter 1. Carboxylic acids are important functional groups, both for organic synthesis as well as pharmaceutical drug development. Chapter 2 presents efforts that have been made to rapidly assess both the enantiomeric purity and identity of chiral carboxylic acids, utilizing the technique of exciton-coupled circular dichroism (ECCD). A twist is imparted on a complex, and can be correlated with the absolute configuration of the stereocenter. The enantiomeric composition can be rapidly determined. After creating the assay, the focus of the work shifted toward applying this system to new classes of analytes. Chapter 3 covers chemo- and enantioselective differentiation of [mathematical symbol]-amino acids, and continues to discuss the expansion to [mathematical symbol]-homoamino acids. Then a synthetic substrates was tested, and a series of reactions screened to determine if any enantioselectivity had been imparted by a Baeyer-Villiger oxidation. Finally, the enantiomeric composition of a biaryl atropisomer, a compound lacking a stereocenter, was determined. The signal produced from this assay is at a relatively short wavelength, and efforts were undertaken to push this signal to longer wavelength. Chapter 4 is a compendium of the lessons that were learned upon attempting to create a self-assembled sensing system. The final chapter details work that was done in collaboration with Professor Katsuhiko Ariga at the National Institute of Materials Science in Tsukuba, Japan. In this chapter, an indicator displacement assay was carried out for the first time at the air-water interface. This contribution opens the door for sensing to be carried out at defined regions, rather than free in bulk solution. / text

The purpose of this study was to investigate whether progress indicators' various degrees of feedback have any impact on the users' subjective experienced time and satisfaction during loading sequences in smartphones. By executing a user test 30 participants used and evaluated three mobile applications, containing unique stimuli in the form of progress indicators. Throughout this we have been informed of the participants self-reflection experience through subsequent interviews. The result of this shows a clear correlation between progress indicators' degree of feedback and their impact on the subjective experienced time, and the degree of satisfaction. We made interesting findings in terms of the fastest perceived loading sequence was not alwaysthe most satisfying, but we can only discuss the reason behind this since further researchis required. Finally, we conclude that the development of applications should make useof progress indicators with a high degree of feedback since they positively promotes the subjective experienced time and satisfaction. Because of studies with this focus in UXare infrequent, we assume that this study can form the basis for further and deeper research in the subject. / Syftet med denna studie var att undersöka om laddningsindikatorers olika grad av återkoppling har någon inverkan på användares subjektiva tidsuppfattning och tillfredsställelse vid laddningssekvenser i smartphones. Genom att i ett användartest låta 30 deltagare använda och utvärdera tre mobilapplikationer, försedda med unika stimuli i form av laddningsindikatorer, har vi fått ta del av deltagarnas självreflektiva upplevelse genom efterföljande intervjuer. Resultatet av detta visar på ett tydligt samband mellan laddningsindikatorers grad av återkoppling och dess påverkan på den subjektiva tidsuppfattningen, samt graden av tillfredsställelse. Vi gjorde intressanta fynd i form av att den snabbast upplevda laddningssekvensen inte alltid var den mest tillfredsställande, men orsaken kan vi endast diskutera kring då vidare forskning krävs. Slutligen drar vi slutsatsen att man vid utveckling av applikationer bör använda sig av laddningsindikatorer med hög grad av återkoppling, då de positivt främjar den subjektiva tidsuppfattningen samt tillfredsställelsen. Då forskning med detta fokus inom UX är sällan förekommande ser vi att denna studie kan ligga till grund för vidare och djupare forskning inom ämnet.

The research project, Optimization of an array of Peptidic Indicator Displacement Assays for the Discrimination of Cabernet Sauvignon Wines, describes the multiple step lab trials conducted to optimize an array of ensembles composed of synthesized peptides and PCV:Cu+2 complexes for the differentiation of seven Cabernet Sauvignon wines with different tannin levels. This report also includes the methods and analysis used. The analysis interpreted by principal component analysis. / text