Disinfectants, such as chlorine, are widely used in water treatment plants to ensure the safety and quality of drinking water. However, these disinfectants easily react with some natural or man-made organic compounds in raw water and then form disinfection by-products (DBPs). For example, halogenated acetic acid (HAAs) and trihalomethanes (THMs) are two main components of DBPs. The purposes of this study are to analyze the concentration of DBPs including HAAs and THMs in drinking water and investigate the distribution of DBPs in the processes of three advanced water treatment plants in southern Taiwan. The analytical method of HAAs is based on the USEPA Method 552.3 and THMs is analyzed by headspace solid-phase microextraction(HS-SPME). Moreover, some factors which may influence the formation of DBPs such as dissolved organic carbon (DOC) and water temperature are also analyzed to further discuss the relation to the generation of DBPs. Through this study, the results could be the reference for operation control in water treatment plants and regulation setting in Taiwan. The samples of drinking water were collected in three advanced water treatment plants in southern Taiwan from June 2007 to April 2008. The analyzed HAA9 results were 28.71 ¡Ó 14.77£g g / L in Plant A, 24.43 ¡Ó 15.70 £g g / L in Plant B, 28.91 ¡Ó 14.38 £g g / L in Plant C. Comparing the HAA5 results with the maximum contaminant level (MCL) in USEPA, it was clearly found that all the values were under the standard of 60 £g g / L. As to THMs, the results were 9.99 ¡Ó 3.39£g g / L in Plant A, 0.94 ¡Ó 2.12 £g g / L in Plant B, 28.91 ¡Ó 14.38 £g g / L in Plant C and greatly under the EPA standard of 80 £g g / L in Taiwan. Furthermore, the major species of HAA9 in order were BCAA and TCAA while THMs was trichloromethane (CHCl3). In the relation between DOC and DBPs, the results demonstrated that DOC was more relative to DBPs in raw water; meanwhile, the water temperature did not show great relation. In general, despite the poor correlation, it was still could conclude that the concentration of DBPs increases with the increase of DOC and temperature. In conclusion, the research results showed that the removal efficiency of DBPs in Plant A and B (UF/RO system) is greater than Plant C (Biological Activated Carbon system, BAC system ), and all three advanced water treatment plants could show greatly effectiveness in drinking water quality improvement. However, higher concentration of bromine products in HAAs was discovered in this research. It was suggested that the phenomenon should be further discussed and controlled.

<p>The important protein hormone insulin, responsible for different kind of functions in our body but mainly storage of nutrients, has for a long time been used for treatment of diabetic patients. This important protein is both physically and chemically unstable. Especially during production where the insulin protein is exposed to unnatural environmental conditions such as acidic pH has this been causing problems since huge volumes of the product go to waste.</p><p>In the human body the environment for the protein is tolerable with normal body temperature and the right pH, but when the protein is commercially synthesised the environmental conditions are not ultimate. What happens during these unfavourable conditions is that the insulin starts to fibrillate. Meaning that linear, biologically inactive aggregates are formed. If then under these kinds of conditions such as high temperature and acidic pH, the insulin comes in contact with hydrophobic surfaces then the fibrillation of the protein goes even faster.</p><p>In the following experiment I am going to investigate if the experiments and conclusions done before, where different kinds of additives to insulin solutions have been used to enhance the amyloid fibrillation of insulin, are as effective as it has been proposed and I am going to prove that the presence of hydrophobic surfaces, such as coated silicon surfaces or glass and addition of preformed fibrils, so called seeds, increase amyloid fibrillation of the insulin protein under certain conditions, in comparison with the normal fibrillation under the same conditions.</p>

Reproduction de : Thèse d'exercice : Médecine : Nancy 1 : 2005. / Titre provenant de l'écran-titre.

Reproduction de : Thèse d'exercice : Médecine générale : Nancy 1 : 2001. / Thèse : 01NAN11155. Titre provenant de l'écran-titre.

Thesis (D. Min.)--Dallas Theological Seminary, 2001. / Includes abstract. Includes bibliographical references (leaves 121-128).

A wide range of observed luminosities of young forming stars conflicts with predictions of the standard star formation model, which features a constant accretion rate. To resolve this discrepancy, an episodic accretion model has been suggested. The focus of this dissertation is to test this model in low mass star formation. I present new observations of the CB130 region. The observed photometric data from Spitzer and ground-based telescopes are used to determine the luminosity, and radiative transfer modeling of dust and gas are used to characterize the envelope and disk. I compare molecular line observations to models to constrain the chemical characteristics and abundance variations. Based on the chemical model result and molecular line observations, the low luminosity of the embedded protostar is explained better as a quiescent stage between episodic accretion bursts rather than as the first hydrostatic core stage. I present CO₂ ice observations toward 19 low luminosity embedded protostars. About half of the sources have evidence for pure CO₂ ice, and six have significant double-peaked features, which are strong evidence of pure CO₂ ice. The presence of detectable amounts of pure CO₂ ice signify a higher past luminosity, consistent with the past high accretion. Using chemical evolution modeling, the episodic accretion scenario, in which mixed CO-CO₂ ice is converted to pure CO₂ ice during each high luminosity phase, explains the presence of pure CO₂ ice, the total amount of CO₂ ice, and the observed residual C18O gas. I used CARMA to observe a sample of embedded protostars that spans the full range of protostellar luminosities, especially lower luminosity sources. The standard model predicts the disk mass increases steadily while the episodic accretion model predicts no clear relationship between disk mass and bolometric temperature. Masses of six detected disks spread out regardless of bolometric temperature. With the pure CO₂ ice detection, I can explain disk masses of the source in the context of episodic mass accretion. I conclude that episodic mass accretion provides a good explanation of the low luminosity of protostars, molecular line strength, pure CO₂ ice detection, total CO₂ ice amount and spread of disk masses. / text

The important protein hormone insulin, responsible for different kind of functions in our body but mainly storage of nutrients, has for a long time been used for treatment of diabetic patients. This important protein is both physically and chemically unstable. Especially during production where the insulin protein is exposed to unnatural environmental conditions such as acidic pH has this been causing problems since huge volumes of the product go to waste. In the human body the environment for the protein is tolerable with normal body temperature and the right pH, but when the protein is commercially synthesised the environmental conditions are not ultimate. What happens during these unfavourable conditions is that the insulin starts to fibrillate. Meaning that linear, biologically inactive aggregates are formed. If then under these kinds of conditions such as high temperature and acidic pH, the insulin comes in contact with hydrophobic surfaces then the fibrillation of the protein goes even faster. In the following experiment I am going to investigate if the experiments and conclusions done before, where different kinds of additives to insulin solutions have been used to enhance the amyloid fibrillation of insulin, are as effective as it has been proposed and I am going to prove that the presence of hydrophobic surfaces, such as coated silicon surfaces or glass and addition of preformed fibrils, so called seeds, increase amyloid fibrillation of the insulin protein under certain conditions, in comparison with the normal fibrillation under the same conditions.

Biofilms are formed in aquatic environments by the attachment of bacteria to submerged surfaces, to the air/liquid interface, and to each other. Although biofilms are associated with disease and biofouling, the robust nature of biofilms; for example, their ability to tolerate chemical and physical stresses, makes them attractive for beneficial biotechnology applications such as bioremediation and biofuels. Based on an understanding of diverse signals and regulatory networks during biofilm development, biofilms can be engineered for these applications by manipulating extracellular/intercellular signals and regulators. Here, we rewired the global regulator H-NS of Escherichia coli to control biofilm formation using random protein engineering. H-NS variant K57N was obtained that reduces biofilm formation 10-fold compared with wild-type H-NS (wild-type H-NS increases biofilm formation whereas H-NS K57N reduces it) via its interaction with the nucleoid-associated proteins Cnu and StpA. H-NS K57N leads to enhanced excision of the defective prophage Rac and results in cell lysis through the activation of a host killing toxin HokD. We also engineered another global regulator, Hha, which interacts with H-NS, to disperse biofilms. Hha variant Hha13D6 was obtained that causes nearly complete biofilm dispersal by increasing cell death by the activation of proteases. Bacterial quorum sensing (QS) systems are important components of a wide variety of engineered biological devices, since autoinducers are useful as input signals because they are small, diffuse freely in aqueous media, and are easily taken up by cells. To demonstrate that biofilms may be controlled for biotechnological applications such as biorefineries, we constructed a synthetic biofilm engineering circuit to manipulate biofilm formation. By using a population-driven QS switch based on the LasI/LasR system and biofilm dispersal proteins Hha13D6 and BdcAE50Q (disperses biofilms by titrating cyclic diguanylate), we displaced an existing biofilm and then removed the second biofilm. Persisters are a subpopulation of metabolically-dormant cells in biofilms that are resistant to antibiotics; hence, understanding persister cell formation is important for controlling bacterial infections. Here, we engineered toxin MqsR with greater toxicity and demonstrated that the more toxic MqsR increases persistence by decreasing the ability of the cell to respond to antibiotic stress through its RpoS-based regulation of acid resistance, multidrug resistance, and osmotic resistance systems.

Detailed study of strata associated with the glauconite-rich Floyds Knob Bed in the western Appalachian and eastern Illinois basins have corroborated previous interpretations that the unit is a widespread, largely synchronous marker horizon. However, in some areas there are multiple glauconite beds; in others a distinct bed is lacking, but the glauconite is dispersed throughout many beds, forming an interval rather than a distinct bed. In Kentucky and adjacent states, the Floyds Knob interval, in upper parts of the Lower-Middle Mississippian Borden-Grainger delta sequence and in lower parts of the Fort Payne carbonate sequence, was deposited at the end of loading-type relaxation during a flexural cycle in the Neoacadian (final) tectophase of the Acadian Orogeny. Tectonic influence, combined with a major late Osagean sea-level lowstand, created conditions that generated sediment starvation and shallower seas across widespread parts of the western Appalachian and eastern Illinois basins. In the absence of major sediment influx, glauconite was deposited uniformly across many major depositional settings, ranging from delta-platform to basinal environments. Especially important, however, is the newly reported occurrence of the Floyds Knob interval in basinal Fort Payne environments from south-central Kentucky, where it is represented by a thick, pelletal, glauconite-rich horizon that separates clastics at the base of the Fort. Payne Formation from carbonates at top. The study also provides the first-ever radiometric dating of the Floyds Knob glauconites, which suggests a late Osagean origin. These results support the existing biostratigraphic studies that point to a late Osagean origin for the Floyds Knob interval.

The bony fin rays of the zebrafish caudal fin are a convenient system for studying bone morphogenesis and patterning. Joints and bifurcations in fin rays follow predictable spatial patterns, though the mechanisms underlying these patterns are not well understood. We developed simulation models to explore ray pattern formation mechanisms in growing fins. In all models, the fin ray growth rates are based on quantitative experimental data. The different models simulate ray joint formation and bifurcation formation using different hypothetical mechanisms. In the most plausible model, ray joint and bifurcation formation result from the accumulation of two substances, arbitrarily named J and B. Model parameters were optimized to find the best fit between model output and quantitative experimental data on fin ray patterns. The model will be tested in the future by evaluating how well it can predict fin ray patterns in different fin shapes, mutant zebrafish fins, and other fish species.