The genetic variation at the diallelic mitochondrial malic enzyme (<I>MEP-2*</I>) locus represents one of the most widespread polymorphisms detected in the Atlantic salmon (<I>Salmo salar </I>L.). Previous studies of this locus in wild fish populations have found evidence to suggest an adaptive genetic response to local environmental temperature. In both Europe and North America, latitudinal clines in the frequencies of the two <I>MEP-2*</I> alleles exist, that show the same correlation with environmental temperature. In addition, these studies have identified variable associations between <I>MEP-2*</I> genotypes and phenotypic variation in juvenile growth in freshwater. Because growth performance is known to influence survival and reproductive success in Atlantic salmon, it has been postulated that differences in <I>MEP-2*</I> genotype growth performance could be a factor underlying the basis of this apparent adaptive response. This thesis investigates the relationship between <I>MEP-2*</I> genotype, temperature and growth performance in juvenile Atlantic salmon. The thesis aims were (i) to determine whether the genetic variation at the <I>MEP-2*</I> locus in the Atlantic salmon was associated with differences in juvenile growth performance in freshwater, (ii) when any such differences were established, and (iii) to what extent water temperature influenced the association. These were achieved by monitoring <I>MEP-2*</I> genotype growth performance and survival in juvenile Atlantic salmon, hatchery reared under warm (ambient plus <I>ca.</I>4°C), ambient (seasonally variable ambient water temperature) and cold (ambient minus <I>ca. </I>4°C) water temperature regimens. The results obtained in this study clearly demonstrate that the genetic variation at the <I>MEP-2*</I> locus in the Atlantic salmon is associated with significant differences in juvenile growth performance in freshwater. Associations were observed both early in post-hatch development, and later when the fish had made the transition to exogenous feeding. Furthermore, these associations were found to be strongly influenced by both temperature and feeding ration. These are specific new findings which significantly add to our present knowledge of the <I>MEP-2*</I> polymorphism in the Atlantic salmon. Although these associations did not influence survival in the study, it is postulated that if the same effect were to occur in natural populations, the genetic response indicated could influence fitness. Additionally, it is possible that these genotypic differences in growth performance could be of relevance to selective breeding programs within the salmon farming industry. However, whether the genetic response exhibited was directly due to the <I>MEP-2</I>* locus on its own, or to some other linked locus or loci, remains to be demonstrated.

Low streamflows and warm stream temperatures, caused mainly from agricultural diversions, currently limit available habitat and productivity of trout, including native Lahontan cutthroat trout in Nevada’s Walker River Basin. Environmental water purchases, which transfer water from willing sellers to instream uses (i.e for fish), are being evaluated to improve instream habitat. To determine which environmental water purchases to prioritize, this study was undertaken to build a computer model in order to simulate stream temperatures under differing environmental water transfer scenarios. Model runs simulate a range of environmental water transfers at major diversions and reservoirs throughout the Walker River Basin. Results indicate that low flows generally coincide with critically warm stream temperatures, cooler stream temperatures exist in the East Walker River, a tributary of the Walker River, during warm seasons which provide good habitat for fish, environmental transfers can improve stream temperatures for some highly impacted reaches by up to 3°C in dry years, and environmental water transfers have a greater effect in dry years than wet years.

京都大学 / 0048 / 新制・課程博士 / 博士(工学) / 甲第20353号 / 工博第4290号 / 新制||工||1664(附属図書館) / 京都大学大学院工学研究科都市環境工学専攻 / (主査)教授 米田 稔, 教授 伊藤 禎彦, 准教授 松井 康人 / 学位規則第4条第1項該当 / Doctor of Philosophy (Engineering) / Kyoto University / DFAM

No description available.

This thesis describes the development of liquid chromatography tandem mass spectrometry (LC-MS/MS) methods for the trace analysis of active pharmaceutical ingredients (APIs) and their metabolites in aqueous environmental matrices. The research was focused on the development of chiral LC-MS/MS methods for the analysis of fluoxetine and metoprolol, as well as their chiral metabolites in environmental water samples. A method was also developed for the achiral compounds, diazepam and nordiazepam. The LC-MS/MS methods were validated by the use of the isotope-labeled compounds. As these isotope-labeled compounds were not found in the wastewater samples, the validation could be assessed at trace level concentrations in the actual matrices in which the analytes were detected. The analytes were extracted from the water samples using solid phase extraction methods. Different types of solid phase extraction sorbents were evaluated. Fluoxetine and norfluoxetine were extracted through the use of a mixed mode polymeric based extraction sorbent. A hydrophilic and lipophilic balanced sorbent was employed for the simultaneous extraction of metoprolol and its metabolites, the base α-hydroxymetoprolol and the acidic metabolite deaminated metoprolol. Moreover, silica based C18 extraction discs were applied for the sample preparation of diazepam and nordiazepam. The chromatographic separations were conducted in reversed phase LC with MS compatible mobile phases. The enantiomers of fluoxetine and norfluoxetine were simultaneously separated using the chiral stationary phase (CSP), α1-acid glycoprotein (AGP). The Chiral AGP column was also applied for the separation of the enantiomers of deaminated metoprolol. For the simultaneous separation of the metoprolol enantiomers and the four stereoisomers of α-hydroxymetoprolol, the cellobiohydrolase (CBH) protein based CSP was used. An octadecyl silica based LC column was applied for the separation of diazepam and nordiazepam. The analytes were detected by the use of tandem quadrupole mass spectrometry operating in selective reactive monitoring mode. High resolution MS, employing a quadrupole time-of-flight (QqTOF) mass analyzer, was utilized for the identification of an unknown compound in wastewater samples. The APIs and their metabolites, as well as their respective enantiomers, were quantified in raw and treated wastewater from Uppsala, Sweden along with surface water from the River Fyris in Uppsala.

Human impacts from land and water development have degraded water quality and altered the physical, chemical, and biological integrity of Nevada's Walker River. Reduced instream flows and increased nutrient concentrations affect native fish populations through warm daily stream temperatures and low nightly dissolved oxygen concentrations. Environmental water purchases are being considered to maintain instream flows, improve water quality, and enhance habitat for native fish species, such as Lahontan cutthroat trout. This study uses the River Modeling System (RMSv4), an hourly, physically-based hydrodynamic and water quality model, to estimate streamflows, temperatures, and dissolved oxygen concentrations in the Walker River. Stream temperature and dissolved oxygen changes were simulated from potential environmental water purchases to prioritize the time periods and locations that water purchases most enhance stream temperatures and dissolved oxygen concentrations for aquatic habitat. Environmental water purchases ranged from 0.03 cms to 1.41 cms average daily increases. Modeling results indicate that increased water purchases generally affect dissolved oxygen in two ways. First, environmental water purchases increase the thermal mass of the river, cooling daily stream temperatures and warming nightly temperatures. This prevents conditions that cause the lowest nightly dissolved oxygen concentrations (moderate production impairment thresholds are

Several studies indicates China is experiencing a water crisis, were several regions are suffering of severe water scarcity and rivers are heavily polluted. On the other hand, water is used inefficiently and wastefully: water use efficiency in the agriculture sector is only 40% and within industry, only 40% of the industrial wastewater is recycled. However, based on statistical data, China’s total water resources is ranked sixth in the world, based on its water resources and yet, Yellow River and Hai River dries up in its estuary every year. In some regions, the water situation is exacerbated by the fact that rivers’ water is heavily polluted with a large amount of untreated wastewater, discharged into the rivers and deteriorating the water quality. Several regions’ groundwater is overexploited due to human activities demand, which is not met by local. Some provinces have over withdrawn groundwater, which has caused ground subsidence and increased soil salinity. So what is the situation in China? Is there a water crisis, and if so, what are the causes?This report is a review of several global water scarcity assessment methods and summarizes the findings of the results of China’s water resources to get a better understanding about the water situation. All of the methods indicated that water scarcity is mainly concentrated to north China due to rapid growth, overexploitation from rivers and reduced precipitation. Whereas, South China is indicated as abundant in water resources, however, parts of the region are experiencing water scarcity due to massive dam constructions for water storage and power production. Too many dam constructions in a river disrupts flow of the river water and pollutants are then accumulated within floodgates.Many Chinese officials and scholars believe that with economic growth comes improved environmental quality when the economy has reached to a certain of per-capita level. However, with the present water situation it is not sustainable or possible for China to keep consuming and polluting its water resources. Improvement of environmental quality does not come automatically with increased income, and policies, laws and regulations are needed in order to stop further deterioration of the environment.China’s water situation is not any news and the key factor is human activities, but the question is how to solve it. China’s water crisis is much more complex than over exploitation of groundwater and surface water. There are three water issues in China: “too much water – floods, too little water – droughts, and too dirty water – water pollution” (Jun &amp; Chen, 2001). Thus, solving China’s water crisis is a huge challenge to solve without negatively affecting the economic growth.