Solid-liquid phase equilibria studies were used to investigate possible compound formation in solutions of (i) N,N-dimethylformamide (DMF) and (ii) N,N-dimethylacetamide (DMA) with a series of halogenated hydrocarbons that were selected to give a wide range of acceptor properties. Solid 1:1 intermolecular compounds were identified from solutions of (i) DMF and (ii) DMA with CCl_4, CBrCl_3, and C_6H_5CCl_3. The intermolecular compounds (DMF)_2•CCl_4 and (DMF)_2•CBrCl_3 were also found. The results suggest charge transfer from DMF or DMA to the chlorine atoms of the acceptor molecule as the process for compound formation. Thermal methods were used to determine with high precision the solid-liquid phase equilibria diagram for the sodium-cesium system. Results differ greatly from those of earlier workers, especially near the eutectic composition where differences in melting points as large as 35°K occur. Although not conclusive, results support the proposal that the peritectic halt results from the formation of an Na_2Cs intermetallic compound by a very sluggish reaction. Thermal methods were also used to determine the mesophase transition temperatures for cholesteryl formate.

京都大学 / 0048 / 新制・課程博士 / 博士(社会健康医学) / 甲第20624号 / 社医博第82号 / 社新制||医||9(附属図書館) / 京都大学大学院医学研究科社会健康医学系専攻 / (主査)教授 木原 正博, 教授 古川 壽亮, 教授 柳田 素子 / 学位規則第4条第1項該当 / Doctor of Public Health / Kyoto University / DFAM

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Background Long QT syndrome (LQTS) is characterized by a prolonged QT interval on the electrocardiogram (ECG), a risk for sudden cardiac death. A simple 'rule of thumb' method states that if a patient's heart rate is between 60-100 bpm, the QT interval should not be more than half the R-R interval. The clinical accuracy of this method has not been tested in the elderly. Objectives To determine if the 'rule of thumb' to calculate QT interval prolongation, is accurate, compared to the corrected QT interval calculated using Bazett's formula. Secondary objectives include the prevalence of long QT and risk factors for QT prolongation. Methods The QT interval was calculated using Bazett's formula, and the 'rule of thumb' method, from ECG's collected from patients over 60 years old, on their first visit to a geriatric clinical service. Only data from patients with heart rates in the range 60-100 were analyzed. Medications and electrolyte levels were recorded. Results A total of 1000 ECGs were collected. 776 ECGs were included in the study. Prevalence of prolonged QT interval was 37.8% using Bazett's formula. Compared to Bazett's formula, the 'rule of thumb' method had a sensitivity of 65.2% and a specificity of 96.9%. ECG computer analysis calculated QTc was available for 42.5% of the cases and had a sensitivity of 58.1% and specificity of 95.3% compared to Bazett's formula. Of the 23.3% of patients taking medications known to prolong the QT interval only 38.6% had a prolonged QT interval. There was a significant association between QT interval prolongation and hypokalaemia. Conclusion The 'rule of thumb' method to determine QT interval prolongation, has high specificity but low sensitivity. This bedside measure is similar in accuracy to QT determination using an ECG computer analysis calculation in this population of older persons. / MT 2019

Flood-control reservoirs experience water level fluctuations that control survival of their biota. I explored diverse but related aspects of water-level management. Three frameworks were indentified for directing rule curve (i.e., daily targets for water levels) changes in flood-control reservoirs managed by the U.S. Army Corps of Engineers (USACE), with differing scopes and requirements. Framework choice depends on the reservoir’s primary authorization and magnitude of the contemplated change. Changes without congressional approval must be based on flood risk. Quantile regression was used to model a maximum water level with a user-specified level of risk. Because actions that request changes to water levels from natural resource professionals should have a sound ecological basis, I analyzed the relationships between water level fluctuations and vegetation in reservoirs. Remote sensing methods were used to calculate a greenness index from vegetation in the reservoir based on 14 years of satellite imagery and water levels.

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Thesis advisor: Christopher Kenaley / Bergmann’s rule predicts a change in body size with latitude, with larger members of a taxonomic group occurring further from the equator. This pattern has been described for many groups of organisms; however, no study has assessed this relationship across a substantial number of ray-finned fish species, the largest group of vertebrates. I performed Bayesian phylogenetic modeling using maximum length and latitude data for 3021 species of actinopterygians to assess Bergmann’s rule in the group. The impact of salinity tolerance on the relationship between length and latitude was also considered. Maximum length and salinity tolerance data were obtained from FishBase, and latitude data were obtained from museum records. I found that, overall, Bergmann’s rule holds and is not significantly affected by salinity tolerance except when not considering phylogeny, in which case only marine species show the trend. / Thesis (BA) — Boston College, 2023. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Departmental Honors. / Discipline: Biology.

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