Sweet clover has become increasingly important as a forage and green manure crop. The main objection in recent years to sweet clover is its coumarin content, identified by a sweet odor and bitter taste, making it less desirable to farm animals. When sweet clover hay spoils, the coumarin is converted into dicoumarol which is toxic to animals, especially to ruminants. When ingested this may cause internal and/or external hemorrhages.

Bacteriophage infection of Streptococcus thermophilus is a growing concern in the mozzarella cheese industry. One method to control this problem may be to replace S. thermophilus with a starter coccus from a different genus of lactic acid bacteria. This work evaluated the possibility of using genetically modified Pediococcus spp. for this approach. Electroporation was used to introduce genes for lactose utilization from Lactococcus lactis into strains of P. acidilactici and P. pentosaceus. The resulting lactose-positive transformants, P. acidilactici SAL and P. pentosaceus SPL-2, rapidly reduced the pH of lactose broth, accumulated [14C]lactose at a rate higher than a lactococcal control, and showed relatively high phospho-β-galactosidase activity. When paired with Lactobacillus helveticus LH100 in 9% reconstituted skim milk, P. acidilactici SAL and P. pentosaceus SPL-2 demonstrated synergistic growth with LH100. Milk fermented with Pediococcus-LH100 starter pairs also contained significantly less free galactose than milk fermented with a control starter blend of LH100 and S. thermophilus TA061. Mozzarella cheese made with lactose-positive Pediococcus-LH100 blends was compositionally similar to cheese made with the control starter blend, but production required 60-90 additional minutes. In an attempt to decrease the time required to produce mozzarella, Pediococcus spp. were transformed with lactococcal genes from an extracellular serine proteinase ora n oligopetpide transport system. Constructs which expressed each system were obtained, but these strains did not display improvement in the ability to clot 9% reconstituted skim milk.Studies to screen P. acidilactici and P. pentosaceus for lysogeny detected temperate bacteriophage in three strains of P. acidilactici. Morphological characterization of these new phages demonstrated that they had small isometric heads with non-contractile tails and thus belonged to the B I group of the family Siphovirdae. Further characterization based on DNA-DNA homology and protein profiles suggested that the P. acidilactici phages can be separated into at least two different species. As a whole, the results reported here suggest that due to their slower growth in milk, P. acidilactici SAL and P. pentosaceus SPL-2 cannot be used as direct replacements for S. thermophilus but may be suited for use as adjuncts to the traditional S. thermophilus/Lactobacillus sp. starter blend.

Bees are necessary pollinators for a vast array of different plants, including many which we rely on for food. In order to grow sufficient crops to feed the world’s growing population, we need to make sure our crops are visited by the most effective possible pollinators. However, this is complicated by the fact that there are over 4,000 bee species in North America, many of which vary in their pollination effectiveness and are difficult to identify. My dissertation’s first two data chapters focus on classifying the species of the xeric solitary bee group Anthophora subgenus Micranthophora, including seven newly described species, while also providing identification resources for telling them apart. With this group’s classification fixed, my third chapter then uses differences in the DNA of these species to reconstruct evolutionary trees of their relationships; those with more similar DNA sequences are grouped more closely together. I then use powerful modern methods to and determine how quickly new species have arisen throughout the entirety of the group’s evolutionary history, in order to determine how desertification has influenced the evolution of these xeric bees. My results suggest that the Neogene Uplift, a mountain-building event, initially increases their diversification rates, but climatic cooling and niche competition later greatly decrease these rates. Finally, my last chapter looks at bee evolution from a contemporary perspective, viewed through the lens of a new species of bee that actually excavates its nests in sandstone, Anthophora pueblo, despite the obvious time and energy costs of this behavior. In addition to describing this fascinating new species, I also use interdisciplinary methods from biology and geology to demonstrate that, although they prefer to use weaker sandstone, intermediate levels of sandstone hardness are likely beneficial to them, enabling future generations of their relatives to reuse nest tunnels for many years without excavating. Preliminary evidence also suggests that these bees benefit from protections afforded to them against parasites and pathogens that can destroy their nests and kill their offspring. Overall, this species will provide a terrific system for future studies of bee evolution and life history trade-offs. By performing these studies, my dissertation will enable a wealth of additional studies on these poorly known solitary bees.

Indiana University-Purdue University Indianapolis (IUPUI) / The reaction between elemental sulfur and sulfide is a lynchpin in the biotic and abiotic cycling of sulfur. This dissertation is focused on the reactivity of elemental sulfur nanoparticles (S8weimarn, S8raffo) among other forms of elemental sulfur (S8aq, S8aq-surfactant, α-S8), and how the variation of their surface area, character and coatings reflect on the analytical, physical-chemical and geochemical processes involving sulfur cycling. A comprehensive electrochemical investigation utilizing mercury-surface electrodes showed that elemental sulfur compounds are represented by three main voltammetric signals, corresponding to potentials at -1.2V, -0.8V, and -0.6V in the absence of organics at circumneutral pH. Dissolved S8aq-surfactant signals can be found from -0.3V up to -1.0V, depending on the surfactant in the system. Variations in current response resulted from differences in electron transfer efficiency among the forms of S8, due to their molecular structural variability. Based on this observation a new reaction pathway between S8 and Hg-surface electrodes is proposed, involving an amalgam-forming intermediate step. The kinetics of the nucleophilic dissolution of S8nano by sulfide, forming polysulfides, were investigated under varying surface area, surface character and presence or absence of surfactant coatings on S8nano. Hydrophobic S8weimarn and hydrophilic S8raffo show kinetic rate laws of 𝑟𝑆8𝑤𝑒𝑖𝑚𝑎𝑟𝑛 = 10−11.33 (𝑒 −700.65 𝑅𝑇 ) (Molar(S8)/second/dm-1) and𝑟𝑆8𝑟𝑎𝑓𝑓𝑜 = 10−4.11 𝑖−0.35 (𝑒 −615.77 𝑅𝑇 ) (Molar(S8)/second), respectively. The presence of surfactant molecules can influence the reaction pathways by dissolving S8nano and releasing S8aqsurfactant, evolving the rate-limiting step as a function of the degree of the solubilization of S8nano. The reaction rate of S8biological can be compared with those of S8raffo and S8weimarn in circumneutral pH values and T=50oC, making the forms of S8nano successful abiotic analogue models of microbially produced S8biological. Field observations and geochemical kinetic modeling in the geothermal features of Yellowstone indicate that the nucleophilic dissolution reaction appears to be a key abiotic pathway for the cycling of sulfur species and the enhancement of elemental sulfur bioavailability. Furthermore, in situ and ex situ voltammetry in the same geothermal waters disclosed chaotic variability in chemical gradients of sulfide (observed over small temporal and spatial scales) which can be considered as an ecological stressor capable of influencing single cell physiology and microbial community adaptation.

No description available.

In 1999, a new species of minnow, Chrosomus sp. cf. saylori (Clinch dace), was discovered in the Tennessee drainage of Virginia. Chrosomus sp. cf. saylori are listed as a Federal Species of Concern and on Virginia\'s Wildlife Action Plan as Tier II- Very High Conservation Need because of potential threats from habitat degradation, high population fragmentation, and a largely unknown distribution. Consequently, a management plan for C. sp. cf. saylori is of utmost importance, but more information regarding its distribution and life history is required before such a plan can be implemented. In 2011 and 2012 I sampled 60 headwater streams in the upper Clinch River watershed, Virginia.  From this and historical data, I conclude that C. sp. cf. saylori are restricted to eight small tributaries to the Clinch River.  Multivariate analysis of habitat correlates indicated that C. sp. cf. saylori populations are found in small, high elevation streams with gravel substrate and forested watersheds.  Three species distribution models were unable to predict C. sp. cf. saylori distribution.  Morphological traits were significantly different between C. sp. cf. saylori and other Chrosomus, thereby providing an initial indication of speciation and differing niche roles. I observed a nest association with Campostoma anomalum.  Gonad weight was lower for C. sp. cf. saylori than closely-related congeners. Together, this information indicates that C. sp. cf. saylori are narrowly distributed and populations are small, fragmented, and of questionable viability.  In the future, long-term monitoring efforts and genetics analyses should be completed and additional protection measures pursued. / Master of Science

京都大学 / 0048 / 新制・論文博士 / 博士(医学) / 乙第12816号 / 論医博第2078号 / 新制||医||1004(附属図書館) / 31303 / 京都大学大学院医学研究科医学専攻 / (主査)教授 岩井 一宏, 教授 長田 重一, 教授 川口 義弥 / 学位規則第4条第2項該当 / Doctor of Medical Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(人間・環境学) / 甲第18358号 / 人博第671号 / 新制||人||161(附属図書館) / 25||人博||671(吉田南総合図書館) / 31216 / 京都大学大学院人間・環境学研究科相関環境学専攻 / (主査)教授 松井 正文, 教授 加藤 眞, 教授 市岡 孝朗 / 学位規則第4条第1項該当 / Doctor of Human and Environmental Studies / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第18851号 / 医博第3962号 / 新制||医||1007(附属図書館) / 31802 / 京都大学大学院医学研究科医学専攻 / (主査)教授 別所 和久, 教授 鈴木 茂彦, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第19532号 / 理博第4192号 / 新制||理||1602(附属図書館) / 32568 / 京都大学大学院理学研究科生物科学専攻 / (主査)准教授 渡辺 勝敏, 教授 疋田 努, 教授 曽田 貞滋 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM