Management of greater sage-grouse (Centrocercus urophasianus) in the west has changed over the last several decades in response to environmental and anthropogenic causes. Many land and wildlife management agencies have begun manipulating sagebrush with herbicides, machinery, and fire. The intent of these manipulations (treatments) is to reduce sagebrush canopy cover and increase the density of grass and forb species, thus providing higher quality sage-grouse brood-rearing habitat. However, monitoring of sage-grouse response to such manipulations has often been lacking or non-existent. The objective of our study was to determine the response of sage-grouse to sagebrush reduction treatments that have occurred recently in Rich County, Utah. Our study areas were treated with a pasture aerator with the intent of creating sage-grouse brood-rearing habitat. We used pellet transects, occupancy sampling, and GPS radio telemetry to quantify sage-grouse habitat use in treated and untreated areas. Pellet transect, occupancy, and GPS radio telemetry methods all showed a strong pattern of sage-grouse use of treated sites during the breeding and early brood-rearing periods. Sage-grouse use of treated sites was greatest in lower elevation habitat (1950 to 2110 m), and use was highest during the breeding and early brood-rearing periods. We found very little use of higher elevation (2120 to 2250 m) treated or untreated sites. Our results suggest that sagebrush reduction treatments can have positive impacts on sage-grouse use at lower elevations and can be successful in creating brood-rearing habitat. Elevation differences and period of sage-grouse use were significant factors in our study in determining how beneficial sagebrush reduction treatments were for sage-grouse.

Le contrôle de la production des particules de suies est aujourd'hui un enjeu industriel majeur en raison de leur impact néfaste tant sur le climat que sur la santé humaine et de leur forte contribution aux transferts radiatifs. Pour mieux comprendre et contrôler la production de ces polluants dans les foyers industriels, il est primordial d’améliorer nos connaissances à ce sujet dans un brûleur turbulent. L’objectif de cette thèse est donc de mettre en place des diagnostics optiques pour l’étude des flammes suitées turbulentes et pour caractérise la production de suies dans une nouvelle configuration de combustion prémélangée,confinée, swirlée turbulente académique tout en se rapprochant des configurations industrielles. Une première configuration expérimentale laminaire est donc considérée afin de valider la mise en place de la technique d’Incandescence Induite par Laser (LII) pour mesurer la fraction volumique de suies fv. Il s’agit d’un brûleur conçu à l’université de Yale qui permet la stabilisation d’une flamme laminaire de diffusion éthylène/air. Ce brûleur a été largement étudié dans la littérature nous permettant ainsi de comparer nos mesures aux résultats de différentes équipes internationales. La calibration du signal LII avec la technique MAE (Modulated Absorption Emission) a été effectuée via une collaboration avec l’UPMC, permettant de mesurer quantitativement fv et de comparer les techniques MAE et LII. Le brûleur a ensuite été équipé d’un haut-parleur afin de moduler l’écoulement et de pouvoir étudier les effets d’une perturbation contrôlée sur la production de suies, se rapprochant ainsi des phénomènes instationnaires caractéristiques des écoulements turbulents. Enfin, les effets d’élargissement de la nappe laser sur les résultats de la LII sont examinés afin de pouvoir appliquer ce diagnostic optique dans une configuration turbulente innovante caractérisée par de grandes dimensions. Ce brûleur (EM2Soot) a été développé pour mesurer la production de suies dans une flamme turbulente swirlée riche confinée prémélangée. Il permet de quantifier indépendamment les effets de la richesse, de la puissance et de l’environnement thermique sur la production de suies. Un point de fonctionnement représentatif a alors été étudié et, en parallèle avec la LII, les techniques de vélocimétrie par images de particules (PIV), et de mesure de température des parois par phosphorescence induite par laser (LIP) ont été employées afin de caractériser l’effet de la turbulence sur la production des suies et d’établir une base de données pour la validation de futures simulations numériques. Enfin, la géométrie du brûleur a été modifiée permettant une stabilisation différente de la flamme (en forme d’un V). Un nouveau point de fonctionnement a alors été étudié afin de mettre en évidence le rôle de la géométrie de l’injecteur sur la stabilisation de la flamme et, par conséquent, la production totale de suies. / The control of soot particles production represents today a major industrial issue because of their harmful impact on both the climate and the human health and their strong contribution to the radiative transfers. To better understand and control the production of these polluting emissions, it is essential to improve our knowledge on this subject in a turbulent burner. The objective of this Ph.D. is to set up optical diagnostics for the study of turbulent flames and to experimentally characterize soot production in a new academic turbulent premixed combustion configuration while approaching industrial configurations, generally confined and swirled flows. For this, a laminar experimental configuration is first considered to validate the implementation of the Laser Induced Incandescence (LII) technique to measure the soot volume fraction fv. This burner designed at Yale University allows the stabilization of a laminar ethylene/air diffusion flame. This burner has been widely studied in the literature, so that it is possible to compare the quality of our measurements with the results of different international teams. Through collaborations with the UPMC, we calibrated the LII signal with the MAE (Modulated Absorption Emission) technique, making it possible to quantitatively measure fv and to compare the MAE and LII techniques. Finally, the burner was equipped with a loudspeaker to modulate the flow and to study the effects of a controlled perturbation on the soot production, thus approaching the unsteady phenomena characteristics of turbulent flows. Finally, the effects of the enlargement of the laser sheet on LII results were also investigated in order to be able to apply this diagnostic technique in an innovative large turbulent configuration. This experimental configuration, called EM2Soot, was developed to measure the production of soot in a turbulent swirled rich confined premixed ethylene/air flame. This burner makes it possible to independently quantify the effects of the equivalence ratio, the total flame power and the thermal environment on the total soot production. A representative operating point was then characterized, in parallel with LII measurements, Particle Image Velocimetry (PIV) and Laser Induced Phosphorescence (LIP) techniques have been employed in order to characterize the effect of the turbulence on soot production and to establish a database for the validation of future numerical simulations. Finally, the geometry of the burner has been modified allowing a different stabilization of the flame (V flame shape). A new operating point is then studied in order to highlight the role of the injector geometry on the stabilization of the flame and, consequently, on the total soot production.

No description available.

Indiana University-Purdue University Indianapolis (IUPUI) / Mutations in the gene encoding for leucine rich repeats kinase 2 (LRRK2) are commonly found in Parkinson’s disease. Recently, we found that the disease-associated point mutations at residue R1441 in the G domain (ROC) of LRRK2 resulted in perturbation of its GTPase activity. In this study, we compare the biochemical and biophysical properties of the ROC domain of LRRK2 carrying the PD-associated mutations at residue R1441 with those of the wild-type. We found that the disease-associated mutations (R1441C/G/H) showed marked quaternary structure compared to wild-type, in that the latter existed in solution in both monomeric and dimeric conformations dynamically regulated by GDP/GTP binding state, while we detected only monomeric conformation for three disease-associated mutants. To understand the structural basis for this plasticity and the activity reduction in the mutants, we solved a 1.6 Å crystal structure of the wild type ROC that shows a stable dimeric conformation in which the switch motifs and inter-switch regions mediate extensive interactions at the dimer interface. Residue R1441, where PD-associated mutations occur, forms exquisite interactions at the interface, thus suggesting a critical role of this residue in maintaining a dynamic dimer-monomer interconversion and conformational flexibility of the switch motifs. Consistently, substituting R1441 for other arbitrary mutations (R1441K/S/T) lead to similar perturbation of GTPase activity and dimerization defects as observed in the disease-associated mutants. Locking the ROC domain in either dimeric or monomeric conformations by engineered disulfide bond alters the binding affinity to GTP (but not GDP) and significantly reduce GTPase activity, thus suggesting that the dynamic dimer-monomer interconversion and conformational plasticity are essential for ROC function as a molecular switch modulating the kinase activity of LRRK2.

Spiders are capable of producing a variety of silk types, each with their own unique protein composition and function. Dragline silk in particular, has been of great interest due to its high tensile strength and extensibility. In the past, synthetically produced dragline fibers have not been able to match the superior properties of natural silk. A recent discovery in the western black widow spider, Latrodectus hesperus, might be the missing link between the current state of synthetic silks and naturally produced fibers. Our research is centered around the discovery a new family of five low-molecular-weight cysteine-rich proteins (CRPs) and their potential function within dragline silk. This study focuses on the characterization of recombinantly expressed CRP1, CRP2, and CRP4. Through structural analysis using circular dichroism, it has been determined that the CRP family members have mostly alpha-helical secondary structure and exhibit small differences in their ability to maintain their structure in the presence of changing environmental conditions. The study also covers the effects of temperature and pH on the folding and unfolding of the CRPs. It appears that pH is the dominant influence on protein unfolding within the major ampullate gland.

Spiders spin a wide variety of different silk types with different biological functions that are known for their extraordinary mechanical properties. Dragline silk has predominantly captured the interest of researchers because it exhibits high tensile strength and toughness while maintaining its elasticity. This thesis has focused on the characterization of a family of small molecular weight proteins recently discovered in dragline silk. These proteins were discovered in the western black widow spider, Latrodectus hesperus, and have been termed Cysteine-Rich Proteins (CRPs) due to their high conserved cysteine content. CRP family members were used in protein-protein interaction studies to determine if there is any interaction with the major ampullate spidroins (MaSps). After affinity chromatography and co-expression studies in bacteria, there were no detectable interactions between the CRPs and MaSp1. Further studies which could be an important role in the natural silk assembly process. Further protein interaction studies in different salt and pH conditions can further determine the function of the CRPs in dragline silk formation.

京都大学 / 0048 / 新制・課程博士 / 博士(理学) / 甲第18068号 / 理博第3946号 / 新制||理||1568(附属図書館) / 30926 / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)准教授 延與 佳子, 教授 畑 浩之, 准教授 板垣 直之 / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DGAM

京都大学 / 0048 / 新制・課程博士 / 博士(エネルギー科学) / 甲第19093号 / エネ博第317号 / 新制||エネ||64(附属図書館) / 32044 / 京都大学大学院エネルギー科学研究科エネルギー変換科学専攻 / (主査)教授 木村 晃彦, 教授 星出 敏彦, 教授 今谷 勝次 / 学位規則第4条第1項該当 / Doctor of Energy Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・論文博士 / 博士(農学) / 乙第13055号 / 論農博第2839号 / 新制||農||1045(附属図書館) / 学位論文||H28||N5012(農学部図書室) / 33145 / (主査)教授 河田 照雄, 教授 保川 清, 教授 橋本 渉 / 学位規則第4条第2項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

京都大学 / 0048 / 新制・課程博士 / 博士(薬科学) / 甲第20299号 / 薬科博第68号 / 新制||薬科||8(附属図書館) / 京都大学大学院薬学研究科薬科学専攻 / (主査)教授 松﨑 勝巳, 教授 加藤 博章, 教授 石濱 泰 / 学位規則第4条第1項該当 / Doctor of Pharmaceutical Sciences / Kyoto University / DGAM