Hydrocracking is one of the most essential catalytic processes in the oil industry for the conversion of heavy fractions of petroleum (light and heavy vacuum gas oil, demetallized oil) and renewable hydrocarbon feedstocks to high-quality fuels. Hydrocracking relies on a bifunctional catalytic process that combines catalytic cracking and hydrogenation steps. In principle, hydrocracking is aimed to convert heavy and ultraheavy oils with maximum fuel selectivity and minimum formation of light gases and polyaromatic compounds, from this high activity and selectivity of the catalyst, is achieved by finding a good balance between its acidic and hydrogenation properties. For this study, platinum catalyst impregnated on alumina was applied for hydrogenation reaction, whereas cracking function was accomplished by ultrastable Y (USY) zeolite. The central objective of the thesis was to study the fundamental effect of extra framework aluminum (EFAl) species forming with the hydrothermal treatment of USY on hydrocracking of selected model compound – n-hexadecane. Three commercial USY zeolites with different SiO2/Al2O3 ratios were steamed until they reached down to the conversion curve of the reference USY sample physically mixed with 1% Pt supported on alumina in a 1:10 ratio. XRD patterns showed that the crystalline faujasite structure was kept after steaming. In the physisorption of argon, slight changes were observed in surface area and pore volumes which were correlated to the structural collapse of the zeolite framework. Dealumination of the zeolite framework was verified by 27Al MAS NMR. FTIR spectroscopy of pyridine adsorption and TPD of ammonia were employed to investigate the acidity of the samples. From the results, it was found that the concentration of Brønsted acid sites was the main contributor to the activity-acidity relationship in n-hexadecane hydrocracking. To gain more insight into the relationship, samples were subjected to n-hexane cracking. Turnover frequency analysis supported the proposal about hydrocracking reaction and also revealed the chemical influence of EFAl on Brønsted acidity observed in catalytic cracking of hexane.

Owing to climate change, natural forest disturbances and consecutive salvage logging are drastically increasing worldwide, consequently increasing the importance of understanding how these disturbances would affect biodiversity conservation and provision of ecosystem services. In chapter II, I used long-term water monitoring data and mid-term data on α-diversity of twelve species groups to quantify the effects of natural disturbances (windthrow and bark beetle) and salvage logging on concentrations of nitrate and dissolved organic carbon (DOC) in streamwater and α-diversity. I found that natural disturbances led to a temporal increase of nitrate concentrations in streamwater, but these concentrations remained within the health limits recommended by the World Health Organization for drinking water. Salvage logging did not exert any additional impact on nitrate and DOC concentrations, and hence did not affect streamwater quality. Thus, neither natural forest disturbances in watersheds nor associated salvage logging have a harmful effect on the quality of the streamwater used for drinking water. Natural disturbances increased the α-diversity in eight out of twelve species groups. Salvage logging additionally increased the α-diversity of five species groups related to open habitats, but decreased the biodiversity of three deadwood-dependent species groups. In chapter III, I investigated whether salvage logging following natural disturbances (wildfire and windthrow) altered the natural successional trajectories of bird communities. I compiled data on breeding bird assemblages from nine study areas in North America, Europe and Asia, over a period of 17 years and tested whether bird community dissimilarities changed over time for taxonomic, functional and phylogenetic diversity when rare, common and dominant species were weighted differently. I found that salvage logging led to significantly larger dissimilarities than expected by chance and that these dissimilarities persisted over time for rare, common and dominant species, evolutionary lineages, and for rare functional groups. Dissimilarities were highest for rare, followed by common and dominant species. In chapter IV, I investigated how β-diversity of 13 taxonomic groups would differ in intact, undisturbed forests, disturbed, unlogged forests and salvage-logged forests 11 years after a windthrow and salvage logging. The study suggests that both windthrow and salvage logging drive changes in between-treatment β-diversity, whereas windthrow alone seems to drive changes in within-treatment β-diversity. Over a decade after the windthrow at the studied site, the effect of subsequent salvage logging on within-treatment β-diversity was no longer detectable but the effect on between-treatment β-diversity persisted, with more prominent changes in saproxylic groups and rare species than in non-saproxylic groups or common and dominant species. Based on these results, I suggest that salvage logging needs to be carefully weighed against its long-lasting impact on communities of rare species. Also, setting aside patches of naturally disturbed areas is a valuable management alternative as these patches would enable post-disturbance succession of bird communities in unmanaged patches and would promote the conservation of deadwood-dependent species, without posing health risks to drinking water sources. / In Folge des Klimawandels treten in Wäldern vermehrt natürliche Störungen auf, wodurch wiederum die Zahl an nachfolgenden Sanitärhieben (Räumungen) drastisch gestiegen ist. Wie sich natürliche Störungen und Sanitärhiebe auf die biologische Vielfalt und die Bereitstellung von Ökosystemleistungen auswirken können, ist bisher jedoch nur unzureichend bekannt. In Kapitel II nutzte ich langfristige Wassermonitoringdaten und mittelfristige Biodiversitätsdaten über zwölf Artengruppen, um die Effekte von natürlichen Störungen (Windwurf und Borkenkäfer) und Sanitärhieben auf die Konzentrationen von Nitraten und gelöster organischer Kohlenstoffe (GOK) in Bächen und Artenzahl zu quantifizieren. Die Ergebnisse zeigen, heraus, dass natürliche Störungen zu einer temporären Erhöhung der Nitratwerte führen, welche dennoch laut Angaben der Weltgesundheitsorganisation immer noch als unbedenklich eingestuft werden können. Die Sanitärhiebe hatten keinen zusätzlichen Einfluss auf die Nitrat- und GOK-Konzentrationen und daher keinen Einfluss auf die Wasserqualität. Daraus lässt sich schließen, dass sich weder natürliche Waldstörungen in Wassereinzugsgebieten noch die damit verbundenen Sanitärhiebe auf die Trinkwasserqualität aus auswirken. Natürliche Störungen erhöhten die Artenzahlen in acht von zwölf Artengruppen. Zusätzlich erhöhten die Sanitärhiebe die Artenzahlen von fünf Artengruppen, welche auf offene Lebensräume angewiesen sind, verringerte jedoch die Artenzahlen von drei xylobionte Artengruppen. In Kapitel III habe ich untersucht, ob Sanitärhiebe nach natürlichen Waldstörungen zu sukzessiven Veränderungen der Vogelgemeinschaften führen. Hierzu habe ich die taxonomische, funktionelle und phylogenetische Diversität von Brutvogelgemeinschaften aus neun Untersuchungsregionen in Nordamerika, Europa und Asien über die Zeit von 17 Jahren verglichen und analysiert, ob sich das jeweilige Diversitätsmaß verändert, wenn seltene, häufige und dominante Arten unterschiedlich gewichtet werden. Ich konnte zeigen, dass Sanitärhiebe zu signifikant größeren Unterschieden geführt haben als zufällig zu erwarten gewesen sind und dass diese Unterschiede über die Zeit sowohl für seltene, häufige und dominante Arten, als auch für evolutionäre Linien, und funktionelle Gruppen fortdauern. Diese Unterschiede waren am größten für seltene, gefolgt von häufigen und dominanten Arten. In Kapitel IV untersuchte ich wie sich die β-Diversität von 13 taxonomischen Gruppen zwischen ungestörten Wäldern, gestörten und ungeräumten Wäldern sowie gestörten und geräumten Wäldern 11 Jahre nach Windwurf und anschließender Räumung unterscheidet. Die Ergebnisse deuten darauf hin, dass sowohl Windwurf als auch Räumung Änderungen in der β-Diversität bewirken. Windwurf allein jedoch scheint diese Änderungen in der β-Diversität innerhalb der Behandlung bewirken zu können. Über ein Jahrzehnt nach dem Windwurf war der Effekt des Sanitärhiebes auf die β-Diversität innerhalb der Behandlung nicht mehr nachweisbar. Der Effekt auf die β-Diversität zwischen den Behandlungen blieb jedoch bestehen, wobei sich die xylobionten Gruppen und seltenen Arten stärker veränderten als die nicht-xylobionten Gruppen oder häufigen und dominanten Arten. Basierend auf diesen Ergebnissen schlage ich vor, dass der Einsatz von Sanitärhieben sorgfältig gegen ihre langfristigen Auswirkungen auf Gemeinschaften seltener Arten abgewogen werden muss. Zusätzlich, besteht mit dem Belassen von natürlich gestörten Waldgebieten eine wertvolle Managementalternative, da diese Flächen eine natürliche Entwicklung von Vogelgemeinschaften ermöglichen und xylobionte Arten fördern, ohne dass die Trinkwasserqualität negativ beeinträchtigt wird.

The molecular species of diacylglycerol and alkylacylglycerol of Madin-Darby canine Kidney (MDCK) cells were analyzed to determine the sources of diradylglycerols generated during cell growth and phorbol ester stimulation. MDCK cells in log phase growth contained higher levels of diacylglycerol and alkylacylglycerol than confluent cells. Both subclasses of diradylglycerol showed higher levels of saturated and monoenoic species during log phase. Glycerol incorporation into diradylglycerols was increased during growth, consistent with an increase in their synthesis de novo. Stimulation with 12-O-tetradecanoylphorbol-13-acetate (TPA), a potent activator of protein kinase C, caused an increase in the level of diacylglycerol but not alkylacylglycerol. Log phase MDCK cells showed a greater response to TPA treatment than confluent cells. The molecular species of diacylglycerol generated during stimulation with either TPA or dioctanoylglycerol closely resembled the species of phosphatidylcholine. These results indicate that TPA and synthetic diacylglycerol stimulate endogenous diacylglycerol production through the hydrolysis of phosphatidylcholine. In contrast, the higher content of diacylglycerol and alkylacylglycerol in replicating MDCK cells is the result of an increase in their synthesis de novo.

Flavonoids play crucial roles in plant life cycles and in human welfare. Grapefruit plants produce several glycosylated flavonoids and the glycosylation reactions are catalyzed by UDP-glucose: glucosyltransferases (GTs). Our objective was to use the SMART RACE RT-PCR strategy to obtain cDNA sequences of putative grapefruit flavonoid GTs. Gene specific primers were designed from the plant secondary product glucosyltransferase (PSPG) box and used to amplify 5’GT clones. Clone-specific primers were designed from 5’clones to amplify 3’ GT clones. We obtained 5 5’ clones and 1 3’ clone as candidate GTs. We used 3 of these clones to predict 2 compiled GT sequences. Structural comparison of the putative GTs with functionally known GTs from other plants showed an overall low pair-wise sequence identity (11-31%), but high identity (52.2-75%) within the PSPG box. We conclude that assignment of function from sequence information is not appropriate; assignment should depend on biochemical characterization of expressed GT enzymes.

Tree peony is known worldwide for its excellent ornamental and medical values, but recent reports that their seeds contain over 40% α-linolenic acid (ALA), an essential fatty acid for humans drew additional interest of biochemists. To understand the key factors that contribute to this rich accumulation of ALA, we carried out a comprehensive study of oil accumulation in developing seeds of nine wild tree peony species. The fatty acid content and composition was highly variable among the nine species; however, we selected a high- (P. rockii) and low-oil (P. lutea) accumulating species for a comparative transcriptome analysis. Similar to other oilseed transcriptomic studies, upregulation of select genes involved in plastidial fatty acid synthesis, and acyl editing, desaturation and triacylglycerol assembly in the endoplasmic reticulum was noted in seeds of P. rockii relative to P. lutea. Also, in association with the ALA content, transcript levels for fatty acid desaturases (SAD, FAD2 and FAD3), which encode for enzymes necessary for polyunsaturated fatty acid synthesis were higher in P. rockii compared to P. lutea. We further showed that the overexpression of PrFAD2 and PrFAD3 in Arabidopsis increased linoleic and α-linolenic acid content, respectively and modulated their final ratio in the seed oil. In conclusion, we identified the key steps that contribute to efficient ALA synthesis and validated the necessary desaturases in P. rockii that are responsible for not only increasing oil content but also modulating 18:2/18:3 ratio in seeds. Together, these results will aid to improve essential fatty acid content in seeds of tree peonies and other crops of agronomic interest.

The increasing need for healthy edible oil has driven us to identify α-linolenic acid (ALA)-rich species and identify key biochemical steps in ALA synthesis. Seeds of tree peony species are rich in unsaturated fatty acid content with > 40% ALA in the total fatty acid. However, fatty acid content and composition is variable among the tree peony germplasm. To this extent, a comparative study was carried out to identify the key genes responsible for differential oil accumulation among nine wild tree peony species. Subsequent to analyzing fatty acid content and composition of the seeds from nine tree peony species, a high- (P. rockii) and low-oil (P. lutea) accumulating species were selected for transcriptome analysis. Gene expression analysis revealed upregulation of select genes involved in plastidial fatty acid synthesis, and acyl editing, desaturation and triacylglycerol assembly in the endoplasmic reticulum in seeds of P. rockii relative to P. lutea. Also, in association with ALA content in seeds, transcript levels for fatty acid desaturases (SAD, FAD2 and FAD3), which encode for enzymes necessary for polyunsaturated fatty acid synthesis were higher in P. rockii compared to P. lutea. Additionally, we showed that the overexpression of PrFAD2 and PrFAD3 in Arabidopsis increased linoleic and α-linolenic acid content, respectively and modulated their final ratio in the seed oil. In conclusion, we identified the key steps that contribute to efficient ALA synthesis and validated the necessary desaturases in P. rockii that are responsible for not only increasing oil content but also modulating 18:2/18:3 ratio in seeds. Together, these results will aid to improve essential fatty acid content in seeds of tree peonies and other crops of agronomic interest.

Determining the activity among species-specific bat populations within specific habitat selections can help contribute to the conservation of Appalachian bat species. This study examines the differences in species-specific bat activity patterns between three ponds of variable sizes and a southeast-facing open field with a wooded edge. Four Song Meter SM4BAT FS bioacoustics detectors were used on a 15-acre property in Fall Branch, TN, with a wildlife acoustics detector being placed at three ponds and one field. There were three stages of data collection for this study which all took place during 2023. The first stage was during the spring (March 18th – May 18th), the second stage was during the summer (June 21st – August 27th), and the third stage was during the fall (September 26th – October 26th). Acoustic recordings were analyzed through SonoBat to classify them to species level using a recording call quality threshold of ≥ 95%. An identification likelihood of ≥ 90% yielded 36,308 calls assigned to a particular species/genus. The acoustic detectors detected eight bat species and the Myotis genus throughout the study. Species identified include Rafinesque's big-eared bat (Corynorhinus rafinesquii), big brown bat (Eptesicus fuscus), hoary bat (Lasiurus cinereus), silver-haired bat (Lasionycteris noctivagans), eastern red bat (Lasiurus borealis), evening bat (Nycticeius humeralis), tricolored bat (Pipistrellus subflavus), Mexican free-tailed bat (Tadarida brasiliensis), and species within the Myotis genus. Two chi-square analyses were performed through R to determine if there were significant spatial and temporal species-specific activity patterns between the four sites. Both chi-square analyses resulted in a p-value < 2.2e-16 indicating significant differences in species-specific activity levels between the four sites throughout spring, summer, and fall. This data can help species-specific conservation efforts by understanding bat species’ activity levels at particular habitat selections throughout the fall, summer, and spring seasons.

I constructed a best estimate phylogeny based on congruence of multiple data sources. In recent years molecular data has been used both to construct phylogenies of taxonomic groups and to aid in the delimitation of new species. I generated and analyzed sequence data for forest spiny pocket mice (Genus Heteromys) for the mitochondrial gene cyt b (1143 bp) and two nuclear gene segments MYH2 (252 bp) and EN2 (189 bp). I used maximum parsimony and Bayesian analyses to infer relationships among species and to provide a framework for using a species delimitation method to investigate the possibility of multiple species within the widespread Heteromys desmarestianus. I found several well-supported lineages within the H.desmarestianus complex, including H. goldmani and H. oresterus. Incorporating karyotype and allozyme data from earlier studies, I found sufficient supporting evidence to justify maintaining H. goldmani and H. oresterus as species as well as identifying four lineages as candidate species. I present a revised taxonomic arrangement within the genus; the subgenus Heteromys should be divided into three species groups: anomalus (H. anomalus and H. australis), gaumeri (H. gaumeri), and desmarestianus (H. desmarestianus, H. goldmani, H. oresterus, and the four candidate species).

As part of a medico-legal analysis it is necessary to identify if bone tissue is animal or human in nature. This process is complicated when bone is highly fragmented or burned. Previous research has established the ability to differentiate human from non-human bone histologically, however, further research is necessary to determine if this is still applicable in the case of burned remains. In South Africa, approximately 500 deaths and 15 000 fire related injuries occur annually in Cape Town and such fires ranged between 600°C to 1000°C. The aim of this research was to study the qualitative and quantitative characteristics of femur bone microstructure of human and animal bones exposed to different temperatures and to determine the possibility of distinguishing them. The study consisted of 17 femoral bone samples collected from four different species namely; humans (Homo sapiens), pig (Sus scrofa), wildebeest (Connochaetes gnou) and cow (Bos taurus). Unburned samples were compared to bone samples burned at 600°C, 700°C, 800°C and 900°C in a muffle furnace for 20 minutes. Bone samples were processed into thin sections for histological analysis. During analysis, each bone specimen was divided into four quadrants and two periosteal regions. For histomorphometric analysis, quantitative characteristics were assessed by measuring the area, perimeter, and minimum and maximum diameter of the Haversian system and Haversian canals as well as osteon circularity and osteon density. According to the qualitative results, the main structural bone tissue observed in all quadrants and two periosteal regions of unburned animal bone was primary vascular plexiform bone and irregular Haversian bone. Human bone consisted of dense Haversian bone. Quantitative results indicated a statistically significant difference in most parameters between species within burned as well as unburned samples (p<0.001). Statistically significant differences in quantitative parameters within human and wildebeest bone were noted at different burn temperatures (p<0.001). Overall, the results showed that heat exposure to bones can affect the bones' quantitative and qualitative characteristics but human and non-human bones can still be differentiated. This histological method can be used in forensic fire cases.

The United States has an abundant stock of naturalized wild growing bamboo species that are generally considered invasive. This project explores the use of locally harvested, so called “invasive” bamboo as a potential building material incorporated into a modular, kit-of-parts style construction system. These structures are uniquely suited to address the need for expanded spaces and extensions that bridge between the strictly indoor vs. outdoor distinction of existing buildings, as revealed by the Covid-19 pandemic. The rhizomatic mechanism of spread that is characteristic of bamboo species is used as the framework to propose a tectonic system that is decentralized, adaptable, and deployable. Drawing on a series of formal explorations, this system is further developed through a case study proof of concept design for Morningside Elementary School in Atlanta, GA, by supplementing, expanding, and adapting the existing facilities for eating, gathering, recreation, and learning to address the requirements of a Covid-19 safe school environment and to propose an ongoing outdoor learning program.