Digital Commons Network^™

Photocatalytic Degradation Of Lignin By Supported Silver Nanoparticles, Ning Wei

Theses and Dissertations--Chemical and Materials Engineering

Lignin is the second most abundant form of biomass on earth. The phenolic structure and high carbon to oxygen ratio make lignin an attractive renewable source of fuel and chemicals. However, its recalcitrance and heterogeneous nature prove difficult for decomposing lignin’s polymer structure and separation of the products. This work has focused on the use of low-energy catalytic approaches to overcome these barriers. A mimic of the lignin degrading enzyme laccase, consisting of a copper cluster Cu4Py4I4 modified with AgNO3, was developed to function similarly to the laccase active site. The prepared copper complex solution was found to be active …

The Role Of Charge On Dna Packaging And Integrity Within Reconstituted Peptide-Dna Assemblies, Ehigbai Oikeh

Theses and Dissertations--Chemistry

In nature, DNA exists primarily in a highly compacted form. The compaction of DNA in vivo is mediated by cationic proteins; histone in somatic nuclei and arginine-rich peptides called protamines in sperm chromatin. The packaging in the sperm nucleus is significantly higher than somatic nuclei resulting in a final volume roughly 1/20^th that of a somatic nucleus. This tight packaging results in a near crystalline packaging of the DNA helices. While the dense packaging of DNA in sperm nuclei is considered essential for both efficient genetic delivery as well as DNA protection against damage by mutagens and oxidative species, …

Development Of Fluorescence Based Approaches To Understand Astrocyte Biology In The Context Of Nicotine And Nicotinic Receptor Activity, Surya P. Aryal

Theses and Dissertations--Chemistry

Smoking and tobacco use (STU) is a major global health problem and worldwide more than six million people die due to tobacco related diseases each year. Although majority of smokers try to quit smoking several times in their life, traditional therapeutic approaches, which focus only on neuronal cells, have a very low success rate. Understanding the effect of nicotine on glial cells, synaptic communication and blood vasculature in the brain can provide further insights on the neurobiology of substance abuse and can potentially help to design better therapeutic approaches. Glial cells are non-excitable cells in the brain which do not …

Application Of Mass Spectrometry For Characterization Of Plant-Based Phenolics And Alkaloids, Masoumeh Dorrani

Theses and Dissertations--Chemistry

Plant-derived compounds have the potential to produce value-added compounds with a variety of applications. For example, the lignin part of the lignocellulosic biomass, produced in large quantities as waste from the paper and pulp industries, is a rich source of phenolics with potential applications in the renewable energy sector, pharmaceutical, and chemical industries. On the other hand, plant alkaloids are the primary source for developing plant-derived therapeutics. Unfortunately, the recalcitrant nature of plant cell walls, low extraction yields of small secondary metabolites, and the lack of effective analytical methods for a rapid and accurate identification of plant-based compounds and plant’s …

Structural Basis Of Bacterial Flagellin For Naip5 Binding And Nlrc4 Inflammasome Activation And The Mechanism Of Flagellin Induced Release Of Cytokines In Vivo, Jian Cui

Theses and Dissertations--Chemistry

The bacterial flagellum is a whip-like structure that protrudes from the cell membrane and is one of the most complex and dynamic biological molecular machines that propels bacteria to swim toward beneficial environments and the sites of infection. It is composed of a basal body, a hook, and a long filament. The flagellar filament contains thousands of copies of the protein flagellin (FliC) monomer arranged helically and ending with a filament cap composed of oligomer protein FliD. The overall structure of the filament core is preserved across bacterial species, while the outer domains exhibit high variability, and in some cases …

Mechanism Of Antibiotic Permeability Through The Gram-Negative Bacterial Envelope, Olaniyi Alegun

Theses and Dissertations--Chemistry

The outer membrane of Gram-negative bacteria (GN) makes them distinct among superbugs that are associated with the development of antibiotic resistance. The outer membrane, and inner membrane, separated by the periplasm, form a double-membrane barrier to the entry of antibiotics into the cell. Several studies have been conducted to examine the role of outer membrane modifications such as porins, lipopolysaccharides, and efflux pumps on antibiotic resistance. However, there is a paucity of knowledge on how antibiotics behave in the periplasm, to gain access into their target region. My thesis focuses on understanding the mechanism of antibiotic permeability through the cellular …

Antibiotic Permeation In Gram-Negative Bacteria And Contribution Of Inflammasome Activation And Pyroptosis In Pathogenesis Of Salmonella Systemic Infection, Ankit Pandeya

Theses and Dissertations--Chemistry

Antibiotic resistance is one of the major global issues in the field of public health and medicine. Good antibiotic candidates need to be selectively toxic, inhibit cellular target, and effectively penetrate and accumulate in bacterial cells. The last factor is a formidable barrier in the development of antimicrobials effective in Gram-negative bacteria, due to the presence of two layers of cell envelope. The first half of my thesis focuses on understanding the permeation of small molecules through this formidable cell envelope, distribution inside the cell of Gram-negative bacteria, and design of novel methods to make small molecules effectively cross the …

Nicotine And Cotinine: Microbial Modulators Of The Immune Response, Jourdan Lakes

Theses and Dissertations--Chemistry

The consumption of tobacco products is a known contributor to a variety of health conditions and disease pathologies including cardiovascular and lung diseases. In addition to these well-known pathological effects of tobacco use, it has been established recently that tobacco consumption as well as nicotine consumption alone results in distinct, dysbiotic perturbations to the enteric microflora of the gastrointestinal tract. Previous research into the intestinal microbiome has demonstrated that these microbes are active contributors to the maintenance of a homeostatic and tolerogenic environment within the host. In fact, the presence of our enteric microflora is necessary for the proper development …

Developments In Gold(Iii) Scaffolds For Protein Bioconjugation And Enhanced Anticancer Activity, Sailajah Gukathasan

Theses and Dissertations--Chemistry

Site-selective modifications of target proteins using specially designed small molecules is a powerful tool that has been extensively utilized in biomedicine. Small molecules can modify proteins either covalently or non-covalently depending on their structures and intrinsic chemical reactivity. Covalent chemical modification presents a more stable and often irreversible interaction with target proteins; unlike non-covalent binders, which form weak, reversible interactions with protein. Therefore, covalent modifiers represent an effective class of therapeutics due to their stability and irreversibility once bound to target proteins of interest. I hypothesized that tuning biocompatible, high-valent gold(III) complexes toward nucleophile-induced reductive elimination will lead to covalent …

Cell-Engineered Vesicles For Therapeutic Delivery And Immunomodulatory Applications, Khaga Neupane

Theses and Dissertations--Chemistry

Development of a new kind of drug delivery system (DDS) that could efficiently deliver therapeutics to the cell of interest would allow us to accomplish cell-specific drug delivery while eliminating systemic toxicity. Although nanocarriers including endogenously released extracellular vesicles (EEVs), liposomes, and small molecules seem to be promising drug delivery systems, biological challenges persist for their use in clinical applications. Here, we demonstrate nanovesicles engineered by fragmenting cellular membranes can be exploited as versatile DDSs for therapeutics delivery as well as immunomodulatory functions. Cell-engineered vesicles were produced by cavitating cells using nitrogen gas at high pressure followed by serial centrifugation. …

Mild Cognitive Impairment In Presurgical Deep Brain Stimulation For Parkinson's Disease, Elizabeth Roslyn Wallace

Theses and Dissertations--Psychology

Although clinically characterized by motor impairments, Parkinson's disease (PD) often affects cognition early in the disease course. Cognitive changes common in PD include visuospatial abnormalities and prominent executive function (EF) deficits, with 30% of individuals eventually developing Parkinson’s disease dementia (PDD). Mild cognitive impairment (MCI) has been identified as a transitional state between normal cognition and PDD. A large cohort of individuals with PD at the Kentucky Neuroscience Institute have undergone pre-surgical evaluations for deep brain stimulation, although cognitive performance in this cohort has never been probed. Baseline cognitive performance of this cohort from 2017-2020 was examined to characterize the …

The Measurement Of Product Typicality In Design Research. A Basic And Applied Approach, Travis Kent

Theses and Dissertations--Psychology

The objective of this study was to examine the use of the cognitive construct of “typicality” to guide design decisions in the development of consumer products. Increasing products that will appeal to consumers, designers strive to balance novelty and familiarity. A potential way to thread this needle is to understand how “typical” a design is of its particular product category. The construct of typicality has been used by psychologists to understand how people create and represent categories. Objects that are more typical of a category are often associated with positive responses from observes (e.g., greater visual appeal, faster recognition). In …

Effects Of An Online Insomnia Intervention On Sleep And Alcohol Consumption, Justin Verlinden

Theses and Dissertations--Psychology

Alcohol use disorder (AUD) and insomnia are highly comorbid, due in part to the use of alcohol as a sleep aid among individuals with insomnia. Initial studies have shown that cognitive behavioral therapy for insomnia (CBT-I), the first-line treatment for insomnia, is moderately successful at improving both sleep and drinking outcomes in heavy drinkers with insomnia. However, CBT-I is expensive and not widely available. Online CBT-I could be a more accessible alternative. One online CBT-I program, Sleep Healthy Using the Internet (SHUTi), is especially promising due to its high efficacy in treating insomnia and its individualized and interactive platform. Here …

Classic Period Dune Settlement In The Eastern Lower Papaloapan Basin, Southern Veracruz, Mexico, Kyle Edward Mullen

Theses and Dissertations--Anthropology

This dissertation is an archaeological investigation into the long-term settlement change of an ecologically distinct portion of the Eastern Lower Papaloapan Basin (ELPB) of southern Veracruz, Mexico, before, during, and after the fluorescence of the Tres Zapotes polity. This project examines the changing settlement history in an area of near-coastal paleodunes and estuarine lakes in the northern ELPB, addressing the question: “What processes account for variations in the distribution of occupation on the dune landscape through time?” I argue that the answer lies at the intersection of specific environmental, economic, and political factors in the ELPB over time.

Assessing Stress Biomarkers As Embodied Identity In Kentucky’S Green River Archaic, Anna-Marie Casserly

Theses and Dissertations--Anthropology

The primary goal of this bioarchaeology dissertation research is to investigate the relationship between evidence of social identity and indicators of biological stress in the Green River region of Kentucky during the Late Archaic period (5,000-3,000 BP). Utilizing a biocultural perspective, I examine the ways that aspects of identity and social organization are embodied through the experience of biological stress. This research explores how social differences influence the patterning of osteological stress markers in an Archaic population while problematizing categories of difference that are often naturalized in bioarchaeology, such as gender or age cohorts. In so doing, it contributes to …

Otavalan Women Weavers: Rethinking Gendered Labor And Crafts In Ecuador, Kaitlin Marie Zapel

Theses and Dissertations--Anthropology

This research focuses on the gendered labor of craft production and distribution of Otavaleños, an indigenous group in the Imbabura Valley in the Andes Mountains of Ecuador. Otavalans are often described as a society of weavers with strong gender divisions. Households typically function as units of production, with tasks ideally broken down along gender lines. Women are generally depicted as secondary workers who do not weave the textiles that make Otavalans famous; however, they are generally perceived as being responsible for selling these textiles in the market. This research argues that current gendered labor relations in Otavalan textile production can …

Career Development And Employability Skill Integration Within The Equine Science And Management Undergraduate Program At The University Of Kentucky, Savannah Faye Robin

Theses and Dissertations--Educational Leadership Studies

College graduates need to be equipped with career and employability skills that are necessary to be meaningfully and gainfully employed in their future. These skills consist of self-management, career-management, essential-employability, and discipline-specific skills. More responsibility is being placed on college and university academic programs to ensure that students are graduating with these skills when they enter the workforce. However, students are growing less likely to participate in out of course career development activities and resources. Integrating these skills into program curriculum can be an effective way to ensure that all students have the ability to develop these necessary skills.

While …

The Appalachian Commitment Of Berea College: A Review Of Historical Figures, Narratives, And An Analysis Of Programmatic Outcomes, Rebecca E. Tucker

Theses and Dissertations--Education Sciences

Since its founding in 1855 Berea College has continuously defined and redefined itself based on eight Great Commitments that collectively shape Berea’s mission. All Bereans, from students to alums to Presidents, have a responsibility to review and evaluate the ways in which Berea College is acting on each of its eight Commitments. This study offers a review of Berea’s Appalachian Commitment, “To engage Appalachian communities, families, and students in partnership for mutual learning, growth, and service” (Berea College, 2017). The following three articles seek to understand some of the ways in which Berea College leaders have interpreted and acted on …

Development Of The Elementary Teachers’ Commitment To Outdoor Education Survey: A Mixed Methods Study, Sagan Goodpaster

Theses and Dissertations--Education Sciences

As the Green Schoolyards Movement continues to grow throughout North America, outdoor education (OE) is gaining more attention in the formal K-12 curriculum (Dyment, 2005; Sterrett & Imig, 2015). Rooted in the pedagogies of place-based and experiential learning, outdoor instruction provides social, psychological, physical, and academic benefits for students, and fosters their sense of connection to the natural environment (Dubel & Sobel, 2008; Robertson, 2017). In particular, outdoor learning opportunities have been shown to promote greater gains in students’ scientific content knowledge (Carrier et al., 2014; Cronin-Jones, 2000; Dirks & Orvis, 2005; Kenney et al., 2003). Outdoor instruction involves students …

Long Term Observation Of The Grassland Vegetation Used Intensively Or Extensively And Ecologically, H.-D. Matthes, J. Matthes, W. Jentsch, V. Pastushenko

IGC Proceedings (1977-2023)

The aim of the present paper was to study alterations of the grassland flora from 55 plots following a more extensive management under long term observation within 6 years. Extensification of grassland use leads to an increase of the numbers of plant species by 32%, “Red-list-species” included. The moisture number of the soils slightly increased and the reaction and nitrogen numbers decreased. Results are presented for different vegetation units.

Influence Of Extensive Management On Botanical Composition Of Permanent Meadow Sward, K. Mlynarczyk, E. Korona, E. Marks

IGC Proceedings (1977-2023)

The aim of undertaken investigations was to find the possibilities of grassland management with special respect to the biodiversity and the landscape conservation. Changes in botanical composition of the meadow sward against a background of different mowing utilization were examined on the semi-natural meadows situated on the peat-mursh soil in Masurian Landscape Park (north-east Poland). The areas mown with biennial pause and completely turned off from uses followed gradual simplifying of species composition and increasing of bog species participation. Results show on advisability of passing one harvest each year or with one-year pauses.

Vegetation Changes In Sown Grassland In The Uk After Nine Years Of Extensive Grazing Management, C. A. Marriott, G. T. Barthram

IGC Proceedings (1977-2023)

The effect of extensive grazing management with sheep on vegetation change in sown pastures (initially containing Lolium perenne and Trifolium repens) in the uplands of Scotland was investigated from 1990-1999. One treatment was representative of current more intensive management systems; it was fertilized, and maintained at a sward surface height of 4 cm. Two treatments were unfertilized and were maintained at sward surface heights of 4 cm or 8 cm; the ewe numbers carried on these treatments averaged 74% and 44%, respectively, of those on the fertilized treatment. In all treatments the sheep were Scottish Blackface ewes. Their single …

The Influence Of Rising Atmospheric Co2 On Grassland Ecosystems, J. A. Morgan, P. C. D. Newton, J. Nösberger, C. E. Owensby

IGC Proceedings (1977-2023)

Increasing atmospheric CO₂ concentrations and climatic change will have significant effects on the ecology of grasslands. This paper evaluates results from four CO₂ enrichment studies in contrasting grasslands. A Swiss study investigates the effects of elevated CO₂ (600 μL L^-1 CO₂) on perennial ryegrass (Lolium perenne L.) and white clover (Trifolium repens L), a New Zealand study examines how elevated CO₂ (475 μL L^-1 CO₂) affects a botanically diverse pasture, and studies in the Kansas tallgrass prairie and the Colorado shortgrass steppe investigate the effects of an approximate …

Rangeland Desertification In China, Wang Tao

IGC Proceedings (1977-2023)

Land desertification is one of the most serious environmental and social-economic problems in the North China. The processes of desertification mainly have being controlled by the interaction of human activities and fragile eco-environment, that means the pattern and intension of landuse are major factors for development or reverse of desertification. Because of the increasing pressure of population, the rangeland in the North China has being cultivated decade by decade, which changed landuse from grassing to cropping in a large area and destroyed the natural vegetation cover. The result is to let the wind erosion become easier and the desertification has …

Grasslands, Communicating The Benefits, D. Keeney

IGC Proceedings (1977-2023)

The multiple benefits of perennial agriculture , including forages and grasslands, for building soil quality, protection of natural resources, enhancement of biodiversity and wildlife, are well known to us, but little understood by the public. This is not a situation where “more education” would necessarily increase recognition. Rather, we must build in the public a desire for the enhancement of green space, clean water and air, and diverse landscapes that multiple purpose agriculture can bring. We seek such environments intuitively and now that much of the world’s people are “trapped” in urban settings of steel and concrete, this desire is …

Agropastoral Systems An Alternative To Revert Pasture Degradation In The Cerrados Of Brazil: Preliminary Results, Manuel C. M. Macedo, J. A. M. Bono, A. H. Zimmer, F. P. Costa, Tsutomu Kanno, Cesar Heraclides Behling Miranda, A. N. Kichel

IGC Proceedings (1977-2023)

A long term experiment was set to test the hypothesis that agropastoral systems could improve crop and animal production, being more profitable and sustainable relative to economical, biological and environmental aspects, than continuous and traditional crop and grazing pasture systems. Five farming systems are being tested: two traditional (continuous soybean annual cropping and continuous pasture cropping) and three agropastoral systems (two combinations of four by four years of rotational crop-pasture systems and one by three years of crop-pasture rotation). Animal production in continuous pasture cropping measured as liveweight gain/ha (LWG) are declining along the years in the sub-treatment without fertilizer …

Inhibition Of Bruton Tyrosine Kinase Reduces Neuroimmune Cascade And Promotes Recovery After Spinal Cord Injury, Chen Guang Yu, Vimala Bondada, Hina Iqbal, Kate L. Moore, John C. Gensel, Subbarao Bondada, James W. Geddes

Physiology Faculty Publications

Microglia/astrocyte and B cell neuroimmune responses are major contributors to the neurological deficits after traumatic spinal cord injury (SCI). Bruton tyrosine kinase (BTK) activation mechanistically links these neuroimmune mechanisms. Our objective is to use Ibrutinib, an FDA-approved BTK inhibitor, to inhibit the neuroimmune cascade thereby improving locomotor recovery after SCI. Rat models of contusive SCI, Western blot, immunofluorescence staining imaging, flow cytometry analysis, histological staining, and behavioral assessment were used to evaluate BTK activity, neuroimmune cascades, and functional outcomes. Both BTK expression and phosphorylation were increased at the lesion site at 2, 7, 14, and 28 days after SCI. Ibrutinib …

Water-Use Efficiency And Infiltration Under Different Rangeland Conditions And Cultivation In A Semi-Arid Climate Of South Africa, Hennie A. Snyman

IGC Proceedings (1977-2023)

The objective of this study was to determine the impact of rangeland in different botanical composition classes (good, moderate and poor), on water-use efficiency (WUE: crude protein produced per unit of evapotranspiration) and soilwater content. The same measurements were also made on an undisturbed bare soil surface and soil cultivated twice per annum. Evapotranspiration was determined by quantifying the soil-water balance equation with the aid of runoff plots and soil-water content measurements done by a neutron hydroprobe. Water-use efficiency declined significantly (P ≤ 0.01) with rangeland degradation. Rangeland in good condition averaged a WUE of 0.28 kg crude protein ha …

Valuing The Pasture Resource - Importance Of Perennials In Higher Rainfall Regions Of South Eastern Australia, P. M. Dowling, R. E. Jones, David R. Kemp, D. L. Michalk

IGC Proceedings (1977-2023)

The premature decline of perennial grass based pastures in southern temperate Australia results in poor productivity and unstable pastures that allow invasion by less desirable weedy species and the potential for soil degradation. The loss of perennial species is attributed to overgrazing arising from an undervaluation of the pasture resource. Resowing pastures is largely uneconomic so maintenance of, or increasing the perennial, is dependent on improved grazing and pasture management practices. A key to changing perceptions is valuing the true worth of the perennial component. Results are presented from a model that takes into account the seasonality of production of …

The Future For Savanna And Tropical Grasslands: A Latin American Perspective, R. R. Vera

IGC Proceedings (1977-2023)

The objective of the paper is to briefly review the main trends in the tropical lowlands of Latin America and the Caribbean (LAC) with particular emphasis in the neotropical savannas. These tropical native grasslands cover occupy approximately 210 million hectares, and constitute major portions of the territory of Bolivia, Brazil, Colombia, Guyana and Venezuela. Many analysts consider that intensification of their use is a valid alternative to the expansion of the livestock and crop industries into the rainforest.

The evidence reviewed shows that since the late 1980s, the LAC agricultural sector has shown dynamism not seen for many years. Despite …