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Notchless Interacts With Multiple Signaling Pathways During Mouse Peri-Implantation Development, Chiao-Ling Lo

Open Access Dissertations

During peri-implantation, the embryo transitions from a suspension environment in the fallopian tubes to an adherent system within the uterus. Successful transition requires maternal and fetal signaling cascades that establish maternal-fetal boundaries. Failure is common, as ~ 25% of all human pregnancies terminate during these steps. A large-scale mutation study in mice produced two mutants (l11Jus1 and l11Jus4) that are excellent models of this transition. l11Jus1 and l11Jus4 contain missense mutations in the Notchless homolog 1 (Drosophila) (Nle1) gene. NLE1 is thought to signal via the canonical NOTCH pathway in vertebrates. Although in invertebrates and lower vertebrates, NOTCH signaling directs …

Influence Of Cholesterol And Bilayer Asymmetry On Membrane Protein Distribution In Polymer-Tethered Raft-Mimicking Lipid Membranes, Noor Fueza Hussain

Open Access Dissertations

It is now widely recognized that lipid rafts, which are membrane domains enriched in cholesterol (CHOL) and sphingolipids (SL), play a significant functional role in the plasma membrane. Raft domains particularly affect membrane functionality by causing sequestering of membrane proteins. Underlying mechanisms of raft-associated membrane protein sequestration remain elusive, due to the complexity, transient nature, and small size of raft domains in cellular membranes. To address these challenges, this dissertation unveils the relationship between lipid raft composition and membrane protein sequestration and function using raft-mimicking model membrane mixtures comprised of coexisting liquid-ordered (lo) and liquid-disordered (ld) domains with reconstituted membrane …

Development Of A Field-Portable Miniature Mass Spectrometer Designed For In-Situ Analysis And Ion Trap Miniaturization, Paul Isaac Hendricks

Open Access Dissertations

Chemical analysis by mass spectrometry has become the gold standard due to the sensitivity, selectivity, and short analysis times that are afforded by the method. Advances in miniaturized vacuum systems, mass analyzers, electronics, and ionization sources have allowed for the development of field-portable mass spectrometers. The performance of portable instruments has received much attention for their utility in the detection of illicit drugs, explosives, environmental contaminants, therapeutic drugs, and more recently, biological tissues. Furthermore, detection of the aforementioned compounds can be completed at atmospheric pressures and in the presence of complex matrices and sample surfaces when used in conjunction with …

Estimation Of Variation For High-Throughput Molecular Biological Experiments With Small Sample Size, Danni Yu

Open Access Dissertations

Motivation: In the quantification of molecular components, a large variation can affect and even potentially mislead the biological conclusions. Meanwhile, the high-throughput experiments often involve a small number of samples due to the limitation of cost and time. In such cases, the stochastic information may dominate the outcome of an experiment because there may not be enough samples to present the true biological information. It is challenging to distinguish the changes in phenotype from the stochastic variation.

Methods: Since the biological molecules have been quantified with different technologies, different statistical methods are required. Focusing on three types of important high-throughput …

The Role Of Resource Predictability In The Metapopulation Dynamics Of Insects, Byju Nambidiyattil Govindan

Open Access Dissertations

The metapopulation paradigm has emerged as an important tool to understand the dynamics of species living in fragmented landscapes. In this dissertation, I investigate the unpredictable nature of resource availability for species living in human-dominated heterogeneous and dynamic landscapes in the context of its consequences for long-term regional persistence of species. In particular, I test theoretical advancements in metapopulation ecology following a two-pronged approach - via experiments in the lab and observations in the field - using insects. In chapter 1, I introduce the concept of metapopulation ecology in the context of its relevance for dynamics of species living in …

Functional Characterization Of Metallothioneins In Arabidopsis And Barley, Nimnara Yookongkaew

Open Access Dissertations

Metalothioneins (MTs) are metal binding proteins that can bind metals such as Cu, Zn, and Cd but the functions of MTs in plants are largely unknown. To understand the function of MTs in Arabidopsis, T-DNA insertion mutants lacking 4 MT genes including MT1a, MT2a, MT2b and MT3 were developed. The quadruple mutant (mt1a/mt2a/mt2b/mt3) showed no visible phenotype under standard growth conditions. However, it accumulated higher Cu in leaves compared to wild type but lower Cu in seeds. Further analysis showed that triple mutants lacking both MT1a and MT2b, which are highly expressed in vascular tissues, had similar …

An Eriksonian Approach To Consumer Identity, Sandra Rathod

Open Access Dissertations

Rathod, Sandra R. Ph.D., Purdue University, December 2013. An Eriksonian Approach to Consumer Identity. Major Professor: Richard A. Feinberg.

Ego development is the fifth stage in Erikson's Lifecycle Development theory (1959) and is a major psychosocial stage beginning in adolescence and lasting into emerging adulthood. Past research based upon Marcia's Ego Identity Status Paradigm (1996) has investigated a number of ideological and interpersonal domains relevant to one's ego identity, however in today's consumer societies, where what you have is at least as important is who you are or what you do, an Eriksonian approach to consumer ego identity (CEI) has …

An Analysis Of The Impact Of Storage Temperature, Moisture Content & Duration Upon The Chemical Components & Bioprocessing Of Lignocellulosic Biomass, Arun Athmanathan

Open Access Dissertations

The successful utilization of lignocellulosic biomass as a feedstock for fuels and chemicals necessitates storage for 2-6 months. It is correspondingly important to understand the impact of storage parameters - moisture concentration, temperature and duration - on biomass quality.

As aerobic storage is the most viable large-scale solution, aerobic storage experiments were carried out with three projected bioenergy feedstocks - sweet sorghum (Sorghum bicolor) bagasse, corn (Zea mays) stover and switchgrass (Panicum virgatum). Stored samples of each were examined for dry matter loss and composition change to develop a material balance around carbohydrates and lignin.

A mean dry matter loss …

Hybrid Opto-Electrokinetic Technique For Micro/Nanomanipulation: Towards Application Of A Novel Non-Invasive Manipulation Technique In Microbiological Assay, Jae-Sung Kwon

Open Access Dissertations

This dissertation explores various physical mechanisms of the Rapid Electrokinetic Patterning (REP) technique suggested for rapid and precise on-chip manipulation of colloids and fluids, and bio-compatibility of the technique for biological applications. REP is a hybrid opto-electrokinetic technique that is driven by the simultaneous application of an AC electric field and a heating source. It can not only effectively transport and manipulate a fluid but also concentrate and pattern particles suspended in the fluid through the combined effect of an electrohydrodynamic flow, electrostatic colloidal interactions and an electrothermal microfluidic flow. These capabilities make REP a promising tool which can provide …

The Role Of Soil Microorganisms In The Resistance Of Giant Ragweed, Horseweed, And Common Lambsquarters To Glyphosate, Jessica Renee Schafer-Bugg

Open Access Dissertations

Continuous glyphosate use has contributed to an increasing number of problematic glyphosate-resistant (GR) weeds. The mechanism of resistance in many GR weeds is poorly understood, in part, due to a poor understanding of how exactly glyphosate kills a plant. In previous research, the efficacy of glyphosate was demonstrated to be strongly influenced by root invading soil-borne microorganisms. However, this interaction among plants, glyphosate, and soil microorganisms has only been studied in a number of crop plants, but not in weed species. This is surprising since the soil biotic environment has a strong impact on the activity of this important herbicide. …

Development Of Isotags For Nmr Based Metabolite Profiling And Applications, Fariba Tayyari

Open Access Dissertations

NMR spectroscopy is a powerful analytical tool for both qualitative and quantitative metabolite profiling analysis. However, accurate quantitative analysis of biological systems especially using one dimensional NMR has been challenging due to signal overlap. In contrast, the enhanced resolution and sensitivity offered by chemoselective isotope tags have enabled new and enhanced methods for detecting hundreds of quantifiable metabolites in biofluids using NMR spectroscopy or mass spectrometry. In this thesis we show improved sensitivity and resolution of NMR experiments imparted by 15N and 13C isotope tagging which enables the accurate analysis of plasma metabolites. To date, isotope tagging has been used …

Construction And Demonstration Of A Tandem Mass Spectrometer Based Instrument For Cold Ion Spectroscopy, James Gerhardt Redwine

Open Access Dissertations

A new instrument incorporating ion trap based tandem mass spectrometry and cold ion UV and UV-IR double resonance spectroscopy has been developed at Purdue University for the study of gas phase, biologically relevant ions. The instrument incorporates multiple quadrupole linear ion trap mass analyzers to prepare and isolate the precursor ions as well as to analyze the resultant photofragments. A 22-pole ion trap cooled to 5 K via a closed cycle helium cryostat is used to cool the ions for spectroscopic interrogation. Results show the vibrational and rotational temperature of a wide assortment of ions to be 12±2 K.

The …

Adaptive Targeting: Engaging Farmers To Assess Perceptions And Improve Watershed Modeling, Optimization, And Adoption Of Agricultural Conservation Practices, Margaret Mccahon Kalcic

Open Access Dissertations

Targeting agricultural conservation practices to farmland that has the greatest impact on surface water quality has received wide support from scientists and watershed managers. The targeting approach has, however, been politically contentious as many believe farmers will oppose the approach on grounds such as privacy invasion and unfair distribution of government incentives. Targeting conservation practices using complex optimization models has become common in the scientific community, and yet targeted results are underutilized in practice because of difficulties such as knowledge transfer and absence of a political framework for their use. For targeting to be successful, it must be politically supported …

Altered Cholesterol Metabolism In Human Cancers Unraveled By Label-Free Spectroscopic Imaging, Shuhua Yue

Open Access Dissertations

Despite tremendous scientific achievements, cancer remains the second leading cause of death in the United States. Metabolic reprogramming has been increasingly recognized as a core hallmark of cancer. My dissertation work identified novel diagnostic markers and therapeutic targets for human cancers through the study of cholesterol in cancer cells.

Enabled by label-free Raman spectromicroscopy, we performed the first quantitative analysis of lipogenesis at single cell level in human patient cancerous tissues. Our imaging data revealed an unexpected, aberrant accumulation of esterified cholesterol in lipid droplets of high-grade prostate cancer and metastases, but not in normal prostate, benign prostatic hyperplasia, or …

Nitrogen And Potassium Dynamics Of Selected Indiana Soils, Chun Zhao

Open Access Dissertations

Nitrogen (N) is the most limiting essential nutrient for crop growth. Numerous studies have been performed to improve N fertilizer recommendations. Accurate prediction of soil N supply has been found to be one of the most important factors that determine optimum fertilizer N rates. Seven soils collected from various locations across Indiana at four different depths were tested for N mineralization potential. Results showed that laboratory mineralizable N in the top layer (0-15 cm) of the seven soils ranged from 50 to 68 mg N kg-1 soil. In addition, more than 50% of the total mineralizable N was contributed from …

A Novel Fluid Structure Interaction And Thermal Model To Predict The Cylinder Block / Valve Plate Interface Performance In Swash Plate Type Axial Piston Machines, Marco Zecchi

Open Access Dissertations

The cylinder block / valve plate interface represents one of the most critical design element in the rotating kit of axial piston machines. The thin film of lubricant between cylinder block and valve plate has to fulfill simultaneously a bearing and a sealing function under dynamic load conditions; on the other hand, it represents an important source of power losses due to viscous friction and leakage flow.

An accurate prediction of the time changing characteristics of the interface, in terms of fluid film thickness, dynamic pressure field, load carrying ability and energy dissipation is necessary to generate more efficient and …

The City In Mind: Environmental Literacy And Adaptation In Nineteenth-Century British Literature, Adam Edward Watkins

Open Access Dissertations

This dissertation argues that a new paradigm of selfhood emerged in nineteenth-century British literature, one that recognized the individual will and environmental influence not as antithetical but as dialectical forces in the formation of the self. The concept of an externally negotiated subject challenges both the inward and socially determined conceptions of self that have dominated the relevant criticism. Informed by empiricist, associationist, and evolutionary theories of the mind, the portrayals of subject-formation in this study highlight the radical changes occurring in the human environment in nineteenth-century, which catalyzed the conception of a malleable yet self-forming subject. Along with the …

Genetic Engineering Of Black Cherry (Prunus Serotina) For Reproductive Sterility And Insect Pest Resistance, Ying Wang

Open Access Dissertations

Black cherry (Prunus serotina Ehrh.) is one of the most valuable hardwoods for high- end cabinetry, furniture, architectural millwork, paneling, and veneer. However, the damage caused by cambial-mining insect pests triggers gummosis in black cherry, a non-specific defense response in which resinous gum is deposited at the site of injury. The gum defects dramatically decrease the yield of high-quality black cherry lumber, and the value can be reduced by as much as 90%. The goal of this project was to optimize the transformation and in vitro rooting system, and to develop transgenic black cherry for reproductive sterility and insect pest …

Statistical Models For Gene And Transcripts Quantification And Identification Using Rna-Seq Technology, Han Wu

Open Access Dissertations

RNA-Seq has emerged as a powerful technique for transcriptome study. As much as the improved sensitivity and coverage, RNA-Seq also brings challenges for data analysis. The massive amount of sequence reads data, excessive variability, uncertainties, and bias and noises stemming from multiple sources all make the analysis of RAN-Seq data difficult. Despite much progress, RNA-Seq data analysis still has much room for improvement, especially on the quantification of gene and transcript expression levels. The quantification of gene expression level is a direct inference problem, whereas the quantification of the transcript expression level is an indirect problem, because the label of …

High-Pressure Vapor-Phase Catalytic Hydrodeoxygenation Of Lignin-Derived Compounds To Hydrocarbons On Bimetallic Catalysts In The Range Of 0.2-2.4 Mpa., Sara Lynn Yohe

Open Access Dissertations

Biomass, as the only renewable source of carbon, presents a sustainable alternative to liquid fossil fuels for the production of renewable transportation fuels and chemicals. The lignin portion of biomass poses a significant challenge in the upgrading and conversion of lignocellulosic biomass to fuels and chemicals, and in many current biorefineries is not utilized. However, the lignin fraction is a valuable feedstock due to its aromatic structure, lower O:C ratio than cellulose and hemicellulose, and high energy content (up to 40%) and weight fraction (average 25 wt%) of biomass. Several processes (including fast-pyrolysis, fast-hydropyrolysis, and liquid phase processing) are able …

Scholarly Collaboration In Engineering Education: From Big-Data Scientometrics To User-Centered Software Design, Hanjun Xian

Open Access Dissertations

Engineering education research has grown into a flourishing community with an-ever increasing number of publications and scholars. However, recent studies show that a significant amount of engineering education knowledge retains a clear disciplinary orientation. If the gaps in scholarly collaboration continue to be prevalent within the entire community, it will become increasingly difficult to sustain community memory. This will eventually inhibit the propagation of innovations and slow the movement of research findings into practice.

This dissertation studies scholarly collaboration in the engineering education research community. It provides a clear characterization of collaboration problems and proposes potential solutions. The dissertation is …

A Dynamic Magnetic Equivalent Circuit Model For Design And Control Of Wound Rotor Synchronous Machines, Xiaoqi Wang

Open Access Dissertations

Recently, a new magnetic equivalent circuit (MEC) model was developed to support automated multi-objective design of wound-rotor synchronous machines (WRSMs). In this research, the MEC model and its application have been enhanced. Initial enhancement has focused on using the MEC model to explore machine design and control as a unified problem. Excitation strategies for optimal steady-state performance have been developed. The optimization is implemented in two phases. First, stator and field excitation at rated power is obtained as part of a WRSM design in which the objectives are to minimize machine mass and loss. Second, a map between current and …

Biophysical Studies Of Cholesterol In Unsaturated Phospholipid Model Membranes, Justin Adam Williams

Open Access Dissertations

Cellular membranes contain a staggering diversity of lipids. The lipids are heterogeneously distributed to create regions, or domains, whose physical properties differ from the bulk membrane and play an essential role in modulating the function of resident proteins. Many basic questions pertaining to the formation of these lateral assemblies remain. This research employs model membranes of well-defined composition to focus on the potential role of polyunsaturated fatty acids (PUFAs) and their interaction with cholesterol (chol) in restructuring the membrane environment. Omega-3 (n-3) PUFAs are the main bioactive components of fish oil, whose consumption alleviates a variety of health problems by …

Synthesis Of Graphene Nanomaterials And Their Application In Electrochemical Energy Storage, Guoping Xiong

Open Access Dissertations

The need to store and use energy on diverse scales in a modern technological society necessitates the design of large and small energy systems, among which electrical energy storage systems such as batteries and capacitors have attracted much interest in the past several decades. Supercapacitors, also known as ultracapacitors, or electrochemical capacitors, with fast power delivery and long cycle life are complementing or even replacing batteries in many applications. The rapid development of miniaturized electronic devices has led to a growing need for rechargeable micro-power sources with high performance. Among different sources, electrochemical micro-capacitors or micro-supercapacitors provide higher power density …

Effects Of Dip-Coated Films On The Properties Of Implantable Intracortical Microelectrodes, Salah Sommakia

Open Access Dissertations

The successful clinical use of implantable intracortical microelectrodes (ICMs) to treat certain types of deafness, blindness, and paralysis is limited by a reactive tissue response (RTR) of the brain. This RTR culminates in the formation of a tight glial scar and a loss of neuronal density around implanted ICMs, and is accompanied by a decrease in signal to noise ratio and an increase in impedance. While no comprehensive mechanistic understanding of the underlying biology is currently agreed upon in the field, a general consensus exists around a highly volatile acute RTR phase. During this acute phase, the electrical properties of …

The Mechanism And Timescales Of Soil Formation In The Hyper-Arid Atacama Desert, Chile, Fan Wang

Open Access Dissertations

The planetary surfaces that evolve in the near absence of water are strikingly different from surfaces where water is abundant, but their formation is poorly documented. This research is an in-depth exemplary work in the Atacama Desert in northern Chile to understand the soil formation in hyper-arid environments, as an analog for planetary surfaces such as the Mars. In detail, the basic mechanism regarding the source material, timescale, paleo-climatic settings and the role of crypto-biotic crusts have been investigated to constrain the Atacama soil development.

The geochemical, isotopic and mineralogical composition of atmospheric dust deposited along a West-East transect in …

"I Have Thought Proper To Inform The World": Reading Unconventional Testaments Of 18th-Century New England Women, Elyssa Tardif

Open Access Dissertations

Early New England women chose to pass down what they owned and valued: clothing, cupboards, pewter dishes, commonplace books, etc. But some women passed down something more: a written testament, which sought to shape public opinion in colonial New England. A "testament" usefully suggests a text that both serves as a witness to lived experience as well as the means by which the individual herself can frame the narrative for those who come after. This project aims to examine not only written records but also their audience: who were the heirs to these testaments and how were the records preserved …

Utilization Of Biomass Derived Furans In Value-Added Organics And Heterogeneous Oxorhenium Catalysts For Deoxydehydration Of Diols, Benjamin L. Wegenhart

Open Access Dissertations

As fossil fuels are depleted, there is a growing focus on renewable chemicals based on biomass materials, including both fuels and chemical feedstocks. Current methods for biomass utilization include biological conversion to produce ethanol and various thermochemical routes (gasification, pyrolysis, liquefaction, hydrothermal treatment, etc.). Furfural is one particular chemical that can be obtained from lignocellulosic biomass in good yields through the dehydration of sugar residues. It can be used as a feedstock for chemicals such as furan and THF, or as a platform molecule for making liquid fuels. The objective of this research is to investigate new pathways for the …

Gas-Phase Covalent And Non-Covalent Ion/Ion Chemistry Of Biological Macromolecules, John Robert Stutzman

Open Access Dissertations

Gas-phase ion/ion chemistry involves the interaction of oppositely charged ions inside of the mass spectrometer. During this gas-phase chemistry, particle transfer (i.e., proton and electron) or synthesis can occur at rapid reaction rates. Particle transfer represents a mature area of ion/ion chemistry, while selective covalent modification represents a fairly new area of gas-phase chemistry. Gas-phase covalent chemistry is based on traditional solution phase organic chemistry.

The work demonstrated in this dissertation greatly involves gas-phase covalent and non-covalent Schiff base chemistry on peptide and protein ions. The reagent dianion, 4-formyl 1,3-benzene disulfonic acid, has been used to covalently modify unprotonated primary …

Effects Of Amur Honeysuckle (Lonicera Maackii [Rupr.] Herder) Invasion And Removal On Native Vegetation And White-Footed Mice (Peromyscus Leucopus) In Mixed-Hardwood Forests Of Indiana, Joshua Michael Shields

Open Access Dissertations

The threat of non-native invasive species continues to compromise the ecological and economic integrity of our natural resources. Numerous investigators have documented the negative effects of invasive species on native biota. However, much work is still needed with regard to how invasive species spread in space and time, factors contributing to impacts on native biota within invaded ecosystems, and resultant effects of removing invasive species. In terms of invasion patterns, few studies have documented local patterns and rates of woody plant invasions, and even less is known about changes in spatial patterning and factors influencing structural characteristics (diameter and height) …