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  1. Baculovirus Expression and Purification of Wild Type and Mutant Full-Length Human LRRK2

    Wang, Wen
    LRRK2 is a complex 285 kD protein in which the most prevailing mutations G2019S and R1441C are linked to autosomal dominant Parkinson disease (PD). This study has established an expression and purification system to produce active recombinant proteins of the LRRK2, to examine whether the mutations alter the LRRK2 activity and what mechanism underlies the alteration. Both bacterial and baculovirus expression systems were attempted to express and purify the proteins. The active full-length LRRK2 proteins (wild type, G2019S and R1441C) were obtained via the baculovirus system. The bacterial expression system was used for expression and purification of the LRRK2 kinase...

  2. A Computational Study of the Ignition of Premixed Methane and Oxygen via a Hot Stream

    Deans, Matthew Charles
    With methane being a fuel to be utilized in the future of space exploration, alternative ignition systems need to be developed. This study computationally focuses on the ignition of methane and oxygen mixtures in a counterflow configuration by a heated stream. Most combustion systems have non-uniform and/or non-homogenous flow, species, and temperature fields. This configuration allows for the study of both chemical kinetics as well as convective-diffusive transport effects. The effects of strain rate, pressure, and equivalence ratio on ignition are examined. A catalytic simulation code is used to generate ranges of combustion product composition and temperature when using a...

  3. The Role of Developmental Bias in a Simulated Evo-devo System

    Psujek, Sean Thomas
    The success of the Modern Synthesis has resulted in forces of evolutionary change other than natural selection being marginalized. However, recent work has attempted to show the importance of non-selective influences in shaping organic form. One such force is developmental bias, the differential produced of phenotypes. I use a simulation model of neural development to explore questions of general interest about developmental systems. From an analysis of the bias in the production of phenotypic variants in the developmental model, I find the pattern of developmental bias varies strongly with the genotype even among phenotypically-neutral genotypes. In addition to this genotype-dependent...

  4. The low cycle fatigue behavior of aluminum alloy based particulate composites

    Liu, Changqi
    MB85 (Al-3.5%Cu-2.4%Mg Alloy reinforced with SiC particulates) and 2014 (Al-4.2%Cu-1.5%Mg alloy reinforced with Al2O3 particulate) composites were heat-teated to underaged and overaged conditions followed by low cycle fatigue testing with total strain control. The results include three aspects: (i) Bauschinger effect and internal residual stress, (ii) Cyclic work hardening behavior, and (iii) Fatigue life and low cycle fatigue damage processes. X-ray diffraction techniques were used to measure the residual internal stress to compare with the Bauschinger measurements. SEM and TEM were used to characterize the microstructures before, during, and after the test. In light of a literature review on the...

  5. Modification and Cross-Linking of Proteins by Lipoxidation Derived Electrophiles: Chemical and Biological Consequences

    Lin, De
    Chemical modification of proteins and polynucleotides by electrophilic products of lipid oxidation, generated under condition of oxidative stress, have been implicated in a variety of diseases, such as atherosclerosis, neurodegenerative disease, liver disease, and cancer, to name a few. Most work has focused on reactive bifunctional aldehydes like malondialdehyde, 4-hydroxy-2-nonenal (HNE), 4-oxo-2-nonenal (ONE), and 4,5-epoxy-2-alkenals, in each case with an eye on modification and cross-linking of protein-based lysine, histidine, and cysteine residues. The reactions of HNE and ONE with two model proteins, RNase and β-lactoglobulin, and their Lys ε-dimethylamino derivatives, studied through spectrophotometry, showed that ONE was 6-31 times more reactive...

  6. Properties of Poly(ethylene glycol) Diacrylate Blends and Acoustically Focused Multilayered Biocomposites Developed for Tissue Engineering Applications

    Mazzoccoli, Jason Paul
    This research highlights the use poly(ethylene glycol) diacrylate (PEGDA) hydrogels for tissue engineering applications. PEGDA blends with molecular weights of 400 and 3400 were UV crosslinked to photoencapsulate mammalian cells at total polymer concentrations that were varied systematically from 20 to 40 wt %. Initial cell viability was determined via a fluorescent LIVE/DEAD assay and was reduced from 80 to 35% when increasing total polymer concentrations from 20 to 40 wt %. Hydrogels were produced with compressive moduli exceeding 1 MPa; however cell viability decreases as the modulus increases. These preliminary results can be exploited for cartilage tissue development to...

  7. MECHANISMS OF TRANSCRIPTIONAL REGULATION: GENE REPRESSION BY KRAB ZINC FINGER PROTEINS AND GENE INDUCTION BY ESTROGEN RECEPTOR beta

    Sripathy, Smitha P.
    DNA binding transcription factors are key players in the dynamic regulation of distinct gene expression programs, essential for maintenance of cell physiology and differentiation. Transcription factors either activate or repress transcription by sequence-selective binding to cis DNA elements and subsequent recruitment of distinct coregulator complexes. The KRAB zinc finger proteins (zfp) are DNA binding-dependent transcriptional repressors that are characterized by a conserved KRAB repressor domain at their N-terminus. Here we demonstrate that the multidomain protein KAP1 is an obligate corepressor of KRAB zfps. Mutational analysis of various KAP1 domains coupled with transient knockdown of the KAP1 interacting proteins, HP1 and...

  8. CHEMICAL SIGNAL ANALYSIS WITH FOURIER MICROFLUIDICS

    Yan, Xie
    Dynamic chemical signals are pervasive in biology. For example, chemical signals control biological processes in protein activation and signaling, paracrine and endocrine cell-to-cell communication, inflammatory response, and regulate many aspects of stem-cell growth and tissue differentiation. The time scales for many of these signals range from a fraction of a second to several minutes, depending on the specific system. In spite of their relevance, there are no well established techniques for analysis and separation of time-dependent signals. Conventional chemical analysis techniques such as electrophoresis and liquid chromatography can only be used for the analysis of finite, discrete and time invariant...

  9. Flame Spread and Extinction Over Solids in Buoyant and Forced Concurrent Flows: Model Computations and Comparison with Experiments

    Hsu, Sheng-Yen
    A detailed three-dimensional model for steady flame spread over thin solids in concurrent flows is used to compare with existing experiments in both buoyant and forced flows. This work includes (1) several improvements in the quantitatively predictive capability of the model, (2) a sensitivity study of flame spread rate on input parameters, (3) introduction of flame radiation into the buoyant-flow computations and (4) quantitative comparisons with two sets of buoyant upward spread experiments using cellulosic samples and a comparison with forced downwind spread tests using wider cellulosic samples. In additional to sample width and thickness, the model computation and experimental...

  10. Microwave response of high transition temperature superconducting thin films

    Miranda, Felix Antonio
    We have studied the microwave response of YBa2Cu3O7-δ, Bi-Sr-Ca-Cu-O, and Tl-Ba-Ca-Cu-O high transition temperature superconducting (HTS) thin films by performing power transmission measurements. These measurements were carried out in the temperature range of 300 to 20 K and at frequencies within the range of 30 to 40 GHz. Through these measurements we have determined the magnetic penetration depth (λ), the complex conductivity (σ* = σ1 - jσ2), and the surface resistance (Rs). An estimate of the intrinsic penetration depth (λ ∼ 121 nm) for the YBa2Cu3O7-δ HTS has been obtained from the film thickness dependence of λ. This value compares...

  11. Microcontroller-Based, Dual-Channel Wireless Neural Recorder/Stimulator

    Dorr, Christopher R.
    Two, dual-channel wireless neural recording and stimulation devices are presented. The basic version has a neural preamplifier in series with a second amplifier to provide a signal gain of 4000. A multiplexer selects the recording channel. An 8-bit ADC converts the analog neural data into a digital stream, which is Manchester-encoded and frequency-shift-key (FSK) modulated at 27.12 MHz, before being transmitted to the host transceiver. The device receives 125-kHz on-off-keyed (OOK) commands, allowing the user to change record channels, program stimulation parameters, and trigger stimulus. The electrical performance of the basic version has been measured and compared to theoretical results. In...

  12. Does the Market Know? Evidence from Managerial (Non-) Reporting of Financial Stealth Restatements

    Hogan, Brian
    This dissertation expands upon the investor and restatement literatures by examining the market impact, if any, of stealth restatements by firms. Stealth restatements occur when firms restate prior periods without both amending the past affected reports and filing a Form 8-K Item 4.02, disclosing the restatement as mandated by the Securities and Exchange Commission (SEC). Utilizing a disclosure level index for firm restatement reporting, I find that abnormal returns are significantly negative over short and longer term time frames for firms with Form 8-K (high disclosure) negative large and small impact restatements. These results are similar to other abnormal return...

  13. Biomarkers for Age-Related Macular Degeneration

    Gu, Jiayin
    The goal of this thesis research was to develop methods to predict susceptibility to age-related macular degeneration (AMD). AMD is the most common cause of legal blindness in the elderly in developed countries, and early identification of susceptibility is important for preventing this progressive disease. In the thesis, new evidence supporting the prognostic potential of plasma carboxyethylpyrrole (CEP) oxidative protein modifications and CEP autoantibodies as biomarkers for AMD is presented. CEP adducts and autoantibodies were quantified by ELISA from 916 AMD and 488 control donors and mean levels were found to be elevated in AMD plasma by ~60% and ~30%,...

  14. The Effect of Methionine-35 Oxidation and PvY Antibody Binding on the Aggregation of the Aβ Peptide of Alzheimer's Disease

    Tedesco, Johnathan Martin
    Alzheimer's disease (AD) is characterized by the aggregation and extracellular deposition of the Aβ(1-40) and Aβ(1-42) peptides as amyloid plaques. Numerous studies suggest that the Aβ pathologic effects are related to the conversion of monomeric, random structured Aβ into aggregated β-sheet structures that eventually form plaques. This thesis focuses on two projects that are involved with inhibition of the Aβ aggregation and plaque formation processes. The first project compared the methionine-35 (Met35)oxidation rates of the Aβ(1-40) and Aβ(1-42) peptides. Previous work demonstrated that oxidation of the Met35 side-chain to the sulfoxide (Met35red to Met35ox) impedes aggregation and formation of amyloid protofibrils....

  15. A New Algorithm for Efficient Software Implementation of Reed-Solomon Encoders for Wireless Sensor Networks

    Emelko, Glenn A.
    With the recent introduction and development of ad-hoc wireless sensor networks, and other miniature or low-power communications systems, high performance at a low cost is a key critical factor. Reliable data transmission from these wireless sensors is necessary, especially if the sensor end-points are transmit-only type devices. Error correction codes may be used to improve reliability of the transmission, in many instances improving the operating margin by 6dB or more (depending on the correcting power of the code). Presented is an algorithm for highly efficient, compact Reed-Solomon error correction encoder, realized entirely in software. This improved encoding algorithm takes between...

  16. Impaired Balance of Mitochondria Fission and Fusion in Alzheimer Disease

    Wang, Xinglong
    Alzheimer's disease (AD) is the leading cause of dementia in the elderly, characterized by neurofibrillary tangles, senile plaques and a progressive loss of neuronal cells in selective brain regions. Mitochondrial dysfunction is a prominent and early feature of the disease, although the reason for this is unclear. Nonetheless, emerging evidence suggest that mitochondrial function is dependent on the dynamic balance of fission and fusion events which are regulated by mitochondria fission and fusion proteins (i.e. DLP1/OPA1/Mfn1/Mfn2/Fis1). While an impaired balance of mitochondria fission and fusion is being increasingly implicated in neurodegenerative diseases, few studies have examined this aspect in AD....

  17. The Conceptual Adequacy of the Drug Attitude Inventory For Measuring Youth Attitudes Toward Psychotropic Medications: A Mixed Methods Evaluation

    Townsend, Lisa Dawn
    Despite the effectiveness of psychotropic treatment in alleviating symptoms of some psychiatric disorders, youth adherence to these medication regimens is low. However, little is known about youth attitudes toward psychiatric medications or about their subjective experiences of treatment. Gathering information about these attitudes and treatment experiences may shed light on adolescents’ low adherence to psychiatric medications. The purpose of this mixed methods study was to answer the following questions: 1) What is the factor structure, validity, and reliability of the Drug Attitude Inventory (DAI) in youth undergoing psychotropic treatment? (quantitative question); 2) Will qualitative interviews with adolescents about their daily use...

  18. Investigations Into the Mechanisms of Vitamin C Uptake in Rodent and Human Lens Epithelial Cells

    Obrenovich, Mark E.
    Vitamin C, Ascorbic Acid (ASA), was first isolated in 1928 by the Hungarian biochemist and Nobel Prize winner Albert Szent-Gyorgyi. Szent-Gyorgi described this compound, as a carbohydrate derivative Hexouric acid. ASA is a water-soluble antioxidant, somewhat unstable organic acid that is easily oxidized and destroyed when in aqueous solutions, and when dry, by oxygen or alkali and high temperature conditions. In the reduced state, ASA is an essential nutrient, cofactor and antioxidant. Now, new evidence comes from carbohydrate research, which has focused largely on nonenzymatic glycation as a type of carbonyl stress in animals, first ascribed to glucose, which implicates...

  19. Influences On School-Age Children’s Milk And Soft Drink Intake

    Balian, Arax
    Over the past decades milk intake among 6-to11-year-olds declined 24% among boys and 32% among girls. Concomitantly, consumption of calorie and carbohydrate-rich soft drinks doubled, raising concerns related to overweight. Prevalence of childhood overweight has more than tripled since 1976 leading to serious health conditions. A cross-sectional descriptive correlational study was undertaken using the Theory of Planned Behavior. The purposes were to: (1) determine influences on school-age children’s milk and soft drink intake and (2) determine the effect of gender, ethnicity, and body mass index (BMI) on behavioral beliefs, normative beliefs, control beliefs, attitude, subjective norm, perceived behavioral control, intention,...

  20. Interface Electronics for Peripheral Nerve Recording and Signal Processing

    Limnuson, Kanokwan
    Interface electronics for peripheral nerve recording and analog signal processing is developed in this work as part of sensing mechanism for a laryngeal pacemaker to reanimate the paralyzed larynx in subjects with bilateral vocal fold paralysis. The electronic system has been designed to record neural activity from the phrenic nerve, condition the neural signal, and provide activity-dependent triggering for stimulator control. The system has been implemented in discrete fashion with commercial off-the-shelf components as well as integrated on a single 2.2 × 2.2-mm^2 chip fabricated using the AMI 1.5 μm 2P/2M n-well CMOS process. System architecture, circuit design and analysis,...

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