Digital Commons Network^™

Cell Phone Use And Psychosocial Development Among Emerging Adults, Torrey B. Morrill

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The cell phone has rapidly become an integral, and, for some, an essential communication tool that is being used worldwide. With cell phone ownership becoming so widespread, especially among the younger generation, society is starting to see and question the impacts of cell phone use on adolescent development.

Relations between cell phone possession, cell phone use, and psychosocial and identity development were investigated using Erikson's Psychosocial Theory and Marcia's Adolescent Identity Paradigm. A sample of 705 college students, ages 18-24, completed a questionnaire that measured the amount and type of cell phone use, identity development (Extended Objective Measure of Ego …

The Role Of Reactive Oxygen Species In Oxidative-Induced Neoplastic Transformation, Daniel J. Puleston

The Plymouth Student Scientist

The generation of reactive oxygen species (ROS) is a normal occurrence in the life of a cell. ROS are derived from both exogenous and endogenous sources and take part in a plethora of normal physiological mechanisms from host immunity to cell cycle regulation. However, ROS also exhibit a deleterious, disruptive character that means they must now be taken seriously as a genuine carcinogenic agent able to alter a variety of pathways leading to the initiation of cancer. The two-sidedness of ROS means that the relationship between ROS and the onset and progression of cancer is hard to determine. ROS and …

Nitric Oxide And The Immune System: A Literature Review, Hannah Hosking

The Plymouth Student Scientist

Nitric oxide (NO) was discovered as a biologically active molecule over two decades ago and it has since been recognised as one of the most versatile components of the immune system, with involvement in both cytotoxic and regulatory functions. It is a readily diffusible gas that has been established as a universal messenger, capable of mediating cell-cell communication throughout the body. It is involved in the pathogenesis and also the control of infectious diseases, autoimmunity, chronic degenerative diseases and tumours. This review will collate, contrast and compare recently published literature, to provide an up-to-date and contemporary overview of the substantial …

Effects Of Non-Equilibrium Plasma On Eukaryotic Cells (Final Report: Grant Fa9550-06-1-0004), Mounir Laroussi, Fred C. Dobbs, Old Dominion University

Electrical & Computer Engineering Faculty Publications

This document is our final report describing the research activities carried out under AFOSR Grant FA9550-06-1-0004. First, descriptions of our cold plasma generation systems are presented. Two systems, developed with past and present AFOSR support, are available in our laboratory. The first is a pulsed device capable of emitting a cold plasma plume in room air. The second is an air plasma generator the core of which is a dielectric barrier discharge excited by a high AC voltage. Following these brief descriptions we first present the effects of an atmospheric pressure air plasma on four different types of eukaryotic microalgae. …

Engineering The Optical Properties Of Gold Nanostructures For Biomedical Applications, Leslie Au

All Theses and Dissertations (ETDs)

This research investigated the synthesis and optical properties of Au nanostructures with an aim to use them as imaging agents and photothermal transducers for the diagnosis and treatment of cancer. I have produced Au nanocages with hollow interiors and porous walls using the galvanic replacement reaction between Ag nanocubes and AuCl₄-. I have engineered these Au nanocages to have localized surface plasmon resonance: LSPR) peaks in the near-infrared region with strong absorption. These optical properties allow for the imaging of biological tissues at deeper penetration and the photoablation of cancer. By replacing AuCl₄- with AuCl_{2 …}

Genetic Over-Expression Of Cytokeratin 18 In Bovine Luteal Cells: Effects On Intermediate Filament Formation And Fas Ligand-Induced Apoptosis, Jennifer J. Forcina

Master's Theses and Capstones

The receptor Fas and its ligand, FasL, are implicated in apoptosis of luteal cells during regression of the corpus luteum (CL). In some cell types, cytokeratin (CK) 8/18 filaments impair FasL-induced apoptosis. Here, we determined if genetic over-expression of CK18 filaments in luteal cells similarly prevents FasL-induced apoptosis. Luteal cell cultures were prepared from early and late stage bovine CL (day 5 and days 16-18 post-ovulation, respectively). The cells were transduced with media, mock vector containing GFP, or a CK18-containing vector, and then exposed to a cytokine cocktail containing FasL for 24 hours. Transduction of luteal cells with CK18 vector …

The Cd-Loop Of Pai-2 (Serpinb2) Is Redundant In The Targeting, Inhibition And Clearance Of Cell Surface Upa Activity, Blake J. Cochran, Lakshitha P. Gunawardhana, Kara L. Perrow, Jodi A. Lee, Sergei A. Lobov, Marie Ranson

Faculty of Science - Papers (Archive)

Background: Plasminogen activator inhibitor type-2 (PAI-2, SERPINB2) is an irreversible, specific inhibitor of the urokinase plasminogen activator (uPA). Since overexpression of uPA at the surface of cancer cells is linked to malignancy, targeting of uPA by exogenous recombinant PAI-2 has been proposed as the basis of potential cancer therapies. To this end, reproducible yields of high purity protein that maintains this targeting ability is required. Herein we validate the use in vitro of recombinant 6 × His-tagged-PAI-2 lacking the intrahelical loop between C and D alpha-helices (PAI- 2 ΔCD-loop) for these purposes.

Results: We show that PAI-2 ΔCD-loop …

A Spectroscopic And Dft Study Of Thiophene-Substituted Metalloporphyrins As Dye-Sensitized Solar Cell Dyes, Sanjeev Gambhir, Keith C. Gordon, David L. Officer, Samual J. Lind

Faculty of Science - Papers (Archive)

A combination of density functional theory calculations, electronic absorption and resonance Raman spectroscopy has been applied to a series of beta-substituted zinc porphyrins to elucidate how the substituent affects the electronic structure of the metalloporphyrin and assign the nature of electronic transitions in the visible region. The use of conjugated beta substituents invokes a large perturbation to both the nature and energy of the frontier molecular orbitals and results in the generation of additional molecular orbitals from the parent metalloporphyrin species. A complicated electronic absorption spectra is observed which can be rationalised by an extension of Goutermans' four-orbital model. The …

Glutarate And N-Acetyl-L-Glutamate Buffers For Cell-Free Synthesis Of Selectively 15n-Labelled Proteins, X Jia, Kiyoshi Ozawa, K Loscha, G Otting

Faculty of Science - Papers (Archive)

Cell-free protein synthesis provides rapid and economical access to selectively 15N-labelled proteins, greatly facilitating the assignment of 15N-HSQC spectra. While the best yields are usually obtained with buffers containing high concentrations of potassium L-glutamate, preparation of selectively 15N-Glu labelled samples requires non-standard conditions. Among many compounds tested to replace the L-Glu buffer, potassium N-acetyl-L-glutamate and potassium glutarate were found to perform best, delivering high yields for all proteins tested, with preserved selectivity of 15N-Glu labelling. Assessment of amino-transferase activity by combinatorial 15N-labelling revealed that glutarate and N-acetyl-L-glutamate suppress the transfer of the 15N-alpha-amino groups between amino acids less well than …

In Vivo Function Of Otopetrin 1 In The Vestibular Sensory Epithelium, Euysoo Kim

All Theses and Dissertations (ETDs)

Otopetrin family genes encode multi-transmembrane domain proteins with three highly conserved domains. In mice, three Otopetrin paralogues are found. One of its members, Otopetrin 1: Otop1) has been previously shown to be essential for the formation of otoconia in the vestibular system of the inner ear. Otoconia are calcium carbonate biominerals that are required for normal balance and the sensation of linear acceleration with respect to gravity. The mechanism by which OTOP1 mediates otoconia biosynthesis is not known, but the ability of OTOP1 to modulate [Ca2+]i in response to purinergic signals in heterologous systems suggest that OTOP1 may be involved …

Flap Endonuclease 1 Ensures Telomere Replication And Stability, Abhishek Saharia

All Theses and Dissertations (ETDs)

Telomeres, protein-DNA structures that distinguish the end of a chromosome from a bona fide DNA double strand break, are integral to genomic stability. High fidelity replication of telomeres is indispensable for their stability. Telomere replication is a challenging task that is completed through the coordinated actions of telomere binding proteins and DNA replication and repair proteins in ways that are not well understood. This work focuses on delineating the function of one DNA replication and repair protein, Flap Endonulcease 1: FEN1), in telomere replication and maintenance. I demonstrate that FEN1 is essential for the efficient replication of telomeres through its …

Role And Regulation Of Escrt-Iii In Multivesiculr Body Biogenesis, Soomin Shim

All Theses and Dissertations (ETDs)

Endosomal sorting complex required for transports: ESCRT) machinery responsible for multivesicular body: MVB) biogenesis is essential for receptor downregulation, viral budding and cytokinesis. ESCRT-III is a large polymer built from related ESCRT-III proteins that is thought to help generate intralumenal vesicles: ILVs) within the MVB. How ESCRT-III functions is poorly understood. Although ESCRT-III assembles on the endosomal membrane, its components are predominantly soluble in the cytoplasm. I found that the transition between these two states is controlled by autoinhibitory domains within ESCRT-III proteins, which I identified by structure/ function analysis in four human ESCRT-III proteins - Charged multivesicular body protein2A: …

Systemic Levels Of G-Csf And Il-6 Determine The Angiogenic Potential Of Bone Marrow Resident Monocytes, Alyssa Gregory

All Theses and Dissertations (ETDs)

Recent studies have demonstrated the efficacy of hematopoietic cell-based therapies in promoting therapeutic angiogenesis for a wide variety of vascular syndromes, however the cell populations responsible and the mechanisms involved are poorly understood. Using a mouse model of hindlimb ischemia, we previously showed that an adoptive transfer of donor monocytes significantly enhanced revascularization. Monocytes are a widely heterogeneous cell population and differences in the ability of various monocyte subsets to mediate revascularization have not been previously investigated. Using the hindlimb ischemia model we demonstrate that an adoptive transfer of inflammatory: CX3CR loGr-1+), but not resident: CX3CR1hiGr-1-) monocytes, significantly enhances revascularization …

Coordinate Interstitial Deletions Of Retinoblastoma (Rb1) And Neurobeachin (Nbea) Genes On Chromosome 13 In Mgus And Multiple Myeloma, Julie O'Neal

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Coordinate interstitial deletions of Retinoblastoma: RB1) and Neurobeachin: NBEA) genes on chromosome 13 in monoclonal gammopathy of undetermined significance: MGUS) and multiple myeloma By Julie O'Neal Doctor of Philosophy in Biology and Biomedical Sciences: Molecular and Cellular Biology) Washington University in Saint Louis, 2009 Assistant Professor Michael H. Tomasson, Chair Numeric or structural chromosomal abnormalities are detected in nearly all patients with plasma cell dyscrasias, including primary amyloidosis, monoclonal gammopathy of undetermined significance: MGUS) and multiple myeloma: MM). Chromosome 13 deletions, most frequently monosomy 13, are detected in 10- 20% of MM cases by routine cytogenetics …

A Phenotypic And Genetic Characterization Of The Cell Adhesion Molecules Echinoid And Friend-Of-Echinoid In The Directed Cell Movements Of Ommatidial Rotation During Drosophila Eye Development., Jennifer Fetting

All Theses and Dissertations (ETDs)

Correct development of multicellular organisms relies on the precise patterning of cells, which must respond to and interpret specific cues that instruct the cells to differentiate and often undergo directed cell movements and rearrangements to give rise to functional tissues and organs. Differential adhesion between the stationary and mobile cells permits and promotes these cellular movements, effecting patterning of cells and tissues. During Drosophila eye development, groups of cells, the ommatidial precursors, undergo a 90° rotational movement within a matrix of stationary cells, providing the cell motility readout of tissue polarity. The mechanisms that regulate ommatidial rotation are not well …

Aggregation & Localization Of A Disease-Associated Prion Protein (Prp) Mutant, Andrea Rhonda Medrano

All Theses and Dissertations (ETDs)

ABSTRACT OF THE DISSERTATION Aggregation & Localization of a Disease-Associated Prion Protein: PrP) Mutant by Andrea Rhonda Zaragoza Medrano Doctor of Philosophy in Biology and Biomedical Sciences: Genetics) Washington University in St. Louis, 2009 Professor David A. Harris, Chairperson Prion protein: PrP) is a GPI-anchored sialoglycoprotein involved in the pathogenesis of infectious and inherited forms of transmissible spongiform encephalopathies: TSEs). A nine-octapeptide insertional mutation in the prion protein: PrP) causes a fatal neurodegenerative disorder in both humans and transgenic mice. To determine the precise cellular localization of this mutant PrP: designated PG14), we have generated transgenic mice expressing PG14-EGFP, a …

Characterization Of Ligand-Induced Conformational Changes In The Egf Receptor, Katherine Yang

All Theses and Dissertations (ETDs)

ABSTRACT OF DISSERTATION Characterization of ligand-induced conformational changes in the EGF receptor by Katherine S. Yang Doctor of Philosophy in Biochemistry Washington University in St. Louis, 2009 Professor Linda Pike, Chairperson The epidermal growth factor: EGF) receptor is a classical receptor tyrosine kinase that mediates cellular processes such as proliferation, migration, and differentiation in response to growth factor stimulation. Crystal structures of the EGF receptor suggest that its activation is associated with extensive conformational changes in both the extracellular and intracellular domains. However, evidence of these structural dynamics in intact cells has been lacking. This thesis describes the characterization of …

Targeting The Dimerization Of Erbb Receptor Tyrosine Kinases, Rob Yang

All Theses and Dissertations (ETDs)

The epidermal growth factor receptor: EGFR) is a membrane receptor tyrosine kinase whose over-activation has been implicated to cause many human cancers. Novel strategies to inhibit the activation of EGF receptors other than the conventional antibody-based and tyrosine kinase inhibitors are virtually non-existent but could provide benefits both in the laboratory and clinical settings. In an effort to expand the current approaches, this thesis focused on targeting the homodimerization of the EGF receptors themselves and the heterodimerization of EGF receptors with the related ErbB2 receptor. Three sub-projects were completed in the process. The first project explored the feasibility of inhibiting …

Regulation Of Bax/Bak-Dependent Cell Death Program, Hyungjin Kim

All Theses and Dissertations (ETDs)

Mammals have evolved an intricate regulation of a genetically programmed apoptotic cell death that involves mitochondria. Diverse apoptotic signals converge on mitochondria, which causes the release of cytochrome c into the cytosol to activate Apaf-1. This initiates caspase activation, which results in irreversible cellular demise. The BCL-2 family proteins constitute a critical checkpoint in mitochondrion-dependent apoptosis. Multidomain proapoptotic BAX/BAK promotes mitochondrial outer membrane permeabilization, whereas anti-apoptotic BCL-2/BCL-X_L/MCL-1 protects mitochondrial integrity and prevents cytochrome c release. The proapoptotic activity of BAX/BAK is triggered by BH3-only molecules: BH3s) which are upregulated by upstream death signals. However, how these subfamilies interact …

Runx1 In Primitive Hematopoiesis And Characterization Of Hematopoietic Stem Cells In A Mouse Chronic Inflammatory Arthritis Model, Yunglin Ma

All Theses and Dissertations (ETDs)

Hematopoietic cells are essential for growth and survival throughout adult life. Two different aspects of hematopoiesis are addressed in this dissertation. I. The regulation of primitive hematopoiesis by Runx1 and TGF-beta signaling. Primitive hematopoiesis, occurring exclusively in the yolk sac, is characterized by its transient nature. As the primitive hematopoiesis declines in the yolk sac, definitive hematopoietic progenitors generated in the yolk sac and/or embryo take over in blood cell production. Whether the transition from primitive to definitive hematopoietic program reflects a mere shift in hematopoietic sites or whether it is an actively regulated process is currently unknown. Runx1 is …

Calling Cards For Dna-Binding Proteins, Haoyi Wang

All Theses and Dissertations (ETDs)

Organisms respond to their environment by altering patterns of gene expression. This process is orchestrated by transcription factors, which bind to specific DNA sequences near genes. In order to understand the regulatory networks that control transcription, the genomic targets of all transcription factors under various conditions and in different cell types must be identified. This remains a distant goal, mainly due to the lack of a high-throughput, in vivo method to study protein-DNA interactions. To fill this gap, I developed transposon "Calling Cards" for DNA-binding proteins. I endowed DNA binding proteins with the ability to direct the insertion of a …

Hiv-1 Envelope-Induced Signaling Mediates Actin Cytoskeleton Rearrangements Necessary For Fusion And Entry, Brooke Harmon

All Theses and Dissertations (ETDs)

Human immunodeficiency virus type-1: HIV-1) initiates infection by direct fusion of the virus membrane with the plasma membrane of the target cell. This fusion event is a multi-step process mediated by the envelope: Env) surface subunit gp120 and the transmembrane subunit gp41 which anchors gp120 into the viral membrane. First the surface subunit gp120 binds to the primary receptor CD4. This interaction promotes actin cytoskeletal rearrangements in the target membrane that bring the chemokine coreceptor, CCR5 or CXCR4, into close proximity for binding and induces conformational changes in gp120 that allow it to couple to the coreceptor. Formation of the …

Hybrid Fuel Cell And Energy Storage Systems Using Superconducting Coil Or Batteries For Clean Electricity Generation, Danny Soetanto, Kai Ding

Faculty of Engineering - Papers (Archive)

This paper described a novel design of a hybrid fuel cell and energy storage system using high temperature superconducting energy storage system (HT-SMES) or batteries to meet fast changing load. The power electronic switches in the converter of the energy storage system are controlled in such a way that the amplitude and waveform of the inverter output current from the fuel cell is tightly regulated to follow a sinusoidal reference waveform. In this way, the energy storage system is used to supply the fast changing part of the load and the fuel cell system continuously supplies a constant full load …

Regulation Of Polyamine Metabolism In Transgenic Poplar Cell Cultures, Smita Cherry

Master's Theses and Capstones

Polyamines (PA) are naturally occurring low molecular weight aliphatic amines found in all living organisms and essential for their growth and development. The present study uses the tool of transgenic manipulation to elucidate the regulation of PA pathway in poplar cells. This study was divided into two segments; the first segment provides insight into biochemistry of a putrescine overproducing cell line (HP) that overexpresses a mouse ornithine decarboxylase (mODC) under 35S-CaMV promoter, with respect to different treatments. The second segment focused on creation and biochemical characterization of a cell line (SOS1) that overexpresses ODC/SAMDC from Plasmodium falciparum controlled by the …

Disruption Of Cytokeratin 18-Containing Intermediate Filaments In Bovine Luteal Cells: Effects On Fas Expression, Progesterone Secretion, And Fasl-Induced Apoptosis, Alice Duncan

Master's Theses and Capstones

In the current study, the possibility that cytokeratin 18 (CK18)---containing intermediate filaments (IFs) protect bovine luteal cells from FasL-induced apoptosis was explored. Bovine corpora lutea (CL) from early and late stages of the luteal phase were collected and prepared for cell culture. The cultures were exposed to culture medium without (control) or with 5mM acrylamide for 4 hr to disrupt CK18 IFs. Subsequently, the cultures were exposed to fresh medium without (control) or with FasL (50ng/mL) for 24 hr to induce apoptosis. Acrylamide disrupted CK18 IFs without affecting microtubules, progesterone secretion (P>0.05), or cell viability (P>0.05). Surface expression …