Digital Commons Network^™

Accuracy Of Volumetric Analysis Software Packages In Assessment Of Tooth Volume Using Cbct, Saylee Nimbalkar

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to evaluate the accuracy of volumetric analysis software packages in assessment of tooth volume using cone beam computed tomography and compare them to the volume obtained using an optical digital scanner. Twenty-four single rooted teeth indicated for extraction were collected. Cone beam computed tomography scans of these teeth resting in a custom scan jig were taken. Three dimensional digital models were obtained from the DICOM image cone beam computed tomography files using segmentation software packages (Anatomage, Mimics, and Amira) and volumes were calculated for each of the segmented teeth. The teeth were then scanned …

Sedimentology Of Kingston Peak Formation Kp1 Beds In Beck Canyon Region, Kingston Range, California, Dominic Joel Ombati

Loma Linda University Electronic Theses, Dissertations & Projects

The Neoproterozoic Kingston Peak Formation (KPF) is known for its diamictites interpreted as of glacial origin. The KPF overlies the Beck Spring Dolomite (BSD) that contains microfossils and microbialites. This study aims to test correlation between outcrops and understand the abrupt change from BSD to KPF. It focuses on the basal 4 meters of the KP1 subunit of the KPF as it appears in the Beck Canyon region, Kingston Range, California. We describe and correlate sedimentary rocks at and immediately overlying the contact and analyze the sedimentary structures, textures and sequences. We have found only three sites in the northern …

Factors Promoting Human Papillomavirus Mediated Cervical Carcinogenesis, Yan Chen Wongworawat

Loma Linda University Electronic Theses, Dissertations & Projects

High-risk human papillomavirus (HPV) is the causative agent of cervical cancer. Integration of the HPV genome into the host genome is a key event in cervical carcinogenesis, with oxidative stress (OS) likely playing a major role in promoting DNA damage, and subsequently, integration. In our current study, we demonstrated a chain of events leading from the induction of OS, to DNA damage, and then to viral integration. Induction of OS by either virus-mediated factors, such as expression of E6*, a splice variant of the E6 oncogene, or by exogenous factors led to DNA damage in normal oral keratinocytes and in …

Exploring Factors In The Relationship Balance Assessment, Thomas B. Luttrell

Loma Linda University Electronic Theses, Dissertations & Projects

While studies have highlighted the role of gendered power in relationships, many assumptions have not been quantitatively tested due to a lack of measures for power. This study uses exploratory factor analysis to construct a dyadic assessment of relative power and equality in relationships. This assessment would be useful for research and for clinical work with couples to help raise awareness of the balance of power in their relationship. Equality is defined as a mutual process in which both partners demonstrate that they hold equal value in the relationship, whereas inequality is when there is a relative imbalance of value …

Influence Of Low Temperature Degradation On Microstructural Integrity Of Zirconia Dental Implants, Mona Monzavi Rahimi

Loma Linda University Electronic Theses, Dissertations & Projects

Zirconia dental implants have become more popular in the field of implant dentistry. However, concerns have been raised regarding low temperature degradation and its influence on phase stability and micro-structural integrity in terms of increased micro-crack formation. In the case of dental implants, this could possibly result in delamination and interference with bone to implant contact and eventually lead to loss of integration and failure. Nevertheless, no study has reported the effects on commercially available Zirconia dental implants. The primary aims of this study was to determine if there is a correlation between ageing duration and 1) depth of tetragonal-monoclinic …

Role Of Protein Kinase G In Regulating Vascular Tone In Hypoxic Ovine Cerebral Arteries, Richard Burdette Thorpe

Loma Linda University Electronic Theses, Dissertations & Projects

Nitric oxide (NO) and its precursors have been used clinically to induce vasorelaxation long before the specific mechanism of how this operates was understood. With the discovery in 1977 of the influence of NO on guanylate cyclase, and the subsequent elucidation of the NO pathway, the role of cyclic guanidine monophosphate (cGMP)-dependent protein kinase (PKG) has been shown to be the main mediator of NO-induced vasorelaxation. Less well understood is the behavior of this pathway in conditions of long term hypoxia (LTH). It was later shown that LTH attenuates the ability of PKG to mediate vasorelaxation. How this operates is …

Effects Of Neonatal Dexamethasone On The Maturation And Endowment Of Cardiomyocytes, Maresha Gay

Loma Linda University Electronic Theses, Dissertations & Projects

Each year 1 in 9 infants are born preterm in the United States. Preterm infants have a host of complications associated with prematurity, including respiratory distress syndrome. Dexamethasone, a synthetic glucocorticoid is the ‘gold standard’ intervention in the treatment of preterm infants and mothers at risk of preterm birth because it promotes organ maturation, particularly the lungs and aids in surfactant production. However, a growing body of evidence suggests perinatal dexamethasone exposure is associated with health consequences later in life including increased risk of cardiovascular disease. Cardiomyocytes are the functional unit of the heart and are unique in that they …

Factors Influencing Blood Pressure Among Rural Adults With Hypertension In China, Lili Yang

Loma Linda University Electronic Theses, Dissertations & Projects

The low rate of hypertension control in China has caught the attention of health providers. To achieve better outcomes, providers need to know what factors are significantly predictive of hypertension control. Researchers have rarely studied illness perception in China although it is one of the predictors for illness outcomes often studied in other countries. The purpose of this study was to examine the relationship among demographic and health-related characteristics, illness perception, adherence to medication and to self-management, and blood pressure in a sample of rural adults with hypertension in the Zhejiang Province of China. Leventhal’s Self-Regulation Model guided this cross-sectional, …

Experiences Of Nurses And Midwives During The Ebola Outbreak In Liberia, West Africa, Erhuvwukorotu S. Kollie

Loma Linda University Electronic Theses, Dissertations & Projects

The 2014 – 2015 Ebola outbreak in the West African region resulted in many deaths and has been responsible for devastating health and socioeconomic upheaval. The decision of nurses and midwives whether or not to render care during outbreaks is vital for the containment of the disease. The purpose of this study was to explore the experiences of nurses and midwives during the Ebola outbreak in Liberia. A grounded theory method based on Corbin and Strauss (2015) and Charmaz (2014) was used, resulting in a conceptual model describing the process involved in the work decisions made by the study participants. …

Emotional Memory: Examining Differences In Retrieval Methods, Audrey Martinez

Loma Linda University Electronic Theses, Dissertations & Projects

Emotional information is generally remembered better than non-emotional information, especially when the emotional information is highly arousing. Priority Binding Theory has grown out of several years worth of research on memory and emotion. The theory proposes that in mixed lists comprised of negative and arousing words and neutral words, negative and arousing words will take priority during mental processing resulting in stronger encoding for the emotional words relative to neutral words with no such effect predicted for pure lists. Our lab made several attempts to extend the theory to picture stimuli, but were unsuccessful. However, the predictions of Priority Binding …

The Frontal-Temporal Signature Of Tbi-Induced Acute Cerebral Metabolic Crisis, Christina Mannino

Loma Linda University Electronic Theses, Dissertations & Projects

Traumatic brain injury (TBI) often leads to acute cerebral metabolic crisis (ACMC), which appears to have the greatest impact on the frontal-temporal regions. A recent study demonstrated that atrophy in the frontal and temporal lobes related to acute metabolic crisis due to moderate or severe TBI was associated with poorer attention, executive functioning, and psychomotor abilities at 12 months post-injury. In addition, participants with greater frontal-temporal atrophy had T-scores on all of the standard tests that were in the deficit range indicating deficits in cognition. The purpose of the current study is to investigate the ability of direct measures of …

General Fatalism And Diabetes Fatalism As Predictors Of Diabetes Treatment Adherence, Esmeralda Ibette Nuñez

Loma Linda University Electronic Theses, Dissertations & Projects

Greater conceptual distinction between fatalism as a cultural value orientation (general fatalism) and disease-specific fatalism is necessary to evaluate fatalism as a predictor of health behaviors such as diabetes treatment adherence. We tested an integrated, theory-driven structural model of relationships among income, education, age, gender, general fatalism, diabetes fatalism, and type 2 diabetes treatment adherence, as measured by hemoglobin a1c levels (hba1c), in a sample of mainstream-Chileans (n=229) and indigenous people of Chile known as the Mapuche (n=134). Hypotheses were that higher income and education would predict more general fatalism and diabetes fatalism across ethnic groups and higher general fatalism …

Mechanism Of Chimeric Vaccine Mediated Immune Suppression Of Human Dendritic Cells, Jacques Christian Mbongue

Loma Linda University Electronic Theses, Dissertations & Projects

Type 1 diabetes mellitus is a chronic inflammatory disease in which insulin producing β-cells of the pancreatic islets are killed by autoreactive cells of the immune system in response to a loss of tolerance. Dendritic cells (DC) interact predominantly with naïve T cells to regulate the delicate balance between immunity and tolerance required to maintain immunological homeostasis. In this dissertation, immature human dendritic cells (iDC) were inoculated with a chimeric fusion protein vaccine containing the pancreatic β-cell auto-antigen proinsulin linked to a mucosal adjuvant the cholera toxin B subunit (CTB-INS). Proteomic analysis of vaccine inoculated DCs revealed strong up-regulation of …

Effect Of Progressive Gaze Stability Exercises On Holistic Aspects Of Chronic Motion Sensitivity, Shilpa B. Gaikwad

Loma Linda University Electronic Theses, Dissertations & Projects

Background: Motion sensitivity, also referred to as motion sickness, is a common condition among general population. It is a complex syndrome and is associated with presence of nausea and vomiting headache, drowsiness, cold sweating, pallor of varying degrees, increased salivation. Postural instability and anxiety are also identified to be associated with motion sensitivity. There is a close relationship between the vestibular system and motion sensitivity and vestibular system. The aim of this study was to investigate the effect of progressive gaze stability exercises on holistic aspects of chronic motion sensitivity. Methods: A single blind randomized controlled trial was conducted where …

Comparative Studies Of Tslp And Il-7 In Normal Early Human Neonatal And Adult B Cell Development, Terry-Ann Milford

Loma Linda University Electronic Theses, Dissertations & Projects

Defining the role of cytokines in promoting human B cell development is important for understanding B cell leukemia and for developing strategies to restore B cell production that is lost during some therapies. The purpose of this study was to investigate the roles of the IL-7R ligands, thymic stromal lymphopoietin (TSLP) and IL- 7, in the early stages of normal postnatal and adult human B cell development. Using novel in vitro and in vivo model systems, we show that TSLP and IL-7 are able to expand B cell precursors individually and in combination from CB hematopoietic stem cells. In this …

Interacting Beliefs And Processes In Mothers Of Children Diagnosed With Autism, Lara L. South

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to expand previous research regarding beliefs in mothers of children diagnosed with autism spectrum disorders (MCDAs). Specifically, the pilot to this dissertation showed that mothers believed that the disorder was more stable than any specific behavior, but this distinction was not found for beliefs about treatment being able to control the disorder versus behaviors. Consequently, the quantitative strand of this study aimed to determine whether the mothers’ beliefs about locus of control interacted with beliefs about treatment control. It was hypothesized that mothers with a higher belief in personal locus of control (LOC) compared …

Clinical Assessment Of Pragmatics (Caps): A Validation Study, Adriana Lavi

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was bi-fold: to develop and analyze the validity and reliability of a comprehensive pragmatic language diagnostic tool, the Clinical Assessment of Pragmatics as well as comparatively examine and analyze pragmatic language profiles of three groups of adolescents. These included students with Language Impairment (LI), High-Functioning Autism (HFA) and typically developing students. During the validation phase of the study, thirty participants, ages 14 to 16 years old, were administered 3 pragmatic judgment and 3 pragmatic performance subtests comprised of 10 items each for a total of 60 test items. A series of validity and reliability measures …

The Growth And Ecology Of Upper Cambrian Microbialite Biostromes From The Notch Peak Formation In Utah, Ken P. Coulson

Loma Linda University Electronic Theses, Dissertations & Projects

Exposure of carbonate rocks within the uplifted mountains of southwestern Utah presents a unique opportunity to study the growth, morphology and ecology of two upper Cambrian microbialite reefs located within the Hellnmaria Member of the Notch Peak Formation. The first reef contains meter-length, strongly elongate microbialites that grew in a deep, subtidal marine environment. These elongate microbialites formed as a result of coalescence of round ‘algal’ heads, a process known to produce compound microbialite structures in shallow water, but seldom explored as a key factor in the elongation of deep, subtidal forms that grew in ancient environments. The second reef …

Mechanisms Of Post-Hemorrhagic Hydrocephalus After Germinal Matrix Hemorrhage, Damon William Klebe

Loma Linda University Electronic Theses, Dissertations & Projects

The inherently fragile vasculature of the germinal matrix is susceptible to rupture, possibly as a result of hemodynamic and cardiorespiratory instability associated with prematurity. Germinal matrix hemorrhage is a leading cause of morbidity and mortality in preterm and/or very low birthweight infants, and post-hemorrhagic hydrocephalus is major consequence of severe grade hemorrhages. Chronic post-hemorrhagic hydrocephalus treatment involves surgical insertion of shunts, which are costly and prone to complications. Thus, a safe non-invasive therapeutic approach towards post-hemorrhagic hydrocephalus clinical management would significantly improve the quality of life for this patient population. Thrombin, cerebroventricular blood clots, and iron have been identified as …

Chitosan Decontamination With Non-Thermal Nitrogen Plasma To Enable Internal Use, Andrew R. Crofton

Loma Linda University Electronic Theses, Dissertations & Projects

Chitosan (CS) is a ubiquitous biopolymer and is recognized as a promising biomedical material. Potential medical applications for chitosan are extensive and many have shown impressive results. However, chitosan is clinically only used as a topical hemostatic agent due to an inability to sterilize and depyrogenate chitosan without negatively altering its physical and biological properties with conventional techniques. We hypothesized that non-thermal nitrogen plasma (NtNP) would sterilize and depyrogenate chitosan while preserving its biological properties. Since plasma is a surface treatment, we micronized chitosan using cryo-ball and cryo-jet milling to increase its surface to volume ratio. Cryo-jet milling produced the …

Effects Of Microwave Irradiation On The Dimensional Stability Of Complete Denture Bases, Miguel Pappaterra

Loma Linda University Electronic Theses, Dissertations & Projects

Introduction: Maintenance for complete dentures is a role that must be undertaken by the patient. It has been determined that two minutes of microwave irradiation at 650 Watts provides denture disinfection, and three minutes provide sterilization32,34. There is insufficient data on how this practice affects the long term dimensional stability of commonly used complete denture bases in the United States. Purpose: The purpose of this study was to perform an in-vitro investigation, testing and comparing the effects of microwave irradiation on the dimensional stability of three types of complete denture bases. Materials and Methods: An edentulous master cast with reference …

Comparison Of Retention Between Milled And Conventional Denture Bases: A Clinical Study, Abdulaziz Abdullah Alhelal

Loma Linda University Electronic Theses, Dissertations & Projects

The advancement in dental material technology led to the improvement in the fabrication method of PMMA denture bases. Denture base adaptation can be influenced by the amount of polymerization shrinkage that occurs during the processing method of fabrication. CAD/CAM dentures milled from prepolymerized PMMA acrylic resin blocks theoretically have reduced or no polymerization shrinkage. There have been no clinical studies, to date, that have compared retention values between milled and conventionally processed denture bases. Therefore, the purpose of this study clinical study was to compare the retention values between conventional heat polymerized and digital milled maxillary denture bases.

Twenty patients …

Effect Of Jet Lag On Postural Stability, Faisal M. Al Mubarak

Loma Linda University Electronic Theses, Dissertations & Projects

Postural stability is essential in people’s daily life. Crossing time zones can disrupt our body clock and lead to jet lag. Some studies reported that jet lag affects human physical and cognitive functions. To the best of the authors’ knowledge, none of these studies examined the effects of jet lag on postural stability. Twenty-two healthy young adult males between 23 and 36 years of age who had a round trip flight planned between the United States and Saudi Arabia were recruited. Participants attended one preflight assessment and three post-flight assessments (within 24 hours, 48 hours, 72 hours). Participants were divided …

The Influence Of Acculturation On Meanings Of Marriage For Iranian-American Women, Golnoush Yektafar-Hooshvar

Loma Linda University Electronic Theses, Dissertations & Projects

The objective of the current research is to provide a basic framework for understanding the dynamics of Iranian marriage as women acculturate into Western norms and the implications of these experiences for those who work with them in their adjustment process. With the growing population of Iranian immigrants in the United States there is a need to understand the behaviors and values of the Iranian culture and how the culture gets transformed through socialization within the context of North America. It is crucial that a clinician understand the cultural background when working with Iranian couples in order to minimize judgment …

Role Of Slit2 In Reducing Complications After Surgical Brain Injury, Prativa Sherchan

Loma Linda University Electronic Theses, Dissertations & Projects

Surgical brain injury (SBI) is the inadvertent injury to brain tissue at the perisurgical site which occurs due to neurosurgical maneuvers such as incision, retraction, and electrocoagulation that can result in post-operative complications. Blood brain barrier (BBB) disruption and neuroinflammation are major pathophysiological consequences after neurosurgical injury. Blood brain barrier dysfunction leads to increased influx of water and plasma proteins as well as peripheral immune cell infiltration into the brain parenchyma that further potentiates brain edema and worsens post-operative neurological function. Activated resident immune cells and infiltrated peripheral immune cells release inflammatory mediators and promote oxidative stress and cell death …

The Influence Of Parental Mental Health On Child Outcomes: The Role Of The Parenting Process, Meredith L. Dennis

Loma Linda University Electronic Theses, Dissertations & Projects

Parents of children affected by developmental delays (DD) have been shown to experience elevated levels of parenting stress compared to parents of typically developing children. Recent studies suggest that higher levels of parenting stress can adversely impact child behavior and development, such that higher levels of parenting stress are often associated with higher levels of behavior problems and negative developmental outcomes. However the specific mechanisms through which parenting stress influences child outcomes remain unclear. The overall parenting process may be one potential medium through which parenting stress influences both child behavioral and developmental outcomes. The current study involved both qualitative …

Taphonomy Of Sediments: Bioturbation In The Triassic Moenkopi Formation In Southwestern Utah, James Vernon Bird Jr.

Loma Linda University Electronic Theses, Dissertations & Projects

Measurement of bioturbation reflects physical and biological processes operating over time and can be used to reveal information about paleo-environments. The purpose of this study was to determine the intensity of bioturbation in Triassic Moenkopi Formation at Hurricane Mesa in Southwestern Utah. This formation is interpreted as having been deposited mostly in large ancient river channels, tidal flats, delta and shallow marine environments. Five stratigraphic sections measured in the Virgin Limestone Member provided the basis for this study. Detailed descriptions and quantification of bioturbation were recorded in each of the sections. Similar treatment was given to additional study sites in …

Nicu Parental Mental Health And Infant Outcomes: Effects Of Psychological Well-Being And Psychopathology, Kathleen H. Parker

Loma Linda University Electronic Theses, Dissertations & Projects

Previous research has shown that having a child in the Neonatal Intensive Care Unit (NICU) is stressful for parents and that parents of NICU infants exhibit higher levels of stress compared to parents of healthy infants (Carter, Mulder, & Darlow, 2007; MacDonald, 2007; Treyvaud et al., 2010). As a result of these high levels of stress, NICU parents are at risk for developing psychopathology. Studies have found correlations between parental psychopathology and lower scores on measures of psychological well-being such as self-acceptance and autonomy (Bhullar, Hine, & Phillips, 2014; Valiente et al., 2013). Additionally, research has indicated that some well-being …

Effect Of Vestibular Adaptation Exercises On Chronic Motion Sensitivity, Danah Alyahya

Loma Linda University Electronic Theses, Dissertations & Projects

Dizziness is one of the most common complaints reported to primary care physicians. It is often associated with vestibular dysfunction and typically impacts postural stability. Motion sickness, or motion sensitivity, is stimulated by abnormal spatial orientation and is a common symptom related to dizziness and postural instability. The main cause of the motion sensitivity is aberrant sensory input from the visual, vestibular and somatosensory systems. The aim of this study was to measure the effect of vestibular adaptation exercises on postural stability in young healthy adults with subjective awareness of chronic motion sensitivity.

Methods: Fifty healthy male and female …

Soft-Sediment Deformation And Dune Collapse In The Navajo Sandstone, Colby Ford

Loma Linda University Electronic Theses, Dissertations & Projects

The Canyon Overlook Trail of Zion National Park follows an outcrop of Navajo Sandstone, which displays a uniquely well-exposed assemblage of features associated with failure of the lee face of a large eolian dune, and run-out over an expanse of interdune sediments downwind of that bedform. Exposed features include dramatic folds in the interdune succession and a stacked series of thrust sheets incorporating both interdune and overlying dune deposits. Thrust surfaces display consistent strikes, parallel to those of undeformed foresets, and incorporate zones of brittle failure and fluid deformation, including folds overturned in the direction of foreset dip. These features …