Global ETD Search

101	A Comparison of Fatigue During Cardiocerebral Resuscitation with Different Compression Rates Among Layperson and Professional Rescuers Cassidy, Christopher 01 August 2014 (has links) (PDF) Quality chest compressions during Cardiopulmonary Resuscitation (CPR) are vital to maintaining adequate perfusion of oxygenated blood to the organs of the body to sustain life. Over the years, the compression rate recommended in Basic Life Support (BLS)/ Advanced Cardiac Life Support (ACLS) protocols for the best possible outcome has risen, and with that increase there are questions regarding rescuer fatigue and the effectiveness of compressions. Layperson and professional rescuers, answering to an emergency, both maintain continuous chest compressions until advanced life support arrives. Depending on the location, this arrival time would most likely be longer than the two minute standard time given to rotate rescuers before fatigue compromises performance. The objective of this research was to investigate the level of rescuer fatigue associated with continuous compressions, varying compression rates, physical fitness, gender, and among layperson versus professional rescuers. Sixty-one participants performed uninterrupted chest compressions on a manikin for 15 minutes. Before performing compressions, physical fitness was evaluated using a YMCA bench press for an assessment of upper body strength/endurance and a 3-minute step test to evaluate aerobic fitness. Subjects performed two trials at compression rates of greater or equal to 80 and greater or equal to 100 per minute with a 5-minute rest between trials. Male professional rescuers had a greater strength/endurance, and thus were able to perform compressions for a longer period of time compared to their female counterparts. Compression duration and the YMCA Bench Press test score were significantly correlated (p = .0135). Cardiocerebral Resuscitation providers should maintain an adequate upper body strength, particularly if they may be required to perform continuous chest compressions at high rates for more than a few minutes. EMS response time continuous compressions compression rates rescuer fatigue cardiopulmonary resuscitation 15 minute trial Exercise Physiology Health Information Technology Laboratory and Basic Science Research Other Physiology Physiology Systems and Integrative Physiology
102	Electromechanical fatigue properties of dielectric elastomer stretch sensors under orthopaedic loading conditions Persons, Andrea Karen 05 May 2022 (has links) Fatigue testing of stretch sensors often focuses on high amplitude, low-cycle fatigue (LCF) behavior; however, when used for orthopaedic, athletic, or ergonomic assessments, stretch sensors are subjected to low amplitude, high-cycle fatigue (HCF) conditions. As an added layer of complexity, the fatigue testing of stretch sensors is not only focused on the life of the material comprising the sensor, but also on the reliability of the signal produced during the extension and relaxation of the sensor. Research into the development of a smart sock that can be used to measure the range of motion (ROM) of the ankle joint during athletic practices and competitions using stretch sensors is ongoing at Mississippi State University. The current smart sock prototype utilizes StretchSense™ StretchFABRIC capacitive dielectric elastomer sensors. These sensors are no longer manufactured, and FlexSense stretch sensors are being investigated as a potential replacement. To assess the reliability of the signal of the StretchFABRIC sensors currently used in the prototype, two sensors were subjected to 25,000 cycles of fatigue, under with simultaneous capture of the capacitance. The capacitances of the fatigued sensors were then compared to the capacitance of an unfatigued StretchFABRIC sensor during participant trials. Participants completed four static movements and six dynamic gait trials using either the fatigued or unfatigued sensor. Following completion of the initial static and dynamic movements, the movements were repeated using the opposite sensor. Comparison of the fatigued sensor to the unfatigued sensor revealed an upward drift in the capacitance of the fatigued sensor for all trials. Two FlexSense sensors were then subjected to either 450,000 or 250,000 cycles of fatigue with simultaneous capture of the signal from the sensor. To assess the signal, the peak capacitance recorded during the fatigue test was compared to the peak stretch percentage produced by the sensor. The peak displacement remained tight about the mean, while the peak stretch percentage exhibited a high level of scatter. From a materials standpoint, the sensors conformed to the Rabinowitz-Beardmore model of polymer fatigue where an initial monotonic overload of the material is followed by a transition to cyclic stability of the material. high-cycle fatigue low-cycle fatigue Coffin-Manson Equation Basquin's Equation polymer polymer model ankle joint gait fatigue testing standards signal processing Biomechanics Electro-Mechanical Systems Engineering Mechanics Laboratory and Basic Science Research Polymer and Organic Materials Signal Processing
103	Teaching of scientific investigations by life and natural science educators in Bushbuckridge Dlamini, Amos Paspas 31 August 2008 (has links) The study describes the teaching of scientific investigations by Life and Natural Sciences educators in the Bushbuckridge Region in Mpumalanga Province, South Africa. A quantitative survey method was exploited using a Cluster sampling method. The study was conducted a year after the introduction of the National Curriculum Statement in Grade 10, in South African schools. The study found that most educators use teacher-centred teaching methodologies rather than open inquiry in teaching scientific investigations. Schools still have a shortage of infrastructure, teaching resources and references, which make it difficult for the educators to shift towards the expected new system of teaching. Teachers are confronted with language barriers, heavy workload and insufficient retraining in the new curriculum. / Science and Technology Education / M.Ed. problem based learning cooperative instruction guided inquiry open inquiry directed inquiry cookbook inquiry integrated science process skills basic science process skills inquiry instruction Science process skills 507.126827
104	MECHANISMS OF TRINUCLEOTIDE REPEAT INSTABILITY DURING DNA SYNTHESIS Chan, Kara Y. 01 January 2019 (has links) Genomic instability, in the form of gene mutations, insertions/deletions, and gene amplifications, is one of the hallmarks in many types of cancers and other inheritable genetic disorders. Trinucleotide repeat (TNR) disorders, such as Huntington’s disease (HD) and Myotonic dystrophy (DM) can be inherited and repeats may be extended through subsequent generations. However, it is not clear how the CAG repeats expand through generations in HD. Two possible repeat expansion mechanisms include: 1) polymerase mediated repeat extension; 2) persistent TNR hairpin structure formation persisting in the genome resulting in expansion after subsequent cell division. Recent in vitro studies suggested that a family A translesion polymerase, polymerase θ (Polθ), was able to synthesize DNA larger than the template DNA. Clinical and in vivo studies showed either overexpression or knock down of Polθ caused poor survival in breast cancer patients and genomic instability. However, the role of Polθ in TNR expansion remains unelucidated. Therefore, we hypothesize that Polθ can directly cause TNR expansion during DNA synthesis. The investigation of the functional properties of Polθ during DNA replication and TNR synthesis will provide insight for the mechanism of TNR expansion through generations. DNA Translesion Polymerase-Polymerase θ Base Excision Repair Hairpin Bypass Synthesis Mn2+/Mg2+ Trinucleotide Repeats Expansion Huntington’s Disease Biochemistry Cell Biology Genetic Processes Genetics Laboratory and Basic Science Research Medical Genetics Molecular Biology Molecular Genetics Nervous System Diseases
105	Teaching of scientific investigations by life and natural science educators in Bushbuckridge Dlamini, Amos Paspas 31 August 2008 (has links) The study describes the teaching of scientific investigations by Life and Natural Sciences educators in the Bushbuckridge Region in Mpumalanga Province, South Africa. A quantitative survey method was exploited using a Cluster sampling method. The study was conducted a year after the introduction of the National Curriculum Statement in Grade 10, in South African schools. The study found that most educators use teacher-centred teaching methodologies rather than open inquiry in teaching scientific investigations. Schools still have a shortage of infrastructure, teaching resources and references, which make it difficult for the educators to shift towards the expected new system of teaching. Teachers are confronted with language barriers, heavy workload and insufficient retraining in the new curriculum. / Science and Technology Education / M.Ed. problem based learning cooperative instruction guided inquiry open inquiry directed inquiry cookbook inquiry integrated science process skills basic science process skills inquiry instruction Science process skills 507.126827
106	Building the Interphase Nucleus: A study on the kinetics of 3D chromosome formation, temporal relation to active transcription, and the role of nuclear RNAs Abramo, Kristin N. 28 July 2020 (has links) Following the discovery of the one-dimensional sequence of human DNA, much focus has been directed on microscopy and molecular techniques to learn about the spatial organization of chromatin in a 3D cell. The development of these powerful tools has enabled high-resolution, genome-wide analysis of chromosome structure under many different conditions. In this thesis, I focus on how the organization of interphase chromatin is established and maintained following mitosis. Mitotic chromosomes are folded into helical loop arrays creating short and condensed chromosomes, while interphase chromosomes are decondensed and folded into a number of structures at different length scales ranging from loops between CTCF sites, enhancers and promoters to topologically associating domains (TADs), and larger compartments. While the chromatin organization at these two very different states is well defined, the transition from a mitotic to interphase chromatin state is not well understood. The aim of this thesis is to determine how interphase chromatin is organized following mitotic chromosome decondensation and to interrogate factors potentially responsible for driving the transition. First, I determine the temporal order with which CTCF-loops, TADs, and compartments reform as cells exit mitosis, revealing a unique structure at the anaphase-telophase transition never observed before. Second, I test the role of transcription in reformation of 3D chromosome structure and show that active transcription is not required for the formation of most interphase chromatin features; instead, I propose that transcription relies on the proper formation of these structures. Finally, I show that RNA in the interphase nucleus can be degraded with only slight consequences on the overall chromatin organization, suggesting that once interphase chromatin structures are achieved, the structures are stable and RNA is only required to reduce the mixing of active and inactive compartments. Together, these studies further our understanding of how interphase structures form, how these structures relate to functional activities of the interphase cell, and the stability of chromatin structures over time. chromatin Hi-C transcription RNA telophase kinetics cell cycle mitosis interphase chromosome conformation capture CTCF condensin cohesin TAD topologically associated domain loop extrusion microphase separation NCAPH Rad21 NCAPH2 synchronization G1 entry triptolide DRB RNase A Bioinformatics Cell Biology Computational Biology Genomics Laboratory and Basic Science Research Molecular Biology Molecular Genetics Systems Biology
107	Reversing Cancer Cell Fate: Driving Therapeutic Differentiation of Hepatoblastoma to Functional Hepatocyte-Like Cells Smith, Jordan L. 20 March 2020 (has links) Background & Aims: Despite advances in surgical care and chemotherapeutic regimens, the five-year survival rate for Stage IV Hepatoblastoma (HB), the predominant pediatric liver tumor, remains at 27%. YAP1 and β-Catenin co-activation occurs in 80% of children’s HB; however, a lack of conditional genetic models precludes exploration of tumor maintenance and therapeutic targets. Thus, the clinical need for a targeted therapy remains unmet. Given the predominance of YAP1 and β-catenin activation in children’s tumors, I sought to evaluate YAP1 as a therapeutic target in HB. Approach & Results: Herein, I engineered the first conditional murine model of HB using hydrodynamic injection to deliver transposon plasmids encoding inducible YAP1S127A, constitutive β-CateninDelN90, and a luciferase reporter to murine liver. Tumor regression was evaluated using in vivo bioluminescent imaging, and tumor landscape characterized using RNA sequencing, ATAC sequencing and DNA foot-printing. Here I show that YAP1 withdrawal in mice mediates >90% tumor regression with survival for 230+ days. Mechanistically, YAP1 withdrawal promotes apoptosis in a subset of tumor cells and in remaining cells induces a cell fate switch driving therapeutic differentiation of HB tumors into Ki-67 negative “hbHep cells.” hbHep cells have hepatocyte-like morphology and partially restored mature hepatocyte gene expression. YAP1 withdrawal drives formation of hbHeps by modulating liver differentiation transcription factor (TF) occupancy. Indeed, tumor-derived hbHeps, consistent with their reprogrammed transcriptional landscape, regain partial hepatocyte function and can rescue liver damage in mice. Conclusions: YAP1 withdrawal, without modulation of oncogenic β-Catenin, significantly regresses hepatoblastoma, providing the first in vivo data to support YAP1 as a therapeutic target for HB. Modulating YAP1 expression alone is sufficient to drive long-term regression in hepatoblastoma because it promotes cell death in a subset of tumor cells and modulates transcription factor occupancy to reverse the fate of residual tumor cells to mimic functional hepatocytes. Therapeutic Differentiation Targeted Therapy Pediatric Cancer Oncogene Liver cancer Mouse Model Conditional Model Genetic Inducible Hepatoblastoma Oncogene Addiction Tumor Dormancy Drug Discovery YAP B-Catenin Hydrodynamic Injection Sleeping Beauty System Tranposase Lineage Tracing Cancer Biology Cell Biology Digestive System Digestive System Diseases Disease Modeling Gastroenterology Genetic Processes Genetics Hepatology Laboratory and Basic Science Research Medical Molecular Biology Molecular Genetics Neoplasms Oncology Pediatrics Translational Medical Research

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