Medical Biophysics Commons^™

Development Of Low Frequency Electron Paramagnetic Resonance Methods And Instrumentation For Biological Applications, Laura A. Buchanan

Electronic Theses and Dissertations

EPR is a powerful biophysical tool that can be used to measure tumor physiology. With the addition of magnetic field gradients, the spectral properties of paramagnetic species can be mapped. To facilitate EPR imaging, methods and instrumentation at frequencies between 250 MHz and 1 GHz were developed.

At low spin concentrations, the rapid scan background signal is often many times larger than the EPR signal of interest. To help remove the background contribution, a data acquisition procedure that takes advantage of a cross-loop resonator and bipolar power supplies was developed at 250 MHz. In this procedure, two scans are collected. …

The Role Of The Mir-200 Family On The Tumor Suppressor Rassf2 And The Effect On Mapk Pathway Activity In Colorectal Cancer., Jane V. Carter

Electronic Theses and Dissertations

This dissertation investigated the role of the miR-200 family in normal colon epithelial (CCD 841) and Dukes’ C (HT-29) colorectal cancer (CRC) cell lines. Our aim was to characterize expression of the miR-200 family (miR-200a, miR-200b, miR-200c, miR-141, and miR-429) in colorectal cell lines, study their effect on the tumor suppressor Ras Associated Domain-Containing Protein (RASSF) 2 and on subsequent activity within the mitogen-activated protein kinase (MAPK) signaling pathway. We wanted to determine whether regulation of miR-200 family members could change cell behavior towards more “cancer-like” in a normal colon epithelium (CCD 841) cell line, or less “cancer-like” in a …

The Influence Of Mir-99a On Mtor Signaling Regulation In Colorectal Cancer Cell Lines., Jonathan Rice

Electronic Theses and Dissertations

Colorectal cancer (CRC) is the third most common cancer worldwide and the fourth most common cause of death. These are staggering statistics for a disease that can essentially be cured if caught early and the pathology is favorable to therapeutic intervention. There is currently a drastic decrease in five year survival as the cancer stage increases from locally confined disease to metastatic disease. These statistics suggest that although some strides have been made with colon cancer screening and early intervention, there is still much room for improvement in both screening and treatment of CRC. One of the pathways that have …

Strategies Of Balancing: Regulation Of Posture As A Complex Phenomenon, Allison Leich Hilbun

Electronic Theses and Dissertations

The complexity of the interface between the muscular system and the nervous system is still elusive. We investigated how the neuromuscular system functions and how it is influenced by various perturbations. Postural stability was selected as the model system, because this system provides complex output, which could indicate underlying mechanisms and feedback loops of the neuromuscular system. We hypothesized that aging, physical pain, and mental and physical perturbations affect balancing strategy, and based on these observations, we constructed a model that simulates many aspects of the neuromuscular system. Our results show that aging changes the control strategy of balancing from …

Biophysical Sources Of 1/F Noises In Neurological Tissue, Alan Paris

Electronic Theses and Dissertations

High levels of random noise are a defining characteristic of neurological signals at all levels, from individual neurons up to electroencephalograms (EEG). These random signals degrade the performance of many methods of neuroengineering and medical neuroscience. Understanding this noise also is essential for applications such as real-time brain-computer interfaces (BCIs), which must make accurate control decisions from very short data epochs. The major type of neurological noise is of the so-called 1/f-type, whose origins and statistical nature has remained unexplained for decades. This research provides the first simple explanation of 1/f-type neurological noise based on biophysical fundamentals. In addition, noise …