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Interactions Of Cardiomyocytes And Myofibroblasts: An Experimental And Theoretical Model Study, Teresa Abney
Interactions Of Cardiomyocytes And Myofibroblasts: An Experimental And Theoretical Model Study, Teresa Abney
All Theses and Dissertations (ETDs)
Cardiomyocytes and fibroblasts make up the majority of cells in natural myocardium. While cardiomyocytes are primarily responsible for the mechanical contraction, fibroblasts are responsible for maintaining the extracellular matrix and tissue compliance. In response to pathologies such as hypertension or infarction, fibroblasts in the heart can convert to myofibroblasts, a larger and more contractile phenotype between a fibroblast and a smooth muscle cell. Myofibroblasts are essential to wound healing, but can change the compliance and functioning of heart tissue and can produce pathological fibrosis, formation of excess fibrous connective tissue. In developing therapeutic approaches it is essential to understand how …
Evaluating Environmental Cues That Affect Schwann Cell Gene Expression To Enhance Peripheral Nerve Regeneration, Nithya Jesuraj
Evaluating Environmental Cues That Affect Schwann Cell Gene Expression To Enhance Peripheral Nerve Regeneration, Nithya Jesuraj
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The goal of this thesis was to evaluate the effects of different environmental cues on Schwann cell: SC) differentiation and phenotype maintenance to design better SC transplantation therapies for peripheral nerve repair. First, a set of markers, specific for motor or sensory-derived SCs were identified from the literature and gene chips. After 30 days, gene expression patterns of SCs, after expansion in culture, were dysregulated. Cues that have been hypothesized to re-differentiate the SCs in vitro are extracellular matrix: ECM) molecules, growth factors: GFs), and acetylcholine: Ach). To test the effects of ECM, SCs were transplanted into acellular nerve grafts: …
Magnetic Resonance Elastography Of The Brain: From Phantom To Mouse To Man, Erik Clayton
Magnetic Resonance Elastography Of The Brain: From Phantom To Mouse To Man, Erik Clayton
All Theses and Dissertations (ETDs)
The overall objective of this study is to develop magnetic resonance elastography: MRE) imaging to better understand brain deformation, brain tissue mechanical properties, and brain-skull interaction in vivo. The findings of this study provide parameters for numerical models of human head biomechanics, as well as data for validation of these models. Numerical simulations offer enormous potential to the study of traumatic brain injury: TBI) and may also contribute to the development of prophylactic devices for high-risk subjects: e.g., military personnel, first-responders, and athletes). Current numerical models have not been adequately parameterized or validated and their predictions remain controversial. This dissertation …
Mechanisms Of Early Brain Morphogenesis, Benjamen Filas
Mechanisms Of Early Brain Morphogenesis, Benjamen Filas
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In structures with obvious mechanical function, like the heart and bone, the relationship of mechanical forces to growth and development has been well studied. In contrast, other than the problem of neurulation: formation of the neural tube), developmental mechanisms in the nervous system have received relatively little attention. The central aim of this research is to characterize the biophysical mechanisms that shape the early embryonic brain. Experiments were performed primarily in the chicken brain, which is morphologically similar to humans during early stages of development. Proposed mechanisms were tested using computational models to ensure that hypotheses are consistent with physical …
Neural Adaptation And The Effect Of Interelectrode Spacing On Epidural Electrocorticography For Brain-Computer Interfaces, Adam Rouse
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Electrocorticography: ECoG) is increasingly being identified as a safe and reliable recording technique for both Brain-Computer Interface: BCI) applications as well as neurophysiology studies. This thesis describes some of the first real-time closed-loop BCI studies of chronic ECoG in non-human primates. Epidural microECoG electrodes developed in our lab were implanted in three monkeys with the electrode array centered over primary motor cortex: M1). Monkeys were then trained to perform a one-dimensional BCI task. The BCI control scheme was independent of any prior screening for task-related activity. All three monkeys successfully learned to perform the task with multiple control configurations and …
Quantification And Reconstruction In Photoacoustic Tomography, Zijian Guo
Quantification And Reconstruction In Photoacoustic Tomography, Zijian Guo
All Theses and Dissertations (ETDs)
Optical absorption is closely associated with many physiological important parameters, such as the concentration and oxygen saturation of hemoglobin. Conventionally, accurate quantification in PAT requires knowledge of the optical fluence attenuation, acoustic pressure attenuation, and detection bandwidth. We circumvent this requirement by quantifying the optical absorption coefficients from the acoustic spectra of PA signals acquired at multiple optical wavelengths. We demonstrate the method using the optical-resolution photoacoustic microscopy: OR-PAM) and the acoustical-resolution photoacoustic microscopy: AR-PAM) in the optical ballistic regime and in the optical diffusive regime, respectively. The data acquisition speed in photoacoustic computed tomography: PACT) is limited by the …
Developing High-Density Diffuse Optical Tomography For Neuroimaging, Brian White
Developing High-Density Diffuse Optical Tomography For Neuroimaging, Brian White
All Theses and Dissertations (ETDs)
Clinicians who care for brain-injured patients and premature infants desire a bedside monitor of brain function. A decade ago, there was hope that optical imaging would be able to fill this role, as it combined fMRI's ability to construct cortical maps with EEG's portable, cap-based systems. However, early optical systems had poor imaging performance, and the momentum for the technique slowed. In our lab, we develop diffuse optical tomography: DOT), which is a more advanced method of performing optical imaging. My research has been to pioneer the in vivo use of DOT for advanced neuroimaging by: 1) quantifying the advantages …
Movement Function Follows Spatial Form: Coordinate System Implications For Online Visual Feedback Control Of The Hand, Justin Brooks
Movement Function Follows Spatial Form: Coordinate System Implications For Online Visual Feedback Control Of The Hand, Justin Brooks
All Theses and Dissertations (ETDs)
Closed loop visual feedback control of the hand is essential for accurate reaching movements. Without visual signals of either the hand or target position, reaches are inaccurate and imprecise; therefore the brain uses a relative positional signal to control movements online. Previous studies suggest that movements are planned and represented in a polar coordinate system and that the dimensions, direction and extent are independently specified and processed. We were interested to find out whether there was behavioral evidence for the independent control of hand direction and extent as a movement unfolded. We asked subjects to make a reaching movement in …