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- Creators: Harrington Bioengineering Program
- Member of: Theses and Dissertations
- Status: Published

Motor behavior is prone to variable conditions and deviates further in disorders affecting the nervous system. A combination of environmental and neural factors impacts the amount of uncertainty. Although the influence of these factors on estimating endpoint positions have been examined, the role of limb configuration on endpoint variability has been mostly ignored. Characterizing the influence of arm configuration (i.e. intrinsic factors) would allow greater comprehension of sensorimotor integration and assist in interpreting exaggerated movement variability in patients. In this study, subjects were placed in a 3-D virtual reality environment and were asked to move from a starting position to one of three targets in the frontal plane with and without visual feedback of the moving limb. The alternating of visual feedback during trials increased uncertainty between the planning and execution phases. The starting limb configurations, adducted and abducted, were varied in separate blocks. Arm configurations were setup by rotating along the shoulder-hand axis to maintain endpoint position. The investigation hypothesized: 1) patterns of endpoint variability of movements would be dependent upon the starting arm configuration and 2) any differences observed would be more apparent in conditions that withheld visual feedback. The results indicated that there were differences in endpoint variability between arm configurations in both visual conditions, but differences in variability increased when visual feedback was withheld. Overall this suggests that in the presence of visual feedback, planning of movements in 3D space mostly uses coordinates that are arm configuration independent. On the other hand, without visual feedback, planning of movements in 3D space relies substantially on intrinsic coordinates.

Cerebral aneurysms, also known as intracranial aneurysms, are sac-like lesions in the arteries of the brain that can rupture to cause subarachnoid hemorrhaging, damaging and killing brain cells. Metal coil embolization has been traditionally used to occlude and treat cerebral aneurysms to limited success, but polymer embolization has been suggested, because it can provide a greater fraction of occlusion. One such polymer with low cytotoxicity is poly(propylene glycol)diacrylate (PPODA) crosslinked via Michael-type addition with pentaerythritol tetrakis(3-mercaptopropionate) (QT). This study was performed to examine the behavior of PPODA-QT gel in vitro under pulsatile flow emulating physiological conditions. An idealized cerebral aneurysm flow model was designed based on geometries associated with an increase in rupture risk. Pressure was monitored at the apex of the aneurysm dome for varied flow rates and polymer filling fractions of 32.4, 78.2, and 100%. The results indicate that the amount of PPODA-QT deployed into the aneurysm decreases the peak-to-peak oscillation in pressure at the aneurysm wall by an inverse proportion. The 32.4 and 78.2% treatments did not significantly decrease the mean pressure applied to the aneurysm dome, but the 100% treatment greatly reduced it by diverting flow. This study indicates that the maximum filling fraction after swelling of PPODA-QT polymer should be deployed into the aneurysmal sac for treatment.

This thesis explores the task of creating industry-based marketing materials to assist academic programs in their recruitment of high school and community college students. With consistent reductions to public university budgets there is an increasing pressure on academic programs to raise their student enrollment figures, as student count is often cited as one of the most important statistics when making budget decisions. Many academic programs are ill-equipped to perform this task, however, as their personnel are not trained as recruiters, but rather as professors and industry professionals; furthermore, the university-level recruitment staff faces the impossible task of advertising every department's recruitment message. The Del E. Webb School of Construction has embarked upon a journey to create industry-based marketing materials to aid them in their recruitment efforts. Construction management (CM) has traditionally been viewed as a technology major relegated to vocational students and those not fit for baccalaureate programs. In recent years that perception has changed, however, as the industry has become increasingly complex and CM programs actively work to recruit students. In an attempt to increase that recruitment, the Del E. Webb School has created marketing materials that are signature to the program featuring the world's most widely-used building material, concrete, to create a keepsake for prospective students. This keepsake comes in the form of concrete replicas of the new ASU Pitchfork logo. These pitchforks are small and designed to be mass produced so that they can be handed out at recruitment events either on campus or in local schools. The Del E. Webb School had previously experimented with flexible rubber molds and flowable mixtures, such that the models could be easily cast and rapidly demolded and reset for casting. There were issues, however, as those pitchforks did not meet desired level of quality and were difficult to reproduce. This thesis thus describes an experimental program examining different casting and demolding regimens in an attempt to find the optimal way to create the pitchforks on a consistent basis. Following this, an operations manual for how to create the pitchforks was created in order to ensure that successive cohorts of construction students can reproduce the pitchforks in preparation for the School's annual recruitment events.

Motor behavior is prone to variable conditions and deviates further in disorders affecting the nervous system. A combination of environmental and neural factors impacts the amount of uncertainty. Although the influence of these factors on estimating endpoint positions have been examined, the role of limb configuration on endpoint variability has been mostly ignored. Characterizing the influence of arm configuration (i.e. intrinsic factors) would allow greater comprehension of sensorimotor integration and assist in interpreting exaggerated movement variability in patients. In this study, subjects were placed in a 3-D virtual reality environment and were asked to move from a starting position to one of three targets in the frontal plane with and without visual feedback of the moving limb. The alternating of visual feedback during trials increased uncertainty between the planning and execution phases. The starting limb configurations, adducted and abducted, were varied in separate blocks. Arm configurations were setup by rotating along the shoulder-hand axis to maintain endpoint position. The investigation hypothesized: 1) patterns of endpoint variability of movements would be dependent upon the starting arm configuration and 2) any differences observed would be more apparent in conditions that withheld visual feedback. The results indicated that there were differences in endpoint variability between arm configurations in both visual conditions, but differences in variability increased when visual feedback was withheld. Overall this suggests that in the presence of visual feedback, planning of movements in 3D space mostly uses coordinates that are arm configuration independent. On the other hand, without visual feedback, planning of movements in 3D space relies substantially on intrinsic coordinates.

Growing concern over health risks associated with environmental contaminants has prompted an increase in the search for effective detection methods. The available options provide acceptable sensitivity and specificity, but with high purchase and maintenance costs. Herein, a low-cost, portable environmental contaminant sensor was developed using electrochemical techniques and an efficient hydrogel capture mechanism. The sensor operates with high sensitivity and maintains specificity without the added requirement of extensive electrode modification. Rather, specificity is obtained by choosing specific potential regions in which individual contaminants show reduction or oxidation activity. A calibration curve was generated showing the utility of the sensor in detecting gas compounds reliably in reference to a current state of the art sensor. Reusability of the sensor was also demonstrated with a cyclic exposure test in which response reversibility was observed. As such, the investigated sensor shows great promise as a replacement technology in the current environmental contaminant detector industry.

Medial compartment knee osteoarthritis (OA) is a disease whose severity has been associated with the peak adduction moment during walking (pKAM). Unfortunately, measuring patients' pKAM to track their therapy progress involves the use of a gait laboratory which is expensive and time intensive. This study aimed to develop and assess a regression method to predict the pKAM using only plantar pressure measurements. This approach could greatly reduce the burden of evaluating pKAM.

Acetaminophen, commonly found in Tylenol and other over the counter (OTC) pharmaceuticals, was electrochemically characterized on custom made, flexible, screen printed electrodes (SPEs) to serve as a model target pharmaceutical found in flowing water lines. Carbon, silver/silver chloride, and insulator paste inks were printed onto polyethylene naphthalateolyester (PEN) using custom made stencils for a 4x1 array of 3-electrode electrochemical cells. Cyclic voltammetry was performed to find the electrical potential corresponding to the greatest current response and the experiments were conducted using amperometric current-time mode (AMP*i-t). The physical limitations of SPEs as well as the detection limitations of the target, such as pH and temperature were tested. A concentration gradient of the target was fitted with a linear curve (R2 0.99), and a lower limit of detection of 14.5 μM. It was also found that both pH and temperature affect the current produced by acetaminophen at a fixed concentration, and that the sensors can detect target in a continuous flow. A flow apparatus consisting of an inlet and effluent pipe served as the flow model into which a rolled up flexible electrode array was inserted. The broader goal of this research is to develop a highly sensitive electrode array on flexible substrates which can detect multiple targets simultaneously. Acetaminophen was chosen due to its electro-active properties and its presence in most public water lines in the United States.

Access to clean water is an issue that abounds in many areas across the world. It is estimated that over 770 million people lack access to improved sources of water. However, the lack of access to clean water does not just affect people's health; it is a problem that affects three major areas. Because people do not have clean drinking water, millions of school days are missed per year due to water-related disease or children being forced to procure clean water. Also, gender inequalities result from women bearing the majority of the responsibility of walking long distances to find a source of potable water. Therefore, lack of access to clean water affects people's health, their education, and gender equality. The problem is not that there is a lack of technologies to provide clean water; the problem is that these technologies are not being implemented sustainably in the areas that need them most. To bring better access of clean water to people in developing nations, 33 Buckets has designed a distribution platform that uses schools as the central point for water distribution to local communities. A sustainable filtration system will be installed at the school to provide clean water for the people at the school. People in the nearby community will also be able to get free water if they bring their own containers to the school. To maintain the filter and provide it with any repairs that are necessary, water will be sold to nearby businesses lower than the current market prices. These profits will be used to ensure the quality of the filtration system and also to provide educational improvements to the school. An advisory committee made up of men and women will be assembled to run the filtration business and handle the finances. A pilot project to implement this model has been identified as the Rahima Hoque Girls School in rural Bangladesh. The team will travel to Bangladesh in Summer 2014 to install a filter at the school, purchase water testing supplies and containers, and meet with the advisory committee to go over final logistical details. Financial projections show that if the filter operates at 50% of its expected frequency and water is sold 5 days a week for 52 weeks, the school will generate $33,532.31. These profits are more than enough to maintain the system and pay for educational improvements to the school. Once implementation of the site is completed, the project will be monitored to track how the water selling business is operating. If the model is shown to be successful, it can then be scaled to other nearby schools or other countries with water contamination problems.

The development of skeletal muscle during embryogenesis and repair in adults is dependent on the intricate balance between the proliferation of myogenic progenitor cells and the differentiation of those cells into functional muscle fibers. Recent studies demonstrate that the Drosophila melanogaster transcription factor CG9650 is expressed in muscle progenitor cells, where it maintains myoblast numbers. We are interested in the Mus musculus orthologs Bcl11a and Bcl11b (C2H2 zinc finger transcription factors), and understanding their role as molecular switches that control proliferation/differentiation decisions in muscle progenitor cells. Expression analysis revealed that Bcl11b, but not Bcl11a, is expressed in the region of the mouse embryo populated with myogenic progenitor cells; gene expression studies in muscle cell culture confirmed Bcl11b is also selectively transcribed in muscle. Furthermore, Bcl11b is down-regulated with differentiation, which is consistent with the belief that the gene plays a role in cell proliferation.

Cardiopulmonary resuscitation (CPR) is an emergency course of action developed to sustain oxygenated blood flow in persons suffering from cardiac arrest by manually compressing the heart in the chest and providing rescue ventilations. The best-selling CPR manikins, an integral part of training, lack biofidelic characteristics in appearance, feel, and response, and as a result, the rescuer's learning experience suffers. The objective of this thesis was to test the compressibility properties of different foams and thermoplastics in order to determine which material would most accurately imitate a human chest response. The results suggested that styrene-ethylene/butylene-styrene (SEBS) was the best choice, because its increasing stiffness under increasing compression was characteristic of a human chest cavity. Further testing must be done to determine the best composition of SEBS, analyze its response under cyclic compressions, and improve its durability.