Matching Items (394)
Description
During the downswing all golfers must roll their forearms and twist the club handle in order to square the club face into impact. Anecdotally some instructors say that rapidly twisting the handle and quickly closing the club face is the best technique while others disagree and suggest the opposite. World class golfers have swings with a range of club handle twist velocities (HTV) from very slow to very fast and either method appears to create a successful swing. The purpose of this research was to discover the relationship between HTV at impact and selected body and club biomechanical characteristics during a driver swing. Three-dimensional motion analysis methods were used to capture the swings of 94 tour professionals. Pearson product-moment correlation was used to determine if a correlation existed between HTV and selected biomechanical characteristics. The total group was also divided into two sub-groups of 32, one group with the fastest HTV (Hi-HTV) and the other with the slowest HTV (Lo-HTV). Single factor ANOVAs were completed for HTV and each selected biomechanical parameter. No significant differences were found between the Hi-HTV and Lo-HTV groups for both clubhead speed and driving accuracy. Lead forearm supination velocity at impact was found to be significantly different between groups with the Hi-HTV group having a higher velocity. Lead wrist extension velocity at impact, while not being significantly different between groups was found to be positive in both groups, meaning that the lead wrist is extending at impact. Lead wrist ulnar deviation, lead wrist release and trail elbow extension velocities at maximum were not significantly different between groups. Pelvis rotation, thorax rotation, pelvis side bend and pelvis rotation at impact were all significantly different between groups, with the Lo-HTV group being more side bent tor the trail side and more open at impact. These results suggest that world class golfers can successfully use either the low or high HTV technique for a successful swing. From an instructional perspective it is important to be aware of the body posture and wrist/forearm motion differences between the two techniques so as to be consistent when teaching either method.
ContributorsCheetham, Phillip (Author) / Hinrichs, Richard (Thesis advisor) / Ringenbach, Shannon (Committee member) / Dounskaia, Natalia (Committee member) / Crews, Debra (Committee member) / Arizona State University (Publisher)
Created2014
Description
Skeletal muscle injury may occur from repetitive short bursts of biomechanical strain that impair muscle function. Alternatively, variations of biomechanical strain such as those held for long-duration are used by clinicians to repair muscle and restore its function. Fibroblasts embedded within the unifying connective tissue of skeletal muscle experience these multiple and diverse mechanical stimuli and respond by secreting cytokines. Cytokines direct all stages of muscle regeneration including myoblasts differentiation, fusion to form myotubes, and myotube functionality. To examine how fibroblasts respond to variations in mechanical strain that may affect juxtapose muscle, a myofascial junction was bioengineered that examined the interaction between the two cell types. Fibroblasts were experimentally shown to increase myoblast differentiation, and fibroblast biomechanical strain mediated the extent to which differentiation occurred. Intereleukin-6 is a strain-regulated cytokine secreted by fibroblasts was determined to be necessary for fibroblast-mediated myoblast differentiation. Myotubes differentiated in the presence of strained fibroblasts express greater number of acetylcholine receptors, greater acetylcholine receptor sizes, and modified to be more or less sensitive to acetylcholine-induced contraction. This study provides direct evidence that strained and non-strained fibroblasts can serve as a vehicle to modify myoblast differentiation and myotube functionality. Further understanding the mechanisms regulating these processes may lead to clinical interventions that include strain-activated cellular therapies and bioengineered cell engraftment for mediating the regeneration and function of muscle in vivo.
ContributorsHicks, Michael (Author) / Standley, Paul R (Thesis advisor) / Rawls, Jeffrey (Committee member) / Lake, Douglas (Committee member) / Hinrichs, Richard (Committee member) / Arizona State University (Publisher)
Created2014
Description
Humans moving in the environment must frequently change walking speed and direction to negotiate obstacles and maintain balance. Maneuverability and stability requirements account for a significant part of daily life. While constant-average-velocity (CAV) human locomotion in walking and running has been studied extensively unsteady locomotion has received far less attention. Although some studies have described the biomechanics and neurophysiology of maneuvers, the underlying mechanisms that humans employ to control unsteady running are still not clear. My dissertation research investigated some of the biomechanical and behavioral strategies used for stable unsteady locomotion. First, I studied the behavioral level control of human sagittal plane running. I tested whether humans could control running using strategies consistent with simple and independent control laws that have been successfully used to control monopod robots. I found that humans use strategies that are consistent with the distributed feedback control strategies used by bouncing robots. Humans changed leg force rather than stance duration to control center of mass (COM) height. Humans adjusted foot placement relative to a "neutral point" to change running speed increment between consecutive flight phases, i.e. a "pogo-stick" rather than a "unicycle" strategy was adopted to change running speed. Body pitch angle was correlated by hip moments if a proportional-derivative relationship with time lags corresponding to pre-programmed reaction (87 ± 19 ms) was assumed. To better understand the mechanisms of performing successful maneuvers, I studied the functions of joints in the lower extremities to control COM speed and height. I found that during stance, the hip functioned as a power generator to change speed. The ankle switched between roles as a damper and torsional spring to contributing both to speed and elevation changes. The knee facilitated both speed and elevation control by absorbing mechanical energy, although its contribution was less than hip or ankle. Finally, I studied human turning in the horizontal plane. I used a morphological perturbation (increased body rotational inertia) to elicit compensational strategies used to control sidestep cutting turns. Humans use changes to initial body angular speed and body pre-rotation to prevent changes in braking forces.
ContributorsQiao, Mu, 1981- (Author) / Jindrich, Devin L (Thesis advisor) / Dounskaia, Natalia (Committee member) / Abbas, James (Committee member) / Hinrichs, Richard (Committee member) / Santello, Marco (Committee member) / Arizona State University (Publisher)
Created2012
Description
Many developing countries do not have health care systems that can afford technological biomedical devices or supplies to make such devices operational. To fill this void, nonprofit organizations, like Project C.U.R.E., recondition retired biomedical instrumentation so they can send medical supplies to help these developing countries. One of the issues with this is that sometimes the devices are unusable because components or expendable supplies are not available (Bhadelia). This issue has also been shown in the Impact Evaluations that Project C.U.R.E. receives from the clinics that explain the reasons why certain devices are no longer in use. That need underlies the idea on which this honors thesis has come into being. The purpose of this honors project was to create packing lists for biomedical instruments that Project C.U.R.E. recycles. This packing list would decrease the likelihood of important items being forgotten when sending devices. If an extra fuse, battery, light bulb, cuff or transducer is the difference between a functional or a nonfunctional medical device, such a list would be of benefit to Project C.U.R.E and these developing countries. In order to make this packing list, manuals for each device were used to determine what supplies were required, what was necessary for cleaning, and what supplies were desirable but functionally optional. This list was then added into a database that could be easily navigated and could help when packing up boxes for a shipment. The database also makes adding and editing the packing list simple and easy so that as Project C.U.R.E. gets more donated devices the packing list can grow.
ContributorsGraft, Kelsey Anne (Author) / Coursen, Jerry (Thesis director) / Walters, Danielle (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The Hippo signaling pathway is responsible for regulating organ size through cell proliferation, stemness, and apoptosis. Through targeting proteins Yes-associated kinase 1(YAP) and transcriptional co-activator with a PDZ-binding domain(TAZ), YAP/TAZ are unable to enter the nucleus and bind with coactivators to express target genes. To understand YAP/TAZ dynamics and its role in tumorigenesis, tissue regeneration, and tissue degeneration, a regulatory network was modeled by ordinary differential equations. Using MATLAB, the deterministic behavior of the network was observed to determine YAP/TAZ activity in different states. Performing the bifurcation analysis of the system through Oscill8, three states were identified: tumorigenic/regenerative, degenerative, and homeostatic states. Further analysis through parameter modification allowed a better understanding of which proteins can be targeted for cancer and degenerative disease.
ContributorsBarra Avila, Diego Rodrigo (Author) / Tian, Xiaojun (Thesis director) / Wang, Xiao (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor)
Created2020-05
Description
Based on James Marcia's theory, identity development in youth is the degree to which one has explored and committed to a vocation [1], [2]. During the path to an engineering identity, students will experience a crisis, when one's values and choices are examined and reevaluated, and a commitment, when the outcome of the crisis leads the student to commit to becoming an engineer. During the crisis phase, students are offered a multitude of experiences to shape their values and choices to influence commitment to becoming an engineering student. Student's identities in engineering are fostered through mentoring from industry, alumni, and peer coaching [3], [4]; experiences that emphasize awareness of the importance of professional interactions [5]; and experiences that show creativity, collaboration, and communication as crucial components to engineering. Further strategies to increase students' persistence include support in their transition to becoming an engineering student, education about professional engineers and the workplace [6], and engagement in engineering activities beyond the classroom. Though these strategies are applied to all students, there are challenges students face in confronting their current identity and beliefs before they can understand their value to society and achieve personal satisfaction. To understand student's progression in developing their engineering identity, first year engineering students were surveyed at the beginning and end of their first semester. Students were asked to rate their level of agreement with 22 statements about their engineering experience. Data included 840 cases. Items with factor loading less than 0.6 suggesting no sufficient explanation were removed in successive factor analysis to identify the four factors. Factor analysis indicated that 60.69% of the total variance was explained by the successive factors. Survey questions were categorized into three factors: engineering identity as defined by sense of belonging and self-efficacy, doubts about becoming an engineer, and exploring engineering. Statements in exploring engineering indicated student awareness, interest and enjoyment within engineering. Students were asked to think about whether they spent time learning what engineers do and participating in engineering activities. Statements about doubts about engineering to engineering indicated whether students had formed opinions about their engineering experience and had understanding about their environment. Engineering identity required thought in belonging and self-efficacy. Belonging statements called for thought about one's opinion in the importance of being an engineer, the meaning of engineering, an attachment to engineering, and self-identification as an engineer. Statements about self-efficacy required students to contemplate their personal judgement of whether they would be able to succeed and their ability to become an engineer. Effort in engineering indicated student willingness to invest time and effort and their choices and effort in their engineering discipline.
ContributorsNguyen, Amanda (Author) / Ganesh, Tirupalavanam (Thesis director) / Robinson, Carrie (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
Alzheimer’s Disease (AD) affects over 5 million individuals in the U.S. and has a direct cost estimated in excess of $200 billion per year. Broadly speaking, there are two forms of AD—early-onset, familial AD (FAD) and late-onset-sporadic AD (SAD). Animal models of AD, which rely on the overexpression of FAD-related mutations, have provided important insights into the disease. However, these models do not display important disease-related pathologies and have been limited in their ability to model the complex genetics associated with SAD.
Advances in cellular reprogramming, have enabled the generation of in vitro disease models that can be used to dissect disease mechanisms and evaluate potential therapeutics. To that end, efforts by many groups, including the Brafman laboratory, to generated patient-specific hiPSCs have demonstrated the promise of studying AD in a simplified and accessible system. However, neurons generated from these hiPSCs have shown some, but not all, of the early molecular and cellular hallmarks associated with the disease. Additionally, phenotypes and pathological hallmarks associated with later stages of the human disease have not been observed with current hiPSC-based systems. Further, disease relevant phenotypes in neurons generated from SAD hiPSCs have been highly variable or largely absent. Finally, the reprogramming process erases phenotypes associated with cellular aging and, as a result, iPSC-derived neurons more closely resemble fetal brain rather than adult brain.
It is well-established that in vivo cells reside within a complex 3-D microenvironment that plays a significant role in regulating cell behavior. Signaling and other cellular functions, such as gene expression and differentiation potential, differ in 3-D cultures compared with 2-D substrates. Nonetheless, previous studies using AD hiPSCs have relied on 2-D neuronal culture models that do not reflect the 3-D complexity of native brain tissue, and therefore, are unable to replicate all aspects of AD pathogenesis. Further, the reprogramming process erases cellular aging phenotypes. To address these limitations, this project aimed to develop bioengineering methods for the generation of 3-D organoid-based cultures that mimic in vivo cortical tissue, and to generate an inducible gene repression system to recapitulate cellular aging hallmarks.
Advances in cellular reprogramming, have enabled the generation of in vitro disease models that can be used to dissect disease mechanisms and evaluate potential therapeutics. To that end, efforts by many groups, including the Brafman laboratory, to generated patient-specific hiPSCs have demonstrated the promise of studying AD in a simplified and accessible system. However, neurons generated from these hiPSCs have shown some, but not all, of the early molecular and cellular hallmarks associated with the disease. Additionally, phenotypes and pathological hallmarks associated with later stages of the human disease have not been observed with current hiPSC-based systems. Further, disease relevant phenotypes in neurons generated from SAD hiPSCs have been highly variable or largely absent. Finally, the reprogramming process erases phenotypes associated with cellular aging and, as a result, iPSC-derived neurons more closely resemble fetal brain rather than adult brain.
It is well-established that in vivo cells reside within a complex 3-D microenvironment that plays a significant role in regulating cell behavior. Signaling and other cellular functions, such as gene expression and differentiation potential, differ in 3-D cultures compared with 2-D substrates. Nonetheless, previous studies using AD hiPSCs have relied on 2-D neuronal culture models that do not reflect the 3-D complexity of native brain tissue, and therefore, are unable to replicate all aspects of AD pathogenesis. Further, the reprogramming process erases cellular aging phenotypes. To address these limitations, this project aimed to develop bioengineering methods for the generation of 3-D organoid-based cultures that mimic in vivo cortical tissue, and to generate an inducible gene repression system to recapitulate cellular aging hallmarks.
ContributorsBounds, Lexi Rose (Author) / Brafman, David (Thesis director) / Wang, Xiao (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The combination of immunohistochemical (IHC) stainings and optical microscopy has allowed for the visualization of specific microscopic structures within tissue; however, limitations in light and antibody penetration mitigate the scale on which these images can be taken (Alshammari et al, 2016; Marx, 2014). Tissue clearing, specifically the removal of lipids to improve sample transparency, solves the former weakness well, but does not improve antibody penetration significantly (Chung et al, 2013; Treweek et al, 2015). Therefore, there is a need to equalize the maximum depth that light can pass through a section with the depth at which there is recognizable fluorescence. This is particularly important when staining blood vessels as traditional size limitations exclusively allows for cross sectional visualization. Passive CLARITY Technique (PACT) has been at the forefront of tissue clearing protocols, utilizing an acrylamide hydrogel solution to maintain structure and sodium dodecyl sulfate to wash out lipids (Tomer et al, 2014). PACT is limited in its ability to clear larger sections and is not conducive to IHC antibody diffusion (Treweek et al, 2015). In order to circumvent these drawbacks, CUBIC was developed as an alternative passive protocol, aimed at being scalable to any tissue size (Richardson, 2015; Susaki et al, 2015). This study compared the effectiveness of both protocols in high and low lipid tissues in the context of blood vessel staining efficacy. Upon initial comparison, it became apparent that there was a statistically significant difference in mean DAPI intensity at all depths, up to 200 micrometers, between CUBIC and PACT \u2014 the former showcasing brighter stainings. Moreover, it was found that PACT does not remove erythrocytes from the tissue meaning that their auto-fluorescence is seen during imaging. Therefore, for blood vessel stainings, only CUBIC was optimized and quantitatively analyzed. In both tissue conditions as well as for two stainings, DAPI and fibronectin (FNCT), optimized CUBIC demonstrated a statistically significant difference from standard CUBIC with regards to mean fluorescent intensity.
ContributorsSidhu, Gurpaul Singh (Author) / VanAuker, Michael (Thesis director) / Kodibagkar, Vikram (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
This creative project created and implemented a seven-day STEM curriculum that ultimately encouraged engagement in STEM subjects in students ages 5 through 11. The activities were incorporated into Arizona State University's Kids' Camp over the summer of 2017, every Tuesday afternoon from 4 to 6 p.m. with each activity running for roughly 40 minutes. The lesson plans were created to cover a myriad of scientific topics to account for varied student interest. The topics covered were plant biology, aerodynamics, zoology, geology, chemistry, physics, and astronomy. Each lesson was scaffolded to match the learning needs of the three age groups (5-6 year olds, 7-8 year olds, 9-11 year olds) and to encourage engagement. "Engagement" was measured by pre- and post-activity surveys approved by IRB. The surveys were in the form of statements where the children would totally agree, agree, be undecided, disagree, or totally disagree with it. To more accurately test engagement, the smiley face Likert scale was incorporated with the answer choices. After implementation of the intervention, two-tailed paired t-tests showed that student engagement significantly increased for the two lesson plans of Aerodynamics and Chemistry.
ContributorsHunt, Allison Rene (Co-author) / Belko, Sara (Co-author) / Merritt, Eileen (Thesis director) / Ankeny, Casey (Committee member) / Division of Teacher Preparation (Contributor) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Traumatic brain injury (TBI) may result in numerous pathologies that cannot currently be mitigated by clinical interventions. Stem cell therapies are widely researched to address TBI-related pathologies with limited success in pre-clinical models due to limitations in transplant survival rates. To address this issue, the use of tissue engineered scaffolds as a delivery mechanism has been explored to improve survival and engraftment rates. Previous work with hyaluronic acid \u2014 laminin (HA-Lm) gels found high viability and engraftment rates of mouse fetal derived neural progenitor/stem cells (NPSCs) cultured on the gel. Furthermore, NPSCs exposed to the HA-Lm gels exhibit increased expression of CXCR4, a critical surface receptor that promotes cell migration. We hypothesized that culturing hNPCs on the HA-Lm gel would increase CXCR4 expression, and thus enhance their ability to migrate into sites of tissue damage. In order to test this hypothesis, we designed gel scaffolds with mechanical properties that were optimized to match that of the natural extracellular matrix. A live/dead assay showed that hNPCs preferred the gel with this optimized formulation, compared to a stiffer gel that was used in the CXCR4 expression experiment. We found that there may be increased CXCR4 expression of hNPCs plated on the HA-Lm gel after 24 hours, indicating that HA-Lm gels may provide a valuable scaffold to support viability and migration of hNPCs to the injury site. Future studies aimed at verifying increased CXCR4 expression of hNPCs cultured on HA-Lm gels are necessary to determine if HA-Lm gels can provide a beneficial scaffold for stem cell engraftment therapy for treating TBI.
ContributorsHemphill, Kathryn Elizabeth (Author) / Stabenfeldt, Sarah (Thesis director) / Brafman, David (Committee member) / Harrington Bioengineering Program (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05