Matching Items (138)
Description
Telestroke networks reduce disparities in acute stroke care between metropolitan primary stroke centers and remote hospitals. Current technologies used to conduct remote patient assessments have very high start-up costs, yet they cannot consistently establish quality connection in a timely manner. Smartphgones can be used for high quality video teleconferencing (HQ-VTC). They are relatively inexpensive and widley used among healthcare providers. We aimed to study the reliability of HQ-VTC using smartphones for conducting the NIHSS. Two vascular neurologists (VNs) assessed 83 stroke patients with the NIHSS. The remote VN assessed patients using videoconferencing on a smartphone with the assistance of a bedside medical aide. The bedside VN rated patients ontemporaneously. Each VN was blinded to the other's NIHSS scores. We tested the inter-method agreement and physician satisfaction with the device. We demonstrated high total NIHSS score correlation between the methods (r=0.941, p<0.001). The mean total NIHSS scores for bedside and remote assessments were 7.3 plus or minus 7.9 and 6.7 plus or minus 7.6 with ranges of 0-30 and 0-37, respectively. Seven NIHSS categories had significantly high agreement beyond chance: LOC-questions, LOC-commands, visual fields, motor left arm, motor right arm, motor left leg, motor right leg; seven categories had moderate agreement: LOC-consciousness, best gaze, facial palsy, sensory, best language, dysarthria, extinction/inattention; one category had poor agreement: ataxia. There was high physician satisfaction with the device. The VNs rated 96% of the assessments as good or very good for "image quality," "sound quality," "ease of use," and "ability to assess subject using NIHSS," and 84% of the assesssments as good or very good for "reception in hospital." The smartphones with HQ-VTC is reliable, easy to use, and affordable for telestroke NIHSS administration. This device has high physician satisfaction. With the variety of smartphones and professional medical applications available today, the telestroke practitioner has all the tools necessary for fast clinical decision-makingby accessing electronic medial records, viewing images, and tracking patient vitals.
ContributorsVegunta, Sravanthi (Author) / Demaerschalk, Bart (Thesis director) / Santello, Marco (Committee member) / Hurlbut, Ben (Committee member) / Barrett, The Honors College (Contributor)
Created2012-05
Description
In Apis mellifera, gustatory responsiveness to sucrose is a good indicator of learning ability \u2014 in that individuals with high sucrose responsiveness will typically form faster, longer-lasting associations with conditioned stimulus than individuals with a low sucrose responsiveness. The purpose of this study was to determine whether experience with olfactory conditioning had lasting effects on gustatory responsiveness. Groups were placed in an environment that would facilitate association of an odor to a sucrose reward, tested for retention, then tested for gustatory responsiveness. Control groups underwent the same testing schedule, but were not exposed to odor in the first environment. There was no significant difference in gustatory responsiveness between the two groups. Mann-Whitney tests were used to analyze the results, and though the mean GRS score was lower among the treatment group there was no significant trend, possibly due to small sample sizes.
ContributorsSeemann, J. H. (Author) / Amdam, Gro (Thesis director) / Smith, Brian (Committee member) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Genetic counseling is a medical field that was established in the 1970s, but whose demand is now growing exponentially due to modern genetic technology. We now have the ability to look into the human genetic code, detect the genotype of individuals, and use this knowledge to our benefit. However, Genetic testing results in a need for new ethical boundaries to be drawn. The idea of the "best possible conditions" of conceiving a child and whether this child has a right to not know are the two major ethical issues that will be focused on in order to analyze the ethical boundary that needs to be drawn for genetic counseling. In order to analyze these ethical issues, a focus group of Arizona State University students was organized. After producing results for the focus group, there are no true conclusions that can be drawn that applied to all of society. The focus group sample size was too small to produce a broad range of results and the participants were all Arizona State University Undergraduate students. However, it did become apparent that knowledge on these ethical issues is crucial in order to ensure they do not hinder the field of genetic counseling. It is predicted that in order to have the best outcome for the field of genetic counseling, genetic counselors themselves need to draw the ethical boundaries for the issues studied.
ContributorsBarker, Samantha (Author) / Amdam, Gro (Thesis director) / Bang, Christofer (Committee member) / Wang, Ying (Committee member) / Barrett, The Honors College (Contributor)
Created2016-05
Description
The purpose of this paper was to systematically review current literature regarding the effect of hand splints on aesthetic outcomes for individuals with acquired hand deformities. Hand splints vary in form and function, and are used to maintain or ameliorate hand function and aesthetics. A literature search was performed on peer-reviewed publications that used splinting as an intervention for conservative hand improvement. Evidence from ten randomized clinical trials (published from 2003 to 2015) was evaluated for aesthetic improvement among a total of 659 subjects. Cosmetic outcomes were analyzed by a change in angle measurements, such as extensor lag, ulnar deviation, and passive and active range of motion. Of these ten studies, five focused on hand deformities caused by neurological impairment, while the other five measured those with musculoskeletal complications. Only two of the ten studies concluded that splinting could aesthetically improve the hands, and only one of these reporting statistical significance in its data. The data was not only limited in quantity, but was presented in heterogeneous formats. There was an extensive variation in measured outcomes, intervention protocols, follow-up times, and many other aspects of the studies; this dissimilarity led to difficulty in performing a systematic assessment. The majority of evidence concludes that splinting does not improve the appearance of deformities, however none directly investigated this measure. Therefore, further RCTs that include measurements of cosmetic traits are necessary to better quantify the effect of splinting for management of hand deformities. This review was the first of its kind to evaluate the correction of hand deformities using splints as an intervention.
ContributorsVale, Nicholas Marshall (Author) / Santello, Marco (Thesis director) / Skiba, Jeffry (Committee member) / Harrington Bioengineering Program (Contributor, Contributor) / Barrett, The Honors College (Contributor, Contributor) / School of Biological and Health Systems Engineering (Contributor)
Created2017-05
Description
Understanding why animals form social groups is a fundamental aim of sociobiology. To date, the field has been dominated by studies of kin groups, which have emphasized indirect fitness benefits as key drivers of grouping among relatives. Nevertheless, many animal groups are comprised of unrelated individuals. These cases provide unique opportunities to illuminate drivers of social evolution beyond indirect fitness, especially ecological factors. This dissertation combines behavioral, physiological, and ecological approaches to explore the conditions that favor group formation among non-kin, using as a model the facultatively social carpenter bee, Xylocopa sonorina. Using behavioral and genetic techniques, I found that nestmates in this species are often unrelated, and that non-kin groups form following extensive inter-nest migration.Group living may arise as a strategy to mitigate constraints on available breeding space. To test the hypothesis that nest construction is prohibitively costly for carpenter bees, I measured metabolic rates of excavating bees and used imaging techniques to quantify nest volumes. From these measurements, I found that nest construction is highly energetically costly, and that bees who inherit nests through social queuing experience substantial energetic savings. These costs are exacerbated by limitations on the reuse of existing nests. Using repeated CT scans of nesting logs, I examined changes in nest architecture over time and found that repeatedly inherited tunnels become indefensible to intruders, and are subsequently abandoned. Together, these factors underlie intense competition over available breeding space. The imaging analysis of nesting logs additionally revealed strong seasonal effects on social strategy, with social nesting dominating during winter. To test the hypothesis that winter social nesting arises from intrinsic physiological advantages of grouping, I experimentally manipulated social strategy in overwintering bees. I found that social bees conserve heat and body mass better than solitary bees, suggesting fitness benefits to grouping in cold, resource-scarce conditions. Together, these results suggest that grouping in X. sonorina arises from dynamic strategies to maximize direct fitness in response to harsh and/or competitive conditions. These studies provide empirical insights into the ecological conditions that favor non-kin grouping, and emphasize the importance of ecology in shaping sociality at its evolutionary origins.
ContributorsOstwald, Madeleine (Author) / Fewell, Jennifer H (Thesis advisor) / Amdam, Gro (Committee member) / Harrison, Jon (Committee member) / Pratt, Stephen (Committee member) / Kapheim, Karen (Committee member) / Arizona State University (Publisher)
Created2022
Description
Although previous studies have elucidated the role of position feedback in the regulation of movement, the specific contribution of Golgi tendon organs (GTO) in force feedback, especially in stabilizing voluntary limb movements, has remained theoretical due to limitations in experimental techniques. This study aims to establish force feedback regulation mediated by GTO afferent signals in two phases. The first phase of this study consisted of simulations using a neuromusculoskeletal model of the monoarticular elbow flexor (MEF) muscle group, assess the impact of force feedback in maintaining steady state interaction forces against variable environmental stiffness. Three models were trained to accurately reach an interaction force of 40N, 50N and 60N respectively, using a fixed stiffness level. Next, the environment stiffness was switched between untrained levels for open loop (OL) and closed loop (CL) variants of the same model. Results showed that compared to OL, CL showed decreased force deviations by 10.43%, 12.11% and 13.02% for each of the models. Most importantly, it is also observed that in the absence of force feedback, environment stiffness is found to have an effect on the interaction force. In the second phase, human subjects were engaged in experiments utilizing an instrumented elbow exoskeleton that applied loads to the MEF muscle group, closely mimicking the simulation conditions. The experiments consisted of reference, blind and catch trial types, and 3 stiffness levels. Subjects were first trained to reach for a predetermined target force. During catch trials, stiffness levels were randomized between reaches. Responses obtained from these experiments showed that subjects were able to regulate forces with no significant effects of trial type or stiffness level. Since experimental results align closely with that of closed loop model simulations, the presence of force feedback mechanisms mediated by GTO within the human neuromuscular system is established. This study not only unveils the critical involvement of GTO in force feedback but also emphasizes the importance of understanding these mechanisms for developing advanced neuroprosthetics and rehabilitation strategies, shedding light on the intricate interplay between sensory inputs and motor responses in human proprioception.
ContributorsAbishek, Kevin (Author) / Lee, Hyunglae (Thesis advisor) / Buneo, Christopher (Committee member) / Santello, Marco (Committee member) / Arizona State University (Publisher)
Created2023
Description
Speciation, or the process by which one population diverges into multiple populations that can no longer interbreed with each other, has brought about the incredible diversity of life. Mechanisms underlying this process can be more visible in the early stages of the speciation process. The mechanisms that restrict gene flow in highly mobile species with no absolute barriers to dispersal, especially marine species, are understudied. Similarly, human impacts are reshaping ecosystems globally, and we are only just beginning to understand the implications of these rapid changes on evolutionary processes. In this dissertation, I investigate patterns of speciation and evolution in two avian clades: a genus of widespread tropical seabirds (boobies, genus Sula), and two congeneric passerine species in an urban environment (cardinals, genus Cardinalis). First, I explore the prevalence of gene flow across land barriers within species and between sympatric species in boobies. I found widespread evidence of gene flow over all land barriers and between 3 species pairs. Next, I compared the effects of urbanization on the spatial distributions of two cardinal species, pyrrhuloxia (Cardinalis sinuatus) and northern cardinals (Cardinalis cardinalis), in Tucson, Arizona. I found that urbanization has different effects on the spatial distributions of two closely related species that share a similar environmental niche, and I identified environmental variables that might be driving this difference. Then I tested for effects of urbanization on color and size traits of these two cardinal species. In both of these species, urbanization has altered traits involved in signaling, heat tolerance, foraging, and maneuverability. Finally, I tested for evidence of selection on the urban populations of both cardinal species and found evidence of both parallel selection and introgression between the species, as well as selection on different genes in each species. The functions of the genes that experienced positive selection suggest that light at night, energetics, and air pollution may have acted as strong selective pressures on these species in the past. Overall, my dissertation emphasizes the role of introgression in the speciation process, identifies environmental stressors faced by wildlife in urban environments, and characterizes their evolutionary responses to those stressors.
ContributorsJackson, Daniel Nelson (Author) / McGraw, Kevin J (Thesis advisor) / Amdam, Gro (Committee member) / Sweazea, Karen (Committee member) / Taylor, Scott (Committee member) / Arizona State University (Publisher)
Created2023
Description
The objective of this meta-analysis is to holistically evaluate the existing body of literature on the anti-neoplastic potential of snake and bee venom. In recent years, venom-based therapeutics have emerged as a promising solution for combating cancer, generating a notable rise in publications on the topic. Consequently, this comprehensive study aims to assess the current state of research and identify trends that may guide future investigations. Following the guidelines established by PRISMA, a total sample of 26 research papers were extracted from the electronic databases, PubMed and Scopus. These papers were categorized based on their publication dates, and research questions were formulated regarding three main topics: venom type, cancer-targeting mechanism, and cancer type. Statistical analysis of the research questions was performed using 2x2 contingency tables for a chi-square test. The results of the analysis reveal a statistically significant increase in publications focused on cell death mechanisms and breast cancer in recent years. This increase in publications reflects a growing interest in the potential for venom to induce apoptosis in cancer cells and target the unique biological properties of breast cancer. Overall, this meta-analysis offers insight into the evolving sphere of venom-based cancer research, providing a glimpse into the potential trajectory of this field.
ContributorsHolder, Marina (Author) / Amdam, Gro (Thesis director) / Mana, Miyeko (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Economics Program in CLAS (Contributor)
Created2023-12
Description
A current thrust in neurorehabilitation research involves exogenous neuromodulation of peripheral nerves to enhance neuroplasticity and maximize recovery of function. This dissertation presents the results of four experiments aimed at assessing the effects of trigeminal nerve stimulation (TNS) and occipital nerve stimulation (ONS) on motor learning, which was behaviorally characterized using an upper extremity visuomotor adaptation paradigm. In Aim 1a, the effects of offline TNS using clinically tested frequencies (120 and 60 Hz) were characterized. Sixty-three participants (22.75±4.6 y/o), performed a visuomotor rotation task and received TNS before encountering rotation of hand visual feedback. In Aim 1b, TNS at 3 kHz, which has been shown to be more tolerable at higher current intensities, was evaluated in 42 additional subjects (23.4±4.6 y/o). Results indicated that 3 kHz stimulation accelerated learning while 60 Hz stimulation slowed learning, suggesting a frequency-dependent effect on learning. In Aim 2, the effect of online TNS using 120 and 60 Hz were characterized to determine if this protocol would deliver better outcomes. Sixty-three participants (23.2±3.9 y/o) received either TNS or sham concurrently with perturbed visual feedback. Results showed no significant differences among groups. However, a cross-study comparison of results obtained with 60 Hz offline TNS showed a statistically significant improvement in learning rates with online stimulation relative to offline, suggesting a timing-dependent effect on learning. In Aim 3, TNS and ONS were compared using the best protocol from previous aims (offline 3 kHz). Additionally, concurrent stimulation of both nerves was explored to look for potential synergistic effects. Eighty-four participants (22.9±3.2 y/o) were assigned to one of four groups: TNS, ONS, TNS+ONS, and sham. Visual inspection of learning curves revealed that the ONS group demonstrated the fastest learning among groups. However, statistical analyses did not confirm this observation. In addition, the TNS+ONS group appeared to learn faster than the sham and TNS groups but slower than the ONS only group, suggesting no synergistic effects using this protocol, as initially hypothesized.
The results provide new information on the potential use of TNS and ONS in neurorehabilitation and performance enhancement in the motor domain.
ContributorsArias, Diego (Author) / Buneo, Christopher (Thesis advisor) / Schaefer, Sydney (Committee member) / Helms-Tillery, Stephen (Committee member) / Santello, Marco (Committee member) / Kleim, Jeffrey (Committee member) / Arizona State University (Publisher)
Created2023
Description
Multisensory integration is the process by which information from different sensory modalities is integrated by the nervous system. This process is important not only from a basic science perspective but also for translational reasons, e.g., for the development of closed-loop neural prosthetic systems. A mixed virtual reality platform was developed to study the neural mechanisms of multisensory integration for the upper limb during motor planning. The platform allows for selection of different arms and manipulation of the locations of physical and virtual target cues in the environment. The system was tested with two non-human primates (NHP) trained to reach to multiple virtual targets. Arm kinematic data as well as neural spiking data from primary motor (M1) and dorsal premotor cortex (PMd) were collected. The task involved manipulating visual information about initial arm position by rendering the virtual avatar arm in either its actual position (veridical (V) condition) or in a different shifted (e.g., small vs large shifts) position (perturbed (P) condition) prior to movement. Tactile feedback was modulated in blocks by placing or removing the physical start cue on the table (tactile (T), and no-tactile (NT) conditions, respectively). Behaviorally, errors in initial movement direction were larger when the physical start cue was absent. Slightly larger directional errors were found in the P condition compared to the V condition for some movement directions. Both effects were consistent with the idea that erroneous or reduced information about initial hand location led to movement direction-dependent reach planning errors. Neural correlates of these behavioral effects were probed using population decoding techniques. For small shifts in the visual position of the arm, no differences in decoding accuracy between the T and NT conditions were observed in either M1 or PMd. However, for larger visual shifts, decoding accuracy decreased in the NT condition, but only in PMd. Thus, activity in PMd, but not M1, may reflect the uncertainty in reach planning that results when sensory cues regarding initial hand position are erroneous or absent.
ContributorsPhataraphruk, Preyaporn Kris (Author) / Buneo, Christopher A (Thesis advisor) / Zhou, Yi (Committee member) / Helms Tillery, Steve (Committee member) / Greger, Bradley (Committee member) / Santello, Marco (Committee member) / Arizona State University (Publisher)
Created2023