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Methods for Measuring, Segmenting, and Analyzing Human Functional Upper Extremity Movements
Get PDFThe ability to reach and grasp objects is a fundamental human movement – the other two being postural control and ambulation – that for many people allows for independent living. Consider the activity of brushing one’s teeth in the morning – picking up the toothbrush, taking the cap off the toothpaste tube, putting toothpaste onto the toothbrush, replacing the cap, and brushing one’s teeth – which requires the complex coordination of the visual, somatosensory, and motor systems. Postural control is also used for reaching and grasping, requiring coordination with the vestibular system. Any disruption to these systems and pathways, such as due to traumatic injuries, neurodegenerative diseases, or non-traumatic brain injuries (e.g., stroke), can manifest in the inability to perform activities of daily living and the loss of independence. A comprehensive plan of care for these individuals often includes physical rehabilitation focused on improving mobility and strength, reducing pain, and helping these individuals live more independently. Similar to how a primary care physician may order a lipid panel at regular visits to check cholesterol levels and inform whether medication or lifestyle modifications are needed, physical rehabilitation specialists (e.g., physical therapists, occupational therapists, physiatrists, etc.) need measures of functional ability to inform clinical treatment plans. Recently, movement scientists and clinicians have identified the analysis of functional upper extremity movement kinematics as a promising approach to providing quantitative and objective measures of functional ability. These kinematic-based measures could supplement widely used functional measures that do not use upper extremity kinematics, such as the Fugl-Meyer Assessment of motor recovery after stroke. However, kinematic-based measures are currently not being used widely due to issues associated with cost and the need for further methodological validation. The focus of this dissertation is on developing computational methods that can reduce the costs and burden associated with the kinematic analysis workflow, where the goal is to help make upper extremity kinematic assessments easier to perform and more accessible. This dissertation makes contributions to multiple components of the kinematics analysis workflow – measurement, movement segmentation, description and analysis, and assessment and interpretation – and is informed by an interdisciplinary literature review we performed. For kinematic measurements, this dissertation proposes a method to measure upper extremity kinematics directly from 3D point clouds using RGB-D videos of the upper extremity while moving. For movement segmentation, this dissertation evaluates methods for automating the currently difficult and manually intensive segmentation of the reaching and targeting motion primitive phases of reach-to-point and reach-to-grasp motions. Automated movement segmentation algorithms are needed because current workflows, which are time-consuming and mostly used in the laboratory, will not scale to more widespread use of kinematic analyses in the clinic. Additionally, this dissertation proposes a method for indicating when there are potentially questionable segmentation results that require human review, where movement scientists currently review all segmentation results. For analysis and description, this dissertation analyzes functional motions in a haptic virtual environment and suggests more informative measures of functional movement space efficiency to quantify fine motor skill. The results of the literature review and proposed methods in this dissertation suggest that incorporating automation into the currently time intensive data processing components of the kinematics analysis workflow, specifically measurement and segmentation, is a promising area for computational researchers to address
One Health Approach to Zoonotic Disease Surveillance Utilizing Watering Hole Samples in Laikipia County, Kenya
Get PDFEmerging and re-emerging pathogens and more specifically, water-borne pathogens continue to be a burden globally. In East Africa, water-borne infectious diseases include cholera, cryptosporidiosis, giardia, hepatitis A and E, leptospirosis, schistosomiasis, and typhoid. Watering holes are an understudied environment for surveillance, in Laikipia County, Kenya. These locations provide a unique perspective as it is a shared environment between animals, livestock, and humans and allow the ability to conduct pathogen surveillance under a One Health framework. Throughout Laikipia County, 10 watering holes were sampled. Within Kenya, there have been outbreaks of cholera, schistosomiasis is considered endemic, and leptospirosis has a high global burden (Chadeka et al., 2019). To our knowledge, there has not been a study in Laikipia County studying water samples from watering holes for zoonotic infectious diseases. Of increasing concern, due to climate change, there has been a scarcity of resources, and certain watering holes are now almost or completely empty during portions of the year. In addition, there has been an ongoing drought which has led to an increase in the shared usage of watering holes and made water a valuable resource amongst humans and animals. From May 2020 until March 2022, 122 pooled water samples were collected from 10 watering holes within Laikipia County. The samples were processed and sequenced using a Mk1C MinION, with output sequences analyzed through a data pipeline. Partial reads from the following microorganisms were detected: Acanthamoeba castellanii, Aeromonas veronii, Brevibacillus brevis, Gardnerella vaginalis, Legionella pneumophila, Orientia tsutsugamushi, Plesiomonas shigelloides, Staphylococcus aureus, Staphylococcus capitis, Staphylococcus epidermidis, Staphylococcus haemolyticus and Vibrio cholerae. Samples were further examined for potential contigs, many of the samples had limited mapping to the reference genome, often with no coverage overlapping. These findings highlight the potential uses of metagenomics for environmental surveillance and the need for more studies conducting work with environmental DNA and metagenomics. Additionally, this thesis starts to contribute towards a larger conversation within science about the reliability and confidence or working with and analyzing genetic data
The Effect of Distractor Processing on the Distribution of Visual Attention
Get PDFThe distribution of visuospatial attention is integral for performing everyday tasks such as driving safely, finding an object on a cluttered desk, or identifying a friend in a crowd. There has been extensive research using search tasks to investigate the properties of visuospatial attention relating to phenomena such as scaling attention and surround suppression, although our understanding of how attention is distributed in visual search is still incomplete. A greater understanding of the enhancements and distortions imposed by visuospatial attention on target processing could be used to improve human performance on attentionally demanding tasks. To this end, we examined across three studies how various parameters that were designed to alter task difficulty modulate the distribution of visual attention and the suppression of distractor information surrounding a target of search. In Study 1, we investigated whether healthy older individuals would show a predicted heightened surround suppression compared to young individuals during search for a target in a closely spaced two-dimensional array of distractors. A probe was flashed at varying distances from the target to map the attentional distribution. For target sensitivity, a marginal two-way interaction between age group and probe-target distance was found. Exploratory post-hoc pairwise comparisons showed (weak) evidence for stronger surround suppression two degrees from the target location in the old group, with enhanced attention at the target and rebound of attention outside of the suppressed region. The young group showed a more shallow distribution, with attention focused at the target and decreasing attention as the probe appeared farther from the target. Little is known about the effects of aging on surround suppression, and this work sheds light on how age-related perceptual declines may be associated with an increased reliance on spatial cues. In Study 2, we investigated the impact of task difficulty on surround suppression by manipulating the shape of distractors to be more similar to the target. Using a similar search task to Study 1, we predicted that greater discrimination difficulty would elicit heightened surround suppression. A significant two-way interaction between difficulty and probe-target distance was found. The results showed stronger surround suppression between one to two degrees from the target when distractors were the most similar to the target (i.e. most difficult condition). Together, Studies 1 and 2 show suppression in the presence of greater task difficulty, either through age-related perceptual declines or target-distractor similarity, and at the same approximate distance between one to two degrees from the target. However, there still remains the question of how distractors with a more or less similar orientation to that of the target during visual search modulates surround suppression. In Study 3, we investigated how task difficulty in the context of varying a feature (i.e. orientation) of a nearby distractor modulates surround suppression. We used a different search task that featured a radial array and manipulated the orientation of a single distractor near the target to be more or less similar in orientation to the target. We predicted a nearby distractor oriented similarly to the target would enhance suppression around the target. A significant two-way interaction between difficulty and probe-target distance was found. The results showed that when a nearby distractor was less similar in orientation to the target, there was a distribution of attention that resembled surround suppression. When the adjacent distractor was more similar in orientation to the target, attention was tightly focused over the target. These results contradicted our hypothesis. This could be due to a need to include both the target and distractor in the focus of attention in order to discriminate the target. That we observed less attention directed to the less similar distractor could be due to its greater similarity to the other distractors in the array. In sum, each of these studies revealed dynamic changes in the distribution of visuospatial attention in response to varying requirements for suppressing distractors. Studies 1 and 2 offered distinct lines of evidence supporting the role of task difficulty in eliciting surround suppression, while Study 3 provided insights into contextual effects on the magnitude of surround suppression, dependent on the local nature of the effect of distractor properties in forming an environment for the target. These studies collectively highlight the dynamic nature of attentional distribution in response to the need to discriminate the target and suppress distractors, and show the existence of three fundamental aspects of visuospatial attention: control of the focus and its resistance to task demands; control of the suppressive annulus and its sensitivity to distractors; and control of the rebound from the suppression which appears to be separate from the control of the suppressive annulus but perhaps also sensitive to distractors
Praying the Holy War: The Bishop of Quebec, the Mandements, and the Seven Years’ War in New France
Get PDFThere are many starting points for a conversation about religious violence in the Seven Years’ War. A sermon by Theodorus Frielinghuysen II, the pastor of the Reformed Dutch Church in Albany, entitled “Wars and Rumors of Wars, Heavens Decree over the World. A Sermon Preached in the Camp of the New-England Forces. On Occasion of the Expedition to remove the Encroachments of the French, on his Majesty’s Dominions in North-America,” remains one of the clearest exemplars of the genre.1 The sermon was printed in 1755 and distributed at the start of the Seven Years’ War in the British colonies, when things were going very badly for the British. He opened it with Matthew 24:6, from the “Little Apocalypse,” “And ye shall hear of Wars, and Rumors of Wars: See that ye be not troubled; for all these Things must come to pass, but the End is not yet.”
Essays on the Political Economy of Central Banking
Get PDFThis three-chapter dissertation analyzes the political economy of central banking by examining the Bank of Amsterdam and the Federal Reserve’s Municipal Liquidity Facility as two separate case studies. The first chapter, titled “Full Reserves, Fractional Practices, and Public Subsidies: The Case of the Bank of Amsterdam,” examines the political economy of the Bank of Amsterdam as a historical case study of a full reserve bank operating in practice. Many economists cite the Bank of Amsterdam as a proof-of-concept example of the feasibility of a full reserve banking system that is grounded in laissez faire principles. However, closer examination of the Bank’s full history finds that the Bank did not live up to its reputation as a full reserve bank, nor did the Bank’s regulatory environment conform with laissez faire banking principles. Even with the assistance of subsidies and privileges from the city of Amsterdam, the Bank of Amsterdam failed to maintain its full reserve requirement. Therefore, economists who advocate for full reserve banking on laissez faire grounds should reconsider using it as a prime example of their ideal system. The second and third chapters examine the Federal Reserve’s Municipal Liquidity Facility as a case study of the entangled political economy between subnational governments and a nation’s central bank. The Municipal Liquidity Facility was instituted during the COVID-19 pandemic to support the municipal bond market and to provide liquidity for states, municipalities, and other governmental entities in the United States. Many of these subnational entities, having issued large amounts of pre-pandemic outstanding public debt, were already in strained fiscal condition prior to the pandemic. The second chapter, titled, “The Municipal Liquidity Facility and the Tragedy of the Monetary Commons,” examines how this subsidized lending facility creates a common-pool resource that distributes economic rents to politically connected subnational governmental entities via the Federal Reserve. It incentivizes these entities to entangle themselves with the federal government and the Federal Reserve for ongoing subsidies. The third and final chapter, titled “Moral Hazard, Interjurisdictional Competition, and the Municipal Liquidity Facility,” examines how this lending facility creates a moral hazard that enables heavily indebted states and municipalities to continue running unsustainable budgets to fund non-pandemic-related fiscal needs. It also undermines competitive federalism in the United States by bailing out profligate state and local governmental entities at the expense of more soundly run states and localities
Resisting Through 2020: Political Strategies of Black Women Receiving Government Assistance In the U.S. During Floyd, Trump, and COVID-19
Get PDFThe year 2020 in the United States is one that TIME magazine mentioned “will go down in history books”. Edits and revisions have already occurred in scholarly publications to include the historic events that shaped the lives of so many. On February 11, 2020, the World Health Organization announced coronavirus (COVID-19), May 30, 2020, the conversation about systemic racism extended beyond COVID-19 as the world watched the murder of George Floyd by police officers in Minneapolis, Minnesota, all while Donald Trump served as president. This work focuses on Black women receiving government assistance in the U.S. and looks at the ways these three factors, Trump/Trump’s Administration, COVID-19, and what scholars have called “The Summer of Racial Reckoning”, impacted how women thought about their bodies, reproduction, and motherhood while also addressing the chronic stressors that occurred in their everyday lives. However, instead of focusing the research question solely on the negative impacts on these women, this qualitative work uses a Black Feminist Intersectional methodology to center their resistance and social transformation. Through interviews and Isoke’s bottom-up approach to structural intersectionality, this project spotlights the everyday resistance strategies: faith, sacrifice, centering self, and community support, used by these women to persist through the systemic oppressions these factors had on their bodies. Persistence, resistance, and dissent are then defined as emic categories to show how the strategies implemented by Black women partook in all of them; concluding that Black women receiving government assistance in the U.S. spent their lives consistently participating in politics
Neighborhood Poverty and Violence, School Readiness, and Third Grade Academic Achievement
Get PDFNeighborhood disadvantage and crime have been found to be predictive of poorer academic outcomes. Children in disadvantaged neighborhoods and those with high crime levels have been found to perform worse academically than those from more affluent or safer communities. This thesis investigated the role of neighborhood crime and economic disadvantage in children’s early (pre-kindergarten) and later (3rd grade) academic achievement. Moreover, I explored the role of school readiness as a mediator between neighborhoods and academic achievement. This thesis used a subsample of 3,350 children from the Miami School Readiness Project (MSRP), which followed children attending subsidized childcare services at age four between 2002 and 2007 in Miami-Dade County, Florida. The MSRP provided data on child and family demographics, school readiness, and 3rd-grade outcomes. Factor analyses were used to create a residential neighborhood disadvantage measure using data from the 2000 Census and a single indicator of crime using data from the National Neighborhood Crime Study for each of the 308 identified census tracts. Two-level models that nested children in their census tracts and added neighborhood characteristics to the second level alongside child characteristics that were present at both levels were used to address research questions. Results indicated that neighborhood disadvantage significantly predicted cognitive abilities at age four, third-grade math achievement, and GPA. Unexpectedly, neighborhood crime was a positive predictor of reading test scores and GPA. Cognitive skills at age four mediated the relationship between neighborhood disadvantage and math achievement. The implications and limitations of these results are discussed
Analysis of the Exoplanet Host Star Candidacy of TOI 5938.01
Get PDFThis study aimed to confirm if there is an exoplanet for TOI 5938.01. This goal was accomplished by using AstroImageJ to run multi-aperture photometry to generate a light curve for the TOI and then analyzing the light curve for the results. Through the light curve generated, I was able to confirm that TOI 5938.01 has a planet. This result is important for future missions, as the list of known exoplanets will have expanded with my analysis
Blood, Soil, Root, and Branch: Climate Change, Gender, and the Future of Mass Atrocity Prevention
No full textThis work is embargoed by the author and will not be publicly available until August 2028.As droughts, floods, and more intense and frequent weather disasters affect how people interact with and predict their water, food, and energy resources, the way we conceptualize the causes and prevention of identity-based conflict will also have to evolve. This dissertation introduces a new atrocity prevention concept—ecofeminist atrocity prevention—as a lens for analyzing the infrastructure of structural violence and identifying avenues for mitigation. This dissertation seeks to understand a gender informed environmental method of structural atrocity prevention, in the context of anthropogenic climate change. By recognizing how natural resources have played integral parts in previous genocides, as well as the ongoing issues of access and control due to structural violence, the need for integration of the effects of climate change into current and future atrocity prevention methods becomes apparent. This dissertation highlights that as the primary managers of food, water, and energy resources globally, women are one of the most vulnerable populations to the effects of climate change, and also the most essential leaders of climate adaptation and mitigation. This research utilizes a case study of West Nile, Uganda, where a history of structural violence and the tangible effects of climate change are already posing challenges to their future.2028-08-1
Development and Evaluation of North America Ensemble Forecasts of Wildfires and Dust Storms
Get PDFWildfires and dust storms are two major emission sources of aerosols in the atmosphere, exerting myriad effects on air quality, climate, and human health. Predicting wildfires and dust storms is challenging due to large uncertainties in the inputs and representation of chemical and physical processes in the atmospheric models. Ensemble forecasting has been proposed to improve the predictability of wildfire and dust aerosols. This work presents the development and evaluation of a multi-model ensemble forecast system of wildfire and dust air pollution over North America, leveraging research and operational forecasts operated by George Mason University (GMU) and three U.S. federal agencies: National Oceanic and Atmospheric Administration (NOAA), National Aerospace and Space Agency (NASA), and Naval Research Laboratory (NRL). The ensemble members include three regional models (GMU CMAQ, NOAA NACC-CMAQ, and NOAA HYSPLIT), three global models (NOAA GEFS-Aerosols, NASA GEOS-5, and NRL NAAPS), and one global ensemble (ICAP-MME). Performance of the ensemble forecast was evaluated with aerosol optical depth (AOD) products from MODIS MAIAC, VIIRSSNPP enhanced Dark Target (DT) and Deep Blue (DB), and surface PM2.5 (fine particle) from the AirNow ground network during the 2020 Gigafire events (August-September
2020) in the western United States and the 2021 Spring Dust Season in the Chihuahuan Desert. For the wildfire ensemble, the results showed that, compared to the individual models, the ensemble mean significantly reduced the biases in the wildfire air pollution forecasts and produced more persistently reliable forecasts during extreme fire events. For AOD forecasts, the ensemble mean was able to improve model performance, such as increasing the correlation to 0.57 (0.62) from a range of 0.30-0.53 (0.35-0.56) by individual models when compared to the VIIRS (MAIAC). The ensemble mean also yields the best (second best) overall RANK, a composite indicator representing four statistical metrics (correlation, fractional bias, area hit rate, and false alarm ratio) compared to VIIRS (MAIAC). For the forecast of surface PM2.5 concentration, the ensemble mean demonstrated better performance than any single model with the strongest correlation (0.60 vs 0.43-0.54 by individual models), lowest fractional bias (0.54 vs 0.55-1.32), highest hit rate (87% vs 40%-82%), and highest RANK (2.83 vs 2.40-
2.81), when compared to the AirNow observations. Finally, the ensemble shows the potential to provide a suitable exceedance probability forecast during wildfires with the lowest area false alarm ratio (1.52%) achieved by the ensemble probability of 100%.
For the dust ensemble, the ensemble mean moderately reduced biases in the dust air pollution forecasts and provided fairly reliable AOD and PM2.5 forecasts during extreme dust storms compared to the individual models. For AOD forecasts, the ensemble mean improved forecasting performance less successfully than expected, as demonstrated by slightly decreasing mean bias to 0.01 (0.07) based on VIIRS DT (VIIRS DB), increasing correlation to 0.32 at the low level highest from a range of 0.09-0.31 (VIIRS DB), and yielding the third best overall RANK compared to VIIRS DT and DB. For surface PM2.5 forecasts, the ensemble mean underperformed with a slightly reduced mean bias (3.14), moderately improved low-level correlation (0.40), low area hit rates (15%), and the third best RANK. The ensemble was able to provide only low-medium (20-60%) exceedance probability forecasts during dust events. In addition, the low correlations and large biases of the dust ensemble forecasts during the extreme dust episodes indicate worse performance compared to that of wildfire ensemble forecasts due to larger uncertainties in predicting dust emission, dispersion, and removal. The thesis findings highlight that using the ensemble approach can reduce biases in air pollution forecasts and reasonably improve the model predictability during extreme events such as wildfires and dust storms. The proposed ensemble exceedance probability forecast can be further applied to early warnings of severe air pollution episodes during wildfires and dust storms. However, the reliability of the ensemble forecast is still subject to types of extreme events due to different emission sources as well as initial and boundary meteorological conditions