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Nutritional Adequacy of Dietary Intake Among College Students Who Follow a Vegetarian Diet as Compared to Non-Vegetarian Students
Get PDFState Gross Domestic Product Predictions using Hierarchical Clustering and Multivariate Time Series
Get PDFThis research was conducted to determine the weight certain taxes and expenditures have over state Gross Domestic Product(GDP) as well as how accurately these predictors can predict future GDP. The motivation behind this project comes from a desire to find the most efficient way to increase the GDP of states with poorer economies. This will improve the quality of life of citizens of these states. To come to a consensus as to what predictors are most influential, Hierarchical Clustering will be used to split the states into four groups. The average of each tax, expenditure and GDP from 2015-2020 will be calculated for each group. This data along with Time Series Forecasting Analysis will indicate which data point is most influential for each group. The Time Series Forecasting will result in an equation that can be used to predict the GDP of 2021 utilizing the GDP of 2020. I will then compare the predicted GDP to the actual GDP for each group. This will lead to future works where I will allow for more predictors and groupings to make more accurate predictions
Effect of Endogenous and Exogenous Agents in Platelet Adhesion
Get PDFPlatelet adhesion is regulated by both activators, such as adenosine diphosphate, and inhibitors, such as nitric oxide (NO). Both agents are released on platelet activation, so that platelets initiate both positive and negative feedback systems. In vivo platelet adhesion models generally consider the effects of platelet activators and inhibitors separately. The goal of this study was to create an environment in which interplay between positive and negative feedback can be observed together and in which the roles of endogenous and exogenous platelet activators are distinguishable. The results are expected to be applicable to the design of stents, which are susceptible to thrombus formation, and which provide multiple adjacent regions where platelet-released agents can interact with one another. To distinguish between the role of exogenous and endogenous agents, microchannels were produced that had multiple thrombogenic (fibrinogen) regions separated by non-thrombogenic (BSA-coated) regions. This geometry reveals the effect of agents released from different thrombogenic regions on one another. Adhesion was quantified by percent platelet surface area coverage.
Surface area coverage differed between the upstream and downstream sides of the thrombogenic regions. Positive and negative feedback effects were enhanced by increased platelet production of activator and inhibitor. In contrast, when the NO donor DPTA NONOate was added, with the intent to overwhelm the endogenous feedback, a more uniform spatial distribution of adhesion was obtained.
Though these agonists, activator (ADP) and inhibitor (NO), act on different receptors through different signaling pathways, they all lead to increase or decrease in the intracellular Ca2+ concentration ([Ca2+]) depending on the agonist produced. Ca2+ is a key component and serves as second messenger in all cells regulatory processes. The increase in [Ca2+] leads to several steps of activation. The process leading Ca2+ to increase and decrease and its underlying mechanisms remained largely unknown.To examine Ca2+ response, platelets were loaded with the Fluo-4 Ca2+ ion indicators and fluorescence waveform was monitored. We found that Ca2+ response increased dose dependently with addition of an activator (ADP) and addition of endogenous (L-Arginine) and exogenous (DPTA NONOate) NO donor showed decrease in Ca2+ response in ADP stimulated platelets
Epileptogenic Focus Localization by Novel Analysis of lntracranial EEG in the Frequency Domain
Get PDFThe gold standard for localization of the epileptogenic zone (EZ) continues to be the visual inspection of electrographic changes during seizure onset by experienced EEG readers. Development of an epileptogenic focus localization tool that can accurately delineate the EZ from the analysis of interictal (seizure-free) period is still an open question of great significance for improved diagnosis (e.g., presurgical evaluation) and treatment (e.g., surgical) outcome. We developed an EZ localization algorithm (LA) based on novel analysis of the power in a narrow frequency band of the recorded signals from the brain, that is, using a simple univariate periodogram-type power measure, a straight-forward statistical ranking technique, and a robust dimensional reduction approach; out of the sampled brain regions, the EZ was most frequently maximally active in this band even in seizure-free (interictal) periods. Ten patients with frontal and temporal lobe epilepsy and matching the inclusion criteria (Engel Class I ≥ 12 months post-surgery) were recruited at the University of Alabama Medical Center. In a multi-folded leave-one-out statistical framework, the accuracy of the LA in identifying EZ from interictal intracranial stereo EEG (sEEG) in these patients at the epilepsy monitoring unit (EMU) was 100% (10/10) during the first hours of the sEEG recording and up to their 1st clinical seizure. To further evaluate the LA, data from two new (Engel Class I) patients were analyzed in a double-blinded study; the LA was successful in localizing the focal channels in both of these patients. These findings support the hypothesis that the EZ is
interictally regulated by inhibitory neurons with resonance behavior in a narrow gamma band (~65-85 Hz). We further show that this characteristic band can be determined by a wide range of spectral power estimation univariate or multivariate techniques as well as directed functional connectivity network measures and can therefore easily be missed or rejected due to the use of 60Hz power noise reduction filters as pre-processing tools of the EEG. In conclusion, our LA achieves reliable epileptogenic focus localization across different focal epilepsy types in humans when the analysis is done within a specific “focal frequency band” (FFB) during the early hours of the interictal period at the EMU.
To assist with the elucidation of the mechanisms of seizure generation (ictogenesis) and seizure prediction, we analyzed the dynamics of intracellular calcium concentration ([Cai++]) signals following in vitro stimulation of primary neuronal cultures by nanomolar (subthreshold) concentrations of glutamate (Glu). Employing novel measures of connectivity for the network formed by the firing neurons, we showed that: a) connectivity between neurons increased by addition of Glu, b) the neurons became hyperexcitable following the depletion of astrocytes from the cultures, and c) neuronal networks with astrocytes were less complex and exhibited more predictable outcomes following a wide range of Glu stimuli. These preliminary results, if confirmed in a more extensive set of cultures, suggest that the developed methodology and network measures may be useful for seizure prediction and as biomarkers in the in vivo monitoring and quantitative analysis of the epileptic brain’s activity en route to seizures based on the hypothesis that increase of the levels of glutamate in hyperexcitable neurons in the epileptogenic focus is not balanced by the function of neighboring pathologically impaired astrocytes
Assessing Employees’ Perceptions of the Frequency and Intensity of Workplace Interpersonal Conflict in Lateral and Hierarchical Dyads
Get PDFWorkplace interpersonal conflict has been identified as a potential major source of stress for several occupations. Occupational stress literature concerning this stressor reveals that interpersonal conflict can have adverse outcomes for organizations including absenteeism, turnover, and workers’ compensation claims for psychological injury. Accordingly, researchers have developed measures aimed at capturing perceptions of workplace interpersonal conflict to remediate and prevent it in organizations. Although workplace interpersonal conflict has received considerable attention, there is little research assessing perceptions of conflict from a dyadic perspective in lateral (coworker-coworker) and hierarchical (supervisor-subordinate) relationships between supervisors and non-supervisors. This is important because conflict may be perceived more frequently or intensely between two individuals, compared to a group or organizational team, based on previous research indicating that individuals perceive and experience conflict differently in dyads and groups. The Workplace Interpersonal Conflict Scale was used to compare perceptions of the frequency and intensity of lateral and hierarchical workplace interpersonal conflict among supervisors and non-supervisors in various industries, providing further validity evidence for the instrument. It was expected that supervisors in hierarchical relationships would perceive the most frequent and intense conflict with a subordinate. However, results revealed that participants (i.e., supervisors and non-supervisors) in hierarchical relationships, regardless of whether they were higher or lower in the hierarchy, perceived significantly more frequent conflict than participants in lateral relationships with no significant differences for conflict intensity. An interpretation of the findings is provided in addition to limitations and future directions of the study
Surveillance of teleworkers: a grounded theory approach
Get PDFIn March of 2020, the WHO declared COVID-19 a pandemic. The pandemic mandated teleworking across the world as many organizations tried to social distance. Two years into the pandemic, we have seen quite the increase in telework. Thus, with the benefits being realized, it is reasonable to expect a continuance in telework after the pandemic is over. When forced to work from home, many variables with the work process must be changed, including how managers surveil their employees. My work is an early, exploratory effort to understand how teleworkers are surveilled and how they feel about being surveilled at home. I conducted seven in-depth interviews with individuals who are working from home. The results are two-fold. First, I provided a description of the two types of surveillance – behavior- and outcome-based surveillance. Next, I create a visual model that demonstrates how surveillance can interact with other constructs to affect well-being. The model suggests perceived surveillance will restrict autonomy, which will in turn reduce one’s well-being. Though the relationship between autonomy and well-being is well-established in the literature, my model suggests this relationship can be moderated by perceived justice. When one feels the surveillance is just, the relationship between autonomy and well-being is weakened. Justice perceptions are influenced by the congruence of surveillance expectations (CoSE). CoSE, as I define it, is the fit between how one perceives they are being surveilled and one’s expectations of how they should be surveilled. My findings pose several implications for teleworker managers, outlined in Chapter 5. The qualitative data supporting the induced relationships are disclosed in the appendix
A COMPARATIVE STUDY OF MONO-STABLE AND BI-STABLE MAGNETIC SPRING BASED ENERGY HARVESTERS
Get PDFContinuous advancements in electronics manufacturing have resulted in the widespread use of low-power sensors, necessitating the development of energy harvesters capable of generating electric power from abundant and free energy sources such as ambient vibrations. A rising interest in energy harvesting technology inspires the work discussed herein using magnetic interactions to target nonlinear energy harvesting, which is compatible with ambient vibration energy sources with a broad frequency spectrum and particularly rich in low frequencies. This research aimed to look into a magnetic-levitation-based vibration energy harvester that could be tuned from a mono-stable to a bi-stable configuration. An oscillating magnet is levitated between two stationary top and bottom magnets in a mono-stable arrangement. A bi-stable configuration is achieved by fixing a cluster of peripheral solid magnets around the harvester housing. Magnetic forces in magnetic-levitation-based harvesters have traditionally been represented by polynomial functions integrated into the equation of motion. Analytical models for the interaction of magnets were developed and integrated into the equation of motion in this study. The analytical model of magnetic force delivers more accurate results for the bi-stable configuration than those produced using polynomial functions, according to the findings from this study. The results demonstrated that adjusting the geometric ratios of the peripheral magnets in the bi-stable configuration can produce a variety of load-deflection properties. The bi-stable design exhibits inter-well, chaotic, and intra-well motion at varying accelerations during dynamic operation. The bi-stable architecture benefits from thinner peripheral magnets, especially at lower acceleration values. Lower energy barriers, improved frequency responses, and nearly zero stiffness at equilibrium position are all advantages of thinner peripheral magnets. The harvester moved towards mono-stability when thinner peripheral magnets were utilized, showing that mono-stability is the preferred mode for vibration energy harvesting under harmonic excitation. We also propose an experimental and theoretical platform for developing design platform and performing analysis on mono-stable magnetic springs used in vibration energy harvesting devices. The results reveal a high level of agreement between the model and the experiment. For linear and nonlinear stiffness coefficients, approximate analytical expressions are found. The findings indicate that the linear and nonlinear stiffness coefficients are linked. The stationary ring magnet\u27s outer diameter can be utilized to modify the energy harvesting system\u27s nonlinearity to provide linear, hardening nonlinear, or softening nonlinear responses. Designers can use this work to understand the behavior of magnetic spring-based harvesting systems and assess their performance concerning design factors. Other energy systems that use magnetic springs, such as energy sinks, could benefit from this research
Age-Based Comparison of the Motivations, Self-Efficacy, and Quality of Life in Bariatric Surgery Candidates
Get PDFOverweight and obesity is a worldwide epidemic that is negatively impacting individuals’ health and quality of life. Much research has been conducted regarding the effects of diet and exercise for weight loss, with current research providing evidence in favor of bariatric surgery for severely obese adults and children. The purpose of this project is to understand participants motivating factors, anticipated post-surgery success and anticipated changes in physical, social and mental health. The objectives were to describe participants’ motivations for pursuing bariatric surgery, describe participants level of confidence with postsurgical diet implementation, and compare participants anticipated post-surgery changes in quality of life and compare to current expectations. Using a qualitative research approach, seventeen male and female participants between 25 and 41were individually interviewed. The motivating factors found were health and wellness, comorbidities, family and children, and physical fitness. Participants confidence in their abilities was characterized by practicing postsurgical diet changes, changing presurgical eating habits and work-life balance. Finally, quality of life themes included activities of daily living, enjoying extracurricular activities, improved physical appearance, social eating, attending special events, greater willingness to participate socially and improved anxiety and depression and positive self-perception. Many concepts were found to be overlapping throughout many of the themes which were fear and frustration and energy and stamina. Overall, the small sample size limits the generalizability of the results. The current study provides beneficial information for registered dietitians and related healthcare professionals to better understand their patient population and provide recommendations that best meets the patient’s needs
Servant Leadership in Christian Schools: A Case Study
Get PDFThis study used a biblical leadership theory theoretical lens and a qualitative single-case study design to investigate servant leadership in a Christian school. Data were collected from (a) 33 participants via interviews, (b) eight field observations, and (c) documents, and the data were analyzed using thematic coding via MAXQDA. I found that service was perceived as a fundamental component of a dual-domain paradigm of leadership consisting of a technical and a spiritual domain, and I found that descriptions of service as part of leadership included (a) motivations for service, (b) dispositions associated with serving, (c) acts of service, and (d) effects of being served. I developed a conceptual model to describe these findings and described implications of the model for practitioners in Christian schools, including using the model to inform (a) revisions to mission and vision statements, (b) professional development, and (c) student instruction in leadership. Additionally, I noted that practitioners in Christian schools could use the findings (a) to inform internal studies of spiritual development among staff and students and (b) to understand the complementary relationship between spiritual and technical domains of leadership. I proposed that future research could focus on (a) determining the degree to which Christlike leadership is espoused in Christian schools, (b) developing a comprehensive framework for Christlike leadership, (c) testing my conceptual model in other Christian schools, (d) studying Christian leadership paradigms using a grounded theory approach, and (e) studying the prevalence of and nature of a dual-domain paradigm of leadership in Christian schools
Leadership Practices in Urban High Schools that Decrease Dropout Rates
Get PDFThe purpose of this study was to investigate the practices urban school leaders implement in daily school operations, how they form relationships with their students, and how these practices and relationships affect student initiative to engage in the high school experience and earn a diploma. High school students living in urban communities are often challenged by academic and societal deficits that separate them from their suburban counterparts. Students in these circumstances are more apt to drop out of high school. Leadership practices executed by urban school leaders to connect with their students are instrumental in motivating students to persist toward graduation. This research was conducted as a qualitative phenomenological study of urban high school leaders; it was conducted under the scope of Ryan and Deci’s Motivation Theory and Burns’ Transformational Leadership Theory. Two urban high school leaders from a school district in a southern state participated in the study. Both leaders were interviewed and elaborated upon the strategies, instructional planning, and use of resources in daily school operations. Data from participants’ interviews were collected, transcribed, and analyzed to unveil an emergence of responses, patterns and themes. Coding procedures addressed the research questions and reinforced the theoretical framework for the study. The findings yielded emerging themes reflective of the leaders’ practices including student motivation, relationships, data, guidance and assessments, teacher support and feedback, college and career preparation, parental involvement, and community partnerships. The findings of the study revealed that the urban high school leaders’ practices are effective in decreasing student dropout rates