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- Title
- FACTORS RELATED TO STRESS IN NURSING STUDENTS.
- Creator
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Shultz, Marie, Covelli, Maureen, University of Central Florida
- Abstract / Description
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The purpose of this review of literature was to explore and critically analyze relevant literature regarding stress factors and the consequences of stress in nursing students. Findings from this review of literature aimed to provide a better understanding of stress factors and the physical and psychological impact of stress on nursing students. Information was collected from the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and MEDLINE- EBSCOhost databases to explore...
Show moreThe purpose of this review of literature was to explore and critically analyze relevant literature regarding stress factors and the consequences of stress in nursing students. Findings from this review of literature aimed to provide a better understanding of stress factors and the physical and psychological impact of stress on nursing students. Information was collected from the Cumulative Index to Nursing and Allied Health Literature, PsycINFO, and MEDLINE- EBSCOhost databases to explore what research has been conducted and to assess the current knowledge base. Analysis of the literature indicated that nursing students reported experiencing increased levels of stress during the academic year. Nursing students reported higher levels of stress in conjunction with elevated external stressors, including increased responsibilities and course requirements. Analysis of the findings suggested that factors related to stress in nursing students arose from clinical sources, academic sources, and personal sources. Further analysis indicated that experiencing elevated levels of stress had a negative impact on the student. Increased levels of stress, combined with poor coping mechanisms, may lead to poor academic performance and burn-out among nursing students. Future research may evaluate means to reduce stress levels and mitigate stress in nursing students through targeting specific causative factors. Findings from this review of literature aim to influence student management of stress.
Show less - Date Issued
- 2011
- Identifier
- CFH0003825, ucf:44778
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0003825
- Title
- Molecular Mechanisms involved in inflammatory angiogenesis induced by monocyte chemotactic protein induced protein-1 (MCPIP1).
- Creator
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Roy, Arpita, Kolattukudy, Pappachan, Ebert, Steven, Parthasarathy, Sampath, Self, William, University of Central Florida
- Abstract / Description
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Major diseases such as cardiovascular diseases, diabetes, obesity and tumor growth are known to involve inflammatory angiogenesis. MCP-induced protein 1 (MCPIP1) encoded by ZC3H12A gene, was reported to promote angiogenesis and is addressed in my dissertation as MCPIP. The mechanism/s involved in the angiogenic differentiation induced by MCPIP was however unknown. The aim of this study was to bridge this gap in our knowledge and delineate the molecular mechanisms and sequential processes...
Show moreMajor diseases such as cardiovascular diseases, diabetes, obesity and tumor growth are known to involve inflammatory angiogenesis. MCP-induced protein 1 (MCPIP1) encoded by ZC3H12A gene, was reported to promote angiogenesis and is addressed in my dissertation as MCPIP. The mechanism/s involved in the angiogenic differentiation induced by MCPIP was however unknown. The aim of this study was to bridge this gap in our knowledge and delineate the molecular mechanisms and sequential processes involved in angiogenesis mediated via MCPIP. To determine if angiogenesis induced by inflammatory cytokines, TNF-?, IL-1? and IL-8 is mediated via induction of MCPIP, knockdown of MCPIP by its specific siRNA, in human umbilical vein endothelial cells was performed. Oxidative stress, ER stress and autophagy are known to be involved in mediating inflammation. We hypothesized that MCPIP-induced angiogenic differentiation is mediated via induction of oxidative stress, ER stress and autophagy. Chemical inhibitors and specific gene knockdown approach were used to inhibit each process postulated. Oxidative stress was inhibited by apocynin or cerium oxide nanoparticles or knockdown of NADPH oxidase subunit, phox47. Endoplasmic reticulum (ER) stress was blocked by tauroursodeoxycholate or knockdown of ER stress signaling protein IRE-1 and autophagy was inhibited by the use of 3?methyl adenine, or LY 294002 or by specific knockdown of beclin1. Matrigel assay was used as an in vitro tool to assay angiogenic differentiation. Inhibition of each step inhibited the subsequent steps postulated. The results reveal that angiogenesis induced by inflammatory agents is mediated via sequential induction of MCPIP that causes oxidative and nitrosative stress resulting in ER stress leading to autophagy required for angiogenesis. MCPIP has deubiquitinase and anti-dicer RNase activities. If and how the dual enzymatic activities of MCPIP mediate angiogenesis was unknown. Our results showed that hypoxia-induced angiogenesis is mediated via MCPIP. MCPIP deubiquitinated ubiquitinated hypoxia-inducible factor (HIF-1?) and the stabilized HIF-1? entered the nucleus to promote the transcription of its target genes, cyclooxygenase-2 and vascular endothelial growth factor causing the activation of p38 MAP kinase involved in angiogenesis. MCPIP expression promoted angiogenesis by inhibition of thrombospondin-1 synthesis via induction of silent information regulator (SIRT)-1 and/or via suppression of VEG-inhibitor levels caused by inhibition of NF-?B activation. MCPIP inhibited the production of the anti-angiogenic microRNAs (miR)-20b and miR-34a that repress the translation of HIF-1? and SIRT-1, respectively. Cells expressing the RNase-dead mutant of MCPIP, D141N, that had lost the ability to induce angiogenesis had deubiquitinase activity but did not inhibit the production of miR-20b and miR-34a. Mimetics of miR-20b and miR-34a inhibited MCPIP-induced angiogenesis. These results show for the first time that both deubiquitinase and anti-dicer RNase activities of MCPIP are involved in inflammatory angiogenesis. Results from our study delineate key processes that could be potential targets for therapeutic intervention against inflammatory angiogenesis.
Show less - Date Issued
- 2012
- Identifier
- CFE0004793, ucf:49760
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004793
- Title
- EXPLORING STRESS MANAGEMENT AND COPING MECHANISMS IN PARENTS OF INFANTS IN THE NEONATAL INTENSIVE CARE UNIT (NICU).
- Creator
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Day, Samantha E, Decker, Jonathan, University of Central Florida
- Abstract / Description
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The purpose of this study was to conduct a literature review that examined parental coping mechanisms and stress relief techniques for parents of infants admitted to the neonatal intensive care unit (NICU). A search was conducted using multiples databases using key terms such as stress AND coping, parent* OR caregiver, ped* OR child*, support* or aid, NICU OR neonatal intensive care unit, and nurs*. The results were limited to scholarly, peer reviewed journals in the English language....
Show moreThe purpose of this study was to conduct a literature review that examined parental coping mechanisms and stress relief techniques for parents of infants admitted to the neonatal intensive care unit (NICU). A search was conducted using multiples databases using key terms such as stress AND coping, parent* OR caregiver, ped* OR child*, support* or aid, NICU OR neonatal intensive care unit, and nurs*. The results were limited to scholarly, peer reviewed journals in the English language. Exclusion criteria included not relating to parents or caregivers and mechanisms of coping with stress or if they pertain to palliative or end-of-life care. Each article meeting the inclusion criteria were critiqued and analyzed for information pertaining to the topic of this review. The thirteen articles yielded from the search revolved around the common themes of Visitation/Participation, Communication, and Comfort Measures. The literature revealed an overall positive association in reducing the amount of stress experienced when an intervention was provided. Implications for further research involve directly comparing the efficacy of interventions to determine which could be most useful in practice.
Show less - Date Issued
- 2019
- Identifier
- CFH2000467, ucf:45863
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH2000467
- Title
- DEPRESSION: AN INVESTIGATION OF THE RISK FACTORS ASSOCIATED WITH HIGH DEPRESSIVE SYMPTOMS AMONG THE LATINO IMMIGRANT POPULATION.
- Creator
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Altamirano, Elizabeth, Negy, Charles, University of Central Florida
- Abstract / Description
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Depression seems to affect a large portion of Americans living the U.S. Specifically, it has been found to affect the Latino population more so than other ethnicities. When considering Latino immigrants, it is important to take into consideration the additional challenges (e.g. adaptation, acculturation) that may lead to the development of depression. In the current study, the aim is to find a relationship between depression and other psychological constructs (e.g. dominant group and...
Show moreDepression seems to affect a large portion of Americans living the U.S. Specifically, it has been found to affect the Latino population more so than other ethnicities. When considering Latino immigrants, it is important to take into consideration the additional challenges (e.g. adaptation, acculturation) that may lead to the development of depression. In the current study, the aim is to find a relationship between depression and other psychological constructs (e.g. dominant group and intragroup marginalization, acculturative stress) in order to determine high risk factors for depressive symptoms among Latino immigrants in the Florida community. 128 Latino immigrants (44 males, 81 females, 3 indicated no specific gender) residing in the Central Florida Community completed scales assessing Marginalization by non-Latinos, Marginalization by Latinos, Symptoms of Depression, and Social Support. Marginalization by Whites and by Latinos/as was not associated significantly with symptoms of depression (rs = .16 and -.02, ps > .05, respectively). In contrast, acculturative stress correlated significantly with symptoms of depression (r = .33, p < .01). It was also predicted that social support would mitigate the association between acculturative stress and symptoms of depression. To test this, I first established that social support correlated significantly with symptoms of depression (r = -.39, p < .001). Next, a partial correlation analysis was conducted to determine the relation between acculturative stress and symptoms of depression while partialing social support. The resulting correlation (r = .30, p < .01) suggested that social support did not account for the observed association between acculturative stress and symptoms of depression. From a clinical perspective, this research is beneficial in knowing what may contribute to depressive symptoms among a growing population, which could then create additional components to consider in treatments.
Show less - Date Issued
- 2015
- Identifier
- CFH0004789, ucf:45330
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004789
- Title
- ASPECTS OF GOALS AND REWARDS SYSTEMS AS ANTECEDENTS OF ABUSIVE SUPERVISION: THE MEDIATING EFFECT OF HINDRANCE STRESS.
- Creator
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Bardes, Mary, Folger, Robert, University of Central Florida
- Abstract / Description
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In this study, I draw on research on goal setting, stress, and aggression to examine contextual antecedents of abusive supervision. I suggest that a characteristic of the supervisors' goals (viz., goal difficulty) can contribute to abusive supervisory behaviors through the effect it has on the supervisors' level of hindrance stress. I also propose that this mediating process is moderated by two characteristics of the supervisors' rewards (viz., goal-contingent reward and reward...
Show moreIn this study, I draw on research on goal setting, stress, and aggression to examine contextual antecedents of abusive supervision. I suggest that a characteristic of the supervisors' goals (viz., goal difficulty) can contribute to abusive supervisory behaviors through the effect it has on the supervisors' level of hindrance stress. I also propose that this mediating process is moderated by two characteristics of the supervisors' rewards (viz., goal-contingent reward and reward interdependence). Thus, I suggest a moderated mediation model predicting supervisors' hindrance stress acts as a mediator of the relationship between supervisors' difficult goals and abusive supervision. Moreover, I also posit that the mediation is stronger when the supervisors' rewards are contingent on goal attainment and their subordinates' performance. With a sample of 257 supervisor-subordinate dyads, I find that supervisors' hindrance stress partially mediates the relationship between supervisors' difficult goals and abusive supervision. However, the results revealed that this mediating effect is not moderated by the characteristics of the supervisors' rewards that were examined. The theoretical and practical implications of this study are identified and future research is discussed.
Show less - Date Issued
- 2009
- Identifier
- CFE0002569, ucf:48263
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002569
- Title
- The Examination of a Mobile Application for the Reduction of Posttraumatic Stress Related Symptoms in Emergency Dispatchers.
- Creator
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Willis, Emy, Beidel, Deborah, Bowers, Clint, Neer, Sandra, University of Central Florida
- Abstract / Description
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Emergency dispatchers report that their jobs are stressful, yet there are few controlled investigations examining their specific psychological complaints. Additionally, research examining the use of interventions directed at alleviating their work-related stress is limited. This study aims to examine the efficacy and feasibility of a mobile application (PTSD Coach) on various indicators of psychosocial well-being among emergency telecommunicator dispatchers. A sample of 117 emergency...
Show moreEmergency dispatchers report that their jobs are stressful, yet there are few controlled investigations examining their specific psychological complaints. Additionally, research examining the use of interventions directed at alleviating their work-related stress is limited. This study aims to examine the efficacy and feasibility of a mobile application (PTSD Coach) on various indicators of psychosocial well-being among emergency telecommunicator dispatchers. A sample of 117 emergency dispatchers completed self-report psychological mood assessments at baseline, weekly for five weeks during PTSD Coach use and post-treatment. Participant report of psychological symptoms showed statistically significant decreases in mood severity over the period of one month.
Show less - Date Issued
- 2019
- Identifier
- CFE0007556, ucf:52595
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007556
- Title
- Seriously Though... Is Positive Workplace Humor a Help or a Hindrance?: The Impact of Coworker-Employee Humor Interactions on Employee Well-Being and Effectiveness.
- Creator
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Sierra, Mary Jane, Jentsch, Kimberly, Salas, Eduardo, Dipboye, Robert, Piccolo, Ronald, University of Central Florida
- Abstract / Description
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The prevalence and importance of humor in the workplace has been well-documented over the past several decades, with research consistently revealing its significant impact on employee well-being and effectiveness. During this same time period, organizations worldwide have begun embracing team-based work designs as a means for achieving success. As a result, the degree to which employees are engaging in both frequent and intensive interactions with their coworkers is rapidly increasing....
Show moreThe prevalence and importance of humor in the workplace has been well-documented over the past several decades, with research consistently revealing its significant impact on employee well-being and effectiveness. During this same time period, organizations worldwide have begun embracing team-based work designs as a means for achieving success. As a result, the degree to which employees are engaging in both frequent and intensive interactions with their coworkers is rapidly increasing. Despite these trends, little research has been dedicated to investigating the ways in which employees' well-being and effectiveness are influenced by the humor of their coworkers or the ways in which employees' own humor interacts with that of their coworkers to determine these outcomes. The current study answered the need for such research by investigating the impact of coworker-employee humor interactions on employee strain and performance using a sample of undergraduate-level students engaged in a high-fidelity work simulation. In the current study, coworker humor was experimentally manipulated by pairing each participant with a study confederate who was trained to act as either a non-humorous coworker or a humorous coworker throughout the duration of the work simulation. Results of a pilot study provided empirical evidence supporting the validity of this manipulation; showing that participants' paired with a humorous confederate coworker rated their coworker significantly higher on positive humor, but no different on negative humor, than participants' paired with a non-humorous confederate coworker. Based on theory and prior findings drawn from multiple streams of science, it was expected that positive coworker humor would have a significant impact on employees' strain and performance, but that the nature of its influence on these outcomes would be contingent upon employees' own dispositional humor. Specifically, it was hypothesized that employees paired with humorous coworkers would experience a lesser degree of perceived, affective, cognitive, and physical strain than employees paired with non-humorous coworkers if their own sense of humor was high but a greater degree of perceived, affective, cognitive, and physical strain than employees paired with non-humorous coworkers if their own sense of humor was low. In addition, it was expected that employees paired with humorous coworkers would demonstrate a higher level of interpersonal and task performance than employees paired with non-humorous coworkers if their own sense of humor was high but a lower level of interpersonal and task performance than employees paired with non-humorous coworkers if their own sense of humor was low. Finally, it was hypothesized that employees' strain would partially mediate the effects of coworker-employee humor interactions on employee performance.In support of these hypotheses, analyses revealed that several indicators of employees' perceived, affective, cognitive, and physical strain were in fact each significantly influenced by interactions between employees' own humor and that of their coworkers. Specifically, high sense of humor employees who worked with a humorous coworker experienced a lesser degree of perceived, affective, cognitive, and physical strain than did those who worked with a non-humorous coworker. This was evidenced by their lower self-reported perceived strain (an indicator of perceived strain), higher state-level positive affect and lower state-level negative affect (indicators of affective strain), higher anagram task performance and lower perceived task difficulty (indicators of cognitive strain), as well as their lower systolic blood pressure and lower state-level somatic anxiety (indicators of physical strain). In contrast, low sense of humor employees who worked with a humorous coworker experienced a greater degree of perceived, affective, cognitive, and physical strain than did those who worked with a non-humorous coworker. This was evidenced by their higher self-reported perceived strain, lower state-level positive affect and higher state-level negative affect, lower anagram task performance and higher perceived task difficulty, as well as their higher systolic blood pressure and higher state-level somatic anxiety. Consistent with expectations, results revealed that the degree to which employees experienced job strain typically varied based on the degree to which there was a match between employee sense of humor and coworker positive humor levels. Similar levels of coworker and employee humor generally resulted in relatively low levels of employee strain whereas dissimilar levels of coworker and employee humor most often resulted in relatively high levels of employee strain. Contrary to expectations, however, coworkers' positive humor and employees' sense of humor did not interact to predict employees' interpersonal or task performance. Instead, positive coworker humor had a significant positive main effect on both forms of employee performance. Although these findings are consistent with the study hypotheses in that positive coworker humor was expected to enhance high sense of humor employees' performance, they run counter to the expectation that positive coworker humor would hinder low sense of humor employees' performance. Because the interaction between coworker humor and employee humor was not a significant predictor of either type of employee performance, analyses were not conducted to test for mediated moderation.Findings from the current study offer a number of contributions to organizational science and, in addition, hold several implications for practice. Specifically, these results have relevance for and greatly expand the workplace humor, individual differences, PE fit, occupational health, and workgroup/team composition literatures. In addition, results contribute to the literature by elucidating the need for future research dedicated to exploring the direct and interactive effects of coworker characteristics, including humor, on employee well-being and effectiveness. Finally, results of this study serve to inform researchers and practitioners in matters related to several critical human resource functions, including matters in personnel selection, placement, and training, as well as in workgroup/team composition.
Show less - Date Issued
- 2013
- Identifier
- CFE0005058, ucf:49954
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005058
- Title
- TOWARD A MODEL OF TEAM DECISION MAKING UNDER STRESS.
- Creator
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Marshall, Alyssa, Salas, Eduardo, University of Central Florida
- Abstract / Description
-
Today's organizations are increasingly relying on teams, rather than individuals, to complete tasks in the workplace. For some teams, these tasks require them to make high stakes decisions under stressful conditions. In military, medical, and emergency response fields, for example, workers are regularly asked to make decisions under high time pressure, uncertainty, and risk. The purpose of this study is to summarize previous team decision-making perspectives and create a model for team...
Show moreToday's organizations are increasingly relying on teams, rather than individuals, to complete tasks in the workplace. For some teams, these tasks require them to make high stakes decisions under stressful conditions. In military, medical, and emergency response fields, for example, workers are regularly asked to make decisions under high time pressure, uncertainty, and risk. The purpose of this study is to summarize previous team decision-making perspectives and create a model for team decision-making under stress. A literature review was conducted to examine the current state of team decision-making research. Several existing models of the team decision-making process were identified, representing multiple decision-making perspectives. Using this information, four primary characteristics of the team decision making process were identified. Team decision making appears to be multi-level, multi-phasic, dynamic, and cyclical process. An additional search examined the effects of stress on performance. Using this information and the characteristics outlined from the team decision making literature, a model was designed to describe the effects of stress on team decision making. This model offers several propositions regarding the effects of stress on specific cognitive and team processes and their relationship team decision making. This study provides the theoretical basis for an empirical investigation of the relationship between stress and team decision making. This line of research has the potential to lead to practical solutions that may improve outcomes for workers in high stress occupations.
Show less - Date Issued
- 2014
- Identifier
- CFH0004629, ucf:45299
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004629
- Title
- FINITE ELEMENT ANALYSIS OF A TEST SPECIMEN FOR STRENGTH OF A CO-POLYMER AT A BONE-IMPLANT INTERFACE.
- Creator
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Chhabra, Nitin, Nicholson, David W., University of Central Florida
- Abstract / Description
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The aim of this work is to evaluate the mechanical strength of a co-polymer of 2-hydroxyethylmethacrylate (HEMA) and methylmethacrylate (MMA), so that it can be applied as an interfacial layer between bone cement and steel implants to improve their performance and life. Finite element (FE) analysis techniques are used to assess the behavior of the interface layer under static and dynamic loading conditions. The material property of the co-polymer is a function of its composition and water...
Show moreThe aim of this work is to evaluate the mechanical strength of a co-polymer of 2-hydroxyethylmethacrylate (HEMA) and methylmethacrylate (MMA), so that it can be applied as an interfacial layer between bone cement and steel implants to improve their performance and life. Finite element (FE) analysis techniques are used to assess the behavior of the interface layer under static and dynamic loading conditions. The material property of the co-polymer is a function of its composition and water saturation. The factors affecting the strength of the bone-implant interface are many. Implant interfacial fracture can lead to decreased stability. Fatigue life is a very important process in failure. The results obtained from static and dynamic analyses show that increasing the percentage of HEMA improves the strength of the interface by reducing the stiffness of the implant, absorbing more energy and by reducing the interfacial stress peaks and making the stress distribution more nearly uniform.
Show less - Date Issued
- 2004
- Identifier
- CFE0000076, ucf:46082
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000076
- Title
- THE RELATION BETWEEN OPTIMISM AND JOB PERFORMANCE: AN APPLIED SETTING.
- Creator
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Davis, Mary, Wooten, William, University of Central Florida
- Abstract / Description
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Research on cognitive ability measures consistently concludes that they are predictive of employee performance. While accounting for only about 9% of the variance in performance, however, cognitive ability measures are not sufficient. Alternative measures, such as measures of personality constructs, must be included to fully predict employee performance. The research on personality measures suggests that they are marginally predictive of employee performance. Research also suggests that...
Show moreResearch on cognitive ability measures consistently concludes that they are predictive of employee performance. While accounting for only about 9% of the variance in performance, however, cognitive ability measures are not sufficient. Alternative measures, such as measures of personality constructs, must be included to fully predict employee performance. The research on personality measures suggests that they are marginally predictive of employee performance. Research also suggests that predicative accuracy of personality measures can be enhanced when the measure is specific to the situation (i.e., stress measure are more predictive of performance in high stress situations compared to moderate or low stress situations). The current study compares a specific measure of a personality construct, the Seligman Attributional Style Questionnaire (a measure of optimism), with a broad, general measure of personality, the Gordon Personal Profile-Inventory, comparing jobs specifically requiring higher levels of optimism versus jobs that do not require high levels of optimism. The results suggest that the use of the SASQ under situationally specific conditions does not result in greater predictive accuracy that the more generic GPPI. In addition, neither measure resulted in significant correlations with employee performance. The study generally confirmed the literature on the limited utility of personality measures in predicting performance. It also raised questions about how situational specificity is operationized.
Show less - Date Issued
- 2006
- Identifier
- CFE0001262, ucf:46930
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001262
- Title
- INVESTIGATING THE EFFECTS OF TACTILE STRESS ON A MILITARY TOUNIQUET APPLICATION TASK.
- Creator
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Nayeem, Razia, Hancock, Peter, University of Central Florida
- Abstract / Description
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In combat, soldiers encounter stress from multiple sources including loss of sleep, extremely high levels of physical and psychological discomfort, extended periods of increased vigilance, and intense danger. Therefore, it is imperative to train such personnel on how to cope with these stressors. One way to do this is to include stressors in different forms of training to acclimate soldiers to the subsequent stress of combat. Due to their advantages, tactile trainers are being investigated...
Show moreIn combat, soldiers encounter stress from multiple sources including loss of sleep, extremely high levels of physical and psychological discomfort, extended periods of increased vigilance, and intense danger. Therefore, it is imperative to train such personnel on how to cope with these stressors. One way to do this is to include stressors in different forms of training to acclimate soldiers to the subsequent stress of combat. Due to their advantages, tactile trainers are being investigated increasingly for the use of training Army medics in this context. The present work examines how vibrating tactile sensors, or tactors, can be used as surrogate sources of stress on an operator performing a simulated medical task. This work also examines how this "optimal" configuration interacts with other types of stress, such as noise and time pressure. The outcome findings support the hypotheses that configurations placed on sensitive body areas are more stressful than those placed on more benign body locations in terms of worse task performance on a tourniquet application task. In terms of application times, the same trends persist in terms of proper application, subjective stress and subjective workload, as well as a secondary monitoring task, in terms of response times, accuracy, and time estimation. Additionally, findings supported hypotheses that the stress responses experienced order tactile stress alone is compounded when other types of stress are employed, both on the primary and secondary tasks. These results have implications for training, such that if stressors are employed in training, performance decrements might be lessened during actual task performance; they can be generalized to not only combat medics, but other military specialties and civilian jobs that incur vibration, auditory stress, and time pressure while engaged in performance.
Show less - Date Issued
- 2008
- Identifier
- CFE0002028, ucf:47612
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0002028
- Title
- THE RELATIONSHIP BETWEEN SELF-REPORTED CHRONIC STRESS AND DIVIDED ATTENTION PERFORMANCE.
- Creator
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Petrac, Diane, Bedwell, Jeffrey, University of Central Florida
- Abstract / Description
-
While previous research has extensively examined the effect of acute stress on cognitive performance, relatively little research has explored the relationship between chronic stress and cognitive performance. The current study aimed to control for current state anxiety to better isolate more chronic stress, when examining the relationship with performance on divided attention tasks. Fifty-four university undergraduates, who self-reported a wide range of perceived chronic stress (10-item...
Show moreWhile previous research has extensively examined the effect of acute stress on cognitive performance, relatively little research has explored the relationship between chronic stress and cognitive performance. The current study aimed to control for current state anxiety to better isolate more chronic stress, when examining the relationship with performance on divided attention tasks. Fifty-four university undergraduates, who self-reported a wide range of perceived chronic stress (10-item Perceived Stress Scale), completed the Trail-Making Test and a dual (auditory and visual) Continuous Performance Test (CPT). Hierarchical regressions were performed to explore cognitive predictors of chronic perceived stress. After covarying for state anxiety (state portion of State-Trait Anxiety Inventory), the most statistically significant predictor (via stepwise entry) was the auditory omission error change score (dual minus single condition), which showed a medium effect size (r = .36). Results have practical safety implications, as the implementation of an efficient and inexpensive measure of self-reported stress may predict future job-related errors in high-stress professions that require divided attention.
Show less - Date Issued
- 2006
- Identifier
- CFE0001509, ucf:47125
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001509
- Title
- THE EFFECTS OF STRESS ON DISTANCE PERCEPTION.
- Creator
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Rosen, Monica, Neider, Mark, University of Central Florida
- Abstract / Description
-
Although there has been a great deal of research on binocular distance perception (Foley, 1980; Gogel, 1977), a number of questions remain unexplored. One such question involves how our ability to perceive distances is influenced by fitness and stress (internal and external). Previous research has shown that kinesthetic stress (via backpack weight) influences a person's ability to accurately guess distances (Proffitt, Bhalla, Gossweiler, & Midgett, 2003). This research did not only attempt to...
Show moreAlthough there has been a great deal of research on binocular distance perception (Foley, 1980; Gogel, 1977), a number of questions remain unexplored. One such question involves how our ability to perceive distances is influenced by fitness and stress (internal and external). Previous research has shown that kinesthetic stress (via backpack weight) influences a person's ability to accurately guess distances (Proffitt, Bhalla, Gossweiler, & Midgett, 2003). This research did not only attempt to replicate previous work, but also extend it by exploring potential interactions between fitness level and mental stress on distance perception, a combination that is often encountered by soldiers, firefighters, and rescue workers. Mental stress was measured using the State Anxiety Inventory test (Spielberger, Reheiser, & Sydeman, 1995) and cardiovascular fitness was measured using MET scores (Jurca et al., 2005). Physical stress was manipulated by asking participants to estimate distances and then walk blindly to the target while carrying a backpack weighing 20% of their weight. We were unable to replicate Proffitt. We did however find a positive correlation between cardiovascular fitness and error in the second block of the blind walking task for the heavy backpack condition, r(22) = -.45, p = 0.03.
Show less - Date Issued
- 2013
- Identifier
- CFH0004526, ucf:45185
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFH0004526
- Title
- The Effects of a 10-week Judo Program on Cortisol and Stress in Children with Autism Spectrum Disorder.
- Creator
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Renziehausen, Justine, Garcia, Jeanette, Fukuda, David, Stout, Jeffrey, University of Central Florida
- Abstract / Description
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Children diagnosed with Autism Spectrum Disorder (ASD) often have increased levels of stress, leading to dysregulated production of cortisol. Elevated levels of cortisol have numerous known adverse health consequences, and therefore, interventions should be established to help attenuate cortisol production. As judo combines physical activity and mindfulness practice, it may aid in stress reduction and decreased levels of cortisol. Purpose: To examine the effects of a 10-week judo program on...
Show moreChildren diagnosed with Autism Spectrum Disorder (ASD) often have increased levels of stress, leading to dysregulated production of cortisol. Elevated levels of cortisol have numerous known adverse health consequences, and therefore, interventions should be established to help attenuate cortisol production. As judo combines physical activity and mindfulness practice, it may aid in stress reduction and decreased levels of cortisol. Purpose: To examine the effects of a 10-week judo program on stress reactions and salivary cortisol levels in youth with ASD. Methods: 20 children with ASD participated in the 10-week judo program. Changes in acute (before and after one judo session) and chronic salivary cortisol levels were assessed at baseline and post intervention. Parents of participants were asked to complete the Stress Survey Schedule (SSS) to determine severity of stress reactions. The SSS consists of 10 subscales: changes, anticipation, unpleasant, positives, food related, rituals, social/environmental, sensory/personal, fears, and life stressors. Sleep quality was assessed via Actigraph GT9X accelerometers over a 7-day period at baseline and post-intervention. Paired samples t-tests were used to determine differences SSS pre/post-intervention. Repeated measures ANOVA was conducted to determine differences and in cortisol levels before and after one judo session and pre and post-intervention. Spearman correlations were used to determine correlations between sleep quality and subscales of the SSS. Results: Although not statistically significant, a trend was noted indicating a decrease in cortisol levels following one judo session (p=.057). Nonsignificant reductions in the subscales (")changes (p=.14)(") and (")unpleasant (p=.12)(") of the SSS were also observed. Conclusion: Acute changes in cortisol levels may be seen following one session of judo. Subscales of parent-reported questionnaire may also show improvements following 10 weeks of participation in a judo program.
Show less - Date Issued
- 2019
- Identifier
- CFE0007522, ucf:52622
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0007522
- Title
- The Role of Mitochondrial Omi/HtrA2 Protease in Protein Quality Control and Mitophagy.
- Creator
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Ambivero, Camilla, Zervos, Antonis, Teter, Kenneth, Siddiqi, Shadab, Self, William, University of Central Florida
- Abstract / Description
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Omi/HtrA2 is a nuclear encoded mitochondrial serine protease with dual and opposite functions that depend entirely on its subcellular localization. During apoptosis it is released to the cytoplasm where it participates in cell death. While confined in the mitochondria it has a pro-survival function that may involve the regulation of protein quality control (PQC) and mitochondrial homeostasis. We used the yeast two-hybrid system to dissect Omi/HtrA2's pathway by identifying novel interactors...
Show moreOmi/HtrA2 is a nuclear encoded mitochondrial serine protease with dual and opposite functions that depend entirely on its subcellular localization. During apoptosis it is released to the cytoplasm where it participates in cell death. While confined in the mitochondria it has a pro-survival function that may involve the regulation of protein quality control (PQC) and mitochondrial homeostasis. We used the yeast two-hybrid system to dissect Omi/HtrA2's pathway by identifying novel interactors and substrates. Our studies revealed a novel function of Omi/HtrA2 in the regulation of a Lys-63 deubiquitinating (DUB) complex. In addition, we found the mechanism by which Omi/HtrA2 protease participates in mitophagy by directly regulating the protein level of Mulan E3 ubiquitin ligase, especially during mitochondrial stress.Abro1 is a scaffold protein of the DUB complex known as BRISC (BRCC36 isopeptidase complex). In addition, Abro1 is involved in a cytoprotective pathway and is regulated by Omi/HtrA2. Three specific interactors of Abro1 protein were identified, ATF4, ATF5 and JunD, all members of the activating protein 1 (AP-1) family. We focused our studies on ATF4 since, like Abro1, it is ubiquitously expressed and is important in cell cycle regulation and survival. Abro1's interaction with ATF4 was specific and occurred only when cells were stressed. The significance of this interaction was the translocation of Abro1 from the cytoplasm to the cell nucleus. These results establish a new cytoprotective function of cytoplasmic Omi/HtrA2 as a regulator of the BRISC DUB complex.Furthermore, we have recently identified the mitochondrial Mulan E3 ubiquitin ligase as a substrate of Omi/HtrA2 protease. Mulan, along with MARCH5/MITOL and RNF185, are the only three mitochondrial E3 ubiquitin ligases identified thus far. The function of Mulan has been linked to cell growth, cell death, and autophagy/mitophagy. To investigate Mulan's function and its control by Omi/HtrA2, E2 conjugating enzymes that form a complex with Mulan E3 ligase were identified. Four specific interacting E2s were isolated, namely Ube2E2, Ube2E3, Ube2G2, and Ube2L3. To identify substrates for each unique Mulan-E2 complex, fusion baits were used in a modified yeast two-hybrid screen. Our results suggest that Mulan participates in various pathways, depending on the nature of its E2 conjugating enzyme partner. One of the interactors isolated against the Mulan-Ube2E3 bait was the GABARAP (GABAA receptor-associated protein), a member of the Atg8 family. We characterized this interaction both in vitro and in vivo and its potential role in mitophagy. Our studies defined a new pathway by which Mulan participates in mitophagy by recruiting GABARAP to the mitochondria.
Show less - Date Issued
- 2013
- Identifier
- CFE0004805, ucf:49752
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0004805
- Title
- Piezospectroscopic Calibration of Alumina-Nanocomposites for the Development of Stress-Sensing Structures.
- Creator
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Fugon-Dessources, Daniela, Raghavan, Seetha, Gou, Jihua, Orlovskaya, Nina, University of Central Florida
- Abstract / Description
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Alpha-alumina is known to exhibit photo-luminescent (PL) properties, mainly characteristic R-lines that shift according to applied stress. In addition to showing excellent PL properties, polymers with embedded alumina nanoparticles have been shown to improve the overall composite mechanical properties. While the use of the PL properties to develop stress-sensing materials using an alumina-epoxy material has been success- fully shown in compression, the properties have not been developed for...
Show moreAlpha-alumina is known to exhibit photo-luminescent (PL) properties, mainly characteristic R-lines that shift according to applied stress. In addition to showing excellent PL properties, polymers with embedded alumina nanoparticles have been shown to improve the overall composite mechanical properties. While the use of the PL properties to develop stress-sensing materials using an alumina-epoxy material has been success- fully shown in compression, the properties have not been developed for tension. In this study, the PL response of variable volume fraction alumina-epoxy composites will be determined under tensile conditions. It is expected that increasing the volume fraction of alumina nanoparticles will increase the sensitivity of the particles PL emission shift to applied stress. Three tensile alumina-epoxy specimens of 21.0%, 31.2%, and 34.5% volume fractions were manufactured and tested under tensile static loads. The results of this experiment will determine the piezospectroscopic (PS) coefficient and calibration of bulk alumina nanocomposites in tension. A linear region was identified in the PS response of the nanocomposite to the applied tensile load. The PS coefficient of this linear region increased as the volume fraction of the nanocomposite increased. To demonstrate the application of structural composites with stress sensing capabilities, alumina nanoparticles were integrated in the manufacturing of a carbon fiber composite specimen. The results of the stress-sensing composite mechanical experiment showed that alumina nanoparticles were able to detect changes in stress. The results for both the bulk nanocomposite calibrations and the application of stress-sensing alumina nanoparticles in a carbon-fiber composite will advance the development of this novel stress-sensing method.
Show less - Date Issued
- 2014
- Identifier
- CFE0005168, ucf:50661
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0005168
- Title
- A DYNAMIC MODEL OF THE HUMAN/COOLINGSYSTEM/CLOTHING/ENVIRONMENT SYSTEM.
- Creator
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pu, zhengxiang, Kapat, Jayanta, University of Central Florida
- Abstract / Description
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The human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where...
Show moreThe human body compensates well for moderate climatic heat stress, but artificial environments often block or overwhelm physiological defense mechanism. Personal protective equipment (PPE) is one of sources of heat stress. It protects individual from chemical, physical, or biological hazards, but the high thermal insulation and low vapor permeability of PPE may also lead to substantial heat stress. Personal cooling is widely used to alleviate heat stress, especially for those situations where ambient environmental cooling is not economically viable or feasible. It is important to predict the physiological responses of a person wearing PPE with personal cooling to make sure that the individual is free of heat stress, as well as any additional discomfort that may occur. Air temperature, radiant temperature, humidity and air movement are the four basic environmental parameters that affect human response to thermal environments. Combined with the personal parameters of metabolic heat generated by human activity and clothing worn by a person, they provide the six fundamental factors which define human thermal environments. If personal cooling system is available, the fluid flow speed, cooling tube distribution density and fluid inlet temperature have significant effects on the human thermal comfort. It is impractical to evaluate the problem experimentally due to too many factors involved. A thermal model was developed to improve human body thermal comfort prediction. The system researched includes human body, personal cooling system, clothing and environment. An existing model of thermoregulation is taken as a starting point. Changes and additions are made to provide better prediction. Personal cooling model was developed and it includes liquid cooling model, air cooling model and ice cooling model. Thermal resistance networks for the cooling system are built up; additionally a combined model of heat and mass transfer from cooling garment through clothing to environment is developed and incorporated into the personal cooling model and thermoregulatory model. The control volume method is employed to carry out the numerical calculation. An example simulation is presented for extra-vehicular activities on Mars. The simulation results agree well with available experimental data, though a small discrepancy between simulation results and experimental data is observed during the beginning of the cooling process. Compared with a water cooling lumped model, the thermal model provides a much better prediction. For water cooling, parametric study shows that the cooling water inlet temperature and liner thermal resistance have great effects on the maximum exposure time; PPE resistance and cooling water flow rate do not have much impact on the maximum exposure time. For air cooling, cooling air flow rate, inlet temperature, relative humidity and liner resistance have great effects on the maximum exposure time.
Show less - Date Issued
- 2005
- Identifier
- CFE0000416, ucf:46407
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000416
- Title
- STRESS, FATIGUE AND WORKLOAD: DETERMINING THE COMBINED AFFECT ON HUMAN PERFORMANCE.
- Creator
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Mock-McLaughlin, Jessica, Crumpton-Young, Lesia, University of Central Florida
- Abstract / Description
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This research generated a model that will help to predict, prevent, control and mitigate the occurrence of task related factors that negatively influence stress, fatigue, and workload; thus enhancing human performance. Past research efforts involving stress, fatigue and workload identified factors that influence a change in performance (Lan, Ji and Looney, 2003, and Hancock & Warm, 1989). Also, while some mathematical models have been developed within each respective area, however, there is...
Show moreThis research generated a model that will help to predict, prevent, control and mitigate the occurrence of task related factors that negatively influence stress, fatigue, and workload; thus enhancing human performance. Past research efforts involving stress, fatigue and workload identified factors that influence a change in performance (Lan, Ji and Looney, 2003, and Hancock & Warm, 1989). Also, while some mathematical models have been developed within each respective area, however, there is no evidence of an integrated model describing the combined affect of stress, fatigue and workload. To respond to this research gap, a quantitative model representing the state of stress, fatigue and workload experienced under task conditions was developed. This model was derived using fuzzy set theory with data inputs from both objective and subjective measures such as heart rate, NASA TLX, blood pressure and a variety of additional factors. The resultant mathematical model included both subjective and objective measures that can be collected in an occupational environment. Control rooms at the flight centers for large space craft were utilized to validate the quantitative model developed in this research. Data was gathered during launch simulation exercises. Fuzzy Set Theory was applied to develop the mathematical model to describe the changes in stress, fatigue and workload. FST provides a means to model many real-world environments.
Show less - Date Issued
- 2007
- Identifier
- CFE0001639, ucf:47231
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001639
- Title
- EFFECT OF HORIZONTAL PILES ON THE SOIL BEARING CAPACITY FOR CIRCULAR FOOTING ABOVE CAVITY.
- Creator
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Arosemena, Rafael, Kuo, Shiou-San, University of Central Florida
- Abstract / Description
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The design of foundation in normal soil conditions is governed by bearing capacity, minimum depth of foundation and settlement. However, foundation design in karst regions needs to consider an additional criterion associated to the possibility of subsurface subsidence and ravelling sinkholes. Under this environment, alternative techniques are needed to improve the subsurface soil. In this study general background information is given to understand the geological characteristics of Central...
Show moreThe design of foundation in normal soil conditions is governed by bearing capacity, minimum depth of foundation and settlement. However, foundation design in karst regions needs to consider an additional criterion associated to the possibility of subsurface subsidence and ravelling sinkholes. Under this environment, alternative techniques are needed to improve the subsurface soil. In this study general background information is given to understand the geological characteristics of Central Florida and why this area is considered to be a karst region and susceptible to sinkholes formation. Traditional foundation design techniques on karst regions are addressed in this paper. Finally, the use of a network of three subsurface horizontal piles is proposed and the effect on stress increase and soil bearing capacity for footing due to the horizontal piles is investigated. Finite element computer software is used to analyze the stress distribution under different conditions and the results are discussed. The objective of this study is to determine whether or not horizontal piles under a circular footing at the sinkhole site is a viable solution to reduce the stress increase in the soil induced by the footing load. The horizontal piles located at a certain depth below the center of the footing intercepts the cone of pressure due to the footing load. Also, it is the purpose of this research to determine the effect on the soil bearing capacity for footing due to the proposed horizontal piles at the sinkhole prone area. In 1983 Baus, R.L and Wang, M.C published a research paper on soil bearing capacity for strip footing above voids. In their research, a chart for soil bearing capacity for strip footing located above a void was presented. However, in this paper we present a chart for circular footing size as a function void location and a design chart for circular footing size with a network of three underground piles. The result indicates that with the horizontal piles placed above the cavity, the stress increase caused by the footing load substantially decreases as compared to the situation of no horizontal piles, thus increases the soil bearing capacity for the normal design of footing size. The approach of using the horizontal piles placed in between the footing and the subsurface cavity is a new concept that has not been experienced previously. The results are strictly based on the analytical model of finite element program. Before full implementation for the construction practice, further research and experimental work should be conducted.
Show less - Date Issued
- 2007
- Identifier
- CFE0001643, ucf:47224
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0001643
- Title
- SELENOTRISULFIDE DERIVATIVE OF ALPHA-LIPOIC ACID: EVALUATION IN A CELL CULTURE MODEL FOR POTENTIAL USE AS A TOPICAL ANTIOXIDANT.
- Creator
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Alonis, Melenie, Self, William, University of Central Florida
- Abstract / Description
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Selenium is a required micronutrient in mammalian cells. It is incorporated in the form of selenocysteine into selenoenzymes such as glutathione peroxidase and thioredoxin reductase, and is absolutely required for activity. Thioredoxin reductase is necessary for reduction of oxidized thioredoxin and therefore plays a major role in maintaining the redox status of the cell. Glutathione peroxidase is responsible for reducing peroxides into their corresponding alcohols and water. Together, these...
Show moreSelenium is a required micronutrient in mammalian cells. It is incorporated in the form of selenocysteine into selenoenzymes such as glutathione peroxidase and thioredoxin reductase, and is absolutely required for activity. Thioredoxin reductase is necessary for reduction of oxidized thioredoxin and therefore plays a major role in maintaining the redox status of the cell. Glutathione peroxidase is responsible for reducing peroxides into their corresponding alcohols and water. Together, these selenoenzymes constitute a significant part of the cell's arsenal to defend itself against oxidative stress. Exogenous sources of oxidative stress, such as UV radiation, are capable of generating reactive oxygen species (ROS). Elevated levels of ROS can lead to covalent modifications of lipids, nucleic acids, and proteins within a cell. This damage has been implicated in the development of cancer and degenerative diseases. As the skin is the first level of defense for UV radiation, skin cancer is an obvious concern. Previous studies have demonstrated a protective effect against UV-induced cytotoxicity when selenium compounds were administered to skin cells in cell culture models. Topical selenium application to mice has also been shown to reduce UV damage to skin. Although a variety of chemical forms of selenium are available in nutritional supplements, the efficiency by which they are used for selenoprotein synthesis varies greatly. It is debated within the selenium research community which form is best for use as a supplement. In this study, we have focused on a selenotrisulfide derivative of alpha-lipoic acid (LASe). We have examined its utilization for selenoprotein synthesis through radiolabeling studies (75Se) in a human keratinocyte cell line (HaCaT). We have determined that is incorporated into selenoproteins with nearly the same efficiency as selenite and L-selenocysteine. We have also determined that LASe is far more efficient as a supplement in cell culture than selenate or L-selenomethionine, two forms of selenium commonly used as supplements. LASe was also found to protect HaCaT keratinocytes from UV- induced cytotoxicity. Cells pretreated with LASe and exposed to 500J/m2 and 750J/m2 of broadband (UVA/UVB) UV radiation showed greater survival than untreated controls in a dose –dependent manner. Cells pre-treated either with lipoic acid or selenium in the form of selenite alone also observed protection. Nonetheless, these finding are significant given that LASe was previously shown to penetrate the skin better than other forms of selenium. These results indicate that LASe has the potential for use as a topical antioxidant upon further testing in animal studies.
Show less - Date Issued
- 2005
- Identifier
- CFE0000663, ucf:46531
- Format
- Document (PDF)
- PURL
- http://purl.flvc.org/ucf/fd/CFE0000663
