79717 research outputs found
Sort by
Novel Extensions and New Applications for Nonparametric Self-Exciting Point Processes
Get PDFIn this dissertation I will demonstrate a novel application of self-exciting point process models to mass shooting data. I will also introduce two adaptations to the traditional nonparametric Hawkes process modeling framework. One such modification allows for the estimation of the additional productivity introduced by an event that is not a part of the point process, as demonstrated by the impact of presidential rallies on COVID-19 cases. The second modification introduces the smooth estimation of the triggering functions, with an application to the Hector Mine earthquake data
Understanding the Application and Benefits of Learning-based Methods in Nuclear Science and Engineering
Get PDFKnown as the fourth industrial revolution, digitization is an ongoing trend in all fields, in which various industries are integrating information technologies to support and improve their businesses. Nuclear technology industries have also increased their interest in data-driven methods by leveraging the potential of pattern recognition to identify anomalies and to take actions more rapidly, in areas such as health and monitoring, radiation detection, and optimization. By acknowledging the practicality and popularity of these methods, it is imperative to understand the benefits and barriers of implementing such methodologies to create better research plans and identify project risks and opportunities. This dissertation discusses different technologies and their integration and challenges within the nuclear industry. It is recognized that concepts of complexity and emergent behavior, as well as the importance of such properties as a distinctive aspect of nuclear and radiological engineering problems in which holistic approaches are crucial to innovation. Overall, the development and application of learning-based methods can be promising in the nuclear industry and many related tasks as long as expert knowledge is considered in the desired application to ensure a robust application of such methods. Cross-discipline studies and the creation of benchmarks are highly suggested for future practices
Early Childhood Teachers’ Compassion Fatigue: The Roles of Adverse Childhood Experiences and Supportive Relationships with Leaders and Co-Teachers
Get PDFCompassion fatigue is a common struggle that helping professionals face; however, it is not yet well understood in early childhood teachers. Compassion fatigue results from caring for individuals who have had traumatic experiences, which can cause physical and emotional exhaustion, leading to a diminished ability to empathize with individuals in one’s care. It is important to identify factors that may affect teachers’ risk for compassion fatigue because it not only impacts the individual through the development of physical and emotional symptoms, but also their interactions with children. Adverse childhood experiences (ACEs) may increase an individual’s vulnerability to compassion fatigue (Nelson-Gardell et al., 2003) through long-lasting effects on an individual’s emotion regulation (Poole et al., 2018). Research is also needed to identify how workplace resources (i.e., leader and co-teacher support) may reduce the risk of early childhood teachers developing compassion fatigue. This study examined how early childhood teachers’ ACEs and perception of leader and co-teacher support may affect early childhood teachers’ compassion fatigue. Participants were 49 early childhood teachers from home-based, center-based, and Head Start early learning programs. In this small sample, ACEs, leader support, and co-teacher support were not significantly associated with compassion fatigue. More research is needed to identify personal and work environment characteristics related to compassion fatigue that could be targeted in future interventions to improve the well-being and performance of early childhood teachers
Assessing the impact of multicomponent diffusion in direct numerical simulations of premixed, high-Karlovitz, turbulent flames: toluene data
No full textThis data contains results from direct numerical simulations of premixed, three-dimensional, turbulent toluene/air flames, using the multicomponent and mixture-averaged diffusion models. In particular, this dataset contains information about diffusion flux angles and magnitudes. We performed the simulations using the finite-difference code NGA; simulation details are described completely in the associated article
Making Sense of Counseling and Counselor Training in the Chinese Context: Two IPA Studies on U.S.-Trained Chinese Counselors’ Experiences Practicing in China
Get PDFMental health disorders are the leading cause of disability worldwide. The strong need for mental health services has prompted intensive global efforts to develop, evaluate, and deliver effective mental health treatment, especially for low- and middle-income countries. The counseling profession in the United States has responded to this global need by promoting counseling internationally, collaborating with mental health professionals worldwide, and training counselors to serve diverse populations both domestically and internationally. Despite the strong interest in and need for the U.S. counseling profession to promote counseling worldwide, scholars have been warning the danger of unexamined transplanting of the U.S. counseling model in the international context due to the context-specific, culture-specific, and language-specific nature of counseling.
U.S. trained Chinese counselors practicing in China possess the knowledge, languages, and cultural background to understand both the U.S. counseling culture and their home culture. Their experiences providing counseling based on the U.S. training model in the Chinese context shed light on the validity and feasibility of U.S. counseling and counselor training models in an international context. No previous studies have investigated their experiences practicing counseling in the Chinese context. Using Interpretative Phenomenological Analysis (IPA) qualitative method, this dissertation sought to understand their lived experiences adapting counseling to the Chinese context and their sense making of the U.S. counseling training in relation to providing counseling in China.
IPA allows the researcher to explore nuanced human experiences and meaning making processes, paying special attention to the context in which the participants function. The researcher recruited eight participants who met the criteria of 1) self-identified as Chinese; 2) lived in China through high school; 3) graduated from a Master’s level counseling program in the United States; and 4) worked with Chinese clients in China after graduating from the counseling program. The researcher utilized IPA data analysis as described by Smith and Nizza (2022) and adopted strategies such as peer debriefing, member checks, reflexivity, and thick description to increase trustworthiness.
The first study (n=8) explored the lived experiences of U.S. trained Chinese counselors adapting counseling to the Chinese context. The study’s findings indicate that such counselors experience: multisystemic dissonance leads to a quest to adapt U.S. counseling training to practice in China, actively reaching for internal and external resources to adapt, taking deliberate actions as adaptation strategies, and experiencing professional and personal growth connected to adaptation.
The second study (n=8) explored how U.S. trained Chinese counselors make sense of their U.S. counseling training in relation to providing counseling in the Chinese context. The study’s findings indicate that such counselors perceive: U.S. counseling training as a cognitive and emotional experience, lived experience in the United States as essential to learning, the Chinese workplace as a testing ground for training, and a relearning and reorganization process of past training and experiences.
The findings have wide implications for counselor educators and counseling programs, international counseling students and graduates, as well as future research on applying U.S. counseling and counselor training in a global context
Expanding Diagnostic Assays for Pseudoloma neurophilia & Description of the Progression of Infection in Adult Zebrafish Populations
Get PDFPseudoloma neurophilia is the most common pathogen reported in zebrafish (Danio rerio) research facilities and is an important threat to the zebrafish model. This microsporidian parasite can cause clinical disease, but more importantly is a causative agent of non-protocol induced variation in research. Studies utilizing infected zebrafish, could potentially confound their research findings, as this parasite can cause clinical disease and significant changes to the behavior, immune system, fecundity, and overall physiology of the fish. Therefore, there is growing investment in diagnostics for zebrafish research facilities, to ensure embryos and fish are specific-pathogen free.
Assays for prevalent zebrafish pathogens are continually expanding, however for P. neurophilia, the only diagnostic methods available are through lethal sampling, often requiring euthanasia of a large portion of a given population for accurate estimates of prevalence. Thus, I optimized nonlethal assays to detect Pseudoloma neurophilia in tank water adapting a previously developed qPCR assay that was adapted to the digital PCR (dPCR) platform. I coupled the assay with the use of sonication to improve spore disruption in water samples, resulting in an eDNA assay with a detection limit in water lower than all previously reported assays (77.5 spores/ L). Prevalence data and occupancy modeling supported our observations, revealing that samples collected in static conditions were more informative for diagnostics than samples from flow-through conditions, with prevalence of positive samples at 80% or higher compared to 47%, respectively.
Utilizing the array of diagnostics assays available for the detection of P. neurophilia (histology, whole body analysis by qPCR, and eDNA analysis of tank water), I then compare the application of these assays and tracked the progression of infection over a 10-month period. I found that detection of the parasite occurs as early as 4 days post exposure (dpe) by whole-body qPCR, while detection by histological analysis did not occur until 92 dpe. Moreover, I highlight that there are positive associations with the days post exposure and the sensitivity of the assays, as PCR is much more sensitive than histology, however the probability of detection for both assays, increases over time.
I then investigated modifying our eDNA assay, by employing the use of different equipment, namely an upgrade to the sonication equipment and a different PCR machine, to detect the parasite more reliably in the water. Thus, I also describe a modified protocol for extraction and quantification of parasite DNA from the environment for nonlethal diagnosis of P. neurophilia in adult zebrafish populations, which has a detection limit of 4.5 spores/L. Using this modified eDNA assay, I evaluated previously collected water samples from the 10-mon longitudinal analysis, targeting times near initial infection. The parasite was detectable in the water after initial exposure until week 4 post exposure (pe), when the parasite was undetectable until 7 weeks pe. After that time, the parasite was sporadically detected in the water for the 10-month study, highlighting the important dynamics of infection and subsequently, our ability to detect the parasite in the environment. I showed that the parasite is frequently in the environment in low concentrations (presumably as spores), until infections become prominent in fish, and are likely only shed in high concentrations during spawning and chronic states of infection. Thus, I elucidated the mystery of early infection and progression of infection within a population, enhancing our knowledge about the dynamics of infection.
Using water samples from the Zebrafish International Resource Center, Eugene Oregon, I also validated the clinical relevance on the assay, revealing an association, again, with the age of the fish and the amount of parasite in the water. The integration of this assay will significantly compliment surveillance and control efforts in zebrafish research facilities. Coupling all diagnostics assays will aid in control efforts to eradicate the pathogen from zebrafish research facilities
Math Anxiety and Financial Literacy among Latino Secondary Students in the United States
Get PDFThe Latino K-12 student population in the United States continues to increase. Estimates are that by 2025, one in every three students in the country will be of Hispanic/Latino origin. The challenges to the educational system from such growth are unprecedented. At no other time in U.S. history has there been such an increase in student population from a specific cultural group. This dissertation was composed of two arms, each of which examined an area of Latino students’ academic development critical to post high school success. The data for the dissertation was drawn from the Program for International Student Assessment (PISA) database.
Arm A was a cross-sectional study exploring math anxiety. The U.S. sample included 6,111 students, 15 years of age. The specific research questions were: (a) What is the level of math anxiety in Latino youth?; (b) What is the level of math anxiety associated with different levels of math proficiency in Latino youth?; (c) When looking at Latino youth, does the level of math anxiety differ between boys and girls?; and (d) Among the (non-Latino) youth of the United States, does the level of math anxiety differ by race/ethnicity?. Results indicated that Latino youth reported a mean math anxiety level similar to the overall American average. The results also demonstrated that students in the lowest two math-proficiency levels did not differ from each other in terms of math anxiety, nor did the students in the two highest proficiency levels. Another finding was that as the proficiency levels increased, the level of math anxiety decreased. Third, female Latino youth reported higher math anxiety than their male counter parts. Finally, race/ethnicity did not differentiate levels of math anxiety.
Arm B was a cross-sectional study exploring financial literacy. In the United States, 5,712 students participated in the PISA 2015 assessment; of these, 1,486 participated in the financial literacy section of the test. The research questions were the same as Arm A, except financial literacy and not math anxiety was the focus. Analysis yielded the following results. First, the level of financial literacy in Latino youth indicated that financial literacy score is normally distributed among the sample. Second, the level of financial literacy by math proficiency level in Latino youth demonstrated that students’ math proficiency levels are associated with their financial proficiency level, and as math proficiency level increases, so does financial literacy levels. In addition, it was determined that students’ math proficiency levels are associated with their financial literacy and that as math proficiency levels increase, so does the financial literacy levels. Third, there was a difference between female and male Latino youth in financial literacy. Finally, in determining if the level of financial literacy differed by race/ethnicity, the results suggested that race/ethnicity may partly explain variability in financial literacy. Hispanic students scored significantly higher than African American and lower than White, Asian and multicultural students.
The above-mentioned findings have implications for school counselors and for educators since their interactions with students tend to significantly influence students’ career planning decisions and high school course enrollment. Furthermore, counselors also guide students through the process of financial aid and through the process of managing their finances after they graduate from high school. Understanding and supporting the needs and characteristics of Latino students are the keys for their academic and career success
Interfacial Relaxation and Two-Fluid Flow in Porous Media: A Fast X-Ray Microtomography Study
Get PDFThe flow of multiple immiscible fluids within a porous medium controls many natural and engineered systems in the environment including: geologic CO2 sequestration, enhanced oil recovery from underground reservoirs, and contaminant remediation of groundwater. The need to understand how fluids are transported and distributed in these processes is important for designing accurate models that can improve process efficiency. The research comprising this dissertation developed and utilized a fast X-ray microtomography technique that allows for three-dimensional, near real-time, investigations of multiphase flow. Constitutive relationships based on multiphase state variables (saturation, capillary pressure, interfacial area, fluid topology) are tested for accurate predictions of quasi- and non-equilibrium two-fluid flow experiments in an effort to better understand the role of fluid relaxation on these relationships and state variables. The effect of bubble generation and transport, relevant to multiphase processes such as air stripping, on these relationships is also studied. Collectively, results show the need for constitutive relationships which include all four measured state variables to uniquely predict two-fluid flow independent of flow condition or bubble generation. An empirical relationship is also developed to predict interfacial area, an important mass transfer parameter, depending on the degree of relaxation within the system. Overall, the presented findings may help design more efficient engineering practices and transport models
Columbia River Gillnetter ; Vol. 40, No. 1 (Winter 2009)
No full textThe Columbia River Gillnetter is the pilot of the Lower Columbia River commercial fishing industry, keeping fishermen and the public in touch with today's important issues
Columbia River Gillnetter (Autumn 1989)
No full textThe Gillnetter is published to keep commercial fishermen and the public informed of the facts and happenings in the Columbia River fishing industry, and all people connected with it