321 research outputs found
Tooze\u27s The Life and Letters of Emily Chubbuck Judson (Fanny Forester): Volume 7, 1826-1854 The Collected Poetry and Fiction (Book Review)
Lynd\u27s Leaving innocence: A Gran and Bass Olson mystery (Book Review)
Lynd, D. (2016). Leaving innocence: A Gran and Bass Olson mystery. Bloomington, IN: WestBow Press. 259 pp. $19.95. ISBN 978149089447
Adapting to salinity: The effects of salinity on population structure and offspring survival in Lucania parva
Adaptation to salinity is an important driving force in the evolution in teleost fishes. Some speciose groups such as minnows and characids are found predominantly in fresh water, while other groups such as tunas and wrasses are found predominantly in marine habitats. Euryhaline groups, such as killifish, contain freshwater species, marine species, and species that can occur in fresh, brackish, and marine conditions. These groups are powerful systems for studying adaptation to salinity as they allow for the comparison of close relatives who differ in salinity tolerance. In chapter 1, I review the biology of Lucania killifish. Lucania contains three species, one of which is a freshwater species (L. goodei) and another of which is euryhaline (L. parva). A third species (L. interioris) is endemic to a small region in Mexico and is not considered in this thesis. Previous studies on L. goodei and L. parva suggest that salinity has dramatic effects on life-history, ecology, physiology, and genetic differentiation at the between-species level. Upon salinity transfer, the two species differ in gene expression in critical osmoregulatory genes. An examination of FST outliers suggests that the two species differ in many genes related to osmoregulation, but that they also possess high levels of differentiation between genes involved in reproduction and spermatogenesis. Within L. parva, preliminary work indicated that freshwater-saltwater population pairs also possessed elevated levels of differentiation in loci related to osmoregulation.
In chapter 2, I used RAD-Seq data from 10 populations across Florida to examine the levels of population structure between freshwater and saltwater populations and the effects of distance on population-wide FST. Here, I found good evidence that differences in salinity increase FST beyond what would be expected from the effects of distance alone.
In chapter 3, I describe a laboratory experiment that tests for both local adaptation and for maternal effects as a function of salinity. Early development is a critical life stage. From their earliest moments in life, embryos cannot regulate their ion and water levels because the physiological traits needed for active osmoregulation have not yet developed. Instead, embryos rely on the properties of the egg and maternal provisioning to maintain proper ion and water levels. Hence, this stage of development is ripe for maternal effects (either genetic or environmental) that influence offspring survival as a function of salinity. In chapter 3, I describe the results of an experiment where I performed within population crosses for a freshwater and a saltwater population from the Wakulla River drainage. In the experiment, I considered the effects of population of origin (fresh versus salt) and the effects of spawning salinity (the salinity in which spawning pairs were housed) and rearing salinity (the salinity in which eggs and fry were kept). Hence, the experiment allows me to examine the effects of population of origin and parental salinity environment on subsequent survival as a function of salinity. Here, I found little evidence for local adaptation as a function of salinity. Maternal effects were present, but the nature of the pattern did not suggest that they were adaptive. I suggest that other life-history stages such as over-winter survival, perhaps in the presence of intraspecific competition, should be assessed.
My thesis indicates that there is evidence for heightened genetic divergence between freshwater and saltwater populations, yet we do not know precisely how these effects emerge. Salinity may affect multiple life-history stages (i.e., growth, survival to adulthood, over-winter survival) beyond the ones examined in this thesis. Salinity may also affect multiple aspects of ecology, including community composition (i.e., potential competitors, predators, and prey items), which may create parallel selection due to ecological demands
Large Scale Specimen Design and Creep Analysis for Nuclear Containment Concrete Walls
Nuclear containment facilities in the US are quickly approaching the end of their design lives. However, due to the need for energy and the staggering cost of constructing new facilities, the industry is hoping to push the service lives of existing structures upwards of 80 years. Therefore, it is necessary to identify the risks associated with long term use of such facilities. Since these structures are typically post-tensioned concrete containment vessels, one of the main concerns is the phenomenon known as concrete creep.
This study focuses on observing the effects of concrete creep by constructing three large scale reinforced concrete wall sections to model variable contributing factors to the creep phenomenon. Concrete strains and temperatures through the thicknesses of the specimens, as well as the strain in select post-tensioning bars used to apply specimen stresses, are measured.
From six months of measured data since post-tensioning, there were noticeable changes in the post-tensioning bar strains and concrete strains, which is most likely the result of changes in ambient temperature in the winter months, and possibly creep. To confirm the field data values, a simple, static finite element model was developed to simulate concrete strain changes as a result of post-tensioning. The model confirmed the preliminary field data was closely related to the numerical estimations, with deviations stemming from the lack of complexity of the model. The model can be easily modified in the future to include concrete creep and other important physical occurrences that the specimens undergo in practical applications.
This research, in conjunction with materials tests being conducted in the lab by other students, will provide the framework for a powerful predictive creep model to be developed to analyze the expected lifespans of such existing structures
The Mind-Body Split: Toward a Queer Temporality in Sarah Orne Jewett\u27s Deephaven
The ending of Sarah Orne Jewett’s novel Deephaven has long puzzled critics. After enjoying a summer’s respite from the strictures of nineteenth-century womanhood, Kate Lancaster and Helen Denis return to genteel, middle-class life in Boston. For critics who choose to read Kate and Helen’s relationship as lesbian, the return signifies not only the loss of freedom from gender restraints, but also the loss of the girls’ relationship. The return to Boston, whose social scene revolves around the search for suitable husbands, implies a return to the heterosexual sequence of courtship, marriage, and childbirth. For Judith Fetterley (“Reading Deephaven as a Lesbian Text,” 1993) the return constitutes submission to the heterosexual configuration of time as linear and progressive. But if the final chapter implies that the return to Boston is inevitable, it also implies that the girls claim agency in dividing their minds from their bodies. This article comprises two parts: in the first part, I demonstrate how the final chapter dramatizes a mind-body split. In the second part, I use this mind-body split as a framework for discussing how Deephaven theorizes queer ways of thinking about time, offering its heroines the means of transcending the body’s restriction to linear, progressive time
Spatiotemporal Discordance in Five Common Measures of Rurality for US Counties and Applications for Health Disparities Research in Older Adults
Introduction Rural populations face numerous barriers to health, including poorer health care infrastructure, access to care, and other sociodemographic factors largely associated with rurality. Multiple measures of rurality used in the biomedical and public health literature can help assess rural–urban health disparities and may impact the observed associations between rurality and health. Furthermore, understanding what makes a place truly “rural” versus “urban” may vary from region to region in the US. Purpose The objectives of this study are to compare and contrast five common measures of rurality and determine how well-correlated these measures are at the national, regional, and divisional level, as well as to assess patterns in the correlations between the prevalence of obesity in the population aged 60+ and each of the five measures of rurality at the regional and divisional level. Methods Five measures of rurality were abstracted from the US Census and US Department of Agriculture (USDA) to characterize US counties. Obesity data in the population aged 60+ were abstracted from the Behavioral Risk Factor Surveillance System (BRFSS). Spearman’s rank correlations were used to quantify the associations among the five rurality measurements at the national, regional, and divisional level, as defined by the US Census Bureau. Geographic information systems were used to visually illustrate temporal, spatial, and regional variability. Results Overall, Spearman’s rank correlations among the five measures ranged from 0.521 (percent urban–urban influence code) to 0.917 (rural–urban continuum code–urban influence code). Notable discrepancies existed in these associations by Census region and by division. The associations between measures of rurality and obesity in the 60+ population varied by rurality measure used and by region. Conclusion This study is among the first to systematically assess the spatial, temporal, and regional differences and similarities among five commonly used measures of rurality in the US. There are important, quantifiable distinctions in defining what it means to be a rural county depending on both the geographic region and the measurement used. These findings highlight the importance of developing and selecting an appropriate rurality metric in health research
Role of Student Teaching in Balancing Student Teachers' Educator Role Profile
Over the past several years, agricultural education has faced a shortage of qualified teachers to fill the ever-growing vacancies throughout the United States. This lack of qualified teachers has put the pressure on teacher preparation programs to take on the challenge of preparing student teachers to thrive in the experiential world of agricultural education. Previous studies have focused on teacher preparation but few studies have examined the effectiveness of teacher preparation programs, specifically the effectiveness of the student teaching experience, in preparing student teachers to be experiential educators. This non-experimental survey design study aimed determine the impact of the student teaching experience on student teachers' experiential educator skill development. Thirty-six student teachers from four representative universities in Oklahoma and Texas completed a modified summated needs assessment version of Kolb, Kolb, Passarelli and Sharma's (2014) Educator Role Profile three times: pre-, mid- and post- student teaching. The findings of this study revealed that student teachers were highly involved in high school agricultural education and the FFA but most did not grow up on a farm. It also found student teaching enhances all four roles in varying amounts and ways, narrows the gaps between importance and competence and between competence and authentic assessment, and grows perceived competence in all educator roles. Student teachers do not find being an expert important nor do they think they are good at it, are predominately coaches, and grew the most between the mid- and post-administrations in both importance and competence. Authentic Assessment revealed growth only in the facilitator role. Needs assessments in each administration indicated that student teachers have different skill needs at distinctive stages of their student teaching experience. Recommendations include providing opportunities to connect with the agricultural industry and agricultural content, reevaluating agricultural education course requirements, using the ERP as a part of the student teacher feedback process, educating student teachers are the importance of utilizing the stages of ELT and the ERP roles in their classrooms and providing cooperating teachers with training on the educator roles to improve evaluation.Agricultural Educatio
Large Scale Specimen Design and Creep Analysis for Nuclear Containment Concrete Walls
Nuclear containment facilities in the US are quickly approaching the end of their design lives. However, due to the need for energy and the staggering cost of constructing new facilities, the industry is hoping to push the service lives of existing structures upwards of 80 years. Therefore, it is necessary to identify the risks associated with long term use of such facilities. Since these structures are typically post-tensioned concrete containment vessels, one of the main concerns is the phenomenon known as concrete creep.
This study focuses on observing the effects of concrete creep by constructing three large scale reinforced concrete wall sections to model variable contributing factors to the creep phenomenon. Concrete strains and temperatures through the thicknesses of the specimens, as well as the strain in select post-tensioning bars used to apply specimen stresses, are measured.
From six months of measured data since post-tensioning, there were noticeable changes in the post-tensioning bar strains and concrete strains, which is most likely the result of changes in ambient temperature in the winter months, and possibly creep. To confirm the field data values, a simple, static finite element model was developed to simulate concrete strain changes as a result of post-tensioning. The model confirmed the preliminary field data was closely related to the numerical estimations, with deviations stemming from the lack of complexity of the model. The model can be easily modified in the future to include concrete creep and other important physical occurrences that the specimens undergo in practical applications.
This research, in conjunction with materials tests being conducted in the lab by other students, will provide the framework for a powerful predictive creep model to be developed to analyze the expected lifespans of such existing structures
Psychosocial factors of caregiver burden in child caregivers: results from the new national study of caregiving
Background Over 50 million informal caregivers in the United States provide care to an aging adult, saving the economy hundreds of billions of dollars annually from costly hospitalization or institutionalization. Despite the benefits associated with caregiving, caregiver stress can lead to negative physical and mental health consequences, or “caregiver burden”. Given these potential negative consequences of caregiver burden, it is important not only to understand the multidimensional components of burden but to also understand the experience from the perspective of the caregiver themselves. Therefore, the objectives of our study are to use exploratory factor analysis to obtain a set of latent factors among a subset of caregiver burden questions identified in previous studies and assess their reliability. Methods All data was obtained from the 2011 National Study of Caregiving (NSOC). Exploratory factor analysis (EFA) was performed to identify a set of latent factors assessing four domains of caregiver burden in “child caregivers”: those informal caregivers who provide care to a parent or stepparent. Sensitivity analysis was also conducted by repeating the EFA on demographic subsets of caregivers. Results After multiple factor analyses, four consistent caregiver burden factors emerged from the 23 questions analyzed: Negative emotional, positive emotional, social, and financial. Reliability of each factor varied, and was strongest for the positive emotional domain for caregiver burden. These domains were generally consistent across demographic subsets of informal caregivers. Conclusion These results provide researchers a more comprehensive understanding of caregiver burden to target interventions to protect caregiver health and maintain this vital component of the US health care system
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