Browsing by Subject "Structural Equation Modeling"

Now showing 1 - 4 of 4
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    Associations between birth weight/gestational age and social/cognitive functioning across development: Do differences endure?
    (2018-08) Johnson, William
    This study uses data from the Minnesota Longitudinal Study of Risk and Adaptation (N = 267) to test whether birth weight and gestational age prospectively predict cognitive functioning and social competence throughout childhood, adolescence and early adulthood. Using multiple developmentally appropriate indicators of cognitive and social functioning, structural model comparisons test whether Enduring Effects or Revisionist Effects models of development better explain the associations between birth weight/gestational age and cognitive/social functioning. Of the four comparisons (birth weight predicting cognitive functioning, gestational age predicting cognitive functioning, birth weight predicting social competence, gestational age predicting social competence), only birth weight and cognitive functioning were consistently associated across development. The Revisionist Effects model best explained these relations, such that direct associations did not persist over time. Instead, birth weight had direct associations with cognitive functioning in early childhood that were carried forward through stability in cognitive outcomes through early adulthood. These findings are discussed in context of other tests of the Enduring Effects vs. Revisionist Effects models, developmental theory, and intervention application.
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    Microbial Husbandry: Nurturing Microbes to Capture Soil Ecosystem Services
    (2018-09) Ewing, Patrick
    Soil microbes drive many agroecosystem functions that dictate crop productivity, environmental outcomes, and management costs. Chapter 2 introduces microbial husbandry, a framework to manage soil microbes by creating soil conditions that allow critical taxa to thrive. Subsequent chapters apply microbial husbandry to nutrient cycling under maize (Zea mays L.) using a model system, ridge tillage and rye cover cropping (Secale cereale L.). We tested hypotheses with Bayesian structural equation modeling. In Chapter 3, arbuscular mycorrhizal fungi (AMF) insured against early season phosphorus (P) deficiency: AMF contributed to 40% higher maize P uptake in ridge till, at a 7% growth cost. Managers may increase P uptake by reducing physical disturbance to increase AMF abundance, and by increasing bulk density beyond levels in chisel plow. For Chapter 4, we wrote pyroots, a Python computer vision module, to measure roots and fungal hyphae in environmental samples cheaply and reproducibly (Appendix A; www.github.com/pme1123/pyroots). We also reported the first AMF hyphal length density values at 60 cm depth. Hyphal growth was independent of maize root growth, which suggests roots and hyphae can be managed independently. In Chapter 5, filamentous fungi acquired as much mineral nitrogen (N) as maize roots over five weeks after planting. While most root N uptake occurred in rows, fungal uptake occurred in both rows and inter-rows. Managers may encourage fungal N uptake without competing with crop needs by concentrating crop residue in the inter-rows. Overall, microbial husbandry helped us manage competing microbial functions simultaneously: nutrient provisioning in rows, and fertility building in inter-rows. Context-appropriate management tools can create soil conditions that enable microbes to perform these functions.
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    Quality connections: recreation , property ownership, place attachment, and conservation of Minnesota Lakes.
    (2009-05) Schroeder, Susan Arlene
    Recently, people have expressed concerns about how declining outdoor recreation participation and increasing housing development in high-amenity areas may affect conservation attitudes and behaviors as well as environmental quality. Recreation participation and property ownership have been identified as antecedents to place attachment. However, limited research has examined how people develop attachments to specific places and how these attachments relate to management preferences and support for conservation of specific areas. This study used data from two 2004 surveys addressing the management of lakes and aquatic plants in Minnesota. One study was conducted with a sample of Minnesota residents and the other with a sample of lakeshore landowners on "fisheries lakes" in the state. Data were analyzed to examine relationships among recreation participation, lakeshore property ownership, place attachment, and intentions to conserve lakes. Four clusters of recreationists were identified: all-around, appreciative, consumptive, and less-involved. Respondents were also segmented based on their ownership of lakeshore property, and whether property was used as a primary or second home. This study contributed to research on how participation in outdoor recreation relates to environmental attitudes and behavioral intentions. Results suggested that recreation participation relates to attitudes and behavioral intentions for lake protection. Among members of the general public, less-involved participants in lake-based recreation reported significantly lower intentions to take political or philanthropic action to protect lakes. Appreciative recreationists from the general public sample were more likely to take political action, while all-around and consumptive recreationists were somewhat more likely to donate time and money to protect lakes. Among lakeshore property owners, less-involved recreation participants reported lower personal responsibility for protecting their lake generally and a lower rating of personal norms for protecting native aquatic plants. However, all-around recreationists from the lakeshore property owner sample reported significantly higher behavioral intentions to remove native aquatic plants compared to appreciative, consumptive, and less-involved recreationists. The study advanced research on place attachment by: (a) examining visitors' and residents' attachment to Minnesota lakes and (b) how place attachment relates to conservation attitudes and behavioral intentions. Stronger place attachment was associated with property ownership and frequency of recreation participation. The study developed a scale to measure family connections to a lake, which was introduced in this dissertation as normative place attachment. Results supported previous research that has suggested: (a) a positive relationship between outdoor recreation and environmental attitudes, and (b) differences based on the type of recreation participation. Study findings suggested the importance of recreation participation to protection of Minnesota lakes. Participation in lake-based outdoor recreation was related to place attachment, personal responsibility, and behavioral intentions related to lakes. In particular, less-involved recreation participants reported lower levels of attitudinal and normative place attachment to lakes, expressed less personal responsibility for protecting lakes, and had the lowest intentions of taking philanthropic or political action to protect lakes. However, a substantial amount of unexplained variance remained in models of attitudes and behavioral intentions related to the protection of lakes and aquatic plants. Future studies of recreation, property ownership, place attachment, and conservation, could incorporate more comprehensive measures of recreation participation, place attachment, "insidedness" to a place, and environmental attitudes, and behavioral intentions. In addition, future research could examine the influence of place meanings, environmental values, social capital, sense of community, political ideology, educational background, and length of association with a place on environmental attitudes, behavioral intentions, and actual behaviors.
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    Supporting Professional Capacity of Teachers Through Teacher Evaluation
    (2020-12) RYU, JISU
    In many countries, teacher evaluation has been viewed as a policy lever to improve the quality of teaching and student achievement. Recent research suggests that teacher evaluation can also be implemented as a mechanism for professional growth with careful consideration of the organizational context. However, few studies have examined the way in which a teacher evaluation policy may result in the improvement of teaching. Two key features of effective teacher evaluation are first, balancing the two purposes of accountability and professional growth and second, implementing teacher evaluation policies with a shared responsibility among teachers, administrators, and government agencies. This dissertation explored the applicability of this analytical framework within schools by examining associations among teacher evaluation outcomes, their impact on various aspects of teaching, and a school climate of shared responsibility. The framework was used to examine teacher evaluation in four countries: the U.S., Finland, South Korea, and Japan. This study delved into the following questions: (1) How are national teacher evaluation policies implemented at the local level in four countries? (2) How are teacher evaluation policies and school climate associated with teachers’ perceived professional capacity in four countries? (3) How are teacher evaluations associated with teachers’ professional capacities when evaluation is accompanied by support of teacher professional growth? These research questions were investigated using the Organization for Economic Cooperation and Development (OECD) 2013 surveys of principals and teachers. The findings showed that, despite differences in national policies to reform teacher evaluation, teachers in all four countries still viewed teacher evaluation largely as an administrative requirement. However, further analysis revealed that teachers were more likely to perceive that teacher evaluation was positively associated with their professional capacities when it was coupled with school-level actions to support their professional growth and a school-level climate of shared responsibility. Because teacher evaluation policies exist in most countries, the potential impact of improved implementation at local and national levels could be substantial.