Kansas State University Salina Aerospace and Technology Campus
K-State Research ExchangeNot a member yet
43997 research outputs found
Sort by
Gene loss, co-option and the evolution of developmental complexity in the volvocine algae
No full textDoctor of PhilosophyGenetics Interdepartmental ProgramBradley J OlsonThe evolution of multicellularity is a Major Evolutionary Transition that has occurred in each domain of life and has evolved independently numerous times in diverse eukaryotic lineages. Multicellularity is associated with changes to developmental complexity; this is thought to be a consequence of multicellular species collectively organizing into higher level individuals. Hence, extant descendants of early multicellular lifeforms exhibit a wealth of morphological and developmental innovations. Despite the recurring nature and biological importance of multicellular evolution, determining the molecular mechanisms underlying it presents several challenges. Most notably, in most multicellular lineages there are long divergence times between multicellular species and their unicellular relatives that obscures the genetic signature of multicellular evolution. Moreover, most systems used to study the evolution of multicellularity lack important experimental toolkits to dissect the molecular basis of multicellular evolution. However, the volvocine algae have several advantages to the study the molecular bases of the transition to multicellularity and developmental complexity. Extant volvocine species exhibit a stepwise increase in multicellular and developmental complexity; member species have phenotypes ranging from unicellular, to undifferentiated multicellular, and to differentiated multicellular. This group evolved multicellularity relatively recently (~250 MYA) resulting in a high degree of genomic similarity and conserved synteny that suggests few genetic changes are required for lineages to undergo dramatic shifts in multicellular and developmental complexity. Multicellularity in the volvocines is thought to have evolved by co-option of key genes, such as cell cycle and developmental regulators. However, these co-opted genes appear to be an exception rather than a rule underlying developmental features observed in multicellular volvocine species (Chapter 1). In this work, comparative genomics (Chapters 2 and 3), mathematical modeling (Chapter 2), molecular biology (Chapters 2 and 5), comparative transcriptomics (Chapter 4), and reverse genetics (Chapter 5) approaches are used to provide an integrative view on how gene loss and co-option have impacted the volvocine transition to multicellularity and increased developmental complexity, with implications for other systems. Results show that genetic co-option of fsl1 impacted the evolution of cell-cell adhesion – a key aspect of multicellular life, in undifferentiated multicellular Gonium pectorale. Furthermore, a putative environmental response gene, rlsD, has overlapping targets with its paralog, a cell differentiation regulator in Volvox carteri. Importantly, further results demonstrate that significant loss of conserved genes occurred in the volvocine lineage. These bursts of gene loss likely occurred after the divergence between the lineage of unicellular Chlamydomonas and the ancestor of multicellular volvocines, potentially setting the stage for multicellularity to evolve. Moreover, gene losses are shared across two volvocine families that independently evolved cell differentiation programs, further suggesting that gene loss might have facilitated the evolution of complex phenotypes across the volvocine lineage. Gene loss events likely impact the evolutionary paths and constraints of other genes, potentially resulting in molecular network rewiring and stabilization of the multicellular state. As means to expand these findings to other systems, a mathematical model is developed that suggests the evolution of many multicellular traits might be the product of gene-regulatory and functional innovations that do not necessarily require expansion of genetic repertoires
Exploring settler innocence among early childhood educators in the Osage community: a case study
Full text linkDoctor of EducationDepartment of Educational LeadershipAlex Red CornThe purpose of this revelatory case study was to better understand the curricular decision-making processes of early childhood teachers teaching pre-kindergarten through third grade when constructing learning environments related to Indigenous peoples and cultures in selected public schools in Osage County, Oklahoma. Specifically, this study explored early childhood education teacher unit and lesson planning, as well as perceptions related to confidence, preparedness, and effectiveness when creating learning environments about, with, and for Indigenous peoples and cultures. This study was guided by the theoretical frameworks of settler innocence (Lees et al., 2021), perceived self-efficacy (Bandura, 2012), and Liberating Sovereign Potential (RedCorn, 2020), which centered the role of Osage sovereignty. Community based qualitative research (Johnson, 2017) was also used as an underpinning to guide this study. This study analyzed the perceptions of individual early childhood teachers working across 13 school districts, of which 12 schools were Osage Reservation/Osage County Johnson O’Malley (JOM) site schools. An inductive approach was used to analyze the data collected through semi-structured interviews, questionnaires, and document collection. First and second cycle coding, discourse analysis, and document analysis were used to understand the themes that emerged from the research questions. Findings showed that access barriers within the school influenced teachers’ perceptions of confidence, preparedness, and effectiveness to make decisions related to Native peoples and cultures in their classrooms. Findings also showed that teachers were able to identify what they need to be able to teach Native cultural content and create learning environments that support Native children and cultures. The findings from this study can be used to inform future Indigenous educational decision-making specific to early childhood curriculum and teacher development as it relates to Osage and other Indigenous contexts at the teacher level, policy level, and tribal government level
African American male law enforcement executive perspectives on police-involved shootings of unarmed African American males
Full text linkDoctor of PhilosophyDepartment of Educational LeadershipJeffrey T. ZacharakisA significant gap exists in the literature concerning African American law enforcement executives (AALEEs). Additionally, there is no existing literature concerning AALEEs' perspectives on police-involved shootings of unarmed African American males. When police officers use deadly force, it is often attributed to the victim's behavior, failure to comply with the police officer's commands, or the victim's criminal history(Peeples, 2020). However, at no point the use of lethal force by police officers are attributed to officers' behavior, departmental policies, or training until the incident reaches the court system. Lethal force by police officers brings about an incredible amount of questioning by the general public and politicians. Police-involved shootings of unarmed African American males receive the most significant attention, to the point of protests, demands for answers, and social distrust. The U.S. Justice Department's unsuccessful attempts to track police-involved shootings limited the researcher to seek other published sources for statistical data. The researcher used The Washington Post and the Society Crime & Law Enforcement sites to gather statistical data on the police-involved shootings of unarmed individuals.
This qualitative narrative inquiry explored the viewpoints of AALEEs on police-involved shootings of unarmed African American males. The theoretical framework leaned on the critical race theory (CRT). The research sample included six AALEEs from five police departments. The common comparison was used to analyze the semi-structured interviews, two group discussions, observations, and coding for the findings. The researcher's use of triangulation assisted in ensuring the value of the study. The emergent themes and sub-themes aligned with the theoretical framework to answer the research questions. The findings of this study indicate that better recruitment and hiring processes, diversity training, departmental policy changes, and working as correctional officers before working as police officers on the street could reduce the police-involved shootings of unarmed African American males.
Linking spatial characteristics of urban green space and mental well-being: green space biodiversity and landscape spatial patterns
Full text linkDoctor of PhilosophyLandscape Architecture/Regional & Community PlanningHyung Jin KimDuring the past several decades, much progress has been made in the understanding of how urban green space promotes the mental well-being of urban residents. In particular, the last two decades have witnessed a growing interest in the association between the quantity of urban green space and the effect on residents’ well-being. However, little research has attempted to disentangle the linkage between the structure of urban green space and mental well-being beyond the quantity aspect. To address this question, this dissertation includes a literature review regarding restorative mechanisms influenced by the spatial characteristics of urban green space. Also, this dissertation includes experimental and observational studies: a biodiversity study and a landscape pattern study.
In the biodiversity study, I examined how the biodiversity of campus green space can promote mental well-being of college students by assessing their visual and auditory perceptions of two green spaces having either low or high biodiversity. I employed a 2 by 2 study design, in which 319 students were randomly assigned to one of four treatments: (1) low biodiversity without sound, (2) high biodiversity without sound, (3) low biodiversity with sound, and (4) high biodiversity with sound. In a controlled setting, students viewed on a computer a 360-degree-view video of either a low- or high-diversity site, with or without the natural sounds at each site, that had been recorded on the Kansas State University campus (a grassy lawn area, and a native meadow garden). The restorative status and mood of students were evaluated both pre-intervention and post-intervention via a self-reported survey. The results of this study revealed that neither biodiversity level nor sound by themselves had any significant effect on the mood or restorative status of these college students. However, a significant interaction effect between the visual and auditory perceptions was found. Students who were exposed to a high-biodiversity environment with natural sound conditions were shown to have lower levels of negative mood states compared to those without natural sound conditions.
In the landscape-pattern study, I explored how landscape patterns (i.e., composition and configuration) are associated with the mental health of residents in the city of Chicago. This study used mental health and socioeconomic data from a total of 6,405 residents from 61 Chicago communities in the Healthy Chicago Survey conducted by the Chicago Department of Public Health. High-Resolution Land Cover (HRLC) data were used to calculate urban green space (e.g., trees, grass, and water). Landscape metrics were quantified to measure landscape patterns, including percentage, size, distance, and aggregation of urban green space in 61 community areas across Chicago. The results of this study showed that residents who resided in urban landscapes with small water bodies and that had greater distances between forested areas (owing to the presence of several large urban parks and forests within the Chicago study area) reported less psychological distress. As for total urban green space, there was a lower level of psychological distress in landscapes with a disaggregated distribution of urban green spaces (i.e., multiple small green spaces) in comparison with a single (or a few) large green space(s).
These two studies have implications for landscape design and planning to improve the mental well-being of urban residents. Using both experimental and observational studies, this dissertation is able to contribute to a better understanding of mental restoration mechanisms provided by green spaces within urban environments on both a micro (site-based) and macro (landscape) scale. Furthermore, the study can provide insights into how landscape patterns and biodiversity affect human well-being in order to find a balance between human use and the conservation of nature
The experience of female veterans and health seeking behaviors
Full text linkMaster of ScienceDepartment of Applied Human SciencesJoyce A. BaptistMost military branches began to allow females to serve equally alongside males in the 1940’s. However, militarized masculinity poses a challenge for female service members as they negotiate military norms that continue as they transition to civilian life. Health services provided by the military are aimed to help with deal with life and work challenges. However, it is unclear female service members utilize these services as they are intended. The purpose of this study was to provide a better understanding of how health services were utilized by female Army Veterans based on their personal experiences during military service. The study focused on how these experiences have impacted the decision-making process to seek health services during and/or after service. A phenomenological heuristic qualitative study with 11 female Veterans (M =120 months; Service Range =36 months-328 months) with an overall average of 10 years of Active Army Service was conducted using a semi-structured interview guide. The study elicited participants’ experience with health services offered by the military. Cross-thematic analysis found several themes that prevented participants from accessing health services during active duty: experiences of sexism, sexual harassment, unsupportive leadership, challenges of physical health, and limited access to social, family and health resources. The Vulnerability, Stress and Adaptation model was used to conceptualize the study and make meaning of the findings. Clinical and research implications are discussed
INTEGRATED EXPERIMENTAL AND COMPUTATIONAL ANALYSIS OF MIXED CONVECTION HEAT TRANSFER FROM THE HUMAN HEAD, FULL BODY, AND CLOTHING MICROCLIMATE
No full textDoctor of PhilosophyDepartment of Mechanical and Nuclear EngineeringSteven J. EckelsThermal comfort and heat exchange between the human body and its environment are critical factors in building design, apparel engineering, occupational safety, and the assessment of human performance in diverse climates. Accurately predicting the convective, radiative, and total heat transfer rates for the human body, and specific body segments such as the head, requires an integrated approach that combines controlled experimental measurements with high-accuracy computational fluid dynamics (CFD) modeling. The present study develops and validates a comprehensive computational fluid dynamics (CFD) framework designed to investigate mixed convection heat transfer from two critical human geometries: the human head and the full standing human body. These models represent both localized and whole-body thermal behavior, capturing the distinct effects of buoyancy-driven flows interacting with forced convection. The objective is to derive semi-empirical correlation for the average Nusselt number, providing predictive capability across a wide range of Reynolds, Grashof, and Richardson numbers. This correlation is developed with careful attention to it applicability for complex geometries, such as the head, where curvature, orientation, and local flow separation introduce additional complexities absent in simpler canonical cases like spheres or flat plates.
Building on this, the study further extends its scope to investigate heat transfer through the skin–clothing microclimate, using a fabric-covered cylinder model to represent clothed body segments. In this context, the fabric is treated as a porous medium, with permeability and porosity controlling the degree of airflow penetration and transport through the clothing layer. This addition captures a critical component of real-world heat exchange: the interaction between the skin surface, entrapped air gaps, and textile layers. By modeling the porous zone in detail, including parameters such as viscous and inertial resistance coefficients, porosity, absorption, scattering, and radiation exchange, the study ensures that both transport through the fabric and radiative transfer within the pores are accounted for. This approach enables evaluation of clothing’s thermal insulation in a physically realistic manner.
A high-resolution 3D CFD model of a nude thermal manikin head was created from 3D body scans, meshed with unstructured tetrahedral grids refined near the surface, and simulated in ANSYS Fluent (2020 R2) using the RNG k-ε turbulence model with enhanced wall treatment and discrete ordinates radiation modeling. Air properties were evaluated at the film temperature, and mesh independence testing ensured accuracy. Predicted convective heat transfer coefficients (h_c ) were validated against five experimental cases (0.05–0.5 m/s air velocity; 5–30°C temperature difference), with deviations typically within ±2%. Total and radiative heat fluxes varied spatially, peaking at the nose and forehead due to flow acceleration and plume interaction.
The methodology was extended to a full standing body to compare whole-body and segmental heat transfer. Natural convection coefficients matched published mid-range values (≈3.76 W/m²K), while forced convection coefficients scaled with air velocity in agreement with ASHRAE and Fanger correlations. Radiative coefficients (≈4.93 W/m²K) matched established data. Velocity field analyses revealed buoyancy-driven plume tilting and recirculation patterns that shifted with Richardson number, supporting the mixed-convection modeling approach.
A 2D arm–clothing microclimate model quantified the effects of air gap, fabric conductivity, and emissivity. Results showed smaller gaps reduced natural convection but increased conduction, while higher conductivity and emissivity improved heat loss, demonstrating applicability to clothing design.
This integrated experimental–numerical approach links localized, whole-body, and clothing-related heat transfer, enabling accurate prediction across diverse conditions. Findings support applications in comfort assessment, thermal safety, and protective clothing design, with recommendations for future work including transient modeling, evaporative cooling, and complex garment simulations
HAPPY HEALTH SNACK PROGRAM: AN EFFORT TO ADDRESS FOOD INSECURITY IN SCHOOLS IN SOUTHEAST KANSAS
No full textMaster of Public HealthPublic Health Interdepartmental ProgramLinda K. YarrowThis integrated learning report provides a comprehensive review of my educational experience in completing the Applied Practice Experience (APE). I completed this project with K-State Research and Extension (KSRE) Wildcat Extension District, assisting in the expansion of the Health Happy Snack Project (HHSP). The HHSP is a nutrition curriculum implemented in southeast Kansas to address food insecurity in public schools.
For this APE, I designed a nutrition-based curriculum for school-aged children in kindergarten through second grade. The goal of this project was to promote nutrition and wellness among early elementary students and to increase their knowledge of childhood nutrition and the MyPlate guidelines. The curriculum included nutrition lessons covering MyPlate categories, as well as hydration, handwashing, and food allergies. The lessons also included physical activity, tasting opportunities, in-class activities, and send-home recipes to promote family involvement after the in-school lessons. Additionally, I presented this curriculum to Blue Valley school nurses as part of professional development, offering one hour of credit for continuing education units (CEUs). I was also able to pilot the first lesson of the curriculum, hand washing, in local first and second-grade classrooms. I received feedback from nurses after the CEU presentation, and teachers following the handwashing lesson. This project allowed me to synthesize skills in program planning, health communication, and evaluation acquired throughout the MPH program