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Browsing by Author "Graham, James, committee member"

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    Advancing the transition to employment for young adults with intellectual disabilities through assessment, self-report, and learning from lived experience
    (Colorado State University. Libraries, 2024) Parsons, Cristina C., author; Persch, Andrew C., advisor; Schmid, Arlene A., advisor; Graham, James, committee member; Hickey, Matt, committee member; Cleary, Dennis, committee member
    This dissertation seeks to advance the transition to employment for young adults with intellectual disabilities through three distinct approaches. First, we explore the construct of self-determination specifically as it pertains to the employment of young adults with intellectual disabilities. Second, we intentionally refine an assessment of "vocational fit" for self-report by young adults with intellectual disabilities. Third, we examine how young adults with intellectual disabilities and their families experience barriers to engagement in self-advocacy in navigating complex systems intended to assist with the transition to work. In Study 1, we found evidence to support the idea that the context of employment plays a bigger role in the construct of self-determination than is explicated in current self-determination theories. We learned in Study 2 that young adults with intellectual disabilities can interpret and respond appropriately to a self-report version of a vocational fit assessment. In Study 3, findings taught us that the complexities of support systems intended to assist young adults with intellectual disabilities in reaching their employment goals drastically affects their and their families' ability to advocate for their rights and needs. Taken together, these studies present a multi-faceted approach to improved assessment, inclusion, and access necessary for the successful transition to employment for young adults with intellectual disabilities.
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    Chained sweet: nanoconfinement of carbohydrates
    (Colorado State University. Libraries, 2017) Wiebenga-Sanford, Benjamin P., author; Levinger, Nancy, advisor; Fisher, Ellen, committee member; Barisas, George, committee member; Menoni, Carmen, committee member; Graham, James, committee member
    Sugars and other carbohydrates play critical roles in a vast array of chemical and biological systems. In biological systems, the carbohydrates' environments are highly heterogeneous, including interfaces in cells and subcellular organelles, and on proteins. Nanoconfined aqueous environments also feature in these naturally and artificially occurring systems. The studies reported here explore glucose and other carbohydrate molecules, specifically ethylene glycol, glycerol, meso-erythritol, xylitol, sorbitol, myo-inositol, and trehalose, in the nanoconfined environments offered by reverse micelles, also referred to as water-in-oil mocroemulsions. I investigate how the nanoconfinement affects the carbohydrate behavior and how the carbohydrates affect the reverse micelles. I report the effect of carbohydrates on report the loading-ability of carbohydrates into the reverse micelles, demonstrate the location of the carbohydrates in the reverse micelle water pools, and show an unexpected effect where the carbohydrates to add to the reverse micelle volume without appearing to take up space. I use EXSY or Z-Z exchange spectroscopy to show that that the exchange rate between water and carbohydrate hydroxyl groups is substantially slower than it is in bulk aqueous solution and that it does not depend on hydrogen bonding between the carbohydrate and surfactant headgroup. These reverse micellar environments can provide unique platforms for confinement and as model systems for biological constructs. Results from these studies provide fundamental information to help us understand, predict and control carbohydrates, in particular glucose, in biological systems. Finally, I report on experiments utilizing steady-state fluorescence spectroscopy to characterize the nature of the reverse micellar interior, specifically the local "viscosity" via the response of a dye probe molecule. I also detail experiments that aimed to measure the aggregation number, that is, the number of surfactant molecules in the reverse micelles of varying water and carbohydrate loading. Although interesting, these studies did not yield the desired results.
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    Examining the efficacy of the empowerment course for young adults with disabilities: training for postsecondary education and employment
    (Colorado State University. Libraries, 2020) Sjostrand, Rachel L., author; Davies, Patricia L., advisor; Graham, James, committee member; Hepburn, Susan, committee member
    Objective. Current secondary transition programs have been less than satisfactory in student outcomes and have not adequately addressed skills necessary to transition into the adult world for students with intellectual disabilities (ID) and autism spectrum disorders (ASD). Individuals with ID and ASD have lower rates of attending postsecondary education, obtaining and maintaining a job, and living independently compared to their peers. The Empowerment Course is a one-year, postsecondary transition program designed to facilitate successful employment and/or educational outcomes for transition aged (18-26) young adults with disabilities. Two occupational therapists (OTs) were the instructors for the course, along with graduate OT students as mentors for participants enrolled in the Empowerment Course. Method. Students who completed the full academic year of the Empowerment Course over the past three years were included in analyses (n = 16). Students and instructors completed questionnaires at the beginning of the fall semester and at the end of the spring semester. A pretest-posttest design was used to assess student's perceived self-efficacy, competence in their job-seeking skills, quality of life, self-advocacy skills, and their ability to set and work towards goals. A series of t-tests were run to analyze the data. Student's attendance for lectures and labs of the Empowerment Course was also examined. Results. Students demonstrated significant improvements in goal attainment, job-seeking skills confidence, and in their self-advocacy skills. On average, student's attendance was greater than 95% for lectures and labs. Conclusions. Results suggest that participation in the Empowerment Course for students with ID and ASD may develop life skills beyond what is taught in high school transition programs. It was feasible to have OTs as instructors for this postsecondary transition program and to facilitate effective results.
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    Exploring the impacts of nanoconfinement using nuclear magnetic resonance (NMR) spectroscopy
    (Colorado State University. Libraries, 2022) Miller, Samantha L., author; Levinger, Nancy, advisor; Krummel, Amber, committee member; Crans, Debbie, committee member; Graham, James, committee member
    The chemical reactivity of molecules is typically studied under bulk aqueous conditions in the research laboratory. Although this standard may be appropriate for processes destined to be scaled up for industrial purposes, it ignores the fact that a great deal of the chemistry underlying physiological reactions occur in confined environments, like cellular organelles, protein pockets, or porous interfaces. The dissertation begins by describing the methodology for synthesizing size tunable reverse micelles, or surfactant enveloped nanodroplets. After physical perturbation, the ternary mixture of polar (usually aqueous), nonpolar, and amphiphilic surfactant self-assemble. Two small molecules, glucose and urea, were studied in these nano environments using a combination of analytical techniques including dynamic light scattering, differential scanning calorimetry, and molecular dynamics simulations that complemented the myriad nuclear magnetic resonance (NMR) spectroscopy studies. Quantification of single hydrogen exchange between glucose and water using exchange spectroscopy NMR in conjunction with custom MatLab code revealed that confinement of glucose and water within 8-10 nanometer reverse micelles slows the process of exchange by introducing a quantifiable energy barrier of ~75 kJ/mol. Deuterium NMR spectroscopy provided evidence for hydrogen tunneling below 283 K, a surprisingly high temperature for this phenomenon. The same robust methods of kinetic and structural analysis were used to characterize urea in water reverse micelles. Results showed that in addition to its well-known ability to denature proteins, urea can disrupt amphiphilic membranes and cause a ten-fold increase in the membrane surface area at low temperatures ~273 K as a result of this destabilization. Finally, the use of fluorine NMR spectroscopy demonstrated that the reverse micelle nanodroplet environments could achieve higher ionic strengths (~9.0 M) with simple divalent salts than possible in standard bulk solutions (~5.0 M). Together, these results presented compelling evidence that utilization of reverse micelle nanodroplets could provide alternative environments to facilitate previously inaccessible, novel conditions.
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    Interaction of [VO₂(MA)₂]⁻ with model membranes: relevance to insulin enhancing effects of BMOV and its oxidized form
    (Colorado State University. Libraries, 2010) Schoeberl, Samantha Kay, author; Roess, Deborah, advisor; Graham, James, committee member; Crans, Debbie, committee member
    Anti-diabetic vanadium-containing compounds and salts reportedly have effects on the overall organization of the cytoskeleton and the plasma membrane of cells. For ligand-mediated signaling, appropriate cytoskeletal and membrane lipid organization is essential for down-stream signaling to occur. A number of vanadium-containing compounds and salts are of interest because of their effects on these important cellular structures. Promising results in regulating diabetic symptoms such as glucose and lipid metabolism have been shown to result from the use of various anti-diabetic vanadium drugs. Their effects on the cytoskeleton and plasma membrane are reviewed Chapter I. Due to the importance of membrane interactions of vanadium-containing compounds with insulin-enhancing activity in ligand-mediated signaling, two simple membrane model systems were used to investigate the interactions of an oxidized metabolite of bis(maltolato)oxovanadium(IV) with model lipid interfaces. Studies were carried out using multinuclear NMR spectroscopy with a focus on 1H NMR techniques. In Chapter II we demonstrate that there were slight changes in 1H NMR spectra indicating that this BMOV metabolite was able to penetrate the lipid interface. These findings are important in understanding the pharmacologic mechanism of action of this anti-diabetic compound in cells and intact animals.
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    Investigating the iso principle: the effect of musical tempo manipulation on arousal shift
    (Colorado State University. Libraries, 2020) Goldschmidt, Daniel, author; Knight, Andrew, advisor; LaGasse, A. Blythe, committee member; Graham, James, committee member
    The iso principle is a well-known concept in music therapy practice wherein a clinician meets a client at a current body state with a musical element, then moves them to a new body state by modulating the musical element. However, few scholars agree on what bodily states and musical elements define the iso principle, which limits music therapy clinicians' targeted application of the concept. Further, it appears there have been no studies objectively addressing physiologic change during the iso principle. The purpose of this study was to investigate arousal shift during iso principle-informed tempo change in a musical stimulus. Arousal was measured via physiological responses (galvanic skin response [GSR]) and self-perception (self-assessment manikin [SAM]). Participants' (n = 9) took part in a randomized block design with control in which they completed a mindfulness-based intervention before listening to one of three five-minute auditory stimuli: 1) an iso principle-informed song, 2) a compensation principle-informed song, and 3) a spoken short story. GSR data from participants did not show statistically significant differences between the iso principle and compensation principle, but did show significant differences between musical conditions and speech. While the music was designed to increase arousal using the iso principle, overall there was a reduction in arousal levels over the experimental period. Participants' self-ratings of their arousal shifts (SAM scores of arousal) showed a perceived increase in arousal during all conditions. Limitations, clinical implications, and future directions are discussed.
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    Membrane organization of luteinizing hormone receptors during signal transduction
    (Colorado State University. Libraries, 2010) Wolf-Ringwall, Amber L., author; Roess, Deborah, advisor; Miller, Charles, committee member; Graham, James, committee member; Barisas, B. George, committee member
    Mechanisms involved in signal transduction by luteinizing hormone (LH) receptors are important for regulating key events in mammalian reproduction, such as ovulation, sex hormone production and maintenance of pregnancy. Studying the organization of LH receptors in the plasma membrane during hormone-mediated signaling provides insights into the protein interactions needed for important physiological responses. We used biochemical and biophysical methods to examine the role of the plasma membrane in contributing to LH receptor desensitization. Using single particle tracking and sucrose gradient ultracentrifugation, we determined that individual human LH receptors are confined in small membrane compartments and localize in membrane rafts for several hours following desensitization. These receptors do not demonstrate signaling via cyclic adenosine monophosphate (cAMP) while they are confined, suggesting that the microenvironment within these compartments may be different for desensitized versus actively signaling receptors. We also investigated self-association of human LH receptors using homotransfer fluorescence resonance energy transfer (homo-FRET) and fluorescence correlation spectroscopy. We determined that human LH receptors self-associate following desensitization and in response to increasing concentrations of human chorionic gonadotropin (hCG). LH receptors demonstrated the highest degree of aggregation in response to saturating concentrations of 100 nM hCG. Using single particle tracking, we examined whether native LH receptors expressed on KGN human granulosa-like tumor cells, or M l7 human neuroblastoma cells, become confined in small membrane compartments in response to hormone binding. We found that confinement of native LH receptors in small plasma membrane compartments depended on hCG concentration. With increasing concentrations of hCG, more LH receptors became confined in small membrane compartments with an average diameter of less than 100 nm. These receptors also exhibited slower rates of lateral diffusion. We reported the movement of non-functional hormone-receptors, labeled with deglycosylated hCG, into small membrane compartments in response to hCG treatment that saturated other available LH receptors on the membrane. This finding suggests that interactions between functional and non-functional LH receptors may occur in membrane microdomains during signal transduction.
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    Optimizing storage of bovine sperm between semen collection and sexing
    (Colorado State University. Libraries, 2010) Anema, Jennifer Lea, author; Seidel, George, Jr., advisor; Graham, James, committee member; Peel, Richard Kraig, committee member
    To view the abstract, please see the full text of the document.
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    Predicting occupational therapy service utilization in agitated or sedated patients in the neurocritical care unit
    (Colorado State University. Libraries, 2020) Messenger, Lindsey, author; Malcolm, Matthew, advisor; Graham, James, committee member; Davalos, Deana, committee member
    Purpose: The extent by which patient arousal levels relate to occupational therapy (OT) utilization in the neurocritical care unit (NCCU) is unknown. Understanding how arousal levels in patients influence their ability to engage with OT interventions will better equip therapists to provide appropriate treatments to patients. This study sought to examine whether the Richmond Agitation and Sedation Scale (RASS) is independently associated with OT service utilization. Methods: This cross-sectional retrospective study utilized data obtained from electronic health records from 1,134 patients admitted to the neurocritical care unit at an academic acute care hospital between May 2013 and September 2015. Separate regression models identified the predictive ability of the RASS and other patient factors in relationship to the dependent variables of receipt of OT in the neurocritical care unit (NCCU) and OT intervention categories. The independent variable was initial RASS score. Covariates included patient age, gender, minority status, Charlson Comorbidity Index, and initial Glasgow Coma Scale (GCS). OT intervention categories were: (1) self-care/home management, (2) functional-cognitive, and (3) therapeutic exercise. Results: 420 patients received OT in the NCCU (37.0%). The initial RASS score was not a significant predictor of receipt of OT, however, higher initial GCS and CCI scores and patient age were associated with greater odds of receiving OT. The initial RASS score was not a significant predictor of OT intervention type Higher CCI and initial GCS scores and increased patient age were associated with greater odds of receiving therapeutic exercise intervention. Increased initial GCS score was found to be associated wither greater odds for receiving self-care/home management interventions. Higher patient age was found to be associated with a higher odd of receiving functional-cognitive interventions. Conclusion: The initial RASS score was not a significant predictor of OT receipt or intervention type, suggesting that there may be other factors that are more influential for therapists to use for clinical reasoning. There could be a need for a different measures or education on potential OT roles related to different on patient arousal levels. Keywords: neurological rehabilitation, occupational therapy, arousal levels, agitation, sedation, neuro-intensive care, intervention
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    Remote learning: the impact of the COVID-19 pandemic on music therapy students' perceived skills and concerns regarding internships
    (Colorado State University. Libraries, 2022) Schmidt, Shealyn D., author; Knight, Andrew, advisor; LaGasse, Blythe, committee member; Graham, James, committee member
    The purpose of this study was to examine the self-perceived skills and concerns of music therapy (MT) undergraduate and graduate equivalency students, who studied in the United States during the COVID-19 pandemic. This study implemented a cross-sectional survey design, using Likert scale questions from Clements-Cortés's 2019 study about music therapy students' self-perceived skills and concerns regarding internship, published in the Journal of Music Therapy. The researcher used validation measures to condense the original survey from 53 to 25 questions. Participants were also asked to indicate the amount of remote learning (high, medium, or low), student level (graduate equivalency or undergrad) and their current internship status. A Qualtrics survey link was sent to students via music therapy student organizations' social media pages, and resulted in a sample of fifty-two student participants. Data were analyzed using descriptive statistics and a Kruskal Wallis H test with Bonferroni correction was used to determine significant differences between perception of skill or concerns and the amount of remote learning or student level (grad or undergrad). The highest self-perceived skill of UG participants was Professional Relationships and the lowest was Piano Improvisation. The highest self-perceived skill of GE students was Creative MT Technique Knowledge and Use and the lowest was Handling Stress. The highest self-perceived concern of UG was Making Spontaneous Adaptations and the lowest was Handling Session Unpredictability. The highest self-perceived concern of GE was Finances and the lowest was Handling Session Unpredictability. Results indicated that participants perceived benefits and drawbacks of remote learning. The amount of remote learning (high, medium, low) showed significant differences were found for perception of skills among high-remote internship students, and for skills and concerns among students with high in person internship and high-remote practicum categories. The majority of significant results were found in the high-remote practicum category. There were no significant differences found within the in-person practicum category. As compared with pre-internship undergraduate MT students in Clements-Cortés (2019) study, pre-interns in the current study rated themselves as more skilled on 9 of 12 items. However, post-interns in the current study rated themselves as less skilled on all 12 items. Pre-interns in the current study rated themselves as less concerned than pre-interns in Clements-Cortés (2019) study on 9 of 13 items. However, post-interns in the current study rated themselves as less concerned on all 13 items. In MT students' written responses about the impact of remote learning, the most frequently reported disadvantages included fewer in-person experiences and technological difficulties. The most frequent advantages reported included learning (specifically an increase in knowledge) and convenience. Individual perspectives appeared to impact whether certain elements of remote learning were seen as positive or negative thing. At present, the COVID-19 pandemic is ongoing and remote learning technology will likely continue to be used. Further research about the use of remote technology in music therapy education can help to gain insight on how to make the internship and profession more accessible for students.
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    Role of α/β hydroxylase domain containing protein 2 in stallion sperm activation
    (Colorado State University. Libraries, 2019) McQuagge, Matthew, author; Bruemmer, Jason, advisor; Pinedo, Pablo, committee member; Graham, James, committee member; Winger, Quinton, committee member
    Cell signaling pathways involved in stallion sperm activation are not completely understood. Furthermore, failure of equine in vitro fertilization is commonly attributed to an inability to successfully capacitate sperm. Sperm activation describes the process by which sperm undergo capacitation, hyperactivation, and acrosome reaction in preparation for interaction with an oocyte. 2-arachidonoylglycerol (2AG) is found in the human sperm membrane and prevents calcium influx through the CatSper channel. The α/β hydroxylase domain containing protein 2 (ABHD2) is also found in the human sperm membrane and functions as a progesterone receptor. When progesterone binds to ABHD2, it removes 2AG from the membrane allowing CatSper to open, which leads to calcium entrance into the cell, resulting in sperm activation. It is unclear if this mechanism holds true in stallion. Experiments were conducted to test the hypothesis that progesterone causes sperm activation through interaction with ABHD2 by 1) determining whether the ABHD2 receptor exists on stallion spermatozoa, 2) determining if progesterone binds to ABHD2 on stallion spermatozoa and 3) demonstrating the role of ABHD2 in sperm activation through correlations between ABHD2 and hyperactivation and/or acrosome reaction. Immunoblotting identified ABHD2 protein in stallion sperm and immunocytochemistry (ICC) localized the receptor to the tail region of stallion spermatozoa. Immunocytochemistry also demonstrated that ABHD2 binds progesterone by restricting fluorescence exhibited by ABHD2 when incubated with progesterone. Stallion sperm were evaluated for hyperactivation with computer assisted sperm analysis (CASA) following incubation in capacitation medium with either 1) an endogenous activator of sperm; 3 µM progesterone (P4), 2) a positive pharmacological stimulator of hyperactivation not associated with ABHD2; procaine or 3) a known ABHD2-action inhibitor methyl arachidonyl flourophosphatnate (MAFP). MAFP is a serine hydroxylase inhibitor and functions by preventing the removal of 2AG caused by exposure of ABHD2 to progesterone and, thus, limits hyperactivation. Flow cytometry was used to measure the acrosomal status of treated sperm as a subset of the hyperactivation measurements. When MAFP was administered prior to treatment with either P4 and/or procaine the hyperactive movement was inhibited (p < 0.05) in the presence of P4 but did not affect procaine induced activity. Results were similar for all ejaculates. The reduced hyperactivation of sperm when incubated with both progesterone and MAFP illustrates a potential connection between ABHD2 and CatSper. No change in acrosomal status was discovered through incubation with P4, procaine, or MAFP. These results indicate 1) that ABHD2 is present on stallion sperm, 2) that progesterone binds to ABHD2 and 3) that progesterone has the potential for causing hyperactivation but does not affect the acrosome reaction.
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    Teachers' and researchers' beliefs of learning and the use of learning progressions
    (Colorado State University. Libraries, 2017) Clapp, Francis Neely, author; Balgopal, Meena, advisor; Graham, James, committee member; Korte, Russell, committee member; Weinberg, Andrea, committee member
    In the last decade, science education reform in the United States has emphasized the exploration of cognitive learning pathways, which are theories on how a person learns a particular science subject matter. These theories are based, in part, by Piagetian developmental theory. One such model, called Learning Progressions (LP), has become prominent within science education reform. Science education researchers design LPs which in turn are used by science educators to sequence their curricula. The new national science standards released in April 2013 (Next Generation Science Standards) are, in part, grounded in the LP model. Understanding how teachers apply and use LPs, therefore, is valuable because professional development programs are likely to use this model, given the federal attention LP have received in science education reform. I sought to identify the beliefs and discourse that both LP developers and intended LP implementers have around student learning, teaching, and learning progressions. However, studies measuring beliefs or perspectives of LP-focused projects are absent in published works. A qualitative research is therefore warranted to explore this rather uncharted research area. Research questions were examined through the use of an instrumental case study. A case study approach was selected over other methodologies, as the research problem is, in part, bound within a clearly identifiable case (a professional development experience centering on a single LP model). One of the broadest definitions of a case study is noted by Becker (1968), who stated that goals of case studies are "to arrive at a comprehensive understanding of the groups under study" and to develop "general theoretical statements about regularities in social structure and process." (p.233). Based on Merriam (1985) the general consensus in the case study literature is that the assumptions underlying this method are common to naturalistic inquiry with research conducted primarily in the field with little control of variables. Beyond this similarity, different researchers have varying definitions to case studies. Merriam's (1985) provided a summary of the delineations and varying types of case studies. Merriam divided the various case study methods by their functions, with a marked divide between theory building and non-theory building methods. Non-theory building case studies are generally descriptive, and interpretive methods that apply theory to a case or context allow researchers to better understand the phenomena observed (Lijphart, 1971; Merriam, 1985). Conversely, theory building case studies focus on hypothesis generation, theory confirming, theory informing, or theory refuting (Lijphart, 1971; Merriam, 1985). Though there are many definitions and methods labeled as "case studies,' for the purpose of this study, Yin's (1981) definition of a case study will be used. Yin (1981) defined a case study as a method to examine "(a) a contemporary phenomenon in its real-life context, especially when (b) the boundaries between phenomenon and context are not clearly evident" (p. 59). My study seeks to apply theory and study phenomena in their context, as I will examine teachers' practice in context of their respective classrooms. This study focuses on the lived experiences of both teacher and research stakeholders within the study. Specifically, I interviewed teachers who participated in a year-long teacher-in-residence (TiR) program. In addition, researchers/content experts who conceptualized the LP were also interviewed. Because the TiR experience was a form of professional development, I propose to study the impact that it had on participants' perceptions of the LP and any teacher-reported changes in their respective classrooms. However, because beliefs influence the language that we use to describe phenomena (such as learning and teaching), it is informative to also describe patterns in how LP developers explain learning and teaching. Subsequently, the results of this study will inform literature on both science teacher professional development and LPs theory to practice.
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    The use of computer assisted semen analysis to predict fertility in Holstein bulls
    (Colorado State University. Libraries, 2011) Pepper-Yowell, Amanda Rae, author; Enns, Mark, advisor; Crews, Denny, committee member; Blackburn, Harvey, committee member; Graham, James, committee member
    Cryo-preserved semen from 120 Holstein bulls was obtained from three semen companies, which were randomly coded 1:3 to decrease bias, through USDA-ARS, Fort Collins, CO. Computer assisted semen analysis (CASA; HTM-IVOS, Version 10.8, Hamilton Thorne Research, Beverly, MA, USA) was used to assess seminal characteristics and to determine if this was useful for predicting fertility, defined in this study as sire conception rate (SCR). For this study the primary CASA measurements assessed were percent motility, percent progressive, average pathway velocity (VAP), straightline velocity (VSL), curvilinear velocity (VCL), amplitude of lateral head displacement (ALH), beat cross frequency (BCF), straightness (STR), linearity (LIN) and cell size (SIZE). Percent motile and percent progressive sperm cells had means, followed by their standard deviation, of 60.93 ± 10.09 and 32.46 ± 10.06%, respectively with percent motile having the lowest coefficient of variation of 16.72 %. Amplitude of lateral head displacement and BCF were both high when compared to other studies conducted with fresh and cryopreserved semen (Budworth et al., 1988, Farrell et al., 1998) with means, followed by their standard deviation, of 8.45 ± 3.5µm and 30.99 ± 9.27Hz, respectively. Straightness and LIN had means, followed by their standard deviation of 80.74 ± 17.11 and 48.24 ± 16.15%, respectively; SIZE had a mean, followed by its standard deviation, of 8.38 ± 2.88µm2. After initial data exploration the data was fit either untransformed, or transformed. Data was fit untransformed because of the data being normally distributed or because a cubic model fit best. Data was fit transformed to better fit normality requirements, for prediction of CASA values. SIZE appeared to have a cubic relationship with all three velocity parameters (VAP, VCL and VSL). The number of bull samples originating from each semen company is as follows: Semen Company 1(SC1) - 32, Semen Company 2(SC2) -71, and Semen Company 3 (SC3) -17. Semen company, when fit as a fixed effect was found to be significant (P ≤ 0.05) so this study looked at the differences of the least squares means between semen companies. When looking at untransformed data SC1 and SC2 were significantly (P ≤ 0.001) different across VAP, ALH and BCF. The heritability of most seminal parameters was low, with the exception of percent motile (0.793). Percent motile also had the greatest genetic variance when compared to its residual variance. Genetic correlation of VAP, ALH and SIZE with SCR were low (0.05, 0.006, and 0.04 respectively); however, percent motile was moderately genetically correlated with SCR at 0.302. After VAP and ALH were transformed to meet normality requirements, heritability was once again calculated and the heritability of the transformed data was lower than the untransformed data. The genetic correlations between the transformed data and SCR stayed the same (0.052) or improved (0.02) (log10VAP and √ALH, respectively). The low heritabilities of these seminal traits does not make them good candidates for genetic evaluation. Significant differences between semen companies suggest that the methods semen companies use to select bulls, collect semen from bulls, extend semen and store the cryopreserved semen could be different. However, this information is highly proprietary and is difficult to ascertain to truly attribute difference between semen companies. Due to the genetic correlations between CASA values and SCR being low we were unable to use this study's CASA values for genetic prediction of fertility. While CASA values do have an underlying genetic component, environmental effects are too large and physiological processes vary too much to estimate future performance of these bulls' fertility.
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    Translocation of insulin receptors into plasma membrane microdomains in response to insulin and to insulin-enhancing vanadium and chromium compounds
    (Colorado State University. Libraries, 2010) Al-Qatati, Abeer S. A., author; Roess, Deborah, advisor; Crans, Debbie, committee member; Graham, James, committee member; Anthony, Russ, committee member
    We have examined the translocation of insulin receptors into specialized, cholesterol-enriched membrane microdomains called lipid rafts following treatment of RBL-2H3 cells with insulin, bis-maltolatooxovanadium (BMOV) and tris(pyridinecarbxylato) chromium(III) (Cr(pic)3). Isopycnic sucrose gradient ultracentrifugation was used to subfractionate membrane fragments and insulin receptors were identified within low or high buoyant density membrane fractions using insulin receptor-specific antibodies and western blotting. Single particle tracking methods were used to confirm the confinement of individual insulin receptors within small membrane compartments on intact, viable RBL-2H3 cells. We demonstrated that insulin receptors translocate into lipid rafts upon binding insulin or following exposure to BMOV or Cr(pic)3 Phosphorylated insulin receptors also appeared in membrane raft fragments in response to insulin and/or insulin-mimicking compounds. Extraction of cholesterol from lipid rafts disrupted these microdomains and caused a decrease in the number of unphosphorylated and phosphorylated insulin receptors within these compartments. In addition to their ability to induce translocation of insulin receptors into lipid rafts, BMOV and Cr(pic)3 caused an increase in the number of phosphorylated IRS-1 molecules within these membrane fragments. To determine why Cr(pic)3 and BMOV might affect the distribution of insulin receptors in non-raft and raft compartments, membrane fluidity was evaluated in Cr(pic)3 and BMOV treated cells. Fluidity, as suggested by a decrease in lipid packing, was increased following treating 2H3 cells with either BMOV or Cr(pic)3 These results suggest that changes in lipid packing resulting from exposure of cells to either Cr(pic)3 and BMOV may affect the distribution of receptors in non-raft and raft compartments. Increased receptor localization in rafts or small membrane compartments evaluated by single particle tracking studies, would result in increased likelihood of insulin receptor phosphorylation within these signaling platforms. Thus rafts may be an important membrane structures involved in cell signaling events mediated by insulin receptors.