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- Creators: School of Life Sciences
- Creators: Sweazea, Karen
- Status: Published
Description
For animals that experience annual cycles of gonad development, the seasonal timing (phenology) of gonad growth is a major adaptation to local environmental conditions. To optimally time seasonal gonad growth, animals use environmental cues that forecast future conditions. The availability of food is one such environmental cue. Although the importance of food availability has been appreciated for decades, the physiological mechanisms underlying the modulation of seasonal gonad growth by this environmental factor remain poorly understood.
Urbanization is characterized by profound environmental changes, and urban animals must adjust to an environment vastly different from that of their non-urban conspecifics. Evidence suggests that birds adjust to urban areas by advancing the timing of seasonal breeding and gonad development, compared to their non-urban conspecifics. A leading hypothesis to account for this phenomenon is that food availability is elevated in urban areas, which improves the energetic status of urban birds and enables them to initiate gonad development earlier than their non-urban conspecifics. However, this hypothesis remains largely untested.
My dissertation dovetailed comparative studies and experimental approaches conducted in field and captive settings to examine the physiological mechanisms by which food availability modulates gonad growth and to investigate whether elevated food availability in urban areas advances the phenology of gonad growth in urban birds. My captive study demonstrated that energetic status modulates reproductive hormone secretion, but not gonad growth. By contrast, free-ranging urban and non-urban birds did not differ in energetic status or plasma levels of reproductive hormones either in years in which urban birds had advanced phenology of gonad growth or in a year that had no habitat-related disparity in seasonal gonad growth. Therefore, my dissertation provides no support for the hypothesis that urban birds begin seasonal gonad growth because they are in better energetic status and increase the secretion of reproductive hormones earlier than non-urban birds. My studies do suggest, however, that the phenology of key food items and the endocrine responsiveness of the reproductive system may contribute to habitat-related disparities in the phenology of gonad growth.
Urbanization is characterized by profound environmental changes, and urban animals must adjust to an environment vastly different from that of their non-urban conspecifics. Evidence suggests that birds adjust to urban areas by advancing the timing of seasonal breeding and gonad development, compared to their non-urban conspecifics. A leading hypothesis to account for this phenomenon is that food availability is elevated in urban areas, which improves the energetic status of urban birds and enables them to initiate gonad development earlier than their non-urban conspecifics. However, this hypothesis remains largely untested.
My dissertation dovetailed comparative studies and experimental approaches conducted in field and captive settings to examine the physiological mechanisms by which food availability modulates gonad growth and to investigate whether elevated food availability in urban areas advances the phenology of gonad growth in urban birds. My captive study demonstrated that energetic status modulates reproductive hormone secretion, but not gonad growth. By contrast, free-ranging urban and non-urban birds did not differ in energetic status or plasma levels of reproductive hormones either in years in which urban birds had advanced phenology of gonad growth or in a year that had no habitat-related disparity in seasonal gonad growth. Therefore, my dissertation provides no support for the hypothesis that urban birds begin seasonal gonad growth because they are in better energetic status and increase the secretion of reproductive hormones earlier than non-urban birds. My studies do suggest, however, that the phenology of key food items and the endocrine responsiveness of the reproductive system may contribute to habitat-related disparities in the phenology of gonad growth.
ContributorsDavies, Scott (Author) / Deviche, Pierre (Thesis advisor) / Sweazea, Karen (Committee member) / McGraw, Kevin (Committee member) / Orchinik, Miles (Committee member) / Warren, Paige (Committee member) / Arizona State University (Publisher)
Created2014
Description
Reproduction is energetically costly and seasonal breeding has evolved to capitalize on predictable increases in food availability. The synchronization of breeding with periods of peak food availability is especially important for small birds, most of which do not store an extensive amount of energy. The annual change in photoperiod is the primary environmental cue regulating reproductive development, but must be integrated with supplementary cues relating to local energetic conditions. Photoperiodic regulation of the reproductive neuroendocrine system is well described in seasonally breeding birds, but the mechanisms that these animals use to integrate supplementary cues remain unclear. I hypothesized that (a) environmental cues that negatively affect energy balance inhibit reproductive development by acting at multiple levels along the reproductive endocrine axis including the hypothalamus (b) that the availability of metabolic fuels conveys alterations in energy balance to the reproductive system. I investigated these hypotheses in male house finches, Haemorhous mexicanus, caught in the wild and brought into captivity. I first experimentally reduced body condition through food restriction and found that gonadal development and function are inhibited and these changes are associated with changes in hypothalamic gonadotropin-releasing hormone (GnRH). I then investigated this neuroendocrine integration and found that finches maintain reproductive flexibility through modifying the release of accumulated GnRH stores in response to energetic conditions. Lastly, I investigated the role of metabolic fuels in coordinating reproductive responses under two different models of negative energy balance, decreased energy intake (food restriction) and increased energy expenditure (high temperatures). Exposure to high temperatures lowered body condition and reduced food intake. Reproductive development was inhibited under both energy challenges, and occurred with decreased gonadal gene expression of enzymes involved in steroid synthesis. Minor changes in fuel utilization occurred under food restriction but not high temperatures. My results support the hypothesis that negative energy balance inhibits reproductive development through multilevel effects on the hypothalamus and gonads. These studies are among the first to demonstrate a negative effect of high temperatures on reproductive development in a wild bird. Overall, the above findings provide important foundations for investigations into adaptive responses of breeding in energetically variable environments.
ContributorsValle, Shelley (Author) / Deviche, Pierre (Thesis advisor) / McGraw, Kevin (Committee member) / Orchinik, Miles (Committee member) / Propper, Catherine (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2018
Description
Birds have unusually high plasma glucose concentrations compared to mammals of similar size despite their high metabolic rate. While birds use lipids as their main source of energy, it is still unclear how and why they maintain high plasma glucose concentrations. To investigate a potential underlying mechanism, this study looks at the role of lipolysis in glucose homeostasis. The purpose of this study is to examine the effects of decreased glycerol availability (through inhibition of lipolysis) on plasma glucose concentrations in mourning doves. The hypothesis is that decreased availability of glycerol will result in decreased production of glucose through gluconeogenesis leading to reduced plasma glucose concentrations. In the morning of each experiment, mourning doves were collected at the Arizona State University Tempe campus, and randomized into either a control group (0.9% saline) or experimental group (acipimox, 50mg/kg BM). Blood samples were collected prior to treatment, and at 1, 2, and 3 hours post-treatment. At 3 hours, doves were euthanized, and tissue samples were collected for analysis. Acipimox treatment resulted in significant increases in blood glucose concentrations at 1 and 2 hours post- treatment as well as renal triglyceride concentrations at 3 hours post-treatment. Change in plasma free glycerol between 0h and 3h followed an increasing trend for the acipimox treated animals, and a decreasing trend in the saline treated animals. These results do not support the hypothesis that inhibition of lipolysis should decrease blood glycerol and blood glucose levels. Rather, the effects of acipimox in glucose homeostasis appear to differ significantly between birds and mammals suggesting differing mechanisms for glucose homeostasis.
ContributorsKouteib, Soukaina (Author) / Sweazea, Karen (Thesis director) / Deviche, Pierre (Committee member) / Chandler, Douglas (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor)
Created2015-05
Description
The development of safe and effective vaccines has been one of the greatest public achievements of the 20th century. However, there is still considerable public debate about the relative health costs and benefits of vaccines, and the information and misinformation spread through these debates can have a direct impact on vaccination and whether or not herd immunity will continue in the United States for different diseases. To understand perceptions of vaccine risks and effectiveness among young adults in the U.S., this study describes Arizona State University students' perceptions of the harms and benefits of vaccines. A preliminary free list (n=30) identified what vaccines ASU college students were most likely to recall spontaneously. The six vaccines most commonly mentioned by ASU students were: influenza (flu), chickenpox, HPV, polio, MMR, and smallpox. Using these top six vaccines, we then developed a second survey about the knowledge and perceptions of each of these vaccines and vaccines as a whole. We found that students generally perceived vaccines as safe and important to their health, but they maintained an overall lack of understanding of how vaccines work and what they protect against. While this study is only a preliminary investigation into the perceptions of ASU college students on six commonly mentioned vaccines, this could lead to investigations on how to educate and promote the usage of vaccines to college students.
ContributorsGilson, Jacob (Co-author) / Sutton, Carly (Co-author) / Hruschka, Daniel (Thesis director) / Ruth, Alissa (Committee member) / W. P. Carey School of Business (Contributor) / School of Human Evolution and Social Change (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2017-12
Description
Background Osteoporosis is a major health problem that can occur in people of all ages. It can stem from poor bone health during childhood and adolescence. It hinders independent living, impacts social living, reduces participation in physical activity, and increases risk of fractures and physical pain. In addition to age, gender, race, physical activity and diet, sleep is considered to be a risk factor in the development of osteoporosis in both the young and elderly population. Bone-specific alkaline phosphatase, a bone formation biomarker was measured to determine osteoporotic risk while an actigraphy device was used to measure sleep efficiency in college students. Objective The purpose of this study is to evaluate the relationship between sleep efficiency and bone-specific alkaline phosphatase levels. Recognition of any association may help in understanding how sleep is related to bone health. Methods Twenty-seven participants were recruited with the use of flyers distributed on campus and in residential halls, social media, email, and student newsletters. Bone-specific alkaline phosphatase biomarker was measured using human specific enzyme-linked immunosorbent assay (ELISA). Sleep data were collected from participants who wore ActiWatch for 7 days and completed a 7-night sleep diary. Linear and multiple regression analysis were performed to evaluate association between B-ALP (outcome) and sleep efficiency while adjusting for covariates (age, BMI, race, gender). Results and Conclusions Overall, there was no significant association between sleep efficiency and bone-specific alkaline phosphatase. Gender, however, showed a significant influence on the levels of bone-alkaline phosphatase. This is supported by a study that found higher bone turnover marker in males than in females. The result from the study could be due to limitations such as small sample size. More participants may provide a better comparison or association between variables. Genetic factors are believed to influence the outcome of the study as genetics can influence rate of bone loss or formation. Findings may be beneficial for public health and policy initiatives and allow health / nutrition educators to more adequately encourage proper habits such as physical activity, healthy diet and sufficient sleep for good bone health.
ContributorsLadipo, Evelyn Irawola (Author) / Whisner, Corrie (Thesis director) / Mahmood, Tara (Committee member) / School of Life Sciences (Contributor) / School of Nutrition and Health Promotion (Contributor) / Barrett, The Honors College (Contributor)
Created2018-05
Description
The purpose of this study is to assess the factors that motivate and influence 18-24-year-olds, compared to those of other age groups, to volunteer, specifically in local hospitals. Volunteers play an integral role towards sustaining nonprofit organizations (NPOs). For this reason, volunteers have the potential to impact the success and effectiveness of local NPOs including nonprofit hospitals such as Banner Health, Mayo Clinic, and HonorHealth. These hospitals rely on the services provided by volunteers to help facilitate their patient care and achieve their missions. An important component of the hospitals’ volunteer programs must focus on the recruitment and retention of volunteers. According to the Bureau of Labor Statistics, volunteer rates are lowest among 20-24-year-olds. Since most college students encompass the 18-24 age range, understanding the factors that motivate and influence them could indicate why there is a low number of hospital volunteers in this age group. ASU students were surveyed regarding their volunteer history, volunteer motivations, and volunteer constraints. Their responses were compared to survey results from local hospital volunteers to look for significant differences or similarities which are highlighted in this study. A total of 183 ASU students between the ages of 18 and 24 completed the survey, and 58 of those students identified as a prior or current hospital volunteer. Three ASU students participated in a focus group. Out of the five Arizona nonprofit hospitals contacted, only one participated in the study. Banner Thunderbird Medical Center (BTMC) had 34 active hospital volunteers complete the survey. The BTMC volunteers who participated in the study were between 14 and 83 years old with the most common age being 69 years old.
ContributorsFasani, Sophia Maria (Author) / Wang, Lili (Thesis director) / Lyons-Mayer, Michelle (Committee member) / School of Community Resources and Development (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2019-05
Description
The transition to college has been identified as a vulnerable period for weight gain and the onset of obesity. Research has shown that the gut microbiota is different in obese compared to lean individuals, but a period of weight gain has never been studied in free-living individuals. The objective of this longitudinal, observational study was to assess the association between changes in the intestinal microbiota and weight-related outcomes in healthy college students living in on-campus dormitories at Arizona State University (n=39). Anthropometric measures and fecal samples were collected at the beginning and end of the school year, and microbial relative abundance for A. muciniphila, F. prausnitzii, R. gnavus, and L. acidophilus was measured through qPCR analyses. In this population, body mass index (BMI) and waist circumference (WC) increased by 0.97 ± 1.28 kg/m2 and 2.64 ± 4.90 cm, respectively. Wilcoxon-Rank tests revealed that R. gnavus fold change was significantly different between groups of weight loss/maintenance and weight gain ≥ 5% body weight (0.14 [-0.21, 0.64], n=24 vs. -0.14 [-0.92, 0.05], n=15, respectively; p=0.028). Correlation analyses suggested a significant negative association between A. muciniphila fold change and both % WC change and % BMI change (r= -0.66; p<0.01 and r= -0.33; p=0.04, respectively). However, multivariate regression analysis controlling for sex and race/ethnicity showed a significant association between A. muciniphila and % WC change, but not % BMI change (R2= 0.53; p<0.01 and R2= 0.24; p=0.15). F. prausnitzii was not associated with weight-related outcomes in this sample. L. acidophilus was excluded from study analyses after subsequent qPCR trials revealed no amplification in participant samples. Overall, this was the first study to show a relationship between A. muciniphila fold change and weight-related outcomes over a period of weight gain. Specifically, A. muciniphila was strongly negatively associated with WC in this sample. Further research is needed to more accurately describe these associations and potential mechanisms associated with the shift in gut microbiota observed with weight gain. Findings from future research may be used to develop interventions for college students aiming to shift the gut microbiota to prevent weight gain.
ContributorsJourney, Elizabeth (Author) / Whisner, Corrie M (Thesis advisor) / Bruening, Meredith (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2017
Description
Most individuals entering college are taking responsibility for their own health for the first time. Students are used to having a parent or guardian nearby to diagnose and provide remedies for common health issues. Entering college, whether in a different city or just down the road, means they must assume those responsibilities themselves. Navigating that transition can be difficult for college students. A large majority of students turn to internet health resources, such as WebMD, for health information. However, studies show that despite overall internet savvy, college students are not very skilled at finding legitimate health information online. Therefore, a health resource designed specifically for college students would be a valuable resource for many students at ASU. Working with local Phoenix physician Doug Lakin, I and a team of other Barrett students revised Dr. Lakin's healthcare guide, Thrive 101: Health & Wellness for College Students. I was responsible for the guide's second chapter, which provides information on specific illnesses and injuries. I conducted a literature review to discover the best practices for communicating medical information. I found that using short sentences, simple words, bullet point lists, numbered lists, and subheadings improved the effectiveness of a health resource. I also found that health information seekers want resources to be tailored specifically for them. They want personalized resources. Personalization means including health information that the intended reader wants, excluding the health information the reader does not want, as well as featuring personal anecdotes from individuals like the reader dealing with health problems like the reader's. I applied what I discovered to Thrive 101. I reorganized the chapter I was assigned, incorporating subheadings and clear organization of the information. I also eliminated information I judged irrelevant to college students and brainstormed what information was missing that college students would benefit from. At this time, the revision team has not gotten to the point where we are researching and writing new information, but we do have lists of items we want to include. The information already in the guide I reformatted into bulleted and numbered lists where possible. As with the new information, we have not begun to revise the guide on a prose level, shortening the sentences and simplifying the vocabulary, but we intend to work into the summer to finish our revisions.
ContributorsAbboud, Carolina (Author) / Maienschein, Jane (Thesis director) / O'Neil, Erica (Committee member) / Lakin, Douglas (Committee member) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
My research aims to determine the effectiveness of meditation and sleep applications (apps) on the reduction of anxiety and stress in college students, with a focus on sedative piano music. Results showed a significant reduction of stress and anxiety levels in college students when listening to sedative piano music versus non-sedative piano music. Music along with other therapy modalities in meditation and sleep apps show promise in reducing students’ anxiety and stress and promoting their successes.
ContributorsPantha, Bidur (Author) / Brian, Jennifer (Thesis director) / Patten, Kristopher (Committee member) / School of Molecular Sciences (Contributor) / School of Life Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
This thesis aimed to create a curriculum for college students to increase their health insurance literacy and to evaluate the impact of the curriculum on participants' confidence. The curriculum for college students consisted of pre-recorded presentation slides covering six health insurance topics, pre- and post-tests, and evaluation questions. Canvas was used to house the curriculum. At the time of evaluation, a total of 12 participants had completed all aspects of the curriculum. The curriculum was evaluated through questions provided at the end of each module. It was found that participants felt the curriculum to be clear and helpful. Moreover, participants reported an increase in confidence, decreased confusion, and were interested in learning more about health insurance such as enrollment. Both the creation of a curriculum and the impact on participants' confidence was successful. At a later point in time, an analysis of the pre- and post-tests will be assessed to determine if the curriculum was effective at increasing health insurance literacy.
ContributorsHernandez, Talia Itzel (Author) / Koskan, Alexis (Thesis director) / Berkel, Cady (Committee member) / School of Politics and Global Studies (Contributor) / School of Life Sciences (Contributor) / School of Human Evolution & Social Change (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05