Matching Items (182)
Description
In social insect colonies, as with individual animals, the rates of biological processes scale with body size. The remarkable explanatory power of metabolic allometry in ecology and evolutionary biology derives from the great diversity of life exhibiting a nonlinear scaling pattern in which metabolic rates are not proportional to mass, but rather exhibit a hypometric relationship with body size. While one theory suggests that the supply of energy is a major physiological constraint, an alternative theory is that the demand for energy is regulated by behavior. The central hypothesis of this dissertation research is that increases in colony size reduce the proportion of individuals actively engaged in colony labor with consequences for energetic scaling at the whole-colony level of biological organization. A combination of methods from comparative physiology and animal behavior were developed to investigate scaling relationships in laboratory-reared colonies of the seed-harvester ant, Pogonomyrmex californicus. To determine metabolic rates, flow-through respirometry made it possible to directly measure the carbon dioxide production and oxygen consumption of whole colonies. By recording video of colony behavior, for which ants were individually paint-marked for identification, it was possible to reconstruct the communication networks through which information is transmitted throughout the colony. Whole colonies of P. californicus were found to exhibit a robust hypometric allometry in which mass-specific metabolic rates decrease with increasing colony size. The distribution of walking speeds also scaled with colony size so that larger colonies were composed of relatively more inactive ants than smaller colonies. If colonies were broken into random collections of workers, metabolic rates scaled isometrically, but when entire colonies were reduced in size while retaining functionality (queens, juveniles, workers), they continued to exhibit a metabolic hypometry. The communication networks in P. californicus colonies contain a high frequency of feed-forward interaction patterns consistent with those of complex regulatory systems. Furthermore, the scaling of these communication pathways with size is a plausible mechanism for the regulation of whole-colony metabolic scaling. The continued development of a network theory approach to integrating behavior and metabolism will reveal insights into the evolution of collective animal behavior, ecological dynamics, and social cohesion.
ContributorsWaters, James S., 1983- (Author) / Harrison, Jon F. (Thesis advisor) / Quinlan, Michael C. (Committee member) / Pratt, Stephen C. (Committee member) / Fewell, Jennifer H. (Committee member) / Gadau, Juergen (Committee member) / Arizona State University (Publisher)
Created2012
Description
ABSTRACT This randomized, controlled, double-blind crossover study examined the effects of a preprandial, 20g oral dose of apple cider vinegar (ACV) on colonic fermentation and glycemia in a normal population, with the ultimate intention of identifying the mechanisms by which vinegar has been shown to reduce postprandial glycemia and insulinemia. Fifteen male and female subjects were recruited, ages 20-60y, who had no prior history of gastrointestinal (GI) disease or resections impacting normal GI function, were non-smokers, were non-vegetarian/vegan, were not taking any medications known to alter (glucose) metabolism, and were free of chronic disease including diabetes. Subjects were instructed to avoid exercise, alcohol and smoking the day prior to their trials and to consume a standardized, high-carbohydrate dinner meal the eve prior. There was a one-week washout period per subject between appointments. Breath hydrogen, serum insulin and capillary glucose were assessed over 3 hours after a high-starch breakfast meal to evaluate the impact of preprandial supplementation with ACV or placebo (water). Findings confirmed the antiglycemic effects of ACV as documented in previous studies, with significantly lower mean blood glucose concentrations observed during ACV treatment compared to the placebo at 30 min (p=0.003) and 60 min (p=0.005), and significantly higher mean blood glucose concentrations at 180 min (p=0.045) postprandial. No significant differences in insulin concentrations between treatments. No significant differences were found between treatments (p>0.05) for breath hydrogen; however, a trend was observed between the treatments at 180 min postprandial where breath hydrogen concentration was visually perceived as being higher with ACV treatment compared to the placebo. Therefore, this study failed to support the hypothesis that preprandial ACV ingestion produces a higher rate of colonic fermentation within a 3 hour time period following a high-carbohydrate meal. Due to variations in experiment duration noted in other literature, an additional study of similar nature with an expanded specimen collections period, well beyond 3 hours, is warranted.
ContributorsMedved, Emily M (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2012
Description
The various health benefits of vinegar ingestion have been studied extensively in the<br/>literature. Moreover, emerging research suggests vinegar may also have an effect on mental<br/>health. Beneficial effects of certain diets on mood have been reported, however, the mechanisms<br/>are unknown. The current study aimed to determine if vinegar ingestion positively affects mood<br/>state in healthy young adults. This was a randomized, single blinded controlled trial consisting of<br/>25 subjects. Participants were randomly assigned to either the vinegar group (consumed 2<br/>tablespoons of liquid vinegar diluted in one cup water twice daily with meals) or the control<br/>group (consumed one vinegar pill daily with a meal), and the intervention lasted 4 weeks.<br/>Subjects completed mood questionnaires pre- and post-intervention. Results showed a significant<br/>improvement in CES-D and POMS-Depression scores for the vinegar group compared to the<br/>control. This study suggests that vinegar ingestion may improve depressive symptoms in healthy<br/>young adults.
ContributorsWilliams, Susanna (Author) / Johnston, Carol (Thesis director) / Whisner, Corrie (Committee member) / College of Health Solutions (Contributor) / Barrett, The Honors College (Contributor)
Created2021-05
Description
The development of the Diabetic Physiological state is influenced by the Receptor for Advanced Glycation End Products (RAGE). This receptor was discovered in 1992, and the accumulation of research on this subject has been extensive. Structural characterization studies of the RAGE protein have shown that it is a transmembrane protein that binds a number of different motile ligands. The diversity of ligands that can attach to the binding domain is the primary factor that allows for RAGE to exhibit its wide-range effects on host cells. Two different studies were completed: one study dealt with the role of IAPP in beta cell death, and the second study was related to RAGE influence on cardiomyocytes and, more specifically, it was related to cardiac cell death. After the completion of the two studies, a comprehensive report was written for each topic. The two papers were merged into a single document. Molecular studies are important for understanding the underlying mechanisms that motivate pathophysiological presentation. In addition to a molecular understanding of the development of diabetes, a clinical research study was completed through the examination of appropriate literature sources. This clinical aspect allowed for the progression of different phases in the research process. A relationship between vinegar and lower plasma glucose was found. The exact mechanism behind this relationship will be studied in the future.
ContributorsGonzalez, Matthew Joseph (Author) / Johnston, Carol (Thesis director) / Collins, Michael (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2015-05
Description
Physical activity as a health or nutrition related intervention might stimulate appetite and increase hunger due to increased energy expenditure. This study analyzed the effect of a postprandial 15-minute walk on the hunger and energy intake of 10 obese, pre-diabetic adults. Subjects participated in three 4-hour trials: a walk treatment (consume highly glycemic meal, walk for 15 minutes at a moderate pace, and rest for 4 hours), a fiber treatment (consume highly glycemic meal enriched with soluble fiber and rest for 4 hours), and a control treatment (consume highly glycemic meal without fiber and rest for 4 hours). The effects of each treatment on hunger and energy intake were measured using a Likert scale analysis (ranging from "completely satisfied" to "extremely hungry") at 4 hours post-treatment and pre/ post 24-hour dietary logs. The results showed no significant increase or decrease on hunger or energy intake for both the walk and the fiber treatment compared to the control treatment. This denies the idea that physical activity might increase short-term hunger, and supports the use of physical activity as a viable nutrition related intervention tool.
ContributorsTerrell, Alayna Franci (Author) / Johnston, Carol (Thesis director) / Vega Lopez, Sonia (Committee member) / Barrett, The Honors College (Contributor) / Department of Chemistry and Biochemistry (Contributor)
Created2015-05
Description
This study was conducted to observe the effects of vitamin C supplementation upon the expression of sICAM-1 in asthmatic subject. Two groups were created, each with a sample size of 4 subjects. One group was the vitamin C group (VC) and the other was the placebo group (PL). The study was analyzed through observing concentrations of biomolecules present within samples of blood plasma and nasal lavages. These included vitamin C, sICAM-1 expression, and histamine. The following P-values calculated from the data collected from this study. The plasma vitamin C screening was p=0.3, and after 18 days of supplementation, p=0.03. For Nasal ICAM p=0.5 at Day 0, p=0.4 at Day 4, and p=0.9 at Day 18. For the Histamine samples p=0.9 at Day 0 and p=0.9 at Day 18. The following P-values calculated from the data collected from both studies. The plasma vitamin C screening was p=0.8, and after 18 days of supplementation, p=0.03. The change of vitamin C at the end of this study and the combined data both had a P-value that was calculated to be lower than 0.05, which meant that this change was significant because it was due to the intervention and not chance. For Nasal ICAM samples p=0.7 at Day 0, p=0.7 at Day 4, and p=1 at Day 18. For the Histamine p=0.7 at Day 0 and p=0.9 at Day 18. This study carries various implications although the study data was unable to show much significance. This was the second study to test this, and as more research is done, and the sample size grows, one will be able to observe whether this really is the mechanism through which vitamin C plays a role in immunological functions.
ContributorsKapadia, Chirag Vinay (Author) / Johnston, Carol (Thesis director) / LaBaer, Joshua (Committee member) / School of Molecular Sciences (Contributor) / Barrett, The Honors College (Contributor)
Created2015-12
Description
There are two goals for this honors student project: (1) to determine (using an online survey) what college students do and do not know about cooking and preparing foods and (2) to video record short demonstrations of several cooking skills that college students lack the most based on survey responses. Ultimately, this project hopes to help students develop skills they can use in the kitchen to encourage more cooking at home and less eating out, dietary changes that should lead to more healthful meals and a healthier population. Links to cooking videos: https://youtu.be/ufsVYnfoCQM https://youtu.be/aZCIH33ebZ0
ContributorsKarr, Alexandra Rose (Author) / Johnston, Carol (Thesis director) / Jacobs, Mark (Committee member) / School of Nutrition and Health Promotion (Contributor) / W. P. Carey School of Business (Contributor) / Barrett, The Honors College (Contributor)
Created2016-05
Description
Many individuals are not following healthy lifestyles as evidenced by the high obesity rates and poor physical activity levels. Many do not know how to eat healthy and exercise effectively, especially given busy schedules and no time to cook or go to the gym. However, people do spend a significant amount of time on their mobile device using social media. This outlet can potentially be used to inspire and teach individuals how to cook healthy simple meals, or find motivation to get off the couch for some exercise. In this study, strategies were identified that would increase the comments, likes, and followers of the investigator's Instagrams, which were designed to motivate followers to live a healthier lifestyle. Initially, 462 posts were assessed retrospectively to determine how the number of likes and comments were influenced by hashtags, category of posts (nutrition, fitness, or inspiration), and/or type of app, PicPlayPost, Instaframe, and the updated Instagram. These results were used in a 1-month prospective study to increase likes and followers to the investigator's Instagrams. In the retrospective study, it was determined that hashtags influenced the number of comments and likes across the categories and that the PicPlayPost app increased the likes in all categories. Hence, for the prospective study, the investigator wrote 1 nutrition and 1 fitness post daily for 28 days using a minimum of 15 hashtags per post. In addition, 3 nutrition posts and 3 fitness posts per week used the PicPlayPost app. This posting strategy increased the number of likes per post by 100%, and the number of followers increased from 369 to 1082 in one month. Interestingly, the nutrition posts received 27% more likes than the fitness posts, and the PicPlayPost app increased comments by 134%. In conclusion, the use of hashtags, PicPlayPost, and Instaframe apps increased the likes and comments on social media. These strategies may increase audience's attention on a certain topic and be used to improve individuals' lifestyles.
ContributorsTomasso, Bernice Grace (Author) / Johnston, Carol (Thesis director) / Dixon, Kathy (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor)
Created2014-05
Description
Height is an essential measure for the evaluation of an adult's health, and especially important for the measure of children's health.4 Lasers have been popularly used in many areas such as construction, engineering, government for defense purposes, and for equestrians. Lasers are depended on for their accuracy, reliability, and ease of use.8, 9 It can be reasoned then that lasers should be a reliable way of measuring height, proving to be accurate and easy to use. Currently, stadiometers are the standard way of measuring height. For the study a laser tool was created to measure the volunteers' heights. Volunteers were recruited from a total of four various public sites in different cities. Participants were categorized into three groups, children (ages 2-12), adolescents (13-18), and adults (19+). A total of 128 participants were measured. Results showed a strong positive correlation between measurements of the stadiometer and the laser (figure 3). While there were limitations to this study, results show that a laser may be a validated tool to measure height accurately
ContributorsGarcia-Turner, Vanessa Marie (Author) / Mayol-Kreiser, Sandra (Thesis director) / Johnston, Carol (Committee member) / Barrett, The Honors College (Contributor) / School of Nutrition and Health Promotion (Contributor) / Department of Psychology (Contributor)
Created2014-05
Description
Cuticular hydrocarbons (CHCs) play a crucial role in social insect recognition systems. In this study we investigated mate choice in the red harvester ant, Pogonomyrmex barbatus. In Phoenix, this species has two lineages, J1 and J2, which look identical, but are genetically isolated. In the genetic caste determination (GCD) system workers and queens are determined by their genotype (i.e., workers develop from interlineage crosses, queens from intralineage crosses). As such, J1 and J2 lineages are dependent on each other in order for colonies to produce both workers and reproductive queens. Given their genetic isolation and interdependence, we hypothesized that the CHCs of alate males and queens are affected by lineage, and that differences in the CHC profile are used for mate recognition. We tested these hypotheses by analyzing the lineage distributions of actively mating pairs (n=65), and compared them with the overall distribution of male and female sexuals (n=180). We additionally analyzed the five most abundant CHC compounds for 20 of the actively mating P. barbatus alate male and queen pairs to determine how variable the two lineages are between each sex. We found that mating pair distributions did not significantly differ from those expected under a random mating system (�2= 1.4349, P= 0.6973), however, CHC profiles did differ between J1 and J2 lineages and sexes for the five most abundant CHC compounds. Our results show that random mating is taking place in this population, however given the differences observed in CHC profiles, mate recognition could be taking place.
ContributorsTula Del Moral Testai, Pedro Rafael (Co-author) / Cash, Elizabeth (Co-author) / Gadau, Juergen (Thesis director) / Liebig, Juergen (Committee member) / Barrett, The Honors College (Contributor) / School of International Letters and Cultures (Contributor) / School of Life Sciences (Contributor)
Created2014-05