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Description
The body is capable of regulating hunger in several ways. Some of these hunger regulation methods are innate, such as genetics, and some, such as the responses to stress and to the smell of food, are innate but can be affected by body conditions such as BMI and physical activity. Further, some hunger regulation methods stem from learned behaviors originating from cultural pressures or parenting styles. These latter regulation methods for hunger can be grouped into the categories: emotion, environment, and physical. The factors that regulate hunger can also influence the incidence of disordered eating, such as eating in the absence of hunger (EAH). Eating in the absence of hunger can occur in one of two scenarios, continuous EAH or beginning EAH. College students are at a particularly high risk for EAH and weight gain due to stress, social pressures, and the constant availability of energy dense and nutrient poor food options. The purpose of this study is to validate a modified EAH-C survey in college students and to discover which of the three latent factors (emotion, environment, physical) best predicts continual and beginning EAH. To do so, a modified EAH-C survey, with additional demographic components, was administered to students at a major southwest university. This survey contained two questions, one each for continuing and beginning EAH, regarding 14 factors related to emotional, physical, or environmental reasons that may trigger EAH. The results from this study revealed that the continual and beginning EAH surveys displayed good internal consistency reliability. We found that for beginning and continuing EAH, although emotion is the strongest predictor of EAH, all three latent factors are significant predictors of EAH. In addition, we found that environmental factors had the greatest influence on an individual's likelihood to continue to eat in the absence of hunger. Due to statistical abnormalities and differing numbers of factors in each category, we were unable to determine which of the three factors exerted the greatest influence on an individual's likelihood to begin eating in the absence of hunger. These results can be utilized to develop educational tools aimed at reducing EAH in college students, and ultimately reducing the likelihood for unhealthy weight gain and health complications related to obesity.
ContributorsGoett, Taylor (Author) / Johnston, Carol (Thesis advisor) / Lee, Chong (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2013
Description
ABSTRACT The hormone leptin is an important regulator of body weight and energy balance, while nitric oxide (NO) produced in the blood vessels is beneficial for preventing disease-induced impaired vasodilation and hypertension. Elevations in the free radical superoxide can result in impaired vasodilation through scavenging of NO. Omega 3 is a polyunsaturated fatty acid that is beneficial at reducing body weight and in lowering many cardiovascular risk factors like atherosclerosis. The present study was designed to examine the change in plasma concentrations of leptin, nitric oxide, and the antioxidant superoxide dismutase in addition to examining the association between leptin and NO in healthy normal weight adult female subjects before and following omega 3 intakes. Participants were randomly assigned to either a fish oil group (600 mg per day) or a control group (1000 mg of coconut oil per day) for 8 weeks. Results showed no significant difference in the percent change of leptin over the 8 week supplementation period for either group (15.3±31.9 for fish oil group, 7.83±27 for control group; p=0.763). The percent change in NO was similarly not significantly altered in either group (-1.97±22 decline in fish oil group, 11.8±53.9 in control group; p=0.960). Likewise, the percent change in superoxide dismutase for each group was not significant following 8 weeks of supplementation (fish oil group: 11.94±20.94; control group: 11.8±53.9; p=0.362). The Pearson correlation co-efficient comparing the percent change of both leptin and NO was r2= -0.251 demonstrating a mildly negative, albeit insignificant, relationship between these factors. Together, these findings suggest that daily supplementation with 600 mg omega 3 in healthy females is not beneficial for improving these cardiovascular risk markers. Future studies in this area should include male subjects as well as overweight subjects with larger doses of fish oil that are equivalent to three or more servings per week. The importance of gender cannot be underestimated since estrogen has protective effects in the vasculature of females that may have masked any further protective effects of the fish oil. In addition, overweight individuals are often leptin-resistant and develop impaired vasodilation resulting from superoxide-mediated scavenging of nitric oxide. Therefore, the reported antioxidant and weight loss properties of omega 3 supplementation may greatly benefit overweight individuals.
ContributorsAlanbagy, Samer (Author) / Sweazea, Karen (Thesis advisor) / Johnston, Carol (Committee member) / Shepard, Christina (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2014
Description
ABSTRACT
Asthma is a high-stress, chronic medical condition; 1 in 12 adults in the United States combat the bronchoconstriction from asthma. However, there are very few strong studies indicating any alternative therapy for asthmatics, particularly following a cold incidence. Vitamin C has been proven to be effective for other high-stress populations, but the asthmatic population has not yet been trialed. This study examined the effectiveness of vitamin C supplementation during the cold season on cold incidence and asthmatic symptoms. Asthmatics, otherwise-healthy, who were non-smokers and non-athletes between the ages of 18 and 55 with low plasma vitamin C concentrations were separated by anthropometrics and vitamin C status into two groups: either vitamin C (500 mg vitamin C capsule consumed twice per day) or control (placebo capsule consumed twice per day). Subjects were instructed to complete the Wisconsin Upper Respiratory Symptom Survey-21 and a short asthma symptoms questionnaire daily along with a shortened vitamin C Food Frequency Questionnaire and physical activity questionnaire weekly for eight weeks. Blood samples were drawn at Week 0 (baseline), Week 4, and Week 8. Compliance was monitored through a calendar check sheet. The vitamin C levels of both groups increased from Week 0 to Week 4, but decreased in the vitamin C group at Week 8. The vitamin C group had a 19% decrease in plasma histamine while the control group had a 53% increase in plasma histamine at the end of the trial, but this was not statistically significant (p>0.05). Total symptoms recorded from WURSS-21 were 129.3±120.7 for the vitamin C and 271.0±293.9, but the difference was not statistically significant (p=0.724). Total asthma symptoms also slightly varied between the groups, but again was not statistically significant (p=0.154). These results were hindered by the low number of subjects recruited. Continued research in this study approach is necessary to definitively reject or accept the potential role of vitamin C in asthma and cold care.
Asthma is a high-stress, chronic medical condition; 1 in 12 adults in the United States combat the bronchoconstriction from asthma. However, there are very few strong studies indicating any alternative therapy for asthmatics, particularly following a cold incidence. Vitamin C has been proven to be effective for other high-stress populations, but the asthmatic population has not yet been trialed. This study examined the effectiveness of vitamin C supplementation during the cold season on cold incidence and asthmatic symptoms. Asthmatics, otherwise-healthy, who were non-smokers and non-athletes between the ages of 18 and 55 with low plasma vitamin C concentrations were separated by anthropometrics and vitamin C status into two groups: either vitamin C (500 mg vitamin C capsule consumed twice per day) or control (placebo capsule consumed twice per day). Subjects were instructed to complete the Wisconsin Upper Respiratory Symptom Survey-21 and a short asthma symptoms questionnaire daily along with a shortened vitamin C Food Frequency Questionnaire and physical activity questionnaire weekly for eight weeks. Blood samples were drawn at Week 0 (baseline), Week 4, and Week 8. Compliance was monitored through a calendar check sheet. The vitamin C levels of both groups increased from Week 0 to Week 4, but decreased in the vitamin C group at Week 8. The vitamin C group had a 19% decrease in plasma histamine while the control group had a 53% increase in plasma histamine at the end of the trial, but this was not statistically significant (p>0.05). Total symptoms recorded from WURSS-21 were 129.3±120.7 for the vitamin C and 271.0±293.9, but the difference was not statistically significant (p=0.724). Total asthma symptoms also slightly varied between the groups, but again was not statistically significant (p=0.154). These results were hindered by the low number of subjects recruited. Continued research in this study approach is necessary to definitively reject or accept the potential role of vitamin C in asthma and cold care.
ContributorsEarhart, Kathryn Michelle (Author) / Johnston, Carol (Thesis advisor) / Sweazea, Karen (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2015
Description
Despite recent strides for awareness, treatment, and control of hypertension, prevalence remains high with estimates suggesting one third of Americans have hypertension. The hypotensive effects of potassium and magnesium have been known and administered in a clinical setting for nearly a century. The purpose of this study was to examine the effectiveness of taking a potassium/magnesium supplement to help reduce blood pressure in individuals with mildly-moderately elevated blood pressure. In this randomized, controlled crossover trial, potassium and magnesium supplementation was explored among healthy adults with mildly elevated blood pressure in Phoenix, Arizona. Subjects (n = 12) were randomly assigned to ingest either the treatment chewy bar (217 mg potassium/day; 70.8 mg magnesium/day) or a placebo chewy bar for four weeks. For the subsequent four weeks, subjects ingested the other corresponding chewy bar. Systolic (SBP), diastolic (DBP), and average blood pressure values were not significantly different between the two groups (p = 0.645, p = 0.464 and p = 0.939, respectively). Baseline mean blood pressure was 121.0/75.7 mm Hg. The 12 subjects (8 females, 4 males) had a mean age of 29.3 years old and a mean BMI of 26.2. After four weeks, the treatment group had a slightly higher SBP (118.3 ± 13.3 mm Hg) than the control group (116.5 ± 17.8 mm Hg); however, DBP was lower in the treatment group (71.7 ± 12.4 mm Hg) than the control group (73.0 ± 10.0 mm Hg). In conclusion, daily supplementation of potassium and magnesium (217.2 mg/day and 70.8 mg/day, respectively) did not significantly lower blood pressure in adults with mildly-moderately elevated blood pressure.
ContributorsPawloski, Jason (Author) / Johnston, Carol (Thesis advisor) / Vega-Lopez, Sonia (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2015
Description
To date, there have not been any studies in a human population that explore the potential of vinegar ingestion in reducing visceral fat, a common yet serious metabolic disease risk factor. However, previous research in animal models exhibit promising findings, showing that vinegar is effective at reducing visceral fat. This is thought to be due to the activation of AMPK (adenosine monophosphate protein kinase) by acetic acid, the active ingredient in vinegar. The purpose of this study was to identify if this potentially groundbreaking relationship exists in human subjects. Healthy, nonsmoking, sedentary adults between the ages 18-45 y and a waist circumference measurement greater than or equal to 33 inches for women and 38 inches for men were recruited for this study. Twenty-three participants completed this 8-week, parallel arm, randomized control trial that tested the efficacy of red wine vinegar consumption (2 tablespoons red wine vinegar, twice per day, before a meal; providing 3.6 g acetic acid) against a placebo (1 apple cider vinegar pill, twice per day, before a meal; providing 0.0225 g acetic acid) for 8 weeks. Participants were randomized into either the vinegar (VIN) or control (CON) group after being stratified by age, gender, waist circumference, and weight. Results found that the VIN group experienced a 2% decrease in visceral fat (cm3, quantified by a DXA scan), but this change did not differ significantly from that of the CON group (p=0.256). The VIN group also experienced a slight decrease in insulin compared to the CON group, but this change was not significantly different than the control change (p=0.125). However, the change in HOMA-IR trended downward in the VIN group (-16%) as compared to the CON group (+9%) (p=0.079) with a large effect size, 0.153. Other parameters did not show statistically significant results between the groups. Further research is indicated in order to examine the potential of vinegar to reduce visceral fat.
ContributorsBaker, Olivia (Author) / Johnston, Carol (Thesis advisor) / Mayol-Kreiser, Sandra (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2018
Description
Epidemiological studies have identified obesity as a risk factor for numerous chronic diseases such as adult onset diabetes, hypertension, and hypercholesterolemia. In both humans and laboratory animals, high-fat diets have been shown to cause obesity. Increases in dietary fat lead to increased energy consumption and, consequently, significant increases in body fat content. CD36 has been implicated in fat perception, preference, and increased consumption, but it is yet to be tested using a behavior paradigm. To study the effect of CD36 on fat taste transmission and fat consumption, four CD36 knockout (experimental) mice and four Black 6 wildtype (control) mice underwent 20 days of fat preference and perception testing. Both groups of mice were exposed to foods with progressively increasing fat content (10%, 12.5%, 15% 17.5%, 20%, 45%) in order to assess the effect of CD36 on fat preference. Afterward, the mice were subjected to an aversive conditioning protocol designed to test the effect of CD36 on fat taste perception; development of a conditioned taste aversion was indicative of ability to taste fat. Especially, knockout mice exhibited diminished preference for and reduced consumption of fat during preference testing and were unable to identify fat taste as the conditioned stimulus during aversive conditioning. A repeated measures ANOVA with Bonferroni correction revealed a significant main effect of group on fat consumption, energy intake, and weight. Linear regression revealed CD36 status to account for a majority of observed variance in fat consumption across both phases of the experiment. These results implicate CD36 in fat taste perception and preference and add to the growing body of evidence suggesting fat as a primary taste.
ContributorsJasbi, Paniz (Author) / Johnston, Carol (Thesis advisor) / Lespron, Christy (Committee member) / Wadhera, Devina (Committee member) / Arizona State University (Publisher)
Created2018
Description
This study investigates the relation between credit supply competition among banks and their clients’ conditional accounting conservatism (i.e., asymmetric timely loss recognition). The Interstate Banking and Branching Efficiency Act (IBBEA) of 1994 permits banks and bank holding companies to expand their business across state lines, introducing a positive shock to credit supply competition in the banking industry. The increase in credit supply competition weakens banks’ bargaining power in the negotiation process, which in turn may weaken their ability to demand conservative financial reporting from borrowers. Consistent with this prediction, results show that firms report less conservatively after the IBBEA is passed in their headquartered states. The effect of the IBBEA on conditional conservatism is particularly stronger for firms in states with a greater increase in competition among banks, firms whose operations are more concentrated in their headquarter states, firms with greater financial constraints, and firms subject to less external monitoring. Robustness tests confirm that the observed decline in conditional conservatism is causally related to the passage of IBBEA. Overall, this study highlights the impact of credit supply competition on financial reporting practices.
ContributorsHuang, Wei (Author) / Li, Yinghua (Thesis advisor) / Huang, Xiaochuan (Committee member) / Kaplan, Steve (Committee member) / Arizona State University (Publisher)
Created2018
Description
ABSTRACT
Many natural interventions have been effective at lowering postprandial glucose concentrations (PPG) in research trials and, theoretically, should have favorable effects on the prevention and management of T2DM. Natural interventions include vinegar, nuts and exercise. Green tea has been demonstrated to also possessing antiglycemic effects. Thus, green tea, and its most abundant catechin EGCG, are being consumed for its potential health benefits in cancer prevention and in its inhibitory effects on α-amylase. Many studies have found EGCG to inhibit α-amylase an enzyme needed in the breakdown of carbohydrates (CHO). Other studies have looked at EGCG and its potential for lowering PPG concentrations due to its inhibitory effects on α-amylase in both mice and humans. Yet there is no research on Matcha tea specifically. Matcha tea is green tea in powder form; hence, it is consumed in its entirety unlike traditional teas which are steeped in bags. The purpose of this study was to determine whether Macha tea impacts PPG concentrations in healthy adults. Twelve subjects completed this randomized controlled, single blinded, crossover study. On three separate occasions the twelve subjects consumed a bagel and jam with either water, Lipton green tea, or Macha tea. Fasting blood glucose was taken upon their arrival. Once the tea or water and bagel with jam were consumed PPG concentrations were measured every 30 minutes until 120 minutes were reached. Results showed no statistically significant effects on PPG concentrations in either test groups (p=.960). However, this study did not measure EGCG levels in the tea provided. Therefore, further research should be done with known EGCG amounts to see its effects on PPG concentrations to fully rule out its potential.
Many natural interventions have been effective at lowering postprandial glucose concentrations (PPG) in research trials and, theoretically, should have favorable effects on the prevention and management of T2DM. Natural interventions include vinegar, nuts and exercise. Green tea has been demonstrated to also possessing antiglycemic effects. Thus, green tea, and its most abundant catechin EGCG, are being consumed for its potential health benefits in cancer prevention and in its inhibitory effects on α-amylase. Many studies have found EGCG to inhibit α-amylase an enzyme needed in the breakdown of carbohydrates (CHO). Other studies have looked at EGCG and its potential for lowering PPG concentrations due to its inhibitory effects on α-amylase in both mice and humans. Yet there is no research on Matcha tea specifically. Matcha tea is green tea in powder form; hence, it is consumed in its entirety unlike traditional teas which are steeped in bags. The purpose of this study was to determine whether Macha tea impacts PPG concentrations in healthy adults. Twelve subjects completed this randomized controlled, single blinded, crossover study. On three separate occasions the twelve subjects consumed a bagel and jam with either water, Lipton green tea, or Macha tea. Fasting blood glucose was taken upon their arrival. Once the tea or water and bagel with jam were consumed PPG concentrations were measured every 30 minutes until 120 minutes were reached. Results showed no statistically significant effects on PPG concentrations in either test groups (p=.960). However, this study did not measure EGCG levels in the tea provided. Therefore, further research should be done with known EGCG amounts to see its effects on PPG concentrations to fully rule out its potential.
ContributorsRomash, Roni (Author) / Johnston, Carol (Thesis advisor) / Dixon, Kathleen (Committee member) / Lespron, Christy (Committee member) / Arizona State University (Publisher)
Created2018
Description摘要
当前中国农村集体经济呈现出后劲不足、区域失衡等问题。在此背景下，如何破解集体经济发展困境、实现其从梯度到均衡的演进成为学术领域关注的热点。本文梳理总结了国内外集体经济的相关研究成果，阐述了主要涉及的基础概念、理论和方法模型；以2008~2015年无锡市滨湖区92个村为研究样本，分析了该区域集体经济的发展现状和演变进程；构建面板回归模型，探索了该区域集体经济发展的驱动因素与分布不平衡性；并从空间关联视角切入，探索了驱动因素的溢出效应；最后基于研究结果提出对策建议。主要结论如下：
（1）2008~2015年，92个村的村级集体经济发展整体呈现上升趋势，但地区间的贫富差距明显；2008年、2011年和2015年92个村按村级集体经济总收入可划分为高、中、低3类，并且在不同时段，各等级间的村级集体单位会相互迁移；集体经济收入呈现明显的右偏分布，尖峰厚尾的特征显著。随着时间的推移，集体经济发展出现了“双峰趋同”的现象。
（2）普通面板回归显示，物质资本、经济工作能力、科技进步对于村级集体经济发展有正向的依次减弱的影响，人口数量的影响为负；面板分位数回归显示，随着分位数水平的提高，物质资本系数先上升、后下降再上升；经济工作能力系数逐渐减小；人口规模系数先下降后上升；科技进步系数波动上升。
（3）空间计量结果显示，各变量对于村级集体经济发展具有一定的溢出效应，其中，物质资本的溢出效应为正（不显著），经济工作能力的溢出效应为正（显著），人口因素的溢出效应为负（不显著），科技进步的溢出效应为正（显著）。
本文的创新之处在于使用较难获取的2008-2015年92个村面板数据进行回归，相比于截面数据，更准确地测度了各要素对集体经济的真实影响；将空间关联因素纳入研究视域，探究了村级集体经济驱动因素的空间溢出效应。
当前中国农村集体经济呈现出后劲不足、区域失衡等问题。在此背景下，如何破解集体经济发展困境、实现其从梯度到均衡的演进成为学术领域关注的热点。本文梳理总结了国内外集体经济的相关研究成果，阐述了主要涉及的基础概念、理论和方法模型；以2008~2015年无锡市滨湖区92个村为研究样本，分析了该区域集体经济的发展现状和演变进程；构建面板回归模型，探索了该区域集体经济发展的驱动因素与分布不平衡性；并从空间关联视角切入，探索了驱动因素的溢出效应；最后基于研究结果提出对策建议。主要结论如下：
（1）2008~2015年，92个村的村级集体经济发展整体呈现上升趋势，但地区间的贫富差距明显；2008年、2011年和2015年92个村按村级集体经济总收入可划分为高、中、低3类，并且在不同时段，各等级间的村级集体单位会相互迁移；集体经济收入呈现明显的右偏分布，尖峰厚尾的特征显著。随着时间的推移，集体经济发展出现了“双峰趋同”的现象。
（2）普通面板回归显示，物质资本、经济工作能力、科技进步对于村级集体经济发展有正向的依次减弱的影响，人口数量的影响为负；面板分位数回归显示，随着分位数水平的提高，物质资本系数先上升、后下降再上升；经济工作能力系数逐渐减小；人口规模系数先下降后上升；科技进步系数波动上升。
（3）空间计量结果显示，各变量对于村级集体经济发展具有一定的溢出效应，其中，物质资本的溢出效应为正（不显著），经济工作能力的溢出效应为正（显著），人口因素的溢出效应为负（不显著），科技进步的溢出效应为正（显著）。
本文的创新之处在于使用较难获取的2008-2015年92个村面板数据进行回归，相比于截面数据，更准确地测度了各要素对集体经济的真实影响；将空间关联因素纳入研究视域，探究了村级集体经济驱动因素的空间溢出效应。
ContributorsJin, Liang (Author) / Gu, Bin (Thesis advisor) / Zhang, Anmin (Thesis advisor) / Zhu, Qigui (Committee member) / Arizona State University (Publisher)
Created2019
Description当前，上市公司的盈余管理问题已是我国资本市场中普遍存在的突出问题。一般来说，一些企业为了满足资本市场对于上市、增发等条件的要求,以及为有效推动企业的并购、重组等行为的顺利实现,甚至为了谋求公司管理层的个别利益,往往运用盈余管理等举措实施公司财报及关键指标的粉饰修正，让不知情的股民蒙受一定的损失。普遍分析显示，我国股市中民营企业比其他企业遭遇的问题和压力更多、更大、更突出,因此民营企业从客观上来说拥有更强的盈余管理动机。而从当前我国资本市场的实际情况来看，我国相关专家学者对盈余管理的系统性深入研究，一般都瞄准了上市企业群体或持续亏损企业，对盈余管理的研究不系统、不全面、不深入，这将对我国进一步提升盈余管理监管水平构成一定不利影响。当前，由于我国民企在自身管理及发展动力方面的特殊性,我国民企的管理、盈余管理特点和国外上市公司还存在着很大的不同,进一步深入研究我国民企上市公司自身管理方面的突出特点，以及其对企业盈余管理等方面的深层次影响,有助于监管层对症下药，更有针对性地研究出台全新的监管措施,进一步提升管理水平。这还可以为公司发展的决策层及相关会计信息使用人员提供一定的决策参考, 因此其拥有十分重要的意义。
本文首先认真总结分析了有关上市企业治理结构和盈余管理等方面的历史文献资料，依托当前资本市场上普遍运用的委托代理、内部人控制和契约等理论，系统研究了我国民企上市公司在自身治理结构方面的突出特征以及其对盈余管理方面所构成影响的深层次原理。在此基础上，本文通过2015-2017年我国上市企业数据，基于截面Jones模型对民营企业和非民营企业盈余管理程度进行测算和比较分析，发现民营企业盈余管理程度更高；从四个层面系统研究民企公司自身的治理结构突出特点,设立回归模型论证了民营企业独特的公司治理结构特征对盈余管理程度确实会产生影响；最后,本文进一步利用修正的费尔萨姆一奥尔森估价模型对民营上市公司盈余管理有公司价值的关系进行了验证，发现两者具有显著相关性。
本文首先认真总结分析了有关上市企业治理结构和盈余管理等方面的历史文献资料，依托当前资本市场上普遍运用的委托代理、内部人控制和契约等理论，系统研究了我国民企上市公司在自身治理结构方面的突出特征以及其对盈余管理方面所构成影响的深层次原理。在此基础上，本文通过2015-2017年我国上市企业数据，基于截面Jones模型对民营企业和非民营企业盈余管理程度进行测算和比较分析，发现民营企业盈余管理程度更高；从四个层面系统研究民企公司自身的治理结构突出特点,设立回归模型论证了民营企业独特的公司治理结构特征对盈余管理程度确实会产生影响；最后,本文进一步利用修正的费尔萨姆一奥尔森估价模型对民营上市公司盈余管理有公司价值的关系进行了验证，发现两者具有显著相关性。
ContributorsChen, Hui (Author) / Shen, Wei (Thesis advisor) / Chang, Chun (Thesis advisor) / Huang, Xiaochuan (Committee member) / Arizona State University (Publisher)
Created2019