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- Genre: Doctoral Dissertation
Description
Obesity in Hispanic youth has reached alarmingly high levels, increasing the risk of type 2 diabetes, hyperlipidemia, hypertension, and cardiovascular disease. In Mexican American children ages 6-11 years, 41.7% are overweight and obese, 24.7% are obese and 19.6% have a Body Mass Index (BMI) greater than the 97th percentile. While personal, behavioral, and environmental factors contribute to these high rates, emerging literature suggests acculturation, self-efficacy and social support are key influences. The one-group, pre- and post-test, quasi-experimental design used a community-based participatory research (CBPR) method to test the feasibility, acceptability, and preliminary efficacy of the 8-week intervention. Social Cognitive Theory (SCT) was used to guide the design. Measurements included an analysis of recruitment, retention, participant satisfaction, observation of intervention sessions, paired t-tests, effect sizes, and bivariate correlations between study variables (acculturation, nutrition and physical activity [PA] knowledge, attitude and behaviors, perceived confidence and social support) and outcome variables (BMI z-score, waist circumference and BP percentile) Findings showed the SSLN program was feasible and acceptable. Participants (n = 16) reported that the curriculum was fun and they learned about nutrition and PA. The retention rate was 94%. The preliminary effects on adolescent nutrition and PA behaviors showed mixed results with small-to-medium effect sizes for nutrition knowledge and attitude, PA and sedentary behavior. Correlation analysis among acculturation and study variables was not significant. Positive associations were found between perceived confidence in eating and nutrition attitude (r = .61, p < .05) and nutrition behavior (r = .62, p < .05), perceived confidence in exercise and nutrition behavior (r = .66, p < .05), social support from family for exercise and PA behavior (r = .67, p < .01) and social support from friends for exercise and PA behavior (r = .56, p < .05). These findings suggest a culturally specific healthy eating and activity program for adolescents was feasible and acceptable and warrants further investigation, since it may fill a gap in existing obesity programs designed for Hispanic youth. The positive correlations suggest further testing of the theoretical model.
ContributorsStevens, Carol (Author) / Gance-Cleveland, Bonnie (Thesis advisor) / Komnenich, Pauline (Committee member) / Shaibi, Gabriel (Committee member) / Arcoleo, Kimberly (Committee member) / Arizona State University (Publisher)
Created2011
Description
Cardiovascular disease (CVD) is the number one cause of death in the United States and type 2 diabetes (T2D) and obesity lead to cardiovascular disease. Obese adults are more susceptible to CVD compared to their non-obese counterparts. Exercise training leads to large reductions in the risk of CVD and T2D. Recent evidence suggests high-intensity interval training (HIT) may yield similar or superior benefits in a shorter amount of time compared to traditional continuous exercise training. The purpose of this study was to compare the effects of HIT to continuous (CONT) exercise training for the improvement of endothelial function, glucose control, and visceral adipose tissue. Seventeen obese men (N=9) and women (N=8) were randomized to eight weeks of either HIT (N=9, age=34 years, BMI=37.6 kg/m2) or CONT (N=8, age=34 years, BMI=34.6 kg/m2) exercise 3 days/week for 8 weeks. Endothelial function was assessed via flow-mediated dilation (FMD), glucose control was assessed via continuous glucose monitoring (CGM), and visceral adipose tissue and body composition was measured with an iDXA. Incremental exercise testing was performed at baseline, 4 weeks, and 8 weeks. There were no changes in weight, fat mass, or visceral adipose tissue measured by the iDXA, but there was a significant reduction in body fat that did not differ by group (46±6.3 to 45.4±6.6%, P=0.025). HIT led to a significantly greater improvement in FMD compared to CONT exercise (HIT: 5.1 to 9.0%; CONT: 5.0 to 2.6%, P=0.006). Average 24-hour glucose was not improved over the whole group and there were no group x time interactions for CGM data (HIT: 103.9 to 98.2 mg/dl; CONT: 99.9 to 100.2 mg/dl, P>0.05). When statistical analysis included only the subjects who started with an average glucose at baseline > 100 mg/dl, there was a significant improvement in glucose control overall, but no group x time interaction (107.8 to 94.2 mg/dl, P=0.027). Eight weeks of HIT led to superior improvements in endothelial function and similar improvements in glucose control in obese subjects at risk for T2D and CVD. HIT was shown to have comparable or superior health benefits in this obese sample with a 36% lower total exercise time commitment.
ContributorsSawyer, Brandon J (Author) / Gaesser, Glenn A (Thesis advisor) / Shaibi, Gabriel (Committee member) / Lee, Chong (Committee member) / Swan, Pamela (Committee member) / Buman, Matthew (Committee member) / Arizona State University (Publisher)
Created2013
Description
Purpose: The purpose of this study was to examine the acute effects of two novel intermittent exercise prescriptions on glucose regulation and ambulatory blood pressure. Methods: Ten subjects (5 men and 5 women, ages 31.5 ± 5.42 yr, height 170.38 ± 9.69 cm and weight 88.59 ± 18.91 kg) participated in this four-treatment crossover trial. All subjects participated in four trials, each taking place over three days. On the evening of the first day, subjects were fitted with a continuous glucose monitor (CGM). On the second day, subjects were fitted with an ambulatory blood pressure monitor (ABP) and underwent one of the following four conditions in a randomized order: 1) 30-min: 30 minutes of continuous exercise at 60 - 70% VO2peak; 2) Mod 2-min: twenty-one 2-min bouts of walking at 3 mph performed once every 20 minutes; 3) HI 2-min: eight 2-min bouts of walking at maximal incline performed once every hour; 4) Control: a no exercise control condition. On the morning of the third day, the CGM and ABP devices were removed. All meals were standardized during the study visits. Linear mixed models were used to compare mean differences in glucose and blood pressure regulation between the four trials. Results: Glucose concentrations were significantly lower following the 30-min (91.1 ± 14.9 mg/dl), Mod 2-min (93.7 ± 19.8 mg/dl) and HI 2-min (96.1 ± 16.4 mg/dl) trials as compared to the Control (101.1 ± 20 mg/dl) (P < 0.001 for all three comparisons). The 30-min trial was superior to the Mod 2-min, which was superior to the HI 2-min trial in lowering blood glucose levels (P < 0.001 and P = 0.003 respectively). Only the 30-min trial was effective in lowering systolic ABP (124 ± 12 mmHg) as compared to the Control trial (127 ± 14 mmHg; P < 0.001) for up to 11 hours post exercise. Conclusion: Performing frequent short (i.e., 2 minutes) bouts of moderate or high intensity exercise may be a viable alternative to traditional continuous exercise in improving glucose regulation. However, 2-min bouts of exercise are not effective in reducing ambulatory blood pressure in healthy adults.
ContributorsBhammar, Dharini Mukeshkumar (Author) / Gaesser, Glenn A (Thesis advisor) / Shaibi, Gabriel (Committee member) / Buman, Matthew (Committee member) / Swan, Pamela (Committee member) / Lee, Chong (Committee member) / Arizona State University (Publisher)
Created2013
Description
Background: Evidence about the purported hypoglycemic and hypolipidemic effects of nopales (prickly pear cactus pads) is limited. Objective: To evaluate the efficacy of nopales for improving cardiometabolic risk factors and oxidative stress, compared to control, in adults with hypercholesterolemia. Design: In a randomized crossover trial, participants were assigned to a 2-wk intervention with 2 cups/day of nopales or cucumbers (control), with a 2 to 3-wk washout period. The study included 16 adults (5 male; 46±14 y; BMI = 31.4±5.7 kg/m2) with moderate hypercholesterolemia (low density lipoprotein cholesterol [LDL-c] = 137±21 mg/dL), but otherwise healthy. Main outcomes measured included: dietary intake (energy, macronutrients and micronutrients), cardiometabolic risk markers (total cholesterol, LDL-c, high density lipoprotein cholesterol [HDL-c], triglycerides, cholesterol distribution in LDL and HDL subfractions, glucose, insulin, homeostasis model assessment, and C-reactive protein), and oxidative stress markers (vitamin C, total antioxidant capacity, oxidized LDL, and LDL susceptibility to oxidation). Effects of treatment, time, or interactions were assessed using repeated measures ANOVA. Results: There was no significant treatment-by-time effect for any dietary composition data, lipid profile, cardiometabolic outcomes, or oxidative stress markers. A significant time effect was observed for energy, which was decreased in both treatments (cucumber, -8.3%; nopales, -10.1%; pTime=0.026) mostly due to lower mono and polyunsaturated fatty acids intake (pTime=0.023 and pTime=0.003, respectively). Both treatments significantly increased triglyceride concentrations (cucumber, 14.8%; nopales, 15.2%; pTime=0.020). Despite the lack of significant treatment-by-time effects, great individual response variability was observed for all outcomes. After the cucumber and nopales phases, a decrease in LDL-c was observed in 44% and 63% of the participants respectively. On average LDL-c was decreased by 2.0 mg/dL (-1.4%) after the cucumber phase and 3.9 mg/dL (-2.9%) after the nopales phase (pTime=0.176). Pro-atherogenic changes in HDL subfractions were observed in both interventions over time, by decreasing the proportion of HDL-c in large HDL (cucumber, -5.1%; nopales, -5.9%; pTime=0.021) and increasing the proportion in small HDL (cucumber, 4.1%; nopales, 7.9%; pTime=0.002). Conclusions: These data do not support the purported benefits of nopales at doses of 2 cups/day for 2-wk on markers of lipoprotein profile, cardiometabolic risk, and oxidative stress in hypercholesterolemic adults.
ContributorsPereira Pignotti, Giselle Adriana (Author) / Vega-Lopez, Sonia (Thesis advisor) / Gaesser, Glenn (Committee member) / Keller, Colleen (Committee member) / Shaibi, Gabriel (Committee member) / Sweazea, Karen (Committee member) / Arizona State University (Publisher)
Created2013
Description
The Chinese Construction Industry has grown to be one of the largest construction markets in the world within the last 10 years. The size of the Chinese Construction Industry is on par with many developed nations, despite it being a developing country. Despite its rapid growth, the productivity and profitability of the Chinese Construction Industry is low compared to similar sized construction industries (United States, United Kingdom, etc.). In addition to the low efficiency of the Chinese Construction Industry, there is minimal documentation available showing the performance of the Chinese Construction Industry (projects completed on time, on budget, and customer satisfaction ratings).
The purpose of this research is to investigate potential solutions that could address the poor efficiency and performance of the Chinese Construction Industry. This research is divided into three phases; first, a literature review to identify countries that have similar construction industries to the Chinese Construction Industry. The second phase is to compare the risks and identify solutions that are proposed to increase the performance of similar construction industries and the Chinese Construction Industry. The third phase is to create a survey from the literature-based information to validate the concepts with the Chinese Construction Industry professionals and stakeholders.
The purpose of this research is to investigate potential solutions that could address the poor efficiency and performance of the Chinese Construction Industry. This research is divided into three phases; first, a literature review to identify countries that have similar construction industries to the Chinese Construction Industry. The second phase is to compare the risks and identify solutions that are proposed to increase the performance of similar construction industries and the Chinese Construction Industry. The third phase is to create a survey from the literature-based information to validate the concepts with the Chinese Construction Industry professionals and stakeholders.
ContributorsChen, Yutian (Author) / Chong, Oswald (Thesis advisor) / Kashiwagi, Dean T. (Committee member) / Badger, Willliam (Committee member) / Arizona State University (Publisher)
Created2020
Description
The consequences of failures from large-diameter water pipelines can be severe. Results can include significant property damage, damage to adjacent infrastructure such as roads and bridges resulting in transportation delays or shutdowns, adjacent structural damage to buildings resulting in loss of business, service disruption to a significant number of customers, loss of water, costly emergency repairs, and even loss of life. The American Water Works Association’s (AWWA) 2020 “State of the Water Industry” report states the top issue facing the water industry since 2016 is aging infrastructure, with the second being financing for improvements. The industry must find innovative ways to extend asset life and reduce maintenance expenditures. While are many different assets comprise the drinking water industry, pipelines are a major component and often neglected because they are typically buried. Reliability Centered Maintenance (RCM) is a process used to determine the most effective maintenance strategy for an asset, with the ultimate goal being to establish the required function of the asset with the required reliability at the lowest operations and maintenance costs. The RCM philosophy considers Preventive Maintenance, Predictive Maintenance, Condition Based Monitoring, Reactive Maintenance, and Proactive Maintenance techniques in an integrated manner to increase the probability an asset will perform its designed function throughout its design life with minimal maintenance. In addition to determining maintenance tasks, the timely performance of those tasks is crucial. If performed too late an asset may fail; if performed too early, resources that may be used better elsewhere are expended. Utility agencies can save time and money by using RCM analysis for their drinking water infrastructure. This dissertation reviews industries using RCM, discusses the benefits of an RCM analysis, and goes through a case study of an RCM at a large aqueduct in the United States. The dissertation further discusses the consequence of failure of large diameter water pipelines and proposes a regression model to help agencies determine the optimum time to perform maintenance tasks on large diameter prestressed concrete pipelines using RCM analysis.
ContributorsGeisbush, James R (Author) / Ariaratnam, Samuel T (Thesis advisor) / Grau, David (Committee member) / Chong, Oswald (Committee member) / Arizona State University (Publisher)
Created2024
Description
The United States building sector was the most significant carbon emission contributor (over 40%). The United States government is trying to decrease carbon emissions by enacting policies, but emissions increased by approximately 7 percent in the U.S. between 1990 and 2013. To reduce emissions, investigating the factors affecting carbon emissions should be a priority. Therefore, in this dissertation, this research examine the relationship between carbon emissions and the factors affecting them from macro and micro perspectives. From a macroscopic perspective, the relationship between carbon dioxide, energy resource consumption, energy prices, GDP (gross domestic product), waste generation, and recycling waste generation in the building and waste sectors has been verified. From a microscopic perspective, the impact of non-permanent electric appliances and stationary and non-stationary occupancy has been investigated. To verify the relationships, various kinds of statistical and data mining techniques were applied, such as the Granger causality test, linear and logarithmic correlation, and regression method. The results show that natural gas and electricity prices are higher than others, as coal impacts their consumption, and electricity and coal consumption were found to cause significant carbon emissions. Also, waste generation and recycling significantly increase and decrease emissions from the waste sector, respectively. Moreover, non-permanent appliances such as desktop computers and monitors consume a lot of electricity, and significant energy saving potential has been shown. Lastly, a linear relationship exists between buildings’ electricity use and total occupancy, but no significant relationship exists between occupancy and thermal loads, such as cooling and heating loads. These findings will potentially provide policymakers with a better understanding of and insights into carbon emission manipulation in the building sector.
ContributorsLee, Seungtaek (Author) / Chong, Oswald (Thesis advisor) / Sullivan, Kenneth (Committee member) / Tang, Pingbo (Committee member) / Arizona State University (Publisher)
Created2018
Description
The winter holiday period has been highlighted as a major risk period for weight gain due to excess caloric intake in the form of fat and sugar. Furthermore, diets high in fat and sugar have been implicated in the pathogenesis of diabetes and cardiovascular disease. Exercise aids in the prevention of weight/fat gain, and prevents deleterious changes in cardiometabolic function. The objective of this study was to examine the effects of a fat-sugar supplemented diet, with and without two different exercise training protocols, on body composition, glycemic control and other markers of cardiovascular disease in an at-risk population of overweight and obese males. Twenty-seven, healthy overweight/obese (BMI >25 kg/m2) males were fed 2 donuts per day, 6 days/week, for four weeks, while maintaining their current diet. In addition, all subjects were randomized to one of the following conditions: sedentary control, 1,000 kcal/week moderate-intensity continuous training (MICT) (50% of peak oxygen consumption), or 1,000 kcal/week high-intensity interval training (HIIT) (90-95% of peak heart rate). Supervised exercise training was performed 4 days/week on a cycle ergometer. Changes in body weight and composition, endothelial function, arterial stiffness, glycemic control, blood lipids and cardiorespiratory fitness (CRF) were assessed before and after the intervention. Body weight, lean mass and visceral fat increased significantly in HIIT (p<0.05) and were unchanged in MICT. There was a trend for a significant increase in body weight (p=0.07) and lean mass (p=0.11) in control. Glycemic control during the 2-h OGTT improved significantly in MICT and control, with no change in HIIT. Hepatic insulin resistance index (IRI) and 30-min insulin during the OGTT improved significantly after MICT and worsened following control (p=0.03), while HIIT was unchanged. CRF increased significantly in both HIIT and MICT, with no change in control (p<0.001). There were no significant changes in other markers of cardiovascular disease. The addition of a fat-sugar supplement (~14,500 kcal) over a 4-week period was not sufficient to induce deleterious changes in body composition and cardiometabolic health in overweight/obese young males. Exercise training did not afford overweight/obese males additional health benefits, with the exception of improvements in fitness and hepatic IRI.
ContributorsTucker, Wesley Jack (Author) / Gaesser, Glenn A (Thesis advisor) / Angadi, Siddhartha S (Committee member) / Whisner, Corrie M (Committee member) / Buman, Matthew P (Committee member) / Shaibi, Gabriel (Committee member) / Arizona State University (Publisher)
Created2016
Description
Background: Latinos have disproportionately high rates of obesity and type 2 diabetes. Family-based interventions may reduce chronic disease risk among Latinos across generations.
Purpose: To assess the efficacy of Athletes for Life (AFL), a 12-week community-and-family-based behavioral intervention, for improving diet, physical activity (PA), anthropometrics, fitness, and biochemical outcomes among mostly Latino parents.
Methods: Parents with at least one child 6-11 years of age were randomized to active AFL participation (n=14) or a wait-list control (n=14) group. AFL consisted of twice weekly 90 minute sessions (45 minutes of nutrition-focused lessons and 45 minutes of PA participation) designed to promote fruit and vegetable consumption, reduction of sugar intake, and increasing habitual PA. Data were collected prior to and immediately after the 12 week intervention.
Results: Participants (37.9±7.2y) were mostly Latino (93%), Spanish speaking (68%), and women (93%). Relative to participants in the control group, AFL participants had a significant reduction in body fat (-1.1±1.2% vs. 0.2±1.2%; p=0.014), resting (-7.6±10.2 bpm vs. +2.1±6.8 bpm; p<0.01), exercise (-8.4±8.7 bpm vs. +0.4±7.3 bpm; p<0.01), and recovery heart rate (-11.9±12.8 bpm vs. -0.3±11.4 bpm; p=0.01), and one mile run time (-1.5±1.0 min vs. -0.1±0.9 min; p<0.01), and a significant increase in estimated VO2 peak (+1.9±1.9 ml/kg/min vs. 0.0±1.8 ml/kg/min; p=0.01). AFL participants also reported an increase in the number of days/week accumulating 30 minutes of MVPA (+0.8±3.2 vs. -1.5±2.3; p=0.004) and daily servings of fruits (+1.3±1.4 vs. +0.3±1.4; p<0.05) and vegetables (+1.8±1.7 vs. +0.1±1.2; p<0.05), relative to control participants. There were no significant differences between groups in changes in diet assessed by 3-day food record, accelerometer-measured PA, weight, blood pressure, visceral fat, biomarkers for cardiovascular disease or nutritional biomarkers.
Conclusions: Despite the lack of effects on diet and PA behaviors, AFL shows promising preliminary efficacy for reducing body fat and improving fitness among adult participants. Future research aimed at improving fitness among Latino parents with family-based intervention is warranted.
Purpose: To assess the efficacy of Athletes for Life (AFL), a 12-week community-and-family-based behavioral intervention, for improving diet, physical activity (PA), anthropometrics, fitness, and biochemical outcomes among mostly Latino parents.
Methods: Parents with at least one child 6-11 years of age were randomized to active AFL participation (n=14) or a wait-list control (n=14) group. AFL consisted of twice weekly 90 minute sessions (45 minutes of nutrition-focused lessons and 45 minutes of PA participation) designed to promote fruit and vegetable consumption, reduction of sugar intake, and increasing habitual PA. Data were collected prior to and immediately after the 12 week intervention.
Results: Participants (37.9±7.2y) were mostly Latino (93%), Spanish speaking (68%), and women (93%). Relative to participants in the control group, AFL participants had a significant reduction in body fat (-1.1±1.2% vs. 0.2±1.2%; p=0.014), resting (-7.6±10.2 bpm vs. +2.1±6.8 bpm; p<0.01), exercise (-8.4±8.7 bpm vs. +0.4±7.3 bpm; p<0.01), and recovery heart rate (-11.9±12.8 bpm vs. -0.3±11.4 bpm; p=0.01), and one mile run time (-1.5±1.0 min vs. -0.1±0.9 min; p<0.01), and a significant increase in estimated VO2 peak (+1.9±1.9 ml/kg/min vs. 0.0±1.8 ml/kg/min; p=0.01). AFL participants also reported an increase in the number of days/week accumulating 30 minutes of MVPA (+0.8±3.2 vs. -1.5±2.3; p=0.004) and daily servings of fruits (+1.3±1.4 vs. +0.3±1.4; p<0.05) and vegetables (+1.8±1.7 vs. +0.1±1.2; p<0.05), relative to control participants. There were no significant differences between groups in changes in diet assessed by 3-day food record, accelerometer-measured PA, weight, blood pressure, visceral fat, biomarkers for cardiovascular disease or nutritional biomarkers.
Conclusions: Despite the lack of effects on diet and PA behaviors, AFL shows promising preliminary efficacy for reducing body fat and improving fitness among adult participants. Future research aimed at improving fitness among Latino parents with family-based intervention is warranted.
ContributorsChavez, Adrian (Author) / Vega-Lopez, Sonia (Thesis advisor) / Crespo, Noe (Committee member) / Hekler, Eric (Committee member) / Shaibi, Gabriel (Committee member) / Bruening, Meg (Committee member) / Arizona State University (Publisher)
Created2015
Description
Nationally, African Americans suffer disproportionately from diabetes; with 13.2% of African Americans diagnosed with diabetes compared to 7.6% of non-Hispanic whites (CDC, 2014). Nearly one-half of all people with diabetes are non-adherent to their oral medications; adherence to insulin therapy was 60%-80% (Brunton et al., 2011; Cramer, 2004; Rubin, 2005). This study explored the question, "What mechanisms are associated with adherence to diabetes medication, including insulin, for African Americans in the Southwest?" Twenty-three people participated in the study; 17 participated in interviews and six participated in gendered focus groups. A community-based participatory research (CBPR) approach engaged the African American community as partners in research.
Major themes emerging from the data included illness perception, support, and the process of medication adherence. Acceptance of the diabetes diagnosis was imperative for medication adherence. Stigmatization of diabetes was salient in the recruitment process and as it related to mechanisms for adherence. Furthermore, many informants were not aware of a family history of diabetes before their own diagnosis. Four gendered emerging typologies were identified, which further illuminated major themes. Moreover, an eight-step process of medication adherence model is discussed. The researcher was able to identify culturally compatible strategies that may be extended to those struggling with medication adherence. The implications section suggests a set of strategies that healthcare providers can present to people with diabetes in order to increase medication adherence.
Major themes emerging from the data included illness perception, support, and the process of medication adherence. Acceptance of the diabetes diagnosis was imperative for medication adherence. Stigmatization of diabetes was salient in the recruitment process and as it related to mechanisms for adherence. Furthermore, many informants were not aware of a family history of diabetes before their own diagnosis. Four gendered emerging typologies were identified, which further illuminated major themes. Moreover, an eight-step process of medication adherence model is discussed. The researcher was able to identify culturally compatible strategies that may be extended to those struggling with medication adherence. The implications section suggests a set of strategies that healthcare providers can present to people with diabetes in order to increase medication adherence.
ContributorsWardian, Jana (Author) / Marsiglia, Flavio F (Thesis advisor) / Sun, Fei (Committee member) / Shaibi, Gabriel (Committee member) / Arizona State University (Publisher)
Created2015