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- Genre: Masters Thesis
Description
A wireless hybrid device for detecting volatile organic compounds (VOCs) has been developed. The device combines a highly selective and sensitive tuning-fork based detector with a pre-concentrator and a separation column. The selectivity and sensitivity of the tuning-fork based detector is optimized for discrimination and quantification of benzene, toluene, ethylbenzene, and xylenes (BTEX) via a homemade molecular imprinted polymer, and a specific detection and control circuit. The device is a wireless, portable, battery-powered, and cell-phone operated device. The device has been calibrated and validated in the laboratory and using selected ion flow tube mass spectrometry (SFIT-MS). The capability and robustness are also demonstrated in some field tests. It provides rapid and reliable detection of BTEX in real samples, including challenging high concentrations of interferents, and it is suitable for occupational, environmental health and epidemiological applications.
ContributorsChen, Zheng (Author) / Tao, Nongjian (Thesis advisor) / Chae, Junseok (Committee member) / Forzani, Erica (Committee member) / Arizona State University (Publisher)
Created2011
Description
An imaging measurement technique is developed using surface plasmon resonance. Plasmonic-based electrochemical current imaging (P-ECi) method has been developed to image the local electrochemical current optically, it allows us to measure the current density quickly and non-invasively [1, 2]. In this thesis, we solve the problems when we extand the P-ECi technique to the field of thin film system. The P-ECi signal in thin film structure was found to be directly proportional to the electrochemical current. The upper-limit of thin film thickness to use the proportional relationship between P-ECi signal and EC current was discussed by experiment and simulation. Furthermore, a new algorithm which can calculate the current density from P-ECi signal without any thickness limitation is developed and tested. Besides, surface plasmon resonance is useful phenomenon which can be used to detect the changes in the refractive index near the gold sensing surface. With the assistance of pH indicator, by applied EC potential on the gold film as the working electrode, the detection of H2 evolution reaction can be enhanced. This measurement technique is useful in analyzing local EC information and H2 evolution. References [1] S. Wang, et al., "Electrochemical Surface Plasmon Resonance: Basic Formalism and Experimental Validation," Analytical Chemistry, vol. 82, pp. 935-941, 2010/02/01 2010. [2] X. Shan, et al., "Imaging Local Electrochemical Current via Surface Plasmon Resonance," Science, vol. 327, pp. 1363-1366, March 12, 2010 2010.
ContributorsZhao, Yanjun (Author) / Tao, Nongjian (Thesis advisor) / Wang, Shaopeng (Committee member) / Tsow, Tsing (Committee member) / Arizona State University (Publisher)
Created2013
Description
Fruit and vegetable (FV) consumption continues to lag far behind US Department of Agriculture (USDA) recommendations. Interventions targeting individuals' dietary behaviors address only a small fraction of dietary influences. Changing the food environment by increasing availability of and excitement for FV through local food production has shown promise as a method for enhancing intake. However, the extent to which local production is sufficient to meet recommended FV intakes, or actual intakes, of specific populations remains largely unconsidered. This study was the first of its kind to evaluate the capacity to support FV intake of Arizona's population with statewide production of FV. We created a model to evaluate what percentage of Dietary Guidelines for Americans (DGA) recommendations, as well as actual consumption, state-level FV production could meet in a given year. Intake and production figures were amended to include estimates of only fresh, non-tropical FV. Production was then estimated by month and season to illustrate fluctuations in availability of FV. Based on our algorithm, Arizona production met 184.5% of aggregate fresh vegetable recommendations, as well as 351.9% of estimated intakes of Arizonans, but met only 29.7% of recommended and 47.8% of estimated intake of fresh, non-tropical fruit. Much of the excess vegetable production can be attributed to the dark-green vegetable sub-group category, which could meet 3204.6% and 3160% of Arizonans' aggregated recommendations and estimated intakes, respectively. Only minimal seasonal variations in the total fruit and total vegetable categories were found, but production of the five vegetable sub-groups varied between the warm and cool seasons by 19-98%. For example, in the starchy vegetable group, cool season (October to March) production met only 3.6% of recommendations, but warm season (April to November) production supplied 196.5% of recommendations. Results indicate that Arizona agricultural production has the capacity to meet a large proportion of the population's FV needs throughout much of the year, while at the same time remaining a major producer of dark-green vegetables for out-of-state markets.
ContributorsVaudrin, Nicole (Author) / Wharton, Christopher (Christopher Mack), 1977- (Thesis advisor) / Bruening, Meg (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Villalobos, J. Rene (Committee member) / Arizona State University (Publisher)
Created2013
Description
Objectives Through a cross-sectional observational study, this thesis evaluates the relationship between food insecurity and weight status, eating behaviors, the home food environment, meal planning and preparation, and perceived stress as it relates to predominantly Hispanic/Latino parents in Phoenix, Arizona. The purpose of this study was to address gaps in the literature by examining differences in "healthy" and "unhealthy" eating behaviors, foods available in the home, how time and low energy impact meal preparation, and the level of stress between food security groups. Methods Parents, 18 years or older, were recruited during two pre-scheduled health fairs, from English as a second language classes, or from the Women, Infants, and Children's clinic at a local community center, Golden Gate Community Center, in Phoenix, Arizona. An interview, electronic, or paper survey were offered in either Spanish or English to collect data on the variables described above. In addition to the survey, height and weight were collected for all participants to determine BMI and weight status. One hundred and sixty participants were recruited. Multivariate linear and logistic regression models, adjusting for weight status, education, race/ethnicity, income level, and years residing in the U.S., were used to assess the relationship between food security status and weight status, eating behaviors, the home food environment, meal planning and preparation, and perceived stress. Results Results concluded that food insecurity was more prevalent among parents reporting lower income levels compared to higher income levels (p=0.017). In adjusted models, higher perceived cost of fruits (p=0.004) and higher perceived level of stress (p=0.001) were associated with food insecurity. Given that the sample population was predominately women, a post-hoc analysis was completed on women only. In addition to the two significant results noted in the adjusted analyses, the women-only analysis revealed that food insecure mothers reported lower amounts of vegetables served with meals (p=0.019) and higher use of fast-food when tired or running late (p=0.043), compared to food secure mothers. Conclusion Additional studies are needed to further assess differences in stress levels between food insecure parents and food insecure parents, with special consideration for directionality and its relationship to weight status.
ContributorsVillanova, Christina (Author) / Bruening, Meg (Thesis advisor) / Ohri-Vachaspati, Punam (Committee member) / Vega-Lopez, Sonia (Committee member) / Arizona State University (Publisher)
Created2014
Description
This work demonstrates the integration of a wearable particulate detector and a wireless chemical sensor into a single portable system. The detection philosophy of the chemical sensor is based on highly selective and sensitive microfabricated quartz tuning fork arrays and the particle detector detects the particulate level in real-time using a nephelometric (light scattering) approach. The device integration is realized by carefully evaluating the needs of flow rate, power and data collection. Validation test has been carried out in both laboratory and in field trials such as parking structures and highway exits with high and low traffic emissions. The integrated single portable detection system is capable of reducing the burden for a child to carry multiple devices, simplifying the task of researchers to synchronize and analyze data from different sensors, and minimizing the overall weight, size, and cost of the sensor. It also has a cell phone for data analysis, storage, and transmission as a user-friendly interface. As the chemical and particulate levels present important exposure risks that are of high interests to epidemiologists, the integrated device will provide an easier, wearable and cost effective way to monitor it.
ContributorsGao, Tianle (Author) / Tao, Nongjian (Thesis advisor) / Chae, Junseok (Committee member) / Tsow, Tsing (Committee member) / Arizona State University (Publisher)
Created2012
Description
Advances in miniaturized sensors and wireless technologies have enabled mobile health systems for efficient healthcare. A mobile health system assists the physician to monitor the patient's progress remotely and provide quick feedbacks and suggestions in case of emergencies, which reduces the cost of healthcare without the expense of hospitalization. This work involves development of an innovative mobile health system with adaptive biofeedback mechanism and demonstrates the importance of biofeedback in accurate measurements of physiological parameters to facilitate the diagnosis in mobile health systems. Resting Metabolic Rate (RMR) assessment, a key aspect in the treatment of diet related health problems is considered as a model to demonstrate the importance of adaptive biofeedback in mobile health. A breathing biofeedback mechanism has been implemented with digital signal processing techniques for real-time visual and musical guidance to accurately measure the RMR. The effects of adaptive biofeedback with musical and visual guidance were assessed on 22 healthy subjects (12 men, 10 women). Eight RMR measurements were taken for each subject on different days under same conditions. It was observed the subjects unconsciously followed breathing biofeedback, yielding consistent and accurate measurements for the diagnosis. The coefficient of variation of the measured metabolic parameters decreased significantly (p < 0.05) for 20 subjects out of 22 subjects.
ContributorsKrishnan, Ranganath (Author) / Tao, Nongjian (Thesis advisor) / Forzani, Erica (Committee member) / Yu, Hongyu (Committee member) / Arizona State University (Publisher)
Created2012
Description
Windows based mobile application for m-health and environmental monitoring sensor devices were developed and tested. With the number of smartphone users exponentially increasing, the applications developed for m-health and environmental monitoring devices are easy to reach the general public, if the applications are simple, user-friendly and personalized. The sensing device uses Bluetooth to communicate with the smartphone, providing mobility to the user. Since the device is small and hand-held, the user can put his smartphone in his pocket, connected to the device in his hand and can move anywhere with it. The data processing performed in the applications is verified against standard off the shelf software, the results of the tests are discussed in this document. The user-interface is very simple and doesn't require many inputs from the user other than during the initial setting when they have to enter their personal information for the records. The m-health application can be used by doctors as well as by patients. The response of the application is very quick and hence the patients need not wait for a long time to see the results. The environmental monitoring device has a real-time plot displayed on the screen of the smartphone showing concentrations of total volatile organic compounds and airborne particle count in the environment at the location of the device. The programming was done with Microsoft Visual Studio and was written on VB.NET platform. On the applications, the smartphone receives data as raw binary bytes from the device via Bluetooth and this data is processed to obtain the final result. The final result is the concentration of Nitric Oxide in ppb in the Asthma Analyzer device. In the environmental monitoring device, the final result is the concentration of total Volatile Organic Compounds and the count of airborne Particles.
ContributorsGanesan, Srisivapriya (Author) / Tao, Nongjian (Thesis advisor) / Zhang, Yanchao (Committee member) / Tsow, Tsing (Committee member) / Arizona State University (Publisher)
Created2012
Description
Background: Adequate consumption of fruit and vegetables has been shown to prevent chronic diseases, such as cardiovascular disease, high blood pressure, and type two diabetes. The majority of Americans still consume inadequate daily servings of fruit and vegetables, which include women. Inadequate consumption of fruit and vegetables can be contributed to multiple barriers that hinder consumption in both urban and non-urban areas. The Special Supplemental Nutrition Program for Women, Infant, and Children (WIC) has been shown to positively influence fruit and vegetable consumption by providing healthy foods, such as fruit and vegetables. This study aims to compare the fruit and vegetable consumption of WIC and non-WIC participants between urban and non-urban Rural-Urban Commuting Area (RUCA) codes. Methods: This study was a cross-sectional, secondary analysis of a single time point from the Snuggle Bug/Acurrucadito Study, which had a sample size of (n=53) participants. The participants were separated into two groups, WIC participants, and non-WIC participants, and then further divided based on their respected RUCA code for comparison purposes. The assessment of fruit and vegetable consumption assessment derived from the participant’s 3-day food record. Results: The average consumption of fruit and vegetable consumption among participants was 3.8±2.5 servings There was an inverse relationship between WIC participation and fruit and vegetable consumption among all categories (fruit no juice -0.79, vegetables -0.32, vegetables no potato -0.32, fruit no juice and vegetables -1.1, and fruit no juice and vegetables no potato -1.1). However, none of the results were considered statistically significant. In addition, our study was unable to identify an association between fruit and vegetable consumption and locale due to the small sample size. Conclusions: There was no link observed between fruit and vegetable consumption and WIC participation. Further research of high quality is needed to confirm the relationship between fruit and vegetable consumption of WIC and non-WIC participants in urban and non-urban populations.
ContributorsOrtiz, Steven Michael (Author) / Bruening, Meg (Thesis advisor) / Whisner, Corrie (Committee member) / Shepard, Christina (Committee member) / Arizona State University (Publisher)
Created2022
Description
Background:The second an individual is born, the gut microbiome starts acquiring unique characteristics, including microbial richness and evenness. In addition, it has been found that during infancy, the mode of delivery, antibiotic exposure, feeding patterns, and environment play a role in such development. However, infancy is still an understudied population related to the gut microbiota, specifically its’ connection to two modifiable factors-sleep-wake patterns and its’ interconnection with feeding practices in the first year of life.
Methods:
This secondary data analysis from a randomized longitudinal intervention study assessed the efficacy of a home-based education program in preventing the onset of childhood obesity. A convenience sample of 40 Hispanic mother and infant dyads were recruited to participate in an additional collection of fecal samples to evaluate associations between lifestyle/behavioral factors in infancy and gut microbiome composition in toddlerhood. Total sleep duration and feeding practices (breastmilk and formula) were assessed at one, six, and twelve months. In addition, alpha and beta diversity metrics were assessed from infant stool samples collected at 36 months.
Results:
This study found some significant and trending values for pairwise comparisons of alpha (Shannon Diversity Index) and beta (Bray Curtis and Jaccard Distance). Sleep-wake adequacy consisted of 14-17 total hours of sleep in 24 hours at one month and 12-16 hours for six and twelve months of age. No significant values were identified at one month of age. However, six and twelve months demonstrated significant observations for gut microbial richness and evenness. Trending differences (p=.06, Shannon Diversity Index) persisted in infants receiving adequate sleep at six months but for different feeding modalities. Faith’s PD, Pielou’s measure, and observed OTUs were three additional alpha-diversity metrics performed in all groups. Observed OTUs (p=.03) and Faith’s PD (p=.03) were significant at twelve months, demonstrating an increased microbial feature in infants receiving adequate sleep.
Conclusion:
The findings from this study may show how different timestamps in the first year of life may create gut microbial milestones. However, the interrelation between sleep-wake patterns, feeding modalities, and gut microbiome development is limited; further investigation is needed to monitor close changes and potentially create a criterion
ContributorsAlanis, Victoria (Author) / Whisner, Corrie M. (Thesis advisor) / Petrov, Megan E. (Committee member) / Bruening, Meg (Committee member) / Arizona State University (Publisher)
Created2022
Description
Purpose: Although numerous studies exist regarding the health impact of the Special, Supplemental Program for Women, Infants and Children (WIC) and the Supplemental Nutrition Assistance Program (SNAP) on their participants’, limited studies have examined how participation in one federal nutrition assistance program, may impact participation or perceived benefit of the other. This study aimed to examine how SNAP participation may impact weight-related pregnancy outcomes and participation of pregnant WIC participants. Methods: The present study is a cross-sectional, secondary data analysis of data available from the Arizona Department of Health Services. A total of 35,659 pregnant woman participated in the Arizona WIC program during 2018 and were included in the study. Pregnant participants were assigned to Group WIC or Group WIC+SNAP respectively. Data was aggregated to the clinic level and clinics with less than 10 pregnant participants were combined for a total of 101 clinics included in the analysis. Weight-related pregnancy outcomes measures included average pre-pregnancy weight, average gestational weight gain, BMI class, and delivery weight. Participation indicator outcomes included average number of visits during pregnancy, timing of first prenatal and postnatal WIC appointment, and entry into WIC within the first trimester. Race, ethnicity, language, and education were also analyzed.
Results: This study found average pre-pregnancy weight was statistically significant for women in group SNAP+WIC weighing 2.8 kg more than women in group WIC(p<0.001). Group WIC had a lower delivery weight average (p<0.001) and a higher amount of women beginning pregnancy with a normal BMI (p=0.004). Group WIC participants were statistically more likely to not enroll in WIC during the first trimester compared with Group WIC+SNAP (p=0.049). Group WIC was more likely to enroll in the 8th (p=0.045) and 9th month (p=0.009) of pregnancy and attend their first postpartum visit 6 months after delivery (p=0.007) as compared to Group WIC+SNAP.
Conclusions: This study found that pregnant WIC participants, not enrolled in SNAP have a lower pre-pregnancy weight and are more likely not to enroll within the first trimester. Future research should focus on individualized characteristics of WIC participants to further improve prenatal and postnatal support.
ContributorsStolworthy, Alexandra (Author) / Bruening, Meg (Thesis advisor) / Wadhera, Devina (Committee member) / Whisner, Corrie (Committee member) / Arizona State University (Publisher)
Created2022