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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
Purpose: To examine: (1) whether Non-Hispanic Blacks (NHB) and Non-Hispanic Whites (NHW) with diagnosed arthritis differed in self-reported physical activity (PA) levels, (2) if NHB and NHW with arthritis differed on potential correlates of PA based on the Social Ecological Model (Mcleroy et al., 1988), and (3) if PA participation varied by race/ethnicity after controlling for age, gender, education, and BMI. Methods: This study was a secondary data analysis of data collected from 2006-2008 in Chicago, IL as part of the Midwest Roybal Center for Health Promotion. Bivariate analyses were used to assess potential differences between race in meeting either ACR or ACSM PA guidelines. Comparisons by race between potential socio-demographic correlates and meeting physical activity guidelines were assessed using Chi-squares. Potential differences by race in psychosocial, arthritis, and health-related and environmental correlates were assessed using T-tests. Finally, logistic regression analyses were used to examine if race was still associated with PA after controlling for socio-demographic characteristics. Results: A greater proportion of NHW (68.1% and 35.3%) than NHB (46.5% and 20.9%) met both the arthritis-specific and the American College of Sports Medicine (ACSM) recommendations for physical activity, respectively. NHB had significantly lower self-efficacy for exercise and reported greater impairments in physical function compared to NHW. Likewise, NHB reported more crime and less aesthetics within their neighborhood. NHW were 2.56 times more likely to meet arthritis-specific PA guidelines than NHB after controlling for age, gender, education, marital status, and BMI. In contrast, after controlling for sociodemographic characteristics, age and gender were the only significant predictors of meeting ACSM PA guidelines. Discussion: There were significant differences between NHB and NHW individuals with arthritis in meeting PA guidelines. After controlling for age, gender, education, and BMI non-Hispanic White individuals were still significantly more likely to meet PA guidelines. Interventions aimed at promoting higher levels of physical activity among individuals with arthritis need to consider neighborhood aesthetics and crime when designing programs. More arthritis-specific programs are needed in close proximity to neighborhoods in an effort to promote physical activity.
ContributorsChuran, Christopher (Author) / Der Ananian, Cheryl (Thesis advisor) / Adams, Marc (Committee member) / Campbell, Kathryn (Committee member) / Arizona State University (Publisher)
Created2013
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
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
Objective: Increasing fruit/vegetable (FV) consumption and decreasing waste during the school lunch is a public health priority. Understanding how serving style of FV impacts FV consumption and waste may be an effective means to changing nutrition behaviors in schools. This study examined whether students were more likely to select, consume, and waste FV when FVs were cut vs. whole. Methods: Baseline data from the ASU School Lunch Study was used to explore associations between cut vs. whole FV serving style and objectively measured FV selection, consumption, and waste and grade level interactions among a random selection of students (n=6804; 47.8% female; 78.8% BIPOC) attending Arizona elementary, middle, and high schools (N=37). Negative binomial regression models evaluated serving style on FV weight (grams) selected, consumed, and wasted, adjusted for sociodemographics and school.
Results: Students were more likely to select cut FVs (IRR=1.11; 95% CI: 1.04, 1.18) and waste cut FVs (IRR=1.20; 95% CI: 1.04, 1.39); however, no differences were observed in the overall consumption of cut vs. whole FVs. Grade-level interactions impacted students’ selection of FVs. Middle school students had a significantly higher effect modification for the selection of cut FVs (IRR=1.18; p=0.006) compared to high school and elementary students. Further, high school students had a significantly lower effect modification for the selection of cut FVs (IRR=0.83; p=0.010) compared to middle and elementary students. No other grade-level interactions were observed.
Discussion: Serving style of FV may impact how much FV is selected and wasted, but further research is needed to determine causality between these variables.
ContributorsJames, Amber Chandarana (Author) / Bruening, Meredith (Thesis advisor) / Adams, Marc (Thesis advisor) / Koskan, Alexis (Committee member) / Arizona State University (Publisher)
Created2021
The Association Between Time to Eat and Students Fruit & Vegetable Consumption, Selection, and Waste
Description
Background: Studies have examined student fruit/vegetable (FV) consumption, selection, and waste related to lunch duration and found that longer duration at lunch was associated with greater consumption, selection, and reduced waste. However, few studies have investigated the relationship between time to eat and FVs. The aim of this research is to analyze the relationship between objective time to students took to eat (“time to eat”) as it relates to their fruit and vegetable consumption, selection, and plate waste.in elementary, middle, and high schools. Methods: A secondary analysis of cross-sectional study of 37 Arizona schools to discover the differences in the selection, consumption, and waste of FVs from students (Full N = 2226, Elementary N = 630, Middle School N = 699, High School N = 897) using objective time to eat measures. Zero-inflated negative binomial regressions examined differences in FV grams selected, consumed, and wasted adjusted for sociodemographics including race, ethnicity, eligibility for free or reduced lunch, academic year, and sex and clustering for students within schools. Results are presented across school level (elementary, middle, and high school).
Results: The average time taken to eat ranged from 10-12 minutes for all students. The association of time to eat and lunch duration were not closely related (r=0.03, p = 0.172). In the count model for every additional minute spent, there was a 0.5% greater likelihood of selecting FVs for elementary kids among those who took any FVs. In the zero-inflated model, it was found that there was a statistically significant relationship between time spent eating and the selection of fruits and vegetables. For the total sample and high schoolers, a minute more of eating time was associated with a 4.3% and 8.8% greater odds of selecting FV. This means that longer eating time increased the likelihood of choosing fruits and vegetables. The results indicated that the longer students took to eat, the higher the likelihood of consuming more of FVs. Each 10 more minutes spent eating (i.e., time to eat) is associated with a 5% increase in grams of FV selected relative to mean (for those that chose FV) over 1 week this equates to 32 g increase of FV selected. However, for middle schoolers, the time to eat was not found to be significant in relation to the grams of fruits and vegetables consumed. There was some significance in the sociodemographic factors such as gender (all) and other (middle school). There was a relationship between time taken to eat and waste as a proportion for fruits and vegetables. For example, among those among the students who wasted something (as a proportion of selection), each additional 10 minutes of eating time was associated with a .6% decrease in waste relative to the mean (for those who chose fruits and vegetables) over a week, resulting in a decrease in waste percentage of 16.5%. Among high schoolers, males had a slightly higher odds of wasting a proportion of fruits and vegetables.
Conclusions: This study aimed to examine the association between the time students take to eat during lunch and their fruit and vegetable (FV) consumption, selection, and plate waste. The findings revealed that the time to eat was related to FV consumption, depending on the school level. However, it was not significantly associated with FV selection or waste. The study emphasized the need for further research on time to eat, distinguishing it from the duration of lunch. Longer lunch periods and adequate time could influence better food choices, increased FV consumption, and reduced waste. The study highlighted the importance of interventions and school policies promoting healthier food choices and providing sufficient time for students to eat. Future research should validate these findings and explore the impact of socialization opportunities on promoting healthier eating habits. Understanding the relationship between lunch duration, time to eat, and students' dietary behaviors can contribute to improved health outcomes and inform effective strategies in school settings.
ContributorsDandridge, Christina Marie (Author) / Adams, Marc (Thesis advisor) / Whisner, Corrie (Committee member) / Bruening, Meg (Committee member) / Arizona State University (Publisher)
Created2023
Description
Most drugs work by binding to receptors on the cell surface. These receptors can then carry the message into the cell and have a wide array of results. However, studying how fast the binding is can be difficult. Current methods involve extracting the receptor and labeling them, but both these steps have issues. Previous works found that binding on the cell surface is accompanied with a small change in cell size, generally an increase. They have also developed an algorithm that can track these small changes without a label using a simple bright field microscope. Here, this relationship is further explored by comparing edge tracking results to a more widely used method, surface plasmon resonance. The kinetic constants found from the two methods are in agreement. No corrections or manipulations were needed to create agreement. The Bland-Altman plots shows that the error between the two methods is about 0.009 s-1. This is about the same error between cells, making it a non-dominant source of error.
ContributorsHunt, Ashley (Author) / Tao, Nongjian (Thesis advisor) / Ros, Alexandra (Committee member) / Borges, Chad (Committee member) / Arizona State University (Publisher)
Created2018
Description
Objective: It’s not well understood how youth perceive existing fruit and vegetable (FV) marketing materials available in schools. This ancillary study sought to assess the acceptability of FV marketing materials freely available to schools among adolescents in grades 6-12.
Methods: Middle and high school adolescents (n=40; 50% female; 52.5% Hispanic) in the Phoenix, AZ area were asked to rank marketing materials (n=35) from favorite to least favorite in four categories: table tents, medium posters, large posters and announcements. Favorites were determined by showing participants two items at a time and having them choose which they preferred; items were displayed to each adolescent in a random order. Adolescents participated in a 20-30 minute interview on their favorite items in each category based on acceptance/attractiveness, comprehension, relevance, motivation and uniqueness of the materials. A content analysis was performed on top rated marketing materials. Top rated marketing materials were determined by the number of times the advertisement was ranked first in its category.
Results: An analysis of the design features of the items indicated that most participants (84%) preferred marketing materials with more than 4 color groups. Participant preference of advertisement length and word count was varied. A total of 5 themes and 20 subthemes emerged when participants discussed their favorite FV advertisements. Themes included: likes (e.g., colors, length, FV shown), dislikes (e.g., length, FV shown), health information (e.g., vitamin shown), comprehension (e.g., doesn’t recognize FV), and social aspects (e.g., peer opinion). Peer opinion often influenced participant opinion on marketing materials. Participants often said peers wouldn’t like the advertisements shown: “…kids my age think that vegetables are not good, and they like food more than vegetables.” Fruits and vegetable pictured as well as the information in the marketing materials also influenced adolescent preference.
Conclusion: Students preferred advertisements with more color and strong visual aspects. Word count had minimal influence on their opinions of the marketing materials, while information mentioned and peer opinion did have a positive effect. Further research needs to be done to determine if there is a link between adolescent preferences on FV marketing materials and FV consumption habits.
Methods: Middle and high school adolescents (n=40; 50% female; 52.5% Hispanic) in the Phoenix, AZ area were asked to rank marketing materials (n=35) from favorite to least favorite in four categories: table tents, medium posters, large posters and announcements. Favorites were determined by showing participants two items at a time and having them choose which they preferred; items were displayed to each adolescent in a random order. Adolescents participated in a 20-30 minute interview on their favorite items in each category based on acceptance/attractiveness, comprehension, relevance, motivation and uniqueness of the materials. A content analysis was performed on top rated marketing materials. Top rated marketing materials were determined by the number of times the advertisement was ranked first in its category.
Results: An analysis of the design features of the items indicated that most participants (84%) preferred marketing materials with more than 4 color groups. Participant preference of advertisement length and word count was varied. A total of 5 themes and 20 subthemes emerged when participants discussed their favorite FV advertisements. Themes included: likes (e.g., colors, length, FV shown), dislikes (e.g., length, FV shown), health information (e.g., vitamin shown), comprehension (e.g., doesn’t recognize FV), and social aspects (e.g., peer opinion). Peer opinion often influenced participant opinion on marketing materials. Participants often said peers wouldn’t like the advertisements shown: “…kids my age think that vegetables are not good, and they like food more than vegetables.” Fruits and vegetable pictured as well as the information in the marketing materials also influenced adolescent preference.
Conclusion: Students preferred advertisements with more color and strong visual aspects. Word count had minimal influence on their opinions of the marketing materials, while information mentioned and peer opinion did have a positive effect. Further research needs to be done to determine if there is a link between adolescent preferences on FV marketing materials and FV consumption habits.
ContributorsPisano, Sydney Alexis (Author) / Bruening, Meg (Thesis advisor) / Adams, Marc (Committee member) / Grgich, Traci (Committee member) / Arizona State University (Publisher)
Created2019