Matching Items (64)
Description
Scientists have used X-rays to study biological molecules for nearly a century. Now with the X-ray free electron laser (XFEL), new methods have been developed to advance structural biology. These new methods include serial femtosecond crystallography, single particle imaging, solution scattering, and time resolved techniques.
The XFEL is characterized by high intensity pulses, which are only about 50 femtoseconds in duration. The intensity allows for scattering from microscopic particles, while the short pulses offer a way to outrun radiation damage. XFELs are powerful enough to obliterate most samples in a single pulse. While this allows for a “diffract and destroy” methodology, it also requires instrumentation that can position microscopic particles into the X-ray beam (which may also be microscopic), continuously renew the sample after each pulse, and maintain sample viability during data collection.
Typically these experiments have used liquid microjets to continuously renew sample. The high flow rate associated with liquid microjets requires large amounts of sample, most of which runs to waste between pulses. An injector designed to stream a viscous gel-like material called lipidic cubic phase (LCP) was developed to address this problem. LCP, commonly used as a growth medium for membrane protein crystals, lends itself to low flow rate jetting and so reduces the amount of sample wasted significantly.
This work discusses sample delivery and injection for XFEL experiments. It reviews the liquid microjet method extensively, and presents the LCP injector as a novel device for serial crystallography, including detailed protocols for the LCP injector and anti-settler operation.
The XFEL is characterized by high intensity pulses, which are only about 50 femtoseconds in duration. The intensity allows for scattering from microscopic particles, while the short pulses offer a way to outrun radiation damage. XFELs are powerful enough to obliterate most samples in a single pulse. While this allows for a “diffract and destroy” methodology, it also requires instrumentation that can position microscopic particles into the X-ray beam (which may also be microscopic), continuously renew the sample after each pulse, and maintain sample viability during data collection.
Typically these experiments have used liquid microjets to continuously renew sample. The high flow rate associated with liquid microjets requires large amounts of sample, most of which runs to waste between pulses. An injector designed to stream a viscous gel-like material called lipidic cubic phase (LCP) was developed to address this problem. LCP, commonly used as a growth medium for membrane protein crystals, lends itself to low flow rate jetting and so reduces the amount of sample wasted significantly.
This work discusses sample delivery and injection for XFEL experiments. It reviews the liquid microjet method extensively, and presents the LCP injector as a novel device for serial crystallography, including detailed protocols for the LCP injector and anti-settler operation.
ContributorsJames, Daniel (Author) / Spence, John (Thesis advisor) / Weierstall, Uwe (Committee member) / Kirian, Richard (Committee member) / Schmidt, Kevin (Committee member) / Arizona State University (Publisher)
Created2015
Description
Background: Childhood obesity is one of the most serious public health concerns in the United States and has been associated with low levels of physical activity. Schools are ideal physical activity promotion sites but school physical activity opportunities have decreased due the increased focus on academic performance. Before-school programs provide a good opportunity for children to engage in physical activity as well as improve their readiness to learn. Purpose: The purpose of this study was to examine the effect of a before-school running/walking club on children's physical activity and on-task behavior. Methods: Participants were third and fourth grade children from two schools in the Southwestern United States who participated in a before-school running/walking club that met two times each week. The study employed a two-phase experimental design with an initial baseline phase and an alternating treatments phase. Physical activity was monitored using pedometers and on-task behavior was assessed through systematic observation. Data analysis included visual analysis, descriptive statistics, as well as multilevel modeling. Results: Children accumulated substantial amounts of physical activity within the before-school program (School A: 1731 steps, 10:02 MVPA minutes; School B: 1502 steps, 8:30 MVPA minutes) and, on average, did not compensate by decreasing their physical activity during the rest of the school day. Further, on-task behavior was significantly higher on days the children attended the before-school program than on days they did not (School A=15.78%, pseudo-R2=.34 [strong effect]; School B=14.26%, pseudo-R2=.22 [moderate effect]). Discussion: Results provide evidence for the positive impact of before-school programs on children's physical activity and on-task behavior. Such programs do not take time away from academics and may be an attractive option for schools.
ContributorsStylianou, Michalis (Author) / Kulinna, Pamela H. (Thesis advisor) / Van Der Mars, Hans (Committee member) / Amazeen, Eric (Committee member) / Adams, Marc (Committee member) / Mahar, Matthew T. (Committee member) / Arizona State University (Publisher)
Created2014
Effect of a Wii Fit® intervention on balance, muscular fitness, and bone health in middle-aged women
Description
Sustaining a fall can be hazardous for those with low bone mass. Interventions exist to reduce fall-risk, but may not retain long-term interest. "Exergaming" has become popular in older adults as a therapy, but no research has been done on its preventative ability in non-clinical populations. The purpose was to determine the impact of 12-weeks of interactive play with the Wii Fit® on balance, muscular fitness, and bone health in peri- menopausal women. METHODS: 24 peri-menopausal-women were randomized into study groups. Balance was assessed using the Berg/FICSIT-4 and a force plate. Muscular strength was measured using the isokinetic dynamometer at 60°/180°/240°/sec and endurance was assessed using 50 repetitions at 240°/sec. Bone health was tracked using dual-energy x-ray absorptiometry (DXA) for the hip/lumbar spine and qualitative ultrasound (QUS) of the heel. Serum osteocalcin was assessed by enzyme immunoassay. Physical activity was quantified using the Women's Health Initiative Physical Activity Questionnaire and dietary patterns were measured using the Nurses' Health Food Frequency Questionnaire. All measures were repeated at weeks 6 and 12, except for the DXA, which was completed pre-post. RESULTS: There were no significant differences in diet and PA between groups. Wii Fit® training did not improve scores on the Berg/FICSIT-4, but improved center of pressure on the force plate for Tandem Step, Eyes Closed (p-values: 0.001-0.051). There were no significant improvements for muscular fitness at any of the angular velocities. DXA BMD of the left femoral neck improved in the intervention group (+1.15%) and decreased in the control (-1.13%), but no other sites had significant changes. Osteocalcin indicated no differences in bone turnover between groups at baseline, but the intervention group showed increased bone turnover between weeks 6 and 12. CONCLUSIONS: Findings indicate that WiiFit® training may improve balance by preserving center of pressure. QUS, DXA and osteocalcin data confirm that those in the intervention group were experiencing more bone turnover and bone formation than the control group. In summary, twelve weeks of strength /balance training with the Wii Fit® shows promise as a preventative intervention to reduce fall and fracture risk in non-clinical middle aged women who are at risk.
ContributorsWherry, Sarah Jo (Author) / Swan, Pamela D (Thesis advisor) / Adams, Marc (Committee member) / Der Ananian, Cheryl (Committee member) / Sweazea, Karen (Committee member) / Vaughan, Linda (Committee member) / Arizona State University (Publisher)
Created2014
Description
Research indicates that adults are not acquiring enough physical activity. Increasing the use of stairs is an accessible way to weave high intensity physical activity into the daily routine. The purpose of this study is to test the effect of four environmental changes on ascending stair use in a mixed population of college students, faulty, and staff on a southwest college campus. The study design included a 10-week time series design with alternating baseline and intervention phases, including a directional cue represented by footprints on the ground, a positive prompt, a deterrent prompt and a combination phase. Data was collected with both an in-person tally and a video recording device. The study included 6,140 observations and coded variables included stair use, sex, number of bags carried, temperature, and volume. Rater reliability ranged from .81 to 1.0. Multivariate logistic regression was used to perform the statistic analysis. Stair use increased significantly from Washout 1 and the positive prompting phase with a 7% absolute increase and an odds ratio of 1.35 (95% CI 1.080-1.696). Stair use during the footprint phase, deterrent phase and combination phase did not increase significantly compared to the previous baseline or washout phases. Day of the week (Monday=reference, Tuesday CI=1.626, 95% CI 1.298-2.011, Wednesday OR=0.457, 95% CI 0.248-0.841, Thursday OR=1.434, 95% CI 1.164-1.766), sex (OR=1.376, 95% CI 1.173-1.613) and volume (OR=1.007, 95% CI 1.005-1.008) were significantly correlated to stair use. Women used the stairs more than men and higher volume situations were related to increased stair use. Temperature and baggage number were not related to stair use. The results of this study indicate that positive prompting with an environmental message theme is an effective method to increase stair use in a university setting.
ContributorsFord, Marley (Author) / Adams, Marc (Thesis advisor) / Der Ananian, Cheryl (Committee member) / Vaughan, Linda (Committee member) / Arizona State University (Publisher)
Created2015
Description
ABSTRACT
X-Ray crystallography and NMR are two major ways of achieving atomic
resolution of structure determination for macro biomolecules such as proteins. Recently, new developments of hard X-ray pulsed free electron laser XFEL opened up new possibilities to break the dilemma of radiation dose and spatial resolution in diffraction imaging by outrunning radiation damage with ultra high brightness femtosecond X-ray pulses, which is so short in time that the pulse terminates before atomic motion starts. A variety of experimental techniques for structure determination of macro biomolecules is now available including imaging of protein nanocrystals, single particles such as viruses, pump-probe experiments for time-resolved nanocrystallography, and snapshot wide- angle x-ray scattering (WAXS) from molecules in solution. However, due to the nature of the "diffract-then-destroy" process, each protein crystal would be destroyed once
probed. Hence a new sample delivery system is required to replenish the target crystal at a high rate. In this dissertation, the sample delivery systems for the application of XFELs to biomolecular imaging will be discussed and the severe challenges related to the delivering of macroscopic protein crystal in a stable controllable way with minimum waste of sample and maximum hit rate will be tackled with several different development of injector designs and approaches. New developments of the sample delivery system such as liquid mixing jet also opens up new experimental methods which gives opportunities to study of the chemical dynamics in biomolecules in a molecular structural level. The design and characterization of the system will be discussed along with future possible developments and applications. Finally, LCP injector will be discussed which is critical for the success in various applications.
X-Ray crystallography and NMR are two major ways of achieving atomic
resolution of structure determination for macro biomolecules such as proteins. Recently, new developments of hard X-ray pulsed free electron laser XFEL opened up new possibilities to break the dilemma of radiation dose and spatial resolution in diffraction imaging by outrunning radiation damage with ultra high brightness femtosecond X-ray pulses, which is so short in time that the pulse terminates before atomic motion starts. A variety of experimental techniques for structure determination of macro biomolecules is now available including imaging of protein nanocrystals, single particles such as viruses, pump-probe experiments for time-resolved nanocrystallography, and snapshot wide- angle x-ray scattering (WAXS) from molecules in solution. However, due to the nature of the "diffract-then-destroy" process, each protein crystal would be destroyed once
probed. Hence a new sample delivery system is required to replenish the target crystal at a high rate. In this dissertation, the sample delivery systems for the application of XFELs to biomolecular imaging will be discussed and the severe challenges related to the delivering of macroscopic protein crystal in a stable controllable way with minimum waste of sample and maximum hit rate will be tackled with several different development of injector designs and approaches. New developments of the sample delivery system such as liquid mixing jet also opens up new experimental methods which gives opportunities to study of the chemical dynamics in biomolecules in a molecular structural level. The design and characterization of the system will be discussed along with future possible developments and applications. Finally, LCP injector will be discussed which is critical for the success in various applications.
ContributorsWang, Dingjie (Author) / Spence, John CH (Thesis advisor) / Weierstall, Uwe (Committee member) / Schmidt, Kevin (Committee member) / Fromme, Petra (Committee member) / Ozkan, Banu (Committee member) / Arizona State University (Publisher)
Created2014
Description
The superior brightness and ultra short pulse duration of X-ray free electron laser
(XFEL) allows it to outrun radiation damage in coherent diffractive imaging since elastic scattering terminates before photoelectron cascades commences. This “diffract-before-destroy” feature of XFEL opened up new opportunities for biological macromolecule imaging and structure studies by breaking the limit to spatial resolution imposed by the maximum dose that is allowed before radiation damage. However, data collection in serial femto-second crystallography (SFX) using XFEL is affected by a bunch of stochastic factors, which pose great challenges to the data analysis in SFX. These stochastic factors include crystal size, shape, random orientation, X-ray photon flux, position and energy spectrum. Monte-Carlo integration proves effective and successful in extracting the structure factors by merging all diffraction patterns given that the data set is sufficiently large to average out all stochastic factors. However, this approach typically requires hundreds of thousands of patterns collected from experiments. This dissertation explores both experimental and algorithmic methods to eliminate or reduce the effect of stochastic factors in data acquisition and analysis. Coherent convergent X-ray beam diffraction (CCB) is discussed for possibilities of obtaining single-shot angular-integrated rocking curves. It is also shown the interference between Bragg disks helps ab-initio phasing. Two-color diffraction scheme is proposed for time-resolved studies and general data collection strategies are discussed based on error metrics. A new auto-indexing algorithm for sparse patterns is developed and demonstrated for both simulated and experimental data. Statistics show that indexing rate is increased by 3 times for I3C data set collected from beam time LJ69 at Linac coherent light source (LCLS). Finally, dynamical inversion from electron diffraction is explored as an alternative approach for structure determination.
(XFEL) allows it to outrun radiation damage in coherent diffractive imaging since elastic scattering terminates before photoelectron cascades commences. This “diffract-before-destroy” feature of XFEL opened up new opportunities for biological macromolecule imaging and structure studies by breaking the limit to spatial resolution imposed by the maximum dose that is allowed before radiation damage. However, data collection in serial femto-second crystallography (SFX) using XFEL is affected by a bunch of stochastic factors, which pose great challenges to the data analysis in SFX. These stochastic factors include crystal size, shape, random orientation, X-ray photon flux, position and energy spectrum. Monte-Carlo integration proves effective and successful in extracting the structure factors by merging all diffraction patterns given that the data set is sufficiently large to average out all stochastic factors. However, this approach typically requires hundreds of thousands of patterns collected from experiments. This dissertation explores both experimental and algorithmic methods to eliminate or reduce the effect of stochastic factors in data acquisition and analysis. Coherent convergent X-ray beam diffraction (CCB) is discussed for possibilities of obtaining single-shot angular-integrated rocking curves. It is also shown the interference between Bragg disks helps ab-initio phasing. Two-color diffraction scheme is proposed for time-resolved studies and general data collection strategies are discussed based on error metrics. A new auto-indexing algorithm for sparse patterns is developed and demonstrated for both simulated and experimental data. Statistics show that indexing rate is increased by 3 times for I3C data set collected from beam time LJ69 at Linac coherent light source (LCLS). Finally, dynamical inversion from electron diffraction is explored as an alternative approach for structure determination.
ContributorsLi, Chufeng (Author) / Spence, John CH (Thesis advisor) / Spence, John (Committee member) / Kirian, Richard (Committee member) / Weierstall, Uwe (Committee member) / Schmidt, Kevin (Committee member) / Arizona State University (Publisher)
Created2016
Description
Phase problem has been long-standing in x-ray diffractive imaging. It is originated from the fact that only the amplitude of the scattered wave can be recorded by the detector, losing the phase information. The measurement of amplitude alone is insufficient to solve the structure. Therefore, phase retrieval is essential to structure determination with X-ray diffractive imaging. So far, many experimental as well as algorithmic approaches have been developed to address the phase problem. The experimental phasing methods, such as MAD, SAD etc, exploit the phase relation in vector space. They usually demand a lot of efforts to prepare the samples and require much more data. On the other hand, iterative phasing algorithms make use of the prior knowledge and various constraints in real and reciprocal space. In this thesis, new approaches to the problem of direct digital phasing of X-ray diffraction patterns from two-dimensional organic crystals were presented. The phase problem for Bragg diffraction from two-dimensional (2D) crystalline monolayer in transmission may be solved by imposing a compact support that sets the density to zero outside the monolayer. By iterating between the measured stucture factor magnitudes along reciprocal space rods (starting with random phases) and a density of the correct sign, the complex scattered amplitudes may be found (J. Struct Biol 144, 209 (2003)). However this one-dimensional support function fails to link the rod phases correctly unless a low-resolution real-space map is also available. Minimum prior information required for successful three-dimensional (3D) structure retrieval from a 2D crystal XFEL diffraction dataset were investigated, when using the HIO algorithm. This method provides an alternative way to phase 2D crystal dataset, with less dependence on the high quality model used in the molecular replacement method.
ContributorsZhao, Yun (Author) / Spence, John C.H. (Thesis advisor) / Schmidt, Kevin (Committee member) / Weierstall, Uwe (Committee member) / Kirian, Richard (Committee member) / Zatsepin, Nadia (Committee member) / Arizona State University (Publisher)
Created2016
Description
The structure-function relation in Biology suggests that every biological molecule has evolved its structure to carry out a specific function. However, for many of these processes (such as those with catalytic activity) the structure of the biomolecule changes during the course of a reaction. Understanding the structure-function relation thus becomes a question of understanding biomolecular dynamics that span a variety of timescales (from electronic rearrangements in the femtoseconds to side-chain alteration in the microseconds and more). This dissertation deals with the study of biomolecular dynamics in the ultrafast timescales (fs-ns) using electron and X-ray probes in both time and frequency domains.
It starts with establishing the limitations of traditional electron diffraction coupled with molecular replacement to study biomolecular structure and proceeds to suggest a pulsed electron source Hollow-Cone Transmission Electron Microscope as an alternative scheme to pursue ultrafast biomolecular imaging. In frequency domain, the use of Electron Energy Loss Spectroscopy as a tool to access ultrafast nuclear dynamics in the steady state, is detailed with the new monochromated NiON UltraSTEM and examples demonstrating this instrument’s capability are provided.
Ultrafast X-ray spectroscopy as a tool to elucidate biomolecular dynamics is presented in studying X-ray as a probe, with the study of the photolysis of Methylcobalamin using time-resolved laser pump – X-ray probe absorption spectroscopy. The analysis in comparison to prior literature as well as DFT based XAS simulations offer good agreement and understanding to the steady state spectra but are so far inadequate in explaining the time-resolved data. However, the trends in the absorption simulations for the transient intermediates show a strong anisotropic dependence on the axial ligation, which would define the direction for future studies on this material to achieve a solution.
It starts with establishing the limitations of traditional electron diffraction coupled with molecular replacement to study biomolecular structure and proceeds to suggest a pulsed electron source Hollow-Cone Transmission Electron Microscope as an alternative scheme to pursue ultrafast biomolecular imaging. In frequency domain, the use of Electron Energy Loss Spectroscopy as a tool to access ultrafast nuclear dynamics in the steady state, is detailed with the new monochromated NiON UltraSTEM and examples demonstrating this instrument’s capability are provided.
Ultrafast X-ray spectroscopy as a tool to elucidate biomolecular dynamics is presented in studying X-ray as a probe, with the study of the photolysis of Methylcobalamin using time-resolved laser pump – X-ray probe absorption spectroscopy. The analysis in comparison to prior literature as well as DFT based XAS simulations offer good agreement and understanding to the steady state spectra but are so far inadequate in explaining the time-resolved data. However, the trends in the absorption simulations for the transient intermediates show a strong anisotropic dependence on the axial ligation, which would define the direction for future studies on this material to achieve a solution.
ContributorsSubramanian, Ganesh (Author) / Spence, John (Thesis advisor) / Rez, Peter (Committee member) / Alford, Terry (Committee member) / Weierstall, Uwe (Committee member) / Kirian, Richard (Committee member) / Arizona State University (Publisher)
Created2016
Description
Chronic diseases are the leading causes of death in the United States. Dietary behaviors influence the risk of developing multiple chronic diseases. The U.S. population consumes too few fruits and vegetables and too much sugar sweetened beverages (SSB) and fast food. The Social Ecological Model (SEM) was created as a framework for health promotion interventions. The SEM organizes factors that can influence health into five layers: intrapersonal factors, interpersonal processes, institutional/organizational factors, community factors, and public policy. Each layer can influence dietary behaviors and other layers.
This work aims to understand how the community layer, represented by the food environment, moderates the association of two other layers and dietary behaviors: the interpersonal layer, represented by receiving health care provider’s (HCP) advice to lose weight, and the policy layer, represented by participation in the Supplemental Nutrition Assistance Program (SNAP), and a policy change within the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).
Participant data were obtained from a household telephone survey of 2,211 adults in four cities in New Jersey from two cross-sectional panels in 2009-10 and 2014. Community food data were purchased and classified according to previously established protocol. Interaction and stratified analyses determined the differences in the association between HCP advice, SNAP participation, and time (for WIC participants) and eating behaviors by the food environment.
Interaction and stratified analyses revealed that HCP advice was associated with a decrease in SSB consumption when participants lived near a small grocery store, or far from a supermarket, limited service restaurant (LSR), or convenience store. SNAP participation was associated with a higher SSB consumption when respondents lived close to a small grocery store, supermarket, and LSR. There were no differences in fruit and vegetable consumption between two time points among WIC participants, or by food outlet.
The food environment, part of the community layer of SEM, moderated the relationship between the interpersonal layer and dietary behaviors and the policy layer and dietary behaviors. The association between HCP advice and dietary behaviors and SNAP participation and dietary behaviors were both influenced by the food environment in which participants lived.
This work aims to understand how the community layer, represented by the food environment, moderates the association of two other layers and dietary behaviors: the interpersonal layer, represented by receiving health care provider’s (HCP) advice to lose weight, and the policy layer, represented by participation in the Supplemental Nutrition Assistance Program (SNAP), and a policy change within the Special Supplemental Nutrition Program for Women, Infants, and Children (WIC).
Participant data were obtained from a household telephone survey of 2,211 adults in four cities in New Jersey from two cross-sectional panels in 2009-10 and 2014. Community food data were purchased and classified according to previously established protocol. Interaction and stratified analyses determined the differences in the association between HCP advice, SNAP participation, and time (for WIC participants) and eating behaviors by the food environment.
Interaction and stratified analyses revealed that HCP advice was associated with a decrease in SSB consumption when participants lived near a small grocery store, or far from a supermarket, limited service restaurant (LSR), or convenience store. SNAP participation was associated with a higher SSB consumption when respondents lived close to a small grocery store, supermarket, and LSR. There were no differences in fruit and vegetable consumption between two time points among WIC participants, or by food outlet.
The food environment, part of the community layer of SEM, moderated the relationship between the interpersonal layer and dietary behaviors and the policy layer and dietary behaviors. The association between HCP advice and dietary behaviors and SNAP participation and dietary behaviors were both influenced by the food environment in which participants lived.
ContributorsLorts, Cori Elizabeth (Author) / Ohri-Vachaspati, Punam (Thesis advisor) / Adams, Marc (Committee member) / Hooker, Steven (Committee member) / Roberto, Anthony (Committee member) / Tasevska, Natasha (Committee member) / Arizona State University (Publisher)
Created2017
Description
Background: Children’s fruit and vegetable consumption in the United States is lower than recommended. School lunch is an opportunity for students to be exposed to fruits and vegetables and potentially increase their daily intake. The purpose of this study is to examine the relationship between tray color and fruit and vegetable selection, consumption, and waste at lunch.
Methods: Study participants (n=1469) were elementary and middle school students who ate school lunch on the day of data collection. Photographs and weights (to nearest 2 g) were taken of fruits and vegetables on students’ trays before and after lunch. Trained research assistants viewed photographs and sorted trays into variable categories: color of main tray, presence/absence of secondary fruit/vegetable container, and color of secondary fruit/vegetable container. Fruit and vegetable selection, consumption, and waste were calculated using tray weights. Negative binomial regression models adjusted for gender, grade level, race/ethnicity, free/reduced price lunch status, and within-school similarities were used to examine relationships between tray color and fruit and vegetable selection, consumption, and waste.
Results: Findings indicated that students with a light tray selected (IRR= 0.44), consumed (IRR=0.73) and wasted (IRR=0.81) less fruit and vegetables. Students without a secondary fruit/vegetable container selected (IRR=0.66) and consumed (IRR=0.49) less fruit and vegetables compared to those with a secondary container. Light or clear secondary fruit and vegetable containers were related to increased selection (IRR=2.06 light, 2.30 clear) and consumption (IRR=1.95 light, 2.78 clear) compared to dark secondary containers, while light secondary containers were related to decreased waste (IRR= 0.57).
Conclusion: Tray color may influence fruit and vegetable selection, consumption, and waste among students eating school lunch. Further research is needed to determine if there is a cause and effect relationship. If so, adjusting container colors may be a practical intervention for schools hoping to increase fruit and vegetable intake among students.
Methods: Study participants (n=1469) were elementary and middle school students who ate school lunch on the day of data collection. Photographs and weights (to nearest 2 g) were taken of fruits and vegetables on students’ trays before and after lunch. Trained research assistants viewed photographs and sorted trays into variable categories: color of main tray, presence/absence of secondary fruit/vegetable container, and color of secondary fruit/vegetable container. Fruit and vegetable selection, consumption, and waste were calculated using tray weights. Negative binomial regression models adjusted for gender, grade level, race/ethnicity, free/reduced price lunch status, and within-school similarities were used to examine relationships between tray color and fruit and vegetable selection, consumption, and waste.
Results: Findings indicated that students with a light tray selected (IRR= 0.44), consumed (IRR=0.73) and wasted (IRR=0.81) less fruit and vegetables. Students without a secondary fruit/vegetable container selected (IRR=0.66) and consumed (IRR=0.49) less fruit and vegetables compared to those with a secondary container. Light or clear secondary fruit and vegetable containers were related to increased selection (IRR=2.06 light, 2.30 clear) and consumption (IRR=1.95 light, 2.78 clear) compared to dark secondary containers, while light secondary containers were related to decreased waste (IRR= 0.57).
Conclusion: Tray color may influence fruit and vegetable selection, consumption, and waste among students eating school lunch. Further research is needed to determine if there is a cause and effect relationship. If so, adjusting container colors may be a practical intervention for schools hoping to increase fruit and vegetable intake among students.
ContributorsWeight, Raquelle (Author) / Bruening, Meg (Thesis advisor) / Adams, Marc (Committee member) / Martinelli, Sarah (Committee member) / Arizona State University (Publisher)
Created2020