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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.
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.
Purpose: The purpose of this study was to understand how implementing EIM influenced provider behaviors in a university-based healthcare system, using a process evaluation.
Methods: A multiple baseline, time series design was used. Providers were allocated to three groups. Group 1 (n=11) was exposed to an electronic medical record (EMR) systems change, EIM-related resources, and EIM training session. Group 2 (n=5) received the EMR change and resources but no training. Group 3 (n=6) was only exposed to the systems change. The study was conducted across three phases. Outcomes included asking about patient physical activity (PA) as a vital sign (PAVS), prescribing PA (ExRx), and providing PA resources or referrals. Patient surveys and EMR data were examined. Time series analysis, chi-square, and logistic regression were used.
Results: Patient survey data revealed the systems change increased patient reports of being asked about PA, χ2(4) = 95.47, p < .001 for all groups. There was a significant effect of training and resource dissemination on patients receiving PA advice, χ2(4) = 36.25, p < .001. Patients receiving PA advice was greater during phase 2 (OR = 4.7, 95% CI = 2.0-11.0) and phase 3 (OR = 2.9, 95% CI = 1.2-7.4). Increases were also observed in EMR data for PAVS, χ2(2) = 29.27, p <. 001 during implementation for all groups. Increases in PA advice χ2(2) = 140.90, p < .001 occurred among trained providers only. No statistically significant change was observed for ExRx, PA resources or PA referrals. However, visual analysis showed an upwards trend among trained providers.
Conclusions: An EMR systems change is effective for increasing the collection of the PAVS. Training and resources may influence provider behavior but training alone increased provider documentation. The low levels of documented outcomes for PA advice, ExRx, resources, or referrals may be due to the limitations of the EMR system. This approach was effective for examining the EIM Solution and scaled-up, longer trials may yield more robust results.
The relation between flux and fluctuation is fundamental to complex physical systems that support and transport flows. A recently obtained law predicts monotonous enhancement of fluctuation as the average flux is increased, which in principle is valid but only for large systems. For realistic complex systems of small sizes, this law breaks down when both the average flux and fluctuation become large. Here we demonstrate the failure of this law in small systems using real data and model complex networked systems, derive analytically a modified flux-fluctuation law, and validate it through computations of a large number of complex networked systems. Our law is more general in that its predictions agree with numerics and it reduces naturally to the previous law in the limit of large system size, leading to new insights into the flow dynamics in small-size complex systems with significant implications for the statistical and scaling behaviors of small systems, a topic of great recent interest.
An outstanding and fundamental problem in contemporary physics is to include and probe the many-body effect in the study of relativistic quantum manifestations of classical chaos. We address this problem using graphene systems described by the Hubbard Hamiltonian in the setting of resonant tunneling. Such a system consists of two symmetric potential wells separated by a potential barrier, and the geometric shape of the whole domain can be chosen to generate integrable or chaotic dynamics in the classical limit. Employing a standard mean-field approach to calculating a large number of eigenenergies and eigenstates, we uncover a class of localized states with near-zero tunneling in the integrable systems. These states are not the edge states typically seen in graphene systems, and as such they are the consequence of many-body interactions. The physical origin of the non-edge-state type of localized states can be understood by the one-dimensional relativistic quantum tunneling dynamics through the solutions of the Dirac equation with appropriate boundary conditions. We demonstrate that, when the geometry of the system is modified to one with chaos, the localized states are effectively removed, implying that in realistic situations where many-body interactions are present, classical chaos is capable of facilitating greatly quantum tunneling. This result, besides its fundamental importance, can be useful for the development of nanoscale devices such as graphene-based resonant-tunneling diodes.
Dynamical systems based on the minority game (MG) have been a paradigm for gaining significant insights into a variety of social and biological behaviors. Recently, a grouping phenomenon has been unveiled in MG systems of multiple resources (strategies) in which the strategies spontaneously break into an even number of groups, each exhibiting an identical oscillation pattern in the attendance of game players. Here we report our finding of spontaneous breakup of resources into three groups, each exhibiting period-three oscillations. An analysis is developed to understand the emergence of the striking phenomenon of triple grouping and period-three oscillations. In the presence of random disturbances, the triple-group/period-three state becomes transient, and we obtain explicit formula for the average transient lifetime using two methods of approximation. Our finding indicates that, period-three oscillation, regarded as one of the most fundamental behaviors in smooth nonlinear dynamical systems, can also occur in much more complex, evolutionary-game dynamical systems. Our result also provides a plausible insight for the occurrence of triple grouping observed, for example, in the U.S. housing market.
Understanding the dynamics of human movements is key to issues of significant current interest such as behavioral prediction, recommendation, and control of epidemic spreading. We collect and analyze big data sets of human movements in both cyberspace (through browsing of websites) and physical space (through mobile towers) and find a superlinear scaling relation between the mean frequency of visit〈f〉and its fluctuation σ : σ ∼〈f⟩β with β ≈ 1.2. The probability distribution of the visiting frequency is found to be a stretched exponential function. We develop a model incorporating two essential ingredients, preferential return and exploration, and show that these are necessary for generating the scaling relation extracted from real data. A striking finding is that human movements in cyberspace and physical space are strongly correlated, indicating a distinctive behavioral identifying characteristic and implying that the behaviors in one space can be used to predict those in the other.
The phenomenon of Fano resonance is ubiquitous in a large variety of wave scattering systems, where the resonance profile is typically asymmetric. Whether the parameter characterizing the asymmetry should be complex or real is an issue of great experimental interest. Using coherent quantum transport as a paradigm and taking into account of the collective contribution from all available scattering channels, we derive a universal formula for the Fano-resonance profile. We show that our formula bridges naturally the traditional Fano formulas with complex and real asymmetry parameters, indicating that the two types of formulas are fundamentally equivalent (except for an offset). The connection also reveals a clear footprint for the conductance resonance during a dephasing process. Therefore, the emergence of complex asymmetric parameter when fitting with experimental data needs to be properly interpreted. Furthermore, we have provided a theory for the width of the resonance, which relates explicitly the width to the degree of localization of the close-by eigenstates and the corresponding coupling matrices or the self-energies caused by the leads. Our work not only resolves the issue about the nature of the asymmetry parameter, but also provides deeper physical insights into the origin of Fano resonance. Since the only assumption in our treatment is that the transport can be described by the Green’s function formalism, our results are also valid for broad disciplines including scattering problems of electromagnetic waves, acoustics, and seismology.