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Purpose: Snacking is an important component of dietary intake yet remains understudied, particularly among adolescents who consume 25% of their daily calories from snacks. Previous research provides evidence that adolescents with overweight (OW) and obesity (OB) consume larger and more frequent snacks than adolescents with normal weight (NW). The objective of this study was to compare the food group composition of snacks by weight status as well as to identify snacking patterns and predictors among adolescents in the United States (US). Methods: Anthropometric, dietary, and demographic data from adolescents, 12-19 years old, in the 2005-2016 National Health and Nutrition Examination Survey were analyzed. The mean of the two days of dietary recall was used to measure dietary intake, which serves as a proxy for usual intake. Mean equivalents of the 37 food components present in individual snack foods reported by each adolescent across two days of intake were estimated using the Food Patterns Equivalents Database. Latent Class Analysis (LCA) was used to study the effect of mutually exclusive food component consumption groups. Multivariate logistic regression models were used to analyze membership in relation to dietary quality (Healthy Eating Index 2015 [HEI-2015] scores), weight status (BMI & BMI Z-score), selected snacking parameters (e.g., mean snack calories), and socio-demographic (e.g., race, gender) covariates. Results: Adolescents with two days of reliable dietary recall data and complete anthropometrics were included in the descriptive analysis (n = 6423). Adolescents with NW consumed greater energy, vegetable, whole grains, refined grains, dairy, and solid fat from snacks than adolescents with OW and OB (p < 0.05). LCA identified two main snacking patterns. The “Heavy Snackers” pattern was associated with higher consumption of each food component, total energy and snacking energy while the “Light Snackers” pattern was associated with lower consumption each food component, total energy and snacking energy. After adjustment for energy misreporting, OW or OB classification did not significantly increase the odds of being in either class while being classified with NW decreased the odds of being in the “Heavy Snacker” class. In addition, increasing BMI z-score and HEI-2015 total score increased and decreased the odds of being in the “Heavy Snackers” class respectively. The strongest predictors of a “Heavy Snacker” pattern were male gender, non-Hispanic white race, lower dietary quality, and increased snacking parameters, while female gender, all races except non-Hispanic white, better dietary quality, and decreased snacking parameters were strong predictors of a “Light Snacker” pattern. Conclusion: We can conclude that consuming less foods as snacks contributed positively to weight status and overall diet quality among US adolescents. Findings from this cross-sectional study remain consistent with snacking, diet quality, and weight status associations, but add to existing knowledge with the identification of snack consumption patterns. The dietary patterns derived may provide a useful basis for dietary interventions targeted at snacking among adolescents by recommending light snacking and low consumption of energy dense snack foods. Additional studies are needed to further understand what the main food pattern components are across gender and racial backgrounds and to confirm whether associations between snacking and weight status are due to food quality, quantity, or both. / Epidemiology

During an earthquake, unanchored equipment within a nuclear power plant facility can slide and interact with safety-critical systems and components. Previous studies on sliding have largely focused on the response due to unidirectional excitation, as computing the response of unanchored components in three dimensions can be complex and computationally expensive. As such, several prediction equations and a standardized approximate method as outlined in ASCE 4-16 have been developed to estimate the peak sliding displacement. This study investigates the effect of bidirectional horizontal interaction and the influence of vertical excitation on the sliding response of an unanchored object when the x, y, and z, components of earthquake excitation are applied simultaneously. The study also evaluates the approximate method detailed in ASCE 4-16. A suite of 40 floor acceleration histories obtained from response history analysis of a representative nuclear power plant facility are used as input for the sliding model. A wide range of friction coefficients is selected for analysis and the nonlinear sliding response of components is determined through the use of a Bouc-Wen type hysteretic model. Computed responses under uni-, bi- and tri-directional excitation reveal that the effect of bidirectional interaction and vertical excitation is greatest for sites with high shaking intensity. It is also concluded that the ASCE 4-16 approximate method is significantly overconservative in all cases. Additionally, the study expands the concept of multi-component excitation to intensity measures. Twelve intensity measures are selected and evaluated. It is found that most efficient intensity measures vary in efficiency depending on the coefficient of friction, and that the top intensity measures are not significantly affected by incorporating multiple components of excitation. / Thesis / Master of Applied Science (MASc) / Earthquakes can pose a huge risk to nuclear facilities. Unanchored objects within the facility may collide and interact with safety-critical equipment. Previous research on sliding behaviour lacks information on the response of an object subjected to earthquake excitation in both the horizontal plane and vertical direction simultaneously. Several prediction equations and an approximate method have been developed to estimate the sliding response as it becomes computationally expensive to solve. This research investigates the influence of simulatenous multi-component excitation on the sliding behaviour and evaluates the current standardized approximate method of estimating sliding displacement. Recommendations are given based on the friction coefficient between the object and the base. The research also explores which characteristics of earthquake ground motion (e.g. acceleration, velocity, energy) are most indicative of sliding behaviour.

Sucrose, raffinose, and stachyose make up the majority of the carbohydrates in soybean seeds. While sucrose is a desirable component of soybean seeds, raffinose and stachyose are considered to be anutritive factors and eliminating or reducing them appears to be a beneficial endeavour. The major objective of this study was to determine the genetic mechanism controlling accumulation of soluble saccharides in soybean seeds. An experimental soybean line, V99-5089, with high sucrose (14.6%) content coupled with low amounts of raffinose (0.5%) and stachyose (0.4%) was the center of this study. Three populations were studied and segregation patterns were observed in F2:3 populations. All three sugars were extracted by an aqueous procedure and quantified by high pressure liquid chromatography (HPLC) using a NH2 column and refractive index (RI) detector. Segregation of seeds from F2:3 plants indicated a single, partially recessive gene reduced stachyose content of soybean seeds from about 4% to less than 1%. Estimates of genetic variability indicate the presence of sufficient additive variation in addition to the putative major gene to warrant selection. Raffinose and stachyose were positively correlated to each other and each was negatively correlated with sucrose while there was not a significant correlation between total sugar content and the amount of any of the individual sugars. Agronomic traits evaluated do not appear to be adversely effected by the reduction of stachyose content. Additionally, a negative relationship was observed between inorganic phosphorus and stachyose content of soybean seeds but a relationship was not observed between stachyose and phytate phosphorus or between inorganic phosphorus and phytate phosphorus. / Master of Science

Although the Umultimedia computer kiosk" is a relatively new phenomenon, a great deal of academic research has been conducted on the programming of the systems. Little research has been conducted on the effectiveness of kiosk interface design, however, perhaps due to the lack of a formalized methodology for evaluation. This thesis presents one methodology for the evaluation of graphic components used in the interface of a computer kiosk designed for the United States Forest Service. There are many established conventions for multimedia interface design. Many graphic techniques, such as buttons that change colors and generate an audible click when pressed and "windows" on the screen used for displaying images or text, have become commonplace with the increasing popularity of video games, information kiosks, automated teller machines and automated point of sale systems. This thesis examines the usage patterns of the kiosk by analyzing the sequence of buttons pressed, determines search pattern preferences, the success of a non-standard button is evaluated, and sources of confusion or misunderstanding are identified. This study demonstrates the strengths and weaknesses of both the graphic components and the evaluation methodology, and it provides a foundation for the creation of a formalized approach for the evaluation of computer kiosk interfaces. / Master of Landscape Architecture

With higher demands on biomass, the ability to accurately estimate the amount in a stand is more important now than ever before. Existing models currently in use by the Forest Inventory and Analysis (FIA) program of the United States Department of Agriculture (USDA) Forest Service include the Component Ratio Method (CRM). However, testing of the CRM models is needed to validate and calibrate them. The objective of this research was to test and develop a system of equations capable of producing consistent volume and biomass estimates for standing trees of commercially important hardwood species in the southeastern United States. Testing and comparing was done through use of new and legacy data to establish component ratios of trees and contrast these results to those from existing models. Specifically, analyses were completed for models of merchantable and whole stem volume, wood densities models and averages, and the component ratios for wood, bark, branches, and foliage. The existing models were then calibrated and adjusted. Results on accuracy and fitted results of updated models are reported, along with testing the effects of applying updated models over the state of Virginia. / Master of Science

Yes / Fabrication of extracellular matrix (ECM)-like scaffolds (in terms of structural-functional) is the main challenge in skin tissue engineering. Herein, inspired by macromolecular components of ECM, a novel hybrid scaffold suggested which includes silk/hyaluronan (SF/HA) bio-complex modified by PCP: [polyethylene glycol/chitosan/poly(ɛ-caprolactone)] copolymer containing collagen to differentiate human-adipose-derived stem cells into keratinocytes. In followed by, different weight ratios (wt%) of SF/HA (S1:100/0, S2:80/20, S3:50/50) were applied to study the role of SF/HA in the improvement of physicochemical and biological functions of scaffolds. Notably, the combination of electrospinning-like and freeze-drying methods was also utilized as a new method to create a coherent 3D-network. The results indicated this novel technique was led to ~8% improvement of the scaffold's ductility and ~17% decrease in mean pore diameter, compared to the freeze-drying method. Moreover, the increase of HA (>20wt%) increased porosity to 99%, however, higher tensile strength, modulus, and water absorption% were related to S2 (38.1, 0.32 MPa, 75.3%). More expression of keratinocytes along with growth pattern similar to skin was also observed on S2. This study showed control of HA content creates a microporous-environment with proper modulus and swelling%, although, the role of collagen/PCP as base biocomposite and fabrication technique was undeniable on the inductive signaling of cells. Such a scaffold can mimic skin properties and act as the growth factor through inducing keratinocytes differentiation.

This thesis is the result of an exploration to develop an architectural series of modular units. It is my position that information regarding site and program are unnecessary when beginning an architectural project. This is clearly demonstrated through my process. In the beginning, these units were developed independently of any program or specific site information. After establishing a series of fundamental architectural ideas, they were used to address a specific program. / Master of Architecture

Unlike the conventional "lock-and-key" sensor design in which one sensor is finely tuned to respond to one analyte, the sensor array approach employs multiple sensors in which one sensor responds to many analytes. Consequently, signal processing algorithms must be used to identify the analyte present from the array's response. The analyte identification process becomes significantly more complicated when a mixture of analytes is presented to the sensor array. Conventional methods that are employed in gas mixture identification are plagued by several design issues like: complexity, scalability, and flexibility. This thesis derives and develops a novel method, fingerprint-based ICA (FICA), to extract and identify individual analytes from a sensor array's response to a gas mixture of the analytes. FICA is a simple, flexible, and scalable signal processing system that employs independent components analysis (ICA) to extract and identify individual analytes present in a gas mixture; separation and identification of gas mixtures using ICA has not been investigated previously. FICA takes a fundamentally different approach that reflects the underlying property of gas mixtures: gas mixtures are composed of individual analyte responses. Conventional signal processing methods that identify gas mixtures have been developed and implemented in this work; this helps us understand the drawbacks in the conventional approach. FICA's performance is compared to the performance of conventional methods using metric like error rate and false positives rate. Properties like flexibility, scalability, and the data requirements for both conventional methods and FICA are examined. Results obtained in this work indicates that FICA results in lower error rates, and it's performance is better than conventional methods like multi-stage multi-stage support vector machines, and PCR. Furthermore, FICA provides the most simple, scalable, and flexible signal processing system. / Master of Science