Quantifying Variation in Gait Features from Wearable Inertial Sensors Using Mixed Effects Models

The emerging technology of wearable inertial sensors has shown its advantages in collecting continuous longitudinal gait data outside laboratories. This freedom also presents challenges in collecting high-fidelity gait data. In the free-living environment, without constant supervision from researchers, sensor-based gait features are susceptible to variation from confounding factors such as gait speed and mounting uncertainty, which are challenging to control or estimate. This paper is one of the first attempts in the field to tackle such challenges using statistical modeling. By accepting the uncertainties and variation associated with wearable sensor-based gait data, we shift our efforts from detecting and correcting those variations to modeling them statistically. From gait data collected on one healthy, non-elderly subject during 48 full-factorial trials, we identified four major sources of variation, and quantified their impact on one gait outcome—range per cycle—using a random effects model and a fixed effects model. The methodology developed in this paper lays the groundwork for a statistical framework to account for sources of variation in wearable gait data, thus facilitating informative statistical inference for free-living gait analysis

Global stability in a diffusive Holling-Tanner predator-prey model

A diffusive Holling-Tanner predator-prey model with no-flux boundary condition is considered, and it is proved that the unique constant equilibrium is globally asymptotically stable under a new simpler parameter condition. (C) 2011 Elsevier Ltd. All rights reserved

Consumer Behaviors, Added Sugar Intake, Diet Quality, Inflammation and Metabolic Syndrome Risks among Adults from the National Health and Nutrition Examination Survey 2007-2010

We carried out a secondary data analysis of adults aged ≥ 20 years from the National Health and Nutrition Examination Survey (NHANES) 2007-2010. All analyses were weighted using NHANES sample weights to account for the complex survey design, survey non-response, and post-stratification. Overall, the majority of our population (60.4%) exceeded the USDA/HHS recommendation on added sugar consumption. In the first study, soft drink availability at home was positively associated with added sugar intake (p In the second study, added sugar intake was negatively associated with diet quality determined by Healthy Eating Index (HEI) 2015, after adjusting for covariates. With regards to energy and nutrient intakes, excess added sugar intake was significantly related to high energy intake and compromised intakes of most macro- and micro-nutrients. Interestingly, excess added sugar intake was significantly associated with reduced sodium consumption, even after adjusting for energy intake (p\u3c0.001). In our third study, after adjusting for covariates, individuals consuming more than 25% of calories from added sugar in the diet had nearly 4-times likelihood of having low HDL- cholesterol, compared to those consuming ≤10% of calories from added sugar (OR=3.68 among men, p=0.01; OR=3.88 among women, p Together, the results of these studies suggest that certain consumer behaviors may be related to added sugar intake. Consuming excess amount of added sugar in the diet may play a complicated role in affecting diet quality, and in the risks of developing cardio-metabolic abnormalities. Our findings provide evidence for future intervention and policy changes in terms of reducing added sugar intake, to aid in efforts to promote healthy eating and overall health among adults

Exploring Urban Spaces across Human-Natural systems and the Potential to Enhance City Resilience

In dieser Dissertation werden vier Studien durchgeführt, um die acht Arten von Räumen in Mensch-Natur-Systemen für die Widerstandsfähigkeit von Städten vorzuschlagen, die Verbesserung von städtischen Grünflächen unter qualitativen und quantitativen Gesichtspunkten zu analysieren, die Beziehung zwischen UGSLandschaftsmerkmalen und menschlichen Emotionen zu bestimmen und das Konzept der selbstlernenden Stadt für die städtische Raumplanung zu veranschaulichen. (1). Unterschiedliche Strategien in den Acht-Typen-Räumen in Mensch-Natur-Systemen. (2). Verbesserung der städtischen Grünflächen mit natürlichem Angebot und menschlicher Nachfrage. (3). Das Konzept der selbstlernenden Stadt für urbane Nachhaltigkeit. (4) Für die städtische Nachhaltigkeit erfordert die Planung eine Neubewertung der Verbindungen zwischen den verschiedenen menschlichen und natürlichen Systemen mit den Wechselwirkungen zwischen Bedarf und Versorgung Städtische Räume sind komplex, weisen aber in verschiedenen Methoden und Konzepten Regelmäßigkeiten auf. Für eine nachhaltige Entwicklung in Städten sind kreative Denkansätze für die Umsetzung und Integration von sich überschneidenden Räumen, Elementen und Kulturen in städtischen Mensch-Natur-Systemen erforderlich. Um eine nachhaltige Stadt zu schaffen, sind urbane Räume unerlässlich.This dissertation conducts four studies to propose the eight-type spaces in human-natural systems for city resilience, to analyze the improvement of urban green spaces from quality and quantity perspectives, to determine the relationship between UGS landscape characteristics and human emotions and to illustrate the concept of city self-learning for urban space planning. (1). Different strategies in the eight-type spaces across human-natural systems. (2). Improving urban green spaces with natural supply and human demand. (3). The concept of city self-learning for urban sustainability. (4) For urban sustainability, planning requires reevaluating the connections between different human-natural systems with the interactions of demands and supplies. Dissertation title: Exploring Urban Spaces across Human-Natural systems And the Potential to Enhance City Resilience Urban spaces are complex but have regularity in several methods and concepts. For sustainable development in cities, creative ways to think about implementations and integrations utilize crossing spaces, elements, and cultures in urban human-natural systems. To make a sustainable city, urban spaces are essential