The Effects of Locomotion-Induced Shock Loading on Tibiofemoral Bone Stress Response

Purpose/Hypothesis: Knee osteoarthritis (Coats, Zioupos, & Aspden) is a degenerative joint disease that negatively impacts the quality of life. About 9.3 million people in the U.S. population are affected. It has been suggested via magnetic resonance imaging (MRI) studies that bone marrow edema (i.e., indicative of bone stress response) and joint structure changes may be the main contributing factors of pain in OA. Frontal plane lower extremity (LE) alignment has been a topic of much interest regarding development of OA in the knee joint. It is hypothesized that varus alignment increases forces through the medial compartment of the knee, thereby leading to bone stress response and initiation of OA. The purpose was to investigate the effects of locomotion-induced shock loading and LE alignment on tibiofemoral bone stress response in older adults without knee OA. Number of Subjects: Five male and five female subjects with no medical diagnosis of knee OA (57.9 ± 3.9 years; 84.2 ± 12.7 kg; 1.7 ± 0.1 m) participated. Materials/Methods: Each subject underwent a clinical biomechanical testing session and an MRI assessment session. During the clinical biomechanical testing, static LE alignment was obtained by measuring the angle between the long axes of femur and tibia. Dynamic LE alignment, in particular the peak frontal plane LE angle during loading response of fast walking, was obtained using a 3-dimensional motion capturing system. During the MRI assessment session, a chemical-shift-encoded water-fat MRI protocol was applied to the dominant knee. MRI data was obtained before fast walking and immediately following a 30-minute fast walking session. Bone stress response was determined by quantifying the bone water content within the weight-bearing regions of iii the medial and lateral compartments. Paired t-tests were used to compare bone water content before and after fast walking. Pearson correlation coefficient analyses were used to determine the associations between LE alignment and changes in water content after fast walking. Results: The paired t-tests revealed no change in water content after fast walking within medial femur (p = 0.671), lateral femur (p =0.174), medial tibia (p = 0.461), and lateral tibia (p = 0.190). Pearson correlation coefficient analyses revealed a significant moderate correlation between increased bone water content of the medial femur and increased static varus alignment (R = 0.688, p =0.027). Additionally, a trend with moderate correlation was observed between increased bone water content of the medial tibia and increased static varus alignment (R = 0.437, p = 0.206). No association was found between changes in bone water content and dynamic alignment (p \u3c 0.05). Conclusions: This is the first study assessing the acute effects of locomotion on bone stress response in older adults without knee OA. Although there was no significant change in bone water content post locomotion, a greater varus alignment was associated with increased water content in the medial compartment. Clinical Relevance: Our findings provide further understanding of the contribution of LE alignment and development of OA. This research can impact the early detection, prevention, and interventions for individuals at risk for joint deformity and knee OA

A study of the value of art workshop experiences in a summer demonstration school program

This was a study of teachers’ responses concerning art workshop experiences in a summer demonstration school. Three major aspects of the study were: (1) to determine the relative values that teachers placed on selected art experiences, (2) to determine from teachers’ responses the effectiveness of the art workshop program, (3) to identify possible improvements as indicated by the participants in a questionnaire to be described later

New Mechanisms of Micro-Fiber Flocculation and Computer Simulation of Headbox Flow

The objectives of this thesis are 1) to investigate the physical reasons of flocculation, which contribute to nonuniformity in the CD through interactions between fibers in a turbulent flow and 2) to study the effects of velocity profiles in the headbox on variations in the CD by utilizing a computer simulation. Fluid velocities emerging from the headbox vary greatly due to the turbulence generating tube banks. As the fluid exits the tube bank and enters the converging portion of the headbox, patterns formed from the bottom tubes are extended throughout this convergence. This velocity profile is caused by fluid flow characteristics consisting of maximum flow at the center of the tube and velocity at the tube wall that approaches zero, with the bottom tube bank being dominant. With the addition of-fibers to this flow, the velocity gradients tend to rotate fibers to the MD. Upon densification these fiber alignment streaks in the MD contribute greatly to CD variations as localized variations in density. Fiber flocculation is another phenomena that is important to the reduction of CD variations in paper. Local mechanisms extracted from fluidization with water of spherical and cylindrical particles falling against gravity are applied to micro-fiber flocculation. There are essentially three mechanisms to this phenomena: drafting, kissing and tumbling, where interaction in the wake causes flocculation. When fluidized, one fiber is drawn into the wake of another, termed drafting. The second fiber quickly accelerates to make intimate contact with the first, called kissing. Once fibers kiss, they quickly become intertwined due to vortex shedding and create a micro-floe that will continue to grow until turbulence is encountered. This interaction is responsible for the agglomeration that leads to micro-fiber flocculation in the converging portion of the headbox where turbulence is at a minimum. Turbulence is generated by a strip placed on the floor of the headbox perpendicular to the direction of flow. The addition of this strip would add turbulence to the lower portion of the headbox creating a more uniform velocity profile and reducing fiber agglomeration and micro-fiber flocculation. The turbulence distributions are numerically simulated utilizing FLUENT™

Investigating Dimensions of Trust in Public Discussions of Diabetes Led by Certified Diabetes Educators

The givens of “trust” and “credibility” are often glossed over in research concerning the efficacy of community-based approaches to health issues. This research focuses on one type of community intervention aimed at increasing citizens’ interest in acting to address diabetes: a series of community discussions led by Certified Diabetes Educators (CDEs). We take a critical discourse analysis approach to answering several questions including: How does the discourse between CDEs and participants work to establish or hinder the CDEs’ credibility

Comments on the Equity, Efficiency, Incidence and Politics of Impact Fee Methodologies

Development impact fee systems are a controversial topic among developers and planners. This article proposes that the use of locationally-sensitive impact fee methodologies can have positive effects on the cost of development and the price of the final product. The authors caution local officials against jumping on the "development fee bandwagon," and using fees to raise new revenues rather than as a regulatory measure to meet growth needs

A study of the value of art workshop experiences in a summer demonstration school program

This was a study of teachers’ responses concerning art workshop experiences in a summer demonstration school. Three major aspects of the study were: (1) to determine the relative values that teachers placed on selected art experiences, (2) to determine from teachers’ responses the effectiveness of the art workshop program, (3) to identify possible improvements as indicated by the participants in a questionnaire to be described later