Relationship between knee and ankle degeneration in a population of organ donors

<p>Abstract</p> <p>Background</p> <p>Osteoarthritis (OA) is a progressive degenerative condition of synovial joints in response to both internal and external factors. The relationship of OA in one joint of an extremity to another joint within the same extremity, or between extremities, has been a topic of interest in reference to the etiology and/or progression of the disease.</p> <p>Methods</p> <p>The prevalence of articular cartilage lesions and osteophytes, characteristic of OA, was evaluated through visual inspection and grading in 1060 adult knee/tali pairs from 545 cadaveric joint donors.</p> <p>Results</p> <p>Joint degeneration increased more rapidly with age for the knee joint, and significantly more knee joints displayed more severe degeneration than ankle joints from as early as the third decade. Women displayed more severe knee degeneration than did men. Severe ankle degeneration did not exist in the absence of severe knee degeneration. The effect of weight on joint degeneration was joint-specific whereby weight had a significantly greater effect on the knee. Ankle grades increasingly did not match within a donor as the grade of degeneration in either the left or the right knee increased.</p> <p>Conclusions</p> <p>Gender and body type have a greater effect on knee joint integrity as compared to the ankle, suggesting that knees are more prone to internal causative effects of degeneration. We hypothesize that the greater variability in joint health between joints within an individual as disease progresses from normal to early signs of degeneration may be a result of mismatched limb kinetics, which in turn might lead to joint disease progression.</p

Sustainable Reuse of Mine Tailings and Waste Rock as Water-Balance Covers

The focus of this study was to evaluate the potential reuse of mixed mine tailings and waste rock in water-balance covers (WBCs). Reuse of mine waste in geoengineering applications can provide an economic advantage via offsetting raw material requirements and reducing waste volumes to manage. Water-balance covers are designed to minimize percolation and/or oxygen ingress into underlying waste via moisture retention while also providing resistance against slope failure and erosion of cover materials. Water-balance simulations were conducted using a variably-saturated one-dimensional numerical model to assess hydrologic behavior of an actual WBC as well as hypothetical mixed mine waste WBCs. The actual water balance cover included a 1.22-m-thick silty-sand storage layer and a 0.15-m-thick topsoil layer. Three scenarios were evaluated via hydrologic modeling that focused on replacing the actual storage layer with a layer of mine waste: (1) storage layers were simulated as 1.22-m-thick layers of pure mine tailings (i.e., copper, gold, coal, and oil sand tailings); (2) storage layers were simulated as 1.22-m-thick layers of mixed mine tailings and waste rock; and (3) mixed mine tailings and waste rock storage layer thicknesses were redesigned to yield comparable percolation rates as the actual cover

Determination of shear strength values for granular backfill material used by the Wisconsin Department of Transportation

151 p.This study will determine the correlation of various properties and conditions to the friction angle values. Investigation will also determine the variation in these values and recommend allowable design values for the various materials commonly used for backfill for walls and reinforced slopes