The Relationship Between Self-Concept And Perceived Chronic Pain In Elders

The purpose of this descriptive, correlational study was to determine the relationship between perceived chronic pain and self-concept in elders

Influence of aggregate type and gradation on critical voids in the mineral aggregate in asphalt paving mixtures

The implementation of Superpave has led to concerns with volumetric mix design; in particular, the minimum voids in the mineral aggregate (VMA) requirements, which are based exclusively on nominal maximum aggregate size (NMAS). Achieving the minimum VMA requirement is one of the most difficult tasks in Superpave volumetric mix design. Under current specifications, many otherwise sound mixtures are subject to rejection solely on the basis of failing to meet the VMA requirement;The goal of this research was to validate the existing VMA criterion and to see if including additional aggregate factors would improve it. The work was accomplished in three phases: a literature review; extensive laboratory testing; and statistical analysis of test results;The available literature on the development of the minimum VMA criterion is sketchy; the relationship was originally presented without supporting research or data and the suggestion that it would be modified with experience and test data. The literature review also suggested that the triaxial test was the preferred laboratory test for identifying when a mixture transitions from sound to unsound behavior, i.e., becomes plastic;The laboratory testing involved triaxial testing with the Nottingham Asphalt Tester of 36 mixes with different aggregate properties. ANOVA and linear regression was used to examine the effects of identified aggregate factors on critical state transitions in asphalt paving mixtures and to develop predictive equations;The results clearly demonstrate that the volumetric conditions of an asphalt mixture at the stable/unstable threshold are influenced by a composite measure of the maximum aggregate size and gradation and by aggregate shape and texture. The currently defined VMA criterion, while significant, is seen to be insufficient, by itself, to correctly differentiate sound from unsound mixtures. Based on the laboratory data and statistical analysis, a new paradigm to volumetric mix design is proposed that explicitly accounts for several aggregate factors (gradation, shape, and texture) in predicting the critical VMA of an asphalt paving mixture

The development and use of a cage-topper to enhance rat welfare

The welfare of rats used in scientific research is an important concern. A number of recent studies have demonstrated that larger and more complex housing provides a welfare benefit to rats over conventional cages. However, there are typically both practical and financial constraints to implementing this. We have developed a cage topper that can be added to a standard rat cage to provide additional space and complexity and that can be built in-house at a low cost. Here, we introduce the design of this cage topper and discuss its utility from the perspective of a researcher, a named animal care and welfare officer (NACWO)/lead technician, and a named veterinary surgeon (NVS). We conclude that while the cage topper is likely to provide a welfare benefit, more research is needed to assess if there are any adverse effects of the cage topper on animal health and biosecurity. At present, the cage topper may be most useful to enhance to welfare of rats who are healthy and would otherwise be housed in non-IVC conventional cages