Model for injury to the foreleg of the Thoroughbred racehorse

A discussion is presented of contributing factors to the injury to the foreleg of the Thoroughbred racehorse. The critical part of the step is taken to be the first 10-20 ms after ground contact as the hoof slides forward and stops. Large nonaxial loads associated with the deceleration of the hoof are shown to arise. Results of accelerometer measurements on the hoof of a horse running at racing speed are presented as well as mechanical properties of the racing surface. The mechanical properties of the track surface, the type of shoe, and the degree of fatigue of the horse all work together to determine the level of risk.     

Modelling biological processes under anaerobic conditions through integrating titrimetric and off-gas measurements-applied to EBPR systems.

An innovative method for modelling biological processes under anaerobic conditions is presented and discussed. The method is based on titrimetric and off-gas measurements. Titrimetric data is recorded as the addition rate of hydroxyl ions or protons that is required to maintain pH in a bioreactor at a constant level. An off-gas analysis arrangement measures, among other things, the transfer rate of carbon dioxide. The integration of these signals results in a continuous signal which is solely related to the biological reactions. When coupled with a mathematical model of the biological reactions, the signal allows a detailed characterisation of these reactions, which would otherwise be difficult to achieve. Two applications of the method to the enhanced biological phosphorus removal processes are presented and discussed to demonstrate the principle and effectiveness of the method.     

Human papillomavirus as an etiological factor in cervical cancer: significance for health care practice

The migration of substances from rubber packaging materials into drug products can be significant with certain packaging materials in contact with organic solvent systems. Recommendations for testing drug products for leachables are continually evolving to address new developments. Testing packaging materials using simulated solvents is not always an acceptable protocol for the pharmaceutical industry. We describe a rational strategy for evaluation of the drug product for packaging extractables. A profile of the extractables from rubber packaging materials was made with a range of organic solvents and stress conditions to provide information on substances to target in the drug product. The drug product was evaluated to determine if the matrix would cause interferences that might inhibit detection of the found extractables. Analytical methods were selected based on these findings. The procedures were validated according to FDA guidelines. A stability program using time and storage conditions as variables provided information for acceptance criteria. This same strategy can be used on other types of pharmaceuticals and packaging materials.     

Hepatitis B virus infection, hepatitis B vaccine, and hepatitis B immune globulin

Hepatitis B virus (HBV) infection is a major health problem in the United States; in 1995, approximately 128,000 cases occurred. Transmission of HBV occurs primarily by blood exchange (eg, by shared needles during injection drug use) and by sexual contact. Persons infected early in life are much more likely to become chronically infected than those infected during adulthood: as many as 90% of infants infected perinatally develop chronic infection and up to 25% will die of HBV-related chronic liver disease as adults. Clinical signs of acute hepatitis occur in about 50% of infected adults but in only 5% of infected preschool-aged children. In the United States, hepatitis B vaccine is currently made by recombinant DNA technology using baker's yeast. Preexposure vaccination results in protective antibody levels in almost all infants and children (> 95%) and healthy adults younger than 40 years of age (> 90%). The most common adverse event following administration of hepatitis B vaccine is pain at the injection site, which occurs in 13% to 29% of adult and 3% to 9% of children. A comprehensive hepatitis B vaccination policy is now recommended that includes (1) routine infant vaccination; (2) catch-up vaccination of 11- to 12-year-olds who were not previously vaccinated; (3) catch-up vaccination of young children at high risk for infection; (4) vaccination of adolescents and adults based on lifestyle or environmental, medical, and occupational situations that place them at risk; and (5) prevention of perinatal HBV infection.     

Symbolic control of visual attention: The role of working memory and attentional control settings.

This study examined how 1 symbol is selected to control the allocation of attention when several symbols appear in the visual field. In Experiments 1-3, the critical target feature was color, and it was found that uninformative central arrows that matched the color of the target were selected and produced unintentional shifts of attention (i.e., involuntary, initiated slowly, producing long-lasting facilitatory effects). Experiment 4 tested whether such selection is the result of an attentional filter or of a competition bias due to a match of incoming information against integrated object representations stored in working memory. Here, the critical feature was shape and color was irrelevant, but matching color arrows were still selected. Thus, features of objects in working memory will bias the selection of symbols in the visual field, and such selected symbols are capable of producing unintentional shifts of attention. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Allowables-Based Flow Curves for Nonlinear Finite-Element Analysis

A methodology for developing allowables-based stress versus strain relationships for metal alloys is presented. The approach incorporates Federal Aviation Administration/Department of Defense (FAA/DoD) Metallic Materials Property Development and Standardization (MMPDS) statistically derived material properties for tensile yield and ultimate strengths to derive flow curves at room or elevated temperature with an A-, B-, or S-Basis probability. The resulting flow curves may be used for new designs to comply with Federal Air Regulations as well as for forensic investigations and failure analysis.