Caregivers' Social Capital and Satisfaction with their Children's Service Providers

The authors examine children's access to and caregiver's satisfaction with organizations that provide leisure time activities for children on Saturdays. The authors argue that access and satisfaction are a function of familie's financial, cultural and social capital. Using data on 1,036 households in the Phoenix metropolitan area in 2003-04, the authors found that families' financial and cultural capital affected whether or not children participate din activities organized by organizations, but family ties to the organization directly (e.g., either worked there, volunteered, donated) resulted in caregivers being more satisfied with the services. The authors also found that the benefits of network closure (caregivers knowing the parents of other children on site) were greater the riskier the activities of the child (e.g., sports or cheerleading). Contrary to the authors expectations, having family or friends in the area did not affect caregiver's satisfaction with the child's provider.

Static and Dynamic Error Correction of a Computer-Aided Mechanical Navigation Linkage for Arthroscopic Hip Surgery

While beneficially decreasing the necessary incision size, arthroscopic hip surgery increases the surgical complexity due to loss of joint visibility. To ease such difficulty, a computer-aided mechanical navigation system was developed to present the location of the surgical tool relative to the patient¿s hip joint. A preliminary study reduced the position error of the tracking linkage with limited static testing trials. In this study, a correction method, including a rotational correction factor and a length correction function, was developed through more in-depth static testing. The developed correction method was then applied to additional static and dynamic testing trials to evaluate its effectiveness. For static testing, the position error decreased from an average of 0.384 inches to 0.153 inches, with an error reduction of 60.5%. Three parameters utilized to quantify error reduction of dynamic testing did not show consistent results. The vertex coordinates achieved 29.4% of error reduction, yet with large variation in the upper vertex. The triangular area error was reduced by 5.37%, however inconsistent among all five dynamic trials. Error of vertex angles increased, indicating a shape torsion using the developed correction method. While the established correction method effectively and consistently reduced position error in static testing, it did not present consistent results in dynamic trials. More dynamic paramters should be explored to quantify error reduction of dynamic testing, and more in-depth dynamic testing methodology should be conducted to further improve the accuracy of the computer-aided nagivation system.