Directional Variability of the Isometric Force Vector Produced by the Human Hand in Multijoint Planar Tasks

Numerous studies have examined control of force magnitude, but relatively little research has considered force direction control. The subjects applied isometric forces to a handle and the authors compared within-trial variability when force is produced in different directions. The standard deviation of the force parallel to the prescribed direction of force production increased linearly with the targeted force level, as did the standard deviation of the force perpendicular to the instructed direction. In contrast, the standard deviation of the angle of force production decreased with increased force level. In the 4 (of 8) instructed force directions where the endpoint force was generated due to a joint torque in only 1 joint (either the shoulder or elbow) the principal component axes in force space were well aligned with the prescribed direction of force production. In the other directions, the variance was approximately equal along the 2 force axes. The variance explained by the first principal component was significantly larger in torque space compared to the force space, and mostly corresponded to positive correlation between the joint torques. Such coordinated changes suggest that the torque variability was mainly due to the variability of the common drive to the muscles serving 2 joints, although this statement needs to be supported by direct studies of muscle activation in the future.     

An Eastern Orthodox Theological Basis for Interplanetary Environmental Ethics

As a result of our technological advances in space exploration, human enterprise is no longer limited to the confines of planet Earth. Although several philosophical approaches to environmental ethics have already been advocated for human encounters with other planets such as Mars, it may be argued that various religious worldviews will significantly influence these suggested value systems. In this article, we present an Eastern Orthodox Christian interpretation of Creation and explore the theological meaning of the human vocation as Priests of Creation. An appropriate application of these two principles provides a theological basis for an interplanetary eco-praxis.     

Mental Health Services in Kentucky Nursing Homes: A Survey of Administrators

National surveys have shown that mental health problems are prevalent in long-term care and suggest that these settings are largely underserved by mental health services. Nursing home administrators are gatekeepers for mental health services in nursing homes. Administrators of Kentucky nursing homes were surveyed regarding their perceptions of mental health problems, current and future services use, satisfaction with services, and need for consultation. The response rate was 24%. Administrators appeared to underestimate mental health problems among residents. Most facilities were using at least one type of mental health service, but fewer residents received services than would be expected given the problem prevalence. Psychological services were underused, in spite of the fact that behavior management stood out as a major need. Psychiatry was more frequently used, but with less satisfaction. Results indicate significant financial and logistical barriers to mental health services. Future work is needed on developing, assessing, and disseminating models of effective service provision to long-term care.     

Extending Standard Models of ZFC to Models of Nonstandard Set Theories

We study those models of ZFCwhich are embeddable, as the class of all standard sets, in a model of internal set theory >ISTor models of some other nonstandard set theories. This revised version was published online in June 2006 with corrections to the Cover Date.