Isospectral pairs of metrics on balls, spheres, and other manifolds with different local geometries

The first isospectral pairs of metrics are constructed on balls and spheres. This long standing problem, concerning the existence of such pairs, has been solved by a new method called "Anticommutator Technique." Among the wide range of such pairs, the most striking examples are provided on (4k-1)-dimensional spheres, where k > 2. One of these metrics is homogeneous (since it is the metric on the geodesic sphere of a 2-point homogeneous space), while the other is locally inhomogeneous. These examples demonstrate the surprising fact that no information about the isometries is encoded in the spectrum of Laplacian acting on functions. In other words, "The group of isometries, even the local homogeneity property, is lost to the "Non-Audible" in the debate of "Audible versus Non-Audible Geometry"."Comment: 43 pages. After retrieving source, read README file or type tex whole to typeset (in Unix

Motion Capture System for Finger Movement Measurement in Parkinson Disease

Parkinson’s disease (PD) is a chronic neurodegenerative disorder that affects almost 1% of the population in the age group above 60 years. The key symptom in PD is the restriction of mobility. The progress of PD is typically documented using the Unified Parkinson’s Disease Rating Scale (UPDRS), which includes a finger-tapping test. We created a measurement tool and a methodology for the objective measurement of the finger-tapping test. We built a contactless three-dimensional (3D) capture system using two cameras and light-passive (wireless) reflexive markers. We proposed and implemented an algorithm for extracting, matching, and tracing markers. The system provides the 3D position of spherical or hemispherical markers in real time. The system’s functionality was verified with the commercial motion capture system OptiTrack. Our motion capture system is easy to use, saves space, is transportable, and needs only a personal computer for data processing—the ideal solution for an outpatient clinic. Its features were successfully tested on 22 patients with PD and 22 healthy control subjects

Cumulative trauma, emotion reactivity and salivary cytokine response following acute stress among healthy women.

This study furthers understanding of how trauma exposure may be connected to the development and maintenance of poor health by focusing on cytokines, tightly regulated proteins of the immune system. Cytokine responses to acute stress have been associated with the onset of poorer mental health in physically healthy women. The present study examined how two factors recently associated with cytokine reactivity –cumulative trauma and emotion reactivity– are associated with salivary cytokine reactivity among healthy women. Seventy-one women, screened to be physically and mentally healthy, completed a laboratory acute stress paradigm and self-report measures of state emotion and trauma exposure. Participants were primarily White/European-American, with a mean age of 23. The majority of participants reported experiencing at least one potentially traumatic event, with a mean of five. Saliva samples were taken 10 min before (i.e., baseline) and 35 min after the onset of a 10-min stressor, a modified version of the Trier Social Stress Test. State negative and positive emotion were measured at baseline and after the stressor. Cumulative trauma was not associated with changes in IL-1β, IL-10 or IL1β/IL10 or changes in emotion. Declines in positive emotion correlated with increases in IL-1β. Changes in both negative and positive emotion together were not related to cytokine responses. Given that this sample was healthy, despite high levels of trauma exposure, this may represent a resilient sample. Recommendations for future research are discussed, including measurement of trauma and of emotion. This study adds to the small but growing literature examining how trauma may connect to cytokines, and ultimately, the development and maintenance of poor health