Posteroanterior stiffness of the lumbar spine is influenced by factors, including trunk muscle activity and intra-abdominal pressure (IAP). Because these factors vary with breathing, this study investigated whether stiffness is modulated in a cyclical manner with respiration. A further aim was to investigate the relationship between stiffness and IAP or abdominal and paraspinal muscle activity....

Paper is by far the dominant component in speaker cones. It is hard to beat cellulose paper for its mix of strength, lightness, stiffness, damping, and sound quality. Yet its strength drops off when it gets wet. The characteristics of paper cones shift due to humidity and tearing results from stress and punctures. I think almost everything has been used for speaker diaphragms, including acetic ...

In this paper, a novel design of a biology-inspired directional microphone is presented. This microphone consists of two clamped circular diaphragms, which are mechanically coupled by a connecting bridge that is pivoted at its center. A mechanics based model is constructed to determine the response of the proposed directional microphone to sound incident from an arbitrary direction. The simulat...

Michael G. Oliva, Ph.D. Professor Department of Civil and Environmental Engineering University of Wisconsin–Madison Madison, Wisconsin The in-plane fl exibility of untopped precast concrete double-tee diaphragms is often ignored in current design practice. The performance of parking structures during earthquakes and subsequent research studies have shown, however, that in-plane fl exibility of ...

Ventilatory insufficiency remains the leading cause of death and late stage morbidity in Duchenne muscular dystrophy (DMD). To address critical gaps in our knowledge of the pathobiology of respiratory functional decline, we used an integrative approach to study respiratory mechanics in a translational model of DMD. In studies of individual dogs with the Golden Retriever muscular dystrophy (GRMD...

We investigated the hypothesis that diaphragm compliance was abnormal in cardiomyopathic Syrian hamsters (CSH), an experimental model of myopathy. The passive elastic properties of isolated diaphragm muscles were analyzed at both the muscle and sarcomere levels. We used the following passive exponential relationship between stress (sigma) and strain (epsilon): sigma = (Eo/beta) (ebetaepsilon - ...