BACKGROUND Sacral bone fractures after direct traumas such as gunshot wounds and blunt sacral traumas are rarely, whereas those occurring after indirect traumas with vertical shear mechanisms ( car accidents or falls) are more frequently seen. METHODS A cadaver sacrum was modelled 3-dimensionally using finite element software. Left sacroiliac joint was modeled to simulate a 75- kg man falling...

This paper presents a series of global three dimensional accretion disk simulations carried out in the cylindrical limit in which the vertical component of the gravitational field is neglected. The simulations use a cylindrical pseudo-Newtonian potential, ∝ 1/(R −Rg), to model the main dynamical properties of the Schwarzschild metric. The radial grid domain runs out to 60 Rg to minimize the inf...

The purpose of the present study was to ascertain whether increase in step frequency at a given velocity during running reduces the lower extremity loading variables, which is associated with tibial stress fracture in runner. We hypothesized that the lower extremity loading variables at a given speed would be minimized at around +15% f step. 10 male subjects were asked to run at 2.5 m/s on a tr...

BACKGROUND Loads acting on scoliotic spines are thought to be asymmetric and involved in progression of the scoliotic deformity; abnormal loading patterns lead to changes in bone and disc cell activity and hence to vertebral body and disc wedging. At present however there are no direct measurements of intradiscal stresses or pressures in scoliotic spines. The aim of this study was to obtain qua...

OBJECTIVES The purpose of this study was to investigate the effect of differences in the resin-cement elastic modulus on stress-transmission to ceramic or resin-based composite inlay-restored Class II MOD cavities during vertical occlusal loading. METHODS Three finite-element (FE) models of Class II MOD cavity restorations in an upper premolar were produced. Model A represented a glass-cerami...

[1] The temporal and spatial variability of vertical salt flux in the Fraser River Estuary, British Columbia, was investigated observationally, using several different direct and indirect indicators of buoyancy flux. Data were collected from the estuary using shipboard instrumentation, primarily an acoustic Doppler current profiler and a towed conductivitytemperature-depth unit. Direct estimate...

We perform numerical simulations of magneto-rotational instability in a local patch of accretion disk in which radiation pressure exceeds gas pressure. Such conditions may occur in the central regions of disks surrounding compact objects in active galactic nuclei and Galactic X-ray sources. We assume axisymmetry, and neglect vertical stratification. The growth rates of the instability on initia...

We examine the mean zonal momentum balance in the tropical mid-Pacific using a year of acoustic Doppler current profiler velocities and conductivitytemperature-depth profiler densities from the Hawaii-to-Tahiti Shuttle Experiment. All significant contributions from the mean, annual cycle, and higher-frequency flow fields are determined with the exception of the vertical stresses. We find that e...