BACKGROUND Neurulation is driven by apical constriction of actomyosin cytoskeleton resulting in conversion of the primitive lumen into the central canal in a mechanism driven by F-actin constriction, cell overcrowding and buildup of axonal tracts. The roof plate of the neural tube acts as the dorsal morphogenetic center and boundary preventing midline crossing by neural cells and axons. METHO...

During spinal cord development, commissural neurons extend their axons ventrally, away from the roof plate. The roof plate is the source of a diffusible repellent that orients commissural axons in vitro and, thus, may regulate the trajectory of commissural axons in vivo. Of three Bmps expressed in the roof plate, BMP7, but not BMP6 or GDF7, mimics the roof plate activity in vitro. We show here ...

The Tashan coal mine is selected as a case study to determine the deformation and damage mechanisms of lower roadway in close-range residual pillar area. Roof drilling peephole technology applied detect roof surrounding rock. A boundary invisibility equation derived for plastic zone circular hole based on theory butterfly non-uniform stress field which principal occurs at an arbitrary angle ver...

Collapse of roof could cause severe economic loss and poses safety risk to residents in the building. This paper presents a nonlinear dynamic analysis of steel framed roof structures with force limiting devices under combined static and transient wind loading. Two types of force limiting devices – one with selfcentering behavior and the other exhibiting bilinear-like hysteresis are examined for...

This study determined that knee extension (range, -30 degrees to 2 degrees) and the slope of the intercondylar roof (range, 26 degrees to 46 degrees) vary widely between knees in both men and women. We found a weak relationship between knee extension and the slope of the intercondylar roof (r2 = 0.207); therefore, roof angle cannot be predicted by clinically measuring knee extension. CLINICAL R...

Contact between an anterior cruciate ligament graft and the intercondylar roof has been termed roof impingement. Grafts with impingement sustain permanent damage, and if the injury is extensive enough, then the graft may fail, causing recurrent instability. This study evaluated two mechanical factors that could be responsible for the graft injury associated with roof impingement: an increase in...

Gable roof buildings are widely used in industrial buildings. Based on wind tunnel tests with rigid models, wind pressure distributions on gable roof buildings with different aspect ratios were measured simultaneously. Some characteristics of the measured wind pressure field on the surfaces of the models were analyzed, including mean wind pressure, fluctuating wind pressure, peak negative wind ...

OBJECTIVE The present study aimed to evaluate a new method for validation of complete linear block at the left atrial (LA) roof. BACKGROUND Linear lesions at the LA roof have been reported to improve the success rate of catheter ablation of atrial fibrillation (AF). METHODS Complete linear block at the LA roof was evaluated in 31 patients after complete isolation of pulmonary vein antrum (P...

The paper proposes a novel approach for a scale-dependent geometric simplification of 3D building models that are an integral part of virtual cities. In contrast to real-time photorealistic visualisations, map-like presentations emphasize the specific cartographic properties of objects. For buildings objects, such properties are e.g. the parallel and right-angled arrangements of facade walls an...

This paper presents an approach to creating a polyhedral model of building roof from LiDAR point clouds using clustering techniques. A building point cloud is first separated into planar and breakline sections using the eigenvalues of the covariance matrix in a small neighbourhood. The planar components from the point cloud are then grouped into small patches containing 6-8 points and their nor...