In the winter of 2002, I relocated my family from our small ranch in the southeast corner of Wyoming to the south Denver suburbs. For my hobby, it was a difficult relocation as I had to give up my antenna farm made of numerous towers, antennas and, in particular, my 4 square arrays for 40 and 80 meters. These arrays were used primarily for my own science studies regarding short and long path DX...

This paper focuses on modeling the gait characteristics of a quadrupedal gallop. There have been a number of studies of the mechanics of the stance phase in which a foot is in contact with the ground. We seek to put these studies in the context of the stride, or overall motion cycle. The model used is theoretical, and is kept simple in the interest of transparency. It is compared to empirical d...

For many industrial tasks (push, pull, lift, carry, etc.), restrictions on grip locations and visibility constrain the hand and head positions and help to define feasible postures. In contrast, foot locations are often minimally constrained and an ergonomics analyst can choose several different stances in selecting a posture to analyze. Also, because stance can be a critical determinant of a bi...

The effect of skis on the force-time characteristics of the simulated ski jumping takeoff was examined in a wind tunnel. Takeoff forces were recorded with a force plate installed under the tunnel floor. Signals from the front and rear parts of the force plate were collected separately to examine the anteroposterior balance of the jumpers during the takeoff. Two ski jumpers performed simulated t...

Cell migration triggered by pseudopodia (or "false feet") is the most used method of locomotion. A 3D finite element model of a cell migrating over a 2D substrate is proposed, with a particular focus on the mechanical aspects of the biological phenomenon. The decomposition of the deformation gradient is used to reproduce the cyclic phases of protrusion and contraction of the cell, which are tig...

Footprints of the rhea (Rhea ameriama) are identical in several diagnostic features to tridactyl footprints of the Mesozoic Era attributed to theropod dinosaurs. Of particular interest,'(i) the rhea's feet are placed very close to its body midline as it walks, so that it virtually places one foot in front of the other; (ii) its middle toe (digit III), the central weight-bearing axis, is directe...

OBJECTIVE Verify weight-bearing on the feet in a sitting position during pointing in different directions with 1 or both upper limbs. DESIGN Comparative study. SUBJECTS Fifteen subjects with post-stroke hemiparesis with good to very good motor recovery and 13 healthy subjects participated in the study. METHODS The subjects were seated on a chair with each foot resting on a force plate. Th...

BACKGROUND It has not yet been shown that ossification of ungular cartilages (OUC) is a pathological condition. Beside heredity, factors such as sex, age, repeated concussion, local trauma, hoof and body size have been suggested as contributing factors for OUC development. By comparing radiographs of front hooves from cold-blooded trotters with different age we wanted to evaluate when developme...

The loss of plasma from dilated and injured capillaries may be disastrous in several ways. One of these, the systemic effect, is so widely appreciated as to have dominated physiological thinking in the treatment of burns almost to the exclusion of other principles very vital to efficient v therapy. There can be no doubt that reduction in plasma volume by leakage from abnormal capillaries in bur...

We describe a small-molecule "walker" that uses enzyme catalysis to discriminate between the relative positions of its "feet" on a track and thereby move with net directionality. The bipedal walker has identical carboxylic acid feet, and "steps" along an isotactic hydroxyl-group-derivatized polyether track by the formation/breakage of ester linkages. Lipase AS catalyzes the selective hydrolysis...