by muscles in life, in isometric conditions, were calculated by means of several anatomical parameters. Ultimate tensile stresses were measured with an Instron testing machine. Using both of these stresses, the safetyfactors of some tendons were calcu- lated. These safetyfactors agree with the few
The cohesion-tension theory of water transport states that hydrogen bonds hold water molecules together and that they are pulled through the xylem under tension. This tension could cause transport failure in at least two ways: collapse of the conduit walls (implosion), or rupture of the water column through air-seeding. The objective of this research was to elucidate the functional significance of variations in tracheid anatomical features, earlywood to latewood ratios and wood densities with position in young and old Douglas-fir and ponderosa pine trees in terms of their consequences for the safety factors for tracheid implosion and air-seeding. For both species, wood density increased linearly with percent latewood for root, trunk and branch samples. However, the relationships between anatomy and hydraulic function in trunks differed from those in roots and branches. In roots and branches increased hydraulic efficiency was achieved at the cost of increased vulnerability to air-seeding. Mature wood of trunks had earlywood with wide tracheids that optimized water transport and had a high percentage of latewood that optimized structural support. Juvenile wood had higher resistance to air-seeding and cell wall implosion. The two safety factors followed similar axial trends from roots to terminal branches and were similar for both species studied and between juvenile and mature wood.
. Kirkpatrick defined a safetyfactor (SF) as the ratio between the breaking stress of wing bone material and the estimated stress, using a value of ultimate tensile stress of bird wing bone of 125 MPa. The largest bird examined (a 1.5 kg cormorant) had a SF of 5 in gliding flight and 1.7 in hovering flight
taper of the tibia ensured fairly uniform stresses all along its shaft. The muscles and bones seem to have been well matched to cooperate in the jump. However, we ought not, perhaps, to expect equal stresses in all bones: CURREY (1984) argued that more distal leg bones should have lower safetyfactors
safetyfactor when operating. These features are ensuring the success of the product: Mikroland Innovations exports 37% of its turnover, particularly to Europe, Turkey, Iran, India and South Africa. The involvement of the Staubli group (2400 employees, FFr 3 million turnover) in the medical sector is
concern...4 the inquiry "'adjusts to the safetyfactor'"—"'[t]he greater the safetyfactor, measured by the likelihood of harm and the probable severity of that harm in case of an accident, the more strin- gent may be the job qualifications,"'.... Second, the employer must show either that all or
discrimination must be reasonably necessary to the essence of his business-here, the safe transporta- tion of bus passengers from one point to another. The greater the safetyfactor, measured by the likelihood of harm and the probable severity of that harm in case of an accident, the more stringent may be the
TTX- sensitive sodium channels? In contrast to TTX-resistant sodium channels, the TTX- sensitive ones are activated at more negative potentials: the corresponding ‘50% activation values’ are − 15 and − 26 mV (Roy and Narahashi, 1992). Thus, the conduction safetyfactor should be larger for an axon
bones of moas (Dinornithes) and other birds. J. Zool., Lond. 200: 215-231.
225 BIEWENER, A.A., 1982. Bone strength in small mammals and bipedal birds: do safetyfactors change with body size? J. exp. Biol. 98: 289-301. BIKNEVICIUS, A.R., 1993. Biomechanical scaling of limb bones and differential
0.5 mN. Next, we measured the adhesion forces of test structures to be up to 100 ¹ N . We arbitrarily multiplied the adhesion forces by a safetyfactor of ten to arrive at the estimated force of 1 mN. Thus, each actuator should provide 1.5 mN (weight C adhesion) of force. The power dissipated in