Safety measures for conducting exercise oxygen consumption, VO2, tests in developing countries.

Measurements of rate of oxygen consumption (VO2) recorded during controlled exercise is used to assess cardiovascular health in test individuals. In low- or middle-income countries, where Mycobacterium tuberculosis is common and older VO2 systems are in use, three specific preventative measures should be in place to prevent the transmission of tuberculosis. These include: (1) disinfecting reusable plastic masks and rubber tubing with bleach solution; (2) limiting maximum exposure of test individuals to Cl2 gas to <1-3 ppm for a duration of ≤15 min to prevent respiratory distress; and (3) carefully inspecting for degradation of plastic VO2 masks and rubber tubing repeatedly disinfected with bleach and replace these at the first signs of deterioration.

Minimum cost of transport in Asian elephants: do we really need a bigger elephant?

Body mass is the primary determinant of an animal's energy requirements. At their optimum walking speed, large animals have lower mass-specific energy requirements for locomotion than small ones. In animals ranging in size from 0.8 g (roach) to 260 kg (zebu steer), the minimum cost of transport (COT(min)) decreases with increasing body size roughly as COT(min)∝body mass (M(b))(-0.316±0.023) (95% CI). Typically, the variation of COT(min) with body mass is weaker at the intraspecific level as a result of physiological and geometric similarity within closely related species. The interspecific relationship estimates that an adult elephant, with twice the body mass of a mid-sized elephant, should be able to move its body approximately 23% cheaper than the smaller elephant. We sought to determine whether adult Asian and sub-adult African elephants follow a single quasi-intraspecific relationship, and extend the interspecific relationship between COT(min) and body mass to 12-fold larger animals. Physiological and possibly geometric similarity between adult Asian elephants and sub-adult African elephants caused body mass to have a no effect on COT(min) (COT(min)∝M(b)(0.007±0.455)). The COT(min) in elephants occurred at walking speeds between 1.3 and ∼1.5 m s(-1), and at Froude numbers between 0.10 and 0.24. The addition of adult Asian elephants to the interspecific relationship resulted in COT(min)∝M (-0.277±0.046)(b). The quasi-intraspecific relationship between body mass and COT(min) among elephants caused the interspecific relationship to underestimate COT(min) in larger elephants.