Effects of normoxia and hyperoxia on the rate of fatigue development in human respiratory muscles under conditions of intensive resistive load.

We evaluated the rate of fatigue development in the inspiratory muscles of healthy trained individuals during graded bicycle exercise and high resistive resistance to breath under conditions of normoxia and hyperoxia. Fatigue of the respiratory muscles was assessed by tension-time index (TT(m)=P(m)I/P(m)I(maxx)T(I)/T(T)), by the dynamics of changes in the ratio of respiratory volume to inspiratory muscles force, and by ratio of the mean amplitudes of electrical activity in high and low frequency ranges. It was found that the limit of extreme working capacity in humans during heavy resistive load is related to fatigue of the inspiratory muscles developing with the same rate under conditions of normoxia or hyperoxia.

[Hygienic problems of industrial animal husbandry]. / Gigienicheskie problemy promyshlennogo zhivotnovodstva.

Basic unfavourable factors of working conditions in modern livestock enterprises as well as industrial livestock complexes effects on environmental state are formulated. The relationships between the main subsystems such as forage production, livestock breeding proper, agriproduct processing, working and social infrastructures of the ++agro-industrial complex are established. It is shown that general and occupational morbidity in cattle-breeders is conditioned by the character of production processes, the technology of manure collection, storing, processing and utilization. With livestock enterprises, the borders of their adverse effects spreading in the environment, the rated formulae as well as health improvement measures are validated.