N. I. Vavilov-the man and his work

A brief sketch is presented of Vavilov's career, his main contributions to science and personal qualities. The imporatnce of his work in genetics, agro-ecology, plant breeding, the experimental taxonomy of crop plants and genetic resources conservation is also emphasized.     

Ability of man to detect increases in his breathing.

The ability of four normal subjects to detect increases in their ventilation was studied at rest and at two levels of exercise using a raised inspired Pco2 to further increase ventilation. Subjects signaled when the increase in ventilation was recognized. The average tidal volume (VT) at rest was 520 ml with a frequency of 14; these values increased to an average of 3,300 ml and 21 at the highest work load. There was no significant change in frequency with CO2. Detection occurred when the tidal volume increased by 700 ml (varying 550-890 between subjects but constant for any one subject at the three levels of ventilation.) Thus the appreciation of increase is proportionately more sensitive at higher levels of ventilation. Experiments in which the ventilation was increased by hypoxia or by following a visual demand, and observations of other sensations (oral, cerebral) indicate that the increase in vetilation is recognized through increased breathing rather than awareness of ventilatory stimuli.     

Bronchiolitis obliterans in a man who used his wood-burning stove to burn synthetic construction materials

Many people heat their homes with wood-burning stoves. However, toxic fire effluent can escape from old or improperly operated stoves. The authors describe a case in which bronchiolitis obliterans developed in a man within hours after he burned synthetic construction materials in his wood-burning stove. Certain factors, such as careless or improper use of the stove, the size of the room, the lack of open-air ventilation and the composition of the materials burned, strongly point to inhalation of the fire effluent as the cause.