abstract three pear genotypes (nazkeh, lasoreh and qevilah), grown in 2l containers, were studied under four irrigation regimes in order to evaluate the leaf relative water content (rwc), photosynthesis, leaf gas exchanges and plant dry weight induced by water stress. control treatment everyday was irrigation. irrigation was practiced when soil water potential reached at -0.4, -0.8, and -1.2 mp...

With readily available techniques, cardiopulmonary exercise testing permits noninvasive measurement of such parameters as heart rate, cardiac output, oxygen saturation, ventilation, and gas exchange to bring out abnormalities which are either underestimated or not detectable at rest. These parameters may be used to characterize a patient's primary limitation of exercise tolerance as either card...

One-dimensional multilayer biosphere-atmosphere models (e.g., CANVEG) describe ecosystem carbon dioxide (CO2) and water vapor (H2O) fluxes well when cold temperatures or the hydrologic state of the ecosystem do not induce stomatal closure. To investigate the CANVEG model framework under such conditions, CO2, H2O, and sensible heat fluxes were measured with eddy-covariance methods together with ...

• In studies of gas exchange between the lung and the pulmonary circulation it is generally assumed that the principal exchange takes place at the level of the pulmonary capillaries. The work presented here shows that some gaseous exchange can occur as well between the lung and vessels of macroscopic size. Hydrogen gas when administered to a subject by inhalation can be detected in the pulmonar...