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...

[Purpose] We examined cardiorespiratory and metabolic changes across the 1st (G1), 2nd (G2) and 3rd (G3) trimesters in pregnant women. [Subjects and Methods] Forty-two healthy, active, non-smoking, pregnant women participated in this study. They were divided into G1, G2 and G3 groups depending on their mean gestational ages at the time of testing which were 10.5 ±2.9, 19.2 ±3.4, and 33.3 ±2.4 w...

Marsupials are born with immature lungs when compared to eutherian mammals and rely, to various extents, on cutaneous gas exchange in order to meet metabolic requirements. Indeed, the fat-tailed dunnart is born with lungs in the canalicular stage of development and relies almost entirely on the skin for gas exchange at birth; consequently undergoing the majority of lung development in air. Plan...

The impact ofwheat stem sawßy,Cephus cinctusNorton (Hymenoptera: Cephidae), on the photosynthetic capacity and primary metabolism of wheat, Triticum aestivum L., was evaluated in three different environments: environmental growth chamber, greenhouse, and Þeld. C. cinctus elicited different photosynthetic responses in different environments. Wheat gas exchange parameters, such as photosynthesis,...

Respiratory sinus arrhythmia (RSA) may be associated with improved efficiency of pulmonary gas exchange by matching ventilation to perfusion within each respiratory cycle. Respiration rate, tidal volume, minute ventilation (.VE), exhaled carbon dioxide (.VCO(2)), oxygen consumption (.VO(2)), and heart rate were measured in 10 healthy human volunteers during paced breathing to test the hypothesi...

grafting of cucurbitaceae species to some rootstocks seems to be especially beneficial for the nitrogen nutrition of these plants. moreover, melons (cucumis melo l.) have been considered among those plants that could benefit from the addition of silicon (si) in the nutrient solution (ns). thus, two experiments were carried out in the following order: (i) it was investigated how grafting affects...

this study investigated the variation between two sugar beet (beta vulgaris l.) cultivars with respect to growth parameters and photosynthetic rates of individual attached leaves during salinization. sugar beet plants grown in sand culture were gradually exposed to different levels of salinity (0, 50, 150 , 250, and 350 mm, nacl+cacl2 in 5:1 ratio). salt concentrations significantly decreased a...

Lung volume reduction surgery (LVRS) improves lung function, respiratory symptoms, and exercise tolerance in selected patients with chronic obstructive pulmonary disease, who have heterogeneous emphysema. However, the reported effects of LVRS on gas exchange are variable, even when lung function is improved. To clarify how LVRS affects gas exchange in chronic obstructive pulmonary disease, 23 p...

BACKGROUND Etorphine, a potent opioid agonist, causes pulmonary hypertension and respiratory depression. Whether etorphine-induced pulmonary hypertension negatively influences pulmonary gas exchange and exacerbates the effects of ventilator depression and the resultant hypoxemia is unknown. To determine if these effects occurred we instrumented twelve goats with peripheral and pulmonary arteria...

OBJECTIVE To describe the kinetics of metabolic gas exchange at the onset and offset of low level, constant work exercise in patients with chronic heart failure. SETTING Tertiary referral centre for cardiology. PATIENTS 10 patients with chronic heart failure and 10 age matched controls. METHODS Each subject undertook maximum incremental exercise testing with metabolic gas exchange measure...