Three-month-old mulberry (Morus alba L.) cultivars (drought tolerant S13 and drought sensitive S54) were subjected to water stress for 15 d. Water stress decreased the leaf water potential, net photosynthetic rate (PN), and stomatal conductance (gs) in both the cultivars. However, the magnitude of decline was comparatively greater in the sensitive cultivar (S54). Intercellular CO2 concentration (Ci) was unaltered during mild stress, but significantly increased at severe stress in both cultivars. The photosystem 2 activity significantly declined only at a severe stress in both cultivars. The Ci/gs ratio representing the mesophyll efficiency was greater in the tolerant cultivar S13. Involvement of stomatal and/or non-stomatal components in declining PN depended on the severity and duration of stress. However, the degree of non-stomatal limitations was relatively less in the drought tolerant cultivar. and S. Ramanjulu, N. Sreenivasulu, C. Sudhakar.
The aim of the study was to assess the possibility of using the empirical formulas to determine the roughness coefficient in gravel-bed streams, the bed slopes of which range from 0.006 to 0.047. Another aim was to determine the impact of taking into account the conditions of non-uniform flow on the application of these formulas and to develop the correlation relationships between the roughness coefficient and water surface slope and also between the roughness coefficient and friction slope in order to estimate the roughness coefficient n in gravel-bed streams. The studies were conducted in eight measuring sections of streams located in the Kraków-Częstochowa Upland, southern Poland. The roughness coefficient n0 for these sections was calculated from the transformed Bernoulli equation based on the results of surveys and hydrometric measurements. The values of n0 were compared with the calculation results obtained from fourteen empirical formulas presenting the roughness coefficient as a function of slope. The Lacey, Riggs, Bray and Sauer formulas were found to provide an approximate estimate of the n value, while the best roughness coefficient estimation results were obtained using the Riggs formula. It was also found that taking into account the non-uniform flow and using the friction slope in the formulas instead of the bed slope or water surface slope did not improve the estimated values of the roughness coefficient using the tested formulas. It was shown that the lack of differences in the RMSE and MAE error values calculated for the developed correlation equations between the roughness coefficient and the friction slope or with the water surface slope also indicate no influence of the assumed friction slope or water surface slope on the value of the estimated roughness coefficient.
In order to evaluate effect of weedy rice on the photosynthesis and grain filling of cultivated rice, cultivated rice ‘Nanjing 44‘ was planted in the field under different densities of weedy rice ‘JS-Y1‘ for two years. The results showed that net photosynthetic rate (PN), net assimilation rate, grain filling rate, and the grain yield of cultivated rice all decreased with increasing weedy rice density. Furthermore, yield component analysis revealed that increasing weedy rice density had the most significant effect on the percentage of filled grains and the number of rice panicles. The correlation analyses indicated that the yield of cultivated rice was highly correlated with the net photosynthetic rate and the net assimilation rate. Our results illustrated that high density of weedy rice might cause yield losses in cultivated rice by inhibition of photosynthesis and grain filling., X. M. Xu, G. Li, Y. Su, X. L. Wang., and Obsahuje bibliografii
The aim of this study was to assess the influence of regular daily consumption of white wine on oxidative stress and cardiovascular risk markers. Forty-two healthy male volunteers consumed 375 ml of white wine daily. Each participant provided three venous blood samples (before wine consumption, following the wine consumption period and again a month later). Levels of superoxide dismutase, glutathione peroxidase, reduced glutathione, total antioxidant capacity, total cholesterol, HDL-cholesterol, apolipoprotein A I, apolipoprotein B, triglycerides, paraoxonase 1, C-reactive protein, homocysteine, thiobarbituric acid reactive substances (TBARS) and advanced oxidation protein products (AOPP) were measured. Immediately following the month of white wine consumption there was a significant increase in HDL-cholesterol (p<0.0001), paraoxonase 1 (p<0.001), glutathione peroxidase (p<0.001) and reduced glutathione (p<0.01) levels, a decrease in superoxide dismutase activities (p<0.0001), and a decrease in oxidation protein products (p<0.001) and TBARS (p<0.05) concentrations. However, there was also a clear increase in homocysteine (p<0.0001) after a month of white wine consumption. The results of our non-placebo controlled trial suggest that regular daily white wine consumption is associated not only with both antioxidative and antiatherogenic effects but also with a potentially proatherogenic increase of homocysteine concentrations. and D. Rajdl, J. Racek, L. Trefil, K. Siala.
The study was performed to test the hypothesis that winter food deficit can act to reduce a water vole, Arvicola terrestris, population in Western Siberia. During 12 years, a total of 139 wintering burrows were examined at different phases of population cycles. The size of food stores was found to be greater during increases of the population compared to that at the peak and the decline. Comparison of the mass of stores in burrows and the daily consumption of natural foods under controlled conditions shows that only a small fraction of individuals have sufficient food supply for safe wintering. Females have smaller stores compared to males, and this is possibly responsible for their higher winter mortality. The size of food stores in October affects both winter change in body mass as defined by difference between average mass in samples of animals captured in October and in May of the next year and winter survival determined as a ratio between population densities in May and October. The deficiency of food during winter is likely to be a strong factor affecting body mass change, density, sexual and age structures, and reproductive potential in the water vole population in Western Siberia.
Time delay in the mediation of ventilation (VE) by arterial CO2 pressure (PaCO2) was studied during recovery from short impulse-like exercises with different work loads of recovery. Subjects performed two tests including 10-s impulse like exercise with work load of 200 watts and 15-min recovery with 25 watts in test one and 50 watts in test two. V . E, end tidal CO2 pressure (PETCO2) and heart rate (HR) were measured continuously during rest, warming up, exercise and recovery. PaCO2 was estimated from PETCO2 and tidal volume (VT). Results showed that predicted arterial CO2 pressure (PaCO2 pre) increased during recovery in both tests. In both tests, VE increased and peaked at the end of exercise. VE decreased in the first few seconds of recovery but started to increase again. The highest correlation coefficient between PaCO2 pre and V . E was obtained in the time delay of 7 s (r=0.854) in test one and in time delays of 6 s (r=0.451) and 31 s (r=0.567) in test two. HR was significantly higher in test two than in test one. These results indicate that PaCO2 pre drives VE with a time delay and that higher work intensity induces a shorter time delay., R. Afroundeh, T. Arimitsu, R. Yamanaka, C. S. Lian, K. Shirakawa, T. Yunoki, T. Yano., and Obsahuje bibliografii
The effect of p-hydroxybenzoic acid (HBA), syringic acid (SYA) and yeast culture (YS) on rumen fermentation in vitro has been investigated. Meadow hay was used as a substrate and rumen fluid as an inocula. The yeast culture Levucel contained 5x10s yeast cells Saccharomyces cerevisiae per 1 g of dry matter and was used in the amount of 0.5 g/1 of the medium. The following combinations of additives were used: hay without additive, hay + YS, hay with 1, 5 or 10 mmol HBA or SYA, and hay + YS with 1, 5 or 10 mmol HBA or SYA. The test tubes were incubated for 96 hours at 39 °C. The results showed that 1 mmol HBA had a significant effect on yeast efficacy. This was manifested in the increased degradability of hay dry matter (P<0.05) and enhanced total gas production (P<0.05). SYA in the same amount combined with yeast had a similar effect on gas production (P<0.05), but hay dry matter degradability was not affected. The results showed a slight effect of phenolic acids and yeast culture on hay rumen fermentation in vitro.
Cauliflower (Brassica oleracea L. var. botrytis) plants subjected to Zn defíciency showed decreased leaf water potential and transpiration rate, and increased leaf thickness, and accumulation of sugars and starch. Zn-deficient leaves also showed decreased photosynthetic rates (P^) and compensation irradiance and increased apparent quantum efficiency. Decrease in leaf chlorophyll (Chl) content due to Zn defíciency, though signifícant on fresh mass unit was insignifícant on leaf area unit. Decreased was not attributable to the effects of Zn defíciency on Chl content upto 51 d of treatment. Zn-defícient leaves showed an insignifícant decrease in photosynthetic O2 evolution at saturating irradiance and CO2 supply; signifícant decreases in P^, stomatal conductance and intercellular CO2 concentration when the leaves were supplied with CO2 at atmospheric concentration suggest that stomatal limitation contributes signifícantly towards decreased P^ in Zn-defícient leaves.
Effect of three Zn2+ concentrations, i.e. 0.075 (cl), 7.50 (c2) and 37.5 (c3) jiM, on rice seedlings was studied at three stages, i.e. 1, 14 and 21 d after transplantation. Typical deficiency symptoms were observed in both solution and sand cultures of cl and c2, but the effects were more pronounced in the solution culture. The c3 concentration was toxic. There was marked reduction in growth, chlorophyll (Chl) contents (particularly Chl b), Hill reaction activity, photophosphorylation rate (particularly non-cyclic photophosphorylation), thylakoid phosphorylation, and i'‘C02-fixation at the cl concentration. However, a similar reduction was also observed in thylakoid phosphorylation at the c3 concentration. Hence the optimum zinc concentration in the nutrient medium lied between c2 and c3 Zn2+. By regression the theoretical optimum Zn concentration was calculated as 19.20 pM (1.28 mg kg'i) Zn2+. Partitioning of ^'^C-photosynthates indicated reduced allocation to sugar and starch fractions and increased fřee amino acids concentration at the cl concentration and vice-versa at c2 and c3.