Growth of the remnant embryonic kidney (the mesonephros), as expressed by wet weight, was more rapid in the chick embryos with experimentally induced unilateral renal agenes is compared to controls. The difference was significant between embryonic days 8-12, when the doubled weights of remnant kidneys were increased compared with the weights of paired control kidneys. The excessive growth of the mesonephros ceased on day 14, when the normal physiological regression of the embryonic kidney begins. In the definitive kidney, the metanephros, no significant differences in weights of the control vs. remnant metanephros were found on days 10-14. The characteristics of increased mesonephric growth were evaluated by determination of DNA/protein ratios in homogenates of the kidneys. Significant cellular hypertrophy was found in both the mesonephros and metanephros of the embryos with URA on day 10. Additionally, a non-significant cellular hyperplasia was also revealed in the remnant mesonephros on day 8. This gives evidence that the growth stimuli to the mesonephroi were probably strongest between days 8-10 and that they manifested in the remnant mesonephros only. and Obsahuje bibliografii a bibliografické odkazy
The parameters determine waves energy in shallow water zone that pronounces the crucial influence on abrasion of both natural and artificially paved banks. The effort to re-development of the relations was found as absolutely necessary for waves energy calculations. Substantial benefit of the work is found not only in enabling the use of computers while avoiding time-consuming and difficult application of diagrams, but namely in recent recognition that the calculation results showed a risk of underestimate the real impact of wind-induced waves. In some cases, the calculations respecting the above standard produce lower values of waves height and time-period and thus also lower values of wave energy., Tamara Spanilá and Karel Jahoda., and Obsahuje bibliografické odkazy
This paper reports the possibilities of using FTIR spectroscopy and simultaneous thermogravimetry and differential thermal analysis for examination of the structural order of four Czech kaolinite samples (Jimlikov, Sedlec, Olomucany and Unanov deposits) and one kaolinite standard KGa-1b from Georgia deposit obtained from the Source Clays Repository of The Clay Minerals Society (USA). FTIR spectroscopy was used for the classification of the degree of structural order of kaolinite samples by empirical (IR-E) and numerical (IR-N) classification. Differential thermal analysis was used for the determination of the kaolinite disorder degree according to decomposition peak temperature obtained from DTA curves. The resulting trend of decrease in orderliness is: KGA-1b (with the best orderliness) > Jimlikov > Sedlec > Olomucany > Unanov (with the worst orderliness)., Lenka Vaculíková, Eva Plevová, Silvie Vallová and Ivan Koutník., and Obsahuje bibliografii
In this paper, we study the admissibility of linear estimator of regression coefficient in linear model under the extended balanced loss function (EBLF). The sufficient and necessary condition for linear estimators to be admissible are obtained respectively in homogeneous and non-homogeneous classes. Furthermore, we show that admissible linear estimator under the EBLF is a convex combination of the admissible linear estimator under the sum of square residuals and quadratic loss function.
The character of soil cover in anthropogenically affected areas was determined on the basis of soil morphology, particle size distribution, soil chemical properties, soil organic matter properties and mineralogy of clay fraction. The degree of anthropogenic influence was variable in the individual soil profiles. This is probably the first time that data on hot-wate rextractable carbon distribution in soil profile were obtained from the territory of Prague., Anna Žigová, Martin Šťastný, Jana Krejčová and Pavel Hájek., and Obsahuje bibliografické odkazy
The major light-harvesting chlorophyll (Chl) a/b complexes of photosystem II (LHCIIb) play important roles in energy balance of thylakoid membrane. They harvest solar energy, transfer the energy to the reaction center under normal light condition and dissipate excess excitation energy under strong light condition. Many bamboo species could grow very fast even under extremely changing light conditions. In order to explain whether LHCIIb in bamboo contributes to this specific characteristic, the spectroscopic features, the capacity of forming homotrimers and structural stabilities of different isoforms (Lhcb1-3) were investigated. The apoproteins of the three isoforms of LHCIIb in bamboo are overexpressed in vitro and successfully refolded with thylakoid pigments. The sequences of Lhcb1 and Lhcb2 are similar and they are capable of forming homotrimer, while Lhcb3 lacks 10 residues in the N terminus and can not form the homotrimeric structure. The pigment stoichiometries, spectroscopic characteristics, thermo- and photostabilities of different reconstituted Lhcbs reveal that Lhcb3 differs strongly from Lhcb1 and Lhcb2. Lhcb3 possesses the lowest Qy transition energy and the highest thermostability. Lhcb2 is the most stable monomer under strong illumination among all the isoforms. These results suggest that in spite of small differences, different Lhcb isoforms in bamboo possess similar characteristics as those in other higher plants., Z. H. Jiang ... [et al.]., and Obsahuje bibliografii
In the present paper, fuzzy order relations on a real vector space are characterized by fuzzy cones. It is well-known that there is one-to-one correspondence between order relations, that a real vector space with the order relation is an ordered vector space, and pointed convex cones. We show that there is one-to-one correspondence between fuzzy order relations with some properties, which are fuzzification of the order relations, and fuzzy pointed convex cones, which are fuzzification of the pointed convex cones.
Halomicronema hongdechloris is a chlorophyll (Chl) f-producing cyanobacterium. Chl f biosynthesis is induced under far-red light, extending its photosynthetically active radiation range to 760 nm. In this study, PSI complexes were isolated and purified from H. hongdechloris, grown under white light (WL) and far-red light (FR), by a combination of density gradient ultracentrifugation and chromatographic separation. WL-PSI showed similar pigment composition as that of Synechocystis 6803, using Chl a in the reaction center. Both Chl a and f were detected in the FR-PSI, although Chl f was a minor component (~8% of total Chl). The
FR-PSI showed a maximal fluorescence emission peak of 750 nm at 77 K, which is red-shifted ~20 nm compared to the 730 nm recorded from the WL-PSI. The absorption peaks of P700 for WLPSI and FR-PSI were 699 nm and 702 nm, respectively. The function of Chl f in FR-PSI is discussed., Y. Li, N. Vella, M. Chen., and Obsahuje bibliografické odkazy
Net photosynthetic rate (PN), stomatal conductance (gs), intercellular CO2 concentration (Ci), transpiration rate (E), water use efficiency (WUE), and stomatal limitation (Ls) of Populus euphratica grown at different groundwater depths in the arid region were measured. gs of the trees with groundwater depth at 4.74 m (D4) and 5.82 m (D5) were lower and a little higher than that at 3.82 m (D3), respectively. Compared with C i and Ls of the D3 trees, Ci decreased and Ls increased at 4.74 m, however, Ci increased and Ls decreased at D5. Hence photosynthetic reduction of P. euphratica was attributed to either stomatal closure or non-stomatal factors depending on the groundwater depths in the plant locations. PN of the D3 trees was significantly higher than those at D4 or D5. The trees of D4 and D5 did not show a significant difference in their PN, indicating that there are mechanisms of P. euphratica tolerance to mild and moderate drought stress. and Y. P. Chen ... [et al.].
In comparison to cv. Torsdag, in leaves of low-productive Pisum sativum L. chlorophyll mutants the decrease in chlorophyll content was caused by the decrease in cell number per unit volume. Qualitative changes in activities of photosystem (PS) 1 in mutant M2004, and quantitative changes of PS1 and PS2 in mutants M2004 and M2014 and in hybrids were also found. However, the activity of ribulose-1,5-bisphosphate carboxylase (RuBPC) in M2014, and those of RuBPC and glyceraldehyde phosphate dehydrogenase in M2004 and hybrids were higher than in cv. Torsdag. The hybrids inherited the normal structure of photosynthetic apparatus of standard genotype in parallel with the compensatory gene complex of M2004, which was expressed at many levels of organization. This may be the basis of hybrid vigour in this case. and O. B. Vaishlya ... [et al.].