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121.
122.
D. A. Ivanov V. A. Tyulin O. V. Karaseva M. V. Rublyuk N. V. Grits 《Russian Agricultural Sciences》2013,39(3):264-267
Features of existential dynamics of a crop of spring wheat of grade Lada within the limits of agro-landscape moraine hills are investigated. Laws of influence of agroclimatic and landscape conditions on efficiency of culture are revealed. Recommendations on adaptation of manufacture of grain to landscape conditions are given. 相似文献
123.
A Schneider VA Absalon‐Medina G Esposito MN Corrêa WR Butler 《Reproduction in domestic animals》2013,48(6):989-994
Normal metabolic activity in ovarian follicles may result in oxidative stress and damage to oocytes. The aim of this study was to evaluate expression of the natural anti‐oxidants paraoxonase (PON) 1, 2 and 3 in granulosa cells and PON1 activity in follicular fluid (FF) and plasma of dairy cows. For the first experiment, ovaries were collected from cows at slaughter, after which follicles were dissected and classified as oestrogen active (EAF) or atretic (ATF). Expression of PON1, PON2 and PON3 mRNA was evaluated in granulosa cells, and activity of PON1 was measured in FF. PON1 mRNA was undetectable in granulosa cells, PON2 mRNA expression was not different between follicle types, and PON3 mRNA tended to be higher in EAF (p = 0.11). The activity of PON1 in FF was higher (p = 0.01) for EAF (82.6 ± 8.0 kU/L) than ATF (53.9 ± 6.8 kU/L), as were high‐density lipoproteins (HDL), low‐density lipoproteins (LDL) and total cholesterol concentrations. In the second experiment, we aimed to compare plasma and FF PON1 activity in early lactation Holstein cows (n = 15) with pre‐ovulatory EAF. Activity of PON1 was twofold higher (p < 0.0001) in plasma (122.5 ± 11.1 kU/L) than in FF (61.4 ± 5.2 kU/L). Plasma concentrations were also higher (p < 0.0001) for HDL, LDL and total cholesterol when compared to FF. In conclusion, FF concentrations of PON1, HDL, LDL and total cholesterol were higher in healthy oestrogen active bovine follicles than in atretic follicles. PON1 was not expressed by granulosa cells indicating that high PON1 activity in bovine FF is apparently derived by transfer from blood in association with HDL. 相似文献
124.
It is shown that it is possible to use soil microorganisms for utilizing organic poultry farming wastes with the production of ecologically clean fertilizer that increases the yield and quality of agricultural products. The results obtained are the basis for developing highly effective technologies for environmental rehabilitation. 相似文献
125.
A detailed characterization of the relief, parent materials, soils, woody vegetation, and the links between them is given
for a small part of the southern taiga zone in the center of the East European Plain. A methodology for determining the vegetation
succession patterns on different soils with the use of the selectivity coefficient K is suggested. This coefficient is defined as the ratio between the frequency of occurrence of the given tree species on a
given soil and its average frequency of occurrence within the entire analyzed area (in the area of the reserve). The values
of K change from 0.2 to 3.6 and indicate positive (K > 1) and negative (K < 1) feedback relationships between the soils and vegetation. Changes in the frequencies of occurrence of different tree
species on different soils that took place over 19 years have also been studied. It is shown that spruce has a tendency for
settling on podzols, mixed spruce-oak-lime forests tend to develop on podzolized podburs, and lime and oak trees tend to develop
on soddy podburs. Birch stands are most often replaced by spruce and pine stands; aspen stands and a part of the birch stands
are replaced by lime and oak stands. The ecological plasticity of pine trees and the long age of this tree species ensure
the existence of a long transitional succession stage with the predominance of pine. These regularities are important for
predicting the further development of forest vegetation. 相似文献
126.
Sveshnikov D Ensminger I Ivanov AG Campbell D Lloyd J Funk C Hüner NP Oquist G 《Tree physiology》2006,26(3):325-336
We studied the influence of two irradiances on cold acclimation and recovery of photosynthesis in Scots pine (Pinus sylvestris L.) seedlings to assess mechanisms for quenching the excess energy captured by the photosynthetic apparatus. A shift in temperature from 20 to 5 degrees C caused a greater decrease in photosynthetic activity, measured by chlorophyll fluorescence and oxygen evolution, in plants exposed to moderate light (350 micromol m(-2) s(-1)) than in shaded plants (50 micromol m(-2) s(-1)). In response to the temperature shift, maximal photochemical efficiency of photosystem II (PSII), measured as the ratio of variable to maximal chlorophyll fluorescence (Fv/Fm) of dark-adapted samples, decreased to 70% in exposed seedlings, whereas shaded seedlings maintained Fv/Fm close to initial values. After a further temperature decrease to -5 degrees C, only 8% of initial Fv/Fm remained in exposed plants, whereas shaded plants retained 40% of initial Fv/Fm. Seven days after transfer from -5 to 20 degrees C, recovery of photochemical efficiency was more complete in the shaded plants than in the exposed plants (87 and 65% of the initial Fv/Fm value, respectively). In response to cold stress, the estimated functional absorption cross section per remaining PSII reaction center increased at both irradiances, but the increase was more pronounced in exposed seedlings. Estimates of energy partitioning in the needles showed a much higher dissipative component in the exposed seedlings at low temperatures, pointing to stronger development of non-photochemical quenching at moderate irradiances. The de-epoxidation state of the xanthophyll cycle pigments increased in exposed seedlings at 5 degrees C, contributing to the quenching capacity, whereas significant de-epoxidation in the shaded plants was observed only when temperatures decreased to -5 degrees C. Thermoluminescence (TL) measurements of PSII revealed that charge recombinations between the second oxidation state of Mn-cluster S2 and the semireduced secondary electron acceptor quinone Q(B)- (S2Q(B)-) were shifted to lower temperatures in cold-acclimated seedlings compared with control seedlings and this effect depended on irradiance. Concomitant with this, cold-acclimated seedlings demonstrated a significant shift in the S2 recombination with primary acceptor Q(A)- (S2Q(A)-) characteristic TL emission peak to higher temperatures, thus narrowing the redox potential gap between S2Q(B)- and S2Q(A)-, which might result in increased probability for non-radiative radical pair recombination between the PSII reaction center chlorophyll a (P680+) and Q(A)- (P680+)Q(A)-) (reaction center quenching) in cold-acclimated seedlings. In Scots pine seedlings, mechanisms of quenching excess light energy in winter therefore involve light-dependent regulation of reaction center content and both reaction center-based and antenna-based quenching of excess light energy, enabling them to withstand high excitation pressure under northern winter conditions. 相似文献
127.
M. A. Efimova A. V. Ivanov Kh. Z. Gaffarov A. I. Yarullin 《Russian Agricultural Sciences》2012,38(2):149-152
An ELISA test system was developed on the basis of using bovine parvovirus type I intended for revealing antibodies in bovine blood serum in sick, convalescent, and vaccinated animals. 相似文献
128.
The spatial and vertical distribution patterns of ferromagnetic particles in soddy-podzolic and chernozemic soils subjected
to technogenic loads have been studied. A classification of soil magnetic particles according to their morphological features
is suggested. It takes into account the shape and the character of the particles’ surface, which are specified by the genesis
of the particles, and may be used for diagnostic purposes. 相似文献
129.
Ramon De S. Leite M. Moreira M. Ivanov Breno M. De Araújo D. Moura B. Maria Ramon C. Feitosa N. Matsho O. Do Vale 《Journal of Sustainable Forestry》2018,37(1):15-24
An understanding of forest carbon budgets, such as the factors that influence different levels of carbon accumulation, is one of the first steps in protecting and restoring areas of plant cover. Univariate and multivariate regression analysis was applied to evaluate the influence of climate variables (Rainfall, and mean maximum and minimum temperatures) on intra-annual above-ground carbon accumulated in tree species of the Caatinga. Above-ground carbon accumulated in the trees was 0.06 Mg ha?1 month?1. Carbon allocation in the aerial parts of the trees increased significantly with rainfall. Maximum and minimum temperature had little influence on carbon storage; however, variations in carbon accumulation are best explained when minimum and maximum temperatures are added to the regression model for rainfall, thereby demonstrating the simultaneous effect of these variables, and better explaining the carbon increase. 相似文献
130.
The presented study shows the results of measuring soil respiration in typical burozems (Dystric Cambisols) under mixed Korean pine–broadleaved forests in the southern part of the Primorskii (Far East) region of Russia growing under conditions of monsoon climate. The measurements were performed in 2014–2016 by the chamber method with the use of a portable infrared gas analyzer. Relative and total values of the CO2 efflux from the soil surface on four model plots were determined. The intensity of summer emission varied from 2.25 to 10.97 μmol/(m2 s), and the total CO2 efflux from the soils of four plots varied from 18.84 to 25.56 mol/m2. It is shown that a larger part of seasonal variability in the soil respiration is controlled by the soil temperature (R2 = 0.5–0.7); the soil water content also has a significant influence on the CO2 emission determining about 10% of its temporal variability. The daily dynamics of soil respiration under the old-age (200 yrs) forest have a significant relationship with the soil temperature (R2 = 0.51). The pyrogenic transformation of Pinus koraiensis forests into low-value oak forests is accompanied by an increase in the СО2 efflux from the soil. 相似文献