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261.
Plant uptake and solubility of lithogeneous, pedogeneous and anthropogeneous cadmium of an Ap-horizon from Orthic Luvisol In a pot trial we investigated the cadmium uptake by ryegrass (Lolium multiflorum) and spinach (Spinacea oleracea) in soil material of an Ap-horizon from Orthic Luvisol consisting of loess contaminated with Cd lithogeneously (stone powder), pedogeneously (soil from Ah- and Bv-horizon) and anthropogeneously (CdO) respectively. The concentration of Cd in the pots was adjusted to 1.5. 3 and 6 mg/kg soil. The total Cd-charge in the soil being at the same level, the tested plants (ryegrass and spinach) took up at least two times more of Cd of anthropogeneous origin (CdO) than of the Cd of geogeneous (pedogeneous and lithogeneous) origins. A remarkably higher solubility of the anthropogeneous cadmium was noticed compared with Cd of geogeneous origin. The DTPA-solution showed these differences most clearly. The relative soluble part of the anthropogeneous Cd was more than 60% of the total content, whereas it was lower by the factor of 2 to 3 in the geogeneously enriched cadmium. In the 0, 1 M CaCl2- and the acid (O.I M HCI + 0.125 M H2SO4)-extraction these differences were not as obvious. The DTPA soluble cadmium fraction and the Cd taken up by the plants tested showed the closest correlations. 相似文献
262.
Dombrink-Kurtzman MA Dvorak TJ Barron ME Rooney LW 《Journal of agricultural and food chemistry》2000,48(11):5781-5786
Studies were undertaken to determine the fate of the mycotoxins, fumonisins, during the process of alkaline cooking (nixtamalization), using normal-appearing corn that was naturally contaminated with fumonisin B(1) (FB(1)) at 8.79 ppm. Corn was processed into tortillas, starting with raw corn that was cooked with lime and allowed to steep overnight; the steeped corn (nixtamal) was washed and ground into masa, which was used to make tortillas. Calculations to determine how much of the original fumonisin remained in the finished products took into consideration that FB(1) will be converted to hydrolyzed fumonisin B(1) (HFB(1)) by the process of alkaline cooking. All fractions, including steeping and washing water, were weighed, and percent moisture and fumonisin content were determined. Tortillas contained approximately 0.50 ppm of FB(1), plus 0.36 ppm of HFB(1), which represented 18.5% of the initial FB(1) concentration. Three-fourths of the original amount of fumonisin was present in the liquid fractions, primarily as HFB(1). Nixtamalization significantly reduced the amount of fumonisin in maize. 相似文献
263.
We developed a basal area growth model for recovery of advance growth of Norway spruce trees after clear-cutting. Stem diameter growth at ground level and needle-mass characteristics were measured on permanent sample plots in Estonia. Both tree ring analysis (destructive sampling on one sample plot) and yearly repeated measurement data (two plots) were used to quantify advance growth. Basal area growth of small trees was estimated by multiple regression analysis. Previous-year basal area of the tree and basal area growth explained tree performance the next year. Tree needle-mass variables characterizing the acclimation status of the tree were included in the model as explanatory factors. Needle samples (one shoot from the upper third of each tree crown) were collected each year after the growth period from all sample trees. Needle masses of shoots from consecutive years were correlated and this variable was used as a predictor in the simulation model. Accelerating growth was observed in trees that exceeded the growth threshold in the year after release: the greater the needle mass per shoot, the greater the acceleration in growth. Competition among advance regeneration trees was included in the model: small trees under taller neighbors exhibited reduced growth. We found that trees released from a long period of heavy shade can survive, but the time needed for acclimation and resumption of competitive growth rates is considerably longer than for trees released from light shade. Such trees can be used for forest regeneration, but competition control (particularly reducing the proportion of fast-growing hardwoods) is required. 相似文献
264.
The reversal and splitting of traveling concentration waves was observed in a one-dimensional Belousov-Zhabotinski reaction medium under the influence of low-intensity electric field gradients ( approximately 10 V per centimeter). The wave reversal and splitting were strongly correlated with a characteristic transformation of the shape of both the wave front and the refractory tail of a wave in the local field gradient. The secondary role of generated hydrodynamic flow on wave transformation was also investigated. 相似文献
265.
Banks JA Nishiyama T Hasebe M Bowman JL Gribskov M dePamphilis C Albert VA Aono N Aoyama T Ambrose BA Ashton NW Axtell MJ Barker E Barker MS Bennetzen JL Bonawitz ND Chapple C Cheng C Correa LG Dacre M DeBarry J Dreyer I Elias M Engstrom EM Estelle M Feng L Finet C Floyd SK Frommer WB Fujita T Gramzow L Gutensohn M Harholt J Hattori M Heyl A Hirai T Hiwatashi Y Ishikawa M Iwata M Karol KG Koehler B Kolukisaoglu U Kubo M Kurata T Lalonde S Li K Li Y Litt A Lyons E Manning G Maruyama T Michael TP 《Science (New York, N.Y.)》2011,332(6032):960-963
266.
Marek Wełnicki Jacek L. Skrzeczkowski Włodzimierz Zagorski Stanisława Skrzeczkowska Anna Kowalska-Noordam Mirosława Was Waldemar Marczewski 《Potato Research》1990,33(4):497-503
Summary To assess the reliability of dot-spot hybridization assay for the Potato Spindle Tuber Viroid, more than 1000 potato samples
were cross-tested by biological and hybridization methods. Both methods gave similar results with a range of cultivars. The
dot-spot hybridization test was reproducible with formaldehyde-denaturated cell-sap samples stored at room temperature for
over 6 months. This finding means that samples can be transported from field stations to a diagnostic laboratory and allows
for cross-checking of results between laboratories. The data suggest that dot-spot hybridization is suitable for breeding
and quarantine purposes. 相似文献
267.
Nicolas Caille Marek Rodina Martin Kocour David Gela Martin Flajšhans Otomar Linhart 《Aquaculture International》2006,14(1-2):75-87
The spermiation of tench males was stimulated with Supergestran containing mammalian LHRHa lecireline at the following doses:
5, 10, 20 and 40 g kg−1 b.w.; then with carp pituitary suspension (CPS) at a dose of 2 mg kg−1 b.w. and with a control of saline physiological solution. The following days, meaning 24, 48 and 72 h after injection, sperm
was collected to evaluate volume and the number of sperm per male per kg body weight (B.W.) The percentage of motile sperm
and velocity of spermatozoa were measured 48 h after hormonal injection, and 72 h after hormonal injection the sperm was evaluated
for fertilization and hatching ability. All 42 males in experimental groups were diploid. Live weight did not differ significantly
among experimental groups. The strongest stimulation of spermiation was achieved with LHRHa in dosage of 20 and 40 g kg−1 b.w. and CPS compared to males of the control group and lower dosage of LHRHa. Analysis of variance showed no significant
influence of the treatment on the velocity and percentage of motile spermatozoa. The effect of different treatment on the
fertilization capacity (the number of spermatozoa per egg was equilibrated) was significant. Significantly the highest quality
of sperm collected 72 h after injection expressed by percentage of fertilization and hatching (62–65% fertilization and 61–64%
hatching rates, respectively) was found for LHRHa in dosage of 20 and 40 g kg−1 b.w. Significantly the lowest parameters of fertilization and hatching were found for the control group, on the 12% level. 相似文献
268.
Impact of fish size,water temperature,and MS‐222 concentration on inducing general anesthesia in pikeperch (Sander lucioperca)
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Maciej Rożyński Marek Hopko Konrad Stawecki Zdzisław Zakęś 《Aquaculture Research》2018,49(8):2774-2781
The aim of the study was to determine the optimum concentration of MS‐222 for given size groups of pikeperch and water temperatures. The study considered three size groups of pikeperch (body weight [BW] 8.56, 15.72, 52.91 g), an MS‐222 water solution (50, 100, and 150 mg/L), and two temperatures (20 or 23°C). It was revealed that the optimum MS‐222 concentration depended largely on the size of the pikeperch and on water temperature. For fish with a BW <10 g the recommended concentration is 100 mg/L but only at 23°C. For fish with a BW of 10–40 g at an immersion temperature of 20°C the safe MS‐222 concentration ranges from 100 to 150 mg/L. However, at a temperature of 23°C the recommended concentration of the anesthetic is 100 mg/L. Similarly for larger fish, that is, fish with a BW >40 g, the optimum MS‐222 concentration at a water temperature of 20°C is in the range of 100–150 mg/L, but at a temperature of 23°C is it approximately 100 mg/L. Additionally, when exposure to the anesthetic is shorter (several min), a concentration of 150 mg/L is also safe for juvenile pikeperch of this size. 相似文献
269.
Karol Ujházy Mariana Ujházyová Katarína Bučinová Marek Čiliak Stanislav Glejdura Ivan Mihál 《European Journal of Forest Research》2018,137(2):169-183
The effect of forest management on biodiversity is a crucial issue for sustainable forestry and nature conservation. However, the ways in which management affects macrofungal and plant communities and diversity of mountain temperate forests still remain poorly understood. We performed a random sampling stratified by stand age and stand type on the sites of temperate montane fir–beech forests. Diversity of macrofungi and the vascular plant understorey in beech- and spruce-dominated managed stands was investigated and compared to primeval forests located in the Po?ana Biosphere Reserve, Western Carpathians. Both the vascular plant and the macrofungal communities were altered by management, and the response of the macrofungal species (especially wood-inhabiting fungi) was more pronounced in terms of species composition change. Species turnover evaluation seems to be an important tool of forest natural status assessment, because alpha diversity did not change as much as species composition. Certain species of Carpathian primeval forests were confirmed as good indicators for natural forest change; others were proposed. Species pool and mean number of species per plot were the highest in unmanaged fir–beech forests, and species diversity significantly decreased in spruce plantations. The number of species decreased significantly due to the change of canopy tree species composition only in the macrofungal communities. As an outcome for forest management, we recommend keeping mixed forests involving all natural tree species and providing at least a minimal amount of dead wood necessary for wood-inhabiting organisms and leaving some area of unmanaged natural forests within complexes of managed stands. 相似文献
270.
Martin Urík Marek Bujdoš Katarína Gardošová Pavol Littera Peter Matúš 《Water, air, and soil pollution》2018,229(2):52
Selenite is an environmental toxicant whose mobility is affected in soil by various natural components, including humic acids, clay minerals, amorphous ferric oxyhydroxides [FeOx(OH)y], and microorganisms. However, interactions of selenite with these components are usually evaluated separately. Therefore, we addressed selenite behavior in multicomponent system in this study with emphasis on its immobilization and fungal accumulation. Our results highlighted significant acidification of culture medium by common soil fungus Aspergillus niger’s production of protons in selenite presence which affected selenium immobilization. While bentonite and humic acids did not enhanced immobilization efficiency significantly, composite of FeOx(OH)y/humic acids was extremely successful in selenium immobilization. This was most likely by enhanced redox transformation of selenite into elemental selenium as the contribution of each component was synergistic. Subsequently, selenium bioavailability in culture medium decreased and negatively affected bioaccumulation efficiency by fungus. Our results highlighted the significance of multicomponent systems in more realistic evaluation of selenium mobility and transfer to microorganisms. 相似文献