We established a multifactoral long-term field experiment at the Látókép experimental site of the University of Debrecen (Debrecen, Hungary), on mid-heavy calcareous chernozem soil in 1984, using experimental data from 17 years (1990-2008). We examined the extent to which soil fertility affects maize yield under natural conditions (without fertilisation). We analysed the effect of precipitation in the winter period (from the harvest of the previous crop (maize) until sowing (i.e. October-March)) and the growing season (i.e. April-September) on yield and we evaluated yield per FAO group. We examined the joint effect of crop year and hybrid maturity groups on maize yield; then we evaluated how hybrid maturity groups per crop year and wet and dry years per ripening group affected maize yield. It was shown that the pH value of soil significantly affected yield and also that there was a strong positive correlation between pH value and yield (r = 0.81) at a 1% significance level. The correlation between the two variables is described by a linear regression line. The slope shows that a 0.1 soil pH increase results in a 510 kg ha-1 maize yield increase on average. The correlation between the amount of precipitation during the growing season and maize yield is average, positive (r = 0.718) and linear. Based on the parameters of the estimated regression line - within non-fertilised conditions - 1 mm increase of precipitation resulted in a 9 kg ha-1 increase in yield. The analysis of the joint effect of hybrid maturity groups and crop year on yield showed that crop year determines standard deviation six times more than hybrid maturity groups, whereas the effect their interaction was not significant. and Práca bsahuje výsledky multifaktorového, dlhodobého pokusu na experimentálnej ploche Látókép, Univerzity v Debrecíne (Debrecen, Maďarsko). Experiment prebiehal od roku 1984, v tejto práci boli použité údaje z experimentu získané počas 17tich rokov (1990-2008). Pôda je stredne ťažká černozem. Bol skúmaný vplyv pôdnej úrodnosti na úrodu kukurice v prirodzených podmienkach, bez hnojenia. Študoval sa predovšetkým vplyv zrážok počas zimného obdobia (od zberu úrody kukurice až po nasledujúcu sejbu, t.j. od októbra do marca) a vplyv zrážok počas vegetačného obdobia (apríl -september) na úrodu kukurice. Okrem toho sa študoval vplyv ''sezóny'' a skupín skorosti hybridov na úrodu kukurice. Bolo vyhodnotený tiež vplyv skupiny skorosti hybridov počas suchých a mokrých rokov na úrodu kukurice. Bolo preukázané, že hodnota pH pôdy významne ovplyvňuje úrodu; súčiniteľ lineárnej korelácie medzi pH a úrodou na úrovni významnosti 1% bol r = 0,81. Z tejto korelácie vyplýva, že zvýšenie pH o 0,1 spôsobuje zvýšenie úrody kukurice priemerne o 510 kg ha-1. Korelácia medzi úrnom zrážok počas vegetačného obdobia kukurice a úrodou je pozitívna a lineárna (r = 0,718), z analýzy vyplýva, že zvýšenie úhrnu zrážok o 1 mm spôsobí priemerné zvýšenie úrody kukurice o 9 kg ha-1. Z výsledkov analýzy spoločného vplyvu skupín skorosti hybridov a sezóny vyplýva, že konkrétna sezóna ovplyvňuje tvorbu úrod 6-krát významnejšie, ako skupina skorosti hybridov; interakcia medzi skupinami skorosti hybridov a vlastnosťami sezóny nie je významná.
Soil water repellency causes at least temporal changes in the hydrological properties of a soil which result in, among other things, suboptimal growing conditions and increased irrigation requirements. Water repellency in soil is more widespread than previously thought and has been identified in many soil types under a wide array of climatic conditions worldwide. Consequences of soil water repellency include loss of wettability, increased runoff and preferential flow, reduced access to water for plants, reduced irrigation efficiency, increased requirement for water and other inputs, and increased potential for non-point source pollution. Research indicates that certain soil surfactants can be used to manage soil water repellency by modifying the flow dynamics of water and restoring soil wettability. This results in improved hydrological behavior of those soils. Consequently, the plant growth environment is also improved and significant water conservation is possible through more efficient functioning of the soil. and Vodoodpudivosť pôdy spôsobuje prinajmenšom dočasné zmeny v hydrologických vlastnostiach pôdy, ktoré okrem iného môžu viesť k suboptimálnym podmienkam rastu rastlín a k zvýšenej potrebe závlah. Vodoodpudivosť pôdy je rozšírenejší jav, ako sa pôvodne predpokladalo; bola identifikovaná v mnohých pôdnych typoch a klimatických podmienkach na celom svete. Dôsledkom vodoodpudivosti pôdy je strata zmáčavosti, zvýšený povrchový odtok a preferenčné prúdenie, znížená dostupnosť vody a iných vstupov pre rastliny, znížený účinok závlah, zvýšené požiadavky na vodu a iné vstupy, ako aj zvýšené riziko plošného znečistenia. Výskum naznačuje, že niektoré povrchovo aktívne látky (soil surfactants) môžu upraviť vodoodpudivosť pôdy obnovením omáčania a modifikáciou dynamiky vody. Výsledkom je zlepšenie hydrologických vlastností pôdy. Podobne, výsledkom je zlepšenie prostredia pre rast rastlín, zvýšenie retencie vody v pôde a teda aj efektívnejšia funkcia pôdy.
Different sustainable systems of husbandry on soil with various protective technologies are frequently studied. Direct sowing without ploughing is one of the alternatives. This article presents results of the effect of conventional tillage (CT) and no-tillage system (NT) on soil bulk density, soil porosity, maximum capillary capacity and available water capacity of Gleyic Fluvisol in conditions of the East-Slovakian Lowland. Observed years 1999 - 2005 from point of wiev of annual sum of precipitation are valued as dry till humid and of annual average air temperature as normal or warm. The effect of used agrotechnical arrangements was statistically highly significant (α = 0.01) for porosity changes and statistically significant for soil bulk density (α = 0.05). Non-significant effect was found for maximum capillary capacity and available water capacity. In the soil layer 0 - 0.3 m during years 1999 - 2005 soil bulk density increased about 22 kg m-3 (1.54 %) at no-tillage system in comparison to conventional tillage. At no-tillage system average values of porosity decreased about 1.32 %, maximum capillary capacity and available water capacity non-significantly decreased about 0.32 % in comparison to conventional tillage. and V trvalo udržateľných sústavách hospodárenia na pôde sa do popredia dostávajú rôzne ochranné technológie obrábania pôdy, medzi ktoré patrí aj priama sejba bez orby. Predkladaný príspevok sa zaoberá vplyvom konvenčnej agrotechniky (CT) a bezorbového systému (NT) na objemovú hmotnosť, pórovitosť, maximálnu kapilárnu kapacitu a využiteľnú vodnú kapacitu fluvizeme glejovej v podmienkach Východoslovenskej nížiny. Sledované roky 1999 - 2005 sú z hľadiska ročných zrážkových úhrnov hodnotené ako suché až vlhké a z hľadiska priemerných ročných teplôt vzduchu ako normálne, resp. teplé. Vplyv použitých systémov agrotechnických opatrení sa štatisticky významne (α = 0,01) prejavil pri pórovitosti, štatisticky na hranici významnosti (α = 0,05) pri objemovej hmotnosti a štatisticky nevýznamne pri maximálnej kapilárnej kapacite a využiteľnej vodnej kapacite. V porovnaní s konvenčnou agrotechnikou sa pri bezorbovom systéme zvýšili priemerné hodnoty objemovej hmotnosti vo vrstve pôdneho profilu do 0 - 0,3 m za roky 1999 - 2005 o 22 kg m-3 (1,54 %); priemerné hodnoty pórovitosti sa znížili o 1,32 %, hodnoty maximálnej kapilárnej kapacity a využiteľnej vodnej kapacity o 0,32 %.
Chronic kidney disease (CKD) is associated with increased concentration of intracellular calcium, which is pathological and may lead to irreversible damage of cell functions and structures. The aim of our study was to investigate the impact of 6 months vitamin D3 supplementation (14 000 IU/week) on free cytosolic calcium concentration ([Ca2+]i) and on the plasma membrane calcium ATPase (PMCA) activity of patients with CKD stage 2-3. PMCA activity of patients was also compared to that of healthy volunteers. Vitamin D3 supplementation of CKD patients resulted in the decrease of [Ca2+]i (119.79±5.87 nmol/l vs. 105.36± 3.59 nmol/l, n=14, P<0.001), whereas PMCA activity of CKD patients (38.75±22.89 nmol Pi/mg/h) remained unchanged after vitamin D3 supplementation (40.96±17.74 nmol Pi/mg/h, n=14). PMCA activity of early stage CKD patients before supplementation of vitamin D3, was reduced by 34 % (42.01±20.64 nmol Pi/mg/h) in comparison to healthy volunteers (63.68±20.32 nmol Pi/mg/h, n=28, P<0.001). These results indicate that vitamin D3 supplementation had a lowering effect on [Ca2+]i and negligible effect on PMCA activity in CKD patients., M. Morvová Jr., I. Lajdová, V. Spustová, M. Zvarík, L. Šikurová., and Obsahuje bibliografii
In cardiac surgical patients we investigated the effects of cardiopulmonary bypass (CPB) with a hollow fiber membrane oxygenator on blood clotting measured by thromboelastography (TEG). We found only a minimal change in the strength of blood clot described either by the TEG parameter MA (maximum amplitude) or by the shear modulus G calculated from MA. After CPB there was also a significant tendency towards hypercoagulation as defined by shortened parameters R, K and increased ?-angle. After comparison with published data obtained in cardiac surgical patients using a bubble oxygenator we conclude that currently used extracorporeal technology exerts a less negative influence on blood clotting than had been conceived previously., M. Horáček, K. Cvachovec., and Obsahuje bibliografii
The effects of condensed tannins (CTs) extracted from five species of plants on egg hatching and larval development of Teladorsagia circumcincta (Stadelmann, 1894) (syn. Ostertagia circumcincta) were evaluated using in vitro bioassays. The extracts of CTs were obtained from Lotus pedunculatus (LP), Lotus corniculatus (LC), Dorycnium pentaphyllum (DP), Dorycnium rectum (DR) and Rumex obtusifolius (RO). The results of egg hatching assay showed that about 53%, 68%, 51%, 60% and 46% of the eggs hatched when in vitro incubations contained 900 mg/ml of CTs from LP, LC, DP, DR and RO, respectively (P< 0.001 relative to control incubation), while in control incubations (no CT added) 87% of the eggs hatched. In the larval development assay, development was allowed to proceed for 7 days, by which time 89% of the hatched larvae in control wells (no CTs) had reached the infective third stage (L3). In incubations containing 200 mg CT from LP, LC, DP, DR and RO/ml, about 8%, 15%, 14%, 8% and 4% of the eggs attained full development to L3 larvae, respectively (P< 0.001 relative to control incubation). Only 1% of the eggs were able to develop to L3 larvae in incubations containing 400 mg CT extracted from LC/ml, whilst in the incubations containing the same concentration of other CTs the eggs were not able to develop to L3 larvae. It seems that CTs are not only slowing down the larval development but also kill the undeveloped larvae. At 400 mg/ml, for example, CT from LP, LC, DP, DR and RO killed 67%, 48%, 68%, 93% and 91% of first-stage (L1) and second-stage (L2) larvae, respectively. This study shows that CTs are able to disrupt the life cycle of nematodes.
Of the four tested sweet potato cultivars having different features in growth and yield, cv. Koganesengan (KOG) was sustainable in photosynthetic activity through young to aged leaves under drought. One of the causes for this phenomenon may be stomatal conductance (g s) of this cultivar that was relatively high in both aged and drought-imposed leaves. In these leaves the non-photochemical quenching (NPQ) was low and the quantum yield of photosystem 2 (Φe) was high, compared to those of the other cultivars. This helps to prevent excessive accumulation of chemical energy in leaves and a decrease in photoinhibition damage to the photosynthetic function, by which KOG sustains a relatively high photosynthetic activity under the drought and alleviates functional deterioration caused by leaf age. and Haimeirong, F. Kubota.
a1_We investigated the light reactions, CO2 assimilation, but also the chloroplast ultrastructure in the upper three functional leaves (flag, 2nd, and 3rd leaves) of the Chinese super-high-yield hybrid rice (Oryza sativa L.) Liangyoupeijiu (LYPJ) with ultraviolet-B (UV-B) treatment during reproductive development. Photosynthetic parameters showed that the upper 3 functional leaves of LYPJ entered into senescence approximately 15 days after flag leaf emergence (DAE). Leaves in UV-B treatment exhibited greater efficiency in absorbing and utilizing light energy of photosystem II (PSII), characterized by higher chlorophyll (Chl) content and the whole chain electron transport rate (ETR). However, UV-B radiation reduced activities of Ca2+-ATPase and photophosphorylation. The significantly decreased activity of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) was greatly associated with the decline in photosynthetic efficiency. The net photosynthetic rate (PN) and stomatal conductance (gs) suffered strong reductions before 25 DAE, and afterwards showed no significant difference between control and treatment. UV-B treatment delayed chloroplasts development of flag leaves. Chloroplast membranes later swelled and disintegrated, and more stromal thylakoids were parallel to each other and were arranged in neat rows, which might be responsible for better performance of the primary light reaction. It is likely that accumulation of starch and an increase in the number of lipid droplet and translucent plastoglobuli were results of an inhibition of carbohydrate transport. Our results suggest that long-term exposure to enhanced UV-B radiation was unlikely to have detrimental effects on the absorption flux of photons and the transport of electrons, but it resulted in the decrease of photophosphorylation and Rubisco activation of LYPJ., a2_The extent of the damage to the chloroplast ultrastructure was consistent with the degree of the inhibition of photosynthesis., G. H. Yu ... [et al.]., and Obsahuje bibliografii
The present study investigated the effects of head cooling during endurance cycling on performance and the serotonergic neuroendocrine response to exercise in the heat. Subjects exercised at 75 % VO2max to volitional fatigue on a cycle ergometer at an ambient temperature of 29±1.0 °C, with a relative humidity of approximately 50 %. Head cooling resulted in a 51 % (p<0.01) improvement in exercise time to fatigue and Borg Scale ratings of perceived exertion were significantly lower throughout the exercise period with cooling (p<0.01). There were no indications of peripheral mechanisms of fatigue either with, or without, head cooling, indicating the importance of central mechanisms. Exercise in the heat caused the release of prolactin in response to the rise in rectal temperature. Head cooling largely abolished the prolactin response while having no effect on rectal temperature. Tympanic temperature and sinus skin temperature were reduced by head cooling and remained low throughout the exercise. It is suggested that there is a co-ordinated response to exercise involving thermoregulation, neuroendocrine secretion and behavioural adaptations that may originate in the hypothalamus or associated areas of the brain. Our results are consistent with the effects of head cooling being mediated by both direct cooling of the brain and modified cerebral artery blood flow, but an action of peripheral thermoreceptors cannot be excluded., L. Ansley, G. Marvin, A. Sharma, M. J. Kendall, D. A. Jones, M. W. Bridge., and Obsahuje bibliografii a bibliografické odkazy