Recent Atmospheric Deposition and its Effects on Sandstone Cliffs in Bohemian Switzerland National Park, Czech Republic

The protected area ??Bohemian Switzerland National Park?? with its characteristic sandstone landscape was influenced by the long-term air pollution and acidic deposition within the area known as Black Triangle (located where Germany, Poland, and the Czech Republic meet, is one of the Europe??s most polluted areas). The local Upper Cretaceous sandstone is subhorizontally stratified, fine- to coarse-grained, quartz dominated, with low content of clay minerals. One of the significant negative effects of the intensive acidic deposition on sandstone outcrops has been identified as chemical (salt) weathering, i.e., a process when the porous sandstone rock is except of chemical influence attacked also by force of crystallization of growing salts crystals. Anions NO ₃ ^? together with SO ₄ ^2? and cation NH ₄ ⁺ were the most abundant solutes in bulk precipitation samples. Current (2002 to 2009) bulk deposition fluxes of SO ₄ ^2? determined at three sites directly in the National Park indicate decline from 23 to 16 kg^?1 ha^?1 year^?1. Infiltration of bulk precipitation solutes into the sandstone mediates the weathering processes. Natural outflow of sandstone pore-water (sandstone percolates) can be sampled only during certain days of year when the sandstone becomes saturated with water and percolates drip out on small number of sites from roofs of overhangs. Under usual conditions percolation water evaporates at the sandstone surface producing salt efflorescences??the typical example is Prav?ická brána Arch locality. The average pH of the dripping sandstone percolates was 3.76. Concentration of SO ₄ ^2? and Al in sandstone percolates reached up to 46 and 10 mg L^?1. The concentration of Al in percolates has been 160-fold greater the one in the precipitation samples suggesting the sandstone as a source. The water O and H isotopic composition of percolates has been virtually identical to precipitation samples, indicating thus relatively short residence time of the solutions within the sandstone pore-spaces. Evaporation experiments with bulk precipitation and percolate samples proved possible origin of some Ca in bulk precipitation and the sandstone rock as the source of Al and possibly of K for the salt efflorescence identified on Rock Arch body.     

Characterization of in vivo-acquired resistance to macrolides of Mycoplasma gallisepticum strains isolated from poultry

ABSTRACT: The macrolide class of antibiotics, including tylosin and tilmicosin, is widely used in the veterinary field for prophylaxis and treatment of mycoplasmosis. In vitro susceptibility testing of 50 strains of M. gallisepticum isolated in Israel during the period 1997-2010 revealed that acquired resistance to tylosin as well as to tilmicosin was present in 50% of them. Moreover, 72% (13/18) of the strains isolated from clinical samples since 2006 showed acquired resistance to enrofloxacin, tylosin and tilmicosin. Molecular typing of the field isolates, performed by gene-target sequencing (GTS), detected 13 molecular types (I-XIII). Type II was the predominant type prior to 2006 whereas type X, first detected in 2008, is currently prevalent. All ten type X strains were resistant to both fluoroquinolones and macrolides, suggesting selective pressure leading to clonal dissemination of resistance. However, this was not a unique event since resistant strains with other GTS molecular types were also found. Concurrently, the molecular basis for macrolide resistance in M. gallisepticum was identified. Our results revealed a clear-cut correlation between single point mutations A2058G or A2059G in domain V of the gene encoding 23S rRNA (rrnA, MGA_01) and acquired macrolide resistance in M. gallisepticum. Indeed, all isolates with MIC ≥ 0.63 μg/mL to tylosin and with MIC ≥ 1.25 μg/mL to tilmicosin possess one of these mutations, suggesting an essential role in decreased susceptibility of M. gallisepticum to 16-membered macrolides.     

CO2 fluxes and drivers as affected by soil type,tillage and fertilization

Abstract

Importance of agricultural practices for greenhouse gases mitigation is examined worldwide. However, there is no consensus on CO₂ emissions as affected by soil management practices. Deeper understanding of soil CO₂ fluxes and drivers under different management practices are needed. The investigation of net CO₂ exchange rate as dependent variable and drivers (soil water and temperature, air temperature) as affected by soil type (loam and sandy loam), tillage (conservation and no-tillage) and fertilization are presented.

Soil management practices and weather conditions affected the CO₂ flux through effects on soil water and temperature regime. Mean net CO₂ exchange rate on sandy loam was 8% higher than on loam. No-tillage, as a moisture-conserving tool, could be an appropriate tool for CO₂ emissions mitigation in any weather conditions on sandy loam; however, the advantage of no-tillage on loam was negligible. Mineral NPK fertilizers promoted significantly higher net CO₂ exchange rate in both soils, but suppressed it by 15% on sandy loam during a normal year. Effect of soil water content on net CO₂ exchange rate was direct in all tillage and fertilization treatments in both loam and sandy loam, whereas this effect was positive only in dry and normal weather conditions. In wet weather conditions, the direct effect of soil water content on net CO₂ exchange rate was negative. Soil and air temperature acted indirectly on net CO₂ exchange rate. The increase in temperature markedly suppressed the positive direct impact of soil water content on net CO₂ exchange rate in dry weather conditions, but did not reduce the direct effect of soil water content in normal weather conditions. In a wet year the negative indirect effect of increased temperature enhanced the negative direct impact of soil water surplus on net CO₂ exchange rate.     

Incidence of eyespot on winter triticale and quantification of Oculimacula spp. population using real-time PCR in Lithuania

The aim of this study was to estimate the incidence of eyespot in winter triticale crops in different agro-ecological zones of Lithuania and to use real-time polymerase chain reaction (Real-time PCR) to determine the dominant Oculimacula fungi populations in winter triticale crops grown in Lithuania, which has not been previously established. Differences in common fungicide usage practices in triticale crops between Lithuanian agro-ecological zones suggest that the composition of Oculimacula fungi differs across the country. From 2008 to 2012, a total of 70 winter triticale fields were reviewed for eyespot incidence, and the presence of eyespot was identified in 93.5% of the fields tested. Over this five-year period, the disease incidence averaged 32%. The highest incidence (34.8%) of eyespot was found in the Middle Lowland zone of Lithuania, the lowest (25.8%) was in the Eastern zone and an intermediate incidence (30.2%) was observed in the Western zone. During the 2010–2012 period, Oculimacula acuformis was the most prevalent Oculimacula spp. in the majority of triticale crops inspected. Only in 3 cases out of 27 was the amount of Oculimacula yallundae DNA higher than that of O. acuformis. According to our results, the incidence of eyespot in triticale varied greatly and could be of economic importance in some fields. The predominance of O. acuformis over O. yallundae is an important consideration in the choice of fungicides for eyespot control.     

Buffer Capacity of Open Atmospheric Gas–Liquid Systems

Buffer capacity analysis of open atmospheric gas–liquid systems containing main acidic and basic atmospheric pollutants was carried out. Usually the buffer capacity is considered as a function of pH as an independent variable. In this work the buffer capacity is analysed including the dependence of pH on the composition of a system. Such an approach allows finding an important, from the viewpoint of atmospheric water acidification, relationship between the gas phase composition and the buffer capacity. It was found that buffer capacity of the open gas–liquid systems may be very high and it may cause the liquid phase pH to remain at low levels. The buffer capacity of the analysed systems is most strongly affected by the simultaneous presence of ammonia and strong acids in the gas phase. The higher concentrations of strong acid gases the lower NH₃ concentration is sufficient to achieve high buffer capacity. In the presence of strong acid gases, calcium ions affect both the buffer capacity and the liquid phase pH only at low NH₃ concentrations. High buffer capacity of open gas–liquid systems may be one of the reasons why the reduction in emissions of acidic gas pollutants has little effect on decrease in atmospheric water acidity.     

Influence of the length of time after hormonal stimulation on selected parameters of milt of ide Leuciscus idus L.

Milt of the Leuciscus idus L. was collected from five experimental groups, and selected parameters of its quality were analysed for 36 h (group II), 60 h (group III), 84 h (group IV) and 108 h (group V), respectively, after hormonal stimulation with Ovopel (1 granule kg^?1 of body weight). The control (group I) fish were not subjected to hormonal stimulation. The highest milt volume was obtained from the fish in group IV (0.70 ± 0.55 mL), where the largest volume of milt expressed per kilogram was also obtained (3.03 ± 1.94 mL kg^?1). Significant differences were also found in milt volumes obtained between group I and groups III (P<0.01) and IV (P<0.05). The highest percentage of motile spermatozoa was found in the milt of group IV (59%); significant differences were found between group I and groups II (P<0.01) and III (P<0.001). The value of osmotic pressure of seminal plasma was the highest in group IV (203.19 ± 37.63 mOsm kg^?1), and the lowest in group I (118.31 ± 41.13 mOsm kg^?1). Parameters determining milt quality and quantity indicate that the period of 60–84 h after hormonal stimulation with Ovopel is optimal for obtaining milt from ide.     

Source : sink ratio and leaf senescence in maize:: I. Dry matter accumulation and partitioning during grain filling

Whether the stay-green characteristic of recent maize hybrids is related to a larger source : sink ratio and/or a more efficient use of N during reproductive development was studied in a 3-year field experiment. The experiment was conducted with two short-season maize hybrids, Pride 5 (old) and Pioneer 3902 (recent), grown at two soil-N levels and with source : sink treatments during grain filling ranging from partial defoliation to no grain. Results confirmed that greater dry matter accumulation of Pioneer 3902, relative to Pride 5, was associated with greater leaf longevity. Change in stover weight from silking to maturity an indicator of the difference in supply and demand of assimilates during grain filling, varied from −30% with defoliation to +25% for the no sink treatment. The change was always greater in the new hybrid, indicating that the old hybrid was more source limited. Number of green leaves, an indicator of leaf longevity, was greatest when supply and demand of assimilates during grain filling were approximately equal. Leaf longevity was enhanced by an increase in soil N and the effect was larger in the high source : sink treatments, but differences in leaf longevity between the two hybrids were not influenced by soil-N level. In conclusion, increased leaf longevity of a new relative to an old hybrid was associated with a larger source : sink ratio during grain filling.     

Changes in Mass Element Fluxes and their Importance for Critical Loads: Geomon Network,Czech Republic

Three years (1994-1996) of runoff, bulk deposition, and throughfall S and N data obtained from GEOMON, a network of 14 small forest catchments in the Czech Republic, are presented. In this paper, we assess regional differences and temporal trends in S and N fluxes under changing regional burdens. Decreases in S deposition have occurred in the emission-burdened northern and western parts of the Czech Republic, where remedial measures have been applied. For example, at the Uhlí?ská catchment (Jizerské hory Mtns., northern Czech Republic), throughfall S fluxes decreased from 72.7 to 48.5 kg ha-1 yr-1. In contrast, the relatively clean central and southern parts of the Czech Republic showed an increase in S deposition; for example at the Na lizu catchment (?umava Mtns., southern Czech Republic) throughfall S fluxes increased from 9.0 to 18.8 kg ha-1 yr-1. In burdened catchments with damaged forests, high runoff of N was observed. Using fluxes of S and N measured at the GEOMON sites, we calculated critical loads and exceedances for both S and N in the catchments. The critical loads of S ranged from 505 to 3,631 mol L-1 yr-1 during 1994-1996; in about 80% of the catchments the critical loads were exceeded by atmospheric deposition; half of the catchments showed an exceedance for N.

     

Apical shoot tip culture of tomato

We studied the effect of phytohormones on growth and development of apical shoot tip of tomato (Lycopersicon esculentum Mill.). Whole plants rarely developed on basal medium containing NAA (-naphthylacetic acid). K (kinetin) and BAP (6-benzylamino purine) stimulated shoot development within the range of 0.1–10 μM. BAP at 5 and 10 μM induced shoot multiplication. The clonal progenies were phenotypically uniform and without chromosomal changes or meiotic irregularities. The potential uses for propagating genetically valuable tomato lines under in vitro conditions are discussed.     

Effect of albumin and casein supplementation on the common carp Cyprinus carpio L. sperm motility parameters measured by CASA

Adhesion of sperm to a glass surface can be manifested by the low percentage of motile spermatozoa and lower speed. This crucial factor could disprove the sperm quality prediction from computer-assisted sperm analysis (CASA) results. In our study, this was particularly observed when solution L was used. However, protein supplementation was effective in the reduction in sperm adhesion. We found that albumin increased the sperm motility at concentrations of 0.25 % in solution L and 0.5 % in solution P. Casein was effective in both solutions at 0.25 % concentration. However, in solution L, the motility was lower than that measured in solutions P and L with the supplementation of BSA at 0.25 and 0.5 %. BSA supplementation was especially beneficial in terms of higher speed values regardless of an activation solution. Casein used with solution P allows us to obtain similar results as in the samples activated with BSA supplementation. Casein supplementation to solution L did not increase CASA results to the level observed in the samples activated with BSA added to the solution L. Our data suggest that the selection of an activation solution is one of the most crucial steps in the experiments requiring CASA data. Depending on the composition, different protein supplements should be used to reduce adhesion of sperm to a glass surface. We recommend the use of BSA at the 0.5–1 % concentration because at this level we obtained the highest CASA parameters in both activation media.