Microstructure of a rapidly quenched nanocrystalline Hf11Ni89 alloy from X-ray diffraction

A rapidly quenched nanocrystalline Hf(11)Ni(89) alloy was produced by melt-spinning. The X-ray phase analysis shows that the as-quenched ribbon consists of mainly nanocrystalline fcc HfNi(5) although a small amount of Ni is also detected. The crystallite size distribution and the dislocation structure of the dominant HfNi(5) phase were determined by a recently developed method of diffraction profile analysis. In this procedure, by assuming spherical shape and log-normal size distribution of crystallites, the measured physical intensity profiles are fitted by the well established ab initio functions of size and strain peak profiles. The anisotropic broadening of peak profiles is accounted for by the dislocation model of the mean square strain in terms of average dislocation contrast factors. It was found that the median and the variance of the crystallite size distribution are 3.3 nm and 0.70, respectively. The dislocation density is 5.7x10(16) m(-2) and the character of dislocations is nearly pure screw

The influence of different substrates on the reproduction traits of Folsomia candida (Collembola) in an insecticide test

The standard OECD tests for Folsomia candida should be performed on the standard OECD soil. However, if it is necessary to measure more parameters than the juvenile number and mortality, the use of different substrates is necessary. But these substrates can modify the results of the experiments comparing to the standard OECD soil, resulting in different toxicity values. In our research, we tested the toxicity of an insecticide, Trebon® 10F to F. candida (Collembola). We tested the dose-dependent effect of Trebon® 10F on the egg number and the egg size on the substrates of (i) plaster of Paris mixed with activated charcoal and (ii) in standard OECD soil on two generation of collembolas. Similarly to our previous study, the insecticide had a dose-dependent negative effect on the parent’s egg size in the OECD soil, but on plaster of Paris, no response was found. The egg number did not show any response to the treatments. On the contrary, in the offspring generation, the egg size increased both in OECD and plaster of Paris tests. In the soil test, parent collembolas laid significantly more eggs, while the offspring laid much fewer, compared to the plaster of Paris test. Similar results were found in the case of egg size. In the soil test parent collembolas laid larger, while the offspring laid smaller eggs, compared to the plaster of Paris test. In multigenerational tests (i) Trebon 10F could affect the different generations in the opposite way. The experiment performed on the plaster of Paris (ii) could underestimate toxicity compared to the OECD soil test. This should be taken into account when Ecotoxicologists interpret their data

A mézelő méh (Apis mellifera L.) vírusfertőzéseinek és a méhpatogén vírusok molekuláris szerkezetének tanulmányozása = Investigations on the viral infections of the honey bee (Apis mellifera L.) and on the molecular structure of bee pathogens

A mézelő méh vírusainak vizsgálatára irányuló kutatások keretében polimeráz láncreakcióra (PCR) alapozott felmérő vizsgálatokat végeztünk magyarországi és ausztriai méhészetekben a hat legfontosabb vírus előfordulási gyakoriságának megismerésére. Elsőként mutattuk ki a méhek szárnydeformitását okozó vírus, a fekete anyabölcső vírus, a lárvatömlősödés vírus és a krónikus méhbénulás vírus előfordulását hazai és ausztriai méhészetekben. Eltéréseket tapasztaltunk a vírusok hazai és külföldi előfordulási gyakorisága között. Filogenetikai vizsgálatokat végeztünk a fekete anyabölcső vírus közép-európai törzseinek bevonásával és feltártuk a vírus különböző genomterületeinek változékonyságát. A méhek szárnydeformitását okozó vírus világszerte gyűjtött törzseinek filogenetikai összehasonlítása során nagyon közeli rokonságot tapasztaltunk a vizsgált szekvenciák között, amely a vírus közelmúltbeli gyors terjedésére utal. Ez a terjedés valószínűleg összefüggésben áll a Varroa destructor atka elterjedésével, mivel ez a parazita hatékony vektora a vírusnak. Meghatároztuk a heveny méhbénulás vírus egy magyarországi és egy lengyelországi törzsének teljes genomszekvenciáját. A zab levéltetű (Rhopalosiphum padi) vírusát mutattuk ki méh eredetű mintákból. Folytattuk a hazai méhekből korábban kimutatott, a heveny méhbénuláshoz és a Kashmir méhvírushoz hasonló vírus genetikai jellemzését. Három méhvírus egyidejű kimutatására alkalmas multiplex RT-PCR alapú diagnosztikai módszert fejlesztettünk ki. | The project was focused on the investigations of honeybee viruses. Polymerase chain reaction (PCR)-based surveillance was performed on bee samples from Hungarian and Austrian apiaries to record the incidence of the six most important bee viruses. We have detected the deformed wing virus (DWV), the black queen cell virus (BQCV), the sacbrood virus, and the chronic bee paralysis virus for the first time in these countries. We found considerable differences in the prevalence of these viruses in different countries. Phylogenetic analyses were made on central European BQCV strains, and the variability of the different genome regions was recorded. By the genetic analysis of DWV strains collected worldwide, we detected close genetic relationship between the strains, which indicates a recent spread of the virus. This is probably in connection with the global spread of Varroa destructor, because this parasitic mite is an efficient vector of the virus. We have determined the complete genome sequence of a Hungarian and a Polish acute bee paralysis virus (ABPV) strain. We have detected the bird cherry aphid (Rhopalosiphum padi) virus in bee samples. We carried on the genetic characterization of a bee virus, which was detected in Hungary, and which is closely related to the ABPV and the Kashmir bee virus. We have developed a multiplex RT-PCR assay for the simultaneous detection of three viruses in honeybee samples

Response of winter wheat to arbuscular mycorrhizal fungal inoculation under farm conditions

The effect of arbuscular mycorrhizal (AM) fungi inoculation was investigated on two winter wheat cultivars (Triticum aestivum var. Mv Nádor and var. Genius) grown under farm conditions in the neighbourhood of Nagyhörcsök in 2016. The soil was a chernozem with lime deposits (WBR classification: Calcic chernozem) with a mean humus content of 2.73%, AL-soluble P2O5 and K2O concentrations of 181 mg kg-1 and 149 mg kg-1 and a pH(KCl) value of 7.27. The AM inoculum contained reproductive units of Rhizophagus irregularis (previously Glomus intraradices) and Glomus mosseae (syn. Funneliformis mosseae). In addition to soil inoculation, some of the treatments were also given mineral fertiliser treatment (130 kg N ha-1, 78 kg P2O5 ha-1, 60 kg K2O ha-1). Both AM inoculation and mineral fertiliser treatment were found to have a significant effect on the yield (at the p<0.05 level). The yield of plots with mycorrhizal inoculation averaged 8.17 t ha-1, which was higher than that of non-inoculated plots (7.52 t ha-1), while the yield of plots with fertiliser treatment averaged 8.31 t ha-1, as compared with 7.38 t ha-1 for non-fertilised plots. The yield-enhancing effect of AM inoculation was only manifested in plots given no mineral fertiliser. Plant protection measures were the same in all the treatments. The results and the conclusions drawn from them were based on the data of a single year (2016). Data from experiments performed in several years with more cultivars and soils with diverse properties will be required to obtain better grounded, more reliable recommendations for farmers