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Recently, the classical morphological criteria and host range data used in the identification of powdery mildew fungi were supplemented with scanning electron microscope (SEM) and molecular phylogenetic analyses. This paper discusses the joint use of these methods in the identification of powdery mildew anamorphs causing new or emerging plant diseases in different parts of the world.

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The microbiological spoilage of foods depends on the initial microbiological contamination and some factors which influence the growth of microorganisms. Therefore, reducing the initial cell count is necessary for both extending shelf-life and improving food safety. Physical, chemical and combined treatments serve this purpose. In these experiments, the effect of trisodium phosphate dipping (0-15% solutions) was studied. Chicken wings were used, which after dipping (1 min) in the solution were packed in PE-PA-PE pouches and stored at 4 °C. Aerobic mesophilic (Nutrient Agar, Merck), pseudomonad (Pseudomonas Selective Agar, Oxoid), and Enterobacteriaceae counts (VRBD Agar, Merck) were determined by Spiral Plate Technique at 30 °C incubation temperature. Effect of 3.8, 5.7, 7.6% trisodium phosphate dipping solutions was studied as a function of storage time. Immediately after treatment, total colony count was reduced by maximum 1.5 log cycles. Pseudomonads were the most sensitive. One day after treatment with these low concentration solutions, the colony count was reduced by 2 log cycles. Na3PO4concentration higherthan 7.6% practically did not result in higher effectivity. The growth rate and maximum cell count of surviving fraction were estimated as a function of trisodium phosphate concentration. It can be concluded from fitted survival curves that immediately after treatment the initial viable cell count was reduced and the critical spoilage level (107g-1) has been reached 2-3 days later than in case of the untreated samples, i.e. the shelf-life was extended.

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Both the activated and the non-activated alkaline polymerization ofε-caprolactam were studied by DSC. In the latter case, a curve-resolving method was applied to separate the superimposed polymerization and crystallization processes. The counter-ion effect was taken into account in the complexing of the initiator cations by crown compounds.

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Two wheat-infecting isolates of WDV-WDV-B and WDV-F- were collected in the field of Martonvásár and Nagykovácsi. The complete genomes were amplified by PCR, cloned into pBKS+ plasmid and sequenced. The nucleotide divergence in the total genome of the five isolates-WDV- Fra, WDV-Cz, WDV-Swe, WDV-B and WDV-F-originating from different part of Europe were found to be 0.44-1.69%. The four genes- MP, CP, RepA and Rep-and two non-coding region-LIR and SIR- were compared and a phylogenetic tree was constructed.

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Recently, comprehensive molecular phylogenetic analyses of ribosomal DNA sequences have led to important advances in understanding the evolution of powdery mildew fungi (Erysiphales). These results have triggered major changes in the identification, taxonomy, and, thus, nomenclature of this group of plant pathogens. This paper reviews the recent nomenclatural changes of the Erysiphales and provides an up-to-date list of all the powdery mildew fungi reported from Hungary using the new names of the fungal taxa.

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Abstract  

Investigations of the possible use of Mössbauer measurements for the analysis of the corrosion products of iron are reported. The Mössbauer spectrum was measured at room and liquid nitrogen temperatures on two samples produced by different corrosion procedures. The isomeric shift, quadrupole splitting and magnetic splitting observed in the spectra yield information on the chemical composition. In this way, the chemical forms of the compounds in the samples could be established. The magnetic properties, revealed by the spectra taken at different temperatures, permitted the identification of the polymorphous modifications. The rust produced in air saturated with water vapour was found to consist of 50% (w/w) Fe2O3,∼40% γ-FeOOH, and ∼10% β-FeOOH, while the rust produced by periodical immersion in saturated calcium chloride solution is composed of about equal amounts of β-FeOOH and γ-FeOOH. These findings have been confirmed by the thermoanalytical curves of the samples. The Mössbauer effect presents a convenient method for the investigation of the corrosion products of iron.

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The change of the number of turnip moth (Scotia segetum Schiff.) females was examined at 65 different light trap stations between 1957 and 1990. There are two generations of the examined species in Hungary, but the indi­vi­dual number of the first generation is low year by year, so we process­ed only the data of the second generation. Only those generations were examined that had more than 100 samples because of the statistical reliability. Thirty-three light trap stations were suitable for this examination. The joint number of yearly caught male and female individuals and also separately the samples of females were summarised for each observing station. The change of female individual number as a function of total individual number was determined from the coherent pairs of value. The connection can be described by linear function. The proportion of females is 38%. The relative frequency of females was also determined in the function of the individual number. The shown point-mass is similar to the damped vibration known at technical systems. It was established that the female proportion was higher than the average if the individual number is low, but it showed average value when the individual number was high. It can also be established that the female proportion is significantly high in some cases before gradation years.

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Journal of Radioanalytical and Nuclear Chemistry
Authors:
E. Kuzmann
,
M. Varsányi
,
L. Korecz
,
A. Vértes
,
T. Masumoto
,
F. Deák
,
Á. Kiss
, and
L. Kiss

Abstract  

Neutron, and Mössbauer spectroscopy were used to study the possibility of cold nuclear fusion in Fe90Zr10 amorphous ribbon having high hydrogen absorbing ability. No significant changes in the neutron and in the spectra were found at deuterization performed electrochemically at different cathodic potentials. The observed differences between the Mössbauer spectra of samples deuterized in air and in nitrogen atmosphere can be explained by decrease of deuterium uptake as well as by a small heat effect due to reaction of hydrogen with oxygen dissolved in water in the case of electrolysis carried out in air.

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Identification and classification of numerous Festucaspecies is still a difficult problem due to the close morphological resemblance. The most difficult fine fescues to identify belong to the Festucaovinaaggregate, which is the largest group in the genus Festuca. Many taxons are considered to be separate species based on quantitative taxonomic characters, differences in ploidy level or the structure of sclerenchyma cells. In order to evaluate the taxonomic value of DNA-based markers, sequence analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and the chloroplast trnL (UAA) intron was performed in the ten most problematic fine fescues belonging to the Festuca ovinaaggregate. Intraspecific ITS variants were found in a single case while in other cases only intragenomic ITS polymorphisms were detected with 1-2 ambiguous positions. Among the sequences of the trnL (UAA) intron even intragenomic polymorphisms were not detected in any of the Festucaspecies studied. Thus, the results do not support the species status of these ten taxa.

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