Search Results

You are looking at 1 - 10 of 17 items for

  • Author or Editor: Z. Á. Nagy x
Clear All Modify Search

Twenty-seven isolates of Phytophthora infestans collected in Hungary in 2001 were tested for mating type, response to metalaxyl, isozyme geno­type at glucose-6-phosphate isomerase (Gpi) and peptidase A (Pep) loci and nuclear DNA fingerprints with probe RG57. The ratios of the mating types A1 to A2 were 5:6 and 9:7 among isolates from potato and tomato, respectively. Seventeen isolates were sensitive to metalaxyl, 1 isolate responded intermediately and 9 isolates were resistant. No novel combi­nations of isozyme alleles were found; all isolates were Gpi 100/100, and genotypes at the Pep locus were 96/96 (63%), 83/96 (11%) and 100/100 (26%). In contrast, all of the 22 RG57 fingerprints exhibited patterns that have not been reported in Hungary before. On the basis of combined traits, 22 multilocus genotypes, unnoted elsewhere in Europe, were con­struct­ed among the 27 isolates analysed. These results indicate that varia­bi­lity in the Hungarian P. infestans populations is likely due to local events (asexual and sexual interactions) rather than migration from other countries.

Restricted access

The potentiometric electronic tongue is a new and rapidly developing technique. However, the description of the exact working mechanism is still absent. An important part of this description is the effect of the sample temperature on the measurement results. The paper reported here gives a description of the effect of temperature on results obtained with an α-Astree potentiometric electronic tongue. The yielded model was used to perform a temperature correction as if the samples were measured at room temperature (25 °c).

Restricted access
Authors: Sz. Fóti, Sz. Czóbel, J. Balogh, J. Nagy, A. Juhász, Z. Nagy, S. Bartha and Z. Tuba
Restricted access

A total of 123 isolates of Phytophthora infestans were recovered from 43 commercial fields and allotments of potato and tomato in Hungary. Isolates were characterised for mating type, response to metalaxyl, isozyme genotype at glucose-6-phosphate isomerase (Gpi) and peptidase A (Pep) loci, nuclear DNA fingerprint with probe RG57 and mitochondrial haplotype. Both mating types were detected in 8 potato and 3 tomato fields. The frequency of A1 and A2 were 47.5% and 52.5% on potato and 60.5% and 39.5% on tomato. More than sixty per cent of the whole population were resistant (31.1%) or responded intermediately (30.2%) to the fungicide metalaxyl in vitro. All isolates were monomorphic at the Gpi locus (100/100), but four allele combinations 100/100 (33%), 96/100 (28%), 96/96 (31%) and 83/96 (8%) were found at the Pep locus. Genotype Pep 83/96 is rare in Europe and all isolates with this allele combination were of A1 mating type and Ia mitochondrial haplotype. As in other European populations, only two of the four mitochondrial haplotypes (Ia, 32.5% and IIa, 67.5%) were detected. Diversity of RG57 fingerprints was high. Of the 79 different fingerprints found 67 were not detected previously.

Restricted access

Although much is known about the protective effect of acute estrogen therapy in cerebral ischemia, relatively little is known about the importance of apoptosis and cerebral plasticity in this mechanism. In this work 10 min global cerebral ischemia was produced by transient bilateral carotid occlusion in 4-month-old ovariectomized female gerbils. In every of our experimental group (sham for ischemia group, ischemia group and ischemia + a high, single dose 17β-estradiol pre-treatment group) apoptotic (bcl-Xl, bax) and cerebral plasticity (GAP-43, synapsin-I, nestin) hippocampal genes’ expression was measured four days after surgery. Expression of the anti-apoptotic bcl-Xl (p<0.01) and the cerebral plasticity marker synapsin-I and nestin (p<0.01) increased with acute estrogen pretreatment in ischemic animals. No change, however, in bax or GAP-43 expression was detected in estrogen treated animals compared to ischemic gerbils. These results suggest that acute estrogen therapy has anti-apoptotic effect and increases cerebral plasticity, which play an important role in cytoprotection or cerebroprotection.

Restricted access
Authors: Á. Nagy, J. Bogáncs, J. Gyulai, A. Csőke, V. Nazarov, Z. Seres, A. Szabo and Yu. Yazvitsky

Abstract  

A measuring technique based on the alpha particles being released from the10B(n, α) nuclear reaction and using the time-of-flight technique at a periodically pulsing reactor was developed. Non-destructive determination for the range distribution of boron impurities in ion-implanted silicon have been performed. Projected ranges obtained in the energy region 20–80 keV are compared to calculated results and to other experiments. Examples are shown for some typical boron distributions before and after annealing the sample.

Restricted access

The performance of a semisynthetic bisexual lure (SBL, containing isoamyl alcohol, acetic acid and red wine) previously found attractive for a number of noctuids was compared with that of the respective synthetic sex attractants of Orthosia cerasi (=stabilis), O. cruda, O. gothica, O. incerta, Anorthoa munda and Conistra vaccini. The respective sex attractants performed significantly better in the Orthosia spp. than the SBL lure, which, although regularly catching low numbers of both females and males, did not differ significantly from zero catch in unbaited control traps. On the other hand, the SBL lure performed as well as the sex attractant in C. vaccini. Sizeable catches of C. rubiginea, C. rubiginosa and C. erythrocephala were also recorded in traps with the SBL lure. The SBL lure can prove to be a useful tool in ecological and faunistical studies of Conistra and related hibernating Xylenini species.

Open access
Authors: A. Szabo, A. Fonseca, L. P. Biro, Z. Konya, I. Kiricsi, A. Volodin, C. Van Hasendonck and J. B.Nagy

Some recent results on the synthesis of coiled carbon nanotubes (CNTs) are summarized. Several supported catalysts can lead to the formation of coiled CNTs. Interestingly, certain domains of the coil pitch and coil diameter are favoured, and two “stability islands”are found in the 3D representation of the number of coiled CNTs as a function of both coil pitch and coil diameter. It is emphasized that these nanotubes are formed either by introducing pairs of five-membered ring - seven-membered ring or by forming haeckelite structures. The coiled CNTs could be used in nanocomposite reinforcement as well as special sensors based on their remarkable mechanical and electrical properties.

Restricted access
Authors: Sz. Nagy, A. Kovács, T. Zubor, Z. Zomborszky, J. Tóth and P. Horn

A simultaneous live/dead and acrosome staining, originally described for domestic mammals, was successfully applied on red deer (Cervus elaphus) and fallow deer (Dama dama) spermatozoa collected from the cauda epididymidis and vas deferens of shot stags. The staining is simple enough for routine application. Seven classes of spermatozoa were distinguished in the smears of frozen/thawed semen samples. Morphology, including cytoplasmic droplets, was evaluated as well. Percentage of live cells with intact acrosomes and with no other morphological aberrations might be a practical index of semen quality.

Restricted access