39 research outputs found
Some Considerations on the Structure Refinement in Al-Based Alloys
Grain size is one of the most important characteristics that affect the processing and in turn the properties of alloys. Grain refinement determines many advantages in light alloy casting: it can be achieved using different methods, based on the available technological possibilities and on the performances that one has to obtain. By using grain refinement, important benefits can be reached, for both cast and wrought aluminium alloys: among other, the most important enhancement regards the fine distribution of the second phases, improved castability, reduction of shrinkage porosity, higher mechanical properties, as well as superior fatigue life. The present chapter is not exhaustive on this argument; however, in the first part it reports some current literature data and some perspectives about the grain refinement, while in the second part which has been mostly carried out within a current PhD Thesis focalized on the improvement of the properties of Al-based alloys by physical grain refinement methods, some experimentally obtained results have been presented and discussed
Internal transcribed spacer (ITS) evolution in populations of the hyperparasitic European mistletoe pathogen fungus, Sphaeropsis visci (Botryosphaeriaceae) : The utility of ITS2 secondary structures
We investigated patterns of nucleotide polymorphism in the internal transcribed spacer (ITS) region for Sphaeropsis visci, a hyperparasitic fungus that causes the leaf spot disease of the hemiparasite European mistletoe (Viscum album). Samples of S. visci were obtained from Hungary covering all major infected forest areas. For obtaining PCR products we used a fast and efficient direct PCR approach based on a high fidelity DNA polymerase. A total of 140 ITS sequences were subjected to an array of complementary sequence analyses, which included analyses of secondary structure stability, nucleotide polymorphism patterns, GC content, and presence of conserved motifs. Analysed sequences exhibited features of functional rRNAs. Overall, polymorphism was observed within less conserved motifs, such as loops and bulges, or, alternatively, as non-canonical GâU pairs within conserved regions of double stranded helices. The secondary structure of ITS2 provides new opportunities for obtaining further valuable information, which could be used in phylogenetic analyses, or at population level as demonstrated in our study. This is due to additional information provided by secondary structures and their models. The combined score matrix was used with the methods implemented in the programme 4SALE. Besides the pseudoprotein coding method of 4SALE, the molecular morphometric character coding also has potential for gaining further information for phylogenetic analyses based on the geometric features of the sub-structural elements of the ITS2 RNA transcriptPeer reviewe
Adatok a fehér fagyöngy (Viscum album) hazai rovar faunåjåhoz
The European mistletoe (Viscum album) is an evergreen, perennial, epiphytic, hemiparasitic shrub, which is widely distributed in Europe. Its occurrence induces extremely sensitive health of host trees further contributing to the phenomenon of forest decline spiral. Besides mechanical pruning a hyperparasitic fungus (Phaeobotryosphaeria visci) could be a successful candidate to develop an effective biocontrol agent against V. album. We were extensively aware of the insect community of European mistletoe in light of finding another potential agent. We collected and identified 22 insect species (4 Sternorrhyncha, 5 Heteroptera, 5 Coleoptera, 5 Hymenoptera, 2 Lepidoptera, 1 Diptera) from which eight are specialists restricted only to European mistletoe (Cacopsylla visci, Carulaspis visci, Hypseloecus visci, Pinalitus viscicola, Ixapion variegatum, Liparthrum bartschti, Synanthedon loranthi, Celypha woodiana). Species associations with this plant are reported here for the first time for two Heteroptera (Campyloneura virgula, Pentatoma rufipes), one Coleoptera (Sericoderus lateralis), one ant species (Lasius brunnes) as well as for an aphid belonging to the Aphis fabae sensu stricto group, respectively. Species assotiation with this plant is reported for the first time in Hungary for the Leptophloeus hypobori species. Based on our observations and literature review only the mass occurrence of different pests would have the potential to effectively control this hemiparasite. From the pests of the green plant parts the mistletoe associated psyllid (Cacopsylla visi), mistletoe scale (Carulaspis visci) and the mistletoe bug, Hypseloecus visci, while from the pests of the woody parts a clearwing moth, Synanthedon loranthi and a bark beetle, Liparthrum bartschti look perspective in light if biological control.Peer reviewe
Optimizing conditions for sporulation of European mistletoe hyperparasitic fungus (Phaeobotryosphaeria visci): effect of light and different media
Volume: 50 Host publication title: 6th International Plant Protection Symposium at University of Debrecen Proceeding volume: 50European mistletoe (Viscum album), the hemiparasitic shrub, infects a wide range of woody species. It adversely affects the height and diameter growth and it is associated with increased mortality of its hosts. Currently there are no effective control methods against it. Therefor, we started to study a specific hyperparasitic fungus (Phaeobotryosphaeria visci), which can completely destroy European mistletoe by infecting its branches, leaves and berries. An important aspect of the initial phase of mycopesticide candidate is culturing of the organism on artificial or non-synthetic media, followed by the optimization of spore production. We focused to determinate the growth media and light conditions needed for sporulation of P. visci. We also tested the viability and pathogenecy of the spores, because these are important features for further processing and applications. The cultures were grown on seven different media (potato dextrose agar, sugar free potato dextrose agar, cellophane covered potato dextrose agar, oatmeal agar, V8 Juice agar, S medium and SNA medium) under constant dark, constant light (400-750 nm) and 12 h of alternating dark and light illumination. The best primary agar media were oatmeal and sugar free potato dextrose agar under permanent illumination, while constant dark inhibited the conidial production. The viability and virulence of harvested conidia were normal, and the symptoms of the disease appeared 7-14 days after the inoculation on mistletoe leaves. We will continue our experiments studying the effect of near UV (280â400 nm) light. Use of variable photoperiods supplemented with near UV and different media could help us to optimize the spore production and create a fast and cheap mass production technique.Peer reviewe
KĂŒlönbözĆ szisztĂ©mikus herbicidek fehĂ©r fagyöngy (Viscum album) elleni hatĂ©konysĂĄgĂĄnak, illetve a fagyöngy hiperparazita kĂłrokozĂłjĂĄra gyakorolt antifungisztatikus hatĂĄsĂĄnak vizsgĂĄlata
There are more than 3000 ha in Hungary infected by European mistletoe (Viscum album L.), which have currently raised. The only way to control this hemiparasite is to cut down the infected branches, while other effective control methods are unknown. Our research focused on the efficiency of herbicide control methods against V. album. We tested three herbicide agents and combinations in three concentrations during our study (glyphosate isopropylamine salt, 2,4-dichlorophenoxyacetic acid, methsulphuron-methil). After the pesticide treatments the phototoxic effects were studied on mistletoe shrubs and on the host trees (Acer campestre L.) too. The most efficient agent was 2,4-dichlorophenoxyacetic acid, which caused the whole necrosis of mistletoe shrubs even in the lowest concentration, but low chlorosis, rarification of foliage and drying of twigs were detected on the host trees. Phaeobotriosphaeria visci, which seems suitable for biological control, appeared 3â6 months after the application of 2,4-D on the necrotic mistletoe shrubs. Therefore the effect of 2,4-D and glyphosate on the mycelial growth were examined under in vitro laboratory conditions. Even the lowest herbicide concentration caused significantly lower mycelial growth; besides higher concentrations no mycelial growth was detected. An incidental combined herbicide and spore suspension treatment is not possible, due to the antifungal effects of these pesticides.Peer reviewe
Internal and external aspects of freedom of choice in mental health: cultural and linguistic adaptation of the Hungarian version of the Oxford CAPabilities questionnaireâMental Health (OxCAP-MH)
Background:Â A link between mental health and freedom of choice has long been established, in fact, the loss of freedom of choice is one of the possible defining features of mental disorders. Freedom of choice has internal and external aspects explicitly identified within the capability approach, but received little explicit attention in capability instruments. This study aimed to develop a feasible and linguistically and culturally appropriate Hungarian version of the Oxford CAPabilities questionnaireâMental Health (OxCAP-MH) for mental health outcome measurement.
Methods:Â Following forward and back translations, a reconciled Hungarian version of the OxCAP-MH was developed following professional consensus guidelines of the International Society for Pharmacoeconomics and Outcomes Research and the WHO. The wording of the questionnaire underwent cultural and linguistic validation through content analysis of cognitive debriefing interviews with 11 Hungarian speaking mental health patients in 2019. Results were compared with those from the development of the German version and the original English version with special focus on linguistic aspects.
Results:Â Twenty-nine phrases were translated. There were linguistic differences in each question and answer options due to the high number of inflected, affixed words and word fragments that characterize the Hungarian language in general. Major linguistic differences were also revealed between the internal and external aspects of capability freedom of choices which appear much more explicit in the Hungarian than in the English or German languages. A re-analysis of the capability freedom of choice concepts in the existing language versions exposed the need for minor amendments also in the English version in order to allow the development of future culturally, linguistically and conceptually valid translations.
Conclusion:Â The internal and external freedom of choice impacts of mental health conditions require different care/policy measures. Their explicit consideration is necessary for the conceptually harmonised operationalisation of the capability approach for (mental) health outcome measurement in diverse cultural and linguistic contexts
Application of direct PCR in rapid rDNA ITS haplotype determination of the hyperparasitic fungus Sphaeropsis visci (Botryosphaeriaceae)
Abstract Background The plant pathogenic fungus, Sphaeropsis visci a dark-spored species of Botryosphaeriaceae, which causes the leaf spot disease of the European mistletoe (Viscum album). This species seems to have potential as a tool for biological control of the hemiparasite. For the rapid detection of S. visci haplotypes we tested a direct PCR assay without prior DNA purification. This approach was based on a polymerase enzyme from the crenarchaeon Sulfolobus solfataricus engineered by fusion protein technology, which linked the polymerase domain to a sequence non-specific DNA binding protein (Sso7d). Findings Most isolates of Sphaeropsis visci grouped together in our phylogenetic analyses, indicating that isolates had a previously reported haplotype sequence, which is commonly found in the analyzed Hungarian population. This haplotype was also reported from diseased mistletoe bushes from other European countries. We further identified unique single nucleotide polymorphisms (SNPs) in the ITS region, which were specific to the only well resolved clade in the phylogenetic analysis. Conclusions The diPCR approach allowed amplification of ITS rRNA gene directly from small amounts of fungal samples without prior DNA extraction. This simple bioassay in plant disease management enables collection of genomic data from fungal plant pathogen populations.Peer reviewe
Changes in the Distribution of European Mistletoe (Viscum album) in Hungary During the Last Hundred Years
Peer reviewe
Aromatic stacking between nucleobase and enzyme promotes phosphate ester hydrolysis in dUTPase
Aromatic interactions are well-known players in molecular recognition but their catalytic role in biological systems is less documented. Here, we report that a conserved aromatic stacking interaction between dUTPase and its nucleotide substrate largely contributes to the stabilization of the associative type transition state of the nucleotide hydrolysis reaction. The effect of the aromatic stacking on catalysis is peculiar in that uracil, the aromatic moiety influenced by the aromatic interaction is relatively distant from the site of hydrolysis at the alpha-phosphate group. Using crystallographic, kinetics, optical spectroscopy and thermodynamics calculation approaches we delineate a possible mechanism by which rate acceleration is achieved through the remote ÏâÏ interaction. The abundance of similarly positioned aromatic interactions in various nucleotide hydrolyzing enzymes (e.g. most families of ATPases) raises the possibility of the reported phenomenon being a general component of the enzymatic catalysis of phosphate ester hydrolysis