The precipitation distribution of the Hungarian part of the Danube-Tisz Mid-Region (the centre of the Great Hungarian Plain) is discussed based on 70 years of mounthly data from eleven meteorlogical stations. The vegetation of the region belongs to the southeast Central-European forest-steppe zone. Besides the edaphic conditions, the vegetation is primarily constrained by the amount and seasonal distribution of pericipitation. Pericipitation years-types defined by the annual sums and the seasonal distribution of pericipitation including the time of maximum and minimum and minimum amounts within year were usedto compare the climate of the stations. Great differences were found between the northern and southern part of the region in the frequencydistributions of precipitation year types. Years with high amount of precipitation were more frequent at the northern park of the region, whileyears with low amount with low summer precipitation is also increased from north to south. Within this overall north to south gradient, two parallel gradients were distinguished in the western and the eastern part of the region. Along the western gradient, years with higher annual and summer precipitation had a higher frequency compared to the eastern gradient. Along both gradients, however, both annual and summer precipitation decreased towards the central part of the region. The two gradients revealed by the precipitation years correspond with chorological-floristical and coenological gradients detected by other studies in the region. Thus, our results may provide an explanation for these changes in the flora and the vegetation of the Danube-Tisza Mid-Region.
Clonal populations are hierarchically organized: genetic individuals (genets) can consist of many physiological individuals (ramets). Each ramet takes up resources from its local environment, but the resource pattern can be reorganized within the clone by transport between ramets. Thus, an integrated clone is not directly subject to the pattern of resource availability in its habitat. Local shortages can be compensated, hence, the clone can buffer itself against spatio-temporal heterogeneity in the habitat. We modelled a series of habitat types, assuming that one limiting resource was patchily distributed in space, and could fluctuate over time. Habitat types differed in the density, size and persistence of resource patches, and in the contrast between resource-rich patches and the resource-poor background. We applied an individual-based, spatially explicit population dynamic model to compare the performance of two plant strategies in these habitat types. In the Integrator, ramets that were interconnected distributed the resource evenly. In the Splitter, no resource translocation occurred. First we observed population growth of the two strategies separately, then in competition. We found a range of habitat types, where none of the strategies was viable, because of the scarcity of resource patches. As the density of resource patches was increased, first only the Integrator could persist. Then, at intermediate densities of resource patches, the Splitter became viable, and, being a stronger competitor, excluded the Integrator. Finally, at high resource-patch densities, the Integrator occupied the area again. Since the Splitter was viable at high density of resource patches when growing alone, its disappearance is more due to spontaneous extinction, due to competitive exclusion by the Integrator. We predict, therefore, the dominance of integrated clones both in extremely unproductive and productive environments, but for different reasons. It is important to note that this trend was observable only at high spatial and temporal variation in resource availability. Less contrast between patches of different quality, smaller patch sizes, or longer persistence of patches facilitated the dominance of the Splitter. Thus, buffering is advantageous in many but not all habitat types.
Eight Lactobacillus, five Saccharomyces and one Streptococcus strains were chosen to perform mono and mixed culture fermentations, focusing on interaction investigation via agar diffusion and analysis of cell growth kinetics, both serving as selection criteria. Mixed culture fermentations with four lactic acid bacteria (Lb. bulgaricus, Lb. paracasei SF1, Lb. plantarum 2142, and Lb. casei Shirota) and four yeast strains (S. cerevisiae W66, S. cerevisiae WS34/70, S. cerevisiae W120, and S. carlsbergensis 843) were performed in wort with initial cell ratio of 1:1. It was determined that during fermentations, cell concentration of lactic acid bacteria exceeded that of yeasts by one order of magnitude. Three strain combinations (S. carlsbergensis with Lb. bulgaricus, Lb. 2142, and Lb. Shirota) were chosen for further fermentations. Basic behaviour of them in wort was studied in mono culture, which helped to determine interaction type between bacteria and yeast in mixed culture. It resulted in higher Lactobacillus cell concentration in mono cultural than in mixed culture fermentation, which refers to competition. Cell ratio was changed to 1:10 (lactobacilli:yeasts), to favour growth of yeast and avoid lower pH. Despite the higher initial concentration of yeast, results turned in favour of lactobacillus already at the 24th hour.
Authors:P. Ittzés, É. Jákó, Á. Kun, A. Kun and J. Podani
A discrete mathematical method, based on the Jakó Iterative Canonical Forms (ICF) of Boolean functions is proposed for the analysis of species combinations and the detection of characteristic areas in plant communities. Information on species combinations (or florulas) appearing in a sample is expressed in compact form to reveal fundamental properties of community pattern. The new method provides a complementary tool for the florula diversity approach: whereas florula diversity is indicative of the frequency distribution of species combinations regardless their interrelationships, the new procedure detects complexity in the abstract structure of species combinations. Graph-theoretical representations of the ICF promote understanding the new method and visualizing its results. A cellular automata model and field data provide illustrative examples.
Gábor Fekete academician respectfully but affectionately called ‘Master’ (“Tanár Úr” in Hungarian, a version of ‘Professor’ that we used with a specific meaning of being not only a Tutor but Father and Master as well) by generations of vegetation scientists passed away on the 29th November 2016. His death deprived us of an experienced and didactic teacher who was loved by all. This warm regard was expressed in many commemorating writings published since his death. The present paper mainly concentrates on his scholarly work and the importance of his scientific findings also showing how particular publications signify stages in his scientific career.
Authors:ZS. Kiss, B. Vecseri-Hegyes, G. Kun-Farkas and Á. Hoschke
In the course of our work we aimed to develop a product from gluten-free raw materials (millet, sorghum and buckwheat) that is similar to beer made of barley malt but is consumable by coeliacs. Our measurements were started by qualification of cereal/pseudo-cereal grains. Next malts were made of them with different steeping, germination and kilning parameters, and their most important quality characteristics were determined. Qualification of grains were done by grading, determination of thousand-kernel and hectolitre weight, and protein content, while malts were examined with congress mashing, Hartong mashing and lauter test, as well. Gelatinization point of the starch found in grains and malts were determined by Brabender amyloviscograph which helped to set the temperature of β-amylase rest in future mashings. The gelatinization points were higher in our samples, than in the barley’s starch.Optimization of mashing was continued with malts that fulfilled requirements needed for brewing. Mashing programs were written for each raw material with the help of our laboratory mashing equipment, and resulting worts were analysed (for extract content), then carbohydrate content was measured by HPLC, α-amylase activity by Phadebas test, and free α-amino nitrogen (FAN) content by the ninhydrin method. Those worts were selected for further fermentation tests that had the highest extract and FAN content, best filtration time and appropriate sensory characteristics. Optimal malting temperatures and time periods, aeration and water uptake were determined, and then the duration and temperature of protein and enzyme rests of mashing were set.The malting process that proved to be the most suitable for brewing requirements (high extract content, good lautering characteristics, high FAN content) has the following parameters: steeping with 25 °C water for 18 h with aeration in every 5 h; germination at 15 °C for 84 h; kilning at 50 °C for 48 h.
Authors:A. Sebestyén, Zs. Kiss, B. Vecseri-Hegyes, G. Kun-Farkas and Á. Hoschke
Currently gluten-free beer is not produced in Hungary for coeliacs. The goal of our research was to develop brewery products made of domestically grown millet (Alföldi 1) and buckwheat (Oberon) that are similar to traditional beer of barley malt regarding taste, aroma, consistency, colour, foam stability and alcohol content.On a micromalting equipment malts were made of buckwheat and millet. Beer was produced on pilot plant scale (50 l) with decoction process (mashing program with rests at 50 °C, 65 °C and 72 °C) and was supplemented with a highly heat-stable bacterial α-amylase, a fungal α-amylase and β-glucanase. Malts were evaluated by congress mashing (extract content, extract difference, pH, and colour); wort and final beer analyses were performed as well (pH, extract, iodine test, FAN, colour, bitterness, alcohol and extract content). Finally, sensory characterization was carried out. Difficulties with lautering were encountered during the brewing process with buckwheat. The analytical results indicated that the buckwheat and millet beer had different values compared with a typical barley beer with regard to pH, FAN, fermentability, and total alcohol. The extracts of the buckwheat and millet wort were lower, resulting in a final attenuation of 61.5% and 73.2%.In laboratory experiments optimal temperature of β-amylase found in domestically grown buckwheat (64 °C) and millet (62 °C) was determined by detecting maltose production with HPLC. Data was used to set the rest temperature of the enzyme during mashing. Inhibiting effect of certain substances on proteolytic enzymes was investigated by measuring the extract, FAN, and soluble nitrogen contents. Inhibition was detected in case of both raw materials, although to a different extent. Inhibition is influenced by tannins and polyphenols found in the grain (Chethan et al., 2008).
Authors:András Pataricza, Z Márton, Z Hegedűs, Irén Krassói, A Kun, A Varró and J Gy Papp
Functional role of calcium-activated potassium (KCA) channels on the basal and agonist-elevated arterial tones was investigated in isolated rabbit aorta, porcine and canine coronary arteries as well as in human internal mammary artery. The vascular tones enhanced by contractile agents were increased further by preincubation of these conduit blood vessels with selective (charybdotoxin or iberiotoxin) or non-selective (tetraethylammonium) inhibitors of KCA channels. The basal tone (without an agonist) was increased only in the canine coronary artery. The results indicate a feed-back regulatory role of KCA channels counteracting the vasospasm of conduit arteries.
Authors:S. Bartha, G. Campetella, E. Ruprecht, A. Kun, J. Házi, A. Horváth, K. Virágh and Zs. Molnár
Decreasing diversity and plant cover, as well as increasing variability of these characteristics with increasing aridity are expected in grasslands due to climate change. These predictions were tested in perennial sand grasslands in Hungary. Two sites were chosen in different positions on an aridity gradient and two stands in each site were monitored for 9 years. Presence of plant species were recorded along 52 m long circular belt transects of 1040 units of 5 cm × 5 cm contiguous microquadrats. This sampling procedure — a version of line-intercept methods — enabled us to monitor diversity and total abundance in a sensitive, precise and non-destructive way. We found no trend but fluctuation in most community level attributes and in species composition. Contrary to fluctuations, between-site differences in diversity did not change and diversity remained lower in the more arid site during our 9-year-study. Compositional diversity performed better than species diversity because allowed us to detect vegetation changes that would have remained hidden if monitoring would be based only on the species richness. Comparing the magnitudes of fluctuations, five times higher relative interannual variability (CV%) was found for compositional diversity at the more arid site, while the relative temporal variability of total abundance and species richness did not show consistent patterns. We conclude that a 9 year-long study was too short to identify trends caused by the changing climate. However, the larger temporal variability of species combinations found in the more arid site suggests larger vulnerability and highlights the importance of non-linear dynamics during climate changes.