This paper demonstrates a possible application of large historical vegetation data sets as reference to reveal natural trends. Phytosociological releves re-sampled after 3–6 decades were used to detect and interpret long-term plant compositional changes of seven rock grassland communities in Hungary. Altogether 151 re-established plots were subject of the study. Data analyses were designed to minimize the negative effects arising from the application of historical information. Principal coordinates analysis was used to discover general compositional changes. With the help of ecological indicator values and species attributes, vegetation state trends were evaluated. Principal coordinates analysis reveals a uniform displacement of plot averages in the ordination space. Ecological indicator values for nitrogen requirement of vascular plants show a significant increase in mesotrophic categories. Occurrences of species typical of rock grasslands decreased significantly. Natural pioneers, disturbance-tolerant and weed species increased in number. Nevertheless, their amount is relatively low and the natural constituents of the communities still dominate, which is a sign of only a minor disturbance. Considering the wide geographical distribution of the sample plots, general changes seem to indicate pressures operating at large scales. These include elevated nitrogen deposition, increased rates of erosion and trampling caused by overpopulated ungulates and more frequent summer drought events. Acidification only occurs in silicate grasslands as calcareous soil types have higher buffering capacities. The global tendency of biotic homogenisation with the increase of common species was also detected over time. The study showed that the use of historical vegetation data enables us to estimate long-term trends in vegetation state.
Authors:K. Szabó, L. Nagy, G. Török, D. Hegedüs, and G. Fóti
A control system for monitoring the radioactive concentration in aqueous wastes of nuclear installations was elaborated. The
mobile station developed for in situ control enables simultaneous measurement of gamma radiation in the energy range of 0.15–2.0
MeV and that of beta radiation in the energy range of 0.3–2.0 MeV by means of a combined scintillation detector. Disturbing
effects of accompanying and secundary radiations on the determination of the counting efficiency vs. radiation energy functions
used in calculation of the radioactive concentration limits as well as some experiences during a long time of operation of
the system have been discussed.
Authors:K. Török, L. Hajas, Zs. Bugyi, G. Balázs, and S. Tömösközi
Disorders induced by cereal proteins (e.g. wheat allergy, celiac disease) are widespread in human population. Since their only effective treatment is the avoidance of the problematic proteins, patients have to be familiar with the composition of food products. For checking special foods produced for them, proper analytical methods are necessary. At the moment, in gluten analysis there are no reference methods and reference materials which model real food matrices. During the production and experimental utilisation of our previously developed reference material candidate, numerous questions emerged. As our model product is a real food matrix, interactions can be present between gluten proteins and other macro and micro components. Fat content of the baked cookies is almost 20%, which might affect the results of ELISA measurements. The detectable gluten content is significantly increasing after the defatting procedure, as a pre-treatment of samples. Moreover, baking is a common food processing step that might modify the structure of gluten proteins leading to denaturation and aggregation. In the soluble protein fraction the amount of low molecular weight proteins increases, while that of high molecular weight proteins decreases during the baking procedure.
Authors:E. Schall, Zs. Bugyi, L. Hajas, K. Török, and S. Tömösközi
Quantitation of gluten in gluten-free products is a great challenge as it is hindered by several factors including the lack of certified reference materials. To resolve this problem, our research group, in cooperation with other international experts, started a series of experiments with the goal of the production of a suitable gluten reference material. As a part of this research, several different wheat cultivars and their isolated gluten proteins were characterized by different methods, including enzyme-linked immunosorbent assay (ELISA). However, we need to know the performance of the ELISA methods used for this special area of research. During the present work we investigated the accuracy and precision of two different ELISA methods for our own laboratory conditions and special sample matrices (wheat flours and gliadin isolate). We have found that the tested performance characteristics of the methods seem to be appropriate on a case-by-case basis, but the long-term measurement uncertainty is higher, which makes it difficult to evaluate the results obtained with the ELISA method for these types of samples.
Authors:L. Hajas, K. A. Scherf, Zs. Bugyi, K. Török, E. Schall, P. Köhler, and S. Tömösközi
In special dietary products for people intolerant to gluten, gluten content is not supposed to exceed the regulatory thresholds. Enzyme-linked immunosorbent assays (ELISAs) are routinely used to quantitate gluten in these products. They measure gliadin/gluten with high specificity and sensitivity, but they have some limitations. Quantitative and qualitative variability of the target proteins among wheat cultivars is a factor that may cause inaccurate results. One of the aims of this work was to characterize the protein composition of five wheat cultivars grown in multiple harvest years and their blends by reversed-phase high-performance liquid chromatography (RP-HPLC). The gliadin/gluten content of these wheat flours was also analysed with two commercial ELISA kits. The effect of differences in protein profiles between the flours from an individual cultivar and the blend of five cultivars, harvest years, as well as processing procedures (dough forming and baking) on the results of two ELISA kits was investigated and their relative magnitude was determined. Among the factors investigated, the differences between flours had the greatest impact on gliadin recoveries.
Authors:K. Török, L. Hajas, V. Horváth, E. Schall, Zs. Bugyi, and S. Tömösközi
The weaker performance of generally used analytical methods for allergen analysis in processed foods can be connected to protein denaturation. To understand the nature of protein denaturation processes, experimental but realistic model matrices (corn starch based mixture, hydrated dough, and heat treated cookies) were developed that contain a defined amount of milk, egg, soy, and wheat proteins individually or in combination. The protein subunit composition was investigated in every processing phase, i.e. after mixing, dough formation, and baking. SDS-PAGE measurements were carried out to monitor the protein distribution of sample food matrices in non-reducing and reducing gels. The results clearly show that the highly decreased protein solubility is caused by denaturation, aggregation, or complex formation, which are the most significant factors in poorer analytical performances. Solubility can only partly be improved with the application of reducing agents or surfactants, and the rate of improvement is depending on the proteins and the matrices.
Authors:Zs Major, R Kirschner, N Medvegy, K Kiss, GM Török, G Pavlik, G Simonyi, Zs Komka, and M Medvegy
Early repolarization in the anterior ECG leads (ERV2–4) is considered to be a sign of right ventricular (RV) remodeling, but its etiology and importance are unclear.
A total of 243 top-level endurance-trained athletes (ETA; 183 men and 60 women, weekly training hours: 15–20) and 120 leisure-time athletes (LTA; 71 men and 49 women, weekly training hours: 5–6) were investigated. The ERV2–4 sign was evaluated concerning type of sport, gender, transthoracic echocardiographic parameters, and ECG changes, which can indicate elevated RV systolic pressure [left atrium enlargement (LAE), right atrium enlargement (RAE), RV conduction defect (RVcd)].
Stroke volume and left ventricular mass were higher in ETAs vs. LTAs in both genders (p < 0.01). Prevalence of the ERV2–4 sign was significantly higher in men than in women [p = 0.000, odds ratio (OR) = 36.4] and in ETAs than in LTAs (p = 0.000). The highest ERV2–4 prevalence appeared in the most highly trained triathlonists and canoe and kayak paddlers (OR = 13.8 and 5.2, respectively). Within the ETA group, the post-exercise LAE, RAE, and RVcd changes developed more frequently in cases with than without ERV2–4 (LAE: men: p < 0.05, females: p < 0.005; RAE: men: p < 0.05, females: p < 0.005; RVcd: N.S.). These post-exercise appearing LAE, RAE, and RVcd are associated with the ERV2–4 sign (OR = 4.0, 3.7, and 3.8, respectively).
According to these results, ERV2–4 develops mainly in male ETAs due to long-lasting and repeated endurance training. The ERV2–4 sign indicates RV’s adaptation to maintain higher compensatory pulmonary pressure and flow during exercise but its danger regarding malignant arrhythmias is unclear.
Authors:N. Almási, Z. Murlasits, A. Al-awar, Á. Csonka, S. Dvorácskó, C. Tömböly, S. Török, D. Bester, A. Pósa, C. Varga, and K. Kupai
Aging is a multifactorial process, which is considered as a decline over time. It is increasingly clear that there is a gender difference in aging and in the prevalence of age-related diseases as well. We aimed to examine the effects of the aging process in the colonic tissue of female Wistar rats aged 10 weeks (young) and 13 months (middle-aged) at an early stage, according to three main symptoms associated with aging: a decrease in the efficacy of the proteasome and muscle function and an increase in oxidative stress. The aging process was found to cause a significant decrease in ubiquitin C-terminal hydrolase ligase (UCHL-1) and a significant increase in 3-nitrotyrosine (3-NT), total glutathione (GSH), calcium (Ca2+), calcitonin gene-related peptide (CGRP) and superoxide dismutase (SOD) activity in middle-aged animals. In summary, it is suggested that the reduced activity of the proteasomal degradation system may be the result of the diminished expression of the UCHL-1 enzyme and the decreased levels of ubiquitin; furthermore, we found some key targets which may help to better understand the fundamental aging process.