Search Results

You are looking at 1 - 10 of 20 items for

  • Author or Editor: I. Mészáros x
  • Refine by Access: All Content x
Clear All Modify Search

Pavlov has described hypnosis as a partial sleep. A contemporary approach to this altered state of consciousness will be discussed. Under laboratory conditions subjective and behavioral data will be analyzed after hypnotic induction, shamanic trance and relaxation with listening to music. Role of different cortical regions will be shown after different hypnotic inductions as a function of hypnotic susceptibility. The importance of context will be underlined as an important factor in the possible alteration of consciousness.

Restricted access

The saline area of the Kiskunság region of Hungary has varied micro-topographic conditions with different plant communities. This study was performed in a dry sandy grassland community ( Potentillo arenariae-Festucetum pseudovinae Soó (1938) 1940) and a neighbouring saline sandy grassland community ( Lepidio crassifolii-Puccinellietum limosae Soó (1947) 1957). These are located at different elevations and have completely different floristic composition and physiognomy due to the soil characteristics and water availability. We assessed how the different environmental conditions during summer period might alter some physiological traits of two dominant xerophytes of sandy grassland ( Achillea collina L., Festuca pseudovina Hack. ex Wiesb.) and two halophytes of saline grassland ( Lepidium crassifolium (W. et K.), Puccinellia limosa (Schur) Holmbg.). The relationship between soil water potential and water content showed lower water availability for plants in the saline habitat as the high water soluble sodium content (900–2000 ppm) of this soil type limits water absorption. Both halophyte species in this study exhibited lower K/Na ratio than xerophyte species. Between the two halophytes L. crassifolium can be described as a “leaf/shoot sodium accumulator” species while P. limosa as a “leaf sodium avoider” species. The four species differed in proline accumulation. The salt adapted species had multifold accumulation of proline as compared to species of dry sandy grassland. The three microhabitats differing in total plant cover offered different microenvironmental conditions for L. crassifolium . Proline content was twice higher in leaves of this species in the microhabitats with high soil Na + content than in the closed microhabitat. Every species showed a transient reversible decrease of potential photochemical efficiency of PSII (F v/ F m ) at midday during the study period. In the saline habitat the midday depression of F v/ F m for L. crassifolium was much larger than in case of P. limosa which reflected its higher susceptibility to photoinhibition. In sandy grassland F v/ F m of A. collina was smaller than that of F. pseudovina . Mesophyll succulence index (Sm) expressing the ratio of water content to chlorophyll content was the highest in L. crassifolium (1.6–2.2 g H 2 O mg −1 Chl). Sm was low in xerophyte species (0.5–1.1 g H 2 O mg Chl), and the lowest value was found for the F. pseudovina (0.54 g H 2 O mg Chl).

Restricted access

Abstract

This paper presents the results of the floristical examinations performed in the units of a former secondary sedimentation pond system in Hungary. The outcome of analyses on the chromium content of the plants is discussed. Beside the chemical analyses, observations on the plants, the characterization of the ecological state of plant stands adapted to heavy metal load. Results of the elemental analysis for heavy metals revealed that none of the plants constituting the natural vegetation can be treated as hyperaccumulator plant. A green cover and the detoxification process of Cr(VI) by plants is suggested to be more important than the present extensive phytoextraction procedure. It can be stated that due to the disturbance our investigated area has diverse vegetation, in addition these plants can tolerate a high concentration of heavy metals, and they are able to take up them.

Restricted access

The possibilities latent in molecular marker-based QTL analyses are presented through the example of studying winter survival and heading date in barley (Hordeum vulgare L.). The whole range of QTL experiments consists of several important steps, through which answers are found to the following questions: (1) How many QTLs are involved and where do they map, (2) How does the environment influence the effect of a QTL region (environment × QTL interactions), (3) When and where are the genes determining the given trait expressed (QTL dynamics), (4) What interactions occur between these QTLs and pathways leading to specific phenotypes, and (5) How consistent is the effect of a QTL region in different genetic backgrounds and in a wider range of germplasms (comparative mapping and association studies)? This knowledge then makes it possible to continue these experiments in the direction of marker-assisted selection and/or gene isolation through marker saturation of the relevant chromosomal regions and map-based cloning. The latter can give an insight into the exact mechanism through which the gene determines the phenotype.

Restricted access

The effect of vernalization response and photoperiod sensitivity on reproductive fitness and agronomic traits was examined in a group of 16 H. spontaneum accessions and 8 H. vulgare cultivars in controlled environments. The whole range of plant developmental and agronomic traits was determined by vernalization. The reproductive fitness was severely impaired when the vernalization requirements of the plants were not saturated. Variation in the magnitude of vernalization response significantly correlated with several traits. A larger decrease in reproductive tiller number, average seed number and consequently final grain yield was more characteristic of accessions with a greater vernalization response. When the vernalization requirement was met, long photoperiod enhanced the fitness of the plants and resulted in larger yield and yield components, irrespective of the genotype, while short photoperiod acted as a limiting factor for all these traits. There was, however, a difference in the reaction type of wild and cultivated genotypes due to their different plant strategies.

Restricted access

The early growth and tillering capacity of two barley (Hordeum vulgare L.) varieties (Dicktoo and Kompolti Korai) were investigated in a gradient growth chamber. The identification of these crop traits is important under organic agricultural conditions in the selection of new varieties for competitiveness against weeds. The results clearly demonstrate that the initial development of the two barley varieties depended considerably on the plant growth conditions. The temperature gradient was found to have the greater effect during early development, causing significant differences in all the traits at all measurement dates. The results indicate that the two varieties differ substantially for two characteristics important for organic farming. As regards tillering ability, Dicktoo appears to be the more desirable type, despite the fact that it is unable to achieve its tillering potential at higher temperatures. Under certain ecological conditions, the relative temperature insensitivity of Kompolti Korai could be an advantage. As far as early development vigour is concerned, Kompolti Korai is clearly a desirable type for organic farming, since it produced rapidly growing, robust plants in all the temperature ranges. From the point of view of organic breeding, a combination of the valuable traits of these two varieties could be the way forward.

Restricted access

Tillering ability is a complex trait, the development of which is influenced by both environmental factors and complex genetic regulation. In the present experiments this complex regulation was dissected into its various components in an effort to separate the effect on tillering of major genes influencing ontogeny from that of other genomic factors. The tillering rate of a facultative × winter barley mapping population was examined in the field after autumn and spring sowing. The vernalisation sensitivity gene Vrn-H2 exerted a considerable influence on tillering in spring-sown barley. In addition to the major genes, QTL analysis revealed two chromosome regions (1HS and 3HL) with a significant influence on the extent of tillering. Neither of these regions were involved in the regulation of heading date, and their effect on tillering was the most intense at the beginning of ontogeny, gradually declining as the influence of the Vrn-H2 gene increased. The function of the Vrn-H2 locus in the regulation of tillering is manifested partly through a direct effect on the transition from the vegetative to the generative phase and partly indirectly via epistatic regulation of other chromosome regions influencing tillering.

Restricted access
Acta Physiologica Hungarica
Authors:
A. Prókai
,
J. Mészáros
,
Zs. Mészáros
,
A. Photiou
,
I. Vajda
, and
Á. Sziva

Increasing prevalence of overweight and obesity is a serious social and health problem both in the economically developed and developing countries. Despite this fact the nation-wide growth studies completed in Hungary during the past 30 years had not categorised the children either by body fat content or nutritional status. The aim of the study was to estimate the prevalence of overweight and obese boys in the country at the beginning of the new millennium.Height, body mass and four skinfold thicknesses were measured in 7173 volunteer boys aged between 7 and 10 and living in various urban and rural settlements of Hungary between 2003 and 2005. Nutritional status was qualified by the BMI and relative body fat content. The significantly increasing prevalence with age of overweight and obesity ranged between 10.3 and 23.4%. The results showed the joint effects of a secular trend of growth and of a remarkably changed lifestyle. Of these the consequences of the lifestyle are the more important ones. The high and possibly further increasing prevalence of child-age overweight and obesity reminds one of the observations of Kopp and associates (5), namely that of the increased prevalence of chronic childhood diseases during the past 15 years. More intense habitual physical activity and dramatic changes in dietary habits still promise some solution. No one should reckon, however, with the efficiency of physical education at the schools with its very few classes.

Restricted access

The prevalence of overweight or fat children and adolescents has markedly increased in Hungary during the past three decades. Among the possible factors insufficient physical activity and a relative or absolute excess of calorie intake associated to it can be regarded as the most important ones. The aim of the study was to analyse the effects of a 20-week aerobic exercise on body composition and on the exercise tested cardio-respiratory functions in 10-year-old obese boys. Obesity was defined by a BMI greater than the cut-off value reported by Cole and co-workers (5) and a relative body fat content above 30% (13). Of the study group 21 volunteer children completed the program; the contrast group contained 28 obese boys. Mean calendar age was 10.03±0.26 in the study group (S) and 9.88±0.29 in the control group (C). The members of group S had two curricular physical education (PE) classes a week and three extracurricular aerobic physical activity sessions of 60 min net time in the afternoon, on Mondays (swimming and water games), Wednesdays (folk dance) and Fridays (soccer). Group C had only 2 PE classes a week. Anthropometric and spiroergometric data were collected in the middle of January and June of 2004. Relative body fat content and BMI did not increase during the observation period in contrast to the significant increase of both in the control group. Peak minute ventilation, aerobic power, oxygen pulse, and running distance (performed on a treadmill) increased in group S, and did not change in group C.The program was considered successful despite that the changes in the observed physiological and physical indicators appeared to be slight. However, the 5-month elevated level of physical activity brought about such development in the physical status of the obese subjects that might be an appropriate basis for regular training. Fortunately, the cardio-respiratory functions of the investigated boys were not affected yet by obesity, consequently the really dramatic change in their further lifestyle exclusively depends on their decision.

Restricted access

In order to evaluate the effect of light intensity and photoperiod on heading and to establish the reaction types of barley, a set of barley germplasm of various geographical origin and growth habit was examined in a series of controlled growth chamber experiments combining two levels of light intensity with long and short photoperiod regimes. Low light intensity contributed only a limited portion to the total variance of heading and this originated to a large extent from the genotype × light intensity interaction for both photoperiods. Under the long photoperiod regime the effect of low light intensity was only apparent in a significant delay in heading. Under a short photoperiod the type of sensitivity depended on the growth habit. Low light intensity hastened plant development in 15% of the spring barley varieties, while the flowering of 44% of the winter barley varieties was significantly delayed. Establishing the reaction types for photoperiod and low light intensity in this range of barley germplasm made it possible to identify the typical reaction types of the two growth-habit groups. In addition, it also became possible to identify genotypes with contrasting or unusual combinations of these traits.

Restricted access