National Repository of Grey Literature 17 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Speciation analysis of As and Hg in biological material
Petry-Podgórska, Inga ; Matoušek, Tomáš ; Migašová, M. ; Zemanová, Veronika ; Pavlík, Milan ; Pavlíková, D. ; Kratzer, Jan
This work was focused on an analysis of arsenic in selected plants and mercury in hair. A combination of HPLC and ICP-MS was used for analysis of biological tissues extracts. The\nspeciation analysis of low molecular arsenic and mercury species like inorganic iAs3+ and iAs5+, methylarsenic and dimethylarsenic forms was carried out with hydride generation (HG)\ntechnique, arsenic peptides and inorganic mercury (iHg2+) and its methylated form (MHg+) - with reverse phase (RP) chromatography and detected by ICP-MS.
The effect of cadmium on oxidative stress in plants
Zemanová, Veronika ; Pavlíková, Daniela (advisor) ; Tomáš, Tomáš (referee)
The two ecotypes of Noccaea caerulescens originating from two differently contaminated sites (Redlschlag, Austria; Ganges, France), N. praecox (Mežica, Slovenia), Arabidopsis halleri and Spinacia oleracea were studied to compare Cd accumulation and tolerance. After 30, 60, 90 and 120 days of cultivation in Cd contaminated soil (30, 60 and 90 mg Cd/kg soil) for hyperaccumulators and 25, 40, 55 and 75 days of cultivation in Cd contaminated soil (30, 60 and 90 mg Cd/kg soil) for spinach gas-exchange parameters (net photosynthetic rate, transpiration rate, stomatal conductance, intercellular CO2 concentration), fatty acids, macro- and microelements were determined as well as N utilization by plants. Noccaea species and A. halleri showed similar changes in yield of biomass, Cd content and total content of amino acids. These species confirmed differences in the profile and contents of individual free amino acids. The comparison between Noccaea species showed that Cd stress resulted in similar changes of gas-exchange parameters. Contrasting responses of plants to Cd contamination were confirmed in macro- and microelements contents, fatty acids and amino acids metabolism. Spinach showed contrasting response to cadmium compared to hyperaccumulators, especially in profile of free amino acids and fatty acids.
Plants containing toxic substances in the garden of nursery schools
Pilařová, Kateřina ; Pavlíková, Daniela (advisor) ; Jitka, Jitka (referee)
This thesis is focused on the occurrence of poisonous plants in gardens of nursery schools, assesses the level of danger to children and awareness of teachers who ensure the safety of children during their stay in the nursery schools. Attention is paid to individual groups of plant toxic compounds. Reactions of the organism to their presence, including examples of poisoning caused some of them, and a first aid for intoxications are discussed. Mentioned are the most dangerous plants with possible occurrence in our geographical conditions, and esp. those that can entice children by an attractive appearance of some of their parts (flowers, fruits, etc.). It also includes a statistical analysis of the incidence of poisonous plants in gardens of nursery schools and the awareness of educational supervision. The conclusions of the investigation indicates that in gardens of nursery schools are often found large quantities of various dangerous plants containing toxic substances and children use for their games some parts of such plants. Although the evaluation of the actual toxicity of the plants is very difficult, there's no space for underestimating this danger and it is appropriate that teachers recognize poisonous plants. Toxic plant substances have high biological activity in low doses. This work should serve as a basis for creating material for purposes of public health surveillance in schools and school facilities and manuals directly for the needs of schools, because gardens of nursery schools are due to young age, intellectual capacity and a high number of children the riskiest place for the possibility of poisoning.
The Effect of Environmental Contamination on Quality of Leafy Vegetables
Jančíková, Silvie ; Pavlíková, Daniela (advisor) ; Veronika, Veronika (referee)
Heavy metals are widely distributed throughout the environment, but environment can be contaminated by these elements originated from anthropogenic activities. These toxic elements can be taken up by plant. Heavy metals accumulation and their uptake by plants depend on plant species, plant growing period, part of plant, soil characteristics (content of organic matters, physical chemical properties), interactions between metals etc. High concentrations of metal ions in plants can result in metabolic stress and so the plant metabolic stress mechanism can be induced : organic acids exudation, heavy metals binding in cell walls, phytochelatins synthesis etc. In case, that various protective mechanisms against toxic elements are not successful, heavy metals cause the damage to plant metabolism. This is indicated by changes in the contents of amino acids and fatty acids, enzymatic changes, inhibition of yield of aboveground biomass, chlorosis of leaves. There is an important difference between Zn and the other elements. Zn is an essential micronutrient and its content in contrast to the other elements without biological function is less toxic for plants. Vegetables are rich sources of essentials nutrients and heavy metals can significantly affect their quality. The consumption of contaminated vegetables may result in negative effects on nutritional composition. Leafy vegetables have relatively higher concentrations and transfer factors of heavy metals in contrast to root and fruit vegetables. There is the high health risk to consume the vegetable which is exposure to heavy metal polluted environment. The majority of European agricultural soils is safe for food production, but the areas with the high population density (China) have level of contamination which present ecological and health risk. For this reason many studies have focused on crop accumulation of heavy metals in such areas.
Chicane at Primary Schools and it Social Aspects
Chicane is an up-to-date social problem which very often appears as a hidden phenomenon and it is difficult many times to be revealed and solved subsequently. This Diploma Work points out to the chicane problem area in broader context. The main goal of the Work is to compare the chicane occurrence at primary schools in the regional city and other local towns with population number up to one thousand five hundred inhabitants. A factual investigation focus is based on a long-term cooperation with the SOS Archa Centre which implements preventive programmes at primary schools in Plzeň and the Plzeň Region. Results of the investigation provide a statement of present status of the chicane problem area in the region and at the same time they discover the riskiest group of pupils who a successive intended focus of the preventive programmes shall be aimed at. Theoretical part of the Work defines the term ``chicane{\crqq}, it describes its evolutionary phases, its exposures, characteristics of aggressors and victims as well as possible chicane consequences. Further on, it outlines appropriate steps leading to chicane analysis and its precaution. From the sociology point of view, a quantitative research was carried out and a method of anonymous questionnaire was used for data collection. Any obtained data were processed in the way of secondary analysis. Pupils of the first and second stage of two primary schools in the regional city and two primary schools in local towns whose population number is below one thousand five hundred presented an essential file of the research. It resulted from the research there were more children involved in chicane in a smaller town than in bigger one. Herewith the original hypothesis was refuted. The research results showed subsequently that the riskiest group endangered by chicane were boys of the second stage of primary school in local towns. The research will be used by the SOS Archa Centre for targeted and natural integrating of the above preventive programmes of schools.
Changes in cytokinin contents and metabolism in spinach in response to zinc excess in soil
Žižková, E. ; Gajdošová, Silvia ; Pavlíková, D. ; Pavlík, Milan ; Száková, J. ; Motyka, Václav
Changes in endogenous cytokinin (CK) contents and metabolism in spinach (Spinacia oleracea L.) responding to excessive amounts of zinc in soil were studied. Application of three zinc rates in soil (250, 500, 750 resulted in a progressive (1.7- to 3.3-times) increase of endogenous CKs in spinach leaves. This increase was predominantly due to accumulation of inactive and storage CK forms (N- and O-glucosides) and was accompanied with an enhanced activity of cytokinin oxidase/dehydrogenase (CKX), the key CK degradative enzyme, especially on the highest zinc rate (750 soil). On this rate, maximum endogenous CK concentrations in both control and stressed plants were found at the first and the last samplings, i.e. in the course of very young leaf development and just before or during flowering. The CKX activity of stressed plants exceeded that of controls during the whole development and reached the maxima at the last sampling of treated plants.
The effect of fertilizer application system CULTAN on content of sterols in aboveground maize biomass
Pavlík, Milan ; Pavlíková, D. ; Balík, J. ; Najmanová, J.
The results of free β-sitosterol analyses showed its increasing concentration after injected UAN application in contrast to ammonium nitrate (AN) treatments. The concentrations of free β-sitosterol in plants growing on urea ammonium nitrate solution (UAN) treatments were increased more than 100% during 13 days after fertilizer application. Our results confirmed that sterol interconversions are controlled by environmental conditions and they are involved in the regulation of membrane properties in response to changing growth conditions.
The effect of fertilization by nitrogen on leaves of free amino acids in plants
Neuberg, M. ; Pavlík, Milan ; Balík, J. ; Kaliszová, R. ; Pavlíková, D.
The effect of different fertilization systems, especially CULTAN (Controlled Uptake Long Term Ammonium Nutrition), on levels of selected amino acids (alanine, glycine, serine, asparagine and glutamine) was investigated in this study. As modeling plant was used maize (Zea mays L.; hybrid Rivaldo) and levels of amino acid were measured by GC-MS. We found significant difference in the levels of certain amino acids. Concentration of alanine and glutamine was higher by treatment with urea ammonium nitrate solution (DAM 390) compared with individuals treated by ammonium nitrate.
The phosphorus role in plants
Pavlíková, D. ; Pavlík, Milan ; Balík, J.
Phosphorus play very important role in plant metabolism. It is active as energy transporter and important structural component. Phosphate is relatively unavailable to plant roots. Thus plants have evolved several strategies for obtaining P from the soil. They can modify root structure and function, excrete root exudates helping with solubilization of P compounds in root rhizosphere.

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6 Pavlíková, D.
1 Pavlíková, Denisa