National Repository of Grey Literature 8 records found  Search took 0.02 seconds. 
Změny ve vývoji hltanových žláz a obsahu celkového proteinu v hemolymfě dělnic včely medonosné
Babica, Ondřej
This thesis is focused on developmental specifics of honeybees emerged during the season and on monitoring the differences between weak, medium and strong honeybee colonies. The level of the total haemolymph protein appears to be an important indicator of worker bee condition and signals of the occurrence of the winter generation of bees. The level of the total haemolymph protein of bees emerged in August was several times higher than the protein level of bees hatched from May to the end of July. The strong colonies showed the highest values of total haemolymph protein. The size of the hypopharyngeal glands (HPGs) indicates the biological aging of the workers and development of the bee colony during season. Nurses were characterized by the most developed HPGs, and foragers had HPGs atrophied. Bees emerged in the late summer had more developed HPGs. These physiological parameters are influenced by the division of labour in dependence of temporal and biological polyethism.
Hodnocení jakostních parametrů kozích jogurtů v závislosti na vstupní surovině
Němcová, Vendula
The aim of the work was to evaluate the physico-chemical and microbiological parameters of organic goat yoghurts and milk, which was used for their production. The results were evaluated depending on the season and storage time of yoghurts. Sampling took place during spring, summer, autumn and winter. The sampling schedule during storage was chosen according to the shelf life given by the producer with the possibility of extending the shelf life of the product. The evaluated parameters included dry matter, fat, protein and lactose content, titratable and active acidity and microbiological analysis (total number of microorganisms, lactic acid bacteria, psychrotrophic microorganisms, coliform bacteria, enterococci and micromycetes). Goat's milk and, depending on it, yoghurts were subject to seasonal changes in composition with a higher dry matter content in winter and lower in summer. These differences were also reflected in the different titratable acidity and the total number of microorganisms. No coliform bacteria were present in the yoghurts. Enterococci, psychrotrophs and micromycetes (mostly yeasts) have been reported. Between the 3rd and 13th day of storage the number of psychrotrophs and micromycetes increased significantly. For yeasts and molds, another significant increase followed between the 18th and 24th day of storage. Only slight post-acidification was observed during yoghurt’s storage.
Ecophysiology of peat bog ericoid subshrubs - freezing resistance and water relations
Daněk, Michal ; Sklenář, Petr (advisor) ; Hájek, Tomáš (referee)
The seasonal changes in freezing resistance and water relations in four dwarf shrub species of Ericaceae family: Vaccinium vitis-idaea, V. myrtillus, V. uliginosum and Oxycoccus palustris in two study areas differing in altitude were studied in this work. To establish the freezing resistance, the plants were sampled eight times, to determine parameters of the water relations, the plants were sampled six times during the growing season of 2009. For the freezing resistance examination, ice nucleation temperature (exotherm) and 50 per cent lethal temperature (LT50) were found. The water relations were described using the parameters derived from the pressure-volume curves: osmotic potential at full turgor, osmotic potential at zero turgor, cytoplasmic water fraction, relative water content at turgor loss and bulk modulus of elasticity. An important seasonal variability in the freezing resistance was found. The highest levels of the freezing resistance were reached in the spring and in the autumn, the lowest levels were found in the summer. There were also changes in the used mechanisms of the freezing resistance - for most of the year, the plants were tolerant, they showed the avoidance mechanism only in the summer. The seasonal changes in the water relation parameter were less unambiguous. The most of...
Seasonal changes of water quality in reservoirs of the Litovecko-Šarecká cascade
Stegarescu, Rodica ; Komínková, Dana (advisor) ; Benešová, Libuše (referee)
This diploma thesis deals with monitoring of water quality in the reservoirs which form the Litovicko- Šárecká cascade. It is a cascade of ponds, waterworks and retention reservoirs situated on the Litovicko-Šárecký stream and is composed of 9 major reservoirs. These reservoirs have different functions: from landscaping, retention, biological as well as recreation: fishing and swimming. Many of these reservoirs flow through human settlements, which have a negative impact on the quality of water within the whole cascade. The goal of this thesis is to monitor physical and chemical indicators of water as well as to determine the composition of phytoplankton populations, assess the state of water depending on the human activities in the basin and also to monitor how has the water quality changed in time and what are the main pollution sources. The water quality was determined from 11 samples collected with monthly intervals during March 2012 to May 2013. Samples were collected on all the reservoirs from the inflow, in the middle and at the outflow for chemical analysis and only from the middle for biological analysis. The following indicators were monitored: temperature, pH, conductivity, dissolved oxygen, indicators of neutralization capacity (ZNK8.3 a KNK4.5), hardness, CODMn, the concentration of...
Ecophysiology of peat bog ericoid subshrubs - freezing resistance and water relations
Daněk, Michal ; Sklenář, Petr (advisor) ; Hájek, Tomáš (referee)
The seasonal changes in freezing resistance and water relations in four dwarf shrub species of Ericaceae family: Vaccinium vitis-idaea, V. myrtillus, V. uliginosum and Oxycoccus palustris in two study areas differing in altitude were studied in this work. To establish the freezing resistance, the plants were sampled eight times, to determine parameters of the water relations, the plants were sampled six times during the growing season of 2009. For the freezing resistance examination, ice nucleation temperature (exotherm) and 50 per cent lethal temperature (LT50) were found. The water relations were described using the parameters derived from the pressure-volume curves: osmotic potential at full turgor, osmotic potential at zero turgor, cytoplasmic water fraction, relative water content at turgor loss and bulk modulus of elasticity. An important seasonal variability in the freezing resistance was found. The highest levels of the freezing resistance were reached in the spring and in the autumn, the lowest levels were found in the summer. There were also changes in the used mechanisms of the freezing resistance - for most of the year, the plants were tolerant, they showed the avoidance mechanism only in the summer. The seasonal changes in the water relation parameter were less unambiguous. The most of...
Influence of leaf age on the Rubisco content
Matulková, Zuzana ; Zemanová, Jana (referee) ; Hrstka, Miroslav (advisor)
The bachelor’s thesis describes the influence of leaf senescence on the Rubisco enzyme content in Fagus sylvatica, grown both in normal and elevated athmospheric carbon dioxide concentration. Tha samples were collected at the Station of experimental ecology, Institute of systems biology and ecology, Academy of Sciences of the Czech Republic, White Cross in Moravian-Silesian Beskydy. To specify the determination three series of samples were taken in following order - the first one on 22nd May 2007, the second one on 24th July 2007, and the third one then on 4th September 2007.The Rubisco enzyme content in leafs was measured by the SDS-PAGE method. In Fagus species grown in elevated carbon dioxide concentration we observed the depression of Rubisco enzyme content during the vegetation period. Reversely in Fagus species grown in normal carbon dioxide concentration the Rubisco enzyme content was increasing.
Seasonal evolution of antibiotic concentrations in the wastewater of STP České Budějovice
JANOŠÍK, David
The aim of the diploma thesis was to monitor seasonal concentration changes of 7 antibiotics norfloxacin, levofloxacin, ciprofloxacin, azithromycin, erythromycin, trimethoprim and sulfamethoxazole in wastewater influent and (cleaned) water effluent in the Sewage Treatment Plant (STP) České Budějovice. Time-proportional 24 hours pooled samples of wastewater were collected every month from March 2011 to February 2012 in the influent and effluent pof the STP. The concentrations of target compounds were determined by using in line SPE/LC-MS/MS analysis. The highest average concentration in the influent was detected in case of norfloxacin (0.563 microgram/l) and ciprofloxacin (0.406 microgram/l). The highest average concentration in the effluent was detected in the case of trimethoprim (0.255 microgram/l) and erythromycin (0.117 microgram/l). Higher concentration of antibiotics was measured in the colder periods of the year. It was connected with increased use of antibiotics and with less cleaning efficiency of the STP in this season. The highest removal efficiency was determined for norfloxacin and ciprofloxacin, the lowest for erythromycin. The influence of the season on the removal efficiency of antibiotics was found esp. for azithromycin,trimethoprim and sulfamethoxazole.
Seasonal changes in populations of soil tardigrada in dependence on humidity and temperature changes
HAVLIŠOVÁ, Tereza
Aim of this study was observation of soil tardigrada populations in Hosín in south Bohemia. The research took place in three different localities (meadow, fallow and forest) where the distribution of species was defined. We examined the abiotic factors and their influence on abundance, size of the subjekt and seasonal dynamic of populations.

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