National Repository of Grey Literature 19 records found  1 - 10next  jump to record: Search took 0.00 seconds. 
Assessment of asp reproductive population in Švihov Reservoir in 2017
Šmejkal, Marek ; Blabolil, Petr ; Bartoň, Daniel ; Kolařík, T. ; Soukalová, Kateřina ; Děd, Vilém ; Boborová, K. ; Michalička, P. ; Zemanová, Z. ; Kočvara, Luboš ; Duras, J. ; Kubečka, Jan
The aim of the contract was to capture reproducing asp by electrofishing and tag fish individually using individual marking technique (PIT-tags). Estimate of asp reproductive population in the Švihov Reservoir was performed on the basis of mark-recapture methods. Furthermore, the length and weight increments were computed for recaptured asp individuals. Tagged individuals were monitored using passive telemetry systems on the tributary of Švihov Reservoir.
Three years long investigation of fishpond Dehtář - first fishpond in the NETLAKE COST action project
Potužák, Jan ; Šumberová, Kateřina ; Fránková, Markéta ; Fabšičová, Martina ; Ducháček, M. ; Císař, K. ; Duras, J.
In 2014–2016 we monitored basic environmental parameters in the fishpond Dehtář near České Budějovice (Czech Republic) using system of sensors. Among other parametres we studied for instance water chemistry and phyto- and zooplankton community biomass, and species composition. Thank to the method used we recorded strong fluctuations in some of the environmental parameters, parrticularly in oxygen concentrations. Thank to the integration of the auomatic high frequency monitoring using the sensor system along with traditional research methods we were able to interpret the marked ecosystem changes. Several factors participated in the several days long oxygen depletion: warm and calm weather, later interchanged by cold front accompanied with mixing of water column and cloudy sky, fish farming management (high amount of nutrients related to manuring) and changes in biomass of phytoplancton (fast decomposition of high biomass amount of cyanobacteria). Our results enable to prevent similar situations in future, by e.g. lowering of nutrient input.
Long-term trends in water quality of pond Světin relation to fish management
Altmann, Martin ; Duras, Jindřich (advisor) ; Vrba, Jaroslav (referee)
Fishpond ecosystems provide many other services besides fish production. One of them is the retention of nutrients and thus ability to change the quality of the through flowing water, thereby ability to influence the overall quality of surface waters. In the case of the fishpond Svět in Třeboň it is also recreation, as the pond is an integral part of the tourism of the town. Water quality in the fishpond and its retention capacity of phosphorus is connected with the fish management and the inflow of nutrients from the catchment basis, especially within a cascade of ponds and densely populated or agricultural regions. This thesis evaluates seasonal (2013, 2015) and long term (2007-2015) trend of water quality of pond Svět in Třeboň in relation to fish management. Furthermore, mass balance was calculated for 2015 and estimated for 2013. The years 2015 and 2013 (the first years of production cycle) varied considerably in amount of annual rainfall. The year 2015 was extremely dry and 2013 very aqueous. Different hydrological conditions caused different seasonal courses in hydrochemistry parameters and its concentrations. The water quality of fishpond Svět is in the most of parameters better in comparison with other production fishponds in the Třeboň region and also the intensity of fish management is...
Growth of aquatic vegetation in fish ponds used for recreation - Bolevecká soustava near Plzeň.
Pták, Martin ; Duras, Jindřich (advisor) ; Potužák, Jan (referee)
The aim of this diploma thesis was to clarify the differences among three different ponds (Bolevecký, Třemošenský, Šídlovský) situated in Pilsen. All of the above mentioned ponds are recreational areas where Bolevecký pond is best known for his water quality improvements since 2006 (after application of Fe and Al - colagulants and also fish - stock changes). The main difference was based on the growth of submersed water plants. The macrophytes were growing slowly or not at all in Bolevecký pond. There was a huge expansion of macrophytes (mainly Myriophyllum spicatum species) in Třemošenský and Šídlovský ponds therefore the water plants must be regulated during summer seasons by mechanical harvesting. The water in all three ponds proves the same qualities but the differences may be found in the nutrient composition of sediments. The fractionation analysis (the founders Psenner and Puczsko) confirmed the fact that all localities are poor in phosphorus however the differences were found in content of iron. The increased content of iron was observed in sediments of Šídlovksý and Třemošenský ponds (mainly in BD fraction - the iron was unstable under redox potential changes). The result of this analysis proves that phosphorus is potentially more available for macrophytes in sediments of Třemošenský and Šídlovský...
Prediction methods of protein hot spots
Duras, Jan ; Provazník, Ivo (referee) ; Maděránková, Denisa (advisor)
This master's thesis deals with prediction of hot spots in proteins. The theorethical part describes compositions of proteins interfaces and hot spots. There are mentioned basic principles of hot spots prediction. In the practical part is selected method, using the S-Transform, designed to pseudocode and then implmented to Matlab software. Created program is tested on a sample of data and compared with available methods.
Fishpond sediment – new approach to the nutrient recycling in the agricultural landscape
Potužák, Jan ; Duras, J. ; Kröpfelová, L. ; Šulcová, J. ; Chmelová, I. ; Benedová, Z. ; Svoboda, T. ; Novotný, O.
Possibilities of the use of the fishpond sediment in the improvement of arable land is discussed. Among others, this approach has a high potential to contribute to the recycling of phosphorus in the agriculture landscapes. For this purpose, we propose set of particular techniques which were tested in the field study.
Fishponds and water quality
Duras, J. ; Potužák, Jan ; Marcel, M.
Most of the fishponds in the Czech Republic is highly eutrophic to hypertrophic. This situation is related to the run-off in the catchments and by the fis-farming management (especially fertilisation). Long-term monitoring of fishpond water quality is complicated by large spatiotemporal variability of the parameters measured.
Assessment of vulnerability of water reservoirs to sediment loads and eutrophication caused by soil erosion
Krása, J. ; Rosendorf, P. ; Hejzlar, Josef ; Borovec, Jakub ; Dostál, T. ; David, V. ; Ansorge, L. ; Duras, J. ; Janotová, B. ; Bauer, M. ; Devátý, J. ; Strouhal, L. ; Vrána, K. ; Fiala, D.
This methodology has the following aims: Allow any investigator to evaluate the erosion and transport of sediment phosphorus in large river basins. Allow investigators to estimate the importance of erosion for the eutrophication of the target reservoir. Allow investigators to estimate the importance of other sources of phosphorus in the watershed. Allow investigators to estimate the behavior of the other tanks in the current state of phosphorus loads from the watershed. The methodology is focused on solutions in large river basins.

National Repository of Grey Literature : 19 records found   1 - 10next  jump to record:
See also: similar author names
1 Duras, J.
3 Duras, Jan
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