Fulltext search in archive

Cyanobacterial water blooms became a global problem/issue because beside a dramatic deterioration of water quality parameters they also produce cyanobacterial toxins being harmful for animals and humans. Cyanotoxins especially the most prominent one, microcystin-LR (MC-LR), are of major concern and they have been reported to cause even death of mammals following ingestion or ingurgitation due to hepatotoxic modes of action. The aim of the recent study is to summarize briefly the impacts of microcystin on laboratory rodents, mice and rats, being used as models for other mammals including human beings. Most experimental approaches used intraperitoneal rather than oral and intratracheal application of microcystins, especially MC-LR, being the most efficient way to induce adverse impacts on different target organs. However, no matter how the exposure of rodents was performed, microcystins induced severe harmful impacts on the different target organs, preferentially the liver, for instances hemorrhages and apoptosis in liver, liver tumours, adverse effects on gut, kidney, testis and epididymis including spermatogenesis, on lung, on serum parameters and on progeny. In addition to these histological findings, microcystin was found to affect specifically biochemical parameters of target organs such as enzymes e.g. GST, CAT, GR, GPX, SOD, AST, ALT, γ-GT, protein phosphatases, SDH, SoDH and LDH or stress proteins such as HSP-70 and further parameters such as hepatic sulfhydryl content, GSH depletion, total bilirubin, urea nitrogen, and creatinine. Gene array analyses revealed that microcystin affects genes related to actin organization, cell cycle, apoptosis, cellular redox potential, cell signalling, albumin metabolism, glucose homeostasis pathway and organic anion transport polypeptide system. In combination with a further proteomics approach the proteomic analyses indicate that liver apoptosis induced by microcystin can be induced by two pathways: the BID-BAX-BCL2 and the reactive oxygen species pathway. The reviewed data clearly show that microcystin, especially MC-LR is able to cause severe adverse impacts on laboratory rodents and therefore there is an emerging need for further research to cover the major concern about cyanobacterial water blooms affecting mammals including human beings.

The aim of the performed research was to obtain knowledge on the ability of aquatic plants naturally growing at a site to absorb trace metals contained in bottom sediments and surface water. Furthermore, we compared differences in the accumulation of trace metals by the individual groups of aquatic plants (submerged and emergent) and assessed a possible use of the individual plant species in phytoremediation techniques. Representative samples of water, sediments and aquatic macrophytes were taken from three anthropogenically loaded streams in six monitoring cycles in several collection profiles differing in the distance from a source of contamination. The samples were analysed for the total content of selected trace metals (As, Cd, Pb, Al, Hg, Zn, Fe, Mn, Cr, Ni and Cu). For comparison, one profile at an unloaded site was sampled as well. The obtained results were subjected to multivariate statistical analysis of data. Increased contents of Fe, Al, Mn, Cr and Zn were detected in sediments and plant biomass at loaded sites, namely 2-3× higher than at the comparing site. The contents of metals in surface water samples were altogether below the detection limit of the analytical method. When evaluating the individual plant species, we can state that the lowest contents of metals were detected in shore species (reed canary grass Phalaroides arundinacea, wood club-rush Scirpus silvaticus and red dock Rumex aquaticus); plant species growing in the very water current (water star-wort Callitriche sp. and flote-grass Glyceria fluitans) exhibited mean contents of metals. In species forming mats (Fontinalis antipyretica and Cladophora sp.), these contents were several times higher as compared to the previous species. The results of the performed research show that one of important factors, which influence the accumulation of trace metals in plants, is their ecological group (emergent - submerged) affiliation and the species classification within this group. Based on the evaluated data, we can recommend species of moss and algae that form mats eventually species growing in the very water flow for the future use in phytoremediation techniques.

Although recently reported models for determining egg shape are highly accurate, certain complicated measurements or computations are to be performed. Thus relatively simple and attainable analysis methods of chicken egg shape variability were chosen and used for the purpose of presented research. Sample of 250 eggs of ISA BROWN strain was examined. Geometrical parameters were measured and calculated with following expression of their coefficient of variation - namely egg length 3.56 %, egg maximum width 2.84 %, shape index 3.80 %, surface area 5.08 %, and egg volume 7.23 %. The second method consisted in shape quantitative measuring by the score of the principal components of elliptic Fourier descriptors (EFDs). The first four principles components which could explain over 99 % of the egg shape variations were found to be very good measures of the monitored phenomenon. It was found that 87.41 % of the total shape variation can be accounted to length to width ratio. Usefulness and relevance of the shape index usage was confirmed.

Synanthedon mesiaeformis (Herrich-Schäffer, 1846) has been found in the Czech Republic and in Spain for the first time. The species was found in the south-easternmost part of the Czech Republic, near the town of Břeclav (faunistic quadrat 7267) in May 2008. The holes and pupae were found only in one, solitary growing group of trees about 20 years old. This finding place lies at a distance of more than 250 km from the localities in SW Hungary and about 550 km from the localities in eastern Poland. In June 2008, the species was found also in alders growing in the flat river alluvium on gravel sands between La Jonquera and Figueres in northern Catalonia. This locality is in a close contact with the finding places near Perpignan and Beziers in southern France. The diagnostic morphological characters and bionomics of this species are briefly summarized and figured. The history of its distribution research is recapitulated and the causes of its disjunct range are discussed as follows. The present disjunct range represents a residual of the former distribution over the warmer and moister postglacial period; landscape modifications and elimination of solitary alder trees as "weeds" from the 18th up to the mid-20th century in large areas of Europe; narrow and partly unknown habitat requirements and specific population ethology; an insufficient level of faunistic investigations in several parts of southern and eastern Europe.

Brewing is a very important part of the food industry with a successful tradition. Beer, brewer's malt and hops are important for export too. The situation in the beer market is changing dramatically at this time. Smaller local breweries are fighting with big competitors for the first time through expansion and innovation of the production line. Brewing development will be probably the same as in another European states, where are twenty big breweries to a thousand small ones. The strategy of Czech beer production is focused on the traditional production of classic Czech beer. For small breweries there are big opportunities in beer tourism, beer path building, brewery sight-seeing and brewery festivals for example.
This paper describes a particular firm's activities with using Porter's value chain and an analysis of its financial situation. In final part the Strength and Weakness analysis of the company Pivovar a sodovkárna Jihlava, a. s. is done and on the basis of the results are defined the appropriate advices.
During the recent period of time there have been many researchers from the FBE MUAF in Brno, who focused on the analysis of the food company's internal environment, e.g. Bečvářová (2005); Duda (2006, 2007); Jánský (2002, 2005); Syrovátka (2000); Veselská (2005); Zrůst and Pyšný (2007); Živělová a kol. (2004). The research on trade in food is solved firstly by Presová and Tvrdoň (2005).

The aim of this research was to assess the implications of sheep grazing for the nutritional value of the vegetation in the Mohelno Serpentine Steppe National Nature Reserve (NNR). A free pasture controlled by an electric fence was practised from 1997 to 1998. The German Merino sheep were grazing on an area of 4.25 and 6 ha with a pasture load of 6.8-9.4 sheep per 1 ha in 1997 and 6.7-8.7 sheep per 1 ha in 1998. The steppe vegetation samples were collected from five different sites reflecting the phytocenological composition typical of the individual steppe areas. The vegetation samples were collected on an area of 3×1 m² during the growing season at two-week intervals. The collected samples were tested for the amount of dry matter, fibre, nitrogenous substances, fat, ash, nitrogen-free extractive substances (NFES), gross energy (GE), metabolic energy (ME), lactation net energy (LNE), fattening net energy (FNE), PDIN and PDIE (PDI - referring to the factually digestible nitrogenous substances in the small intestine of the ruminants). During pasture there was a decrease in the dry matter levels but its average levels remained high (35.45-46.78%). The effect on the nitrogenous levels became apparent (P < 0.05) mainly in the second year of grazing (10.00-10.94% compared to 11.64-19.35% in the vegetation dry matter). However, in comparison with the pasture vegetation the effect remained less significant. A similar situation was observed in relation to the fluctuation of PDIN and PDIE (64.60-70.71 compared to 75.18-124.98 g/kg of the dry matter and 79.03-82.71 compared to 89.41-29.27 g/kg of the dry matter respectively). The fat levels (3.80-4.02%) were not affected by the site (P < 0.05) but the specific utilization. The grazing brought about a marked increase in the fat levels (P < 0.001). The amount of the fibre during the first year was affected only in terms of its decreased site variability (29.60-31.31%). The conclusive evidence (P < 0.05) of the decrease did not appear until the second year of grazing (21.76-27.88%). In the course of the pasture the ash levels identified in the dry matter were fluctuating between 8.74-10.19% depending on the site conditions and the form of utilization. Considerably high levels (P < 0.05) were recorded on more intensely grazed areas. NFES levels in the step areas (45.16-47.26%) were steady both in terms of the site conditions and the form of utilization.
The energy levels did not reflect the site variability. The ME, LNE and FNE levels (9.39-9.79; 5.52-5.80 and 5.34-5.69 MJ per kg of the dry matter respectively) were affected by the form of utilization. During the pasture the site variability of the energy levels decreased. There was also a substantial increase in the amount of energy established in the dry matter, which rose to the levels usual for pasture vegetation.

The ponds of Lednice are situated in the area "Lednicko-valtický areál", which is included in the World Heritage List of UNESCO.
The aim of this essay was monitoring of seasonal dynamic zoobenthos development in the ponds Lednické rybníky over the years 2006-2007 and performance of qualitative and quantitative analysis of taken samples. The research was realized on ponds Nesyt, Hlohovecký, Prostřední, Mlýnský and Zámecký. Samples of macrozoobenthos were taken in monthly intervals. Qualitative studies of samples have shown 112 taxa of bentic macroinvertebrates in the localities mentioned above, 17 taxa were determined for the first time. Total number of benthic macroinvertebrates taxa known in the locality Lednické rybníky rose to 316 taxa. The values of macrozoobenthos density and biomass ranged between 22-15 667 ind.m^-2 and 0.05-40.2 g.m^-2, respectively.
With respect to the fact that only few researches with a focus on quality of macrozoobenthos in ponds of Lednice were realized, this research could bring supplementary information about the situation of benthic macroinvertebrates in the studied localities in new conditions of fish farming.

Current global market is driven by many factors, such as the information age, the time and amount of information distributed by many data channels it is practically impossible analyze all kinds of incoming information flows and transform them to data with classical methods. New requirements could be met by using other methods. Once trained on patterns artificial neural networks can be used for forecasting and they are able to work with extremely big data sets in reasonable time. The patterns used for learning process are samples of past data. This paper uses Radial Basis Functions neural network in comparison with Multi Layer Perceptron network with Back-propagation learning algorithm on prediction task. The task works with simplified numerical time series and includes forty observations with prediction for next five observations. The main topic of the article is the identification of the main differences between used neural networks architectures together with numerical forecasting. Detected differences then verify on practical comparative example.

At the time of increasing globalization and homogenization of the global markets, the development of information infrastructure technology and world market becomes accessible not only to large multinational companies but also for small and medium-sized enterprises (SMEs). This has resulted in increasing competition in the domestic market which domestic firms have to face. Therefore the process of internationalization of business is a step that allows businesses performing their activities in the domestic market to enter foreign markets and to exploit the opportunities and potential which these markets offer. The paper is focused on the draft of the method for quantification of the factors, which determine the success of the SMEs in foreign markets. In the proposed method the multidimensional assessment of indicators of success of SMEs in foreign markets are used, ie. not only the proportion of sales from exports is observed, but also the profitability of international activities in an absolute and in a relative rate. Other indicators of success are the satisfaction of the company management with international activities and the success of achieving defined targets for business activities in foreign markets. Evaluation is made up of both the objective and the subjective indicators of success. Among the objective indicators of success is included the intensity of international activities of SMEs, which is detected as the sum of revenues generated from international activities in relation to total sales company, the profitability of international activities, (ie. whether the foreign activities are profitable or not), and the relative profitability of international activities, where it is ascertained whether the foreign activities generate higher profit than the activities at the domestic market. The next subjective indicator of success is the success of objectives - it was found how many objectives related to operations in foreign markets has been achieved. Another indicator is the subjective satisfaction of the company management with existing activities on foreign markets. Overall performance on foreign markets of the company is quantified using an assessment of objective and subjective indicators of success. Using the defined evaluation it will be possible to determine which of the SMEs are more and which are less successful in foreign markets. Finally, this evaluation will be used for future research aimed at identifying characteristics affecting the success of SMEs in the foreign markets.