2957 research outputs found
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Optimizing the Cohesion of Pond Dams in Relation to the Content of Organic Matter in the Soil
Full text linkSoil organic carbon was monitored from 2013 to 2016 in two fishpond dikes of different variants of grass species composition: variant 1 - grass mix for extensively dry conditions, variant 2 - heavy duty grass mix, variant 3 - grass mix for intensively moist areas. The monitored grass vegetation was mowed twice a year. In terms of texture, the dike of Pond Rohatec is composed of sandy soil, while the dike of Pond Podhorský consists of loam to clay-loam soils. As to soil structure, the most suitable variant on the Rohatec dike proved to be the mix for extensive drought, while the best variant on the Podhorský dike was the mix for heavy duty areas. The highest organic carbon (Corg) content has been found in the above-mentioned variants. It is obvious that Corg content and suitable grass mixture thus positively affect soil structure. The dike of Pond Rohatec showed higher humus quality than Pond Podhorský, which reflected the overall more favourable composition of the dike of Pond Rohatec. These results are important as to the protection of dikes against erosion effects and for faster growth of grass mixtures.O
Multilevel Analysis of Ground Beetle Responses to Forest Management: Integrating Species Composition, Morphological Traits and Developmental Instability
Full text linkThis study evaluates the response of ground beetle (Coleoptera: Carabidae) assemblage to forest management practices by integrating species composition, body traits, wing morphology and developmental instability. Traditional approaches that rely on averaged identity-based descriptors often overlook phenotypic plasticity and functional trait variability, potentially masking species-specific responses to environmental changes. To address this, we applied a three-layered analytical approach to address this gap, utilising ground beetle occurrence and morphological trait data from Podyjí National Park, Czech Republic. The first layer assessed assemblage composition with ecological and dietary preferences across control, ecotone and clearing treatments using multivariate techniques. Building on species-level knowledge, the second layer analysed the interaction between coarse traits, such as wing morphology and fine-scale body traits, including body size (proxied by elytron length), head width and last abdominal sternite, to assess their relationship with the different treatments. These interactions were explored as intraspecific wing plasticity can affect functional interpretations. The third layer focused on fluctuating asymmetry as an intraindividual indicator of developmental instability, examining how ground beetles respond to environmental stressors. Our findings revealed: (i) no significant impact of habitat treatments on the presence of specialist species in the assemblage analysis; (ii) analysis of morphological traits highlights the combined influence of a coarse trait, such as wing morphology, and a fine trait, such as head width, which together contribute to the partitioning of assemblages and help distinguish differences in habitat use; and (iii) FA analysis revealed a significant positive association between the second antennal segment of specialist species and litter while displaying a negative association with Collembola. This multilevel analytical framework not only confirms ecological findings but also advances our approach to habitat and species analysis, offering deeper insights into ecosystem dynamics.O
From the shopping basket to the landfill: Drivers of consumer food waste behaviour
Full text linkThe EU, where nearly 57 million tonnes of food waste are generated annually, has set a target to halve this amount by 2030. However, the amount of food waste produced varies greatly between EU countries. While several EU countries are far from reaching this target, the Czech Republic already meets it. Despite this, little to no attention is paid to Czech consumers' food waste behaviour. This study responds to the unfulfilled need by drawing attention to food waste and its reduction, and possibly even serving as a model example for the EU target. We identify key factors influencing food waste by conducting a survey with 1,551 respondents on stated preferences. The results using the PLS-SEM approach show that the price of food does not have as great an impact on the level of food waste as its characteristics or planning, which is part of consumers' purchasing behaviour. Furthermore, consumers' attitudes and awareness of food waste reduce food losses. The causes of food waste remain decidedly similar before and during the pandemic COVID-19, except that people paid more attention to food attributes during the pandemic. Product attributes are an essential part of decision-making, especially for women and people with higher levels of education. We conclude that it is desirable to sufficiently educate and teach consumers to properly plan their consumption and better estimate the amount of food needed when shopping, which should be a conscious decision rather than an impulsive one.OA-hybri
Collaboration between secondary technical schools and employers
No full textCílem příspěvku je představit dílčí výsledky kvantitativního výzkumného šetření, které mapuje charakter spolupráce středních odborných škol (včetně učilišť) a zaměstnavatelů pohledem vedení škol a učitelů. Charakter spolupráce je zásadní nejen pro rozvoj středních odborných škol, ale ovlivňuje i procesy učení se na pracovišti a vzdělávací výsledky žáků. Konkrétně se v příspěvku zaměřujeme na rozmanitost a míru spolupráce a výsledky diskutujeme ve vztahu k tzv. politice založené na důkazech.The aim of this paper is to introduce the quantitative research survey results that focused on the cooperation between secondary technical schools and employers from the perspective of school leaders and teachers. The character of the employer engagement is key not only for school development, it also impacts workplace learning and learning outcomes of students. We deal with the diversity and extent of the cooperation and we discuss the partial results in the context of evidence-based policy.Published Versio
Evaluation of the effect of different thinning types on dendrometric parameters and subsequent spontaneous growth in a beech-oak-linden stand
Full text linkDue to an increasing risk of further damage to forests, forest managers are considering introducing an alternative direction for their future development - via the cultivation of mixed forests. At middle altitudes in the Czech Republic, an oak-beech-linden stand is the most natural type, and we tried to answer three main questions: (i) How the various thinning types affect dendrometric parameters and quality of the stand; (ii) How long thinning works on this stand until it loses its effect; (iii) How the stand develops spontaneously after abandonment. This experiment was conducted at the Training Forest Enterprise in the Czech Republic in Drahanská vrchovina (highlands in central Moravia). In 1988, four plots were established in a 49-year-old stand where, in three of the plots, different types of thinning (crown, low and heavy crown) were performed, leaving one (reference plot) to develop naturally. The height, the height of the crown base and diameter at breast height (DBH) were measured, and the shape and quality of the trunk and crown were estimated on each tree. Measurements were carried out in 1989, 1994, 1999, 2005, 2010, 2015, and 2020. In the first 10 years, the DBH and height of the crown base did not show any differences, and the linden at the heavy crown plot outgrew the linden trees at the other plots in height. After these 10 years, the thickest linden, the tallest beech and linden, and the greatest height of the crown base of beech and linden were all found at the heavy crown plot. The shape and quality of the trunks and crowns of beech, oak and linden were similar in all plots (including the reference plot) during the entire experiment. After thinning, the plots were left to grow spontaneously. The heavy crown thinning removed a greater number of thicker trees at the middle level, thus supporting the trees growing in the lower part of the middle level and in the below level (i.e. the beech and linden). These trees then grew more quickly compared to the others, but their quality decreased, as did that of the others. Therefore, a forest left to grow and develop spontaneously is practically unusable for commercial purposes.O
Growth, carcass and meat quality in Zwartbles lambs slaughtered at different live weights
Full text linkThe aim of the study was to evaluate the effect of different live weights at slaughter (LWS) of Zwartbles lambs on their daily gain (DG), carcass traits (CT) and chemical and physical characteristics of the quadriceps femoris muscle (QFM). A total of four weight groups of lambs were evaluated: group A, LWS = up to 35 kg; group B, LWS from 35.1 to 40 kg; group C, LWS from 40.1 to 45 kg and group D, LWS from 45.1 to 50 kg. The LWS had a significant (P < 0.05) effect on DG and most CTs, when average DG and most weights of individual CTs increased with increasing LWS. The evaluation of the influence of LWS on the chemical and physical characteristics of QFM primarily shows that this factor had a significant (P < 0.05) effect only on the content of intramuscular fat (IMF) and redness index (RI), when in both cases the values of these traits increased (IMF: from 0.57 to 1.21%; RI: from 8.53 to 9.76) with increasing LWS. In conclusion, it can be stated that most of the monitored traits in all weight groups of Zwartbles lambs were comparable with their levels in specialized meat breeds of sheep.O
Drought-tolerant hop genotypes – A promising solution to the problem of climate change for the hop industry?
Full text linkClimate change can negatively influence hop yield and its quality. Cultivation areas limited by the prohibition of using water from small water sources are most at risk. In order to prevent these areas from completely disappearing in the future, planting hops with varieties or genotypes tolerant to drought could be a promising solution. Therefore, Czech hop breeding targets drought-tolerant genotypes with high crop yield and stability of quantitative and qualitative parameters which will also be well-usable in the Czech brewing industry. Twelve promising genotypes (5165 (Uran), 5194, 5304, 5348, 5398, 5432, 5461, 5464, 5465, 5646, 5669, and 5693) were selected after measurement of their physiological parameters and their basic chemical and sensorial properties were determined. Simultaneously, they were assessed from the point of view of brewing quality using sensory and chemical analysis using a brewing test. For this purpose, experimental beer using identical decoction single-hopped technology, where a hop aroma was highlighted using hopping in a whirlpool was prepared. The results show that three genotypes belong to the category of bitter varieties (5165, 5194, and 5304), whereas the other are genotypes exhibiting the character of aromatic varieties. From a grower's point of view, genotypes 5165 (Uran), 5194, 5348, 5398, and 5461 show a very high yield. The overall impression of all beer samples is very good, bitterness is fine in most samples and hop aroma is mostly hoppy, herbal, woody, spicy, and in some cases also fruity (5304, 5461, 5465, 5646, and 5693).O
Modelling of online shopping behavior in the Czech online environment
Full text linkThe online environment has its own specifics, which shape the specific behavior of all market subjects, both customers and companies that trade electronically. The aim of the paper is to create, quantify and verify a conceptual comprehensive model of relationships between determinants that influence consumers when shopping online. The impetus for the conducted research was the discovery of the non-existence of a comprehensive model of online shopping behavior that reflects the specifics of the online environment. The main research method is the method of online questioning in the form of a questionnaire survey among a selected group of Czech respondents (n = 926) shopping online with the aim of evaluating the determinants of online shopping behavior. The results of the questionnaire survey are subsequently used to build a comprehensive model of online shopping behavior, which was statistically compiled and verified using the PLS-SEM method, which, based on statistical data, estimates the size and quality of the links between the measured (manifest) and assumed unmeasured (latent) variables. The results show that the selected factors (31 factors) explain up to 82.53% of the variability of the total variance. The results of the correlation analysis of the factors confirmed that the defined factors are not mutually dependent and that in the comprehensive model the factors are not only identified but also statistically significant. The results also confirmed that the correlation of e.g. psychological factors are stronger than dependence on other investigated factors in the comprehensive model of online shopping behavior. The research clearly showed that the key factors for customers when shopping online are Security and risk elimination (SE), together with the Online distribution and logistics (OD) and Online payments (OP). Impulsive online shopping was identified by customers as the least important factor. The validated model provides a comprehensive explanation of the current phenomenon of online shopping that integrates and extends previous studies identifying behavioral models of online shopping behavior.O
The genetic diversity and structure of the Haflinger horse population in the Czech Republic
Full text linkThe aim of the study was to describe the current state of genetic variability in the Haflinger breed in the Czech Republic using microsatellite markers, taking into consideration the numerous imports of breeding animals from abroad during the last 20 years and their impact on genetic diversity and population structure. A total of 443 horses from five countries of origin (Austria-AUT, Germany-GER, Czech Republic-CZE, Italy-ITA, and Slovakia-SVK) bred in the Czech Republic were included in the study. A set of 16 microsatellite markers for parentage control from the International Society for Animal Genetics (ISAG) was used for genotyping. The total number of alleles in individual subpopulations ranged from 53 (SVK) to 117 (CZE). The mean number of alleles per locus was 6.69. Observed heterozygosity (Ho) values ranged from 0.69 to 0.71 in all subpopulations. The most variable and informative locus (in terms of polymorphic information content-PIC) was VHL20, and the least variable was HTG6. The Fis index was mostly negative or close to 0 for all populations and was-0.033 for the whole population. The overall Fst was 0.010, indicating a low level of differentiation between subpopulations. Cavalli-Sforza and Edwards chord genetic distances were low between the CZE, AUT, and GER populations, while the ITA and SVK populations were more distinct. The results of the discriminant analysis of principal components (DAPC) and the STRUCTURE analysis indicated a high degree of admixture among subpopulations. However, three to four genetic groups were clustered. The most distant populations were ITA and SVK, which we attribute to the low number of representatives in these subpopulations. A higher level of admixture due to gene flow was observed between the populations of GER, CZE, and AUT. Higher admixtures and the discovery of more distinct genetic clusters suggest that there is more significant gene flow from the countries of origin in the population of the Haflinger breed in the Czech Republic and that there is sufficient genetic variability and diversity to suggest sufficient opportunities for more intensive breeding.O
The First Settlers of Newly Built Pools: Zooplankton and Phytoplankton Case Study in Southern Moravia
Full text linkThe biodiversity of pool ecosystems is nowadays fully dependent on building of new ones or reconstructing the damaged ones. Among the factors influencing the potential of being colonised are the habitat's local characteristics including abiotic and biotic factors. One of the most important key roles in the food chains of freshwaters play zooplankton and its high dispersal rate makes them successful colonists of new habitats. Together with phytoplankton and nutrient content development, the state and following evolution of pool ecosystem can be assessed. The aim of this study was to survey initial zooplankton succession of newly built pools and to assess the main influencers on its colonisation success. Two newly built pools (Pool 1 and Pool 4) with different morphometric characteristics were monthly sampled for zooplankton, phytoplankton and physico-chemical characteristics. Zooplankton individuals were sorted according to taxa and stage as cladocerans, copepods (adults), nauplii and rotifers; and according to size structure as follows: < 0.5 mm, 0.5-1 mm, 1-2 mm and > 2 mm. Phytoplankton species were sorted in five categories: cyanobacteria, cryptomonads, green algae, diatoms and other algae. Basic physico-chemical parameters were measured and nutrient analysis were carried out. In Pool 1, first colonists were rotifers, followed by various cladoceran taxa. Rapid increase of large cladoceran species occurred in late spring. Till the end of the survey, rotifers together with nauplii predominated. Larger copepods were constantly present since late spring. In Pool 4, first colonists were rotifers, followed by copepod nauplii which predominated till the end of survey. Larger zooplankton species peaked in summer. In the first season after inundation, the presence of a massive biomass of charophytes and subsequently green filamentous algae was crucial for the development of the communities in both pools - significantly reduced the development of phytoplankton, caused high water clarity and affected the development of zooplankton. Because there were nutrients released from the sediment nutrient pool inflicted by fertilisation of intensively farmed field, significant fluctuations in pool ecosystem were observed. Also the morphometric characteristics of the pool, such as size, shape, depth and slope of the shores indicated the suitability of the habitat for successful zooplankton colonisation.O