Social use of internet communication in the local environment of a small town

Diplomová práce "Sociální užití internetové komunikace v lokálním prostředí malého města" pojednává o sociálních aspektech užití internetu v rámci lokální každodennosti obyvatel malého českého města. V teoretické části se zaměřuje především na charakteristiku internetu jako komunikačního média a nové technologie, snaží se nalézt vztah mezi virtuálním a reálným světem, zabývá se otázkami domestikace internetu a každodennosti v kyberprostoru, ale také oblastí etnografie a její historie. Práce se dále v samostatných kapitolách soustředí na koncept publik v historickém kontextu, jejich typologii, aktivity a sociální užití médií. Zastoupena je též problematika globalizace a internetové gramotnosti. Praktická část je věnována výzkumu na základě pozorování a polostrukturovaných rozhovorů, které si kladou za cíl poodhalit specifika užití internetu v lokálním prostředí malého města.Diploma thesis "Social Use of Internet Communication in the Local Environment of a Small Town" deals with the social aspects of the internet use within the local everyday life of the inhabitants of a small Czech town. In the theoretical part, it especially focuses on the characteristics of the internet as a communication media and new technology, it tries to find the relationship between the virtual and real world, it deals with domestication of the internet and everyday life in cyberspace, and also with the field of ethnography and its history. Furthermore, the diploma thesis aims, in separated chapters, at the concept of audiences in historical context, their typology, activities and social use of media. The problems of globalization and internet literacy were also included. The practical section was dedicated to a research based on observation and semi-structured interviews which set a goal of revealing the specifics of the internet use in the local environment of a small town.Department of Media StudiesKatedra mediálních studiíFaculty of Social SciencesFakulta sociálních vě

Causes and consequences of ontogenetic dietary shifts: a global synthesis using fish models

Accepted manuscript version. Published version available at https://doi.org/10.1111/brv.12468. Ontogenetic dietary shifts (ODSs), the changes in diet utilisation occurring over the life span of an individual consumer, are widespread in the animal kingdom. Understanding ODSs provides fundamental insights into the biological and ecological processes that function at the individual, population and community levels, and is critical for the development and testing of hypotheses around key concepts in trophic theory on model organisms. Here, we synthesise historic and contemporary research on ODSs in fishes, and identify where further research is required. Numerous biotic and abiotic factors can directly or indirectly influence ODSs, but the most influential of these may vary spatially, temporally and interspecifically. Within the constraints imposed by prey availability, we identified competition and predation risk as the major drivers of ODSs in fishes. These drivers do not directly affect the trophic ontogeny of fishes, but may have an indirect effect on diet trajectories through ontogenetic changes in habitat use and concomitant changes in prey availability. The synthesis provides compelling evidence that ODSs can have profound ecological consequences for fish by, for example, enhancing individual growth and lifetime reproductive output or reducing the risk of mortality. ODSs may also influence food‐web dynamics and facilitate the coexistence of sympatric species through resource partitioning, but we currently lack a holistic understanding of the consequences of ODSs for population, community and ecosystem processes and functioning. Studies attempting to address these knowledge gaps have largely focused on theoretical approaches, but empirical research under natural conditions, including phylogenetic and evolutionary considerations, is required to test the concepts. Research focusing on inter‐individual variation in ontogenetic trajectories has also been limited, with the complex relationships between individual behaviour and environmental heterogeneity representing a particularly promising area for future research

Long-term monitoring of fish in a freshwater reservoir: Different ways of weighting complex spatial samples

Anthropogenic activities continue to pose the greatest challenges to freshwater ecosystems. Therefore, long-term monitoring is essential for the management and conservation of these resources. Monitoring programs for freshwater bodies often use a range of indicators, including biological elements such as fish. Existing European standard provides a depth-stratified gillnet sampling approach mainly in benthic habitats and at the deepest part of lakes to account for the uneven distribution of fish. However, the commonly used CEN (European Committee for Standardization) protocol does not weight sufficiently habitat volumes and underrepresent pelagic habitats to calculate whole-lake catch and biomass per unit effort (CPUE and BPUE, respectively). Extended European standard gillnet (4 larger mesh-sizes added in the geometric series) catch data collected over 18 years (2004–2021) in Římov Reservoir (Czech Republic) were used for a method comparison on indices for relative abundance and biomass of fish: CEN protocol without volume-weighting and two volume-weighted approaches. We also evaluated changes in species composition and trends in these fish population over time. Results indicated interannual changes in species composition, relative abundance, and biomass of fish community. The CEN protocol tended to put greater emphasis on benthic habitats which generally have larger CPUE and BPUE. Consequently, the two volume-weighting approaches produced lower estimates of the two parameters, with the exception of the most dominant pelagic bleak Alburnus alburnus (L.). All approaches consistently showed an increasing trend in whole-reservoir fish abundance and a decreasing trend in biomass over the study period. Following our assessment, we put forward the volume-weighting approach that considers the Volume of the depth Stratum (VOST) for weighting as the most realistic approximation of fish populations and therefore recommend its use

Forms of phosphorus, aluminium, and iron in soils of catchments of acidified mountain lakes

The thesis assesses forms of phosphorus, aluminium, and iron in soils of catchments of acidified mountain lakes. The aim of the study was to determinate changes in soil chemistry in catchments of Bohemian Forest lakes between years 2000 and 2010. The next aim was to compare fractionation according to Psenner and Pucsko (1988) with standard pedological extractions

Biodegradation of Crude Oil Hydrocarbons in Groundwater by Permeable Reactive Barriers

This work represents the grant application for project dealing with biodegradation of crude oil hydrocarbons in groundwater by permeable reactive barriers. The project is focused on the optimalization of nutrient supply and residence time for the two pilot permeable reactive barriers

The Function and Meaning of Nonverbal Communication in Television News Based on the Example of Newscasters in Czech News Broadcasts

The Bachelor's thesis "The Function and Meaning of Nonverbal Communication in Television News Based on the Example of Newscasters in Czech News Broadcasts" deals with nonverbal means of communication used by the newscasters on the three nationwide Czech TV channels (CT1, Nova, Prima) and their main news programs. In the theoretical section, the work focuses on the definitions and classification of nonverbal phenomena, on news and its fundamentals, and last but not least on the definitions and roles of the newscaster within the news. The practical section presents research on particular nonverbal phenomena and makes an effort to answer the preset hypotheses

Effect of submerged macrophytes on the structure of lake ecosystem and trophic relationships among fishes

This Ph.D. Thesis is focused on the effect of submerged vegetation on the structure of lake ecosystem and trophic relationships among fishes. Succession of submerged vegetation is a dynamic process and the vegetation community may change dramatically even during a year. Many environmental factors have impact on the succession of submerged vegetation and consequently the presence of the vegetation has substantial impact on the aquatic ecosystem. Nutrient level (mainly nitrogen and phosphorus) plays a key role in the succession of freshwater ecosystems. Further, herbivory significantly influences species composition and biomass of macrophytes and macroalgae. Herbivory of fish is a foraging strategy that is dependent on temperature. Foraging preferences of fish may suppress the palatable species. The rate of herbivory affects plant growth patterns and thus inpalatable species may be advantaged in the competition among plants. In aquatic ecosystems, herbivory is often performed by omnivorous species. The diet preferences of omnivorous fish differ among aquatic ecosystems and submerged vegetation can shape their trophic niches substantially

Social use of internet communication in the local environment of a small town

Diploma thesis "Social Use of Internet Communication in the Local Environment of a Small Town" deals with the social aspects of the internet use within the local everyday life of the inhabitants of a small Czech town. In the theoretical part, it especially focuses on the characteristics of the internet as a communication media and new technology, it tries to find the relationship between the virtual and real world, it deals with domestication of the internet and everyday life in cyberspace, and also with the field of ethnography and its history. Furthermore, the diploma thesis aims, in separated chapters, at the concept of audiences in historical context, their typology, activities and social use of media. The problems of globalization and internet literacy were also included. The practical section was dedicated to a research based on observation and semi-structured interviews which set a goal of revealing the specifics of the internet use in the local environment of a small town

Distribution of herbivorous fish is frozen by low temperature

The number of herbivores in populations of ectothermic vertebrates decreases with increasing latitude. At higher latitudes, fish consuming plant matter are exclusively omnivorous. We assess whether omnivorous fish readily shift to herbivory or whether animal prey is typically preferred. We address temperature as the key factor causing their absence at higher latitudes and discuss the potential poleward dispersion caused by climate changes. A controlled experiment illustrates that rudd (Scardinius erythrophthalmus) readily utilize plant matter at water temperatures above 20 °C and avoid its consumption below 20 °C. Field data support these results, showing that plant matter dominates rudd diets during the summer and is absent during the spring. Utilizing cellulose requires the enzyme cellulase, which is produced by microorganisms growing at temperatures of 15-42 °C. Water temperatures at higher latitudes do not reach 15 °C year-round; at our latitude of 50°N~150 days/year. Hence, the species richness of omnivorous fish decreases dramatically above 55° latitude. Our results provide support for the hypothesis that strict herbivorous specialists have developed only in the tropics. Temperatures below 15 °C, even for a short time period, inactivate cellulase and cause diet limitations for omnivorous fish. However, we may expect increases in herbivory at higher latitudes caused by climate change