|
|
Variability of home ranges and territory sizes in birds
Holubová, Kateřina ; Storch, David (advisor) ; Sedláček, Ondřej (referee)
Territories and home-ranges are the smallest spatial units of species' presence in a landscape and they determine in what ways and on what scales animals perceive and use their environments. Their sufficient sizes encompassing enough resources are critical for survival and reproduction of individuals. Processes and factors affecting territory and home-range sizes therefore belong to fundamental ecological issues. Despite its importance, the knowledge of variation in avian territory and home-range size at large spatial scales is poor. So far it has comprised mainly the findings that the used area is determined by individual's energetic demands, dependent on body size and diet type, and by environmental productivity. Therefore, the aim of this thesis was to use data gathered from available literature to describe the variation in territory and home-range size of birds. I was curious what was the nature of territory and home-range size frequency distribution; whether the sizes were species-specific and whether and how these sizes were affected (beside the body mass and diet type) by various environmental characteristics, such as latitude, temperature, precipitation, seasonality, altitude and habitat type. I have found that the territory and home-range size frequency distribution is approximately...
|
|
|
Long-term population trends of birds in North America and Europe: a metaanalysis of existing studies
Říhová, Jana ; Reif, Jiří (advisor) ; Voříšek, Petr (referee)
Since the beginning of the last century there have been significant changes in the environment, farming and the landscape structure. Because birds are one of the longest- studied groups of organisms and are considered to be good indicators of environmental quality, it is advisable to relate environmental changes to changes in bird abundance. Understanding these relationships enables better and more accurate formulation of conservation plans and priorities, and therefore a large number of studies were dedicated to them. Although these studies achieved great progress in the knowledge of the most important factors that affect bird populations, their findings remained somewhat incomplete and fragmentary due to their limited temporal and/or spatial coverage. Therefore, it was not entirely clear which patterns are general and which are confined to some specific regional conditions. The fill this knowledge gap, I collected all studies on long-term trends in bird abundance in Europe and North America, which I was aware of, and made a meta-analysis of their results. Using linear mixed-effects models, I found a significant decrease in open-habitat species, probably as a result of agricultural intensification and abandonment of agricultural land. This pattern was consistent regardless of region or time period...
|
|
|
The Effect of Distance on International Trade: A Meta-Analysis
Tlustá, Anna ; Havránek, Tomáš (advisor) ; Zeynalov, Ayaz (referee)
Over the time the effect of distance has became an essential component for understanding international trade flows. The main goal of my bachelor thesis is to collect specific data from each study concerning the distance effect and design meta-analysis based on this dataset. I build my work on the data published by Anne-Celia Disdier and Keith Head (The puzzling persistence of the distance effect on bilateral trade) that were relevant in 2006. I examine 1470 estimates reported in 130 studies. Since the previous meta-analysis does not include all required methods to reveal the publication bias, I focus mainly on this issue by incorporating all the appropriate tests. Finally, I disprove the argument that distance effects on bilateral trade decline over time and I explain the presence of heterogeneity among the estimates. 1
|
|
| |
|
|
Price Elasticity of Alcohol Demand: A Meta-Analysis
Fanta, Nicolas ; Havránek, Tomáš (advisor) ; Zeynalov, Ayaz (referee)
The own-price elasticity is considered to be one of the key factors describing the demand for alcohol. There have been many estimates computed by now but only a few studies tried to analyse them. The aim of this meta-analysis is to discover more about the eventual effects that publication bias might have in the alcohol-related literature. The first part describes the various types of elasticities and the methods of estimation. This study is estimating the so called true effect elasticity in order to show how elastic the demand for alcoholic beverages is. As there are many ways how to estimate the elasticities it is also analysed if different approaches to the estimation lead to different results. The use of modern meta- analytical methods leads to significantly different results from the ones of previous meta-analyses. The estimated true effects yields new evidence that the demand for alcoholic beverages might be perfectly inelastic. Evidence of publication bias is quite strong and it appears that the economics research cycle hypothesis is also valid.
|
|
|
Applications of dendrochronology in hydrology and fluvial geomorphology
Šálek, Oldřich ; Treml, Václav (advisor) ; Svoboda, Pavel (referee)
Hydrological phenomena are natural processes that shape the landscape around us in the long-term and in some cases threaten our property or health. Dendrochronology is one of the methods of research of these phenomena and reconstruction of past hydrological events, that can be then used to predict and plan security measures in the future. The possibility of using a variety of dendrochronological methods in applied research, we can see in the meta-analysis of scientific studies available in electronic and printed form. The main finding of meta-analysis is a significant geographical disproportion in dendrohydrological survey. It also introduces a wide range of indicators, which are observed in various hydrological phenomena and also demonstrates application of dendrohydrological methods on specific studies.
|
|
|
Context of agenda-setting in the context of Czech media studies
Nečas, Vlastimil ; Jirák, Jan (advisor) ; Just, Petr (referee) ; Šubrt, Jiří (referee)
This dissertation thesis follows from a wide stream of considerations of the relationship between the mass media, public and politics; in particular detail, it deals with a specific concept which attempts to grasp, model and empirically examine this relationship. The main goals of the thesis can be in short divided into two interrelated areas. The first aim is to introduce the concept of agenda setting to the Czech academic environment, with its theoretical, terminological and research frame for an analysis of relationships between the mass media content, dynamics of public opinion, and the political sphere. The second aim is to analyze how agenda setting processes are theoretically grounded and studied in the Czech social studies. The theoretical part of the thesis is structured according to two perspectives: diachronic and synchronic. In the diachronic perspective, I try to grasp the social context and historical origins of agenda-setting as a concept, its development, main trends, and developmental lines. This way, I move forward to the synchronic perspective and describe academic grounding of agenda-setting; I give a detailed analysis of the present level of the agenda-setting research and the main research areas through available classifications. The second fundamental area of the dissertation consists...
|
|
|
Dendrochronological dating of catastrophic slope movements
Tumajer, Jan ; Treml, Václav (advisor) ; Burda, Jan (referee)
Mass-movements are one example of natural processes that can pose a serious risk for human beings and their possessions. Dendrochronology, a method capable of their reconstruction, can provide parameters of former events, which can be used for planning protective measures. The possibilities for the application of dendrochronological methods have been tested by means of meta-analysis of electronic and printed scientific articles and a case study focused on former avalanche activity in Schustler's avalanche path (Labský důl, Krkonoše Mts.). The main conclusion of the first one is the clear spatial disproportion of the recent dendrogeomorphological research activities - e.g. the dating of avalanches is typical for mountains of Montana (USA); the Alpine region (mainly Switzerland), on the other hand, absolutely dominates in the research of debris-flows. In the case study, the analysis of material with well-chosen indicators led to high accuracy results comparable with the results of scientific articles focused on avalanches, and made the identification of 14 years (in the period 1953-2007) with potential avalanche acitvity possible. Although methods of dendrogeomorphology are usually neglected in the research of avalanches in the Czech republic, their great potential for future applications is shown....
|
|
|
Intracranial Aneurysms - Treatment Options and Natural Course. Safety and Efficacy of Treatment Strategies for Posterior Inferior Cerebellar Artery Aneurysms.
Petr, Ondřej ; Beneš, Vladimír (advisor) ; Haninec, Pavel (referee) ; Přibáň, Vladimír (referee)
BACKGROUND: Posterior inferior cerebellar artery (PICA) aneurysms are an uncommon, heterogeneous group of aneurysms with poorer neurological outcomes compared to other intracranial aneurysms. At first, as part A, we conducted a systematic review of the literature to evaluate the safety and efficacy of treatment strategies for PICA-aneurysms. Subsequently, as part B, we performed a multicenter retrospective study to analyze the outcome in a large series of patients treated with contemporary microsurgical and endovascular techniques. METHODS: For the meta-analysis, a systematic search of Medline, EMBASE, Scopus and Web of Science was done for studies published through November 2015. We included studies that described treatment of PICA-aneurysms with ≥10 patients. Random-effects meta-analysis was used to pool the following outcomes: complete occlusion, technical success, periprocedural morbidity/mortality, stroke rates, aneurysm recurrence/rebleed, CN-palsies rates, and long-term neurological morbidity/mortality. As the second part, aiming to report the current trends and results in treatment strategies for PICA-aneurysms, records of 94 patients treated for PICA-aneurysms between 2000 and 2015 at 3 large referral neurovascular centers were retrospectively reviewed. RESULTS: In the meta-analysis, we...
|
|
|
Does butterfly mating behaviour change with phenological condition of populations?
VLAŠÁNEK, Petr
The optimization theory assumes that males of insects with separate adult generations should preferentially invest into the mating if there are the most fresh females; in other times they should save energy and focus on maintenance activities. Based on this assumption, butterfly behaviour should change with season, population density (mainly the sex ratio) and day time. To explore these assumptions, we used mark recapture data obtained from several mark-recapture studies, which contained records of behaviour of each handled individual. In total, we analysed data on 14 species, 24 ``butterfly-seasons{\crqq}, 21 737 individuals (14 228 males, 7 509 females). We subjected the behavioural data to ordination analyses controlled for weather effects. For daily patterns, morning and afternoon activities comprise mainly of maintenance activities, while mating seems to occur in middays. Regarding seasonal patterns, males of most of the species switched from mating behaviour to maintenance behaviour. No prevailing trend applied to females, in which we found both transitions from mating behaviour to maintenance activities and opposite patterns. Density predictors (sex ration, daily population size) revealed changes in mating behaviour of one sex with changing the abundance of the other sex. In conclusion, exploring mark-recapture data for behavioural patterns proved to be fruitful, but cannot fully replace studying behaviour via more traditional ethological methods.
|
guest ::
