scholarly journals Cyclic abundance fluctuations in a completely isolated population of Euphydryas maturna

2021 ◽  
Vol 44 ◽  
pp. 213-222
Author(s):  
Václav John ◽  
Alois Pavlíčko ◽  
Vladimír Vrabec ◽  
Veronika Rybová ◽  
Miloš Andres ◽  
...  
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Natural Enemies ◽  
Single Site ◽  
Ex Situ ◽  
Isolated Population ◽  
Peak Period ◽  
Local Populations ◽  
Harmonic Means ◽  
Abundance Fluctuations

A highly isolated and the last autochthonous Czech Republic population of the endangered Euphydryas maturna (Lepidoptera: Nymphalidae) is monitored since 2001 by larval nests counts. The 20 years` time series displays remarkable abundance fluctuations with peak-to-peak period 11 years, peak numbers >150 and bust numbers <15 larval nests (arithmetic and harmonic means: 92.6 and 36.3). Establishment of more favourable management of the site probably heightened and prolonged the boom phase but did not alter the overall pattern. We attribute the cycling to pressures of natural enemies. Climatically unfavourable years appear deepening the bust phase. Species displaying such fluctuations cannot be conserved within a single site, which is being addressed by ex-situ breeding of the Czech stock and recent reestablishment of two additional populations, with the aim to achieve asynchronous dynamics of the local populations and eventually stabilise the regional metapopulation.

scholarly journals Measuring creative capacity of Visegrad Four countries’ economies

Region Direct ◽  
2014 ◽  
Vol 7 (1) ◽  
pp. 77-104
Author(s):  
Martin Alexy ◽  
Marek Káčer
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Open Source ◽  
Cross Section ◽  
Empirical Results ◽  
The Cross ◽  
Creative Capacity

Abstract In this paper we study creative capacity of economies of Visegrad Four countries in the period 2000-2011. Creativity index is constructed based on the 3Ts concept of talent, technology and tolerance being the key components of the creativity. Creativity index is measured and calculated with both the cross-section and the time series dimensions. The paper provides index as an open source with the description of variables and their respective weights. Comparison of the creative capacity of economies is based on the empirical results of the Creativity index and its components. Czech Republic is the first and Hungary is the second in the ranking continuously during the examined period. Talent and technology areas are the main reasons for differences between the two leading countries and the rest.

scholarly journals Contribution to knowledge of Hylesinus fraxini (Panzer, 1779) (Coleoptera: Scolytidae) natural enemies from Northern Moravia (Czech Republic)

2008 ◽  
Vol 53 (Special Issue) ◽  
pp. 53-56
Author(s):  
O. Nakládal ◽  
M. Turčáni
Keyword(s):  
Czech Republic ◽  
Natural Enemies ◽  
Total Mortality ◽  
Predation Rate ◽  
Total Rate ◽  
Mortality Factors ◽  
Thanasimus Formicarius ◽  
Insect Predator

Predation by natural enemies was studied as mortality factors of <I>Hylesinus fraxini</I> in 2006–2007. Predation by birds was not recorded and predation rate by insect reached 0.1%. Only one insect predator was reared – <I>Thanasimus formicarius</I> (Linnaeus, 1758). The total rate of parasitism was 54.0%. At least 8 species of parasitoids from the order Hymenoptera were recorded. The most abundant parasitoid was <I>Eurytoma morio Boheman</I>, 1836 (44.1% from the total number of all reared parasitoids; 23.8% of the total mortality), subsequently <I>Eurytoma arctica</I> Thomson, 1876 (31.7%; 17.1%), <I>Cheiropachus quadrum</I> (Fabricius, 1787) (12.8%; 6.9%), Braconidae (6.3%; 3.4%), <I>Rhaphitelus maculatus</I> Walker, 1834 (3.9%; 2.1%), <I>Mesopolobus</I> sp. (0.5%; 0.3%), were not identified Pteromalidae (0.5%; 0.3%) and <I>Tetrastichus</I> sp. (0.2%; 0.1%).

scholarly journals Scale-dependent portfolio effects explain growth inflation and volatility reduction in landscape demography

2017 ◽  
Vol 114 (47) ◽  
pp. 12507-12511 ◽  
Author(s):  
Cang Hui ◽  
Gordon A. Fox ◽  
Jessica Gurevitch
Keyword(s):  
Invasive Species ◽  
Time Series ◽  
Regional Scale ◽  
Scaling Up ◽  
Range Shifts ◽  
Attainable Set ◽  
Local Populations ◽  
Accumulation Curve ◽  
Invasive Organisms ◽  
Regional Population

Population demography is central to fundamental ecology and for predicting range shifts, decline of threatened species, and spread of invasive organisms. There is a mismatch between most demographic work, carried out on few populations and at local scales, and the need to predict dynamics at landscape and regional scales. Inspired by concepts from landscape ecology and Markowitz’s portfolio theory, we develop a landscape portfolio platform to quantify and predict the behavior of multiple populations, scaling up the expectation and variance of the dynamics of an ensemble of populations. We illustrate this framework using a 35-y time series on gypsy moth populations. We demonstrate the demography accumulation curve in which the collective growth of the ensemble depends on the number of local populations included, highlighting a minimum but adequate number of populations for both regional-scale persistence and cross-scale inference. The attainable set of landscape portfolios further suggests tools for regional population management for both threatened and invasive species.

Adversary Voting in the Czech Chamber of Deputies (1993–2013)

2017 ◽  
Vol 13 (1) ◽  
pp. 99-122
Author(s):  
Petr Dvořák
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Success Rate ◽  
Major Change ◽  
The Czech Republic ◽  
Discrimination Capacity ◽  
High Concentrations ◽  
The Government ◽  
Chamber Of Deputies

AbstractThe paper explores the legislative unity of government and opposition blocs in the Czech Chamber of Deputies over a period of 20 years. As voting unity is usually rather low in the Czech Republic, temporarily high concentrations of votes by these blocs are linked to higher rates of conflict between the government and opposition. I use the Rice and UNITY indices to compare average unity scores of individual cabinets and also explorative time series of unity vectors in order to analyse bloc concentration, success rate, and increased conflict. The outcomes are relevant both as comprising a case study and methodological observations: (1) Broad differences in the logic of interaction are confirmed (e.g. caretaker cabinets show less conflict than standard cabinets). Although no universal trend (e.g. no transition from consensual to conflictual practice) is found, the Czech opposition became more concentrated and resorted to serial blocking tactics in the second decade; thus, a major change of behavior occurred after all. (2) The Rice and UNITY indices correlate considerably; UNITY’s discrimination capacity is not distorted significantly despite the nature of equilibria in the Chamber. Moreover; the UNITY index is able to easily distinguish contested votes not detectable by the Rice index alone.

scholarly journals Export performance and competitiveness in wood products in the Czech Republic and Austria

2019 ◽  
Vol 70 (5) ◽  
pp. 743-764
Author(s):  
Nahanga Verter ◽  
Libor Grega
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Trade Balance ◽  
Export Performance ◽  
Single Market ◽  
Wood Products ◽  
Export Diversification ◽  
The Czech Republic ◽  
Balance Index ◽  
The Eu

This article assesses the development of wood exports in the Czech Republic (Czechia) and Austria in recent years. Some approaches, such as revealed comparative advantage (RCA), relative trade balance index (RTB), and diversification ratios are used to assess the export performance and competitiveness indicators in these countries. The RCA result reveals that both Czechia and Austria have been competitive in the global wood markets, just as the countries have witnessed positive in RTB within the period under study. Market diversification results indicate that both countries concentrated in few markets (mainly within the EU single market) for exports of wood products. Also, the competitiveness based on the product structure shows that both countries, notably Austria wood product groups have been diversified and mostly processed before exports. In summary, both countries have performed impressively within the period under study even though the time series for the research was short. Nevertheless, there is a need for market export diversification beyond the EU’s single market.

scholarly journals Partial equilibrium model – Case study of the poultry market

2011 ◽  
Vol 59 (7) ◽  
pp. 431-438
Author(s):  
Lenka Šobrová ◽  
M. Malý ◽  
Z. Malá
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Panel Data ◽  
Equilibrium Model ◽  
Poultry Meat ◽  
Partial Equilibrium ◽  
The Czech Republic ◽  
Estimated Parameters ◽  
Partial Equilibrium Model ◽  
Main Factors

This paper deals with identifying the main determinants in the poultry agri-food chain in the Czech Republic and examines their relationships. The partial equilibrium model, defined as a seven-equation model in power form, is employed for this purpose. The analysis is based on both time-series and panel data of the main factors in the poultry market. The time-series as well as panel data contain annual data of selected variables for the period from 1995 to 2009. The analysis is focused on supply and demand of poultry meat, specifically on production, consumption and foreign trade in poultry meat in the Czech Republic. Firstly, the main factors influencing the poultry market are determined, then, an appropriate model is employed. The parameters of the model are estimated using the ordinary least squares method in statistical and econometric software. Estimated parameters confirm assumed relationships among the selected variables. Moreover, the long-term tendencies of the selected indicators are proven. Among other, the analysis proves an inertial consumption, the price level as the main factor influencing the consumption and one-way or mutual relationship among the selected variables. The statistical features of the model are satisfied as well – the estimated parameters are statistically significant, the model does not contain, neither the problem of autocorrelation of residuals nor the problem of heteroskedasticity.

scholarly journals The relationship between M3 and consumer price index in the Czech Republic

2018 ◽  
Vol 4 (10) ◽  
pp. 226-236
Author(s):  
Libena Cernohorska
Keyword(s):  
Time Series ◽  
Czech Republic ◽  
Price Index ◽  
Statistical Data ◽  
Consumer Price Index ◽  
Monetary Aggregate ◽  
The Czech Republic ◽  
Significance Level ◽  
The Relationship ◽  
Cointegration Relationship

This paper aimed at analysing the influence of monetary aggregate M3 on consumer price index (CPI) in the Czech Republic. Cointegrating this selected indicator M3 is demonstrated in relation to the development of CPI using the Engle – Granger cointegration test. These tests are applied to selected statistical data from the years 2003 to 2016. After using the Akaike criteria for all-time series, we analysed a unit root using the Dickey–Fuller test. If the time series are non-stacionary, testing is then continued with the Engle–Granger test to detect cointegration relations. Based on these tests, it is found that at a significance level of 0.05, a cointegration relationship between M3 and CPI in the Czech Republic does not exist. Conclusions resulting from the verification of the hypotheses are supported with graphical visualisation of data from which it is apparent that these hypotheses can be rejected. Keywords: M3; Czech Republic ; CPI ; Akaike criteria

scholarly journals Innovations’ Survival

2016 ◽  
Vol 64 (4) ◽  
pp. 1393-1399
Author(s):  
Jakub Tabas ◽  
Michaela Beranová
Keyword(s):  
Time Series ◽  
Survival Analysis ◽  
Czech Republic ◽  
Financial Performance ◽  
Economic Effect ◽  
The Czech Republic ◽  
Going Concern ◽  
Deviation Analysis ◽  
Three Samples ◽  
Technical Innovations

Innovations currently represent a tool of maintaining the going concern of a business entity and its competitiveness. However, effects of innovations are not infinite and if an innovation should constantly preserve a life of business entity, it has to be a continual chain of innovations, i.e. continual process. Effective live of a single innovation is limited while the limitation is derived especially from industry. The paper provides the results of research on innovations effects in the financial performance of small and medium-sized enterprises in the Czech Republic. Objective of this paper is to determine the length and intensity of the effects of technical innovations in company’s financial performance. The economic effect of innovations has been measured at application of company’s gross production power while the Deviation Analysis has been applied for three years’ time series. Subsequently the Survival Analysis has been applied. The analyses are elaborated for three statistical samples of SMEs constructed in accordance to the industry. The results obtained show significant differences in innovations’ survival within these three samples of enterprises then. The results are quite specific for the industries, and are confronted and discussed with the results of authors’ former research on the issue.

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