Industrialized areas represent a special group of urbanized areas, but sufficient attention has not been given to them concerning plant species richness and its importance for biodiversity conservation. These sites are considered the main drivers of biological invasions and biotic homogenization on a global scale, but the question of how and to what degree they contribute to biodiversity has yet to be raised. Data for 62 river ports (16 German, 26 Czech, 7 Hungarian, 4 Slovak, and 9 Austrian) on two important Central European waterways (the Elbe-Vltava and Danube waterways) were gathered for 40 years. In total, 1 240 plant species were found. Of these, 371 were classified as threatened and protected, nearly one third of the total number of species found in all of the studied Elbe, Vltava, and Danube ports. Significant differences in the proportion of threatened species in ports and cities were not found. More threatened species were found in the Danube ports than in the other ports, but their numbers fluctuated depending on the size of the port and the region (country). The results showed that the ports must be regarded as special types of species-rich industrial areas; thus, they should not be considered to be only sources of spreading invasive alien species. When planning port development, uniformity and vegetation management that is too intensive should be avoided. Extensively managed open areas and habitat diversity should be maintained.
Previous research suggests that developments in young people's peer relationships may either compound or alleviate the adverse impacts of other major life changes during adolescence. We explored this proposition with respect to young people's educational attainment upon leaving high school, using longitudinal data from a large cohort of Australian secondary school students (n?=?1612) who have taken part in the Our Lives research study between the ages of 12/13 and 19/20 years. Our analysis focused on the role of peer relationship events such bullying, friendship problems, falling in love, and breaking up with someone. Bullying and romantic involvement were associated with lower odds of receiving a competitive tertiary entrance rank at the end of high school. However, close, resilient friendships – in which status and identity conflicts may be more easily tolerated and resolved – may help to offset the role of these other events. As well as reviewing the consequences of our findings for young people's educational and occupational trajectories in the longer-term, we highlight their implications for future research and policy in this area. 相似文献
We investigate how we can bound a discrete time Markov chain (DTMC) by a stochastic matrix with a low rank decomposition. In the first part of the article, we show the links with previous results for matrices with a decomposition of size 1 or 2. Then we show how the complexity of the analysis for steady-state and transient distributions can be simplified when we take into account the decomposition. Finally, we show how we can obtain a monotone stochastic upper bound with a low rank decomposition. 相似文献
A key concept of the forward search algorithm in confirmatory factor analysis is ordering of the data on the basis of observational residuals. These residuals are computed under the proposed model and measure the discrepancy between the observed and predicted response for each unit of the sample. Regression-type factor scores are used to estimate model predictions. Informative forward plots are created for indexing influential observations and to show the dynamics of the estimates throughout the search. The detailed influence of each observation on the model parameters and fit indices is analyzed and a robust model inference is achieved. Real and simulated data sets with known contamination schemes are used to demonstrate the performance of the forward search algorithm. 相似文献
The decline of fertility in Czechoslovakia on the territory of the Czech Socialist Republic began with a rise in the age at marriage; the decline of marital fertility began only after 1860. On the territory of the Slovak Socialist Republic marital fertility began to decline after 1900 without previous significant changes in the age at marriage. The differences between the demographic behaviour in the two parts of Czechoslovakia have persisted, although they are now gradually disappearing. There are other significant regional differences in the fertility decline caused by the overall process of economic and social development. The end of the demographic transition in the Czech Socialist Republic came during the 1930's and in the Slovak Socialist Republic during the 1960's. 相似文献
We propose a spatial-temporal stochastic model for daily average surface temperature data. First, we build a model for a single spatial location, independently on the spatial information. The model includes trend, seasonality, and mean reversion, together with a seasonally dependent variance of the residuals. The spatial dependency is modelled by a Gaussian random field. Empirical fitting to data collected in 16 measurement stations in Lithuania over more than 40 years shows that our model captures the seasonality in the autocorrelation of the squared residuals, a property of temperature data already observed by other authors. We demonstrate through examples that our spatial-temporal model is applicable for prediction and classification. 相似文献
In this paper we present a new characterization of the Pareto distribution and consider goodness-of-fit tests based on it. We provide an integral and Kolmogorov–Smirnov-type statistics based on U-statistics and we calculate Bahadur efficiency for various alternatives. We find locally optimal alternatives for those tests. For small sample sizes, we compare the power of those tests with some common goodness-of-fit tests. 相似文献
VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - An extensive literature identifies conditions under which markets and states work efficiently and effectively toward their... 相似文献
Globalization is constantly changing the appearance of the modern world. The most intense processes of integration are taking
place in Europe in the framework of the European Union (EU) enlargement. Though the formal process is more or less concluded,
the subtle and informal ones still have a long way to go. Social structures (institutions, organizations, norms, etc.) and
actions depend on the cultural environment in the narrowest sense of the word: human perceptions and values. This poses the
basic question whether the economic-cultural orientations of the new EU member states are compatible with imported social
structures. We have done an empirical research using Hofstede's cultural dimensions and European Values Study database for
26 European countries (23 EU member states, 2 candidate countries, and Northern Ireland as a separate entity). We have also
compared the differences and similarities by applying the Ward method (cluster analysis) on our 10 constructed variables. 相似文献