Introduction of Alien Tree Species and its Influence on Floristical Composition and Vegetation Structure of Acidophilous Oak Forests: The Experimental Plots in the Zielonka Forest

In 1879 Schwappach first established 54 experimental forest plots on habitat of acidophilous oak forest Calamagrostio-Quercetum in the Zielonka Forest near Poznań, on which 20 exotic tree species were cultivated. Until this day 32 of the mentioned forest sites have been preserved and today only 9 species are present there. The aim of the study was to determine actual condition of the experimental plots, a description of their flora and vegetation, as well as a comparison with other test plots situated in the direct neighbourhood. Basing on 63 phytosociological relevés, an influence of exotic species plantings on the structure of vegetation and local biodiversity was assessed. Floristic richness of both experimental plots (88 species), as well as their direct neighbourhood (68) was recognised, along with the geographical-historical groups spectrum and species affiliation to phytosociological classes

Effect of Sintering Temperature on Microstructure, Corrosion Behavior, and Hardness of Nanocrystalline Al-5at.%Ni and Al-5at.%V Alloys

The purpose of this project was to investigate thermal stability of high energy ball milled Al-5at.%Ni and Al-5at.%V alloys. Characterization was done by analyzing grain size and solid solubility. Samples were created using high energy ball milling, cold compaction to 3 GPa, and sintering from 100 °C to 500 °C at 100 °C increments, as well 450 °C and 614 °C. Microstructure, mechanical properties, and corrosion properties were determined using scanning electron microscopy, energy dispersive x-ray spectroscopy, x-ray diffraction, hardness testing, and cyclic potentiodynamic polarization. Vickers hardness of Al-5at.%Ni decreased with increasing temperature. For Al-at.%V, hardness increased with sintering temperature up to 300 °C before decreasing higher sintering temperatures. As sintering temperature increased, solid solubility of both alloying elements decreased, and grain size of both alloys increased. Corrosion testing was not conclusive due to limited repetition, but trended towards lower pitting potentials with lower hardness values and higher sintering temperatures. These findings follow previous research of Al-Cr alloys, and will be useful in future work to identify the optimal sintering temperature to create high strength, corrosion resistant aluminum alloys

From regional to national clouds: TV coverage in the Czech Republic

Media, and particularly TV media, have a great impact on the general public. In recent years, spatial patterns of information and the relevance of intangible geographies have become increasingly important. Gatekeeping plays a critical role in the selection of information that is transformed into media. Therefore, gatekeeping, through national media, also co-forms the generation of mental maps. In this paper, correspondence analysis (a statistical method) combined with cloud lines (a new visual analytics technique) is used to analyze how individual major regional events in one of the post-communist countries, the Czech Republic, penetrate into the media on a national scale. Although national news should minimize distortions about regions, this assumption has not been verified by our research. Impressions presented by the media of selected regions that were markedly influenced by one or several events in those regions demonstrate that gatekeepers, especially news reporters, functioned as a filter by selecting only a few specific, and in many cases, unusual events for dissemination.Web of Science1111art. no. e016552

Visual Effects of Logo on the Attentional Filter and Perception

The purpose of this project is to understand the effects of different logo design elements (i.e. spatial frequency, contrast sensitivity, and colour) to assess their effectiveness at gaining the attention of consumers. The propensity of elemental changes to break through the attentional filter is expected to provide insight into the decisions made about brand logo design to improve the likelihood that a logo can gain attention in a busy market or communication channel

Interspecific gene flow and ecological selection in a pine (Pinus sp.) contact zone

Nucleotide polymorphisms in a set of nuclear genes were studied in a sympatric population of pines Pinus mugo and Pinus sylvestris that includes trees classified as pure species and polycormic (multi-stemmed)individuals of potentially hybrid origin. Patterns of genetic diversity were compared between those groups of samples and to the reference allopatric populations of the species in Europe. Polymorphisms at the gene loci clearly distinguished pure parental species as measured by conventional frequency-based statistics and Bayesian assignment of samples into separate genetic clusters. Most individuals classified based on phenotypic assessments as putative hybrids were genetically very similar to P. mugo showing no existing average net divergence and genetic assignment to the same genetic cluster. On the other hand, individuals of P. sylvestris showed homogenous genetic background to the reference populations of the species from Central and Northern Europe. Ten individuals of admixed genetic composition were found in all three groups of samples; however, the majority of hybrids except one individual were identified across the samples classified as P. mugo and polycormic pines. Those trees that contained a mixture of nuclear gene haplotypes observed in the reference populations of pure species and cpDNA from P. mugo, most likely represent the first generation of hybrids. Analysis of the allelic frequency spectra and compound neutrality tests identified deviations from neutrality at several genes. This contact zone seems suitable for selection of a mapping population both in hybrid and parental species for admixture mapping to effectively search for polymorphisms that may play role in species adaptive variation and speciation

Towards a Better Understanding of the Local Attractor in Particle Swarm Optimization: Speed and Solution Quality

Particle Swarm Optimization (PSO) is a popular nature-inspired meta-heuristic for solving continuous optimization problems. Although this technique is widely used, the understanding of the mechanisms that make swarms so successful is still limited. We present the first substantial experimental investigation of the influence of the local attractor on the quality of exploration and exploitation. We compare in detail classical PSO with the social-only variant where local attractors are ignored. To measure the exploration capabilities, we determine how frequently both variants return results in the neighborhood of the global optimum. We measure the quality of exploitation by considering only function values from runs that reached a search point sufficiently close to the global optimum and then comparing in how many digits such values still deviate from the global minimum value. It turns out that the local attractor significantly improves the exploration, but sometimes reduces the quality of the exploitation. As a compromise, we propose and evaluate a hybrid PSO which switches off its local attractors at a certain point in time. The effects mentioned can also be observed by measuring the potential of the swarm