Seven species of the genus Trichodina Ehrenberg, 1838 were identified during a sampling programme of twenty freshwater fish species from approximately sixty sites in Scotland, England and Wales. Species found include: Trichodina acuta Lom, 1961 from Cyprinus carpio L., Carassius auralus L., Oncorhynchus mykiss (Walbaum), Salmo trutta L. and Phoxinus phoxinus L.; Trichodina domerguei Wallengren, 1897 from Gasterosteus aculeatuir L.; Trichodina tenuidens Faurc-Fremiet, 1944 from Gasterosteus aculeatus; Trichodina pediculus Ehrenberg, 1838 from Gasterosteus aculeatus; Trichodina modesta Lom, 1970 from Abramis brama L.; Trichodina nigra Lom, 1960 from Cyprinus carpio, Salmo trutta and Oncorhynchus mykiss', and Trichodina intermedia Lom, 1960 from Phoxinus phoxinus. Morphological variation within and between host populations and host specificity of the Trichodina species recovered are described.
Edge-colourings of graphs have been studied for decades. We study edge-colourings with respect to hereditary graph properties. For a graph G, a hereditary graph property P and l\geqslant 1 we define X{'_{P,l}} to be the minimum number of colours needed to properly colour the edges of G, such that any subgraph of G induced by edges coloured by (at most) l colours is in P. We present a necessary and sufficient condition for the existence of X{'_{P,l}} . We focus on edge-colourings of graphs with respect to the hereditary properties Ok and Sk, where Ok contains all graphs whose components have order at most k+1, and Sk contains all graphs of maximum degree at most k. We determine the value of X{'_{{S_k},l}}(G) for any graph G,k \geqslant 1, l\geqslant 1 and we present a number of results on X{'_{{O_k},l}}(G) ., Samantha Dorfling, Tomáš Vetrík., and Obsahuje seznam literatury
In this paper, we investigate a measure of similarity of graphs similar to the Ramsey number. We present values and bounds for g(n, l), the biggest number k guaranteeing that there exist l graphs on n vertices, each two having edit distance at least k. By edit distance of two graphs G, F we mean the number of edges needed to be added to or deleted from graph G to obtain graph F. This new extremal number g(n, l) is closely linked to the edit distance of graphs. Using probabilistic methods we show that g(n, l) is close to \frac{1} {2}\left( {\begin{array}{*{20}c} n // 2 // \end{array} } \right) for small values of l > 2. We also present some exact values for small n and lower bounds for very large l close to the number of non-isomorphic graphs of n vertices., Tomasz Dzido, Krzysztof Krzywdziński., and Obsahuje seznam literatury
The article stands as the fourth part of a series about the question answering process during standardized surveys and elaborates the phase of editing the response. Major moments and processes are explained that affect the shape of final answer at this stage and the narrow relationship of these facts to the nature and quality of survey data is pointed out. Step by step those phenomenons like rounding of numerical answers, the effect of answering scales in terms of its range, frequency, polarity or response order are elaborated and facts like response styles, range-frequency effect or positivity bias are mentioned. In the end, the problem of social desirability and its influence onto final answer is addressed, as well as some opportunities of elimination. Described aspects are related mainly to the distinction between factual and attitudinal questions, nonetheless in the course of presentation there are mentioned also particularities of some other question formats., Jak bylo v předchozích částech seriálu několikrát zmíněno, dosažení rozhodnutí ještě není definitivní tečkou za procesem zodpovídání výzkumného dotazu. V poslední fázi kognitivních procesů musí respondenti takto dosaženou odpověď většinou ještě nějakým způsobem upravit. Například je třeba výsledek hledání v paměti a rozhodování přizpůsobit některé z možností, kterou nabízí dotazník, nebo se respondent rozhodne svou výpověď modifikovat k sociálně přijatelnější podobě. Také v této fázi tedy dochází k přímému vlivu kognitivních aspektů na podobu výsledné odpovědi a také zde je tedy vhodné zkoumat, které procesy a faktory mohou odpověď ovlivnit a jaké dopady to může mít na povahu a kvalitu dat získaných v rámci dotazníkového šetření., Jiří Vinopal., and Seznam literatury