There is a great uncertainty about the effect of land use change on grassland ecosystem in the Tibetan Plateau. Net ecosystem carbon exchange (NEE) was measured for native alpine meadow with winter grazing (NAM), abandoned cropland/pasture (APL), perennial Elymus nutans (PEN), and annual oat pasture (AO) on the Tibetan plateau, during the growing seasons in 2009 and 2010 using a transparent chamber technique (Licor-6400). AO significantly decreased annual average NEE by 21.6, 23.7, and 15.7% compared to PEN, NAM, and APL during the growing season in 2010. Compared to PEN, NAM, and APL, AO significantly decreased average ecosystem respiration (Re) by 21.1, 52.3, and 39.3%, respectively, during the growing season in 2009. Soil moisture and total aboveground and belowground biomass together explained 39.6% of NEE variation and 71% in gross primary productivity variation. Soil moisture and belowground biomass explained about 83.1% of the Re variation. Our results indicated that it is possible to convert APL to PEN in the region because it could result in a higher NEE together with higher forage production compared to AO., C.-Y. Luo, X.-X. Zhu, S.-P. Wang, S.-J. Cui, Z.-H. Zhang, X.-Y. Bao, L. Zhao, Y. Li, X.-Q. Zhao., and Obsahuje seznam literatury
A mixture of ryegrass (Lolium italicum A. Braun) and clover (Trifolium alexandrinum L.) was sown in Eboli (Salerno, Southern Italy) in September 2007. Crop growth, leaf and canopy gas exchange and ecophysiological traits were monitored throughout the growth cycle. The gross primary production (GPP) was not affected by air temperature (T air); on the contrary the ecosystem respiration (R eco) decreased as T air decreased while net ecosystem CO2 exchange (NEE) increased. When was normalized with leaf area index (LAI), GPP decreased with T air, a likely response to cold that down-regulated canopy photosynthesis in order to optimize the light use at low winter temperatures. Net photosynthetic rates (PN), the effective quantum yield of PSII (ΦPSII) and photosynthetic pigment content were higher in clover than ryegrass, in relation to the higher leaf N content. The lower ΦPSII in ryegrass was linked to lower photochemical quenching coefficient (qP) values, due to a reduced number of reaction centres, in agreement with the lowest Chl a content. This behaviour can be considered as an adaptive strategy to cold to avoid photooxidative damage at low temperature rather than an impairment of PSII complexes., L. Vitale ... [et al.]., and V klíčových slovech chybně uvedené jméno Lolium italicum A. Barum
Enzymes that hydrolyze extracellular ATP, i.e. ecto-ATPase and ecto-ATP diphosphohydrolase (ATPDase), can be differentiated by ability of the latter to hydrolyze ADP and by slightly different kinetic properties of the two enzymes. Synaptic plasma membrane fractions isolated from rat hippocampus and caudate nucleus exhibit ADP-hydrolyzing activity, as revealed by the enzyme assay, and the presence of ecto-ATPase protein, as revealed by immunological identification on Western blot. These findings indicate that both enzymes are co-expressed in the synaptic membrane compartment of hippocampal and caudate nucleus neurons. Kinetic analysis was performed to determine the relative contribution of each enzyme to the total ATP-hydrolyzing activity, while an inhibition study was carried out in order to exclude the interference of other nonspecific ATPase and phosphatase activities. Based on the kinetic properties, sensitivity to inhibitors and VATP/VADP ratio of about 2, we concluded that a substantial portion of ATP-hydrolyzing activity in both synaptic membrane preparations can be ascribed to the catalytic action of ATPDase. On the other hand, the highest catalytic efficacy when ATP is the substrate and the greater abundance of ecto-ATPase protein in caudate nucleus preparation suggest that the relative contribution of ecto-ATPase to the total ATP-hydrolyzing activity in the caudate nucleus is higher than in the hippocampus., N. Nedeljkovic, A. Banjac, A. Horvat, M. Stojiljkovic, G. Nikezic., and Obsahuje bibliografii
The signed edge domination number and the signed total edge domination number of a graph are considered; they are variants of the domination number and the total domination number. Some upper bounds for them are found in the case of the $n$-dimensional cube $Q_n$.
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
Given two disjoint copies of a graph $G$, denoted $G^1$ and $G^2$, and a permutation $\pi $ of $V(G)$, the graph $\pi G$ is constructed by joining $u \in V(G^1)$ to $\pi (u) \in V(G^2)$ for all $u \in V(G^1)$. $G$ is said to be a universal fixer if the domination number of $\pi G$ is equal to the domination number of $G$ for all $\pi $ of $V(G)$. In 1999 it was conjectured that the only universal fixers are the edgeless graphs. Since then, a few partial results have been shown. In this paper, we prove the conjecture completely.
Od počátku roku 2012 je na FF UK v Praze v rámci pětiletého projektu GA ČR připravována kritická čtenářská edice korespondence Karla Havlíčka. Projekt je koncipován jako interdisciplinární (historický a jazykovědný) a navazuje na edici a výzkum korespondence Boženy Němcové. Půjde o první úplnou edici Havlíčkovy korespondence (odeslané i přijaté). Všechny dopisy jsou digitálně fotografovány, transliterovány (transliterační zásady jsou zde otištěny jako příloha) a bude z nich vytvořen počítačový korpus, který mj. napomůže i přesnosti edičního zpracování., Since January 2012, a critical popular edition of Karel Havlíček’s correspondence is being prepared for publication at the Faculty of Arts, Charles University in Prague, with support of Czech Science Foundation. This five-year project is designed as interdisciplinary (historical as well as linguistic) and it builds on the publication and research of the correspondence of Božena Němcová. It is going to be the first complete edition of the letters both written by and addressed to Havlíček. All letters are being shot digitally and transliterated (the manual for transliteration is published here as an appendix); then, a computer language corpus of Karel Havlíček’s correspondence will be built, which-among others-will help in achieving accuracy of the editorial processing. (Translated by Robert Adam.), and Překlad resumé: Robert Adam
Příspěvek pojednává o připravované edici Pražská škola v korespondenci, zahrnující dopisy adresované představitelům Pražského lingvistického kroužku B. Havránkovi, R. Jakobsonovi, J. Mukařovskému, V. Mathesiovi a B. Trnkovi z let 1923-1989. Dokumentární i objevný soubor představuje dopisy jednak od členů Ženevské a Kodaňské školy či plejády dalších evropských strukturalistů, jednak od českých vědců a osobností první i druhé strukturalistické generace působících v Praze., This paper deals with the forthcoming Prague School in Correspondence series, including letters addressed to representatives of the Prague Linguistic Circle, e.g. Bohuslav Havránek, Roman Jakobson, Jan Mukařovský, Vilém Mathesius and Bohumil Trnka from 1923 to 1989. This innovative documentary collection presents letters from members of the Geneva and Copenhagen schools and a pleiad of other European structuralists, as well as from Czech scholars and figures from the first and second structuralist generations working in Prague. (Translated by Melvyn Clarke.), and Překlad resumé: Melvyn Clarke