Embedding graphs having Ore-degree at most five

Let $H$ and $G$ be graphs on $n$ vertices, where $n$ is sufficiently large. We prove that if $H$ has Ore-degree at most 5 and $G$ has minimum degree at least $2n/3$ then $H\subset G.$Comment: accepted for publication at SIAM J. Disc. Mat

The role of currency swaps in the domestic banking system and the functioning the swap market during the crisis

The basic purpose of this study is to didactically demonstrate the factors shaping the currency swap stock of domestic banks prior to the crisis and to provide a descriptive analysis of how the structure and the functioning of the market changed during the crisis. The main conclusions of the study are as follows. In addition to the wide ranging applicability of the transaction, the rise in the currency swap stock of domestic credit institutions is also attributable to macroeconomic factors. The bulk of the exchange rate risk resulting from the high external borrowing requirement and rising external debt was carried by the domestic private sector, while the foreign sector shared a decreasing portion of the risk. The rapid increase in the swap stock was also due to the fact that the synthetic production of foreign currency funds with currency swaps was often more successful than the direct inflow of foreign currency funds. On the basis of the decomposition of the domestic banking system’s on-balance sheet foreign currency position, we can state that it increased mainly as a result of items that also increased the balance sheet total. Following the outbreak of the global financial crisis in the autumn of 2008, the conditions for ensuring foreign currency liquidity deteriorated significantly, which had a substantial effect on implied forint yields, and the turnover and structure of the swap market. While the total average turnover of the domestic FX swap market did not drop radically when the crisis was spreading, market liquidity did decline significantly for a few days and access to foreign currency liquidity became limited. The active role assumed by parent banks and shortening maturities contributed to moderating the decline in turnover. Anecdotal information relating to the tightening of counterparty limits vis-a-vis domestic banks is supported by the decline in the number of non-resident counterparties. The crisis also contributed to changes in the structure of the swap stock. The average remaining maturity of the gross stock began to decline directly after the Lehman bankruptcy, at the time of global dollar liquidity problems, followed by a rise starting from early 2009, principally owing to transactions concluded with parent banks. Domestic subsidiary banks managed to increase maturity primarily through cross-currency swap transactions concluded with intra-group counterparties, but non-group counterparties also concluded transactions with longer maturity with domestic banks.FX swap, currency swap, foreign currency based loan, crisis, counterparty limit, margin call, liquidity requirement

An Autocatalytic Step in the Reaction Cycle of Hydrogenase from Thiocapsa roseopersicina Can Explain the Special Characteristics of the Enzyme Reaction

AbstractA moving front has been observed as a special pattern during the hydrogenase-catalyzed reaction of hydrogen uptake with benzyl viologen as electron acceptor in a thin-layer reaction chamber. Such fronts start spontaneously and at random times at different points of the reaction chamber; blue spheres are seen expanding at constant speed and amplitude. The number of observable starting points depends on the hydrogenase concentration. Fronts can be initiated by injecting either a small amount of completed reaction mixture or activated hydrogenase, but not by injecting a low concentration of reduced benzyl viologen. These characteristics are consistent with an autocatalytic reaction step in the enzyme reaction. The special characteristics of the hydrogen-uptake reaction in the bulk reaction (a long lag phase, and the enzyme concentration dependence of the lag phase) support the autocatalytic nature. We conclude that there is at least one autocatalytic reaction step in the hydrogenase-catalyzed reaction. The two possible autocatalytic schemes for hydrogenase are prion-type autocatalysis, in which two enzyme forms interact, and product-activation autocatalysis, where a reduced electron acceptor and an inactive enzyme form interact. The experimental results strongly support the occurrence of prion-type autocatalysis

Theory of inter-Landau-level magnetoexcitons in bilayer graphene

If bilayer graphene is placed in a strong perpendicular magnetic field, several quantum Hall plateaux are observed at low enough temperatures. Of these, the sigma(xy) = 4ne(2)/h sequence (n not equal 0) is explained by standard Landau quantization, while the other integer plateaux arise due to interactions. The low-energy excitations in both cases are magnetoexcitons, whose dispersion relation depends on single-and many-body effects in a complicated manner. Analyzing the magnetoexciton modes in bilayer graphene, we find that the mixing of different Landau level transitions not only renormalizes them, but essentially changes their spectra and orbital character at finite wavelength. These predictions can be probed in inelastic light scattering experiments. DOI: 10.1103/PhysRevB.87.08543

Determination of master curves for asphalt mixtures by means of IT-CY tests

The concept of ecologically conscious and energy saving roads must be expanded to the performance of the asphalt mixtures as well as to the test related to it. This paper investigates the tests focusing on a better description of the behaviour of asphalts as well as on a deeper revelation of the impact of different compositions. Based on the international experiences the recording of the asphalt´s complex module over the entire temperature range by the determination and evaluation of the mater-curves appeared as a possible solution for more precise description of the asphalt behaviour

The epidemiology of mathematical performance, anxiety, and psychosomatic symptoms

This work was supported by the Research Programme for Public Education Development of the Hungarian Academy of Sciences

Disinfection action of some essential oils on stainless steel

Bacteria can attach to different surfaces and form biofilm. Biofilms can cause a big problem in food industry by contamination of food items and reduction of the effectiveness of machines. In the biofilm bacteria are less exposed to the different disinfectants, than the free living cells. Essential oils (EO) with known antimicrobial effect can also inhibit biofilm formation. In our experiments minimal inhibitory concentrations (MIC) and minimal bactericide concentrations (MBC) of the investigated EOs: cinnamon, juniper and lemon were determined by macro-dilution method on Pseudomonas putida and E.coli. Cinnamon showed the best antibacterial effect with MBC values of 2mg/ml forE. coli and 4mg/ml forP.putida. Thebactericidaleffect of EOsdependedontheactingtime. We established 80 minutes forP. putida and 120 (cinnamon EO) and 240 (juniper EO) min forE. coli. The disinfection potential of the EOs were studied on P. putida and E. coli 1 and 7 days old biofilms formed on industrial stainless steel surfaces. Each of the EO was effective. The number of P. putida cells was reduced up to 99% and we had similar result by 1 day old E. coli biofilm. The cell number of 7 days old E. coli biofilm was reduced by 62.5% with cinnamon EO and juniper EO reduced it by 87%