Role of the trigonal warping on the minimal conductivity of bilayer graphene

Using a reformulated Kubo formula we calculate the zero-energy minimal conductivity of bilayer graphene taking into account the small but finite trigonal warping. We find that the conductivity is independent of the strength of the trigonal warping and it is three times as large as that without trigonal warping, and six times larger than that in single layer graphene. Although the trigonal warping of the dispersion relation around the valleys in the Brillouin zone is effective only for low energy excitations, our result shows that its role cannot be neglected in the zero-energy minimal conductivity.Comment: 4 pages, 1 figur

Therapy-Induced Antibodies Against the Antiviral and Antiproliferative Effects of Interferons in Patients with Chronic Hepatitis C Virus Infection

Sera from 86 patients with chronic hepatitis C virus (HCV) infection treated with recombinant interferons-α (rIFN-α) were screened for IFN-binding and antiviral effect-neutralizing antibodies. Out of the 61 patients treated with rIFN-α2b, 46% had binding and 28% had neutralizing antibodies. 44% of the 25 patients treated with rIFN-α2a developed binding antibodies and 24% had neutralizing antibodies. Contradictory data were observed concerning the appearance of anti-IFN antibodies and the outcome of IFN therapy. A significantly higher number of the patients with a sustained response to rIFN-α2b therapy formed antibodies than the number among the non-responder patients. At the same time, in the patients treated with rIFN-a2a, opposite data were found. The activity of the antibodies in some sera was studied against the antiproliferative effect of IFNs on Daudi cells by measuring the [3H]thymidine incorporation. The binding antibodies without neutralization of the antiviral effect of the IFNs inhibited the antiproliferative activity of the rIFNs, similarly to antibodies having both IFN-binding and antiviral effect-neutralizing capacities. At the same time, the antiproliferative effect of the natural IFN was less affected. It is suggested that the antiproliferative assay is more sensitive than the antiviral method for demonstration of the presence of antibodies exerting an inhibitory effect on the biological activities of IFN

Tectonically controlled Quaternary intracontinental fluvial sequence development in the Nyírség–Pannonian Basin, Hungary

The Quaternary fluvial succession of the Nyírség (NE Hungary), a proximal sub-basin of 4000 km2 in the intracontinental Pannonian Basin, was studied based on log facies analysis. Regional mapping of sequences was established by analysis of fully cored boreholes and high scale local correlations in densely drilled areas. The age of the sequences was determined by correlating the magnetic susceptibility (MS) record of the fully cored boreholes with that of the reference Hungarian boreholes dated paleomagnetically (Dévaványa-1 and Vésztő-1 in Cooke et al., 1979). To give the Hungarian data global perspective they were correlated to the MS curve of the Chinese Loess (Ding et al., 2005) that are in turn correlated with the Marine Isotope Record (Lisiecki and Raymo, 2005 and Gibbard and Cohen, 2008). The ages of the mapped sequence boundaries are 2.62, 2.26, 2.12, 1.22, 1.04, 0.58 and 0.34 Ma respectively and can be related to the transitions from cool to warm conditions. Regional unconformities at 2.26–2.12, 1.22 and 0.58 Ma also coincide with activity maxima of the radiometrically dated Quaternary volcanism. This high frequency of climatically controlled erosive sequence boundaries in the structurally active periods indicates that the sedimentary record of climatic erosion is better expressed in times when structural changes generate instability in the drainage network. The occurrence of packages of regional unconformities in relation to volcanic activity enables the geochronological dating of episodes in the Quaternary compression of the Carpathian–Pannonian region. The role of tectonic control on the climatically induced changes in the drainage network has been explained by a structural development model based on seismic, gravity and magnetic data. The changes in the local paleohydrology were triggered by a compression related elevation of the basement and the associated occurrence of a local transtension-related subsidence

Roma Undergraduates’ Personal Network in the Process of College Transition. A Social Capital Approach

Roma university students’ personal networks become unstable in the process of college transition. We describe the personal networks of these students using the model set up by Brandes et al. (in: Proceedings of the IEEE pacific visualization symposium (Pacific Vis’08), IEEE Computer Society Press, 2008) and analyse the identified groups utilizing the social capital approach. We mapped seventy-six students’ networks applying contact diary. Origin, host and fellow groups significantly differ in their composition; they provide different (‘bonding’ or ‘bridging’) type of resources, and their availability to the Roma students is also different. We found significant differences between the students in their tendency to rely on certain groups in the process of academic adjustment