Communication practices of the Karen in Sheffield: Seeking to navigate their three zones of displacement

This study investigates communication practices of a newly arrived Karen refugee community in the UK who, as well as establishing themselves in a strange country, seek to keep in touch, campaign politically and maintain identity collectively through communication and contact with their global diaspora. We look at the technologies, motivations and inhibiting factors applying to the communication by adult members of this community and construct the idea of three zones of displacement which help to model the particular contexts, challenges and methods of their communication. We find that overall, they are using a wide range of internet-based technologies, with the aim to 'keep-in-touch' (personal contacts) and to 'spread the word' (political communication). This also includes archaic, traditional and hybrid methods to achieve extended communication with contacts in other 'zones'. We also identify the importance of the notion of ‘village’ as metaphor and entity in their conceptualisation of diasporic and local community cohesion. We identify the key inhibitors to their communication as cost, education, literacy and age. Finally, we speculate on the uncertain outcomes of their approach to digital media in achieving their political aims

Lateral asymmetry of voluntary attention orienting

We recently demonstrated that automatic attention favors the right side of space and, in the present study, we investigated whether voluntary attention also favors this side. Six reaction time experiments were conducted. In each experiment, 12 new 18-25-year-old male right-handed individuals were tested. In Experiments 1, 2, 3 (a, b) and 4 (a, b), tasks with increasing attentional demands were used. In Experiments 1, 2, 3a, and 4a, attention was oriented to one or both sides by means of a central spatially informative visual cue. A left or right side visual target appeared 100, 300, or 500 ms later. Attentional effects were observed in the four experiments. In Experiments 2, 3a and 4a, these effects were greater when the cue indicated the right side than when it indicated the left side (respectively: 16 ± 10 and 44 ± 6 ms, P = 0.015, for stimulus onset asynchrony of 500 ms in Experiment 2; 38 ± 10 and 70 ± 7 ms, P = 0.011, for Experiment 3a, and 23 ± 11 and 61 ± 10 ms, P = 0.009, for Experiment 4a). In Experiments 3b and 4b, the central cue pointed to both sides and was said to be non-relevant for task performance. In these experiments right and left reaction times did not differ. The most conservative interpretation of the present findings is that voluntary attention orienting favors the right side of space, particularly when a difficult task has to be performed

Holographic description of Kerr-Bolt-AdS-dS Spacetimes

We show that there exists a holographic 2D CFT description of a Kerr-Bolt-AdS-dS spacetime. We first consider the wave equation of a massless scalar field propagating in extremal Kerr-Bolt-AdS-dS spacetimes and find in the "near region", the wave equation in extremal limit could be written in terms of the $SL(2,R)$ quadratic Casimir. This suggests that there exist dual CFT descriptions of these black holes. In the probe limit, we compute the scattering amplitudes of the scalar off the extremal black holes and find perfect agreement with the CFT prediction. Furthermore we study the holographic description of the generic four dimensional non-extremal Kerr-Bolt-AdS-dS black holes. We find that if focusing on the near-horizon region, for the massless scalar scattering in the low-frequency limit, the radial equation could still be rewritten as the $SL(2,R)$ quadratic Casimir, suggesting the existence of dual 2D description. We read the temperatures of the dual CFT from the conformal coordinates and obtain the central charges by studying the near-horizon geometry of near-extremal black holes. We recover the macroscopic entropy from the microscopic counting. We also show that for the superradiant scattering, the retarded Green's functions and the corresponding absorption cross sections are in perfect match with CFT prediction.Comment: 17 pages, typos corrected, references adde

Role of Inter-Electron Interaction in the Pseudo-Gap Opening in High T c_c Tunneling Experiments

The analysis of tunneling experiments showing the pseudogap type behavior is carried out based on the idea of the renormalization of density of states due to the inter-electron interaction in the Cooper channel (superconducting fluctuations contribution in tunneling current). It is demonstrated that the observed kink of the zero-bias conductance $G(0,T)$ of $YBaCuO/Pb$ junctions in the vicinity of $T_c$ can be explained in terms of fluctuation theory in a quite wide range of temperature above $T_c$, using the values of microscopic parameters of the $YBaCuO$ electron spectrum taken from independent experiments. The approach proposed also permits to explain qualitatively the shape of the tunneling anomalies in $G(V,T)$ and gives a correct estimate for the pseudogap position and amplitude observed in the experiments on $BiSrCaCuO$ junctions.Comment: 5 pages, 3 figure

The impact of zinc oxide particle morphology as an antimicrobial and when incorporated in poly(3-hydroxybutyrate-co-3-hydroxyvalerate) films for food packaging and food contact surfaces applications

In this work, zinc oxide (ZnO) micron and nano sized-particles with different morphologies were synthesized by aqueous precipitation and evaluated as antimicrobial agents against foodborne pathogens. The most effective bactericide system was selected to prepare active poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) films by three different methods (i) direct melt-mixing, (ii) melt-mixing of preincorporated ZnO into PHBV18 (18 mol% valerate content) fiber mats made by electrospinning, and, (iii) as a coating of the annealed electrospun PHBV18/ZnO fiber mats over compression molded PHBV. Results showed that ZnO successfully improved the thermal stability of the PHBV18, being the preincorporation method the most efficient in mitigating the negative impact that the PHBV18 had on the thermal stability, barrier and optical properties of the PHBV films. Similar behavior was found for the coating structure although this film showed effective and prolonged antibacterial activity against Listeria monocytogenes. This study highlights the suitability of the PHBV/ZnO nanostructures for active food packaging and food contact surface applications.This work was financially supported by the Spanish Ministry of Economy and Competitiveness (MAT2012-38947-C02-01 and AGL2015-63855-C2-1-R). J.L. Castro-Mayorga is supported by the Administrative Department of Science, Technology and Innovation (Colciencias) of Colombian Government. M. J. Fabra is recipient of a Ramon y Cajal contract from the Spanish Ministry of Economy and Competitiveness.Peer reviewe

Negative c-axis magnetoresistance in graphite

We have studied the c-axis interlayer magnetoresistance (ILMR), R_c(B) in graphite. The measurements have been performed on strongly anisotropic highly oriented pyrolytic graphite (HOPG) samples in magnetic field up to B = 9 T applied both parallel and perpendicular to the sample c-axis in the temperature interval 2 K < T < 300 K. We have observed negative magnetoresistance, dR_c/dB < 0, for B || c-axis above a certain field B_m(T) that reaches its minimum value B_m = 5.4 T at T = 150 K. The results can be consistently understood assuming that ILMR is related to a tunneling between zero-energy Landau levels of quasi-two-dimensional Dirac fermions, in a close analogy with the behavior reported for alpha-(BEDT-TTF)2I3 [N. Tajima et al., Phys. Rev. Lett. 102, 176403 (2009)], another multilayer Dirac electron system.Comment: 14 pages, including 4 figure

Determination of 2,4,6-trichloroanisole by cyclic voltammetry

The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia

Magnetic fields in cosmic particle acceleration sources

We review here some magnetic phenomena in astrophysical particle accelerators associated with collisionless shocks in supernova remnants, radio galaxies and clusters of galaxies. A specific feature is that the accelerated particles can play an important role in magnetic field evolution in the objects. We discuss a number of CR-driven, magnetic field amplification processes that are likely to operate when diffusive shock acceleration (DSA) becomes efficient and nonlinear. The turbulent magnetic fields produced by these processes determine the maximum energies of accelerated particles and result in specific features in the observed photon radiation of the sources. Equally important, magnetic field amplification by the CR currents and pressure anisotropies may affect the shocked gas temperatures and compression, both in the shock precursor and in the downstream flow, if the shock is an efficient CR accelerator. Strong fluctuations of the magnetic field on scales above the radiation formation length in the shock vicinity result in intermittent structures observable in synchrotron emission images. Resonant and non-resonant CR streaming instabilities in the shock precursor can generate mesoscale magnetic fields with scale-sizes comparable to supernova remnants and even superbubbles. This opens the possibility that magnetic fields in the earliest galaxies were produced by the first generation Population III supernova remnants and by clustered supernovae in star forming regions.Comment: 30 pages, Space Science Review