2,078 research outputs found

    Thermodynamics of Black Holes in Massive Gravity

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    We present a class of charged black hole solutions in an (n+2)n+2)-dimensional massive gravity with a negative cosmological constant, and study thermodynamics and phase structure of the black hole solutions both in grand canonical ensemble and canonical ensemble. The black hole horizon can have a positive, zero or negative constant curvature characterized by constant kk. By using Hamiltonian approach, we obtain conserved charges of the solutions and find black hole entropy still obeys the area formula and the gravitational field equation at the black hole horizon can be cast into the first law form of black hole thermodynamics. In grand canonical ensemble, we find that thermodynamics and phase structure depends on the combination kμ2/4+c2m2k -\mu^2/4 +c_2 m^2 in the four dimensional case, where μ\mu is the chemical potential and c2m2c_2m^2 is the coefficient of the second term in the potential associated with graviton mass. When it is positive, the Hawking-Page phase transition can happen, while as it is negative, the black hole is always thermodynamically stable with a positive capacity. In canonical ensemble, the combination turns out to be k+c2m2k+c_2m^2 in the four dimensional case. When it is positive, a first order phase transition can happen between small and large black holes if the charge is less than its critical one. In higher dimensional (n+25n+2 \ge 5) case, even when the charge is absent, the small/large black hole phase transition can also appear, the coefficients for the third (c3m2c_3m^2) and/or the fourth (c4m2c_4m^2) terms in the potential associated with graviton mass in the massive gravity can play the same role as the charge does in the four dimensional case.Comment: Latex 19 pages with 8 figure

    Rana grylio virus 43R encodes an envelope protein involved in virus entry

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    Rana grylio virus (RGV), a member of genus Ranavirus in the family Iridoviridae, is a viral pathogen infecting aquatic animal. RGV 43R has homologues only in Ranavirus and contains a transmembrane (TM) domain, but its role in RGV infection is unknown. In this study, 43R was determined to be associated with virion membrane. The transcripts encoding 43R and the protein itself appeared late in RGV-infected EPC cells and its expression was blocked by viral DNA replication inhibitor, indicating that 43R is a late expressed protein. Subcellular localization showed that 43R-EGFP fusion protein distributed in cytoplasm of EPC cells and that TM domain is essential for its distribution in cytoplasm. 43R-EGFP fusion protein colocalized with viral factories in RGV-infected cells. A recombinant RGV deleting 43R (43R-RGV) was constructed by homologous recombination to investigate its role in virus infection. Compared with wild type RGV, the ability of 43R-RGV to induce the cytopathic effect and its virus titers were significantly reduced. Furthermore, it is revealed that 43R deletion significantly inhibited viral entry but did not influence viral DNA replication by measuring and comparing the DNA levels of RGV and 43R-RGV in the infected cells at the early stage of infection. RGV neutralization with anti-43R serum reduced the virus titer. Therefore, these data showed that RGV 43R is a late gene that encodes an envelope protein involved in RGV entry.</p

    A multimodal approach to attitudes towards Tibet in Chinese language textbooks

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    Drawing on an examination of Chinese language textbooks for Tibetan ethnic students in the Tibet Autonomous Region of mainland China, this study scrutinises the representation of Tibetan images and the official attitude towards Tibet embedded in the textbooks. Using multimodal discourse analysis (MDA), the paper investigates how government perceptions of Tibet are constructed through the co-deployment of visual and textual semiotic resources in Chinese language textbooks. This study suggests an overall positive attitude towards Tibet shown in the textbooks. However, the references to Tibet or Tibetans are usually situated as topics of the ‘past’, which indicates a sense of their being uncivilised or backwards. The positive yet stereotyped portrayal of Tibet is in line with national identity construction to ensure a unified nation-state. This study examines both text and image in textbooks in order to understand state ideologies and official attitudes towards a minority group

    Improving eye–computer interaction interface design: Ergonomic investigations of the optimum target size and gaze-triggering dwell time

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    The Midas touch is reflected by the interactive feedback of interface functional elements, and a low level of spatial accuracy is related to the interaction area. This study tried to solve these two problems from the perspective of human-computer interactions and ergonomics. Two experiments were conducted to explore the optimum target size and gaze-triggering dwell time of the eye–computer interaction (ECI) system. Experimental Series 1 was used as the pre-experiment to identify the size that has a greater task completion rate. Experimental Series 2 was used as the main experiment to investigate the optimum gaze-triggering dwell time by using a comprehensive evaluation of the task completion rate, reaction time, and NASA-TLX (Task Load Index). In Experimental Series 1, the optimal element size was determined to be 256 × 256p x2. The conclusion of Experimental Series 2 was that when the dwell time is set to 600 ms, the efficiency of the interface is the highest, and the task load of subjects is minimal as well. Finally, the results of Experiment Series 1 and 2 have positive effects on improving the usability of the interface. The optimal control size and the optimal dwell time obtained from the experiments have certain reference and application value for interface design and software development of the ECI system
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