Real-Reward Testing for Probabilistic Processes (Extended Abstract)

We introduce a notion of real-valued reward testing for probabilistic processes by extending the traditional nonnegative-reward testing with negative rewards. In this richer testing framework, the may and must preorders turn out to be inverses. We show that for convergent processes with finitely many states and transitions, but not in the presence of divergence, the real-reward must-testing preorder coincides with the nonnegative-reward must-testing preorder. To prove this coincidence we characterise the usual resolution-based testing in terms of the weak transitions of processes, without having to involve policies, adversaries, schedulers, resolutions, or similar structures that are external to the process under investigation. This requires establishing the continuity of our function for calculating testing outcomes.Comment: In Proceedings QAPL 2011, arXiv:1107.074

Characterising Probabilistic Processes Logically

In this paper we work on (bi)simulation semantics of processes that exhibit both nondeterministic and probabilistic behaviour. We propose a probabilistic extension of the modal mu-calculus and show how to derive characteristic formulae for various simulation-like preorders over finite-state processes without divergence. In addition, we show that even without the fixpoint operators this probabilistic mu-calculus can be used to characterise these behavioural relations in the sense that two states are equivalent if and only if they satisfy the same set of formulae.Comment: 18 page

Impact of pEGFP mediated ING4 gene on growth of glioma U251 cells and its potential molecular mechanism

To investigate the impact of the inhibitor of growth family 4 (ING4) on growth of glioma cells (U251 cells) and its potential molecular mechanism, total RNA was extracted from the embryonic tissues and ING4 was amplified by RT-PCR and cloned into pEGFP-C2 vector. U251 cells were transfected with eukaryotic expression vector pEGFP-ING4 mediated by cationic polymers polyethylenimine (PEI). Flow cytometry and G418 were used to screen the cells successfully transfected with pEGFP-ING4. PEGFP-ING4 group, pEGFP group and blank control group (without transfection) were included in this study. Morphological examination, MTT assay and Hochest staining were employed to detect the proliferation and apoptosis of U251 cells. RT-PCR, immunohistochemitry and western blot were recruited to determine the mRNA and protein expression of ING4, respectively. ELISA was performed to measure the VEGF level in the supernatant of U251 cells. Sequencing of pEGFP-ING4 showed sequence correctness and the tranfection efficiency was 84% for pEGFP-ING4 and 82% for pEGFP. Results from RT-PCR, immunohistochemistry and western blot revealed significantly increased ING4 expression. When compared with the pEGFP group and blank group, the growth inhibition rate and apoptotic rate 72 h after transfection in the pEGFPING4 group were significantly higher (P < 0.05), but the VEGF content was not significantly changed (P > 0.05). ING4 can be highly expressed in the pEGFP-ING4 group and remarkably suppress the growth of U251 cells through inducing apoptosis but not suppressing VEGF expression.Key words: Inhibitor of growth family member 4, glioma, angiogenesis, vascular endothelial growth factor

Optimal nonlocal multipartite entanglement concentration based on projection measurements

We propose an optimal nonlocal entanglement concentration protocol (ECP) for multi-photon systems in a partially entangled pure state, resorting to the projection measurement on an additional photon. One party in quantum communication first performs a parity-check measurement on her photon in an N-photon system and an additional photon, and then she projects the additional photon into an orthogonal Hilbert space for dividing the original $N$-photon systems into two groups. In the first group, the N parties will obtain a subset of $N$-photon systems in a maximally entangled state. In the second group, they will obtain some less-entangled N-photon systems which are the resource for the entanglement concentration in the next round. By iterating the entanglement concentration process several times, the present ECP has the maximal success probability which is just equivalent to the entanglement of the partially entangled state. That is, this ECP is an optimal one.Comment: 5 pages, 4 figure

Efficient multipartite entanglement purification with the entanglement link from a subspace

We present an efficient multipartite entanglement purification protocol (MEPP) for N-photon systems in a Greenberger-Horne-Zeilinger state with parity-check detectors. It contains two parts. One is the conventional MEPP with which the parties can obtain a high-fidelity N-photon ensemble directly, similar to the MEPP with controlled-not gates. The other is our recycling MEPP in which the entanglement link is used to produce some $N$-photon entangled systems from entangled N'-photon subsystems (2 \leq N'<N) coming from the instances which are just discarded in all existing conventional MEPPs. The entangled N'-photon subsystems are obtained efficiently by measuring the photons with potential bit-flip errors. With these two parts, the present MEPP has a higher efficiency than all other conventional MEPPs.Comment: 17 pages, 9 figures, 2 tables. We correct the error in the address of the author in the published version (Phys. Rev. A 84, 052312 (2011)

Environment, morphology and stellar populations of bulgeless low surface brightness galaxies

Based on the Sloan Digital Sky Survey DR 7, we investigate the environment, morphology and stellar population of bulgeless low surface brightness (LSB) galaxies in a volume-limited sample with redshift ranging from 0.024 to 0.04 and $M_r$ $\leq$ $-18.8$. The local density parameter $\Sigma_5$ is used to trace their environments. We find that, for bulgeless galaxies, the surface brightness does not depend on the environment. The stellar populations are compared for bulgeless LSB galaxies in different environments and for bulgeless LSB galaxies with different morphologies. The stellar populations of LSB galaxies in low density regions are similar to those of LSB galaxies in high density regions. Irregular LSB galaxies have more young stars and are more metal-poor than regular LSB galaxies. These results suggest that the evolution of LSB galaxies may be driven by their dynamics including mergers rather than by their large scale environment.Comment: 12 pages, 13 figures, Accepted by A&