Role of quark-interchange processes in evolution of mesonic matter

We divide the cross section for a meson-meson reaction into three parts. The first part is for the quark-interchange process, the second for quark-antiquark annihilation processes and the third for resonant processes. Master rate equations are established to yield time dependence of fugacities of pions, rhos, kaons and vetor kaons. The equations include cross sections for inelastic scattering of pions, rhos, kaons and vector kaons. Cross sections for quark-interchange-induced reactions, that were obtained in a potential model, are parametrized for convenient use. The number densities of pion and rho (kaon and vector kaon) are altered by quark-interchange processes in equal magnitudes but opposite signs. The master rate equations combined with the hydrodynamic equations for longitudinal and transverse expansion are solved with many sets of initial meson fugacities. Quark-interchange processes are shown to be important in the contribution of the inelastic meson-meson scattering to evolution of mesonic matter.Comment: 28 pages, 1 figure, 8 table

Generation of Two-Flavor Vortex Atom Laser from a Five-State Medium

Two-flavor atom laser in a vortex state is obtained and analyzed via electromagnetically induced transparency (EIT) technique in a five-level $M$ type system by using two probe lights with $\pm z$-directional orbital angular momentum $\pm l\hbar$, respectively. Together with the original transfer technique of quantum states from light to matter waves, the present result can be extended to generate continuous two-flavor vortex atom laser with non-classical atoms.Comment: 5 pages, 1 figure; The previous version (v2) is a wrong one; this is the published versio

Towards realistic f(T)f(T) models with nonminimal torsion-matter coupling extension

Using the observation data of SNeIa, CMB and BAO, we establish two concrete $f(T)$ models with nonminimal torsion-matter coupling extension. We study in detail the cosmological implication of our models and find they are successful in describing the observation of the Universe, its large scale structure and evolution. In other words, these models do not change the successful aspects of $\Lambda$CDM scenario under the error band of fitting values as describing the evolution history of the Universe including radiation-dominated era, matter-dominated era and the present accelerating expansion. Meanwhile, the significant advantage of these models is that they could avoid the cosmological constant problem of $\Lambda$CDM. A joint analysis is performed by using the data of CMB+BAO+JLA, which leads to $\Omega_{m0}=0.255\pm 0.010, \Omega_{b0}h^2=0.0221\pm 0.0003$ and $H_0=68.54\pm 1.27$ for model I and $\Omega_{m0}=0.306\pm 0.010, \Omega_{b0}h^2=0.0225\pm 0.0003$ and $H_0=60.97\pm 0.44$ for model II at 1$\sigma$ confidence level. The evolution of the decelaration parameter $q(a)$ and the effective equation of state $w_{DE}(a)$ are displayed. Furthermore, The resulted age of the Universe from our models is consistent with the ages of the oldest globular clusters. As for the fate of the Universe, model I results in a de Sitter accelerating phase while model II appears a power-law one, even though $w_{DE0}< -1$ makes model I look like a phantom at present time.Comment: 12 pages, 5 figure

Correlated Quantum Memory: Manipulating Atomic Entanglement via Electromagnetically Induced Transparency

We propose a feasible scheme of quantum state storage and manipulation via electromagnetically induced transparency (EIT) in flexibly $united$ multi-ensembles of three-level atoms. For different atomic array configurations, one can properly steer the signal and the control lights to generate different forms of atomic entanglement within the framework of linear optics. These results shed new light on designing the versatile quantum memory devices by using, e.g., an atomic grid.Comment: 5 pages, 1 figur

Comparative transcriptome analysis and marker development of two closely related Primrose species (Primula poissonii and Primula wilsonii)

BACKGROUND: Primula species are important early spring garden plants with a centre of diversity and speciation in the East Himalaya-Hengduan Mountains in Western China. Studies on population genetics, speciation and phylogeny of Primula have been impeded by a lack of genomic resources. In the present study, we sequenced the transcriptomes of two closely related primrose species, Primula poissonii and Primula wilsonii, using short reads on the Illumina Genome Analyzer platform. RESULTS: We obtained 55,284 and 55,011 contigs with N50 values of 938 and 1,085 for P. poissonii and P. wilsonii, respectively, and 6,654 pairs of putative orthologs were identified between the two species. Estimations of non-synonymous/synonymous substitution rate ratios for these orthologs indicated that 877 of the pairs may be under positive selection (Ka/Ks > 0.5), and functional enrichment analysis revealed that significant proportions of the orthologs were in the categories DNA repair, stress resistance, which may provide some hints as to how the two closely related Primula species adapted differentially to extreme environments, such as habitats characterized by aridity, high altitude and high levels of ionizing radiation. It was possible for the first time to estimate the divergence time between the radiated species pair, P. poissonii and P. wilsonii; this was found to be approximately 0.90 ± 0.57 Mya, which falls between the Donau and Gunz glaciation in the Middle Pleistocene. Primers based on 54 pairs of orthologous SSR-containing sequences between the two Primula species were designed and verified. About half of these pairs successfully amplified for both species. Of the 959 single copy nuclear genes shared by four model plants (known as APVO genes), 111 single copy nuclear genes were verified as being present in both Primula species and exon-anchored and intron-spanned primers were designed for use. CONCLUSION: We characterized the transcriptomes for the two Primula species, and produced an unprecedented amount of genomic resources for these important garden plants. Evolutionary analysis of these two Primula species not only revealed a more precise divergence time, but also provided some novel insights into how differential adaptations occurred in extreme habitats. Furthermore, we developed two sets of genetic markers, single copy nuclear genes and nuclear microsatellites (EST-SSR). Both these sets of markers will facilitate studies on the genetic improvement, population genetics and phylogenetics of this rapidly adapting taxon

Technique of quantum state transfer for a double Lambda atomic beam

The transfer technique of quantum states from light to collective atomic excitations in a double $\Lambda$ type system is extended to matter waves in this paper, as a novel scheme towards making a continuous atom laser. The intensity of the output matter waves is found to be determined by the initial relative phase of the two independent coherent probe lights, which may indicate an interesting method for the measurement of initial relative phase of two independent light sources.Comment: 5 pages, 2 figure

Information Flow Analysis of Interactome Networks

Recent studies of cellular networks have revealed modular organizations of genes and proteins. For example, in interactome networks, a module refers to a group of interacting proteins that form molecular complexes and/or biochemical pathways and together mediate a biological process. However, it is still poorly understood how biological information is transmitted between different modules. We have developed information flow analysis, a new computational approach that identifies proteins central to the transmission of biological information throughout the network. In the information flow analysis, we represent an interactome network as an electrical circuit, where interactions are modeled as resistors and proteins as interconnecting junctions. Construing the propagation of biological signals as flow of electrical current, our method calculates an information flow score for every protein. Unlike previous metrics of network centrality such as degree or betweenness that only consider topological features, our approach incorporates confidence scores of protein–protein interactions and automatically considers all possible paths in a network when evaluating the importance of each protein. We apply our method to the interactome networks of Saccharomyces cerevisiae and Caenorhabditis elegans. We find that the likelihood of observing lethality and pleiotropy when a protein is eliminated is positively correlated with the protein's information flow score. Even among proteins of low degree or low betweenness, high information scores serve as a strong predictor of loss-of-function lethality or pleiotropy. The correlation between information flow scores and phenotypes supports our hypothesis that the proteins of high information flow reside in central positions in interactome networks. We also show that the ranks of information flow scores are more consistent than that of betweenness when a large amount of noisy data is added to an interactome. Finally, we combine gene expression data with interaction data in C. elegans and construct an interactome network for muscle-specific genes. We find that genes that rank high in terms of information flow in the muscle interactome network but not in the entire network tend to play important roles in muscle function. This framework for studying tissue-specific networks by the information flow model can be applied to other tissues and other organisms as well.StatisticsVersion of Recor

Quantum interface between frequency-uncorrelated down-converted entanglement and atomic-ensemble quantum memory

Photonic entanglement source and quantum memory are two basic building blocks of linear-optical quantum computation and long-distance quantum communication. In the past decades, intensive researches have been carried out, and remarkable progress, particularly based on the spontaneous parametric down-converted (SPDC) entanglement source and atomic ensembles, has been achieved. Currently, an important task towards scalable quantum information processing (QIP) is to efficiently write and read entanglement generated from a SPDC source into and out of an atomic quantum memory. Here we report the first experimental realization of a quantum interface by building a 5 MHz frequency-uncorrelated SPDC source and reversibly mapping the generated entangled photons into and out of a remote optically thick cold atomic memory using electromagnetically induced transparency. The frequency correlation between the entangled photons is almost fully eliminated with a suitable pump pulse. The storage of a triggered single photon with arbitrary polarization is shown to reach an average fidelity of 92% for 200 ns storage time. Moreover, polarization-entangled photon pairs are prepared, and one of photons is stored in the atomic memory while the other keeps flying. The CHSH Bell's inequality is measured and violation is clearly observed for storage time up to 1 microsecond. This demonstrates the entanglement is stored and survives during the storage. Our work establishes a crucial element to implement scalable all-optical QIP, and thus presents a substantial progress in quantum information science.Comment: 28 pages, 4 figures, 1 tabl