Dimerized and trimerized phases for spin-2 Bosons in a one-dimensional optical lattice

We study the phase diagram for spin-2 bosons loaded in a one-dimensional optical lattice. By using non-Abelian density matrix renormalization group (DMRG) method we identify three possible phases: ferromagnetic, dimerized, and trimerized phases. We sketch the phase boundaries based on DMRG. We illustrate two methods for identifying the phases. The first method is based on the spin-spin correlation function while in the second method one observes the excitation gap as a dimerization or a trimerization superlattice is imposed. The advantage of the second method is that it can also be easily implemented in experiments. By using the scattering lengths in the literature we estimate that $^{83}$Rb, $^{23}$Na, and $^{87}$Rb be ferromagnetic, dimerized, and trimerized respectively.Comment: 4 pages, 3 figures. Add acknowledgemen

Quantum Critical Spin-2 Chain with Emergent SU(3) Symmetry

We study the quantum critical phase of a SU(2) symmetric spin-2 chain obtained from spin-2 bosons in a one-dimensional lattice. We obtain the scaling of the entanglement entropy and finite-size energies by exact diagonalization and density-matrix renormalization group methods. From the numerical results of the energy spectrum, central charge, and scaling dimension we identify the conformal field theory describing the whole critical phase to be the SU(3)$_1$ Wess-Zumino-Witten model. We find that while in the whole critical phase the Hamiltonian is only SU(2) invariant, there is an emergent SU(3) symmetry in the thermodynamic limit

The DWT Power Spectrum of the two-degree Field Galaxy Redshift Survey

The power spectrum of the two-degree Field Galaxy Redshift Survey (2dFGRS) sample is estimated with the discrete wavelet transform (DWT) method. The DWT power spectra within $0.04 <k< 2.3 h$Mpc$^{-1}$ are measured for three volume-limited samples defined in connective absolute magnitude bins $-19 \sim -18$, $-20 \sim -19$ and $-21 \sim -20$. We show that the DWT power spectrum can effectively distinguish $\Lambda$CDM models of $\sigma_8=0.84$ and $\sigma_8=0.74$. We adopt maximum likelihood method to perform three-parameter fitting with bias parameter $b$, pairwise velocity dispersion $\sigma_{pv}$ and redshift distortion parameter $\beta=\Omega_m^{0.6}/b$ to the measured DWT power spectrum. Fitting results denotes that in a $\sigma_8=0.84$ universe the best fitted $\Omega_m$ given by the three samples are consistent in the range $0.28 \sim 0.36$, and the best fitted $\sigma_{pv}$ are $398^{+35}_{-27}$, $475^{+37}_{-29}$ and $550 \pm 20$km/s for the three samples, respectively. However in the model of $\sigma_8=0.74$, our three samples give very different values of $\Omega_m$. We repeat the fitting by using empirical formula of redshift distortion. The result of the model of low $\sigma_8$ is still poor, especially, one of the best value $\sigma_{pv}$ is as large as $10^3$km/s. The power spectrum of 2dFGRS seems in disfavor of models with low amplitude of density fluctuations.Comment: 11 pages, 9 figures. submitted to MNRAS. submitted to MNRA

A new stripe rust resistance gene transferred from Thinopyrum intermedium to hexaploid wheat (Triticum aestivum)

Wheat stripe rust (Puccinia striiforis f. sp. tritici) races CYR31 and CYR32, prevalent in China, are virulent to many wheat stripe rust resistance genes (Yr genes). To expand the availability of effective resistance to CYR31 and CYR32, stripe rust resistance was transferred from intermediate wheatgrass (Thinopyrum intermedium) to common wheat (Triticum aestivum). The susceptible wheat cultivar CM107 was crossed with amphiploid TAI7047, derived from the wide cross Taiyuan768/Thinopyrum intermedium//76(64). Two wheat lines originating from the cross, YU24 and YU25, were resistant to CYR31 and CYR32. Pedigree analysis showed that the resistance to stripe rust in YU24 and YU25 originated from intermediate wheatgrass. Genetic analyses indicated that the resistance to stripe rust is controlled by a single dominant gene. Allelic tests determined that the resistance gene(s) in YU24 and YU25 are identical. The new gene has temporarily been designated as YrYU25. SSR and RAPD analyses showed that YrYU25 was introduced by cryptic translocation into common wheat.Les races CYR31 et CYR32 de la rouille jaune du blé (Puccinia striiforis f. sp. tritici), très répandues en Chine, sont virulentes pour plusieurs gènes de résistance à cette maladie (gènes Yr). Afin d'accroître la disponibilité d'une résistance efficace aux races CYR31 et CYR32, la résistance à la rouille jaune du blé a été transférée de l'agropyre intermédiaire (Thinopyrum intermedium) au blé tendre (Triticum aestivum). CM107, un cultivar de blé sensible, a été croisé avec l'amphiploïde AI7047 dérivé du croisement éloigné Taiyuan768/Thinopyrum intermedium//76(64). Deux lignées de blé provenant de ce croisement, soit YU24 et YU25, étaient résistantes aux races CYR31 et CYR32. Une analyse généalogique a démontré que la résistance à la rouille jaune du blé chez les lignées YU24 et YU25 provenait de l'agropyre intermédiaire. Des analyses génétiques ont indiqué que cette résistance était contrôlée par un seul gène dominant. Des tests d'allélisme ont révélé que le(s) gène(s) de résistance dans les lignées YU24 et YU25 étaient identiques. Le nouveau gène a temporairement été nommé YrYU25. Des analyses SSR et RAPD ont démontré que le gène YrYU25 avait été introduit dans le blé tendre par translocation cryptique

Molecular characterization of the envelope gene of dengue virus type 3 newly isolated in Guangzhou, China, during 2009–2010

SummaryBackgroundAfter an absence of 29 years, dengue virus type 3 (DENV-3) re-emerged in Guangzhou in 2009 and again in 2010. However, the geographical route by which the virus entered the city, and how it has changed genetically, remain unclear. Therefore, we carried out a comprehensive investigation into the molecular characteristics of the DENV-3 involved.MethodsThe envelope (E) genes of viruses isolated from dengue patients during the 2009–2010 epidemics were sequenced and compared with previously published E gene sequences of global representative DENV-3 strains available in GenBank, including isolates circulating in other provinces of China.ResultsA total of 13 isolates (seven from 2009 and six from 2010) were obtained from human serum samples. Phylogenetic analysis revealed that the isolates were grouped into three genotypes (I, III, and V) and then two clades within genotype III (genotype I from Indonesia, genotype III clade A from Côte d’Ivoire, genotype III clade B from Tanzania, and genotype V from Philippines). In addition, there were 1.3–9.0% and 0.5–3.9% differences in the nucleic and deduced amino acid sequences between the 2009 and 2010 strains, respectively.ConclusionsThe DENV-3 viruses from the period 2009–2010 were not from the continuous spread of an epidemic strain or the re-emergence of the 2009 strains in the 2-year period. The introduction of different DENV-3 genotypes following more than one geographical route was an important contributing factor to the 2009–2010 dengue epidemics in Guangzhou

catena-Poly[[[tetra­aqua­manganese(II)]-μ-4,4′-bipyridine] bis­(3-hydroxy­cinnamate) dihydrate]

The title compound, {[Mn(C10H8N2)(H2O)4](C9H7O3)2·2H2O}n, was obtained by the hydro­thermal reaction of manganese chloride with mixed 3-hydroxy­lcinnamic acid (H2 L) and 4,4′-bipyridine (4,4′-bipy) ligands. The structure contains [Mn(C10H8N2)(H2O)4]2+ cations with the MnII atoms lying on a centres of inversion and bridged into a linear chain along the a axis by 4,4′-bipy ligands, surrounded by HL − anions and uncoordinated water mol­ecules. Extensive O—H⋯O hydrogen-bonding and weak π–π inter­actions [centroid–centroid distance = 3.7572  (3) Å] between the constituents lead to the formation of a three-dimensional supra­molecular network