Poly[μ2-aqua-aqua­(μ3-1H-benzimidazole-5,6-dicarboxyl­ato-κ3 N 3:O 5:O 5′)manganese(II)]

In the title complex, [Mn(C9H4N2O4)(H2O)2]n, the MnII atom is in a distorted octa­hedral coordination completed by one N atom from one 1H-benzimidazole-5,6-dicarboxyl­ate ligand, two O atoms from two different 1H-benzimidazole-5,6-dicarboxyl­ate ligands, and three O atoms from three water mol­ecules. Two bridging water mol­ecules and two bridging carboxyl­ate groups from a 1H-benzimidazole-5,6-dicarboxyl­ate ligand connect two MnII ions into a dimeric structure. In the crystal, extensive inter­molecular O—H⋯O, N—H⋯O and C—H⋯O hydrogen bonding forms a three-dimensional network

Formation of a tiny flux rope in the center of an active region driven by magnetic flux emergence, convergence, and cancellation

Flux ropes are generally believed to be core structures of solar eruptions that are significant for the space weather, but their formation mechanism remains intensely debated. We report on the formation of a tiny flux rope beneath clusters of active region loops on 2018 August 24. Combining the high-quality multiwavelength observations from multiple instruments, we studied the event in detail in the photosphere, chromosphere, and corona. In the source region, the continual emergence of two positive polarities (P1 and P2) that appeared as two pores (A and B)is unambiguous. Interestingly, P2 and Pore B slowly approached P1 and Pore A, implying a magnetic flux convergence. During the emergence and convergence, P1 and P2 successively interacted with a minor negative polarity (N3) that emerged, which led to a continuous magnetic flux cancellation. As a result, the overlying loops became much sheared and finally evolved into a tiny twisted flux rope that was evidenced by a transient inverse S-shaped sigmoid, the twisted filament threads with blueshift and redshift signatures, and a hot channel. All the results show that the formation of the tiny flux rope in the center of the active region was closely associated with the continuous magnetic flux emergence, convergence, and cancellation in the photosphere. Hence, we suggest that the magnetic flux emergence, convergence, and cancellation are crucial for the formation of the tiny flux rope

Expressions of ECE-CYC2 clade genes relating to abortion of both dorsal and ventral stamens in Opithandra (Gesneriaceae)

<p>Abstract</p> <p>Background</p> <p>ECE-CYC2 clade genes known in patterning floral dorsoventral asymmetry (zygomorphy) in <it>Antirrhinum majus </it>are conserved in the dorsal identity function including arresting the dorsal stamen. However, it remains uncertain whether the same mechanism underlies abortion of the ventral stamens, an important morphological trait related to evolution and diversification of zygomorphy in Lamiales <it>sensu lato</it>, a major clade of predominantly zygomorphically flowered angiosperms. <it>Opithandra </it>(Gesneriaceae) is of particular interests in addressing this question as it is in the base of Lamiales <it>s.l</it>., an early representative of this type zygomorphy.</p> <p>Results</p> <p>We investigated the expression patterns of four ECE-CYC2 clade genes and two putative target <it>cyclinD3 </it>genes in <it>Opithandra </it>using RNA <it>in situ </it>hybridization and RT-PCR. <it>OpdCYC </it>gene expressions were correlated with abortion of both dorsal and ventral stamens in <it>Opithandra</it>, strengthened by the negatively correlated expression of their putative target <it>OpdcyclinD3 </it>genes. The complement of <it>OpdcyclinD3 </it>to <it>OpdCYC </it>expressions further indicated that <it>OpdCYC </it>expressions were related to the dorsal and ventral stamen abortion through negative effects on <it>OpdcyclinD3 </it>genes.</p> <p>Conclusion</p> <p>These results suggest that ECE-CYC2 clade TCP genes are not only functionally conserved in the dorsal stamen repression, but also involved in arresting ventral stamens, a genetic mechanism underlying the establishment of zygomorphy with abortion of both the dorsal and ventral stamens evolved in angiosperms, especially within Lamiales <it>s.l</it>.</p

Inelastic Final-State Interactions of B→VV→πKB \to VV \to \pi K Processes

We study the final-state interactions in $B \to \pi K$ decays through $B \to VV \to \pi K$ processes where the inelastic rescattering occurs via single pion exchange. The next-to-leading order low energy effective Hamiltonian and BSW model are used to evaluate the weak transition matrix elements and the final-state interactions. We found that the final-state interaction effects in $B \to \rho K^* \to \pi K$ processes are significant. The Fleischer-Mannel relation about the CKM angle $\gamma$ may be significantly modified.Comment: Latex, 14 pages, with 1 figures and 2 table