Dark Left-Right Gauge Model: SU(2)_R Phenomenology

In the recently proposed dark left-right gauge model of particle interactions, the left-handed fermion doublet $(\nu,e)_L$ is connected to its right-handed counterpart $(n,e)_R$ through a scalar bidoublet, but $\nu_L$ couples to $n_R$ only through $\phi_1^0$ which has no vacuum expectation value. The usual R parity, i.e. $R = (-)^{3B+L+2j}$, can be defined for this nonsupersymmetric model so that both $n$ and $\Phi_1$ are odd together with $W_R^\pm$. The lightest $n$ is thus a viable dark-matter candidate (scotino). Here we explore the phenomenology associated with the $SU(2)_R$ gauge group of this model, which allows it to appear at the TeV energy scale. The exciting possibility of $Z' \to 8$ charged leptons is discussed.Comment: 12 pages, 2 figure

Neutral SU(2) Gauge Extension of the Standard Model and a Vector-Boson Dark-Matter Candidate

If the standard model of particle interactions is extended to include a neutral SU(2)_N gauge factor, with SU(3)_C x SU(2)_L x U(1)_Y x SU(2)_N embedded in E_6 or [SU(3)]^3, a conserved generalized R parity may appear. As a result, we have the first example of a possible dark-matter candidate X_1 which is a non-Abelain vector boson. Using current data, its mass is predicted to be less than about 1 TeV. The associated Z' of this model, as well as some signatures of the Higgs sector, should then be observable at the LHC (Large Hadron Collider).Comment: 10 pages, 1 figure; version accepted in PL

gem-Dibromocyclopropanes and enzymatically derived cis-1,2-dihydrocatechols as building blocks in alkaloid synthesis

The application of the title building blocks, the 6,6-dibromobicyclo[3.1.0]hexanes and the cis-1,2-dihydrocatechols, to the total synthesis of crinine and lycorinine alkaloids is described.We thank the Australian Research Council and the Institute of Advanced Studies for generous financial support

The c-terminal extension of a hybrid immunoglobulin A/G heavy chain is responsible for its Golgi-mediated sorting to the vacuole

We have assessed the ability of the plant secretory pathway to handle the expression of complex heterologous proteins by investigating the fate of a hybrid immunoglobulin A/G in tobacco cells. Although plant cells can express large amounts of the antibody, a relevant proportion is normally lost to vacuolar sorting and degradation. Here we show that the synthesis of high amounts of IgA/G does not impose stress on the plant secretory pathway. Plant cells can assemble antibody chains with high efficiency and vacuolar transport occurs only after the assembled immunoglobulins have traveled through the Golgi complex. We prove that vacuolar delivery of IgA/G depends on the presence of a cryptic sorting signal in the tailpiece of the IgA/G heavy chain. We also show that unassembled light chains are efficiently secreted as monomers by the plant secretory pathway

Topological Protection of Coherence in Noisy Open Quantum Systems

We consider topological protection mechanisms in dissipative quantum systems in the presence of quenched disorder, with the intent to prolong coherence times of qubits. The physical setting is a network of qubits and dissipative cavities whose coupling parameters are tunable, such that topological edge states can be stabilized. The evolution of a fiducial qubit is entirely determined by a non-Hermitian Hamiltonian which thus emerges from a bona-fide physical process. It is shown how even in the presence of disorder winding numbers can be defined and evaluated in real space, as long as certain symmetries are preserved. Hence we can construct the topological phase diagrams of noisy open quantum models, such as the non-Hermitian disordered Su-Schrieffer- Heeger dimer model and a trimer model that includes longer-range couplings. In the presence of competing disorder parameters, interesting re-entrance phenomena of topologically non-trivial sectors are observed. This means that in certain parameter regions, increasing disorder drastically increases the coherence time of the fiducial qubit

Chiral mononuclear lanthanide complexes derived from chiral Schiff bases: Structural and magnetic studies

A new family of mononuclear lanthanide complexes with formula [LnIII(L)Cl3] (Ln = Eu (1), Tb (2), Dy (3), Er (4), Yb (5)) and L = N,N0-bis((1,2-diphenyl-(pyridine-2-yl)methylene)-(R,R/S,S)-ethane-1,2-diamine has been obtained employing enantiomerically pure Schiff bases. The complexes have been structurally characterized using X-ray single crystal and powder diffraction. Their dynamic magnetic properties have been studied showing that this family presents slow relaxation of the magnetization under certain conditions and confirms the different behavior of each LnIII cations in isostructural complexes: only the Er one possibly relaxing via an overbarrier Orbach process, while Raman process dominates for Dy and Yb derivative

One- and two-dimensional higher-point conformal blocks as free-particle wavefunctions in AdS3⊗m_3^{\otimes m}

We establish that all of the one- and two-dimensional global conformal blocks are, up to some choice of prefactor, free-particle wavefunctions in tensor products of AdS$_3$ or limits thereof. Our first core observation is that the six-point comb-channel conformal blocks correspond to free-particle wavefunctions on an AdS$_3$ constructed directly in cross-ratio space. This construction generalizes to blocks for a special class of diagrams, which are determined as free-particle wavefunctions in tensor products of AdS$_3$. Conformal blocks for all the remaining topologies are obtained as limits of the free wavefunctions mentioned above. Our results show directly that the integrable models associated with all one- and two-dimensional conformal blocks can be seen as limits of free theory, and manifest a relation between AdS and CFT kinematics that lies outside of the standard AdS/CFT dictionary. We complete the discussion by providing explicit Feynman-like rules that can be used to work out blocks for all topologies, as well as a Mathematica notebook that allows simple computation of Casimir equations and series expansions for blocks, by requiring just an OPE diagram as input.Comment: 39 pages + an appendix, 18 figures, Mathematica notebook attache

Lie symmetries of nonlinear boundary value problems

Nonlinear boundary value problems (BVPs) by means of the classical Lie symmetry method are studied. A new definition of Lie invariance for BVPs is proposed by the generalization of existing those on much wider class of BVPs. A class of two-dimensional nonlinear boundary value problems, modeling the process of melting and evaporation of metals, is studied in details. Using the definition proposed, all possible Lie symmetries and the relevant reductions (with physical meaning) to BVPs for ordinary differential equations are constructed. An example how to construct exact solution of the problem with correctly-specified coefficients is presented and compared with the results of numerical simulations published earlier.Comment: Published versio

Genetic and biochemical analyses of chromosome and plasmid gene homologues encoding ICL and ArCP domains in Vibrioanguillarum strain 775

Anguibactin, the siderophore produced by Vibrio anguillarum 775 is synthesized from 2,3-dihydroxybenzoic acid (DHBA), cysteine and hydroxyhistamine via a nonribosomal peptide synthetase (NRPS) mechanism. Most of the genes encoding anguibactin biosynthetic proteins are harbored by the pJM1 plasmid. In this work we report the identification of a homologue of the plasmid-encoded angB on the chromosome of strain 775. The product of both genes harbor an isochorismate lyase (ICL) domain that converts isochorismic acid to 2,3-dihydro-2,3-dihydroxybenzoic acid, one of the steps of DHBA synthesis. We show in this work that both ICL domains are functional in the production of DHBA in V. anguillarum as well as in E. coli. Substitution by alanine of the aspartic acid residue in the active site of both ICL domains completely abolishes their isochorismate lyase activity in vivo. The two proteins also carry an aryl carrier protein (ArCP) domain. In contrast with the ICL domains only the plasmid encoded ArCP can participate in anguibactin production as determined by complementation analyses and site-directed mutagenesis in the active site of the plasmid encoded protein, S248A. The site-directed mutants, D37A in the ICL domain and S248A in the ArCP domain of the plasmid encoded AngB were also tested in vitro and clearly show the importance of each residue for the domain function and that each domain operates independently.