We construct a four dimensional chiral N = 1 space-time supersymmetric perturbative Type I vacuum corresponding to a compactification on a toroidal Z2 ⊗ Z2 ⊗ Z3 orbifold with a discrete Wilson line. This model is non-perturbative from the heterotic viewpoint. It has three chiral families in the SU(4)c⊗SU(2)w ⊗U(1) subgroup of the total gauge group. We compute the tree-level superpotential in th...

A supersymmetric vacuum has to obey a set of constraints on fluxes as well as first order differential equations defined by the G-structures of the internal manifold. We solve these equations for type IIB supergravity with SU(3) structures. The 6-dimensional internal manifold has to be complex, the axion/dilaton is in general non-holomorphic and a cosmological constant is only possible if the S...

We investigate string solutions to the classical equations of motion (" classical QCD strings ") for a dual Ginzburg-Landau model corresponding to SU (3) gluodynamics in an abelian projection. For a certain relation between couplings of the model the string solutions are defined by first order differential equations. These solutions are related to vortex configurations of the Abelian Higgs mode...

We studied the large-amplitude SU UMa-type dwarf nova V344 Lyr. A combination of our observations and reports to VSNET has yielded an extensive coverage of outbursts between 1994 July and 2001 June. The analysis of this data showed a mean supercycle length of 109.6 d. This value is one of the smallest among known SU UMa-type dwarf novae (except unusual ER UMa-type dwarf novae). The outburst amp...

Multiple auxotrophic strains of Bacillus subtilis 168 were tested for joint one-step reversion of two or more auxotrophic markers to the wild-type phenotype. Mu8u5u5, a strain requiring leucine, methionine, and threonine, yielded revertants that grew without added methionine or threonine and proved to have a suppressor gene. When transferred by transformation with deoxyribonucleic acid, this su...