The product of safe Petri nets is a well known operation : it generalizes to concurrent systems the usual synchronous product of automata. In this paper, we consider a more general way of combining nets, called a pullback. The pullback operation generalizes the product to nets which interact both by synchronized transitions and/or by a shared sub-net (i.e. shared places and transitions). To obt...

We investigated the expression and activity of arginine transporters and endothelial nitric oxide synthase (eNOS) in human placental microvascular endothelial cells (HPMEC). Using RT-PCR amplification products for eNOS, CAT1, CAT2A, CAT2B, CAT4, 4F2hc (CD98), rBAT and the light chains y+LAT1, y+LAT2, and b0+T1 were detected in HPMEC, but not B0+. Immunohistochemistry and Western blotting confir...

Tomato (Lycopersicon esculentum Mill. cv. Moneymaker) plants are chilling sensitive, and do not naturally accumulate glycinebetaine (GB), a metabolite that functions as a stress protectant. We reported previously that exogenous GB application enhanced chilling tolerance in tomato. To understand its protective role better, we have further evaluated various parameters associated with improved tol...

In an attempt to improve stress tolerance of tomato (Lycopersicon esculentum) plants, an expression vector containing an Arabidopsis C-repeat/dehydration responsive element binding factor 1 (CBF1) cDNA driven by a cauliflower mosaic virus 35S promoter was transferred into tomato plants. Transgenic expression of CBF1 was proved by northern- and western-blot analyses. The degree of chilling toler...

Cassava (Manihot esculenta Crantz) plant resists water-deficit stress by shedding leaves leading to adaptive water-deficit condition. Transcriptomic, physiological, cellular, molecular, metabolic, and transgenic methods were used to study the mechanism of cassava abscission zone (AZ) cell separation under water-deficit stress. Microscopic observation indicated that AZ cell separation initiated ...

This study, in a broad sense, fills in the missing parts in previous efforts at pullback stripping mode design with a dipping coal seam. Three different spoiling procedures have been developed: the normal mode, where the coal seam is flat/nearly flat; the uphill mode, where the coal seam is dipping and the dragline spoils uphill; and the downhill mode, where the coal seam is again dipping but t...

Let R ∗ = R2k+1 \ {~0} (k ≥ 1) and π: R ∗ → S2k be the map sending ~r ∈ R ∗ to ~r |~r| ∈ S 2k . Denote by P → R ∗ the pullback by π of the canonical principal SO(2k)-bundle SO(2k + 1) → S2k . Let E] → R ∗ be the associated co-adjoint bundle and E] → T ∗R ∗ be the pullback bundle under projection map T ∗R ∗ → R ∗ . The canonical connection on SO(2k + 1) → S2k turns E] into a Poisson manifold. Th...

Fix a smooth very ample curve C on a K3 or abelian surface X . Let M denote the moduli space of pairs of the form (F, s), where F is a stable sheaf over X whose Hilbert polynomial coincides with that of the direct image, by the inclusion map of C in X , of a line bundle of degree d over C, and s is a nonzero section of F . Assume d to be sufficiently large such that F has a nonzero section. The...

Non-perturbative instanton corrections to the moduli space geometry of type IIA string theory compactified on a Calabi-Yau space are derived and found to contain order e−1/gs contributions, where gs is the string coupling. The computation reduces to a weighted sum of supersymmetric extremal maps of strings, membranes and fivebranes into the Calabi-Yau space, all three of which enter on equal fo...

Security problems in collaborative work between multiple agencies are less well understood than those in the business and defence worlds. We develop a perspective for policies and models that is task-based on a need-toknow basis. These policies are represented by two protocols, the first CTCP (Collaboration Task-based Creation Protocol) dealing with negotiation, decision and agreement between t...