Drinfel'd Twisted Superconformal Algebra and Structure of Unbroken Symmetries

We investigate deformed superconformal symmetries on non(anti)commutative (super)spaces from the point of view of the Drinfel'd twisted symmetries. We classify all possible twist elements derived from an abelian subsector of the superconformal algebra. The symmetry breaking caused by the non(anti)commutativity of the (super)spaces is naturally interpreted as the modification of their coproduct emerging from the corresponding twist element. The remaining unbroken symmetries are determined by the commutative properties of those symmetry generators possessing the twist element. We also comment on non-canonically deformed non(anti)commutative superspaces, particularly those derived from the superconformal twist element (\mathcal{F}_{\mathrm{SS}}).Comment: 13 pages, LaTeX; typos of published version and references are correcte

Time-dependent and Non-BPS Solutions in N=6 Superconformal Chern-Simons Theory

We study a class of classical solutions of three-dimensional N=6 superconformal Chern-Simons theory coupled with U(N) \times U(N) bi-fundamental matter fields. Especially, time evolutions of fuzzy spheres are discussed for both massless and massive cases. For the massive case, there are a variety of solutions having different behaviors according to the value of the mass. In addition to the time-dependent solutions, we analyze non-BPS static solutions which represent parallel M5/M5 or M5/anti-M5-branes suspended by multiple M2-branes. These solutions are similar to the fundamental strings connecting two parallel (anti) Dp-branes in perturbative string theory. A moving M5-brane and domain wall solutions with constant velocity that are obtained by the Lorentz boost of the known BPS solutions are briefly addressed.Comment: 27 pages, 9 figures, published version in JHE

Non-local Wess-Zumino Model on Nilpotent Noncommutative Superspace

We investigate the theory of the bosonic-fermionic noncommutativity, $[x^{\mu},\theta^{\alpha}] = i \lambda^{\mu \alpha}$, and the Wess-Zumino model deformed by the noncommutativity. Such noncommutativity links well-known space-time noncommutativity to superspace non-anticommutativity. The deformation has the nilpotency. We can explicitly evaluate noncommutative effect in terms of new interactions between component fields. The interaction terms that have Grassmann couplings are induced. The noncommutativity does completely break full $\mathcal{N}=1$ supersymmetry to $\mathcal{N} = 0$ theory in Minkowski signature. Similar to the space-time noncommutativity, this theory has higher derivative terms and becomes non-local theory. However this non-locality is milder than the space-time noncommutative field theory. Due to the nilpotent feature of the coupling constants, we find that there are only finite number of Feynman diagrams that give noncommutative corrections at each loop order.Comment: Latex, 16 pages, 2 figures, typos corrected, some references and comments on auxiliary field added, a figure replaced, English refine

Controllable Immunosuppression in Pigs as a Basis for Preclinical Studies on Human Cell Therapy

Along with a growing interest in regenerative medicine, pigs are becoming a popular model for preclinical studies on human cell therapy. Due to pharmaceutical species difference and inability to self-medicate, specific modification and care are necessary in immunosuppressive regimen for pigs. Here, we summarize recent literature on immunosuppression in pigs for experimental transplantation. Based on literature and our own experiences, a practical protocol has been proposed in this report. In early studies of allogeneic organ transplantation, recipient pigs were administered cyclosporine or tacrolimus, and mycophenolate mofetil at slightly higher dose than that in human cases, because of relatively poor effectiveness of the drugs in pigs. Steroids may be effective but sometimes can cause debilitating side effects. Cell transplantation studies follow the basic protocol, but it remains to be clarified whether the smaller graft mass, even if it is xenogeneic, requires the same scale of immunosuppression as organ transplantation. To obtain reliable results, the use of gastrostomy tube and blood trough level monitoring are highly recommended. Nonpharmaceutical immunosuppression such as thymic intervention and the use of severe combined immunodeficient pigs have also been discussed