Testing Gauge-Gravitino Coupling in Gauge-Mediated Supersymmetry Breaking Through Single Photon Events

We show that the process $e^+e^- \to \gamma+$ missing energy, arising from the pair production of neutralinos, can probe the \gamma-\tilde\gamma- \gravitino as well as the Z-\tilde Z-\gravitino couplings in Gauge Mediated Supersymmetry Breaking models. This enables one to study the mutual relationship of the Goldstino couplings of the different gauginos, a feature whose testability has not been emphasized so far. The Standard Model backgrounds get suppresed with the use of a right polarized electron beam. The energy and angular distribution of the emitted photon can distinguish such models from the minimal supersymmetric theory and its variants.Comment: Revised version to be published in Physics Letters B. Some minor changes were mad

Fibroblast-derived HGF drives acinar lung cancer cell polarization through integrin-dependent RhoA-ROCK1 inhibition

The formation of lumens in epithelial tissues requires apical-basal polarization of cells, and the co-ordination of this individual polarity collectively around a contiguous lumen. Signals from the Extracellular Matrix (ECM) instruct epithelia as to the orientation of where basal, and thus consequently apical, surfaces should be formed. We report that this pathway is normally absent in Calu-3 human lung adenocarcinoma cells in 3-Dimensional culture, but that paracrine signals from MRC5 lung fibroblasts can induce correct orientation of polarity and acinar morphogenesis. We identify HGF, acting through the c-Met receptor, as the key polarity-inducing morphogen, which acts to activate β1-integrin-dependent adhesion. HGF and ECM-derived integrin signals co-operate via a c-Src-dependent inhibition of the RhoA-ROCK1 signalling pathway via p190A RhoGAP. This occurred via controlling localization of these signalling pathways to the ECM-abutting surface of cells in 3-Dimensional culture. Thus, stromal derived signals can influence morphogenesis in epithelial cells by controlling activation and localization of cell polarity pathways

Relativistic Hamiltonian for Neutral Atom of Spin-1/2 Nucleus in Homogeneous Magnetic Field

A relativistic formalism to construct the Hamiltonian for a general N-electron neutral atom with a spin-1/2 nucleus and placed in a homogeneous magnetic field [J. Chem. Phys. 123 064101 (2005)] is discussed here. Projected Coulomb and Breit interactions are taken to describe the inter-particle interaction through second order in fine structure constant. The center of mass motion is separated from the movement of the neutral (N+1) fermion system. Using a series of suitable unitary transformations, the Hamiltonian can be brought into a separable form. The correct atomic Hamiltonian in the non-relativistic limit is also discussed. The treatment can be extended to the case of a molecule containing atoms of only spin-1/2 nuclei

Death in the Hills: Mithun Calves, Arunachal Pradesh's hill symbols, are threatened by an epidemic of foot-and-mouth disease.

The two-month-old mithun calf lay by the side of the road. Its lifeless glassy eyes stared into nothingness, but its feet twitched occasionally in spasms before death finally came. The young mother stood unsurely beside the calf, licking it at intervals, Scenes like this played out virtually every day in the last few months, reminding us of the epidemic that had besieged this remote corner of Arunachal Pradesh. The killer was a virus (Aphthae epizooticae) belonging to the picornaviridae family, causing the dreaded foot and mouth disease

Wilson flow with naive staggered quarks

Scale setting for QCD with two flavours of staggered quarks is examined using Wilson flow over a factor of four change in both the lattice spacing and the pion mass. The statistics needed to keep the errors in the flow scale fixed is found to increase approximately as the inverse square of the lattice spacing. Tree level improvement of the scales t_0 and w_0 is found to be useful in most of the range of lattice spacings we explore. The scale uncertainty due to remaining lattice spacing effects is found to be about 3%. The ratio w_0/\sqrt{t_0} is N_f dependent and we find its continuum limit to be 1.106 \pm 0.007 (stat) \pm 0.005 (syst) for m_\pi w_0 \simeq 0.3