A study on the turbulent transport of an advective nature in the fluid plasma

Advective nature of the electrostatic turbulent flux of plasma energy is studied numerically in a nearly adiabatic state. Such a state is represented by the Hasegawa-Mima equation that is driven by a noise that may model the destabilization due to the phase mismatch of the plasma density and the electric potential. The noise is assumed to be Gaussian and not to be invariant under reflection along a direction $\hat s$. It is found that the flux density induced by such noise is anisotropic: While it is random along $\hat s$, it is not along the perpendicular direction ${\hat s}_\perp$ and the flux is not diffusive. The renormalized response may be approximated as advective with the velocity being proportional to $(k\rho_s)^2$ in the Fourier space $\vec k$

Protein kinase CK2 phosphorylates and activates p21-activated kinase 1

Activation of the p21-activated kinase 1 (PAK1) is achieved through a conformational change that converts an inactive PAK1 dimer to an active monomer. In this paper, we show that this change is necessary but not sufficient to activate PAK1 and that it is, rather, required for CK2-dependent PAK1S223 phosphorylation that converts a monomeric PAK1 into a catalytically active form. This phosphorylation appears to be essential for autophosphorylation at specific residues and overall activity of PAK1. A phosphomimetic mutation (S223E) bypasses the requirement for GTPases in PAK1 activation, whereas the constitutive activity of the PAK1 mutant (PAK1H83,86L), postulated to mimic GTPase-induced structural changes, is abolished by inhibition of S223 phosphorylation. Thus, S223 is likely accessible to CK2 upon conformational changes of PAK1 induced by GTPase-dependent and GTPase-independent stimuli, suggesting that S223 phosphorylation may play a key role in the final step of the PAK1 activation process. The physiological significance of this phosphorylation is reinforced by the observations that CK2 is responsible for epidermal growth factor–induced PAK1 activation and that inhibition of S223 phosphorylation abrogates PAK1-mediated malignant transformation of prostate epithelial cells. Taken together, these findings identify CK2 as an upstream activating kinase of PAK1, providing a novel mechanism for PAK1 activation

Realizing Physical Approximation of the Partial Transpose

The partial transpose by which a subsystem's quantum state is solely transposed is of unique importance in quantum information processing from both fundamental and practical point of view. In this work, we present a practical scheme to realize a physical approximation to the partial transpose using local measurements on individual quantum systems and classical communication. We then report its linear optical realization and show that the scheme works with no dependence on local basis of given quantum states. A proof-of-principle demonstration of entanglement detection using the physical approximation of the partial transpose is also reported.Comment: 5 pages with appendix, 3 figure

The Role of the Pleckstrin Homology Domain-Containing Protein CKIP-1 in Activation of p21-activated Kinase 1 (PAK1)

Upon growth factor stimulation, PAK1 is recruited to the plasma membrane and activated by a mechanism that requires its phosphorylation at S223 by the protein kinase CK2. However, the upstream signaling molecules that regulate this phosphorylation event are not clearly defined. Here, we demonstrate a major role of the CK2α-interacting protein CKIP-1 in activation of PAK1. CK2α, CKIP-1 and PAK1 are translocated to membrane ruffles in response to the epidermal growth factor (EGF), where CKIP-1 mediates the interaction between CK2α, and PAK1 in a PI3K-dependent manner. Consistently, we observe that PAK1 mediates phosphorylation and modulation of the activity of p41-Arc, one of its plasma membrane substrate, in a fashion that requires PI3K and CKIP-1. Moreover, CKIP-1 knockdown or PI3K inhibition suppresses PAK1-mediated cell migration and invasion, demonstrating the physiological significance of the PI3K-CKIP-1-CK2α-PAK1 signaling pathway. Taken together, these findings identify a novel mechanism for the activation of PAK1 at the plasma membrane, which is critical for cell migration and invasion

Experimental Implementation of the Universal Transpose Operation

The universal transpose of quantum states is an anti-unitary transformation that is not allowed in quantum theory. In this work, we investigate approximating the universal transpose of quantum states of two-level systems (qubits) using the method known as the structural physical approximation to positive maps. We also report its experimental implementation in linear optics. The scheme is optimal in that the maximal fidelity is attained and also practical as measurement and preparation of quantum states that are experimentally feasible within current technologies are solely applied.Comment: 4 pages, 4 figure

A DRAINAGE SYSTEM FOR MITIGATING MOISTURE DAMAGE TO BRIDGE DECK PAVEMENTS

This study presents the development of a new drainage system that can quickly drain water that has penetrated into bridge deck pavements. The new drainage system is expected to significantly reduce potholes that typically lead to premature failure of pavements. This system can be established by applying a thin drainage layer between the waterproofing layer and top wearing course. The most important factors for this system are to meet satisfactory performance of the waterproofing layer and to develop appropriate construction technique for the thin drainage layer. The drainage layer was formulated with porous asphalt mixtures designed for the max aggregate size of 10 mm, and was validated through various physical and mechanical laboratory tests to confirm its performance characteristics. For the waterproofing layer, methyl methacrylate (MMA) – type material was introduced, and a series of mechanical tests were performed to estimate the applicability of the MMA material for waterproofing. It was observed from the tests that the MMA material satisfied all specification requirements. In addition, to evaluate the field performance of the new drainage system, a field study was conducted on a real bridge. Field performance observations on both the waterproofing and pavement materials indicated that the new drainage system performs much better than traditional methods in draining water that has penetrated into pavement layers