Triangular singularity and a possible ϕp\phi p resonance in the Λc+→π0ϕp\Lambda^+_c \to \pi^0 \phi p decay

We study the $\Lambda^+_c \to \pi^0 \phi p$ decay by considering a triangle singularity mechanism. In this mechanism, the $\Lambda^+_c$ decays into the $K^* \Sigma^*(1385)$, the $\Sigma^*(1385)$ decays into the $\pi^0 \Sigma$ (or $\Lambda$), and then the $K^* \Sigma$ (or $\Lambda$) interact to produce the $\phi p$ in the final state. This mechanism produces a peak structure around $2020$ MeV. In addition, the possibility that there is a hidden-strange pentaquark-like state is also considered by taking into account the final state interactions of $K^* \Lambda$, $K^* \Sigma$, and $\phi p$. We conclude that it is difficult to search for the hidden-strange analogue of the $P_c$ states in this decay. However, we do expect nontrivial behavior in the $\phi p$ invariant mass distribution. The predictions can be tested by experiments such as BESIII, LHCb and Belle-II.Comment: 7 pages, 3 figure

Characterization of a renoprotective AATF peptide in models of diabetic nephropathy

Inflammation and cell death play central roles in diabetic kidney complications. Identification of novel renoprotective molecules is essential for developing new therapies. We have identified an unconventional extrinsic renoprotective pathway mediated by a 12-amino acid peptide (SAP-12) derived from extracellularly secreted AATF (apoptosis antagonizing transcription factor) in blocking renal damage in models of diabetic nephropathy (DN). SAP-12 (secreted AATF peptide of 12 amino acids, SALKNSHKALKA) is conserved among human, mouse, and rat AATF proteins, and confers potent renoprotective properties at femtomolar concentrations with a broad effective range in renal tubular epithelial cells (RTECs) following exposure to high levels of glucose. We reported previously that AATF was a highly effective in protecting against renal damage and it rescues renal tubular epithelial cells from both apoptotic and necrotic death. The rationale for the current study was based on our recent observation that the renoprotective actions of AATF seemed to be accomplished in a highly unusual manner in diabetic kidneys. As a transcription factor, AATF often functions as an intracellular protein located in cytoplasmic and/or nuclear compartments. However, we have unexpectedly noted that a significant amount of intracellular AATF protein was secreted extracellularly by RTECs under diabetic conditions. Furthermore, secreted AATF (sAATF) functions, at least in part, as a specific ligand and antagonist of the cell surface receptor TLR4 (Toll-like receptor-4). Of importance, TLR4-mediated signaling has been shown to be critically involved in the inflammation and cell death in DN. A region corresponding to the amino acid sequence between AATF179 and AATF279 was responsible for interacting with TLR-4. Based on these observations, several small AATF core peptides derived from this region of AATF were synthesized and tested for their renoprotective properties and their ability to interact with TLR4. One of these peptides, SAP-12, was identified at the interface of AATF/TLR4 interaction. Surprisingly, SAP-12 had a much greater potency and broader effective dose range than the full length sAATF in protecting RTECs in models of diabetic nephropathy. The extrinsic pathway mediated by sAATF and SAP-12 provides strong support for the existence of non-classical secretory pathways where cytoplasmic and nuclear proteins can be secreted extracellularly without a classical N-terminal signal peptide. The region(s) in the extracellular ectodomain of TLR4 involved in interacting with SAP-12 and the potential therapeutic applications of SAP-12 in DN will be discussed. By studying the structure-activity relationships of SAP-12, it may also be possible to develop additional novel versatile peptides with even greater renoprotective capacity and specificity. This study is therefore highly innovative and significant. This work supported in part by an award from Harold Hamm Diabetes Center at the University of Oklahoma. # To whom correspondence should be addressed: Dept. of Physiology, The University of Oklahoma Health Sciences Center, Oklahoma City, OK 73104. Tel.: 405-271-2226; Fax: 405-271-3181; E-mail: [email protected]

Remote information concentration and multipartite entanglement in multilevel systems

Remote information concentration (RIC) in $d$-level systems (qudits) is studied. It is shown that the quantum information initially distributed in three spatially separated qudits can be remotely and deterministically concentrated to a single qudit via an entangled channel without performing any global operations. The entangled channel can be different types of genuine multipartite pure entangled states which are inequivalent under local operations and classical communication. The entangled channel can also be a mixed entangled state, even a bound entangled state which has a similar form to the Smolin state, but has different features from the Smolin state. A common feature of all these pure and mixed entangled states is found, i.e., they have $d^2$ common commuting stabilizers. The differences of qudit-RIC and qubit-RIC ($d=2$) are also analyzed.Comment: 10 pages, 3 figure

Relative Status Determination for Spacecraft Relative Motion Based on Dual Quaternion

For the two-satellite formation, the relative motion and attitude determination algorithm is a key component that affects the flight quality and mission efficiency. The relative status determination algorithm is proposed based on the Extended Kalman Filter (EKF) and the system state optimal estimate linearization. Aiming at the relative motion of the spacecraft formation navigation problem, the spacecraft relative kinematics and dynamics model are derived from the dual quaternion in the algorithm. Then taking advantage of EKF technique, combining with the dual quaternion integrated dynamic models, considering the navigation algorithm using the fusion measurement by the gyroscope and star sensors, the relative status determination algorithm is designed. At last the simulation is done to verify the feasibility of the algorithm. The simulation results show that the EKF algorithm has faster convergence speed and higher accuracy