Protection Against Cardiac Injury by Small Ca\u3csup\u3e2 +\u3c/sup\u3e-Sensitive K\u3csup\u3e+\u3c/sup\u3e Channels Identified in Guinea Pig Cardiac Inner Mitochondrial Membrane

We tested if small conductance, Ca2 +‐sensitive K+ channels (SKCa) precondition hearts against ischemia reperfusion (IR) injury by improving mitochondrial (m) bioenergetics, if O2‐derived free radicals are required to initiate protection via SKCa channels, and, importantly, if SKCa channels are present in cardiac cell inner mitochondrial membrane (IMM). NADH and FAD, superoxide (O2−), and m[Ca2 +] were measured in guinea pig isolated hearts by fluorescence spectrophotometry. SKCa and IKCa channel opener DCEBIO (DCEB) was given for 10 min and ended 20 min before IR. Either TBAP, a dismutator of O2−, NS8593, an antagonist of SKCa isoforms, or other KCa and KATP channel antagonists, were given before DCEB and before ischemia. DCEB treatment resulted in a 2-fold increase in LV pressure on reperfusion and a 2.5 fold decrease in infarct size vs. non-treated hearts associated with reduced O2− and m[Ca2 +], and more normalized NADH and FAD during IR. Only NS8593 and TBAP antagonized protection by DCEB. Localization of SKCa channels to mitochondria and IMM was evidenced by a) identification of purified mSKCa protein by Western blotting, immuno-histochemical staining, confocal microscopy, and immuno-gold electron microscopy, b) 2-D gel electrophoresis and mass spectroscopy of IMM protein, c) [Ca2 +]‐dependence of mSKCa channels in planar lipid bilayers, and d) matrix K+ influx induced by DCEB and blocked by SKCa antagonist UCL1684. This study shows that 1) SKCa channels are located and functional in IMM, 2) mSKCa channel opening by DCEB leads to protection that is O2−dependent, and 3) protection by DCEB is evident beginning during ischemia

Cultural orientation of self-bias in perceptual matching

This work was supported by grants from the Economic and Social Research Council (ES/K013424/1), the National Natural Science Foundation of China (31371017), and the Research Grants Council of Hong Kong (HKU758412H)Peer reviewedPublisher PD

Finite Grand Unified Theories and the Quark Mixing Matrix

In N = 1 super Yang-Mills theories, under certain conditions satisfied by the spectrum and the Yukawa couplings, the beta functions will vanish to all orders in perturbation theory. We address the generation of realistic quark mixing angles and masses in such finite Grand Unified Theories. Working in the context of finite SUSY SU(5), we present several examples with realistic quark mixing matrices. Non-Abelian discrete symmetries are found to be important in satisfying the conditions for finiteness. Our realistic examples are based on permutation symmetries and the tetrahedral symmetry $A_4$. These examples enable us to address questions such as the decay rate of the proton in finite GUTs.Comment: 16 pages, LaTeX, typos correcte

Pair production of neutralinos via gluon-gluon collisions

The production of a neutralino pair via gluon-gluon fusion is studied in the minimal supersymmetric model(MSSM) at proton-proton colliders. The numerical analysis of their production rates are carried out in the mSUGRA scenario. The results show that this cross section may reach about 80 femto barn for $\tilde{\chi}^{0}_{1}\tilde{\chi}^{0}_{2}$ pair production and 23 femto barn for $\tilde{\chi}^{0}_{2}\tilde{\chi}^{0}_{2}$ pair production with suitable input parameters at the future LHC collider. It shows that this loop mediated process can be competitive with the quark-antiquark annihilation process at the LHC.Comment: LaTex file, l4 pages, 5 EPS figure

Anomalous behavior in an effective model of graphene with Coulomb interactions

We analyze by exact Renormalization Group (RG) methods the infrared properties of an effective model of graphene, in which two-dimensional massless Dirac fermions propagating with a velocity smaller than the speed of light interact with a three-dimensional quantum electromagnetic field. The fermionic correlation functions are written as series in the running coupling constants, with finite coefficients that admit explicit bounds at all orders. The implementation of Ward Identities in the RG scheme implies that the effective charges tend to a line of fixed points. At small momenta, the quasi-particle weight tends to zero and the effective Fermi velocity tends to a finite value. These limits are approached with a power law behavior characterized by non-universal critical exponents.Comment: 42 pages, 7 figures; minor corrections, one appendix added (Appendix A). To appear in Ann. Henri Poincar

Tight bounds on the competitive ratio on accomodating sequences for the seat reservation problem

The unit price seat reservation problem is investigated. The seat reservation problem is the problem of assigning seat numbers on-line to requests for reservations in a train traveling through $k$ stations. We are considering the version where all tickets have the same price and where requests are treated fairly, i.e., a request which can be fulfilled must be granted. For fair deterministic algorithms, we provide an asymptotically matching upper bound to the existing lower bound which states that all fair algorithms for this problem are frac{1{2-competitive on accommodating sequences, when there are at least three seats. Additionally, we give an asymptotic upper bound of frac{7{9 for fair randomized algorithms against oblivious adversaries. We also examine concrete on-line algorithms, First-Fit and Random, for the special case of two seats. Tight analyses of their performance are given

Donor Centers and Absorption Spectra in Quantum Dots

We have studied the electronic properties and optical absorption spectra of three different cases of donor centers, D^{0}, D^{-} and D^{2-}, which are subjected to a perpendicular magnetic field, using the exact diagonalization method. The energies of the lowest lying states are obtained as function of the applied magnetic field strength B and the distance zeta between the positive ion and the confinement xy-plane. Our calculations indicate that the positive ion induces transitions in the ground-state, which can be observed clearly in the absorption spectra, but as zeta goes to 0 the strength of the applied magnetic field needed for a transition to occur tends to infinity.Comment: 5 pages, 4 figures, REVTeX 4, gzipped tar fil

A study on simulation analysis for laser-welded I-core sandwich plate with different material properties and T-joint weld characteristic

Stiffness and strength of sandwich plate vary depending on similar (SI) or dissimilar (DSI) material element (faceplate or core) and laser weld geometry. The issues of I-core sandwich plate characteristics are essential to attain practical sandwich plate application. Hence, research on different material properties and T-joint weld characteristics of I-core sandwich steel plate presents a positive understanding of various character factors that affect sandwich plate bending performance. In this paper, the I-core sandwich steel plate characteristic was investigated using finite element analysis (FEA). The 3-point bending with a fine meshing, interaction of elements, and load applied was kept constant. The partition size at the laser weld geometry is smaller, and the partition size continuously grows when further away from the weld geometry. The result shows that a combination of weak and strong material on either element will reduce I-core sandwich's stiffness and strength unless strong material is assigned at the faceplate and core. Moreover, there is a significant change when rootgap is present. This influencing the centric and eccentric of the weld. The weld width produces a perfect bending as wholesome T-joint, yet to achieve such traits is impossible in reality but possible when the weld length is closer to the length of the core. The exploration of these characteristics in response to I-core sandwich steel plate holds a good response in engaging for the multiple variables that affect the plate's stiffness and strength

Pairing symmetry of superconducting graphene

The possibility of intrinsic superconductivity in alkali-coated graphene monolayers has been recently suggested theoretically. Here, we derive the possible pairing symmetries of a carbon honeycomb lattice and discuss their phase diagram. We also evaluate the superconducting local density of states (LDOS) around an isolated impurity. This is directly related to scanning tunneling microscopy experiments, and may evidence the occurrence of unconventional superconductivity in graphene.Comment: Eur. Phys. J. B, to appea