Asymptotically Vanishing Cosmological Constant in the Multiverse

We study the problem of the cosmological constant in the context of the multiverse in Lorentzian spacetime, and show that the cosmological constant will vanish in the future. This sort of argument was started from Coleman in 1989, and he argued that the Euclidean wormholes make the multiverse partition a superposition of various values of the cosmological constant $\Lambda$, which has a sharp peak at $\Lambda=0$. However, the implication of the Euclidean analysis to our Lorentzian spacetime is unclear. With this motivation, we analyze the quantum state of the multiverse in Lorentzian spacetime by the WKB method, and calculate the density matrix of our universe by tracing out the other universes. Our result predicts vanishing cosmological constant. While Coleman obtained the enhancement at $\Lambda=0$ through the action itself, in our Lorentzian analysis the similar enhancement arises from the front factor of $e^{iS}$ in the universe wave function, which is in the next leading order in the WKB approximation.Comment: 17 pages, 7 figures; v2:minor correction

Dark Matter in B-L Extended MSSM Models

We analyze the dark matter problem in the context of supersymmetric U(1)_{B-L} model. In this model, the lightest neutalino can be the B-L gaugino widetilde {Z}_{B-L} or the extra Higgsinos widetilde{chi}_{1,2} dominated. We compute the thermal relic abundance of these particles and show that, unlike the LSP in MSSM, they can account for the observed relic abundance with no conflict with other phenomenological constraints. The prospects for their direct detection, if they are part of our galactic halo, are also discussed.Comment: 11 pages, 9 figures. Published versio

Rescue with an anti-inflammatory peptide of chickens infected H5N1 avian flu

Chickens suffering from avian flu caused by H5N1 influenza virus are destined to die within 2 days due to a systemic inflammatory response. Since HVJ infection (1,2) and influenza virus infection (3,4) cause infected cells to activate homologous serum complement, the systemic inflammatory response elicited could be attributed to the unlimited generation of C5a anaphylatoxin of the complement system, which is a causative peptide of serious inflammation. In monkeys inoculated with a lethal dose of LPS (4 mg/kg body weight), inhibition of C5a by an inhibitory peptide termed AcPepA (5) rescued these animals from serious septic shock which would have resulted in death within a day (6). Therefore, we tested whether AcPepA could also have a beneficial effect on chickens with bird flu. On another front, enhanced production of endothelin-1 (ET-1) and the activation of mast cells (MCs) have been implicated in granulocyte sequestration (7). An endothelin receptor derived antisense homology box peptide (8) designated ETR-P1/fl was shown to antagonize endothelin A receptor (ET-A receptor) (9) and reduce such inflammatory responses as endotoxin-shock (10) and hemorrhagic shock (11), thereby suppressing histamine release in the circulation (12). Thus, we also administered ETR-P1/fl to bird flu chickens expecting suppression of a systemic inflammatory response

Diquark Higgs at LHC

Existence of color sextet diquark Higgs fields with TeV masses will indicate a fundamentally different direction for unification than conventional grand unified theories. There is a class of partial unification models based on the gauge group $SU(2)_L\times SU(2)_R\times SU(4)_c$ that implement the seesaw mechanism for neutrino mass with seesaw scale around $10^{11}$ GeV, where indeed such light fields appear naturally despite the high gauge symmetry breaking scale. They couple only to up-type quarks in this model. We discuss phenomenological constraints on these fields and show that they could be detected at LHC via their decay to either $tt$ or single top + jet. We also find that existing Tevatron data gives a lower bound on its mass somewhere in the 400-500 GeV, for reasonable values of its coupling.Comment: 5 pages, 3 figure

Myocardial clearance of technetium-99m-teboroxime in reperfused injured canine myocardium

Background: Recent technical developments using solid-state technology have enabled rapid image acquisition with single photon emission computed tomography (SPECT) and have led to a renewed interest in technetium-99m-teboroxime (Tc-99m-teboroxime) as a myocardial imaging agent. Tc-99m-teboroxime has demonstrated high myocardial extraction, linear myocardial uptake relative to flow even at high flow rates, rapid uptake and clearance kinetics, and differential clearance in the setting of ischemia. However, the myocardial clearance kinetics of Tc-99m-teboroxime in a model of myocardial injury has not been previously reported. Thus, the purposes of this study were to use a canine model of ischemia-reperfusion to (1) compare Tc-99m-teboroxime clearance kinetics in normal and ischemic-reperfused myocardium and (2) assess the utility of Tc-99m-teboroxime clearance kinetics in determining the severity of injury following ischemia-reperfusion. Methods: Thirteen dogs underwent left circumflex coronary artery (LCx) occlusion for either 30 min (IR30, n = 6) or 120 min (IR120, n = 7), followed by reperfusion, and finally Tc-99m-teboroxime administration 120 min after reperfusion. Microsphere blood flows were determined at baseline, during occlusion, after reperfusion, and before euthanasia. Post-mortem, area at risk was determined using Evans blue dye, and viability was determined using triphenytetrazolium chloride (TTC) staining. The hearts were then subdivided into 24 pieces and Tc-99m activity was measured in a well counter. Results: TTC-determined infarct area as a percentage of total left ventricular myocardium was 1.1% ± 0.3% for the IR30 group and 7.5% ± 2.9% for the IR120 group (p < 0.05). During coronary occlusion, both the IR30 and IR120 groups demonstrated decreases in percent wall thickening in the ischemia-reperfusion zone (IRZ) as compared with the normal zone (NZ). In the IR30 group, percent wall thickening in the IRZ recovered during the reperfusion phase as compared with the NZ. In the IR120 group, percent wall thickening in the IRZ remained depressed during the reperfusion phase and through the end of the experiment as compared with the NZ. Final Tc-99m-teboroxime myocardial IRZ/NZ activity ratio was 0.94 ± 0.01 for the IR30 group, compared to 0.80 ± 0.01 for the IR120 group (p < 0.05). Conclusions: Tc-99m-teboroxime demonstrates moderate differential clearance in a model of severe injury with 120 min of ischemia-reperfusion, but only minimal differential clearance in a model of mild injury with 30 min of ischemia-reperfusion. Thus, Tc-99m-teboroxime clearance kinetics may be helpful in differentiating normal and minimally injured from severely injured myocardium

"A Comparison of the Japanese and U.S. Business Cycles"

The paper constructs a consistent set of quarterly Japanese data for the 1960-2002 sample period and compares properties of the Japanese and U.S. business cycles. We document some important differences in the adjustment of labor input between the two countries. In Japan most most of the adjustment is in hours per worker of males and females and also in employment of female. In the U.S. most of the adjustment is in employment of both males and females. We formulate, estimate and analyze a model that makes distinction between the intensive and extensive margin and allows for gender differences in labor supply. A weak empirical correlation between hours per worker and employment in Japanese data is a puzzle for our theory.

Rotating string in doubled geometry with generalized isometries

In this paper, we first construct a globally well-defined non-geometric background which contains several branes in type II string theory compactified on a 7-torus. One of these branes is called 5^2_2, which is a codimension-2 object and has a non-trivial monodromy given by a T-duality transformation. The geometry near the 5^2_2-brane is shown to approach the non-geometric background constructed in arXiv:1004.2521. We then construct the solution of a fundamental string rotating along a non-trivial cycle in the 5^2_2 background. Although the background is not axisymmetric in the usual sense, we show that it is actually axisymmetric as a doubled geometry by explicitly finding a generalized Killing vector. We perform a generalized coordinate transformation into a system where the generalized isometry is manifest, and show that the winding and momentum charges of the string solution is explicitly conserved in that system.Comment: 32 pages, 5 figures; v2: typos corrected, to appear in Physical Review D; v3 minor errors fixed, improvements and a reference added to section 4.

High Spectral and Spatial Resolution Observations of the PDR Emission in the NGC2023 Reflection Nebula with SOFIA and APEX

We have mapped the NGC 2023 reflection nebula in [CII] and CO(11--10) with the heterodyne receiver GREAT on SOFIA and obtained slightly smaller maps in 13CO(3--2), CO(3--2), CO(4--3), CO(6--5), and CO(7--6) with APEX in Chile. We use these data to probe the morphology, kinematics, and physical conditions of the C II region, which is ionized by FUV radiation from the B2 star HD37903. The [CII] emission traces an ellipsoidal shell-like region at a position angle of ~ -50 deg, and is surrounded by a hot molecular shell. In the southeast, where the C II region expands into a dense, clumpy molecular cloud ridge, we see narrow and strong line emission from high-J CO lines, which comes from a thin, hot molecular shell surrounding the [CII] emission. The [CII] lines are broader and show photo evaporating gas flowing into the C II region. Based on the strength of the [13CII] F=2--1 line, the [CII] line appears to be somewhat optically thick over most of the nebula with an optical depth of a few. We model the physical conditions of the surrounding molecular cloud and the PDR emission using both RADEX and simple PDR models. The temperature of the CO emitting PDR shell is ~ 90 -- 120 K, with densities of 10^5 -- 10^6 cm^-3, as deduced from RADEX modeling. Our PDR modeling indicates that the PDR layer where [CII] emission dominates has somewhat lower densities, 10^4 to a few times 10^5 cm^-3Comment: Accepted by A&

Derivation of mA≃MZm_A \simeq M_Z and tan⁡β>3\tan \beta > \sqrt 3 in the Minimal Supersymmetric Standard Model

In the minimal supersymmetric standard model, the Higgs sector has two unknown parameters, usually taken to be $\tan \beta \equiv v_2/v_1$ and $m_A$, the mass of its one physical pseudoscalar particle. By minimizing the minimum of the Higgs potential along a certain direction in parameter space, it is shown that $m_A = M_Z$ + radiative correction, and if one further plausible assumption is made, $\tan \beta > \sqrt 3$.Comment: 7 pages, University of California, Riverside Report No. UCRHEP-T105 (Feb 1993). [Discussion of radiative correction is now included.

Natural Realizations of Seesaw in Mini-Warped Minimal SO(10)

The minimal SUSY SO(10) GUT models with {\bf 10}, {\bf 126} and {\bf 210} Higgs and only renormalizable couplings has been shown to provide a simple way to understand the neutrino mixings as well as the ratio $\Delta m^2_\odot/\Delta m^2_A$ in terms of quark mixing parameter $\theta_{Cabibbo}$, provided neutrino masses are described by type II seesaw formula. However, in this minimal picture, it is impossible to realize type II dominance with renormalizable couplings in 4-dimensions. We show that this problem can be cured by embedding this model into a warped 5-dimensional space time with warping between the Planck and the GUT scale, where both type II as well as mixed seesaw formulae can be realized in a natural manner without expanding the Higgs sector. These models also avoid the possible problem of threshold effects associated with large Higgs representations since the theory above the GUT scale is now strongly coupled.Comment: 20 pages and one figur