Moduli Space Dimensions of Multi-Pronged Strings

The numbers of bosonic and fermionic zero modes of multi-pronged strings are counted in ${\cal N}=4$ super-Yang-Mills theory and compared with those of the IIB string theory. We obtain a nice agreement for the fermionic zero modes, while our result for the bosonic zero modes differs from that obtained in the IIB string theory. The possible origin of the discrepancy is discussedComment: 15 pages, 2 figure

Mesenchymal stem cell-based therapy for ischemic stroke

Ischemic stroke represents a major, worldwide health burden with increasing incidence. Patients affected by ischemic strokes currently have few clinically approved treatment options available. Most currently approved treatments for ischemic stroke have narrow therapeutic windows, severely limiting the number of patients able to be treated. Mesenchymal stem cells represent a promising novel treatment for ischemic stroke. Numerous studies have demonstrated that mesenchymal stem cells functionally improve outcomes in rodent models of ischemic stroke. Recent studies have also shown that exosomes secreted by mesenchymal stem cells mediate much of this effect. In the present review, we summarize the current literature on the use of mesenchymal stem cells to treat ischemic stroke. Further studies investigating the mechanisms underlying mesenchymal stem cells tissue healing effects are warranted and would be of benefit to the field

Response of the North Atlantic thermohaline circulation and ventilation to increasing carbon dioxide in CCSM3

Author Posting. © American Meteorological Society 2006. This article is posted here by permission of American Meteorological Society for personal use, not for redistribution. The definitive version was published in Journal of Climate 19 (2006): 2382–2397, doi:10.1175/JCLI3757.1.The response of the North Atlantic thermohaline circulation to idealized climate forcing of 1% per year compound increase in CO2 is examined in three configurations of the Community Climate System Model version 3 that differ in their component model resolutions. The strength of the Atlantic overturning circulation declines at a rate of 22%–26% of the corresponding control experiment maximum overturning per century in response to the increase in CO2. The mean meridional overturning and its variability on decadal time scales in the control experiments, the rate of decrease in the transient forcing experiments, and the rate of recovery in periods of CO2 stabilization all increase with increasing component model resolution. By examining the changes in ocean surface forcing with increasing CO2 in the framework of the water-mass transformation function, we show that the decline in the overturning is driven by decreasing density of the subpolar North Atlantic due to increasing surface heat fluxes. While there is an intensification of the hydrologic cycle in response to increasing CO2, the net effect of changes in surface freshwater fluxes on those density classes that are involved in deep-water formation is to increase their density; that is, changes in surface freshwater fluxes act to maintain a stronger overturning circulation. The differences in the control experiment overturning strength and the response to increasing CO2 are well predicted by the corresponding differences in the water-mass transformation rate. Reduction of meridional heat transport and enhancement of meridional salt transport from mid- to high latitudes with increasing CO2 also act to strengthen the overturning circulation. Analysis of the trends in an ideal age tracer provides a direct measure of changes in ocean ventilation time scale in response to increasing CO2. In the subpolar North Atlantic south of the Greenland–Scotland ridge system, there is a significant increase in subsurface ages as open-ocean deep convection is diminished and ventilation switches to a predominance of overflow waters. In middle and low latitudes there is a decrease in age within and just below the thermocline in response to a decrease in the upwelling of old deep waters. However, when considering ventilation within isopycnal layers, age increases for layers in and below the thermocline due to the deepening of isopycnals in response to global warming

A Dual Geometry of the Hadron in Dense Matter

We identify the dual geometry of the hadron phase of dense nuclear matter and investigate the confinement/deconfinement phase transition. We suggest that the low temperature phase of the RN black hole with the full backreaction of the bulk gauge field is described by the zero mass limit of the RN black hole with hard wall. We calculated the density dependence of critical temperature and found that the phase diagram closes. We also study the density dependence of the rho meson mass.Comment: 16 pages, 4 figures, typos corrected, references adde

Physical Response Functions of Strongly Coupled Massive Quantum Liquids

We study physical properties of strongly coupled massive quantum liquids from their spectral functions using the AdS/CFT correspondence. The generic model that we consider is dense, heavy fundamental matter coupled to SU(N_c) super Yang-Mills theory at finite temperature above the deconfinement phase transition but below the scale set by the baryon number density. In this setup, we study the current-current correlators of the baryon number density using new techniques that employ a scaling behavior in the dual geometry. Our results, the AC conductivity, the quasi-particle spectrum and the Drude-limit parameters like the relaxation time are simple temperature-independent expressions that depend only on the mass-squared to density ratio and display a crossover between a baryon- and meson-dominated regime. We concentrated on the (2+1)-dimensional defect case, but in principle our results can also be generalized straightforwardly to other cases.Comment: 21 pages, 10 figures, extra paragraph and figure are added in response to referee's comment

Couplings of the Rho Meson in a Holographic dual of QCD with Regge Trajectories

The couplings $g_{\rho HH}$ of the $\rho$ meson with any hadron H are calculated in a holographic dual of QCD where the Regge trajectories for mesons are manifest. The resulting couplings grow linearly with the exciting number of H, thus are far from universal. A simple argument has been given for this behavior based on quasi-classical picture of excited hadrons. It seems that in holographic duals with exact Regge trajectories the $g_{\rho HH}$ universality should be violated. The $\rho$-dominance for the electromagnetic form factors of H are also strongly violated, except for the lowest state, the pion. Quite unexpected, the form factor of the pion is completely saturated by the contribution of the $\rho$. The asymptotic behavior of the form factors are also calculated, and are found to be perfectly accordant with the prediction of conformal symmetry and pertubative QCD.Comment: 9 page

Bis[methyl 3-(propyl­amino)­but-2-eno­ato]zinc

The title compound, [Zn(C8H14NO2)2], represents a zinc complex with the Zn2+ cation coordinated by two O and two N atoms in a distorted tetrahedral geometry