687 research outputs found
D-Branes in the Background of NS Fivebranes
We study the dynamics of -branes in the near-horizon geometry of
fivebranes. This leads to a holographically dual description of the physics of
-branes ending on and/or intersecting -branes. We use it to verify some
properties of such -branes which were deduced indirectly in the past, and
discuss some instabilities of non-supersymmetric brane configurations. Our
construction also describes vacua of Little String Theory which are dual to
open plus closed string theory in asymptotically linear dilaton spacetimes.Comment: 44 pages, 16 figures, harvma
Ground-water Movement in the Upper Glacial Aquifer in the Manorville Area, Town of Brookhaven, Long Island, New York, in November 1983
Water levels in 52 wells near the Manorville scavenger-waste disposal facility in the Town of Brookhaven were measured in November 1983 to determine the direction and gradients of groundwater flow in the upper glacial aquifer. Groundwater moves south-southeastward (S22 degrees E) from the groundwater divide, about 6 miles north of the facility, to discharge points near East Moriches and beneath Moriches Bay. The hydraulic gradient beneath the disposal facility is 6.5 ft/mi (0.0012 foot/foot), and the rate of horizontal flow is 0.9 to 1.7 ft/day. Vertical movement of groundwater since closure of the disposal facility in 1982 is probably negligible because the vertical gradients are small and the upper glacial aquifer is anisotropic. During operation of the facility, however, groundwater mounding may have developed beneath the unlined settling basins, which could have induced downward movement of water in the upper glacial aquifer. (USGS
The Spectrum of Topologically Massive Quantum Electrodynamics
We discuss the possibility for the spectrum of topologically massive quantum
electrodynamics with spinor matter fields to contain unexpected and unusual
stable particle excitations for certain values of the topological photon mass.
The new field theoretical phenomena arising from this novel spectral structure
are briefly discussed.Comment: 14 pages, plain TeX; PUPT-1364, UBCTP 92-03
Mechanisms of matrix metalloproteinase-2 (mmp-2) transcriptional repression by progesterone in jar choriocarcinoma cells
<p>Abstract</p> <p>Background</p> <p>Although the MMP-2 promoter lacks a canonical progesterone response element (PRE), the hormone inhibits MMP-2 expression and is part of treatment protocols in gynecological invasive pathologies, including endometriosis and endometrial hyperplasia. This study aimed to explore the mechanism by which progesterone inhibits MMP-2 expression.</p> <p>Methods</p> <p>The effect of progesterone on MMP-2 expression in the JAR human choriocarcinoma cell line was analyzed by gelatin zymography. MMP-2 transcript expression was studied using Northern blot and semi-quantitative RT-PCR. Rat promoter deletion analysis, electrophoretic mobility shift and chromatin immuno-precipitation assays were performed in order to locate the DNA binding site and the transcription factors involved in MMP-2 regulation.</p> <p>Results</p> <p>Progesterone significantly decreased secretion of pro-MMP-2 and MMP-2 transcript expression level in a dose-dependent manner. Progesterone (1 microM) significantly decreased both human and rat MMP-2 promoter activity (80.1% +/- 0.3 and 81.3% +/- 0.23, respectively). Progesterone acts through the SP1 family transcription factors-binding site, located between -1433 and -1342 bp region from the transcriptional start site of the rat MMP-2 promoter, which are present in the orthologous human MMP-2 promoter. Progesterone receptor (PR), SP2, SP3 and SP4 proteins are constitutively bound to this consensus sequence.</p> <p>Conclusion</p> <p>Progesterone reducesPR and SP4 binding to the MMP-2 promoter, thereby suppressing transcription. Progesterone also promotes SP4 degradation. These novel mechanisms of MMP-2 regulation by progesterone provide the biological rationale for the use of progesterone in clinical settings associated with increased MMP-2 expression.</p
Information Spreading in Interacting String Field Theory
The commutator of string fields is considered in the context of light cone
string field theory. It is shown that the commutator is in general
non--vanishing outside the string light cone. This could have profound
implications for our understanding of the localization of information in
quantum gravity.Comment: 10 pages, 1 figure, harvmac and epsf, UCSBTH-94-07, SU-ITP-94-
The equity premium in a small open economy, and an application to Israel
In this paper we attempt to reproduce both the business cycle facts and the equity premium of the Israeli economy—an economy which is "typical" in the sense that investment is much more volatile than output (and consumption). We show that GHH preferences, which are quite common in RBC models of small open economies, are not suited for reproducing both the business cycle and the equity premium facts of a "typical" small open economy. We found that a way to progress is to "correct" the GHH preferences by adding some degree of wealth effect on labor supply. That is, by switching to the Jaimovich-Rebelo (2006) type of preferences. However, in this case we also need to add to the model some kind of limitations on labor supply (we used both real wage rigidity and habits in labor). Our main finding is that the use of Jaimovich-Rebelo preferences considerably improves the results relative to that achieved by GHH preferences. The reason for this is that the GHH preferences are characterized by a relatively high degree of substitutability between consumption and leisure and this moderates the volatility of the stochastic discount factor (SDF). By adding some degree of wealth effect we can achieve a significant increase in the volatility of the SDF, and hence an increase in the equity premium and in the volatility of investment. Following the relevant literature we used three shocks: to productivity, to government expenditure and to the world interest rate. Our analysis suggests that by adding one or more of two kinds of shocks: shocks to wealth and shocks to the real exchange rate – one can achieve a significant progress in reproducing both the business cycle facts and the equity premium
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