Analogies between self-duality and stealth matter source

We consider the problem of a self-interacting scalar field nonminimally coupled to the three-dimensional BTZ metric such that its energy-momentum tensor evaluated on the BTZ metric vanishes. We prove that this system is equivalent to a self-dual system composed by a set of two first-order equations. The self-dual point is achieved by fixing one of the coupling constant of the potential in terms of the nonminimal coupling parameter. At the self-dual point and up to some boundary terms, the matter action evaluated on the BTZ metric is bounded below and above. These two bounds are saturated simultaneously yielding to a vanishing action for configurations satisfying the set of self-dual first-order equations.Comment: 6 pages. To be published in Jour. Phys.

Reduced Fungicide Inputs in Winter Wheat

End of Project ReportNine trials were conducted over three years at three sites to evaluate the efficacy of reduced rates of various fungicide products for their biological efficacy in controlling stem, foliar and ear diseases of winter wheat as well as their effects on yield and grain quality, and to compare the relative profitability of full and reduced rates of fungicides. The results show that the use of half rates can give an economic benefit over that of full rates in many situations. In circumstances where variety or seasonal factors resulted in low to moderate foliar disease pressure the use of half rates gave similar yields to that of full rates. Where foliar disease pressure was high, half rates generally gave lower yields than full rates but the amount of the reduction varied with the fungicide product used. The use of spray additives improved the yield response of the half rate treatments in most cases. Disease levels (septoria) were higher in treatments where half rates were used, compared with the corresponding full rates, but the used of spray additives improved the disease control in the half rate treatments. The timing of spray applications is critical when half rates of fungicides are being used. Reduced rate treatments need to be applied more frequently. In these trials reduced rate treatments were applied as a three-spray programme rather than the conventional two-spray programme.European Union Structural Funds (EAGGF)Cereals Levy Farmer Fund

Workshop on entrepreneurial finance: a summary

This Policy Discussion Paper summarizes papers that were presented at the Workshop on Entrepreneurial Finance, which was held March 12?13, 2009, at the Federal Reserve Bank of Cleveland. Researchers presented new empirical research that exploits data sets on entrepreneurial activity that are based on broad and representative data samples. Papers in the workshop focused primarily on analyses of the sources and structure of start-up finance, including the importance of bank lending, venture capital, angel investors, and owner equity.Small business - Finance

Monopole decay in the external electric field

The possibility of the magnetic monopole decay in the constant electric field is investigated and the exponential factor in the probability is obtained. Corrections due to Coulomb interaction are calculated. The relation between masses of particles for the process to exist is obtained.Comment: 13 pages, 8 figure

The role of HER1-HER4 and EGFRvIII in hormone-refractory prostate cancer

<b>Purpose</b>: The role of the type I receptor tyrosine kinase (HER) family in progression of prostate cancer is controversial. Breast cancer studies show that these receptors should be investigated as a family. The current study investigates expression of HER1-HER4 and EGFRvIII in matched hormone-sensitive and hormone-refractory prostate tumors. <b>Experimental Design</b>: Immunohistochemical analysis was used to investigate protein expression of HER1-HER4, EGFRvIII, and phosphorylated Akt (pAkt) in matched hormone-sensitive and hormone-refractory prostate tumors. <b>Results</b>: Surprisingly, high HER2 membrane expression in hormone-sensitive tumors was associated with an increased time to biochemical relapse (<i>P</i> = 0.0003), and this translated into longer overall survival (<i>P</i> = 0.0021). Consistent with other studies, HER4 membrane expression in hormone-sensitive tumors was associated with longer time to biochemical relapse (<i>P</i> = 0.042), and EGFRvIII membrane expression was associated with shorter time to biochemical relapse (<i>P</i> = 0.015). An increase in pAkt expression was associated with reduced survival (<i>P</i> = 0.0098). Multivariate analysis showed that HER2 was an independent positive predictive marker of time to relapse in hormone-sensitive prostate tumors (<i>P</i> = 0.014). In contrast, high HER2 expression in hormone-refractory tumors was associated with decreased time to death from biochemical relapse (<i>P</i> = 0.039), and EGFRvIII nuclear expression was associated with decreased time to death from biochemical relapse and decreased overall survival (<i>P</i> = 0.02 and <i>P</i> = 0.005). <b>Conclusion</b>: These results suggest that the HER family may have multiple roles in prostate cancer, and that expression of the proteins alone is insufficient to predict the biological response that they may elicit

Chern-Simons matrix model: coherent states and relation to Laughlin wavefunctions

Using a coherent state representation we derive many-body probability distributions and wavefunctions for the Chern-Simons matrix model proposed by Polychronakos and compare them to the Laughlin ones. We analyze two different coherent state representations, corresponding to different choices for electron coordinate bases. In both cases we find that the resulting probability distributions do not quite agree with the Laughlin ones. There is agreement on the long distance behavior, but the short distance behavior is different.Comment: 15 pages, LaTeX; one reference added, abstract and section 5 expanded, typos correcte

A Gauge-Gravity Relation in the One-loop Effective Action

We identify an unusual new gauge-gravity relation: the one-loop effective action for a massive spinor in 2n dimensional AdS space is expressed in terms of precisely the same function [a certain multiple gamma function] as the one-loop effective action for a massive charged scalar in 4n dimensions in a maximally symmetric background electromagnetic field [one for which the eigenvalues of F_{\mu\nu} are maximally degenerate, corresponding in 4 dimensions to a self-dual field, equivalently to a field of definite helicity], subject to the identification F^2 \Lambda, where \Lambda is the gravitational curvature. Since these effective actions generate the low energy limit of all one-loop multi-leg graviton or gauge amplitudes, this implies a nontrivial gauge-gravity relation at the non-perturbative level and at the amplitude level.Comment: 6 page

Renormalized Effective Actions in Radially Symmetric Backgrounds I: Partial Wave Cutoff Method

The computation of the one-loop effective action in a radially symmetric background can be reduced to a sum over partial-wave contributions, each of which is the logarithm of an appropriate one-dimensional radial determinant. While these individual radial determinants can be evaluated simply and efficiently using the Gel'fand-Yaglom method, the sum over all partial-wave contributions diverges. A renormalization procedure is needed to unambiguously define the finite renormalized effective action. Here we use a combination of the Schwinger proper-time method, and a resummed uniform DeWitt expansion. This provides a more elegant technique for extracting the large partial-wave contribution, compared to the higher order radial WKB approach which had been used in previous work. We illustrate the general method with a complete analysis of the scalar one-loop effective action in a class of radially separable SU(2) Yang-Mills background fields. We also show that this method can be applied to the case where the background gauge fields have asymptotic limits appropriate to uniform field strengths, such as for example in the Minkowski solution, which describes an instanton immersed in a constant background. Detailed numerical results will be presented in a sequel.Comment: 35 page

Functional Determinants in Quantum Field Theory

Functional determinants of differential operators play a prominent role in theoretical and mathematical physics, and in particular in quantum field theory. They are, however, difficult to compute in non-trivial cases. For one dimensional problems, a classical result of Gel'fand and Yaglom dramatically simplifies the problem so that the functional determinant can be computed without computing the spectrum of eigenvalues. Here I report recent progress in extending this approach to higher dimensions (i.e., functional determinants of partial differential operators), with applications in quantum field theory.Comment: Plenary talk at QTS5 (Quantum Theory and Symmetries); 16 pp, 2 fig