Normal ordering and boundary conditions in open bosonic strings

Boundary conditions play a non trivial role in string theory. For instance the rich structure of D-branes is generated by choosing appropriate combinations of Dirichlet and Neumann boundary conditions. Furthermore, when an antisymmetric background is present at the string end-points (corresponding to mixed boundary conditions) space time becomes non-commutative there. We show here how to build up normal ordered products for bosonic string position operators that satisfy both equations of motion and open string boundary conditions at quantum level. We also calculate the equal time commutator of these normal ordered products in the presence of antisymmetric tensor background.Comment: 7 pages no figures, References adde

Tuberculosis of the Kidney: A Clinical Study with Special Reference to Renal Function Before and After Nephrectomy

The clinical study, which is the subject of this investigation was commenced in 1953. It includes complete records of twenty two patients suffering from renal tuberculosis who have been investigated clinically, surgically and biochemically. The patients were selected only in so far as they had nephrectomy carried out. The specimens obtained were examined bacteriologically and histologically. It has been shown that the TmPAH results can be used as an accurate index of the quantitative severity of the lesion present and also as a-measurement of the prognosis to be expected. The derived fractions have provided information which suggests that the pathological process of renal tuberculosis produced damage of the smaller arteries, thus worsening the general effect of the infection which had occurred in the kidney. This has been confirmed by examination of the histological specimens available. Hypertension as a complication of unilateral renal tuberculosis has been discovered as a collateral finding and an introductory comment has been made on this feature. Finally, a brief review is given of the modern method of treatment of the condition, with a suggestion that mild cases of renal tuberculosis can now be confidently dealt with by anti-tuberculous chemotherapy alone

Synergistic action of nikkomycins X and Z with papulacandin B on whole cells and regenerating protoplasts of Candida albicans

Combinations of nikkomycin X (NX) or nikkomycin Z (NZ), known inhibitors of chitin synthesis in fungi, together with papulacandin B (PB), an inhibitor of beta-glucan synthesis, were tested for synergistic activity against four isolates of Candida albicans by using the broth microdilution checkerboard technique and a method to assess the regeneration of cell wall material in protoplasts. The construction of isobolograms from the data generated by the checkerboard determinations revealed a synergistic effect for the two classes of compounds against all strains. The combination of NX and PB was more effective than the combination of NZ and PB, perhaps reflecting the lower Ki value of NX. While the presence of NX and NZ reduced chitin synthesis, as determined by staining with calcofluor white and assaying with a microfluorimeter, cells treated with PB demonstrated an increased synthesis of chitin. Protoplast regeneration experiments using similar concentrations of the two classes of compounds resulted in comparable findings. The combination of NX and PB resulted in a greater inhibition of chitin synthesis than did equivalent combinations of NZ and PB. These data suggest that combinations of agents active against cell wall synthesis in fungi may prove more useful as chemotherapeutic agents than such compounds used singly

High pressure polymorphism of ?-TaON

The high pressure behavior of TaON was studied using a combination of Raman scattering, synchrotron X-ray diffraction, and X-ray absorption spectroscopy in diamond anvil cells to 70 GPa at ambient temperature. A Birch–Murnaghan equation of state fit for baddeleyite structured ?-TaON indicates a high bulk modulus value Ko = 328 ± 4 GPa with K?o = 4.3. EXAFS analysis of the high pressure XAS data provides additional information on changes in the Ta–(O,N) and Ta–Ta distances. Changes in the X-ray diffraction patterns and Raman spectra indicate onset of a pressure induced phase transition near 33 GPa. Our analysis indicates that the new phase has an orthorhombic cotunnite-type structure but that the phase transition may not be complete even by 70 GPa. Similar sluggish transformation kinetics are observed for the isostructural ZrO2 phase. Analysis of compressibility data for the new cotunnite-type TaON phase indicate a very high bulk modulus Ko 370 GPa, close to the theoretically predicted value.<br/

Glueball Regge trajectories from gauge/string duality and the Pomeron

The spectrum of light baryons and mesons has been reproduced recently by Brodsky and Teramond from a holographic dual to QCD inspired in the AdS/CFT correspondence. They associate fluctuations about the AdS geometry with four dimensional angular momenta of the dual QCD states. We use a similar approach to estimate masses of glueball states with different spins and their excitations. We consider Dirichlet and Neumann boundary conditions and find approximate linear Regge trajectories for these glueballs. In particular the Neumann case is consistent with the Pomeron trajectory.Comment: In this revised version we made some additional remarks on the text. We also included 2 more references. The glueball spectrum and Regge trajectories are unchanged. 10 pages, 2 eps figure

Capital account regulations and the trading system: a compatibility review

This repository item contains a single issue of the Pardee Center Task Force Reports, a publication series that began publishing in 2009 by the Boston University Frederick S. Pardee Center for the Study of the Longer-Range Future. Spanish version produced by the Center for the Study of State and Society, Buenos Aires. Portuguese version coordinated by Daniela Magalhaes Prates, a contributing author of the report, in collaboration with Ana Trivellato (translator), and Maria Inês Amorozo (graphic designer).This report is the product of the Pardee Center Task Force on Regulating Capital Flows for Long-Run Development and builds on the Task Force´s first report published in March 2012. The Pardee Center Task Force was convened initially in September 2011 as consensus was emerging that the global financial crisis has re-confirmed the need to regulate cross-border finance. The March 2012 report argues that international financial institutions – and in particular the International Monetary Fund – need to support measures that would allow capital account regulations (CARs) to become a standard and effective part of the macroeconomic policy toolkit. Yet some policymakers and academics expressed concern that many nations — and especially developing countries — may not have the flexibility to adequately deploy such regulations because of trade and investment treaties they are party to. In June 2012, the Pardee Center, with the Center for the Study of State and Society (CEDES) in Argentina and Global Development and Environment Institute (GDAE) at Tufts University, convened a second Task Force workshop in Buenos Aires specifically to review agreements at the WTO and various Free Trade Agreements (FTAs) and Bilateral Investment Treaties (BITs) for the extent to which the trading regime is compatible with the ability to deploy effective capital account regulations. This report presents the findings of that review, and highlights a number of potential incompatibilities found between the trade and investment treaties and the ability to deploy CARs. It also highlights an alarming lack of policy space to use CARs under a variety of FTAs and BITs—especially those involving the United States. Like the first report, it was written by an international group of experts whose goal is to help inform discussions and decisions by policymakers at the IMF and elsewhere that will have implications for the economic health and development trajectories for countries around the world

Immunohistochemical Expression of Growth Factors in the Follicular Wall of Normal and Cystic Ovaries of Sows

Contents: The expression of growth factors was evaluated immunohistochemically in normal and cystic ovaries of sows. The immunohistochemically stained area (IHCSA) was quantified by image analysis to analyse the expression of these proteins in the follicular wall of secondary, tertiary and cystic follicles. IGF-I immunoreactivity was strong in the granulosa cell layer (GC), moderate in the theca interna (TI) and mild in the theca externa (TE) of the normal follicles. There was severe reduction of the labelling to IGF-I in the GC of the follicular and luteinized cysts. In the normal follicles, the reactivity for IGF-II was very similar to pattern noted in IGF-I. There was reduction of the IHCSAs in the GC of the follicular and luteinized cysts, but the decrease was not significant. The staining of the IGF-II in the TI and TE of the cysts was increased, in comparison with normal follicles. The IHCSAs for VEGF were higher in the GC and TE of the normal follicles in contrast to TI, but this difference was noted only in the tertiary follicle. The VEGF reactivity increased in the GC of the cysts, in relation to normal follicles. The results of the current study show that the formation of ovarian cysts in sows is associated with alterations in the immunohistochemical expression of some growth factors.Fil: Sant'Ana, F. J. F.. Universidade do Brasília; BrasilFil: Reis Junior, J. L.. Universidade do Brasília; BrasilFil: Blume, G. R.. Universidade do Brasília; BrasilFil: Gimeno, Eduardo Juan. Universidad Nacional de La Plata. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rey, Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; ArgentinaFil: Ortega, Hugo Hector. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Ciencias Veterinarias del Litoral. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias. Instituto de Ciencias Veterinarias del Litoral; Argentin

A Topological Study of Contextuality and Modality in Quantum Mechanics

Kochen-Specker theorem rules out the non-contextual assignment of values to physical magnitudes. Here we enrich the usual orthomodular structure of quantum mechanical propositions with modal operators. This enlargement allows to refer consistently to actual and possible properties of the system. By means of a topological argument, more precisely in terms of the existence of sections of sheaves, we give an extended version of Kochen-Specker theorem over this new structure. This allows us to prove that contextuality remains a central feature even in the enriched propositional system.Comment: 10 pages, no figures, submitted to I. J. Th. Phy