Observables and Correlation Functions in OSp Invariant String Field Theory

We define BRST invariant observables in the OSp invariant closed string field theory for bosonic strings. We evaluate correlation functions of these observables and show that the S-matrix elements derived from them coincide with those of the light-cone gauge string field theory.Comment: 23 page

D-branes and Closed String Field Theory

We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter. One can show that these solitonic states describe D-branes and ghost D-branes, by calculating the scattering amplitudes.Comment: 8 pages, 2 figures, based on an invited talk presented at the international workshop "Progress of String Theory and Quantum Field Theory" (Osaka City University, December 7-10, 2007), to be published in the proceeding

Standardization of metaiodobenzylguanidine heartto mediastinum ratio using a calibration phantom: Effects of correction on normal databases and a multicentre study

Purpose: This study was performed to demonstrate that the results obtained with a calibration phantom could be used as a tool for standardizing measurement of heart to mediastinum (H/M) ratio in cardiac metaiodobenzylguanidine (MIBG) imaging. Methods: Images of the phantom containing 123I-MIBG were acquired on the cameras in 10 hospitals (11 camera types) to determine the relationship between H/M ratios using different collimators: low-energy (LE) and mediumenergy (ME)/low-medium-energy (LME) collimators. The effect of standardization on the ME-comparable H/M ratio was examined in two settings: a Japanese standard MIBG database (n=62) and multicentre studies (n=49). In a multicentre study, probable Alzheimer\u27s disease (AD, n=18) and probable dementia with Lewy bodies (DLB, n=31) were studied and standardized by the calibration phantom method. Results: Linear regression equations between LE and ME collimators were obtained for the phantom study in all institutions. When the H/M ratio with an LE collimator wascorrected based upon the calibration phantom, the corrected values were comparable to those obtained using ME collimators. The standard database also exhibited a normal distribution after standardization as determined by skewness and goodness-of-fit test. A mixture of the populations by LE and ME collimators showed significant separation of AD and DLB groups (F ratio=24.9 for the late H/M), but the corrected values resulted in higher F ratios for both early and late H/M (F ratio=34.9 for the late H/M). Conclusion: Standardization of H/M ratios by the heartchest calibration phantom method is feasible among different collimator types. This method could be practically used for multicentre comparison of H/M ratios. © Springer-Verlag 2011

D-branes and Closed String Field Theory

We construct BRST invariant solitonic states in the OSp invariant string field theory for closed bosonic strings. Our construction is a generalization of the one given in the noncritical case. These states are made by using the boundary states for D-branes, and can be regarded as states in which D-branes or ghost D-branes are excited. We calculate the vacuum amplitude in the presence of solitons perturbatively and show that the cylinder amplitude for the D-brane is reproduced. The results imply that these are states with even number of D-branes or ghost D-branes.Comment: 36 pages, 3 figures, LaTeX; typos correcte

The time has come to standardize 123I-MIBG heart-to-mediastinum ratios including planar and SPECT methods

Embargo Period 12 month

The relationship between stress-induced myocardial ischemia and coronary artery atherosclerosis measured by hybrid SPECT/CT camera

Objective: The coronary artery calcium (CAC) score and myocardial perfusion imaging can now be detected simultaneously using a hybrid SPECT/CT camera. However, there has been little evaluation on the relationship between stress-induced ischemia and coronary artery calcification in a Japanese population. The aim of this study was to investigate the relationship between these parameters and to elucidate the diagnostic value of the CAC score as an adjunct to myocardial perfusion imaging (MPI) for the assessment of coronary artery disease (CAD) in an intermediate-risk population. Methods: We retrospectively analyzed 105 patients (63% men, mean age 71 years) with CAD or suspected CAD who underwent MPI using SPECT/CT. CAC scanning was performed using a SPECT/CT camera. Results: There was a significant difference in the CAC score between patients with ischemia (n = 42) and those without ischemia (n = 63) (1353 ± 1524 vs. 332 ± 554, p 1000; 3.0 ± 2.0). Higher age is related roughly with higher CAC score with no statistical significance (r 2 = 0.1) (80 years old; 1258 ± 1546, ns). The location of calcification was not related to the ischemic area. In a population with a predominately intermediate likelihood of CAD, a calcium score of zero has a possibility of excluding inducible ischemia on MPI. In part, ischemic MPI is associated with a high likelihood of subclinical atherosclerosis as detected by CAC. Conclusion: Hybrid SPECT/CT might be useful for diagnostic assessment and coronary artery with known or suspected CAD. © 2011 The Japanese Society of Nuclear Medicine

D-brane States and Disk Amplitudes in OSp Invariant Closed String Field Theory

We construct solitonic states in the OSp invariant string field theory, which are BRST invariant in the leading order of regularization parameter $\epsilon$. We calculate the disk amplitudes using these solitonic states and show that they describe D-branes and ghost D-branes.Comment: 37 pages, 8 figure