Threshold and asymptotic behavior of the N D equations

Two important problems involved in obtaining solutions of partial wave dispersion relations (by the N D method) are having (i) the correct threshold behavior, and (ii) an acceptable high energy behavior. Various physical and numerical approximations have been made to insure (i) and (ii). We numerically investigate the sensitivity of the solutions of the N D equations to these approximations. For this purpose, we consider J = 1 π-π scattering, employing elastic unitarity and assuming that the left hand cut is dominated by the exchange of the ρ{variant} resonance. Two significant features we find are: (a) The values of the cutoffs needed to product a resonance are quite sensitive to the input "strength" of the left hand cut, e.g., a change of the input width of the ρ{variant} by a factor of two changed the value for a "straight cutoff" to produce a resonance at a given energy by a factor of ten. Due to the results of (a) we wish to emphasize the possible danger in employing a single cutoff in the calculations of SU3 multiplets. (b) If one introduces a pole on the left hand cut in order to insure the threshold behavior (i), then the ranges in values for the cutoffs (to insure (ii)) for which any resonance occurs are extremely narrow. On the other hand, a solution in which the phase shift does not become large is insensitive to the position of this pole. © 1965

Determination of the S-wave π-π amplitude near the peak from the reaction π-+p→π++π-+n

A fit to recent extensive data for the reaction π-+p→π++π-+n at incident π- momentum ∼4 BeVc and final two-pion center-of-mass energy mππ∼mρ was made. The peripheral model with absorption was used in the fit. The asymmetry in the final two-pion distribution θπ gives a quantitative determination of the π-π, S-wave, I=0 scattering amplitude. A constant phase shift of ∼+60°gives as good a fit the to data as a resonance ε0 (at 730 MeV with a width of 90 MeV), proposed by Durand and Chiu. A negative phase shift of ∼-60°is ruled out by examining the distribution in θπ as a function of mππ. © 1967 The American Physical Society

Absorptive corrections and form factors in the peripheral model

Absorptive corrections applied to the peripheral model have provided a relatively successful interpretation of a variety of high-energy production processes. There exist, however, a number of difficulties associated with these calculations. We consider the reaction πN→ρN, which is dominated by π exchange, in order to study the following three ambiguities: (i) the actual dependence of the absorptive corrections on the initial- and final-state elastic-scattering phase shifts, (ii) the role of a form factor, and (iii) the numerical values of the final-state elastic-scattering phase shifts. The comparison of our calculation with the experimental data, in particular the density matrix of the ρ, leads to the following results. The j=12 partial waves must be totally suppressed by the absorptive corrections and the form factor must play a very minor role in order to fit the observed deviation of the ρ's density matrix from that predicted by the exchange of a π in the peripheral model. (A form factor cuts down the low partial waves in a manner which leaves the density matrix unmodified from the simple peripheral model and thus reduces the effect of absorption corrections on the density matrix.) We expect any form factor associated with π exchange to have a weak t dependence, since there exists no resonance with the appropriate quantum numbers (to couple to the π) with energy 1.3 BeV. It is plausible that form factors (in addition to the absorptive corrections), while unimportant for π exchange, may play a significant role in vector exchange (since there seems to be an abundance of high-spin resonances). © 1965 The American Physical Society

Comments on ππ phase shifts as determined from the peripheral model

The determination of the S-wave ππ phase shifts δ0I at low energy from the analysis of πN→(2π)N is examined critically from the standpoint of the one-pion-exchange model with absorptive corrections. It is found that: (1) The value of δ0I depends strongly on the P-wave phase shifts, which cannot be unambiguously determined, at mππ<600 MeV, by using a Breit-Wigner formula. (2) The ratio of the production density matrix elements ρ (with the ππ elastic scattering amplitudes factored out) depends strongly on mππ for mππ<600 MeV. (3) The (F-B)(F+B) asymmetry shows a sizeable dependence on the momentum transfer t to the nucleon. It is concluded that more accurate data at low mππ are required in order to determine δ0I for mππ<600 MeV. Tables of the ρ(mππ,A t) calculated from the absorption model for an incident-pion laboratory kinetic energy of 4 BeV are included. These could be directly applied to the data to obtain the low-energy ππ phase shifts. © 1968 The American Physical Society

Exotic mesons and e+e- annihilation

Recent experiments at SPEAR indicate an unexpectedly large number of 1 - states in the energy range 3.9-4.4 GeV. We show how the existence of exotic cq̄c̄q mesons can account for these states as well as the rise in R and the missing ψ(3.7) decays. The width of these states does not require that they lie above the, as yet unobserved, DD̄ threshold. Predictions of the model are readily testable. © 1976 The American Physical Society

Absolute quantitation of DNA methylation of 28 candidate genes in prostate cancer using pyrosequencing

This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.Aberrant DNA methylation plays a pivotal role in carcinogenesis and its mapping is likely to provide biomarkers for improved diagnostic and risk assessment in prostate cancer (PCa). We quantified and compared absolute methylation levels among 28 candidate genes in 48 PCa and 29 benign prostate hyperplasia (BPH) samples using the pyrosequencing (PSQ) method to identify genes with diagnostic and prognostic potential. RARB, HIN1, BCL2, GSTP1, CCND2, EGFR5, APC, RASSF1A, MDR1, NKX2-5, CDH13, DPYS, PTGS2, EDNRB, MAL, PDLIM4, HLAa, ESR1 and TIG1 were highly methylated in PCa compared to BPH (p < 0.001), while SERPINB5, CDH1, TWIST1, DAPK1, THRB, MCAM, SLIT2, CDKN2a and SFN were not. RARB methylation above 21% completely distinguished PCa from BPH. Separation based on methylation level of SFN, SLIT2 and SERPINB5 distinguished low and high Gleason score cancers, e.g. SFN and SERPINB5 together correctly classified 81% and 77% of high and low Gleason score cancers respectively. Several genes including CDH1 previously reported as methylation markers in PCa were not confirmed in our study. Increasing age was positively associated with gene methylation (p < 0.0001). Accurate quantitative measurement of gene methylation in PCa appears promising and further validation of genes like RARB, HIN1, BCL2, APC and GSTP1 is warranted for diagnostic potential and SFN, SLIT2 and SERPINB5 for prognostic potential

The relationship between facial skeletal class and expert-rated interpersonal skill: an epidemiological survey on young Italian adults

BACKGROUND: The facial region plays a major role in determining physical attractiveness, so we assessed the hypothesis that the capability of successfully managing interpersonal relationships in young adults might be related to the facial skeletal class. METHODS: 1,014 young subjects applying to the Military Academy of Pozzuoli, Italy, were enrolled and the cephalometric evaluation was performed by calculating the angular relationships between skeletal points localized by the lateral cephalogram of the face, sorting the subjects in three groups corresponding to each major facial skeletal class. Concurrently, the subjects were evaluated by a team of psychiatrists administering the MMPI-2 test followed by a brief colloquium with each candidate, in order to identify those subjects characterized by low skills for managing interpersonal relationships. RESULTS: According to the psychiatric evaluation about 20% of the subjects were considered potentially unable to manage successfully interpersonal relationships (NS). Males displayed an about two-fold increased risk of being NS. No differences were shown in the distribution of the NS male subjects among the three different facial skeletal classes. On the other hand, NS females displayed a different distribution among the three facial skeletal classes, with a trend of about two-fold and four-fold, respectively, for those subjects belonging to classes II and III, respect to those belonging to class I. CONCLUSION: Females may be more sensitive to physical factors determining beauty, such as the facial morphology certainly is. This finding appears to be interesting especially when thinking about possible orthodontic interventions, although further study is certainly needed to confirm these results

Apparatus for histological validation of in vivo and ex vivo magnetic resonance imaging of the human prostate

This article describes apparatus to aid histological validation of magnetic resonance imaging studies of the human prostate. The apparatus includes a 3D-printed patientspecific mold that facilitates aligned in vivo and ex vivo imaging, in situ tissue fixation, and tissue sectioning with minimal organ deformation. The mold and a dedicated container include MRI-visible landmarks to enable consistent tissue positioning and minimize image registration complexity. The inclusion of high spatial resolution ex vivo imaging aids in registration of in vivo MRI and histopathology data