Neural Network Parameterizations of Electromagnetic Nucleon Form Factors

The electromagnetic nucleon form-factors data are studied with artificial feed forward neural networks. As a result the unbiased model-independent form-factor parametrizations are evaluated together with uncertainties. The Bayesian approach for the neural networks is adapted for chi2 error-like function and applied to the data analysis. The sequence of the feed forward neural networks with one hidden layer of units is considered. The given neural network represents a particular form-factor parametrization. The so-called evidence (the measure of how much the data favor given statistical model) is computed with the Bayesian framework and it is used to determine the best form factor parametrization.Comment: The revised version is divided into 4 sections. The discussion of the prior assumptions is added. The manuscript contains 4 new figures and 2 new tables (32 pages, 15 figures, 2 tables

Long-term recurrence rate of large and difficult to treat cutaneous squamous cell carcinomas after superficial radiotherapy

Background: Surgical excision is the gold standard for cutaneous squamous cell carcinoma (cSCC), however its application is limited in specific cases. Superficial radiotherapy (RTx)is an alternative treatment option, but long-term follow-up data are limited. Objective: To determine the outcome of superficial RTx of cSCC in correlation to histological differentiation grade and tumor localization. Methods: The outcome of 180 large cSCCs after superficial RTx between 1960 and 2004 was retrospectively reviewed. Results: Mean tumor size was 3.5 cm 2 (SD 7.5) and mean follow-up period was 4.9 years (SD 4.7). Relapse-free survival was 95.8 and 80.4% after 1 and 10 years. Two-year relapse-free survival was 94.8% for good, 88.9% for moderate and 85.7% for poor differentiated tumors. Five-year relapse-free survival was highest in cSCCs located around the eyes (100%) and cheeks (90.9%). Conclusion: Superficial RTx is an effective alternative for cSCC if surgery is difficult due to localization or concomitant disease

Unique Access to u-Channel Physics: Exclusive Backward-Angle Omega Meson Electroproduction.

Backward-angle meson electroproduction above the resonance region, which was previously ignored, is anticipated to offer unique access to the three quark plus sea component of the nucleon wave function. In this Letter, we present the first complete separation of the four electromagnetic structure functions above the resonance region in exclusive ω electroproduction off the proton, ep→e^{'}pω, at central Q^{2} values of 1.60, 2.45  GeV^{2}, at W=2.21  GeV. The results of our pioneering -u≈-u_{min} study demonstrate the existence of a unanticipated backward-angle cross section peak and the feasibility of full L/T/LT/TT separations in this never explored kinematic territory. At Q^{2}=2.45  GeV^{2}, the observed dominance of σ_{T} over σ_{L}, is qualitatively consistent with the collinear QCD description in the near-backward regime, in which the scattering amplitude factorizes into a hard subprocess amplitude and baryon to meson transition distribution amplitudes: universal nonperturbative objects only accessible through backward-angle kinematics