Deep Inelastic Lepton Scattering in Nuclei at x > 1 and the Nucleon Spectral Function

The nuclear structure function F_2A(x) has been studied in the Bjorken limit for (l, l') scattering on nuclei in the region of x > 1 and was found to be very sensitive to the information contained in the nucleon spectral function in nuclei, particularly the correlations between momenta and energies in the region of large momenta. Calculations were done in a local density approximation using two different spectral functions for nuclear matter. Results are compared to those obtained for a spectral function which has been evaluated directly for the finite nucleus, ^{16}O, under consideration. For values of x around 1.5 and larger the quasiparticle contribution is negligible, thus stressing the sensitivity of the present reaction to the dynamical properties of nuclei beyond the shell model approach. Several approximations which are usually employed in studies of the EMC effect have been analyzed and their inaccuracy in this region is demonstrated. The results stress the fact that the nuclear structure function contains important information on nuclear dynamical correlations. Therefore further measurements of F_2A(x) in that region and for many nuclei would be most welcome.Comment: 24 pages, LaTeX, 11 PostScript figures, final version to appear in Nuclear Physics

THE PROGNOSTIC IMPACT OF ERYTHROID DYSPLASIA IN APLASTIC ANEMIA AND MYELODYSPLASTIC NEOPLASMS WITH SINGLE-LINEAGE DYSPLASIA

Introduction: While genetic aberrations are becoming increasingly critical in disease classification, morphological abnormalities defined by a 10% threshold in each lineage continue to play a significant role as a diagnostic tool for myelodysplastic neoplasms (MDS). However, erythroid lineage dysplasia has been reported in some cases of aplastic anemia (AA), a phenomenon noted as common in the UK guidelines. Methods: We assessed the impact of erythroid dysplasia on the survival in AA patients enrolled in an ongoing prospective registry, central morphological review (blinded), and follow-up study of AA and MDS conducted by the Japanese National Research Group on Idiopathic Bone Marrow Failure Syndromes. Furthermore, we compared the prognosis of AA patients with erythroid dysplasia with that of patients diagnosed in the same study with MDS presenting with single-lineage erythroid dysplasia (“MDS-SLED”). According to this study's definition, the criteria for excluding MDS are stringent, considering both bone marrow cellularity and megakaryocyte counts. Therefore, AA is not diagnosed when a decrease is not observed in the megakaryocyte count. Results: The study included a total of 32 cases of AA with erythroid dysplasia, 56 cases of AA without dysplasia, and 47 cases of MDS-SLED. The overall survival or leukemia-free survival showed no significant difference between AA patients with and without erythroid dysplasia (both p=0.14). Nevertheless, distinct differences were seen between AA with erythroid dysplasia and those diagnosed with MDS-SLED (both p<0.0001). Conclusions: Erythroid dysplasia should not exclude an AA diagnosis. In particular, megakaryocyte count plays an important role in differentiating between MDS from AA

BACKWARD PARTICLE PRODUCTION IN NEUTRINO NEON INTERACTIONS

Backward proton and pion production is studied in ν and {Mathematical expression} charged current interactions in neon. The results are compared with other experiments and theory. The complete backward proton data is compatible with protons produced by reinteractions in the nucleus. However in events with only one proton, muon variables appear correlated to those for the backward proton, as expected by the two-nucleon correlation model. © 1989 Springer-Verlag