Spectroscopic factor and proton formation probability for the d3/2 proton emitter 151mLu

The quenching of the experimental spectroscopic factor for proton emission from the short-lived d3/2 isomeric state in 151mLu was a long-standing problem. In the present work, proton emission from this isomer has been reinvestigated in an experiment at the Accelerator Laboratory of the University of Jyväskylä. The proton-decay energy and half-life of this isomer were measured to be 1295(5) keV and 15.4(8) μs, respectively, in agreement with another recent study. These new experimental data can resolve the discrepancy in the spectroscopic factor calculated using the spherical WKB approximation. Using the R-matrix approach it is found that the proton formation probability indicates no significant hindrance for the proton decay of 151mLu

Confirmation of triple shape coexistence in 179Hg: Focal plane spectroscopy of the α decay of 183Pb

The α decay of 183Pb has been studied in detail at the focal plane of the RITU gas-filled separator. The four previously known α decay branches have been ordered into the decay of two isomers in 183Pb. The deduced decay scheme and the interpretation of the inferred α decay hindrance factors and γ rays observed at the focal plane are strongly in favor of the recent suggestion of triple shape coexistence-oblate, prolate, and near-spherical in the daughter nucleus 179Hg

ALK-positive histiocytosis: a new clinicopathologic spectrum highlighting neurologic involvement and responses to ALK inhibition

ALK-positive histiocytosis is a rare subtype of histiocytic neoplasm first described in 2008 in three infants with multisystemic disease involving the liver and hematopoietic system. This entity has subsequently been documented in case reports and series to occupy a wider clinicopathologic spectrum with recurrent KIF5B-ALK fusions. The full clinicopathologic and molecular spectra of ALK-positive histiocytosis remain, however, poorly characterized. Here, we describe the largest study of ALK-positive histiocytosis to date, with detailed clinicopathologic data of 39 cases, including 37 cases with confirmed ALKrearrangements. The clinical spectrum comprised distinct clinical phenotypic groups: infants with multisystemic disease with liver and hematopoietic involvement, as originally described (Group 1A: 6/39), other patients with multisystemic disease (Group 1B: 10/39), and patients with single-system disease (Group 2: 23/39). Nineteen patients of the entire cohort (49%) had neurologic involvement (seven and twelve from Groups 1B and 2, respectively). Histology included classic xanthogranuloma features in almost one third of cases, whereas the majority displayed a more densely cellular, monomorphic appearance without lipidized histiocytes but sometimes more spindled or epithelioid morphology. Neoplastic histiocytes were positive for macrophage markers and often conferred strong expression of phosphorylated-ERK, confirming MAPK pathway activation. KIF5B-ALK fusions were detected in 27 patients, while CLTC-ALK, TPM3-ALK, TFG-ALK, EML4-ALK and DCTN1-ALK fusions were identified in single cases. Robust and durable responses were observed in 11/11 patients treated with ALK inhibition, ten with neurologic involvement. This study presents the existing clinicopathologic and molecular landscape of ALK-positive histiocytosis, and provides guidance for the clinical management of this emerging histiocytic entity.Molecular tumour pathology - and tumour genetic

Friends need a bit more: Maintaining invariants over shared state

Abstract. A friendship system is introduced for modular static verification of object invariants. It extends a previous methodology, based on ownership hierarchy encoded in auxiliary state, to allow for state dependence across ownership boundaries. Friendship describes a formal protocol for a granting class to grant a friend class permission to express its invariant over fields in the granting class. The protocol permits the safe update of the granter’s fields without violating the friend’s invariant. The ensuing proof obligations are minimal and permit many common programming patterns. A soundness proof is sketched. The method is demonstrated on several realistic examples, showing that it significantly expands the domain of programs amenable to static verification.

Using History Invariants to Verify Observers

This paper contributes a technique that expands the set of object invariants that one can reason about in modular verification. The technique uses history invariants, two-state invariants that describe the evolution of data values. The technique enables a flexible new way to specify and verify variations of the observer pattern, including iterators. The paper details history invariants and the new kind of object invariants, and proves a soundness theorem

Proving Consistency of Pure Methods and Model Fields

Pure methods and model fields are useful and common specification constructs that can be interpreted by the introduction of axioms in a program verifier’s underlying proof system. Care has to be taken that these axioms do not introduce an inconsistency into the proof system. This paper describes and proves sound an approach that ensures no inconsistencies are introduced. Unlike some previous syntax-based approaches, this approach is based on semantics, which lets it admit some natural but previously problematical specifications. The semantic conditions are discharged by the program verifier using an SMT solver, and the paper describes heuristics that help avoid common problems in finding witnesses with trigger-based SMT solvers. The paper reports on the positive experience with using this approach in Spec# for over a year