Two nationwide studies examine endoscopist performance and colorectal cancer after colonoscopy. Surveillance screening colonoscopy is based on characteristics of removed adenomas but not the endoscopists. In this issue Gastroenterology, Wieszczy et al examined endoscopists (CRC) risk in a Polish cohort. A total 173,288 colonoscopies were performed between 2000 2011 followed up until 2017. Of 26...

Nowadays there are wide possibilities to perform numerical studies of turbulent natural convection flows on the base of 3D unsteady formulations [1]. Direct Numerical Simulation (DNS) is the most attractive and reliable approach for getting a detailed knowledge on convection [2, 3]. However, DNS applications are practically limited by the case of simplified geometry and/or the Rayleigh numbers ...

Covering models have found many applications in a wide variety of real-world problems; nevertheless, some assumptions of covering models are not realistic enough. Accordingly, a general approach would not be able to answer the needs of encountering varied aspects of real-world considerations. Assumptions like the unavailability of servers, uncertainty, and evaluating more factors at the same ti...

In this note we continue the study of asymptotic invariants of Riemannian tori (e.g. see [BuI] and references there). By asymptotic invariants we mean invariants which do not change under passing to finite covers. In [BuI] we show that the asymptotic volume growth of a Riemannian torus is at least as fast as that of a flat one. One may ask what are the possible values of “asymptotic isoperimetr...

A graph group, or right-angled Artin group, is a group given by a presentation where the only relators are commutators of the generators. A graph group presentation corresponds in a natural way to a simplicial graph, with each generator corresponding to a vertex, and each commutator relator corresponding to an edge. Suppose that G is a graph group whose corresponding graph is a tree and H is a ...