The aim of this paper is to introduce the notion of commutative pseudo BE-algebras and investigate their properties.We generalize some results proved by A. Walendziak for the case of commutative BE-algebras.We prove that the class of commutative pseudo BE-algebras is equivalent to the class of commutative pseudo BCK-algebras. Based on this result, all results holding for commutative pseudo BCK-...

The essay by the Johns Hopkins Center for Health Security on global catastrophic biological risks (GCBRs) presents an intriguing opportunity to assess the value of discriminating biologically derived risks from other global catastrophic risks (GCRs). Little research has focused on GCRs as a collective field of study, albeit individual types of GCRs have arguably received significant attention (...

Beginners in life history theory or evolutionary ecology seemingly face a variety of almost unrelated approaches. Yet the biomathematical literature of the last 10-20 years reflects the implicit acceptance of a common evolutionary framework, the core idea being that there exists a unique general fitness measure that concisely summarizes the overall time course of potential invasions by initiall...

BACKGROUND AND PURPOSE A successful outcome after lumbar discectomy indicates a substantial improvement. To use the cutoffs for minimal clinically important difference (MCID) as success criteria has a large potential bias, simply because it is difficult to classify patients who report that they are "moderately improved". We propose that the criteria for success should be defined by those who re...

Unlike external fixators, the use of solid intramedullary lengthening nails is restricted to defined anatomical preconditions, such as an adequate bone length. Furthermore, all deformity corrections except the lengthening procedure have to be implemented intraoperatively and cannot be adjusted postoperatively. Conversely, even complex deformity corrections can be performed using intramedullary ...