We present nine questions related to the concept of negation and, in passing, we refer connections with essays this special issue. The were submitted one most eminent logicians who contributed theory negation, Prof. (Jon) Michael Dunn, but, unfortunately, Dunn was no longer able answer them. passed away on 5 April 2021, and issue Logical Investigations is dedicated his memory. concern (i) negat...

This study compares the methods of Dunn and Shukla in determining the appropriate insertion length of umbilical catheters. In July 2007, we changed our policy for umbilical catheter insertions from the method of Dunn to the method of Shukla. We report our percentage of inaccurate placement of umbilical-vein catheters (UVCs) and umbilical-artery catheters (UACs) before and after the change of po...

Metastasis is the major cause of death of osteosarcoma patients and its diagnosis remains difficult. In preclinical studies, however, forced expression of reporter genes in osteosarcoma cells has remarkably improved the detection of micrometastases and, consequently, the quality of the studies. We recently showed that Dunn cells equipped with a lacZ reporter gene disseminated from subcutaneous ...