Cutlery and Allied Trades Research Association Cutlery and Allied Trades Research Association Cutlery and Allied Trades Research Association (CATRA) is an internationally known research and technology organisation in Sheffield, England which specialises in knives, cutlery, tableware, metallic holloware (such as saucepans), shaving razors, industrial knives/ blades and hand/garden tools. CATRA was originally set up by the British Government in 1952 to carry out developments for the UK's cutlery and knife industries, for which the area of Sheffield in Yorkshire is world-famous. CATRA has developed a range of unique machines for measuring the cutting performance of all types of cutting edges from razor blades to large knives
David ben Judah Messer Leon David ben Judah Messer Leon David ben Judah Messer Leon (c. 1470 in Venice – c. 1526 in Salonica) was an Italian rabbi, physician and writer, who defended the value of secular disciplines and the Renaissance humanities as an important part of traditional Jewish studies. David ben Judah was educated at Naples in the school of his father, Judah Messer Leon, author of "Libnat ha-Sappir", and received at the age of eighteen his rabbinical diploma from German and French Talmudic authorities. Soon afterward he went to Padua, where he studied under Judah Minz, who granted him a new rabbinical diploma.