There are 50,024 Kirkman triple systems of order 21 admitting an automorphism of order 2. There are 13,280 Kirkman triple systems of order 21 admitting an automorphism of order 3. Together with the 192 known systems and some simple exchange operations, this leads to a collection of 63,745 nonisomorphic Kirkman triple systems of order 21. This includes all KTS(21)s having a nontrivial automorphi...

Knowledge-based systems must be able to “intelligently” manage a large amount of information coming from different sources and at different moments in time. Intelligent systems must be able to cope with a changing world by adopting a “principled” strategy. Many formalisms have been put forward in the AI and DB literature to address this problem. Among them, belief revision is one of the most su...

With cutaneously applied local anesthetic bases various effects may be observed, such as a decrease in pricking pain and a change in burning, itch, and thermal sensations. These effects occur after skin penetration and may be attributed to the action of the anesthetics on nociceptors and thermoreceptors, i.e., on C and A delta nerve fibers, respectively. As little is known about the pharmacodyn...

helicobacter pylori is the main cause of gastric ulcer, adenocarcinoma and mucosa-associated lymphoid tissue (malt) lymphoma. up to now, different regimens have been used for helicobacter pylori (h.pylori) eradication to find the most potent and cost-effective regimen with less side effects. the aim of this study was to investigate the efficacy of standard triple therapy versus quadruple therap...