The 1940s and 1950s were marked by intense debates over the origin of drug resistance in microbes. Bacteriologists had traditionally invoked the notions of ‘training’ and ‘adaptation’ to account for the ability of microbes to acquire new traits. As the field of bacterial genetics emerged, however, its participants rejected ‘Lamarckian’ views of microbial heredity, and offered statistical evidence that drug resistance resulted from the selection of random resistant mutants. Antibiotic resistance became a key issue among those disputing physiological vs. genetic (...) explanations of variation in bacteria. Postwar developments connected with the Lysenko affair gave this debate a new political valence.Proponents of the neo-Darwinian synthesis weighed in with support for the genetic theory. However, certain features of drug resistance seemed inexplicable by mutation and selection, particularly the phenomenon of ‘multiple resistance’—the emergence of resistance in a single strain against several unrelated antibiotics. In the late 1950s, Tsutomu Watanabe and his collaborators solved this puzzle by determining that resistance could be conferred by cytoplasmic resistance factors rather than chromosomal mutation. These R factors could carry resistance to many antibiotics and seemed able to promote their own dissemination in bacterial populations. In the end, the vindication of the genetic view of drug resistance was accompanied by a recasting of the ‘gene’ to include extrachromosomal hereditary units carried on viruses and plasmids. (shrink)
An evaluation method, similar to the two-valued one for the classical logic, is introduced to give a decision procedure for some of intermediate logics. The logics treated here are obtained from some logics by adding the axiom av a.
We give a Gentzen-type formulation GQ for the intermediate logic LQ and prove the cut-elimination theorem on it, where LQ is the propositional logic obtained from the intuitionistic propositional logic LI by adding the axioms of the form AV A.
On April 5 2000, the Diet elected Yoshiro Mori as Japan's 55th prime minister. His predecessor, Keizo Obuchi, had suffered a stroke and became unable to carry out his official responsibility. Mori, who was the former Secretary General of the ruling Liberal Democratic Party (LDP), inherited the three party coalition between the LDP, the new Komei Party and the Conservative Party, and reappointed all of Obuchi's cabinet members. Yohei Kono was reposted as the Minister of Foreign Affairs; Hideo Usui as (...) Justice; Kiichi Miyazawa as Finance; Hirofumi Nakasone as Education, Science and Technology; Yuya Niwa as Health and Welfare; Tokuichiro Tanazawa as Agriculture, Forestry and Fisheries; Takeshi Fukaya as International Trade and Industry; Toshihiro Nikai as Transport; Eita Yashiro as Posts and Telecommunications; Takamori Makino as Labor; Masaaki Nakayama as Construction; Kosuke Hori as Home Affairs, Mikio Aoki as Chief Cabinet Secretary; Kunihiro Tsuzuki as Management and Coordination; Tsutomu Kawara as Defense; Taichi Sakaiya as Economic Planning; Kayoko Shimizu as environment; and Sadakazu Tanigaki as Financial Reconstruction. (shrink)
The intermediate logics have been classified into slices (cf. Hosoi ), but the detailed structure of slices has been studied only for the first two slices (cf. Hosoi and Ono ). In order to study the structure of slices, we give a method of a finer classification of slices & n (n 3). Here we treat only the third slice as an example, but the method can be extended to other slices in an obvious way. It is proved that each (...) subslice contains continuum of logics. A characterization of logics in each subslice is given in terms of the form of models. (shrink)