日本政治の実証分析、レヴァイアサン、自由主義的改革、政界再編、ポピュリズム――日本政治研究をリードした「大嶽政治学」の軌跡。.

We say that a subset A of M is implicitly definable in M if there exists a sentence $\phi$ in the language $\mathcal{L} \cup \{P\}$ such that A is the unique set with $ \models \phi$. We consider implicit definability of subfields of a given field. Among others, we prove the following: $\overline{\mathbb{Q}}$ is not implicitly $\emptyset$-definable in any of its elementary extension $K \succ \overline{\mathbb{Q}}$. $\mathbb{Q}$ is implicitly $\emptyset$-definable in any field K with tr.deg $_{\mathbb{Q}}K < \omega$. In a (...) field extension $\mathbb{Q} < K$ with K algebraically closed, $\mathbb{Q}$ is implicitly definable in K if and only if tr.deg $_{\mathbb{Q}}$ is finite. (shrink)

In this paper we define the notion of -linearity for and discuss interpretability (and noninterpretability) of -linear orders in structures and theories.

We consider a problem of constructing a model that omits given complete types. We present two results. The first one is related to the Lopez-Escobar theorem and the second one is a version of Morley's omitting types theorem.

Many functional glycoproteins are expressed on the lymphocyte cell surface. Some of them carry O-linked oligosaccharides (O-glycans), which are conjugated through serine or threonine residues. During various biological processes, including T-cell activation, a tetrasaccharide on the T-cell surface is dramatically converted to a branched hexasaccharide, called core2 O-glycan. The same structural change in O-glycans is also found on the lymphocytes from patients with immunodeficiency conditions such as Wiskott-Aldrich syndrome and AIDS. Several studies revealing the roles of core2 O-glycans in immune (...) responses show that this is a biologically significant change. In particular, core2 O-glycans expressed on the cell surface reduce cell–cell interactions, thereby regulating immune responses. Furthermore, core2 O-glycan is a key backbone structure in forming selectin ligands. Thus, O-linked oligosaccharides, in particular those containing core2 branches, play vital roles in immune responses and may play dual roles in certain situations. This review will summarize the results obtained from various studies investigating the roles of O-glycans in immunological processes. BioEssays 23:46–53, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

In any nonstandard model of Peano arithmetic, the standard part is not first-order definable. But we show that in some model the standard part is definable as the unique solution of a formula , where P is a unary predicate variable.

In his doctoral dissertation, Harold Garfinkel critically examined Talcott Parsons' classical formulation of the problem of order referred to as the Hobbesian problem. Garfinkel's criticism can be summarized under the following three headings: (1) common sense rationality replaces scientific rationality; (2) the level of the premises of conduct replaces the level of de facto action; (3) congruence theory replaces the correspondence theory. The aim of this paper is to make some observations on the structure of the problem of order which (...) Garfinkel discovered through this criticism. I propose to call it the Rashomon problem after Akira Kurosawa's film Rashomon. Ethnomethodology can be regarded as an attempt to solve the Rashomon problem. (shrink)

明治の草創期に、学校教育に欧米式の方法が導入されて以来、子どもたちの直観や自発性を重視したペスタロッチーとフレーベルの教育思想は、戦後にいたるまで日本の教育に強い影響力を与え続けてきた。二人の教育思想 はどのように受容され、実践されてきたのだろうか。その理想に共鳴した教育者・教育学者の足跡からたどる。.

We discuss the possibility of applying the compactness theorem to the study of finite structures. Given a class of finite structures, it is important to determine whether it can be expressed by a particular category of sentences. We are interested in this type of problem, and use nonstandard method for showing the non‐expressibility of certain classes of finite graphs by an existential monadic second order sentence.

The presence of small polydisperse extrachromosomal circular (spc) DNAs composed entirely of chromosomal sequences seems to reflect the plasticity of eukaryotic genomes. The size distribution and number of spc DNAs is found to vary with development, growth state and mitotic capacity. In particular, spc DNAs are observed to be several fold smaller in established immortal cell lines than in diploid cells with a limited life span. Analysis of cloned spc DNA fragments revealed that: (1) most of the spc DNAs thus (...) far investigated contain repetitive sequences; (2) some of the repetitive sequences are enriched in spc DNA clones relative to their representation in the chromosome; (3) various repetitive sequences of different reiteration frequency were found in spc DNA from immortal cell lines while a particular sequence of retroposon was predominant in primary lymphoid tissue cells and stem cells; (4) most of these spc DNAs appear to represent the extra copies generated by replicon‐misfiring in immortal cell lines or by retrotranscription in stem cells, and intermediates or by‐products produced by abortive rearrangement in diploid cells with a finite replicative capacity. (shrink)

In this note we treat maximal and minimal normal subgroups of a superstable group and prove that these groups are definable under certain conditions. Main tool is a superstable version of Zil'ber's indecomposability theorem.

Many functional glycoproteins are expressed on the lymphocyte cell surface. Some of them carry O-linked oligosaccharides (O-glycans), which are conjugated through serine or threonine residues. During various biological processes, including T-cell activation, a tetrasaccharide on the T-cell surface is dramatically converted to a branched hexasaccharide, called core2 O-glycan. The same structural change in O-glycans is also found on the lymphocytes from patients with immunodeficiency conditions such as Wiskott-Aldrich syndrome and AIDS. Several studies revealing the roles of core2 O-glycans in immune (...) responses show that this is a biologically significant change. In particular, core2 O-glycans expressed on the cell surface reduce cell–cell interactions, thereby regulating immune responses. Furthermore, core2 O-glycan is a key backbone structure in forming selectin ligands. Thus, O-linked oligosaccharides, in particular those containing core2 branches, play vital roles in immune responses and may play dual roles in certain situations. This review will summarize the results obtained from various studies investigating the roles of O-glycans in immunological processes. BioEssays 23:46–53, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

We introduce several concepts concerning the indiscernibility of trees. A tree is by definition an ordered set such that, for any a∈O, the initial segment {b∈O:b (...) A of the form η∈O, where O is a tree, and aη labeled by η is an element in M. Such a set A is also called a tree in this paper. We study the indiscernibility of trees A in general settings and apply the obtained results to the study of unstable theories. (shrink)

時代の肌理に触れると同時に、時代を超える感度を研ぎ澄ますには、哲学という経験の刷新が必須となる。今、哲学に何を希望できるのか?自分自身が今を生きる一個の希望となるように、哲学それ自身が変貌しなければな らない。.