In nature, cells face a variety of stresses that cause physical damage to the plasma membrane and cell wall. It is well established that evolutionarily conserved cell cycle checkpoints monitor various cellular perturbations, including DNA damage and spindle misalignment. However, the ability of these cell cycle checkpoints to sense a damaged plasma membrane/cell wall is poorly understood. To the best of our knowledge, our recent paper described the first example of such a checkpoint, using budding yeast as a model. In (...) this review, we will discuss this important question as well as provide hypothetical explanations to be tested in the future. (shrink)

The purpose of this paper is to argue that the hybrid formalism fits naturally in the context of David Lewis’s counterfactual logic and that its introduction into this framework is desirable. This hybridization enables us to regard the inference “The pig is Mary; Mary is pregnant; therefore the pig is pregnant” as a process of updating local information (which depends on the given situation) by using global information (independent of the situation). Our hybridization also has the following technical advantages: (i) (...) it preserves the completeness and decidability of Lewis’s logic; (ii) it allows us to characterize the Limit Assumption as a proof-rule with some side-conditions; and (iii) it enables us to establish a general Kripke completeness result by using the proof-rule corresponding to the Limit Assumption. Keywords Counterfactual logic - David Lewis - Contextually definite description - Hybrid logic - Arthur Prior - The limit assumption - Strong completeness - Decidability - Bisimulation - Pure completeness. (shrink)

The logic of the hide and seek game $$\textbf{LHS}$$ was proposed to capture interactions between agents in pursuit-evasion environments. In this paper, we explore a hybrid extension of $$\textbf{LHS}$$ and show that such an extension is beneficial in several aspects. We will show that it improves the technical properties of the resulting logical system, and expands the potential applications of the system. Specifically, we will investigate the expressive power of the hybrid logic of the hide and seek game $${\mathcal {H}}(\textbf{LHS})$$ (...) and its crucial fragment $${\mathcal {H}}(\textbf{LHS}^{-})$$, at both model and frame levels. We will present complete Hilbert-style proof systems for both the logics $${\mathcal {H}}(\textbf{LHS}^{-})$$ and $${\mathcal {H}}(\textbf{LHS})$$, which in fact provides a solution to a known open problem. (shrink)

This paper deals with two main topics: One is a semantical investigation for a bimodal language with a modal operator \blacksquare associated with the intersection of the accessibility relation R and the inequality ≠. The other is a generalization of some of the former results to general extended languages with modal operators. First, for our language L\sb{\square\blacksquare}, we prove that Segerberg's theorem (equivalence between finite frame property and finite model property) fails and establish both van Benthem-style and Goldblatt-Thomason-style characterizations. We (...) extract the notion of \blacksquare-realizer (a generalization of bulldozing) as an essence from the proofs of our results. Second, we generalize the notion of \blacksquare-realizer and prove quite general versions of these semantical characterization results. The known and previously unknown characterization results for almost all of the languages extended with modal operators already proposed will be immediate corollaries. (shrink)

正しいから証明できるのか、証明できるから正しいのか。数学にとって証明とは何か、正しさとは何なのかは数学基礎論の根本的な問題である。様相論理を軸とした、証明と真理に関わる数学基礎論の古典的な結果から最先 端の議論までを解説した。.

One of the problems we face in many-valued logic is the difficulty of capturing the intuitive meaning of the connectives introduced through truth tables. At the same time, however, some logics have nice ways to capture the intended meaning of connectives easily, such as four-valued logic studied by Belnap and Dunn. Inspired by Dunn’s discovery, we first describe a mechanical procedure, in expansions of Belnap-Dunn logic, to obtain truth conditions in terms of the behavior of the Truth and the False, (...) which gives us intuitive readings of connectives, out of truth tables. Then, we revisit the notion of functional completeness, which is one of the key notions in many-valued logic, in view of Dunn’s idea. More concretely, we introduce a generalized notion of functional completeness which naturally arises in the spirit of Dunn’s idea, and prove some fundamental results corresponding to the classical results proved by Post and Słupecki. (shrink)

Personnalité et irrationalité chez Merleau-PontyUne personnalité est l’ensemble des traits et des qualités propres à une personne spécifique. Il s’agit d’un être humain concret, considéré dans sa totalité et distinct des autres individus. Merleau-Ponty s’est peu intéressé au concept de “personnalité”. Mais il fait référence au concept de totalité pour un individu lorsqu’il parle d’ “existence” ou d’ “être humain”. Grâce à la clarification du concept merleau-pontien de personnalité, je voudrais démontrer ce qui suit : la philosophie merleau-pontienne de la (...) structure caractérise la personnalité humaine comme un tout. Cette idée est héritée du “personnalisme” de la psychologie française inauguré par Ribot. La personnalité ainsi définie possède une rationalité téléologique (un objet visé). Cependant, lorsque Merleau-Ponty propose plus tard le concept d’“institution”, il souligne que toute signification de l’expérience humaine se fonde sur une expérience particulière et sur un point de vue concret ayant valeur de dimension, de niveau, ou encore sur un critère qui donne un sens à l’expérience suivante. S’il en est ainsi, les êtres humains doivent posséder une irrationalité fondamentale au coeur de leur personnalité ; irrationalité désigne une attitude attachée à une expérience particulière ou à un point de vue singulier. Les hommes peuvent “ré-instituer” leur expérience, c’est-à-dire abolir et transformer une dimension, un niveau ou un critère de l’expérience en y intégrant d’autres points de vue à travers leurs relations intersubjectives. Ils gagnent ainsi en nuance et en objectivité. Cependant, ils ne parviennent jamais à une rationalité totale si celle-ci se définit par une pensée totalement objective, universelle et non située, capable de voir le monde de nulle part. La ré-institution pourrait aussi entraîner une rupture dans la personnalité de quelqu’un et la rendre complexe et multiple, sans être pathologique pour autant.Personalità e irrazionalità in Merleau-PontyLa personalità è l’insieme delle qualità e dei tratti peculiari di una certa persona. È un essere umano concreto, preso nella sua interezza e distinto dagli altri individui. Merleau-Ponty non si è mai occupato molto del concetto di “personalità”. Ma si è riferito a tale concetto di totalità di un individuo sotto i nomi di “esistenza” o “essere umano”. Chiarendo la concezione merleau-pontiana della “personalità”, intendo sostenere che la filosofia della struttura di Merleau-Ponty caratterizza la personalità umana come un tutto unificato. Quest’idea è un’eredità del “personalismo” della psicologia francese inaugurata da Ribot. La personalità definita come tale ha una razionalità teleologica (orientata ad un obiettivo). Tuttavia, quando Merleau-Ponty propose più tardi il concetto di “istituzione”, sottolineò più di quanto avesse fatto precedentemente che perché ogni esperienza umana abbia un significato occore stabilire una particolare esperienza ed un punto di vista concreto quale dimensione, livello, o criterio che dia significato all’esperienza successiva. Se così è, gli esseri umani devono avere una fondamentale irrazionalità nel profondo della loro personalità, intendendo con irrazionalità un atteggiamento che è legato ad una particolare esperienza o punto di vista. Gli esseri umani possono “re-istituire” la loro esperienza, ovvero, riconsiderare una dimensione, un livello, o un criterio dell’esperienza attraverso l’integrazione degli altri punti di vista grazie alle loro relazioni intersoggettive. Guadagnano, così, sfumature e obiettività. Tuttavia, non possono mai realizzare la razionalità completa se per razionalità s’intende il pensiero completamente oggettivo, universale, imparziale, che guarda il mondo da nessun luogo. E la re-istituzione potrebbe creare una fessura decisiva nell’identità personale di un uomo, e rendere tale personalità complessa e “multipla,” anche se non necessariamente patologica. (shrink)

The lifeworld is, according to Husserl, the horizon of all our experiences, in the sense that it is the background environment of human being’s competences, practices, and attitudes. The lifeworld is the intersubjective, pre-given in the ontic sense, and immediately perceived world of everyday life. Although Husserl has distinguished the lifeworld from the objective world that natural science describes with mathematical methods, we cannot divide the world on the practical level into the perceived world of ordinary life and the scientific (...) world. The characteristic of human beings is that they live in the environment which they have enormously changed. Modern science has accelerated this tendency: the contemporary world is constructed so deeply scientifically and technologically. Accordingly, as Ulrich Beck pointed out, the risk of the technologically constructed world is often invisible/unperceivable. The disaster at Fukushima nuclear power plants is a terrible testament of this kind of risk. In order for a land to become the lifeworld of meaningful human interactions, the land should be first of all safe and livable for all of us. The risk calculation made by Tokyo Electric Power Company was shown to be sloppy and deceptive. The contemporary techno-science should be democratically governed and watched by all kinds of stakeholders, and never be left it to the specialists of science. For re-establishing the livable and sustainable lifeworld, safety, resilience, and vulnerability should be the fundamental values. And, the autonomy of the local residents, including the most vulnerable people, through the democratization of the techno-science must be the fundamental value to establish and protect such a safe environment. (shrink)

Genome maintenance requires various nucleoid-associated factors in prokaryotes. Among them, the SMC protein has been thought to play a static role in the organization and segregation of the chromosome during cell division. However, recent studies have shown that the bacterial SMC is required to align left and right arms of the emerging chromosome and that the protein dynamically travels from origin to Ter region. A rod form of the SMC complex mediates DNA bridging and has been recognized as a machinery (...) responsible for DNA loop extrusion, like eukaryotic condensin or cohesin complexes, which act as chromosome organizers. Attention is now turning to how the prototype of the complex is loaded on the entry site and translocated on chromosomal DNA, explaining its overall conformational changes at atomic levels. Here, we review and highlight recent findings concerning the prokaryotic SMC complex and discuss possible mechanisms from the viewpoint of protein architecture. Recent studies show dynamic movements of the prokaryotic SMC protein complex: initial loading, translocation on DNA for bacterial chromosome organization. The recent structural models of the protein also provide a new vision for the structure-function relationship. (shrink)

The present contribution shows that a Hilbert-style axiomatization for dynamic logic of relation changers is complete for the standard Kripke semantics not by a well-known rewriting technique but by the idea of an auxiliary semantics studied by van Benthem and Wang et al. A key insight of our auxiliary semantics for dynamic logic of relation changers can be described as: “relation changers are bounded morphisms.” Moreover, we demonstrate that this semantic insight can be used to provide a modular cut-free labelled (...) sequent calculus for the logic in the sense that our calculus can be regarded as a natural expansion of a labelled sequent calculus of iteration-free propositional dynamic logic. (shrink)

The paper is based on a review of research on media selection and related topics on the one hand and on an explorative pilot survey on the other. In summarising the review, the authors propose that the factors explaining media choice be grouped into five categories: (1) the properties of the media itself affect its choice, (2) properties of the user affect media choice, (3) the communication situation plays an important role, (4) macro factors explain media choice, and (5) media (...) choice can be explained as the outcome of a dynamic multiparty negotiation process. The pilot survey compares Japanese and Finnish students’ preference of media in various communication situations. The survey results encourage reserving, local macro factors or culture, a certain amount of explanatory force in explaining media choice. (shrink)