The circadian clock system in the mammalian retina.Gianluca Tosini,Nikita Pozdeyev,KatsuhikoSakamoto &P. Michael Iuvone -2008 -Bioessays 30 (7):624-633.detailsDaily rhythms are a ubiquitous feature of living systems. Generally, these rhythms are not just passive consequences of cyclic fluctuations in the environment, but instead originate within the organism. In mammals, including humans, the master pacemaker controlling 24‐hour rhythms is localized in the suprachiasmatic nuclei of the hypothalamus. This circadian clock is responsible for the temporal organization of a wide variety of functions, ranging from sleep and food intake, to physiological measures such as body temperature, heart rate and hormone release. (...) The retinal circadian clock was the first extra‐SCN circadian oscillator to be discovered in mammals and several studies have now demonstrated that many of the physiological, cellular and molecular rhythms that are present within the retina are under the control of a retinal circadian clock, or more likely a network of hierarchically organized circadian clocks that are present within this tissue. BioEssays 30:624–633, 2008. © 2008 Wiley Periodicals, Inc. (shrink)
Hybrid counterfactual logics David Lewis meets Arthur prior again.Katsuhiko Sano -2009 -Journal of Logic, Language and Information 18 (4):515-539.detailsThe 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)
Combing Chromosomal DNA Mediated by the SMC Complex: Structure and Mechanisms.Katsuhiko Kamada &Daniela Barillà -2018 -Bioessays 40 (2):1700166.detailsGenome 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 German Hercules’s Heir: Pierre Gassendi’s Reception of Keplerian Ideas.KuniSakamoto -2009 -Journal of the History of Ideas 70 (1):69-91.detailsPierre Gassendi is widely known as a reviver of Epicurean atomism. But he was also regarded as an accomplished astronomer by his contemporaries. Along with the life-long observational pursuits, Gassendi developed his theories of the causes underlying celestial motions. In elaborating them, he absorbed seveal ideas coming from the astronomy of Johannes Kepler. Moreover, Gassendi went further to incorporate some theological principles from the Keplerian cosmology, especially the idea that God is a Geometer. The present paper thus explores Kepler's influence (...) on the philosophy of Gassendi in both astronomical and theological spheres. (shrink)
Seimei rinri: 21-seiki no gurōbaru baioeshikkusu.HyakudaiSakamoto,Kiyoshi Aoki &Takao Yamada (eds.) -2005 - Tōkyō: Hokuju Shuppan.details劇的転換を求められている新たな生命倫理の案内書。従来、医療分野に集中しがちであった内容を生命科学全体とさらに関連する社会的緊急課題―環境・人口・難民・人種などにまで拡大、包括して最適任者が興趣ある解説 で応える。.
Uniform versions of some axioms of second order arithmetic.NobuyukiSakamoto &Takeshi Yamazaki -2004 -Mathematical Logic Quarterly 50 (6):587-593.detailsIn this paper, we discuss uniform versions of some axioms of second order arithmetic in the context of higher order arithmetic. We prove that uniform versions of weak weak König's lemma WWKL and Σ01 separation are equivalent to over a suitable base theory of higher order arithmetic, where is the assertion that there exists Φ2 such that Φf1 = 0 if and only if ∃x0 for all f. We also prove that uniform versions of some well-known theorems are equivalent to (...) or the axiom of the existence of the Suslin operator. (shrink)
Julius Caesar Scaliger, Renaissance reformer of Aristotelianism: a study of Exotericae Exercitationes.KuniSakamoto -2016 - Boston: Brill.detailsThis monograph is the first to analyze Julius Caesar Scaliger's Exotericae Exercitationes(1557). In order to make this late-Renaissance work accessible to modern readers, KuniSakamoto conducted a detailed textual analysis and revealed the basic tenets of Scaliger's philosophy.
Combining Intuitionistic and Classical Propositional Logic: Gentzenization and Craig Interpolation.Masanobu Toyooka &Katsuhiko Sano -2024 -Studia Logica 112 (5):1091-1121.detailsThis paper studies a combined system of intuitionistic and classical propositional logic from proof-theoretic viewpoints. Based on the semantic treatment of Humberstone (J Philos Log 8:171–196, 1979) and del Cerro and Herzig (Frontiers of combining systems: FroCoS, Springer, 1996), a sequent calculus \(\textsf{G}(\textbf{C}+\textbf{J})\) is proposed. An approximate idea of obtaining \(\textsf{G}(\textbf{C}+\textbf{J})\) is adding rules for classical implication on top of the intuitionistic multi-succedent sequent calculus by Maehara (Nagoya Math J 7:45–64, 1954). However, in the semantic treatment, some formulas do not (...) satisfy heredity, which leads to the necessity of a restriction on the right rule for intuitionistic implication to keep the soundness of the calculus. The calculus \(\textsf{G}(\textbf{C}+\textbf{J})\) enjoys cut elimination and Craig interpolation, whose detailed proofs are described in this paper. Cut elimination enables us to show the decidability of this combination both directly and syntactically. This paper also employs a canonical model argument to establish the strong completeness of Hilbert system \(\mathbf {C+J}\) proposed by del Cerro and Herzig (Frontiers of combining systems: FroCoS, Springer, 1996). (shrink)
Sympathy and Political Economy in the Scottish Enlightenment.TatsuyaSakamoto -2023 -Journal of Scottish Philosophy 21 (1):53-74.detailsFor the first time, in Hume and Smith, ‘sympathy’ occupies a central position as the principle of moral judgment. The key to solving the relationship between sympathy and economic thought lies in the theory of justice. Hume and Smith inherited Hutcheson’s criticism of the Hobbesian selfish system and considered humans selfish and social. For both, the relationship between selfishness and sympathy is neither a contradiction nor a subordinate structure in which selfishness ultimately dominates sympathy. In this joint project, Hume’s institutional (...) utilitarianism could justify Smith’s economic theories and provide Smith’s theory of government with a proper philosophical foundation. I argue that this is particularly significant because Smith himself failed to provide the foundation in areas where the idea of public utility plays a vital role, such as in the critical case of national defence and the decline of martial spirit. (shrink)
Nursing knowledge: A middle ground exploration.Mariko LietteSakamoto -2018 -Nursing Philosophy 19 (3):e12209.detailsThe discipline of nursing has long maintained that is has a unique contribution to make within the health care arena. This assertion of uniqueness lies in great part in the discipline's claim to a distinct body of knowledge. Nursing knowledge is characterized by diverse and multiple forms of knowing and underpins the work of all nurses, regardless of field of practice. Unfortunately, it has been challenging for the discipline to take full ownership of its epistemological diversity, largely due to factors (...) such as competing worldviews, and ideological and binary positioning. A philosophical middle ground stance is proposed as a way for the discipline to contemplate, discuss and develop nursing knowledge; a middle space that provides the freedom to consider competing worldviews while still allowing for the discipline to fully express itself in all of its epistemological diversity. In being able to enact its multiple forms of knowledge in a creative and open space that is open to different ideas and worldviews, not only can nursing take full ownership of its practice and its unique knowledge, it can also demonstrate how best to navigate an increasingly polarized world. In a world that is increasingly fixated on binary solutions and dualistic points of view, it is time for nursing to celebrate its epistemological diversity. (shrink)
Generalizing Functional Completeness in Belnap-Dunn Logic.Hitoshi Omori &Katsuhiko Sano -2015 -Studia Logica 103 (5):883-917.detailsOne 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)