Forcing extensions yield models of ZFC in which a long sequence of club subsets of ω 1 has the following property: every subsequence of size ℵ 1 has a finite intersection.

Quasi-Nelson logic (QNL) was recently introduced as a common generalisation of intuitionistic logic and Nelson's constructive logic with strong negation. Viewed as a substructural logic, QNL is the axiomatic extension of the Full Lambek Calculus with Exchange and Weakening by the Nelson axiom, and its algebraic counterpart is a variety of residuated lattices called quasi-Nelson algebras. Nelson's logic, in turn, may be obtained as the axiomatic extension of QNL by the double negation (or involutivity) axiom, and intuitionistic logic as the (...) extension of QNL by the contraction axiom. A recent series of papers by the author and collaborators initiated the study of fragments of QNL, which correspond to subreducts of quasi-Nelson algebras. In the present paper we focus on fragments that contain the connectives forming a residuated pair (the monoid conjunction and the so-called strong Nelson implication), these being the most interesting ones from a substructural logic perspective. We provide quasi-equational (whenever possible, equational) axiomatisations for the corresponding classes of algebras, obtain twist representations for them, study their congruence properties and take a look at a few notable subvarieties. Our results specialise to the involutive case, yielding characterisations of the corresponding fragments of Nelson's logic and their algebraic counterparts. (shrink)

Until the 1930s Germany had been the international leader in biochemistry, chemistry, and areas of biology. After WWII, however, molecular biology as a new interdisciplinary scientific enterprise was scarcely represented in Germany for almost 20 years. Three major reasons for the low performance of molecular biology are discussed: first, the forced emigration of Jewish scientists after 1933, which not only led to the expulsion of future distinguished molecular biologists, but also to a strong decline of ''dynamic biochemistry'', a field which (...) contributed greatly to molecular biology. Second, German university structures that strongly impeded interdisciplinary research. Third, the international isolation and self-isolation of German scientists that was a major obstacle to the implementation of new fields of research developed elsewhere. Despite the fact that there was no official boycott against Germany as there had been after WWI and despite the Cold War policy of integrating Germans into the West, as a consequence of National Socialism and WWI for many years only very few German scientists gained access to the international community of molecular biologists. Max Delbruck played an important role in helping the Germans establish modern, mostly molecular, biology because he retained strong connections to Germany. Most importantly, it required a new generation of young scientists who had received part of their training in the US to establish modern molecular biology at German universities and Max Planck Institutes. (shrink)

Avery’s et al. ’s 1944 paper provides the first direct evidence of DNA having gene-like properties and marks the beginning of a new phase in early molecular genetics (with a strong focus on chemistry and DNA). The study of its reception shows that on the whole, Avery’s results were immediately appreciated and motivated new research on transformation, the chemical nature of DNA’s biological specificity and bacteria genetics. It shows, too, that initial problems of transferring transformation to other systems and prominent (...) criticism of its results nurtured skepticism. Avery’s experiment was downplayed and neglected particularly by many of those scientists who worked in the new fields of biochemical and biophysical genetics, genetic phage, and TMV research. This was not due to the fact that the implications of the paper could not be connected to generally accepted knowledge. Contrary to a widespread belief, the assumed uniformity of DNA as opposed to proteins was not used as an argument against the validity of Avery’s et al.’s finding. The indifference rather reflected, among other things, the disciplinary gap between the chemically oriented microbiologists and the old and new geneticists who remained committed to genetic and physical methods (in particular x-ray studies) and clung to the assumption that proteins were the sole carriers of biological specificity. The responses to Avery’s et al.’s paper show how different research interests in the areas between microbiology, genetics, and biochemistry interacted with the prejudices, dogmas, individual farsightedness or short-sightedness, and scientific authority during a pivotal period of early molecular biology. (shrink)

Les etudes reunies dans ce volume sont consacrees a l'interpretation des theses principales que defend Aristote en plaidant pour l'exercice d'une veritable politique par le citoyen juste. Ce sont des theses d'un enjeu redoutable. Elles impliquent le plus souvent les conceptions que se fait Aristote des vertus morales et intellectuelles composant le portrait de l'homme, non seulement heureux, mais susceptible d'apporter le bonheur a la Cite. Elles engagent aussi a considerer l'unite profonde que forment, chez Aristote, l'ethique et la politique. (...) A cote d'etudes recemment publiees par l'auteur, le receuil contient d'importants inedits qui font le point sur des questions disputees. L'ensemble peut introduire aux differents aspects de la pensee ethico-politique d'Aristote qui font, aujourd'hui encore, son actualite. (shrink)

Özlem, Doğan; philosophy; biography; Turkey.

Книга рассчитана на студентов, аспирантов, преподавателей высших и средних учебных заведений, всех интересующихся данными исследованиями.

This article argues that the causal loops that occur in some time-travel scenarios and in certain solutions of the theory of relativity are no more mysterious than the infinitely descending causal chains familiar from Newtonian mechanics.