From Euclidean Geometry to Knots and Nets

This document is the Accepted Manuscript of an article accepted for publication in Synthese. Under embargo until 19 September 2018. The final publication is available at Springer via https://doi.org/10.1007/s11229-017-1558-x.This paper assumes the success of arguments against the view that informal mathematical proofs secure rational conviction in virtue of their relations with corresponding formal derivations. This assumption entails a need for an alternative account of the logic of informal mathematical proofs. Following examination of case studies by Manders, De Toffoli and Giardino, Leitgeb, Feferman and others, this paper proposes a framework for analysing those informal proofs that appeal to the perception or modification of diagrams or to the inspection or imaginative manipulation of mental models of mathematical phenomena. Proofs relying on diagrams can be rigorous if (a) it is easy to draw a diagram that shares or otherwise indicates the structure of the mathematical object, (b) the information thus displayed is not metrical and (c) it is possible to put the inferences into systematic mathematical relation with other mathematical inferential practices. Proofs that appeal to mental models can be rigorous if the mental models can be externalised as diagrammatic practice that satisfies these three conditions.Peer reviewe

Redes Sociais e Comportamento Sexual: para uma visão relacional da sexualidade, do risco e da prevenção

Com base num inquérito representativo da população portuguesa entre 18 e 65 anos, realizado em 2007, este estudo investiga o impacto de fatores de rede social sobre os comportamentos sexuais dos indivíduos. Através da percepção normativa dos inquiridos sobre a moral sexual dos seus amigos e familiares e de indicadores relativos à caracterização da rede de confidência sexual, tais como o número, a identidade, o gênero, a idade e o comportamento dos confidentes em matéria de sexualidade e prevenção face ao risco de infecção por DSTs, obtivemos um retrato multidimensional das redes sociais dos indivíduos. A realização de análises de regressão linear e logística permitiu avaliar o impacto preditivo da rede sobre o número de parceiros sexuais, as relações sexuais ocasionais e o uso do preservativo. Os dados mostram que os fatores de rede são importantes para explicar o comportamento sexual dos indivíduos. Redes constituídas por amigos e mais liberais em termos de moral sexual tendem a influenciar o comportamento sexual, levando a um maior experimentalismo, sobretudo no caso das mulheres. Por outro lado, a homologia entre o comportamento sexual dos confidentes e o dos inquiridos é relevante para explicar o recurso ao preservativo nas relações sexuais ocasionais, especialmente no caso dos homens. Tanto numa perspectiva relacional da sexualidade como numa óptica epidemiológica, a análise das redes sociais dos indivíduos constitui um aspecto importante para a compreensão e explicação da variedade de experiências sexuais, mais restritas ou mais plurais, e para os riscos de infecção que daí podem advir

Taking reincarnation seriously: Critical discussion of some central ideas from John Hick

Reincarnation has not been entirely neglected in the philosophy of religion but it has not always been taken seriously or carefully discussed in relation to its role in believers’ lives. John Hick is exceptional insofar as he gave sustained attention to the belief, at least as it features in the philosophies of Vedānta and Buddhism. While acknowledging the value of Hick’s recognition of the variety of reincarnation beliefs, this article critically engages with certain aspects of his approach. It argues that Hick’s search for a ‘criterion’ of reincarnation is misguided, and that his distinction between ‘factual’ and ‘mythic’ forms of the doctrine is over-simplifying

How to think about informal proofs

This document is the Accepted Manuscript version of the following article: Brendan Larvor, ‘How to think about informal proofs’, Synthese, Vol. 187(2): 715-730, first published online 9 September 2011. The final publication is available at Springer via doi:10.1007/s11229-011-0007-5It is argued in this study that (i) progress in the philosophy of mathematical practice requires a general positive account of informal proof; (ii) the best candidate is to think of informal proofs as arguments that depend on their matter as well as their logical form; (iii) articulating the dependency of informal inferences on their content requires a redefinition of logic as the general study of inferential actions; (iv) it is a decisive advantage of this conception of logic that it accommodates the many mathematical proofs that include actions on objects other than propositions; (v) this conception of logic permits the articulation of project-sized tasks for the philosophy of mathematical practice, thereby supplying a partial characterisation of normal research in the fieldPeer reviewedFinal Accepted Versio

The Consensus from the Mycobacterium avium ssp. paratuberculosis (MAP) Conference 2017.

On March 24 and 25, 2017 researchers and clinicians from around the world met at Temple University in Philadelphia to discuss the current knowledge of Mycobacterium avium ssp. paratuberculosis (MAP) and its relationship to human disease. The conference was held because of shared concern that MAP is a zoonotic bacterium that poses a threat not only to animal health but also human health. In order to further study this problem, the conferees discussed ways to improve MAP diagnostic tests and discussed potential future anti-MAP clinical trials. The conference proceedings may be viewed on the www.Humanpara.org website. A summary of the salient work in this field is followed by recommendations from a majority of the conferees

Viewing scenes of the history of chemistry through the opera glass

Artistic creation has always reflected the spirit of the moment and opera has not been an exception. There are several examples of operas which appeared at key moments of the development of science, portraying them. Additionally there are also operas that emerged after scientific events or the lifetime of the scientists they were inspired on. In what concerns chemistry, the first category could be exemplified by the apothecary operas (already discussed by the author in a previous paper of this journal) while the others could be illustrated by recent operas such as Dr. Atomic or Madame Curie. Continuing our endeavor of establishing relations between opera and chemistry, and considering that history of science plays an important role in the process of teaching and learning sciences, some milestones of the history of chemistry are here revisited through the opera glass. The operas analyzed have been grouped in the following categories: Operas of Fire and Metallurgy, Operas of the Philosophers of Antiquity, Operas of Alchemy, Operas of the Age of Enlightenment, Operas of the Revolutions and Operas of Entropy.Thanks are due to the Foundation for Science and Technology (FCT–Portugal) and FEDER (European Fund for Regional Development)-COMPETE/QREN/EU for financial support through the research unity PEst-C/QUI/UI686/2013.

Neuer Kopf, alte Ideen? : "Normalisierung" des Front National unter Marine Le Pen

In this article, it is investigated whether vibrational entropy (VE) is an important contribution to the free energy of globular proteins at ambient conditions. VE represents the major configurational-entropy contribution of these proteins. By definition, it is an average of the configurational entropies of the protein within single minima of the energy landscape, weighted by their occupation probabilities. Its large part originates from thermal motion of flexible torsion angles giving rise to the finite peak widths observed in torsion angle distributions. While VE may affect the equilibrium properties of proteins, it is usually neglected in numerical calculations as its consideration is difficult. Moreover, it is sometimes believed that all well-packed conformations of a globular protein have similar VE anyway. Here, we measure explicitly the VE for six different conformations from simulation data of a test protein. Estimates are obtained using the quasi-harmonic approximation for three coordinate sets, Cartesian, bond-angle-torsion (BAT), and a new set termed rotamer-degeneracy lifted BAT coordinates by us. The new set gives improved estimates as it overcomes a known shortcoming of the quasi-harmonic approximation caused by multiply populated rotamer states, and it may serve for VE estimation of macromolecules in a very general context. The obtained VE values depend considerably on the type of coordinates used. However, for all coordinate sets we find large entropy differences between the conformations, of the order of the overall stability of the protein. This result may have important implications on the choice of free energy expressions used in software for protein structure prediction, protein design, and NMR refinement

Beyond a Dichotomy of Perspectives: Understanding Religion on the Basis of Paul Natorp’s Logic of Boundary

Based on Paul Natorp’s (1854–1924) late post-Neo-Kantian “Logic of Boundary” (German: “Grenzlogik”) I will offer a methodically controlled, non-reductionist and equally anti-essentialist reconstruction of the notion of religion. The pre-eminent objective of this reconstructive work is to overcome the well-known epistemological as well as methodological problem of a dichotomy between inside and outside perspectives on the subject of religion. Differently put, the objective consists in an attempt to demonstrate that there actually is “reason in religion” that is intellectually accessible for academic knowledge production. Following Natorp’s splendid formulation I will argue that religion operates neither ‘within’ nor ‘beyond’ the ‘boundary of humanity’ but exactly on [or ‘in’] this boundary. More precisely, I will explicate that religious praxis (including its specific production of knowledge) from Natorp’s standpoint can be understood as the performative realization, and habitual embodiment of the (contextually concrete) boundary of humanity or human reason itself. Due to its principial self-referentiality this boundary carries the crucial sense of a first and last positive and, therefore, both in theoretical terms definitive and in practical terms eminently instructive notion of boundary with no outside. This paradoxically all-enclosing, positive boundary, while explicitly including life’s inevitable negativity but, nonetheless, able to ideally sublate it, is the reason why the practice of religion, as empirical evidence unmistakably documents, can provide an incommensurably fulfilling, significant and meaningful closure with regards to the innermost self-perception of its practitioners (concerning their self-determination or agency)