The non-random mixing of biomembrane components, especially saturated phospholipids, exhibits important consequences in molecular biology. Particularly, the distribution of lipids within natural and model membranes is strongly determined by the selective association processes. These processes of phospholipids take place due to the cooperative modes in multiparticle systems as well as the specific lipid-lipid interactions both in the hydrophobic core and in the region of the polar headgroups. We demonstrated that the investigation of the selective association processes of saturated phospholipids might (...) contribute to the insight of the lipid domains appearance inside the bilayer membranes. The association probabilities of like-pairs and cross-pairs from a binary mixture of saturated phospholipids were tested for both parallel and anti-parallel alignments of the polar headgroups. The present model confirms the experimental evidence for saturated phospholipids to have a high tendency for association in parallel configuration of the electric dipole moments of the polar headgroups whether the cross-sectional area of the polar headgroup is in an usual range of 25-55 2. There are three major lipid domains in a binary mixture of saturated phospholipids: (i) lipid domains in non-mixed phase of the first mixture component, in parallel alignment of the polar headgroups; (ii) lipid domains in non-mixed phase of the second mixture component, in anti-parallel alignment of the polar headgroups; (iii) lipid domains in mixed phase. We think that the selective association processes of phospholipids are neither exclusively, nor only involved in promoting the lipid domains appearance through bilayer phospholipid membranes. (shrink)
In this paper we consider, and reject, Harold Langsams defenceof the Theory of Appearing, in this journal (1997), in the faceof three standard arguments against it. These arguments are:the argument from hallucination; the argument from the samecause-same effect principle; and the argument from perceptualtime-gap.
Explaining phenomenal consciousness may be the scientific and philosophical problem of our time, the last frontier of knowledge. This is not at all an easy task. For any serious attempt at finding a place for consciousness within the natural world was not successful so far. There is a conceptual tension here which makes this business of coming up with a unified (monist) explanation of mind and physical world one of the most intriguing mystery. The most predominant image of the natural (...) world is one of a physicalist type, whereas the mind, and especially the conscious subjective experience seem not to fit well within that physicalistexplanation. That explanatory failure may require a dualist metaphysical scheme (probably of a neo-Cartesian type). It may seem very well that we are caught in a dilemma, for we either embrace a physicalist explanation, but then it seems that we leave out consciousness from the big picture we are looking for, or else we face the huge task of conceiving a dramatic change of our scientific outlook about the natural world, and we don’t quite see how that would be possible or desirable. But then, should any attempt at understanding consciusness be a dead-end, something doomed to fail from a theoretical and explanatory point of view? In my paper I explore some philosophical underpinnings of contemporary dualism, focussing on the modal facets of the conceivability (neo-Cartesian) arguments. I will asses both the prospects and the moot points of this type of arguments. Of particular interest is the role that two-dimensional semantics plays in nowadays discussions of this topic. (shrink)
In Reference without Referents, Mark Sainsbury aims to provide an account of reference that honours the common-sense view that sentences containing empty names like "Vulcan" and "Santa Claus" are entirely intelligible, and that many such sentences -"Vulcan doesn't exist", "Many children believe that Santa Claus will give them presents at Christmas", etc.- are literally true. Sainsbury's account endorses the Davidsonian program in the theory of meaning, and combines this with a commitment to Negative Free Logic, which holds that all simple (...) sentences containing empty names are false. In this critical review, we pose a number of problems for this account. In particular, we question the ability of Negative Free Logic to make appropriate sense of the truth of familiar sentences containing empty names, including negative existential claims like "Vulcan doesn't exist". /// En Reference without Referents, Mark Sainsbury se propone ofrecer una explicación de la referencia que respete la idea de sentido común de que las oraciones con nombres vacíos como "Vulcano" y "Santa Claus" son completamente inteligibles, y que muchas de oraciones de este tipo -"Vulcano no existe", "Muchos niños creen que Santa Claus les traerá regalos en Navidad", y demás- son literalmente verdaderas. La propuesta de Sainsbury se inscribe dentro del programa davidsoniano en teoría del significado, y combina éste con un compromiso con la Lógica Libre Negativa, según la cual todas las oraciones simples que contienen nombres vacíos son falsas. En este estudio crítico, presentamos varios problemas de esta explicación. En particular, ponemos en duda la habilidad de la Lógica Libre Negativa de entender de manera apropiada la verdad de oraciones conocidas que contienen nombres vacíos, incluidas negaciones de existencia como "Vulcano no existe". (shrink)
Rawls' original position is a thought experiment by which we are asked to imagine ourselves as rational agents choosing the principles of justice under specific informational and motivational constraints. In this paper, I am concerned only with the informational constraints and I shall argue that the way Rawls designed them reveals an implausible conception of mind and knowledge. This conception, of a mind separable from knowledge, as well as one of its correlates which I will call epistemic egalitarianism, is not (...) an objection one may address uniquely to the original position. However, the failure to construct the original position as a one-solution problem renders its epistemology not only implausible but of no use for moral reasoning. (shrink)
Brain drain critiques and human rights advocates have conflicting views on emigration. From a brain drain perspective, the emigration harms a country when emigrants are skilled and the source country is poor. From the human rights perspective, the right "to leave any country, including one's own" is a fundamental right, protected for all, whatever their skills. Is the concern with poverty and social justice at odds with the right to emigrate? At the beginning of the l970s, the economist Jagdish Bhagwati (...) replied in the negative. He imagined a tax on the income earned by the skilled migrants in the destination country, to the benefit of the source country. He thus sought to reconcile the right to emigration and the brain drain effects. -/- This article argues that there is no need to tax skilled migrants in order to reconcile the right to emigration and social justice. Social justice is not incompatible with the right to emigration but rather with restrictions on mobility. If it is both the case that equal opportunities are a minimal requisite for social justice, and that access to opportunities implies freedom of movement, as I shall argue, then the brain drain criticism doesn't satisfy the minimal requirements of social justice. -/- The article is divided into three parts. Each part rejects one of the possible justifications of the Bhagwati tax, that is, as a way, for skilled migrants, (i.) to compensate the welfare loss occasioned to their country of origin; (ii.) to discharge for their obligation to the national community when it publicly financed their education; and (iii.) to compensate for the resulting inequality of opportunities between themselves and their non-migrant compatriots. (shrink)
The Extended Mind Hypothesis (EMH) needs a defence of phenomenal externalism in order to be consistent with an indispensable condition for attributing extended beliefs, concerning the conscious past endorsement of information. However, it is difficult, if not impossible, to envisage such a defence. Proponents ofthe EMH are thus confronted with a difficult dilemma: they either accept absurd attributions of belief, and thus deflate EMH, or incorporate, for compatibility reasons, the conscious past endorsement condition for extended belief attribution, implying a seemingly (...) unavailable defence of phenomenal externalism, and thus risk inconsistency within EMH. Either way, EMH is threatened. (shrink)
In the conventional approach to quantum mechanics, indeterminism is an axiom and nonlocality is a theorem. We consider inverting the logical order, making nonlocality an axiom and indeterminism a theorem. Nonlocal “superquantum” correlations, preserving relativistic causality, can violate the CHSH inequality more strongly than any quantum correlations.
The Greenberger-Horne-Zeilinger state is the most famous example of a state with multiparticle entanglement. In this article we describe a group theoretic framework we have been developing for understanding the entanglement in general states of two or more quantum particles. As far as entanglement is concerned, two states of n spin-1/2 particles are equivalent if they are on the same orbit of the group of local rotations (U(2)n). We consider both pure and mixed states and calculate the number of independent (...) parameters needed to describe such states up to this equivalence. We describe how the entanglement of states in a given equivalence class may be characterized by the stability group of the action of the group of local rotations on any of the states in the class. We also show how to calculate invariants under the group of local actions for both pure and mixed states. In the case of mixed states we are able to explicitly exhibit sets of invariants which allow one to determine whether two generic mixed states are equivalent up to local unitary transformations. (shrink)
It is often argued that development aid can and should compensate the restrictions on migration. Such compensation, Shachar has recently argued, should be levied as a tax on citizenship to further the global equality of opportunity. Since citizenship is essentially a ‘birthright lottery’, that is, a way of legalizing privileges obtained by birth, it would be fair to compensate the resulting gap in opportunities available to children born in rich versus poor countries by a ‘birthright privilege levy’. This article sets (...) out a defence of three theses. The first states that equality of opportunity is incompatible with, and cannot be achieved in, segregated territories. The second posits that to believe that material equality compensates the injustice of restrictions on movement is to commit a ‘sedentarist mistake’. The third affirms that any citizenship levy, including the egalitarian and non-sedentarist formula I’m proposing, would be better understood as a penalty rather than a tax. (shrink)
The living world is an exciting and inexhaustible source of high performance solutions to the multitude of biological problems, which were attained as a result of a natural selection, during the millions and millions years evolution of life on Earth. This work presents and comments some examples of high performances of living beings, in the light of the universal principle governing the realm of living matter: Optimal Design Principle. At the same time, the transfer of these optimal solutions, from living (...) matter to the technologies, is also discussed. This transfer is offering new and fertile perspectives to future technologies, which must be more efficient, cheaper and in perfect harmony with the biosphere. (shrink)
We introduce Łukasiewicz-Moisil relation algebras, obtained by considering a relational dimension over Łukasiewicz-Moisil algebras. We prove some arithmetical properties, provide a characterization in terms of complex algebras, study the connection with relational Post algebras and characterize the simple structures and the matrix relation algebras.
Are intellectual property rights for talented people justified by Rawls’ criteria of justice? In this paper, I argue that Rawls’ theory of justice is ill-equipped to answer this question. Tailored for rival goods and, as a result, centred on the distribution of benefits, it tends to restate questions of justice about unequal rights as questions about economic inequalities. Therefore, it lacks the tools necessary to distinguish among different forms of incentives for talented people. Once social and economic inequalities observe equality (...) of opportunity and improve the least advantaged, the theory is indifferent as to whether talented people are allowed to compete for monopoly rights or for direct financial reward. (shrink)
The paper examines some presuppositions of toleration and pluralism and explores two models, a deontological and a consequentialist model, that could support the view that rational agents should act in a tolerant way. Within the first model two arguments are given in favor of the view that people are better off and more rational if they are tolerant. The first argument draws upon a principle of charity that one usually makes use of in philosophy of mind and philosophy of language, (...) but which could work equally well with regard to this foundational issue in ethics and philosophy of action. The second argument is built upon the epistemic principle of fallibilism and is meant to show that from this vantage point acting in a tolerant way is the rational thing to do. (shrink)
We introduce the notion of n-nuanced MV-algebra by performing a Łukasiewicz–Moisil nuancing construction on top of MV-algebras. These structures extend both MV-algebras and Łukasiewicz–Moisil algebras, thus unifying two important types of structures in the algebra of logic. On a logical level, n-nuanced MV-algebras amalgamate two distinct approaches to many valuedness: that of the infinitely valued Łukasiewicz logic, more related in spirit to the fuzzy approach, and that of Moisil n-nuanced logic, which is more concerned with nuances of truth rather than (...) truth degree. We study n-nuanced MV-algebras mainly from the algebraic and categorical points of view, and also consider some basic model-theoretic aspects. The relationship with a suitable notion of n-nuanced ordered group via an extension of the Γ construction is also analyzed. (shrink)
The lack of double negation and de Morgan properties makes fuzzy logic unsymmetrical. This is the reason why fuzzy versions of notions like closure operator or Galois connection deserve attention for both antiotone and isotone cases, these two cases not being dual. This paper offers them attention, comming to the following conclusions: – some kind of hardly describable ‘‘local preduality’’ still makes possible important parallel results; – interesting new concepts besides antitone and isotone ones (like, for instance, conjugated pair), that (...) were classically reducible to the first, gain independency in fuzzy setting. (shrink)
We prove an institutional version of A. Robinson’s Consistency Theorem. This result is then appliedto the institution of many-sorted first-order predicate logic and to two of its variations, infinitary and partial, obtaining very general syntactic criteria sufficient for a signature square in order to satisfy the Robinson consistency and Craig interpolation properties.
In trying to control various aspects concerning utterance production in multi-party human–computer dialogue, argumentative considerations play an important part, particularly in choosing appropriate lexical units so that we fine-tune the degree of persuasion that each utterance has. A preliminary step in this endeavor is the ability to place an ordering relation between semantic forms (that are due to be realized as utterances, by the machine), concerning their persuasion strength, with respect to certain (explicit or implicit) conclusions. Thus, in this article, (...) we propose a mechanism for assessing utterances, in terms of their argumentative force. The framework designed conflates insights from Asher and Lascarides’ SDRT (“Segmented Discourse Representation Theory”), and from Anscombre and Ducrot’s AT (“Argumentation Theory”). These mechanisms are included in a language generation component of a multi-party dialogue system for book reservation applications (i.e., a “virtual librarian”), and thus evaluated via typical human–machine conversations. (shrink)
A theoretical divide exists on the study of the adapted psychological mechanisms underlying human culture. It has been said for instance that we evolved a brain for all seasons (William Calvin) and that this is opposed to the framework of the modularity of mind (Kim Sterelny or David Buller, inter alia). We approach the nature of these explanatory differences based on what we judge to be a misunderstanding with respect to the evolution of domain-specific modules. We underline the fact that (...) the input-domain of a module and its ecological function should not be conflated. We propose a more generous way of considering how evolutionary functions in mental architecture account for the possibility of general adaptations for cultural cognition. We show that modularity happens to be a good tool to research and decompose mechanisms with plastic functions such as in some forms of social learning. The idea of "modules for all seasons" is so vindicated. Existe una divisoria teórica en el estudio de los mecanismos psicológicos biológicamente adaptados que subyacen a la cultura humana. Se ha dicho, por un lado, que hemos evolucionado un cerebro para todas las estaciones (William Calvin), lo que se opone, por el otro, al marco de la modularidad de la mente (Kim Sterelny o David Buller, entre otros). Consideramos la naturaleza de estas diferencias explicativas sobre la base de lo que nos parece un error de comprensión acerca de la evolución de módulos específicos de dominio. Subrayamos el hecho de que el dominio de entrada de un módulo y su función ecológica no deben ser confundidos. Proponemos una manera más generosa de considerar cómo las funciones evolutivas de la arquitectura mental pueden dar cuenta de la posibilidad de adaptaciones generales a la cognición cultural. Mostramos que la modularidad resulta ser un buen instrumento para investigar y descomponer mecanismos con funciones plásticas, como las que encontramos en algunas formas de aprendizaje social. De este modo, se defiende la idea de "módulos para todas las estaciones". (shrink)
Hardy’s nonlocality is a “nonlocality proof without inequalities”: it exemplifies that quantum correlations can be qualitatively stronger than classical correlations. This paper introduces variants of Hardy’s nonlocality in the CHSH scenario which are realized by the PR-box, but not by quantum correlations. Hence this new kind of Hardy-type nonlocality is a proof without inequalities showing that superquantum correlations can be qualitatively stronger than quantum correlations.
Some physicists seem to believe that quantum information theory requires a new concept of information (Jozsa, 1998, Quantum information and its properties. In: Hoi-Kwong Lo, S. Popescu, T. Spiller (Eds.), Introduction to Quantum Computation and Information, World Scientific, Singapore, (pp. 49-75); Deutsch & Hayden, 1999, Information flow in entangled quantum subsystems, preprint quant-ph/9906007). I will argue that no new concept is necessary. Shannon's concept of information is sufficient for quantum information theory. Properties that are cited to contrast quantum information (...) and classical information (i.e., Shannon information) actually point to differences in our ability to manipulate, access, and transfer information depending on whether quantum systems, opposed to classical systems, are used in a communication system. I also demonstrate that conceptually puzzling phenomena in quantum information theory, such as dense coding, teleportation, and Schumacher coding, all of which are cited as evidence that a new concept of information is required, do not have to be regarded as such. (shrink)