We prove new results on common cause closedness of quantum probability spaces, where by a quantum probability space is meant the projection lattice of a non-commutative von Neumann algebra together with a countably additive probability measure on the lattice. Common cause closedness is the feature that for every correlation between a pair of commuting projections there exists in the lattice a third projection commuting with both of the correlated projections and which is a Reichenbachian common cause of the correlation. The (...) main result we prove is that a quantum probability space is common cause closed if and only if it has at most one measure theoretic atom. This result improves earlier ones published in . The result is discussed from the perspective of status of the Common Cause Principle. Open problems on common cause closedness of general probability spaces are formulated, where L is an orthomodular bounded lattice and ϕ is a probability measure on L. (shrink)
No-cloning theorem says that there is no unitary operation that makes perfect clones of non-orthogonal quantum states. The objective of the present paper is to examine whether an imperfect cloning operation exists or not in a C*-algebraic framework. We define a universal \ -imperfect cloning operation which tolerates a finite loss \ of fidelity in the cloned state, and show that an individual system’s algebra of observables is abelian if and only if there is a universal \ -imperfect cloning operation (...) in the case where the loss of fidelity is less than \ . Therefore in this case no universal \ -imperfect cloning operation is possible in algebraic quantum theory. (shrink)
A mathematical rigorous definition of EPR states has been introduced by Arens and Varadarajan for finite dimensional systems, and extended by Werner to general systems. In the present paper we follow a definition of EPR states due to Werner. Then we show that an EPR state for incommensurable pairs is Bell correlated, and that the set of EPR states for incommensurable pairs is norm dense between two strictly space-like separated regions in algebraic quantum field theory.
Halvorson and Clifton have given a mathematical reconstruction of Bohr’s reply to Einstein, Podolsky and Rosen (EPR), and argued that this reply is dictated by the two requirements of classicality and objectivity for the description of experimental data, by proving consistency between their objectivity requirement and a contextualized version of the EPR reality criterion which had been introduced by Howard in his earlier analysis of Bohr’s reply. In the present paper, we generalize the above consistency theorem, with a rather elementary (...) proof, to a general formulation of EPR states applicable to both non-relativistic quantum mechanics and algebraic quantum field theory; and we clarify the elements of reality in EPR states in terms of Bohr’s requirements of classicality and objectivity, in a general formulation of algebraic quantum theory. (shrink)
LTP is thought to be an experimental model for studying the cellular mechanism of learning and memory. Shors & Matzel review some contradictory data concerning the linkage between LTP and memory and suggest that LTP does not underlie learning and memory. LTP is a cellular and synaptic process and cannot be a memory mechanism. In fact, it is a cellular information storage mechanism.
(1999). Sponsorship, academic independence and critical engagement: A forum on shell, the Ogoni dispute and the royal geographical society (with the institute of British geographers) Philosophy & Geography: Vol. 2, No. 2, pp. 254-256.
Long before the origins of agriculture human ancestors had expanded across the globe into an immense variety of environments, from Australian deserts to Siberian tundra. Survival in these environments did not principally depend on genetic adaptations, but instead on evolved learning strategies that permitted the assembly of locally adaptive behavioral repertoires. To develop hypotheses about these learning strategies, we have modeled the evolution of learning strategies to assess what conditions and constraints favor which kinds of strategies. To build on prior (...) work, we focus on clarifying how spatial variability, temporal variability, and the number of cultural traits influence the evolution of four types of strategies: (1) individual learning, (2) unbiased social learning, (3) payoff-biased social learning, and (4) conformist transmission. Using a combination of analytic and simulation methods, we show that spatial—but not temporal—variation strongly favors the emergence of conformist transmission. This effect intensifies when migration rates are relatively high and individual learning is costly. We also show that increasing the number of cultural traits above two favors the evolution of conformist transmission, which suggests that the assumption of only two traits in many models has been conservative. We close by discussing how (1) spatial variability represents only one way of introducing the low-level, nonadaptive phenotypic trait variation that so favors conformist transmission, the other obvious way being learning errors, and (2) our findings apply to the evolution of conformist transmission in social interactions. Throughout we emphasize how our models generate empirical predictions suitable for laboratory testing. (shrink)
EurepGAP is a pioneering field level food safety protocol called ‘good agricultural practices’ currently exercising influence over the global food quality assurance system. Developed by a consortium of major European retailers, this private standard enforces codes of conduct that address issues of health and safety for producers and consumers, as well as working conditions and environmental management on the farmland. Despite various merits and benefits that the standard is premised to offer, the institutional design gives a financial edge to powerful (...) large farms and exporters while diminishing opportunities for smaller growers and exporters to remain in the profitable agricultural export sector of the Global South. This paper explores the institutional origin and evolution of EurepGAP, discusses entry barriers and risks that EurepGAP imposes on the global value chain stakeholders, as well as the ethical implications from broader theoretical perspectives. Subsequently, it examines the evolving nature of a new trend in the fresh fruit and vegetable sector, i.e., the rise of public GAP standards. Promoted by some governments in the Global South, these GAP standards emphasize support for horizontal partnerships among value chain stakeholders, farmer participation, and less capital-intensive agricultural innovations. The paper argues that, within certain limitations, these GAP standards have the potential to be the major alternative GAP approach by encouraging a much broader inclusion of small-scale producers towards the attainment of various social, economic, and environmental benefits. (shrink)
How can Euler diagrams support non-consequence inferences? Although an inference to non-consequence, in which people are asked to judge whether no valid conclusion can be drawn from the given premises, is one of the two sides of logical inference, it has received remarkably little attention in research on human diagrammatic reasoning; how diagrams are really manipulated for such inferences remains unclear. We hypothesized that people naturally make these inferences by enumerating possible diagrams, based on the logical notion of self-consistency, in (...) which every Euler diagram is true in a set-theoretical interpretation. The work is divided into three parts, each exploring a particular condition or scenario. In condition 1, we asked participants to directly manipulate diagrams with size-fixed circles as they solved syllogistic tasks, with the result that more reasoners used the enumeration strategy. In condition 2, another type of size-fixed diagram was used. The diagram layout change interfered with accurate task performances and with the use of the enumeration strategy; however, the enumeration strategy was still dominant for those who could correctly perform the tasks. In condition 3, we used size-scalable diagrams, which reduced the interfering effect of diagram layout and enhanced participants’ selection of the enumeration strategy. These results provide evidence that non-consequence inferences can be achieved by diagram enumeration, exploiting the self-consistency of Euler diagrams. An alternate strategy based on counter-example construction with Euler diagrams, as well as effects of diagram layout in inferential processes, are also discussed. (shrink)
Waddington’s experiments on genetic assimilation showed that selection on environmentally induced phenotypic variants can cause inherited evolutionary changes in the phenotype. We have recently extended this work by demonstrating that it is possible to select for a polyphenism in a monophenic species . We found that a mutation in the juvenile hormone regulatory pathway in Manduca sexta enabled heat stress to reveal a hidden reaction norm of larval coloration. Artificial selection for increased color change in response to heat-shock resulted in (...) the genetic accommodation of a black/green larval color polyphenism, caused by an environment-sensitive threshold switch mediated by the endocrine system. (shrink)
In his later polemical work against Eberhard, Kant uses the concept of “original acquisition” to defend the critical meaning of his own concept of the “a priori”. It is well known that the former has been borrowed from the modern idea of natural law. In this paper, I try to clarify how the former characterizes the latter in Kant's critical epistemology, referring to a certain Kantian transformation of the traditional concept of “innate”. Drawing on the dualism of human cognitive faculties, (...) i.e. of sensibility and understanding, the conception of “original acquisition” can distinguish the apriority of the transcendental imagination from the rest of the a priori apparatus. Thus the concept of “original acquisition” points to one of the central theses in the first Critique. (shrink)