7,917 research outputs found

    Libertas philosophandi and Freedom of Mind in Spinoza’s Tractatus Theologico-politicus

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    Isaiah Berlin famously distinguished between “negative” and “positive” liberty, arguing that in practice the two are often in tension with each other. This paper uses Berlin’s distinction to analyze Spinoza’s discussion of freedom in the Tractatus Theologico-Politicus. Libertas philosophandi is Spinoza’s shorthand for freedom of thought and expression – an important element in traditional liberal (“negative”) freedom. The TTP (as its subtitle announces) is devoted in great part to defending the value and importance of permitting such freedom in the state. But as commentators have often noted, Spinoza is reluctant to extend this liberty to the clerics of his day. I argue that this is best understood by reference to a more “positive” conception of freedom that also appears (in less conspicuous passages) in the TTP. This more positive conception, familiar from the Ethics, explains and justifies the liberty-limiting restrictions placed on religious agents and institutions

    Multivariate Design of Experiments for Engineering Dimensional Analysis

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    We consider the design of dimensional analysis experiments when there is more than a single response. We first give a brief overview of dimensional analysis experiments and the dimensional analysis (DA) procedure. The validity of the DA method for univariate responses was established by the Buckingham Π\Pi-Theorem in the early 20th century. We extend the theorem to the multivariate case, develop basic criteria for multivariate design of DA and give guidelines for design construction. Finally, we illustrate the construction of designs for DA experiments for an example involving the design of a heat exchanger

    An Improved Holding Chamber for the Measurement of Oxygen Consumption in Mice

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    An apparatus is described which has been useful in classroom demonstrations and for research in metabolic studies of mice. The unique feature of this modification of basic metabolators is a standard taper ground glass joint

    Oncogenic K-Ras suppresses IP<sub>3</sub>-dependent Ca<sup>2+</sup> release through remodeling of IP<sub>3</sub>Rs isoform composition and ER luminal Ca<sup>2+</sup> levels in colorectal cancer cell lines

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    The GTPase Ras is a molecular switch engaged downstream of G-protein coupled receptors and receptor tyrosine inases that controls multiple cell fate-determining signalling athways. Ras signalling is frequently deregulated in cancer underlying associated changes in cell phenotype. Although Ca2+ signalling pathways control some overlapping functions with Ras, and altered Ca2+ signalling pathways are emerging as important players in oncogenic transformation, how Ca2+ signalling is remodelled during transformation and whether it has a causal role remains unclear. We have investigated Ca2+ signalling in two human colorectal cancer cell lines and their isogenic derivatives in which the mutated K-Ras allele (G13D) has been deleted by homologous recombination. We show that agonist-induced Ca2+ release from intracellular stores is enhanced by loss of K-RasG13D through an increase in the ER store content and a modification of IP3R subtype abundance. Consistently, uptake of Ca2+ into mitochondria and sensitivity to apoptosis was enhanced as a result of KRasG13D loss. These results suggest that suppression of Ca2+ signalling is a common response to naturally occurring levels of K-RasG13D that contributes to a survival advantage during oncogenic transformation

    Value Assumptions Underlying Evaluation Research

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    Phase Transitions in a Dusty Plasma with Two Distinct Particle Sizes

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    In semiconductor manufacturing, contamination due to particulates significantly decreases the yield and quality of device fabrication, therefore increasing the cost of production. Dust particle clouds can be found in almost all plasma processing environments including both plasma etching devices and in plasma deposition processes. Dust particles suspended within such plasmas will acquire an electric charge from collisions with free electrons in the plasma. If the ratio of inter-particle potential energy to the average kinetic energy is sufficient, the particles will form either a liquid structure with short range ordering or a crystalline structure with long range ordering. Otherwise, the dust particle system will remain in a gaseous state. Many experiments have been conducted over the past decade on such colloidal plasmas to discover the character of the systems formed, but more work is needed to fully understand these structures. The preponderance of previous experiments used monodisperse spheres to form complex plasma systems

    Can a combination of the conformal thin-sandwich and puncture methods yield binary black hole solutions in quasi-equilibrium?

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    We consider combining two important methods for constructing quasi-equilibrium initial data for binary black holes: the conformal thin-sandwich formalism and the puncture method. The former seeks to enforce stationarity in the conformal three-metric and the latter attempts to avoid internal boundaries, like minimal surfaces or apparent horizons. We show that these two methods make partially conflicting requirements on the boundary conditions that determine the time slices. In particular, it does not seem possible to construct slices that are quasi-stationary and avoid physical singularities and simultaneously are connected by an everywhere positive lapse function, a condition which must obtain if internal boundaries are to be avoided. Some relaxation of these conflicting requirements may yield a soluble system, but some of the advantages that were sought in combining these approaches will be lost.Comment: 8 pages, LaTeX2e, 2 postscript figure

    Regulating Gun Markets

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