Quantum mechanical measurements on a physical system are represented by observables - Hermitian operators on the state space of the observed system. It is an important question whether all observables may be realized, in principle, as measurements on a physical system. Dirac’s influential text ( [1], page 37) makes the following assertion on the question: The question now presents itself – Can every observable be measured? The answer theoretically is yes. In practice it may be very awkward, or perhaps even (...) beyond the ingenuity of the experimenter, to devise an apparatus which could measure some particular observable, but the theory always allows one to imagine that the measurement can be made. This Letter re-examines the question of whether it is possible, even in principle, to measure every quantum mechanical observable. Unexpectedly, ideas from com-. (shrink)

The considerable attention to financial interests in clinical research has focused mostly on academic medical centers, even though the majority of clinical research is conducted in community practice settings. To fill this gap, this article maps the practices and policies in 73 community hospitals and several hundred specialized facilities around the country for reviewing clinical investigators’ financial relationships with research sponsors. Community hospitals face a substantially different mix of issues than academic medical centers do because their physician researchers are usually (...) not employees, and more of their studies are later-phase, multicenter trials. Accordingly, community physicians stand to benefit personally from per capita payments, but they tend to have less direct influence over research findings when compared with their academic peers. These and other contrasts require separate guidance for community-based organizations that takes into account their particular needs, circumstances, and institutional capacities. (shrink)

The second highest level of the divided line in Plato’s Republic (510b-511a) appears to be about the entities of mathematics—entities such as particular (though non-physical) triangles. It differs from the highest level in two respects. It involves reasoning from hypotheses, and it uses visible images. This article defends the traditional view that the passage is indeed about these mathematical ‘intermediates’; and tries to show how the apparently different features of the second level are related, by focussing on Plato’s need to (...) give an account of how we can speak of many particulars of the same kind, without assuming that they are imperfect copies, in the way sensible things can be imperfect copies, of forms. (shrink)

We suggest an equilibrium concept for a strategic model with a large number of players in which each player observes the actions of only a small number of the other players. The concept fits well situations in which each player treats his sample as a prediction of the distribution of actions in the entire population, and responds optimally to this prediction. We apply the concept to a strategic voting model and investigate the conditions under which a centrist candidate can win (...) the popular vote although his strength in the population is smaller than the strengths of the right and left candidates.  2003 Elsevier Inc. All rights reserved. (shrink)

A detailed attempt to ground the topological properties of time in the laws of micro- and macro-physical processes. The reversible processes of mechanics are used to define an order among temporally separated events, which is invariant under reversals of time direction. So long as consideration is limited to a single isolated system, a time ensemble, the transfer of the reversibility of the constituent processes of such a system to the system as a whole makes it impossible to define time direction (...) by means of the entropy curve. The directionality of time, accordingly, can only be defined as the direction of the entropy increase of multiple systems, of a space ensemble. A macrostatistical definition of time direction is then based upon the causal relation. The author's view of causation is non-deterministic: the conjunction of two events is caused if they occur together more frequently than can be expected from their chance coincidence. Reichenbach's analyses and arguments are careful and thorough; the book as a whole is a solid achievement. -- M. F. (shrink)

There is a theistic argument which is discussed at least twice in the Hume corpus, both times rather perfunctorily. This perfunctoriness has carried over to some of his commentators, who are not always clear as to what the argument is or about the force of Hume’s comments on it. On page 23 of A Letter from a Gentleman to his Friend in Edinburgh Hume calls it “the metaphysical Argument a priori” and in Part 9 of Dialogues concerning Natural Religion simply (...) “the argument a priori”.1 It is the argument of Demea. (shrink)

Do the various forms of literary theory - deconstruction, Marxism, new historicism, feminism, post-colonialism, and cultural/digital studies - have anything in common? If so, what are the fundamental principles of theory? What is its ideological orientation? Can it still be of use to us in understanding basic intellectual and ethical dilemmas of our time? These questions continue to perplex both students and teachers of literary theory. Habib finds the answers in theory's largely unacknowledged roots in the thought of German philosopher (...) Hegel. Hegel's insights continue to frame the very terms of theory to this day. Habib explains Hegel's complex ideas and how they have percolated through the intellectual history of the last century. This book will interest teachers and students of literature, literary theory and the history of ideas, illuminating how our modern world came into being, and how we can better understand the salient issues of our own time. (shrink)

What can the actions of stockbreeders, as they select the best individuals for breeding, teach us about how new species of wild animals and plants come into being? Charles Darwin raised this question in his famous, even notorious, Origin of Species (1859). Darwin's answer - his argument by analogy from artificial to natural selection - is the subject of our book. We aim to clarify what kind of argument it is, how it works, and why Darwin gave it such prominence. (...) As we explain more fully in our Introduction, we believe that the argument becomes much more intelligible when set, contextually, in a story stretching from classical Greek mathematics to modern evolutionary genetics: a long story, and a broad one too, encompassing everything from Darwin's earliest notebook theorising on the births and deaths of species, to agrarian capitalism as a distinctive form of economic life, to shifting Western reflections on art-nature relations. (shrink)

Este volume resume as palestras apresentadas durante o simpósio comemorativo dos "100 Anos da Física Quântica", realizado no Instituto de Física da USP. Para avaliar o significado dessa comemoração, basta lembrar que a Física no século XIX parecia estar completa. Os textos agrupados neste volume tratam de aspectos históricos associados à emergência inicial da teoria quântica, de desenvolvimentos relacionados com algumas das suas mais notórias conseqüências, e de aplicações abrangendo fenômenos desde a escala sub-atômica, atômica e molecular, até as dimensões (...) do universo como um todo. (shrink)

Juan B. Justo en la historia y el pensamiento argentinos, por A. Solari.--Teoría y práctica de la historia, por M. H. Alberti.--La base biológica de la historia, por F. Escardó.--La técnica, por A. Justo.--La economía, por R. Bogliolo.--La guerra, por A. G. Rodríguez.--La política, por A. Ghioldi.--La lucha de ciases, por R. Mondolfo.--El salariado, por M. Palacín.--Las formas típicas del privilegio, por J. L. Pena.--El gremialismo proletario, por E. Frugoni.--La cooperación libre, por N. Repetto.--La democracia obrera, por L. Pan.--La religión, (...) la cilencia, el arte, por R. Rivière. (shrink)