The preparation of layers of amorphous Se by plasma-enhanced CVD using the hydride H2Se as precursor gas is described. Information concerning the structure of the films was obtained from Raman spectroscopy. The spectra of amorphous Se indicated that the dominant molecular structure is the eight-membered ring and/or a chain with Se8 molecular fragments. This material exhibited reversible photodarkening when illuminated at 77 K. In order to explain this phenomenon, we propose a mechanism which takes into account the role of the (...) lone-pair electron orbitals of Se in their contribution to structural ordering. Illumination can cause a distortion in the normal bonding direction between nearest-neighbour Se atoms and induce in this way intrinsic defect states located at the band edges. In the photo-darkened state, optical transition will occur between these defect states. (shrink)

In contemporary medical ethics health is rarely acknowledged to be an ethical obligation. This oversight is due to the preoccupation of most bioethicists with a rationalist, contract model for ethics in which moral obligation is limited to truth-telling and promise-keeping. Such an ethics is poorly suited to medicine because it fails to appreciate that medicine's basis as a moral enterprise is oriented towards health values. A naturalistic model for medical ethics is proposed which builds upon biological and medical values. This (...) perspective clarifies ethical obligations to ourselves and to others for life and health. It provides a normative framework for the doctor-patient relationship within which to formulate medical advice and by which to evaluate patient choice. (shrink)

Chalmers (2018) maintains that even if we understood every physical process in the brain we could still wonder why these processes give rise to conscious experience. The meta-problem is the challenge of explaining why we think this 'hard problem' exists. This response to the target paper endorses illusionist accounts of three 'problem intuitions' about consciousness: duality, presentation, and revelation. Subject–object duality is explained in terms of a clash between two compelling but contradictory convictions about consciousness. Phenomenal presence is understood in (...) relation to the configurational features of sensory experiences. And intuitions of revelation are explained as due to an unfounded belief in introspective ontological access. These illusionist analyses are used to bolster the case for physicalist realism rather than to support 'strong' illusionism. In addition to addressing the meta-problem they suggest a promising approach to the hard problem as wel. (shrink)

Daniel Dennett and others have suggested that qualia and introspectible phenomena do not exist. Dennett's account of consciousness, along with several related approaches, has been called illusionism by Keith Frankish. Frankish's analysis is helpful and provocative. As currently presented, however, his 'strong' version of illusionism suffers from several basic confusions, particularly regarding its relationship to eliminative materialism. This paper contrasts strong illusionism with an alternative that is easier to understand and more sharply focused -- fallibilist experiential realism, or, less technically, (...) modest realism. Fallibilist realism affirms the existence of experiential states that are commonly considered qualitative and phenomenal, but shares Frankish's agenda of thoroughly re-evaluating our judgments about such experiences. To illustrate the advantages of modest realism, I compare the ways illusionism and modest realism address two challenging puzzles: explaining how qualitative differences among sensory experiences could be constituted by differences among neural states, and explaining how neural states could constitute any conscious experiences whatsoever. (shrink)

Mutagenesis makes it possible to examine the effect of amino acid replacements on the folding and stability of proteins. The evaluation of kinetic and equilibrium folding data using reaction coordinate diagrams allows one to determine the roles that single amino acids play in the folding mechanism.

This invaluable resource is the first one-volume, in-depth, comprehensive history of modern science ever published.

pt. 1. De dicto: Necessary and contingent truths, by G. W. Leibniz. New essays concerning human understanding, by G. W. Leibniz. Introduction to the critique of pure reason, by Immanuel Kant. On the nature of mathematical truth, C. G. Hempel. Two dogmas of empiricism, by W. V. O. Quine. In defense of a dogma, by H. P. Grace and P. F. Strawson. The a priori and the analytic, by A. Quinton. The truths of reason, by R. Chisholm.--pt. 2. De re: (...) Reference and modality, by W. V. O. Quine. De re et de dicto, by A. Plantinga. World and essence, by A. Plantinga.--Bibliography (p. 200-202). (shrink)

The argument of the Transcendental Deduction of the Categories in the Critique of Pure Reason is the deepest and most far-reaching in philosophy. In his new book, Robert Howell interprets main themes of the Deduction using ideas from contemporary philosophy and intensional logic, thereby providing a keener grasp of Kant's many subtleties than has hitherto been available. No other work pursues Kant's argument through every twist and turn with the careful, logically detailed attention maintained here. Surprising new accounts of apperception, (...) the concept of an object, the logical functions of thought, the role of the Metaphysical Deduction, and Kant's relations to his Aristotelian-Cartesian background are developed. Howell makes a precise contribution to the discussion of most of the disputed issues in the history of Deduction interpretation. Controversial in its conclusions, this book demands the attention of all who take seriously the task of understanding Kant's work and evaluating it dispassionately. (shrink)