The formation of particles of elemental tin in association with the nucleation of the precipitate phase θ′ in an Al–1.7 at.% Cu–0.01 at.% Sn alloy has been investigated by high resolution transmission electron microscopy. Analysis of lattice images has demonstrated that these tin particles associated with θ′ platelets formed during short-term ageing (typically 3 min at 200 degrees Celcius) exhibit a crystallographic form that is distinctly different from that previously reported in such ternary alloys and also from that observed in (...) the binary alloy Al–0.01 at.% Sn. Those tin particles that could be clearly identified as β-Sn phase shared a crystallographic relationship of the form (001)Sn‖(001)Al‖(001)θ′, [110]Sn‖[100]Al‖[100]θ′ with the α-Al and θ′ phases with which they were simultaneously in contact. The observations imply that, while tin may assist nucleation of platelets of θ′, the formation of θ′ equally influences the crystallography of β--Sn that forms in association with θ′. Following prolonged ageing (typically 50 h at 200°C), the β-Sn particles in contact with θ′ plates had coarsened and diminished in number, and most now exhibited an orientation relationship with α-Al matrix similar to that observed in the binary alloy Al–0.01 at.% Sn (i.e. (100)Sn‖(111)Al, [010]Sn‖[112]Al) and to that previously observed in the later stages of ageing of the ternary alloy Al–1.7 at.% Cu–0.01 at.% Sn. (shrink)

Voluntary stream segregation was investigated in cochlear implant users and normal-hearing listeners using a segregation-promoting objective approach which evaluated the role of spectral and amplitude-modulation rate separations on stream segregation and its build-up. Sequences of 9 or 3 pairs of A and B narrowband noise bursts were presented which differed in either center frequency of the noise band, the AM-rate, or both. In some sequences, the last B burst was delayed by 35 ms from their otherwise-steady temporal position. In the (...) other sequences, the last B bursts were temporally advanced from 0 to 10 ms. A single interval yes/no procedure was utilized to measure participants’ sensitivity in identifying delayed vs. no-delay sequences. A higher d′ value showed the higher ability to segregate the A and B subsequences. For NH listeners, performance improved with each spectral separation. However, for CI users, performance was only significantly better for the condition with the largest spectral separation. Additionally, performance was significantly poorer for the largest AM-rate separation than for the condition with no AM-rate separation for both groups. The significant effect of sequence duration in both groups indicated that listeners made more improvement with lengthening the duration of stimulus sequences, supporting the build-up effect. The results of this study suggest that CI users are less able than NH listeners to segregate NBN bursts into different auditory streams when they are moderately separated in the spectral domain. Contrary to our hypothesis, our results indicate that AM-rate separation may interfere with the segregation of streams of NBN. Additionally, our results add evidence to the literature that CI users build up stream segregation at a rate comparable to NH listeners, when the inter-stream spectral separations are adequately large. (shrink)

Context: The dominant approach to the study of perception is representational/computational, with an emphasis on the achievements of the brain and the nervous system, which are taken to construct internal models of the world. Alternatives include ecological, embedded, embodied, and enactivist approaches, all of which emphasize the centrality of action in understanding perception. Problem: Despite sharing many theoretical commitments that lead to a rejection of the classical approach, the alternatives are characterized by important contrasts and points of divergence. Here we (...) focus on the enactive and ecological approaches, in particular, on how they construe the status of the environment and the content of perception. Method: We begin with a review of James Gibson’s ecological psychology, highlighting it as a psychology for all organisms not just humans. Against this backdrop, we consider enactivist arguments against direct perception - a central assertion of the ecological approach - and in favor of interpreting the activity of perceptual agents as a kind of construction of a perceptually meaningful world. Results: We assess the merits of this interpretation and we conclude that it cannot be grounded on fundamental principles such as thermodynamics and organism-environment mutuality. Implications: As a consequence, enactivism remains close to representationalism and entails a form of dualism. Constructivist content: We advance a criticism of the constructivist foundations of the enactive approach to perception. Perception-action mutuality at the heart of enactivism does not require mental construction; indeed, perception-action mutuality obviates construction. (shrink)

Let be a recursive structure, and let R be a recursive relation on . Harizanov isolated a syntactical condition which is necessary and sufficient for to have recursive copies in which the image of R is r.e. of arbitrary r.e. degree. We had conjectured that a certain extension of Harizanov's syntactical condition would be necessary and sufficient for to have recursive copies in which the image of R is ∑α0 of arbitrary ∑α0 degree, but this is not the case. Here (...) we give examples illustrating some restrictions on the possible ∑α0 degrees. In these examples, the image of R cannot be ∑α0 of degree d unless d possesses an “α-table”. (shrink)

Much ink has been spilt in consideration of the once pervasive reliance on military metaphors to depict the relationships between science and religion in the nineteenth century. This has resulted in historically sensitive treatments of secularization; and the realization that the relationship between science and religion was not a bloody war between intellectual nation states, but a protracted divorce of former partners. Moreover, historians of science have been encouraged to throw off the yoke of the internalism–externalism debate, and to explore (...) the cultural boundaries that impinged upon practitioners of a natural knowledge of the world. Within the historiography of nineteenth-century science, this has resulted in many new perspectives on science and natural knowledge in relation to cultural control and authority. (shrink)

Roman Catholic moral theology follows a centuries-old tradition of moral reflection. Contemporary Roman Catholic moral theory applies these traditional arguments to the realm of medical ethics, including the issues of active euthanasia and physician-assisted suicide. Unavoidable moral limits on licit medical intervention sometimes require that the moral duty to treat, cede to the duty to cease treatment when measures become more harmful than beneficial to the patient. This does not reduce the need for the compassionate use of palliative care in (...) response to suffering. However, it does mean that rather than being excessively committed to maintaining mere biological human life, or actively seeking death, that we learn a sober realism about the limits of human life. Catholic moral analysis examines an act objectively, both in its relation to the agent and as a material event in the world. This allows both the virtuous or vicious intentions of the agent and the effects of the action to be included in its moral evaluation. Thus, Catholic moral analysis is both quasi-deontological and quasi-consequentialist. Objectively, active euthanasia and physician-assisted suicide, as acts of deliberate killing, are seen as repugnant, in that they fail to incarnate a benign inner intention or to form an agent in virtue. Catholic moral theology is extremely skeptical that an act of intending death directly can be consonant with a sincere compassion for the dying, suffering person and views it as a direct negation of the precious gift of human life. (shrink)

The most important events of the immediately preceding period--1945-1954--were attempts at general readings of Descartes' thought by Jean Laporte, Fernand Alquié, and Martial Guéroult. In Le Rationalisme de Descartes Laporte struck sharply at stereotype by insisting that Descartes was not a rationalist. Deftly exploiting such issues as the soul-body union, the knowledge of the infinite and the faith-reason relationship, he draws the conclusion that "... if it were necessary to characterize Descartes' philosophy by one name, the name which would fit (...) it best, all paradox aside, would be empiricism, radical and integral empiricism." The readings of both Alquié and Gueroult are carefully attuned to the development in Descartes' thought. In La Découverte Métaphysique de l'Homme chez Descartes, the former maintains that this development is dominated by the progressive discovery of the meaning of man. Guéroult takes a remark from the Discourse on Method as key to the unfolding of Descartes' thought. The "long chains of reasons, so simple and easy, which geome- tricians use to arrive at their most difficult demonstrations..." are the central inspiration of Descartes selon l'Ordre des Raisons. Cartesianism, it is maintained, developed primarily by deductive movement along these chains. (shrink)

The article recently published in this journal by Dr B A Rix, a member of the Danish Council of Ethics (DCE), was heavily criticised by Dr David Lamb and Mr Christopher Pallis in subsequent commentaries. The editorial column by Professor Raanan Gillon also criticised the position put forward by Rix. In this article I contend that the definition of death put forward by Pallis and Lamb suffers certain philosophical shortcomings, that the position put forward by Rix deserves fuller consideration, and (...) that Rix is not to be dismissed easily. (shrink)

In 1924, Virginia Woolf wrote a short story based upon the life of Eleanor Ormerod. A wealthy spinster, Ormerod achieved notoriety in late nineteenth-century Britain as an economic entomologist. In 1904, Nature compared her to Caroline Herschel and Mary Somerville. In terms of recent scholarship devoted to the history of women in science, Ormerod's career differed markedly from that of her two predecessors. The emotional or intellectual support of a brother, husband, father, or male family relation made no considerable contribution (...) to her commitment to the study of entomology. Furthermore, her life as an independent spinster offered no positive proof for Francis Power Cobbe's dictum: as she aged, Eleanor Ormerod showed no tendency to become a ‘women's rights woman’. She publicly accepted or internalized the dominant, masculine ideology of science; and by contemporary standards, she achieved success. (shrink)

Heath Robinson could perhaps draw a diagram that made sense of the legislative and regulatory structure Bonnicksen describes in this book. However Heath Robinson machines, no matter how baroque, actually achieve something: in the four years covered by this contemporary history the American “system” seems to have achieved very little. That we have not yet seen a confirmed cloned child produced in the USA or elsewhere does not seem due in any part to the activity that Bonnicksen describes. This is (...) not a history of America’s progress towards crafting a policy; it is an account of its failure to make one.The bulk of this book details the legal and regulatory responses to emerging reproductive technology in America following the announcement of the birth of Dolly the cloned lamb in 1997. The remainder gives an overview of the position of other countries around the world, and a brief concluding chapter outlines the options open to the US in the future. Lest anything that follows might suggest otherwise, I found this book interesting and informative, and …. (shrink)

Le « lieu théologique » qu'est le magistère de l'Eglise s'impose de plus en plus à la réflexion du théologien, du canoniste et, plus largement, de tout catholique averti en raison de documents nombreux et divers émanant du pape et des instances romaines. Tirant ses origines du concept de tradition en référence directe à l'expérience de foi, le Magistère est aussi le produit d'une longue histoire. Dans cette histoire, l'organe transmetteur allait prendre le pas sur la tradition transmise, avec prise (...) en compte de la foi comme obéissance plutôt qu'adhésion et surgissement du concept de « foi ecclésiastique ». Au terme de cette histoire, une question se pose inévitablement : doit-on analyser ces évolutions en terme de dérives ? The « theological site » that is the Church's Magisterium is more and more a subject of reflection for the theologian, the canonist, and, more generally, fur every aware Catholic. This is especially due to the numerous and diverse documents coming from the Pope and other Roman sources. Deriving its origins from the concept of tradition in direct reference to the experience of faith, the Magisterium is also the Product of a long history. In this history the transmitting organ would take ascendancy over received tradition, with an account of the faith as obedience rather than adhesion, and the growth of the concept of « ecclesiastical faith. » At the term of this history a question is inevitably posed : should one analyze these evolutions in terms of going astray ? (shrink)

Taking John Paul II's teaching on the Christian meaning of suffering as my main source for a Catholic perspective on suffering, I show how seriously he takes the reality of suffering, and how seriously he takes the question as to the meaning of suffering. I proceed to explore his many-sided teaching on the way in which sin is and is not involved in the meaning of suffering, giving particular attention to his teaching on social dimensions of sin and suffering that (...) are little understood in the individualistic West today. The heart of his teaching on suffering lies in his explication of how it is that we have to be conformed in our suffering to the suffering of Christ so as to share in His resurrection. But it is not the suffering as such but the love that we are called to live when we suffer, that incorporates us into the risen Christ. (shrink)

Upshot: Gibsonian and enactivist thinkers appear to diverge primarily with respect to the emphasis placed on the contributions of the organism to perception-action. Enactivists claim that a fundamental asymmetry in the organism-environment relationship should be credited for the existence of meaning in the world. Gibsonians counter that theory must reckon with both the asymmetry and symmetry between organism and environment as well as with the role of specificational information in underwriting their coordination.