For a centerless group G, we can define its automorphism tower. We define G α : G 0 = G, G α+1 = Aut(G α ) and for limit ordinals ${G^{\delta}=\bigcup_{\alpha<\delta}G^{\alpha}}$ . Let τ G be the ordinal when the sequence stabilizes. Thomas’ celebrated theorem says ${\tau_{G}<(2^{|G|})^{+}}$ and more. If we consider Thomas’ proof too set theoretical (using Fodor’s lemma), we have here a more direct proof with little set theory. However, set theoretically we get a parallel theorem (...) without the Axiom of Choice. Moreover, we give a descriptive set theoretic approach for calculating an upper bound for τ G for all countable groups G (better than the one an analysis of Thomas’ proof gives). We attach to every element in G α , the αth member of the automorphism tower of G, a unique quantifier free type over G (which is a set of words from ${G*\langle x\rangle}$ ). This situation is generalized by defining “(G, A) is a special pair”. (shrink)

If G is a centreless group, then τ denotes the height of the automorphism tower of G. We prove that it is consistent that for every cardinal λ and every ordinal α<λ, there exists a centreless group G such that τ=α; and if β is any ordinal such that 1β<λ, then there exists a notion of forcing , which preserves cofinalities and cardinalities, such that τ=β in the corresponding generic extension.

We prove that there are groups in the constructible universe whose automorphism towers are highly malleable by forcing. This is a consequence of the fact that, under a suitable diamond hypothesis, there are sufficiently many highly rigid non-isomorphic Souslin trees whose isomorphism relation can be precisely controlled by forcing.

We extend the results of Hamkins and Thomas concerning the malleability of automorphism tower heights of groups by forcing. We show that any reasonable sequence of ordinals can be realized as the automorphism tower heights of a certain group in consecutive forcing extensions or ground models, as desired. For example, it is possible to increase the height of the automorphism tower by passing to a forcing extension, then increase it further by passing to a (...) ground model, and then decrease it by passing to a further forcing extension, and so on, transfinitely. We make sense of the limit models occurring in such a sequence of models. At limit stages, the automorphism tower height will always be 1. (shrink)

There are many debates about what constitutes a utopia. Are utopias benign or dangerous? Is the idea of utopianism essential to Christianity or heretical?

Originally published in 1910, this book attempts to describe knowledge from the point of view of a philosophical psychology. Wodehouse treats the text as a 'psychological preface to metaphysics', and splits her examination into three sections: knowledge as resulting from judgements in the actual world; the philosophical problem of fallible knowledge; and the question of imagination and 'the variousness of reality'. This book will be of value to anyone with an interest in Wodehouse's work or in the overlap of psychology (...) and philosophy. (shrink)

The complete sequencing of the genome of the fruit fly Drosophila melanogaster offers the prospect of detailed functional analysis of the extensive gene families in this genetic model organism. Comprehensive functional analysis of family members is facilitated by access to a robust, stable and inducible expression system in a fly cell line. Here we show how the Schneider S2 cell line, derived from the Drosophila embryo, provides such an expression system, with the bonus that radioligand binding studies, second messenger assays, (...) ion imaging, patch‐clamp electrophysiology and gene silencing can readily be applied. Drosophila is also ideal for the study of new control strategies for insect pests since the receptors and ion channels that many new animal health drugs and crop protection chemicals target can be expressed in this cell line. In addition, many useful orthologues of human disease genes are emerging from the Drosophila genome and the study of their functions and interactions is another area for postgenome applications of S2 cell lines. BioEssays 24:1066–1073, 2002. © 2002 Wiley‐Periodicals, Inc. (shrink)

Genetic analysis of Drosophil has provided evidence in support of two proposed evolutionary genetic mechanisms of aging: mutation accumulation and antagonistic pleiotropy. Both mechanisms result from the lack of natural selection acting on old organisms. Analyses of large numbers of flies have revealed that mortality rates do not continue to rise with age as previously thought, but plateau at advanced ages. This phenomenon has implications both for models and for definitions of aging, and may be explained by the evolutionary theories. (...) The physiological processes and genes most relevant to aging are being identified using Drosophila lines selected in the laboratory for postponed senescence. Oxidative stress and insufficient metabolic reserves/capacity may be particularly important factors in limiting the fruitfly lifespan. Genes which exhibit aging‐related changes in expression are now being identified. Transgenic flies are being used to analyze the mechanisms of such aging‐related gene expression, and to test the effects of specific genes on aging and aging‐related deterioration. (shrink)

Outsider mission workers with local church communities, such as with the agency Latin Link, can have a role in the promotion of church and community-based income generation projects as a poverty reduction strategy and as a way of healthy community involvement generally. This is likely to involve a process of healthy community decision-making, some generic business training for potential project leaders and workers, and a microfinance scheme run with established guidelines. In this way, outside initiative promotes community development rather than (...) imposing unsuitable solutions from the outside. (shrink)

Throughout the scientific age it has been increasingly realised that the path to knowledge is through carefully-controlled experimentation. Medicine must never, however, treat human beings as objects, or as the means to achieving increased knowledge. Ultimately the goal of human evolution will be served by the willing collaboration of members of society in the advancement of knowledge through carefully planned experimentation. As of now, however, many safeguards must be built into the system to ensure that no exploitation occurs. Experimenters are (...) charged with the task of designing the most ingenious experiments, to give maximum information with a minimum of trauma and always to ensure the fully informed consent of the participants. This paper was read to a conference on human rights in relation to forensic science organised by Centro Internazionale di Richerche e Studi Penale e Penitanziari, in cooperation with UNESCO, held in Messina, Italy, in March 1980. (shrink)

Résumé Même si les utopies sont potentiellement dangereuses, les visions utopiques nous sont malgré tout indispensables. La perte de l’espoir et de l’utopie signifie la perte de l’humanité. Mais comment empêcher l’utopie de tourner en dystopie? L’utopie pensée en termes de perfection, de pureté et d’exclusivité impose sa version d’une vie meilleure comme la seule et unique. L’utopisme d’opposition par contre ne cherche ni la perfection, ni la suppression des possibilités d’évolution. Son objectif est le progrès et non pas la (...) répression de l’homme. Ce n’est pas l’utopisme qui est défectueux, le problème vient davantage de la conviction qu’une utopie particulière puisse faire advenir la seule façon correcte de vivre. (shrink)

The explosion of data grows at a rate of roughly five trillion bits a second, giving rise to greater urgency in conceptualizing the infosphere and understanding its implications for knowledge and public policy. Philosophers of technology and information technologists alike who wrestle with ontological and epistemological questions of digital information tend to emphasize, as Floridi does, information as our new ecosystem and human beings as interconnected informational organisms, inforgs at home in ambient intelligence. But the linguistic and conceptual representations of (...) Big Data—the massive volume of both structured and unstructured data—and the real world practice of data-mining for patterns and meaningful interpretation of evidence reveal tension and ambiguity in the bold promise of data analytics. This paper explores the tacit epistemology of the rhetoric and representation of Big Data and suggests a richer account of its ambiguities and the paradox of its real world materiality. We argue that Big Data should be recognized as manifesting multiple and conflicting trajectories that reflect human intentionality and particular patterns of power and authority. Such patterns require attentive exploration and moral appraisal if we are to resist simplistic informationist ontologies of Big Data, and the subtle forms of control in the political ecology of Big Data that undermine its promise as transformational knowledge. (shrink)

This is the first comprehensive volume to offer a state of the art investigation both of the nature of political ideologies and of their main manifestations. The diversity of ideology studies is represented by a mixture of the range of theories that illuminate the field, combined with an appreciation of the changing complexity of concrete ideologies and the emergence of new ones. Ideologies, however, are always with us.

ObjectivesIn 2015, the Province of Quebec, Canada passed a law that allowed voluntary active euthanasia. Palliative care stakeholders in Canada have been largely opposed to euthanasia, yet there is little research about their views. The research question guiding this study was the following: How do palliative care physicians in Quebec position themselves regarding the practice of VAE in the context of the new provincial legislation?MethodsWe used interpretive description, an inductive methodology to answer research questions about clinical practice. A total of (...) 18 palliative care physicians participated in semistructured interviews at two university-affiliated hospitals in Quebec.ResultsParticipants positioned themselves in opposition to euthanasia. Their justifications were framed within their professional commitment to not hasten death, which sat in tension with the value of patients’ autonomy to choose how to die. Participants described VAE as unacceptable if it impeded opportunities to evaluate and alleviate suffering. Further, they contested government rhetoric that positioned VAE as a way to improve end-of-life care. Participants felt that VAE would diminish the potential of palliative care to relieve suffering. Dilemmas were apparent in their narratives, about reconciling respect for patient autonomy with broader palliative care values, and the value of accompanying and not abandoning patients who make requests for VAE while being committed to neither prolonging nor hastening death.ConclusionsThis study provides insight into nuanced positions of experienced palliative care physicians in Quebec and confirms expected tensions between an important stakeholder and the practice of VAE as guided by the new legislation. (shrink)

We investigate various strong notions of rigidity for Souslin trees, separating them under ♢ into a hierarchy. Applying our methods to the automorphism tower problem in group theory, we show under ♢ that there is a group whose automorphism tower is highly malleable by forcing.