George Boolos was one of the most prominent and influential logician-philosophers of recent times. This collection, nearly all chosen by Boolos himself shortly before his death, includes thirty papers on set theory, second-order logic, and plural quantifiers; on Frege, Dedekind, Cantor, and Russell; and on miscellaneous topics in logic and proof theory, including three papers on various aspects of the Gödel theorems. Boolos is universally recognized as the leader in the renewed interest in studies of Frege's work on logic and (...) the philosophy of mathematics. John Burgess has provided introductions to each of the three parts of the volume, and also an afterword on Boolos's technical work in provability logic, which is beyond the scope of this volume. (shrink)

Systems biology is a vigorous and expanding discipline, in many ways a successor to genomics and perhaps unprecendented in its combination of biology with a ...

§1. The origins of recursion theory. In dedicating a book to Steve Kleene, I referred to him as the person who made recursion theory into a theory. Recursion theory was begun by Kleene's teacher at Princeton, Alonzo Church, who first defined the class of recursive functions; first maintained that this class was the class of computable functions ; and first used this fact to solve negatively some classical problems on the existence of algorithms. However, it was Kleene who, in his (...) thesis and in his subsequent attempts to convince himself of Church's Thesis, developed a general theory of the behavior of the recursive functions. He continued to develop this theory and extend it to new situations throughout his mathematical career. Indeed, all of the research which he did had a close relationship to recursive functions.Church's Thesis arose in an accidental way. In his investigations of a system of logic which he had invented, Church became interested in a class of functions which he called the λ-definable functions. Initially, Church knew that the successor function and the addition function were λ-definable, but not much else. During 1932, Kleene gradually showed1 that this class of functions was quite extensive; and these results became an important part of his thesis 1935a. (shrink)

This target article draws together two groups of experimental studies on the control of human movement through peripheral feedback and centrally generated signals of motor commands. First, during natural movement, feedback from muscle, joint, and cutaneous afferents changes; in human subjects these changes have reflex and kinesthetic consequences. Recent psychophysical and microneurographic evidence suggests that joint and even cutaneous afferents may have a proprioceptive role. Second, the role of centrally generated motor commands in the control of normal movements and movements (...) following acute and chronic deafferentation is reviewed. There is increasing evidence that subjects can perceive their motor commands under various conditions, but that this is inadequate for normal movement; deficits in motor performance arise when the reliance on proprioceptive feedback is abolished either experimentally or because of pathology. During natural movement, the CNS appears to have access to functionally useful input from a range of peripheral receptors as well as from internally generated command signals. The unanswered questions that remain suggest a number of avenues for further research. (shrink)

In this article, we present results from a literature review of intrinsic, instrumental, and relational values of nature conducted for the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services, as part of the Methodological Assessment of the Diverse Values and Valuations of Nature. We identify the most frequently recurring meanings in the heterogeneous use of different value types and their association with worldviews and other key concepts. From frequent uses, we determine a core meaning for each value type, which is (...) sufficiently inclusive to serve as an umbrella over different understandings in the literature and specific enough to help highlight its difference from the other types of values. Finally, we discuss convergences, overlapping areas, and fuzzy boundaries between different value types to facilitate dialogue, reduce misunderstandings, and improve the methods for valuation of nature's contributions to people, including ecosystem services, to inform policy and direct future research. © 2023 The Author(s). Published by Oxford University Press on behalf of the American Institute of Biological Sciences. (shrink)

A formalism is developed that treats a robot as a subject that can interpret its own experience rather than an object that is interpreted within our experience. A regulative definition of a meaningful experience in robots is proposed in which the present sensible experience is considered meaningful to the agent, as the subject of the experience, if it can be related to the agent's temporal horizons. This definition is validated by demonstrating that such an experience in evolutionary autonomous agents is (...) embodied, contextual and normative, as is required for the maintenance of phenomenological accuracy. With this formalism it is shown how a dialectic similar to that described in Hegelian phenomenology can emerge in the robotic experience and why the presence of such a dialectic can serve as a constraint in the further development of cognitive agents. (shrink)

Features of threatening cues and the associated context influence the perceived imminence of threat and the defensive responses evoked. To provide additional knowledge about how the directionality of a threat (i.e. directed-towards or away from the viewer) might impact defensive responses in humans, participants were shown pictures of a man carrying a gun (threat) or nonlethal object (neutral) directed-away from or towards the participant. Cardiac and electrodermal responses were collected. Compared to neutral images, threatening images depicting a gun directed-towards the (...) participant induced sustained bradycardia and an increased electrodermal response, interpreted as immobility under attack. This defensive immobility reaction is evoked by high perceived threat and inescapable situations and indicates intense action preparation. Pictures of guns directed-away from the participant induced shorter bradycardia and no significant modulation of the electrodermal response compared to neutral pictures, which might be consistent with the perception of a less threatening situation. The results show that the directionality of threat stimuli is a key factor that prompts different patterns of defensive responses. (shrink)

Originally published in 1904, Whittaker’s A Treatise on the Analytical Dynamics of Particles and Rigid Bodies soon became a classic of the subject and has remained in print for most of these 108 years. In this paper, we follow the book as it develops from a report that Whittaker wrote for the British Society for the Advancement of Science to its influence on Dirac’s version of quantum mechanics in the 1920s and beyond.

Unlike its predecessors, this systematic survey of the law of Athens is based on explicit discussion of how the subject might be studies, incorporating topics such as the democratic political system and social structure. Technical and legal terms are explained in a comprehensive glossary.

Objectives: This study aimed to determine attitudinal and self reported behavioural variations between medical students in different years to scenarios involving academic misconduct.Design: A cross-sectional study where students were given an anonymous questionnaire that asked about their attitudes to 14 scenarios describing a fictitious student engaging in acts of academic misconduct and asked them to report their own potential behaviour.Setting: Dundee Medical School.Participants: Undergraduate medical students from all five years of the course.Method: Questionnaire survey.Main measurements: Differences in medical students’ attitudes (...) to the 14 scenarios and their reported potential behaviour with regards to the scenarios in each of the years.Results: For most of the scenarios there was no significant difference in the response between the years. Significant differences in the responses were found for some of the scenarios across the years, where a larger proportion of year one students regarded the scenario as wrong and would not engage in the behaviour, compared to other years. These scenarios included forging signatures, resubmitting work already completed for another part of the course, and falsifying patient information.Conclusion: Observed differences between the years for some scenarios may reflect a change in students’ attitudes and behaviour as they progress though the course. The results may be influenced by the educational experience of the students, both in terms of the learning environment and assessment methods used. These differences may draw attention to the potential but unintentional pressures placed on medical students to engage in academic misconduct. The importance of developing strategies to engender appropriate attitudes and behaviours at the undergraduate level must be recognised. (shrink)

We disagree with Almaatouq et al. that no realistic alternative exists to the “one-at-a-time” paradigm. Seventy years ago, Egon Brunswik introduced representative design, which offers a clear path to commensurability and generality. Almaatouq et al.'s integrative design cannot guarantee the external validity and generalizability of results which is sorely needed, while representative design tackles the problem head on.

Rita Bottino,1 Santosh Nagaraju,2 Vikas Satyananda,2 Hidetaka Hara,2 Martin Wijkstrom,2 Massimo Trucco,1 David KC Cooper2 1Institute of Cellular Therapeutics, Allegheny Health Network, 2Thomas E Starzl Transplantation Institute, Department of Surgery, University of Pittsburgh, Pittsburgh, PA, USA: Diabetes mellitus is increasing worldwide. Type 1 diabetes can be treated successfully by islet allotransplantation, the results of which are steadily improving. However, the number of islets that can be obtained from deceased human donors will never be sufficient to cure more than a very (...) small percentage of patients who might benefit from transplantation. Although there are some differences in glucose metabolism between pigs and humans, the use of pigs could provide an unlimited supply of islets, and the insulin produced would undoubtedly control glucose levels. Transplantation of islets into the portal vein results in islets residing in the liver; however, an early inflammatory response and rejection remain problematic, even when the recipient is receiving immunosuppressive therapy. In the long term, immunosuppressive drugs may exhibit toxicities to patients and specifically harm the islet cells. In contrast, encapsulation techniques provide islets with a physical barrier that prevents antibodies binding to the islet graft while still allowing insulin to be released into the recipient's circulation; in theory, patients receiving encapsulated grafts might not require exogenous immunosuppressive therapy. Nonhuman primates with encapsulated pig islet transplants have remained insulin-independent for several weeks, but long-term efficacy remains uncertain. Furthermore, techniques are now available to knock out genes from the pig and/or insert human genes, thus rendering the antigenic structure of pigs closer to that of humans, and providing protection from the human immune response. Islet transplantation from genetically engineered pigs has been followed by insulin independence in a small number of nonhuman primates for greater than 1 year. Neonatal islets have some advantages over adult islets in that they are easier to isolate and culture, and have the ability to proliferate during the first few months after transplantation. In 2009, the International Xenotransplantation Association set up a group to encourage and advise on clinical trials of pig islet xenotransplantation; this group's guidelines are discussed. Clinical trials of encapsulated pig islets are already under way. Keywords: diabetes, islets, pancreatic, pig, xenotransplantation. (shrink)

Plutarch's essay de fortuna Romanorum has attracted divergent judgements. Ziegler dismissed it as ‘eine nicht weiter ernst zu nehmende rhetorische Stilübung’. By Flacelière it was hailed as ‘une ébauche de méditation sur le prodigieux destin de Rome’. It is time to consider the work afresh and to discover whether there is common ground between these two views. Rather than offering a general appreciation, my treatment will take the work chapter by chapter, considering points of interest as they arise. This method (...) will enable us to compare what Plutarch says on particular subjects and themes in de fort. Rom. with what he says or does not say about them elsewhere. We shall thus be able to see clearly that for the most part the ideas he presents in the essay correspond with his thoughts about the rôle of fortune expressed in more serious writing, and that, where there is no correspondence, this is attributable to the rhetorical background. I do not intend to address directly the frequently discussed but insoluble question of whether we have in de fort. Rom. only one of two original works, that is whether there was once a de virtute Romanorum which Plutarch composed or answered. De fort. Rom. itself in fact gives almost as much prominence to άρετή as to τúχη, and their competing roles will be carefully evaluated. Nor do I look at the dating of the work. (shrink)