Background Scientific and technological advancements in mapping and understanding the interrelated pathways through which biological and environmental exposures affect disease development create new possibilities for detecting disease risk factors. Early detection of such risk factors may help prevent disease onset or moderate the disease course, thereby decreasing associated disease burden, morbidity, and mortality. However, the ethical implications of screening for disease risk factors are unclear and the current literature provides a fragmented and case-by-case picture. Methods To identify key ethical considerations (...) arising from the early detection of disease risk factors, we performed a systematic scoping review. The Scopus, Embase, and Philosopher’s Index databases were searched for peer-reviewed, academic records, which were included if they were written in English or Dutch and concerned the ethics of (1) early detection of (2) disease risk factors for (3) disease caused by environmental factors or gene-environment interactions. All records were reviewed independently by at least two researchers. Results After screening 2034 titles and abstracts, and 112 full papers, 55 articles were included in the thematic synthesis of the results. We identified eight common ethical themes: (1) Reliability and uncertainty in early detection, (2) autonomy, (3) privacy, (4) beneficence and non-maleficence, (5) downstream burdens on others, (6) responsibility, (7) justice, and (8) medicalization and conceptual disruption. We identified several gaps in the literature, including a relative scarcity of research on ethical considerations associated with environmental preventive health interventions, a dearth of practical suggestions on how to address expressed concerns about overestimating health capacities, and a lack of insights into preventing undue attribution of health responsibility to individuals. Conclusions The ethical concerns arising with the early detection of risk factors are often interrelated and complex. Comprehensive ethical analyses are needed that are better embedded in normative frameworks and also assess and weigh the expected benefits of early risk factor detection. Such research is necessary for developing and implementing responsible and fair preventive health policies. (shrink)

Use of presence and instant messaging applications has grown very rapidly recently, not only at home, but also at work. Early studies on the use of PIM applications in the workplace, however, indicate that PIM applications need to be adapted towards the workplace context. In our research, we explore such adaptations, towards place-based presence systems, i.e., presence systems that are not only able to answer people-oriented presence queries such as “Who is online?” next to place-oriented presence queries, such as “Who (...) is near?”. In this article, we describe a design space for place-based presence systems, in which we identify the most important aspects and options that designers of place-based presence systems need to consider. We also report on our exploratory research in this design space, comprising two cycles of designing, implementing and evaluating place-based presence prototypes. We conclude with lessons learned for future research in place-based presence systems. (shrink)

Notoriously, the Einstein equations of general relativity have solutions in which closed timelike curves occur. On these curves time loops back onto itself, which has exotic consequences: for example, traveling back into one's own past becomes possible. However, in order to make time travel stories consistent constraints have to be satisfied, which prevents seemingly ordinary and plausible processes from occurring. This, and several other "unphysical" features, have motivated many authors to exclude solutions with CTCs from consideration, e.g. by conjecturing a (...) chronology protection law. In this contribution we shall investigate the nature of one particular class of exotic consequences of CTCs, namely those involving unexpected cases of indeterminism or determinism. Indeterminism arises even against the backdrop of the usual deterministic physical theories when CTCs do not cross spacelike hypersurfaces outside of a limited CTC-region|such hypersurfaces fail to be Cauchy surfaces. We shall compare this CTC-indeterminism with four other types of indeterminism that have been discussed in the philosophy of physics literature: quantum indeterminism, the indeterminism of the hole argument, non-uniqueness of solutions of differential equations and lack of predictability due to insuffcient data. By contrast, a certain kind of determinism appears to arise when an indeterministic theory is applied on a CTC: things cannot be different from what they already were. Again we shall make comparisons, this time with other cases of determination in physics. We shall argue that on further consideration both this indeterminism and determinism on CTCs turn out to possess analogues in other, familiar areas of physics. CTC- indeterminism is close to the epistemological indeterminism we know from statistical physics, while the "fixedness" typical of CTC-determinism is pervasive in physics. CTC- determinism and CTC-indeterminism therefore do not provide incontrovertible grounds for rejecting CTCs as conceptually inadmissible. (shrink)

Introduction, W G Runciman Social Evolution in Primates: The Role of Ecological Factors and Male Behaviour, Carel P van Schaik Determinants of Group Size in Primates: A General Model, R I M Dunbar Function and Intention in the Calls of Non-Human Primates, Dorothy L Cheney & Robert M Seyfarth Why Culture is Common, but Cultural Evolution is Rare, Robert Boyd & Peter J Richerson An Evolutionary and Chronological Framework for Human Social Behaviour, Robert A Foley Friendship and the Banker?s Paradox: (...) Other Pathways to the Evolution of Adaptations for Altruism, John Tooby & Leda Cosmides The Early Prehistory of Human Social Behaviour: Issues of Archaeological Inference and Cognitive Evolution, Steven Mithen The Emergence of Biologically Modern Populations in Europe: A Social and Cognitive ?Revolution??, Paul Mellars Responses to Environmental Novelty: Changes in Men?s Marriage Strategies in a Rural Kenyan Community, Monique Borgerhoff Mulder Genetic Language Impairment: Unruly Grammars, M Gopnik, J Dalalakis, S E Fukuda, S Fukuda & E Kehayia The Emergence of Cultures among Wild Chimpanzees, Christophe Boesch Terrestriality, Bipedalism and the Origin of Language, Leslie C Aiello Conclusions, John Maynard Smith. (shrink)

This paper describes the introduction of Liebig's ideas on agricultural chemistry into the Netherlands. The aversion to Liebig held by the Utrecht professor G. J. Mulder hindered the direct influence that might have been borne by Liebig's own writings; the introduction was made principally by means of Dutch translations of the text-books of the Scottish agricultural chemist J. F. W. Johnston, who generally followed Liebig's ideas.

Response to commentaries on keynote article.

John Buridan was a fourteenth-century philosopher who enjoyed an enormous reputation for about two hundred years, was then totally neglected, and is now being 'rediscovered' through his relevance to contemporary work in philosophical logic. The final chapter of Buridan's Sophismata deals with problems about self-reference, and in particular with the semantic paradoxes. He offers his own distinctive solution to the well-known 'Liar Paradox' and introduces a number of other paradoxes that will be unfamiliar to most logicians. Buridan also moves on (...) from these problems to more general questions about the nature of propositions, the criteria of their truth and falsity and the concepts of validity and knowledge. This edition of that chapter is intended to make Buridan's ideas and arguments accessible to a wider range of readers. The volume should interest many philosophers, linguists and logicians, who are increasingly finding in medieval work striking anticipations of their own concerns. (shrink)

In this paper we consider an intuitionistic variant of the modal logic S4 (which we call IS4). The novelty of this paper is that we place particular importance on the natural deduction formulation of IS4— our formulation has several important metatheoretic properties. In addition, we study models of IS4— not in the framework of Kirpke semantics, but in the more general framework of category theory. This allows not only a more abstract definition of a whole class of models but also (...) a means of modelling proofs as well as provability. (shrink)

According to the prevailing sentiment, changing the past is logically impossible. The prevailing sentiment is wrong. In this paper, I argue that the claim that changing the past entails a contradiction ultimately rests upon an empirical assumption, and so the conclusion that changing the past is logically impossible is to be resisted. I then present and discuss a model of time which drops the empirical assumption and coherently models changing the past. Finally, I defend the model, and changing the past, (...) against objections. (shrink)