In this paper we try to answer the question whether diffusion is a possible mechanism to explain mesoderm induction in Amphibians. First the embryological data are discussed and a hypothesis for mesoderm formation is set forth. The blastula being essentially a hollow sphere, we assume that the induction mechanism in an embryo at the blastula stage can be simulated by diffusion-reaction processes on spherical surfaces. A model is constructed for the simple case when the source is held constant with respect (...) to time, the decay proportional to the concentration and the diffusion coefficient a constant, From simulation we find a (best) value for the decay constant to be 6 × 10–5/sec and for the diffusion constant to be 0.24 × 10– 6 cm2/sec. The relation between the parameters is derived from an analytic solution for the diffusion process on a spherical surface with a continuously producing point source and the concentration proportional to the decay. The form and regulative properties of the steady concentration gradient are discussed. (shrink)
Heterocyst spacing in blue -green bacteria is widely assumed to be due to a diffusible inhibitor. The inhibitor, a nitrogen-rich compound, probably glutamine, is produced via the N2-fixing enzymes of the heterocyst and in turn serves to suppress the induction of these enzymes and of the differentiation of vegetative cells to heterocysts. This simple morphogenetic mechanism operating in growing cellular filaments ofAnabaena species is investigated on the basis of a continuous and a discrete cellular model, as well as by cell-by-cell (...) simulation of the inhibitor transport. The resulting distances between heterocysts and kinetics of their production are compared with observations, and the values of physical parameters are estimated from the models. (shrink)
This paper presents an experimental study investigating artificial grammar learning (AGL) in monolingual and bilingual children, with and without dyslexia, using an original methodology. We administered a serial reaction time (SRT) task, in the form of a modified Simon task, in which the sequence of the stimuli was manipulated according to the rules of a simple Lindenmayer grammar (more specifically, a Fibonacci grammar). By ensuring that the subjects focused on the correct response execution at the motor stage in presence (...) of congruent or incongruent visual stimuli, we could meet the two fundamental criteria for implicit learning: the absence of an intention to learn and the lack of awareness at the level of resulting knowledge. The participants of our studies were four groups of 10-year-old children: 30 Italian monolingual typically developing children, 30 bilingual typically developing children with Italian L2, 24 Italian monolingual dyslexic children and 24 bilingual dyslexic children with Italian L2. Participants were administered the modified Simon task developed according to the rules of the Fibonacci grammar and tested with respect to the implicit learning of three regularities: (i) a red is followed by a blue; (ii) a sequence of two blues is followed by a red and (iii) a blue can be followed either by a red or by a blue. Results clearly support the hypothesis that implicit learning took place, since participants of all groups became increasingly sensitive to the structure of the input, implicitly learning the sequence of the trials and thus appropriately predicting the occurrence of the relevant items, as manifested by faster reaction times in predictable trials. Moreover, group differences were found, with bilinguals being overall faster than monolinguals and dyslexics less accurate than controls. Finally, an advantage of bilingualism in dyslexia was found, with bilingual dyslexics performing consistently better than monolingual dyslexics and, in some conditions, at the level of the two control groups. These results are taken to suggest that bilingualism should be supported also among linguistically impaired individuals. (shrink)
We show that in Kabbalah, the esoteric teaching of Judaism, there were developed ideas of unconventional automata in which operations over characters of the Hebrew alphabet can simulate all real processes producing appropriate strings in accordance with some algorithms. These ideas may be used now in a syllogistic extension of Lindenmayer systems, where we deal also with strings in the Kabbalistic-Leibnizean meaning. This extension is illustrated by the behavior of Physarum polycephalum plasmodia which can implement, first, the Aristotelian syllogistic (...) and, second, a Talmudic syllogistic by qal wa-homer. (shrink)
This article shows that Rabbi Pinchas Elijah Hurwitz, a major eighteenth-century kabbalist, Orthodox rabbi and Enlightenment thinker, who merged Lurianic Kabbalah with Kantian philosophy, attempted to describe God and the world in terms of formal grammars and abstract information processes. He resolves a number of Kant's dualistic views by introducing prophecy as a tool that allows a mystic's mind to perform transfinite hypercomputation and to obtain a priori knowledge about things usually known only a posteriori. According to Hurwitz, the reality (...) consists of Divine names, which generate an infinite network of recursive string rewriting systems, some of which are identical to what is known today as Lindenmayer systems. Hurwitz is also one of the first thinkers, who raised questions about non-human and artificial intelligence. (shrink)
This engaging and informative text will hold the attention of students and scholars as they take a journey through time to understand the role that history and philosophy have played in shaping the course of sport and physical education in Western and selected non-Western civilizations. Using appropriate theoretical and interpretive frameworks, students will investigate topics such as the historical relationship between mind and body; what philosophers and intellectuals have said about the body as a source of knowledge; educational philosophy and (...) the value of physical education and/or sport; philosophical positions that have impacted the historical development of sport and physical education; the history of women in sport and physical education; the role and scope of sport and physical education in Ancient Greece and Rome; the Ancient Olympic Games; the relationship between sport and religion in ancient and modern times; the theoretical and professional development of physical education; the rise of sport in modern America; the history and politics of the modern Olympic Games; and the contributions of men, women, and social movements to the development of sport and physical education from ancient times to the modern era. (shrink)
It is widely asserted that we are now living in a post-truth society. What that means, this book argues, is that the contemporary global world is thoroughly infested not only with trickster figures but an entire and operational trickster logic; or, that we now live in a Trickster Land - an argument advanced by the claim that in modernity liminality has become permanent; or that modern life is patently absurd. The first part of the book presents a series of 'guides' (...) to this condition, in the form of key thinkers and writers who can help us understand and navigate our Trickster Land. Such guides include Hermann Broch, Lewis Hyde, Roberto Calasso, Michel Serres, Sándor Márai, Colin Thubron, and Albert Camus. The second part goes on to discuss five main regions of Trickster Land: art, thought, the economy, politics, and society. This last, central chapter of the book contrasts trickster logic with the basic, foundational logic of social life, presented as gift-giving by Marcel Mauss and as sociability by Georg Simmel, and which is expressed here, combining Heraclitus and Plato with the Gospel of John, by three basic terms of ancient Greek culture, as arkhé charis logos: meaningful social life originally and in its essence is animated by the power of kind benevolence. This volume will appeal to scholars of social theory, anthropology and sociology with interests in political thought and contemporary culture. (shrink)
David Hume, philosopher, historian, economist, librarian, and essayist, was one of the great figures of the European Enlightenment. Unlike some of his famous contemporaries, however, he was not dogmatically committed to idealised conceptions of reason, liberty, and progress. Instead, Hume was a sceptic whose arguments questioned the reach and authority of human rationality, and who put the rivalrous passions of commercial life at the centre of his theory of human -- -- itself. -- ABOUT THE SERIES: The Very Short Introductions (...) series from Oxford University Press contains hundreds of titles in almost every subject area. These pocket-sized books are the perfect way to get ahead in a new subject quickly. Our expert authors combine facts, analysis, perspective, new ideas, and enthusiasm to make interesting and challenging topics highly readable. (shrink)
The nature of quantum computation is discussed. It is argued that, in terms of the amount of information manipulated in a given time, quantum and classical computation are equally efficient. Quantum superposition does not permit quantum computers to ''perform many computations simultaneously'' except in a highly qualified and to some extent misleading sense. Quantum computation is therefore not well described by interpretations of quantum mechanics which invoke the concept of vast numbers of parallel universes. Rather, entanglement makes available types of (...) computation processes which, while not exponentially larger than classical ones, are unavailable to classical systems. The essence of quantum computation is that it uses entanglement to generate and manipulate a physical representation of the correlations between logical entities, without the need to completely represent the logical entities themselves. (shrink)
The understanding of decision-making systems has come together in recent years to form a unified theory of decision-making in the mammalian brain as arising from multiple, interacting systems (a planning system, a habit system, and a situation-recognition system). This unified decision-making system has multiple potential access points through which it can be driven to make maladaptive choices, particularly choices that entail seeking of certain drugs or behaviors. We identify 10 key vulnerabilities in the system: (1) moving away from homeostasis, (2) (...) changing allostatic set points, (3) euphorigenic signals, (4) overvaluation in the planning system, (5) incorrect search of situation-action-outcome relationships, (6) misclassification of situations, (7) overvaluation in the habit system, (8) a mismatch in the balance of the two decision systems, (9) over-fast discounting processes, and (10) changed learning rates. These vulnerabilities provide a taxonomy of potential problems with decision-making systems. Although each vulnerability can drive an agent to return to the addictive choice, each vulnerability also implies a characteristic symptomology. Different drugs, different behaviors, and different individuals are likely to access different vulnerabilities. This has implications for an individual's susceptibility to addiction and the transition to addiction, for the potential for relapse, and for the potential for treatment. (shrink)
Ethical attitudes and behaviour are complex. This complexity extends to the influencers operating at different levels both outside and within the organisation, and in different combinations for different individuals. There is hence a growing need to understand the proximal and distal influencers of ethical attitudes, and how these operate in concert at the individual, organisational, and societal levels. Few studies have attempted to combine these main research streams and systematically examine their combined impact. The minority of studies that have taken (...) a combined approach have often done so using conventional statistical and analytical techniques which imply linearity between variables—a situation that rarely exists in business settings and is likely to lead to simplistic or even erroneous conclusions. Applying a fuzzy-set qualitative comparative analysis approach, this paper reports on the mutual and simultaneous influence of individual demographic factors, as well as proximal and distal factors stemming from within and outside the work environment to understand individuals’ ethical views within the workplace. The multiple configurations that emerged reveal the complex nature of influencers of ethical attitudes, and reinforce the view that “one size does not fit all”. We discuss these implications together with managerial recommendations and future research directions. (shrink)
Imagination in Inquiry investigates the nature, kinds, component elements, functions, scope, and uses of the imagination that are at work in inquiry. It develops a homeostatic model and discusses its applications in various branches of philosophy, from the philosophy of science and the philosophy of technology to ethics and aesthetics.
This companion is a cutting-edge primer to critical forms of the posthumanities and the feminist posthumanities, aimed at students and researchers who want to catch up with the recent theoretical developments in various fields in the humanities, such as new media studies, gender studies, cultural studies, science and technology studies, human animal studies, postcolonial critique, philosophy and environmental humanities. It contains a collection of nineteen new and original short chapters introducing influential concepts, ideas and approaches that have shaped and developed (...) new materialism, inhuman theory, critical posthumanism, feminist materialism, and posthuman philosophy. A resource for students and teachers, this comprehensive volume brings together established international scholars and emerging theorists, for timely and astute definitions of a moving target – posthuman humanities and feminist posthumanities. (shrink)
An entertaining history of the idea of nothing - including absences, omissions, and shadows - from the Ancient Greeks through the 20th century How can nothing cause something? The absence of something might seem to indicate a null or a void, an emptiness as ineffectual as a shadow. In fact, 'nothing' is one of the most powerful ideas the human mind has ever conceived. This short and entertaining book by Roy Sorensen is a lively tour of the history and philosophy (...) of nothing, explaining how various thinkers throughout history have conceived and grappled with the mysterious power of absence -- and how these ideas about shadows, gaps, and holes have in turned played a very positive role in the development of some of humankind's most important ideas. Filled with Sorensen's characteristically entertaining mix of anecdotes, puzzles, curiosities, and philosophical speculation, the book is ordered chronologically, starting with the Taoists, the Buddhists, and the ancient Greeks, moving forward to the middle ages and the early modern period, then up to the existentialists and present day philosophy. The result is a diverting tour through the history of human thought as seen from a novel and unusual perspective. (shrink)
Background: The magnitude of bullying and harassment among psychiatrists is reportedly high, yet no peer-review published studies addressing this issue could be found. Therefore, it was decided to conduct a pilot study to assess the degree of the problem, the types of bullying/harassment and to provide some insights into the situation.Methods and Principal Findings: Following multiple focus group meetings, a yes/no response type questionnaire was developed to assess the degree and type of bullying and harassment experienced by psychiatrists. Over a (...) 3-month period the questionnaire was administered to a random sample of 60 psychiatrists. 57 out of the 60 psychiatrists reported harassment and bullying. Frequencies of the following response variables are presented in descending order: rumours 40% ; defamation 20% ; passing remarks 20% ; false accusations 15% ; threats 13.3% ; verbal abuse 13.3% ; unjustified complaints 13.3% ; promotion blocked 13.3% ; humiliation 13% ; bad reference given 10% ; credentials questioned 8.3% ; physical attacks 5% ; termination 5% ; derogatory remarks 1.7% and 1.7% were subjected to personal work. As a result of being subjected to harassment, 66.7% of the psychiatrists did not take any action, whereas 33.3% confronted the person they believed responsible. Asked whether the bullying and harassment caused distress, 18.3% of the psychiatrists did not report any effect, 30% reported mild distress, 40% moderate distress and severe distress was reported by 11.7%.Conclusions: It was concluded that the magnitude of bullying and harassment among psychiatrists may be quite high, as evidenced by this pilot study. There is a need for extensive systematic studies on this subject and to establish strategies to prevent and address this issue at a national and regulatory level. (shrink)
In this paper, we provide a logical formalization of the emotion triggering process and of its relationship with mental attitudes, as described in Ortony, Clore, and Collins’s theory. We argue that modal logics are particularly adapted to represent agents’ mental attitudes and to reason about them, and use a specific modal logic that we call Logic of Emotions in order to provide logical definitions of all but two of their 22 emotions. While these definitions may be subject to debate, we (...) show that they allow to reason about emotions and to draw interesting conclusions from the theory. (shrink)
Society, Ethics, and the Law: Text Reader is designed for the criminal justice ethics course, typically taught within the criminal justice, philosophy, or social science department. This course is primarily taken by junior and senior undergraduate students who are majoring in criminal justice or other related fields. Ethics is one of the six required topic areas in criminal justice education as defined by the Academy of Criminal Justice Sciences. The Academy of Criminal Justice Sciences standards are located at www.acjs.org/page/ProgramStandards. The (...) required content areas are defined in B.5. Table 1. Although ACJS has moved away from 'certifying' academic programs, the standards still serve as the primary benchmarks for program reviews for criminal justice degree programs. The text consists of 12 sections with five readings per section. Each section consists of an Introduction to the section, three articles related to the topic, and a 'character in context' article. The character in context article is intended to be written by a practitioner with work experience connected to the theme of the section with a more conversational format (versus the articles which are traditional academic articles). This title is contributed by experts in the field, many of whom are prominent within ACJS and have been presenting their topics at relevant conferences to full audiences. The shorter, article format is designed to appeal to today's student, while providing a sufficient depth of coverage as expected by the course instructor. The selected articles range from traditional philosophical based academic articles to conversational style narratives of practitioners' experiences with ethic issues within the criminal justice system. The text will contain topics not traditionally covered in a criminal justice ethics course; this renders the book appealing to ethics courses offered in philosophy and social science departments, while also remaining relevant to criminal justice students. (shrink)
I would like to begin with the role of philosophy in solving ecological problems, emphasizing two aspects of its role: the struggle against hostile ideology and the organizing and guiding of activity in the sphere of the development of science and the shaping of its problems. This role of Marxist-Leninist philosophy clearly appears in the complex interdisciplinary problem of the interaction between nature and society.
Papers presented at a symposium on philosophy and medicine at the Institute for the Medical Humanities at the University of Texas Medical Branch in 1974 were published in the inaugural volume of this series.
Background: Increasing collaboration between industrialised and developing countries in human research studies has led to concerns regarding the potential exploitation of resource deprived countries. This study, commissioned by the former National Bioethics Advisory Commission of the United States, surveyed developing country researchers about their concerns and opinions regarding ethical review processes and the performance of developing country and US international review boards .Methods: Contact lists from four international organisations were used to identify and survey 670 health researchers in developing countries. (...) A questionnaire with 169 questions explored issues of IRB review, informed consent, and recommendations.Results: The majority of the developing country researchers were middle aged males who were physicians and were employed by educational institutions, carrying out research on part time basis. Forty four percent of the respondents reported that their studies were not reviewed by a developing country IRB or Ministry of Health and one third of these studies were funded by the US. During the review process issues such as the need for local language consent forms and letters for approval, and confidentiality protection of participants were raised by US IRBs in significantly higher proportions than by host country IRBs.Conclusion: This survey indicates the need for the ethical review of collaborative research in both US and host countries. It also reflects a desire for focused capacity development in supporting ethical review of research. (shrink)
Since it was first published, Quantum Field Theory in a Nutshell has quickly established itself as the most accessible and comprehensive introduction to this profound and deeply fascinating area of theoretical physics. Now in this fully revised and expanded edition, A. Zee covers the latest advances while providing a solid conceptual foundation for students to build on, making this the most up-to-date and modern textbook on quantum field theory available. -/- This expanded edition features several additional chapters, as well as (...) an entirely new section describing recent developments in quantum field theory such as gravitational waves, the helicity spinor formalism, on-shell gluon scattering, recursion relations for amplitudes with complex momenta, and the hidden connection between Yang-Mills theory and Einstein gravity. Zee also provides added exercises, explanations, and examples, as well as detailed appendices, solutions to selected exercises, and suggestions for further reading. (shrink)