The balance between births and deaths in an age-structured population is strongly influenced by the spatial distribution of sub-populations. Our aim was to describe the demographic process of a fish population in an hierarchical dendritic river network, by taking into account the possible movements of individuals. We tried also to quantify the effect of river network changes (damming or channelling) on the global fish population dynamics. The Salmo trutta life pattern was taken as an example for.We proposed a model which (...) includes the demographic and the migration processes, considering migration fast compared to demography. The population was divided into three age-classes and subdivided into fifteen spatial patches, thus having 45 state variables. Both processes were described by means of constant transfer coefficients, so we were dealing with a linear system of difference equations. The discrete case of the variable aggregation method allowed the study of the system through the dominant elements of a much simpler linear system with only three global variables: the total number of individuals in each age-class. (shrink)

Three experiments explore the role of working memory in motor skill acquisition and performance. Traditional theories postulate that skill acquisition proceeds through stages of knowing, which are initially declarative but later procedural. The reported experiments challenge that view and support an independent, parallel processing model, which predicts that procedural and declarative knowledge can be acquired separately and that the former does not depend on the availability of working memory, whereas, the latter does. The behaviour of these two processes was manipulated (...) by providing or withholding visual (and auditory) appraisal of outcome feedback. Withholding feedback was predicted to inhibit the use of working memory to appraise success and, thus, prevent the formation of declarative knowledge without affecting the accumulation of procedural knowledge. While the first experiment failed to support these predictions, the second and third experiments demonstrated that procedural and declarative knowledge can be acquired independently. It is suggested that the availability of working memory is crucial to motor performance only when the learner has come to rely on its use. (shrink)

Hagiographical studies have seen significant advances in Franciscan scholarship over the last half a century with new critical editions of central texts being prepared. The fruits of this research have been made available in English translations, from the Omnibus of the Sources for the Life of St Francis to the publication of Francis of Assisi: Early Documents in three volumes with an excellent index at the turn of the new millennium. The examination of the life of Francis of Assisi is (...) now gravitating towards liturgical texts in order to gauge the image of the saint projected during the sacred liturgy in the Mass and the Divine Office. There is a growing realization that these liturgical texts did much to condition... (shrink)

While supporting the claim for culture in cetaceans, I suggest that Rendell and Whitehead's argument is potentially incomplete if based solely on ethnographic evidence. The notion of cetacean culture can also be explored experimentally. I hope to complement the authors' assertion by discussing dolphin brain and behavioural research findings, thus contributing to a more holistic argument for culture in dolphins.

Systems thinking is a general worldview concerning the nature of reality. It sees the world as composed of systems, and all particular entities populating reality as linked with other entities – the emergence of new properties denies the flatland of plain materiality, and generates entities of a higher order. Spirituality in historical and modern traditions has minimally amounted to relating oneself to a larger or higher systemic whole, which confers meaning to particular cases of existence. In some religious traditions this (...) larger systemic whole has been understood as a transcendental sphere of existence, whereas in other religious and spiritual traditions it has been seen as an immanent thatness. The search for spirituality and wisdom has never been confined to religious traditions, but has inspired other systems thinkers as well, for example in philosophy, the New Age movement, in developmental psychology, biology, or futures research. The American philosopher and theoretical psychologist Ken Wilber has discussed, re-interpreted and synthesized various views on spiritual development as well as systems thinking and has provided input for the New Age movement, comparative religion, developmental psychology, and world philosophy. In this article we will discuss the relationship between systems thinking and spirituality and will assess Ken Wilber’s contribution to their conceptualization. (shrink)

How close is spirituality to psychosis? Covering the interrelation of psychosis and spirituality from a number of angles, _Insanity and Divinity_ will generate dialogue and discussion, aid critical reflection and stimulate creative approaches to clinical work for those interested in the connections between religious studies, psychoanalysis, anthropology and hagiography. Bringing together an international range of contributors and covering many different types of religious experience, this book presents its theme in three parts: Psychoanalysis, belief and mysticism Anthropology, history and hagiography Psychology, (...) psychosis and religious experience. Each section includes discussion of the hinterland between madness and religious experience from the perspective of a number of religions, autobiographical accounts of those who have experienced a psychosis in which spirituality played a key part and a comprehensive review of the position of psychology research into the meaning and function of spirituality in relation to the psychoses. Insightful, enlightening and wide-ranging, _Insanity and Divinity_ is ideal for clinicians, academics and chaplains working in clinical settings. (shrink)

The Baptist Union of Southern Africa's future is conspicuous unless it understands the context within which it ministers in our 'rainbow nation'. As a union of churches, BUSA faces significant challenges that have been highlighted through a mixed-methods research approach. Through many months of data collection at the Baptist Union archives, an online survey and informal interviews spanning many parts of South Africa, the researcher practically demonstrates the importance of the cumulative results for the future of BUSA. This article highlights, (...) in overview fashion, a few of the major challenges that need to be urgently addressed in the light of BUSA's historic ecclesiological presuppositions that have their roots in the missional ministry of Hugo Gutshe who saw each of his Baptist congregants as missionary, and expanded the influence of BUSA in South Africa. (shrink)

The experimental and highly regarded Gifford Lectures at Edinburgh University was endowed in the late nineteenth century. Over the years, participants have including many leading representatives of religion, science, and philosophy. This series has as its subject, The Development of Mind. First published in 1972, the series continues to attract widespread interest. In this volume, contributors argue about the mind from diverse analytical standpoints. The focus of the series remains the relationship between religion, science, and philosophy. This volume attempts to (...) achieve a comprehensive view of the subject of mind. The mental development of children in the light of modern psychology is discussed, and the distinction between "how" and "why" questions is put forward with clarity. The development of mind is further contrasted with the evolution of embryos in the young. The mind is considered as a capacity for intellectual activity, and as a multi-purpose program. Goal-directed behavior and language development are given importance, and issues of cosmic purpose, and the how and why of evolution, are never far from the surface of the argument. The lecturers know their opposition and their positions, and the cut-and-thrust of the discussion has much acumen and wit to it. Issues ranging from the impact of mind on theories of religion, causation, and rational will are examined in an informal, yet compelling, manner. (shrink)

The paper shows a new example of nonuniqueness of the solutionto Newtonian equations of motion for infinite gravitational systems. Unlike otherexamples, the gravitational field presents no singularity, nor are the non-gravitational forcesintroduced in the model singular (in particular, there are no collisions). The result is also ofinterest because it points to an interesting limitation of the elementary (Newtonian) formulationof classical mechanics.