In eukaryotes, folate metabolism is compartmentalized between the cytoplasm and organelles. The folate pathways of mitochondria are adapted to serve the metabolism of the organism. In yeast, mitochondria support cytoplasmic purine synthesis through the generation of formate. This pathway is important but not essential for survival, consistent with the flexibility of yeast metabolism. In plants, the mitochondrial pathways support photorespiration by generating serine from glycine. This pathway is essential under photosynthetic conditions and the enzyme expression varies with photosynthetic activity. In (...) mammals, the expression of the mitochondrial enzymes varies in tissues and during development. In embryos, mitochondria supply formate and glycine for purine synthesis, a process essential for survival; in adult tissues, flux through mitochondria can favor serine production. The differences in the folate pathways of mitochondria depending on species, tissues and developmental stages, profoundly alter the nature of their metabolic contribution. BioEssays 28: 595–605, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

ABSTRACT How are scientists made? How, as young adults, have they discovered a scientific vocation and career? Through formal schooling, typically; but in the field sciences also through practical apprenticeship—through work. This essay presents the story of a frontier farm lad who became a career naturalist as a hired collector of animal specimens in the American West. Family and work are the leitmotifs of Vernon Bailey's story. It was family farming—bringing in the hay and finding the cows—that connected Bailey's love (...) of skilled outdoor work with a desire to know nature scientifically. Traveling and working with professional naturalists, he came to see himself as a professional as well. His socialization was less a replacement than a layering of two identities, family and career. (shrink)

In lieu of an abstract, here is a brief excerpt of the content:Buddhist-Christian Studies 23 (2003) 174-178 [Access article in PDF] Zen and the Kingdom of Heaven. By Tom Chetwynd. Boston: Wisdom Publications, 2001. 153 pp. Tom Chetwynd brings many strengths to his book of reflections on Zen and Christianity. Because his most obvious strength is his craft as a professional writer, he offers us a book that is well written, carefully organized, and a pleasure to read. He divides his (...) reflections into three parts: "Zen Experience," "Christian Meditation in the Light of Zen," and finally, "Christian Zen Practice." It is especially in the first and third parts that the author is particularly helpful for Christians engaged in interfaith dialogue.In part 1 Chetwynd's reflections on the Zen experience are autobiographical. He tells us that he came to Zen as a committed adult Christian who did not jettison his faith for another but rather labored to integrate his Christian faith and his Zen experience. Those of us who travel this very same path are familiar with the stages of Chetwynd's journey: in the first stage our attention is drawn to Zen by a random phrase in a book or by a friend's interest in Zen; then follows our first attempt to sit in a sesshin with others; then the experience of boredom, pain, and frustration, all of which give birth to the conviction that Zen might very well work for others but not for us. However, our first meeting with a charismatic roshi who inspires, encourages, and launches us back on the journey with the challenging and consoling words: "[You] can do it." These words help us both to ignore our fear and to sustain our resolve to sit with vigor to the last bell.What makes Chetwynd's experience so extraordinary and unique was the rapid opening of his mind. After his very first sitting, he tells us, he experienced his teacup "shining alone in empty space," and immediately following his first sesshin, Chetwynd reveals that his teacher, a Japanese monk, assured him that "he [the teacher] had nothing more to give [him/the student]." Chetwynd's experience very much reminds me of an incident that happened years ago in Tokyo. At a meeting with Kadowakii Roshi, he introduced me to a Mexican Jesuit who, the Roshi revealed, had experienced kensho during his first sesshin. I will always remember the Roshi's expression [End Page 174] of surprise and admiration as he uttered how wonderful and rare indeed was such an experience.Chetwynd is candid about the effect that the Zen experience has on his Christian faith: comparing his Zen experience to the latter, he confesses that his three years of theological study were "all for nothing"; he acknowledges that he believes he has received more insight from one week of Zen sitting than from the twenty-five years he practiced Christianity; he claims that while his Zen experience enables him to return to his Christian prayer and liturgy with new insight, it also makes him aware that while engaging in these spiritual exercises, he finds his heart is elsewhere. He goes on to reveal that he fears losing his faith because the idea of a godless universe "quite simply appall[s him]." Possibly adding to his quandary was Kyudo Roshi's reaction to Chetwynd's question about the value of the prayer of petition. On two occasions the author tells us that his teacher "chuckled" in response to his question about the prayer of petition. One would hope that in interreligious encounters with Christians, Zen teachers in their compassionate outreach would remember that what is amusing to them—the value of the prayer of petition and its opposite, a godless universe—is "quite simply appalling" to their Christian friends.Chetwynd's second part of the book, the story of Christian meditation in the light of the Zen experience, is extremely tentative. In it he builds a case for a number of possibilities: he suggests that the dharma of the Buddha is "not recognizably different" from the Kingdom of Heaven in Christian terminology; that the essential nature of the universe is not... (shrink)

A new version of the ontological argument for the existence of God is outlined and examined. After giving a brief account of some traditional ontological arguments for the existence of God, where their defects are identified, it is explained how this new argument is built upon their foundations and surmounts their defects. In particular, this version uses the resources of impossible worlds to plug the common escape route from standard modal versions of the ontological argument. After outlining the nature of (...) impossible worlds, and motivating the need for positing them, the new argument is delineated and its premises justified. It is taken for granted that the argument cannot be sound, since it would prove too much. However, its premises are all plausible, and their denial promises to have significant ramifications. Several intuitive lines of objections are then explored in order to illuminate their shortcomings. The puzzle that the argument poses is therefore not whether the argument is sound, for it clearly cannot be. Rather, it is to place pressure on its plausible premises, so some plausible account of how the argument fails can be identified, and that the devising of such an account promises to be insightful. In the process, we should gain an improved understanding of how such ontological arguments work. (shrink)

It is widely assumed that a geometric model of boundaries, which prescribes a tripartite topological characterisation of the boundaries for material objects – fully open, fully closed, or partially open/closed – can be unproblematically extended from regions to material objects. Drawing on a disanalogy between regions and material objects – that only the latter move – I demonstrate the incoherence of open material objects through two arguments relating to the ability for such objects to freely move. The first is a (...) dilemma considering separately open material objects occupying their location directly or indirectly. It is argued that movement in the former case would involve a miraculous topological transformation; whilst in the latter case, would involve miraculous reorganising movements in the object's proper parts. The second argument reignites a problem regarding the moment of change specifically for the movement of such objects. (shrink)

This paper advances the thesis that the raw version of the butterfly dream story in the Chuang-tzu is logically untenable and should thus be replaced by a logically coherent altered version. First, it sets out the positive meaning of the butterfly dream. Second, it examines the raw version of the butterfly dream so as to point up its inherent illogicality. Third, it sets out a modified version of the butterfly dream and demonstrates its superior logicality. Fourth, it shows how conventional (...) interpretations of the butterfly dream story—the ‘confusion hypothesis’ and the ‘external endless transformation’ hypothesis—arise from the raw version and identifies basic weaknesses in the conventional interpretation options. Fifth and last, it returns to an in-depth consideration of the interpretation which arises from a re-ordering of the butterfly dream story fragments. The raw version of the story makes little sense, which is why, I propose, it has lacked a satisfactory interpretation. This thesis stands on three presuppositions. The butterfly dream story is an analogy of the enlightenment experience. The enlightenment experience, or the experience of illumination, is the phenomenological correlate of the central objective of the Chuang-tzu, that of self-transformation. And the enlightenment experience is not only the phenomenological correlate, but the essential pre-condition for self-transformation. By refashioning our (mis)interpretations of the butterfly dream story, we can more fully appreciate its transformative message. (shrink)

John Dewey ranks as the most influential of America's philosophers. That in fluence stems, in part, from the originality of his mind, the breadth of his in terests, and his capacity to synthesize materials from diverse sources. In addi tion, Dewey was blessed with a long life and the extraordinary energy to express his views in more than 50 books, approximately 750 articles, and at least 200 contributions to encyclopedias. He has made enduring intellectual contributions in all of the traditional (...) fields of philosophy, ranging from studies primarily of interest for philosophers in logic, epistemology, and metaphysics to books and articles of wider appeal in ethics, political philosophy, religion, aesthetics, and education. Given the extent of Dewey's own writings and the many books and articles on his views by critics and defenders, it may be asked why there is a need for any further examination of his philosophy. The need arises because the lapse of time since his death in 1952 now permits a new generation of scholars to approach his work in a different spirit. Dewey is no longer a living partisan of causes, sparking controversy over the issues of the day. He is no longer the advocate of a new point of view which calls into question the basic assump tions of rival philosophical schools and receives an almost predictable criticism from their entrenched positions. His works have now become classics. (shrink)

The sciences and popular views generally consider matter from the bottom up, that is, as the least common denominator underlying all of its various forms and realizations. In Rahner sensibility is matter looked at from the top down, that is, with a view to the highest realization of matter in human beings, and in Christ. In Whitehead creativity is matter, not inert or static but spontaneous and active, and creativity is matter viewed in light of its highest realizations in humans (...) and in God. So, in Rahner and in Whitehead, matter is viewed in much the same way, called sensibility in Rahner, and creativity in Whitehead, and defined in terms of its actualization in human nature. (shrink)

First published in 1981. Routledge is an imprint of Taylor & Francis, an informa company.