White Review Research Articles

Continuing the conversation

ABSTRACTI offer some responses to the principal points raised by Ben Kotzee, Alexis Gibbs, Sheron Fraser-Burgess, and Nigel Tubbs in their commentaries on my book, The Main Enterprise of the World: Rethinking Education (MEW), and to John White's penetrating and constructive review (the four commentaries and White's review all appear in this issue). In reply to Kotzee's challenge, I argue that MEW supports an improved approach to specialized scientific education, and that worries about the future of technology are unfounded. Gibbs’ critique, I contend, assumes a one-size-fits-all approach to the arts, in an area where I am concerned to make fine differentiations. Fraser-Burgess is right to wonder how my educational program can overcome the problems of multicultural, multiracial, multiethnic societies, but I maintain that the approach to educating citizens MEW outlines is the appropriate means to address those problems. Finally, I am happy to modify my conception of the Deweyan Society by introducing the kinds of Socratic explorations Tubbs proposes.John White introduces a number of significant issues and concerns. Some of these arise, I claim, from his adoption of familiar versions of concepts MEW takes pains to explicate in new ways. Since I argue for the superiority of my explicated versions, I view the correct strategy to involve discarding the presuppositions of the traditional notions White favours. With respect to moral education, for example, White's ‘precept-centered’ conception contrasts with my emphasis on the fundamental importance of skills of mutual engagement. His most extensive discussion, on my approach to fulfilment, poses a deep challenge. Here, I attempt to clarify and motivate the concepts I deploy. With respect to his review, however, as with my exchanges with the other commentators, this response can only be the beginning of what I hope will continue to be a fruitful conversation.

In This Issue

In This Issue

Metabolism Is Not Boring

![Figure][1] CREDIT: PAINTING: DAVID S. GOODSELL/SCIENTIFIC DESIGN: ZHOU DU AND DANIEL J. KLIONSKY So investigator Steven McKnight admonished his audience last spring after a presentation at a conference (on metabolism and cancer, no less). He may have been “preaching to the choir” in this case, but what led him to issue such a blunt reminder? It seems that for a generation of biological scientists, metabolism was an area of biochemistry to be mastered and then put aside. Metabolism was always there in the background, providing the cell with the energy and resources to do what was required, but was rarely recognized to determinedly influence, and be influenced by, the physiological state of the cell. This special issue of Science celebrates a resurgence of interest in metabolism and an appreciation of its central role in disparate areas of cell biology, physiology, medicine, and synthetic biology ([www.sciencemag.org/special/metabolism/][2]). McKnight's Perspective (p. [1338][3]) takes a broad look at the field and justifies his excitement that recognizing the reciprocal regulation of metabolism and other cellular processes promises to advance our understanding of complex physiology. There is renewed interest in the metabolism of cancer cells and its potential as a therapeutic target. Levine and Puzio-Kuter (p. [1340][4]) review metabolic changes in cancer cells, as well as the recent suggestion that alterations in a metabolic enzyme can lead to the production of an “oncometabolite” that supports cancer cell growth. When energy sources are limited, cells use a process known as autophagy for breaking down cellular components to provide substrates for metabolism. Rabinowitz and White's Review (p. [1344][5]) discusses roles of autophagy in metabolism, its regulation, and its implications for cancer and degenerative diseases. Of course not all fields have neglected metabolism over the years, and an enormous literature describes the role of insulin and related hormones in controlling cellular metabolism. In a Focus Issue of Science Signaling , a Research Article and Perspective describe an unexpected signal from the insulin receptor that confers sensitivity to cell death when insulin is not present. Also highlighted are a role for lipids as cellular sensors of glucose metabolism and a mechanism by which cells can survive oxidative stress by shifting the activity of the cell's protein degradation complex, the proteasome. In Science Translational Medicine , Vallerie and Hotamisligil review how in a strategy to combat obesity and insulin resistance, a therapeutic inhibitor of cell signaling pathways must have coordinated actions in multiple cell types. Back in Science , Bass and Takahashi (p. [1349][6]) review new insights into the interaction of metabolism with circadian clocks. Displacement of eating and periods of activity away from the normal light-dark cycle, as experienced in jet lag or shift work, have marked effects on metabolic diseases. Cellular metabolic pathways, particularly in yeast or bacteria, can be exploited to synthesize compounds that are difficult or expensive to produce by other means. Keasling (p. [1355][7]) reviews advances in metabolic engineering and looks forward to a future in which customized microbes made by computer-aided design can efficiently produce desired chemicals, ranging from fuels to pharmaceuticals. See? It's not boring at all! [1]: pending:yes [2]: http://www.sciencemag.org/special/metabolism/ [3]: /lookup/doi/10.1126/science.1199908 [4]: /lookup/volpage/330/1340?iss=6009 [5]: /lookup/doi/10.1126/science.1193497 [6]: /lookup/volpage/330/1349?iss=6009 [7]: /lookup/doi/10.1126/science.1193990

The Application of in Vitro Models to Research on Demineralization and Remineralization of the Teeth: Reaction Paper

Despite the advantages of in situ model studies, in vitro models are most important to provide insight into the mechanism of dental caries, the mechanisms of fluoride action, and profile screening. In this reaction paper following Dr. White's review, the emphasis is, first, on the role of mobile fluoride (FL) in fluoride efficacy, the formation of "CaF2-like" material as fluoride reaction product, and on fluoride reaction product localization. Second, mineral assessment techniques are discussed. Finally, the main differences between caries lesion formation in vitro and in situ are considered.