The usual way for new cells to come into being is by division of old cells. So the zygote, which is a—new—single cell formed from two, the sperm and ovum, is an exception. Textbooks of human genetics usually say that this new cell is beginning of a new human individual. What this indicates is that they suddenly forget about identical twins.

A significant proportion of conservationists' work is directed towards efforts to save disappearing species. This relies upon the belief that species extinction is undesirable. When justifications are offered for this belief, they very often rest upon the assumption that extinction brought about by humans is different in kind from other forms of extinction. This paper examines this assumption and reveals that there is indeed good reason to suppose current anthropogenic extinctions to be different in kind from extinctions brought about at (...) other times or by other factors. Having considered – and rejected – quantity and rate of extinction as useful distinguishing factors, four alternative arguments are offered, each identifying a way in which anthropogenic extinction is significantly different from other forms of extinction, even mass extinction: (1) Humans are a different kind of natural cause from other causes of extinction; (2) Extinctions brought about by humans are uniquely persistent; (3) Anthropogenic extinctions are effectively random whereas past mass extinctions are rule-bound; (4) The impact of the current anthropogenic extinction event differs from the impact of other extinction events of the past, such that future recovery may not follow past patterns. Together, these four arguments suggest that the present-day extinction event brought about by humans may be unprecedented and that we cannot clearly extrapolate from past to present recovery from extinctions. Although insufficient as justification for the claim that present-day extinctions are undesirable, the arguments provide some ammunition for conservationists' conviction that species extinction – in which humans play an accelerating role – ought to be prevented. (shrink)

One of the ways of dividing all philosophers into two kinds is by saying of each whether he is an ordinary man's philosopher or a philosophers' philosopher. Thus Plato is a philosophers' philosopher and Aristotle an ordinary man's philosopher. This does not depend on being easy to understand: a lot of Aristotle's Metaphysics is immensely difficult. Nor does being a philosophers' philosopher imply that an ordinary man cannot enjoy the writings, or many of them. Plato invented and exhausted a form: (...) no one else has written such dialogues. So someone with no philosophical bent, or who has left his philosophical curiosity far behind may still enjoy reading some of them. (shrink)

Maria Triassi,1 Elena Giancotti,2 Antonio Nardone,1 Giulia Mancini,3 Fabiana Rubba1 1Public, Preventive and Social Medicine School, University Federico II of Naples, Naples, Italy; 2Procurement and Transplantation Coordination, Naples, Italy; 3Sociology Unit, G D'annunzio University, Chieti-Pescara, Italy Introduction: The growing disparity between organ availability for transplantation and the number of patients in need has challenged the donation and transplantation community to develop innovative processes, ideas, and techniques to bridge this gap. Advances in the sharing of best practices in the donation community (...) have contributed greatly to this aim over the past 5 years. Studies published during the past five years were analyzed to gain insight on the evolving organizational areas and tools that the procurement and transplantation pathways have been focused on. The hypothesis assessed is that networking and efficacious handling of this complex path may be ameliorated by an adaptive organizational toolbox. Methods: A thorough search has been conducted using various databases, ie, Cochrane library, PubMed, EMBASE, Federico II University Open Archive. The evidence was considered following the Effective Practice and Organization of Care Group checklist. Prevalent organizational attitudes and areas were assessed, and various scenarios were analyzed. Initially, all titles and abstracts were screened. In the next phase, the full text of all abstracts considered potentially relevant by at least one of the reviewers was evaluated. Inconsistencies in decision-making within this second phase were solved based on consensus between both reviewers. In this phase, for every study we defined whether the organization was considered relevant and what the scenario was. The information was extracted from each study based on bibliographic details. As many as 1,071 studies were analyzed, and 81 were selected as potentially relevant. Results: We found three prevalent areas of interest focused on organizational elements: global organizational strategies scenario, clinical hospital organization, and citizenship and social scenario. Conclusion: We reached the conclusion that organization has a central role in different scenarios of procurement and transplantation in a continuum from government to hospital and finally among citizens. A standardized hospital pathway definitely remains the essential step in order to ameliorate either procurement or transplantation. Keywords: transplant procurement, management, organizational tool, network. (shrink)

This considerably revised second edition of Wittgenstein's 1914-16 notebooks contains a new appendix with photographs of Wittgenstein's original work, a new preface by Elizabeth Anscombe, and a useful index by E.D. Klemke. Corrections have been made throughout the text, and notes have been added, making this the definitive edition of the notebooks. The writings intersperse Wittgenstein's technical logical notations with his thoughts on the meaning of life, happiness, and death. "When the first edition of this collection of remarks appeared in (...) 1961 we were provided with a glimpse of the workings of Wittgenstein's mind during the period when the seminal ideas of the _Tractatus Logico-Philosophicus_ were being worked out. This second edition provided the occasion to be struck anew by the breadth, rigor, and above all the restlessness of that mind."—T. Michael McNulty, S. J., _The Modern Schoolman_. (shrink)

Based on the exactly solvable case of a harmonic oscillator, we show that the direct correspondence between the Bohr-Sommerfeld phase of semiclassical quantum mechanics and the topological phase of Aharonov and Anandan is restricted to the case of a coherent state. For other Gaussian wave packets the geometric quantum phase strongly depends on the amount of squeezing.