We have synthesized a 582,970-base pair Mycoplasma genitalium genome. This synthetic genome, named M. genitalium JCVI-1.0, contains all the genes of wild-type M. genitalium G37 except MG408, which was disrupted by an antibiotic marker to block pathogenicity and to allow for selection. To identify the genome as synthetic, we inserted "watermarks" at intergenic sites known to tolerate transposon insertions. Overlapping "cassettes" of 5 to 7 kilobases (kb), assembled from chemically synthesized oligonucleotides, were joined by in vitro recombination to produce intermediate (...) assemblies of approximately 24 kb, 72 kb ("1/8 genome"), and 144 kb ("1/4 genome"), which were all cloned as bacterial artificial chromosomes in Escherichia coli. Most of these intermediate clones were sequenced, and clones of all four 1/4 genomes with the correct sequence were identified. The complete synthetic genome was assembled by transformation-associated recombination cloning in the yeast Saccharomyces cerevisiae, then isolated and sequenced. A clone with the correct sequence was identified. The methods described here will be generally useful for constructing large DNA molecules from chemically synthesized pieces and also from combinations of natural and synthetic DNA segments. 10.1126/science.1151721. (shrink)
Take a hypothetical sequence of human beings ordered by height from tallest to shortest. Make sure there is no more than a difference of a millimeter between each person and make sure the tallest person is clearly tall and the shortest person is clearly not tall. Now consider the following argument: P1 A person of height n is tall ; P2 For any height n, if n is tall, then n–1mm is tall ; C Therefore, a person of height n (...) = 1mm is tall. P1 and P2 are intuitively true, C is intuitively false, yet the argument is deductively valid (the conclusion follows... (shrink)
This is a collective writing project that is part of the larger design of Infantologies, Infanticides and Infantilizations; a quartet that explores the philosophy of infants from thematic perspectives, that puts infants at the centre of our reflections, and that encourages a different academic style of thinking.
A term with myriad associations, revolution is commonly understood in its intellectual, historical, and sociopolitical contexts. Until now, almost no attention has been paid to revolution and questions of geography. Geography and Revolution examines the ways that place and space matter in a variety of revolutionary situations. David N. Livingstone and Charles W. J. Withers assemble a set of essays that are themselves revolutionary in uncovering not only the geography of revolutions but the role of geography in revolutions. Here, (...) scientific revolutions—Copernican, Newtonian, and Darwinian—ordinarily thought of as placeless, are revealed to be rooted in specific sites and spaces. Technical revolutions—the advent of print, time-keeping, and photography—emerge as inventions that transformed the world's order without homogenizing it. Political revolutions—in France, England, Germany, and the United States—are notable for their debates on the nature of political institutions and national identity. Gathering insight from geographers, historians, and historians of science, Geography and Revolution is an invitation to take the where as seriously as the who and the when in examining the nature, shape, and location of revolutions. (shrink)
Do our lives have meaning? Should we create more people? Is death bad? Should we commit suicide? Would it be better to be immortal? Should we be optimistic or pessimistic? Since Life, Death, and Meaning: Key Philosophical Readings on the Big Questions first appeared, David Benatar's distinctive anthology designed to introduce students to the key existential questions of philosophy has won a devoted following among users in a variety of upper-level and even introductory courses.
Arthur Norman Prior (1914-69) was a logician and philosopher from New Zealand who contributed crucially to the development of ‘non-standard’ logics, especially of the modal variety. His greatest achievement was the invention of modern temporal logic, worked out in close connection with modal logic. However, his work in logic had a much broader scope. He was also the founder of hybrid logic, and he made important contributions to deontic logic, modal logic, the theory of quantification, the nature of propositions and (...) the history of logic. In addition, he discussed questions of ethics, free will, and general theology. Prior’s philosophical works comprise about 200 titles. His earliest articles center on philosophical theology and historical studies of Scottish Reformed Theology. This led on to the publication of his first influential work on ethics: Logic and The Basis of Ethics (1949). With the invention of tense-logic in the early 1950s, his focus shifted to investigations into the syntax of tempo-modal logic leading to his seminal Time and Modality (1957), a volume derived from his John Locke Lectures in Oxford in 1956. Furthermore Prior, together with the Irish mathematician and logician C.A. Meredith (1904-76), made important early contributions to the semantics of possible worlds. Prior’s tense-logic provided a strong conceptual framework for problems pertaining to the philosophy of time. In Time and Modality, Prior discussed the philosophical implications of Ruth Barcan’s famous formulae for tense-logic, and in the 1960s he worked on the notion of the present. The most persistent problem running through Prior’s work is his study of the questions surrounding human freedom and divine foreknowledge, and more general philosophical problems emerging from this classical theological question. His thorough analysis of this problem, with the conceptual tools of tense-logic, received a crucial impetus from his correspondence with the young Saul Kripke, when the latter suggested the semantic tool of branching time to Prior. Prior’s development of two solutions based on branching time for the problem of future contingency, the Peircean and the Ockham solution, was most thoroughly developed in Past, Present and Future (1967), the most important work published by Prior. Characteristically for Prior’s methodological approach, the development of these two solutions were at the same time a development of two new systems of tense logic, and vice versa. One of Prior’s significant contributions to logic was his work on world propositions and instant propositions. In the course of developing these notions he also made one of the earliest formulations of hybrid logic. In Papers on Time and Tense (1968), he presented this idea in a more detailed manner in the context of his four grades of tense-logical involvement. (shrink)
There is widespread belief that connectionist networks are dramatically different from classical or symbolic models. However, connectionists rarely test this belief by interpreting the internal structure of their nets. A new approach to interpreting networks was recently introduced by Berkeley et al. (1995). The current paper examines two implications of applying this method: (1) that the internal structure of a connectionist network can have a very classical appearance, and (2) that this interpretation can provide a cognitive theory that cannot be (...) dismissed as a mere implementation. (shrink)
LIBERTY IN HUME'S HISTORY OF ENGLAND In his own lifetime, Hume was feted by his admirers as a great historian, and even his enemies conceded that he was a controversial historian with whom one had to reckon. On the other hand, Hume failed to achieve positive recognition for his philosophical views. It was Hume's History of England that played an influential role in public policy debate during the eighteenth century in both Great Britain and in the United States. Hume's Hist01Y (...) of England passed through seven editions and was beginning to be perceived as a classic before Hume's death. Voltaire, as an historian, considered it "perhaps the best ever written in any lan guage. " Gibbon greatly admired Hume's work and said, of a letter written by Hume in 1776 praising the Decline and Fall of the Roman Empire, that a compliment from Hume "overpaid the labor of ten years. " After Hume's death on August 20, 1776, the History became a factor in the revolutionary events that began to unfold. Louis XVI was a close student of Hume's History, and his valet records that, upon having learned that the Convention had voted the death penalty, the King asked for the volume in Hume's History covering the trial and execution of Charles I to read in the days that remained. But if Louis XVI found the consolations of philosophical history in the Stuart volumes, Thomas Jefferson saw in them a cause for alarm. (shrink)
Philosophers of science don't very often discuss the place of mathematics between other sciences or the meaning of mathematics for other sciences. They consider mathematics as a formal language with mainly analytical statements about the use of symbols (Carnap, Russell, Ayer ). Originally Wittgenstein defended this formalistic interpretation of mathematics in his TLP. Gradually, however, he develops himself towards an intuitionistic and ontological position, in which mathematics is conceived as the central and therefore normative part of our thought (of course (...) : on what there is and how it is). Mathematical science plays the role of logic in relation to other sciences. Its universal applicability and efficiency are consequences of its creating beings on a necessary level, in virtue of the number of its relations (always still by substitution). This highly important philosophy of mathematics (misinterpreted by Crispin Wright) starts with his lectures in Cambridge (in the thirties ) and reaches its culmination in the Remarks on the Foundations of Mathematics and in On Certainty. In a second part this philosophical determination of mathematical reasoning is traced backwards through history. David Hume's contribution is reinterpreted from a new point of view. Inside the total field of our beliefs he distinguishes between different sciences with the critérium of the intricacy of relations between items of our knowledge field. The more and stronger these relations, the more forceful and necessary their influence on the remaining parts of the system of our belief. So mathematics is in the centre, the loose reveries of our fancy on the periphery. Quine's representation of ‘the tribunal of sense experience’, by which the total field should be judged and corrected, must be disqualified. Hume's dictum ‘Whatever we conceive, we conceive it to be existent’ reveals sharply that this evaluative and corrective role is performed by the necessary thoughts (or, if one likes it so, ‘realities’) of mathematical science. That reason and especially mathematical reason is the highest judge on the population and structure of our world and a very precious heritage of Pythagorism and Platonism. From the sources of Sextus Empiricus and Aristotle the author tries to reconstruct exactly the original assertion of Pythagoristic mathematical philosophy, which has nothing to do with a naive hypostazation of numbers or a kabbalistic number mysticism. Philolaos' saying, that some propositions are stronger than we, is demonstrated to refer to mathematical laws. The pythagorical position is fully integrated in Plato's dialectical philosophy. Mathematics is the great mediator towards the intuition of true being, the ‘metaxu’ between sensible phenomena and ideas. This tradition of philosophical taxation of mathematics as the ‘logic of science’ is broken by Aristotle, who didn't use mathematics in his qualitative natural science and considered mathematics as an abstract science (about the quantitative aspect of being). Moreover, he disowned its logical role and created a special science for this task. Human reason is mathematical in so far it is sure of its language and thought, which is excellently expressed by the Greek μαθηματιxα (= what can be understood, learned and taught) and by the Dutch word ‘wiskunde’ (= science of what is certain). The remarks and reflections of Wittgenstein have produced a new perspective on the placevalue (‘Stellenwert’) of mathematics among all possible sciences and beliefs and have proven that its onto-logical purport is an unavoidable implication. (shrink)
Recent EEG studies on the early postmortem interval that suggest the persistence of electrophysiological coherence and connectivity in the brain of animals and humans reinforce the need for further investigation of the relationship between the brain’s activity and the dying process. Neuroscience is now in a position to empirically evaluate the extended process of dying and, more specifically, to investigate the possibility of brain activity following the cessation of cardiac and respiratory function. Under the direction of the Center for Healthy (...) Minds at the University of Wisconsin-Madison, research was conducted in India on a postmortem meditative state cultivated by some Tibetan Buddhist practitioners in which decomposition is putatively delayed. For all healthy baseline and postmortem subjects presented here, we collected resting state electroencephalographic data, mismatch negativity, and auditory brainstem response. In this study, we present HB data to demonstrate the feasibility of a sparse electrode EEG configuration to capture well-defined ERP waveforms from living subjects under very challenging field conditions. While living subjects displayed well-defined MMN and ABR responses, no recognizable EEG waveforms were discernable in any of the tukdam cases. (shrink)