Diatoms are a species‐rich group of photosynthetic eukaryotes, with enormous ecological significance and great potential for biotechnology. During the last decade, diatoms have begun to be studied intensively using modern molecular techniques and the genomes of four diatoms have been wholly or partially sequenced. Although new insights into the biology and evolution of diatoms are accumulating rapidly due to the availability of reverse genetic tools, the full potential of these molecular biological approaches can only be fully realized if experimental control (...) of sexual crosses becomes firmly established and widely accessible to experimental biologists. Here we discuss the issue of choosing new models for diatom research, by taking into account the broader context of diatom mating systems and the place of sex in relation to the intricate cycle of cell size reduction and restitution that is characteristic of most diatoms. We illustrate the results of our efforts to select and develop experimental systems in diatoms, using species with typical life cycle attributes, which could be used as future model organisms to complement existing ones. BioEssays 30:692–702, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

ABSTRACTFree versus unfree was a fundamental axis of differentiation in ancient Near Eastern societies. Liberty was conceptualized as the power to govern oneself, free from another's domination, thus free to participate in constituting political authority. More concretely, the subject of the state was by definition free, this being the condition of obliging him for duty. Thus the relation between people and polity was predicated on liberty, not servitude as commonly supposed of an area still shackled to the Western ideology of (...) Oriental despotism. I argue that liberty was an operative principle in the organization of ancient Near Eastern polities, basing the case on sources from the Late Bronze Age. The first section sets forth general propositions, and the second puts them in ancient Near Eastern terms. The third and fourth sections examine documents from Ugarit and Emar, two polities under Hittite suzerainty, that illustrate how these principles operated in the lives of individuals. The fifth section examines how they were articulated at the scale of communities, through the lens of the poet who composed the Hurro-Hittite ‘Song of Liberation'. The conclusion draws together the ideas of liberty, bondage and liberation these sources disclose, ideas that remained productive in later ages. (shrink)

ZusammenfassungBei der Programmierung der Rechenautomaten ist es Brauch, den Gedankengang mit Skizzen zu begleiten and dadurch an‐schaulich zu machen. Durch Graphschemata können auch zahlentheore‐tische Funktionen definiert werden. Kaluẑnin stellte die Aufgabe, die derart definierten zahlentheoretischen Funktionen je nach der Kompliziert‐heit der betreffenden Graphschemata in Klassen zu teilen. Es war zuvermuten, dass man auf diese Weise konstruktive Zwischenstufen zwischen den bekannten speziell‐rekursiven Funktionen und den allgemein‐rekursiven Funktionen erhaält. Die vorliegende Arbeit zeigt, dass dieser Weg nicht gangbar ist, da sich jede allgemein‐rekursive (...) Funktion durch Graphschemata von ähnlicher Struktur definieren lässt. (shrink)

The Rho GTPases—Rho, Rac and Cdc42—act as molecular switches, cycling between an active GTP‐bound state and an inactive GDP‐bound state, to regulate the actin cytoskeleton. It has recently become apparent that the Rho GTPases can be activated in subcellular zones that appear semi‐stable, yet are dynamically maintained. These Rho GTPase activity zones are associated with a variety of fundamental biological processes including symmetric and asymmetric cytokinesis and cellular wound repair. Here we review the basic features of Rho GTPase activity zones, (...) suggest that these zones represent a fundamental signaling mechanism, and discuss the implications of zone properties from the perspective of both their function and how they are likely to be controlled. BioEssays 28: 983–993, 2006. © 2006 Wiley Periodicals, Inc. (shrink)

Much of what we believe we know, we know through the testimony of others. While there has been long-standing evidence that people are sensitive to the characteristics of the sources of testimony, for example in the context of persuasion, researchers have only recently begun to explore the wider implications of source reliability considerations for the nature of our beliefs. Likewise, much remains to be established concerning what factors influence source reliability. In this paper, we examine, both theoretically and empirically, the (...) implications of using message content as a cue to source reliability. We present a set of experiments examining the relationship between source information and message content in people's responses to simple communications. The results show that people spontaneously revise their beliefs in the reliability of the source on the basis of the expectedness of a source's claim and, conversely, adjust message impact by perceived reliability; hence source reliability and message content have a bi-directional relationship. The implications are discussed for a variety of psychological, philosophical and political issues such as belief polarization and dual-route models of persuasion. (shrink)

The Hermotimus is Lucian’s longest piece of writing, surpassing even the two books of the True Tales, and at the same time his most successful effort to recreate the style and atmosphere of a Platonic dialogue, filled with a new—and for Lucian uncharacteristically serious—content, namely a sustained attack on “dogmatic” philosophical schools (the “haireseis” of its subtitle) and, inversely, a ringing endorsement of the tenets of Pyrrhonian Scepticism.... (review at BMCR).

Von Hippel & Trivers (VH&T) interpret belief in God and belief in strong government as the outcome of an active process of self-deception on a worldwide scale. We propose, instead, that these beliefs might simply be a passive spin-off of efficient cognitive processes.

Von Peter Sloterdijk kann man zu Recht sagen, daß jeder seiner Aufsätze, jeder seiner Vorträge auch ein ungeschriebenes Buch ist.

First published in 1998, this volume why and how genetic engineering has emerged as the technology most likely to change our lives, for better or worse, in the opening century of the third millennium. Over twenty international experts, including moral philosophers and social scientists, describe the issues and controversies surrounding modern biotechnology and genetic engineering. They explore ways in which lay individuals and groups can join in an effective and constructive dialogue with scientists and industrialists over the assessment, exploitation and (...) safe management of these new and important technologies. Topics covered include a discussion of the issues surrounding 'Dolly', the cloned sheep, the politics and ethics of the international research programme to sequence the entire human genome, the ethical questions raised by the creation of transgenic farm animals, the morality of genetic experimentation on animals, the controversy surrounding the patenting of genetic material and of the transgenic animals themselves, the ethical implications of engineering animals for transplanting their organs into humans, and the environmental hazards of releasing genetically engineered organisms. (shrink)

Recent experimental work suggests that the concept of contextual fields should be generalized to allow the modulation of local information extraction by both external and internal context. The external context relates to the coherent information of the stimulus; the internal context refers to the parts of this information which are relevant for behavior. This dual interaction, present at every level of the hierarchy, requires a fundamental unit of processing more complex than a single neuron appears today. We argue that the (...) cortical column supplies the required mechanisms for a separate top-down and bottom-up processing and allows for interaction without destructive cross-talk. This flexibility might explain why the same basic architecture of a cortical column is used in the whole isocortex. (shrink)

In this essay, we consider helicases, defined as enzymes that use the free energies of binding and hydrolysis of ATP to drive the unwinding of double‐stranded nucleic acids, and ask how they function within, and are “coupled” to, the macromolecular machines of gene expression. To illustrate the principles of the integration of helicases into such machines, we consider the macromolecular complexes that direct and control DNA replication and DNA‐dependent RNA transcription, and use these systems to illustrate how machines centered around (...) coupled polymerase–helicase systems can be regulated by small changes in the interactions of their functional components. BioEssays 25:1168–1177, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

In der genannten Epoche werden Grundentscheidungen gefällt, welche die Fundamentalfrage der Philosophie, die Seinsfrage, in die Krisis führen, in den Nihilismus unter ontologischem, metaphysischem, epistemologischem, axiologischem Aspekt. Den Extrempositionen der Systemdenker Hegel, Schopenhauer und Schelling erwachsen in den Hegelkritikern Feuerbach, Br. Bauer, Marx und Stirner Kontrapositionen, die das Wahrheitsproblem der Beliebigkeit unterstellen. Kierkegaard klagt unter existentiellem Aspekt das Problem der Wahrheit ein. Nietzsche überholt durch Abschaffung der Wahrheit alle Positionen,was seinen Standort in der europäischen Denkgeschichte ausmacht und als Ergebnis der (...) problemgeschichtlichen Analysen zu charakterisieren ist. Die Rückgewinnung des Vernunfthorizontes setzen erst die Problemdenker N. Hartmann und M. Heidegger ins Werk durch kritische Erneuerung der Seinsfrage. (shrink)

Since the spectrum of possibilities in linguistic theory construction is much broader and more variegated than students of linguistics have perhaps been led to believe, the Current Issues in Linguistic Theory series has been established in order to provide a forum for the presentation and discussion of linguistic opinions of scholars who do not necessarily accept the prevailing mode of thought in linguistic science. CILT is a theory-oriented series which welcomes contributions from scholars who have significant proposals to make towards (...) the advancement of our understanding of language, its structure, functioning, and development. Current Issues in Linguistic Theory is especially designed, by offering an alternative outlet for meaningful contributions to the current linguistic debate, to furnish the community of linguists the diversity of opinion which a healthy discipline must have. (shrink)

This article addresses the ability of Parallel Distributed Processing (PDP) networks to generate stagewise cognitive development in accordance with Piaget's theory of cognitive epigenesis. We carried out a replication study of the simulation experiments by McClelland (1989) and McClelland and Jenkins (1991) in which a PDP network learns to solve balance scale problems. In objective tests motivated from catastrophe theory, a mathematical theory of transitions in epigenetical systems, no evidence for stage transitions in network performance was found. It is concluded (...) that PDP networks lack the ability to recover the positive outcomes of analogous catastrophe analyses of real cognitive developmental data. In an attempt to further characterize the learning behaviour of PDP networks, we carried out a second simulation study using the discrimination‐shift paradigm. The results thus obtained indicate that PDP learning is compatible with the learning of stimulus‐response relationships, not with the acquisition of mediating rules such as conceived in (neo‐)Piagetian theory. In closing, we speculate about the feasibility of simulating stagewise development with alternative network architectures. (shrink)

Voegelin's magisterial account of medieval political thought opens with a survey of the structure of the period and continues with an analysis of the Germanic invasions, the fall of Rome, and the rise of empire and monastic Christianity. The political implications of Christianity and philosophy in the period are elaborated in chapters devoted to John of Salisbury, Joachim of Flora, Frederick II, Siger de Brabant, Francis of Assisi, Roman law, and climaxing in a remarkable study of Saint Thomas Aquinas's mighty (...) thirteenth-century synthesis. Although _History of Political Ideas_ was begun as a textbook for Macmillan, Voegelin never intended it to be a conventional chronological account. He sought instead an original comprehensive interpretation, founded on primary materials and taking into account the most advanced specialist scholarship—or science as he called it—available to him. Because of this, the book grew well beyond the confines of an easily marketable college survey and until now remained unpublished. In the process of writing it, Voegelin himself outgrew the conceptual frame of a "History of Political Ideas," turning to compose _Order and History_ and the other works of his maturity. _History of Political Ideas_ became the ordered collection of materials from which much of Voegelin's later theoretical elaboration grew, structured in a manner that reveals the conceptual intimations of his later thought. As such, it provides an unparalleled opportunity to observe the working methods and the intellectual evolution of one of our century's leading political thinkers. In its embracing scope, _History of Political Ideas_ contains both analyses of themes Voegelin developed in his later works and discussions of authors and ideas to which he did not return or which he later approached from a different angle and with a different emphasis. _The Middle Ages to Aquinas_ has withstood the test of time. What makes it still highly valuable is its thoroughly revisionist approach, cutting through all the convenient clichés and generalizations and seeking to establish the experiential underpinnings that typified the medieval period. (shrink)