Receptor‐mediated stimulation induces massive actin polymerization and cyto‐skeletal reorganization. The activity of a potent actin‐modulating protein, gelsolin, is regulated both by Ca2+ and polyphos‐phoinositides, and it may have a pivotal role in restructuring the actin cytoskeleton in response to agonist stimulation. Structure‐function analysis of gelsolin has (1) indicated that its NH2‐terminal half is primarily responsible for modulating actin filament length and polymerization; and (2) elucidated mechanisms by which Ca2+ and phospholipids may regulate such functions. Gelsolin is functionally and structurally similar (...) to villin, another Ca2+‐activated actin‐severing protein found in microvilli, suggesting that gelsolin may be a prototype of this family of actin‐modulating proteins. A molecular variant of gelsolin is secreted and may be involved in the clearance of actin filaments released during tissue damage. The two forms of gelsolin are encoded by a single gene, and distinct messages are derived by alternative message splicing. (shrink)

Commentators are divided on the interpretation of Metaphysics Z4 1029b13–22. For one thing, it is unclear whether the passage rejects a claim about the essence of surface, or about the essence of pale. It is usually thought that the claim is disavowed because it involves a circular definition. However, this is conjectural, since Aristotle does not explicitly say anything about circularity in the lines in question. I argue here for an alternative account, which reads the disputed lines as an extension (...) of the immediately preceding remarks. If correct, this also solves the problem as to just what Aristotle is denying. As will emerge, my story is helped by St. Thomas’ reading of lines 21–22, an account that has been curiously ignored in the recent literature. (shrink)

A part of relativistic dynamics is axiomatized by simple and purely geometrical axioms formulated within first-order logic. A geometrical proof of the formula connecting relativistic and rest masses of bodies is presented, leading up to a geometric explanation of Einstein's famous E = mc² . The connection of our geometrical axioms and the usual axioms on the conservation of mass, momentum and four-momentum is also investigated.

The challenge in maintaining patient autonomy regarding medical decision-making and confidentiality lies not only in control over information transferred to and regarding patients, but in the ambiguity of autonomy itself. post-modernity is characterized by the recognition of not just numerous accounts of autonomy, but by the inability in a principled fashion to select one as canonical. Autonomy is understood as a good, a right-making condition, and an element of human flourishing. In each case, it can have a different content, depending (...) in part on whether it is given a nomological or a volitional construal. Different accounts of autonomy can lead to strikingly different understandings of appropriate behavior, including the argument that one ought on behalf of autonomy to liberate individuals from the sense of autonomy they themselves affirm. In the face of competing accounts of moral probity, autonomy in a secular morality and bioethics must by default be understood in terms of the permission of patients, which makes space for numerous moral accounts and different communal construals of free choice, which in turn will legitimate different practices of informing patients and maintaining confidentiality. (shrink)

A fundamental link between system theory and statistical mechanics has been found to be established by the Kolmogorov entropy K. By this quantity the temporal evolution of dynamical systems can be classified into regular, chaotic, and stochastic processes. Since K represents a measure for the internal information creation rate of dynamical systems, it provides an approach to irreversibility. The formal relationship to statistical mechanics is derived by means of an operator formalism originally introduced by Prigogine. For a Liouville operator L (...) and an information operator $\tilde M$ acting on a distribution in phase space, it is shown that i[L, $\tilde M$ ]≡KI (I=identity operator). As a first consequence of this equivalence, a relation is obtained between the chaotic correlation time of a system and Prigogine's concept of a “finite duration of presence.” Finally, the existence of chaos in quantum systems is discussed with respect to the existence of a quantum mechanical time operator. (shrink)

OBJECTIVES: To determine the relationship between ethical reasoning and gender and occupation among a group of male and female nurses and doctors. DESIGN: Partialist and impartialist forms of ethical reasoning were defined and singled out as being central to the difference between what is known as the "care" moral orientation (Gilligan) and the "justice" orientation (Kohlberg). A structured questionnaire based on four hypothetical moral dilemmas involving combinations of (health care) professional, non-professional, life-threatening and non-life-threatening situations, was piloted and then mailed (...) to a randomly selected sample of doctors and nurses. SETTING: 400 doctors from Victoria, and 200 doctors and 400 nurses from New South Wales. RESULTS: 178 doctors and 122 nurses returned completed questionnaires. 115 doctors were male, 61 female; 50 nurses were male and 72 were female. It was hypothesised that there would be an association between feminine subjects and partialist reasoning and masculine subjects and impartialist reasoning. It was also hypothesised that nurses would adopt a partialist approach to reasoning and doctors an impartialist approach. No relationship between any of these variables was observed. (shrink)

Study of Islamic philosophy of Yaḥyá ibn Ḥabash Suhrawardī, 1152 or 1153-1191.

Aristotle was the first philosopher in the Western tradition to address politics systematically and empirically, and he remains a central figure in political theory. This essential volume presents Aristotle's complete political writings—including his Politics, Economics, and Constitution of Athens—in their most authoritative translations, taken from the complete works that is universally recognized as the standard English edition. Edited by Jonathan Barnes, one of the world’s leading scholars of ancient philosophy, and with an illuminating introduction by Melissa Lane, an authority on (...) ancient political philosophy, this compact but comprehensive volume will be invaluable for all students of politics, philosophy, classics, or Western thought. (shrink)

Traditional hardcopy publishing brought about a division of labor between producers and disseminators of information. Online publishing makes it feasible for authors to disseminate their work much more widely without any investment in equipment beyond the ubiquitous laptop, without labor costs and without any special technical expertise. As a consequence, the division of labor is no longer important and is, in a range of cases, inefficient. For some scholarly works and teaching materials in particular, traditional hardcopy publishing rather than rather (...) than facilitating the dissemination of creative works not only restricts access to these materials but also undermines their production. Arguably, hardcopy journals and textbook anthologies, are inefficient and only persist because of institutional inertia and what has become the vicious circle of academic publishing. (shrink)