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)

The dominant approach to environmental policy endorsed by conservative and libertarian policy thinkers, so-called “free market environmentalism”, is grounded in the recognition and protection of property rights in environmental resources. Despite this normative commitment to property rights, most self-described FME advocates adopt a utilitarian, welfare-maximization approach to climate change policy, arguing that the costs of mitigation measures could outweigh the costs of climate change itself. Yet even if anthropogenic climate change is decidedly less than catastrophic, human-induced climate change is likely (...) to contribute to environmental changes that violate traditional conceptions of property rights. Viewed globally, the actions of some countries—primarily industrialized nations—are likely to increase environmental harms suffered by other countries—less developed nations that have not made any significant contribution to climate change. It may well be that aggregate human welfare would be maximized in a warmer, wealthier world, or that the gains from climate change will offset environmental losses. Yet such claims, even if demonstrated, would not address the normative concern that the consequences of anthropogenic global warming would infringe upon the rights of people in less-developed nations. As a consequence, this paper calls for a rethinking of FME approaches to climate change policy. (shrink)

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

I defend the permissibility of paid surrogacy arrangements against the arguments Sara Ketchum advances in " Selling Babies and Selling Bodies." I argue that the arrangements cannot be prohibited out of hand on the grounds that they treat persons as objects of sale, because it is possible to view the payments made in these arrangements as compensation for the woman ' s services. I also argue that the arguments based on exploitation and parental custodial rights fail to provide adequate grounds (...) for prohibiting the arrangements. (shrink)

Este artículo muestra el probable origen de las concepciones del desarrollo linear ascendente, cuyos representantes más conocidos en la era moderna fueron Hegel y Marx. En contraposición al concepto circular de la evolución histórica, que fue el predominante en muchas culturas, las doctrinas del des..

RESUMENUn intento por comprender la realidad sociopolítica podría consistir en situarse entre posiciones que marcan polos opuestos en el espectro de las ideas. Desde la filosofía griega se conocen las bondades y desventajas de colocarse en puntos intermedios que se hallan entre actitudes extremas en lo concerniente a asuntos morales y sociales. Una de las respuestas plausibles es una forma de eclecticismo, que tendría la función de una síntesis fructífera. Este teorema del sentido común guiado críticamente se asienta en concepciones (...) filosóficas clásicas, incluyendo la Escuela de Frankfurt. El ensayo pone como ejemplo principal el tratamiento de las utopías políticas.PLABARAS CLAVEARISTÓTELES, HABERMAS, HEGEL, SENTIDO COMÚN, TEORÍA CRÍTICA, UTOPÍAABSTRACTAn effort to understand the social-political reality could consist in taking a position between opposite poles in the spectrum of ideas. The advantages and disadvantages of placing oneself midway between extreme attitudes concerning moral and social problems have been aknowledged since Greek philosophy. A plausible answer is a form of eclecticism, which could have the function of a fertile synthesis. This theorem of a critically guided common sense is based on classic philosophic conceptions, including the Frankfurt School. This essay sets the analysis of political utopias as a main example.KEY WORDSARISTOTLE, COMMON SENSE, CRITICAL THEORY, UTOPY. (shrink)