The main goal of the paper is to present an objection to the mental files framework. Alongside being representational resources that the mind exploits when having attitudes concerning particulars, many philosophers have explored the idea that singular concepts can serve another function: that of storing alleged information about their referents. In other words, singular concepts are characterized as mental files. Given that the latter implies an overwhelming and unnecessary complication of what’s in our minds, I argue that we should only (...) keep the representational function of concepts. The work files are supposed to do, I claim, can be exported to other aspects of the cognitive system. (shrink)

In this article, we defend the existence of disagreements in areas of discourse that involve anagent’s perspective, as the semantic theory known as “Radical Relativism” putsit. In the face of the idea that such disagreements exist and can only be explainedby a radical relativist semantics, contextualist theorists have offered arguments to deny their existence or to provide an explanation of them which does not imply departing from the standard semantic theory. These arguments will be our targetof criticism. We raise the (...) debate in terms of the distinction between semantic andpragmatic aspects of disagreement, and we defend a simple vision of disagreement, which we believe the relativist must have in mind if he wants to argue that disagreements belonging to areas that involve an agent’s perspective can count as evidence in his favor. (shrink)

Recent progress in our understanding of mitotic chromosome dynamics has been accelerated by the identification of two essential protein complexes, cohesin and condensin. Cohesin is required for holding sister chromatids (duplicated chromosomes) together from S phase until the metaphase‐to‐anaphase transition. Condensin is a central player in chromosome condensation, a process that initiates at the onset of mitosis. The main focus of this review is to discuss how the mitotic metaphase chromosome is assembled and shaped by a precise balance between the (...) cohesion and condensation machineries. We argue that, in different eukaryotic organisms, the balance of cohesion and condensation is adjusted in such a way that the size and shape of the resulting chromosomes are best suited for their accurate segregation. BioEssays 23:924–935, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Sister chromatid cohesion mediated by the ring‐shaped cohesin complex is essential for faithful chromosome segregation. A tight spatial and temporal control of cohesin release is observed in mitosis and meiosis, and a family of proteins known as shugoshins play a major role in this process. Shugoshin (Sgo) protects centromeric cohesin from dissociation in early mitosis and from cleavage by separase in meiosis I. Three exciting new reports indicate that this is accomplished by recruiting the serine/threonine protein phosphatase 2A (PP2A) to (...) centromeres.(1–3) The proposed targets of PP2A activity include cohesin and Sgo, both of which would otherwise dissociate from chromosomes upon phosphorylation by Polo kinase. Thus, a balance of kinase and phosphatase activities seems to be the key to the conserved mechanism that regulates the stepwise release of cohesin from mitotic and meiotic chromosomes. Additional evidence, however, suggests that this is only part of the story, and that Sgo has also a role independent of PP2A. BioEssays 28: 775–779, 2006. © 2006 Wiley Periodicals, Inc. (shrink)