414 research outputs found
Presentism and the flow of time
The paper examines the relations between presentism and the thesis concerning the existence of the ïŹow of time. It tries to show that the presentist has to admit the existence of the passage of time and that the standard formulation of presentism as a singular thesis saying that only the present exists is insufïŹcient because it does not allow the inference of the existence of the passage of time. Instead of this, the paper proposes a formulation of presentism with the aid of the notion of becoming; not only does a formulation state the existence of the ïŹow of time in such a way as to avoid the question of the rate of the passage of time, it also allows the inference of the existence of only present things and events. The paper demonstrates that the proposed conception of presentism also has other virtues, such as homogeneity, non-triviality, and ability to express dynamicity of presentistsâ image of the world which testify for it
Vagueness and Quantification
This paper deals with the question of what it is for a quantifier expression to be vague. First it draws a distinction between two senses in which quantifier expressions may be said to be vague, and provides an account of the distinction which rests on independently grounded assumptions. Then it suggests that, if some further assumptions are granted, the difference between the two senses considered can be represented at the formal level. Finally, it outlines some implications of the account provided which bear on three debated issues concerning quantification
Improving model quality through foundational ontologies: Two contrasting approaches to the representation of roles
Several foundational ontologies have been developed recently. We examine two of these from the point of view of their quality in representing temporal changes, focusing on the example of roles. We discuss how these are modelled in two foundational ontologies: the Unified Foundational Ontology and the BORO foundational ontology. These exhibit two different approaches, endurantist and perdurantist respectively. We illustrate the differences using a running example in the university student domain, wherein one individual is not only a registered student but also, for part of this period, was elected the President of the Student Union. The metaphysical choices made by UFO and BORO lead to different representations of roles. Two key differences which affect the way roles are modelled are exemplified in this paper: (1) different criteria of identity and (2) differences in the way individual objects extend over time and possible worlds. These differences impact upon the quality of the models produced in terms of their respective explanatory power. The UFO model concentrates on the notion of validity in âall possible worldsâ and is unable to accurately represent the way particulars are extended in time. The perdurantist approach is best able to describe temporal changes wherein roles are spatio-temporal extents of individuals
Bound States and the Special Composition Question
The Special Composition Question asks under what conditions a plurality of objects form another, composite object. We propose a condition grounded in our scientific knowledge of physical reality, the essence of which is that objects form a composite object when and only when they are in a bound state â whence our Bound State Proposal. We provide a variety of reasons in favour of a mereological theory that accommodates our Proposal. We consider but reject another proposal, which is quantum-physical in nature: the Entanglement Proposal. We close by responding to Tellerâs âSuit Objectionâ
Realism, Objectivity, and Evaluation
I discuss Benacerraf's epistemological challenge for realism about areas like mathematics, metalogic, and modality, and describe the pluralist response to it. I explain why normative pluralism is peculiarly unsatisfactory, and use this explanation to formulate a radicalization of Moore's Open Question Argument. According to the argument, the facts -- even the normative facts -- fail to settle the practical questions at the center of our normative lives. One lesson is that the concepts of realism and objectivity, which are widely identified, are actually in tension
Small ruminant lentivirus genetic subgroups associate with sheep TMEM154 genotypes.
Abstract: Small ruminant lentiviruses (SRLVs) are prevalent in North American sheep and a major cause of production losses for the U.S. sheep industry. Sheep susceptibility to SRLV infection is influenced by genetic variation within the ovine transmembrane 154 gene (TMEM154). Animals with either of two distinct TMEM154 haplotypes that both encode glutamate at position 35 of the protein (E35) are at greater risk of SRLV infection than those homozygous with a lysine (K35) haplotype. Prior to this study, it was unknown if TMEM154 associations with infection are influenced by SRLV genetic subgroups. Accordingly, our goals were to characterize SRLVs naturally infecting sheep from a diverse U.S. Midwestern flock and test them for associations with TMEM154 E35K genotypes. Two regions of the SRLV genome were targeted for proviral amplification, cloning, sequence analysis, and association testing with TMEM154 E35K genotypes: gag and the transmembrane region of env. Independent analyses of gag and env sequences showed that they clustered in two subgroups (1 and 2), they were distinct from SRLV subtypes originating from Europe, and that subgroup 1 associated with hemizygous and homozygous TMEM154 K35 genotypes and subgroup 2 with hemi- and homozygous E35 genotypes (gag p < 0.001, env p = 0.01). These results indicate that SRLVs in the U.S. have adapted to infect sheep with specific TMEM154 E35K genotypes. Consequently, both host and SRLV genotypes affect the relative risk of SRLV infection in sheep
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