Varieties of Ontological Argument

I consider what I hope are increasingly sophisticated versions of ontological argument, beginning from simple definitional forms, through three versions to be found in Anselm, with their recent interpretations by Malcolm, Plantinga, Klima and Lowe. I try to show why none of these work by investigating both the different senses of necessary existence and the conditions under which logically necessary existence can be brought to bear. Although none of these arguments work, I think that they lead to interesting reflections on the nature of definition, on the conditions for possessing the property of necessary existence and point towards a different, neo-Platonic ground for God’s meeting the criteria for being logically necessary

A ’Trinitarian’ Theory of the Self

I argue that the self is simple metaphysically, whilst being complex psychologically and that the persona that links these moments might be dubbed ”creativity’ or ”imagination’. This theory is trinitarian because it ascribes to the self these three ”features’ or ”moments’ and they bear at least some analogy with the Persons of the Trinity, as understood within the neo- platonic, Augustinian tradition

Operator-Valued Frames for the Heisenberg Group

A classical result of Duffin and Schaeffer gives conditions under which a discrete collection of characters on $\mathbb{R}$, restricted to $E = (-1/2, 1/2)$, forms a Hilbert-space frame for $L^2(E)$. For the case of characters with period one, this is just the Poisson Summation Formula. Duffin and Schaeffer show that perturbations preserve the frame condition in this case. This paper gives analogous results for the real Heisenberg group $H_n$, where frames are replaced by operator-valued frames. The Selberg Trace Formula is used to show that perturbations of the orthogonal case continue to behave as operator-valued frames. This technique enables the construction of decompositions of elements of $L^2(E)$ for suitable subsets $E$ of $H_n$ in terms of representations of $H_n$

Are Our Institutions Flexible Enough?

The true aim of our Government is freedom and equality for our citizens. The Government assumes the role of big brother, arbiter, innovator, and, finally, conciliator over all our many free insti­tutions

The Molecular Basis for Different Recognition of Substrates by Phosphodiesterase Families 4 and 10

Phosphodiesterases (PDEs) are key enzymes that control the cellular concentrations of the second messengers cAMP and cGMP. The mechanism for selective recognition of substrates cAMP and cGMP by individual PDE families remains a puzzle. To understand the mechanism for substrate recognition by PDE enzymes, the crystal structure of the catalytic domain of an inactive D201N mutant of PDE4D2 in complex with substrate cAMP has been determined at 1.56 Å resolution. The structure shows that Gln369 forms only one hydrogen bond with the adenine of cAMP. This finding provides experimental evidence against the hypothesis of two hydrogen bonds between the invariant glutamine and the substrate cAMP in PDE4, and thus suggests that the widely circulated “glutamine switch” model is unlikely the mechanism for substrate recognition by PDEs. A structure comparison between PDE4D2-cAMP and PDE10A2-cAMP reveals an anti configuration of cAMP in PDE4D2 but syn in PDE10A2, in addition to different contact patterns of cAMP in these two structures. These observations imply that individual PDE families have their characteristic mechanisms for substrate recognition

Expression, Purification, Crystallization and Preliminary X-Ray Analysis of \u3cem\u3ePseudomonas aeuginosa\u3c/em\u3e AlgX

AlgX is a periplasmic protein required for the production of the exopolysaccharide alginate in Pseudomonas sp. and Azotobacter vinelandii. AlgX has been overexpressed and purified and diffraction-quality crystals have been grown using iterative seeding and the hanging-drop vapor-diffusion method. The crystals grew as flat plates with unit-cell parameters a=46.4, b=120.6, c=86.9Å, β=95.7°. The cyrstals exhibited the symmetry of space group P21 and diffracted to a minimimum d-spacing of 2.1Å. On the basis of the Matthews coefficient (VM=2.25Å3 Da-1), two molecules were estimated to be present in the asymmetric unit

Why phenomenal content is not intentional

I argue that the idea that mental states possess a primitive intentionality in virtue of which they are able to represent or ‘intend’ putative particulars derives largely from Brentano‘s misinterpretation of Aristotle and the scholastics, and that without this howler the application of intentionality to phenomenal content would never have gained currency

Cellular expression and crystal structure of the murine cytomegalovirus MHC-Iv glycoprotein, m153

Mouse cytomegalovirus (MCMV), a β-herpesvirus that establishes latent and persistent infections in mice, is a valuable model for studying complex virus-host interactions. MCMV encodes the m145 family of putative immunoevasins with predicted MHC-I structure. Functions attributed to some family members include downregulation of host MHC-I (m152) and NKG2D ligands (m145, m152, m155) and interaction with inhibitory or activating NK receptors (m157). We present the cellular, biochemical and structural characterization of m153, which is a heavily glycosylated homodimer, that does not require β2m or peptide, and is expressed at the surface of MCMV-infected cells. Its 2.4 Å crystal structure confirms that this compact molecule preserves an MHC-I-like fold and reveals a novel mode of dimerization, confirmed by site-directed mutagenesis, and a distinctive disulfide-stabilized extended amino terminus. The structure provides a useful framework for comparative analysis of the divergent members of the m145 family