5,869 research outputs found
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 Godâs meeting the criteria for being logically necessary
A âTrinitarianâ 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 âcreativityâ or âimaginationâ. This theory is trinitarian because it ascribes to the self these three âfeaturesâ or âmomentsâ 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 , restricted to , forms a Hilbert-space frame for . 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 , 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 for suitable subsets of in
terms of representations of
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 instiÂtutions
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 â« 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 âglutamine switchâ 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=86.9Ă
, ÎČ=95.7°. The cyrstals exhibited the symmetry of space group P21 and diffracted to a minimimum d-spacing of 2.1Ă
. On the basis of the Matthews coefficient (VM=2.25Ă
3 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 âintendâ putative particulars derives largely from Brentanoâs misinterpretation of Aristotle and the scholastics, and that without this howler the application of intentionality to phenomenal content would never have gained currency
- âŠ