UV detector monitors organic contamination of optical surfaces

Silicon carbide, insensitive to visible light, is used in photodetectors. System contamination can be monitored during the normal operation without interference to the operator, and without shielding from ambient light

Mammalian Septins Nomenclature

There are 10 known mammalian septin genes, some of which produce multiple splice variants. The current nomenclature for the genes and gene products is very confusing, with several different names having been given to the same gene product and distinct names given to splice variants of the same gene. Moreover, some names are based on those of yeast or Drosophila septins that are not the closest homologues. Therefore, we suggest that the mammalian septin field adopt a common nomenclature system, based on that adopted by the Mouse Genomic Nomenclature Committee and accepted by the Human Genome Organization Gene Nomenclature Committee. The human and mouse septin genes will be named SEPT1–SEPT10 and Sept1–Sept10, respectively. Splice variants will be designated by an underscore followed by a lowercase “v” and a number, e.g., SEPT4_v1

Distinct forebrain and cerebellar isozymes of type II Ca^(2+)/calmodulin-dependent protein kinase associate differently with the postsynaptic density fraction

Forebrain and cerebellar Type II Ca2+/calmodulin-dependent protein kinases have different subunit compositions. The forebrain holoenzyme, characterized in our laboratory, is a 650-kDa holoenzyme composed of 50-kDa alpha-subunits and 60-kDa beta-subunits assembled in approximately a 3:1 ratio (Bennett, M. K., Erondu, N. E., and Kennedy, M. B. (1983) J. Biol. Chem. 258, 12735-12744). The cerebellar isozyme is a 500-kDa holoenzyme composed of alpha-subunits and beta-subunits assembled in almost the converse ratio, approximately four beta-subunits for each alpha-subunit. When compared by tryptic peptide mapping and by immunochemical techniques, the beta-subunits from the two brain regions are indistinguishable and the alpha-subunits appear closely related. The specific activities, substrate specificities, and catalytic constants of the cerebellar and forebrain isozymes are similar, suggesting that the alpha- and beta-subunits contain similar catalytic sites. However, two differences in the properties of the isozymes may result in functional differences between them in vivo. First, the apparent affinity of the cerebellar kinase for Ca2+/calmodulin is 2-fold higher than that of the forebrain kinase. Second, the two isozymes appear to associate differently with subcellular structures. Approximately 85% of the cerebellar kinase and 50% of the forebrain kinase remain in the particulate fraction after homogenization under standard conditions. However, they are present in different amounts in postsynaptic density fractions. Postsynaptic densities prepared from forebrain contain the forebrain isozyme. Immunochemical measurements show that it comprises approximately 16% of their total protein. In contrast, postsynaptic densities prepared from cerebellum contain the cerebellar isozyme, but it comprises only approximately 1-2% of their total protein. Thus, the alpha-subunit may play a role in anchoring Type II Ca2+/calmodulin-dependent protein kinase to postsynaptic densities

Contribution of poor blood pressure control to strokes

No abstract available

Transforming fixed-length self-avoiding walks into radial SLE_8/3

We conjecture a relationship between the scaling limit of the fixed-length ensemble of self-avoiding walks in the upper half plane and radial SLE with kappa=8/3 in this half plane from 0 to i. The relationship is that if we take a curve from the fixed-length scaling limit of the SAW, weight it by a suitable power of the distance to the endpoint of the curve and then apply the conformal map of the half plane that takes the endpoint to i, then we get the same probability measure on curves as radial SLE. In addition to a non-rigorous derivation of this conjecture, we support it with Monte Carlo simulations of the SAW. Using the conjectured relationship between the SAW and radial SLE, our simulations give estimates for both the interior and boundary scaling exponents. The values we obtain are within a few hundredths of a percent of the conjectured values

Activation of type II calcium/calmodulin-dependent protein kinase by Ca^(2+)/calmodulin is inhibited by autophosphorylation of threonine within the calmodulin-binding domain

It is now well established that autophosphorylation of a threonine residue located next to each calmodulin-binding domain in the subunits of type II Ca^(2+)/calmodulin-dependent protein kinase causes the kinase to remain active, although at a reduced rate, after Ca^(2+) is removed from the reaction. This autophosphorylated form of the kinase is still sensitive to Ca2+/calmodulin, which is required for a maximum catalytic rate. After removal of Ca^(2+), new sites are autophosphorylated by the partially active kinase. Autophosphorylation of these sites abolishes sensitivity of the kinase to Ca^(2+)/calmodulin (Hashimoto, Y., Schworer, C. M., Colbran, R. J., and Soderling, T. R. (1987) J. Biol. Chem. 262, 8051-8055). We have identified two pairs of homologous residues, Thr^(305) and Ser^(314) in the alpha subunit and Thr^(306) and Ser^(315) in the beta subunit, that are autophosphorylated only after removal of Ca^(2+) from an autophosphorylation reaction. The sites were identified by direct sequencing of labeled tryptic phosphopeptides isolated by reverse-phase high pressure liquid chromatography. Thr^(305-306) is rapidly dephosphorylated by purified protein phosphatases 1 and 2A, whereas Ser^(314-315) is resistant to dephosphorylation. We have shown by selective dephosphorylation that the presence of phosphate on Thr^(305-306) blocks sensitivity of the kinase to Ca^(2+)/calmodulin. In contrast, the presence of phosphate on Ser^(314-315) is associated with an increase in the Kact for Ca^(2+)/calmodulin of only about 2-fold, producing a relatively small decrease in sensitivity to Ca^(2+)/calmodulin

Star - Planet - Debris Disk Alignment in the HD 82943 system: Is planetary system coplanarity actually the norm?

Recent results suggest that the two planets in the HD 82943 system are inclined to the sky plane by 20 +/- 4deg. Here, we show that the debris disk in this system is inclined by 27 +/- 4deg, thus adding strength to the derived planet inclinations and suggesting that the planets and debris disk are consistent with being aligned at a level similar to the Solar System. Further, the stellar equator is inferred to be inclined by 28 +/- 4deg, suggesting that the entire star - planet - disk system is aligned, the first time such alignment has been tested for radial velocity discovered planets on ~AU wide orbits. We show that the planet-disk alignment is primordial, and not the result of planetary secular perturbations to the disk inclination. In addition, we note three other systems with planets at >10AU discovered by direct imaging that already have good evidence of alignment, and suggest that empirical evidence of system-wide star - planet - disk alignment is therefore emerging, with the exception of systems that host hot Jupiters. While this alignment needs to be tested in a larger number of systems, and is perhaps unsurprising, it is a reminder that the system should be considered as a whole when considering the orientation of planetary orbits.Comment: Accepted to MNRA

Bending vibrational data accuracy study

Computer program for predicting structural bending vibrational dat

The Paraldor Project

Paraldor is an experiment in bringing the power of categorical languages to lattice QCD computations. Our target language is Aldor, which allows the capture of the mathematical structure of physics directly in the structure of the code using the concepts of categories, domains and their inter-relationships in a way which is not otherwise possible with current popular languages such as Fortran, C, C++ or Java. By writing high level physics code portably in Aldor, and implementing switchable machine dependent high performance back-ends in C or assembler, we gain all the power of categorical languages such as modularity, portability, readability and efficiency.Comment: 4 pages, 2 figures, Lattice 2002 conference proceeding