Tumor necrosis factor receptor (TNFR)-associated factor 2A (TRAF2A), a TRAF2 splice variant with an extended RING finger domain that inhibits TNFR2-mediated NF-kappaB activation

We describe here the identification and characterization of tumor necrosis factor receptor (TNFR)-associated factor 2A (TRAF2A), a splice variant of the TRAF2 molecule utilized for signal transduction by members of the TNFR family. TRAF2A and TRAF2 cDNAs are identical in sequence with the exception of an extra 21 base pairs of sequence encoding a 7-amino acid insert within the TRAF2A RING finger domain. TRAF2A mRNA expression is regulated in a tissue-specific manner, with relative TRAF2A mRNA levels being highest in spleen and lowest in brain. TRAF2A protein is capable of binding to the cytoplasmic domain of TNFR2 (p75) and is detectable in T-lymphoma cells stably transfected with the TRAF2A cDNA. Unlike TRAF2, TRAF2A has a short half-life ( approximately 100 min) in these cells and is expressed at only low levels in transiently transfected COS-7 cells. However, TRAF2A levels in transiently transfected COS-7 cells approach those of TRAF2 upon coexpression with TRAF1 and/or TRAF2, indicating that TRAF2A stability is regulated by the binding of other TRAF family proteins. Also in contrast to TRAF2, TRAF2A is unable to stimulate NF-kappaB activity when overexpressed in 293 cells and acts as a dominant inhibitor of TNFR2-dependent NF-kappaB activation. TRAF2A thus represents a novel signal transduction protein, the expression of which can act to inhibit TRAF2-dependent NF-kappaB activation.     

The Impact of Stoichiometry on the Photophysical Properties of Ruddlesden–Popper Perovskites

2D Ruddlesden–Popper perovskites are interesting for a variety of applications owing to their tunable optical properties and their excellent ambient stability. As these materials are processable from solution, they hold the promise of procuring flexible and cost‐effective films through large‐scale fabrication techniques. However, such solution‐based deposition techniques often induce large degrees of heterogeneity due to poorly controlled crystallization. The microscopic properties of films of (PEA)₂PbI₄ cast from precursor solutions of different stoichiometry are therefore investigated. The stoichiometry of the precursor solution is found to have a large impact on the crystallinity, morphology, and optical properties of the resulting thin films. Even for films cast from stoichiometric precursors, differences in photoluminescence intensities occur on a subgranular level. The heterogeneity in these films is found to be thermally activated with an activation energy of 0.4 eV for the emergence of local variations in nonradiative recombination rates. The spatial variation in the distribution of trap states is attributed to local fluctuations in the stoichiometry. In line with this, the surface can successfully be passivated by providing an excess of phenylethylammonium iodide (PEAI) to an as‐cast film, enhancing the photoluminescence by as much as 85% without significantly altering the film's morphology.     

Present Status of the SuperCDMS program

The expected final reach of the Weakly Interacting Massive Particle (WIMP) search experiment CDMS-II by the end of 2007 is a WIMP-nucleon cross-section sensitivity of 2.1×10⁻⁴⁴ cm². To proceed further in our search, we have proposed the SuperCDMS Phase A project that would deploy 42 1-inch thick Ge detectors, at a site deeper than the location of CDMS II, and reach a desired sensitivity goal of 1.3×10⁻⁴⁵ cm². These cross-sections are of interest and are complementary to Supersymmetry searches at the Large Hadron Collider (LHC) and future linear colliders. P.L. Brink for the SuperCDMS Collaboration.     

Visualization of colorectal polyps with spiral CT colography: evaluation of processing parameters with perspective volume rendering

PURPOSE: To evaluate two key processing steps for detection of colon polyps with spiral computed tomographic (CT) colography with perspective volume rendering (PVR): image reconstruction and opacity assignment of the attenuation data. MATERIALS AND METHODS: Spiral CT was performed in 10 patients with known polyps confirmed at colonoscopy, and detailed quantitative analyses were performed of data obtained in four. First, anatomic fidelity of three-dimensional (3D) images generated from two-dimensional (2D) source images with equal voxel dimensions (87%-90% overlap) was compared with 3D images generated from 2D source images with unequal voxel dimensions (0%-80% overlap). Next, the relative dimensions of colorectal polyps to adjacent structures were evaluated for various opacity threshold settings. Then, step and sigmoidal opacity functions were compared with respect to image smoothness and edge sharpness. RESULTS: PVR images generated after interpolation of image data reconstructed with at least 60% overlap were equivalent in image quality to PVR images generated from source images with equal voxel dimensions. Relative polyp-to-haustral fold dimensions demonstrated substantial distortions with opacity thresholds below -700 HU. The 3D PVR images generated with the sigmoidal opacity function were significantly smoother than those generated with the step opacity function (paired t test, P < .02), with small differences noted in edge sharpness. CONCLUSION: Use of highly overlapping source images (87%-90%) was not necessary to generate 3D PVR images of colorectal polyps. Image artifacts were suppressed with use of an appropriate opacity threshold and a sigmoidal opacity function without substantial loss in edge sharpness.     

Ionization Measurements of SuperCDMS SNOLAB 100 mm Diameter Germanium Crystals

Scaling cryogenic Germanium-based dark matter detectors to probe smaller WIMP-nucleon cross-sections poses significant challenges in the forms of increased labor, cold hardware, warm electronics and heat load. The development of larger crystals alleviates these issues. The results of ionization tests with two 100?mm diameter, 33?mm thick cylindrical detector-grade Germanium crystals are presented here. Through these results the potential of using such crystals in the Super Cryogenic Dark Matter Search (SuperCDMS) SNOLAB experiment is demonstrated.     

Copolymerization behavior of 3-isopropenyl-α,α-dimethylbenzylamine and a preliminary evaluation of the copolymers in thermoset coatings

The title monomer was synthesized from 3-isopropenyl-α,α-dimethylbenzyl isocyanate in a significantly better yield than was previously reported. 3-Isopropenyl-α,α-dimethylbenzylamine proved incapable of homopolymerization using free-radical initiation but readily copolymerized with a variety of commonly available monomers under free-radical conditions. Films of some of the copolymers were prepared and crosslinked using a variety of multifunctional epoxy compounds. The films had good solvent resistance, high hardness, and good gloss. © 2001 John Wiley & Sons, Inc. J Appl Polym Sci 82: 1030–1039;2001     

The origins of Dutch rural planning: a study of the early history of land consolidation in the Netherlands

This article explores the institutional and organizational foundations of rural planning in the Netherlands. The key objective of the study was to understand the background to and determining factors in the development of land consolidation (ruilverkaveling) as an instrument of rural planning. Dutch rural planning, as a constituent part of spatial planning in the Netherlands, developed quite separately from urban planning. This article traces the roots of this separate development back to the period 1890–1940. At the end of the nineteenth century, reformist liberals argued for a legislative framework for the rational reallocation of land parcels to consolidate fragmented land holdings. The early initiatives came to nothing because of the prevailing rigid distinction between public and private interests. The First World War changed this situation. The decline in world trade forced the government to make the national economy more self‐sufficient. Land consolidation was embraced as a means for supporting the agricultural sector by improving land drainage and bringing land into cultivation. From the beginning of the 1930s agricultural politics and rural planning grew closer together, and took off rapidly in the post‐war decades.