947 research outputs found

    Fate of specific ribonucleoside triphosphatases on purification and reconstitution of the ribosomal system of escherichia coli

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    Fate of specific ribonucleoside triphosphatases purification and reconstitution of ribosomal system of Escherichia col

    Phase Change Materials for Thermal Management of IC Packages

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    This paper deals with the application of phase change materials (PCM) for thermal management of integrated circuits as a viable alternative to active forced convection cooling systems. The paper presents an analytical description and solution of heat transfer, melting and freezing process in 1D which is applied to inorganic crystalline salts. There are also results of numerical simulation of a real 3D model. These results were obtained by means of the finite element method (FEM). Results of 3D numerical solutions were verified experimentally

    Performance characteristics of the 12 GHz, 200 watt transmitter experiment package for CTS

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    The experiment package consists of a 200 W output stage tube (OST) powered by a power processing system (PPS). Descriptions of both the PPS and OST are given. The PPS provides the necessary voltages with a measured dc/dc conversion efficiency of 89 percent. The OST, a traveling wave tube with multiple collectors, has a saturated rf output power of 224 W and operates at an overall efficiency exceeding 40 percent over an 85 MHz bandwidth at 12 GHz. OST performance given includes frequency response, saturation characteristics, group delay, AM to PM conversion, inter-modulation distortion, and two channel gain suppression. Single and dual channel FM video performance is presented. It was determined that for 12 MHz peak to peak frequency deviation on each channel, dual channel FM television signals can be transmitted through the TEP at 60 W, each channel, with 40 MHz channel spacing (center to center)

    Smart Institutions for Smart Cities

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    Smart cities employ creativity of the population for innovations supporting social and economic development. In this context, this paper explores the role of framework conditions on special supply effects of university hospitals, which can invite further research institutions for intense collaboration, thereby stimulating innovations. The case study, comparing a hospital in Russia with one in Germany, is based on the concept of the employment multiplier. The results show that exogenously given, but, more importantly, also modifiable framework conditions lead to large differences regarding the employment multiplier. Thus, it should be the concern of smart cities to make smart use of their institutions, such as university hospitals, by adjusting the conditions, under which they are operating. © 2018 Institute of Physics Publishing. All rights reserved

    Analysis of repetitive element DNA methylation by MethyLight

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    Repetitive elements represent a large portion of the human genome and contain much of the CpG methylation found in normal human postnatal somatic tissues. Loss of DNA methylation in these sequences might account for most of the global hypomethylation that characterizes a large percentage of human cancers that have been studied. There is widespread interest in correlating the genomic 5-methylcytosine content with clinical outcome, dietary history, lifestyle, etc. However, a high-throughput, accurate and easily accessible technique that can be applied even to paraffin-embedded tissue DNA is not yet available. Here, we report the development of quantitative MethyLight assays to determine the levels of methylated and unmethylated repeats, namely, Alu and LINE-1 sequences and the centromeric satellite alpha (Satα) and juxtacentromeric satellite 2 (Sat2) DNA sequences. Methylation levels of Alu, Sat2 and LINE-1 repeats were significantly associated with global DNA methylation, as measured by high performance liquid chromatography, and the combined measurements of Alu and Sat2 methylation were highly correlative with global DNA methylation measurements. These MethyLight assays rely only on real-time PCR and provide surrogate markers for global DNA methylation analysis. We also describe a novel design strategy for the development of methylation-independent MethyLight control reactions based on Alu sequences depleted of CpG dinucleotides by evolutionary deamination on one strand. We show that one such Alu-based reaction provides a greatly improved detection of DNA for normalization in MethyLight applications and is less susceptible to normalization errors caused by cancer-associated aneuploidy and copy number changes

    The marine myxosporean Sigmomyxa sphaerica (Thélohan, 1895) gen. n., comb. n. (syn. Myxidium sphaericum) from garfish (Belone belone (L.)) uses the polychaete Nereis pelagica L. as invertebrate host

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    Sigmomyxa sphaerica (Thélohan, 1892) gen. n. (Myxozoa, Myxosporea) with myxosporean stages in the gall bladder of Belone belone (L.) (Teleostei, Belonidae) uses the polychaete Nereis pelagica L. (Nereidae) from shallow water in the northern Øresund, Denmark, as invertebrate host. The nearly spherical tetractinomyxon-type actinospores of S. sphaerica differ from those of two species of Ellipsomyxa which also use Nereis spp. as invertebrate host. Pansporocysts of S. sphaerica were not seen. S. sphaerica is redescribed on the basis of myxospore stages from B. belone and actinospores from N. pelagica, and the phylogenetic affinities examined on the basis of ribosomal small subunit gene sequences. S. sphaerica is closest related to Ellipsomyxa spp., and is not congeneric with morphologically similar Myxidium spp. from gadids. This is the fifth elucidated two-host life cycle of a marine myxozoan

    Kidins220/ARMS binds to the B cell antigen receptor and regulates B cell development and activation

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    B cell antigen receptor (BCR) signaling is critical for B cell development and activation. Using mass spectrometry, we identified a protein kinase D\u2013interacting substrate of 220 kD (Kidins220)/ankyrin repeat\u2013rich membrane-spanning protein (ARMS) as a novel interaction partner of resting and stimulated BCR. Upon BCR stimulation, the interaction increases in a Src kinase\u2013independent manner. By knocking down Kidins220 in a B cell line and generating a conditional B cell\u2013specific Kidins220 knockout (B-KO) mouse strain, we show that Kidins220 couples the BCR to PLC\u3b32, Ca2+, and extracellular signal-regulated kinase (Erk) signaling. Consequently, BCR-mediated B cell activation was reduced in vitro and in vivo upon Kidins220 deletion. Furthermore, B cell development was impaired at stages where pre-BCR or BCR signaling is required. Most strikingly, \u3bb light chain\u2013positive B cells were reduced sixfold in the B-KO mice, genetically placing Kidins220 in the PLC\u3b32 pathway. Thus, our data indicate that Kidins220 positively regulates pre-BCR and BCR functionin

    The Rest-frame Optical Colors of 99,000 SDSS Galaxies

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    We synthesize the rest-frame Stroemgren colors using SDSS spectra for 99,088 galaxies selected from Data Release 1. This narrow-band ~200 AA photometric system (uz, vz, bz, yz), first designed for the determination of effective temperature, metallicity and gravity of stars, measures the continuum spectral slope of galaxies in the rest-frame 3200-5800 AA wavelength range. Galaxies form a remarkably narrow locus (~0.03 mag) in the resulting color-color diagram. The Bruzual & Charlot population synthesis models suggest that the position of a galaxy along this locus is controlled by a degenerate combination of metallicity and age of the dominant stellar population. Galaxy distribution along the locus is bimodal, with the local minimum corresponding to an ~1 Gyr old single stellar population. The position perpendicular to the locus is independent of metallicity and age, and reflects the galaxy's dust content, as implied by both the models and the statistics of IRAS detections. A comparison of this locus with the galaxy locus in the H_delta-D_n(4000) diagram, utilized by Kauffmann et al. (2003) to estimate stellar masses, reveals a tight correlation, although the two analyzed spectral ranges barely overlap. Overall, the galaxy spectral energy distribution in the entire UV to near-IR range can be described as a single-parameter family with an accuracy of 0.1 mag, or better. This nearly one-dimensional distribution of galaxies in the multi-dimensional space of measured parameters strongly supports the conclusion of Yip et al. (2004), based on a principal component analysis, that SDSS galaxy spectra can be described by a small number of eigenspectra. Apparently, the contributions of stellar populations that dominate the optical emission from galaxies are combined in a simple and well-defined way.Comment: Accepted for publication in MNRAS; 19 pages, 28 color figure

    Planar Graph Coloring with Forbidden Subgraphs: Why Trees and Paths Are Dangerous

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    We consider the problem of coloring a planar graph with the minimum number of colors such that each color class avoids one or more forbidden graphs as subgraphs. We perform a detailed study of the computational complexity of this problem. We present a complete picture for the case with a single forbidden connected (induced or non-induced) subgraph. The 2-coloring problem is NP-hard if the forbidden subgraph is a tree with at least two edges, and it is polynomially solvable in all other cases. The 3-coloring problem is NP-hard if the forbidden subgraph is a path, and it is polynomially solvable in all other cases. We also derive results for several forbidden sets of cycles
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