1,594 research outputs found

    Localizing Gravitational Wave Sources with Single-Baseline Atom Interferometers

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    Localizing sources on the sky is crucial for realizing the full potential of gravitational waves for astronomy, astrophysics, and cosmology. We show that the mid-frequency band, roughly 0.03 to 10 Hz, has significant potential for angular localization. The angular location is measured through the changing Doppler shift as the detector orbits the Sun. This band maximizes the effect since these are the highest frequencies in which sources live several months. Atom interferometer detectors can observe in the mid-frequency band, and even with just a single baseline can exploit this effect for sensitive angular localization. The single baseline orbits around the Earth and the Sun, causing it to reorient and change position significantly during the lifetime of the source, and making it similar to having multiple baselines/detectors. For example, atomic detectors could predict the location of upcoming black hole or neutron star merger events with sufficient accuracy to allow optical and other electromagnetic telescopes to observe these events simultaneously. Thus, mid-band atomic detectors are complementary to other gravitational wave detectors and will help complete the observation of a broad range of the gravitational spectrum.Comment: 16 pages, 3 figures, 2 table

    bZIPDB : A database of regulatory information for human bZIP transcription factors

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    <p>Abstract</p> <p>Background</p> <p>Basic region-leucine zipper (bZIP) proteins are a class of transcription factors (TFs) that play diverse roles in eukaryotes. Malfunctions in these proteins lead to cancer and various other diseases. For detailed characterization of these TFs, further public resources are required.</p> <p>Description</p> <p>We constructed a database, designated bZIPDB, containing information on 49 human bZIP TFs, by means of automated literature collection and manual curation. bZIPDB aims to provide public data required for deciphering the gene regulatory network of the human bZIP family, e.g., evaluation or reference information for the identification of regulatory modules. The resources provided by bZIPDB include (1) protein interaction data including direct binding, phosphorylation and functional associations between bZIP TFs and other cellular proteins, along with other types of interactions, (2) bZIP TF-target gene relationships, (3) the cellular network of bZIP TFs in particular cell lines, and (4) gene information and ontology. In the current version of the database, 721 protein interactions and 560 TF-target gene relationships are recorded. bZIPDB is annually updated for the newly discovered information.</p> <p>Conclusion</p> <p>bZIPDB is a repository of detailed regulatory information for human bZIP TFs that is collected and processed from the literature, designed to facilitate analysis of this protein family. bZIPDB is available for public use at <url>http://biosoft.kaist.ac.kr/bzipdb</url>.</p

    λ‚˜μ΄μ— λ”°λ₯Έ 얕은 μˆ˜λ©΄μ—μ„œμ˜ μ •μˆ˜λ¦¬ νŒŒν˜•μ˜ νŠΉμ§•

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    The significance of sleep disorders is underestimated in our society. The number of sleep disorders is over 80 in recent classifications of sleep disorders. And the incidence and prevalence of sleep disorders are very high compared to other medical illnesses. The consequences of sleep disorders such as medical illness, surgical illness, and accident may cause serious burden not only to our individual health but also to our society both medically and socioeconomically. By reviewing economical cost of sleep disorders, we can see the seriousness of this condition and can find out what to do for the improvement to better condition.OAIID:oai:osos.snu.ac.kr:snu2012-01/102/2014017262/12SEQ:12PERF_CD:SNU2012-01EVAL_ITEM_CD:102USER_ID:2014017262ADJUST_YN:NEMP_ID:A079623DEPT_CD:801CITE_RATE:0DEPT_NM:μ˜ν•™κ³ΌSCOPUS_YN:NCONFIRM:

    Identification of replicative senescence-associated genes in human umbilical vein endothelial cells by an annealing control primer system

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    Cellular senescence is regulated by specific genes in many organisms. The identification and functional analysis of senescence-associated genes could provide valuable insights into the senescence process. Here, we employed a new and improved differential display reverse transcription-polymerase chain reaction (DDRT-PCR) method that involves annealing control primers (ACPs) to identify genes that are differentially expressed in human umbilical endothelial cells during replicative senescence. Using 120 ACPs, we identified 31 differentially expressed genes (DEGs). Basic local alignment search tool (BLAST) search revealed 29 known genes and two unknown genes. Expression levels of the 29 known genes were confirmed by real-time quantitative RT-RCR and by Western blotting for eight of these genes. CD9 antigen, MHC class I chain-related sequence A (MICA) and cell division cycle 37 homolog (CDC37) were up-regulated, and bone morphogenetic protein 4 (BMP4), dickkopf-1 (DKK1), and transcription factor 7-like 1 (TCF7L1) were down-regulated in old cells. Treatment with recombinant human MICA caused a decrease in cell proliferation and an increase in senescence-associated beta-galactosidase staining. Further analysis of differentially expressed genes may provide insights into the molecular basis of replicative senescence and vascular diseases associated with cellular senescence

    A novel de novo mutation in the serine-threonine kinase STK11 gene in a Korean patient with Peutz-Jeghers syndrome

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    BACKGROUND: Peutz-Jeghers syndrome (PJS) is an unusual autosomal dominant disorder characterized by mucocutaneous pigmentation and multiple gastrointestinal hamartomatous polyps. Patients with PJS are at an increased risk of developing multi-organ cancer, most frequently those involving the gastrointestinal tract. Germline mutation of the STK11 gene, which encodes a serine-threonine kinase, is responsible for PJS. METHODS: Using DNA samples obtained from the patient and his family members, we sequenced nine exons and flanking intron regions of the STK11 gene using polymerase chain reaction (PCR) and direct sequencing. RESULTS: Sequencing of the STK11 gene in the proband of the family revealed a novel 1-base pair deletion of guanine (G) in exon 6 (c.826delG; Gly276AlafsX11). This mutation resulted in a premature termination at codon 286, predicting a partial loss of the kinase domain and complete loss of the C-terminal domain. We did not observe this mutation in both parents of the PJS patient. Therefore, it is considered a novel de novo mutation. CONCLUSION: The results presented herein enlarge the spectrum of mutations of the STK11 gene by identifying a novel de novo mutation in a PJS patient and further support the hypothesis that STK11 mutations are disease-causing mutations for PJS with or without a positive family history

    Phylogeny and Genetic/Morphological Variation of Strombidinopsis minima-like Species (Ciliophora: Choreotrichia).

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    Six isolates of mineral-enveloped Strombidinopsis minima-like species were collected from the coastal waters across several regions in Korea. Morphological observations and molecular analyses were performed. The ribosomal DNA sequences (including small subunit ribosomal DNA, internal transcriber spacer 1-5.8S ribosomal DNA-internal transcriber spacer 2; and part of large subunit ribosomal DNA) of these six isolates were compared. Their morphological characteristics were also compared with those of S. minima populations reported. The marked genetic differences (with a similarity range of 96.85-98.48%) in SSU rDNA among these S. minima-like entities suggest the existence of multiple species. This finding is also supported by morphological variations detected in this study and reported in the literature (e.g. 15-32 collar membranelles in different populations). In addition, S. minima-like species are clustered with S. batos and S. sinicum, and therefore, our SSU rDNA results support previous results suggesting that the genus Strombidinopsis is not monophyletic in origin. Further collection of morphological and molecular data may facilitate the determination of a new genus carrying mineral-enveloped Strombidinopsis species

    Role of Amphipathic Helix of a Herpesviral Protein in Membrane Deformation and T Cell Receptor Downregulation

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    Lipid rafts are membrane microdomains that function as platforms for signal transduction and membrane trafficking. Tyrosine kinase interacting protein (Tip) of T lymphotropic Herpesvirus saimiri (HVS) is targeted to lipid rafts in T cells and downregulates TCR and CD4 surface expression. Here, we report that the membrane-proximal amphipathic helix preceding Tip's transmembrane (TM) domain mediates lipid raft localization and membrane deformation. In turn, this motif directs Tip's lysosomal trafficking and selective TCR downregulation. The amphipathic helix binds to the negatively charged lipids and induces liposome tubulation, the TM domain mediates oligomerization, and cooperation of the membrane-proximal helix with the TM domain is sufficient for localization to lipid rafts and lysosomal compartments, especially the mutivesicular bodies. These findings suggest that the membrane-proximal amphipathic helix and TM domain provide HVS Tip with the unique ability to deform the cellular membranes in lipid rafts and to downregulate TCRs potentially through MVB formation
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