218 research outputs found

    Microbial biomass in relation to primary succession on arctic deglaciated moraines

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    Microbial biomass in arctic soil was examined in relation to a primary succession on arctic deglaciated moraines in Ny-Alesund, Svalbard (79°N, 12°E). Soil samples at four study sites representing different successional stages were collected at every 1cm depth from the soil surface to 3cm depth in early August 1995. Microbial biomass was measured with a substrate-induced respiration procedure. The microbial biomass was highest at the soil surface (0-1cm depth) in all successional stages, and decreased to a negligible amount at 3cm depth. Mean microbial biomass in 0-2cm layer increased from 0.06mgCg^ soil d. w. in the youngest site to 1.03mgC g^ soil d. w. in the oldest site, which is comparable to ecosystems in warmer regions. Throughout all successional stages, there was positive high correlation between soil carbon or nitrogen content and microbial biomass

    Soil respiration in a high arctic glacier foreland in Ny-Alesund, Svalbard

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    Soil respiration rates were measured in a successional glacier foreland in Ny-_lesund, Svalbard, and the amount of CO2 efflux during the plant-growing season was estimated using a simple regression model. Three study sites (Site 1, Site 2 and Site 3) were set up along with the primary succession in the deglaciated area of East Br_gger glacier in Ny-_lesund, Svalbard, Norway (79‹N 12‹E). Another study site, Site RB, was set up on a riverbed in the Bay River between Site 2 and Site 3. Soil respiration (SR), air temperature at 10 cm height (AT), soil surface temperature (SST) and soil temperature at 1 cm depth (ST) were measured at the four study sites with an open-airflow system using an infra-red gas analyzer from July to August, 1995. The mean soil respiration rate varied among the four sites: 6.2, 44, 63 and 3.7 mg CO2 m-2 h-1 at Site 1, Site 2, Site 3 and Site RB, respectively. These differences in the soil respiration rate among the four sites corresponded with the soil organic amount, microbial biomass, and root biomass. The soil respiration rate showed the best correlation with AT at Site 1, Site 2 and Site RB, and with ST at Site 3. The cumulative amount of CO2 efflux calculated using correlation equations obtained from the above relationships between SR and AT or ST was 5.8, 46, 69 and 3.3 g CO2 m-2 at Site 1, Site 2, Site 3 and Site RB, respectively, for two months (from July to August, 1995). These values were extremely low compared to those of warmer ecosystems, such as low-arctic tundra, temperate mixed forests, and tropical moist forests

    First Results of Axion Dark Matter Search with DANCE

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    Axions are one of the well-motivated candidates for dark matter, originally proposed to solve the strong CP problem in particle physics. Dark matter Axion search with riNg Cavity Experiment (DANCE) is a new experimental project to broadly search for axion dark matter in the mass range of 1017 eV<ma<1011 eV10^{-17}~\mathrm{eV} < m_a < 10^{-11}~\mathrm{eV}. We aim to detect the rotational oscillation of linearly polarized light caused by the axion-photon coupling with a bow-tie cavity. The first results of the prototype experiment, DANCE Act-1, are reported from a 24-hour observation. We found no evidence for axions and set 95% confidence level upper limit on the axion-photon coupling gaγ8×104 GeV1g_{a \gamma} \lesssim 8 \times 10^{-4}~\mathrm{GeV^{-1}} in 1014 eV<ma<1013 eV10^{-14}~\mathrm{eV} < m_a < 10^{-13}~\mathrm{eV}. Although the bound did not exceed the current best limits, this optical cavity experiment is the first demonstration of polarization-based axion dark matter search without any external magnetic field.Comment: 9 pages, 8 figure

    Differences in response to treatment in children with severe IgA nephropathy according to patient age

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    Aim: To clarify whether the response to treatment of IgA nephropathy (IgAN) differs depending on patient age, we examined the response to treatment according to age of onset in children with IgAN. Methods: We collected data for 44 children with severe IgAN. The children were retrospectively divided into three groups based on their age at disease onset. Group 1 consisted of 24 children under 11 years old, group 2 consisted of 9 children aged 12 to 13 years, and group 3 consisted of 11 children aged over 14 years old. The clinical features and prognosis were analyzed for each group. Results: The urinary protein excretion and serum IgA values in group 3 were higher than those in groups 1 and 2 at the most recent follow up, and histological findings showed that the MESTCG scores in group 3 were higher than those in group 1. Furthermore, the incidence of patients with persistent nephropathy or renal insufficiency in group 3 was higher than those in groups 1 and 2. Conclusions: Patients aged 14 years and older with IgAN may respond poorly to treatment compared with those younger than 14 years old. Therefore, care must be taken regarding response to treatment and relapse when treating older children

    Bortezomib Reduces the Tumorigenicity of Multiple Myeloma via Downregulation of Upregulated Targets in Clonogenic Side Population Cells

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    Side population (SP) cells in cancers, including multiple myeloma, exhibit tumor-initiating characteristics. In the present study, we isolated SP cells from human myeloma cell lines and primary tumors to detect potential therapeutic targets specifically expressed in SP cells. We found that SP cells from myeloma cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11) express CD138 and that non-SP cells include a CD138-negative population. Serial transplantation of SP and non-SP cells into NOD/Shi-scid IL-2 gamma nul mice revealed that clonogenic myeloma SP cells are highly tumorigenic and possess a capacity for self-renewal. Gene expression analysis showed that SP cells from five MM cell lines (RPMI 8226, AMO1, KMS-12-BM, KMS-11, JJN3) express genes involved in the cell cycle and mitosis (e. g., CCNB1, CDC25C, CDC2, BIRC5, CENPE, SKA1, AURKB, KIFs, TOP2A, ASPM), polycomb (e. g., EZH2, EPC1) and ubiquitin-proteasome (e. g., UBE2D3, UBE3C, PSMA5) more strongly than do non-SP cells. Moreover, CCNB1, AURKB, EZH2 and PSMA5 were also upregulated in the SPs from eight primary myeloma samples. On that basis, we used an aurora kinase inhibitor (VX-680) and a proteasome inhibitor (bortezomib) with RPMI 8226 and AMO1 cells to determine whether these agents could be used to selectively target the myeloma SP. We found that both these drugs reduced the SP fraction, though bortezomib did so more effectively than VX-680 due to its ability to reduce levels of both phospho-histone H3 (p-hist. H3) and EZH2; VX-680 reduced only p-hist. H3. This is the first report to show that certain oncogenes are specifically expressed in the myeloma SP, and that bortezomib effectively downregulates expression of their products. Our approach may be useful for screening new agents with which to target a cell population possessing strong tumor initiating potential in multiple myeloma

    Disturbance of cerebellar synaptic maturation in mutant mice lacking BSRPs, a novel brain-specific receptor-like protein family

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    AbstractBy DNA cloning, we have identified the BSRP (brain-specific receptor-like proteins) family of three members in mammalian genomes. BSRPs were predominantly expressed in the soma and dendrites of neurons and localized in the endoplasmic reticulum (ER). Expression levels of BSRPs seemed to fluctuate greatly during postnatal cerebellar maturation. Triple-knockout mice lacking BSRP members exhibited motor discoordination, and Purkinje cells (PCs) were often innervated by multiple climbing fibers with different neuronal origins in the mutant cerebellum. Moreover, the phosphorylation levels of protein kinase Cα (PKCα) were significantly downregulated in the mutant cerebellum. Because cerebellar maturation and plasticity require metabotropic glutamate receptor signaling and resulting PKC activation, BSRPs are likely involved in ER functions supporting PKCα activation in PCs

    Space Demonstration of Two-Layer Pop-Up Origami Deployable Membrane Reflectarray Antenna by 3U CubeSat OrigamiSat-2

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    3U CubeSat OrigamiSat-2 demonstrates a 50-cm × 50-cm two-layer pop-up Origami deployable membrane reflectarray antenna in space. The membrane has small stowage volume and high gain even though it has low flatness because of a large enough antenna area to cover its un-flatness. C-band transmitter is equipped in the CubeSat and offers 20-Mbps amateur satellite communication. In 3U size, a 1-m length deployable gravity gradient mast and magnetic torquer are equipped to stabilize and control its attitude. A camera is attached to the satellite to measure the shape of the membrane antenna. OrigamiSat-2 was selected as the Innovative Satellite Technology Demonstration-4 by Japan Aerospace Exploration Agency (JAXA) and is going to be launched in 2024 by Epsilon Launch Vehicle

    No association between CEL-HYB hybrid allele and chronic pancreatitis in Asian populations

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    International audienceA hybrid allele between the carboxyl ester lipase gene (CEL) and its pseudogene, CELP (called CEL–HYB), generated by non-allelic homologous recombination between CEL intron 10 and CELP intron 10′, was found to increase susceptibility to chronic pancreatitis in a case–control study of patients of European ancestry. We attempted to replicate this finding in 3 independent cohorts from China, Japan, and India, but failed to detect the CEL–HYB allele in any of these populations. The CEL–HYB allele might therefore be an ethnic-specific risk factor for chronic pancreatitis. An alternative hybrid allele (CEL–HYB2) was identified in all 3 Asian populations (1.7% combined carrier frequency), but was not associated with chronic pancreatitis

    TROP2 Expressed in the Trunk of the Ureteric Duct Regulates Branching Morphogenesis during Kidney Development

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    TROP2, a cell surface protein structurally related to EpCAM, is expressed in various carcinomas, though its function remains largely unknown. We examined the expression of TROP2 and EpCAM in fetal mouse tissues, and found distinct patterns in the ureteric bud of the fetal kidney, which forms a tree-like structure. The tip cells in the ureteric bud proliferate to form branches, whereas the trunk cells differentiate to form a polarized ductal structure. EpCAM was expressed throughout the ureteric bud, whereas TROP2 expression was strongest at the trunk but diminished towards the tips, indicating the distinct cell populations in the ureteric bud. The cells highly expressing TROP2 (TROP2high) were negative for Ki67, a proliferating cell marker, and TROP2 and collagen-I were co-localized to the basal membrane of the trunk cells. TROP2high cells isolated from the fetal kidney failed to attach and spread on collagen-coated plates. Using MDCK cells, a well-established model for studying the branching morphogenesis of the ureteric bud, TROP2 was shown to inhibit cell spreading and motility on collagen-coated plates, and also branching in collagen-gel cultures, which mimic the ureteric bud's microenvironment. These results together suggest that TROP2 modulates the interaction between the cells and matrix and regulates the formation of the ureteric duct by suppressing branching from the trunk during kidney development

    Consensus standards for acquisition, measurement, and reporting of intravascular optical coherence tomography studies

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    Objectives: The purpose of this document is to make the output of the International Working Group for Intravascular Optical Coherence Tomography (IWG-IVOCT) Standardization and Validation available to medical and scientific communities, through a peer-reviewed publication, in the interest of improving the diagnosis and treatment of patients with atherosclerosis, including coronary artery disease. Background: Intravascular optical coherence tomography (IVOCT) is a catheter-based modality that acquires images at a resolution of ∼10 μm, enabling visualization of blood vessel wall microstructure in vivo at an unprecedented level of detail. IVOCT devices are now commercially available worldwide, there is an active user base, and the interest in using this technology is growing. Incorporation of IVOCT in research and daily clinical practice can be facilitated by the development of uniform terminology and consensus-based standards on use of the technology, interpretation of the images, and reporting of IVOCT results. Methods: The IWG-IVOCT, comprising more than 260 academic and industry members from Asia, Europe, and the United States, formed in 2008 and convened on the topic of IVOCT standardization through a series of 9 national and international meetings. Results: Knowledge and recommendations from this group on key areas within the IVOCT field were assembled to generate this consensus document, authored by the Writing Committee, composed of academicians who have participated in meetings and/or writing of the text. Conclusions: This document may be broadly used as a standard reference regarding the current state of the IVOCT imaging modality, intended for researchers and clinicians who use IVOCT and analyze IVOCT data
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