359 research outputs found

    Grassland Monitoring System for Sustainable Utilisation in Inner Mongolia, China. 2. Real-Time Monitoring of Grass and Animal Interaction Using Satellite Data and GPS

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    Overgrazing is one of the primary causes of desertification in Inner Mongolia grassland. A previous paper estimated herbage quantity and quality (Kawamura et al., 2005), and quantified the grazing intensity on grass biomass using Terra MODIS satellite, Global Positioning Systems (GPS) and GIS (Kawamura et al., 2003). The aim of this study is real-time monitoring of both grass biomass and animal behaviour to evaluate the effect of grazing intensity (GI) on grass growth rate during the growing season using Terra MODIS satellite and GPS

    Probing Non-Standard Neutrino Interactions with Neutrino Factories

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    We discuss the sensitivity reach of a neutrino factory measurement to non-standard neutrino interactions (NSI), which may exist as a low-energy manifestation of physics beyond the Standard Model. We use the muon appearance mode \nu_e --> \nu_\mu and consider two detectors, one at 3000 km and the other at 7000 km. Assuming the effects of NSI at the production and the detection are negligible, we discuss the sensitivities to NSI and the simultaneous determination of \theta_{13} and \delta by examining the effects in the neutrino propagation of various systems in which two NSI parameters \epsilon_{\alpha \beta} are switched on. The sensitivities to off-diagonal \epsilon's are found to be excellent up to small values of \theta_{13}. We demonstrate that the two-detector setting is powerful enough to resolve the \theta_{13}-NSI confusion problem. We believe that the results obtained in this paper open the door to the possibility of using neutrino factory as a discovery machine for NSI while keeping its primary function of performing precision measurements of the lepton mixing parameters.Comment: 47 pages, 22 figures. Color version of Figs. 18, 19 and 22 can be found in the article published in JHE

    Neurocytotoxic effects of iron-ions on the developing brain measured in vivo using medaka (Oryzias latipes), a vertebrate model

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    Purpose: Exposure to heavy-ion radiation is considered a critical health risk on long-term space missions. The developing central nervous system (CNS) is a highly radiosensitive tissue; however, the biological effects of heavy-ion radiation, which are greater than those of low-linear energy transfer (LET) radiation, are not well studied, especially in vivo in intact organisms. Here, we examined the effects of iron-ions on the developing CNS using vertebrate organism, fish embryos of medaka (Oryzias latipes)

    Neutral currents and tests of three-neutrino unitarity in long-baseline experiments

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    We examine a strategy for using neutral current measurements in long-baseline neutrino oscillation experiments to put limits on the existence of more than three light, active neutrinos. We determine the relative contributions of statistics, cross section uncertainties, event misidentification and other systematic errors to the overall uncertainty of these measurements. As specific case studies, we make simulations of beams and detectors that are like the K2K, T2K, and MINOS experiments. We find that the neutral current cross section uncertainty and contamination of the neutral current signal by charge current events allow a sensitivity for determining the presence of sterile neutinos at the 0.10--0.15 level in probablility.Comment: 24 pages, Latex2e, uses graphicx.sty, 2 postscript figures. Submitted to the Neutrino Focus Issue of New Journal Physics at http://www.njp.or

    Design and testing of hydrophobic core/hydrophilic shell nano/micro particles for drug-eluting stent coating

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    In this study, we designed a novel drug-eluting coating for vascular implants consisting of a core coating of the anti-proliferative drug docetaxel (DTX) and a shell coating of the platelet glycoprotein IIb/IIIa receptor monoclonal antibody SZ-21. The core/shell structure was sprayed onto the surface of 316L stainless steel stents using a coaxial electrospray process with the aim of creating a coating that exhibited a differential release of the two drugs. The prepared stents displayed a uniform coating consisting of nano/micro particles. In vitro drug release experiments were performed, and we demonstrated that a biphasic mathematical model was capable of capturing the data, indicating that the release of the two drugs conformed to a diffusion-controlled release system. We demonstrated that our coating was capable of inhibiting the adhesion and activation of platelets, as well as the proliferation and migration of smooth muscle cells (SMCs), indicating its good biocompatibility and anti-proliferation qualities. In an in vivo porcine coronary artery model, the SZ-21/DTX drug-loaded hydrophobic core/hydrophilic shell particle coating stents were observed to promote re-endothelialization and inhibit neointimal hyperplasia. This core/shell particle-coated stent may serve as part of a new strategy for the differential release of different functional drugs to sequentially target thrombosis and in-stent restenosis during the vascular repair process and ensure rapid re-endothelialization in the field of cardiovascular disease

    Radiopurity of NaI(Tl) crystals for PICOLON dark matter experiment

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    The dark matter observation claim by the DAMA/LIBRA collaboration has been a long-standing puzzle within the particle physics community. Efforts of other research groups to verify the claim have been insufficient by significant radioactivity of present NaI(Tl) crystals. PICOLON (Pure Inorganic Crystal Observatory for LOw-energy Neut(ra)lino) experiment conducts independent search for Weakly Interacting Massive Particles (WIMPs) using NaI(Tl) crystals. Our NaI(Tl) crystal manufactured in 2020 (Ingot #85) reached the same purity level as DAMA/LIBRA crystals. In this report, we describe the radiopurity of the new Ingot #94 crystal produced using the same purification technique as Ingot #85. The α\alpha-ray events were selected by pulse-shape discrimination method. The impurities in the Ingot #94, 232^{232}Th, 226^{226}Ra and 210^{210}Po radioactivity were 4.6±1.2 μBq/kg4.6\pm 1.2~\mathrm{\mu Bq/kg}, 7.9±4.4 μBq/kg7.9\pm 4.4~\mathrm{\mu Bq/kg}, and 19±6 μBq/kg19\pm 6~\mathrm{\mu Bq/kg}, which are equivalent to those of the DAMA/LIBRA crystals. The background rate in the energy region of 2-6 keV , was 2-5 events/d/kg/keV without applying a veto trigger.Comment: 14pages, 16 figure

    Development of highly radiopure NaI(Tl) scintillator for PICOLON dark matter search project

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    Highly radiopure NaI(Tl) was developed to search for particle candidates of dark matter. Optimized methods were combined to reduce various radioactive impurities. 40K was effectively reduced by the recrystallization method. The progenies of the decay chains of uranium and thorium were reduced by appropriate resins. The concentration of natural potassium in NaI(Tl) crystal was reduced to 20 ppb. Concentrations of alpha-ray emitters were successfully reduced by appropriate resin selection. The present concentrations of the thorium series and 226Ra were 1.2±1.4μBq/kg and 13±4μBq/kg, respectively. No significant excess in the concentration of 210Pb was obtained, and the upper limit was 5.7 μBq/kg at 90% CL. The achieved level of radiopurity of NaI(Tl) crystals makes the construction of a dark matter detector possible

    The Hyper Suprime-Cam SSP Survey: Overview and Survey Design

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    Hyper Suprime-Cam (HSC) is a wide-field imaging camera on the prime focus of the 8.2m Subaru telescope on the summit of Maunakea in Hawaii. A team of scientists from Japan, Taiwan and Princeton University is using HSC to carry out a 300-night multi-band imaging survey of the high-latitude sky. The survey includes three layers: the Wide layer will cover 1400 deg2^2 in five broad bands (grizygrizy), with a 5σ5\,\sigma point-source depth of r26r \approx 26. The Deep layer covers a total of 26~deg2^2 in four fields, going roughly a magnitude fainter, while the UltraDeep layer goes almost a magnitude fainter still in two pointings of HSC (a total of 3.5 deg2^2). Here we describe the instrument, the science goals of the survey, and the survey strategy and data processing. This paper serves as an introduction to a special issue of the Publications of the Astronomical Society of Japan, which includes a large number of technical and scientific papers describing results from the early phases of this survey.Comment: 14 pages, 7 figures, 5 tables. Corrected for a typo in the coordinates of HSC-Wide spring equatorial field in Table

    PICOLON dark matter search project

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    PICOLON (Pure Inorganic Crystal Observatory for LOw-energy Neutr(al)ino) aims to search for cosmic dark matter by high purity NaI(Tl) scintillator. We developed extremely pure NaI(Tl) crystal by hybrid purification method. The recent result of 210Pb in our NaI(Tl) is less than 5.7 μBq/kg. We will report the test experiment in the low-background measurement at Kamioka Underground Laboratory. The sensitivity for annual modulating signals and finding dark matter particles will be discussed

    Mitochondrial Localization of ABC Transporter ABCG2 and Its Function in 5-Aminolevulinic Acid-Mediated Protoporphyrin IX Accumulation

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    Accumulation of protoporphyrin IX (PpIX) in malignant cells is the basis of 5-aminolevulinic acid (ALA)-mediated photodynamic therapy. We studied the expression of proteins that possibly affect ALA-mediated PpIX accumulation, namely oligopeptide transporter-1 and -2, ferrochelatase and ATP-binding cassette transporter G2 (ABCG2), in several tumor cell lines. Among these proteins, only ABCG2 correlated negatively with ALA-mediated PpIX accumulation. Both a subcellular fractionation study and confocal laser microscopic analysis revealed that ABCG2 was distributed not only in the plasma membrane but also intracellular organelles, including mitochondria. In addition, mitochondrial ABCG2 regulated the content of ALA-mediated PpIX in mitochondria, and Ko143, a specific inhibitor of ABCG2, enhanced mitochondrial PpIX accumulation. To clarify the possible roles of mitochondrial ABCG2, we characterized stably transfected-HEK (ST-HEK) cells overexpressing ABCG2. In these ST-HEK cells, functionally active ABCG2 was detected in mitochondria, and treatment with Ko143 increased ALA-mediated mitochondrial PpIX accumulation. Moreover, the mitochondria isolated from ST-HEK cells exported doxorubicin probably through ABCG2, because the export of doxorubicin was inhibited by Ko143. The susceptibility of ABCG2 distributed in mitochondria to proteinase K, endoglycosidase H and peptide-N-glycosidase F suggested that ABCG2 in mitochondrial fraction is modified by N-glycans and trafficked through the endoplasmic reticulum and Golgi apparatus and finally localizes within the mitochondria. Thus, it was found that ABCG2 distributed in mitochondria is a functional transporter and that the mitochondrial ABCG2 regulates ALA-mediated PpIX level through PpIX export from mitochondria to the cytosol
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