14,101 research outputs found

    Atlas Toolkit: Fast registration of 3D morphological datasets in the absence of landmarks

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    Image registration is a gateway technology for Developmental Systems Biology, enabling computational analysis of related datasets within a shared coordinate system. Many registration tools rely on landmarks to ensure that datasets are correctly aligned; yet suitable landmarks are not present in many datasets. Atlas Toolkit is a Fiji/ImageJ plugin collection offering elastic group-wise registration of 3D morphological datasets, guided by segmentation of the interesting morphology. We demonstrate the method by combinatorial mapping of cell signalling events in the developing eyes of chick embryos, and use the integrated datasets to predictively enumerate Gene Regulatory Network states

    Effect of Alisma plantago-aquatica Linn extract on chronic prostatitis in rats

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    Purpose: To study the effect of Alisma plantago-aquatica Linn. extract (APLE) on chronic prostatitis in rats.Methods: Experimental chronic non-bacterial prostatitis (CNP) was induced in rats by injecting carrageenan into prostate. Rats in drug-treated groups were administered APLE or cernilton (positive control, i.e., reference standard) for 3 weeks while rats in normal and negative control groups were treated with saline at the same time. After treatment, prostate index (PI) and prostate-specific antigen (PSA) of all the rats were examined by enzyme-linked immunosorbent assay (ELISA). In addition, the relative inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin 1β (IL-1β), cyclooxygenase-2 (COX-2), prostaglandin E2 (PEG2), transforming growth factor-β1 (TGF-β1) and connective tissue growth factor (CTGF) of the prostate tissues were measured by ELISA.Results: A high dose of APLE (480 mg/kg) significantly decreased PI (0.7 ± 0.2 mg/g) relative to reference group (2.8 ± 0.3 mg/g, p < 0.01), and significantly decreased PSA level (128.6 ± 12.3 pg/mL) relative to reference group (321.3 ± 16.4 pg/mL, p < 0.01). Compared with reference group, TNF-α level (109.7 ± 9.3 pg/mL, p < 0.01), IL-1β level (98.3 ± 12.5 pg/mL, p < 0.01), PEG2 level (81.5 ± 4.2 pg/mL, p < 0.01), COX-2 level (10.5 ± 2.6 pg/mL, p < 0.01), TGF-β1 level (86.8 ± 7.3 pg/mL, p < 0.01) and CTGF level (70.3 ± 4.3 pg/mL, p < 0.01) of prostate tissues of high-dose APLE group rats decreased significantly.Conclusion: APLE shows significant anti-chronic prostatitis activity in rats. Further studies are, however, required to ascertain its therapeutic potentials in humansKeywords: Alisma plantago-aquatica, Chronic prostatitis, Inflammation, Prostate index, Morphometric analysis, Interstitial fibrosi

    Insecticidal Activity of the Leaf and Stem Water Extract of Gelsemium elegans against Solenopsis invicta

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    A comprehensive green worker ants control method that can be used to replace traditional chemical synthetic insecticides. In this study, the leaves and stems of Gelsemium elegans were extracted with water as the solvent, and the bioactivity of G. elegans against worker ants was determined by the “water tube” method. The bioassay results of insecticidal activity showed that when the time was extended to the 10th day, the mortality of worker ants treated with G. elegans extract reached 55.00% (1/20 leaf extract), 46.67% (1/20 stem extract) and 45.00% (1 mg/kg koumine). And the behavioral impact test results showed that the aggregation rate was reduced to 56.67% (1/100 leaf extract), 60.00% (1/100 stem extract) and 60.00% (0.5 mg/kg koumine); the climbing rate was reduced to 60.00 % (1/100 leaf extract), 58.33% (1/100 stem extract) and 58.33% (0.5 mg/kg koumine). The effect on the walking ability of worker ants is obvious. The walking rate drops to 1.53cm/s (1/100 leaf extract), 1.60cm/s (1/100 stem extract) and 1.47cm/s (0.5 mg/kg koumine). Therefore, we conclude that the water extract of G. elegans can be used for long-term continuous control of worker ants, which can be used to replace traditional chemical synthetic insecticides

    Prioritized Sweeping Neural DynaQ with Multiple Predecessors, and Hippocampal Replays

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    During sleep and awake rest, the hippocampus replays sequences of place cells that have been activated during prior experiences. These have been interpreted as a memory consolidation process, but recent results suggest a possible interpretation in terms of reinforcement learning. The Dyna reinforcement learning algorithms use off-line replays to improve learning. Under limited replay budget, a prioritized sweeping approach, which requires a model of the transitions to the predecessors, can be used to improve performance. We investigate whether such algorithms can explain the experimentally observed replays. We propose a neural network version of prioritized sweeping Q-learning, for which we developed a growing multiple expert algorithm, able to cope with multiple predecessors. The resulting architecture is able to improve the learning of simulated agents confronted to a navigation task. We predict that, in animals, learning the world model should occur during rest periods, and that the corresponding replays should be shuffled.Comment: Living Machines 2018 (Paris, France

    A new genus of temperate woody bamboos (Poaceae, Bambusoideae, Arundinarieae) from a limestone montane area of China

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    Ampelocalamus calcareus is a climbing and slender bamboo, known from south Guizhou, China. This species grows in broadleaved forests of limestone montane areas. Recent molecular phylogenetic analyses demonstrated that A. calcareus was sister to all other lineages of the tribe Arundinarieae rather than a member of Ampelocalamus. The morphological features and habitats of A. calcareus and related genera including Ampelocalamus, Drepanostachyum and Himalayacalamus were compared and discussed. The characteristics of the branch complements, nodes and foliage leaves distinguish A. calcareus from morphologically similar taxa. On the basis of molecular and morphological evidence, we propose to establish a new genus, Hsuehochloa, to accommodate A. calcareus and to honour the late Chinese bamboo taxonomist Chi-Ju Hsueh (Ji-Ru Xue). In addition, we describe the inflorescence of Hsuehochloa for the first time

    Charge Measurement of Cosmic Ray Nuclei with the Plastic Scintillator Detector of DAMPE

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    One of the main purposes of the DArk Matter Particle Explorer (DAMPE) is to measure the cosmic ray nuclei up to several tens of TeV or beyond, whose origin and propagation remains a hot topic in astrophysics. The Plastic Scintillator Detector (PSD) on top of DAMPE is designed to measure the charges of cosmic ray nuclei from H to Fe and serves as a veto detector for discriminating gamma-rays from charged particles. We propose in this paper a charge reconstruction procedure to optimize the PSD performance in charge measurement. Essentials of our approach, including track finding, alignment of PSD, light attenuation correction, quenching and equalization correction are described detailedly in this paper after a brief description of the structure and operational principle of the PSD. Our results show that the PSD works very well and almost all the elements in cosmic rays from H to Fe are clearly identified in the charge spectrum.Comment: 20 pages, 4 figure

    Optical Monitoring of BL Lacertae Object OJ 287: a 40-Day Period?

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    We present the results of our optical monitoring of the BL Lacertae object OJ 287 during the first half of 2005. The source did not show large-amplitude variations during this period and was in a relatively quiescent state. A possible period of 40 days was derived from its light curves in three BATC wavebands. A bluer-when-brighter chromatism was discovered, which is different from the extremely stable color during the outburst in 1994--96. The different color behaviors imply different variation mechanisms in the two states. We then re-visited the optical data on OJ 287 from the OJ-94 project and found as well a probable period of 40 days in its optical variability during the late-1994 outburst. The results suggest that two components contribute to the variability of OJ 287 during its outburst state. The first component is the normal {\sl blazar} variation. This component has an amplitude similar to that of the quiescent state and also may share a similar periodicity. The second component can be taken as a `low-frequency modulation' to the first component. It may be induced by the interaction of the assumed binary black holes in the center of this object. The 40-day period may be related to the helical structure of the magnetic field at the base of the jet, or to the orbital motion close to the central primary black hole.Comment: 31 pages, 8 figures, accepted by A

    The impact of a major cluster merger on galaxy evolution in MACS\,J0025.4-1225

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    We present results of an extensive morphological, spectroscopic, and photometric study of the galaxy population of MACS J0025.4-1225 (z=0.586), a major cluster merger with clear segregation of dark and luminous matter, to examine the impact of mergers on galaxy evolution. Based on 436 galaxy spectra obtained with Keck DEIMOS, we identified 212 cluster members within 4 Mpc of the cluster centre, and classified them using three spectroscopic types; we find 111 absorption-line, 90 emission-line (including 23 e(a) and 11 e(b)), and 6 E+A galaxies. The fraction of absorption(emission)-line galaxies is a monotonically increasing(decreasing) function of both projected galaxy density and radial distance to the cluster center. More importantly, the 6 observed E+A cluster members are all located between the dark-matter peaks of the cluster and within ~0.3Mpc radius of the X-ray flux peak, unlike the E+A galaxies in other intermediate-redshift clusters which are usually found to avoid the core region. In addition, we use Hubble Space Telescope imaging to classify cluster members according to morphological type. We find the global fraction of spiral and lenticular galaxies in MACS J0025 to be among the highest observed to date in clusters at z>0.5. The observed E+A galaxies are found to be of lenticular type with Sersic indices of ~2, boosting the local fraction of S0 to 70 per cent between the dark-matter peaks. Combing the results of our analysis of the spatial distribution, morphology, and spectroscopic features of the galaxy population, we propose that the starburst phase of these E+A galaxies was both initiated and terminated during the first core-passage about 0.5--1Gyr ago, and that their morphology has already been transformed into S0 due to ram pressure and/or tidal forces near the cluster core. By contrast, ongoing starbursts are observed predominantly in infalling galaxies, and thus appears to be unrelated to the cluster merger.Comment: 18 pages, 17 figures, accepted by MNRA

    Luminescent properties of Bi-doped polycrystalline KAlCl4

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    We observed an intensive near-infrared luminescence in Bi-doped KAlCl4 polycrystalline material. Luminescence dependence on the excitation wavelength and temperature of the sample was studied. Our experimental results allow asserting that the luminescence peaked near 1 um belongs solely to Bi+ ion which isomorphically substitutes potassium in the crystal. It was also demonstrated that Bi+ luminescence features strongly depend on the local ion surroundings
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