3,411 research outputs found

    Learning to Place New Objects

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    The ability to place objects in the environment is an important skill for a personal robot. An object should not only be placed stably, but should also be placed in its preferred location/orientation. For instance, a plate is preferred to be inserted vertically into the slot of a dish-rack as compared to be placed horizontally in it. Unstructured environments such as homes have a large variety of object types as well as of placing areas. Therefore our algorithms should be able to handle placing new object types and new placing areas. These reasons make placing a challenging manipulation task. In this work, we propose a supervised learning algorithm for finding good placements given the point-clouds of the object and the placing area. It learns to combine the features that capture support, stability and preferred placements using a shared sparsity structure in the parameters. Even when neither the object nor the placing area is seen previously in the training set, our algorithm predicts good placements. In extensive experiments, our method enables the robot to stably place several new objects in several new placing areas with 98% success-rate; and it placed the objects in their preferred placements in 92% of the cases

    Doubly Heavy Baryon Production at A High Luminosity e+ee^+ e^- Collider

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    Within the framework of nonrelativistic QCD, we make a detailed discussion on the doubly heavy baryon production through the e+ee^+ e^- annihilation channel, e+eγ/Z0ΞQQ+Qˉ+Qˉe^{+}e^{-}\rightarrow\gamma/Z^0 \rightarrow \Xi_{QQ^{\prime}} +\bar{Q} +\bar{Q^{\prime}}, at a high luminosity e+ee^{+}e^{-} collider. Here Q()Q^{(\prime)} stands for the heavy bb or cc quark. In addition to the channel through the usually considered diquark state (QQ)[3S1]3ˉ(QQ^{\prime})[^3S_1]_{\bf\bar{3}}, contributions from the channels through other same important diquark states such as (QQ)[1S0]6(QQ^{\prime})[^1S_0]_{\bf 6} have also been discussed. Uncertainties for the total cross sections are predicted by taking mc=1.80±0.30m_c=1.80\pm0.30 GeV and mb=5.10±0.40m_b=5.10\pm0.40 GeV. At a super ZZ-factory running around the Z0Z^0 mass and with a high luminosity up to L10341036cm2s1{\cal L} \propto 10^{34}\sim 10^{36}{\rm cm}^{-2} {\rm s}^{-1}, we estimate that about 1.1×10571.1\times10^{5 \sim 7} Ξcc\Xi_{cc} events, 2.6×10572.6\times10^{5 \sim 7} Ξbc\Xi_{bc} events and 1.2×10461.2\times 10^{4 \sim 6} Ξbb\Xi_{bb} events can be generated in one operation year. Such a ZZ-factory, thus, will provide a good platform for studying the doubly heavy baryons in comparable to the CERN large hadronic collider.Comment: 9 pages, 4 figures. To be published in Phys.Rev.

    Oxidative stress in a rat model of cotton smoke inhalation-induced pulmonary injury

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    Background: Smoke inhalation injury refers to airway and lung parenchyma injury and general chemical damage caused by inhaling toxic gases and substances. The aim of this study was to explore the oxidative stress mechanism of cotton smoke inhalation-induced pulmonary injury in a rat model.Materials and Methods: Eighteen male Sprague-Dawley rats were randomly divided into control group, 6 h group, and 24 h group (six rats in each group), which duplicated previous rat cotton smoke-inhalation injury models. Rats in 6 h and 24 h groups were euthanised at 6 h and 24 h after smoke inhalation, respectively. ELISA method was used to detect indicators in the rats’ lung tissue. Quantitative iNOS mRNA and γ-GCS mRNA measurements were performed using a fluorescence PCR method.Results: The concentrations of MDA, NO, iNOS, γ-GCS, iNOS mRNA, and the relative expression of γ-GCS mRNA in the rats’ lung tissues in 6 h and 24 h groups were higher than control group (P < 0.05), and the concentration of NO and relative expressions of iNOS mRNA and γ-GCS mRNA in 24 h group were significantly higher than 6 h group (P < 0.05). The concentrations of GSH in 24 h and 6 h groups were significantly lower than control group (P < 0.05), and that in 24 h group was even significantly lower than 6 h group (P < 0.05).Conclusion: In rats with cotton smoke inhalation-induced pulmonary injury, the increased iNOS mRNA transcription can cause increase of iNOS synthesis and promotion of NO synthesis. The increased γ-GCS mRNA transcription can cause increase of γ-GCS synthesis and but decrease of GSH concentration. The activation of the antioxidant system is insufficient to combat oxidative stress damage. So the oxidant/antioxidant system is imbalanced, leading to gradual aggravation of lung injury.Keywords: Acute lung injury, Smoke inhalation injury, Oxidative stres

    Effect of prodigiosin on the alleviation of the intestinal inflammation of weaned rats based on 1H-NMR spectroscopy study and biochemistry indexes

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    Weaning results in intestinal dysfunction, mucosal atrophy, transient anorexia, and intestinal barrier defects. In this study, the effect of prodigiosin (PG) on the intestinal inflammation of weaned rats was investigated by using 1 H-NMR spectroscopy and biochemistry indexes to regulate the intestinal metabolism. After administration for 14 days, the body mass of the PG group was increased by 1.29‑ and 1.26-fold compared with those of the control and alcohol groups, respectively, using a dose of 200 μg PG·kg-1 body weight per day. PG increased organic acid content and decreased moisture, pH values, and free ammonia in feces. In addition, PG alleviated the intestinal inflammation of weaned rats. The analysis of 1 H-NMR signal peak attribution and the model validation of metabolic data of feces contents showed that PG significantly affected the metabolism of small molecular compounds in the intestinal tract of weaned rats. This study presents the promising alternative of using PG to alleviate intestinal inflammation effectively in the intestinal tract of weaned rats

    Deep sequencing of small RNA libraries reveals dynamic regulation of conserved and novel microRNAs and microRNA-stars during silkworm development

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    <p>Abstract</p> <p>Background</p> <p>In eukaryotes, microRNAs (miRNAs) have emerged as critical regulators of gene expression. The Silkworm (<it>Bombyx mori </it>L.) is one of the most suitable lepidopteran insects for studying the molecular aspects of metamorphosis because of its large size, availability of mutants and genome sequence. Besides, this insect also has been amply studied from a physiological and biochemical perspective. Deep sequencing of small RNAs isolated from different stages of silkworm is a powerful tool not only for measuring the changes in miRNA profile but also for discovering novel miRNAs.</p> <p>Results</p> <p>We generated small RNA libraries from feeding larvae, spinning larvae, pupae and adults of <it>B. mori </it>and obtained ~2.5 million reads of 18-30 nt. Sequence analysis identified 14 novel and 101 conserved miRNAs. Most novel miRNAs are preferentially expressed in pupae, whereas more than 95% of the conserved miRNAs are dynamically regulated during different developmental stages. Remarkably, the miRNA-star (miR*) of four miRNAs are expressed at much higher levels than their corresponding miRNAs, and their expression profiles are distinct from their corresponding miRNA profiles during different developmental stages. Additionally, we detected two antisense miRNA loci (miR-263-S and miR-263-AS; miR-306-S and miR-306-AS) that are expressed in sense and antisense directions. Interestingly, miR-263 and miR-306 are preferentially and abundantly expressed in pupae and adults, respectively.</p> <p>Conclusions</p> <p>We identified 101 homologs of conserved miRNAs, 14 species-specific and two antisense miRNAs in the silkworm. Our results provided deeper insights into changes in conserved and novel miRNA and miRNA* accumulation during development.</p
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