49 research outputs found

    Generating Highly Relevant Questions

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    The neural seq2seq based question generation (QG) is prone to generating generic and undiversified questions that are poorly relevant to the given passage and target answer. In this paper, we propose two methods to address the issue. (1) By a partial copy mechanism, we prioritize words that are morphologically close to words in the input passage when generating questions; (2) By a QA-based reranker, from the n-best list of question candidates, we select questions that are preferred by both the QA and QG model. Experiments and analyses demonstrate that the proposed two methods substantially improve the relevance of generated questions to passages and answers.Comment: Accepted by EMNLP 201

    Roles and regulation of membrane-associated serine proteases

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    Pericellular proteolytic activity affects many aspects of cellular behaviour, via mechanisms involving processing of the extracellular matrix, growth factors and receptors. The serine proteases have exquisitely sensitive regulatory mechanisms in this setting, involving both receptor-bound and transmembrane proteases. Receptor-bound proteases are exemplified by the uPA (urokinase plasminogen activator)/uPAR (uPAR receptor) plasminogen activation system. The mechanisms initiating the activity of this proteolytic system on the cell surface, a critical regulatory point, are poorly understood. We have found that the expression of the TTSP (type II transmembrane serine protease) matriptase is highly regulated in leucocytes, and correlates with the presence of active uPA on their surface. Using siRNA (small interfering RNA), we have demonstrated that matriptase specifically activates uPAR-associated pro-uPA. The uPA/uPAR system has been implicated in the activation of the plasminogen-related growth factor HGF (hepatocyte growth factor). However, we find no evidence for this, but instead that HGF can be activated by both matriptase and the related TTSP hepsin in purified systems. Hepsin is of particular interest, as the proteolytic cleavage sequence of HGF is an ‘ideal substrate’ for hepsin and membrane-associated hepsin activates HGF with high efficiency. Both of these TTSPs can be activated autocatalytically at the cell surface, an unusual mechanism among the serine proteases. Therefore these TTSPs have the capacity to be true upstream initiators of proteolytic activity with subsequent downstream effects on cell behaviour

    Pericellular activation of hepatocyte growth factor by the transmembrane serine proteases matriptase and hepsin, but not by the membrane-associated protease uPA

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    HGF (hepatocyte growth factor) is a pleiotropic cytokine homologous to the serine protease zymogen plasminogen that requires canonical proteolytic cleavage to gain functional activity. The activating proteases are key components of its regulation, but controversy surrounds their identity. Using quantitative analysis we found no evidence for activation by uPA (urokinase plasminogen activator), despite reports that this is a principal activator of pro-HGF. This was unaffected by a wide range of experimental conditions, including the use of various molecular forms of both HGF and uPA, and the presence of uPAR (uPA receptor) or heparin. In contrast the catalytic domains of the TTSPs (type-II transmembrane serine proteases) matriptase and hepsin were highly efficient activators (50% activation at 0.1 and 3.4 nM respectively), at least four orders of magnitude more efficient than uPA. PS-SCL (positional-scanning synthetic combinatorial peptide libraries) were used to identify consensus sequences for the TTSPs, which in the case of hepsin corresponded to the pro-HGF activation sequence, demonstrating a high specificity for this reaction. Both TTSPs were also found to be efficient activators at the cell surface. Activation of pro-HGF by PC3 prostate carcinoma cells was abolished by both protease inhibition and matriptase-targeting siRNA (small interfering RNA), and scattering of MDCK (Madin–Darby canine kidney) cells in the presence of pro-HGF was abolished by inhibition of matriptase. Hepsin-transfected HEK (human embryonic kidney)-293 cells also activated pro-HGF. These observations demonstrate that, in contrast with the uPA/uPAR system, the TTSPs matriptase and hepsin are direct pericellular activators of pro-HGF, and that together these proteins may form a pathway contributing to their involvement in pathological situations, including cancer

    Study of the Sacharomyces cerevisiae ribosomal stalk interactions with other ribosomal components using chemical cross-linking

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    Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 13-12-200

    SIMULATION AND ANALYSIS ON THERMAL CHARACTERISTIC OF SPINDLE REDUCER BOX OF BORING AND MILLING MACHINING CENTER

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    The 3D model of spindle reducer box of Boring and Milling Machining Center was established. The gear transmission was analyzed. The thermal load was found by calculating the heat flow of the gear and the heat generated of bearing.The calculated heat convection coefficient was defined as the boundary condition. The temperature field of the spindle reducer box was simulated. By thermal-structure coupling analysis,the thermal deformation results of the box and gears were obtained.Finally,the reliability of spindle box was verified according to the comparison of the simulation result against the nominal clearance

    Combining a COI Mini-Barcode with Next-Generation Sequencing for Animal Origin Ingredients Identification in Processed Meat Product

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    For revealing animal species in complex or adulterated processed meat product, we presented a method combining a novel cytochrome oxidase I (COI) mini-barcode with next-generation sequencing (NGS), which identifies various animal species (swine, bovine, Caprinae, and some of fish, shrimp, and poultry) accurately and efficiently in processed meat products. We designed a universal primer based on 140 sequences from 51 edible animal species. A mixture of 12 species raw meat samples were identified with the clone sequencing and also with a mini-barcode- (136 bp) combined NGS method, respectively. The mini-barcode of these 12 species was 100% identical to the target species sequence by Sanger sequencing. Compared to the clone sequencing method, the NGS method is superior in accuracy, sensitivity, and detection efficiency. Various edible animal species were identified in the species level both in the mixed samples and the 7 heavily processed food products. Moreover, some unlabeled species and dubious contamination were detected as well

    Two new species of Episymploce Bey-Bienko, 1950 (Blattodea, Ectobiidae, Blattellinae) from China

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    Two new species of Episymploce Bey-Bienko from China are described. Nine individuals of E. sichuanensis sp. nov. were collected from Sichuan Province and four individuals of E. maxima, sp. nov. were collected from Guangxi Province. Morphology, especially the wings, specialized abdominal tergum and genitalia of adults, are described and illustrated in detail. Episymploce sichuanensis sp. nov. is similar to E. kunmingi (Bey-Bienko, 1969), but can be easily distinguished by the reduced wings, bifurcated two processes at the hind margin of the supra-anal plate, and the unspecialized first abdominal tergum (T1). Episymploce maxima sp. nov. is similar to E. taiheizana Asahina, 1979 but is distinguished by its large size, the lateromedial margins of the subgenital plate without processes, and the unspecialized T1. A key to the recorded Episymploce species from China is provided in this paper

    One new species in the cockroach genus Jacobsonina Hebard 1929 (Blattodea, Ectobiidae, Blattellinae) from Mainland China

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    Wu, Keliang, Yue, Qiaoyun, Qiu, Deyi, Liu, Dexing (2014): One new species in the cockroach genus Jacobsonina Hebard 1929 (Blattodea, Ectobiidae, Blattellinae) from Mainland China. Zootaxa 3847 (2): 275-282, DOI: http://dx.doi.org/10.11646/zootaxa.3847.2.

    The Ectopic Expression of CaRop1 Modulates the Response of Tobacco Plants to Ralstonia solanacearum and Aphids

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    In plants, Rho-related GTPases (Rops) are versatile molecular switches that regulate various biological processes, although their exact roles are not fully understood. Herein, we provide evidence that the ectopic expression of a Rop derived from Capsicum annuum, designated CaRop1, in tobacco plants modulates the response of these plants to Ralstonia solanacearum or aphid attack. The deduced amino acid sequence of CaRop1 harbors a conserved Rho domain and is highly homologous to Rops of other plant species. Transient expression of a CaRop1-GFP fusion protein in Nicotiana benthamiana leaf epidermal cells revealed localization of the GFP signal to the plasma membrane, cytoplasm, and nucleus. Overexpression (OE) of the wild-type CaRop1 or its dominant-negative mutant (DN-CaRop1) conferred substantial resistance to R. solanacearum infection and aphid attack, and this effect was accompanied by enhanced transcriptional expression of the hypersensitive-reaction marker gene HSR201; the jasmonic-acid (JA)-responsive PR1b and LOX1; the insect resistance-associated NtPI-I, NtPI-II, and NtTPI; the ethylene (ET) production-associated NtACS1; and NPK1, a mitogen-activated protein kinase kinase kinase (MAPKKK) that interferes with N-, Bs2-, and Rx-mediated disease resistance. In contrast, OE of the constitutively active mutant of CaRop1(CA-CaRop1) enhanced susceptibility of the transgenic tobacco plants to R. solanacearum infection and aphid attack and downregulated or sustained the expression of HSR201, PR1b, NPK1, NtACS1, NtPI-I, NtPI-II and NtTPI. These results collectively suggest that CaRop1 acts as a signaling switch in the crosstalk between Solanaceaes’s response to R. solanacearum infection and aphid attack possibly via JA/ET-mediated signaling machinery

    Functional analysis and expressional characterization of rice ankyrin repeat-containing protein, OsPIANK1, in basal defense against Magnaporthe oryzae attack.

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    The ankyrin repeat-containing protein gene OsPIANK1 (AK068021) in rice (Oryza sativa L.) was previously shown to be upregulated following infection with the rice leaf blight pathogen Xanthomonas oryzae pv oryzae (Xoo). In this study, we further characterized the role of OsPIANK1 in basal defense against Magnaporthe oryzae (M.oryzae) by 5' deletion analysis of its promoter and overexpression of the gene. The promoter of OsPIANK1 with 1,985 bps in length was sufficient to induce the OsPIANK1 response to inoculation with M.oryzae and to exogenous application of methyl jasmonate (MeJA) or salicylic acid (SA), but not to exogenous application of abscisic acid (ABA). A TCA-element present in the region between -563 bp and -249 bp may be responsible for the OsPIANK1 response to both M.oryzae infection and exogenous SA application. The JERE box, CGTCA-box, and two MYB binding sites locating in the region between -1985 bp and -907 bp may be responsible for the response of OsPIANK1 to exogenous MeJA. OsPIANK1 expression was upregulated after inoculation with M.oryzae and after treatment with exogenous SA and MeJA. Overexpression of OsPIANK1 enhanced resistance of rice to M.oryzae, although it did not confer complete resistance. The enhanced resistance to M.oryzae was accompanied by enhanced transcriptional expression of SA- and JA-dependent genes such as NH1, WKRY13, PAL, AOS2, PR1b, and PR5. This evidence suggests that OsPIANK1 acted as a positive regulator in rice basal defense mediated by SA- and JA-signaling pathways
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