3,515 research outputs found

    An enhanced convolutional neural network model for answer selection

    Full text link
    © 2017 International World Wide Web Conference Committee (IW3C2), published under Creative Commons CC BY 4.0 License. Answer selection is an important task in question answering (QA) from the Web. To address the intrinsic difficulty in encoding sentences with semantic meanings, we introduce a general framework, i.e., Lexical Semantic Feature based Skip Convolution Neural Network (LSF-SCNN), with several optimization strategies. The intuitive idea is that the granular representations with more semantic features of sentences are deliberately designed and estimated to capture the similarity between question-answer pairwise sentences. The experimental results demonstrate the effectiveness of the proposed strategies and our model outperforms the state-of-the-art ones by up to 3.5% on the metrics of MAP and MRR

    Recent changes of water discharge and sediment load in the Yellow River basin, China

    Get PDF
    The Yellow River basin contributes approximately 6% of the sediment load from all river systems globally, and the annual runoff directly supports 12% of the Chinese population. As a result, describing and understanding recent variations of water discharge and sediment load under global change scenarios are of considerable importance. The present study considers the annual hydrologic series of the water discharge and sediment load of the Yellow River basin obtained from 15 gauging stations (10 mainstream, 5 tributaries). The Mann-Kendall test method was adopted to detect both gradual and abrupt change of hydrological series since the 1950s. With the exception of the area draining to the Upper Tangnaihai station, results indicate that both water discharge and sediment load have decreased significantly (p<0.05). The declining trend is greater with distance downstream, and drainage area has a significant positive effect on the rate of decline. It is suggested that the abrupt change of the water discharge from the late 1980s to the early 1990s arose from human extraction, and that the abrupt change in sediment load was linked to disturbance from reservoir construction.Geography, PhysicalGeosciences, MultidisciplinarySCI(E)43ARTICLE4541-5613

    Behavioural stress responses predict environmental perception in European sea bass (Dicentrarchus labrax)

    Get PDF
    Individual variation in the response to environmental challenges depends partly on innate reaction norms, partly on experience-based cognitive/emotional evaluations that individuals make of the situation. The goal of this study was to investigate whether pre-existing differences in behaviour predict the outcome of such assessment of environmental cues, using a conditioned place preference/avoidance (CPP/CPA) paradigm. A comparative vertebrate model (European sea bass, Dicentrarchus labrax) was used, and ninety juvenile individuals were initially screened for behavioural reactivity using a net restraining test. Thereafter each individual was tested in a choice tank using net chasing as aversive stimulus or exposure to familiar conspecifics as appetitive stimulus in the preferred or non preferred side respectively (called hereafter stimulation side). Locomotor behaviour (i.e. time spent, distance travelled and swimming speed in each tank side) of each individual was recorded and analysed with video software. The results showed that fish which were previously exposed to appetitive stimulus increased significantly the time spent on the stimulation side, while aversive stimulus led to a strong decrease in time spent on the stimulation side. Moreover, this study showed clearly that proactive fish were characterised by a stronger preference for the social stimulus and when placed in a putative aversive environment showed a lower physiological stress responses than reactive fish. In conclusion, this study showed for the first time in sea bass, that the CPP/CPA paradigm can be used to assess the valence (positive vs. negative) that fish attribute to different stimuli and that individual behavioural traits is predictive of how stimuli are perceived and thus of the magnitude of preference or avoidance behaviour.European Commission [265957]; Portuguese Fundacao para a Ciencia e Tecnologia (FCT) [FRH/BPD/72952/2010]; FCT [SFRH/BD/80029/2011

    Development of a LAMP assay for detection of Leishmania infantum infection in dogs using conjunctival swab samples

    Get PDF
    Background: Leishmania infantum infections in dogs play a crucial role in the transmission of pathogens causing visceral leishmaniasis to humans in the Gansu province, northwest China. To be able to control zoonotic transmission of the parasite to humans, a non-invasive loop-mediated isothermal amplification (LAMP) assay to specifically detect L. infantum infections in dogs was developed. Methods: The primers used in the LAMP assay were designed to target kinetoplast DNA minicircle sequences of the L. infantum isolate MCAN/CN/90/SC and tested using DNA isolated from promastigotes of different Leishmania species. The LAMP assay was evaluated with conjunctional swab samples obtained from 111 and 33 dogs living in an endemic and a non-endemic region of zoonotic visceral leishmaniasis in the Gansu province, respectively. The LAMP assay was also compared with conventional PCR, ELISA and microscopy using conjunctional swab, serum and bone marrow samples from the dogs, respectively. Results: The LAMP assay detected 1 fg of L. infantum DNA purified from cultured promastigotes which was 10-fold more sensitive than a conventional PCR test using Leishmania genus-specific primers. No cross reaction was observed with DNA isolated from promastigotes of L. donovani, L. major, L. tropica, and L. braziliensis, and the L. infantum reference strain MHOM/TN/80/IPT1. The L. infantum-positive rates obtained for field-collected samples were 61.3%, 58.6%, 40.5% and 10.8% by LAMP, PCR, ELISA and microscopy, respectively. As only one out of the 33 samples from control dogs from the non-endemic region of zoonotic visceral leishmaniasis was positive by the LAMP assay and the PCR test, the observed true negative rate (specificity) was 97% for both methods. Conclusion: This study has shown that the non-invasive, conjunctional swab-based LAMP assay developed was more sensitive in the detection of leishmaniasis in dogs than PCR, ELISA and microscopy. The findings indicate that the LAMP assay is a sensitive and specific method for the field surveillance of domestic dogs, particularly of asymptomatic canines, in ZVL-endemic areas in western China

    CD69 is a TGF-β/1α,25-dihydroxyvitamin D3 target gene in monocytes

    Get PDF
    CD69 is a transmembrane lectin that can be expressed on most hematopoietic cells. In monocytes, it has been functionally linked to the 5-lipoxygenase pathway in which the leukotrienes, a class of highly potent inflammatory mediators, are produced. However, regarding CD69 gene expression and its regulatory mechanisms in monocytes, only scarce data are available. Here, we report that CD69 mRNA expression, analogous to that of 5-lipoxygenase, is induced by the physiologic stimuli transforming growth factor-β (TGF-β) and 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3) in monocytic cells. Comparison with T- and B-cell lines showed that the effect was specific for monocytes. CD69 expression levels were increased in a concentration-dependent manner, and kinetic analysis revealed a rapid onset of mRNA expression, indicating that CD69 is a primary TGF-β/1α,25(OH)2D3 target gene. PCR analysis of different regions of the CD69 mRNA revealed that de novo transcription was initiated and proximal and distal parts were induced concomitantly. In common with 5-lipoxygenase, no activation of 0.7 kb or ~2.3 kb promoter fragments by TGF-β and 1α,25(OH)2D3 could be observed in transient reporter assays for CD69. Analysis of mRNA stability using a transcription inhibitor and a 3′UTR reporter construct showed that TGF-β and 1α,25(OH)2D3 do not influence CD69 mRNA stability. Functional knockdown of Smad3 clearly demonstrated that upregulation of CD69 mRNA, in contrast to 5-LO, depends on Smad3. Comparative studies with different inhibitors for mitogen activated protein kinases (MAPKs) revealed that MAPK signalling is involved in CD69 gene regulation, whereas 5-lipoxygenase gene expression was only partly affected. Mechanistically, we found evidence that CD69 gene upregulation depends on TAK1-mediated p38 activation. In summary, our data indicate that CD69 gene expression, conforming with 5-lipoxygenase, is regulated monocyte-specifically by the physiologic stimuli TGF-β and 1α,25(OH)2D3 on mRNA level, although different mechanisms account for the upregulation of each gene

    Study of mass and momentum transfer in diesel sprays base on X-ray mass distribution measurements and on a theoretical derivation

    Full text link
    [EN] In this paper, a research aimed at quantifying mass and momentum transfer in the near-nozzle field of diesel sprays injected into stagnant ambient air is reported. The study combines X-ray measurements for two different nozzles and axial positions, which provide mass distributions in the spray, with a theoretical model based on momentum flux conservation, which was previously validated. This investigation has allowed the validation of Gaussian profiles for local fuel concentration and velocity near the nozzle exit, as well as the determination of Schmidt number at realistic diesel spray conditions. This information could be very useful for those who are interested in spray modeling, especially at high-pressure injection conditions. © 2010 Springer-Verlag.This work was partly sponsored by "Vicerrectorado de Investigacion, Desarrollo e Innovacion'' of the "Universidad Politecnica de Valencia'' in the frame of the project "Estudio del flujo en el interior de toberas de inyeccion Diesel'', reference no. 3150 and by "Generalitat Valenciana'' in the frame of the project with the same title and reference GV/2009/031. This support is gratefully acknowledged by the authors.Desantes, J.; Salvador Rubio, FJ.; López, JJ.; De La Morena, J. (2011). Study of mass and momentum transfer in diesel sprays base on X-ray mass distribution measurements and on a theoretical derivation. Experiments in Fluids. 50(2):233-246. https://doi.org/10.1007/s00348-010-0919-8S233246502Abramovich GN (1963) The theory of turbulent jets. MIT Press, Cambridge, MAAdler D, Lyn WT (1969) The evaporation and mixing of a liquid fuel spray in a Diesel air swirl. Proc Instn Mech Eng 184:171–180Coghe A, Cossali GE (1994) Phase Doppler characterisation of a Diesel spray injected into a high density gas under vaporisation regimes. In: 7th international symposium on application of laser techniques to fluid mechanics, LisbonCorreas D (1998) Theoretical and experimental study of isothermal Diesel free sprays (in Spanish). PhD Thesis, Universidad Politécnica de ValenciaCossali GE (2001) An integral model for gas entrainment into full cone sprays. J Fluid Mech 439:353–366Dent JC (1971) A basis for the comparison of various experimental methods for studying spray penetration. SAE Paper 710571Desantes JM, Payri R, Salvador FJ, Gil A (2006a) Deduction and validation of a theoretical model for a free diesel Spray. Fuel 85:910–917Desantes JM, Arrègle J, López JJ, Cronhjort A (2006b) Scaling laws for free turbulent gas jets and Diesel-like sprays. Atomization Spray 16:443–473Desantes JM, Payri R, García JM, Salvador FJ (2007) A contribution to the understanding of isothermal diesel spray dynamics. Fuel 86:1093–1101Dumouchel C (2008) On the experimental investigation on primary atomization of liquid streams. Exp Fluids 45:371–422Heimgärtner C, Leipertz A (2000) of the primary spray break-up close to the nozzle of a common-rail high pressure diesel injection system. SAE Paper 2000-01-1799Hinze JO (1975) Turbulence. McGraw Hill, New YorkHiroyasu H, Arai M (1990) Structures of fuel sprays in diesel engines. SAE Paper 900475Jawad B, Gulari E, Henein NA (1992) Characteristics of intermittent fuel sprays. Combust Flame 88:384–396Lefèbvre AH (1989) Atomization and sprays. Hemisphere, New YorkLeick P, Riedel T, Bittlinger G, Powell CF, Kastengren AL, Wang J (2007) X-Ray measurements of the mass distribution in the dense primary break-up region of the spray from a standard multi-hole common-rail diesel injection system. In: Proc 21st ILASS (Europe)Linne M, Paciaroni M, Hall T, Parker T (2006) Ballistic imaging of the near field in a diesel spray. Exp Fluids 40:836–846Naber J, Siebers DL (1996) Effects of gas density and vaporisation on penetration and dispersion of diesel sprays. SAE Paper 960034Payri F, Bermúdez V, Payri R, Salvador FJ (2004) The influence of cavitation on the internal flow and the Spray characteristics in diesel injection nozzles. Fuel 83:419–431Payri R, García JM, Salvador FJ, Gimeno J (2005) Using spray momentum flux measurements to understand the influence of diesel nozzle geometry on spray characteristics. Fuel 84:551–561Payri R, Tormos B, Salvador FJ, Araneo L (2008) Spray droplet velocity characterization for convergent nozzles with three different diameters. Fuel 87:3176–3182Post S, Iyer V, Abraham J (2000) A study of near-field entrainment in gas jets and sprays under diesel conditions. ASME J Fluids Eng 122:385–395Prasad CMV, Kar S (1976) An investigation on the diffusion of momentum and mass of fuel in a diesel fuel spray. ASME J Eng Power 76-DGP-1:1–11Rajaratnam N (1976) Turbulent jets. Elsevier, AmsterdamRamirez AI, Som S, Aggarwal SK, Kastengren AL, El-Hannouny EM, Longman DE, Powell CF (2009) Quantitative X-ray measurements of high-pressure fuel sprays from a production heavy duty diesel injector. Exp Fluids 47:119–134Reitz RD, Bracco FV (1982) Mechanism of atomisation of a liquid jet. Phys Fluids 25(10):1730–1742Ricou FP, Spalding DB (1961) Measurements of entrainment by axisymmetrical turbulent jets. J Fluid Mech 11:21–32Rife J, Heywood JB (1974) Photographic and performance studies of diesel combustion with a rapid compression machine. SAE Paper 740948Roisman IV, Tropea C (2001) Flux measurements in sprays using phase doppler techniques. Atomization Spray 11:667–699Roisman IV, Araneo L, Tropea C (2007) Effect of ambient pressure on penetration of a diesel spray. Int J Multiphase Flow 33(8):904–920Saliba R, Baz I, Champoussin JC, Lance M, Marié JL (2004) Cavitation effect on the near nozzle spray development in high-pressure diesel injection. In: Proc 19th ILASS (Europe)Schlichting H (1978) Boundary layer theory. McGraw Hill, New YorkSinnamon JF, Lancaster DR, Stiener JC (1980) An experimental and analytical study of engine fuel spray trajectories. SAE Paper 800135Sou A, Hosokawa S, Tomiyama A (2007) Effects of cavitation in a nozzle on liquid jet atomization. Int J Heat Mass Tran 50(17–18):3575–3582Spalding DB (1979) Combustion and mass transfer. Pergamon Press, New YorkSubramaniam S (2001) Statistical modelling of a spray as using the droplet distribution function. Phys Fluids 13(3):624–642Tanner FX, Feigl A, Ciatti SA, Powell CF, Cheong S-K, Liu J, Wang J (2006) Structure of high-velocity dense sprays in the near-nozzle region. Atomization Spray 16:579–597Way RJB (1977) Investigation of interaction between swirl and jets in direct injection diesel engines using a water model. SAE Paper 770412Wu KJ, Santavicca DA, Bracco FV (1984) LDV measurements of drop velocity in diesel-type sprays. AAIA J 22(9):1263–1270Wu KJ, Reitz RD, Bracco FV (1986) Measurements of drop size at the spray edge near the nozzle in atomising liquid jets. Phys Fluids 29(4):941–951Yue Y, Powell CF, Poola R, Wang J, Schaller JK (2001) Quantitative measurements of diesel fuel spray characteristics in the near-nozzle region using X-ray absorption. Atomization Spray 11(4):471–49

    Phase II trial of sequential gefitinib after minor response or partial response to chemotherapy in Chinese patients with advanced non-small-cell lung cancer

    Get PDF
    BACKGROUND: Basic research of gefitinib (Iressa, ZD1839) has demonstrated the combination effects of gefitinib and chemotherapy were sequence-dependent. To evaluate the efficacy of sequential administration of gefitinib following a minor response or partial response to two to three cycles of chemotherapy, a phase II clinical trial was done in Chinese patients with advanced non-small-cell lung cancer (NSCLC). METHODS: Thirty-three consecutive patients with advanced NSCLC that had been pretreated with at least one chemotherapeutic regimen and were responding to chemotherapy following 2 to 3 cycles of treatment, entered the trial from May 2004 to February 2006. Patients received gefitinib at an oral dose of 250 mg once daily for 4 weeks. RESULTS: Thirty-three patients were evaluable for response and toxicity. The objective response rate was 24.2% (8 of 33)(95% CI, 11% to 42%). The symptom improvement rate was 54.5% (18 of 33) (95% CI, 41% to 69%). The median duration of response was 7 months (95%CI, 4.0 to 13.2 months). The median time to disease progression (TTP) was 6.5 months (95%CI, 0.7 to 16.6 months). The median overall survival time (OS) was 9.8 months (range, 2.1 to 18.0 months), and the actuarial 1-year survival was 36.4%. Toxicity was relatively mild and included only one patient (3.0%) with grade 4 diarrhea, 1 (3.0%) with grade 3 rash, 1 (3.0%) with grade 3 nausea, and 1 with grade 3 vomiting (3.0%). CONCLUSION: Preliminary results suggest that sequential administration of gefitinib following a response to chemotherapy may be beneficial for Chinese patients with advanced NSCLC. Further randomized clinical trials are needed
    corecore