2,765 research outputs found

    YouTube AV 50K: An Annotated Corpus for Comments in Autonomous Vehicles

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    With one billion monthly viewers, and millions of users discussing and sharing opinions, comments below YouTube videos are rich sources of data for opinion mining and sentiment analysis. We introduce the YouTube AV 50K dataset, a freely-available collections of more than 50,000 YouTube comments and metadata below autonomous vehicle (AV)-related videos. We describe its creation process, its content and data format, and discuss its possible usages. Especially, we do a case study of the first self-driving car fatality to evaluate the dataset, and show how we can use this dataset to better understand public attitudes toward self-driving cars and public reactions to the accident. Future developments of the dataset are also discussed.Comment: in Proceedings of the Thirteenth International Joint Symposium on Artificial Intelligence and Natural Language Processing (iSAI-NLP 2018

    An Unexpected Deamination Reaction after Hydrolysis of the Pyrimidine (6-4) Pyrimidone Photoproduct

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    Pyrimidine (6-4) pyrimidone photoproduct (6-4PP), a common DNA photolesion formed under solar irradiation, was indicated to hydrolyze under strong basic conditions, breaking the N3–C4 bond at the 5′-thymine. The reanalysis of this reaction revealed that the resulting water adduct may not be stable as previously proposed; it readily undergoes an esterification reaction induced by the 5-OH group at 6-4PP to form a five-membered ring, eliminating a molecule of ammonia

    Temperature-pressure phase diagram of confined monolayer water/ice at first-principles accuracy with a machine-learning force field

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    Understanding the phase behaviour of nanoconfined water films is of fundamental importance in broad fields of science and engineering. However, the phase behaviour of the thinnest water film – monolayer water – is still incompletely known. Here, we developed a machine-learning force field (MLFF) at first-principles accuracy to determine the phase diagram of monolayer water/ice in nanoconfinement with hydrophobic walls. We observed the spontaneous formation of two previously unreported high-density ices, namely, zigzag quasi-bilayer ice (ZZ-qBI) and branched-zigzag quasi-bilayer ice (bZZ-qBI). Unlike conventional bilayer ices, few inter-layer hydrogen bonds were observed in both quasi-bilayer ices. Notably, the bZZ-qBI entails a unique hydrogen-bonding network that consists of two distinctive types of hydrogen bonds. Moreover, we identified, for the first time, the stable region for the lowest-density 4 . 82 monolayer ice (LD-48MI) at negative pressures (\u3c −0.3 GPa). Overall, the MLFF enables large-scale first-principle-level molecular dynamics (MD) simulations of the spontaneous transition from the liquid water to a plethora of monolayer ices, including hexagonal, pentagonal, square, zigzag (ZZMI), and hexatic monolayer ices. These findings will enrich our understanding of the phase behaviour of the nanoconfined water/ices and provide a guide for future experimental realization of the 2D ices

    Virus efficacy of recombined Autographa californica M nucleopolyhedrovirus (AcMNPV) on tea pest Ectropis obliqua

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    Ectropis obliqua is a major tea pest and chitin synthase (CHS) plays a key role in the pest growth and development. A 192 bp conserved domain from E. obliqua CHS gene was cloned and it was used to construct recombined Autographa californica M nucleopolyhedrovirus (AcMNPV) with double-stranded RNA interference (dsRNAi) method. The recombined AcMNPV virus could propagate in host cells sf9. Injection test showed that the virus efficacy of the recombined AcMNPV on E. obliqua larvae was significantly enhanced. It is considered that the CHS dsRNAi mediated by the nuclear polyhedrosis virus will be interesting for development of alternative bio-pesticide to control the tea pest E. obliqua.Keywords: Chitin synthase, baculovirus, double-stranded RNA interference, Ectropis obliquaAfrican Journal of Biotechnology Vol. 9(33), pp. 5412-5418, 16 August, 201

    Unusually Large Deuterium Discrimination during Spore Photoproduct Formation

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    The deuterium-labeling strategy has been widely used and proved highly effective in mechanistic investigation of chemical and biochemical reactions. However, it is often hampered by the incomplete label transfer, which subsequently obscures the mechanistic conclusion. During the study of photoinduced generation of 5-thyminyl-5,6-dihydrothymine, which is commonly called the spore photoproduct (SP), the Cadet laboratory found an incomplete (∼67%) deuterium transfer in SP formation, which contrasts to the exclusive transfer observed by the Li laboratory. Here, we investigated this discrepancy by re-examining the SP formation using d3-thymidine. We spiked the d3-thymidine with varying amounts of unlabeled thymidine before the SP photochemistry is performed. Strikingly, our data show that the reaction is highly sensitive to the trace protiated thymidine in the starting material. As many as 17-fold enrichment is detected in the formed SP, which may explain the previously observed one-third protium incorporation. Although commercially available deuterated reagents are generally satisfactory as mechanistic probes, our results argue that attention is still needed to the possible interference from the trace protiated impurity, especially when the reaction yield is low and large isotopic discrimination is involved

    Low-energy Scattering of (DDˉ)±(D^{*}\bar{D}^{*})^\pm System and the Resonance-like Structure Zc(4025)Z_c(4025)

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    In this paper, low-energy scattering of the (DDˉ)±(D^{*}\bar{D}^{*})^\pm meson system is studied within L\"uscher's finite-size formalism using Nf=2N_{f}=2 twisted mass gauge field configurations. With three different pion mass values, the ss-wave threshold scattering parameters, namely the scattering length a0a_0 and the effective range r0r_0, are extracted in JP=1+J^P=1^+ channel. Our results indicate that, in this particular channel, the interaction between the two vector charmed mesons is weakly repulsive in nature hence do not support the possibility of a shallow bound state for the two mesons, at least for the pion mass values being studied. This study provides some useful information on the nature of the newly discovered resonance-like structure Zc(4025)Z_c(4025) observed in various experiments.Comment: 11 pages, 6 figures. arXiv admin note: substantial text overlap with arXiv:1403.131

    Advances in the application of action learning in nursing practice

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    AbstractIn this paper, we elucidate the concept and characteristics of action learning as well as summarize the reflexivity, cooperativeness, and subjectivity of this approach. Furthermore, we describe the effects and limitations of action learning when applied in nursing management, nursing education, and clinical practice, among various fields

    Effect of siRNA interference on nerve growth factor in intervertebral disc inflammation rats

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    AbstractObjectiveTo investigate the inhibition effect of siRNA interference on NGF induced by inflammatory factor IL-6, and IL-1 so as to provide novel targets for clinical treatment of discogenic low back pain.MethodsThe intervertebral disc nucleus and annulus fibrosus cells of rats were separated. The cells were co-cultured with different concentrations (10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L) of IL-6 and IL-1β. The NGF-siRNA was leaded into the co-cultured cells with its import ability assessed by flow cytometry instrument tests, before and after which the NGF mRNA expression was detected by real-time Q-PCR and the NGF content was detected by ELISA.ResultsFlow cytometry instrument test results showed that the NGF-siRNA cell conversion rate was 99.8%. Real-time Q-PCR detection results showed that compared with negative control group, the NGF mRNA expression of co-cultured cells treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L IL-6 and IL-1β were respectively raised 3.4, 3.7, 4.7, 3.7 times which were all significantly down-regulated after the import of NGF-siRNA. EILSA detection results showed that compared with negative control group, the NGF content of co-cultured medium treated by 10 nmol/L, 20 nmol/L, 50 nmol/L, 100 nmol/L I-L6 and IL-1β were respectively raised 2.9, 3.3, 4.5, 7.4 times which were all significantly decreased after the import of NGF-siRNA.ConclusionsThese molecular biological results suggest that inflammatory factor IL-6 and IL-1β could stimulate NGF on intervertebral disc cells in vitro culture model and its efficiency is concentration dependent, while siRNA interference can inhibit the stimulation effect of IL-6 and IL-1β on intervertebral disc cell, which provides a new targets for the clinical treatment of discogenic low back pain

    Reactivity of Damaged Pyrimidines: DNA Cleavage via Hemiaminal Formation at the C4 Positions of the Saturated Thymine of Spore Photoproduct and Dihydrouridine

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    Described here are mechanistic details of the chemical reactivities of two modified/saturated pyrimidine residues that represent naturally occurring forms of DNA damage: 5-thyminyl-5,6-dihydrothymine, commonly referred to as the “spore photoproduct” (SP), and 5,6-dihydro-2′-deoxyuridine (dHdU), formed via ionizing radiation damage to cytosine under anoxic conditions and also serving as a general model of saturated pyrimidine residues. It is shown that due to the loss of the pyrimidine C5–C6 double bond and consequent loss of ring aromaticity, the C4 position of both these saturated pyrimidines is prone to the formation of a hemiaminal intermediate via water addition. Water addition is facilitated by basic conditions; however, it also occurs at physiological pH at a slower rate. The hemiaminal species so-formed subsequently converts to a ring-opened hydrolysis product through cleavage of the pyrimidine N3–C4 bond. Further decomposition of this ring-opened product above physiological pH leads to DNA strand break formation. Taken together, these results suggest that once the aromaticity of a pyrimidine residue is lost, the C4 position becomes a “hot spot” for the formation of a tetrahedral intermediate, the decay of which triggers a cascade of elimination reactions that can under certain conditions convert a simple nucleobase modification into a DNA strand break
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