2,765 research outputs found
YouTube AV 50K: An Annotated Corpus for Comments in Autonomous Vehicles
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
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
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
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
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 System and the Resonance-like Structure
In this paper, low-energy scattering of the meson
system is studied within L\"uscher's finite-size formalism using
twisted mass gauge field configurations. With three different pion mass values,
the -wave threshold scattering parameters, namely the scattering length
and the effective range , are extracted in 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
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
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
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
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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