6,811 research outputs found
Stable Heteronuclear Few-Atom Bound States in Mixed Dimensions
We study few-body problems in mixed dimensions with heavy atoms
trapped individually in parallel one-dimensional tubes or two-dimensional
disks, and a single light atom travels freely in three dimensions. By using the
Born-Oppenheimer approximation, we find three- and four-body bound states for a
broad region of heavy-light atom scattering length combinations. Specifically,
the existence of trimer and tetramer states persist to negative scattering
lengths regime, where no two-body bound state is present. These few-body bound
states are analogous to the Efimov states in three dimensions, but are stable
against three-body recombination due to geometric separation. In addition, we
find that the binding energy of the ground trimer and tetramer state reaches
its maximum value when the scattering lengths are comparable to the separation
between the low-dimensional traps. This resonant behavior is a unique feature
for the few-body bound states in mixed dimensions.Comment: Extended version with 14 pages and 14 figure
A COMPARISON OF SINGLE- AND DOUBLE-LEG RUNNING VERTICAL JUMPS IN VOLLEYBALL
Single- and double-leg vertical jumps are often performed in volleyball games. But the contribution from individual leg in single- and double-leg running vertical jump skills in volleyball has not been revealed. The purpose of this study was to determine the differences between single- and double- leg running vertical jumps (1-LRVJ and 2-LRVJ) on the biomechanical characteristics. Ten male college volleyball players voluntarily participated in this study. Two volleyball running vertical jumps were executed randomly. Three trials of each running vertical jump were recorded for each subject. Data were collected using six infra-red Qualisys motion capture cameras at 180 Hz sampling rate and two AMTI force platforms at 1800 Hz sampling rate, respectively. The jump height of 2-LRVJ was significantly higher than 1-LRVJ (P< .05), In push-off phase, 1-LRVJ had less angle change, but greater moment and higher impact force (P< .05). These results suggested that 1-LRVJ product higher leg stiffness with 2-LRVJ, it also increase higher risk of injury. We suggested using two- leg jumping style to enhance jump high, and avoid lower limbs injury
Contextual Label Projection for Cross-Lingual Structure Extraction
Translating training data into target languages has proven beneficial for
cross-lingual transfer. However, for structure extraction tasks, translating
data requires a label projection step, which translates input text and obtains
translated labels in the translated text jointly. Previous research in label
projection mostly compromises translation quality by either facilitating easy
identification of translated labels from translated text or using word-level
alignment between translation pairs to assemble translated phrase-level labels
from the aligned words. In this paper, we introduce CLAP, which first
translates text to the target language and performs contextual translation on
the labels using the translated text as the context, ensuring better accuracy
for the translated labels. We leverage instruction-tuned language models with
multilingual capabilities as our contextual translator, imposing the constraint
of the presence of translated labels in the translated text via instructions.
We compare CLAP with other label projection techniques for creating
pseudo-training data in target languages on event argument extraction, a
representative structure extraction task. Results show that CLAP improves by
2-2.5 F1-score over other methods on the Chinese and Arabic ACE05 datasets.Comment: Work in Progres
Recommended from our members
The Lopsided Distribution of Satellites of Isolated Central Galaxies
Satellites are not randomly distributed around their central galaxies but show polar and planar structures. In this paper, we investigate the axis asymmetry or lopsidedness of satellite galaxy distributions around isolated galaxies in a hydrodynamic cosmological simulation. We find a statistically significant lopsided signal by studying the angular distribution of the satellite galaxies' projected positions around isolated central galaxies in a two-dimensional plane. The signal is dependent on galaxy mass, color, and large-scale environment. Satellites that inhabit low-mass blue hosts, or located further from the hosts, show the most lopsided signal. Galaxy systems with massive neighbors exhibit stronger lopsidedness. This satellite axis-asymmetry signal also decreases as the universe evolves. Our findings are in agreement with recent observational results and they provide a useful perspective for studying galaxy evolution, especially on the satellite accretion, internal evolution, and interaction with the cosmic large-scale structure. © 2021. The Author(s). Published by the American Astronomical Society.
Synthesis of benzonaphthofuroquinones and benzoylnaphthindolizinediones by reactions of flavonoids with dichlone under basylous, oxygenous and aqueous conditions: Their cytotoxic and apoptotic activities
© 2020 The Royal Society of Chemistry. Using flavonoids and dichlone as substrates, benzonaphthofuroquinones (1, 2, 3, 5, 6, novel; 4 new) and benzoylnaphthindolizinediones (7, 8, known; 9, new) were synthesized through common base-catalyzed method and a new method of combining base-catalyzed with O2/H2O exposing. The possible reaction mechanisms may involve the process like isomerization, hydration, oxidation, decomposition and intermolecular condensation. Benzonaphthofuroquinones (2, 3, 4, 5) were found to exhibit potent cytotoxicity against carcinoma cell lines and low toxicity to normal cell lines. The compounds 4 and 5 not only expressed a significant late-stage-apoptosis against human leukemia and melanoma, but also promoted the cleavage of caspase-3 and PARP in human leukemia, which suggested that the late-stage-apoptosis and caspase-3 pathway may be responsible for the cytotoxicities of these benzonaphthofuroquinones. The replacement of the furan ring with pyrrole system in benzoylnaphthindolizinediones (7, 8, 9) resulted in the loss of anticancer activity
The Untranslated Regions of Classic Swine Fever Virus RNA Trigger Apoptosis
Classical swine fever virus (CSFV) causes a broad range of disease in pigs, from acute symptoms including high fever and hemorrhages, to chronic disease or unapparent infection, depending on the virus strain. CSFV belongs to the genus Pestivirus of the family Flaviviridae. It carries a single-stranded positive-sense RNA genome. An internal ribosomal entry site (IRES) in the 5' untranslated region (UTR) drives the translation of a single open reading frame encoding a 3898 amino acid long polypeptide chain. The open reading frame is followed by a 3' UTR comprising four highly structured stem-loops. In the present study, a synthetic RNA composed of the 5' and 3' UTRs of the CSFV genome devoid of any viral coding sequence and separated by a luciferase gene cassette (designated 5'UTR-Luc-3'UTR) triggered apoptotic cell death as early as 4 h post-transfection. The apoptosis was measured by DNA laddering analysis, TUNEL assay, annexin-V binding determined by flow cytometry, and by analysis of caspase activation. Contrasting with this, only trace DNA laddering was observed in cells transfected with the individual 5' or 3' UTR RNA; even when the 5' UTR and 3' UTR were co-transfected as separate RNA molecules, DNA laddering did not reach the level induced by the chimeric 5'UTR-Luc-3'UTR RNA. Interestingly, RNA composed of the 5'UTR and of stem-loop I of the 3'UTR triggered much stronger apoptosis than the 5' or 3'UTR alone. These results indicate that the 5' and 3' UTRs act together in cis induce apoptosis. We furthered obtained evidence that the UTR-mediated apoptosis required double-stranded RNA and involved translation shutoff possibly through activation of PKR
Paired SSB optical OFDM channels for high spectral efficient signal transmission over DWDM networks
[EN] A new high spectral efficient SSB-OOFDM DWDM transmission system has been experimentally demonstrated.
The proposed transmitter employs paired optical channels consisting of two SSB modulated
OFDM signals using opposite sidebands in order to allow an efficient use of the spectrum with optical
carriers separation under 10 GHz. Moreover, different paired channels are multiplexed into the 25 GHz
grid DWDM fiber transmission link. Optical carrier spacing of 8.75 GHz in paired channels has been
demonstrated allowing 40.8 Gb/s signal transmission rate over a 25 GHz paired channel bandwidth.The research leading to these results has received funding from the national project TEC2011-26642 (NEWTON) funded by the Ministerio de Ciencia y TecnologĂa and the Research Excellency Award Programme GVA PROMETEO 2013/012NEXT GENERATION MICROWAVE PHOTONIC TECHNOLOGIES.Chicharro LĂłpez, FI.; Ortega Tamarit, B.; Mora Almerich, J. (2016). Paired SSB optical OFDM channels for high spectral efficient signal transmission over DWDM networks. Optics Communications. 370:239-244. https://doi.org/10.1016/j.optcom.2016.03.007S23924437
Probing Shadowed Nuclear Sea with Massive Gauge Bosons in the Future Heavy-Ion Collisions
The production of the massive bosons and could provide an
excellent tool to study cold nuclear matter effects and the modifications of
nuclear parton distribution functions (nPDFs) relative to parton distribution
functions (PDFs) of a free proton in high energy nuclear reactions at the LHC
as well as in heavy-ion collisions (HIC) with much higher center-of mass
energies available in the future colliders. In this paper we calculate the
rapidity and transverse momentum distributions of the vector boson and their
nuclear modification factors in p+Pb collisions at TeV and in
Pb+Pb collisions at TeV in the framework of perturbative QCD
by utilizing three parametrization sets of nPDFs: EPS09, DSSZ and nCTEQ. It is
found that in heavy-ion collisions at such high colliding energies, both the
rapidity distribution and the transverse momentum spectrum of vector bosons are
considerably suppressed in wide kinematic regions with respect to p+p reactions
due to large nuclear shadowing effect. We demonstrate that in the massive
vector boson productions processes with sea quarks in the initial-state may
give more contributions than those with valence quarks in the initial-state,
therefore in future heavy-ion collisions the isospin effect is less pronounced
and the charge asymmetry of W boson will be reduced significantly as compared
to that at the LHC. Large difference between results with nCTEQ and results
with EPS09 and DSSZ is observed in nuclear modifications of both rapidity and
distributions of and in the future HIC.Comment: 13 pages, 21 figures, version accepted for publication in Eur. Phys.
J.
- …