1,191 research outputs found
Online-offline activities and game-playing behaviors of avatars in a massive multiplayer online role-playing game
Massive multiplayer online role-playing games (MMORPGs) are very popular in
China, which provides a potential platform for scientific research. We study
the online-offline activities of avatars in an MMORPG to understand their
game-playing behavior. The statistical analysis unveils that the active avatars
can be classified into three types. The avatars of the first type are owned by
game cheaters who go online and offline in preset time intervals with the
online duration distributions dominated by pulses. The second type of avatars
is characterized by a Weibull distribution in the online durations, which is
confirmed by statistical tests. The distributions of online durations of the
remaining individual avatars differ from the above two types and cannot be
described by a simple form. These findings have potential applications in the
game industry.Comment: 6 EPL pages including 10 eps figure
DeepVar: An End-to-End Deep Learning Approach for Genomic Variant Recognition in Biomedical Literature
We consider the problem of Named Entity Recognition (NER) on biomedical
scientific literature, and more specifically the genomic variants recognition
in this work. Significant success has been achieved for NER on canonical tasks
in recent years where large data sets are generally available. However, it
remains a challenging problem on many domain-specific areas, especially the
domains where only small gold annotations can be obtained. In addition, genomic
variant entities exhibit diverse linguistic heterogeneity, differing much from
those that have been characterized in existing canonical NER tasks. The
state-of-the-art machine learning approaches in such tasks heavily rely on
arduous feature engineering to characterize those unique patterns. In this
work, we present the first successful end-to-end deep learning approach to
bridge the gap between generic NER algorithms and low-resource applications
through genomic variants recognition. Our proposed model can result in
promising performance without any hand-crafted features or post-processing
rules. Our extensive experiments and results may shed light on other similar
low-resource NER applications.Comment: accepted by AAAI 202
An evolutionary algorithm with double-level archives for multiobjective optimization
Existing multiobjective evolutionary algorithms (MOEAs) tackle a multiobjective problem either as a whole or as several decomposed single-objective sub-problems. Though the problem decomposition approach generally converges faster through optimizing all the sub-problems simultaneously, there are two issues not fully addressed, i.e., distribution of solutions often depends on a priori problem decomposition, and the lack of population diversity among sub-problems. In this paper, a MOEA with double-level archives is developed. The algorithm takes advantages of both the multiobjective-problemlevel and the sub-problem-level approaches by introducing two types of archives, i.e., the global archive and the sub-archive. In each generation, self-reproduction with the global archive and cross-reproduction between the global archive and sub-archives both breed new individuals. The global archive and sub-archives communicate through cross-reproduction, and are updated using the reproduced individuals. Such a framework thus retains fast convergence, and at the same time handles solution distribution along Pareto front (PF) with scalability. To test the performance of the proposed algorithm, experiments are conducted on both the widely used benchmarks and a set of truly disconnected problems. The results verify that, compared with state-of-the-art MOEAs, the proposed algorithm offers competitive advantages in distance to the PF, solution coverage, and search speed
The theoretical direct-band-gap optical gain of Germanium nanowires
We calculate the electronic structures of Germanium nanowires by taking the
effective-mass theory. The electron and hole states at the G-valley are studied
via the eight-band k.p theory. For the [111] L-valley, we expand the envelope
wave function using Bessel functions to calculate the energies of the electron
states for the first time. The results show that the energy dispersion curves
of electron states at the L-valley are almost parabolic irrespective of the
radius of Germanium nanowires. Based on the electronic structures, the density
of states of Germanium nanowires are also obtained, and we find that the
conduction band density of states mostly come from the electron states at the
L-valley because of the eight equivalent degenerate L points in Germanium.
Furthermore, the optical gain spectra of Germanium nanowires are investigated.
The calculations show that there are no optical gain along z direction even
though the injected carrier density is 4x1019 cm-3 when the doping
concentration is zero, and a remarkable optical gain can be obtained when the
injected carrier density is close to 1x1020 cm-3, since a large amount of
electrons will prefer to occupy the low-energy L-valley. In this case, the
negative optical gain will be encountered considering free-carrier absorption
loss as the increase of the diameter. We also investigate the optical gain
along z direction as functions of the doping concentration and injected carrier
density for the doped Germanium nanowires. When taking into account
free-carrier absorption loss, the calculated results show that a positive net
peak gain is most likely to occur in the heavily doped nanowires with smaller
diameters. Our theoretical studies are valuable in providing a guidance for the
applications of Germanium nanowires in the field of microelectronics and
optoelectronics
Division of labor, skill complementarity, and heterophily in socioeconomic networks
Constituents of complex systems interact with each other and self-organize to
form complex networks. Empirical results show that the link formation process
of many real networks follows either the global principle of popularity or the
local principle of similarity or a tradeoff between the two. In particular, it
has been shown that in social networks individuals exhibit significant
homophily when choosing their collaborators. We demonstrate, however, that in
populations in which there is a division of labor, skill complementarity is an
important factor in the formation of socioeconomic networks and an individual's
choice of collaborators is strongly affected by heterophily. We analyze 124
evolving virtual worlds of a popular "massively multiplayer online role-playing
game" (MMORPG) in which people belong to three different professions and are
allowed to work and interact with each other in a somewhat realistic manner. We
find evidence of heterophily in the formation of collaboration networks, where
people prefer to forge social ties with people who have professions different
from their own. We then construct an economic model to quantify the heterophily
by assuming that individuals in socioeconomic systems choose collaborators that
are of maximum utility. The results of model calibration confirm the presence
of heterophily. Both empirical analysis and model calibration show that the
heterophilous feature is persistent along the evolution of virtual worlds. We
also find that the degree of complementarity in virtual societies is positively
correlated with their economic output. Our work sheds new light on the
scientific research utility of virtual worlds for studying human behaviors in
complex socioeconomic systems.Comment: 14 Latex pages + 3 figure
Brain natriuretic peptide suppresses pain induced by BmK I, a sodium channel-specific modulator, in rats.
Background: A previous study found that brain natriuretic peptide (BNP) inhibited inflammatory pain via activating its receptor natriuretic peptide receptor A (NPRA) in nociceptive sensory neurons. A recent study found that functional NPRA is expressed in almost all the trigeminal ganglion (TG) neurons at membrane level suggesting a potentially important role for BNP in migraine pathophysiology. Methods: An inflammatory pain model was produced by subcutaneous injection of BmK I, a sodium channel-specific modulator from venom of Chinese scorpion Buthus martensi Karsch. Quantitative PCR, Western Blot, and immunohistochemistry were used to detect mRNA and protein expression of BNP and NPRA in dorsal root ganglion (DRG) and dorsal horn of spinal cord. Whole-cell patch clamping experiments were conducted to record large-conductance Ca2+-activated K+ (BKCa) currents of membrane excitability of DRG neurons. Spontaneous and evoked pain behaviors were examined. Results: The mRNA and protein expression of BNP and NPRA was up-regulated in DRG and dorsal horn of spinal cord after BmK I injection. The BNP and NPRA was preferentially expressed in small-sized DRG neurons among which BNP was expressed in both CGRP-positive and IB4-positive neurons while NPRA was preferentially expressed in CGRP-positive neurons. BNP increased the open probability of BKCa channels and suppressed the membrane excitability of small-sized DRG neurons. Intrathecal injection of BNP significantly inhibited BmK-induced pain behaviors including both spontaneous and evoked pain behaviors. Conclusions: These results suggested that BNP might play an important role as an endogenous pain reliever in BmK I-induced inflammatory pain condition. It is also suggested that BNP might play a similar role in other pathophysiological pain conditions including migraine
Boty-like retrotransposons in the filamentous fungus Botrytis cinerea contain the additional antisense gene brtn
AbstractLong-terminal repeat (LTR) retrotransposons typically contain gag, pol, or gag–pol, and in some case env genes. In this work, we used data mining of the Botrytis cinerea genomic sequence and a molecular approach to identify Boty-like LTR retrotransposons in B. cinerea containing an antisense gene (brtn) between pol and the 3′-LTR. Reverse transcriptase PCR (RT-PCR) revealed that some brtn-like genes could be expressed, at least in B. cinerea T4. We conducted BLAST comparisons and conserved-domain analysis, but the function of putative BRTN is presently unknown. Boty-like LTR retrotransposons in Sclerotinia sclerotiorum, called ScscLRET and containing brtn homologs at positions similar to brtn, were detected by homology searches and data mining of the S. sclerotiorum 1980 genomic sequence. Thus, this study demonstrated that some fungal LTR retrotransposons contain additional antisense genes
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