8,653 research outputs found
The impact of tourism quality on economic development and environment:Evidence from Mediterranean countries
This paper is the first of its kind to measure the income level of a country’s tourist arrival and empirically examine its impact on economic growth and environmental pollution in a sample of eight Mediterranean countries. The paper undertakes annual data from 1995 to 2014 and employs quantile regression models, autoregressive distributed lag (ARDL) estimations, and a heterogeneity causality test. The empirical results show that the income level of a country’s tourist arrival, across all quantiles, plays an important role in promoting economic development. However, the role of the income level of a country’s tourist arrival on environmental pollution varies with the changes in quantiles. More specifically, income level of a country’s tourist arrival has a positive impact on environmental pollution for the lower quantiles, while it has a negative impact for higher quantiles. The findings from panel ARDL models confirm that the income level of a country’s tourist arrival has positive and negative impacts on economic growth and emissions, respectively. Given these results, these findings provide information to take the necessary actions to ensure sustainable tourism development, i.e., the expansion of the tourism industry without harming the environment in the Mediterranean countries. <br/
Structural Bias for Aspect Sentiment Triplet Extraction
Structural bias has recently been exploited for aspect sentiment triplet
extraction (ASTE) and led to improved performance. On the other hand, it is
recognized that explicitly incorporating structural bias would have a negative
impact on efficiency, whereas pretrained language models (PLMs) can already
capture implicit structures. Thus, a natural question arises: Is structural
bias still a necessity in the context of PLMs? To answer the question, we
propose to address the efficiency issues by using an adapter to integrate
structural bias in the PLM and using a cheap-to-compute relative position
structure in place of the syntactic dependency structure. Benchmarking
evaluation is conducted on the SemEval datasets. The results show that our
proposed structural adapter is beneficial to PLMs and achieves state-of-the-art
performance over a range of strong baselines, yet with a light parameter demand
and low latency. Meanwhile, we give rise to the concern that the current
evaluation default with data of small scale is under-confident. Consequently,
we release a large-scale dataset for ASTE. The results on the new dataset hint
that the structural adapter is confidently effective and efficient to a large
scale. Overall, we draw the conclusion that structural bias shall still be a
necessity even with PLMs.Comment: 10 pages, 4 figures, 5 tables, accepted to COLING 2022, code is
available at https://github.com/GeneZC/StructBia
Effects of metastasis-associated in colon cancer 1 inhibition by small hairpin RNA on ovarian carcinoma OVCAR-3 cells
<p>Abstract</p> <p>Background</p> <p>Metastasis-associated in colon cancer 1 (MACC1) is demonstrated to be up-regulated in several types of cancer, and can serve as biomarker for cancer invasion and metastasis. To investigate the relations between MACC1 and biological processes of ovarian cancer, MACC1 specific small hairpin RNA (shRNA) expression plasmids were used to investigate the effects of MACC1 inhibition on ovarian carcinoma OVCAR-3 cells.</p> <p>Methods</p> <p>Expressions of MACC1 were detected in different ovarian tissues by immunohistochemistry. MACC1 specific shRNA expression plasmids were constructed and transfected into OVCAR-3 cells. Then, expressions of MACC1 were examined by reverse transcription polymerase chain reaction (RT-PCR) and Western blot. Cell proliferation was observed by MTT and monoplast colony formation assay. Flow cytometry and TUNEL assay were used to measure cell apoptosis. Cell migration was assessed by wound healing and transwell migration assay. Matrigel invasion and xenograft model assay were performed to analyze the potential of cell invasion. Activities of Met, MEK1/2, ERK1/2, Akt, cyclinD1, caspase3 and MMP2 protein were measured by Western blot.</p> <p>Results</p> <p>Overexpressions of MACC1 were detected in ovarian cancer tissues. Expression of MACC1 in OVCAR-3 cells was significantly down-regulated by MACC1 specific small hairpin RNA. In OVCAR-3 cells, down-regulation of MACC1 resulted in significant inhibition of cell proliferation, migration and invasion, meanwhile obvious enhancement of apoptosis. As a consequence of MACC1 knockdown, expressions of Met, p-MEK1/2, p-ERK1/2, cyclinD1 and MMP2 protein decreased, level of cleaved capase3 was increased.</p> <p>Conclusions</p> <p>RNA interference (RNAi) against MACC1 could serve as a promising intervention strategy for gene therapy of ovarian carcinoma, and the antitumor effects of MACC1 knockdown might involve in the inhibition of HGF/Met and MEK/ERK pathways.</p
Polarization-independent liquid crystal phase modulator using a thin polymer-separated double-layered structure
A polarization-independent phase-only liquid crystal (LC) phase modulator using a double-layered structure is demonstrated. Two orthogonal LC layers are separated by two ultra-thin anisotropic polymer films. The anisotropic polymeric films not only separate the LC layers but also provide good molecular alignment. As a result, a polarization-independent phase modulator with 2 pi phase shift is achieved at 9V(rms) and 8.1 pi at 40V(rms) using a 12-mu m-thick E7 LC layers. This operating voltage is similar to 10X lower than that using a conventional 0.3-mm-thick glass separator
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Contrasting size-resolved hygroscopicity of fine particles derived by HTDMA and HR-ToF-AMS measurements between summer and winter in Beijing: the impacts of aerosol aging and local emissions
Electrically tunable wettability of liquid crystal/polymer composite films
An electrically tunable wettability in a liquid crystal/polymer composite film is demonstrated, in which liquid crystal molecules are anchored among polymer grains. The tunable wettability of the composite films originates from the reorientation of the anchored liquid-crystal molecules, which is switched by an in-plane electric field with squared pulses of voltages. These liquid crystal/polymer composite films with electrically tunable wettability have potential applications in polarizer-free displays, ink-jet printing, microfluidic devices, and lab-on-a-chip
The Photometric System of Tsinghua-NAOC 80-cm Telescope at NAOC Xinglong Observatory
Tsinghua-NAOC (National Astronomical Observatories of China) Telescope
(hereafter, TNT) is an 80-cm Cassegrain reflecting telescope located at
Xinglong bservatory of NAOC, with main scientific goals of monitoring various
transients in the universe such as supernovae, gamma-ray bursts, novae,
variable stars, and active galactic nuclei. We present in this paper a
systematic test and analysis of the photometric performance of this telescope.
Based on the calibration observations on twelve photometric nights, spanning
the period from year 2004 to year 2012, we derived an accurate transformation
relationship between the instrumental magnitudes and standard Johnson
and Cousins magnitudes. In particular, the color terms and the
extinction coefficients of different passbands are well determined. With these
data, we also obtained the limiting magnitudes and the photometric precision of
TNT. It is worthwhile to point out that the sky background at Xinglong
Observatory may become gradually worse over the period from year 2005 to year
2012 (e.g., 21.4 mag vs. 20.1 mag in the V band).Comment: 12 pages,9 figures, accepted by RA
Superconductivity induced by oxygen deficiency in Sr-doped LaOFeAs
We synthesized Sr-doped sample with single phase,
and systematically studied the effect of oxygen deficiency in the Sr-doped
LaOFeAs system. It is found that substitution of Sr for La indeed induces the
hole carrier evidenced by positive thermoelectric power (TEP), but no bulk
superconductivity is observed. The superconductivity can be realized by
annealing the as-grown sample in vacuum to produce the oxygen deficiency. With
increasing the oxygen deficiency, the superconducting transition temperature
() increases and maximum reaches about 26 K the same as that in
La(O,F)FeAs. TEP dramatically changes from positive to negative in the
nonsuperconducting as-grown sample to the superconducting samples with oxygen
deficiency. While is always negative for all samples (even for Sr-doped
as grown sample). It suggests that the is
still electron-type superconductor.Comment: 4 pages, 4 figure
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