436 research outputs found
A Hybrid Model for Monolingual and Multilingual Toxic Comment Detection
Social media provides a public and convenient platform for people to communicate. However, it is also open to hateful behavior and toxic comments. Social networks, like Facebook, Twitter, and many others, have been working on developing effective toxic comment detection methods to provide better service. Monolingual language model focuses on a single-language and provides high accuracy in detection. Multilingual language model provides better generalization performance. In order to improve the effectiveness of detecting toxic comments in multiple languages, we propose a hybrid model, which fuses monolingual model and multilingual model. We use labeled data to fine-tune the monolingual pre-trained model. We use masked language modeling to semi-supervise the fine-tuning of multilingual pre-trained model on unlabeled data and then use labeled data to fine-tune the model. Through this way, we can fully utilize the large amount of unlabeled data; reduce dependence on labeled comment data; and improve the effectiveness of detection. We also design several comparative experiments. The results demonstrate the effectiveness and advantage of our proposed model, especially compared to the XLM-RoBERTa multilingual fine-tuning model
Effects of the Aidi Dripping Pills on Immune Functions of the Tumor-bearing Mouse
ObjectiveTo study the effects of Aidi Dripping Pills on immune functions of the tumor-bearing mouse on the basis of the previous experimental studies on its tumor-inhibiting and life-prolonging effects.MethodsBy using the transplantation tumor mouse models, the effects of Aidi Dripping Pills on the lymphocyte transformation rate and the hemolysin formation in the S180 tumor-bearing mice, and on the phagocytic function of macrophages in the abdominal cavity of H22 tumor-bearing mice were investigated.ResultsIn the 2.25 g/kg and 1.125 g/kg Aidi Dripping Pills groups, the lymphocyte transformation rates in the S180 tumor-bearing mice were significantly higher than that of the control group (P<0.01). In all the Aidi Dripping Pills groups, HC50 significantly increased (P<0.01 or P<0.05), carbon granular clearance significantly raised, and both the phagocytic index and phagocytic coefficient were significantly higher than those in the control group (P<0.01 or P<0.05).ConclusionThe Aidi Dripping Pills can significantly increase the cellular immune function, the humoral immune function and the phagocytic function of the mononuclear-macrophages, so it may show anti-tumor effects by enhancing the function of the reticuloendothelial system
Double Dome and Reemergence of Superconductivity in Pristine 6R-TaS2 under Pressure
Investigating the implications of interlayer coupling on superconductivity is
essential for comprehending the intrinsic mechanisms of high temperature
superconductors. Van der Waals heterojunctions have attracted extensive
research due to their exotic interlayer coupling. Here, we present a natural
heterojunction superconductor of 6R-TaS2 that demonstrates a double-dome of
superconductivity, in addition to, the reemergence of superconducting under
high pressures. Our first principles calculation shows that the first dome of
superconductivity in 6R-TaS2 can be attributed to changes in interlayer
coupling and charge transfer. The second superconducting dome and the
reemergence of superconductivity can be ascribed to changes in the density of
states resulting from Fermi surface reconstruction, in which the DOS of T-layer
and S p-orbitals play a crucial role. We have reported the first observation in
TMDs that non-metallic atoms playing a dominant role in the reemergence of
superconducting and the influence of two Lifshitz transitions on
superconducting properties
Comparative transcriptomics in Yersinia pestis: a global view of environmental modulation of gene expression
<p>Abstract</p> <p>Background</p> <p>Environmental modulation of gene expression in <it>Yersinia pestis </it>is critical for its life style and pathogenesis. Using cDNA microarray technology, we have analyzed the global gene expression of this deadly pathogen when grown under different stress conditions <it>in vitro</it>.</p> <p>Results</p> <p>To provide us with a comprehensive view of environmental modulation of global gene expression in <it>Y. pestis</it>, we have analyzed the gene expression profiles of 25 different stress conditions. Almost all known virulence genes of <it>Y. pestis </it>were differentially regulated under multiple environmental perturbations. Clustering enabled us to functionally classify co-expressed genes, including some uncharacterized genes. Collections of operons were predicted from the microarray data, and some of these were confirmed by reverse-transcription polymerase chain reaction (RT-PCR). Several regulatory DNA motifs, probably recognized by the regulatory protein Fur, PurR, or Fnr, were predicted from the clustered genes, and a Fur binding site in the corresponding promoter regions was verified by electrophoretic mobility shift assay (EMSA).</p> <p>Conclusion</p> <p>The comparative transcriptomics analysis we present here not only benefits our understanding of the molecular determinants of pathogenesis and cellular regulatory circuits in <it>Y. pestis</it>, it also serves as a basis for integrating increasing volumes of microarray data using existing methods.</p
X-ray calibration of Dee voltage of radiofrequency cavity based on a low-power test
Radiofrequency cavity is one of the most critical and complicated components in a cyclotron. Dee voltage of radiofrequency cavity accelerates charged particles to achieve required energy. Peak voltage of Dee is the key parameter of an radiofrequency cavity. Balanced Dee voltage is very important for effective beam cantering and beam extracting. An X-ray measurement has been made to calibrate and verify the peak voltage of Dee in a low-power ( 20 kW) test. The X-ray measurement for radiofrequency cavity was designed by means of bremsstrahlung. A suitable shielding cover was chosen for radiofrequency cavity and the X-ray measurement design was demonstrated according to the theory of photon transmission. Finally, the peak voltage of Dee was obtained at the power of 10-20 kW and the balance of Dee voltage was verified
Characterization of Zur-dependent genes and direct Zur targets in Yersinia pestis
<p>Abstract</p> <p>Background</p> <p>The zinc uptake regulator Zur is a Zn<sup>2+</sup>-sensing metalloregulatory protein involved in the maintenance of bacterial zinc homeostasis. Up to now, regulation of zinc homeostasis by Zur is poorly understood in <it>Y. pestis</it>.</p> <p>Results</p> <p>We constructed a <it>zur </it>null mutant of <it>Y. pestis </it>biovar <it>microtus </it>strain 201. Microarray expression analysis disclosed a set of 154 Zur-dependent genes of <it>Y. pestis </it>upon exposure to zinc rich condition. Real-time reverse transcription (RT)-PCR was subsequently used to validate the microarray data. Based on the 154 Zur-dependent genes, predicted regulatory Zur motifs were used to screen for potential direct Zur targets including three putative operons <it>znuA, znuCB </it>and <it>ykgM</it>-<it>RpmJ2</it>. The LacZ reporter fusion analysis verified that Zur greatly repressed the promoter activity of the above three operons. The subsequent electrophoretic mobility shift assay (EMSA) demonstrated that a purified Zur protein was able to bind to the promoter regions of the above three operons. The DNase I footprinting was used to identify the Zur binding sites for the above three operons, verifying the Zur box sequence as predicted previously in γ-Proteobacteria. The primer extension assay was further used to determine the transcription start sites for the above three operons and to localize the -10 and -35 elements. Zur binding sites overlapped the -10 sequence of its target promoters, which was consistent with the previous observation that Zur binding would block the entry of the RNA polymerase to repress the transcription of its target genes.</p> <p>Conclusion</p> <p>Zur as a repressor directly controls the transcription of <it>znuA, znuCB </it>and <it>ykgM</it>-<it>RpmJ2 </it>in <it>Y. pestis </it>by employing a conserved mechanism of Zur-promoter DNA association as observed in γ-Proteobacteria. Zur contributes to zinc homeostasis in <it>Y. pestis </it>likely through transcriptional repression of the high-affinity zinc uptake system ZnuACB and two alternative ribosomal proteins YkgM and RpmJ2.</p
Recommended from our members
Superconducting Zirconium Polyhydrides at Moderate Pressures.
Highly compressed hydrides have been at the forefront of the search for high-Tc superconductivity. The recent discovery of record-high Tc's in H3S and LaH10±x under high pressure fuels the enthusiasm for finding good superconductors in similar hydride groups. Guided by first-principles structure prediction, we successfully synthesized ZrH3 and Zr4H15 at modest pressures (30-50 GPa) in diamond anvil cells by two different reaction routes: ZrH2 + H2 at room temperature and Zr + H2 at ∼1500 K by laser heating. From the synchrotron X-ray diffraction patterns, ZrH3 is found to have a Pm3̅n structure corresponding to the familiar A15 structure, and Zr4H15 has an I4̅3d structure isostructural to Th4H15. Electrical resistance measurement and the dependence of Tc on the applied magnetic field of the sample showed the emergence of two superconducting transitions at 6.4 and 4.0 K at 40 GPa, which correspond to the two Tc's for ZrH3 and Zr4H15.This work was supported by the National Key R&D Program of China (No. 2018YFA0305900), National Natural Science Foundation of China (Nos. 51632002, 11674122, 51572108, and 11504127), Program for Changjiang Scholars and Innovative Research Team in University (No. IRT_15R23), the 111 Project (No. B12011), and the Natural Sciences and Engineering Research Council of Canada (NSERC). C.J.P. acknowledges financial support from the Engineering and Physical Sciences Research Council (Grant EP/P022596/1) and a Royal Society Wolfson Research Merit award
Identification and characterization of PhoP regulon members in Yersinia pestis biovar Microtus
<p>Abstract</p> <p>Background</p> <p>The transcription regulator PhoP has been shown to be important for <it>Y. pestis </it>survival in macrophages and under various <it>in vitro </it>stresses. However, the mechanism by which PhoP promotes bacterial intracellular survival is not fully understood. Our previous microarray analysis suggested that PhoP governed a wide set of cellular pathways in <it>Y. pestis</it>. A series of biochemical experiments were done herein to study members of the PhoP regulon of <it>Y. pestis </it>biovar <it>Microtus</it>.</p> <p>Results</p> <p>By using gel mobility shift assay and quantitative RT-PCR, a total of 30 putative transcription units were characterized as direct PhoP targets. The primer extension assay was further used to determine the transcription start sites of 18 PhoP-dependent promoters and to localize the -10 and -35 elements. The DNase I footprinting was used to identify the PhoP-binding sites within 17 PhoP-dependent promoters, enabling the identification of PhoP box and matrix that both represented the conserved signals for PhoP recognition in <it>Y. pestis</it>. Data presented here providing a good basis for modeling PhoP-promoter DNA interactions that is crucial to the PhoP-mediated transcriptional regulation.</p> <p>Conclusion</p> <p>The proven direct PhoP targets include nine genes encoding regulators and 21 genes or operons with functions of detoxification, protection against DNA damages, resistance to antimicrobial peptides, and adaptation to magnesium limitation. We can presume that PhoP is a global regulator that controls a complex regulatory cascade by a mechanism of not only directly controlling the expression of specific genes, but also indirectly regulating various cellular pathways by acting on a set of dedicated regulators. These results help us gain insights into the PhoP-dependent mechanisms by which <it>Y. pestis </it>survives the antibacterial strategies employed by host macrophages.</p
Formic acid enhances whole-plant mulberry silage fermentation by boosting lactic acid production and inhibiting harmful bacteria
Mulberry has also been regarded as a valuable source of forage for ruminants. This study was developed to investigate the impact of four additives and combinations thereof on fermentation quality and bacterial communities associated with whole-plant mulberry silage. Control fresh material (FM) was left untreated, while other groups were treated with glucose (G, 20 g/kg FM), a mixture of Lactobacillus plantarum and L. buchneri (L, 106 CFU/g FM), formic acid (A, 5 mL/kg FM), salts including sodium benzoate and potassium sorbate (S, 1.5 g/kg FM), a combination of G and L (GL), a combination of G and A (GA), or a combination of G and S (GS), followed by ensiling for 90 days. Dry matter content in the A, S, GA, and GS groups was elevated relative to the other groups (p < 0.01). Relative to the C group, all additives and combinations thereof were associated with reductions in pH and NH3-N content (p < 0.01). The A groups exhibited the lowest pH and NH3-N content at 4.23 and 3.27 g/kg DM, respectively (p < 0.01), whereas the C groups demonstrated the highest values at 4.43 and 4.44 g/kg DM, respectively (p < 0.01). The highest levels of lactic acid were observed in the GA and A groups (70.99 and 69.14 g/kg DM, respectively; p < 0.01), followed by the GL, L, and GS groups (66.88, 64.17 and 63.68 g/kg DM, respectively), with all of these values being higher than those for the C group (53.27 g/kg DM; p < 0.01). Lactobacillus were the predominant bacteria associated with each of these samples, but the overall composition of the bacterial community was significantly impacted by different additives. For example, Lactobacillus levels were higher in the G, A, and GA groups (p < 0.01), while those of Weissella levels were raised in the L, GL, and GS groups (p < 0.01), Pediococcus levels were higher in the A and GA groups (p < 0.01), Enterococcus levels were higher in the G and S groups (p < 0.01), and Lactococcus levels were raised in the S group (p < 0.01). Relative to the C group, a reduction in the levels of undesirable Enterobacter was evident in all groups treated with additives (p < 0.01), with the greatest reductions being evident in the A, S, GA, and GS groups. The additives utilized in this study can thus improve the quality of whole-plant mulberry silage to varying extents through the modification of the associated bacterial community, with A and GA addition achieving the most efficient reductions in pH together with increases in lactic acid content and the suppression of undesirable bacterial growth
Reversal of Cancer Cachexia and Muscle Wasting by ActRIIB Antagonism Leads to Prolonged Survival
SummaryMuscle wasting and cachexia have long been postulated to be key determinants of cancer-related death, but there has been no direct experimental evidence to substantiate this hypothesis. Here, we show that in several cancer cachexia models, pharmacological blockade of ActRIIB pathway not only prevents further muscle wasting but also completely reverses prior loss of skeletal muscle and cancer-induced cardiac atrophy. This treatment dramatically prolongs survival, even of animals in which tumor growth is not inhibited and fat loss and production of proinflammatory cytokines are not reduced. ActRIIB pathway blockade abolished the activation of the ubiquitin-proteasome system and the induction of atrophy-specific ubiquitin ligases in muscles and also markedly stimulated muscle stem cell growth. These findings establish a crucial link between activation of the ActRIIB pathway and the development of cancer cachexia. Thus ActRIIB antagonism is a promising new approach for treating cancer cachexia, whose inhibition per se prolongs survival.PaperCli
- …