Pre-training Multi-party Dialogue Models with Latent Discourse Inference

Multi-party dialogues are more difficult for models to understand than one-to-one two-party dialogues, since they involve multiple interlocutors, resulting in interweaving reply-to relations and information flows. To step over these obstacles, an effective way is to pre-train a model that understands the discourse structure of multi-party dialogues, namely, to whom each utterance is replying. However, due to the lack of explicitly annotated discourse labels in multi-party dialogue corpora, previous works fail to scale up the pre-training process by putting aside the unlabeled multi-party conversational data for nothing. To fully utilize the unlabeled data, we propose to treat the discourse structures as latent variables, then jointly infer them and pre-train the discourse-aware model by unsupervised latent variable inference methods. Experiments on multiple downstream tasks show that our pre-trained model outperforms strong baselines by large margins and achieves state-of-the-art (SOTA) results, justifying the effectiveness of our method. The official implementation of this paper is available at https://github.com/EricLee8/MPD_EMVI.Comment: Accepted by ACL 202

Effects of flavonoids derived from Taxus yunnanensis on p-glycoprotein and cytochrome P450 3A4

AbstractThe intestinal uptake of paclitaxel is hampered by trans-membrane efflux transporters such as P-glycoprotein (P-gp), and paclitaxel is mainly metabolized by cytochrome P450 3A4 (CYP3A4) presented in the liver. Our previous results demonstrated that flavonoids extracted from Taxus yunnanensis could improve the oral absorption of paclitaxel. The current study was purposed to investigate the effects of the flavonoid extracts on P-gp and CYP3A4 in vitro. The expression and activity of P-gp were detected by western blotting and intracellular rhodamine 123 accumulation assay in Caco-2 cells treated with the flavonoids extract. The expression of CYP3A4 was investigated by western blotting in mouse primary hepatocytes and the activity of CYP3A4 was detected by LC-MS/MS method using rat liver microsomes. Our results showed that the flavonoid extracts from T. yunnanensis could inhibit P-gp activity and concurrently decrease the expression and activity of CYP3A4. In conclusion, activity of P-gp and CYP3A4 could be inhibited by flavonoids extracted from T. yunnanensis which might be potential candidates for development of oral formulation of paclitaxel

Evaluation of the Persistence of Higher-Order Strand Symmetry in Genomic Sequences by Novel Word Symmetry Distance Analysis

For the ubiquitous phenomenon of strand symmetry, it has been shown that it may persist for higher-order oligonucleotides. However, there is no consensus about to what extent (order of oligonucleotides or length of words) strand symmetry still persists. To determine the extent of strand symmetry in genomic sequences is critically important for the further understanding of the phenomenon. Based on previous studies, we have developed an algorithm for the novel word symmetry distance analysis. We applied it to evaluate the higher-order strand symmetry for 206 archaeal genomes and 2,659 bacterial genomes. Our results show that the new approach could provide a clear-cut criterion to determine the extent of strand symmetry for a group of genomes or individual genomes. According to the new measure, strand symmetry would tend to persist for up to 8-mers in archaeal genomes, and up to 9-mers in bacterial genomes. And the persistence may vary from 6- to 9-mers in individual genomes. Moreover, higher-order strand symmetry would tend to positively correlate with GC content and mononucleotide symmetry levels of genomic sequences. The variations of higher-order strand symmetry among genomes would indicate that strand symmetry itself may not be strictly relevant to biological functions, which would provide some insights into the origin and evolution of the phenomenon

Nondestructive Evaluation of Inoculation Effects of AMF and <em>Bradyrhizobium japonicum</em> on Soybean under Drought Stress From Reflectance Spectroscopy

Precise estimation of leaf chlorophyll content (LCC) and leaf water content (LWC) of soybean, using remote sensing technology, provides a new avenue for the nondestructive evaluation of inoculation effects of arbuscular mycorrhizal fungi (AMF) and Bradyrhizobium japonicum (BJ) on soybean growth condition. In this study, a series of pot experiments were conducted in the greenhouse, soybean inoculated with Glomus intraradices (G.i, one of AMF species), G.i and BJ, and non-inoculation were planted under drought stress (DS) and normal irrigation (NI) conditions. Leaf spectra and LCC and LWC were measured on the 28th and 56th days after inoculation. Two new simple ratio (SR) indices, derived from the first derivative spectral reflectance at λ1 nm (Dλ1) and the raw spectral reflectance at λ2 nm (Rλ2), were developed to estimate LCC and LWC. The results indicate that under DS, plants inoculated with G.i had higher LCC and LWC than the non-inoculated plants, followed by the counterparts co-inoculated with G.i and BJ. Linear estimation models, established by the D650/Rred edge and D1680/R680, achieved great improved accuracy for quantifying LCC and LWC of soybean under inoculation and drought stress treatments, with determination of coefficient of 0.63 and 0.76, respectively

Dry sliding wear behavior of an extruded Mg–Dy–Zn alloy with long period stacking ordered phase

AbstractThe dry sliding wear behavior of extruded Mg-2Dy-0.5Zn alloy (at.%) was investigated using a pin-on-disk configuration. The friction coefficient and wear rate were measured within a load range 20–760 N at a sliding velocity of 0.785 m/s. Microstructure and wear surface of alloy were examined using scanning electron microscopy. The mechanical properties of alloy were tested at room and elevated temperatures. Five wear mechanisms, namely abrasion, oxidation, delamination, thermal softening and melting dominated the whole wear behavior with increasing applied load. The extruded Mg-2Dy-0.5Zn alloy exhibited the better wear resistance as compared with as-cast Mg97Zn1Y2 alloy under the given conditions through contact surface temperature analysis. The improved wear resistance was mainly related to fine grain size, good thermal stability of long period stacking order (LPSO) phase and excellent higher-temperature mechanical properties