A Hierarchical Attention-based Contrastive Learning Method for Micro Video Popularity Prediction

Micro videos popularity prediction (MVPP) has recently attracted widespread research interests given the increasing prevalence of video-based social platforms. However, previous studies have overlooked the unique patterns between popular and unpopular videos and the interactions between asynchronous features different data dimensions. To address this, we propose a novel hierarchical attention contrastive learning method named HACL, which extracts explainable representation features, learns their asynchronous interactions from both temporal and spatial levels, and separates the positive and negative embeddings identities. This reveals video popularity in a contrastive and interrelated view, and thus can be responsible for a better MVPP. Dual neural networks account for separate positive and negative patterns via contrastive learning. To obtain the temporal-wise interaction coefficients, we propose a Hadamard-product based attention approach to optimize the trainable attention-map matrices. Results from our experiments on a TikTok micro video dataset show that HACL outperforms benchmarks and provides insightful managerial implications

SKIL/SnoN attenuates TGF-β1/SMAD signaling-dependent collagen synthesis in hepatic fibrosis

The ski-related novel gene (SnoN), encoded by the SKIL gene, has been shown to negatively regulated transforming growth factor-β1 (TGF-β1) signaling pathway. However, the roles of SnoN in hepatic stellate cell (HSC) activation and hepatic fibrosis (HF) are still unclear. To evaluate the role of SnoN in HF, we combined bulk RNA sequencing analysis and single-cell RNA sequencing analysis to analyse patients with HF. The role of SKIL/SnoN was verified using liver samples from rat model transfected HSC-T6 and LX-2 cell lines. Immunohistochemistry, immunofluorescence, PCR, and western blotting techniques were used to demonstrate the expression of SnoN and its regulatory effects on TGF-β1 signaling in fibrotic liver tissues and cells. Furthermore, we constructed competitive endogenous RNA regulatory network and potential drug network associated with the SnoN gene. We identified SKIL gene as a differentially expressed gene in hepatic fibrosis. SnoN protein was found to be widely expressed in the cytoplasm of normal hepatic tissues, whereas it was almost absent in HF tissues. In the rat group subjected to bile duct ligation (BDL), SnoN protein expression decreased, while TGF-β1, collagen III, tissue inhibitor of metalloproteinase 1 (TIMP-1), and fibronectin levels increased. We observed the interaction of SnoN with p-SMAD2 and p-SMAD3 in the cytoplasm. Following SnoN overexpression, apoptosis of HSCs was promoted, and the expression of HF-associated proteins, including collagen I, collagen III, and TIMP-1, was reduced. Conversely, downregulation of SnoN inhibited HSC apoptosis, increased collagen III and TIMP-1 levels, and decreased matrix metalloproteinase 13 (MMP-13) expression. In conclusion, SnoN expression is downregulated in fibrotic livers, and could attenuate TGF-β1/SMADs signaling-dependent de-repression of collagen synthesis

Effect of symbiotic fungi-Armillaria gallica on the yield of Gastrodia elata Bl. and insight into the response of soil microbial community

Armillaria members play important roles in the nutrient supply and growth modulation of Gastrodia elata Bl., and they will undergo severe competition with native soil organisms before colonization and become symbiotic with G. elata. Unraveling the response of soil microbial organisms to symbiotic fungi will open up new avenues to illustrate the biological mechanisms driving G. elata’s benefit from Armillaria. For this purpose, Armillaria strains from four main G. elata production areas in China were collected, identified, and co-planted with G. elata in Guizhou Province. The result of the phylogenetic tree indicated that the four Armillaria strains shared the shortest clade with Armillaria gallica. The yields of G. elata were compared to uncover the potential role of these A. gallica strains. Soil microbial DNA was extracted and sequenced using Illumina sequencing of 16S and ITS rRNA gene amplicons to decipher the changes of soil bacterial and fungal communities arising from A. gallica strains. The yield of G. elata symbiosis with the YN strain (A. gallica collected from Yunnan) was four times higher than that of the GZ strain (A. gallica collected from Guizhou) and nearly two times higher than that of the AH and SX strains (A. gallica collected from Shanxi and Anhui). We found that the GZ strain induced changes in the bacterial community, while the YN strain mainly caused changes in the fungal community. Similar patterns were identified in non-metric multidimensional scaling analysis, in which the GZ strain greatly separated from others in bacterial structure, while the YN strain caused significant separation from other strains in fungal structure. This current study revealed the assembly and response of the soil microbial community to A. gallica strains and suggested that exotic strains of A. gallica might be helpful in improving the yield of G. elata by inducing changes in the soil fungal community

Complementary or Substitutive? Leveraging Text-image Interactions for Review Helpfulness Prediction

Extensive research have shown the significant influence of textual contents on review helpfulness prediction, however, the review images draw little attention. Actually, the information conveyed in the review images can be either additional information (complementation effect) or similar information (substitution effect) in contrast with the textual review information. We propose a novel multimodal deep learning method to better leverage the online review texts and images and capture such interaction effect between them for their helpfulness prediction. The method firstly extracts the multimodal features using the pre-trained deep learning models and then feeds into the LSTM and attention units to learn the sequential dependency relation and importance weights. We formulize the complementation-substitution based text-image interaction effects into the loss function. Empirical experiment results on a large-scale online review dataset show the superiority of our method in terms of both prediction performance and representation learning performance

Being Sagacious towards Proliferated Post-Purchase Sharing: A Novel Disclosure Pattern-Wise Helpful Online Reviews Extraction Method

The proliferation of social media platforms flourishes research on helpful online reviews. Prior studies have ubiquitously taken subjective indicators to measure online review helpfulness, such as the voted reviews and reviews with an emotional tendency. By highlighting helpful reviews, researchers strive to extricate consumers from the explosive growth amount of post-purchase information. In this study, we theoretically reformulate the consumer-oriented online review helpfulness as three indicators, including effectiveness (i.e., product-specific), representativeness or objectivity (i.e., identical distribution with original review set), and semantic diversity (for personalized information demand). Moreover, we design a novel disclosure pattern-wise method to coordinate the three indicators for enhancing helpful review extraction. Experiments on more than 2 million of hotel reviews manifest the superiority of our proposed method for balancing the trade-off among different review helpfulness indicators, in contrast to conventional helpful review extraction methods

Comparison of single-stage and two-phase anaerobic sludge digestion systems : performance and microbial community dynamics

This study compared reactor performance and the respective microbial community dynamics in the conventional single-stage and 2-phase anaerobic digestion (AD) systems, treating municipal sludge to generate methane. The 2-phase system’s COD and VS reduction, and methane production could be maintained throughout the three HRTs tested (p = 0.05), which was associated with an increase in organic loading (30 d = 1.5 g COD L−1 d−1, 20 d = 2.2 g COD L−1 d−1 and 10 d = 3.5 g COD L−1 d−1); but this was not so in the single-stage system where it deteriorated at HRT of 10 d (p = 0.05) due to impairment of particulate COD reduction. qPCR, DGGE and the subsequent phylogenetic analysis revealed that microbial adaptation occurred as the seed sludge formed a different community in each reactor at 30 d HRT; however, no further significant microbial shift occurred at lower HRTs. The presence of specific hydrolytic and acidogenic Flavobacteriales and Clostriales in the acidogenic reactor may have allowed for enhanced hydrolysis and acidogenesis, leading to higher organic loading tolerance at 10 d HRT. Methanogenic activity in the acidogenic reactor may have been performed by Methanobacteriales and Methanosarcinaceae. Operation of the acidogenic reactor at neutral pH may have to be considered to ensure the cultivation of propionate oxidising bacteria, which could in turn, prevent reactor “souring” during high load conditions.NRF (Natl Research Foundation, S’pore)Accepted versio

Determination of the archaeal and bacterial communities in two-phase and single-stage anaerobic systems by 454 pyrosequencing

2-Phase anaerobic digestion (AD), where the acidogenic phase was operated at 2 day hydraulic retention time (HRT) and the methanogenic phase at 10 days HRT, had been evaluated to determine if it could provide higher organic reduction and methane production than the conventional single-stage AD (also operated at 12 days HRT). 454 pyrosequencing was performed to determine and compare the microbial communities. The acidogenic reactor of the 2-phase system yielded a unique bacterial community of the lowest richness and diversity, while bacterial profiles of the methanogenic reactor closely followed the single-stage reactor. All reactors were predominated by hydrogenotrophic methanogens, mainly Methanolinea. Unusually, the acidogenic reactor contributed up to 24% of total methane production in the 2-phase system. This could be explained by the presence of Methanosarcina and Methanobrevibacter, and their activities could also help regulate reactor alkalinity during high loading conditions through carbon dioxide production. The enrichment of hydrolytic and acidogenic Porphyromonadaceae, Prevotellaceae, Ruminococcaceae and unclassified Bacteroidetes in the acidogenic reactor would have contributed to the improved sludge volatile solids degradation, and ultimately the overall 2-phase system's performance. Syntrophic acetogenic microorganisms were absent in the acidogenic reactor but present in the downstream methanogenic reactor, indicating the retention of various metabolic pathways also found in a single-stage system. The determination of key microorganisms further expands our understanding of the complex biological functions in AD process.NRF (Natl Research Foundation, S’pore)Published versio

Effect of sodium on methanogens in a two-stage anaerobic system

This study evaluated the effects of sodium on anaerobic biomass from the second-stage reactor of a two-stage anaerobic digester. The results indicated that methanogens showed a rela-tively high sodium tolerance of 2.4 g Na+ L−1 . Microbial community analysis showed that viable Methanomicrobiales was the most abundant population by a combined propidium monoazide cross-linking quantitative polymerase chain reaction technique. There was a population shift towards higher abundance of Thermotoga (0.02%), Clostridium (2.50%) and Methanoculleus (13.80%). Biomass activity in relation to increased sodium concentrations was investigated with the adenosine triphos-phate test coupled with extracellular polymeric substances measurement. The results showed biomass activity decreased from 33 to 16 µg g−1 volatile suspended solids as sodium concentrations increased from 1.3 to 9.1 g Na+ L−1 . Higher EPS production, particularly a greater predominance of carbo-hydrates, was stimulated by higher sodium concentrations. This study provides insights into the superiority of sodium tolerance of two-stage anaerobic digester in compared with a single-stage anaerobic system.National Research Foundation (NRF)Published versionThe authors would like to thank the National Natural Science Foundation of China (No. 52170133). The authors would also like to thank the Singapore National Research Foundation for providing funding for the project “Wastewater Treatment Plants as Urban Eco Power Stations”

Effect of Sodium on Methanogens in a Two-Stage Anaerobic System

This study evaluated the effects of sodium on anaerobic biomass from the second-stage reactor of a two-stage anaerobic digester. The results indicated that methanogens showed a relatively high sodium tolerance of 2.4 g Na+ L−1. Microbial community analysis showed that viable Methanomicrobiales was the most abundant population by a combined propidium monoazide cross-linking quantitative polymerase chain reaction technique. There was a population shift towards higher abundance of Thermotoga (0.02%), Clostridium (2.50%) and Methanoculleus (13.80%). Biomass activity in relation to increased sodium concentrations was investigated with the adenosine triphosphate test coupled with extracellular polymeric substances measurement. The results showed biomass activity decreased from 33 to 16 µg g−1 volatile suspended solids as sodium concentrations increased from 1.3 to 9.1 g Na+ L−1. Higher EPS production, particularly a greater predominance of carbohydrates, was stimulated by higher sodium concentrations. This study provides insights into the superiority of sodium tolerance of two-stage anaerobic digester in compared with a single-stage anaerobic system

Impact of undissociated volatile fatty acids on acidogenesis in a two-phase anaerobic system

This study investigated the degradation and production of volatile fatty acids (VFAs) in the acidogenic phase reactor of a two-phase anaerobic system. 20 mmol/L bromoethanesulfonic acid (BESA) was used to inhibit acidogenic methanogens (which were present in the acidogenic phase reactor) from degrading VFAs. The impact of undissociated volatile fatty acids (unVFAs) on “net” VFAs production in the acidogenic phase reactor was then evaluated, with the exclusion of concurrent VFAs degradation. “Net” VFAs production from glucose degradation was partially inhibited at high unVFAs concentrations, with 59%, 37% and 60% reduction in production rates at 2190 mg chemical oxygen demand (COD)/L undissociated acetic acid (unHAc), 2130 mg COD/L undissociated propionic acid (unHPr) and 2280 mg COD/L undissociated n-butyric acid (unHBu), respectively. The profile of VFAs produced further indicated that while an unVFA can primarily affect its own formation, there were also unVFAs that affected the formation of other VFAs.NRF (Natl Research Foundation, S’pore