The PUF proteins in Trypanosoma brucei

The protozoan parasite Trypanosoma brucei, which causes human sleeping sickness, has to adapt to rather different environments as it cycles between the mammalian host and the tsetse fly vector. This adaptation is mediated by changes in trypanosome gene expression, which are mainly regulated at the post-transcriptional level. Proteins with an RNA-binding "Puf" domain are important for post-transcriptional control by modulation of mRNA stability and regulation of translation in other species. This suggested that Puf domain proteins might also have a similar role in trypanosomes. In addition to the previously characterized TbPUF1 (Hoek, Zanders et al. 2002) I have identified eight more PUF genes in the T. brucei genome. A comparison of the characteristic RNA binding domain of T. brucei PUF proteins suggested that they bind related but distinct targets. Interestingly, each of the PUF protein has an orthologue in Trypanosoma cruzi and Leishmania major. Phylogenetic analysis suggested that there were several kinetoplastid PUF proteins before separation from the eukaryotic lineage. Depletion of each of the nine T. brucei PUF proteins by RNA interference did not result in an obvious phenotypic change. Furthermore, PUF1 knock out procyclic cell lines were viable, indicating that this PUF protein is not essential for in vitro growth. Additionally, double RNAi analyses suggested that the proteins tested did not share redundant functions in T. brucei. Microarray studies comparing wild-type cells with cells where PUF levels have been perturbed (either by RNAi or overexpression) revealed one putative mRNA target for PUF5: CAP17 (corset associated protein 17) mRNA is downregulated upon overexpression of PUF5 in the insect form of the parasite. Interestingly, PUF5 overexpression was also lethal for procyclic cells. Multiple mRNAs which associated with PUF proteins in mRNP complexes were identified. PUF5 for example, selectively binds to mRNAs encoding for amino acid transporters in bloodstream form cells. Attempts to identify PUF interaction partners have so far failed. The effect of PUF proteins on global protein expression level was also investigated using two-dimensional gel electrophoresis approach. A few proteins which were differentially regulated upon RNAi or knockout of PUF proteins were identified. These results indicated that PUF proteins in T. brucei, as is true for PUF proteins in general, are involved in regulating gene expression

ViHOS: Hate Speech Spans Detection for Vietnamese

The rise in hateful and offensive language directed at other users is one of the adverse side effects of the increased use of social networking platforms. This could make it difficult for human moderators to review tagged comments filtered by classification systems. To help address this issue, we present the ViHOS (Vietnamese Hate and Offensive Spans) dataset, the first human-annotated corpus containing 26k spans on 11k comments. We also provide definitions of hateful and offensive spans in Vietnamese comments as well as detailed annotation guidelines. Besides, we conduct experiments with various state-of-the-art models. Specifically, XLM-R$_{Large}$ achieved the best F1-scores in Single span detection and All spans detection, while PhoBERT$_{Large}$ obtained the highest in Multiple spans detection. Finally, our error analysis demonstrates the difficulties in detecting specific types of spans in our data for future research. Disclaimer: This paper contains real comments that could be considered profane, offensive, or abusive.Comment: EACL 202

USING A MULTI-CRITERIA DECISION-MAKING MODEL TO EVALUATE AND SELECT AN E-COMMERCE PLATFORM

The COVID-19 pandemic has led to disruptions in consumers' lifestyles and purchases, as well as businesses' online business models. Online platforms are increasingly used for shopping purposes. To evaluate and choose an e-commerce platform requires using many criteria and decision makers. Therefore, the process of evaluating and selecting an e-commerce platform is viewed as a multi-criteria decision-making problem. The objective of this study is to develop a multi-criteria decision-making model to help consumers evaluating the e-commerce platforms. In the proposed model, the ratings of alternatives and the weights of the criteria are evaluated using the linguistic variable. Simulation examples are used to show the effectiveness of the model in practice.  Keywords: Fuzzy TOPSIS, E-Commerce Platform, Mcdm, Fuzzy Sets