Novelty Detection by Latent Semantic Indexing

As a new topic in text mining, novelty detection is a natural extension of information retrieval systems, or search engines. Aiming at refining raw search results by filtering out old news and saving only the novel messages, it saves modern people from the nightmare of information overload. One of the difficulties in novelty detection is the inherent ambiguity of language, which is the carrier of information. Among the sources of ambiguity, synonymy proves to be a notable factor. To address this issue, previous studies mainly employed WordNet, a lexical database which can be perceived as a thesaurus. Rather than borrowing a dictionary, we proposed a statistical approach employing Latent Semantic Indexing (LSI) to learn semantic relationship automatically with the help of language resources. To apply LSI which involves matrix factorization, an immediate problem is that the dataset in novelty detection is dynamic and changing constantly. As an imitation of real-world scenario, texts are ranked in chronological order and examined one by one. Each text is only compared with those having appeared earlier, while later ones remain unknown. As a result, the data matrix starts as a one-row vector representing the first report, and has a new row added at the bottom every time we read a new document. Such a changing dataset makes it hard to employ matrix methods directly. Although LSI has long been acknowledged as an effective text mining method when considering semantic structure, it has never been used in novelty detection, nor have other statistical treatments. We tried to change this situation by introducing external text source to build the latent semantic space, onto which the incoming news vectors were projected. We used the Reuters-21578 dataset and the TREC data as sources of latent semantic information. Topics were divided into years and types in order to take the differences between them into account. Results showed that LSI, though very effective in traditional information retrieval tasks, had only a slight improvement to the performances for some data types. The extent of improvement depended on the similarity between news data and external information. A probing into the co-occurrence matrix attributed such a limited performance to the unique features of microblogs. Their short sentence lengths and restricted dictionary made it very hard to recover and exploit latent semantic information via traditional data structure

A Case Study of IELTS in Mainland China

This essay is a case study of IELTS use in mainland China, discussing the language assessment from three aspects: the purposes for testing, ethical problems of IELTS, and technologies applied in IELTS. It is worth noting that there are two types of IELTS: academic IELTS and general training IELTS, offered jointly by the British Council, Cambridge English Language Assessment, and other committees. This essay is confined to academic IELTS

System Structure Risk Metric Method Based on Information Flow

Part 5: Modelling and SimulationInternational audienceThe measurement of structure risk aims to analysis and evaluate the not occurred, potential, and the objectively exist risk in system structure. It is an essential way to validate system function and system quality. This paper proposes the risk metric model and algorithm based on information flow and analysis risk trend between traditional tree structure and network-centric structure

The Expressions of IL-7 and IL-7R and the Relationship between them with Lymph Node Metastasis and Prognosis in Non-small Cell Lung Cancer

Background and objective It has been proven that lymph node metastasis was closely related to prognosis of lung cancer. Interleukin-7 (IL-7) and interleukin-7 receptor (IL-7R) could promote lymph node metastasis through vascular endothelial growth factor-D (VEGF-D). The aim of this study is to explore the expressions of IL-7 and IL-7R in lung cancer and the relationship between them with lymph node metastasis and prognosis in non-small cell lung cancer (NSCLC). Methods The expressions of IL-7 and IL-7R in 95 cases of NSCLC were detected with immunohistochemistry method and the relationship between IL-7 and IL-7R and their impact on lung cancer patients’ outcomes were analyzed. Results In 95 cases of NSCLC, the high expression rates of IL-7, IL-7R and VEGF-D were 63.16%, 61.05% and 58.95%. The expressions of IL-7 and IL-7R were correlated closely with clinic stage and lymph node metastasis, but had no relationship with age, gender, histological type and differentiation degree. The lymphatic vessel density (LVD) mean of the group with high expressions of IL-7 and IL-7R was higher than that with low or negative expressions of IL-7 and IL-7R, and they were significant different in statistics. Log-rank analysis showed that the postoperative survival period was significantly shorter in high expression groups IL-7, IL-7R and VEGF-D comparing with that in low or negative groups. Conclusion The high expression of IL-7 and IL-7R is highly positie correlated with clinic stage, lymph node metastasis, VEGF-D, LVD and poor prognosis in Non-small cell lung cancer

hsa-miR-125a-5p Enhances Invasion Ability in Non-Small Lung Carcinoma Cell Lines

Background and objective MicroRNAs (miRNAs) are short non-coding RNAs that posttranscriptionally regulate gene expression by partially binding complementary to target sites in mRNAs. Although some impaired miRNA regulations have been observed in many human cancers, the functions of miR-125a are still unclear. The aim of this study is to investigate the expression of hsa-miR-125a-5p in NSCLC cell lines and the relationship between hsa-miR-125a-5p and the invasion of lung cancer cells. Methods The expression of hsa-miR-125a-5p and the effectiveness for a given period time after being transfected sense hsa-miR-125a-5p 2’-O-methyl oligonucleotide, which were 24 h, 36 h, 48 h, 60 h and 72 h, were examined by realtime PCR. Meanwhile, we investigated the modification of invasive ability in A549 and NCI-H460 cells by transwell. Results Real-time PCR showed that hsa-miR-125a-5p was poorly-expressed in 6 lung cancer cell lines, especially in LH7, NCI-H460, SPC-A-1 and A549. The highest expression of hsa-miR-125a-5p occurred in the cells transfected with sense hsa-miR-125a-5p 2’-O-methyl oligonucleotide 36 h. Furthermore, the invasive abilities of A549 and NCI-H46O were enhanced by up-regulating hsa-miR-125a-5p. Conclusion hsa-miR-125a-5p was poorly-expressed in lung cancer cells and it could enhance lung cancer cell invasion by up-regulating hsa-miR-125a-5p

Treatment-emergent neuroendocrine prostate cancer: A clinicopathological and immunohistochemical analysis of 94 cases

Purpose: This study aimed to evaluate the pathological characteristics, immunophenotype, and prognosis of treatment-emergent neuroendocrine prostate cancer (T-NEPC). Materials and Methods: We collected 231 repeated biopsy specimens of castration-resistant prostate cancer (CRPC) cases between 2008 and 2019. We used histopathological and immunohistochemical evaluations of Synaptophysin (SYN), ChromograninA (CgA), CD56, androgen receptor (AR), and prostate Results: Among the 231 CRPC cases, 94 (40.7%) cases were T-NEPC. T-NEPC were more likely to present with negative immunohistochemistry for AR (30.9%) and PSA (47.9%) than that of CRPC (8.8% and 17.5%, respectively). Kaplan-Meier analysis revealed that patients with T-NEPC (median overall survival [OS]: 17.6 months, 95% CI: 15.3-19.9 months) had significantly worse survival compared with usual CRPC patients (median OS: 23.6 months, 95% CI: 21.3-25.9 months, log-rank Conclusion: T-NEPC was associated with an unfavorable prognosis, negative immunohistochemistry for PSA in T-NEPC and serum PSA level ≤ 4 ng/ml had a worse prognosis. Urologists and pathologists should recognize the importance of the second biopsy in CRPC to avoid unnecessary diagnosis and treatment delays