Drug discovery is a time-consuming, high-investment, and high-risk process in traditional drug development. Drug repositioning has become a popular strategy in recent years. Different from traditional drug development strategies, the strategy is efficient, economical and riskless. There are usually three kinds of approaches: computational approaches, biological experimental approaches, and mixed approaches, all of which are widely used in drug repositioning. In this paper, we reviewed computational approaches and highlighted their characteristics to provide references for researchers to develop more powerful approaches. At the same time, the important findings obtained using these approaches are listed. Furthermore, we summarized 76 important resources about drug repositioning. Finally, challenges and opportunities in drug repositioning are discussed from multiple perspectives, including technology, commercial models, patents and investment.

/pdf/review-of-drug-repositioning-approaches-and-resources-1riygx6bjm.pdf

Review of Drug Repositioning Approaches and Resources.

This paper presents TIPSem, a system to extract temporal information from natural language texts for English and Spanish. TIPSem, learns CRF models from training data. Although the used features include different language analysis levels, the approach is focused on semantic information. For Spanish, TIPSem achieved the best F1 score in all the tasks. For English, it obtained the best F1 in tasks B (events) and D (event-dct links); and was among the best systems in the rest.

TIPSem (English and Spanish): Evaluating CRFs and Semantic Roles in TempEval-2

Sentiment analysis is one of the recent, highly dynamic fields in Natural Language Processing. Most existing approaches are based on word-level analysis of texts and are mostly able to detect only explicit expressions of sentiment. However, in many cases, emotions are not expressed by using words with an affective meaning (e.g. happy), but by describing real-life situations, which readers (based on their commonsense knowledge) detect as being related to a specific emotion. Given the challenges of detecting emotions from contexts in which no lexical clue is present, in this article we present a comparative analysis between the performance of well-established methods for emotion detection (supervised and lexical knowledge-based) and a method we propose and extend, which is based on commonsense knowledge stored in the EmotiNet knowledge base. Our extensive evaluations show that, in the context of this task, the approach based on EmotiNet is the most appropriate.

Detecting implicit expressions of emotion in text: A comparative analysis

The task of automatically detecting emotion in text is challenging. This is due to the fact that most of the times, textual expressions of affect are not direct-using emotion words-but result from the interpretation and assessment of the meaning of the concepts and interaction of concepts described in the text. This paper presents the core of EmotiNet, a new knowledge base (KB) for representing and storing affective reaction to real-life contexts, and the methodology employed in designing, populating, and evaluating it. The basis of the design process is given by a set of self-reported affective situations in the International Survey on Emotion Antecedents and Reactions (ISEAR) corpus. We cluster the examples and extract triples using Semantic Roles. We subsequently extend our model using other resources, such as VerbOcean, ConceptNet, and SentiWordNet, with the aim of generalizing the knowledge contained. Finally, we evaluate the approach using the representations of other examples in the ISEAR corpus. We conclude that EmotiNet, although limited by the domain and small quantity of knowledge it presently contains, represents a semantic resource appropriate for capturing and storing the structure and the semantics of real events and predicting the emotional responses triggered by chains of actions.

Building and Exploiting EmotiNet, a Knowledge Base for Emotion Detection Based on the Appraisal Theory Model

Question Answering (QA) is a specific type of information retrieval. Given a set of documents, a Question Answering system attempts to find out the correct answer to the question pose in natural language. Question answering is multidisciplinary. It involves information technology, artificial intelligence, natural language processing, knowledge and database management and cognitive science. From the technological perspective, question answering uses natural or statistical language processing, information retrieval, and knowledge representation and reasoning as potential building blocks. It involves text classification, information extraction and summarization technologies. In general, question answering system (QAS) has three components such as question classification, information retrieval, and answer extraction. These components play a essential role in QAS. Question classification play primary role in QA system to categorize the question based upon on the type of its entity. Information retrieval method is get of identify success by extracting out applicable answer post by their intelligent question answering system. Finally, answer extraction module is rising topics in the QAS where these systems are often requiring ranking and validating a candidate’s answer. Most of the Question Answering systems consists of three main modules: question processing, document processing and answer processing. Question processing module plays an important part in QA systems. If this module doesn't work correctly, it will make problems for other sections. Moreover answer processing module is an emerging topic in Question Answering, in which these systems are often required to rank and validate candidate answers. These techniques aiming at discovering the short and precise answers are often based on the semantic classification. QA systems give the ability to answer questions posed in natural language by extracting, from a repository of documents, fragments of documents that contain material relevant to the answer.

/pdf/a-survey-of-text-question-answering-techniques-dgip1jv6u7.pdf

A Survey of Text Question Answering Techniques

Post-truth is a term that describes a distorting phenomenon that aims to manipulate public opinion and behavior. One of its key engines is the spread of Fake News. Nowadays most news is rapidly disseminated in written language via digital media and social networks. Therefore, to detect fake news it is becoming increasingly necessary to apply Artificial Intelligence (AI) and, more specifically Natural Language Processing (NLP). This paper presents a review of the application of AI to the complex task of automatically detecting fake news. The review begins with a definition and classification of fake news. Considering the complexity of the fake news detection task, a divide-and-conquer methodology was applied to identify a series of subtasks to tackle the problem from a computational perspective. As a result, the following subtasks were identified: deception detection; stance detection; controversy and polarization; automated fact checking; clickbait detection; and, credibility scores. From each subtask, a PRISMA compliant systematic review of the main studies was undertaken, searching Google Scholar. The various approaches and technologies are surveyed, as well as the resources and competitions that have been involved in resolving the different subtasks. The review concludes with a roadmap for addressing the future challenges that have emerged from the analysis of the state of the art, providing a rich source of potential work for the research community going forward.

Fighting post-truth using natural language processing: A review and open challenges

This paper presents two proposals based on semantic information, semantic roles and WordNet, for the answer extraction module of a general open-domain question answering (QA) system. The main objective of this research is to determine how the system performance is influenced by using this kind of information, and compare it with that of current QA systems based on named entities (NEs). NE-based QA systems achieve good results with NE-based questions. However, with common noun (CN) based questions, like ''Where is the stomach? In the abdomen'', they fail, and this is the main reason for our study. In this paper our new proposals for answering different types of questions are evaluated and compared with an NE-based approach for both NE-based and CN-based questions. From the results obtained it may be concluded that, with the aid of our proposals, the QA system performs much better with CN-based questions when semantic information is used (semantic information F"@b"="1=74.73% vs. NEF"@b"="1=12.19%). Moreover, the more semantic information the system uses, the better the precision and correctness of the answer it achieves.

Combining semantic information in question answering systems

In this paper, a method to determine the semantic role for the constituents of a sentence is presented. This method, named SemRol, is a corpus-based approach that uses two different statistical models, conditional Maximum Entropy (ME) Probability Models and the TiMBL program, a Memory-based Learning. It consists of three phases that make use of features using words, lemmas, PoS tags and shallow parsing information. Our method introduces a new phase in the Semantic Role Labeling task which has usually been approached as a two phase procedure consisting of recognition and labeling arguments. From our point of view, firstly the sense of the verbs in the sentences must be disambiguated. That is why depending on the sense of the verb a different set of roles must be considered. Regarding the labeling arguments phase, a tuning procedure is presented. As a result of this procedure one of the best sets of features for the labeling arguments task is detected. With this set, that is different for TiMBL and ME, precisions of 76.71% for TiMBL or 70.55% for ME, are obtained. Furthermore, the semantic role information provided by our SemRol method could be used as an extension of Information Retrieval or Question Answering systems. We propose using this semantic information as an extension of an Information Retrieval system in order to reduce the number of documents or passages retrieved by the system.

Corpus-based semantic role approach in information retrieval

https://rua.ua.es/dspace/bitstream/10045/67734/2/2017_Moreno_etal_JBiomedInf_accepted.pdf

DrugSemantics: A corpus for Named Entity Recognition in Spanish Summaries of Product Characteristics.

Actualmente las redes sociales representan un
mecanismo para que un conjunto de personas
puedan potenciar su comunicacion, cooperar entre
ellas en tareas comunes y sentirse parte de una
comunidad. Estas caracteristicas hacen pensar que
su uso seria conveniente en entornos educativos
con el fin de potenciar diversos aspectos como:
participacion del alumnado en el proceso de
aprendizaje, aprendizaje autonomo, interaccion y
motivacion de los alumnos, creatividad del
estudiante y la creacion de redes de colaboracion e
intercambio con continuidad espacio-temporal.
Sin embargo, el uso de redes sociales en la
docencia universitaria, plantea diversas
cuestiones: ?favorece el uso de las redes sociales
el trabajo colaborativo?, ?interactuan los
estudiantes para mejorar el aprendizaje?, ?es un
mecanismo apropiado para mejorar la
comunicacion?, ?se desarrollan nuevos roles del
profesor o estudiante?. En este articulo se
pretenden resolver estas cuestiones y estudiar el
impacto de las redes sociales, en concreto
Facebook, en la ensenanza universitaria

/pdf/la-influencia-de-las-redes-sociales-en-el-aprendizaje-1ivcnlpxuv.pdf

Paloma Moreda

Papers

Fighting post-truth using natural language processing: A review and open challenges

Combining semantic information in question answering systems

Corpus-based semantic role approach in information retrieval

DrugSemantics: A corpus for Named Entity Recognition in Spanish Summaries of Product Characteristics.

La Influencia de las redes sociales en el aprendizaje colaborativo