Evaluating anaphora and coreference resolution to improve automatic keyphrase extraction

In this paper we analyze the effectiveness of using linguistic knowledge from coreference and anaphora resolution for improving the performance for supervised keyphrase extraction. In order to verify the impact of these features, we de\ufb01ne a baseline keyphrase extraction system and evaluate its performance on a standard dataset using different machine learning algorithms. Then, we consider new sets of features by adding combinations of the linguistic features we propose and we evaluate the new performance of the system. We also use anaphora and coreference resolution to transform the documents, trying to simulate the cohesion process performed by the human mind. We found that our approach has a slightly positive impact on the performance of automatic keyphrase extraction, in particular when considering the ranking of the results

Entity recognition in the biomedical domain using a hybrid approach.

BACKGROUND: This article describes a high-recall, high-precision approach for the extraction of biomedical entities from scientific articles. METHOD: The approach uses a two-stage pipeline, combining a dictionary-based entity recognizer with a machine-learning classifier. First, the OGER entity recognizer, which has a bias towards high recall, annotates the terms that appear in selected domain ontologies. Subsequently, the Distiller framework uses this information as a feature for a machine learning algorithm to select the relevant entities only. For this step, we compare two different supervised machine-learning algorithms: Conditional Random Fields and Neural Networks. RESULTS: In an in-domain evaluation using the CRAFT corpus, we test the performance of the combined systems when recognizing chemicals, cell types, cellular components, biological processes, molecular functions, organisms, proteins, and biological sequences. Our best system combines dictionary-based candidate generation with Neural-Network-based filtering. It achieves an overall precision of 86% at a recall of 60% on the named entity recognition task, and a precision of 51% at a recall of 49% on the concept recognition task. CONCLUSION: These results are to our knowledge the best reported so far in this particular task

Influence of monoterpenes in biological activities of Nectandra megapotamica (Spreng.) mez essential oils

Investigating the influence of seasonal variations on biological activities is important for pharmacological studies and metabolic engineering. Therefore, this study was conducted to determine the variation of the chemical composition of essential oils obtained from Nectandra megapotamica leaves, collected at different stages of plant development, as well as its influence on the biological activities. A total of 38 compounds were identified that accounted for 97–99.2% of the chemical composition of the oils. Major differences were observed in the monoterpenic fraction, representing 5.1% of the compounds identified in the productive rest phase to 37.1% in the blooming phase. Bicyclogermacrene and germacrene D were the predominant compounds identified in the oil of all collections. Furthermore, limonene, β-pinene, and spathulenol were identified predominantly in the samples of blooming and fruiting phases. The oils exhibited significant antichemotactic activity and different effects in scavenging the radical 2,2-diphenyl-1-picrylhydrazyl. Variations were also observed in the antifungal activity, with the minimum inhibitory concentrations ranging from 125 to 500 μg/mL. These results demonstrate the influence of monoterpenes, primarily limonene, α-pinene, and β-pinene, on the bioactivities of the oil. Studies investigating the variations in the chemical composition of essential oil may offer a strategy to produce a compound or a group of compounds of interest to industries with a specific pharmacological focus

El presente como desafío del investigador: hábitats, trincheras y bunkers ante las emergencias sociales

Este trabajo abre una discusión en torno a las disciplinas y sus capacidades para atender las emergencias del presente. El artículo parte del análisis de las temáticas planteadas en diversas reuniones académicas (especialmente congresos de sociología, metodología de la investigación científica, etc.) entre los años 2009 y 2011 en América Latina. Observadas en su conjunto, el trabajo realiza un diagnóstico de la capacidad de las disciplinas y de los campos de estudios más constituidos para acercarse al tratamiento de los problemas de época, proponiendo una redefinición de las ciencias sociales a partir de la lectura de estos indicadores del estado actual y de los desafíos de las ciencias sociales de Latinoamérica.Instituto de Investigaciones en Humanidades y Ciencias Sociales (IdIHCS