Entity Network Extraction based on Association Finding and Relation Extraction

Abstract. One of the core aims of semantic search is to directly present users with information instead of lists of documents. Various entity-oriented tasks have been or are being considered, including entity search and related entity finding. In the context of digital libraries for computational humanities, we consider another task, network extraction: given an input entity and a document collection, extract related entities from the collection and present them as a network. We develop a combined approach for entity network extraction that consists of a co-occurrencebased approach to association finding and a machine learning-based approach to relation extraction. We evaluate our approach by comparing the results on a ground truth obtained using a pooling method.

Semantic grounding of tag relatedness in social bookmarking systems

Abstract. Collaborative tagging systems have nowadays become important data sources for populating semantic web applications. For tasks like synonym detection and discovery of concept hierarchies, many researchers introduced measures of tag similarity. Even though most of these measures appear very natural, their design often seems to be rather ad hoc, and the underlying assumptions on the notion of similarity are not made explicit. A more systematic characterization and validation of tag similarity in terms of formal representations of knowledge is still lacking. Here we address this issue and analyze several measures of tag similarity: Each measure is computed on data from the social bookmarking system del.icio.us and a semantic grounding is provided by mapping pairs of similar tags in the folksonomy to pairs of synsets in Wordnet, where we use validated measures of semantic distance to characterize the semantic relation between the mapped tags. This exposes important features of the investigated measures and indicates which measures are better suited in the context of a given semantic application.

La infusión intracerebroventricular prolongada de líquido cefalorraquídeo procedente de pacientes con esclerosis lateral amiotrófica provoca cambios histológicos en el cerebro y la médula espinal de la rata similares a los hallados en la enfermedad

Resumen: Introducción: La exposición de líquido cefalorraquídeo (LCR) de pacientes con esclerosis lateral amiotrófica (ELA) induce efectos citotóxicos en cultivos celulares de neuronas motoras in vitro. Material y métodos: Se seleccionó LCR de 32 pacientes con ELA que previamente habían demostrado efectos citotóxicos. Se implantaron con minibombas osmóticas intracerebroventriculares (ICV) en 28 ratas macho adultas y se dividieron en 3 grupos: 9 ratas de LCR de pacientes no-ELA, 15 ratas de ELA-LCR citotóxico y 4 ratas de una solución salina fisiológica. El LCR se administró por vía ICV de forma continua durante periodos de 20 o 43 días. Se realizó la evaluación clínica, electromiográfica y análisis de tejidos después de sacrificio a los 20, 45 y 82 días tras la cirugía. Resultados: Los estudios inmunohistoquímicos muestran daño en los tejidos con características similares a las encontradas en formas esporádicas de ELA, tales como sobre expresión de cistatina C, transferrina y la proteína en el TDP-43 citoplasmática. Los primeros cambios observados parecían jugar un papel protector por la sobreexpresión de periferina, panAKT, fosfoAKT y metalotioneínas; esta expresión habría disminuido al momento de analizar las ratas que se sacrificaron al día 82, en el que hay un aumento de apoptosis. Los primeros cambios celulares identificados fueron la constatación de activación de la microglía seguido por astrogliosis con sobreexpresión de GFAP y proteína S100B. Conclusiones: Nuestros datos parecen indicar que la ELA podría propagarse a través del LCR, y que la administración ICV de ELA-LCR citotóxico produce cambios similares a los encontrados en las formas esporádicas de la enfermedad. Abstract: Introduction: Cerebrospinal fluid (CSF) from amyotrophic lateral sclerosis (ALS) patients induces cytotoxic effects in in vitro cultured motor neurons. Material and methods: We selected CSF with previously reported cytotoxic effects from 32 ALS patients. Twenty-eight adult male rats were intracerebroventricularly implanted with osmotic mini-pumps and divided into 3 groups: 9 rats injected with CSF from non-ALS patients, 15 rats injected with cytotoxic ALS-CSF, and 4 rats injected with a physiological saline solution. CSF was intracerebroventricularly and continuously infused for periods of 20 or 43 days after implantation. We conducted clinical assessments and electromyographic examinations, and histological analyses were conducted in rats euthanised 20, 45, and 82 days after surgery. Results: Immunohistochemical studies revealed tissue damage with similar characteristics to those found in the sporadic forms of ALS, such as overexpression of cystatin C, transferrin, and TDP-43 protein in the cytoplasm. The earliest changes observed seemed to play a protective role due to the overexpression of peripherin, AKTpan, AKTphospho, and metallothioneins; this expression had diminished by the time we analysed rats euthanised on day 82, when an increase in apoptosis was observed. The first cellular changes identified were activated microglia followed by astrogliosis and overexpression of GFAP and S100B proteins. Conclusion: Our data suggest that ALS could spread through CSF and that intracerebroventricular administration of cytotoxic ALS-CSF provokes changes similar to those found in sporadic forms of the disease. Palabras clave: Esclerosis lateral amiotrófica, Modelo experimental ELA, Periferina, TDP-43, Enfermedades neurodegenerativas, Citotoxicidad, Keywords: Amyotrophic lateral sclerosis, ALS experimental model, Peripherin, TDP-43, Neurodegenerative diseases, Cytotoxicit

Histological changes in the rat brain and spinal cord following prolonged intracerebroventricular infusion of cerebrospinal fluid from amyotrophic lateral sclerosis patients are similar to those caused by the disease

Introduction: Cerebrospinal fluid (CSF) from amyotrophic lateral sclerosis (ALS) patients induces cytotoxic effects in in vitro cultured motor neurons. Materials and methods: We selected CSF with previously reported cytotoxic effects from 32 ALS patients. Twenty-eight adult male rats were intracerebroventricularly implanted with osmotic mini-pumps and divided into 3 groups: 9 rats injected with CSF from non-ALS patients, 15 rats injected with cytotoxic ALS-CSF, and 4 rats injected with a physiological saline solution. CSF was intracerebroventricularly and continuously infused for periods of 20 or 43 days after implantation. We conducted clinical assessments and electromyographic examinations, and histological analyses were conducted in rats euthanised 20, 45, and 82 days after surgery. Results: Immunohistochemical studies revealed tissue damage with similar characteristics to those found in the sporadic forms of ALS, such as overexpression of cystatin C, transferrin, and TDP-43 protein in the cytoplasm. The earliest changes observed seemed to play a protective role due to the overexpression of peripherin, AKTpan, AKTphospho, and metallothioneins; this expression had diminished by the time we analysed rats euthanised on day 82, when an increase in apoptosis was observed. The first cellular changes identified were activated microglia followed by astrogliosis and overexpression of GFAP and S100B proteins. Conclusion: Our data suggest that ALS could spread through CSF and that intracerebroventricular administration of cytotoxic ALS-CSF provokes changes similar to those found in sporadic forms of the disease. Resumen: Introducción: La exposición de líquido cefalorraquídeo (LCR) de pacientes con esclerosis lateral amiotrófica (ELA) induce efectos citotóxicos en cultivos celulares de neuronas motoras in vitro. Material y métodos: Se seleccionó LCR de 32 pacientes con ELA que previamente habían demostrado efectos citotóxicos. Se implantaron con minibombas osmóticas intracerebroventriculares (ICV) en 28 ratas macho adultas y se dividieron en 3 grupos: 9 ratas de LCR de pacientes no-ELA, 15 ratas de ELA-LCR citotóxico y 4 ratas de una solución salina fisiológica. El LCR se administró por vía ICV de forma continua durante periodos de 20 o 43 días. Se realizó la evaluación clínica, electromiográfica y análisis de tejidos después de sacrificio a los 20, 45 y 82 días tras la cirugía. Resultados: Los estudios inmunohistoquímicos muestran daño en los tejidos con características similares a las encontradas en formas esporádicas de ELA, tales como sobreexpresión de cistatina C, transferrina y la proteína en el TDP-43 citoplasmática. Los primeros cambios observados parecían jugar un papel protector por la sobreexpresión de periferina, panAKT, fosfoAKT y metalotioneínas; esta expresión habría disminuido al momento de analizar las ratas que se sacrificaron al día 82, en el que hay un aumento de apoptosis. Los primeros cambios celulares identificados fueron la constatación de activación de la microglía seguido por astrogliosis con sobreexpresión de GFAP y proteína S100B. Conclusiones: Nuestros datos parecen indicar que la ELA podría propagarse a través del LCR, y que la administración ICV de ELA-LCR citotóxico produce cambios similares a los encontrados en las formas esporádicas de la enfermedad. Keywords: Amyotrophic lateral sclerosis, ALS experimental model, Peripherin, TDP-43, Neurodegenerative diseases, Cytotoxicity, Palabras clave: Esclerosis lateral amiotrófica, Modelo experimental ELA, Periferina, TDP-43, Enfermedades neurodegenerativas, Citotoxicida

Adaptive Systems in the Era of the Semantic Web and Social Web, a survey

This paper presents an analysis and a classification of adaptive systems with respect to the kind of semantic technology they exploit to accomplish or improve specific adaptation and user modeling tasks. This classification is based on a distinction between strong semantic techniques and weak semantic techniques. The former techniques are based on the Semantic Web, while the latter regard technologies that, in different ways, annotate resources, enriching their meaning. This second category includes, in particular, Web 2.0 social annotations and mixed approaches between social annotations and Semantic Web techniques. While the impact of the Semantic Web on adaptive systems has been discussed in several survey papers, the potential of weak semantic technologies has received less attention. The original contribution of this study is to fill this gap by providing an overall analysis of the use of all forms of knowledge annotation to implement and carry out task and sub-tasks of user modelling and user-adapted systems