Building a Sentiment Corpus of Tweets in Brazilian Portuguese

The large amount of data available in social media, forums and websites motivates researches in several areas of Natural Language Processing, such as sentiment analysis. The popularity of the area due to its subjective and semantic characteristics motivates research on novel methods and approaches for classification. Hence, there is a high demand for datasets on different domains and different languages. This paper introduces TweetSentBR, a sentiment corpora for Brazilian Portuguese manually annotated with 15.000 sentences on TV show domain. The sentences were labeled in three classes (positive, neutral and negative) by seven annotators, following literature guidelines for ensuring reliability on the annotation. We also ran baseline experiments on polarity classification using three machine learning methods, reaching 80.99% on F-Measure and 82.06% on accuracy in binary classification, and 59.85% F-Measure and 64.62% on accuracy on three point classification.Comment: Accepted for publication in 11th International Conference on Language Resources and Evaluation (LREC 2018

Caracterización molecular de variantes del virus Junín con diferentes grados de virulencia

El objetivo principal de este trabajo, consistió en el estudio de la información contenida en el genoma del virus Junín, en relación al fenómeno de atenuación de la virulencia. - Como objetivo secundario, se estudió la filogenia en la familia de los arenavirus y se analizaron las relaciones evolutivas entre los mismos. - Además, se diseñó un método para la detección de nuevos arenavirus a nivel molecular, en base al análisis de secuencias mencionado arriba. - Finalmente, se estudió el papel de la proteína de la nucleocápside en la regulación de los procesos de transcripción y replicación en el virus Junín. Con el fin de organizar el contenido y favorecer la presentación de este estudio resultó conveniente la división en capítulos, a saber: introducción, materiales y métodos, análisis y discusión de los resultados, conclusiones generales y referencias bibliográficas. A continuación, se resume brevemente el contenido de cada capítulo. 1. En el primer capítulo, se realiza una descripción introductoria sobre la estructura del virus Junín y su relación con la fiebre hemorrágica. En particular, se analiza la información disponible y los antecedentes bibliográficos que forman el contexto para el desarrollo de este estudio. 2. En el segundo capítulo se describen los materiales y los métodos utilizados en el transcurso de este estudio. 3. En el tercer capítulo se aborda específicamente, el problema de la atenuación de la virulencia en las cepas relacionadas genealógicamente con el virus vacunal, Junín Candid #1. 4. En el cuarto capítulo, se analiza la filogenia en la familia de los arenavirus y las posibles relaciones evolutivas entre los mismos. 5. En el quinto capítulo, se describe el diseño de un procedimiento experimental que permitió caracterizar un nuevo arenavirus. Este trabajo se realizó en colaboración con el Dr. M.E. Lozano y el Lic. D.M. Posik. 6. En el sexto capítulo, se analiza el control de la transcripción en el virus Junín. Este trabajo se realizó en colaboración con el Dr. R.V. Rivera Pomar y el Dr. M.E. Lozano. 7. En el séptimo capítulo, se establecen las conclusiones generales del presente estudio. 8. En el último capítulo, se listan las referencias bibliográficas relacionadas con los capítulos anteriores.Tesis digitalizada en SEDICI gracias a la Biblioteca Central de la Facultad de Ciencias Exactas (UNLP).Facultad de Ciencias Exacta

Caracterización molecular de variantes del virus Junín con diferentes grados de virulencia

El objetivo principal de este trabajo, consistió en el estudio de la información contenida en el genoma del virus Junín, en relación al fenómeno de atenuación de la virulencia. - Como objetivo secundario, se estudió la filogenia en la familia de los arenavirus y se analizaron las relaciones evolutivas entre los mismos. - Además, se diseñó un método para la detección de nuevos arenavirus a nivel molecular, en base al análisis de secuencias mencionado arriba. - Finalmente, se estudió el papel de la proteína de la nucleocápside en la regulación de los procesos de transcripción y replicación en el virus Junín. Con el fin de organizar el contenido y favorecer la presentación de este estudio resultó conveniente la división en capítulos, a saber: introducción, materiales y métodos, análisis y discusión de los resultados, conclusiones generales y referencias bibliográficas. A continuación, se resume brevemente el contenido de cada capítulo. 1. En el primer capítulo, se realiza una descripción introductoria sobre la estructura del virus Junín y su relación con la fiebre hemorrágica. En particular, se analiza la información disponible y los antecedentes bibliográficos que forman el contexto para el desarrollo de este estudio. 2. En el segundo capítulo se describen los materiales y los métodos utilizados en el transcurso de este estudio. 3. En el tercer capítulo se aborda específicamente, el problema de la atenuación de la virulencia en las cepas relacionadas genealógicamente con el virus vacunal, Junín Candid #1. 4. En el cuarto capítulo, se analiza la filogenia en la familia de los arenavirus y las posibles relaciones evolutivas entre los mismos. 5. En el quinto capítulo, se describe el diseño de un procedimiento experimental que permitió caracterizar un nuevo arenavirus. Este trabajo se realizó en colaboración con el Dr. M.E. Lozano y el Lic. D.M. Posik. 6. En el sexto capítulo, se analiza el control de la transcripción en el virus Junín. Este trabajo se realizó en colaboración con el Dr. R.V. Rivera Pomar y el Dr. M.E. Lozano. 7. En el séptimo capítulo, se establecen las conclusiones generales del presente estudio. 8. En el último capítulo, se listan las referencias bibliográficas relacionadas con los capítulos anteriores.Tesis digitalizada en SEDICI gracias a la Biblioteca Central de la Facultad de Ciencias Exactas (UNLP).Doctor en Ciencias ExactasUniversidad Nacional de La PlataFacultad de Ciencias Exacta

Development of a RVFV ELISA that can distinguish infected from vaccinated animals

<p>Abstract</p> <p>Background</p> <p>Rift Valley Fever Virus is a pathogen of humans and livestock that causes significant morbidity and mortality throughout Africa and the Middle East. A vaccine that would protect animals from disease would be very beneficial to the human population because prevention of the amplification cycle in livestock would greatly reduce the risk of human infection by preventing livestock epizootics. A mutant virus, constructed through the use of reverse genetics, is protective in laboratory animal models and thus shows promise as a potential vaccine. However, the ability to distinguish infected from vaccinated animals is important for vaccine acceptance by national and international authorities, given regulations restricting movement and export of infected animals.</p> <p>Results</p> <p>In this study, we describe the development of a simple assay that can be used to distinguish naturally infected animals from ones that have been vaccinated with a mutant virus. We describe the cloning, expression and purification of two viral proteins, and the development of side by side ELISAs using the two viral proteins.</p> <p>Conclusion</p> <p>A side by side ELISA can be used to differentiate infected from vaccinated animals. This assay can be done without the use of biocontainment facilities and has potential for use in both human and animal populations.</p

In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

Zinc-binding properties of Junín virus nucleocapsid protein

The arenavirus nucleocapsid protein (N) is a highly basic 63 kDa protein with a dual function during the virus life-cycle. First, it is involved in essential steps of genome replication, promoting the synthesis of the full-length antigenomic copy of S RNA, and second it associates with the genomic RNA to form the nucleocapsid. We have expressed the N protein of Junín virus in E. coli and shown that it binds zinc in vitro. This property is in agreement with the presence in the carboxy-terminal region of the N protein of the CX2HX23CX4C sequence, which resembles a classical zinc-finger motif. The specificity for zinc binding was demonstrated by competition with other divalent metal ions. The ability of the predicted motif to bind zinc was established by analysis of a series of N mutants, including truncated variants and amino acid substitutions. In addition, alternative zinc-binding sites were found.Instituto de Biotecnologia y Biologia Molecula

Generation of a Recombinant Anticarsia Gemmatalis Multicapsid Nucleopolyhedrovirus Expressing a Foreign Gene under the Control of a Very Late Promoter

A recombinant Anticarsia gemmatalis multicapsid nucleopolyhedrovirus (AgMNPV) expressing β-galactosidase under the control of the polyhedrin promoter was generated in our laboratory. To this end, we cloned the AgMNPV-2D genomic DNA fragment containing the polh gene and subcloned and sequenced the polyhedrin gene and its flanking regions. Based on this sequence information, sets of primers were designed to amplify the flanking regions by PCR, including appropriate restriction sites. The transfer vector (pAgPHZ) was constructed by the consecutive cloning of these PCR fragments flanking the Escherichia coli LacZ gene, in place of the polh gene. pAgPHZ was used for cotransfection of UFL-AG-286 insect cells with AgMNPV-2D DNA and the required recombinant, generated by homologous recombination with the polh locus, was identified by its polh⁻/LacZ⁺ plaque phenotype. Its genome structure was confirmed by PCR, restriction digestion and Southern blot analyses. The kinetics and levels of expression of β-galactosidase in UFL-AG-286 cells infected with the recombinant were tested by SDS-PAGE and enzymatic activity assays.Instituto de Biotecnología y Biología Molecula

In vitro and in vivo herpetic vector-mediated gene transfer in the pituitary gland: Impact on hormone secretion

Objective: Herpes simplex virus type 1 (HSV-1)-derived vectors are known to be effective tools to deliver transgenes into normal and neoplastic anterior pituitary (AP) cells in vitro. Our objective was to assess the in vitro and in vivo effects of tsK/β-gal, a temperature-sensitive HSV-1-derived vector harbouring the E. coli β-galactosidase gene, on AP hormone secretion as well as on transgene expression in rat AP tumours (hyperplastic prolactinomas). Design: The impact of vector infection on prolactin (PRL) and GH release was determined in vitro in normal and hyperplastic (lactotrophic) dispersed AP cells exposed for 24 h to tsK/β-gal as well as in vivo in ectopic AP grafts. In some oestrogen-induced prolactinoma-carrying rats, vector suspension was stereotaxically injected into the glands to assess transgene expression in vivo. Methods: GH and PRL release was measured by specific RIAs. In vivo transgene expression was assessed by immunohistochemistry for β-galactosidase and enzymohistochemistry (5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside). Ectopic pituitary grafts and stereotaxic surgery were performed following standard procedures. Results: At a multiplicity of infection of 0.5, the vector induced a 30 and 22% fall in PRL and GH release respectively in normal AP cells, whereas the corresponding hormone release inhibition for hyperplastic AP cells was 41 and 33% for PRL and GH respectively. In ectopic pituitary grafts, the effect of vector infection on hormone secretion was assessed by measuring serum PRL levels in the host rats every 5 days for 4 weeks post-grafting. In the pituitary-grafted rats that received the viral vector, serum PRL failed to increase to the levels achieved in control-grafted animals. Finally, pituitary tumours stereotaxically injected with tsK/β-gal showed widespread expression of the β-galactosidase transgene around the injection areas. Conclusions: The results reported here have implications for basic studies using gene transfer to pituitary gland as well as potential gene therapy approaches to pituitary diseases.Instituto de Investigaciones Bioquímicas de La PlataInstituto de Biotecnologia y Biologia MolecularInstituto Multidisciplinario de Biología Celula

Arenavirus phylogeny: a new insight

Arenaviridae is a worldwide distributed family, of enveloped, single stranded, RNA viruses. The arenaviruses were divided in two major groups (Old World and New World), based on serological properties and genetic data, as well as the geographic distribution. In this study the phylogenetic relationship among the members of the Arenaviridae was examined, using the reported genomic sequences. The comparison of the aligned nucleotide sequences of the S RNA and the predicted amino acid sequences of the GPC and N proteins, together with the phylogenetic analysis, strongly suggest a possible kinship of Pichinde and Oliveros viruses, with the Old World arenavirus group. This analysis points at the evolutive relationships between the arenaviruses of the Americas and can be used to evaluate the different hypotheses about their origin.Instituto de Investigaciones Bioquímicas de La Plat