Reconocimiento de acto de diálogo secuencial para debates argumentativos árabes

Dialogue act recognition remains a primordial task that helps user to automatically identify participants’ intentions. In this paper, we propose a sequential approach consisting of segmentation followed by annotation process to identify dialogue acts within Arabic politic debates. To perform DA recognition, we used the CARD corpus labeled using the SADA annotation schema. Segmentation and annotation tasks were then carried out using Conditional Random Fields probabilistic models as they prove high performance in segmenting and labeling sequential data. Learning results are notably important for the segmentation task (F-score=97.9%) and relatively reliable within the annotation process (f-score=63.4%) given the complexity of identifying argumentative tags and the presence of disfluencies in spoken conversations.El reconocimiento del acto de diálogo sigue siendo una tarea primordial que ayuda al usuario a identificar automáticamente las intenciones de los participantes. En este documento, proponemos un enfoque secuencial que consiste en la segmentación seguida de un proceso de anotación para identificar actos de diálogo dentro de los debates políticos árabes. Para realizar el reconocimiento DA, utilizamos el corpus CARD etiquetado utilizando el esquema de anotación SADA. Las tareas de segmentación y anotación se llevaron a cabo utilizando modelos probabilísticos de Campos aleatorios condicionales, ya que demuestran un alto rendimiento en la segmentación y el etiquetado de datos secuenciales. Los resultados de aprendizaje son especialmente importantes para la tarea de segmentación (F-score = 97.9%) y relativamente confiables dentro del proceso de anotación (f-score = 63.4%) dada la complejidad de identificar etiquetas argumentativas y la presencia de disfluencias en las conversaciones habladas

Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination

Lipases are useful enzymes that are responsible for the hydrolysis of triacylglycerides and play an important role in plant growth. In this study, we report a rapid molecular method to amplify a partial sequence of the lipase class 3 family designated BnLIP3 gene of Brassica napus L. in order to follow its expression and analyze its role during seed germination. Therefore, we conceived PCR homologous primers to amplify the active site encoding region of the BnLIP3 family genes. Subsequently, to sequence determination of the 582 bp fragment, we deduced BnLIP3 specific primers for a nested RTPCR application. The deduced 194 amino acid sequence (Genbank 1160264) was found to share 85% of identity with lipase from Arabidopsis thaliana class 3 family. The GxSxG consensus motif near the catalytic triad at the active serine site was also identified. The peptidic sequence showed little homology with mammalian and microbial lipases. RT-PCR analysis indicated that BnLIP3 gene was expressed during B. napus seed germination.Keywords: Brassica napus L., GxSxG lipase, germination, BnLIP3, RT-PCR.African Journal of Biotechnology Vol. 12(25), pp. 3905-391

Cloning, Sequence Analysis and Expression Patterns during Seed Germination of a Rapeseed (Brassica napus L.) G-x-S-x-G-motif Lipase Gene

[EN] Lipases catalyze the hydrolysis of ester bonds in triacylglycerides, generating glycerol and free fatty acids. These enzymes are encoded by extremely complex gene families, and appear to fulfil many different biological functions. Although they are present in all types of organisms, available information on plant lipases is still very limited, as compared to their bacterial and animal counterparts. A full-length clone, BnLIP, encoding a putative lipase, has been isolated by PCR amplification of Brassica napus genomic DNA, with oligonucleotide primers derived from the sequence of an Arabidopsis thaliana homologue. The clone included an open reading frame of 1581 bp encoding a polypeptide of 526 amino acids, with a calculated molecular mass of 59.5 kDa. Analysis of the deduced protein sequence, sequence alignment with homologous proteins from related plant species, and a phylogenetic analysis revealed that the BnLIP protein belongs to the classical GxSxG-motif lipase family. RTPCR assays indicated that the BnLIP gene is expressed specifically, but only transiently, during seed germination: the lipase mRNA was not present at detectable levels in ungerminated seeds, was detected only three days after seed imbibition, but its levels decreased rapidly afterwards. No expression was observed in roots, stems or leaves of adult plants. This expression pattern suggests that BnLIP is one of the lipases involved in the hydrolysis of triacylglycerides stored in rapeseed seeds, ultimately providing nutrients and energy to sustain seedling growth until photosynthesis is activatedGlaied Ghram, I.; Belguith, H.; Ben Mustapha, M.; Himila, I.; Bouhaouala, B.; Vicente, O.; Ben Hamida, J. (2016). Cloning, Sequence Analysis and Expression Patterns during Seed Germination of a Rapeseed (Brassica napus L.) G-x-S-x-G-motif Lipase Gene. Notulae Botanicae Horti Agrobotanici Cluj-Napoca. 44(2):437-444. doi:10.15835/nbha4421047243744444

Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination

Lipases are useful enzymes that are responsible for the hydrolysis of triacylglycerides and play an important role in plant growth. In this study, we report a rapid molecular method to amplify a partial sequence of the lipase class 3 family designated BnLIP3 gene of Brassica napus L. in order to follow its expression and analyze its role during seed germination. Therefore, we conceived PCR homologous primers to amplify the active site encoding region of the BnLIP3 family genes. Subsequently, to sequence determination of the 582 bp fragment, we deduced BnLIP3 specific primers for a nested RTPCR application. The deduced 194 amino acid sequence (Genbank 1160264) was found to share 85% of identity with lipase from Arabidopsis thaliana class 3 family. The GxSxG consensus motif near the catalytic triad at the active serine site was also identified. The peptidic sequence showed little homology with mammalian and microbial lipases. RT-PCR analysis indicated that BnLIP3 gene was expressed during B. napus seed germination.Glaied Ghram, I.; Belguith, H.; Messaoudi, A.; Fattouch, S.; Vicente Meana, Ó.; Ben Hamida, J. (2013). Amplification of the active site of BnLIP3 gene of Brassica napus L. during germination. African Journal of Biotechnology. 12(25):3905-3913. doi:10.5897/AJB12.2861S39053913122

Three-Dimensional Structure of Lipase Predicted by Homology Modeling Method

Triacylglycerol lipases have been thoroughly characterized in mammals and microorganisms. By contrast, very little is known about plant lipases. In this investigation, a homology model of Arabidopsis thaliana lipase (NP_179126) was constructed using a human gastric lipase (PDB ID: 1HLG), as a template for model building. This model was then assessed for stereochemical quality and side chain environment. Natural substrates: tributyrin, trioctanoin and triolen were docked into the model to investigate ligand-substrate interaction