¿La gramática escolar en cuestión? : La materia Construcción de Ciudadanía en las escuelas secundarias de la provincia de Buenos Aires

Este trabajo es resultado del procesamiento y análisis de una encuesta autoadministrada aplicada en el año 2009 a los docentes a cargo de la asignatura Construcción de la Ciudadanía. Incluyó un relevamiento con preguntas cerradas y abiertas que intentaba conocer el perfil de los docentes, las condiciones de implementación de la materia, la asistencia, la gradualidad, la evaluación y los aportes realizados por la asignatura a la dinámica institucional y a la educación secundaria obligatoria. Tiene por objetivo presentar algunas reflexiones que aporten al debate sobre las posibilidades de innovación curricular en las instituciones educativas. Al mismo tiempo que insinúa una tendencia, por parte de los docentes, a preservar la gramática escolar frente a los cambios que pretende orientar el Diseño Curricular de esta materia.Facultad de Humanidades y Ciencias de la Educació

Pathogenicity island cag, vacA and IS605 genotypes in Mexican strains of Helicobacter pylori associated with peptic ulcers

<p>Abstract</p> <p>Background</p> <p><it>Helicobacter pylori </it>is associated with chronic gastritis, peptic ulcers, and gastric cancer. Two major virulence factors of <it>H. pylori </it>have been described: the pathogenicity island <it>cag </it>(<it>cag </it>PAI) and the vacuolating cytotoxin gene (<it>vacA</it>). Virtually all strains have a copy of <it>vacA</it>, but its genotype varies. The <it>cag </it>PAI is a region of 32 genes in which the insertion of IS<it>605 </it>elements in its middle region has been associated with partial or total deletions of it that have generated strains with varying virulence. Accordingly, the aim of this work was to determine the <it>cag </it>PAI integrity<it>, vacA </it>genotype and IS<it>605 </it>status in groups of isolates from Mexican patients with non-peptic ulcers (NPU), non-bleeding peptic ulcers (NBPU), and bleeding peptic ulcers (BPU).</p> <p>Methods</p> <p>The <it>cag </it>PAI integrity was performed by detection of eleven targeted genes along this locus using dot blot hybridization and PCR assays. The <it>vacA </it>allelic, <it>cag </it>PAI genotype 1 and IS<it>605 </it>status were determined by PCR analysis.</p> <p>Results</p> <p>Groups of 16-17 isolates (n = 50) from two patients with NPU, NBPU, and BPU, respectively, were studied. 90% (45/50) of the isolates harbored a complete <it>cag </it>PAI. Three BPU isolates lacked the <it>cag </it>PAI, and two of the NBPU had an incomplete <it>cag </it>PAI: the first isolate was negative for three of its genes, including deletion of the <it>cagA </it>gene, whereas the second did not have the <it>cagM </it>gene. Most of the strains (76%) had the <it>vacA </it>s1b/m1 genotype; meanwhile the IS<it>605 </it>was not present within the <it>cag </it>PAI of any strain but was detected elsewhere in the genome of 8% (4/50).</p> <p>Conclusion</p> <p>The patients had highly virulent strains since the most of them possessed a complete <it>cag </it>PAI and had a <it>vacA </it>s1b/m1 genotype. All the isolates presented the <it>cag </it>PAI without any IS<it>605 </it>insertion (genotype 1). Combined <it>vacA </it>genotypes showed that 1 NPU, 2 NBPU, and 1 BPU patients (66.6%) had a mixed infection; coexistence of <it>H. pylori </it>strains with different <it>cag </it>PAI status was observed in 1 NBPU and 2 BPU (50%) of the patients, but only two of these patients (NBPU and BPU) had different <it>vacA </it>genotypes.</p

Morphology and Sequence Data of Mexican Populations of the Ciliate Parasite of Marine Fishes Trichodina rectuncinata (Ciliophora: Trichodinidae)

Trichodina rectuncinata is one of the trichodinids most widely distributed in marine fish. This ciliate species has been recorded in more than 20 host species belonging to 17 fish families worldwide. Previous comparative studies based on morphometric data revealed considerable morphological variation among specimens from different populations of T. rectuncinata. In this study, we conducted a morphometric- molecular analysis of three populations of T. rectuncinata to evaluate potential differences among 18S rRNA sequences, in relation to morphological variations. Smears were obtained from marine fishes in three localities along the Pacific coast of Mexico. Based on the shape of denticles, we found four different morphotypes for T. rectuncinata. This morphological variability does not correspond with the genetic divergence, suggesting that all analyzed populations belong to the same species. Further analyses using more variable markers are necessary to corroborate the findings of our study.Fil: Islas Ortega, Alma G.. Universidad Nacional Autónoma de México; MéxicoFil: Aguilar Aguilar, Rogelio. Universidad Nacional Autónoma de México; MéxicoFil: Marcotegui, Paula Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Martorelli, Sergio Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Centro de Estudios Parasitológicos y de Vectores. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Centro de Estudios Parasitológicos y de Vectores; ArgentinaFil: Hernández Mena, David. Universidad Nacional Autónoma de México; MéxicoFil: Pérez Ponce de León, Gerardo. Universidad Nacional Autónoma de México; Méxic

Morphology and Sequence Data of Mexican Populations of the Ciliate Parasite of Marine Fishes Trichodina rectuncinata (Ciliophora: Trichodinidae)

Trichodina rectuncinata is one of the trichodinids most widely distributed in marine fish. This ciliate species has been recorded in more than 20 host species belonging to 17 fish families worldwide. Previous comparative studies based on morphometric data revealed considerable morphological variation among specimens from different populations of T. rectuncinata. In this study, we conducted a morphometric- molecular analysis of three populations of T. rectuncinata to evaluate potential differences among 18S rRNA sequences, in relation to morphological variations. Smears were obtained from marine fishes in three localities along the Pacific coast of Mexico. Based on the shape of denticles, we found four different morphotypes for T. rectuncinata. This morphological variability does not correspond with the genetic divergence, suggesting that all analyzed populations belong to the same species. Further analyses using more variable markers are necessary to corroborate the findings of our study.Centro de Estudios Parasitológicos y de Vectore

Morphology and Sequence Data of Mexican Populations of the Ciliate Parasite of Marine Fishes Trichodina rectuncinata (Ciliophora: Trichodinidae)

Trichodina rectuncinata is one of the trichodinids most widely distributed in marine fish. This ciliate species has been recorded in more than 20 host species belonging to 17 fish families worldwide. Previous comparative studies based on morphometric data revealed considerable morphological variation among specimens from different populations of T. rectuncinata. In this study, we conducted a morphometric- molecular analysis of three populations of T. rectuncinata to evaluate potential differences among 18S rRNA sequences, in relation to morphological variations. Smears were obtained from marine fishes in three localities along the Pacific coast of Mexico. Based on the shape of denticles, we found four different morphotypes for T. rectuncinata. This morphological variability does not correspond with the genetic divergence, suggesting that all analyzed populations belong to the same species. Further analyses using more variable markers are necessary to corroborate the findings of our study.Centro de Estudios Parasitológicos y de Vectore

Molecular data reveal hidden diversity of the genus <i>Clinostomum</i> (Digenea, Clinostomidae) in Argentina, with the description of a new species from <i>Ardea cocoi</i> (Ardeidae)

The genus Clinostomum has been recently a subject of a large number of molecular phylogenetic studies that have uncovered a larger species diversity than we thought. In Argentina, only two nominal species have been reported, namely C. detruncatum and C. marginatum. Three putative species represented by metacercariae were recently molecularly diagnosed, and there are at least two additional metacercarial morphotypes diagnosed on morphological grounds. Here, we molecularly characterized specimens of Clinostomum sampled from freshwater fishes and fish-eating birds from Argentina through mtDNA cytochrome c oxidase subunit I (COI). Unexpectedly, the phylogenetic analysis uncovered three new additional genetic lineages, two of them corresponding to metacercarial stages and another matching COI sequences of C. heluans Braun, 1899, being considered conspecific, whereas the others still require formal description. Additionally, we add a new host species for a lineage molecularly diagnosed in a previous study. The adult specimens recovered from A. cocoi in Buenos Aires Province represented a new species clearly distinguished from the two species previously reported in Argentina. Clinostomum detruncatum is distinguished from the new species by possessing a characteristic tenoidean uterus, and testes located more posteriorly. Clinostomum marginatum is morphologically similar but differs from the new species in having rounded ovary, posterior testis lobated, and lateral cirrus-sac and displacing the anterior testis, and vitelline follicles not extending beyond the caeca end. Our study raises the number of Clinostomum species in Argentina up to 10. We describe the new species herein.Facultad de Ciencias Naturales y MuseoCentro de Estudios Parasitológicos y de Vectore