Análisis mesoclimático de las cartas topográficas Santa Rosa y Villa María (1:250.000) de la provincia de Córdoba (Argentina)

p.73-76

Efectos de ácidos orgánicos y etanol en el proceso de fijación de nitrógeno atmosférico en el suelo

p.31-35

Indicadores de calidad de la tierra en distintas posiciones de la cuenca del Río Santa María

p.111-115

Conductividad hidráulica saturada de perlita para distintos tiempos de uso en cultivo de rosas bajo cubierta

p.227-232

Comparación de métodos de estabilidad estructural y variabilidad de los resultados en un suelo de la serie Ramallo (Argiudol vértico)

p.103-112

Construyendo matemáticas con nuestro abanico: funciones sinusoidales

El estudio de las funciones sinusoidales en la secundaria y en el bachillerato se suele realizar desde una perspectiva alejada de la experimentación y la intuición. En este artículo pretendemos mostrar una propuesta de trabajo para introducir las funciones sinusoidales de una manera intuitiva y experimental, en una fase previa a su estudio analítico, a través de algunos ejemplos de la vida cotidiana como andar, parpadear, fregar el suelo o hacer abdominales.

Analysis of the footprint in school age of 8-10 years old

Biomechanical problems in children, is an important subject currently, existing controversy in different areas, for example, the majority of children have a flattened footprint, or the hypermobility joint is linked to a musculoskeletal pain. The objective of the study was to determine what kind of footprint is most frequent in school-age children (8-10 years) in the area of Plasencia. This was taken as a sign 50 children, of whom 28 were males and 22 females. All the subjects in the study underwent an assessment of footprint planted in static as well as an exploration of different parameters through inspection in a standing position (formula digital, rearfoot). The results show that excavated footprint is present in a 72% cases of the population, 16% was belonging to an excavated footprint in which we find a higher percentage of weight related.For the digital formula we find that the most common is the Egyptian foot by 40% of the cases and that the prevalence in the rearfoot, is a normal hindfoot. In relation with the hypermobility joint, we check that it is more common in girls and that none of them presents an association to musculoskeletal pain. As a future line we could establish a more comprehensive study with new techniques and valuingchild’s statics and dynamics, to have a more accurate study of the different variables in the sample population studied.

MarA-mediated transcriptional repression of the rob promoter

The Escherichia coli transcriptional regulator MarA affects functions that include antibiotic resistance, persistence, and survival. MarA functions as an activator or repressor of transcription utilizing similar degenerate DNA sequences (marboxes) with three different binding site configurations with respect to the RNA polymerase-binding sites. We demonstrate that MarA down-regulates rob transcripts both in vivo and in vitro via a MarA-binding site within the rob promoter that is positioned between the -10 and -35 hexamers. As for the hdeA and purA promoters, which are repressed by MarA, the rob marbox is also in the "backward" orientation. Protein-DNA interactions show that SoxS and Rob, like MarA, bind the same marbox in the rob promoter. Electrophoretic mobility shift analyses with a MarA-specific antibody demonstrate that MarA and RNA polymerase form a ternary complex with the rob promoter DNA. Transcription experiments in vitro and potassium permanganate footprinting analysis show that MarA affects the RNA polymerase-mediated closed to open complex formation at the rob promoter.

The Escherichia coli transcriptional regulator MarA directly represses transcription of purA and hdeA

The Escherichia coli MarA protein mediates a response to multiple environmental stresses through the activation or repression in vivo of a large number of chromosomal genes. Transcriptional activation for a number of these genes has been shown to occur via direct interaction of MarA with a 20-bp degenerate asymmetric "marbox" sequence. It was not known whether repression by MarA was also direct. We found that purified MarA was sufficient in vitro to repress transcription of both purA and hdeA. Transcription and electrophoretic mobility shift experiments in vitro using mutant promoters suggested that the marbox involved in the repression overlapped the -35 promoter motif and was in the "backward" orientation. This organization contrasts with that of the class II promoters activated by MarA, in which the marbox also overlaps the -35 motif but is in the "forward" orientation. We conclude that MarA, a member of the AraC/XylS family, can act directly as a repressor or an activator, depending on the position and orientation of the marbox within a promoter.

Curso: Representaciones de la metrópolis en la literatura y cine latinoamericanos a partir de 1960

l seminario sigue la línea establecida en el curso sobre los “Clásicos de la literatura de la metrópolis” impartido durante el semestre de 2008-2. En este semestre, se analizan novelas, cuentos, crónicas y películas latinoamericanos producidos a partir de 1960. Interpretamos textos desde el ciclo novelístico de Santa María, de Juan Carlos Onetti, pasando por el llamado boom de la década de 1960 (Guillermo Cabrera Infante, Julio Cortázar) y las crónicas mexicanas de los años 70 y 80 (Carlos Monsiváis, Cristina Pacheco, Elena Poniatowska) hasta llegar al análisis de novelas y cuentos más recientes de autores como Carmen Boullosa, Guillermo Fadanelli, Juan Forns, Ricardo Piglia, Guillermo Samperio, Fernando Vallejo, Rafael Ramírez Heredia. Además, analizamos películas recientes como: El callejón de los milagros, La virgen de los sicarios, Ciudade de Deus y Amores perros.