Prueba de interacción en el análisis molecular de varianza / Test of interaction in the analysis of molecular variance

La diversidad genómica, expresada en las diferencias entre haplotipos moleculares de un conjunto de individuos, puede dividirse en componentes de variabilidad entre y dentro de algún factor de clasificación de los individuos. Para tal partición de varianzas, se usa análisis molecular de la varianza (AMOVA), el cual se construye a partir de las distancias multivariadas entre pares de haplotipos. El AMOVA clásico permite evaluar la significancia estadística de dos o más factores jerárquicos y consecuentemente no existe prueba de interacción entre factores. Sin embargo, existen situaciones donde los factores que clasifican a los individuos están cruzados y no anidados, es decir todos los niveles de un factor se encuentran representados en cada nivel del otro factor. Este trabajo propone una prueba estadística para evaluar la interacción entre factores cruzados en un AMOVA No-Jerárquico. La hipótesis nula de interacción establece que las diferencias moleculares entre individuos de distintos niveles de un factor son las mismas para todos los niveles del otro factor que los clasifica. La propuesta de análisis de interacción de factores a partir de distancias en un AMOVA No-Jerárquico comprende: cálculo de la matriz de distancia y partición de la misma en bloques, posterior cálculo de residuos y análisis de varianza no-paramétrico sobre los residuos. Su implementación es ilustrada en escenarios simulados y real. Los resultados sugieren que la prueba de interacción propuesta para el AMOVA No- Jerárquico presenta alta potencia.

The genomic diversity, expressed in the differences between molecular haplotypes of a group of individuals, can be divided into components of variability between and within some factor of classification of the individuals. For such variance partitioning, molecular analysis of variance (AMOVA) is used, which is constructed from the multivariate distances between pairs of haplotypes. The classical AMOVA allows the evaluation of the statistical significance of two or more hierarchical factors and consequently there is no interaction test between factors. However, there are situations where the factors that classify individuals are crossed rather than nested, that is, all the levels of a factor are represented in each level of the other one. This paper proposes a statistical test to evaluate the interaction between crossed factors in a Non-Hierarchical AMOVA. The null hypothesis of interaction establishes that the molecular differences between individuals of different levels of a factor are the same for all the levels of the other factor that classifies them. The proposed analysis of interaction in a Non- Hierarchical AMOVA includes: calculation of the distance matrix and partition of it into blocks, subsequent calculation of residuals and analysis of non-parametric variance on the residuals. Its implementation is illustrated in simulated and real scenarios. The results suggest that the proposed interaction test for the Non-Hierarchical AMOVA presents high power.

Aminopropyl-modified mesoporous silica SBA-15 as recovery agents of Cu(II)-sulfate solutions: Adsorption efficiency, functional stability and reusability aspects.

Hybrid mesoporous materials are potentially useful for metal ion scavenging and retrieval because of their high surface areas, controlled accessibility and tailored functionalization. Some aspects that are linked to the performance of HMM include pore accessibility, stability of the organic functions and reusability. Knowledge of these aspects is critical in the design of adsorption-desorption protocols. In this work we produce and characterize propylamino-substituted large pore silica (SBA-15-N), which is submitted to Cu(II) adsorption from copper sulfate solutions, followed by desorption in acid media and material regeneration. We find that the hybrid material is an efficient adsorbent (1.15-1.75mmol Cu(II)g(-1)), although a fraction of the organic groups is lost during the adsorption process. An X-ray photoelectron spectroscopy (XPS) study demonstrates that the contents of amino groups are higher in the material surface, leading to different behaviors in Cu(II) complexation along the material. These materials can be regenerated by exposure to acidic media. Thermal processing of the hybrid materials leads to better durability in aqueous solutions during reprocessing, due to enhanced polycondensation of the inorganic framework. Thermally treated samples, once regenerated, are efficient adsorbents in a second step of Cu(II) adsorption. We discuss the materials processing factors involved in the improved adsorption of Cu(II), its quantitative release and reusability of the material.

Micropropagation of Glandularia perakii Cov. et Schn. (Verbenaceae), a native species with ornamental potential

Glandularia perakii is a perennial species with beautiful violet flowers that grows in the stony soil of Mendocine pedemont. A plentiful and prolonged flowering confers it an important ornamental potential. In this paper, a method of propagation of G. perakii from nodal segments is reported. Proliferating microshoot cultures were obtained by placing nodal segment on Murashige and Skoog medium (MS) supplemented with 20 g.L-1 of sucrose without growth regulators. In this medium multiplication rate after 20 days was 7.9. Rooted plants were acclimatized successfully.

Micropropagation of Glandularia perakii Cov. et Schn. (Verbenaceae), a native species with ornamental potential

Glandularia perakii is a perennial species with beautiful violet flowers that grows in the stony soil of Mendocine pedemont. A plentiful and prolonged flowering confers it an important ornamental potential. In this paper, a method of propagation of G. perakii from nodal segments is reported. Proliferating microshoot cultures were obtained by placing nodal segment on Murashige and Skoog medium (MS) supplemented with 20 g.L-1 of sucrose without growth regulators. In this medium multiplication rate after 20 days was 7.9. Rooted plants were acclimatized successfully. (AU)

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa

Eficacia y seguridad de ranitidina 150mg vs 300 mg dos veces por día en úlcera duodenal / Effectiveness and safety of ranitidine 150 mg vs 300 mg twice a day in duodenal ulcer

Trescientos noventa y cuatro pacientes con úlcera duodenal diagnosticada endoscópica fueron randomizados para recibir ranitidina 150 mg bid o ranitidina 300 mg bid en un estudio multicéntrico, prospectivo, doble-ciego, llevado a cabo en 7 países latinoamericanos. La endoscopía a las 4 semanas mostró curación completa de las úlceras en 171 de 196 pacientes (87.2%) tratados con ranitidina 150 mg bid y 178 de 198 (89.9%) tratados con ranitidina 300 mg bid. Ambos regímenes de tratamientos fueron igualmente efectivos, reduciendo rápidamente la incidencia de los síntomas ulcerosos. Es probable que el regimen de dosis elevadas con ranitidina sea adecuado en pacientes con enfermedad ulcerosa severa (AU)

[Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]. / Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal.

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2%) treated with ranitidine 150 mg bid and 178 of 198 (89.9%) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.

Eficacia y seguridad de Ranitidina 150 mg vs 300 mg dos veces por día en ulcera duodenal. / [Effectiveness and safety of 150 mg vs 300 mg ranitidine twice a day in duodenal ulcer]

394 patients with endoscopically diagnosed duodenal ulcer were randomly allocated to treatment with ranitidine 150 bid o ranitidine 300 mg bid in a prospective double-blind multicenter trial conducted in seven LatinoAmerican countries. Endoscopy at 4 weeks showed complete ulcer healing en 171 of 196 patients (87.2

) treated with ranitidine 150 mg bid and 178 of 198 (89.9

) treated with ranitidine 300 mg bid. Both treatment regimens were equally effective at rapidly reducing the incidence of ulcer-related symptoms. It is possible that higher dosage regimen of ranitidine would be useful in patients with more severe duodenal ulcer disease.