Schooling duration rather than chronological age predicts working memory between 6 and 7 years: memory maestros study

OBJECTIVE: Low working memory (WM) is strongly linked with poor academic outcomes. WM capacity increases across childhood but how exposure to school is associated with WM development is not known. We aimed to determine extent to which chronological age and schooling duration are associated with WM at the population level. METHODS: In 2012, children in Grade 1 (the second year of formal schooling in Victoria, Australia) from 44 schools in metropolitan Melbourne were recruited. Assessments occurred over the entire school year, with schools quasi-randomly allocated to one of the 4 school terms. WM (primary outcome) was measured using 2 subtests from the computerized Automated Working Memory Assessment: Backwards Digit Recall (verbal) and Mister X (visuospatial). Linear regression was used to examine relationships of WM with time in school and age. RESULTS: Of the 1765 who provided consent, 1727 children (97.9%) had WM assessed throughout the 2012 school year. WM scores became steadily higher over the course of the year. Thus, scores were .77 and .53 SDs higher in Term 4 than Term 1 for verbal and visuospatial WM, respectively (p values for trend for both scores <.001); conclusions were unchanged when adjusted for age and potential confounders. Conversely, age associations attenuated fully once adjusted for school duration. CONCLUSIONS: Our results demonstrate, for the first time, that the developmental increases in WM are strongly associated with time spent in the classroom, above and beyond chronological age.

Separation of flavonoids and naphthopyrones from four Brazilian Paepalanthus species by droplet countercurrent chromatography

A general procedure was developed for the simultaneous separation of flavonoids and naphthopyrones from the polar extracts of the capitula from Brazilian everlasting plants is described. The ethanolic extracts of several species from the Paepalanthus genus (Eriocaulaceae) were fractionated by droplet countercurrent chromatography followed by column chromatography on pvp and sephadex LH-20. The isolated compounds were identified by spectrometric analysis and comparison with literature data. This approach led to the isolation of 9-O-β-D-glucopyranosylpaepalantine (1), 9-O-β-D-glucopyranosyl (1→6)allopyranosylpaepalantine (2), along with the flavonoids 6-methoxykaempferol (3), 3-O-β-D-glucopyranosyl-6-methoxykaempferol (4), patuletin (5), 3-Oβ-D-rutinosylpatuletin (6), 7-O-β-D-glucopyranosylquercetagetin (7), 5,7,4'-trihydroxy-6,3'-dimethoxyflavone (8) and 5,7,4'-trihydroxy-6,3'-dimethoxyflavonol (9).

Políticas para la agricultura en América Latina y el Caribe: competitividad, sostenibilidad e inclusión social. Memoria del seminario internacional sobre políticas agrícolas en América Latina y el Caribe, realizado en Santiago los días 6 y 7 de diciembre de 2011 ]

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Informe de la primera reunión de los puntos focales designados por los gobiernos de los países signatarios de la declaración sobre la aplicación del principio 10 de la Declaración de Río sobre el medio ambiente y el desarrollo en América Latina y el Caribe, Santiago, 6 y 7 de noviembre de 2012

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Report of the first meeting of the focal points appointed by the governments of the signatory countries of the declaration on the application of principle 10 of the Rio Declaration on Environment and Development in Latin America and the Caribbean, Santiago, 6 and 7 November 2012

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ANTI-TRYPANOSOMAL ACTIVITY OF 1,2,3,4,6-PENTA-O-GALLOYL-beta-D-GLUCOSE ISOLATED FROM Plectranthus barbatus Andrews (Lamiaceae)

MeOH extract from the leaves of Plectranthus barbatus Andrews (Lamiaceae), showed in vitro anti-trypanosomal activity. The bioassay-guided fractionation resulted in the isolation of a gallic acid derivative, identified as 1,2,3,4,6-penta-O-galloyl-beta-D-glucose (PGG), after thorough NMR and MS spectral analysis. Finally, this compound was tested against trypomastigote forms of T. cruzi and displayed an EC50 value of 67 mu M, at least 6.6-fold more effective than the standard drug benznidazole. This is the first occurrence of PGG in the Plectranthus genus and the first anti-parasitic activity described for PGG in the literature.