Mycotoxins in maize grains grown in organic and conventional agriculture

Maize is traditionally used for bakery in several countries, and autochthonous varieties are increasingly demanded particularly for organic agriculture, but one of the dangers of cereal consumption is mycotoxin contamination. Mycotoxins are dangerous for health and might be present in any grain depending on genotypes and environments. In the present work we assess the natural levels of fumonisin and deoxynivalenol (DON) contaminations in nine diverse open-pollinated maize varieties grown in four different locations, under organic or conventional conditions, in two regions from the humid Spain during two years. Differences were significant among locations and among varieties for fumonisin contamination but not for DON content. Locations were the main environmental source of variation affecting fumonisins while DON was more affected by years. The Basque locations had more fumonisin than the Galician locations, but there were no differences between organic and conventional environments. Fumonisin contamination was more variable than DON among locations and among varieties. Fumonisin and DON were highly correlated on average but correlations were low for each particular environment. Mean fumonisin and DON were below the threshold allowed by the EU, but the white-kernel medium late variety Rebordanes(P)C2 had more than 4.00mg/kg of fumonisin in one location, while the early yellow variety Sarreaus had the lowest contamination. We conclude warning producers of the danger of natural contamination with mycotoxins for some varieties in specific environments.Research was supported by the Spanish Plan for Research and Development (project code AGL2010-22254, AGL2009-12770), the Basque Government, and the Diputación Provincial de Pontevedra.MICINNDiputación de PontevedraPeer Reviewe

Mejora de maíz para agricultura ecológica y convencional

Esta investigación ha sido financiada por el Plan Nacional de I+D+I (proyectos AGL2010-22254 y AGL2013-48852), el CSIC y el Gobierno VascoPeer reviewe

La presencia azteca en Oaxaca: la provincia de Coixtlahuaca

En 1948 Ignacio Bernal realizó excavaciones en Coixtlahuaca para verificar la idea de que este sitio hubiera sido el más importante para la Triple Alianza para hacerse de bie-nes de lujo procedentes de la Mixteca Alta. Sin embargo, sus excavaciones demostraron que el material azteca recolectado en el sitio de Inguiteria, capital de Coixtlahuaca, representaba menos del 0.4 % del total recolectado en el lugar, lo cual puso en duda\ua0 que fuera el lugar más importante del imperio para hacerse de estos bienes. Este nuevo proyecto, realizado 60 años después, combinando la etnohistoria del siglo xvi , métodos no destructivos de estudio de la superficie y excavaciones científicas, intenta aportar nuevos datos sobre la presencia azteca en esta provincia. En el presente artículo pretendemos dar contestación a algunas preguntas aportando detalles nuevos y actualizando algunos puntos, pero como se puede apreciar, las conclusiones de Bernal todavía son válidas, y al final, todo parece indicar que los instrumentos de control como la fuerza de armas y las ejecuciones resultaron crudos, efímeros e insuficientes frente a una extensa masa demográfica y una economía tan desarrollada como la de Coixtlahuaca en particular y de Oaxaca en general

Evidence of human occupation in Mexico around the Last Glacial Maximum.

The initial colonization of the Americas remains a highly debated topic1, and the exact timing of the first arrivals is unknown. The earliest archaeological record of Mexico-which holds a key geographical position in the Americas-is poorly known and understudied. Historically, the region has remained on the periphery of research focused on the first American populations2. However, recent investigations provide reliable evidence of a human presence in the northwest region of Mexico3,4, the Chiapas Highlands5, Central Mexico6 and the Caribbean coast7-9 during the Late Pleistocene and Early Holocene epochs. Here we present results of recent excavations at Chiquihuite Cave-a high-altitude site in central-northern Mexico-that corroborate previous findings in the Americas10-17of cultural evidence that dates to the Last Glacial Maximum (26,500-19,000 years ago)18, and which push back dates for human dispersal to the region possibly as early as 33,000-31,000 years ago. The site yielded about 1,900 stone artefacts within a 3-m-deep stratified sequence, revealing a previously unknown lithic industry that underwent only minor changes over millennia. More than 50 radiocarbon and luminescence dates provide chronological control, and genetic, palaeoenvironmental and chemical data document the changing environments in which the occupants lived. Our results provide new evidence for the antiquity of humans in the Americas, illustrate the cultural diversity of the earliest dispersal groups (which predate those of the Clovis culture) and open new directions of research