The distribution of Fusarium species (Liseola section) and fumonisins B1, B2, and B3 (FB1, FB2, and FB3) in corn at the field stage to harvest time has been investigated. Corn samples were obtained from the 45th day after flowering to harvest stage, with 15 day intervals. A good correlation between fungal species and fumonisin contamination was observed. In particular, fumonisin contamination was higher in samples with fungal infection represented mainly by Fusarium moniliforme and Fusarium proliferatum, two well-known producers of fumonisins. Low levels of fumonisins were detected at the first and second samplings, when mainly Fusarium subglutinans, a fumonisin nonproducer species, was recorded. The three samplings after physiological maturity showed predominant F. moniliforme and F. proliferatum infection and a considerable contamination with fumonisins. In these samples the levels of FB1 averaged above 1 μg/g and FB2 and FB3 levels showed similar values but lower than FB1 values. This is the first report of fumonisins in Argentinian corn at field stages. Keywords: Fumonisins; Fusarium; corn; Argentina

No abstract

This article examines the input to Argentinian Spanish-learning children from low and middle socioeconomic status (SES). It aims to determine whether the vocabulary composition (nouns and verbs) of their input varies as a function of SES, the addressee and other contextual variables such as the type of activity and the pragmatic orientation of the utterances. Thirty children (mean: 14.3 months) and their families were audio-recorded for four hours and the middle two hours were analyzed using Computerized Language Analysis (CLAN). The nouns and verbs in child-directed speech (CDS) and overheard speech (OHS) were identified using the CLAN’s part of speech tagger MOR Morphosyntactic Analysis. Regression analyses showed effects of: (a) SES and addressee on the proportion of noun types and tokens; (b) the type of activity and the pragmatic orientation of the utterances on the proportion of nouns in CDS; (c) SES and type of activity on the proportion of entity and action-oriented utterances. These findings reveal that given the complexity of children’s home environments it is crucial to consider these social and contextual dimensions to account for the distribution of different lexical categories. How they are distributed in the input likely influences the developmental course of vocabulary acquisition.

Fifty commercial corn hybrids with different endosperm characteristics, vegetative cycle length and cross class grown in the same geographical area (Cordoba Province, Argentina) were analysed for fumonisin accumulation. All hybrids analysed showed fumonisin B(1) and B(2) contamination ranging from 185 to 27,050 ng/g for FB(1) and from 40 to 9950 ng/g for FB(2). Although most of the hybrids analysed had flint-type endosperm, two hybrids with dent-type endosperm (e.g. Prozea 10 and AX 746) showed the highest level of fumonisin (37,000 ng/g) and more FB(2) than FB(1) (FB(2)/FB(1) ratio 2.42), respectively. There was no correlation between fumonisin concentration and length of the vegetative cycle. Among 18 hybrids examined for Fusarium species contamination there was also no correlation between fumonisin contamination and the level of infection with Fusarium species (Section Liseola). Eighteen hybrids showed fumonisin levels lower than 1000 ng/g. This result suggests that there is some possibility of selecting hybrids resistant or less susceptible to fumonisin and Fusarium contamination.

A survey of 150 sunflower-seed samples was carried out to evaluate the contamination from infection with Alternaria alternata with alternariol (AOH), alternariol monomethyl ether (AME) and tenuazonic acid (TA). A high percentage of the samples was contaminated with AOH (85%), AME, (47%), and TA (65%). The average levels detected were 187 μg/kg for AOH, 194 μg/kg for AME, and 6,692, μg/kg for TA. When sunflower seeds fermented by Alternaria alternata were processed under laboratory conditions to obtain the oil and meal, different distributions of Alternaria toxins between the oil and the meal were observed: whereas AOH, AME, and TA were detected in the meal, only AME and TA were detected in the oil, and the latter in a low percentage.