Bacterial communities in the collection and chlorinated distribution sections of a drinking water system in Budapest, Hungary.

Bacterial communities of a bank-filtered drinking water system were investigated by aerobic cultivation and clone library analysis. Moreover, bacterial communities were compared using sequence-aided terminal restriction fragment length polymorphism (T-RFLP) fingerprinting at ten characteristic points located at both the collecting and the distributing part of the water supply system. Chemical characteristics of the samples were similar, except for the presence of chlorine residuals in the distribution system and increased total iron concentration in two of the samples. Assimilable organic carbon (AOC) concentration increased within the collection system, it was reduced by chlorination and it increased again in the distribution system. Neither fecal indicators nor pathogens were detected by standard cultivation techniques. Chlorination reduced bacterial diversity and heterotrophic plate counts. Community structures were found to be significantly different before and after chlorination: the diverse communities in wells and the collection system were dominated by chemolithotrophic (e.g., Gallionella and Nitrospira) and oligocarbophilic-heterotrophic bacteria (e.g., Sphingomonas, Sphingopyxis, and Bradyrhizobium). After chlorination in the distribution system, the most characteristic bacterium was related to the facultative methylotrophic Methylocella spp. Communities changed within the distribution system too, Mycobacterium spp. or Sphingopyxis spp. became predominant in certain samples.

Speech, language and literacy skills 3 years later: a follow-up study of early phonological and metaphonological intervention.

BACKGROUND: Three years before the present study, 19 preschool children participated in a phonological and metaphonological intervention programme. The phonological intervention programme was based on non-linear phonological analyses. The metaphonological intervention programme included both rhyming and alliteration tasks and was directly targeted during the last section of the programme. All children made significant gains in phonology, and many in metaphonology. However, the literature notes a tendency for children with history of early speech or language impairments to have difficulty acquiring literacy skills or to show residual speech impairment. The participants of the 1998 study were therefore considered at risk for continuing speech impairment and/or academic performance. AIMS: The primary objectives were to document the children's later speech, language and literacy skills, and to determine potential relationships between previous and concurrent child factors. METHODS & PROCEDURES: Twelve children from the original cohort (aged 6;1-8;5) received a comprehensive battery of speech, language, cognitive and academic tasks 3 years after the original study. Data were evaluated both concurrently and in terms of the children's preschool performance. OUTCOMES & RESULTS: Five of the children had residual phonological impairment. Only two children showed below average reading (decoding and comprehension), although five also showed below average spelling performance. Children with limitations in verbal memory, language production and metaphonology at the follow-up point were more likely to show delays in literacy. Language production skills at the follow-up point were most strongly correlated with literacy development. In terms of the early study, the strongest predictor for literacy development was performance on metaphonology tasks at the end of the early intervention study. The strongest predictor for ongoing speech impairment was phonological skill at the end of the early study. CONCLUSIONS: Results suggest that early phonological and metaphonological intervention can promote normalization of speech development and normal acquisition of literacy skills for at least some children with a history of severe phonological impairment. In the earlier study, the component structure of words (onsets, rhymes, codas) was emphasized through both metaphonological and non-linear phonological intervention. Risk for literacy and ongoing speech impairment can be reduced through early intervention that draws attention to the structure of words.