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Purpose: Nonnative listeners have difficulty recognizing English words due to underdeveloped acoustic-phonetic and/or lexical skills. The present study used Boothroyd and Nittrouer's (1988)j factor to tease apart these two components of word recognition. Method: Participants included 15 native English and 29 native Russian listeners. Fourteen and 15 of the Russian listeners reported English (ED) and Russian (RD) to be their dominant language, respectively. Listeners were presented 119 consonant-vowel-consonant real and nonsense words in speech-spectrum noise at +6 dB SNR. Responses were scored for word and phoneme recognition, the logarithmic quotient of which yielded j. Results: Word and phoneme recognition was comparable between native and ED listeners but poorer in RD listeners. Analysis of j indicated less effective use of lexical information in RD than in native and ED listeners. Lexical processing was strongly correlated with the length of residence in the United States. Conclusions: Language background is important for nonnative word recognition. Lexical skills can be regarded as nativelike in ED nonnative listeners. Compromised word recognition in ED listeners is unlikely a result of poor lexical processing. Performance should be interpreted with caution for listeners dominant in their first language, whose word recognition is affected by both lexical and acoustic-phonetic factors. [ABSTRACT FROM AUTHOR]

Objective: Word recognition is a basic component in a comprehensive hearing evaluation, but data are lacking for listeners speaking two languages. This study obtained such data for Russian natives in the US and analysed the data using the perceptual assimilation model (PAM) and speech learning model (SLM). Design: Listeners were randomly presented 200 NU-6 words in quiet. Listeners responded verbally and in writing. Performance was scored on words and phonemes (word-initial consonants, vowels, and word-final consonants). Study sample: Seven normal-hearing, adult monolingual English natives (NM), 16 English-dominant (ED), and 15 Russian-dominant (RD) Russian natives participated. ED and RD listeners differed significantly in their language background. Results: Consistent with the SLM, NM outperformed ED listeners and ED outperformed RD listeners, whether responses were scored on words or phonemes. NM and ED listeners shared similar phoneme error patterns, whereas RD listeners' errors had unique patterns that could be largely understood via the PAM. RD listeners had particular difficulty differentiating vowel contrasts /i-I/, /æ-ℇ/, and /ɑ-Λ/, word-initial consonant contrasts /p-h/ and /b-f/, and word-final contrasts /f-v/. Conclusions: Both first-language phonology and second-language learning history affect word and phoneme recognition. Current findings may help clinicians differentiate word recognition errors due to language background from hearing pathologies. [ABSTRACT FROM AUTHOR]

Background: The phylum Verrucomicrobia is a widespread but poorly characterized bacterial clade. Although cultivation-independent approaches detect representatives of this phylum in a wide range of environments, including soils, seawater, hot springs and human gastrointestinal tract, only few have been isolated in pure culture. We have recently reported cultivation and initial characterization of an extremely acidophilic methanotrophic member of the Verrucomicrobia, strain V4, isolated from the Hell's Gate geothermal area in New Zealand. Similar organisms were independently isolated from geothermal systems in Italy and Russia. Results: We report the complete genome sequence of strain V4, the first one from a representative of the Verrucomicrobia. Isolate V4, initially named "Methylokorus infernorum" (and recently renamed Methylacidiphilum infernorum) is an autotrophic bacterium with a streamlined genome of ∼2.3 Mbp that encodes simple signal transduction pathways and has a limited potential for regulation of gene expression. Central metabolism of M. infernorum was reconstructed almost completely and revealed highly interconnected pathways of autotrophic central metabolism and modifications of C1-utilization pathways compared to other known methylotrophs. The M. infernorum genome does not encode tubulin, which was previously discovered in bacteria of the genus Prosthecobacter, or close homologs of any other signature eukaryotic proteins. Phylogenetic analysis of ribosomal proteins and RNA polymerase subunits unequivocally supports grouping Planctomycetes, Verrucomicrobia and Chlamydiae into a single clade, the PVC superphylum, despite dramatically different gene content in members of these three groups. Comparative-genomic analysis suggests that evolution of the M. infernorum lineage involved extensive horizontal gene exchange with a variety of bacteria. The genome of M. infernorum shows apparent adaptations for existence under extremely acidic conditions including a major upward shift in the isoelectric points of proteins. Conclusion: The results of genome analysis of M. infernorum support the monophyly of the PVC superphylum. M. infernorum possesses a streamlined genome but seems to have acquired numerous genes including those for enzymes of methylotrophic pathways via horizontal gene transfer, in particular, from Proteobacteria. [ABSTRACT FROM AUTHOR]