1,058 research outputs found

    Prevalence of mixed genotype hepatitis C virus infections in the UK as determined by genotype‐specific PCR and deep sequencing

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    The incidence of mixed genotype hepatitis C virus infections in the UK is largely unknown. As the efficacy of direct acting antivirals is variable across different genotypes, treatment regimens are tailored to the infecting genotype, which may pose issues for the treatment of underlying genotypes within undiagnosed mixed genotype HCV infections. There is therefore a need to accurately diagnose mixed genotype infections prior to treatment. PCR-based diagnostic tools were developed to screen for the occurrence of mixed genotype infections caused by the most common UK genotypes, 1a and 3, in a cohort of 506 individuals diagnosed with either of these genotypes. The overall prevalence rate of mixed infection was 3.8% however this rate was unevenly distributed, with 6.7% of individuals diagnosed with genotype 3 harbouring genotype 1a strains and only 0.8% of samples from genotype 1a patients harbouring genotype 3 (p<0.05). Mixed infection samples consisted of a major and a minor genotype, with the latter constituting less than 21% of the total viral load and, in 67% of cases, less than 1% of the viral load. Analysis of a subset of the cohort by Illumina PCR-next generation sequencing resulted in a much greater incidence rate than obtained by PCR. This may have occurred due to the non-quantitative nature of the technique and despite the designation of false positive thresholds based on negative controls

    Family language patterns in bilingual families and relationships with children's language outcomes

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    Past research shows that family language patterns (i.e., which languages are spoken in the family and by whom) are associated with bilingual children's language use. However, it is unclear how input properties such as input quantity, parental proficiency, and language mixing may differ across family language patterns. It is also unclear whether the effects of family language patterns on children's language proficiency remain when differences in input properties are controlled. We investigated (i) which family language patterns occurred in bilingual families in the Netherlands (n = 136), (ii) whether input properties differed across patterns, and (iii) how patterns related to children's proficiency, once input properties were controlled. Home language situations were assessed through a questionnaire, children's proficiency in Dutch and the minority language through vocabulary tests and parent ratings. Three language patterns were found: one-parent-one-language, both parents mixed languages or used the minority language. The results showed differences in input properties across all patterns, as well as effects of these patterns on children's proficiency in Dutch and the minority language that disappeared once input properties were controlled. These findings do not provide robust evidence that family language patterns predict children's proficiency, but rather, that input quantity is crucial.</p

    The effects of foreign language programmes in early childhood education and care: a systematic review

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    This systematic review investigates the effects of foreign language programmes in early childhood education and care (ECEC), which are increasingly popular. Foreign language ECEC centres familiarise very young children with a foreign language, and in general also expose them to the majority language. This review synthesises research on the effects of foreign language ECEC on children’s development of the foreign language, majority language, first language, and wellbeing, as well as programme-related and child-related factors that influence language development and wellbeing. The reviewed studies indicate that foreign language ECEC fosters foreign language development, without negatively impacting the majority and first language. Children can experience positive wellbeing in these programmes, but only if programmes are play-based and if the language policy is not too strict. Some studies report that programme characteristics, such as input quantity, language policy, and teacher strategies, modulate the effects of foreign language ECEC on language development and wellbeing. Few of the reviewed studies examined child characteristics, but the available findings indicate that children’s age, as well as their temperament and in-class behaviour, are related to foreign language learning. However, these findings need to be interpreted with caution, because research into foreign language ECEC is still in its infancy

    On reducing the Heun equation to the hypergeometric equation

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    The reductions of the Heun equation to the hypergeometric equation by polynomial transformations of its independent variable are enumerated and classified. Heun-to-hypergeometric reductions are similar to classical hypergeometric identities, but the conditions for the existence of a reduction involve features of the Heun equation that the hypergeometric equation does not possess; namely, its cross-ratio and accessory parameters. The reductions include quadratic and cubic transformations, which may be performed only if the singular points of the Heun equation form a harmonic or an equianharmonic quadruple, respectively; and several higher-degree transformations. This result corrects and extends a theorem in a previous paper, which found only the quadratic transformations. [See K. Kuiken, "Heun's equation and the hypergeometric equation", SIAM Journal on Mathematical Analysis 10:3 (1979), 655-657.]Comment: 36 pages, a few additional misprints correcte
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