Bilingual first language acquisition: the nature of the weak language and the role of the input

This thesis investigates the development of the weak language in early bilingual language acquisition and its results are based on longitudinal and experimental data from 4 Italian-English bilingual children and their parents. The purpose of this thesis is twofold: firstly, to present a new method to assess weak language development and the role of the input in bilingual first language acquisition; secondly, to determine whether there is a relationship between input, weak language development and the acquisition of new information structure. The factors included in the analysis of the weak language are rate of acquisition, production of target-deviant forms, vocabulary, MLU and discourse pragmatics. The results are summarised in the Weak Language Scale. The results are further tested by examining longitudinal and experimental data which are used to test the hypothesis that children who develop Italian as a weak language have difficulty processing subject inversion structures, which require a high processing load due to the interface between syntax and pragmatics. The results of the Weak Language Scale are then compared to those of the Input Scale, which represents the amount of qualitative and quantitative input each child has been exposed to. The final results show that the input plays a major role in bilingual first language acquisition and it has an effect on weak language development. The findings also suggest that linguistic properties at the interface between syntax and pragmatics are harder to process for children who develop Italian as a weak language

Diatom communities and ecological status classification in the upper Po River basin

One of the main challenges in river management is the setting of nutrient thresholds that support good ecological status, which is the main objective to achieve for the European member states. This is a complex process, which needs an accurate analysis of the data collected so far for the ecological classification of rivers belonging to different typologies. We analysed the data of the multiannual monitoring concerning diatoms and nutrients in the upper Po River (NW Italy) with the aim of exploring the response of diatom community in terms of species composition, ecological guilds and indices. We considered data of 390 samples, of which 2/3 belonging to the “Central macrotype” (i.e. lowland stretches) and 1/3 to “Alpine siliceous”. We performed a Principal Coordinate Analysis to detect community patterns with respect to water chemical classification and macrotypes highlighting species and ecological guilds characteristic of samples along a water quality gradient. We then performed a partial RDA to focus on the role of environmental and spatial factors in shaping the diatom community in each of the two macrotypes. Finally, we investigated the concordance between the Italian normative indices ICMi (for diatoms) and LIMECO (a chemical index of water quality). We found significant differences in the diatom communities of the two macrotypes and in their response to water quality and to spatial factors. Communities resulted as much more uniform in sites with a low water quality, with characteristic species such as Navicula gregaria, Nitzschia palea and Sellaphora nigri. On the other hands, moderately disturbed sites (in terms of trophic level) were characterised by the highest guild diversity. The RDA confirmed the importance of spatial factors in shaping the diatom assemblages, especially in Alpine streams where the physical barriers may condition species dispersion. The comparison between the two normative indices highlights that the correspondence in the classification is achieved in the 57% (Alpine macrotype) and 43% (Central macrotype) of samples. According to our findings, we suggest the revision of the ICMi, both class boundaries and reference value. In addition, we recommend to lower LIMECO threshold for total phosphorus: indeed, several studies have shown significant changes in the diatom community composition starting from very low values (below the current LIMECO threshold, i.e. 50 µgL-1). Moreover, the extension of our study to the whole Po River basin will complete our knowledge of species not yet included in the diatom indices and of the community response to nutrient levels also in other macrotypes

Managing heritage language development:Opportunities and challenges for Chinese, Italian and Pakistani Urdu-speaking families in the UK

Abstract Drawing on theories of family language policy and literacy environment, this inquiry explores and describes how family language policy is managed through literacy resources and literacy related activities in transnational families in the UK. A total of 66 families, each with at least one child between the age of 2 and 8, participated in this study. All children spoke English alongside their heritage/home language (HL), either Chinese, Italian, or Urdu. Data sources include: (a) a questionnaire about the children’s general background and the parents’ socio-economic and cultural capital and language practice in English and HL; (b) literacy resources and activities in both HL and English; (c) interview with parents. The results of this study show some interesting differences among Italian, Urdu and Chinese speakers, not only in their family language practices, but also in their attitudes towards mother tongue literacy and application of literacy practices in the home language. Although parental language management efforts were motivated by their aspirations to enrich their children’s language repertoires, the different degrees of variation in family language input indicate that sociocultural and socio-political realities present difficulties and constraints that prevent families from developing literacy in the home language.</jats:p

Association of the mtDNA m.4171C>A/MT-ND1 mutation with both optic neuropathy and bilateral brainstem lesions

Background: An increasing number of mitochondrial DNA (mtDNA) mutations, mainly in complex I genes, have been associated with variably overlapping phenotypes of Leber’s hereditary optic neuropathy (LHON), mitochondrial encephalomyopathy with stroke-like episodes (MELAS) and Leigh syndrome (LS). We here describe the first case in which the m.4171C>A/MT-ND1 mutation, previously reported only in association with LHON, leads also to a Leigh-like phenotype. Case presentation: A 16-year-old male suffered subacute visual loss and recurrent vomiting and vertigo associated with bilateral brainstem lesions affecting the vestibular nuclei. His mother and one sister also presented subacute visual loss compatible with LHON. Sequencing of the entire mtDNA revealed the homoplasmic m.4171C>A/MT-ND1 mutation, previously associated with pure LHON, on a haplogroup H background. Three additional non-synonymous homoplasmic transitions affecting ND2 (m.4705T>C/MT-ND2 and m.5263C>T/MT-ND2) and ND6 (m.14180T>C/MT-ND6) subunits, well recognized as polymorphisms in other mtDNA haplogroups but never found on the haplogroup H background, were also present. Conclusion: This case widens the phenotypic expression of the rare m.4171C>A/MT-ND1 LHON mutation, which may also lead to Leigh-like brainstem lesions, and indicates that the co-occurrence of other ND non-synonymous variants, found outside of their usual mtDNA backgrounds, may have increased the pathogenic potential of the primary LHON mutation