873 resultados para Linguistica variation and change
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In this Special Issue, the focus is on contact-induced language variation and change in situations of societal bilingualism that involve long-term contact between French and another language. As is well known, when two or more languages are spoken by groups of speakers in the same geographical area, over time, features from one language can be transferred to the other language, especially when the languages in question are unequal in terms of prestige, institutional support and demographic factors. The process that leads to the adoption of such features in the contact languages is generally known as INTERFERENCE or TRANSFER, and these terms are also used to describe the features in question (i.e. the end product of the process of transfer). In this issue we prefer to use the term TRANSFER over the use of the notion INTERFERENCE, as the former has fewer negative connotations than the latter.
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The aim of this paper is to analyze, synchronically and diachronically, aspects of the Spanish impersonal se-construction that have not yet been satisfactorily accounted for in Spanish linguistics
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In this study, we investigate crosslinguistic patterns in the alternation between UM, a hesitation marker consisting of a neutral vowel followed by a final labial nasal, and UH, a hesitation marker consisting of a neutral vowel in an open syllable. Based on a quantitative analysis of a range of spoken and written corpora, we identify clear and consistent patterns of change in the use of these forms in various Germanic languages (English, Dutch, German, Norwegian, Danish, Faroese) and dialects (American English, British English), with the use of UM increasing over time relative to the use of UH. We also find that this pattern of change is generally led by women and more educated speakers. Finally, we propose a series of possible explanations for this surprising change in hesitation marker usage that is currently taking place across Germanic languages.
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This thesis investigates how the strong verb system inherited from Old English evolved in the regional dialects of Middle English (ca. 1100-1500). Old English texts preserve a relatively complex system of strong verbs, in which traditionally seven different ablaut classes are distinguished. This system becomes seriously disrupted from the Late Old English and Early Middle English periods onwards. As a result, many strong verbs die out, or have their ablaut patterns affected by sound change and morphological analogy, or transfer to the weak conjugation. In my thesis, I study the beginnings of two of these developments in two strong verb classes to find out what the evidence from Middle English regional dialects can tell us about their origins and diffusion. Chapter 2 concentrates on the strong-to-weak shift in Class III verbs, and investigates to what extent strong, mixed and weak past tense and participle forms vary in Middle English dialects, and whether the variation is more pronounced in the paradigms of specific verbs or sub-classes. Chapter 3 analyses the regional distribution of ablaut levelling in strong Class IV verbs throughout the Middle English period. The Class III and IV data for the Early Middle English period are drawn from A Linguistic Atlas of Early Middle English, and the data for the Late Middle English period from a sub-corpus of files from The Penn-Helsinki Parsed Corpus of Middle English and The Middle English Grammar Corpus. Furthermore, The English Dialect Dictionary and Grammar are consulted as an additional reference point to find out to what extent the Middle English developments are reflected in Late Modern English dialects. Finally, referring to modern insights into language variation and change and linguistic interference, Chapter 4 discusses to what extent intra- and extra-linguistc factors, such as token and type frequency, stem structure and language contact, might correlate with the strong-to-weak shift and ablaut levelling in Class III and IV verbs in the Middle English period. The thesis is accompanied by six appendices that contain further information about my distinction of Middle English dialect areas (Appendix A), historical Class III and IV verbs (B and C) and the text samples and linguistic data from the Middle English text corpora (D, E and F).
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)
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An assessment of the changes in the distribution and extent of mangroves within Moreton Bay, southeast Queensland, Australia, was carried out. Two assessment methods were evaluated: spatial and temporal pattern metrics analysis, and change detection analysis. Currently, about 15,000 ha of mangroves are present in Moreton Bay. These mangroves are important ecosystems, but are subject to disturbance from a number of sources. Over the past 25 years, there has been a loss of more than 3800 ha, as a result of natural losses and mangrove clearing (e.g. for urban and industrial development, agriculture and aquaculture). However, areas of new mangroves have become established over the same time period, offsetting these losses to create a net loss of about 200 ha. These new mangroves have mainly appeared in the southern bay region and the bay islands, particularly on the landward edge of existing mangroves. In addition, spatial patterns and species composition of mangrove patches have changed. The pattern metrics analysis provided an overview of mangrove distribution and change in the form of single metric values, while the change detection analysis gave a more detailed and spatially explicit description of change. An analysis of the effects of spatial scales on the pattern metrics indicated that they were relatively insensitive to scale at spatial resolutions less than 50 m, but that most metrics became sensitive at coarser resolutions, a finding which has implications for mapping of mangroves based on remotely sensed data. (C) 2003 Elsevier Science B.V. All rights reserved.
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Background: A family of hydrophilic acylated surface (HASP) proteins, containing extensive and variant amino acid repeats, is expressed at the plasma membrane in infective extracellular (metacyclic) and intracellular (amastigote) stages of Old World Leishmania species. While HASPs are antigenic in the host and can induce protective immune responses, the biological functions of these Leishmania-specific proteins remain unresolved. Previous genome analysis has suggested that parasites of the sub-genus Leishmania (Viannia) have lost HASP genes from their genomes. Methods/Principal Findings: We have used molecular and cellular methods to analyse HASP expression in New World Leishmania mexicana complex species and show that, unlike in L. major, these proteins are expressed predominantly following differentiation into amastigotes within macrophages. Further genome analysis has revealed that the L. (Viannia) species, L. (V.) braziliensis, does express HASP-like proteins of low amino acid similarity but with similar biochemical characteristics, from genes present on a region of chromosome 23 that is syntenic with the HASP/SHERP locus in Old World Leishmania species and the L. (L.) mexicana complex. A related gene is also present in Leptomonas seymouri and this may represent the ancestral copy of these Leishmania-genus specific sequences. The L. braziliensis HASP-like proteins (named the orthologous (o) HASPs) are predominantly expressed on the plasma membrane in amastigotes and are recognised by immune sera taken from 4 out of 6 leishmaniasis patients tested in an endemic region of Brazil. Analysis of the repetitive domains of the oHASPs has shown considerable genetic variation in parasite isolates taken from the same patients, suggesting that antigenic change may play a role in immune recognition of this protein family. Conclusions/Significance: These findings confirm that antigenic hydrophilic acylated proteins are expressed from genes in the same chromosomal region in species across the genus Leishmania. These proteins are surface-exposed on amastigotes (although L. (L.) major parasites also express HASPB on the metacyclic plasma membrane). The central repetitive domains of the HASPs are highly variant in their amino acid sequences, both within and between species, consistent with a role in immune recognition in the host.
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Genetic variation and environmental heterogeneity fundamentally shape the interactions between plants of the same species. According to the resource partitioning hypothesis, competition between neighbors intensifies as their similarity increases. Such competition may change in response to increasing supplies of limiting resources. We tested the resource partitioning hypothesis in stands of genetically identical (clone-origin) and genetically diverse (seed-origin) Eucalyptus trees with different water and nutrient supplies, using individual-based tree growth models. We found that genetic variation greatly reduced competitive interactions between neighboring trees, supporting the resource partitioning hypothesis. The importance of genetic variation for Eucalyptus growth patterns depended strongly on local stand structure and focal tree size. This suggests that spatial and temporal variation in the strength of species interactions leads to reversals in the growth rank of seed-origin and clone-origin trees. This study is one of the first to experimentally test the resource partitioning hypothesis for intergenotypic vs. intragenotypic interactions in trees. We provide evidence that variation at the level of genes, and not just species, is functionally important for driving individual and community-level processes in forested ecosystems.
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Diplomityössä tutkitaan keinoja brändätä ja varioida S60-ohjelmistoja dynaamisesti ja ajonaikaisesti. S60 on kehitysalusta, jota käyttävät useat puhelinvalmistajat ja heidän puhelimiaan käyttävät lukuisat eri operaattorit. Operaattorit haluavat puhelimiensa tai osan puhelimen sovelluksista erottuvan kilpailijoista heidän omalla brändillään ja tämän takia täytyy olla keinot joko koko puhelimen, tai valittujen sovellusten brändäykselle. Osa sovelluksista saatetaan haluta vaihtavan käytettyä brändiä sen käyttämien resurssien, kuten verkkopalvelimen, mukaan. Variointidataa tulee myös pystyä jakamaan eri sovellusten tai sovellusten osien kesken. Työssä esitellään Symbian käyttöjärjestelmä ja S60 kehitysympäristö, sekä pohditaan Symbianin turvallisuuskäytäntöjen tuomia haasteita variointidatan jakamiseen eri sovellusten välillä. Olemassaolevia variointitapoja tutkitaan työn mahdolliseksi pohjaksi. Työ sisältää esittelyn projektista, jossa kehitettiin erään S60 sovelluksen dynaaminen brändäystoteutus, joka myös mahdollistaa variointidatan jakamisen eri sovellusten kanssa.
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Chironomidae spatial distribution was investigated at 63 near-pristine sites in 22 catchments of the Iberian Mediterranean coast. We used partial redundancy analysis to study Chironomidae community responses to a number of environmental factors acting at several spatial scales. The percentage of variation explained by local factors (23.3%) was higher than that explained by geographical (8.5%) or regional factors(8%). Catchment area, longitude, pH, % siliceous rocks in the catchment, and altitude were the best predictors of Chironomidae assemblages. We used a k-means cluster analysis to classified sites into 3 major groups based on Chironomidae assemblages. These groups were explained mainly by longitudinal zonation and geographical position, and were defined as 1) siliceous headwater streams, 2) mid-altitude streams with small catchment areas, and 3) medium-sized calcareous streams. Distinct species assemblages with associated indicator taxa were established for each stream category using IndVal analysis. Species responses to previously identified key environmental variables were determined, and optima and tolerances were established by weighted average regression. Distinct ecological requirements were observed among genera and among species of the same genus. Some genera were restricted to headwater systems (e.g., Diamesa), whereas others (e.g., Eukiefferiella) had wider ecological preferences but with distinct distributions among congenerics. In the present period of climate change, optima and tolerances of species might be a useful tool to predict responses of different species to changes in significant environmental variables, such as temperature and hydrology.
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Seven crayfish species from three genera of the subfamily Cambarinae were electrophoretically examined for genetic variation at a total of twenty-six loci. Polymorphism was detected primarily at three loci: Ao-2, Lap, and Pgi. The average heterozygosities over-all loci for each species were found to be very low when compared to most other invertebrate species that have been examined electrophoretically. With the exception of Cambarus bartoni, the interpopulation genetic identities are high within any given species. The average interspecific identities are somewhat lower and the average intergeneric identities are lower still. Populations, species and genera conform to the expected taxonomic progression. The two samples of ~ bartoni show high genetic similarity at only 50 percent of the loci compared. Locus by locus identity comparisons among species yield U-shaped distributions of genetic identities. Construction of a phylogenetic dendrogram using species mean genetic distances values shows that species grouping is in agreement with morphological taxonomy with the exception of the high similarity between Orconectespropinquus and Procambarus pictus. This high similarity suggests the possibility of a regulatory change between the two species. It appears that the low heterozygosities, high interpopulation genetic identities, and taxonomic mispositioning can all be explained on the basis of low mutation rates.