title: Long-term isolation and recent range expansion from glacial refugia revealed for the endemic springtail Gomphiocephalus hodgsoni from Victoria Land, Antarctica

authors: Stevens, Mark I.

subjects: allozymes

abstract: We examined the phylogeography of the endemic Antarctic collembolan Gomphiocephalus hodgsoni using allozymes and mitochondrial DNA (mtDNA; COI) to determine if potentially limited dispersal and long-term habitat fragmentation have promoted regional genetic differentiation. Allozyme analyses showed that differentiation among 21 populations within the Ross Dependency was high (FST = 0.55) with two main groups each representing a distinct geographical region: (1) Ross Island and Beaufort Island; and (2) all continental sites. Ross Island populations showed low levels of differentiation (FST = 0.05) and no correlation with geographical distance, suggesting their derivation from a single glacial refuge. By contrast, continental regions revealed moderate levels of differentiation (FST = 0.27) and a strong correlation with geographical distance, indicating a much older history with several refugia likely. Two sympatric allozyme genotypes were found at three continental sites from Taylor Valley and were congruent with two mtDNA haplotypes, implying nonrandom breeding groups. Although haplotype sharing between one Ross Island site (Cape Bird) and one continental site (Granite Harbour) was identified, the clades showed mostly fragmented allopatric distributions. The extensive Pleistocene glaciations, in conjunction with limited dispersal opportunities, appear to have promoted isolation and divergence among the fragmented habitats. Furthermore, the McMurdo Sound appears to be an effective isolating barrier to dispersal. However, we suggest that the unaided dispersal capacity of G. hodgsoni is unlikely to account for the limited mixing of haplotypes across the McMurdo Sound and recent human- or bird-mediated dispersal is highly probable.

text: Long-term isolation and recent range expansion from glacial refugia revealed for the endemic springtail Gomphiocephalus hodgsoni from Victoria Land, Antarctica We examined the phylogeography of the endemic Antarctic collembolan Gomphiocephalus hodgsoni using allozymes and mitochondrial DNA (mtDNA; COI) to determine if potentially limited dispersal and long-term habitat fragmentation have promoted regional genetic differentiation. Allozyme analyses showed that differentiation among 21 populations within the Ross Dependency was high (FST = 0.55) with two main groups each representing a distinct geographical region: (1) Ross Island and Beaufort Island; and (2) all continental sites. Ross Island populations showed low levels of differentiation (FST = 0.05) and no correlation with geographical distance, suggesting their derivation from a single glacial refuge. By contrast, continental regions revealed moderate levels of differentiation (FST = 0.27) and a strong correlation with geographical distance, indicating a much older history with several refugia likely. Two sympatric allozyme genotypes were found at three continental sites from Taylor Valley and were congruent with two mtDNA haplotypes, implying nonrandom breeding groups. Although haplotype sharing between one Ross Island site (Cape Bird) and one continental site (Granite Harbour) was identified, the clades showed mostly fragmented allopatric distributions. The extensive Pleistocene glaciations, in conjunction with limited dispersal opportunities, appear to have promoted isolation and divergence among the fragmented habitats. Furthermore, the McMurdo Sound appears to be an effective isolating barrier to dispersal. However, we suggest that the unaided dispersal capacity of G. hodgsoni is unlikely to account for the limited mixing of haplotypes across the McMurdo Sound and recent human- or bird-mediated dispersal is highly probable.

year: 2010

title: Editorial to the special issue on JCDL 2022

authors: Mayr, P

subjects: classification

abstract: This special issue features the selected works of authors who have presented papers at the 2022 iteration of the Joint Conference on Digital Libraries (JCDL) in Cologne, Germany. The motto of the conference was “Bridging Worlds” and was run as a fully hybrid event. Ten papers covering all aspects of Digital Libraries, namely Natural Language Processing, Information Retrieval, User Behavior, Scholarly Communication, Classification, Information Extraction are included in this issue.

text: Editorial to the special issue on JCDL 2022 This special issue features the selected works of authors who have presented papers at the 2022 iteration of the Joint Conference on Digital Libraries (JCDL) in Cologne, Germany. The motto of the conference was “Bridging Worlds” and was run as a fully hybrid event. Ten papers covering all aspects of Digital Libraries, namely Natural Language Processing, Information Retrieval, User Behavior, Scholarly Communication, Classification, Information Extraction are included in this issue.

year: 2024

title: No explanation required: Entrenchment and perception of Māori loanwords in a diachronic newspaper corpus of New Zealand English

authors: Levendis, Katharine Joy

subjects: New Zealand English

abstract: Māori loanwords are uncontestably the most notable feature of New Zealand English (Gordon, 2005; Macalister, 2006b). Although frequencies of Māori loanwords are reported to be increasing in recent years (Macalister, 2006b), and analyses strongly indicate a skew in loanwords across certain topics (Davies & Maclagan, 2006; de Bres, 2006), no studies have yet addressed whether Māori loanword behaviour differs in a corpus restricted to a single topic (with the exception of Calude, Miller, Harper, & Whaanga, Forthcoming). Nor has a thorough diachronic analysis been made on the subject since Davies and Maclagan (2006) and Macalister (2006b). This thesis is concerned with frequency of use and perception of Māori loanwords in a diachronic corpus restricted to a singular theme: te Wiki o te Reo Māori, Māori Language Week. Using a quantitative methodology in a corpus constructed from New Zealand regional and national newspaper articles spanning 2008-2017, average Māori loanword frequencies are found to be almost 5 times that of the most recent comparable diachronic study (Macalister, 2006b), and demonstrate a statistically significant diachronic increase in use. In contrast, the markedness (or translation) of Māori loanwords shows a statistically significant decreasing diachronic trend over the 10-year period. However, practice of marking appears to be affected by user perceptions and intention to educate, and therefore cannot be relied upon as a gauge of loanword entrenchment. Other conventional measures of loanword entrenchment such as frequency, listedness and morphological assimilation are also shown to be unreliable when considered independently from one another, and in cases such as that of New Zealand English where a change from above influenced by social and cultural factors (Māori loanwords functioning as an expression of political attitude and stance) appears to be interfering in loanword use. Measurement of Māori loanword entrenchment cannot be made using the same criteria as loanwords from non-threatened languages, and suggestions are made for the revised criteria for studying loanword entrenchment which takes into account the sociolinguistic context in which the loanwords are used.

text: No explanation required: Entrenchment and perception of Māori loanwords in a diachronic newspaper corpus of New Zealand English Māori loanwords are uncontestably the most notable feature of New Zealand English (Gordon, 2005; Macalister, 2006b). Although frequencies of Māori loanwords are reported to be increasing in recent years (Macalister, 2006b), and analyses strongly indicate a skew in loanwords across certain topics (Davies & Maclagan, 2006; de Bres, 2006), no studies have yet addressed whether Māori loanword behaviour differs in a corpus restricted to a single topic (with the exception of Calude, Miller, Harper, & Whaanga, Forthcoming). Nor has a thorough diachronic analysis been made on the subject since Davies and Maclagan (2006) and Macalister (2006b). This thesis is concerned with frequency of use and perception of Māori loanwords in a diachronic corpus restricted to a singular theme: te Wiki o te Reo Māori, Māori Language Week. Using a quantitative methodology in a corpus constructed from New Zealand regional and national newspaper articles spanning 2008-2017, average Māori loanword frequencies are found to be almost 5 times that of the most recent comparable diachronic study (Macalister, 2006b), and demonstrate a statistically significant diachronic increase in use. In contrast, the markedness (or translation) of Māori loanwords shows a statistically significant decreasing diachronic trend over the 10-year period. However, practice of marking appears to be affected by user perceptions and intention to educate, and therefore cannot be relied upon as a gauge of loanword entrenchment. Other conventional measures of loanword entrenchment such as frequency, listedness and morphological assimilation are also shown to be unreliable when considered independently from one another, and in cases such as that of New Zealand English where a change from above influenced by social and cultural factors (Māori loanwords functioning as an expression of political attitude and stance) appears to be interfering in loanword use. Measurement of Māori loanword entrenchment cannot be made using the same criteria as loanwords from non-threatened languages, and suggestions are made for the revised criteria for studying loanword entrenchment which takes into account the sociolinguistic context in which the loanwords are used.

year: 2018