1,721,046 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
The application of molecular genetic tools to examine diet and population structure in the New Zealand scampi, Metanephrops challengeri
No full textThe New Zealand scampi, Metanephrops challengeri, is an endemic commercially-prized deep sea lobster that is usually bottom trawled from water of 100 - 500 m deep. These lobsters are typically the dominant mobile megafaunal species in their deep sea benthic habitat with their burrowing behaviour playing an important role in bioturbation of the seafloor habitat. They have limited dispersal capabilities, possessing larvae with weak swimming abilities and a short pelagic duration, while the reptant juvenile/adult stages of the lifecycle are obligate burrow dwellers with limited movements, making them vulnerable to overexploitation. Despite their economic significance, relatively little is known about their ecology or the environment in which they live. The aim of this thesis was to use recent advances in next-generation sequencing and computational methods to deliver powerful new insights into the diet and population structure of the New Zealand scampi.
DNA metabarcoding was used to identify taxa from gut content of 66 scampi from four fishery management areas (FMAs). An optimized DNA metabarcoding protocol revealed more than 150 species in the gut content of this lobster species; their diet was taxonomically diverse and dominated by crabs, prawns and fish. There was a strong indication that discarded bycatch formed an important component of the diet of scampi. The dietary taxa identified can be used to guide the development of attractive baits that can be tested in baited pots and further explored for aquaculture feed development.
To investigate the population structure of the scampi around New Zealand, a combination of genotyping-by-sequencing and hydrodynamic particle modelling were used. The analyses of 91 scampi samples from five FMAs identified three genetically distinct groups that were geographically isolated around New Zealand. Hydrodynamic modelling of larval dispersal indicated directional gene flow around New Zealand, which was largely concordant with the gene flow inferred from the genomic data. The results highlight the importance of ensuring the stock sustainability of source populations. The genetic variation among FMAs provides aquaculture development a rigorous basis for selecting a genetically diverse set of wild broodstock to form the foundation of a domesticated population.
Overall, the research presented in this thesis demonstrates the effectiveness of applying emerging molecular genetic methods to revealing the biology and ecology of economically important species in otherwise difficult to study deep sea habitats
Investigating the Phylogenetic Relationships among Endemic New Zealand Anthozoans
No full textNew Zealand sea anemones have received very little taxonomic investigation. Their species diversity
has not been well characterised, the phylogenetic relationships among clades have not been examined,
and the biogeographic origins of our endemic species are largely unknown. Sea anemones do not leave
behind fossils of their structures, which have so often been used as the baselines for the relationships
between extinct taxa of other groups. Historically, the phylogenetic understanding of sea anemones was
based on morphological classification. In many other groups, morphological classifications have been
substantially revised by molecular phylogenetic studies, and many taxa erected on the basis of
morphology have been discovered to be non-monophyletic.
Gene sequences taken, from nine species sampled across 4 regions, targeted several mitochondrial and
nuclear genes which were amplified and sequenced. A concatenated alignment of each sequenced gene
was constructed using BEAST. Geographic distributions were researched and unified with each
species. BioGeoBEARS was used to estimate the biogeographic history on the dated molecular
phylogeny. No morphologically cryptic species were identified, though the most promising grouping
for morphologically cryptic species was the Oulactis muscosa, Aulactinia veratra, and Isactinia
olivacea clade, which remains consistent with other phylogenetic studies. The only evidence for a
distinctly New Zealand clade and species radiation came from Anthopleura rosea, Aulactinia veratra,
and Isactinia olivacea, as the entire clade is endemic to New Zealand and is reciprocally monophyletic.
Biogeographic analysis shows that the origins of New Zealand sea anemone has been shaped by the
dominance of dispersal from the Pacific rather than by Gondwanan vicariant connections.
New genetic sequences for endemic sea anemones were created, along with the first ever sequences for
Anthothoe vagrans and Isoparactis ferax. These sequences produced the first phylogenetic analysis of
endemic New Zealand sea anemones, showing that sea anemones colonised New Zealand multiple
times in many unique events. Final analysis indicates that the driving factor of sea anemone
biogeographic distributions may be extinction. Extant sea anemones show a far more restricted and
regional distribution than the predicted distributions of ancestral species. Therefore, the current
observed distributions are a result of localised extinction events. These localised extinction events
cause reproductive isolation, which leads to speciation. The asexual reproduction and colonisation
abilities of sea anemone may be a result of sea anemones being quite vulnerable to small scale
extinction events and genetic isolation
Investigating the Phylogenetic relationships of endemic New Zealand Anthozoans
No full textFull Text is available to authenticated members of The University of Auckland only.New Zealand sea anemones have received very little taxonomic investigation. Their species diversity
has not been well characterised, the phylogenetic relationships among clades has not been examined,
and the biogeographic origins of our endemic species are largely unknown. Sea anemones do not leave
behind fossils of their structures, which have so often been used as the baselines for the relationships
between extinct taxa of other groups. Current phylogeny of sea anemones is rooted in morphological
classification, which phylogenetic studies show are rarely monophyletic.
Gene sequences taken, from nine species sampled across 4 regions, targeted several mitochondrial and
nuclear genes which were amplified and sequenced. A concatenated tree of each sequenced gene was
constructed using BEAST. Geographic distributions were researched and unified with each species.
BioGeoBears was used to unify the geographic, phylogenetic and molecular data.
No morphologically cryptic species were identified, though the most promising grouping for
morphologically cryptic species was the Oulactis muscosa, Aulactinia veratra, and Isactinia olivacea
clade, which remains consistent with other phylogenetic studies. The only evidence for a distinctly
New Zealand clade and species radiation came from Anthopleura rosea, Aulactinia veratra, and
Isactinia olivacea, as the entire clade is endemic to New Zealand and is reciprocally monophyletic.
Biogeographic analysis shows that the origins of New Zealand sea anemone has been shaped by the
dominance of dispersal from the Pacific rather than by Gondwanan vicariant connections.
New genetic sequences for endemic sea anemones were created, along with the first ever sequences for
Anthothoe vagrans and Isoparactis ferax. These sequences produced the first phylogenetic analysis of
endemic New Zealand sea anemones, showing that sea anemones colonised New Zealand multiple
times in many unique events. Final analysis indicates that the driving factor of sea anemone
biogeographic distributions may be extinction. Extant sea anemones show a far more restricted and
regional distribution than the predicted distributions of ancestral species. Therefore, the current
observed distributions are a result of localised extinction events. These localised extinction events
cause reproductive isolation, which leads to speciation. The asexual reproduction and colonisation
abilities of sea anemone may be a result of sea anemones being quite vulnerable to small scale
extinction events and genetic isolation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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