1,721,077 research outputs found
Long-Term Trends and Variability of North Atlantic Phytoplankton Populations
No full textMarine phytoplankton are microscopic in size, but have substantial roles in the marine environment, structuring the base of the marine food web and facilitating marine biogeochemical cycles. Changes to their community therefore have important consequences on the functioning of marine ecosystem services. This thesis, describes long-term variability in the phytoplankton community at a taxonomic scale resolution over the North Atlantic region, using in-situ data from the Continuous Plankton Recorder (CPR) survey and output from the MIT Integrated Global Systems Model (IGSM).An innovative approach assesses the stability and disorder of the phytoplankton community in the North-East Atlantic using the CPR survey. Phytoplankton were found to return to its original structure after a period dominated by two diatom species, indicating its resilience to perturbation. Changes were not significantly linked to the physical environment, however, the results from novel approach emphasise that a rigid community structure may make the plankton population more prone to collapse under the extreme changes of a future climate. Generalised additive models (GAMS) were employed in a unique attempt to demonstrate the importance of multiple driving mechanisms. While phytoplankton continued to show very few links to the physical environment, zooplankton had a positive relationship with phytoplankton throughout the North Atlantic and had a strong negative response to deeper mixed layers and colder temperatures. It was concluded that a traditional bottom-up approach is an over simplification at inter-annual scales and future analysis should reflect this. In a final analysis, the MIT IGSM is used to explore the variability of hytoplankton in the 21st century under the pressures of increasing CO2 and global climate change. Analysis demonstrated a regional decline in biomass, with 94% of the North Atlantic demonstrating significant change. Change-point analysis shows abrupt shifts in biomass and richness occurred earlier in the sub-tropical regions (2030s) than the higher latitudes (2050s) and functional analysis showed these changes would result in a shift to smaller phytoplankton types in the higher latitudes. This study highlights the importance of maintaining spatially and temporally extensive datasets in the assessment of marine phytoplankton ecology. It highlights the potential impact of future changes to the marine environment, and the consequences this will have on the phytoplankton communities while reflecting on the broader implications this may have on the wider marine ecosystem.<br/
Questioning the grade: understanding the complexity of student grade enquiries in higher education
No full textThis thesis investigates the perceptions and attitudes of undergraduates and academics towards grading within one UK university. It explores requests for grade uplift by investigating actual, perceived and anticipated student demands in an increasingly market-driven higher education sector.The phenomenon of ‘grade grubbing’, whereby students demand an uplift of their grades, has been identified as a symbol of marketisation and the student-ascustomer. There has been little formal research on this topic, however, particularly in a UK context although there is more discussion about grade grubbing in the US.A mixed methods approach involving the use of questionnaires, focus groups, interviews and concept mapping was used, together with an extensive literature review of marketisation as a key concept, in order to gather empirical evidence about attitudes to grade appeals. The perspectives of undergraduate students and academic staff were sought and compared.The key finding is that forms of student behaviour labelled as grade grubbing have been over-simplified and misunderstood. Whilst the student voice indicates a consumerist attitude towards the student experience, grade grubbing itself, when defined as seeking an uplift in the initial grade awarded, is rare. Students are much more likely to accept the grades they receive at face value and not question them (grade neutral) or seek more feedback to understand the grade awarded (grade enquiry). They also, less commonly, challenge academic judgment (grade challenge) or demand a higher grade (grade grubbing).Whilst there are no short cuts to minimising grade enquiries, a review of the landscape affords a more fine-grained understanding of this phenomenon which should be known, less pejoratively, as grade enquiry. The study concludes with future research recommendations to inform university policy
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Variations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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