1,720,992 research outputs found
The long-term recovery of the bioindicator species Nucella lapillus from tributyltin pollution
No full textIn an attempt to control marine biofouling, a co-polymer paint system was developed containing the biocide tributyltin (TBT) in the 1960s. TBT was found to be highly toxic to non-target organisms, particularly to female common dogwhelk (Nucella lapillus) in the UK. TBT blocks hormone conversion of testosterone to oestradiol, resulting in the development of a penis and vas deferens (imposex). Females die as male sex organs overgrow the oviduct, leaving them unable to deposit eggs and so suffer internal rupture. The toxicity of TBT led to legislation controlling its use from the mid 1980s and the intention for a total ban by 2008. Long-term monitoring of N. lapillus populations in Plymouth, UK south coast and Isle of Wight has showed recovery from TBT effects since the 1980s, although imposex in some populations has recently increased. Imposex has reduced at sites directly affected by shipping and population recovery has been seen at some sites from where N. lapillus had previously been absent. At some sites close to spoil dumping grounds, imposex has risen and may have been adversely affected by TBT associated with dredged harbour sediments. At some south coast sites N. lapillus population fluctuations reflected barnacle abundance, highlighting the uncertainty associated with elucidation of cause-effect relationships. Recovery from TBT impacts through recolonisation and colonisation at some sites has been achieved despite N. lapillus’ lack of a pelagic stage. Study of man-made groynes at Highcliffe, Dorset, indicated that recruitment may occur due to passive transport from inshore subtidal populations. Reintroduction trials at a formerly occupied site showed that N. lapillus were robust enough to survive translocation, but TBT levels prevented re-establishment of a viable population through severe imposex effects. Passive transport may facilitate the use of artificial sites with viable habitat and tolerable TBT levels as stepping-stones for recolonisation of isolated sites that have suffered local extinction.</p
Report on the archaeological potential of two sites located on the route of the A6 bypass at Great Glen, Leicestershire
No full textSoil Survey work was undertaken at two sites designated by the University of Birmingham Field Archaeology Unit within Fields 20b and 16 along the route of the forthcoming A6 Great Glen Bypass. Two transects, each containing 5 cores, were sampled using a Dutch-pattern soil gouge auger. Sediments were described using the standard Tröels-Smith system of sediment classification and Munsell soil colour charts. Results suggest that Field 20b has remained relatively undisturbed since the abandonment of ridge and furrow farming. Sediments adjacent to Burton Brook yielded charcoal, which may be local but could also have been transported some distance by floodwaters. In marked contrast, Field 16 appears to have been heavily engineered as part of a flood defence scheme on the River Sense in Great Glen village. Sediment samples from this field were a rather uniform mixture of clays, silts and sands. These may have been dredged from the channel or the pond and re-deposited across the field. There was no evidence of palaeosols or other significant organic deposits in the cores from either transect
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
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
Research, policy and practice for the conservation and sustainable use of intertidal mudflats and saltmarshes in the Solent from 1800 to 2016
No full textImprovements in both knowledge and actions are required to realize the conservation and sustainable use of intertidal mudflats and saltmarshes in the UK, specifically in terms of decision-making. The research presented in this paper constructed a timeline of events pertaining to the conservation and sustainable use of intertidal mudflats and saltmarshes in the Solent from the perspective of those involved, in order to establish what is actually happening, why, how, and by who. The evidence demonstrates an abundance of research and consultation for legislation and policy development purposes, with a relative lack of practice to actively conserve and sustainably use intertidal mudflats and saltmarshes. The majority of the events identified in this study indirectly influenced the conservation and sustainable use of intertidal mudflats and saltmarshes, and were primarily concerned with some other purpose, such as coastal flooding and erosion risk management, and dock development. Research, legislation and policy, and practice are interconnected in a complex web, with changes in one domain being reflected in another. Yet despite the significant investment in research and consultation processes by many people over numerous years, no clear end point appears to have been reached in terms of realizing intertidal mudflat and saltmarsh conservation and sustainable use. Based on the findings of this study, it is imperative that further in-depth studies be undertaken in order to identify and evaluate changes to improve the decision-making process through which more informed, timely decisions and more effective, concerted actions to conserve and sustainably use intertidal mudflats and saltmarshes can be taken. The concepts and methods applied in this study are transferable to other complex decision-making situations in the UK and elsewher
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