1,721,001 research outputs found
Quantifying nitrogen retention in surface flow wetlands for environmental planning at the landscape-scale
Full text linkSurface flow wetlands are valued highly for their high nutrient retention potential and their unique biodiversity. At
present, there are an increasing number of activities aimed at restoring these sites as multifunctional landscape
entities. The success of wetland restoration is however clearly dependent on the site selection to achieve the specific
restoration goals. This study first presents a tool to identify the most suitable areas for the restoration of surface flow
wetlands for water quality improvement in a given catchment and secondly compares three different mathematical
equations in order to quantify the effect of nitrogen retention when restoring the previously selected, most suitable
wetland sites. For site selection, a score system was developed which is linked to a Geographical Information System.
The score system combines information from a given catchment in eight data layers including soil substrate, actual
land use, relief features, hierarchical drainage basin classification, river proximity and socio-economic factors. The
score system was applied to a potential use situation in the Neuwu ̈hrener Au watershed (40 km2) in northern
Germany belonging to the Baltic Sea drainage basin. Three areas were identified as most suitable for the restoration
of surface flow wetlands. Their potential effect on nitrogen retention was evaluated using three different equations:
(I) a linear relation between wetland load and a wetland; (II) an exponential equation between wetland load and
wetland area; and (III) an exponential equation between wetland load and hydraulic retention time. The linear
approach calculates increasing wetland retention with increasing upstream catchment area and appears to overestimate
nitrogen retention in wetlands located more downstream. The two exponential equations calculated nitrogen
retention in the three wetlands in the same order of magnitude. The results from the siting procedure and the
prediction of nitrogen removal rates are useful for decision makers in wetland planning to base their decision on best
available data and knowledge. The model comparison allows the incorporation of uncertainty in the decision progress
which is seen as a necessary requirement when quantifying biological processes in environmental planning. © 2002
Elsevier Science B.V. All rights reserved
A GIS-based score system for siting and sizing of created or restored wetlands: Two case studies
Full text linkWater bodies are impacted by watershed loads in terms of nutrients and xenobiotics.
This impact impairs the designated uses of the water body. Often preventive actions and end-of-pipe
treatments do not reach the acceptable load to ensure the water quality standard in the water body.
Wetlands are suitable tools for improving the self-purification capacity of a water system and can be
used as a tool to reduce pollutant loads in a river network. This paper presents a methodology for
the Siting and Sizing of created or restored wetlands at the watershed level, based on Geographical
Information Systems (GIS) technique and estimations of wetland required area. The final outputs of
the methodology are a Land Score System for Siting and a first rough estimation for the Sizing. The
combination of these two elements is expected to be useful as a planning tool for watershed management
and wetland planning. In order to assess the reliability of the procedure two very different
case-studies are considered
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
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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