1,720,996 research outputs found
Assessing the ecological effects of hydromorphological pressures on European lakes
Get PDFIn European countries, hydromorphological (HyMo) pressures are the second most commonly occurring types of pressures on aquatic ecosystems (after eutrophication). HyMo pressures (i.e., man-made alterations to the hydrology and morphometry of aquatic ecosystems) impact the functioning of lakes and rivers in multiple ways. Initially, they have profound effects on littoral communities, such as macrophytes, benthic invertebrates, and fish. Ultimately, they result in pervasive alteration of whole-lake ecosystems. Extensive efforts have been devoted to the development of ecological assessment methods and management measures focusing mainly on eutrophication, whereas HyMo alterations are less understood and not properly addressed. We attempted to clarify the conceptual background, to highlight achievements in method development, including pressure–response relationships and metrics used in assessment, and to underscore issues requiring urgent attention. We concluded that the currently used biological methods do not reliably address HyMo alterations. The need to develop specifically responding biological and HyMo assessment methods and to measure the necessary variables in routine monitoring programs is urgent. This review paper also serves as an introductory article to a small special series of papers on the ecological impacts of water level fluctuations. Papers in this series include an updated literature review on the ecological effects of water level fluctuations on lake macroinvertebrates, a review article specifically devoted to water level fluctuations indicators in the littoral of natural and artificial lakes, and a paper addressing the relationships between water level fluctuation alteration and spatial and temporal patterns of cladoceran communities in a dammed lake
Benthic algal assessment of ecological status in European lakes and rivers: Challenges and opportunities
No full textThis opinion paper introduces a special series of articles dedicated to freshwater benthic algae and their use in assessments and monitoring. This special series was inspired by talks presented at the 9th International Congress on the Use of Algae for Monitoring Rivers and Comparable Habitats (Trento, Italy, 2015), the latest of a series of meetings started in 1991. We believe that applied-ecology studies during the whole period covered by these meetings clearly show that monitoring and assessment makes sense only if these are embedded within a broader process of management.
In this paper, we will first provide a brief overview of phytobenthos methods in Europe. Then, we will turn toward the 'dark side' of phytobenthos and describe four particular problems for phytobenthos assessment in the European Union: (1) reliance on a single group of algae (mostly diatoms) to the exclusion of other groups; (2) relatively low adoption of benthic algae for ecological assessments in lakes; (3) absence of measures of abundances; (4) the approaches used to define boundaries between ecological classes. Lastly, we describe three general challenges of phytobenthos assessment: use of phytobenthos as a diagnostic and communication tool and linking phytobenthos assessment to the provision of ecosystem services.
The papers in the special series allow a comparison with the situation and approaches in the USA, present new methods for the assessment of ecological status and acidification, provide tools for an improved management of petrifying springs and headwaters, discuss the potential of genetic fingerprinting for ecological assessments, assess the utility of beta diversity, ecological metabarcoding and guilds, and report on the impacts of herbicides and on invasive algal speciesJRC.D.2 - Water and Marine Resource
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
Ecological and conservation value of small standing-water ecosystems: A systematic review of current knowledge and future challenges
Get PDFA small standing-water ecosystem (SWE) is a shallow (<20 m) lentic water body with a surface of a few hectares (<= 10 ha). Compared to larger counterparts, they exhibit wider ecotones, sometimes even equaling their whole surface, which maximizes structural heterogeneity, supporting exceptionally high biodiversity, metabolic rates, and functionality. Surprisingly, no binding regulations support global strategies for SWE conservation. This work consists of a literature review performed for the period 2004-2018 to assess the ecological and conservation value of SWEs and the contribution of the Water Framework Directive (WFD) in promoting their conservation. Outcomes from this work open new perspectives on SWEs, which emerge as valuable ecosystems, and confirm their pivotal contribution to watershed biodiversity, resilience, and functionality. Results also suggest clear narrative trends and large knowledge gaps across geographical areas, biological components, and target issues. Additionally, we note that SWEs are under-represented in the frame of WFD implementation, stressing their marginality into assessing procedures. All of this calls for further studies, especially outside Europe and with a global, multi-taxon perspective. These should be devoted to quantitatively assess the roles of SWEs in maintaining global water ecosystem quality, biodiversity, and services, and to prioritize management actions for their conservation
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
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