1,720,955 research outputs found
The impact of hydrological dynamics on cladocera community in a deep sub-alpine lake (L. Iseo): a paleolimnological perspective
No full textLake deposits provide ideal archives to study the past catchment dynamics and the related response of
lake ecosystems. In particular, sediment records deposited over long time periods can provide information
on lake development stages preceding the moment of the most relevant human disturbance, and can help
disentangling and quantifying the lake ecosystem responses to natural variability and human perturbation,
such as climatic and hydrological variation, eutrophication and chemical contamination. Subfossil
Cladocera records allow tracking long-term changes in both bottom-up drivers and top-down regulators
and they particularly respond to alterations in nutrients, temperature and water level. The aim of this work
was to investigated a short sediment core from a deep subalpine lake (Lake Iseo, northern Italy) aiming at
reconstructing the influence of human activities and climate variability on the lake ecosystem. We
compared the sediment records with historical information on major hydrological events during the last
century, and with climate-related limnological data. As already observed in other subalpine lakes, the
sediment records of Lake Iseo suggest that catchment related processes are able to decisively affect the
food web dynamics and the lake functionalities. In particular, we observed that a series of flood events in
the period between the 1970s and 1980s resulted in a decrease in the Cladocera total abundance and a
prevalence of the littoral species over the pelagic one. The decline of the pelagic species has been
attributed to the transport of inorganic material from the catchment area to the lake
A paleolimnological investigation of the impact of catchment dynamics on pelagic communites in a deep south-alpine lake (L. Iseo)
No full textEffects of watershed hydrology on food web of deep south-alpine lake: a paleolimnological perspective
No full textSubfossil Cladocera are a valuable biological proxy, able to complement the diatom based reconstruction of past lake trophic evolution by providing information on lake responses to watershed hydrology and climate-related environmental perturbations.This work aims at the paleolimnological reconstrunction of ecological response of pelagic communities to environmental changes in the subalpine Lake Iseo, Italy, during the XX century. A combinated study of lithological parameters and subfossil Cladocera and diatoms remains has been carried out on a sediment core collected in the lake in 2014.The analysis of the selected proxies outlined a pronounced sensitivity of Lake Iseo to major hydrological events in the catchment area, in close connected to climatic variability and land use. The effects of hydrological variability on the lake ecology are amplified by the large ratio between catchment area and lake area (~30). The decrease in the Cladocera total abundance and the increase of the proportion of littoral species has been attributed to the transport of inorganic material to the lake by a series of flood events occurred between the mid ’70s and the beginning of the ‘80s. The sediment records suggest that catchment related processes may influence the food web dynamics and functionalities of Lake Iseo in a decisive way, also during stages of enhanced lake productivity
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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