1,720,958 research outputs found
Sexual and reproductive health is inadequately addressed in climate change actions in sub-Saharan Africa
No full textEffects of Weir Installation on Water Quality and Macroinvertebrate Community Structure of Two Rivers in Lake Victoria Basin, Kenya
No full textRiverine benthic communities play a crucial role in trophic relationships by providing major sources of energy to economically and ecologically important fishes. With the declining production of the Lake Victoria fisheries, the importance of surrounding rivers as sources of fish will continuously increase. There is therefore need to refocus the management of the riverine ecosystems in order to improve their fisheries production, particularly concerning their natural fish food production. Understanding the benthic invertebrate community dynamics and their responses to newly introduced management interventions such as weirs is key towards improving the riverine fisheries production. This study therefore aimed at assessing the benthic invertebrate composition, diversity and density in two small Lake Victoria Basin rivers (River Awach-seme and Kisian) before and after weir installation in order to establish the possible impacts of such management interventions on the benthic invertebrate community. Prior to weir installation, three sampling sites were selected along each river, representing the upper reaches (KS1 and AS1; KS- River Kisian, AS-River Awach-seme), middle (KS2 and AS2) and lower reaches (KS3 and AS3). Pre-weir sampling was carried fortnightly between August and October 2009 while post-weir sampling was carried out monthly between December 2009 and July 2010. Quantitative benthic invertebrates were sampled using a Hess sampler (100 μm). During every sampling, measurements of flow rate, water depth, temperature, dissolved oxygen, pH, conductivity, silicates, nitrates, phosphates and totals dissolved solutes were taken. Results showed that the two rivers to have similar physical and chemical characteristics, except for conductivity and silicates that differed significantly. Physico-chemical parameters, including dissolved oxygen, nitrates and turbidity, however differed significantly (p<0.05) among sites within Kisian River. Installation of weirs had insignificant impact on the physico-chemical parameters except nitrates that decreased significantly at both rivers while turbidity decreasing only at Kisian River Site KS2. Benthic invertebrate community at all sites was largely dominated by chironomidae before and after weir installation followed by the Ephemeroptera, particularly the genus Baetis sp. 26 genera were obtained at River Awach-seme while 23 at River Kisian before weir installation, 25 and 17 were obtained after weir installation respectively. Macroinvertebrate densities were significantly higher at Awach-seme. Density increased steadily during pre-weir period in both rivers, but declined though not significantly after weir installation. There were no significant differences in density among sites at any of the two rivers.
Macroinvertebrate Diversity (H') did not differ significantly among sites and within rivers before and after weir installation. PCA analysis showed TDS and conductivity to be closely related to macroinvertebrate densities. Mean water depth at upper Awach-seme showed a significant negative correlation with density. Other parameters were not significantly related to density. Most physical and chemical variables as well as benthic invertebrate density and diversity were observed to be unaltered by weir installation. These results did not support the hypothesis that weirs induce an improvement in the quality of in-stream habitats and change in benthic invertebrate communities. This research therefore provides baseline data for further action
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
How frontline communities are protecting SRHR amid climate change: Community solutions and regional insights—Slide deck
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