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Impact of the damming in an amazonian river on the spatial and temporal patterns of phytoplankton beta diversity.
No full textHuman activities have caused degradation of aquatic ecosystems and reduced biodiversity. The dams in particular directly impact the spatial and temporal variation of aquatic communities, and especially the phytoplankton community that responds quickly and efficiently to changes in the environment. The impact of a dam in an Amazon river (Jirau Hydroelectric Power Plant) on the spatial and temporal variation of the composition (beta diversity) of phytoplankton was investigated, from October 2009 to July 2017. The hypothesis was tested that the bus modifies beta diversity on a local and regional scale, and alters each location's contribution to beta diversity. The contribution of the sites to the beta diversity was evaluated as a function of the distance from the bus and the environmental heterogeneity. The phytoplankton composition was different between the phases before, fill and after the damming. Biotic homogenization was verified in the tributaries closest to the dam. The more distant sites presented greater contribution to diversity, but were associated with lower values of richness. The dam caused unidirectional changes, locally and regionally, that is, the community moved to a new state over time, and also caused biotic homogenization locally. The impact of the dam was observed only on the tributaries, indicating that run-of-river dams have a greater impact on the tributaries than on the main channel.CAPESAs atividades humanas têm causado degradação dos ecossistemas aquáticos e reduz a biodiversidade. Os barramentos em especial, impactam diretamente a variação espacial e temporal das comunidades aquáticas, e especialmente a comunidade fitoplanctônica que responde de forma rápida e eficiente às mudanças do ambiente. Investigou-se o impacto de um barramento em um rio amazônico (Usina Hidrelétrica de Jirau) sobre a variação espacial e temporal da composição (diversidade beta) do fitoplâncton, no período de outubro de 2009 a julho de 2017. Foi testado a hipótese de que o barramento modifica a diversidade beta em escala local e regional, e altera a contribuição de cada local à diversidade beta. Avaliou-se a contribuição dos locais para a diversidade beta em função da distância do barramento e da heterogeneidade ambiental. A composição fitoplanctônica foi diferente entre as fases antes, enchimento e após o barramento. Verificou-se homogeneização biótica nos tributários mais próximos a barragem. Os locais mais distantes apresentaram maior contribuição a diversidade, mas foram associados a menores valores de riqueza. O barramento causou mudanças unidirecionais, localmente e regionalmente, ou seja, a comunidade passou para um novo estado ao longo do tempo, e também causou homogeneização biótica localmente. Observou-se o impacto do barramento somente nos tributários, indicando que as barragens a fio de água têm maior impacto nos tributários do que no canal principal.53 f. : il. (algumas color.)
Impact of the damming in an amazonian river on the spatial and temporal patterns of phytoplankton beta diversity.
No full textHuman activities have caused degradation of aquatic ecosystems and reduced biodiversity. The dams in particular directly impact the spatial and temporal variation of aquatic communities, and especially the phytoplankton community that responds quickly and efficiently to changes in the environment. The impact of a dam in an Amazon river (Jirau Hydroelectric Power Plant) on the spatial and temporal variation of the composition (beta diversity) of phytoplankton was investigated, from October 2009 to July 2017. The hypothesis was tested that the bus modifies beta diversity on a local and regional scale, and alters each location's contribution to beta diversity. The contribution of the sites to the beta diversity was evaluated as a function of the distance from the bus and the environmental heterogeneity. The phytoplankton composition was different between the phases before, fill and after the damming. Biotic homogenization was verified in the tributaries closest to the dam. The more distant sites presented greater contribution to diversity, but were associated with lower values of richness. The dam caused unidirectional changes, locally and regionally, that is, the community moved to a new state over time, and also caused biotic homogenization locally. The impact of the dam was observed only on the tributaries, indicating that run-of-river dams have a greater impact on the tributaries than on the main channel.As atividades humanas têm causado degradação dos ecossistemas aquáticos e reduz a biodiversidade. Os barramentos em especial, impactam diretamente a variação espacial e temporal das comunidades aquáticas, e especialmente a comunidade fitoplanctônica que responde de forma rápida e eficiente às mudanças do ambiente. Investigou-se o impacto de um barramento em um rio amazônico (Usina Hidrelétrica de Jirau) sobre a variação espacial e temporal da composição (diversidade beta) do fitoplâncton, no período de outubro de 2009 a julho de 2017. Foi testado a hipótese de que o barramento modifica a diversidade beta em escala local e regional, e altera a contribuição de cada local à diversidade beta. Avaliou-se a contribuição dos locais para a diversidade beta em função da distância do barramento e da heterogeneidade ambiental. A composição fitoplanctônica foi diferente entre as fases antes, enchimento e após o barramento. Verificou-se homogeneização biótica nos tributários mais próximos a barragem. Os locais mais distantes apresentaram maior contribuição a diversidade, mas foram associados a menores valores de riqueza. O barramento causou mudanças unidirecionais, localmente e regionalmente, ou seja, a comunidade passou para um novo estado ao longo do tempo, e também causou homogeneização biótica localmente. Observou-se o impacto do barramento somente nos tributários, indicando que as barragens a fio de água têm maior impacto nos tributários do que no canal principal.Master
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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