1,720,969 research outputs found
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
Fatores controladores do metabolismo aquático em lagos de Mata Atlântica
Get PDFTese (doutorado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas, Programa de Pós-Graduação em Ecologia, Florianópolis, 2016.Os lagos inseridos no bioma Mata Atlântica são importantes ecossistemas para a ciclagem do carbono podendo atuar como fontes ou sumidouros de carbono. Nesta tese foi abordado o metabolismo aquático ecossistêmico de dois lagos brasileiros, utilizando as taxas de produção primária e respiração, bem como o fluxo de CO2 entre a água e a atmosfera, para entender como as variáveis limnológicas e meteorológicas direcionam a dinâmica espaço-temporal do metabolismo ecossistêmico. Nossos resultados mostraram que a Lagoa do Peri foi predominantemente heterotrófica, com períodos de autotrofia em condições de alta temperatura e luminosidade. Analisando a dinâmica espacial das taxas metabólicas, a região litorânea apresentou maior variabilidade que a região pelágica, bem como maiores taxas de respiração, em função da baixa profundidade da coluna d?água, influência do sedimento e do ecossistema terrestre. Verticalmente maiores taxas de produção primária foram registradas na superfície, diminuindo em direção ao fundo, e as taxas de respiração mostraram padrão inverso. Ao longo de oito anos consecutivos observamos que a diminuição do nível d?água ao longo dos anos de 2012 e 2014 foi reflexo da baixa precipitação. Essa mudança física promoveu aumento na concentração de clorofila-a, nutrientes, carbono e o fluxo de CO2 para a atmosfera. A Lagoa Carioca também se mostrou heterotrófica e o fluxo de CO2 foi intensificado quando adições experimentais de matéria orgânica foram conduzidas em mesocosmos. Por outro lado, a adição de nutrientes inorgânicos resultou no aumento do O2, com diminuição do CO2 e alta variabilidade diária. Esta tese mostrou que o metabolismo ecossistêmico de lagos de Mata Atlântica é altamente dinâmico e predominantemente heterotrófico com diferentes variáveis sendo importantes nas diversas escalas espacial e temporal. Entretanto, sugerimos que em um lago polimítico as variáveis físicas como disponibilidade de luz, estabilidade térmica e profundidade da coluna d?água determinam a variação espaço-temporal das taxas metabólicas. Além disso, mudanças climáticas afetando a região tropical pode alterar as características limnológicas dos lagos, que por sua vez podem intensificar ou alterar a função dos ecossistemas na ciclagem do carbono.Abstract : Lakes in the Atlantic Forest are important ecosystems for the carbon cycling and they can be sources or carbon sinks. This thesis addressed the aquatic ecosystem metabolism of two Brazilian lakes, using the primary production and respiration rates, as well as the air-water CO2 flux to understand how limnological and meteorological variables affect the spatio-temporal dynamics of ecosystem metabolism. Our results showed that the Peri Lake was predominantly heterotrophic due to bacterioplankton. However, during high temperature and light conditions the lake was net autotrophic. Regarding to the spatial dynamics of metabolic rates, the coastal area showed higher variability than the pelagic area, as well as higher respiration rates, which was related to the low water column depth, influence of sediment and terrestrial ecosystem. Vertically we recorded higher primary production rates at surface, decreasing toward the bottom, and respiration rates showed the opposite pattern. Over eight consecutive years Peri Lake featured decrease in water level over the years 2012 and 2014 due to low rainfall. This physical change increased the chlorophyll-a, nutrients, carbon and CO2 flux to the atmosphere. Carioca Lake was also heterotrophic and experimental additions of organic matter promoted the increase in CO2, while the addition of inorganic nutrients resulted in an O2 increase concomitant with CO2 decrease and high daily variability in both gases. This thesis showed that the ecosystem metabolism from Atlantic Forest lakes is highly dynamic and predominantly heterotrophic with many variables being important in the different spatio-temporal scales. However, we suggest that in a polymictic lake the physical variables, such as light availability, thermal stability and water column depth, determine the spatial and temporal variation in the metabolic rates. In addition, climate change affecting tropical areas can change the limnological conditions in the lakes, intensifying or changing the ecosystems function in the carbon cycling
Produção primária e respiração pelágica em um lago costeiro subtropical (lagoa do Peri, Brasil): variações vertical e temporal e suas relações com a comunidade fitoplanctônica
Get PDFDissertação (mestrado) - Universidade Federal de Santa Catarina, Centro de Ciências Biológicas. Programa de Pós-Graduação em EcologiaLagos costeiros são ambientes que apresentam características particulares quanto a sua dinâmica, estado trófico, morfologia e interação das comunidades biológicas. Em geral, são ambientes rasos submetidos à intensa ação dos ventos. A lagoa do Peri localizada na ilha de Santa Catarina (27°44#S e 48°31#W) é um sistema costeiro subtropical de água doce com 5,7 km2 de área e 4,2 m de profundidade média. De acordo com a literatura, apresenta homogeneidade horizontal e vertical para clorofila a e nutrientes, característica oligotrófica para a concentração de nutrientes e presença de cianobactérias. Com o objetivo de verificar a ocorrência de autotrofia e heterotrofia na lagoa do Peri, determinaram-se as taxas de produção primária (bruta e líquida) e de respiração fitoplanctônica através de incubações em garrafas claras e escuras durante 24 horas no outono, inverno, primavera e verão. Incubações em garrafas claras e escuras, também foram conduzidas bimensalmente, em quatro profundidades em uma estação central da lagoa, para avaliar a variação vertical das taxas de produção primária (bruta e líquida) e de respiração bem como sua relação com a comunidade fitoplanctônica. Condições de heterotrofia foram encontradas no outono, quando as maiores taxas de respiração ocorreram devido ao aumento da disponibilidade de matéria orgânica e fósforo total. Condições de autotrofia ocorreram no verão devido às maiores taxas de produção primária líquida, favorecida pelas maiores temperaturas e luz. As taxas de produção primária, respiração e a densidade dos grupos fitoplanctônicos, em geral, não apresentaram variação vertical, em função da homogeneização promovida pelos ventos incidentes na lagoa do Peri. Condições limitantes de luz e nutrientes, para o crescimento fitoplanctônico, foram os fatores atribuídos as menores taxas de produção primária encontradas neste ambiente em relação a outros ambientes tropicais e subtropicais. A densidade fitoplanctônica e condições de temperatura e luz favoreceram a produção primária na primavera e no verão. Cyanobacteria e Chlorophyta foram os grupos mais importantes da comunidade fitoplanctônica, em termos de densidade e diversidade, com destaque para Cylindrospermopsis raciborskii que dominou na maior parte do período de estudo. Assim, a lagoa do Peri apresentou alternância entre períodos autotróficos e heterotróficos em função das diferentes condições ambientais e as taxas de produção primária foram menores que em outros ambientes, variando em função das variáveis bióticas e abióticas.Coastal lakes are environments with distinct characteristics when it comes to dynamics, trophic state, morphology, and the interaction of biological communities. They are generally shallow environments subjected to intense winds. Peri lagoon located on the island of Santa Catarina (27°44'S and 48°31'W) is a subtropical coastal system of freshwater with an area of 5.7 km2 and average depth of 4.2 m. According to literature, it is horizontally and vertically homogenous for chlorophyll a and nutrients, oligotrophic characteristics for nutrient concentration and presence of Cyanobacteria. In order to verify the occurrence of autotrophy and heterotrophy in the Peri lagoon, primary production (gross and net) and respiration rates were determined by incubating in light and dark bottles over a period of 24 hours in the fall, winter, spring and summer. Incubations in light and dark bottles were also conducted every two months, at four depths in the central part of the lagoon, in order to evaluate the vertical variation in primary production rates (gross and net) and respiration and the relationship to the phytoplankton community. Heterotrophic conditions were found in autumn, where the highest rates of respiration were found due to an increased availability of organic matter and total phosphorus. Autotrophic conditions occurred in the summer due to higher rates of net primary production, favored by higher temperatures and light availability. In general, the primary production rates, respiration and phytoplankton group density, did not show vertical variation due to the homogenization promoted by winds in the Peri lagoon. Light and nutrients limitation were attributed to the lower rates of primary production found in this environment than other ones. However, phytoplankton density, temperature and light conditions favored the primary production rates in spring and summer. Cyanobacteria and Chlorophyta were the most important groups of the phytoplankton community in terms of density and diversity, especially Cylindrospermopsis raciborskii, which was dominant during the majority of the study period. Thus, the Peri lagoon had alternating autotrophic and heterotrophic periods due to different environmental conditions and the primary production rates were lower than other tropical environments, depending on biotic and abiotic variables
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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