1,721,117 research outputs found
Policy and diplomacy in the production of second generation ethanol in Brazil: international relations with the EU, the USA and Africa
No full textConcerns over the global energy crisis and climate change are increasingly mediated through the deployment of renewable energy sources, such as biofuels. Second generation (2G) biofuels derived from non-edible feedstocks offer more sustainable and higher productive alternatives than first generation (1G) ones, which are more water and land intensive. New cooperation opportunities, particularly among Brazil, the USA and the EU, have been generated by the emerging 2G global market. Future expansion of 2G production and consumption in the African continent is envisaged to offer a range of benefits, including decreased oil dependency and generation of economic activities which can foster rural development. This chapter outlines the current state of affairs with respect to 2G biofuels in Brazil, including discussion on the future prospects of introducing 2G production in Africa. Opportunities and challenges of 2G cooperation between Brazil, the USA and the EU are discussed. Secondary data from government documents, published reports and scientific studies were integrated with semi-structured interviews and personal communications with Brazilian line ministries and EU officials. Data show a great potential for the expansion of Brazil’s 1G ethanol industry in Africa, but 2G development is not identified as a foreseeable option in the forthcoming years. This is due to the high production costs, lack of advanced technology and the unattractive business environment. The creation of a 1G consumer market and establishment of safe legal and policy frameworks are needed in order to foster 2G investments. As observed in terms of international cooperation, Brazil’s potential to foster 2G technologies in Africa is compromised by a disconnect between science production, industrial and policy developments. Cooperation of Brazil with the EU is focused on fundamental sciences, while linkages with the USA are limited to private sector and market development. Increased policy coordination towards the transition from 1G to 2G, as well as stronger budget support, is key for enabling Brazil’s future leadership in the international 2G arena
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
Patterns of structural and non-structural carbon allocation in five species of duckweeds (Lemnaceae)
No full textLentilhas d´água são as menores angiospermas aquáticas monocotiledôneas, as quais são classificadas em duas subfamílias (Lemnoideae e Wolffioideae) que contemplam trinta e sete espécies representando cinco gêneros: Spirodela, Landoltia, Lemna, Wolffiella e Wolffia (APPENROTH; BORISJUK; LAM, 2013; BORISJUK et al ., 2015; FAO, 1999; LANDOLT, 1992, LES et al ., 2002). Essas plantas apresentam rápida reprodução vegetativa o que implica no acúmulo acelerado de carboidratos e proteínas, que por sua vez, confere uma enorme aplicação industrial e biotecnológica, especialmente na bioenergia (APPENROTH; BORISJUK; LAM, 2013; FAO, 1999). O balanço de carbono no crescimento relaciona-se com à assimilação fotossintética, armazenamento e consumo desses compostos, que são influenciados pela intensidade de luz (SMITH; STITT, 2007; STITT; ZEEMAN, 2012). O maior dreno de carbono assimilado é para a síntese de parede celular e sacarose, portanto, conhecendo a composição dos polissacarídeos e suas interações junto com o conteúdo de carboidratos não estruturais impacta a produção de combustíveis alternativos. O presente trabalho visou quantificar e analisar os carboidratos estruturais (açúcares de parede celular apiose, arabinose, fucose, ramnose, glicose, xilose, galactose e manose) e não estruturais (açúcares solúveis e de armazenamento sacarose, frutose, rafinose, glicose e amido) de três espécies de Lemnoideae e duas Wolffioideae comparando com as taxas de crescimento dessas plantas.Duckweeds are the smallest aquatic monocots classified in two subfamilies (Lemnoideae and Wolffioideae) that contemplates thirty-seven species representing five genera: Spirodela, Lemna, Landoltia, Wolffia and Wolffiella . These plants display fast vegetative reproduction, which implies a rapid accumulation of carbohydrates and protein, conferring them biotechnological and industrial applications, especially in bioenergy. Carbon balance among growth is related to photosynthetic assimilation, storage, and consume of compounds which are influenced by light intensity. The major sink of the carbon assimilated is to cell wall and sucrose synthesis, thereby knowing the polysaccharides composition and their interactions together with the non-structural carbohydrates content may impact the alternative fuels production. The present work aimed to quantify and comparative analyze structural (cell wall sugars apiose, arabinose, fucose, rhamnose, glucose, xylose, galactose, and mannose) and nonstructural (storage and soluble sugars starch, sucrose, glucose, raffinose, and fructose) carbohydrates of three Lemnoideae and two Wolffioideae species correlating to its growth rates
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
In silico prediction of the role of ScRAV1 on cell wall genes and transcription factors during the formation of the aerenchyma in the sugarcane root
No full textAs modificações nas paredes celulares de células de raízes de cana têm sido usadas como modelo para entender como as paredes poderiam ser alteradas in vivo. As alterações na parede de células corticais de raízes de cana se iniciam com modificações nas pectinas que são responsáveis pelas junções intercelulares (lamela média). O fator de transcrição ScRAV1 demonstrou controlar a expressão de uma endopoligalacturonase que degrada pectinas, iniciando o processo de formação do aerênquima que ocorre concomitantemente com a morte celular programada e forte alteração na parede, gerando um compósito que constitui a formação dos espaços de transporte de gases nas raízes. Paralelamente, os padrões de expressão de vários transcritos (RNA-Seq) para genes de parede celular foram descritos recentemente por nosso grupo. Este trabalho teve como objetivo predizer possíveis transcritos de parede celular e fatores de transcrição que podem ser modulados pelo fator de transcrição ScRAV1 através das redes de co-expressão e de regulação gênica durante a formação do aerênquima em cana-de-açúcar. Nossas análises mostraram que ScRAV1 apresenta co-expressão com vários transcritos de parede celular, bem como com outros fatores de transcrição ao longo dos primeiros 5 centímetros da raiz de cana-de-açúcar. As redes de regulação gênica do ortólogo ScRAV1 em S. bicolor mostraram uma predominância de transcritos de parede celular associada à biossíntese de lignina, dois transcritos relacionados à hidrólise de hemicelulose/celulose (ScGH3 2 e ScEGase4) e dois transcritos relacionados à hidrólise de pectina (ScPAE2 e ScPGase1). Já para os fatores de transcrição foram identificados cinco transcritos que possivelmente regulam a biossíntese de lignina (ScNAC3, ScNAC5, ScNAC7, ScHB6 e ScMYB2), dois associados à sinalização de auxina (ScARF1 e ScARF3), e dois relacionados à morte celular programada (ScNAC2 e ScNAC8) durante o desenvolvimento do aerênquima lisígeno na raiz de cana-de-açúcar. Nossos dados confirmam a hipótese prévia de que a formação do aerênquima nas raízes de cana é feita através de módulos de ação de enzimas hidrolíticas, tendo o controle da expansão celular por auxinas e a morte celular programada como processo concorrente em paralelo às modificações na parede celularModifications in the cell walls of roots of sugarcane have been used as a model to understand how its cell walls could be altered in vivo. The alteration in the walls of cortex cells initiate with modifications in the pectins, which are responsible for the cohesion in the middle lamella. The transcription factor ScRAV1 has been demonstrated to control the expression of an endo-polygalacturonase that degrades pectins, initiating the process of formation of the aerenchyma, which occurs concomitantly with programmed cell death. At the same time, the expression patterns of cell wall-related genes have been studied by our group recently. Thus, this work aimed to predict possible cell wall transcripts and transcription factors that may be modulated by ScRAV1 through coexpression and gene regulatory networks during the aerenchyma formation in sugarcane. The co-expression networks of ScRAV1 showed that this transcription factor can co-express with types of cell wall transcripts and transcription factors in the different segments of the sugarcane roots. The gene regulatory networks of the ortholog of ScRAV1 in S. bicolor showed a predominance of cell wall transcripts associated with lignin biosynthesis, two transcripts related to hemicellulose/cellulose hydrolysis (ScGH3 2 and ScEGase4) and two transcripts related to pectin hydrolysis (ScPAE2 and ScPGase1). As for the transcription factors were identified five transcripts that possibly regulate the lignin biosynthesis (ScNAC3, ScNAC5, ScNAC7, ScHB6 and ScMYB2), two transcripts associated with auxin signaling (ScARF1 and ScARF3), and two transcripts related to programmed cell death (ScNAC2 and ScNAC8) during the development of the lysigenous aerenchyma in the sugarcane root. Our results confirm our previous hypothesis that aerenchyma formation occurs through modules that include the action of hydrolases and have cell expansion controlled by auxin and programmed cell death as a concurrent process with modifications in the cell wal
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