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Criopreservação de germoplasma de oleaginosas de importância econômica para o nordeste brasileiro
Get PDFThe conservation of germplasm of oleaginous species of the cotton (Gossypium hirsutum L.) and the castor bean (Ricinus communis L.) it is of great importance to guarantee the readiness of the resources genetic vegetables for the improvement. The cryoopreservation is seen as great alternative for conservation long term of the resources genetic vegetables. To present research it was developed in the National Center of Research of the Cotton (CNPA) of the Brazilian Company of Agricultural Research (EMBRAPA), Laboratory of Biotechnology, in Campina Grande, PB, with the objective of evaluating cryopreservation protocols for the cotton and the castor bean culture. Cotton seeds were used of the you cvs. BRS 200 and BRS 201 and of the castor bean seeds of the cvs. BRS 188 - Paraguaçu and BRS 149 - Nordestina for the obtaining of your embryonic axes and of the plantlets for the excision of the explants (shoot apices and nod cotiledonare). Among the cryopreservation techniques, they were appraised protocols of vitrification and encapsulation-dehydration for cotton explants and desiccation of embryonic axes of the cotton and of the castor bean culture. In the vitrification, the DMSO was used (0; 5; 10; and 15%) and/or sucrose (0; 0,1; 0,25 and 0,5 M) in the preculture of the explants for 48 hours. In the encapsulation-dehydration, explants were submitted or not to the preculture for 24 hours MS liquid medium supplemented with 0,3 M of sucrose and dived in the encapsulation solution, containing 3% of Na-alginate, forming a bead that involved the explant, which were maintened by 12 hours in MS liquid medium with 0,75 M of sucrose, on a rotary shaker at 130 rpm. The beads containing the explants was submitted to the desiccation by 0; 3; 6 and 9 hours in the flow camera to laminate, with subsequent determination of the content of water. In the procedure of desiccation of the embryonic axes, cotton and castor bean seeds they were submitted the imbibition in water for 24 hours for subsequent extraction of the embryonic axes in the flow camera to laminate, where axes stayed desiccation for 0; 30; 60 and 90 minutes after extraction, with subsequent determination of the content of water. In all experiments the explants they were them placed in cryotubes and directly plunged into liquid nitrogen (-196°C), during 0; 5; 30 and 60 days. At the end of each period, the thawing of the explants was accomplished fast (38±2°C for 1-2 min) and slowly (25±2°C for 60 min) and then cultured in vitro for four weeks, moment in that took place them analysis of viability of the cotton explants and embryonic axes of both species. The desiccation of the cotton embryonic axes for 60 minutes (16% of the content of water) and of the castor bean for 90 minutes (5% of the content of water), when obtained of imbibed seeds, it guaranteed regeneration after cryopreservation. The employment of the DMSO above 5% affected the viability of the explants. The encapsulation induced a reduction in the development of the explants and the desiccation it affected the regeneration. The vitrification and the encapsulation-dehydration didn't guarantee regeneration of the cotton explants cryopreserved.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPESA conservação de germoplasma de espécies oleaginosas como o algodoeiro (Gossypium hirsutum L.) e a mamoneira (Ricinus communis L.) é de grande importância para garantir a disponibilidade dos recursos genéticos vegetais para o melhoramento. A criopreservação é vista como ótima alternativa para conservação a longo prazo dos recursos genéticos vegetais. A presente pesquisa foi desenvolvida no Centro Nacional de Pesquisa do Algodão (CNPA) da Empresa Brasileira de Pesquisa Agropecuária (EMBRAPA), Laboratório de Biotecnologia, em Campina Grande, PB, com o objetivo de avaliar protocolos de criopreservação para o algodoeiro e a mamoneira. Foram utilizadas sementes de algodoeiro das cvs. BRS 200 e BRS 201 e da mamoneira cvs. BRS 188 - Paraguaçu e BRS 149 - Nordestina para a obtenção de seus eixos embrionários e de plântulas matrizes para excisão dos explantes (ápices caulinares e nós cotiledonares). Dentre as técnicas de criopreservação, foram avaliados protocolos de vitrificação e encapsulamento-dessecação para explantes de algodoeiro e dessecação de eixos embrionários do algodoeiro e da mamoneira. Na vitrificação, empregou-se o dimetilsulfóxido (0; 5; 10; e 15%) e/ou sacarose (0; 0,1; 0,25 e 0,5 M) no meio MS de pré-cultivo dos explantes por 48 horas. No encapsulamento-dessecação, explantes de algodoeiro foram pré-cultivados em MS com 0,3 M de sacarose por 24 horas e mergulhados na solução de encapsulamento com alginato de sódio a 3%; explantes encapsulados foram transferidos para cultivo em MS com 0,75 M de sacarose durante 12 horas sob 130 rpm e então submetidos a dessecação por 0; 3; 6 e 9 horas na câmara de fluxo laminar, com posterior determinação do teor de água. No procedimento de dessecação dos eixos embrionários, sementes de algodoeiro e mamoneira foram submetidas a embebição por 24 horas para posterior extração dos eixos embrionários na câmara de fluxo laminar, onde eixos permaneceram dessecando por 0; 30; 60 e 90 minutos após extração, com posterior determinação do teor de água. Em todos experimentos foram empregadas quatro réplicas de 10 unidades experimentais, que foram postas em criotubos e imersos no nitrogênio líquido (-196°C), onde permaneceram por 0; 5; 30 e 60 dias. Ao final de cada período, o descongelamento das amostras foi realizado rapidamente (38±2°C por 1-2 min) e lentamente (25±2°C por 60 min) e então cultivadas in vitro durante quatro semanas, momento em que se realizou as análise de viabilidade dos explantes de algodoeiro e eixos embrionários de ambas espécies. A dessecação dos eixos embrionários de algodoeiro por 60 minutos (16% do teor de água) e da mamoneira por 90 minutos (5% do teor de água), quando obtidos de sementes embebidas, garantiu regeneração após criopreservação. O emprego do dimetilsufóxido acima de 5% afetou a viabilidade dos explantes. O encapsulamento induziu uma redução no desenvolvimento dos explantes e a dessecação afetou a regeneração. A vitrificação e o encapsulamento-dessecação não garantiram regeneração aos explantes de algodoeiro criopreservados
SALINIDADE DA GERMINAÇÃO DE SEMENTES DE ALGODÃO COLORIDO
No full textCom o objetivo de avaliar o efeito de diferentes concentrações salinas sobre a germinação de sementes de algodão colorido, foi conduzido, na casa de vegetação do CCTA/UFCG, Pombal – PB, um experimento utilizando-se sementes das cvs. BRS-Rubi e BRS-8H, as quais foram submetidas a irrigação com solução salinas em diferentes concentrações de NaCl (0, 2, 4, 6 e 8 g.L-1) empregando-se quatro repetições de 25 sementes em um delineamento inteiramente casualizado. As variáveis analisadas foram: porcentagem de emergência, índice de velocidade de emergência, peso de matéria seca da raiz e peso de matéria seca de parte aérea. A salinidade afeta a velocidade e o total da emergência de plântulas de algodão, principalmente em concentrações superiores a 4 g de NaCl.L-1. A cultivar BRSRubri de algodão colorido se constitui numa linhagem tolerante a salinidade na fase de germinação. A presença de sais na solução empregada na irrigação do algodoeiro afeta a produção de biomassa
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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