117,650 research outputs found
Avaliação de cultivares de soja com relação à preferência a Bemisia tabaci Biótipo B (Hemiptera: Aleyrodidae) com chance de escolha a campo.
No full textA mosca-branca está entre as várias pragas que atacam a cultura da soja. São insetos que sugam a seiva das plantas hospedeiras, tanto na fase jovem como na adulta, podendo causar danos diretos a planta, como seu enfraquecimento e o desenvolvimento de fumagina sobre as folhas, com reflexos na produtividade, e danos indiretos, devido à sua capacidade de transmitir viroses. Entre os vários métodos de controle, o uso de cultivares menos preferidas, pode ser uma ferramenta para o manejo sustentável desta praga. Assim este experimento foi realizado no município de Primavera do Leste, MT, com o objetivo de avaliar diferentes cultivares de soja com relação à preferência a mosca-branca Bemisia tabaci biótipo B em testes com chance de escolha a campo. O delineamento experimental foi de blocos ao acaso com quatro repetições. A parcela foi constituída de 12 linhas com 8m de comprimento. As cultivares (crescimento/ grupo de maturação) testadas foram: 1. TMG1188 RR (semideterminado/8.8), 2. NA8015 RR (indeterminado/8.3), 3. TMG1288 RR (determinado/8.8), 4. TMG133 RR (determinado/8.5), 5. TMG1176(determinado/7.6), 6. TMG127 RR (indeterminado/7.2), 7, TMG132 RR (determinado/8.5) e 8. P98Y11 (determinado/8.1). Avaliou-se o número de ninfas em 10 folíolos centrais do terço médio da planta de cada parcela aos, 35, 41, 50 e 62 dias após plantio. As cultivares P98Y11; TMG132 RR e TMG1176 RR foram às menos infestadas com ninfas de mosca-branca no período avaliado, com infestação 71% menor que as cultivares mais infestadas. A maior população de ninfas foi observada aos 41 dias após o plantio com um número médio de 214 ninfas por folíolo. A população de ninfas caiu para 97,3 ninfas/folíolo na 3ª avaliação e reduziu para 0,5 ninfas/folíolo aos 62 dias após o plantio em todas as cultivares avaliadas, quando foram finalizadas as avaliações
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Square Dancing with the Stars to Enhance Dynamic Hirschman Linkages?
No full textIn this Presidential Address, the author takes the reader on a reconnaissance of his life and time as a regional scientist. He points out scenery he found scintillating along the way, hoping that some may pick up the banner and chew on a few of the ideas for a while. He suggests a revisit to Albert O. Hirschman’s notion of key sectors and more empirical analysis related to Marcus Berliant’s and Masahisa Fujita’s notion of knowledge creation and transfer.Presidential Address, San Antonio, Texas, March 29, 2014 (53rd Meetings of the Southern Regional Science Association
Appropriate Similarity Measures for Author Cocitation Analysis
No full textWe 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
Letter from unknown writer to Jesse L. Boyce
No full textLetter to Jesse L. Boyce from unknown author (possibly Jack) about the investigation into the powder magazine located in the Grand Canyon. Some personal news is included in the letter such as the writer's marriage to the daughter of C.A. Taylor, former Supervisor of Cochise County
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