2,594 research outputs found
Measurements of relative angular distributions for the 2H(γ,n)H reaction below 18 MeV
High-accuracy angular distribution measurements relative to that at 90° were performed for the 2(γ,n)H reaction throughout the energy range of 4–18 MeV and for reaction angles of 45°, 135°, and 155°. The results indicate a significant departure from existing theoretical calculations below a photon energy of 10 MeV
Registro da ocorrência de Helicoverpa armigera no Rio Grande do Sul, Brasil.
A presença de Helicoverpa armigera (Lepidoptera: Noctuidae: Heliothinae) no Brasil foi confirmada pela primeira vez na região do Cerrado (oeste da Bahia, Goiás e Mato Grosso) no inÃcio de 2013, por C. Czepak e colaboradores. Em seguida, A. Specht e colaboradores ampliaram o registro para outros estados, incluindo o Paraná. Admite-se que este inseto estava presente no paÃs há mais tempo, causando severos danos à s culturas agrÃcolas, principalmente em soja, algodão, milho e tomate industrial. No estado do Rio Grande do Sul, o problema veio à tona na safra 2012/13, quando técnicos e produtores se depararam com infestações elevadas e com a dificuldade de controle das lagartas na cultura da soja. Lagartas coletadas em lavouras de soja foram criadas em laboratório na FAMV/UPF e na Embrapa Trigo, em Passo Fundo. Das mariposas obtidas em laboratório, amostras provenientes de lagartas coletadas nos dias 20 e 21 de dezembro de 2012 em lavouras de soja localizadas dos municÃpios de Passo Fundo e Espumoso e de lagartas coletadas em soja no dia 22 de maio de 2013, em Carazinho, foram encaminhadas ao terceiro autor, taxonomista deste grupo de insetos, que confirmou a identidade especÃfica de H. armigera. Os resultados foram relatados ao Ministério da Agricultura, Pecuária e Abastecimento, que os considerou válidos como registro de ocorrência de H. armigera no Estado, através de comunicado aos autores no dia 19 de novembro de 2013. Na safra 2013/14, adultos foram coletados em armadilhas de feromônio sexual, em outubro. Lagartas grandes (5º e 6º instares) foram encontradas em trigo alimentando-se dos grãos em massa ou secos, além de canola e milho. A incidência maior foi em soja, desde os estádios iniciais (novembro) até a época de colheita (março). A ocorrência de adultos e de lagartas em várias localidades e regiões sugere que a espécie está amplamente distribuÃda no Rio Grande do Sul
Agricultural Communications: A National Portrait of Undergraduate Courses
Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs
Agricultural Communications: A National Portrait of Undergraduate Courses
Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs
Agricultural Communications: A National Portrait of Undergraduate Courses
Considerable research has been conducted regarding competencies needed by agricultural communication program graduates during the past four decades. However, no studies have considered actual program offerings. This study used a qualitative approach to analyze courses offered in agricultural communication programs in the United States. Using content analysis methods, researchers analyzed published course descriptions and discovered 21 categories among 172 courses. Most popular were writing courses, followed by courses introducing students to the major, internship courses, and writing for publication and graphic design courses. Categories with the fewest offerings included research, study abroad, and international focused courses. Findings from this analysis are consistent with previous literature noting the variety existing in agricultural communication programs at the national level. With the current growth of agricultural communication as an academic discipline and the fundamental role agricultural communicators play in sharing information about key societal issues at a time when agriculture has never been under greater pressure, this study is a first step in creating a national portrait of curricular offerings in agricultural communication programs
Generalized Involution Models for Wreath Products
We prove that if a finite group has a generalized involution model, as
defined by Bump and Ginzburg, then the wreath product also has a
generalized involution model. This extends the work of Baddeley concerning
involution models for wreath products. As an application, we construct a
Gelfand model for wreath products of the form with abelian, and
give an alternate proof of a recent result due to Adin, Postnikov, and Roichman
describing a particularly elegant Gelfand model for the wreath product \ZZ_r
\wr S_n. We conclude by discussing some notable properties of this
representation and its decomposition into irreducible constituents, proving a
conjecture of Adin, Roichman, and Postnikov's.Comment: 29 page
The Species Richness of Vascular Plants and Amphibia in Major Plant Communities in Temperate to Tropical Australia: Relationship with Annual Biomass Production
Aerodynamic fluxes (frictional, thermal, evaporative) in the atmosphere as it flows over and through a plant community determine the Foliage Projective Covers and eco-morphological attributes of new leaves developed annually in overstorey and understorey strata. The number of leaves produced on vertical foliage shoots depends on available soil water and nutrients, also ambient temperature, during this short growth season. Stem density (number of stems per hectare) and species richness (number of species per hectare) in the overstorey of major Floristic Groups are correlated with annual shoot growth (ASG, t ha −1 ) in that stratum. Species richness in the overstorey increases in the climatic gradient from the arid to the humid zone as well as with increasing air temperatures (about 10 o C) from temperate to tropical Australia. Species richness in the understorey is highest in plant communities in temperate Australia, decreasing in the temperature gradient towards the tropics. As with other major plant and animal groups within an ecosystem, the species richness of Amphibia is correlated with the amount of solar energy fixed (per annum) by the major plant formation in the region-a photosynthetic potential determined by the foliage shoots (ASG, t ha −1 ) produced annually in the overstorey
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