43 research outputs found

    Physics Opportunities with the 12 GeV Upgrade at Jefferson Lab

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    This white paper summarizes the scientific opportunities for utilization of the upgraded 12 GeV Continuous Electron Beam Accelerator Facility (CEBAF) and associated experimental equipment at Jefferson Lab. It is based on the 52 proposals recommended for approval by the Jefferson Lab Program Advisory Committee.The upgraded facility will enable a new experimental program with substantial discovery potential to address important topics in nuclear, hadronic, and electroweak physics.Comment: 64 page

    Analysis of the X(1835) and related baryonium states with Bethe-Salpeter equation

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    In this article, we study the mass spectrum of the baryon-antibaryon bound states ppˉp\bar{p}, ΣΣˉ\Sigma\bar{\Sigma}, ΞΞˉ\Xi\bar{\Xi}, ΛΛˉ\Lambda\bar{\Lambda}, pNˉ(1440)p\bar{N}(1440), ΣΣˉ(1660)\Sigma\bar{\Sigma}(1660), ΞΞˉâ€Č\Xi\bar{\Xi}^\prime and ΛΛˉ(1600)\Lambda\bar{\Lambda}(1600) with the Bethe-Salpeter equation. The numerical results indicate that the ppˉp\bar{p}, ΣΣˉ\Sigma\bar{\Sigma}, ΞΞˉ\Xi\bar{\Xi}, pNˉ(1440)p\bar{N}(1440), ΣΣˉ(1660)\Sigma\bar{\Sigma}(1660), ΞΞˉâ€Č\Xi\bar{\Xi}^\prime bound states maybe exist, and the new resonances X(1835) and X(2370) can be tentatively identified as the ppˉp\bar{p} and pNˉ(1440)p\bar{N}(1440) (or N(1400)pˉN(1400)\bar{p}) bound states respectively with some gluon constituents, and the new resonance X(2120) may be a pseudoscalar glueball. On the other hand, the Regge trajectory favors identifying the X(1835), X(2120) and X(2370) as the excited ηâ€Č(958)\eta^\prime(958) mesons with the radial quantum numbers n=3n=3, 4 and 5, respectively.Comment: 13 pages, 2 figures, revise a numbe

    Inheritance of resistance to bacterial spot in tomato

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    A herança da resistĂȘncia do tomateiro (Lycopersicon esculentum) Ă  mancha-bacteriana (Xanthomonas campestris pv. vesicatoria, raça T2) foi estudada, em condiçÔes de campo, cruzando-se os genĂłtipos resistentes 'Ohio 8245' e 'Hawaii 7998' com os genĂłtipos suscetĂ­veis 'CNPH 401-08' e 'CNPH 416.81.01.02', em um esquema dialĂ©lico desconsiderando-se os recĂ­procos. Foram obtidas cinco famĂ­lias, cada uma constituĂ­da por seis geraçÔes: Genitor1, Genitor2, F1, F2 e os retrocruzamentos (RC1 e RC2). A famĂ­lia 'Ohio 8245 ' Hawaii 7998' apresentou menor mĂ©dia para severidade da doença, seguida por 'Hawaii 7998 ' CNPH 416.81.01.02' e 'Ohio 8245 ' CNPH 416.81.01.02', as quais, apresentaram maiores estimativas de herdabilidade e de predição de ganho por seleção. Em todas combinaçÔes, a herança da resistĂȘncia genĂ©tica Ă  mancha-bacteriana foi do tipo quantitativa, com estimativa do nĂșmero de genes variando de quatro a oito genes, conforme a famĂ­lia analisada. Foi observada segregação transgressiva nas famĂ­lias 'Ohio 8245 ' CNPH 401-08', 'Hawaii 7998 ' CNPH 401-08' e 'Hawaii 7998 ' CNPH 416.81.01.02'. Os efeitos gĂȘnicos foram do tipo aditivo para todas as famĂ­lias e os dados ajustados ao modelo aditivo-dominante, com o componente aditivo apresentando maior magnitude.The inheritance of resistance to bacterial spot (Xanthomonas campestris pv. vesicatoria, race T2) in tomato (Lycopersicon esculentum) was investigated in a field trial. The genotypes 'Ohio 8245' and 'Hawaii 7998' (resistant), 'CNPH 401-08' and 'CNPH 416.81.01.02' (susceptible) were crossed in a diallel scheme without reciprocals. Each cross was labeled as one family, represented by six different generations: Parent1, Parent2, F1, F2 and Backcrosses to parents (BC1 and BC2). The family 'Ohio 8245 ' Hawaii 7998' presented the lowest disease severity, followed by the family 'Hawaii 7998 ' CNPH 416.81.01.02' and by the family 'Ohio 8245 ' CNPH 416.81.01.02'. These last two families showed both higher broad and narrow sense inheritability estimates and the highest prediction of selection gain. The resistance was found to be quantitative, with four to eight genes involved, depending on the family. Transgressive segregation was observed in the 'Ohio 8245 ' CNPH 401-08', the 'Hawaii 7998 ' CNPH 401-08' and the 'Hawaii 7998 ' CNPH 416.81.01.02' families. The relevance of the additive effects was observed and for all the families the data fitted to additive-dominant model, with the additive component showing greater magnitude

    Estudos ArtĂ­sticos

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    O nĂșmero 18 da revista Gama apresenta 16 artigos respondendo ao desafio a editorial lançado por esta revista. Trata-se de apresentar a obra de artistas contemporĂąneos ou mais antigos numa perspetiva de um resgate patrimonial, uma revisitação valorizadora do seu testemunho artĂ­stico.info:eu-repo/semantics/publishedVersio

    NEOTROPICAL XENARTHRANS: a data set of occurrence of xenarthran species in the Neotropics

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    Xenarthrans – anteaters, sloths, and armadillos – have essential functions for ecosystem maintenance, such as insect control and nutrient cycling, playing key roles as ecosystem engineers. Because of habitat loss and fragmentation, hunting pressure, and conflicts with 24 domestic dogs, these species have been threatened locally, regionally, or even across their full distribution ranges. The Neotropics harbor 21 species of armadillos, ten anteaters, and six sloths. Our dataset includes the families Chlamyphoridae (13), Dasypodidae (7), Myrmecophagidae (3), Bradypodidae (4), and Megalonychidae (2). We have no occurrence data on Dasypus pilosus (Dasypodidae). Regarding Cyclopedidae, until recently, only one species was recognized, but new genetic studies have revealed that the group is represented by seven species. In this data-paper, we compiled a total of 42,528 records of 31 species, represented by occurrence and quantitative data, totaling 24,847 unique georeferenced records. The geographic range is from the south of the USA, Mexico, and Caribbean countries at the northern portion of the Neotropics, to its austral distribution in Argentina, Paraguay, Chile, and Uruguay. Regarding anteaters, Myrmecophaga tridactyla has the most records (n=5,941), and Cyclopes sp. has the fewest (n=240). The armadillo species with the most data is Dasypus novemcinctus (n=11,588), and the least recorded for Calyptophractus retusus (n=33). With regards to sloth species, Bradypus variegatus has the most records (n=962), and Bradypus pygmaeus has the fewest (n=12). Our main objective with Neotropical Xenarthrans is to make occurrence and quantitative data available to facilitate more ecological research, particularly if we integrate the xenarthran data with other datasets of Neotropical Series which will become available very soon (i.e. Neotropical Carnivores, Neotropical Invasive Mammals, and Neotropical Hunters and Dogs). Therefore, studies on trophic cascades, hunting pressure, habitat loss, fragmentation effects, species invasion, and climate change effects will be possible with the Neotropical Xenarthrans dataset
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