2,116 research outputs found

    Produção de palha e forragem por espécies anuais e perenes em sucessão à soja.

    Get PDF
    O objetivo deste trabalho foi avaliar a produção de palha e de forragem por forrageiras anuais e perenes implantadas em sucessão à cultura da soja, e seus efeitos sobre a produtividade de grãos da cultura no próximo cultivo. O delineamento experimental utilizado foi o de blocos ao acaso, com parcelas subdivididas (crescimento livre e sob cortes sucessivos), com quatro repetições. Foram avaliadas oito forrageiras em dois municípios de Mato Grosso do Sul. A produção de palha e forragem foi avaliada em 2005 e 2006, nas espécies Urochloa ruziziensis; U. decumbens; U. brizantha cv. Marandu e Xaraés; Panicum maximum cv. Tanzânia e Mombaça, P. maximum x P. infestans cv. Massai; Pennisetum americanum cv. BRS 1501; e Sorghum bicolor cv. Santa Elisa. As forrageiras foram semeadas mecanicamente após a colheita da soja, em 1/4/2005 e 24/3/2006, em São Gabriel do Oeste, e em 20/3/2005 e 13/3/2006, em Dourados. Sorgo, U. brizantha cv. Xaraés e P. maximum cv. Tanzânia apresentaram características como elevada produtividade, alta qualidade da forragem e facilidade de controle, favoráveis para produção tanto de forragem quanto de palha. Urochloa ruziziensis e U. decumbens apresentaram melhor desempenho para a produção de palha. O cultivo das espécies forrageiras em sucessão à soja não afeta a produtividade da cultura.The objective of this work was to evaluate forage and straw production, of annual and perennial forage implanted in succession to soybean, and their effects on crop grain yield in the following season. The experimental design was in randomized blocks with four replicates, in a split-plot arrangement (free growth and successive cuts). Eight forages were evaluated in two municipalities of the state of Mato Grosso do Sul, Brazil. Straw and forage production was evaluated in 2005 and 2006, in the following species: Urochloa ruziziensis, U. decumbens; U. brizantha cv. Marandu and Xaraés; Panicum maximum cv. Tanzânia and Mombaça, P. maximum x P. infestans cv. Massai, Pennisetum americanum cv. BRS 1501, and Sorghum bicolor cv. Santa Elisa. Forages were planted mechanically, after the soybean crop harvest on 4/1/2005 and 3/24/2006, in São Gabriel do Oeste, and 3/20/2005 and 3/13/2006, in Dourados. Sorghum, U. brizantha cv. Xaraés and P. maximum cv. Tanzânia characteristics, such as high productivity, high forage quality and easiness in control, were favorable for production of both forage and straw. Urochloa ruziziensis and U. decumbens showed better performance for straw production. Forage cultivation in soybean succession does not affect crop yield

    Sorgo para pastejo/corte e cobertura do solo no período de outono/inverno (safrinha) em Mato Grosso do Sul.

    Get PDF
    Em Mato Grosso do Sul, as principais culturas utilizadas para cobertura de solo na safrinha são o milheto, a aveia e o nabo (Hernani et al., 1995; Machado, 2003). Para pastejo, também são utilizadas essas espécies, com exceção do nabo. Devido ao risco de geadas, as espécies adaptadas ao clima frio, como a aveia e o nabo, são mais utilizadas na região sul do Estado. Na região norte, o milheto e o sorgo são mais produtivos no período de outono, porque o clima, apesar de seco, é quente, favorecendo as espécies tropicais. Em regiões com esta condição, o sorgo é muito utilizado para a produção de grãos, sendo recente sua utilização para a produção de palha e forragem. Pela sua tolerância a déficit hídrico e a baixas temperaturas, a cultura vem ganhando importância econômica no Estado. Este estudo teve como objetivo selecionar genótipos de sorgo para pastejo na safra de outono/inverno, em sucessão a soja.bitstream/item/38771/1/BP-200416.pd

    Traps for pinning and scattering of antiferromagnetic skyrmions via magnetic properties engineering

    Full text link
    Micromagnetic simulations have been performed to investigate the controllability of the skyrmion position in antiferromagnetic nanotracks with their magnetic properties modified spatially. In this study we have modeled magnetic defects as local variations on the material parameters, such as the exchange stiffness, saturation magnetization, perpendicular magnetocrystalline anisotropy and Dzyaloshinskii-Moriya constant. Thus, we have observed not only pinning (potential well) but also scattering (potential barrier) of antiferromagnetic skyrmions, when adjusting either a local increase or a local reduction for each material parameter. In order to control of the skyrmion motion it is very important to impose certain positions along the nanotrack where the skyrmion can stop. Magnetic defects incorporated intentionally in antiferromagnetic racetracks can be useful for such purpose. In order to provide guidelines for experimental studies, we vary both material parameters and size of the modified region. The found results show that the efficiency of skyrmion trap depends on a suitable combination of magnetic defect parameters. Furthermore, we discuss the reason why skyrmions are either attracted or repelled by a region magnetically modified.Comment: arXiv admin note: substantial text overlap with arXiv:1810.0375

    Complex solitons with real energies

    Get PDF
    Using Hirota’s direct method and Bäcklund transformations we construct explicit complex one and two-soliton solutions to the complex Korteweg-de Vries equation, the complex modified Korteweg-de Vries equation and the complex sine-Gordon equation. The one-soliton solutions of trigonometric and elliptic type turn out to be PT -symmetric when a constant of integration is chosen to be purely imaginary with one special choice corresponding to solutions recently found by Khare and Saxena. We show that alternatively complex PT -symmetric solutions to the Korteweg-de Vries equation may also be constructed alternatively from real solutions to the modified Korteweg-de Vries by means of Miura transformations. The multi-soliton solutions obtained from Hirota’s method break the PT -symmetric, whereas those obtained from Bäcklund transformations are PT -invariant under certain conditions. Despite the fact that some of the Hamiltonian densities are non-Hermitian, the total energy is found to be positive in all cases, that is irrespective of whether they are PT -symmetric or not. The reason is that the symmetry can be restored by suitable shifts in space-time and the fact that any of our N-soliton solutions may be decomposed into N separate PT -symmetrizable one-soliton solutions

    Selection of alfafa cultivars adapted for tropical environments with repeated measures using PROC MIXED of SAS system.

    Get PDF
    Although alfalfa (Medicago sativa L.) is a leguminous herbage widely used in temperate regions as animal feed, there is not much research in tropical regions to develop cultivars adapted to these environmental conditions. The utilization of adapted cultivars with adequate management practices is important to improve productivity, quality and persistence of cultivated pastures. The objectives of this study were to verify the genetic variability among alfalfa cultivars and to rank them using mixed model methodology. A total of 35 alfalfa cultivars were evaluated in the rainy and dry seasons, from 1996 to 2000, in plots of 2.8 m2 in Sertãozinho, São Paulo, Brazil. The experimental design was a randomized complete block with three replications. Longitudinal data of dry matter yield were analyzed using PROC MIXED of SAS® System. Several covariance structures were tested and the spherical spatial structure was selected. The results show that the genetic variability was statistically significant only for the dry season. Moreover, the interaction among cultivars and harvests variance was highly significant for both seasons. The empirical best linear unbiased predictions of cultivar effects were obtained, allowing for the selection of the superior cultivars MH 15, 5715, SW 8210, Rio, High, 5888, Monarca, Victoria, Florida 77 and Falcon. Crioula, the most common cultivar in Brazil, showed low forage potential in Sertãozinho. Results indicate potential for use of more productive cultivars of alfalfa to produce animal feed in tropical environments

    Rodrigues, M. O. (2020) Lisboa: Lisbon International Press. ISBN, 978-989-52-8189-3, 114 pp.

    Get PDF
    UIDB/04647/2020 UIDP/04647/2020publishersversionpublishe

    Collins, P. H., & Bilges, S. (2021). Interseccionalidade. Boitempo, (287 pp.)

    Get PDF
    UIDB/04647/2020 UIDP/04647/2020publishersversionpublishe

    Supersymmetric Many-particle Quantum Systems with Inverse-square Interactions

    Full text link
    The development in the study of supersymmetric many-particle quantum systems with inverse-square interactions is reviewed. The main emphasis is on quantum systems with dynamical OSp(2|2) supersymmetry. Several results related to exactly solved supersymmetric rational Calogero model, including shape invariance, equivalence to a system of free superoscillators and non-uniqueness in the construction of the Hamiltonian, are presented in some detail. This review also includes a formulation of pseudo-hermitian supersymmetric quantum systems with a special emphasis on rational Calogero model. There are quite a few number of many-particle quantum systems with inverse-square interactions which are not exactly solved for a complete set of states in spite of the construction of infinitely many exact eigen functions and eigenvalues. The Calogero-Marchioro model with dynamical SU(1,1|2) supersymmetry and a quantum system related to short-range Dyson model belong to this class and certain aspects of these models are reviewed. Several other related and important developments are briefly summarized.Comment: LateX, 65 pages, Added Acknowledgment, Discussions and References, Version to appear in Jouranl of Physics A: Mathematical and Theoretical (Commissioned Topical Review Article

    The Echinococcus canadensis (G7) genome: A key knowledge of parasitic platyhelminth human diseases

    Get PDF
    Background: The parasite Echinococcus canadensis (G7) (phylum Platyhelminthes, class Cestoda) is one of the causative agents of echinococcosis. Echinococcosis is a worldwide chronic zoonosis affecting humans as well as domestic and wild mammals, which has been reported as a prioritized neglected disease by the World Health Organisation. No genomic data, comparative genomic analyses or efficient therapeutic and diagnostic tools are available for this severe disease. The information presented in this study will help to understand the peculiar biological characters and to design species-specific control tools. Results: We sequenced, assembled and annotated the 115-Mb genome of E. canadensis (G7). Comparative genomic analyses using whole genome data of three Echinococcus species not only confirmed the status of E. canadensis (G7) as a separate species but also demonstrated a high nucleotide sequences divergence in relation to E. granulosus (G1). The E. canadensis (G7) genome contains 11,449 genes with a core set of 881 orthologs shared among five cestode species. Comparative genomics revealed that there are more single nucleotide polymorphisms (SNPs) between E. canadensis (G7) and E. granulosus (G1) than between E. canadensis (G7) and E. multilocularis. This result was unexpected since E. canadensis (G7) and E. granulosus (G1) were considered to belong to the species complex E. granulosus sensu lato. We described SNPs in known drug targets and metabolism genes in the E. canadensis (G7) genome. Regarding gene regulation, we analysed three particular features: CpG island distribution along the three Echinococcus genomes, DNA methylation system and small RNA pathway. The results suggest the occurrence of yet unknown gene regulation mechanisms in Echinococcus. Conclusions: This is the first work that addresses Echinococcus comparative genomics. The resources presented here will promote the study of mechanisms of parasite development as well as new tools for drug discovery. The availability of a high-quality genome assembly is critical for fully exploring the biology of a pathogenic organism. The E. canadensis (G7) genome presented in this study provides a unique opportunity to address the genetic diversity among the genus Echinococcus and its particular developmental features. At present, there is no unequivocal taxonomic classification of Echinococcus species; however, the genome-wide SNPs analysis performed here revealed the phylogenetic distance among these three Echinococcus species. Additional cestode genomes need to be sequenced to be able to resolve their phylogeny.Fil: Maldonado, Lucas Luciano. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Assis, Juliana. Fundación Oswaldo Cruz; BrasilFil: Gomes Araújo, Flávio M.. Fundación Oswaldo Cruz; BrasilFil: Salim, Anna C. M.. Fundación Oswaldo Cruz; BrasilFil: Macchiaroli, Natalia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Cucher, Marcela Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Camicia, Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Fox, Adolfo. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Rosenzvit, Mara Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; ArgentinaFil: Oliveira, Guilherme. Instituto Tecnológico Vale; Brasil. Fundación Oswaldo Cruz; BrasilFil: Kamenetzky, Laura. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones en Microbiología y Parasitología Médica. Universidad de Buenos Aires. Facultad de Medicina. Instituto de Investigaciones en Microbiología y Parasitología Médica; Argentin
    corecore