472 research outputs found

    Reação de genótipos de abacaxizeiro ao nematoide Pratylenchus Brachyurus.

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    Os fitonematoides são considerados um dos principais fatores limitantes ao cultivo do abacaxizeiro. Estes patógenos causam danos consideráveis às raízes das plantas, diminuindo a eficiência das adubações pela redução da absorção de nutrientes. As plantas apresentam sistema radicular reduzido, folhas cloróticas, estreitas e de tamanho reduzido. Consequentemente, a produção é retardada e com frutos de baixo peso e valor comercial reduzido (Arieira et al., 2008)

    The Infertility-Related Stress Scale: Validation of a Brazilian–Portuguese Version and Measurement Invariance Across Brazil and Italy

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    Infertility constitutes an essential source of stress in the individual and couple's life. The Infertility-Related Stress Scale (IRSS) is of clinical interest for exploring infertility-related stress affecting the intrapersonal and interpersonal domains of infertile individuals' lives. In the present study, the IRSS was translated into Brazilian-Portuguese, and its factor structure, reliability, and relations to sociodemographic and infertility-related characteristics and depression were examined. A sample of 553 Brazilian infertile individuals (54.2% female, mean aged 36 ± 6 years) completed the Brazilian-Portuguese IRSS (IRSS-BP), and a subsample of 222 participants also completed the BDI-II. A sample of 526 Italian infertile individuals (54.2% female, mean aged 38 ± 6 years) was used to test for the IRSS measurement invariance across Brazil and Italy. Results of exploratory structural equation modeling (ESEM) indicated that a bifactor solution best represented the structure underlying the IRSS-BP. Both the general and the two specific intrapersonal and interpersonal IRSS-BP factors showed satisfactory levels of composite reliability. The bifactor ESEM solution replicated well across countries. As evidence of relations to other variables, female gender, a longer duration of infertility, and higher depression were associated with higher scores in global and domain-specific infertility-related stress. The findings offer initial evidence of validity and reliability of the IRSS-BP, which could be used by fertility clinic staff to rapidly identify patients who need support to deal with the stressful impact of infertility in the intrapersonal and interpersonal life domains, as recommended by international guidelines for routine psychosocial care in infertility settings

    A Bound Quantum Particle in a Riemann-Cartan space with Topological Defects and Planar Potential

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    Starting from a continuum theory of defects, that is the analogous to three-dimensional Einstein-Cartan-Sciama-Kibble gravity, we consider a charged particle with spin 1/2 propagating in a uniform magnetic field coincident with a wedge dispiration of finite extent. We assume the particle is bound in the vicinity of the dispiration by long range attractive (harmonic) and short range (inverse square) repulsive potentials. Moreover, we consider the effects of spin-torsion and spin-magnetic field interactions. Exact expressions for the energy eigenfunctions and eigenvalues are determined. The limit, in which the defect region becomes singular, is considered and comparison with the electromagnetic Aharonov-Bohm effect is made.Comment: 10 page

    Fontes e modos de aplicação de fósforo na produção e nutrição mineral do milho em primeiro cultivo.

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    Com o objetivo de avaliar o efeito de fontes de P, em diferentes modos de aplicacao, sobre a producao e nutricao mineral do milho, foi conduzido um experimento em condicoes de campo, num Argissolo Vermelho tipico, textura argilosa, sob vegetacao de cerrado. Os tratamentos constituiram-se das fontes de P: superfosfato triplo, termofosfato magnesiano, fosfato reativo de Arad e fosfato de Araxa, aplicadas em area total ou no sulco de plantio, na dose 180 kg ha-1 de P2O5, considerando-se o teor total de P2O5 das fontes. Utilizou-se ainda um tratamento adicional sem aplicação de P. foram analisados os teores de nutrientes nas folhas do milho no florescimento e em diferentes partes da planta na colheita. Determinaram-se tambem a producao de materia seca da parte aerea e de graos e o acumulo de nutrientes. maiores producoes foram obtidas com as fontes mais soluveis (superfosfato triplo e termofosfato magnesiano) aplicadas em area total e com o fosfato reativo no sulco de plantio. O uso localizado de superfosfato triplo no sulco de plantio comprometeu a produtividade da cultura, provocando desordens metabolicas devido a interação P x Zn. a análise foliar no florescimento mostrou-se adequada para avaliacao do equilíbrio P/Zn no milho

    Generalised Hong-Ou-Mandel Experiments with Bosons and Fermions

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    The Hong-Ou-Mandel (HOM) dip plays an important role in recent linear optics experiments. It is crucial for quantum computing with photons and can be used to characterise the quality of single photon sources and linear optics setups. In this paper, we consider generalised HOM experiments with NN bosons or fermions passing simultaneously through a symmetric Bell multiport beam splitter. It is shown that for even numbers of bosons, the HOM dip occurs naturally in the coincidence detection in the output ports. In contrast, fermions always leave the setup separately exhibiting perfect coincidence detection. Our results can be used to verify or employ the quantum statistics of particles experimentally.Comment: 11 pages, 2 figures, more references adde
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