Symptoms of mineral deficiencies in cupuaçu plants (Theobroma grandiflorum) grown in nutrient solution

Com a finalidade de induzir os sintomas visuais de deficiência nutricional no cupuaçuzeiro, realizou-se em casa de vegetação, um experimento com solução nutritiva onde omitiu-se os seguintes elementos: N, P, K, Ca, Mg, S, B, Cu, Fe, Mu e Zn. Um tratamento completo serviu de comparação. Todos os sintomas foram caracterizados e apresentaram semelhanças com os observados para o cacaueiro, sendo relacionados em tabela para a identificação. Para determinar as concentrações de nutrientes, foram coletadas folhas em diversas partes da planta e em duas épocas de amostragem. Os teores encontrados nas folhas em que o elemento foi omitido foram sempre inferiores daqueles encontrados no tratamento completo, demonstrando que os sintomas descritos foram realmente devidos ao efeito da omissão. Embora os teores apresentados nas folhas com sintomas de deficiência tenham sido sempre menores que os obtidos nas demais amostragens, a folha de referência indicada pela literatura para o cacaueiro (3ª a partir do ápice), mostrou-se adequada para identificar deficiências nutricionais no cupuaçuzeiro, exceto para o cobre.With the objective of obtaining the visual symptoms of cupuaçu nutricional deficiencies, seedlings were grown in a greenhouse, in nutrient solution, omitting N, P, K, Ca, Mg, S, B, Cu, Fe, Mn and Zn, in comparison to a complete treatment. All symptoms were described and presented as an identification table, which shows great similarity with cocoa plants. To asses nutrient concentrations, leaves were collected at different parts of the plants, in two samplings. Concentrations found in leaves from plants in which an dement was omitted were always lower than those found in the complete treatment, thereby demonstrating that the symptoms were really due to the induced deficiency. Although the mineral contents of leaves with deficiency symptoms were always lower than those found in other samplings, the reference leaf, recommended in the literature for cocoa (3rd leaf starting from tip), was also adequate for cupuaçu, except in the case of Cu

Quantum walks: a comprehensive review

Quantum walks, the quantum mechanical counterpart of classical random walks, is an advanced tool for building quantum algorithms that has been recently shown to constitute a universal model of quantum computation. Quantum walks is now a solid field of research of quantum computation full of exciting open problems for physicists, computer scientists, mathematicians and engineers. In this paper we review theoretical advances on the foundations of both discrete- and continuous-time quantum walks, together with the role that randomness plays in quantum walks, the connections between the mathematical models of coined discrete quantum walks and continuous quantum walks, the quantumness of quantum walks, a summary of papers published on discrete quantum walks and entanglement as well as a succinct review of experimental proposals and realizations of discrete-time quantum walks. Furthermore, we have reviewed several algorithms based on both discrete- and continuous-time quantum walks as well as a most important result: the computational universality of both continuous- and discrete- time quantum walks.Comment: Paper accepted for publication in Quantum Information Processing Journa