A ferrugem da teca no Amazonas.

Objetiva-se relatar a ocorrência da doença no Amazonas. Em pequenos plantios de teca, um situado no parque de exposição agropecuária (Rod. AM 010, Km 13) e outro na estação experimental da Ceplac, (Rod. BR 174, Km 48), ambas em Manaus, observou-se intenso desfolhamento. A doença causa desfolha prematura em todas as fases fenológicas da cultura.Resumo:57-1

Mites (Acari: Mesostigmata, Sarcoptiformes and Trombidiformes) associated to soybean in Brazil, including new records from the Cerrado areas.

In Brazil, soybean Glycine max (L.) Merril crops are subjected to incidence of several pests, which are mainly insect species. However, the occurrences of other pest species are growing. In this context, outbreaks of phytophagous mites are becoming more frequent. Nevertheless, records of mites in such crop are available only for Maranhão, Mato Grosso, Minas Gerais and Rio Grande do Sul states. Thus, this work gathers all information published about the diversity of mites found in soybean in Brazil, and also new records of mite species made on samplings taken from the central Cerrado area. In the whole, occurrence of 44 species of plant mites in soybean has been recorded in Brazil. Data from prior studies and the results of this work present the tetranychid Mononychellus planki (McGregor) as the mite species most frequently occurring in the Brazilian soybean crops. A large portion of Phytoseiidae species has occurred in crops from Rio Grande do Sul state. In addition, spontaneous soybean has hosted almost half of the phytoseiid species sampled in Cerrado region. High diversity of Tarsonemidae has been found in the cultivated soybean. More studies about soybean mites are needed to clarify the damage potential of phytophagous mites and the biological role of predatory mites in this crop. RESUMO: No Brasil, lavouras de soja Glycine max (L.) Merril estão sujeitas a incidência de várias pragas, as quais são principalmente espécies de insetos. No entanto, a ocorrência de outras espécies-praga tem aumentado. Neste contexto, surtos populacionais de ácaros fitófagos têm se tornado mais frequentes. Apesar disso, os registros de ácaros para esta cultura estão disponíveis apenas para os estados de Maranhão, Mato Grosso, Minas Gerais e Rio Grande do Sul. Assim, este trabalho agrega toda a informação publicada sobre a diversidade de ácaros encontrados em soja no Brasil, além de novos registros feitos através de amostragens na região central do Cerrado. No total, 44 espécies de ácaros foram registradas em soja no Brasil. Dados de estudos anteriores, somados aos resultados deste trabalho, apresentam o tetraniquídeo Mononychellus planki (McGregor) como a espécie de ácaro mais frequente em lavouras de soja brasileiras. Considerável número de espécies de Phytoseiidae tem ocorrido nas lavouras amostradas do Rio Grande do Sul. Além disso, a soja espontânea abrigou quase metade das espécies de fitoseídeos amostrados na região central do Cerrado. Por sua vez, uma elevada diversidade de Tarsonemidae foi encontrada na soja cultivada. Mais estudos sobre ácaros em soja são necessários para esclarecer o potencial de dano dos ácaros fitófagos e o papel biológico dos ácaros predadores nesta cultura

Variational Deep Semantic Hashing for Text Documents

As the amount of textual data has been rapidly increasing over the past decade, efficient similarity search methods have become a crucial component of large-scale information retrieval systems. A popular strategy is to represent original data samples by compact binary codes through hashing. A spectrum of machine learning methods have been utilized, but they often lack expressiveness and flexibility in modeling to learn effective representations. The recent advances of deep learning in a wide range of applications has demonstrated its capability to learn robust and powerful feature representations for complex data. Especially, deep generative models naturally combine the expressiveness of probabilistic generative models with the high capacity of deep neural networks, which is very suitable for text modeling. However, little work has leveraged the recent progress in deep learning for text hashing. In this paper, we propose a series of novel deep document generative models for text hashing. The first proposed model is unsupervised while the second one is supervised by utilizing document labels/tags for hashing. The third model further considers document-specific factors that affect the generation of words. The probabilistic generative formulation of the proposed models provides a principled framework for model extension, uncertainty estimation, simulation, and interpretability. Based on variational inference and reparameterization, the proposed models can be interpreted as encoder-decoder deep neural networks and thus they are capable of learning complex nonlinear distributed representations of the original documents. We conduct a comprehensive set of experiments on four public testbeds. The experimental results have demonstrated the effectiveness of the proposed supervised learning models for text hashing.Comment: 11 pages, 4 figure

Yield response factor (KY) for winter corn crop in the region of Dourados, MS, Brazil.

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Theory for phonon pumping by magnonic spin currents

In recent years several experimental observations and theoretical predictions of unique phenomena involving the interplay between spin currents and the coupled magnetization-elastic dynamics have invigorated the field of spintronics. One important experiment reported several years ago showed that elastic waves can produce spin pumping, that is, generation of spin currents in a metallic film in contact with a ferromagnetic material. Very recently the Onsager reciprocal of this effect has been observed in samples made of a film of the insulating ferrimagnet yttrium iron garnet in contact with a platinum strip with nanoscopic silver particles that is known to exhibit a giant spin Hall effect. By passing an electric current through the metallic strip, the spin current generated by the spin Hall effect produces a large magnonic spin current that excites phonons with microwave frequency, observed by Brillouin light scattering. Here we show that these experiments are explained by a theory based on a process in which one magnon in the spin current creates one phonon and another magnon, with conservation of energy and momentum. The theoretical value of the critical charge current in the metallic strip necessary to drive phonons and the values of the phonon frequencies are in good agreement with the values measured experimentally

Patogenicidade de Metarhizium anisopliae a ovos e ninfas de Tibraca limbativentris (Heteroptera: pentatomidae).

Foi avaliado o efeito do Metarhizium anisopliae isolado CG 168 sobre ovos e ninfas do 1 e 2 instares do percevejo-do-colmo, Tibraca limbativentris, praga importante do arroz irrigado no Brasil

Estudo da viabilidade prática e econômica do adensamento do plantio associado com a erradicação sistemática de plantas com mosaico no controle do endurecimento dos frutos do maracujazeiro no estado do Pará.

Projeto

NITROGEN FERTILIZATION AND INOCULATION OF COMMON BEAN WITH \u3ci\u3eRhizobium tropici\u3c/i\u3e

INTRODUCTION Common bean (Phaseolus vulgaris L.) has a great importance as a food crop worldwide and Brazil has a production about 3.29 million tons (FAO, 2014). Nitrogen (N) is the nutrient most absorbed and extracted by common bean and its use has a significant influence on yield. Due to the high cost of nitrogen fertilizers and the losses of this nutrient in the soil, which contributes to environmental pollution, it is of great interest to search for techniques that can maximize its efficiency. Although bean plants have the capacity to establish mutual symbiosis with bacteria, biotic and abiotic factors can act to reduce the efficiency of this relationship. This study aimed at evaluating the efficiency of inoculation practice with rhizobia and doses of nitrogen on production components of common bean

Determinação do comprimento ótimo de transectos para estimativa de necromassa floresta.

O objetivo deste trabalho foi avaliar diferentes comprimentos de transecto para determinação da necromassa florestal caída sobre o chão. Os dados são provenientes de transectos de 10 metros, medidos durante o teste de metodologia do Inventário Florestal Nacional na Amazônia, Cerrado e Caatinga, e no inventário em Santa Catarina, representando Floresta Ombrófila Mista e Floresta Estacional Decidual. O comparativo do coeficiente de variação, para transectos de 10 a 150 m indica que as maiores alterações desse estimador ocorrem no intervalo de 10 até 50 m, estabilizando-se a partir deste comprimento. A adoção de transectos de 10 m nas tipologias avaliadas é recomendável, pois com este comprimento ocorre uma redução de 35% na distância total de caminhamento em relação aos transectos de 20 m, para obter o mesmo erro amostral.Nota Científic