Imagery and long-slit spectroscopy of the Polar-Ring Galaxy AM2020-504

Interactions between galaxies are very common. There are special kinds of interactions that produce systems called Polar Ring Galaxies (PRGs), composed by a lenticular, elliptical, or spiral host galaxy, surrounded by a ring of stars and gas, orbiting in an approximately polar plane. The present work aims to study AM2020-504, a PRG with an elliptical host galaxy, and a narrow and well defined ring, probably formed by accretion of material from a donor galaxy, collected by the host galaxy. Our observational study was based on BVRI broad band imagery as well as longslit spectroscopy in the wavelenght range 4100--8600\AA, performed at the 1.6m telescope at the Observat\'orio do Pico dos Dias (OPD), Brazil. We estimated a redshift of z= 0.01683, corresponding a heliocentric radial velocity of 5045 +/-23 km/s. The (B-R) color map shows that the ring is bluer than the host galaxy, indicating that the ring is a younger structure. Standard diagnostic diagrams were used to classify the main ionizing source of selected emission-line regions (nucleus, host galaxy and ring). It turns out that the ring regions are mainly ionized by massive stars while the nucleus presents AGN characteristics. Using two empirical methods, we found oxygen abundances for the HII regions located in the ring in the range 12+log(O/H)=8.3-8.8 dex, the presence of an oxygen gradient across the ring, and that AM2020-504 follows the metallicity-luminosity relation of spiral galaxies. These results support the accretion scenario for this object and rules out cold accretion as source for the HI gas in the polar ring

Alterações na fertilidade dos solos em áreas de produção familiar de mandioca no Território do Alto Sertão de Alagoas.

O Território do Alto Sertão de Alagoas, também conhecido como Xingó, é formado por oito municípios (Água Branca, Canapi, Delmiro Gouveia, Inhapi, Mata Grande, Olho D?Água do Casado, Pariconha e Piranhas). Esse território possui uma população estimada de 167.660 habitantes (IBGE, 2007), faz divisa com os estados de Sergipe, Bahia e Pernambuco, perfazendo uma área de 3.905,4 km2.bitstream/item/122986/1/Alteracoes-na-fertilidade-COT-89-On-line.pd

Recording from two neurons: second order stimulus reconstruction from spike trains and population coding

We study the reconstruction of visual stimuli from spike trains, recording simultaneously from the two H1 neurons located in the lobula plate of the fly Chrysomya megacephala. The fly views two types of stimuli, corresponding to rotational and translational displacements. If the reconstructed stimulus is to be represented by a Volterra series and correlations between spikes are to be taken into account, first order expansions are insufficient and we have to go to second order, at least. In this case higher order correlation functions have to be manipulated, whose size may become prohibitively large. We therefore develop a Gaussian-like representation for fourth order correlation functions, which works exceedingly well in the case of the fly. The reconstructions using this Gaussian-like representation are very similar to the reconstructions using the experimental correlation functions. The overall contribution to rotational stimulus reconstruction of the second order kernels - measured by a chi-squared averaged over the whole experiment - is only about 8% of the first order contribution. Yet if we introduce an instant-dependent chi-square to measure the contribution of second order kernels at special events, we observe an up to 100% improvement. As may be expected, for translational stimuli the reconstructions are rather poor. The Gaussian-like representation could be a valuable aid in population coding with large number of neurons

Social wasps are effective biocontrol agents of key lepidopteran crop pests

Biocontrol agents can help reduce pest populations as part of an integrated pest management scheme, with minimal environmental consequences. However, biocontrol agents are often non-native species and require significant infrastructure; overuse of single agents results in pest resistance. Native biocontrol agents are urgently required for more sustainable multi-faceted approaches to pest management. Social wasps are natural predators of lepidopteran pests, yet their viability as native biocontrol agents is largely unknown. Here, we provide evidence that the social paper wasp Polistes satan is a successful predator on the larvae of two economically important and resilient crop pests, the sugarcane borer Diatraea saccharalis (on sugarcane Saccharum spp.) and the fall armyworm Spodoptera frugiperda (on maize Zea mays); P. satan wasps significantly reduce crop pest damage. These results provide the much-needed baseline experimental evidence that social wasps have untapped potential as native biocontrol agents for sustainable crop production and food security

Levantamento da diversidade de vírus em batata-doce do banco ativo de germoplasma da Embrapa Hortaliças.

O presente trabalho teve o objetivo de ralizar um levantamento de vírus no Banco Ativo de Germoplasma de batata-doce da Embrapa Hortaliças

Manejo das principais doenças do milho.

bitstream/CNPMS/20484/1/Circ_92.pd

Levantamento da diversidade de vírus em batata-doce no campo experimental da Embrapa Hortaliças

O presente trabalho teve o objetivo de realizar um levantamento de vírus no Campo Experimental de Batata-doce para a análise que consistiu inicialmente na enxertia na planta indicadora Ipomoea stosa e posterior detecção viral pela técnica NCM-Elisa para dez virus que infectam a batata-doce: Sweet potato feathery mottle virus (SPMMV), Sweet potato virus G (SPVG), Sweet potato C-6.Resumo expandido

Aplicação de dejetos suínos na produção de Tifton 85 em assentamento rural, São Gabriel do Oeste, MS.

Este trabalho teve por objetivo avaliar o crescimento do Tifton 85, com diferentes doses de dejetos suínos, em uma pequena propriedade rural no Assentamento Campanário, no município de São Gabriel do Oeste, MS. Os trabalhos de pesquisa desenvolvidos na área de manejo de dejetos da suinocultura indicam que nenhum tratamento em uso no Brasil permite que o resíduo final seja lançado diretamente nos cursos d?água.bitstream/item/79856/1/COT84.pd

Sistema de cultivo em aléias nos tabuleiros costeiros de Sergipe: resultados de pesquisa.

bitstream/item/32011/1/doc-161.pd