51 research outputs found

    An Observational Overview of Solar Flares

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    We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

    Fauna of euglossina (Hymenoptera: Apidae) from southwestern Amazonia, Acre, Brazil

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    Male orchid bees were collected between December 2005 and September 2006 in 11 forest areas of different sizes in the region of Rio Branco, Acre, Southwestern Amazonia, Brazil. The bees were attracted by 6 aromatic compounds and collected by insect nets and scent baited traps. A total of 3,675 males of Euglossina in 4 genera and 36 species were collected. Eulaema cingulata (Fabricius) was the most common (24.6%), followed by Eulaema meriana (Olivier) (14.6%), Euglossa amazonica Dressler (10.5%), Eulaema nigrita Lepeletier (10.5%) and Eulaema pseudocingulata (Oliveira) (7.2%). Cineole was the scent that attracted the greatest number of individuals (23.8%) and methyl salicylate the greatest number of species (28) for both methods of sampling. Thirty one bees of 9 species with pollinar orchid attached to their bodies were collected. The accumulative number of species stabilized after the 48th collection. Few species were abundant; the great majority were represented by less than 50 bees. The lack of standardized sample protocols limited very much the conclusions derived from comparisons among the majority of studies on Euglossina assemblages. However, the results presented here suggest that the State of Acre is very rich in those bees compared to other regions.Machos de abelhas Euglossina foram coletados entre dezembro de 2005 e setembro de 2006 em 11 ĂĄreas florestais de diferentes tamanhos na regiĂŁo de Rio Branco, Acre, AmazĂŽnia Sul-Ocidental. As abelhas foram atraĂ­das por 6 substĂąncias odorĂ­feras e coletadas com rede entomolĂłgica e armadilhas. Um total de 3.675 machos de Euglossina pertencentes a 4 gĂȘneros e 36 espĂ©cies foi coletado. Eulaema cingulata (Fabricius) foi a espĂ©cie mais comum (24,6%), seguida por Eulaema meriana (Olivier) (14,6%), Euglossa amazonica Dressler (10,5%), Eulaema nigrita Lepeletier (10,5%) e Eulaema pseudocingulata (Oliveira) (7,2%). Cineol foi a substĂąncia que atraiu maior nĂșmero de indivĂ­duos (23,8%) e metil salicilato o maior nĂșmero de espĂ©cies (28) para ambos os mĂ©todos de coleta. Foram coletados 31 indivĂ­duos pertencentes a 9 espĂ©cies portando polinĂĄrios. O nĂșmero acumulado de espĂ©cies coletadas na regiĂŁo estabilizou a partir da 48ÂȘ coleta. Poucas espĂ©cies foram abundantes, a maioria representada por menos que 50 indivĂ­duos. A falta de um protocolo amostral padronizado tem limitado comparaçÔes entre trabalhos realizados em diferentes regiĂ”es. Contudo, os resultados aqui apresentados indicam que o Acre apresenta elevada riqueza dessas abelhas
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