Morphological structure of the liver in tambaqui, Colossoma macropomum (Cuvier, 1818)

This research aimed to describe the macroscopic and microscopic liver of tambaqui, Colossoma macropomum, Teleost freshwater Family Characidae, of great economic interest for the Amazon basin. We used six juveniles aged between six month and one year, from the small holding Esteio, Alta Floresta/MT, that develops mainly fish farming. The body was photographed in situ, described macroscopically, and fragments were removed and processed by routine histological techniques through paraffin embedding and HE staining. The liver, located ventrally to the swim bladder and craniodorsally to the stomach, is brownish red and consisted of three lobes, the right lateral, the left lateral and the ventral lobe. Microscopically, the parenchyma consists of hepatocytes varying from irregular rounded hexagonal to round forms with a large and central nucleus, and arranged in linear strings limited by sinusoids and radiating to central veins, but with absence of liver lobules. The central veins are distributed throughout the parenchyma, while the portal space consists in most cases only of a hepatic vein and bile duct; elsewhere exist artery and duct. Formation of portal triads was not founde. Melano macrophages were frequently seen dispersed throughout the central parenchyma. The morphofunctional study of the digestive system of fishes of the Amazon basin is important to obtain knowledge about their weight gain, large scale production for human consumption and preservation of the species, and has also its importance for being used as bioindicators today.

Preditores da realização de consultas odontológicas de rotina e por problema em pré-escolares

OBJETIVO: Estimar a prevalência do uso de serviços odontológicos por pré- escolares e fatores associados. MÉTODOS: Estudo transversal com 1.129 crianças de cinco anos de idade da Coorte de Nascimentos de Pelotas 2004, RS, de setembro de 2009 a janeiro de 2010. Registrou-se o uso de serviço odontológico pelo menos uma vez na vida e o motivo para a primeira consulta odontológica da criança. As categorias do desfecho foram: ter feito a primeira consulta por rotina, para resolver um problema ou nunca ter ido ao dentista. Os exames bucais e as entrevistas foram realizados nos domicílios. Aspectos socioeconômicos e variáveis independentes ligadas à mãe e à criança foram analisados por meio de regressão logística multinomial. RESULTADOS: A prevalência de uso por qualquer motivo foi 37,0%. Os principais preditores para consulta de rotina foram nível econômico mais elevado, mãe com maior escolaridade e ter recebido orientação sobre prevenção. Principais preditores para consulta por problema foram ter sentido dor nos últimos seis meses, mãe com maior escolaridade e ter recebido orientação sobre prevenção. Cerca de 45,0% das mães receberam orientação de como prevenir cárie, principalmente fornecida por dentistas. Filhos de mães com história de maior aderência a programas de saúde tiveram maior probabilidade de ter feito uma consulta odontológica de rotina. CONCLUSÕES: A taxa de utilização dos serviços odontológicos por pré- escolares foi inferior às de consultas médicas (puericultura). Além da renda e da escolaridade, comportamentos maternos têm papel importante no uso por rotina. Relato de dor nos últimos seis meses e número elevado de dentes afetados por cárie, independentemente dos demais fatores, estiveram associados ao uso para resolver problema. É necessária a integração de ações de saúde bucal nos programas materno-infantis.

Urediospores of rust fungi are ice nucleation active at > -10°C and harbor ice nucleation active bacteria

Various features of the biology of the rust fungi and of the epidemiology of the plant diseases they cause illustrate the important role of rainfall in their life history. Based on this insight we have characterized the ice nucleation activity (INA) of the aerially disseminated spores (urediospores) of this group of fungi. Urediospores of this obligate plant parasite were collected from natural infections of 7 species of weeds in France, from coffee in Brazil and from field and greenhouse-grown wheat in France, the USA, Turkey and Syria. Immersion freezing was used to determine freezing onset temperatures and the abundance of ice nuclei in suspensions of washed spores. Microbiological analyses of spores from France, the USA and Brazil, and subsequent tests of the ice nucleation activity of the bacteria associated with spores were deployed to quantify the contribution of bacteria to the ice nucleation activity of the spores. All samples of spores were ice nucleation active, having freezing onset temperatures as high as −4 °C. Spores in most of the samples carried cells of ice nucleation-active strains of the bacterium Pseudomonas syringae (at rates of less than 1 bacterial cell per 100 urediospores), but bacterial INA accounted for only a small fraction of the INA observed in spore suspensions. Changes in the INA of spore suspensions after treatment with lysozyme suggest that the INA of urediospores involves a polysaccharide. Based on data from the literature, we have estimated the concentrations of urediospores in air at cloud height and in rainfall. These quantities are very similar to those reported for other biological ice nucleators in these same substrates. However, at cloud level convective activity leads to widely varying concentrations of particles of surface origin, so that mean concentrations can underestimate their possible effects on clouds. We propose that spatial and temporal concentrations of biological ice nucleators active at temperatures > −10 °C and the specific conditions under which they can influence cloud glaciation need to be further evaluated so as to understand how evolutionary processes could have positively selected for INA.