Variações ecomorfológicas e de uso de habitat em Piabina argentea (Characiformes, Characidae) da bacia do Rio das Velhas, Minas Gerais, Brasil

O presente estudo teve como objetivo investigar os padrões local e regional de uso de habitat de Piabina argentea Reinhardt, 1867 em quatro diferentes rios da bacia do rio das Velhas. Os habitat amostrados foram caracterizados quanto à velocidade da água, profundidade e tipo de substrato. Para a análise ecomorfológica, foram calculados 17 atributos ecomorfológicos de 40 exemplares de cada rio. Embora estas populações tenham se sobreposto no espaço ecomorfológico, a Análise Discriminante Canônica mostrou haver diferença significativa entre elas, principalmente da população do rio das Velhas em relação às demais. A separação se deu em termos do índice de compressão, altura relativa do corpo e índice de achatamento ventral. Os padrões locais de seleção de habitat não foram congruentes em todos os rios, mas em geral, houve predomínio do padrão regional: habitat lênticos, profundidade entre 20 e 40 cm e 60 e 80 cm e substrato areia, silte+argila e banco de folhas. Considerando as características físicas de cada rio e o padrão regional da espécie, a maior parte dos seus requerimentos de habitat é contemplada nos quatro rios. Entretanto, um corpo d'água assoreado como o trecho do rio das Velhas, tende a ter maiores velocidades da água, menores profundidades e substrato finos, o que atende em parte à seleção de habitat da espécie estudada

Effect of streptozotocin on foetal lambs in mid-pregnancy

Streptozotocin was administered to 11 foetal lambs in utero at 70–85 days of gestation. Four of the foetuses survived and, when delivered at 134–142 days, exhibited significant growth retardation of the trunk and delayed osseous maturation in limb bones. The foetal kidneys and livers were most affected, but in three of the four foetuses, the weight of the brain was appropriate for gestational age. Likewise head size, measured by length or biparietal diameter, was normal. The insulin content of the foetal pancreas was less after streptozotocin-treatment than in normal animals of a similar gestation. Two streptozotocin-treated foetuses, catheterized at 120 days gestation, had higher glucose concentrations and lower insulin responses than in controls when infused with glucose. Plasma concentrations of ovine placental lactogen were lower in streptozotocin-treated foetuses than in controls, but serum somatomedin-like activity measured by receptor assay was greater than in controls. When the foetal serum was chromatographed on Sephadex G150 at acid pH, the major increase in somatomedin-like activity was found in the smaller molecular weight fraction (molecular size about 10000). The foetal growth retardation associated with streptozotocin administration in mid-pregnancy may be due to insulin deficiency, but the normal brain weight which occurred suggests that some other factor (possibly a somatomedin) regulates the growth of this organ

Maternal and neonatal outcomes of pregnancies complicated by asthma in an Australian population

The definitive version is available at www3.interscience.wiley.comObjectiveTo determine if there are sex differences in risk and incidence of stillbirth, preterm delivery and small-for-gestational age (SGA) in pregnancies complicated by maternal asthma relative to a non-asthmatic population.Study designUnivariant and multiple regression analysis of the incidence of preterm delivery, SGA and stillbirth in singleton pregnancies complicated by asthma in Newcastle, NSW, Australia, from 1995 to 1999.ResultsAsthma complicated 12% of all singleton pregnancies. The incidence of preterm delivery was not significantly different between asthmatic (13%) and non-asthmatic (11%) pregnancies. Male fetuses (53%) were more likely to deliver preterm than female fetuses (47%) in both asthmatic and non-asthmatic populations. There were significantly more male neonates of pregnancies complicated by asthma that were SGA at term relative to those of the non-asthmatic population. There were significantly more preterm female neonates that were SGA in pregnancies complicated by asthma relative to those of the non-asthmatic population. Male fetuses were more likely to be associated with a stillbirth in pregnancies complicated by asthma than female fetuses.ConclusionThe presence of maternal asthma during pregnancy increases the risk of stillbirth for the male fetus and is associated with changes in fetal growth, but does not increase the incidence of a preterm delivery.Vicki L. Clifton, Patricia Engel, Roger Smith, Peter Gibson, Maxwell Brinsmead and Warwick B. Gile

THE SECD MACHINE ON A CHIP

We describe work completed on the design, informal specification, and layout of a custom SECD machine. The chip contains around 25,000 transistors excluding memory cells. The work is part of a long term project which aims to support specification based VLSI design, build a library of cell and sub-system specifications, and investigate algorithms for transforming from specifications to other views.We are currently acquiring citations for the work deposited into this collection. We recognize the distribution rights of this item may have been assigned to another entity, other than the author(s) of the work.If you can provide the citation for this work or you think you own the distribution rights to this work please contact the Institutional Repository Administrator at [email protected]