Fracionamento de diferentes classes de compostos químicos por cromatografia líquida em coluna.

Resumo

Estimativas de parâmetros genéticos para características reprodutivas e de crescimento em bovinos da raça Canchim.

Estudou-se neste trabalho dados referentes às características de idade ao segundo parto (ISP), perímetro escrotal aos 420 dias de idade (PE420) e peso aos 420 dias de idade de machos e fêmeas (P420) de animais da raça Canchim, para as quais foram obtidas estimativas de herdabilidade e correlações genéticas. No modelo animal, foram incluídos os efeitos fixos de grupo de contemporâneos e os efeitos aleatórios aditivos diretos e residuais. Utilizou-se o método da máxima verossimilhança restrita em análise bi-característica. As médias de ISP, PE420 e P420 foram iguais a 57,07±8,69 meses, 24,63±3,84 cm e 260,37±46,5l kg, respectivamente. As estimativas de herdabilidade foram 0,07±0,01, 0,2l±0,05 e 0,24±0,03, respectivamente para ISP, PE420 e P420. As correlações genéticas foram iguais a -0,47 (ISPXPE420) e 0,10 (ISPxP420). A seleção direta para perímetro escrotal aos 420 dias de idade poderá resultar em progresso genético favoráveis na assiduidade reprodutiva de fêmeas da raça Canchim, considerando que o PE420 apresentou correlação genética aditiva com idade ao segundo parto

ITS-rDNA phylogeny of Colletotrichum spp. causal agent of apple glomerella leaf spot.

Several diseases have affected apple production, among them there is Glomerella leaf spot (GLS) caused by Colletotrichum spp. The first report of this disease in apple was in plants nearby citrus orchards in São Paulo State, Brazil. The origin of this disease is still not clear, and studies based on the molecular phylogeny could relate the organisms evolutionarily and characterize possible mechanisms of divergent evolution. The amplification of 5.8S-ITS (Internal Transcribed Spacer) of rDNA of 51 pathogenic Colletotrichum spp. isolates from apples, pineapple guava and citrus produced one fragment of approximately 600 bases pairs (bp) for all the isolates analyzed. The amplified fragments were cleaved with restriction enzymes, and fragments from 90 to 500bp were obtained. The sequencing of this region allowed the generation of a phylogenetic tree, regardless of their hosts, and 5 isolated groups were obtained. From the "in silico" comparison, it was possible to verify a variation from 93 to 100% of similarity between the sequences studied and the Genbank data base. The causal agent of GLS is nearly related (clustered) to isolates of pineapple guava and to the citrus isolates used as control

Estimativas de componentes de variância e herdabilidade para características reprodutivas e de crescimento em bovinos da raça Canchim.

Estudou-se neste trabalho dados referentes às características de idade ao primeiro parto (lPP), idade ao segundo parto (ISP), perímetro escrotal aos 420 dias de idade (PE420) e peso aos 420 dias de idade de machos e fêmeas (P420) de animais da raça Canchim, para as quais foram obtidas estimativas de herdabilidade. No modelo animal, foram incluídos os efeitos fixos de grupo de contemporâneos e os efeitos aleatórios aditivos diretos e residuais. Empregou-se o método da máxima verossimilhança restrita em análise uni-característica. As médias observadas de IPP, ISP, PE420 e P420 foram iguais a 39,47±7,20 meses, 57,08±8,79 meses, 24,63±3,84 cm e 260,37±46,5l kg, respectivamente. As herdabilidades foram iguais a 0,03±0,Ol, 0,07±0,Ol, 0,22±0,05 e 0,24±0,03 para IPP, ISP, PE420 e P420, respectivamente. Dentre as características reprodutivas e de crescimento estudadas o perímetro escrotal e o peso aos 420 dias de idade apresentaram estimativas de herdabilidade de moderada magnitude, indicando que a seleção para estas características poderá contribuir para o melhoramento genético da raça Canchim

Anomalous relaxation of coarsening foams with viscoelastic continuous phases

We investigate the ultraslow structural relaxation of ageing foams with rheologically tunable continuous phases. We probe the bubble dynamics associated with pressure-driven foam coarsening using differential dynamic microscopy, which allows characterising the sample dynamics in reciprocal space with imaging experiments. Similar to other out-of-equilibrium jammed soft systems, these foams exhibit compressed exponential relaxations, with a ballistic-like linear dependency of the relaxation rate on the scattering wavevector. By tuning the rheology of the continuous phase, we observe changes in the relaxation shape, where stiffer matrices yield larger compression exponents. Our results corroborate recent real-space observations obtained using bubble tracking, providing a comprehensive overview of structural relaxation in these complex systems, both in direct and reciprocal space

A point mutation in cpsE renders Streptococcus pneumoniae nonencapsulated and enhances its growth, adherence and competence.

BACKGROUND: The polysaccharide capsule is a major virulence factor of the important human pathogen Streptococcus pneumoniae. However, S. pneumoniae strains lacking capsule do occur. RESULTS: Here, we report a nasopharyngeal isolate of Streptococcus pneumoniae composed of a mixture of two phenotypes; one encapsulated (serotype 18C) and the other nonencapsulated, determined by serotyping, electron microscopy and fluorescence isothiocyanate dextran exclusion assay.By whole genome sequencing, we demonstrated that the phenotypes differ by a single nucleotide base pair in capsular gene cpsE (C to G change at gene position 1135) predicted to result in amino acid change from arginine to glycine at position 379, located in the cytoplasmic, enzymatically active, region of this transmembrane protein. This SNP is responsible for loss of capsule production as the phenotype is transferred with the capsule operon. The nonencapsulated variant is superior in growth in vitro and is also 117-fold more adherent to and more invasive into Detroit 562 human epithelial cells than the encapsulated variant.Expression of six competence pathway genes and one competence-associated gene was 11 to 34-fold higher in the nonencapsulated variant than the encapsulated and transformation frequency was 3.7-fold greater. CONCLUSIONS: We identified a new single point mutation in capsule gene cpsE of a clinical S. pneumoniae serotype 18C isolate sufficient to cause loss of capsule expression resulting in the co-existence of the encapsulated and nonencapsulated phenotype. The mutation caused phenotypic changes in growth, adherence to epithelial cells and transformability. Mutation in capsule gene cpsE may be a way for S. pneumoniae to lose its capsule and increase its colonization potential

Primeiro registro de Diaphorina citri Kuwayama, 1908 (Hemiptera: Liviidade) para o estado de Roraima, Brasil.

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Linear Predictability vs. Bull and Bear Market Models in Strategic Asset Allocation Decisions: Evidence from UK Data

Most papers in the portfolio choice literature have examined linear predictability frameworks based on the idea that simple but flexible Vector Autoregressive (VAR) models can be expanded to produce portfolio allocations that hedge against the bull and bear dynamics typical of financial markets through careful selection of predictor variables that capture business cycles and market sentiment. Yet, a distinct literature exists that shows that nonlinear econometric frameworks, such as Markov switching, are also natural tools to compute optimal portfolios arising from the existence of good and bad market states. This paper examines whether and how simple VARs can produce portfolio rules similar to those obtained under a simple Markov switching, by studying the effects of expanding both the order of the VAR and the number/selection of predictor variables included. In a typical stock-bond strategic asset allocation problem for U.K. data, we compute the out-of-sample certainty equivalent returns for a wide range of VARs and compare these measures of performance with those of nonlinear models. We conclude that most VARs cannot produce portfolio rules, hedging demands, or (net of transaction costs) out-of-sample performances that approximate those obtained from equally simple nonlinear frameworks