Specific fluorogenic substrates for neprilysin (neutral endopeptidase, EC 3.4.24.11) which are highly resistant to serine- and metalloproteases

Two intramolecularly quenched fluorogenic peptides containing o-aminobenzoyl (Abz) and ethylenediamine 2,4-dinitrophenyl (EDDnp) groups at amino- and carboxyl-terminal amino acid residues, Abz-DArg-Arg-Leu-EDDnp (Abz-DRRL-EDDnp) and Abz-DArg-Arg-Phe-EDDnp (Abz-DRRF-EDDnp), were selectively hydrolyzed by neutral endopeptidase (NEP, enkephalinase, neprilysin, EC 3.4.24.11) at the Arg-Leu and Arg-Phe bonds, respectively. The kinetic parameters for the NEP-catalyzed hydrolysis of Abz-DRRL-EDDnp and Abz-DRRF-EDDnp were Km = 2.8 µM, kcat = 5.3 min-1, kcat/Km = 2 min-1 µM-1 and Km = 5.0 µM, kcat = 7.0 min-1, kcat/Km = 1.4 min-1 µM-1, respectively. The high specificity of these substrates was demonstrated by their resistance to hydrolysis by metalloproteases [thermolysin (EC 3.4.24.2), angiotensin-converting enzyme (ACE; EC 3.4.24.15)], serineproteases [trypsin (EC 3.4.21.4), a-chymotrypsin (EC 3.4.21.1)] and proteases present in tissue homogenates from kidney, lung, brain and testis. The blocked amino- and carboxyl-terminal amino acids protected these substrates against the action of aminopeptidases, carboxypeptidases and ACE. Furthermore, DR amino acids ensured total protection of Abz-DRRL-EDDnp and Abz-DRRF-EDDnp against the action of thermolysin and trypsin. Leu-EDDnp and Phe-EDDnp were resistant to hydrolysis by a-chymotrypsin. The high specifity of these substrates suggests their use for specific NEP assays in crude enzyme preparationsUniversidade Federal do CearáUniversité de MontréalUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Exploring the temporal structure of heterochronous sequences using TempEst (formerly Path-O-Gen)

Gene sequences sampled at different points in time can be used to infer molecular phylogenies on a natural timescale of months or years, provided that the sequences in question undergo measurable amounts of evolutionary change between sampling times. Data sets with this property are termed heterochronous and have become increasingly common in several fields of biology, most notably the molecular epidemiology of rapidly evolving viruses. Here we introduce the cross-platform software tool, TempEst (formerly known as Path-O-Gen), for the visualization and analysis of temporally sampled sequence data. Given a molecular phylogeny and the dates of sampling for each sequence, TempEst uses an interactive regression approach to explore the association between genetic divergence through time and sampling dates. TempEst can be used to (1) assess whether there is sufficient temporal signal in the data to proceed with phylogenetic molecular clock analysis, and (2) identify sequences whose genetic divergence and sampling date are incongruent. Examination of the latter can help identify data quality problems, including errors in data annotation, sample contamination, sequence recombination, or alignment error. We recommend that all users of the molecular clock models implemented in BEAST first check their data using TempEst prior to analysis

Storage Root of Cassava: Morphological Types, Anatomy, Formation, Growth, Development and Harvest Time

Cassava (Manihot esculenta, Crantz) is considered a starchy root crop that provides staple food for millions of people in tropical and subtropical regions of the world. Research efforts are directed toward genetic breeding and cultivation of cassava to improve cassava storage root starch production, nutritional values, and industrial utilization. Cassava storage root (CSR) is a vegetative storage organ with indeterminate type of growth that has a central cylinder (edible part) originated by the swelling of primary root and crown roots. Comprehensive studies on thickened primary root (secondary growth) are rare, incomplete, and to a certain extent, missing. In this chapter, we review and forward studies that move our knowledge on cassava storage root (CSR). CSR generally forms up to 12–14 storage root (SR) per plant, which can originate from three sources of propagating plant materials as well as being induced in vivo and in vitro. Types of storage root (morphologically defined), CSR physiology, tissue anatomy/histology (secondary growth), chemical composition of the edible part, biochemical features, gene expression and proteomics as secondary growth proceeds are of major importance in order to breed cassava plant for agriculture utilization. Storage root morphology varies in shape from cylindrical to globular. Time to initiation of storage root formation varies from 45 to 90 days after planting (DAP), depending on the leaf auxiliary bud position in the vegetative propagating material at the plant source. Storage root growth, starch accumulation, and nutrient contents are largely dependent on genotypes. Storage root anatomy can be identified by eight characteristics common to a root with secondary growth and starch reserve variants. Histological characterizations can be used to identify cell types of primary and secondary meristems, procambium, vascular cambium, phellogen, phelloderm, primary and secondary xylem and phloem, storage parenchyma and sclerenchyma. Three types of meristematic cell differentiations occur as secondary growth proceeds; one due to cork cambium with plane perpendicularly oriented cell division, second due to plane longitudinally oriented cell division in the root apex, and third longitudinally oriented in the epidermal cells. Chemical composition of the storage root varies in the central cylinder (edible part) depending on the sample position in the root and the plant genotype. Therefore, biochemical characteristics are known to change with tissue age as secondary growth proceeds. Moreover, the composition of stored starch varies with tissue age across the central cylinder and may be used as a physiological indicator for bulk storage root maturation and storage root harvest time

Contabilização de operações com derivativos: uma comparação entre o SFAS nº 133 e o arcabouço emanado pelo COSIF

O objetivo deste artigo e realizar uma analise comparativa dos principais aspectos da contabilização das operações com instrumentos financeiros derivativos, comparando o arcabouço emanado pelo Plano Contábil das Instituições do Sistema Financeiro Nacional e o Statement of Financial Accounting Standards - SFAS Nº 133, Accounting for derivative instruments and hedging activities. Após algumas considerações de caráter conceituai, para corroborar o restante da explanação, as principais diferenças entre estes dois pronunciamentos são apresentadas com enfoque especial ao reconhecimento das operações com derivativos como Ativos ou Passivos das entidades envolvidas e as suas respectivas mensurações pelo fair value. As principais conclusões deste artigo apontam para a melhora sensível no conteúdo informativo das demonstrações contábeis, graças ao reconhecimento destes derivativos. A mensuração pelo fair value. apesarde trazer um grau maior de subjetividade ao processo contábil, em muito contribui para alteração significativa da qualidade do mesmo. O trabalho não se ocupa de uma definição rigorosa da operação destes produtos, nem de seus aspectos de precificação e gestão de risco, ficando restrito à abordagem contábil sem definições de caráter tributári

Beyond the shortest path: the path length index as a distribution

The traditional complex network approach considers only the shortest paths from one node to another, not taking into account several other possible paths. This limitation is significant, for example, in urban mobility studies. In this short report, as the first steps, we present an exhaustive approach to address that problem and show we can go beyond the shortest path, but we do not need to go so far: we present an interactive procedure and an early stop possibility. After presenting some fundamental concepts in graph theory, we presented an analytical solution for the problem of counting the number of possible paths between two nodes in complete graphs, and a depth-limited approach to get all possible paths between each pair of nodes in a general graph (an NP-hard problem). We do not collapse the distribution of path lengths between a pair of nodes into a scalar number, we look at the distribution itself - taking all paths up to a pre-defined path length (considering a truncated distribution), and show the impact of that approach on the most straightforward distance-based graph index: the walk/path length

Alguns dados referentes ao estudo parasitológico e anatomopatológico de duas linhagens de Schistosoma mansoni Sambon, 1907

An experiment was carried out in order to determine differences in the pathology of two S. mansoni strains, one from the state of Minas Gerais (Belo Horizonte) and the other from the State of S. Paulo (S. José dos Campos), Brazil. Mice were infected with both strains under experimental conditions and the comparative study of these animals showed significant differences as regards pathology of the tissue lesions. The Belo Horizonte strain showed a higher level of pathogenicity when compared to the S. José dos Campos one.Foi estudada a ação patogênica das linhagens de Schistosoma mansoni dos municípios de Belo Horizonte, MG e de São José dos Campos, SP (Brasil) observando maior capacidade patogênica da linhagem do primeiro, nas condições da experiência

Yield and shelf life of chrysanthemum in response to the silicon application

The potted chrysanthemum is one of the main flowers produced in protected cultivation. Silicon has promoted improvements both in quantitative and qualitative aspects when supplied to some ornamental species produced in these conditions. We evaluated the response of chrysanthemum cultivars grown in pots to the application of silicon. The experiment was conducted in a greenhouse of the Universidade Federal de Viçosa, Minas Gerais state, Brazil. Treatments were arranged in a 3x2 factorial scheme (three cultivars of chrysanthemum: Coral Charm, White Reagan and Indianapolis and two doses of silicon: 0 and 800 mg kg-1) with six replications, in an entirely randomized design. We evaluated the diameter of the flower buds and stems; length of the flower stems; height of the plants; dry matter production of roots, leaves, stems, inflorescence and shoots; total number of inflorescences; diameter of the most fully open inflorescences; Si content in the leaf tissue; and flowering cycle and shelf life. The White Reagan cultivar produced the greatest number of inflorescences (29.17) per pot and proved to be more precocious (85.83 days). There was no negative interaction between Si, Ca and K and no effect of silicon was shown on the production and shelf life of the chrysanthemum. There was an increase in the content of this element in the leaves with the application of potassium metasilicate.O crisântemo de vaso é uma das principais flores produzidas em ambiente protegido. O silício tem promovido melhorias tanto no aspecto quantitativo quanto no qualitativo quando fornecido a algumas espécies ornamentais produzidas nestas condições. Assim, o objetivo desse trabalho foi avaliar a resposta à aplicação de silício de três cultivares de crisântemo cultivadas em vaso. O experimento foi conduzido em casa de vegetação da Universidade Federal de Viçosa. Os tratamentos foram dispostos em esquema fatorial 3x2 (três cultivares de crisântemo: Coral Charm, White Reagan e Indianápolis e duas doses de silício aplicadas no substrato: 0 e 800 mg kg-1) com seis repetições, em delineamento inteiramente casualizado. Foram avaliados o diâmetro dos botões e das hastes florais; comprimento das hastes florais; altura da planta; produção de matéria seca de raízes, folhas, caule, inflorescências e parte aérea; número total de inflorescências; diâmetro da inflorescência mais aberta; teor de Si nos tecidos foliares; ciclo e longevidade floral. A cultivar White Reagan produziu o maior número de inflorescências (29,17) por vaso e mostrou ser mais precoce (85,83 dias). Não houve interação negativa entre Si, Ca e K e não foi constatado efeito do silício na produção e na longevidade das inflorescências de crisântemo. Houve aumento nos teores deste elemento nas folhas com a aplicação do metasilicato de potássio