Purification, characterization and molecular cloning of the major chitinase from Tenebrio molitor larval midgut

Insect chitinases are involved in degradation of chitin from the exoskeleton cuticle or from midgut peritrophic membrane during molts. cDNAs coding for insect cuticular and gut chitinases were cloned, but only chitinases from moulting fluid were purified and characterized. In this study the major digestive chitinase from T. molitor midgut (TmChi) was purified to homogeneity, characterized and sequenced after cDNA cloning. TmChi is secreted by midgut epithelial cells, has a molecular weight of 44 kDa and is unstable in the presence of midgut proteinases. TmChi shows strong substrate inhibition when acting on umbelliferyl-derivatives of chitobio- and chitotriosaccharides, but has normal Michaelis kinetics with the N-acetylglucosamine derivative as substrate. TmChi has very low activity against colloidal chitin, but effectively converts oligosaccharides to shorter fragments. The best substrate for TmChi is chitopentaose, with highest kcat/KM value. Sequence analysis and chemical modification experiments showed that the TmChi active site contains carboxylic groups and a tryptophane, which are known to be important for catalysis in family 18 chitinases. Modification with p-hidroximercuribenzoate of a cysteine residue, which is exposed after substrate binding, leads to complete inactivation of the enzyme. TmChi mRNA encodes a signal peptide plus a protein with 37 kDa and high similarity with other insect chitinases from family 18. Surprisingly, this gene does not encode the C-terminal Ser-Thr-rich connector and chitin-binding domain normally present in chitinases. The special features of TmChi probably result from its adaptation to digest chitin-rich food without damaging the peritrophic membrane. © 2006 Elsevier Ltd. All rights reserved

Influence of the body mass and visceral adiposity on glucose metabolism in obese women with Pro12Pro genotype in PPARgamma2 gene.

Introduction: Glucose metabolism may be altered in obesity and genotype for PPAR 2 can influence this variable. Objective: To evaluate the influence of body mass (BM) and visceral adiposity (VA) in glucose metabolism in morbid obese women with Pro12Pro genotype. Methods: Were selected 25 morbidly obese women. Groups were formed according to body mass index (BMI) [G1: 40-45 kg/m2 (n = 17); G2: > 45 kg/m2 (n = 8)]. Anthropometric, glycemia and insulinemia assessments (fasting, 60 and 120 minutes after high polyunsaturated fatty acids meal) were carried out. The insulin resistance (IR) and insulin sensitivity (IS) were assessed by HOMA-IR and QUICKI respectively. Results: G2 had higher BMI and waist circumference, compared to G1, impaired fasting glucose, low IS and higher IR. The postprandial glucose was normal, but there was a higher insulin peak one hour after the meal in G2. Conclusion: Increased BM and VA were associated with worse glucose metabolism suggesting metabolic differences between morbid obese with Pro12Pro genotype

Genetic characterization of Indubrasil cattle breed population.

Abstract The Indubrasil breed was developed in the Brazilian region called Triângulo Mineiro as a result of a cross between zebu cattle. Initially, it was used as a terminal cross and currently it represents approximately 4.45% of all the Brazilian zebu cattle. Studies were conducted to estimate genetic parameters in the Indubrasil using pedigree information, however, until now, no study has been developed using large-scale genomic markers in this breed. Pedigree information are widely used to investigate population parameters; however, they can neglect some estimates when compared to the use of genomic markers. Therefore, the objective of this study was to investigate the population structure and the genetic diversity of Indubrasil cattle using a high-density Single Nucleotide Polymorphism (SNP) panel (Illumina BovineHD BeadChip 700k). Levels of genomic homozygosity were evaluated using three different approaches: Runs of homozygosity (FROH), % of homozygosis (FSNP), and inbreeding coefficient (Fx). Further, Runs of Homozygosity (ROH) segments conserved among the animals were investigated to identify possible regions associated with the breed characteristics. Our results indicate that even the Indubrasil breed having a small effective population size, the levels of homozygosity (FROH = 0.046) are still small. This was possibly caused by the cross conducted among different breeds for its development. It suggests no immediate risks associated with loss of genetic variation. This information might be used in breeding programs, for the breed conservation and for the expansion of the Indubrasil breed

Potencial de Bacillus spp. em promover o crescimento e controlar Fusarium verticillioides em milho.

Resumo: O tratamento de sementes com microrganismos visando promoção de crescimento e controle de Fusarium verticillioides é uma tecnologia que poderá ser utilizada para ampliar a sustentabilidade da cultura do milho. Para tanto, estudos com a utilização de microrganismos para tratamento de sementes visando ao controle de F. verticillioides e promoção de crescimento vegetal em milho são necessários para o desenvolvimento de bioprodutos. Onze isolados de Bacillus spp. foram testados quanto às características bioquímicas relacionadas com promoção de crescimento (produção de ácido cianídrico, ácido indolacético, sideroforos e catalase; solubilização de fosfato e assimilação de nitrogênio). Ainda in vitro foi avaliada a habilidade dos isolados de Bacillus em inibir o crescimento micelial e a germinação de conídios de F. verticillioides. Em casa de vegetação foi avaliado o efeito dos isolados de Bacillus spp. na promoção de crescimento e no controle de F. verticillioides em duas variedades de milho. Bacillus velezensis AP03 e Bacillus sp. AP-210, não somente inibiram o crescimento micelial e a germinação de esporos, mas também promoveram o crescimento das plantas e controlaram F. verticillioides em sementes de milho em condições de casa de vegetação. -- Abastract: Seed treatment with microorganisms aiming to promote plant growth and Fusarium verticillioides control is a technology that can be used to improve the sustainability of corn crops. Therefore, studying the use of microorganisms for seed treatment with the aim of controlling F. verticillioides and promoting plant growth in corn is necessary for the development of bioproducts. Eleven isolates of Bacillus spp. were tested for their biochemical characteristics related to growth promotion (production of hydrocyanic acid, indoleacetic acid, siderophores and catalase; phosphate solubilization, and nitrogen assimilation). Also in vitro, the ability of Bacillus isolates to inhibit F. verticillioides mycelial growth and conidial germination was assessed. In a greenhouse, the effect of the isolates of Bacillus spp. was evaluated on growth promotion and F. verticillioides control in two varieties of corn. Bacillus velezensis AP-03 and Bacillus sp. AP-210 not only inhibited mycelial growth and spore germination, but also promoted plant growth and controlled F. verticillioides in corn seeds under greenhouse conditions

Tecido urbano e mercado imobiliário em São Paulo: metodologia de estudo com base na Décima Urbana de 1809

Este artigo apresenta uma metodologia inédita de espacialização da Décima Urbana, primeiro imposto predial estabelecido para as cidades brasileiras. Focaliza o caso de São Paulo, em 1809. Os dados recolhidos na documentação textual foram processados em banco de dados e cartografados na primeira planta cadastral da cidade, elaborada pelo engenheiro Carlos Bresser, entre 1844-1847, e confrontados com a documentação iconográfica dos viajantes e de Militão Augusto de Azevedo, de modo a precisar as informações obtidas. A Décima Urbana de 1809 contém informações sobre a localização dos imóveis, seus proprietários, inquilinos, tipologias (casas térreas, sobrados, lojas), finalidades (uso próprio, aluguel), usos (residencial, comercial, misto) e valor, que hoje nos permitem reconstituir hipoteticamente o velho tecido urbano da cidade de São Paulo e aspectos da dinâmica do seu mercado imobiliário em fins do período colonial.This article presents a new spatialisation methodology for the Décima Urbana, the first property tax established in Brazilian cities. The case of São Paulo in 1809 is studied. The data gathered from textual documentation was processed in a database and cartographed on the first official city plan, elaborated by engineer Carlos Bresser between 1844-1847, and then confronted with the iconographic documentation produced by visiting travellers and by photographer Militão Augusto de Azevedo, so as to cross-reference the information obtained. The Décima Urbana of 1809 contains data about the siting of buildings, their proprietors, tenants, typology (single and two-storey houses, shops), finalities (own use, rent), uses (residential, commercial, mixed) and value. This allows for the present day hypothetical reconstruction of old São Paulo's urban mesh and of aspects of the real estate market dynamics at the end of the colonial period

Operations of and Future Plans for the Pierre Auger Observatory

Technical reports on operations and features of the Pierre Auger Observatory, including ongoing and planned enhancements and the status of the future northern hemisphere portion of the Observatory. Contributions to the 31st International Cosmic Ray Conference, Lodz, Poland, July 2009.Comment: Contributions to the 31st ICRC, Lodz, Poland, July 200

Anisotropy and chemical composition of ultra-high energy cosmic rays using arrival directions measured by the Pierre Auger Observatory

The Pierre Auger Collaboration has reported evidence for anisotropy in the distribution of arrival directions of the cosmic rays with energies $E>E_{th}=5.5\times 10^{19}$ eV. These show a correlation with the distribution of nearby extragalactic objects, including an apparent excess around the direction of Centaurus A. If the particles responsible for these excesses at $E>E_{th}$ are heavy nuclei with charge $Z$, the proton component of the sources should lead to excesses in the same regions at energies $E/Z$. We here report the lack of anisotropies in these directions at energies above $E_{th}/Z$ (for illustrative values of $Z=6,\ 13,\ 26$). If the anisotropies above $E_{th}$ are due to nuclei with charge $Z$, and under reasonable assumptions about the acceleration process, these observations imply stringent constraints on the allowed proton fraction at the lower energies

Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius $A$. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio