Endophytic potential of entomopathogenic fungi associated with Urochloa ruziziensis (Poaceae) for spittlebug (Hemiptera: Cercopidae) control.

Spittlebugs are pests that affect forage plants in tropical America, causing damage to such plants and causing significant annual losses in milk and meat production. One of the alternatives for combating these insect pests with minimal environmental impacts is the use of entomopathogenic fungi. The objectives of this research were: (i) to evaluate the endophytic potential of entomopathogenic fungi applied to Urochloa ruziziensis (R.Germ. & C.M.Evrard) Crins (synonymous with Brachiaria ruziziensis; Poaceae) through seed treatment for the control of the spittlebug species, Mahanarva spectabilis (Distant) and Deois schach (F.) (Hemiptera: Cercopidae); (ii) to analyze the efficiency of banker plants as a means of spreading the fungi to the field; and (iii) to determine the frequency of infection after the storage of treated seeds. U. ruziziensis seeds were treated with a suspension containing 1 × 108 conidia of the fungi Fusarium sp. (Hypocreales: Nectriaceae), Metarhizium anisopliae (Metschn.) Sorokīn (Hypocreales: Clavicipitaceae) or a commercial strain of M. anisopliae for 30 min, after which they were planted in 2 L planters and kept in a greenhouse. The surplus of treated seeds was conditioned at 22 °C and sown monthly for 10 months. Insects were fed plants from treated seeds. The entomopathogenic fungi were found to be endophytic and to equally infect the two species of spittlebugs from pastures, M. spectabilis and D. schach, at different stages of development; however, they caused low nymphal mortality. The banker plant technique with plants from seeds treated with entomopathogenic fungi was efficient. Furthermore, it was observed that it is possible to store seeds treated with fungi for 12 months. These results open the perspective of using entomopathogenic fungi with endophytic action as an auxiliary tool in reducing the populations of pasture spittlebugs in tropical regions

Sistemas de integração lavoura-pecuária-floresta como alternativa para produção pecuária leiteira sustentável em áreas declivosas.

Integração Lavoura-Pecuária-Floresta (iLPF); Vantagens do uso da integração Lavoura-Pecuária-Floresta; Alternativas de Integração Lavoura-Pecuária-Floresta; Adubação de plantio e de cobertura/manutenção do sistema iLPF; Arranjos de semeadura e manejo de herbicidas sobre espécies forrageiras e culturas; O componente florestal nos sistemas integrados de produção; Arranjos e densidade populacional das essências florestais; Silagem de braquiária como alternativa de suplementação volumosa na época da seca; Aspectos econômicos em sistemas de integração-lavoura-pecuária-floresta; Transferência de tecnologia em sistemas integrados de produção

Genomics and epidemiology for gastric adenocarcinomas (GE4GAC): a Brazilian initiative to study gastric cancer

Abstract Gastric cancer (GC) is the fifth most common type of cancer worldwide with high incidences in Asia, Central, and South American countries. This patchy distribution means that GC studies are neglected by large research centers from developed countries. The need for further understanding of this complex disease, including the local importance of epidemiological factors and the rich ancestral admixture found in Brazil, stimulated the implementation of the GE4GAC project. GE4GAC aims to embrace epidemiological, clinical, molecular and microbiological data from Brazilian controls and patients with malignant and pre-malignant gastric disease. In this letter, we summarize the main goals of the project, including subject and sample accrual and current findings

Determination of inhibition in the enzymatic hydrolysis of cellobiose using hybrid neural modeling

Neural networks and hybrid models were used to study substrate and product inhibition observed in the enzymatic hydrolysis of cellobiose at 40ºC, 50ºC and 55ºC, pH 4.8, using cellobiose solutions with or without the addition of exogenous glucose. Firstly, the initial velocity method and nonlinear fitting with Statistica<FONT FACE=Symbol>Ò</FONT> were used to determine the kinetic parameters for either the uncompetitive or the competitive substrate inhibition model at a negligible product concentration and cellobiose from 0.4 to 2.0 g/L. Secondly, for six different models of substrate and product inhibitions and data for low to high cellobiose conversions in a batch reactor, neural networks were used for fitting the product inhibition parameter to the mass balance equations derived for each model. The two models found to be best were: 1) noncompetitive inhibition by substrate and competitive by product and 2) uncompetitive inhibition by substrate and competitive by product; however, these models’ correlation coefficients were quite close. To distinguish between them, hybrid models consisting of neural networks and first principle equations were used to select the best inhibition model based on the smallest norm observed, and the model with noncompetitive inhibition by substrate and competitive inhibition by product was shown to be the best predictor of cellobiose hydrolysis reactor behavior