Ensaio de atividade de B-galactosidase em Gluconacetobacter diazotrophicus para estudos de expressão gênica.

Este Comunicado Técnico mostra a repetitibilidade de ensaios de atividade de ?-galactosidase, que foram padronizados com G. diazotrophicus, ilustrando sua utilidade em estudos de expressão gênica que envolvem fusões com o gene repórter lacZ. Os resultados mostrados neste Comunicado Técnico ilustram que o meio, as condições de cultivo e o ensaio de atividade de ?-galactosidase estabelecidos para G. diazotrophicus são reprodutíveis, e, portanto, válidos, sendo de grande valia para quantificar níveis de expressão gênica nessa importante bactéria constituinte do inoculante para cana-de-açúcar da Embrapa.bitstream/item/42760/1/COT123-09.pd

Anaerobic decolorization of an azo dye by a mixed culture

Wool dyeing wastewater contains xenobiotic compounds that can be removed by biotechnological processes. Studies on various dyes showed that anaerobic processes are suitable to alter azo dyes as a first step of the biodegradation process. These compounds are reduced by anaerobic consortia to aromatic amines and its ultimate degradation can be achieved by a further aerobic treatment. Studies on degradation rate of an wool acid dye were performed in batch systems inoculated with anaerobic biomass. A commercial diazo dye, Acid Red 73, was added to the synthetic medium in which glucose was used as sole carbon source. Results indicated that the Acid Red 73 was partially degraded by a mixed culture of anaerobic bacteria and a decolorization of 90% was obtained. Kinetics studies on removal of the colour showed that the decolorization rate was several times faster than the degradation rate of glucose for a range of dye concentrations between 60 mg/L and 400 mg/L. A first order kinetic model was used for dye concentrations up to 200 mg/L. For higher concentrations a model similar to the Michaelis-Menten equation was better fitted to the experimental data.(undefined

Characterisation of ultra- and nanofiltration membranes for predictive purposes - development of a model for hindered transport of uncharged solutes in asymmetric pores

Fundação para a Ciência e a Tecnologia (FCT

Degradation of mixtures of phenols using boron doped diamend electrodes for wastewater treatment

A model is proposed for describing the electrochemical oxidation of multicomponent mixtures of organic compounds, when significant mineralization (i.e., combustion to CO2) of the compounds occurs. This is known to be the case of the degradation of many organic compounds on boron doped diamond (BDD) and other new lectrocatalytic materials used as anodes. The proposed model predicts the variation of concentrations of each component present in the mixture, chemical oxygen demand (COD) and current efficiency as a function of time, under different rate control regimes (diffusive, kinetic and mixed) at constant current. Mass transfer coefficients of each component of the mixture, needed for the application of the model, were obtained from single solute experiments. Tests were conducted in a conventional three-electrode cell, using a commercial BDD electrode as anode. Good agreement between predicted and experimental results was generally obtained, though some deviations had been observed when the highest concentrations of the solutes were used, with concentrations decreasing faster than predicted. These deviations were found for both single- and multi-component systems, and can be explained by the occurrence of side reactions or the accumulation of intermediate compounds of the combustion mechanism

Improving performance by improving the relationship with the companies in the supply chain

This paper will address issues related to strategy, quality and management of customers and suppliers, and its main objective is to demonstrate the benefits of cooperation between customers and suppliers in the supply chain. A case is presented about a Brazilian company with assets in several sectors of the economy that implemented a program to reward the cooperation of its key suppliers and obtained several benefits with this program. Finally, it is concluded that issues such as identification of the real needs and expectations of stakeholders, the philosophy of quality at source, consolidation of the customer base and suppliers and cooperation between companies are key points for improving business performance, at every link in the supply chain

The costs and benefits of leaving the EU: Trade effects

This paper estimates the welfare effects of Brexit, focusing on trade and fiscal transfers. We use a standard quantitative general equilibrium trade model with many countries and sectors and trade in intermediates, as in Costinot and Rodríguez-Clare (2014). We simulate a range of counterfactuals reflecting alternative options for EU-UK relations following Brexit. Welfare losses for the average UK household are 1.3% if the UK remains in the EU's Single Market like Norway (a “soft Brexit”).Losses rise to 2.7% if the UK trades with the EU under World Trade Organization rules (a “hard Brexit”). A reduced form approach that captures the dynamic effects of Brexit on productivity more than riples these losses and implies a decline in average income per capita of between 6.3% and 9.4%, partly via falls in foreign investment. These negative effects are widely shared across the entire income distribution and are unlikely to be offset from new trade deals

Aqueous humor erythropoietin levels in open-angle glaucoma patients with and without TTR V30M familial amyloid polyneuropathy

Purpose: Glaucoma is the leading cause of irreversible blindness in familial amyloidotic polyneuropathy (FAP) patients. Erythropoietin (EPO) is a cytokine that has been shown to play a role in neuroprotection and is endogenously produced in the eye. EPO levels in the aqueous humor are increased in eyes with glaucoma. In this study, we evaluated the EPO concentration in the aqueous humor of FAP and non-FAP patients, with and without glaucoma. Methods: Undiluted aqueous humor samples were obtained from 42 eyes that underwent glaucoma surgery, phacoemulsification, or vitrectomy. EPO concentration in the aqueous humor and blood were measured using the Immulite 2000 Xpi using an automatic analyzer (Siemens Healthcare Diagnostics). Results: The mean EPO concentration in the aqueous humor of non-FAP glaucoma eyes group 2 (75.73±13.25 mU/ml) was significantly higher than non-FAP cataract eyes (17.22±5.33 mU/ml; p<0.001), FAP glaucoma eyes (18.82±10.16 mU/ml; p<0.001), and FAP nonglaucoma eyes (20.62±6.22 mU/ml; p<0.001). There was no statistically significant difference between FAP nonglaucoma eyes versus non-FAP cataract eyes (p = 0.23) and FAP glaucoma eyes versus FAP nonglaucoma eyes (p = 0.29). In the glaucoma groups, there was no correlation between the aqueous humor EPO concentration and the ocular pressure (p = 0.95) and mean deviation (p = 0.41). There was no correlation between the EPO serum concentration and EPO aqueous humor concentration in our patients (p = 0.77). Conclusions: Unlike other glaucomatous patients, FAP patients with glaucoma do not show increased and potentially neuroprotective endocular EPO production in the aqueous humor and may need more aggressive glaucoma management

Plasmid DNA recovery from fermentation broths by a combined process of micro- and ultrafiltration : modeling and application

Microfiltration and ultrafiltration operations were used in tandem to isolate and purify a 6050 bp plasmid DNA (pDNA). To achieve primary isolation of the plasmid from fermentation broths, immediately after cell lysis, a 0.2 μm microfiltration membrane was selected for solid/liquid separation, which was performed in a diafiltration mode, as an alternative to centrifugation. Then to attain plasmid concentration and purification, an ultrafiltration membrane with a pore radius of 4.1 nm was selected. Permeation of pDNA and RNA in the two membrane steps was modeled using recently published mass transfer models applicable to the permeation of closed segmented chains and freely-jointed chains, respectively. The permeation of proteins and genomic DNA (gDNA) was also studied in these operations. The microfiltration operation allowed high plasmid and RNA permeation, as expected. It was observed that significant amounts of gDNA, previously precipitated during the cell lysis step, reappear in solution during the diafiltration step. The effect of the ionic strength on this apparent re-solubilization was investigated, by testing the addition of two different salts to the diafiltration buffer: CH3COOK and CaCl2. The results show that these salts can be used to control gDNA apparent re-solubilization. During the ultrafiltration operation high plasmid retention with low adsorption was obtained under low ionic strength conditions. The results also show that a significant removal proteins and the re-solubilized gDNA is achieved, as well as some purification in respect to low molecular weight RNA, since all these components permeate through the ultrafiltration membrane

Thermal Diffusion of a Two Layer System

In this paper thermal conductivity and thermal diffusivity of a two layer system is examined from the theoretical point of view. We use the one dimensional heat diffusion equation with the appropriate solution in each layer and boundary conditions at the interfaces to calculate the heat transport in this bounded system. We also consider the heat flux at the surface of the samle as boundary condition instead of using a fixed tempertaure. From this, we obtain an expression for the efective thermal diffusivity of the composite sample in terms of the thermal diffusivity of its constituent materials whithout any approximations.Comment: 16 pages, 1 figure, RevTeX v. 3.0 macro packag