Heterologous expression in Escherichia coli of Neurospora crassa neutral trehalase as an active enzyme

Neutral trehalase from Neurospora crassa was expressed in Escherichia coli as a polypeptide of similar to 84 kDa in agreement with the theoretical size calculated from the corresponding cDNA. The recombinant neutral trehalase, purified by affinity chromatography exhibited a specific activity of 80-150 mU/mg protein. Optima of pH and temperature were 7.0 and 30 degrees C, respectively. The enzyme was absolutely specific for trehalose, and was quite sensitive to incubation at 40 degrees C. The recombinant enzyme was totally dependent on calcium, and was inhibited by ATP, copper, silver, aluminium and cobalt. K(M) was 42 mM, and V(max) was 30.6 nmol of glucose/min. The recombinant protein was phosphorylated by cAMP-dependent protein kinase, but not significantly activated. Immunoblotting with polyclonal antiserum prepared against the recombinant protein showed that neutral trehalase protein levels increased during exponential phase of N. crassa growth and dropped at the stationary phase. This is the first report of a neutral trehalase produced in E. coli with similar biochemical properties described for fungi native neutral trehalases, including calcium-dependence. (C) 2008 Elsevier Inc. All rights reserved.

Influence of package, type of apple juice and temperature on the production of patulin by Byssochlamys nivea and Byssochlamys fulva

Although the production of patulin in apple fruits is mainly by Penicillium expansum, there is no information on the ability of heat resistant moulds that may survive pasteurization to produce this mycotoxin in juice packages during storage and distribution. In this study, the production of patulin by Byssochlamys spp (Byssochlamys nivea FRR 4421, B. nivea ATCC 24008 and Byssochlamys fulva IOC 4518) in cloudy and clarified apple juices packaged in laminated paperboard packages or in polyethylene terephthalate bottles (PET) and stored at both 21 degrees C and 30 degrees C, was investigated. The three Byssochlamys strains were able to produce patulin in both cloudy and clarified apple juices. Overall, the lower the storage temperature, the lower the patulin levels and mycelium dry weight in the apple juices (p<0.05). The greatest variations in pH and degrees Brix were observed in the juices from which the greatest mycelium dry weights were recovered. The maximum levels of patulin recovered from the juices were ca. 150 mu g/kg at 21 degrees C and 220 mu g/kg at 30 degrees C. HPLC-UV, HPCL-DAD and mass spectrometry analyses confirmed the ability of B. fulva IOC 4518 to produce patulin. Due to the heat resistance of B. nivea and B. fulva and their ability to produce patulin either in PET bottles or in laminated paperboard packages, the control of contamination and the incidence of these fungi should be a matter of concern for food safety. Control measures taken by juice industries must also focus on controlling the ascospores of heat resistant moulds. (C) 2010 Elsevier B.V. All rights reserved.

Adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface: A spectroscopic study

The adsorption of the diazo dye Direct Red 23 onto a zinc oxide surface at 30 degrees C in the dark was investigated. The color reduction was monitored by spectrophotometry at 503 run. The FTIR and Raman spectra of the Direct Red 23 adsorption as a function of ZnO concentration were registered. From the PM3 semi-empirical calculations of the atomic charge density and dipole moment of the Direct Red 23 molecule, it was demonstrated that the azo, dye molecule may be adsorbed onto the ZnO Surface through molecule geometry modifications, enhancing the interfacial area causing a variation in the bonding frequencies. (C) 2009 Elsevier B.V. All rights reserved.

Amylopectin-rich starch plasticized with glycerol for polymer electrolyte application

This paper describes the preparation and characterization of a solid polymer electrolyte based on amylopectin-rich starch plasticized with glycerol. The samples were characterized through ionic conductivity (sigma) measurements, scanning electron microscopy, thermal analysis, and spectroscopy in the UV-Vis-NIR region. The results showed that the highest sigma (1.1 x 10(-4) Scm(-1) at 30 degrees C) was obtained for the sample with n = [O]/[Li] = 6.5 ratio. In addition, the samples plasticized with 30-35 wt.% of glycerol presented high ionic conductivity, transparency and conduction stability. The ionic conductivity measurements as a function of lithium salt contents showed a maximum for n=6.5. The ionic conductivity as a function of time for amylopectin-rich starch plasticized with 30 wt.% of glycerol and containing [O]/[Li] = 10 showed conduction stability over 6 months (sigma similar to 3.01 x 10(-5) S cm(-1)). (C) 2010 Elsevier B.V. All rights reserved.

Identifiering av parametrar till ackumulatortanken Solus1050 från consolar - en metodbeskrivning

This report describes the work done creating a computer model of a kombi tank from Consolar. The model was created with Presim/Trnsys and Fittrn and DF were used to identify the parameters. Measurements were carried out and were used to identify the values of the parameters in the model. The identifications were first done for every circuit separately. After that, all parameters are normally identified together using all the measurements. Finally the model should be compared with other measurements, preferable realistic ones. The two last steps have not yet been carried out, because of problems finding a good model for the domestic hot water circuit.The model of the domestic hot water circuit give relatively good results for low flows at 5 l/min, but is not good for higher flows. In the report suggestions for improving the model are given. However, there was not enough time to test this within the project as much time was spent trying to solve problems with the model crashing. Suggestions for improving the model for the domestic circuit are given in chapter 4.4. The improved equations that are to be used in the improved model are given by equation 4.18, 4.19 and 4.22.Also for the boiler circuit and the solar circuit there are improvements that can be done. The model presented here has a few shortcomings, but with some extra work, an improved model can be created. In the attachment (Bilaga 1) is a description of the used model and all the identified parameters.A qualitative assessment of the store was also performed based on the measurements and the modelling carried out. The following summary of this can be given: Hot Water PreparationThe principle for controlling the flow on the primary side seems to work well in order to achieve good stratification. Temperatures in the bottom of the store after a short use of hot water, at a coldwater temperature of 12°C, was around 28-30°C. This was almost independent of the temperature in the store and the DHW-flow.The measured UA-values of the heat exchangers are not very reliable, but indicates that the heat transfer rates are much better than for the Conus 500, and in the same range as for other stores tested at SERC.The function of the mixing valve is not perfect (see diagram 4.3, where Tout1 is the outlet hot water temperature, and Tdhwo and Tdhw1 is the inlet temperature to the hot and cold side of the valve respectively). The outlet temperature varies a lot with different temperatures in the storage and is going down from 61°C to 47°C before the cold port is fully closed. This gives a problem to find a suitable temperature setting and gives also a risk that the auxiliary heating is increased instead of the set temperature of the valve, when the hot water temperature is to low.Collector circuitThe UA-value of the collector heat exchanger is much higher than the value for Conus 500, and in the same range as the heat exchangers in other stores tested at SERC.Boiler circuitThe valve in the boiler circuit is used to supply water from the boiler at two different heights, depending on the temperature of the water. At temperatures from the boiler above 58.2°C, all the water is injected to the upper inlet. At temperatures below 53.9°C all the water is injected to the lower inlet. At 56°C the water flow is equally divided between the two inlets. Detailed studies of the behaviour at the upper inlet shows that better accuracy of the model would have been achieved using three double ports in the model instead of two. The shape of the upper inlet makes turbulence, that could be modelled using two different inlets. Heat lossesThe heat losses per m3 are much smaller for the Solus 1050, than for the Conus 500 Storage. However, they are higher than those for some good stores tested at SERC. The pipes that are penetrating the insulation give air leakage and cold bridges, which could be a major part of the losses from the storage. The identified losses from the bottom of the storage are exceptionally high, but have less importance for the heat losses, due to the lower temperatures in the bottom. High losses from the bottom can be caused by air leakage through the insulation at the pipe connections of the storage.

Handbok för kombinerade sol- och biovärmesystem : Teknik - System - Ekonomi

Handboken beskriver olika solfångarkonstruktioner och solvärmekretsens ingående komponenter och ger en grundlig inblick i ackumulatortankens konstruktion och funktion. I boken finns förslag på systemutformning, olika tekniska lösningar och hur systemen bör styras och regleras. Handboken beskriver i första hand utformning-lösning-styrning av kombinationen sol- och pelletsvärme, men tar även upp solvärme i kombination med vedpannor, värmedrivna vitvaror och värmepumpar. Värmesystem med vattenburen värme är utmärkta att kombinera med solvärme, men det är i de flesta fall enklare att få till bra lösningar vid nyinstallation, än vid komplettering av befintlig anläggning. När solvärme och pelletsvärme ska kombineras finns det många alternativ till systemutformning. Det är viktigt att vattenburna pelletssystem utformas korrekt och kombineras på rätt sätt med solvärme för att komforten ska bli hög och elanvändningen låg. Vattenmantlade pelletskaminer med ett vattenburet värmesystem är extra intressant i kombination med solvärme. När eldningen upphör i samband med att värmebehovet avtar kan solvärmen ta över. En generell slutsats är att konventionella svenska pelletspannor med inbyggd varmvattenberedning inte är lämpliga i kombination med solvärmesystem. Den typen av bränslepannor ger komplicerade systemlösningar, höga värmeförluster och det är svårt att åstadkomma en tillräckligt bra temperaturskiktning i ackumulatortanken om varmvattenberedning sker i pannan. Solvärme för varmvattenberedning kan vara ett enkelt och bra komplement till pelletskaminer som genererar varmluft. För solvärmesystem är det viktigt att kraftig temperaturskiktning erhålls när värmelagret laddas ur. Det betyder att ackumulatortankens (eller varmvattenberedarens) nedre vattenvolym ska kylas ner till temperaturer som ligger nära ingående kallvattentemperatur. Ackumulatortankens mellersta del bör kylas till samma temperatur som radiatorreturen. Vid design av solfångarkretsen måste överhettning och stagnation kunna klaras utan risk för glykolnedbrytning eller andra skador på värmebärare eller rörkrets (och andra komponenter i kretsen). Partiell förångning minskar risken för att glykolen skadas då solfångaren når höga stagnationstemperaturer. Solfångarens glykolblandning tillåts koka (förångas) på ett kontrollerat sätt så att endast ånga blir kvar i solfångaren. Vätskevolymen i solfångaren samlas upp i ett större expansionskärl och systemet återfylls när vätskan kondenserar. Dränerande solfångarsystem med enbart vatten är ett möjligt alternativ till konventionella solfångare. De kräver en större noggrannhet vid installationen, så att sönderfrysning undviks. Dränerande systemlösningar är relativt ovanliga i Sverige. Om solfångaren under senhöst-vinter-tidig vår kan arbeta med att förvärma kallvatten från 10 till 20 ºC erhålls en betydligt bättre verkningsgrad på solfångaren (och framför allt ökar värmeutbytet då drifttimmarna ökar väsentligt) än om radiatorreturen (som i bästa fall ligger på temperaturnivån 30 - 40 ºC) ska förvärmas. Därför bör radiatorreturen placeras en bra bit upp från botten i ackumulatortanken och tappvarmvattnet ska förvärmas i en slinga som börjar i tankens botten. Om det finns ett VVC-system måste systemet anslutas på ett speciellt sätt så att ackumulatortankens temperaturskiktning inte störs. En viktig parameter vid ackumulatortankens utformning är att värmeförlusterna hålls låga. Det är viktigt för att klara tappvarmvattenlasten med solvärme under mulna perioder sommartid (men också för att hålla energianvändningen låg). I moderna hus, där ackumulatortanken i regel placeras i bostaden, blir det en komfortfråga att undvika övertemperaturer i det rum där värmelagret placeras. En bra standard på isoleringen (med minimerade värmeförluster) kräver att det finns ett lufttätt skikt över hela isoleringen som dessutom sluter tätt mot röranslutningar. Ofrivillig självcirkulation i anslutande kretsar som kan kyla av och blanda om ackumulatortankens vattenvolym, bör förhindras med backventiler och nedböjning av rören i isolerskiktet eller direkt utanför tanken.

Mexico 1982 e 1994: duas crises de balanço de pagamentos

O estudo trata dos fatores que influenciaram na geração das crises mexicanas de balanço de pagamentos de 1982 e 1994 e os processos de retomada do crescimento econômico do país. A questão é analisada sob o prisma da importância relativa dos fatores político-institucionais na geração e recuperação dessas crises.

Conflitos politicos e ideologicos nas Forças Armadas brasileiras : (1945 a 1964)

o estudo que ora apresentamos nesta dissertação tem corno objetivo principal compreender a interferência dos militares brasileiros, pela ação dos seus quadros, na política nacional durante o período estudado. Embora certos que nao esgotamos este assunto, ternos convicção, entretanto, que o método por nós perseguido pode, no entanto, esclarecer alguns elos de relação entre a prática e a ideologia, a ideologia e a pratica, desses agentes fundamentais na história nacional. Em virtude da existência de livros que documentam, embora com outros métodos de análise, a prática política dos quadros militares, bem corno explicitam as suas ideologias,utilizamos o método de pesquisa bibliográfica e documental. Não nos foi necessário o uso de entrevistas, pois vários dos principais quadros caracterizadores de posturas políticas e ideológicas deixaram livros ou documentos escritos. Corno os militares estão inseridos na sociedade, na economia e na política geral, tivemos de analisar algumas teorias e práticas globais no âmbito de disciplinas que, de certa forma, refletem as posturas ideológicas globais no âmbito das quais os quadros militares se identificaram. o resultado de nosso estudo levou-nos a conclusão de que não havia coerência política e ideológica no núcleo definidor das táticas políticas de ação do núcleo contestador às forças defensoras do imperialismo norte-americano no pos segunda guerra mundial, pois há muito tempo a burguesia nacio IV na1 havia sido diluída no jogo de interesse onde os capitais internacionais, os grandes monopólios a absorveram e o Brasil internacionalizou sua economia, tornando-se dependente nao só como país mas também por sua burguesia que passara a ,ser só cia menor, no entanto bem aquinhoada, do capital externo. Ficou claro, então, que a forma atual e viável de enfrentamento com o imperialismo, principalmente o norte americano, é a preparação, pelos quadros revolucionários, da revolução socialista. o golpe civil e militar de 1964 instituiu um poder militar mantenedor da nova ordem no Brasil: o Capitalismo Monopo1ista de Estado.

O Supremo Tribunal Federal e a instabilidade politico institucional

Nosso propósito neste trabalho é focalizar o comportamento do Supremo Tribunal Federal dentro de urna época ainda não estudada pela escassa literatura sobre a mais Alta Corte de Justiça brasileira a fase histórica 1964/1975. Fixa-se ele mais dentro do campo da Ciência política e referir-se-a a fatos, relações, tipos de pressões, de apoio , de solicitação que originem as deliberações, crises e reações do Supremo Tribunal Federal enfim, a mecânica extrínseca e intrínseca de seu funcionamento, ao sabor do amaranhado de um sistema político, do qual faz parte, influenciando-o e sendo por ele influenciado.

Espirito Santo : Estado, interesses e poder

Esta monografia pretende contribuir com o estudo das relações que se estabelecem entre o Estado e a sociedade. Dentro desse espectro buscou-se centrar o foco das análises na dimensão das inter-relações que se estabelecem entre Poder Regional e Poder Central no contexto da Formação Social Brasileira. Para tanto delimitou-se o escopo das análises ao estudo de um caso, considerando as diversas unidades federadas que compõe o Estado brasileiro. Dentre essas unidades a escolha recaiu no Estado do Espírito Santo, considerado periférico no conjunto do desenvolvimento capitalista nacional. A análise procurou recuperar a trajetória histórica do desenvolvimento da região do Espírito Santo desde a colonização portuguesa até, praticamente, aos dias atuais, isto é a década de 60 do presente século. A ênfase principal, no entanto, foi centrada no desenvolvimento sócio-econômico e político contemporâneo, ou seja a partir da Proclamação da República até o Movimento Político-Militar de março de 1964. Em termos de conteúdo específico procura-se desvendar como que os interesses das classes sociais localizadas no Estado do Espírito Santo foram constituídos, nessa fase de desenvolvimento recente, e articulados a nível do Estado: na instãncia Regional, em primeiro lugar, e na instância Central, em segundo lugar. A dinâmica das inter-relações que aí se estabelecem, bem como. a forma como o Espírito Santo foi inserido no contexto do desenvolvimento capitalista nacional, ao longo dos anos, é uma preocupação constante em todo o trabalho. Também, a ação do Estado, principalmente da instância Regional, sob a direção dos vários governantes que estiveram a frente do Aparelho Regional de Estado constituiu-se em um dos eixos básicos das análises realizadas. Por outro lado, na medida que as relações entre o Estado e a sociedade passa, na vigência de regimes democráticos, pelas instituições partidárias, grande ênfase foi dada ao processo de constituição de Partidos Políticos no Espírito Santo, tanto no período da Primeira República como no período da Segunda República, isto é de 1945 a 1964. Em suma, espera-se que os resultados alcançados possam contribuir com a ampliação do conhecimento sobre as questões do Estado por um lado, e, possam trazer luzes que contribuam com o conhecimento específico sobre o Estado do Espírito Santo, por outro. Mas, mais que isso, espera-se que as análises realizadas possam trazer pistas que estimulem outros pesquisadores a desvendar veredas que não puderam ser trilhadas no curso da elaboração dessa monografia.