alpha-Hydroxynitrile lyase protein from Xylella fastidiosa: Cloning, expression, and characterization

Xylella fastidiosa is a xylem-restricted plant pathogen that causes a range of diseases in several and important crops. Through comparative genomic sequence analysis many genes were identified and, among them, several potentially involved in plant-pathogen interaction. The experimental determination of the primary sequence of some markedly expressed proteins for X fastidiosa and the comparison with the nucleic acids sequence of genome identified one of them as being SCJ21.16 (XFa0032) gene product. The comparative analysis of this protein against SWISSPROT database, in special, resulted in similarity with a-hydroxynitrile lyase enzyme (HNL) from Arabidopsis thaliana, causing interest for being one of the most abundant proteins both in the whole cell extract as well as in the extracellular protein fraction. It is known that HNL enzyme are involved in a process termed ""cyanogenesis"", which catalyzes the dissociation of alpha-hydroxinitrile into carbonyle and HCN when plant tissue is damaged. Although the complete genome sequences of X.fastidiosa are available and the cyanogenesis process is well known, the biological role of this protein in this organism is not yet functionally characterized. In this study we presented the cloning, expression, characterization of recombinant HNL from X fastidiosa, and its probable function in the cellular metabolism. The successful cloning and heterologous expression in Escherichia coli resulted in a satisfactory amount of the recombinant HNL expressed in a soluble, and active form giving convenient access to pure enzyme for biochemical and structural studies. Finally, our results confirmed that the product of the gene XFa0032 can be positively assigned as FAD-independent HNLs. (C) 2009 Elsevier Ltd. All rights reserved.

Thermal stability of extracellular hemoglobin of Glossoscolex paulistus: Determination of activation parameters by optical spectroscopic and differential scanning calorimetric studies

Glossoscolex paulistus hemoglobin (HbGp) was studied by dynamic light scattering (DLS), optical absorption spectroscopy (UV-VIS) and differential scanning calorimetry (DSC). At pH 7.0, cyanomet-HbGp is very stable, no oligomeric dissociation is observed, while denaturation occurs at 56 degrees C, 4 degrees C higher as compared to oxy-HbGp. The oligomeric dissociation of HbGp occurs simultaneously with some protein aggregation. Kinetic studies for oxy-HbGp using UV-VIS and DES allowed to obtain activation energy (E(a)) values of 278-262 kJ/mol (DES) and 333 kJ/mol (UV-VIS). Complimentary DSC studies indicate that the denaturation is irreversible, giving endotherms strongly dependent upon the heating scan rates, suggesting a kinetically controlled process. Dependence on protein concentration suggests that the two components in the endotherms are due to oligomeric dissociation effect upon denaturation. Activation energies are in the range 200-560 kJ/mol. The mid-point transition temperatures were in the range 50-65 degrees C. Cyanomet-HbGp shows higher mid-point temperatures as well as activation energies, consistent with its higher stability. DSC data are reported for the first time for an extracellular hemoglobin. (C) 2010 Elsevier B.V. All rights reserved.

A quantum chemical study on the formation of phosphorus mononitride

The chemical mechanism of the (1)PN formation was successfully studied by using the CCSD(T)/6-311++G(3df,3pd) level of theory. The (1)NH(3) + (3)PH and (4)P + NH(3) reaction paths are not energetically favorable to form the (1)PN molecule. However, the (3)NH + (3)PH, (4)N + (3)PH(3), (4)N + (3)PH, (4)P + (3)NH, and (4)P + (2)NH(2) reaction paths to form the (1)PN molecule are only energetically favorable by taking place through specific transition states to form the (1)PN molecule. The NH(3) + (3)PH, (4)N + (1)PH(3), NH(3) + (4)P, and (4)N + (2)PH(2) reactions are spin-forbidden and the probability of hopping for these reactions was estimated to be 0 by the Landau-Zener theory. This is the first detailed study on the chemical mechanism for the (1)PN formation. (C) 2009 Elsevier B.V. All rights reserved.

An Experimental Study of Submerged Entry Nozzles (SEN) Focusing on Decarburization and Clogging

The submerged entry nozzle (SEN) is used to transport the molten steel from a tundish to a mould. The main purpose of its usage is to prevent oxygen and nitrogen pick-up by molten steel from the gas. Furthermore, to achieve the desired flow conditions in the mould. Therefore, the SEN can be considered as a vital factor for a stable casting process and the steel quality. In addition, the steelmaking processes occur at high temperatures around 1873 K, so the interaction between the refractory materials of the SEN and molten steel is unavoidable. Therefore, the knowledge of the SEN behaviors during preheating and casting processes is necessary for the design of the steelmaking processes  The internal surfaces of modern SENs are coated with a glass/silicon powder layer to prevent the SEN graphite oxidation during preheating. The effects of the interaction between the coating layer and the SEN base refractory materials on clogging were studied. A large number of accretion samples formed inside alumina-graphite clogged SENs were examined using FEG-SEM-EDS and Feature analysis. The internal coated SENs were used for continuous casting of stainless steel grades alloyed with Rare Earth Metals (REM). The post-mortem study results clearly revealed the formation of a multi-layer accretion. A harmful effect of the SENs decarburization on the accretion thickness was also indicated. In addition, the results indicated a penetration of the formed alkaline-rich glaze into the alumina-graphite base refractory. More specifically, the alkaline-rich glaze reacts with graphite to form a carbon monoxide gas. Thereafter, dissociation of CO at the interface between SEN and molten metal takes place. This leads to reoxidation of dissolved alloying elements such as REM (Rare Earth Metal). This reoxidation forms the “In Situ” REM oxides at the interface between the SEN and the REM alloyed molten steel. Also, the interaction of the penetrated glaze with alumina in the SEN base refractory materials leads to the formation of a high-viscous alumina-rich glaze during the SEN preheating process. This, in turn, creates a very uneven surface at the SEN internal surface. Furthermore, these uneven areas react with dissolved REM in molten steel to form REM aluminates, REM silicates and REM alumina-silicates. The formation of the large “in-situ” REM oxides and the reaction of the REM alloying elements with the previously mentioned SEN´s uneven areas may provide a large REM-rich surface in contact with the primary inclusions in molten steel. This may facilitate the attraction and agglomeration of the primary REM oxide inclusions on the SEN internal surface and thereafter the clogging. The study revealed the disadvantages of the glass/silicon powder coating applications and the SEN decarburization. The decarburization behaviors of Al2O3-C, ZrO2-C and MgO-C refractory materials from a commercial Submerged Entry Nozzle (SEN), were also investigated for different gas atmospheres consisting of CO2, O2 and Ar. The gas ratio values were kept the same as it is in a propane combustion flue gas at different Air-Fuel-Ratio (AFR) values for both Air-Fuel and Oxygen-Fuel combustion systems. Laboratory experiments were carried out under nonisothermal conditions followed by isothermal heating. The decarburization ratio (α) values of all three refractory types were determined by measuring the real time weight losses of the samples. The results showed the higher decarburization ratio (α) values increasing for MgO-C refractory when changing the Air-Fuel combustion to Oxygen-Fuel combustion at the same AFR value. It substantiates the SEN preheating advantage at higher temperatures for shorter holding times compared to heating at lower temperatures during longer holding times for Al2O3-C samples. Diffusion models were proposed for estimation of the decarburization rate of an Al2O3-C refractory in the SEN. Two different methods were studied to prevent the SEN decarburization during preheating: The effect of an ZrSi2 antioxidant and the coexistence of an antioxidant additive and a (4B2O3 ·BaO) glass powder on carbon oxidation for non-isothermal and isothermal heating conditions in a controlled atmosphere. The coexistence of 8 wt% ZrSi2 and 15 wt% (4B2O3 ·BaO) glass powder of the total alumina-graphite refractory base materials, presented the most effective resistance to carbon oxidation. The 121% volume expansion due to the Zircon formation during heating and filling up the open pores by a (4B2O3 ·BaO) glaze during the green body sintering led to an excellent carbon oxidation resistance. The effects of the plasma spray-PVD coating of the Yttria Stabilized Zirconia (YSZ) powder on the carbon oxidation of the Al2O3-C coated samples were investigated. Trials were performed at non-isothermal heating conditions in a controlled atmosphere. Also, the applied temperature profile for the laboratory trials were defined based on the industrial preheating trials. The controlled atmospheres consisted of CO2, O2 and Ar. The thicknesses of the decarburized layers were measured and examined using light optic microscopy, FEG-SEM and EDS. A 250-290 μm YSZ coating is suggested to be an appropriate coating, as it provides both an even surface as well as prevention of the decarburization even during heating in air. In addition, the interactions between the YSZ coated alumina-graphite refractory base materials in contact with a cerium alloyed molten stainless steel were surveyed. The YSZ coating provided a total prevention of the alumina reduction by cerium. Therefore, the prevention of the first clogging product formed on the surface of the SEN refractory base materials. Therefore, the YSZ plasma-PVD coating can be recommended for coating of the hot surface of the commercial SENs.

Musilian Concept of Modern Man

German-Austrian Robert Musil (1880-1942) is considered an artist with an extremely unorthodox conception of art to a basic human problem. In his time, there existed a dissociation of substance from social values. Musil actually started with this foundation in considering the taunting dilemma that the accelerating technology of the century is overstepping each day the ability of the human mind to adjust to it. Musil maintained that social organization, patterns of thought and cherished ideals correspond to a reality that no longer exists

Escolas de administração e comunidade: a interação necessária : uma investigação sobre a extensão universitária e sua estruturação na Faculdade de Administração da Unversidade Federal Fluminense

Esta dissertação é produto de uma investigação sobre a extensão universitária e as bases institucionais para o seu desenvolvimento. A sua construção teve como norte o objetivo de analisar a estruturação da extensão em uma instituição de educação superior em Administração, o que foi realizado através de explorações teóricas e do estudo de caso da Faculdade de Administração da Universidade Federal Fluminense. Tendo como principal referência o pensamento do Fórum Nacional de Pró-Reitores de Extensão das Universidades Públicas, as dimensões institucionais que orientaram a análise do caso foram: política de gestão, plano acadêmico e infra-estrutura. De acordo com suas caracteristicas atuais na instituição em foco, foi possível compreender que estas bases, que suportam o desenvolvimento da extensão, ainda não estão adequadamente consolidadas. A principal conseqüência deste cenário é o desequilíbrio e dissociabilidade entre ensino, pesquisa e extensão. Isto, por sua vez, gera a prevalência da reprodução de conhecimentos que muitas vezes foram gerados em ambientes com caracteristicas distintas da sociedade brasileira e da comunidade onde a Universidade está inserida. Diante um cenário onde é urgente a necessidade de conhecimentos comprometidos com a solução de problemas que impedem a sustentabilidade do desenvolvimento do Brasil, é necessário que esta instituição se renove para corresponder aos desafios da sociedade atual.

Psicologia social e ideologia: a inserção de um novo/velho conceito e suas consequências para a analise dos fenômenos psico-sociais

O presente trabalho teve por objetivo examinar o surgimento do conceito de ideologia e as transformações que vem sofrendo desde então, tendo como objetivo fundamental sugerir áreas de estudo dentro da Psicologia, particularmente da Psicologia Social, onde a aplicação desta categoria de análise poderia lançar uma luz mais esclarecedora e satisfatória sobre uma série de fenômenos de comportamento, áreas estas que até agora persistem em ignorar os fenômenos ideológicos. Ao final do trabalho foram formuladas críticas severas à maneira pela qual a Psicologia Social vem se realizando no Brasil via EUA, quer a nível metodológico, quer particularmente quanto aos fenômenos por ela estudados. Entre nós se patenteia a ausência e aceitação de enfoques interdisciplinares, bem como a dissociação de tais fenômenos do contexto histórico-político onde ocorrem. Sugeriu-se também a criação entre nós de uma nova área de estudos preferencial para a Psicologia Social - Psicologia Social do proletariado - visando estabelecer, num futuro próximo, um referencial teórico capaz de refletir e compreender realmente a dinâmica social desta classe, isento de comprometimentos classistas, reflexo da ideologia dominante à qual tal classe é tradicionalmente submetida.

Atividade bioinseticida e mecanismo de ação de vicilinas de sementes Erythrina velutina sobre moscas-das frutas Ceratitis capitata

The fruit fly Ceratitis capitata is considered the most destructive pest of the world fruitculture. Many pest management practices, mainly based on agrochemicals, have been developed to allow the world-wide commerce of fruit. Solutions to decrease the use of synthetic insecticides in agriculture are based on the development of new target-specific compounds which cause less damage to the environment, especially vegetal proteins with insecticidal effects. The aim of this work was to evaluate the deleterious effect of a purified vicilin of E. velutina (EvV) seeds to C. capitata larvae and adult insects and to investigate the mechanisms involved in these effects. EvV was purified, characterized and its deleterious effect was tested in bioassay systems. EvV mechanism of action was determined by immunodetection techniques and fluorescence localization in chitin structures that are present in C. capitata digestory system. EvV is a glycoprotein with affinity to chitin. Its molecular weight, of 216,57 kDa, was determined by gel filtration chromatography in FPLC system. Using SDS-PAGE, it was possible to observe EvV dissociation in two main subunits of 54,8 and 50,8 kDa. When it was submitted to eletrophoresis in native conditions, EvV presented only one band of acid characteristic. The WD50 and LD50 values found in the bioassays were 0,13% and 0,14% (w/w), respectively for the larvae. EvV deleterious effects were related to the binding to chitin structures presented in peritrophic membrane and gut epithelial cells, associated with its low digestibility in C. capitata digestive tract. The results described herein are the first demonstration of the larvicidal effects of plant protein on C. capitata larvae. EvV may be part of the pest management programs, in the toxic bait composition, or an alternative in plant improvement program

Avaliação da ação bioinseticida de SBTI e vicilina de Erythrina velutina em enzimas digestivas e membrana peritrófica de larvas de Plodia interpunctella (Lepidoptera: Pyralidae)

Plodia interpunctella (Indian meal moth) is a cosmopolitan pest that attacks not only a wide range of stored grain as well other food products. Due to its economic importance several researches have focused in a method with ability to control this pest with few or no damage to the environment. The study of digestive enzymes inhibitors, lectins and chitin-binding proteins, has often been proposed as an alternative to reduce insect damage. In this study we report the major classes of digestive enzymes during larval growth in P. Interpunctella, being those proteinases actives at pH 9.5 and optimum temperature of 50 oC to both larvae of the 3rd instar and pre-pupal stage of development. In vitro and zymogram assays presented the effects of several inhibitors, such as SBTI, TLCK and PMSF to intestinal homogenate of 3rd instar larvae of 62%, 92% and 87% of inhibition and In pre-pupal stage of 87%, 62 % and 55% of inhibition, respectively. Zymograms showed inhibition of two low molecular masses protein bands by TLCK and that in presence of SBTI were retarded. These results are indicative of predominance of digestive serine proteinases in gut homogenate from Plodia interpunctella larvae. This serine proteinase was then used as a target to evaluate the effect of SBTI on larvae in in vivo assay. Effect of SBTI on mortality and larval mass was not observed at until 4% of concentration (w/w) in diets. Chitin, another target to insecticidal proteins, was observed by chemical method. Moreover, optic microscopy confirmed the presence of a peritrophic membrane. Established this target, in vivo effect of EvV, a chitin binding vicilin, evaluated during the larval development of P. interpunctella and was obtained a LD50 of 0,23% and WD50 of 0,27% to this protein. Mechanism of action was proposed through of the in vivo digestibility of EvV methodology. During the passage through the larval digestive tract was observed that EvV was susceptible to digestive enzymes and a reactive fragment, visualized by Western blotting, produced by digestion was recovered after dissociation of the peritrophic membrane. The bound of EvV to peritrophic membrane was confirmed by immunohystochemical assays that showed strong immunofluorescent signal of EvV-FITC binding and peritrophic membrane. These results are a indicative that vicilins could be utilized as potential insecticide to Plodia interpunctella and a control methods using EvV as bioinsecticide should be studied to reduce lost caused by storage insect pests

Estudo da sinterabilidade de ligas de níquel obtidas por meio dos portadores de liga sic, si3n4 ou si metálico com grafita

Nickel alloys are frequently used in applications that require resistance at high temperatures associated with resistance to corrosion. Alloys of Ni-Si-C can be obtained by means of powder metallurgy in which powder mixtures are made of metallic nickel powders with additions of various alloying carriers for such were used in this study SiC, Si3N4 or Si metal with graphite. Carbonyl Ni powder with mean particle size of 11 mM were mixed with 3 wt% of SiC powders with an average particle size of 15, 30 and 50 μm and further samples were obtained containing 4 to 5% by mass of SiC with average particle size of 15 μm. Samples were also obtained by varying the carrier alloy, these being Si3N4 powder with graphite, with average particle size of 1.5 and 5 μm, respectively. As a metallic Si graphite with average particle size of 12.5 and 5 μm, respectively. The reference material used was nickel carbonyl sintered without adding carriers. Microstructural characterization of the alloys was made by optical microscopy and scanning electron microscopy with semi-quantitative chemical analysis. We determined the densities of the samples and measurement of microhardness. We studied the dissociation of carriers alloy after sintering at 1200 ° C for 60 minutes. Was evaluated also in the same sintering conditions, the influence of the variation of average particle size of the SiC carrier to the proportion of 3% by mass. Finally, we studied the influence of variation of the temperatures of sintering at 950, 1080 and 1200 ° C without landing and also with heights of 30, 60, 120 and 240 minutes for sintering where the temperature was 950 °C. Dilatometry curves showed that the SiC sintered Ni favors more effectively than other carriers alloy analyzed. SiC with average particle size of 15 μm active sintering the alloy more effectively than other SiC used. However, with the chemical and morphological analyzes for all leagues, it was observed that there was dissociation of SiC and Si3N4, as well as diffusion of Si in Ni matrix and carbon cluster and dispersed in the matrix, which also occurred for the alloys with Si carriers and metallic graphite. So the league that was presented better results containing Si Ni with graphite metallic alloy as carriers, since this had dispersed graphite best in the league, reaching the microstructural model proposed, which is necessary for material characteristic of solid lubricant, so how we got the best results when the density and hardness of the alloy

On the temperature stability of extracellular hemoglobin of Glossoscolex paulistus, at different oxidation states: SAXS and DLS studies

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

TORP: The Open Robot Project A Framework for Module-Based Robots

The development of robots has shown itself as a very complex interdisciplinary research field. The predominant procedure for these developments in the last decades is based on the assumption that each robot is a fully personalized project, with the direct embedding of hardware and software technologies in robot parts with no level of abstraction. Although this methodology has brought countless benefits to the robotics research, on the other hand, it has imposed major drawbacks: (i) the difficulty to reuse hardware and software parts in new robots or new versions; (ii) the difficulty to compare performance of different robots parts; and (iii) the difficulty to adapt development needs-in hardware and software levels-to local groups expertise. Large advances might be reached, for example, if physical parts of a robot could be reused in a different robot constructed with other technologies by other researcher or group. This paper proposes a framework for robots, TORP (The Open Robot Project), that aims to put forward a standardization in all dimensions (electrical, mechanical and computational) of a robot shared development model. This architecture is based on the dissociation between the robot and its parts, and between the robot parts and their technologies. In this paper, the first specification for a TORP family and the first humanoid robot constructed following the TORP specification set are presented, as well as the advances proposed for their improvement.

A ação civil pública como meio de concretização do direito à saúde na Constituição de 1988

The work presented here is about aspects of the constitutional extension in which is the public civil action with the objective of verifying its aptitute in tutelaging subjective situations derived from fundamental rights, especially right to health assistance. Thus, it offers a clear analysis of the practical functioning of most aspects of the public civil action (lawsuit), with philosophical foundation and necessary doctrinaire to your comphehension. How it once was (history), how it could be (reform suggestion), how it is (current interpretation of the law) and how it should be (critic analysis of the microsystem of collective tutelaging of rights, its perspectives, as well as the efficacy of the public cilvil action about accomplishment of the right to health as supraindividual right). The objective is to analyse the main version of the theme (for instance: the impacts caused to the dissociation of the Procurations theory), so that it can be extracted the philosophy and the general theory, of the public civil action and collective tutelaging in general, pragmatically applicable to study purposes. With this theorical fountain, the reader will be in a more solid position, not only being able to understand the subtilities of the public civil action, but mainly being able to recognize its faults and present solid reform proposals and improvement. It is know that the Juridical Power (Procuration) does not allow any more inactivity about negating accession to health in its collective dimension (lato sensu: spread, collective stricto sensu and homogeneous individuals), being imputed to it novel usage that consolidates in the assumption of the role instrument set aside to be used by all with organized instancy of solution to collective conflicts in large sense. This happens, overall, because of the current justice politization, understood as juridical activism, connected to the struggle between the groups defending their interests and the acceptance of the constitution about solidifying the public politics of quality health

A modalização como estratégia argumentativa em textos de vestibulandos

In this work, the argumentative strategies construction in university entrance examinations texts is analyzed. The study intended to present, through the analyzed occurrences in the corpus, the discursive strategies use for the argumentation construction, observing the different lexicalization forms and the effects that these strategies produced for the intended meaning construction. Aiming to analyze the modalization via texts written by candidates for the UFRN entrance examination, the relations between this category and the resources used for the argumentative guidance of the text were highlighted. Conceived as a speaker argumentative strategy to express his/her relationship with the proposition content which enunciates, the modalization is, thus, one of the linguistic expression form used for the attainment of intended meaning effects in the argumentation construction. In order to substantiate the research, the theoretical assumptions adopted were the propositions which deal with this linguistic category, guiding it to a pragmatic-semantic perspective as well as a discursive-semantic one. Hence, Neves ( 1996, 2006), Koch ( 2000, 2002), Cervoni ( 1989), Bronkart (1999) and Castilho; Morais de Castilho (1996) studies, among others founded this work. Afterwards, a contextualized analysis of the modalized statements, taking into account all the set of elements implied on the argumentation construction, was carried out. The research, which had a strict qualitative character, revealed that the candidates make use of modalization to express commitment or dissociation as regards the statement which they produce; to obtain credibility and provide more authority to their arguments, thus avoiding them of being contested; to impose their arguments as real ones and acquire acceptance of the interlocutor; to lessen the proposition content and disguise the knowledge source; to comment the enunciation and attribute the discourse to another sender; to establish a dialogic relation with the interlocutor. In addition to offering support for new investigations, the research also aims to contribute for the mother tongue teaching, emphasizing the need of a focus which provides special attention to the written language functioning and its application diversity. In this work, the argumentative strategies construction in university entrance examinations texts is analyzed. The study intended to present, through the analyzed occurrences in the corpus, the discursive strategies use for the argumentation construction, observing the different lexicalization forms and the effects that these strategies produced for the intended meaning construction. Aiming to analyze the modalization via texts written by candidates for the UFRN entrance examination, the relations between this category and the resources used for the argumentative guidance of the text were highlighted. Conceived as a speaker argumentative strategy to express his/her relationship with the proposition content which enunciates, the modalization is, thus, one of the linguistic expression form used for the attainment of intended meaning effects in the argumentation construction. In order to substantiate the research, the theoretical assumptions adopted were the propositions which deal with this linguistic category, guiding it to a pragmatic-semantic perspective as well as a discursive-semantic one. Hence, Neves ( 1996, 2006), Koch ( 2000, 2002), Cervoni ( 1989), Bronkart (1999) and Castilho; Morais de Castilho (1996) studies, among others founded this work. Afterwards, a contextualized analysis of the modalized statements, taking into account all the set of elements implied on the argumentation construction, was carried out. The research, which had a strict qualitative character, revealed that the candidates make use of modalization to express commitment or dissociation as regards the statement which they produce; to obtain credibility and provide more authority to their arguments, thus avoiding them of being contested; to impose their arguments as real ones and acquire acceptance of the interlocutor; to lessen the proposition content and disguise the knowledge source; to comment the enunciation and attribute the discourse to another sender; to establish a dialogic relation with the interlocutor. In addition to offering support for new investigations, the research also aims to contribute for the mother tongue teaching, emphasizing the need of a focus which provides special attention to the written language functioning and its application diversity

Evidence for conformational changes in the yeast deoxyhypusine hydroxylase Lia1 upon iron displacement from its active site

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)