40 resultados para Válvulas de duas Vias


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The decoction of Brazilian pepper tree barks (Schinus terebinthifolius, Raddi), is used in medicine as wound healing and antiinflamatory. Once extracts from this plant are used for acceleration of scar s process, it is important to study their mutagenic and genotoxic potential. In previous works in our laboratory, it was observed mutagenicity caused by the decoction when in high concentrations. Among the chemical compounds of this plant that could be able to induce mutation, the flavonoids were the only group that was referred to have either an oxidant or antioxidant potential. The flavonoids were isolated, purified and quantified by adsorptive column chromatography under silica gel, bacterial and in vitro genotoxic tests were realized to determine if the flavonoids were the responsible agents for this mutagenicity found. The tests realized with plasmidial DNA were indicative that the flavonoids are probably genotoxic, due to the presence of correlation between increase of the flavonoid concentration and in plasmidial DNA double strand breakage visualized in agarose gel, as well as they were capable to generated abasic sites shown by the in vitro treatment with exonuclease III. The same tests with plasmidial DNA in the presence of copper [10 µM] and of a Tris-HCl pH 7.5 [10 µM] buffer were realized with the isolated flavonoids to determine if there would be or not participation of reactive oxygen species (ROS). The transformation of plasmidial DNA in different bacterial strains proficient and deficient in DNA repair enzymes in the presence or not of a Tris-HCl buffer, suggests that the enzymes that repair oxidative lesions are necessary to repair the lesions generated by the flavonoids and that ROS are generated and are necessary to promote the lesions. Bacterial tests with Escherichia coli strains of the CC collection (deficient or not for DNA repair enzymes), showed that the flavonoids are able to increase the frequency of mutations, mainly in strains mutated in repair enzymes (MutM, MutY-glicosylases and double mutant), suggesting that these agents are responsible for the enhancement in the mutation rate. In order to determine the mutation spectrum caused by the flavonoids of the Brazilian pepper tree stem bark, plasmidial DNA previously treated with the flavonoids were transformed in bacterial strains deficient and proficient in the DNA repair enzymes, followed by a blue-white selection with X-gal, DNA amplification by PCR and sequencing the positive mutant clones. Analysis of the mutants obtained from strains CC104, CC104mutM, CC104mutY, CC104mutMmutY, BW9101, BW9109 indicated a predominance of some mutations like G:C to C:G that can be correlated with the origin of 8-oxoG, due to oxidative lesions caused by the flavonoids. So it can concluded that the flavonoid isolated or in fractions enriched on them are genotoxic and mutagenic, and their mutations are predominantly oxidative, mediated by ROS, and the lesions are recognized by the BER system. In this way it is proposed that the flavonoids can act in two different ways to generate the DNA lesion: 1. in a Fenton-like reaction, when the flavonoid are in the presence of metal ions and that together with the water generate ROS that promotes the DNA lesions; 2. in another way the lesions can be generated by the formation of ROS due to the internal chemical structure of the flavonoid molecule due to the quantity and location of hydroxyl groups, and so producing the DNA lesions, those lesions can be directly (suggested by the in vitro experiments) or indirectly done (supported by the experiments using the CC bacterial strains)

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The 1988 Constitution was the legal marc to define changes in Brazilian State with major importance to the layout of public politician. In that moment of redefinitions e openness to new ways the redemocratization, participation and decentralization of public school had as their starter the elementary school. This work focus on the manage of FUNDESCOLA, particularly one of its politics called PDE (Educational Development Plan) wich purpose is guarantee a better quality in teaching and spread out democracy throughout its methodology. It was chosen two public schools: Professor Ulisses de Góis and Antonio Campos. The theoretical and methodological orientation is based on the theory of participative democracy developed by authors such as Putnam and Pateman. They says that a cultural background precedes individual participation in society. The collected data (educational legislation, surveys with all sectors of schools and technicians of Natal educational secretary, and relevant documents of de institutions) showed that PDE. Implementation had opposite runnings in the schools studied. In one, as a consequence of bad preparations of its teachers to absorve its methodology, PDE failed. In another way, PDE achieved its goals, especially helping the structure of action plans of the school and the administrative organization making possible several pedagogic activities planned. The work concludes that the main factor the failure or success of PDE relies on the organizational (both political and pedagogical) structure of each school. This discovery implies three important guidelines when comes to formulation of public politicians: a) Constitution of school; b) the local actors who manages the actions; c) the colletive interest in taking part of decisions

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Observing that social capital is considered crucial for the consolidation of an association, this paper analyzes how different groups associative absorb the concept of membership and how to manage routing in their actions to the social interest. The research aimed to evaluate two central forms of association, based on the concept of Pierre Bourdieu (1980) on social capital, stressing that its distribution and perception are uneven and depends on the ability of ownership of different social groups. Accordingly, took up two organizations community based one in - Barra do Rio and another in Maracajaú - whose main activity is the exploitation in the coastal tourist norteriograndense. Once processed the data, it became clear that, despite the purpose for the association has been motivated by exploration in both organizations, each differently appropriates its capital. While one maintains a feelings of togetherness, trust and satisfaction of group work, the other one, feelings are stifled by individualism, mistrust among their members that although they see the association as something important for the growth and strengthening of the group, working individually

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This thesis deals with the intellectual itinerary of the humanist, lawyer and educator RN Helio Vasconcelos in building a more cohesive society, just and egalitarian, less marked by inequality, by poverty, ignorance and lack of freedom of his people suffered and loved. It also shows, as after suffering the hardships caused by the political persecution and imprisonment, exile faced with dignity, developing an exemplary job of defending the rights of children and adolescents. For this, redo the way that intellectual humanist, simple man who never gave up their way of thinking, of viewing the world, to love and respect all that surrounds him, thinking globally and acting locally, always holding the defense Rights human. Helium shows how solidarity exercised intensely and as bothered with the real interests of the community to hold public office. It seeks to demonstrate the need for reformulation of Legal Education in order to stimulate the formation of a lawyer gifted humanist profile

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Tropical environments often face strong seasonal variations in climate, such as alternate periods of dry and rain, that may often be important influence in the annual X the organisms lives. Here we assess how population dynamics of two butterfly species (Heliconius erato and Heliconius mepomene) respond to environmental and seasonal variations. A mark-release-recapture study carried out in an Atlantic forest reserve, 15 Km from Natal, Rio Grande do Norte, Brazil, for 3 years, during the dry and rainy season, with three visits weekly done. Information such as species, wing lenght, site of capture, pollen load and phenotype (number of spots) (in H. erato only) were noted for each capture. Seasonal variation exists in capture rates of the two species, with great capture rates during the rainy season. Despite finding differences in the mean density of individuals of the two species among the different collection areas, this difference was only significant between floodplain and central areas, and no influence of seasonality was observed in the mean density between the areas. Seasonality in wing size was only observed for H. erato, with larger wings during the rainy season. Females carried larger pollen loads than males both species, but species were similar. Only males differed seasonally, with larger pollen loads during the rainy season. The distribution of the number of wing spots did not vary between the dry and rainy seasons, and the number of spots in males and females was similar. Therefore, we conclude that there was a strong influence of seasonal variation in the population dynamic of the two Heliconius species, as well as in several aspects of their biology

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Based on climate data and occurrence records, ecological niche models (ENM) are an important opportunity to identify areas at risk or vulnerable to biological invasion. These models are based on the assumption that there is a match between the climatic characteristic of native and invaded regions predicting the potential distribution of exotic species. Using new methods to measure niche overlap, we chose two exotic species fairly common in semi-arid regions of South America, Prosopis juliflora (Sw.) D.C. and Prosopis pallida (H. ; B. ex. Willd) HBK, to test the climate matching hypothesis. Our results indicate that both species occur with little niche overlap in the native region while the inverse pattern is observed in the invaded region on South America, where both species occur with high climatic overlap. Maybe some non-climate factor act limiting the spread of P. pallida on the native range. We believe that a founder effect can explain these similarities between species niche in the invaded region once the seeds planted in Brazil came from a small region on the Native range (Piura in Peru), where both species occur sympatric. Our hypothesis of a founder effect may be evident when we look at the differences between the predictions of the models built in the native and invaded ranges. Furthermore, our results indicate that P. juliflora shows high levels of climate matching between native and invaded ranges. However, conclusions about climate matching of P. pallida should be taken with caution. Our models based on climatic variables provide multiple locations suitable for occurrence of both species in regions where they still don t have occurrence records, including places of high interest for conservation.

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How ecologically similar species are able to coexist has always generated great interest in the scientific community. Classical niche theory predicts that species coexistence is only possible when they segregate in at least one dimension of the ecological niche, thus leading to ecological differentiation among species. However, recent work has shown that species that are more similar in some ecological traits are the ones more prone to be able to coexist (environmental filter). The knowledge of how these forces act shaping ecological communities can reveal co-existence strategies, providing important information for management and conservation of the species. This study tested these hypotheses using a pair of coexisting species of Herpsilochmus, H. pectoralis and H. sellowi. In this study I use high resolution (50 x 50 m) ecological niche models to Identify which environmental factors best predict species occurrence. Next, I calculate the overlap in habitat use by species and build null models to test the hypothesis of spatial niche segregation. In addition, I obtain the selectivity parameters of habitat use to test whether the species H. pectoralis (larger body size) is less selective than H. sellowi (smaller body size) as stated in the literature for other species. The results reject the ecological equivalence among species, revealing that the species of Herpsilochmus explore the habitat differently, having different environmental niches. The hypothesis of environmental filter was not observed in my analysis, the observed overlap in habitat use among species was lower than expected by chance. Evidence that Herpsilochmus are spatially segregating reinforces the hypothesis of interspecific competition as the predominant force in the selection of microhabitat of the species. However, more data and experiments are necessary to state categorically that the observed pattern is a result of current or past competition

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This project has resulted from a reunion between me and two teachers with whom I had already worked, pedagogically counseling them during the execution of the Project of Youngsters and Adults Schooling at the Agrarian Reform Settlements in the State of Sergipe (PAJA/PRONERA) between 2002 and 2003. The matter that really motivated the research was related to the essential principle that guided the accomplishment of the PAJA s teachers education and professionalization: understanding their reality and knowing their needs, promoting the dialogue between scientific and common sense knowledge. Taking as a reference the fact that the teachers education is not restricted to the academic qualification, that is, that it is a part of the educational process, which, in turn, is a result of each one s personal background, dialectically individual and collective, the access to the teachers reality and needs was accomplished by studying their backgrounds, especially their school and professional career. They, inevitably, focused themselves on the country life s social and cultural context, that could be better understood by living together with the teachers during the twenty-seven days I stayed in the Golfo s settlement, located in the town named Pacatuba/SE. The approach to the teachers lives through their stories and the daily contact proved how much Science is still distant from the peasants routine, sometimes being presented to them as a finished product . That way, the dialog between those two categories and the expectation of the country life s social and cultural conditions, together with the education, in which teachers have an essential role, still remain as a challenge

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It is a descriptive, exploratory study, quantitative comparative approach, whose general objective was to analyze the violence at school in a comparative way in the context of two schools in Natal / RN. The specifics were to identify the types of manifestations of violence in the contexts of public and private schools, to identify the position of the leadership, teachers and school staff during and after the occurrence of manifestations of violence in the school environment, to identify measures to prevent violence within of schools. The results show that 68 of the 121 participants (56.20%) were female and 53 (43.80%) were male, 38 (31.40%) were between 40 and 49, 85 (70.2%) lived in the south of Natal (RN), 46 (38.02%) specialization, 68 (56.20%) were Catholic, 63 (52.07%) married, 41 (33.88%) received between 03 and 05 and 68 minimum wages (56.20%) were teachers, 51 (42.15%) 02 employees (01,65%) and directors, 46 (38.02%) providers had between 05 and 14 years and 11 months experience in teaching 70 (57.85%) less than five years in the job, 68 (56.20%) worked between 20 hours and 40 hours per week, 81 (16.30%) worked in the 9th grade of elementary school II. As for the sizing of violence, 111 (91.74%) respondents witnessed episodes of this event who work in the institution, 100 (82.64%) witnessed verbal violence, 87 (71.90%) called for parents when some event happenedviolent that it caused injury to students, 66 (54.55%) believed that family violence is the main reason for young people practiced bullying, 44 (38.98%) reported daily episodes of bullying, 64 (52.89% ) the event happens in the courtyard. Of the 37 victims of violence at school, 22 (59.45%) suffered verbal abuse, 18 (48.65%) experienced violence once a week, 36 (97.30%) were attacked by students, 104 (85.95 %) are able to differentiate the bad acts of bullying behavior, 28 (23.14%) separated the involved coordination and communicated verbally, 23 (19.00%) stated that the coordination of schools talked with parents about the aggressive behavior of the student. Regarding the actions taken to minimize bullying, 69 (57.02%) participated in any professional education process, 47 (38.84%) was the educational process at another institution, 49 (71.01%) took courses lasting 12 to 24 hours, 59 (48.76%) stated that interaction with parents and family was the most stimulated by the school to try to minimize and prevent the event and 116 (95.87%) participated in meetings at the institutions surveyed , 58 (50.00%) responded that the meetings took place every two months and 121 (100.00%) reported having no refresher course on school violence in the schools surveyed. We conclude that violence in schools has been expressed in any social class and that professionals are poorly prepared to deal with the situation. So we hope that education professionals through the reading of our study may realize that school violence takes place in any institution affecting the lives of all who make up the educational universe. It is extremely important that these professionals always seek to empower through knowledge so that they can develop strategies to prevent and minimize the bullying to change the reality of the workplace

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This work aims to promote design aspects into furniture Small and Medium Enterprises (SME s) at Rio Grande do Norte State. The final outcome will be an increasing on their competitiveness as well as consider design as key strategic aspect for their business. As a consequence, the results are based on two SME companies from the furniture sector located at Natal/RN. The study is based on a literature research followed by a management diagnosis for each company. The diagnosis was base don interviews with the entrepreneurs and their employees as well as meetings, participant observations and document analysis. Based on this analysis, specific aspects were implement in order to boost the production line as well as the product development process (PDP) and the development of a prototype. The results have indicated some limitation of these companies regarding their low technological on their production line, poor management and work skills as well as low perception of design as a competitive tool. Regardless these results, it was observed that design has brought an important contribution for cultural changes within companies as well as for the development of better quality and competitive products

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In the current conjuncture, the environmental factor has been changing the position of companies that are practicing or minimally adopting environmental management. Such tool has been used by companies to face the problems caused by solid waste, in particular green coconut waste, which is constantly among the material discarded by society (companies/ consumer). It is a typical tropical fruit whose fresh water is very benefic for human health, and its popularization has caused a progressive increase of its consumption. Following this stream of thought, this present work came up with an analysis of strengths, weaknesses, threats, and opportunities SWOT analysis on green coconut solid waste management at two agribusiness companies in the state of Rio Grande do Norte (RN), Brazil, aiming to know the challenges and the potentials of this kind of waste. According to the approach of the problem, this work fits a descriptive, exploratory, and qualitative research. The data collection was obtained by a questionnaire and a structured interview, in order to evaluate the strategic posture of agribusiness companies through SWOT analysis, which is an English acronym for Strengths, Weaknesses, Opportunities and Threats. The SWOT analysis is an effective tool to analyze the internal and external environment of an organization. This tool contributes to locate the company at the environment in question and when well applied it enables the detection of mistakes, the strengthening of correct procedures, the avoidance of threats, and the bet on opportunities. The studied agribusiness industries have very similar profiles, such as a long business life span, and a strategy that extends the useful life of the fruit, by using its waste for the manufacturing of new subproducts. In both, the daily quantity of waste resulted of this process reaches approximately 20 thousand units of the fruit in high season, being necessary a focus directed at use and/or treatment of these waste. Further to SWOT analysis, it was ascertained that the agribusiness company A works through a defensive marketing strategy and acts vulnerably, in other words, unable of acting before this market segment, for it has decided to stop using the waste due to a lack of equipment and technology. On the other hand, the agribusiness company B has incorporated an offensive marketing strategy because even not possessing equipments, technology, and appropriated internal installations, it still insists on use and benefits of green coconut waste in its agribusiness. Thus, it is considered that the potential of green coconut waste management for the production of several subproducts reduces the impacts produced by inappropriate placement and generates profits in a short, medium and long term. Such profits being tangible and intangible, as the interest for sustainability actions is not only a matter of obtaining return on capital, but it is an important question in order to move on into business, since it is not enough to have quality on products and process nowadays. It is necessary to establish socio-environmental practices aiming the image of the company as the prevailing role on consumers buying decision

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Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters

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This work proposes a collaborative system for marking dangerous points in the transport routes and generation of alerts to drivers. It consisted of a proximity warning system for a danger point that is fed by the driver via a mobile device equipped with GPS. The system will consolidate data provided by several different drivers and generate a set of points common to be used in the warning system. Although the application is designed to protect drivers, the data generated by it can serve as inputs for the responsible to improve signage and recovery of public roads

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Recently, an amazing development has been observed in telecommunication systems. Two good examples of this development are observed in mobile communication and aerospace systems. This impressive development is related to the increasing need for receiving and transmitting communication signals. Particularly, this development has required the study of new antennas and filters. This work presents a fullwave analysis of reflectarrays. The considered structures are composed by arrays of rectangular conducting patches printed on multilayer dieletric substrates, that are mounted on a ground plane. The analysis is developed in the spectral domain, using an equivalent transmission line method in combination with Galerkin method. Results for the reflection coefficient of these structures are presented and compared to those available in the literature. A good agreement was observed. Particularly, the developed analysis uses the transmission lines theory in combination with the incident potentials and the field continuity equations, at the structures interfaces, for obtaining the scattered field components expressions as function of the patch surface currents and of the incident field. Galerkin method is used to determine the unknown coefficients in the boundary value problem. Curves for the reflection coefficient of several reflectarray geometries are presented as function of frequency and of the structural parameters

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It presents a solar collector to be used in a system for heating water for bathing, whose main characteristics are its low cost and easy manufacturing and assembly. The absorbing surface of the collector is formed by an aluminum plate with eight flaps where they lodge PVC pipes. The catchment area of solar radiation corresponds to 1.3 meters. The collector box was made of wood, is covered by transparent glass and thermal insulation of tire chips and expanded polystyrene (EPS). Absorber tubes were connected in parallel through the use of PVC fittings and fixed to the plate by the use of metal poles and rivets. The entire absorber received paint flat black for better absorption of sunlight. The system worked on a thermosiphon assembly and absorber of the collector has been tested in two configurations: with the tubes facing up, directly exposed to the impact of sunlight and facing down, exchanging heat with the plate by conduction. It was determined the most efficient configuration for the correct purpose. The solar collector was connected to a thermal reservoir, also alternative, low-cost forming the system of solar water heating. We evaluated thermal parameters that proved the viability of the heating system studied