711 resultados para Intrinsically photosensitive


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It is widely acknowledged that the indoleamine neurotransmitter serotonin (5-HT) plays a dual role in the regulation of anxiety, a role that in part depends upon neuroanatomical locus of action. Thus, whereas stimulation of 5-HT1A or 5-HT2 receptors in the limbic forebrain (amygdala, hippocampus) enhances anxiety-like responding in rodents, activation of corresponding receptor populations in the midbrain periaqueductal grey (PAG) more often than not reduce anxiety-like behaviour. The present study specifically concerns the anxiety-modulating influence of 5-HT2 receptors within the mouse PAG. Experiment 1 assessed the effects of intra-PAG infusions of the 5-HT2B/2C receptor agonist mCPP (0, 0.03, 0.1 or 0.3 nmol/0.1 mu l) on the behaviour of mice exposed to the elevated plus-maze. As mCPP acts preferentially at 5-HT2B and 5-HT2C receptors, Experiment 2 investigated its effects in animals pretreated with ketanserin, a preferential 5-HT2A/2C receptor antagonist. In both cases, test sessions were videotaped and subsequently, scored for anxiety-like behaviour (e.g., percentage of open arm entries and percentage of open arm time) as well as general locomotor activity (closed arm entries). The results of Experiment I showed that mCPP microinfusions (0.03 and 0.1 nmol) into the PAG of mice decreased behavioural indices of anxiety without significantly altering general activity measures. In Experiment 2, the anxiolytic-like profile of intra-PAG mCPP (0.03 nmol) was substantially attenuated by intra-PAG pretreatment with an intrinsically inactive dose of the preferential 5-HT2A/2C receptor antagonist, ketanserin (10 nmol/0.1 mu l). Together, these data suggest that 5HT(2C) receptor populations within the midbrain PAG play an inhibitory role in plus-maze anxiety in mice. (C) 2007 Elsevier B.V. All rights reserved.

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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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This paper proposes a combined pool/bilateral short term hydrothermal scheduling model (PDC) for the context of the day-ahead energy markets. Some innovative aspects are introduced in the model, such as: i) the hydraulic generation is optimized through the opportunity cost function proposed; ii) there is no decoupling between physical and commercial dispatches, as is the case today in Brazil; iii) interrelationships between pool and bilateral markets are represented through a single optimization problem; iv) risk exposures related to future deficits are intrinsically mitigated; v) the model calculates spot prices in an hourly basis and the results show a coherent correlation between hydrological conditions and calculated prices. The proposed PDC model is solved by a primal-dual interior point method and is evaluated by simulations involving a test system. The results are focused on sensitivity analyses involving the parameters of the model, in such a way to emphasize its main modeling aspects. The results show that the proposed PDC provides a conceptual means for short term price formation for hydrothermal systems.

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The intrinsically relativistic problem of a fermion subject to a pseudoscalar screened Coulomb plus a uniform background potential in two-dimensional space-time is mapped into a Sturm-Liouville. This mapping gives rise to an effective Morse-like potential and exact bounded solutions are found. It is shown that the uniform background potential determinates the number of bound-state solutions. The behaviour of the eigenenergies as well as of the upper and lower components of the Dirac spinor corresponding to bounded solutions is discussed in detail and some unusual results are revealed. An apparent paradox concerning the uncertainty principle is solved by recurring to the concepts of effective mass and effective Compton wavelength. (c) 2005 Elsevier B.V. All rights reserved.

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The intrinsically relativistic problem of neutral fermions subject to kink-like potentials (similar to tanh gamma x) is investigated and the exact bound-state solutions are found. Apart from the lonely hump solutions for E = +/- mc(2), the problem is mapped into the exactly solvable Sturm-Liouville problem with a modified Poschl-Teller potential. An apparent paradox concerning the uncertainty principle is solved by resorting to the concepts of effective mass and effective Compton wavelength. (c) 2005 Elsevier B.V. All rights reserved.

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The problem of neutral fermions subject to a pseudoscalar potential is investigated. Apart from the solutions for E = +/- mc(2), the problem is mapped into the Sturm-Liouville equation. The case of a singular trigonometric tangent potential (similar to tan gamma x) is exactly solved and the complete set of solutions is discussed in some detail. It is revealed that this intrinsically relativistic and true confining potential is able to localize fermions into a region of space arbitrarily small without the menace of particle-antiparticle production.

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The Klein - Gordon and the Dirac equations with vector and scalar potentials are investigated under a more general condition, V(v) + V(s) = constant. These intrinsically relativistic and isospectral problems are solved in the case of squared hyperbolic potential functions and bound states for either particles or antiparticles are found. The eigenvalues and eigenfuntions are discussed in some detail and the effective Compton wavelength is revealed to be an important physical quantity. It is revealed that a boson is better localized than a fermion when they have the same mass and are subjected to the same potentials.

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Callithrix jacchus, as the other species in the family Callitrichidae, lives in social groups. The groups cam be found in different habitats, whose distinct floristic physiognomies and communities are intrinsically related to their behavioral ecology and social relations. Our objective was to describe the social relations and feeding behavior of Callithrix jacchus in the Bioma Caatinga. We observed a group at the FLONA (National Forest IBAMA), in Açu-RN, in northeastern Brazil, compose of five adults (2 females and 3 males) at the beginning of the study. The birth of five animals was registered along the study. The following behavioral categories were registered along eleven months, once a week, through instantaneous focal animal sampling: social grooming, contact, proximity, foraging, feeding, locomotion and rest. Foraging presented the highest levels comparing to other activities, and was more frequent in the dry season. Social grooming was the second more frequent activity, with higher levels in the rainy season, and between the reproductive couple. We found similar results for proximity. The most explored feeding item was the gum, specially in the rainy season. The most explored species for exudates feeding were Cirus limon (limão) and Pitecolobiun foliolosum (jurema branca). The comparision of fruit and insect ingestion between the seasons showed higher percentage for both in the dry season. The general activity pattern was similar to what is registeded in groups the inhabit the Atlantic Forest. These results indicate the flexibility of the species which survives and reproduces in such physically and biologically different environments

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This article analyzes the electrical parameters of a 3-phase transmission line using a 280-m-high steel tower that has been proposed for the Amazon transmission system in Brazil. The height of the line conductors and the distance between them are intrinsically related to the longitudinal and transverse parameters of the line. Hence, an accurate study is carried out in order to show the electrical variations between a transmission line using the new technology and a conventional 3-phase 440-kV line, considering a wide range of frequencies and variable soil resistivity. First, a brief review of the fundamental theory of line parameters is presented. In addition, by using a digital line model, simulations are carried out in the time domain to analyze possible and critical over-voltage transients on the proposed line representation.

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A catalyst of great interest to the scientific community tries to unite the structure of ordered pore diameter from mesoporous materials with the properties of stability and acid activity to microporous zeolites. Thus a large number of materials was developed in the past decades, which although being reported as zeolites intrinsically they fail to comply with some relevant characteristics to zeolites, and recently were named zeolitic materials of high accessibility. Among the various synthesis strategies employed, the present research approaches the synthesis methods of crystallization of silanized protozeolitic units and the method of protozeolitic units molded around surfactant micelles, in order for get materials defined as hierarchical zeolites and micro-mesoporous hybrid materials, respectively. As goal BEA/MCM-41 hybrid catalysts with bimodal pore structure formed by nuclei of zeolite Beta and cationic surfactant cetyltrimethylammonium were developed. As also was successfully synthesized the hierarchical Beta zeolite having a secondary porosity, in addition to the typical and uniform zeolite micropores. Both catalysts were applied in reactions of catalytic cracking of high density polyethylene (HDPE), to evaluate its properties in catalytic activity, aiming at the recycling of waste plastics to obtain high value-added raw materials and fuels. The BEA/MCM-41 hybrid materials with 0 days of pre-crystallization did not show enough properties for use in catalytic cracking reactions, but they showed superior catalytic properties compared to those ordered mesoporous materials of Al-MCM-41 type. The structure of Beta zeolite with hierarchical porosity leads the accessibility of HDPE bulky molecules to active centers, due to high external area. And provides higher conversion to hydrocarbons in the gasoline range, especially olefins which have great interest in the petrochemical industry

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The role of carboxymethylcellulose (CMC) in association to calcium carbonate particles (CaCO3) in most water-based drilling fluids is to reduce the fluid loss to the surrounding formation. Another essential function is to provide rheological properties capable of maintaining in suspension the cuttings during drilling operation. Therefore, it is absolutely essential to correlate the polymer chemical structure (degree of substitution, molecular weight and distribution of substituent) with the physical-chemical properties of CaCO3, in order to obtain the better result at lower cost. Another important aspect refers to the clay hydration inhibitive properties of carboxymethylcellulose (CMC) in drilling fluids systems. The clay swelling promotes an undesirable damage that reduces the formation permeability and causes serious problems during the drilling operation. In this context, this thesis consists of two main parts. The first part refers to understanding of interactions CMC-CaCO3, as well as the corresponding effects on the fluid properties. The second part is related to understanding of mechanisms by which CMC adsorption occurs onto the clay surface, where, certainly, polymer chemical structure, ionic strength, molecular weight and its solvency in the medium are responsible to affect intrinsically the clay layers stabilization. Three samples of carboximetilcellulose with different molecular weight and degree of substitution (CMC A (9 x 104 gmol DS 0.7), CMC B (2.5 x 105 gmol DS 0.7) e CMC C (2.5 x 105 gmol DS 1.2)) and three samples of calcite with different average particle diameter and particle size distribution were used. The increase of CMC degree of substitution contributed to increase of polymer charge density and therefore, reduced its stability in brine, promoting the aggregation with the increase of filtrate volume. On the other hand, the increase of molecular weight promoted an increase of rheological properties with reduction of filtrate volume. Both effects are directly associated to hydrodynamic volume of polymer molecule in the medium. The granulometry of CaCO3 particles influenced not only the rheological properties, due to adsorption of polymers, but also the filtration properties. It was observed that the lower filtrate volume was obtained by using a CaCO3 sample of a low average size particle with wide dispersion in size. With regards to inhibition of clay swelling, the CMC performance was compared to other products often used (sodium chloride (NaCl), potassium chloride (KCl) and quaternary amine-based commercial inhibitor). The low molecular weight CMC (9 x 104 g/mol) showed slightly lower swelling degree compared to the high molecular weight (2.5 x 105 g/mol) along to 180 minutes. In parallel, it can be visualized by Scanning Electron Microscopy (SEM) that the high molecular weight CMC (2.5 x 105 g/mol e DS 0.7) promoted a reduction in pores formation and size of clay compared to low molecular weight CMC (9.0 x 104 g/mol e DS 0.7), after 1000 minutes in aqueous medium. This behavior was attributed to dynamic of interactions between clay and the hydrodynamic volume of CMC along the time, which is result of strong contribution of electrostatic interactions and hydrogen bounds between carboxylate groups and hydroxyls located along the polymer backbone and ionic and polar groups of clay surface. CMC adsorbs on clay surface promoting the skin formation , which is responsible to minimize the migration of water to porous medium. With the increase of degree of substitution, it was observed an increase of pores onto clay, suggesting that the higher charge density on polymer is responsible to decrease its flexibility and adsorption onto clay surface. The joint evaluation of these results indicate that high molecular weight is responsible to better results on control of rheological, filtration and clay swelling properties, however, the contrary effect is observed with the increase of degree of substitution. On its turn, the calcite presents better results of rheological and filtration properties with the decrease of average viii particle diameter and increase of particle size distribution. According to all properties evaluated, it has been obvious the interaction of CMC with the minerals (CaCO3 and clay) in the aqueous medium

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Despite the improvement of Brazilian s living conditions in recent decades, this improvement occurred in a polarized way between groups of better social position. Then, there is still a health inequity´s panorama in Brazil which encompasses the oral health state. This panorama instigated the attainment of this ecological study that aimed to evaluate the relationship of socioeconomic conditions, and public health policies with oral health status in Brazilian capitals. Thus, we performed factor analysis and linear regression using oral health indicators collected from SB Brasil 2010, of socioeconomic conditions from Brazilian Census 2010 and related to water´s supply fluoridation from SISAGUA. Factor analysis with indicators of living conditions revealed two common factors, economic deprivation and socio-sanitary condition. Economic deprivation showed statistically significant positive correlation with DMFT 12 years (p= 0,03) and mean missing teeth (p = 0,002) and negative correlation with caries-free population (p=0,012). Socio-sanitary negatively correlated with DMFT (p <0,0001) and a positive correlation with caries-free population (p = 0.002). Fluoridated water had a significant association with DMFT (p <0,0001), mean missing teeth (p <0,0001) and caries free population (p <0.0001). Multiple linear regression analysis for the DMFT of capital was estimated by socio-sanitary condition and fluoridation, adjusted by economic deprivation, whereas the model for the mean missing teeth was estimated only by fluoridation and economic deprivation, and finally the model the rate for the population free of caries in Brazilian capitals was estimated by economic and socio-sanitary status adjusted fluoridated water supply. Therefore, factors related to living conditions and public policies are intrinsically linked to tooth decay issues. Thus, actions, beyond dental care assistance, must be development to impact positively in social and economic conditions, especially, between the most vulnerable populations

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This work has as objective to reflect about the insertion of the women in the City Council of Natal in the period from 1988 to 2004. We focused our discussion in the context of the politics of quota that has with objective to decrease the frame of inequalities existent between women and men in the politics, besides of to analyze which the determinants responsible for the women's sub-representation. The research still consists of an analysis of the councilor s women profile and how they were seen in that space of power. We analyzed our study object in a gender vision, since this is related intrinsically the social relationships and the relationships of power. The women, for a long time, they were excluded of the participation in the public life, being just seen as mere expectants. This research is informed mainly by studies which discuss the Gender (Scott, 1990), (Perrot, 1988), (Badinter, 1995), (Bruschini, 2002). We also analyzed the power, politics in the vision of Marx (1996), Foucault (1982) and (Arendt, 2001). We tried to analyze the women's presence in the spaces public and private, showing your conflicts and contradictions faced in the society, focalizing the political character of the women's inclusion in the spaces in that are inserted. The instrument of collection of data was the semi-structured questionnaire, descriptive and analytical - critical. The analyses of the interviews show to the sub-representation of women over the years as a determining factor for these women continue in the invisibility. The women were interviewed councillora ex- bounded from 1988 to 2004. The conclusion the one that we arrived is that this sub-representation has as decisive the patriarchal system that prevailed for a long time in our society and still dominates and affects women in all areas of your life. This becomes more serious in the capitalist society in which prevail the interests of those that it stops the produced wealth

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The process of development of any area is closely linked to teaching and research, and in Tourism it is not different. Thus, in this area in which service is one of the factors intrinsically related to its success , it is observed the need for people with deep and critical training in the various aspects of this activity acting in this sector. However, we can see the existence of some differences between what is offered by the academy from what is required by the market. Therefore, the objective of this research is to verify the relationship between higher education in Tourism and labor market through the perception of the bachelor in this area, graduated in Natal-RN, since it is the tourismologist who makes the link between this two fields. To know the perception of these tourismologists, it was necessary to apply a questionnaire to those ones graduated in the years 2009 and 2010. In accordance with the aim of this study, this research was exploratory-descriptive. Related to the technical procedures, it was a documentary, literature and field research. To have it analyzed, some qualitative and quantitative techniques were applied according to our specific objectives and the types of data collected, such as: content analysis, factorial analysis to synthesize the information and identify the basic dimensions that represent the different variables studied, the standard deviation to verify the variation of the responses in some items and the correlation technique that allows the analysis of the relationship between two variables. In response to the objectives proposed here, we could finally conclude that: the syllabuses of these courses are too general and the graduates themselves consider them so. It was diagnosed that the graduates 1) are mostly female, 2) a very small part of them is working in the area that they are graduated in, and 3) not all of them receive satisfactory wages which contributes to having a negative view of their degree course. Moreover, the educational institution where they studied was not a decisive factor to get a job. It was still diagnosed that most part of them do not have positive perceptions when thinking about the future of their careers as bachelors in Tourism. Many of them, including, if it was possible to change something in their careers so far, they could have chosen another college degree. It was found that, although there is a negative perception about their professional future, almost half of them believe that the course met the needs of the market. However, those ones that are not working have a more positive point of view related to the applicability of higher education. On the other hand, the other ones who already worked in this area have a more negative perception about it and do not believe that the course meets the market's needs. In summary, this study allowed the understanding of the existence of some gaps that exist between higher education in Tourism and the market needs, professionally speaking, thus contributing to the spreading of ideas on that subject for teachers, researchers and the current and future students of the area.