Showing papers by "Universidade Federal de Santa Catarina published in 2001"

Empirical diagnostics of the starburst-agn connection

Abstract: We examine a representative sample of 35 Seyfert 2 nuclei. Previous work has shown that nearly half (15) of these nuclei show the direct (but difficult to detect) spectroscopic signature at optical/near-UV wavelengths of the hot massive stars that power circumnuclear starbursts. In the present paper we examine a variety of more easily measured quantities for this sample, such as the equivalent widths of strong absorption features, continuum colors, emission line equivalent widths, emission line ratios and profiles, far-IR luminosities, and near-UV surface brightness. We compare the composite starburst + Seyfert 2 nuclei to "pure" Seyfert 2 nuclei, Starburst galaxies, and normal galactic nuclei. Our goals are to verify whether the easily measured properties of the composite nuclei are consistent with the expected impact of a starburst and to investigate alternative less demanding methods to infer the presence of starbursts in Seyfert 2 nuclei, applicable to larger or more distant samples. We show that starbursts do indeed leave clear and easily quantifiable imprints on the near-UV to optical continuum and emission line properties of Seyfert 2's. Composite starburst + Seyfert 2 systems can be recognized by: (1) a strong "featureless continuum" (FC), which dilutes the Ca II K line from old stars in the host's bulge to an equivalent width WK < 10 A; (2) emission lines whose equivalent widths are intermediate between starburst galaxies and "pure" Seyfert 2's; (3) relatively low excitation line ratios, which indicate that part of the gas ionization in these Seyfert 2's (typically ~50% of Hβ) is due to photoionization by OB stars; (4) large far-IR luminosities (1010 L☉); (5) high near-UV surface brightness (~103 L☉ pc-2). These characteristics are all consistent with the expected impact of circumnuclear starbursts on the observed properties of Seyfert 2's. Furthermore, they offer alternative empirical diagnostics of the presence of circumnuclear starbursts from a few easily measured quantities.

Self-balancing of the clamping-capacitor-voltages in the multilevel capacitor-clamping-inverter under sub-harmonic PWM modulation

Abstract: The paper explores the spontaneous coupled clamping-capacitor-current control loops and the resultant self-balancing property of the clamping-capacitor-voltages in the multilevel capacitor-clamping-inverter. The case of the three-level capacitor-clamping-inverter under sub-harmonic PWM modulation is dealt with first. The case of the multilevel capacitor-clamping-inverter (M>3) under sub-harmonic PWM modulation is then analyzed. Test results on a half-bridge three-level capacitor-clamping-inverter prototype under sub-harmonic PWM modulation are demonstrated.

Fármacos e fitoterápicos: a necessidade do desenvolvimento da indústria de fitoterápicos e fitofármacos no Brasil

Abstract: We discuss briefly the development and the present status of medicinal chemistry. In this context, we consider the therapeutic possibilities of the phytotherapy. On the basis of this analysis, the development of the phytopharmaceutical industry in Brazil is shown to be of essential importance for both the university and the Country due to the human and technological resources involved.

Influence of season and pollution on the antioxidant defenses of the cichlid fish acará (Geophagus brasiliensis)

Abstract: The livers of Geophagus brasiliensis collected from both a non-polluted site and a polluted site were analyzed for different antioxidantdefenses, O 2 consumption, thiobarbituric acid-reactive substance(TBARS) levels, and histological damage. Compared to controls(116.6 – 26.1 nmol g -1 ), TBARS levels were enhanced at the pollutedsite (284.2 – 25.6 nmol g -1 ), as also was oxygen consumption (86.6 –11.3 and 128.5 – 9.8 µmol O 2 min -1 g -1 , respectively). With respect toenzymatic antioxidants, increased catalase activities (8.7 – 1.3 and29.2 – 2.4 mmol min -1 g -1 , respectively), unchanged superoxide dis-mutase activities (767.2 – 113.3 and 563.3 – 70.2 U g -1 , respectively),and diminished glutathione S-transferase activities (29.0 – 3.2 and14.9 – 3.2 µmol min -1 g -1 , respectively) were detected. Reducedglutathione (1.91 – 0.17 and 1.37 – 0.25 mM, respectively), oxidizedglutathione (1.50 – 0.20 and 0.73 – 0.17 mM, respectively), and totalglutathione (3.40 – 0.26 and 2.07 – 0.27 mM, respectively) concentra-tions were also below control values at the polluted site. Nevertheless,the observed ethoxyresorufin-

Health risk behaviors, health status self-assessment and stress perception among industrial workers

Abstract: OBJETIVO: Identificar a prevalencia e analisar a associacao entre comportamentos de risco a saude, percepcao de estresse e auto-avaliacao do nivel de saude, em trabalhadores da industria. METODOS: Estudo epidemiologico transversal, utilizando questionario previamente testado em estudo-piloto realizado em Santa Catarina, Brasil. Foram coletados dados sobre fumo, abuso de alcool, consumo de frutas e verduras, atividades fisicas, percepcao de estresse e auto-avaliacao do nivel de saude de 4.225 trabalhadores (67,5% homens e 32,5% mulheres). Os sujeitos foram recrutados por meio de amostragem por conglomerados em tres estagios (erro de 5%). A analise estatistica incluiu o teste de qui-quadrado e a analise de regressao logistica, para um nivel de significância de p<0,05. RESULTADOS: A media de idade dos sujeitos foi de 29,7 anos (DP=8,6). A prevalencia de fumantes foi de 20,6%, maior entre os homens (23,1%) que entre as mulheres (15,6%). A proporcao de trabalhadores que abusaram de alcool foi alta (57,2% entre os homens e 18,8% entre as mulheres). Dos sujeitos, 46,2% nao realizaram atividades fisicas no lazer (67% das mulheres e 34,8% dos homens), e 13,9% referiram niveis elevados de estresse e dificuldade para enfrentar a vida. Aproximadamente 15% dos trabalhadores relataram nivel de saude regular ou ruim. Sexo, idade, estado civil, numero de filhos, nivel educacional e economico estiveram significativamente associados a prevalencia de comportamentos de risco. CONCLUSOES: Mesmo considerando as limitacoes inerentes aos estudos transversais, e baseados em medidas auto-relatadas, os resultados sugerem elevada prevalencia de abuso de bebidas alcoolicas e inatividade fisica de lazer. A associacao observada entre sexo e comportamento de risco definiu um perfil bidimensional: nos homens os comportamentos de risco mais prevalentes tomaram a forma de risco direto/ativo (fumar, abuso de bebidas alcoolicas), e nas mulheres tomaram a forma de risco indireto/passivo (inatividade fisica, estresse).

Alfabetização científico-tecnológica para quê?

Abstract: Increasingly, t echnological-scientific literacy has been postulated while fundamental dimension in the social dynamics related to technological-scientific development. However, technological-scientific literacy covers a wide spectrum of meanings. The objectives are diverse and diffuse. This paper discusses technological-scientific literacy according to reductionistic and broad perspectives. The reductionism, in ou r analysis, does not consider the e xistence o f constructions that underlie the production of technological-scientific knowledge, such as the one that leads to the conception of science and technology neutrality. This conception can be related to myths which a re called superiority of technocratic decisions’ model, t echnological-science saving perspective and technological determinism. The b road perspective, proposed in this work, aims to comprehend the interactions among Science-Technology-Society (STS), associating the learning of concepts to the myths discussions.

Calibração de examinadores para estudos epidemiológicos de cárie dentária

Abstract: The aim of this study was describe a training and calibration exercise for dental caries and to discuss the use of validity and reliability statistical tests Eight dentists examined seventeen 12 year-old schoolchildren using World Health Organization (1997) criteria Data analysis included calculation of the DMF-T index, the percent agreement, and the kappa scores on a tooth-by-tooth basis Inter-examiner agreement was tested against a gold standard examiner Scores for measures of agreement calculated on a tooth-by-tooth basis were lower than those calculated for the whole mouth The training and calibration exercise is a crucial step in cross-sectional epidemiological surveys, and the kappa test calculated on a tooth-by-tooth basis is the appropriate measurement to test agreement between examiners for dental caries

Empirical diagnostics of the starburst-AGN connection

Abstract: We examine a representative sample of 35 Seyfert 2 nuclei. Previous work has shown that nearly 1/2 of these nuclei show the direct (but difficult-to-detect) spectroscopic signatures at optical-UV wavelengths of the hot massive stars that power circum-nuclear starbursts. In this paper we examine a variety of more-easily-measured quantities for this sample, such as the equivalent widths of strong absorption features, continuum colors, emission line equivalent widths, ratios and profiles, far-IR luminosities and near-UV surface brightness. We compare the composite starburst+Seyfert 2 nuclei to ``pure'' Seyfert 2's, Starburst galaxies and normal galactic nuclei. Our goals are to verify whether these properties in composite nuclei are consistent with the expected impact of a starburst, and to investigate alternative less-demanding methods to infer the presence of starbursts in Seyfert 2's, applicable to larger or more distant samples. We show that starbursts do indeed leave clear and easily quantifiable imprints on the near-UV to optical continuum range. Composite starburst+Seyfert 2 systems can be recognized by: (1) a strong ``Featureless Continuum'' which dilutes the CaII K line from the host's bulge to W_K 10^10 Lsun); (5) High near-UV surface brightness (~10^3 Lsun/pc^2). These characteristics are all consistent with the expected impact of circum-nuclear starbursts on the observed properties of Seyfert 2's. (abridged)

Antioxidant capacity of phenolic and related compounds: correlation among electrochemical, visible spectroscopy methods and structure–antioxidant activity

Abstract: We investigated the antioxidant activity of phenylpropionic acids – caffeic (CAF), ferulic (FER), para-coumaric (COU) and cinnamic (CIN) – and phenolic acids and related compounds – gallic (GAL), methyl gallate (meGAL), vanillic (VAN) and gentisic (GEN) – using visible spectroscopy, inhibition of nitroblue tetrazolium (NBT) reduction, and electrochemical methods including cyclic voltammetry and potentiometry. In the spectroscopic assays, only CAF, GAL and meGAL were able to inhibit NBT reduction. The same compounds showed the lowest oxidation potentials (Epa) and the highest redox potentials ∆E) in the cyclic voltammetric and potentiometric studies, respectively. In addition, it was observed that the greater the number of hydroxyls linked to the aromatic ring, the greater was the antioxidant activity of the analysed compounds. The correlations of Spermann – used to compare the methods between themselves and the methods with the relationship structure–antioxidant activity – were r = -0.9762 for th...

Phytochemical and antioedematogenic studies of commercial copaiba oils available in Brazil.

Abstract: The composition of eight samples of commercial copaiba oils, used in the Amazonian region as antiinflammatory agents and available in popular markets, were analysed by gas chromatography/mass spectrometry (HRGC-MS). Major differences were observed in their chemical composition and some adulterations were pointed out. When tested in vivo oils 1 and 3, and to a lesser extent oil 6, significantly inhibited bradykinin-induced oedema formation. The other tested oils had no effect. When assessed in carrageenan-induced oedema formation, oils 1, 2 and 6, but not oil 3, significantly attenuated the oedema formation. The other tested oils failed to affect carrageenan-induced paw oedema. Oils 1 and 6 were further fractionated and several sesquiterpenes and diterpenes were detected. It is suggested that the naturally occurring sesquiterpenes present in the copaiba oils seem to be responsible for the antiinflammatory action reported in the folk medicine. Furthermore, our results clearly show an adulteration in copaiba oils available in Brazil.

Reflexões para a implementação do movimento CTS no contexto educacional brasileiro

Abstract: Neste artigo, situamos, inicialmente, o surgimento historico do movimento ciencia, tecnologia e sociedade (CTS). Por se tratar de um movimento que emerge em contextos bastante distintos do nosso, num segundo momento discutimos aspectos a serem considerados na configuracao de seus objetivos no contexto educacional brasileiro, apontando limitacoes e desafios que se colocam. Destacamos a nossa inexperiencia democratica, relacionada com a trajetoria historica do pais, como um dos obstaculos/desafios para colocar a tomada de decisoes, em relacao a ciencia e a tecnologia, numa perspectiva mais democratica (mais atores sociais participando) e menos tecnocratica, aspecto central do CTS.

Ultraviolet Line Spectra of Metal-poor Star-forming Galaxies

Abstract: We present synthetic ultraviolet spectra of metal-poor star-forming galaxies that were calculated with the Starburst99 package. A new spectral library was generated from Hubble Space Telescope observations of O stars in the Large and Small Magellanic Clouds. The corresponding mean metallicity of the synthetic spectra is approximately The spectra have a resolution of 1 and cover the spectral 1 Z _ .A e range 1200¨1600 A set of model spectra was calculated for a standard initial mass function and star Ae . formation history and is compared to synthetic spectra at solar metallicity. We —nd that the spectral lines are generally weaker at lower metallicity, as expected from the lower elemental abundances. Stellar wind lines, however, show a more complex behavior: the metallicity dependence of the ionization balance can be important in trace ions, like N4‘ and Si3‘. Therefore, the strength of N V j1240 and Si IV j1400 does not scale monotonically with metallicity. We compare our new models to ultraviolet spectra of NGC 5253 and MS 1512-cB58, two star-forming galaxies with one-fourth solar metallicity at low and high redshifts, respectively. The new library provides signi—cantly better —ts to the observations than earlier models using the library. We discuss the potential of utilizing stellar photospheric and Z _ wind lines to estimate the chemical composition of star-forming galaxies. The new metal-poor synthetic spectra are available via the Starburst99 Web site.

Extraction of lemongrass essential oil with dense carbon dioxide

Abstract: Lemongrass (Cymbopogon citratus) essential oil was extracted with dense carbon dioxide at 23–50 °C and 85–120 bar. The composition of samples collected during the first and the last hours of the extraction experiments was analyzed by gas chromatography–mass spectrometry, and coextraction of cuticular waxes was observed. Liquid carbon dioxide extracts had a larger quantity of coextracted waxes than the supercritical extracts. The process condition of 120 bar and 40 °C was considered ideal for the extraction of lemongrass essential oil, as a good-quality product was obtained together with a good extraction rate and yield.

Fatores de risco para o desenvolvimento de distúrbios alimentares: um estudo em universitárias

Abstract: This work studied a group of 221 college women, to identify those who presented risk factors compatible with the development of eating disorders. The Eating Attitudes Test was applied to 221 women (114 nutrition students and 107 students from other areas, unrelated to the health field). Results indicated that 22.17% of the group presented risk factors in the development of an eating disorder. Nutrition students presented a higher percentage (25.43%) than the other students (18.69%), but this difference was not significant. However, women who study nutrition may be exposed to an environment more propitious to the development of eating disorders.

Myeloperoxidase and adenosine-deaminase levels in the pleural fluid leakage induced by carrageenan in the mouse model of pleurisy.

Abstract: Background: Although myeloperoxidase (MPO) and adenosine-deaminase (ADA) levels are markers of activated leukocytes, both enzymes have not been currently addressed in inflammation models. Aims: This study evaluates whether the concentrations of these enzymes are significantly correlated with the content of leukocytes in a pleurisy model. Methods: The pleurisy was induced by carrageenan (1%) in mice, and the parameters analyzed 4 and 48 h after. Results: After the induction of inflammation (4 h), MPO and ADA levels peaked in parallel to neutrophils (p < 0.01). Regarding the second phase of pleurisy (48 h), the highest concentrations of ADA were detected in parallel to the highest levels of mononuclears (p < 0.01). At this time, MPO levels and neutrophils remained elevated, although at lower levels than those found at 4 h. A significant positive correlation was found among neutrophils and MPO, and mononuclears and ADA (p < 0.01). Conclusions: These findings support the evidence that both enzymes are markers of the inflammatory process, and provide new tools for a better understanding of the immunoregulatory pathways that occur in inflammation.

Crescimento inicial de Euterpe edulis Mart. em diferentes regimes de luz

Abstract: Plantas sob forte sombreamento (2% ou 6% da luz solar direta) apresentaram, em relacao as plantas sob maior nivel de luz, menor biomassa, menores taxas de crescimento, menor razao raiz/parte aerea, menor massa foliar especifica (MFE), menor razao clorofila a/b e maior razao de area foliar (RAF). Com o aumento da irradiância as plantas apresentaram tres tipos de comportamento, dependendo da quantidade de luz dada: 1) ate cerca de 20% da luz solar direta as plantas apresentaram, com aumento da luz, aumento de biomassa, das taxas de crescimento relativo (TCR) e de assimilacao liquida (TAL), maior alocacao de biomassa para a raiz, maior numero de folhas, maior MFE, maior razao clorofila a/b e menor razao de peso foliar (RPF) e RAF; 2) entre 20% e 70% de luz as plantas nao mostraram alteracoes morfologicas ou fisiologicas com aumento na quantidade de luz, a excecao de um aumento na razao clorofila a/b; e 3) plantas crescendo em luz solar plena apresentaram uma reducao do crescimento em massa seca. As plantas transferidas de 4% para 20 ou 30% de luz mostraram respostas similares aquelas das plantas crescidas sempre em mais luz. A densidade de estomatos mostrou uma leve tendencia ao aumento em plantas transferidas para maior quantidade de luz. O menor crescimento em niveis mais fortes de sombreamento e o maior crescimento com aumento de irradiância ate 20-30% da luz solar total sugere que a especie possa se beneficiar do aparecimento de clareiras para sua regeneracao. O menor desempenho das plantas em condicoes de luz plena ou forte sombreamento sugere menor capacidade competitiva da especie em grandes clareiras ou sob dossel fechado.

Ensino-aprendizagem: uma interação entre dois processos comportamentais

Abstract: The learning-teaching process is a name that is given to a complex system of behavioural interactions between teachers and pupils. Apart from just “teaching” and “learning”, as if these were processes independent of human activities, there are also behavioural processes that are referred to as “teaching” and “learning”. They are processes c omprised of behaviours that are complex and difficult to perceive, principally due to their being comprised of multiple interacting components. The very behaviours themselves are subject to perception and scientific definition based on the identification of their components and the interactions they establish between themselves and which are given the names of “teaching” and “learning”. The interdependence of the two concepts is fundamental in order to understand what happens under each of these names. The perception and understanding of them is crucial for the development of any learning, education or teaching activity. How can these components be identified? How can the relationships between them be characterised? How can the “teaching-learning” process be seen? This article presents an examination of this process, in the light of the concepts arising from the Analysis of Behaviour, locating its possible contributions to the development of Education in relation to experiences of great value which originated and have been developed in Brazil, almost unknown to the majority of those that comprise them and to many Who work in Education. Keywords: Scheduled teaching. Teaching-learning. Analysis of the behaviour of “teaching”. Personalised teaching .

Caracterização de cinza de casca de arroz para uso como matéria-prima na fabricação de refratários de sílica

Abstract: The characterization of rice husk ash, a deriving by-product of the burning of the rice husk during the rice processing is the object of this study. This by-product, for being rich in silica, can be an important raw material for the production of siliceous ceramics, such as thermal insulators and refractory. A combination of surface analysis, thermal analysis and microscopy analysis techniques was used for the characterization. The characterized by-product presented as main component the silica, under amorphous form, with a maximum content of alkalis around 1%, features that become it potentially interesting for the production of ceramic materials.