989 resultados para zero(th)-order gap
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Universidade Estadual de Campinas . Faculdade de Educação Física
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Os efeitos da concentração de ágar no crescimento de explantes e na formação de calos foram avaliados em culturas axênicas de gametófitos femininos de morfos de coloração verde e vermelha de Gracilaria domingensis (Kützing) Sonder ex Dickie. Culturas unialgáceas foram mantidas em água do mar esterilizada (30-32 ups) enriquecida com 25% da solução de von Stosch (VSES 25%), 22 ± 2 °C, fotoperíodo de 14 h, irradiância de 50-80 µmol de fótons m-2 s-1. Para a obtenção de explantes axênicos, segmentos apicais e intercalares dos dois morfos foram cultivados por 48 h em meio VSES 25% com adição de uma solução antibiótica e antifúngica, e submetidos a uma lavagem com uma solução de água do mar esterilizada com 0,5% de hipoclorito de sódio e 200 µL L-1 de detergente por 20 segundos. Para avaliar os efeitos da concentração de ágar, os segmentos axênicos foram inoculados em meio ASP 12-NTA com concentrações distintas de ágar que variaram de zero a 1%. A adição de ágar no meio inibiu o crescimento dos segmentos apicais de ambos os morfos, bem como o crescimento de segmentos intercalares do morfo verde. Observou-se uma tendência geral no crescimento dos explantes, onde a taxa de crescimento foi inversamente proporcional à concentração de ágar. A adição de ágar no meio induziu a formação de três tipos de calo, denominados conforme a região do explante onde se originaram: calo apical, calo basal e calo intermediário. As concentrações de 0,5% e 0,7% de ágar foram as concentrações ótimas para indução de calos basais e calos intermediários no morfo verde, respectivamente. A presença de ágar foi essencial para a formação de calos intermediários e apicais. Os resultados indicam que o ágar apresenta um papel na regulação dos processos morfogenéticos em morfos pigmentares de G. domingensis.
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Este artigo trata da formação de grupo de suporte no marco das políticas de diversidade empresarial. São escassas as pesquisas que abordem essa prática de gestão da diversidade. Visando a contribuir para o preenchimento dessa lacuna, o trabalho analisa um Comitê de Mulheres, a fim de compreender de que forma ele é influenciado pela política de diversidade formatada pela direção da organização e a influencia. Foi realizado um estudo de caso etnográfico em uma corporação transnacional cuja sede no Brasil está localizada em São Paulo. Os resultados apontam para um paradoxo. Por um lado, o Comitê analisado representa um processo de emancipação, sinalizando para práticas gerenciais mais inclusivas e participativas. Por outro, notou-se a presença de mecanismos de controle, uma vez que há um esforço da direção da empresa em disciplinar o seu funcionamento.
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Objetivo: identificar as representações sociais de mães de crianças da faixa etária de zero a cinco anos de idade do Núcleo de Saúde da Família IV, em Ribeirão Preto-SP, procurando saber o que pensam sobre saúde bucal e tratamento odontológico. Método: trata-se de pesquisa qualitativa, sendo utilizada a entrevista semi-estruturada para a coleta dos dados e a análise de conteúdo. Resultados: constatou-se grande dificuldade das mães em se expressar a respeito do que é, para elas, saúde. Para essas mães a saúde bucal está relacionada com normas de higiene e dietéticas e também com a ida ao dentista, restringindo-se na preocupação com a estética e pouco com a função. Já em relação ao tratamento odontológico, a grande maioria demonstrou apresentar medo, causado pela sua experiência anterior com o tratamento. A assistência particular está associada à pontualidade e ao atendimento da maneira desejada enquanto o tratamento oferecido pelo setor público à demora e à falta de equipamentos e materiais. A humanização no atendimento e competência do profissional emergiram como dois aspectos importantes, e podem estar determinando a decisão de ir ou não ao dentista. Conclusões: A expressão saúde bucal foi associada à assistência odontológica. O atendimento pelo setor privado foi referido como o que mais se aproxima do tipo ideal de assistência odontológica
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This paper revisits the design of L and S band bridged loop-gap resonators (BLGRs) for electron paramagnetic resonance applications. A novel configuration is described and extensively characterized for resonance frequency and quality factor as a function of the geometrical parameters of the device. The obtained experimental results indicate higher values of the quality factor (Q) than previously reported in the literature, and the experimental analysis data should provide useful guidelines for BLGR design.
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We report measurements of the nonlinear (NL) refractive index n(2) of lead-germanium films (LGFs) containing Cu and Cu(2)O nanoparticles (NPs). The thermally managed eclipse Z-scan technique with 150 fs pulses from a laser operating at 800 nm was used. The NL refractive index measured, n(2)=6.3x10(-12) cm(2)/W has electronic origin and the NL absorption coefficient alpha(2) is smaller than 660 cm/GW. The figure of merit n(2)/lambda alpha(2) is enhanced by more than two orders of magnitude in comparison with the result for the LGFs without the copper based NPs. (C) 2008 American Institute of Physics.
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We present STAR results on the elliptic flow upsilon(2) Of charged hadrons, strange and multistrange particles from,root s(NN) = 200 GeV Au+Au collisions at the BNL Relativistic Heavy Ion Collider (RHIC). The detailed study of the centrality dependence of upsilon(2) over a broad transverse momentum range is presented. Comparisons of different analysis methods are made in order to estimate systematic uncertainties. To discuss the nonflow effect, we have performed the first analysis Of upsilon(2) with the Lee-Yang zero method for K(S)(0) and A. In the relatively low PT region, P(T) <= 2 GeV/c, a scaling with m(T) - m is observed for identified hadrons in each centrality bin studied. However, we do not observe nu 2(p(T))) scaled by the participant eccentricity to be independent of centrality. At higher PT, 2 1 <= PT <= 6 GeV/c, V2 scales with quark number for all hadrons studied. For the multistrange hadron Omega, which does not suffer appreciable hadronic interactions, the values of upsilon(2) are consistent with both m(T) - m scaling at low p(T) and number-of-quark scaling at intermediate p(T). As a function ofcollision centrality, an increase of p(T)-integrated upsilon(2) scaled by the participant eccentricity has been observed, indicating a stronger collective flow in more central Au+Au collisions.
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Background: Medical education and training can contribute to the development of depressive symptoms that might lead to possible academic and professional consequences. We aimed to investigate the characteristics of depressive symptoms among 481 medical students (79.8% of the total who matriculated). Methods: The Beck Depression Inventory (BDI) and cluster analyses were used in order to better describe the characteristics of depressive symptoms. Medical education and training in Brazil is divided into basic (1(st) and 2(nd) years), intermediate (3(rd) and 4(th) years), and internship (5(th) and 6(th) years) periods. The study organized each item from the BDI into the following three clusters: affective, cognitive, and somatic. Statistical analyses were performed using analysis of variance (ANOVA) with post-hoc Tukey corrected for multiple comparisons. Results: There were 184 (38.2%) students with depressive symptoms (BDI > 9). The internship period resulted in the highest BDI scores in comparison to both the basic (p < .001) and intermediate (p < .001) periods. Affective, cognitive, and somatic clusters were significantly higher in the internship period. An exploratory analysis of possible risk factors showed that females (p = .020) not having a parent who practiced medicine (p = .016), and the internship period (p = .001) were factors for the development of depressive symptoms. Conclusion: There is a high prevalence towards depressive symptoms among medical students, particularly females, in the internship level, mainly involving the somatic and affective clusters, and not having a parent who practiced medicine. The active assessment of these students in evaluating their depressive symptoms is important in order to prevent the development of co-morbidities and suicide risk.
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Aims. In an earlier paper we introduced a new method for determining asteroid families where families were identified in the proper frequency domain (n, g, g + s) ( where n is the mean-motion, and g and s are the secular frequencies of the longitude of pericenter and nodes, respectively), rather than in the proper element domain (a, e, sin(i)) (semi-major axis, eccentricity, and inclination). Here we improve our techniques for reliably identifying members of families that interact with nonlinear secular resonances of argument other than g or g + s and for asteroids near or in mean-motion resonant configurations. Methods. We introduce several new distance metrics in the frequency space optimal for determining the diffusion in secular resonances of argument 2g - s, 3g - s, g - s, s, and 2s. We also regularize the dependence of the g frequency as a function of the n frequency (Vesta family) or of the eccentricity e (Hansa family). Results. Our new approaches allow us to recognize as family members objects that were lost with previous methods, while keeping the advantages of the Carruba & Michtchenko (2007, A& A, 475, 1145) approach. More important, an analysis in the frequency domain permits a deeper understanding of the dynamical evolution of asteroid families not always obtainable with an analysis in the proper element domain.
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Context. Fossil systems are defined to be X- ray bright galaxy groups ( or clusters) with a two- magnitude difference between their two brightest galaxies within half the projected virial radius, and represent an interesting extreme of the population of galaxy agglomerations. However, the physical conditions and processes leading to their formation are still poorly constrained. Aims. We compare the outskirts of fossil systems with that of normal groups to understand whether environmental conditions play a significant role in their formation. We study the groups of galaxies in both, numerical simulations and observations. Methods. We use a variety of statistical tools including the spatial cross- correlation function and the local density parameter Delta(5) to probe differences in the density and structure of the environments of "" normal"" and "" fossil"" systems in the Millennium simulation. Results. We find that the number density of galaxies surrounding fossil systems evolves from greater than that observed around normal systems at z = 0.69, to lower than the normal systems by z = 0. Both fossil and normal systems exhibit an increment in their otherwise radially declining local density measure (Delta(5)) at distances of order 2.5 r(vir) from the system centre. We show that this increment is more noticeable for fossil systems than normal systems and demonstrate that this difference is linked to the earlier formation epoch of fossil groups. Despite the importance of the assembly time, we show that the environment is different for fossil and non- fossil systems with similar masses and formation times along their evolution. We also confirm that the physical characteristics identified in the Millennium simulation can also be detected in SDSS observations. Conclusions. Our results confirm the commonly held belief that fossil systems assembled earlier than normal systems but also show that the surroundings of fossil groups could be responsible for the formation of their large magnitude gap.
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Context. About 2/3 of the Be stars present the so-called V/R variations, a phenomenon characterized by the quasi-cyclic variation in the ratio between the violet and red emission peaks of the HI emission lines. These variations are generally explained by global oscillations in the circumstellar disk forming a one-armed spiral density pattern that precesses around the star with a period of a few years. Aims. This paper presents self-consistent models of polarimetric, photometric, spectrophotometric, and interferometric observations of the classical Be star zeta Tauri. The primary goal is to conduct a critical quantitative test of the global oscillation scenario. Methods. Detailed three-dimensional, NLTE radiative transfer calculations were carried out using the radiative transfer code HDUST. The most up-to-date research on Be stars was used as input for the code in order to include a physically realistic description for the central star and the circumstellar disk. The model adopts a rotationally deformed, gravity darkened central star, surrounded by a disk whose unperturbed state is given by a steady-state viscous decretion disk model. It is further assumed that this disk is in vertical hydrostatic equilibrium. Results. By adopting a viscous decretion disk model for zeta Tauri and a rigorous solution of the radiative transfer, a very good fit of the time-average properties of the disk was obtained. This provides strong theoretical evidence that the viscous decretion disk model is the mechanism responsible for disk formation. The global oscillation model successfully fitted spatially resolved VLTI/AMBER observations and the temporal V/R variations in the H alpha and Br gamma lines. This result convincingly demonstrates that the oscillation pattern in the disk is a one-armed spiral. Possible model shortcomings, as well as suggestions for future improvements, are also discussed.