638 research outputs found

    Ionized regions in the central arcsecond of NGC 1068. YJHK spatially resolved spectroscopy

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    Context. Several bright emission line regions have been observed in the central 100 parsecs of the active galaxy NGC 1068. Aims. We aim to determine the properties and ionization mechanism of three regions of NGC 1068: the nucleus (B) and two clouds located at 0.3" and 0.7" north of it (C and D). Methods. We combined SPHERE (0.95 - 1.65 um) and SINFONI (1.5 - 2.45 um) spectra for the three regions B, C, and D. We compared these spectra to several CLOUDY photoionization models and to the MAPPINGS III Library of Fast Radiative Shock Models. Results. The emission line spectra of the three regions are almost identical to each other and contribute to most of the emission line flux in the nuclear region. The emitting media contain multiple phases, the most luminous of which have temperatures ranging from 104.8 K to 106 K. Central photoionization models can reproduce some features of the spectra, but the fast radiative shock model provides the best fit to the data. Conclusions. The similarity between the three regions indicates that they belong to the same class of objects. Based on our comparisons, we conclude that they are shock regions located where the jet of the active galactic nucleus impacts massive molecular clouds.Comment: A&A, Forthcoming article, accepted for publicatio

    Self-Consistent Pushing and Cranking Corrections to the Meson Fields of the Chiral Quark-Loop Soliton

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    We study translational and spin-isospin symmetry restoration for the two-flavor chiral quark-loop soliton. Instead of a static soliton at rest we consider a boosted and rotating hedgehog soliton. Corrected classical meson fields are obtained by minimizing a corrected energy functional which has been derived by semi-classical methods ('variation after projection'). We evaluate corrected meson fields in the region 300 MeV \le M \le 600 MeV of constituent quark masses M and compare them with the uncorrected fields. We study the effect of the corrections on various expectation values of nuclear observables such as the root-mean square radius, the axial-vector coupling constant, magnetic moments and the delta-nucleon mass splitting.Comment: 19 pages, LaTeX, 7 postscript figures included using 'psfig.sty', to appear in Int.J.Mod.Phys.

    A 3D model for the stellar populations in the nuclei of NGC 1433,NGC 1566, and NGC 1808

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    Aims. We aim to characterize the properties of the stellar populations in the central few hundred parsecs of nearby galactic nuclei; specifically their age, mass, and 3D geometry. Methods. We use spatially resolved spectroscopic observations of NGC 1433, NGC 1566, and NGC 1808 obtained with SINFONI to constrain a 3D model composed of a spherically symmetric nuclear star cluster (NSC) and an extended thick stellar disk. We computed UV to mid-infrared single stellar population (UMISSP) spectra to determine the age of the stellar populations and construct synthetic observations for our model. To overcome degeneracies between key parameters, we simultaneously fit the spatially resolved line-of-sight velocity, line-of-sight-velocity-dispersion, low-spectral-resolution NIR continuum, and high-spectral-resolution CO absorption features for each pixel. Results. For the three objects, we derive the age and mass of the young and old stellar populations in the NSC and surrounding disk, as well as their 3D geometry: radius for the NSC; thickness, inclination, and position angle for the disk. These results are consistent with published independent measurements when available. Conclusions. The proposed method allows us to derive a consistent 3D model of the stellar populations in nearby galactic centers solely based on a near-infrared IFU observation

    Annual Report 2005 - Institute of Nuclear and Hadron Physics

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    Preface The Forschungszentrum Rossendorf (FZR) at Dresden is a multidisciplinary research center within the Wissenschafts-Gemeinschaft G. W. Leibniz (WGL), one of the German agencies for extra-university research. The center is active in investigations on the structure of matter as well as in the life sciences and in environmental research. The Institute of Nuclear and Hadron Physics (IKH) within the FZR avails for its research the coupling of radiation to matter in subatomic dimensions as well as to tissue, to cells, and to their components. Its research in the field of Subatomic Physics is part of the FZR-program Structure of Matter and its investigations concerning the interaction of Biostructures and Radiation contribute to the bf Life Science program of the FZR. In this field the IKH exploits possibilities for transfer and introduction of experimental and theoretical techniques from particle and nuclear physics to projects in radiobiology and biophysics. Much of this kind of interdisciplinary transfer is connected to the Radiation Source ELBE at the FZR. With its superconducting accelerator for relativistic electrons this large installation provides photons in the wide wavelength range from fm to mm - i.e. bremsstrahlung for the investigation of photonuclear processes, hard X-rays for radiobiological and other studies and infrared light for research on the structural dynamics of biomolecules. The investigation of radiation-induced processes not only dominates the projects in nuclear astrophysics as pursued at ELBE, it also is a central theme of the experimental and theoretical research performed by the IKH in close connection to the heavy ion synchrotron SIS and the upcoming FAIR facility at Darmstadt. ELBE also will deliver compact bunches of secondary neutrons and fission fragments; both offer new possibilities in laboratory studies related to the cosmic breeding of the chemical elements thus complementing the astrophysics-motivated studies with bremsstrahlung photons..

    X-ray scattering from warm dense iron

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    We have carried out X-ray scattering experiments on iron foil samples that have been compressed and heated using laser-driven shocks created with the VULCAN laser system at the Rutherford-Appleton Laboratory. This is the highest Z element studied in such experiments so far and the first time scattering from warm dense iron has been reported. Because of the importance of iron in telluric planets, the work is relevant to studies of warm dense matter in planetary interiors. We report scattering results as well as shock breakout results that, in conjunction with hydrodynamic simulations, suggest the target has been compressed to a molten state at several 100 GPa pressure. Initial comparison with modelling suggests more work is needed to understand the structure factor of warm dense iron

    Saúde bucal, práticas de higiene bucal e ocorrência de câncer da cavidade oral

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    OBJECTIVE: To assess the association between oral health and hygiene practices and oral cancer. METHODS: Hospital-based case-control study in the metropolitan area of São Paulo, southeastern Brazil, from 1998 to 2002. A total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. Cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. Detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. Odds ratios (OR) and 95% confidence intervals (95% CI), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. RESULTS: The use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (OR 3.1; 95% CI 1.2-7.9). Those who never attended a dental visit were more likely to have oral cancer (OR 2.5; 95% CI 1.3-4.8). Daily mouthwash use showed a stronger association to pharynx (OR 4.7; 95% CI 1.8-12.5) than mouth cancer (OR 3.2; 95% CI 1.6-6.3). CONCLUSIONS: Gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.OBJETIVO: Avaliar a associação entre saúde e higiene bucal na ocorrência de câncer oral. MÉTODOS: Estudo caso-controle de base hospitalar, realizado entre 1998 e 2002 na área metropolitana de São Paulo, SP. Foram incluídos 309 pacientes com carcinoma epidermóide de boca e orofaringe e 468 controles, pareados com os casos por sexo e idade. Os casos foram levantados em sete hospitais que concentram a assistência médica a pacientes com a doença e os controles rastreados em cinco hospitais gerais dentre os sete. Informações pormenorizadas sobre tabagismo, consumo de álcool, escolaridade, saúde bucal e práticas de higiene bucal foram obtidas por entrevista. Por meio de análise de regressão logística não condicional foram calculados odds ratios (OR) e intervalos com 95% de confiança (IC 95%), ajustados por sexo, idade, nível educacional, tabagismo e consumo de álcool, bem como para as demais variáveis de saúde e higiene bucal. RESULTADOS: Uso de prótese bucal total não se associou a câncer oral, mas sangramento gengival freqüente apresentou alta associação (OR=3,1; IC 95%: 1,2;7,9). Nunca ter consultado dentista mostrou associação com câncer oral (OR=2,5; IC 95%: 1,3;4,8). Uso diário de enxaguatórios bucais apresentou associação mais intensa com tumores de faringe (OR=4,7; IC 95%: 1,8;12,5) do que com tumores de boca (OR=3,2; IC 95%: 1,6;6,3). CONCLUSÕES: Sangramento gengival, ausência de consultas com dentistas e uso regular de enxaguatórios bucais foram fatores associados com câncer oral, independentemente de tabagismo e consumo de bebidas alcoólicas.European Commission ContractFundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP

    Oral health, hygiene practices and oral cancer

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    OBJECTIVE: To assess the association between oral health and hygiene practices and oral cancer. METHODS: Hospital-based case-control study in the metropolitan area of São Paulo, southeastern Brazil, from 1998 to 2002. A total 309 patients with squamous cell carcinoma of the mouth and the pharynx and 468 controls matched by sex and age were included in the study. Cases were recruited in seven reference hospitals and controls were selected in five out of the seven participating hospitals. Detailed information on smoking, alcohol consumption, schooling, oral health status and hygiene practices were obtained through interviews. Odds ratios (OR) and 95% confidence intervals (95% CI), adjusted by sex, age, schooling, smoking, alcohol consumption as well as the variables oral health status and hygiene practices were estimated using unconditional logistic regression analyses. RESULTS: The use of complete dental prosthesis was not associated with oral cancer but regular gum bleeding showed a strong association (OR 3.1; 95% CI 1.2-7.9). Those who never attended a dental visit were more likely to have oral cancer (OR 2.5; 95% CI 1.3-4.8). Daily mouthwash use showed a stronger association to pharynx (OR 4.7; 95% CI 1.8-12.5) than mouth cancer (OR 3.2; 95% CI 1.6-6.3). CONCLUSIONS: Gum bleeding, no dental care, and daily mouthwash use were factors associated with oral cancer regardless of tobacco and alcohol consumption.OBJETIVO: Avaliar a associação entre saúde e higiene bucal na ocorrência de câncer oral. MÉTODOS: Estudo caso-controle de base hospitalar, realizado entre 1998 e 2002 na área metropolitana de São Paulo, SP. Foram incluídos 309 pacientes com carcinoma epidermóide de boca e orofaringe e 468 controles, pareados com os casos por sexo e idade. Os casos foram levantados em sete hospitais que concentram a assistência médica a pacientes com a doença e os controles rastreados em cinco hospitais gerais dentre os sete. Informações pormenorizadas sobre tabagismo, consumo de álcool, escolaridade, saúde bucal e práticas de higiene bucal foram obtidas por entrevista. Por meio de análise de regressão logística não condicional foram calculados odds ratios (OR) e intervalos com 95% de confiança (IC 95%), ajustados por sexo, idade, nível educacional, tabagismo e consumo de álcool, bem como para as demais variáveis de saúde e higiene bucal. RESULTADOS: Uso de prótese bucal total não se associou a câncer oral, mas sangramento gengival freqüente apresentou alta associação (OR=3,1; IC 95%: 1,2;7,9). Nunca ter consultado dentista mostrou associação com câncer oral (OR=2,5; IC 95%: 1,3;4,8). Uso diário de enxaguatórios bucais apresentou associação mais intensa com tumores de faringe (OR=4,7; IC 95%: 1,8;12,5) do que com tumores de boca (OR=3,2; IC 95%: 1,6;6,3). CONCLUSÕES: Sangramento gengival, ausência de consultas com dentistas e uso regular de enxaguatórios bucais foram fatores associados com câncer oral, independentemente de tabagismo e consumo de bebidas alcoólicas
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