1,452 research outputs found

    Discovery of very high energy gamma-ray emission in the W 28 (G6.4-0.1) region, and multiwavelength comparisons

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    H.E.S.S. observations of the old-age (>10^4yr; ~0.5deg diameter) composite supernova remnant (SNR) W 28 reveal very high energy (VHE) gamma-ray emission situated at its northeastern and southern boundaries. The northeastern VHE source (HESS J1801-233) is in an area where W 28 is interacting with a dense molecular cloud, containing OH masers, local radio and X-ray peaks. The southern VHE sources (HESS J1800-240 with components labelled A, B and C) are found in a region occupied by several HII regions, including the ultracompact HII region W 28A2. Our analysis of NANTEN CO data reveals a dense molecular cloud enveloping this southern region, and our reanalysis of EGRET data reveals MeV/GeV emission centred on HESS J1801-233 and the northeastern interaction region.Comment: 4 pages, 3 figures, proceedings of the 30th ICRC, Merida, Mexico, 200

    Fisiopatologia e aspectos inflamatórios da aterosclerose = Physiopathology and inflammatory aspects of atherosclerosis

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    Objetivo: Apresentar e avaliar o que tem se descoberto recentemente sobre a fisiopatologia, epidemiologia e aspectos inflamatórios envolvidos na aterosclerose dentro de uma perspectiva multidisciplinar Fonte de dados: Foram realizadas compilações bibliográficas sobre artigos científicos originais e de revisão em revistas indexadas no MEDLINE no período de 1970 ao atual que envolvesse assuntos relacionados à aterosclerose. Conclusão: O entendimento da biologia básica da inflamação na aterosclerose proporcionaria um melhor suporte clínico que poderia alterar o caminho da prática da medicina preventiva e propiciar benefícios para a saúde pública Síntese de dados: A revisão sugere que a aterosclerose é uma doença multifatorial com forte componente genético, ambiental e de resposta inflamatória, associada ao envelhecimento. No entanto, ainda a sua etiologia não está completamente esclarecida Conclusão: O entendimento da biologia básica da inflamação na aterosclerose proporcionaria um melhor suporte clínico que poderia alterar o caminho da prática da medicina preventiva e propiciar benefícios para a saúde públic

    Chandra Observations of A Galactic Supernova Remnant Vela Jr.: A New Sample of Thin Filaments Emitting Synchrotron X-Rays

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    A galactic supernova remnant (SNR) Vela Jr. (RX J0852.0-4622, G266.6-1.2) shows sharp filamentary structure on the north-western edge of the remnant in the hard X-ray band. The filaments are so smooth and located on the most outer side of the remnant. We measured the averaged scale width of the filaments (wuw_u and wdw_d) with excellent spatial resolution of {\it Chandra}, which are in the order of the size of the point spread function of {\it Chandra} on the upstream side and 49.5 (36.0--88.8) arcsec on the downstream side, respectively. The spectra of the filaments are very hard and have no line-like structure, and were well reproduced with an absorbed power-law model with Γ=\Gamma = 2.67 (2.55--2.77), or a {\tt SRCUT} model with νrolloff\nu_{rolloff} = 4.3 (3.4--5.3)×1016\times 10^{16} Hz under the assumption of p=0.3p=0.3. These results imply that the hard X-rays are synchrotron radiation emitted by accelerated electrons, as mentioned previously. Using a correlation between a function Bνrolloff/wd2{\cal B} \equiv \nu_{rolloff}/w_d^2 and the SNR age, we estimated the distance and the age of Vela Jr.: the estimated distance and age are 0.33 (0.26--0.50) kpc and 660 (420--1400) years, respectively. These results are consistent with previous reports, implying that B{\cal B}--age relation may be a useful tool to estimate the distance and the age of synchrotron X-ray emitting SNRs.Comment: 19 pages, 8 figures, ApJ, in pres

    CO J=1-0 observations of molecular gas interacting with galactic supernova remnants G5.4-1.2, G5.55+0.32 and G5.71-0.08

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    The field just West of the galactic supernova remnant W28 (l=6.4\degr, b=-0.2\degr) harbors 3 of 5 newly-discovered 1720 OH maser spots and two recently-discovered candidate supernova candidates (one of which is a γ\gamma-ray source), as well as several compact and classical HII regions. Here, we analyze a datacube of CO J=1-0 emission having 1\arcmin and 1 \kms resolution, made with on-the-fly mapping over the region 5\degr \le l \le 6\degr, -1\degr \le b \le 0.5\degr}. {Extended and often very bright CO emission was detected at the velocities of the 1720 MHz OH masers and around the supernova remnant G5.55+0.32 which lacks a maser. A new bipolar outflow which is marginally resolved at 1\arcmin resolution and strong in CO (12K) was detected at the periphery of G5.55+0.32, coincident with an MSX source; there is also a bright rim of CO just beyond the periphery of the radio remnant. The OH maser near G5.71-0.08 lies on a shell of strongly-emitting molecular gas (up to 20K) . At the -21 \kms velocity of G5.4-1.2, CO covers much of the field but is weak (3 K) and undisturbed near the remnant. The extended molecular gas around the compact H II region and outflow in G5.89-0.39 (W28A2) is shown for the first time.}Comment: 6 Pages, 3 figures submitted to A&A 4 May 200

    A definição dos idosos de qualidade de vida

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    OBJECTIVES: Senescence for some elderly people is a phase of with development and satisfaction, whereas for others is a negative stage of life. The determinants of a good quality of life in old age vary from person to person. The aims of this study were to identify: 1) the prevalence of octogenarian people who evaluate their current life as being mainly characterized by a positive quality and 2) which were the domains that they identified as being the determinants of this positive quality. A same parallel study was conducted with subjects who evaluated senescence as a preponderantly negative experience. METHODS: A random and representative sample of 35% of the octogenarian people, living residing in the community, was selected among the dwellers of the city of Veranópolis, state of Rio Grande do Sul. A semi-structured questionnaire on quality of life quality was applied as well as the scale of depressive symptoms Geriatric Depression Scale (GDS) and the index of general health Cumulative Illness Rating Scale (CIRS). RESULTS: Slightly more than half of the studied sample (57%) defined their current quality of life with positive evaluations, whereas 18% presented a negative evaluation of it. A group 0f 25% defined their current lives as neutral or having both values (positive and negative). Those who were dissatisfied presented more health problems according to the CIRS and more depressive symptoms when evaluated by the GDS. Satisfied subjects ones had different reasons to justify this state, however, the dissatisfied had mainly the lack of health as a reason for their suffering. The main source of reported daily well-being was the involvement with rural or domestic activities. Among the interviewed, lack of health was the main source for not presenting well-being, although there was interpersonal variability regarding what each subject considered as loss of health. CONCLUSION: Possibly, for the elderly subjects a negative quality of life is equivalent to loss of health and a positive life quality is equivalent to a greater range of categories such as activity, income, social life and relationship with the family, categories which differed from subject to subject. Therefore, health seems to be a good indicator of negative quality of life, though an insufficient indicator of successful elderliness.OBJETIVOS: A velhice para alguns é uma etapa de desenvolvimento e satisfação, enquanto para outros é uma fase negativa da vida. Os determinantes da boa qualidade de vida na velhice variam de sujeito para sujeito. O objetivo do presente estudo foi identificar: 1) a prevalência de octagenários que avaliavam sua vida atual na velhice como preponderantemente de uma qualidade positiva e 2) quais aspectos eles identificavam como os determinantes desta qualidade positiva. Igual estudo em paralelo foi feito com sujeitos que avaliavam a velhice como uma experiência preponderantemente negativa. MÉTODOS: Uma amostra randômica e representativa de 35% dos idosos com mais de 80 anos residentes na comunidade foi selecionada entre os residentes em Veranópolis, Rio Grande do Sul. Um questionário semi- estruturado de qualidade de vida foi aplicado, bem como a escala de sintomas depressivos Geriatric Depression Scale (GDS) e o Índice de Saúde Geral Cumulative Illness Rating Scale (CIRS). RESULTADO: Um pouco mais da metade dos idosos estudados (57%) definia sua qualidade de vida atual com avaliações positivas, sendo que 18% tinham uma avaliação negativa da vida atual. Um grupo de 25% definia sua vida atual de forma neutra ou de dois valores (aspectos positivos e aspectos negativos). Comparados com os satisfeitos, os insatisfeitos tinham mais problemas de saúde pela CIRS e mais sintomas depressivos quando avaliados pela GDS. Os satisfeitos tinham diferentes motivos para justificar este estado, porém os insatisfeitos tinham principalmente a falta de saúde física como motivo do sofrimento. A maior fonte de bem estar no dia-a-dia citada era o envolvimento com atividades rurais ou domésticas. Entre os entrevistados, a perda da saúde física era a principal fonte de mal estar, sendo que havia variabilidade interpessoal quanto ao que cada sujeito considerava como perda de saúde. CONCLUSÃO: É possível que para idosos, qualidade negativa de vida seja equivalente a perda de saúde e qualidade de vida positiva seja equivalente a uma pluralidade maior de categorias como atividade, renda, vida social e relação com a família, categorias diferentes de sujeito para sujeito. O aspecto saúde parece assim um bom indicador de qualidade de vida negativa, porém um indicador insuficiente de velhice bem sucedida.Catholic University of the state of Rio Grande do Sul Institute of Geriatrics and Gerontology Geriatric neuropsychiatric ambulatoryWHO PAHO Associated Chronic Degenerating DiseasesFederal University of São Paulo Paulista Medical School Department of PsychiatryPUCRS Medical School Department of PsychiatryUNIFESP, EPM, Department of PsychiatrySciEL

    Electronic structure of periodic curved surfaces -- topological band structure

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    Electronic band structure for electrons bound on periodic minimal surfaces is differential-geometrically formulated and numerically calculated. We focus on minimal surfaces because they are not only mathematically elegant (with the surface characterized completely in terms of "navels") but represent the topology of real systems such as zeolites and negative-curvature fullerene. The band structure turns out to be primarily determined by the topology of the surface, i.e., how the wavefunction interferes on a multiply-connected surface, so that the bands are little affected by the way in which we confine the electrons on the surface (thin-slab limit or zero thickness from the outset). Another curiosity is that different minimal surfaces connected by the Bonnet transformation (such as Schwarz's P- and D-surfaces) possess one-to-one correspondence in their band energies at Brillouin zone boundaries.Comment: 6 pages, 8 figures, eps files will be sent on request to [email protected]

    The multi-band nonthermal emission from the supernova remnant RX J1713.7-3946

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    Nonthermal X-rays and very high-energy (VHE) γ\gamma-rays have been detected from the supernova remnant (SNR) RX J1713.7-3946, and especially the recent observations with the \textit{Suzaku} satellite clearly reveal a spectral cutoff in the X-ray spectrum, which directly relates to the cutoff of the energy spectrum of the parent electrons. However, whether the origin of the VHE γ\gamma-rays from the SNR is hadronic or leptonic is still in debate. We studied the multi-band nonthermal emission from RX J1713.7-3946 based on a semi-analytical approach to the nonlinear shock acceleration process by including the contribution of the accelerated electrons to the nonthermal radiation. The results show that the multi-band observations on RX J1713.7-3946 can be well explained in the model with appropriate parameters and the TeV γ\gamma-rays have hadronic origin, i.e., they are produced via proton-proton (p-p) interactions as the relativistic protons accelerated at the shock collide with the ambient matter.Comment: 6 pages, 5 figures, accepted by MNRA

    Star Forming Dense Cloud Cores in the TeV {\gamma}-ray SNR RX J1713.7-3946

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    RX J1713.7-3946 is one of the TeV {\gamma}-ray supernova remnants (SNRs) emitting synchrotron X rays. The SNR is associated with molecular gas located at ~1 kpc. We made new molecular observations toward the dense cloud cores, peaks A, C and D, in the SNR in the 12CO(J=2-1) and 13CO(J=2-1) transitions at angular resolution of 90". The most intense core in 13CO, peak C, was also mapped in the 12CO(J=4-3) transition at angular resolution of 38". Peak C shows strong signs of active star formation including bipolar outflow and a far-infrared protostellar source and has a steep gradient with a r^{-2.2±\pm0.4} variation in the average density within radius r. Peak C and the other dense cloud cores are rim-brightened in synchrotron X rays, suggesting that the dense cloud cores are embedded within or on the outer boundary of the SNR shell. This confirms the earlier suggestion that the X rays are physically associated with the molecular gas (Fukui et al. 2003). We present a scenario where the densest molecular core, peak C, survived against the blast wave and is now embedded within the SNR. Numerical simulations of the shock-cloud interaction indicate that a dense clump can indeed survive shock erosion, since shock propagation speed is stalled in the dense clump. Additionally, the shock-cloud interaction induces turbulence and magnetic field amplification around the dense clump that may facilitate particle acceleration in the lower-density inter-clump space leading to the enhanced synchrotron X rays around dense cores.Comment: 22 pages, 7 figures, to accepted in The Astrophysical Journal. A full color version with higher resolution figures is available at http://www.a.phys.nagoya-u.ac.jp/~sano/ApJ10/ms_sano.pd
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