17 research outputs found

    Evidence of a Quasi-periodic Global-scale Oscillation in the Near-Surface Shear Layer of the Sun

    Full text link
    We present evidence of hitherto undiscovered global-scale oscillations in the near-surface shear layer of the Sun. These oscillations are seen as large scale variations of radial shear in both the zonal and meridional flows relative to their mean values. The variations cover all or most of a visible hemisphere, and reverse with a timescale on the order of a solar rotation. A large annual variation in the meridional shear anomaly is understandable in terms of the tilt of the rotation axis, but the rapid oscillations of the shear anomalies in both zonal and the meridional directions appear to be modulated in a more complex, not-quite annual way, although the latter are also strongly modulated by the projected rotational axis angle. Small-scale anomalies in the neighborhood of active regions lend support to their solar origin and physical interpretation. These results were obtained by analyzing ring-diagram fits of low-order modes in high-resolution Doppler data from the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory.Comment: Accepted for publication in Astrophysical Journal Letter

    Taiwan Oscillation Network

    Get PDF
    The Taiwan Oscillation Network (TON) is a ground-based network to measure solar intensity oscillations to study the internal structure of the Sun. K-line full-disk images of 1000 pixels diameter are taken at a rate of one image per minute. Such data would provide information onp-modes withl as high as 1000. The TON will consist of six identical telescope systems at proper longitudes around the world. Three telescope systems have been installed at Teide Observatory (Tenerife), Huairou Solar Observing Station (near Beijing), and Big Bear Solar Observatory (California). The telescopes at these three sites have been taking data simultaneously since October of 1994. Anl – v diagram derived from 512 images is included to show the quality of the data

    HIV Aspartyl Peptidase Inhibitors Interfere with Cellular Proliferation, Ultrastructure and Macrophage Infection of Leishmania amazonensis

    Get PDF
    Submitted by Sandra Infurna ([email protected]) on 2019-01-08T13:43:09Z No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Approved for entry into archive by Sandra Infurna ([email protected]) on 2019-01-08T13:51:34Z (GMT) No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5)Made available in DSpace on 2019-01-08T13:51:34Z (GMT). No. of bitstreams: 1 Ellenf_Altoe_etal_IOC_2009.pdf: 1452755 bytes, checksum: 77127a59920cef6bca71296107f6ec63 (MD5) Previous issue date: 2009Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Biofísica Carlos Chagas Filho. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Universidade Federal do Rio de Janeiro. Centro de Ciências da Saúde. Instituto de Microbiologia Prof. Paulo de Góes. Departamento de Microbiologia Geral,. Rio de Janeiro, RJ, Brasil.Fundação Oswaldo Cruz. Instituto Oswaldo Cruz. Laboratório de Biologia Molecular e Doenças Endêmicas. Rio de Janeiro, RJ. Brasil.Leishmania is the etiologic agent of leishmanisais, a protozoan disease whose pathogenic events are not well understood. Current therapy is suboptimal due to toxicity of the available therapeutic agents and the emergence of drug resistance. Compounding these problems is the increase in the number of cases of Leishmania-HIV coinfection, due to the overlap between the AIDS epidemic and leishmaniasis

    Probing the subsurface structures of active regions with ring-diagram analysis

    No full text
    We analyze the variations in the near-surface profiles of sound speed and adiabatic constant between active regions and neighboring quiet-Sun areas using the technique of ring-diagram analysis and inversions of the frequency differences between the regions. This approach minimizes the systematic observational effects on the fitted spectral model parameters. The regions analyzed have been selected from a large sample of data available from both GONG and MDI and include a wide range of magnetic activity levels as measured in several respects. We find that the thermal-structure anomalies under active regions have a consistent depth profile, with only the magnitude of the effect varying with the intensity of the active regions. Both the sound speed and the first adiabatic index are depressed near the surface but enhanced at greater depths. The turnover for the sound speed occurs at a shallower depth than that for the adiabatic index. The amplitude of the thermal anomalies at all depths correlates more closely with the total magnetic flux of the active regions than with spot areas or flare activity levels. The depth of the turnover does not appear to depend on the strength of the region

    Evidence of a Quasiperiodic Global-scale Oscillation in the Near-surface Shear Layer of the Sun

    Get PDF
    We present evidence of hitherto undiscovered global-scale oscillations in the near-surface shear layer of the Sun. These oscillations are seen as large-scale variations of radial shear in both the zonal and meridional flows relative to their mean values. The variations cover all or most of a visible hemisphere, and reverse with a timescale on the order of a solar rotation. A large annual variation in the meridional shear anomaly is understandable in terms of the tilt of the rotation axis, but the rapid oscillations of the shear anomalies in both zonal and the meridional directions appear to be modulated in a more complex, not-quite-annual way, although the latter are also strongly modulated by the projected rotational axis angle. Small-scale anomalies in the neighborhood of active regions lend support to their solar origin and physical interpretation. These results were obtained by analyzing ring-diagram fits of low-order modes in high-resolution Doppler data from the Helioseismic and Magnetic Imager on the Solar Dynamics Observatory

    Pregnancy incidence, outcomes and associated factors in a cohort of women living with HIV/AIDS in Rio de Janeiro, Brazil, 1996-2016

    No full text
    Abstract The aim of this research was to analyze pregnancy incidence and associated factors in a cohort of 753 women living with HIV/AIDS (WLWHA) in Rio de Janeiro, Brazil, from 1996 to 2016. Women aged 18-49 years who were not on menopause (surgical or natural) and did not have a tubal ligation were eligible for the study. Data were collected by medical professionals during initial and follow-up visits. Person-time pregnancy incidence rates were calculated throughout the follow-up period. Pregnancy incidence-associated factors were investigated by univariate and multiple analyzes, using an extension of the Cox survival model. Follow-up visits recorded 194 pregnancies, with an incidence rate of 4.01/100 person-years (95% CI: 3.47; 4.60). A higher pregnancy incidence was associated with CD4 nadir ≥ 350 cells/mm³, use of an antiretroviral regimen not containing Efavirenz, and prior teenage pregnancy. In turn, women with a viral load ≥ 50 copies/mL, age ≥ 35 years old, with two or more children and using a highly effective contraceptive method showed a lower incidence. Results showed a significant reduction in pregnancy incidence after 2006, a significant reduction in female sterilization from 1996 to 2016, and a high rate of cesarean sections. The association found between pregnancy incidence and the use of contraceptive methods and virological control markers suggests a good integration between HIV/AIDS and reproductive health services. The high rate of cesarean section delivery indicates the need to improve childbirth care
    corecore