Variations in pp-Mode Parameters with Changing Onset-Time of a Large Flare

It is expected that energetic solar flares releasing large amount of energy at the photosphere may be able to excite the acoustic ($p$-) modes of oscillations. We have determined the characteristic properties of mode parameters by applying the ring diagram technique to 3-D power spectra obtained for solar active region NOAA 10486 during the long duration energetic X17.2/4B flare of October 28, 2003. Strong evidence of substantial increase in mode amplitude and systematic variations in sub-surface flows, i.e., meridional and zonal components of velocity, kinetic helicity, vorticity, is found from comparison of the pre- to the post-flare phases.Comment: 14 pages, 4 figure

Subsurface Flows in and Around Active Regions with Rotating and Non-rotating Sunspots

The temporal variation of the horizontal velocity in subsurface layers beneath three different types of active regions is studied using the technique of ring diagrams. In this study, we select active regions (ARs) 10923, 10930, 10935 from three consecutive Carrington rotations: AR 10930 contains a fast-rotating sunspot in a strong emerging active region while other two have non-rotating sunspots with emerging flux in AR 10923 and decaying flux in AR 10935. The depth range covered is from the surface to about 12 Mm. In order to minimize the influence of systematic effects, the selection of active and quiet regions is made so that these were observed at the same heliographic locations on the solar disk. We find a significant variation in both components of the horizontal velocity in active regions as compared to quiet regions. The magnitude is higher in emerging-flux regions than in the decaying-flux region, in agreement with earlier findings. Further, we clearly see a significant temporal variation in depth profiles of both zonal and meridional flow components in AR 10930, with the variation in the zonal component being more pronounced. We also notice a significant influence of the plasma motion in areas closest to the rotating sunspot in AR 10930 while areas surrounding the non-rotating sunspots in all three cases are least affected by the presence of the active region in their neighborhood.Comment: Solar Physics (in press), includes 11 figure

Solar-cycle variation of the sound-speed asphericity from GONG and MDI data 1995-2000

We study the variation of the frequency splitting coefficients describing the solar asphericity in both GONG and MDI data, and use these data to investigate temporal sound-speed variations as a function of both depth and latitude during the period from 1995-2000 and a little beyond. The temporal variations in even splitting coefficients are found to be correlated to the corresponding component of magnetic flux at the solar surface. We confirm that the sound-speed variations associated with the surface magnetic field are superficial. Temporally averaged results show a significant excess in sound speed around 0.92 solar radii and latitude of 60 degrees.Comment: To be published in MNRAS, accepted July 200

Parametrizing the time-variation of the "surface term" of stellar p-mode frequencies: application to helioseismic data

The solar-cyle variation of acoustic mode frequencies has a frequency dependence related to the inverse mode inertia. The discrepancy between model predictions and measured oscillation frequencies for solar and solar-type stellar acoustic modes includes a significant frequency-dependent term known as the surface term that is also related to the inverse mode inertia. We parametrize both the surface term and the frequency variations for low-degree solar data from Birmingham Solar-Oscillations Network (BiSON) and medium-degree data from the Global Oscillations Network Group (GONG) using the mode inertia together with cubic and inverse frequency terms. We find that for the central frequency of rotationally split multiplets the cubic term dominates both the average surface term and the temporal variation, but for the medium-degree case the inverse term improves the fit to the temporal variation. We also examine the variation of the even-order splitting coefficients for the medium-degree data and find that, as for the central frequency, the latitude-dependent frequency variation, which reflects the changing latitudinal distribution of magnetic activity over the solar cycle, can be described by the combination of a cubic and an inverse function of frequency scaled by inverse mode inertia. The results suggest that this simple parametrization could be used to assess the activity-related frequency variation in solar-like asteroseismic targets.Comment: 13 pages, 11 figures. Accepted by MNRAS 13 October 201

Incorporating bazedoxifene/conjugated estrogens into the current paradigm of menopausal therapy

Many women experience bothersome vasomotor and vaginal symptoms during the menopausal transition. Decreasing levels of estrogens during menopause are also associated with reduced bone density and an increased risk of osteoporosis. Combined estrogen/progestin therapy (hormone therapy) effectively treats menopausal symptoms and prevents bone loss, but has been associated with some safety and tolerability concerns. A novel menopausal therapy is the tissue selective estrogen complex, which pairs a selective estrogen receptor modulator with one or more estrogens. In preclinical studies, the tissue selective estrogen complex partnering bazedoxifene (BZA) with conjugated estrogens (CE) antagonized stimulation of breast and endometrial tissue, reduced vasomotor instability, and preserved bone mass in rat and mouse models. The specific attributes seen with BZA/CE were different from those observed with other selective estrogen receptor modulator/estrogen pairings. BZA/CE has undergone clinical evaluation in the Phase III Selective estrogens, Menopause, And Response to Therapy (SMART) trials in postmenopausal women with an intact uterus. Of the various doses of BZA/CE evaluated, BZA 20 mg/CE 0.45 mg and 0.625 mg were associated with a low incidence of endometrial hyperplasia (<1%) similar to placebo, and showed significant improvements in hot flushes and vulvar/vaginal symptoms and increases in bone mineral density. BZA 20 mg/CE 0.45 mg and 0.625 mg were associated with a low incidence of breast-related adverse events and demonstrated no difference from placebo in age-related changes in mammographic breast density. Both BZA/ CE doses showed a favorable tolerability profile, with no increases in uterine bleeding or breast tenderness, and had positive effects on metabolic parameters and quality of life. BZA/CE may be a promising alternative to hormone therapy for the treatment of menopausal symptoms and prevention of osteoporosis in nonhysterectomized postmenopausal women

The Sun in transition? Persistence of near-surface structural changes through Cycle 24

We examine the frequency shifts in low-degree helioseismic modes from the Birmingham Solar-Oscillations Network (BiSON) covering the period from 1985 - 2016, and compare them with a number of global activity proxies well as a latitudinally-resolved magnetic index. As well as looking at frequency shifts in different frequency bands, we look at a parametrization of the shift as a cubic function of frequency. While the shifts in the medium- and highfrequency bands are very well correlated with all of the activity indices (with the best correlation being with the 10.7 cm radio flux), we confirm earlier findings that there appears to have been a change in the frequency response to activity during solar cycle 23, and the low frequency shifts are less correlated with activity in the last two cycles than they were in Cycle 22. At the same time, the more recent cycles show a slight increase in their sensitivity to activity levels at medium and higher frequencies, perhaps because a greater proportion of activity is composed of weaker or more ephemeral regions. This lends weight to the speculation that a fundamental change in the nature of the solar dynamo may be in progress.Comment: 9 pages, 6 figures. Accepted by MNRAS 24 May 201

Observation and Modeling of the Solar-Cycle Variation of the Meridional Flow

We present independent observations of the solar-cycle variation of flows near the solar surface and at a depth of about 60 Mm, in the latitude range $\pm45^\circ$. We show that the time-varying components of the meridional flow at these two depths have opposite sign, while the time-varying components of the zonal flow are in phase. This is in agreement with previous results. We then investigate whether the observations are consistent with a theoretical model of solar-cycle dependent meridional circulation based on a flux-transport dynamo combined with a geostrophic flow caused by increased radiative loss in the active region belt (the only existing quantitative model). We find that the model and the data are in qualitative agreement, although the amplitude of the solar-cycle variation of the meridional flow at 60 Mm is underestimated by the model.Comment: To be published in Solar Physcis Topical Issue "Helioseismology, Asteroseismology, and MHD Connections

Expanding the Entamoeba Universe: New Hosts Yield Novel Ribosomal Lineages.

Removing the requirement for cell culture has led to a substantial increase in the number of lineages of Entamoeba recognized as distinct. Surveying the range of potential host species for this parasite genus has barely been started and it is clear that additional sampling of the same host in different locations often identifies additional diversity. In this study, using small subunit ribosomal RNA gene sequencing, we identify four new lineages of Entamoeba, including the first report of Entamoeba from an elephant, and extend the host range of some previously described lineages. In addition, examination of microbiome data from a number of host animals suggests that substantial Entamoeba diversity remains to be uncovered