Probing the Active Massive Black Hole Candidate in the Center of NGC 404 with VLBI

Recently Nyland et al. (2012) argued that the radio emission observed in the center of the dwarf galaxy NGC 404 originates in a low-luminosity active galactic nucleus (LLAGN) powered by a massive black hole ($M\sim<10^6$ M$_{\odot}$). High-resolution radio detections of MBHs are rare. Here we present sensitive, contemporaneous Chandra X-ray, and very long baseline interferometry (VLBI) radio observations with the European VLBI Network (EVN). The source is detected in the X-rays, and shows no long-term variability. If the hard X-ray source is powered by accretion, the apparent low accretion efficiency would be consistent with a black hole in the hard state. Hard state black holes are known to show radio emission compact on the milliarcsecond scales. However, the central region of NGC 404 is resolved out on 10 milliarcsecond (0.15-1.5 pc) scales. Our VLBI non-detection of a compact, partially self-absorbed radio core in NGC 404 implies that either the black hole mass is smaller than $3^{+5}_{-2}\times10^5$ M$_{\odot}$, or the source does not follow the fundamental plane of black hole activity relation. An alternative explanation is that the central black hole is not in the hard state. The radio emission observed on arcsecond (tens of pc) scales may originate in nuclear star formation or extended emission due to AGN activity, although the latter would not be typical considering the structural properties of low-ionization nuclear emission-line region galaxies (LINERs) with confirmed nuclear activity.Comment: Accepted for publication in the Astrophysical Journal. 7 pages, 2 figures, 1 tabl

Cord blood angiogenic profile in normotensive pregnancies

Human placenta undergoes both angiogenesis and vasculogenesis during fetal development. An imbalance in proangiogenic [placental growth factor (PlGF) and vascular endothelial growth factor] and antiangiogenic factors [soluble fms like tyrosine kinase-1 (sFlt-1), soluble endoglin (sEng)] has been reported to have a role in pathophysiology of preeclampsia. Hence the present study was designed to analyze heme oxygenase-1 and endoglin levels in maternal and cord blood of normotensive women. The study comprised of twenty five normotensive pregnant women immediately after delivery Study samples were drawn (maternal venous blood and umbilical cord blood) and heme oxygenase-1 (HO-1) and endoglin levels were analyzed by competitive enzyme linked immunosorbent assay. Heme oxygenase-1 levels were elevated in maternal blood as compared to cord blood of normotensive pregnant women. Also, serum blood endoglin levels were higher in maternal blood compared to cord blood of normotensive pregnant women. These findings indicate that there is angiogenic balance during normotensive pregnancy and dysbalance might occur during pathological pregnancy. These markers of angiogenic balance may serve as diagnostic marker and may help in explaining future risk of cardiovascular disease in these women.Keywords: Vasculogenesis; Proangiogenic and antiangiogenic factors; Pregnanc

Relationship between gestational age and endoglin levels in maternal and cord blood

Background: Poor placentation at early gestational age is an important predisposing condition for the development of preeclampsia. The present study was designed to study the relationship of gestational age with endoglin levels in maternal and cord blood of normal and pre-eclamptic women.Methods: The present study was conducted in fifty pregnant women that were grouped as: group 1 (control, n=25) comprising of normotensive women immediately after delivery, group 2 (study group, n=25) comprising of age -and sex- matched pre-eclamptic women. Study samples were drawn (maternal venous blood and umbilical cord blood). Endoglin was analyzed by competitive enzyme linked immunosorbent assay.Results: Maternal serum endoglin levels were decreased in group II as compared to group I. Maternal endoglin showed a positive correlation with gestational age in both normotensive and preeclamptic women. Cord blood endoglin showed negative correlation with gestational age in both normotensive women and preeclamptics. A significant positive correlation was found between maternal and cord blood endoglin levels with birth weight in preeclamptic mothers. Pre-eclamptics with birth weight less than 2.5 kg had lower maternal blood endoglin levels as compared to controls.Conclusions: These finding suggest that endoglin levels may responsible for the pathogenesis of PE and/or IUGR

The peculiar WAT NGC 2329 with Seyfert/FR I-like radio lobes

We report the complex radio properties of the radio galaxy NGC 2329 that resides in the centre of the galaxy cluster Abell 569. For this study, we have used archival data from the Very Large Array (VLA) at various resolutions and frequencies, as well as the Very Long Baseline Array (VLBA). While the wide-angle tailed (WAT) Fanaroff-Riley type I (FR I) radio morphology of the source has been discussed widely in the literature, the nature of the inner lobes has not been as widely discussed. In particular, we note that the inner lobes resemble the bubble-like radio structures observed in Seyfert galaxies. Polarization-sensitive data from the VLA clearly show magnetic field structures consistent with FR Is for the outer lobes and Seyferts for the inner lobes in NGC 2329. FR Is are classified as radio-loud (RL) active galactic nuclei (AGN) and Seyferts as radio-quiet (RQ) AGN, making this source unique. The VLBA shows a one-sided radio jet suggesting a relativistic pc-scale outflow, leading into the inner lobes. Electron lifetime estimates suggest that the outer FR I-like lobes are nearly twice as old (~45 Myr) as the inner Seyfert-like lobes (~25 Myr). Gas inflow in this merging cluster seems to have rejuvenated the AGN about ~25 Myr ago, and may have caused a change in the accretion disc state. The complex composite radio morphology of NGC 2329 suggests that the RL/RQ dichotomy is a function of time in the lifecycle of an AGN

Shocks, Seyferts and the SNR connection: a Chandra observation of the Circinus galaxy

We analyse new Chandra observations of the nearest (D=4 Mpc) Seyfert 2 active galaxy, Circinus, and match them to pre-existing radio, infrared and optical data to study the kpc-scale emission. The proximity of Circinus allows us to observe in striking detail the structure of the radio lobes, revealing for the first time edge-brightened emission both in X-rays and radio. After considering various other possible scenarios, we show that this extended emission in Circinus is most likely caused by a jet-driven outflow, which is driving shells of strongly shocked gas into the halo of the host galaxy. In this context, we estimate Mach numbers M=2.7-3.6 and M=2.8-5.3 for the W and E shells respectively. We derive temperatures of 0.74 (+0.06, -0.05) keV and 0.8-1.8 keV for the W and E shells, and an expansion velocity of ~900-950 km/s. We estimate that the total energy (thermal and kinetic) involved in creating both shells is ~2x10^55 erg, and their age is ~10^6 years. Comparing these results with those we previously obtained for Centaurus A, NGC 3801 and Mrk 6, we show that these parameters scale approximately with the radio power of the parent AGN. The spatial coincidence between the X-ray and edge-brightened radio emission in Circinus resembles the morphology of some SNR shocks. This parallel has been expected for AGN, but has never been observed before. We investigate what underlying mechanisms both types of systems may have in common, arguing that, in Circinus, the edge-brightening in the shells may be accounted for by a B field enhancement caused by shock compression, but do not preclude some local particle acceleration. These results can be extrapolated to other low-power systems, particularly those with late type hosts.Comment: 13 pages, 9 figures, and 5 tables. Accepted for publication in Ap

Physical Properties of Very Powerful FRII Radio Galaxies

We estimate ages and physical properties of powerful radio galaxies. An analysis of new multi-wavelength VLA observations of eleven very powerful classical double (FRIIb) radio galaxies with redshifts between 0.4 and 1.3 is presented. We estimate ages and velocities for each side of each source. The eleven new sources are combined with previously studied samples and the characteristics of the full sample of 31 sources are studied; the full sample includes sources with redshifts between 0.056 and 1.79, and core-hot spot sizes of about 30 to 400 kpc. The velocities are independent of core-hotspot separation, suggesting the rate of growth of a given source is roughly constant over the source lifetime. We combine the rate of growth, width, and pressure of a source to study the beam power, lifetime, energy, and ambient gas density using standard methods previously applied to smaller samples. Typical beam powers are in the range from 1E44 to 1E46 erg/s; we show that this quantity is insensitive to assumptions regarding minimum energy conditions. The beam powers are independent of core-hotspot separation suggesting that the beam power of a given source is roughly constant over the source lifetime. Typical total source lifetimes are found to be about a few E6 to E7 years, and typical total outflow energies (E/c^2) are found to be about 5(E5 - E6) solar masses. Ambient gas densities are found to decrease with increasing core-hotspot distance, but have no redshift dependence. Overall, the results obtained with the sample of 31 sources studied here are consistent with those obtained earlier with smaller samples.Comment: Astronomy and Astrophysics, accepte

Hormetic UV-C seed treatments for the control of tomato diseases

© 2019 British Society for Plant Pathology Hormesis is a dose response phenomenon in which low, non-damaging doses of a stressor bring about a positive response in the organism undergoing treatment. Evidence is provided here that hormetic UV-C treatments of tomato seed can control disease caused by Botrytis cinerea, Fusarium oxysporum f. sp. lycopersici (FOL) and f. sp. radicis-lycopersici (FORL) on tomato (Solanum lycopersicum). Treating seeds with a 4kJm−2 dose of UV-C significantly reduced both the disease incidence and progression of B.cinerea, with approximately 10% reductions in both on cv. Shirley. Disease severity assays for FOL and FORL on cv. Moneymaker showed dose-dependent responses: UV-C treatments of 4 and 6kJm−2 significantly reduced the disease severity scores of FOL, whilst only the 6kJm−2 showed significant reductions for FORL. To determine the effects of treatment on germination and seedling growth, UV-C doses of 4, 8 and 12kJm−2 were performed on cv. Shirley. No negative impacts on germination or seedling growth were observed for any of the treatments. However, the 8kJm−2 treatment showed significant biostimulation, with increases in seedling, root and hypocotyl dry weight of 11.4%, 23.1% and 12.0%, respectively, when compared to the control. Furthermore, significant increases in the root-mass fraction (10.6%) and root:shoot ratio (13.1%) along with a decrease in shoot-mass fraction (2.0%) indicates that the 8kJm−2 treatment stimulated root growth to the greatest extent. There was no effect on hypocotyl and primary root length or the number of lateral roots, indicating no adverse effects to basic root architecture or seedling growth