X-ray view of four high-luminosity Swift/BAT AGN: Unveiling obscuration and reflection with Suzaku

The Swift/BAT nine-month survey observed 153 AGN, all with ultra-hard X-ray BAT fluxes in excess of 10^-11 erg cm^-2 s^-1 and an average redshift of 0.03. Among them, four of the most luminous BAT AGN (44.73 < Log L(BAT) < 45.31) were selected as targets of Suzaku follow-up observations: J2246.0+3941 (3C 452), J0407.4+0339 (3C 105), J0318.7+6828, and J0918.5+0425. The column density, scattered/reflected emission, the properties of the Fe K line, and a possible variability are fully analyzed. For the latter, the spectral properties from Chandra, XMM-Newton and Swift/XRT public observations were compared with the present Suzaku analysis. Of our sample, 3C 452 is the only certain Compton-thick AGN candidate because of i) the high absorption and strong Compton reflection; ii) the lack of variability; iii) the "buried" nature, i.e. the low scattering fraction (<0.5%) and the extremely low relative [OIII] luminosity. In contrast 3C 105 is not reflection-dominated, despite the comparable column density, X-ray luminosity and radio morphology, but shows a strong long-term variability in flux and scattering fraction, consistent with the soft emission being scattered from a distant region (e.g., the narrow emission line region). The sample presents high (>100) X-to-[OIII] luminosity ratios, confirming the [OIII] luminosity to be affected by residual extinction in presence of mild absorption, especially for "buried" AGN such as 3C 452. Three of our targets are powerful FRII radio galaxies, making them the most luminous and absorbed AGN of the BAT Seyfert survey despite the inversely proportional N_H - L_X relation.Comment: A&A paper in press, 17 page

Fabrication and test of lightweight honeycomb sandwich structures Final report

Fabrication and testing of lightweight honeycomb sandwich structure

Optical and X-ray Properties of the Swift BAT-detected AGN

The Swift Gamma-Ray Burst satellite has detected a largely unbiased towards absorption sample of local ($\approx 0.03$) AGN, based solely on their 14--195 keV flux. In the first 9 months of the survey, 153 AGN sources were detected. The X-ray properties in the 0.3--10 keV band have been compiled and presented based on analyses with XMM-Newton, Chandra, Suzaku, and the Swift XRT (Winter et al. 2009). Additionally, we have compiled a sub-sample of sources with medium resolution optical ground-based spectra from the SDSS or our own observations at KPNO. In this sample of 60 sources, we have classified the sources using standard emission line diagnostic plots, obtained masses for the broad line sources through measurement of the broad H$\beta$ emission line, and measured the [OIII] 5007\AA luminosity of this sample. Based on continuum fits to the intrinsic absorption features, we have obtained clues about the stellar populations of the host galaxies. We now present the highlights of our X-ray and optical studies of this unique sample of local AGNs, including a comparison of the 2--10 keV and 14--195 keV X-ray luminosities with the [OIII] 5007\AA luminosity and the implications of our results towards measurements of bolometric luminosities.Comment: 4 pages, 2 figures, to appear in proceedings for 'X-ray Astronomy 2009', Bologna 09/2009, AIP Conference Series, Eds. A. Comastri, M. Cappi, L. Angelin

Soluble pre-fibrillar tau and β-amyloid species emerge in early human Alzheimer’s disease and track disease progression and cognitive decline

Acknowledgments We would like to gratefully acknowledge all donors and their families for the tissue provided for this study. Human tissue samples were supplied by the Brains for Dementia Research programme, jointly funded by Alzheimer’s Research UK, the Alzheimer’s Society and the Medical Research Council, and sourced from the MRC London Neurodegenerative Diseases Brain Bank, the Manchester Brain Bank, the South West Dementia Brain Bank (SWDBB), the Newcastle Brain Tissue Resource and the Oxford Brain Bank. The Newcastle Brain Tissue Resource and Oxford Brain Bank are also supported by the National Institute for Health Research (NIHR) Units. The South West Dementia Brain Bank (SWDBB) receives additional support from BRACE (Bristol Research into Alzheimer’s and Care of the Elderly). Alz-50, CP13, MC-1 and PHF-1 antibodies were gifted from Dr. Peter Davies and brain lystates from BACE1−/−mice were obtained from Prof Mike Ashford. The work presented here was funded by Alzheimer’s Research UK (Grant refs: ARUKPPG2014A-21 and ARUK-NSG2015-1 to BP and DK and NIH/NIA grants NIH/NINDS R01 NS082730 and R01 AG044372 to NK)Peer reviewedPublisher PD

Optical Spectral Properties of Swift BAT Hard X-ray Selected Active Galactic Nuclei Sources

The Swift Burst Alert Telescope (BAT) survey of Active Galactic Nuclei (AGN) is providing an unprecedented view of local AGNs ( = 0.03) and their host galaxy properties. In this paper, we present an analysis of the optical spectra of a sample of 64 AGNs from the 9-month survey, detected solely based on their 14-195 keV flux. Our analysis includes both archived spectra from the Sloan Digital Sky Survey and our own observations from the 2.1-m Kitt Peak National Observatory telescope. Among our results, we include line ratio classifications utilizing standard emission line diagnostic plots, [O III] 5007 A luminosities, and H-beta derived black hole masses. As in our X-ray study, we find the type 2 sources to be less luminous (in [O III] 5007 A and 14-195 keV luminosities) with lower accretion rates than the type 1 sources. We find that the optically classified LINERs, H II/composite galaxies, and ambiguous sources have the lowest luminosities, while both broad line and narrow line Seyferts have similar luminosities. From a comparison of the hard X-ray (14-195 keV) and [O III] luminosities, we find that both the observed and extinction-corrected [O III] luminosities are weakly correlated with X-ray luminosity. In a study of the host galaxy properties from both continuum fits and measurements of the stellar absorption indices, we find that the hosts of the narrow line sources have properties consistent with late type galaxies.Comment: 84 pages, 20 figures, 17 tables, accepted in Ap

Inflammatory and Angiogenic Protein Detection in the Human Vitreous: Cytometric Bead Assay

Introduction. To evaluate clinical feasibility and reproducibility of cytometric bead assay (CBA) in nondiluted vitreous samples of patients with age-related macular degeneration (ARMD), diabetic macular edema (DME), and central retinal vein occlusion (CRVO). Methods. Twelve patients from a single clinics day qualified for intravitreal injections (ARMD n = 6, DME n = 3, CRVO n = 3) and underwent a combination treatment including a single-site 23 gauge core vitrectomy which yielded a volume of 0.6 mL undiluted vitreous per patient. Interleukin-6 (IL-6), vascular endothelial growth factor isoform A (VEGF-A), and monocyte chemo-attractant protein-1 (MCP-1) were assessed directly from 0.3 mL at the same day (fresh samples). To assess the reproducibility 0.3 ml were frozen for 60 days at −80°, on which the CBA was repeated (frozen samples). Results. In the fresh samples IL-6 was highest in CRVO (median IL-6 55.8 pg/mL) > DME (50.6) > ARMD (3.1). Highest VEGF was measured in CRVO (447.4) > DME (3.9) > ARMD (2.0). MCP-1 was highest in CRVO (595.7) > AMD (530.8) > DME (178). The CBA reproducibility after frozen storage was examined to be most accurate for MCP1 (P = 0.91) > VEGF (P = 0.68) > IL-6 (P = 0.49). Conclusions. CBA is an innovative, fast determining, and reliable technology to analyze proteins in fluids, like the undiluted vitreous, which is important to better understand ocular pathophysiology and pharmacology. There is no influence of intermittent storage at −80° for the reproducibility of the CBA

Chronic cocaine exposure in Drosophila: Life, cell death and oogenesis

AbstractDevelopmental signaling cascades that can be perturbed by cocaine and other drugs of abuse have been difficult to study in humans and vertebrate models. Although numerous direct neural targets of cocaine have been elucidated at the molecular level, little is known about the specific cellular events that are impacted indirectly as a result of the drug's perturbation of neural circuits. We have developed oogenesis in Drosophila melanogaster as a model in which to identify downstream biochemical and/or cellular processes that are disrupted by chronic cocaine exposure. In this model, cocaine feeding resulted not only in expected reductions in viability, but also in unanticipated developmental defects during oogenesis, including aberrant follicle morphogenesis and vitellogenic follicle degeneration. To identify mechanisms through which cocaine exerted its deleterious effects on oogenesis, we examined candidate components of neural and hormonal signaling pathways. Cocaine-induced disruptions in follicle formation were enhanced by juvenile hormone exposure and phenocopied by serotonin feeding, while cocaine-activated follicle apoptosis was enhanced by concomitant dopamine feeding. HPLC analysis of dopamine and serotonin in the ovary suggests that these neurotransmitters could variably mediate cocaine's effects on oogenesis indirectly in the brain and/or directly in the ovary itself. We confirmed the involvement of hormone signaling by measuring ecdysteroids, which increase following cocaine exposure, and by demonstrating suppression of cocaine-induced follicle loss by hormone receptor mutants. Cocaine-induced ovarian follicle apoptosis and adult lethality appear to be caused by modulation of dopamine levels, while morphological defects during follicle formation likely result from perturbing serotonin signaling during cocaine exposure. Our work suggests not only a new role for juvenile hormone and/or serotonin in Drosophila ovarian follicle formation, but also a cocaine-sensitive role for dopamine in modulating hormone levels in the female fly