981 research outputs found
The Black Hole Mass of Abell 1836-BCG and Abell 3565-BCG
Two brightest cluster galaxies (BCGs), namely Abell 1836-BCG and Abell
3565-BCG, were observed with the Advanced Camera for Surveys (ACS) and the
Space Telescope Imaging Spectrograph (STIS) on board the Hubble Space
Telescope. By modeling the available photometric and kinematic data, it
resulted that the mass of Abell 1836-BCG and Abell 3565-BCG are
M_bh=4.8(+0.8,-0.7)x10^9 M_sun and M_bh=1.3(+0.3,-0.4)x10^9 M_sun at 1 sigma
confidence level, respectively.Comment: 4 pages, 3 figures, Mem SAIt in press, Proceedings of the 51st Annual
Meeting of the Italian Astronomical Society, Florence, April 17-20, 200
Experimental Watersheds at Coshocton, Ohio, USA: Experiences and Establishing New Experimental Watersheds
The North Appalachian Experimental Watershed (NAEW) in Ohio was established in 1935 to improve economical and physical sustainability in agriculture. The objectives were to test management practices on small watersheds, investigate scaling of runoff and erosion to larger areas, and research ways to extrapolate the results to ungauged areas. The facility was equipped with a permanent infrastructure consisting of runoff stations and rain gauges for watersheds ranging in size from 0.26 to 1854 ha, and 11 large (0.008 ha) monolith lysimeters to investigate small-scale water balances, all in an area greater than 2000 ha. After about 1970, the NAEW was reduced in size to 425 ha consisting of mostly small watersheds (âtest bedsâ) ranging in size from 0.26 to 3.07 ha. The NAEW was in operation for approximately 81 years generating a long record of runoff and other data for various watersheds, and closed in 2015. A wide variety of experiments were conducted on the NAEW with many high-impact accomplishments and addressing emerging issues that founders never envisioned. Nearly, 500 publications came from investigations during the history of the facility, and insights for establishing new experimental watersheds are presented covering site selection, funding, site specificity, extrapolation of results, generation of runoff in different physiographic regions, collaboration, off-site investigations, and instrumentation. The research on water quality was added to the research objectives in the 1970s, including nutrients (nitrogen and phosphorus) and pesticides in surface runoff and subsurface flow
The Original USDA-ARS Experimental Watersheds in Texas and Ohio: Contributions from the Past and Visions for the Future
The USDA Soil Conservation Service (USDAâSCS) realized the importance of understanding hydrologic processes on agricultural fields and watersheds in the midâ1930s. Based on this realization, the research program of the Hydrologic Division of SCS established three experimental watersheds across the U.S. to analyze the impact of landuse practices on soil erosion, flood events, water resources, and the agricultural economy. Two of the original watersheds remain in operation today within the USDA Agricultural Research Service (USDAâARS): the Blacklands Experimental Watershed (now the Grassland, Soil and Water Research Laboratory) near Riesel, Texas, and the North Appalachian Experimental Watershed near Coshocton, Ohio. These original watersheds were designed for collection of hydrologic data on small watersheds and evaluation of hydrologic and soil loss response as influenced by various agricultural land management practices. A major contribution of these experimental watersheds is the quantification of soil loss reduction under conservation management, which has led to a drastic reduction in soil loss from cultivated agriculture in the 20th century. Riesel watershed studies produced the scientific basis for several watershed models that are now used worldwide to manage water quality and also facilitated fundamental analysis of the agronomic and environmental effects of tillage, fertilizer, and pesticide alternatives. Coshocton watershed studies led to the development of noâtill and pasture management practices to control runoff, erosion, and chemical loss and were instrumental in understanding water quality and hydrologic effects of soil macropores and mining and reclamation activities. The longâterm hydrologic records at each site have also improved understanding and management of water resources in their respective geographic regions. Because of their historical and future value, the USDAâARS has a unique responsibility to maintain these longâterm experimental watersheds, which are vital for addressing emerging research needs to meet future water availability, environmental quality, and food and fiber demands
A prospective trial of surgical resident performed focused abdominal sonography for trauma (FAST): an easy training method
Sentencing Outcomes of Convicted Child Sex Offenders
This research examines the sentencing outcomes of convicted child sexual offenders from data collected over an eight year period. Multiple regression and nominal log linear regression are used to examine length of prison sentence, length of probation sentence, and whether or not the convicted offender is actually sent to prison or to probation. While many independent variables appear to be related to sentence outcome, they fall into three categories: characteristics of the offender, characteristics of the victim, and characteristics of the crime. Additionally, while many variables appear related at the bivariate level, when multivariate analysis is applied, fewer variables remain significant and these are mostly from the characteristics of the offense
Effects of carnitine and its congeners on eicosanoid discharge from rat cells: implications for release of TNFα
THE acyl carrier coenzyme A (CoA) is involved in fatty acid metabolism. The carnitine/CoA ratio is of particular importance in regulating the transport of long-chain fatty acids into mitochondria for oxidation. Also CoA has a role in the formation and breakdown of products from both the cyclooxygenase and lipoxygenase pathways of the precursor arachidonic acid. In the present study the effect of 4 days feeding of 300 mg/kg/day of L-carnitine, acetyl Lcarnitine and propionyl L-carnitine on the basal and calcium ionophore (A23187) stimulated release of arachidonic acid metabolites from rat carrageenin elicited peritoneal cells was investigated. There were two series of experiments carried out. In the first, the harvested peritoneal cell population consisted of less than 90% macrophages and additional polymorphonuclear (PMN) leucocytes. The basal release of prostaglandin E2 (PGE2), 6-ketoprostaglandin F1α (6-keto-PGF1α) and leukotriene B4 (LTB4) was stimulated by all treatments. The A23187 stimulated release of 6-keto-PGF1α and LTB4 was increased by all three compounds. The 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were increased by carnitine treatment. These results suggested that carnitine could modify the macrophage component of an inflammatory site in vivo. In the second series of experiments the harvested cell population was highly purified (>95% macrophages) and none of the compounds fed to the rats caused a change of either eicosanoid or TNFα formation. Moreover the 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 ratios were not enhanced by any of the compounds tested. It is conceivable that in the first series the increased ratios 6-keto-PGF1α:TxB2 and 6-keto-PGF1α:LTB4 reflected the effect of carnitine or its congeners on PMN leucocytes rather than on macrophages
Supermassive Black Holes in BCGs
We observed a sample of three Brightest Cluster Galaxies (BCGs), Abell
1836-BCG, Abell 2052-BCG, and Abell 3565-BCG, with the Advanced Camera for
Surveys (ACS) and the Imaging Spectrograph (STIS) on board the Space Telescope.
For each target galaxy we obtained high-resolution spectroscopy of the Halpha
and [NII]lambda6583 emission lines at three slit positions, to measure the
central ionized-gas kinematics. ACS images in three different filters (F435W,
F625W, and FR656N) have been used to determine the optical depth of the dust,
stellar mass distribution near the nucleus, and intensity map. We present
supermassive black hole (SBH) mass estimates for two galaxies which show
regular rotation curves and strong central velocity gradients, and an upper
limit on the SBH mass of the third one. For the SBHs of Abell 1836-BCG and
Abell 3565-BCG, we derived M_bh=4.8(-0.7,+0.8)10**9 M_sun and
M_bh=1.3(-0.4,+0.3)10**9 M_sun at 1 sigma confidence level, respectively. For
the SBH of Abell 2052-BCG, we found M_bh < 7.3 10**9 M_sun.Comment: 2 pages, 1 figure. To appear in the proceedings of "Black Holes: from
Stars to Galaxies", IAU Symp. No. 238, V. Karas & G. Matt (eds.), Cambridge
University Pres
On the relation between circular velocity and central velocity dispersion in high and low surface brightness galaxies
In order to investigate the correlation between the circular velocity Vc and
the central velocity dispersion of the spheroidal component sigma_c, we
analyzed these quantities for a sample of 40 high surface brightness disc
galaxies (hereafter HSB), 8 giant low surface brightness spiral galaxies
(hereafter LSB), and 24 elliptical galaxies characterized by flat rotation
curves. We find that the Vc-sigma_c relation is descri ed by a linear law out
to velocity dispersions as low as sigma_c~50km/s, while in previous works a
power law was adopted for galaxies with sigma_c>80k/ms.
Elliptical galaxies with Vc based on dynamical models or directly derived
from the HI rotation curves follow the same relation as the HSB galaxies in the
Vc-sigma_c plane. On the contrary, the LSB galaxies follow a different
relation, since most of them show either higher Vc (or lower sigma_c) with
respect to the HSB galaxies. This argues against the relevance of baryon
collapse in the radial density profile of the dark matter haloes of LSB
galaxies. (abridged)Comment: 18 pages, 4 figures, ApJ in pres
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