3,711 research outputs found
MAGIICAT V. Orientation of Outflows and Accretion Determine the Kinematics and Column Densities of the Circumgalactic Medium
We investigate the dependence of gas kinematics and column densities in the
MgII-absorbing circumgalactic medium on galaxy color, azimuthal angle, and
inclination to trace baryon cycle processes. Our sample of 30 foreground
isolated galaxies at , imaged with the Hubble Space
Telescope, are probed by background quasars within a projected distance of
kpc. From the high-resolution ( km s)
quasar spectra, we quantify the extent of the absorber velocity structure with
pixel-velocity two-point correlation functions. Absorbers with the largest
velocity dispersions are associated with blue, face-on ()
galaxies probed along the projected minor axis (), while
those with the smallest velocity dispersions belong to red, face-on galaxies
along the minor axis. The velocity structure is similar for edge-on () galaxies regardless of galaxy color or azimuthal angle, for red
galaxies with azimuthal angle, and for blue and red galaxies probed along the
projected major axis (). The cloud column densities for
face-on galaxies and red galaxies are smaller than for edge-on galaxies and
blue galaxies, respectively. These results are consistent with biconical
outflows along the minor axis for star-forming galaxies and accreting and/or
rotating gas, which is most easily observed in edge-on galaxies probed along
the major axis. Gas entrained in outflows may be fragmented with large velocity
dispersions, while gas accreting onto or rotating around galaxies may be more
coherent due to large path lengths and smaller velocity dispersions. Quiescent
galaxies may exhibit little-to-no outflows along the minor axis, while
accretion/rotation may exist along the major axis.Comment: 12 pages, 6 figures, 1 table. Accepted for publication in Ap
Diffuse Interstellar Bands in z < 0.6 CaII Absorbers
The diffuse interstellar bands (DIBs) probably arise from complex organic
molecules whose strength in local galaxies correlates with neutral hydrogen
column density, N(HI), and dust reddening, E(B-V). Since CaII absorbers in
quasar (QSO) spectra are posited to have high N(HI) and significant E(B-V),
they represent promising sites for the detection of DIBs at cosmological
distances. Here we present the results from the first search for DIBs in 9
CaII-selected absorbers at 0.07 < z_abs < 0.55. We detect the 5780Ang DIB in
one line of sight at z_abs = 0.1556; this is only the second QSO absorber in
which a DIB has been detected. Unlike the majority of local DIB sight-lines,
both QSO absorbers with detected DIBs show weak 6284Ang absorption compared
with the 5780Ang band. This may be indicative of different physical conditions
in intermediate redshift QSO absorbers compared with local galaxies. Assuming
that local relations between the 5780Ang DIB strength and N(HI) and E(B-V)
apply in QSO absorbers, DIB detections and limits can be used to derive N(HI)
and E(B-V). For the one absorber in this study with a detected DIB, we derive
E(B-V) = 0.23mag and log[N(HI)] >= 20.9, consistent with previous conclusions
that CaII systems have high HI column densities and significant reddening. For
the remaining 8 CaII-selected absorbers with 5780Ang DIB non-detections, we
derive E(B-V) upper limits of 0.1-0.3mag.Comment: 5 pages, 2 figures. Accepted to MNRAS Letter
14-An Archaeological Survey along Portage River and Dorrance Creek above Indian Lake in Pavilion Township, Kalamazoo County, Michigan
For three weeks during the 1982 field season, the Western Michigan University archaeological field school was located near Indian Lake in Pavilion Township, T3S RlOW, Kalamazoo County, Michigan (Map 1). As part of the research program, systematic site location survey was planned for this area;one which had not received any prior archaeological attention. With the cooperation of area landowners and the assistance of several local artifact collectors, more than 20 parcels of cultivated land aggregating 3.9 km2 were evaluated by means of surface re~onnaissance or walk-over survey. There follows a report of survey activity, together with descriptions of the archaeological sites recorded
Efficient Activation of Reconstructed Rat Embryos by Cyclin-Dependent Kinase Inhibitors
This Article is brought to you for free and open access by the Molecular and Cellular Biochemistry at UKnowledge. It has been accepted for inclusion in Molecular and Cellular Biochemistry Faculty Publication by an authorized administrator of UKnowledge. For more information, please contac
Selective superoxide generation within mitochondria by the targeted redox cycler MitoParaquat
Superoxide is the proximal reactive oxygen species (ROS) produced by the mitochondrial respiratory chain and plays a major role in pathological oxidative stress and redox signaling. While there are tools to detect or decrease mitochondrial superoxide, none can rapidly and specifically increase superoxide production within the mitochondrial matrix. This lack impedes progress, making it challenging to assess accurately the roles of mitochondrial superoxide in cells and in vivo. To address this unmet need, we synthesized and characterized a mitochondria-targeted redox cycler, MitoParaquat (MitoPQ) that comprises a triphenylphosphonium lipophilic cation conjugated to the redox cycler paraquat. MitoPQ accumulates selectively in the mitochondrial matrix driven by the membrane potential. Within the matrix, MitoPQ produces superoxide by redox cycling at the flavin site of complex I, selectively increasing superoxide production within mitochondria. MitoPQ increased mitochondrial superoxide in isolated mitochondria and cells in culture ~a thousand-fold more effectively than untargeted paraquat. MitoPQ was also more toxic than paraquat in the isolated perfused heart and in Drosophila in vivo. MitoPQ enables the selective generation of superoxide within mitochondria and is a useful tool to investigate the many roles of mitochondrial superoxide in pathology and redox signaling in cells and in vivo
Long-Term Adult Population Fluctuations and Distribution of the Spot, Leiostomus xanthurus, in Mississippi
Adult specimens of the spot, Leiostomus xanthurus, were collected from bayou, Mississippi Sound, and barrier island locations along the Gulf Coast of Mississippi from November 1982 to July 1989. The mean total length of all spot sampled in comparable gill net sets was 219 mm (Β± 14 standard deviation, n=4,338). Ninety-five percent of the spot were collected in the island and sound areas, where the salinity was higher than in the bayous. Catch per unit effort was high at island and sound stations in spring and autumn, with relatively few fish caught during the winter spawning season and summer. The relatively high frequency of spot observed at the island stations in the autumn was probably influenced by spawning migrations, and the high spring values may repesent a combination of two abundant year classes. The two greatest yearly collections, in 1983 and 1986, may have been influenced by sampling conditions or by environmental conditions favorable to survival either during those years or earlier when those fish were postlarvae. The smallest yearly catch occurred in 1985 and may have reflected the harsh weather conditions that year
Long-Term Adult Population Fluctuations and Distribution of the Spot, Leiostomus xanthurus, in Mississippi
Adult specimens of the spot, Leiostomus xanthurus, were collected from bayou, Mississippi Sound, and barrier island locations along the Gulf Coast of Mississippi from November 1982 to July 1989. The mean total length of all spot sampled in comparable gill net sets was 219 mm (Β± 14 standard deviation, n=4,338). Ninety-five percent of the spot were collected in the island and sound areas, where the salinity was higher than in the bayous. Catch per unit effort was high at island and sound stations in spring and autumn, with relatively few fish caught during the winter spawning season and summer. The relatively high frequency of spot observed at the island stations in the autumn was probably influenced by spawning migrations, and the high spring values may repesent a combination of two abundant year classes. The two greatest yearly collections, in 1983 and 1986, may have been influenced by sampling conditions or by environmental conditions favorable to survival either during those years or earlier when those fish were postlarvae. The smallest yearly catch occurred in 1985 and may have reflected the harsh weather conditions that year
Anderson et al. Reply (to the Comment by Murphy on Pioneer 10/11)
We conclude that Murphy's proposal (radiation of the power of the main-bus
electrical systems from the rear of the craft) can not explain the anomalous
Pioneer acceleration.Comment: LaTex, 3 pages, Phys. Rev. Lett. (to be published
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