11,368 research outputs found
Growth and Survival of the Halophyte Salicornia Europaera L. Under Saline Field Conditions
Author Institution: Department of Botany, Ohio UniversityField investigations were carried out to determine growth and survival rates of Salicornia europaea L. in a saline environment at Rittman, Ohio. Collected data indicated that from 62% to 100% of the seedlings within the 'A saline zones investigated did not survive to maturity. Seedling mortality was statistically correlated at P<0.01 to rising soil salinity stress during late spring and summer. Plant growth was minimal between April and June, increasing sharply during late summer and fall
Variations Electrical Resistance of the Skin in Newborn Infants
Measurements were made of the large variations in apparent electrical resistance of the skin of fifteen newborn infants. Readings were taken every five minutes over two hour periods using a unidirectional current technique. The purpose of the experiment was to check Richter\u27s hypothesis that increases in palmar resistance afford an objective criterion of sleep
Discovery of PAHs in the Halo of NGC 5907
We have used sensitive archival data from the Infrared Space Observatory
(ISO) to make maps of the edge-on low SFR galaxy, NGC 5907, in 6 different MIR
bands: LW2, LW5, LW6, LW7, LW8, and LW10, covering the spectrum from 6.5 to
15.0 microns and including several narrow bands that isolate the infrared
aromatic spectral features commonly referred to as PAHs. Most of the MIR
emission is dominated by PAHs and it is likely that emission from VSGs
contribute only negligibly except in the broad IRAS-equivalent band. The flux
ratios are typical of galaxies with low SFRs or quiesent regions within
galaxies (e.g M~83) and a very high PAH/continuum ratio is observed. The PAH
emission follows the CO distribution and also shows some correlation within the
disk with the lambda 850 micron distribution. However, the PAH emission also
reaches larger galactocentric radii than the CO and other correlations suggest
that the PAHs are also more widespread. A significant new discovery is the
presence of PAHs in the halo of the galaxy. In the narrow bands that isolate
single PAH features, the emission shows structure similar to high latitude
features seen in other galaxies in other tracers. The features extend as far as
6.5 kpc from the plane but scale heights of 3.5 kpc are more typical. The
(lambda 11.3/lambda7.7) ratio also appears to increase with distance from the
major axis. To our knowledge, this is the first time PAHs have been seen in the
halo of an external galaxy. Just as significantly, they are seen in a low SFR
galaxy, suggesting that strong SNe and winds are not necessary for these large
molecules to reach high latitudes.Comment: A&A accept. 8 Sept. 05, 15 pages, 14 fig., pdf at
www.astro.queensu.ca/~irwin/pub/ngc590
Recommended from our members
Sex Differences in the Effect of Inflammation on Subjective Social Status: A Randomized Controlled Trial of Endotoxin in Healthy Young Adults.
It has been established that inflammation leads to a variety of changes in social experience, but one area of social experience that has been overlooked is subjective social status. Furthermore, given sex differences in the relationship between inflammation and social status, males may be more sensitive to inflammation-induced changes in social status. However, no previous studies in humans have examined this possibility. In the present study, healthy young participants (n = 115) were randomly assigned to receive either endotoxin, an experimental inflammatory challenge, or placebo. Participants reported their subjective social status at baseline (prior to injection), and approximately 2 h later (time of peak inflammatory response for the endotoxin group). Results, using ANCOVA analyses, indicated that males exposed to endotoxin, but not females, reported lower levels of subjective social status at the peak of inflammatory response (vs. placebo). These results suggest that males may be more sensitive to the effects of inflammation in certain social domains, such as perceived social status. Clinical Trial Registration: www.ClinicalTrials.gov, identifier NCT01671150
The Andromeda Stream
The existence of a stream of tidally stripped stars from the Sagittarius
Dwarf galaxy demonstrates that the Milky Way is still in the process of
accreting mass. More recently, an extensive stream of stars has been uncovered
in the halo of the Andromeda galaxy (M31), revealing that it too is
cannibalizing a small companion. This paper reports the recent observations of
this stream, determining it spatial and kinematic properties, and tracing its
three-dimensional structure, as well as describing future observations and what
we may learn about the Andromeda galaxy from this giant tidal stream.Comment: 3 Pages. Refereed contribution to the 5th Galacto Chemodynamics
conference held in Swinburne, July 2003. Accepted for publication in PAS
Investigation of reactivity of launch vehicle materials with liquid oxygen Quarterly report, 23 Jul. - 22 Oct. 1968
Reactivity of launch vehicle organic materials with liquid oxyge
Constraining the Collisional Nature of the Dark Matter Through Observations of Gravitational Wakes
We propose to use gravitational wakes as a direct observational probe of the
collisional nature of the dark matter. We calculate analytically the structure
of a wake generated by the motion of a galaxy in the core of an X-ray cluster
for dark matter in the highly-collisional and collisionless limits. We show
that the difference between these limits can be recovered from detailed X-ray
or weak lensing observations. We also discuss the sizes of sub-halos in these
limits. Preliminary X-ray data on the motion of NGC 1404 through the Fornax
group disfavors fluid-like dark matter but does not exclude scenarios in which
the dark matter is weakly collisional.Comment: 29 pages, 3 figures, submitted to Ap
- …