612 research outputs found
The rationale for attempting to define salt marsh mosquito-breeding areas in Galveston County by remote sensing the associated vegetation
The rationale for attempting to define salt marsh mosquito breeding areas in Galveston County was discussed, including a botanical survey of the marsh plant communities, their relationship to flooding, and their exposure to salt water. Particular emphasis is given to Distichlis spicata, a widespread marsh grass. Evidence suggests that breeding areas of Aedes sollicitans are associated with Distichlis and that both species respond to similar ecological conditions in the salt marsh. Aspects of the remote sensing of the Distichlis are considered
Meteorological limits on the growth and development of screwworm populations
A program to evaluate the use of remotely sensed data as an additional tool in existing and projected efforts to eradicate the screwworm began in 1973. Estimating weather conditions by use of remotely sensed data was part of the study. Next, the effect of weather on screwworm populations was modeled. A significant portion of the variation in screwworm population growth and development has been traced to weather-related parameters. This report deals with the salient points of the weather and the screwworm population interaction
The ecological variations in thermal infrared emissivity of vegetation
The author has identified the following significant results. Through a series of contrasts, the statistical significance of differences in emissivity was determined for vegegation in dry and humid deserts, montane and deciduous rain forests, and the temperate region. No significant differences were found between the two types of desert vegetation or among the types of nondesert vegetation. However, the rain forest vegetation was significantly different from that of the temperate region. On a community-wide level, there is some physiological adaptation in plants to their radiational environment
The Distribution of Redshifts in New Samples of Quasi-stellar Objects
Two new samples of QSOs have been constructed from recent surveys to test the
hypothesis that the redshift distribution of bright QSOs is periodic in
. The first of these comprises 57 different redshifts among all
known close pairs or multiple QSOs, with image separations 10\arcsec,
and the second consists of 39 QSOs selected through their X-ray emission and
their proximity to bright comparatively nearby active galaxies. The redshift
distributions of the samples are found to exhibit distinct peaks with a
periodic separation of in identical to that claimed
in earlier samples but now extended out to higher redshift peaks and 4.47, predicted by the formula but never seen before. The periodicity
is also seen in a third sample, the 78 QSOs of the 3C and 3CR catalogues. It is
present in these three datasets at an overall significance level -
, and appears not to be explicable by spectroscopic or similar
selection effects. Possible interpretations are briefly discussed.Comment: submitted for publication in the Astronomical Journal, 15 figure
Critical Examinations of QSO Redshift Periodicities and Associations with Galaxies in Sloan Digital Sky Survey Data
We have used the publicly available data from the Sloan Digital Sky Survey
and 2dF QSO Redshift Survey to test the hypothesis that QSOs are ejected from
active galaxies with periodic non-cosmological redshifts. For two different
intrinsic redshift models, namely the Karlsson model and Bell's
decreasing intrinsic redshift (DIR) model, we do two tests respectively. First,
using different criteria, we generate four sets of QSO-galaxy pairs and find
there is no evidence for a periodicity at the predicted frequency in
, or at any other frequency. We then check the relationship between
high redshift QSOs and nearby active galaxies, and we find the distribution of
projected distance between high redshift QSOs and nearby active galaxies and
the distribution of redshifts of those active galaxies are consistent with a
distribution of simulated random pairs, completely different from Bell's
previous conclusion. We also analyze the periodicity in redshifts of QSOs, and
no periodicity is found in high completeness samples, contrary to the DIR
model. These results support that QSOs are not ejected from active galaxies.Comment: 25 pages, 13 figures, accepted for publication in Ap
Image Analysis to Determine Intramuscular Fat in Muscle
The area of intramuscular fat in Holstein steer longissimus was determined using an image analyzing system. Slaughter weights of 500, 636 and 773 kg differed (p \u3c 0.05) for intramuscular fat area, marbling score, and ether extractable lipid . Repeated measurements of intramuscular fat area in a given section showed high accuracy . However, comparing two sections from the same sample, there was often a large difference in fat content between the sections. Fat content determined by the imaging system was correlated significantl y with marbling score (r = 0.49) and ether extractable lipid (r = 0.34). Sampling is critical, and in order to obtain a high correlation several samples would be required from each muscle
A bias in optical observations of high redshift luminous infrared galaxies
We present evidence for the dramatically different morphology between the
rest frame UV and 7micron mid-IR emission of VV114 and Arp299, two nearby (z~0)
violently interacting infrared luminous galaxies (LIRGs). Nearly all LIRGs are
interacting systems and it is currently accepted that they dominate the IR
emission at z>1. Luminous IR galaxies located at z=1-2 could easily be detected
as unresolved sources in deep optical/near-IR ground based surveys, as well as
in upcoming 24micron surveys with the Space Infrared Telescope Facility. We
demonstrate that the spatial resolution of these surveys will result in
blending of the emission from unresolved interacting components. An increased
scatter will thus be introduced in the observed optical to mid-IR colors of
these galaxies, leading to a systematic underestimation of their dust content.Comment: To appear in the Astrophysical Journal Letters (4 pages 1 figure
Peculiar Features of the Velocity Field of OB Associations and the Spiral Structure of the Galaxy
Some of the peculiar features of the periodic velocity-field structure for OB
associations can be explained by using the model of Roberts and Hausman (1984),
in which the behavior of a system of dense clouds is considered in a perturbed
potential. The absence of statistically significant variations in the azimuthal
velocity across the Carina arm, probably, results from its sharp increase
behind the shock front, which is easily blurred by distance errors. The
existence of a shock wave in the spiral arms and, at the same time, the
virtually free motion of OB associations in epicycles can be reconciled in the
model of particle clouds with a mean free path of 0.2-2 kpc. The velocity field
of OB associations exhibits two appreciable nonrandom deviations from an ideal
spiral pattern: a 0.5-kpc displacement of the Cygnus- and Carina-arm fragments
from one another and a weakening of the Perseus arm in quadrant III. However,
the identified fragments of the Carina, Cygnus, and Perseus arms do not belong
to any of the known types of spurs.Comment: 14 pages, 3 postscript figures, to be published in Astronomy Letter
Blue Straggler Stars: Early Observations that Failed to Solve the Problem
In this chapter, I describe early ideas on blue stragglers, and various
observations (some published, some not) that promised but failed to resolve the
question of their origin. I review the data and ideas that were circulating
from Allan Sandage's original discovery in 1953 of "anomalous blue stars" in
the globular cluster M3, up until about 1992, when what seems to have been the
only previous meeting devoted to Blue Straggler Stars (BSSs) was held at the
Space Telescope Science Institute.Comment: Chapter 2, in Ecology of Blue Straggler Stars, H.M.J. Boffin, G.
Carraro & G. Beccari (Eds), Astrophysics and Space Science Library, Springe
Interest in healthy living outweighs presumed cultural norms for obesity for Ghanaian women
BACKGROUND: Cultural norms indicate that obesity reflects increased wealth and prosperity. Yet obesity is linked to serious medical illnesses. The purpose of this study was to determine if Ghanaian women would change their body image if it meant a healthier life. METHODS: A questionnaire was administered to 305 Ghanaian women waiting for clinic appointments at Korle Bu Teaching Hospital, Accra Ghana. This survey included questions on current health, selection of figural stimuli, decision making on health and social determinants and 5 questions on self-perception of health from SF-36. Anthropometric measures were taken and body mass index calculated. Women were also provided with health related information at the conclusion of the interview. RESULTS: The majority of all women surveyed would reduce their current body image if it meant that they would have an overall healthier life and reduce the risks of obesity-linked illnesses and complications. Currently obese women were significantly more likely than non-obese women to reduce their body image to reduce the risk of hypertension (OR 2.03 [1.64 – 2.51],<0.001); cardiovascular accident (OR 1.96 [1.61 – 2.38],<0.001); diabetes (OR 2.00 [1.63 – 2.44],<0.001); myocardial infarction (OR 2.27 [1.80 – 2.86],<0.001); if requested by a spouse(OR 2.64 [1.98 – 3.52],<0.001); and to improve overall health (OR 1.95 [1.60 – 2.37], <0.001). There was no association with current body image and responses to SF-36. The decision to select a new body image was not influenced by education, income, marital status or parity. Age 50 years old and less was significantly associated with the body image size reduction to reduce the risk of hypertension, diabetes, and a cardiovascular accident. CONCLUSION: The Ghanaian women interviewed in this study are interested in living a healthy life and are willing to reduce their body size to reduce the risk of obesity-linked illnesses. The target group for any interventional studies and measures to reduce obesity appears to be women age 50 and younger
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