1,353 research outputs found
POTENTIAL INCOME EFFECTS OF THE HARKIN-GEPHARDT PROPOSAL ON NEW YORK DAIRY FARMS
This article reports the results of research regarding the farm-level implications for New York dairy producers of national mandatory supply control programs for feed grains and milk. The analysis is based on the proposed Harkin-Gephardt Bill which would authorize a mandatory supply control program for milk and the major supported crops. Representative farm budgets were constructed for a sample of dairy farms to assess the possible effects on costs and returns. Some farmers would gain, while others would not. The results suggest that dairy farmers who purchase all of their feed would be worse off, while farmers who grow grain would be better off under the proposed supply control program.Agricultural Finance,
Real-time determination of laser beam quality by modal decomposition
We present a real-time method to determine the beam propagation ratio M2 of
laser beams. The all-optical measurement of modal amplitudes yields M2
parameters conform to the ISO standard method. The experimental technique is
simple and fast, which allows to investigate laser beams under conditions
inaccessible to other methods.Comment: 8 pages, 4 figures, published in Optics Expres
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Consolidation of Geologic Studies of Geopressured-Geothermal Resources in Texas
Detailed structural mapping at several horizons in selected study areas within the Frio growth-fault trend demonstrates a pronounced variability in structural style. At Sarita in South Texas, shale mobilization produced one or more shale ridges, one of which localized a low-angle growth fault trapping a wedge of deltaic sediments. At Corpus Christi, shale mobilization produced a series of large growth faults, shale-cored domed anticlines, and shale-withdrawal basins, which become progressively younger basinward. At Blessing, major growth faults trap sands of the Greta/Calhoun barrier system, having some discrete shale diapirs but little progradation. At Pleasant Bayou, a major early growth-fault system was overprinted by salt tectonics—the intrusion of Danbury Dome and the development of a salt-withdrawal basin. At Port Arthur, low-displacement, long-lived faults formed on a sand-poor shelf margin contemporaneously with broad salt uplifts and basins. Variability in styles can be related to the nature and extent of Frio sedimentation and shelf-margin progradation and to the presence of salt. Structural styles that are conducive to large geothermal reservoirs include blocks between widely spaced growth faults having dip reversal, salt-withdrawal basins, and shale-withdrawal basins. These styles are widespread on the Texas Gulf Coast. However, actually finding a large reservoir depends on demonstrating the existence of sufficient sand having adequate quality to support geopressured geothermal energy production.Bureau of Economic Geolog
Identification and characterization of microsatellite loci in two socially complex old world tropical babblers (Family Timaliidae)
Background:
Although the highest diversity of birds occurs in tropical regions, little is known about the genetic mating systems of most tropical species. We describe microsatellite markers isolated in the chestnut-crested yuhina (Staphida everetti), endemic to the island of Borneo, and the grey-throated babbler (Stachyris nigriceps), widely distributed across Southeast Asia. Both species belong to the avian family Timaliidae and are highly social, putatively cooperatively breeding birds in which helpers attend the nests of members of their social group. We obtained DNA from individuals in social groups breeding in Kinabalu Park, Malaysian Borneo.
Results:
We used a shotgun sequencing approach and 454-technology to identify 36 microsatellite loci in the yuhina and 40 in the babbler. We tested 13 primer pairs in yuhinas and 20 in babblers and characterized eight polymorphic loci in 20 unrelated female yuhinas and 21 unrelated female babblers. Polymorphism at the yuhina loci ranged from 3 to 9 alleles, observed heterozygosities from 0.58 to 1.00, and expected heterozygosities from 0.64 to 0.81. Polymorphism at the babbler loci ranged from 3 to 12 alleles, observed heterozygosities from 0.14 to 0.90 and expected heterozygosities from 0.14 to 0.87. One locus in the yuhina deviated significantly from Hardy–Weinberg equilibrium. We detected nonrandom allele associations between two pairs of microsatellite loci in each species.
Conclusions:
Microsatellite markers will be used to describe the genetic mating system of these socially complex species and to measure genetic parentage and relatedness within social groups
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Mined Lands Inventory, Industrial Minerals, South Texas
The Bureau of Economic Geology, under an interagency cooperative contract with
the Railroad Commission of Texas, conducted a comprehensive inventory of abandoned
and active mining operations across 48 counties in South Texas. Project objectives
were to characterize potential reclamation, or priority, sites, to create a surface-mining
database of industrial minerals, and to provide data to meet future legislative and
regulatory needs.
Comprehensive procedures were established for identification and evaluation of
mined lands using U.S. Geological Survey topographic maps, black-and-white and
color-infrared aerial photographs, on-site surveys, and low-altitude flyovers. The site
location, mineral commodity, and relative size were recorded on a Mined Lands
Inventory Form (MLIF) for each site greater than 2 acres in size. Data on health,
safety, and environmental aspects were recorded for all priority sites. All data were
entered into the Texas Mined Land Database (TMLDB), a computer database that
follows the format of the MLIF. Locations of all inventoried sites are shown on over
400 topographic maps.Bureau of Economic Geolog
Semiclassical Theory of Quantum Chaotic Transport: Phase-Space Splitting, Coherent Backscattering and Weak Localization
We investigate transport properties of quantized chaotic systems in the short
wavelength limit. We focus on non-coherent quantities such as the Drude
conductance, its sample-to-sample fluctuations, shot-noise and the transmission
spectrum, as well as coherent effects such as weak localization. We show how
these properties are influenced by the emergence of the Ehrenfest time scale
\tE. Expressed in an optimal phase-space basis, the scattering matrix
acquires a block-diagonal form as \tE increases, reflecting the splitting of
the system into two cavities in parallel, a classical deterministic cavity
(with all transmission eigenvalues either 0 or 1) and a quantum mechanical
stochastic cavity. This results in the suppression of the Fano factor for
shot-noise and the deviation of sample-to-sample conductance fluctuations from
their universal value. We further present a semiclassical theory for weak
localization which captures non-ergodic phase-space structures and preserves
the unitarity of the theory. Contrarily to our previous claim [Phys. Rev. Lett.
94, 116801 (2005)], we find that the leading off-diagonal contribution to the
conductance leads to the exponential suppression of the coherent backscattering
peak and of weak localization at finite \tE. This latter finding is
substantiated by numerical magnetoconductance calculations.Comment: Typos in central eqns corrected (this paper supersedes
cond-mat/0509186) 20page
An algorithm for the direct reconstruction of the dark matter correlation function from weak lensing and galaxy clustering
The clustering of matter on cosmological scales is an essential probe for
studying the physical origin and composition of our Universe. To date, most of
the direct studies have focused on shear-shear weak lensing correlations, but
it is also possible to extract the dark matter clustering by combining
galaxy-clustering and galaxy-galaxy-lensing measurements. In this study we
develop a method that can constrain the dark matter correlation function from
galaxy clustering and galaxy-galaxy-lensing measurements, by focusing on the
correlation coefficient between the galaxy and matter overdensity fields. To
generate a mock galaxy catalogue for testing purposes, we use the Halo
Occupation Distribution approach applied to a large ensemble of N-body
simulations to model pre-existing SDSS Luminous Red Galaxy sample observations.
Using this mock catalogue, we show that a direct comparison between the excess
surface mass density measured by lensing and its corresponding galaxy
clustering quantity is not optimal. We develop a new statistic that suppresses
the small-scale contributions to these observations and show that this new
statistic leads to a cross-correlation coefficient that is within a few percent
of unity down to 5 Mpc/h. Furthermore, the residual incoherence between the
galaxy and matter fields can be explained using a theoretical model for
scale-dependent bias, giving us a final estimator that is unbiased to within
1%. We also perform a comprehensive study of other physical effects that can
affect the analysis, such as redshift space distortions and differences in
radial windows between galaxy clustering and weak lensing observations. We
apply the method to a range of cosmological models and show the viability of
our new statistic to distinguish between cosmological models.Comment: 23 pages, 14 figures, accepted by PRD; minor changes to V1, 1 new
figure, more detailed discussion of the covariance of the new ADSD statisti
Quasars: What turns them off?
(Abridged) We explore the idea that the anti-hierarchical turn-off observed
in the quasar population arises from self-regulating feedback, via an outflow
mechanism. Using a detailed hydrodynamic simulation we calculate the luminosity
function of quasars down to a redshift of z=1 in a large, cosmologically
representative volume. Outflows are included explicitly by tracking halo
mergers and driving shocks into the surrounding intergalactic medium. Our
results are in excellent agreement with measurements of the spatial
distribution of quasars, and we detect an intriguing excess of galaxy-quasar
pairs at very short separations. We also reproduce the anti-hierarchical
turnoff in the quasar luminosity function, however, the magnitude of the
turn-off falls short of that observed as well as that predicted by analogous
semi-analytic models. The difference can be traced to the treatment of gas
heating within galaxies. The simulated galaxy cluster L_X-T relationship is
close to that observed for z~1 clusters, but the simulated galaxy groups at z=1
are significantly perturbed by quasar outflows, suggesting that measurements of
X-ray emission in high-redshift groups could well be a "smoking gun" for the
AGN heating hypothesis.Comment: 16 pages, 11 figures, submitted to ApJ, comments welcome
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Mined Lands Inventory, Industrial Minerals, East Texas
The Bureau of Economic Geology, under an interagency cooperative contract with the Railroad Commission of Texas, conducted a comprehensive inventory of abandoned and active mining operations across 84 counties in East Texas. This report represents the second phase of the inventory, begun in 1988 in South Texas (Jackson and others, 1989). Project objectives were to characterize potential reclamation, or priority, sites, to create a surface-mining database of industrial minerals, and to provide data to meet future legislative and regulatory needs.
Comprehensive procedures were established for identification and evaluation of mined lands using U.S. Geological Survey topographic maps, black-and-white and color-infrared aerial photographs, on-site surveys, and low-altitude flyovers. The site location, mineral commodity, and relative size were recorded on a Mined Lands Inventory Form (MLIF) for each site greater than 2 acres. Data on health, safety, and environmental aspects were recorded for all priority sites. All data were entered into the Texas Mined Lands Database (TMLDB), a computer database that follows the format of the MLIF. Locations of all inventoried sites are shown on over 600 topographic maps.
In East Texas, 6,492 mined sites were identified, 3,341 greater than 2 acres, 3,112 less than 2 acres, and 39 of undetermined size. Among sites larger than 2 acres, approximately 1,637 are abandoned, 1,166 are active, and 573 are reclaimed. An estimated 140,000 acres have been disturbed by surface mining, predominantly by sand and gravel mining. Other commodities mined in the East Texas area include limestone, clay, and iron ore.Bureau of Economic Geolog
A Detailed Far-Ultraviolet Spectral Atlas of O-Type Stars
In this paper we present a spectral atlas covering the wavelength interval
930--1188A for O2--O9.5 stars using Far Ultraviolet Spectroscopic Explorer
archival data. The stars selected for the atlas were drawn from three
populations: Galactic main sequence (class III-V) stars, supergiants, and main
sequence stars in the Magellanic Clouds, which have low metallicities. For each
of these stars we have prepared FITS files comprised of paris of merged spectra
for user access via the Multi-Mission Archives at Space Telescope. We chose
spectra from the first population with spectral types O4, O5, O6, O7, O8, and
O9.5 and used them to compile tables and figures with identifications of all
possible atmospheric and ISM lines in the region 949-1188A. Our identified line
totals for these six representative spectra are 821 (500), 992 (663), 1077
(749), 1178 (847), 1359 (1001), and 1798 (1392) lines, respectively, where the
numbers in parentheses are the totals of lines formed in the atmospheres,
according to spectral synthesis models. The total number of unique atmospheric
identifications for the six main sequence O star template spectra is 1792,
whereas the number of atmospheric lines in common to these spectra is 300. The
number of identified lines decreases toward earlier types (increasing effective
temperature), the whlle percentages of "missed" features (lines not predicted
from our spectral syntheses) drops from a high of 8% at type B0.2, from our
recently published B star far-UV atlas, to 1--3% for type O spectra. The
percentages of overpredicted lines are similar, despite their being much higher
for B star spectra. We also discuss the statistics of line populations among
the various elemental ionization states. Finally, as an aid to users we list
those isolated lines that can be used to determine stellar temperatures and the
presence of possible chemical anomalies.Comment: To appear in Astrophysical Journal Supplements: 18 pages, 6 tables, 4
figures. Tables 3, 4, and 6 in full may be accessed from the MAST archvies at
(http://archive.stsci.edu/prepds/fuvostars
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