1,907 research outputs found
Harvester Ant \u3ci\u3e(Pogonomyrmex sp.)\u3c/i\u3e Seed Preferences and Distribution in a Suburban Setting
Harvester ants (Pogonomyrmex sp.) are omnivorous ants native to Texas and are the main food source for the threatened Texas Horned Lizard (Phrynosoma cornutum). Little research has been conducted on harvester ants in the Lower Rio Grande Valley (LRGV) and their interactions with their environment. For this purpose, a variety of experiments were conducted to better understand these interactions and preferences. In CHAPTER I, suburban harvester ants were exposed commonly used cover crop seeds in the LRGV and inoculated seeds via seed depots over the course of 24 hours. We found that harvester ants do have preferences for some seeds over others and are impartial to the addition of inoculum. In CHAPTER II, spatial analysis, elevation, impervious surfaces, and soil moisture were analyzed and compared between areas with and without ant colonies. We found that ant colonies were significantly clustered together within this landscape. Within the larger landscape, elevation but not impervious surface was a significant factor in colony placement. Within the subset area soil moisture was not an important predictor. Determining the specific conditions harvester ant colonies choose to reside in could help citizens take proper measures to reduce the likelihood of colony establishment on their property
Evaluation of Heat Resistance Adequacy and Non Combustible Materials Construction of a Multifunctional Building
Fire in buildings is one of the major threats. This threat is increasing day by day. This problem necessitates the building designers, construction professionals and the fire professional to find the solution. A detailed study with analysis requires towards the existing fire safety measures. This study analysis results will reveals the adequacy of existing measures. In this article one of the multifunctional building is selected as research sample. In this building applied research type is adopted. Case study method is used to study the each component of the building. The planning parameters of the building and the designing of the structural position are observed in depth manner. The non-combustible materials are identified in the construction of the building. The heat resistance adequacy of each components of the building is evaluated with respect to codel recommendations. The basic concept of fire and life safety measures in buildings are common in international, national and the regional level. These recommendations are thoroughly applied in this research work. These works are analyses and the results or findings are derived. These results are summed up and explained about its objectives. The paper is concluded with comprehensive fire safety measures applications in buildings and recommends fire related various factors research in future. The ultimate aim of this article work is to safe guard lives and property in buildings
Piezoelectric mechanism of orientation of stripe structures in two-dimensional electron systems
A piezoelectric mechanism of orientation of stripes in two-dimensional
quantum Hall systems in GaAs heterostructures is considered. The anisotropy of
the elastic moduli and the boundary of the sample are taken into account. It is
found that in the average the stripes line up with the [110] axis. In double
layer systems the wave vector of the stripe structure rotates from the [110] to
[100] axis if the period of density modulation becomes large than the
interlayer distance. From the experimental point of view it means that in
double layer systems anisotropic part of resistivity changes its sign under
variation of the external magnetic field.Comment: 8 page
On the dual cascade in two-dimensional turbulence
We study the dual cascade scenario for two-dimensional turbulence driven by a
spectrally localized forcing applied over a finite wavenumber range
[k_\min,k_\max] (with k_\min > 0) such that the respective energy and
enstrophy injection rates and satisfy
k_\min^2\epsilon\le\eta\le k_\max^2\epsilon. The classical
Kraichnan--Leith--Batchelor paradigm, based on the simultaneous conservation of
energy and enstrophy and the scale-selectivity of the molecular viscosity,
requires that the domain be unbounded in both directions. For two-dimensional
turbulence either in a doubly periodic domain or in an unbounded channel with a
periodic boundary condition in the across-channel direction, a direct enstrophy
cascade is not possible. In the usual case where the forcing wavenumber is no
greater than the geometric mean of the integral and dissipation wavenumbers,
constant spectral slopes must satisfy and , where
() is the asymptotic slope of the range of wavenumbers lower
(higher) than the forcing wavenumber. The influence of a large-scale
dissipation on the realizability of a dual cascade is analyzed. We discuss the
consequences for numerical simulations attempting to mimic the classical
unbounded picture in a bounded domain.Comment: 22 pages, to appear in Physica
Magellan Spectroscopy of AGN Candidates in the COSMOS Field
We present spectroscopic redshifts for the first 466 X-ray and radio-selected
AGN targets in the 2 deg^2 COSMOS field. Spectra were obtained with the IMACS
instrument on the Magellan (Baade) telescope, using the nod-and-shuffle
technique. We identify a variety of Type 1 and Type 2 AGN, as well as red
galaxies with no emission lines. Our redshift yield is 72% down to i_AB=24,
although the yield is >90% for i_AB<22. We expect the completeness to increase
as the survey continues. When our survey is complete and additional redshifts
from the zCOSMOS project are included, we anticipate ~1100 AGN with redshifts
over the entire COSMOS field. Our redshift survey is consistent with an
obscured AGN population that peaks at z~0.7, although further work is necessary
to disentangle the selection effects.Comment: 19 pages, 14 figures. Accepted to ApJS special COSMOS issue. The full
electronic version of Table 2 can be found at
http://shaihulud.as.arizona.edu/~jtrump/tab2.tx
Identifying dynamically young galaxy groups via wide-angle tail galaxies: A case study in the COSMOS field at z=0.53
We present an analysis of a wide-angle tail (WAT) radio galaxy located in a
galaxy group in the COSMOS field at a redshift of z=0.53 (hereafter CWAT-02).
We find that the host galaxy of CWAT-02 is the brightest galaxy in the group,
although it does not coincide with the center of mass of the system. Estimating
a) the velocity of CWAT-02, relative to the intra-cluster medium (ICM), and b)
the line-of-sight peculiar velocity of CWAT-02's host galaxy, relative to the
average velocity of the group, we find that both values are higher than those
expected for a dominant galaxy in a relaxed system. This suggests that
CWAT-02's host group is dynamically young and likely in the process of an
ongoing group merger. Our results are consistent with previous findings showing
that the presence of a wide-angle tail galaxy in a galaxy group or cluster can
be used as an indicator of dynamically young non-relaxed systems. Taking the
unrelaxed state of CWAT-02's host group into account, we discuss the impact of
radio-AGN heating from CWAT-02 onto its environment, in the context of the
missing baryon problem in galaxy groups. Our analysis strengthens recent
results suggesting that radio-AGN heating may be powerful enough to expel
baryons from galaxy groups.Comment: 8 pages, 6 figures, 1 table. Accepted for publication in Ap
A case of isolated splenic tuberculosis
AbstractThere are few cases of isolated splenic tuberculosis reported in the literature internationally, and nearly none from western medical centers. The incidence of tuberculosis has declined in the United States since the 1950s, with 11,585 reported cases in 2009, 21% of which were exclusively extrapulmonary. Splenic tuberculosis occurs mostly as part of miliary tuberculosis in immunocompromised patients. Isolated splenic tuberculosis is extremely rare, particularly in the immunocompetent patient. Patients susceptible to acquiring splenic tuberculosis usually have one of the following risk factors: immunosuppression, preceding pyogenic infections, splenic abnormalities, prior trauma to the spleen, sickle cell disease and other hemopathies, and in the immunocompetent patient another body site infected by M. tuberculosis. In this report we present the case of a young immunocompetent male with no other significant past medical history with isolated splenic tuberculosis
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