1,025 research outputs found
Effects of Chick Stimuli and Dieldrin on Adoptive Behavior of Penned Hen Pheasants
Studies to determine the effect of chick stimuli and dieldrin on adoptive behavior of penned hen pheasants were conducted in 1969 and 1970. Results indicated that whether caged hens saw or heard chicks had no effect on adoption or killing of chicks. Hens receiving sound stimuli and sight-and-sound stimuli from chicks responded similarly to hens receiving no stimuli. Sub-lethal doses of dieldrin also had no effect on chick adoption under the conditions of this study. Results demonstrated that non-incubating pheasant hens will adopt and brood orphan chicks. During the 2 years of the study, respectively, 37 and 49 percent of the hens tested for adoptive behavior adopted and brooded chicks, 38 and 26 percent intentionally killed chicks, 6 and 14 percent both adopted and killed chicks, and 18 and 11 percent neither adopted nor killed orphan chicks
Screening methods for age-related hearing loss in older patients with cancer: A review of the literature
© 2018 by the authors. As people grow older, they may experience loss in hearing sensitivity. Age-related hearing loss may negatively affect the patient's quality of life as it may lead to social isolation. In older patients with cancer, hearing loss can seriously interfere with the patient's ability to deal properly with all aspects of their disease, and may have a cumulative effect on their already decreased quality of life. Therefore, the proper screening of those conditions is essential in order to optimise the patient's comfort during and after treatment. This review article aims at providing a concise image of the nature of age-related hearing loss, and provides an overview of the screening methods that could be used in older patients with cancer
X-ray and Optical Study of Low Core Density Globular Clusters NGC6144 and E3
We report on the Chandra X-ray Observatory and Hubble Space Telescope
observation of two low core density globular clusters, NGC6144 and E3. By
comparing the number of X-ray sources inside the half-mass radius to those
outside, we found 6 X-ray sources within the half-mass radius of NGC6144, among
which 4 are expected to be background sources; 3 X-ray sources are also found
within the half-mass radius of E3, of which 3 is expected to be background
source. Therefore, we cannot exclude that all our sources are background
sources. However, combining the results from X-ray and optical observations, we
found that 1-2 sources in NGC6144 and 1 source in E3 are likely to be
cataclysmic variables and that 1 source in NGC6144 is an active binary, based
on the X-ray and optical properties. The number of faint X-ray sources in
NGC6144 and E3 found with Chandra and HST is higher than a prediction based on
collision frequency, but is closer to that based on mass. Our observations
strongly suggest that the compact binary systems in NGC6144 and E3 are
primordial in origin.Comment: 28 pages, 9 figures, 6 tables, Accepted for publication in Ap
Comorbidities and Pregnancy Do Not Affect Local Recurrence in Patients With Giant Cell Tumour of Bone
This study evaluates the relationship between pregnancy, comorbid conditions and giant cell tumour of bone. Furthermore, it examines if pregnancy and comorbid conditions affect the outcome following treatment for this tumour. A multi-centre retrospective review was conducted of consecutive patients with a confirmed histological diagnosis of giant cell tumour of bone between June 2012 and May 2017. A total of 195 patients were identified from two centres. Of these, 168 patients were treated with curative intent and had more than six months follow-up. Data were collected on pregnancy status, comorbid conditions, site of disease, surgical management and local recurrence rates. Statistical analysis included the Fisher exact test and Kaplan-Meier survival analysis. There were 72 females of childbearing age, of which 15 (21%) were currently pregnant or had been pregnant within the last six months. The pregnancy rate is higher than the highest reported pregnancy rate over the last 10 years (8.4%; Fisher test, p = 0.033). Women were more likely to have a comorbid condition than men (Fisher test, p < 0.002) and had a higher rate of autoimmune disease than the normal population (p = 0.015). Men were older than women (Wilcoxon test, p = 0.046) and had less risk of local recurrence (logrank test, p = 0.014). Pregnancy or comorbid conditions did not increase the local recurrence rate. Predictors for local recurrence included location in the distal radius (logrank test, p < 0.001), intralesional treatment (logrank test, p = 0.008) and age less than 40 (logrank test, p = 0.043). In conclusion, giant cell tumour of bone is more common in pregnant females and patients with immune disease. Comorbidities and pregnancy do not affect the local recurrence rate. Male patients over 40 years of age have a lower risk of local recurrence, and patients with disease in the distal radius have a high risk of recurrence
Quasars in the COSMOS Field
We obtained medium-resolution spectra of 336 quasar candidates in the COSMOS
HST/Treasury field using the MMT 6.5-meter telescope and the Hectospec
multi-object spectrograph. Candidates were drawn from the Sloan Digital Sky
Survey (SDSS) DR1 catalog using quasar flags set by the SDSS multi-color quasar
target selection algorithm. In this paper we present our discovery spectra from
1.39 square degrees (69.5% of the COSMOS field) and a discussion of the
selection method and yields. We confirmed 95 quasars, including at least 2
BALs; 80 of these are new quasars that do not appear in previous quasar
confirmation follow-up studies. The candidates additionally included 184
compact emission-line galaxies, a third of which are likely Type 2 AGN, and 12
stars. The quasars span a range in magnitude of 18.3<g<22.5 and a range in
redshift of 0.2<z<2.3. Our results are consistent with a lower limit quasar
surface density from SDSS color selection of 102 per square degree down to
g=22.5 over the entire COSMOS field. This work is the first step toward the
eventual goal of setting up a grid of quasar absorption line probes of the 2
square degree field, and of conducting a complete census of supermassive black
holes in this well-studied survey region. The total quasar count at the
conclusion of this study is 139, making COSMOS one of the most densely-sampled
regions of sky where a grid of quasar sightlines can be used to probe the
intervening volume.Comment: Accepted for publication in ApJ; emulateapj style; 25 pages, 13
figures, 4 table
Identification campaign of supernova remnant candidates in the Milky Way - I: Chandra observation of G308.3-1.4
ROSAT all-sky survey (RASS) data have provided another window to search for
supernova remnants (SNRs). In reexamining this data archive, a list of
unidentified extended X-ray objects have been suggested as promising SNR
candidate. However, most of these targets have not yet been fully explored by
the state-of-art X-ray observatories. For selecting a pilot target for a
long-term identification campaign, we have observed the brightest candidate,
G308.3-1.4, with Chandra X-ray observatory. An incomplete shell-like X-ray
structure which well-correlated with the radio shell emission at 843 MHz has
been revealed. The X-ray spectrum suggests the presence of a shock-heated
plasma. All these evidences confirm G308.3-1.4 as a SNR. The brightest X-ray
point source detected in this field-of-view is also the one locates closest to
the geometrical center of G308.3-1.4, which has a soft spectrum. The intriguing
temporal variability and the identification of optical/infrared counterpart
rule out the possibility of an isolated neutron star. On the other hand, the
spectral energy distribution from Ks band to R band suggests a late-type star.
Together with a putative periodicity of \sim1.4 hrs, the interesting excesses
in V, B bands and H-alpha suggest this source as a promising candidate of a
compact binary survived in a supernova explosion (SN).Comment: 19 pages, 10 figures, 2 tables, accepted for publication in Ap
Triple-Pomeron Matrix Model for Dispersive Corrections to Nucleon-Nucleus Total Cross Section
Dispersive corrections to the total cross section for high-energy scattering
from a heavy nucleus are calculated using a matrix model, based on the
triple-Pomeron behavior of diffractive scattering from a single nucleon, for
the cross section operator connecting different states of the projectile
nucleon . Energy-dependent effects due to the decrease in longitudinal momentum
transfers and the opening of more channels with increasing energy are included.
The three leading terms in an expansion in the number of inelastic transitions
are evaluated and compared to exact results for the model in the uniform
nuclear density approximation for the the scattering of nucleons from Pb^{208}
for laboratory momenta ranging from 50 to 200 GeV/c.Comment: 16 pages, 2 figures, RevTex
Factorization and Scaling in Hadronic Diffraction
In standard Regge theory with a pomeron intercept a(0)=1+\epsilon, the
contribution of the tripe-pomeron amplitude to the t=0 differential cross
section for single diffraction dissociation has the form d\sigma/dM^2(t=0) \sim
s^{2\epsilon}/(M^2)^{1+\epsilon}. For \epsilon>0, this form, which is based on
factorization, does not scale with energy. From an analysis of p-p and p-pbar
data from fixed target to collider energies, we find that such scaling actually
holds, signaling a breakdown of factorization. Phenomenologically, this result
can be obtained from a scaling law in diffraction, which is embedded in the
hypothesis of pomeron flux renormalization introduced to unitarize the triple
pomeron amplitude.Comment: 39 pages, Latex, 16 figure
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