67 research outputs found
Perceptions of on-farm emergency slaughter for dairy cows in British Columbia
Some jurisdictions permit on-farm emergency slaughter (OFES) as one end-of-life option for dairy cows and other animals that cannot be transported humanely but are deemed fit for human consumption. Anecdotal reports suggest that OFES is controversial among dairy industry professionals, but to date their perceptions of OFES have not been studied systematically. Twentyfive individual interviews and 3 focus groups with 40 dairy producers, veterinarians, and other professionals in British Columbia, Canada, revealed positive and negative perceptions of OFES influenced by (1) individual values, (2) the perceived operational legitimacy of OFES, and (3) concern over social responsibility and public perception of the dairy industry. Study participants valued cow welfare but were divided on whether OFES quickened or delayed death for injured animals. Views on the operational legitimacy of OFES varied because of different perceptions and concerns regarding regulatory, veterinary, and meat inspector oversight, a possible conflict of interest for veterinarians, and concerns over carcass hygiene and transport. Whereas many appreciated that OFES prevented transport of compromised cows, others saw OFES as merely a stopgap measure. Seven recommended actions could address concerns while retaining the benefits of OFES: (1) specifying precise timing parameters for OFES, (2) clarification of allowable cow conditions for OFES, (3) consultation with dairy industry professionals if OFES is to be expanded, (4) more proactive culling and the development of euthanasia protocols on farms, (5) the designation of veterinarians as the first point of contact in the OFES process, (6) veterinarian training on animal inspection and allowable conditions for OFES, and (7) the use of proper procedures and equipment during the OFES process to ensure food safety
Use of on-farm emergency slaughter for dairy cows in British Columbia
On-farm emergency slaughter (OFES), whereby inspection, stunning, and bleeding occur on the farm before the carcass is transported to a slaughterhouse, is permitted in some jurisdictions as a means to avoid inhumane transportation while salvaging meat from injured animals. However, OFES is controversial and its use for dairy cows has been little studied. Inspection documents for 812 dairy cows were examined to identify how OFES was used for dairy cows in British Columbia, Canada, over 16.5 mo. Producers used OFES for dairy cows aged 1 to 13 yr (median of 4 yr). Leg, hip, nerve, spinal, foot, and hind-end injuries or conditions (in that order) were the most common reasons for OFES, and some cases may have been a consequence of calv-ing. Foot conditions were disproportionately common among cows 5 yr and older, and hind-end conditions were disproportionately common among cows 6 yr and older. Producers used OFES promptly after traumatic injury (within 1 d) for some cows, but OFES was de-layed for others, sometimes until cows had been nonam-bulatory for 2 to 6 d. In some cases, OFES was used for nontraumatic chronic conditions, such as lameness and hind-end weakness, rather than traumatic injuries such as fractures and dislocated hips. Use of OFES appears to conform to the purpose of the program when used promptly after traumatic injuries, but clear guidelines are needed to avoid inappropriate use and delays that may prolong animal suffering
The Slow X-Ray Expansion of the Northwestern Rim of the Supernova Remnant RX J0852.0-4622
The detection of radioactive decay line of 44Ti provides a unique evidence
that the gamma-ray source is a young (< 1,000 yr) supernova remnant because of
its short lifetime of about 90 yr. Only two Galactic remnants, Cassiopeia A and
RX J0852.0-4622, are hitherto reported to be the 44Ti line emitter, although
the detection from the latter has been debated. Here we report on an expansion
measurement of the northwestern rim of RX J0852.0-4622 obtained with X-ray
observations separated by 6.5 yr. The expansion rate is derived to be
0.023+/-0.006% that is about five times lower than those of young historical
remnants. Such a slow expansion suggests that RX J0852.0-4622 is not a young
remnant as has been expected. We estimate the age of 1,700-4,300 yr of this
remnant depending on its evolutionary stage. Assuming a high shock speed of
about 3000 km/sec, which is suggested by the detection of non-thermal X-ray
radiation, the distance of about 750 pc to this remnant is also derived.Comment: 12 pages, 3 figures, Accepted for publication in the Astrophysical
Journal Letter
Google Apps (and other Google Tools) for Libraries
Using a mix of demonstration, hands-on experience and conversation, participants will dig deeper into Google and Google Apps. You may want to bring your lab coat. Macalester has been using Google Apps for nearly a year, and will share some experiences as well as ways we have been integrating / leveraging Google into the day-to-day life of our library and institution. We want to know how others are using Google, and hope to develop a shared best practices project as one outcome of this session
Chandra Detection of the Forward and Reverse Shocks in Cassiopeia-A
We report the localization of the forward and reversed shock fronts in the
young supernova remnant Cas-A using X-ray data obtained with the Chandra
Observatory. High resolution X-ray maps resolve a previously unseen X-ray
feature encompassing the extremity of the remnant. This feature consists of
thin, tangential wisps of emission bordering the outer edge of the thermal
X-ray and radio remnant, forming a circular rim, approx. 2.7 in radius. Radio
images show a sharp rise in brightness at this X-ray rim, along with a large
jump in the synchrotron polarization angle. These characteristics suggest that
these wisps are the previously unresolved signature of the forward, or outer,
shock. Similarly, we identify the sharp rise in emissivity of the bright shell
for both the radio and X-ray line emission associated with the reverse shock.
The derived ratio of the averaged forward and reverse shock radii of approx.
3:2 constrains the remnant to have swept up roughly the same amount of mass as
was ejected; this suggests that Cas-A is just entering the Sedov phase.
Comparison of the X-ray spectra from the two shock regions shows that the
equivalent widths of prominent emission lines are significantly lower exterior
to the bright shell, as expected if they are respectively identified with the
shocked circumstellar material and shocked ejecta. Furthermore, the spectrum of
the outer rim itself is dominated by power-law emission, likely the counterpart
of the non-thermal component previously seen at energies above 10 keV.Comment: 7 pages with 5 figures, LaTex, emulateapj.sty. To appear in the
Astrophysical Journal Letter
Discovery of New Interacting Supernova Remnants in the Inner Galaxy
OH(1720 MHz) masers are excellent signposts of interaction between supernova
remnants(SNRs) and molecular clouds. Using the GBT and VLA we have surveyed 75
SNRs and six candidates for maser emission. Four new interacting SNRs are
detected with OH masers: G5.4-1.2, G5.7-0.0, G8.7-0.1 and G9.7-0.0. The newly
detected interacting SNRs G5.7-0.0 and G8.7-0.1 have TeV gamma-ray counterparts
which may indicate a local cosmic ray enhancement. It has been noted that
maser-emitting SNRs are preferentially distributed in the Molecular Ring and
Nuclear Disk. We use the present and existing surveys to demonstrate that
masers are strongly confined to within 50 degrees Galactic longitude at a rate
of 15 percent of the total SNR population. All new detections are within 10
degrees Galactic longitude emphasizing this trend. Additionally, a substantial
number of SNR masers have peak fluxes at or below the detection threshold of
existing surveys. This calls into question whether maser surveys of Galactic
SNRs can be considered complete and how many maser-emitting remnants remain to
be detected in the Galaxy.Comment: Accepted to ApJ Letters, with 2 figures and 2 table
Did Egret Detect Distant Supernova Remnants?
It might be thought that supernova remnants (SNRs) more distant than a few
kiloparsec from Earth could not have been detected by the EGRET experiment.
This work analyzes the observational status of this statement in the light of
new CO studies of SNRs.Comment: Accepted for publication in Advances in Space Research, in High
Energy Studies of Supernova Remnants and Neutron Stars, eds. W. Becker and W.
Hermsen (2003
Spitzer Observations of Molecular Hydrogen in Interacting Supernova Remnants
With Spitzer IRS we have obtained sensitive low-resolution spectroscopy from
5 to 35 microns for six supernova remnants (SNRs) that show evidence of shocked
molecular gas: Kes 69, 3C 396, Kes 17, G346.6-0.2, G348.5-0.0 and G349.7+0.2.
Bright, pure-rotational lines of molecular hydrogen are detected at the shock
front in all remnants, indicative of radiative cooling from shocks interacting
with dense clouds. We find the excitation of H2 S(0)-S(7) lines in these SNRs
requires two non-dissociative shock components: a slow, 10 km/s C- shock
through clumps of density 10^6 cm^-3, and a faster, 40-70 km/s C- shock through
a medium of density 10^4 cm^-3. The ortho-to-para ratio for molecular hydrogen
in the warm shocked gas is typically found to be much less than the LTE value,
suggesting that these SNRs are propagating into cold quiescent clouds.
Additionally a total of thirteen atomic fine-structure transitions of Ar+,
Ar++, Fe+, Ne+, Ne++, S++, and Si+ are detected. The ionic emitting regions are
spatially segregated from the molecular emitting regions within the IRS slits.
The presence of ionic lines with high appearance potential requires the
presence of much faster, dissociative shocks through a lower density medium.
The IRS slits are sufficiently wide to include regions outside the SNR which
permits emission from diffuse gas around the remnants to be separated from the
shocked emission. We find the diffuse molecular hydrogen gas projected outside
the SNR is excited to a temperature of 100 to 300 K with a warm gas fraction of
0.5 to 15 percent along the line of sight.Comment: Accepted to Ap J and scheduled for 2009 April 1 v694 issue. LaTeX, 27
pages with 11 figure
Suzaku Observations of Ejecta-Dominated Galactic Supernova Remnant G346.6-0.2
We present here the results of the X-ray analysis of Galactic supernova
remnant G346.6-0.2 observed with {\it Suzaku}. K-shell emission lines of Mg,
Si, S, Ca and Fe are detected clearly for the first time. Strong emission lines
of Si and S imply that X-ray emission nature of G346.6-0.2 is ejecta-dominated.
The ejecta-dominated emission is well fitted with a combined model consisting
of thermal plasma in non-equilibrium ionization and a non-thermal component,
which can be regarded as synchrotron emission with a photon index of
. Absorbing column density of is obtained from the best-fitting implying a high-density medium,
high electron temperature of keV, and ionization timescale
of indicating that this
remnant may be far from full ionization equilibrium. The relative abundances
from the ejecta show that the remnant originates from a Type Ia supernova
explosion.Comment: 7 pages, 4 figur
- …