3,643 research outputs found
A Comparison Study of Quality Attributes of Ground Beef and Veal Patties and Thermal Inactivation of Escherichia coli O157:H7 after Double Pan-Broiling Under Dynamic Conditions
This study compared the quality variation and thermal inactivation of Escherichia coli O157:H7 in non-intact beef and veal. Coarse ground beef and veal patties (2.1 cm thick, 12.4 cm diameter, 180 g) inoculated with E. coli O157:H7, aerobically stored before double pan-broiling for 0–360 s without rest or to 55, 62.5, 71.1, and 76 ◦C (internal temperature) with 0.5- or 3.5-min rest. Microbial population and qualities including color, cooking losses, pH, water activity, fat, and moisture content, were tested. After cooking the beef and veal patties, the weight losses were 17.83–29%, the pH increased from 5.53–5.60 to 5.74–6.09, the moisture content decreased from 70.53–76.02% to 62.60–67.07%, and the fat content increased (p \u3c 0.05) from 2.19–6.46% to 2.92–9.45%. Cooking beef and veal samples with increasing internal temperatures decreased a* and b* values and increased the L* value. Escherichia coli O157:H7 was more sensitive to heat in veal compared to beef with shorter D-value and “shoulder” time. Cooking to 71.1 and 76 ◦C reduced E. coli O157:H7 by \u3e6 log CFU/g regardless of rest time. Cooking to 55 ◦C and 62.5 ◦C with a 3.5-min rest achieved an additional 1–3 log CFU/g reduction compared to the 0.5-min rest. Results should be useful for developing risk assessment of non-intact beef and veal products
The Future of the Colorado River Delta
Includes map of the Colorado River Delt
Measurement of the Mass and Stellar Population Distribution in M82 with the LBT
We present a K-band spectroscopic study of the stellar and gas kinematics,
mass distribution, and stellar populations of the archetypical starburst galaxy
M82. Our results are based on a single spectrum at a position angle of 67.5
degrees through the K-band nucleus. We used the CO stellar absorption band head
at 2.29 {\mu}m (CO_2.29) to measure the rotation curve out to nearly 4 kpc
radius on both the eastern and western sides of the galaxy. Our data show that
the rotation curve is flat from 1 - 4 kpc. This stands in sharp contrast to
some previous studies, which have interpreted H I and CO emission-line
position-velocity diagrams as evidence for a declining rotation curve. The
kinematics of the Br\gamma, H_2, and He I emission lines are consistent with,
although characterized by slightly higher velocities than, the stellar
kinematics. We derived M82's mass distribution from our stellar kinematic
measurements and estimate its total dynamical mass is ~10^10 Msun. We measured
the equivalent width of CO_2.29 (W_2.29) as a function of distance from the
center of the galaxy to investigate the spatial extent of the red supergiant
(RSG) population. The variation in W_2.29 with radius clearly shows that RSGs
dominate the light inside 500 pc radius. M82's superwind is likely launched
from this region, where we estimate the enclosed mass is <= 2 x 10^9 Msun.Comment: 6 pages, 6 figures. Submitted to ApJ. For a brief video explaining
the key result of this paper, see http://www.youtube.com/user/OSUAstronom
VLA H92 Alpha and H53 Alpha Radio Recombination Line Observations of M82
We present high angular resolution (0.6'') observations made with the VLA of
the radio continuum at 8.3 and 43 GHz as well as H92 Alpha and H53 Alpha radio
recombination lines from the nearby (3 Mpc) starburst galaxy M82. In the
continuum we report 19 newly identified sources at 8.3 GHz and 5 at 43 GHz that
were unknown previously. The spatial distribution of the H92 Alpha line is
inhomogeneous; we identify 27 features. The line and continuum emission are
modeled using a collection of HII regions at different distances from the
nucleus assuming a single-density component and two-density components. The
high-density component has a density of 4 X 10^{4} cm^{-3}. However, the bulk
of the ionization is in regions with densities which are typically a factor 10
lower. The gas kinematics, using the H92 Alpha line, confirms the presence of
steep velocity gradient (26 km s^{-1} arcsec^{-1}) in the nuclear region. As
this steep gradient is observed not only on the major axis but also at large
distances along a band of PA of 150 degrees, the interpretation in terms of x2
orbits elongated along the minor axis of the bar, which would be observed at an
angle close to the inclination of the main disk, seems inadequate. Ad-hoc
radial motions must be introduced to reproduce the pattern of the velocity
field. Different families of orbits are indicated as we detect a signature in
the kinematics at the transition between the two plateaus observed in the NIR
light distribution. The H92 Alpha line also reveals the base of the outflow
where the injection towards the halo on the Northern side occurs. The
kinematical pattern suggests a connection between the gas flowing in the plane
of M82 towards the center; this behavior most likely originates due to the
presence of a bar and the outflow out of the plane.Comment: 45 pages, 11 figures and 6 tables. Accepted for publication in Ap
The Kinematics of the Ionized and Molecular Hydrogen in the Starburst Galaxy NGC 253
Near-infrared H_2 1-0 S(1) and Br_gamma velocity curves along the major axis
of NGC 253 have revealed a central velocity gradient that is seven times
steeper than that shown by the optical velocity curve. This is interpreted as
an optical depth effect due to dust. Approximately 35 mag of visual extinction
in the center is required to match the SW side of the optical velocity curve.
The spatial variation of the ratio of these lines to the CO (J=1-0) line is
compared among starburst galaxies NGC 253, M82, and NGC 4945 to investigate the
excitation mechanism responsible for the H_2 1-0 S(1) line.Comment: Uuencoded postscript file, 10 pages (4 tables included), 8 figures
available on request to [email protected], Ap.J. (in press
SLIDES: So What if It’s Called “All-American”
Presenter: Melissa Hathaway McKeith, Lewis Brisbois Bisgaard & Smith LLP.
Respondent on US-Mexico Issues and Other Lower Basin Matters: Bob Johnson, US Bureau of Reclamation.
15 slides and 12 pages.
Contains references
SLIDES: So What if It’s Called “All-American”
Presenter: Malissa Hathaway McKeith, Lewis Brisbois Bisgaard & Smith LLP.
Respondent on US-Mexico Issues and Other Lower Basin Matters: Bob Johnson, US Bureau of Reclamation.
15 slides and 12 pages.
Contains references
Discovery of Molecular Gas in the Outflow and Tidal Arms around M82
We present the first fully sampled map of 12CO (1-0) emission from M82
covering the entire galaxy. Our map contains a 12 x 15 kpc^2 area. We find that
extraplanar CO emission, previously reported at short distances above the
galactic plane, extends to heights of up to 6 kpc above the disk. Some of this
emission is associated with tidal arms seen in HI, implying either that M82
contained substantial amounts of molecular gas in the outer disk, or that
molecular gas formed after the tidal features. CO emission along the direction
of the outflow extends to distances of 3 kpc above and below the disk. At this
distance, the line is shifted in velocity about 100 km/s, and has the same
sense as the galactic outflow from the central starburst. This implies that
molecular gas may be entrained into the outflow.Comment: 4 pages, 6 figures. Uses emulateapj5. Accepted by ApJ Letter
Differentiation of dementia with Lewy bodies from Alzheimer's disease using a dopaminergic presynaptic ligand
Background: Dementia with Lewy bodies (DLB) is one of the main differential diagnoses of Alzheimer's disease (AD). Key pathological features of patients with DLB are not only the presence of cerebral cortical neuronal loss, with Lewy bodies in surviving neurones, but also loss of nigrostriatal dopaminergic neurones, similar to that of Parkinson's disease (PD). In DLB there is 40-70% loss of striatal dopamine.Objective: To determine if detection of this dopaminergic degeneration can help to distinguish DLB from AD during life.Methods: The integrity of the nigrostriatal metabolism in 27 patients with DLB, 17 with AD, 19 drug naive patients with PD, and 16 controls was assessed using a dopaminergic presynaptic ligand, I-123-labelled 2beta-carbomethoxy-3beta-(4-iodophenyl)-N-(3-fluoropropyl)nortropane (FP-CIT), and single photon emission tomography (SPET). A SPET scan was carried out with a single slice, brain dedicated tomograph (SME 810) 3.5 hours after intravenous injection of 185 MBq FP-CIT. With occipital cortex used as a radioactivity uptake reference, ratios for the caudate nucleus and the anterior and posterior putamen of both hemispheres were calculated. All scans were also rated by a simple visual method.Results: Both DLB and PD patients had significantly lower uptake of radioactivity than patients with (p<0.01) and controls (p<0.001) in the caudate nucleus and the anterior and posterior Putamen.Conclusion: FP-CIT SPET provides a means of distinguishing DLB from AD during life
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