5,365 research outputs found
Clinical Applications of Prostaglandins in Dogs and Cats
In the biological sciences today there are few substances that generate as much interest as prostaglandins. They have found widespread use in veterinary medicine, yet are only approved by the FDA for specific uses in cattle and horses. However, practical applications in the dog and cat have been reported by clinicians and have been evaluated in clinical research projects
Heifer Spay
Spaying heifers dates back to the 1850\u27s when it was used to prolong the productivity of milking cows. These cows were spayed at 30 to 40 days after calving or before they came into estrus. This would prolong the milking period of these older cows for two to three years. The cows would also fatten faster on high energy feed for slaughter
A strong maximum principle for reaction-diffusion systems and a weak convergence scheme for reflected stochastic differential equations by Lawrence Christopher Evans.
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mathematics, 2010.Cataloged from PDF version of thesis.Includes bibliographical references (p. 125-126).This thesis consists of two results. The first result is a strong maximum principle for certain parabolic systems of equations, which, for illustrative purposes, I consider as reaction-diffusion systems. Using the theory of viscosity solutions, I give a proof which extends the previous theorem to no longer require any regularity assumptions on the boundary of the convex set in which the system takes its values. The second result is an approximation scheme for reflected stochastic differential equations (SDE) of the Stratonovich type. This is a joint result with Professor Daniel W. Stroock. We show that the distribution of the solution to such a reflected SDE is the weak limit of the distribution of the solutions of the reflected SDEs one gets by replacing the driving Brownian motion by its N-dyadic linear interpolation. In particular, we can infer geometric properties of the solutions to a Stratonovich reflected SDE from those of the solutions to the approximating reflected SDE.Ph.D
Lymphocytic Hypophysitis
A 59 year-old female presented with visual problems in 2006, and was initially diagnosed with a pituitary macroadenoma on MRI (Figure 1). Preoperatively, the pituitary lesion decreased in size after the patient was started on steroids, raising the possibility of lymphoma and inflammatory conditions. Ultimately, endoscopic trans-nasal biopsy of the pituitary lesion revealed lymphocytic hypophysitis. She was treated with steroids for two years and developed several side effects from chronic steroid use, including Cushingoid features, diabetes, cataracts, weight-gain and osteopenia. As a result, she was subsequently treated with methotrexate and gradual weaning of the steroids
The gravitationally lensed, luminous infrared galaxy IRAS F10214+4724 observed with XMM-Newton
We report on a short XMM-Newton observation of the gravitationally-lensed,
luminous infrared galaxy IRAS F10214+4724 at z=2.3. A faint X-ray source is
detected at 4 sigma. The observed 0.5-2 keV (1.7-6.6 keV in the rest-frame)
flux is 1.3e-15 erg/s/cm2 and the spectral slope in the rest-frame 1-10 keV
band is Gamma~2. These results agree with those obtained from the Chandra X-ray
Observatory, given the large uncertainties in both measurements. While possible
evidence for excess emission above 5 keV is seen, we suspect this excess might
be either spurious or not related to the infrared galaxy.Comment: 4 pages, 2 figures, New Astronomy in pres
Observed Effect of Magnetic Fields on the Propagation of Magnetoacoustic Waves in the Lower Solar Atmosphere
We study Hinode/SOT-FG observations of intensity fluctuations in Ca II H-line
and G-band image sequences and their relation to simultaneous and co-spatial
magnetic field measurements. We explore the G-band and H-line intensity
oscillation spectra both separately and comparatively via their relative phase
differences, time delays and cross-coherences. In the non-magnetic situations,
both sets of fluctuations show strong oscillatory power in the 3 - 7 mHz band
centered at 4.5 mHz, but this is suppressed as magnetic field increases. A
relative phase analysis gives a time delay of H-line after G-band of 20\pm1 s
in non-magnetic situations implying a mean effective height difference of 140
km. The maximum coherence is at 4 - 7 mHz. Under strong magnetic influence the
measured delay time shrinks to 11 s with the peak coherence near 4 mHz. A
second coherence maximum appears between 7.5 - 10 mHz. Investigation of the
locations of this doubled-frequency coherence locates it in diffuse rings
outside photospheric magnetic structures. Some possible interpretations of
these results are offered.Comment: 19 pages, 6 figure
New Near-Infrared Spectroscopy of the High Redshift Quasar B 1422+231 at z=3.62
We present new near-infrared (rest-frame UV-to-optical) spectra of the high
redshift, gravitationally lensed quasar B 1422+231 (z=3.62). Diagnostic
emission lines of FeII, [OIII]5007, and Hb, commonly used to determine the
excitation, ionization, and chemical abundances of radio-quiet and radio-loud
quasars, were detected. Our new data show that the ratio FeII(UV)/Hb=18.1+-4.6
and FeII(optical)/Hb=2.3+-0.6 are higher than those reported by Kawara et al.
(1996) by factors of 1.6 and 3.3, respectively, although the ration
[OIII]5007/Hb=0.19+-0.02 is nearly the same between the two measurements. The
discrepancy of the line flux ratios between the measurements is likely due to
improved data and fitting procedures rather that to intrinsic variability.
While approximately half of the high-z quasars observed to date have much more
extreme FeII(optical)/Hb ratios, the line ratio measured for B 422+231 are
consistent with the observed range of FeII(optical) ratios of low-z quasars.Comment: 5 pages, 1 table, 4 figures. To appear in The Astronomical Journa
Identification of Vehicle Health Assurance Related Trends
Trend analysis in aviation as related to vehicle health management (VHM) was performed by reviewing the most current statistical and prognostics data available from the National Transportation Safety Board (NTSB) accident, the Federal Aviation Administration (FAA) incident, and the NASA Aviation Safety Reporting System (ASRS) incident datasets. In addition, future directions in aviation technology related to VHM research areas were assessed through the Commercial Aviation Safety Team (CAST) Safety Enhancements Reserved for Future Implementations (SERFIs), the National Transportation Safety Board (NTSB) Most-Wanted List and recent open safety recommendations, the National Research Council (NRC) Decadal Survey of Civil Aeronautics, and the Future Aviation Safety Team (FAST) areas of change. Future research direction in the VHM research areas is evidently strong as seen from recent research solicitations from the Naval Air Systems Command (NAVAIR), and VHM-related technologies actively being developed by aviation industry leaders, including GE, Boeing, Airbus, and UTC Aerospace Systems. Given the highly complex VHM systems, modifications can be made in the future so that the Vehicle Systems Safety Technology Project (VSST) technical challenges address inadequate maintenance crew's trainings and skills, and the certification methods of such systems as recommended by the NTSB, NRC, and FAST areas of change
The Arecibo Arp 220 Spectral Census I: Discovery of the Pre-Biotic Molecule Methanimine and New Cm-wavelength Transitions of Other Molecules
An on-going Arecibo line search between 1.1 and 10 GHz of the prototypical
starburst/megamaser galaxy, Arp 220, has revealed a spectrum rich in molecular
transitions. These include the ``pre-biotic'' molecules: methanimine
(CHNH) in emission, three direct l-type absorption lines of
HCN, and an absorption feature likely to be from either OH or formic
acid (HCOOH). In addition, we report the detection of two, possibly three,
transitions of 4-cm excited OH not previously detected in Arp~220
which are seen in absorption, and a possible absorption feature from the
6.668-GHz line of methanol. This marks the first distant extragalactic
detection of methanimine, a pre-biotic molecule. Also, if confirmed, the
possible methanol absorption line presented here would represent the first
extragalactic detection of methanol at a distance further than 10 Mpc. In
addition, the strong, previously undetected, cm-wave HCN direct
l-type lines will aid the study of dense molecular gas and active star-forming
regions in this starburst galaxy.Comment: 25 pages, 10 figures. Accepted for publication in A
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