4,574 research outputs found
Polarized Diffuse Emission at 2.3 GHz in a High Galactic Latitude Area
Polarized diffuse emission observations at 2.3 GHz in a high Galactic
latitude area are presented. The 2\degr X 2\degr field, centred in
(\alpha=5^h,\delta=-49\degr), is located in the region observed by the
BOOMERanG experiment. Our observations has been carried out with the Parkes
Radio telescope and represent the highest frequency detection done to date in
low emission areas. Because of a weaker Faraday rotation action, the high
frequency allows an estimate of the Galactic synchrotron contamination of the
Cosmic Microwave Background Polarization (CMBP) that is more reliable than that
done at 1.4 GHz. We find that the angular power spectra of the E- and B-modes
have slopes of \beta_E = -1.46 +/- 0.14 and \beta_B = -1.87 +/- 0.22,
indicating a flattening with respect to 1.4 GHz. Extrapolated up to 32 GHz, the
E-mode spectrum is about 3 orders of magnitude lower than that of the CMBP,
allowing a clean detection even at this frequency. The best improvement
concerns the B-mode, for which our single-dish observations provide the first
estimate of the contamination on angular scales close to the CMBP peak (about 2
degrees). We find that the CMBP B-mode should be stronger than synchrotron
contamination at 90 GHz for models with T/S > 0.01. This low level could move
down to 60-70 GHz the optimal window for CMBP measures.Comment: 5 pages, 6 figures, accepted for publication in MNRAS Letter
Successful small bowel allotransplantation in dogs with cyclosporine and prednisone
Twelve dogs had transplantation of almost the entire small intestine in the orthotopic location; immunosuppression was with cyclosporine and prednisone. Half the dogs had survival of at least one month, and a third lived for at least four months. Two of the animals are still living after 550 and 555 days. Maintenance of nutrition, and absorption of D-xylose and fat were better than in control animals with an iatrogenic short gut syndrome, but distinctly worse than that of normal dogs. © 1984 by The Williams and Wilkins Co
Noise Correlations in a Coulomb Blockaded Quantum Dot
We report measurements of current noise auto- and cross-correlation in a
tunable quantum dot with two or three leads. As the Coulomb blockade is lifted
at finite source-drain bias, the auto-correlation evolves from super-Poissonian
to sub-Poissonian in the two-lead case, and the cross-correlation evolves from
positive to negative in the three-lead case, consistent with transport through
multiple levels. Cross-correlations in the three-lead dot are found to be
proportional to the noise in excess of the Poissonian value in the limit of
weak output tunneling
Active Specific Immunotherapy in the Management of Adenocarcinoma of the Pancreas
Active specific immunotherapy for pancreatic adenocarcinoma and subsequent immunohistochemical analysis of tumour tissue have not been previously reported. To date, the therapy of pancreatic adenocarcinoma has been largely unsuccessful. A patient treated with a therapeutic âcancer vaccineâ and the immunological impact on the primary tumour of this potential new therapy are described. To the authorsâ knowledge, this is both the first patient to be treated with active specific immunotherapy for pancreatic adenocarcinoma and the first to be studied immunologically by flow cytometry and immunohistochemistry with an apparent positive clinical impact
The Galactic Distribution of Large HI Shells
We report the discovery of nineteen new HI shells in the Southern Galactic
Plane Survey (SGPS). These shells, which range in radius from 40 pc to 1 kpc,
were found in the low resolution Parkes portion of the SGPS dataset, covering
Galactic longitudes l=253 deg to l=358 deg. Here we give the properties of
individual shells, including positions, physical dimensions, energetics,
masses, and possible associations. We also examine the distribution of these
shells in the Milky Way and find that several of the shells are located between
the spiral arms of the Galaxy. We offer possible explanations for this effect,
in particular that the density gradient away from spiral arms, combined with
the many generations of sequential star formation required to create large
shells, could lead to a preferential placement of shells on the trailing edges
of spiral arms. Spiral density wave theory is used in order to derive the
magnitude of the density gradient behind spiral arms. We find that the density
gradient away from spiral arms is comparable to that out of the Galactic plane
and therefore suggest that this may lead to exaggerated shell expansion away
from spiral arms and into interarm regions.Comment: 25 pages, 20 embedded EPS figures, uses emulateapj.sty, to appear in
the Astrophysical Journa
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Evaluation of critical congenital heart defects screening using pulse oximetry in the neonatal intensive care unit.
ObjectiveTo evaluate the implementation of early screening for critical congenital heart defects (CCHDs) in the neonatal intensive care unit (NICU) and potential exclusion of sub-populations from universal screening.Study designProspective evaluation of CCHD screening at multiple time intervals was conducted in 21 NICUs across five states (n=4556 infants).ResultsOf the 4120 infants with complete screens, 92% did not have prenatal CHD diagnosis or echocardiography before screening, 72% were not receiving oxygen at 24 to 48âh and 56% were born â©Ÿ2500âg. Thirty-seven infants failed screening (0.9%); none with an unsuspected CCHD. False positive rates were low for infants not receiving oxygen (0.5%) and those screened after weaning (0.6%), yet higher among infants born at <28 weeks (3.8%). Unnecessary echocardiograms were minimal (0.2%).ConclusionGiven the majority of NICU infants were â©Ÿ2500âg, not on oxygen and not preidentified for CCHD, systematic screening at 24 to 48âh may be of benefit for early detection of CCHD with minimal burden
Chemical Measurement and Fluctuation Scaling
Main abstract:
Fluctuation scaling reports on all processes producing a data set. Some fluctuation scaling relationships, such as the Horwitz curve, follow exponential dispersion models which have useful properties. The mean-variance method applied to Poisson distributed data is a special case of these properties allowing the gain of a system to be
measured. Here, a general method is described for investigating gain (G), dispersion (ÎČ), and process (α) in any system whose fluctuation scaling follows a simple exponential dispersion model, a segmented exponential dispersion model, or complex scaling following such a model locally. When gain and dispersion cannot be obtained directly, relative parameters, GR and ÎČR, may be used.
The method was demonstrated on data sets conforming to simple, segmented, and complex scaling. These included mass, fluorescence intensity, and absorbance measurements and specifications for classes of calibration weights.
Changes in gain, dispersion, and process were observed in the scaling of these data sets in response to instrument parameters, photon fluxes, mathematical processing, and calibration weight class. The process parameter which limits the type of statistical process that can be invoked to explain a data set typically exhibited 04 possible. With two exceptions, calibration weight class definitions only affected ÎČ. Adjusting photomultiplier voltage while measuring fluorescence intensity changed all three parameters (0<α<0.8; 0<ÎČR<3; 0<GR<4.1). The method provides a framework for calibrating and interpreting uncertainty in chemical measurement allowing robust compar ison of specific instruments, conditions, and methods.
Supporting information abstract:
On first inspection, fluctuation scaling data may appear to approximate a straight line when log transformed. The data presented in figure 5 of the main text gives a reasonable approximation to a straight line and for many purposes this would be sufficient. The purpose of the study of fluorescence intensity was to determine whether adjusting the voltage of a photomultiplier tube while measuring a fluorescent sample changes the process (α), the dispersion (ÎČ) and/or the gain (G). In this regard, the linear model established that PMT setting affects more than the gain. However, a detailed analysis beginning with testing for model mis-specification provides additional information. Specifically, Poisson behavior is only seen over a limited wavelength range in the 600 V and 700 V data sets
Collecting genetic material from beef cattle (2005)
The beef cattle industry has long awaited the development of genetic tests to assist producers in breeding selection and management and to improve the marketability of cattle. Currently, there are only a handful of genetic tests commercially available for beef cattle. Beef producers interested in using genetic testing to improve their breeding stock need to know how to collect and store various genetic materials for testing.New February 2005 -- Extension website
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