1,916 research outputs found
Differential immunological response detected in mRNA expression profiles among diverse chicken lines in response to Salmonella challenge
Salmonella enterica serovar Enteritidis is a bacterial pathogen that contributes to poultry production losses and human foodborne illness. The bacterium elicits a broad immune response involving both the innate and adaptive components of the immune system. Coordination of the immune response is largely directed by cytokines. The objective of the current study was to characterize the expression of a select set of cytokines and regulatory immune genes in three genetically diverse chicken lines after infection with S. Enteritidis. Leghorn, Fayoumi and broiler day-old chicks were orally infected with pathogenic S. Enteritidis or culture medium. At 2 and 18 h postinfection, spleens and ceca were collected and mRNA expression levels for 7 genes (GM-CSF, IL2, IL15, TGF-β1, SOCS3, P20K, and MHC class IIβ) were evaluated by real-time quantitative PCR. Genetic line had a significant effect on mRNA expression levels of IL15, TGF-β1, SOCS3 and P20K in the spleen and on P20K and MHC class IIβ in the cecum. Comparing challenged vs. unchallenged birds, the expression of SOCS3 and P20K mRNA were significantly higher in the spleen and cecum, while MHC class IIβ mRNA was significantly lower in spleen. Combining the current RNA expression results with those of previously reported studies on the same samples reveals distinct RNA expression profiles among the three genetic chicken lines and the 2 tissues. This study illustrates that these diverse genetic lines have distinctively different immune response to S. Enteritidis challenge within the spleen and the cecum
Galaxy-Galaxy Lensing in the Hubble Deep Field: The Halo Tully-Fisher Relation at Intermediate Redshift
A tangential distortion of background source galaxies around foreground lens
galaxies in the Hubble Deep Field is detected at the 99.3% confidence level. An
important element of our analysis is the use of photometric redshifts to
determine distances of lens and source galaxies and rest-frame B-band
luminosities of the lens galaxies. The lens galaxy halos obey a Tully-Fisher
relation between halo circular velocity and luminosity; the typical lens
galaxy, at a redshift z = 0.6, has a circular velocity of 210 +/-40 km/s at M_B
= -18.5, if q_0 = 0.5. Control tests, in which lens and source positions and
source ellipticities are randomized, confirm the significance level of the
detection quoted above. Furthermore, a marginal signal is also detected from an
independent, fainter sample of source galaxies without photometric redshifts.
Potential systematic effects, such as contamination by aligned satellite
galaxies, the distortion of source shapes by the light of the foreground
galaxies, PSF anisotropies, and contributions from mass distributed on the
scale of galaxy groups are shown to be negligible. A comparison of our result
with the local Tully-Fisher relation indicates that intermediate-redshift
galaxies are fainter than local spirals by 1.0 +/- 0.6 B mag at a fixed
circular velocity. This is consistent with some spectroscopic studies of the
rotation curves of intermediate-redshift galaxies. This result suggests that
the strong increase in the global luminosity density with redshift is dominated
by evolution in the galaxy number density.Comment: Revised version with minor changes. 13 pages, 7 figures, LaTeX2e,
uses emulateapj and multicol styles (included). Accepted by Ap
Chicken Antibody Response to Salmonella enteritidis Vaccine in Advanced Intercross Lines and Parental Lines
In five pure genetic lines of chickens, along with the Iowa Salmonella Response Resource Population (ISRRP) AIL-F13 generation, antibody levels to an antiSalmonella vaccine were measured as an estimate of early immune response to bacterial infections. Knowledge of the early immune response and its genetic control factors may aid in understanding host-pathogen interactions and, therefore, improve vaccine development strategies. Using vaccines in poultry facilitates control and reduces the prevalence of bacterial infections in animals and humans
Rotational and Translational Components of Motion Parallax: Observers' Sensitivity and Implications for Three-Dimensional Computer Graphics
The motion of objects during motion parallax can be decomposed into 2 observer-relative components: translation and rotation. The depth ratio of objects in the visual field is specified by the inverse ratio of their angular displacement (from translation) or equivalently by the inverse ratio of their rotations. Despite the equal mathematical status of these 2 information sources, it was predicted that observers would be far more sensitive to the translational than rotational component. Such a differential sensitivity is implicitly assumed by the computer graphics technique billboarding, in which 3-dimensional (3-D) objects are drawn as planar forms (i.e., billboards) maintained normal to the line of sight. In 3 experiments, observers were found to be consistently less sensitive to rotational anomalies. The implications of these findings for kinetic depth effect displays and billboarding techniques are discussed
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