Coaxial Jets and Sheaths in Wide-Angle-Tail Radio Galaxies

We add 20, 6 and 3.6 cm wavelength VLA observations of two WATs, 1231+674 and 1433+553, to existing VLA data at 6 and 20 cm, in order to study the variations of spectral index as a function of position. We apply the spectral tomography process that we introduced in our analysis of 3C67, 3C190 and 3C449. Both spectral tomography and polarization maps indicate that there are two distinct extended components in each source. As in the case of 3C449, we find that each source has a flat spectrum jet surrounded by a steeper spectrum sheath. The steep components tend to be more highly polarized than the flat components. We discuss a number of possibilities for the dynamics of the jet/sheath systems, and the evolution of their relativistic electron populations. While the exact nature of these two coaxial components is still uncertain, their existence requires new models of jets in FR I sources and may also have implications for the dichotomy between FR Is and FR IIs.Comment: 29 text pages plus 13 figures. Scheduled for publication in May 10, 1999 Ap

Historical Comparison of Perfluorooctanesulfonate, Perfluorooctanoate, and Other Fluorochemicals in Human Blood

The purpose of this investigation was to determine whether there has been a change in the human blood concentration of perfluorooctanesulfonate (PFOS), perfluorooctanoate (PFOA), and five other fluorochemicals since 1974. Blood samples were collected in 1974 (serum) and 1989 (plasma) from volunteer participants of a large community health study. The study included a total of 356 samples (178 from each time period). These samples were analyzed by high-pressure liquid chromatography/tandem mass spectrometry methods. The median 1974 and 1989 fluorochemical concentrations, respectively, were as follows: PFOS, 29.5 ng/mL vs. 34.7 ng/mL; PFOA, 2.3 ng/mL vs. 5.6 ng/mL; perfluorohexanesulfonate (PFHS), 1.6 ng/mL vs. 2.4 ng/mL; and N-ethyl perfluorooctanesulfonamidoacetate (PFOSAA), less than the lower limit of quantitation (LLOQ; 1.6 ng/mL, vs. 3.4 ng/mL). For N-methyl perfluorooctanesulfonamidoacetate (M570), perfluorooctanesulfonamide, and perfluorooctanesulfonamidoacetate, median serum concentrations in both years were less than the LLOQ values (1.0, 1.0, and 2.5 ng/mL, respectively). Statistical analysis of 58 paired samples indicated that serum concentrations of PFOS, PFOSAA, PFOA, PFHS, and M570 were significantly (p < 0.001) higher in 1989 than in 1974. The data from 1989 were then compared with geometric mean fluorochemical concentrations of serum samples collected in 2001 from 108 American Red Cross adult blood donors from the same region. Except for M570, there were no statistically significant (p < 0.05) geometric mean fluorochemical concentration differences between the 1989 and 2001 samples. In conclusion, based on this study population, PFOS and other serum fluorochemical concentrations have increased between 1974 and 1989. Comparison with other regional data collected in 2001 did not suggest a continued increase in concentrations since 1989

Trans-Activation of PPARa and induction of PPARa target genes by perfluorooctane-based chemicals

Peroxisome proliferator-activated receptors (PPARs) are liganddependent transcription factors that activate target genes involved in lipid metabolism, energy homeostasis, and cell differentiation in response to diverse compounds, including environmental chemicals. The liver-expressed receptor PPARa mediates peroxisome proliferative responses associated with rodent hepatocarcinogenesis. Previous studies have established that certain perfluorooctanesulfonamide-based chemicals (PFOSAs) alter lipid metabolism, are hepatic peroxisome proliferators, and induce hepatocellular adenoma formation in rodents, suggesting that they activate PPARa. The present study investigates this question and characterizes the activation of mouse and human PPARa by PFOSAs. Perfluorooctanesulfonate (PFOS), an end-stage metabolite common to several PFOSAs, was found to activate both mouse and human PPARa in a COS-1 cell-based luciferase reporter trans-activation assay. Halfmaximal activation (EC 50 ) occurred at 13-15 mM PFOS, with no significant difference in the responsiveness of mouse and human PPARa. Mouse and human PPARa were activated by perfluorooctanesulfonamide (FOSA) over a similar concentration range; however, cellular toxicity precluded an accurate determination of EC 50 values. Studies of 2-N-ethylperfluorooctanesulfonamido ethanol were less informative due to its insolubility. These findings were verified in an FAO rat hepatoma cell line that stably expresses PPARa, where the endogenous PPARa target genes peroxisomal bifunctional enzyme and peroxisomal 3-ketoacyl-CoA thiolase were activated up to $10-20-fold by PFOS and FOSA. The interactions of PPARa with PFOS and FOSA, and the potential of these chemicals for activation of unique sets of downstream target genes, may help explain the diverse biological effects exhibited by PFOSAs and may aid in the evaluation of human and environmental risks associated with exposure to this important class of fluorochemicals

Identification of quantitative trait loci associated with iron deficiency chlorosis resistance in groundnut ( Arachis hypogaea )

Iron deficiency chlorosis is an important abiotic stress affecting groundnut production worldwide in calcareous and alkaline soils with a pH of 7.5–8.5. To identify genomic regions controlling iron deficiency chlorosis resistance in groundnut, the recombinant inbred line population from the cross TAG 24 × ICGV 86031 was evaluated for associated traits like visual chlorosis rating and SPAD chlorophyll meter reading across three crop growth stages for two consecutive years. Thirty-two QTLs were identified for visual chlorosis rating (3.9%–31.8% phenotypic variance explained [PVE]) and SPAD chlorophyll meter reading [3.8%–11% PVE] across three stages over 2 years. This is the first report of identification of QTLs for iron deficiency chlorosis resistance- associated traits in groundnut. Three major QTLs (>10% PVE) were identified at severe stage, while majority of other QTLs were having small effects. Interestingly, two major QTLs for visual chlorosis rating at 60 days (2013) and 90 days (2014) were located at same position on LG AhXIII. The identified QTLs/markers after validation across diverse genetic material could be used in genomics-assisted breeding