The decays of the high angular momentum, high spin 4F0 states of the electron configuration 3s3p3d in aluminium-like ions (with three electrons outside a closed shell) have been identified in delayed spectra of foil excited Ti, Fe and Ni ion beams. The line identifications were aided by HXR, MCHF, and MCDF calculations and are corroborated by lifetime measurements which demonstrate the differential longevity of the fine structure levels. A search for the related case of ls2p3d4Fo level decays in Li-like ions of Si, P and S failed.
Two parameters of the unresponsiveness to lipopolysaccharides from Escherichia coli (LPS) displayed by C3H/HeJ mice, namely endotoxemia and the intraperitoneal extravascular leukocyte responses to small doses of LPS, have been studied by Sultzer and found to be under polygenic control (1, 2) . Recently, however, Watson and Riblet (3) presented evidence interpreted as indicating that a single gene was responsible for influencing both mitogenic (polyclonal) and immunogenic (specific) responses to LPS, by analysing crosses between LPS low-responder mice and high-responder strains. Since the B-cell unresponsiveness of C3H/HeJ mice has been shown to depend upon a pure defect in the subpopulation of B cells which interacts with and responds to LPS in the conventional strains,' the finding of Watson and Riblet is of great importance . Thus, it seems possible that the defective gene in C3H/HeJ mice would code for the B-cell surface structure involved in cell triggering, both in polyclonal (4) and in specific (3, 5, 6) antibody responses. According to our current view in B-cell activation, such "mitogen receptor" is the only structure on the B-cell surface which is competent to deliver activating signals to the resting cell (7). If this were the case, C3H/HeJ mice would be of great importance for elucidating the molecular mechanisms governing the generation and delivery of triggering signals. We report in this paper evidence on the inheritance of the genetical defect displayed by C3H/HeJ mice with regard to the direct B-cell responses to LPS as evidenced by polyclonal and specific responses as well .
Materials and MethodsC3H/HeJ (H-2') mice were obtained from Jackson Laboratories, Bar Harbor, Maine, and bred in our colony for the last 3 yr. Other mice obtained from that source were also directly used in some experiments . The high-responder strains used in these experiments were C3H/Tif (H-2'°) obtained from Bomholtgaard, Rye, Denmark, and B10.5M (H-2°) from our own colony .LPS from Escherichia coli 055:135 obtained by phenol-water extraction (8) was used throughout these experiments . The hapten (4-hydroxy-3,5-dinitrophenyl)acetyl (NNP) was conjugated to LPS as previously described (9) and the biological characterization of the conjugate used in the present
The lifetimes of the resonance levels in the Al-like ions Ti X, Fe XIV and Ni XVI have been obtained from beam-foil measurements using a variety of analytical techniques. The spectral analysis and identification of cascade transitions necessary for application of the ANDC procedure have been aided by recent observations of laser-produced plasmas. The lifetime values obtained from ANDC analyses for the 3 s 3 p2 doublet levels agree well with predictions based on semi-empirical Hartree-Fock calculations. However, the ANDC results for the 3 s 2 3 d levels fall between the values obtained using multi-exponential curve-fitting and from the calculations.
Following an earlier observation in F VI we identified the line pair Is2s2p2 5p-Is2s2p3d 5p o , 5D o for the elements N, 0, Mg, and tentatively for Al and Si in beam-foil spectra. Assignment was established by comparison with Multi-Configuration Dirac-Fock calculations along the isoelectronic sequence. Using this method we also identified some quartet lines of lithiumlike ions with Z > 10.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.