Experimental Studies of the NaCs 53Π0 and a3Σ+ States

We report high resolution measurements of 372 NaCs 53Π0(v, J) ro-vibrational level energies in the range 0 ≤ v ≤ 22. The data have been used to construct NaCs 53Π0 potential energy curves using the Rydberg–Klein-Rees and inverted perturbation approximation methods. Bound-free 53Π0(v, J) → 1(a)3Σ+ emission has also been measured, and is used to determine the repulsive wall of the 1(a)3Σ+ state and the 53Π0 → 1(a)3Σ+ relative transition dipole moment function. Hyperfine structure in the 53Π0 state has not been observed in this experiment. This null result is explained using a simple vector coupling model

Production of J/ψJ/\psi-pairs at HERA-N⃗\vec{{\rm N}}

The production of $J/\psi$-pairs as a possible measure of the polarized gluon distribution $\Delta G(x)$ is studied for proton--nucleon collisions at \sqrt{s} =40\;\mbox{GeV}^2 (HERA-$\vec{{\rm N}}$). Possibilities of reconstructing the helicity state of at least one of the $J/\psi$'s are critically reviewed. The observation of production asymmetries in the single polarized mode of HERA-$\vec{{\rm N}}$ is found to be not feasible.Comment: 8 pages, LATeX, 3 figures availabe as .uu-fil

Collisional Transfer of Population and Orientation in NaK

We report current work to study transfer of population and orientation in collisions of NaK molecules with argon and potassium atoms using polarization labeling (PL) and laser- induced fluorescence (LIF) spectroscopy. In the PL experiment, a circularly polarized pump laser excites a specific NaK A1Σ +(v 0=16, J 0 ) ← X1Σ +(v 00=0, J 0 ± 1) transition, creating an orientation (non-uniform MJ0 level distribution) in both levels. The linearly polarized probe laser is scanned over various 31Π(v, J 0±1) ← A1Σ +(v 0=16, J 0 ) transitions. The probe laser passes through a crossed linear polarizer before detection, and signal is recorded if the probe laser polarization has been modified by the vapor (which occurs when it comes into resonance with an oriented level). Using both spectroscopic methods, analysis of weak collisional satellite lines adjacent to these directly populated lines, as a function of argon buffer gas pressure and cell temperature, allows us to discern separately the effects collisions with argon atoms and potassium atoms have on the population and orientation of the molecule. In addition, code has been written which provides a theoretical analysis of the process, through a solution of the density matrix equations of motion for the system

Bone Marrow Colony-Formation In Vitro After Infection of Genetically Defined Inbred Mice with Candida Albicans

The effect of C. albicans infection on the production of haematopoietic precursor cells in the bone marrow of CBA/CaH and BALB/c mice was evaluated by assay of colony formation in vitro. In immunocompetent mice, neither systemic nor oral infection induced significant alterations in colony formation by bone marrow from the two mouse strains, and Candida infection did not alter the proportion of morphological cell types in the colonies. However, the number of neutrophil-like was relatively greater in colonies derived from acutely infected CBA/CaH nude mice than in those from BALB/c nude mice, whereas small mononuclear cells were present in higher proportions in the latter strain. In both strains of nude mice, there was an increase in colony formation at 6 days after oral infection, but at 8 weeks, when the infection had become chronic, the production of bone marrow cells by CBA/CaH nude mice was significantly less than that by BALB/c nude mice. Reconstitution of nude mice with syngeneic lymphocytes enhanced the production of bone marrow precursor cells by BALB/c, but not by CBA/CaH mice, suggesting that T cells can enhance host resistance by promoting the colony-forming response of the bone marrow in BALB/c mice that are genetically resistant to tissue damage, but not in CBA/CaH that are prone to severe lesions. Finally, culture with Candida antigen in vitro decreased the number of colony-forming cells in cultures from CBA/CaH, but not from BALB/c mice

Polarization Spectroscopy and Collisions in NaK

We report current work to study transfer of population and orientation in collisions of NaK molecules with argon and potassium atoms using polarization labeling (PL) and laser-induced fluorescence (LIF) spectroscopy. In the PL experiment, a circularly polarized pump laser excites a specific NaK A1Σ +(v=16, J) ← X1Σ +(v=0, J ± 1) transition, creating an orientation (non-uniform MJ level distribution) in both levels. The linear polarized probe laser is scanned over various 3 1Π(v=8, J 0 ± 1) ← A1Σ +(v=16, J 0 ) transitions. The probe laser passes through a crossed linear polarizer before detection, and signal is recorded if the probe laser polarization has been modified by the vapor (which occurs when it comes into resonance with an oriented level). In addition to strong direct transitions (J 0 = J), we also observe weak collisional satellite lines (J 0 = J ±n with n = 1, 2, 3, ...) indicating that orientation is transferred to adjacent rotational levels during a collision. An LIF experiment (with linear polarized pump and probe beams) gives information on the collisional transfer of population. From these data, cross sections for both processes can be determined. We experimentally distinguish collisions of NaK with argon atoms from collisions with alkali atoms

Results on the nucleon spin structure

SMC performed an investigation of the spin structure of the nucleon by measuring deep inelastic scattering of polarised muons off polarised protons and deuterons. A summary of the results for spin structure functions and sum rules is given.Comment: 8 pages, LaTeX, Talk given at the Workshop on "Symmetry and Spin - PRAHA98", Prag, September 1998. Proceedings to be published by Czech. Journ. Phy

Isolates of Candida albicans that differ in virulence for mice elicit strain-specific antibody-mediated protective responses

Three distinct isolates of Candida albicans were used to establish systemic and oral infections in inbred mice that are genetically resistant or susceptible to tissue damage. Patterns of infection differed significantly between both yeasts and mouse strains. Systemic infection conferred significant protection against re-challenge with the homologous, but not the heterologous yeast; however, the protective effect was more evident in the tissue-susceptible CBA/CaH mice than in the resistant BALB/c strain. In contrast, oral infection induced protection against both homologous and heterologous oral challenge, although this was significant only in the CBA/CaH mice. CBA/CaH mice produced antibodies of both IgG1 and IgG2a subclasses, whereas BALB/c mice produced predominantly IgG1. Western blotting demonstrated considerable differences between epitopes recognised by serum antibodies from mice of both strains after immunisation with each of the three yeasts. Thus, different strains of yeast show considerable specificity in antibody responses elicited by either systemic or oral infection. (c) 2005 Elsevier SAS. All rights reserved

IL-12 and Related Cytokines: Function and Regulatory Implications in Candida albicans Infection

IL-12 is a cytokine with links to both innate and adaptive immunity systems. In mice, its deletion leads to acute susceptibility to oral infection with the yeast Candida albicans, whereas such mice are resistant to systemic disease. However, it is an essential component of the adaptive response that leads to the generation of Th1-type cytokine responses and protection against disseminated disease. This paper presents an overview of the role of IL-12 in models of systemic and mucosal infection and the possible relationships between them

Systems of Accumulation and the Evolving MEC

The limitations of the Developmental State Paradigm were discussed in the introductory chapter to this volume. This chapter offers an alternative approach to the DSP through use of the notion of systems of (capital) accumulation and its specific application to South Africa’s evolving political economy, which we characterise as the ‘Minerals-Energy Complex’ (MEC) following Fine and Rustomjee (1996)