Animism in Africa

In our study, we shall endeavor to trace the origin and development of animism as a theory of the origin of religion, view it in action and consider its effect on the lives and souls of the heathen

Magneto-optical trapping of bosonic and fermionic neon isotopes and their mixtures: isotope shift of the ^3P_2 to ^3D_3 transition and hyperfine constants of the ^3D_3 state of Ne-21

We have magneto-optically trapped all three stable neon isotopes, including the rare Ne-21, and all two-isotope combinations. The atoms are prepared in the metastable ^3P_2 state and manipulated via laser interaction on the ^3P_2 to ^3D_3} transition at 640.2nm. These cold (T = 1mK) and environmentally decoupled atom samples present ideal objects for precision measurements and the investigation of interactions between cold and ultracold metastable atoms. In this work, we present accurate measurements of the isotope shift of the ^3P_2 to ^3D_3 transition and the hyperfine interaction constants of the ^3D_3 state of Ne-21. The determined isotope shifts are (1625.9\pm0.15)MHz for Ne-20 to Ne-22, (855.7\pm1.0)MHz for Ne-20 to Ne-21, and (770.3\pm1.0)MHz for Ne-21 to Ne-22. The obtained magnetic dipole and electric quadrupole hyperfine interaction constants are A(^3D_3)= (-142.4\pm0.2)MHz and B(^3D_3)=(-107.7\pm1.1)MHz, respectively. All measurements give a reduction of uncertainty by about one order of magnitude over previous measurements

Oxidative damage to recombinant proteins during production

Thesis (Ph.D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1998.Includes bibliographical references (p. 209-222).Since the introduction of recombinant human insulin nearly two decades ago, recombinant proteins have increasingly been utilized as therapeutic agents. In addition, expression of recombi­nant proteins is now a common tool used in basic research. Recombinant proteins are subject to many subtle modifications that can affect their properties; among these modifications, oxidative damage is one of the most ubiquitous. Oxidative damage, however, is only occasionally consid­ered as a "quality concern" since it rarely detectable using standard biochemical techniques. The production of an oxidatively-sensitive protein, a1-Antitrypsin, was investigated to ascertain the effect of fermentation parameters on the extent of oxidation. Oxidation of either of two methion­ine residues in the active site to methionine sulfoxide was sufficient for inactivation, and 50% of the antitrypsin produced under standard fermentation conditions was oxidized. Oxidative damage was linked to the dissolved oxygen concentration by experimentation and detailed modeling of the evolution and detoxification of reactive oxygen species. Under pseudo steady-state conditions, the fractional oxidation is near zero under anaerobic conditions and increases through the microaero­bic regime. At dissolved oxygen concentrations greater than 10% of air saturation, the fractional oxidation did not vary. Step changes in the dissolved oxygen concentration, designed to emulate possible time variation resulting from poor mixing or changes in gas composition, caused tran­sient increases in the fractional oxidation and enhanced proteolytic degradation. This may impli­cate oxidative stress in scale-up related protein quality and quantity limitations. In addition, oxidative damage to antitrypsin caused a 5-fold increase in the stepwise addition rate for in vitro aggregation, which suggests that oxidative damage will limit shelf stability. In addition, process simulation demonstrated that removal of oxidative variants caused a 100% increase in cost per unit when only 22% of the antitrypsin is oxidized during the fermentation step.by John O. Konz.Ph.D