We review the classical observational results for isotopic abundance variations for several elements in CP stars. We concentrate on the " newest " anomaly, in calcium. The cosmically very rare isotope, 48 Ca can rival and even dominate the more common, alpha nuclide, 40 Ca. Relevant examples are found in the hot, non-magnetic HgMn stars, and the field horizontal-branch star, Feige 86. The calci...

The mechanism of L-ribulose 5-phosphate 4-epimerase of Aerobacfer aerogenes has been investigated by determining the kinetic isotope effect (KT/KH) for the epimerization of D-[4-T]xylulose 5-phosphate in the presence of D-[l-14C]xylulose 5-phosphate. The ratio of T:14C was determined for the isolated L-ribulose derived from aliquots of an epimerization reaction mixture during its progress towar...

A 5,5-d2 -luciferin was prepared to measure isotope effects on reactions of two intermediates in firefly bioluminescence: emission by oxyluciferin and elimination of a putative luciferyl adenylate hydroperoxide to dehydroluciferin. A negligible isotope effect on bioluminescence provides further support for the belief that the emitting species is the keto-phenolate of oxyluciferin and rules out ...

The primary, alpha-secondary, beta-secondary, and beta'-secondary deuterium and primary 18O kinetic isotope effects on V/K for the dehydration of [(3S)-3-hydroxybutyryl]pantetheine by bovine liver crotonase (enoyl-CoA hydratase, EC 4.2.1.17) have been determined by the equilibrium perturbation method. The primary deuterium and 18O kinetic isotope effects are 1.61 and 1.051, respectively. The se...

We measure the hyperfine splitting of the 9S_{1/2} level of 210Fr, and find a magnetic dipole hyperfine constant A=622.25(36) MHz. The theoretical value, obtained using the relativistic all-order method from the electronic wave function at the nucleus, allows us to extract a nuclear magnetic moment of 4.38(5)micro_{N} for this isotope, which represents a factor of 2 improvement in precision ove...

During the Miocene prominent oxygen isotope events (Mi-events) reflect major changes in glaciation, while carbonate isotope maxima (CM-events) reflect changes in organic carbon burial, particularly during the Monterey carbon isotope excursion. However, despite their importance to the global climate history they have never been recorded in shallow marine carbonate successions. The Decontra secti...

The excitation functions of the key reactions of stellar nucleosynthesis, 12C(α, γ)16O and 22Ne(α, n)25Mg, have been determined with an experimental sensitivity of 10−11 barn. For 12C(α, γ)16O the SE1and SE2-factors deduced from the γ angular distributions have been extrapolated into the range of helium burning temperatures applying the R-matrix method, which yielded S300 E1 = (76± 20) keVb and...