However, despite 80 years of theoretical attention, near exact calculations for such systems are only available for bound states. On the experimental side, the tests of these calculations are largely based upon level energies or single particle momentum 3 distributions. Very promising and challenging new classes of experiments are those which achieve a complete description of the outcome following the excitation of the ground state to an unbound continuum. The momenta, i.e. the set of vectors, of all the fragments of an atom or molecule break-up can be measured in coincidence with high precision using state-of-the-art imaging and timing techniques [16]. These asymptotic many-particle momentum distributions are determined by the interaction inducing the fragmentation, the bound initial state from which it emerged, and the interactions between the outgoing particles. Thus it is useful to the experimentalist to keep the interaction process as simple as possible and to choose a geometry where final state interactions are negligible or under control. In the present study we used the absorption of a single photon to fragment the deuterium molecule: hν + D 2 → 2 e -+ 2 d + Due to their heavy masses, the initial motion of the nuclei in the continuum can be assumed the same as in the ground state at the instant of the electronic transition (Born Oppenheimer approximation). Once the electrons have left the system, the motion of the nuclei is solely determined by their Coulomb repulsion; they accelerate to a Kinetic Energy Release (KER) which corresponds to the Coulomb potential associated with their initial separation. Quantum mechanically one maps the nuclear vibrational wave-function onto the Coulomb potential to yield a KER spectrum. Inverting this process determines the squared nuclear vibrational wave-function from the measured KER spectrum [17]. Furthermore, by selecting events that occur within a fixed subregion in the KER spectrum, one samples molecules for which the corresponding internuclear distance is defined much more precisely than the full extent of the initial nuclear wave-function. This allows us to show how the electronic continuum momentum distribution depends on the inter-nuclear separation in the molecule and its orientation with respect to the photon polarization. [18,19,20,21]. In brief, inside our momentum spectrometer, a supersonic D 2 -gas jet was crossed with the linear polarized photon beam from the LBNL Advanced Light Source (D 2 provides a higher target density than a comparable H 2 gas jet and data less contaminated by random coincidences from background H 2 O). The electrons and ions created in the intersection of the photons with

A series of platinum(II) boryl complexes of general formula trans-[(Cy(3)P)2Pt(Br)(BX2)], including the rare dibromoboryl species trans-[(Cy(3)P)2Pt(Br)(BBr2)], were synthesized by oxidative addition of the B-Br bond of a number of bromoboranes to [Pt(PCy3)2]. X-ray diffraction studies were performed on several such compounds. Comparison of the Pt--Br bond lengths allowed an empirical assessment of the trans-influence of different boryl ligands. A trans-influence scale was thus deduced and the results were compared with those previously computed for compounds of the type trans-[(Me(3)P)2Pt(Cl)(BX2)].

Although a number of plant natural products are derived from benzoic acid, the biosynthesis of this structurally simple precursor is poorly understood. Hypericum calycinum cell cultures accumulate a benzoic acid-derived xanthone phytoalexin, hyperxanthone E, in response to elicitor treatment. Using a subtracted complementary DNA (cDNA) library and sequence information about conserved coenzyme A (CoA) ligase motifs, a cDNA encoding cinnamate:CoA ligase (CNL) was isolated. This enzyme channels metabolic flux from the general phenylpropanoid pathway into benzenoid metabolism. HcCNL preferred cinnamic acid as a substrate but failed to activate benzoic acid. Enzyme activity was strictly dependent on the presence of Mg2+ and K+ at optimum concentrations of 2.5 and 100 mm, respectively. Coordinated increases in the Phe ammonia-lyase and HcCNL transcript levels preceded the accumulation of hyperxanthone E in cell cultures of H. calycinum after the addition of the elicitor. HcCNL contained a carboxyl-terminal type 1 peroxisomal targeting signal made up by the tripeptide Ser-Arg-Leu, which directed an amino-terminal reporter fusion to the peroxisomes. Masking the targeting signal by carboxyl-terminal reporter fusion led to cytoplasmic localization. A phylogenetic tree consisted of two evolutionarily distinct clusters. One cluster was formed by CoA ligases related to benzenoid metabolism, including HcCNL. The other cluster comprised 4-coumarate:CoA ligases from spermatophytes, ferns, and mosses, indicating divergence of the two clades prior to the divergence of the higher plant lineages.

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We report the first kinematically complete study of the four-body fragmentation of the D2 molecule following absorption of a single photon. For equal energy sharing of the two electrons and a photon energy of 75.5 eV, we observed the relaxation of one of the selection rules valid for He photo-double-ionization and a strong dependence of the electron angular distribution on the orientation of the molecular axis. This effect is reproduced by a model in which a pair of photoionization amplitudes is introduced for the light polarization parallel and perpendicular to the molecular axis.

We propose a dynamic general equilibrium model that yields testable implications about the …scal policy run by governments of di¤erent political color. Successive gen-

Abstract:In plants, prenylation of metabolites is widely distributed to generate compounds with efficient defense potential and distinct pharmacological activities profitable to human health. Prenylated compounds are formed by members of the prenyltransferase (PT) superfamily, which catalyze the addition of prenyl moieties to a variety of acceptor molecules. Cell cultures of Hypericum calycinum respond to elicitor treatment with the accumulation of the prenylated xanthone hyperxanthone E. A cDNA encoding a membrane-bound PT (HcPT) was isolated from a subtracted cDNA library and transcript preparations of H. calycinum. An increase in the HcPT transcript level preceded hyperxanthone E accumulation in cell cultures of H. calycinum treated with elicitor. The HcPT cDNA was functionally characterized by expression in baculovirus-infected insect cells. The recombinant enzyme catalyzed biosynthesis of 1,3,6,7-tetrahydroxy-8-prenylxanthone through regiospecific C-8 prenylation of OPEN ACCESSMolecules 2015, 20 15617 1,3,6,7-tetrahydroxyxanthone, indicating its involvement in hyperxanthone E formation. The enzymatic product shared significant structural features with the previously reported cholinesterase inhibitor γ-mangostin. Thus, our findings may offer a chance for semisynthesis of new active agents to be involved in the treatment of Alzheimer's disease.

In this paper, we construct and estimate a uni…ed model combining three of the main sources of cross-country income disparities: di¤erences in factor endowments, barriers to technology adoption and the inappropriateness of frontier technologies to local conditions. The key components of our framework are di¤erent types of workers (skilled and unskilled labor), distortions to capital accumulation, directed technical change, costly adoption and spillovers from the world technology frontier. Despite its parsimonious parametrization, our empirical model provides a good …t of GDP data for up to 90 countries in 1970 and 2000. We use the model to assess the relative importance of alternative factors a¤ecting the world income distribution and to perform counterfactual experiments. Our results suggests that removing barriers to technology adoption would increase output of the average OECD economy relative to the US frontier from 68.3% to 92.5%. The average non-OECD country would instead increase from 17.4% to 53.8%. Slashing barriers would also lead to higher skill premia in all countries. We also study how globalization can shape income disparities. In the absence of global IPR protection, we …nd that trade in goods ampli…es income disparities, induces skill-biased technology adoption and increases skill premia in the majority of countries. These results are reverted if trade liberalization is coupled with international protection of IPR.JEL Classi…cation: F43, O11, O31, O33, O38, O41, O43, O47.