We numerically propose a way to perform quantum computations by combining an ensemble of molecular states and weak laser pulses. A logical input state is expressed as a superposition state (a wave packet) of molecular states, which is initially prepared by a designed femtosecond laser pulse. The free propagation of the wave packet for a specified time interval leads to the specified change in the relative phases among the molecular basis states, which corresponds to a computational result. The computational results are retrieved by means of quantum interferometry. Numerical tests are implemented in the vibrational states of the B state of I2 employing controlled-NOT gate, and 2 and 3 qubits Fourier transforms. All the steps involved in the computational scheme, i.e., the initial preparation, gate operation, and detection steps, are achieved with extremely high precision.
Genes involved in the phospholipid synthesis of Saccharomyces cerevisiae, such as PEM1, PEM2, PSS, and INO1, are coordinately repressed by myo-inositol and choline. In order to investigate this regulation, we transformed wild-type yeast with a PEM1 promoter-lacZ fusion and isolated two mutants, named ric1 and ric2 (regulation by myo-inositol and choline), exhibiting decreased PEM1 expression. The lowered PEM1 expression in the mutants was monitored in colonies in terms of their failure fully to develop blue color on 5-bromo-4-chloro-3- indolyl-β-galactopyranoside-containing agar. ric1 mutant was auxo trophic for myo-inositol, indicating that INO1 expression was also affected, whereas ric2 mutant required myo-inositol only in the presence of choline. The RICI gene was isolated by complementation of the Ino- phenotype of ric1 mutant and its identity was confirmed by genetic cross between the original rid mutant and a gene disruptant. The RIC1 gene was sequenced and found to be identical with the previously identified gene, SNF2/SWI2/ GAM1/ TYE3, which is known to encode a general transcription factor required for the expression of various genes including INO1. Analysis using various lacZ fusion constructs containing promoters for genes in phospholipid synthesis revealed that the expression of myo-inositol-choline-regulated genes, PEM1, PEM2, PSS, CM, and INO1, was markedly decreased in the snf2/ swi2/gaml / tye3/ ric1 background, but the expression of a con stitutive gene, PIS, was not. We conclude that SNF2/SWI2/GAM1/TYE3/RIC1 is a positive regulatory gene required for the expression of not only INO1 gene, but also of myo-inositol-choline-regulated genes in general.
Angular distributions of multiplet-specific N 1s photoelectrons from the fixed-in-space NO molecules have been measured for the first time. The dynamics of the σ* shape resonance appearing in the channel leading to the 3Π and 1Π ionic states has been made clear from the analyses of the angular distributions. Multiplet-specific multichannel calculations have reproduced the observed angular distributions fairly well.
Abstract Previous studies in our laboratory led to the elucidation of the covalent structure of a tetraacyldisaccharide 1,4'-bisphosphate precursor of lipid A (designated lipid IVA), that accumulates at 42 degrees C in temperature-sensitive mutants defective in 3-deoxy-D-manno-octulosonic acid (KDO) biosynthesis (Raetz, C. R. H., Purcell, S., Meyer, M. V., Qureshi, N., and Takayama, K. (1985) J. Biol. Chem. 260, 16080-16088). Using [4'-32P]lipid IVA as the probe, we now demonstrate the existence of cytoplasmic KDO-transferases in Escherichia coli capable of attaching 2 KDO residues, derived from CMP-KDO, to lipid IVA. A partial purification has been developed to obtain a cytoplasmic subfraction that adds these 2 KDO residues with a 90% yield. The product is shown to have the stoichiometry of (KDO)2-IVA by fast atom bombardment mass spectrometry and NMR spectroscopy. The partially purified enzyme can utilize alternative lipid-disaccharide cosubstrates bearing five or six fatty acyl chains, but it has an absolute requirement for a monophosphate residue at position 4' of the lipid acceptor. When reincubated with a crude cytoplasmic fraction, a nucleoside triphosphate and Mg2+, (KDO)2-IVA is rapidly metabolized to more polar substances, the identity of which is unknown. The KDO-transferase(s) described in the present study should be very useful for the semisynthetic preparation of complex lipopolysaccharide substructures and analogs.
The absolute values of the cross section for formation of a $2p$ atom pair in the photoexcitation of ${\mathrm{H}}_{2}$ and ${\mathrm{D}}_{2}$ are measured against the incident photon energy in the range of doubly excited states by means of the coincidence detection of two Lyman-$\ensuremath{\alpha}$ photons. The cross-section curves are explained only by the contribution of the doubly excited ${Q}_{2}\phantom{\rule{0.16em}{0ex}}^{1}\mathrm{\ensuremath{\Pi}}_{u}(1)$ state. The isotope effect on the oscillator strengths of $2p+2p$ pair formation for ${\mathrm{H}}_{2}$ and ${\mathrm{D}}_{2}$ from the ${Q}_{2}\phantom{\rule{0.16em}{0ex}}^{1}\mathrm{\ensuremath{\Pi}}_{u}(1)$ state is almost the same as that on the oscillator strengths of $2s+2p$ pair formation from the ${Q}_{2}\phantom{\rule{0.16em}{0ex}}^{1}\mathrm{\ensuremath{\Pi}}_{u}(1)$ state obtained by our group [T. Odagiri et al., Phys. Rev. A 84, 053401 (2011)]. This channel independence indicates that both isotope effects are dominated by the early dynamics of the ${Q}_{2}\phantom{\rule{0.16em}{0ex}}^{1}\mathrm{\ensuremath{\Pi}}_{u}(1)$ state, before reaching the branching point into $2p+2p$ pair formation and $2s+2p$ pair formation.
Synopsis Dipole oscillator strengths for the formation of excited hydrogen atom from C 2 H 2 were measured to investigate formation and decay of molecular superexcited states. It seems that non-adiabatic transition plays an important role in the formations of the hot hydrogen atom.
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