Precise numerical results for limit cycles in the quantum three-body problem

The study of the three-body problem with short-range attractive two-body forces has a rich history going back to the 1930s. Recent applications of effective field theory methods to atomic and nuclear physics have produced a much improved understanding of this problem, and we elucidate some of the issues using renormalization group ideas applied to precise nonperturbative calculations. These calculations provide 11-12 digits of precision for the binding energies in the infinite cutoff limit. The method starts with this limit as an approximation to an effective theory and allows cutoff dependence to be systematically computed as an expansion in powers of inverse cutoffs and logarithms of the cutoff. Renormalization of three-body bound states requires a short range three-body interaction, with a coupling that is governed by a precisely mapped limit cycle of the renormalization group. Additional three-body irrelevant interactions must be determined to control subleading dependence on the cutoff and this control is essential for an effective field theory since the continuum limit is not likely to match physical systems (e.g., few-nucleon bound and scattering states at low energy). Leading order calculations precise to 11-12 digits allow clear identification of subleading corrections, but these corrections have not been computed.     

Tilivalline,a new pyrrolo[2, 1-c][1,4] benzodiazepine metabolite from klebsiella

From Klebsiella pneumoniae (+)(11S, 11aS) - 1,2,3,10,11,11a - hexahydro - 9 - hydroxy - 11 - (3′ - indolyl) - 5H - pyrrolo[2,1-c][1,4]benzodiazepin - 5 - one (1) has been isolated for which the name tilivalline is suggested. Structure elucidation and synthesis are reported.     

MODE OF COACTION OF PHYTOCHROME AND BLUE LIGHT PHOTORECEPTOR IN CONTROL OF HYPOCOTYL ELONGATION

Abstract The rate of hypocotyl longitudinal growth in seedlings of Sesamum indicum L. is strongly inhibited by continuous blue light (cBL)† and slightly by continuous far-red light while continuous red light (cRL) or red light pulses are hardly effective from 60 h after sowing onwards. Between 36 and 60 h after sowing the growth rate responds to red light pulses the effect of which is fully reversible by long wavelength far-red light. When seedlings are kept in cBL for 3 days and then treated with red light hypocotyl growth rate responds strongly. However, RL effectiveness decreases with time after transfer from BL to RL. BL → darkness transfer experiments with different levels of P_fr established at the beginning of darkness show that after a BL pretreatment phytochrome (P_fr) alone is capable of fully controlling growth rate. When white light (WL) is given no BL effect is detectable in weak WL. Only high light fluxes maintain a typical BL growth rate. At medium WL fluxes elongation rate returns gradually to the dark rate. The simplest explanation of the data is that light absorbed by a separate BL photoreceptor is necessary to maintain responsivity to P_fr. With increasing age of the seedlings the requirement for BL increases strongly. On the other hand, brief light pulses—given to demonstrate photoreversibility of phytochrome—remain equally effective provided that responsivity to P_fr exists.     

EFFECT OF BLUE/UV LIGHT ON ANTHOCYANIN SYNTHESIS IN TOMATO SEEDLINGS IN THE ABSENCE OF BULK CAROTENOIDS

Abstract Anthocyanin synthesis in the hypocotyl of tomato ( Lycopersicon esculentum ) seedlings responds strongly and specifically to blue/UV light while the response to red and far-red light, operating through phytochrome, is weak. The herbicide Norflurazon (SAN 9789) was used to inhibit synthesis of colored carotenoids almost completely without affecting growth and development measurably. Even though carotenoid content was reduced to less than 2% of normal and the fluence rate response function for blue and UV light was linear within the experimental range, Norflurazon treatment did not reduce seedling sensitivity toward blue/UV light. It was concluded that at least'bulk'carotenoids are not the photoreceptor chromophore of the blue/UV photoreceptor pigment.     

STIMULATION OF THE SHIBATA SHIFT BY PHOTOCHROME IN THE COTYLEDONS OF THE MUSTARD SEEDLING SINAPIS ALBA L.

Abstract— In the cotyledons of the mustard seedling Sinapis alba L. the duration of the Shibata shift can be greatly shortened by a pretreatment with light pulses prior to the protochlorophyllide– chloro-phyllide a photoconversion. It was shown that the light pulses act through photochrome (P _fr ). Since reversibility of a red light pulse induction by a far-red light pulse is rapidly lost (within 2 min) it is concluded that at least the initial action of P_fr occurs rapidly in this response. On the other hand, the effect of a red light pulse on the rate of protochlorophyll regeneration in the mustard seedling cotyledons is fully reversible by a far-red light pulse for more than 5 min. It is concluded that control of protochlorophyll regeneration and control of the Shibata shift by phytochrome cannot be consequences of the same initial action of P_fr Apparently P_fr controls both phenomena independently.     

Gradient formation of anthocyanin in seedlings of Fagopyrum and Sinapis unilaterally exposed to red and far-red light

Abstract— Anthocyanin synthesis was measured in hypocotyl halves excised from Fagopyrum and Sinapis seedlings irradiated unilaterally or equilaterally with red or far-red light. Although no phototropic curvatures are produced by red or far-red exposure, a significant gradient in anthocyanin formation was observed for Fagopyrum seedlings and the trend for gradient formation is present in Sinapis seedlings. The gradient production in Fagopyrurn is correlated with this tissue's greater optical density. Since the intensities used do not inhibit elongation completely (through the phytochrome system) and an intensity gradient is present in the tissue (as evidenced by anthocyanin formation) it is concluded that (a) a steeper light gradient is required to induce phototropic curvatures or (b) a diffusible material affecting elongation growth prevents any differential from being established across the tissue.     

Angular dependence of the polarization of the recoil proton from the reaction γp→π0p in the region of the third resonance

The polarization of the recoil proton from the reactionp ⁰ p has been measured for photon energies between 900–1,350 MeV and pion c.m. angles between 70° and 150°. There are significant deviations from recent analysis.     

Identification of active sites in gold-catalyzed hydrogenation of acrolein

The active sites of supported gold catalysts, favoring the adsorption of C=O groups of acrolein and subsequent reaction to allyl alcohol, have been identified as edges of gold nanoparticles. After our recent finding that this reaction preferentially occurs on single crystalline particles rather than multiply twinned ones, this paper reports on a new approach to distinguish different features of the gold particle morphology. Elucidation of the active site issue cannot be simply done by varying the size of gold particles, since the effects of faceting and multiply twinned particles may interfere. Therefore, modification of the gold particle surface by indium has been used to vary the active site characteristics of a suitable catalyst, and a selective decoration of gold particle faces has been observed, leaving edges free. This is in contradiction to theoretical predictions, suggesting a preferred occupation of the low-coordinated edges of the gold particles. On the bimetallic catalyst, the desired allyl alcohol is the main product (selectivity 63%; temperature 593 K, total pressure p(total) = 2 MPa). From the experimentally proven correlation between surface structure and catalytic behavior, the edges of single crystalline gold particles have been identified as active sites for the preferred C=O hydrogenation.     

Synthesis and characterization of a new benzofulvene polymer showing a thermoreversible polymerization behavior

A new polymer based on a functionalized benzofulvene moiety has been synthesized by spontaneous polymerization of the monomer in the solid state. This polymer shows a very high molar mass, high solubility in the most common organic solvents, and thermoreversible polymerization properties. An interesting application in synthesis is reported.     

Asymmetric synthesis of α-hydroxy-esters via ester enolates

3-Phenylpropionates of chiral alcohols derived from (+)-camphor are oxidized by Mo0₅· Py·HMPT (MoOPH) with high diastereoselectivity.