CP Violation and the Width Z→bbˉZ\rightarrow b\bar{b}

We discuss the effect of CP-violating $Zb\bar{b}$, $Zb\bar{b}G$ and $Zb\bar{b}\gamma$ couplings on the width $\Gamma(Z\rightarrow b\bar bX)$. The presence of such couplings leads in a natural way to an increase of this width relative to the prediction of the standard model. Various strategies of a direct search for such CP-violating couplings by using CP-odd observables are outlined. The number of $Z$ bosons required to obtain significant information on the couplings in this way is well within the reach of present LEP experiments.Comment: 18 pages, LaTeX, no figure

Bioassay-guided isolation and identification of antimicrobial compounds from thyme essential oil by means of overpressured layer chromatography, bioautography and GC-MS

A simple method is described for efficient isolation of compounds having an antibacterial effect. Two thyme (Thymus vulgaris) essential oils, obtained from the market, were chosen as prospective materials likely to feature several bioactive components when examined by thin layer chromatography coupled with direct bioautography as a screening method. The newly developed infusion overpressured layer chromatographic separation method coupled with direct bioautography assured that only the active components were isolated by means of overrun overpressured layer chromatography with online detection and fractionation. Each of the 5 collected fractions represented one of the five antimicrobial essential oil components designated at the screening. The purity and the activity of the fractions were confirmed with chromatography coupled various detection methods (UV, vanillin-sulphuric acid reagent, direct bioautography). The antibacterial components were identified with GC-MS as thymol, carvacrol, linalool, diethylphthalate, and alpha-terpineol. The oil component diethyl-phthalate is an artificial compound, used as plasticizer or detergent bases in the industry. Our results support that exploiting its flexibility and the possible hyphenations, overpressured layer chromatography is especially attractive for isolation of antimicrobial components from various matrixes

Soft Photons in Hadron-Hadron Collisions: Synchrotron Radiation from the QCD Vacuum?

We discuss the production of soft photons in high energy hadron-hadron collisions. We present a model where quarks and antiquarks in the hadrons emit ``synchrotron light'' when being deflected by the chromomagnetic fields of the QCD vacuum, which we assume to have a nonperturbative structure. This gives a source of prompt soft photons with frequencies $\omega <= 300 MeV$ in the c.m. system of the collision in addition to hadronic bremsstrahlung. In comparing the frequency spectrum and rate of ``synchrotron'' photons to experimental results we find some supporting evidence for their existence. We make an exclusive--inclusive connection argument to deduce from the ``synchrotron'' effect a behaviour of the neutron electric formfactor $G_E^n(Q^2)$ proportional to $(Q^2)^{1/6}$ for $Q^2 < 20 fm^{-2}$. We find this to be consistent with available data. In our view, soft photon production in high energy hadron-hadron and lepton-hadron collisions as well as the behaviour of electromagnetic hadron formfactors for low $Q^2$ are thus sensitive probes of the nonperturbative structure of the QCD vacuum.Comment: Heidelberg preprint HD-THEP-94-36, 31 pages, LaTeX + ZJCITE.sty (included), 12 figures appended as uuencoded compressed ps-fil

Detection of antibacterial activity of essential oil components by TLC-bioautography using luminescent bacteria

The aim of the present study was the chemical characterization of some medically relevant essential oils (tea tree, clove, cinnamon bark, thyme and eucalyptus) and the investigation of antibacterial effect of the components of these oils by use of a direct bioautographic method. Thin layer chromatography (TLC) was combined with biological detection in this process. The chemical composition of the oils was determined by gas chromatography (GC) and gas chromatography-mass spectrometry (GC-MS). Eucalyptol (84.2%) was the main component of the essential oil of eucalyptus, eugenol (83.7%) of clove oil, and trans-cinnamic aldehyde (73.2%), thymol (49.9%) and terpinen-4-ol (45.8%) of cinnamon bark, thyme and tea tree oils, respectively. Antibacterial activity of the separated components of these oils, as well as their pure main components (eucalyptol, eugenol, trans-cinnamic aldehyde and thymol) was observed against the Gram-negative luminescence tagged plant pathogenic bacterium Pseudomonas syringae pv. maculicola (Psmlux) and the Gram-negative, naturally luminescent marine bacterium Vibrio fischeri. On the whole, the antibacterial activity of the essential oils could be related to their main components, but the minor constituents may be involved in this process. Trans-cinnamic aldehyde and eugenol were the most active compounds in TLC-bioautography. The sensitivity of TLC-bioautographic method can be improved with using luminescent test bacteria. This method is more cost-effective and provides more reliable results in comparison with conventional microbiological methods, e.g. disc-diffusion technique

Evaluation of Hungarian Wines for Resveratrol by Overpressured Layer Chromatography

A method, including solid phase extraction sample preparation, overpressured layer chromatographic separation and subsequent densitometric evaluation, was developed for measurement of total resveratrol (cis- and trans-isomers) content of wine. The amount of resveratrol was determined in wine samples from different winemaking regions of Hungary. The total resveratrol was high in Hungarian red wines (3.6–11 mg/L), and much lower in white ones (0.04–1.5 mg/L)

Palaeoproterozoic magnesite: lithological and isotopic evidence for playa/sabkha environments

Magnesite forms a series of 1- to 15-m-thick beds within the approximate to2.0 Ga (Palaeoproterozoic) Tulomozerskaya Formation, NW Fennoscandian Shield, Russia. Drillcore material together with natural exposures reveal that the 680-m-thick formation is composed of a stromatolite-dolomite-'red bed' sequence formed in a complex combination of shallow-marine and non-marine, evaporitic environments. Dolomite-collapse breccia, stromatolitic and micritic dolostones and sparry allochemical dolostones are the principal rocks hosting the magnesite beds. All dolomite lithologies are marked by delta C-13 values from +7.1 parts per thousand to +11.6 parts per thousand (V-PDB) and delta O-18 ranging from 17.4 parts per thousand to 26.3 parts per thousand (V-SMOW). Magnesite occurs in different forms: finely laminated micritic; stromatolitic magnesite; and structureless micritic, crystalline and coarsely crystalline magnesite. All varieties exhibit anomalously high delta C-13 values ranging from +9.0 parts per thousand to +11.6 parts per thousand and delta O-18 values of 20.0-25.7 parts per thousand. Laminated and structureless micritic magnesite forms as a secondary phase replacing dolomite during early diagenesis, and replaced dolomite before the major phase of burial. Crystalline and coarsely crystalline magnesite replacing micritic magnesite formed late in the diagenetic/metamorphic history. Magnesite apparently precipitated from sea water-derived brine, diluted by meteoric fluids. Magnesitization was accomplished under evaporitic conditions (sabkha to playa lake environment) proposed to be similar to the Coorong or Lake Walyungup coastal playa magnesite. Magnesite and host dolostones formed in evaporative and partly restricted environments; consequently, extremely high delta C-13 values reflect a combined contribution from both global and local carbon reservoirs. A C- 13-rich global carbon reservoir (delta C-13 at around +5 parts per thousand) is related to the perturbation of the carbon cycle at 2.0 Ga, whereas the local enhancement in C-13 (up to +12 parts per thousand) is associated with evaporative and restricted environments with high bioproductivity

Application of direct bioautography and SPME-GC-MS for the study of antibacterial chamomile ingredients

The isolation and characterization of antibacterial chamomile components were performed by the use of direct bioautography and solid phase microextraction (SPME)-GC-MS. Four ingredients, active against Vibrio fischeri, were identified as the polyacetylene geometric isomers cis- and trans-spiroethers, the coumarin related herniarin, and the sesquiterpene alcohol (-)-alpha-bisabolol

Soft Color Interactions and Diffractive Hard Scattering at the Fermilab Tevatron

An improved understanding of nonperturbative QCD can be obtained by the recently developed soft color interaction models. Their essence is the variation of color string-field topologies, giving a unified description of final states in high energy interactions, e.g., diffractive and nondiffractive events in ep and ppbar. Here we present a detailed study of such models (the soft color interaction model and the generalized area law model) applied to ppbar, considering also the general problem of the underlying event including beam particle remnants. With models tuned to HERA ep data, we find a good description also of Tevatron data on production of W, beauty and jets in diffractive events defined either by leading antiprotons or by one or two rapidity gaps in the forward or backward regions. We also give predictions for diffractive J/psi production where the soft exchange mechanism produces both a gap and a color singlet ccbar state in the same event. This soft color interaction approach is also compared with Pomeron-based models for diffraction, and some possibilities to experimentally discriminate between these different approaches are discussed.Comment: 35 pages, 15 figures, uses REVTeX. Minor changes, version to appear in Phys. Rev.

Evidence for an Excess of Soft Photons in Hadronic Decays of Z^0

Soft photons inside hadronic jets converted in front of the DELPHI main tracker (TPC) in events of qqbar disintegrations of the Z^0 were studied in the kinematic range 0.2 < E_gamma < 1 GeV and transverse momentum with respect to the closest jet direction p_T < 80 MeV/c. A clear excess of photons in the experimental data as compared to the Monte Carlo predictions is observed. This excess (uncorrected for the photon detection efficiency) is (1.17 +/- 0.06 +/- 0.27) x 10^{-3} gamma/jet in the specified kinematic region, while the expected level of the inner hadronic bremsstrahlung (which is not included in the Monte Carlo) is (0.340 +/- 0.001 +/- 0.038) x 10^{-3} gamma/jet. The ratio of the excess to the predicted bremsstrahlung rate is then (3.4 +/- 0.2 +/- 0.8), which is similar in strength to the anomalous soft photon signal observed in fixed target experiments with hadronic beams.Comment: 37 pages, 9 figures, Accepted by Eur. Phys. J.

Translocation of exogen phenoloids and alkaloids in acceptor plants -histo- and phytochemical characteristics

Phenoloids with allelopathic effect (juglone, ctaechin, tannin, gallic acid t-cinnamic acid, caffeic acid, coumarin, thymol, salicin in 1mM concentration) cannot be detected after the absorption from the acceptor plant (bean) by the applied selective analytical method (TLC densitometry). Their localisation can be determined by histochemical reagens (ferrichloride, potassium bichromate, sodium hydroxide). In the foliage leaves and excised bean plants they are present mainly in the parenchymatuos elements of the vascular tissue already on the 3rd day, at the beginning of wilting.             Some substances (tropanes) out of the studied allelopathic alkaloids (atropine, scopolamine, belladonnin, tropine and caffeine) can be detected only in small amounts (7-8%) or only in traces in the leaf. Others (e.g. caffeine) accumulate in substantial amount (almost 200%) in their original form. Alkaloids,as well as phenoloids, can be detected in lesf tissue by histochemical methods (Dragendorff and Meyer reagents)