Limits on the production of scalar leptoquarks from Z (0) decays at LEP

A search has been made for pairs and for single production of scalar leptoquarks of the first and second generations using a data sample of 392000 Z0 decays from the DELPHI detector at LEP 1. No signal was found and limits on the leptoquark mass, production cross section and branching ratio were set. A mass limit at 95% confidence level of 45.5 GeV/c2 was obtained for leptoquark pair production. The search for the production of a single leptoquark probed the mass region above this limit and its results exclude first and second generation leptoquarks D0 with masses below 65 GeV/c2 and 73 GeV/c2 respectively, at 95% confidence level, assuming that the D0lq Yukawa coupling alpha(lambda) is equal to the electromagnetic one. An upper limit is also given on the coupling alpha(lambda) as a function of the leptoquark mass m(D0)

Structural studies on nonlinear optical materials

SIGLEAvailable from British Library Document Supply Centre- DSC:D96816 / BLDSC - British Library Document Supply CentreGBUnited Kingdo

Structural insights of RmXyn10A – A prebiotic-producing GH10 xylanase with a non-conserved aglycone binding region

Hydrolysis of arabinoxylan (AX) by glycoside hydrolase family 10 (GH10) xylanases produces xylo- and arabinoxylo-oligosaccharides ((A)XOS) which have shown prebiotic effects. The thermostable GH10 xylanase RmXyn10A has shown great potential to produce (A)XOS. In this study, the structure of RmXyn10A was investigated, the catalytic module by homology modelling and site-directed mutagenesis and the arrangement of its five domains by small-angle X-ray scattering (SAXS). Substrate specificity was explored in silico by manual docking and molecular dynamic simulations. It has been shown in the literature that the glycone subsites of GH10 xylanases are well conserved and our results suggest that RmXyn10A is no exception. The aglycone subsites are less investigated, and the modelled structure of RmXyn10A suggests that loop ß6?6 in the aglycone part of the active site contains a non-conserved ?-helix, which blocks the otherwise conserved space of subsite +2. This structural feature has only been observed for one other GH10 xylanase. In RmXyn10A, docking revealed two alternative binding regions, one on either side of the ?-helix. However, only one was able to accommodate arabinose-substitutions and the mutation study suggests that the same region is responsible for binding XOS. Several non-conserved structural features are most likely to be responsible for providing affinity for arabinose-substitutions in subsites +1 and +2. The SAXS rigid model of the modular arrangement of RmXyn10A displays the catalytic module close to the cell-anchoring domain while the carbohydrate binding modules are further away, likely explaining the observed lack of contribution of the CBMs to activity. © 2017 The AuthorsVINNOVA Svenska Forskningsrådet Formas: 2015-769 VINNOVA Sixth Framework Programme: RII3/CT/2004/5060008 Vetenskapsrådet: 2014-5038This work was supported by VINNOVA via the Lund University Antidiabetic Food Centre (VINN Excellence Centre), by the Swedish Research Council (VR) [grant no. 2014-5038 ], and by the Swedish Research Council Formas [grant no. 2015-769 ]. Also to enable us to use the DESY-EMBL beamlines we are grateful for financial support from the European Community – Research Infrastructure Action under the FP6 ?Structuring the European Research Area Programme” contract number RII3/CT/2004/5060008. The GROMACS simulations were performed on resources provided by the Swedish National Infrastructure for Computing (SNIC) at LUNARC (SNIC-2017/1-361). Björn Stenqvist, Lund University, is thanked for his computational assistance. Appendix

Electroweak measurements in electron–positron collisions at w-boson-pair energies at lep

Contains fulltext : 121524.pdf (preprint version ) (Open Access

THE EUROPEAN HYBRID SPECTROMETER

The final version of the European hybrid spectrometer (EHS) is described. EHS was used in the NA27 experiment to study charm particles produced in View the MathML source interactions. A rapid cycling, high resolution bubble chamber (LEBC) produced bubbles of 17 \u3bcm diameter which were measured with a precision of 2.5 \u3bcm. Short-lived charm particles are observed with an efficiency up to 90% (D\ub1). The spectrometer accepts 70% of all particles produced, including approximately 100% of those in the forward hemisphere and the momenta of charged particles are measured to better than 1% over the whole momentum range. The charged particle identification detectors give information on 84% of the spectrometer tracks, half of which obtain unique identification. Two lead glass detectors measure the energy of electromagnetic showers such that the \u3c00 mass distribution has a fwhm of View the MathML source. Hadronic showers are measured with two iron/scintillator calorimeters. The mass resolutions are 3.0, 0.9 and 11 View the MathML source for K0, \u39b0 and D 12 charged particles respectively. The D0 mass is measured to be (1865.1 \ub1 1.8 \ub1 0.8