Search with the ATLAS detector for new physics with significant missing transverse energy and two isolated leptons

Results of searches for supersymmetry in events with significant missing transverse energy and two isolated leptons with the ATLAS experiment at the LHC are presented. Three analyses are presented here, the first two are analyses with leptons of opposite charge and same charge, respectively. The third one is an analysis that searches for an excess of same-flavour opposite-charge lepton pairs over those of different-flavour. Data corresponding to an integrated luminosity of 1 fb^?1 are analysed.     

Probability Density Function of the Output Current of Cascaded Multiplexer/Demultiplexers in Transparent Optical Networks

The influence of the concatenation of arbitrary optical multiplexers/demultiplexers (MUX/DEMUXs) on the probability density function (PDF) of the output current of a transparent optical network is assessed. All PDF results obtained analytically are compared with estimates from Monte Carlo simulation and an excellent agreement is achieved.

The non-Gaussian behavior of the PDFs, previously reported by other authors for square-law detectors, is significantly enhanced with the number of nodes increase due to the noise accumulation along the cascade of MUX/DEMUXs. The increase of the MUX/DEMUXs bandwidth and detuning also enhances the PDFs non-Gaussian behavior. The PDF shape variation with the detuning depends strongly on the number of nodes.

Explanations for the Gaussian approximation (GA) accuracy on the assessment of the performance of a concatenation of optical MUX/DEMUXs are also provided. For infinite extinction ratio and tuned MUX/DEMUXs, the GA error probabilities are, in general, pessimistic, due to the inaccurate estimation of the error probability for both bits. For low extinction ratio, the GA is very accurate due to a balance between the error probabilities estimated for the bits “1” and “0.” With the detuning increase, the GA estimates can become optimistic.     

Focusing mutations into the P. fluorescens esterase binding site increases enantioselectivity more effectively than distant mutations

Rational design of enzymes with improved properties, such as enantioselectivity, usually focuses mutations within the substrate binding site. On the other hand, directed evolution of enzymes usually targets the entire protein and discovers beneficial mutations far from the substrate binding site. In this paper, we propose an explanation for this discrepancy and show that a combined approach--random mutagenesis within the substrate binding site--is better. To increase the enantioselectivity (E) of a Pseudomonas fluorescens esterase (PFE) toward methyl 3-bromo-2-methylpropionate, we focused mutagenesis into the substrate binding site at Trp28, Val121, Phe198, and Val225. Five of the catalytically active mutants (13%) showed better enantioselectivity than wild-type PFE. The increases in enantioselectivity were higher (up to 5-fold, reaching E = 61) than with mutants identified by random mutagenesis of the entire enzyme.     

Bestimmung des Titans und Zirkoniums, ihre Trennung von anderen Elementen sowie von einander

Ohne Zusammenfassung     

Ueber die in einem mittelst Schwefels?ure getrockneten Gase noch enthaltene Menge Feuchtigkeit

Ohne Zusammenfassung749 Republic Street, Cleveland Ohio, U. S. A., 25. Mai 1885.     

Hydrodynamical model of electron-positron annihilation into hadrons

Landau's hydrodynamical model of multiparticle production is formulated for e⁺e^? → hadrons at center-of-momentum energies 10 GeV and higher. An analytical solution to the problem of spherical expansion of a relativistic fluid is presented. When hadrons condense out at the last stage of expansion, fluid thermal motion is taken into account. We derive predictions for multiplicities, average secondary energies and inclusive single particle distributions for various secondary hadrons; these results are then compared to other models. Finally, we investigate the internal consistency of the model.     

Symmetric function means of positive operators

Many authors have studied means involving ratios of the elementary symmetric functions. This work involves generalizing these means to an operator theoretic setting, and extending many of the classical scalar inequalities to operators. It is shown that these operator means are related to electrical networks.     

Studies on the biological activity of some nitrothiophenes

The biological activity of nineteen substituted thiophenes (3) have been assessed by evaluating the minimum inhibitory concentration required to inhibit the growth of E. coli, M. luteus and A. niger. The series displays a wide range of activities with 2-chloro-3,5-dinitrothiophene (3a) or 2-bromo-3,5-dinitrothiophene (3c) showing the highest activity against all three organisms, while the simplest compound of the series, 2-nitrothiophene (3s) shows the smallest activity in each case. The mode of action of 3a and 3c is thought to involve nucleophilic attack by intracellular thiols at the 2-position of the heterocyclic ring leading to displacement of halogen, but other active derivatives, such as 2,4-dinitrothiophene (3h) and 5-nitrothiophene-2-carbaldehyde (3d) which have no displaceable halogen or leaving group are thought to act by forming Meisenheimer complexes.