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Article
Specular and Off-Specular X-Ray Scattering as Quantitative Structural Probes of Multilayers. Application to MN/IR(111) Superlattices
Diffuse scattering of X rays is a particularly useful tool for studying interface and surface defects in single layer films. We have extended this technique to the study of multilayers. The samples are Mn/Ir(1...
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Article
Design and validation of a partial-genome microarray for transcriptional profiling of the Bradyrhizobium japonicum symbiotic gene region
The design and use of a pilot microarray for transcriptome analysis of the symbiotic, nitrogen-fixing Bradyrhizobium japonicum is reported here. The custom-synthesized chip (Affymetrix GeneChip®) features 738 gen...
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Article
Photoproduction of positive pions from hydrogen at large angles in the energy range 0.3–2.0 GeV
The differential cross-section for the reaction γp↦π + n was measured using the bremsstrahlung beam of the Bonn 2.5 GeV electron synchrotron. The pions were detected and momentum analysed in a multichannel magnet...
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Article
GroEL chaperonins are required for the formation of a functional nitrogenase in Bradyrhizobium japonicum
At least five highly conserved, but disparately regulated groESL operons are present in Bradyrhizobium japonicum. Expression of groESL 3 is coregulated with symbiotic nitrogen fixation g...
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Chapter
Integration of Regulatory Networks for Different Physiological Functions in Bradyrhizobium Japonicum
Two signal transduction cascades in B. japonicum, the FixLJ-FixK2 and the RegSR-NifA cascades, respond to micro-oxic conditions and mediate the expression of genes and operons concerned with microaerobic respirat...
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Article
Determination of the production rate of D*0 mesons and of the ratio V/(V+P) in \(Z^0 \to c\bar c\) decays
In e+e2212 collisions at centre-of-mass energies around 91 GeV, D*0 mesons have been reconstructed using data collected with the OPAL detector at LEP. The hadronisation fraction has been measured to be f(c→D*0)=0...
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Article
A search for neutral Higgs bosons in the MSSM and models with two scalar field doublets
A search is described for the neutral Higgs bosons h0 and A0 predicted by models with two scalar field doublets and, in particular, the Minimal Supersymmetric Standard Model (MSSM). The search in the Z0h0 and h0A
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Article
Multi-photon final states in e+e− collisions at ∝s =130-172 GeV
The process e+e− →, γγ(γ) is studied using data recorded with the OPAL detector at LEP. The data sample corresponds to a total integrated luminosity of 25.38 pb−1 taken at centre-of-mass energies of 130–172 GeV. ...
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Article
Search for unstable heavy and excited leptons in e+e− collisions at ∝s = 170-172 GeV
We have searched for unstable neutral and charged heavy leptons, N and L±, and for excited states of neutral and charged leptons, ν* e*, μ* and τ*, in e+e− collisions at centre-of-mass energies of 170 and 172 GeV...
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Article
Search for a massive Di-photon resonance at ∝s = 91 – 172 GeV
A search for the resonant production of high mass photon pairs associated with a leptonic or hadronic system has been performed using a total data sample of 25.7 pb−1 taken at centre-of-mass energies between 130 ...
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Article
Σ+, Σ0 and Σ− hyperon production in hadronic Z0 decays
The production rates of the $J_{P}={1⩈er 2}^{+}$ octet Σ baryons in hadronic Z0 decays have been measured using the OPAL detector at LEP. The inclusive production rates per hadronic Z0 decay of the three isospin ...
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Article
A measurement of the charm and bottom forward-backward asymmetries using D mesons at LEP
A measurement of the charm and bottom forward-backward asymmetry in e+e− annihilations is presented at energies on and around the peak of the Z0 resonance. Decays of the Z0 into charm and bottom quarks are tagged...
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Article
The dnaKJ operon belongs to the σ32-dependent class of heat shock genes in Bradyrhizobium japonicum
The dnaKJ genes of Bradyrhizobium japonicum were cloned and sequenced. They map adjacent to each other, as in other proteobacteria of the α and γ subgroups. Primer extension experiments identified two strongly h...
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Chapter and Conference Paper
Genetic Regulation and Bioenergetics of Symbiotic Nitrogen Fixation in Bradyrhizobium japonicum
The low free oxygen concentration (< 25 nM) within soybean root nodules leads to two consequences that are relevant for this report: (i) it induces the synthesis of a high-affinity terminal oxidase that enable...
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Article
A measurement of the B d 0 oscillation frequency using leptons and D*± mesons
Data collected with the OPAL detector during 1990–1994 are used to measure the time dependence of $$B_d^0 \leftrightarrow \bar B_d^0 ...
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Article
A precise measurement of the tau polarization and its forward-backward asymmetry at LEP
A measurement of theτ lepton polarization and its forward-backward asymmetry at the Z0 resonance using the OPAL detector is described. The measurement is based on analyses of τ→ρντ, ττπ(K)ντ,
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Article
Multiplicity dependence of Bose-Einstein correlations in hadronic Z0 decays
Bose-Einstein correlations between like charged track pairs have been studied using a sample of approximately 3.6 million multihadronic Z0 decays collected with the OPAL detector at LEP. The radius of the emittin...
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Article
QCD studies with e+e− annihilation data at 130 and 136 GeV
We have studied hadronic events produced at LEP at centre-of-mass energies of 130 and 136 GeV. Distributions of event shape observables, jet rates, momentum spectra and multiplicities are presented and compare...
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Article
Upper limit on theν τ mass fromτ → 3hν τ decays
A new technique has been used to determine a limit on theν τ mass using Z0→τ + τ − events selected from 140 pb−1
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Article
Search for a narrow resonance in Z0 decays into hadrons and isolated photons
A search for the hadronic decay of a hypothetical resonance S0 in the process e+e−→γ + hadrons at Z0 energies is reported. Particular care is taken to optimise the sensitivity to a scalar resonance decaying into ...
