Arbuscular mycorrhizal fungi and micropropagation of high value crops

Micropropagation has established its position as a way of propagating large numbers of uniform plants. For some plant species that are difficult to propagate by seeds or by conventional cuttings, this technique provides the only possible way of producing high quality plants. Micropropagation is widely used for propagation of high value crops like ornamentals, fruits, vegetables, plantation crops and spices (Vestberg and Estaun 1994). The micropropagation industry was growing fast in Europe up to 1992 (O’Riordain 1992) but after that the micropropagation industry seems to have stabilized its position although a slight increase in production of microplants was still recorded for the period 19…

Near threshold photoproduction of eta mesons off the proton.

We have measured precise total and differential cross sections for the reaction $\ensuremath{\gamma}p\ensuremath{\rightarrow}p\ensuremath{\eta}$ from threshold to 790 MeV at the MAMI accelerator in Mainz with the neutral meson spectrometer TAPS. Resonance parameters of the ${S}_{11}$(1535) resonance and the electromagnetic coupling $\ensuremath{\gamma}p\ensuremath{\rightarrow}{S}_{11}$ have been extracted from the data. Contributions from the ${D}_{13}$(1520) resonance to $\ensuremath{\eta}$ photoproduction in the threshold region have been identified for the first time via interference terms in the angular distributions.

Krusche et al. reply.

Exclusive πo- and η-meson production in 40Ar + natCa at 800A MeV

Abstract The impact-parameter dependence of π o - and η-meson production is reported for the system 40 Ar+ nat Ca at a beam energy of 800 A MeV. Scaling of the meson abundances with the transverse mass is observed. The experimental results are compared to calculations within the BUU model.

Mass and Γ3π0/Γγγ decay branching ratio of theη-meson from the p(γ, η)p reaction

Near threshold photoproduction ofη-mesons from the proton has been measured at the MAMI accelerator with the TAPS spectrometer. The mass of theη-meson was deduced from the threshold energy forη-photoproduction. The result of m η =(547.12 ± 0.06 ± 0.25) MeV supports the low value of theη-mass reported from a dp →3Heη measurement at SATURNE in 1992. Theη-decay branching ratio Γ3π0/Γγγ was measured to be (0.832±0.005±0.012).

Detection of charged pions and protons in the segmented electromagnetic calorimeter TAPS

We present the characteristics of the segmented BaF2 calorimeter TAPS for the measurement of charged pions and protons. The method of particle identification exploits the relation between the kinetic energy of a particle, its mass and the time-of-flight required to reach the detector. The detection efficiency is calculated using GEANT-GCALOR simulations. The analysis method is applied in the reaction Ar-40 + Ca-nat at 0.8A GeV. The simultaneous detection of charged pions and protons can be used to search for correlated pairs signalling the de-excitation of the Delta(1232) resonance. (C) 1998 Elsevier Science B.V. All rights reserved.