Scattering of polarised protons by Ni, Sr, Cd, In and Sn isotopes. II. Inelastic scattering-collective analysis

For pt.I see ibid., vol.15, no.2, p.181 (1989). Inelastic scattering of polarised protons (Ep=20.4, 24.6 MeV) by 60,64Ni, 86,88Sr, 110,112,114Cd, 115In and 116,118,120,122,124Sn has been investigated. Except for the case of 60Ni, only for the 21+ and 31- states could statistically reliable data be obtained. The data have been analysed with the DWBA employing a collective form factor. The agreement between experiment and theory is fairly good, although the experimental data tend to exhibit somewhat more structure than the theory predicts. For 60Ni also data for higher excited states have been obtained. These have been analysed with moderate success by coupled-channels calculations. The deformation parameters found for the Sn isotopes can be described in terms of the IBA model. Some suggestions for the applications of the IBA model in inelastic scattering are given

The (p,d) reaction on 58Ni and 56Fe at 24.6 MeV

The (p,t) reaction on 56Fe and 58Ni initiated by 24.6 MeV polarised protons has been investigated. The reaction process is described in terms of simultaneous and sequential neutron transfer. For all five final states studied the sequential process competes strongly with simultaneous transfer of a neutron pair. Theoretical values for the spectroscopic amplitudes were derived from shell-model wavefunctions; these seem to give a reliable description of the reaction process

The (p,d) reaction on 56Fe at 24.6 MeV

The authors have studied the (p,d) reaction on 56Fe, initiated by a 24.6 MeV polarised proton beam. Cross sections and analysing powers were obtained for nine states in the final nucleus 55Fe. These were compared with DWBA and CRC calculations, confirming spin and parity assignments. As opposed to the situation in 58Ni(p,d) no large two-step contributions were necessary for obtaining agreement with calculations

Immunity to Campylobacter: its role in risk assessment and epidemiology

Acquired immunity is an important factor in the epidemiology of campylobacteriosis in the developing world, apparently limiting symptomatic infection to children of less than two years. However, also in developed countries the highest incidence is observed in children under five years and the majority of Campylobacter infections are asymptomatic, which may be related to the effects of immunity and/or the ingested doses. Not accounting for immunity in epidemiological studies may lead to biased results due to the misclassification of Campylobacter-exposed but apparently healthy persons as unexposed. In risk assessment studies, health risks may be overestimated when immunity is neglected