RESUMO
We compare the calculation of time-dependent quantum expectation values performed in different ways. In one case, they are obtained from an integral over a function of the probability density, and in the other case, the integral is over a function of the probability flux density. The two kinds of coordinate-dependent integrands are very different in their appearance, but integration yields identical results, if the exact wave function enters into the computation. This can be different, if one applies approximations to the wave function. For illustration, we treat one- and two-dimensional dynamics in coupled electron-nuclear systems. Using the adiabatic expansion of the total wave function, the expectation values are decomposed into different contributions. This allows us to discuss the validity of the Born-Oppenheimer (BO) approximation applied to the calculation of the expectation values from probability density- and flux density- integrals. Choosing force- and torque operators as examples, we illustrate the different spatiotemporal characteristics of the various integrands.
RESUMO
Listeria monocytogenes is a foodborne bacterial pathogen. Immunocompromised patients are at higher risk of developing invasive listeriosis with high fatality rates. After notification of two patients with Listeria that had stayed in the same hospital (hospital A) before the onset of infection, we began an investigation to ascertain the extent of the outbreak, identify its source and prevent further infections. We conducted active case finding by contacting hospital A, reviewing medical records and retrospectively investigating listeriosis notifications from the German surveillance system (SurvNet). The kitchen (hospital A) and its meat supplier (company X) were inspected and environmental and food samples were taken for microbiological testing. All isolates of L. monocytogenes, together with patient and food-related isolates from Baden-Württemberg 2006 to 2008, were characterised by pulsed-field gel electrophoresis (PFGE). Altogether, 16 cases of listeriosis were identified. Serotype 4b with the indistinguishable PFGE patterns (AscI 17a/ApaI 10) was detected from nine patients, five environmental and three ready-to-eat scalded sausage samples from company X, and two food samples from hospital A. All 11 patient cases linked to hospital A were immunosuppressed and were regularly served food during their hospital stay. Ten of these patients received corticosteroids and proton pump inhibitors (PPIs). Five cases were fatal. Our investigations indicate that ready-to-eat scalded sausages from company X caused this outbreak of listeriosis. Hospital food suppliers should guarantee the absence of L. monocytogenes in ready-to-eat meat products, controlled through optimised quality assurance.
