Ising model of polarity formation in molecular crystals: from the growth model to the asymptotic equilibrium state.

We analyze a layer-by-layer growth model of crystals consisting of dipolar molecules with two directional states. The model is characterized by the assumption of thermal equilibrium formation of new adlayers, whereas previous layers are treated as being "frozen" in the state in which they were formed. Longitudinal and transverse Ising-type nearest neighbor interactions are taken into account. Under such assumptions, bulk polarization is known to arise. We mainly consider asymptotic one- and two-layer statistics after many steps of growth; we have obtained a theorem relating this statistics to thermal equilibrium of an appropriate two-layer system. Local polarization patterns resembling those of ferromagnetism and antiferromagnetism emerge, depending on signs and magnitudes of the coupling constants. We have explored such effects by means of simulations, by a mean field approximation, and by a Bethe-Peierls analysis.

Transmission of opportunistic pathogens in a veterinary teaching hospital.

Acinetobacter baumannii, Enterococcus faecalis, Enterococcus faecium, and Staphylococcus intermedius isolates from infected surgical wounds and other types of infections in a veterinary teaching hospital were typed by pulsed field gel electrophoresis. A first cluster of infections with a multiresistant A. baumannii strain was observed in dogs and cats in 1998-1999. This strain disappeared after cleaning and disinfection of the companion animals intensive care unit. It was followed in 2000 by a second multiresistant strain, which caused another cluster of infections and was also transmitted to a patient in the nearby horse clinic. Transmission of a multiresistant E. faecium strain between two cats with surgical wound infections was also observed during the same period. No multiresistant S. intermedius strain was observed during this time and transmission of this organism between patients did not seem to occur. The present study demonstrates the potential for hospital nosocomial resistance problems in veterinary medicine similar to those encountered in human medicine. The results suggest that the epidemiology of nosocomial infections with A. baumannii and E. faecium may differ from that of S. intermedius infections and that preventive measures may have to be adapted to the problem organism.

Interactions of a history of migration with the course of pain disorder.

OBJECTIVE: Previous studies indicate that sociocultural factors affect the course of pain disorder. We investigated the role of nationality as an indicator of cultural factors, and of the degree of inclusion (DI) in Swiss society as an indicator of the migration process on the course of pain disorder. METHOD: In a semiprospective case-control study, outcome was assessed after a 2-year follow-up in 57 patients treated for pain disorder by phone interview with the patients. One Swiss patient was matched with two Spanish or Italian patients living in Switzerland. Patients' appraisal of course of illness (PACI) and of current general health (PACGH) were assessed as the sum score of their ratings of general well-being, handicap in everyday life, work ability, mood and pain. Family physicians were also asked to rate patient's course of illness. DI in Swiss society was assessed according to type of work permit, age at immigration and fluency in the language of the receiving country. RESULTS: Swiss patients evaluated their PACI [H(1,56) = 4.30; P = .0038] and PACGH [H(1,56) = 9.04; P = .003)] more favourably than patients from Italy and Spain. This difference was confirmed by the family physician's evaluation of the course of illness. A similar difference in outcome was found in favour of foreign patients with a higher DI. CONCLUSION: These results indicate that, in addition to sociocultural factors, the DI affects the outcome of pain disorder in patients with a history of migration.

Systematic effects of participant role on evaluation of the psychotherapy session.

This study identified systematic differences between therapists (n = 114) and patients (n = 119) in the process components that predict evaluation of psychotherapy sessions. The Comprehensive Scale of Psychotherapy Session Constructs was developed to measure 9 process variables and their relationships to session evaluation from the perspectives of therapist and patient. Regression equations predicting session evaluation from the process components for the 2 groups were significantly different. Therapist session evaluation was best predicted by therapist expertness, and patient session evaluation was best predicted by the therapist real relationship. The therapist real relationship negatively predicted therapist session evaluation when all process variables were considered simultaneously. Patient progress and patient involvement significantly and positively predicted both therapist and patient evaluation.