A novel model concept for modelling the leaching of natural toxins: results for the case of ptaquiloside.

Phytotoxins are a large class of highly diverse emerging environmental contaminants that have been detected at high concentrations in plants, water and soils. This study presents a novel modelling approach for assessing the fate of plant toxins in the soil-plant-atmosphere continuum, developed for the specific case of ptaquiloside (PTA), a carcinogenic phytotoxin produced by Pteridium aquilinum. The mechanistic model DAISY has been adapted for reproducing phytotoxin dynamics in plants, covering processes such as toxin generation in the canopy, wash off by precipitation and toxin recovery in the canopy after depletion events. Transport of the toxin in the soil was simulated by the advection-dispersion equation assuming weak sorption and degradation for two Danish soils. The model simulates realistic toxin contents in the plant during the growing season, where the actual PTA content is dynamic and a function of the biomass. An average of 48% of the PTA produced in the canopy is washed off by precipitation, with loads in the soil often in the order of mg m-2 and up to a maximum of 13 mg m-2 in a single rain event. Degradation in the soil removes 99.9% of the total PTA input to the soil, while only 0.1% leaches into the soil. The median annual flux-averaged predicted environmental concentrations during single events are often in the order of µg L-1, reaching up to 60 µg L-1 for the worst-case scenario. The simulated results for both degradation and wash off are of the same order of magnitude as the published data. Based on the results, we conclude that DAISY, with the newly implemented processes, is a useful tool for understanding, describing and predicting the fate of PTA in the soil. Further work comparing the model results with real data is needed for the calibration and validation of the model.

[The establishment of the "dollhouse" at Oslo hospital]. / Etableringen av Oslo Hospitals dollhus.

The "Dollhouse" at Oslo Hospital was established in 1778 in a municipal institution built in 1538 to serve poor people that had become struck by illness. A medical doctor cared for the insane inmates' somatic ailments and a priest for the needs of the soul. However, from the beginning of the nineteenth century the medical view came to dominate. The first Norwegian law concerning "The Treatment and Care of the Insane" was approved in 1848, co-authored by the first medical superintendent at Oslo Hospital, Herman Wedel Major, the first institutional psychiatrist in Norway. The Oslo Hospital is still in operation, now for both sexes as part of the community-run psychiatric services in Oslo.

Simultaneous depression.

Five different strategies were used to detect cases in which depressed behaviour occurred in both spouses within the same time period (simultaneous depression). Among 7068 references on depression in the literature, only one referred to a case of simultaneous depression. Of 8008 registered individuals hospitalized in Norway from 1961-1971, none had simultaneous depression. A search of the total Scandinavian population (17.5 million) revealed only one case. The authors suggest that the result is caused by specific communication values attached to depressed behaviour and compensatory mechanisms in depressed couple relationships. The need for assessments that include the identified patient's family system in the planning of treatment for depression is discussed, with the aim to prevent cases of successful mistreatment in which the identified patient is cured while the spouse becomes depressed or commits suicide.

A systems theory approach to a case of anorexia nervosa.

Systems theory views mental and psychosomatic illness as the natural consequences of a dysfunctional human interactional group. The symptom chosen is affected by the symptom carrier's age, sex, and unique individual characteristics. However, the reason the symptom develops and is maintained is to be found in the system(s) of which the symptom carrier is a part. A human system consist of two or more individuals who have an ongoing, often goal-directed, relationship with each other. The most important human system today is undoubtedly the family. The welfare of the individual is usually related to membership in a vital, well-adjusted family. A dysfunctional family easily becomes dependent on mental or behavioral deviations in one of its members as a means of preventing disintegration. We hope this article's description of a typical treatment situation will demonstrate how a systems theory approach differs from other forms of family therapy in its evaluations and techniques.