Modelling and interpreting fish bioenergetics: a role for behaviour, life-history traits and survival trade-offs.

Bioenergetics is used as the mechanistic foundation of many models of fishes. As the context of a model gradually extends beyond pure bioenergetics to include behaviour, life-history traits and function and performance of the entire organism, so does the need for complementing bioenergetic measurements with trade-offs, particularly those dealing with survival. Such a broadening of focus revitalized and expanded the domain of behavioural ecology in the 1980s. This review makes the case that a similar change of perspective is required for physiology to contribute to the types of predictions society currently demands, e.g. regarding climate change and other anthropogenic stressors.

Short-term dominance: stability and consequences for subsequent growth.

Dominance status was determined among groups of four fish by using individuals from eight brown trout Salmo trutta populations. Subsequent growth of the fish was later recorded in larger groups. Seven months after the first set of trials, an additional set of dominance trials was performed by using the same fish. Social status affected subsequent growth; individuals having the lowest ranks grew less when compared to the higher ranking fish. Furthermore, the short term dominance hierarchy was rather stable between the two trials. This was especially the case with the lowest ranking fish, which tended to remain in the lowest position also in the second trial. The results suggest that the short term dominance trials done among few conspecifics reflect relatively well not only the subordinates' relative but also absolute social status.

Radiographic examinations as an aid to orthodontic diagnosis and treatment planning.

Seventy consecutive adolescents were examined to evaluate radiographic examinations as an aid to orthodontic diagnosis and treatment planning in combination with clinical examination. The clinical examination included dental impressions and extra- and intraoral photographs. The radiographic examination comprised a panoramic radiograph, a lateral cephalogram and six intraoral anterior periapical radiographs. Initially, only records from the clinical examination were used for diagnosis and treatment planning. If required, the dentist could choose any of the radiographs to accomplish the task. The number of radiographs ordered, the sequence of ordering and any change in diagnosis and treatment plan caused by the radiographs were registered. In 29% of the cases the initial diagnosis, based on the clinical examination, study models and photographs, coincided with the final diagnosis. In 93% of all cases the initial treatment plan coincided with the final one. Although the panoramic examination was the most common choice, it had only a minor effect on diagnostic and treatment decisions, while the cephalometric examination had a major impact on the diagnosis. In most cases the clinical examination, supplemented with study models and photographs, can provide adequate information for orthodontic treatment planning. The result stresses the importance of using individually based selection criteria for radiographic examination in order to prevent radiographs being obtained routinely.