Heavy metal load and dominance hierarchy in juvenile willow tits during winter

Possible links between plasma testosterone levels, heavy metal loads and dominance in juvenile male willow tits (Parus montanus) are studied during winter conditions in Norway. Dominant individuals have better access to food resources, significantly higher cadmium content in the liver and higher plasma testosterone level compared to subordinates. A positive correlation was also found between plasma testosterone level and content of cadmium in the liver. Although the results in our study shows only a limited difference in testosterone level of dominant and subordinate juvenile male willow tits, possible small changes in behaviour might have crucial effects on winter survival of these birds.     

Density dependence and density independence during the early life stages of four marine fish stocks

Recruitment variability caused by density-dependent and density-independent processes is an important area within the study of fish dynamics. These processes can exhibit nonlinearities and nonadditive properties that may have profound dynamic effects. We investigate the importance of population density (i.e., density dependence) and environmental forcing (i.e., density independence) on the age-0 and age-1 abundance of capelin (Mallotus villosus), northeast Arctic cod (Gadus morhua), northeast Arctic haddock (Melanogrammus aeglefinus), and Norwegian spring spawning herring (Clupea harengus) in the Barents Sea. We use statistical methods that explicitly account for nonlinearities and nonadditive interactions between internal and external variables in the abundance of these two pre-recruitment stages. Our results indicate that, during their first five months of life, cod, haddock, and herring experience higher density-dependent survival than capelin. The abundance of age-0 cod depends on the mean age and biomass of the spawning stock, a result which has implications for the management of the entire cod stock. Temperature is another important factor influencing the abundance at age-0 and age-1 of all four species, except herring at age-1. Between age-0 and age-1, there is an attenuation of density-dependent survival for cod and herring, while haddock and capelin experience density dependence at high and low temperatures, respectively. Predation by subadult cod is important for both capelin and cod at age-1. We found strong indications for interactions among the studied species, pointing to the importance of viewing the problem of species recruitment variability as a community, rather than as a population phenomenon.     

The value of routine cervical cultures before transcervical chorionic villus sampling

In 226 women requesting chorionic villus sampling (CVS), routine cervical cultures were obtained before the procedure. Transcervical CVS was performed irrespective of the test results. The prevalence of potential pathogens in cervical cultures at our institution is low. Beta haemolytic Streptococcus was cultured in 3 per cent of the women. No pathogenic microorganisms were isolated in 64 per cent of the women. There was no relationship between culture results and the outcome of pregnancy. These observations suggest that adequate antiseptic cleansing of the genital tract is a suitable approach and there is no need to routinely perform cultures before CVS.     

The ultrasonic detection of an isolated craniosynostosis

The prenatal detection of scaphocephaly, an isolated form of craniosynostosis, is presented. The diagnosis was made at 34 weeks of gestation in a woman with polyhydramnios. The ultrasound appearance and postnatal follow-up are presented.