Stefan van Dongen

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What factors determine the persistence of species in fragmented habitats? To address this question, we studied the relative impacts of forest deterioration and fragmentation on bird species in 12 rainforest fragments in Kenya, combining 6 years of individual capture-recapture data with measurements of current captures and museum specimens. Species mobility,(More)
There is growing evidence from both experimental and non-experimental studies that fluctuating asymmetry does not consistently index stress or fitness. The widely held--yet poorly substantiated--belief that fluctuating asymmetry can act as a universal measure of developmental stability and predictor of stress-mediated changes in fitness, therefore staggers.(More)
Developmental instability (DI) is the sensitivity of a developing trait to random noise and can be measured by degrees of directionally random asymmetry [fluctuating asymmetry (FA)]. FA has been shown to increase with loss of genetic variation and inbreeding as measures of genetic stress, but associations vary among studies. Directional selection and(More)
The second to fourth digit ratio (2D:4D) is smaller in human males than in females and hence this trait is sexually dimorphic. The digit ratio is thought to be established during early prenatal development under the influence of prenatal sex hormones. However, the general assumption of early establishment has hardly been studied. In our study, we analyzed(More)
OBJECTIVE To determine the long-term safety and effectiveness of risperidone for severe disruptive behaviors in children. METHOD A multisite, 1-year, open-label study of patients aged 5 to 14 years with disruptive behaviors and subaverage intelligence was conducted. RESULTS Seventy-three percent of the 504 patients enrolled completed the study. The mean(More)
It has been suggested that fluctuating asymmetry (FA) reflects an animal's ability to cope with the sum of challenges during its growing period and, thus, is a potential welfare indicator. In this review we investigate the evidence of associations between FA and other welfare indicators measured at the level of the individual and of effects of(More)
Domestic fleas were collected in 12 villages in the western Usambara Mountains in Tanzania. Of these, 7 are considered villages with high plague frequency, where human plague was recorded during at least 6 of the 17 plague seasons between 1986 and 2004. In the remaining 5 villages with low plague frequency, plague was either rare or unrecorded. Pulex(More)
BACKGROUND Fluctuating asymmetry (FA), reflecting developmental instability (DI), may honestly signal individual quality and relate to human attractiveness and measures of sexual behaviour. The evolutionary importance of these associations, however, critically depends on the role of DI in driving these correlations. A direct effect of FA reduces the role of(More)
Deviations of genotype distribution from Hardy-Weinberg expectations within a (sub)population can give valuable insight into the population structure, and can be quantified by means of F(is) values. Specific biological and/or genetical hypotheses regarding F(is) require particular statistical procedures to be able to perform the test with high power. The(More)
Whether fluctuating asymmetry (FA) provides a useful metric indicator of the degree of environmental stress experienced by populations is still a contentious issue. We investigated whether the degree of FA in skeletal elements is useful in elucidating the degree of environmental stress experienced by frog populations, and further, tested the proposition(More)