Conspicuous visual signals do not coevolve with increased body size in marine sea slugs.

Many taxa use conspicuous colouration to attract mates, signal chemical defences (aposematism) or for thermoregulation. Conspicuousness is a key feature of aposematic signals, and experimental evidence suggests that predators avoid conspicuous prey more readily when they exhibit larger body size and/or pattern elements. Aposematic prey species may therefore evolve a larger body size due to predatory selection pressures, or alternatively, larger prey species may be more likely to evolve aposematic colouration. Therefore, a positive correlation between conspicuousness and body size should exist. Here, we investigated whether there was a phylogenetic correlation between the conspicuousness of animal patterns and body size using an intriguing, understudied model system to examine questions on the evolution of animal signals, namely nudibranchs (opisthobranch molluscs). We also used new ways to compare animal patterns quantitatively with their background habitat in terms of intensity variance and spatial frequency power spectra. In studies of aposematism, conspicuousness is usually quantified using the spectral contrast of animal colour patches against its background; however, other components of visual signals, such as pattern, luminance and spectral sensitivities of potential observers, are largely ignored. Contrary to our prediction, we found that the conspicuousness of body patterns in over 70 nudibranch species decreased as body size increased, indicating that crypsis was not limited to a smaller body size. Therefore, alternative selective pressures on body size and development of colour patterns, other than those inflicted by visual hunting predators, may act more strongly on the evolution of aposematism in nudibranch molluscs.

Internet-based self-management compared with usual care in adolescents with asthma: a randomized controlled trial.

INTRODUCTION: Asthma control often is poor in adolescents and this causes considerable morbidity. Internet-based self-management (IBSM) improves asthma-related quality of life in adults. We hypothesized that IBSM improves asthma-related quality of life in adolescents. METHODS: Adolescents (12-18 years) with persistent and not well-controlled asthma participated in a randomized controlled trial with 1 year follow-up and were allocated to IBSM (n = 46) or usual care (UC, n = 44). IBSM consisted of weekly asthma control monitoring with treatment advice by a web-based algorithm. Outcomes included asthma-related quality of life (Pediatric Asthma Quality of Life Questionnaire, PAQLQ) and asthma control (Asthma Control Questionnaire, ACQ) and were analyzed by a linear mixed-effects model. RESULTS: At 3 months, PAQLQ improved with 0.40 points (95% CI: 0.17-0.62, P < 0.01), by IBSM compared to 0.0 points for UC (P = 0.02 for the difference). At 12 months the between-group difference was -0.05 (95% CI: -0.50 to 0.41, P = 0.85). At 3 months ACQ improved more in IBSM than in UC (difference: -0.32 points; 95% CI: -0.56 to -0.079, P < 0.01). At 12 months the difference was -0.05 (95% CI: -0.35 to 0.25, P = 0.75). CONCLUSION: IBSM improved asthma-related quality of life and asthma control in adolescents with not well-controlled asthma after 3 months, but not after 12 months.