Evolutionary responses to climate change in a range expanding plant.

To understand the biological effects of climate change, it is essential to take into account species' evolutionary responses to their changing environments. Ongoing climate change is resulting in species shifting their geographical distribution ranges poleward. We tested whether a successful range expanding plant has rapidly adapted to the regional conditions in its novel range, and whether adaptation could be driven by herbivores. Furthermore, we investigated if enemy release occurred in the newly colonized areas and whether plant origins differed in herbivore resistance. Plants were cloned and reciprocally transplanted between three experimental sites across the range. Effects of herbivores on plant performance were tested by individually caging plants with either open or closed cages. There was no indication of (regional) adaptation to abiotic conditions. Plants originating from the novel range were always larger than plants from the core distribution at all experimental sites, with or without herbivory. Herbivore damage was highest and not lowest at the experimental sites in the novel range, suggesting no release from enemy impact. Genotypes from the core were more damaged compared to genotypes from newly colonized areas at the most northern site in the novel range, which was dominated by generalist slug herbivory. We also detected subtle shifts in chemical defenses between the plant origins. Genotypes from the novel range had more inducible defenses. Our results suggest that plants that are expanding their range with climate change may evolve increased vigor and altered herbivore resistance in their new range, analogous to invasive plants.

Stress management and mind-body medicine: a randomized controlled longitudinal evaluation of students' health and effects of a behavioral group intervention at a middle-size German university (SM-MESH).

BACKGROUND: Student life can be stressful. Hence, we started a regular mind-body medical stress management program in 2006. By today, more than 500 students took part and evaluations showed significant results, especially with regard to a reduction of stress warning signals. For further analysis, we now decided to run a randomized controlled longitudinal trial. METHODS: Participating students at Coburg University were randomized into an intervention (n = 24) or a waitlist control group (n = 19). The intervention group completed 3 sets (pre/post/follow-up) and the control group 2 sets (pre/post) of self-administered questionnaires. The questionnaires included: SF-12 Health Survey, Perceived Stress Scale (PSS), Sense of Coherence (SOC-L9), Visual Analogue Scale (VAS) concerning stress, and the Stress Warning Signs (SWS) scale. Randomly selected participants of the intervention group were also queried in qualitative interviews. The intervention consisted of an 8 week stress management group program (mind-body medical stress reduction - MBMSR). Follow-up measures were taken after 6 months. RESULTS: Virtually, no drop-out occurred. Our study showed significant effects in the intervention group concerning SF-12 Mental Component Scale (p = 0.05), SF-12 Physical Component Scale (p = 0.001), VAS (in general, p = 0.001) and SWS (emotional reactions, p <0.001), underlined by qualitative results, which showed a higher quality of life. CONCLUSIONS: The effectiveness of an MBMSR program in a group of supposedly healthy students could be demonstrated. Findings suggest that stress management might be given importance at universities that care for the performance, the quality of life, and stress-health status of their students, acknowledging and accounting for the challenging circumstances of university life, as well as the specific needs of the modern student population.

[The importance of mindfulness-based interventions in medical and psychotherapeutic care]. / Die Bedeutung achtsamkeitsbasierter Interventionen in der medizinischen und psychotherapeutischen Versorgung.

BACKGROUND: Mindfulness-based approaches are gaining increasing importance in medicine and psychology. Mindfulness has been described as the intentional and non-judgemental regulation of attention on inner and outer experiences in the present moment. It has been claimed to be conducive to health. METHODS: Based on an electronic literature review, the concept of mindfulness and related approaches in medicine and behavioral psychology are described. This article provides an overview of the status of current research, including randomized trials up to September 2008. The current status of research is summarized regarding effectiveness and underlying mechanisms of mindfulness-based approaches. RESULTS AND CONCLUSION: In spite of methodical flaws of the studies reviewed, numerous findings suggest that mindfulness-based approaches are beneficial in the treatment and prevention of various diseases. In order to further assess specific effects and underlying mechanisms of mindfulness, additional randomized trials have to be conducted which include adequate control interventions.

Do distances among host patches and host density affect the distribution of a specialist parasitoid?

The effect of spatial habitat structure and patchiness may differ among species within a multi-trophic system. Theoretical models predict that species at higher trophic levels are more negatively affected by fragmentation than are their hosts or preys. The absence or presence of the higher trophic level, in turn, can affect the population dynamics of lower levels and even the stability of the trophic system as a whole. The present study examines different effects of spatial habitat structure with two field experiments, using as model system the parasitoid Cotesia popularis which is a specialist larval parasitoid of the herbivore Tyria jacobaeae. One experiment examines the colonisation rate of the parasitoid and the percentage parasitism at distances occurring on a natural scale; the other experiment examines the dispersal rate and the percentage parasitism in relation to the density of the herbivore and its host plant. C. popularis was able to reach artificial host populations at distances up to the largest distance created (at least 80 m from the nearest source population). Also, the percentage parasitism did not differ among the distances. The density experiment showed that the total number of herbivores parasitised was higher in patches with a high density of hosts, regardless of the density of the host plant. The percentage parasitism, however, was not related to the density of the host. The density of the host plant did have a (marginally) significant effect on the percentage parasitism, probably indicating that the parasitoid uses the host plant of the herbivore as a cue to find the herbivore itself. In conclusion, the parasitoid was not affected by the spatial habitat structure on spatial scales that are typical of local patches.