"Bed bugs live in dirty places"-How Using Live Animals in Teaching Contributes to Reducing Stigma, Disgust, Psychological Stigma, and Misinformation in Students.

Bed bugs are on the rise and are increasingly perceived as harmful parasites. Because individuals affected by bed bugs often feel disgust and shame and are stigmatized, bed bugs are an important public health and environmental justice concern and therefore a health education issue as well. In this quasi-experimental study, we examine how different constructs, namely, forms of stigma, disgust, psychological distance, and myths about bed bugs (dependent variables), change over time (pre/posttest) in response to two forms of teaching intervention (independent variables) in upper secondary-level high school. The content of the interventions was the same, but in class, we showed live bed bugs to one group of students, assuming this would lead to a more realistic, less imaginative response to bed bugs than in the group presented with only pictures of bed bugs. Together with previous studies, we assumed that live bed bugs would be perceived as less disgusting and with a lower degree of stigmatization. Our results show that stigma, psychological distance, and myths can be reduced through intervention (regardless of live animal or picture). Disgust was more strongly reduced by live animals than by pictures. We present implications for biology education and contemporary health education.

German high school students' attitudes and interest in cancer and factors influencing proactive behaviour for cancer prevention.

Cancer diseases are pertinent topics to young people, who are confronted with the issue through media or family members that suffer from these diseases. Based on a paper-and-pencil questionnaire, we investigated German high school students' (N = 369, 16-18 years old) interest in and their attitudes towards cancer. Attitude was assessed measuring multiple dimensions that included scales to measure several components: the cognitive (beliefs about the controllability of cancer), the affective (emotional responses towards cancer) and the behavioural (intention for proactive behaviour towards cancer) components. A student assessment of carcinogenic risk factor was executed. Our results suggest that students' willingness to deal with the topic cancer (e.g. to communicate about cancer or to reconsider their lifestyle) is highly dependent on their interest, their emotional responses and their beliefs about the controllability of cancer. Their assessment of carcinogenic risk factors does not have a direct influence on their intentions to behave proactively against cancer but might have an indirect influence on their beliefs about the controllability of cancer. Based on these results, we have drawn teaching implications and discussed which factors should be included in teaching processes in order to stimulate proactive behaviour related to cancer prevention.

Carbon flux and growth in mature deciduous forest trees exposed to elevated CO2.

Whether rising atmospheric carbon dioxide (CO2) concentrations will cause forests to grow faster and store more carbon is an open question. Using free air CO2 release in combination with a canopy crane, we found an immediate and sustained enhancement of carbon flux through 35-meter-tall temperate forest trees when exposed to elevated CO2. However, there was no overall stimulation in stem growth and leaf litter production after 4 years. Photosynthetic capacity was not reduced, leaf chemistry changes were minor, and tree species differed in their responses. Although growing vigorously, these trees did not accrete more biomass carbon in stems in response to elevated CO2, thus challenging projections of growth responses derived from tests with smaller trees.

Responses of deciduous forest trees to severe drought in Central Europe.

In 2003, Central Europe experienced the warmest summer on record combined with unusually low precipitation. We studied plant water relations and phenology in a 100-year- old mixed deciduous forest on a slope (no ground water table) near Basel using the Swiss Canopy Crane (SCC). The drought lasted from early June to mid September. We studied five deciduous tree species; half of the individuals were exposed to elevated CO(2) concentration ([CO(2)]) (530 ppm) using a free-air, atmospheric CO(2)-enrichment system. In late July, after the first eight weeks of drought, mean predawn leaf water potential about 30 m above ground was -0.9 MPa across all trees, dropping to a mean of -1.5 MPa in mid-August when the top 1 m of the soil profile had no plant accessible moisture. Mean stomatal conductance and rates of maximum net photosynthesis decreased considerably in mid-August across all species. However, daily peak values of sap flow remained surprisingly constant over the whole period in Quercus petraea (Matt.) Liebl., and decreased to only about half of the early summer maxima in Fagus sylvatica L. and Carpinus betulus L. (stomatal down- regulation of flux). Although we detected no differences in most parameters between CO(2)-treated and control trees, predawn leaf water potential tended to be less negative in trees exposed to elevated [CO(2)]. Leaf longevity was greater in 2003 compared with the previous years, but the seasonal increase in stem basal area reached only about 75% of that in previous years. Our data suggest that the investigated tree species, particularly Q. petraea, did not experience severe water stress. However, an increased frequency of such exceptionally dry summers may have a more serious impact than a single event and would give Q. petraea a competitive advantage in the long run.

Growth and reproduction of the alpine grasshopper Miramella alpina feeding on CO2-enriched dwarf shrubs at treeline.

The consequences for plant-insect interactions of atmospheric changes in alpine ecosystems are not well understood. Here, we tested the effects of elevated CO(2) on leaf quality in two dwarf shrub species (Vaccinium myrtillus and V. uliginosum) and the response of the alpine grasshopper (Miramella alpina) feeding on these plants in a field experiment at the alpine treeline (2,180 m a.s.l.) in Davos, Switzerland. Relative growth rates (RGR) of M. alpina nymphs were lower when they were feeding on V. myrtillus compared to V. uliginosum, and were affected by elevated CO(2) depending on plant species and nymph developmental stage. Changes in RGR correlated with CO(2)-induced changes in leaf water, nitrogen, and starch concentrations. Elevated CO(2) resulted in reduced female adult weight irrespective of plant species, and prolonged development time on V. uliginosum only, but there were no significant differences in nymphal mortality. Newly molted adults of M. alpina produced lighter eggs and less secretion (serving as egg protection) under elevated CO(2). When grasshoppers had a choice among four different plant species grown either under ambient or elevated CO(2), V. myrtillus and V. uliginosum consumption increased under elevated CO(2) in females while it decreased in males compared to ambient CO(2)-grown leaves. Our findings suggest that rising atmospheric CO(2) distinctly affects leaf chemistry in two important dwarf shrub species at the alpine treeline, leading to changes in feeding behavior, growth, and reproduction of the most important insect herbivore in this system. Changes in plant-grasshopper interactions might have significant long-term impacts on herbivore pressure, community dynamics and ecosystem stability in the alpine treeline ecotone.

Atmospheric CO2 enrichment of alpine treeline conifers.

• Experimental CO2 enrichment of mature Larix decidua and Pinus uncinata trees and their understory vegetation was used to test the carbon limitation hypothesis of treeline formation at the alpine treeline in Switzerland. • Forty plots (each 1.1 m2 ) were established; half of them were exposed to elevated (566 ppm) atmospheric CO2 using a free air CO2 enrichment (FACE) system releasing pure CO2 , and the other half were treated as controls at current ambient [CO2 ]. • Reliable and adequate CO2 control was achieved, with 63% and 90% of 1-min averages having a [CO2 ] within ±10% and ±20% of the target value, respectively, which is comparable to previous FACE systems. Both tree species showed higher net photosynthesis, lower stomatal conductance, and increased accumulation of nonstructural carbohydrates in response to CO2 in the first year of treatment. Quite unexpectedly, shoot length increment increased significantly at elevated CO2 (up to 23%) compared with controls in both species. • The pure CO2 release technology proved suitable for CO2 enrichment of native trees on this remote mountain slope. Our results suggest an improved C balance and growth of treeline trees in response to elevated CO2 . However, it is unclear whether this initial growth stimulation will persist in the longer term.