Volatile diterpene emission by two Mediterranean Cistaceae shrubs

Mediterranean vegetation emits a wide range of biogenic volatile organic compounds (BVOCs) among which isoprenoids present quantitatively the most important compound class. Here, we investigated the isoprenoid emission from two Mediterranean Cistaceae shrubs, Halimium halimifolium and Cistus ladanifer, under controlled and natural conditions, respectively. For the first time, diurnal emission patterns of the diterpene kaurene were detected in real-time by Proton-Transfer-Reaction-Timeof- Flight-Mass-Spectrometer. Kaurene emissions were strongly variable among H. halimifolium plants, ranging from 0.01 ± 0.003 to 0.06 ± 0.01 nmol m−2 s−1 in low and high emitting individuals, respectively. They were in the same order of magnitude as monoterpene (0.01 ± 0.01 to 0.11 ± 0.04 nmol m−2 s−1) and sesquiterpene (0.01 ± 0.01 to 0.52 nmol m−2 s−1) emission rates. Comparable range and variability was found for C. ladanifer under natural conditions. Labelling with 13C-pyruvate suggested that emitted kaurene was not derived from de novo biosynthesis. The high kaurene content in leaves, the weak relationship with ecophysiological parameters and the tendency of higher emissions with increasing temperatures in the field indicate an emission from storage pools. This study highlights significant emissions of kaurene from two Mediterranean shrub species, indicating that the release of diterpenes into the atmosphere should probably deserve more attention in the futureinfo:eu-repo/semantics/publishedVersio

Parent-child value similarity and subjective well-being in the context of migration: An exploration

Intergenerational value similarity has a different meaning for migrants and minorities compared to the majority society. Whereas high parent-child value similarity among majority families more likely indicates successful internalization of societal values, high intergenerational similarity among migrants may indicate a lack of social integration into the host society. The present paper links parent-adolescent value similarity among migrant/minority and majority families to subjective well-being in two societies, Germany and Israel (Total N = 977 families). Analyses assess intergenerational similarity on all values from the Schwartz value circumplex. Among majority groups intergenerational value similarity is a predictor of life satisfaction. In minority groups it is more so a low distance of a family’s value preferences to the modal values of the majority group that predicts life satisfaction – but only in Israel

First eddy covariance flux measurements by PTR-TOF

The recently developed PTR-TOF instrument was evaluated to measure methanol fluxes emitted from grass land using the eddy covariance method. The high time resolution of the PTR-TOF allowed storing full mass spectra up to <i>m/z</i> 315 with a frequency of 10 Hz. Three isobaric ions were found at a nominal mass of <i>m/z</i> 33 due to the high mass resolving power of the PTR-TOF. Only one of the three peaks contributed to eddy covariance fluxes. The exact mass of this peak agrees well with the exact mass of protonated methanol (<i>m/z</i> 33.0335). The eddy covariance methanol fluxes measured with PTR-TOF were compared to virtual disjunct eddy covariance methanol fluxes simultaneously measured with a conventional PTR-MS. The methanol fluxes from both instruments show excellent agreement

Friendships Fighting Prejudice: A Longitudinal Perspective on Adolescents’ Cross-Group Friendships with Immigrants

Increasingly, adolescents are growing up in multiethnic multicultural societies. While intergroup prejudice can threaten the multicultural societal cohesion, intergroup friendships are strong predictors of reduced prejudice. Thus, more research is needed to fully understand the development of intergroup friendships and their relations to less prejudicial attitudes. This study addressed two major developmental research questions: first, whether longitudinal patterns of intergroup friendships of native adolescents (i.e., whether or not a native German adolescent has a friendship with an immigrant at different points in time) relate to changes in rates of prejudice about immigrants. Second, whether these friendship patterns that unfold over time can be predicted by contact opportunities, attitudes, subjective norms, and perceived behavioral control assessed at the beginning of the study. The sample included 372 native German adolescents (14.7 years of age at first assessment, 62.3 % girls) who showed one of four friendship trajectories over the three annual assessments: they either maintained, gained, never had, or lost a friendship with an outgroup peer. In particular, results showed that adolescents who gained an intergroup friendship over the three time points showed a significant decrease in negative prejudice over the study. All four theorized predictors contributed to explain friendship trajectory membership. Generally, adolescents with many opportunities for contact, positive attitudes about contact, perceived positive social norms for contact, and high levels of behavioral control (self-efficacy) were more likely to maintain a friendship with an outgroup member than to follow any of the three other friendship trajectories (gain, lost, or never had). The pattern of predictions differed, however, depending on the specific pairs of friendship trajectories compared

Two sides of a story: Mothers' and adolescents' agreement on child disclosure in immigrant and native families

Research on immigrant families often has suggested that the process of immigration can lead to a distancing of adolescents and their parents. This study examined the actual agreement of immigrant and native mother–adolescent dyads in their reports on children’s disclosure as an indicator for a trusting mother–child relationship. The research questions related to group-level differences (immigrant vs. native dyads) in mother–adolescent agreement, the prediction of interdyadic differences in mother–adolescent agreement, and the associations between mother–adolescent agreement and both family conflicts and adolescents’ depressive symptoms. The sample was comprised of mother–adolescent dyads: 197 native German dyads (adolescents: mean age 14.7 years, 53 % female) and 185 immigrant dyads from the former Soviet Union (adolescents: mean age 15.7 years, 60 % female). Agreement was assessed using the intraclass correlation coefficient. The results revealed that mother–adolescent agreement was lower in immigrant dyads than in native dyads. In both samples, higher levels of adolescent autonomy predicted lower mother–adolescent agreement. Among immigrants, language brokering was an additional predictor of lower levels of mother–adolescent agreement. The interaction of language brokering and autonomy also turned out to be significant, indicating that if an adolescent was high in language brokering or autonomy, the effect of the other variable was negligible. In both groups, mother–adolescent agreement was negatively related to family conflicts. The study shows that processes in immigrant and native families are rather similar, but that in immigrant families some additional acculturation-related factors have to be considered for a full understanding of family dynamics