Not stupid, but lazy? Psychological benefits of disruptive classroom behavior from an attributional perspective

Disruptive student behavior is a frequent part of school life, most often shown by male students and related to many negative academic outcomes. In this study, we examined the psychological benefits of engaging in disruptive behavior for low-achieving students from an attributional perspective. In an experimental vignette study of 178 ninth graders from Germany, we tested whether the students’ ratings of a target student who displayed disruptive behavior (instead of unobtrusive behavior) in a vignette would evoke lack-of-effort attributions for academic failure through students’ expectations of teachers’ reprimands. In order to account for the nested data structure (vignettes nested in participants), we applied multilevel analysis while testing for mediation effects. Results showed that the disruptive behavior of a target student triggered lack-of-effort attributions in students instead of lack-of-ability attributions for low academic achievement. This effect was mediated by students’ expectations of teachers’ reprimands. In addition, low-achieving students showing disruptive behavior were perceived as more popular but less liked personally and as more masculine and less feminine. The study adds to the understanding of disruptive behavior in class as an attempt of poor-performing students to elicit face-saving attributions for academic failure and enhance their peer status

Risk of severe climate change impact on the terrestrial biosphere

The functioning of many ecosystems and their associated resilience could become severely compromised by climate change over the 21st century. We present a global risk analysis of terrestrial ecosystem changes based on an aggregate metric of joint changes in macroscopic ecosystem features including vegetation structure as well as carbon and water fluxes and stores. We apply this metric to global ecosystem simulations with a dynamic global vegetation model (LPJmL) under 58 WCRP CMIP3 climate change projections. Given the current knowledge of ecosystem processes and projected climate change patterns, we find that severe ecosystem changes cannot be excluded on any continent. They are likely to occur (in > 90% of the climate projections) in the boreal–temperate ecotone where heat and drought stress might lead to large-scale forest die-back, along boreal and mountainous tree lines where the temperature limitation will be alleviated, and in water-limited ecosystems where elevated atmospheric CO2 concentration will lead to increased water use efficiency of photosynthesis. Considerable ecosystem changes can be expected above 3 K local temperature change in cold and tropical climates and above 4 K in the temperate zone. Sensitivity to temperature change increases with decreasing precipitation in tropical and temperate ecosystems. In summary, there is a risk of substantial restructuring of the global land biosphere on current trajectories of climate change.Peer Reviewe

Do Teachers' Beliefs About Math Aptitude and Brilliance Explain Gender Differences in Children's Math Ability Self-Concept?

The self-concept of ability in math in elementary school is an early predictor for future math-related choices and careers. Unfortunately, already at this early age girls report lower ability self-concepts in math than boys—despite their comparable performances in objective math competence tests. In the present study we focus on teachers' beliefs as factors explaining these gender differences. Women's underrepresentation in math and science in academia has recently been explained by the belief held by the environment that success in these domains requires an innate ability that cannot be taught (“brilliance”). In addition, teachers' beliefs regarding their students' mathematical aptitude have also been found to influence students' self-concepts of ability. Here, we study if teachers' beliefs regarding their students' mathematical aptitude and brilliance beliefs may account for gender differences in elementary school students' self-concept of ability in math and thus potentially contribute to entering the gendered path into math and science professions. In a sample of 830 fourth graders (M = 9.14 years old, 49% female) and 56 elementary school teachers from Germany, we assessed teachers' beliefs regarding their students' mathematical aptitude and their belief that children need brilliance to succeed in math as well as children's mathematical ability self-concept and competencies. In line with prior research, boys reported a statistically significantly more positive math ability self-concept (d = 0.50), although boys and girls reached similar scores in a standardized math competence test (d = 0.07). However, multilevel regression analyses revealed that teachers' math brilliance beliefs were not related to the gender gap in students' ability self-concept in expense of girls whereas the gender gap was mediated by teachers' beliefs about their students' mathematical aptitude. These findings suggest that math brilliance beliefs held by important socializers such as teachers might not play a role in explaining gender differences in math-related motivation in elementary school whereas teachers' beliefs about students' math aptitude do. Results are discussed against the background of teacher expectancy effects, developmental changes in elementary school, and cultural differences

Contribution of permafrost soils to the global carbon budget

Climate warming affects permafrost soil carbon pools in two opposing ways: enhanced vegetation growth leads to higher carbon inputs to the soil, whereas permafrost melting accelerates decomposition and hence carbon release. Here, we study the spatial and temporal dynamics of these two processes under scenarios of climate change and evaluate their influence on the carbon balance of the permafrost zone. We use the dynamic global vegetation model LPJmL, which simulates plant physiological and ecological processes and includes a newly developed discrete layer energy balance permafrost module and a vertical carbon distribution within the soil layer. The model is able to reproduce the interactions between vegetation and soil carbon dynamics as well as to simulate dynamic permafrost changes resulting from changes in the climate. We find that vegetation responds more rapidly to warming of the permafrost zone than soil carbon pools due to long time lags in permafrost thawing, and that the initial simulated net uptake of carbon may continue for some decades of warming. However, once the turning point is reached, if carbon release exceeds uptake, carbon is lost irreversibly from the system and cannot be compensated for by increasing vegetation carbon input. Our analysis highlights the importance of including dynamic vegetation and long-term responses into analyses of permafrost zone carbon budgets

Terrestrial vegetation redistribution and carbon balance under climate change

BACKGROUND: Dynamic Global Vegetation Models (DGVMs) compute the terrestrial carbon balance as well as the transient spatial distribution of vegetation. We study two scenarios of moderate and strong climate change (2.9 K and 5.3 K temperature increase over present) to investigate the spatial redistribution of major vegetation types and their carbon balance in the year 2100. RESULTS: The world's land vegetation will be more deciduous than at present, and contain about 125 billion tons of additional carbon. While a recession of the boreal forest is simulated in some areas, along with a general expansion to the north, we do not observe a reported collapse of the central Amazonian rain forest. Rather, a decrease of biomass and a change of vegetation type occurs in its northeastern part. The ability of the terrestrial biosphere to sequester carbon from the atmosphere declines strongly in the second half of the 21(st )century. CONCLUSION: Climate change will cause widespread shifts in the distribution of major vegetation functional types on all continents by the year 2100

Breakdown of the Endothelial Barrier Function in Tumor Cell Transmigration

The ability of tumor cells to metastasize is associated with a poor prognosis for cancer. During the process of metastasis, tumor cells circulating in the blood or lymph vessels can adhere to, and potentially transmigrate through, the endothelium and invade the connective tissue. We studied the effectiveness of the endothelium as a barrier against the invasion of 51 tumor cell lines into a three-dimensional collagen matrix. Only nine tumor cell lines showed attenuated invasion in the presence of an endothelial cell monolayer, whereas 17 cell lines became invasive or showed a significantly increased invasion. Endothelial cells cocultured with invasive tumor cells increased chemokine gene expression of IL-8 and Gro-β. Expression of the IL-8 and Gro-β receptor, CXCR2, was upregulated in invasive tumor cells. Addition of IL-8 or Gro-β increased tumor cell invasiveness by more than twofold. Tumor cell variants selected for high CXCR2 expression were fourfold more invasive in the presence of an endothelial cell layer, whereas CXCR2 siRNA knock-down cells were fivefold less invasive. We demonstrate that Gro-β and IL-8 secreted by endothelial cells, together with CXCR2 receptor expression on invasive tumor cells, contribute to the breakdown of the endothelial barrier by enhancing tumor cell force generation and cytoskeletal remodeling dynamics

Modeling the Sensitivity of the Seasonal Cycle of GPP to Dynamic LAI and Soil Depths in Tropical Rainforests

International audienc

Do teachers' beliefs about math aptitude and brilliance explain gender differences in children's math ability self-concept?

The self-concept of ability in math in elementary school is an early predictor for future math-related choices and careers. Unfortunately, already at this early age girls report lower ability self-concepts in math than boys—despite their comparable performances in objective math competence tests. In the present study we focus on teachers' beliefs as factors explaining these gender differences. Women's underrepresentation in math and science in academia has recently been explained by the belief held by the environment that success in these domains requires an innate ability that cannot be taught (“brilliance”). In addition, teachers' beliefs regarding their students' mathematical aptitude have also been found to influence students' self-concepts of ability. Here, we study if teachers' beliefs regarding their students' mathematical aptitude and brilliance beliefs may account for gender differences in elementary school students' self-concept of ability in math and thus potentially contribute to entering the gendered path into math and science professions. In a sample of 830 fourth graders (M = 9.14 years old, 49% female) and 56 elementary school teachers from Germany, we assessed teachers' beliefs regarding their students' mathematical aptitude and their belief that children need brilliance to succeed in math as well as children's mathematical ability self-concept and competencies. In line with prior research, boys reported a statistically significantly more positive math ability self-concept (d = 0.50), although boys and girls reached similar scores in a standardized math competence test (d = 0.07). However, multilevel regression analyses revealed that teachers' math brilliance beliefs were not related to the gender gap in students' ability self-concept in expense of girls whereas the gender gap was mediated by teachers' beliefs about their students' mathematical aptitude. These findings suggest that math brilliance beliefs held by important socializers such as teachers might not play a role in explaining gender differences in math-related motivation in elementary school whereas teachers' beliefs about students' math aptitude do. Results are discussed against the background of teacher expectancy effects, developmental changes in elementary school, and cultural differences

Transnationale Kulturalität - Ein konzeptioneller Vorschlag zum Problem der Sozialintegration transnationaler Konzerne am Beispiel der Automobilindustrie

Mense-Petermann U. Transnationale Kulturalität - Ein konzeptioneller Vorschlag zum Problem der Sozialintegration transnationaler Konzerne am Beispiel der Automobilindustrie. In: Schmidt G, Bungsche H, Heyder T, Klemm M, eds. Und es fährt und fährt .. Automobilindustrie und Automobilkultur am Beginn des 21. Jahrhunderts. Berlin: Sigma; 2005: 173-200