Summaries

Summaries

Summaries     

Human responses to social-ecological traps

Social-ecological (SE) traps refer to persistent mismatches between the responses of people, or organisms, and their social and ecological conditions that are undesirable from a sustainability perspective. Until now, the occurrence of SE traps is primarily explained from a lack of adaptive capacity; not much attention is paid to other causal factors. In our article, we address this concern by theorizing the variety of human responses to SE traps and the effect of these responses on trap dynamics. Besides (adaptive) capacities, we theorize desires, abilities and opportunities as important additional drivers to explain the diversity of human responses to traps. Using these theoretical concepts, we construct a typology of human responses to SE traps, and illustrate its empirical relevance with three cases of SE traps: Swedish Baltic Sea fishery; amaXhosa rural livelihoods; and Pamir smallholder farming. We conclude with a discussion of how attention to the diversity in human response to SE traps may inform future academic research and planned interventions to prevent or dissolve SE traps.     

Perinatal dioxin exposure, cytochrome P-450 activity, liver functions and thyroid hormones at follow-up after 7-12 years

OBJECTIVES: Prenatal and lactational exposure to Dutch "background" dioxin levels may cause health effects spanning many years. In addition, perinatal studies have shown a relationship between dioxin exposure and thyroid disturbance. To assess the later health effects of prenatal and lactational dioxin exposure on liver function we measured plasma ALAT and ASAT levels amongst our longitudinal cohort, as was done perinatally and at 2(1/2) years. The children underwent a caffeine loading test to determine CYP1A2 activity. To assess the later effects on thyroid function we measured plasma TSH and FT4. STUDY DESIGN: A longitudinal cohort of 37 healthy children (age 7-12, mean 8.2 years), with documented prenatal and lactational dioxin exposure, ingested 3mg caffeine/kg BW 6h prior to blood withdrawal. Paraxanthine/caffeine molar ratio, ALAT, ASAT, TSH and FT4 were determined in venous blood. RESULTS: Linear regression of ASAT and ALAT revealed no relation with prenatal and lactational dioxin exposure. No correlation was found between the paraxanthine/caffeine molar ratio and prenatal and lactational dioxin exposure. Linear regression of TSH and FT4 revealed no relation with prenatal and lactational dioxin exposure. CONCLUSION: This follow-up has shown a normalisation of previously abnormal ALAT and ASAT levels, indicating a transient effect. CYP1A2 activity, measured by means of a caffeine-loading test, revealed no correlation with the prenatal and lactational exposures. A normalisation of previously abnormal thyroid hormone homeostasis was seen, also possibly indicating a transient effect. This study provides new data on long-term follow-up after perinatal dioxin exposure to background levels of dioxins.     

The varying roles of the dimensions of affluence in air pollution: a regional STIRPAT analysis for Germany

Environmental Science and Pollution Research - STIRPAT models investigate the impacts of population, affluence, and technology on the environment, with most STIRPAT studies revealing positive...     

Challenges and opportunities of power systems from smart homes to super-grids

The world’s power systems are facing a structural change including liberalization of markets and integration of renewable energy sources. This paper describes the challenges that lie ahead in this process and points out avenues for overcoming different problems at different scopes, ranging from individual homes to international super-grids. We apply energy system models at those different scopes and find a trade-off between technical and social complexity. Small-scale systems would require technological breakthroughs, especially for storage, but individual agents can and do already start to build and operate such systems. In contrast, large-scale systems could potentially be more efficient from a techno-economic point of view. However, new political frameworks are required that enable long-term cooperation among sovereign entities through mutual trust. Which scope first achieves its breakthrough is not clear yet.     

Early loss and multiple return of the lower temporal arcade in diapsid reptiles

The temporal arches of diapsid reptiles have received attention for several decades. In particular, it has been observed that the lower temporal bar at the ventral margin of the cheek is frequently reduced due to the absence of a contact between jugal and quadratojugal. The loss of the arcade was formerly considered to be of high systematic value, but is now often interpreted as being autapomorphic for the respective taxon, and the presence of both arcades is generally regarded as a plesiomorphic feature. Here I show, based on a cladistic analysis as well as on further anatomical evidence, that the lower temporal arcade was lost only once in diapsid evolution, and that the presence of the arch in "higher" diapsids is secondary, which is indicated by the different ratio between jugal and quadratojugal as well as by ontogeny. This result also sheds new light on the understanding of the cheek configuration of enigmatic taxa such as ichthyosaurs and turtles.Electronic Supplementary Material  Supplementary material is available for this article if you access the article at . A link in the frame on the left on that page takes you directly to the supplementary material.