the climate change issue in Germany 2007-2010

This paper assesses the impact of large events such as the financial crisis in 2008 and the Copenhagen meeting in 2009 on the public attention attributed to the climate change issue and to the related policy discourse in the German press. Based on a quantitative content analysis of the two largest German national quality newspapers, a quasi-experimental approach will be adopted, testing the propositions of “punctuated equilibrium theory” (Baumgartner & Jones 1993) in policy analysis. The paper will also use concepts and approaches in the area of discourse analysis – from qualitative methods to more formal quantitative approaches to the analysis of discourse structures and network relations (Janning et al 2009). Large scale and focusing events such as the economic crisis or the Copenhagen meeting can trigger shifts and changes in the discourse on climate change. Preliminary analysis has shown that the economic crisis produced a kink in the issue-attention cycle, triggering a substantial decrease in public attention as public attention to the economic crisis soared. Moreover, the results indicate that actors have changed their discursive behavior in the light of the economic crisis, entailing changes in the actors’ standing and the frames applied by them to the issue of climate change (Vogt 2009). As natural experiments run short of quantifying causal links between variables, the observed changes in public attention and discursive behavior can at least be explained by qualitative explanatory sketches in which the changes and shifts are traced and interrelated by visual descriptions at various levels

Nonlinear distortion of intense THz beams

Near- and far-field beam profiles were measured for THz pulses generated in LiNbO3 by optical rectification of 200 fs pulses with a tilted pulse front. The variation of the THz beam size and a dramatically increasing divergence angle with increasing pump fluence were observed in the (horizontal) plane of the pulse front tilt. No significant variation was observed in the vertical direction. The reason for the observed nonlinear beam distortion is the shortening of the effective interaction length for THz generation caused by the combined effect of pump spectral broadening and angular dispersion in the tilted pulse front geometry. Our results indicate that nonlinear THz beam distortion effects have to be taken into account when designing intense THz sources and related experiments

Velocity Model for CO2 Sequestration in the Southeastern United States Atlantic Continental Margin

The sequestration of carbon dioxide (CO2) is emerging as a major player in offsetting anthropogenic greenhouse gas emissions. With 40% of the United States’ anthropogenic CO2 emissions originating in the southeast, characterizing potential CO2 sequestration sites is vital to reducing the United States’ emissions. The overall goal of this research project, funded by the Department of Energy, is to estimate the CO2 storage potential for the Southeastern United States Atlantic Continental Margin. Previous studies find storage potential in the Atlantic continental margin. Up to 16 Gt and 175 Gt of storage potential are estimated for the Upper Cretaceous and Lower Cretaceous formations, respectively. Considering 5.2 Gt of CO2 were emitted by the United States in 2016, substantial storage potential is present in the Southeastern United States Atlantic Continental Margin. Stratigraphic units were picked in two-way-time depth and were converted to depths in feet. Seismic reflection horizons were extrapolated using well log data from the COST GE-1 well. An interpolated seismic section was created using these seismic horizons. A velocity model was created using previously published stacking velocities. Semblance analysis was used to pick stacking velocities on common midpoint gathers from selected pre-stack seismic lines. These velocity analysis points were used for quality control of the published stacking velocities. Stacking velocities were converted to interval velocities using Dix conversion. These interval velocities are used to create the velocity model and calculate the depths of stratigraphic units in feet. Using this velocity model, the seismic reflection data can be converted to depth in order to estimate the thickness and storage potential of CO2 reservoirs in the Southeastern United States Atlantic Continental Margin

Leptin is required for hypothalamic regulation of miRNAs targeting POMC 3 ′ UTR

International audienceThe central nervous system (CNS) monitors modifications in metabolic parameters or hormone levels and elicits adaptive responses such as food intake regulation. Particularly, within the hypothalamus, leptin modulates the activity of pro-opiomelanocortin (POMC) neurons which are critical regulators of energy balance. Consistent with a pivotal role of the melanocortin system in the control of energy homeostasis, disruption of the POMC gene causes hyperphagia and obesity. MicroRNAs (miRNAs) are short noncoding RNA molecules that post-transcriptionally repress the expression of genes by binding to 3 ′-untranslated regions (3 ′ UTR) of the target mRNAs. However, little is known regarding the role of miRNAs that target POMC 3 ′ UTR in the central control energy homeostasis. Particularly, their interaction with the leptin signaling pathway remain unclear. First, we used common prediction programs to search for potential miRNAs target sites on 3 ′ UTR of POMC mRNA. This screening identified a set of conserved miRNAs seed sequences for mir-383, mir-384-3p, and mir-488. We observed that mir-383, mir-384-3p, and mir-488 are up-regulated in the hypothalamus of leptin deficient ob/ob mice. In accordance with these observations, we also showed that mir-383, mir-384-3p, and mir-488 were increased in db/db mice that exhibit a non-functional leptin receptor. The intraperitoneal injection of leptin down-regulated the expression of these miRNAs of interest in the hypothalamus of ob/ob mice showing the involvement of leptin in the expression of mir-383, mir-384-3p, and mir-488. Finally, the evaluation of responsivity to intracerebroventricular administration of leptin exhibited that a chronic treatment with leptin decreased mir-488 expression in hypothalamus of C57BL/6 mice. In summary, these results suggest that leptin modulates the expression of miRNAs that target POMC mRNA in hypothalamus