Counter-propagating radiative shock experiments on the Orion laser and the formation of radiative precursors

We present results from new experiments to study the dynamics of radiative shocks, reverse shocks and radiative precursors. Laser ablation of a solid piston by the Orion high-power laser at AWE Aldermaston UK was used to drive radiative shocks into a gas cell initially pressurised between $0.1$ and $1.0 \ bar with different noble gases. Shocks propagated at {80 \pm 10 \ km/s} and experienced strong radiative cooling resulting in post-shock compressions of { \times 25 \pm 2}. A combination of X-ray backlighting, optical self-emission streak imaging and interferometry (multi-frame and streak imaging) were used to simultaneously study both the shock front and the radiative precursor. These experiments present a new configuration to produce counter-propagating radiative shocks, allowing for the study of reverse shocks and providing a unique platform for numerical validation. In addition, the radiative shocks were able to expand freely into a large gas volume without being confined by the walls of the gas cell. This allows for 3-D effects of the shocks to be studied which, in principle, could lead to a more direct comparison to astrophysical phenomena. By maintaining a constant mass density between different gas fills the shocks evolved with similar hydrodynamics but the radiative precursor was found to extend significantly further in higher atomic number gases (\sim$$4$ times further in xenon than neon). Finally, 1-D and 2-D radiative-hydrodynamic simulations are presented showing good agreement with the experimental data.Comment: HEDLA 2016 conference proceeding

Marginalization of end-use technologies in energy innovation for climate protection

Mitigating climate change requires directed innovation efforts to develop and deploy energy technologies. Innovation activities are directed towards the outcome of climate protection by public institutions, policies and resources that in turn shape market behaviour. We analyse diverse indicators of activity throughout the innovation system to assess these efforts. We find efficient end-use technologies contribute large potential emission reductions and provide higher social returns on investment than energy-supply technologies. Yet public institutions, policies and financial resources pervasively privilege energy-supply technologies. Directed innovation efforts are strikingly misaligned with the needs of an emissions-constrained world. Significantly greater effort is needed to develop the full potential of efficient end-use technologies

The Influence of Scale Preferences on the Design of a Water Innovation: A Case in Dutch River Management

The debate on scale use in river management focuses primarily on the (lack of) fit between the bio-geophysical and institutional systems. However, in this article we focus on the ‘subjective’ aspect of scale preferences in water governance. We apply an adapted version of the Integrated Scale Hierarchy for Rivers to determine the degree of fit between the scale preferences of the actors involved in a Dutch case study and the scale requirements of the innovative river management concept. This allows us to understand which riverine processes and characteristics are regarded as important by the different actors and to identify mismatches in scale perspectives as they manifest themselves in water management practice. We discover that inflexibility in scale use on the part of the involved actors places bounds on the design and quality of interventions and demonstrate that a more flexible use of scales in the design phase of a river management intervention has the potential to lead to more effective solutions

Efficacy and Safety of Daprodustat for Treatment of Anemia of Chronic Kidney Disease in Incident Dialysis Patients: A Randomized Clinical Trial

Importance: Daprodustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, is being evaluated as an oral alternative to conventional erythropoiesis-stimulating agent (ESA) therapy. Few studies of anemia treatment in an incident dialysis (ID) population have been reported. Objective: To evaluate the efficacy and safety of daprodustat vs darbepoetin alfa in treating anemia of chronic kidney disease in ID patients. Design, Setting, and Participants: This prospective, randomized, open-label clinical trial was conducted from May 11, 2017, through September 24, 2020, in 90 centers across 14 countries. Patients with advanced CKD were eligible if they planned to start dialysis within 6 weeks from screening or had started and received hemodialysis (HD) or peritoneal dialysis (PD) within 90 days before randomization, had a screening hemoglobin (Hb) concentration of 8.0 to 10.5 g/dL (to convert to grams per liter, multiply by 10) and a randomization Hb of 8.0 to 11.0 g/dL, were ESA-naive or had received limited ESA treatment, and were iron-replete. Interventions: Randomized 1:1 to daprodustat or darbepoetin alfa. Main Outcomes and Measures: The primary analysis in the intent-to-treat population evaluated the mean change in Hb concentration from baseline to evaluation period (weeks 28-52) to assess noninferiority of daprodustat vs darbepoetin alfa (noninferiority margin, −0.75 g/dL). The mean monthly intravenous (IV) iron dose from baseline to week 52 was the principal secondary end point. Rates of treatment-emergent and serious adverse events (AEs) were also compared between treatment groups to assess safety and tolerability. Results: A total of 312 patients (median [IQR] age, 55 [45-65] years; 194 [62%] male) were randomized to either daprodustat (157 patients; median [IQR] age, 52.0 [45-63] years; 96 [61%] male) or darbepoetin alfa (155 patients; median [IQR] age, 56.0 [45-67] years; 98 [63%] male); 306 patients (98%) completed the trial. The mean (SD) Hb concentration during the evaluation period was 10.5 (1.0) g/dL for the daprodustat and 10.6 (0.9) g/dL for the darbepoetin alfa group, with an adjusted mean treatment difference of −0.10 g/dL (95% CI, −0.34 to 0.14 g/dL), indicating noninferiority. There was a reduction in mean monthly IV iron use from baseline to week 52 in both treatment groups; however, daprodustat was not superior compared with darbepoetin alfa in reducing monthly IV iron use (adjusted mean treatment difference, 19.4 mg [95% CI, –11.0 to 49.9 mg]). Adverse event rates were 76% for daprodustat vs 72% for darbepoetin alfa. Conclusions and Relevance: This randomized clinical trial found that daprodustat was noninferior to darbepoetin alfa in treating anemia of CKD and may represent a potential oral alternative to a conventional ESA in the ID population. Trial Registration: ClinicalTrials.gov Identifier: NCT03029208</p

Efficacy and Safety of Daprodustat for Treatment of Anemia of Chronic Kidney Disease in Incident Dialysis Patients A Randomized Clinical Trial

Importance: Daprodustat, a hypoxia-inducible factor prolyl hydroxylase inhibitor, is being evaluated as an oral alternative to conventional erythropoiesis-stimulating agent (ESA) therapy. Few studies of anemia treatment in an incident dialysis (ID) population have been reported. Objective: To evaluate the efficacy and safety of daprodustat vs darbepoetin alfa in treating anemia of chronic kidney disease in ID patients. Design, Setting, and Participants: This prospective, randomized, open-label clinical trial was conducted from May 11, 2017, through September 24, 2020, in 90 centers across 14 countries. Patients with advanced CKD were eligible if they planned to start dialysis within 6 weeks from screening or had started and received hemodialysis (HD) or peritoneal dialysis (PD) within 90 days before randomization, had a screening hemoglobin (Hb) concentration of 8.0 to 10.5 g/dL (to convert to grams per liter, multiply by 10) and a randomization Hb of 8.0 to 11.0 g/dL, were ESA-naive or had received limited ESA treatment, and were iron-replete. Interventions: Randomized 1:1 to daprodustat or darbepoetin alfa. Main Outcomes and Measures: The primary analysis in the intent-to-treat population evaluated the mean change in Hb concentration from baseline to evaluation period (weeks 28-52) to assess noninferiority of daprodustat vs darbepoetin alfa (noninferiority margin, -0.75 g/dL). The mean monthly intravenous (IV) iron dose from baseline to week 52 was the principal secondary end point. Rates of treatment-emergent and serious adverse events (AEs) were also compared between treatment groups to assess safety and tolerability. Results: A total of 312 patients (median [IQR] age, 55 [45-65] years; 194 [62%] male) were randomized to either daprodustat (157 patients; median [IQR] age, 52.0 [45-63] years; 96 [61%] male) or darbepoetin alfa (155 patients; median [IQR] age, 56.0 [45-67] years; 98 [63%] male); 306 patients (98%) completed the trial. The mean (SD) Hb concentration during the evaluation period was 10.5 (1.0) g/dL for the daprodustat and 10.6 (0.9) g/dL for the darbepoetin alfa group, with an adjusted mean treatment difference of -0.10 g/dL (95% CI, -0.34 to 0.14 g/dL), indicating noninferiority. There was a reduction in mean monthly IV iron use from baseline to week 52 in both treatment groups; however, daprodustat was not superior compared with darbepoetin alfa in reducing monthly IV iron use (adjusted mean treatment difference, 19.4 mg [95% CI, -11.0 to 49.9 mg]). Adverse event rates were 76% for daprodustat vs 72% for darbepoetin alfa. Conclusions and Relevance: This randomized clinical trial found that daprodustat was noninferior to darbepoetin alfa in treating anemia of CKD and may represent a potential oral alternative to a conventional ESA in the ID population. Trial Registration: ClinicalTrials.gov Identifier: NCT03029208

Comparing nuclear power trajectories in Germany and the UK: from ‘regimes' to ‘democracies’ in sociotechnical transitions and Discontinuities

This paper focuses on arguably the single most striking contrast in contemporary major energy politics in Europe (and even the developed world as a whole): the starkly differing civil nuclear policies of Germany and the UK. Germany is seeking entirely to phase out nuclear power by 2022. Yet the UK advocates a ‘nuclear renaissance’, promoting the most ambitious new nuclear construction programme in Western Europe.Here,this paper poses a simple yet quite fundamental question: what are the particular divergent conditions most strongly implicated in the contrasting developments in these two countries. With nuclear playing such an iconic role in historical discussions over technological continuity and transformation, answering this may assist in wider understandings of sociotechnical incumbency and discontinuity in the burgeoning field of‘sustainability transitions’. To this end, an ‘abductive’ approach is taken: deploying nine potentially relevant criteria for understanding the different directions pursued in Germany and the UK. Together constituted by 30 parameters spanning literatures related to socio-technical regimes in general as well as nuclear technology in particular, the criteria are divided into those that are ‘internal’ and ‘external’ to the ‘focal regime configuration’ of nuclear power and associated ‘challenger technologies’ like renewables. It is ‘internal’ criteria that are emphasised in conventional sociotechnical regime theory, with ‘external’ criteria relatively less well explored. Asking under each criterion whether attempted discontinuation of nuclear power would be more likely in Germany or the UK, a clear picture emerges. ‘Internal’ criteria suggest attempted nuclear discontinuation should be more likely in the UK than in Germany– the reverse of what is occurring. ‘External’ criteria are more aligned with observed dynamics –especially those relating to military nuclear commitments and broader ‘qualities of democracy’. Despite many differences of framing concerning exactly what constitutes ‘democracy’, a rich political science literature on this point is unanimous in characterising Germany more positively than the UK. Although based only on a single case,a potentially important question is nonetheless raised as to whether sociotechnical regime theory might usefully give greater attention to the general importance of various aspects of democracy in constituting conditions for significant technological discontinuities and transformations. If so, the policy implications are significant. A number of important areas are identified for future research, including the roles of diverse understandings and specific aspects of democracy and the particular relevance of military nuclear commitments– whose under-discussion in civil nuclear policy literatures raises its own questions of democratic accountability

Re-thinking the Fiscal and Monetary Political Economy of the Green State

Proponents of the Green State repudiate the historical antipathy to the state from many in the green movement and endorse the pragmatic usage of state capacity and legitimacy to realise environmental protection. This article offers a sympathetic critique of the Green State’s fiscal and monetary institutional design in order to refine the concept further. It will investigate an under-theorised contradiction in the political economy of the Green State; centring upon the operationalisation of an interventionist state, moving beyond economic growth, and deference to the ceteris paribus conventions of state financing. It is argued that the three cannot co-exist harmoniously, given the ramifications of moving beyond growth for the fiscal capacity of the state. Therefore, there is a need to go further than even Eckersley does in re-politicising and challenging capitalist conventions. Specifically, Eckersley’s own critical constructivist approach is invoked to interrogate the capitalist conventions that constitute the constraints surrounding state financing, such as the depoliticised production of money and the viability of debt relations

Interpretative and predictive modelling of Joint European Torus collisionality scans

Transport modelling of Joint European Torus (JET) dimensionless collisionality scaling experiments in various operational scenarios is presented. Interpretative simulations at a fixed radial position are combined with predictive JETTO simulations of temperatures and densities, using the TGLF transport model. The model includes electromagnetic effects and collisions as well as □(→┬E ) X □(→┬B ) shear in Miller geometry. Focus is on particle transport and the role of the neutral beam injection (NBI) particle source for the density peaking. The experimental 3-point collisionality scans include L-mode, and H-mode (D and H and higher beta D plasma) plasmas in a total of 12 discharges. Experimental results presented in (Tala et al 2017 44th EPS Conf.) indicate that for the H-mode scans, the NBI particle source plays an important role for the density peaking, whereas for the L-mode scan, the influence of the particle source is small. In general, both the interpretative and predictive transport simulations support the experimental conclusions on the role of the NBI particle source for the 12 JET discharges