352 research outputs found

    The EU debt crisis: Testing and revisiting conventional legal doctrine. LEQS Discussion Paper No. 108/2016 April 2016

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    Controversies surrounding the European sovereign debt crisis loom prominent in the public debate. From a legal perspective, the no-bailout rule and the ban on monetary financing constitute the main principles governing the legality review of financial assistance and liquidity measures. Interpretation of these rules are full of empirical claims. According to conventional legal doctrine, bond spreads only depend on the country’s debt position, largely ignoring other causal factors including liquidity. We test the hypotheses implicit in conventional legal reasoning. We find evidence that a significant part of the surge in the spreads of the peripheral Eurozone countries was disconnected from underlying fundamentals and particularly from a country’s debt position, and was associated rather strongly with market sentiments and liquidity concerns. We apply our empirical findings to the legal principles as interpreted by recent jurisprudence arguing that application of the nobailout principle and the ban on monetary financing should be extended to capture non-debt related factors. Also, the empirical results suggest taking recourse to alternative legal grounds for reviewing the legality of anti-crisis instruments and allowing for a lender of last resort in the euro zone

    Effect of 20 mph traffic speed zones on road injuries in London, 1986-2006: controlled interrupted time series analysis

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    Objective To quantify the effect of the introduction of 20 mph (32 km an hour) traffic speed zones on road collisions, injuries, and fatalities in London

    Modelling the influence of air on the deformation and recrystallisation mechanisms in polar firn and ice

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    Within their upper approximately thousand meters, ice sheets on Earth contain a significant amount of air and air hydrates below. In the permeable firn, this air is still exchanging with the atmosphere and is under atmospheric pressure, whereas the air bubbles are entrapped at the firn-ice transition 60 – 120 m depth. As recent research showed, the presence of air bubbles can significantly influence microdynamical processes such as grain growth and grain boundary migration (Azuma et al., 2012, Roessiger et al., 2014). Understanding the dominant deformation mechanisms has essential implications on paleo-atmosphere research and allows more realistic modelling of ice sheet dynamics. Therefore, numerical models were set up and performed focussing on the implications of the presence of bubbles on recrystallisation and the mechanical properties of ice with air inclusions. The 2D numerical microstructural modelling platform Elle was coupled to the full-field crystal plasticity code of Lebensohn (2001), which is using a Fast Fourier Transform (FFT) following the approach by Griera et al. (2013). Taking into account the mechanical anisotropy of ice, FFT calculates the viscoplastic response of polycrystalline and polyphase materials that deform by dislocation glide, predicts lattice re-orientation and using the local gradient of the strain-rate field, dislocation densities are calculated. FFT was used for the simulation of dynamic recrystallization of pure ice by Montagnat et al. (2013). Polyphase grain boundary migration driven by surface energy and internal strain energy reduction was incorporated in the code and now also enables us to model deformation of ice with air bubbles. The approach is based on the methodology of Becker et al. (2008) and Roessiger et al. (2014). During Deformation, spherical to elliptical bubble shapes are only maintained, when surface energy based recrystallisation is activated, whereas they quickly collapse at low strains in the absence of recrystallisation. The presence of bubbles leads to increased localization of stress, strain and dislocation densities, a reduction of the bulk strength of the bubbly ice is observed. Furthermore, strain-induced grain boundary migration already occuring in the uppermost levels of ice sheets (Kipfstuhl et al. 2009, Weikusat et al. 2009) is confirmed by our modelling. References Azuma, N., Miyakoshi, T., Yokoyama, S., Takata, M., 2012. Journal of Structural Geology 42, 184- 193. Becker, J.K., Bons, P.D., Jessell, M.W., 2008. Computers & Geosciences 34, 201-212. Bons, P.D., Koehn, D., Jessell, M.W. (Eds.), 2008. Microdynamic Simulation. Springer, Berlin. Kipfstuhl, S., Faria, S.H., Azuma, N., Freitag, J., Hamann, I., Kaufmann, P., Miller, H., Weiler, K., Wilhelms, F., 2009. Journal of Geophysical Research 114, B05204. Lebensohn, R.A., 2001. Acta Mater 49 (14), 2723e2737. Montagnat, M., Castelnau, O., Bons, P.D., Faria, S.H., Gagliardini, O., Gillet-Chaulet, F., Grennerat, F., Griera, A., Lebensohn, R.A., Moulinec, H., Roessiger, J., Suquet, P., 2014. Journal of Structural Geology 61, 78-108 Rößiger, J., Bons, P.D., Faria, S.H., 2014. Journal of Structural Geology 61, 123-132 Weikusat, I., Kipfstuhl, S., Faria, S.H., Azuma, N., Miyamoto, A., 2009. Journal of Glaciology 55, 461-472

    The EU debt crisis: testing and revisiting conventional legal doctrine

    Get PDF
    Controversies surrounding the European sovereign debt crisis loom prominent in the public debate. From a legal perspective, the no-bailout rule and the ban on monetary financing constitute the main principles governing the legality review of financial assistance and liquidity measures. Interpretation of these rules are full of empirical claims. According to conventional legal doctrine, bond spreads only depend on the country’s debt position, largely ignoring other causal factors including liquidity. We test the hypotheses implicit in conventional legal reasoning. We find evidence that a significant part of the surge in the spreads of the peripheral Eurozone countries was disconnected from underlying fundamentals and particularly from a country’s debt position, and was associated rather strongly with market sentiments and liquidity concerns. We apply our empirical findings to the legal principles as interpreted by recent jurisprudence arguing that application of the no-bailout principle and the ban on monetary financing should be extended to capture non-debt related factors. Also, the empirical results suggest taking recourse to alternative legal grounds for reviewing the legality of anti-crisis instruments and allowing for a lender of last resort in the euro zone

    Strain localisation and dynamic recrystallisation in the ice-air aggregate: A numerical study

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    We performed numerical simulations on the micro-dynamics of ice with air inclusions as a second phase. This provides first results of a numerical approach to model dynamic recrystallisation in polyphase crystalline aggregates. Our aim was to investigate the rheological effects of air inclusions and explain the onset of dynamic recrystallisation in the permeable firn. The simulations employ a full field theory crystal plasticity code coupled to codes simulating dynamic recrystallisation processes and predict time-resolved microstructure evolution in terms of lattice orientations, strain distribution, grain sizes and grain boundary network. Results show heterogeneous deformation throughout the simulations and indicate the importance of strain localisation controlled by air inclusions. This strain localisation gives rise to locally increased energies that drive dynamic recrystallisation and induce heterogeneous microstructures that are coherent with natural firn microstructures from EPICA Dronning Maud Land ice coring site in Antarctica. We conclude that although overall strains and stresses in firn are low, strain localisation associated with locally increased strain energies can explain the occurrence of dynamic recrystallisation

    The effect of reduced street lighting on road casualties and crime in England and Wales: controlled interrupted time series analysis.

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    BACKGROUND: Many local authorities in England and Wales have reduced street lighting at night to save money and reduce carbon emissions. There is no evidence to date on whether these reductions impact on public health. We quantified the effect of 4 street lighting adaptation strategies (switch off, part-night lighting, dimming and white light) on casualties and crime in England and Wales. METHODS: Observational study based on analysis of geographically coded police data on road traffic collisions and crime in 62 local authorities. Conditional Poisson models were used to analyse longitudinal changes in the counts of night-time collisions occurring on affected roads during 2000-2013, and crime within census Middle Super Output Areas during 2010-2013. Effect estimates were adjusted for regional temporal trends in casualties and crime. RESULTS: There was no evidence that any street lighting adaptation strategy was associated with a change in collisions at night. There was significant statistical heterogeneity in the effects on crime estimated at police force level. Overall, there was no evidence for an association between the aggregate count of crime and switch off (RR 0.11; 95% CI 0.01 to 2.75) or part-night lighting (RR 0.96; 95% CI 0.86 to 1.06). There was weak evidence for a reduction in the aggregate count of crime and dimming (RR 0.84; 95% CI 0.70 to 1.02) and white light (RR 0.89; 95% CI 0.77 to 1.03). CONCLUSIONS: This study found little evidence of harmful effects of switch off, part-night lighting, dimming, or changes to white light/LEDs on road collisions or crime in England and Wales

    On the buses: a mixed-method evaluation of the impact of free bus travel for young people on the public health

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    Background In September 2005 London introduced a policy granting young people aged  60 years. An increase in assaults largely preceded the scheme. Qualitative data suggested that the scheme increased opportunities for independent travel, social inclusion, and a sense of belonging and that it ‘normalised’ bus travel. The monetised benefits of the scheme substantially outweighed the costs, providing what the Department for Transport (DfT) considers ‘high’ value for money. Conclusion The free bus travel scheme for young people appears to have encouraged their greater use of bus transport for short trips without significant impact on their overall active travel. There was qualitative evidence for benefits on social determinants of health, such as normalisation of bus travel, greater social inclusion and opportunities for independent travel. In the context of a good bus service, universal free bus travel for young people appears to be a cost-effective contributor to social inclusion and, potentially, to increasing sustainable transport in the long term. Further research is needed on the effects of both active and other travel modes on the determinants of health; the factors that influence maintenance of travel mode change; travel as ‘social practice’; the impact of driving license changes on injury rates for young adults and the value of a statistical life for young people

    0328: Assessment of radiation exposure during cardiac device implantation: lessons learned from a multicenter registry

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    BackgroundFew data exist about radiation exposure during implantation of cardiac electrical device. No dose reference levels (DRLs) were reported.Purpose to define DRLs and to analyze factors related to an increased radiation dose delivered to patients and medical staff.Methods the Raypace study is a multicenter, prospective observational registry. Using a national database, patient demographic, procedural and radiation data were collected. Fluoroscopy time (FT) and dose-area product (DAP) were registered. Physician/staff exposure was measured using 2 real-time personal dosimeters, one worn under the lead apron and the other one worn outside the apron. Statistical analysis used log-transformation of DAP, FT and DAP/FT ratio.ResultsA total of 657 procedures from 9 institutions were reviewed. Pacemaker (PM) and cardioverter-defibrillator (ICD) implantation was performed in 481 and 176 patients, respectively. A cardiac resynchronization device was implanted in 153 patients. Fluoroscopy time was similar for PM and ICD implantations. Median fluoroscopy time was 836, 117 and 101 second and median DAP was 1410, 150 and 129 cGy.cm2 for biventricular, dual chamber and ventricular device implantation, respectively. LAO projection, in addition to AP projection, was used in 47% of the procedures. Five centers out of 9 used collimation. The median Hp (10) effective dose measured outside the lead apron was 4.6 µSv and 0.1 µSv under the lead apron.Regarding CRT implant procedures, four systems out of 6 were responsible for an increased exposure (p<0.001). DRLs were 2600, 338 and 332 cGy.cm2 for biventricular, dual chamber and ventricular device implantation, respectively.ConclusionsDAP reduction was improved with the use of latest generators but needed customized settings. Biventricular device implantation was responsible for the highest radiation exposure. However, radiation exposure during those procedures have decreased as compared to previously reported values

    The ephemeral development of C′ shear bands: A numerical modelling approach

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    C′ shear bands are ubiquitous structures in shear zones but their development is poorly understood. Previous research has determined they mostly occur in rocks with a high mechanical strength contrast. Using numerical models of viscoplastic deformation, we studied the effect of the proportion of weak phase and the phase strength contrast on C′ shear band development during simple shearing to a finite strain of 18. We found that C′ shear bands form in models with ≥5% weak phase when there is a moderate or high phase strength contrast, and they occur in all models with weak phase proportions ≥15%. Contrary to previous research, we find that C′ shear bands form when layers of weak phase parallel to the shear zone boundary rotate forwards. This occurs due to mechanical instabilities that are a result of heterogeneous distributions of stress and strain rate. C′ shear bands form on planes of low strain rate and stress, and not in sites of maximum strain rate as has previously been suggested. C′ shear bands are ephemeral and they either rotate backwards to the C plane once they are inactive or rotate into the field of shortening and thicken to form X- and triangle-shaped structures
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