Accelerated Sizing of a Power Split Electrified Powertrain

Component sizing generally represents a demanding and time-consuming task in the development process of electrified powertrains. A couple of processes are available in literature for sizing the hybrid electric vehicle (HEV) components. These processes employ either time-consuming global optimization techniques like dynamic programming (DP) or near-optimal techniques that require iterative and uncertain tuning of evaluation parameters like the Pontryagin's minimum principle (PMP). Recently, a novel near-optimal technique has been devised for rapidly predicting the optimal fuel economy benchmark of design options for electrified powertrains. This method, named slope-weighted energy-based rapid control analysis (SERCA), has been demonstrated producing results comparable to DP, while limiting the associated computational time by near two orders of magnitude. In this paper, sizing parameters for a power split electrified powertrain are considered that include the internal combustion engine size, the two electric motor/generator sizes, the transmission ratios, and the final drive ratio. The SERCA approach is adopted to rapidly evaluate the fuel economy capabilities of each sizing option in various driving missions considering both type-approval drive cycles and real-world driving profiles. While screening out for optimal sizing options, the implemented methodology includes drivability criteria along with fuel economy potential. Obtained results will demonstrate the agility of the developed sizing tool in identifying optimal sizing options compared to state-of-the-art sizing tools for electrified powertrains

Dispelling urban myths about default uncertainty factors in chemical risk assessment - Sufficient protection against mixture effects?

© 2013 Martin et al.; licensee BioMed Central LtdThis article has been made available through the Brunel Open Access Publishing Fund.Assessing the detrimental health effects of chemicals requires the extrapolation of experimental data in animals to human populations. This is achieved by applying a default uncertainty factor of 100 to doses not found to be associated with observable effects in laboratory animals. It is commonly assumed that the toxicokinetic and toxicodynamic sub-components of this default uncertainty factor represent worst-case scenarios and that the multiplication of those components yields conservative estimates of safe levels for humans. It is sometimes claimed that this conservatism also offers adequate protection from mixture effects. By analysing the evolution of uncertainty factors from a historical perspective, we expose that the default factor and its sub-components are intended to represent adequate rather than worst-case scenarios. The intention of using assessment factors for mixture effects was abandoned thirty years ago. It is also often ignored that the conservatism (or otherwise) of uncertainty factors can only be considered in relation to a defined level of protection. A protection equivalent to an effect magnitude of 0.001-0.0001% over background incidence is generally considered acceptable. However, it is impossible to say whether this level of protection is in fact realised with the tolerable doses that are derived by employing uncertainty factors. Accordingly, it is difficult to assess whether uncertainty factors overestimate or underestimate the sensitivity differences in human populations. It is also often not appreciated that the outcome of probabilistic approaches to the multiplication of sub-factors is dependent on the choice of probability distributions. Therefore, the idea that default uncertainty factors are overly conservative worst-case scenarios which can account both for the lack of statistical power in animal experiments and protect against potential mixture effects is ill-founded. We contend that precautionary regulation should provide an incentive to generate better data and recommend adopting a pragmatic, but scientifically better founded approach to mixture risk assessment. © 2013 Martin et al.; licensee BioMed Central Ltd.Oak Foundatio

Mechanical thrombectomy in acute basilar artery stroke: a systematic review and Meta-analysis of randomized controlled trials

Background: The evidence for mechanical thrombectomy in acute basilar artery occlusion has until now remained inconclusive with basilar artery strokes associated with high rates of death and disability. This systematic review and meta-analysis will summarize the available evidence for the effectiveness of mechanical thrombectomy in acute basilar artery occlusion compared to best medical therapy. Methods: We conducted a systematic review and meta-analysis of randomized controlled trials using Embase, Medline and the Cochrane Central Register of Controlled Trials (CENTRAL). We calculated risk ratios (RRs) and 95% confidence intervals (CIs) to summarize the effect estimates for each outcome. Results: We performed a random effects (Mantel-Haenszel) meta-analysis of the four included randomized controlled trials comprising a total of 988 participants. We found a statistically significant improvement in the rates of those with a good functional outcome (mRS 0–3, RR 1.54, 1.16–2.06, p = 0.003) and functional independence (mRS 0–2, RR 1.69, 1.05–2.71, p = 0.03) in those who were treated with thrombectomy when compared to best medical therapy alone. Thrombectomy was associated with a higher level of sICH (RR 7.12, 2.16–23.54, p = 0.001) but this was not reflected in a higher mortality rate, conversely the mortality rate was significantly lower in the intervention group (RR 0.76, 0.65–0.89, p = 0.0004). Conclusions: Our meta-analysis of the recently presented randomized controlled studies is the first to confirm the disability and mortality benefit of mechanical thrombectomy in basilar artery stroke

Erratum to: Genomic innovations, transcriptional plasticity and gene loss underlying the evolution and divergence of two highly polyphagous and invasive Helicoverpa pest species

Upon publication of the original article [1], it was noticed that Dr Papanicolaou’s surname was spelt incorrectly. The correct spelling is “Papanicolaou”, as shown in the author list of this erratum.Additional co-authors: A. Anderson, S. Asgari, P. G. Board, A. Bretschneider, P. M. Campbell, T. Chertemps, J. T. Christeller, C. W. Coppin, S. J. Downes, G. Duan, C. A. Farnsworth, R. T. Good, L. B. Han, Y. C. Han, K. Hatje, I. Horne, Y. P. Huang, D. S. T. Hughes, E. Jacquin-Joly, W. James, S. Jhangiani, M. Kollmar, S. S. Kuwar, S. Li, N-Y. Liu, M. T. Maibeche, J. R. Miller, N. Montagne, T. Perry, J. Qu, S. V. Song, G. G. Sutton, H. Vogel, B. P. Walenz, W. Xu, H-J. Zhang, Z. Zou, P. Batterham, O. R. Edwards, R. Feyereisen, R. A. Gibbs, D. G. Heckel, A. McGrath, C. Robin, S. E. Scherer, K. C. Worley, Y. D. W

Revalidation and electronic cataract surgery audit: a Scottish survey on current practice and opinion

PURPOSE: To determine current knowledge and opinion on revalidation, and methods of cataract surgery audit in Scotland and to outline the current and future possibilities for electronic cataract surgery audit. METHODS: In 2010 we conducted a prospective, cross-sectional, Scottish-wide survey on revalidation knowledge and opinion, and cataract audit practice among all senior NHS ophthalmologists. Results were anonymised and recorded manually for analysis. RESULTS: In all, 61% of the ophthalmologists surveyed took part. Only 33% felt ready to take part in revalidation, whereas 76% felt they did not have adequate information about the process. Also, 71% did not feel revalidation would improve patient care, but 85% agreed that cataract surgery audit is essential for ophthalmic practice. In addition, 91% audit their cataract outcomes; 52% do so continuously. Further, 63% audit their subspecialist surgical results. Only 25% audit their cataract surgery practice electronically, and only 12% collect clinical data using a hospital PAS system. Funding and system incompatibility were the main reasons cited for the lack of electronic audit setup. Currently, eight separate hospital IT patient administration systems are used across 14 health boards in Scotland. CONCLUSION: Revalidation is set to commence in 2012. The Royal College of Ophthalmologists will use cataract outcome audit as a tool to ensure surgical competency for the process. Retrospective manual auditing of cataract outcome is time consuming, and can be avoided with an electronic system. Scottish ophthalmologists view revalidation with scepticism and appear to have inadequate knowledge of the process. However, they strongly agree with the concept of cataract surgery audit. The existing and future electronic applications that may support surgical audit are commercial electronic records, web-based applications, centrally funded software applications, and robust NHS connections between community and hospital

Constraints on the χ_(c1) versus χ_(c2) polarizations in proton-proton collisions at √s = 8 TeV

The polarizations of promptly produced χ_(c1) and χ_(c2) mesons are studied using data collected by the CMS experiment at the LHC, in proton-proton collisions at √s=8  TeV. The χ_c states are reconstructed via their radiative decays χ_c → J/ψγ, with the photons being measured through conversions to e⁺e⁻, which allows the two states to be well resolved. The polarizations are measured in the helicity frame, through the analysis of the χ_(c2) to χ_(c1) yield ratio as a function of the polar or azimuthal angle of the positive muon emitted in the J/ψ → μ⁺μ⁻ decay, in three bins of J/ψ transverse momentum. While no differences are seen between the two states in terms of azimuthal decay angle distributions, they are observed to have significantly different polar anisotropies. The measurement favors a scenario where at least one of the two states is strongly polarized along the helicity quantization axis, in agreement with nonrelativistic quantum chromodynamics predictions. This is the first measurement of significantly polarized quarkonia produced at high transverse momentum