The potential for further controls of emissions from mobile sources in Europe

As one input to the revision of the Thematic Strategy on Air Pollution, this report presents an in-depth analysis of the factors that determine the evolution of emissions from mobile sources in Europe. In 2005, emissions from mobile (road and non-road) sources contributed about 60% to total NOx emissions in the EU, 20% to total PM2.5, and 30% to total VOC emissions. Road vehicles emitted more than 70% of NOx and VOC of all mobile sources, and more than 60% of PM2.5. From 2005 to 2010, implementation of EU legislation has reduced NOx from mobile sources by 18%, PM by 21% and VOC by 34%. For NOx, the decline is lower than the corresponding reductions from stationary sources (.26%), so that the relative importance of the transport sector has increased despite the EURO legislation. Especially for NOx, the recent drop in emissions is less than what was anticipated by the 2005 Thematic Strategy on Air Pollution. The major reason for this shortfall are problems in the implementation of NOx limit values for light duty diesel vehicles, where changes in real-life emissions did not follow the improvements in the type approval limit values. As a consequence, by 2015 NOx emissions from light duty diesel vehicles will be a factor two higher compared to a situation where real-life emissions of the EURO 2 to EURO 5 standards would have followed the trends in the type approval limit values. It is estimated that successful implementation of the EURO 6 standards for diesel vehicles (assuming 50% higher real-life emissions than the type approval value to allow for degradation over time and uncertainties in the driving cycles) should lead to a rapid drop of NOx emissions in the next few years. Up to 2020, NOx emissions from road transport would decline by 65% compared to 2005, by 80% in 2025, and by 87% in 2030. PM emissions from road transport would fall by 62% in 2020 and by 70% in 2030, and VOC by up to 80% until 2030. For PM, the majority of emissions will be caused by non-exhaust sources (tyre and brake wear, road abrasion). For non-road mobile machinery, implementation of the agreed emission controls according along the current schedule should cut NOx emissions in 2020 by 40% and in 2030 by 60% compared to 2005. Emissions from PM2.5 are projected to drop by 55% in 2020 and by 70% in 2030; the reduction for VOC emissions is estimated at 50% by 2020 and 60% until 2030. Least changes are expected from ships due to their long lifetime and the slow penetration of new technology. If these changes materialize, emissions from mobile sources would decline faster than those of stationary sources. Especially road transport would lower its share in total emissions, e.g., for NOx from 44% in 2005 to 17% in 2030, for PM from 14% to 7% and for VOC from 23% to 9%. There is a potential for further emission reductions also for non-road mobile machinery, where the introduction of Stage V controls (equivalent to the EURO VI level for NOx and the EURO V for PM emissions from heavy duty vehicles) in 2020 could cut NOx emissions from NRMM by 15% in 2030 and PM2.5 emissions by 26%. For further reductions ships and aircraft would need to contribute more. For road vehicles, the introduction of hypothetical EURO 7/VII standards after 2020, with real-world emission factors around 20% below the EURO 6/VI limit values could reduce NOx emissions from road vehicles by 13% below the baseline projection for 2030. As a big caveat, emission projections for road transport are particularly sensitive against assumptions on the effectiveness and timing of new legislation, especially for NOx from light duty diesel vehicles. For instance, if real-life emissions comply with the EURO 6 type approval values only by 2018 instead of 2015, NOx emissions from diesel light duty vehicles would be 40% higher in 2020. If the type approval limit values were fully achieved in real-life driving cycles, NOx emissions from this source would be 40% lower after 2030. If however, real-world emissions of EURO 6 vehicles would only follow the reduction rate in type approval values relative to real-life EURO 5 emissions, NOx emissions might be by 270 kt and 470 kt above the baseline in 2020 and 2030, respectively, and total NOx emissions would increase by 5% and 13%, respectively. For PM, non-exhaust emissions (road abrasion, brake and tyre wear) will become the major source in the future, and total mass of PM emissions will critically depend on the development of these sources. Implications of these further measures on air quality at urban hot spots will be reported in Part 2 of this report at a later stage

Impact of NOx vehicle emission standards failure on Air Quality in Europe

Vehicle exhaust emission standards have been tightened in the EU for several decades now, in order to protect health and the environment. This has led to a substantial decrease in total pollutant emissions, despite the growing volumes of passenger and freight transport. However, national emissions, particularly of NOx, exceed the ceilings accorded under the Gothenburg Protocol of the UNECE's Convention on Long-Range Transboundary Air Pollution (LRTAP) (EEA 2012) in twelve EU Member States. The main reasons for such exceedances are that more diesel cars have been sold than originally predicted when fixing the targets, and that diesel cars emit much more than expected under real-world driving conditions. The latter appears as a consequence of the effort to achieve high fuel efficiency. While this has largely helped to control CO2 emissions, it was to the detriment of NOx. In this study we estimate what the impact of the different vehicle emission standards has been so far and to predict what the impact of upcoming emission standards will be in the future, using the best current knowledge on road transport activity statistics and emission factors in Europe. We present several sensitivity calculations to reflect the considerable uncertainty about the real-driving NOx emissions of diesel light duty vehicles. The results of this work can be useful in designing both limits for upcoming standards but also in assessing the impact of deviating from such limits. This is necessary in both deciding on the next steps of emission control policy and to relevant air quality prediction models

Regulation of transcriptional elongation in pluripotency and cell differentiation by the PHD-finger protein Phf5a

Pluripotent embryonic stem cells (ESCs) self-renew or differentiate into all tissues of the developing embryo and cell-specification factors are necessary to balance gene expression. Here we delineate the function of the PHD-finger protein 5a (Phf5a) in ESC self-renewal and ascribe its role in regulating pluripotency, cellular reprogramming, and myoblast specification. We demonstrate that Phf5a is essential for maintaining pluripotency, since depleted ESCs exhibit hallmarks of differentiation. Mechanistically, we attribute Phf5a function to the stabilization of the Paf1 transcriptional complex and control of RNA polymerase II elongation on pluripotency loci. Apart from an ESC-specific factor, we demonstrate that Phf5a controls differentiation of adult myoblasts. Our findings suggest a potent mode of regulation by the Phf5a in stem cells, which directs their transcriptional program ultimately regulating maintenance of pluripotency and cellular reprogramming

Quantitative Whole Body Biodistribution of Fluorescent-Labeled Agents by Non-Invasive Tomographic Imaging

When small molecules or proteins are injected into live animals, their physical and chemical properties will significantly affect pharmacokinetics, tissue penetration, and the ultimate routes of metabolism and clearance. Fluorescence molecular tomography (FMT) offers the ability to non-invasively image and quantify temporal changes in fluorescence throughout the major organ systems of living animals, in a manner analogous to traditional approaches with radiolabeled agents. This approach is best used with biotherapeutics (therapeutic antibodies, or other large proteins) or large-scaffold drug-delivery vectors, that are minimally affected by low-level fluorophore conjugation. Application to small molecule drugs should take into account the significant impact of fluorophore labeling on size and physicochemical properties, however, the presents studies show that this technique is readily applied to small molecule agents developed for far-red (FR) or near infrared (NIR) imaging. Quantification by non-invasive FMT correlated well with both fluorescence from tissue homogenates as well as with planar (2D) fluorescence reflectance imaging of excised intact organs (r2 = 0.996 and 0.969, respectively). Dynamic FMT imaging (multiple times from 0 to 24 h) performed in live mice after the injection of four different FR/NIR-labeled agents, including immunoglobulin, 20–50 nm nanoparticles, a large vascular imaging agent, and a small molecule integrin antagonist, showed clear differences in the percentage of injected dose per gram of tissue (%ID/g) in liver, kidney, and bladder signal. Nanoparticles and IgG1 favored liver over kidney signal, the small molecule integrin-binding agent favored rapid kidney and bladder clearance, and the vascular agent, showed both liver and kidney clearance. Further assessment of the volume of distribution of these agents by fluorescent volume added information regarding their biodistribution and highlighted the relatively poor extravasation into tissue by IgG1. These studies demonstrate the ability of quantitative FMT imaging of FR/NIR agents to non-invasively visualize and quantify the biodistribution of different agents over time

Snapshot photoacoustic topography through an ergodic relay of optical absorption in vivo

Photoacoustic tomography (PAT) has demonstrated versatile biomedical applications, ranging from tracking single cells to monitoring whole-body dynamics of small animals and diagnosing human breast cancer. Currently, PAT has two major implementations: photoacoustic computed tomography (PACT) and photoacoustic microscopy (PAM). PACT uses a multi-element ultrasonic array for parallel detection, which is relatively complex and expensive. In contrast, PAM requires point-by-point scanning with a single-element detector, which has a limited imaging throughput. The trade-off between the system cost and throughput demands a new imaging method. To this end, we have developed photoacoustic topography through an ergodic relay (PATER). PATER can capture a wide-field image with only a single-element ultrasonic detector upon a single laser shot. This protocol describes the detailed procedures for PATER system construction, including component selection, equipment setup and system alignment. A step-by-step guide for in vivo imaging of a mouse brain is provided as an example application. Data acquisition, image reconstruction and troubleshooting procedures are also elaborated. It takes ~130 min to carry out this protocol, including ~60 min for both calibration and snapshot wide-field data acquisition using a laser with a 2-kHz pulse repetition rate. PATER offers low-cost snapshot wide-field imaging of fast dynamics, such as visualizing blood pulse wave propagation and tracking melanoma tumor cell circulation in mice in vivo. We envision that PATER will have wide biomedical applications and anticipate that the compact size of the setup will allow it to be further developed as a wearable device to monitor human vital signs

Time-reversed adapted-perturbation (TRAP) optical focusing onto dynamic objects inside scattering media

The ability to steer and focus light inside scattering media has long been sought for a multitude of applications. At present, the only feasible strategy to form optical foci inside scattering media is to guide photons by using either implanted or virtual guide stars, which can be inconvenient and limits the potential applications. Here we report a scheme for focusing light inside scattering media by employing intrinsic dynamics as guide stars. By adaptively time-reversing the perturbed component of the scattered light, we show that it is possible to focus light to the origin of the perturbation. Using this approach, we demonstrate non-invasive dynamic light focusing onto moving targets and imaging of a time-variant object obscured by highly scattering media. Anticipated applications include imaging and photoablation of angiogenic vessels in tumours, as well as other biomedical uses

Contrasting roles of histone 3 lysine 27 demethylases in acute lymphoblastic leukaemia

T-cell acute lymphoblastic leukaemia (T-ALL) is a haematological malignancy with a dismal overall prognosis, including a relapse rate of up to 25%, mainly because of the lack of non-cytotoxic targeted therapy options. Drugs that target the function of key epigenetic factors have been approved in the context of haematopoietic disorders, and mutations that affect chromatin modulators in a variety of leukaemias have recently been identified; however, ‘epigenetic’ drugs are not currently used for T-ALL treatment. Recently, we described that the polycomb repressive complex 2 (PRC2) has a tumour-suppressor role in T-ALL. Here we delineated the role of the histone 3 lysine 27 (H3K27) demethylases JMJD3 and UTX in T-ALL. We show that JMJD3 is essential for the initiation and maintenance of T-ALL, as it controls important oncogenic gene targets by modulating H3K27 methylation. By contrast, we found that UTX functions as a tumour suppressor and is frequently genetically inactivated in T-ALL. Moreover, we demonstrated that the small molecule inhibitor GSKJ4 (ref. 5) affects T-ALL growth, by targeting JMJD3 activity. These findings show that two proteins with a similar enzymatic function can have opposing roles in the context of the same disease, paving the way for treating haematopoietic malignancies with a new category of epigenetic inhibitors.National Institutes of Health (U.S.) (Grant R37-HD04502

Temporal Variations of Skin Pigmentation in C57Bl/6 Mice Affect Optical Bioluminescence Quantitation

ABSTRACT PURPOSE: Depilation-induced skin pigmentation in C57Bl/6 mice is a known occurrence, and presents a unique problem for quantitative optical imaging of small animals, especially for bioluminescence. The work reported here quantitatively investigated the optical attenuation of bioluminescent light due to melanin pigmentation in the skin of transgenic C57B1/6 mice, modified such that luciferase expression is under the transcription control of a physiologically and pharmacologically inducible gene. PROCEDURE: Both in vivo and ex vivo experiments were performed to track bioluminescence signal attenuation through different stages of the mouse hair growth cycle. Simultaneous reflectance measurements were collected in vivo to estimate melanin levels. RESULTS: Biological variability of skin pigmentation was found to dramatically affect collected bioluminescent signal emerging through the skin of the mice. When compared to signal through skin with no pigmentation, the signal through highly-pigmented skin was attenuated an average of 90%. Correlation of reflectance signals to bioluminescence signal loss forms the basis of the proposed correction method. We observed, however, that variability in tissue composition, which results in inconsistent reflectance spectra, limits the accuracy of the correction method but can be improved by incorporating more complex analysis. CONCLUSION: Skin pigmentation is a significant variable in bioluminescent imaging, and should be considered in experimental design and implementation for longitudinal studies, and especially when sensitivity to small signal changes, or differences among animals, is required