Intersection AEB implementation strategies for left turn across path crashes

Abstract

Objective: Left turn across path with traffic from the opposite direction (LTAP/OD) is the second most frequent car-to-car intersection crash type after straight crossing path (SCP) in Germany and the United States. Intersection automated emergency braking (AEB) for passenger cars can address these crashes.

This study investigates 2 implementation strategies of intersection AEB addressing LTAP/OD crashes: (1) only the turning car is equipped with an intersection AEB and (2) turning and straight-heading cars are equipped with an intersection AEB. For each strategy, the influence of a safety zone around the vehicles that should not be entered is evaluated in terms of accident avoidance, injury mitigation, and change in velocity (delta-V) of remaining accidents. Results are given as a function of market penetration.

Methods: A total of 372 LTAP/OD crashes from the time series precrash matrix (PCM), a subsample of the German In-Depth Accident Study (GIDAS), were resimulated in the PRediction of Accident Evolution by Diversification of Influence factors in COmputer simulation (PRAEDICO) simulation framework. A Kudlich-Slibar rigid-body impact model and an injury risk curve derived from GIDAS were used to predict remaining moderate to fatal (Maximum Abbreviated Injury Scale [MAIS] 2?+?F) injuries among car occupants.

Results: With a safety zone of 0.2 m, when the turning vehicle only was equipped with an intersection AEB, 59% of the crashes were avoided at a 100% market penetration. With both vehicles equipped the percentage increased to 77%. MAIS 2?+?F injured occupants were reduced by 60 and 76%, respectively. Considering both the turning and the straight-heading vehicles, the delta-V decreased strongly with market penetration in remaining left-side impacts but only slightly in remaining frontal and right-side impacts. Eliminating the safety zone substantially decreases effectiveness in all conditions.

Conclusions: Implementation strategy and safety zone definition strongly influence the real-life performance of intersection AEB. AEB should be applied not only for the turning vehicle but also for the straight-going vehicle to benefit from the full potential. Situationally appropriate safety zone definitions, in line with human hazard perception, need more attention and are a key to balance true positive and false positive performance. Remaining delta-V does not decrease broadly; hence, there is no evidence that future LTAP/OD crashes will be generally of lower severity. This highlights the need for continuous development of in-crash protection.     

Erratum to: Food and feed supply and waste disposal in the industrialising city of Vienna (1830–1913): a special focus on urban nitrogen flows

Regional Environmental Change -     

Ambient air concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans in Ohio: Sources and health risk assessment

PCDD and PCDF were measured in air samples collected in Ohio in 1987. No 2,3,7,8-TCDD was detected in any of the samples with a detection limits of less than 240 fg/m³. Using a chemical mass balance model applied to PCDD/PCDF congener group profiles, major potential sources of these compounds to the atmosphere in Ohio were determined to be municipal solid waste combustion, and sewage sludge combustion. Cancer risk calculations for inhalation of PCDD/PCDF in ambient air in Ohio are approximately 10–6. Given the current knowledge of the health effects of exposure to PCDD/PCDF in air, there is no appreciable risk to public health for the levels of these compounds found in ambient air in Ohio.     

Prospects for future climate change and the reasons for early action

Combustion of coal, oil, and natural gas, and to a lesser extent deforestation, land-cover change, and emissions of halocarbons and other greenhouse gases, are rapidly increasing the atmospheric concentrations of climate-warming gases. The warming of approximately 0.1-0.2 degrees C per decade that has resulted is very likely the primary cause of the increasing loss of snow cover and Arctic sea ice, of more frequent occurrence of very heavy precipitation, of rising sea level, and of shifts in the natural ranges of plants and animals. The global average temperature is already approximately 0.8 degrees C above its preindustrial level, and present atmospheric levels of greenhouse gases will contribute to further warming of 0.5-1 degrees C as equilibrium is re-established. Warming has been and will be greater in mid and high latitudes compared with low latitudes, over land compared with oceans, and at night compared with day. As emissions continue to increase, both warming and the commitment to future warming are presently increasing at a rate of approximately 0.2 degrees C per decade, with projections that the rate of warming will further increase if emission controls are not put in place. Such warming and the associated changes are likely to result in severe impacts on key societal and environmental support systems. Present estimates are that limiting the increase in global average surface temperature to no more than 2-2.5 degrees C above its 1750 value of approximately 15 degrees C will be required to avoid the most catastrophic, but certainly not all, consequences of climate change. Accomplishing this will require reducing emissions sharply by 2050 and to near zero by 2100. This can only be achieved if: (1) developed nations move rapidly to demonstrate that a modem society can function without reliance on technologies that release carbon dioxide (CO2) and other non-CO2 greenhouse gases to the atmosphere; and (2) if developing nations act in the near-term to sharply limit their non-CO2 emissions while minimizing growth in CO2 emissions, and then in the long-term join with the developed nations to reduce all emissions as cost-effective technologies are developed.     

Workshop report on the extraction of foetal DNA from maternal plasma

Objective Cell free foetal DNA (cff DNA) extracted from maternal plasma is now recognized as a potential source for prenatal diagnosis but the methodology is currently not well standardized. To evaluate different manual and automated DNA extraction methods with a view to developing standards, an International Workshop was performed. Methods Three plasma pools from RhD-negative pregnant women, a DNA standard, real-time-PCR protocol, primers and probes for RHD were sent to 12 laboratories and also to one company (Qiagen, Hilden, Germany). In pre-tests, pool 3 showed a low cff DNA concentration, pool 1 showed a higher concentration and pool 2 an intermediate concentration. Results The QIAamp DSP Virus Kit, the High Pure PCR Template Preparation Kit, an in-house protocol using the QIAamp DNA Blood Mini Kit, the CST genomic DNA purification kit, the Magna Pure LC, the MDx, the M48, the EZ1 and an in-house protocol using magnetic beads for manual and automated extraction were the methods that were able to reliably detect foetal RHD. The best results were obtained with the QIAamp DSP Virus Kit. The QIAamp DNA Blood Mini Kit showed very comparable results in laboratories that followed the manufacturer's protocol and started with ≥ 500 µL plasma. One participant using the QIAamp DNA Blood Midi Kit failed to detect reliably RHD in pool 3. Conclusions This workshop initiated a standardization process for extraction of cff DNA in maternal plasma. The highest yield was obtained by the QIAamp DSP Virus Kit, a result that will be evaluated in more detail in future studies. Copyright © 2007 John Wiley & Sons, Ltd.     

Increased grooming after repeated brood care provides sanitary benefits in a clonal ant

Repeated pathogen exposure is a common threat in colonies of social insects, posing selection pressures on colony members to respond with improved disease-defense performance. We here tested whether experience gained by repeated tending of low-level fungus-exposed (Metarhizium robertsii) larvae may alter the performance of sanitary brood care in the clonal ant, Platythyrea punctata. We trained ants individually over nine consecutive trials to either sham-treated or fungus-exposed larvae. We then compared the larval grooming behavior of naive and trained ants and measured how effectively they removed infectious fungal conidiospores from the fungus-exposed larvae. We found that the ants changed the duration of larval grooming in response to both, larval treatment and their level of experience: (1) sham-treated larvae received longer grooming than the fungus-exposed larvae and (2) trained ants performed less self-grooming but longer larval grooming than naive ants, which was true for both, ants trained to fungus-exposed and also to sham-treated larvae. Ants that groomed the fungus-exposed larvae for longer periods removed a higher number of fungal conidiospores from the surface of the fungus-exposed larvae. As experienced ants performed longer larval grooming, they were more effective in fungal removal, thus making them better caretakers under pathogen attack of the colony. By studying this clonal ant, we can thus conclude that even in the absence of genetic variation between colony members, differences in experience levels of brood care may affect performance of sanitary brood care in social insects.