Assigning machinery power values for estimating ship exhaust emissions: Comparison of auxiliary power schemes.

While ship exhaust emissions can be calculated at both large scales and fine resolutions due to the availability of activity data from the Automatic Identification System, there are still uncertainties in the assignment of ship engine and boiler power, which then leads to uncertainties in the estimated emissions. Reliable information is usually available for main engines, including engine type and installed power, and physical models exist for estimating propulsive power requirements. However, similar models are not available for estimating auxiliary power requirements. This study examines methods for calculating the actual operating power of auxiliary engines and auxiliary boilers. Earlier approaches assumed that installed auxiliary engine power increased in proportion to installed main engine power. Auxiliary-to-main engine power ratios were specified by ship type, and load factors were specified by ship type and operating mode. Auxiliary boiler power was generally not differentiated by ship size. More recent approaches are based on extensive ship survey data, and give tables of auxiliary engine and auxiliary boiler power binned against ship type, ship size and operating mode. These surveys show that auxiliary power does not necessarily increase with ship size or main engine power. A revised approach based on the recent data sources is adopted and applied to a case study of four ports in southeast Australia. The revised approach is informed by a local survey of ships to investigate auxiliary power demand. Comparisons are made of the impact of the different approaches on the magnitude and spatial distribution of the emissions.

The mortality effect of ship-related fine particulate matter in the Sydney greater metropolitan region of NSW, Australia.

This study investigates the mortality effect of primary and secondary PM2.5 related to ship exhaust in the Sydney greater metropolitan region of Australia. A detailed inventory of ship exhaust emissions was used to model a) the 2010/11 concentration of ship-related PM2.5 across the region, and b) the reduction in PM2.5 concentration that would occur if ships used distillate fuel with a 0.1% sulfur content at berth or within 300 km of Sydney. The annual loss of life attributable to 2010/11 levels of ship-related PM2.5 and the improvement in survival associated with use of low-sulfur fuel were estimated from the modelled concentrations. In 2010/11, approximately 1.9% of the region-wide annual average population weighted-mean concentration of all natural and human-made PM2.5 was attributable to ship exhaust, and up to 9.4% at suburbs close to ports. An estimated 220 years of life were lost by people who died in 2010/11 as a result of ship exhaust-related exposure (95% CIß: 140-290, where CIß is the uncertainty in the concentration-response coefficient only). Use of 0.1% sulfur fuel at berth would reduce the population weighted-mean concentration of PM2.5 related to ship exhaust by 25% and result in a gain of 390 life-years over a twenty year period (95% CIß: 260-520). Use of 0.1% sulfur fuel within 300 km of Sydney would reduce the concentration by 56% and result in a gain of 920 life-years over twenty years (95% CIß: 600-1200). Ship exhaust is an important source of human exposure to PM2.5 in the Sydney greater metropolitan region. This assessment supports intervention to reduce ship emissions in the GMR. Local strategies to limit the sulfur content of fuel would reduce exposure and will become increasingly beneficial as the shipping industry expands. A requirement for use of 0.1% sulfur fuel by ships within 300 km of Sydney would provide more than twice the mortality benefit of a requirement for ships to use 0.1% sulfur fuel at berth.

A 3'UTR pumilio-binding element directs translational activation in olfactory sensory neurons.

Prolonged stimulation leads to specific and stable changes in an animal's behavior. In interneurons, this plasticity requires spatial and temporal control of neuronal protein synthesis. Whether such translational control occurs in sensory neurons is not known. Adaptation of the AWC olfactory sensory neurons of C. elegans requires the cGMP-dependent protein kinase EGL-4. Here, we show that the RNA-binding PUF protein FBF-1 is required in the adult AWC for adaptation. In the odor-adapted animal, it increases translation via binding to the egl-4 3' UTR. Further, the PUF protein may localize translation near the sensory cilia and cell body. Although the RNA-binding PUF proteins have been shown to promote plasticity in development by temporally and spatially repressing translation, this work reveals that in the adult nervous system, they can work in a different way to promote experience-dependent plasticity by activating translation in response to environmental stimulation.