Emission Projections for Long-Haul Freight Trucks and Rail in the United States through 2050.

This work develops an integrated model approach for estimating emissions from long-haul freight truck and rail transport in the United States between 2010 and 2050. We connect models of macroeconomic activity, freight demand by commodity, transportation networks, and emission technology to represent different pathways of future freight emissions. Emissions of particulate matter (PM), carbon monoxide (CO), nitrogen oxides (NOx), and total hydrocarbon (THC) decrease by 60%-70% from 2010 to 2030, as older vehicles built to less-stringent emission standards retire. Climate policy, in the form of carbon tax that increases apparent fuel prices, causes a shift from truck to rail, resulting in a 30% reduction in fuel consumption and a 10%-28% reduction in pollutant emissions by 2050, if rail capacity is sufficient. Eliminating high-emitting conditions in the truck fleet affects air pollutants by 20% to 65%; although these estimates are highly uncertain, they indicate the importance of durability in vehicle engines and emission control systems. Future infrastructure investment will be required both to meet transport demand and to enable actions that reduce emissions of air and climate pollutants. By driving the integrated model framework with two macroeconomic scenarios, we show that the effect of carbon tax on air pollution is robust regardless of growth levels.

Exploring reductions in London Underground passenger journeys following the July 2005 bombings.

We examine the reduction in London Underground passenger journeys in response to the July 2005 bombings. Using entrance data for London Underground stations between 2001 and 2007, we incorporate demand and supply factors in a multivariate time-series regression model to estimate changes in passenger journeys between different Underground lines. We find that passenger journeys fell by an average of 8.3% for the 4 months following the attacks. This amounts to an overall reduction of 22.5 million passenger journeys for that period. Passenger journeys returned to predicted levels during September 2005, yet we find evidence of reduced travel until June 2006. Our estimates controlled for other factors, including reduced Underground service provision due to damage from the attacks, economic conditions, and weather, yet substantial reductions in passenger journeys remained. Around 82% of passenger journey reductions following the 2005 attacks cannot be attributed to supply-side factors or demand-side factors such as economic conditions, weather, or the summer school-break alone. We suggest that this reduction may partially be due to an increased perception of the risk of Underground travel after the attacks.

In silico gene expression analysis in Codonopsis lanceolata root.

Expressed sequence tags (ESTs) provide valuable tools that can be used to predict the genes involved in primary and secondary metabolite synthesis. To the best of our knowledge, ESTs have not yet been developed for Codonopsis. lanceolata, and therefore, the EST referenced in this report is the first transcript for C. lanceolata. A cDNA library was constructed using the roots of C. lanceolata plants that were grown in a field. The selected 881 cDNA clones were sequenced and processed with an EST pipeline, resulting in 636 unique sequences, including 517 singletons and 119 contig sequences. Using bioinformatics tools, 81% of the EST sequence was putatively annotated. Data for unique transcripts were mined from biological databases and functionally classified using gene ontology (GO), the Kyoto Encyclopedia of Genes and Genomes Orthology, KEGG pathway maps, and protein family. The GO-based analyses were examined in terms of biotic and abiotic stress response, transport, cellular component organization, biogenesis, and secondary metabolic processes. The KEGG-based analyses of most transcripts were sorted by carbohydrate metabolism, energy metabolism, and biosynthesis of secondary metabolites. Five randomly-selected putative genes were used for an expression study using various stresses such as salt, H(2)O(2), salicylic acid, and methyl jasmonic acid. Mined data were organized in "The Codonopsis EST Database" (www.bioherbs.khu.ac.kr/Codonopsis).

Comparative analysis of expressed sequence tags (ESTs) of ginseng leaf.

The expressed sequence tags (ESTs) referenced in this report are the first transcriptomes in a leaf from a half-shade ginseng plant. A cDNA library was constructed from samples of the leaves of 4-year-old Panax ginseng plants, which were cultured in a field. The 2,896 P. ginseng cDNA clones represent 1,576 unique sequences, consisting of 1,167 singletons and 409 contig sequences. BLAST comparisons of the cDNAs in GenBank's non-redundant databases revealed that 2,579 of the 2,896 cDNAs (89.1%) exhibited a high degree of sequence homology to genes from other organisms. The majority of the identified transcripts were found to be genes related with energy, metabolism, subcellular localization, and protein synthesis and transport. The chlorophyll a/b-binding protein ESTs in the ginseng leaf samples manifested a substantially higher level of expression than was observed in other plant leaves. The ESTs involved in ginsenoside biosynthesis were also identified and discussed.

Biochemical interactions between proteins and mat1 cis-acting sequences required for imprinting in fission yeast.

DNA recombination required for mating type (mat1) switching in Schizosaccharomyces pombe is initiated by mat1 imprinting. The imprinting event is regulated by mat1 cis-acting elements and by several trans-acting factors, including swi1 (for switch), swi3, swi7, and sap1. swi1 and swi3 were previously shown to function in dictating unidirectional mat1 DNA replication by controlling replication fork movement around the mat1 region and, second, by pausing fork progression around the imprint site. With biochemical studies, we investigated whether the trans-acting factors function indirectly or directly by binding to the mat1 cis-acting sequences. First, we report the identification and DNA sequence of the swi3 gene. swi3 is not essential for viability, and, like the other factors, it exerts a stimulatory effect on imprinting. Second, we showed that only Swi1p and Swi3p interact to form a multiprotein complex and that complex formation did not require their binding to a DNA region defined by the smt-0 mutation. Third, we found that the Swi1p-Swi3p complex physically binds to a region around the imprint site where pausing of replication occurs. Fourth, the protein complex also interacted with the mat1-proximal polar terminator of replication (RTS1). These results suggest that the stimulatory effect of swi1 and swi3 on switching and imprinting occurs through interaction of the Swi1p-Swi3p complex with the mat1 regions.

The Rad27 (Fen-1) nuclease inhibits Ty1 mobility in Saccharomyces cerevisiae.

Although most Ty1 elements in Saccharomyces cerevisiae are competent for retrotransposition, host defense genes can inhibit different steps of the Ty1 life cycle. Here, we demonstrate that Rad27, a structure-specific nuclease that plays an important role in DNA replication and genome stability, inhibits Ty1 at a post-translational level. We have examined the effects of various rad27 mutations on Ty1 element retrotransposition and cDNA recombination, termed Ty1 mobility. The point mutations rad27-G67S, rad27-G240D, and rad27-E158D that cause defects in certain enzymatic activities in vitro result in variable increases in Ty1 mobility, ranging from 4- to 22-fold. The C-terminal frameshift mutation rad27-324 confers the maximum increase in Ty1 mobility (198-fold), unincorporated cDNA, and insertion at preferred target sites. The null mutation differs from the other rad27 alleles by increasing the frequency of multimeric Ty1 insertions and cDNA recombination with a genomic element. The rad27 mutants do not markedly alter the levels of Ty1 RNA or the TyA1-gag protein. However, there is an increase in the stability of unincorporated Ty1 cDNA in rad27-324 and the null mutant. Our results suggest that Rad27 inhibits Ty1 mobility by destabilizing unincorporated Ty1 cDNA and preventing the formation of Ty1 multimers.