This paper aims to study the characteristics of greenhouse gas (GHG) emissions from heavy-duty trucks in the Beijing-Tianjin-Hebei (BTH) region, which is located in Northern China. The multiyear emissions of GHG (CO 2 , CH 4 and N 2 O) from heavy-duty trucks fueled by diesel and natural gas during the period of 2006-2015 were compared and analyzed. The results show that the GHG emissions from heavy-duty trucks increase with time, which is consistent with the trend of the population growth. The total amount of carbon dioxide equivalence (CO 2 e) emissions in the BTH region was about 5.12 × 10 6 t in 2015. Among the three sub-regions, Hebei possesses the largest number of heavy-duty trucks due to the size of its heavy-duty industries. As a consequence, the GHG emissions are about 10 times compared to Beijing and Tianjin. Tractor trailers account for the major proportion of heavy-duty trucks and hence contribute to about 74% of GHG emissions. Diesel-and liquefied natural gas (LNG)-powered heavy-duty trucks can reduce GHG emissions more effectively under current national standard IV than can the previous standard. The widespread utilization of the alternative fuel of LNG to mitigate emissions must be accompanied with engine technology development in China. This study has provided new insight on management methods and the policy-making as regards trucks in terms of environmental demand.
The morphology, morphogenesis, and 18S rRNA gene sequence of a soil hypotrichous ciliate Perisincirra paucicirrata, isolated from north China, were investigated. Perisincirra paucicirrata differs from its congeners in: (1) having a body length to width ratio in vivo of 4:1, (2) its adoral zone occupying between 15% and 25% of the total body length, and (3) the presence of two parabuccal cirri, three left (with 10-16 cirri each) and two right marginal rows (with 14-24 cirri each), and three dorsal kineties. Our study offers a first attempt to begin to map the morphogenetic processes of the genus, which are mainly characterised by the following: the formation of four frontal ventral transverse anlagens for each daughter cell, with the proter's anlage I originating from the reorganised anterior part of the parental paroral; the paroral and endoral anlage developed from the reorganised old endoral and do not contribute the first frontal cirrus; the frontoventral transverse anlage I contributing the left frontal cirrus; anlage II generating the middle frontal and the buccal cirri; anlage III developing the right frontal cirrus and the anterior parabuccal cirrus; and anlage IV contributing the posterior parabuccal cirrus. As an additional contribution, we judge that the inner one or the two right rows of P. kahli and P. longicirrata are marginal rows. Phylogenetic analysis based on SSU rDNA sequences suggests that Perisincirra is related to sporadotrichids, but provides no credible evidence for its taxonomic position.
The morphology, infraciliature, and molecular phylogeny of two novel spirotrich ciliates, Caryotricha rariseta n. sp. and Discocephalus pararotatorius n. sp., isolated from coastal waters of China, were investigated. Caryotricha rariseta n. sp. differs from its congeners mainly in possessing seven sparsely ciliated cirral rows that are conspicuously shortened posteriorly and three transverse cirri aligned in a row. Discocephalus pararotatorius n. sp. is characterized by the conspicuous spine-like dorsal cilia, one extra (endoral?) membrane, and seven frontal, six ventral, and seven posterolateral marginal cirri. The small subunit rRNA gene was sequenced for both species. Complete SSU rRNA gene sequences of two Caryotricha spp. (including C. rariseta n. sp.) and two Discocephalus spp. (including D. pararotatorius n. sp.), along with those of 40 other ciliates, were used to determine their molecular phylogeny using maximum likelihood, neighbor joining and maximum parsimony analyses. The two Caryotricha species cluster with Kiitricha marina in the well-supported Protohypotrichia clade that is basal to the main spirotrich assemblage. The two discocephalids form a clade that is sister to the Hypotrichia.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.