Presented in this study is an empirical analysis of embodied carbon dioxide emissions induced by fossil fuel combustion for the world divided into three supra-national coalitions, i.e., G7, BRIC, and ...the rest of the world (ROW), via the application of a multi-region input–output modeling for 2004. Embodied emission intensities for the three coalitions are calculated and compared, with market exchange rate and purchase power parity separately used to investigate the difference between nominal and real production efficiencies. Emissions embodied in different economic activities such as production, consumption, import, and export are calculated and analyzed accordingly, and remarkable carbon trade imbalances associated with G7 (surplus of 1.53 billion tons, or 36% its traded emissions) and BRIC (deficit of 1.37 billion tons, or 51% its traded emissions) and approximate balance with ROW (deficit of 0.16 billion tons, or 3% its traded emissions) are concretely revealed. Carbon leakages associated with industry transfer and international trades are illustrated in terms of impacts on global climate policies. The last but not least, per capita consumption based emissions for G7, BRIC, and ROW are determined as 12.95, 1.53, and 2.22 tons, respectively, and flexible abatement policies as well as equity on per capita entitlement are discussed.
► We compare the embodied CO
2 emissions in 2004 for G7, BRIC, and ROW. ► Emissions embodied in production, consumption, import, and export are investigated. ► Considerable CO
2 trade surplus and deficit are obtained by G7 and BRIC, respectively. ► Per head embodied emissions are 13, 1.5, and 2.2 tons for G7, BRIC, and ROW, respectively.
The human microbial communities are associated with many human diseases such as obesity, diabetes and inflammatory bowel disease. High-throughput sequencing technology has been widely used to ...quantify the microbial composition in order to understand its impacts on human health. Longitudinal measurements of microbial communities are commonly obtained in many microbiome studies. A key question in such microbiome studies is to identify the microbes that are associated with clinical outcomes or environmental factors. However, microbiome compositional data are highly skewed, bounded in 0,1), and often sparse with many zeros. In addition, the observations from repeated measures in longitudinal studies are correlated. A method that takes into account these features is needed for association analysis in longitudinal microbiome data.
In this paper, we propose a two-part zero-inflated Beta regression model with random effects (ZIBR) for testing the association between microbial abundance and clinical covariates for longitudinal microbiome data. The model includes a logistic regression component to model presence/absence of a microbe in the samples and a Beta regression component to model non-zero microbial abundance, where each component includes a random effect to account for the correlations among the repeated measurements on the same subject. Both simulation studies and the application to real microbiome data have shown that ZIBR model outperformed the previously used methods. The method provides a useful tool for identifying the relevant taxa based on longitudinal or repeated measures in microbiome research.
https://github.com/chvlyl/ZIBR CONTACT: hongzhe@upenn.edu.
•Polyploidy is a common evolutionary feature in all eukaryotes especially in plants.•Ploidy and intergenomic hybridization induce genetic and epigenetic changes.•DNA methylation and histone ...modifications affect homoeologous gene expression.•Gene expression networks are reprogrammed by environmental and developmental cues.•Studies of polyploidy at sequence and single-cell levels will reveal mechanistic insights.
Polyploidy or whole-genome duplication occurs in some animals and many flowering plants, including many important crops such as wheat, cotton and oilseed rape. The prevalence of polyploidy in the plant kingdom suggests it as an important evolutionary feature for plant speciation and crop domestication. Studies of natural and synthetic polyploids have revealed rapid and dynamic changes in genomic structure and gene expression after polyploid formation. Growing evidence suggests that epigenetic modifications can alter homoeologous gene expression and reprogram gene expression networks, which allows polyploids to establish new cytotypes, grow vigorously and promote adaptation in local environments. Sequence and gene expression changes in polyploids have been well documented and reviewed elsewhere. This review is focused on developmental regulation and epigenetic changes including DNA methylation and histone modifications in polyploids.
Electrostatic solitary wave (ESW)-a Debye-scale structure in space plasmas-was believed to accelerate electrons. However, such a belief is still unverified in spacecraft observations, because the ESW ...usually moves fast in spacecraft frame and its interior has never been directly explored. Here, we report the first measurements of an ESW's interior, by the Magnetospheric Multiscale mission located in a magnetotail reconnection jet. We find that this ESW has a parallel scale of 5λ_{De} (Debye length), a superslow speed (99 km/s) in spacecraft frame, a longtime duration (250 ms), and a potential drop eφ_{0}/kT_{e}∼5%. Inside the ESW, surprisingly, there is no electron acceleration, no clear change of electron distribution functions, but there exist strong electrostatic electron cyclotron waves. Our observations challenge the conventional belief that ESWs are efficient at particle acceleration.
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With the aim of gathering temporal trends on bacterial epidemiology and resistance from multiple laboratories in China, the CHINET surveillance system was organized in 2005. Antimicrobial ...susceptibility testing was carried out according to a unified protocol using the Kirby-Bauer method or automated systems. Results were analyzed according to Clinical and Laboratory Standards Institute (CLSI) 2014 definitions. Between 2005 and 2014, the number of bacterial isolates ranged between 22 774 and 84 572 annually. Rates of extended-spectrum β-lactamase production among Escherichia coli isolates were stable, between 51.7 and 55.8%. Resistance of E. coli and Klebsiella pneumoniae to amikacin, ciprofloxacin, piperacillin/tazobactam and cefoperazone/sulbactam decreased with time. Carbapenem resistance among K. pneumoniae isolates increased from 2.4 to 13.4%. Resistance of Pseudomonas aeruginosa strains against all of antimicrobial agents tested including imipenem and meropenem decreased with time. On the contrary, resistance of Acinetobacter baumannii strains to carbapenems increased from 31 to 66.7%. A marked decrease of methicillin resistance from 69% in 2005 to 44.6% in 2014 was observed for Staphylococcus aureus. Carbapenem resistance rates in K. pneumoniae and A. baumannii in China are high. Our results indicate the importance of bacterial surveillance studies.
Previous studies have demonstrated that microRNA (miRNA) expression is altered in human cancer. However, the molecular mechanism underlying these changes in miRNA expression remains unclear. In this ...study, we investigated the epigenetic modification of miR-124 genes and the potential function of miR-124 in pancreatic cancer. Using pyrosequencing analysis, we found that miR-124 genes (including miR-124-1, miR-124-2 and miR-124-3) are highly methylated in pancreatic cancer tissues compared with in non-cancerous tissues. Hypermethylation mediated the silencing of miR-124, which was a frequent event in pancreatic duct adenocarcinoma (PDAC). Furthermore, miR-124 downregulation was significantly associated with worse survival of PDAC patients. Functional studies showed that miR-124 inhibited cell proliferation, invasion and metastasis. Furthermore, we characterized Rac1 as a direct target of miR-124, and miR-124 interacted with the 3'-untranslated region of Rac1, which we showed to be a putative tumor promoter in pancreatic cancer. Thus, the miR-124-mediated downregulation of Rac1 led to the inactivation of the MKK4-JNK-c-Jun pathway. Therefore, our study demonstrates that miR-124 is a tumor suppressor miRNA that is epigenetically silenced in pancreatic cancer. Our findings suggest a previously unidentified molecular mechanism involved in the progression and metastasis of pancreatic cancer.
As the world is smoothing the transition towards a low-carbon energy structure, natural gas has occupied a critical position in global energy supply. Also, globalization has catalyzed ever-increasing ...indirect energy flows in international trade. In order to present a comprehensive overview of natural gas use in globalized economy, this paper applies the systems multi-regional input-output (MRIO) analysis to track natural gas use from primary suppliers to final consumers via the links by producers in the world economy, supported by typical statistics for the year of 2011. Natural gas embodied in international trade is revealed amounting to 2722.1 bcm, in magnitude up to 90% of total gas extraction for energy use, indicating the intensive relocation of gas use by trade. 83% of traded embodied natural gas is associated with intermediate trade, mainly from leading primary suppliers, including Russia, USA and Western Asia, to dominant final consumers, like USA, EU27 and East Asia. Significant differences are found between direct and embodied natural gas flows. Consumption-based resource efficiency can break the illusion of efficiency improvements, and trade imbalance in terms of gas use can be opposite to the trade imbalance in conventional monetary terms. This paper has constructed a comprehensive analytical framework to trace natural gas flows in globalized economy for the first time, aiming to provide new insights for policy making.
•Global embodied natural gas flows are traced from a systematic perspective.•Major agents in supply chains, net importers and exporters are identified.•83% of traded embodied natural gas is associated with intermediate trade.•Russia, USA and Western Asia are leading source regions.•USA, EU27 and East Asia are dominant final producers and consumers.
The rapid development of catalysts requires a deep understanding of catalytic mechanisms. Since the experimental results have fallen short of the expectation of the optimal catalyst, the density ...functional theory (DFT) can provide invaluable mechanistic insights and predict promising catalysts. In this perspective, we briefly summarized the advantages of DFT in atomic and electronic structures for understanding electro-catalysis. Some achievements of DFT calculations were reviewed through some examples of the considered catalytic reactions (hydrogen evolution reaction, oxygen reduction reaction, nitrogen reduction reaction, and CO
2
reduction reaction). Finally, we highlighted and analyzed the opportunities and challenges in DFT calculations used for electro-catalysis. On the road towards an optimal catalyst, the design of catalysts fused with DFT calculations promises rapid advances in the coming years.
DFT calculations are indispensable for understanding the electro-catalysis through explanation of the experimental phenomena, prediction of experimental results, and guiding of the experimental investigation.
Polyploidy, or whole-genome duplication (WGD), is an important genomic feature for all eukaryotes, especially many plants and some animals. The common occurrence of polyploidy suggests an ...evolutionary advantage of having multiple sets of genetic material for adaptive evolution. However, increased gene and genome dosages in autopolyploids (duplications of a single genome) and allopolyploids (combinations of two or more divergent genomes) often cause genome instabilities, chromosome imbalances, regulatory incompatibilities, and reproductive failures. Therefore, new allopolyploids must establish a compatible relationship between alien cytoplasm and nuclei and between two divergent genomes, leading to rapid changes in genome structure, gene expression, and developmental traits such as fertility, inbreeding, apomixis, flowering time, and hybrid vigor. Although the underlying mechanisms for these changes are poorly understood, some themes are emerging. There is compelling evidence that changes in DNA sequence, cis- and trans-acting effects, chromatin modifications, RNA-mediated pathways, and regulatory networks modulate differential expression of homoeologous genes and phenotypic variation that may facilitate adaptive evolution in polyploid plants and domestication in crops.
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