Greenhouse gas emissions from U.S. crude oil pipeline accidents:1968 to 2020

Abstract Crude oil pipelines are considered as the lifelines of energy industry. However, accidents of the pipelines can lead to severe public health and environmental concerns, in which greenhouse gas (GHG) emissions, primarily methane, are frequently overlooked. While previous studies examined fugitive emissions in normal operation of crude oil pipelines, emissions resulting from accidents were typically managed separately and were therefore not included in the emission account of oil systems. To bridge this knowledge gap, we employed a bottom-up approach to conducted the first-ever inventory of GHG emissions resulting from crude oil pipeline accidents in the United States at the state level from 1968 to 2020, and leveraged Monte Carlo simulation to estimate the associated uncertainties. Our results reveal that GHG emissions from accidents in gathering pipelines (~720,000 tCO2e) exceed those from transmission pipelines (~290,000 tCO2e), although significantly more accidents have occurred in transmission pipelines (6883 cases) than gathering pipelines (773 cases). Texas accounted for over 40% of total accident-related GHG emissions nationwide. Our study contributes to enhanced accuracy of the GHG account associated with crude oil transport and implementing the data-driven climate mitigation strategies

Transcriptome variations among human embryonic stem cell lines are associated with their differentiation propensity

<div><p>Human embryonic stem cells (hESCs) have the potential to form any cell type in the body, making them attractive cell sources in drug screening, regenerative medicine, disease and developmental processes modeling. However, not all hESC lines have the equal potency to generate desired cell types <i>in vitro</i>. Significant variations have been observed for the differentiation efficiency of various human ESC lines. The precise underpinning molecular mechanisms are still unclear. In this work, we compared transcriptome variations of four hESC lines H7, HUES1, HUES8 and HUES9. We found that hESC lines have different gene expression profiles, and these differentially expressed genes (DEGs) are significantly enriched in developmental processes, such as ectodermal, mesodermal and endodermal development. The enrichment difference between hESC lines was consistent with its lineage bias. Among these DEGs, some pluripotency factors and genes involved in signaling transduction showed great variations as well. The pleiotropic functions of these genes in controlling hESC identity and early lineage specification, implicated that different hESC lines may utilize distinct balance mechanisms to maintain pluripotent state. When the balance is broken in a certain environment, gene expression variation between them could impact on their different lineage specification behavior.</p></div

An inventory of greenhouse gas emissions due to natural gas pipeline incidents in the United States and Canada from 1980s to 2021

Abstract Natural gas is believed to be a critical transitional energy source. However, natural gas pipelines, once failed, will contribute to a large amount of greenhouse gas (GHG) emissions, including methane from uncontrolled natural gas venting and carbon dioxide from flared natural gas. However, the GHG emissions caused by pipeline incidents are not included in the regular inventories, making the counted GHG amount deviate from the reality. This study, for the first time, establishes an inventory framework for GHG emissions including all natural gas pipeline incidents in the two of the largest gas producers and consumers in North America (United States and Canada) from 1980s to 2021. The inventory comprises GHG emissions resulting from gathering and transmission pipeline incidents in a total of 24 states or regions in the United States between 1970 and 2021, local distribution pipeline incidents in 22 states or regions between 1970 and 2021, as well as natural gas pipeline incidents in a total of 7 provinces or regions in Canada between 1979 and 2021. These datasets can improve the accuracy of regular emission inventories by covering more emission sources in the United States and Canada and provide essential information for climate-oriented pipeline integrity management

Expression variations of genes involved in IGF/PI3K, FGFMAPK, TGF-β and Wnt signaling pathways in hESC lines H7, HUES1, HUES8 and HUES9.

<p>(A) Fold change of BMP, WNT, FDZ and FGF family genes among the four lines. * represents genes differentially expressed at least between two cell lines by FC > 2 and FDR < 0.01. (B) Percentage of DEGs in PUGs and PDGs of the four signaling pathways. Statistically significant were analyzed by student's t-test. (C) Line chart showing fold change of differentially expressed WNT family genes and inhibitor DKK1 in Wnt signaling pathway in the four cell lines. (D) Line chart depicting fold change of BMP4 and pluripotent factors POU5F1 and NANOG in the four cell lines. Fold change of each gene mentioned here was normalized by the minimum CPM of the gene among the four lines.</p

Highly expressed genes in hESC lines H7, HUES1, HUES8 and HUES9.

<p>(A) Venn diagram showing top 1000 highly expressed genes ranked by expression level in the four cell lines. Expression level were normalized by transcripts per million (TPM). (B) GO-slim biological process enrichment analysis for 762 commonly high expressed genes shared in the four cell lines. (C) GO-slim biological process enrichment analysis for non-shared high expressed genes in the four cell lines.</p

TPM value and ranking level of lineage-specific genes in hESC lines H7, HUES1, HUES8 and HUES9.

<p>TPM value and ranking level of lineage-specific genes in hESC lines H7, HUES1, HUES8 and HUES9.</p

Transcriptional variability among hESC lines H7, HUES1, HUES8 and HUES9.

<p>(A) GO-slim biological process enrichment analysis of DEGs at least between two lines. Result shows that these global DEGs are significant enriched in developmental process. (B) Histogram depicting number of DEGs between any two cell lines. HUES1 and HUES8 have the least DEGs compared to other two-two compares. (C) GO-slim biological process enrichment analysis of DEGs between HUES9 and HUES1. (D) GO-slim biological process enrichment analysis of DEGs between HUES9 and HUES8. Although HUES1 is female while HUES8 is male, their expression profiles are more similar than other cell lines. GO-slim enrichment analysis indicates that their DEGs show no significant enrichment in biological process. Compared to HUES9, upregulated genes (logFC > 1 and FDR < 0.01) in these two cell lines exhibit significant enrichment in endoderm development (Note: HUES1 and HUES8 refer to GO complete biological process data, <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192625#pone.0192625.s013" target="_blank">S7 Table</a>) while upregulated genes of HUES9 significantly enriched in nervous system development and ectoderm development. Other results of GO-slim biological process enrichment analysis please see <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0192625#pone.0192625.s002" target="_blank">S2 Fig</a>.</p

Results of reads mapping to genes expressed in hESC lines H7, HUES1, HUES8 and HUES9.

<p>(A) A histogram showing the number of reads uniquely aligned to GRCh37/hg19 genome and assigned to transcriptome for each line with replicates. (B) A pie chart depicting percentage of distinct bio-types annotated in the total genes expressed in hESC lines H7, HUES1, HUES8 and HUES9 after filtering out lowly expressed genes. Number in brackets represent amount of genes in the biotype. CPM of a gene in two or more libraries are larger than 1 considered as expressed genes, otherwise as lowly expressed genes filtered out.</p