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- Frontiers in Chemistry
- Sponsoring Org:
- National Science Foundation
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Predicting the embodied scope 3 carbon dioxide equivalent (CO2e) emissions from purchased electricity for end users in the United States is challenging due to electricity transmission within interconnected power grids. Existing methods only focus on large aggregation areas, thereby ignoring potentially significant emission factor (EF) variations, so this study proposes a novel method to translate the CO2e emissions from the balancing authority (BA)-level to the county-level by utilizing explicit finite-difference theory for electricity flow predictions, and then employing economic input–output theory to evaluate the scope 3 embodied lifecycle CO2e emissions. Results show that the generation-based EFs at the BA-level range from 0.007 to 0.905 MT-CO2e/MWh with a mean value of 0.400 MT-CO2e/MWh and a standard deviation of 0.229 MT-CO2e/MWh. The consumption-based EFs at the BA-level range from 0.008 to 0.836 MT-CO2e/MWh with a mean value of 0.378 MT-CO2e/MWh and a standard deviation of 0.019 MT-CO2e/MWh. Results also show that sixteen BA consumption-based EFs deviate by more than 20% compared to their generation-based EFs, which indicates the significance of accounting for electricity interchanges in emissions quantification processes. A larger range of possible consumption-based EFs is revealed at the county-level: 0.007 to 0.902 MT-CO2e/MWh, with a mean value of 0.452 MT-CO2e/MWh andmore »
Bile acids and ceramide overcome the entry restriction for GII.3 human norovirus replication in human intestinal enteroids
Human noroviruses (HuNoVs) cause sporadic and epidemic outbreaks of gastroenteritis in all age groups worldwide. We previously reported that stem cell-derived human intestinal enteroid (HIE) cultures support replication of multiple HuNoV strains and that some strains (e.g., GII.3) replicate only in the presence of bile. Heat- and trypsin-treatment of bile did not reduce GII.3 replication, indicating a nonproteinaceous component in bile functions as an active factor. Here we show that bile acids (BAs) are critical for GII.3 replication and replication correlates with BA hydrophobicity. Using the highly effective BA, glycochenodeoxycholic acid (GCDCA), we show BAs act during the early stage of infection, BA-dependent replication in HIEs is not mediated by detergent effects or classic farnesoid X receptor or Takeda G protein-coupled receptor 5 signaling but involves another G protein-coupled receptor, sphingosine-1-phosphate receptor 2, and BA treatment of HIEs increases particle uptake. We also demonstrate that GCDCA induces multiple cellular responses that promote GII.3 replication in HIEs, including enhancement of 1) endosomal uptake, 2) endosomal acidification and subsequent activity of endosomal/lysosomal enzyme acid sphingomyelinase (ASM), and 3) ceramide levels on the apical membrane. Inhibitors of endosomal acidification or ASM reduce GII.3 infection and exogenous addition of ceramide alone permits infection. Furthermore,more »
ABSTRACT On and within most sites across an animal's body live complex communities of microorganisms. These microorganisms perform a variety of important functions for their hosts, including communicating with the brain, immune system and endocrine axes to mediate physiological processes and affect individual behaviour. Microbiome research has primarily focused on the functions of the microbiome within the gastrointestinal tract (gut microbiome) using biomedically relevant laboratory species (i.e. model organisms). These studies have identified important connections between the gut microbiome and host immune, neuroendocrine and nervous systems, as well as how these connections, in turn, influence host behaviour and health. Recently, the field has expanded beyond traditional model systems as it has become apparent that the microbiome can drive differences in behaviour and diet, play a fundamental role in host fitness and influence community-scale dynamics in wild populations. In this Review, we highlight the value of conducting hypothesis-driven research in non-model organisms and the benefits of a comparative approach that assesses patterns across different species or taxa. Using social behaviour as an intellectual framework, we review the bidirectional relationship between the gut microbiome and host behaviour, and identify understudied mechanisms by which these effects may be mediated.
Ceria and its solid solutions play a vital role in several industrial processes and devices. These include solar energy-to-fuel conversion, solid oxide fuel and electrolyzer cells, memristors, chemical looping combustion, automotive 3-way catalysts, catalytic surface coatings, supercapacitors and recently, electrostrictive devices. An attractive feature of ceria is the possibility of tuning defect-chemistry to increase the effectiveness of the materials in application areas. Years of study have revealed many features of the long-range, macroscopic characteristics of ceria and its derivatives. In this review we focus on an area of ceria defect chemistry which has received comparatively little attention – defect-induced local distortions and short-range associates. These features are non-periodic in nature and hence not readily detected by conventional X-ray powder diffraction. We compile the relevant literature data obtained by thermodynamic analysis, Raman spectroscopy, and X-ray absorption fine structure (XAFS) spectroscopy. Each of these techniques provides insight into material behavior without reliance on long-range periodic symmetry. From thermodynamic analyses, association of defects is inferred. From XAFS, an element-specific probe, local structure around selected atomic species is obtained, whereas from Raman spectroscopy, local symmetry breaking and vibrational changes in bonding patterns is detected. We note that, for undoped ceria and its solid solutions,more »
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