Soil imaging in the field and laboratory has greatly advanced our understanding of plant root systems. Soil fungi function as important plant symbionts and decomposers of complex organic material in soil environments. For fungal hyphae, however, the application of soil imaging remains scarce, limiting our understanding of hyphal systems in soil.
View Article and Find Full Text PDFHydroxyl (OH) is the atmosphere's main oxidant removing most pollutants including methane. Its short lifetime prevents large-scale direct observational quantification. Abundances inferred using anthropogenic trace gas measurements and models yield conflicting trend estimates.
View Article and Find Full Text PDFThe Society of Toxicology 2024 meeting assembled risk assessors, epidemiologists, and toxicologists to discuss the utility of integrating epidemiologic data into the derivation of reference values. Advantages of the use of epidemiologic evidence include (i) human relevance; (ii) increased likelihood that exposure levels are relevant to risk assessment; and (iii) incorporation of uncertainties attributed to co-exposures or other population-based considerations. The workshop panelists discussed the challenges of incorporating epidemiologic evidence due to uncertain exposure measurements, confounding, heterogeneity, and inherent study design limitations.
View Article and Find Full Text PDFRing size effects on geometries and electronic structures were investigated for the (C H )M(C H ) ( = 4, 5, or 6; = 8, 7, or 6; + = 12; M = Ti-Ni) systems using density functional theory. The lowest-energy CHM structures for the early transition metals titanium, vanadium, and chromium are the experimentally known singlet (η-CH)Ti(η-CH), doublet (η-CH)V(η-CH), and singlet (η-CH)Cr, respectively. The likewise experimentally known singlet (η-CH)Ti, doublet (η-CH)V, and singlet (η-CH)Cr(η-CH) are the second-lowest-energy structures with only a small energy difference between the two vanadium structures.
View Article and Find Full Text PDFVacuum-ultraviolet (VUV) absorption spectroscopy enables electronic transitions that offer the unambiguous identification of molecules. As target molecules become more complex, multifunctional species present a great challenge to both experimental and computational spectroscopy. This research reports both experimental and theoretical studies of oxiranes.
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