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André J. Simpson
Researcher at University of Toronto
Publications - 273
Citations - 11242
André J. Simpson is an academic researcher from University of Toronto. The author has contributed to research in topics: Nuclear magnetic resonance spectroscopy & Soil organic matter. The author has an hindex of 53, co-authored 244 publications receiving 9267 citations. Previous affiliations of André J. Simpson include Ohio State University & University of Birmingham.
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Microbially derived inputs to soil organic matter: are current estimates too low?
TL;DR: The contributions of microbial biomass to soil organic matter appear to be much higher than the 1-5% reported by other researchers, and organic matter is intimately linked to nutrient release and transport in soils, nitrogen turnover rates, contaminant fate, soil quality, and fertility.
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Humic Substances in Soils: Are They Really Chemically Distinct?
TL;DR: It is suggested that the vast majority of operationally defined humic material in soils is a very complex mixture of microbial and plant biopolymers and their degradation products but not a distinct chemical category.
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A ubiquitous tire rubber–derived chemical induces acute mortality in coho salmon
Zhenyu Tian,Haoqi Zhao,Katherine T. Peter,Melissa Gonzalez,Jill Wetzel,Christopher Wu,Ximin Hu,Jasmine Prat,Emma Mudrock,Rachel Hettinger,Allan E. Cortina,Rajshree Ghosh Biswas,Flávio Vinicius Crizóstomo Kock,Ronald Soong,Amy Jenne,Bowen Du,Fan Hou,Huan He,Rachel A. Lundeen,Alicia N. Gilbreath,Rebecca Sutton,Nathaniel L. Scholz,Jay W. Davis,Michael C. Dodd,André J. Simpson,Jenifer K. McIntyre,Edward P. Kolodziej +26 more
TL;DR: Results reveal unanticipated risks of 6PPD antioxidants to an aquatic species and imply toxicological relevance for dissipated tire rubber residues, and identify a highly toxic quinone transformation product of N-(1,3-dimethylbutyl)-N′-phenyl-p- Phenylenediamine (6PPD), a globally ubiquitous tire rubber antioxidant.
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Chemical and mineralogical controls on humic acid sorption to clay mineral surfaces
TL;DR: In this article, a batch sorption experiment with peat humic acid (PHA) was carried out with two types of clay minerals (kaolinite and montmorillonite) under various solution conditions to determine the influence of solution chemistry (e.g., ionic strength, pH and solution cation) and mineralogy on PHA sorption to mineral surfaces.