All cells produce extracellular vesicles (EVs). These biological packages contain complex mixtures of molecular cargo and have a variety of functions, including interkingdom communication. Recent ...discoveries highlight the roles microbial EVs may play in the environment with respect to interactions with plants as well as nutrient cycling. These studies have also identified molecules present within EVs and associated with EV surfaces that contribute to these functions. In parallel, studies of engineered nanomaterials have developed methods to track and model small particle behavior in complex systems and measure the relative importance of various surface features on transport and function. While studies of EV behavior in complex environmental conditions have not yet employed transdisciplinary approaches, it is increasingly clear that expertise from disparate fields will be critical to understand the role of EVs in these systems. Here, we outline how the convergence of biology, soil geochemistry, and colloid science can both develop and address questions surrounding the basic principles governing EV-mediated interkingdom interactions.
Extracellular vesicles are a ubiquitous but often overlooked biological component of all natural environments. Convergent interdisciplinary research highlights an effective approach to understand their properties and functions.
Scant attention has been paid to cycling of total mercury (THg) and methylmercury (MeHg) in agriculturally intensive watersheds. Monitoring of Hg and MeHg in river basins provides valuable ...information on the efficacy of environmental policy and the impacts of land use and climate change on Hg fluxes and biogeochemistry. We report on Hg and MeHg yields in the Cedar River (Iowa), a major tributary of the Upper Mississippi River, and on Hg biogeochemistry in a floodplain of the lower Cedar River, with emphasis on Hg cycling in groundwater and wetland ponds. For the period 2016 to 2018, total Hg yields for the 21,000 km
2
Cedar River watershed ranged from 2.6 to 6.9 μg m
−2
yr
−1
, or 25% to 70% of estimated wet deposition, and MeHg yields ranged from 0.09 to 0.18 μg m
−2
yr
−1
. High watershed transfer efficiencies for THg are driven by soil erosion and suspended sediment delivery. Policies and land management practices targeting soil conservation are thus likely to have significant impacts on downstream transport of Hg. Within alluvial groundwaters, Hg and MeHg concentrations were highly spatiotemporally variable, ranging from 0.5 to 2.0 ng/L for THg and 0.03–1.50 ng/L for MeHg. Microtopography exerted strong control on groundwater geochemistry and Hg biogeochemical cycling, with groundwater sampled from lower lying swales exhibiting less dissolved oxygen (DO), higher conductivity, higher dissolved organic carbon (DOC), and higher THg and MeHg. The alluvial aquifer exhibits high hydrologic connectivity with the river and groundwater THg and MeHg concentrations responded rapidly to hydrologic events, with MeHg concentrations increasing with a rising water table. Concentrations of THg and MeHg in wetland ponds were elevated compared to groundwater and most strongly correlated with DOC and UV-absorbance. Methylation potentials in pond sediments were among the highest reported for freshwater sediments, up to 0.15 d
−1
, which we hypothesize to be linked to high primary productivity associated with nutrient enrichment. Floodplain groundwaters and wetlands constitute important ecosystem control points for downstream MeHg delivery, the magnitude of which is sensitive to changing hydroclimate, especially flood frequency.
Mercury (Hg)-impaired aquatic ecosystems often receive multiple inputs of different Hg species with varying potentials for transformation and bioaccumulation. Over time, these distinct input pools of ...Hg homogenize in their relative distributions and bioaccumulation potentials as a result of biogeochemical processes and other aging processes within the ecosystem. This study sought to evaluate the relative time scale for homogenization of multiple Hg inputs to wetlands, information that is relevant for ecosystem management strategies that consider Hg source apportionment. We performed experiments in simulated freshwater wetland mesocosms that were dosed with four isotopically labeled mercury forms: two dissolved forms (Hg2+ and Hg-humic acid) and two particulate forms (nano-HgS and Hg adsorbed to FeS). Over the course of one year, we monitored the four Hg isotope endmembers for their relative distribution between surface water, sediment, and fish in the mesocosms, partitioning between soluble and particulate forms, and conversion to methylated mercury (MeHg). We also evaluated the reactivity and mobility of Hg through sequential selective extractions of sediment and the uptake flux of aqueous Hg in a diffusive gradient in thin-film (DGT) passive samplers. We observed that the four isotope spikes were relatively similar in surface water concentration (ca. 3000 ng/L) immediately after spike addition. At 1–3 months after dosing, Hg concentrations were 1–50 ng/L and were greater for the initially dissolved isotope endmembers than the initially particulate endmembers. In contrast, the Hg isotope endmembers in surface sediments were similar in relative concentration within 2 months after spike addition. However, the uptake fluxes of Hg in DGT samplers, deployed in both the water column and surface sediment, were generally greater for initially dissolved Hg endmembers and lower for initially particulate endmembers. At one year postdosing, the DGT-uptake fluxes were converging toward similar values between the Hg isotope endmembers. However, the relative distribution of isotope endmembers was still significantly different in both the water column and sediment (p < 0.01 according to one-way ANOVA analysis). In contrast, selective sequential extractions resulted in a homogeneous distribution, with >90% of each endmember extracted in the KOH fraction, suggesting that Hg species were associated with sediment organic matter. For MeHg concentrations in surface sediment and fish, the relative contributions from each endmember were significantly different at all sampling time points. Altogether, these results provide insights into the time scales of distribution for different Hg species that enter a wetland ecosystem. While these inputs attain homogeneity in concentration in primary storage compartments (i.e., sediments) within weeks after addition, these input pools remain differentiated for more than one year in terms of reactivity for passive samplers, MeHg concentration, and bioaccumulation.
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4.
A Diverse View of Science to Catalyse Change Urbina‐Blanco, César A.; Jilani, Safia Z.; Speight, Isaiah R. ...
Angewandte Chemie,
October 12, 2020, Volume:
132, Issue:
42
Journal Article
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.
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FZAB, GEOZS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
A Diverse View of Science to Catalyse Change Urbina‐Blanco, César A.; Jilani, Safia Z.; Speight, Isaiah R. ...
Angewandte Chemie (International ed.),
October 12, 2020, Volume:
59, Issue:
42
Journal Article
Peer reviewed
Open access
Valuing diversity leads to scientific excellence, the progress of science and most importantly, it is simply the right thing to do. We can value diversity not only in words, but also in actions.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
A diverse view of science to catalyse change Urbina-Blanco, César A; Jilani, Safia Z; Speight, Isaiah R ...
Chemical science (Cambridge),
09/2020, Volume:
11, Issue:
34
Journal Article
Peer reviewed
Open access
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We can value diversity not only in words, but also in actions.
...Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We must value diversity not only in words, but also in actions.
Full text
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IJS, KILJ, NUK, UL, UM, UPUK
Valuing diversity leads to scientific excellence, the progress of science and, most importantly, it is simply the right thing to do. We can value diversity not only in words, but also in actions.
Full text
Available for:
IJS, KILJ, NUK, UL, UM, UPUK
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