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1. Organic Semiconductors at the University of Washington: Advancements in Materials Design and Synthesis and toward Industrial Scale Production

   https://doi.org/10.1002/adma.201904239  

   Huang, Yunping; Elder, Delwin_L; Kwiram, Alvin_L; Jenekhe, Samson_A; Jen, Alex_K_Y; Dalton, Larry_R; Luscombe, Christine_K (October 2019, Advanced Materials)

   Abstract Research at the University of Washington regarding organic semiconductors is reviewed, covering four major topics: electro‐optics, organic light emitting diodes, organic field‐effect transistors, and organic solar cells. Underlying principles of materials design are demonstrated along with efforts toward unlocking the full potential of organic semiconductors. Finally, opinions on future research directions are presented, with a focus on commercial competency, environmental sustainability, and scalability of organic‐semiconductor‐based devices. 

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2. Salmon‐derived nutrient and organic matter fluxes from a coastal catchment in southeast Alaska

   https://doi.org/10.1111/fwb.13292  

   Hood, Eran; Fellman, Jason B.; Edwards, Rick T.; D'Amore, David V.; Scott, Durelle (March 2019, Freshwater Biology)

   Abstract Salmon are important vectors for biogeochemical transport across ecosystem boundaries. Here we quantified salmon contributions to annual catchment fluxes of nutrients (N and P) and organic matter (C, N, and P) from a forested catchment in coastal southeast Alaska.Concentrations of ammonium and soluble reactive phosphorus increased by several orders of magnitude during spawning and were significantly correlated with spawning salmon densities. Nitrate concentrations increased modestly during spawning and were not significantly correlated with salmon densities. Salmon had a modest legacy effect on inorganic N and P as evidenced by elevated streamwater concentrations past the end of the spawning period.Dissolved organic carbon concentrations did not respond to the presence of salmon; however, concentrations of dissolved organic nitrogen and phosphorus showed a significant positive relationship to salmon densities. Changes in spectroscopic properties of the bulk streamwater dissolved organic matter pool indicated that streamwater dissolved organic matter became less aromatic and biolabile during spawning.On an annual basis, salmon were the dominant source of streamwater fluxes of inorganic nutrients, accounting for 92%, 65%, and 74% of annual streamwater fluxes of ammonium, nitrate, and soluble reactive phosphorus, respectively. In contrast, fluxes of organic matter were dominated by catchment sources with salmon accounting for <1% of the annual catchment flux of dissolved organic carbon and 12% and 15% of the annual fluxes of dissolved organic nitrogen and phosphorous respectively.These findings indicate that, in small coastal catchments, salmon can be a quantitatively important source of dissolved streamwater nutrients with implications for productivity in downstream estuarine ecosystems. 

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3. Inorganic nitrogen and organic matter jointly regulate ectomycorrhizal fungi‐mediated iron acquisition

   https://doi.org/10.1111/nph.20394  

   Wang, Haihua; Zhang, Kaile; Tappero, Ryan; Victor, Tiffany W; Bhatnagar, Jennifer M; Vilgalys, Rytas; Liao, Hui‐Ling (January 2025, New Phytologist)

   Summary Ectomycorrhizal fungi (EMF) play a crucial role in facilitating plant nutrient uptake from the soil although inorganic nitrogen (N) can potentially diminish this role. However, the effect of inorganic N availability and organic matter on shaping EMF‐mediated plant iron (Fe) uptake remains unclear.To explore this, we performed a microcosm study onPinus taedaroots inoculated withSuillus cothurnatustreated with +/−Fe‐coated sand, +/−organic matter, and a gradient of NH₄NO₃concentrations.Mycorrhiza formation was most favorable under conditions with organic matter, without inorganic N. Synchrotron X‐ray microfluorescence imaging on ectomycorrhizal cross‐sections suggested that the effect of inorganic N on mycorrhizal Fe acquisition largely depended on organic matter supply. With organic matter, mycorrhizal Fe concentration was significantly decreased as inorganic N levels increased. Conversely, an opposite trend was observed when organic matter was absent. Spatial distribution analysis showed that Fe, zinc, calcium, and copper predominantly accumulated in the fungal mantle across all conditions, highlighting the mantle's critical role in nutrient accumulation and regulation of nutrient transfer to internal compartments.Our work illustrated that the liberation of soil mineral Fe and the EMF‐mediated plant Fe acquisition are jointly regulated by inorganic N and organic matter in the soil. 

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4. The unique biogeochemical role of carbonate-associated organic matter in a subtropical seagrass meadow

   https://doi.org/10.1038/s43247-024-01832-7  

   Zeller, Mary A; Van_Dam, Bryce R; Lopes, Christian; McKenna, Amy M; Osburn, Christopher L; Fourqurean, James W; Kominoski, John S; Böttcher, Michael Ernst (December 2024, Communications Earth & Environment)

   Abstract The particulate organic matter buried in carbonate-rich seagrass ecosystems is an important blue carbon reservoir. While carbonate sediments are affected by alkalinity produced or consumed in seagrass-mediated biogeochemical processes, little is known about the corresponding impact on organic matter. A portion of particulate organic matter is carbonate-associated organic matter. Here, we explore its biogeochemistry in a carbonate seagrass meadow in central Florida Bay, USA. We couple inorganic stable isotope analyses (δ³⁴S, δ¹⁸O) with a molecular characterization of dissolved and carbonate associated organic matter (21 tesla Fourier-transform ion cyclotron resonance mass spectrometry). We find that carbonate-associated molecular formulas are highly sulfurized compared to surface water dissolved organic matter, with multiple sulfurization pathways at play. Furthermore, 97% of the formula abundance of surface water dissolved organic matter is shared with carbonate-associated organic matter, indicating connectivity between these two pools. We estimate that 9.2% of the particulate organic matter is carbonate-associated, and readily exchangeable with the broader aquatic system as the sediment dissolves and reprecipitates. 

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5. Spillover effects of organic agriculture on pesticide use on nearby fields

   https://doi.org/10.1126/science.adf2572  

   Larsen, Ashley E; Noack, Frederik; Powers, L Claire (March 2024, Science)

   The environmental impacts of organic agriculture are only partially understood and whether such practices have spillover effects on pests or pest control activity in nearby fields remains unknown. Using about 14,000 field observations per year from 2013 to 2019 in Kern County, California, we postulate that organic crop producers benefit from surrounding organic fields decreasing overall pesticide use and, specifically, pesticides targeting insect pests. Conventional fields, by contrast, tend to increase pesticide use as the area of surrounding organic production increases. Our simulation suggests that spatially clustering organic cropland can entirely mitigate spillover effects that lead to an increase in net pesticide use. 

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