Solar Photocatalysis Using Fixed-Film TiO<Subscript>2</Subscript> for Microcystins from Colonial <Emphasis Type="Italic">Microcystis aeruginosa</Emphasis>     

Ciera M. Kinley  Maas Hendrikse  Alyssa J. Calomeni  Tyler D. Geer  John H. RodgersJr 《Water, air, and soil pollution》2018,229(5):167

Microcystins (MCs) are endotoxins produced by cyanobacteria in freshwaters globally. With known potential for human health risks, rapid and effective treatment methods are needed for MCs. Previous studies have shown photocatalysis can achieve rapid half-lives with UV lamps and slurries of TiO₂. In this experiment, rates and extents of solar photocatalysis of MCs were measured using bench-scale reactors with fixed films of TiO₂ for solutions with a range of cellular:aqueous MC ratios. Since cellular MCs can be removed physically, photocatalysis rates were measured following sand filtration to discern the extent of MC removal post-filtration. Since UV energy drives photocatalysis using TiO₂, rates of removal were calculated as a function of cumulative UV insolation and time. For water containing < 10% aqueous MC, filtration removed 90% of total MC, and the subsequent photocatalysis half-life was 0.37 MJ/m² (or 111 min). For water with ~?50% aqueous MCs, filtration removed 52% of the total MCs, and the average half-life for photocatalysis was 0.38 MJ/m² (or 138 min). For the >?90% aqueous MC treatment, filtration removed 0% MCs, and the photocatalysis half-life for MCs was 0.37 MJ/m² (or 135 min). Previous studies have used clarified waters; however, results from this study are likely representative of scenarios with waters containing confounding water characteristics and use of solar light for UV, as anticipated in developing countries with less advanced water treatment methods. Photocatalysis is a rapid and effective process for decreasing concentrations of MCs and could be useful for mitigating risks from MC exposures in drinking water.  相似文献   

In-season decision support tools for estimating sidedress nitrogen rates for corn in the Mid-Atlantic Coastal Plain     

Bee Khim Chim  Tyler Black  Paul Davis 《Journal of plant nutrition》2017,40(20):2818-2828

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Evaluation of Feral Swine-Specific Feeder Systems     

David B. Long  Tyler A. Campbell  Giovanna Massei 《Herpetological Monographs》2010,32(2):8-13

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Prevalence of select infectious agents in inflammatory aural and nasopharyngeal polyps from client-owned cats     

Tyler C. Klose  Catriona M. MacPhail  Patricia C. Schultheiss  Rod A. Rosychuk  Jennifer R. Hawley  Michael R. Lappin 《Journal of Feline Medicine and Surgery》2010,12(10):769-774

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Influence of Three Aquatic Macrophytes on Mitigation of Nitrogen Species from Agricultural Runoff   总被引：1，自引：0，他引：1  

Heather L. Tyler  Matthew T. Moore  Martin A. Locke 《Water, air, and soil pollution》2012,223(6):3227-3236

Agricultural runoff containing nitrogen fertilizer is a major contributor to eutrophication in aquatic systems. One method of decreasing amounts of nitrogen entering rivers or lakes is the transport of runoff through vegetated drainage ditches. Vegetated drainage ditches can enhance the mitigation of nutrients from runoff; however, the efficiency of nitrogen removal can vary between plant species. The efficiency of three aquatic macrophytes, cutgrass (Leersia oryzoides), cattail (Typha latifolia), and bur-reed (Sparganium americanum), to mitigate dissolved and total nitrogen from water was investigated. Replicate mesocosms of each plant species were exposed to flowing water enriched with ammonium and nitrate for 6?h, allowed to remain stagnant for 42?h, and then flushed with non-enriched water for an additional 6?h to simulate a second storm event. After termination of the final simulated runoff, all vegetated treatments lowered total nitrogen loads exiting mesocosms by greater than 50%, significantly more than unvegetated controls, which only decreased concentrations by 26.9% (p????0.0023). L. oryzoides and T. latifolia were more efficient at lowering dissolved nitrogen, decreasing ammonium by 42?±?9% and 59?±?4% and nitrate by 67?±?6% and 64?±?7%, respectively. All treatments decreased ammonium and nitrate concentrations within mesocosms by more than 86% after 1?week. However, T. latifolia and L. oryzoides absorbed nitrogen more rapidly, lowering concentrations by greater than 98% within 48?h. By determining the nitrogen mitigation efficiency of different vegetative species, plant communities in agricultural drainage ditches can be managed to significantly increase their remediation potential.  相似文献   

TOF-SIMS imaging of adsorbed proteins on topographically complex surfaces with Bi(3) (+) primary ions     

Tyler BJ  Bruening C  Rangaranjan S  Arlinghaus HF 《Biointerphases》2011,6(3):135

Although previous studies have demonstrated that TOF-SIMS is a powerful method for the characterization of adsorbed proteins due to its specificity and surface sensitivity, it was unclear from earlier work whether the differences between proteins observed on uniform flat surfaces were large enough to facilitate clear image contrast between similar proteins in small areas on topographically complex samples that are more typical of biological tissues. The goal of this study was to determine whether Bi(3) (+) could provide sufficiently high sensitivity to provide clear identification of the different proteins in an image. In this study, 10 μm polystyrene microspheres were adsorbed with one of three different proteins, human serum albumin (HSA), bovine serum albumin (BSA), and hemoglobin. Spheres coated with HSA were then mixed with spheres coated with either BSA (a very similar protein) or hemoglobin (a dramatically different protein), and deposited on silicon substrates. Fluorescent labeling was used to verify the SIMS results. With maximum autocorrelation factors (MAF) processing, images showed clear contrast between both the very different proteins (HSA and hemoglobin) and the very similar proteins (HSA and BSA). Similar results were obtained with and without the fluorescent labels. MAF images were calculated using both the full spectrum and only characteristic amino acid fragments. Although better image contrast was obtained using the full spectrum, differences between the spheres were still evident when only the amino acid fragments were included in the analysis, suggesting that we are truly observing differences between the proteins themselves. These results demonstrate that TOF-SIMS, with a Bi(3) (+) primary ion, is a powerful technique for characterizing interfacial proteins not only on large uniform surfaces, but also with high spatial resolution on the topographically complex samples typical in biological analysis.  相似文献   

Efficiency of nitrogen uptake by potatoes   总被引：1，自引：0，他引：1  

K. B. Tyler  F. E. Broadbent  J. C. Bishop 《American Journal of Potato Research》1983,60(4):261-269

White Rose potatoes were fertilized with isotopically labeled ammonium sulfate at rates of 67, 134, 202 and 270 kg N/ha to evaluate N uptake efficiency. All N application increased yields above the control, however the 3 higher N rates produced the same yields statistically. All N rates which maximized yields maintained petiole levels of total N above 600 ppm. Rapid changes in petiole inorganic N occurred during the growing season. Fertilizer derived inorganic N decreased at rates ranging from 67 to 518 ppm/day during the third month after planting. Total inorganic N in petioles during the same period dropped at rates ranging from 500 to 880 ppm/ day. Tubers grown in N-fertilized plots assimilated total N in a nearly linear pattern during the period 82 to 125 days after planting. Uptake of total N ranged from 142 to 233 kg/ha. In assessing N utilization by 3 methods, good agreement was achieved between the isotope and difference method in the first and third (last) samplings, however, agreement was poor between the two in the second sampling. With N rates to 202 kg/ha the uptake efficiency was about 57% but dropped to 39% with application of 270 kg N/ha. When uptake efficiency was measured by dry matter production in relation to units of N fertilizer, the 67 kg N rate was superior to other rates. Inorganic N levels in the surface meter of soil were higher before planting and fertilizer application than after harvest. Following harvest the control plots had more N below 1.5 m than did the N fertilized plots. In control plots, the total inorganic N between 1.5 and 2.5 m depths was equivalent to 170 kg N/ha. Virtually none of the accumulated N below 1 m was due to labeled N applied in the experiment. Using 134 kg N/ha as the optimum rate, tubers removed 178 kg N/ha of which 78 kg was derived from the applied fertilizer. With total N input of 191 kg/ha (57 kg N/ha from irrigation water) the N rate required for maximum yield would pose no risk of nitrate pollution since it represents only 13 kg more than crop removal (191 vs 178 kg N/ha).  相似文献   

Urea nitrogen for potatoes     

K. B. Tyler  O. A. Lorenz  F. H. Takatori  J. C. Bishop 《American Journal of Potato Research》1962,39(3):89-99

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Predicting Areas of 137Cs Loss and Accumulation in Upland Catchments     

Tyler  Andrew N.  Heal  Kate V. 《Water, air, and soil pollution》2000,121(1-4):271-288

Anthropogenic radioisotopes with long physicalhalf-lives derived from atmospheric fallout remain inthe environment for decades after deposition. Process- and field-based studies within uplandcatchments show that radiocaesium is transported insolution as well as in particulate form. Catchmenthydrology is therefore an important control onradiocaesium transport and natural processes of soildevelopment. The topographic index, from thehydrological model TOPMODEL, has been used as a basisfor the development of a simple model for predictingradiocaesium redistribution in temperate uplandcatchments. The model is particularly suited topredicting ¹³⁷Cs redistribution within uplandenvironments as it is based on topography, which isreadily calculated from digital terrain models withingeographical information systems. A conceptual modelof radiocaesium losses on hillslopes and re-depositionon the valley floor was calibrated with atmosphericweapons testing ¹³⁷Cs inventories from soil coredata for the Raithburn catchment, Renfrewshire, U.K. The model fitted the observations well and showed thatin this catchment a topographic index value of about5.0, for 10 m grid cells, forms the threshold between¹³⁷Cs loss and accumulation. The resultsindicated that about 20% of the total atmosphericweapons testing ¹³⁷Cs deposited in the catchmenthad been transported out of the catchment over theca. 30 yr period since deposition.  相似文献   

Granule‐Bound Starch Synthase I (GBSSI) in Quinoa (Chenopodium quinoa Willd.) and Its Relationship to Amylose Content     

N. Lindeboom  P. R. Chang  R. T. Tyler  R. N. Chibbar 《Cereal Chemistry》2005,82(3):246-250

The amylose concentration in starch from 16 quinoa (Chenopodium quinoa Willd.) genotypes grown under identical conditions was 4–20%. Based on the amylose content, a selection of six genotypes was made. Starch granule‐bound proteins were extracted from six genotypes and analyzed using denaturing gel electrophoresis. Two major polypeptides with apparent molecular masses of 56 and 62 kDa were present in all genotypes. Both were identified as granule‐bound starch synthase I (GBSSI) using immunoblot analysis and internal peptide sequencing. The content of the two GBSSI isoforms in starch granules from the six genotypes, as determined by densiometry of the peptide bands, was positively correlated with the concentration of amylose in starch from mature seed. Starch synthase activity in developing seed was positively correlated to starch concentration in seed and amylose concentration in starch during seed development.  相似文献