A5036726237- Marine Biology and Ecology Research
- Marine and coastal plant biology
- Oxidative Organic Chemistry Reactions
- Coastal wetland ecosystem dynamics
- Radical Photochemical Reactions
- Geology and Paleoclimatology Research
- Methane Hydrates and Related Phenomena
- Marine and coastal ecosystems
- Marine and fisheries research
- Catalytic C–H Functionalization Methods
- Peatlands and Wetlands Ecology
- Isotope Analysis in Ecology
- Atmospheric and Environmental Gas Dynamics
- Ocean Acidification Effects and Responses
- Coral and Marine Ecosystems Studies
- Groundwater and Isotope Geochemistry
- Marine Bivalve and Aquaculture Studies
- Asymmetric Hydrogenation and Catalysis
- Archaeology and Historical Studies
- Dental Implant Techniques and Outcomes
- Power Systems and Technologies
- Soil and Water Nutrient Dynamics
- Dental Radiography and Imaging
- Dental materials and restorations
- Hydrocarbon exploration and reservoir analysis
Leibniz Institute for Baltic Sea Research
2020-2024
ORCID
2021
Florida International University
2020
University of North Carolina at Chapel Hill
2014-2016
Urbana University
2010
University of Illinois Urbana-Champaign
2010
University of Zurich
1994
A direct, catalytic hydrodecarboxylation of primary, secondary, and tertiary carboxylic acids is reported. The system consists a Fukuzumi acridinium photooxidant with phenyldisulfide acting as redox-active cocatalyst. Substoichiometric quantities Hünig's base are used to reveal the carboxylate. Use trifluoroethanol solvent allowed for significant improvements in substrate compatibilities, method reported not limited bearing α heteroatoms or phenyl substitution. This has been applied direct...
A direct catalytic synthesis of γ-butyrolactones from simple alkene and unsaturated acid starting materials is reported. The system consists the Fukuzumi acridinium photooxidant substoichiometric quantities a redox-active cocatalyst. Oxidizable alkenes such as styrenes trisubstituted aliphatic are cyclized with acids via polar radical crossover cycloaddition (PRCC) reactions. This method has been applied to diastereoselective total methylenolactocin protolichesterinic acid.
Rigorous carbon accounting shows that calcification-driven CO 2 emissions can exceed seagrass “Blue Carbon” storage.
Bhutan is a landlocked country straddling the Himalayan Arc, with elevations ranging from approximately 170 to 7,600 m a.s.l. Despite these high elevations, large portions of do not show glacial overprint and are thought have remained relatively stable in terms erosion during recent geological history. This unique geomorphological setting characterized by quasi-stationary fluvial system low hillslope erosion, as evidenced well-preserved sedimentary records deeply weathered rock horizons...
Terrestrial surface waters and submarine ground water discharge (SGD) act as a source of dissolved substances for coastal systems. Solute fluxes SGD depend on the composition water-solid-microbe interactions close to sediment-water interface. Thus, this study aims characterize evaluate hydrogeochemical gradients developing in fresh-salt mixing zone Wismar Bay (WB), southern Baltic Sea, Germany. Sampling campaigns covering WB, at beach WB shoreline, terrestrial near well sediments pore were...
Eutrophication in lakes and reservoirs has prompted interest using sediment capping technology to reduce the contribution internal nutrient loading. One such is Phoslock®, a lanthanum-embedded clay, which can bind phosphate at surface limit its diffusion into water column. However, well-oxygenated lakes, naturally occurring iron by similar mechanism. We sought test efficacy of Phoslock® limiting (PO43−) fluxes relative untreated iron-rich lake under conditions bottom-water oxia anoxia...
Abstract Long-term “blue carbon” burial in seagrass meadows is complicated by other carbon and alkalinity exchanges that shape net sequestration. We measured a suite of such processes, including denitrification, sulfur, inorganic cycling, assessed their impact on air-water dioxide exchange typical meadow underlain carbonate sediments. Contrary to the prevailing concept acting as sinks, eddy covariance measurements reveal this ecosystem consistent source atmosphere, at an average rate 610 ±...
Trawl-fishing is broadly considered to be one of the most destructive anthropogenic activities toward benthic ecosystems. In this study, we examine effects bottom-contact fishing by otter trawls on geochemistry and macrofauna in sandy silt sediment an area Baltic Sea where clear spatial patterns trawling activity were previously identified acoustic mapping. We calibrated early diagenetic model biogeochemical data from various coring locations. Fitting measured mercury profiles allowed for...
Room temperature, copper-catalyzed amination of amido-bromo-1,8-naphthyridines is reported. Use Cu(2)O and aqueous ammonia at ambient temperature affords products in 10-87% yield. Bromonaphthyridines are prepared 15-65% yield via treatment amidonaphthyridinones with phosphorus tribromide. This methodology provides an alternative route to functional, nonsymmetric 2,7-diamido-1,8-naphthyridines.
OPINION article Front. Mar. Sci., 01 November 2021Sec. Marine Biogeochemistry https://doi.org/10.3389/fmars.2021.729992
Seagrasses can enhance carbonate sediment dissolution on diel timescales through oxidation of the rhizosphere and production acidic exudates dissolved organic matter (DOM). Carbonates also associate with DOM either from biogenesis or later adsorption. However, impact mineral release carbonate-associated surface water quantity quality is unclear. We analyzed sub-daily changes in EEMS-PARAFAC components (excitation-emission matrices parallel factor analysis), fluorescence, absorbance...
Abstract. Benthic alkalinity production is often suggested as a major driver of net carbon sequestration in continental shelf ecosystems. However, information on and direct measurements benthic fluxes are limited especially challenging when biological dynamic physical forcing causes surficial sediments to be vigorously irrigated. To address this shortcoming, we quantified sediment–water exchange using suite complementary methods, including (1) 224Ra budgeting, (2) incubations with Br−...
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 seagrass-mediated biogeochemical processes, little known about the corresponding impact on matter. A portion of carbonate-associated Here, we explore its biogeochemistry a meadow central Florida Bay, USA. We couple inorganic stable isotope analyses (δ 34 S, δ 18 O) with molecular characterization...
Carbonate-associated organic matter (CAOM) is the associated with carbonate minerals, and a survey of carbonate-rich surface sediments suggests that it incorporated at consistent amount scaling internal area grains. As sediment sensitive to changes in saturation state due benthic biogeochemical processing, we predicted CAOM could exhibit interesting cycling, based on its potential bridge particulate dissolved pools matter. Here, report study seagrass meadow central Florida Bay, USA. We...
<p>The research project MGF-Ostsee deals with the consequences of exclusion mobile bottom-contact fishing in southern Baltic Sea, specifically to assess its effects on biogeochemistry surface sediments and across benthic-pelagic food chain. In Summer 2021, an in-situ monitored experiment was conducted at a coastal site in region Warnemünde/Rostock investigate short-term impacts bottom trawling. Herein, we present first results how this anthropogenic...
<p>Seagrasses are often considered important players in the global carbon cycle, due to their role sequestering and protecting sedimentary organic matter as “Blue Carbon”.  However, shallow calcifying systems ultimate of seagrass meadows a sink or source atmospheric CO<sub>2</sub> is complicated by carbonate precipitation dissolution processes, which produce consume CO<sub>2</sub>,...
Abstract The direct photolytic decarboxylation of a variety carboxylic acids is presented.
Preview this conference paper: Biogeochemistry of Carbonate – Associated Organic Matter: a Story in 3 Parts, Page 1 < Previous page | Next > /docserver/preview/fulltext/2214-4609/2023/imog-2023/283-1.gif
Abstract The resulting aminonaphthyridines can smoothly be converted into synthetically useful nonsymmetric 2,7‐diamidonaphthyridines.
&lt;p&gt;Florida Bay is subtropical embayment characterized by dense Thalassia testudinum seagrass meadows, the prevalence of carbonate-rich sediments, and relatively long residence times (~1 yr). Florida meadows store appreciable quantities allochthonous autochthonous organic matter (OM) as so-called &amp;#8216;blue carbon&amp;#8217;, fate which therefore tied to that carbonate minerals it bound to. &amp;#160;Dissolved carbon (DOC) concentrations are also high (~7-12...