2,377 research outputs found
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Prosthetizing the Soul: Reading, Seeing, and Feeling in Seventeenth-Century Devotion
My dissertation proposes a new context for reading early modern devotional writing’s rich engagement with the language of the body in its focus on the relationship between gendered representations of devotional desire and spiritual ability in the religious poetry of seventeenth-century England. By tracing how somatic speech and bodily conditions are portrayed in the devotional poetry of John Milton, Richard Crashaw, Thomas Traherne, and An Collins, this project examines how these writers fashion spiritual states through the language of a sometime sorrowful and sometime ecstatic, but always desiring body. My project reveals how early modern authors manipulate or respond to gendered and bodily hierarchies to craft liturgically rich devotional scenes that exceed and overwhelm sensations of spiritual lack written on and within the bodies of the devotional figures presented therein. Through my focus on the body of the text and also the ways in which bodies are represented within devotional texts, I posit a new way of looking at early modern devotional writing: as prosthetics. The term prosthesis is most often associated with a medical appendage supplementing a bodily lack, but my project takes seriously the animating capacity of language as I demonstrate the ways in which early modern devotional writing exhibits a “prosthetic impulse” that blurs mind-body divides via the amplified register of highly affective somatic speech. Far from mere metaphor, this dissertation shows how the prosthetized devotional text materializes and makes known the spiritual abilities of authors who actively frame divine desire around bodies in opposition to the normative cisgendered and ableist body so widely celebrated in religious discourses of the period. Reading devotional texts as prosthetics that supplement the spiritual lack experienced by early modern believers struggling to articulate their relationship with the divine reveals the problematic interplay between self and society in its blurring of the boundaries between immaterial soul, the material body, and the literal pages before us. My project thus demonstrates how the prosthetized text actively reframes dualist constructions of the body and soul, men and women, and also spiritual health and ability
Carbon cycling in mesohaline Chesapeake Bay sediments 2: Kinetics of particulate and dissolved organic carbon turnover
Temporal and depth variations in benthic carbon metabolism rates were examined in relation to particulate organic carbon (POC) deposition rates and particulate and dissolved organic carbon degradation kinetics in two sediments from the mesohaline region of Chesapeake Bay. The depth distribution of a single pool of metabolizable POC (MPOC) in mid-Bay sediments was estimated by curve-fitting of dry weight POC profiles (“1-G” approach). Estimated MPOC pools accounted for 3–4% of total POC content in the upper 10 cm of sediment. First-order MPOC decay constants of ≈10 yr−1 during the warm season were estimated from the ratio of MPOC pool size to weighted-average MPOC deposition rate derived from mid-water column sediment trap deployments. These results indicated that the MPOC pool defined by the 1-G approach corresponded to the most readily degradable component of coastal marine phytoplankton detritus. Transient-state kinetic models of MPOC turnover, based on observed MPOC deposition rates and temperature-dependent mineralization, predicted MPOC accumulation in sediments during the spring followed by depletion during the summer. The models also predicted an early summer maximum in MPOC mineralization rate associated with the degradation of MPOC accumulated during the spring, in agreement with the seasonal pattern of sulfate reduction rates in mid-Bay sediments. Model results suggested that MPOC deposition during the summer is important in maintaining high rates of benthic carbon metabolism throughout the warm season. Steady-state and transient-state models of depth-dependent POC degradation suggested that particle mixing influences the depth distribution of MPOC concentration and turnover rate within the upper 4–6 cm of mid-Bay sediments. However, because of the rapid rate of MPOC decay, random particle mixing is unlikely to transport significant quantities of MPOC below 4–6 cm. A steady-state diagenetic model was used to test the hypothesis that downward diffusion of acetate produced by anaerobic decomposition of MPOC in the upper 4–6 cm fuels sulfate reduction deeper in the sediment. The results suggest that because of the very rapid turnover of acetate pools (≥ 2 hr−1), acetate diffusion does not influence the depth distribution of carbon metabolism in the sediment. Therefore, sulfate reduction occurring at depths below 4–6 cm must be fueled by decomposition of some portion of the large pool of relatively refractory sediment POC. Degradation of this material is likely responsible for ≈1/3 of total warm season benthic carbon metabolism
Microbial Reduction of Crystalline Iron(III) Oxides: Influence of Oxide Surface Area and Potential for Cell Growth
Quantitative aspects of microbial crystalline iron- (III) oxide reduction were examined using a dissimilatory iron(III) oxide-reducing bacterium (Shewanella alga strain BrY). The initial rate and long-term extent of reduction of a range of synthetic iron(III) oxides were linearly correlated with oxide surface area. Oxide reduction rates reached an asymptote at cell concentrations in excess of ≈1 x 109/m2 of oxide surface. Experiments with microbially reduced goethite that had been washed with pH 5 sodium acetate to remove adsorbed Fe(II) suggested that formation of a Fe(II) surface phase (adsorbed or precipitated) limited the extent of iron(III) oxide reduction. These results demonstrated explicitly that the rate and extent of microbial iron (III) oxide reduction is controlled by the surface area and site concentration of the solid phase. Strain BrY grew in media with synthetic goethite as the sole electron acceptor. The quantity of cells produced per micromole of goethite reduced (2.5 X 106) was comparable to that determined previously for growth of BrY and other dissimilatory Fe (III)- reducing bacteria coupled to amorphous iron(III) oxide reduction. BrY reduced a substantial fraction (8-18%) of the crystalline iron(III) oxide content of a variety of soil and subsurface materials, and several cultures containing these materials were transferred repeatedly with continued active Fe(III) reduction. These findings indicate that Fe(III)- reducing bacteria may be able to survive and produce significant quantities of Fe(II) in anaerobic soil and subsurface environments where crystalline iron(III) oxides (e.g., goethite) are the dominant forms of Fe- (III) available for microbial reduction. Results suggest that the potential for cell growth and Fe (II) generation will be determined by the iron (III) oxide surface site concentration in the soil or sediment matrix
Microbial Reduction of Crystalline Iron(III) Oxides: Influence of Oxide Surface Area and Potential for Cell Growth
Quantitative aspects of microbial crystalline iron- (III) oxide reduction were examined using a dissimilatory iron(III) oxide-reducing bacterium (Shewanella alga strain BrY). The initial rate and long-term extent of reduction of a range of synthetic iron(III) oxides were linearly correlated with oxide surface area. Oxide reduction rates reached an asymptote at cell concentrations in excess of ≈1 x 109/m2 of oxide surface. Experiments with microbially reduced goethite that had been washed with pH 5 sodium acetate to remove adsorbed Fe(II) suggested that formation of a Fe(II) surface phase (adsorbed or precipitated) limited the extent of iron(III) oxide reduction. These results demonstrated explicitly that the rate and extent of microbial iron (III) oxide reduction is controlled by the surface area and site concentration of the solid phase. Strain BrY grew in media with synthetic goethite as the sole electron acceptor. The quantity of cells produced per micromole of goethite reduced (2.5 X 106) was comparable to that determined previously for growth of BrY and other dissimilatory Fe (III)- reducing bacteria coupled to amorphous iron(III) oxide reduction. BrY reduced a substantial fraction (8-18%) of the crystalline iron(III) oxide content of a variety of soil and subsurface materials, and several cultures containing these materials were transferred repeatedly with continued active Fe(III) reduction. These findings indicate that Fe(III)- reducing bacteria may be able to survive and produce significant quantities of Fe(II) in anaerobic soil and subsurface environments where crystalline iron(III) oxides (e.g., goethite) are the dominant forms of Fe- (III) available for microbial reduction. Results suggest that the potential for cell growth and Fe (II) generation will be determined by the iron (III) oxide surface site concentration in the soil or sediment matrix
I\u27m In Heaven When I\u27m In Your Arms
https://digitalcommons.library.umaine.edu/mmb-vp/5925/thumbnail.jp
Influence of Aqueous and Solid-Phase Fe(II) Complexants on Microbial Reduction of Crystalline Iron(III) Oxides
The influence of aqueous (NTA and EDTA) and solidphase (aluminum oxide, layer silicates) Fe(II) complexants on the long-term microbial reduction of synthetic goethite by Shewanella alga strain BrY was studied. NTA enhanced goethite reduction by promoting aqueous Fe(II) accumulation, in direct proportion to its concentration in culture medium (0.01-5 mM). In contrast, EDTA failed to stimulate goethite reduction at concentrations e1 mM, and 5 mM EDTA enhanced the final extent of reduction by only 25% in relation to nonchelator controls. The minor effect of EDTA compared to NTA, despite the greater stability of the Fe(II)- EDTA complex, likely resulted from sorption of Fe(II)- EDTA complexes to goethite. Equilibrium Fe(II) speciation calculations showed that Fe(II)aq should increase with NTA at the expense of the solid-phase Fe(II) species, whereas the opposite trend was true for EDTA due to Fe(II)EDTA adsorption. The presence of aluminum oxide and layer silicates led to a variable but significant (1.5 to \u3e 3-fold) increase in the extent of goethite reduction. Speciation of Fe(II) verified the binding of Fe(II) by these solid-phase materials. Our results support the hypothesis that iron(III) oxide reduction may be enhanced by aqueous or solid-phase compounds which prevent or delay Fe(II) sorption to oxide and FeRB cell surfaces
Influence of Aqueous and Solid-Phase Fe(II) Complexants on Microbial Reduction of Crystalline Iron(III) Oxides
The influence of aqueous (NTA and EDTA) and solidphase (aluminum oxide, layer silicates) Fe(II) complexants on the long-term microbial reduction of synthetic goethite by Shewanella alga strain BrY was studied. NTA enhanced goethite reduction by promoting aqueous Fe(II) accumulation, in direct proportion to its concentration in culture medium (0.01-5 mM). In contrast, EDTA failed to stimulate goethite reduction at concentrations e1 mM, and 5 mM EDTA enhanced the final extent of reduction by only 25% in relation to nonchelator controls. The minor effect of EDTA compared to NTA, despite the greater stability of the Fe(II)- EDTA complex, likely resulted from sorption of Fe(II)- EDTA complexes to goethite. Equilibrium Fe(II) speciation calculations showed that Fe(II)aq should increase with NTA at the expense of the solid-phase Fe(II) species, whereas the opposite trend was true for EDTA due to Fe(II)EDTA adsorption. The presence of aluminum oxide and layer silicates led to a variable but significant (1.5 to \u3e 3-fold) increase in the extent of goethite reduction. Speciation of Fe(II) verified the binding of Fe(II) by these solid-phase materials. Our results support the hypothesis that iron(III) oxide reduction may be enhanced by aqueous or solid-phase compounds which prevent or delay Fe(II) sorption to oxide and FeRB cell surfaces
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In Situ Immobilization of Uranium in Structured Porous Media via Biomineralization at the Fraction/Matrix Interface
The major objectives of the University of Alabama component of this project are to (1) characterize the chemical composition (mainly iron and uranium abundance and redox speciation) of FRC Area 2 sediments; (2) assess the potential for stimulation of microbial Fe(III) and U(VI) reduction in slurries of Area 2 sediments; and (3) analyze the response of microbial community structure to biostimulation, specifically with regard to the abundance and diversity of dissimilatory metal-reducing bacterial (DMRB) populations. As an inclusive working hypothesis, we anticipate that it will be possible to stimulate microbial metal reduction in Area 2 sediment depth strata containing substantial quantities of Fe(III) oxides and U(VI), and that a major enrichment in known DMRB (e.g. Geobacteraceae and related organisms) will take place in response to biostimulation. Information on rates of microbial metabolism, patterns of Fe/U biotransformation, and microbial community response obtained in the slurry experiments will be used to constrain preliminary numerical simulations of the field-scale biostimulation experiment, and to provide molecular (e.g. 16S rRNA/rDNA) targets for assessing the response of DMRB activity to in situ biostimulation. Our progress to date on the above objectives is summarized
Influence of Complex Exciton-Phonon Coupling on Optical Absorption and Energy Transfer of Quantum Aggregates
We present a theory that efficiently describes the quantum dynamics of an
electronic excitation that is coupled to a continuous, highly structured phonon
environment. Based on a stochastic approach to non-Markovian open quantum
systems, we develop a dynamical framework that allows us to handle realistic
systems where a fully quantum treatment is desired yet the usual approximation
schemes fail. The capability of the method is demonstrated by calculating
spectra and energy transfer dynamics of mesoscopic molecular aggregates,
elucidating the transition from fully coherent to incoherent transfer
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