Showing 3651 - 3660 of 5708 Items
Mythologies modernes : à la recherche des écrivaines dans la capitale littéraire de Paris de l’entre-deux-guerres This record is embargoed.
- Embargo End Date: 2029-05-16
Date: 2024-01-01
Creator: Stephanie Ruth McCurrach
Access: Embargoed
Reactions Responsible for Aging in Wood-Based Pyrolysis Oil: Synthesis and Characterization of a Coniferyl Alcohol Dimer
Date: 2021-01-01
Creator: Alejandro Garcia
Access: Open access
- The negative environmental impact and the diminishing supply of fossil fuels demand a renewable alternative. Pyrolysis oils produced from the decomposition of biomass, like wood, are a potential fuel substitute for energy production and a feedstock alternative for manufacturing value-added chemicals. The possibilities offered by pyrolysis oils are offset by oil instability. The oils contain reactive compounds, such as small aldehydes, conjugated aromatics, and acids that over time react and produce higher molecular mass products. This instability manifests as an increase in viscosity by a process referred to as aging. One chemical component, coniferyl alcohol, is proposed to react with formaldehyde under the acidic oil conditions to produce a dimer. In our lab, researchers have detected the coniferyl alcohol dimer in authentic oil samples and have simulated the reaction under conditions that removes the complexity of the pyrolysis oil matrix. This study focused on the synthesis, isolation, and characterization of the dimer structure by employing NMR analysis. GC/MS analysis of a successful synthesis of the dimer showed multiple dimers were produced, but there was one principal product. The NMR analysis of this dimer was used to elucidate the geometry, providing evidence that the product has E stereochemistry for the double bond and trans stereochemistry in the acetal ring. Confirmation of the principal structure provides support for the dimerization mechanism and will allow for future research to address instability of pyrolysis oils.
Neuropeptide modulation of pattern-generating systems in crustaceans: comparative studies and approaches
Date: 2016-12-01
Creator: Patsy S. Dickinson, Xuan Qu, Meredith E. Stanhope
Access: Open access
- Central pattern generators are subject to modulation by peptides, allowing for flexibility in patterned output. Current techniques used to characterize peptides include mass spectrometry and transcriptomics. In recent years, hundreds of neuropeptides have been sequenced from crustaceans; mass spectrometry has been used to identify peptides and to determine their levels and locations, setting the stage for comparative studies investigating the physiological roles of peptides. Such studies suggest that there is some evolutionary conservation of function, but also divergence of function even within a species. With current baseline data, it should be possible to begin using comparative approaches to ask fundamental questions about why peptides are encoded the way that they are and how this affects nervous system function.
Measurement of the inclusive B* cross section above the (4S)
Date: 1991-01-01
Creator: D. S. Akerib, B. Barish, D. F. Cowen, G. Eigen, R., Stroynowski, J. Urheim, A. J. Weinstein, R. Morrison, D. Schmidt, M. Procario, D. R. Johnson, K. Lingel, P. Rankin, J. G. Smith, J. Alexander, C. Bebek, K. Berkelman, D. Besson, T. E. Browder, D. G. Cassel, E. Cheu, D. M. Coffman, P. S. Drell, R. Ehrlich, R. S. Galik, M. Garcia-Sciveres, B. Geiser, B. Gittelman, S. W. Gray, D. L. Hartill, B. K. Heltsley
Access: Open access
- Using the CLEO II detector at the Cornell Electron Storage Ring, we have determined the inclusive B* cross section above the (4S) resonance in the energy range from 10.61 to 10.70 GeV. We also report a new measurement of the energy of the B*B transition photon of 46.20.30.8 MeV. © 1991 The American Physical Society.
Bowdoin College Catalogue (1958-1959)
Date: 1959-01-01
Access: Open access
- Bowdoin College Bulletin no. 330
Bowdoin College Catalogue (1967-1968)
Date: 1968-01-01
Access: Open access
- Bowdoin College Bulletin no. 366
The Modulatory Role of the Hyperpolarization-Activated Inward Current and Adenosine A1 - Dopamine D1 Receptor Heteromers on Spinal Locomotor Activity Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Andrew Moore
Access: Access restricted to the Bowdoin Community
The contributions of motor neuronal and muscle modulation to behavioral flexibility in the stomatogastric system
Date: 1995-12-01
Creator: Patsy S. Dickinson
Access: Open access
- The stomatogastric nervous system of crustaceans, which controls the four parts ofthe foregut, is subject to modulation at all levels, sensory, central and motor. Modulation of the central pattern generators, which are themselves made up largely of motor neurons, providesfor increased behavioral flexibility in a variety of ways. First, each of the pattern generators can be reconfigured to give multiple outputs. Second, the "boundaries" of the different pattern generators are in fact somewhat fluid, so that the neuronal composition of the pattern generators can be altered. For example, neurons can switch from one pattern generator toanother, or two or more pattern generators can fuse to generate an entirely new pattern and thereby produce a new behavior. The mechanisms responsible for many of these modulations include alterations of both intrinsic properties and synaptic interactions between neurons. In addition, the alteration of membrane properties contributes more directly to the behavioral output by changing action potential frequency. Finally, the muscles of the stomatogastric system can themselves be modulated, with the cpvl muscle, for example, becoming an endogenous oscillator in the presence of either dopamine or the peptide FMRFamide. © 1995 by the American Society of Zoologists.
Trumpet slices of the Schwarzschild-Tangherlini spacetime
Date: 2010-12-01
Creator: Kenneth A. Dennison, John P. Wendell, Thomas W. Baumgarte, J. David Brown
Access: Open access
- We study families of time-independent maximal and 1+log foliations of the Schwarzschild-Tangherlini spacetime, the spherically symmetric vacuum black hole solution in D spacetime dimensions, for D≥4. We identify special members of these families for which the spatial slices display a trumpet geometry. Using a generalization of the 1+log slicing condition that is parameterized by a constant n we recover the results of Nakao, Abe, Yoshino, and Shibata in the limit of maximal slicing. We also construct a numerical code that evolves the Baumgarte-Shapiro-Shibata-Nakamura equations for D=5 in spherical symmetry using moving-puncture coordinates and demonstrate that these simulations settle down to the trumpet solutions. © 2010 The American Physical Society.