Showing 1631 - 1640 of 5709 Items
Date: 1960-01-01
Creator: Kevin Herbert
Access: Open access
- Bulletin / Bowdoin College ; no. 335
Date: 2015-05-28
Creator: Stephen G. Naculich
Access: Open access
- We show that a wide class of tree-level scattering amplitudes involving scalars, gauge bosons, and gravitons, up to three of which may be massive, can be expressed in terms of a Cachazo-He-Yuan representation as a sum over solutions of the scattering equations. These amplitudes, when expressed in terms of the appropriate kinematic invariants, are independent of the masses and therefore identical to the corresponding massless amplitudes.
Date: 2013-07-01
Creator: E. A.G. Schuur, B. W. Abbott, W. B. Bowden, V. Brovkin, P., Camill, J. G. Canadell, J. P. Chanton, F. S. Chapin, T. R. Christensen, P. Ciais, B. T. Crosby, C. I. Czimczik, G. Grosse, J. Harden, D. J. Hayes, G. Hugelius
Access: Open access
- Approximately 1700 Pg of soil carbon (C) are stored in the northern circumpolar permafrost zone, more than twice as much C than in the atmosphere. The overall amount, rate, and form of C released to the atmosphere in a warmer world will influence the strength of the permafrost C feedback to climate change. We used a survey to quantify variability in the perception of the vulnerability of permafrost C to climate change. Experts were asked to provide quantitative estimates of permafrost change in response to four scenarios of warming. For the highest warming scenario (RCP 8.5), experts hypothesized that C release from permafrost zone soils could be 19-45 Pg C by 2040, 162-288 Pg C by 2100, and 381-616 Pg C by 2300 in CO equivalent using 100-year CH global warming potential (GWP). These values become 50 % larger using 20-year CH GWP, with a third to a half of expected climate forcing coming from CH even though CH was only 2.3 % of the expected C release. Experts projected that two-thirds of this release could be avoided under the lowest warming scenario (RCP 2.6). These results highlight the potential risk from permafrost thaw and serve to frame a hypothesis about the magnitude of this feedback to climate change. However, the level of emissions proposed here are unlikely to overshadow the impact of fossil fuel burning, which will continue to be the main source of C emissions and climate forcing. © 2013 The Author(s). 2 4 4 4 4
Date: 1993-01-01
Creator: A. S. Johnson, K. P. Sebens
Access: Open access
- Per polyp feeding rate was independent of the horizontal planform area of colonies. At the lowest velocities, most particles were captured on the upstream edge or in the middle of colonies, but all positional bias in capture rate disappeared at higher velocities. Particle capture and increasing flow speed were negatively associated. There were small, but measurable, differences in mean tentacle length between corals feeding at different velocities. Velocity-dependent feeding rate at most velocities was thus related to changes in flow rather than to changes in feeding behavior. Experiments in which corals were turned upside down revealed that the increased capture rate for rightside-up corals feeding at low velocity could be almost entirely accounted for by gravitational deposition of particles on the corals' tentacles. The tentacles form a canopy within which water movement was slowed, possibly facilitating gravitational deposition of non-buoyant or sinking food particles. -from Authors
Date: 1976-01-01
Creator: Peter R. Mooz
Access: Open access
- Catalog of an exhibition held at the Bowdoin College Museum of Art, May 28-September 12, 1976.
Date: 2007-01-01
Creator: Laura Fecych Sprague
Access: Open access
- Catalog of an exhibition held at the Bowdoin College Museum of Art Oct. 14, 2007 to August 24, 2008 to celebrate the Walker Art Building's renovation and expansion by architects Machado and Silvetti, Boston.
Date: 2019-11-10
Creator: Paolo Di Vecchia, Andrés Luna, Stephen G. Naculich, Rodolfo Russo, Gabriele, Veneziano, Chris D. White
Access: Open access
- The structure of scattering amplitudes in supergravity theories continues to be of interest. Recently, the amplitude for 2→2 scattering in N=8 supergravity was presented at three-loop order for the first time. The result can be written in terms of an exponentiated one-loop contribution, modulo a remainder function which is free of infrared singularities, but contains leading terms in the high energy Regge limit. We explain the origin of these terms from a well-known, unitarity-restoring exponentiation of the high-energy gravitational S-matrix in impact-parameter space. Furthermore, we predict the existence of similar terms in the remainder function at all higher loop orders. Our results provide a non-trivial cross-check of the recent three-loop calculation, and a necessary consistency constraint for any future calculation at higher loops.
Date: 2009-11-03
Creator: Angus S King
Access: Audio recording permanently restricted
Biographial Note
Angus Stanley King, Jr. was born March 31, 1944, in Virginia. His father, Stanley King, was a lawyer in Alexandria and worked as U.S. commissioner and federal magistrate. Angus was active in the civil rights movement, especially in regard to schooling. He was graduated from Dartmouth in 1966 and received his law degree from the University of Virginia in 1969. He worked as a legislative assistant to Senator William D. Hathaway on education, labor, and transportation policy before entering private law practice in Brunswick, Maine, from 1975 to 1983. He hosted the public broadcasting television program Maine Watch, a public affairs talk show. In 1989, he started Northeast Energy Management to run electrical energy conservation projects throughout Maine. As an Independent, he served as governor of Maine from 1994 to 2002; and at the time of this interview he was a lecturer at Bowdoin College in addition to pursuing business interests.
Summary
Interview includes discussion of: family and educational background; working at Pine Tree Legal in Skowhegan, Maine; King’s parents and their political leanings; King’s recollections of the Civil Rights movement; working for Senator Hathaway; U.S. Senate campaign (1972); Senator Hathaway’s relationship with Senator Muskie; meeting George Mitchell while he was involved in public broadcasting; Mitchell and the first Gulf War; King’s work on energy management; King’s decision to run as an Independent; Maine gubernatorial campaign (1994); and Mitchell’s legacy.