“The Map-makers’ Colors”: Maps in Twentieth-Century American Poetry in English

This article offers a selection of notable American poems about maps and grapples with their place in a century unique for the number, range, and quality of such poems. Though others preceded her, Elizabeth Bishop takes center-stage for “The Map” (1934; Winslow, 1935, 78–79), which recognizes that poets and cartographers create selective, generalized, and simplified views of the world. As the opening poem of her Pulitzer Prize-winning collection (1955), “The Map” continues to inspire other poets to critique the map’s spatial representation in terms of physical geography and intimacy, time and scale, politics and race, as well as science, art, and exploration. “The Map” was soon followed by two influential but very different map-poems: “Cartography” by Louise Bogan (1938) and “Map of My Country” by John Holmes (1939: Part I). In his subsequent collection Map of My Country (1943: Parts I–XII), Holmes argued that a poem maps a person’s identity better than its graphic cousins do. Yet other poets found inspiration and an analogue of their experience in a particular map, cartographer, or painter of maps. Since the 1960s, visual poets have shaped poems into maps of American locales, thus complementing more “conventional” uses of maps to trigger poetic memoirs of place. The sexual revolution has popularized the body-as-map metaphor prominent in Bogan’s “Cartography.” Since 1980, map-fixated collections have been on the rise, encouraging poets of the twenty-first century to consider what maps say about place, culture, history, ourselves

Business Decisions by the New Board: Behavioral Science and Corporate Law

This Article\u27s thesis is that, by reason of its recently secured independence from management domination, the boards of directors of large American corporations are now in a unique position to make business decisions of the highest quality, and that corporate law should respond to this potential appropriately. On the basis of findings in the behavioral sciences, this Article urges a limited rethinking of the role of the chief executive and the board of directors before the model of directors as monitors of the chief executive\u27s performance is frozen in place. Already armed with information supposedly received as monitors, the independent director group can best employ its limited time by doing what corporate law used to command (and still strongly suggests): making business decisions

The Effect of Insider Trading Rules on the Internal Efficiency of the Large Corporation

Academics have hotly debated these justifications for years, and none of the three has achieved universal acclaim. This Article suggests another perspective: Prohibiting insider trading may enhance business decision-making in large corporations. With the exception of proponents of the Business Property view, analysts have focused on how an insider trading rule affects the national securities markets and traders in those markets. The internal governance of the large corporation is a different matter, one deserving separate consideration

“The Map-makers’ Colors”: Maps in Twentieth-Century American Poetry in English

This article offers a selection of notable American poems about maps and grapples with their place in a century unique for the number, range, and quality of such poems. Though others preceded her, Elizabeth Bishop takes center-stage for “The Map” (1934; Winslow, 1935, 78–79), which recognizes that poets and cartographers create selective, generalized, and simplified views of the world. As the opening poem of her Pulitzer Prize-winning collection (1955), “The Map” continues to inspire other poets to critique the map’s spatial representation in terms of physical geography and intimacy, time and scale, politics and race, as well as science, art, and exploration. “The Map” was soon followed by two influential but very different map-poems: “Cartography” by Louise Bogan (1938) and “Map of My Country” by John Holmes (1939: Part I). In his subsequent collection Map of My Country (1943: Parts I–XII), Holmes argued that a poem maps a person’s identity better than its graphic cousins do. Yet other poets found inspiration and an analogue of their experience in a particular map, cartographer, or painter of maps. Since the 1960s, visual poets have shaped poems into maps of American locales, thus complementing more “conventional” uses of maps to trigger poetic memoirs of place. The sexual revolution has popularized the body-as-map metaphor prominent in Bogan’s “Cartography.” Since 1980, map-fixated collections have been on the rise, encouraging poets of the twenty-first century to consider what maps say about place, culture, history, ourselves

Coulomb interaction effects on the electronic structure of radial polarized excitons in nanorings

The electronic structure of radially polarized excitons in structured nanorings is analyzed, with emphasis in the ground-state properties and their dependence under applied magnetic fields perpendicular to the ring plane. The electron-hole Coulomb attraction has been treated rigorously, through numerical diagonalization of the full exciton Hamiltonian in the non-interacting electron-hole pairs basis. Depending on the relative weight of the kinetic energy and Coulomb contributions, the ground-state of polarized excitons has "extended" or "localized" features. In the first case, corresponding to small rings dominated by the kinetic energy, the ground-state shows Aharonov-Bohm (AB) oscillations due to the individual orbits of the building particles of the exciton. In the localized regime, corresponding to large rings dominated by the Coulomb interaction, the only remaining AB oscillations are due to the magnetic flux trapped between the electron and hole orbits. This dependence of the exciton, a neutral excitation, on the flux difference confirms this feature as a signature of Coulomb dominated polarized excitons. Analytical approximations are provided in both regimens, which accurate reproduce the numerical results.Comment: 9 pages, including 6 figure

Bioinformatic evidence for a widely distributed, ribosomally produced electron carrier precursor, its maturation proteins, and its nicotinoprotein redox partners

<p>Abstract</p> <p>Background</p> <p>Enzymes in the radical SAM (rSAM) domain family serve in a wide variety of biological processes, including RNA modification, enzyme activation, bacteriocin core peptide maturation, and cofactor biosynthesis. Evolutionary pressures and relationships to other cellular constituents impose recognizable grammars on each class of rSAM-containing system, shaping patterns in results obtained through various comparative genomics analyses.</p> <p>Results</p> <p>An uncharacterized gene cluster found in many Actinobacteria and sporadically in Firmicutes, Chloroflexi, Deltaproteobacteria, and one Archaeal plasmid contains a PqqE-like rSAM protein family that includes Rv0693 from <it>Mycobacterium tuberculosis</it>. Members occur clustered with a strikingly well-conserved small polypeptide we designate "mycofactocin," similar in size to bacteriocins and PqqA, precursor of pyrroloquinoline quinone (PQQ). Partial Phylogenetic Profiling (PPP) based on the distribution of these markers identifies the mycofactocin cluster, but also a second tier of high-scoring proteins. This tier, strikingly, is filled with up to thirty-one members per genome from three variant subfamilies that occur, one each, in three unrelated classes of nicotinoproteins. The pattern suggests these variant enzymes require not only NAD(P), but also the novel gene cluster. Further study was conducted using SIMBAL, a PPP-like tool, to search these nicotinoproteins for subsequences best correlated across multiple genomes to the presence of mycofactocin. For both the short chain dehydrogenase/reductase (SDR) and iron-containing dehydrogenase families, aligning SIMBAL's top-scoring sequences to homologous solved crystal structures shows signals centered over NAD(P)-binding sites rather than over substrate-binding or active site residues. Previous studies on some of these proteins have revealed a non-exchangeable NAD cofactor, such that enzymatic activity <it>in vitro </it>requires an artificial electron acceptor such as N,N-dimethyl-4-nitrosoaniline (NDMA) for the enzyme to cycle.</p> <p>Conclusions</p> <p>Taken together, these findings suggest that the mycofactocin precursor is modified by the Rv0693 family rSAM protein and other enzymes in its cluster. It becomes an electron carrier molecule that serves <it>in vivo </it>as NDMA and other artificial electron acceptors do <it>in vitro</it>. Subclasses from three different nicotinoprotein families show "only-if" relationships to mycofactocin because they require its presence. This framework suggests a segregated redox pool in which mycofactocin mediates communication among enzymes with non-exchangeable cofactors.</p

Particle dynamics in sheared granular matter

The particle dynamics and shear forces of granular matter in a Couette geometry are determined experimentally. The normalized tangential velocity $V(y)$ declines strongly with distance $y$ from the moving wall, independent of the shear rate and of the shear dynamics. Local RMS velocity fluctuations $\delta V(y)$ scale with the local velocity gradient to the power $0.4 \pm 0.05$. These results agree with a locally Newtonian, continuum model, where the granular medium is assumed to behave as a liquid with a local temperature $\delta V(y)^2$ and density dependent viscosity

Spherical collapse of supermassive stars: neutrino emission and gamma-ray bursts

We present the results of numerical simulations of the spherically symmetric gravitational collapse of supermassive stars (SMS). The collapse is studied using a general relativistic hydrodynamics code. The coupled system of Einstein and fluid equations is solved employing observer time coordinates, by foliating the spacetime by means of outgoing null hypersurfaces. The code contains an equation of state which includes effects due to radiation, electrons and baryons, and detailed microphysics to account for electron-positron pairs. In addition energy losses by thermal neutrino emission are included. We are able to follow the collapse of SMS from the onset of instability up to the point of black hole formation. Several SMS with masses in the range $5\times 10^5 M_{\odot}- 10^9 M_{\odot}$ are simulated. In all models an apparent horizon forms initially, enclosing the innermost 25% of the stellar mass. From the computed neutrino luminosities, estimates of the energy deposition by $\nu\bar{\nu}$-annihilation are obtained. Only a small fraction of this energy is deposited near the surface of the star, where, as proposed recently by Fuller & Shi (1998), it could cause the ultrarelativistic flow believed to be responsible for $\gamma$-ray bursts. Our simulations show that for collapsing SMS with masses larger than $5\times 10^5 M_{\odot}$ the energy deposition is at least two orders of magnitude too small to explain the energetics of observed long-duration bursts at cosmological redshifts. In addition, in the absence of rotational effects the energy is deposited in a region containing most of the stellar mass. Therefore relativistic ejection of matter is impossible.Comment: 13 pages, 11 figures, submitted to A&