Showing 461 - 470 of 5689 Items
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Prints, Drawings, Paintings: Thomas Cornell
- Catalog of an exhibition held at the Bowdoin College Museum of Art, 1964.
1964
Whole genome sequence of the heterozygous clinical isolate Candida krusei 81-B-5
- Candida krusei is a diploid, heterozygous yeast that is an opportunistic fungal pathogen in immunocompromised patients. This species also is utilized for fermenting cocoa beans during chocolate production. One major concern in the clinical setting is the innate resistance of this species to the most commonly used antifungal drug fluconazole. Here, we report a high-quality genome sequence and assembly for the first clinical isolate of C. krusei, strain 81-B-5, into 11 scaffolds generated with PacBio sequencing technology. Gene annotation and comparative analysis revealed a unique profile of transporters that could play a role in drug resistance or adaptation to different environments. In addition, we show that, while 82% of the genome is highly heterozygous, a 2.0 Mb region of the largest scaffold has undergone loss of heterozygosity. This genome will serve as a reference for further genetic studies of this pathogen.
2017
Higher rank lamplighter groups are graph automatic
- We show that the higher rank lamplighter groups, or Diestel–Leader groups Γd(q) for d≥3, are graph automatic. This introduces a new family of graph automatic groups which are not automatic.
2018
Evolution in Candida albicans populations during a single passage through a mouse host
- The mechanisms and rates by which genotypic and phenotypic variation is generated in opportunistic, eukaryotic pathogens during growth in hosts are not well understood. We evaluated genomewide genetic and phenotypic evolution in Candida albicans, an opportunistic fungal pathogen of humans, during passage through a mouse host (in vivo) and during propagation in liquid culture (in vitro). We found slower population growth and higher rates of chromosome-level genetic variation in populations passaged in vivo relative to those grown in vitro. Interestingly, the distribution of long-range loss of heterozygosity (LOH) and chromosome rearrangement events across the genome differed for the two growth environments, while rates of short-range LOH were comparable for in vivo and in vitro populations. Further, for the in vivo populations, there was a positive correlation of cells demonstrating genetic alterations and variation in colony growth and morphology. For in vitro populations, no variation in growth phenotypes was detected. Together, our results demonstrate that passage through a living host leads to slower growth and higher rates of genomic and phenotypic variation compared to in vitro populations. Results suggest that the dynamics of population growth and genomewide rearrangement contribute to the maintenance of a commensal and opportunistic life history of C. albicans. Copyright © 2009 by the Genetics Society of America.
2009
Knuth relations for the hyperoctahedral groups
- C. Bonnafé, M. Geck, L. Iancu, and T. Lam have conjectured a description of Kazhdan-Lusztig cells in unequal parameter Hecke algebras of type B which is based on domino tableaux of arbitrary rank. In the integer case, this generalizes the work of D. Garfinkle. We adapt her methods and construct a family of operators which generate the equivalence classes on pairs of arbitrary rank domino tableaux described in the above conjecture. © 2008 Springer Science+Business Media, LLC.
2009
Littoral Abstractions: Drawings by Emily Nelligan
- Includes an essay by the curator Allison Ferris.
2000
Continuity Trumps Change: The First Year of Trump's Administrative Presidency
- From campaign rhetoric to tweets, President Trump has positioned himself as disrupter in chief, often pointing to administrative action as the avenue by which he is leaving a lasting mark. However, research on the administrative presidency begins with the premise that all presidents face incentives to use administrative tools to gain substantive or political traction. If, as this article suggests, Trump's institutional standing differs little from his recent predecessors, then how much of the Trump presidency represents a change from past norms and practices' How much represents continuity, or the perennial dynamics of a far-from-omnipotent executive in an ongoing world of separate institutions sharing powers (Neustadt 1990, 29)' To answer this, we tracked presidential directives and regulatory policy during Trump's first year in office. We found evidence of continuity, indicating that in its use of administrative tactics to shape policy, the Trump White House largely falls in line with recent presidencies.
2019
Multistable solitons in higher-dimensional cubic-quintic nonlinear Schrödinger lattices
- We study the existence, stability, and mobility of fundamental discrete solitons in two- and three-dimensional nonlinear Schrödinger lattices with a combination of cubic self-focusing and quintic self-defocusing onsite nonlinearities. Several species of stationary solutions are constructed, and bifurcations linking their families are investigated using parameter continuation starting from the anti-continuum limit, and also with the help of a variational approximation. In particular, a species of hybrid solitons, intermediate between the site- and bond-centered types of the localized states (with no counterpart in the 1D model), is analyzed in 2D and 3D lattices. We also discuss the mobility of multi-dimensional discrete solitons that can be set in motion by lending them kinetic energy exceeding the appropriately defined Peierls-Nabarro barrier; however, they eventually come to a halt, due to radiation loss. © 2008 Elsevier B.V. All rights reserved.
2009
All-loop infrared-divergent behavior of most-subleading-color gauge-theory amplitudes
- The infrared singularities of gravitational amplitudes are one-loop exact, in that higher-loop divergences are characterized by the exponential of the one-loop divergence. We show that the contributions to SU(N) gauge-theory amplitudes that are mostsubleading in the 1/N expansion are also one-loop exact, provided that the dipole conjecture holds. Possible corrections to the dipole conjecture, beginning at three loops, could violate one-loop-exactness, though would still maintain the absence of collinear divergences. We also demonstrate a relation between L-loop four-point N = 8 supergravity and mostsubleading-color N = 4 SYM amplitudes that holds for the two leading IR divergences, (Formula presented.) and (Formula presented.), but breaks down at (Formula presented.).
2013