Shakespearean allusion and the detective fiction of Georgette Heyer

This essay argues that Shakespearean allusion is a recurrent and important factor in the detective novels of Georgette Heyer. Though the master text for Heyer is Hamlet, a variety of Shakespeare plays are referred to, and mention of them functions in multiple ways. Quotations from Shakespeare reveal truths about the characters and comment on their situations and personalities. They also afford points of entry for people previously unacquainted to talk to each other, and finally they have effects in terms of genre, since their presence can, with equal facility, tend towards comic relief (in line with a tradition in Golden Age crime fiction of using Macbeth in particular to comic effect) or work to add gravitas and resonance. The use of Shakespearean allusion is thus central to Heyer’s technique. This article is published as part of a collection to commemorate the 400th anniversary of William Shakespeare’s death

CO Abundance Variations in the Orion Molecular Cloud

Infrared stellar photometry from 2MASS and spectral line imaging observations of 12CO and 13CO J = 1-0 line emission from the FCRAO 14m telescope are analysed to assess the variation of the CO abundance with physical conditions throughout the Orion A and Orion B molecular clouds. Three distinct Av regimes are identified in which the ratio between the 13CO column density and visual extinction changes corresponding to the photon dominated envelope, the strongly self-shielded interior, and the cold, dense volumes of the clouds. Within the strongly self-shielded interior of the Orion A cloud, the 13CO abundance varies by 100% with a peak value located near regions of enhanced star formation activity. The effect of CO depletion onto the ice mantles of dust grains is limited to regions with AV > 10 mag and gas temperatures less than 20 K as predicted by chemical models that consider thermal-evaporation to desorb molecules from grain surfaces. Values of the molecular mass of each cloud are independently derived from the distributions of Av and 13CO column densities with a constant 13CO-to-H2 abundance over various extinction ranges. Within the strongly self-shielded interior of the cloud (Av > 3 mag), 13CO provides a reliable tracer of H2 mass with the exception of the cold, dense volumes where depletion is important. However, owing to its reduced abundance, 13CO does not trace the H2 mass that resides in the extended cloud envelope, which comprises 40-50% of the molecular mass of each cloud. The implied CO luminosity to mass ratios, M/L_{CO}, are 3.2 and 2.9 for Orion A and Orion B respectively, which are comparable to the value (2.9), derived from gamma-ray observations of the Orion region. Our results emphasize the need to consider local conditions when applying CO observations to derive H2 column densities.Comment: Accepted for publication in MNRAS. 21 pages, 14 figure

Reconstitution of recombination-associated DNA synthesis with human proteins.

The repair of DNA breaks by homologous recombination is a high-fidelity process, necessary for the maintenance of genome integrity. Thus, DNA synthesis associated with recombinational repair must be largely error-free. In this report, we show that human DNA polymerase delta (δ) is capable of robust DNA synthesis at RAD51-mediated recombination intermediates dependent on the processivity clamp PCNA. Translesion synthesis polymerase eta (η) also extends these substrates, albeit far less processively. The single-stranded DNA binding protein RPA facilitates recombination-mediated DNA synthesis by increasing the efficiency of primer utilization, preventing polymerase stalling at specific sequence contexts, and overcoming polymerase stalling caused by topological constraint allowing the transition to a migrating D-loop. Our results support a model whereby the high-fidelity replicative DNA polymerase δ performs recombination-associated DNA synthesis, with translesion synthesis polymerases providing a supportive role as in normal replication

Symmetry, incommensurate magnetism and ferroelectricity: the case of the rare-earth manganites RMnO3

The complete irreducible co-representations of the paramagnetic space group provide a simple and direct path to explore the symmetry restrictions of magnetically driven ferroelectricity. The method consists of a straightforward generalization of the method commonly used in the case of displacive modulated systems and allows us to determine, in a simple manner, the full magnetic symmetry of a given phase originated from a given magnetic order parameter. The potential ferroic and magneto-electric properties of that phase can then be established and the exact Landau free energy expansions can be derived from general symmetry considerations. In this work, this method is applied to the case of the orthorhombic rare-earth manganites RMnO3. This example will allow us to stress some specific points, such as the differences between commensurate or incommensurate magnetic phases regarding the ferroic and magnetoelectric properties, the possible stabilization of ferroelectricity by a single irreducible order parameter or the possible onset of a polarization oriented parallel to the magnetic modulation. The specific example of TbMnO3 will be considered in more detail, in order to characterize the role played by the magneto-electric effect in the mechanism for the polarization rotation induced by an external magnetic field.Comment: Conference: Aperiodic`0

Striations in the Taurus molecular cloud: Kelvin-Helmholtz instability or MHD waves?

The origin of striations aligned along the local magnetic field direction in the translucent envelope of the Taurus molecular cloud is examined with new observations of 12CO and 13CO J=2-1 emission obtained with the 10~m submillimeter telescope of the Arizona Radio Observatory. These data identify a periodic pattern of excess blue and redshifted emission that is responsible for the striations. For both 12CO and 13CO, spatial variations of the J=2-1 to J=1-0 line ratio are small and are not spatially correlated with the striation locations. A medium comprised of unresolved CO emitting substructures (cells) with a beam area filling factor less than unity at any velocity is required to explain the average line ratios and brightness temperatures. We propose that the striations result from the modulation of velocities and the beam filling factor of the cells as a result of either the Kelvin-Helmholtz instability or magnetosonic waves propagating through the envelope of the Taurus molecular cloud. Both processes are likely common features in molecular clouds that are sub-Alfvenic and may explain low column density, cirrus-like features similarly aligned with the magnetic field observed throughout the interstellar medium in far-infrared surveys of dust emission.Comment: 11 pages, 4 figures. Accepted for publication in MNRA

WFPC2 Observations of NGC 454: an Interacting Pair of Galaxies

We present WFPC2 images in the F450W, F606W and F814W filters of the interacting pair of galaxies NGC 454. Our data indicate that the system is in the early stages of interaction. A population of young star-clusters has formed around the late component, and substantial amounts of gas have sunk into the center of the earlier component, where it has not yet produced significant visible star formation or nuclear activity. We have photometric evidence that the star-clusters have strong line emission, which indicate the presence of a substantial component of hot, massive stars which formed less than 5-10 Myrs ago.Comment: 14 pages, 4 figures, Latex (AAS macros), ApJL in pres

Unusually Luminous Giant Molecular Clouds in the Outer Disk of M33

We use high spatial resolution (~7pc) CARMA observations to derive detailed properties for 8 giant molecular clouds (GMCs) at a galactocentric radius corresponding to approximately two CO scale lengths, or ~0.5 optical radii (r25), in the Local Group spiral galaxy M33. At this radius, molecular gas fraction, dust-to-gas ratio and metallicity are much lower than in the inner part of M33 or in a typical spiral galaxy. This allows us to probe the impact of environment on GMC properties by comparing our measurements to previous data from the inner disk of M33, the Milky Way and other nearby galaxies. The outer disk clouds roughly fall on the size-linewidth relation defined by extragalactic GMCs, but are slightly displaced from the luminosity-virial mass relation in the sense of having high CO luminosity compared to the inferred virial mass. This implies a different CO-to-H2 conversion factor, which is on average a factor of two lower than the inner disk and the extragalactic average. We attribute this to significantly higher measured brightness temperatures of the outer disk clouds compared to the ancillary sample of GMCs, which is likely an effect of enhanced radiation levels due to massive star formation in the vicinity of our target field. Apart from brightness temperature, the properties we determine for the outer disk GMCs in M33 do not differ significantly from those of our comparison sample. In particular, the combined sample of inner and outer disk M33 clouds covers roughly the same range in size, linewidth, virial mass and CO luminosity than the sample of Milky Way GMCs. When compared to the inner disk clouds in M33, however, we find even the brightest outer disk clouds to be smaller than most of their inner disk counterparts. This may be due to incomplete sampling or a potentially steeper cloud mass function at larger radii.Comment: Accepted for Publication in ApJ; 7 pages, 4 figure

Resistivity and Hall effect of LiFeAs: Evidence for electron-electron scattering

LiFeAs is unique among the broad family of FeAs-based superconductors, because it is superconducting with a rather large $T_c\simeq 18$ K under ambient conditions although it is a stoichiometric compound. We studied the electrical transport on a high-quality single crystal. The resistivity shows quadratic temperature dependence at low temperature giving evidence for strong electron-electron scattering and a tendency towards saturation around room temperature. The Hall constant is negative and changes with temperature, what most probably arises from a van Hove singularity close to the Fermi energy in one of the hole-like bands. Using band structure calculations based on angular resolved photoemission spectra we are able to reproduce all the basic features of both the resistivity as well as the Hall effect data.Comment: 6 pages, 3 figures included; V2 has been considerably revised and contain a more detailed analysis of the Hall effect dat