A random matrix definition of the boson peak

The density of vibrational states for glasses and jammed solids exhibits universal features, including an excess of modes above the Debye prediction known as the boson peak located at a frequency $\omega^*$ . We show that the eigenvector statistics for boson peak modes are universal, and develop a new definition of the boson peak based on this universality that displays the previously observed characteristic scaling $\omega^*\sim p^{-1/2}$ . We identify a large new class of random matrices that obey a generalized global tranlational invariance constraint and demonstrate that members of this class also have a boson peak with precisely the same universal eigenvector statistics. We denote this class as boson peak random matrices, and conjecture it comprises a new universality class. We characterize the eigenvector statistics as a function of coordination number, and find that one member of this new class reproduces the scaling of $\omega^{*}$ with coordination number that is observed near the jamming transition.Comment: 6 pages, 4 figures, Supplementary Figures available at https://mmanning.expressions.syr.edu/epl2015

Exploring the remuneration ‘black box’: establishing an organizational learning insight into changing remuneration committee ‘social worlds’

Current executive compensation research posits a need to extend analysis beyond principalagent theory in order to explore the complex social influences and processes implicated in Remuneration Committee (RemCo) decision-making (e.g. Bender, 2007; Kakabadse et al, 2006; Main et al., 2007), particularly given the current uproar surrounding reported levels and structuring of executive remuneration. We respond to this international need by highlighting how innovative organizational learning theorizing can be integrated into further investigations of the remuneration ‘Black Box’, in order to focus attention upon the nuances of what and how organizational learning takes place in the remuneration process. Additionally, we note the importance of investigating the main actors and particularly their performance of complex roles within their rapidly evolving ‘social worlds’. By exploring the organizational learning phenomena implicated in executive remuneration, we argue that practitioners, regulatory bodies etc. can appreciate further the implications of their respective decision-making

Phenomenological Implications of Supersymmetric Family Non-universal U(1)-prime Models

We construct a class of anomaly-free supersymmetric U(1)' models that are characterized by family non-universal U(1)' charges motivated from E_6 embeddings. The family non-universality arises from an interchange of the standard roles of the two SU(5) 5* representations within the 27 of E_6 for the third generation. We analyze U(1)' and electroweak symmetry breaking and present the particle mass spectrum. The models, which include additional Higgs multiplets and exotic quarks at the TeV scale, result in specific patterns of flavor-changing neutral currents in the b to s transitions that can accommodate the presently observed deviations inthis sector from the SM predictions.Comment: 25 pages, 3 figure

Pancake bouncing on superhydrophobic surfaces

Engineering surfaces that promote rapid drop detachment is of importance to a wide range of applications including anti-icing, dropwise condensation6, and self-cleaning. Here we show how superhydrophobic surfaces patterned with lattices of submillimetre-scale posts decorated with nano-textures can generate a counter-intuitive bouncing regime: drops spread on impact and then leave the surface in a flattened, pancake shape without retracting. This allows for a four-fold reduction in contact time compared to conventional complete rebound. We demonstrate that the pancake bouncing results from the rectification of capillary energy stored in the penetrated liquid into upward motion adequate to lift the drop. Moreover, the timescales for lateral drop spreading over the surface and for vertical motion must be comparable. In particular, by designing surfaces with tapered micro/nanotextures which behave as harmonic springs, the timescales become independent of the impact velocity, allowing the occurrence of pancake bouncing and rapid drop detachment over a wide range of impact velocities.Comment: 11 pages, 4 figures, 31 references, + 5 pages of supplementary informatio

A statistical framework for recovering intensity mapping autocorrelations from crosscorrelations

Intensity mapping experiments will soon have surveyed large swathes of the sky, providing information about the underlying matter distribution of the early universe. The resulting maps can be used to recover statistical information, such as the power spectrum, about the measured spectral lines (for example, HI, [CII], and [OIII]). However precise power spectrum measurements, such as the 21 cm autocorrelation, continue to be challenged by the presence of bright foregrounds and non-trivial systematics. By crosscorrelating different data sets, it may be possible to mitigate the effects of both foreground uncertainty and uncorrelated instrumental systematics. Beyond their own merit, crosscorrelations could also be used to recover autocorrelation information. Such a technique was proposed in Beane et al. (2019) for recovering the 21 cm power spectrum. Generalizing their result, we develop a statistical framework for combining multiple crosscorrelation signals in order to infer information about the corresponding autocorrelations. We do this first within the Least Squares Estimator (LSE) framework, and show how one can derive their estimator, along with several alternative estimators. We also investigate the posterior distribution of recovered autocorrelation and associated model parameters. We find that for certain noise regimes and cosmological signal modeling assumptions this procedure is effective at recovering autospectra from a set of crosscorrelations. Finally, we showcase our framework in the context of several near-future line intensity mapping experiments.Comment: 18 pages, 13 figures, to be submitted to MNRA

Identification of a 24-kDa Polypeptide Processed from the Coronavirus Infectious Bronchitis Virus 1a Polyprotein by the 3C-like Proteinase and Determination of Its Cleavage Sites

AbstractWe report here the identification of a 24-kDa polypeptide in IBV-infected Vero cells by immunoprecipitation with a region-specific antiserum raised in rabbits against the IBV sequence encoded between nucleotides 10928 and 11493. Coexpression, deletion, and mutagenesis studies have demonstrated that this protein is encoded by ORF 1a from nucleotide 10915 to 11544 and is released from the 1a polyprotein by the 3C-like proteinase-mediated proteolysis. A previously predicted Q-S (Q3462S3463) dipeptide bond encoded by the IBV sequence from nucleotide 10912 to 10917 is identified as the N-terminal cleavage site, and a Q-N (Q3672N3673) dipeptide bond encoded by the IBV sequence between nucleotides 11542 and 11547 is identified as the C-terminal cleavage site of the 24-kDa polypeptide

Dimensional Changes of Upper Airway after Rapid Maxillary Expansion: A Prospective Cone-beam Computed Tomography Study

Introduction: The aim of this prospective study was to use cone-beam computed tomography to assess the dimensional changes of the upper airway in orthodontic patients with maxillary constriction treated by rapid maxillary expansion. Methods: Fourteen orthodontic patients (mean age, 12.9 years; range, 9.7-16 years) were recruited. The patients with posterior crossbite and constricted maxilla were treated with rapid maxillary expansion as the initial part of their comprehensive orthodontic treatments. Before and after rapid maxillary expansion conebeam computed tomography scans were taken to measure the retropalatal and retroglossal airway changes in terms of volume, and sagittal and cross-sectional areas. The transverse expansions by rapid maxillary expansion were assessed between the midlingual alveolar bone plates at the maxillary first molar and first premolar levels. The measurements of the before and after rapid maxillary expansion scans were compared by using paired t tests with the Bonferroni adjustment for multiple comparisons. Results: After rapid maxillary expansion, significant and equal amounts of 4.8 mm of expansion were observed at the first molar (P 5 0.0000) and the first premolar (P 5 0.0000) levels. The width increase at the first premolar level (20.0%) was significantly greater than that at the first molar level (15.0%) (P 5 0.035). As the primary outcome variable, the cross-sectional airway measured from the posterior nasal spine to basion level was the only parameter showing a significant increase of 99.4 mm2 (59.6%) after rapid maxillary expansion (P 5 0.0004). Conclusions: These results confirm the findings of previous studies of the effect of rapid maxillary expansion on the maxilla. Additionally, we found that only the cross-sectional area of the upper airway at the posterior nasal spine to basion level significantly gains a moderate increase after rapid maxillary expansion