CP-violating transport theory for electroweak baryogenesis with thermal corrections

We derive CP-violating transport equations for fermions for electroweak baryogenesis from the CTP-formalism including thermal corrections at the one-loop level. We consider both the VEV-insertion approximation (VIA) and the semiclassical (SC) formalism. We show that the VIA-method is based on an assumption that leads to an ill-defined source term containing a pinch singularity, whose regularisation by thermal effects leads to ambiguities including spurious ultraviolet and infrared divergences. We then carefully review the derivation of the semiclassical formalism and extend it to include thermal corrections. We present the semiclassical Boltzmann equations for thermal WKB-quasiparticles with source terms up to the second order in gradients that contain both dispersive and finite width corrections. We also show that the SC-method reproduces the current divergence equations and that a correct implementation of the Fick's law captures the semiclassical source term even with conserved total current ∂μ j μ = 0. Our results show that the VIA-source term is not just ambiguous, but that it does not exist. Finally, we show that the collisional source terms reported earlier in the semiclassical literature are also spurious, and vanish in a consistent calculation.

Wave–Current Interactions at Meso- and Submesoscales: Insights from Idealized Numerical Simulations

Surface gravity waves play a major role in the exchange of momentum, heat, energy, and gases between the ocean and the atmosphere. The interaction between currents and waves can lead to variations in the wave direction, frequency, and amplitude. In the present work, we use an ensemble of synthetic currents to force the wave model WAVEWATCH III and assess the relative impact of current divergence and vorticity in modifying several properties of the waves, including direction, period, directional spreading, and significant wave height Hs. We find that the spatial variability of Hs is highly sensitive to the nature of the underlying current and that refraction is the main mechanism leading to gradients of Hs. The results obtained using synthetic currents were used to interpret the response of surface waves to realistic currents by running an additional set of simulations using the llc4320 MITgcm output in the California Current region. Our findings suggest that wave parameters could be used to detect and characterize strong gradients in the velocity field, which is particularly relevant for the Surface Water and Ocean Topography (SWOT) satellite as well as several proposed satellite missions.

SAR Imaging Features of Shallow Water Bathymetry

Purpose. The aim of the article is to study manifestations of the underwater topography features in the northern part of the White Sea in the images made by the spaceborn synthetic aperture radars (SAR) Sentinel-1A, Sentinel-1B. Methods and Results. In the SAR images, the bottom features are revealed as bright and dark brightness anomalies. The anomalies were observed at the wind speed ranging from 2.6 to 10.8 m/s, and became reverse (bright anomalies turned dark and vice versa), when a tidal current changed its direction. It is shown that the observed SAR imagery contrasts correlate to divergence of a current formed by interaction of a tidal flow with the bottom topography inhomogeneities. The simulated SAR contrasts agree with the observations, and confirm the relation between the observed SAR contrasts and the current divergence. Together with modeling the SAR contrasts, the contribution of different mechanisms to formation of the observed modulations of the normalized radar cross section was qualitatively estimated. The wave breaking effect was especially accentuated. The method for retrieving the underwater bottom topography based on the relationship between the bottom gradient and the SAR imagery contrasts is proposed. Conclusions. Location of the bottom inhomogeneities in the shallow water region on the whole coincides with that of the tidal current divergence and convergence zones, which are observed as brightness anomalies in the SAR images. Breaking of surface waves is the main contributor to the observed SAR contrasts. The bottom topography reconstructed from the SAR contrasts, and the actual one resulted from the bathymetry maps are in good agreement. Some discrepancies are interpreted as possible changes in depth and shape of the bottom topography features induced by action of strong currents and waves.

International Divergence in Gene Patenting

This review explores the recent divergence in international patent law relating to genes and associated subject matter. This divergence stems primarily from decisions of the highest courts in the United States and Australia on the eligibility of patent claims relating to the BRCA gene sequences. Patent offices, courts, and policy makers have struggled for many years to clearly articulate the bounds of patent claims on isolated and synthetic DNA and related products and processes, including methods for their use in genetic diagnostics. This review provides context to the current divergence by mapping key events in the gene patent journey from the early 1980s onward in five key jurisdictions: the United States, the member states of the European Patent Convention, Australia, Canada, and China. Early approaches to gene patenting had some commonalities across jurisdictions, which makes exploration of the recent divergence all the more interesting.There is insufficient empirical evidence to date to confidently predict the consequences of this recent divergence. However, it could potentially have a significant effect on local industry and on consumer access.

Surface Roughness Changes by Finescale Current Gradients: Properties at Multiple Azimuth View Angles

At times, high-resolution images of sea surface roughness can provide stunning details of submesoscale upper-ocean dynamics. As interpreted, transformations of short-scale wind waves by horizontal current gradients are responsible for those spectacular observations. Those observations could prove particularly useful to validate numerical ocean models that reach increasingly high resolutions. Focusing on surface roughness at optical wavelengths, two steps have recently been performed in that direction. First, it was shown in a previous paper by Rascle et al. that surface roughness variations not only trace surface current divergence but also other characteristics of the current gradient tensor, mainly the strain in the wind direction. The wind direction with respect to the current gradient thus stands out as an important interpretative parameter. The second step is the purpose of the present paper, where the effect of the viewing direction is investigated. To this end, the authors discuss pairs of quasi-simultaneous sun-glitter images, taken from different satellite positions, to provide different viewing configurations, namely, quasi-orthogonal azimuth angles at similar zenith angles. As evidenced, upwind and crosswind viewing observations can be markedly different. As further confirmed with idealized numerical simulations, this anisotropy well traces anisotropic surface current areas, while more isotropic contrasts likely trace areas dominated by surface divergence conditions. These findings suggest the potential to directly separate divergence from other deformations by using high-resolution roughness observations at multiple azimuth view angles.

Debate on Public Audit Oversight enforcement: it is all about procedural justice?

This article provides a reflection of the paper as presented and discussed at the FAR conference of 9 and 10 May 2016 “Public Oversight of audit firms: the slippery slope of enforcing regulation” written by Robert Knechel, Carlin Dowling and Robyn Moroney (hereafter KDM, 2016). KDM describe the perceptions of auditors from the Big 4 audit firms and the regulator1 in Australia regarding the correlation between regulatory enforcement style and its perceived impact on audit quality. We believe the paper is relevant and timely, because it documents well the current divergence of perceptions between auditors and regulators on how to continue their pursuit for higher audit quality. We argue that the paper could be strengthened by offering the authors’ views on what is required from both parties to realign their expectations.

Structure and Rupture in Literary History and Historiography

In rethinking modern Chinese literary history, we may draw on insights from two relatively new approaches in the West: postmodern literary history as represented by the Harvard University Press’s “new history” series, and comparative literary history as realized in two multivolume literary histories on Central-Eastern Europe and Latin America, respectively. It is time to move research forward beyond the current divergence between a persistent lack of interest in Chinese literary history in English scholarship and an inundation of literary histories in Chinese. Recent calls in China for defamilarization and microhistories demonstrate the desire to break away from the orthodox model of comprehensive historiography, and a comparative examination of literary historiography in Chinese will further develop a new structural view of modern Chinese literary history in terms of rupture, diversity, and heterogeneity rather than the previous emphasis on continuity, singularity, and homogeneity.