Amplification of High Harmonics Using Weak Perturbative High Frequency Radiation

The mechanism underlying the substantial amplification of the high-order harmonics q \pm 2K (K integer) upon the addition of a weak seed XUV field of harmonic frequency q\omega to a strong IR field of frequency \omega is analyzed in the framework of the quantum-mechanical Floquet formalism and the semiclassical re-collision model. According to the Floquet analysis, the high-frequency field induces transitions between several Floquet states and leads to the appearance of new dipole cross terms. The semiclassical re-collision model suggests that the origin of the enhancement lies in the time-dependent modulation of the ground electronic state induced by the XUV field.Comment: 8 pages, 2 figure

Lattice Model of Sweeping Interface for Drying Process in Water-Granule Mixture

Based on the invasion percolation model, a lattice model for the sweeping interface dynamics is constructed to describe the pattern forming process by a sweeping interface upon drying the water-granule mixture. The model is shown to produce labyrinthine patterns similar to those found in the experiment[Yamazaki and Mizuguchi, J. Phys. Soc. Jpn. \textbf{69} (2000) 2387]. Upon changing the initial granular density, resulting patterns undergo the percolation transition, but estimated critical exponents are different from those of the conventional percolation. Loopless structure of clusters in the patterns produced by the sweeping dynamics seems to influence the nature of the transition.Comment: 6 pages, 7 figure

A model for alignment between microscopic rods and vorticity

Numerical simulations show that microscopic rod-like bodies suspended in a turbulent flow tend to align with the vorticity vector, rather than with the dominant eignevector of the strain-rate tensor. This paper investigates an analytically solvable limit of a model for alignment in a random velocity field with isotropic statistics. The vorticity varies very slowly and the isotropic random flow is equivalent to a pure strain with statistics which are axisymmetric about the direction of the vorticity. We analyse the alignment in a weakly fluctuating uniaxial strain field, as a function of the product of the strain relaxation time $\tau_{\rm s}$ and the angular velocity $\omega$ about the vorticity axis. We find that when $\omega\tau_{\rm s}\gg 1$, the rods are predominantly either perpendicular or parallel to the vorticity

The Future Of The Valuation Profession

The aim of this research was to explore the future of the property profession generally and the role of the Valuer in particular, and how the profession could maintain and increase relevance and currency, and set an agenda to support employers in attracting and retaining a more diverse talent pool to run the businesses of the future. This report presents the findings of the research project that investigates extant literature on the issues and challenges faced by the current valuation profession

Sarcoptic mange of pigs

THIS parasitic disease appears to be much more common than is usually recognised; for, while severe cases with chronic skin lesions are readily seen, light infestations, especially on coloured pigs often go unnoticed. When it is realised that even lightly infested pigs require twice as much feed to make one pound gain in live weight as do uninfested pigs, then early recognition and treatment of the disease becomes an obvious economical necessity

Meeting Changing Industry Expectations From Australian Property Valuation Graduates

The valuation profession faces significant challenges as more valuation processes become automated, and the role of the valuer becomes more one of data handling than an economic analyst. To respond to industry needs, the role of the valuer must change. It follows that there is a need for universities to re-evaluate their existing property curricula, modifying content where necessary, to prepare their graduates better for a changing workforce. Employing a series of focus group discussions with valuation practitioners, this study examined specific industry expectations and provides recommendations to strategically align Australian property curricula with industry expectations in order to maintain the relevance of property education. The study identified personal, technical and business-related skills that are essential for graduates to possess. The roles of the professional bodies, industry/employers and educators to meet the changing demand on the profession are identified. Changes are required to degree programme content in respect of digital technologies and statistical skills. Whilst the universities offer a curriculum that adheres to the accreditation requirements of the professional bodies, there is also a need to incorporate specialised knowledge with set pathways. The need for students to have practical experience is apparent and undertaking placements with assessment that could be credited as part of the degree is recommended. The study highlights the need for a careful analysis of student learning experience to ensure that graduate skills meet the industry expectations, and that graduates themselves are able to adapt to future changes

The future of the Australian valuation profession: New knowledge, emerging trends and practices

© 2018, Emerald Publishing Limited. Purpose: Valuers face significant challenges as processes become automated and the role evolves to data handling and processing. To survive and thrive, valuers must respond to a changing market. The purpose of this paper is to examine the issues, threats and challenges facing the Australian profession, though the issues are global. Design/methodology/approach: This qualitative research sought a deeper understanding of the threats, challenges and new areas of practice that Australian valuers were experiencing. A focus group approach was designed to collect data from practitioners in Sydney and Melbourne. The research aimed to identify new knowledge and skills for the future and emerging trends and practices. Findings: The key issues, threats and challenges faced included increasing use of automated valuation models for low-risk residential valuations, valuers being unable to protect themselves against the banks, loss of control of the data and valuations. In total, 12 knowledge domains and skills required in the future were established and ten emerging trends and practices were identified. Research limitations/implications: The key limitations were that participants were from Melbourne and Sydney in Australia only and the focus is NSW and Victoria centric, although many participants have international work experience. There was an under representation of rural valuers, of small valuation firms, of young, recently joined or qualified valuers and females. Practical implications: The findings inform a manifesto for the future which sets out the practical implications for valuers and the professional body. This action plan sets the new knowledge domains, practices and trends that can be adopted by the profession and its members. Originality/value: This is the original research and highlights some real threats, issues and challenges facing the Australian valuers. It complements work undertaken by legal and accounting professional bodies, which sense change affecting their membership and services. A manifesto for action has been outlined to address the changes that are coming and those already here

The Gender Pay Gap in the British cohort studies, past, present and future

Heather Joshi’s presentation to the UCL Institute of Clinical Trials and Methodology, 7th June 2021

Crystallization and preliminary crystallographic analysis of the DNA gyrase B protein from B-stearothermophilus

DNA gyrase B (GyrB) from B. stearothermophilus has been crystallized in the presence of the non-hydrolyzable ATP analogue, 5'-adenylpl-beta-gamma-imidodiphosphate (ADPNP), by the dialysis method. A complete native data set to 3.7 Angstrom has been collected from crystals which belonged to the cubic space group I23 with unit-cell dimension a = 250.6 Angstrom. Self-rotation function analysis indicates the position of a molecular twofold axis. Low-resolution data sets of a thimerosal and a selenomethionine derivative have also been analysed. The heavy-atom positions are consistent with one dimer in the asymmetric unit

Effects of Electron Correlations on Hofstadter Spectrum

By allowing interactions between electrons, a new Harper's equation is derived to examine the effects of electron correlations on the Hofstadter energy spectra. It is shown that the structure of the Hofstadter butterfly ofr the system of correlated electrons is modified only in the band gaps and the band widths, but not in the characteristics of self-similarity and the Cantor set.Comment: 13 pages, 5 Postscript figure