Reliable and robust molecular sexing of the hen harrier (Circus cyaneus) using PCR-RFLP of the CHD1 gene

The hen harrier (Circus cyaneus) is a bird of prey that is persecuted in the United Kingdom, and there is a need for a DNA-based individual identification and sexing system for the use in forensic investigations. This study reports a new set of PCR primers for the chromo-helicase-DNA-binding protein 1 gene, which allows sexing using PCR-RFLP. Instead of exonic primers that amplify across a large intron, this set consists of a primer within the intron, enabling reduction in amplicon sizes from 356 to 212 bp and 565 to 219 bp in W and Z chromosomes. DNA degradation and dilution experiments demonstrate that this set is significantly more robust than one that amplifies across the intron, and sequencing of the intronic primer-binding region across several individuals shows that it is highly conserved. While our objective is to incorporate this primer set into an STR-based individualization kit, it may in the meantime prove useful in forensic or conservation studies

European Option Pricing with Liquidity Shocks

We study the valuation and hedging problem of European options in a market subject to liquidity shocks. Working within a Markovian regime-switching setting, we model illiquidity as the inability to trade. To isolate the impact of such liquidity constraints, we focus on the case where the market is completely static in the illiquid regime. We then consider derivative pricing using either equivalent martingale measures or exponential indifference mechanisms. Our main results concern the analysis of the semi-linear coupled HJB equation satisfied by the indifference price, as well as its asymptotics when the probability of a liquidity shock is small. We then present several numerical studies of the liquidity risk premia obtained in our models leading to practical guidelines on how to adjust for liquidity risk in option valuation and hedging.Comment: 25 pages, 6 figure

NALNET book system: Cost benefit study

The goals of the NASA's library network system, NALNET, the functions of the current book system, the products and services of a book system required by NASA Center libraries, and the characteristics of a system that would best supply those products and services were assessed. Emphasis was placed on determining the most cost effective means of meeting NASA's requirements for an automated book system. Various operating modes were examined including the current STIMS file, the PUBFILE, developing software improvements for products as appropriate to the Center needs, and obtaining cataloging and products from the bibliographic utilities including at least OCLC, RLIN, BNA, and STIF. It is recommended that NALNET operate under the STIMS file mode and obtain cataloging and products from the bibliographic utilities. The recommendations are based on the premise that given the current state of the art in library automation it is not cost effective for NASA to maintain a full range of cataloging services on its own system. The bibliographic utilities can support higher quality systems with a greater range of services at a lower total cost

Predicting the whispering gallery mode spectra of microresonators

The whispering gallery modes (WGMs) of optical resonators have prompted intensive research efforts due to their usefulness in the field of biological sensing, and their employment in nonlinear optics. While much information is available in the literature on numerical modeling of WGMs in microspheres, it remains a challenging task to be able to predict the emitted spectra of spherical microresonators. Here, we establish a customizable Finite- Difference Time-Domain (FDTD)-based approach to investigate the WGM spectrum of microspheres. The simulations are carried out in the vicinity of a dipole source rather than a typical plane-wave beam excitation, thus providing an effective analogue of the fluorescent dye or nanoparticle coatings used in experiment. The analysis of a single dipole source at different positions on the surface or inside a microsphere, serves to assess the relative efficiency of nearby radiating TE and TM modes, characterizing the profile of the spectrum. By varying the number, positions and alignments of the dipole sources, different excitation scenarios can be compared to analytic models, and to experimental results. The energy flux is collected via a nearby disk-shaped region. The resultant spectral profile shows a dependence on the configuration of the dipole sources. The power outcoupling can then be optimized for specific modes and wavelength regions. The development of such a computational tool can aid the preparation of optical sensors prior to fabrication, by preselecting desired the optical properties of the resonator.Comment: Approved version for SPIE Photonics West, LASE, Laser Resonators, Microresonators and Beam Control XV

Method for predicting whispering gallery mode spectra of spherical microresonators

A full three-dimensional Finite-Difference Time-Domain (FDTD)-based toolkit is developed to simulate the whispering gallery modes of a microsphere in the vicinity of a dipole source. This provides a guide for experiments that rely on efficient coupling to the modes of microspheres. The resultant spectra are compared to those of analytic models used in the field. In contrast to the analytic models, the FDTD method is able to collect flux from a variety of possible collection regions, such as a disk-shaped region. The customizability of the technique allows one to consider a variety of mode excitation scenarios, which are particularly useful for investigating novel properties of optical resonators, and are valuable in assessing the viability of a resonator for biosensing.Comment: Published 10 Apr 2015 in Opt. Express Vol. 23, Issue 8, pp. 9924-9937; The FDTD toolkit supercomputer scripts are hosted at: http://sourceforge.net/projects/npps/files/FDTD_WGM_Simulator

Extracting Classical Correlations from a Bipartite Quantum System

In this paper we discuss the problem of splitting the total correlations for a bipartite quantum state described by the Von Neumann mutual information into classical and quantum parts. We propose a measure of the classical correlations as the difference between the Von Neumann mutual information and the relative entropy of entanglement. We compare this measure with different measures proposed in the literature.Comment: 5 pages, 1 figur

Solitary waves and yrast states in Bose-Einstein condensed gases of atoms

Considering a Bose-Einstein condensed gas confined in one dimension with periodic boundary conditions, we demonstrate that, very generally, solitary-wave and rotational excitations coincide. This exact equivalence allows us to establish connections between a number of effects that are present in these two problems, many of which have been studied using the mean-field approximation.Comment: Revised version, where the generality of our arguments is presented more clearl

Foundations of Quantum Discord

This paper summarizes the basics of the notion of quantum discord and how it relates to other types of correlations in quantum physics. We take the fundamental information theoretic approach and illustrate our exposition with a number of simple examples.Comment: 3 pages, special issue edited by Diogo de Oliveira Soares Pinto et a

Coupled Cluster Channels in the Homogeneous Electron Gas

We discuss diagrammatic modifications to the coupled cluster doubles (CCD) equations, wherein different groups of terms out of rings, ladders, crossed-rings and mosaics can be removed to form approximations to the coupled cluster method, of interest due to their similarity with various types of random phase approximations. The finite uniform electron gas is benchmarked for 14- and 54-electron systems at the complete basis set limit over a wide density range and performance of different flavours of CCD are determined. These results confirm that rings generally overcorrelate and ladders generally undercorrelate; mosaics-only CCD yields a result surprisingly close to CCD. We use a recently developed numerical analysis [J. J. Shepherd and A. Gr\"uneis, Phys. Rev. Lett. 110, 226401 (2013)] to study the behaviours of these methods in the thermodynamic limit. We determine that the mosaics, on forming the Brueckner Hamltonian, open a gap in the effective one-particle eigenvalues at the Fermi energy. Numerical evidence is presented which shows that methods based on this renormalisation have convergent energies in the thermodynamic limit including mosaic-only CCD, which is just a renormalised MP2. All other methods including only a single channel, namely ladder-only CCD, ring-only CCD and crossed-ring-only CCD, appear to yield divergent energies; incorporation of mosaic terms prevents this from happening.Comment: 9 pages, 4 figures, 1 table. Comments welcome: [email protected]

Incentivising Specific Combinations of Subjects – Does It Make Any Difference to University Access?

A major part of the 2010–15 UK government's education reforms in England was a focus on the curriculum that pupils study from ages 14–16. Most high profile was the introduction of the English Baccalaureate (EBacc) performance measure for schools, incentivising study of “subjects the Russell Group identifies as key for university study” (Gibb, 2011). However, there does not appear to be good quantitative evidence about the importance of studying such a set of subjects, per se. This paper sets out to analyse this question, considering whether otherwise similar young people who study specific sets of subjects (full set for EBacc-eligibility, two or more sciences, foreign languages, applied subjects) to age 16 have different probabilities of entering university, and specifically a high-status university. It compares results from regression modelling and propensity score matching, taking advantage of rich survey data from a recent cohort of young people in England. We find that conditional differences in university entry attributable to subject choice are, at most, small