All-optical non-demolition measurement of single-hole spin in a quantum-dot molecule

We propose an all-optical scheme to perform a non-demolition measurement of a single hole spin localized in a quantum-dot molecule. The latter is embedded in a microcavity and driven by two lasers. This allows to induce Raman transitions which entangle the spin state with the polarization of the emitted photons. We find that the measurement can be completed with high fidelity on a timescale of 100 ps, shorter than the typical T2. Furthermore, we show that the scheme can be used to induce and observe spin oscillations without the need of time-dependent magnetic fields

Evaluation of enzyme immunoassays in the diagnosis of camel (Camelus dromedarius) trypanosomiasis:a preliminary investigation

Three enzyme immunoassays were used for the serodiagnosis of Trypanosoma evansi in camels in the Sudan in order to evaluate their ability to discriminate between infected and non-infected animals. Two assays were used for the detection of trypanosomal antibodies, one using specific anti-camel IgG conjugate and another using a non-specific Protein A conjugate. The third assay detected the presence of trypanosomal antigens using anti-T. evansi antibodies in a double antibody sandwich assay. Inspection of the frequency distribution of assay results suggested that the ELISA for circulating trypanosomal antibodies using specific antisera and the ELISA for circulating antigens can distinguish between non-infected camels and infected camels exhibiting patent infections or not. The ELISA using Protein A conjugate to bind non-specifically to camel immunoglobulin did not appear to discriminate between infected and non-infected animals

Interaction of Agulhas filaments with mesoscale turbulence: a case study

The inter-ocean leakage of heat and salt from the South Indian Ocean to the South Atlantic has important consequences for the global thermohaline circulation and in particular for the strength of overturning of the Atlantic Ocean as a whole. This leakage between these two subtropical gyres takes place south of Africa. The main mechanisms are the intermittent shedding of Agulhas rings from the retroflection of the Agulhas Current and the advection of Agulhas filaments from the border of the Agulhas Current, both of which move northwestward into the South Atlantic. The subsequent behaviour and mixing of Agulhas rings has been much studied over the past years, that of Agulhas filaments not at all. We report here on fortuitous hydrographic observations of the behaviour of an Agulhas filament that interacted with a number of mesoscale features shortly after formation. This suggests that Agulhas filaments may be involved in many other circulation elements and not only the Benguela upwelling front, as was surmised previously, and may mix out in a very site-specific region

Three-Dimensional Reconstruction of Planar Deformation Features from Single Electron Micrographs

Abstract: Dislocations are crystal defects responsible for plastic deformation, and understanding their behavior is key to the design of materials with better properties. Electron microscopy has been widely used to characterize dislocations, but the resulting images are only two-dimensional projections of the real defects. The current work introduces a framework to determine the sample and crystal orientations from micrographs with planar deformation features (twins, stacking faults, and slip bands) in three or four non-coplanar slip systems of an fcc material. This is then extended into a methodology for the three-dimensional reconstruction of dislocations lying on planes with a known orientation that can be easily coupled with a standard Burgers vector analysis, as proved here in a nickel-based superalloy. This technique can only be used in materials that show specific deformation conditions, but it is faster than other alternatives as it relies on the manual tracing of dislocations in a single micrograph

Dynamics of on-line Hebbian learning with structurally unrealizable restricted training sets

We present an exact solution for the dynamics of on-line Hebbian learning in neural networks, with restricted and unrealizable training sets. In contrast to other studies on learning with restricted training sets, unrealizability is here caused by structural mismatch, rather than data noise: the teacher machine is a perceptron with a reversed wedge-type transfer function, while the student machine is a perceptron with a sigmoidal transfer function. We calculate the glassy dynamics of the macroscopic performance measures, training error and generalization error, and the (non-Gaussian) student field distribution. Our results, which find excellent confirmation in numerical simulations, provide a new benchmark test for general formalisms with which to study unrealizable learning processes with restricted training sets.Comment: 7 pages including 3 figures, using IOP latex2e preprint class fil

The air–liquid interface model

The airway epithelium lining the airways is in first contact with the inhaled environment, which contains allergens, gaseous pollutants, particulates, and pathogenic microorganisms. It forms an ion- and size-selective barrier between the inhaled environment and the underlying tissue by the formation of intercellular tight junctions and adhesion junctions. Additionally, the airway epithelium plays an important role in innate immune defense, expressing receptors that recognize molecular patterns from pathogenic microbes, parasites, fungi, and allergens and danger signals from damaged cells, directing proinflammatory processes. Chronic lung diseases, such as asthma and chronic obstructive pulmonary disease, involve changes in airway epithelial function. For valuable insights into these changes, in vitro models should closely recapitulate human airway epithelial composition, three-dimensional structure, and function as an immunological barrier. The goal of this chapter is to review the literature on the use of air–liquid interface cultures to model the lung epithelium in health and disease.</p

Whole Genome Amplification of DNA for Genotyping Pharmacogenetics Candidate Genes

Whole genome amplification (WGA) technologies can be used to amplify genomic DNA when only small amounts of DNA are available. The Multiple Displacement Amplification Phi polymerase based amplification has been shown to accurately amplify DNA for a variety of genotyping assays; however, it has not been tested for genotyping many of the clinically relevant genes important for pharmacogenetic studies, such as the cytochrome P450 genes, that are typically difficult to genotype due to multiple pseudogenes, copy number variations, and high similarity to other related genes. We evaluated whole genome amplified samples for Taqman™ genotyping of SNPs in a variety of pharmacogenetic genes. In 24 DNA samples from the Coriell human diversity panel, the call rates, and concordance between amplified (∼200-fold amplification) and unamplified samples was 100% for two SNPs in CYP2D6 and one in ESR1. In samples from a breast cancer clinical trial (Trial 1), we compared the genotyping results in samples before and after WGA for three SNPs in CYP2D6, one SNP in CYP2C19, one SNP in CYP19A1, two SNPs in ESR1, and two SNPs in ESR2. The concordance rates were all >97%. Finally, we compared the allele frequencies of 143 SNPs determined in Trial 1 (whole genome amplified DNA) to the allele frequencies determined in unamplified DNA samples from a separate trial (Trial 2) that enrolled a similar population. The call rates and allele frequencies between the two trials were 98 and 99.7%, respectively. We conclude that the whole genome amplified DNA is suitable for Taqman™ genotyping for a wide variety of pharmacogenetically relevant SNPs

Fermion Quasi-Spherical Harmonics

Spherical Harmonics, $Y_\ell^m(\theta,\phi)$, are derived and presented (in a Table) for half-odd-integer values of $\ell$ and $m$. These functions are eigenfunctions of $L^2$ and $L_z$ written as differential operators in the spherical-polar angles, $\theta$ and $\phi$. The Fermion Spherical Harmonics are a new, scalar and angular-coordinate-dependent representation of fermion spin angular momentum. They have $4\pi$ symmetry in the angle $\phi$, and hence are not single-valued functions on the Euclidean unit sphere; they are double-valued functions on the sphere, or alternatively are interpreted as having a double-sphere as their domain.Comment: 16 pages, 2 Tables. Submitted to J.Phys.

Wave-packet recollision and pulse-shape effects in high-harmonic generation

Published versio

Strong and Tunable Nonlinear Optomechanical Coupling in a Low-Loss System

A major goal in optomechanics is to observe and control quantum behavior in a system consisting of a mechanical resonator coupled to an optical cavity. Work towards this goal has focused on increasing the strength of the coupling between the mechanical and optical degrees of freedom; however, the form of this coupling is crucial in determining which phenomena can be observed in such a system. Here we demonstrate that avoided crossings in the spectrum of an optical cavity containing a flexible dielectric membrane allow us to realize several different forms of the optomechanical coupling. These include cavity detunings that are (to lowest order) linear, quadratic, or quartic in the membrane's displacement, and a cavity finesse that is linear in (or independent of) the membrane's displacement. All these couplings are realized in a single device with extremely low optical loss and can be tuned over a wide range in situ; in particular, we find that the quadratic coupling can be increased three orders of magnitude beyond previous devices. As a result of these advances, the device presented here should be capable of demonstrating the quantization of the membrane's mechanical energy.Comment: 12 pages, 4 figures, 1 tabl