The crossover between lasing and polariton condensation in optical microcavities

We study a model of a photon mode dipole-coupled to a medium of two-level oscillators in a microcavity in the presence of dephasing processes introduced by coupling to external baths. Decoherence processes can be classified as pair-breaking or non-pair-breaking in analogy with magnetic or non-magnetic impurities in superconductors. In the absence of dephasing, the ground state of the model is a polariton condensate with a gap in the excitation spectrum. Increase of the pair-breaking parameter $\gamma$ reduces the gap, which becomes zero at a critical value $\gamma_{C1}$; for large $\gamma$, the conventional laser regime is obtained in a way that demonstrates its close analogy to a gapless superconductor. In contrast, weak non-pair-breaking processes have no qualitative effect on the condensate or the existence of a gap, although they lead to inhomogeneous broadening of the excitations

An Equation for the Prediction of Human Skin Permeability of Neutral Molecules, Ions and Ionic Species

yesExperimental values of permeability coefficients, as log Kp, of chemical compounds across human skin were collected by carefully screening the literature, and adjusted to 37 °C for the effect of temperature. The values of log Kp for partially ionized acids and bases were separated into those for their neutral and ionic species, forming a total data set of 247 compounds and species (including 35 ionic species). The obtained log Kp values have been regressed against Abraham solute descriptors to yield a correlation equation with R2 = 0.866 and SD = 0.432 log units. The equation can provide valid predictions for log Kp of neutral molecules, ions and ionic species, with predictive R2 = 0.858 and predictive SD = 0.445 log units calculated by the leave-one-out statistics. The predicted log Kp values for Na+ and Et4N+ are in good agreement with the observed values. We calculated the values of log Kp of ketoprofen as a function of the pH of the donor solution, and found that log Kp markedly varies only when ketoprofen is largely ionized. This explains why models that neglect ionization of permeants still yield reasonable statistical results. The effect of skin thickness on log Kp was investigated by inclusion of two indicator variables, one for intermediate thickness skin and one for full thickness skin, into the above equation. The newly obtained equations were found to be statistically very close to the above equation. Therefore, the thickness of human skin used makes little difference to the experimental values of log Kp

Effects of Boundary Conditions on Single-File Pedestrian Flow

In this paper we investigate effects of boundary conditions on one dimensional pedestrian flow which involves purely longitudinal interactions. Qualitatively, stop-and-go waves are observed under closed boundary condition and dissolve when the boundary is open. To get more detailed information the fundamental diagrams of the open and closed systems are compared using Voronoi-based measurement method. Higher maximal specific flow is observed from the pedestrian movement at open boundary condition

Generation and Evolution of Spin Entanglement in NRQED

A complete analysis on the generation of spin entanglement from NRQED is presented. The results of entanglement are obtained with relativistic correction to the leading order of (v/c)^2. It is shown that to this order the degree of entanglement of a singlet state does not change under time evolution whereas the triplet state can change.Comment: 8 pages, 1 figure, to appear in Phys. Rev.

Problems in the classic frequency shift islanding detection methods applied to energy storage converters and a coping strategy

This paper first derives a usable formula based on the parallel R, L, C load and the conclusions from frequency shift islanding detection methods in current literature: the angle by which the total output current of the distributed resources (DR) units leads the point of common coupling (PCC) voltage must be conducted to have the same shifting direction as the load admittance angle during the variation of the frequency. On the basis of the formula and multi-DR operation, the scenarios in which the classic frequency shift methods are applied to energy storage converters are analyzed. The results indicate that the setting of the angle by which the energy storage converter current leads the PCC voltage may need to be modified when running state changes. It results in the problems that the classic methods are not applicable for non-UPF (unity power factor) control and have to distinguish between generation mode and consumption mode for UPF control. On account of the problems, a coping strategy, i.e. an improved method, is proposed. The analyses indicate that the improved method is applicable in every state. The last simulations and experiments confirm the preceding conclusions

An irregular current injection islanding detection method based on an improved impedance measurement scheme

One class of islanding detection methods, known as impedance measurement-based methods and voltage change monitoring-based methods, are implemented through injecting irregular currents into the network, for which reason they are defined in this paper as irregular current injection methods. This paper indicates that such methods may be affected by distributed generation (DG) unit cut-in events. Although the network impedance change can still be used as a judgment basis for islanding detection, the general impedance measurement scheme cannot separate island events from DG unit cut-in events in multi-DG operation. In view of this, this paper proposes a new islanding detection method based on an improved impedance measurement scheme, i.e., dynamic impedance measurement, which will not be affected by DG unit cut-in events and can further assist some other equipment in islanding detection. The simulations and experiments verify the stated advantages of the new islanding detection method

The prediction of blood–tissue partitions, water–skin partitions and skin permeation for agrochemicals

YesBACKGROUND: There is considerable interest in the blood–tissue distribution of agrochemicals, and a number of researchershave developed experimental methods for in vitro distribution. These methods involve the determination of saline–blood andsaline–tissue partitions; not only are they indirect, but they do not yield the required in vivo distribution.RESULTS: The authors set out equations for gas–tissue and blood–tissue distribution, for partition from water into skin andfor permeation from water through human skin. Together with Abraham descriptors for the agrochemicals, these equationscan be used to predict values for all of these processes. The present predictions compare favourably with experimental in vivoblood–tissue distribution where available. The predictions require no more than simple arithmetic.CONCLUSIONS: The present method represents a much easier and much more economic way of estimating blood–tissuepartitions than the method that uses saline–blood and saline–tissue partitions. It has the added advantages of yielding therequired in vivo partitions and being easily extended to the prediction of partition of agrochemicals from water into skin andpermeation from water through skin

A simple method for estimating in vitro air-tissue and in vivo blood-tissue partition coefficients

YesA simple method is reported for the estimation of in vivo air-tissue partition coefficients of VOCs and of in vitro blood-tissue partition coefficients for volatile organic compounds and other compounds. Linear free energy relationships for tissues such as brain, muscle, liver, lung, kidney, heart, skin and fat are available and once the Abraham descriptors are known for a compound, no more than simple arithmetic is required to estimate air-tissue and blood-tissue partitions

CollapsABEL: An R library for detecting compound heterozygote alleles in genome-wide association studies

Background: Compound Heterozygosity (CH) in classical genetics is the presence of two different recessive mutations at a particular gene locus. A relaxed form of CH alleles may account for an essential proportion of the missing heritability, i.e. heritability of phenotypes so far not accounted for by single genetic variants. Methods to detect CH-like effects in genome-wide association studies (GWAS) may facilitate explaining the missing heritability, but to our knowledge no viable software tools for this purpose are currently available. Results: In this work we present the Generalized Compound Double Heterozygosity (GCDH) test and its implementation in the R package CollapsABEL. Time-consuming procedures are optimized for computational efficiency using Java or C++. Intermediate results are stored either in an SQL database or in a so-called big.matrix file to achieve reasonable memory footprint. Our large scale simulation studies show that GCDH is capable of discovering genetic associations due to CH-like interactions with much higher power than a conventional single-SNP approach under various settings, whether the causal genetic variations are available or not. CollapsABEL provides a user-friendly pipeline for genotype collapsing, statistical testing, power estimation, type I error control and graphics generation in the R language. Conclusions: CollapsABEL provides a computationally efficient solution for screening general forms of CH alleles in densely imputed microarray or whole genome sequencing datasets. The GCDH test provides an improved power over single-SNP based methods in detecting the prevalence of CH in human complex phenotypes, offering an opportunity for tackling the missing heritability problem. Binary and source packages of CollapsABEL are available on CRAN (https://cran.r-project.org/web/packages/CollapsABEL) and the website of the GenABEL project (http://www.genabel.org/packages)

GAGA: A New Algorithm for Genomic Inference of Geographic Ancestry Reveals Fine Level Population Substructure in Europeans

Attempts to detect genetic population substructure in humans are troubled by the fact that the vast majority of the total amount of observed genetic variation is present within populations rather than between populations. Here we introduce a new algorithm for transforming a genetic distance matrix that reduces the within-population variation considerably. Extensive computer simulations revealed that the transformed matrix captured the genetic population differentiation better than the original one which was based on the T1 statistic. In an empirical genomic data set comprising 2,457 individuals from 23 different European subpopulations, the proportion of individuals that were determined as a genetic neighbour to another individual from the same sampling location increased from 25% with the original matrix to 52% with the transformed matrix. Similarly, the percentage of genetic variation explained between populations by means of Analysis of Molecular Variance (AMOVA) increased from 1.62% to 7.98%. Furthermore, the first two dimensions of a classical multidimensional scaling (MDS) using the transformed matrix explained 15% of the variance, compared to 0.7% obtained with the original matrix. Application of MDS with Mclust, SPA with Mclust, and GemTools algorithms to the same dataset also showed that the transformed matrix gave a better association of the genetic clusters with the sampling locations, and particularly so when it was used in the AMOVA framework with a genetic algorithm. Overall, the new matrix transformation introduced here substantially reduces the within population genetic differentiation, and can be broadly applied to methods such as AMOVA to enhance their sensitivity to reveal population substructure. We herewith provide a publically available (http://www.erasmusmc.nl/fmb/resources/GAGA) model-free method for improved genetic population substructure detection that can be applied to human as well as any other species data in future studies relevant to evolutionary biology, behavioural ecology, medicine, and forensics