Optical activity induced by curvature in a gravitational pp-wave background

We study optical activity induced by curvature. The optical activity model we present has two phenomenological gyration parameters, within which we analyze three model cases, namely, an exactly integrable model, the Landau-Lifshitz model and the Fedorov model, these latter two are solved in the short wavelength approximation. The model background is a gravitational pp-wave. The solutions show that the optical activity induced by curvature leads to Faraday rotation.Comment: 16 pages, late

Expanding and connecting the annotation tool ELAN

The annotation tool ELAN allows for adding time-linked textual annotations to digital audio and video recordings. It is applied in various disciplines within the humanities, with linguistics, sign language and gesture research represented most prominently in its user base. This paper highlights new developments in ELAN with an emphasis on those features that introduced new technological and methodological approaches to analysing both audio/video and derived textual data

Magneto-optical properties of (Ga,Mn)As: an ab--initio determination

The magneto-optical properties of (Ga,Mn)As have been determined within density functional theory using the highly precise full-potential linear augmented plane wave (FLAPW) method. A detailed investigation of the electronic and magnetic properties in connection to the magneto-optic effects is reported. The spectral features of the optical tensor in the 0-10 eV energy range are analyzed in terms of the band structure and density of states and the essential role of the dipole matrix elements is highlighted by means of Brillouin zone dissection. Using an explicit representation of the Kerr angle in terms of real and imaginary parts of the tensor components, a careful analysis of the Kerr spectra is also presented. The results of our study can be summarized as follows: i) different types of interband transitions do contribute in shaping the conductivity tensor; ii) the dipole matrix elements are important in obtaining the correct optical spectra; iii) different regions in the irreducible Brillouin zone contribute to the conductivity very differently; iv) a minimum in the Re $\sigma_{xx}$ spectra can give rise to a large Kerr rotation angle in the same energy region; and v) materials engineering via the magneto-optical Kerr effect is possible provided that the electronic structure of the material can be tuned in such a way as to \emph{enhance} the depth of the minima of Re $\sigma_{xx}$.Comment: 33 pages, 7 figures, accepted for publication in Phys. Rev.

Gastric xanthomatosis and cholestasis

We report two cases of gastric xanthomatosis which developed in patients with marked cholestasis. In both cases, one with acute and one with chronic cholestasis, the gastric xanthomas disappeared with resolution of the cholestasis. A review of the literature is also provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44402/1/10620_2005_Article_BF01303212.pd

Optimizing innovation, carbon and health in transport: assessing socially optimal electric mobility and vehicle-to-grid pathways in Denmark

This paper examines the social costs and benefits of potential configurations of electric vehicle deployment, including and excluding vehicle-to-grid. To fully explore the benefits and costs of different electric vehicle pathways, four different scenarios are devised with both today’s and 2030 electricity grid in Denmark. These scenarios combine different levels of electric vehicle implementation and communication ability, i.e. smart charging or full bi-directionality, and then paired with different levels of future renewable energy implementation. Then, the societal costs of all scenarios are calculated, including carbon and health externalities to find the least-cost mix of electric vehicles for society. The most cost-effective penetration of electric vehicles in the near future is found to be 27%, increasing to 75% by 2030. This would equate to a $34 billion reduction to societal costs in 2030, a decrease of 30$1,200 in 2030. However, current vehicle capital cost differences, a lack of willingness to pay for electric vehicles, and consumer discount rates are substantial barriers to electric vehicle deployment in Denmark in the near term

Effect of transition layers on the electromagnetic properties of composites containing conducting fibres

The approach to calculating the effective dielectric and magnetic response in bounded composite materials is developed. The method is essentially based on the renormalisation of the dielectric matrix parameters to account for the surface polarisation and the displacement currents at the interfaces. This makes it possible the use of the effective medium theory developed for unbounded materials, where the spatially-dependent local dielectric constant and magnetic permeability are introduced. A detailed mathematical analysis is given for a dielectric layer having conducting fibres with in-plane positions. The surface effects are most essential at microwave frequencies in correspondence to the resonance excitation of fibres. In thin layers (having a thickness of the transition layer), the effective dielectric constant has a dispersion region at much higher frequencies compared to those for unbounded materials, exhibiting a strong dependence on the layer thickness. For the geometry considered, the effective magnetic permeability differs slightly from unity and corresponds to the renormalised matrix parameter. The magnetic effect is due entirely to the existence of the surface displacement currents.Comment: PDF, 33 pages, 10 figure

Electrodynamics of Correlated Electron Materials

We review studies of the electromagnetic response of various classes of correlated electron materials including transition metal oxides, organic and molecular conductors, intermetallic compounds with $d$- and $f$-electrons as well as magnetic semiconductors. Optical inquiry into correlations in all these diverse systems is enabled by experimental access to the fundamental characteristics of an ensemble of electrons including their self-energy and kinetic energy. Steady-state spectroscopy carried out over a broad range of frequencies from microwaves to UV light and fast optics time-resolved techniques provide complimentary prospectives on correlations. Because the theoretical understanding of strong correlations is still evolving, the review is focused on the analysis of the universal trends that are emerging out of a large body of experimental data augmented where possible with insights from numerical studies.Comment: 78 pages, 55 figures, 984 reference

Comparisons between Chemical Mapping and Binding to Isoenergetic Oligonucleotide Microarrays Reveal Unexpected Patterns of Binding to the Bacillus subtilis RNase P RNA Specificity Domain†

ABSTRACT: Microarrays with isoenergetic pentamer and hexamer 20-O-methyl oligonucleotide probes with LNA (locked nucleic acid) and 2,6-diaminopurine substitutions were used to probe the binding sites on theRNase P RNA specificity domain of Bacillus subtilis. Unexpected binding patterns were revealed. Because of their enhanced binding free energies, isoenergetic probes can break short duplexes, merge adjacent loops, and/or induce refolding. This suggests new approaches to the rational design of short oligonucleotide therapeutics but limits the utility of microarrays for providing constraints for RNA structure determination. The microarray results are compared to results from chemical mapping experiments, which do provide constraints. Results from both types of experiments indicate that the RNase P RNA folds similarly in 1MNaþ and 10 mMMg2þ. Binding of RNA to RNA is important for many natural func-tions, includingproteinsynthesis (1,2), translationregulation (3,4), gene silencing (5, 6), metabolic regulation (7), RNAmodification (8, 9), etc. (10-13). Binding of oligonucleotides toRNAs is impor-tant for therapeutic approaches, such as siRNA, ribozymes, and antisense therapy (14, 15).Much remains to bediscovered, however, of the rules for predicting binding sites andpotential therapeutics

Cultural Phylogenetics of the Tupi Language Family in Lowland South America

Background: Recent advances in automated assessment of basic vocabulary lists allow the construction of linguistic phylogenies useful for tracing dynamics of human population expansions, reconstructing ancestral cultures, and modeling transition rates of cultural traits over time. Methods: Here we investigate the Tupi expansion, a widely-dispersed language family in lowland South America, with a distance-based phylogeny based on 40-word vocabulary lists from 48 languages. We coded 11 cultural traits across the diverse Tupi family including traditional warfare patterns, post-marital residence, corporate structure, community size, paternity beliefs, sibling terminology, presence of canoes, tattooing, shamanism, men’s houses, and lip plugs. Results/Discussion: The linguistic phylogeny supports a Tupi homeland in west-central Brazil with subsequent major expansions across much of lowland South America. Consistently, ancestral reconstructions of cultural traits over the linguistic phylogeny suggest that social complexity has tended to decline through time, most notably in the independent emergence of several nomadic hunter-gatherer societies. Estimated rates of cultural change across the Tupi expansion are on the order of only a few changes per 10,000 years, in accord with previous cultural phylogenetic results in other languag

Height and body-mass index trajectories of school-aged children and adolescents from 1985 to 2019 in 200 countries and territories: a pooled analysis of 2181 population-based studies with 65 million participants

Summary Background Comparable global data on health and nutrition of school-aged children and adolescents are scarce. We aimed to estimate age trajectories and time trends in mean height and mean body-mass index (BMI), which measures weight gain beyond what is expected from height gain, for school-aged children and adolescents. Methods For this pooled analysis, we used a database of cardiometabolic risk factors collated by the Non-Communicable Disease Risk Factor Collaboration. We applied a Bayesian hierarchical model to estimate trends from 1985 to 2019 in mean height and mean BMI in 1-year age groups for ages 5–19 years. The model allowed for non-linear changes over time in mean height and mean BMI and for non-linear changes with age of children and adolescents, including periods of rapid growth during adolescence. Findings We pooled data from 2181 population-based studies, with measurements of height and weight in 65 million participants in 200 countries and territories. In 2019, we estimated a difference of 20 cm or higher in mean height of 19-year-old adolescents between countries with the tallest populations (the Netherlands, Montenegro, Estonia, and Bosnia and Herzegovina for boys; and the Netherlands, Montenegro, Denmark, and Iceland for girls) and those with the shortest populations (Timor-Leste, Laos, Solomon Islands, and Papua New Guinea for boys; and Guatemala, Bangladesh, Nepal, and Timor-Leste for girls). In the same year, the difference between the highest mean BMI (in Pacific island countries, Kuwait, Bahrain, The Bahamas, Chile, the USA, and New Zealand for both boys and girls and in South Africa for girls) and lowest mean BMI (in India, Bangladesh, Timor-Leste, Ethiopia, and Chad for boys and girls; and in Japan and Romania for girls) was approximately 9–10 kg/m2. In some countries, children aged 5 years started with healthier height or BMI than the global median and, in some cases, as healthy as the best performing countries, but they became progressively less healthy compared with their comparators as they grew older by not growing as tall (eg, boys in Austria and Barbados, and girls in Belgium and Puerto Rico) or gaining too much weight for their height (eg, girls and boys in Kuwait, Bahrain, Fiji, Jamaica, and Mexico; and girls in South Africa and New Zealand). In other countries, growing children overtook the height of their comparators (eg, Latvia, Czech Republic, Morocco, and Iran) or curbed their weight gain (eg, Italy, France, and Croatia) in late childhood and adolescence. When changes in both height and BMI were considered, girls in South Korea, Vietnam, Saudi Arabia, Turkey, and some central Asian countries (eg, Armenia and Azerbaijan), and boys in central and western Europe (eg, Portugal, Denmark, Poland, and Montenegro) had the healthiest changes in anthropometric status over the past 3·5 decades because, compared with children and adolescents in other countries, they had a much larger gain in height than they did in BMI. The unhealthiest changes—gaining too little height, too much weight for their height compared with children in other countries, or both—occurred in many countries in sub-Saharan Africa, New Zealand, and the USA for boys and girls; in Malaysia and some Pacific island nations for boys; and in Mexico for girls. Interpretation The height and BMI trajectories over age and time of school-aged children and adolescents are highly variable across countries, which indicates heterogeneous nutritional quality and lifelong health advantages and risks