On the influence of a Coulomb-like potential induced by the Lorentz symmetry breaking effects on the Harmonic Oscillator

In this work, we obtain bound states for a nonrelativistic spin-half neutral particle under the influence of a Coulomb-like potential induced by the Lorentz symmetry breaking effects. We present a new possible scenario of studying the Lorentz symmetry breaking effects on a nonrelativistic quantum system defined by a fixed space-like vector field parallel to the radial direction interacting with a uniform magnetic field along the z-axis. Furthermore, we also discuss the influence of a Coulomb-like potential induced by Lorentz symmetry violation effects on the two-dimensional harmonic oscillator.Comment: 14 pages, no figure, this work has been accepted for publication in The European Physical Journal Plu

Resolution of the Klein Paradox

We present a resolution of the Klein paradox within the framework of one-particle relativistic quantum mechanics. Not only reflection becomes total but the vacuum remains neutral as well. This is accomplished by replacing the pair production process with virtual negative energy "incidence" within the barrier in a similar manner to what is done with image charges in electrostatic and virtual sources in optics.Comment: 9 pages, 8 figure

Efficacy and safety of 4 weeks' treatment with combined fluticasone furoate/vilanterol in a single inhaler given once daily in COPD: a placebo-controlled randomised trial

Background: Fluticasone furoate/vilanterol (FF/VI) is a novel once-daily (OD) inhaled corticosteroid/long-acting beta(2) agonist combination in development for chronic obstructive pulmonary disease (COPD) and asthma. Trial design: A multicentre, randomised, double-blind, parallel-group, placebo-controlled study. Methods: Participants were patients with moderate-to-severe COPD treated with placebo or FF/VI 400/25 mu g OD for 4 weeks. Study objectives were to assess the safety and efficacy of FF/VI 400/25 mg OD administered for 4 weeks via a novel dry powder inhaler. Co-primary end points were change from baseline in weighted mean (wm) heart rate 0-4 h postdose at day 28 and the incidence of adverse events (AEs). Secondary end points included change from baseline in trough forced expiratory volume in one second (FEV1) (23-24 h postdose; day 29) and wm FEV1 (0-4 h postdose; day 28). Patients were randomised to receive FF/VI 400/25 mg or placebo in a 2: 1 ratio; all patients and investigators were blinded to active or placebo treatment. Results: 60 patients (mean age 64 years) were randomised (FF/VI: n=40; placebo: n=20), and all contributed data to the analysis. Mean screening post-bronchodilator FEV1 per cent predicted was comparable between groups (FF/VI: 58.5%; placebo: 60.1%). The wm heart rate 0-4 h postdose was similar between groups (difference: 0.6 beats per minute; 95% CI -3.9 to 5.1). More on-treatment AEs were reported in the FF/VI group (68%) compared with the placebo group (50%). The most common drug-related AEs in the FF/VI group were oral candidiasis (8%) and dysphonia (5%). There were no clinically relevant effects on laboratory values, including glucose and potassium, or on vital signs or ECGs/Holters. The FF/VI group had statistically greater improvements compared with placebo in trough FEV1 (mean difference 183 ml) and 0-4 h postdose wm FEV1 (mean difference 236 ml). Conclusion: FF/VI has a good safety and tolerability profile and improves lung function compared with placebo in patients with COPD. Trial registration number: clinical trials. gov-NCT00731822

Magnetic ground state and magnon-phonon interaction in multiferroic h-YMnO3_3

Inelastic neutron scattering has been used to study the magneto-elastic excitations in the multiferroic manganite hexagonal YMnO$_3$. An avoided crossing is found between magnon and phonon modes close to the Brillouin zone boundary in the $(a,b)$-plane. Neutron polarization analysis reveals that this mode has mixed magnon-phonon character. An external magnetic field along the $c$-axis is observed to cause a linear field-induced splitting of one of the spin wave branches. A theoretical description is performed, using a Heisenberg model of localized spins, acoustic phonon modes and a magneto-elastic coupling via the single-ion magnetostriction. The model quantitatively reproduces the dispersion and intensities of all modes in the full Brillouin zone, describes the observed magnon-phonon hybridized modes, and quantifies the magneto-elastic coupling. The combined information, including the field-induced magnon splitting, allows us to exclude several of the earlier proposed models and point to the correct magnetic ground state symmetry, and provides an effective dynamic model relevant for the multiferroic hexagonal manganites.Comment: 12 pages, 10 figure

Atmospheric dynamics over Europe during the Younger Dryas revealed by palaeoglaciers

A dataset of 120 palaeoglaciers ranging from Morocco in the south to Svalbard in the north and from Ireland in the west to Turkey in the east, has been assembled from the literature. A robust quality control on the chronology was undertaken and, when derived from cosmogenic nuclides, ages were recalculated using the most up-to-date production rates. All the reconstructed glaciers date to the Younger Dryas. Frontal moraines/limits were used to initiate the palaeoglacier reconstructions using GlaRe, a GIS tool which generates an equilibrium profile ice surface along a single flowline and extrapolates this to out to a 3D ice surface. From the resulting glacier surfaces palaeo-ELAs were calculated within the GIS. Where multiple glaciers were reconstructed within in a region, a single ELA value was generated. Results show that ELAs decrease with latitude but have a more complex pattern with longitude. A database of 121 sites, spanning the same geographical range as the palaeoglaciers, was compiled for Younger Dryas temperature, determined from palaeoproxies, for example pollen, diatoms, coleoptera, chironimids etc. These proxy data were merged and interpolated to generate maps of average temperature for the warmest and coldest months and annual average temperature. Results show that, in general, temperature decreases with latitude. Temperature at the palaeo-ELAs were determined from the temperature maps using a lapse rate of 0.65C/100m and the precipitation required for equilibrium was calculated. Positive precipitation anomalies are found along much of the western seaboard of Europe, with the most striking positive anomalies present in the eastern Mediterranean. Negative precipitation anomalies appear on the northern side of the Alps. This pattern is interpreted to represent a southward displaced polar frontal jet stream with a concomitant track of Atlantic midlatitude depressions, leading to more frequent incursions of low pressure systems especially over the relatively warm eastern Mediterranean, enhancing cyclogenesis. This is similar to the modern Scandinavia (SCAND) pattern which, in its positive phase, is characterised by a high pressure anomaly over Fennoscandia and western Russia, negative pressure anomalies around the Iberian Peninsula and enhanced cyclogenesis in the central and eastern Mediterranean. During the YD the Fennoscandian Ice Sheet and permafrost across much of northern continental Europe and Russia would have generated a high pressure region leading to a persistent, enhanced SCAND circulation

Morphology of two dimensional fracture surface

We consider the morphology of two dimensional cracks observed in experimental results obtained from paper samples and compare these results with the numerical simulations of the random fuse model (RFM). We demonstrate that the data obey multiscaling at small scales but cross over to self-affine scaling at larger scales. Next, we show that the roughness exponent of the random fuse model is recovered by a simpler model that produces a connected crack, while a directed crack yields a different result, close to a random walk. We discuss the multiscaling behavior of all these models.Comment: slightly revise

Noninertial effects on a Dirac neutral particle inducing an analogue of the Landau quantization in the cosmic string spacetime

We discuss the behaviour of external fields that interact with a Dirac neutral particle with a permanent electric dipole moment in order to achieve relativistic bound states solutions in a noninertial frame and in the presence of a topological defect spacetime. We show that the noninertial effects of the Fermi-Walker reference frame induce a radial magnetic field even in the absence of magnetic charges, which is influenced by the topology of the cosmic string spacetime. We then discuss the conditions that the induced fields must satisfy to yield the relativistic bound states corresponding to the Landau-He-McKellar-Wilkens quantization in the cosmic string spacetime. Finally we obtain the Dirac spinors for positive-energy solutions and the Gordon decomposition of the Dirac probability current.Comment: 15 pages, no figure, this paper will be published in volume 42 of the Brazilian Journal of Physic

Pore-scale Modeling of Viscous Flow and Induced Forces in Dense Sphere Packings

We propose a method for effectively upscaling incompressible viscous flow in large random polydispersed sphere packings: the emphasis of this method is on the determination of the forces applied on the solid particles by the fluid. Pore bodies and their connections are defined locally through a regular Delaunay triangulation of the packings. Viscous flow equations are upscaled at the pore level, and approximated with a finite volume numerical scheme. We compare numerical simulations of the proposed method to detailed finite element (FEM) simulations of the Stokes equations for assemblies of 8 to 200 spheres. A good agreement is found both in terms of forces exerted on the solid particles and effective permeability coefficients

Reproductive Trade-Offs May Moderate the Impact of Gyrodactylus salaris in Warmer Climates

Gyrodactylus salaris is a notifiable freshwater ectoparasite of salmonids. Its primary host is Atlantic salmon (Salmo salar), upon which infections can cause death, and have led to massive declines in salmon numbers in Norway, where the parasite is widespread. Different strains of S. salar vary in their susceptibility, with Atlantic strains (such as those found in Norway) exhibiting no resistance to the parasite, and Baltic strains demonstrating an innate resistance sufficient to regulate parasite numbers on the host causing it to either die out or persist at a low level. In this study, Leslie matrix and compartmental models were used to generate data that demonstrated the population growth of G. salaris on an individual host is dependent on the total number of offspring per parasite, its longevity and the timing of its births. The data demonstrated that the key factor determining the rate of G. salaris population growth is the time at which the parasite first gives birth, with rapid birth rate giving rise to large population size. Furthermore, it was shown that though the parasite can give birth up to four times, only two births are required for the population to persist as long as the first birth occurs before a parasite is three days old. As temperature is known to influence the timing of the parasite's first birth, greater impact may be predicted if introduced to countries with warmer climates than Norway, such as the UK and Ireland which are currently recognised to be free of G. salaris. However, the outputs from the models developed in this study suggest that temperature induced trade-offs between the total number of offspring the parasite gives birth to and the first birth timing may prevent increased population growth rates over those observed in Norway

Co-production in distributed generation:Renewable energy and creating space for fitting infrastructure within landscapes

This review describes the infrastructural elements of the socio-technical system of power supply based on renewables and the role of landscape concerns in decision-making about emerging ‘intelligent grids’. The considerable land areas required for energy infrastructure call for sizable ‘distributed generation’ close to energy consumption. Securing community acceptance of renewables’ infrastructure, perceived impacts on the community, and ‘landscape justice’ requires two types of co-production: in power supply and in making space available. With co-production, landscape issues are prominent, for some options dominant. However, ‘objectification’ of landscape, such as the use of ‘visibility’ as proxy for ‘visual impact’, is part of lingering centralised and hierarchical approaches to the deployment of renewables. Institutional tendencies of centralisation and hierarchy, in power supply management as well as in siting, should be replaced by co-production, as follows from common pool resources theory. Co-production is the key to respecting landscape values, furthering justice, and achieving community acceptance