Signalling C-Type Lectins in Antimicrobial Immunity

Funding: This work was funded by the Wellcome Trust, Medical Research Council and the University of Aberdeen. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

Many-body quantum dynamics of polarisation squeezing in optical fibre

We report new experiments that test quantum dynamical predictions of polarization squeezing for ultrashort photonic pulses in a birefringent fibre, including all relevant dissipative effects. This exponentially complex many-body problem is solved by means of a stochastic phase-space method. The squeezing is calculated and compared to experimental data, resulting in excellent quantitative agreement. From the simulations, we identify the physical limits to quantum noise reduction in optical fibres. The research represents a significant experimental test of first-principles time-domain quantum dynamics in a one-dimensional interacting Bose gas coupled to dissipative reservoirs.Comment: 4 pages, 4 figure

Feshbach Resonance and Growth of a Bose-Einstein Condensate

Gross-Pitaevskii equation with gain is used to model Bose Einstein condensation (BEC) fed by the surrounding thermal cloud. It is shown that the number of atoms continuously injected into BEC from the reservoir can be controlled by applying the external magnetic field via Feshbach resonance.Comment: 4 page

Dynamic response of strongly correlated Fermi gases in the quantum virial expansion

By developing a quantum virial expansion theory, we quantitatively calculate the dynamic density response function of a trapped strongly interacting Fermi gas at high temperatures near unitarity. A clear transition from atomic to molecular responses is identified in the spectra when crossing from the BCS to BEC regimes, in qualitative agreement with recent Bragg spectroscopy observations. Our virial expansion method provides a promising way to solve the challenging strong-coupling problems and is applicable to other dynamical properties of strongly correlated Fermi gases.Comment: 5 pages, 4 figures; published version in Phys. Rev. A. The quantum virial expansion of single-particle spectral function is discussed in arXiv:1003.1538 (Phys. Rev. Lett. 104, 240407 (2010)

Some Aspects of the Biology of a Predaceous Anthomyiid Fly, \u3ci\u3eCoenosia Tigrina\u3c/i\u3e

The results of a two-year study in Michigan on the incidence of Coenosia tigrina adults under different onion production practices is presented. In Michigan, C. tigrina has three generations and is more abundant in organic agroecosystems than chemically-intensive onion production systems

Spherical Formulation for Diagramatic Evaluations on a Manifold with Boundary

The mathematical formalism necessary for the diagramatic evaluation of quantum corrections to a conformally invariant field theory for a self-interacting scalar field on a curved manifold with boundary is considered. The evaluation of quantum corrections to the effective action past one-loop necessitates diagramatic techniques. Diagramatic evaluations and higher loop-order renormalisation can be best accomplished on a Riemannian manifold of constant curvature accommodating a boundary of constant extrinsic curvature. In such a context the stated evaluations can be accomplished through a consistent interpretation of the Feynman rules within the spherical formulation of the theory for which the method of images allows. To this effect, the mathematical consequences of such an interpretation are analyzed and the spherical formulation of the Feynman rules on the bounded manifold is, as a result, developed.Comment: 12 pages, references added. To appear in Classical and Quantum Gravit

Differential equations for multi-loop integrals and two-dimensional kinematics

In this paper we consider multi-loop integrals appearing in MHV scattering amplitudes of planar N=4 SYM. Through particular differential operators which reduce the loop order by one, we present explicit equations for the two-loop eight-point finite diagrams which relate them to massive hexagons. After the reduction to two-dimensional kinematics, we solve them using symbol technology. The terms invisible to the symbols are found through boundary conditions coming from double soft limits. These equations are valid at all-loop order for double pentaladders and allow to solve iteratively loop integrals given lower-loop information. Comments are made about multi-leg and multi-loop integrals which can appear in this special kinematics. The main motivation of this investigation is to get a deeper understanding of these tools in this configuration, as well as for their application in general four-dimensional kinematics and to less supersymmetric theories.Comment: 25 pages, 7 figure

Nonclassical correlations in damped quantum solitons

Using cumulant expansion in Gaussian approximation, the internal quantum statistics of damped soliton-like pulses in Kerr media are studied numerically, considering both narrow and finite bandwidth spectral pulse components. It is shown that the sub-Poissonian statistics can be enhanced, under certain circumstances, by absorption, which damps out some destructive interferences. Further, it is shown that both the photon-number correlation and the correlation of the photon-number variance between different pulse components can be highly nonclassical even for an absorbing fiber. Optimum frequency windows are determined in order to realize strong nonclassical behavior, which offers novel possibilities of using solitons in optical fibers as a source of nonclassically correlated light beams.Comment: 15 pages, 11 PS figures (color

Effective diffusion constant in a two dimensional medium of charged point scatterers

We obtain exact results for the effective diffusion constant of a two dimensional Langevin tracer particle in the force field generated by charged point scatterers with quenched positions. We show that if the point scatterers have a screened Coulomb (Yukawa) potential and are uniformly and independently distributed then the effective diffusion constant obeys the Volgel-Fulcher-Tammann law where it vanishes. Exact results are also obtained for pure Coulomb scatterers frozen in an equilibrium configuration of the same temperature as that of the tracer.Comment: 9 pages IOP LaTex, no figure

Outcoupling from a Bose-Einstein condensate with squeezed light to produce entangled atom laser beams

We examine the properties of an atom laser produced by outcoupling from a Bose-Einstein condensate with squeezed light. We model the multimode dynamics of the output field and show that a significant amount of squeezing can be transfered from an optical mode to a propagating atom laser beam. We use this to demonstrate that two-mode squeezing can be used to produce twin atom laser beams with continuous variable entanglement in amplitude and phase.Comment: 11 pages, 14 figure