Monte Carlo aided design of the inner muon veto detectors for the Double Chooz experiment

The Double Chooz neutrino experiment aims to measure the last unknown neutrino mixing angle theta_13 using two identical detectors positioned at sites both near and far from the reactor cores of the Chooz nuclear power plant. To suppress correlated background induced by cosmic muons in the detectors, they are protected by veto detector systems. One of these systems is the inner muon veto. It is an active liquid scintillator based detector and instrumented with encapsulated photomultiplier tubes. In this paper we describe the Monte Carlo aided design process of the inner muon veto, that resulted in a detector configuration with 78 PMTs yielding an efficiency of 99.978 +- 0.004% for rejecting muon events and an efficiency of >98.98% for rejecting correlated events induced by muons. A veto detector of this design is currently used at the far detector site and will be built and incorporated as the muon identification system at the near site of the Double Chooz experiment

Assessing the Variance in Pupil Attainment: How Important is the School Attended?

We explore the variation in pupil attainment at the end of secondary schooling in England. The paper links data on all schools and all pupils within these schools to analyse the role of the school in accounting for this variation. We analyse a number of different indicators of pupil attainment including value added between the end of primary and secondary schooling and attainment levels at the end of secondary schooling. We examine indicators that were the focus of the school accounting framework as well as other indicators that were not directly part of how schools were assessed. We show that schools account for a minority of the variance in pupil attainment, and the extent of the variation accounted for by the school is sensitive to the measure of pupil attainment used. In addition, we find that the majority of the explained school-level variance in attainment is related to school composition. However, most of the variance in attainment remains unexplained, raising questions about what other factors contribute to the variation in school performance

The Stochastic Dynamics of Rectangular and V-shaped Atomic Force Microscope Cantilevers in a Viscous Fluid and Near a Solid Boundary

Using a thermodynamic approach based upon the fluctuation-dissipation theorem we quantify the stochastic dynamics of rectangular and V-shaped microscale cantilevers immersed in a viscous fluid. We show that the stochastic cantilever dynamics as measured by the displacement of the cantilever tip or by the angle of the cantilever tip are different. We trace this difference to contributions from the higher modes of the cantilever. We find that contributions from the higher modes are significant in the dynamics of the cantilever tip-angle. For the V-shaped cantilever the resulting flow field is three-dimensional and complex in contrast to what is found for a long and slender rectangular cantilever. Despite this complexity the stochastic dynamics can be predicted using a two-dimensional model with an appropriately chosen length scale. We also quantify the increased fluid dissipation that results as a V-shaped cantilever is brought near a solid planar boundary.Comment: 10 pages, 15 images, corrected equation (8

Dynamics of a trapped Brownian particle in shear flows

The Brownian motion of a particle in a harmonic potential, which is simultaneously exposed either to a linear shear flow or to a plane Poiseuille flow is investigated. In the shear plane of both flows the probability distribution of the particle becomes anisotropic and the dynamics is changed in a characteristic manner compared to a trapped particle in a quiescent fluid. The particle distribution takes either an elliptical or a parachute shape or a superposition of both depending on the mean particle position in the shear plane. Simultaneously, shear-induced cross-correlations between particle fluctuations along orthogonal directions in the shear plane are found. They are asymmetric in time. In Poiseuille flow thermal particle fluctuations perpendicular to the flow direction in the shear plane induce a shift of the particle's mean position away from the potential minimum. Two complementary methods are suggested to measure shear-induced cross-correlations between particle fluctuations along orthogonal directions.Comment: 14 pages, 7 figure

Network formation of tissue cells via preferential attraction to elongated structures

Vascular and non-vascular cells often form an interconnected network in vitro, similar to the early vascular bed of warm blooded embryos. Our time-lapse recordings show that the network forms by extending sprouts, i.e., multicellular linear segments. To explain the emergence of such structures, we propose a simple model of preferential attraction to stretched cells. Numerical simulations reveal that the model evolves into a quasi-stationary pattern containing linear segments, which interconnect above the critical volume fraction of 0.2. In the quasi-stationary state the generation of new branches offset the coarsening driven by surface tension. In agreement with empirical data, the characteristic size of the resulting polygonal pattern is density-independent within a wide range of volume fractions

Effects of Increased Inclusion of Algae Meal on Finishing Steer Performance and Carcass Characteristics

Algae meal is a novel feedstuff comprised of partially deoiled microalgae (43% DM basis) and soyhulls (57% DM basis). It appears algae meal may have a lesser energy value than corn. However, algae meal is readily consumed by steers and has minimal effects on carcass performance. This suggests that algae meal could potentially serve as a replacement for corn and a valuable component of feedlot diets

Isospin splittings of meson and baryon masses from three-flavor lattice QCD + QED

Lattice QCD simulations are now reaching a precision where isospin breaking effects become important. Previously, we have developed a program to systematically investigate the pattern of flavor symmetry beaking within QCD and successfully applied it to meson and baryon masses involving up, down and strange quarks. In this Letter we extend the calculations to QCD + QED and present our first results on isospin splittings in the pseudoscalar meson and baryon octets. In particular, we obtain the nucleon mass difference of M_n-M_p=1.35(18)(8)\,\mbox{MeV} and the electromagnetic contribution to the pion splitting M_{\pi^+}-M_{\pi^0}=4.60(20)\,\mbox{MeV}. Further we report first determination of the separation between strong and electromagnetic contributions in the $\bar{MS}$ scheme.Comment: 14 pages, 10 figures, text and figures added, Journal versio

Experimental determination of the degree of quantum polarisation of continuous variable states

We demonstrate excitation-manifold resolved polarisation characterisation of continuous-variable (CV) quantum states. In contrast to traditional characterisation of polarisation that is based on the Stokes parameters, we experimentally determine the Stokes vector of each excitation manifold separately. Only for states with a given photon number does the methods coincide. For states with an indeterminate photon number, for example Gaussian states, the employed method gives a richer and more accurate description. We apply the method both in theory and in experiment to some common states to demonstrate its advantages.Comment: 5 page

Calibration of optical tweezers with positional detection in the back-focal-plane

We explain and demonstrate a new method of force- and position-calibration for optical tweezers with back-focal-plane photo detection. The method combines power spectral measurements of thermal motion and the response to a sinusoidal motion of a translation stage. It consequently does not use the drag coefficient of the trapped ob ject as an input. Thus, neither the viscosity, nor the size of the trapped ob ject, nor its distance to nearby surfaces need to be known. The method requires only a low level of instrumentation and can be applied in situ in all spatial dimensions. It is both accurate and precise: true values are returned, with small error-bars. We tested this experimentally, near and far from surfaces. Both position- and force-calibration were accurate to within 3%. To calibrate, we moved the sample with a piezo-electric translation stage, but the laser beam could be moved instead, e.g. by acousto-optic deflectors. Near surfaces, this precision requires an improved formula for the hydrodynamical interaction between an infinite plane and a micro-sphere in non-constant motion parallel to it. We give such a formula.Comment: Submitted to: Review of Scientific Instruments. 13 pages, 5 figures. Appendix added (hydrodynamically correct calibration

Understanding and optimising an identification/brief advice (IBA) service about alcohol in the community pharmacy setting

This is the final report of an evaluation into the identification/brief advice (IBA) service about alcohol in community pharmacy settings in the North West of England. Since 2007, almost 100 pharmacies in the North West have - at some point - been commissioned to provide an identification and brief advice (IBA) service for alcohol. This evaluation sought to understand how the service had been adapted for and implemented in the community pharmacy setting, and how its potential might be maximised. Its aims were: 1. To characterise, consolidate and optimise both the constant and variable elements of the pharmacy alcohol identification/brief advice (IBA) service in NHS Northwest, and 2. To inform planning for current and future pharmacy based services promoting safe consumption of alcohol. The evaluation was split into three main workstreams, supported by a preliminary scoping phase, and combined quantitative and qualitative methods: • Descriptive and comparative statistical analysis of pharmacy alcohol IBA data; • In-pharmacy work, including observation of staff engagement with customers, recording consultations between staff and customers, follow-up telephone interviews with customers, and group feedback interviews with pharmacy staff; • Stakeholder engagement through self-completion surveys, semi-structured interviews and a workshop. This report gives the background to the project, and details the methods, results and implications