Massless monopoles and the moduli space approximation

We investigate the applicability of the moduli space approximation in theories with unbroken non-Abelian gauge symmetries. Such theories have massless magnetic monopoles that are manifested at the classical level as clouds of non-Abelian field surrounding one or more massive monopoles. Using an SO(5) example with one massive and one massless monopole, we compare the predictions of the moduli space approximation with the results of a numerical solution of the full field equations. We find that the two diverge when the cloud velocity becomes of order unity. After this time the cloud profile approximates a spherical wavefront moving at the speed of light. In the region well behind this wavefront the moduli space approximation continues to give a good approximation to the fields. We therefore expect it to provide a good description of the motion of the massive monopoles and of the transfer of energy between the massive and massless monopoles.Comment: 18 pages, 5 figure

A user guide for the GeoSure Extra : Debris Flow Susceptibility Model for Great Britain (Version 6.0)

This report is the published product of a study by the British Geological Survey (BGS) to produce a national scale Debris Flow Susceptibility Map for Great Britain. It builds on research BGS has conducted over the past decade investigating debris flows and extends the work conducted by Harrison et al., (2006) as part of the Transport Scotland Scottish Road Network Landslides Study (Winter et al., 2005, Winter et al., 2009). The Debris Flow Susceptibility Model provides information on the potential of the ground, at a given location, to form a debris flow. It is based on a combination of digital geological, hydrogeological and topographic data. The methodology develops an additional dimension to the BGS GeoSure Landslides surface layer (Dashwood et al., 2014) and is designed for users interested specifically in debris flow susceptibility. This document outlines the background to why the dataset was created, its potential uses and gives a brief description of the GIS raster file. Technical information regarding the GIS and how the data were created is described and advice is provided on using the dataset

Creating a Debris Flow Susceptibility Model for Great Britain: a GIS Based Approach

The term debris flow refers to the rapid downslope flow of poorly-sorted debris mixed with water (Ballantyne, 2004). Debris flows are described by (Hungr et al., 2014) as: “very rapid to extremely rapid surging flow of saturated debris in a steep channel. Strong entrainment of material and water from the flow path”. They are a widespread phenomenon in mountainous terrain and are distinct from other types of landslides as they can occur periodically on established paths, usually gullies and first- or second-order drainage channels. Debris flows in Great Britain are most commonly found in upland Scotland but also in parts of Wales and the Lake District

An Index Theorem for Domain Walls in Supersymmetric Gauge Theories

The supersymmetric abelian Higgs model with N scalar fields admits multiple domain wall solutions. We perform a Callias-type index calculation to determine the number of zero modes of this soliton. We confirm that the most general domain wall has 2(N-1) zero modes, which can be interpreted as the positions and phases of (N-1) constituent domain walls. This implies the existence of moduli for a D-string interpolating between N D5-branes in IIB string theory.Comment: 9 pages, REVTeX4; v2: reference adde

Pregnancy After “a Choice to Drink”: Meanings of Autonomy in England's Policies on Fetal Alcohol Spectrum Disorder

There are few areas of social life where the paradox of autonomy is played out more continually than with pregnancy. This chapter considers meanings ascribed to autonomy through discussing an analysis of policy documents about fetal alcohol spectrum disorder (FASD) published by health authorities in England. These documents justify a suite of health interventions presented as necessary to prevent this disorder in those yet to be born and to address the health and care needs of those who may be diagnosed with FASD after birth. The prevention aspect of the policy framework and its concepts of autonomy in pregnancy are focused on. Context is provided through an account of scholarship detailing ways the “choice to drink” became compromised since the “discovery” of Fetal Alcohol syndrome (FAS) in the early 1970s. Conceptualizations of autonomy associated with what the chapter terms a “post-choice policy framework” are then detailed, with attention paid especially to what policies say about providing and collecting information. It is argued that concepts of autonomy are modified, as autonomy for pregnant women both appears and disappears as a consideration. Either way, autonomy is given a meaning that makes its existence contingent on professional influence, diminishing space for maternal judgement

SU(2) Calorons and Magnetic Monopoles

We investigate the self-dual Yang-Mills gauge configurations on $R^3\times S^1$ when the gauge symmetry SU(2) is broken to U(1) by the Wilson loop. We construct the explicit field configuration for a single instanton by the Nahm method and show that an instanton is composed of two self-dual monopoles of opposite magnetic charge. We normalize the moduli space metric of an instanton and study various limits of the field configuration and its moduli space metric.Comment: 17 pages, RevTex, 1 Figur

Orbital structure of the GJ876 extrasolar planetary system, based on the latest Keck and HARPS radial velocity data

We use full available array of radial velocity data, including recently published HARPS and Keck observatory sets, to characterize the orbital configuration of the planetary system orbiting GJ876. First, we propose and describe in detail a fast method to fit perturbed orbital configuration, based on the integration of the sensitivity equations inferred by the equations of the original $N$-body problem. Further, we find that it is unsatisfactory to treat the available radial velocity data for GJ876 in the traditional white noise model, because the actual noise appears autocorrelated (and demonstrates non-white frequency spectrum). The time scale of this correlation is about a few days, and the contribution of the correlated noise is about 2 m/s (i.e., similar to the level of internal errors in the Keck data). We propose a variation of the maximum-likelihood algorithm to estimate the orbital configuration of the system, taking into account the red noise effects. We show, in particular, that the non-zero orbital eccentricity of the innermost planet \emph{d}, obtained in previous studies, is likely a result of misinterpreted red noise in the data. In addition to offsets in some orbital parameters, the red noise also makes the fit uncertainties systematically underestimated (while they are treated in the traditional white noise model). Also, we show that the orbital eccentricity of the outermost planet is actually ill-determined, although bounded by $\sim 0.2$. Finally, we investigate possible orbital non-coplanarity of the system, and limit the mutual inclination between the planets \emph{b} and \emph{c} orbits by $5^\circ-15^\circ$, depending on the angular position of the mutual orbital nodes.Comment: 36 pages, 11 figures, 3 tables; Accepted to Celestial Mechanics and Dynamical Astronom

Calcium sensitivity and the Frank-Starling mechanism of the heart are increased in titin N2B region deficient mice

Previous work suggests that titin-based passive tension is a factor in the Frank-Starling mechanism of the heart, by increasing length-dependent activation (LDA) through an increase in calcium sensitivity at long sarcomere length. We tested this hypothesis in a mouse model (N2B KO model) in which titin-based passive tension is elevated as a result of the excision of the N2B element, one of cardiac titin's spring elements. LDA was assessed by measuring the active tension-pCa (-log[Ca2+]) relationship at sarcomere length (SLs) of 1.95, 2.10 and 2.30mum in WT and N2B KO skinned myocardium. LDA was positively correlated with titin-based passive tension, due to an increase in calcium sensitivity at the longer SLs in the KO. For example, at pCa 6.0 the KO:WT tension ratio was 1.28+/-0.07 and 1.42+/-0.04 at SLs of 2.1 and 2.3mum, respectively. There was no difference in protein expression or phosphorylation of sarcomeric proteins. We also measured the calcium sensitivity after PKA treating the skinned muscle and found that titin-based passive tension was also now correlated with LDA, with a slope that was significantly increased compared to no PKA treatment. Finally, we performed isolated heart experiments and measured the Frank-Starling relation (slope of developed wall stress-LV volume relation) as well as diastolic stiffness (slope of diastolic wall stress - volume relation). The FSM was more pronounced in the N2B KO hearts and the slope of the FSM correlated with diastolic stiffness. These findings support that titin-based passive tension triggers an increase in calcium sensitivity at long sarcomere length, thereby playing an important role in the Frank-Starling mechanism of the heart