Brood sow management

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A Hybrid Gyrokinetic Ion and Isothermal Electron Fluid Code for Astrophysical Plasma

This paper describes a new code for simulating astrophysical plasmas that solves a hybrid model composed of gyrokinetic ions (GKI) and an isothermal electron fluid (ITEF) [A. Schekochihin et al., Astrophys. J. Suppl. \textbf{182}, 310 (2009)]. This model captures ion kinetic effects that are important near the ion gyro-radius scale while electron kinetic effects are ordered out by an electron-ion mass ratio expansion. The code is developed by incorporating the ITEF approximation into {\tt AstroGK}, an Eulerian $\delta f$ gyrokinetics code specialized to a slab geometry [R. Numata et al., J. Compute. Pays. \textbf{229}, 9347 (2010)]. The new code treats the linear terms in the ITEF equations implicitly while the nonlinear terms are treated explicitly. We show linear and nonlinear benchmark tests to prove the validity and applicability of the simulation code. Since the fast electron timescale is eliminated by the mass ratio expansion, the Courant--Friedrichs--Lewy condition is much less restrictive than in full gyrokinetic codes; the present hybrid code runs $\sim 2\sqrt{m_\mathrm{i}/m_\mathrm{e}} \sim 100$ times faster than {\tt AstroGK}\ with a single ion species and kinetic electrons where $m_\mathrm{i}/m_\mathrm{e}$ is the ion-electron mass ratio. The improvement of the computational time makes it feasible to execute ion scale gyrokinetic simulations with a high velocity space resolution and to run multiple simulations to determine the dependence of turbulent dynamics on parameters such as electron--ion temperature ratio and plasma beta

Police powers and human rights in the context of terrorism

Purpose – The object of the paper is to analyse the justifications for the modification of police powers in response to terrorist threats, placing this issue in a European context. Design/methodology/approach – The paper consists of a critical examination of provisions relating to terrorism emanating from the European Union and the Council of Europe (European Convention on Human Rights (ECHR)), and the relevant English law on police powers of stop and search, arrest, and detention. Findings – Nothing in European law requires the amendments to police powers contained in English law; European law requires respect for human rights, even in dealing with terrorism; a shoot-to-kill policy is prohibited by the ECHR; and balance is an unsatisfactory method of resolving conflicts in this area. Research limitations/implications – The research was limited in its scope to certain areas of police powers, and to certain fundamental European documents. Future research should consider the issue in relation to wider areas. Originality/value – It challenges the idea of balance between liberty and security, proposing a test based on necessity instead

Volitional control of anticipatory ocular smooth pursuit after viewing, but not pursuing, a moving target: evidence for a re-afferent velocity store

Although human subjects cannot normally initiate smooth eye movements in the absence of a moving target, previous experiments have established that such movements can be evoked if the subject is required to pursue a regularly repeated, transient target motion stimulus. We sought to determine whether active pursuit was necessary to evoke such an anticipatory response or whether it could be induced after merely viewing the target motion. Subjects were presented with a succession of ramp target motion stimuli of identical velocity and alternating direction in the horizontal axis. In initial experiments, the target was exposed for only 120 ms as it passed through centre, with a constant interval between presentations. Ramp velocity was varied from +/- 9 to 45 degrees/s in one set of trials; the interval between ramp presentations was varied from 640 to 1920 ms in another. Subjects were instructed either to pursue the moving target from the first presentation or to hold fixation on another, stationary target during the first one, two or three presentations of the moving display. Without fixation, the first smooth movement was initiated with a mean latency of 95 ms after target onset, but with repeated presentations anticipatory smooth movements started to build up before target onset. In contrast, when the subjects fixated the stationary target for three presentations of the moving target, the first movement they made was already anticipatory and had a peak velocity that was significantly greater than that of the first response without prior fixation. The conditions of experiment 1 were repeated in experiment 3 with a longer duration of target exposure (480 ms), to allow higher eye velocities to build up. Again, after three prior fixations, the anticipatory velocity measured at 100 ms after target onset (when visual feedback would be expected to start) was not significantly different to that evoked after the subjects had made three active pursuit responses to the same target motion, reaching a mean of 20 degrees/s for a 50 degrees/s target movement. In a further experiment, we determined whether subjects could use stored information from prior active pursuit to generate anticipatory pursuit in darkness if there was a high expectancy that the target would reappear with identical velocity. Subjects made one predictive response immediately after target disappearance, but very little response thereafter until the time at which they expected the target to reappear, when they were again able to re-vitalize the anticipatory response before target appearance. The findings of these experiments provide evidence that information related to target velocity can be stored and used to generate future anticipatory responses even in the absence of eye movement. This suggests that information for storage is probably derived from a common pre-motor drive signal that is inhibited during fixation, rather than an efference copy of eye movement itself. Furthermore, a high level of expectancy of target appearance can facilitate the release of this stored information in darkness

Self-calibrating threshold detector

A self calibrating threshold detector comprises a single demodulating channel which includes a mixer having one input receiving the incoming signal and another input receiving a local replica code. During a short time interval, an incorrect local code is applied to the mixer to incorrectly demodulate the incoming signal and to provide a reference level that calibrates the noise propagating through the channel. A sample and hold circuit is coupled to the channel for storing a sample of the reference level. During a relatively long time interval, the correct replica code provides an output level which ranges between the reference level and a maximum level that represents incoming signal presence and synchronism with the replica code. A summer substracts the stored sample reference from the output level to provide a resultant difference signal indicative of the acquisition of the expected signal

Providing the family-nurse partnership programme through interpreters in England

This study looks at the delivery of the Family-Nurse Partnership (FNP) in England with interpreters. This home-visiting programme for vulnerable, young first-time mothers is known in the USA as the Nurse-Family Partnership (NFP). FNP is manualised with a number of fidelity targets and stretch objectives. This study covers the first two phases, pregnancy and infancy (up to 12 months). The programme relies on the development of a close nurse-client relationship. Interpreters can be a barrier for therapeutic work with vulnerable groups. The aims are to determine from quantitative and qualitative data whether the FNP programme can be delivered with fidelity in the presence of an interpreter and to explore issues concerned with the impact of interpreters on relationships. Statistical comparisons were made of delivery objectives over 2 years, from April 2007 to February 2009, in the 10 sites in England, spread across all nine Government Office Regions providing FNP. Forty-three clients had an interpreter at some point and 1261 did not. Qualitative interviews were conducted between April and May 2009 with 30 stakeholders (nurses, clients, interpreters). In relation to quantitative indicators, the percentage of planned content covered in visits was lower with interpreters (pregnancy 90% vs. 94%; infancy 88% vs. 93%) and both understanding and involvement of clients, as judged by nurses on 5-point scales, were lower (understanding, pregnancy 4.3 vs. 4.6, infancy 3.8 vs. 4.5; involvement, pregnancy 4.4 vs. 4.7, infancy 3.7 vs. 4.5). The interpreter was not thought by nurses to impede the development of a collaborative client-nurse relationship unless the interpreter and client became too close, but some nurses and clients reported that they would rather manage without an interpreter. Some stress was noted for nurses delivering the programme with an interpreter. More research is needed to determine the extent to which interpreters accurately convey the programme's strength-based approach