Methods and code for 'classical' age-modelling of radiocarbon sequences.

Age–depth models form the backbone of most palaeoenvironmental studies. However, procedures for constructing chronologies vary between studies, they are usually not explained sufficiently, and some are inadequate for handling calibrated radiocarbon dates. An alternative method based on importance sampling through calibrated dates is proposed. Dedicated R code is presented which works with calibrated radiocarbon as well as other dates, and provides a simple, systematic, transparent, documented and customizable alternative. The code automatically produces age–depth models, enabling exploration of the impacts of different assumptions (e.g., model type, hiatuses, age offsets, outliers, and extrapolation).

Experimental investigation of flow and segregation behaviour of bulk solids in silos under high gravity conditions

Many researchers have investigated the flow and segregation behaviour in model scale experimental silos at normal gravity conditions. However it is known that the stresses experienced by the bulk solid in industrial silos are high when compared to model silos. Therefore it is important to understand the effect of stress level on flow and segregation behaviour and establish the scaling laws governing this behaviour. The objective of this paper is to understand the effect of gravity on the flow and segregation behaviour of bulk solids in a silo centrifuge model. The materials used were two mixtures composed of Polyamide and glass beads. The discharge of two bi-disperse bulk solids in a silo centrifuge model were recorded under accelerations ranging from 1g to 15g. The velocity distribution during discharge was evaluated using Particle Image Velocimetry (PIV) techniques and the concentration distribution of large and small particles were obtained by imaging processing techniques. The flow and segregation behaviour at high gravities were then quantified and compared with the empirical equations available in the literature.

'Not Forsworn with Pink Ribbons': Hannah More, Thomas De Quincey, and the Literature of Power

De Quincey's conception of the literature of "power" as opposed to that of "knowledge," has proved to be one of the most influential of romantic theories of literature, playing no small part in the canonization of Wordsworth. De Quincey's early acquaintance with the Lyrical Ballads was made through the Evangelical circles of his mother, who was a follower of Hannah More and a member of the Clapham sect. In later years, however, De Quincey repudiated his early Evangelical upbringing and wrote quite scathingly of the literary pretensions of Hannah More. This paper attempts to uncover the revisionary nature of De Quincey's later reminiscences of More and to indicate thereby the covert influence of Evangelical thinking on his literary theorizing. Far from absolving literature of politics, however, colonialist and nationalist imperatives typical of Evangelical thinking may be seen to operate within the spiritualized and aesthetic sphere to which literary power is arrogated by De Quincey.

Public religions and civil society: the case of London Methodism

Amendments to secularization theory have brought the issue of public religions to the fore in recent years. In particular, the work of Casanova and Beyer has maintained the importance of functional differentiation whilst pointing to the flow of religious discourses across social boundaries. These issues, however, have received little ethnographic attention, such that many of the problems associated with theories of differentiation and globalization have not been engaged in a sustained manner. Research within black majority London Methodist congregations is drawn upon to suggest ways in which these theories can be reconsidered. Three related issues are focused upon: the continued importance of the nation-state (including national stratifications); the importance of a practical approach to religion, such that discourses are understood as ‘practical discourses’; and the importance of not privileging religion by reifying it in functional terms. These considerations have ramifications not only for secularization theory, but the general field of the sociological study of religion.

Social Work in the Republic of Ireland: A History of the Present

This article reports on research carried out into the nature and position of social work in the child protection and welfare system in Ireland. Employing a methodology of a history of the present, this research sought to crtically examine the nature and position of social work within the social as a 'psy expert'. Selected findings relating to the genealogical and archaeological construction of social work discourse in Ireland are provided to illuminate how its particular historical pathways both enabled and constrained its development. It was found that, to some extent, conceptualizations of social work in the context of its space within the social were applicable to the Irish context. however, it was also found that a number of other factors were also significant, implying the need for problematization of existing theories of the social. Although some of the findings relate directly to the particular spatial context of Ireland, others are transferable to the UK and international contexts. The research asserts that, while social work represents a diffuse and complex activity, enabled and constrained by its genealogical context, the potential exists in the profesion for greater attention to be apid to its archaeoloigcal construction. In light of contemporary neo-liberal conditions of governance, the need for such attention is emphasized.

Role of calcium influx through voltage-operated calcium channels and of calcium mobilization in the physiology of Schistosoma mansoni muscle contractions

We tested the hypothesis that voltage-operated Ca2+ channels mediate an extracellular Ca2+ influx in muscle fibres from the human parasite Schistosoma mansoni and, along with Ca2+ mobilization from the sarcoplasmic reticulum, contribute to Muscle contraction. Indeed, whole-cell voltage clamp revealed voltage-gated inward currents carried by divalent ions with a peak current elicited by steps to + 20 mV (from a holding potential of -70 mV). Depolarization of the fibres by elevated extracellular K+ elicited contractions that were completely dependent on extracellular Ca2+ and inhibited by nicardipine (half inhibition at 4(.)1 mu M). However these contractions were not very sensitive to other classical blockers of voltage-gated Ca2+ channels, indicating that the schistosome Muscle channels have an atypical pharmacology when compared to their mammalian counterparts. Furthermore, the contraction induced by 5 mM caffeine was inhibited after depletion of the sarcoplasmic reticulum either with thapsigargin (10 mu M) or ryanodine (10 mu M). These data suggest that voltage-operated Ca2+ channels docontribute to S. mansoni contraction as does the mobilization of stored Ca2+, despite the small volume of sarcoplasmic reticulum in schistosome smooth muscles.

Once a Criminal, Always a Criminal?: ‘Redeemability’ and the Psychology of Punitive Public Attitudes

Several studies have sought to link punitive public attitudes to attribution style and/or lay theories of crime. This research finds that those who believe criminal acts are the result of freely chosen and willful behavior are more likely to be punitive than those who feel crime is the result of external circumstances and constraints. These analyses focus on only one dimension of attributions: locus of control (internal/external). In this analysis, we include a second dimension, thought to be a better predictor of attitudes in social psychological research: stability/instability. In addition to measuring lay theories of crime causation, we also test for “belief in redeemability” (or beliefs about the ability of deviants to change their ways). Our hypothesis is that this other dimension of personal attributions (stability/instability) may be as critical in explaining support for highly punitive criminal justice policies as beliefs about criminal responsibility. We find evidence supportive of this model in an analysis of data from postal survey of residents of six areas in England.

The Macroeconomic Factors Conditioning the Impact of Identity on Attitudes towards the EU

Factors relating to identity and to economics have been shown to be important predictors of attitudes towards the European Union (EU). In this article, we show that the impact of identity is conditional on economic context. First, living in a member state that receives relatively high levels of EU funding acts as a 'buffer', diluting the impact of an exclusive national identity on Euroscepticism. Second, living in a relatively wealthy member state, with its associated attractiveness for economic migrants, increases the salience of economic xenophobia as a driver of sceptical attitudes. These results highlight the importance of seeing theories of attitude formation (such as economic and identity theories) not as competitors but rather as complementary, with the predictive strength of one theoretical approach (identity) being a function of system-level variation in factors relating to the other theoretical approach (macro-level economic conditions).

The story of some: Everyday pragmatic inference by children and adults

The statement, some elephants have trunks, is logically true but pragmatically infelicitous. Whilst some is logically consistent with all, it is often pragmatically interpreted as precluding all. In Experiments 1 and 2, we show that with pragmatically impoverished materials, sensitivity to the pragmatic implicature associated with some is apparent earlier in development than has previously been found. Amongst 8-year-old children, we observed much greater sensitivity to the implicature in pragmatically enriched contexts. Finally, in Experiment 3, we found that amongst adults, logical responses to infelicitous some statements take longer to produce than do logical responses to felicitous some statements, and that working memory capacity predicts the tendency to give logical responses to the former kind of statement. These results suggest that some adults develop the ability to inhibit a pragmatic response in favour of a logical answer. We discuss the implications of these findings for theories of pragmatic inference.

Noise resilience and entanglement evolution in two nonequivalent classes of quantum algorithms

The speedup provided by quantum algorithms with respect to their classical counterparts is at the origin of scientific interest in quantum computation. However, the fundamental reasons for such a speedup are not yet completely understood and deserve further attention. In this context, the classical simulation of quantum algorithms is a useful tool that can help us in gaining insight. Starting from the study of general conditions for classical simulation, we highlight several important differences between two nonequivalent classes of quantum algorithms. We investigate their performance under realistic conditions by quantitatively studying their resilience with respect to static noise. This latter refers to errors affecting the initial preparation of the register used to run an algorithm. We also compare the evolution of the entanglement involved in the different computational processes.

Kinematics of the ring-like nebula SuWt 2

We present the first detailed spatio-kinematical analysis and modelling of the southern planetary nebula SuWt 2. This object presents a problem for current theories of planetary nebula formation and evolution, as it is not known to contain a central post-main-sequence star. Deep narrow-band [NII]6584Å images reveal the presence of faint bipolar lobes emanating from the edges of the nebular ring. Long-slit observations of the Ha and [NII]6584Å emission lines were obtained using the ESO (European Southern Observatory) Multi-Mode Instrument on the 3.6-m ESO New Technology Telescope. The spectra reveal the nebular morphology as a bright torus encircling the waist of an extended bipolar structure. By deprojection, the inclination of the ring is found to be 68° +/- 2° (cf. ~90° for the double A-type binary believed to lie at the centre of the nebula), and the ring expansion velocity is found to be 28 kms-1. Our findings are discussed with relation to possible formation scenarios for SuWt 2. Through comparison of the nebular heliocentric systemic velocity, found here to be -25 +/- 5km s-1, and the heliocentric systemic velocity of the double A-type binary, we conclude that neither component of the binary could have been the nebular progenitor. However, we are unable to rule out the presence of a third component to the system, which would have been the nebula progenitor.

Mid-infrared a-b plane response of YBa2Cu3O7-delta as a function of doping and temperature determined by attenuated total reflection

The mid-infrared optical response of c-axis thin films of YBa2Cu3O7-delta has been studied using Otto-configuration attenuated total reflectance. The measured reflectance-angle characteristics are dominated by a strong absorption feature due to the excitation of surface plasmons, and can be modeled to determine the a-b plane dielectric function. The results show that while epsilon(i,) and therefore sigma(r), are temperature independent, \epsilon(r)\ exhibits a moderate decrease with generalized Drude analysis shows that the plasma frequency is independent of temperature, but decreases with decreasing doping. The scattering rate increases with temperature, and also increases with decreasing doping, consistent with stronger coupling in the underdoped regime. The mass-enhancement is small but increases to 30-40% at delta = 0.6. Difficulties in reconciling the results with some current theories of high-T-c materials are discussed. Finally, the surface plasmon propagation lengths and penetration depths are shown to vary systematically with doping. (C) 2003 Elsevier B.V. All rights reserved.

Complete nonlinear theory of longitudinal-to-transverse dust lattice mode coupling in a single-layer dusty plasma crystal

A comprehensive nonlinear model is put forward for coupled longitudinal to transverse displacements in a horizontal dust mono-layer, levitated under the combined influence of gravity and an electric and/or magnetic sheath field. A set of coupled nonlinear evolution equations are obtained in a discrete description, and a pair of coupled (Boussinesq-like) PDEs are obtained in the continuum approximation. Finally, the amplitude modulation of the coupled modes is discussed, pointing out the importance of the coupling. All these results are generic, i.e. valid for any assumed form of the inter-grain interaction potential U and the sheath potential Phi.

The Doppler shadow of WASP-3b. A tomographic analysis of Rossiter-McLaughlin observations

Context. Hot-Jupiter planets must form at large separations from their host stars where the temperatures are cool enough for their cores to condense. They then migrate inwards to their current observed orbital separations. Different theories of how this migration occurs lead to varying distributions of orbital eccentricity and the alignment between the rotation axis of the star and the orbital axis of the planet. Aims: The spin-orbit alignment of a transiting system is revealed via the Rossiter-McLaughlin effect, which is the anomaly present in the radial velocity measurements of the rotating star during transit due to the planet blocking some of the starlight. In this paper we aim to measure the spin-orbit alignment of the WASP-3 system via a new way of analysing the Rossiter-McLaughlin observations. Methods: We apply a new tomographic method for analysing the time variable asymmetry of stellar line profiles caused by the Rossiter-McLaughlin effect. This new method eliminates the systematic error inherent in previous methods used to analyse the effect. Results: We find a value for the projected stellar spin rate of v sin i = 13.9 ± 0.03 km s-1 which is in agreement with previous measurements but has a much higher precision. The system is found to be well aligned, with ? = 5-5+6° which favours an evolutionary history for WASP-3b involving migration through tidal interactions with a protoplanetary disc. From comparison with isochrones we put an upper limit on the age of the star of 2 Gyr.