Evaluation of a boundary integral representation for the conformal mapping of the unit disk onto a simply-connected domain

A representation of the conformal mapping g of the interior or exterior of the unit circle onto a simply-connected domain Ω as a boundary integral in terms ofƒ|∂Ω is obtained, whereƒ :=g -l. A product integration scheme for the approximation of the boundary integral is described and analysed. An ill-conditioning problem related to the domain geometry is discussed. Numerical examples confirm the conclusions of this discussion and support the analysis of the quadrature scheme.

Wind gust estimation for Mid-European winter storms: towards a probabilistic view

Three wind gust estimation (WGE) methods implemented in the numerical weather prediction (NWP) model COSMO-CLM are evaluated with respect to their forecast quality using skill scores. Two methods estimate gusts locally from mean wind speed and the turbulence state of the atmosphere, while the third one considers the mixing-down of high momentum within the planetary boundary layer (WGE Brasseur). One hundred and fifty-eight windstorms from the last four decades are simulated and results are compared with gust observations at 37 stations in Germany. Skill scores reveal that the local WGE methods show an overall better behaviour, whilst WGE Brasseur performs less well except for mountain regions. The here introduced WGE turbulent kinetic energy (TKE) permits a probabilistic interpretation using statistical characteristics of gusts at observational sites for an assessment of uncertainty. The WGE TKE formulation has the advantage of a ‘native’ interpretation of wind gusts as result of local appearance of TKE. The inclusion of a probabilistic WGE TKE approach in NWP models has, thus, several advantages over other methods, as it has the potential for an estimation of uncertainties of gusts at observational sites.

Synoptic-scale controls of persistent low temperature and icy weather over southern China in January 2008

In January 2008, central and southern China experienced persistent low temperatures, freezing rain, and snow. The large-scale conditions associated with the occurrence and development of these snowstorms are examined in order to identify the key synoptic controls leading to this event. Three main factors are identified: 1) the persistent blocking high over Siberia, which remained quasi-stationary around 65°E for 3 weeks, led to advection of dry and cold Siberian air down to central and southern China; 2) a strong persistent southwesterly flow associated with the western Pacific subtropical high led to enhanced moisture advection from the Bay of Bengal into central and southern China; and 3) the deep inversion layer in the lower troposphere associated with the extended snow cover over most of central and southern China. The combination of these three factors is likely responsible for the unusual severity of the event, and hence a long return period

A spectral view of nonlinear fluxes and stationary-transient interaction in the atmosphere

Nonlinear spectral transfers of kinetic energy and enstrophy, and stationary-transient interaction, are studied using global FGGE data for January 1979. It is found that the spectral transfers arise primarily from a combination, in roughly equal measure, of pure transient and mixed stationary-transient interactions. The pure transient interactions are associated with a transient eddy field which is approximately locally homogeneous and isotropic, and they appear to be consistently understood within the context of two-dimensional homogeneous turbulence. Theory based on spatial wale separation concepts suggests that the mixed interactions may be understood physically, to a first approximation, as a process of shear-induced spectral transfer of transient enstrophy along lines of constant zonal wavenumber. This essentially conservative enstrophy transfer generally involves highly nonlocal stationary-transient energy conversions. The observational analysis demonstrates that the shear-induced transient enstrophy transfer is mainly associated with intermediate-scale (zonal wavenumber m > 3) transients and is primarily to smaller (meridional) scales, so that the transient flow acts as a source of stationary energy. In quantitative terms, this transient-eddy rectification corresponds to a forcing timescale in the stationary energy budget which is of the same order of magnitude as most estimates of the damping timescale in simple stationary-wave models (5 to 15 days). Moreover, the nonlinear interactions involved are highly nonlocal and cover a wide range of transient scales of motion.

'Eden Cinema' by Marguerite Duras

Duras’s theatre work has been profoundly neglected by UK theatre academics and practitioners, and Eden Cinema has almost no performance history in Britain. My project asked three interconnected research questions: how developing the performance contributes to understanding Duras’s theatre and specifically Eden Cinema’s problems of performability; how multimedia performance emphasising mediated sound and the live body reconfigures memory, autobiography, storytelling, gender and racial identity; how to locate a performance style appropriate for Durasian narratives of displacement and death which reflect the discontinuous and mutable form of Duras’s ‘texte/film/théâtre’. Drawing on my research interests in gender, post-colonial hybridity and performed deconstruction, I focused my staging decisions on the discontinuities and ambivalences of the text. I addressed performability by avoiding the temptation to resolve the strange ellipses in the text and instead evoked the text’s imperfect and fragmented memories, and its uncertain spatial and temporal locations, by means of a fluid theatrical form. The mise-en-scène represented imagined and remembered spaces simultaneously, and co-existing historical moments. The performance style counterpointed live and mediated action and audio-visual forms. A complex through-composed soundscape, comprising voice-over, sound and music, became a key means for evoking overlapping temporalities, interconnected narratives and fragmented memories that were dispersed across the performance. The disempowerment of the mother figure and the silent indigenous servant in the text was demonstrated through their spatial centrality but physical stillness. The servant’s colonial subaltern identity was paralleled and linked with the mother’s disenfranchisement through their proxemic relationships. I elicited a performance style which evoked ‘characters’, whose being was deferred across different regimes of reality and who ‘haunted’ the stage rather than inhabited it. I developed the project further in the additional written outcomes and presentations, and the subsequent performance of Savannah Bay where problems of performability intensify until embodiment is almost erased except via voice.

Typography for children with reading difficulties: preferences for type in reading books

For children with developmental dyslexia the already challenging task of learning to read is made harder by difficulties with phonological processing and perceptual distortions. As a result, these children may be less motivated to practise their literacy skills. This is problematic in that literacy can only be gained through constant and continued exposure to reading scenarios, and children who are unmotivated to practise are unlikely to develop into fluent readers. Children are active in choosing the books they read and it is therefore important to understand how the typography in those books influences their choice. Research with typically developing children has shown that they have clear opinions about the typography in their reading materials and that these opinions are likely to influence their motivation to read particular books. However, it cannot be assumed that children with reading difficulties read and respond to texts in the same way as children who do not struggle. Through case-studies of three children with reading difficulties, preferences for the typography in their reading books is examined. Looking at elements of typesetting such as spacing and size shows that this group of children is aware of differences in typography and that they have preferences for how their reading books are typeset. These children showed a preference for books that resembled those that their peers are reading rather than those that would, by typographic convention, be considered easier to read. This study is part of ongoing research into the development of alternative materials for teaching literacy skills to children with dyslexia.

Stephen Martin Leake: a Victorian's view of the Common Law

This article considers the life and work of Stephen Martin Leake and seeks to locate his work within the wider context of the procedural and substantive transformation of the mid-to-late Victorian legal world. In particular, the article attempts to rescue Leake from obscurity and emphasise his importance in this process. It is argued that Leake’s work began the process whereby common lawyers conceived of their law as organised in a principled rather than procedural manner. Later common law jurists built upon this work. Consideration is also given to the philosophical and jurisprudential sources upon which Leake drew in constructing his treatises.

Reading the world through words: cultural themes in heritage Chinese language textbooks

This paper explores the social and cultural knowledge embedded in the textbooks for language and literacy education in a Chinese heritage language school, the Zhonguo School, in Montreal, Quebec, Canada. It examines how Chinese language arts textbooks introduce the child reader to cultural knowledge considered legitimate and valued in China as well as in Chinese diasporan communities. Furthermore, it looks at the construction of cultural knowledge in Chinese language textbooks in relation to the mainstream ideology to which immigrant children are exposed in and out of mainstream school classrooms. It looks at how the power relationship between legitimate cultural knowledge in majority and minority contexts is established and to what extent it affects language minority students' literacy practices in mainstream school and heritage language school contexts. Data sources are the Chinese textbooks used from kindergarten to Grade 5 in a Chinese heritage language school.

Do phytoplankton communities evolve through a self-regulatory abundance-diversity relationship?

A small group of phytoplankton species that produce toxic or allelopathic chemicals has a significant effect on plankton dynamics in marine ecosystems. The species of non-toxic phytoplankton, which are large in number, are affected by the toxin-allelopathy of those species. By analysis of the abundance data of marine phytoplankton collected from the North-West coast of the Bay of Bengal, an empirical relationship between the abundance of the potential toxin-producing species and the species diversity of the non-toxic phytoplankton is formulated. A change-point analysis demonstrates that the diversity of non-toxic phytoplankton increases with the increase of toxic species up to a certain level. However, for a massive increase of the toxin-producing species the diversity of phytoplankton at species level reduces gradually. Following the results, a deterministic relationship between the abundance of toxic phytoplankton and the diversity of non-toxic phytoplankton is developed. The abundance–diversity relationship develops a unimodal pathway through which the abundance of toxic species regulates the diversity of phytoplankton. These results contribute to the current understanding of the coexistence and biodiversity of phytoplankton, the top-down vs. bottom-up debate, and to that of abundance–diversity relationship in marine ecosystems.

3D cloud reconstructions: evaluation of scanning radar scan strategy with a view to surface shortwave radiation closure

The ability of six scanning cloud radar scan strategies to reconstruct cumulus cloud fields for radiation study is assessed. Utilizing snapshots of clean and polluted cloud fields from large eddy simulations, an analysis is undertaken of error in both the liquid water path and monochromatic downwelling surface irradiance at 870 nm of the reconstructed cloud fields. Error introduced by radar sensitivity, choice of radar scan strategy, retrieval of liquid water content (LWC), and reconstruction scheme is explored. Given an in␣nitely sensitive radar and perfect LWC retrieval, domain average surface irradiance biases are typically less than 3 W m␣2 ␣m␣1, corresponding to 5–10% of the cloud radiative effect (CRE). However, when using a realistic radar sensitivity of ␣37.5 dBZ at 1 km, optically thin areas and edges of clouds are dif␣cult to detect due to their low radar re-ectivity; in clean conditions, overestimates are of order 10 W m␣2 ␣m␣1 (~20% of the CRE), but in polluted conditions, where the droplets are smaller, this increases to 10–26 W m␣2 ␣m␣1 (~40–100% of the CRE). Drizzle drops are also problematic; if treated as cloud droplets, reconstructions are poor, leading to large underestimates of 20–46 W m␣2 ␣m␣1 in domain average surface irradiance (~40–80% of the CRE). Nevertheless, a synergistic retrieval approach combining the detailed cloud structure obtained from scanning radar with the droplet-size information and location of cloud base gained from other instruments would potentially make accurate solar radiative transfer calculations in broken cloud possible for the first time.

Modelling human visual navigation using multi-view scene reconstruction

It is often assumed that humans generate a 3D reconstruction of the environment, either in egocentric or world-based coordinates, but the steps involved are unknown. Here, we propose two reconstruction-based models, evaluated using data from two tasks in immersive virtual reality. We model the observer’s prediction of landmark location based on standard photogrammetric methods and then combine location predictions to compute likelihood maps of navigation behaviour. In one model, each scene point is treated independently in the reconstruction; in the other, the pertinent variable is the spatial relationship between pairs of points. Participants viewed a simple environment from one location, were transported (virtually) to another part of the scene and were asked to navigate back. Error distributions varied substantially with changes in scene layout; we compared these directly with the likelihood maps to quantify the success of the models. We also measured error distributions when participants manipulated the location of a landmark to match the preceding interval, providing a direct test of the landmark-location stage of the navigation models. Models such as this, which start with scenes and end with a probabilistic prediction of behaviour, are likely to be increasingly useful for understanding 3D vision.

Resting state cortico-thalamic-striatal connectivity predicts pesponse to dorsomedial prefrontal rTMS in major depressive disorder

Despite its high toll on society, there has been little recent improvement in treatment efficacy for Major Depressive Disorder (MDD). The identification of biological markers of successful treatment response may allow for more personalized and effective treatment. Here we investigate whether resting state functional connectivity predicted response to treatment with rapid transcranial magnetic stimulation (rTMS) to dorsomedial prefrontal cortex (dmPFC). Twenty five individuals with treatment-refractory MDD underwent a 4-week course of dmPFC-rTMS. Before and after treatment, subjects received resting state functional MRI scans and assessments of depressive symptoms using the Hamilton Depresssion Rating Scale (HAMD17). We found that higher baseline cortico-cortical connectivity (dmPFC-subgenual cingulate and subgenual cingulate to dorsolateral PFC) and lower cortico-thalamic, cortico-striatal and cortico-limbic connectivity were associated with better treatment outcomes. We also investigated how changes in connectivity over the course of treatment related to improvements in HAMD17 scores. We found that successful treatment was associated with increased dmPFC-thalamic connectivity and decreased sgACC-caudate connectivity, Our findings provide insight into which individuals might respond to rTMS treatment and the mechanisms through which these treatments work.