Detailing the phonetic environment: a sociophonetic study of the London-Bengali community

The present study investigated variability in the production of English by London Bengali adults who speak the Sylheti dialect of Bengali. Speakers had been resident in London for differing lengths of time. They were recorded producing /l/, /r/ and the eleven monophthongal vowels in English. Phonetically trained listeners rated speakers' productions of /l/ and /r/ in terms of manner and place. F1 and F2 formant frequency values, and duration were measured for all monophthongal vowels. The results demonstrated that older speakers (first-generation immigrants) tended to use Sylhetilike variants when speaking English, whilst second-generation speakers tended to use native English-like variants. These findings will be used to inform studies of the role of phonetic input in child language acquisition from the London Bengali community

Online molecular characterisation of organic aerosols in an atmospheric chamber using extractive electrospray ionisation mass spectrometry

Abstract. The oxidation of biogenic volatile organic compounds (VOCs) represents a substantial source of secondary organic aerosol (SOA) in the atmosphere. In this study, we present online measurements of the molecular constituents formed in the gas and aerosol phases during α-pinene oxidation in the Cambridge Atmospheric Simulation Chamber (CASC). We focus on characterising the performance of extractive electrospray ionisation (EESI) mass spectrometry (MS) for particle analysis. A number of new aspects of EESI-MS performance are considered here. We show that relative quantification of organic analytes can be achieved in mixed organic–inorganic particles. A comprehensive assignment of mass spectra for α-pinene derived SOA in both positive and negative ion modes is obtained using an ultra-high-resolution mass spectrometer. We compare these online spectra to conventional offline ESI-MS spectra and find good agreement in terms of the compounds identified, without the need for complex sample work-up procedures. Under our experimental conditions, EESI-MS signals arise only from particle-phase analytes. High-time-resolution (7 min) EESI-MS spectra are compared with simulations from the near-explicit Master Chemical Mechanism (MCM) for a range of reaction conditions. We show that MS peak abundances scale with modelled concentrations for condensable products (pinonic acid, pinic acid, OH-pinonic acid). Relative quantification is achieved throughout SOA formation as the composition, size and mass (5–2400 µg m−3) of particles is evolving. This work provides a robust demonstration of the advantages of EESI-MS for chamber studies over offline ESI-MS (time resolution, relative quantification) and over hard online techniques (molecular information). </jats:p

Highest weight Macdonald and Jack Polynomials

Fractional quantum Hall states of particles in the lowest Landau levels are described by multivariate polynomials. The incompressible liquid states when described on a sphere are fully invariant under the rotation group. Excited quasiparticle/quasihole states are member of multiplets under the rotation group and generically there is a nontrivial highest weight member of the multiplet from which all states can be constructed. Some of the trial states proposed in the literature belong to classical families of symmetric polynomials. In this paper we study Macdonald and Jack polynomials that are highest weight states. For Macdonald polynomials it is a (q,t)-deformation of the raising angular momentum operator that defines the highest weight condition. By specialization of the parameters we obtain a classification of the highest weight Jack polynomials. Our results are valid in the case of staircase and rectangular partition indexing the polynomials.Comment: 17 pages, published versio

Quantifying the stratigraphic completeness of delta shoreline trajectories

Understanding the incomplete nature of the stratigraphic record is fundamental for interpreting stratigraphic sequences. Methods for quantifying stratigraphic completeness for one-dimensional stratigraphic columns, defined as the proportion of time intervals of some length that contain stratigraphy, are commonplace; however, quantitative assessments of completeness in higher dimensions are lacking. Here we present a metric for defining stratigraphic completeness of two-dimensional shoreline trajectories using topset-foreset rollover positions in dip-parallel sections and describe the preservation potential of a shoreline trajectory derived from the geometry of the delta surface profile and the kinematics of the geomorphic shoreline trajectory. Two end-member forward models are required to fully constrain the preservation potential of the shoreline dependent on whether or not a topset is eroded during base level fall. A laboratory fan-delta was constructed under nonsteady boundary conditions, and one-dimensional stratigraphic column and two-dimensional shoreline completeness curves were calculated. Results are consistent with the hypothesis derived from conservation of sediment mass that completeness over all timescales should increase given increasing dimensions of analysis. Stratigraphic trajectories and completeness curves determined from forward models using experimental geomorphic trajectories compare well to values from transects when subsampled to the equivalent stratigraphic resolution as observed in the actual preserved sequence. The concept of stratigraphic completeness applied to two-dimensional trajectory analysis and the end-member forward models presented here provide novel tools for a conceptual understanding of the nature of stratigraphic preservation at basin scales

Strategies for Developing Sustainable Design Practice for Students and SME Professionals

Designers and engineers seem finally to be awakening to the challenge that sustainable development has given. Educators and students alike are keenly aware of the need to become more effective in the training and practice of their specific disciplines with respect to sustainability. \noindent In the past four years since this research has developed, there has been a marked change in the mass market appeal for sustainable products and services. Implementation of sustainable design practice from both recent graduates and also innovative small and medium enterprises (SMEs) at a local level is slow. One would assume that the consumer drive would push a change in design practice but perhaps the complexities of sustainable design along with the lack of experience in the field are providing barriers to designers and marketers alike. In addition the SME sector alone makes up the bulk of industry within the European Union (EU) varying in some countries from 80-95% of the total numbers of companies (Tukker et al. 2000). These industries by their nature find it difficult to dedicate expertise solely to sustainable development issues. The strategy outlined in this paper intended to introduce concepts of sustainable design thinking and practice to both SMEs and undergraduate students. \noindent This current and ongoing research qualitatively assesses appropriate models for educating for sustainable design thinking with SME employees and undergraduate design students. The sample groups include Industrial Design and Product Design undergraduate students in Ireland at the Institute of Technology, Carlow (IT Carlow), The University of Limerick (UL) and a sample of SMEs in the South East of Ireland, with broad national participation from other students of design and professionals from industry. Current levels of understanding of students and SME professionals of key environmental and social issues are measured

Learning intrinsic excitability in medium spiny neurons

We present an unsupervised, local activation-dependent learning rule for intrinsic plasticity (IP) which affects the composition of ion channel conductances for single neurons in a use-dependent way. We use a single-compartment conductance-based model for medium spiny striatal neurons in order to show the effects of parametrization of individual ion channels on the neuronal activation function. We show that parameter changes within the physiological ranges are sufficient to create an ensemble of neurons with significantly different activation functions. We emphasize that the effects of intrinsic neuronal variability on spiking behavior require a distributed mode of synaptic input and can be eliminated by strongly correlated input. We show how variability and adaptivity in ion channel conductances can be utilized to store patterns without an additional contribution by synaptic plasticity (SP). The adaptation of the spike response may result in either "positive" or "negative" pattern learning. However, read-out of stored information depends on a distributed pattern of synaptic activity to let intrinsic variability determine spike response. We briefly discuss the implications of this conditional memory on learning and addiction.Comment: 20 pages, 8 figure