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The benefi ts of particle size reduction and mechanical densifi cation of biomass feedstock for storage, transportation, and handling must be assessed in relation to the systemic costs and energy consumption incurred due to these operations. The goal of this work was to determine the optimal levels of size reduction and densifi cation through a combination of modeling and experimen- tal studies. Size reduction and densifi cation data for Miscanthus and switchgrass were generated using a two-stage grinding process and the energy requirement and bulk densities for the particle sizes between 1 mm and 25.4 mm were determined. Increase in bulk density through compression by a pressure of 1.2 MPa was also measured. These data were used within BioFeed, a system-level optimization model, to simulate scenarios capturing the possibilities of performing size reduction and densifi cation at various stages of the supply chain. Simulation results assuming size reduction at farms showed that the optimal particle size range for both Miscanthus and switchgrass was 4-6 mm, with the optimal costs of $54.65 Mg -1 and $60.77 Mg -1 for Miscanthus and switchgrass, respectively. Higher hammer mill throughput and lower storage costs strongly impacted the total costs for different particle sizes. Size reduction and densifi cation of biomass at the county-specifi c centralized storage and pre-processing facilities could reduce the costs by as much as $6.34 Mg -1 for Miscanthus and $20.13 Mg -1 for switchgrass over the base case. These differences provided the upper bound on the investments that could be made to set-up and operate such systems. © 2014 Society of Chemical Industry and John Wiley & Sons, Ltd Supporting information may be found in the online version of this article.

To ensure effective biomass feedstock provision for large-scale ethanol production, a three-stage supply chain was proposed to include biomass supply sites, centralized storage and pre-processing (CSP) sites, and biorefinery sites. A GIS-enabled biomass supply chain optimization model (BioScope) was developed to minimize annual biomass-ethanol production costs by selectingthe optimal numbers, locations, and capacities of farms, CSPs, and biorefineries as well as identifying the optimal biomass flow pattern from farms to biorefineries. The model was implemented to study the Miscanthus-ethanol supply chain in Illinois. The results of the baseline case, assuming 2% of cropland is allocated for Miscanthus production, showed that unit Miscanthus-ethanol production costs were $220.6 Mg1, or $0.74 L1. Biorefinery-related costs are the largest cost component, accounting for 48% of the total costs, followed by biomass procurement, transportation, and CSP related costs. The unit Miscanthus-ethanol production costs could be reduced to $198 Mg1 using 20% of cropland, primarily due to savings in transportation costs. Sensitivity analyses showed that the optimal supply chain configurations, including the numbers and locations of supply sites, CSP facilities, and biorefineries, changed significantly for different cropland usage rates, biomass demands, transportation means, and pre-processing technologies. A supply chain composed of large biorefineries with the support of distributed CSP facilities was recommended to reduce biofuels production costs. Rail outperformed truck transportation to ship pre-processed biomass. Ground biomass with tapping is the suggested biomass format for the case study in Illinois, while high-density biomass formats are suggested for long distance transportation. (c) 2013 Society of Chemical Industry and John Wiley & Sons,Ltd

Research on bureaucracy and corruption tends to concentrate on cross-national research taking countries as the unit of analysis. Yet national-level measures neglect large differences within countries. This paper therefore takes the perspective of individual bureaucrats. It studies how public officials’ experience with bureaucratic institutions affects corruption within their sphere of work. Based on a survey of central government officials in five post-communist states, the paper examines the impact of civil service laws, the quality of their implementation, merit recruitment and the politicization of appointments on rumors of kickbacks in respondents’ work organization. The analysis shows that merit recruitment is associated with less corruption, while politicization is associated with more corruption. In contrast, civil service laws matter only if they are properly implemented. The findings complement and qualify country-level research, providing micro-foundations of the relation between bureaucracy and corruption.

This paper investigates the radio resource management (RRM) issues in a heterogeneous macro-femto network. The objective of femto deployment is to improve coverage, capacity, and experienced quality of service of indoor users. The location and density of user-deployed femtos is not known a-priori. This makes interference management crucial. In particular, with co-channel allocation (to improve resource utilization efficiency), RRM becomes involved because of both cross-layer and co-layer interference. In this paper, we review the resource allocation strategies available in the literature for heterogeneous macro-femto network. Then, we propose a self-organized resource allocation (SO-RA) scheme for an orthogonal frequency division multiple access based macro-femto network to mitigate co-layer interference in the downlink transmission. We compare its performance with the existing schemes like Reuse-1, adaptive frequency reuse (AFR), and AFR with power control (one of our proposed modification to AFR approach) in terms of 10 percentile user throughput and fairness to femto users. The performance of AFR with power control scheme matches closely with Reuse-1, while the SO-RA scheme achieves improved throughput and fairness performance. SO-RA scheme ensures minimum throughput guarantee to all femto users and exhibits better performance than the existing state-of-the-art resource allocation schemes.Copyright (c) 2014 John Wiley & Sons, Ltd.

This paper examines how male Polish builders in London construct themselves relationally to English builders as they negotiate their place within the labour hierarchies of the building site and in the London labour market. This is based on semi-structured interviews and participant photographs taken by Polish migrants arriving in the aftermath of the European Union expansion in May 2004, and now working in building sites across London. These buildings sites are mundane elements of a global city which employ transnational labour, and where differences between Polish and English builders become significant discursive tools of survival in a competitive labour market. The paper illustrates how Polish workers mark themselves as “superior” to English builders through the versatility of their embodied skills, work ethic, artistic qualities, and finesse in their social interactions on the building site. This paper thus provides new ways of understanding the meanings of work and the complexity of identity politics within the spaces of low-paid manual work in a global city.

This paper seeks to explain two problems posed by the history of criminal law doctrine by situating them in the context of the political sociology of citizenship. First, the paper outlines the logical connection between the rise to doctrinal orthodoxy of the idea of the responsible subject and the contemporaneous emergence of universal political citizenship. Secondly, it argues that subjectivist orthodoxy in doctrine may be reconciled with the apparently antithetical forms of regulatory strict liability law within the terms of ‘modern democratic citizenship’ as the latter were conceptualised by T. H. Marshall. Finally, by means of a comparison with Alan Brudner's recent philosophical rationalisation of the modern criminal law, it proposes that situating the criminal law in its environment of citizenship will help us to understand better the tensions that underlie contemporary challenges to its doctrine.

Imaging flow cytometry is an emerging technology that combines the statistical power of flow cytometry with spatial and quantitative morphology of digital microscopy. It allows high-throughput imaging of cells with good spatial resolution, while they are in flow. This paper proposes a general framework for the processing/classification of cells imaged using imaging flow cytometer. Each cell is localized by finding an accurate cell contour. Then, features reflecting cell size, circularity and complexity are extracted for the classification using SVM. Unlike the conventional iterative, semi-automatic segmentation algorithms such as active contour, we propose a noniterative, fully automatic graph-based cell localization. In order to evaluate the performance of the proposed framework, we have successfully classified unstained label-free leukaemia cell-lines MOLT, K562 and HL60 from video streams captured using custom fabricated cost-effective microfluidics-based imaging flow cytometer. The proposed system is a significant development in the direction of building a cost-effective cell analysis platform that would facilitate affordable mass screening camps looking cellular morphology for disease diagnosis. Lay description In this article, we propose a novel framework for processing the raw data generated using microfluidics based imaging flow cytometers. Microfluidics microscopy or microfluidics based imaging flow cytometry (mIFC) is a recent microscopy paradigm, that combines the statistical power of flow cytometry with spatial and quantitative morphology of digital microscopy, which allows us imaging cells while they are in flow. In comparison to the conventional slide-based imaging systems, mIFC is a nascent technology enabling high throughput imaging of cells and is yet to take the form of a clinical diagnostic tool. The proposed framework process the raw data generated by the mIFC systems. The framework incorporates several steps: beginning from pre-processing of the raw video frames to enhance the contents of the cell, localising the cell by a novel, fully automatic, non-iterative graph based algorithm, extraction of different quantitative morphological parameters and subsequent classification of cells. In order to evaluate the performance of the proposed framework, we have successfully classified unstained label-free leukaemia cell-lines MOLT, K562 and HL60 from video streams captured using cost-effective microfluidics based imaging flow cytometer. The cell lines of HL60, K562 and MOLT were obtained from ATCC (American Type Culture Collection) and are separately cultured in the lab. Thus, each culture contains cells from its own category alone and thereby provides the ground truth. Each cell is localised by finding a closed cell contour by defining a directed, weighted graph from the Canny edge images of the cell such that the closed contour lies along the shortest weighted path surrounding the centroid of the cell from a starting point on a good curve segment to an immediate endpoint. Once the cell is localised, morphological features reflecting size, shape and complexity of the cells are extracted and used to develop a support vector machine based classification system. We could classify the cell-lines with good accuracy and the results were quite consistent across different cross validation experiments. We hope that imaging flow cytometers equipped with the proposed framework for image processing would enable cost-effective, automated and reliable disease screening in over-loaded facilities, which cannot afford to hire skilled personnel in large numbers. Such platforms would potentially facilitate screening camps in low income group countries; thereby transforming the current health care paradigms by enabling rapid, automated diagnosis for diseases like cancer.

In this paper, we present the modeling and local equilibrium controllability analysis of a spherical robot. The robot consists of a spherical shell that is internally actuated by a pendulum mechanism. The rolling motion of the sphere manifests itself as a nonholonomic constraint in the modeling. We derive the dynamic model of the system using Lagrangian reduction and the variational principle. We first compute the Lagrangian and identify the symmetry with respect to a group action. The system Lagrangian and the rolling constraint are invariant with respect to the group isotropy and hence permit a reduced dynamic formulation termed as the nonholonomic 'Euler-Poincare' equation with advected dynamics. Using Lie brackets and symmetric products of the potential and control vector fields, local configuration accessibility and local (fiber) equilibrium controllability are presented. Copyright (C) 2015 John Wiley & Sons, Ltd.

Effective phasor measurement unit (PMU) placement is a key to the implementation of efficient and economically feasible wide area measurement systems in modern power systems. This paper proposes a pragmatic approach for cost-effective stage-wise deployment of PMUs while considering realistic constraints. Inspired from a real world experience, the proposed approach optimally allocates PMU placement in a stage-wise manner. The proposed approach also considers large-scale wind integration for effective grid state monitoring of wind generation dynamics. The proposed approach is implemented on the Danish power system projected for the year 2040. Furthermore, practical experience learnt from an optimal PMU placement project aimed at PMU placement in the Danish power system is presented, which is expected to provide insight of practical challenges at ground level that could be considered by PMU placement software developers as well as for future research in this field. Copyright (C) 2016 John Wiley & Sons, Ltd.

In this paper, soft variable structure control of fractional order systems is proposed for achieving high regulation rates and short settling times. Using the appropriate fractional order Lyapunov approach, a controller based on continuous fractional switch are designed to achieve high control performance. Due to the alleviation of chattering phenomenon soft VSC that is proposed for fractional order systems are quite useful in future for the practical systems.

This paper presents the hardware realization and performance study of fractional inductors of order 0<

The paper presents a generalized understanding on the dynamics of the sliding variable for discrete time sliding mode control systems via a fresh approach involving several bands in the space of the sliding variable. Using this analysis, controller parameters can be obtained once the ultimate band is chosen. It is shown that on choosing the least ultimate band, the control becomes non-switching and Gao's reaching law becomes identical to Utkin's reaching law. On other occasions, the ultimate band obtained using this approach is clearly less than that obtained in previous works using Gao's reaching law. The analysis is presented for both state feedback and multirate output feedback cases.

The paper aims at decomposing income-related inequality in maternal health care utilisation in India using the Shapley value method. In India, the usage of maternal health care services remains low with highly uneven access across socio-economic groups. We analyse the income-related inequality in maternal health care utilisation and its determinants. The decomposition results show that the demand side variables, namely, economic status of household and education of parents, are important factors determining inequality in utilisation. Also, we find that availability of government health care facilities in village and implementation of Janani Suraksha Yojana in village do not reduce income-related inequality in utilisation. Copyright (c) 2014 John Wiley & Sons, Ltd.

In this paper, the dynamic behavior of two identical adjacent structures connected with viscous dampers is investigated under base acceleration. The base acceleration is modeled as harmonic excitation as well as stationary white-noise random process. Each adjacent structure is modeled as a two-degree-of-freedom system. The governing differential equations of motion of the coupled system are derived and solved for relative displacement and absolute acceleration responses. A parametric study is conducted to study the influence of important system parameters on the response behavior of damper connected structures. The important parameters considered are excitation frequency, mass ratio, and stiffness ratio of the structure. It is observed that the viscous damper is quite effective in controlling the dynamic response of identical connected structures. For a given coupled structure and excitation, it is found that there exists an optimum value of damping coefficient of damper for which the peak responses under harmonic excitation and the mean square response quantities under stationary white-noise excitation attain the minimum value. The close-form expressions for optimum parameter and corresponding response are derived for an undamped system. Finally, it is observed that the damping ratio of the connected structures does not have noticeable effects on the optimum damper damping. This implies that the proposed close-form expressions of undamped structures can be used for the damped connected structures as well. Copyright (c) 2013 John Wiley & Sons, Ltd.

Appropriate integration of subsystems results in an energy-efficient and cost-effective design of the overall system. In many industrial applications, heat transfer fluid (HTF) is used to supply required amount of heat to multiple heat demands from a single heat source. Appropriate integration of fired heater with a process leads to overall reduction in energy requirement as well as capital investment. In this paper, four methodologies are developed to integrate fired heater appropriately with a process. Firstly, a targeting methodology is proposed to determine the minimum HTF flow rate to supply heat from single heater to multiple heat demands. Secondly, a methodology to integrate radiant fired heater with a process through HTF is discussed. Thirdly, indirect integration of fired heater, incorporating energy recovery from flue gas through the air preheater, is developed. Finally, improvement of overall energy efficiency by utilizing process heat below pinch through air preheating is demonstrated. It is also illustrated that the number of fired heater can be reduced, and hence, the total cost of the system can also be reduced by indirect integration. (c) 2013 Curtin University of Technology and John Wiley & Sons, Ltd.

Aim The misuse and abuse of Enduring Powers of Attorney (EPAs) by attorneys, particularly in relation to financial decision-making, is a growing concern. This paper explores the opportunities to enhance accountability of attorneys at the time of the execution of the document in Queensland. Method A four stage multi-method design comprised a critical reference group; semi-structured interviews with 32 principals or potential principals, attorneys and witnesses; two focus groups with service providers and a state wide survey of 76 principals, attorneys and witnesses. Results Across all methods and user groups, understanding the role and obligations of the attorney in an EPA was consistently identified as problematic. Conclusions Promoting accountability and understanding can be addressed by greater attention to the role of the attorney in the forms/ guidelines and in the structure and witnessing of the forms, increased direction about record keeping and access to appropriate advice and support.

ARC and NHMRC funded authors may self-archive the author accepted version of their paper (authors manuscript) after a 12-month embargo period from publication in an open access institutional repository., BACKGROUND: Diabetic retinopathy (DR) is a blinding disease of increasing prevalence, caused by a complex interplay of genetic and environmental factors. Here we describe the patient recruitment methodology, case and control definitions, and clinical characteristics of a study sample to be used for genome-wide association (GWAS) analysis to detect genetic risk variants of DR. METHODS: 1669 participants with either type 1 (T1) or type 2 (T2) diabetes mellitus (DM) aged 18 to 95 years were recruited in Australian hospital clinics. Individuals with T2DM had disease duration of at least 5 years, and were taking oral hypoglycemic medication, and/or insulin therapy. Participants underwent ophthalmic examination. Medical history and biochemistry results were collected. Venous blood was obtained for genetic analysis. RESULTS: 683 diabetic cases (178 T1DM and 505 T2DM participants) with sight-threatening DR, defined as severe non-proliferative DR (NPDR), proliferative DR (PDR) or diabetic macular edema (DME) were included in this analysis. 812 individuals with DM but no DR or minimal NPDR were recruited as controls (191 with T1DM and 621 with T2DM). The presence of sight-threatening DR was significantly correlated with DM duration, hypertension, nephropathy, neuropathy, HbA1C and BMI. DME was associated with T2DM (p, This work was funded by a grant from the Ophthalmic Research Institute of Australia, and Project Grant #595918 from the National Health and Medical Research Council (NHMRC) of Australia. JEC is supported in part by a NHMRC Practitioner Fellowship and KPB by a Career Development Fellowship. Research conducted at Moorfields Eye Hospital was funded by the National Institute for Health Research (NIHR) Biomedical Research Centre at Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology.

Structural health monitoring of existing infrastructure is currently an active field of research, where elaborate experimental programs and advanced analytical methods are used in identifying the current state of health of critical structures. Change of static deflection as the indicator of damage is the simplest tool in a structural health monitoring scenario of bridges that is least exploited in damage identification strategies. In this paper, some simple and elegant equations based on loss of symmetry due to damage are derived and presented for identification of damage in a bridge girder modeled as a simply supported beam using changes in static deflections and dynamic parameters. A single contiguous and distributed damage, typical of reinforced or prestressed concrete structures, is assumed for the structure. The methodology is extended for a base-line-free as well as base-line-inclusive measurement. Measurement strategy involves application of loads only at two symmetric points one at a time and deflection measurements at those symmetric points as well as at the midspan of the beam. A laboratory-based experiment is used to validate the approach. Copyright (c) 2012 John Wiley & Sons, Ltd.

This paper presents an approach to model the expected impacts of climate change on irrigation water demand in a reservoir command area. A statistical downscaling model and an evapotranspiration model are used with a general circulation model (GCM) output to predict the anticipated change in the monthly irrigation water requirement of a crop. Specifically, we quantify the likely changes in irrigation water demands at a location in the command area, as a response to the projected changes in precipitation and evapotranspiration at that location. Statistical downscaling with a canonical correlation analysis is carried out to develop the future scenarios of meteorological variables (rainfall, relative humidity (RH), wind speed (U-2), radiation, maximum (Tmax) and minimum (Tmin) temperatures) starting with simulations provided by a GCM for a specified emission scenario. The medium resolution Model for Interdisciplinary Research on Climate GCM is used with the A1B scenario, to assess the likely changes in irrigation demands for paddy, sugarcane, permanent garden and semidry crops over the command area of Bhadra reservoir, India. Results from the downscaling model suggest that the monthly rainfall is likely to increase in the reservoir command area. RH, Tmax and Tmin are also projected to increase with small changes in U-2. Consequently, the reference evapotranspiration, modeled by the Penman-Monteith equation, is predicted to increase. The irrigation requirements are assessed on monthly scale at nine selected locations encompassing the Bhadra reservoir command area. The irrigation requirements are projected to increase, in most cases, suggesting that the effect of projected increase in rainfall on the irrigation demands is offset by the effect due to projected increase/change in other meteorological variables (viz., Tmax and Tmin, solar radiation, RH and U-2). The irrigation demand assessment study carried out at a river basin will be useful for future irrigation management systems. Copyright (c) 2012 John Wiley & Sons, Ltd.

In the present investigation, various kinds of textures were attained on the steel surfaces. Roughness of the textures was varied using different grits of emery papers or polishing powders. Pins made of pure Al, Al-4Mg alloy and pure Mg were then slid against prepared steel plate surfaces at various numbers of cycles using an inclined pin-on-plate sliding tester. Tests were conducted at a sliding velocity of 2mms(-1) in ambient conditions under both dry and lubricated conditions. Normal loads were increased up to 110N during the tests. The morphologies of the worn surfaces of the pins and the formation of transfer layer on the counter surfaces were observed using a scanning electron microscope. Surface roughness parameters of the plate were measured using an optical profilometer. In the experiments, it was observed that the coefficient of friction and formation of a transfer layer (under dry and lubricated conditions) only depended on surface texture during the first few sliding cycles. The steady-state variation in the coefficient of friction under both dry and lubrication conditions was attributed to the self-organisation of texture of the surfaces at the interface during sliding. Copyright (C) 2012 John Wiley & Sons, Ltd.

The Morse-Smale complex is a topological structure that captures the behavior of the gradient of a scalar function on a manifold. This paper discusses scalable techniques to compute the Morse-Smale complex of scalar functions defined on large three-dimensional structured grids. Computing the Morse-Smale complex of three-dimensional domains is challenging as compared to two-dimensional domains because of the non-trivial structure introduced by the two types of saddle criticalities. We present a parallel shared-memory algorithm to compute the Morse-Smale complex based on Forman's discrete Morse theory. The algorithm achieves scalability via synergistic use of the CPU and the GPU. We first prove that the discrete gradient on the domain can be computed independently for each cell and hence can be implemented on the GPU. Second, we describe a two-step graph traversal algorithm to compute the 1-saddle-2-saddle connections efficiently and in parallel on the CPU. Simultaneously, the extremasaddle connections are computed using a tree traversal algorithm on the GPU. © 2012 Wiley Periodicals, Inc.

The speed of price adjustment hypothesis suggests that some stocks tend to adjust faster to market wide information than others. This paper uses the speed of price adjustment hypothesis to identify firm level characteristics that determine the information assimilation pace of individual stocks in the Indian markets. The research sample consists of 64 stocks with yearly data for 10 years, a total of 640 firm-year observations. Panel data analysis was used to study the effects of firm specific characteristics upon the speed of adjustment proxy DELAY. It was found that parameters such as firm size, trading volume and turnover had a significant influence on information assimilation. Large firms, as well as those firms with high turnover and trading volume, assimilated the market wide news faster, when compared with others. Stocks with high firm value and share price volatility were also found to adjust to market information faster. Firms with higher financial leverage take a longer time for price adjustments. The stock price adjustments were found to be much slower during the world financial crisis period of 2008-2010. While firm size remains a significant feature even during the crisis period, the volume and value traded were not found to be influencing factors for stock price movements during this time. � 2012 Korean Securities Association.

Dielectrophoresis is an electrokinetics-based phenomenon that involves the motion of a particle due to interaction between its dipole moment and an applied nonuniform electric field. This technique is very effective in particle manipulation and separation. In this paper, we consider an energy optimal transfer of a particle in a dielectrophoretic system from one specified location to another desired location. The system is described by a set of ordinary differential equations with a quadratic term in the control variable (the control being the applied voltage on the electrodes which induces the electric field), making the system nonaffine. Copyright (c) 2011 John Wiley & Sons, Ltd.

The aim in this paper is to challenge the increasingly common view in the literature that the law on end-of-life decision making is in disarray and is in need of urgent reform. The argument is that this assessment of the law is based on assumptions about the relationship between the identity of the defendant and their conduct, and about the nature of causation, which, on examination, prove to be indefensible. A clarification of the relationship between causation and omissions is provided which proves that the current legal position does not need modification, at least on the grounds that are commonly advanced for the converse view. This paves the way for a clarification, in conclusion, of important conceptual and moral differences between withholding, refusing and withdrawing life-sustaining measures, on the one hand, and assisted suicide and euthanasia, on the other.

The double variable frequency pendulum isolator (DVFPI) is an adaptation of single variable frequency pendulum isolator (VFPI). The principle benefit of the DVFPI is its capacity to accommodate larger displacements compared to the VFPI of identical plan dimensions. Moreover, there is the capability to use sliding surfaces with varying isolator geometry and coefficients of friction of top and bottom sliding surfaces, giving the designer greater flexibility to optimize performance. This paper describes the mathematical modeling and force-displacement relationships of the DVFPI. Behavior of the DVFPI is studied by varying isolator geometry and coefficient of friction of the two sliding surfaces and criteria to optimize the performance of the DVFPI are proposed. Further, influences of the initial time period, the coefficient of friction and the frequency variation factors at the two sliding surfaces are investigated. The combined effect of change in the initial time period and the coefficient of friction on the seismic response of the DVFPI is also studied. It is observed that the best performance of the DVFPI can be achieved by designing it with different friction coefficient and different initial time period of the two sliding surfaces. Copyright (C) 2010 John Wiley & Sons, Ltd.

The message of this paper is that the global financial crisis that started in August 2007 provides another powerful and sufficient argument for the United Kingdom to join the EMU and adopt the euro as soon as technically possible. This new financial stability argument for UK membership in the EMU is separate from and in addition to the conventional optimal currency arguments for joining, which have also become more persuasive in the past few years.

The use of cultural defence has been much discussed in the American context and has figured as one of the areas of concern in feminist assessments of multiculturalism. This paper examined two categories of cases from the English courts, those where cultural context has been seen as significant in interpreting the actions of female defendants, and those where ‘culture’ is invoked to explain severe acts of violence against women. It argues that cultural arguments become available to female defendants mainly when they conform to stereotypical images of the subservient non-Western wife. They have not, on the whole, been successfully employed by male defendants to mitigate crimes against women, though there are troubling exceptions. The larger problem is that mainstream culture itself promotes a gendered understanding of agency and responsibility, as when it perceives men as understandably incensed by the sexual behaviour of their women, or women as less responsible for their actions because of the influence of men. The conclusion is that the uses and abuses of cultural defence highlight issues that have wider provenance, for it is when cultural arguments resonate with mainstream conventions that they have proved most effective.

The aim of this paper is to address the question: what impact do others' representations have on the construction of identity. A study of the social identities of teenagers living in Brixton, South London, reveals the dialectic between identity and representation. The first section describes the research context, sets out the procedure to the 7 focus groups with a total of 44 school students (girls and boys from a variety of cultural backgrounds from three different secondary schools), and explains the process of computer-assisted qualitative analysis. In the second section I describe the findings. In exploring the different strategies teenagers use in the development of positive social identities and self-esteem, particularly in relation to black teenagers, the dynamic and contested nature of identity comes to the fore. These findings are then used, in section three, to demonstrate the value of incorporating social representations into social identity and self-categorisation theories. This demands a critical review of these theories and highlights the importance of representations in the construction of identity.

In this paper we use two very large panel datasets from Poland, 1988-90 and Czechoslovakia, 1990-1992 to explore the dynamics of employment and wage determination at the enterprise level in the early years of transition. The study is intended to assist in building a coherent picture of microeconomic adjustment in transition, a field which was not sufficiently explored in the early years of reform. We find that Polish firms were already to some extent responsive to market conditions pre-reform, notably to demand in determining employment. Czechoslovak firms, however, were largely unresponsive to such pressures in 1989-90. The elasticities rose significantly in both countries in the early years of reform, especially in Czechoslovakia which quickly attained initial Polish patterns of adjustment. Firms became much more responsive to sales and cost pressures in adjusting employment and to their own productivity in setting pay. Ownership effects in these early years were, however, much more modest, with state-owned firms adjusting employment more than their private counterparts, perhaps because over-manning was more serious in that sector.

Central to a transition from a command to a market economy is a radical transformation in the role of the state, involving both a withdrawal from economic decision-making and greater responsibilities for social welfare. Schematically, transition may be seen as consisting of three interrelated strands: first, the recasting of enterprises into institutions akin to firms in market economies and their disengagement from the state; second, an overhaul of the public finances and, particularly, the tax system; third, the institution of a social security system which does not rely on extensive price subsidies and secure lifetime employment. These three strands are closely intertwined because enterprises are the principal source of tax revenue and the main social welfare agencies in command economies. In the packages pressed on transitional economies the emphasis has been on a transformation of ownership of enterprises. Reform of the tax system and the institution of a social security system, in contrast, have not received the same attention. As is becoming increasingly obvious, a neglect of these is likely to expose the transition process to dangers and mistaken decisions which may seriously damage its prospects for success. In this paper we examine both the transformation of ownership in relation to the role of the state and tax reform in transitional economies.