bluuebunny/crossref_metadata_2025 huggingface dataset:
Speaking out in public: citizen participation in contentious school board meetings
Authors: Tracy Karen , Durfy Margaret
Published: May 2007

A high level of citizen involvement in civic life is presumed crucial to the well-being of democracy, but the actual discourse of citizen involvement has rarely been analyzed. This article analyzes citizen participation in the school board meetings of one US community that was in the midst of conflict. After providing background on education governance practices and the community that was studied, citizen participation is examined. Citizen commentaries at school board meetings are shown to be a distinct speech genre and the genre is described. Then, we characterize the discourse practices used to express negative sentiment. Feeling-limned description, avowal of feelings, rhetorical questions, reported speech, use of god and devil terms, and using meeting rules as weapons were the main negative sentiment strategies. In the conclusion we suggest when low levels of citizen involvement should be acceptable, and why `reasonable hostility' is a desirable form of citizen expression.
Induction of lung lesions in Wistar rats by 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone and its inhibition by aspirin and phenethyl isothiocyanate
Authors: Ye Bo , Zhang Yu-Xia , Yang Fei , Chen Hong-Lei , Xia Dong , Liu Ming-Qiu , Lai Bai-Tang
Published: May 2007

Background

The development of effective chemopreventive agents against cigarette smoke-induced lung cancer could be greatly facilitated by suitable laboratory animal models, such as animals treated with the tobacco-specific lung carcinogen 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In the current study, we established a novel lung cancer model in Wistar rats treated with NNK. Using this model, we assessed the effects of two chemopreventive agents, aspirin and phenethyl isothiocyanate (PEITC), on tumor progression.

Methods

First, rats were treated with a single-dose of NNK by intratracheal instillation; control rats received iodized oil. The animals were then sacrificed on the indicated day after drug administration and examined for tumors in the target organs. PCNA, p63 and COX-2 expression were analyzed in the preneoplastic lung lesions. Second, rats were treated with a single-dose of NNK (25 mg/kg body weight) in the absence or presence of aspirin and/or PEITC in the daily diet. The control group received only the vehicle in the regular diet. The animals were sacrificed on day 91 after bronchial instillation of NNK. Lungs were collected and processed for histopathological and immunohistochemical assays.

Results

NNK induced preneoplastic lesions in lungs, including 33.3% alveolar hyperplasia and 55.6% alveolar atypical dysplasia. COX-2 expression increased similarly in alveolar hyperplasia and alveolar atypical dysplasia, while PCNA expression increased more significantly in the latter than the former. No p63 expression was detected in the preneoplastic lesions. In the second study, the incidences of alveolar atypical dysplasia were reduced to 10%, 10% and 0%, respectively, in the aspirin, PEITC and aspirin and PEITC groups, compared with 62.5% in the carcinogen-treated control group. COX-2 expression decreased after dietary aspirin or aspirin and PEITC treatment. PCNA expression was significantly reduced in the aspirin and PEITC group.

Conclusion

(1) A single dose of 25 mg/kg body weight NNK by intratracheal instillation is sufficient to induce preneoplastic lesions in Wistar rat lungs. (2) COX-2 takes part in NNK-induced tumorigenesis but is not involved in proliferation. (3) Aspirin and PEITC have protective effects in the early stages of tumor progression initiated by NNK.
Towards a meaningful manufacturing enterprise metamodel: A semantic driven framework
Authors: Neaga E I , Harding J A , Lin H-K
Published: May 2007

This paper presents a deep investigation and an interdisciplinary analysis of the collaborative networked enterprise engineering issues and modelling approaches related to the relevant aspects of the semantic web technology and knowledge strategies. The paper also suggests a novel framework based on ontology metamodelling, knowledge model discovery, and semantic web infrastructures, architectures, languages, and systems. The main aim of the research enclosed in this paper is to bridge the gaps between enterprise engineering, modelling, and especially networking by intensively applying semantic web technology based on ontology conceptual representations and knowledge discovery. The ontological modelling approaches together with knowledge strategies such as discovery (data mining) have become promising for future enterprise computing systems. The related reported research deals with the conceptual definition of a semantic-driven framework and a manufacturing enterprise metamodel (ME_M) using ontology, knowledge-driven object models, standards, and architectural approaches applied to collaborative networked enterprises. The conceptual semantic framework and related issues discussed in this paper may contribute towards new approaches of enterprise systems engineering and networking as well as applied standard and referenced ontological models.
Decision-making approach for the distribution centre location problem in a supply chain network using the fuzzy-based hierarchical concept
Authors: Chan F T S , Kumar N , Choy K L
Published: May 2007

In the era of global business and competitiveness, supply chain management has emerged as the critical factor for the success of companies. The past few decades have witnessed the importance of the linking channels among suppliers, manufacturers, and customers. The distribution centre (DC) location problem is a very fundamental and basic decision-making problem in terms of an efficient and effective supply chain. The decision concerning DC location, bearing in mind the current and future business perspective, is a cumbersome task and involves a large amount of investment. The selection of a site is a multicriterion decision-making problem and requires a thorough analysis of both qualitative and quantitative factors. The comparative study of different potential sites on a common set of criteria can help to handle the problem systematically and effectively. In general, most of the decision-making approaches such as the analytical hierarchy process (AHP) seem inefficient in handling the imprecise and vague linguistic comparisons of the different criteria. In this paper, a fuzzy integrated hierarchical decision-making approach is developed to solve the DC location selection problem. A case study adopted from previous literature is also discussed in this paper to show the effectiveness and robustness of the proposed methodology over the existing conventional hierarchical approaches.
Linear improvement of the machining stability lobes and application in milling process prediction
Authors: Geng Z , Ridgway K , Turner S
Published: May 2007

Aiming at an in-depth understanding of the machine tool-cutting tool dynamics and its integrated contribution to the machining process stability, this paper presents an improved linear approach for milling process stability prediction. Via modal decoupling and reconstruction, the dominant modes of the machine tool-cutting tool combination are reallocated and chatter criteria are redefined. Using optimally identified pole-pairs and residues, the experimentally measured frequency response function (FRF) at the cutting edge is renormalized, to achieve an improved calibration standard for calculation of the stability lobes. In addition, the cross-term modal coupling effects are introduced into the calculation of the orientated transfer function (OTF), which gives a better theoretical integrity and higher prediction precision. Using these theoretical improvements, software is developed and experimentally validated. This includes automatic trimming of stability lobes, acoustic validation of chatter vibration occurrence, etc. The effectiveness and applicability of the method developed are also discussed.
An exploration of key information models and their relationships in global manufacturing decision support
Authors: Liu Shaofeng , Young R I M
Published: May 2007

Global manufacturing businesses are beginning to benefit from the information and knowledge support provided by modern IT tools such as Product Lifecycle Management (PLM), Enterprise Resource Planning (ERP), and Customer Relations Management (CRM). Many types of information and knowledge, from customer requirements through product information to global enterprise manufacturing capability are involved in global manufacturing decisions. Understanding the appropriate structures and relationships for this information and knowledge is a significant issue if effective wide-ranging support is to be provided.

This paper focuses on global manufacturing decision support and explores three key types of information and knowledge relationship: (a) relationships between information and knowledge elements within a single information and knowledge model; (b) relationships between different information and knowledge models at one organizational level; (c) relationships between different information and knowledge models at different organizational levels. The corresponding information and knowledge structures have been presented with Unified Modelling Language (UML) to show the multiplicity of relationship required, and these are explored with an experimental system based on Rational Unified Process, Visual C++, and object-oriented DBMS ObjectStore. A case study has been pursued to explore the application of the information and knowledge models to a real industry environment.
Design by functional synonyms and antonyms: A structured creative technique based on functional analysis
Authors: Fantoni G , Taviani C , Santoro R
Published: May 2007

The present paper describes a technique based on functional analysis aimed at the development of creative ideas and breakthroughs in product design. Such an approach can also be used as a new structured brainstorming methodology for product development. New technical solutions can be generated and evaluated in the early design/redesign phases, influencing the whole product architecture and helping to identify critical ideas as well as weak points. The hypothesis is that functional description of products can be the foundation of a completely new design method based on lexical analysis and more precisely on the analysis of functional synonyms and antonyms. Functional analysis becomes the driving tool for specific design suggestions and improvements. Being highly structured, the method provides good grounds for problem solving: it guides creativity through codified steps and suggests directions of investigation.
Micro-electrode discharge machining: Factors affecting the quality of electrodes produced on the machine through the process of wire electro-discharge machining
Authors: Rees A , Dimov S S , Ivanov A , Herrero A , Uriarte L G
Published: May 2007

The introduction of a technique for on-the-machine electrode generation, utilizing wire electro-discharge grinding (WEDG) has broadened the application area of the microelectrode discharge machining (μEDM) process. The present paper studies the capabilities of the WEDG process for manufacturing micro-electrodes. The influence of electrode material, machining strategy, and machine accuracy on the quality of electrodes produced on-the-machine is investigated and a solution is proposed to improve this process. The experimental results reveal the limitations of the WEDG dressing and the effects of electrode material, machining strategy, and machine accuracy on electrode quality, achievable aspect ratio, and surface finish. The study shows that by employing an optical verification system the accuracy of the dressing process could be improved significantly.
A procedure to optimize the constrained multiple-item production system
Authors: Sharma S
Published: May 2007

A production environment is considered in which multiple items are produced in a cycle. Each item in the family has a certain shelf life. A capacity constraint is also imposed on the system. Procurement of input items corresponding to the finished products is modelled to facilitate smaller order quantities. To deal with the shelf life constraint, various options have been considered. The formulation is further extended to include a generalized production cost. In order to provide more generalism, shortages in the production system and different ordering frequencies for input items are allowed. A numerical example is provided for various options using different values of shop floor index. Different variants of the generalized model may be applied when one or more situations are not present. As the product life cycles are shorter nowadays, with some modifications, the planning period may be considered as a few years and obsolescence of the items may also be included.
Thermal modelling and experimental evaluation of laser-assisted dressing of superabrasive grinding wheels
Authors: Tian Yinggang , Shin Yung C
Published: May 2007

Laser-assisted dressing (LAD) has been proposed to prepare efficiently superabrasive grinding wheels by significantly reducing dressing forces and dresser wear. In this paper, a transient, three-dimensional heat transfer model is presented for LAD of superabrasive grinding wheels, where the effective thermophysical properties of the porous heterogeneous wheel are calculated and applied to the thermal model. Temperature measurements are conducted with an infrared camera and the excellent agreement between the measured and predicted temperatures show the validation of the present model for LAD of grinding wheels or, generally, laser-assisted machining of composite materials. To evaluate the influence of LAD on superabrasive wheels, grinding tests were carried out using a CBN wheel prepared by conventional and laser-assisted dressing respectively. The grinding tests show that LAD under proper conditions could improve the performance of CBN wheels.
Comparative evaluation of conventional and wiper ceramic tools on cutting forces, surface roughness, and tool wear in hard turning AISI D2 steel
Authors: Davim J Paulo , Figueira L
Published: May 2007

Recently, wiper ceramic inserts have emerged as a significant class of cutting tools, which are increasingly being utilized. This study considers the influence of the wiper inserts when compared with conventional inserts on the machinability parameters (cutting forces, surface roughness, and tool wear) obtained in hard turning of AISI D2 hardened steel. A plan of experiments was established considering hard turning with predetermined cutting parameters. An analysis of variance (ANOVA) was performed to investigate the machinability parameters using conventional and wiper inserts. With wiper ceramics inserts, machined surfaces with Ra < 0.8 μm were achievable. Consequently, surface qualities (dimensional accuracy) in a workpiece of mechanical precision, IT < 7, are possible.
High-velocity oxy-fuel thermally sprayed CoNiCrAlY coatings on Ti-6Al-4V alloy: High cycle fatigue properties of coating
Authors: Al-Anazi D , Hashmi M S J , Yilbas B S
Published: May 2007

Mechanical response of HVOF-coated workpieces is important for the life assessment of coating adherence, particularly for the coated surfaces being exposed to high-temperature environments prior to mechanical tests. In the present study, fatigue tests are carried out for Ti-6Al-4V workpieces coated via HVOF spraying of AMDRY 995 (CoNiCrAlY) powders. In order to simulate the effect of high temperature on the fatigue response of coating, workpieces were heat treated at the annealing temperature of the alloy for 1 h. Surface morphology prior to and after fatigue testing is carried out using scanning electron microscopy (SEM) and optical microscopy, while energy dispersive spectroscopy (EDS) and X-ray diffraction (XRD) are carried out for metallurgical examinations. It is found that heat treatment results in early fatigue failure of the workpieces owing to thermally induced stresses developed at the coating-substrate interface. The metallurgical changes in the substrate material, and formation of brittle oxygen compounds and alumina particles left over from grit blasting at the coating-substrate material interface are responsible for the coating failure.
Flow interactions in Pelton turbines and the hydraulic efficiency of the turbine system
Authors: Zhang Zh
Published: May 2007

Theoretical analysis has been performed to investigate the flow interaction between the jet and the rotating buckets as well as the relative flow in the buckets of Pelton turbines. The detailed calculation of cut-off processes of the jet by the rotating buckets provides the foundation both in evaluating existing layouts of Pelton turbines and in designing new ones. For achieving regular impact of the jet onto the buckets with minimum force fluctuations, the coincidence condition has been introduced, with which the optimum number of buckets for the Pelton wheel can also be determined. The effects of both centrifugal and Coriolis forces in the rotating bucket have been outlined in detail. In using the energy law to describe the relative flow of water in the rotating bucket, the so-called invariance equation has been derived and extended to apply to all parallel jet layers. This extension greatly simplifies the calculation of relative flow and hydraulic efficiency. Detailed calculation processes have been presented to quantitatively estimate the hydraulic efficiencies and their dependence on both the operating conditions and the bucket exit shapes.
Thermal analysis of a self-insulated type of radiant porous air heater using the spherical harmonics method
Authors: Nassab S. A Gandjalikhan.
Published: May 2007

In this work, an advance type of air heater is developed and analysed using porous radiant burners (PRBs). This system operates on the basis of the energy conversion process between gas enthalpy and thermal radiation via porous media. In the five-layered structure, which is analysed in this work, there are five porous layers that are separated by four special quartz glass windows. The main layer operates as a PRB that generates a large amount of thermal radiative energy and in the other layers, the energy conversion process takes place between gas enthalpy and thermal radiation. In order to determine the thermal characteristics of a newly proposed porous air heater (PAH), the coupled energy equations for the gas flows and porous layers and the radiative transfer equation are solved numerically by an iterative method. The spherical harmonics approximation is used to obtain the thermal radiative heat flux distribution inside the solidmatrices. Computational results show a very high efficiency for this type of PAH, in comparison with conventional ones.
Adaptive control for uncertain systems with sector-like bounded non-linear inputs
Authors: Chang Kuo-Ming
Published: May 2007

In the current paper, a model reference adaptive controller design based on hyper-stability theory is proposed for the uncertain non-linear system equipped with the so-called sector-like bounded non-linear inputs, which are subject to system uncertainties of the norm-bounded system parameter variations and external disturbances. The control objectives are to achieve an asymptotical tracking of the system output targeted to the desired reference model output and to ensure the bounded condition of all the signals in the controlled system. Finally, some computer simulation results are given to validate the excellent performance of the proposed adaptive control system.
Electromechanical integrated electrostatic harmonic actuator
Authors: Xu Lizhong , Qin Lei , Zhu Cuirong
Published: May 2007

An active electromechanical integrated electrostatic harmonic actuator is invented. The actuator is driven by a rotating electric field. In the actuator, integration of the harmonic drive, motor, and control can be realized. It is a new concept of the electromechanical drive system. The operating principle of the actuator is introduced. By means of electricity and mechanics, the driving mechanics of the actuator is analysed. Two different active states of the actuator are found. The formulae of the driving torque are given for two different active states, respectively. The limit output torque of the actuator is determined. Changes of the output torque along with elastic deformation of the flexible ring are presented. The load-carrying ability of the actuator is compared between two active states. The results are useful in further theory and technique studies on the actuator.
Dynamic surface control for stabilization of the oscillating eccentric rotor
Authors: Qaiser N , Hussain A , Iqbal N , Qaiser N
Published: May 2007

The present paper presents a new solution for the stabilization and disturbance attenuation problems of the oscillating eccentric rotor (OER), an extensively studied non-linear under-actuated mechanical system. Designing control law for such systems is a challenging task owing to the under-actuation property, which poses problems in exact feedback linearization. Presented non-linear controller design exploits the recently introduced dynamic surface control technique in a novel manner. The task of the controller is not only to de-spin the rotor but also to stop the translational oscillations. The design procedure is simpler and more intuitive than currently available integrator backstepping or energy-shaping-based designs. Stability is analysed by decomposing the system into a cascade of several subsystems. Advantages over existing controller designs are analysed theoretically and verified using numerical simulations. The design is found to attenuate oscillation amplitude effectively in the presence of an external sinusoidal translational disturbance besides aggressive stabilization.
Mathematical modelling and simulation of a jet pipe electrohydraulic flow control servo valve
Authors: Somashekhar S H , Singaperumal M , Kumar R Krishna
Published: May 2007

In this paper, the mathematical model of a jet pipe electrohydraulic flow control servo valve with a built-in mechanical feedback is developed. The actuator dynamics is also included. The solid and finite element (FE) models of the critical and precision components, feedback spring assembly and flexure tube of jet pipe assembly, were carried out first and simulated with appropriate boundary and loading conditions in a commercially available FE code, IDEAS, version 7.0, to ascertain the stiffnesses. To validate the obtained finite element results, experiments were carried out with a specially designed and fabricated test set-up. Moderately good agreement was observed between finite element and experimental values. The required simulation parameters for a jet pipe servo valve-actuator system, such as the moment of inertia, mass of the spool, mass of the piston, stiffness of the critical and precision components, and lever arm length, were obtained from the solid and finite element models. The developed model was simulated in commercially available software, MATLAB 6.5, Release 13. The step response of the valve was analysed. The simulation clearly showed the dynamics of the jet pipe, spool, and actuator displacement in achieving the equilibrium position when the applied torque and restoring torques balance, known as the steady state.
Mechatronics and buoyancy implementation of robotic fish swimming with modular fin mechanisms
Authors: Low K. H.
Published: May 2007

This paper presents an underwater vehicle mimicking the undulating fins of fish. To mimic the actual flexible fins of real fish, a fin-like mechanism is modelled with a series of connecting linkages. By virtue of a specially designed strip, each link is able to turn and slide with respect to the adjacent link. The driving linkages are used to form a mechanical fin consisting of several fin segments, which are able to produce undulations similar to those produced by the actual fins. Owing to the modular design and the flexible structure of the mechanical fin, it is possible to model different types of fin and to construct various biomimetic robots of fish swimming by fin undulations. On the other hand, a buoyancy tank has been designed and attached to the modular fin mechanisms for the complete fish swimming capability. The workspace of the fin mechanism is derived and applied in locomotion implementation. The mechatronics design and locomotion control of the integrated robotic fish are presented. Some qualitative and workspace observations by experiments with the robotic fish are also shown and discussed.
Adaptive and cooperative mobile robots
Authors: Pham D. T. , Awadalla M. H. , Eldukhri E. E.
Published: May 2007

This paper focuses on the development of intelligent multiagent robot teams capable of acting autonomously and of collaborating in a dynamic environment to reach team objectives. The paper proposes a new adaptive action selection architecture that enables a team of robot agents to achieve adaptive cooperative control and modify their performance during the specified time of the mission. These abilities are important because of uncertainty in the environmental conditions and because of possible functional failures in some team members. The improvement in team performance is achieved by updating the control parameters of the robots based on knowledge acquired on-line. Experiments have been conducted on teams of mobile robots performing a cooperative box-pushing task. The results show that the robot teams were able to achieve adaptive cooperative control despite dynamic changes in the environment and variations in the capabilities of the team members.
Position control of flexible manipulator using non-linear H∞ with state-dependent Riccati equation
Authors: Shawky A. M. , Ordys A. W. , Petropoulakis L , Grimble M. J.
Published: May 2007

The paper is concerned with the control of the tip position of a single-link flexible manipulator. The non-linear model of the manipulator is derived and tested, assuming the number of model shape functions to be two. It is known that the assumed modes method introduces uncertainty to the model by neglecting higher-order dynamics. There are other sources of uncertainty, such as friction. In addition, the model is non-linear. Therefore, for the next task, which is the controller design, the H∞ approach is proposed to deal efficiently with uncertainties, and the non-linear nature of the problem is addressed by the use of the state-dependent Riccati equation (SDRE) technique.

Following the SDRE approach, the state-feedback non-linear control law is derived, which minimizes a quadratic cost function. This solution is then mapped into the H∞ optimization problem. The resulting control law has been tested with the simulation model of the flexible manipulator and the results are discussed in the paper.
H∞ model matching two-degree-of-freedom control with adaptive torque ripple cancellation for high performance direct drive systems
Authors: Bogosyan S. O. , Goren L , Gokasan M
Published: May 2007

This study presents a novel adaptive robust control scheme to achieve a fast and accurate tracking performance in direct-drive (DD) systems under parameter and load uncertainties. The control combines an outer loop based on H∞ model matching (MM) in a two-degree-of-freedom (2-DOF) control structure, with an adaptive cancellation loop to increase torque ripple suppression further for improved tracking performance. A modified H∞ MM 2-DOF approach is taken by designing both the feedback loop and reference controller to achieve an improved tracking performance in the sense of H∞ MM criterion with integral action, while the robustness of the system is naturally satisfied by the 2-DOF control structure. Experimental results taken on a permanent magnet synchronous motor (PMSM) driven direct-drive system demonstrate a good tracking performance under a variety of reference trajectories. The results also demonstrate the robustness of the method against payload uncertainties and torque pulsations, except for the cogging torque components around the corner frequency. To improve attenuation of cogging torque terms further, the H∞ based outer loop is combined with an adaptive cancellation scheme derived based on the Lyapunov criteria. The developed adaptive robust control scheme demonstrates an improved robustness and tracking performance over a large frequency range.
Speed fluctuation and control of an electromechanical integrated toroidal drive
Authors: Xu Lizhong , Liu Xin
Published: May 2007

In this paper, the speed fluctuations of the drive system are presented and are expressed in Fourier series form. From the electromechanical coupled dynamic equations, the transfer function of the speed control for the drive system is derived. In order to remove the speed fluctuation and improve the response of the speed control system, a speed feedback control model is presented and a compensated input voltage is used. The effects of the mechanical and electrical parameters on the speed feedback control system of the drive system are investigated and the optimum parameters for the feedback control system are selected. The results show that a rapid response of the speed feedback control system is achieved and the speed fluctuation of the rotor is eliminated.
Sliding-mode control based on internal model principle
Authors: Lu Y-S
Published: May 2007

This paper proposes a sliding-mode control (SMC) scheme based on the internal model principle (IMP) for robust reference tracking and disturbance rejection. The conventional linear IMP-based controller is known for its capability of perfect tracking and disturbance rejection with an internal model of exogenous signals, while the traditional SMC controller is robust to system perturbations and exogenous signals with unknown dynamics. The proposed SMC design combines the best features of these two fundamentally different but effective methods. Furthermore, with the help of the SMC, an initial state of the internal model is determined independently of system perturbations in order that transient performance is greatly improved compared with that of the linear IMP-based controller. In addition, by properly assigning the initial state of the internal model, a sliding-control law is derived to ensure the existence of a sliding mode during an entire response. This global sliding motion yields excellent robustness of the entire system from the very beginning of a system response. Experimental results show the feasibility of the proposed scheme.
Casualty analysis of Aframax tankers
Authors: Papanikolaou A , Eliopoulou E , Alissafaki A , Mikelis N , Aksu S , Delautre S
Published: May 2007

The paper presents detailed results of a comprehensive analysis pertaining to Aframax tanker incidents and accidents that occurred in the last 26 years. The thorough review of the captured accident database information and the analysis of the historical records provided essential qualitative and quantitative information on a variety of parameters relevant to risk-based methodologies, namely the degree of severity and frequencies of accidents broken down into the pre-1990 and post-1990 periods, the spilled tonne rates and the impact of hull design and of ship's age, particularly on non-accidental structural failure accidents and geography of worldwide oil spills. The generated information enables conclusions on Aframax tanker accidents and of tankers in general to be drawn, for further exploitation in risk based design, operation and regulations.
Preparation and characterization of electrospun poly(butylene succinate-co-butylene adipate) nanofibrous nonwoven mats
Authors: Tserki V , Philippou J , Panayiotou C
Published: May 2007

Nanofibrous mats of poly(butylene succinate- co-butylene adipate) (PBSA) were prepared by electrospinning PBSA solutions in methylene chloride (MC) and MC/ N, N-dimethylformamide (DMF) mixtures. The morphology and the thermal properties of the electrospun mats were investigated by scanning electron microscopy (SEM), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC). The results showed that the addition of 20-30 per cent v/v DMF led to denser, more uniform, and without beads PBSA mats, with nanofibre average diameters ranging between 450 to 550 nm. The fibre morphology was also improved with increasing concentration and voltage. WAXD and DSC analysis showed a reduction in crystallinity and the thermal properties of the electrospun nanofibres, as compared to the raw material.
Control of negative poly(methyl methacrylate) for the elaboration of planar electrodes separated by a sub-10 nm gap
Authors: Grisolia J , Martin C , Ressier L , Peyrade J-P , Viallet B , Vieu C
Published: May 2007

The influence of the irradiation parameters of 200 keV electron beam lithography on poly(methyl methacrylate) (PMMA) was investigated to study its transformation from a positive resist to a negative resist, in order to create sub-10nm nanogap electrodes. At doses lower than 900 nC/cm (for line exposures) and 40 000 μC/cm2 (for area exposures), the scission process dominates, allowing PMMA to be used as a positive resist. At higher doses, however, the polymerization process becomes dominant and PMMA can be used as a negative resist. Specific features like sensitivity, contrast, resolution, and proximity effects were analyzed for both positive and negative processes on two kinds of isolated and nonisolated patterns: the study of the dose variation showed that it is more convenient to use a 2000 nC/cm dose to diminish the sensitivity to proximity effects of line exposure. As a result of our study, sub-10nm nanogap electrodes were then fabricated with negative PMMA using optimized conditions. We show that negative PMMA can be used as a high-resolution resist similarly to the positive resist in an simple process.
A nanotube composite microelectrode for monitoring dopamine levels using cyclic voltammetry and differential pulse voltammetry
Authors: Yun Y-H , Bange A , Shanov V. N. , Heineman W. R. , Halsall H. B. , Wong D. K. Y. , Behbehani M , Pixley S , Bhattacharya A , Dong Z , Schulz M. J.
Published: May 2007

Needle-type nanotube composite microelectrodes were fabricated by injecting a carbon nanotube epoxy solution into pulled-glass tubes. Electrochemical impedance spectroscopy was used to study the complex impedance of the electrode and showed that the electron transfer resistance of the electrode decreases with an increase in the percentage of nanotubes in the epoxy. Cyclic voltammetry was performed under reducing conditions in 6.0mM K3Fe(CN)6 to examine the surface properties of the microelectrodes. The results showed a steady-state response up to 0.5 V/s attributable to radial diffusion with a high steady-state current density. Cyclic voltammetry and differential pulse voltammetry were then used to detect dopamine. The results showed a linear response with a sensitivity of 100nA/mM. Based on the cyclic voltammetry and differential pulse voltammetry results, needle-type nanotube composite microelectrodes are promising sensors for detecting neurotransmitters.
Characterization of ionic transport at the nanoscale
Authors: Prakash S , Yeom Junghoon , Jin Niu , Adesida I , Shannon M. A.
Published: May 2007

This paper reports on the development of a multi-layer microscale impedance measurement system with integrated working, counter, and reference electrodes that can be used to probe transport at the nanoscale. System fabrication and testing are carried out to demonstrate the feasibility of such a system for characterizing transport through nanocapillary array membranes (NCAMs). Results indicate that transport through NCAMs is a complex phenomenon, and impedance does not scale linearly with either pore diameter or ionic concentration. Use of a microscale construct for probing ionic transport at the nanoscale appears to be a promising path forward with further development.
Adults' representations of the Earth: Implications for children's acquisition of scientific concepts
Authors: Nobes Gavin , Panagiotaki Georgia
Published: May 2007

When children are asked to draw the Earth they often produce intriguing pictures in which, for example, people seem to be standing on a flat disc or inside a hollow sphere. These drawings, and children's answers to questions, have been interpreted as indicating that children construct naïve, theory‐like mental models of the Earth (e.g. Vosniadou & Brewer, 1992). However, recent studies using different methods have found little or no evidence of these mental models, and report that many young children have some scientific knowledge of the Earth. To examine the reasons for these contrasting findings, adults (N = 350) were given the drawing task previously given to 5‐year‐old children. Fewer than half of the adults' pictures were scientific, and 15% were identical to children's ‘naïve’ drawings. Up to half of the answers to questions (e.g. ‘Where do people live?’) were non‐scientific. Open‐ended questions and follow‐up interviews revealed that non‐scientific responses were given because adults found the apparently simple task confusing and challenging. Since children very probably find it even more difficult, these findings indicate that children's non‐scientific responses, like adults', often result from methodological problems with the task. These results therefore explain the discrepant findings of previous research, and support the studies which indicate that children do not have naïve mental models of the Earth.
Early hyponatraemia after pituitary surgery: cerebral salt-wasting syndrome
Authors: Guerrero R , Pumar A , Soto A , Pomares M A , Palma S , Mangas M A , Leal A , Villamil F
Published: May 2007

Hyponatraemia is a common complication in patients undergoing neurosurgery. It can be caused either by the syndrome of inappropriate secretion of antidiuretic hormone or by the cerebral salt-wasting syndrome (CSWS). CSWS frequently occurs in patients suffering from subarachnoid haemorrhage and brain injury, but it is rare after pituitary tumour surgery. However, this diagnostic possibility should be considered as these disorders require specific treatment and have different prognoses.

In this article, we present a case of acute and early hyponatraemia caused by CSWS after pituitary tumour surgery. We also revise the aetiology, mechanisms, differential diagnosis and treatment of hyponatraemia after pituitary surgery.
Changes in calf muscle elasticity in hypogonadal males before and after testosterone substitution as monitored by magnetic resonance elastography
Authors: Brauck Katja , Galbán Craig J , Maderwald Stefan , Herrmann Burkhard L , Ladd Mark E
Published: May 2007

Purpose: We sought to determine whether differences in muscle elasticity between healthy age-related controls and patients with hypogonadism could be measured by a new, non-invasive method termed magnetic resonance elastography (MRE).

Materials and methods: Twelve hypogonadal (21–68 years) and twenty-seven healthy age-related men (20–76 years) were examined. In the hypogonadism group, serum testosterone levels were compared and MRE was conducted prior to and after 6 months of therapy in 6 of the 12 patients. MRE was performed by mechanically exciting the soleus muscle that was used because of its uniformly distributed muscle fibers, size, and accessibility, with a custom designed piezoelectric-actuator using a modified phase-contrast sequence. For mechanical excitation the actuator lever was placed on the anterior surface of the calf. The subjects had to maintain a force of 0–20% of their maximum voluntary contraction against a home-built footplate that was mounted on the MR table. All images were phase unwrapped and reconstructed into shear modulus elastograms using the local frequency estimation technique.

Results: Testosterone levels were significantly higher after 6 months of treatment. A statistical difference in the shear modulus was observed prior to and after 6 months of testosterone therapy and was nearly the same as in the healthy age-related control group.

Conclusion: MRE seems to be a promising technique for the evaluation of therapeutic effects in patients with hypogonadism and possibly in other diseases with muscular effects.
Superiority of skinfold measurements and waist over waist-to-hip ratio for determination of body fat distribution in a population-based cohort of Caucasian Dutch adults
Authors: Ketel Iris J G , Volman Mariken N M , Seidell Jacob C , Stehouwer Coen D A , Twisk Jos W , Lambalk Cornelis B
Published: May 2007

Objective: To determine which anthropometric measurement is the most reliable alternative for fat distribution as measured by dual-energy X-ray absorptiometry (DXA).

Design: Population-based survey carried out in Amsterdam, The Netherlands.

Subjects and methods: A total of 376 individuals (200 women) with a mean age of 36.5 years and mean body mass index (BMI) of 24.0 (±3.1) kg/m2 underwent various anthropometric and DXA measurements of central (CFM) and peripheral fat mass (PFM). Furthermore, for the assessment of apple-shaped body composition, CFM-to-PFM ratio was calculated. Anthropometric measurements were waist and hip circumference, waist-to-hip ratio (WHR), BMI, waist/length and the skinfold thickness of biceps, triceps, suprailiacal (SI), subscapular (SS) and upper leg. We determined whether equations of combined anthropometrics were even more reliable for the assessment of fat mass.

Results: In both women and men, reliable alternatives for CFM are central skinfolds and waist (Pearson’s correlation (r) ≥ 0.8). Peripheral skinfolds are the best predictors of PFM (r ≥ 0.8). In contrast, WHR correlated only marginally with any of the DXA measurements. Equations based on several anthropometric variables correlate with CFM even better (R2 ≥ 0.8). CFM-to-PFM ratio has the highest correlation with the ratio (SS+SI)/BMI in women (r = 0.66) and waist/length in men (r = 0.71). Equations are reasonable alternatives of CFM-to-PFM ratio (R2 ≥ 0.5).

Conclusion: Waist and skinfolds are reliable alternatives for the measurement of body fat mass in a cohort of Caucasian adults. WHR is not appropriate for the measurement of fat distribution.
Co-localisation of the Kir6.2/SUR1 channel complex with glucagon-like peptide-1 and glucose-dependent insulinotrophic polypeptide expression in human ileal cells and implications for glycaemic control in new onset type 1 diabetes
Authors: Nielsen Lotte B , Ploug Kenneth B , Swift Peter , Ørskov Cathrine , Jansen-Olesen Inger , Chiarelli Francesco , Holst Jens J , Hougaard Philip , Pörksen Sven , Holl Reinhard , de Beaufort Carine , Gammeltoft Steen , Rorsman Patrik , Mortensen Henrik B , Hansen Lars , _ _
Published: May 2007

Objective: The ATP-dependent K+-channel (KATP) is critical for glucose sensing and normal glucagon and insulin secretion from pancreatic endocrine α- and β-cells. Gastrointestinal endocrine L- and K-cells are also glucose-sensing cells secreting glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotrophic polypeptide (GIP) respectively. The aims of this study were to 1) investigate the expression and co-localisation of the KATP channel subunits, Kir6.2 and SUR1, in human L- and K-cells and 2) investigate if a common hyperactive variant of the Kir6.2 subunit, Glu23Lys, exerts a functional impact on glucose-sensing tissues in vivo that may affect the overall glycaemic control in children with new-onset type 1 diabetes.

Design and methods: Western blot and immunohistochemical analyses were performed for expression and co-localisation studies. Meal-stimulated C-peptide test was carried out in 257 children at 1, 6 and 12 months after diagnosis. Genotyping for the Glu23Lys variant was by PCR-restriction fragment length polymorphism.

Results: Kir6.2 and SUR1 co-localise with GLP-1 in L-cells and with GIP in K-cells in human ileum tissue. Children with type 1 diabetes carrying the hyperactive Glu23Lys variant had higher HbA1C at bdiagnosis (coefficient = 0.61%, P = 0.02) and 1 month after initial insulin therapy (coefficient = 0.30%, P = 0.05), but later disappeared. However, when adjusting HbA1C for the given dose of exogenous insulin, the dose-adjusted HbA1C remained higher throughout the 12 month study period (coefficient = 0.42%, P = 0.03).

Conclusions: Kir6.2 and SUR1 co-localise in the gastrointestinal endocrine L- and K-cells. The hyperactive Glu23Lys variant of the KATP channel subunit Kir6.2 may cause defective glucose sensing in several tissues and impaired glycaemic control in children with type 1 diabetes.
Quantitative liver functions in Turner syndrome with and without hormone replacement therapy
Authors: Gravholt Claus Højbjerg , Poulsen Henrik Enghusen , Ott Peter , Christiansen Jens Sandahl , Vilstrup Hendrik
Published: May 2007

Background: Studies have documented elevated levels of liver enzymes in many females with Turner syndrome (TS). Histology has shown a range of changes. Treatment with female hormone replacement therapy (HRT) reduces liver enzymes.

Aim: To study quantitative liver functions in TS in detail with and without HRT.

Design: Randomized crossover study with active treatment (HRT in TS and P-pill in controls) or no treatment.

Subjects: Women with TS (n = 8, age 29.7 ± 5.6 (mean ± s.d.) years), verified by karyotype, and age-matched controls (C; n = 8, age 27.3 ± 4.9 years).

Methods: We determined liver enzymes in blood, used the galactose elimination capacity to assess hepatocyte cytosol activity, plasma clearance of indocyanine green to assess excretory function, antipyrine clearance to estimate microsomal activity, and the functional hepatic nitrogen clearance (FHNC) to assess mitochondrial-cytosolic metabolic capacity for conversion of amino-nitrogen.

Results: Liver enzymes were elevated in untreated TS and reduced by HRT. The hepatic capacities for conversion of galactose, indocyanine green, and antipyrine were normal and did not change by HRT. The FHNC was marginally reduced (untreated TS vs C: 19.4 ± 5.4 vs 25.2 ± 7.3 L/h, P = 0.1). FHNC changed slightly with HRT in TS (19.4 ± 5.4 vs 24.4 ± 10.2 L/h, P = 0.2).

Conclusions: The elevations of liver enzymes in untreated TS are readily suppressed by HRT. Quantitative liver functions in TS are comparable to controls and are not affected by HRT.
The New Hungarian Translation of Aristotle's Poetics When Translation and Commentary Disagree
Authors: Hajdu Péter
Published: May 2007

A new translation of
Aristotle's
Poetics
was recently published with an extensive commentary.
The translator and the commentator are not the same person, therefore they can
have different views on the meaning of the text. The paper discusses some
passages from the translation, especially highlighting the method of quoting
after certain words the original Greek word in parentheses. This method calls
attention to the original identity of different words. The method, however was
not applied consistently. The same Greek word in some places appears in
parentheses after its Hungarian version; in other places it does not. There are
too many misprints in the book, but the commentary helps the reader, since it
sometimes refers to better versions of the translation than the actually
printed ones. The commentary must have been written to a previous version of
the translation, which did not yet contain the misprints. After the discussion
of some problematic passages of the commentary the last part of the paper
contains some remarks on the section headings the commentator supplied. They
can help orient the reader, but they are not distinguished from the body of the
text clearly enough. On the other hand, a section heading determines a reading
strategy for the following passage, and a reader can hardly avoid this
influence.
Conference Reports
Authors: Kis Balázs
Published: May 2007

“Specialised
Communication and Translation: On the User's Side Comunicazione specialistica e
traduzione: dalla parte dell'utente”Scuola Superiore di Lingue Moderne per
Interpreti e Traduttori. Trieste Italy 29 November - 1 December 2001 , Training
Seminar on Translation and Localisation Universitat Rovira i Virgili, Tarragona
Spain 10-11 May 2002 , Challenges of Translation in Software
Localisation , Using Computer-Aided Translation Tools and Other Electronic
Resources , Localisation: Challenge to Translation Teaching , Conclusion