3D-QSAR studies on 4-Hydroxyphenylpyruvate Dioxygenase inhibitors by comparative molecular field analysis (CoMFA)

A comparative molecular field analysis (CoMFA) of alkanoic acid 3-oxo-cyclohex-1-enyl ester and 2-acylcyclohexane-1,3-dione derivatives of 4-hydroxyphenylpyruvate dioxygenase inhibitors has been performed to determine the factors required for the activity of these compounds. The substrate's conformation abstracted from dynamic modeling of the enzyme-substrate complex was used to build the initial structures of the inhibitors. Satisfactory results were obtained after an all-space searching procedure, performing a leave-one out (LOO) cross-validation study with cross-validation q(2) and conventional r(2) values of 0.779 and 0.989, respectively. The results provide the tools for predicting the affinity of related compounds, and for guiding the design and synthesis of new HPPD ligands with predetermined affinities.

Fault reconstruction in linear dynamic systems using multivariate statistics

Treasure et al. (2004) recently proposed a new sub space-monitoring technique, based on the N4SID algorithm, within the multivariate statistical process control framework. This dynamic-monitoring method requires considerably fewer variables to be analysed when compared with dynamic principal component analysis (PCA). The contribution charts and variable reconstruction, traditionally employed for static PCA, are analysed in a dynamic context. The contribution charts and variable reconstruction may be affected by the ratio of the number of retained components to the total number of analysed variables. Particular problems arise if this ratio is large and a new reconstruction chart is introduced to overcome these. The utility of such a dynamic contribution chart and variable reconstruction is shown in a simulation and by application to industrial data from a distillation unit.

The Architecture of Seduction: An Analysis on Digital Architectures within Consumer Society

Currently new digital tools used in architecture are often at the service of a conception of architecture as a consumer society’s cultural good. Within this neoliberal cultural frame, architects’ social function is no longer seen as the production of urban facts with sense of duty, but as a part within the symbolic logic that rules the social production of cultural values as it was defined by Veblen and developed by Baudrillard. As a result, the potential given by the new digital tools used in representation has shifted from an instrument used to verify a built project to two different main models: At the one hand the development of pure virtual architectures that are exclusively configured within their symbolic value as artistic “images” easily reproducible. On the other hand the development of all those projects which -even maintaining their attention to architecture as a built fact- base their symbolic value on the author’s image and on virtual aesthetics and logics that prevail over architecture’s materiality. Architects’ sense of duty has definitely reached a turning point.

Time of flight mass spectrometry for quantitative data analysis in fast transient studies using a Temporal Analysis of Products (TAP) reactor

A Time of flight (ToF) mass spectrometer suitable in terms of sensitivity, detector response and time resolution, for application in fast transient Temporal Analysis of Products (TAP) kinetic catalyst characterization is reported. Technical difficulties associated with such application as well as the solutions implemented in terms of adaptations of the ToF apparatus are discussed. The performance of the ToF was validated and the full linearity of the specific detector over the full dynamic range was explored in order to ensure its applicability for the TAP application. The reported TAP-ToF setup is the first system that achieves the high level of sensitivity allowing monitoring of the full 0-200 AMU range simultaneously with sub-millisecond time resolution. In this new setup, the high sensitivity allows the use of low intensity pulses ensuring that transport through the reactor occurs in the Knudsen diffusion regime and that the data can, therefore, be fully analysed using the reported theoretical TAP models and data processing.

Spatio-temporal analysis of DNA damage repair using the X-ray microbeam

Cellular response to radiation damage is made by a complex network of pathways and feedback loops whose spatiotemporal organization is still unclear despite its decisive role in determining the fate of the damaged cell. The single-cell approach and the high spatial resolution offered by microbeams provide the perfect tool to study and quantify the dynamic processes associated with the induction and repair of DNA damage. The soft X-ray microbeam has been used to follow the development of radiation induced foci in live cells by monitoring their size and intensity as a function of dose and time using yellow fluorescent protein (YFP) tagging techniques. Preliminary data indicate a delayed and linear rising of the intensity signal indicating a slow kinetic for the accumulation of DNA repair protein 53BP1. A slow and limited foci diffusion has also been observed. Further investigations are required to assess whatever such diffusion is consistent with a random walk pattern or if it is the result of a more structured lesion processing phenomenon. In conclusion, our data indicates that the use of microbeams coupled to live cell microscopy represent a sophisticated approach for visualizing and quantifying the dynamics changes of DNA proteins at the damaged sites.

Framework for Establishing Limits of Tabular Aerodynamic Models for Flight Dynamics Analysis

This paper describes the use of the Euler equations for the generation and testing of tabular aerodynamic models for flight dynamics analysis. Maneuvers for the AGARD Standard Dynamics Model sharp leading-edge wind-tunnel geometry are considered as a test case. Wind-tunnel data is first used to validate the prediction of static and dynamic coefficients at both low and high angles, featuring complex vortical flow, with good agreement obtained at low to moderate angles of attack. Then the generation of aerodynamic tables is described based on a data fusion approach. Time-optimal maneuvers are generated based on these tables, including level flight trim, pull-ups at constant and varying incidence, and level and 90 degrees turns. The maneuver definition includes the aircraft states and also the control deflections to achieve the motion. The main point of the paper is then to assess the validity of the aerodynamic tables which were used to define the maneuvers. This is done by replaying them, including the control surface motions, through the time accurate computational fluid dynamics code. The resulting forces and moments are compared with the tabular values to assess the presence of inadequately modeled dynamic or unsteady effects. The agreement between the tables and the replay is demonstrated for slow maneuvers. Increasing rate maneuvers show discrepancies which are ascribed to vortical flow hysteresis at the higher rate motions. The framework is suitable for application to more complex viscous flow models, and is powerful for the assessment of the validity of aerodynamics models of the type currently used for studies of flight dynamics.

Analysis of information leakage from encrypted Skype conversations

Voice over IP (VoIP) has experienced a tremendous growth over the last few years and is now widely used among the population and for business purposes. The security of such VoIP systems is often assumed, creating a false sense of privacy. This paper investigates in detail the leakage of information from Skype, a widely used and protected VoIP application. Experiments have shown that isolated phonemes can be classified and given sentences identified. By using the dynamic time warping (DTW) algorithm, frequently used in speech processing, an accuracy of 60% can be reached. The results can be further improved by choosing specific training data and reach an accuracy of 83% under specific conditions. The initial results being speaker dependent, an approach involving the Kalman filter is proposed to extract the kernel of all training signals.

A concept analysis of renal supportive care: the changing world of nephrology

Title. A concept analysis of renal supportive care: the changing world of nephrology

Aim. This paper is a report of a concept analysis of renal supportive care.

Background. Approximately 1.5 million people worldwide are kept alive by renal dialysis. As services are required to support patients who decide not to start or to withdraw from dialysis, the term renal supportive care is emerging. Being similar to the terms palliative care, end-of-life care, terminal care and conservative management, there is a need for conceptual clarity.

Method. Rodgers' evolutionary method was used as the organizing framework for this concept analysis. Data were collected from a review of CINAHL, Medline, PsycINFO, British Nursing Index, International Bibliography of the Social Sciences and ASSIA (1806-2006) using, 'renal' and 'supportive care' as keywords. All articles with an abstract were considered. The World Wide Web was also searched in English utilizing the phrase 'renal supportive care'.

Results. Five attributes of renal supportive care were identified: available from diagnosis to death with an emphasis on honesty regarding prognosis and impact of disease; interdisciplinary approach to care; restorative care; family and carer support and effective, lucid communication to ensure informed choice and clear lines of decision-making.

Conclusion. Renal supportive care is a dynamic and emerging concept relevant, but not limited to, the end phase of life. It suggests a central philosophy underpinning renal service development that allows patients, carers and the multidisciplinary team time to work together to realize complex goals. It has relevance for the renal community and is likely to be integrated increasingly into everyday nephrology practice.

Dynamic Linear Precoding for the Exploitation of Known Interference in MIMO Broadcast Systems

This paper introduces a novel channel inversion (CI) precoding scheme for the downlink of phase shift keying (PSK)-based multiple input multiple output (MIMO) systems. In contrast to common practice where knowledge of the interference is used to eliminate it, the main idea proposed here is to use this knowledge to glean benefit from the interference. It will be shown that the system performance can be enhanced by exploiting some of the existent inter-channel interference (ICI). This is achieved by applying partial channel inversion such that the constructive part of ICI is preserved and exploited while the destructive part is eliminated by means of CI precoding. By doing so, the effective signal to interference-plus-noise ratio (SINR) delivered to the mobile unit (MU) receivers is enhanced without the need to invest additional transmitted signal power at the MIMO base station (BS). It is shown that the trade-off to this benefit is a minor increase in the complexity of the BS processing. The presented theoretical analysis and simulations demonstrate that due to the SINR enhancement, significant performance and throughput gains are offered by the proposed MIMO precoding technique compared to its conventional counterparts.

Absorbing new knowledge in small and medium-sized enterprises: A multiple case analysis of Six Sigma

The primary aim of this article is to critically analyse the development of Six Sigma theory and practice within small and medium-sized enterprises (SMEs) using a multiple case study approach. The article also explores the subsequent development of Lean Six Sigma as a means of addressing the perceived limitations of the efficacy of Six Sigma in this context. The overarching theoretical framework is that of absorptive capacity, where Six Sigma is conceptualized as new knowledge to be absorbed by smaller firms. The findings from a multiple case study involving repeat interviews and focus groups informed the development of an analytical model demonstrating the dynamic underlying routines for the absorptive capacity process and the development of a number of summative propositions relating the characteristics of SMEs to Six Sigma and Lean Six Sigma implementation.

A Question of Legitimacy? A Dynamic Perspective on Multinational Firm Control

The control and coordination of a network of geographically and culturally dispersed subsidiaries is one of the most prominent challenges in international management. However, many empirical findings on the effectiveness of various control mechanisms and combinations thereof are still counterintuitive. This study uses longitudinal case studies and cross-sectional interview data to extend control theory by examining why, how, and in what sequence large multinational firms (MNCs) implement controls in their networks of foreign subsidiaries. Our analysis draws from literature on institutional theory, embeddedness, and organizational power to demonstrate that MNC headquarters need to overcome institutional duality when implementing their controls abroad. We find that headquarters do so by using social controls, primarily as a way of legitimizing and institutionalizing their process and output controls that are implemented subsequently.

Finite Element Application to Analysis, Testing, and Manufacturing of Satellite Structures

Designing satellite structures poses an ongoing challenge as the interaction between analysis, experimental testing, and manufacturing phases is underdeveloped. Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing explains the theoretical and practical knowledge needed to perform design of satellite structures. By layering detailed practical discussions with fully developed examples, Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing provides the missing link between theory and implementation.
Computational examples cover all the major aspects of advanced analysis; including modal analysis, harmonic analysis, mechanical and thermal fatigue analysis using finite element method. Test cases are included to support explanations an a range of different manufacturing simulation techniques are described from riveting to shot peening to material cutting. Mechanical design of a satellites structures are covered in three steps: analysis step under design loads, experimental testing to verify design, and manufacturing.
Stress engineers, lecturers, researchers and students will find Finite Element Analysis for Satellite Structures: Applications to Their Design, Manufacture and Testing a key guide on with practical instruction on applying manufacturing simulations to improve their design and reduce project cost, how to prepare static and dynamic test specifications, and how to use finite element method to investigate in more details any component that may fail during testing.

Autoclave Cure Simulation of Composite Structures Applying Implicit and Explicit FE

Simulation of the autoclave manufacturing technique of composites can yield a preliminary estimation of induced residual thermal stresses and deformations that affect component fatigue life, and required tolerances for assembly. In this paper, an approach is proposed to simulate the autoclave manufacturing technique for unidirectional composites. The proposed approach consists of three modules. The first module is a Thermo-chemical model to estimate the temperature and the degree of cure distributions in the composite part during the cure cycle. The second and third modules are a sequential stress analysis using FE-Implicit and FE-Explicit respectively. User-material subroutine is used to model the Viscoelastic properties of the material based on theory of micromechanics.

Virtual Manufacturing of Composite Structures Applying Implicit and Explicit FE Techniques

Virtual manufacturing of composites can yield an initial early estimation of the induced residual thermal stresses that affect component fatigue life, and deformations that affect required tolerances for assembly. Based on these estimation, the designer can make early decisions, which can help in reducing cost, regarding changes in part design or material properties. In this paper, an approach is proposed to simulate the autoclave manufacturing technique for unidirectional composites. The proposed approach consists of three modules. The first module is a Thermochemical model to estimate temperature and the degree of cure distributions in the composite part during the cure cycle. The second and third modules are stress analysis using FE-Implicit and FE-Explicit respectively. User-material subroutine will be used to model the Viscoelastic properties of the material based on micromechanical theory. Estimated deformation of the composite part can be corrected during the autoclave process by modifying the process-tool design. The deformed composite surface is sent to CATIA for design modification of the process-tool.

Mechanical fatigue and spectrum analysis of small-satellite

Mechanical fatigue due to environmental loads and spectrum analysis due to launch loads of the primary structure of a low cost, low-earth orbit small satellite intended for earth observation missions are presented. The payload of the satellite under consideration is a precise optical unit to image the earth’s surface having a mass of 45 kg. 3-D Finite Element Model for the satellite structure is generated by applying substructure method. Modal analysis is required to determine natural frequencies of the satellite and define its mode shape. Then, ranking of mode shapes according to specific constraint is performed. Harmonic analysis at resonance frequencies with the highest ranking is done and cumulative fatigue damage analysis is performed. Spectrum analysis is performed for Small Sat structure to verify the satellite structure reliability under all dynamic random vibration loads applied during transportation and launch cases.