943 resultados para loop closure


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The aim of this thesis is to critically examine drug prevention as a field of problematizations  – how drug prevention becomes established as a political technology within this field, how it connects to certain modes of governance, how and under which conditions it constitutes it’s problematic, the questions it asks,  it´s implications in terms of political participation and representation, the various bodies of knowledge through which it constitutes the reality upon which it acts, the limits it places on ways of being, questioning, and talking  in the world. The main analyses have been conducted in four separate but interrelated articles. Each article addresses a specific dimension of drug prevention in order to get a grasp of how this field is organized. Article 1 examines the shift that has occurred in the Swedish context during the period 1981–2011 in how drugs have been problematized, what knowledge has grounded the specific modes of problematization and which modes of governance this has enabled. In article 2, the currently dominant scientific discipline in the field of drug prevention – prevention science – is critically examined in terms of how it constructs the “drug problem” and the underlying assumptions it carries in regard to reality and political governance. Article 3 addresses the issue of communities’ democratic participation in drug prevention efforts by analyzing the theoretical foundations of the Communities That Care prevention program. The article seeks to uncover how notions of community empowerment and democratic participation are constructed, and how the “community” is established as a political entity in the program. The fourth and final article critically examines the Swedish Social and Emotional Training (SET) program and the political implications of the relationship the program establishes between the subject and emotions. The argument is made that, within the field of drug prevention, questions of political values and priorities in a problematic way are decoupled from the political field and pose a significant problem in terms of the possibilities to engage in democratic deliberation. Within this field of problematizations it becomes impossible to mobilize a politics against social injustice, poverty and inequality. At the same time, the scientific grounding of this mode of governing the drug “problem” acts to naturalize a specific – highly political – way of engaging with drugs.

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The calcitonin gene-related peptide (CGRP) receptor is a heterodimer of a family B G-protein-coupled receptor, calcitonin receptor-like receptor (CLR), and the accessory protein receptor activity modifying protein 1. It couples to Gs, but it is not known which intracellular loops mediate this. We have identified the boundaries of this loop based on the relative position and length of the juxtamembrane transmembrane regions 3 and 4. The loop has been analyzed by systematic mutagenesis of all residues to alanine, measuring cAMP accumulation, CGRP affinity, and receptor expression. Unlike rhodopsin, ICL2 of the CGRP receptor plays a part in the conformational switch after agonist interaction. His-216 and Lys-227 were essential for a functional CGRP-induced cAMP response. The effect of (H216A)CLR is due to a disruption to the cell surface transport or surface stability of the mutant receptor. In contrast, (K227A)CLR had wild-type expression and agonist affinity, suggesting a direct disruption to the downstream signal transduction mechanism of the CGRP receptor. Modeling suggests that the loop undergoes a significant shift in position during receptor activation, exposing a potential G-protein binding pocket. Lys-227 changes position to point into the pocket, potentially allowing it to interact with bound G-proteins. His-216 occupies a position similar to that of Tyr-136 in bovine rhodopsin, part of the DRY motif of the latter receptor. This is the first comprehensive analysis of an entire intracellular loop within the calcitonin family of G-protein-coupled receptor. These data help to define the structural and functional characteristics of the CGRP-receptor and of family B G-protein-coupled receptors in general. © 2006 by The American Society for Biochemistry and Molecular Biology, Inc.

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Purpose – The purpose of the paper is to present the findings of a study of factory closure management. It details the sequence and the results of the key strategic manufacturing management decisions made from the time of the announcement of the plant closure to the cessation of operations. The paper also includes an analysis of the human resource management (HRM) actions taken during this same time period and their consequences upon all those involved in the closure management process. Design/methodology/approach – The case study methodology consisted of two initial site visits to monitor closure management effectiveness (adherence to plan and the types and frequency of closure management communications). During these visits, documentary evidence of the impact of the closure decision upon production performance was also collected (manufacturing output and quality performance data). Following plant closure, interviews were held with senior business, production and HRM managers and production personnel. A total of 12 interviews were carried out. Findings – The case study findings have informed the development of a conceptual model of facility closure management. Information obtained from the interviews suggests that the facility closure management process consists of five key management activities. The unexpected announcement of a factory closure can cause behavioural changes similar to those of bereavement, particularly by those employees who are its survivors. In addition, similar reactions to the closure announcement may be displayed by those who choose to remain employed by the factory owner throughout the phased closure of the plant. Originality/value – Facility closure management is an insufficiently researched strategic operations management activity. This paper details a recommended procedure for its management. A conceptual model has also been developed to illustrate the links between the key facility closure management tasks and the range of employee changes of behaviour that can be induced by their execution.

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This paper reports on the development of elements of an e-supply chain management system for managing maintenance, repair and overhaul (MRO) relationships in the aerospace industry. A standard systems development methodology has been followed to produce a process model (i.e. the AMSCR model); an information model (i.e. business rules) and a computerised information management capability (i.e. automated optimisation). The proof of concept for this web-based MRO supply chain system has been established through the collaboration with a sample of the different types of supply chain members. The proven benefit is a reduction in the stock-holding costs for the whole supply chain whilst also minimising non-flying time of the aircraft that the supply chain supports. This type of system is now vital in an industry that has continuously decreasing profit margins, which in turn means pressure to reduce servicing times and increase the interval between maintenance actions.

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Case studies of knowledge management practices are often conducted in organizations where the aim is to manage knowledge for future operational improvements. What about knowledge management for organizations with limited life-spans that are preparing for closure? Such organizations are not common but can benefit from knowledge management strategy. This case study concerns the knowledge management strategy of an organization that is preparing for its final phase of operations. We facilitated two group workshops with senior managers to scope a strategy, following which the organization initiated a set of projects to implement the resulting actions. This paper reviews their implemented actions against those designed in the workshop to shed light on knowledge management in this uncommon situation.

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This paper examines how the loss of 6300 jobs from the closure of MG Rover (MGR) in the city of Birmingham (UK) in April 2005 affected the employment trajectories of ex-workers, in the context of wider structural change and efforts at urban renewal. The paper presents an analysis of a longitudinal survey of 300 ex-MGR workers, and examines to what extent the state of local labour markets and workers’ geographical mobility—as well as the effectiveness of the immediate policy response and longer-term local economic strategies—may have helped to balance the impacts of personal attributes associated with workers’ employability and their reabsorption into the labour markets. It is found that the relative buoyancy of the local economy, the success of longer-run efforts at diversification and a strong policy response and retraining initiative helped many disadvantaged workers to find new jobs in the medium term. However, the paper also highlights the unequal employment outcomes and trajectories that many lesser-skilled workers faced. It explores the policy issues arising from such closures and their aftermath, such as the need to co-ordinate responses, to retain institutional capacity, to offer high-quality training and education resources to workers and, where possible, to slow down such closure processes to enable skills to be retained and reused within the local economy.

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Influential models of short-term memory have attributed the fact that short words are recalled better than longer words in serial recall (the length effect) to articulatory rehearsal. Crucial for this link is the finding that the length effect disappears under articulatory suppression. We show, instead, that, under suppression, the length effect is abolished or reversed for real words but remains robust for nonwords. The latter finding is demonstrated in a variety of conditions: with lists of three and four nonwords, with nonwords drawn from closed and open sets, with spoken and written presentation, and with written and spoken output. Our interpretation is that the standard length effect derives from the number of phonological units to be retained. The length effect is abolished or reversed under suppression because this condition encourages reliance on lexical-semantic representations. Using these representations, longer words can more easily be reconstructed from degraded phonology than shorter words. © 2005 Elsevier Inc. All rights reserved.

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The transmission of a 10-Gb/s data stream was demonstrated experimentally over a practically unlimited distance in a standard single-mode fiber system using nonlinear optical loop mirrors as simple in-line 2R regenerators. Error-free propagation over 100 000 km has been achieved with terrestrial amplifier spacing. © 2004 IEEE.

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All-optical data processing is expected to play a major role in future optical communications. The fiber nonlinear optical loop mirror (NOLM) is a valuable tool in optical signal processing applications. This paper presents an overview of our recent advances in developing NOLM-based all-optical processing techniques for application in fiber-optic communications. The use of in-line NOLMs as a general technique for all-optical passive 2R (reamplification, reshaping) regeneration of return-to-zero (RZ) on-off keyed signals in both high-speed, ultralong-distance transmission systems and terrestrial photonic networks is reviewed. In this context, a theoretical model enabling the description of the stable propagation of carrier pulses with periodic all-optical self-regeneration in fiber systems with in-line deployment of nonlinear optical devices is presented. A novel, simple pulse processing scheme using nonlinear broadening in normal dispersion fiber and loop mirror intensity filtering is described, and its employment is demonstrated as an optical decision element at a RZ receiver as well as an in-line device to realize a transmission technique of periodic all-optical RZ-nonreturn-to-zero-like format conversion. The important issue of phase-preserving regeneration of phase-encoded signals is also addressed by presenting a new design of NOLM based on distributed Raman amplification in the loop fiber. © 2008 Elsevier Inc. All rights reserved.

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Observation of autosoliton propagation in a dispersion-managed optical transmission system controlled by in-line nonlinear fiber loop switches is reported for what is believed to be the first time. The system is based on a strong dispersion map with large amplifier spacing. Operation at transmission rates of 10 and 40 Gbits/s is demonstrated. ©2004 Optical Society of America.

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We demonstrate simultaneous demultiplexing, data regeneration and clock recovery at 10Gbits/s, using a single semiconductor optical amplifier–based nonlinear-optical loop mirror in a phase-locked loop configuration.

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We demonstrate bandpass nonlinear switching, using a novel device configuration based on a nonlinear-optical loop mirror and an in-fiber Bragg grating. Self-switching is demonstrated in the soliton regime by use of an asymmetrically arranged in-fiber Bragg grating as a wavelength-selective element. In addition, we adapt the configuration to perform efficient two-wavelength switching.