5,122 research outputs found

    Reconceptualising academic development as community development: lessons from working with Syrian academics in exile

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    This paper focuses on academic development for Syrian academics in exile. Academic development first emerged in resource-rich, global North environments including the UK, the USA, Australia, and Scandinavia nearly 50 years ago as reported by Gosling (International Journal for Academic Development, 14(1):5–18, 2009), and the majority of research studies in this field focus on activities in global North, resource-rich, institutional settings. Yet academics in resource-poor, [post-] conflict and post-colonial contexts face different challenges and circumstances, and have different academic development needs. This paper extends the conceptual and contextual scope of this field by investigating the experiences and academic development needs of Syrian academics in exile, and interrogating the concept of academic development within that context. It establishes the background context of Syrian academia in exile, before summarising the nature and aims of the Council for At Risk Academics (Cara) Syria Programme. It then outlines the study’s methodology, before presenting the findings of a thematic analysis of a multi-level data set. It then interrogates the concept and normative terrain of academic development in light of these findings, and proposes a model for academic community development to support academic communities in exile, and marginalised academic communities more widely

    Experimental Realization of a Single-Phase Five Level Inverter for PV Applications

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    voltage-controlled, single-phase, five-level inverter for photovoltaic systems using semiconductor power devices is proposed. Use of a unique, multilevel voltage source configuration allows the production of high voltage, low harmonic distortion AC outputs without using transformers or series-associated synchronized switching devices. The typical role of multi-level inverters is to generate the desired AC voltage from multiple DC voltage rails. Therefore multi-level inverters can provide high power AC outputs with good efficiency. The inverter design proposed here has superior voltage regulation, a low-distortion output and improved efficiency compared to existing multi-level inverters. Complete functionality has been verified using both MATLAB/SIMULINK simulation software and experimental trial

    Cellular and Synaptic Actions of Acetylcholine in the Lamprey Spinal Cord

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    This study investigated cellular and synaptic mechanisms of cholinergic neuromodulation in the in vitro lamprey spinal cord. Most spinal neurons tested responded to local application of acetylcholine (ACh) with depolarization and decreased input resistance. The depolarization persisted in the presence of either tetrodotoxin or muscarinic antagonist scopolamine and was abolished with nicotinic antagonist mecamylamine, indicating a direct depolarization through nicotinic ACh receptors. Local application of muscarinic ACh agonists modulated synaptic strength in the spinal cord by decreasing the amplitude of unitary excitatory and inhibitory postsynaptic potentials. The postsynaptic response to direct application of glutamate was unchanged by muscarinic agonists, suggesting a presynaptic mechanism. Cholinergic feedback from motoneurons was assessed using stimulation of a ventral root in the quiescent spinal cord while recording intracellularly from spinal motoneurons or interneurons. Mainly depolarizing potentials were observed, a portion of which was insensitive to removal of extracellular Ca2+, indicating electrotonic coupling. Hyperpolarizing potentials were also observed and were attenuated by the glycinergic antagonist strychnine, whereas depolarizing responses were potentiated by strychnine. Mecamylamine also reduced hyperpolarizing responses. The pharmacology of these responses suggests a Renshaw-like feedback pathway in lamprey. Immunohistochemistry for choline acetyltransferase, performed in combination with retrograde filling of motoneurons, demonstrated a population of nonmotoneuron cholinergic cells in the lamprey spinal cord. Thus endogenous cholinergic modulation of the lamprey spinal locomotor network is likely produced by both motoneurons and cholinergic interneurons acting via combined postsynaptic and presynaptic actions

    Learning a Static Analyzer from Data

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    To be practically useful, modern static analyzers must precisely model the effect of both, statements in the programming language as well as frameworks used by the program under analysis. While important, manually addressing these challenges is difficult for at least two reasons: (i) the effects on the overall analysis can be non-trivial, and (ii) as the size and complexity of modern libraries increase, so is the number of cases the analysis must handle. In this paper we present a new, automated approach for creating static analyzers: instead of manually providing the various inference rules of the analyzer, the key idea is to learn these rules from a dataset of programs. Our method consists of two ingredients: (i) a synthesis algorithm capable of learning a candidate analyzer from a given dataset, and (ii) a counter-example guided learning procedure which generates new programs beyond those in the initial dataset, critical for discovering corner cases and ensuring the learned analysis generalizes to unseen programs. We implemented and instantiated our approach to the task of learning JavaScript static analysis rules for a subset of points-to analysis and for allocation sites analysis. These are challenging yet important problems that have received significant research attention. We show that our approach is effective: our system automatically discovered practical and useful inference rules for many cases that are tricky to manually identify and are missed by state-of-the-art, manually tuned analyzers

    The Merging History of Massive Black Holes

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    We investigate a hierarchical structure formation scenario describing the evolution of a Super Massive Black Holes (SMBHs) population. The seeds of the local SMBHs are assumed to be 'pregalactic' black holes, remnants of the first POPIII stars. As these pregalactic holes become incorporated through a series of mergers into larger and larger halos, they sink to the center owing to dynamical friction, accrete a fraction of the gas in the merger remnant to become supermassive, form a binary system, and eventually coalesce. A simple model in which the damage done to a stellar cusps by decaying BH pairs is cumulative is able to reproduce the observed scaling relation between galaxy luminosity and core size. An accretion model connecting quasar activity with major mergers and the observed BH mass-velocity dispersion correlation reproduces remarkably well the observed luminosity function of optically-selected quasars in the redshift range 1<z<5. We finally asses the potential observability of the gravitational wave background generated by the cosmic evolution of SMBH binaries by the planned space-born interferometer LISA.Comment: 4 pages, 2 figures, Contribute to "Multiwavelength Cosmology", Mykonos, Greece, June 17-20, 200

    Surface climatological information - Twenty selected stations for space shuttle studies

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    Surface climatological data for twenty selected launch, landing, and alternate landing sites for space shuttle syste

    Far-Term Exploration of Advanced Single-Aisle Subsonic Transport Aircraft Concepts

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    Far-term single-aisle class aircraft concepts for potential entry-into-service of 2045 were investigated using an Interactive Reconfigurable Matrix of Alternatives (IRMA) approach. The configurations identified through this design space exploration were then distilled into three advanced aircraft concepts best characterizing the prominent features identified through the IRMA exploration. These three aircraft concepts were then configured and sized for a 150-passenger capacity and a 3,500 nautical mile design mission. Mission block fuel burn was estimated and compared to a far-term conventional configuration baseline concept and a 2005 l. These comparisons suggest considerable potential improvements in fuel efficiency from the investigated advanced concepts

    A New Family of Multistep Methods with Improved Phase Lag Characteristics for the Integration of Orbital Problems

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    In this work we introduce a new family of ten-step linear multistep methods for the integration of orbital problems. The new methods are constructed by adopting a new methodology which improves the phase lag characteristics by vanishing both the phase lag function and its first derivatives at a specific frequency. The efficiency of the new family of methods is proved via error analysis and numerical applications.Comment: 21 pages, 3 figures, 1 tabl
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