86,494 research outputs found
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A management architecture for active networks
In this paper we present an architecture for network and applications management, which is based on the Active Networks paradigm and shows the advantages of network programmability. The stimulus to develop this architecture arises from an actual need to manage a cluster of active nodes, where it is often required to redeploy network assets and modify nodes connectivity. In our architecture, a remote front-end of the managing entity allows the operator to design new network topologies, to check the status of the nodes and to configure them. Moreover, the proposed framework allows to explore an active network, to monitor the active applications, to query each node and to install programmable traps. In order to take advantage of the Active Networks technology, we introduce active SNMP-like MIBs and agents, which are dynamic and programmable. The programmable management agents make tracing distributed applications a feasible task. We propose a general framework that can inter-operate with any active execution environment. In this framework, both the manager and the monitor front-ends communicate with an active node (the Active Network Access Point) through the XML language. A gateway service performs the translation of the queries from XML to an active packet language and injects the code in the network. We demonstrate the implementation of an active network gateway for PLAN (Packet Language for Active Networks) in a forty active nodes testbed. Finally, we discuss an application of the active management architecture to detect the causes of network failures by tracing network events in time
Nitrification amplifies the decreasing trends of atmospheric oxygen and implies a larger land carbon uptake
[1] Atmospheric O-2 trend measurements are used to partition global oceanic and land biotic carbon sinks on a multiannual basis. The underlying principle is that a terrestrial uptake or release of CO<sub>2</sub> is accompanied by an opposite flux of O-2. The molar ratio of the CO<sub>2</sub> and O-2 terrestrial fluxes should be 1, if no other elements are considered. However, reactive nitrogen produced by human activities (e.g., fertilizers, N deposition) is also being incorporated into plant tissues. The various reaction pathways of the terrestrial nitrogen cycle cause fluxes of atmospheric O-2. Thus the cycles of nitrogen, carbon, and oxygen must be linked together. We report here on previously unconsidered anthropogenic nitrogen-related mechanisms which impact atmospheric O-2 trends and thus the derived global carbon sinks. In particular, we speculate that anthropogenic-driven changes are driving the global nitrogen cycle to a more oxidized state, primarily through nitrification, nitrate fertilizer industrial production, and combustion of fossil fuels and anthropogenic biomass burning. The sum of these nitrogen-related processes acts to additionally decrease atmospheric O-2 and slightly increase atmospheric CO<sub>2</sub>. We have calculated that the effective land biotic O-2: CO<sub>2</sub> molar ratio ranges between 0.76 and 1.04 rather than 1.10 ( moles of O-2 produced per mole of CO<sub>2</sub> consumed) over the period 1993 - 2003, depending on which of four contrasting nitrogen oxidation and reduction pathway scenarios is used. Using the scenario in which we have most confidence, this implies a 0.23 PgC yr(-1) correction to the global land biotic and oceanic carbon sinks of most recently reported estimates over 1993 - 2003, with the land biotic sink becoming larger and the oceanic sink smaller. We have attributed large uncertainties of 100% to all nitrogen-related O-2 and CO<sub>2</sub> fluxes and this corresponds up to +/- 0.09 PgC yr(-1) increase in global carbon sink uncertainties. Thus accounting for anthropogenic nitrogen-related terrestrial fluxes of O-2 results in a 45% larger land biotic sink of 0.74 +/- 0.78 PgC yr(-1) and a slightly smaller oceanic sink of 2.01 +/- 0.66 PgC yr(-1) for the decade 1993 - 2003. [References: 38
Surgical technique of orthotopic liver transplantation
Athough significant strides have been made in the surgical technique of orthotopic liver transplantation, numerous problems and nuisances are still encountered. Further surgical refinements will certainly evolve. The development of better preservation techniques, the use of intraoperative flowmeters, and the availability of new technologies, such as an artificial liver, should impact and advance the techniques of liver transplantation significantly and improve the overall results even further
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The association of neutrophil-lymphocyte ratio and lymphocyte-monocyte ratio with 3-month clinical outcome after mechanical thrombectomy following stroke
Background and aim
Neutrophil-lymphocyte ratio (NLR) and lymphocyte-monocyte ratio (LMR) are associated with clinical outcomes in malignancy, cardiovascular disease and stroke. Here we investigate their association with outcome after acute ischaemic stroke treated by mechanical thrombectomy (MT).
Methods
Patients were selected using audit data for MT for acute anterior circulation ischaemic stroke at a UK centre from May 2016–July 2017. Clinical and laboratory data including neutrophil, lymphocyte and monocyte count tested before and 24 h after MT were collected. Poor functional outcome was defined as modified Rankin Scale (mRS) of 3–6 at 3 months. Multivariable logistic regression analyses were performed to explore the relationship of NLR and LMR with functional outcome.
Results
One hundred twenty-one patients (mean age 66.4 ± 16.7, 52% female) were included. Higher NLR (adjusted OR 0.022, 95% CI, 0.009–0.34, p = 0.001) and lower LMR (adjusted OR − 0.093, 95% CI (− 0.175)−(− 0.012), p = 0.025) at 24-h post-MT were significantly associated with poorer functional outcome when controlling for age, baseline NIHSS score, infarct size, presence of good collateral supply, recanalisation and symptomatic intracranial haemorrhage on multivariate logistic regression. Admission NLR or LMR were not significant predictors of mRS at 3 months. The optimal cut-off values of NLR and LMR at 24-h post-MT that best discriminated poor outcome were 5.5 (80% sensitivity and 60% specificity) and 2.0 (80% sensitivity and 50% specificity), respectively on receiver operating characteristic curve analysis.
Conclusion
NLR and LMR tested at 24 h after ictus or intervention may predict 3-month functional outcome
Development of a metalised carbon fiber reinforced plastic (CFRP) antenna reflector for satellite communication
The Antenna reflectors made of Carbon Fibre Reinforced Plastics (CFRP) are used in spacecrafts for Satellite Communication in C, S and Ku bands. For futuristic Satellite Communication applications in x2018;Kax2019; band, there is a need of improving the reflectivity for Radio Frequency (RF) signals by metallising the surface of CFRP reflectors. The space qualified CFRP reflectors have been developed by ISRO for various GEOSAT projects but the process for developing a space qualified reflector having a metallized surface has not been established in the country. Recently, efforts in this hither to fore unexplored domain have been made jointly by Space Application Center, Ahemadabad and National Aerospace lab, Bangalore to develop reflectors with metallized surface
Post-9/11 re-orientalism: Confrontation and conciliation in Mohsin Hamid’s and Mira Nair’s The Reluctant Fundamentalist
This article offers a comparative reading of the novel and film adaptation of The Reluctant Fundamentalist, looking at the ways these texts represent changing Western public perceptions towards Pakistan and vice-versa along the temporal axis 2001–2007–2012. Both novel and film are informed by the post-9/11 distrust of the Muslim other. Mohsin Hamid’s novel was begun before 9/11 and published seven years later, in 2007; Mira Nair’s film adaptation followed in 2012, with a premiere at the Venice Film Festival (as the opening film) and the Toronto Film Festival. Ostensibly more conciliatory than Hamid’s novel, Nair’s film adaptation attempts to build bridges, stressing the tragedy of cultural suspicion and mistrust that besets the relationships between Pakistan and the US, endeavouring to open and facilitate dialogue. Despite utilizing spaces of ambiguity to expose the dangers of binary thinking, both novel and film ultimately demonstrate that representations are still unable to escape the loop of orientalism and re-orientalism, highlighting the tension of how East and West continue as locked into this circular mode of relational identity
Environmental life cycle assessment of water supply in South Africa: The Rosslyn industrial area as a case study
Environmental life cycle assessment (LCA) is an environmental management tool, which is increasingly used for decision-support in the South African manufacturing industry, e.g. for cleaner production purposes. The life cycle impact assessment (LCIA) phase of LCAs evaluates the potential environmental impact profiles of industrial activities throughout the life cycles of products and processes. The LCIA procedure is dependent on a comprehensive life cycle inventory (LCI) of the evaluated life cycle system. Water usage is included in LCIs, and is incorporated in LCIA procedures as direct extraction from available resources. However, the environmental burdens associated with water supply extend beyond extraction and include non-renewable energy use, materials use, land use, and pollution of air, soil and water resources. A LCA study was subsequently undertaken to identify key environmental aspects that should be considered where water is used in the manufacturing sector of South Africa, and to identify possible shortcomings in the LCA tool. It is concluded that the extraction of the required water from nature to supply potable water is in fact the most important consideration, and water-losses in the supply system must receive attention, especially in the municipal-controlled part. Water quality impacts are also important, although through supporting processes, and specifically electricity generation. The boosting requirements attribute most to the electricity dependency of the studied life cycle system. However, a number of data gaps were identified and recommendations are made to improve such future LCA studies in South Africa. Water SA Vol. 32(2) 2006: pp.249-25
Biliary tract complications in orthotopic adult liver transplantation: Comparison of anastomotic complications with braided absorbable suture (polyglactin 910) versus a new monofilament absorbable suture (polyglyconate)
Development of a Multi-Objective Genetic Algorithm for the Design of Offshore Renewable Energy Systems
This is the author accepted manuscript. The final version is available from the publisher via the URL in this record.Optimization algorithms have been deployed for a range of renewable energy problems and can successfully be applied to aid in the design of devices, farms, control strategies, and operations and maintenance strategies. Building on this, the present work makes use of a multi-objective genetic algorithm (GA) in order to develop a framework that can further aid in the design and development of offshore renewable energy systems by explicitly taking into account reliability considerations. Though the reliability-based design optimization approach has previously been used in offshore renewable energy applications and multi-objective optimization applications, it has not previously been applied to multi-objective offshore renewable energy design optimization. As the offshore renewable energy sectors grows it is important for the industry to explore more sophisticated methods of designing devices in order to ensure that the device reliability and lifetime can be maximized while downtime and cost are minimized. This paper describes the development of a framework using a GA in order to aid in the design of a mooring system for offshore renewable energy devices. This framework couples numerical models of the mooring system and structural response to both stress-life cumulative damage models and cost models in order for the GA to effectively operate considering the multiple objectives. The use of this multi-objective optimization approach allows multiple design objectives such as system lifetime and cost to be satisfied simultaneously using an automated mathematical approach. From the outputs of this approach, a designer can then select a solution which appropriately balances the different objectives. The developed framework will be applicable to any offshore technology subsystem allowing multi-objective optimization and reliability to be considered from the design stage in order to improve the design efficiency and aid the industry in using more systematic design approaches.This work is funded by the EPSRC (UK) grant for the SuperGen United Kingdom Centre for Marine Energy Research (UKCMER) [grant number: EP/P008682/1]
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