59 research outputs found

    Consistent Online Backup in Transactional File Systems

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    The backup taken of a file system must be consistent, preserving data integrity across files in the file system. With file system sizes getting very large, and with demand for continuous access to data, backup has to be taken when the file system is active (is online). Arbitrarily taken online backup may result in an inconsistent backup copy. We propose a scheme referred to as mutual serializability to take a consistent backup of an active file system assuming that the file system supports transactions. The scheme extends the set of conflicting operations to include read-read conflicts, and it is shown that if the backup transaction is mutually serializable with every other transaction individually, a consistent backup copy is obtained. The user transactions continue to serialize within themselves using some standard concurrency control protocol such as Strict 2PL. We put our scheme into a formal framework to prove its correctness, and the formalization as well as the correctness proof are independent of the concurrency control protocol used to serialize user transactions. The scheme has been implemented and experiments show that consistent online backup is possible with reasonable overhead

    Effect of certain indigenous technical knowledge on the management of red spider mite (Oligonychus coffeae) in tea

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    An investigation was carried out at Deha Tea Estate, Jorhat, Assam during 2015-16 by using different indigenous technicalknowledge (ITK) prevalent among different small tea growers. Fish extract at (0.25, 0.5 and 1%), Polygonum hydropiper at (2.5,5 and 7.5%) and Azadirachtin (Neemazal-F 5%) were evaluated in field conditions against tea mite. The result showed that fishextract in combination with cow dung, cow urine and water when sprayed at one per cent concentration, significantly reduced redspider mite population (96.5%), percentage of leaves infestation (5.2%) and leaf area infested by the mite (11.6%). P. hydropiperin combination with cow urine and water when sprayed at 7.5 per cent concentration significantly reduced red spider mitepopulation (87.5%), percentage of infestation (9.1%) and leaf area infested by the mite (12.9%). Among all the ITKs, fish extractat one per cent caused higher reduction of infestation of red spider mite followed by P. hydropiper extract at 7.5 per cent.Influence of both the treatments on the management of red spider mite was at par with that of commercial Azadirachtin

    Systematic review of Ethiopian medicinal plants used for their anti-inflammatory and wound healing activities

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    Ethnopharmacological relevance: Plant materials are used worldwide as complementary and alternative therapeutics for the treatment of various illnesses. In Ethiopia, folk medicines are utilized across a wide range of cultures and settings. Ethiopia has numerous plant species of which around 12% are endemic, making it a rich source of medicinal plants that are potentially important for human wellbeing. Aim of the study: The aim of this study was to assess Ethiopian medicinal plants with anti-inflammatory or wound healing activities, in an attempt to compile the information required for further investigation of their potential role in the management of lymphoedema. Methods: A systematic review protocol was developed according to the preferred reporting items for systematic review and meta-analysis protocols (PRISMA-P) statement. The protocol for this review was registered on PROSPERO with registration number CRD42019127471. This review considers all controlled in vivo and in vitro anti-inflammatory and wound healing studies evaluating the efficacy and safety of Ethiopian medicinal plants. The search strategy included all articles containing descriptors such as Ethiopia, medicinal plants, herbal products, care, management, lymphoedema, lymphedema, swelling, podoconiosis, elephantiasis, wound, wound healing, inflammation, and anti-inflammatory that were published up to June 28, 2019. Outcomes were measured as the percentage of inflammatory and pro-inflammatory cell inhibition, as the percentage of carrageenan-induced oedema (anti-inflammation) inhibition, and the percentage of cell migration and proliferation (wound healing). For quality assessment of individual animal studies, the Risk of Bias tool for animal intervention studies (SYRCLE’s RoB tool) criteria was used. For quality assessment of individual in vitro studies, the OECD guidelines and the WHO Good Laboratory Practice (GLP) handbook were used. Results: A total of 46 articles on anti-inflammatory and 17 articles on wound healing properties were reviewed. For the in vivo studies, Swiss albino mice and Wistar rats were used, and the concentration of plant extracts or fractions administered to the lab animals varied considerably. Acetone extract of Vernonia amygdalina showed the fastest anti-inflammatory activity at lower concentrations in carrageenan-induced paw oedema. Conclusion: Lawsonia inermis, Azadirachta indica, Achyranthes aspera, and Cuminum cyminum are the most studied plant species in terms of anti-inflammatory activity, while Lawsonia inermis and Azadirachta indica are the most studied for wound healing. The most common in vivo techniques used for the anti-inflammatory and the wound healing assays were carrageenan-induced paw oedema, and excision and incision wound models, respectively

    Load balancing inbound traffic in multihomed stub autonomous systems

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    In the Internet, with many competing networks each trying to optimise its own bandwidth, a stub network has limited knowledge about user demands, available network resources and routing policies of other networks. This uncertainty makes the task of interdomain traffic engineering for a stub network very challenging. The basic aim of a stub network connected to multiple ISPs (multihomed) is to load balance its traffic among its various edge links. Our goal in this work is to distribute the incoming traffic of a multihomed stub network among its various edge links. The focus is on networks that primarily download traffic from the Internet. Regulating the incoming traffic is difficult since it will require to influence the behaviour of the remote destinations. We performed a systematic analysis of our problem and showed that even a restricted instance of the problem is NP-complete. We proposed simple, low-cost route control techniques to load balance traffic by reallocating the routes of outgoing traffic. The techniques were validated using synthetic as well as actual data collected under numerous traffic load conditions. Results show that we can achieve significant improvement in load balancing with minimum traffic re-assignments. Moreover, the proposed techniques neither require any third party assistance nor changes to existing protocols and network setup. This makes our schemes easily deployable in real networks

    Consistent Online Backup in Transactional File Systems

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