124 research outputs found

    An efficient method to avoid path lookup in file access auditing in IO path to improve file system IO performance

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    One of the biggest challenges in metadata management schemes that sit outside the filesystem layer is their ability to index meaningful path information of files that are being referenced in an external system like a database or in a metadata journal file. Path to a file is a critical requirement that allows both meaningful interpretation of the locality of the file and its metadata and also secondly allows for more efficient user mode services that can transform the file or its metadata. Additionally path information is very essential in compliance systems where audit logs need to tell what happened to a file and where it is located. However when the data path is being audited from layers such as protocols, it becomes harder to reconstruct the entire path information for all the files given that the protocol layers do not directly integrate with the underlying Filesystem. The protocol layers would then need to rely on system cache to get the path data and sometimes this may not be possible making it required for the protocol to actually do an expensive reverse path walk, reconstructing the path. This actually heavily degrades the performance of the system. In this paper we discuss a mechanism that allows us to record enough information about the file using the unique ID of itself and its parent in the protocol layer such that if and when required the path information can be reconstructed based on a reliable reverse lookup in a database or a file based journal system. The idea is to have enough information to reconstruct the path at a later time and outside the system where the information was initially originated from. The paper also talks of keeping this system consistent under all conditions

    Atypical presentation of intra-articular osteochondroma of knee in adolescent- case report

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    Osteochondroma is most common benign bone tumor around knee joint. They occur during the period of growth, grows away from joint line and rarely responsible for mechanical symptoms. This paper reports a rare presentation of intra-articular osteochondroma in knee with mechanical instability symptoms, mild to moderate pain and swelling of knee joint. Patient was 20 years old male and misdiagnosed as chronic nonspecific synovitis, tubercular arthritis and anterior cruciate ligament tear of knee. We assessed him clinically and radiologically and diagnosis was established based on MRI and arthroscopy. He was treated by open excision of tumor, and patients recover uneventfully. Instability of knee joint in this case can be attributed due to rough surface of osteochondroma just beneath lower attachment of patellar tendon

    Rational engineering of Kluyveromyces marxianus to create a chassis for the production of aromatic products

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    Background: The yeast Kluyveromyces marxianus offers unique potential for industrial biotechnology because of useful features like rapid growth, thermotolerance and a wide substrate range. As an emerging alternative platform, K. marxianus requires the development and validation of metabolic engineering strategies to best utilise its metabolism as a basis for bio-based production. Results: To illustrate the synthetic biology strategies to be followed and showcase its potential, we describe a comprehensive approach to rationally engineer a metabolic pathway in K. marxianus. We use the phenylalanine biosynthetic pathway both as a prototype and because phenylalanine is a precursor for commercially valuable secondary metabolites. First, we modify and overexpress the pathway to be resistant to feedback inhibition so as to overproduce phenylalanine de novo from synthetic minimal medium. Second, we assess native and heterologous means to increase precursor supply to the biosynthetic pathway. Finally, we eliminate branch points and competing reactions in the pathway and rebalance precursors to redirect metabolic flux to a specific product, 2-phenylethanol (2-PE). As a result, we are able to construct robust strains capable of producing over 800 mg L-1 2-PE from minimal medium. Conclusions: The strains we constructed are a promising platform for the production of aromatic amino acid-based biochemicals, and our results illustrate challenges with attempting to combine individually beneficial modifications in an integrated platform
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