They are very suitable for xenografts of human cell lines. The NOD/SCID model combines multiple functional defects of adaptive and innate immunity. The NOD strain is characterized by functional deficits in NK cells, an absence of circulating complement and defects in the differentiation and function of antigen-presenting cells. described a new immuno-deficient mouse model, the NOD/SCID, obtained by crossing the SCID and NOD mouse strains. Homozygotes lack both B and T cells but have normal numbers of natural killer (NK) cells, the main effectors of non-MHC restricted immunity. The murine recessive SCID mutation on chromosome 16 arose in the CB-17 inbred strain (BALB/c.C57BL/Ka-Igh-1b). The lack of the thymus leads to many defects of the immune system, including a greatly reduced population of T lymphocytes. Homozygotes (nu/nu) are hairless from birth and completely lack a thymus due to a failure of development of the thymic cells at the embryonic stage. The murine recessive nude mutation on chromosome 11 arose spontaneously. Some commonly used strains of immuno-deficient mice include the nude mouse, the severe combined immune deficiency (SCID) mouse and the NOD/SCID mouse (non-obese diabetic/SCID). The extent to which some of these mutations interfere with immune function can also vary with the genetic background. The various mouse mutants have differing immunological properties. Genetic loci affecting immune responses include nu (nude), SCID (severe combined immunodeficiency), beige, and xid (X-linked immunodeficiency). A variety of genetic mutations are known that impair immune function in mice. These mice have a limited capacity for rejecting foreign tissue, which makes them excellent recipients for xenografts of human cells and tissues. Immuno-deficient mice are routinely used in research. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Ĭompeting interests: The authors have declared that no competing interests exist. VE is supported by a fellowship from the Canadian Breast Cancer Foundation – Ontario Region. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.įunding: Funding for this study was provided by the Canadian Cancer Society Research Institute (Grant # 19397). Received: JAccepted: OctoPublished: November 9, 2011Ĭopyright: © 2011 Economopoulos et al. Stoddart, University of California, San Francisco, United States of America This is important to recognize in order to avoid the misinterpretation of MRI findings as abnormal when these strains are used in MRI imaging studies.Ĭitation: Economopoulos V, Noad JC, Krishnamoorthy S, Rutt BK, Foster PJ (2011) Comparing the MRI Appearance of the Lymph Nodes and Spleen in Wild-Type and Immuno-Deficient Mouse Strains. The MRI appearance of the normal lymph nodes and spleen varies considerably in the various mouse strains examined in this study. Spleens of SCID and NOG mice were significantly smaller (p<0.0001) and abnormal in appearance. The spleens of C57Bl/6 and nude mice were similar in size and appearance. Lymph node volumes changed slightly over time in all strains. Nodes in SCID mice were smaller than in nude or C57Bl/6 mice (p<0.0001). Volumes of the nodes were highly variable in nude mice. In images of nude and SCID mice, lymph nodes sometimes contained a hyperintense region visible on MRI images. The volume of the lymph nodes and spleens were measured from MR images. Images were acquired with a 3D balanced steady state free precession (bSSFP) sequence. Four mice from each of four different mouse strains (nude, NOG, C57BL/6, CB-17 SCID (SCID)) were imaged weekly for one month. The goal of this study was to investigate the normal MRI appearance of lymphoid organs in immuno-competent and immuno-deficient mice commonly used in research.
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For HyperGraphQL, the emphasis is on providing an alternative for SPARQL that would be easier to work with for developers, while shifting the complexity of federated querying that SPARQL provides from the query level into the GraphQL server. Klarman does not have much to add there, as ORMs for RDF graph databases do not exist (although other APIs to access them do). Read also: TigerGraph, a graph database born to roar We have to note, however, that ORMs if nothing else have been around for longer, so we can expect them to be more mature. And it does make sense that batching a lot of queries would be more efficient than handling each one separately. So, both Gillam and Schickling seem aligned here. GraphQL, when used well, enables clients to easily eradicate these under-fetching and over-fetching woes." ORMs also tend to over-fetch data - fetching columns or even whole rows that won't be needed. This leads to frequent alternation between data fetching and code execution, causing increased latency and heavier load on various parts of the infrastructure, increasing the need for caching. PostGraphile does this by turning your GraphQL query into a single SQL query, leading to very efficient linear execution: Receive request, build SQL, execute SQL, send response.īy contrast, ORMs typically don't 'know' what data they need up front - they discover their needs a bit at a time as the code reaches the relevant points during execution. "This enables a sophisticated execution layer to understand all the requirements and resolve the request in the most efficient manner. Gillam also said he does not think of PostGraphile, or GraphQL in general, as an ORM, but more as a "declarative data fetcher." GraphQL, he added, operates in terms of the "big picture" - the client declares the full shape of the data/relations that it needs up front, then requests the full result set in one payload: "Getting your JSON-LD should be simple" is HyperGraphQL's motto, but it applies to connecting to your database more broadly. This allows Prisma to perform optimizations not normally possible for an ORM that is embedded in the application." Schickling said, "Prisma is different from an ORM in that it is a dedicated infrastructure component. In a recent post, Prisma claimed that "existing ORMs are too limited and inefficient." For someone not very familiar with GraphQL for databases, this begs the question: How are existing ORMs limited and inefficient, and what makes GraphQL for databases better? So, how similar are those GraphQL access layers to an ORM? ORMs let developers map tables in relational databases to domain objects, thus making it easier to work at a higher abstraction level, and offering a hub for database access that can add services such as caching to the mix. Is GraphQL for databases a glorified object-relational mapping layer?įor anyone familiar with object-relational mapping (ORM), the idea of adding a layer between the database and applications that use it should be familiar. There is another effort in this area, Hasura, but its people did not respond to requests for comment. HyperGraphQL works with RDF graph databases, was developed as an open-source project during Klarman's stint with Semantic Integration Ltd, and is in somewhat of a flux at the moment. Prisma works with MySQL, Postgres, and MongoDB, has more in its list, and just raised $4.5 million in a seed round. In a nutshell, PostGraphile works with Postgres, and is what Gillam's work is focused on, supported by Patreon and PostGraphile-related consulting work. Read also: AWS Neptune going GA: The good, the bad, and the ugly And third, to equip GraphQL with easy means of querying-linked data." Second, to facilitate federation of and querying across distributed linked data sources and services within the GraphQL framework. First, to equip the Semantic Web stack with a GraphQL-based query interface. Szymon Klarman, HyperGraphQL's original architect, said: "The motivation for HyperGraphQL comes down primarily to three goals. As an open-source project, Prisma allows companies to start out with advanced technology that grows with them as they start building out a more advanced infrastructur." Johannes Schickling, Prisma's co-founder, said: "The right way to think about Prisma is as a productized version of the data layer implemented at large companies such as Twitter, Airbnb, and Facebook. Providence and Airbridge Investments continued to be significant minority shareholders of M7.Ĭommenting on the acquisition by Canal+, Charles-Hubert le Baron, at Astorg said: “Since our cooperation with M7 in 2014, the company has continued to expand its business rapidly in Eastern Europe, while further upselling its subscriber base across all geographies. In September 2014 the investment firm acquired a majority stake in M7, from an investor group led by Providence Equity Partners. M7 is owned by private equity firm Astorg Partners. At the end of the transaction, the Canal+ Group will hold almost 20 million subscribers worldwide, including 12 million in Europe. Between them the operations have 3 million subscribers to hybrid satellite / OTT Pay TV packages with 800,000 subscribing to an basic access package. M7 has operations in Belgium (TV Vlaanderen and TéléSat), the Netherlands (CanalDigitaal and ), Austria (HD Austria), Skylink in the Czech Republic and Slovakia, Hungary and Romania, and M7 Germany in Germany. This major acquisition would allow us to reinforce our distribution capacity and to spread more widely the contents of our catalog and our numerous production activities in Europe.” Our global subscriber base will have almost doubled in five years, with a clear acceleration since 2015. The operation would allow Canal+ Group to approach the 20 million subscribers worldwide. Maxime Saada, Chairman of the Canal+ Group Executive Board, said: “We are particularly pleased with this acquisition project achieved thanks to Vivendi’s full support. In a statement, Canal said the acquisition price would be set at just over €1 billion, based on a turnover of more than €400 million. Canal+ has acquired the Luxembourg-based M7, which operates a series of independent pay-TV platforms across the Benelux and Central Europe. |