498 research outputs found

    An Evaluation of Journaling File Systems

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    Many statisticians would agree that, had it not been for systems, the synthesis of virtual machines might never have occurred. In fact, few systems engineers would disagree with the improvement of the location-identity split. We motivate an algorithm for the synthesis of compilers, which we call Nap

    Effects of Soil Injection of Liquid Dairy Manure on the Quality of Surface Runoff

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    Liquid dairy manure has been injected on the soil contour to depths of 6 and 12 inches and applied to the surface of a Bluegrass sod and a bare tilled soil. Application rates of 9,250 gallons per acre were used. Runoff from 9-foot-square plots which were sprinkled at rates of 2.5 inches per hour on sod and 1.5 inches per hour on bare soil was collected and analyzed for various pollution parameters including COD, N, TS, TSS, pH, DO, and Fecal Coliform. The effects of pollutant yield in the runoff have been determined for various treatments. Injection of the manure into the soil essentially eliminated any pollutant yield in the runoff from the test plots as compared with surface application. Also, injection tended to even the rate of pollutant loss in the runoff. Increasing the delay-time between application of liquid manure and the simulated rainfall event significantly decreased the yield of pollutants in the runoff. Repeated yearly applications of manure on sod reduced pollutant concentration in runoff and also reduced runoff rates. Test results indicate that pollutant concentration in runoff is a function of the concentration in the liquid manure and the total quantity of runoff

    Multiple Endocrine Neoplasia Type 2B: Eighteen-Year Follow-up of a Four-Generation Family

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    Seven members with multiple endocrine neoplasia type 2B from a 15-member family have been followed for 18 years. All affected had the neuroma phenotype in a distribution compatible with autosomal dominant inheritance. The phenotype features have allowed 100% initial and continuing prediction of affected versus nonaffected status in as early as 1.5 years. Among the affected: immunoreactive plasma calcitonin (iCT) concentration was high in 100%; thyroid palpation was false-negative in 71%; and thyroid scintiscan was false-negative in 83%. All had total thyroidectomy, plus lymphadenectomy in three, for bilateral medullary thyroid carcinoma (MTC) or C-cell hyperplasia (in the youngest). None has died directly from MTC. The index case died at age 68 and his son at age 32 years from complications of the syndrome. All but the youngest have continuing high iCT concentrations. No patient has had parathyroid disease. During preoperative calcium infusion, immunoreactive serum parathyroid hormone concentration declined by 35% to 84% of basal. At operation, macroscopically and microscopically normal parathyroid glands were found in all. No patient has had chemical suggestion of pheochromocytomas: at postmortem the index case had no adrenal medullary disease; his son had bilateral nodular adrenal hyperplasia; his daughter has had adrenal medullary hyperplasia and a renin-secreting juxtaglomerular tumor. Initially nonaffected members remain so

    The Power of Pivoting for Exact Clique Counting

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    Clique counting is a fundamental task in network analysis, and even the simplest setting of 33-cliques (triangles) has been the center of much recent research. Getting the count of kk-cliques for larger kk is algorithmically challenging, due to the exponential blowup in the search space of large cliques. But a number of recent applications (especially for community detection or clustering) use larger clique counts. Moreover, one often desires \textit{local} counts, the number of kk-cliques per vertex/edge. Our main result is Pivoter, an algorithm that exactly counts the number of kk-cliques, \textit{for all values of kk}. It is surprisingly effective in practice, and is able to get clique counts of graphs that were beyond the reach of previous work. For example, Pivoter gets all clique counts in a social network with a 100M edges within two hours on a commodity machine. Previous parallel algorithms do not terminate in days. Pivoter can also feasibly get local per-vertex and per-edge kk-clique counts (for all kk) for many public data sets with tens of millions of edges. To the best of our knowledge, this is the first algorithm that achieves such results. The main insight is the construction of a Succinct Clique Tree (SCT) that stores a compressed unique representation of all cliques in an input graph. It is built using a technique called \textit{pivoting}, a classic approach by Bron-Kerbosch to reduce the recursion tree of backtracking algorithms for maximal cliques. Remarkably, the SCT can be built without actually enumerating all cliques, and provides a succinct data structure from which exact clique statistics (kk-clique counts, local counts) can be read off efficiently.Comment: 10 pages, WSDM 202
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