FishMark: A Linked Data Application Benchmark

Abstract. FishBase is an important species data collection produced by the FishBase Information and Research Group Inc (FIN), a not-forprofit NGO with the aim of collecting comprehensive information (from the taxonomic to the ecological) about all the world’s finned fish species. FishBase is exposed as a MySQL backed website (supporting a range of canned, although complex queries) and serves over 33 million hits per month. FishDelish is a transformation of FishBase into LinkedData weighing in at 1.38 billion triples. We have ported a substantial number of FishBase SQL queries to FishDelish SPARQL query which form the basis of a new linked data application benchmark (using our derivative of the Berlin SPARQL Benchmark harness). We use this benchmarking framework to compare the performance of the native MySQL application, the Virtuoso RDF triple store, and the Quest OBDA system on a fishbase.org like application.

Valence Fluctuations Revealed by Magnetic Field Scan: Comparison with Experiments in YbXCu_4 (X=In, Ag, Cd) and CeYIn_5 (Y=Ir, Rh)

The mechanism of how critical end points of the first-order valence transitions (FOVT) are controlled by a magnetic field is discussed. We demonstrate that the critical temperature is suppressed to be a quantum critical point (QCP) by a magnetic field. This results explain the field dependence of the isostructural FOVT observed in Ce metal and YbInCu_4. Magnetic field scan can lead to reenter in a critical valence fluctuation region. Even in the intermediate-valence materials, the QCP is induced by applying a magnetic field, at which the magnetic susceptibility also diverges. The driving force of the field-induced QCP is shown to be a cooperative phenomenon of the Zeeman effect and the Kondo effect, which creates a distinct energy scale from the Kondo temperature. The key concept is that the closeness to the QCP of the FOVT is capital in understanding Ce- and Yb-based heavy fermions. It explains the peculiar magnetic and transport responses in CeYIn_5 (Y=Ir, Rh) and metamagnetic transition in YbXCu_4 for X=In as well as the sharp contrast between X=Ag and Cd.Comment: 14 pages, 9 figures, OPEN SELECT in J. Phys. Soc. Jp

Adjunctive rifampicin to reduce early mortality from Staphylococcus aureus bacteraemia: the ARREST RCT

Background: Around 12,500 cases of Staphylococcus aureus bacteraemia occur each year in the United Kingdom, with an associated mortality of about 30%, yet the evidence guiding optimum management is poor. We hypothesise that adjunctive rifampicin will enhance killing of Staphylococcus aureus early in the course of antibiotic treatment of bacteraemia, sterilise infected foci and blood faster, and thereby reduce the risk of dissemination, metastatic infection and death. Design: A randomised, blinded, placebo controlled trial. Eligible patients will be randomised to two parallel arms in a 1:1 ratio: standard intravenous antibiotic therapy of the attending physician's choice plus either 14 days of placebo or rifampicin (900mg/24hrs if >60kg; 600mg/24hrs if <60kg). Setting: 29 large acute NHS Trusts. Target population: All adults (=18 years) with a pure culture of S. aureus (meticillin-susceptible or resistant) grown from their blood will be eligible. Patients will be excluded if they have received >96 hours of active antibiotic therapy for the current infection. Outcome measurements: The primary outcome will be death or bacteriological failure (microbiologically confirmed treatment failure or disease recurrence) by 12 weeks from randomisation. The secondary endpoints will include all-cause mortality through 14 days; duration of bacteraemia; death or clinically defined treatment failure or disease recurrence by 12 weeks adjudicated by an independent endpoint committee blind to treatment allocation; the development of rifampicin resistant S. aureus; modification of any drug treatment due to drug interactions; and serious adverse events and reactions. Healthcare-related resource use and EQ-5D will be collected during the trial to determine the cost-effectiveness of rifampicin for S. aureus bacteraemia treatment in the NHS. Sample size: Current data indicate 16% and 24% of all cases of S. aureus bacteraemia die by 14 days and 12 weeks respectively; a further 10% of patients have repeat isolation of S. aureus over the 12 weeks following initial bacteraemia. Assuming at least 80% power, two-sided alpha 0.025, and a 10% loss to follow-up by 12 weeks, we would need to randomise 940 patients to detect a 30% relative reduction in death/bacteriological failure by 12 weeks and a 45% reduction in death by 14 days. Sample size re-calculation in protocol version 5.0: With 12-week bacteriological failure/recurrence or death as the sole primary endpoint, the total sample size is now 770 patients (alpha=0.05, other assumptions as above)