2,475 research outputs found
Decision making from economic and signal detection perspectives: development of an integrated framework
Optimal discrete stopping times for reliability growth tests
Often, the duration of a reliability growth development test is specified in advance and the decision to terminate or continue testing is conducted at discrete time intervals. These features are normally not captured by reliability growth models. This paper adapts a standard reliability growth model to determine the optimal time for which to plan to terminate testing. The underlying stochastic process is developed from an Order Statistic argument with Bayesian inference used to estimate the number of faults within the design and classical inference procedures used to assess the rate of fault detection. Inference procedures within this framework are explored where it is shown the Maximum Likelihood Estimators possess a small bias and converges to the Minimum Variance Unbiased Estimator after few tests for designs with moderate number of faults. It is shown that the Likelihood function can be bimodal when there is conflict between the observed rate of fault detection and the prior distribution describing the number of faults in the design. An illustrative example is provided
From Yang-Mills Lagrangian to MHV Diagrams
We prove the equivalence of a recently suggested MHV-formalism to the
standard Yang-Mills theory. This is achieved by a formally non-local change of
variables. In this note we present the explicit formulas while the detailed
proofs are postponed to a future publication.Comment: Latex,11 pages, minor changes, reference added, version to appear in
JHE
Reply to: "Variables in the effect of land use on soil extrapore enzymatic activity and carbon stabilization" by Glenn (2020)
SUSY Ward identities for multi-gluon helicity amplitudes with massive quarks
We use supersymmetric Ward identities to relate multi-gluon helicity
amplitudes involving a pair of massive quarks to amplitudes with massive
scalars. This allows to use the recent results for scalar amplitudes with an
arbitrary number of gluons obtained by on-shell recursion relations to obtain
scattering amplitudes involving top quarks.Comment: 22 pages, references adde
Prevalence of renal impairment and use of nephrotoxic agents among patients with bone metastases from solid tumors in the United States
The renal status of patients with bone metastases secondary to solid tumors and their treatment with nephrotoxic agents is not well characterized. This retrospective study analyzed electronic medical records data from USâbased oncology clinics to identify adult (age â„18) solid tumor patients with first bone metastasis diagnosis and â„1 serum creatinine recorded between January 1, 2009 and December 31, 2013. Patients with multiple myeloma, multiple primary tumor types, acute renal failure, and/or endâstage renal disease were excluded. Using the Chronic Kidney Disease Epidemiology Collaboration formula, we determined the prevalence of renal impairment (RI: single estimated glomerular filtration rate [eGFR] value <60Â mL/min per 1.73Â m2) and chronic kidney disease (CKD: â„2 eGFR values <60, at least 90Â days apart). We also examined the use of intravenous bisphosphonates (IV BP) and other nephrotoxic agents. Approximately half of the 11,809 patients were female. Breast (34%) and lung (28%) tumors were the most common. At bone metastasis diagnosis, mean age was 67Â years and 24% of patients exhibited RI. The 5âyear prevalence was 43% for RI and 71% for CKD among RI patients. Nearly half (46%) of CKD patients received IV BP in the 12Â months following their confirming eGFR and 13% of these patients received at least one other nephrotoxic agent during that period. This is the first USâbased study to examine the prevalence of RI among patients with bone metastases from solid tumors. RI is common at bone metastases diagnosis, and a substantial proportion of patients develop RI or CKD as their disease progresses. Whenever possible, treatments that are potentially less damaging for the kidney should be considered for patients with or predisposed to RI.In patients with bone metastases secondary to solid tumors, the 5âyear prevalence was 43% for renal impairment (RI) and 71% for chronic kidney disease among evaluable RI patients. Whenever possible, treatments that are potentially less damaging for the kidney should be considered for patients with or predisposed to RI.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111794/1/cam4403.pd
Honeybee linguisticsĂąâŹâa comparative analysis of the waggle dance among species of Apis
All honeybees use the waggle dance to recruit nestmates. Studies on the dance precision of Apis mellifera have shown that the dance is often imprecise. Two hypotheses have been put forward aimed at explaining this imprecision. The first argues that imprecision in the context of foraging is adaptive as it ensures that the dance advertises the same patch size irrespective of distance. The second argues that the bees are constrained in their ability to be more precise, especially when the source is nearby. Recent studies have found support for the latter hypothesis but not for the âtuned-errorâ hypothesis, as the adaptive hypothesis became known. Here we investigate intra-dance variation among Apis species. We analyse the dance precision of A. florea, A. dorsata, and A. mellifera in the context of foraging and swarming. A. mellifera performs forage dances in the dark, using gravity as point of reference, and in the light when dancing for nest sites, using the sun as point of reference. Both A. dorsata and A. florea are open-nesting species; they do not use a different point of reference depending on context. A. florea differs from both A. mellifera and A. dorsata in that it dances on a horizontal surface and does not use gravity but instead âpointsâ directly toward the goal when indicating direction. Previous work on A. mellifera has suggested that differences in dance orientation and point of reference can affect dance precision. We find that all three species improve dance precision with increasing waggle phase duration, irrespective of differences in dance orientation, and point of reference. When dancing for sources nearby, dances are highly variable. When the distance increases, dance precision converges. The exception is dances performed by A. mellifera on swarms. Here, dance precision decreases as the distance increases. We also show that the size of the patch advertised increases with increasing distance, contrary to what is predicted under the tuned-error hypothesis
A direct proof of the CSW rules
Using recursion methods similar to those of Britto, Cachazo, Feng and Witten
(BCFW) a direct proof of the CSW rules for computing tree-level gluon
amplitudes is given.Comment: 11 pages, uses axodraw.st
MHV-Vertices for Gravity Amplitudes
We obtain a CSW-style formalism for calculating graviton scattering
amplitudes and prove its validity through the use of a special type of
BCFW-like parameter shift. The procedure is illustrated with explicit examples.Comment: 21 pages, minor typos corrected, proof added in section
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