Task Specific Uncertainty in Coordinate Measurement

Task specific uncertainty is the measurement uncertainty associated with the measurement of a specific feature using a specific measurement plan. This paper surveys techniques developed to model and estimate task specific uncertainty for coordinate measuring systems, primarily coordinate measuring machines using contacting probes. Sources of uncertainty are also reviewed

Effect of Application and Intensity of Bevacizumab-based Maintenance After Induction Chemotherapy With Bevacizumab for Metastatic Colorectal Cancer: A Meta-analysis

BACKGROUND: The administration and intensity of bevacizumab-based maintenance therapy after induction treatment with bevacizumab is still a matter of debate. Thus, the present meta-analysis and an indirect comparison were performed to clarify these issues. PATIENTS AND METHODS: Trials evaluating a separately defined "maintenance phase," with randomization after the induction phase, were selected. Three trials of maintenance with bevacizumab with or without a fluoropyrimidine (CAIRO3, SAKK 41/06, and AIO KRK 0207) were analyzed regarding the effect on progression-free survival (PFS) and overall survival (OS) of any maintenance therapy compared with observation alone and different maintenance intensities (bevacizumab with or without fluoropyrimidine) compared with observation alone and between each other. RESULTS: Maintenance with bevacizumab with or without fluoropyrimidine after bevacizumab-based induction treatment for 4 to 6 months significantly improved PFS (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.43-0.75; P = .0004) and showed a trend toward prolonged OS (HR, 0.89; 95% CI, 0.78-1.02; P = .09) compared with observation alone. The effect on PFS increased with the intensity of the maintenance regimen (HR, 0.72; 95% CI, 0.60-0.85 for single-agent bevacizumab vs. HR, 0.45; 95%, CI 0.39-0.51 for combination therapy, both compared to observation alone). In contrast, the HRs for OS remained in the same range. A similarly improved PFS (HR, 0.63; 95% CI, 0.50-0.79) was shown for the more intensive maintenance therapy (bevacizumab and fluoropyrimidine) compared with bevacizumab alone. CONCLUSION: Bevacizumab-based maintenance therapy after induction chemotherapy with bevacizumab significantly improves PFS and showed a trend toward prolonged OS and should thus be considered, in particular, in patients with a response to induction treatment

Genetic differentiation in Scottish populations of the pine beauty moth Panolis flammea (Lepidoptera: Noctuidae)

Pine beauty moth, Panolis flammea (Denis & Schiffermüller), is a recent but persistent pest of lodgepole pine plantations in Scotland, but exists naturally at low levels within remnants and plantations of Scots pine. To test whether separate host races occur in lodgepole and Scots pine stands and to examine colonization dynamics, allozyme, randomly amplified polymorphic DNA (RAPD) and mitochondrial variation were screened within a range of Scottish samples. RAPD analysis indicated limited long distance dispersal (FST = 0.099), and significant isolation by distance (P < 0.05); but that colonization between more proximate populations was often variable, from extensive to limited exchange. When compared with material from Germany, Scottish samples were found to be more diverse and significantly differentiated for all markers. For mtDNA, two highly divergent groups of haplotypes were evident, one group contained both German and Scottish samples and the other was predominantly Scottish. No genetic differentiation was evident between P. flammea populations sampled from different hosts, and no diversity bottleneck was observed in the lodgepole group. Indeed, lodgepole stands appear to have been colonized on multiple occasions from Scots pine sources and neighbouring populations on different hosts are close to panmixia.A.J. Lowe, B.J. Hicks, K. Worley, R.A. Ennos, J.D. Morman, G. Stone and A.D. Wat

A high accuracy computed water line list

A computed list of H$_{2}$$^{16}$O infra-red transition frequencies and intensities is presented. The list, BT2, was produced using a discrete variable representation two-step approach for solving the rotation-vibration nuclear motions. It is the most complete water line list in existence, comprising over 500 million transitions (65% more than any other list) and it is also the most accurate (over 90% of all known experimental energy levels are within 0.3 cm$^{-1}$ of the BT2 values). Its accuracy has been confirmed by extensive testing against astronomical and laboratory data. The line list has been used to identify individual water lines in a variety of objects including: comets, sunspots, a brown dwarf and the nova-like object V838 Mon. Comparison of the observed intensities with those generated by BT2 enables physical values to be derived for these objects. The line list can also be used to provide an opacity for models of the atmospheres of M-dwarf stars and assign previously unknown water lines in laboratory spectra.Comment: 8 Pages, zero figures. Submitted to MNRAS. On line data at: ftp://cdsarc.u-strasbg.fr/cats/VI/11

On the Development of a New Nonequilibrium Chemistry Model for Mars Entry

This paper represents a summary of results to date of an on-going effort at NASA Ames Research Center to develop a physics-based non-equilibrium model for hypersonic entry into the Martian atmosphere. Our approach is to first compute potential energy surfaces based on accurate solutions of the electronic Schroedinger equation and then use quasiclassical trajectory calculations to obtain reaction cross sections and rate coefficients based on these potentials. We have presented new rate coefficients for N2 dissociation and CO dissociation and exchange reactions. These results illustrate shortcomings with some of the rate coefficients in Parks original T-Tv model for Mars entries and with some of the 30-45 year old shock tube data. We observe that the shock tube experiments of CO + O dissociation did not adequately account for the exchange reaction that leads to formation of C + O2. This reaction is actually the primary channel for CO removal in the shock layer at temperatures below 10,000 K, because the reaction enthalpy for exchange is considerably lower than the comparable value for dissociation

The implications of unconfounding multisource performance ratings

The reliability of job performance ratings is a divisive topic in applied psychology because commonly reported reliability estimates are low and because such reliability estimates are often used to correct validity coefficients (LeBreton, Scherer, & James, 2014). In previous research, attention has been given to the multifaceted nature of multisource job performance ratings. However, measurement-design-relevant effects have been confounded in previous research on this topic. In separate samples from 2 different applications and measurement designs, we unconfounded effects relevant to multisource performance ratings using a Bayesian generalizability theory approach. Our results suggest that the main contributors to reliability in multisource ratings are source-related and general performance effects. Conservative estimates for reliability based on our results were in the range of .81 to .84. We raise questions for future research about corrections for validity coefficients based on criterion unreliability and about reconsidering the measurement design formally applied to multisource ratings

Evolutionary models for low-mass stars and brown dwarfs: uncertainties and limits at very young ages

We analyse pre-Main Sequence evolutionary tracks for low mass stars with masses m \le 1.4 \msol based on the Baraffe et al. (1998) input physics. We also extend the recent Chabrier et al. (2000) evolutionary models based on dusty atmosphere to young brown dwarfs down to one mass of Jupiter. We analyse current theoretical uncertainties due to molecular line lists, convection and initial conditions. Simple tests on initial conditions show the high uncertainties of models at ages \simle 1 Myr. We find a significant sensitivity of atmosphere profiles to the treatment of convection at low gravity and \te < 4000 K, whereas it vanishes as gravity increases. This effect adds another source of uncertainty on evolutionary tracks at very early phases. We show that at low surface gravity (\log g \simle 3.5,) the common picture of vertical Hayashi lines with constant \te is oversimplified. The effect of a variation of initial deuterium abundance is studied. We compare our models with evolutionary tracks available in the literature and discuss the main differences. We finally analyse to which extent current observations of young systems provide a good test for pre-Main Sequence tracks.Comment: 12 pages, Latex file, uses aa.cls, accepted for publication in A&

A new conceptual approach for systematic error correction in CNC machine tools minimizing worst case prediction error

A new artifact-based method to identify the systematic errors in multi-axis CNC machine tools minimizing the worst case prediction error is presented. The closed loop volumetric error is identified by simultaneously moving the axes of the machine tool. The physical artifact is manufactured on the machine tool and later measured on a coordinate measuring machine. The artifact consists of a set of holes in the machine tool workspace at locations that minimize the worst case prediction error for a given bounded measurement error. The number of holes to be drilled depends on the degree of the polynomials used to model the systematic error and the number of axes of the machine tool. The prediction error is also function of the number and location of the holes. The feasibility of the method is first investigated for a two-axis machine to find the best experimental setting. Finally based on the two-axis case study, we extend the results to machine tools with any number of axes. The obtained results are very promising and require only a short time to produce the artifac