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Point System (point + system)
Selected AbstractsMulti-item outcome measures for lateral ligament injury of the ankle: a structured reviewJOURNAL OF EVALUATION IN CLINICAL PRACTICE, Issue 2 2004K.L. Haywood BSc(Hons) DPhil MCSP Abstract Objective, To identify and review evidence relating to the measurement properties of published multi-item outcome measures for the conservative management of lateral ligament injuries of the ankle. Methods, Systematic literature searches were used to identify measures, which were then assessed against pre-defined criteria relating to development, item content, reliability, validity and responsiveness. Results, Seven disease-specific measures of ankle status [Ankle Joint Functional Assessment Tool, Clinical Trauma Severity Score, Composite Inversion Injury Scale, Kaikkonen Functional Scale (KFS), Karlsson Ankle Function Score (KAFS), Olerud and Molander Ankle Score (OMAS), and the Point System] and two generic measures of health (McGill Pain Questionnaire, Sickness Impact Profile) met the review inclusion criteria. While all measures had been used in acute injuries, only two had also been applied during later stages of recovery (>6 months). The studies covered a comprehensive range of graded ligament injuries. Expert opinion dominated item generation for all measures. All measures lack evidence of test-retest or internal consistency reliability in patients with ankle sprain. Several measures were assessed for validity through comparison with other measures, but there was limited evidence of construct validity and no formal assessment of responsiveness for any measure. Conclusion, The disappointing lack of evidence for measurement properties suggests that any measure should be used with caution until appropriate evidence is provided. On the basis of limited evidence, the KFS offers the most promising approach to a combined clinician- and patient-assessment of ankle function, and the KAFS or OMAS if a patient-assessed evaluation of function is required. [source] Characterization of Aspergillus flavus strains from Brazilian Brazil nuts and cashew by RAPD and ribosomal DNA analysisLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2008G.E.O. Midorikawa Abstract Aims:, The aim of this study was to determine the genetic variability in Aspergillus flavus populations from Brazil nut and cashew and develop a polymerase chain reaction (PCR) detection method. Methods and Results:, Chomatography analysis of 48 isolates identified 36 as aflatoxigenic (75%). One hundred and forty-one DNA bands were generated with 11 random amplified polymorphic DNA (RAPD) primers and analysed via unweighted pair group analysis, using arithmetic means (UPGMA). Isolates grouped according to host, with differentiation of those from A. occidentale also according to geographical origin. Aspergillus flavus -specific PCR primers ASPITSF2 and ASPITSR3 were designed from ribosomal DNA internal transcribed spacers (ITS 1 and 2), and an internal amplification control was developed, to prevent false negative results. Specificity to only A. flavus was confirmed against DNA from additional aspergilli and other fungi. Conclusions:, RAPD-based characterization differentiated isolates according to plant host. The PCR primer pair developed showed specificity to A. flavus, with a detection limit of 10 fg. Significance and Impact of the Study:, Genetic variability observed in A. flavus isolates from two Brazilian agroecosystems suggested reproductive isolation. The PCR detection method developed for A. flavus represents progress towards multiplex PCR detection of aflatoxigenic and nonaflatoxigenic strains in Hazard Analysis Critical Control Point systems. [source] Current controversies surrounding liver transplantation for hepatocellular carcinomaJOURNAL OF GASTROENTEROLOGY AND HEPATOLOGY, Issue 7 2010Mauricio F Silva Abstract Liver transplantation (LT) for hepatocellular carcinoma (HCC) has progressed rapidly over the last decade from a futile therapy to the first choice therapy for suitable patients. Excellent outcomes of LT for HCC can be largely attributed to the use of the Milan Criteria, which have restricted LT to patients with early stage tumors. These criteria may be conservative, and it is likely that a subset of patients with tumors beyond these criteria can have acceptable outcomes. However, there is currently insufficient data to accept more liberal criteria as a standard of care, and a higher quality evidence base must be achieved to prevent poor utilization of valuable donor liver resources. In the future, it is probable that more sophisticated selection criteria will emerge incorporating aspects of tumor biology beyond tumor size and number. Dropout from the waiting list due to tumor progression remains a clinical challenge particularly in regions with prolonged waiting times. Priority allocation using HCC MELD points is a practical and transparent solution that has successfully reduced waitlist dropout for HCC patients. Further refinements of the HCC MELD point system are required to ensure equity of access to LT for non-HCC patients and prioritization of HCC patients with the highest risk of dropout. Improving the evidence base for pre-LT locoregional therapy to prevent waitlist dropout is an urgent and difficult challenge for the LT community. In the interim transplant clinicians must restrict the use of these therapies to those patients who are most likely to benefit from them. [source] Efficient algorithms for multiscale modeling in porous mediaNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 5 2010Mary F. Wheeler Abstract We describe multiscale mortar mixed finite element discretizations for second-order elliptic and nonlinear parabolic equations modeling Darcy flow in porous media. The continuity of flux is imposed via a mortar finite element space on a coarse grid scale, while the equations in the coarse elements (or subdomains) are discretized on a fine grid scale. We discuss the construction of multiscale mortar basis and extend this concept to nonlinear interface operators. We present a multiscale preconditioning strategy to minimize the computational cost associated with construction of the multiscale mortar basis. We also discuss the use of appropriate quadrature rules and approximation spaces to reduce the saddle point system to a cell-centered pressure scheme. In particular, we focus on multiscale mortar multipoint flux approximation method for general hexahedral grids and full tensor permeabilities. Numerical results are presented to verify the accuracy and efficiency of these approaches. Copyright © 2010 John Wiley & Sons, Ltd. [source] Analysis of block matrix preconditioners for elliptic optimal control problemsNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 4 2007T. P. Mathew Abstract In this paper, we describe and analyse several block matrix iterative algorithms for solving a saddle point linear system arising from the discretization of a linear-quadratic elliptic control problem with Neumann boundary conditions. To ensure that the problem is well posed, a regularization term with a parameter , is included. The first algorithm reduces the saddle point system to a symmetric positive definite Schur complement system for the control variable and employs conjugate gradient (CG) acceleration, however, double iteration is required (except in special cases). A preconditioner yielding a rate of convergence independent of the mesh size h is described for , , R2 or R3, and a preconditioner independent of h and , when , , R2. Next, two algorithms avoiding double iteration are described using an augmented Lagrangian formulation. One of these algorithms solves the augmented saddle point system employing MINRES acceleration, while the other solves a symmetric positive definite reformulation of the augmented saddle point system employing CG acceleration. For both algorithms, a symmetric positive definite preconditioner is described yielding a rate of convergence independent of h. In addition to the above algorithms, two heuristic algorithms are described, one a projected CG algorithm, and the other an indefinite block matrix preconditioner employing GMRES acceleration. Rigorous convergence results, however, are not known for the heuristic algorithms. Copyright © 2007 John Wiley & Sons, Ltd. [source] In situ extraction of polar product of whole cell microbial transformation with polyethylene glycol-induced cloud point systemBIOTECHNOLOGY PROGRESS, Issue 5 2008Zhilong Wang Abstract A novel polyethylene glycol-induced cloud point system (PEG-CPS) was developed for in situ extraction of moderate polar product by setting a microbial transformation of benzaldehyde into L -phenylacetylcarbinol (L -PAC) with Saccharomyces cerevisiae (baker's yeast) as a model reaction. The biocompatibility of the microorganism in PEG-CPS was comparatively studied with a series of water-organic solvent two-phase partitioning systems. The tolerance of microorganism to the toxic substrate benzaldehyde was increased and the moderate polar product L -PAC was extracted into the surfactant-rich phase in the PEG-CPS. The novel PEG-CPS fills the gap of in situ extraction of polar product in microbial transformation left by water-organic solvent two-phase partitioning system. At the same time, the application of PEG-CPS in a microbial transformation also avoids expensive solvent when compared with that of aqueous two-phase system or CPS. [source] Re-calibration and external validation of an existing nomogram to predict aggressive recurrences after radical prostatectomyBJU INTERNATIONAL, Issue 12 2010Florian R. Schroeck Study Type , Prognosis (case series) Level of Evidence 4 OBJECTIVE To re-calibrate the previously published Duke Prostate Center (DPC) nomogram for the prediction of biochemical recurrence (BCR) after radical prostatectomy (RP) to not only predict overall BCR but also the clinically more relevant endpoint of an aggressive recurrence (i.e. a BCR with a postoperative PSA doubling time (PSADT) of <9 months). PATIENTS AND METHODS Using the established point-scale system based upon the previously published DPC nomogram, we re-calibrated this point system to predict not just BCR, but also aggressive BCR within 2599 men treated with RP from the DPC database. PSADT was computed on all patients meeting the recurrence definition who had a minimum of two PSA values, separated by at least 3 months, and ,2 years after recurrence. External validation was performed using data from 1695 men treated with RP within the Shared Equal Access Regional Cancer Hospital (SEARCH) database by calculating the concordance index c and by plotting calibration curves. RESULTS The median follow-up for patients with no BCR was 56 and 47 months for DPC and SEARCH, respectively. In the DPC modelling cohort and the SEARCH validation cohort, 645 (25%) and 557 (33%) men had BCR, while 83 (3.2%) and 71 (4.2%) patients had an aggressive recurrence. In external validation, predictive accuracy for an aggressive BCR was high (c = 0.83) and the nomogram showed good calibration. CONCLUSIONS We re-calibrated an existing nomogram to not only predict overall BCR after RP but also aggressive recurrence after RP. Our new tool can provide valuable information for patient counselling and patient selection for adjuvant therapy trials. [source] Efficient preconditioning techniques for finite-element quadratic discretization arising from linearized incompressible Navier,Stokes equationsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS, Issue 12 2010A. El Maliki Abstract We develop an efficient preconditioning techniques for the solution of large linearized stationary and non-stationary incompressible Navier,Stokes equations. These equations are linearized by the Picard and Newton methods, and linear extrapolation schemes in the non-stationary case. The time discretization procedure uses the Gear scheme and the second-order Taylor,Hood element P2,P1 is used for the approximation of the velocity and the pressure. Our purpose is to develop an efficient preconditioner for saddle point systems. Our tools are the addition of stabilization (penalization) term r,(div(·)), and the use of triangular block matrix as global preconditioner. This preconditioner involves the solution of two subsystems associated, respectively, with the velocity and the pressure and have to be solved efficiently. Furthermore, we use the P1,P2 hierarchical preconditioner recently proposed by the authors, for the block matrix associated with the velocity and an additive approach for the Schur complement approximation. Finally, several numerical examples illustrating the good performance of the preconditioning techniques are presented. Copyright © 2009 John Wiley & Sons, Ltd. [source] Augmentation block preconditioners for saddle point-type matrices with singular (1, 1) blocksNUMERICAL LINEAR ALGEBRA WITH APPLICATIONS, Issue 6 2008Zhi-Hao Cao Abstract We consider the use of block preconditioners for the application of the preconditioned Krylov subspace iterative methods to the solution of large saddle point-type systems with singular (1, 1) blocks. Two block triangular preconditioners are introduced and the block diagonal preconditioner in Greif and Schötzau (Electron. Trans. Numer. Anal. 2006; 22:114,121) is extended to nonsymmetric saddle point systems. All these preconditioners are based on augmentation, using nonsingular weight matrices. If the nullity of the (1, 1) block takes its highest possible value, the preconditioned matrix with either block triangular preconditioner has precisely three distinct eigenvalues, and the preconditioned matrix with the block diagonal preconditioner has precisely two distinct eigenvalues, giving rise to immediate convergence of preconditioned GMRES. Finally, numerical experiments that validate the analysis are reported. Copyright © 2008 John Wiley & Sons, Ltd. [source] False-positive liquid chromatography/tandem mass spectrometric confirmation of sebuthylazine residues using the identification points system according to EU directive 2002/657/EC due to a biogenic insecticide in tarragonRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2009Andreas Schürmann In pesticide residue analysis using liquid chromatography/tandem mass spectrometry (LC/MS/MS) the confirmation of a sebuthylazine finding in a tarragon (Artemisia dranunculus) sample was demonstrated to be false positive. A coeluting interfering matrix compound produced product ions in MS/MS analysis, perfectly corresponding to the multiple reaction monitoring (MRM) of two sebuthylazine transitions. Using the EU directive 2002/657/EC which regulates the confirmation of suspected positive findings would have resulted in a false-positive finding. A third LC/MS/MS transition with a deviant ion ratio and a gas chromatography (GC)/MS/MS analysis revealed the false-positive results. With optimized high resolving ultra-performance liquid chromatography (UPLC) conditions it was possible to separate spiked sebuthylazine from the interfering matrix compound. Using its exact mass and isotope ratios from LC/time-of-flight (TOF) MS measurements, the compound was identified as nepellitorine, a , not surprising , endogenous alkamide in tarragon (Arthemisia dranunculus). False-positive results, especially in heavy matrix samples such as herbs, can be dealt with by further confirmatory analysis, e.g. a third transition, GC analysis if possible or more advantageous by an orthogonal criterion like exact mass. Copyright © 2009 John Wiley & Sons, Ltd. [source] | |||||||||||||