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Method Capable (method + capable)
Selected AbstractsInterobserver and Intraobserver Variability of Flow-Mediated Vasodilatation of the Brachial ArteryECHOCARDIOGRAPHY, Issue 1 2008Iana Simova M.D. Flow-mediated endothelial-dependent vasodilatation (FMD) of the brachial artery is a method capable of detecting endothelial dysfunction. In order to implement this method in future clinical research studies, its reproducibility and precision have to be assessed. The aim of the study is to evaluate the inter- and intraobserver variability of FMD performed in our department. We investigate 40 patients. FMD is measured by two independent observers to test the interobserver variability, and repeated by the first observer to test the intraobserver variability. We compare the baseline and post-ischemic diameter of the brachial artery and the percent dilatation. The correlation coefficients for these comparisons are high (>0.92) with a significance of less than 0.001. The inter- and intraobserver variability is further tested comparing the mean values of the baseline and post ischemic diameter of the brachial artery and the percent dilatation. The absolute values of the mean paired differences and the standard deviations (SDs) of the differences are 0.02850 ± 0.05942, P = 0.004, 0.01175 ± 0.08177, P = 0.369 and 0.28375 ± 1.61561, P = 0.273, respectively for the interobserver variability and 0.00475 ± 0.04663, P = 0.523, 0.00050 ± 0.05267, P = 0.952 and 0.15725 ± 1.19922, P = 0.412, respectively for the intraobserver variability. It can be concluded that the inter- and intraobserver variability for FMD performed in our department is acceptable. FMD can be performed precisely and accurately, with a satisfactory reproducibility and can be safely and reliably implemented in future clinical research studies. [source] Use of multiplex real-time PCR (TaqMan) for the detection of potato viruses,EPPO BULLETIN, Issue 3-4 2000N. Boonham Certain viruses affect the quality of potato tubers for either table use or processing. Visual discrimination of these viruses is problematic because of variable symptoms, but is important if proper controls are to be implemented. Work at the Central Science Laboratory has concentrated on the detection of Potato mop-top pomovirus (PMTV), Tobacco rattle tobravirus (TRV) (both associated with the disease spraing) and the tuber necrotic strain of Potato Y potyvirus (PVYNTN), the symptoms of which can often be confused with spraing. A nucleic acid-based approach has been adopted as TRV is often found as naked RNA with no associated coat protein, and accurate discrimination of PVY strains is impossible by serology. The multiplex TaqMan assay developed in this work streamlines the testing, replacing two separate tests currently used (a TRV RT-PCR and a PMTV enzyme-linked immunosorbent assay) with a single-tube assay, which has no post-PCR manipulations. The assay has been shown to be more sensitive than either of the tests which it replaces, allowing 100- and 10000-fold increases in sensitivity for TRV and PMTV detection respectively. The test reliably detected over 40 different isolates of TRV and PMTV obtained from a wide range of cultivars and locations, including samples where existing tests failed. A PCR-based method capable of discriminating strains of PVY was also developed. [source] A moving-mesh finite-volume method to solve free-surface seepage problem in arbitrary geometriesINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 14 2007M. Darbandi Abstract The main objective of this work is to develop a novel moving-mesh finite-volume method capable of solving the seepage problem in domains with arbitrary geometries. One major difficulty in analysing the seepage problem is the position of phreatic boundary which is unknown at the beginning of solution. In the current algorithm, we first choose an arbitrary solution domain with a hypothetical phreatic boundary and distribute the finite volumes therein. Then, we derive the conservative statement on a curvilinear co-ordinate system for each cell and implement the known boundary conditions all over the solution domain. Defining a consistency factor, the inconsistency between the hypothesis boundary and the known boundary conditions is measured at the phreatic boundary. Subsequently, the preceding mesh is suitably deformed so that its upper boundary matches the new location of the phreatic surface. This tactic results in a moving-mesh procedure which is continued until the nonlinear boundary conditions are fully satisfied at the phreatic boundary. To validate the developed algorithm, a number of seepage models, which have been previously targeted by the other investigators, are solved. Comparisons between the current results and those of other numerical methods as well as the experimental data show that the current moving-grid finite-volume method is highly robust and it provides sufficient accuracy and reliability. Copyright © 2007 John Wiley & Sons, Ltd. [source] The modelling of anchors using the material point methodINTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS, Issue 9 2005C. J. Coetzee Abstract The ultimate capacity of anchors is determined using the material point method (MPM). MPM is a so-called meshless method capable of modelling large displacements, deformations and contact between different bodies. A short introduction to MPM is given and the derivation of the discrete governing equations. The analysis of a vertically loaded anchor and one loaded at 45° is presented. The load,displacement curves are compared to that obtained from experiments and the effect of soil stiffness and anchor roughness is investigated. The results of the vertically loaded anchor are also compared to an analytical solution. The displacement of the soil surface above the anchor was measured and compared to the numerical predictions. Convergence with mesh refinement is demonstrated and the effect of mesh size and dilatancy angle on the shear band width and orientation is indicated. The results show that MPM can model anchor pull out successfully. No special interface elements are needed to model the anchor,soil interface and the predicted ultimate capacities were within 10% of the measured values. Copyright © 2005 John Wiley & Sons, Ltd. [source] Pattern hunting in climate: a new method for finding trends in gridded climate dataINTERNATIONAL JOURNAL OF CLIMATOLOGY, Issue 1 2007A. Hannachi Abstract Trends are very important in climate research and are ubiquitous in the climate system. Trends are usually estimated using simple linear regression. Given the complexity of the system, trends are expected to have various features such as global and local characters. It is therefore important to develop methods that permit a systematic decomposition of climate data into different trend patterns and remaining no-trend patterns. Empirical orthogonal functions and closely related methods, widely used in atmospheric science, are unable in general to capture trends because they are not devised for that purpose. The present paper presents a novel method capable of systematically capturing trend patterns from gridded data. The method is based on an eigenanalysis of the covariance/correlation matrix obtained using correlations between time positions of the sorted data, and trends are associated with the leading nondegenerate eigenvalues. Application to simple low-dimensional time series models and reanalyses data are presented and discussed. Copyright © 2006 Royal Meteorological Society. [source] Coverage path planning algorithms for agricultural field machinesJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 8 2009Timo Oksanen In this article, a coverage path planning problem is discussed in the case of agricultural fields and agricultural machines. Methods and algorithms to solve this problem are developed. These algorithms are applicable to both robots and human-driven machines. The necessary condition is to cover the whole field, and the goal is to find as efficient a route as possible. As yet, there is no universal algorithm or method capable of solving the problem in all cases. Two new approaches to solve the coverage path planning problem in the case of agricultural fields and agricultural machines are presented for consideration. Both of them are greedy algorithms. In the first algorithm the view is from on top of the field, and the goal is to split a single field plot into subfields that are simple to drive or operate. This algorithm utilizes a trapezoidal decomposition algorithm, and a search is developed of the best driving direction and selection of subfields. This article also presents other practical aspects that are taken into account, such as underdrainage and laying headlands. The second algorithm is also an incremental algorithm, but the path is planned on the basis of the machine's current state and the search is on the next swath instead of the next subfield. There are advantages and disadvantages with both algorithms, neither of them solving the problem of coverage path planning problem optimally. Nevertheless, the developed algorithms are remarkable steps toward finding a way to solve the coverage path planning problem with nonomnidirectional vehicles and taking into consideration agricultural aspects. © 2009 Wiley Periodicals, Inc. [source] Recombinant DNA in meat additives: Specific detection of Roundup ReadyÔ soybean by nested PCRJOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE, Issue 10 2007Fábio CA Brod Abstract Soybean proteins are widely used by the meat industry as technological coadjutor when producing processed products such as emulsified and ground meat products. Since regulations for the use and labeling of GMOs and derived ingredients are in force in Brazil, a PCR-based method capable of detecting Roundup ReadyÔ (RR) soybean was employed for meat additives. Thirty-two samples of meat additives containing soy proteins were tested for the presence of soybean amplifiable DNA and RR soybean DNA. Twenty-five samples gave a positive signal for the lectin gene, confirming the presence of soybean amplifiable DNA and 15 samples returned a positive signal for specific RR detection confirming the presence of genetically modified soy. These results demonstrate for the first time the presence of RR soybean in meat additives. This method may be useful for meat industries interested in controlling the presence of RR soybean in additives used for meat products manufacture. Copyright © 2007 Society of Chemical Industry [source] New approach to 3D time-resolved angiographyMAGNETIC RESONANCE IN MEDICINE, Issue 5 2002Bruno Madore Abstract TRICKS is an acquisition and reconstruction method capable of generating 3D time-resolved angiograms. Arguably, the main problem with TRICKS is the way it handles the outer regions of the k -space matrix, leading to artifacts at the edges of blood vessels. An alternative to the data- processing stage of TRICKS, designed to better represent edges and small vessels, is presented here. A weakness of the new approach is an increased sensitivity to motion compared to TRICKS. Since this method can use the same data as TRICKS, a hybrid reconstruction method could conceivably be developed where the advantages of both approaches are combined. Magn Reson Med 47:1022,1025, 2002. © 2002 Wiley-Liss, Inc. [source] Computational relaxed TP model transformation: restricting the computation to subspaces of the dynamic model,ASIAN JOURNAL OF CONTROL, Issue 5 2009Szabolcs Nagy Abstract The tensor-product (TP) model transformation is a recently proposed numerical method capable of transforming linear parameter varying state-space models to the higher order singular value decomposition (HOSVD) based canonical form of polytopic models. It is also capable of generating various types of convex TP models, a type of polytop models, for linear matrix inequality based controller design. The crucial point of the TP model transformation is that its computational load exponentially explodes with the dimensionality of the parameter vector of the parameter-varying state-space model. In this paper we propose a modified TP model transformation that leads to considerable reduction of the computation. The key idea of the method is that instead of transforming the whole system matrix at once in the whole parameter space, we decompose the problem and perform the transformation element wise and restrict the computation to the subspace where the given element of the model varies. The modified TP model transformation can readily be executed in higher dimensional cases when the original TP model transformation fails. The effectiveness of the new method is illustrated with numerical examples. Copyright © 2009 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] Does stereoselective lymphatic absorption contribute to the enantioselective pharmacokinetics of halofantrine In Vivo?BIOPHARMACEUTICS AND DRUG DISPOSITION, Issue 4 2003David M. Shackleford Abstract Halofantrine (Hf) is a chiral, lipophilic phenanthrene methanol antimalarial which exhibits both enantioselective plasma pharmacokinetics and extensive lymphatic absorption when administered postprandially. In order to determine whether enantioselective lymphatic absorption contributes to the previously reported enantioselective pharmacokinetics of Hf, lymph samples collected from thoracic duct-cannulated dogs dosed with racemic Hf (100 mg, administered postprandially) were assayed with a chiral HPLC method capable of quantifying the relative amounts of (+)- and (,)-Hf. During the period when the majority (>95%) of Hf transport into lymph occurred (0,5 h post dose), essentially equal amounts of the two enantiomers were present in the intestinal lymph. At later times (e.g. 5,12 h post dose), there was a steady increase in the fraction of (+)-Hf present in lymph. The trends evident at later time points most likely reflect an increase in the proportion of (+)-Hf present in systemic blood, (resulting from enantioselective systemic metabolism) and a corresponding increase in (+)-Hf in the thoracic lymph by equilibration of drug across blood and lymphatic capillaries, as opposed to enantioselective lymphatic transport per se. This study was the first to examine the possibility of stereoselectivity in lymphatic transport, however, the data suggest that drug absorption (at least in the case of halofantrine) via the intestinal lymphatics is not enantioselective. Copyright © 2003 John Wiley & Sons, Ltd. [source] Metabonomics , a new approach in ophthalmologyACTA OPHTHALMOLOGICA, Issue 7 2009Anna Midelfart Abstract. Metabonomics is a new technology providing broad information about dynamic metabolic responses in living systems to pathophysiological stimuli or genetic modification. Nuclear magnetic resonance (NMR) spectroscopy is one of the most powerful methods in metabonomics; it is utilized to establish the metabolic profiles of biofluids, and is practically the only method capable of examining intact tissue samples. Experience with the application of metabonomics in eye research is still limited, yet this method provides the possibility of exploring metabolic processes in the eye in vivo. This article presents a brief background to the usefulness of metabonomics, and the possible applications of an NMR-based technique in eye research and clinical practice. [source] | |||||||||||||