Identification Methodology (identification + methodology)

Distribution by Scientific Domains


Selected Abstracts


,Mass defect' tags for biomolecular mass spectrometry

JOURNAL OF MASS SPECTROMETRY (INCORP BIOLOGICAL MASS SPECTROMETRY), Issue 8 2003
Michael P. Hall
Abstract We present a new class of ,mass defect' tags with utility in biomolecular mass spectrometry. These tags, incorporating element(s) with atomic numbers between 17 (Cl) and 77 (Ir), have a substantially different nuclear binding energy (mass defect) from the elements common to biomolecules. This mass defect yields a readily resolvable mass difference between tagged and untagged species in high-resolution mass spectrometers. We present the use of a subset of these tags in a new protein sequencing application. This sequencing technique has advantages over existing mass spectral protein identification methodologies: intact proteins are quickly sequenced and unambiguously identified using only an inexpensive, robust mass spectrometer. We discuss the potential broader utility of these tags for the sequencing of other biomolecules, differential display applications and combinatorial methods. Copyright © 2003 John Wiley & Sons, Ltd. [source]


Model updating using noisy response measurements without knowledge of the input spectrum

EARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 2 2005
Ka-Veng Yuen
Abstract A new probabilistic model identification methodology is proposed using measured response time histories only. The proposed approach requires that the number of independent measurements is larger than the number of independent excitations. Under this condition, no input measurements or any information regarding the stochastic model of the input is required. Specifically, the method does not require the response to be stationary and does not assume any knowledge of the parametric form of the spectral density of the input. Therefore, the method has very wide applicability. The proposed approach allows one to obtain not only the most probable values of the updated model parameters but also their associated uncertainties using only one set of response data. It is found that the updated probability distribution can be well approximated by a Gaussian distribution centered at the most probable values of the parameters. Examples are presented to illustrate the proposed method. Copyright © 2004 John Wiley & Sons, Ltd. [source]


Reproductive ecology of the reef manta ray Manta alfredi in southern Mozambique

JOURNAL OF FISH BIOLOGY, Issue 1 2010
A. D. Marshall
The application of a photographic identification methodology using the unique ventral surface markings (natural spot patterns) of an observed population in southern Mozambique enabled many aspects of the reproductive ecology of reef manta rays Manta alfredi to be examined. The region encompassing the study site was identified as a mating ground for M. alfredi based on observations of mating events and fresh mating scars on females. The distribution of these pectoral fin scars was highly biased and indicated a strong lateralized behavioural trait, with 99% of these scars occurring only on the left pectoral fin. No other elasmobranch has been reported to display behavioural lateralization. The study region also acts as a birthing ground, with individuals typically giving birth in the austral summer period after a gestation of c. 1 year. Reproductive periodicity in M. alfredi was most commonly biennial, but a few individuals were pregnant in consecutive years, confirming an annual ovulatory cycle. The production of a single pup appears to be the normal situation, although observations in the wild as well as during opportunistic dissections of individuals killed by fisheries revealed that two pups are conceived on occasion. Many aspects of the study have contributed to the limited baseline data currently available for this species and have highlighted the potential need for more conservative conservation strategies. [source]


Leaning into the Wind: A Structural VAR Investigation of UK Monetary Policy,

OXFORD BULLETIN OF ECONOMICS & STATISTICS, Issue 5 2005
Andrew Mountford
Abstract This paper adapts Uhlig's [Journal of Monetary Economics (2005) forthcoming] sign restriction identification methodology to investigate the effects of UK monetary policy using a structural vector autoregression (VAR). It shows that shocks which can reasonably be described as monetary policy shocks have played only a small role in the total variation of UK monetary and macroeconomic variables. Most of the variation in UK monetary variables has been due to their systematic reaction to other macroeconomic shocks, namely non-monetary aggregate demand, aggregate supply, and oil price shocks. We also find, without imposing any long run identifying restrictions, that aggregate supply shocks have permanent effects on output. [source]


The emerging field of chemical genetics: potential applications for pesticide discovery

PEST MANAGEMENT SCIENCE (FORMERLY: PESTICIDE SCIENCE), Issue 12 2007
Terence A Walsh
Abstract The use of small molecules to probe biological systems, generally described as ,chemical genetics', has grown considerably in the past 7 years, especially in areas related to human biology and therapeutics. This review describes some aspects of chemical genetics technologies that can be usefully applied to pesticide target discovery and lead generation. The chemical genetics approach (consisting of a phenotype screen, a chemical library and a robust target identification methodology) is compared with conventional and target-based screening. The outcomes of a chemical genetics approach are novel protein targets coupled with in vivo -active chemical ligands. The ,chemistry-first' paradigm of the chemical genetics approach can circumvent some of the obstacles that have emerged for the exploitation of novel but chemically unvalidated targets identified from genetic or genomic screens. Some of the advantages and challenges in using chemical genetics approaches are reviewed. Copyright © 2007 Society of Chemical Industry [source]


An analytical model for steady coextrusion of viscoplastic fluids in thin slit dies with wall slip

POLYMER ENGINEERING & SCIENCE, Issue 4 2010
Dilhan M. Kalyon
Coextrusion is widely used to fabricate multilayered products with each layer providing a separate functionality, including barrier resistance to gases, strength, and printability. Here an analytical model of the coextrusion die flow of two incompressible, viscoplastic fluids in a slit die, subject to nonlinear wall slip and under fully developed and isothermal conditions, is developed to allow the prediction of the steady-state velocity and shear stress distributions and the flow rate versus pressure gradient relationship. The resulting model is applied to the coextrusion of two layers of viscoplastic fluids in a thin rectangular slit die (slit gap, h , slit width, W). The analytical solution recognizes a number of distinct flow conditions (eleven cases) that need to be treated separately. The solutions for all eleven cases are provided along with an apriori identification methodology for the determination of the applicable case, given the shear viscosity and wall slip parameters of the two viscoplastic fluids, the slit geometry and the flow conditions. Simplifications of the model would provide the solutions for the fully developed and isothermal coextrusion flows of any combination of Hershel-Bulkley, Bingham, power-law and Newtonian fluids with or without wall slip at one or both walls of the slit die. POLYM. ENG. SCI., 2010. © 2009 Society of Plastics Engineers [source]


The molecular scanner in microscope mode

RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 22 2006
Stefan L. Luxembourg
The combination of microscope mode matrix-assisted laser desorption/ionization (MALDI) imaging mass spectrometry (IMS) with protein identification methodology: the molecular scanner, was explored. The molecular scanner approach provides improvement of sensitivity of detection and identification of high-mass proteins in microscope mode IMS. The methodology was tested on protein distributions obtained after separation by sodium dodecyl sulfate/polyacrylamide gel electrophoresis (SDS-PAGE). High-quality, high-spatial-resolution ion images were recorded on a TRIFT-II ion microscope after gold coating of the MALDI sample preparation on the poly(vinylidenedifluoride) capture membranes. The sensitivity of the combined method is estimated to be 5 pmol. The minimum amount of sample consumed, needed for identification, was estimated to be better than 100 fmol. Software tools were developed to analyze the spectral data and to generate broad mass range and single molecular component microscope mode ion images and single mass-to-charge ratio microprobe mode images. Copyright © 2006 John Wiley & Sons, Ltd. [source]