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Analytical Tool (analytical + tool)
Kinds of Analytical Tool Selected AbstractsOn the convergence of the multi-point flux approximation O-method: Numerical experiments for discontinuous permeabilityNUMERICAL METHODS FOR PARTIAL DIFFERENTIAL EQUATIONS, Issue 6 2005G. T. Eigestad Abstract This article presents numerical convergence results for the multi-point flux approximation (MPFA) O-method applied to the pressure equation in 2D. The discretization is made directly in physical space, and the investigated cases are simulated on structured, but generally skew grids. Skew grids need to be used to correctly represent the physics of the underlying flow problems. Special emphasis is made on cases which impose singularities in the velocity field. Such cases frequently arise in the description of subsurface flow. Analytical tools may not be applicable to fully answer the question of convergence for such cases; in particular not for the physical space discretization. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2005 [source] Ordnungspolitik auf illegalen Märkten: Der Drogen- und WaffenmarktPERSPEKTIVEN DER WIRTSCHAFTSPOLITIK, Issue 1 2002Hanno Beck In this paper, the economic structure of illegal markets with special reference to the markets for illegal drugs and arms is analyzed. Analytical tools of System Dynamics are employed to emphasize the dynamic aspects of these markets. The results of our analysis enable us to evaluate state intervention in the illegal markets for drugs and arms. It seems possible to mitigate the drugs problem by supplying drugs to heavily addicted people on the basis of health care measures. However, a similar policy seems not to exist for the illegal arms trade. This shows that each illegal market requires a deeper understanding before it can be fought effectively. [source] Effects of intermediate load on damping of synchronous generatorEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 4 2006P. Aree Abstract The transfer-function block-diagram model of a single-machine infinite-bus power system, originally developed by Heffron and Phillips, has been a popular analytical tool amongst power system engineers for explanation and assessment of synchronous generator dynamic behaviors. Since this model simply accounts for the generator field circuit with none of the damper circuits, it may not always give a realistic transient response. Moreover, the model considers only a grid-system load without local and intermediate loads. Hence, effects of these loads together with the damper circuits on electromechanical damping have not yet been completely studied. In this paper, the Heffron-Phillips's model has been advanced to incorporate an intermediate load plus one additional damper circuit in the q -axis. The upgraded model demonstrates a great influence of the intermediate load together with the q -axis damper circuit on the electromechanical damping and the dynamic interaction between the field and damper flux linkages. The study shows the key contributions of load to rise and fall of the damping. It appears that the electromechanical damping can be improved with regard to the unity power-factor load through increasing in the natural damping and decreasing in the automatic voltage regulator (AVR) negative damping torques. Nevertheless, the damping is mostly declined, when the load power factor is poor. Moreover, it is markedly changed in relation to various locations of load. The damping characteristics of synchronous generator are investigated using the eigenvalue and frequency response methods. Copyright © 2006 John Wiley & Sons, Ltd. [source] Optical Measurements of Platinum Based Electrocatalysts for the Electrooxidation of Methanol,FUEL CELLS, Issue 1-2 2003K. Gruber Abstract In a combinatorial electrochemistry experiment quinine was used as a pH sensitive fluorescing indicator to detect the catalytic activity of methanol oxidation catalysts. During electrochemical experiments the surface of the electrode array was monitored with a CCD camera. The dependence of the intensity of the fluorescence on the applied potential was used as an analytical tool; to investigate the electrochemical performance of Pt based electrocatalysts, for the electrooxidation of methanol, in both short and long term tests. [source] Rich Phase Behavior in a Supramolecular Conducting Material Derived from an OrganogelatorADVANCED FUNCTIONAL MATERIALS, Issue 6 2009Josep Puigmartí-Luis Abstract Organic conducting fiber-like materials hold great promise for the development of nanowires that can act as connections in miniature electronic devices, as an alternative to inorganic nanometer scale structures. This article presents a conducting organic tetrathiafulvalene-based supramolecular material which possesses a rich phase behavior with different packing of the molecules in the different forms, evidenced by electron spin resonance (ESR) spectroscopy. The distinct phases of conducting nanofibers can be easily fabricated through the temperature control of their preparation process from a xerogel by doping with iodine vapors. A total of four conducting phases have been identified conclusively using ESR spectroscopy as the key analytical tool. Three of the phases show a good long-term stability and areas in which the I,V curves have ohmic behavior when studied by current sensing (conducting) AFM. They offer promise for applications where electrical nanometer scale connections are required. [source] Dependence of broad-scale geographical variation in fleshy-fruited plant species richness on disperser bird species richnessGLOBAL ECOLOGY, Issue 4 2004Ana L. Márquez ABSTRACT Aim, We analysed the interdependence of avian frugivore- and fruited plant-species richness at the scale of major river basins across Europe, taking into account several environmental factors along different spatial gradients. Location, Continental Europe and the British Isles. Methods, We focused on wintering birds and autumn/winter fruiting plants, and used major river basins as geographical units and Structural Equation Modelling as the principal analytical tool. Results, The statistical influence of disperser species richness on fleshy-fruited plant species richness is roughly double that of the reverse. Broad-scale variation in frugivore richness is more dependent on environmental factors than on fruited plant richness. However, the influence of disperser richness on plant richness is four times higher than the influence of environmental factors. Environmental influences on both birds and plants are greater than purely spatial influences. Main conclusions, Our results are interpreted as indicating that biotic dispersal of fruits strongly affects broad-scale geographical trends of fleshy-fruited plant species richness, whereas richness of fruited plants moderately affects frugivore richness. [source] Factors Associated with the Income Distribution of Full-Time Physicians: A Quantile Regression ApproachHEALTH SERVICES RESEARCH, Issue 5 2007Ya-Chen Tina Shih Objective. Physician income is generally high, but quite variable; hence, physicians have divergent perspectives regarding health policy initiatives and market reforms that could affect their incomes. We investigated factors underlying the distribution of income within the physician population. Data Sources. Full-time physicians (N=10,777) from the restricted version of the 1996,1997 Community Tracking Study Physician Survey (CTS-PS), 1996 Area Resource File, and 1996 health maintenance organization penetration data. Study Design. We conducted separate analyses for primary care physicians (PCPs) and specialists. We employed least square and quantile regression models to examine factors associated with physician incomes at the mean and at various points of the income distribution, respectively. We accounted for the complex survey design for the CTS-PS data using appropriate weighted procedures and explored endogeneity using an instrumental variables method. Principal Findings. We detected widespread and subtle effects of many variables on physician incomes at different points (10th, 25th, 75th, and 90th percentiles) in the distribution that were undetected when employing regression estimations focusing on only the means or medians. Our findings show that the effects of managed care penetration are demonstrable at the mean of specialist incomes, but are more pronounced at higher levels. Conversely, a gender gap in earnings occurs at all levels of income of both PCPs and specialists, but is more pronounced at lower income levels. Conclusions. The quantile regression technique offers an analytical tool to evaluate policy effects beyond the means. A longitudinal application of this approach may enable health policy makers to identify winners and losers among segments of the physician workforce and assess how market dynamics and health policy initiatives affect the overall physician income distribution over various time intervals. [source] The Colours of MoleculesIMAGING & MICROSCOPY (ELECTRONIC), Issue 1 2006Chemical Force Microscopy Enables a New Look on Surfaces Abstract As the surface functionality is gaining more and more relevance in modern surface technology, the need for an analytical tool with chemical sensitivity and high lateral resolution is becoming important more than ever. In this article, we introduce the novel method "Chemical Force Microscopy" (CFM), which is enabling the chemical mapping of the surface with nm-resolution for the first time. This method has proved to be efficient to optimise and understand different processes on industrial surfaces. In the fields like plasma, coating, cell biology, pharmaceutical and printing technologies, this method has shown to be supremely efficient. [source] Kinetic study of the gas-phase reaction of the nitrate radical with methyl-substituted thiophenesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 7 2003B. Cabañas The gas-phase reactions of the NO3 radical with 2-methylthiophene, 3-methylthiophene, and 2,5-dimethylthiophene have been studied, using relative and absolute methods at 298 K. Determination of relative rate was performed using Teflon collapsible bag as the reaction chamber and gas chromatography as the analytical tool. For the absolute method, experiments were carried out using fast-flow-discharge technique with detection of NO3 by laser-induced fluorescence. The temperature dependence was studied by the absolute technique for the reactions of NO3 with 2-methylthiophene and 3-methylthiophene in the range 263,335 K. The proposed Arrhenius expressions for the reaction of the nitrate radical with 2-methylthiophene and 3-methylthiophene are k = (4 ± 2) × 10,16 exp[,(2200 ± 100)/T]] cm3 molecule,1 s,1 and k = (3 ± 2) × 10,15 exp[,(1700 ± 200)/T]] cm3 molecule,1 s,1, respectively. © 2003 Wiley Periodicals, Inc. Int J Chem Kinet 35: 286,293, 2003 [source] Systematic formulations for electronegativity and hardness and their atomic scales within density functional softness theoryINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 2 2006Mihai V. Putz Abstract A unified Mulliken valence with Parr ground-state electronegativity picture is presented. It provides a useful analytical tool on which the absolute hardness as well ionization potential and electron affinity functionals are based. For all these chemical reactivity indices, systematic approximate density functionals are formulated within density functional softness theory and are applied to atomic systems. For the absolute hardness, a special relationship with the new electronegativity ansatz and a particular atomic trend paralleling the absolute electron affinity are established that should complement and augment the earlier finite-difference energetic approach. © 2005 Wiley Periodicals, Inc. Int J Quantum Chem, 2006 [source] Kinetic Enzymatic Resolution of Cyclopropane DerivativesADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 12 2003Jörg Pietruszka Abstract The kinetic enzymatic resolution of various cyclopropane derivatives was systematically investigated. The study focused on synthetically useful cyclopropylmethanols (e.g., 18a/j or 19a/j) as well as some rarely investigated cyclopropanols (e.g., 24/25 or 27). The combination of enantioselective catalytic or diastereoselective synthesis of enantiomerically enriched compounds with enzymatic approaches ultimately led to the most convenient route to enantiomerically pure starting materials. Again, this was especially proven for the synthesis of cyclopropanols 18a/j and 19a/j. Key to the successful investigation was to rigorously establish an analytical tool for the analysis of enantiomeric composition of reaction mixtures. [source] Hyperspectral imaging combined with principal component analysis for bruise damage detection on white mushrooms (Agaricus bisporus)JOURNAL OF CHEMOMETRICS, Issue 3-4 2008A. A. Gowen Abstract Hyperspectral imaging (HSI) combines conventional imaging and spectroscopy to simultaneously acquire both spatial and spectral information from an object. This technology has recently emerged as a powerful process analytical tool for rapid, non-contact and non-destructive food analysis. In this study, the potential application of HSI for damage detection on the caps of white mushrooms (Agaricus bisporus) was investigated. Mushrooms were damaged by controlled vibration to simulate damage caused by transportation. Hyperspectral images were obtained using a pushbroom line-scanning HSI instrument, operating in the wavelength range of 400,1000,nm with spectroscopic resolution of 5,nm. The effective resolution of the CCD detector was 580,×,580,pixels by 12 bits. Two data reduction methods were investigated: in the first, principal component analysis (PCA) was applied to the hypercube of each sample, and the second PC (PC 2) scores image was used for identification of bruise-damaged regions on the mushroom surface; in the second method PCA was applied to a dataset comprising of average spectra from regions normal and bruise-damaged tissue. In this case it was observed that normal and bruised tissue were separable along the resultant first principal component (PC 1) axis. Multiplying the PC 1 eigenvector by the hypercube data allowed reduction of the hypercube to a 2-D image, which showed maximal contrast between normal and bruise-damaged tissue. The second method performed better than the first when applied to a set of independent mushroom samples. The results from this study could be used for the development of a non-destructive monitoring system for rapid detection of damaged mushrooms on the processing line. Copyright © 2008 John Wiley & Sons, Ltd. [source] Hematopoietic progenitor cells (HPC) and immature reticulocytes evaluations in mobilization process: new parameters measured by conventional blood cell counterJOURNAL OF CLINICAL LABORATORY ANALYSIS, Issue 4 2006J.F.A. Noronha Abstract Monitoring the timing of leukapheresis in peripheral blood stem cells (PBSC) mobilization is an important clinical decision that requires an accurate analytical tool. The present study assessed hematopoietic progenitor cells (HPC) and immature reticulocyte fraction (IRF) counts provided by a routine automated blood counter as potential parameters for predicting the appropriate time for harvesting. The HPC and IRF values were compared with white blood cell (WBC) and CD34+ cell counts obtained by flow cytometry in 30 adult patients with hematological malignancies undergoing PBSC mobilization. It was observed that there was a significant correlation between HPC counts and CD34+ cells in peripheral blood counts (r=0.61, P=0.0003) and between the number of HPC and CD34+cells collected by leukapheresis (r=0.5733, P=0.0009). Comparing HPC, IRF, WBC, and CD34+ cells parameters as a sign of hematological recovery showed that the raise in immature reticulocytes counts preceded the increase of WBC (P=0.0002), HPC (P=0.0001), and CD34+ (P=0.0001) cells in peripheral blood counts. According to our results, HPC and IRF parameters may be integrated into clinical protocols to evaluate the timing of leukapheresis. IRF, as previously demonstrated in bone marrow transplantation, is the earliest sign of hematopoietic recovery in mobilization process. J. Clin. Lab. Anal. 20:149,153, 2006. © 2006 Wiley-Liss, Inc. [source] Rhetorical representations of masculinities in South Africa: moving towards a material-discursive understanding of menJOURNAL OF COMMUNITY & APPLIED SOCIAL PSYCHOLOGY, Issue 1 2003Russell Luyt Abstract A material-discursive perspective holds advantage in understanding male realities. It seeks to integrate dominant approaches that appear anaemic in their failure to capture the interplay between the material and discursive realms of human existence. Three dominant metaphorical themes in the rhetorical representation of South African masculinities are described in an attempt to illustrate the complexity of embodied masculine experience. In this sense the discussion seeks to reveal the dynamic nature of masculine debate and lived experience across differing contexts. It serves to underline the importance of adopting a material-discursive perspective in understanding men, which recognizes that they do not exist as a homogeneous social group, and as such experience their masculinities in a variable and changing fashion. The theoretical amalgamation of social representations and rhetoric is argued to provide a useful analytical tool in an endeavour of this nature. It is suggested that the rhetorical approach problematizes an overly consensual view of social reality that social representations theory typically promotes. Copyright © 2003 John Wiley & Sons, Ltd. [source] Isotropic Component Trace AnalysisJOURNAL OF NEUROIMAGING, Issue 3 2005Hitoshi Matsuzawa MD ABSTRACT A new method for analyzing diffusion tensor imaging (DTI) of the brain, based on a recently introduced algorithm, lambda chart analysis (LCA), is presented. Pretreatment of a given DTI data set with LCA, which effectively segregates isotropic and aniso tropic components, allows for total removal of the anisotropic component from the DTI data set. The remaining pure isotropic component can therefore be subjected to further analysis simi lar to that applied in the trace histogram method. Deconvolution of the trace function yielded 3 Gaussian elements. Remapping of these 3 deconvoluted isotropic elements back onto the 2-dimensional image plane provided anatomical correlates of each element. The algorithm, referred to here as isotropic com ponent trace analysis, can be used as a pictorial analytic tool, as well as a numerical analytical tool, for the noninvasive assess ment of isotropic parenchymal components. The presented method provides quantitative indices of certain parenchymal parameters with better clarity than currently available methods. A ready-to-use program, EZ-LCA, for this powerful method is provided (available at http://coe.bri.niigata-u.ac.jp). [source] Raman spectra of organic acids obtained using a portable instrument at ,5 °C in a mountain area at 2000 m above sea levelJOURNAL OF RAMAN SPECTROSCOPY, Issue 4 2010J. Jehli Abstract Well-resolved Raman spectra of organic acids were obtained with 785 nm excitation using a portable Raman instrument (Ahura First Defender XL) under low temperature ,5 °C atmospheric conditions at an altitude of 2000 m (Axamer Lizum, Innental, Austria). The portable Raman spectrometer tested in this setting permits fast and unambiguous detection of solid forms of these organic acids (formic, acetic, valeric, hexanoic, heptanoic, isophthalic, ascorbic and mellitic) under field conditions. This demonstrates the possibility to use a miniaturized Raman spectrometer as a key instrument for investigating the presence of organic compounds and biomolecules under low temperature conditions. These results are important for future missions focusing not only on Mars, where Raman spectroscopy will be a key non-destructive analytical tool for the in situ identification of organic compounds relevant to life detection on planetary surfaces or near sub-surfaces. Copyright © 2009 John Wiley & Sons, Ltd. [source] Asymmetrical flow field-flow fractionation coupled to multiangle laser light scattering detector: Optimization of crossflow rate, carrier characteristics, and injected mass in alginate separationJOURNAL OF SEPARATION SCIENCE, JSS, Issue 14 2007Enrica Alasonati Abstract The coupling of the flow field-flow fractionation (FlFFF) to differential refractive index (DRI) and multiangle laser light scattering (LS) detectors is a powerful tool for characterizing charged polysaccharides such as alginate. However, the correct interpretation of the experimental results and extrapolation of meaningful molecular parameters by using an analytical tool with such a level of complexity requires improvement of the knowledge of the alginate behavior in the channel and careful optimization of the operating conditions. Therefore, the influence of the critical operating parameters, such as crossflow rate, carrier composition and concentration, and sample load, on the alginate retention was carefully evaluated. Combined information obtained simultaneously by DRI and LS detectors over the wide range of the crossflow rate, carrier liquid concentration, and injected amount, allowed to set the appropriate combination of optimal parameters. It was found that the crossflow rate of 0.25 mL/min, carrier solution containing 5×10,2 mol/L ammonium or sodium chloride, and 50,100 ,g of injected sample mass were necessary to achieve complete separation and determination of the meaningful molecular characteristics. The values of the weight-average hydrodynamic radius (RHw), radius of gyration (RG), and molar mass (M), obtained under the optimal conditions were in good agreement to those found for alginates in the literature. [source] Patterns of species richness and turnover along the pH gradient in deciduous forests: testing the continuum hypothesisJOURNAL OF VEGETATION SCIENCE, Issue 6 2009Cord Peppler-Lisbach Abstract Question: (i) How do species richness and species turnover change along a pH gradient? (ii) What are possible driving factors behind these patterns? (iii) Can the observed patterns be explained by an individualistic continuum concept that postulates independence of species responses and constant turnover rates? Location: Semi-natural, deciduous hardwood forests in NW Germany (558 plots). Methods: The instantaneous rate of compositional turnover is measured by the sum of slope angles of modelled response curves (119 understorey species) at any point along the pH gradient. Total turnover rate, positive turnover rate (species increasing in probability of occurrence) and negative turnover rate (species decreasing in probability of occurrence) are calculated separately. Species richness is modelled using Poisson regression and by calculating the sum of predicted probabilities at any gradient point. Turnover rates are compared with those calculated from a null model based on a Gaussian community model. Soil chemical analyses of 49 plots are used to interpret biodiversity patterns. Results: Species richness shows a hump-shaped relation to pH(CaCl2) with a minor decline at approximately pH>5.0. The decline is possibly due to the confounding influence of water regime and local species pool effects. Increasing richness from pH 2.5 to 4.7 can be traced back to positive turnover exceeding negative turnover. Peaks in turnover rates, dominated by positive turnover, are located at pH 3.7 and 2.8, where turnover rates considerably exceed rates derived from the null model. The turnover pattern can be related to soil chemical conditions, e.g. decreasing base saturation, Al and H+ toxicity and the occurrence of mor. Conclusions: The high turnover rates and the massive imbalance in positive and negative turnover rates found in deciduous forests cannot be explained by the individualistic continuum concept. Physiological constraints at the gradient limits and species pool effects could be responsible for this. Their role should be considered more explicitly in vegetation concepts dealing with the continuum-discontinuum controversy. The presented approach can be regarded as a comprehensive analytical tool for a better understanding of biodiversity patterns along environmental gradients by linking species richness, turnover and response curve types. [source] Kinetic studies on the peroxyoxalate chemiluminescence reaction: determination of the cyclization rate constantLUMINESCENCE: THE JOURNAL OF BIOLOGICAL AND CHEMICAL LUMINESCENCE, Issue 5 2002Sandra M. Silva Abstract Although more currently utilized as analytical tool because of its high sensitivity and good reproducibility, the mechanism of the peroxyoxalate system, a chemiluminescence reaction with quantum yields only comparable to bioluminescence systems, has been extensively studied. The light emission mechanism can be divided in the pathway before chemiexcitation, which contains the rate-limiting steps, and the fast and kinetically non-observable chemiexcitation step. In this work, we obtain information on the mechanism of the slow pathways, attribute values to several rate constants prior to chemiexcitation and suggest a mechanistic scheme that could help optimization of conditions when the peroxyoxalate reaction is used as analytical tool. Copyright © 2002 John Wiley & Sons, Ltd. [source] Automated Raman Spectroscopy as a Tool for the High-Throughput Characterization of Molecular Structure and Mechanical Properties of PolyethylenesMACROMOLECULAR RAPID COMMUNICATIONS, Issue 1 2003Claus Gabriel Abstract Raman spectroscopy, which does not require a time-consuming sample preparation, is described as an analytical tool for the high-throughput characterization of polyethylenes. The content of comonomer and the amount of methyl groups per 1,000 carbon atoms of polyethylenes can be predicted from Raman spectra using multivariate data analysis. In addition, macroscopic properties, such as density and elastic modulus as well as yield stress, can be derived from Raman spectra. Raman spectra of selected metallocene-catalyzed polyethylenes of different comonomer content. [source] Probing interactions by means of pulsed field gradient nuclear magnetic resonance spectroscopy,MAGNETIC RESONANCE IN CHEMISTRY, Issue S1 2008Sara Cozzolino Abstract Molecular self-diffusion coefficients (D) of species in solution are related to size and shape and can be used for studying association phenomena. Pulsed field gradient nuclear magnetic resonance (PFG-NMR) spectroscopy has been revealed to be a powerful analytical tool for D measurement in different research fields. The present work briefly illustrates the use of PFG-NMR for assessing the existence of interactions in very different chemical systems: organic and organometallic compounds, colloidal materials and biological aggregates. The application of PFG-NMR is remarkable for understanding the role of anions in homogenous transition metal catalysis and for assessing the aggregation behaviour of biopolymers in material science. Copyright © 2008 John Wiley & Sons, Ltd. [source] Chip-mass spectrometry for glycomic studiesMASS SPECTROMETRY REVIEWS, Issue 2 2009Laura Bindila Abstract The introduction of micro- and nanochip front end technologies for electrospray mass spectrometry addressed a major challenge in carbohydrate analysis: high sensitivity structural determination and heterogeneity assessment in high dynamic range mixtures of biological origin. Chip-enhanced electrospray ionization was demonstrated to provide reproducible performance irrespective of the type of carbohydrate, while the amenability of chip systems for coupling with different mass spectrometers greatly advance the chip/MS technique as a versatile key tool in glycomic studies. A more accurate representation of the glycan repertoire to include novel biologically-relevant information was achieved in different biological sources, asserting this technique as a valuable tool in glycan biomarker discovery and monitoring. Additionally, the integration of various analytical functions onto chip devices and direct hyphenation to MS proved its potential for glycan analysis during the recent years, whereby a new analytical tool is on the verge of maturation: lab-on-chip MS glycomics. The achievements until early beginning of 2007 on the implementation of chip- and functional integrated chip/MS in systems glycobiology studies are reviewed here. © 2009 Wiley Periodicals, Inc., Mass Spec Rev 28:223,253, 2009 [source] Protein sequence information by matrix-assisted laser desorption/ionization in-source decay mass spectrometryMASS SPECTROMETRY REVIEWS, Issue 5 2007Julie Hardouin Abstract Proteins from biological samples are often identified by mass spectrometry (MS) with the two following "bottom-up" approaches: peptide mass fingerprinting or peptide sequence tag. Nevertheless, these strategies are time-consuming (digestion, liquid chromatography step, desalting step), the N - (or C -) terminal information often lacks and post-translational modifications (PTMs) are hardly observed. The in-source decay (ISD) occurring in a matrix assisted laser desorption/ionization (MALDI) source appears an interesting analytical tool to obtain N -terminal sequence, to identify proteins and to characterize PTMs by a "top-down" strategy. The goal of this review deals with the usefulness of the ISD technique in MALDI source in proteomics fields. In the first part, the ISD principle is explained and in the second part, the use of ISD in proteomic studies is discussed for protein identification and sequence characterization. © 2007 Wiley Periodicals, Inc., Mass Spec Rev 26:672,682, 2007 [source] Biomedical applications of 7Li NMRNMR IN BIOMEDICINE, Issue 2 2005Richard A. Komoroski Abstract The biomedical applications of 7Li MRS and MRI have been progressing slowly. The interest derives primarily from the clinical use of Li to treat bipolar disorder. One area of concern is the nature of ionic transport and binding, so as to elucidate the mechanism(s) of therapeutic action and toxicity. Another is the development of a non-invasive, in vivo analytical tool to measure brain Li concentration and environment in humans, both as an adjunct to treatment and as a mechanistic probe. Here we review the most recent progress toward these goals. Copyright © 2005 John Wiley & Sons, Ltd. [source] Structures of the unspoken: the theatre of Nathalie SarrauteORBIS LITERARUM, Issue 3 2003John Rothenberg Nathalie Sarraute's short intense plays dramatize the inner movements and emotions which she calls tropisms. There is no plot, no surface action in these works, and in this they typify an important trend in twentieth century theatre. The effect of these plays where nothing happens is far from static, however, and this article examines Le Silence and C'est beau to discover how this effect is achieved, how the author creates a variety of tension and a feeling of dramatic momentum. Using the actantial model first proposed by Souriau as an analytical tool it can be shown that within the basic situtation, which does not change, we have a series of microdramas, shifting alliances and conflicts. These are plays about what lies beneath the everyday, and they are structured to maintain a tension, sometimes comic sometimes cruel, between the surface and the depths. [source] Analytical investigation of styrax and benzoin balsams by HPLC- PAD-fluorimetry and GC-MSPHYTOCHEMICAL ANALYSIS, Issue 4 2008Michael Hovaneissian Abstract An HPLC and GC study has been conducted on the aromatic oleoresins styrax and benzoin produced by several American, Mediterranean and East-Asian trees, and widely used in ancient civilisations for their therapeutic and odoriferous properties. Initial experiments were performed by HPLC-PAD-fluorimetry for the analysis of several aromatic components, and then completed by GC-MS for the characterisation of both aromatic and triterpenic derivatives. In this work, it was crucial to isolate from fresh natural exudates, and to characterise by two-dimensional NMR, some of the major constituents in order to extend the standard molecular pool prior to chromatographic identifications. This study reveals coniferyl benzoate as an excellent distinctive fluorescent biomarker of Siam benzoin substrate. It also confirms that fluorimetric-coupled detection is a powerful analytical tool for the identification of compounds in Hamamelidaceae extracts that are almost undetectable by UV. GC-MS was successfully applied to the determination of the botanical origin of Sumatra benzoin, and to the identification of lupeol [3, -lup-20(29)-en-3-ol] for the first time in such balsam-type materials. Copyright © 2007 John Wiley & Sons, Ltd. [source] Variation in oxygen isotope fractionation during cellulose synthesis: intramolecular and biosynthetic effectsPLANT CELL & ENVIRONMENT, Issue 10 2006LEONEL STERNBERG ABSTRACT The oxygen isotopic composition of plant cellulose is commonly used for the interpretations of climate, ecophysiology and dendrochronology in both modern and palaeoenvironments. Further applications of this analytical tool depends on our in-depth knowledge of the isotopic fractionations associated with the biochemical pathways leading to cellulose. Here, we test two important assumptions regarding isotopic effects resulting from the location of oxygen in the carbohydrate moiety and the biosynthetic pathway towards cellulose synthesis. We show that the oxygen isotopic fractionation of the oxygen attached to carbon 2 of the glucose moieties differs from the average fractionation of the oxygens attached to carbons 3,6 from cellulose by at least 9%, for cellulose synthesized within seedlings of two different species (Triticum aestivum L. and Ricinus communis L.). The fractionation for a given oxygen in cellulose synthesized by the Triticum seedlings, which have starch as their primary carbon source, is different than the corresponding fractionation in Ricinus seedlings, within which lipids are the primary carbon source. This observation shows that the biosynthetic pathway towards cellulose affects oxygen isotope partitioning, a fact heretofore undemonstrated. Our findings may explain the species-dependent variability in the overall oxygen isotope fractionation during cellulose synthesis, and may provide much-needed insight for palaeoclimate reconstruction using fossil cellulose. [source] Communication with the Environment?POLITICS, Issue 3 2000Non-human Nature in the Theories of Jürgen Habermas The theories of Jürgen Habermas provide us with a powerful analytical tool for the analysis of politics, including social movements. However, they are lacking in one particular area, the analysis of environmental politics. The reasons behind these difficulties can be traced through the development of Habermas's work and lie in the inability of non-human nature to participate in language-based discourse. The dilemma is acute , the ecocentric moral position needs grounding in the rationality of discourse if it is not to slip into possibly dangerous irrationality, but how can such a grounding occur? This article reviews the development of discussion in this area and investigates advocacy as a possible resolution of the problem. [source] Fluorescent gel particles in the nanometer range for detection of metabolites in living cells,POLYMERS FOR ADVANCED TECHNOLOGIES, Issue 9-10 2006Kristoffer Almdal Abstract In this present work a research program that aims at the development of sensor particles based on ratiometric detection of fluorescence from two dyes was embarked on. Such particles can in principle be used to achieve spatially and time resolved measurements of metabolite concentrations in living cells. The dyes are chosen such that the fluorescence of one dye is a function of an analyte concentration whereas the fluorescence of the other dye is independent of variations in the medium. Methods have been investigated for synthesizing such particles based on crosslinked polyacrylamide in inverse micelles in oil microemulsions. Typical sizes of the particles are tens of nanometers. Characterization methods for such particles based on size exclusion chromatography, photon correlation spectroscopy, scanning electron microscopy, and atomic force microscopy have been developed. The stability of the sensor particles and their potential as an analytical tool will be discussed. Copyright © 2006 John Wiley & Sons, Ltd. [source] Diversity in fertility patterns in GuatemalaPOPULATION, SPACE AND PLACE (PREVIOUSLY:-INT JOURNAL OF POPULATION GEOGRAPHY), Issue 6 2006Sofie De Broe Abstract This study investigates urban and rural fertility trends in Guatemala up to 2002. It also aims to establish, using the theory of diffusion as its theoretical framework, the extent to which ethnicity and ethnic diversity are associated with geographical patterns in local-level fertility after controlling for socio-economic indicators. Data from the Demographic and Health Surveys of 1987, 1995,96 and 1998,99, the National Maternal and Child Health Survey of 2002 and the Census of 2002 were used. P/F ratios were calculated and used as an analytical tool and quality control measure of the data in order to establish the timing of changes in fertility patterns as measured by age-specific fertility rates (ASFRs) based on exact exposure in four-year periods from 1972 to 2002. Finally, the 2002 census data were used to analyse and model fertility at the municipio- level using ordinary least squares regression. The results suggest a steady but very slow decline in fertility from 1972 until the mid-1990s. Both the P/F ratios and ASFRs calculated using the Maternal and Child Health Survey and Census of 2002 show a sharp decline in fertility since 1998. The regression results for the census data suggest an independent and significant effect of ,proportion of indigenous people' and an almost significant effect of ethnic diversity on fertility at the municipio -level. The very slow decline in fertility in Guatemala until fairly recently can be attributed to the fact that Guatemala has been lagging behind in terms of socio-economic development and the additional challenge of having a culturally very diverse and segregated population, preventing the spread of modern reproductive ideas and behaviour. The accelerated fertility decline since the end of the 1990s seems likely to be associated with the widespread availability and increased uptake of family planning following declining fertility desires among its indigenous population. Copyright © 2006 John Wiley & Sons, Ltd. [source] | ||||||||||||||||||||||||||||||||||