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Simple Analysis (simple + analysis)
Selected AbstractsInvestigating the role of heparin sulfate proteoglycans in hereditary multiple exostoses (HME) tumourigenesisINTERNATIONAL JOURNAL OF EXPERIMENTAL PATHOLOGY, Issue 4 2004Z.M. Scholefield Introduction Heparin sulfate (HS) has long been implicated in the bone deformity hereditary multiple exostoses (HME), and it is now clear that HME is associated with mutations in the HS biosynthetic genes EXT1 and EXT2. Interestingly, HME is also associated with an increased risk of chondro- and osteo-sarcomas. Methods and results Preliminary analysis of GAG samples purified from fibroblasts of both HME and isolated non-HME exostoses patients reveal a dramatic shift in the ratio of CS : HS, with the HME and isolated cases having a much higher proportion of CS relative to normal controls. This is true in the case of both shed and cell surface material but is far more extreme in the latter, with the HS reducing from approximately 45% in the controls to less than 10% in HME patients. Initial analysis also reveals shortened chain length within these samples; indeed they often have two populations of chains present. Simple analysis of the total disaccharide composition of these samples demonstrates no significant differences against controls. However, detailed analysis of the subpopulations of chains (as determined by chain length) within these samples as well as cartilaginous samples from exostoses patients may provide further insight into the changes that occur within the biosynthetic pathway following disrupted EXT function. We are also carrying out immunocytochemistry with a variety of HS-specific antibodies with the aim to further investigate normal HS structure and localization. This is being carried out on human primary chondrocytes isolated from normal patients and also adult mesenchymal stem cells as they undergo differentiation into chondrocytes. HS has been identified in both these cell types, and it is hoped that the manipulation of these cells through RNAi of different enzymes of the HS biosynthetic pathway will provide a suitable model for studying what changes may occur in cellular HS structures over the initial differentiation process in the growth plate. Discussion Together, these investigations should provide a good model to allow us to determine the role of HS in chondrocyte differentiation and maturation in both normal and diseased states. [source] Bayesian analysis of plant disease predictionPLANT PATHOLOGY, Issue 4 2002J. E. Yuen Rule-based systems for the prediction of the occurrence of disease can be evaluated in a number of different ways. One way is to examine the probability of disease occurrence before and after using the predictor. Bayes's Theorem can be a useful tool to examine how a disease forecast (either positive or negative) affects the probability of occurrence, and simple analyses can be conducted without knowing the risk preferences of the targeted decision makers. Likelihood ratios can be calculated from the sensitivity and specificity of the forecast, and provide convenient summaries of the forecast performance. They can also be used in a simpler form of Bayes's Theorem. For diseases where little or no prior information on occurrence is available, most forecasts will be useful in that they will increase or decrease the probability of disease occurrence. For extremely common or extremely rare diseases, likelihood ratios may not be sufficiently large or small to substantially affect the probability of disease occurrence or make any difference to the actions taken by the decision maker. [source] Concurrent Management of an Exotic Species and Initial Restoration Efforts in ForestsRESTORATION ECOLOGY, Issue 4 2005Stephen D. Murphy Abstract One of the proximate results of forest fragmentation, and a cause of continued microenvironmental change and exacerbation of ecological problems, is increased invasions by weedy plant species. One such example is Alliaria petiolata (Brassicaceae), a serious pest threatening much of eastern North America. Alliaria petiolata impedes mitigation of fragmentation and restoration efforts because it tends to outcompete and possibly extirpate much of the native understory species on localized scales. As part of a strategy to address the problems of fragmented habitats, an experiment was conducted to determine whether Sanguinaria canadensis (Papaveraceae) could outcompete A. petiolata. Using an additive design, I transplanted S. canadensis at densities of 0, 1, 2, 3, 5, 7, 9, 11, 15, and 20 ramets/m2 in 1997 and allowed them to interact with initial A. petiolata densities of 128 seedlings and 31 rosettes/m2. As of 2000, multivariate analyses of variance with repeated measures and simple analyses of variance indicated that initial S. canadensis densities of as little as 5 ramets/m2 suppressed A. petiolata. Initial S. canadensis densities of 9 and 11 ramets/m2 resulted in the lowest numbers of late-spring seedlings, numbers and sizes of year 1 and 2 rosettes, numbers and gross areas of stem leaves, numbers of flowering individuals, number of flowers, number of fruits (siliques), and height at flowering. While it remains to be tested whether this will continue and if the reestablishment of S. canadensis will help reassemble forest ecosystems, the experiments indicated that transplanting S. canadensis was effective at mitigating the spread of A. petiolata. [source] Multi-scale responses of plant species diversity in semi-natural buffer strips to agricultural landscapesAPPLIED VEGETATION SCIENCE, Issue 2 2008Maohua Ma Question: How does agricultural land usage affect plant species diversity in semi-natural buffer strips at multiple scales? Location: Lepsämä River watershed, Nurmijärvi, Southern Finland. Methods: Species diversity indicators included both richness and evenness. Plant communities in buffer strips were surveyed in 29 sampling sites. Using ArcGIS Desktop 9.0 (ArcInfo) and Fragstats 3.3 for GIS analysis, the landscape composition around each sampling site was characterized by seven parameters in square sectors at five scales: 4, 36, 100, 196, and 324ha. For each scale, Principle Component Analysis was used to examine the importance of each structural metric to diversity indicators using multiple regression and other simple analyses. Results: For all but the smallest scales (4 ha), two structural metrics including the diversity of land cover types and percentage of arable land were positively and negatively correlated with species richness, respectively. Both metrics had the highest correlation coefficients for species richness at the second largest scale (196 ha). The density of arable field edges between the fields was the only metric that correlated with species evenness for all scales, which had highest predictive power at the second smallest scale (36 ha). Conclusions: Species richness and evenness of buffer strips had scale-dependent relationships to land use in agricultural ecosystems. The results of this study indicated that species richness depends on the pattern of arable land use at large scales, which may relate to the regional species pool. Meanwhile, species evenness depended on the level of field edge density at small scales, which relates to how the nearby farmland was divided by the edges (e.g. many small-scale fields with high edge density or a few big-scale fields with low edge density). This implies that it is important to manage the biodiversity of buffer strips within a landscape context at multiple scales. [source] Is the housing market set to fall?ECONOMIC OUTLOOK, Issue 4 2001Article first published online: 16 DEC 200 Some analysts have suggested that house prices are set to collapse, particularly in the London area. These conclusions are generally based on a rather simple analysis of house price to income ratios. We argue that this is misleading and there is little evidence to suggest a collapse in the market. [source] Operational and structural optimization of multi-carrier energy systemsEUROPEAN TRANSACTIONS ON ELECTRICAL POWER, Issue 5 2006Martin Geidl Abstract This paper presents an approach for the combined optimization of energy systems including multiple energy carriers such as electricity, natural gas, and district heat. Power flow and conversion between the different energy infrastructures are described as multi-input multi-output coupling, what enables simple analysis and optimization of the flows. While previous work deals with operational optimization (multi-carrier optimal dispatch and power flow), this paper focuses on optimization of the couplings between the different networks, that is the structure of the system. Copyright © 2006 John Wiley & Sons, Ltd. [source] Predicting the Tails of Breakthrough Curves in Regional-Scale Alluvial SystemsGROUND WATER, Issue 4 2007Yong Zhang The late tail of the breakthrough curve (BTC) of a conservative tracer in a regional-scale alluvial system is explored using Monte Carlo simulations. The ensemble numerical BTC, for an instantaneous point source injected into the mobile domain, has a heavy late tail transforming from power law to exponential due to a maximum thickness of clayey material. Haggerty et al.'s (2000) multiple-rate mass transfer (MRMT) method is used to predict the numerical late-time BTCs for solutes in the mobile phase. We use a simple analysis of the thicknesses of fine-grained units noted in boring logs to construct the memory function that describes the slow decline of concentrations at very late time. The good fit between the predictions and the numerical results indicates that the late-time BTC can be approximated by a summation of a small number of exponential functions, and its shape depends primarily on the thicknesses and the associated volume fractions of immobile water in "blocks" of fine-grained material. The prediction of the late-time BTC using the MRMT method relies on an estimate of the average advective residence time, tad. The predictions are not sensitive to estimation errors in tad, which can be approximated by , where is the arithmetic mean ground water velocity and L is the transport distance. This is the first example of deriving an analytical MRMT model from measured hydrofacies properties to predict the late-time BTC. The parsimonious model directly and quantitatively relates the observable subsurface heterogeneity to nonlocal transport parameters. [source] Multilevel Models in Family Research: Some Conceptual and Methodological IssuesJOURNAL OF MARRIAGE AND FAMILY, Issue 2 2002Jay Teachman Examining the impact of context on individual-level outcomes has become an increasingly common undertaking in the social sciences. The growth in concern for identifying the effects of macrolevel characteristics has generated both theoretical and methodological advancements. In this issue of Journal of Marriage and Family, Butler (2002) researches whether the effect of welfare benefit levels on premarital childbearing varies by context, Hoffmann (2002) researches the effect of context on adolescent drug use, and Simons et al. (2002) examine how the relationship between parenting and child conduct varies by context. These articles are used as a background to discuss important theoretical and methodological issues surrounding the analysis of multilevel data. The authors present a simple analysis of data pertaining to age at first marriage taken from the Panel Study of Income Dynamics and merged with census data to measure contextual effects as a pedagogical device for introducing readers to the benefits of multilevel modeling. [source] Aggregative Public Good GamesJOURNAL OF PUBLIC ECONOMIC THEORY, Issue 2 2007RICHARD CORNES We exploit the aggregative structure of the public good model to provide a simple analysis of the voluntary contribution game. In contrast to the best response function approach, ours avoids the proliferation of dimensions as the number of players is increased, and can readily analyze games involving many heterogeneous players. We demonstrate the approach at work on the standard pure public good model and show how it can analyze extensions of the basic model. [source] Headspace single-drop microextraction of herbal essential oilsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 2 2008Martin Adam Abstract A method employing the headspace single-drop microextraction (HS-SDME) is presented for the determination of essential oils in dried herbal leaves. By optimising the key experimental parameters, a linear response for the individual target compounds was obtained in the concentration range from LOQ to 4 mg/mL (r2 = 0.9912,0.9998), with LODs from 3.3 up to 20.5 ,g per 100 g of dried leaves, and the repeatability within the RSD of 2.1,8.9%. The HS-SDME-based procedure, enabling a rapid and simple analysis of essential oils in herbs, was applied to selected real samples (nine essential oils in four different samples) in combination with GC-FID identification and quantification of the target volatiles. [source] Relationship between the structural distortion and the Mn electronic state in La1,xCaxMnO3: a Mn K -edge XANES studyJOURNAL OF SYNCHROTRON RADIATION, Issue 4 2009Jesús Chaboy A theoretical study of the X-ray absorption near-edge structure (XANES) spectra at the Mn K -edge in the La1,xCaxMnO3 series is reported. The relationship between the edge shift, the Ca,La substitution and the distortion of the MnO6 octahedra in these systems has been studied. It is shown that, by correctly considering these effects simultaneously, the experimental XANES data are consistent with the presence of two different Mn local environments in the intermediate La1,xCaxMnO3 compounds. By taking into account the energy shift associated with the modification of the MnO6 distortion as Ca substitutes for La, it is possible to reproduce the XANES spectra of the intermediate-doped compounds starting from the experimental spectra of the end-members LaMnO3 and CaMnO3. These results point out the need to re-examine the conclusions derived in the past from the simple analysis of the Mn K -edge XANES edge-shift in these materials. In particular, it is shown that the modification of the Mn K -edge absorption through the La1,xCaxMnO3 series is well reproduced by considering the simultaneous presence of both distorted and undistorted octahedra and, consequently, that the existence of charge-ordering phenomena cannot be ruled out from the XANES data. [source] Review article: anti TNF-, induced psoriasis in patients with inflammatory bowel diseaseALIMENTARY PHARMACOLOGY & THERAPEUTICS, Issue 9 2009G. FIORINO Summary Background, Anti TNF-, agents are used successfully for several autoimmune diseases, including IBD and psoriasis. An emerging challenge is the increasing incidence of anti TNF-, induced psoriasis. A total of 120 cases have been currently reported, of whom 18 patients were treated with biological agents for IBD. Objectives, To analyse all cases of anti TNF-, induced psoriasis in patients with IBD in the literature and to investigate potential mechanisms of action. Methods, A literature review was performed in the PubMed, Medline, Cochrane and EMBASE databases, with simple analysis of demographic data, drug administration and psoriasis onset. Risk and incidence patient/year/duration (pyd) was calculated. Results, A total of 18 patients with IBD treated by anti TNF-, agents developed drug-induced psoriasis of which, 17 patients developed with infliximab, one with adalimumab. The most frequent time of onset is between 3rd and 4th infusion of infliximab. Withdrawal of infliximab led to regression of lesions in 16 patients. In six patients, infliximab was reintroduced with no further recurrence of psoriasis. Conclusions, Although anti TNF-, induced psoriasis is extremely rare, understanding the mechanism will be a key step towards better realizing the role played by TNF-, and its pharmacological inhibitors in immune-mediated diseases. [source] On the transient phase of balanced SSFP sequencesMAGNETIC RESONANCE IN MEDICINE, Issue 4 2003Klaus Scheffler Abstract The signal intensity of balanced steady-state free precession (SSFP) imaging is a function of the proton density, T1, T2, flip angle (,), and repetition time (TR). The steady-state signal intensity that is established after about 5*T1/TR can be described analytically. The transient phase or the approach of the echo amplitudes to the steady state is an exponential decay from the initial amplitude after the first excitation pulse to the steady-state signal. An analytical expression of the decay rate of this transient phase is presented that is based on a simple analysis derived from the Bloch equations. The decay rate is a weighted average of the T1 and T2 relaxation times, where the weighting is determined by the flip angle of the excitation pulses. Thus, balanced SSFP imaging during the transient phase can provide various contrasts depending on the flip angle and the number of excitation pulses applied before the acquisition of the central k -space line. In addition, transient imaging of hyperpolarized nuclei, such as 3He, 129Xe, or 13C, can be optimized according to their T1 and T2 relaxation times. Magn Reson Med 49:781,783, 2003. © 2003 Wiley-Liss, Inc. [source] Analysis and determination of coupling efficiency and misalignment tolerances between a laser diode and a conically lensed fiberMICROWAVE AND OPTICAL TECHNOLOGY LETTERS, Issue 3 2004A. R. Faidz Abstract In this paper, we present a simple analysis, utilising the ABCD transformation matrix method, to analyze and determine the coupling efficiency and misalignment tolerances between a laser diode and a conically lensed fibre. The calculated and measured results, that is, the coupling efficiencies and transverse misalignments, were compared for microlenses etched at 20, 30, and 40 min. The calculated results agree well with the measured values. The angular misalignments are also calculated to determine their tolerances. © 2004 Wiley Periodicals, Inc. Microwave Opt Technol Lett 40: 191,195, 2004; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.11325 [source] A search for the third lensed image in JVAS B1030+074MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, Issue 4 2007M. Zhang ABSTRACT Central gravitational image detection is very important for the study of the mass distribution of the inner parts (,100 pc) of lens galaxies. However, the detection of such images is extremely rare and difficult. We present a 1.7-GHz High Sensitivity Array (HSA) observation of the double-image radio lens system B1030+074. The data are combined with archive Very Long Baseline Array and global very long baseline interferometry (VLBI) observations, and careful consideration is given to the effects of noise, cleaning and self-calibration. An upper limit is derived for the strength of the central image of 180 ,Jy (90 per cent confidence level), considerably greater than would have been expected on the basis of a simple analysis. This gives a lower limit of ,103 for the ratio of the brightest image to the central image. For cusped models of lens mass distributions, we have made use of this non-detection to constrain the relation between inner power-law slope , of the lensing galaxy mass profile, and its break radius rb. For rb > 130 pc the power-law slope is required to be close to isothermal (, > 1.8). A flatter inner slope is allowed if a massive black hole is present at the centre of the lensing galaxy, but the effect of the black hole is small unless it is ,10 times more massive than that implied by the relation between black hole mass and stellar velocity dispersion. By comparing four epochs of VLBI observations, we also detected possible superluminal motion in the jet in the brighter image A. The B jet remains unresolved, as expected from a simple lens model of the system. [source] The effect of aging on the dark conductivity and 1/f noise in hydrogenated microcrystalline silicon thin filmsPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 3-4 2010M. Güne Abstract Aging hydrogenated microcrystalline silicon in air is found to affect both the dark conductivity and the 1/f noise. For a sample with a crystalline volume fraction of 0.39, the conductivity decreased by three orders of magnitude at 20 °C after short-term (10,20 hrs) exposure to air. The conductivity recovered after annealing to 160 °C. Long-term exposure (2 years) resulted in a permanent decrease by a factor of 16 at 20 °C even after annealing. Long-term aging also increased the conductivity activation energy from 0.193 eV to 0.342 eV. After short-term aging and below the annealing temperature, the conductivity prefactor ,0 and the activation energy E, follow a Meyer-Neldel type of relation. Conductance fluctuations measured for annealed and aged states show all the expected characteristics of 1/f noise. The spectra fit a power law with slope -1; the slope is not affected by temperature or aging. The magnitude of the noise decreases with temperature after aging, but by much less after annealing. A simple analysis of the product of conductivity and noise magnitude can be used to estimate the free carrier mobility (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] A semi-automated solid-phase extraction liquid chromatography/tandem mass spectrometry method for the analysis of tetrahydrocannabinol and metabolites in whole blood,RAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2009Eshwar Jagerdeo Marijuana is one of the most commonly abused illicit substances in the USA, making cannabinoids important to detect in clinical and forensic toxicology laboratories. Historically, cannabinoids in biological fluids have been derivatized and analyzed by gas chromatography/mass spectrometry (GC/MS). There has been a gradual shift in many laboratories towards liquid chromatography/mass spectrometry (LC/MS) for this analysis due to its improved sensitivity and reduced sample preparation compared with GC/MS procedures. This paper reports a validated method for the analysis of ,9 -tetrahydrocannabinol (THC) and its two main metabolites, 11-nor-9-carboxy-,9 -tetrahydrocannabinol (THC-COOH) and 11-hydroxy-,9 -tetrahydrocannabinol (THC-OH), in whole blood samples. The method has also been validated for cannabinol (CBD) and cannabidiol (CDN), two cannabinoids that were shown not to interfere with the method. This method has been successfully applied to samples both from living people and from deceased individuals obtained during autopsy. This method utilizes online solid-phase extraction (SPE) with LC/MS. Pretreatment of samples involves protein precipitation, sample concentration, ultracentrifugation, and reconstitution. The online SPE procedure was developed using Hysphere C8-EC sorbent. A chromatographic gradient with an Xterra MS C18 column was used for the separation. Four multiple-reaction monitoring (MRM) transitions were monitored for each analyte and internal standard. Linearity generally fell between 2 and 200,ng/mL. The limits of detection (LODs) ranged from 0.5 to 3,ng/mL and the limits of quantitation (LOQs) ranged from 2 to 8,ng/mL. The bias and imprecision were determined using a simple analysis of variance (ANOVA: single factor). The results demonstrate bias as <7%, and imprecision as <9%, for all components at each quantity control level. Published in 2009 by John Wiley & Sons, Ltd. [source] Multiplex pathogen detection based on spatially addressable microarrays of barcoded resinsBIOTECHNOLOGY JOURNAL, Issue 7 2008David R. Blais Abstract Suspension microsphere immunoassays are rapidly gaining recognition in antigen identification and infectious disease biodetection due to their simplicity, versatility and high-throughput multiplex screening. We demonstrate a multiplex assay based on antibody-functionalized barcoded resins (BCRs) to identify pathogen antigens in complex biological fluids. The binding event of a particular antibody on given bead (fluorescence) and the identification of the specific pathogen agent (vibrational fingerprint of the bead) can be achieved in a dispersive Raman system by exciting the sample with two different laser lines. Anthrax protective antigen, Franciscella tularensis lipopolysaccharide and CD14 antigens were accurately identified and quantified in tetraplex assays with a detection limit of 1 ng/mL. The rapid, versatile and simple analysis enabled by the BCRs demonstrates their potential for multiplex antigen detection and identification in a reconfigurable microarray format. [source] | |||||||||||||||||||||||||