Sample records for providing quantitative measurements

  1. Quantitative measures of walking and strength provide insight into brain corticospinal tract pathology in multiple sclerosis

    Directory of Open Access Journals (Sweden)

    Nora E Fritz


    Quantitative measures of strength and walking are associated with brain corticospinal tract pathology. The addition of these quantitative measures to basic clinical information explains more of the variance in corticospinal tract fractional anisotropy and magnetization transfer ratio than the basic clinical information alone. Outcome measurement for multiple sclerosis clinical trials has been notoriously challenging; the use of quantitative measures of strength and walking along with tract-specific imaging methods may improve our ability to monitor disease change over time, with intervention, and provide needed guidelines for developing more effective targeted rehabilitation strategies.

  2. Speech graphs provide a quantitative measure of thought disorder in psychosis.

    Directory of Open Access Journals (Sweden)

    Natalia B Mota

    Full Text Available BACKGROUND: Psychosis has various causes, including mania and schizophrenia. Since the differential diagnosis of psychosis is exclusively based on subjective assessments of oral interviews with patients, an objective quantification of the speech disturbances that characterize mania and schizophrenia is in order. In principle, such quantification could be achieved by the analysis of speech graphs. A graph represents a network with nodes connected by edges; in speech graphs, nodes correspond to words and edges correspond to semantic and grammatical relationships. METHODOLOGY/PRINCIPAL FINDINGS: To quantify speech differences related to psychosis, interviews with schizophrenics, manics and normal subjects were recorded and represented as graphs. Manics scored significantly higher than schizophrenics in ten graph measures. Psychopathological symptoms such as logorrhea, poor speech, and flight of thoughts were grasped by the analysis even when verbosity differences were discounted. Binary classifiers based on speech graph measures sorted schizophrenics from manics with up to 93.8% of sensitivity and 93.7% of specificity. In contrast, sorting based on the scores of two standard psychiatric scales (BPRS and PANSS reached only 62.5% of sensitivity and specificity. CONCLUSIONS/SIGNIFICANCE: The results demonstrate that alterations of the thought process manifested in the speech of psychotic patients can be objectively measured using graph-theoretical tools, developed to capture specific features of the normal and dysfunctional flow of thought, such as divergence and recurrence. The quantitative analysis of speech graphs is not redundant with standard psychometric scales but rather complementary, as it yields a very accurate sorting of schizophrenics and manics. Overall, the results point to automated psychiatric diagnosis based not on what is said, but on how it is said.

  3. A high en-face resolution AS-OCT providing quantitative ability to measure layered corneal opacities (United States)

    Chiu, Yu-Kuang; Chen, Wei-Li; Tsai, Cheng-Tsung; Yang, Chang-Hao; Huang, Sheng-Lung


    An in-vivo anterior-segment optical coherence tomography with sub-micron isotropic resolutions is demonstrated on rat cornea. The opacity of the layered cornea was quantitatively analyzed. The morphology of corneal layers was well-depicted by the en-face image.

  4. Pain in patients with multiple sclerosis: a complex assessment including quantitative and qualitative measurements provides for a disease-related biopsychosocial pain model

    Directory of Open Access Journals (Sweden)

    Michalski D


    Full Text Available Dominik Michalski1,*, Stefanie Liebig1,*, Eva Thomae1,2, Andreas Hinz3, Florian Then Bergh1,21Department of Neurology, 2Translational Centre for Regenerative Medicine (TRM, 3Department of Medical Psychology and Medical Sociology, University of Leipzig, Leipzig, Germany *These authors contributed equallyBackground: Pain of various causes is a common phenomenon in patients with Multiple Sclerosis (MS. A biopsychosocial perspective has proven a useful theoretical construct in other chronic pain conditions and was also started in MS. To support such an approach, we aimed to investigate pain in MS with special emphasis on separating quantitative and qualitative aspects, and its interrelation to behavioral and physical aspects.Materials and methods: Pain intensity (NRS and quality (SES were measured in 38 consecutive outpatients with MS (mean age, 42.0 ± 11.5 years, 82% women. Pain-related behavior (FSR, health care utilization, bodily complaints (GBB-24 and fatigue (WEIMuS were assessed by questionnaires, and MS-related neurological impairment by a standardized neurological examination (EDSS.Results: Mean pain intensity was 4.0 (range, 0–10 and mean EDSS 3.7 (range, 0–8 in the overall sample. Currently present pain was reported by 81.6% of all patients. Disease duration and EDSS did not differ between patients with and without pain and were not correlated to quality or intensity of pain. Patients with pain had significantly higher scores of musculoskeletal complaints, but equal scores of exhaustion, gastrointestinal and cardiovascular complaints. Pain intensity correlated only with physical aspects, whereas quality of pain was additionally associated with increased avoidance, resignation and cognitive fatigue.Conclusion: As in other conditions, pain in MS must be assessed in a multidimensional way. Further research should be devoted to adapt existing models to a MS-specific model of pain.Keywords: pain intensity, quality of pain, pain

  5. Coherent quantitative measures of agricultural risks




    Advantages of quantitative risk measurements in agricultural business are grounded. Coherent methods of production and price risk assessment by modeling stochastic risk factor variations are proposed. Instruments for acceptable and critical risk level measurements are presented by providing an example for sunflower seed production.

  6. Electric Field Quantitative Measurement System and Method (United States)

    Generazio, Edward R. (Inventor)


    A method and system are provided for making a quantitative measurement of an electric field. A plurality of antennas separated from one another by known distances are arrayed in a region that extends in at least one dimension. A voltage difference between at least one selected pair of antennas is measured. Each voltage difference is divided by the known distance associated with the selected pair of antennas corresponding thereto to generate a resulting quantity. The plurality of resulting quantities defined over the region quantitatively describe an electric field therein.

  7. Quantitative roughness measurements with iTIRM

    NARCIS (Netherlands)

    Bijl, R.J.M. van der; Fähnle, O.W.; Brug, H. van; Braat, J.J.M.


    A new method, iTIRM, is used for quantitative surface roughness measurements of ground and polished surfaces and it is shown to be a useful tool for measuring total surface quality instead of individual roughness parameters.

  8. Quantitative Measurement of Oxygen in Microgravity Combustion (United States)

    Silver, Joel A.


    A low-gravity environment, in space or in ground-based facilities such as drop towers, provides a unique setting for studying combustion mechanisms. Understanding the physical phenomena controlling the ignition and spread of flames in microgravity has importance for space safety as well as for better characterization of dynamical and chemical combustion processes which are normally masked by buoyancy and other gravity-related effects. Due to restrictions associated with performing measurements in reduced gravity, diagnostic methods which have been applied to microgravity combustion studies have generally been limited to capture of flame emissions on film or video, laser Schlieren imaging and (intrusive) temperature measurements using thermocouples. Given the development of detailed theoretical models, more sophisticated diagnostic methods are needed to provide the kind of quantitative data necessary to characterize the properties of microgravity combustion processes as well as provide accurate feedback to improve the predictive capabilities of the models. When the demands of space flight are considered, the need for improved diagnostic systems which are rugged, compact, reliable, and operate at low power becomes apparent. The objective of this research is twofold. First, we want to develop a better understanding of the relative roles of diffusion and reaction of oxygen in microgravity combustion. As the primary oxidizer species, oxygen plays a major role in controlling the observed properties of flames, including flame front speed (in solid or liquid flames), extinguishment characteristics, flame size and flame temperature. The second objective is to develop better diagnostics based on diode laser absorption which can be of real value in both microgravity combustion research and as a sensor on-board Spacelab as either an air quality monitor or as part of a fire detection system. In our prior microgravity work, an eight line-of-sight fiber optic system measured

  9. Do quantitative decadal forecasts from GCMs provide decision relevant skill? (United States)

    Suckling, E. B.; Smith, L. A.


    It is widely held that only physics-based simulation models can capture the dynamics required to provide decision-relevant probabilistic climate predictions. This fact in itself provides no evidence that predictions from today's GCMs are fit for purpose. Empirical (data-based) models are employed to make probability forecasts on decadal timescales, where it is argued that these 'physics free' forecasts provide a quantitative 'zero skill' target for the evaluation of forecasts based on more complicated models. It is demonstrated that these zero skill models are competitive with GCMs on decadal scales for probability forecasts evaluated over the last 50 years. Complications of statistical interpretation due to the 'hindcast' nature of this experiment, and the likely relevance of arguments that the lack of hindcast skill is irrelevant as the signal will soon 'come out of the noise' are discussed. A lack of decision relevant quantiative skill does not bring the science-based insights of anthropogenic warming into doubt, but it does call for a clear quantification of limits, as a function of lead time, for spatial and temporal scales on which decisions based on such model output are expected to prove maladaptive. Failing to do so may risk the credibility of science in support of policy in the long term. The performance amongst a collection of simulation models is evaluated, having transformed ensembles of point forecasts into probability distributions through the kernel dressing procedure [1], according to a selection of proper skill scores [2] and contrasted with purely data-based empirical models. Data-based models are unlikely to yield realistic forecasts for future climate change if the Earth system moves away from the conditions observed in the past, upon which the models are constructed; in this sense the empirical model defines zero skill. When should a decision relevant simulation model be expected to significantly outperform such empirical models? Probability

  10. Quantitative phase measurements using optical quadrature microscopy. (United States)

    Rockward, Willie S; Thomas, Anthony L; Zhao, Bing; Dimarzio, Charles A


    Imaging of phase or optical path length is becoming more important with the development of better imaging systems, computational algorithms, faster computers, and a greater interest in the imaging of transparent objects. Early phase imaging involved qualitative imaging of phase gradients. New computational algorithms can be used to extract some quantitative phase imaging from these techniques. In contrast, new hardware has enabled full-field quantitative phase imaging on a practical and cost-effective scale. We explore a quantitative comparison between two techniques for imaging phase. In the first technique, phase is recovered from a pair of differential interference contrast images, and in the second technique, phase is measured pixel-by-pixel interferometrically. It is shown, experimentally, that the overall results are similar, but each technique has its own advantages and disadvantages.

  11. Quantitative Ultrasound Measurements at the Heel

    DEFF Research Database (Denmark)

    Daugschies, M.; Brixen, K.; Hermann, P.


    Calcaneal quantitative ultrasound can be used to predict osteoporotic fracture risk, but its ability to monitor therapy is unclear possibly because of its limited precision. We developed a quantitative ultrasound device (foot ultrasound scanner) that measures the speed of sound at the heel...... with the aim of minimizing common error sources like the position and penetration angle of the ultrasound beam, as well as the soft tissue temperature. To achieve these objectives, we used a receiver array, mechanics to adjust the beam direction and a foot temperature sensor. In a group of 60 volunteers, short......-term precision was evaluated for the foot ultrasound scanner and a commercial device (Achilles Insight, GE Medical, Fairfield, CT, USA). In a subgroup of 20 subjects, mid-term precision (1-mo follow-up) was obtained. Compared with measurement of the speed of sound with the Achilles Insight, measurement...

  12. WetLab-2: Providing Quantitative PCR Capabilities on ISS (United States)

    Parra, Macarena; Jung, Jimmy Kar Chuen; Almeida, Eduardo; Boone, Travis David; Schonfeld, Julie; Tran, Luan Hoang


    The objective of NASA Ames Research Centers WetLab-2 Project is to place on the ISS a system capable of conducting gene expression analysis via quantitative real-time PCR (qRT-PCR) of biological specimens sampled or cultured on orbit. The WetLab-2 system is capable of processing sample types ranging from microbial cultures to animal tissues dissected on-orbit. The project has developed a RNA preparation module that can lyse cells and extract RNA of sufficient quality and quantity for use as templates in qRT-PCR reactions. Our protocol has the advantage that it uses non-toxic chemicals, alcohols or other organics. The resulting RNA is transferred into a pipette and then dispensed into reaction tubes that contain all lyophilized reagents needed to perform qRT-PCR reactions. These reaction tubes are mounted on rotors to centrifuge the liquid to the reaction window of the tube using a cordless drill. System operations require simple and limited crew actions including syringe pushes, valve turns and pipette dispenses. The resulting process takes less than 30 min to have tubes ready for loading into the qRT-PCR unit.The project has selected a Commercial-Off-The-Shelf (COTS) qRT-PCR unit, the Cepheid SmartCycler, that will fly in its COTS configuration. The SmartCycler has a number of advantages including modular design (16 independent PCR modules), low power consumption, rapid thermal ramp times and four-color detection. The ability to detect up to four fluorescent channels will enable multiplex assays that can be used to normalize for RNA concentration and integrity, and to study multiple genes of interest in each module. The WetLab-2 system will have the capability to downlink data from the ISS to the ground after a completed run and to uplink new programs. The ability to conduct qRT-PCR on-orbit eliminates the confounding effects on gene expression of reentry stresses and shock acting on live cells and organisms or the concern of RNA degradation of fixed samples. The

  13. Quantitative shearography in axisymmetric gas temperature measurements (United States)

    VanDerWege, Brad A.; O'Brien, Christopher J.; Hochgreb, Simone


    This paper describes the use of shearing interferometry (shearography) for the quantitative measurement of gas temperatures in axisymmetric systems in which vibration and shock are substantial, and measurement time is limited. The setup and principle of operation of the interferometer are described, as well as Fourier-transform-based fringe pattern analysis, Abel transform, and sensitivity of the phase lead to temperature calculation. A helium jet and a Bunsen burner flame are shown as verification of the diagnostic. The accuracy of the measured temperature profile is shown to be limited by the Abel transform and is critically dependent on the reference temperature used.

  14. Quantitative magnetic measurements with transmission electron microscope

    Energy Technology Data Exchange (ETDEWEB)

    Rusz, Jan, E-mail: jan.rusz@fysik.uu.s [Department of Physics and Materials Science, Uppsala University, Box 530, S-751 21 (Sweden); Lidbaum, Hans [Department of Engineering Sciences, Uppsala University, Box 534, S-751 21 (Sweden); Liebig, Andreas; Hjoervarsson, Bjoergvin; Oppeneer, Peter M. [Department of Physics and Materials Science, Uppsala University, Box 530, S-751 21 (Sweden); Rubino, Stefano [Department of Engineering Sciences, Uppsala University, Box 534, S-751 21 (Sweden); Eriksson, Olle [Department of Physics and Materials Science, Uppsala University, Box 530, S-751 21 (Sweden); Leifer, Klaus [Department of Engineering Sciences, Uppsala University, Box 534, S-751 21 (Sweden)


    We briefly review the state-of-the-art electron magnetic chiral dichroism experiments and theory with focus on quantitative measurements of the atom-specific orbital to spin moment ratio m{sub l}/m{sub s}. Our approach of quantitative method, based on reciprocal space mapping of the magnetic signal, is described. We discuss additional symmetry considerations for m{sub l}/m{sub s} measurements, which are present due to dynamical diffraction effects. These lead to a preference for the 3-beam orientation of the sample. Further on, we describe a method of correcting asymmetries present due to imperfect 3-beam orientation-the so-called double-difference correction.

  15. Quantitative tomographic measurements of opaque multiphase flows

    Energy Technology Data Exchange (ETDEWEB)



    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  16. Quantitative Measurements using Ultrasound Vector Flow Imaging

    DEFF Research Database (Denmark)

    Jensen, Jørgen Arendt


    L/stroke (true: 1.15 mL/stroke, bias: 12.2%). Measurements down to 160 mm were obtained with a relative standard deviation and bias of less than 10% for the lateral component for stationary, parabolic flow. The method can, thus, find quantitative velocities, angles, and volume flows at sites currently......Duplex Vector Flow Imaging (VFI) imaging is introduced as a replacement for spectral Doppler, as it automatically can yield fully quantitative flow estimates without angle correction. Continuous VFI data over 9 s for 10 pulse cycles were acquired by a 3 MHz convex probe connected to the SARUS...... scanner for pulsating flow mimicking the femoral artery from a CompuFlow 1000 pump (Shelley Medical). Data were used in four estimators based on directional transverse oscillation for velocity, flow angle, volume flow, and turbulence estimation and their respective precisions. An adaptive lag scheme gave...

  17. Quantitative Fluorescence Measurements with Multicolor Flow Cytometry. (United States)

    Wang, Lili; Gaigalas, Adolfas K; Wood, James


    Multicolor flow cytometer assays are routinely used in clinical laboratories for immunophenotyping, monitoring disease and treatment, and determining prognostic factors. However, existing methods for quantitative measurements have not yet produced satisfactory results independent of flow cytometers used. This chapter details a procedure for quantifying surface and intracellular protein biomarkers by calibrating the output of a multicolor flow cytometer in units of antibodies bound per cell (ABC). The procedure includes the following critical steps: (a) quality control (QC) and performance characterization of the multicolor flow cytometer, (b) fluorescence calibration using hard dyed microspheres assigned with fluorescence intensity values in equivalent number of reference fluorophores (ERF), (c) compensation for correction of fluorescence spillover, and (d) application of a biological reference standard for translating the ERF scale to the ABC scale. The chapter also points out current efforts for implementing quantification of biomarkers in a manner which is independent of instrument platforms and reagent differences.

  18. Quantitative Measurement of Out-of-plane Displacement Using Shearography

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Jung Gu; Kim, Kyung Suk; Beack, Sang Kyu; Jang, Ho Sub [Chosun University, Gwangju (Korea, Republic of); Choi, Jung Suk [Mokpo Science College, Mokpo (Korea, Republic of)


    Electronic Speckle Pattern Interferometry is a common method for measuring out-of-plane displacement and in-plane displacement and applied for vibration analysis and strain/stress analysis. However, ESPI is sensitive to environmental disturbance, which provide the limitation of industrial application. On the other hand, Shearography based on shearing interferometer can directly measure the first derivative of out-of-plane displacement, which is insensitive to vibration disturbance. This paper proposes the out-of-plane displacement extraction technique from results of Shearography by numerical processing and measurement results of ESPI and Shearoraphy are compared quantitatively.

  19. A quantitative measure for protein conformational heterogeneity. (United States)

    Lyle, Nicholas; Das, Rahul K; Pappu, Rohit V


    Conformational heterogeneity is a defining characteristic of proteins. Intrinsically disordered proteins (IDPs) and denatured state ensembles are extreme manifestations of this heterogeneity. Inferences regarding globule versus coil formation can be drawn from analysis of polymeric properties such as average size, shape, and density fluctuations. Here we introduce a new parameter to quantify the degree of conformational heterogeneity within an ensemble to complement polymeric descriptors. The design of this parameter is guided by the need to distinguish between systems that couple their unfolding-folding transitions with coil-to-globule transitions and those systems that undergo coil-to-globule transitions with no evidence of acquiring a homogeneous ensemble of conformations upon collapse. The approach is as follows: Each conformation in an ensemble is converted into a conformational vector where the elements are inter-residue distances. Similarity between pairs of conformations is quantified using the projection between the corresponding conformational vectors. An ensemble of conformations yields a distribution of pairwise projections, which is converted into a distribution of pairwise conformational dissimilarities. The first moment of this dissimilarity distribution is normalized against the first moment of the distribution obtained by comparing conformations from the ensemble of interest to conformations drawn from a Flory random coil model. The latter sets an upper bound on conformational heterogeneity thus ensuring that the proposed measure for intra-ensemble heterogeneity is properly calibrated and can be used to compare ensembles for different sequences and across different temperatures. The new measure of conformational heterogeneity will be useful in quantitative studies of coupled folding and binding of IDPs and in de novo sequence design efforts that are geared toward controlling the degree of heterogeneity in unbound forms of IDPs.

  20. Can Composite Measures Provide a Different Perspective on Provider Performance Than Individual Measures? (United States)

    Shwartz, Michael; Rosen, Amy K; Burgess, James F


    Composite measures, which aggregate performance on individual measures into a summary score, are increasingly being used to evaluate facility performance. There is little understanding of the unique perspective that composite measures provide. To examine whether high/low (ie, high or low) performers on a composite measures are also high/low performers on most of the individual measures that comprise the composite. We used data from 2 previous studies, one involving 5 measures from 632 hospitals and one involving 28 measures from 112 Veterans Health Administration (VA) nursing homes; and new data on hospital readmissions for 3 conditions from 131 VA hospitals. To compare high/low performers on a composite to high/low performers on the component measures, we used 2-dimensional tables to categorize facilities into high/low performance on the composite and on the individual component measures. In the first study, over a third of the 162 hospitals in the top quintile based on the composite were in the top quintile on at most 1 of the 5 individual measures. In the second study, over 40% of the 27 high-performing nursing homes on the composite were high performers on 8 or fewer of the 28 individual measures. In the third study, 20% of the 61 low performers on the composite were low performers on only 1 of the 3 individual measures. Composite measures can identify as high/low performers facilities that perform "pretty well" (or "pretty poorly") across many individual measures but may not be high/low performers on most of them.

  1. Quantitative Measures of Mineral Supply Risk (United States)

    Long, K. R.


    Almost all metals and many non-metallic minerals are traded internationally. An advantage of global mineral markets is that minerals can be obtained from the globally lowest-cost source. For example, one rare-earth element (REE) mine in China, Bayan Obo, is able to supply most of world demand for rare earth elements at a cost significantly less than its main competitors. Concentration of global supplies at a single mine raises significant political risks, illustrated by China’s recent decision to prohibit the export of some REEs and severely limit the export of others. The expected loss of REE supplies will have a significant impact on the cost and production of important national defense technologies and on alternative energy programs. Hybrid vehicles and wind-turbine generators, for example, require REEs for magnets and batteries. Compact fluorescent light bulbs use REE-based phosphors. These recent events raise the general issue of how to measure the degree of supply risk for internationally sourced minerals. Two factors, concentration of supply and political risk, must first be addressed. Concentration of supply can be measured with standard economic tools for measuring industry concentration, using countries rather than firms as the unit of analysis. There are many measures of political risk available. That of the OECD is a measure of a country’s commitment to rule-of-law and enforcement of contracts, as well as political stability. Combining these measures provides a comparative view of mineral supply risk across commodities and identifies several minerals other than REEs that could suddenly become less available. Combined with an assessment of the impact of a reduction in supply, decision makers can use these measures to prioritize risk reduction efforts.

  2. Quantitative Measurement of the Digital Divide (United States)

    Cottrell, Roger


    Bandwidth and the Internet infrastructure are the life-blood of the world's knowledge economy, but they are often scarcest where most needed. Measuring the numbers of users of the Internet infrastructure is not easy in developing countries because many people share accounts, use corporate and academic networks, or visit the rapidly growing number of cyber cafes, telecentres and business services. Also measuring the number of users does not take into account the level of use. One valuable indicator for measuring the Internet infrastructure is the international Internet performance of a country or region. One of the major aims of the PingER project is to provide an historical archive of extensive, publicly accessible, up-to-date, measurements, analyses and reports of multiple Internet performance indicators (such as delay, loss, throughput, reachability, and jitter) between sites, countries and regions of the world. This talk will briefly describe the PingER project and then compare and contrast the Internet performance and its trends within and between countries and regions of the world. By means of extensive case studies it will also identify which regions need the greatest attention, together with their major issues and possible approaches to reducing the divide.

  3. Quantitative proton MR techniques for measuring fat. (United States)

    Hu, H H; Kan, H E


    Accurate, precise and reliable techniques for the quantification of body and organ fat distributions are important tools in physiology research. They are critically needed in studies of obesity and diseases involving excess fat accumulation. Proton MR methods address this need by providing an array of relaxometry-based (T1, T2) and chemical shift-based approaches. These techniques can generate informative visualizations of regional and whole-body fat distributions, yield measurements of fat volumes within specific body depots and quantify fat accumulation in abdominal organs and muscles. MR methods are commonly used to investigate the role of fat in nutrition and metabolism, to measure the efficacy of short- and long-term dietary and exercise interventions, to study the implications of fat in organ steatosis and muscular dystrophies and to elucidate pathophysiological mechanisms in the context of obesity and its comorbidities. The purpose of this review is to provide a summary of mainstream MR strategies for fat quantification. The article succinctly describes the principles that differentiate water and fat proton signals, summarizes the advantages and limitations of various techniques and offers a few illustrative examples. The article also highlights recent efforts in the MR of brown adipose tissue and concludes by briefly discussing some future research directions. Copyright © 2013 John Wiley & Sons, Ltd.

  4. Quantitative measurements of autobiographical memory content.

    Directory of Open Access Journals (Sweden)

    Robert S Gardner

    Full Text Available Autobiographical memory (AM, subjective recollection of past experiences, is fundamental in everyday life. Nevertheless, characterization of the spontaneous occurrence of AM, as well as of the number and types of recollected details, remains limited. The CRAM (Cue-Recalled Autobiographical Memory test ( adapts and combines the cue-word method with an assessment that collects counts of details recalled from different life periods. The SPAM (Spontaneous Probability of Autobiographical Memories protocol samples introspection during everyday activity, recording memory duration and frequency. These measures provide detailed, naturalistic accounts of AM content and frequency, quantifying essential dimensions of recollection. AM content (∼20 details/recollection decreased with the age of the episode, but less drastically than the probability of reporting remote compared to recent memories. AM retrieval was frequent (∼20/hour, each memory lasting ∼30 seconds. Testable hypotheses of the specific content retrieved in a fixed time from given life periods are presented.

  5. Quantitative Method of Measuring Metastatic Activity (United States)

    Morrison, Dennis R. (Inventor)


    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated uroldnase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  6. Auroral Electrojet Index Designed to Provide a Global Measure, Hourly Intervals, of Auroral Zone Magnetic Activity (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Auroral Electrojet (AE) index is designed to provide a global quantitative measure of auroral zone magnetic activity produced by enhanced ionospheric currents...

  7. Smile line assessment comparing quantitative measurement and visual estimation

    NARCIS (Netherlands)

    Geld, P. Van der; Oosterveld, P.; Schols, J.; Kuijpers-Jagtman, A.M.


    INTRODUCTION: Esthetic analysis of dynamic functions such as spontaneous smiling is feasible by using digital videography and computer measurement for lip line height and tooth display. Because quantitative measurements are time-consuming, digital videography and semiquantitative (visual) estimation

  8. Quantitative shape measurements of distal volcanic ash

    National Research Council Canada - National Science Library

    Colleen M. Riley; William I. Rose; Gregg J. S. Bluth


    ...‐shaped particles affect transport processes and radiative transfer measurements. In this study, a methodology was developed to characterize particle shapes, sizes, and terminal velocities for three ash samples of different compositions...

  9. Quantitative Thermochemical Measurements in High-Pressure Gaseous Combustion (United States)

    Kojima, Jun J.; Fischer, David G.


    We present our strategic experiment and thermochemical analyses on combustion flow using a subframe burst gating (SBG) Raman spectroscopy. This unconventional laser diagnostic technique has promising ability to enhance accuracy of the quantitative scalar measurements in a point-wise single-shot fashion. In the presentation, we briefly describe an experimental methodology that generates transferable calibration standard for the routine implementation of the diagnostics in hydrocarbon flames. The diagnostic technology was applied to simultaneous measurements of temperature and chemical species in a swirl-stabilized turbulent flame with gaseous methane fuel at elevated pressure (17 atm). Statistical analyses of the space-/time-resolved thermochemical data provide insights into the nature of the mixing process and it impact on the subsequent combustion process in the model combustor.

  10. Semi-automated quantitative Drosophila wings measurements. (United States)

    Loh, Sheng Yang Michael; Ogawa, Yoshitaka; Kawana, Sara; Tamura, Koichiro; Lee, Hwee Kuan


    Drosophila melanogaster is an important organism used in many fields of biological research such as genetics and developmental biology. Drosophila wings have been widely used to study the genetics of development, morphometrics and evolution. Therefore there is much interest in quantifying wing structures of Drosophila. Advancement in technology has increased the ease in which images of Drosophila can be acquired. However such studies have been limited by the slow and tedious process of acquiring phenotypic data. We have developed a system that automatically detects and measures key points and vein segments on a Drosophila wing. Key points are detected by performing image transformations and template matching on Drosophila wing images while vein segments are detected using an Active Contour algorithm. The accuracy of our key point detection was compared against key point annotations of users. We also performed key point detection using different training data sets of Drosophila wing images. We compared our software with an existing automated image analysis system for Drosophila wings and showed that our system performs better than the state of the art. Vein segments were manually measured and compared against the measurements obtained from our system. Our system was able to detect specific key points and vein segments from Drosophila wing images with high accuracy.

  11. The GRIT: a quantitative measure of ulnar impaction syndrome. (United States)

    LaStayo, P; Weiss, S


    The gripping rotatory impaction test (GRIT) is performed with a standard grip dynamometer and provides a quantitative measure for identifying ulnar impaction. The purpose of this study was to determine whether patients with unilateral ulnar impaction syndrome (UIS) have a GRIT ratio on the involved side greater than 1.0 while the GRIT ratio on the uninvolved side is no different from 1.0. Twenty-four patients with unilateral UIS were tested with the GRIT on both the symptomatic, involved side and the asymptomatic, uninvolved side. The GRIT was performed with a standard grip dynamometer, and testing alternated between each patient's involved and uninvolved sides, with the wrist in the neutral, supinated, and pronated positions, in that order. The GRIT ratio on the involved side, at 1.37, was significantly greater than 1.0, while the GRIT ratio on the uninvolved side, at 1.03, was not significantly different from 1.0. The GRIT ratio is a quantitative measure that identifies UIS and can be used as an adjunct to imaging studies and qualitative clinical tests for UIS. The GRIT may also be helpful in determining which patients with UIS might benefit from surgical ulnar shortening.

  12. Quantitative measurements of autofluorescence with the scanning laser ophthalmoscope. (United States)

    Delori, François; Greenberg, Jonathan P; Woods, Russell L; Fischer, Jörg; Duncker, Tobias; Sparrow, Janet; Smith, R Theodore


    To evaluate the feasibility and reliability of a standardized approach for quantitative measurements of fundus autofluorescence (AF) in images obtained with a confocal scanning laser ophthalmoscope (cSLO). AF images (30°) were acquired in 34 normal subjects (age range, 20-55 years) with two different cSLOs (488-nm excitation) equipped with an internal fluorescent reference to account for variable laser power and detector sensitivity. The gray levels (GLs) of each image were calibrated to the reference, the zero GL, and the magnification, to give quantified autofluorescence (qAF). Images from subjects and fixed patterns were used to test detector linearity with respect to fluorescence intensity, the stability of qAF with change in detector gain, field uniformity, effect of refractive error, and repeatability. qAF was independent of detector gain and laser power over clinically relevant ranges, provided that detector gain was adjusted to maintain exposures within the linear detection range (GL instruments was Quantitative AF imaging appears feasible. It may enhance understanding of retinal degeneration, serve as a diagnostic aid and as a sensitive marker of disease progression, and provide a tool to monitor the effects of therapeutic interventions.

  13. A molecular ruler for measuring quantitative distance distributions.

    Directory of Open Access Journals (Sweden)

    Rebecca S Mathew-Fenn

    Full Text Available We report a novel molecular ruler for measurement of distances and distance distributions with accurate external calibration. Using solution X-ray scattering we determine the scattering interference between two gold nanocrystal probes attached site-specifically to a macromolecule of interest. Fourier transformation of the interference pattern provides a model-independent probability distribution for the distances between the probe centers-of-mass. To test the approach, we measure end-to-end distances for a variety of DNA structures. We demonstrate that measurements with independently prepared samples and using different X-ray sources are highly reproducible, we demonstrate the quantitative accuracy of the first and second moments of the distance distributions, and we demonstrate that the technique recovers complex distribution shapes. Distances measured with the solution scattering-interference ruler match the corresponding crystallographic values, but differ from distances measured previously with alternate ruler techniques. The X-ray scattering interference ruler should be a powerful tool for relating crystal structures to solution structures and for studying molecular fluctuations.

  14. Peptide-Centric Approaches Provide an Alternative Perspective To Re-Examine Quantitative Proteomic Data. (United States)

    Ning, Zhibin; Zhang, Xu; Mayne, Janice; Figeys, Daniel


    Quantitative proteomics can provide rich information on changes in biological functions and processes. However, its accuracy is affected by the inherent information degeneration found in bottom-up proteomics. Therefore, the precise protein inference from identified peptides can be mistaken since an ad hoc rule is used for generating a list of protein groups that depends on both the sample type and the sampling depth. Herein, we propose an alternative approach for examining quantitative proteomic data which is peptide-centric instead of protein-centric. We discuss the feasibility of the peptide-centric approach which was tested on several quantitative proteomic data sets. We show that peptide-centric quantification has several advantages over protein level analysis: (1) it is more sensitive for sample segregation, (2) it avoids the issues associated with protein inference, and (3) it can retrieve significant peptides lost in protein-centric quantification for further downstream analysis.

  15. A Quantitative Measure of Relevance Based on Kelly Gambling Theory

    NARCIS (Netherlands)

    Madsen, M.W.; Colinet, M.; Katrenko, S.; Rendsvig, R.K.


    This paper proposes a quantitative measure relevance which can quantify the difference between useful and useless facts. This measure evaluates sources of information according to how they affect the expected logarithmic utility of an agent. A number of reasons are given why this is often preferable

  16. Providing Open-Access Know How for Directors of Quantitative and Mathematics Support Centers

    Directory of Open Access Journals (Sweden)

    Michael Schuckers


    Full Text Available The purpose of this editorial is to introduce the quantitative literacy community to the newly published A Handbook for Directors of Quantitative and Mathematics Centers. QMaSCs (pronounced “Q-masks” can be broadly defined as centers that have supporting students in quantitative fields of study as part of their mission. Some focus only on calculus or mathematics; others concentrate on numeracy or quantitative literacy, and some do all of that. A QMaSC may be embedded in a mathematics department, or part of a learning commons, or a stand-alone center. There are hundreds of these centers in the U.S. The new handbook, which is the outgrowth of a 2013 NSF-sponsored, national workshop attended by 23 QMaSC directors from all quarters of the U.S., is available open access on the USF Scholar Commons and in hard copy from This editorial by the handbook’s editors provides background and overview of the 20 detailed chapters on center leadership and management; community interactions; staffing, hiring and training; center assessment; and starting a center; and then a collection of ten case studies from research universities, four-year state colleges, liberal arts colleges, and a community college. The editorial ends by pointing out the need and potential benefits of a professional organization for QMaSC directors.

  17. Is Quantitative HBsAg Measurement a Reliable Substitute for HBV DNA Quantitation?

    Directory of Open Access Journals (Sweden)

    Mohammad Reza Mahdavi


    Conclusion: There are many factors affecting the correlation between serum HBV DNA copy number and HBsAg level such as genotype of HBV virus, phase of infection, methods of measurement, HBeAg status, and drug and types of treatment procedures. Therefore, these factors should be considered in further studies dealing with the correlation between quantitative HBV DNA and HBsAg tests.

  18. Measuring stigma among abortion providers: assessing the Abortion Provider Stigma Survey instrument. (United States)

    Martin, Lisa A; Debbink, Michelle; Hassinger, Jane; Youatt, Emily; Eagen-Torkko, Meghan; Harris, Lisa H


    We explored the psychometric properties of 15 survey questions that assessed abortion providers' perceptions of stigma and its impact on providers' professional and personal lives referred to as the Abortion Provider Stigma Survey (APSS). We administered the survey to a sample of abortion providers recruited for the Providers' Share Workshop (N = 55). We then completed analyses using Stata SE/12.0. Exploratory factor analysis, which resulted in 13 retained items and identified three subscales: disclosure management, resistance and resilience, and discrimination. Stigma was salient in abortion provider's lives: they identified difficulties surrounding disclosure (66%) and felt unappreciated by society (89%). Simultaneously, workers felt they made a positive contribution to society (92%) and took pride in their work (98%). Paired t-test analyses of the pre- and post-Workshop APSS scores showed no changes in the total score. However, the Disclosure Management subscale scores were significantly lower (indicating decreased stigma) for two subgroups of participants: those over the age of 30 and those with children. This analysis is a promising first step in the development of a quantitative tool for capturing abortion providers' experiences of and responses to pervasive abortion stigma.

  19. Quantitative measurement of mixtures by terahertz time–domain ...

    Indian Academy of Sciences (India)


    515. *For correspondence. Quantitative measurement of mixtures by terahertz time–domain spectroscopy. GUIFENG LIU a,b. , ZENGYAN ZHANG a. , SHIHUA MA a. , HONGWEI ZHAO a. ,. XIAOJING MA a and WENFENG WANG a,. * a. Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800 ...

  20. Quantitative Measurement of Trans-Fats by Infrared Spectroscopy (United States)

    Walker, Edward B.; Davies, Don R.; Campbell, Mike


    Trans-fat is a general term, which is mainly used to describe the various trans geometric isomers present in unsaturated fatty acids. Various techniques are now used for a quantitative measurement of the amount of trans-fats present in foods and cooking oil.

  1. Measuring Filament Orientation: A New Quantitative, Local Approach (United States)

    Green, C.-E.; Dawson, J. R.; Cunningham, M. R.; Jones, P. A.; Novak, G.; Fissel, L. M.


    The relative orientation between filamentary structures in molecular clouds and the ambient magnetic field provides insight into filament formation and stability. To calculate the relative orientation, a measurement of filament orientation is first required. We propose a new method to calculate the orientation of the one-pixel-wide filament skeleton that is output by filament identification algorithms such as filfinder. We derive the local filament orientation from the direction of the intensity gradient in the skeleton image using the Sobel filter and a few simple post-processing steps. We call this the “Sobel-gradient method.” The resulting filament orientation map can be compared quantitatively on a local scale with the magnetic field orientation map to then find the relative orientation of the filament with respect to the magnetic field at each point along the filament. It can also be used for constructing radial profiles for filament width fitting. The proposed method facilitates automation in analyses of filament skeletons, which is imperative in this era of “big data.”

  2. Quantitative magnetization transfer provides information complementary to grey matter atrophy in Alzheimer's disease brains. (United States)

    Giulietti, Giovanni; Bozzali, Marco; Figura, Viviana; Spanò, Barbara; Perri, Roberta; Marra, Camillo; Lacidogna, Giordano; Giubilei, Franco; Caltagirone, Carlo; Cercignani, Mara


    Preliminary studies, based on a region-of-interest approach, suggest that quantitative magnetization transfer (qMT), an extension of magnetization transfer imaging, provides complementary information to conventional magnetic resonance imaging (MRI) in the characterisation of Alzheimer's disease (AD). The aim of this study was to extend these findings to the whole brain, using a voxel-wise approach. We recruited 19AD patients and 11 healthy subjects (HS). All subjects had an MRI acquisition at 3.0T including a T(1)-weighted volume, 12 MT-weighted volumes for qMT, and data for computing T(1) and B(1) maps. The T(1)-weighted volumes were processed to yield grey matter (GM) volumetric maps, while the other sequences were used to compute qMT parametric maps of the whole brain. qMT maps were warped to standard space and smoothed, and subsequently compared between groups. Of all the qMT parameters considered, only the forward exchange rate, RM(0)(B), showed significant group differences. These images were therefore retained for the multimodal statistical analysis, designed to locate brain regions of RM(0)(B) differences between AD and HS groups, adjusting for local GM atrophy. Widespread areas of reduced RM(0)(B) were found in AD patients, mainly located in the hippocampus, in the temporal lobe, in the posterior cingulate and in the parietal cortex. These results indicate that, among qMT parameters, RM(0)(B) is the most sensitive to AD pathology. This quantity is altered in the hippocampus of patients with AD (as found by previous works) but also in other brain areas, that PET studies have highlighted as involved with both, reduced glucose metabolism and amyloid β deposition. RM(0)(B) might reflect, through the measurement of the efficiency of MT exchange, some information with a specific pathological counterpart. Given previous evidence of a strict relationship between RM(0)(B) and intracellular pH, an intriguing speculation is that our findings might reflect metabolic

  3. The Kety-Schmidt Technique for Quantitative Perfusion and Oxygen Metabolism Measurements in the MR Environment (United States)

    Lee, John J.; Powers, William J.; Faulkner, Chad B.; Boyle, Patrick J.; Derdeyn, Colin P.


    The Kety-Schmidt technique provides quantitative measurement of whole brain cerebral blood flow (CBF). CBF is measured as the area between the arterial and venous washout curves of a diffusible tracer. Oxygen extraction and metabolism may be calculated from arterial and venous samples. In this report we present a method for performing these measurements in an MR environment. This technique could be useful for validation of MR methods of hemodynamic and metabolic measurements in humans. PMID:22997166

  4. Development of a method for quantitative measures of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Chreiteh, Shadi Samir


    applicable description of quantitative methods for measuring lumbar disc herniations and related structures on sagittal MRIs. The objectives of this study were: 1) to develop methods for quantitative measures of intervertebral discs, lumbar disc herniations and dural sac/spinal canal using MRIs, 2......Background: Detailed information about the development of disc morphology over time could provide valuable knowledge about disc health when compared with clinical measures such as pain and activity limitation. However, a review of the available literature did not reveal any detailed and directly......) to evaluate the agreement of these methods, and 3) to identify factors in the measurement procedures that may compromise agreement. Methods: In this intra- and inter-rater agreement study, lumbar quantitative measurements were performed on magnetic resonance images from 32 participants from a study cohort...

  5. Distal Radius Quantitative Ultrasound Measurements and Related Factors

    Directory of Open Access Journals (Sweden)

    Özden Özyemiflçi Taflk›ran


    Full Text Available Aim: To investigate the quantitative ultrasound measurements and determine the related demographic, clinical and life style parameters. Material and Methods: A questionnaire including demographic features, systemic diseases, physical activity levels and other risk factors for osteoporosis was completed. Measurements of quantitative ultrasound (QUS were performed. Speed of sound (SOS (m/sec measurements were taken at the distal 1/3 radius of the nondominant extremity. Results: Among 2347 persons whom QUS measurements and questionnaires were completed, those aged 35 years and older and that were not taking antiosteoporotic treatment (N= 1867; 1654 women, 213 men were included for the analysis. Mean age of the participants were 52.1±10.7 years and mean SOS scores were 4142.8±185.8 m/sec. The variables that were statistically significant in either independent samples t test or analysis of variance were put in the linear regression analysis. In women, age, years since menopause and duration of lactation were independent predictors for SOS scores (constant= 4367.9 m/sec, age B: -3.8, ß: -0.197, p: 0.01; years since menopause: B: -3.9, ß: -0.211, p: 0.006; duration of lactation B: -0.4, ß: -0.086, p: 0.037. In men, age and level of education affected SOS scores independently (constant= 4271.3 m/sec, age B: -3.8, ß: -0.277, p: 0.001; level of education: B: 18.8, ß: 0.144, p: 0.036. Conclusion: Increasing age is associated with decrements in speed of sound measured by quantitative ultrasound at distal radius. It is important to give education about preventive measures on bone metabolism, especially during the lactation period. (Turkish Journal of Osteoporosis 2011;17:1-5

  6. Performance of the provider satisfaction inventory to measure provider satisfaction with diabetes care. (United States)

    Montori, Victor M; Tweedy, Deborah A; Vogelsang, Debra A; Schryver, Patricia G; Naessens, James M; Smith, Steven A


    To develop and validate an inventory to measure provider satisfaction with diabetes management. Using the Mayo Clinic Model of Care, a review of the literature, and expert input, we developed a 4-category (chronic disease management, collaborative team practice, outcomes, and supportive environment), 29-item, 7-point-per-item Provider Satisfaction Inventory (PSI). For evaluation of the PSI, we mailed the survey to 192 primary-care and specialized providers from 8 practice sites (of whom 60 primary-care providers were participating in either usual or planned diabetes care). The Cronbach a score was used to assess the instrument's internal reliability. Participating providers indicated satisfaction or dissatisfaction with management of chronic disease by responding to 29 statements. The response rate was 58%. In each category, the Cronbach a score ranged from 0.71 to 0.90. Providers expressed satisfaction with patient-physician relationships, with the contributions of the nurse educator to the team, and with physician leadership. Providers were dissatisfied with their ability to spend adequate time with the patient (3.6 +/- 1.4), their ability to give patients with diabetes necessary personal attention (4.1 +/- 1.2), the efficient passing of communication (4.3 +/- 1.2), and the opportunities for input to change practice (4.3 +/- 1.6). No statistically significant difference (P = 0.12) was found in mean total scores between planned care (5.0 +/- 0.5) and usual care (4.7 +/- 0.6) providers. Moreover, no significant differences were noted across practice sites. The PSI is a reliable and preliminarily valid instrument for measuring provider satisfaction with diabetes care. Use in research and quality improvement activities awaits further validation.

  7. Quantitative angle-independent flow measurement using relative standard deviation OCT (Conference Presentation) (United States)

    Zhang, Buyun; Zhu, Jiang; Qi, Li; Gao, Yiwei; Huo, Tiancheng; Zhu, Zhuqing; Chen, Zhongping


    Incorporating different data processing methods, Optical coherence tomography (OCT) has the ability for high-resolution micro-angiography and quantitative flow velocity measurement. However, OCT micro-angiography cannot provide quantitative measurement of flow velocity, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which are difficult for whole vascular network. In this study, we report a relative standard deviation OCT (RSD-OCT) for the mapping of the flow velocity in a vascular network without the calculation of Doppler angle. From the theoretical analysis and experimental validation, the RSD-OCT is angle-independent and can quantify the flow velocity conveniently after a calibration.

  8. Bone morphometry and mineral density measurement using quantitative computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Jacobson, D.R.


    Application of computed tomography (CT) to the study of bone structure and density was explored and developed. A review of bone mineral densitometry (BMD) methodology and general principles of quantitative CT (QCT) are presented. A method for QCT of the spine was developed using a flexible tissue equivalent reference placed adjacent to the patient. A methodology for the development and production of tissue equivalent materials is also presented. Patient equivalent phantoms were used to characterize the method, and phantom studies were performed at five clinical sites. A protocol is defined for measuring the inside diameter of the lumbar pedicular canal. Data generated from this study has proven invaluable in the planning for lumbar fusion surgery when screws are to be used for immobilization. Pedicular canal data from 33 patients is presented. QCT was also used to quantify several parameters of the femoral shaft for use in hip replacement surgical planning. Parameters studied include inside diameter, BMD, endosteal BMD and proximal shaft morphology. The structure and trabecular BMD of the proximal femur was extensively studied using QCT. A large variation was found in the fat content of marrow within the proximal femur, and phantom studies were performed to quantify the effect of fat on trabecular QCT BMD. Cadaveric trabecular bone samples with marrow were analyzed physically to determine water, fat, non-fat soft tissue, and ash content. Multiple thin-slice CT studies were performed on cadaveric femurs. A structural model of the proximal femur was developed in which the structural support is provided primarily by trabecular bone. This model may have profound implications in the study of femoral fractures and prosthetic hardware design.

  9. Quantitative angle-insensitive flow measurement using relative standard deviation OCT. (United States)

    Zhu, Jiang; Zhang, Buyun; Qi, Li; Wang, Ling; Yang, Qiang; Zhu, Zhuqing; Huo, Tiancheng; Chen, Zhongping


    Incorporating different data processing methods, optical coherence tomography (OCT) has the ability for high-resolution angiography and quantitative flow velocity measurements. However, OCT angiography cannot provide quantitative information of flow velocities, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which is a challenge in a complex vascular network. In this study, we report on a relative standard deviation OCT (RSD-OCT) method which provides both vascular network mapping and quantitative information for flow velocities within a wide range of Doppler angles. The RSD values are angle-insensitive within a wide range of angles, and a nearly linear relationship was found between the RSD values and the flow velocities. The RSD-OCT measurement in a rat cortex shows that it can quantify the blood flow velocities as well as map the vascular network in vivo .

  10. Quantitative angle-insensitive flow measurement using relative standard deviation OCT (United States)

    Zhu, Jiang; Zhang, Buyun; Qi, Li; Wang, Ling; Yang, Qiang; Zhu, Zhuqing; Huo, Tiancheng; Chen, Zhongping


    Incorporating different data processing methods, optical coherence tomography (OCT) has the ability for high-resolution angiography and quantitative flow velocity measurements. However, OCT angiography cannot provide quantitative information of flow velocities, and the velocity measurement based on Doppler OCT requires the determination of Doppler angles, which is a challenge in a complex vascular network. In this study, we report on a relative standard deviation OCT (RSD-OCT) method which provides both vascular network mapping and quantitative information for flow velocities within a wide range of Doppler angles. The RSD values are angle-insensitive within a wide range of angles, and a nearly linear relationship was found between the RSD values and the flow velocities. The RSD-OCT measurement in a rat cortex shows that it can quantify the blood flow velocities as well as map the vascular network in vivo.

  11. Auroral Electrojet Indices Designed to Provide a Global Measure, 2.5-Minute Intervals, of Auroral Zone Magnetic Activity (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Auroral Electrojet index (AE) is designed to provide a global quantitative measure of auroral zone magnetic activity produced by enhanced ionospheric currents...

  12. Auroral Electrojet Index Designed to Provide a Global Measure, l-minute Intervals, of Auroral Zone Magnetic Activity (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Auroral Electrojet index (AE) is designed to provide a global quantitative measure of auroral zone magnetic activity produced by enhanced ionospheric currents...

  13. A quantitative method for measuring the quality of history matches

    Energy Technology Data Exchange (ETDEWEB)

    Shaw, T.S. [Kerr-McGee Corp., Oklahoma City, OK (United States); Knapp, R.M. [Univ. of Oklahoma, Norman, OK (United States)


    History matching can be an efficient tool for reservoir characterization. A {open_quotes}good{close_quotes} history matching job can generate reliable reservoir parameters. However, reservoir engineers are often frustrated when they try to select a {open_quotes}better{close_quotes} match from a series of history matching runs. Without a quantitative measurement, it is always difficult to tell the difference between a {open_quotes}good{close_quotes} and a {open_quotes}better{close_quotes} matches. For this reason, we need a quantitative method for testing the quality of matches. This paper presents a method for such a purpose. The method uses three statistical indices to (1) test shape conformity, (2) examine bias errors, and (3) measure magnitude of deviation. The shape conformity test insures that the shape of a simulated curve matches that of a historical curve. Examining bias errors assures that model reservoir parameters have been calibrated to that of a real reservoir. Measuring the magnitude of deviation assures that the difference between the model and the real reservoir parameters is minimized. The method was first tested on a hypothetical model and then applied to published field studies. The results showed that the method can efficiently measure the quality of matches. It also showed that the method can serve as a diagnostic tool for calibrating reservoir parameters during history matching.

  14. Ultrasound attenuation as a quantitative measure of fracture healing (United States)

    Gheduzzi, Sabina; Humphrey, Victor F.; Dodd, Simon P.; Cunningham, James L.; Miles, Anthony W.


    The monitoring of fracture healing still relies upon the judgment of callus formation and on the manual assessment of the stiffness of the fracture. A diagnostic tool capable of quantitatively measuring healing progression of a fracture would allow the fine-tuning of the treatment regime. Ultrasound attenuation measurements were adopted as a possible method of assessing the healing process in human long bones. The method involves exciting ultrasonic waves at 200 kHz in the bone and measuring the reradiation along the bone and across the fracture zone. Seven cadaveric femora were tested in vitro in intact form and after creating a transverse fracture by sawing through the cortex. The effects of five different fracture types were investigated. A partial fracture, corresponding to a 50% cut through the cortex, a closed fracture, and fractures of widths varying between 1, 2, and 4 mm were investigated. The introduction of a fracture was found to produce a dramatic effect on the amplitude of the signal. Ultrasound attenuation was found to be sensitive to the presence of a fracture, even when the fracture was well reduced. It would therefore appear feasible to adopt attenuation across a fracture as a quantitative measurement of fracture healing.

  15. Quantitative Proteomic Analysis Provides Novel Insights into Cold Stress Responses in Petunia Seedlings. (United States)

    Zhang, Wei; Zhang, Huilin; Ning, Luyun; Li, Bei; Bao, Manzhu


    Low temperature is a major adverse environmental factor that impairs petunia growth and development. To better understand the molecular mechanisms of cold stress adaptation of petunia plants, a quantitative proteomic analysis using iTRAQ technology was performed to detect the effects of cold stress on protein expression profiles in petunia seedlings which had been subjected to 2°C for 5 days. Of the 2430 proteins whose levels were quantitated, a total of 117 proteins were discovered to be differentially expressed under low temperature stress in comparison to unstressed controls. As an initial study, 44 proteins including well known and novel cold-responsive proteins were successfully annotated. By integrating the results of two independent Gene Ontology (GO) enrichment analyses, seven common GO terms were found of which "oxidation-reduction process" was the most notable for the cold-responsive proteins. By using the subcellular localization tool Plant-mPLoc predictor, as much as 40.2% of the cold-responsive protein group was found to be located within chloroplasts, suggesting that the chloroplast proteome is particularly affected by cold stress. Gene expression analyses of 11 cold-responsive proteins by real time PCR demonstrated that the mRNA levels were not strongly correlated with the respective protein levels. Further activity assay of anti-oxidative enzymes showed different alterations in cold treated petunia seedlings. Our investigation has highlighted the role of antioxidation mechanisms and also epigenetic factors in the regulation of cold stress responses. Our work has provided novel insights into the plant response to cold stress and should facilitate further studies regarding the molecular mechanisms which determine how plant cells cope with environmental perturbation. The data have been deposited to the ProteomeXchange with identifier PXD002189.

  16. Providing Open-Access Know How for Directors of Quantitative and Mathematics Support Centers


    Michael Schuckers; Mary B. O'Neill; Grace Coulombe


    The purpose of this editorial is to introduce the quantitative literacy community to the newly published A Handbook for Directors of Quantitative and Mathematics Centers. QMaSCs (pronounced “Q-masks”) can be broadly defined as centers that have supporting students in quantitative fields of study as part of their mission. Some focus only on calculus or mathematics; others concentrate on numeracy or quantitative literacy, and some do all of that. A QMaSC may be embedded in a mathematics departm...

  17. Tophaceous gout: quantitative evaluation by direct physical measurement. (United States)

    Schumacher, H Ralph; Becker, Michael A; Palo, William A; Streit, Janet; MacDonald, Patricia A; Joseph-Ridge, Nancy


    The absence of accepted standardized methods for monitoring tophaceous gout limits the ability to track tophus progression or regression. This multicenter study assessed intra- and interrater reproducibility of a simple and direct physical measurement. The quantitative evaluation was the area (mm2) of each measurable tophus and was determined independently by 2 raters on 2 occasions within 10 days. Intra- and interrater reproducibilities were determined by calculating mean differences and average percentage differences (APD) in measurements of areas for the same tophus at each of 2 visits and by each rater, respectively. Fifty-two tophi were measured in 13 subjects: 22 on the hand/wrist, 16 on the elbow, and 14 on the foot/ankle. The mean (+/- SD) difference in tophus areas between visits was -0.2 +/- 835 mm2 (95% CI -162 to 162 mm2) and the mean (+/- SD) APD was 29% +/- 33%. The mean (+/- SD) APD between raters was 32% +/- 27%. The largest variations in measurements were noted for elbow tophi and variations were least for well demarcated tophi on the hands. This simple and reproducible method can be easily utilized in clinical trials and in practice as a measure of efficacy of urate-lowering treatment in tophaceous gout. Among factors contributing to variability in these measurements were the anatomic site of tophi and rater experience with the method. Restriction of measurements to well circumscribed hand or foot tophi could improve reliability, but major changes, as expected with effective therapy, can clearly be documented with this simple technique.

  18. Cleavage Entropy as Quantitative Measure of Protease Specificity (United States)

    Fuchs, Julian E.; von Grafenstein, Susanne; Huber, Roland G.; Margreiter, Michael A.; Spitzer, Gudrun M.; Wallnoefer, Hannes G.; Liedl, Klaus R.


    A purely information theory-guided approach to quantitatively characterize protease specificity is established. We calculate an entropy value for each protease subpocket based on sequences of cleaved substrates extracted from the MEROPS database. We compare our results with known subpocket specificity profiles for individual proteases and protease groups (e.g. serine proteases, metallo proteases) and reflect them quantitatively. Summation of subpocket-wise cleavage entropy contributions yields a measure for overall protease substrate specificity. This total cleavage entropy allows ranking of different proteases with respect to their specificity, separating unspecific digestive enzymes showing high total cleavage entropy from specific proteases involved in signaling cascades. The development of a quantitative cleavage entropy score allows an unbiased comparison of subpocket-wise and overall protease specificity. Thus, it enables assessment of relative importance of physicochemical and structural descriptors in protease recognition. We present an exemplary application of cleavage entropy in tracing substrate specificity in protease evolution. This highlights the wide range of substrate promiscuity within homologue proteases and hence the heavy impact of a limited number of mutations on individual substrate specificity. PMID:23637583

  19. Cleavage entropy as quantitative measure of protease specificity.

    Directory of Open Access Journals (Sweden)

    Julian E Fuchs


    Full Text Available A purely information theory-guided approach to quantitatively characterize protease specificity is established. We calculate an entropy value for each protease subpocket based on sequences of cleaved substrates extracted from the MEROPS database. We compare our results with known subpocket specificity profiles for individual proteases and protease groups (e.g. serine proteases, metallo proteases and reflect them quantitatively. Summation of subpocket-wise cleavage entropy contributions yields a measure for overall protease substrate specificity. This total cleavage entropy allows ranking of different proteases with respect to their specificity, separating unspecific digestive enzymes showing high total cleavage entropy from specific proteases involved in signaling cascades. The development of a quantitative cleavage entropy score allows an unbiased comparison of subpocket-wise and overall protease specificity. Thus, it enables assessment of relative importance of physicochemical and structural descriptors in protease recognition. We present an exemplary application of cleavage entropy in tracing substrate specificity in protease evolution. This highlights the wide range of substrate promiscuity within homologue proteases and hence the heavy impact of a limited number of mutations on individual substrate specificity.

  20. Impact of image quality on OCT angiography based quantitative measurements. (United States)

    Al-Sheikh, Mayss; Ghasemi Falavarjani, Khalil; Akil, Handan; Sadda, SriniVas R


    To study the impact of image quality on quantitative measurements and the frequency of segmentation error with optical coherence tomography angiography (OCTA). Seventeen eyes of 10 healthy individuals were included in this study. OCTA was performed using a swept-source device (Triton, Topcon). Each subject underwent three scanning sessions 1-2 min apart; the first two scans were obtained under standard conditions and for the third session, the image quality index was reduced using application of a topical ointment. En face OCTA images of the retinal vasculature were generated using the default segmentation for the superficial and deep retinal layer (SRL, DRL). Intraclass correlation coefficient (ICC) was used as a measure for repeatability. The frequency of segmentation error, motion artifact, banding artifact and projection artifact was also compared among the three sessions. The frequency of segmentation error, and motion artifact was statistically similar between high and low image quality sessions (P = 0.707, and P = 1 respectively). However, the frequency of projection and banding artifact was higher with a lower image quality. The vessel density in the SRL was highly repeatable in the high image quality sessions (ICC = 0.8), however, the repeatability was low, comparing the high and low image quality measurements (ICC = 0.3). In the DRL, the repeatability of the vessel density measurements was fair in the high quality sessions (ICC = 0.6 and ICC = 0.5, with and without automatic artifact removal, respectively) and poor comparing high and low image quality sessions (ICC = 0.3 and ICC = 0.06, with and without automatic artifact removal, respectively). The frequency of artifacts is higher and the repeatability of the measurements is lower with lower image quality. The impact of image quality index should be always considered in OCTA based quantitative measurements.

  1. Comparison of quantitative flow cytometric data provided by panels with lower and increased color number (United States)

    Bocsi, József; Mittag, Anja; Pierzchalski, Arkadiusz; Baumgartner, Adolf; Dähnert, Ingo; Tárnok, Attila


    To date the flow cytometry (FCM) industry is booming with new generations of commercial clinical instruments. Long-term clinical studies have the dilemma that moving to new instruments being capable of more complex cell-analysis makes it difficult to compare new data with those obtained on older instruments with less complex analysis panels. Since 15 years we conduct follow-up studies on children with congenital heart diseases. In this period we moved from 2- to 3- and now to 10-color FCM immunophenotyping panels. Questions arise how to compare and transfer data from lower to higher level of complexity. Two comparable antibody panels for leukocyte immunophenotyping (12-tube 2-colors, and 9-tube 4-colors) were measured on a BD FACScalibur FCM (calibration: Spherotech beads) in 19 blood samples from children with congenital heart disease. This increase of colors was accompanied by moving antibodies that were in the 2-color panel either FITC or PE labeled to red dyes such as PerCP or APC. Algorithms were developed for bridging data for quantitative characterization of antigen expression (mean fluorescence intensity) and frequency of different cell subpopulations in combination with rainbow bead standard data. This approach worked for the most relevant antibodies (CD3, CD4, CD8 etc.) well, but rendered substantial uncertainty for activation markers (CD69 etc.). Our techniques are particularly well suited to the analysis in long-term studies and have the potential to compare older and recent results in a standardized way.

  2. Quantitative evaluation of fiber fuse initiation with exposure to arc discharge provided by a fusion splicer. (United States)

    Todoroki, Shin-Ichi


    The optical communication industry and power-over-fiber applications face a dilemma as a result of the expanding demand of light power delivery and the potential risks of high-power light manipulation including the fiber fuse phenomenon, a continuous destruction of the fiber core pumped by the propagating light and triggered by a heat-induced strong absorption of silica glass. However, we have limited knowledge on its initiation process in the viewpoint of energy flow in the reactive area. Therefore, the conditions required for a fiber fuse initiation in standard single-mode fibers were determined quantitatively, namely the power of a 1480 nm fiber laser and the arc discharge intensity provided by a fusion splicer for one second as an outer heat source. Systematic investigation on the energy flow balance between these energy sources revealed that the initiation process consists of two steps; the generation of a precursor at the heated spot and the transition to a stable fiber fuse. The latter step needs a certain degree of heat accumulation at the core where waveguide deformation is ongoing competitively. This method is useful for comparing the tolerance to fiber fuse initiation among various fibers with a fixed energy amount that was not noticed before.

  3. Quantitativeness of phase measurement by transport of intensity equation. (United States)

    Mitome, Masanori; Ishizuka, Kazuo; Bando, Yoshio


    Based on the transport of intensity equation (TIE), a phase map can be readily retrieved from only three images of a focal series. The retrieval procedure does not require an iterative calculation and it is performed very fast with the use of the fast Fourier transform. However, it must be noted that sensitivity depends on the spatial frequency components and difficulties are encountered when phase information is retrieved to be of the same quality for all frequency components. Since the retrieved phase is influenced by conditions in which the focal series was taken, it is important to select the appropriate conditions and parameters used in this process. Optimal conditions to preserve the quantitativeness of phase maps measured by the TIE method are discussed theoretically and they are demonstrated by measuring phase shifts in silver particles. It was found that the high quantitativeness can be obtained by selecting appropriately a defocus difference and a high pass filter constant according to the frequency components for the objects.

  4. Are quantitative functional measures more sensitive to worsening MS than traditional measures? (United States)

    Schwid, S R; Goodman, A D; Apatoff, B R; Coyle, P K; Jacobs, L D; Krupp, L B; Miller, A E; Wende, K E; Brownscheidle, C M; New York State Multiple Sclero


    The authors used data collected prospectively during a multicenter trial in 133 patients with secondary progressive MS to assess the relative sensitivity of quantitative functional tests and traditional measures, including the Expanded Disability Status Scale (EDSS) and Ambulation Index. Quantitative functional measures worsened in 69% of patients during an average of 6 months of observation, whereas the Clinical Global Impression of Change worsened in 33% and the EDSS worsened in 25% of patients. These changes should be interpreted in the context of the test-retest reliability for each measure.

  5. Providing Quantitative Information and a Nudge to Undergo Stool Testing in a Colorectal Cancer Screening Decision Aid: A Randomized Clinical Trial. (United States)

    Schwartz, Peter H; Perkins, Susan M; Schmidt, Karen K; Muriello, Paul F; Althouse, Sandra; Rawl, Susan M


    Guidelines recommend that patient decision aids should provide quantitative information about probabilities of potential outcomes, but the impact of this information is unknown. Behavioral economics suggests that patients confused by quantitative information could benefit from a "nudge" towards one option. We conducted a pilot randomized trial to estimate the effect sizes of presenting quantitative information and a nudge. Primary care patients (n = 213) eligible for colorectal cancer screening viewed basic screening information and were randomized to view (a) quantitative information (quantitative module), (b) a nudge towards stool testing with the fecal immunochemical test (FIT) (nudge module), (c) neither a nor b, or (d) both a and b. Outcome measures were perceived colorectal cancer risk, screening intent, preferred test, and decision conflict, measured before and after viewing the decision aid, and screening behavior at 6 months. Patients viewing the quantitative module were more likely to be screened than those who did not ( P = 0.012). Patients viewing the nudge module had a greater increase in perceived colorectal cancer risk than those who did not ( P = 0.041). Those viewing the quantitative module had a smaller increase in perceived risk than those who did not ( P = 0.046), and the effect was moderated by numeracy. Among patients with high numeracy who did not view the nudge module, those who viewed the quantitative module had a greater increase in intent to undergo FIT ( P = 0.028) than did those who did not. The limitations of this study were the limited sample size and single healthcare system. Adding quantitative information to a decision aid increased uptake of colorectal cancer screening, while adding a nudge to undergo FIT did not increase uptake. Further research on quantitative information in decision aids is warranted.

  6. A passive quantitative measurement of airway resistance using depth data. (United States)

    Ostadabbas, Sarah; Bulach, Christoph; Ku, David N; Anderson, Larry J; Ghovanloo, Maysam


    The Respiratory Syncytial Virus (RSV) is the most common cause of serious lower respiratory tract infections in infants and young children. RSV often causes increased airway resistance, clinically detected as wheezing by chest auscultation. In this disease, expiratory flows are significantly reduced due to the high resistance in patient's airway passages. A quantitative method for measuring resistance can have a great benefit to diagnosis and management of children with RSV infections as well as with other lung diseases. Airway resistance is defined as the lung pressure divided by the airflow. In this paper, we propose a method to quantify resistance through a simple, non-contact measurement of chest volume that can act as a surrogate measure of the lung pressure and volumetric airflow. We used depth data collected by a Microsoft Kinect camera for the measurement of the lung volume over time. In our experimentation, breathing through a number of plastic straws induced different airway resistances. For a standard spirometry test, our volume/flow estimation using Kinect showed strong correlation with the flow data collected by a commercially-available spirometer (five subjects, each performing 20 breathing trials, correlation coefficient = 0.88, with 95% confidence interval). As the number of straws decreased, emulating a higher airway obstruction, our algorithm was sufficient to distinguish between several levels of airway resistance.

  7. Developing quantitative tools for measuring aspects of prisonization

    DEFF Research Database (Denmark)

    Kjær Minke, Linda


    The article describes and discusses the preparation and completion of a quantitative study among prison officers and prisoners.......The article describes and discusses the preparation and completion of a quantitative study among prison officers and prisoners....

  8. Quantitative comparison of measurements of urgent care service quality. (United States)

    Qin, Hong; Prybutok, Victor; Prybutok, Gayle


    Service quality and patient satisfaction are essential to health care organization success. Parasuraman, Zeithaml, and Berry introduced SERVQUAL, a prominent service quality measure not yet applied to urgent care. We develop an instrument to measure perceived service quality and identify the determinants of patient satisfaction/ behavioral intentions. We examine the relationships among perceived service quality, patient satisfaction and behavioral intentions, and demonstrate that urgent care service quality is not equivalent using measures of perceptions only, differences of expectations minus perceptions, ratio of perceptions to expectations, and the log of the ratio. Perceptions provide the best measure of urgent care service quality.

  9. Phase measurements of erythrocytes affected by metal ions with quantitative interferometric microscopy (United States)

    Wang, Shouyu; Yan, Keding; Shan, Yanke; Xu, Mingfei; Liu, Fei; Xue, Liang


    Erythrocyte morphology is an important factor in disease diagnosis, however, traditional setups as microscopes and cytometers cannot provide enough quantitative information of cellular morphology for in-depth statistics and analysis. In order to capture variations of erythrocytes affected by metal ions, quantitative interferometric microscopy (QIM) is applied to monitor their morphology changes. Combined with phase retrieval and cell recognition, erythrocyte phase images, as well as phase area and volume, can be accurately and automatically obtained. The research proves that QIM is an effective tool in cellular observation and measurement.

  10. Short ECG segments predict defibrillation outcome using quantitative waveform measures. (United States)

    Coult, Jason; Sherman, Lawrence; Kwok, Heemun; Blackwood, Jennifer; Kudenchuk, Peter J; Rea, Thomas D


    Quantitative waveform measures of the ventricular fibrillation (VF) electrocardiogram (ECG) predict defibrillation outcome. Calculation requires an ECG epoch without chest compression artifact. However, pauses in CPR can adversely affect survival. Thus the potential use of waveform measures is limited by the need to pause CPR. We sought to characterize the relationship between the length of the CPR-free epoch and the ability to predict outcome. We conducted a retrospective investigation using the CPR-free ECG prior to first shock among out-of-hospital VF cardiac arrest patients in a large metropolitan region (n=442). Amplitude Spectrum Area (AMSA) and Median Slope (MS) were calculated using ECG epochs ranging from 5s to 0.2s. The relative ability of the measures to predict return of organized rhythm (ROR) and neurologically-intact survival was evaluated at different epoch lengths by calculating the area under the receiver operating characteristic curve (AUC) using the 5-s epoch as the referent group. Compared to the 5-s epoch, AMSA performance declined significantly only after reducing epoch length to 0.2s for ROR (AUC 0.77-0.74, p=0.03) and with epochs of ≤0.6s for neurologically-intact survival (AUC 0.72-0.70, p=0.04). MS performance declined significantly with epochs of ≤0.8s for ROR (AUC 0.78-0.77, p=0.04) and with epochs ≤1.6s for neurologically-intact survival (AUC 0.72-0.71, p=0.04). Waveform measures predict defibrillation outcome using very brief ECG epochs, a quality that may enable their use in current resuscitation algorithms designed to limit CPR interruption. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Measuring parental satisfaction of care quality provided in hospitalized children

    Directory of Open Access Journals (Sweden)

    Spyridoula Tsironi


    Full Text Available Introduction: Measuring parental satisfaction is of major importance for pediatric hospitals and the key component of evaluating the quality of services provided to health services. Aim: To assess the degree of parental satisfaction from the care provided to their hospitalized children.Methodology: A descriptive study conducted using a convenience sample of parents of hospitalized children in two public pediatric hospitals in Athens. Data collection was completed in a period of 3 months. 352 questionnaires were collected (response rate 88%. The Pyramid Questionnaire for parents of hospitalized children was used which estimates the degree of parental satisfaction from the care provided to their hospitalized child.Results: More parents were satisfied with health care professionals’ behavior (81,9%, the supplied care (78,2% and the information provision to parents regarding the hospitalized child’s disease (71,9%. In contrast, less parents were satisfied with their hospitalized child’s involvement in care (52,3% and the accessibility to the hospital (39,5%. The overall parental satisfaction ranged in very good level (76,8% and it was higher on hospital A (78,8%, among married parents (77,4% and those not al all concerned or concerned less for child’s illness (83,1%. Logistic regression model showed that hospitalization in hospital B and the great concern for child’s illness and its complications decreased ovewrall satisfaction by 24% and 17% respectively. Conclusions: The assessment of the degree of parental satisfaction is the most important indicator of hospitals’ proper functioning. From our study certain areas need improvement, such as: the parental involvement in child’s care, information provision, the accessibility to the hospital, the communication and the interpersonal health care in order greater satisfaction to be achieved.

  12. A Systematic Review of Quantitative Resilience Measures for Water Infrastructure Systems

    Directory of Open Access Journals (Sweden)

    Sangmin Shin


    Full Text Available Over the past few decades, the concept of resilience has emerged as an important consideration in the planning and management of water infrastructure systems. Accordingly, various resilience measures have been developed for the quantitative evaluation and decision-making of systems. There are, however, numerous considerations and no clear choice of which measure, if any, provides the most appropriate representation of resilience for a given application. This study provides a critical review of quantitative approaches to measure the resilience of water infrastructure systems, with a focus on water resources and distribution systems. A compilation of 11 criteria evaluating 21 selected resilience measures addressing major features of resilience is developed using the Axiomatic Design process. Existing gaps of resilience measures are identified based on the review criteria. The results show that resilience measures have generally paid less attention to cascading damage to interrelated systems, rapid identification of failure, physical damage of system components, and time variation of resilience. Concluding the paper, improvements to resilience measures are recommended. The findings contribute to our understanding of gaps and provide information to help further improve resilience measures of water infrastructure systems.

  13. Quantitative flow and velocity measurements of pulsatile blood flow with 4D-DSA (United States)

    Shaughnessy, Gabe; Hoffman, Carson; Schafer, Sebastian; Mistretta, Charles A.; Strother, Charles M.


    Time resolved 3D angiographic data from 4D DSA provides a unique environment to explore physical properties of blood flow. Utilizing the pulsatility of the contrast waveform, the Fourier components can be used to track the waveform motion through vessels. Areas of strong pulsatility are determined through the FFT power spectrum. Using this method, we find an accuracy from 4D-DSA flow measurements within 7.6% and 6.8% RMSE of ICA PCVIPR and phantom flow probe validation measurements, respectively. The availability of velocity and flow information with fast acquisition could provide a more quantitative approach to treatment planning and evaluation in interventional radiology.

  14. Influence of Inflammatory Polyarthritis on Quantitative Heel Ultrasound Measurements

    Directory of Open Access Journals (Sweden)

    Pye Stephen R


    Full Text Available Abstract Background There are few data concerning the impact of inflammatory polyarthritis (IP on quantitative heel ultrasound (QUS measurements. The aims of this analysis were i to determine the influence of IP on QUS measurements at the heel and, ii among those with IP to determine the influence of disease related factors on these measurements. Methods Men and women aged 16 years and over with recent onset IP were recruited to the Norfolk Arthritis Register (NOAR. Individuals with an onset of joint symptoms between 1989 and 1999 were included in this analysis. At the baseline visit subjects underwent a standardised interview and clinical examination with blood taken for rheumatoid factor. A population-based prospective study of chronic disease (EPIC-Norfolk independently recruited men and women aged 40 to 79 years from the same geographic area between 1993 and 1997. At a follow up assessment between 1998 and 2000 subjects in EPIC-Norfolk were invited to have quantitative ultrasound measurements of the heel (CUBA-Clinical performed. We compared speed of sound (SOS and broadband ultrasound attenuation (BUA, in those subjects recruited to NOAR who had ultrasound measurements performed (as part of EPIC-Norfolk subsequent to the onset of joint symptoms with a group of age and sex matched non-IP controls who had participated in EPIC-Norfolk. Fixed effect linear regression was used to explore the influence of IP on the heel ultrasound parameters (SOS and BUA so the association could be quantified as the mean difference in BUA and SOS between cases and controls. In those with IP, linear regression was used to examine the association between these parameters and disease related factors. Results 139 men and women with IP and 278 controls (mean age 63.2 years were studied. Among those with IP, mean BUA was 76.3 dB/MHz and SOS 1621.8 m/s. SOS was lower among those with IP than the controls (difference = −10.0; 95% confidence interval (CI

  15. Providing effective trauma care: the potential for service provider views to enhance the quality of care (qualitative study nested within a multicentre longitudinal quantitative study). (United States)

    Beckett, Kate; Earthy, Sarah; Sleney, Jude; Barnes, Jo; Kellezi, Blerina; Barker, Marcus; Clarkson, Julie; Coffey, Frank; Elder, Georgina; Kendrick, Denise


    To explore views of service providers caring for injured people on: the extent to which services meet patients' needs and their perspectives on factors contributing to any identified gaps in service provision. Qualitative study nested within a quantitative multicentre longitudinal study assessing longer term impact of unintentional injuries in working age adults. Sampling frame for service providers was based on patient-reported service use in the quantitative study, patient interviews and advice of previously injured lay research advisers. Service providers' views were elicited through semistructured interviews. Data were analysed using thematic analysis. Participants were recruited from a range of settings and services in acute hospital trusts in four study centres (Bristol, Leicester, Nottingham and Surrey) and surrounding areas. 40 service providers from a range of disciplines. Service providers described two distinct models of trauma care: an 'ideal' model, informed by professional knowledge of the impact of injury and awareness of best models of care, and a 'real' model based on the realities of National Health Service (NHS) practice. Participants' 'ideal' model was consistent with standards of high-quality effective trauma care and while there were examples of services meeting the ideal model, 'real' care could also be fragmented and inequitable with major gaps in provision. Service provider accounts provide evidence of comprehensive understanding of patients' needs, awareness of best practice, compassion and research but reveal significant organisational and resource barriers limiting implementation of knowledge in practice. Service providers envisage an 'ideal' model of trauma care which is timely, equitable, effective and holistic, but this can differ from the care currently provided. Their experiences provide many suggestions for service improvements to bridge the gap between 'real' and 'ideal' care. Using service provider views to inform service design

  16. Measuring Efficiency of Secondary Healthcare Providers in Slovenia (United States)

    Blatnik, Patricia; Bojnec, Štefan; Tušak, Matej


    Abstract The chief aim of this study was to analyze secondary healthcare providers' efficiency, focusing on the efficiency analysis of Slovene general hospitals. We intended to present a complete picture of technical, allocative, and cost or economic efficiency of general hospitals. Methods We researched the aspects of efficiency with two econometric methods. First, we calculated the necessary quotients of efficiency with the stochastic frontier analyze (SFA), which are realized by econometric evaluation of stochastic frontier functions; then, with the data envelopment analyze (DEA), we calculated the necessary quotients that are based on the linear programming method. Results Results on measures of efficiency showed that the two chosen methods produced two different conclusions. The SFA method concluded Celje General Hospital is the most efficient general hospital, whereas the DEA method concluded Brežice General Hospital was the hospital to be declared as the most efficient hospital. Conclusion Our results are a useful tool that can aid managers, payers, and designers of healthcare policy to better understand how general hospitals operate. The participants can accordingly decide with less difficulty on any further business operations of general hospitals, having the best practices of general hospitals at their disposal. PMID:28730180

  17. Quantitative Laughter Detection, Measurement, and Classification-A Critical Survey. (United States)

    Cosentino, Sarah; Sessa, Salvatore; Takanishi, Atsuo


    The study of human nonverbal social behaviors has taken a more quantitative and computational approach in recent years due to the development of smart interfaces and virtual agents or robots able to interact socially. One of the most interesting nonverbal social behaviors, producing a characteristic vocal signal, is laughing. Laughter is produced in several different situations: in response to external physical, cognitive, or emotional stimuli; to negotiate social interactions; and also, pathologically, as a consequence of neural damage. For this reason, laughter has attracted researchers from many disciplines. A consequence of this multidisciplinarity is the absence of a holistic vision of this complex behavior: the methods of analysis and classification of laughter, as well as the terminology used, are heterogeneous; the findings sometimes contradictory and poorly documented. This survey aims at collecting and presenting objective measurement methods and results from a variety of different studies in different fields, to contribute to build a unified model and taxonomy of laughter. This could be successfully used for advances in several fields, from artificial intelligence and human-robot interaction to medicine and psychiatry.

  18. Quantitative analysis of impact measurements using dynamic load cells

    Directory of Open Access Journals (Sweden)

    Brent J. Maranzano


    Full Text Available A mathematical model is used to estimate material properties from a short duration transient impact force measured by dropping spheres onto rectangular coupons fixed to a dynamic load cell. The contact stress between the dynamic load cell surface and the projectile are modeled using Hertzian contact mechanics. Due to the short impact time relative to the load cell dynamics, an additional Kelvin–Voigt element is included in the model to account for the finite response time of the piezoelectric crystal. Calculations with and without the Kelvin–Voigt element are compared to experimental data collected from combinations of polymeric spheres and polymeric and metallic surfaces. The results illustrate that the inclusion of the Kelvin–Voigt element qualitatively captures the post impact resonance and non-linear behavior of the load cell signal and quantitatively improves the estimation of the Young's elastic modulus and Poisson's ratio. Mathematically, the additional KV element couples one additional differential equation to the Hertzian spring-dashpot equation. The model can be numerically integrated in seconds using standard numerical techniques allowing for its use as a rapid technique for the estimation of material properties.

  19. Longitudinal change in quantitative meniscus measurements in knee osteoarthritis - data from the Osteoarthritis Initiative

    Energy Technology Data Exchange (ETDEWEB)

    Bloecker, Katja [Paracelsus Medical University Salzburg and Nuremberg (Austria); Salzburg, Institute of Anatomy, Salzburg (Austria); BHS Linz, Department of Orthopaedics, Linz (Austria); Wirth, W.; Eckstein, F. [Paracelsus Medical University Salzburg and Nuremberg (Austria); Salzburg, Institute of Anatomy, Salzburg (Austria); Chondrometrics GmbH, Ainring (Germany); Guermazi, A. [Boston University School of Medicine, Boston, MA (United States); Boston Imaging Core Lab (BICL), Boston, MA (United States); Hitzl, W. [Paracelsus Medical University Salzburg and Nuremberg, Research Office, Salzburg (Austria); Hunter, D.J. [University of Sydney, Royal North Shore Hospital and Institute of Bone and Joint Research, Kolling Institute, Sydney (Australia)


    We aimed to apply 3D MRI-based measurement technology to studying 2-year change in quantitative measurements of meniscus size and position. Forty-seven knees from the Osteoarthritis Initiative with medial radiographic joint space narrowing had baseline and 2-year follow-up MRIs. Quantitative measures were obtained from manual segmentation of the menisci and tibia using coronal DESSwe images. The standardized response mean (SRM = mean/SD change) was used as measure of sensitivity to longitudinal change. Medial tibial plateau coverage decreased from 34.8 % to 29.9 % (SRM -0.82; p < 0.001). Change in medial meniscus extrusion in a central image (SRM 0.18) and in the central five slices (SRM 0.22) did not reach significance, but change in extrusion across the entire meniscus (SRM 0.32; p = 0.03) and in the relative area of meniscus extrusion (SRM 0.56; p < 0.001) did. There was a reduction in medial meniscus volume (10 %; p < 0.001), width (7 %; p < 0.001), and height (2 %; p = 0.08); meniscus substance loss was strongest in the posterior (SRM -0.51; p = 0.001) and weakest in the anterior horn (SRM -0.15; p = 0.31). This pilot study reports, for the first time, longitudinal change in quantitative 3D meniscus measurements in knee osteoarthritis. It provides evidence of improved sensitivity to change of 3D measurements compared with single slice analysis. (orig.)

  20. Quantitative electroencephalographic measures in homicidal men with antisocial personality disorder. (United States)

    Lindberg, Nina; Tani, Pekka; Virkkunen, Matti; Porkka-Heiskanen, Tarja; Appelberg, Björn; Naukkarinen, Hannu; Salmi, Tapani


    Many symptoms of antisocial personality disorder have been proposed to be related to decreased daytime vigilance. To explore this hypothesis, quantitative analyses were conducted of the electroencephalographic (EEG) activity of drug-free and detoxified homicidal male offenders with antisocial personality disorder as the primary diagnosis. Subjects comprised 16 men recruited from a forensic psychiatric examination in a special ward of a university psychiatric hospital. Fifteen healthy age- and gender-matched controls with no criminal record or history of physical violence consisted of hospital staff and students. An overall reduction of alpha power was observed in the waking EEG of offenders. A bilateral increase in occipital delta and theta power was also found in these individuals. This study provides further support to the growing evidence of brain dysfunction in severe aggressive behavior. Homicidal offenders with antisocial personality disorder seem to have difficulties in maintaining normal daytime arousal. Decreased vigilance, together with social and psychological variables, may explain their aberrant behavior in everyday life. New studies are, however, needed to specify the vigilance problems of this patient group.

  1. A Framework for Mixing Methods in Quantitative Measurement Development, Validation, and Revision: A Case Study (United States)

    Luyt, Russell


    A framework for quantitative measurement development, validation, and revision that incorporates both qualitative and quantitative methods is introduced. It extends and adapts Adcock and Collier's work, and thus, facilitates understanding of quantitative measurement development, validation, and revision as an integrated and cyclical set of…

  2. Quantitative Chemical Measurements of Vesicular Transmitters with Electrochemical Cytometry. (United States)

    Li, Xianchan; Dunevall, Johan; Ewing, Andrew G


    Electrochemical cytometry adds a new dimension to our ability to study the chemistry and chemical storage of transmitter molecules stored in nanometer vesicles. The approach involves the adsorption and subsequent rupture of vesicles on an electrode surface during which the electroactive contents are quantitatively oxidized (or reduced). The measured current allows us to count the number of molecules in the vesicles using Faraday's law and to correlate this to the amount of molecules released when single exocytosis events take place at communicating cells. The original format for this method involved a capillary electrophoresis separation step to singly address each vesicle, but we have more recently discovered that cellular vesicles tend to adsorb to carbon electrodes and spontaneously as well as stochastically rupture to give mostly single vesicle events. This approach, called impact electrochemical cytometry, even though the impact is perhaps not the important part of this process, has been studied and the vesicle rupture appears to be at the interface between the vesicle and the electrode and is probably driven by electroporation. The pore size and rate of content electrolysis are a function of the pore diameter and the presence of a protein core in the vesicles. In model liposomes with no protein, events appear extremely rapidly as the soft nanoparticles impact the electrode and the contents are oxidized. It appears that the proteins decorating the surface of the vesicle are important in maintaining a gap from the electrode and when this gap is closed electroporation takes place. Models of the event response times suggest the pores formed are small enough so we can carry out these measurements at nanotip electrodes and we have used this to quantify the vesicle content in living cells in a mode we call intracellular impact electrochemical cytometry. The development of electrochemical cytometry allows comparison between vesicle content and vesicular release and

  3. Evaluating Frameworks That Provide Value Measures for Health Care Interventions. (United States)

    Mandelblatt, Jeanne S; Ramsey, Scott D; Lieu, Tracy A; Phelps, Charles E


    The recent acceleration of scientific discovery has led to greater choices in health care. New technologies, diagnostic tests, and pharmaceuticals have widely varying impact on patients and populations in terms of benefits, toxicities, and costs, stimulating a resurgence of interest in the creation of frameworks intended to measure value in health. Many of these are offered by providers and/or advocacy organizations with expertise and interest in specific diseases (e.g., cancer and heart disease). To help assess the utility of and the potential biases embedded in these frameworks, we created an evaluation taxonomy with seven basic components: 1) define the purpose; 2) detail the conceptual approach, including perspectives, methods for obtaining preferences of decision makers (e.g., patients), and ability to incorporate multiple dimensions of value; 3) discuss inclusions and exclusions of elements included in the framework, and whether the framework assumes clinical intervention or offers alternatives such as palliative care or watchful waiting; 4) evaluate data sources and their scientific validity; 5) assess the intervention's effect on total costs of treating a defined population; 6) analyze how uncertainty is incorporated; and 7) illuminate possible conflicts of interest among those creating the framework. We apply the taxonomy to four representative value frameworks recently published by professional organizations focused on treatment of cancer and heart disease and on vaccine use. We conclude that each of these efforts has strengths and weaknesses when evaluated using our taxonomy, and suggest pathways to enhance the utility of value-assessing frameworks for policy and clinical decision making. Copyright © 2017 International Society for Pharmacoeconomics and Outcomes Research (ISPOR). Published by Elsevier Inc. All rights reserved.

  4. Quantitative measurement of metal chelation by fourier transform infrared spectroscopy

    Directory of Open Access Journals (Sweden)

    Monika E. Miller


    Full Text Available Nutritionally important minerals are more readily absorbed by living systems when complexed with organic acids, resulting in higher consumer demand and premium prices for these products. These chelated metals are produced by reaction of metal oxides and acids in aqueous solution. However, unreacted dry blends are sometimes misrepresented as metal chelates, when in reality they are only simple mixtures of the reactants typically used to synthesize them. This practice has increased interest in developing analytical methods that are capable of measuring the extent of metal chelation for quality control and regulatory compliance. We describe a novel method to rapidly measure the percent chelation of citric and malic acids with calcium, magnesium, and zinc. Utilization of attenuated total reflectance (FTIR-ATR provides for the direct, rapid measurement of solid samples. The inclusion of an internal standard allows independent determination of either free or chelated acids from integrated areas in a single spectrum.

  5. Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography

    NARCIS (Netherlands)

    Bleeker, Leslie; Marquering, Henk A.; van den Berg, René; Nederkoorn, Paul J.; Majoie, Charles B.


    Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure

  6. Can Formal Methods Provide (Necessary and) Sufficient Conditions for Measurement? (United States)

    Mari, Luca


    In his focus article, "Rethinking Traditional Methods of Survey Validation," published in this issue of "Measurement: Interdisciplinary Research and Perspectives," Andrew Maul introduces and discusses several foundational issues and concludes that self-report measures may be particularly difficult to validate and may fall short…

  7. The importance of quantitative measurement methods for uveitis: laser flare photometry endorsed in Europe while neglected in Japan where the technology measuring quantitatively intraocular inflammation was developed. (United States)

    Herbort, Carl P; Tugal-Tutkun, Ilknur


    Laser flare photometry (LFP) is an objective and quantitative method to measure intraocular inflammation. The LFP technology was developed in Japan and has been commercially available since 1990. The aim of this work was to review the application of LFP in uveitis practice in Europe compared to Japan where the technology was born. We reviewed PubMed articles published on LFP and uveitis. Although LFP has been largely integrated in routine uveitis practice in Europe, it has been comparatively neglected in Japan and still has not received FDA approval in the USA. As LFP is the only method that provides a precise measure of intraocular inflammation, it should be used as a gold standard in uveitis centres worldwide.

  8. Quantitative evaluation of statistical errors in small-angle X-ray scattering measurements. (United States)

    Sedlak, Steffen M; Bruetzel, Linda K; Lipfert, Jan


    A new model is proposed for the measurement errors incurred in typical small-angle X-ray scattering (SAXS) experiments, which takes into account the setup geometry and physics of the measurement process. The model accurately captures the experimentally determined errors from a large range of synchrotron and in-house anode-based measurements. Its most general formulation gives for the variance of the buffer-subtracted SAXS intensity σ2(q) = [I(q) + const.]/(kq), where I(q) is the scattering intensity as a function of the momentum transfer q; k and const. are fitting parameters that are characteristic of the experimental setup. The model gives a concrete procedure for calculating realistic measurement errors for simulated SAXS profiles. In addition, the results provide guidelines for optimizing SAXS measurements, which are in line with established procedures for SAXS experiments, and enable a quantitative evaluation of measurement errors.

  9. Overview of quantitative measurement methods. Equivalence, invariance, and differential item functioning in health applications. (United States)

    Teresi, Jeanne A


    Reviewed in this article are issues relating to the study of invariance and differential item functioning (DIF). The aim of factor analyses and DIF, in the context of invariance testing, is the examination of group differences in item response conditional on an estimate of disability. Discussed are parameters and statistics that are not invariant and cannot be compared validly in crosscultural studies with varying distributions of disability in contrast to those that can be compared (if the model assumptions are met) because they are produced by models such as linear and nonlinear regression. The purpose of this overview is to provide an integrated approach to the quantitative methods used in this special issue to examine measurement equivalence. The methods include classical test theory (CTT), factor analytic, and parametric and nonparametric approaches to DIF detection. Also included in the quantitative section is a discussion of item banking and computerized adaptive testing (CAT). Factorial invariance and the articles discussing this topic are introduced. A brief overview of the DIF methods presented in the quantitative section of the special issue is provided together with a discussion of ways in which DIF analyses and examination of invariance using factor models may be complementary. Although factor analytic and DIF detection methods share features, they provide unique information and can be viewed as complementary in informing about measurement equivalence.

  10. Effects of performance measure implementation on clinical manager and provider motivation. (United States)

    Damschroder, Laura J; Robinson, Claire H; Francis, Joseph; Bentley, Douglas R; Krein, Sarah L; Rosland, Ann-Marie; Hofer, Timothy P; Kerr, Eve A


    Clinical performance measurement has been a key element of efforts to transform the Veterans Health Administration (VHA). However, there are a number of signs that current performance measurement systems used within and outside the VHA may be reaching the point of maximum benefit to care and in some settings, may be resulting in negative consequences to care, including overtreatment and diminished attention to patient needs and preferences. Our research group has been involved in a long-standing partnership with the office responsible for clinical performance measurement in the VHA to understand and develop potential strategies to mitigate the unintended consequences of measurement. Our aim was to understand how the implementation of diabetes performance measures (PMs) influences management actions and day-to-day clinical practice. This is a mixed methods study design based on quantitative administrative data to select study facilities and quantitative data from semi-structured interviews. Sixty-two network-level and facility-level executives, managers, front-line providers and staff participated in the study. Qualitative content analyses were guided by a team-based consensus approach using verbatim interview transcripts. A published interpretive motivation theory framework is used to describe potential contributions of local implementation strategies to unintended consequences of PMs. Implementation strategies used by management affect providers' response to PMs, which in turn potentially undermines provision of high-quality patient-centered care. These include: 1) feedback reports to providers that are dissociated from a realistic capability to address performance gaps; 2) evaluative criteria set by managers that are at odds with patient-centered care; and 3) pressure created by managers' narrow focus on gaps in PMs that is viewed as more punitive than motivating. Next steps include working with VHA leaders to develop and test implementation approaches to help

  11. Measuring Perceptual (In) Congruence between Information Service Providers and Users (United States)

    Boyce, Crystal


    Library quality is no longer evaluated solely on the value of its collections, as user perceptions of service quality play an increasingly important role in defining overall library value. This paper presents a retooling of the LibQUAL+ survey instrument, blending the gap measurement model with perceptual congruence model studies from information…

  12. Quantitative measurement of mixtures by terahertz time-domain ...

    Indian Academy of Sciences (India)

    ... absorption coefficients of the components in each mixture were linearly proportional to their concentrations in the mixture. The results from analysis were in agreement with actual values with a relative error of less than 7%. The quantitative method will help in the detection of illegal drugs, poisons and dangerous materials ...

  13. Electrons, Photons, and Force: Quantitative Single-Molecule Measurements from Physics to Biology (United States)


    Single-molecule measurement techniques have illuminated unprecedented details of chemical behavior, including observations of the motion of a single molecule on a surface, and even the vibration of a single bond within a molecule. Such measurements are critical to our understanding of entities ranging from single atoms to the most complex protein assemblies. We provide an overview of the strikingly diverse classes of measurements that can be used to quantify single-molecule properties, including those of single macromolecules and single molecular assemblies, and discuss the quantitative insights they provide. Examples are drawn from across the single-molecule literature, ranging from ultrahigh vacuum scanning tunneling microscopy studies of adsorbate diffusion on surfaces to fluorescence studies of protein conformational changes in solution. PMID:21338175

  14. Electrons, photons, and force: quantitative single-molecule measurements from physics to biology. (United States)

    Claridge, Shelley A; Schwartz, Jeffrey J; Weiss, Paul S


    Single-molecule measurement techniques have illuminated unprecedented details of chemical behavior, including observations of the motion of a single molecule on a surface, and even the vibration of a single bond within a molecule. Such measurements are critical to our understanding of entities ranging from single atoms to the most complex protein assemblies. We provide an overview of the strikingly diverse classes of measurements that can be used to quantify single-molecule properties, including those of single macromolecules and single molecular assemblies, and discuss the quantitative insights they provide. Examples are drawn from across the single-molecule literature, ranging from ultrahigh vacuum scanning tunneling microscopy studies of adsorbate diffusion on surfaces to fluorescence studies of protein conformational changes in solution.

  15. Quantitative measurement of productivity loss due to thermal discomfort

    DEFF Research Database (Denmark)

    Lan, Li; Wargocki, Pawel; Lian, Zhiwei


    The effects on human performance of elevated temperature causing thermal discomfort were investigated. Recruited subjects performed neurobehavioural tests examining different component skills, and addition and typing tasks that were used to replicate office work. The results show that thermal...... discomfort caused by elevated air temperature had a negative effect on performance. A quantitative relationship was established between thermal sensation votes and task performance. It can be used for economic calculations pertaining to building design and operation when occupant productivity is considered...

  16. Quantitative method of measuring cancer cell urokinase and metastatic potential (United States)

    Morrison, Dennis R. (Inventor)


    The metastatic potential of tumors can be evaluated by the quantitative detection of urokinase and DNA. The cell sample selected for examination is analyzed for the presence of high levels of urokinase and abnormal DNA using analytical flow cytometry and digital image analysis. Other factors such as membrane associated urokinase, increased DNA synthesis rates and certain receptors can be used in the method for detection of potentially invasive tumors.

  17. The Fidelity Index provides a systematic quantitation of star activity of DNA restriction endonucleases. (United States)

    Wei, Hua; Therrien, Caitlin; Blanchard, Aine; Guan, Shengxi; Zhu, Zhenyu


    Restriction endonucleases are the basic tools of molecular biology. Many restriction endonucleases show relaxed sequence recognition, called star activity, as an inherent property under various digestion conditions including the optimal ones. To quantify this property we propose the concept of the Fidelity Index (FI), which is defined as the ratio of the maximum enzyme amount showing no star activity to the minimum amount needed for complete digestion at the cognate recognition site for any particular restriction endonuclease. Fidelity indices for a large number of restriction endonucleases are reported here. The effects of reaction vessel, reaction volume, incubation mode, substrate differences, reaction time, reaction temperature and additional glycerol, DMSO, ethanol and Mn(2+) on the FI are also investigated. The FI provides a practical guideline for the use of restriction endonucleases and defines a fundamental property by which restriction endonucleases can be characterized.

  18. Visual characterization and quantitative measurement of artemisinin-induced DNA breakage

    Energy Technology Data Exchange (ETDEWEB)

    Cai Huaihong [Bionanotechnology Lab, and Department of Chemistry, Jinan University, Guangzhou 510632 (China); Yang Peihui [Bionanotechnology Lab, and Department of Chemistry, Jinan University, Guangzhou 510632 (China)], E-mail:; Chen Jianan [Bionanotechnology Lab, and Department of Chemistry, Jinan University, Guangzhou 510632 (China); Liang Zhihong [Experiment and Technology Center, Jinan University, Guangzhou 510632 (China); Chen Qiongyu [Institute of Genetic Engineering, Jinan University, Guangzhou 510632 (China); Cai Jiye [Bionanotechnology Lab, and Department of Chemistry, Jinan University, Guangzhou 510632 (China)], E-mail:


    DNA conformational change and breakage induced by artemisinin, a traditional Chinese herbal medicine, have been visually characterized and quantitatively measured by the multiple tools of electrochemistry, UV-vis absorption spectroscopy, atomic force microscopy (AFM), and DNA electrophoresis. Electrochemical and spectroscopic results confirm that artemisinin can intercalate into DNA double helix, which causes DNA conformational changes. AFM imaging vividly demonstrates uneven DNA strand breaking induced by QHS interaction. To assess these DNA breakages, quantitative analysis of the extent of DNA breakage has been performed by analyzing AFM images. Basing on the statistical analysis, the occurrence of DNA breaks is found to depend on the concentration of artemisinin. DNA electrophoresis further validates that the intact DNA molecules are unwound due to the breakages occur at the single strands. A reliable scheme is proposed to explain the process of artemisinin-induced DNA cleavage. These results can provide further information for better understanding the anticancer activity of artemisinin.

  19. Measuring teamwork in primary care: Triangulation of qualitative and quantitative data. (United States)

    Brown, Judith Belle; Ryan, Bridget L; Thorpe, Cathy; Markle, Emma K R; Hutchison, Brian; Glazier, Richard H


    This article describes the triangulation of qualitative dimensions, reflecting high functioning teams, with the results of standardized teamwork measures. The study used a mixed methods design using qualitative and quantitative approaches to assess teamwork in 19 Family Health Teams in Ontario, Canada. This article describes dimensions from the qualitative phase using grounded theory to explore the issues and challenges to teamwork. Two quantitative measures were used in the study, the Team Climate Inventory (TCI) and the Providing Effective Resources and Knowledge (PERK) scale. For the triangulation analysis, the mean scores of these measures were compared with the qualitatively derived ratings for the dimensions. The final sample for the qualitative component was 107 participants. The qualitative analysis identified 9 dimensions related to high team functioning such as common philosophy, scope of practice, conflict resolution, change management, leadership, and team evolution. From these dimensions, teams were categorized numerically as high, moderate, or low functioning. Three hundred seventeen team members completed the survey measures. Mean site scores for the TCI and PERK were 3.87 and 3.88, respectively (of 5). The TCI was associated will all dimensions except for team location, space allocation, and executive director leadership. The PERK was associated with all dimensions except team location. Data triangulation provided qualitative and quantitative evidence of what constitutes teamwork. Leadership was pivotal in forging a common philosophy and encouraging team collaboration. Teams used conflict resolution strategies and adapted to the changes they encountered. These dimensions advanced the team's evolution toward a high functioning team. (c) 2015 APA, all rights reserved).

  20. Deconvolving Single-Molecule Intensity Distributions for Quantitative Microscopy Measurements (United States)

    Mutch, Sarah A.; Fujimoto, Bryant S.; Kuyper, Christopher L.; Kuo, Jason S.; Bajjalieh, Sandra M.; Chiu, Daniel T.


    In fluorescence microscopy, images often contain puncta in which the fluorescent molecules are spatially clustered. This article describes a method that uses single-molecule intensity distributions to deconvolve the number of fluorophores present in fluorescent puncta as a way to “count” protein number. This method requires a determination of the correct statistical relationship between the single-molecule and single-puncta intensity distributions. Once the correct relationship has been determined, basis histograms can be generated from the single-molecule intensity distribution to fit the puncta distribution. Simulated data were used to demonstrate procedures to determine this relationship, and to test the methodology. This method has the advantages of single-molecule measurements, providing both the mean and variation in molecules per puncta. This methodology has been tested with the avidin-biocytin binding system for which the best-fit distribution of biocytins in the sample puncta was in good agreement with a bulk determination of the avidin-biocytin binding ratio. PMID:17259276

  1. Practicable methods for histological section thickness measurement in quantitative stereological analyses (United States)

    Matenaers, Cyrill; Popper, Bastian; Rieger, Alexandra; Wanke, Rüdiger


    of SR to efficiently provide accurate section thickness measurements as a prerequisite for reliable estimates of dependent quantitative stereological parameters. PMID:29444158

  2. The perspective of healthcare providers and patients on health literacy: a systematic review of the quantitative and qualitative studies. (United States)

    Rajah, Retha; Ahmad Hassali, Mohamed Azmi; Jou, Lim Ching; Murugiah, Muthu Kumar


    Health literacy (HL) is a multifaceted concept, thus understanding the perspective of healthcare providers, patients, and the system is vital. This systematic review examines and synthesises the available studies on HL-related knowledge, attitude, practice, and perceived barriers. CINAHL and Medline (via EBSCOhost), Google Scholar, PubMed, ProQuest, Sage Journals, and Science Direct were searched. Both quantitative and/or qualitative studies in the English language were included. Intervention studies and studies focusing on HL assessment tools and prevalence of low HL were excluded. The risk of biasness reduced with the involvement of two reviewers independently assessing study eligibility and quality. A total of 30 studies were included, which consist of 19 quantitative, 9 qualitative, and 2 mixed-method studies. Out of 17 studies, 13 reported deficiency of HL-related knowledge among healthcare providers and 1 among patients. Three studies showed a positive attitude of healthcare providers towards learning about HL. Another three studies demonstrated patients feel shame exposing their literacy and undergoing HL assessment. Common HL communication techniques reported practiced by healthcare providers were the use of everyday language, teach-back method, and providing patients with reading materials and aids, while time constraint was the most reported HL perceived barriers by both healthcare providers and patients. Significant gaps exists in HL knowledge among healthcare providers and patients that needs immediate intervention. Such as, greater effort placed in creating a health system that provides an opportunity for healthcare providers to learn about HL and patients to access health information with taking consideration of their perceived barriers.

  3. Quantitative computed tomography measures of emphysema and airway wall thickness are related to respiratory symptoms

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Dirksen, Asger; Coxson, Harvey O


    There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness.......There is limited knowledge about the relationship between respiratory symptoms and quantitative high-resolution computed tomography measures of emphysema and airway wall thickness....

  4. Quantitative measurement of hip protector use and compliance. (United States)

    Evans, Katherine R; Lou, Edmond; Woloschuk, Chris; Hill, Doug; Li, Meng; Wong, Man-Sang


    Hip protectors are often prescribed to the elderly who are at risk of falling, with the goal of preventing hip fractures. However, determining the effectiveness of hip protectors has been hampered by unreliable compliance data. This study reports a reliable objective method of measuring compliance and the developed method could be used in any climate, regardless of temperature. Custom compliance monitors were built and embedded inside hip protectors. An algorithm was developed to utilize both temperature and acceleration to determine compliance. Seven young volunteers (age 24.6 ± 4.2 years old) wore the protectors for a total of 667 h while closely recording their compliance. One female (77 years old) who had hip fracture history wore the compliance monitors for 91.6 % of the time during a 1-week stay in a hospital. From the volunteers' trial, using temperature alone overpredicted compliance by 1.2 % and using acceleration alone overpredicted by 5.4 %, but using a combination of the two methods plus a correction factor only underestimated by 0.6 %. From the elderly data, the average compliance recorded from the temperature, acceleration, and combined methods with correction was 94.6, 88.9, and 90.2, respectively. The high accuracy of temperature sensors in this study will not be attainable in hot climates where most of the worldwide increase in hip fractures is occurring. The developed monitor with the algorithm provided high accuracy in determining compliance and was able to determine both the longitudinal and cross-sectional compliance at any time.

  5. Quantitative Measurement of Communication Ability in Children with Angelman Syndrome. (United States)

    Grieco, Joseph C; Bahr, Ruth H; Schoenberg, Mike R; Conover, Laura; Mackie, Lauren N; Weeber, Edwin J


    Angelman syndrome is a rare disorder in which most individuals do not develop speech. Testing of communication ability using traditional neuropsychological measures reveals a performance level at or near the floor of the instrument resulting in an inability to detect change when experimental therapeutics are applied. Nine individuals, with molecularly confirmed AS, ranging in age from 34 to 126 months, and a single healthy control child (age 16 months) were audio and video-recorded while interacting with a licensed speech-language pathologist in an attempt to elicit vocalization and non-verbal communication. Thirty-minute audio recordings were transcribed and categorized per the Stark Assessment of Early Vocal Development-Revised and a phonetic inventory was created. Using video recordings, gestures were classified by function, either behavioral regulation or social interaction and further categorized as deictic or representational (i.e., behavioral regulation) and joint attention or shared engagement (i.e., social interaction). The range of vocalizations produced by the children with AS was characteristic of children between 0-6 months and none of the children with AS used advanced forms of vocalizations. The mean frequency of reflexive vocalizations, control of phonation and expansion far exceeded the number of uses of canonical syllables, consistant with the characteristics of children around 12 months of age. Most vocalizations were either laughter or isolated vowels, only three children with AS produced consonant-vowel combinations. Children with AS tended to use central and low vowels with few producing high vowels, suggesting the presence of childhood apraxia of speech. Our results show the utilization of video-recorded behavioral observations provides a feasible and reliable alternative for quantification of communication ability in this patient population and may be employed during future clinical studies of potential therapeutics. © 2016 The Authors

  6. Semi-automatic quantitative measurements of intracranial internal carotid artery stenosis and calcification using CT angiography

    Energy Technology Data Exchange (ETDEWEB)

    Bleeker, Leslie; Berg, Rene van den; Majoie, Charles B. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Marquering, Henk A. [Academic Medical Center, Department of Radiology, Amsterdam (Netherlands); Academic Medical Center, Department of Biomedical Engineering and Physics, Amsterdam (Netherlands); Nederkoorn, Paul J. [Academic Medical Center, Department of Neurology, Amsterdam (Netherlands)


    Intracranial carotid artery atherosclerotic disease is an independent predictor for recurrent stroke. However, its quantitative assessment is not routinely performed in clinical practice. In this diagnostic study, we present and evaluate a novel semi-automatic application to quantitatively measure intracranial internal carotid artery (ICA) degree of stenosis and calcium volume in CT angiography (CTA) images. In this retrospective study involving CTA images of 88 consecutive patients, intracranial ICA stenosis was quantitatively measured by two independent observers. Stenoses were categorized with cutoff values of 30% and 50%. The calcification in the intracranial ICA was qualitatively categorized as absent, mild, moderate, or severe and quantitatively measured using the semi-automatic application. Linear weighted kappa values were calculated to assess the interobserver agreement of the stenosis and calcium categorization. The average and the standard deviation of the quantitative calcium volume were calculated for the calcium categories. For the stenosis measurements, the CTA images of 162 arteries yielded an interobserver correlation of 0.78 (P < 0.001). Kappa values of the categorized stenosis measurements were moderate: 0.45 and 0.58 for cutoff values of 30% and 50%, respectively. The kappa value for the calcium categorization was 0.62, with a good agreement between the qualitative and quantitative calcium assessment. Quantitative degree of stenosis measurement of the intracranial ICA on CTA is feasible with a good interobserver agreement ICA. Qualitative calcium categorization agrees well with quantitative measurements. (orig.)

  7. Quantitative and Isolated Measurement of Far-Field Light Scattering by a Single Nanostructure (United States)

    Kim, Donghyeong; Jeong, Kwang-Yong; Kim, Jinhyung; Ee, Ho-Seok; Kang, Ju-Hyung; Park, Hong-Gyu; Seo, Min-Kyo


    Light scattering by nanostructures has facilitated research on various optical phenomena and applications by interfacing the near fields and free-propagating radiation. However, direct quantitative measurement of far-field scattering by a single nanostructure on the wavelength scale or less is highly challenging. Conventional back-focal-plane imaging covers only a limited solid angle determined by the numerical aperture of the objectives and suffers from optical aberration and distortion. Here, we present a quantitative measurement of the differential far-field scattering cross section of a single nanostructure over the full hemisphere. In goniometer-based far-field scanning with a high signal-to-noise ratio of approximately 27.4 dB, weak scattering signals are efficiently isolated and detected under total-internal-reflection illumination. Systematic measurements reveal that the total and differential scattering cross sections of a Au nanorod are determined by the plasmonic Fabry-Perot resonances and the phase-matching conditions to the free-propagating radiation, respectively. We believe that our angle-resolved far-field measurement scheme provides a way to investigate and evaluate the physical properties and performance of nano-optical materials and phenomena.

  8. Cancer and the LGBTQ Population: Quantitative and Qualitative Results from an Oncology Providers' Survey on Knowledge, Attitudes, and Practice Behaviors. (United States)

    Tamargo, Christina L; Quinn, Gwendolyn P; Sanchez, Julian A; Schabath, Matthew B


    Despite growing social acceptance, the LGBTQ population continues to face barriers to healthcare including fear of stigmatization by healthcare providers, and providers' lack of knowledge about LGBTQ-specific health issues. This analysis focuses on the assessment of quantitative and qualitative responses from a subset of providers who identified as specialists that treat one or more of the seven cancers that may be disproportionate in LGBTQ patients. A 32-item web-based survey was emailed to 388 oncology providers at a single institution. The survey assessed: demographics, knowledge, attitudes, and practice behaviors. Oncology providers specializing in seven cancer types had poor knowledge of LGBTQ-specific health needs, with fewer than half of the surveyed providers (49.5%) correctly answering knowledge questions. Most providers had overall positive attitudes toward LGBTQ patients, with 91.7% agreeing they would be comfortable treating this population, and would support education and/or training on LGBTQ-related cancer health issues. Results suggest that despite generally positive attitudes toward the LGBTQ population, oncology providers who treat cancer types most prevalent among the population, lack knowledge of their unique health issues. Knowledge and practice behaviors may improve with enhanced education and training on this population's specific needs.

  9. A method for quantitative measurement of lumbar intervertebral disc structures

    DEFF Research Database (Denmark)

    Tunset, Andreas; Kjær, Per; Samir Chreiteh, Shadi


    There is a shortage of agreement studies relevant for measuring changes over time in lumbar intervertebral disc structures. The objectives of this study were: 1) to develop a method for measurement of intervertebral disc height, anterior and posterior disc material and dural sac diameter using MRI...

  10. Using a novel assessment of procedural proficiency provides medical educators insight into blood pressure measurement. (United States)

    Holmstrup, Michael; Jensen, Brock; Burkart, Rebecca; Levis, Malorie


    This investigation was performed to determine how students in a health sciences program utilize and explain techniques within blood pressure measurement using a novel assessment, and changes associated with greater curricular exposure. An exploratory, qualitative and quantitative study was conducted using a 'Think Aloud' design with protocol analysis. Following familiarization, participants performed the task of measuring blood pressure on a reference subject while stating their thought processes. A trained practitioner recorded each participant's procedural proficiency using a standardized rubric. There were 112 participants in the study with varying levels of curricular exposure to blood pressure measurement. Four trends are noted. Specifically, a trend was observed wherein a marked increase in procedural proficiency with a plateau occurred (e.g. released cuff pressure 2-4 mmHg, 10%, 60%, 83%, 82%). Secondly, a trend was observed with improvement across groups (e.g. cuff placed snugly/smoothly on upper arm, 20%, 60%, 81%, and 91%). Other trends included a marked improvement with subsequent decrease, and an improvement without achieving proficiency (e.g. palpation of the brachial pulse, 5%, 90%, 81%, 68%, appropriate size cuff, 17%, 40%, 33%, 41%, respectively). Qualitatively, transcript interpretation resulted in a need for clarification in the way blood pressure procedure is instructed in the curriculum. The current investigation provides a snapshot of proficiency in blood pressure assessment across a curriculum and highlights considerations for best instructional practices, including the use of Think Aloud. Consequently, medical educators should use qualitative and quantitative assessments concurrently to determine achievement of blood pressure skill proficiency.

  11. Disordered Speech Assessment Using Automatic Methods Based on Quantitative Measures

    Directory of Open Access Journals (Sweden)

    Christine Sapienza


    Full Text Available Speech quality assessment methods are necessary for evaluating and documenting treatment outcomes of patients suffering from degraded speech due to Parkinson's disease, stroke, or other disease processes. Subjective methods of speech quality assessment are more accurate and more robust than objective methods but are time-consuming and costly. We propose a novel objective measure of speech quality assessment that builds on traditional speech processing techniques such as dynamic time warping (DTW and the Itakura-Saito (IS distortion measure. Initial results show that our objective measure correlates well with the more expensive subjective methods.

  12. Quantitative Electrochemical Measurements using in situ ec-S/TEM Devices

    Energy Technology Data Exchange (ETDEWEB)

    Unocic, Raymond R [ORNL; Sacci, Robert L [ORNL; Brown, Gilbert M [ORNL; Veith, Gabriel M [ORNL; Dudney, Nancy J [ORNL; More, Karren Leslie [ORNL; Gardiner, Daniel [Protochips Inc., Raleigh, NC; Walden II, Franklin S [Protochips Inc., Raleigh, NC; Damiano, John [Protochips Inc., Raleigh, NC; Nackashi, David P. [Protochips Inc., Raleigh, NC


    Insight into dynamic electrochemical processes can be obtained with in situ ec-S/TEM, which utilizes microfluidic electrochemical cells to characterize electrochemical processes with S/TEM imaging, diffraction or spectroscopy. The microfluidic electrochemical cell is composed of microfabricated devices with glassy carbon and platinum microband electrodes in a three-electrode cell configuration. To establish the validity of this method for quantitative in situ electrochemistry research, cyclic voltammetry, choronoamperometry and electrochemical impedance spectroscopy were performed using a standard one electron transfer redox couple using a [Fe(CN)6]3-/4- based electrolyte. Established relationships of the electrode geometry and microfluidic conditions were fitted with cyclic voltammetry and chronoamperometic measurements of analyte diffusion coefficients and was found to agree with well-accepted values that are on the order of 10-5 cm2 s-1. Influence of the electron beam on electrochemical measurements was found to be negligible during CV scans where the current profile varied only within a few nA with the electron beam on and off which is well within the hysteresis between multiple CV scans. The combination of experimental results provides a validation that quantitative electrochemistry experiments can be performed with these small-scale microfluidic electrochemical cells provided that accurate geometrical electrode configurations, diffusion boundary layers and microfluidic conditions are accounted for.

  13. Quantitative measurement of redox potential in hypoxic cells using SERS nanosensors. (United States)

    Jiang, Jing; Auchinvole, Craig; Fisher, Kate; Campbell, Colin J


    Hypoxia is considered to be a reductive disorder of cells that is caused either by a lack of oxygen or by the dysregulation of metabolic pathways and is thought to play a role in the pathology of diseases including stroke and cancer. One aspect of hypoxia that remains poorly investigated is the dysregulation of cellular redox potential and its role in controlling biological pathway activation. Since there is currently no way of quantitatively measuring the intracellular redox potential of hypoxic cells, this provided us with the motivation to develop optical nanosensors whose Surface-Enhanced Raman (SER) spectrum provides a quantitative measure of redox potential in hypoxic cells. Our nanosensors are made from organic reporter molecules that show oxidation-state-dependent changes in the Raman spectrum and are chemically adsorbed onto gold nanoshells. These nanosensors can be taken up by cells, and by collecting the SER spectrum we can calculate the localised intracellular redox potential from single hypoxic cells in a non-invasive, reversible way.

  14. Quantitative blood flow measurements in the small animal cardiopulmonary system using digital subtraction angiography

    Energy Technology Data Exchange (ETDEWEB)

    Lin Mingde; Marshall, Craig T.; Qi, Yi; Johnston, Samuel M.; Badea, Cristian T.; Piantadosi, Claude A.; Johnson, G. Allan [Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States); Division of Pulmonary and Critical Care Medicine and Center for Hyperbaric Medicine and Environmental Physiology, Duke University Medical Center, Box 3823, Durham, North Carolina 27710 (United States); Department of Radiology, Center for In Vivo Microscopy and Department of Biomedical Engineering, Duke University Medical Center, Box 3302, Durham, North Carolina 27710 (United States)


    Purpose: The use of preclinical rodent models of disease continues to grow because these models help elucidate pathogenic mechanisms and provide robust test beds for drug development. Among the major anatomic and physiologic indicators of disease progression and genetic or drug modification of responses are measurements of blood vessel caliber and flow. Moreover, cardiopulmonary blood flow is a critical indicator of gas exchange. Current methods of measuring cardiopulmonary blood flow suffer from some or all of the following limitations--they produce relative values, are limited to global measurements, do not provide vasculature visualization, are not able to measure acute changes, are invasive, or require euthanasia. Methods: In this study, high-spatial and high-temporal resolution x-ray digital subtraction angiography (DSA) was used to obtain vasculature visualization, quantitative blood flow in absolute metrics (ml/min instead of arbitrary units or velocity), and relative blood volume dynamics from discrete regions of interest on a pixel-by-pixel basis (100x100 {mu}m{sup 2}). Results: A series of calibrations linked the DSA flow measurements to standard physiological measurement using thermodilution and Fick's method for cardiac output (CO), which in eight anesthetized Fischer-344 rats was found to be 37.0{+-}5.1 ml/min. Phantom experiments were conducted to calibrate the radiographic density to vessel thickness, allowing a link of DSA cardiac output measurements to cardiopulmonary blood flow measurements in discrete regions of interest. The scaling factor linking relative DSA cardiac output measurements to the Fick's absolute measurements was found to be 18.90xCO{sub DSA}=CO{sub Fick}. Conclusions: This calibrated DSA approach allows repeated simultaneous visualization of vasculature and measurement of blood flow dynamics on a regional level in the living rat.

  15. Towards quantitative photoacoustic tomography by acoustooptically measured light fluence

    NARCIS (Netherlands)

    Hussain, Altaf; Hondebrink, Erwin; Steenbergen, Wiendelt


    We present a method of measuring fluence using ultrasonic tagging of light in tomographic manner. Proof of concept experiments show that the combined photoacoustics and acousto optics in tomographic settings enable fluence compensated images.

  16. Quantitative measurement of holographic image quality using Adobe Photoshop (United States)

    Wesly, E.


    Measurement of the characteristics of image holograms in regards to diffraction efficiency and signal to noise ratio are demonstrated, using readily available digital cameras and image editing software. Illustrations and case studies, using currently available holographic recording materials, are presented.

  17. Quantitatively measuring the orbital angular momentum density of light : Presentation

    CSIR Research Space (South Africa)

    Dudley, Angela L


    Full Text Available the power and relative phase of each individual mode. Measuring the power of a specific mode requires the complex conjugate of that mode to be programmed as the transmission function [24]: ).()( * rrT ll Ψ...

  18. Variation of quantitative emphysema measurements from CT scans (United States)

    Keller, Brad M.; Reeves, Anthony P.; Henschke, Claudia I.; Barr, R. Graham; Yankelevitz, David F.


    Emphysema is a lung disease characterized by destruction of the alveolar air sacs and is associated with long-term respiratory dysfunction. CT scans allow for imaging of the anatomical basis of emphysema, and several measures have been introduced for the quantification of the extent of disease. In this paper we compare these measures for repeatability over time. The measures of interest in this study are emphysema index, mean lung density, histogram percentile, and the fractal dimension. To allow for direct comparisons, the measures were normalized to a 0-100 scale. These measures have been computed for a set of 2,027 scan pairs in which the mean interval between scans was 1.15 years (σ: 93 days). These independent pairs were considered with respect to three different scanning conditions (a) 223 pairs where both were scanned with a 5 mm slice thickness protocol, (b) 695 with the first scanned with the 5 mm protocol and the second with a 1.25 mm protocol, and (c) 1109 pairs scanned both times using a 1.25 mm protocol. We found that average normalized emphysema index and histogram percentiles scores increased by 5.9 and 11 points respectively, while the fractal dimension showed stability with a mean difference of 1.2. We also found, a 7 point bias introduced for emphysema index under condition (b), and that the fractal dimension measure is least affected by scanner parameter changes.

  19. A quantitative evaluation of confidence measures for stereo vision. (United States)

    Hu, Xiaoyan; Mordohai, Philippos


    We present an extensive evaluation of 17 confidence measures for stereo matching that compares the most widely used measures as well as several novel techniques proposed here. We begin by categorizing these methods according to which aspects of stereo cost estimation they take into account and then assess their strengths and weaknesses. The evaluation is conducted using a winner-take-all framework on binocular and multibaseline datasets with ground truth. It measures the capability of each confidence method to rank depth estimates according to their likelihood for being correct, to detect occluded pixels, and to generate low-error depth maps by selecting among multiple hypotheses for each pixel. Our work was motivated by the observation that such an evaluation is missing from the rapidly maturing stereo literature and that our findings would be helpful to researchers in binocular and multiview stereo.

  20. Quantitative Spectral Radiance Measurements in the HYMETS Arc Jet (United States)

    Danehy, Paul M.; Hires, Drew V.; Johansen, Craig T.; Bathel, Brett F.; Jones, Stephen B.; Gragg, Jeffrey G.; Splinter, Scott C.


    Calibrated spectral radiance measurements of gaseous emission spectra have been obtained from the HYMETS (Hypersonic Materials Environmental Test System) 400 kW arc-heated wind tunnel at NASA Langley Research Center. A fiber-optic coupled spectrometer collected natural luminosity from the flow. Spectral radiance measurements are reported between 340 and 1000 nm. Both Silicon Carbide (SiC) and Phenolic Impregnated Carbon Ablator (PICA) samples were placed in the flow. Test gases studied included a mostly-N2 atmosphere (95% nitrogen, 5% argon), a simulated Earth Air atmosphere (75% nitrogen, 20% oxygen, 5% argon) and a simulated Martian atmosphere (71% carbon dioxide, 24% nitrogen, 5% argon). The bulk enthalpy of the flow was varied as was the location of the measurement. For the intermediate flow enthalpy tested (20 MJ/kg), emission from the Mars simulant gas was about 10 times higher than the Air flow and 15 times higher than the mostly-N2 atmosphere. Shock standoff distances were estimated from the spectral radiance measurements. Within-run, run-to-run and day-to-day repeatability of the emission were studied, with significant variations (15-100%) noted.

  1. Measuring thin films using quantitative frustrated total internal reflection (FTIR)

    NARCIS (Netherlands)

    Shirota, Minori; van Limbeek, Michiel A.J.; Lohse, Detlef; Sun, Chao


    Abstract.: In the study of interactions between liquids and solids, an accurate measurement of the film thickness between the two media is essential to study the dynamics. As interferometry is restricted by the wavelength of the light source used, recent studies of thinner films have prompted the

  2. Cultural Values Predicting Acculturation Orientations: Operationalizing a Quantitative Measure (United States)

    Ehala, Martin


    This article proposes that acculturation orientations are related to two sets of cultural values: utilitarianism (Ut) and traditionalism (Tr). While utilitarian values enhance assimilation, traditional values support language and identity maintenance. It is proposed that the propensity to either end of this value opposition can be measured by an…

  3. Quantitative approach to measuring the cerebrospinal fluid space with CT

    Energy Technology Data Exchange (ETDEWEB)

    Zeumer, H.; Hacke, W.; Hartwich, P.


    A method for measuring the subarachnoid space by using an independent CT evaluation unit is described. The normal values have been calculated for patients, according to age, and three examples are presented demonstrating reversible decrease of brain volume in patients suffering anorexia nervosa and chronic alcoholism.

  4. Measuring the functional redundancy of biological communities: a quantitative guide

    Czech Academy of Sciences Publication Activity Database

    Ricotta, C.; de Bello, Francesco; Moretti, M.; Caccianiga, M.; Cerabolini, B. E. L.; Pavoine, S.


    Roč. 7, č. 11 (2016), s. 1386-1395 ISSN 2041-210X Institutional support: RVO:67985939 Keywords : absolute vs. relative measures * community structure * functional uniqueness Subject RIV: EH - Ecology, Behaviour Impact factor: 5.708, year: 2016

  5. Challenge in Enhancing the Teaching and Learning of Variable Measurements in Quantitative Research (United States)

    Kee, Chang Peng; Osman, Kamisah; Ahmad, Fauziah


    Statistical analysis is one component that cannot be avoided in a quantitative research. Initial observations noted that students in higher education institution faced difficulty analysing quantitative data which were attributed to the confusions of various variable measurements. This paper aims to compare the outcomes of two approaches applied in…

  6. Measurements in quantitative research: how to select and report on research instruments. (United States)

    Hagan, Teresa L


    Measures exist to numerically represent degrees of attributes. Quantitative research is based on measurement and is conducted in a systematic, controlled manner. These measures enable researchers to perform statistical tests, analyze differences between groups, and determine the effectiveness of treatments. If something is not measurable, it cannot be tested.

  7. Quantitative measurement of out of plane displacement by ESPI and shearrography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Suk; Yoon, Hong Seok; Chang, Ho Seob [Chosun University, Kwangju (Korea, Republic of); Yang, Seung Pil [Dept. of Ophthalmic Optics, Dong A injae College, Youngam (Korea, Republic of); Yoo, Deuk Nam [NAMIN Co.,Ltd, Sacheon (Korea, Republic of)


    The paper described the quantitative measurement of Out-of-plane by Electronic Speckle Pattern Interferometry(ESPI) and Shearography. Shearography is used widely for non-destructive inspection because of less sensitivity to environmental disturbance and simple interferometer. However, it is difficult to determine the defect size quantitatively because there are so many effect factors- shearing distance, shearing direction, and induced load, which depend on operators skill and crack information. These effective factors in Shearography are optimized for quantitative analysis and the size of crack is determined. And also, ESPI is used for determination of crack size quantitatively.

  8. Measurement of the external parameters in quantitative active thermography (United States)

    Olmi, R.; Inglese, G.


    Infrared thermography is widely used in non-destructive testing and in the non-destructive evaluation of subsurface defects in several materials. The detection and reconstruction (location and shape) of a defect inside a material from thermal data requires the solution of an inverse heat conduction problem. Here the problem is tackled by the thin-plate approximation of the investigated domain. A number of physical quantities must be known for the reconstruction procedure to be successful: some relating to the material (thermal conductivity, heat capacity, density), usually known, and others relating to the heating process. This paper proposes procedures for accurately measuring the latter, whose importance is often not given due consideration. Those procedures allow us to accurately measure the heat flux distribution produced by the sources on the heated surface, and the heat exchange coefficient at the remaining surfaces, and are easily applicable in ‘on field’ situations.

  9. Reproducibility of Quantitative Structural and Physiological MRI Measurements (United States)


    frontal lobe trended lower in consistency (Table 7; ICC range...highest values. All measurements were high on the 3% and 10% reproducibility rating scale except for the TE30 frontal lobe (GLU, mI, glutamate...95% CIa] V2 Mean [95% CIa] V3 Mean [95% CIb] MCV (%) [95% CI] MRD (%) [95% CI] ICC Rating (3%)c Rating (10%)c TE135 frontal lobes WM Mean tCho

  10. Seeking Risks: Towards a Quantitative Risk Perception Measure


    Nyre, Åsmund,; Jaatun, Martin,


    Part 1: Cross-Domain Conference and Workshop on Multidisciplinary Research and Practice for Information Systems (CD-ARES 2013); International audience; Existing instruments for measuring risk perception have focused on an abstract version of the concept, without diving into the the details of what forms the perception of likelihood and impact. However, as information security risks become increasingly complex and difficult for users to understand, this approach may be less feasible. The avera...

  11. Curve Distance Measure for Quantitative Evaluation of Myocardial Boundary Tracking


    Adhi Harmoko Saputro; Mohd Marzuki Mustafa; Aini Hussain


    Myocardial boundary tracking is part of feature extraction task for evaluating human cardiac abnormalities. In this case, the feature of myocardial contraction is extracted in the form of the boundary shape movement and alteration such as shape motion, shape deformation. In this paper, a curve distance measure is proposed for evaluating performance of myocardial boundary tracking techniques. The curve is constructed of 9 – 14 control points along the myocardial boundary which is tracked to ...

  12. Quantitative Hardness Measurement by Instrumented AFM-indentation. (United States)

    Caron, Arnaud


    In this work, a combination of amplitude-modulated non-contact atomic force microscopy and atomic force spectroscopy is applied for instrumented hardness measurements on an Au(111) surface with atomistic resolution of single plasticity events. A careful experimental procedure is described that includes the force sensor selection, its calibration, the calibration of the cantilever deflection detection system, and the minimization of instrumental drift for accurate and reproducible force-distance measurements. Also, a method for the data analysis is presented that allows the extraction of force-penetration curves from recorded force-distance curves. A typical curve displays a clear elastic deformation regime up to the first plasticity event, or pop-in, with a length in the range of one to two Burger's vectors. Later plasticity events exhibit the same magnitude. The work of plasticity is further extracted from the measurements. Finally, the hardness is determined in combination with the indentation curve using non-contact atomic force microscopy images of the remaining indents.

  13. A quantitative method for measuring forces applied by nail braces. (United States)

    Erdogan, Fatma G


    Nail bracing is a conservative method used for ingrown nails; however, lack of objective measurements limits its use for various nails. Double-string nail braces with extra metal springs were applied to 12 patients with 21 chronic, thick, and overcurved ingrown nails. Force was measured with a force gauge meter. Treatment was stopped once patients stood on their tiptoes and walked in shoes pain free without braces. A force gauge meter was also used on a model nail to show the forces applied by various nail braces and to compare their pulling forces. After 6 to 10 months of treatment, all of the patients were pain free; 600 to 1,000 centi Newtons of force were applied to the nails. As the width of the nail increased, so did the force. Braces exert more force on larger nails, which may shorten treatment durations. By measuring forces, it may be possible to standardize force and duration of treatment according to variables such as nail thickness, nail width, angle of ingrown nail, and duration of symptoms.

  14. Quantitative evaluation of statistical errors in small-angle X-ray scattering measurements

    Energy Technology Data Exchange (ETDEWEB)

    Sedlak, Steffen M.; Bruetzel, Linda K.; Lipfert, Jan (LMU)


    A new model is proposed for the measurement errors incurred in typical small-angle X-ray scattering (SAXS) experiments, which takes into account the setup geometry and physics of the measurement process. The model accurately captures the experimentally determined errors from a large range of synchrotron and in-house anode-based measurements. Its most general formulation gives for the variance of the buffer-subtracted SAXS intensity σ2(q) = [I(q) + const.]/(kq), whereI(q) is the scattering intensity as a function of the momentum transferq;kand const. are fitting parameters that are characteristic of the experimental setup. The model gives a concrete procedure for calculating realistic measurement errors for simulated SAXS profiles. In addition, the results provide guidelines for optimizing SAXS measurements, which are in line with established procedures for SAXS experiments, and enable a quantitative evaluation of measurement errors.

  15. A quantitative comparison of dura mater tissue structures measured with atomic force microscopy. (United States)

    Sikora, Andrzej; Kedzia, Alicja


    The growth of a human embryo is a very sophisticated process. Understanding the way it proceeds is a key factor in pathology preventing and treating diseases. Therefore one needs to use advanced to tools and methods to investigate various aspects of the anatomy and physiology of humans during the first months of growth. This work is focused on the structure of dura mater tissue, one of the membranes protecting the brain, which can be responsible for a number of health issues if it develops abnormally. The aim of the work was to observe dura mater tissue structure with atomic force microscopy and to provide a quantitative method of discrimination of both the periosteal and meningeal layers in a 6-month-old human embryo. The measurements were performed with atomic force microscopy, in air, using tapping mode. The sample was stored in formaldehyde and dried prior to the measurements. The results obtained permitted observation of the structure of the tissue, in particular the presence of collagen fibers. By applying various image analysis tools, quantitative descriptions of both layers were created in order to distinguish them. The experiment proved that atomic force microscopy can be a useful tool in the investigation of the development process of the dura mater tissue in terms of the appearance of differences related to various functions of the periosteal and meningeal layers.

  16. Quantitative measurement of the orbital angular momentum density of light

    CSIR Research Space (South Africa)

    Dudley, Angela L


    Full Text Available to parti- cles in optical tweezers [2] to the entanglement of OAM in parametric downconversion [3]. Fields that carry OAM of l� per photon, some of which include Laguerre?Gaussian beams [4], Bessel?Gaussian beams [5], and Airy beams [6], have... an azimuthal an- gular dependence of exp�il?� [1,4], where l is the unbounded azimuthal mode index and ? is the azi- muthal angle. Since these fields possessing OAM offer an unbounded state space, they provide a larger bandwidth for quantum cryptography [7...

  17. Teaching to the Test: A Controversial Issue in Quantitative Measurement

    Directory of Open Access Journals (Sweden)

    Jennifer L. Styron


    Full Text Available discussion of the pros and cons of focusing curricular and pedagogical decisions primarily on mastery of those skills and concepts measured by standardized tests. This paper presents scholarly discourse based on testing systems and school accountability, along with a presentation of the advantages and disadvantages of what is commonly referred to as 'teaching to the test.' The authors of this document found research studies to be inconclusive with no clear indication of whether or not there is an advantage or disadvantage to the practice of teaching to the test. But most notably, the actual issue connected to this debate may be the lack of understanding of item-teaching and curricular teaching. In the mind of many educators, item teaching, curriculum teaching and teaching to the test are synonymous.

  18. Laser-induced incandescence: Towards quantitative soot volume fraction measurements

    Energy Technology Data Exchange (ETDEWEB)

    Tzannis, A.P.; Wienbeucker, F.; Beaud, P.; Frey, H.-M.; Gerber, T.; Mischler, B.; Radi, P.P. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)


    Laser-Induced Incandescence has recently emerged as a versatile tool for measuring soot volume fraction in a wide range of combustion systems. In this work we investigate the essential features of the method. LII is based on the acquisition of the incandescence of soot when heated through a high power laser pulse. Initial experiments have been performed on a model laboratory flame. The behaviour of the LII signal is studied experimentally. By applying numerical calculations we investigate the possibility to obtain two-dimensional soot volume fraction distributions. For this purpose a combination of LII with other techniques is required. This part is discussed in some extent and the future work is outlined. (author) 4 figs., 3 refs.

  19. Simultaneous measurement and quantitation of 4-hydroxyphenylacetic acid and dopamine with fast-scan cyclic voltammetry. (United States)

    Shin, Mimi; Kaplan, Sam V; Raider, Kayla D; Johnson, Michael A


    Caged compounds have been used extensively to investigate neuronal function in a variety of preparations, including cell culture, ex vivo tissue samples, and in vivo. As a first step toward electrochemically measuring the extent of caged compound photoactivation while also measuring the release of the catecholamine neurotransmitter, dopamine, fast-scan cyclic voltammetry at carbon-fiber microelectrodes (FSCV) was used to electrochemically characterize 4-hydroxyphenylacetic acid (4HPAA) in the absence and presence of dopamine. 4HPAA is a by-product formed during the process of photoactivation of p-hydroxyphenacyl-based caged compounds, such as p-hydroxyphenylglutamate (pHP-Glu). Our data suggest that the oxidation of 4HPAA occurs through the formation of a conjugated species. Moreover, we found that a triangular waveform of -0.4 V to +1.3 V to -0.4 V at 600 V s(-1), repeated every 100 ms, provided an oxidation current of 4HPAA that was enhanced with a limit of detection of 100 nM, while also allowing the detection and quantitation of dopamine within the same scan. Along with quantifying 4HPAA in biological preparations, the results from this work will allow the electrochemical measurement of photoactivation reactions that generate 4HPAA as a by-product as well as provide a framework for measuring the photorelease of electroactive by-products from caged compounds that incorporate other chromophores.

  20. An approach to quantitative assessment of crew well-being for providing safety of long-term space missions (United States)

    Bartsev, S. I.; Mezhevikin, V. V.; Okhonin, V. A.

    The main destination of Life Support Systems - to support life and provide crew safety - put the problem of the most effective providing this function. In the scope of the whole mission the safety of crew depends on many interrelating features of space ship, LSS, and scenario of given mission itself. Effective risk mitigation needs optimal minimizing of all risk factors. Effective minimization presumes quantitative presentation of these factors. In the paper an approach to quantitative assessment of quality of life in the scope of previously introduced integrated coefficient of maximum reliability. One of the most significant risk factors is crew fatal mistake. There is always other-than-zero probability of a fatal human mistake in controlling the vehicle, landing module, nuclear reactor or other vital device. It is difficult to estimate the probability of such a mistake, but it is apparent that this probability increases with impaired human health. Under closed air cycling such a condition is highly probable as demonstrated by the Sick Building Syndrome (SBS) in highly sealed, so-called "energy efficient" buildings. Seemingly, the cause of SBS is a set of not completely identified factors, yet, it should be noted that in spite of complete pressurization the crew of Bios-3 did not have complaints typical for SBS. It cannot be ruled out that the higher plants may be the most realistic remedy to reduce the probability of the crew's fatal mistakes. All this gives the way to convert so difficultly formalizable parameter as quality of life into probability of accident. A simple monotonous dependence of deterioration of crew health and probability of a fatal mistake on mission time is discussed. Possible medical-biological experiments for more detailed estimations of this dependency are considered.

  1. Quantitative CT measures of emphysema and airway wall thickness are related to D(L)CO

    DEFF Research Database (Denmark)

    Grydeland, Thomas B; Thorsen, Einar; Dirksen, Asger


    There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness.......There is limited knowledge on the relationship between diffusing capacity of the lung for carbon monoxide (D(L)CO) and quantitative computed tomography (CT) measures of emphysema and airway wall thickness....

  2. Measuring physical inactivity: do current measures provide an accurate view of "sedentary" video game time? (United States)

    Fullerton, Simon; Taylor, Anne W; Dal Grande, Eleonora; Berry, Narelle


    Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames) can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n = 2026) were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children's video game time. A substantial proportion of time that would usually be classified as "sedentary" may actually be spent participating in light to moderate physical activity.

  3. Effect of Voltage Measurement on the Quantitative Identification of Transverse Cracks by Electrical Measurements

    KAUST Repository

    Selvakumaran, Lakshmi


    Electrical tomography can be used as a structural health monitoring technique to identify different damage mechanisms in composite laminates. Previous work has established the link between transverse cracking density and mesoscale conductivity of the ply. Through the mesoscale relationship, the conductivity obtained from electrical tomography can be used as a measure of the transverse cracking density. Interpretation of this measure will be accurate provided the assumptions made during homogenization are valid. One main assumption of mesoscale homogenization is that the electric field is in the plane. Here, we test the validity of this assumption for laminates with varying anisotropy ratios and for different distances between the cracked ply and surface that is instrumented with electrodes. We also show the equivalence in electrical response between measurements from cracked laminates and their equivalent mesoscale counterparts. Finally, we propose some general guidelines on the measurement strategy for maximizing the accuracy of transverse cracks identification.

  4. Quantitative Measures of Immersion in Cloud and the Biogeography of Cloud Forests (United States)

    Lawton, R. O.; Nair, U. S.; Ray, D.; Regmi, A.; Pounds, J. A.; Welch, R. M.


    Sites described as tropical montane cloud forests differ greatly, in part because observers tend to differ in their opinion as to what constitutes frequent and prolonged immersion in cloud. This definitional difficulty interferes with hydrologic analyses, assessments of environmental impacts on ecosystems, and biogeographical analyses of cloud forest communities and species. Quantitative measurements of cloud immersion can be obtained on site, but the observations are necessarily spatially limited, although well-placed observers can examine 10 50 km of a mountain range under rainless conditions. Regional analyses, however, require observations at a broader scale. This chapter discusses remote sensing and modeling approaches that can provide quantitative measures of the spatiotemporal patterns of cloud cover and cloud immersion in tropical mountain ranges. These approaches integrate remote sensing tools of various spatial resolutions and frequencies of observation, digital elevation models, regional atmospheric models, and ground-based observations to provide measures of cloud cover, cloud base height, and the intersection of cloud and terrain. This combined approach was applied to the Monteverde region of northern Costa Rica to illustrate how the proportion of time the forest is immersed in cloud may vary spatially and temporally. The observed spatial variation was largely due to patterns of airflow over the mountains. The temporal variation reflected the diurnal rise and fall of the orographic cloud base, which was influenced in turn by synoptic weather conditions, the seasonal movement of the Intertropical Convergence Zone and the north-easterly trade winds. Knowledge of the proportion of the time that sites are immersed in clouds should facilitate ecological comparisons and biogeographical analyses, as well as land use planning and hydrologic assessments in areas where intensive on-site work is not feasible.

  5. Quantitative and qualitative measures of decomposition: Is there a link?

    Energy Technology Data Exchange (ETDEWEB)

    Eaton, Robert, J.; Sanchez, Felipe, G.


    Decomposition rates of loblolly pine coarse woody debris (CWD) were determined by mass loss and wood density changes for trees that differed in source of mortality (natural, girdle-poison, and felling). Specifically, three treatments were examined: (1) control (CON): natural mortality; (2) CD: 5-fold increase in CWD compared with the CON; and (3) CS: 12-fold increase in snags compared with the CON. The additional CWD in the CD treatment plots and the additional snags in the CS plots were achieved by felling (for the CD plots) or girdling followed by herbicide injection (for the CS plots) select trees in these plots. Consequently,mortality on the CD plots is due to natural causes and felling. Likewise, mortality on the CS plots is due to natural causes and girdle-poison. In each treatment plot, mortality due to natural causes was inventoried since 1997, whereas mortality due to girdle-poison and felling were inventoried since 2001. No significant difference was detected between the rates of decomposition for the CWD on these treatment plots, indicating that source of the tree mortality did not influence rates of decomposition once the tree fell. These experimental measures of decomposition were compared with two decay classification systems (three- and five-unit classifications) to determine linkages. Changes in wood density did not correlate to any decay classification, whereas mass loss had a weak correlation with decay class. However, the large degree of variation limits the utility of decay classification systems in estimating mass loss.

  6. Quantitative Fundus Autofluorescence in Mice: Correlation With HPLC Quantitation of RPE Lipofuscin and Measurement of Retina Outer Nuclear Layer Thickness (United States)

    Sparrow, Janet R.; Blonska, Anna; Flynn, Erin; Duncker, Tobias; Greenberg, Jonathan P.; Secondi, Roberta; Ueda, Keiko; Delori, François C.


    Purpose. Our study was conducted to establish procedures and protocols for quantitative autofluorescence (qAF) measurements in mice, and to report changes in qAF, A2E bisretinoid concentration, and outer nuclear layer (ONL) thickness in mice of different genotypes and age. Methods. Fundus autofluorescence (AF) images (55° lens, 488 nm excitation) were acquired in albino Abca4−/−, Abca4+/−, and Abca4+/+ mice (ages 2–12 months) with a confocal scanning laser ophthalmoscope (cSLO). Gray levels (GLs) in each image were calibrated to an internal fluorescence reference. The bisretinoid A2E was measured by quantitative high performance liquid chromatography (HPLC). Histometric analysis of ONL thicknesses was performed. Results. The Bland-Altman coefficient of repeatability (95% confidence interval) was ±18% for between-session qAF measurements. Mean qAF values increased with age (2–12 months) in all groups of mice. qAF was approximately 2-fold higher in Abca4−/− mice than in Abca4+/+ mice and approximately 20% higher in heterozygous mice. HPLC measurements of the lipofuscin fluorophore A2E also revealed age-associated increases, and the fold difference between Abca4−/− and wild-type mice was more pronounced (approximately 3–4-fold) than measurable by qAF. Moreover, A2E levels declined after 8 months of age, a change not observed with qAF. The decline in A2E levels in the Abca4−/− mice corresponded to reduced photoreceptor cell viability as reflected in ONL thinning beginning at 8 months of age. Conclusions. The qAF method enables measurement of in vivo lipofuscin and the detection of genotype and age-associated differences. The use of this approach has the potential to aid in understanding retinal disease processes and will facilitate preclinical studies. PMID:23548623

  7. Quantitative assessment based on kinematic measures of functional impairments during upper extremity movements: A review. (United States)

    de los Reyes-Guzmán, Ana; Dimbwadyo-Terrer, Iris; Trincado-Alonso, Fernando; Monasterio-Huelin, Félix; Torricelli, Diego; Gil-Agudo, Angel


    Quantitative measures of human movement quality are important for discriminating healthy and pathological conditions and for expressing the outcomes and clinically important changes in subjects' functional state. However the most frequently used instruments for the upper extremity functional assessment are clinical scales, that previously have been standardized and validated, but have a high subjective component depending on the observer who scores the test. But they are not enough to assess motor strategies used during movements, and their use in combination with other more objective measures is necessary. The objective of the present review is to provide an overview on objective metrics found in literature with the aim of quantifying the upper extremity performance during functional tasks, regardless of the equipment or system used for registering kinematic data. A search in Medline, Google Scholar and IEEE Xplore databases was performed following a combination of a series of keywords. The full scientific papers that fulfilled the inclusion criteria were included in the review. A set of kinematic metrics was found in literature in relation to joint displacements, analysis of hand trajectories and velocity profiles. These metrics were classified into different categories according to the movement characteristic that was being measured. These kinematic metrics provide the starting point for a proposed objective metrics for the functional assessment of the upper extremity in people with movement disorders as a consequence of neurological injuries. Potential areas of future and further research are presented in the Discussion section. Copyright © 2014 Elsevier Ltd. All rights reserved.

  8. Quantitative Assessment of Parkinsonian Tremor Based on an Inertial Measurement Unit. (United States)

    Dai, Houde; Zhang, Pengyue; Lueth, Tim C


    Quantitative assessment of parkinsonian tremor based on inertial sensors can provide reliable feedback on the effect of medication. In this regard, the features of parkinsonian tremor and its unique properties such as motor fluctuations and dyskinesia are taken into account. Least-square-estimation models are used to assess the severities of rest, postural, and action tremors. In addition, a time-frequency signal analysis algorithm for tremor state detection was also included in the tremor assessment method. This inertial sensor-based method was verified through comparison with an electromagnetic motion tracking system. Seven Parkinson's disease (PD) patients were tested using this tremor assessment system. The measured tremor amplitudes correlated well with the judgments of a neurologist (r = 0.98). The systematic analysis of sensor-based tremor quantification and the corresponding experiments could be of great help in monitoring the severity of parkinsonian tremor.

  9. Measuring edge importance: a quantitative analysis of the stochastic shielding approximation for random processes on graphs. (United States)

    Schmidt, Deena R; Thomas, Peter J


    Mathematical models of cellular physiological mechanisms often involve random walks on graphs representing transitions within networks of functional states. Schmandt and Galán recently introduced a novel stochastic shielding approximation as a fast, accurate method for generating approximate sample paths from a finite state Markov process in which only a subset of states are observable. For example, in ion-channel models, such as the Hodgkin-Huxley or other conductance-based neural models, a nerve cell has a population of ion channels whose states comprise the nodes of a graph, only some of which allow a transmembrane current to pass. The stochastic shielding approximation consists of neglecting fluctuations in the dynamics associated with edges in the graph not directly affecting the observable states. We consider the problem of finding the optimal complexity reducing mapping from a stochastic process on a graph to an approximate process on a smaller sample space, as determined by the choice of a particular linear measurement functional on the graph. The partitioning of ion-channel states into conducting versus nonconducting states provides a case in point. In addition to establishing that Schmandt and Galán's approximation is in fact optimal in a specific sense, we use recent results from random matrix theory to provide heuristic error estimates for the accuracy of the stochastic shielding approximation for an ensemble of random graphs. Moreover, we provide a novel quantitative measure of the contribution of individual transitions within the reaction graph to the accuracy of the approximate process.

  10. Advances in Surface Plasmon Resonance Imaging enable quantitative measurement of laterally heterogeneous coatings of nanoscale thickness (United States)

    Raegen, Adam; Reiter, Kyle; Clarke, Anthony; Lipkowski, Jacek; Dutcher, John


    The Surface Plasmon Resonance (SPR) phenomenon is routinely exploited to qualitatively probe changes to the optical properties of nanoscale coatings on thin metallic surfaces, for use in probes and sensors. Unfortunately, extracting truly quantitative information is usually limited to a select few cases - uniform absorption/desorption of small biomolecules and films, in which a continuous ``slab'' model is a good approximation. We present advancements in the SPR technique that expand the number of cases for which the technique can provide meaningful results. Use of a custom, angle-scanning SPR imaging system, together with a refined data analysis method, allow for quantitative kinetic measurements of laterally heterogeneous systems. We first demonstrate the directionally heterogeneous nature of the SPR phenomenon using a directionally ordered sample, then show how this allows for the calculation of the average coverage of a heterogeneous sample. Finally, the degradation of cellulose microfibrils and bundles of microfibrils due to the action of cellulolytic enzymes will be presented as an excellent example of the capabilities of the SPR imaging system.

  11. Noninvasive and quantitative intracranial pressure estimation using ultrasonographic measurement of optic nerve sheath diameter. (United States)

    Wang, Li-Juan; Yao, Yan; Feng, Liang-Shu; Wang, Yu-Zhi; Zheng, Nan-Nan; Feng, Jia-Chun; Xing, Ying-Qi


    We aimed to quantitatively assess intracranial pressure (ICP) using optic nerve sheath diameter (ONSD) measurements. We recruited 316 neurology patients in whom ultrasonographic ONSD was measured before lumbar puncture. They were randomly divided into a modeling and a test group at a ratio of 7:3. In the modeling group, we conducted univariate and multivariate analyses to assess associations between ICP and ONSD, age, sex, BMI, mean arterial blood pressure, diastolic blood pressure. We derived the mathematical function "Xing &Wang" from the modelling group to predict ICP and evaluated the function in the test group. In the modeling group, ICP was strongly correlated with ONSD (r = 0.758, p Durbin-Watson value = 1.94). In the test group, a significant correlation was found between the observed and predicted ICP (r = 0.76, p < 0.001). Bland-Altman analysis yielded a mean difference between measurements of -0.07 ± 41.55 mmH2O. The intraclass correlation coefficient and its 95%CIs for noninvasive ICP assessments using our prediction model was 0.86 (0.79-0.90). Ultrasonographic ONSD measurements provide a potential noninvasive method to quantify ICP that can be conducted at the bedside.

  12. Quantitative muscle strength assessment in duchenne muscular dystrophy: longitudinal study and correlation with functional measures

    Directory of Open Access Journals (Sweden)

    Lerario Alberto


    Full Text Available Abstract Background The aim of this study was to perform a longitudinal assessment using Quantitative Muscle Testing (QMT in a cohort of ambulant boys affected by Duchenne muscular dystrophy (DMD and to correlate the results of QMT with functional measures. This study is to date the most thorough long-term evaluation of QMT in a cohort of DMD patients correlated with other measures, such as the North Star Ambulatory Assessment (NSAA or thee 6-min walk test (6MWT. Methods This is a single centre, prospective, non-randomised, study assessing QMT using the Kin Com® 125 machine in a study cohort of 28 ambulant DMD boys, aged 5 to 12 years. This cohort was assessed longitudinally over a 12 months period of time with 3 monthly assessments for QMT and with assessment of functional abilities, using the NSAA and the 6MWT at baseline and at 12 months only. QMT was also used in a control group of 13 healthy age-matched boys examined at baseline and at 12 months. Results There was an increase in QMT over 12 months in boys below the age of 7.5 years while in boys above the age of 7.5 years, QMT showed a significant decrease. All the average one-year changes were significantly different than those experienced by healthy controls. We also found a good correlation between quantitative tests and the other measures that was more obvious in the stronger children. Conclusion Our longitudinal data using QMT in a cohort of DMD patients suggest that this could be used as an additional tool to monitor changes, providing additional information on segmental strength.

  13. Evaluation of airway protection: Quantitative timing measures versus penetration/aspiration score. (United States)

    Kendall, Katherine A


    Quantitative measures of swallowing function may improve the reliability and accuracy of modified barium swallow (MBS) study interpretation. Quantitative study analysis has not been widely instituted, however, secondary to concerns about the time required to make measures and a lack of research demonstrating impact on MBS interpretation. This study compares the accuracy of the penetration/aspiration (PEN/ASP) scale (an observational visual-perceptual assessment tool) to quantitative measures of airway closure timing relative to the arrival of the bolus at the upper esophageal sphincter in identifying a failure of airway protection during deglutition. Retrospective review of clinical swallowing data from a university-based outpatient clinic. Swallowing data from 426 patients were reviewed. Patients with normal PEN/ASP scores were identified, and the results of quantitative airway closure timing measures for three liquid bolus sizes were evaluated. The incidence of significant airway closure delay with and without a normal PEN/ASP score was determined. Inter-rater reliability for the quantitative measures was calculated. In patients with a normal PEN/ASP score, 33% demonstrated a delay in airway closure on at least one swallow during the MBS study. There was no correlation between PEN/ASP score and airway closure delay. Inter-rater reliability for the quantitative measure of airway closure timing was nearly perfect (intraclass correlation coefficient = 0.973). The use of quantitative measures of swallowing function, in conjunction with traditional visual perceptual methods of MBS study interpretation, improves the identification of airway closure delay, and hence, potential aspiration risk, even when no penetration or aspiration is apparent on the MBS study. 4. Laryngoscope, 127:2314-2318, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Evaluation of Quantitative Measurement Techniques for Head Tremor With Thalamic Deep Brain Stimulation. (United States)

    Chockalingam, Arun; Boggs, Hans; Prusik, Julia; Ramirez-Zamora, Adolfo; Feustel, Paul; Belasen, Abigail; Youn, Youngwon; Fama, Chris; Haller, Jessica; Pilitsis, Julie


    Ventralis intermedius thalamic deep brain stimulation (VIM DBS) has shown to be safe and effective for medically refractory essential tremor (ET). We evaluate the use of quantitative tremor measurement methods for head tremor in ET using a "smart" hat and a smartphone application. We enrolled 13 ET patients who previously underwent VIM DBS. Head and arm tremor was measured ON and OFF stimulation using the clinical gold standard Fahn-Tolosa-Marin Tremor Rating Scale (TRS). Results were then compared to two quantitative measurement techniques: Lift Pulse (smartphone application) and modified Nizet (adapted laser point measurement from Nizet et al.). Spearman's rank correlation was used to compare tremor severity and improvement on stimulation using TRS and quantitative methods to measure tremor. Lift Pulse tremor severity measurement significantly correlated with TRS for head (ρ = 0.53, p measurement significantly correlated with TRS for head (ρ = 0.83, p measurement significantly correlated with TRS for arm tremor (ρ = 0.56, p measurement significantly correlated with TRS for head tremor (ρ = 0.53, p measure head and arm tremor severity. We also show the utility of a "smart" hat to measure head tremor. Modified Nizet technique is more effective for measuring head tremor, while Lift Pulse is an effective measure of tremor severity, especially arm tremor improvement. © 2017 International Neuromodulation Society.

  15. Assessment and Mission Planning Capability For Quantitative Aerothermodynamic Flight Measurements Using Remote Imaging (United States)

    Horvath, Thomas; Splinter, Scott; Daryabeigi, Kamran; Wood, William; Schwartz, Richard; Ross, Martin


    High resolution calibrated infrared imagery of vehicles during hypervelocity atmospheric entry or sustained hypersonic cruise has the potential to provide flight data on the distribution of surface temperature and the state of the airflow over the vehicle. In the early 1980 s NASA sought to obtain high spatial resolution infrared imagery of the Shuttle during entry. Despite mission execution with a technically rigorous pre-planning capability, the single airborne optical system for this attempt was considered developmental and the scientific return was marginal. In 2005 the Space Shuttle Program again sponsored an effort to obtain imagery of the Orbiter. Imaging requirements were targeted towards Shuttle ascent; companion requirements for entry did not exist. The engineering community was allowed to define observation goals and incrementally demonstrate key elements of a quantitative spatially resolved measurement capability over a series of flights. These imaging opportunities were extremely beneficial and clearly demonstrated capability to capture infrared imagery with mature and operational assets of the US Navy and the Missile Defense Agency. While successful, the usefulness of the imagery was, from an engineering perspective, limited. These limitations were mainly associated with uncertainties regarding operational aspects of data acquisition. These uncertainties, in turn, came about because of limited pre-flight mission planning capability, a poor understanding of several factors including the infrared signature of the Shuttle, optical hardware limitations, atmospheric effects and detector response characteristics. Operational details of sensor configuration such as detector integration time and tracking system algorithms were carried out ad hoc (best practices) which led to low probability of target acquisition and detector saturation. Leveraging from the qualified success during Return-to-Flight, the NASA Engineering and Safety Center sponsored an

  16. The reproducibility of quantitative measurements in lumbar magnetic resonance imaging of children from the general population

    DEFF Research Database (Denmark)

    Masharawi, Y; Kjær, Per; Bendix, T


    and disc sagittal wedging at L5 (CCC general population were found to be reproducible indicating a good visualization of immature vertebral anatomic margins on MRIs and an accurate definition of the measurement protocol.......STUDY DESIGN: Quantitative lumbar magnetic resonance imaging (MRI) measurements in children were taken twice and analyzed for intra- and intertester reproducibility. OBJECTIVE: To evaluate the reproducibility of a variety of lumbar quantitative measurements taken from MRIs of children from...... the general population. SUMMARY OF BACKGROUND DATA: The reproducibility of lumbar quantitative measurements has never been tested on MRIs of children from the general population. This is a prerequisite for a reliable anatomic characterization of the immature spine in normal and pathologic conditions. METHODS...

  17. Ecosystem Services Provided by Agroecosystems: A Qualitative and Quantitative Assessment of this Relationship in the Pampa Region, Argentina (United States)

    Rositano, Florencia; Ferraro, Diego Omar


    The development of an analytical framework relating agricultural conditions and ecosystem services (ES) provision could be very useful for developing land-use systems which sustain natural resources for future use. According to this, a conceptual network was developed, based on literature review and expert knowledge, about the functional relationships between agricultural management and ES provision in the Pampa region (Argentina). We selected eight ES to develop this conceptual network: (1) carbon (C) balance, (2) nitrogen (N) balance, (3) groundwater contamination control, (4) soil water balance, (5) soil structural maintenance, (6) N2O emission control, (7) regulation of biotic adversities, and (8) biodiversity maintenance. This conceptual network revealed a high degree of interdependence among ES provided by Pampean agroecosystems, finding two trade-offs, and two synergies among them. Then, we analyzed the conceptual network structure, and found that both environmental and management variables influenced ES provision. Finally, we selected four ES to parameterize and quantify along 10 growing seasons (2000/2001-2009/2010) through a probabilistic methodology called Bayesian Networks. Only N balance was negatively impacted by agricultural management; while C balance, groundwater contamination control, and N2O emission control were not. Outcomes of our work emphasize the idea that qualitative and quantitative methodologies should be implemented together to assess ES provision in Pampean agroecosystems, as well as in other agricultural systems.

  18. Regadenoson provides perfusion results comparable to adenosine in heterogeneous patient populations: a quantitative analysis from the ADVANCE MPI trials. (United States)

    Mahmarian, John J; Peterson, Leif E; Xu, Jiaqiong; Cerqueira, Manuel D; Iskandrian, Ami E; Bateman, Timothy M; Thomas, Gregory S; Nabi, Faisal


    Total and reversible left ventricular (LV) perfusion defect size (PDS) predict patient outcome. Limited data exist as to whether regadenoson induces similar perfusion abnormalities as observed with adenosine. We sought to determine whether regadenoson induces a similar LV PDS as seen with adenosine across varying patient populations. ADVANCE MPI were prospective, double-blind randomized trials comparing regadenoson to standard adenosine myocardial perfusion tomography (SPECT). Following an initial adenosine SPECT, patients were randomized to either regadenoson (N = 1284) or a second adenosine study (N = 660). SPECT quantification was performed blinded to randomization and image sequence. Propensity analysis was used to define comparability of regadenoson and adenosine perfusion results. Baseline clinical and SPECT results were similar in the two randomized groups. There was a close correlation between adenosine and regadenoson-induced total (r (2) = 0.98, P regadenoson vs adenosine, respectively, and irrespective of age, gender, diabetic status, body mass index, or prior cardiovascular history. By propensity analysis, regadenoson-induced total PDS was significantly larger than observed with adenosine. This is the first study to show that regadenoson induces similar, if not larger, perfusion defects than those observed with adenosine across different patient populations and demonstrates the value of quantitative analysis for defining serial changes in SPECT perfusion results. Regadenoson should provide comparable diagnostic and prognostic SPECT information to that obtained with adenosine.

  19. Quantitative Phosphoproteomic Analysis Provides Insight into the Response to Short-Term Drought Stress in Ammopiptanthus mongolicus Roots

    Directory of Open Access Journals (Sweden)

    Huigai Sun


    Full Text Available Drought is one of the major abiotic stresses that negatively affects plant growth and development. Ammopiptanthus mongolicus is an ecologically important shrub in the mid-Asia desert region and used as a model for abiotic tolerance research in trees. Protein phosphorylation participates in the regulation of various biological processes, however, phosphorylation events associated with drought stress signaling and response in plants is still limited. Here, we conducted a quantitative phosphoproteomic analysis of the response of A. mongolicus roots to short-term drought stress. Data are available via the iProx database with project ID IPX0000971000. In total, 7841 phosphorylation sites were found from the 2019 identified phosphopeptides, corresponding to 1060 phosphoproteins. Drought stress results in significant changes in the abundance of 103 phosphopeptides, corresponding to 90 differentially-phosphorylated phosphoproteins (DPPs. Motif-x analysis identified two motifs, including [pSP] and [RXXpS], from these DPPs. Functional enrichment and protein-protein interaction analysis showed that the DPPs were mainly involved in signal transduction and transcriptional regulation, osmotic adjustment, stress response and defense, RNA splicing and transport, protein synthesis, folding and degradation, and epigenetic regulation. These drought-corresponsive phosphoproteins, and the related signaling and metabolic pathways probably play important roles in drought stress signaling and response in A. mongolicus roots. Our results provide new information for understanding the molecular mechanism of the abiotic stress response in plants at the posttranslational level.

  20. Quantitative laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine

    NARCIS (Netherlands)

    Verbiezen, K.; Klein-Douwel, R. J. H.; van Viet, A. P.; Donkerbroek, A. J.; Meerts, W. L.; Dam, N. J.; ter Meulen, J. J.


    We present quantitative, in-cylinder, UV-laser-induced fluorescence measurements of nitric oxide in a heavy-duty Diesel engine. Processing of the raw fluorescence signals includes a detailed correction, based on additional measurements, for the effect of laser beam and fluorescence attenuation, and

  1. Hematoma volume measurement in gradient echo MRI using quantitative susceptibility mapping. (United States)

    Wang, Shuo; Lou, Min; Liu, Tian; Cui, Deqi; Chen, Xiaomei; Wang, Yi


    A novel quantitative susceptibility mapping (QSM) processing technology has been developed to map tissue susceptibility property without blooming artifacts. We hypothesize that hematoma volume measurement on QSM is independent of imaging parameters, eliminating its echo time dependence on gradient echo MRI. Gradient echo MRI of 16 patients with intracerebral hemorrhage was processed with susceptibility-weighted imaging, R2* (=1/T2*) mapping, and QSM at various echo times. Hematoma volumes were measured from these images. Linear regression of hematoma volume versus echo time showed substantial slopes for gradient echo magnitude (0.45±0.31 L/s), susceptibility-weighted imaging (0.52±0.46), and R2* (0.39±0.30) but nearly zero slope for QSM (0.01±0.05). At echo time=20 ms, hematoma volume on QSM was 0.80× that on gradient echo magnitude image (R2=0.99). QSM can provide reliable measurement of hematoma volume, which can be performed rapidly and accurately using a semiautomated segmentation tool.

  2. Mechanistic implications for the formation of the diiron cluster in ribonucleotide reductase provided by quantitative EPR spectroscopy. (United States)

    Pierce, Brad S; Elgren, Timothy E; Hendrich, Michael P


    -peptide (beta(II)) approximately 25 A away. Furthermore, we show that metal incorporation into beta(II) occurs only during the O(2) activation chemistry of the beta(I)-peptide. This is the first direct evidence of an allosteric interaction between the two beta-peptides of R2. Furthermore, this model can explain the generally observed low Fe occupancy of R2. We also demonstrate that metal uptake and this newly observed allosteric effect are buffer dependent. Higher levels of glycerol cause loss of the allosteric effect. Reductive cycling of samples in the presence of Mn(II) produced a novel mixed metal Fe(III)Mn(III)R2 species within the active site of R2. The magnitude of the exchange coupling (J) determined for both the Mn(2)(II)R2 and Fe(III)Mn(III)R2 species was determined to be -1.8 +/- 0.3 and -18 +/- 3 cm(-)(1), respectively. Quantitative spectral simulations for the Fe(III)Mn(III)R2 and mononuclear Mn(II)R2 species are provided. This work represents the first instance where both X- and Q-band simulations of perpendicular and parallel mode spectra were used to quantitatively predict the concentration of a protein bound mononuclear Mn(II) species.

  3. The quantitative measurement of nursing care quality: a systematic review of available instruments. (United States)

    Koy, V; Yunibhand, J; Angsuroch, Y


    Measuring nursing care quality is essential for nursing practice. However, because of its complexity, such a quality is difficult to define and measure appropriately and a review of available instruments to measure this is important. This systematic review reports on contemporary quantitative instruments for evaluating nursing care quality and suggests some directions for further study. A comprehensive search was conducted in 2015 to review five databases CINAHL, HINARI, ScienceDirect, Google and PubMed, and 18 articles met the inclusion criteria. The search covered the earliest literature found up until November 2015. We found that instruments could be categorized from three different measuring perspectives (1) nurses, (2) patients and (3) both nurses and patients. First, only English language literature was sought and only five databases were reviewed. Second, the instruments reviewed are of varying dimensions. Finally, some authors did not provide the psychometric properties of the instruments studied. Many reviews published in peer-reviewed journals have serious methodological flaws that focus on different perspectives in relation to instruments to measure nursing care quality. As the result of this systematic review instruments are focused on different perspectives of nursing care quality for nurse managers. In addition, the findings of this systematic review enhance better understanding of the perspectives in regard to both nurses and patients in the health-care facilities. The results of this systematic review contribute to the ability of nurse managers to improve and consider the measurement of nursing care quality in clinical practice. The first suggests the need to understand the different perceptions of both nurses and patients' instruments regarding NCQ. Also, a health-care quality-related policy should also be formulated to reduce adverse events. The recording system policy must be designed appropriately in order to monitor patient outcomes every year

  4. Quantitative measurement of the nanoparticle size and number concentration from liquid suspensions by atomic force microscopy. (United States)

    Baalousha, M; Prasad, A; Lead, J R


    Microscopy techniques are indispensable to the nanoanalytical toolbox and can provide accurate information on the number size distribution and number concentration of nanoparticles (NPs) at low concentrations (ca. ppt to ppb range) and small sizes (ca. microscopy techniques are limited by the traditional sample preparation based on drying a small volume of suspension of NPs on a microscopy substrate. This method is limited by low recovery of NPs (ca. atomic force microscopy (AFM) that overcomes the above-mentioned shortcomings and allows full recovery and representativeness of the NPs under consideration by forcing the NPs into the substrate via ultracentrifugation and strongly attaches the NPs to the substrate by surface functionalization of the substrate or by adding cations to the NP suspension. The high efficiency of the analysis is demonstrated by the uniformity of the NP distribution on the substrate (that is low variability between the number of NPs counted on different images on different areas of the substrate), the high recovery of the NPs up to 71%) and the good correlation (R > 0.95) between the mass and number concentrations. Therefore, for the first time, we developed a validated quantitative sampling technique that enables the use of the full capabilities of microscopy tools to quantitatively and accurately determine the number size distribution and number concentration of NPs at environmentally relevant low concentrations (i.e. 0.34-100 ppb). This approach is of high environmental relevance and can be applied widely in environmental nanoscience and nanotoxicology for (i) measuring the number concentration dose in nanotoxicological studies and (ii) accurately measuring the number size distribution of NPs; both are key requirements for the implementation of the European Commission recommendation for definition of nanomaterials.

  5. Methods to measure peripheral and central sensitization using quantitative sensory testing: A focus on individuals with low back pain. (United States)

    Starkweather, Angela R; Heineman, Amy; Storey, Shannon; Rubia, Gil; Lyon, Debra E; Greenspan, Joel; Dorsey, Susan G


    Quantitative sensory testing can be used to assess peripheral and central sensitization; important factors that contribute to the individual's experience of pain and disability. Many studies use quantitative sensory testing in patients with low back pain to detect alterations in pain sensitivity, however, because investigators employ different protocols, interpretation of findings across studies can become problematic. The purpose of this article is to propose a standardized method of testing peripheral and central pain sensitization in patients with low back pain. Video clips are provided to demonstrate correct procedures for measuring the response to experimental pain using mechanical, thermal and pressure modalities. As nurse researchers and clinicians increase utilization of quantitative sensory testing to examine pain phenotypes, it is anticipated that more personalized methods for monitoring the trajectory of low back pain and response to treatment will improve outcomes for this patient population. Copyright © 2015 Elsevier Inc. All rights reserved.

  6. Qualitative pattern classification of shear wave elastography for breast masses: How it correlates to quantitative measurements

    Energy Technology Data Exchange (ETDEWEB)

    Yoon, Jung Hyun, E-mail: [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Department of Radiology, Research Institute of Radiological Science, Yonsei University, College of Medicine (Korea, Republic of); Ko, Kyung Hee, E-mail: [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Jung, Hae Kyoung, E-mail: [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of); Lee, Jong Tae, E-mail: [Department of Radiology, CHA Bundang Medical Center, CHA University, School of Medicine (Korea, Republic of)


    Objective: To determine the correlation of qualitative shear wave elastography (SWE) pattern classification to quantitative SWE measurements and whether it is representative of quantitative SWE values with similar performances. Methods: From October 2012 to January 2013, 267 breast masses of 236 women (mean age: 45.12 ± 10.54 years, range: 21–88 years) who had undergone ultrasonography (US), SWE, and subsequent biopsy were included. US BI-RADS final assessment and qualitative and quantitative SWE measurements were recorded. Correlation between pattern classification and mean elasticity, maximum elasticity, elasticity ratio and standard deviation were evaluated. Diagnostic performances of grayscale US, SWE parameters, and US combined to SWE values were calculated and compared. Results: Of the 267 breast masses, 208 (77.9%) were benign and 59 (22.1%) were malignant. Pattern classifications significantly correlated with all quantitative SWE measurements, showing highest correlation with maximum elasticity, r = 0.721 (P < 0.001). Sensitivity was significantly decreased in US combined to SWE measurements to grayscale US: 69.5–89.8% to 100.0%, while specificity was significantly improved: 62.5–81.7% to 13.9% (P < 0.001). Area under the ROC curve (A{sub z}) did not show significant differences between grayscale US to US combined to SWE (P > 0.05). Conclusion: Pattern classification shows high correlation to maximum stiffness and may be representative of quantitative SWE values. When combined to grayscale US, SWE improves specificity of US.

  7. Thermal Breakdown Kinetics of 1-Ethyl-3-Methylimidazolium Ethylsulfate Measured Using Quantitative Infrared Spectroscopy. (United States)

    Wheeler, Jeffrey L; Pugh, McKinley; Atkins, S Jake; Porter, Jason M


    In this work, the thermal stability of the room temperature ionic liquid (RTIL) 1-ethyl-3-methylimidazolium ethylsulfate ([EMIM][EtSO4]) is investigated using infrared (IR) spectroscopy. Quantitative IR absorption spectral data are measured for heated [EMIM][EtSO4]. Spectra have been collected between 25 ℃ and 100 ℃ using a heated optical cell. Multiple samples and cell pathlengths are used to determine quantitative values for the molar absorptivity of [EMIM][EtSO4]. These results are compared to previous computational models of the ion pair. These quantitative spectra are used to measure the rate of thermal decomposition of [EMIM][EtSO4] at elevated temperatures. The spectroscopic measurements of the rate of decomposition show that thermogravimetric methods overestimate the thermal stability of [EMIM][EtSO4].

  8. Investigation of the genetic association between quantitative measures of psychosis and schizophrenia

    DEFF Research Database (Denmark)

    Derks, Eske M; Vorstman, Jacob A S; Ripke, Stephan


    The presence of subclinical levels of psychosis in the general population may imply that schizophrenia is the extreme expression of more or less continuously distributed traits in the population. In a previous study, we identified five quantitative measures of schizophrenia (positive, negative......, disorganisation, mania, and depression scores). The aim of this study is to examine the association between a direct measure of genetic risk of schizophrenia and the five quantitative measures of psychosis. Estimates of the log of the odds ratios of case/control allelic association tests were obtained from...... the Psychiatric GWAS Consortium (PGC) (minus our sample) which included genome-wide genotype data of 8,690 schizophrenia cases and 11,831 controls. These data were used to calculate genetic risk scores in 314 schizophrenia cases and 148 controls from the Netherlands for whom genotype data and quantitative symptom...

  9. Quantitative measurements of electromechanical response with a combined optical beam and interferometric atomic force microscope

    Energy Technology Data Exchange (ETDEWEB)

    Labuda, Aleksander; Proksch, Roger [Asylum Research an Oxford Instruments Company, Santa Barbara, California 93117 (United States)


    An ongoing challenge in atomic force microscope (AFM) experiments is the quantitative measurement of cantilever motion. The vast majority of AFMs use the optical beam deflection (OBD) method to infer the deflection of the cantilever. The OBD method is easy to implement, has impressive noise performance, and tends to be mechanically robust. However, it represents an indirect measurement of the cantilever displacement, since it is fundamentally an angular rather than a displacement measurement. Here, we demonstrate a metrological AFM that combines an OBD sensor with a laser Doppler vibrometer (LDV) to enable accurate measurements of the cantilever velocity and displacement. The OBD/LDV AFM allows a host of quantitative measurements to be performed, including in-situ measurements of cantilever oscillation modes in piezoresponse force microscopy. As an example application, we demonstrate how this instrument can be used for accurate quantification of piezoelectric sensitivity—a longstanding goal in the electromechanical community.

  10. Quantitative measurements of electromechanical response with a combined optical beam and interferometric atomic force microscope (United States)

    Labuda, Aleksander; Proksch, Roger


    An ongoing challenge in atomic force microscope (AFM) experiments is the quantitative measurement of cantilever motion. The vast majority of AFMs use the optical beam deflection (OBD) method to infer the deflection of the cantilever. The OBD method is easy to implement, has impressive noise performance, and tends to be mechanically robust. However, it represents an indirect measurement of the cantilever displacement, since it is fundamentally an angular rather than a displacement measurement. Here, we demonstrate a metrological AFM that combines an OBD sensor with a laser Doppler vibrometer (LDV) to enable accurate measurements of the cantilever velocity and displacement. The OBD/LDV AFM allows a host of quantitative measurements to be performed, including in-situ measurements of cantilever oscillation modes in piezoresponse force microscopy. As an example application, we demonstrate how this instrument can be used for accurate quantification of piezoelectric sensitivity—a longstanding goal in the electromechanical community.

  11. Quantitative Digital Autoradiography for Environmental Swipe Sample Prioritization: System design, Characterization, and Initial Measurements

    Energy Technology Data Exchange (ETDEWEB)

    McDonald, Benjamin S.; Zalavadia, Mital A.; Miller, Brian W.; Bliss, Mary; Olsen, Khris B.; Kasparek, Dustin M.; Clarke, Ardelia M.


    Environmental sampling and sample analyses by the International Atomic Energy Agency’s (IAEA) Network of Analytical Laboratories (NWAL) is a critical technical tool used to detect facility misuse under a Comprehensive Safeguards Agreement and to verify the absence of undeclared nuclear material activities under an Additional Protocol. Currently all environmental swipe samples (ESS) are screened using gamma spectrometry and x-ray fluorescence to estimate the amount of U and/or Pu in the ESS, to guide further analysis, and to assist in the shipment of ESS to the NWAL. Quantitative Digital Autoradiography for Environmental Samples (QDARES) is being developed to complement existing techniques through the use of a portable, real-time, high-spatial-resolution camera called the Ionizing-radiation Quantum Imaging Detector (iQID). The iQID constructs a spatial map of radionuclides within a sample or surface in real-time as charged particles (betas) and photons (gamma/x-rays) are detected and localized on an event-by-event basis. Knowledge of the location and nature of radioactive hot spots on the ESS could provide information for subsequent laboratory analysis. As a nondestructive technique, QDARES does not compromise the ESS chain of custody or subsequent laboratory analysis. In this paper we will present the system design and construction, characterization measurements with calibration sources, and initial measurements of ESS.

  12. Measuring Edge Importance: A Quantitative Analysis of the Stochastic Shielding Approximation for Random Processes on Graphs (United States)


    Mathematical models of cellular physiological mechanisms often involve random walks on graphs representing transitions within networks of functional states. Schmandt and Galán recently introduced a novel stochastic shielding approximation as a fast, accurate method for generating approximate sample paths from a finite state Markov process in which only a subset of states are observable. For example, in ion-channel models, such as the Hodgkin–Huxley or other conductance-based neural models, a nerve cell has a population of ion channels whose states comprise the nodes of a graph, only some of which allow a transmembrane current to pass. The stochastic shielding approximation consists of neglecting fluctuations in the dynamics associated with edges in the graph not directly affecting the observable states. We consider the problem of finding the optimal complexity reducing mapping from a stochastic process on a graph to an approximate process on a smaller sample space, as determined by the choice of a particular linear measurement functional on the graph. The partitioning of ion-channel states into conducting versus nonconducting states provides a case in point. In addition to establishing that Schmandt and Galán’s approximation is in fact optimal in a specific sense, we use recent results from random matrix theory to provide heuristic error estimates for the accuracy of the stochastic shielding approximation for an ensemble of random graphs. Moreover, we provide a novel quantitative measure of the contribution of individual transitions within the reaction graph to the accuracy of the approximate process. PMID:24742077

  13. The effect of systematic measurement errors on atmospheric CO2 inversions: a quantitative assessment

    Directory of Open Access Journals (Sweden)

    C. Rödenbeck


    Full Text Available Surface-atmosphere exchange fluxes of CO2, estimated by an interannual atmospheric transport inversion from atmospheric mixing ratio measurements, are affected by several sources of errors, one of which is experimental errors. Quantitative information about such measurement errors can be obtained from regular co-located measurements done by different laboratories or using different experimental techniques. The present quantitative assessment is based on intercomparison information from the CMDL and CSIRO atmospheric measurement programs. We show that the effects of systematic measurement errors on inversion results are very small compared to other errors in the flux estimation (as well as compared to signal variability. As a practical consequence, this assessment justifies the merging of data sets from different laboratories or different experimental techniques (flask and in-situ, if systematic differences (and their changes are comparable to those considered here. This work also highlights the importance of regular intercomparison programs.

  14. The effect of systematic measurement errors on atmospheric CO2 inversions: a quantitative assessment (United States)

    Rödenbeck, C.; Conway, T. J.; Langenfelds, R. L.


    Surface-atmosphere exchange fluxes of CO2, estimated by an interannual atmospheric transport inversion from atmospheric mixing ratio measurements, are affected by several sources of errors, one of which is experimental errors. Quantitative information about such measurement errors can be obtained from regular co-located measurements done by different laboratories or using different experimental techniques. The present quantitative assessment is based on intercomparison information from the CMDL and CSIRO atmospheric measurement programs. We show that the effects of systematic measurement errors on inversion results are very small compared to other errors in the flux estimation (as well as compared to signal variability). As a practical consequence, this assessment justifies the merging of data sets from different laboratories or different experimental techniques (flask and in-situ), if systematic differences (and their changes) are comparable to those considered here. This work also highlights the importance of regular intercomparison programs.

  15. Issues to Consider When Measuring and Applying Socioeconomic Position Quantitatively in Immigrant Health Research

    Directory of Open Access Journals (Sweden)

    Signe Smith Nielsen


    Full Text Available The relationship between migration and health is complex, yet, immigrant-related inequalities in health are largely influenced by socioeconomic position. Drawing upon previous findings, this paper discusses issues to consider when measuring and applying socioeconomic position in quantitative immigrant health research. When measuring socioeconomic position, it is important to be aware of four aspects: (1 there is a lack of clarity about how socioeconomic position should be measured; (2 different types of socioeconomic position may be relevant to immigrants compared with the native-born population; (3 choices of measures of socioeconomic position in quantitative analyses often rely on data availability; and (4 different measures of socioeconomic position have different effects in population groups. Therefore, caution should be used in the collection, presentation, analyses, and interpretation of data and researchers need to display their proposed conceptual models and data limitations as well as apply different approaches for analyses.

  16. Prediction of Coronal Mass Ejections From Vector Magnetograms: Quantitative Measures as Predictors (United States)

    Falconer, D. A.; Moore, R. L.; Gary, G. A.; Rose, M. Franklin (Technical Monitor)


    We derived two quantitative measures of an active region's global nonpotentiality from the region's vector magnetogram, 1) the net current (I(sub N)), and 2) the length of strong-shear, strong-field main neutral line (Lss), and used these two measures in a pilot study of the CME productivity of 4 active regions. We compared the global nonpotentiality measures to the active regions' CME productivity determined from GOES and Yohkoh/SXT observations. We found that two of the active regions were highly globally nonpotential and were CME productive, while the other two active regions had little global nonpotentiality and produced no CMEs. At the Fall 2000 AGU, we reported on an expanded study (12 active regions and 17 magnetograms) in which we evaluated four quantitative global measures of an active region's magnetic field and compared these measures with the CME productivity. The four global measures (all derived from MSFC vector magnetograms) included our two previous measures (I(sub N) and L(sub ss)) as well as two new ones, the total magnetic flux (PHI) (a measure of an active region's size), and the normalized twist (alpha (bar)= muIN/PHI). We found that the three quantitative measures of global nonpotentiality (I(sub N), L(sub ss), alpha (bar)) were all well correlated (greater than 99% confidence level) with an active region's CME productivity within plus or minus 2 days of the day of the magnetogram. We will now report on our findings of how good our quantitative measures are as predictors of active-region CME productivity, using only CMEs that occurred after the magnetogram. We report the preliminary skill test of these quantitative measures as predictors. We compare the CME prediction success of our quantitative measures to the CME prediction success based on an active region's past CME productivity. We examine the cases of the handful of false positive and false negatives to look for improvements to our predictors. This work is funded by NSF through the Space

  17. Tunable PIE and synchronized gating detections by FastFLIM for quantitative microscopy measurements of fast dynamics of single molecules (United States)

    Sun, Yuansheng; Coskun, Ulas; Ferreon, Allan Chris; Barbieri, Beniamino; Liao, Shih-Chu Jeff


    The crosstalk between two fluorescent species causes problems in fluorescence microscopy imaging, especially for quantitative measurements such as co-localization, Förster resonance energy transfer (FRET), fluorescence cross correlation spectroscopy (FCCS). In laser scanning confocal microscopy, the lasers can be switched on and off by acousto-optic tunable filters (AOTF) in the microsecond scale for alternative line scanning in order to avoid the crosstalk while minimizing the time delay between two lasers on the same pixel location. In contrast, the pulsed interleaved excitation (PIE) technique synchronizes two pulsed lasers of different wavelengths in the nanosecond scale to enable measuring superfast dynamics of two fluorescent species simultaneously and yet quantitatively without the crosstalk contamination. This feature is critical for many cell biology applications, e.g. accurate determination of stoichiometry in FRET measurements for studying protein-protein interactions or cell signal events, detection of weaker bindings in FCCS by eliminating the false cross correlation due to the crosstalk. The PIE has been used with the time correlated single photon counting (TCSPC) electronics. Here, we describe a novel PIE development using the digital frequency domain (DFD) technique -- FastFLIM, which provides tunable PIE setups and synchronized gating detections, tailored and optimized to specific applications. A few PIE setups by FastFLIM and measurement examples are described. Combined with the sensitivity of Alba and Q2 systems, the PIE allowed us to quantitatively measure the fast dynamics of single molecules.

  18. Quantitative Evaluation of MODIS Fire Radiative Power Measurement for Global Smoke Emissions Assessment (United States)

    Ichoku, Charles; Ellison, Luke


    Satellite remote sensing is providing us tremendous opportunities to measure the fire radiative energy (FRE) release rate or power (FRP) from open biomass burning, which affects many vegetated regions of the world on a seasonal basis. Knowledge of the biomass burning characteristics and emission source strengths of different (particulate and gaseous) smoke constituents is one of the principal ingredients upon which the assessment, modeling, and forecasting of their distribution and impacts depend. This knowledge can be gained through accurate measurement of FRP, which has been shown to have a direct relationship with the rates of biomass consumption and emissions of major smoke constituents. Over the last decade or so, FRP has been routinely measured from space by both the MODIS sensors aboard the polar orbiting Terra and Aqua satellites, and the SEVIRI sensor aboard the Meteosat Second Generation (MSG) geostationary satellite. During the last few years, FRP has steadily gained increasing recognition as an important parameter for facilitating the development of various scientific studies and applications relating to the quantitative characterization of biomass burning and their emissions. To establish the scientific integrity of the FRP as a stable quantity that can be measured consistently across a variety of sensors and platforms, with the potential of being utilized to develop a unified long-term climate data record of fire activity and impacts, it needs to be thoroughly evaluated, calibrated, and validated. Therefore, we are conducting a detailed analysis of the FRP products from MODIS to evaluate the uncertainties associated with them, such as those due to the effects of satellite variable observation geometry and other factors, in order to establish their error budget for use in diverse scientific research and applications. In this presentation, we will show recent results of the MODIS FRP uncertainty analysis and error mitigation solutions, and demonstrate

  19. Performance Measurement for a Logistics Services Provider to the Polymer Industry


    Tok, King Lai


    This management project discusses the form of performance measurement system suitable for a logistics services provider who focuses on providing its services to large multinational petrochemical companies in the polymer industry

  20. Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements

    NARCIS (Netherlands)

    Nijholt, J.L.M.


    This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much

  1. A new instrument for measurement and collection of quantitative samples of the litter layer in forests

    National Research Council Canada - National Science Library

    Marimon-Junior, Ben Hur; Hay, John D


    ...; Hairiah et al., 2006 ). The quantitative measurement of the parameters of the litter layer is a powerful tool for the determination of diverse ecological conditions that are of relevant interest in a world context of tropical forests ( Sampaio et al., 1993; Tápia-Coral et al., 2005 ). The physical and chemical properties and biological of...

  2. System for quantitative measurements of methane emission from dairy cattle in Denmark

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Lund, Peter; Johannes, Maike

    for quantitative measurements of methane, based on the principles for an open circuit system for indirect calorimetry. The chambers are transparent (polycarbonate) and open in the bottom, the inlet air is coming from the barn, and air-condition is a simple radiator to cool and condense for dehumidifying...

  3. Growth kinetics of Mycobacterium tuberculosis measured by quantitative resazurin reduction assay: a tool for fitness studies. (United States)

    von Groll, Andrea; Martin, Anandi; Portaels, Françoise; da Silva, Pedro Eduardo Almeida; Palomino, Juan Carlos


    We standardized a method to evaluate the growth kinetics of Mycobacterium tuberculosis by measuring quantitatively the reduction of resazurin by spectrophotometry. Growth curves and the rate of growth of twenty-one M. tuberculosis clinical isolates were determined. The method showed technical simplicity and is inexpensive to assess the fitness of each isolate.

  4. Effects of Suggestopedic Elements on Qualitative and Quantitative Measures of Language Production. (United States)

    Felix, Uschi; Lawson, Michael


    In a 10-week time-series investigation of a class of 12 students, this study looked at whether Suggestopedia affects more sophisticated language skills than recall. Both quantitative and qualitative measures were included to address the criticism that Suggestopedia affects memory skills alone. Findings suggest that Suggestopedia can positively…

  5. The Reliability and Validity of Discrete and Continuous Measures of Psychopathology: A Quantitative Review (United States)

    Markon, Kristian E.; Chmielewski, Michael; Miller, Christopher J.


    In 2 meta-analyses involving 58 studies and 59,575 participants, we quantitatively summarized the relative reliability and validity of continuous (i.e., dimensional) and discrete (i.e., categorical) measures of psychopathology. Overall, results suggest an expected 15% increase in reliability and 37% increase in validity through adoption of a…

  6. Quantitative mixture fraction measurements in combustion system via laser induced breakdown spectroscopy

    KAUST Repository

    Mansour, Mohy S.


    Laser induced breakdown spectroscopy (LIBS) technique has been applied to quantitative mixture fraction measurements in flames. The measured spectra of different mixtures of natural gas and air are used to obtain the calibration parameters for local elemental mass fraction measurements and hence calculate the mixture fraction. The results are compared with the mixture fraction calculations based on the ratios of the spectral lines of H/N elements, H/O elements and C/(N+O) and they show good agreement within the reaction zone of the flames. Some deviations are observed outside the reaction zone. The ability of LIBS technique as a tool for quantitative mixture fraction as well as elemental fraction measurements in reacting and non-reacting of turbulent flames is feasible. © 2014 Elsevier Ltd. All rights reserved.

  7. Reineke’s stand density index: a quantitative and non-unitless measure of stand density (United States)

    Curtis L. VanderSchaaf


    When used as a measure of relative density, Reineke’s stand density index (SDI) can be made unitless by relating the current SDI to a standard density but when used as a quantitative measure of stand density SDI is not unitless. Reineke’s SDI relates the current stand density to an equivalent number of trees per unit area in a stand with a quadratic mean diameter (Dq)...

  8. Theoretical approach on microscopic bases of stochastic functional self-organization: quantitative measures of the organizational degree of the environment

    Energy Technology Data Exchange (ETDEWEB)

    Oprisan, Sorinel Adrian [Department of Psychology, University of New Orleans, New Orleans, LA (United States)]. E-mail:


    There has been increased theoretical and experimental research interest in autonomous mobile robots exhibiting cooperative behaviour. This paper provides consistent quantitative measures of organizational degree of a two-dimensional environment. We proved, by the way of numerical simulations, that the theoretically derived values of the feature are reliable measures of aggregation degree. The slope of the feature's dependence on memory radius leads to an optimization criterion for stochastic functional self-organization. We also described the intellectual heritages that have guided our research, as well as possible future developments. (author)

  9. Resected Brain Tissue, Seizure Onset Zone and Quantitative EEG Measures: Towards Prediction of Post-Surgical Seizure Control. (United States)

    Rummel, Christian; Abela, Eugenio; Andrzejak, Ralph G; Hauf, Martinus; Pollo, Claudio; Müller, Markus; Weisstanner, Christian; Wiest, Roland; Schindler, Kaspar


    Epilepsy surgery is a potentially curative treatment option for pharmacoresistent patients. If non-invasive methods alone do not allow to delineate the epileptogenic brain areas the surgical candidates undergo long-term monitoring with intracranial EEG. Visual EEG analysis is then used to identify the seizure onset zone for targeted resection as a standard procedure. Despite of its great potential to assess the epileptogenicty of brain tissue, quantitative EEG analysis has not yet found its way into routine clinical practice. To demonstrate that quantitative EEG may yield clinically highly relevant information we retrospectively investigated how post-operative seizure control is associated with four selected EEG measures evaluated in the resected brain tissue and the seizure onset zone. Importantly, the exact spatial location of the intracranial electrodes was determined by coregistration of pre-operative MRI and post-implantation CT and coregistration with post-resection MRI was used to delineate the extent of tissue resection. Using data-driven thresholding, quantitative EEG results were separated into normally contributing and salient channels. In patients with favorable post-surgical seizure control a significantly larger fraction of salient channels in three of the four quantitative EEG measures was resected than in patients with unfavorable outcome in terms of seizure control (median over the whole peri-ictal recordings). The same statistics revealed no association with post-operative seizure control when EEG channels contributing to the seizure onset zone were studied. We conclude that quantitative EEG measures provide clinically relevant and objective markers of target tissue, which may be used to optimize epilepsy surgery. The finding that differentiation between favorable and unfavorable outcome was better for the fraction of salient values in the resected brain tissue than in the seizure onset zone is consistent with growing evidence that spatially

  10. CTXA hip--an extension of classical DXA measurements using quantitative CT.

    Directory of Open Access Journals (Sweden)

    Christopher E Cann

    Full Text Available Bone mineral density (BMD estimates for the proximal femur using Dual Energy X-ray Absorptiometry (DXA are currently considered the standard for making a diagnosis of osteoporosis in an individual patient using BMD alone. We have compared BMD results from a commercial Quantitative CT (QCT BMD analysis system, "CTXA Hip", which provides clinical data for the proximal femur, to results from DXA. We have also used CTXA Hip to determine cortical and trabecular contributions to total BMD. Sixty-nine patients were scanned using 3D QCT and DXA. CTXA Hip BMD measurements for Total Hip and Femoral Neck were compared to DXA results. Twenty-two women were scanned at 0, 1, 2 years and CTXA Hip and DXA results analyzed for long-term reproducibility. Long-term reproducibility calculated as root-mean-square averages of SDs in vivo was 0.012 g/cm2 (CV = 1.8% for CTXA Total Hip and 0.011 g/cm2 (CV = 2.0% for CTXA Femoral Neck compared to 0.014 g/cm2 (CV = 2.0% and 0.016 g/cm2 (CV = 2.7%, respectively, for DXA. The correlation of Total Hip BMD CTXA vs. DXA was R = 0.97 and for Femoral Neck was R = 0.95 (SEE 0.044 g/cm2 in both cases. Cortical bone comprised 62±5% (mean ± SD of total hipbone mass in osteoporotic women. CTXA Hip provides substantially the same clinical information as conventional DXA and in addition provides estimates of BMD in separate cortical and trabecular bone compartments, which may be useful in evaluation of bone strength.

  11. Quantitative shearography: error reduction by using more than three measurement channels

    Energy Technology Data Exchange (ETDEWEB)

    Charrett, Tom O. H.; Francis, Daniel; Tatam, Ralph P.


    Shearography is a noncontact optical technique used to measure surface displacement derivatives. Full surface strain characterization can be achieved using shearography configurations employing at least three measurement channels. Each measurement channel is sensitive to a single displacement gradient component defined by its sensitivity vector. A matrix transformation is then required to convert the measured components to the orthogonal displacement gradients required for quantitative strain measurement. This transformation, conventionally performed using three measurement channels, amplifies any errors present in the measurement. This paper investigates the use of additional measurement channels using the results of a computer model and an experimental shearography system. Results are presented showing that the addition of a fourth channel can reduce the errors in the computed orthogonal components by up to 33% and that, by using 10 channels, reductions of around 45% should be possible.

  12. Quantitative shearography: error reduction by using more than three measurement channels. (United States)

    Charrett, Tom O H; Francis, Daniel; Tatam, Ralph P


    Shearography is a noncontact optical technique used to measure surface displacement derivatives. Full surface strain characterization can be achieved using shearography configurations employing at least three measurement channels. Each measurement channel is sensitive to a single displacement gradient component defined by its sensitivity vector. A matrix transformation is then required to convert the measured components to the orthogonal displacement gradients required for quantitative strain measurement. This transformation, conventionally performed using three measurement channels, amplifies any errors present in the measurement. This paper investigates the use of additional measurement channels using the results of a computer model and an experimental shearography system. Results are presented showing that the addition of a fourth channel can reduce the errors in the computed orthogonal components by up to 33% and that, by using 10 channels, reductions of around 45% should be possible.

  13. Extracting quantitative measures from EAP: a small clinical study using BFOR. (United States)

    Hosseinbor, A Pasha; Chung, Moo K; Wu, Yu-Chien; Fleming, John O; Field, Aaron S; Alexander, Andrew L


    The ensemble average propagator (EAP) describes the 3D average diffusion process of water molecules, capturing both its radial and angular contents, and hence providing rich information about complex tissue microstructure properties. Bessel Fourier orientation reconstruction (BFOR) is one of several analytical, non-Cartesian EAP reconstruction schemes employing multiple shell acquisitions that have recently been proposed. Such modeling bases have not yet been fully exploited in the extraction of rotationally invariant q-space indices that describe the degree of diffusion anisotropy/restrictivity. Such quantitative measures include the zero-displacement probability (P(o)), mean squared displacement (MSD), q-space inverse variance (QIV), and generalized fractional anisotropy (GFA), and all are simply scalar features of the EAP. In this study, a general relationship between MSD and q-space diffusion signal is derived and an EAP-based definition of GFA is introduced. A significant part of the paper is dedicated to utilizing BFOR in a clinical dataset, comprised of 5 multiple sclerosis (MS) patients and 4 healthy controls, to estimate P(o), MSD, QIV, and GFA of corpus callosum, and specifically, to see if such indices can detect changes between normal appearing white matter (NAWM) and healthy white matter (WM). Although the sample size is small, this study is a proof of concept that can be extended to larger sample sizes in the future.

  14. Quantitative diffusion and swelling kinetic measurements using large-angle interferometric refractometry. (United States)

    Saunders, John E; Chen, Hao; Brauer, Chris; Clayton, McGregor; Chen, Weijian; Barnes, Jack A; Loock, Hans-Peter


    The uptake and release of sorbates into films and coatings is typically accompanied by changes of the films' refractive index and thickness. We provide a comprehensive model to calculate the concentration of the sorbate from the average refractive index and the film thickness, and validate the model experimentally. The mass fraction of the analyte partitioned into a film is described quantitatively by the Lorentz-Lorenz equation and the Clausius-Mosotti equation. To validate the model, the uptake kinetics of water and other solvents into SU-8 films (d = 40-45 μm) were explored. Large-angle interferometric refractometry measurements can be used to characterize films that are between 15 μm to 150 μm thick and, Fourier analysis, is used to determine independently the thickness, the average refractive index and the refractive index at the film-substrate interface at one-second time intervals. From these values the mass fraction of water in SU-8 was calculated. The kinetics were best described by two independent uptake processes having different rates. Each process followed one-dimensional Fickian diffusion kinetics with diffusion coefficients for water into SU-8 photoresist film of 5.67 × 10(-9) cm(2) s(-1) and 61.2 × 10(-9) cm(2) s(-1).

  15. Non-invasive microstructure and morphology investigation of the mouse lung: qualitative description and quantitative measurement.

    Directory of Open Access Journals (Sweden)

    Lu Zhang

    Full Text Available BACKGROUND: Early detection of lung cancer is known to improve the chances of successful treatment. However, lungs are soft tissues with complex three-dimensional configuration. Conventional X-ray imaging is based purely on absorption resulting in very low contrast when imaging soft tissues without contrast agents. It is difficult to obtain adequate information of lung lesions from conventional X-ray imaging. METHODS: In this study, a recently emerged imaging technique, in-line X-ray phase contrast imaging (IL-XPCI was used. This powerful technique enabled high-resolution investigations of soft tissues without contrast agents. We applied IL-XPCI to observe the lungs in an intact mouse for the purpose of defining quantitatively the micro-structures in lung. FINDINGS: The three-dimensional model of the lung was successfully established, which provided an excellent view of lung airways. We highlighted the use of IL-XPCI in the visualization and assessment of alveoli which had rarely been studied in three dimensions (3D. The precise view of individual alveolus was achieved. The morphological parameters, such as diameter and alveolar surface area were measured. These parameters were of great importance in the diagnosis of diseases related to alveolus and alveolar scar. CONCLUSION: Our results indicated that IL-XPCI had the ability to represent complex anatomical structures in lung. This offered a new perspective on the diagnosis of respiratory disease and may guide future work in the study of respiratory mechanism on the alveoli level.

  16. Robust high-resolution imaging and quantitative force measurement with tuned-oscillator atomic force microscopy (United States)

    Dagdeviren, Omur E.; Götzen, Jan; Hölscher, Hendrik; Altman, Eric I.; Schwarz, Udo D.


    Atomic force microscopy (AFM) and spectroscopy are based on locally detecting the interactions between a surface and a sharp probe tip. For highest resolution imaging, noncontact modes that avoid tip-sample contact are used; control of the tip’s vertical position is accomplished by oscillating the tip and detecting perturbations induced by its interaction with the surface potential. Due to this potential’s nonlinear nature, however, achieving reliable control of the tip-sample distance is challenging, so much so that despite its power vacuum-based noncontact AFM has remained a niche technique. Here we introduce a new pathway to distance control that prevents instabilities by externally tuning the oscillator’s response characteristics. A major advantage of this operational scheme is that it delivers robust position control in both the attractive and repulsive regimes with only one feedback loop, thereby providing an easy-to-implement route to atomic resolution imaging and quantitative tip-sample interaction force measurement.

  17. A quantitative analysis of signal reproduction from cylinder recordings measured via noncontact full surface mapping. (United States)

    Nascè, Antony; Hill, Martyn; McBride, John W; Boltryk, Peter J


    Sound reproduction via a noncontact surface mapping technique has great potential for sound archives, aiming to digitize content from early sound recordings such as wax cylinders, which may otherwise be "unplayable" with a stylus. If the noncontact techniques are to be considered a viable solution for sound archivists, a method for quantifying the quality of the reproduced signal needs to be developed. In this study, a specially produced test cylinder recording, encoded with sinusoids, provides the basis for the first quantitative analysis of signal reproduction from the noncontact full surface mapping method. The sampling and resolution of the measurement system are considered with respect to the requirements for digital archiving of cylinder recordings. Two different methods of audio signal estimation from a discrete groove cross section are described and rated in terms of signal-to-noise ratio and total harmonic distortion. Noncontact and stylus methods of sound reproduction are then compared using the same test cylinder. It is shown that noncontact methods appear to have distinct advantages over stylus reproduction, in terms of reduced harmonic distortion and lower frequency modulation.

  18. Natural language in measuring user emotions : A qualitative approach to quantitative survey-based emotion measurement

    NARCIS (Netherlands)

    Tonetto, L.M.; Desmet, P.M.A.


    This paper presents an approach to developing surveys that measure user experiences with the use of natural everyday language. The common approach to develop questionnaires that measure experience is to translate theoretical factors into verbal survey items. This theory-based approach can impair the

  19. Measuring response to therapy using FDG PET: semi-quantitative and full kinetic analysis

    Energy Technology Data Exchange (ETDEWEB)

    Cheebsumon, Patsuree; Kloet, Reina W.; Hoetjes, Nikie J.; Hoekstra, Otto S.; Lammertsma, Adriaan A.; Boellaard, Ronald [VU University Medical Center, Department of Nuclear Medicine and PET Research, P.O. Box 7057, Amsterdam (Netherlands); Velasquez, Linda M.; Hayes, Wendy [Bristol-Myers Squibb Co., Princeton, NJ (United States); Hoekstra, Corneline J. [Jeroen Bosch Hospital, Department of Nuclear Medicine, Hertogenbosch (Netherlands); Smit, Egbert F. [VU University Medical Center, Department of Respiratory Medicine, Amsterdam (Netherlands)


    Imaging with positron emission tomography (PET) using {sup 18}F-2-fluoro-2-deoxy-D-glucose (FDG) plays an increasingly important role for response assessment in oncology. Several methods for quantifying FDG PET results exist. The goal of this study was to analyse and compare various semi-quantitative measures for response assessment with full kinetic analysis, specifically in assessment of novel therapies. Baseline and response dynamic FDG studies from two different longitudinal studies (study A: seven subjects with lung cancer and study B: six subjects with gastrointestinal cancer) with targeted therapies were reviewed. Quantification of tumour uptake included full kinetic methods, i.e. nonlinear regression (NLR) and Patlak analyses, and simplified measures such as the simplified kinetic method (SKM) and standardized uptake value (SUV). An image-derived input function was used for NLR and Patlak analysis. There were 18 and 9 lesions defined for two response monitoring studies (A and B). In all cases there was excellent correlation between Patlak- and NLR-derived response (R {sup 2} > 0.96). Percentage changes seen with SUV were significantly different from those seen with Patlak for both studies (p < 0.05). After correcting SUV for plasma glucose, SUV and Patlak responses became similar for study A, but large differences remained for study B. Further analysis revealed that differences in responses amongst methods in study B were primarily due to changes in the arterial input functions. Use of simplified methods for assessment of drug efficacy or treatment response may provide different results than those seen with full kinetic analysis. (orig.)

  20. Porous silicon antibody microarrays for quantitative analysis: measurement of free and total PSA in clinical plasma samples. (United States)

    Järås, Kerstin; Adler, Belinda; Tojo, Axel; Malm, Johan; Marko-Varga, György; Lilja, Hans; Laurell, Thomas


    The antibody microarrays have become widespread, but their use for quantitative analyses in clinical samples has not yet been established. We investigated an immunoassay based on nanoporous silicon antibody microarrays for quantification of total prostate-specific-antigen (PSA) in 80 clinical plasma samples, and provide quantitative data from a duplex microarray assay that simultaneously quantifies free and total PSA in plasma. To further develop the assay the porous silicon chips was placed into a standard 96-well microtiter plate for higher throughput analysis. The samples analyzed by this quantitative microarray were 80 plasma samples obtained from men undergoing clinical PSA testing (dynamic range: 0.14-44 ng/ml, LOD: 0.14 ng/ml). The second dataset, measuring free PSA (dynamic range: 0.40-74.9 ng/ml, LOD: 0.47 ng/ml) and total PSA (dynamic range: 0.87-295 ng/ml, LOD: 0.76 ng/ml), was also obtained from the clinical routine. The reference for the quantification was a commercially available assay, the ProStatus PSA Free/Total DELFIA. In an analysis of 80 plasma samples the microarray platform performs well across the range of total PSA levels. This assay might have the potential to substitute for the large-scale microtiter plate format in diagnostic applications. The duplex assay paves the way for a future quantitative multiplex assay, which analyzes several prostate cancer biomarkers simultaneously. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. A magneto-optical microscope for quantitative measurement of magnetic microstructures. (United States)

    Patterson, W C; Garraud, N; Shorman, E E; Arnold, D P


    An optical system is presented to quantitatively map the stray magnetic fields of microscale magnetic structures, with field resolution down to 50 μT and spatial resolution down to 4 μm. The system uses a magneto-optical indicator film (MOIF) in conjunction with an upright reflective polarizing light microscope to generate optical images of the magnetic field perpendicular to the image plane. A novel single light path construction and discrete multi-image polarimetry processing method are used to extract quantitative areal field measurements from the optical images. The integrated system including the equipment, image analysis software, and experimental methods are described. MOIFs with three different magnetic field ranges are calibrated, and the entire system is validated by measurement of the field patterns from two calibration samples.

  2. Quantitative and dynamic measurements of biological fresh samples with X-ray phase contrast tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Masato, E-mail:; Uesugi, Kentaro [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Tsukube, Takuro [Japanese Red Cross Kobe Hospital, 1-3-1 Wakinohamakaigandori, Chuo-ku, Kobe, Hyogo 651-0073 (Japan); Yagi, Naoto [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)


    Quantitative measurements of biological fresh samples based on three-dimensional densitometry using X-ray phase contrast tomography are presented. X-ray phase contrast tomography using a Talbot grating interferometer was applied to biological fresh samples which were not fixed by any fixatives. To achieve a high-throughput measurement for the fresh samples the X-ray phase contrast tomography measurement procedure was improved. The three-dimensional structure of a fresh mouse fetus was clearly depicted as a mass density map using X-ray phase contrast tomography. The mouse fetus measured in the fresh state was then fixed by formalin and measured in the fixed state. The influence of the formalin fixation on soft tissue was quantitatively evaluated by comparing the fresh and fixed samples. X-ray phase contrast tomography was also applied to the dynamic measurement of a biological fresh sample. Morphological changes of a ring-shaped fresh pig aorta were measured tomographically under different degrees of stretching.

  3. Participation of osteoporosis in femoral neck fracture; Bone mineral measurement of proximal femur using quantitative computed tomography

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, Naoto (Gifu Prefectural Tajimi Hospital (Japan))


    Quantitative computed tomography (QCT) was used to measure bone mineral contents of the proximal femur. First, 62 specimens of cancellous bones of the proximal femur obtained at operation were burnt for mineral determination after preoperative QCT measurement to evaluate the relationship between QCT values and ash weight. The findings indicated that QCT measurement of proximal femur was as useful as that of the lumbar spine. Next, 10 groups of 50 men and 50 women ranging in age from the 5th to the 9th decade were tested to define the control mean and range of QCT mineral content of proximal femur, to compare with 32 cases of femoral neck fracture. In women with femoral neck fracture, QCT values of the femoral neck were less than those of the same normal age group except for cases of medial fracture in the 9th decade. This measurement might provide an index for fracture risk. (author).

  4. Design of a Michelson Interferometer for Quantitative Refraction Index Profile Measurements


    Nijholt, J.L.M.


    This book describes the theoretical design of a three camera Michelson interferometer set-up for quantitative refractive index measuerments. Although a two camera system is easier to align and less expensive, a three camera interferometer is preferred because the expected measuring accuracy is much better. Here analytical expressions are found for the calculation of the required alignment accuracy of the interferometer's components: three CCD-cameras (six degrees of freedom each), a quarter w...

  5. A Major Locus for Quantitatively Measured Shank Skin Color Traits in Korean Native Chicken

    Directory of Open Access Journals (Sweden)

    S. Jin


    Full Text Available Shank skin color of Korean native chicken (KNC shows large color variations. It varies from white, yellow, green, bluish or grey to black, whilst in the majority of European breeds the shanks are typically yellow-colored. Three shank skin color-related traits (i.e., lightness [L*], redness [a*], and yellowness [b*] were measured by a spectrophotometer in 585 progeny from 68 nuclear families in the KNC resource population. We performed genome scan linkage analysis to identify loci that affect quantitatively measured shank skin color traits in KNC. All these birds were genotyped with 167 DNA markers located throughout the 26 autosomes. The SOLAR program was used to conduct multipoint variance-component quantitative trait locus (QTL analyses. We detected a major QTL that affects b* value (logarithm of odds [LOD] = 47.5, p = 1.60×10−49 on GGA24 (GGA for Gallus gallus. At the same location, we also detected a QTL that influences a* value (LOD = 14.2, p = 6.14×10−16. Additionally, beta-carotene dioxygenase 2 (BCDO2, the obvious positional candidate gene under the linkage peaks on GGA24, was investigated by the two association tests: i.e., measured genotype association (MGA and quantitative transmission disequilibrium test (QTDT. Significant associations were detected between BCDO2 g.9367 A>C and a* (PMGA = 1.69×10−28; PQTDT = 2.40×10−25. The strongest associations were between BCDO2 g.9367 A>C and b* (PMGA = 3.56×10−66; PQTDT = 1.68×10−65. However, linkage analyses conditional on the single nucleotide polymorphism indicated that other functional variants should exist. Taken together, we demonstrate for the first time the linkage and association between the BCDO2 locus on GGA24 and quantitatively measured shank skin color traits in KNC.

  6. Quantitative Image Recovery From Measured Blind Backscattered Data Using a Globally Convergent Inverse Method (United States)


    Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any oenalty for failing to comply with...MONITOR’S ACRONYM(S) ARO 8. PERFORMING ORGANIZATION REPORT NUMBER 19a. NAME OF RESPONSIBLE PERSON 19b. TELEPHONE NUMBER Michael Klibanov 704-687...Report Number Quantitative image recovery from measured blin Block 13: Supplementary Note © 2012 . Published in IEEE TRANSACTIONS ON GEOSCIENCE AND

  7. Quantitative thermoelastic measurement on a helicopter glass fibre component underneath a surface anti-fretting coating.

    Directory of Open Access Journals (Sweden)

    Costa A.


    Full Text Available Thermoelastic stress analysis (TSA has been applied to measure the first stress invariant on a composite helicopter component under load. The component comprised inner mono-directional glass fiber layers with an outer central plate in glass fiber cloth, covered by an anti-fretting surface coating. In order to obtain quantitative results, a previous calibration of the thermoelastic constant obtained on a composite sample with a similar anti-fretting coating has been necessary.

  8. Quantitative Measurement of Physical Activity in Acute Ischemic Stroke and Transient Ischemic Attack

    DEFF Research Database (Denmark)

    Strømmen, Anna Maria; Christensen, Thomas; Jensen, Kai


    BACKGROUND AND PURPOSE: The purpose of this study was to quantitatively measure and describe the amount and pattern of physical activity in patients within the first week after acute ischemic stroke and transient ischemic attack using accelerometers. METHODS: A total of 100 patients with acute is...... ischemic stroke. The method offers a low cost and noninvasive tool for future clinical interventional physiotherapeutic and early mobilization studies. CLINICAL TRIAL REGISTRATION: URL: Unique identifier: NCT01560520....

  9. The Medicare Electronic Health Record Incentive Program: provider performance on core and menu measures. (United States)

    Wright, Adam; Feblowitz, Joshua; Samal, Lipika; McCoy, Allison B; Sittig, Dean F


    To measure performance by eligible health care providers on CMS's meaningful use measures. Medicare Electronic Health Record Incentive Program Eligible Professionals Public Use File (PUF), which contains data on meaningful use attestations by 237,267 eligible providers through May 31, 2013. Cross-sectional analysis of the 15 core and 10 menu measures pertaining to use of EHR functions reported in the PUF. Providers in the dataset performed strongly on all core measures, with the most frequent response for each of the 15 measures being 90-100 percent compliance, even when the threshold for a particular measure was lower (e.g., 30 percent). PCPs had higher scores than specialists for computerized order entry, maintaining an active medication list, and documenting vital signs, while specialists had higher scores for maintaining a problem list, recording patient demographics and smoking status, and for providing patients with an after-visit summary. In fact, 90.2 percent of eligible providers claimed at least one exclusion, and half claimed two or more. Providers are successfully attesting to CMS's requirements, and often exceeding the thresholds required by CMS; however, some troubling patterns in exclusions are present. CMS should raise program requirements in future years. © Health Research and Educational Trust.

  10. Quantitative Assessment of Parkinsonian Tremor Based on an Inertial Measurement Unit


    Houde Dai; Pengyue Zhang; Lueth, Tim C


    Quantitative assessment of parkinsonian tremor based on inertial sensors can provide reliable feedback on the effect of medication. In this regard, the features of parkinsonian tremor and its unique properties such as motor fluctuations and dyskinesia are taken into account. Least-square-estimation models are used to assess the severities of rest, postural, and action tremors. In addition, a time-frequency signal analysis algorithm for tremor state detection was also included in the tremor as...

  11. Composite Measures of Health Care Provider Performance: A Description of Approaches (United States)

    Shwartz, Michael; Restuccia, Joseph D; Rosen, Amy K


    Context Since the Institute of Medicine’s 2001 report Crossing the Quality Chasm, there has been a rapid proliferation of quality measures used in quality-monitoring, provider-profiling, and pay-for-performance (P4P) programs. Although individual performance measures are useful for identifying specific processes and outcomes for improvement and tracking progress, they do not easily provide an accessible overview of performance. Composite measures aggregate individual performance measures into a summary score. By reducing the amount of data that must be processed, they facilitate (1) benchmarking of an organization’s performance, encouraging quality improvement initiatives to match performance against high-performing organizations, and (2) profiling and P4P programs based on an organization’s overall performance. Methods We describe different approaches to creating composite measures, discuss their advantages and disadvantages, and provide examples of their use. Findings The major issues in creating composite measures are (1) whether to aggregate measures at the patient level through all-or-none approaches or the facility level, using one of the several possible weighting schemes; (2) when combining measures on different scales, how to rescale measures (using z scores, range percentages, ranks, or 5-star categorizations); and (3) whether to use shrinkage estimators, which increase precision by smoothing rates from smaller facilities but also decrease transparency. Conclusions Because provider rankings and rewards under P4P programs may be sensitive to both context and the data, careful analysis is warranted before deciding to implement a particular method. A better understanding of both when and where to use composite measures and the incentives created by composite measures are likely to be important areas of research as the use of composite measures grows. PMID:26626986

  12. Proposal of quantitative measurement of OH radical using planar laser induced fluorescence calibrated by cavity ring-down spectroscopy in turbulent premixed flames (United States)

    Chen, Shuang; Tu, Xiaobo; Su, Tie; Mu, Jinhe; Yang, Furong


    Planar laser induced fluorescence (PLIF) has been a very important species analysis approach in combustion research, but is most often presented qualitatively. Therefore, another supplementary techniques are needed for quantitative PLIF measurement. In this paper, we propose a quantitative OH concentration measurement method using PLIF calibrated by cavity ring-down spectroscopy (CRDS). The CRDS measurement is firstly applied to a methane-air atmospheric pressure flame on a McKenna burner and determine the OH absolute density. Then the PLIF signal is calibrated by the determined OH concentration on the same flame under the same condition. The calibrated PLIF setup is fixed, and another PLIF setup is added to form a two-line OHPLIF thermometry to measure the 2D temperature distribution. Finally, a quantitative OH-PLIF measurement method is provided for the turbulent premixed flame on a Bunsen burner based on this setup.

  13. Visual observation and quantitative measurement of the microwave absorbing effect at X band. (United States)

    Zhao, L; Chen, X; Ong, C K


    We have set up a two-dimensional spatial field mapping system to measure graphically the quasi-free-space electromagnetic wave in a parallel plate waveguide. Our apparatus illustrates a potential application in characterizing the microwave absorbing materials. From the measured mappings of the microwave field, the visualization of spatial physical process and quantitative characterization of reflectivity coefficients can be achieved. This simple apparatus has a remarkable advantage over with conventional testing methods which usually involve huge, expensive anechoic chambers and demand samples of large size.

  14. Extracting quantitative measures from finite length nonlinear timeseries- complex systems approaches (United States)

    Wicks, R.; Chapman, S. C.; Kiyani, K.; Hnat, B.; Dendy, R. O.


    We consider two complex systems approaches to obtaining quantitative measures from `real world' timeseries, such as in situ solar wind observations and geomagnetic indices, where information about the process in not known a priori. The first is statistical- we discuss the problem of obtaining the scaling exponents from the PDF of fluctuations (differenced variables) via PDF collapse and structure functions. If the probability density is heavy tailed, outliers strongly influence the scaling behaviour of the moments. From an operational point of view, we wish to recover the scaling exponents of the underlying process by excluding a minimal population of these outliers. We test these ideas on a synthetically generated symmetric alpha-stable Lèvy process and show that the Lèvy exponent is recovered in up to the 6th order moment after ~0.1-0.5% of the data are excluded. The scaling properties of the excluded outliers can then be tested to provide additional information about the system. We highlight application of this technique to in- situ spacecraft observation of the turbulent solar wind and to geomagnetic indices. The second of these is dynamical- we explore the use of Mutual Information (MI) as a method to determine order- disorder transitions and test this idea on the Viscek `boid' model for flocking. We compare MI with the full system susceptibility we demonstrate that MI can pinpoint the phase transition with reasonable accuracy. We also consider the MI as a tool for detecting nonlinear correlation between different systems with application to `space weather', that is, solar wind triggering of geomagnetic activity on the earth.

  15. Spatially quantitative models for vulnerability analyses and resilience measures in flood risk management: Case study Rafina, Greece (United States)

    Karagiorgos, Konstantinos; Chiari, Michael; Hübl, Johannes; Maris, Fotis; Thaler, Thomas; Fuchs, Sven


    , and data on flash flood intensities. The model is composed of three basic parts: (1) the quantification of flood hazard via hydrologic and hydraulic calculations and the evaluation of flood intensity for various flood scenarios, (2) the determination of exposure to flood hazard using a semi-quantitative method for the determination of the hazard level, which serves the purpose for the spatial evaluation of corresponding quantities and (3) to show potential resilience measures to protect individual households. The aim of the study is to provide a modified framework for quantitative assessment of vulnerability of building damages and to show potential resilience measures to protect individual households.

  16. A novel method for morphological pleomorphism and heterogeneity quantitative measurement: Named cell feature level co-occurrence matrix. (United States)

    Saito, Akira; Numata, Yasushi; Hamada, Takuya; Horisawa, Tomoyoshi; Cosatto, Eric; Graf, Hans-Peter; Kuroda, Masahiko; Yamamoto, Yoichiro


    Recent developments in molecular pathology and genetic/epigenetic analysis of cancer tissue have resulted in a marked increase in objective and measurable data. In comparison, the traditional morphological analysis approach to pathology diagnosis, which can connect these molecular data and clinical diagnosis, is still mostly subjective. Even though the advent and popularization of digital pathology has provided a boost to computer-aided diagnosis, some important pathological concepts still remain largely non-quantitative and their associated data measurements depend on the pathologist's sense and experience. Such features include pleomorphism and heterogeneity. In this paper, we propose a method for the objective measurement of pleomorphism and heterogeneity, using the cell-level co-occurrence matrix. Our method is based on the widely used Gray-level co-occurrence matrix (GLCM), where relations between neighboring pixel intensity levels are captured into a co-occurrence matrix, followed by the application of analysis functions such as Haralick features. In the pathological tissue image, through image processing techniques, each nucleus can be measured and each nucleus has its own measureable features like nucleus size, roundness, contour length, intra-nucleus texture data (GLCM is one of the methods). In GLCM each nucleus in the tissue image corresponds to one pixel. In this approach the most important point is how to define the neighborhood of each nucleus. We define three types of neighborhoods of a nucleus, then create the co-occurrence matrix and apply Haralick feature functions. In each image pleomorphism and heterogeneity are then determined quantitatively. For our method, one pixel corresponds to one nucleus feature, and we therefore named our method Cell Feature Level Co-occurrence Matrix (CFLCM). We tested this method for several nucleus features. CFLCM is showed as a useful quantitative method for pleomorphism and heterogeneity on histopathological image

  17. Methods for quantitative infrared directional-hemispherical and diffuse reflectance measurements using an FTIR and a commercial integrating sphere

    Energy Technology Data Exchange (ETDEWEB)

    Blake, Thomas A.; Johnson, Timothy J.; Tonkyn, Russell G.; Forland, Brenda M.; Myers, Tanya L.; Brauer, Carolyn S.; Su, Yin-Fong; Bernacki, Bruce E.; Hanssen, Leonard; Gonzalez, Gerardo


    Infrared integrating sphere measurements of solid samples are important in providing reference data for contact, standoff and remote sensing applications. At the Pacific Northwest National Laboratory (PNNL) we have developed protocols to measure both the directional-hemispherical ( and diffuse (d) reflectances of powders, liquids, and disks of powders and solid materials using a commercially available, matte gold-coated integrating sphere and Fourier transform infrared spectrometer. Detailed descriptions of the sphere alignment and its use for making these reflectance measurements are given. Diffuse reflectance values were found to be dependent on the bidirectional reflection distribution function (BRDF) of the sample and the solid angle intercepted by the sphere’s specular exclusion port. To determine how well the sphere and protocols produce quantitative reflectance data, measurements were made of three diffuse and two specular standards prepared by the National institute of Standards and Technology (NIST, USA), LabSphere Infragold and Spectralon standards, hand-loaded sulfur and talc powder samples, and water. The five NIST standards behaved as expected: the three diffuse standards had a high degree of “diffuseness,” d/ = D > 0.9, whereas the two specular standards had D ≤ 0.03. The average absolute differences between the NIST and PNNL measurements of the NIST standards for both directional-hemispherical and diffuse reflectances are on the order of 0.01 reflectance units. Other quantitative differences between the PNNL-measured and calibration (where available) or literature reflectance values for these standards and materials are given and the possible origins of discrepancies are discussed. Random uncertainties and estimates of systematic uncertainties are presented. Corrections necessary to provide better agreement between the PNNL reflectance values as measured for the NIST standards and the NIST reflectance values for these same standards are also

  18. Validation and measurement uncertainty estimation in food microbiology: differences between quantitative and qualitative methods

    Directory of Open Access Journals (Sweden)

    Vesna Režić Dereani


    Full Text Available The aim of this research is to describe quality control procedures, procedures for validation and measurement uncertainty (MU determination as an important element of quality assurance in food microbiology laboratory for qualitative and quantitative type of analysis. Accreditation is conducted according to the standard ISO 17025:2007. General requirements for the competence of testing and calibration laboratories, which guarantees the compliance with standard operating procedures and the technical competence of the staff involved in the tests, recently are widely introduced in food microbiology laboratories in Croatia. In addition to quality manual introduction, and a lot of general documents, some of the most demanding procedures in routine microbiology laboratories are measurement uncertainty (MU procedures and validation experiment design establishment. Those procedures are not standardized yet even at international level, and they require practical microbiological knowledge, altogether with statistical competence. Differences between validation experiments design for quantitative and qualitative food microbiology analysis are discussed in this research, and practical solutions are shortly described. MU for quantitative determinations is more demanding issue than qualitative MU calculation. MU calculations are based on external proficiency testing data and internal validation data. In this paper, practical schematic descriptions for both procedures are shown.

  19. Qualitative and quantitative evaluation of in vivo SD-OCT measurement of rat brain. (United States)

    Xie, Yijing; Harsan, Laura-Adela; Bienert, Thomas; Kirch, Robert D; von Elverfeldt, Dominik; Hofmann, Ulrich G


    OCT has been demonstrated as an efficient imaging modality in various biomedical and clinical applications. However, there is a missing link with respect to the source of contrast between OCT and other modern imaging modalities, no quantitative comparison has been demonstrated between them, yet. We evaluated, to our knowledge, for the first time in vivo OCT measurement of rat brain with our previously proposed forward imaging method by both qualitatively and quantitatively correlating OCT with the corresponding T1-weighted and T2-weighted magnetic resonance images, fiber density map (FDM), and two types of histology staining (cresyl violet and acetylcholinesterase AchE), respectively. Brain anatomical structures were identified and compared across OCT, MRI and histology imaging modalities. Noticeable resemblances corresponding to certain anatomical structures were found between OCT and other image profiles. Correlation was quantitatively assessed by estimating correlation coefficient (R) and mutual information (MI). Results show that the 1-D OCT measurements in regards to the intensity profile and estimated attenuation factor, do not have profound linear correlation with the other image modalities suggested from correlation coefficient estimation. However, findings in mutual information analysis demonstrate that there are markedly high MI values in OCT-MRI signals.

  20. Detecting Genetic Interactions for Quantitative Traits Using m-Spacing Entropy Measure

    Directory of Open Access Journals (Sweden)

    Jaeyong Yee


    Full Text Available A number of statistical methods for detecting gene-gene interactions have been developed in genetic association studies with binary traits. However, many phenotype measures are intrinsically quantitative and categorizing continuous traits may not always be straightforward and meaningful. Association of gene-gene interactions with an observed distribution of such phenotypes needs to be investigated directly without categorization. Information gain based on entropy measure has previously been successful in identifying genetic associations with binary traits. We extend the usefulness of this information gain by proposing a nonparametric evaluation method of conditional entropy of a quantitative phenotype associated with a given genotype. Hence, the information gain can be obtained for any phenotype distribution. Because any functional form, such as Gaussian, is not assumed for the entire distribution of a trait or a given genotype, this method is expected to be robust enough to be applied to any phenotypic association data. Here, we show its use to successfully identify the main effect, as well as the genetic interactions, associated with a quantitative trait.

  1. Quantitative MRI and strength measurements in the assessment of muscle quality in Duchenne muscular dystrophy. (United States)

    Wokke, B H; van den Bergen, J C; Versluis, M J; Niks, E H; Milles, J; Webb, A G; van Zwet, E W; Aartsma-Rus, A; Verschuuren, J J; Kan, H E


    The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in 16 Duchenne patients and 11 controls (aged 8-15). To determine specific muscle strength, four leg muscle groups (quadriceps femoris, hamstrings, anterior tibialis and triceps surae) were measured and related to the amount of contractile tissue. In patients, the quadriceps femoris showed decreased total and contractile cross sectional area, attributable to muscle atrophy. The total, but not the contractile, cross sectional area of the triceps surae was increased in patients, corresponding to hypertrophy. Specific strength decreased in all four muscle groups of Duchenne patients, indicating reduced muscle quality. This suggests that muscle hypertrophy and fatty infiltration are two distinct pathological processes, differing between muscle groups. Additionally, the quality of remaining muscle fibers is severely reduced in the legs of Duchenne patients. The combination of quantitative MRI and quantitative muscle testing could be a valuable outcome parameter in longitudinal studies and in the follow-up of therapeutic effects. Copyright © 2014 Elsevier B.V. All rights reserved.

  2. Quantitative phosphoproteomics of murine Fmr1-KO cell lines provides new insights into FMRP-dependent signal transduction mechanisms. (United States)

    Matic, Katarina; Eninger, Timo; Bardoni, Barbara; Davidovic, Laetitia; Macek, Boris


    Fragile X mental retardation protein (FMRP) is an RNA-binding protein that has a major effect on neuronal protein synthesis. Transcriptional silencing of the FMR1 gene leads to loss of FMRP and development of Fragile X syndrome (FXS), the most common known hereditary cause of intellectual impairment and autism. Here we utilize SILAC-based quantitative phosphoproteomics to analyze murine FMR1(-) and FMR1(+) fibroblastic cell lines derived from FMR1-KO embryos to identify proteins and phosphorylation sites dysregulated as a consequence of FMRP loss. We quantify FMRP-related changes in the levels of 5,023 proteins and 6,133 phosphorylation events and map them onto major signal transduction pathways. Our study confirms global downregulation of the MAPK/ERK pathway and decrease in phosphorylation level of ERK1/2 in the absence of FMRP, which is connected to attenuation of long-term potentiation. We detect differential expression of several key proteins from the p53 pathway, pointing to the involvement of p53 signaling in dysregulated cell cycle control in FXS. Finally, we detect differential expression and phosphorylation of proteins involved in pre-mRNA processing and nuclear transport, as well as Wnt and calcium signaling, such as PLC, PKC, NFAT, and cPLA2. We postulate that calcium homeostasis is likely affected in molecular pathogenesis of FXS.

  3. Quantitative analysis of oyster larval proteome provides new insights into the effects of multiple climate change stressors

    KAUST Repository

    Dineshram, Ramadoss


    The metamorphosis of planktonic larvae of the Pacific oyster (Crassostrea gigas) underpins their complex life-history strategy by switching on the molecular machinery required for sessile life and building calcite shells. Metamorphosis becomes a survival bottleneck, which will be pressured by different anthropogenically induced climate change-related variables. Therefore, it is important to understand how metamorphosing larvae interact with emerging climate change stressors. To predict how larvae might be affected in a future ocean, we examined changes in the proteome of metamorphosing larvae under multiple stressors: decreased pH (pH 7.4), increased temperature (30 °C), and reduced salinity (15 psu). Quantitative protein expression profiling using iTRAQ-LC-MS/MS identified more than 1300 proteins. Decreased pH had a negative effect on metamorphosis by down-regulating several proteins involved in energy production, metabolism, and protein synthesis. However, warming switched on these down-regulated pathways at pH 7.4. Under multiple stressors, cell signaling, energy production, growth, and developmental pathways were up-regulated, although metamorphosis was still reduced. Despite the lack of lethal effects, significant physiological responses to both individual and interacting climate change related stressors were observed at proteome level. The metamorphosing larvae of the C. gigas population in the Yellow Sea appear to have adequate phenotypic plasticity at the proteome level to survive in future coastal oceans, but with developmental and physiological costs. © 2016 John Wiley & Sons Ltd.

  4. Quantitative measurement of ultraviolet-induced damage in cellular DNA by an enzyme immunodot assay

    Energy Technology Data Exchange (ETDEWEB)

    Wakizaka, A.; Nishizawa, Y.; Aiba, N.; Okuhara, E.; Takahashi, S.


    A simple enzyme immunoassay procedure was developed for the quantitative determination of 254-nm uv-induced DNA damage in cells. With the use of specific antibodies to uv-irradiated DNA and horseradish peroxidase-conjugated antibody to rabbit IgG, the extent of damaged DNA in uv-irradiated rat spleen mononuclear cells was quantitatively measurable. Through the use of this method, the amount of damaged DNA present in 2 X 10(5) cells irradiated at a dose of 75 J/m2 was estimated to be 7 ng equivalents of the standard uv-irradiated DNA. In addition, when the cells, irradiated at 750 J/m2, were incubated for 1 h, the antigenic activity of DNA decreased by 40%, suggesting that a repair of the damaged sites in DNA had proceeded to some extent in the cells.

  5. Quantitative assessment of parkinsonian bradykinesia based on an inertial measurement unit. (United States)

    Dai, Houde; Lin, Haijun; Lueth, Tim C


    As the most characteristic feature of Parkinson's disease (PD), bradykinesia (slowness of movement) affects all patients with Parkinson's disease and interferes with their daily activities. This study introduces a wearable bradykinesia assessment system whose core component is composed of an inertial measurement unit. The system diagram and assessment task were defined in accordance with clinical requirements from neurologists. Based on hand grasping actions, calculations of hand grasping ranges and statistical methods of quantitatively assessing parkinsonian bradykinesia were presented. Seven control subjects and eight patients were tested with this system. Experimental results show that a calculated bradykinesia parameter (modified mean range, instead of mean and standard deviation of the grasp ranges) correlated well with the evaluations of a neurologist (Pearson's correlation coefficient r = -0.83, p inertial sensors for quantitative assessment of motor symptoms during treatment.

  6. Measuring factors affecting implementation of health innovations: a systematic review of structural, organizational, provider, patient, and innovation level measures. (United States)

    Chaudoir, Stephenie R; Dugan, Alicia G; Barr, Colin H I


    Two of the current methodological barriers to implementation science efforts are the lack of agreement regarding constructs hypothesized to affect implementation success and identifiable measures of these constructs. In order to address these gaps, the main goals of this paper were to identify a multi-level framework that captures the predominant factors that impact implementation outcomes, conduct a systematic review of available measures assessing constructs subsumed within these primary factors, and determine the criterion validity of these measures in the search articles. We conducted a systematic literature review to identify articles reporting the use or development of measures designed to assess constructs that predict the implementation of evidence-based health innovations. Articles published through 12 August 2012 were identified through MEDLINE, CINAHL, PsycINFO and the journal Implementation Science. We then utilized a modified five-factor framework in order to code whether each measure contained items that assess constructs representing structural, organizational, provider, patient, and innovation level factors. Further, we coded the criterion validity of each measure within the search articles obtained. Our review identified 62 measures. Results indicate that organization, provider, and innovation-level constructs have the greatest number of measures available for use, whereas structural and patient-level constructs have the least. Additionally, relatively few measures demonstrated criterion validity, or reliable association with an implementation outcome (e.g., fidelity). In light of these findings, our discussion centers on strategies that researchers can utilize in order to identify, adapt, and improve extant measures for use in their own implementation research. In total, our literature review and resulting measures compendium increases the capacity of researchers to conceptualize and measure implementation-related constructs in their ongoing and

  7. Measurement error of a simplified protocol for quantitative sensory tests in chronic pain patients

    DEFF Research Database (Denmark)

    Müller, Monika; Biurrun Manresa, José; Limacher, Andreas


    clinical setting. METHODS: We calculated intraclass correlation coefficients and performed a Bland-Altman analysis. RESULTS: Intraclass correlation coefficients were all clearly greater than 0.75, and Bland-Altman analysis showed minute systematic errors with small point estimates and narrow 95% confidence......BACKGROUND AND OBJECTIVES: Large-scale application of Quantitative Sensory Tests (QST) is impaired by lacking standardized testing protocols. One unclear methodological aspect is the number of records needed to minimize measurement error. Traditionally, measurements are repeated 3 to 5 times...... measurement error and number of records. We determined the measurement error of a single versus the mean of 3 records of pressure pain detection threshold (PPDT), electrical pain detection threshold (EPDT), and nociceptive withdrawal reflex threshold (NWRT) in 429 chronic pain patients recruited in a routine...

  8. A systematic review of the extent and measurement of healthcare provider racism. (United States)

    Paradies, Yin; Truong, Mandy; Priest, Naomi


    Although considered a key driver of racial disparities in healthcare, relatively little is known about the extent of interpersonal racism perpetrated by healthcare providers, nor is there a good understanding of how best to measure such racism. This paper reviews worldwide evidence (from 1995 onwards) for racism among healthcare providers; as well as comparing existing measurement approaches to emerging best practice, it focuses on the assessment of interpersonal racism, rather than internalized or systemic/institutional racism. The following databases and electronic journal collections were searched for articles published between 1995 and 2012: Medline, CINAHL, PsycInfo, Sociological Abstracts. Included studies were published empirical studies of any design measuring and/or reporting on healthcare provider racism in the English language. Data on study design and objectives; method of measurement, constructs measured, type of tool; study population and healthcare setting; country and language of study; and study outcomes were extracted from each study. The 37 studies included in this review were almost solely conducted in the U.S. and with physicians. Statistically significant evidence of racist beliefs, emotions or practices among healthcare providers in relation to minority groups was evident in 26 of these studies. Although a number of measurement approaches were utilized, a limited range of constructs was assessed. Despite burgeoning interest in racism as a contributor to racial disparities in healthcare, we still know little about the extent of healthcare provider racism or how best to measure it. Studies using more sophisticated approaches to assess healthcare provider racism are required to inform interventions aimed at reducing racial disparities in health.

  9. Quantitative measurement of out-of-plan deformation generated at the around defect of pressure vessel using shearography

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyoung Suk; Beak, Sang Kyu; Lee, Gun Jung; Chang, Ho Seob [Chosun University, Kwangju (Korea, Republic of); Kang, Myoung Goo [Chosun University RRC, Kwangju (Korea, Republic of); Kim, Sung Sik [Mokpo Science College, Mokpo(Korea, Republic of)


    Shearography, one of NDT methods without contact, is able to inspect defects of pipelines and pressure vessels that are used in the industrial machine and nuclear power plants and is used to determine safety, maintenance, and mending. Electronic Speckle Pattern Interferometry(ESPI) is a common method for measuring out-of-plane deformation and in-plane deformation and applied for vibration analysis and strain/stress analysis. However, ESPI is sensitive to environmental disturbance, which provide the limitation of industrial application. On the other hand, Shearography based on shearing interferometer which is insensitive to vibration disturbance can directly measure the first derivative of out-of-plane deformation. In this paper a technique that extract out-of-plane deformation from results of shearography by numerical processing is proposed and measurement results of ESPI and Shearoraphy are compared quantitative to inspect defects of pipelines and pressure vessels.

  10. Provider performance measures in private and public programs: achieving meaningful alignment with flexibility to innovate. (United States)

    Higgins, Aparna; Veselovskiy, German; McKown, Lauren


    In recent years there has been a significant expansion in the use of provider performance measures for quality improvement, payment, and public reporting. Using data from a survey of health plans, we characterize the use of such performance measures by private payers. We also compare the use of these measures among selected private and public programs. We studied twenty-three health plans with 121 million commercial enrollees--66 percent of the national commercial enrollment. The health plans reported using 546 distinct performance measures. There was much variation in the use of performance measures in both private and public payment and care delivery programs, despite common areas of focus that included cardiovascular conditions, diabetes, and preventive services. We conclude that policy makers and stakeholders who seek less variability in the use of performance measures to increase consistency should balance this goal with the need for flexibility to meet the needs of specific populations and promote innovation.

  11. Quantitative lymphoscintigraphy in post-mastectomy lymphedema: correlation with circumferential measurements

    Energy Technology Data Exchange (ETDEWEB)

    Choi, Joon Young; Lee, Kyung Han; Kim, Sang Eun; Kim, Byung Tae; Hwang, Jee Hea; Lee, Byung Boong [Samsung Medical Center, Seoul (Korea, Republic of)


    An objective measure for the severity and progression is important for the management of lymphedema. To evaluate the usefulness of lympho-scintigraphy in this regard, we compared various quantitative indices from upper extremity lymphoscintigraphy with circumferential measurements, before and after physiotheraphy. Upper extremity lymphoscintigraphy was performed in 38 patients with unilateral postmastectomy lymphedema. Tc-99m antimony sulfide colloid (37 MBq) was injected s.c. into the second and third interdigital spaces. The injection sites were imaged immediately after injection. After standardized exercise for 15 min, upper extremity images were acquired 30 min, 1 hr and 2 hr after injection. The clearance of the injection site (CL), and % uptake in regional lymph nodes (%LN) and soft tissue of the extremity (i.e., the degree of dermal backflow) (%EXT) compared to the initial injection site were calculated. Circumference of each extremity was measured at 7 levels; the severity of lymphedema was expressed as the percentage difference of total circumferential difference (TCD) between healthy and edematous extremities compared to the total circumference of healthy extremity (%TCD). In 19 patients who received physiotherapy, the therapeutic effect was measured by % decrease of TCD (%DTCD) before and after therapy (Raines. et al., 1977). The quantitative indices calculated in the image at 2 hr p.i. had better correlation with either %TCD or %DTCD than those from earlier images (Table). The CL, %LN and %EXT of edematous extremity had a significant correlation with TCD. The %EXT was correlated best with either TCD or %DTCD. The results suggest that the %EXT which corresponds to the degree of dermal backflow may be a simple and useful quantitative index for evaluating the severity and progression in lymphedema and predicting the effect of therapy.

  12. Quantitative measurement of rubidium isotope ratio using forward degenerate four-wave mixing

    Energy Technology Data Exchange (ETDEWEB)

    Cheng Xuemei [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); Ren Zhaoyu, E-mail: [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); Wang Jian; Miao Yizhu [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); Xu Xinlong [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); Beijing National Laboratory for Condensed Matter Physics, and Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Jia Lajiang [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); Fan Haiming, E-mail: [State Key Lab Incubation Base of Photoelectric Technology and Functional Materials, National Photoelectric Technology, and Functional Materials and Application of Science and Technology International Cooperation Center, Northwest University, Xi' an 710069 (China); School of Physics, National University of Ireland Galway (NUIG), Galway (Ireland); and others


    In the present study, forward degenerate four-wave mixing (FDFWM) is employed to measure rubidium (Rb) isotope ratio quantitatively with excellent reproducibility regardless of laser intensity turbulence. The effects of power saturation, atomic absorption and Doppler broadening on measurements are investigated. The results indicate that optimized pump power for isotope ratio measurement is 5-37.3 mW and the optimized atomic number density is around 10{sup 14} m{sup -3} for the sample cell with a length of 50 mm. In addition, the signal of FDFWM is almost independent on Doppler effect in isotope ratio determination. The measured {sup 85}Rb and {sup 87}Rb ratios in Rb vapor cell and RbCl are 2.590 {+-} 0.001 and 2.649 {+-} 0.002 respectively, which are in good agreement with the values obtained by absorption spectroscopy and mass spectrometry. A low detection limit as 18.41 fg/mL is achieved. The information obtained from this work suggests that FDFWM is a reliable laser spectroscopic technique in quantitative isotope trace analysis for various applications such as geological and archeological dating. - Highlights: Black-Right-Pointing-Pointer Rb isotope ratio was quantitatively determined with DFWM for the first time. Black-Right-Pointing-Pointer Saturation effect and atomic absorption were studied to optimize the parameters. Black-Right-Pointing-Pointer High resolution was realized in graphite furnace with high temperature of 2000 Degree-Sign C. Black-Right-Pointing-Pointer Detection limit as low as 18.41 fg/mL was achieved.

  13. A pre-sample charge measurement system for quantitative NMP-analysis

    Energy Technology Data Exchange (ETDEWEB)

    Kristiansson, P., E-mail: [Division of Nuclear Physics, Department of Physics, Lund University, Box 118, SE-221 00 Lund (Sweden); Borysiuk, M.; Arteaga-Marrero, N.; Elfman, M.; Nilsson, E.J.C.; Nilsson, C.; Pallon, J. [Division of Nuclear Physics, Department of Physics, Lund University, Box 118, SE-221 00 Lund (Sweden)


    In many IBA applications the main aim is to obtain quantitative figures characterizing the sample. Normally charge, i.e. number of probe particles, is used for normalization and is measured either by collecting the charge deposited in the sample or by collecting the particle in a post-sample Faraday cup or in combination. Both these techniques have drawbacks and results can be difficult to compare for samples with different matrix composition. In this work, we present an upgraded design and test results from the Lund NMP pre-sample charge measurement system. The system presented is based on a pre-sample beam deflection controlled by the beam scanning system for the nuclear microprobe. It can be operated in different modes, but during normal operation the beam is blanked once per pixel and the corresponding charge is collected during the beam-off period. The system does not only measure an average of the beam current during data collection, but actually a pixel-by-pixel normalization is possible. Data of the system performance are presented and in addition illustrations of how quantitative measurements both for PIXE and elastic scattering can be made more reliable.

  14. Quantitative quality measure based on light wave distribution to access 3D display (United States)

    Sakamoto, Yuji; Okuyama, Fumio


    There are a lot of three-dimensional (3D) displaying methods such as stereoscopy, integral photography, holography, etc. These technologies have different 3D vision properties and 3D image qualities. Conventionally, biological responsiveness is measured by using an actual 3D display in order to evaluate image qualities of 3D displaying method. It is required quantitative quality measure for 3D images for quantitative evaluation, which are useful for comparing 3D image quality and a design of a new display system. In this paper, we propose quality measures for 3D images named volume signal to noise ratio (VSNR), which is a three-dimensionally extended signal to noise ratio (SNR). A 3D display produces light wave distributions in 3D space, which makes observers view 3D image illusions. The VSNR measures error of light wave distributions between generated by actual objects and produced by a 3D display. The light wave distribution is including various factors for 3D perception of human such as resolution of reconstructed images, visual fields, motion parallax, and depth of field. The VSNR evaluates these 3D perception factors totally. We were carried out the experiments to certificate the efficiency of the VSNR. 3D images represented electro-holographic display and integral photographic displays were evaluated by the VSNR. The results indicated that the electro-holographic display has better quality than integral photographic display, but speckle noise deteriorates the 3D image quality.

  15. Measuring Provider Performance for Physicians Participating in the Merit-Based Incentive Payment System. (United States)

    Squitieri, Lee; Chung, Kevin C


    In 2017, the Centers for Medicare and Medicaid Services began requiring all eligible providers to participate in the Quality Payment Program or face financial reimbursement penalty. The Quality Payment Program outlines two paths for provider participation: the Merit-Based Incentive Payment System and Advanced Alternative Payment Models. For the first performance period beginning in January of 2017, the Centers for Medicare and Medicaid Services estimates that approximately 83 to 90 percent of eligible providers will not qualify for participation in an Advanced Alternative Payment Model and therefore must participate in the Merit-Based Incentive Payment System program. The Merit-Based Incentive Payment System path replaces existing quality-reporting programs and adds several new measures to evaluate providers using four categories of data: (1) quality, (2) cost/resource use, (3) improvement activities, and (4) advancing care information. These categories will be combined to calculate a weighted composite score for each provider or provider group. Composite Merit-Based Incentive Payment System scores based on 2017 performance data will be used to adjust reimbursed payment in 2019. In this article, the authors provide relevant background for understanding value-based provider performance measurement. The authors also discuss Merit-Based Incentive Payment System reporting requirements and scoring methodology to provide plastic surgeons with the necessary information to critically evaluate their own practice capabilities in the context of current performance metrics under the Quality Payment Program.

  16. Quantitative measurement of motor symptoms in Parkinson's disease: a study with full-body motion capture data. (United States)

    Das, Samarjit; Trutoiu, Laura; Murai, Akihiko; Alcindor, Dunbar; Oh, Michael; De la Torre, Fernando; Hodgins, Jessica


    Recent advancements in the portability and affordability of optical motion capture systems have opened the doors to various clinical applications. In this paper, we look into the potential use of motion capture data for the quantitative analysis of motor symptoms in Parkinson's Disease (PD). The standard of care, human observer-based assessments of the motor symptoms, can be very subjective and are often inadequate for tracking mild symptoms. Motion capture systems, on the other hand, can potentially provide more objective and quantitative assessments. In this pilot study, we perform full-body motion capture of Parkinson's patients with deep brain stimulator off-drugs and with stimulators on and off. Our experimental results indicate that the quantitative measure on spatio-temporal statistics learnt from the motion capture data reveal distinctive differences between mild and severe symptoms. We used a Support Vector Machine (SVM) classifier for discriminating mild vs. severe symptoms with an average accuracy of approximately 90%. Finally, we conclude that motion capture technology could potentially be an accurate, reliable and effective tool for statistical data mining on motor symptoms related to PD. This would enable us to devise more effective ways to track the progression of neurodegenerative movement disorders.

  17. Response distortion in personality measurement: born to deceive, yet capable of providing valid self-assessments?

    Directory of Open Access Journals (Sweden)



    Full Text Available This introductory article to the special issue of Psychology Science devoted to the subject of “Considering Response Distortion in Personality Measurement for Industrial, Work and Organizational Psychology Research and Practice” presents an overview of the issues of response distortion in personality measurement. It also provides a summary of the other articles published as part of this special issue addressing social desirability, impression management, self-presentation, response distortion, and faking in personality measurement in industrial, work, and organizational settings.

  18. Quantitative computed tomography measurements of emphysema for diagnosing asthma-chronic obstructive pulmonary disease overlap syndrome. (United States)

    Xie, Mengshuang; Wang, Wei; Dou, Shuang; Cui, Liwei; Xiao, Wei


    The diagnostic criteria of asthma-COPD overlap syndrome (ACOS) are controversial. Emphysema is characteristic of COPD and usually does not exist in typical asthma patients. Emphysema in patients with asthma suggests the coexistence of COPD. Quantitative computed tomography (CT) allows repeated evaluation of emphysema noninvasively. We investigated the value of quantitative CT measurements of emphysema in the diagnosis of ACOS. This study included 404 participants; 151 asthma patients, 125 COPD patients, and 128 normal control subjects. All the participants underwent pulmonary function tests and a high-resolution CT scan. Emphysema measurements were taken with an Airway Inspector software. The asthma patients were divided into high and low emphysema index (EI) groups based on the percentage of low attenuation areas less than -950 Hounsfield units. The characteristics of asthma patients with high EI were compared with those having low EI or COPD. The normal value of percentage of low attenuation areas less than -950 Hounsfield units in Chinese aged >40 years was 2.79%±2.37%. COPD patients indicated more severe emphysema and more upper-zone-predominant distribution of emphysema than asthma patients or controls. Thirty-two (21.2%) of the 151 asthma patients had high EI. Compared with asthma patients with low EI, those with high EI were significantly older, more likely to be male, had more pack-years of smoking, had more upper-zone-predominant distribution of emphysema, and had greater airflow limitation. There were no significant differences in sex ratios, pack-years of smoking, airflow limitation, or emphysema distribution between asthma patients with high EI and COPD patients. A greater number of acute exacerbations were seen in asthma patients with high EI compared with those with low EI or COPD. Asthma patients with high EI fulfill the features of ACOS, as described in the Global Initiative for Asthma and Global Initiative for Chronic Obstructive Lung Disease

  19. Quantitative Micro-Raman Spectroscopy for Partial Pressure Measurement in Small Volumes. (United States)

    Karlen, Sylvain; Gobet, Jean; Overstolz, Thomas; Haesler, Jacques; Lecomte, Steve


    We demonstrate the quantitative capabilities of Raman confocal microscopy as a nondestructive method to measure the partial pressure of molecular gases in mm3 range sealed volume having an optical access. Thanks to a calibration procedure, we apply this technique for the characterization of the absolute nitrogen partial pressure inside buffered micro electromechanical system (MEMS) atomic vapor cells developed for atomic clocks. Our results are compared with measurements obtained by rubidium hyperfine frequency spectroscopy and a good agreement is demonstrated between the two methods, with a three-sigma detection limit below 10 mbar for a 1 h integration time, using a 33 mW 532 nm excitation laser. These results prove the potential of confocal micro-Raman spectroscopy as a simple and nondestructive method for small-scale pressure measurements.

  20. Quantitative measurement and visualization of biofilm O 2 consumption rates in membrane filtration systems

    KAUST Repository

    Prest, Emmanuelle I E C


    There is a strong need for techniques enabling direct assessment of biological activity of biofouling in membrane filtration systems. Here we present a new quantitative and non-destructive method for mapping O 2 dynamics in biofilms during biofouling studies in membrane fouling simulators (MFS). Transparent planar O 2 optodes in combination with a luminescence lifetime imaging system were used to map the two-dimensional distribution of O 2 concentrations and consumption rates inside the MFS. The O 2 distribution was indicative for biofilm development. Biofilm activity was characterized by imaging of O 2 consumption rates, where low and high activity areas could be clearly distinguished. The spatial development of O 2 consumption rates, flow channels and stagnant areas could be determined. This can be used for studies on concentration polarization, i.e. salt accumulation at the membrane surface resulting in increased salt passage and reduced water flux. The new optode-based O 2 imaging technique applied to MFS allows non-destructive and spatially resolved quantitative biological activity measurements (BAM) for on-site biofouling diagnosis and laboratory studies. The following set of complementary tools is now available to study development and control of biofouling in membrane systems: (i) MFS, (ii) sensitive pressure drop measurement, (iii) magnetic resonance imaging, (iv) numerical modelling, and (v) biological activity measurement based on O 2 imaging methodology. © 2011 Elsevier B.V.

  1. Rapid and quantitative measuring of telomerase activity using an electrochemiluminescent sensor (United States)

    Zhou, Xiaoming; Xing, Da; Zhu, Debin; Jia, Li


    Telomerase, a ribonucleoprotein enzyme that adds telomeric repeats to the 3'end of chromosomal DNA for maintaining chromosomal integrity and stability. This strong association of telomerase activity with tumors establishing it is the most widespread cancer marker. A number of assays based on the polymerase chain reaction (PCR) have been developed for the evaluation of telomerase activity. However, those methods require gel electrophoresis and some staining procedures. We developed an electrochemiluminescent (ECL) sensor for the measuring of telomerase activity to overcome these problems such as troublesome post-PCR procedures and semi-quantitative assessment in the conventional method. In this assay 5'-biotinylated telomerase synthesis (TS) primer serve as the substrate for the extension of telomeric repeats under telomerase. The extension products were amplified with this TS primer and a tris-(2'2'-bipyridyl) ruthenium (TBR)-labeled reversed primer. The amplified products was separated and enriched in the surface of electrode by streptavidin-coated magnetic beads, and detected by measuring the ECL signals of the TBR labeled. Measuring telomerase activity use the sensor is easy, sensitive, rapid, and applicable to quantitative analysis, should be clinically useful for the detection and monitoring of telomerase activity.

  2. Effect of wavefront divergence in the quantitative measurement analysis of electronic speckle pattern shearing interferometry (ESPSI) (United States)

    Wan Abdullah, W. S.; Petzing, Jon N.; Tyrer, John R.


    ESPSI or shearography has been successfully used in non-destructive testing (NDT) for measuring the derivative out-of-plane displacement, w/x and/or w/y, and recently a few investigations of derivative in-plain displacement, u/x, v/y, u/y and v/x have been reported. The demand of quantitative measurement has encouraged manufacturers to produce a quantitative shearography system. However, errors arising from numerous sources, including wavefront divergence and object geometry are not taken into account when calculating the interferometer fringe function and quantifying the data. In this paper the novel approach in quantified error that propagates from the divergence illumination wavefront is presented. The theoretical error is formulated by means of mathematical approach that comprises of three dependent variables, the inspected object distance, the object size (field area covered by the CCD camera) and the illumination angle. The error defined by the difference of phase data using divergence illumination object wavefront compared to phase data that is measured by using collimated illumination wavefront. Theoretical analysis and experimental validation indicates that the magnitude of the maximum phase change difference due to the divergence of illumination wavefront to exceed 10% for out-of-plane and 40% for in-plane analysis.

  3. Validation of a Spectral Method for Quantitative Measurement of Color in Protein Drug Solutions. (United States)

    Yin, Jian; Swartz, Trevor E; Zhang, Jian; Patapoff, Thomas W; Chen, Bartolo; Marhoul, Joseph; Shih, Norman; Kabakoff, Bruce; Rahimi, Kimia


    A quantitative spectral method has been developed to precisely measure the color of protein solutions. In this method, a spectrophotometer is utilized for capturing the visible absorption spectrum of a protein solution, which can then be converted to color values (L*a*b*) that represent human perception of color in a quantitative three-dimensional space. These quantitative values (L*a*b*) allow for calculating the best match of a sample's color to a European Pharmacopoeia reference color solution. In order to qualify this instrument and assay for use in clinical quality control, a technical assessment was conducted to evaluate the assay suitability and precision. Setting acceptance criteria for this study required development and implementation of a unique statistical method for assessing precision in 3-dimensional space. Different instruments, cuvettes, protein solutions, and analysts were compared in this study. The instrument accuracy, repeatability, and assay precision were determined. The instrument and assay are found suitable for use in assessing color of drug substances and drug products and is comparable to the current European Pharmacopoeia visual assessment method. In the biotechnology industry, a visual assessment is the most commonly used method for color characterization, batch release, and stability testing of liquid protein drug solutions. Using this method, an analyst visually determines the color of the sample by choosing the closest match to a standard color series. This visual method can be subjective because it requires an analyst to make a judgment of the best match of color of the sample to the standard color series, and it does not capture data on hue and chroma that would allow for improved product characterization and the ability to detect subtle differences between samples. To overcome these challenges, we developed a quantitative spectral method for color determination that greatly reduces the variability in measuring color and allows

  4. Quantitative measurement of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy. (United States)

    Choi, Hyunwoo; Hong, Seungbum; No, Kwangsoo


    A simple quantitative measurement procedure of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy is presented. This technique enables one to determine the corresponding lateral inverse optical lever sensitivity (LIOLS) of the cantilever on the given sample. Piezoelectric coefficient, d(31) of BaTiO(3) single crystal (-81.62 ± 40.22 pm/V) which was calculated using the estimated LIOLS was in good agreement with the reported value in literature. © 2011 American Institute of Physics

  5. Quantitative flow measurement after placing a flow diverter for a distal internal carotid artery aneurysm. (United States)

    Chen, Chien-Wei; Wong, Ho-Fai; Ye, Yu-Ling; Chen, Yao-Liang; Chen, Wei-Liang; Ou, Chang-Hsien; Tsai, Yuan-Hsiung


    To evaluate the differences in arterial flow after flow diverter placement using quantitative flow measurements based on digital subtraction angiography (DSA). Between November 2013 and November 2015, all patients who had flow diverters placed for distal internal carotid artery (ICA) aneurysms were reviewed. Patients in whom the stent was placed across the ostia of the ophthalmic artery (OphA) and anterior choroidal artery (AChA) were enrolled. Five regions of interest were selected: the proximal ICA (as a reference), terminal ICA, middle cerebral artery (MCA), anterior cerebral artery (ACA), OphA, and AChA. The values of the peak, time-to-peak (TTP), and area under the curve (AUC) were analyzed using a quantitative DSA technique. The study enrolled 13 patients. The quantitative flow analysis showed improved flow in the terminal ICA (peak and AUC, p=0.036 and p=0.04, respectively), MCA (AUC, p=0.023), and ACA (AUC, p=0.006), and decreased flow in the OphA (peak and AUC, p=0.013 and p=0.005, respectively) and AChA (peak and subtracted TTP, p=0.023 and p=0.050, respectively) after flow diverter placement. Larger aneurysm volume was significantly correlated with decreased OphA flow after the procedure (peak and AUC, p=0.049 and p=0.037, respectively). Larger aneurysm volume also had a marginal correlation with increased distal ICA flow after the procedure, but this did not reach significance (peak and AUC, p=0.195 and p=0.060, respectively). Without using extra contrast medium or radiation dosages, color-coded DSA enables quantitative monitoring of the cerebral circulation after flow-diverting treatment. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to

  6. Quantitative autistic trait measurements index background genetic risk for ASD in Hispanic families. (United States)

    Page, Joshua; Constantino, John Nicholas; Zambrana, Katherine; Martin, Eden; Tunc, Ilker; Zhang, Yi; Abbacchi, Anna; Messinger, Daniel


    Recent studies have indicated that quantitative autistic traits (QATs) of parents reflect inherited liabilities that may index background genetic risk for clinical autism spectrum disorder (ASD) in their offspring. Moreover, preferential mating for QATs has been observed as a potential factor in concentrating autistic liabilities in some families across generations. Heretofore, intergenerational studies of QATs have focused almost exclusively on Caucasian populations-the present study explored these phenomena in a well-characterized Hispanic population. The present study examined QAT scores in siblings and parents of 83 Hispanic probands meeting research diagnostic criteria for ASD, and 64 non-ASD controls, using the Social Responsiveness Scale-2 (SRS-2). Ancestry of the probands was characterized by genotype, using information from 541,929 single nucleotide polymorphic markers. In families of Hispanic children with an ASD diagnosis, the pattern of quantitative trait correlations observed between ASD-affected children and their first-degree relatives (ICCs on the order of 0.20), between unaffected first-degree relatives in ASD-affected families (sibling/mother ICC = 0.36; sibling/father ICC = 0.53), and between spouses (mother/father ICC = 0.48) were in keeping with the influence of transmitted background genetic risk and strong preferential mating for variation in quantitative autistic trait burden. Results from analysis of ancestry-informative genetic markers among probands in this sample were consistent with that from other Hispanic populations. Quantitative autistic traits represent measurable indices of inherited liability to ASD in Hispanic families. The accumulation of autistic traits occurs within generations, between spouses, and across generations, among Hispanic families affected by ASD. The occurrence of preferential mating for QATs-the magnitude of which may vary across cultures-constitutes a mechanism by which background genetic liability

  7. Provider report of the existence of detection and care of perinatal depression: quantitative evidence from public obstetric units in Mexico

    Directory of Open Access Journals (Sweden)

    Filipa de Castro


    Full Text Available Objective. To provide evidence on perinatal mental healthcare in Mexico. Materials and methods. Descriptive and bivariate analyses of data from a cross-sectional probabilistic survey of 211 public obstetric units. Results. Over half (64.0% of units offer mental healthcare; fewer offer perinatal depression (PND detection (37.1% and care (40.3%. More units had protocols/guidelines for PND detection and for care, respectively, in Mexico City-Mexico state (76.7%; 78.1% than in Southern (26.5%; 36.4%, Northern (27.3%; 28.1% and Central Mexico (50.0%; 52.7%. Conclusion. Protocols and provider training in PND, implementation of brief screening tools and psychosocial interventions delivered by non-clinical personnel are needed.      DOI:

  8. The increased sensitivity of human cytomegalovirus (HCMV) PCR quantitation in whole blood affects reproductive rate (Ro) measurement. (United States)

    Gurtler, Volker; Mayall, Barrie C; Wang, Jenny; Ghaly-Derias, Shahbano


    In order to determine the effect of the increase in sensitivity of HCMV detection in whole blood compared to plasma on reproductive rate (Ro) measurement, an optimized human cytomegalovirus (HCMV) quantitative PCR assay was developed. The results presented in this study are summarized by the following three methodological improvements: (i) at values below the limit of quantitation (LOQ) of 60copies/ml, determination of HCMV load was more sensitive with whole blood than plasma, (ii) for the determination of viral load, whole blood was more sensitive than plasma below 1000copies/ml but little difference was observed above 1000copies/ml and (iii) the measurement of "Reproductive Rate" can be affected by imprecise measurement of HCMV viral load in either plasma or whole blood compartments depending on whether samples were taken from patients on antiviral treatment or from patients where HCMV load was rising. Taken together this study provides methodological improvements suggesting that below HCMV viral load levels of 1000copies/ml (1640IU/ml) both plasma and whole blood should be tested. Crown Copyright © 2013. Published by Elsevier B.V. All rights reserved.

  9. A device for in vivo measurements of quantitative ultrasound variables at the human proximal femur. (United States)

    Barkmann, Reinhard; Laugier, Pascal; Moser, Urs; Dencks, Stefanie; Klausner, Michael; Padilla, Frédéric; Haïat, Guilleaume; Glüer, Claus-C


    Quantitative ultrasound (QUS) at the calcaneus has similar power as a bone mineral density (BMD)- measurement using DXA for the prediction of osteoporotic fracture risk. Ultrasound equipment is less expensive than DXA and free of ionizing radiation. As a mechanical wave, QUS has the potential of measuring different bone properties than dual X-ray absorptiometry (DXA,) which depends on X-ray attenuation and might be developed into a tool of comprehensive assessment of bone strength. However, site-specific DXA at the proximal femur shows best performance in the prediction of hip fractures. To combine the potential of QUS with measurements directly at the femur, we developed a device for in vivo QUS measurements at this site. Methods comprise ultrasound transmission through the bone, reflection from the bone surface, and backscatter from the inner trabecular structure. The complete area of the proximal femur can be scanned except at the femoral head, which interferes with the ilium. To avoid edge artifacts, a subregion of the proximal femur in the trochanteric region was selected as measurement region. First, in vivo measurements demonstrate a good signal to noise ratio and proper depiction of the proximal femur on an attenuation image. Our results demonstrate the feasibility of in vivo measurements. Further improvements can be expected by refinement of the scanning technique and data evaluation method to enhance the potential of the new method for the estimation of bone strength.

  10. Selecting quantitative water management measures at the river basin scale in a global change context (United States)

    Girard, Corentin; Rinaudo, Jean-Daniel; Caballero, Yvan; Pulido-Velazquez, Manuel


    One of the main challenges in the implementation of the Water Framework Directive (WFD) in the European Union is the definition of programme of measures to reach the good status of the European water bodies. In areas where water scarcity is an issue, one of these challenges is the selection of water conservation and capacity expansion measures to ensure minimum environmental in-stream flow requirements. At the same time, the WFD calls for the use of economic analysis to identify the most cost-effective combination of measures at the river basin scale to achieve its objective. With this respect, hydro-economic river basin models, by integrating economics, environmental and hydrological aspects at the river basin scale in a consistent framework, represent a promising approach. This article presents a least-cost river basin optimization model (LCRBOM) that selects the combination of quantitative water management measures to meet environmental flows for future scenarios of agricultural and urban demand taken into account the impact of the climate change. The model has been implemented in a case study on a Mediterranean basin in the south of France, the Orb River basin. The water basin has been identified as in need for quantitative water management measures in order to reach the good status of its water bodies. The LCRBOM has been developed using GAMS, applying Mixed Integer Linear Programming. It is run to select the set of measures that minimizes the total annualized cost of the applied measures, while meeting the demands and minimum in-stream flow constraints. For the economic analysis, the programme of measures is composed of water conservation measures on agricultural and urban water demands. It compares them with measures mobilizing new water resources coming from groundwater, inter-basin transfers and improvement in reservoir operating rules. The total annual cost of each measure is calculated for each demand unit considering operation, maintenance and

  11. Quantitative facial asymmetry: using three-dimensional photogrammetry to measure baseline facial surface symmetry. (United States)

    Taylor, Helena O; Morrison, Clinton S; Linden, Olivia; Phillips, Benjamin; Chang, Johnny; Byrne, Margaret E; Sullivan, Stephen R; Forrest, Christopher R


    Although symmetry is hailed as a fundamental goal of aesthetic and reconstructive surgery, our tools for measuring this outcome have been limited and subjective. With the advent of three-dimensional photogrammetry, surface geometry can be captured, manipulated, and measured quantitatively. Until now, few normative data existed with regard to facial surface symmetry. Here, we present a method for reproducibly calculating overall facial symmetry and present normative data on 100 subjects. We enrolled 100 volunteers who underwent three-dimensional photogrammetry of their faces in repose. We collected demographic data on age, sex, and race and subjectively scored facial symmetry. We calculated the root mean square deviation (RMSD) between the native and reflected faces, reflecting about a plane of maximum symmetry. We analyzed the interobserver reliability of the subjective assessment of facial asymmetry and the quantitative measurements and compared the subjective and objective values. We also classified areas of greatest asymmetry as localized to the upper, middle, or lower facial thirds. This cluster of normative data was compared with a group of patients with subtle but increasing amounts of facial asymmetry. We imaged 100 subjects by three-dimensional photogrammetry. There was a poor interobserver correlation between subjective assessments of asymmetry (r = 0.56). There was a high interobserver reliability for quantitative measurements of facial symmetry RMSD calculations (r = 0.91-0.95). The mean RMSD for this normative population was found to be 0.80 ± 0.24 mm. Areas of greatest asymmetry were distributed as follows: 10% upper facial third, 49% central facial third, and 41% lower facial third. Precise measurement permitted discrimination of subtle facial asymmetry within this normative group and distinguished norms from patients with subtle facial asymmetry, with placement of RMSDs along an asymmetry ruler. Facial surface symmetry, which is poorly assessed

  12. Spiritual care competence for contemporary nursing practice: A quantitative exploration of the guidance provided by fundamental nursing textbooks. (United States)

    Timmins, Fiona; Neill, Freda; Murphy, Maryanne; Begley, Thelma; Sheaf, Greg


    Spirituality is receiving unprecedented attention in the nursing literature. Both the volume and scope of literature on the topic is expanding, and it is clear that this topic is of interest to nurses. There is consensus that the spiritual required by clients receiving health ought to be an integrated effort across the health care team. Although undergraduate nurses receive some education on the topic, this is ad hoc and inconsistent across universities. Textbooks are clearly a key resource in this area however the extent to which they form a comprehensive guide for nursing students and nurses is unclear. This study provides a hitherto unperformed analysis of core nursing textbooks to ascertain spirituality related content. 543 books were examined and this provides a range of useful information about inclusions and omissions in this field. Findings revealed that spirituality is not strongly portrayed as a component of holistic care and specific direction for the provision of spiritual care is lacking. Fundamental textbooks used by nurses and nursing students ought to inform and guide integrated spiritual care and reflect a more holistic approach to nursing care. The religious and/or spiritual needs of an increasingly diverse community need to be taken seriously within scholarly texts so that this commitment to individual clients' needs can be mirrored in practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. The Korean American woman's face: anthropometric measurements and quantitative analysis of facial aesthetics. (United States)

    Choe, Kyle S; Sclafani, Anthony P; Litner, Jason A; Yu, Guo-Pei; Romo, Thomas


    To assess the differences in facial proportions between Korean American (KA) women and North American white (NAW) women and to quantitatively describe aesthetic facial features in the KA women. Anthropometric survey and facial aesthetic evaluation. Volunteer sample of KA women (n = 72) who served as models for part 1 of the study and a different sample of KA women (n = 5) and men (n = 5) who served as judges for part 2 of the study. All subjects were between ages 18 and 35 years and had Korean parents and no previous facial surgery or trauma. Intervention For part 1 of the study, standardized and referenced frontal and lateral photographs were taken of the models, and 26 standard anthropometric measurements were determined. Results were compared with published NAW standards. For part 2 of the study, 10 judges evaluated frontal views of the models for facial aesthetics using a visual analog scale. Quantitative analysis was done of the faces of attractive KA women (>90th percentile in aesthetic scores) and comparisons were made with the faces of NAW women and average KA women. The KA woman's face did not fit the neoclassical facial canons. Compared with NAW women, 24 of the 26 facial measurements in KA women were significantly different. Only 9 of the 26 facial measurements were significantly different when the attractive KA women were compared with the NAW women. Nine of the 17 nonsignificant facial measurements were very similar to those of the NAW women; many of these facial features centered around the midface. Although the average KA woman's facial anthropometric measurements were very different from those of the NAW woman, attractive KA women reflected many of the facial features of NAW women. These findings support the need for ethnically sensitive facial canons and further research into transcultural aesthetics.

  14. A quantitative tool for measuring the quality of medical training in emergency medicine. (United States)

    Smith, Simon M; Davis, Peyton; Davies, Llion


    The most common method of assessing the quality of medical education is through a selection of qualitative assessments, usually as part of a programme evaluation. Common qualitative assessments include measurements of students' and teachers' participation, outcome measures such as assessment results, and qualitative assessments such as interviews and questionnaires of students and teachers. Programme evaluation can therefore be a process that is both laborious and subject to accusations of a lack of objectivity. As a result, the development of a quantitative tool that could be used alongside a programme evaluation may be both useful and desirable. A pragmatic scoring system, utilizing routinely collected quantitative data, termed as the Quality Assessment Tool, was developed during the 2013 academic year within the setting of an Emergency Medicine training programme in the UK. This tool was tested against the standard assessment currently used for this programme to establish whether the quantitative tool correlated with the programme evaluation. Second, the individual items within the tool were investigated to identify any correlations with the current assessment of quality established by the programme evaluation. The Quality Assessment Tool appears to be correlated to the quality of training delivered at individual training sites in a single specialty. It certainly identifies those centres delivering the highest quality of training and also identifies those centres whose training is consistently of a lower standard. The assessment tool is less accurate at ranking those training centres whose training is merely 'satisfactory'; whether this is a result of the imprecision of the tool itself or a reflection of the subjective nature of the current assessment (i.e. whether the current evaluation system lacks validity) cannot be stated. In summary, it appears to be possible to use a single quantitative tool to reliably, and with validity, measure the quality of training

  15. Comparative measurement and quantitative risk assessment of alcohol consumption through wastewater-based epidemiology: An international study in 20 cities

    DEFF Research Database (Denmark)

    Ryu, Yeonsuk; Barceló, Damià; Barron, Leon P.


    Quantitative measurement of drug consumption biomarkers in wastewater can provide objective information on community drug use patterns and trends. This study presents the measurement of alcohol consumption in 20 cities across 11 countries through the use of wastewater-based epidemiology (WBE...... consumption biomarker, ethyl sulfate (EtS) was determined by liquid chromatography coupled to tandem mass spectrometry. The EtS concentrations were used for estimation of per capita alcohol consumption in each city, which was further compared with international reports and applied for risk assessment by MOE....... The average per capita consumption in 20 cities ranged between 6.4 and 44.3. L/day/1000 inhabitants. An increase in alcohol consumption during the weekend occurred in all cities, however the level of this increase was found to differ. In contrast to conventional data (sales statistics and interviews), WBE...

  16. HistoFlex-a microfluidic device providing uniform flow conditions enabling highly sensitive, reproducible and quantitative in situ hybridizations

    DEFF Research Database (Denmark)

    Søe, Martin Jensen; Okkels, Fridolin; Sabourin, David


    were not visually damaged during assaying, which enabled adapting a complete ISH assay for detection of microRNAs (miRNA). The effects of flow based incubations on hybridization, antibody incubation and Tyramide Signal Amplification (TSA) steps were investigated upon adapting the ISH assay...... for performing in the HistoFlex. The hybridization step was significantly enhanced using flow based incubations due to improved hybridization efficiency. The HistoFlex device enabled a fast miRNA ISH assay (3 hours) which provided higher hybridization signal intensity compared to using conventional techniques (5......A microfluidic device (the HistoFlex) designed to perform and monitor molecular biological assays under dynamic flow conditions on microscope slide-substrates, with special emphasis on analyzing histological tissue sections, is presented. Microscope slides were reversibly sealed onto a cast...

  17. Quantitative Electroencephalographic Analysis Provides an Early-Stage Indicator of Disease Onset and Progression in the zQ175 Knock-In Mouse Model of Huntington's Disease (United States)

    Fisher, Simon P.; Schwartz, Michael D.; Wurts-Black, Sarah; Thomas, Alexia M.; Chen, Tsui-Ming; Miller, Michael A.; Palmerston, Jeremiah B.; Kilduff, Thomas S.; Morairty, Stephen R.


    intervention and improve outcomes for patients with HD. Citation: Fisher SP, Schwartz MD, Wurts-Black S, Thomas AM, Chen TM, Miller MA, Palmerston JB, Kilduff TS, Morairty SR. Quantitative electroencephalographic analysis provides an early-stage indicator of disease onset and progression in the zQ175 knock-in mouse model of Huntington's disease. SLEEP 2016;39(2):379–391. PMID:26446107

  18. A device for rapid and quantitative measurement of cardiac myocyte contractility (United States)

    Gaitas, Angelo; Malhotra, Ricky; Li, Tao; Herron, Todd; Jalife, José


    Cardiac contractility is the hallmark of cardiac function and is a predictor of healthy or diseased cardiac muscle. Despite advancements over the last two decades, the techniques and tools available to cardiovascular scientists are limited in their utility to accurately and reliably measure the amplitude and frequency of cardiomyocyte contractions. Isometric force measurements in the past have entailed cumbersome attachment of isolated and permeabilized cardiomyocytes to a force transducer followed by measurements of sarcomere lengths under conditions of submaximal and maximal Ca2+ activation. These techniques have the inherent disadvantages of being labor intensive and costly. We have engineered a micro-machined cantilever sensor with an embedded deflection-sensing element that, in preliminary experiments, has demonstrated to reliably measure cardiac cell contractions in real-time. Here, we describe this new bioengineering tool with applicability in the cardiovascular research field to effectively and reliably measure cardiac cell contractility in a quantitative manner. We measured contractility in both primary neonatal rat heart cardiomyocyte monolayers that demonstrated a beat frequency of 3 Hz as well as human embryonic stem cell-derived cardiomyocytes with a contractile frequency of about 1 Hz. We also employed the β-adrenergic agonist isoproterenol (100 nmol l-1) and observed that our cantilever demonstrated high sensitivity in detecting subtle changes in both chronotropic and inotropic responses of monolayers. This report describes the utility of our micro-device in both basic cardiovascular research as well as in small molecule drug discovery to monitor cardiac cell contractions.

  19. Do Quantitative Measures of Research Productivity Correlate with Academic Rank in Oral and Maxillofacial Surgery? (United States)

    Susarla, Srinivas M; Dodson, Thomas B; Lopez, Joseph; Swanson, Edward W; Calotta, Nicholas; Peacock, Zachary S


    Academic promotion is linked to research productivity. The purpose of this study was to assess the correlation between quantitative measures of academic productivity and academic rank among academic oral and maxillofacial surgeons. This was a cross-sectional study of full-time academic oral and maxillofacial surgeons in the United States. The predictor variables were categorized as demographic (gender, medical degree, research doctorate, other advanced degree) and quantitative measures of academic productivity (total number of publications, total number of citations, maximum number of citations for a single article, I-10 index [number of publications with ≥ 10 citations], and h-index [number of publications h with ≥ h citations each]). The outcome variable was current academic rank (instructor, assistant professor, associate professor, professor, or endowed professor). Descriptive, bivariate, and multiple regression statistics were computed to evaluate associations between the predictors and academic rank. Receiver-operator characteristic curves were computed to identify thresholds for academic promotion. The sample consisted of 324 academic oral and maxillofacial surgeons, of whom 11.7% were female, 40% had medical degrees, and 8% had research doctorates. The h-index was the most strongly correlated with academic rank (ρ = 0.62, p research activity.

  20. Quantitative Conjugated Payload Measurement Using Enzymatic Release of Antibody-Drug Conjugate with Cleavable Linker. (United States)

    Rago, Brian; Tumey, L Nathan; Wei, Cong; Barletta, Frank; Clark, Tracey; Hansel, Steven; Han, Xiaogang


    As antibody-drug conjugate (ADC) design is evolving with novel payload, linker, and conjugation chemistry, the need for sensitive and precise quantitative measurement of conjugated payload to support pharmacokinetics (PK) is in high demand. Compared to ADCs containing noncleavable linkers, a strategy specific to linkers which are liable to pH, chemical reduction, or enzymatic cleavage has gained popularity in recent years. One bioanalytical approach to take advantage of this type of linker design is the development of a PK assay measuring released conjugated payload. For the ADC utilizing a dipeptide ValCit linker studied in this report, the release of payload PF-06380101 was achieved with high efficiency using a purified cathepsin B enzyme. The subsequent liquid chromatography mass spectrometry (LC/MS) quantitation leads to the PK profile of the conjugated payload. For this particular linker using a maleimide-based conjugation chemistry, one potential route of payload loss would result in an albumin adduct of the linker-payload. While this adduct's formation has been previously reported, here, for the first time, we have shown that payload from a source other than ADC contributes only up to 4% of total conjugated payload while it accounts for approximately 35% of payload lost from the ADC at 48 h after dosing to rats.

  1. Measuring the Nonuniform Evaporation Dynamics of Sprayed Sessile Microdroplets with Quantitative Phase Imaging. (United States)

    Edwards, Chris; Arbabi, Amir; Bhaduri, Basanta; Wang, Xiaozhen; Ganti, Raman; Yunker, Peter J; Yodh, Arjun G; Popescu, Gabriel; Goddard, Lynford L


    We demonstrate real-time quantitative phase imaging as a new optical approach for measuring the evaporation dynamics of sessile microdroplets. Quantitative phase images of various droplets were captured during evaporation. The images enabled us to generate time-resolved three-dimensional topographic profiles of droplet shape with nanometer accuracy and, without any assumptions about droplet geometry, to directly measure important physical parameters that characterize surface wetting processes. Specifically, the time-dependent variation of the droplet height, volume, contact radius, contact angle distribution along the droplet's perimeter, and mass flux density for two different surface preparations are reported. The studies clearly demonstrate three phases of evaporation reported previously: pinned, depinned, and drying modes; the studies also reveal instances of partial pinning. Finally, the apparatus is employed to investigate the cooperative evaporation of the sprayed droplets. We observe and explain the neighbor-induced reduction in evaporation rate, that is, as compared to predictions for isolated droplets. In the future, the new experimental methods should stimulate the exploration of colloidal particle dynamics on the gas-liquid-solid interface.

  2. Numerical analysis of quantitative measurement of hydroxyl radical concentration using laser-induced fluorescence in flame (United States)

    Shuang, Chen; Tie, Su; Yao-Bang, Zheng; Li, Chen; Ting-Xu, Liu; Ren-Bing, Li; Fu-Rong, Yang


    The aim of the present work is to quantitatively measure the hydroxyl radical concentration by using LIF (laser-induced fluorescence) in flame. The detailed physical models of spectral absorption lineshape broadening, collisional transition and quenching at elevated pressure are built. The fine energy level structure of the OH molecule is illustrated to understand the process with laser-induced fluorescence emission and others in the case without radiation, which include collisional quenching, rotational energy transfer (RET), and vibrational energy transfer (VET). Based on these, some numerical results are achieved by simulations in order to evaluate the fluorescence yield at elevated pressure. These results are useful for understanding the real physical processes in OH-LIF technique and finding a way to calibrate the signal for quantitative measurement of OH concentration in a practical combustor. Project supported by the National Natural Science Foundation of China (Grant No. 11272338) and the Fund from the Science and Technology on Scramjet Key Laboratory, China (Grant No. STSKFKT2013004).

  3. The ion microscope as a tool for quantitative measurements in the extreme ultraviolet (United States)

    Tsatrafyllis, N.; Bergues, B.; Schröder, H.; Veisz, L.; Skantzakis, E.; Gray, D.; Bodi, B.; Kuhn, S.; Tsakiris, G. D.; Charalambidis, D.; Tzallas, P.


    We demonstrate a tool for quantitative measurements in the extreme ultraviolet (EUV) spectral region measuring spatially resolved atomic ionization products at the focus of an EUV beam. The ionizing radiation is a comb of the 11th-15th harmonics of a Ti:Sapphire femtosecond laser beam produced in a Xenon gas jet. The spatial ion distribution at the focus of the harmonics is recorded using an ion microscope. Spatially resolved single- and two-photon ionization products of Argon and Helium are observed. From such ion distributions single- and two-photon generalized cross sections can be extracted by a self-calibrating method. The observation of spatially resolved two-EUV-photon ionization constitutes an initial step towards future single-shot temporal characterization of attosecond pulses.

  4. Airborne radar and radiometer experiment for quantitative remote measurements of rain (United States)

    Kozu, Toshiaki; Meneghini, Robert; Boncyk, Wayne; Wilheit, Thomas T.; Nakamura, Kenji


    An aircraft experiment has been conducted with a dual-frequency (10 GHz and 35 GHz) radar/radiometer system and an 18-GHz radiometer to test various rain-rate retrieval algorithms from space. In the experiment, which took place in the fall of 1988 at the NASA Wallops Flight Facility, VA, both stratiform and convective storms were observed. A ground-based radar and rain gauges were also used to obtain truth data. An external radar calibration is made with rain gauge data, thereby enabling quantitative reflectivity measurements. Comparisons between path attenuations derived from the surface return and from the radar reflectivity profile are made to test the feasibility of a technique to estimate the raindrop size distribution from simultaneous radar and path-attenuation measurements.

  5. Quantitative research regarding performance measures for intermodal freight transportation : executive summary (United States)


    The primary objective of this study is to provide information relative to the development of a set of performance measures for intermodal freight transportation. To accomplish this objective, data was collected, processed, and analyzed on the basis o...

  6. Patient and healthcare provider barriers to hypertension awareness, treatment and follow up: a systematic review and meta-analysis of qualitative and quantitative studies.

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    Rasha Khatib

    Full Text Available BACKGROUND: Although the importance of detecting, treating, and controlling hypertension has been recognized for decades, the majority of patients with hypertension remain uncontrolled. The path from evidence to practice contains many potential barriers, but their role has not been reviewed systematically. This review aimed to synthesize and identify important barriers to hypertension control as reported by patients and healthcare providers. METHODS: Electronic databases MEDLINE, EMBASE and Global Health were searched systematically up to February 2013. Two reviewers independently selected eligible studies. Two reviewers categorized barriers based on a theoretical framework of behavior change. The theoretical framework suggests that a change in behavior requires a strong commitment to change [intention], the necessary skills and abilities to adopt the behavior [capability], and an absence of health system and support constraints. FINDINGS: Twenty-five qualitative studies and 44 quantitative studies met the inclusion criteria. In qualitative studies, health system barriers were most commonly discussed in studies of patients and health care providers. Quantitative studies identified disagreement with clinical recommendations as the most common barrier among health care providers. Quantitative studies of patients yielded different results: lack of knowledge was the most common barrier to hypertension awareness. Stress, anxiety and depression were most commonly reported as barriers that hindered or delayed adoption of a healthier lifestyle. In terms of hypertension treatment adherence, patients mostly reported forgetting to take their medication. Finally, priority setting barriers were most commonly reported by patients in terms of following up with their health care providers. CONCLUSIONS: This review identified a wide range of barriers facing patients and health care providers pursuing hypertension control, indicating the need for targeted multi

  7. Measuring value at the provider level in the management of cleft lip and palate patients. (United States)

    Abbott, Megan M; Rosen, Heather; Kupfer, Philipp; Meara, John G


    "Value" has become a buzzword in current health-care discussions. This study demonstrates a provider-led strategy to measuring costs, an understudied component of the value equation, for a complex diagnosis for the purposes of improvement. A retrospective, microcosting methodology was used to measure costs for all hospital and physician services and costs to the patient over 18 months of multidisciplinary care for patients with cleft lip and palate. Short-term outcomes were also recorded. Overall costs to all parts of the system ranged from $35,826 to $56,611 for different subtypes, and insight was gained into major cost drivers and variations in care that will drive internal improvement efforts. It is critical that providers learn to work together and become familiar with their own costs in conjunction with outcomes as insurers increase pressure to reduce payments or accept alternative payments so that well-informed decisions can be made.

  8. Cross-method validation as a solution to the problem of excessive simplification of measurement in quantitative IR research

    DEFF Research Database (Denmark)

    Beach, Derek


    The purpose of this article is to make IR scholars more aware of the costs of choosing quantitative methods. The article first shows that quantification can have analytical ‘costs’ when the measures created are too simple to capture the essence of the systematized concept that was supposed...... detail based upon a review of the democratic peace literature. I then offer two positive suggestions for a way forward. First, I argue that quantitative scholars should spend more time validating their measures, and in particular should engage in multi-method partnerships with qualitative scholars...... that have a deep understanding of particular cases in order to exploit the comparative advantages of qualitative methodology, using the more accurate qualitative measures to validate their own quantitative measures. Secondly, quantitative scholars should lower their level of ambition given the often poor...

  9. Region-specific disturbed iron distribution in early idiopathic Parkinson's disease measured by quantitative susceptibility mapping. (United States)

    He, Naying; Ling, Huawei; Ding, Bei; Huang, Juan; Zhang, Yong; Zhang, Zhongping; Liu, Chunlei; Chen, Kemin; Yan, Fuhua


    In Parkinson's disease (PD), iron elevation in specific brain regions as well as selective loss of dopaminergic neurons is a major pathologic feature. A reliable quantitative measure of iron deposition is a potential biomarker for PD and may contribute to the investigation of iron-mediated PD. The primary purpose of this study is to assess iron variations in multiple deep grey matter nuclei in early PD with a novel MRI technique, quantitative susceptibility mapping (QSM). The inter-group differences of susceptibility and R2* value in deep grey matter nuclei, namely head of caudate nucleus (CN), putamen (PUT), global pallidus (GP), substantia nigra (SN), and red nucleus (RN), and the correlations between regional iron deposition and the clinical features were explored in forty-four early PD patients and 35 gender and age-matched healthy controls. Susceptibility values were found to be elevated within bilateral SN and RN contralateral to the most affected limb in early PD compared with healthy controls (HCs). The finding of increased susceptibility in bilateral SN is consistent with work on a subgroup of patients at the earliest clinical detectable state (Hoehn and Yahr [1967]: Neurology 17:427-442; Stage I). However, increased R2* values were only seen within SN contralateral to the most affected limb in the PD group when compared with controls. Furthermore, bilateral SN magnetic susceptibility positively correlated with disease duration and UPDRS-III scores in early PD. This finding supports the potential value of QSM as a non-invasive quantitative biomarker of early PD. © 2015 Wiley Periodicals, Inc.

  10. Epithelium percentage estimation facilitates epithelial quantitative protein measurement in tissue specimens. (United States)

    Chen, Jing; Toghi Eshghi, Shadi; Bova, George Steven; Li, Qing Kay; Li, Xingde; Zhang, Hui


    The rapid advancement of high-throughput tools for quantitative measurement of proteins has demonstrated the potential for the identification of proteins associated with cancer. However, the quantitative results on cancer tissue specimens are usually confounded by tissue heterogeneity, e.g. regions with cancer usually have significantly higher epithelium content yet lower stromal content. It is therefore necessary to develop a tool to facilitate the interpretation of the results of protein measurements in tissue specimens. Epithelial cell adhesion molecule (EpCAM) and cathepsin L (CTSL) are two epithelial proteins whose expressions in normal and tumorous prostate tissues were confirmed by measuring staining intensity with immunohistochemical staining (IHC). The expressions of these proteins were measured by ELISA in protein extracts from OCT embedded frozen prostate tissues. To eliminate the influence of tissue heterogeneity on epithelial protein quantification measured by ELISA, a color-based segmentation method was developed in-house for estimation of epithelium content using H&E histology slides from the same prostate tissues and the estimated epithelium percentage was used to normalize the ELISA results. The epithelium contents of the same slides were also estimated by a pathologist and used to normalize the ELISA results. The computer based results were compared with the pathologist's reading. We found that both EpCAM and CTSL levels, measured by ELISA assays itself, were greatly affected by epithelium content in the tissue specimens. Without adjusting for epithelium percentage, both EpCAM and CTSL levels appeared significantly higher in tumor tissues than normal tissues with a p value less than 0.001. However, after normalization by the epithelium percentage, ELISA measurements of both EpCAM and CTSL were in agreement with IHC staining results, showing a significant increase only in EpCAM with no difference in CTSL expression in cancer tissues. These results

  11. Linear approaches to intramolecular Förster resonance energy transfer probe measurements for quantitative modeling.

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    Marc R Birtwistle

    Full Text Available Numerous unimolecular, genetically-encoded Förster Resonance Energy Transfer (FRET probes for monitoring biochemical activities in live cells have been developed over the past decade. As these probes allow for collection of high frequency, spatially resolved data on signaling events in live cells and tissues, they are an attractive technology for obtaining data to develop quantitative, mathematical models of spatiotemporal signaling dynamics. However, to be useful for such purposes the observed FRET from such probes should be related to a biological quantity of interest through a defined mathematical relationship, which is straightforward when this relationship is linear, and can be difficult otherwise. First, we show that only in rare circumstances is the observed FRET linearly proportional to a biochemical activity. Therefore in most cases FRET measurements should only be compared either to explicitly modeled probes or to concentrations of products of the biochemical activity, but not to activities themselves. Importantly, we find that FRET measured by standard intensity-based, ratiometric methods is inherently non-linear with respect to the fraction of probes undergoing FRET. Alternatively, we find that quantifying FRET either via (1 fluorescence lifetime imaging (FLIM or (2 ratiometric methods where the donor emission intensity is divided by the directly-excited acceptor emission intensity (denoted R(alt is linear with respect to the fraction of probes undergoing FRET. This linearity property allows one to calculate the fraction of active probes based on the FRET measurement. Thus, our results suggest that either FLIM or ratiometric methods based on R(alt are the preferred techniques for obtaining quantitative data from FRET probe experiments for mathematical modeling purposes.

  12. Quantitative analysis of emphysema and airway measurements according to iterative reconstruction algorithms: comparison of filtered back projection, adaptive statistical iterative reconstruction and model-based iterative reconstruction. (United States)

    Choo, Ji Yung; Goo, Jin Mo; Lee, Chang Hyun; Park, Chang Min; Park, Sang Joon; Shim, Mi-Suk


    To evaluate filtered back projection (FBP) and two iterative reconstruction (IR) algorithms and their effects on the quantitative analysis of lung parenchyma and airway measurements on computed tomography (CT) images. Low-dose chest CT obtained in 281 adult patients were reconstructed using three algorithms: FBP, adaptive statistical IR (ASIR) and model-based IR (MBIR). Measurements of each dataset were compared: total lung volume, emphysema index (EI), airway measurements of the lumen and wall area as well as average wall thickness. Accuracy of airway measurements of each algorithm was also evaluated using an airway phantom. EI using a threshold of -950 HU was significantly different among the three algorithms in decreasing order of FBP (2.30 %), ASIR (1.49 %) and MBIR (1.20 %) (P algorithms with FBP (2.09 mm) demonstrating thicker walls than ASIR (2.00 mm) and MBIR (1.88 mm) (P analysis revealed that MBIR showed the most accurate value for airway measurements. The three algorithms presented different EIs and wall thicknesses, decreasing in the order of FBP, ASIR and MBIR. Thus, care should be taken in selecting the appropriate IR algorithm on quantitative analysis of the lung. • Computed tomography is increasingly used to provide objective measurements of intra-thoracic structures. • Iterative reconstruction algorithms can affect quantitative measurements of lung and airways. • Care should be taken in selecting reconstruction algorithms in longitudinal analysis. • Model-based iterative reconstruction seems to provide the most accurate airway measurements.

  13. Process measures or patient reported experience measures (PREMs) for comparing performance across providers? A study of measures related to access and continuity in Swedish primary care. (United States)

    Glenngård, Anna H; Anell, Anders


    Aim To study (a) the covariation between patient reported experience measures (PREMs) and registered process measures of access and continuity when ranking providers in a primary care setting, and (b) whether registered process measures or PREMs provided more or less information about potential linkages between levels of access and continuity and explaining variables. Access and continuity are important objectives in primary care. They can be measured through registered process measures or PREMs. These measures do not necessarily converge in terms of outcomes. Patient views are affected by factors not necessarily reflecting quality of services. Results from surveys are often uncertain due to low response rates, particularly in vulnerable groups. The quality of process measures, on the other hand, may be influenced by registration practices and are often more easy to manipulate. With increased transparency and use of quality measures for management and governance purposes, knowledge about the pros and cons of using different measures to assess the performance across providers are important. Four regression models were developed with registered process measures and PREMs of access and continuity as dependent variables. Independent variables were characteristics of providers as well as geographical location and degree of competition facing providers. Data were taken from two large Swedish county councils. Findings Although ranking of providers is sensitive to the measure used, the results suggest that providers performing well with respect to one measure also tended to perform well with respect to the other. As process measures are easier and quicker to collect they may be looked upon as the preferred option. PREMs were better than process measures when exploring factors that contributed to variation in performance across providers in our study; however, if the purpose of comparison is continuous learning and development of services, a combination of PREMs and


    Directory of Open Access Journals (Sweden)

    Valderí de Castro Alcântara


    Full Text Available This article aims at the analysis of the organizational culture at enterprises located in two towns with distinct quantitative traits, Rio Paranaíba and Araxá. While the surveyed enterprises in Rio Paranaíba are mostly micro and small enterprises (86%, in Araxá there are mostly medium and large companies (53%. The overall objective is to verify if there are significant differences in organizational culture among these enterprises and if they can be explained by the organization size. The research was quantitative and instruments for data collection were a questionnaire and a scale for measuring organizational culture containing four dimensions: Hierarchical Distance Index (IDH, Individualism Index (INDI, Masculinity Index (MASC and the Uncertainty Control Index (CINC. Tabulation and analysis of data were performed using the PASW Statistics 18, doing descriptive and inferential statistical procedures. Using a Reduction Factor (-21 the achieved indexes were classified into 5 intensity categories (from "very low" to "very high". The Student t test for two means was performed, revealing significant differences in Hierarchical Distance and Individualism between Araxá and Rio Paranaíba enterprises (p <0.05.   Keywords Organizational Culture; Dimensions of Organizational Culture; Araxá; Rio Paranaíba.

  15. Measurement of lentiviral vector titre and copy number by cross-species duplex quantitative PCR. (United States)

    Christodoulou, I; Patsali, P; Stephanou, C; Antoniou, M; Kleanthous, M; Lederer, C W


    Lentiviruses are the vectors of choice for many preclinical studies and clinical applications of gene therapy. Accurate measurement of biological vector titre before treatment is a prerequisite for vector dosing, and the calculation of vector integration sites per cell after treatment is as critical to the characterisation of modified cell products as it is to long-term follow-up and the assessment of risk and therapeutic efficiency in patients. These analyses are typically based on quantitative real-time PCR (qPCR), but as yet compromise accuracy and comparability between laboratories and experimental systems, the former by using separate simplex reactions for the detection of endogene and lentiviral sequences and the latter by designing different PCR assays for analyses in human cells and animal disease models. In this study, we validate in human and murine cells a qPCR system for the single-tube assessment of lentiviral vector copy numbers that is suitable for analyses in at least 33 different mammalian species, including human and other primates, mouse, pig, cat and domestic ruminants. The established assay combines the accuracy of single-tube quantitation by duplex qPCR with the convenience of one-off assay optimisation for cross-species analyses and with the direct comparability of lentiviral transduction efficiencies in different species.

  16. Videoendoscopic measurement of food bolus formation for quantitative evaluation of masticatory function. (United States)

    Abe, Risako; Furuya, Junichi; Suzuki, Tetsuya


    In the field of prosthodontics, many methods for evaluating the masticatory function involve ejection of the food bolus from the mouth. In addition, these methods could not evaluate mastication and swallowing function comprehensively. The present study aimed to quantitatively evaluate masticatory functions during a series of masticatory and swallowing movements by using videoendoscopy. Subjects are ten healthy dentulous adults without dysphagia. The test foods used were 2-colored (green and white) molded rice and uirou (rice cake). The test foods were consumed under the restriction on the number of mastication (10, 15, 20, and 30), and under the instruction to "chew normally" or "chew well". The masticatory function was evaluated by observing the food bolus in the oropharynx with a videoendoscope. The bolus formation index (BFI), in terms of the degree of mixing of the green and white parts, was quantitatively determined using an image measurement software. The BFI of the rice and uirou increased significantly with increase in the number of mastication times (pmasticatory function during a series of masticatory and swallowing movements. Copyright © 2011 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

  17. Quantitative method for measuring heat flux emitted from a cryogenic object (United States)

    Duncan, R.V.


    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  18. Measurement variability of quantitative sensory testing in persons with post-stroke shoulder pain. (United States)

    Lindgren, Ingrid; Ekstrand, Elisabeth; Brogårdh, Christina


    To evaluate the measurement variability of quantitative sensory testing (QST) in persons with post-stroke shoulder pain. A test-retest design. Twenty-three persons with post-stroke shoulder pain (median age 65 years). Thermal detection thresholds (cold and warm), pain thresholds (cold and heat) and mechanical pain thresholds (pressure and pin prick) were assessed twice in both arms, 2-3 weeks apart. Measurement variability was analysed with the intraclass correlation coefficient (ICC2.1), the change in mean (đ) with 95% confidence interval (logarithmic scales), and the relative standard error of measurement (SEM%; re-transformed scales). The ICCs for thermal thresholds ranged from 0.48 to 0.89 in the affected (painful) arm and from 0.50 to 0.63 in the unaffected arm, and for mechanical pain thresholds from 0.66 to 0.90 in both arms. No systematic changes in the mean (đ) were found. The SEM% ranged from 4% to 10% for thermal detection and heat pain thresholds, and from 17% to 42% for cold pain and mechanical pain thresholds in both arms. QST measurements, especially cold pain thresholds and mechanical pain thresholds, vary in persons with post-stroke shoulder pain. Before QST can be used routinely to evaluate post-stroke shoulder pain, a test protocol with decreased variability needs to be developed.

  19. A new quantitative method to measure activity of ice structuring proteins using differential scanning calorimetry. (United States)

    Hassa-Roudsari, Majid; Goff, H Douglas


    There are very few quantitative assays to measure the activity of antifreeze proteins (AFPs, or Ice Structuring Proteins, ISPs) and these can be prone to various inaccuracies and inconsistencies. Some methods rely only on unassisted visual assessment. When microscopy is used to measure ice crystal size, it is critical that standardized procedures be adopted, especially when image analysis software is used to quantify sizes. Differential Scanning Calorimetry (DSC) has been used to measure the thermal hysteresis activity (TH) of AFPs. In this study, DSC was used isothermally to measure enthalpic changes associated with structural rearrangements as a function of time. Differences in slopes of isothermal heat flow vs. time between winter wheat ISP or AFP type I containing samples, and those without ISP or AFP type I were demonstrated. ISP or AFP type I containing samples had significantly higher slopes compared to those without ISP or AFP type I. Samples with higher concentration of ISP or AFP type I showed higher slope values during the first hour and took up to 3 hr to attain equilibrium. Differences were attributed to activity of the proteins at the ice interface. Proteinaceous activity of ISPs or AFP type I was confirmed by loss of activity after treatment with protease.

  20. The effects of iterative reconstruction and kernel selection on quantitative computed tomography measures of lung density. (United States)

    Rodriguez, Alfonso; Ranallo, Frank N; Judy, Philip F; Fain, Sean B


    To determine the effects of iterative reconstruction (IR) and high-frequency kernels on quantitative computed tomography (qCT) density measures at reduced X-ray dose. The COPDGene 2 Phantom (CTP 698, The Phantom Laboratory, Salem, NY) with four embedded lung mimicking foam densities (12lb, 20lb, and 4lb), as well as water, air, and acrylic reference inserts, was imaged using a GE 64 slice CT750 HD scanner in helical mode with four current-time products ranging from 12 to 100 mAs. The raw acquired data were reconstructed using standard (STD - low frequency) and Bone (high frequency) kernels with filtered back projection (FBP), 100% ASiR, and Veo reconstruction algorithms. The reference density inserts were manually segmented using Slicer3D (, and the mean, standard deviation, and histograms of the segmented regions were generated using Fiji ( for each reconstruction. Measurements of threshold values placed on the cumulative frequency distribution of voxels determined by these measured histograms at 5%, PD5 phant , and 15%, PD15 phant , (analogous to the relative area below -950 HU (RA-950) and percent density 15 (PD15) in human lung emphysema quantification, respectively), were also performed. The use of high-resolution kernels in conjunction with ASiR and Veo did not significantly affect the mean Hounsfield units (HU) of each of the density standards (density regions. The density histogram became more sharply peaked, and standard deviation was reduced for IR, directly effecting density thresholds, PD5 phant and PD15 phant, placed on the cumulative frequency distribution of each region in the phantom, which serve as analogs to RA-950 and PD15 typically used in lung density quantitation. The combination of high-frequency kernels (Bone) with ASiR mitigates this effect and preserves density measures derived from the image histogram. Moreover, previous studies have shown improved accuracy of qCT airway measures of wall thickness (WT

  1. Quantitative sensory testing measures individual pain responses in emergency department patients

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    Duffy KJ


    Full Text Available Kevin J Duffy, Katharyn L Flickinger, Jeffrey T Kristan, Melissa J Repine, Alexandro Gianforcaro, Rebecca B Hasley, Saad Feroz, Jessica M Rupp, Jumana Al-Baghli, Maria L Pacella, Brian P Suffoletto, Clifton W Callaway Department of Emergency Medicine, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA Background: Refining and individualizing treatment of acute pain in the emergency department (ED is a high priority, given that painful complaints are the most common reasons for ED visits. Few tools exist to objectively measure pain perception in the ED setting. We speculated that variation in perception of fixed painful stimuli would explain individual variation in reported pain and response to treatment among ED patients. Materials and methods: In three studies, we 1 describe performance characteristics of brief quantitative sensory testing (QST in 50 healthy volunteers, 2 test effects of 10 mg oxycodone versus placebo on QST measures in 18 healthy volunteers, and 3 measure interindividual differences in nociception and treatment responses in 198 ED patients with a painful complaint during ED treatment. QST measures adapted for use in the ED included pressure sensation threshold, pressure pain threshold (PPT, pressure pain response (PPR, and cold pain tolerance (CPT tests. Results: First, all QST measures had high inter-rater reliability and test–retest reproducibility. Second, 10 mg oxycodone reduced PPR, increased PPT, and prolonged CPT. Third, baseline PPT and PPR revealed hyperalgesia in 31 (16% ED subjects relative to healthy volunteers. In 173 (88% ED subjects who completed repeat testing 30 minutes after pain treatment, PPT increased and PPR decreased (Cohen’s dz 0.10–0.19. Verbal pain scores (0–10 for the ED complaint decreased by 2.2 (95% confidence intervals [CI]: 1.9, 2.6 (Cohen’s dz 0.97 but did not covary with the changes in PPT and PPR (r=0.05–0.13. Treatment effects were greatest in ED subjects

  2. Measuring access to medicines: a review of quantitative methods used in household surveys

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    Domingues Marlos R


    Full Text Available Abstract Background Medicine access is an important goal of medicine policy; however the evaluation of medicine access is a subject under conceptual and methodological development. The aim of this study was to describe quantitative methodologies to measure medicine access on household level, access expressed as paid or unpaid medicine acquisition. Methods Searches were carried out in electronic databases and health institutional sites; within references from retrieved papers and by contacting authors. Results Nine papers were located. The methodologies of the studies presented differences in the recall period, recruitment of subjects and medicine access characterization. Conclusions The standardization of medicine access indicators and the definition of appropriate recall periods are required to evaluate different medicines and access dimensions, improving studies comparison. Besides, specific keywords must be established to allow future literature reviews about this topic.

  3. Quantitative Velocity Field Measurements in Reduced-Gravity Combustion Science and Fluid Physics Experiments (United States)

    Greenberg, Paul S.; Wernet, Mark P.


    Systems have been developed and demonstrated for performing quantitative velocity measurements in reduced gravity combustion science and fluid physics investigations. The unique constraints and operational environments inherent to reduced-gravity experimental facilities pose special challenges to the development of hardware and software systems. Both point and planar velocimetric capabilities are described, with particular attention being given to the development of systems to support the International Space Station laboratory. Emphasis has been placed on optical methods, primarily arising from the sensitivity of the phenomena of interest to intrusive probes. Limitations on available power, volume, data storage, and attendant expertise have motivated the use of solid-state sources and detectors, as well as efficient analysis capabilities emphasizing interactive data display and parameter control.

  4. Quantitative absorption spectra of quantum wires measured by analysis of attenuated internal emissions (United States)

    Yoshita, Masahiro; Okada, Takayuki; Akiyama, Hidefumi; Okano, Makoto; Ihara, Toshiyuki; Pfeiffer, Loren N.; West, Ken W.


    An absorption-spectroscopy method that utilizes internal emissions as the source of the probe light was used to measure the absorption spectra of quasi-one-dimensional (q-1D) excitons in T-shaped quantum wires embedded in an optical waveguide. The modal absorption area of the 1D ground-state excitons was estimated to be 0.39 eV cm-1 and was almost independent of temperature in the range 4-150 K. Quantitative evaluation using the absorption spectra revealed that the absorption cross-section per unit length at resonance peak and the spectrally integrated absorption cross-section area per unit length of the 1D ground-state excitons were 1.0 nm and 2.5 × 10-3 eV nm, respectively.

  5. A Quantitative Measure For Evaluating Project Uncertainty Under Variation And Risk Effects

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    A. Chenarani


    Full Text Available The effects of uncertainty on a project and the risk event as the consequence of uncertainty are analyzed. The uncertainty index is proposed as a quantitative measure for evaluating the uncertainty of a project. This is done by employing entropy as the indicator of system disorder and lack of information. By employing this index, the uncertainty of each activity and its increase due to risk effects as well as project uncertainty changes as a function of time can be assessed. The results are implemented and analyzed for a small turbojet engine development project as the case study. The results of this study can be useful for project managers and other stakeholders for selecting the most effective risk management and uncertainty controlling method.

  6. Quantitative measurement of the blood flow in peripheral vascular diseases by a new radionuclide plethysmography

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    Kawakami, K.; Mori, Y.; Mashima, Y.; Shimada, T.; Fukuoka, M.


    The purpose of the study is to introduce a new plethysmography using radionuclide (RN) for a quantitative measurement of the blood flow in the extremities following the routine RN angiography. Seventy five patients with various peripheral artery diseases have been examined. RN pletysmography was performed in the supine position 15 min. after the RN angiography using 15 mCi of Tc-99m RBC. The blood flow (F) was calculated by the equation (1) which consists of three parameters, the initial slope of the time-activity curve (dc/dt*t=0) after the venous occlusion on the thigh, changes of radio-activity (C-Co) before and after avascularization by inflation of cuff with 200 mmHg pressure at calf, and the blood volume per unit tissue volume (..beta..=Vb/V,ml/100g tissue). F (ml/min/100g) = ..beta.. (dc/dt*t=0)/C-Co. The blood flow measured simultaneously by RN plethysmography and admittance plethysmography was significantly correlated (r = 0.906,n = 16). The blood flow in 67 normal subjects was 2.78 +- 0.75 ml/min/100g. In the patients with intermittent claudication the blood flow was decreased (1.89 +- 0.75 ml/min/100g,n = 75). In the cases with poorly developed colateral circulation the blood flow markedly decreased (1.62 +- 0.29 ml/min/100g,n = 10). Increases of blood flow after exercise was small in the cases with stenosis, even in patients with collaterals. This method is very useful to evaluate quantitatively the peripheral hemodynamics following the routine RN angiographic examination.

  7. Quantitative optical microscopy: measurement of cellular biophysical features with a standard optical microscope. (United States)

    Phillips, Kevin G; Baker-Groberg, Sandra M; McCarty, Owen J T


    We describe the use of a standard optical microscope to perform quantitative measurements of mass, volume, and density on cellular specimens through a combination of bright field and differential interference contrast imagery. Two primary approaches are presented: noninterferometric quantitative phase microscopy (NIQPM), to perform measurements of total cell mass and subcellular density distribution, and Hilbert transform differential interference contrast microscopy (HTDIC) to determine volume. NIQPM is based on a simplified model of wave propagation, termed the paraxial approximation, with three underlying assumptions: low numerical aperture (NA) illumination, weak scattering, and weak absorption of light by the specimen. Fortunately, unstained cellular specimens satisfy these assumptions and low NA illumination is easily achieved on commercial microscopes. HTDIC is used to obtain volumetric information from through-focus DIC imagery under high NA illumination conditions. High NA illumination enables enhanced sectioning of the specimen along the optical axis. Hilbert transform processing on the DIC image stacks greatly enhances edge detection algorithms for localization of the specimen borders in three dimensions by separating the gray values of the specimen intensity from those of the background. The primary advantages of NIQPM and HTDIC lay in their technological accessibility using "off-the-shelf" microscopes. There are two basic limitations of these methods: slow z-stack acquisition time on commercial scopes currently abrogates the investigation of phenomena faster than 1 frame/minute, and secondly, diffraction effects restrict the utility of NIQPM and HTDIC to objects from 0.2 up to 10 (NIQPM) and 20 (HTDIC) μm in diameter, respectively. Hence, the specimen and its associated time dynamics of interest must meet certain size and temporal constraints to enable the use of these methods. Excitingly, most fixed cellular specimens are readily investigated with

  8. Tracer-based laser-induced fluorescence measurement technique for quantitative fuel/air-ratio measurements in a hydrogen internal combustion engine. (United States)

    Blotevogel, Thomas; Hartmann, Matthias; Rottengruber, Hermann; Leipertz, Alfred


    A measurement technique for the quantitative investigation of mixture formation processes in hydrogen internal combustion engines (ICEs) has been developed using tracer-based laser-induced fluorescence (TLIF). This technique can be employed to fired and motored engine operation. The quantitative TLIF fuel/air-ratio results have been verified by means of linear Raman scattering measurements. Exemplary results of the simultaneous investigation of mixture formation and combustion obtained at an optical accessible hydrogen ICE are shown.

  9. Vectorial Kerr magnetometer for simultaneous and quantitative measurements of the in-plane magnetization components. (United States)

    Jiménez, E; Mikuszeit, N; Cuñado, J L F; Perna, P; Pedrosa, J; Maccariello, D; Rodrigo, C; Niño, M A; Bollero, A; Camarero, J; Miranda, R


    A vectorial magneto-optic Kerr effect (v-MOKE) setup with simultaneous and quantitative determination of the two in-plane magnetization components is described. The setup provides both polarization rotations and reflectivity changes at the same time for a given sample orientation with respect to a variable external magnetic field, as well as allowing full angular studies. A classical description based on the Jones formalism is used to calculate the setup's properties. The use of different incoming light polarizations and/or MOKE geometries, as well as the errors due to misalignment and solutions are discussed. To illustrate the capabilities of the setup a detailed study of a model four-fold anisotropy system is presented. Among others, the setup allows to study the angular dependence of the hysteresis phenomena, remanences, critical fields, and magnetization reversal processes, as well as the accurate determination of the easy and hard magnetization directions, domain wall orientations, and magnetic anisotropies.

  10. Quantitative Doppler measures in coiled vessels: investigation on excised umbilical veins. (United States)

    Guiot, C; Roatta, S; Piccoli, E; Saccomandi, F; Todros, T


    Quantitative assessment of umbilical venous blood velocity with Doppler ultrasound (US) must cope with the coiled structure of the vein inside the cord. Both an experimental and a theoretical approach showed remarkable variations in the insonation angle when the probe was moved along the vein, provided the inclination between the Doppler probe and the cord was kept constant. Inaccurate signal processing, stochastic variability and flow disturbances could, however, mask the influence of the geometry. The above hypotheses were assessed by investigating five cords in vitro a few hours after delivery from normal pregnancies at term. The Doppler signal was sampled at different sites along each cord and the mean Doppler shift estimated by FFT spectral analysis, both directly and through the noise rejection D'Alessio's algorithm, which proved effective in improving the Doppler shift estimate in condition of low signal-to-noise ratio (SNR).

  11. Measuring dynamic membrane fluctuations in cell membrane using quantitative phase imaging (Conference Presentation) (United States)

    Lee, SangYun; Kim, Kyoohyun; Park, YongKeun


    There is a strong correlation between the dynamic membrane fluctuations and the biomechanical properties of living cells. The dynamic membrane fluctuation consists of submicron displacements, and can be altered by changing the cells' pathophysiological conditions. These results have significant relevance to the understanding of RBC biophysics and pathology, as follows. RBCs must withstand large mechanical deformations during repeated passages through the microvasculature and the fenestrated walls of the splenic sinusoids. This essential ability is diminished with senescence, resulting in physiological destruction of the aging RBCs. Pathological destruction of the red cells, however, occurs in cells affected by a host of diseases such as spherocytosis, malaria, and Sickle cell disease, as RBCs depart from their normal discoid shape and lose their deformability. Therefore, quantifying the RBC deformability insight into a variety of problems regarding the interplay of cell structure, dynamics, and function. Furthermore, the ability to monitor mechanical properties of RBCs is of vital interest in monitoring disease progression or response to treatment as molecular and pharmaceutical approaches for treatment of chronic diseases. Here, we present the measurements of dynamic membrane fluctuations in live cells using quantitative phase imaging techniques. Measuring both the 3-D refractive index maps and the dynamic phase images of live cells are simultaneously measured, from which dynamic membrane fluctuation and deformability of cells are precisely calculated. We also present its applications to various diseases ranging from sickle cell diseases, babesiosis, and to diabetes.

  12. Quantitative Measurement of Serum Hepatitis B Surface Antigen Using an Immunoradiometric Assay in Chronic Hepatitis B

    Energy Technology Data Exchange (ETDEWEB)

    Kwon, Hyun Woo; Lee, Ho Young; Kim, Seog Gyun; Kim, Won; Jung, Wong Jin; Kang, Keon Wook; Chung, June Key; Lee, Myung Chul; Lee, Dong Soo [Seoul National Univ. Seoul (Korea, Republic of)


    Measurement of serum hepatitis B virus surface antigen (HBsAg) levels is important for the management of chronic hepatitis D patients in terms of monitoring response to antiviral therapy. This study aimed to evaluate the diagnostic performance of a new diagnostic kit, which quantitatively measures serum HBsAg level using an immunoradiometric assay (IRMA) based method. Measurements were compared with those obtained using a chemiluminescent microparticle immunoassay (CMIA) based method. The blood samples of 96 patients with chronic hepatitis B were used in this study. Copy numbers of serum hepatitis B virus (HBV) DNA were determined in 23 of these samples. The correlation between and the concordance of IRMA and CMIA results were determined using Pearson's correlation coefficients. P values of 0.05 were considered to be statistically significant throughout. Laboratory diagnoses based on CMIA. Furthermors, serum HBsAg levels by IRMA were found to be highly correlated with those determined by CMIA (correlation coefficient R{sup 2=}0.838, P<0.001). Serum HBsAg level and serum HBV DNA copies were found to be linearly related by both methods (R{sup 2=}0.067, P=0.316 by IRMA, and R{sup 2=}0.101, P=0.215 by CMIA). The diagnostic performance of the investigated IRMA method of determining HBsAg levels was found to be comparable with that of a CMIA based method in chronic hepatitis B patients.

  13. Limitations of quantitative photoacoustic measurements of blood oxygenation in small vessels

    Energy Technology Data Exchange (ETDEWEB)

    Sivaramakrishnan, Mathangi [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Maslov, Konstantin [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Zhang, Hao F [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States); Stoica, George [Department of Pathobiology, Texas A and M University, College Station, TX 77843-5547 (United States); Wang, Lihong V [Optical Imaging Laboratory, Department of Biomedical Engineering, Texas A and M University 3120 TAMU, College Station, TX 77843-3120 (United States)


    We investigate the feasibility of obtaining accurate quantitative information, such as local blood oxygenation level (sO{sub 2}), with a spatial resolution of about 50 {mu}m from spectral photoacoustic (PA) measurements. The optical wavelength dependence of the peak values of the PA signals is utilized to obtain the local blood oxygenation level. In our in vitro experimental models, the PA signal amplitude is found to be linearly proportional to the blood optical absorption coefficient when using ultrasonic transducers with central frequencies high enough such that the ultrasonic wavelengths are shorter than the light penetration depth into the blood vessels. For an optical wavelength in the 578-596 nm region, with a transducer central frequency that is above 25 MHz, the sensitivity and accuracy of sO{sub 2} inversion is shown to be better than 4%. The effect of the transducer focal position on the accuracy of quantifying blood oxygenation is found to be negligible. In vivo oxygenation measurements of rat skin microvasculature yield results consistent with those from in vitro studies, although factors specific to in vivo measurements, such as the spectral dependence of tissue optical attenuation, dramatically affect the accuracy of sO{sub 2} quantification in vivo.

  14. Quantitative measurements of human sperm nuclei using automated microscopy and image analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wyrobek, A.J.; Firpo, M. (Lawrence Livermore National Lab., CA (United States)); Sudar, D. (Univ. of California, San Francisco (United States))


    A package of computer codes, called Morphometry Automation Program (MAP), was developed to (a) detect human sperm smeared onto glass slides, (b) measure more than 30 aspects of the size, shape, texture, and staining of their nuclei, and (c) retain operator evaluation of the process. MAP performs the locating and measurement functions automatically, without operator assistance. In addition to standard measurements, MAP utilizes axial projections of nuclear area and stain intensity to detect asymmetries. MAP also stores for each cell the gray-scale images for later display and evaluation, and it retains coordinates for optional relocation and inspection under the microscope. MAP operates on the Quantitative Image Processing System (QUIPS) at LLNL. MAP has potential applications in the evaluation of infertility and in reproductive toxicology, such as (a) classifying sperm into clinical shape categories for assessing fertility status, (b) identifying subtle effects of host factors (diet, stress, etc.), (c) assessing the risk of potential spermatogenic toxicants (tobacco, drugs, etc.), and (d) investigating associations with abnormal pregnancy outcomes (time to pregnancy, early fetal loss, etc.).

  15. Xenon-inhalation computed tomography for noninvasive quantitative measurement of tissue blood flow in pancreatic tumor. (United States)

    Kubota, Masaru; Murakami, Takamichi; Nagano, Hiroaki; Eguchi, Hidetoshi; Marubashi, Shigeru; Kobayashi, Shogo; Wada, Hiroshi; Tanemura, Masahiro; Dono, Keizo; Nakamori, Shoji; Sakon, Masato; Monden, Morito; Mori, Masaki; Doki, Yuichiro


    The purpose of this prospective study was to demonstrate the ability to measure pancreatic tumor tissue blood flow (TBF) with a noninvasive method using xenon inhalation computed tomography (xenon-CT) and to correlate TBF with histological features, particularly microvascular density (MVD). TBFs of pancreatic tumors in 14 consecutive patients were measured by means of xenon-CT at diagnosis and following therapy. Serial abdominal CT scans were obtained before and after inhalation of nonradioactive xenon gas. TBF was calculated using the Fick principle. Furthermore, intratumoral microvessels were stained with anti-CD34 monoclonal antibodies before being quantified by light microscopy (×200). We evaluated MVD based on CD34 expression and correlated it with TBF. The quantitative TBF of pancreatic tumors measured by xenon CT ranged from 22.3 to 111.4 ml/min/100 g (mean ± SD, 59.6 ± 43.9 ml/min/100 g). High correlation (r = 0.885, P Xenon-CT is feasible in patients with pancreatic tumors and is able to accurately estimate MVD noninvasively.

  16. Quantitative IR Spectrum and Vibrational Assignments for Glycolaldehyde Vapor: Glycolaldehyde Measurements in Biomass Burning Plumes

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, Timothy J.; Sams, Robert L.; Profeta, Luisa T.; Akagi, Sheryl; Burling, Ian R.; Yokelson, Robert J.; Williams, Stephen D.


    Glycolaldehyde (GA, 2-hydroxyethanal, C2H4O2) is a semi-volatile molecule of atmospheric importance, recently proposed as a precursor in the formation of aqueous-phase secondary organic aerosol (SOA). There are few methods to measure glycolaldehyde vapor, but infrared spectroscopy has been used successfully. Using vetted protocols we have completed the first assignment of all fundamental vibrational modes and derived quantitative IR absorption band strengths using both neat and pressure-broadened GA vapor. Even though GA is problematic due to its propensity to both dimerize and condense, our intensities agree well with the few previously published values. Using the reference ν10 band Q-branch at 860.51 cm-1, we have also determined GA mixing ratios in biomass burning plumes generated by field and laboratory burns of fuels from the southeastern and southwestern United States, including the first field measurements of glycolaldehyde in smoke. The GA emission factors were anti-correlated with modified combustion efficiency confirming release of GA from smoldering combustion. The GA emission factors (g of GA emitted per kg dry biomass burned on a dry mass basis) had a low dependence on fuel type consistent with the production mechanism being pyrolysis of cellulose. GA was emitted at 0.23 ± 0.13% of CO from field fires and we calculate that it accounts for ~18% of the aqueous-phase SOA precursors that we were able to measure.

  17. Validating Quantitative Measurement Using Qualitative Data: Combining Rasch Scaling and Latent Semantic Analysis in Psychiatry (United States)

    Lange, Rense


    An extension of concurrent validity is proposed that uses qualitative data for the purpose of validating quantitative measures. The approach relies on Latent Semantic Analysis (LSA) which places verbal (written) statements in a high dimensional semantic space. Using data from a medical / psychiatric domain as a case study - Near Death Experiences, or NDE - we established concurrent validity by connecting NDErs qualitative (written) experiential accounts with their locations on a Rasch scalable measure of NDE intensity. Concurrent validity received strong empirical support since the variance in the Rasch measures could be predicted reliably from the coordinates of their accounts in the LSA derived semantic space (R2 = 0.33). These coordinates also predicted NDErs age with considerable precision (R2 = 0.25). Both estimates are probably artificially low due to the small available data samples (n = 588). It appears that Rasch scalability of NDE intensity is a prerequisite for these findings, as each intensity level is associated (at least probabilistically) with a well- defined pattern of item endorsements.

  18. Apparatus and method for qualitative and quantitative measurements of optical properties of turbid media using frequency-domain photon migration (United States)

    Tromberg, Bruce J.; Tsay, Tsong T.; Berns, Michael W.; Svaasand, Lara O.; Haskell, Richard C.


    Optical measurements of turbid media, that is media characterized by multiple light scattering, is provided through an apparatus and method for exposing a sample to a modulated laser beam. The light beam is modulated at a fundamental frequency and at a plurality of integer harmonics thereof. Modulated light is returned from the sample and preferentially detected at cross frequencies at frequencies slightly higher than the fundamental frequency and at integer harmonics of the same. The received radiance at the beat or cross frequencies is compared against a reference signal to provide a measure of the phase lag of the radiance and modulation ratio relative to a reference beam. The phase and modulation amplitude are then provided as a frequency spectrum by an array processor to which a computer applies a complete curve fit in the case of highly scattering samples or a linear curve fit below a predetermined frequency in the case of highly absorptive samples. The curve fit in any case is determined by the absorption and scattering coefficients together with a concentration of the active substance in the sample. Therefore, the curve fitting to the frequency spectrum can be used both for qualitative and quantitative analysis of substances in the sample even though the sample is highly turbid.

  19. Confirmatory factor analytic structure and measurement invariance of quantitative autistic traits measured by the social responsiveness scale-2. (United States)

    Frazier, Thomas W; Ratliff, Kristin R; Gruber, Chris; Zhang, Yi; Law, Paul A; Constantino, John N


    Understanding the factor structure of autistic symptomatology is critical to the discovery and interpretation of causal mechanisms in autism spectrum disorder. We applied confirmatory factor analysis and assessment of measurement invariance to a large (N = 9635) accumulated collection of reports on quantitative autistic traits using the Social Responsiveness Scale, representing a broad diversity of age, severity, and reporter type. A two-factor structure (corresponding to social communication impairment and restricted, repetitive behavior) as elaborated in the updated Diagnostic and Statistical Manual of Mental Disorders (5th ed.; DSM-5) criteria for autism spectrum disorder exhibited acceptable model fit in confirmatory factor analysis. Measurement invariance was appreciable across age, sex, and reporter (self vs other), but somewhat less apparent between clinical and nonclinical populations in this sample comprised of both familial and sporadic autism spectrum disorders. The statistical power afforded by this large sample allowed relative differentiation of three factors among items encompassing social communication impairment (emotion recognition, social avoidance, and interpersonal relatedness) and two factors among items encompassing restricted, repetitive behavior (insistence on sameness and repetitive mannerisms). Cross-trait correlations remained extremely high, that is, on the order of 0.66-0.92. These data clarify domains of statistically significant factoral separation that may relate to partially-but not completely-overlapping biological mechanisms, contributing to variation in human social competency. Given such robust intercorrelations among symptom domains, understanding their co-emergence remains a high priority in conceptualizing common neural mechanisms underlying autistic syndromes.

  20. Mi Piacce – how to measure the pleasures provided by shoe design to physical disabilities

    Directory of Open Access Journals (Sweden)

    Mariana Rachel Roncoletta


    Full Text Available The aim of this paper is presenting Mi Piacce Methodology, which can be applied by shoe wearers to measure the pleasures provided by shoe design for women with lower limb dysmetria. Qualitative methodology was applied with mix techniques, such as comparative analysis of secondary sources, semi-structured interviews with five health professionals, and a phenomenological methodology with nine wearers. After this, it was develop Mi Piacce Methodology, and it was applied in forty-two wearers’ shoes design; eight are presenting in this paper. It can be concluded that the inconsistency in the degree of pleasures provided by the same style of shoes underlines the importance of conducting a holistic analysis to detect the strong and weak points of each shoe design for the wearer.

  1. Measuring the quality of provided services for patients with chronic kidney disease. (United States)

    Bahadori, Mohammadkarim; Raadabadi, Mehdi; Heidari Jamebozorgi, Majid; Salesi, Mahmood; Ravangard, Ramin


    The healthcare organizations need to develop and implement quality improvement plans for their survival and success. Measuring quality in the healthcare competitive environment is an undeniable necessity for these organizations and will lead to improved patient satisfaction. This study aimed to measure the quality of provided services for patients with chronic kidney disease in Kerman in 2014. This cross-sectional, descriptive-analytic study was performed from 23 January 2014 to 14 February 2014 in four hemodialysis centers in Kerman. All of the patients on chronic hemodialysis (n = 195) who were referred to these four centers were selected and studied using census method. The required data were collected using the SERVQUAL questionnaire, consisting of two parts: questions related to the patients' demographic characteristics, and 28 items to measure the patients' expectations and perceptions of the five dimensions of service quality, including tangibility, reliability, responsiveness, assurance, and empathy. The collected data were analyzed using SPSS 21.0 through some statistical tests, including independent-samples t test, one-way ANOVA, and paired-samples t test. The results showed that the means of patients' expectations were more than their perceptions of the quality of provided services in all dimensions, which indicated that there were gaps in all dimensions. The highest and lowest means of negative gaps were related to empathy (-0.52 ± 0.48) and tangibility (-0.29 ± 0.51). In addition, among the studied patients' demographic characteristics and the five dimensions of service quality, only the difference between the patients' income levels and the gap in assurance were statistically significant (P < 0.001). Overall, the results of the present study showed that the expectations of patients on hemodialysis were more than their perceptions of provided services. The healthcare providers and employees should pay more attention to the patients' opinions and

  2. Polarbrdf: A General Purpose Python Package for Visualization Quantitative Analysis of Multi-Angular Remote Sensing Measurements (United States)

    Singh, Manoj K.; Gautam, Ritesh; Gatebe, Charles K.; Poudyal, Rajesh


    The Bidirectional Reflectance Distribution Function (BRDF) is a fundamental concept for characterizing the reflectance property of a surface, and helps in the analysis of remote sensing data from satellite, airborne and surface platforms. Multi-angular remote sensing measurements are required for the development and evaluation of BRDF models for improved characterization of surface properties. However, multi-angular data and the associated BRDF models are typically multidimensional involving multi-angular and multi-wavelength information. Effective visualization of such complex multidimensional measurements for different wavelength combinations is presently somewhat lacking in the literature, and could serve as a potentially useful research and teaching tool in aiding both interpretation and analysis of BRDF measurements. This article describes a newly developed software package in Python (PolarBRDF) to help visualize and analyze multi-angular data in polar and False Color Composite (FCC) forms. PolarBRDF also includes functionalities for computing important multi-angular reflectance/albedo parameters including spectral albedo, principal plane reflectance and spectral reflectance slope. Application of PolarBRDF is demonstrated using various case studies obtained from airborne multi-angular remote sensing measurements using NASA's Cloud Absorption Radiometer (CAR). Our visualization program also provides functionalities for untangling complex surface/atmosphere features embedded in pixel-based remote sensing measurements, such as the FCC imagery generation of BRDF measurements of grasslands in the presence of wild fire smoke and clouds. Furthermore, PolarBRDF also provides quantitative information of the angular distribution of scattered surface/atmosphere radiation, in the form of relevant BRDF variables such as sunglint, hotspot and scattering statistics.

  3. PolarBRDF: A general purpose Python package for visualization and quantitative analysis of multi-angular remote sensing measurements (United States)

    Poudyal, R.; Singh, M.; Gautam, R.; Gatebe, C. K.


    The Bidirectional Reflectance Distribution Function (BRDF) is a fundamental concept for characterizing the reflectance property of a surface, and helps in the analysis of remote sensing data from satellite, airborne and surface platforms. Multi-angular remote sensing measurements are required for the development and evaluation of BRDF models for improved characterization of surface properties. However, multi-angular data and the associated BRDF models are typically multidimensional involving multi-angular and multi-wavelength information. Effective visualization of such complex multidimensional measurements for different wavelength combinations is presently somewhat lacking in the literature, and could serve as a potentially useful research and teaching tool in aiding both interpretation and analysis of BRDF measurements. This article describes a newly developed software package in Python (PolarBRDF) to help visualize and analyze multi-angular data in polar and False Color Composite (FCC) forms. PolarBRDF also includes functionalities for computing important multi-angular reflectance/albedo parameters including spectral albedo, principal plane reflectance and spectral reflectance slope. Application of PolarBRDF is demonstrated using various case studies obtained from airborne multi-angular remote sensing measurements using NASA's Cloud Absorption Radiometer (CAR)- Our visualization program also provides functionalities for untangling complex surface/atmosphere features embedded in pixel-based remote sensing measurements, such as the FCC imagery generation of BRDF measurements of grasslands in the presence of wildfire smoke and clouds. Furthermore, PolarBRDF also provides quantitative information of the angular distribution of scattered surface/atmosphere radiation, in the form of relevant BRDF variables such as sunglint, hotspot and scattering statistics.

  4. Sustainable Urban Forestry Potential Based Quantitative And Qualitative Measurement Using Geospatial Technique (United States)

    Rosli, A. Z.; Reba, M. N. M.; Roslan, N.; Room, M. H. M.


    In order to maintain the stability of natural ecosystems around urban areas, urban forestry will be the best initiative to maintain and control green space in our country. Integration between remote sensing (RS) and geospatial information system (GIS) serves as an effective tool for monitoring environmental changes and planning, managing and developing a sustainable urbanization. This paper aims to assess capability of the integration of RS and GIS to provide information for urban forest potential sites based on qualitative and quantitative by using priority parameter ranking in the new township of Nusajaya. SPOT image was used to provide high spatial accuracy while map of topography, landuse, soils group, hydrology, Digital Elevation Model (DEM) and soil series data were applied to enhance the satellite image in detecting and locating present attributes and features on the ground. Multi-Criteria Decision Making (MCDM) technique provides structural and pair wise quantification and comparison elements and criteria for priority ranking for urban forestry purpose. Slope, soil texture, drainage, spatial area, availability of natural resource, and vicinity of urban area are criteria considered in this study. This study highlighted the priority ranking MCDM is cost effective tool for decision-making in urban forestry planning and landscaping.

  5. Measurement of bubble size distributions in vesiculated rocks with implications for quantitative estimation of eruption processes (United States)

    Toramaru, Atsushi


    This paper outlines methods for determining a bubble size distribution (BSD) and the moments of the BSD function in vesiculated clasts produced by volcanic eruptions. It reports the results of applications of the methods to 11 natural samples and discusses the implications for quantitative estimates of eruption processes. The analysis is based on a quantitative morphological (stereological) method for 2-dimensional imaging of cross-sections of samples. One method determines, with some assumptions, the complete shape of the BSD function from the chord lengths cut by bubbles. The other determines the 1st, 2nd and 3rd moments of distribution functions by measurement of the number of bubbles per unit area, the surface area per unit volume, and the volume fraction of bubbles. Comparison of procedures and results of these two distinct methods shows that the latter yields rather more reliable results than the former, though the results coincide in absolute and relative magnitudes. Results of the analysis for vesiculated rocks from eleven subPlinian to Plinian eruptions show some interesting systematic correlations both between moments of the BSD and between a moment and the eruption column height or the SiO 2 content of magma. These correlations are successfully interpreted in terms of the nucleation and growth processes of bubbles in ascending magmas. This suggests that bubble coalescence does not predominate in sub-Plinian to Plinian explosive eruptions. The moment-moment correlations put constraints on the style of the nucleation and growth process of bubbles. The scaling argument suggests that a single nucleation event and subsequent growth with any kind of bubble interaction under continuous depressurization, which leads to an intermediate growth law between the diffusional growth ( R m ∝ t {2}/{3}) at a constant depressurization rate and the Ostwald ripening ( R m ∝ t {1}/{3}) under a constant pressure, where Rm and t are the mean radius of bubble and the

  6. Quantitative measures of meniscus extrusion predict incident radiographic knee osteoarthritis – data from the Osteoarthritis Initiative (United States)

    Emmanuel, K.; Quinn, E.; Niu, J.; Guermazi, A.; Roemer, F.; Wirth, W.; Eckstein, F.; Felson, D.


    SUMMARY Objective To test the hypothesis that quantitative measures of meniscus extrusion predict incident radiographic knee osteoarthritis (KOA), prior to the advent of radiographic disease. Methods 206 knees with incident radiographic KOA (Kellgren Lawrence Grade (KLG) 0 or 1 at baseline, developing KLG 2 or greater with a definite osteophyte and joint space narrowing (JSN) grade ≥1 by year 4) were matched to 232 control knees not developing incident KOA. Manual segmentation of the central five slices of the medial and lateral meniscus was performed on coronal 3T DESS MRI and quantitative meniscus position was determined. Cases and controls were compared using conditional logistic regression adjusting for age, sex, BMI, race and clinical site. Sensitivity analyses of early (year [Y] 1/2) and late (Y3/4) incidence was performed. Results Mean medial extrusion distance was significantly greater for incident compared to non-incident knees (1.56 mean ± 1.12 mm SD vs 1.29 ± 0.99 mm; +21%, P < 0.01), so was the percent extrusion area of the medial meniscus (25.8 ± 15.8% vs 22.0 ± 13.5%; +17%, P < 0.05). This finding was consistent for knees restricted to medial incidence. No significant differences were observed for the lateral meniscus in incident medial KOA, or for the tibial plateau coverage between incident and non-incident knees. Restricting the analysis to medial incident KOA at Y1/2 differences were attenuated, but reached significance for extrusion distance, whereas no significant differences were observed at incident KOA in Y3/4. Conclusion Greater medial meniscus extrusion predicts incident radiographic KOA. Early onset KOA showed greater differences for meniscus position between incident and non-incident knees than late onset KOA. PMID:26318658

  7. Quantitative measurement of the near-field enhancement of nanostructures by two-photon polymerization. (United States)

    Geldhauser, Tobias; Kolloch, Andreas; Murazawa, Naoki; Ueno, Kosei; Boneberg, Johannes; Leiderer, Paul; Scheer, Elke; Misawa, Hiroaki


    The quantitative determination of the strength of the near-field enhancement in and around nanostructures is essential for optimizing and using these structures for applications. We combine the gaussian intensity distribution of a laser profile and two-photon-polymerization of SU-8 to a suitable tool for the quantitative experimental measurement of the near-field enhancement of a nanostructure. Our results give a feedback to the results obtained by finite-difference time-domain (FDTD) simulations. The structures under investigation are gold nanotriangles on a glass substrate with 85 nm side length and a thickness of 40 nm. We compare the threshold fluence for polymerization for areas of the gaussian intensity profile with and without the near-field enhancement of the nanostructures. The experimentally obtained value of the near-field intensity enhancement is 600 ± 140, independent of the laser power, irradiation time, and spot size. The FDTD simulation shows a pointlike maximum of 2600 at the tip. In a more extended area with an approximate size close to the smallest polymerized structure of 25 nm in diameter, we find a value between 800 and 600. Using our novel approach, we determine the threshold fluence for polymerization of the commercially available photopolymerizable resin SU-8 by a femtosecond laser working at a wavelength of 795 nm and a repetition rate of 82 MHz to be 0.25 J/cm(2) almost independent of the irradiation time and the laser power used. This finding is important for future applications of the method because it enables one to use varying laser systems.

  8. Measuring ecosystem capacity to provide regulating services: forest removal and recovery at Hubbard Brook (USA). (United States)

    Beier, Colin M; Caputo, Jesse; Groffman, Peter M


    In this study, by coupling long-term ecological data with empirical proxies of societal demand for benefits, we measured the capacity of forest watersheds to provide ecosystem services over variable time periods, to different beneficiaries, and in response to discrete perturbations and drivers of change. We revisited one of the earliest ecosystem experiments in North America: the 1963 de-vegetation of a forested catchment at Hubbard Brook Experimental Forest in New Hampshire, USA. Potential benefits of the regulation of water flow, water quality, greenhouse gases, and forest growth were compared between experimental (WS 2) and reference (WS 6) watersheds over a 30-year period. Both watersheds exhibited similarly high capacity for flow regulation, in part because functional loads remained low (i.e., few major storm events) during the de-vegetation period. Drought mitigation capacity, or the maintenance of flows sufficient to satisfy municipal water consumption, was higher in WS 2 due to reduced evapotranspiration associated with loss of plant cover. We also assessed watershed capacity to regulate flows to satisfy different beneficiaries, including hypothetical flood averse and drought averse types. Capacity to regulate water quality was severely degraded during de-vegetation, as nitrate concentrations exceeded drinking water standards on 40% of measurement days. Once forest regeneration began, WS 2 rapidly recovered the capacity to provide safe drinking water, and subsequently mitigated the eutrophication potential of rainwater at a marginally higher level than WS 6. We estimated this additional pollution removal benefit would have to accrue for approximately 65-70 years to offset the net eutrophication cost incurred during forest removal. Overall, our results affirmed the critical role of forest vegetation in water regulation, but also indicated trade-offs associated with forest removal and recovery that partially depend on larger-scale exogenous changes in climate

  9. A Geosynchronous Synthetic Aperture Provides for Disaster Management, Measurement of Soil Moisture, and Measurement of Earth-Surface Dynamics (United States)

    Madsen, Soren; Komar, George (Technical Monitor)


    A GEO-based Synthetic Aperture Radar (SAR) could provide daily coverage of basically all of North and South America with very good temporal coverage within the mapped area. This affords a key capability to disaster management, tectonic mapping and modeling, and vegetation mapping. The fine temporal sampling makes this system particularly useful for disaster management of flooding, hurricanes, and earthquakes. By using a fairly long wavelength, changing water boundaries caused by storms or flooding could be monitored in near real-time. This coverage would also provide revolutionary capabilities in the field of radar interferometry, including the capability to study the interferometric signature immediately before and after an earthquake, thus allowing unprecedented studies of Earth-surface dynamics. Preeruptive volcano dynamics could be studied as well as pre-seismic deformation, one of the most controversial and elusive aspects of earthquakes. Interferometric correlation would similarly allow near real-time mapping of surface changes caused by volcanic eruptions, mud slides, or fires. Finally, a GEO SAR provides an optimum configuration for soil moisture measurement that requires a high temporal sampling rate (1-2 days) with a moderate spatial resolution (1 km or better). From a technological point of view, the largest challenges involved in developing a geosynchronous SAR capability relate to the very large slant range distance from the radar to the mapped area. This leads to requirements for large power or alternatively very large antenna, the ability to steer the mapping area to the left and right of the satellite, and control of the elevation and azimuth angles. The weight of this system is estimated to be 2750 kg and it would require 20 kW of DC-power. Such a system would provide up to a 600 km ground swath in a strip-mapping mode and 4000 km dual-sided mapping in a scan-SAR mode.

  10. Quantitative C2H2 measurements in sooty flames using mid-infrared polarization spectroscopy (United States)

    Sun, Z. W.; Li, Z. S.; Li, B.; Alwahabi, Z. T.; Aldén, M.


    Quantitative measurements of acetylene (C2H2) molecules as a combustion intermediate species in a series of rich premixed C2H4/air flames were non-intrusively performed, spatially resolved, using mid-infrared polarization spectroscopy (IRPS), by probing its fundamental ro-vibrational transitions. The flat sooty C2H4/air premixed flames with different equivalence ratios varying from 1.25 to 2.50 were produced on a 6 cm diameter porous-plug McKenna type burner at atmospheric pressure, and all measurements were performed at a height of 8.5 mm above the burner surface. IRPS excitation scans in different flame conditions were performed and rotational line-resolved spectra were recorded. Spectral features of acetylene molecules were readily recognized in the spectral ranges selected, with special attention to avoid the spectral interference from the large amount of coexisting hot water and other hydrocarbon molecules. On-line calibration of the optical system was performed in a laminar C2H2/N2 gas flow at ambient conditions. Using the flame temperatures measured by coherent anti-Stokes Raman spectroscopy in a previous work, C2H2 mole fractions in different flames were evaluated with collision effects and spectral overlap between molecular line and laser source being analyzed and taken into account. C2H2 IRPS signals in two different buffering gases, N2 and CO2, had been investigated in a tube furnace in order to estimate the spectral overlap coefficients and collision effects at different temperatures. The soot-volume fractions (SVF) in the studied flames were measured using a He-Ne laser-extinction method, and no obvious degrading of the IRPS technique due to the sooty environment has been observed in the flame with SVF up to ˜2×10-7. With the increase of flame equivalence ratios not only the SVF but also the C2H2 mole fractions increased.

  11. Associations between quantitative mobility measures derived from components of conventional mobility testing and Parkinsonian gait in older adults.

    Directory of Open Access Journals (Sweden)

    Aron S Buchman

    Full Text Available OBJECTIVE: To provide objective measures which characterize mobility in older adults assessed in the community setting and to examine the extent to which these measures are associated with parkinsonian gait. METHODS: During conventional mobility testing in the community-setting, 351 ambulatory non-demented Memory and Aging Project participants wore a belt with a whole body sensor that recorded both acceleration and angular velocity in 3 directions. We used measures derived from these recordings to quantify 5 subtasks including a walking, b transition from sit to stand, c transition from stand to sit, d turning and e standing posture. Parkinsonian gait and other mild parkinsonian signs were assessed with a modified version of the original Unified Parkinson's Disease Rating Scale (mUPDRS. RESULTS: In a series of separate regression models which adjusted for age and sex, all 5 mobility subtask measures were associated with parkinsonian gait and accounted for 2% to 32% of its variance. When all 5 subtask measures were considered in a single model, backward elimination showed that measures of walking sit to stand and turning showed independent associations with parkinsonian gait and together accounted for more than 35% of its variance. Cross-validation using data from a 2(nd group of 258 older adults showed similar results. In similar analyses, only walking was associated with bradykinesia and sway with tremor. INTERPRETATION: Quantitative mobility subtask measures vary in their associations with parkinsonian gait scores and other parkinsonian signs in older adults. Quantifying the different facets of mobility has the potential to facilitate the clinical characterization and understanding the biologic basis for impaired mobility in older adults.

  12. Health care providers' perceptions of and attitudes towards induced abortions in sub-Saharan Africa and Southeast Asia: a systematic literature review of qualitative and quantitative data. (United States)

    Rehnström Loi, Ulrika; Gemzell-Danielsson, Kristina; Faxelid, Elisabeth; Klingberg-Allvin, Marie


    Unsafe abortions are a serious public health problem and a major human rights issue. In low-income countries, where restrictive abortion laws are common, safe abortion care is not always available to women in need. Health care providers have an important role in the provision of abortion services. However, the shortage of health care providers in low-income countries is critical and exacerbated by the unwillingness of some health care providers to provide abortion services. The aim of this study was to identify, summarise and synthesise available research addressing health care providers' perceptions of and attitudes towards induced abortions in sub-Saharan Africa and Southeast Asia. A systematic literature search of three databases was conducted in November 2014, as well as a manual search of reference lists. The selection criteria included quantitative and qualitative research studies written in English, regardless of the year of publication, exploring health care providers' perceptions of and attitudes towards induced abortions in sub-Saharan Africa and Southeast Asia. The quality of all articles that met the inclusion criteria was assessed. The studies were critically appraised, and thematic analysis was used to synthesise the data. Thirty-six studies, published during 1977 and 2014, including data from 15 different countries, met the inclusion criteria. Nine key themes were identified as influencing the health care providers' attitudes towards induced abortions: 1) human rights, 2) gender, 3) religion, 4) access, 5) unpreparedness, 6) quality of life, 7) ambivalence 8) quality of care and 9) stigma and victimisation. Health care providers in sub-Saharan Africa and Southeast Asia have moral-, social- and gender-based reservations about induced abortion. These reservations influence attitudes towards induced abortions and subsequently affect the relationship between the health care provider and the pregnant woman who wishes to have an abortion. A values

  13. Lactate as a novel quantitative measure of viability in Schistosoma mansoni drug sensitivity assays. (United States)

    Howe, Stephanie; Zöphel, Dorina; Subbaraman, Harini; Unger, Clemens; Held, Jana; Engleitner, Thomas; Hoffmann, Wolfgang H; Kreidenweiss, Andrea


    Whole-organism compound sensitivity assays are a valuable strategy in infectious diseases to identify active molecules. In schistosomiasis drug discovery, larval-stage Schistosoma allows the use of a certain degree of automation in the screening of compounds. Unfortunately, the throughput is limited, as drug activity is determined by manual assessment of Schistosoma viability by microscopy. To develop a simple and quantifiable surrogate marker for viability, we targeted glucose metabolism, which is central to Schistosoma survival. Lactate is the end product of glycolysis in human Schistosoma stages and can be detected in the supernatant. We assessed lactate as a surrogate marker for viability in Schistosoma drug screening assays. We thoroughly investigated parameters of lactate measurement and performed drug sensitivity assays by applying schistosomula and adult worms to establish a proof of concept. Lactate levels clearly reflected the viability of schistosomula and correlated with schistosomulum numbers. Compounds with reported potencies were tested, and activities were determined by lactate assay and by microscopy. We conclude that lactate is a sensitive and simple surrogate marker to be measured to determine Schistosoma viability in compound screening assays. Low numbers of schistosomula and the commercial availability of lactate assay reagents make the assay particularly attractive to throughput approaches. Furthermore, standardization of procedures and quantitative evaluation of compound activities facilitate interassay comparisons of potencies and, thus, concerted drug discovery approaches. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  14. Model-independent quantitative measurement of nanomechanical oscillator vibrations using electron-microscope linescans

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Huan; Fenton, J. C.; Chiatti, O. [London Centre for Nanotechnology, University College London, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Warburton, P. A. [London Centre for Nanotechnology, University College London, 17–19 Gordon Street, London WC1H 0AH (United Kingdom); Department of Electronic and Electrical Engineering, University College London, Torrington Place, London WC1E 7JE (United Kingdom)


    Nanoscale mechanical resonators are highly sensitive devices and, therefore, for application as highly sensitive mass balances, they are potentially superior to micromachined cantilevers. The absolute measurement of nanoscale displacements of such resonators remains a challenge, however, since the optical signal reflected from a cantilever whose dimensions are sub-wavelength is at best very weak. We describe a technique for quantitative analysis and fitting of scanning-electron microscope (SEM) linescans across a cantilever resonator, involving deconvolution from the vibrating resonator profile using the stationary resonator profile. This enables determination of the absolute amplitude of nanomechanical cantilever oscillations even when the oscillation amplitude is much smaller than the cantilever width. This technique is independent of any model of secondary-electron emission from the resonator and is, therefore, applicable to resonators with arbitrary geometry and material inhomogeneity. We demonstrate the technique using focussed-ion-beam–deposited tungsten cantilevers of radius ∼60–170 nm inside a field-emission SEM, with excitation of the cantilever by a piezoelectric actuator allowing measurement of the full frequency response. Oscillation amplitudes approaching the size of the primary electron-beam can be resolved. We further show that the optimum electron-beam scan speed is determined by a compromise between deflection of the cantilever at low scan speeds and limited spatial resolution at high scan speeds. Our technique will be an important tool for use in precise characterization of nanomechanical resonator devices.

  15. Development of Screening Method for an Frail Elderly by Measurement Quantitative Lower Limb Muscular Strength (United States)

    Yamashita, Kazuhiko; Iwakami, Yumi; Imaizumi, Kazuya; Sato, Mitsuru; Nakajima, Sawako; Ino, Shuichi; Kawasumi, Masashi; Ifukube, Tohru

    Falling is one of the most serious problems for the elderly. The aim of this study was to develop a screening method for identifying factors that increase the risk of falling among the elderly, particularly with regard to lower limb muscular strength. Subjects were 48 elderly volunteers, including 25 classed as healthy and 23 classed as frail. All subjects underwent measurement of lower limb muscular strength via toe gap force and measurement of muscle strength of the hip joint adductor via knee gap force. In the frail group, toe gap force of the right foot was 20% lower than that in the healthy group; toe gap force of the left foot in the frail group was 23% lower than that in the healthy group, while knee gap force was 20% lower. Furthermore, we found that combining left toe gap force and knee gap force gave the highest odds ratio (6.05) with 82.6% sensitivity and 56.0% specificity when the toe gap force was 24 N and the knee gap force was 100 N. Thus, lower limb muscular strength can be used for simple and efficient screening, and approaches to prevent falls can be based on quantitative data such as lower limb muscular strength.

  16. Quantitative measurement of carbon nanotubes released from their composites by thermal carbon analysis (United States)

    Ogura, I.; Kotake, M.; Ata, S.; Honda, K.


    The release of free carbon nanotubes (CNTs) and CNTs partly embedded in matrix debris into the air may occur during mechanical and abrasion processes involving CNT composites. Since the harmful effects of CNT-matrix mixtures have not yet been fully evaluated, it is considered that any exposure to CNTs, including CNT-matrix mixtures, should be measured and controlled. Thermal carbon analysis, such as Method 5040 of the National Institute for Occupational Safety and Health, is one of the most reliable quantitative methods for measuring CNTs in the air. However, when CNTs are released together with polymer matrices, this technique may be inapplicable. In this study, we evaluated the potential for using thermal carbon analysis to determine CNTs in the presence of polymer matrices. Our results showed that thermal carbon analysis was potentially capable of determining CNTs in distinction from polyamide 12, polybutylene terephthalate, polypropylene, and polyoxymethylene. However, it was difficult to determine CNTs in the presence of polyethylene terephthalate, polycarbonate, polyetheretherketone, or polyamide 6.

  17. Quantitative tract-specific measures of uncinate and cingulum in major depression using diffusion tensor imaging. (United States)

    Zhang, Aifeng; Leow, Alex; Ajilore, Olusola; Lamar, Melissa; Yang, Shaolin; Joseph, Josh; Medina, Jennifer; Zhan, Liang; Kumar, Anand


    Previous findings suggested the role of the prefrontal cortex, hippocampus, and cingulate gyrus in major depressive disorders (MDD), but the white matter microstructural abnormalities of the fibers connecting these brain structures are not known. The purpose of this study was to test the hypothesis that white matter abnormalities are present in association fibers of the uncinate fasciculus (UF) and cingulum bundle (CB) among MDD subjects. A total of 21 MDD subjects aged between 30 and 65 years and 21 age-matched healthy controls (HC) were recruited. All subjects were right-handed and without history of diabetes or other cardiac diseases. We extracted quantitative tract-specific measures based on diffusion tensor imaging tractography to examine both diffusivity and geometric properties of the UF and CB. Significantly decreased fractional anisotropy (FA) and increased radial diffusivity of the right UF were observed in MDD patients compared with HC (pR) in both groups in the FA measure of the CB. Our study demonstrates novel findings of white matter microstructural abnormalities of the right UF in MDD. In the MDD group, the severity of depression is associated with reduced NNF in the right UF. These findings have implications for both clinical manifestations of depression as well as its pathophysiology.

  18. A novel Raman spectrophotometric method for quantitative measurement of nucleoside triphosphate hydrolysis. (United States)

    Jenkins, R H; Tuma, R; Juuti, J T; Bamford, D H; Thomas, G J


    A novel spectrophotometric method, based upon Raman spectroscopy, has been developed for accurate quantitative determination of nucleoside triphosphate phosphohydrolase (NTPase) activity. The method relies upon simultaneous measurement in real time of the intensities of Raman marker bands diagnostic of the triphosphate (1115 cm(-1)) and diphosphate (1085 cm(-1)) moieties of the NTPase substrate and product, respectively. The reliability of the method is demonstrated for the NTPase-active RNA-packaging enzyme (protein P4) of bacteriophage phi6, for which comparative NTPase activities have been estimated independently by radiolabeling assays. The Raman-determined rate for adenosine triphosphate substrate (8.6 +/- 1.3 micromol x mg(-1) x min(-1) at 40 degrees C) is in good agreement with previous estimates. The versatility of the Raman method is demonstrated by its applicability to a variety of nucleotide substrates of P4, including the natural ribonucleoside triphosphates (ATP, GTP) and dideoxynucleoside triphosphates (ddATP, ddGTP). Advantages of the present protocol include conservative sample requirements (approximately 10(-6) g enzyme/protocol) and relative ease of data collection and analysis. The latter conveniences are particularly advantageous for the measurement of activation energies of phosphohydrolase activity.

  19. Advances in quantitative hepcidin measurements by time-of-flight mass spectrometry.

    Directory of Open Access Journals (Sweden)

    Dorine W Swinkels

    Full Text Available Assays for the detection of the iron regulatory hormone hepcidin in plasma or urine have not yet been widely available, whereas quantitative comparisons between hepcidin levels in these different matrices were thus far even impossible due to technical restrictions. To circumvent these limitations, we here describe several advances in time-of flight mass spectrometry (TOF MS, the most important of which concerned spiking of a synthetic hepcidin analogue as internal standard into serum and urine samples. This serves both as a control for experimental variation, such as recovery and matrix-dependent ionization and ion suppression, and at the same time allows value assignment to the measured hepcidin peak intensities. The assay improvements were clinically evaluated using samples from various patients groups and its relevance was further underscored by the significant correlation of serum hepcidin levels with serum iron indices in healthy individuals. Most importantly, this approach allowed kinetic studies as illustrated by the paired analyses of serum and urine samples, showing that more than 97% of the freely filtered serum hepcidin can be reabsorbed in the kidney. Thus, the here reported advances in TOF MS-based hepcidin measurements represent critical steps in the accurate quantification of hepcidin in various body fluids and pave the way for clinical studies on the kinetic behavior of hepcidin in both healthy and diseased states.

  20. Advances in quantitative hepcidin measurements by time-of-flight mass spectrometry. (United States)

    Swinkels, Dorine W; Girelli, Domenico; Laarakkers, Coby; Kroot, Joyce; Campostrini, Natascia; Kemna, Erwin H J M; Tjalsma, Harold


    Assays for the detection of the iron regulatory hormone hepcidin in plasma or urine have not yet been widely available, whereas quantitative comparisons between hepcidin levels in these different matrices were thus far even impossible due to technical restrictions. To circumvent these limitations, we here describe several advances in time-of flight mass spectrometry (TOF MS), the most important of which concerned spiking of a synthetic hepcidin analogue as internal standard into serum and urine samples. This serves both as a control for experimental variation, such as recovery and matrix-dependent ionization and ion suppression, and at the same time allows value assignment to the measured hepcidin peak intensities. The assay improvements were clinically evaluated using samples from various patients groups and its relevance was further underscored by the significant correlation of serum hepcidin levels with serum iron indices in healthy individuals. Most importantly, this approach allowed kinetic studies as illustrated by the paired analyses of serum and urine samples, showing that more than 97% of the freely filtered serum hepcidin can be reabsorbed in the kidney. Thus, the here reported advances in TOF MS-based hepcidin measurements represent critical steps in the accurate quantification of hepcidin in various body fluids and pave the way for clinical studies on the kinetic behavior of hepcidin in both healthy and diseased states.

  1. Sex differences in bone marrow density measured by quantitative ultrasonometry: For 20 year old college student

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Won Jeong [Dept. of Radiological Technology, Daejeon Health Institute of Technology, Daejeon (Korea, Republic of)


    The purpose of this study is to compare the bone marrow density measured by quantitative ultrasonometry (QUS) between men and women. Questionnaires for general characteristics were obtained from 104 participants, and then their both calcaneus was measured by using QUS. Sex differences for bone marrow density (BMD) were analyzed by an Independent t-test using the SPSS 19.0 program. Of 104 participants, women and men were 69(66.3%) and 35(33.7%), respectively. T-value of left calcaneus was high significantly in women than that in men(0.443 vs. 0.031, p=0.161) as well as that of right calcaneus(0.555 vs. 0.049, p=0.093). T-value of right calcaneus was high than that of left calcaneus in women and men (not significant, p>0.05). T-value of both calcaneus was increasing with physical activity. T-value of calcaneus was no statistically significant with age and body mass index. The BMD of women is high significantly more than that of men, and BMD is relation with physical activity.

  2. Measuring Physical Inactivity: Do Current Measures Provide an Accurate View of “Sedentary” Video Game Time?

    Directory of Open Access Journals (Sweden)

    Simon Fullerton


    Full Text Available Background. Measures of screen time are often used to assess sedentary behaviour. Participation in activity-based video games (exergames can contribute to estimates of screen time, as current practices of measuring it do not consider the growing evidence that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Methods. Data were collected via a cross-sectional telephone survey in South Australia. Participants aged 18 years and above (n=2026 were asked about their video game habits, as well as demographic and socioeconomic factors. In cases where children were in the household, the video game habits of a randomly selected child were also questioned. Results. Overall, 31.3% of adults and 79.9% of children spend at least some time playing video games. Of these, 24.1% of adults and 42.1% of children play exergames, with these types of games accounting for a third of all time that adults spend playing video games and nearly 20% of children’s video game time. Conclusions. A substantial proportion of time that would usually be classified as “sedentary” may actually be spent participating in light to moderate physical activity.

  3. Bone mineral density measurements using peripheral quantitative computed tomography (pQCT). An evaluation of its clinical utility

    Energy Technology Data Exchange (ETDEWEB)

    Imai, Yoshiyuki [Kawasaki Medical School, Kurashiki, Okayama (Japan)


    Bone densitometry has become a major tool for the risk assessment of osteoporosis. Peripheral quantitative computed tomography (pQCT) has the potential to measure true volumetric bone mineral density (BMD, g/cm{sup 3}) separating cortical and trabecular BMD. The most widely used dual-energy X-ray absorptiometry (DXA) provides areal BMD (mg/cm{sup 2}). The purpose of this study was to clarify the clinical usefulness of pQCT as a method for bone mineral measurement. The pQCT measurements were carried out at the ultradistal- and mid-radius and the tibia using a Densiscan-1000 (Scanco Medical AG). In both sexes, radial and tibial BMDs in the elderly group (aged more than 60 y.o., 17 men, and 26 women) were significantly lower than those in the young group (aged 20-44 y.o., 107 men and 78 women). The percent difference between the two groups was the greatest in trabecular BMD (D50). As to the sex-related difference, the mean values of radial and tibial BMD in men were significantly higher than in women in elderly groups. The radial BMDs measured by pQCT correlated significantly with BMDs in the lumbar spine, radius and femoral neck measured by DXA (p<0.001). Lumbar BMD measured by DXA showed the highest correlation to rD50 measured by pQCT. Diagnostic ability of pQCT and DXA to detect osteoporosis was determined by comparing BMD measurements. Kappa statistics showed that in general the diagnostic agreement between these measurements was fair or moderate. The discriminative ability of these methods for vertebral fracture was assessed by receiver operating characteristic (ROC) analysis. The areas under the ROC curves were 0.68, 0.71, 0.69 and 0.78 for D50, D100, P100 and L-BMD, respectively. These results indicate that BMD measurements made by pQCT can provide information regarding both trabecular and cortical BMD, and that this method has potential for the diagnosis and management of osteoporosis. (author)

  4. Quantitative photoacoustic integrating sphere (QPAIS) platform for absorption coefficient and Gruneisen parameter measurements: Demonstration with human blood

    NARCIS (Netherlands)

    Villanueva, Y.Y.; Hondebrink, Erwin; Petersen, Wilhelmina; Steenbergen, Wiendelt


    Quantitative photoacoustic imaging in biomedicine relies on accurate measurements of relevant material properties of target absorbers. Here, we present a method for simultaneous measurements of the absorption coefficient and Grüneisen parameter of small volume of liquid scattering and absorbing

  5. Quantitation of contact allergy in guinea pigs by measuring changes in skin blood flow and skin fold thickness

    DEFF Research Database (Denmark)

    Andersen, Klaus Ejner; Staberg, B


    measurements when determined in 12 sham-treated guinea pigs. The LDF was maximal at 24 hours and the SFT at 48 hours. Before correlating the quantitative measurements with the conventional visual scoring in test and control animals the value from a nearby control site was subtracted from the test site values...

  6. Quantitative fluorescence kinetic analysis of NADH and FAD in human plasma using three- and four-way calibration methods capable of providing the second-order advantage

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Chao [School of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025 (China); Wu, Hai-Long, E-mail: [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China); Zhou, Chang; Xiang, Shou-Xia; Zhang, Xiao-Hua; Yu, Yong-Jie; Yu, Ru-Qin [State Key Laboratory of Chemo/Biosensing and Chemometrics, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082 (China)


    The metabolic coenzymes reduced nicotinamide adenine dinucleotide (NADH) and flavin adenine dinucleotide (FAD) are the primary electron donor and acceptor respectively, participate in almost all biological metabolic pathways. This study develops a novel method for the quantitative kinetic analysis of the degradation reaction of NADH and the formation reaction of FAD in human plasma containing an uncalibrated interferent, by using three-way calibration based on multi-way fluorescence technique. In the three-way analysis, by using the calibration set in a static manner, we directly predicted the concentrations of both analytes in the mixture at any time after the start of their reactions, even in the presence of an uncalibrated spectral interferent and a varying background interferent. The satisfactory quantitative results indicate that the proposed method allows one to directly monitor the concentration of each analyte in the mixture as the function of time in real-time and nondestructively, instead of determining the concentration after the analytical separation. Thereafter, we fitted the first-order rate law to their concentration data throughout their reactions. Additionally, a four-way calibration procedure is developed as an alternative for highly collinear systems. The results of the four-way analysis confirmed the results of the three-way analysis and revealed that both the degradation reaction of NADH and the formation reaction of FAD in human plasma fit the first-order rate law. The proposed methods could be expected to provide promising tools for simultaneous kinetic analysis of multiple reactions in complex systems in real-time and nondestructively. - Highlights: • A novel three-way calibration method for the quantitative kinetic analysis of NADH and FAD in human plasma is proposed. • The method can directly monitor the concentration of each analyte in the reaction in real-time and nondestructively. • The method has the second-order advantage. • A

  7. Measuring relative efficiency of applied science and technology universities in province of Semnan, Iran and providing suggestions for merging units

    Directory of Open Access Journals (Sweden)

    Abolfazl Danaei


    Full Text Available University of applied science and technology has been designed to create a platform for multilateral activities such as industrial, military and academic in developing countries to promote science and scientific research applications. These universities are responsible to promote practical training in quantitative and qualitative indicators and they provide appropriate infrastructure to implement theoretical graduates to solve practical problems to build necessary infrastructure to transfer modern technology into developing countries. During the past few years, there have been tremendous development on these units but some of them have not been efficient. In this paper, we present an empirical study to measure the relative efficiencies of various units of applied science and technology universities using data envelopment analysis. The proposed model of this paper uses two inputs including human resources as well as total assets and two outputs including the number of graduate students as well as operating profit. The results of the study have indicated that some of the units are inefficient and need to be merged with other units to increase the relative efficiency of these universities.

  8. Distance measures and optimization spaces in quantitative fatty acid signature analysis (United States)

    Bromaghin, Jeffrey F.; Rode, Karyn D.; Budge, Suzanne M.; Thiemann, Gregory W.


    Quantitative fatty acid signature analysis has become an important method of diet estimation in ecology, especially marine ecology. Controlled feeding trials to validate the method and estimate the calibration coefficients necessary to account for differential metabolism of individual fatty acids have been conducted with several species from diverse taxa. However, research into potential refinements of the estimation method has been limited. We compared the performance of the original method of estimating diet composition with that of five variants based on different combinations of distance measures and calibration-coefficient transformations between prey and predator fatty acid signature spaces. Fatty acid signatures of pseudopredators were constructed using known diet mixtures of two prey data sets previously used to estimate the diets of polar bears Ursus maritimus and gray seals Halichoerus grypus, and their diets were then estimated using all six variants. In addition, previously published diets of Chukchi Sea polar bears were re-estimated using all six methods. Our findings reveal that the selection of an estimation method can meaningfully influence estimates of diet composition. Among the pseudopredator results, which allowed evaluation of bias and precision, differences in estimator performance were rarely large, and no one estimator was universally preferred, although estimators based on the Aitchison distance measure tended to have modestly superior properties compared to estimators based on the Kullback-Leibler distance measure. However, greater differences were observed among estimated polar bear diets, most likely due to differential estimator sensitivity to assumption violations. Our results, particularly the polar bear example, suggest that additional research into estimator performance and model diagnostics is warranted.

  9. Validation of a new UNIX-based quantitative coronary angiographic system for the measurement of coronary artery lesions. (United States)

    Bell, M R; Britson, P J; Chu, A; Holmes, D R; Bresnahan, J F; Schwartz, R S


    We describe a method of validation of computerized quantitative coronary arteriography and report the results of a new UNIX-based quantitative coronary arteriography software program developed for rapid on-line (digital) and off-line (digital or cinefilm) analysis. The UNIX operating system is widely available in computer systems using very fast processors and has excellent graphics capabilities. The system is potentially compatible with any cardiac digital x-ray system for on-line analysis and has been designed to incorporate an integrated database, have on-line and immediate recall capabilities, and provide digital access to all data. The accuracy (mean signed differences of the observed minus the true dimensions) and precision (pooled standard deviations of the measurements) of the program were determined x-ray vessel phantoms. Intra- and interobserver variabilities were assessed from in vivo studies during routine clinical coronary arteriography. Precision from the x-ray phantom studies (6-In. field of view) for digital images was 0.066 mm and for digitized cine images was 0.060 mm. Accuracy was 0.076 mm (overestimation) for digital images compared to 0.008 mm for digitized cine images. Diagnostic coronary catheters were also used for calibration; accuracy.varied according to size of catheter and whether or not they were filled with iodinated contrast. Intra- and interobserver variabilities were excellent and indicated that coronary lesion measurements were relatively user-independent. Thus, this easy to use and very fast UNIX based program appears to be robust with optimal accuracy and precision for clinical and research applications.

  10. Quantitative investigation of the edge enhancement in in-line phase contrast projections and tomosynthesis provided by distributing microbubbles on the interface between two tissues: a phantom study (United States)

    Wu, Di; Donovan Wong, Molly; Li, Yuhua; Fajardo, Laurie; Zheng, Bin; Wu, Xizeng; Liu, Hong


    The objective of this study was to quantitatively investigate the ability to distribute microbubbles along the interface between two tissues, in an effort to improve the edge and/or boundary features in phase contrast imaging. The experiments were conducted by employing a custom designed tissue simulating phantom, which also simulated a clinical condition where the ligand-targeted microbubbles are self-aggregated on the endothelium of blood vessels surrounding malignant cells. Four different concentrations of microbubble suspensions were injected into the phantom: 0%, 0.1%, 0.2%, and 0.4%. A time delay of 5 min was implemented before image acquisition to allow the microbubbles to become distributed at the interface between the acrylic and the cavity simulating a blood vessel segment. For comparison purposes, images were acquired using three system configurations for both projection and tomosynthesis imaging with a fixed radiation dose delivery: conventional low-energy contact mode, low-energy in-line phase contrast and high-energy in-line phase contrast. The resultant images illustrate the edge feature enhancements in the in-line phase contrast imaging mode when the microbubble concentration is extremely low. The quantitative edge-enhancement-to-noise ratio calculations not only agree with the direct image observations, but also indicate that the edge feature enhancement can be improved by increasing the microbubble concentration. In addition, high-energy in-line phase contrast imaging provided better performance in detecting low-concentration microbubble distributions.

  11. Does the edge effect impact on the measure of spatial accessibility to healthcare providers? (United States)

    Gao, Fei; Kihal, Wahida; Le Meur, Nolwenn; Souris, Marc; Deguen, Séverine


    autocorrelation index and local indicators of spatial autocorrelation) are not really impacted. Our research has revealed minor accessibility variation when edge effect has been considered in a French context. No general statement can be set up because intensity of impact varies according to healthcare provider type, territorial organization and methodology used to measure the accessibility to healthcare. Additional researches are required in order to distinguish what findings are specific to a territory and others common to different countries. It constitute a promising direction to determine more precisely healthcare shortage areas and then to fight against social health inequalities.

  12. Quantitatively accurate activity measurements with a dedicated cardiac SPECT camera: Physical phantom experiments

    Energy Technology Data Exchange (ETDEWEB)

    Pourmoghaddas, Amir, E-mail:; Wells, R. Glenn [Physics Department, Carleton University, Ottawa, Ontario K1S 5B6, Canada and Cardiology, The University of Ottawa Heart Institute, Ottawa, Ontario K1Y4W7 (Canada)


    Purpose: Recently, there has been increased interest in dedicated cardiac single photon emission computed tomography (SPECT) scanners with pinhole collimation and improved detector technology due to their improved count sensitivity and resolution over traditional parallel-hole cameras. With traditional cameras, energy-based approaches are often used in the clinic for scatter compensation because they are fast and easily implemented. Some of the cardiac cameras use cadmium-zinc-telluride (CZT) detectors which can complicate the use of energy-based scatter correction (SC) due to the low-energy tail—an increased number of unscattered photons detected with reduced energy. Modified energy-based scatter correction methods can be implemented, but their level of accuracy is unclear. In this study, the authors validated by physical phantom experiments the quantitative accuracy and reproducibility of easily implemented correction techniques applied to {sup 99m}Tc myocardial imaging with a CZT-detector-based gamma camera with multiple heads, each with a single-pinhole collimator. Methods: Activity in the cardiac compartment of an Anthropomorphic Torso phantom (Data Spectrum Corporation) was measured through 15 {sup 99m}Tc-SPECT acquisitions. The ratio of activity concentrations in organ compartments resembled a clinical {sup 99m}Tc-sestamibi scan and was kept consistent across all experiments (1.2:1 heart to liver and 1.5:1 heart to lung). Two background activity levels were considered: no activity (cold) and an activity concentration 1/10th of the heart (hot). A plastic “lesion” was placed inside of the septal wall of the myocardial insert to simulate the presence of a region without tracer uptake and contrast in this lesion was calculated for all images. The true net activity in each compartment was measured with a dose calibrator (CRC-25R, Capintec, Inc.). A 10 min SPECT image was acquired using a dedicated cardiac camera with CZT detectors (Discovery NM530c, GE

  13. Quantitative skin color measurements in acanthosis nigricans patients: colorimetry and diffuse reflectance spectroscopy. (United States)

    Pattamadilok, Bensachee; Devpura, Suneetha; Syed, Zain U; Agbai, Oma N; Vemulapalli, Pranita; Henderson, Marsha; Rehse, Steven J; Mahmoud, Bassel H; Lim, Henry W; Naik, Ratna; Hamzavi, Iltefat H


    Tristimulus colorimetry and diffuse reflectance spectroscopy (DRS) are white-light skin reflectance techniques used to measure the intensity of skin pigmentation. The tristimulus colorimeter is an instrument that measures a perceived color and the DRS instrument measures biological chromophores of the skin, including oxy- and deoxyhemoglobin, melanin and scattering. Data gathered from these tools can be used to understand morphological changes induced in skin chromophores due to conditions of the skin or their treatments. The purpose of this study was to evaluate the use of these two instruments in color measurements of acanthosis nigricans (AN) lesions. Eight patients with hyperinsulinemia and clinically diagnosable AN were seen monthly. Skin pigmentation was measured at three sites: the inner forearm, the medial aspect of the posterior neck, and anterior neck unaffected by AN. Of the three, measured tristimulus L*a*b* color parameters, the luminosity parameter L* was found to most reliably distinguish lesion from normally pigmented skin. The DRS instrument was able to characterize a lesion on the basis of the calculated melanin concentration, though melanin is a weak indicator of skin change and not a reliable measure to be used independently. Calculated oxyhemoglobin and deoxyhemoglobin concentrations were not found to be reliable indicators of AN. Tristimulus colorimetry may provide reliable methods for respectively quantifying and characterizing the objective color change in AN, while DRS may be useful in characterizing changes in skin melanin content associated with this skin condition. © 2012 John Wiley & Sons A/S.

  14. Retrieving the Quantitative Chemical Information at Nanoscale from Scanning Electron Microscope Energy Dispersive X-ray Measurements by Machine Learning (United States)

    Jany, B. R.; Janas, A.; Krok, F.


    The quantitative composition of metal alloy nanowires on InSb(001) semiconductor surface and gold nanostructures on germanium surface is determined by blind source separation (BSS) machine learning (ML) method using non negative matrix factorization (NMF) from energy dispersive X-ray spectroscopy (EDX) spectrum image maps measured in a scanning electron microscope (SEM). The BSS method blindly decomposes the collected EDX spectrum image into three source components, which correspond directly to the X-ray signals coming from the supported metal nanostructures, bulk semiconductor signal and carbon background. The recovered quantitative composition is validated by detailed Monte Carlo simulations and is confirmed by separate cross-sectional TEM EDX measurements of the nanostructures. This shows that SEM EDX measurements together with machine learning blind source separation processing could be successfully used for the nanostructures quantitative chemical composition determination.

  15. Measurement of influenza virus-antibody reaction by quantitative electron microscopy. (United States)

    Silverman, L; Frommhagen, L H; Glick, D


    Measurement of the weight of individual virus particles from untreated and antibody-treated populations was made by quantitative electron microscopy. The weight of antibody bound depended on the concentration of antibody in solution. One population of viruses exposed to an antibody concentration which resulted in 95% inhibition of hemagglutination showed a mass increase of 55%, corresponding to an absolute increase of 9.0 x 10(-17) g in the median value. Another population, whose hemagglutination inhibition assay was 64%, showed a 39% increase in mass corresponding to an absolute median increase of 7.3 x 10(-17) g. The larger viruses in each population bound a greater absolute amount of antibody than did the smaller ones, but the latter bound relatively more antibody in proportion to their mass. No cross-reactivity was found between the antibody to influenza A/PR8 and the influenza strain B/LEE. Influenza A/PR8 controls exposed to nonspecific gamma-globulin displayed a significant weight loss, at least in part owing to loss from the core, as judged from the electron micrographs.

  16. Clinical measurement of Hepcidin-25 in human serum: Is quantitative mass spectrometry up to the job?

    Directory of Open Access Journals (Sweden)

    Constance Delaby


    Full Text Available From its discovery, hepcidin has generated many hopes in terms of diagnosis and management of a wide variety of iron-related diseases. However, in clinical use its accurate quantification remains a challenge due to the limited sensitivity, specificity or reproducibility of the techniques described. In this work, we adapted a highly specific and quantitative mass spectrometry method based on selected reaction monitoring (SRM to measure hepcidin. Our objective was to adapt the feasibility and reproducibility of the workflow to a clinical environment. Analytical validation was performed according to ISO 15189 norms for determining the limit of detection (LOD, 2 ng/mL, limit of quantification (LOQ, 6 ng/mL, repeatability, reproducibility and linearity (up to 200 ng/mL. Using the serum of patients with various iron-related diseases we compared our SRM detection method to the well-characterized competitive ELISA (cELISA test. The two methods were commutable (Bland–Altman plot and we found a positive and significant correlation (r2 = 0.96, Pearson correlation coefficient p < 0.001 between both methods, although the absolute concentration determined is different from factor 5. The validation of our SRM method encourages us to propose it as an alternative approach for accurate determination of hepcidin in human samples for clinical diagnosis, follow-up and management of iron-related diseases.

  17. Measuring Cerebral Blood Flow in Moyamoya Angiopathy by Quantitative Magnetic Resonance Angiography Noninvasive Optimal Vessel Analysis. (United States)

    Khan, Nadia; Lober, Robert M; Ostergren, Lauren; Petralia, Jacob; Bell-Stephens, Teresa; Navarro, Ramon; Feroze, Abdullah; Steinberg, Gary K


    Moyamoya disease causes progressive occlusion of the supraclinoidal internal carotid artery, and middle, anterior, and less frequently the posterior cerebral arteries, carrying the risk of stroke. Blood flow is often partially reconstituted by compensatory moyamoya collaterals and sometimes the posterior circulation. Cerebral revascularization can further augment blood flow. These changes to blood flow within the cerebral vessels, however, are not well characterized. To evaluate blood flow changes resulting from the disease process and revascularization surgery using quantitative magnetic resonance angiography with noninvasive optimal vessel analysis (NOVA). We retrospectively analyzed 190 preoperative and postoperative imaging scans in 66 moyamoya patients after revascularization surgery. Images were analyzed for blood flow using NOVA and compared with preoperative angiographic staging and postoperative blood flow. Blood flow rates within superficial temporal artery grafts were compared based on angiographic evidence of patency. Diseased vessels had lower blood flow, correlating with angiographic staging. Flow in posterior cererbal and basilar arteries increased with disease severity, particularly when both the anterior and middle cerebral arteries were occluded. Basilar artery flow and ipsilateral internal carotid artery flow decreased after surgery. Flow rates were different between angiographically robust and poor direct bypass grafts, as well as between robust and patent grafts. Preoperative changes in cerebral vessel flow as measured by NOVA correlated with angiographic disease progression. NOVA demonstrated that preoperative augmentation of the posterior circulation decreased after surgery. This report is the first to quantify the shift in collateral supply from the posterior circulation to the bypass graft.

  18. A study on the quantitative recovery of dissolved inorganic carbonates in ground water for radiocarbon measurement

    Energy Technology Data Exchange (ETDEWEB)

    Chun, Sang Ki; Woo, Hyung Joo; Cho, Soo Young; Kim, Nak Bae [Korea Institute of Geology Minning and Meterials, Taejon (Korea, Republic of); Lee, Jong Dae [Chungbuk Univ., Cheongju (Korea, Republic of)


    Dissolved inorganic carbonates in ground water were quantitatively by using gas evolution method. Gas evolution method was found to be less time-consuming, less susceptible to the contamination fromatmospheric CO{sub 2} and little affected by the sulfate ions in comparison to the direct precipitation method. Extraction efficiency of nearly 99% could be achieved by gas evolution method in two hours using recirculated gas at a sweeping rate of 4 liter per minute. Samples for carbon isotope fractionation study were collected in three fractions with collection times. The evolution time for the first fraction was one hours, and then second and third fractions were collected at intervals of 30 minutes, respectively. A small portion of each fraction was analyzed to evaluate {delta}{sup 13}C values, which were measured to be -7.9% ,-3.0% and +0.4% for the each fraction. The result clearly indicated that gas evolution method generates isotopically lighter carbon at the beginning of the purging process and heavier isotopes at the end. However, this isotope fractionation effect could be neglected by the almost complete recovery of carbonates.

  19. Quantitative measurement of CSF shunt flow and evaluation of shunt function in hydrocephalic patients

    Energy Technology Data Exchange (ETDEWEB)

    Ohya, M.; Tsugane, R.; Ito, M.; Nojiri, K.; Sato, O.; Ikei, K. (Tokai Univ., Isehara, Kanagawa (Japan). School of Medicine)


    Seventeen hydrocephalic children and adults with a variety of etiologies were studied. Recent data of CT scan, findings of flushing reservoir on digital palpation and their clinical pictures were also recorded. The flow rates were calculated as 0.03 - 0.33 ml/min when the shunting system appeared to be functioning properly and radionuclide imaging of time activity curves was expressed as smooth figures with peaks at the two regions of interest. In patients with the slit-like ventricle, the flow rates were expressed as 0.09 - 0.16 ml/min, however the palpation of the flushing reservoir suggested the malfunction of the shunt without refilling of the flushing reservoir in such a case. A hydrocephalic infant continued to have a tense fontanelle and head size remained unchanged after the V-P shunt with Pudenz high pressure valve had been installed. Radioactivity persisted for 15 min or more in the flushing reservoir after its introduction. Pumping maneuver of the flushing reservoir revealed a good CSF flow through the distal catheter. In this case, the shunt was patent but only poorly functioning due to the high pressure valve. Radioactivity was stayed in the injected site in the case of shunt obstruction. Reviewing these results, it is concluded that the quantitative measurement of the CSF shunt flow rates, with radionuclide imaging of time activity curves, makes it possible to evaluate more accurately the shunt patency and its functions.

  20. Weak-beam scanning transmission electron microscopy for quantitative dislocation density measurement in steels. (United States)

    Yoshida, Kenta; Shimodaira, Masaki; Toyama, Takeshi; Shimizu, Yasuo; Inoue, Koji; Yoshiie, Toshimasa; Milan, Konstantinovic J; Gerard, Robert; Nagai, Yasuyoshi


    To evaluate dislocations induced by neutron irradiation, we developed a weak-beam scanning transmission electron microscopy (WB-STEM) system by installing a novel beam selector, an annular detector, a high-speed CCD camera and an imaging filter in the camera chamber of a spherical aberration-corrected transmission electron microscope. The capabilities of the WB-STEM with respect to wide-view imaging, real-time diffraction monitoring and multi-contrast imaging are demonstrated using typical reactor pressure vessel steel that had been used in an European nuclear reactor for 30 years as a surveillance test piece with a fluence of 1.09 × 1020 neutrons cm-2. The quantitatively measured size distribution (average loop size = 3.6 ± 2.1 nm), number density of the dislocation loops (3.6 × 1022 m-3) and dislocation density (7.8 × 1013 m m-3) were carefully compared with the values obtained via conventional weak-beam transmission electron microscopy studies. In addition, cluster analysis using atom probe tomography (APT) further demonstrated the potential of the WB-STEM for correlative electron tomography/APT experiments. © The Author 2017. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail:

  1. A mass spectrometry-based assay for improved quantitative measurements of efflux pump inhibition.

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    Adam R Brown

    Full Text Available Bacterial efflux pumps are active transport proteins responsible for resistance to selected biocides and antibiotics. It has been shown that production of efflux pumps is up-regulated in a number of highly pathogenic bacteria, including methicillin resistant Staphylococcus aureus. Thus, the identification of new bacterial efflux pump inhibitors is a topic of great interest. Existing assays to evaluate efflux pump inhibitory activity rely on fluorescence by an efflux pump substrate. When employing these assays to evaluate efflux pump inhibitory activity of plant extracts and some purified compounds, we observed severe optical interference that gave rise to false negative results. To circumvent this problem, a new mass spectrometry-based method was developed for the quantitative measurement of bacterial efflux pump inhibition. The assay was employed to evaluate efflux pump inhibitory activity of a crude extract of the botanical Hydrastis Canadensis, and to compare the efflux pump inhibitory activity of several pure flavonoids. The flavonoid quercetin, which appeared to be completely inactive with a fluorescence-based method, showed an IC50 value of 75 μg/mL with the new method. The other flavonoids evaluated (apigenin, kaempferol, rhamnetin, luteolin, myricetin, were also active, with IC50 values ranging from 19 μg/mL to 75 μg/mL. The assay described herein could be useful in future screening efforts to identify efflux pump inhibitors, particularly in situations where optical interference precludes the application of methods that rely on fluorescence.

  2. Towards a Quantitative Performance Measurement Framework to Assess the Impact of Geographic Information Standards (United States)

    Vandenbroucke, D.; Van Orshoven, J.; Vancauwenberghe, G.


    Over the last decennia, the use of Geographic Information (GI) has gained importance, in public as well as in private sector. But even if many spatial data and related information exist, data sets are scattered over many organizations and departments. In practice it remains difficult to find the spatial data sets needed, and to access, obtain and prepare them for using in applications. Therefore Spatial Data Infrastructures (SDI) haven been developed to enhance the access, the use and sharing of GI. SDIs consist of a set of technological and non-technological components to reach this goal. Since the nineties many SDI initiatives saw light. Ultimately, all these initiatives aim to enhance the flow of spatial data between organizations (users as well as producers) involved in intra- and inter-organizational and even cross-country business processes. However, the flow of information and its re-use in different business processes requires technical and semantic interoperability: the first should guarantee that system components can interoperate and use the data, while the second should guarantee that data content is understood by all users in the same way. GI-standards within the SDI are necessary to make this happen. However, it is not known if this is realized in practice. Therefore the objective of the research is to develop a quantitative framework to assess the impact of GI-standards on the performance of business processes. For that purpose, indicators are defined and tested in several cases throughout Europe. The proposed research will build upon previous work carried out in the SPATIALIST project. It analyzed the impact of different technological and non-technological factors on the SDI-performance of business processes (Dessers et al., 2011). The current research aims to apply quantitative performance measurement techniques - which are frequently used to measure performance of production processes (Anupindi et al., 2005). Key to reach the research objectives

  3. Does Self-Citation Influence Quantitative Measures of Research Productivity Among Academic Oral and Maxillofacial Surgeons? (United States)

    Susarla, Srinivas M; Swanson, Edward W; Lopez, Joseph; Peacock, Zachary S; Dodson, Thomas B


    Quantitative measures of research productivity depend on the citation frequency of a publication. Citation-based metrics, such as the h-index (total number of publications h that have at least h citations), can be susceptible to self-citation, resulting in an inflated measure of research productivity. The purpose of the present study was to estimate the effect of self-citation on the h-index among academic oral and maxillofacial surgeons (OMSs). The present study was a cross-sectional study of full-time academic OMSs in the United States. The predictor variable was the frequency of self-citation. The primary outcome of interest was the h-index. Other study variables included demographic factors and citation metrics. Descriptive, bivariate, and regression statistics were computed. The study sample consisted of 325 full-time academic OMSs. Most surgeons were men (88.3%); approximately 40% had medical degrees. The study subjects had an average of 23.5 ± 37.1 publications. The mean number of self-citations was 15 + 56. The sample's mean h-index was 6.6 ± 7.6 and was associated with self-citation (r = 0.71, P citations. After adjusting for PhD degree, total number of publications, and academic rank, an increasing self-citation rate influenced the h-index (r = 0.006, P citations were more likely to have their h-index influenced by self-citation. Self-citation among full-time academic OMSs does not substantially affect the h-index. Surgeons in the top quartile of self-citation rates are more likely to influence their h-index. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

  4. A Quantitative Approach for Collocating NEON's Sensor-Based Ecological Measurements and in-situ Field Sampling and Observations (United States)

    Zulueta, R. C.; Metzger, S.; Ayres, E.; Luo, H.; Meier, C. L.; Barnett, D.; Sanclements, M.; Elmendorf, S.


    The National Ecological Observatory Network (NEON) is a continental-scale research platform currently in development to assess the causes of ecological change and biological responses to change across a projected 30-year timeframe. A suite of standardized sensor-based measurements (i.e., Terrestrial Instrument System (TIS) measurements) and in-situ field sampling and observations (i.e., Terrestrial Observation System (TOS) activities) will be conducted across 20 ecoclimatic domains in the U.S. where NEON is establishing 60 terrestrial research sites. NEON's TIS measurements and TOS activities are designed to observe the temporal and spatial dynamics of key drivers and ecological processes and responses to change within each of the 60 terrestrial research sites. The TIS measurements are non-destructive and designed to provide in-situ, continuous, and areally integrated observations of the surrounding ecosystem and environment, while TOS sampling and observation activities are designed to encompass a hierarchy of measurable biological states and processes including diversity, abundance, phenology, demography, infectious disease prevalence, ecohydrology, and biogeochemistry. To establish valid relationships between these drivers and site-specific responses, two contradicting requirements must be fulfilled: (i) both types of observations shall be representative of the same ecosystem, and (ii) they shall not significantly influence one another. Here we outline the theoretical background and algorithmic process for determining areas of mutual representativeness and exclusion around NEON's TIS measurements and develop a procedure which quantitatively optimizes this trade-off through: (i) quantifying the source area distributions of TIS measurements, (ii) determining the ratio of user-defined impact threshold to effective impact area for different TOS activities, and (iii) determining the range of feasible distances between TIS locations and TOS activities. This approach

  5. Quantitative RNFL attenuation coefficient measurements by RPE-normalized OCT data (United States)

    Vermeer, K. A.; van der Schoot, J.; Lemij, H. G.; de Boer, J. F.


    We demonstrate significantly different scattering coefficients of the retinal nerve fiber layer (RNFL) between normal and glaucoma subjects. In clinical care, SD-OCT is routinely used to assess the RNFL thickness for glaucoma management. In this way, the full OCT data set is conveniently reduced to an easy to interpret output, matching results from older (non- OCT) instruments. However, OCT provides more data, such as the signal strength itself, which is due to backscattering in the retinal layers. For quantitative analysis, this signal should be normalized to adjust for local differences in the intensity of the beam that reaches the retina. In this paper, we introduce a model that relates the OCT signal to the attenuation coefficient of the tissue. The average RNFL signal (within an A-line) was then normalized based on the observed RPE signal, resulting in normalized RNFL attenuation coefficient maps. These maps showed local defects matching those found in thickness data. The average (normalized) RNFL attenuation coefficient of a fixed band around the optic nerve head was significantly lower in glaucomatous eyes than in normal eyes (3.0mm-1 vs. 4.9mm-1, P<0.01, Mann-Whitney test).

  6. Preliminary evaluation of MRI-derived input function for quantitative measurement of glucose metabolism in an integrated PET-MRI

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    Anazodo, Udunna; Kewin, Matthew [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Finger, Elizabeth [Department of Clinical Neurological Sciences, Western University, London, Ontario (Canada); Thiessen, Jonathan; Hadway, Jennifer; Butler, John [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada); Pavlosky, William [Diagnostic Imaging, St Joseph' s Health Care, London, Ontario (Canada); Prato, Frank; Thompson, Terry; St Lawrence, Keith [Lawson Health Research Institute, Department of Medical Biophysics, Western University, London, Ontario (Canada)


    PET semi-quantitative methods such as relative uptake value can be robust but offer no biological information and do not account for intra-subject variability in tracer administration or clearance. Simultaneous multimodal measurements that combine PET and MRI not only permit crucial multiparametric measurements, it provides means of applying tracer kinetic modelling without the need for serial arterial blood sampling. In this study we adapted an image-derived input function (IDIF) method to improve characterization of glucose metabolism in an ongoing dementia study. Here we present preliminary results in a small group of frontotemporal dementia patients and controls. IDIF was obtained directly from dynamic PET data guided by regions of interest drawn on carotid vessels on high resolution T1-weighted MR Images. IDIF was corrected for contamination of non-arterial voxels. A validation of the method was performed in a porcine model in a PET-CT scanner comparing IDIF to direct arterial blood samples. Metabolic rate of glucose (CMRglc) was measured voxel-by-voxel in gray matter producing maps that were compared between groups. Net influx rate (Ki) and global mean CMRglc are reported. A good correlation (r = 0.9 p<0.0001) was found between corrected IDIF and input function measured from direct arterial blood sampling in the validation study. In 3 FTD and 3 controls, a trend towards hypometabolism was found in frontal, temporal and parietal lobes similar to significant differences previously reported by other groups. The global mean CMRglc and Ki observed in control subjects are in line with previous reports. In general, kinetic modelling of PET-FDG using an MR-IDIF can improve characterization of glucose metabolism in dementia. This method is feasible in multimodal studies that aim to combine PET molecular imaging with MRI as dynamic PET can be acquired along with multiple MRI measurements.

  7. Measuring factors that influence the utilisation of preventive care services provided by general practitioners in Australia

    Directory of Open Access Journals (Sweden)

    Oldenburg Brian


    Full Text Available Abstract Background Relatively little research attention has been given to the development of standardised and psychometrically sound scales for measuring influences relevant to the utilisation of health services. This study aims to describe the development, validation and internal reliability of some existing and new scales to measure factors that are likely to influence utilisation of preventive care services provided by general practitioners in Australia. Methods Relevant domains of influence were first identified from a literature review and formative research. Items were then generated by using and adapting previously developed scales and published findings from these. The new items and scales were pre-tested and qualitative feedback was obtained from a convenience sample of citizens from the community and a panel of experts. Principal Components Analyses (PCA and internal reliability testing (Cronbach's alpha were then conducted for all of the newly adapted or developed scales utilising data collected from a self-administered mailed survey sent to a randomly selected population-based sample of 381 individuals (response rate 65.6 per cent. Results The PCA identified five scales with acceptable levels of internal consistency were: (1 social support (ten items, alpha 0.86; (2 perceived interpersonal care (five items, alpha 0.87, (3 concerns about availability of health care and accessibility to health care (eight items, alpha 0.80, (4 value of good health (five items, alpha 0.79, and (5 attitudes towards health care (three items, alpha 0.75. Conclusion The five scales are suitable for further development and more widespread use in research aimed at understanding the determinants of preventive health services utilisation among adults in the general population.

  8. Failure to Integrate Quantitative Measurement Methods of Ocular Inflammation Hampers Clinical Practice and Trials on New Therapies for Posterior Uveitis. (United States)

    Herbort, Carl P; Tugal-Tutkun, Ilknur; Neri, Piergiorgio; Pavésio, Carlos; Onal, Sumru; LeHoang, Phuc


    Uveitis is one of the fields in ophthalmology where a tremendous evolution took place in the past 25 years. Not only did we gain access to more efficient, more targeted, and better tolerated therapies, but also in parallel precise and quantitative measurement methods developed allowing the clinician to evaluate these therapies and adjust therapeutic intervention with a high degree of precision. Objective and quantitative measurement of the global level of intraocular inflammation became possible for most inflammatory diseases with direct or spill-over anterior chamber inflammation, thanks to laser flare photometry. The amount of retinal inflammation could be quantified by using fluorescein angiography to score retinal angiographic signs. Indocyanine green angiography gave imaging insight into the hitherto inaccessible choroidal compartment, rendering possible the quantification of choroiditis by scoring indocyanine green angiographic signs. Optical coherence tomography has enabled measurement and objective monitoring of retinal and choroidal thickness. This multimodal quantitative appraisal of intraocular inflammation represents an exquisite security in monitoring uveitis. What is enigmatic, however, is the slow pace with which these improvements are integrated in some areas. What is even more difficult to understand is the fact that clinical trials to assess new therapeutic agents still mostly rely on subjective parameters such as clinical evaluation of vitreous haze as a main endpoint; whereas a whole array of precise, quantitative, and objective modalities are available for the design of clinical studies. The scope of this work was to review the quantitative investigations that improved the management of uveitis in the past 2-3 decades.

  9. The Impact of Quantitative Data Provided by a Multi-spectral Digital Skin Lesion Analysis Device on Dermatologists'Decisions to Biopsy Pigmented Lesions. (United States)

    Farberg, Aaron S; Winkelmann, Richard R; Tucker, Natalie; White, Richard; Rigel, Darrell S


    BACKGROUND: Early diagnosis of melanoma is critical to survival. New technologies, such as a multi-spectral digital skin lesion analysis (MSDSLA) device [MelaFind, STRATA Skin Sciences, Horsham, Pennsylvania] may be useful to enhance clinician evaluation of concerning pigmented skin lesions. Previous studies evaluated the effect of only the binary output. OBJECTIVE: The objective of this study was to determine how decisions dermatologists make regarding pigmented lesion biopsies are impacted by providing both the underlying classifier score (CS) and associated probability risk provided by multi-spectral digital skin lesion analysis. This outcome was also compared against the improvement reported with the provision of only the binary output. METHODS: Dermatologists attending an educational conference evaluated 50 pigmented lesions (25 melanomas and 25 benign lesions). Participants were asked if they would biopsy the lesion based on clinical images, and were asked this question again after being shown multi-spectral digital skin lesion analysis data that included the probability graphs and classifier score. RESULTS: Data were analyzed from a total of 160 United States board-certified dermatologists. Biopsy sensitivity for melanoma improved from 76 percent following clinical evaluation to 92 percent after quantitative multi-spectral digital skin lesion analysis information was provided ( p lesion analysis (64% vs. 86%, p lesions led to both increased sensitivity and specificity, thereby resulting in more accurate biopsy decisions.


    Directory of Open Access Journals (Sweden)

    Monika Vaitkevičiūtė


    Full Text Available If single refugees do not belong to any groups of vulnerable persons, the support for their integration in municipality of lasts 12 months. After this period, people begin an independent life in Lithuanian society. However, not all single refugees manage successfully to do this. The aim of the research is to reveal the need for continuity of the integration measures provided for single refugees in municipalities. The qualitative research was made using semi-structured interviewing. The participants of the study are five social workers, who work in non-governmental organizations and mentoring refugee integration processes in the municipalities. The study results suggest that support period for integration in the municipality is too short. The needs of single foreigners are the least satisfied when learning Lithuanian language, trying to establish themselves in the labour market, gaining professional skills or acquiring qualification, and renting a place to live in. In these contexts, single refugees face discrimination, bullying, language barrier, ignorance and lack of information, experience financial difficulties or even social exclusion. During integration, single refugees have the least difficulties with the healthcare system. Such process and not satisfied psycho-emotional needs encourage the emigration of single refugees. In order to successfully integrate people into Lithuanian society it is necessary to individualize the program, taking into account the particular experiences, abilities, needs of individuals as well as educating professionals of public services.

  11. In situ biodeposition measurements on a Modiolus modiolus (horse mussel) reef provide insights into ecosystem services (United States)

    Kent, Flora E. A.; Last, Kim S.; Harries, Daniel B.; Sanderson, William G.


    Horse mussel (Modiolus modiolus) shellfish reefs are a threatened and declining habitat in the North East Atlantic and support high levels of biodiversity. Shellfish can influence the surrounding water column and modify the quality of material that reaches the seabed by filtering water, actively depositing particles and changing the benthic boundary layer due to surface roughness. In the present study M. modiolus biodeposition was measured in a field location for the first time. The results show that M. modiolus enhance sedimentation and contribute to the downward flux of material to the seabed. Approximately 30% of the total sediment deposition was attributed to active filter feeding and overall, the presence of horse mussels enhanced deposition two fold. The results are discussed in terms of the potential for horse mussel reefs to provide ecosystem services to society, through functions such as benthopelagic coupling and sediment stabilisation. Highlighting the societal benefits supplied by marine habitats can help prioritise conservation efforts and feed into the sustainable management of coastal water bodies.

  12. Quantitative MRI for hepatic fat fraction and T2* measurement in pediatric patients with non-alcoholic fatty liver disease

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Jie; Rigsby, Cynthia K.; Donaldson, James S. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States); Northwestern University, Department of Radiology, Feinberg School of Medicine, Chicago, IL (United States); Fishbein, Mark H. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Division of Gastroenterology, Hepatology, and Nutrition, Chicago, IL (United States); Zhang, Gang [Ann and Robert H. Lurie Children' s Hospital of Chicago, Biostatistics Research Core, Chicago, IL (United States); Schoeneman, Samantha E. [Ann and Robert H. Lurie Children' s Hospital of Chicago, Department of Medical Imaging, Chicago, IL (United States)


    Non-alcoholic fatty liver disease (NAFLD) is the most common cause of chronic liver disease in children. The gold standard for diagnosis is liver biopsy. MRI is a non-invasive imaging method to provide quantitative measurement of hepatic fat content. The methodology is particularly appealing for the pediatric population because of its rapidity and radiation-free imaging techniques. To develop a multi-point Dixon MRI method with multi-interference models (multi-fat-peak modeling and bi-exponential T2* correction) for accurate hepatic fat fraction (FF) and T2* measurements in pediatric patients with NAFLD. A phantom study was first performed to validate the accuracy of the MRI fat fraction measurement by comparing it with the chemical fat composition of the ex-vivo pork liver-fat homogenate. The most accurate model determined from the phantom study was used for fat fraction and T2* measurements in 52 children and young adults referred from the pediatric hepatology clinic with suspected or identified NAFLD. Separate T2* values of water (T2*{sub W}) and fat (T2*{sub F}) components derived from the bi-exponential fitting were evaluated and plotted as a function of fat fraction. In ten patients undergoing liver biopsy, we compared histological analysis of liver fat fraction with MRI fat fraction. In the phantom study the 6-point Dixon with 5-fat-peak, bi-exponential T2* modeling demonstrated the best precision and accuracy in fat fraction measurements compared with other methods. This model was further calibrated with chemical fat fraction and applied in patients, where similar patterns were observed as in the phantom study that conventional 2-point and 3-point Dixon methods underestimated fat fraction compared to the calibrated 6-point 5-fat-peak bi-exponential model (P < 0.0001). With increasing fat fraction, T2*{sub W} (27.9 ± 3.5 ms) decreased, whereas T2*{sub F} (20.3 ± 5.5 ms) increased; and T2*{sub W} and T2*{sub F} became increasingly more similar when fat

  13. The importance of sensory-motor control in providing core stability: implications for measurement and training. (United States)

    Borghuis, Jan; Hof, At L; Lemmink, Koen A P M


    Although the hip musculature is found to be very important in connecting the core to the lower extremities and in transferring forces from and to the core, it is proposed to leave the hip musculature out of consideration when talking about the concept of core stability. A low level of co-contraction of the trunk muscles is important for core stability. It provides a level of stiffness, which gives sufficient stability against minor perturbations. Next to this stiffness, direction-specific muscle reflex responses are also important in providing core stability, particularly when encountering sudden perturbations. It appears that most trunk muscles, both the local and global stabilization system, must work coherently to achieve core stability. The contributions of the various trunk muscles depend on the task being performed. In the search for a precise balance between the amount of stability and mobility, the role of sensory-motor control is much more important than the role of strength or endurance of the trunk muscles. The CNS creates a stable foundation for movement of the extremities through co-contraction of particular muscles. Appropriate muscle recruitment and timing is extremely important in providing core stability. No clear evidence has been found for a positive relationship between core stability and physical performance and more research in this area is needed. On the other hand, with respect to the relationship between core stability and injury, several studies have found an association between a decreased stability and a higher risk of sustaining a low back or knee injury. Subjects with such injuries have been shown to demonstrate impaired postural control, delayed muscle reflex responses following sudden trunk unloading and abnormal trunk muscle recruitment patterns. In addition, various relationships have been demonstrated between core stability, balance performance and activation characteristics of the trunk muscles. Most importantly, a significant


    Directory of Open Access Journals (Sweden)



    Full Text Available Lecturers are fully occupied with many tasks including preparing teaching materials, exam papers, lab sheets, markings, research, and administrative support tasks required of them to maintain high standard teaching delivery and good quality management system in the school. Aside from these, they are now required to do intensive Outcome-Based Education (OBE assessments, and Continual Quality Improvement (CQI planning and implementation. An automated OBE assessment tool is therefore required to ease the burden among the lecturers and provide a standard method of assessment. To assist in this process, this paper presents a blueprint of a software-enabled quantitative measurement of the Learning Outcomes (LO and the Programme Outcomes (PO in the module level. The blueprint consists of macro-enabled worksheets that automatically calculate the students’ individual LO and PO attainments based on their respective module assessment marks whereby the lecturer only need to key-in the subject details of assessments-LO mapping, LO-PO mapping and the students’ assessment marks. Once the marks are in place, LO and PO attainments are calculated automatically to provide the corresponding bar charts based on the individual attainments of the students. A LO or a PO is said to be attained when the number of students achieved the Key Performance Index (KPI set by the department. The results will then be used by the lecturer to prepare an annual module review and prepare a CQI plan for the next semester.

  15. Measuring in action research : four ways of integrating quantitative methods in participatory dynamics


    Martí Olivé, Joel


    Background of INCASI Project H2020-MSCA-RISE-2015 GA 691004. WP1: Compilation Although action research uses both qualitative and quantitative methods, few contributions have addressed the specific role of the latter in this kind of research. This paper focuses on how quantitative methods can be integrated with participatory dynamics in action research designs. Four types of integration are defined and exemplified. The paper concludes with some reflections on how the integration of quantita...

  16. The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way. (United States)

    Johannsen, Gunnar; Tellefsen, Georg; Johannsen, Annsofi; Liljeborg, Anders


    To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively. Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface roughness value (Ra-value) and also a volume loss value were calculated from the profilometer measurements. These values were then correlated to each other. An unpaired t-test for the difference in the abrasion values between the toothpastes and the abrasion values over time was used. The polishing paste RDA® 170 yielded higher Ra-values than RDA 250®, both after 1 and 6 h of brushing (1.01 ± 0.22 and 8.99 ± 1.55 compared to 0.63 ± 0.26 and 7.83 ± 5.89, respectively) as well as volume loss values (3.71 ± 0.17 and 20.20 ± 2.41 compared to 2.15 ± 1.41 and 14.79 ± 11.76, respectively), thus poor correlations between the RDA and Ra and Volume loss values were shown. Among the toothpastes, Apotekets® showed the highest Ra value after 1 h of brushing and Pepsodent® whitening after 6 h of brushing. Pepsodent® whitening also showed the highest volume loss values, both after 1 and 6 h of brushing. This study emphasizes the importance of not only considering the RDA value, but also a roughness value, when describing the abrasivity of a toothpaste. Furthermore, it can be concluded that so called 'whitening' toothpastes do not necessarily have a higher abrasive effect than other toothpastes.

  17. Quantitative analysis of facial palsy using a three-dimensional facial motion measurement system. (United States)

    Katsumi, Sachiyo; Esaki, Shinichi; Hattori, Koosuke; Yamano, Koji; Umezaki, Taizo; Murakami, Shingo


    The prognosis for facial nerve palsy (FNP) depends on its severity. Currently, many clinicians use the Yanagihara, House-Brackmann, and/or Sunnybrook grading systems to assess FNP. Although these assessments are performed by experts, inter- and intra-observer disagreements have been demonstrated. The quantitative and objective analyses of the degree of FNP would be preferred to monitor functional changes and to plan and evaluate therapeutic interventions in patients with FNP. Numerous two-dimensional (2-D) assessments have been proposed, however, the limitations of 2-D assessment have been reported. The purpose of this study was to introduce a three-dimensional (3-D) image generation system for the analysis of facial nerve palsy (FNP) and to show the correlation between the severity of FNP assessed by this method and two conventional systems. Five independent facial motions, resting, eyebrow raise, gentle eye closure, full smile with lips open and whistling were recorded with our system and the images were then analyzed using our software. The regional and gross facial symmetries were analyzed. The predicted scores were calculated and compared to the Yanagihara and H-B grading scores. We analyzed 15 normal volunteers and 42 patients with FNP. The results showed that 3-D analysis could measure mouth movement in the anteroposterior direction, whereas two-dimensional analysis could not. The system results showed good correlation with the clinical results from the Yanagihara (r(2)=0.86) and House-Brackmann (r(2)=0.81) grading scales. This objective method can produce consistent results that align with two conventional systems. Therefore, this method is ideally suited for use in a routine clinical setting. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  18. Absolute choline concentration measured by quantitative proton MR spectroscopy correlates with cell density in meningioma

    Energy Technology Data Exchange (ETDEWEB)

    Yue, Qiang [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan)]|[West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China); Shibata, Yasushi; Kawamura, Hiraku; Matsumura, Akira [University of Tsukuba, Department of Neurosurgery, Institute of Clinical Medicine, Tsukuba Science City, Ibaraki (Japan); Isobe, Tomonori [Kitasato University, Department of Medical Technology, School of Allied Health Sciences, Minato, Tokyo (Japan); Anno, Izumi [University of Tsukuba, Department of Radiology, Institute of Clinical Medicine, Tsukuba, Ibaraki (Japan); Gong, Qi-Yong [West China Hospital of Sichuan University, Huaxi MR Research Center, Department of Radiology, Chengdu (China)]|[University of Liverpool, Division of Medical Imaging, Faculty of Medicine, Liverpool (United Kingdom)


    This study was aimed to investigate the relationship between quantitative proton magnetic resonance spectroscopy (1H-MRS) and pathological changes in meningioma. Twenty-two meningioma cases underwent single voxel 1H-MRS (point-resolved spectroscopy sequence, repetition time/echo time = 2,000 ms/68, 136, 272 ms). Absolute choline (Cho) concentration was calculated using tissue water as the internal reference and corrected according to intra-voxel cystic/necrotic parts. Pathological specimens were stained with MIB-1 antibody to measure cell density and proliferation index. Correlation analysis was performed between absolute Cho concentration and cell density and MIB-1 labeled proliferation index. Average Cho concentration of all meningiomas before correction was 2.95 {+-} 0.86 mmol/kg wet weight. It was increased to 3.23 {+-} 1.15 mmol/kg wet weight after correction. Average cell density of all meningiomas was 333 {+-} 119 cells/HPF, and average proliferation index was 2.93 {+-} 5.72%. A linear, positive correlation between cell density and Cho concentration was observed (r = 0.650, P = 0.001). After correction of Cho concentration, the correlation became more significant (r = 0.737, P < 0.001). However, no significant correlation between Cho concentration and proliferation index was found. There seemed to be a positive correlation trend after correction of Cho concentration but did not reach significant level. Absolute Cho concentration, especially Cho concentration corrected according to intra-voxel cystic/necrotic parts, reflects cell density of meningioma. (orig.)

  19. Statistical evaluation of an improved quantitative immunofluorescence method of measuring serum antibody levels directed against intestinal bacteria

    NARCIS (Netherlands)

    Jansen, G.J.; Wilkinson, M.H.F.; Deddens, B.; Waaij, D. van der

    The accuracy of an improved quantitative immunofluorescence method to measure the antibody binding capacity of intestinal bacteria was assessed. The improvements comprise: calibration on a non-fading fluorescence standard (uranyl glass), prolonged camera exposure time (over 4 s) and shading

  20. Quantitative estimation of the influence of external vibrations on the measurement error of a coriolis mass-flow meter

    NARCIS (Netherlands)

    van de Ridder, Bert; Hakvoort, Wouter; van Dijk, Johannes; Lötters, Joost Conrad; de Boer, Andries; Dimitrovova, Z.; de Almeida, J.R.


    In this paper the quantitative influence of external vibrations on the measurement value of a Coriolis Mass-Flow Meter for low flows is investigated, with the eventual goal to reduce the influence of vibrations. Model results are compared with experimental results to improve the knowledge on how

  1. Effect of physiological heart rate variability on quantitative T2 measurement with ECG-gated Fast Spin Echo (FSE) sequence and its retrospective correction. (United States)

    de Roquefeuil, Marion; Vuissoz, Pierre-André; Escanyé, Jean-Marie; Felblinger, Jacques


    Quantitative T2 measurement is applied in cardiac Magnetic Resonance Imaging (MRI) for the diagnosis and follow-up of myocardial pathologies. Standard Electrocardiogram (ECG)-gated fast spin echo pulse sequences can be used clinically for T2 assessment, with multiple breath-holds. However, heart rate is subject to physiological variability, which causes repetition time variations and affects the recovery of longitudinal magnetization between TR periods. The bias caused by heart rate variability on quantitative T2 measurements is evaluated for fast spin echo pulse sequence. Its retrospective correction based on an effective TR is proposed. Heart rate variations during breath-holds are provided by the ECG recordings from healthy volunteers. T2 measurements were performed on a phantom with known T2 values, by synchronizing the sequence with the recorded ECG. Cardiac T2 measurements were performed twice on six volunteers. The impact of T1 on T2 is also studied. Maximum error in T2 is 26% for phantoms and 18% for myocardial measurement. It is reduced by the proposed compensation method to 20% for phantoms and 10% for in vivo measurements. Only approximate knowledge of T1 is needed for T2 correction. Heart rate variability may cause a bias in T2 measurement with ECG-gated FSE. It needs to be taken into account to avoid a misleading diagnosis from the measurements. © 2013.

  2. A quantitative approach to measure women?s sexual function using electromyography: A preliminary study of the Kegel exercise


    Mohktar, Mas Sahidayana; Ibrahim, Fatimah; Rozi, Nur Farahana Mohd; Yusof, Juhaida Mohd; Ahmad, Siti Anom; Yen, Khong Su; Omar, Siti Zawiah


    Background Currently, the reference standard used to clinically assess sexual function among women is a qualitative questionnaire. Hence, a generalised and quantitative measurement tool needs to be available as an alternative. This study investigated whether an electromyography (EMG) measurement tecnique could be used to help quantify women?s sexual function. Material/Methods A preliminary intervention study was conducted on 12 female subjects, who were randomised into a control (n=6) and an ...

  3. An improved method for quantitatively measuring the sequences of total organic carbon and black carbon in marine sediment cores (United States)

    Xu, Xiaoming; Zhu, Qing; Zhou, Qianzhi; Liu, Jinzhong; Yuan, Jianping; Wang, Jianghai


    Understanding global carbon cycle is critical to uncover the mechanisms of global warming and remediate its adverse effects on human activities. Organic carbon in marine sediments is an indispensable part of the global carbon reservoir in global carbon cycling. Evaluating such a reservoir calls for quantitative studies of marine carbon burial, which closely depend on quantifying total organic carbon and black carbon in marine sediment cores and subsequently on obtaining their high-resolution temporal sequences. However, the conventional methods for detecting the contents of total organic carbon or black carbon cannot resolve the following specific difficulties, i.e., (1) a very limited amount of each subsample versus the diverse analytical items, (2) a low and fluctuating recovery rate of total organic carbon or black carbon versus the reproducibility of carbon data, and (3) a large number of subsamples versus the rapid batch measurements. In this work, (i) adopting the customized disposable ceramic crucibles with the micropore-controlled ability, (ii) developing self-made or customized facilities for the procedures of acidification and chemothermal oxidization, and (iii) optimizing procedures and carbon-sulfur analyzer, we have built a novel Wang-Xu-Yuan method (the WXY method) for measuring the contents of total organic carbon or black carbon in marine sediment cores, which includes the procedures of pretreatment, weighing, acidification, chemothermal oxidation and quantification; and can fully meet the requirements of establishing their highresolution temporal sequences, whatever in the recovery, experimental efficiency, accuracy and reliability of the measurements, and homogeneity of samples. In particular, the usage of disposable ceramic crucibles leads to evidently simplify the experimental scenario, which further results in the very high recovery rates for total organic carbon and black carbon. This new technique may provide a significant support for

  4. In vitro assessment of a new algorithm for quantitative echo measurement of heart valve regurgitant jet (United States)

    Grigioni, Mauro; Tonti, Gianni; Pedrizzetti, Gianni; Daniele, Carla; D'Avenio, Giuseppe


    The measure of the regurgitant flow through heart valves provides an indication of the severity of the valve closure dysfunction with diagnostic relevance. The estimation of the volume passing through the closed valve during systole, and its ratio with the ejection volume, can significantly improve the assessment of an ongoing valvular pathology. The noninvasive quantification of flow converging to the valve is still lacking a satisfying degree of precision. The most popular technique is the Proximal Isovelocity Surface Area (PISA), which assumes that, in the flow field upstream of the valve, the surfaces corresponding to the same velocity are spherical, whence the regurgitant flow is estimated by multiplication with the hemispherical surface area. In the present study, a new method is proposed of color Doppler echocardiography image processing, for regurgitant flow measurements. In this method, called Proximal Arbitrary Surface Conservative Assessment of Leakage (PASCAL), the laws of fluid dynamics are used to reconstruct the entire flow field, in the hypothesis of axial symmetry, starting from the echographic Doppler mapping of one component of velocity. In vitro experiments have confirmed that the new method provides better flow estimates than PISA, on account of its more rigorous physical model of the regurgitant flow.

  5. Quantitative Analysis of the Usage of a Pedagogical Tool Combining Questions Listed as Learning Objectives and Answers Provided as Online Videos

    Directory of Open Access Journals (Sweden)

    Odette Laneuville


    Full Text Available To improve the learning of basic concepts in molecular biology of an undergraduate science class, a pedagogical tool was developed, consisting of learning objectives listed at the end of each lecture and answers to those objectives made available as videos online. The aim of this study was to determine if the pedagogical tool was used by students as instructed, and to explore students’ perception of its usefulness. A combination of quantitative survey data and measures of online viewing was used to evaluate the usage of the pedagogical practice. A total of 77 short videos linked to 11 lectures were made available to 71 students, and 64 completed the survey. Using online tracking tools, a total of 7046 views were recorded. Survey data indicated that most students (73.4% accessed all videos, and the majority (98.4% found the videos to be useful in assisting their learning. Interestingly, approximately half of the students (53.1% always or most of the time used the pedagogical tool as recommended, and consistently answered the learning objectives before watching the videos. While the proposed pedagogical tool was used by the majority of students outside the classroom, only half used it as recommended limiting the impact on students’ involvement in the learning of the material presented in class.

  6. Quantitative relationships between huntingtin levels, polyglutamine length, inclusion body formation, and neuronal death provide novel insight into Huntington’s disease molecular pathogenesis (United States)

    Miller, Jason; Arrasate, Montserrat; Shaby, Benjamin A.; Mitra, Siddhartha; Masliah, Eliezer; Finkbeiner, Steven


    An expanded polyglutamine (polyQ) stretch in the protein huntingtin (htt) induces self-aggregation into inclusion bodies (IBs) and causes Huntington’s disease (HD). Defining precise relationships between early observable variables and neuronal death at the molecular and cellular levels should improve our understanding of HD pathogenesis. Here, we utilized an automated microscope that can track thousands of neurons individually over their entire lifetime to quantify interconnected relationships between early variables, such as htt levels, polyQ length, and IB formation, and neuronal death in a primary striatal model of HD. The resulting model revealed that: mutant htt increases the risk of death by tonically interfering with homeostatic coping mechanisms rather than producing accumulated damage to the neuron; htt toxicity is saturable; the rate limiting steps for inclusion body formation and death can be traced to different conformational changes in monomeric htt; and IB formation reduces the impact of a neuron’s starting levels of htt on its risk of death. Finally, the model that emerges from our quantitative measurements places critical limits on the potential mechanisms by which mutant htt might induce neurodegeneration, which should help direct future research. PMID:20685997

  7. Measuring Physical Inactivity: Do Current Measures Provide an Accurate View of “Sedentary” Video Game Time?

    National Research Council Canada - National Science Library

    Simon Fullerton; Anne W. Taylor; Eleonora Dal Grande; Narelle Berry


    ... that playing exergames can provide light to moderate levels of physical activity. This study aimed to determine what proportion of time spent playing video games was actually spent playing exergames. Methods...

  8. Colorimetry provides a rapid objective measurement of de novo hair growth rate in mice. (United States)

    Tzung, Tien-Yi; Yang, Chia-Yi; Huang, Yung-Chang; Kao, Fu-Jen


    Depilated mice have been used as a test platform for hair growth-regulating agents. However, currently available assessment tools for hair growth in mice are less than ideal. Tristimulus colorimetry of the fur color of depilated agouti, albino, and black mice with L*, a*, and b* values were performed daily until the full growth of pelage. Using light-emitting diode (LED) irradiation (650 and 890 nm) with a daily dose of 3.5 J/cm(2) as hair growth regulators, the hair growth rates observed by the global assessment were compared with those derived from colorimetry. In contrast to a* and b* values, L* values changed more drastically over time in the anagen phase regardless of fur color. Unlike the inhibitory effect of 650 nm irradiation, LED of 890 nm promoted de novo hair regrowth in mice. The difference in hair growth rates detected by colorimetry paralleled the observation made by the global assessment. The L* value of fur color obtained by tristimulus colorimetry was a sensitive yet quantitative indicator of de novo hair growth, and could be used to project the hair growth rate in mice.

  9. Quantitative measurements of the articular areas of mandibular condyles with temporomandibular joint disorders using magnetic resonance imaging. (United States)

    Kohi, Kaori; Igarashi, Chinami; Sugisaki, Masashi; Osano, Takashi; Sato, Yohei; Kobayashi, Kaoru; Ohkubo, Chikahiro


    The authors sought to clarify the variation in the condylar anterior functional surface (AFS) of patients with temporomandibular joint (TMJ) disorders using quantitative measurements by magnetic resonance imaging (MRI). MR images of 68 joints (2 males, 32 females) were used. The subjects were classified into three groups: with/without defects of cortical bone groups and a combination group without defects. The AFS was measured as the length between the protrusive point and the apex of the condyle on MRI (4-mm-thick slices), and the quad value of the length was defined as the area on the slice. The summed quad values of all slices were used as the AFS area. Differences in the areas among the three groups were compared by one-way analysis of variance (ANOVA). The non-defect group had significantly larger AFS areas than the defect group. Quantitative measurement on MR images clarified the changes in the condylar sagittal appearance.

  10. Dominance in Domestic Dogs : A Quantitative Analysis of Its Behavioural Measures

    NARCIS (Netherlands)

    van der Borg, Joanne A M; Schilder, Matthijs B H; Vinke, Claudia M; de Vries, Han


    A dominance hierarchy is an important feature of the social organisation of group living animals. Although formal and/or agonistic dominance has been found in captive wolves and free-ranging dogs, applicability of the dominance concept in domestic dogs is highly debated, and quantitative data are

  11. Quantitative Measurement of Text Difficulty: What's the Use? (United States)

    Cunningham, James W.; Mesmer, Heidi Anne


    Common Core Reading Standard 10 not only prescribes the difficulty of texts students should become able to read, but also the difficulty diet of texts schools should ask their students to read across the school year. The use of quantitative text-assessment tools in the implementation of this standard warrants an examination into the validity of…

  12. System and Method for Providing Vertical Profile Measurements of Atmospheric Gases (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — A system and method for using an air collection device to collect a continuous air sample as the device descends through the atmosphere are provided. The air...

  13. A family-specific use of the Measure of Processes of Care for Service Providers (MPOC-SP)

    NARCIS (Netherlands)

    Siebes, R. C.; Nijhuis, B. J. G.; Boonstra, A. M.; Ketelaar, M.; Wijnroks, L.; Reinders-Messelink, H. A.; Postema, K.; Vermeer, A.

    Objective: To examine the validity and utility of the Dutch Measure of Processes of Care for Service Providers (MPOC-SP) as a family-specific measure. Design: A validation study. Setting: Five paediatric rehabilitation settings in the Netherlands. Main measures: The MPOC-SP was utilized in a general

  14. Quantitative measurements of dielectrophoresis in a nanoscale electrode array with an atomic force microscopy (United States)

    Froberg, James; Jayasooriya, Vidura; You, Seungyong; Nawarathna, Dharmakeerthi; Choi, Yongki


    Nanoelectronic devices integrated with dielectrophoresis (DEP) have been promoted as promising platforms for trapping, separating, and concentrating target biomarkers and cancer cells from a complex medium. Here, we visualized DEP and DEP gradients in conventional nanoelectronic devices by using multi-pass atomic force microcopy techniques. Our measurements directly demonstrated a short range DEP only at sharp step edges of electrodes, frequency dependent DEP polarity, and separation distance dependent DEP strength. Additionally, non-uniform DEP along the edges of the electrodes due to a large variation in electric field strength was observed. The strength and apparent working distance of DEP were measured to be an order of a few nN and 80 nm within the limited scale of particles and other parameters such as an ionic strength of the medium. This method provides a powerful tool to quantify the strength and polarity of DEP and allows optimizing and calibrating the device's operating parameters including the driving field strength for the effective control and manipulation of target biomolecules.

  15. A Highly Flexible, Automated System Providing Reliable Sample Preparation in Element- and Structure-Specific Measurements. (United States)

    Vorberg, Ellen; Fleischer, Heidi; Junginger, Steffen; Liu, Hui; Stoll, Norbert; Thurow, Kerstin


    Life science areas require specific sample pretreatment to increase the concentration of the analytes and/or to convert the analytes into an appropriate form for the detection and separation systems. Various workstations are commercially available, allowing for automated biological sample pretreatment. Nevertheless, due to the required temperature, pressure, and volume conditions in typical element and structure-specific measurements, automated platforms are not suitable for analytical processes. Thus, the purpose of the presented investigation was the design, realization, and evaluation of an automated system ensuring high-precision sample preparation for a variety of analytical measurements. The developed system has to enable system adaption and high performance flexibility. Furthermore, the system has to be capable of dealing with the wide range of required vessels simultaneously, allowing for less cost and time-consuming process steps. However, the system's functionality has been confirmed in various validation sequences. Using element-specific measurements, the automated system was up to 25% more precise compared to the manual procedure and as precise as the manual procedure using structure-specific measurements. © 2015 Society for Laboratory Automation and Screening.

  16. Field experiment provides ground truth for surface nuclear magnetic resonance measurement (United States)

    Knight, R.; Grunewald, E.; Irons, T.; Dlubac, K.; Song, Y.; Bachman, H.N.; Grau, B.; Walsh, D.; Abraham, J.D.; Cannia, J.


    The need for sustainable management of fresh water resources is one of the great challenges of the 21st century. Since most of the planet's liquid fresh water exists as groundwater, it is essential to develop non-invasive geophysical techniques to characterize groundwater aquifers. A field experiment was conducted in the High Plains Aquifer, central United States, to explore the mechanisms governing the non-invasive Surface NMR (SNMR) technology. We acquired both SNMR data and logging NMR data at a field site, along with lithology information from drill cuttings. This allowed us to directly compare the NMR relaxation parameter measured during logging,T2, to the relaxation parameter T2* measured using the SNMR method. The latter can be affected by inhomogeneity in the magnetic field, thus obscuring the link between the NMR relaxation parameter and the hydraulic conductivity of the geologic material. When the logging T2data were transformed to pseudo-T2* data, by accounting for inhomogeneity in the magnetic field and instrument dead time, we found good agreement with T2* obtained from the SNMR measurement. These results, combined with the additional information about lithology at the site, allowed us to delineate the physical mechanisms governing the SNMR measurement. Such understanding is a critical step in developing SNMR as a reliable geophysical method for the assessment of groundwater resources.

  17. Combining Classwide Curriculum-Based Measurement and Peer Tutoring to Help General Educators Provide Adaptive Education. (United States)

    Phillips, Norris B.; And Others


    This paper describes and evaluates the efficacy of a combination of curriculum-based measurement and peer tutoring incorporated into 40 elementary education mathematics classes, to differentiate instruction and improve student achievement. The evaluation indicated that students with low achievement, average achievement, and learning disabilities…

  18. An apparatus for generation and quantitative measurement of homogeneous isotropic turbulence in He ii (United States)

    Mastracci, Brian; Guo, Wei


    The superfluid phase of helium-4, known as He ii, exhibits extremely small kinematic viscosity and may be a useful tool for economically producing and studying high Reynolds number turbulent flow. Such applications are not currently possible because a comprehensive understanding of the complex two-fluid behavior of He ii is lacking. This situation could be remedied by a systematic investigation of simple, well controlled turbulence that can be directly compared with theoretical models. To this end, we have developed a new apparatus that combines flow visualization with second sound attenuation to study turbulence in the wake of a mesh grid towed through a He ii filled channel. One of three mesh grids (mesh number M = 3, 3.75, or 5 mm) can be pulled at speeds between 0.1 and 60 cm/s through a cast acrylic flow channel which has a 16 mm × 16 mm cross section and measures 330 mm long. The motion of solidified deuterium tracer particles, with diameter of the order 1 μm, in the resulting flow is captured by a high speed camera, and a particle tracking velocimetry algorithm resolves the Lagrangian particle trajectories through the turbulent flow field. A pair of oscillating superleak second sound transducers installed in the channel allows complementary measurement of vortex line density in the superfluid throughout the turbulent decay process. Success in early experiments demonstrates the effectiveness of both probes, and preliminary analysis of the data shows that both measurements strongly correlate with each other. Further investigations will provide comprehensive information that can be used to address open questions about turbulence in He ii and move toward the application of this fluid to high Reynolds number fluid research.

  19. Evolution of Quantitative Measures in NMR: Quantum Mechanical qHNMR Advances Chemical Standardization of a Red Clover (Trifolium pratense) Extract. (United States)

    Phansalkar, Rasika S; Simmler, Charlotte; Bisson, Jonathan; Chen, Shao-Nong; Lankin, David C; McAlpine, James B; Niemitz, Matthias; Pauli, Guido F


    Chemical standardization, along with morphological and DNA analysis ensures the authenticity and advances the integrity evaluation of botanical preparations. Achievement of a more comprehensive, metabolomic standardization requires simultaneous quantitation of multiple marker compounds. Employing quantitative (1)H NMR (qHNMR), this study determined the total isoflavone content (TIfCo; 34.5-36.5% w/w) via multimarker standardization and assessed the stability of a 10-year-old isoflavone-enriched red clover extract (RCE). Eleven markers (nine isoflavones, two flavonols) were targeted simultaneously, and outcomes were compared with LC-based standardization. Two advanced quantitative measures in qHNMR were applied to derive quantities from complex and/or overlapping resonances: a quantum mechanical (QM) method (QM-qHNMR) that employs (1)H iterative full spin analysis, and a non-QM method that uses linear peak fitting algorithms (PF-qHNMR). A 10 min UHPLC-UV method provided auxiliary orthogonal quantitation. This is the first systematic evaluation of QM and non-QM deconvolution as qHNMR quantitation measures. It demonstrates that QM-qHNMR can account successfully for the complexity of (1)H NMR spectra of individual analytes and how QM-qHNMR can be built for mixtures such as botanical extracts. The contents of the main bioactive markers were in good agreement with earlier HPLC-UV results, demonstrating the chemical stability of the RCE. QM-qHNMR advances chemical standardization by its inherent QM accuracy and the use of universal calibrants, avoiding the impractical need for identical reference materials.

  20. Determining Metacarpophalangeal Flexion Angle Tolerance for Reliable Volumetric Joint Space Measurements by High-resolution Peripheral Quantitative Computed Tomography. (United States)

    Tom, Stephanie; Frayne, Mark; Manske, Sarah L; Burghardt, Andrew J; Stok, Kathryn S; Boyd, Steven K; Barnabe, Cheryl


    The position-dependence of a method to measure the joint space of metacarpophalangeal (MCP) joints using high-resolution peripheral quantitative computed tomography (HR-pQCT) was studied. Cadaveric MCP were imaged at 7 flexion angles between 0 and 30 degrees. The variability in reproducibility for mean, minimum, and maximum joint space widths and volume measurements was calculated for increasing degrees of flexion. Root mean square coefficient of variance values were spaces. Values for minimum joint space width were optimized under 10 degrees of flexion. MCP joint space measurements should be acquired at < 10 degrees of flexion in longitudinal studies.

  1. Pay-for-performance for healthcare providers: Design, performance measurement, and (unintended) effects

    NARCIS (Netherlands)

    F. Eijkenaar (Frank)


    textabstractHealthcare systems around the world are characterized by a suboptimal delivery of healthcare services. There has been a growing belief among policymakers that many deficiencies (e.g., in the quality of care) stem from flawed provider payment systems creating perverse incentives for

  2. Sourceless formation evaluation. An LWD solution providing density and neutron measurements without the use of radioisotopes

    Energy Technology Data Exchange (ETDEWEB)

    Griffiths, R.; Reichel, N. [Schlumberger, Sungai Buloh (Malaysia)


    For many years the industry has been searching for a way to eliminate the logistical difficulties and risk associated with deployment of radioisotopes for formation evaluation. The traditional gamma-gamma density (GGD) measurement uses the scattering of 662-keV gamma rays from a 137Cs radioisotopic source, with a 30.17-year half-life, to determine formation density. The traditional neutron measurement uses an Am-Be source emitting neutrons with an energy around 4 MeV, with a half-life of 432 years. Both these radioisotopic sources pose health, security, and environmental risks. Pulsed-neutron generators have been used in the industry for several decades in wireline tools and more recently in logging-while-drilling tools. These generators produce 14-MeV neutrons, many of which interact with the nuclei in the formation. Elastic collisions allow a neutron porosity measurement to be derived, which has been available to the industry since 2005. Inelastic interactions are typically followed by the emission of a variety of high-energy gamma rays. Similar to the case of the GGD measurement, the transport and attenuation of these gamma rays is a strong function of the formation density. However, the gamma-ray source is now distributed over a volume within the formation, where gamma rays have been induced by neutron interactions and the source can no longer be considered to be a point as in the case of a radioisotopic source. In addition, the extent of the induced source region depends on the transport of the fast neutrons from the source to the point of gamma-ray production. Even though the physics is more complex, it is possible to measure the formation density if the fast neutron transport is taken into account when deriving the density answer. This paper briefly reviews the physics underlying the sourceless neutron porosity and recently introduced neutron-gamma density (SNGD) measurement, demonstrates how they can be used in traditional workflows and illustrates their

  3. A calibration facility to provide traceable calibration to upper air humidity measuring sensors (United States)

    Cuccaro, Rugiada; Rosso, Lucia; Smorgon, Denis; Beltramino, Giulio; Fernicola, Vito


    Accurate knowledge and high quality measurement of the upper air humidity and of its profile in atmosphere is essential in many areas of the atmospheric research, for example in weather forecasting, environmental pollution studies and research in meteorology and climatology. Moving from the troposphere to the stratosphere, the water vapour amount varies between some percent to few part per million. For this reason, through the years, several methods and instruments have been developed for the measurement of the humidity in atmosphere. Among the instruments used for atmospheric sounding, radiosondes, airborne and balloon-borne chilled mirror hygrometer (CMH) and tunable diode laser absorption spectrometers (TDLAS) play a key role. To avoid the presence of unknown biases and systematic errors and to obtain accurate and reliable humidity measurements, these instruments need a SI-traceable calibration, preferably carried out in conditions similar to those expected in the field. To satisfy such a need, a new calibration facility has been developed at INRIM. The facility is based on a thermodynamic-based frost-point generator designed to achieve a complete saturation of the carrier gas with a single passage through an isothermal saturator. The humidity generator covers the frost point temperature range between -98 °C and -20 °C and is able to work at any controlled pressure between 200 hPa and 1000 hPa (corresponding to a barometric altitude between ground level and approximately 12000 m). The paper reports the work carried out to test the generator performances, discusses the results and presents the evaluation of the measurement uncertainty. The present work was carried out within the European Joint Research Project "MeteoMet 2 - Metrology for Essential Climate Variables" co-funded by the European Metrology Research Programme (EMRP). The EMRP is jointly funded by the EMRP participating countries within EURAMET and the European Union.

  4. A quantitative measure of restricted and repetitive behaviors for early childhood


    Wolff, Jason J.; Boyd, Brian A.; Elison, Jed T.


    Background Restricted and repetitive behaviors are characteristic phenotypic features of many neurodevelopmental, psychiatric, and neurological conditions. During early childhood, such behaviors are considered normative. More research is needed to delineate the dimensions of restricted and repetitive behavior across typical and atypical development during this period. Methods We developed the 34-item parent-rated Repetitive Behavior Scale for Early Childhood (RBS-EC) to capture quantitative, ...

  5. The importance of measuring toothpaste abrasivity in both a quantitative and qualitative way


    Johannsen, Gunnar; Tellefsen, Georg; Johannsen, Annsofi; Liljeborg, Anders


    Objective. To evaluate the relative abrasivity of different toothpastes and polishing pastes both qualitatively and quantitatively. Materials and methods. Acrylic plates were exposed to brushing in a brushing machine with a toothpaste/water slurry for 1 and 6 h. Twelve different toothpastes were used and also four different polishing pastes. The results were evaluated using a profilometer after 1 and 6 h of brushing (corresponding to 2000 and 12 000 double strokes, respectively). A surface ro...

  6. Quantitatively assessed CT imaging measures of pulmonary interstitial pneumonia: Effects of reconstruction algorithms on histogram parameters

    Energy Technology Data Exchange (ETDEWEB)

    Koyama, Hisanobu [Department of Radiology, Hyogo Kaibara Hospital, 5208-1 Kaibara, Kaibara-cho, Tanba 669-3395 (Japan)], E-mail:; Ohno, Yoshiharu [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan)], E-mail:; Yamazaki, Youichi [Department of Medical Physics and Engineering, Faculty of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita 565-0871 (Japan)], E-mail:; Nogami, Munenobu [Division of PET, Institute of Biomedical Research and Innovation, 2-2 MInamimachi, Minatojima, Chu0-ku, Kobe 650-0047 (Japan)], E-mail:; Kusaka, Akiko [Division of Radiology, Kobe University Hospital, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan)], E-mail:; Murase, Kenya [Department of Medical Physics and Engineering, Faculty of Health Sciences, Graduate School of Medicine, Osaka University, 1-7 Yamadaoka, Suita 565-0871 (Japan)], E-mail:; Sugimura, Kazuro [Department of Radiology, Kobe University Graduate School of Medicine, 7-5-2 Kusunoki-cho, Chuo-ku, Kobe 650-0017 (Japan)], E-mail:


    This study aimed the influences of reconstruction algorithm for quantitative assessments in interstitial pneumonia patients. A total of 25 collagen vascular disease patients (nine male patients and 16 female patients; mean age, 57.2 years; age range 32-77 years) underwent thin-section MDCT examinations, and MDCT data were reconstructed with three kinds of reconstruction algorithm (two high-frequencies [A and B] and one standard [C]). In reconstruction algorithm B, the effect of low- and middle-frequency space was suppressed compared with reconstruction algorithm A. As quantitative CT parameters, kurtosis, skewness, and mean lung density (MLD) were acquired from a frequency histogram of the whole lung parenchyma in each reconstruction algorithm. To determine the difference of quantitative CT parameters affected by reconstruction algorithms, these parameters were compared statistically. To determine the relationships with the disease severity, these parameters were correlated with PFTs. In the results, all the histogram parameters values had significant differences each other (p < 0.0001) and those of reconstruction algorithm C were the highest. All MLDs had fair or moderate correlation with all parameters of PFT (-0.64 < r < -0.45, p < 0.05). Though kurtosis and skewness in high-frequency reconstruction algorithm A had significant correlations with all parameters of PFT (-0.61 < r < -0.45, p < 0.05), there were significant correlations only with diffusing capacity of carbon monoxide (DLco) and total lung capacity (TLC) in reconstruction algorithm C and with forced expiratory volume in 1 s (FEV1), DLco and TLC in reconstruction algorithm B. In conclusion, reconstruction algorithm has influence to quantitative assessments on chest thin-section MDCT examination in interstitial pneumonia patients.

  7. How to Measure the Intervention Process? An Assessment of Qualitative and Quantitative Approaches to Data Collection in the Process Evaluation of Organizational Interventions. (United States)

    Abildgaard, Johan S; Saksvik, Per Ø; Nielsen, Karina


    Organizational interventions aiming at improving employee health and wellbeing have proven to be challenging to evaluate. To analyze intervention processes two methodological approaches have widely been used: quantitative (often questionnaire data), or qualitative (often interviews). Both methods are established tools, but their distinct epistemological properties enable them to illuminate different aspects of organizational interventions. In this paper, we use the quantitative and qualitative process data from an organizational intervention conducted in a national postal service, where the Intervention Process Measure questionnaire (N = 285) as well as an extensive interview study (N = 50) were used. We analyze what type of knowledge about intervention processes these two methodologies provide and discuss strengths and weaknesses as well as potentials for mixed methods evaluation methodologies.

  8. Kinetics of Poliovirus Shedding following Oral Vaccination as Measured by Quantitative Reverse Transcription-PCR versus Culture (United States)

    Begum, Sharmin; Uddin, Md Jashim; Platts-Mills, James A.; Liu, Jie; Kirkpatrick, Beth D.; Chowdhury, Anwarul H.; Jamil, Khondoker M.; Haque, Rashidul; Petri, William A.; Houpt, Eric R.


    Amid polio eradication efforts, detection of oral polio vaccine (OPV) virus in stool samples can provide information about rates of mucosal immunity and allow estimation of the poliovirus reservoir. We developed a multiplex one-step quantitative reverse transcription-PCR (qRT-PCR) assay for detection of OPV Sabin strains 1, 2, and 3 directly in stool samples with an external control to normalize samples for viral quantity and compared its performance with that of viral culture. We applied the assay to samples from infants in Dhaka, Bangladesh, after the administration of trivalent OPV (tOPV) at weeks 14 and 52 of life (on days 0 [pre-OPV], +4, +11, +18, and +25 relative to vaccination). When 1,350 stool samples were tested, the sensitivity and specificity of the quantitative PCR (qPCR) assay were 89 and 91% compared with culture. A quantitative relationship between culture+/qPCR+ and culture−/qPCR+ stool samples was observed. The kinetics of shedding revealed by qPCR and culture were similar. qPCR quantitative cutoffs based on the day +11 or +18 stool samples could be used to identify the culture-positive shedders, as well as the long-duration or high-frequency shedders. Interestingly, qPCR revealed that a small minority (7%) of infants contributed the vast majority (93 to 100%) of the total estimated viral excretion across all subtypes at each time point. This qPCR assay for OPV can simply and quantitatively detect all three Sabin strains directly in stool samples to approximate shedding both qualitatively and quantitatively. PMID:25378579

  9. Echocardiographic epicardial adipose tissue measurements provide information about cardiovascular risk in hemodialysis patients. (United States)

    Ulusal Okyay, Gülay; Okyay, Kaan; Polattaş Solak, Evşen; Sahinarslan, Asife; Paşaoğlu, Özge; Ayerden Ebinç, Fatma; Paşaoğlu, Hatice; Boztepe Derici, Ülver; Sindel, Şükrü; Arınsoy, Turgay


    Epicardial adipose tissue (EAT) is a cardiovascular risk predictor in general population. However, its value has not been well validated in maintainance hemodialysis (MHD) patients. We aimed to assess associations of EAT with cardiovascular risk predictors in nondiabetic MHD patients. In this cross-sectional study, we measured EAT thickness by transthoracic echocardiography in 50 MHD patients (45.8 ± 14.6 years of age, 37 male). Antropometric measurements, bioimpedance analysis, left ventricular (LV) mass, carotis intima media thickness, blood tests, homeostasis model assessment for insulin resistance (HOMA-IR) and hemodialysis dose by single-pool urea clearence index (spKt/V) were determined. The mean EAT thickness was 3.28 ± 1.04 mm. There were significant associations of EAT with body mass index (β = 0.590, P body fat mass (β = 0.562, P body fat mass (β = 0.408, P = 0.003), percentage of lean tissue mass (β = -0.421, P = 0.002), LV mass (β = 0.426, P = 0.002), carotis intima media thickness (β = 0.289, P = 0.042), triglyceride/high-density lipoprotein cholesterol ratio (β = 0.529, P  0.05). Body mass index, waist circumference, body fat mass, percentage of lean tissue mass, LV mass, triglyceride/high-density lipoprotein cholesterol ratio, HOMA-IR, and spKt/V appeared as independent predictors of EAT. EAT was significantly associated with body fat measures, cardiovascular risk predictors, and dialysis dose in MHD patients. © 2015 International Society for Hemodialysis.

  10. Direct Measurement of Tree Height Provides Different Results on the Assessment of LiDAR Accuracy

    Directory of Open Access Journals (Sweden)

    Emanuele Sibona


    Full Text Available In this study, airborne laser scanning-based and traditional field-based survey methods for tree heights estimation are assessed by using one hundred felled trees as a reference dataset. Comparisons between remote sensing and field-based methods were applied to four circular permanent plots located in the western Italian Alps and established within the Alpine Space project NewFor. Remote sensing (Airborne Laser Scanning, ALS, traditional field-based (indirect measurement, IND, and direct measurement of felled trees (DIR methods were compared by using summary statistics, linear regression models, and variation partitioning. Our results show that tree height estimates by Airborne Laser Scanning (ALS approximated to real heights (DIR of felled trees. Considering the species separately, Larix decidua was the species that showed the smaller mean absolute difference (0.95 m between remote sensing (ALS and direct field (DIR data, followed by Picea abies and Pinus sylvestris (1.13 m and 1.04 m, respectively. Our results cannot be generalized to ALS surveys with low pulses density (<5/m2 and with view angles far from zero (nadir. We observed that the tree heights estimation by laser scanner is closer to actual tree heights (DIR than traditional field-based survey, and this was particularly valid for tall trees with conical shape crowns.

  11. Does environmental enrichment reduce stress? An integrated measure of corticosterone from feathers provides a novel perspective.

    Directory of Open Access Journals (Sweden)

    Graham D Fairhurst

    Full Text Available Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana to assess responses to short- (10-d and long-term (3-mo enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change.

  12. Measuring the benefits of using market based approaches to provide water and sanitation in humanitarian contexts. (United States)

    Martin-Simpson, S; Parkinson, J; Katsou, E


    The use of cash transfers and market based programming (CT/MBP) to increase the efficiency and effectiveness of emergency responses is gaining prominence in the humanitarian sector. However, there is a lack of existing indicators and methodologies to monitor activities designed to strengthen water and sanitation (WaSH) markets. Gender and vulnerability markers to measure the impact of such activities on different stakeholders is also missing. This study identifies parameters to monitor, evaluate and determine the added value of utilising CT/MBP to achieve WaSH objectives in humanitarian response. The results of the work revealed that CT/MBP can be used to support household, community and market level interventions to effectively reduce transmission of faeco-oral diseases. Efficiency, effectiveness, sustainability, appropriateness and equity were identified as useful parameters which correlated to widely accepted frameworks against which to evaluate humanitarian action. The parameters were found to be directly applicable to the case of increasing demand and supply of point of use water treatment technology for a) disaster resilience activities, and b) post-crisis response. The need for peer review of the parameters and indicators and pilot measurement in humanitarian contexts was recognised. Copyright © 2017 Elsevier Ltd. All rights reserved.

  13. A spectral-domain optical coherence tomography device provides reliable corneal pachymetry measurements in canine eyes. (United States)

    Alario, A F; Pirie, C G


    The objective of this study was to determine central corneal thickness (CCT) and the intra- and interuser reliability using a portable spectral-domain optical coherence tomography (SD-OCT) device in canine eyes. Twenty clinically normal dogs were examined. CCT measurements were obtained from both eyes of each animal three times by two operators in succession. The CCT was automatically calculated using the pachymetry software generated from eight radial scans, 6 mm in length. Mean canine CCT was 606.83±39.45 μm for all eyes examined. There was no significant difference in CCT based on the eye examined (OD vs OS), age or gender of the animal. There was no significant difference in CCT between replicates performed by the same operator; however, a small but significant difference was noted in CCT between operators. The mean difference in CCT between operators was 1.9 μm (P=0.03). The coefficient of variation for each user and between users was very low (range 0.64-1.7 per cent). The intraclass correlation coefficient comparing operators was 0.975. Based on these results, the SD-OCT device evaluated is capable of obtaining precise CCT measurements with excellent intra- and interoperator reliability in canine eyes.

  14. A new sentence generator providing material for maximum reading speed measurement. (United States)

    Perrin, Jean-Luc; Paillé, Damien; Baccino, Thierry


    A new method is proposed to generate text material for assessing maximum reading speed of adult readers. The described procedure allows one to generate a vast number of equivalent short sentences. These sentences can be displayed for different durations in order to determine the reader's maximum speed using a psychophysical threshold algorithm. Each sentence is built so that it is either true or false according to common knowledge. The actual reading is verified by asking the reader to determine the truth value of each sentence. We based our design on the generator described by Crossland et al. and upgraded it. The new generator handles concepts distributed in an ontology, which allows an easy determination of the sentences' truth value and control of lexical and psycholinguistic parameters. In this way many equivalent sentence can be generated and displayed to perform the measurement. Maximum reading speed scores obtained with pseudo-randomly chosen sentences from the generator were strongly correlated with maximum reading speed scores obtained with traditional MNREAD sentences (r = .836). Furthermore, the large number of sentences that can be generated makes it possible to perform repeated measurements, since the possibility of a reader learning individual sentences is eliminated. Researchers interested in within-reader performance variability could use the proposed method for this purpose.

  15. Does Environmental Enrichment Reduce Stress? An Integrated Measure of Corticosterone from Feathers Provides a Novel Perspective (United States)

    Fairhurst, Graham D.; Frey, Matthew D.; Reichert, James F.; Szelest, Izabela; Kelly, Debbie M.; Bortolotti, Gary R.


    Enrichment is widely used as tool for managing fearfulness, undesirable behaviors, and stress in captive animals, and for studying exploration and personality. Inconsistencies in previous studies of physiological and behavioral responses to enrichment led us to hypothesize that enrichment and its removal are stressful environmental changes to which the hormone corticosterone and fearfulness, activity, and exploration behaviors ought to be sensitive. We conducted two experiments with a captive population of wild-caught Clark's nutcrackers (Nucifraga columbiana) to assess responses to short- (10-d) and long-term (3-mo) enrichment, their removal, and the influence of novelty, within the same animal. Variation in an integrated measure of corticosterone from feathers, combined with video recordings of behaviors, suggests that how individuals perceive enrichment and its removal depends on the duration of exposure. Short- and long-term enrichment elicited different physiological responses, with the former acting as a stressor and birds exhibiting acclimation to the latter. Non-novel enrichment evoked the strongest corticosterone responses of all the treatments, suggesting that the second exposure to the same objects acted as a physiological cue, and that acclimation was overridden by negative past experience. Birds showed weak behavioral responses that were not related to corticosterone. By demonstrating that an integrated measure of glucocorticoid physiology varies significantly with changes to enrichment in the absence of agonistic interactions, our study sheds light on potential mechanisms driving physiological and behavioral responses to environmental change. PMID:21412426

  16. Quantitative shearography: error reduction by using more than three measurement channels


    Charrett, Thomas O. H.; Francis, Daniel; Tatam, Ralph P.


    Shearography is a noncontact optical technique used to measure surface displacement derivatives. Full surface strain characterization can be achieved using shearography configurations employing at least three measurement channels. Each measurement channel is sensitive to a single displacement gradient component defined by its sensitivity vector. A matrix transformation is then required to convert the measured components to the orthogonal displacement gradients required for q...

  17. Comparison of Quantitative Cartilage T2 Measurements and Qualitative MR Imaging between Professional Ballet Dancers and Healthy Volunteers. (United States)

    Cha, Jang Gyu; Yi, Ji Sook; Han, Jong Kyu; Lee, Young Koo


    To compare qualitative magnetic resonance (MR) images and quantitative T2 measurements of the tibiotalar cartilage between ballerinas and healthy volunteers. Institutional review board approval for this study and informed consent (from all participants) were obtained. MR examinations were performed by using a 3-T MR imaging system with 21 professional female ballet dancers and 20 healthy female volunteers. Two musculoskeletal radiologists qualitatively measured tibiotalar cartilage T2 values in the anterior zones, middle zones, and posterior zones of cartilage. MR findings were also qualitatively analyzed in both groups. The tibial cartilage T2 values measured in the anterior and posterior zones and the talar cartilage T2 values measured in all three zones were significantly higher in the ballerina group than in the control group (P measurement may potentially be used as a noninvasive imaging tool for early detection of cartilage lesions in the tibiotalar joint.

  18. Enhanced tumor contrast during breast lumpectomy provided by independent component analysis of localized reflectance measures (United States)

    Eguizabal, Alma; Laughney, Ashley M.; Garcia Allende, Pilar Beatriz; Krishnaswamy, Venkataramanan; Wells, Wendy A.; Paulsen, Keith D.; Pogue, Brian W.; Lopez-Higuera, Jose M.; Conde, Olga M.


    A spectral analysis technique to enhance tumor contrast during breast conserving surgery is proposed. A set of 29 surgically-excised breast tissues have been imaged in local reflectance geometry. Measures of broadband reflectance are directly analyzed using Principle Component Analysis (PCA), on a per sample basis, to extract areas of maximal spectral variation. A dynamic selection threshold has been applied to obtain the final number of principal components, accounting for inter-patient variability. A blind separation technique based on Independent Component Analysis (ICA) is then applied to extract diagnostically powerful results. ICA application reveals that the behavior of one independent component highly correlates with the pathologic diagnosis and it surpasses the contrast obtained using empirical models. Moreover, blind detection characteristics (no training, no comparisons with training reference data) and no need for parameterization makes the automated diagnosis simple and time efficient, favoring its translation to the clinical practice. Correlation coefficient with model-based results up to 0.91 has been achieved.

  19. Quantitative measurement of histamine H{sub 1} receptors in human brains by PET and [{sup 11}C]doxepin

    Energy Technology Data Exchange (ETDEWEB)

    Mochizuki, Hideki; Kimura, Yuichi E-mail:; Ishii, Kenji; Oda, Keiichi; Sasaki, Toru; Tashiro, Manabu; Yanai, Kazuhiko; Ishiwata, Kiichi


    The aim of this study is to establish a method for quantitative measurement of histamine H{sub 1} receptor (H1R) in human brain by PET and [{sup 11}C]doxepin ([{sup 11}C]DOX). The estimated parameters with a two-compartment model were stable for the initial values for parameter estimation but those with a three-compartment model were not. This finding suggests that the H1R measured by the [{sup 11}C]DOX and PET can be evaluated with a two-compartment model.

  20. Contralateral delay activity provides a neural measure of the number of representations in visual working memory. (United States)

    Ikkai, Akiko; McCollough, Andrew W; Vogel, Edward K


    Visual working memory (VWM) helps to temporarily represent information from the visual environment and is severely limited in capacity. Recent work has linked various forms of neural activity to the ongoing representations in VWM. One piece of evidence comes from human event-related potential studies, which find a sustained contralateral negativity during the retention period of VWM tasks. This contralateral delay activity (CDA) has previously been shown to increase in amplitude as the number of memory items increases, up to the individual's working memory capacity limit. However, significant alternative hypotheses remain regarding the true nature of this activity. Here we test whether the CDA is modulated by the perceptual requirements of the memory items as well as whether it is determined by the number of locations that are being attended within the display. Our results provide evidence against these two alternative accounts and instead strongly support the interpretation that this activity reflects the current number of objects that are being represented in VWM.

  1. Planarians as models of cadmium-induced neoplasia provide measurable benchmarks for mechanistic studies. (United States)

    Voura, Evelyn B; Montalvo, Melissa J; Dela Roca, Kevin T; Fisher, Julia M; Defamie, Virginie; Narala, Swami R; Khokha, Rama; Mulligan, Margaret E; Evans, Colleen A


    Bioassays of planarian neoplasia highlight the potential of these organisms as useful standards to assess whether environmental toxins such as cadmium promote tumorigenesis. These studies complement other investigations into the exceptional healing and regeneration of planarians - processes that are driven by a population of active stem cells, or neoblasts, which are likely transformed during planarian tumor growth. Our goal was to determine if planarian tumorigenesis assays are amenable to mechanistic studies of cadmium carcinogenesis. To that end we demonstrate, by examining both counts of cell populations by size, and instances of mitosis, that the activity of the stem cell population can be monitored. We also provide evidence that specific biomodulators can affect the potential of planarian neoplastic growth, in that an inhibitor of metalloproteinases effectively blocked the development of the lesions. From these results, we infer that neoblast activity does respond to cadmium-induced tumor growth, and that metalloproteinases are required for the progression of cancer in the planarian. Copyright © 2017 Elsevier Inc. All rights reserved.

  2. A Simplified Quantitative Method to Measure Brain Shifts in Patients with Middle Cerebral Artery Stroke. (United States)

    Paletta, Nina; Maali, Laith; Zahran, Abdurrehman; Sethuraman, Sankara; Figueroa, Ramon; Nichols, Fenwick T; Bruno, Askiel


    A standardized and validated method to measure brain shifts in malignant middle cerebral artery (MCA) stroke with decompressive hemicraniectomy (DHC) could facilitate clinical decision making, prognostication, and comparison of results between studies. We tested for reliability simplified methods to measure transcalvarial herniation, midline brain shift, and the contralateral cerebral ventricular atrium in malignant MCA stroke after DHC. Multiple raters measured brain shifts on post-DHC computed tomography (CT) scans with aligned and unaligned slice orientations in 25 patients. We compared the simplified measurements to previously reported more meticulous measurements. The simplified measurements correlate well with the more meticulous measurements on both aligned and unaligned CTs (intraclass correlation coefficients .72-.89). These simplified and expedient methods of measuring brain shifts in malignant MCA stroke after DHC correlate well with the more meticulous methods. Copyright © 2017 by the American Society of Neuroimaging.

  3. A quantitative measure of restricted and repetitive behaviors for early childhood. (United States)

    Wolff, Jason J; Boyd, Brian A; Elison, Jed T


    Restricted and repetitive behaviors are characteristic phenotypic features of many neurodevelopmental, psychiatric, and neurological conditions. During early childhood, such behaviors are considered normative. More research is needed to delineate the dimensions of restricted and repetitive behavior across typical and atypical development during this period. We developed the 34-item parent-rated Repetitive Behavior Scale for Early Childhood (RBS-EC) to capture quantitative, dimensional features across a broad range of behaviors contributing to this domain. We evaluated its psychometric properties and factor structure in a community sample of 914 toddlers. The RBS-EC showed excellent overall internal consistency (α = 0.90), strong test-retest reliability (ICC = 0.87 for topographies and 0.90 for frequency) and evidence of convergent and discriminative validity. Using a split-half approach to factor analysis, we identified that a three- or four-factor structure best fit the data and confirmatory factor analysis indicated acceptable fit for both models. The empirically derived four-factor model was consistent with our conceptual model and included repetitive motor, restricted interests and behavior, ritual and routine, and self-directed behavior. This initial study indicates that the RBS-EC is a reliable and valid instrument for characterizing quantitative, dimensional aspects of restricted and repetitive behaviors in young children.


    Directory of Open Access Journals (Sweden)

    А. М. Hashimov


    Full Text Available The article presents design engineering methods for the high-voltage pulse installations of technological purpose for disinfection of drinking water, sewage, and edible liquids by high field micro- and nanosecond pulsing exposure. Designing potentialities are considered of the principal elements of the high-voltage part and the discharge circuit of the installations towards assuring the best efficient on-load utilization of the source energy and safe operation of the high-voltage equipment. The study shows that for disinfection of drinking water and sewage it is expedient to apply microsecond pulse actions causing the electrohydraulic effect in aqueous media with associated complex of physical processes (ultraviolet emission, generation of ozone and atomic oxygen, mechanical compression waves, etc. having detrimental effect on life activity of the microorganisms. In case of disinfecting edible liquids it is recommended to use the nanosecond pulses capable of straight permeating the biological cell nucleus, inactivating it. Meanwhile, the nutritive and biological values of the foodstuffs are saved and their organoleptic properties are improved. It is noted that in elaboration process of high-frequency pulse installations special consideration should be given to issues of the operating personnel safety discipline and securing conditions for the entire installation uninterrupted performance. With this objective in view the necessary requirements should be fulfilled on shielding the high- and low-voltage installation parts against high-frequency electromagnetic emissions registered by special differential sensors. Simultaneously, the abatement measures should be applied on the high-voltage equipment operational noise level. The authors offer a technique for noise abatement to admissible levels (lower than 80 dB A by means of coating the inside surface with shielded enclosure of densely-packed abutting sheets of porous electro-acoustic insulating

  5. Quantitative photoacoustic integrating sphere (QPAIS) platform for absorption coefficient and Grüneisen parameter measurements: Demonstration with human blood. (United States)

    Villanueva-Palero, Yolanda; Hondebrink, Erwin; Petersen, Wilma; Steenbergen, Wiendelt


    Quantitative photoacoustic imaging in biomedicine relies on accurate measurements of relevant material properties of target absorbers. Here, we present a method for simultaneous measurements of the absorption coefficient and Grüneisen parameter of small volume of liquid scattering and absorbing media using a coupled-integrating sphere system which we refer to as quantitative photoacoustic integrating sphere (QPAIS) platform. The derived equations do not require absolute magnitudes of optical energy and pressure values, only calibration of the setup using aqueous ink dilutions is necessary. As a demonstration, measurements with blood samples from various human donors are done at room and body temperatures using an incubator. Measured absorption coefficient values are consistent with known oxygen saturation dependence of blood absorption at 750 nm, whereas measured Grüneisen parameter values indicate variability among five different donors. An increasing Grüneisen parameter value with both hematocrit and temperature is observed. These observations are consistent with those reported in literature.

  6. Genome-wide association studies of quantitatively measured skin, hair, and eye pigmentation in four European populations.

    Directory of Open Access Journals (Sweden)

    Sophie I Candille

    Full Text Available Pigmentation of the skin, hair, and eyes varies both within and between human populations. Identifying the genes and alleles underlying this variation has been the goal of many candidate gene and several genome-wide association studies (GWAS. Most GWAS for pigmentary traits to date have been based on subjective phenotypes using categorical scales. But skin, hair, and eye pigmentation vary continuously. Here, we seek to characterize quantitative variation in these traits objectively and accurately and to determine their genetic basis. Objective and quantitative measures of skin, hair, and eye color were made using reflectance or digital spectroscopy in Europeans from Ireland, Poland, Italy, and Portugal. A GWAS was conducted for the three quantitative pigmentation phenotypes in 176 women across 313,763 SNP loci, and replication of the most significant associations was attempted in a sample of 294 European men and women from the same countries. We find that the pigmentation phenotypes are highly stratified along axes of European genetic differentiation. The country of sampling explains approximately 35% of the variation in skin pigmentation, 31% of the variation in hair pigmentation, and 40% of the variation in eye pigmentation. All three quantitative phenotypes are correlated with each other. In our two-stage association study, we reproduce the association of rs1667394 at the OCA2/HERC2 locus with eye color but we do not identify new genetic determinants of skin and hair pigmentation supporting the lack of major genes affecting skin and hair color variation within Europe and suggesting that not only careful phenotyping but also larger cohorts are required to understand the genetic architecture of these complex quantitative traits. Interestingly, we also see that in each of these four populations, men are more lightly pigmented in the unexposed skin of the inner arm than women, a fact that is underappreciated and may vary across the world.

  7. Genome-Wide Association Studies of Quantitatively Measured Skin, Hair, and Eye Pigmentation in Four European Populations (United States)

    Candille, Sophie I.; Absher, Devin M.; Beleza, Sandra; Bauchet, Marc; McEvoy, Brian; Garrison, Nanibaa’ A.; Li, Jun Z.; Myers, Richard M.; Barsh, Gregory S.; Tang, Hua; Shriver, Mark D.


    Pigmentation of the skin, hair, and eyes varies both within and between human populations. Identifying the genes and alleles underlying this variation has been the goal of many candidate gene and several genome-wide association studies (GWAS). Most GWAS for pigmentary traits to date have been based on subjective phenotypes using categorical scales. But skin, hair, and eye pigmentation vary continuously. Here, we seek to characterize quantitative variation in these traits objectively and accurately and to determine their genetic basis. Objective and quantitative measures of skin, hair, and eye color were made using reflectance or digital spectroscopy in Europeans from Ireland, Poland, Italy, and Portugal. A GWAS was conducted for the three quantitative pigmentation phenotypes in 176 women across 313,763 SNP loci, and replication of the most significant associations was attempted in a sample of 294 European men and women from the same countries. We find that the pigmentation phenotypes are highly stratified along axes of European genetic differentiation. The country of sampling explains approximately 35% of the variation in skin pigmentation, 31% of the variation in hair pigmentation, and 40% of the variation in eye pigmentation. All three quantitative phenotypes are correlated with each other. In our two-stage association study, we reproduce the association of rs1667394 at the OCA2/HERC2 locus with eye color but we do not identify new genetic determinants of skin and hair pigmentation supporting the lack of major genes affecting skin and hair color variation within Europe and suggesting that not only careful phenotyping but also larger cohorts are required to understand the genetic architecture of these complex quantitative traits. Interestingly, we also see that in each of these four populations, men are more lightly pigmented in the unexposed skin of the inner arm than women, a fact that is underappreciated and may vary across the world. PMID:23118974

  8. Association between quantitative measures obtained using fluorescence-based methods and activity status of occlusal caries lesions in primary molars. (United States)

    Novaes, Tatiane Fernandes; Reyes, Alessandra; Matos, Ronilza; Antunes-Pontes, Laura Regina; Marques, Renata Pereira de Samuel; Braga, Mariana Minatel; Diniz, Michele Baffi; Mendes, Fausto Medeiros


    Fluorescence-based methods (FBM) can add objectiveness to diagnosis strategy for caries. Few studies, however, have focused on the evaluation of caries activity. To evaluate the association between quantitative measures obtained with FBM, clinical parameters acquired from the patients, caries detection, and assessment of activity status in occlusal surfaces of primary molars. Six hundred and six teeth from 113 children (4-14 years) were evaluated. The presence of a biofilm, caries experience, and the number of active lesions were recorded. The teeth were assessed using FBM: DIAGNOdent pen (Lfpen) and Quantitative light-induced fluorescence (QLF). As reference standard, all teeth were evaluated using the ICDAS (International Caries Detection and Assessment System) associated with clinical activity assessments. Multilevel regressions compared the FBM values and evaluated the association between the FBM measures and clinical variables related to the caries activity. The measures from the FBM were higher in cavitated lesions. Only, ∆F values distinguished active and inactive lesions. The LFpen measures were higher in active lesions, at the cavitated threshold (56.95 ± 29.60). Following regression analyses, only the presence of visible biofilm on occlusal surfaces (adjusted prevalence ratio = 1.43) and ∆R values of the teeth (adjusted prevalence ratio = 1.02) were associated with caries activity. Some quantitative measures from FBM parameters are associated with caries activity evaluation, which is similar to the clinical evaluation of the presence of visible biofilm. © 2016 BSPD, IAPD and John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  9. A high throughput Nile red method for quantitative measurement of neutral lipids in microalgae. (United States)

    Chen, Wei; Zhang, Chengwu; Song, Lirong; Sommerfeld, Milton; Hu, Qiang


    Isolation of high neutral lipid-containing microalgae is key to the commercial success of microalgae-based biofuel production. The Nile red fluorescence method has been successfully applied to the determination of lipids in certain microalgae, but has been unsuccessful in many others, particularly those with thick, rigid cell walls that prevent the penetration of the fluorescence dye. The conventional "one sample at a time" method was also time-consuming. In this study, the solvent dimethyl sulfoxide (DMSO) was introduced to microalgal samples as the stain carrier at an elevated temperature. The cellular neutral lipids were determined and quantified using a 96-well plate on a fluorescence spectrophotometer with an excitation wavelength of 530 nm and an emission wavelength of 575 nm. An optimized procedure yielded a high correlation coefficient (R(2)=0.998) with the lipid standard triolein and repeated measurements of replicates. Application of the improved method to several green algal strains gave very reproducible results with relative standard errors of 8.5%, 3.9% and 8.6%, 4.5% for repeatability and reproducibility at two concentration levels (2.0 microg/mL and 20 microg/mL), respectively. Moreover, the detection and quantification limits of the improved Nile red staining method were 0.8 microg/mL and 2.0 microg/mL for the neutral lipid standard triolein, respectively. The modified method and a conventional gravimetric determination method provided similar results on replicate samples. The 96-well plate-based Nile red method can be used as a high throughput technique for rapid screening of a broader spectrum of naturally-occurring and genetically-modified algal strains and mutants for high neutral lipid/oil production.

  10. Targeted, LCMS-based Metabolomics for Quantitative Measurement of NAD(+) Metabolites. (United States)

    Trammell, Samuel Aj; Brenner, Charles


    Nicotinamide adenine dinucleotide (NAD(+)) is a coenzyme for hydride transfer reactions and a substrate for sirtuins and other NAD(+)-consuming enzymes. The abundance of NAD (+), NAD(+) biosynthetic intermediates, and related nucleotides reflects the metabolic state of cells and tissues. High performance liquid chromatography (HPLC) followed by ultraviolet-visible (UV-Vis) spectroscopic analysis of NAD(+) metabolites does not offer the specificity and sensitivity necessary for robust quantification of complex samples. Thus, we developed a targeted, quantitative assay of the NAD(+) metabolome with the use of HPLC coupled to mass spectrometry. Here we discuss NAD(+) metabolism as well as the technical challenges required for reliable quantification of the NAD(+) metabolites. The new method incorporates new separations and improves upon a previously published method that suffered from the problem of ionization suppression for particular compounds.

  11. Conventional Direction to Unconventional Measures: Using Quantitative Easing to shape Eurozone Fiscal Capacity

    Directory of Open Access Journals (Sweden)

    Fontana Olimpia


    Full Text Available Eight years after the outbreak of the crisis, the Eurozone (EZ fiscal policy remains fragmented at the national level. This paper fills the structural gap between the monetary and fiscal dimensions of EZ economic policy by suggesting a ‘conventional’ direction to the unconventional Quantitative Easing (QE policy of the European Central Bank (ECB. We propose an evolution for QE to tackle the shortcomings of the current ‘decentralized’ fiscal policy in the EZ. In a nutshell, we suggest a change in the composition of QE asset purchases, focusing on buying European Investment Bank (EIB bonds that, in turn, would be used to finance real investments through the Juncker Plan programme. The rationale of our proposal is legitimised by an overview of the gloomy macroeconomic conditions of the EZ, and the situation in ongoing policies. The mechanism is described in detail, with a discussion of both its strengths and possible limitations.

  12. Quantitative detection of the respective concentrations of chiral compounds with weak measurements (United States)

    Xie, Linguo; Qiu, Xiaodong; Luo, Lan; Liu, Xiong; Li, Zhaoxue; Zhang, Zhiyou; Du, Jinglei; Wang, Deqiang


    In this letter, we determine the respective concentrations of glucose and fructose in the mixed chiral solution by simultaneously measuring the optical rotation angle (ORA) and the refractive index change (RIC) with weak measurements. The photonic spin Hall effect (PSHE) serves as a probe in our scheme. The measurement of ORA is based on the high sensitivity of the amplification factor to the polarization state in weak measurements. The measurement of RIC is based on the rapid variation of spin splitting of the PSHE. The measurement precision of the respective concentrations can be achieved to be 0.02 mg/ml. This method can detect traces of enantiomeric impurities and has a potential application in chiral sensing.

  13. Quantitative methanol-burning lung model for validating gas-exchange measurements over wide ranges of FIO2. (United States)

    Miodownik, S; Melendez, J; Carlon, V A; Burda, B


    The methanol-burning lung model has been used as a technique for generating a predictable ratio of carbon dioxide production (VCO2) to oxygen consumption (VO2) or respiratory quotient (RQ). Although an accurate RQ can be generated, quantitatively predictable and adjustable VO2 and VCO2 cannot be generated. We describe a new burner device in which the combustion rate of methanol is always equal to the infusion rate of fuel over an extended range of O2 concentrations. This permits the assembly of a methanol-burning lung model that is usable with O2 concentrations up to 100% and provides continuously adjustable and quantitative VO2 (69-1,525 ml/min) and VCO2 (46-1,016 ml/min) at a RQ of 0.667.

  14. Quantitative, Non-Experimental Approaches to the Microeconomic Evaluation of Public Policy Measures : a Survey


    Keilbach, Max


    The objective of evaluating public policy measures is to assess its implications and thus to obtain a measure for weather the respective program has been successful. In this paper, we consider and classify microeconomic and microeconometric approaches to measuring this success. To do so, the evaluation problem is outlined and three estimation priciples are presented. For each of these, underlying assumptions are identified and the consequences of their violation discussed.

  15. Quantitative comparison of in situ soil CO2 flux measurement methods (United States)

    Jennifer D. Knoepp; James M. Vose


    Development of reliable regional or global carbon budgets requires accurate measurement of soil CO2 flux. We conducted laboratory and field studies to determine the accuracy and comparability of methods commonly used to measure in situ soil CO2 fluxes. Methods compared included CO2...

  16. Perfusion measurements of the brain: using dynamic CT for the quantitative assessment of cerebral ischemia in acute stroke

    Energy Technology Data Exchange (ETDEWEB)

    Klotz, Ernst E-mail:; Koenig, Matthias


    Objective: Perfusion CT has been successfully used as a functional imaging technique for the differential diagnosis of patients with hyperacute stroke. We investigated to what extent this technique can also be used for the quantitative assessment of cerebral ischemia. Methods and material: We studied linearity, spatial resolution and noise behaviour of cerebral blood flow (CBF) determination with computer simulations and phantom measurements. Statistical ROI based analysis of CBF images of a subset of 38 patients from a controlled clinical stroke study with currently more than 75 patients was done to check the power of relative cerebral blood flow (rCBF) values to predict definite infarction and ischemic penumbra. Classification was performed using follow-up CT and MR data. Results: Absolute CBF values were systematically underestimated, the degree depended on the cardiac output of the patients. Phantom measurements and simulations indicated very good linearity allowing reliable calculation of rCBF values. Infarct and penumbra areas in 19 patients receiving standard heparin therapy had mean rCBF values of 0.19 and 0.62, respectively. The corresponding values for 19 patients receiving local intraarterial fibrinolysis were 0.18 and 0.57. The difference between infarct and penumbra values was highly significant (P<0.0001) in both groups. No penumbra area was found with an rCBF value of less than 0.20. While in the heparin group only 25% of all areas with an rCBF between 0.20 and 0.35 survived, in the fibrinolytic group 61% of these areas could be saved (P<0.05). Conclusion: Perfusion CT is a fast and practical technique for routine clinical application. It provides substantial and important additional information for the selection of the optimal treatment strategy for patients with hyperacute stroke. Relative values of cerebral blood flow discriminate very well between areas of reversible and irreversible ischemia; an rCBF value of 0.20 appears to be a definite lower

  17. Repeated quantitative measurements of De Novo synthesis of albumin and fibrinogen.

    Directory of Open Access Journals (Sweden)

    Gabriel Dumitrescu

    Full Text Available The possibility of using two different isotopomers, for the incorporation of isotopically labeled amino acids, was explored to enable longitudinal studies of de novo synthesis of two export liver proteins, albumin and fibrinogen. The agreement of the synthesis rates between the two different labels was evaluated along with the reproducibility of repeated experiments using different time intervals. Healthy volunteers were studied in a standardized fed state. Protocol A (n = 10 involved two measurements 48 hours apart. Protocol B (n = 6 involved three measurements at baseline and five hours and then seven days after the initial measurement. De novo synthesis of albumin and fibrinogen by the incorporation of D5-phenylalanine or D8-phenylalanine were measured using the flooding dose technique. Albumin and fibrinogen were isolated from plasma using standard techniques. Fractional and absolute synthesis rates were calculated. Repeated measurements employing the two isotoptomers showed good agreement for albumin fractional synthesis rate after 48 hours (p = 0.92 and after 7 days (p = 0.99, with a coefficient of variation of 5.9% when using the same isotopic label. For fibrinogen, the coefficient of variation for the fractional synthesis rate employing the same isotopic label was 16.6%. Repeated measurements after 48 hours and seven days showed less agreement although there was no statistical difference (P = 0.32 and P = 0.30 respectively. Repeated measurement after five hours showed a statistical significant difference for the fractional synthesis rate of fibrinogen (p = 0.008 but not for albumin (p = 0.12. Repeated measurements of albumin de novo synthesis more than 48 hours apart show acceptable agreement using either one or two different isotopic labels. For fibrinogen the larger intra-individual scatter necessitates larger study groups to detect changes in longitudinal studies. Repeated measurements within 48 hours need to be validated further.

  18. Quantitative myocardial perfusion measurement using CT perfusion: a validation study in a porcine model of reperfused acute myocardial infarction. (United States)

    So, Aaron; Hsieh, Jiang; Li, Jian-Ying; Hadway, Jennifer; Kong, Hua-Fu; Lee, Ting-Yim


    We validated a CT perfusion technique with beam hardening (BH) correction for quantitative measurement of myocardial blood flow (MBF). Acute myocardial infarction (AMI) was created in four pigs by occluding the distal LAD for 1 h followed by reperfusion. MBF was measured from dynamic contrast enhanced CT (DCE-CT) scanning of the heart, with correction of cardiac motion and BH, before ischemic insult and on day 7, 10 and 14 post. On day 14 post, radiolabeled microspheres were injected to measure MBF and the results were compared with those measured by CT perfusion. Excised hearts were stained with 2,3,5-triphenyltetrazolium chloride (TTC) to determine the relationship between MBF measured by CT Perfusion and myocardial viability. MBF measured by CT perfusion was strongly correlated with that by microspheres over a wide range of MBF values (R = 0.81, from 25 to 225 ml min(-1) 100 g(-1)). While MBF in the LAD territory decreased significantly from 98.4 ± 2.5 ml min(-1) 100 g(-1) at baseline to 32.2 ± 9.1 ml min(-1) 100 g(-1), P 0.05). TTC staining confirmed incomplete infarction in the LAD territory and no infarction in the LCx territory. Microvascular obstruction in infarcted tissue resulted in no-reflow and hence persistently low MBF in the reperfused LAD territory which contained a mixture of viable and non-viable tissue. CT perfusion measurement of MBF was accurate and correlated well with histology and microspheres measurements.

  19. Quantitative evaluation of corneal epithelial injury caused by n-heptanol using a corneal resistance measuring device in vivo

    Directory of Open Access Journals (Sweden)

    Fukuda M


    Full Text Available Masamichi Fukuda1, Hiroshi Sasaki11Department of Ophthalmology, Kanazawa Medical University, Uchinada, JapanPurpose: We attempted to develop a device for measuring electrical corneal resistance (CR using corneal contact lens electrodes to quantitatively evaluate corneal injury in vivo. In the present study, full-thickness detachment of the corneal epithelium was induced by n-heptanol, and the feasibility of the quantitative evaluation of this injury by corneal contact lens electrodes was evaluated in vivo.Methods: The central area of an albino rabbit's cornea was exposed to a filter paper pre-immersed in n-heptanol for 1 minute to induce injury of the corneal epithelium. After induction of injury, the electrical CR was measured and the percentage of CR (%CR was calculated. Fluorescein solution (3 µL was applied to the wound/affected area of the corneal epithelium for photography with a slit-lamp biomicroscope. The wound/affected area was measured using an image analysis system. The correlation between the %CR and the wound/affected area was analyzed.Results: As the size of the wound/affected area of the corneal epithelium increased, the %CR decreased after corneal epithelium detachment. Thus, a close correlation was found between the area of corneal epithelium detachment and the %CR.Conclusion: The corneal resistance device that we developed was capable of quantitatively evaluating n-heptanol-induced full-thickness injuries of the corneal epithelium.Keywords: eyes in vivo, corneal injury, corneal contact lens electrode corneal resistance device, n-heptanol

  20. Measuring quantitative autism traits in families: informant effect or intergenerational transmission? (United States)

    De la Marche, Wouter; Noens, Ilse; Kuppens, Sofie; Spilt, Jantine L; Boets, Bart; Steyaert, Jean


    Autism spectrum disorders (ASD) have a high degree of heritability, but there is still much debate about specific causal genes and pathways. To gain insight into patterns of transmission, research has focused on the relatedness of quantitative autism traits (QAT) between family members, mostly using questionnaires. Yet, different kinds of bias may influence research results. In this paper, we focus on possible informant effects and, taking these into account, on possible intergenerational transmission of QAT. This study used multiple informant data retrieved via the Social Responsiveness Scale from 170 families with at least one member with ASD. Using intraclass correlations (ICCs) and mixed model analyses, we investigated inter-informant agreement and differences between parent and teacher reports on children and between self- and other-reports on adults. Using structural equation modelling (SEM), we investigated the relatedness of QAT between family members in ASD families. Parent-teacher agreement about social responsiveness was poor, especially for children with ASD, though agreement between parents was moderate to strong for affected and unaffected children. Agreement between self- and other-report in adult men was good, but only moderate in women. Agreement did not differ between adults with and without ASD. While accounting for informant effects, our SEM results corroborated the assortative mating theory and the intergenerational transmission of QAT from both fathers and mothers to their offspring.

  1. Visually observed mold and moldy odor versus quantitatively measured microbial exposure in homes (United States)

    Reponen, Tiina; Singh, Umesh; Schaffer, Chris; Vesper, Stephen; Johansson, Elisabet; Adhikari, Atin; Grinshpun, Sergey A.; Indugula, Reshmi; Ryan, Patrick; Levin, Linda; LeMasters, Grace


    The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children’s asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child’s age 1 (Year 1). Similar assessment supplemented with air sampling was conducted in Year 7. Samples were analyzed for endotoxin, (1–3)-β-D-glucan, and fungal spores. The Mold Specific Quantitative Polymerase Chain Reaction assay was used to analyze 36 mold species in dust samples, and the Environmental Relative Moldiness Index (ERMI) was calculated. Homes were categorized based on three criteria: 1) visible mold damage, 2) moldy odor, and 3) ERMI. Even for homes where families had not moved, Year 7 endotoxin and (1–3)-β-D-glucan exposures were significantly higher than those in Year 1 (pmold damage categories, but were consistently higher in homes with moldy odor and in homes that had high ERMI. Low correlations between results in air and dust samples indicate different types or durations of potential microbial exposures from dust vs. air. Future analysis will indicate which, if any, of the assessment methods is associated with the development of asthma. PMID:20810150

  2. Bayesian analysis of high-throughput quantitative measurement of protein-DNA interactions.

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    David D Pollock

    Full Text Available Transcriptional regulation depends upon the binding of transcription factor (TF proteins to DNA in a sequence-dependent manner. Although many experimental methods address the interaction between DNA and proteins, they generally do not comprehensively and accurately assess the full binding repertoire (the complete set of sequences that might be bound with at least moderate strength. Here, we develop and evaluate through simulation an experimental approach that allows simultaneous high-throughput quantitative analysis of TF binding affinity to thousands of potential DNA ligands. Tens of thousands of putative binding targets can be mixed with a TF, and both the pre-bound and bound target pools sequenced. A hierarchical Bayesian Markov chain Monte Carlo approach determines posterior estimates for the dissociation constants, sequence-specific binding energies, and free TF concentrations. A unique feature of our approach is that dissociation constants are jointly estimated from their inferred degree of binding and from a model of binding energetics, depending on how many sequence reads are available and the explanatory power of the energy model. Careful experimental design is necessary to obtain accurate results over a wide range of dissociation constants. This approach, which we call Simultaneous Ultra high-throughput Ligand Dissociation EXperiment (SULDEX, is theoretically capable of rapid and accurate elucidation of an entire TF-binding repertoire.

  3. Visually observed mold and moldy odor versus quantitatively measured microbial exposure in homes. (United States)

    Reponen, Tiina; Singh, Umesh; Schaffer, Chris; Vesper, Stephen; Johansson, Elisabet; Adhikari, Atin; Grinshpun, Sergey A; Indugula, Reshmi; Ryan, Patrick; Levin, Linda; Lemasters, Grace


    The main study objective was to compare different methods for assessing mold exposure in conjunction with an epidemiologic study on the development of children's asthma. Homes of 184 children were assessed for mold by visual observations and dust sampling at child's age 1 (Year 1). Similar assessment supplemented with air sampling was conducted in Year 7. Samples were analyzed for endotoxin, (1-3)-β-D-glucan, and fungal spores. The Mold Specific Quantitative Polymerase Chain Reaction assay was used to analyze 36 mold species in dust samples, and the Environmental Relative Moldiness Index (ERMI) was calculated. Homes were categorized based on three criteria: 1) visible mold damage, 2) moldy odor, and 3) ERMI. Even for homes where families had not moved, Year 7 endotoxin and (1-3)-β-d-glucan exposures were significantly higher than those in Year 1 (pmold damage categories, but were consistently higher in homes with moldy odor and in homes that had high ERMI. Low correlations between results in air and dust samples indicate different types or durations of potential microbial exposures from dust vs. air. Future analysis will indicate which, if any, of the assessment methods is associated with the development of asthma. Copyright © 2010 Elsevier B.V. All rights reserved.

  4. Quantitative Gait Measurement With Pulse-Doppler Radar for Passive In-Home Gait Assessment (United States)

    Skubic, Marjorie; Rantz, Marilyn; Cuddihy, Paul E.


    In this paper, we propose a pulse-Doppler radar system for in-home gait assessment of older adults. A methodology has been developed to extract gait parameters including walking speed and step time using Doppler radar. The gait parameters have been validated with a Vicon motion capture system in the lab with 13 participants and 158 test runs. The study revealed that for an optimal step recognition and walking speed estimation, a dual radar set up with one radar placed at foot level and the other at torso level is necessary. An excellent absolute agreement with intraclass correlation coefficients of 0.97 was found for step time estimation with the foot level radar. For walking speed, although both radars show excellent consistency they all have a system offset compared to the ground truth due to walking direction with respect to the radar beam. The torso level radar has a better performance (9% offset on average) in the speed estimation compared to the foot level radar (13%–18% offset). Quantitative analysis has been performed to compute the angles causing the systematic error. These lab results demonstrate the capability of the system to be used as a daily gait assessment tool in home environments, useful for fall risk assessment and other health care applications. The system is currently being tested in an unstructured home environment. PMID:24771566

  5. Measuring met and unmet need of drug misusers: integration of quantitative and qualitative data. (United States)

    Fountain, J; Strang, J; Griffiths, P; Powis, B; Gossop, M


    This paper reports on the combination of qualitative and quantitative methods which were used to record the attitudes to, and perceptions of, drug treatment services by current, ex-, and potential clients in south-east London. Three research instruments were employed: a structured current client satisfaction survey (n = 333); a questionnaire which included open-ended questions, administered to drug users not currently in treatment (n = 88), and focus groups for young drug users not in treatment (n = 14), women in treatment (n = 7) and men in treatment (n = 11). The data thus collected were used to construct a picture of local met and unmet need and obstacles to the uptake of health care, which is supported by more than one perspective, and which can reasonably be used as the basis for the planning of local health care purchase. Three major concerns were revealed by the data: the inadequacy of existing GP drug services; the deterrent effect of long waiting lists for methadone treatment, and the role of treatment services in relation to those drug users who acknowledge that their drug use is problematic, but believe that treatment services have nothing to offer them. Copyright 2000 S. Karger AG, Basel.

  6. In-situ chemical composition measurements with a laser ablation mass spectrometer for space research: Quantitative investigations of meteorites (United States)

    Neuland, M. B.; Frey, S.; Riedo, A.; Mezger, K.; Wiesendanger, R.; Tulej, M.; Wurz, P.


    We present a laser ablation/ionisation mass spectrometer (LMS). With this instrument we measured the quantitative chemical composition of Allende and Sayh al Uhaymir meteorites in-situ and with very high spatial resolution. From the main rock-forming elements, the mineralogy of the samples was inferred. Measurements of trace elements in SaU allowed dating analyses of the material and the calculation of the crystallisation temperature of the Zircon grains that were identified in the KREEP sample. The measurements on Allende made it possible to analyse the meteorite matrix in particular, beside the various chondrules embedded in the matrix. The LMS is suitable for being operated on a planetary lander or rover, where it would allow for high performance in-situ studies of rocks on the planetary surface.

  7. Comparison of Quality Oncology Practice Initiative (QOPI) Measure Adherence Between Oncology Fellows, Advanced Practice Providers, and Attending Physicians. (United States)

    Zhu, Jason; Zhang, Tian; Shah, Radhika; Kamal, Arif H; Kelley, Michael J


    Quality improvement measures are uniformly applied to all oncology providers, regardless of their roles. Little is known about differences in adherence to these measures between oncology fellows, advance practice providers (APP), and attending physicians. We investigated conformance across Quality Oncology Practice Initiative (QOPI) measures for oncology fellows, advance practice providers, and attending physicians at the Durham Veterans Affairs Medical Center (DVAMC). Using data collected from the Spring 2012 and 2013 QOPI cycles, we abstracted charts of patients and separated them based on their primary provider. Descriptive statistics and the chi-square test were calculated for each QOPI measure between fellows, advanced practice providers (APPs), and attending physicians. A total of 169 patients were reviewed. Of these, 31 patients had a fellow, 39 had an APP, and 99 had an attending as their primary oncology provider. Fellows and attending physicians performed similarly on 90 of 94 QOPI metrics. High-performing metrics included several core QOPI measures including documenting consent for chemotherapy, recommending adjuvant chemotherapy when appropriate, and prescribing serotonin antagonists when prescribing emetogenic chemotherapies. Low-performing metrics included documentation of treatment summary and taking action to address problems with emotional well-being by the second office visit. Attendings documented the plan for oral chemotherapy more often (92 vs. 63%, P=0.049). However, after the chart audit, we found that fellows actually documented the plan for oral chemotherapy 88% of the time (p=0.73). APPs and attendings performed similarly on 88 of 90 QOPI measures. The quality of oncology care tends to be similar between attendings and fellows overall; some of the significant differences do not remain significant after a second manual chart review, highlighting that the use of manual data collection for QOPI analysis is an imperfect system, and there may

  8. Aggression and Quantitative MRI Measures of Caudate in Patients With Chronic Schizophrenia or Schizoaffective Disorder


    Hoptman, Matthew J.; Volavka, Jan; Czobor, Pál; Gerig, Guido; Chakos, Miranda; Blocher, Joseph; Citrome, Leslie L.; Sheitman, Brain; Lindenmayer, Jean-Pierre; Lieberman, Jeffrey A.; Bilder, Robert M.


    Caudate dysfunction is implicated in schizophrenia. However, little is known about the relationship between aggression and caudate volumes. Forty-nine patients received magnetic resonance imaging scanning in a double-blind treatment study in which aggression was measured. Caudate volumes were computed using a semiautomated method. The authors measured aggression with the Overt Aggression Scale and the Positive and Negative Syndrome Scale. Larger caudate volumes were associated with greater le...

  9. The prospects of a quantitative measurement of agility: A validation study on an agile maturity model


    Lucas, Gren; Torkar, Richard; Robert, Feldt


    Agile development has now become a well-known approach to collaboration in professional work life. Both researchers and practitioners want validated tools to measure agility. This study sets out to validate an agile maturity measurement model with statistical tests and empirical data. First, a pretest was conducted as a case study including a survey and focus group. Second, the main study was conducted with 45 employees from two SAP customers in the US. We used internal consistency (by a Cron...

  10. Quantitative measurements of Jupiter, Saturn, their rings and satellites made from Voyager imaging data (United States)

    Collins, S. A.; Bunker, A. S.


    The Voyager spacecraft cameras use selenium-sulfur slow scan vidicons to convert focused optical images into sensible electrical signals. The vidicon-generated data thus obtained are the basis of measurements of much greater precision than was previously possible, in virtue of their superior linearity, geometric fidelity, and the use of in-flight calibration. Attention is given to positional, radiometric, and dynamical measurements conducted on the basis of vidicon data for the Saturn rings, the Saturn satellites, and the Jupiter atmosphere.

  11. Real-time quantitative measurement of the mode beating of an injection-seeded optical parametric oscillator


    Mahnke, Peter; Wirth, Martin


    In this paper we present the dependency of a quantitative measurement of the first-order longitudinal mode beating of an injection-seeded optical parametric oscillator (OPO) on its injection-seeding state. We show the correlation of the intensity of the first-order longitudinal mode beating and the side-mode suppression of an injection-seeded OPO. We further demonstrate that the mode-beating intensity can be used as an indicator for the spectral purity of an injection-seeded OPO.

  12. Quantitative force and dissipation measurements in liquids using piezo-excited atomic force microscopy: a unifying theory. (United States)

    Kiracofe, Daniel; Raman, Arvind


    The use of a piezoelectric element (acoustic excitation) to vibrate the base of microcantilevers is a popular method for dynamic atomic force microscopy. In air or vacuum, the base motion is so small (relative to tip motion) that it can be neglected. However, in liquid environments the base motion can be large and cannot be neglected. Yet it cannot be directly observed in most AFMs. Therefore, in liquids, quantitative force and energy dissipation spectroscopy with acoustic AFM relies on theoretical formulae and models to estimate the magnitude of the base motion. However, such formulae can be inaccurate due to several effects. For example, a significant component of the piezo excitation does not mechanically excite the cantilever but rather transmits acoustic waves through the surrounding liquid, which in turn indirectly excites the cantilever. Moreover, resonances of the piezo, chip and holder can obscure the true cantilever dynamics even in well-designed liquid cells. Although some groups have tried to overcome these limitations (either by theory modification or better design of piezos and liquid cells), it is generally accepted that acoustic excitation is unsuitable for quantitative force and dissipation spectroscopy in liquids. In this paper the authors present a careful study of the base motion and excitation forces and propose a method by which quantitative analysis is in fact possible, thus opening this popular method for quantitative force and dissipation spectroscopy using dynamic AFM in liquids. This method is validated by experiments in water on mica using a scanning laser Doppler vibrometer, which can measure the actual base motion. Finally, the method is demonstrated by using small-amplitude dynamic AFM to extract the force gradients and dissipation on solvation shells of octamethylcyclotetrasiloxane (OMCTS) molecules on mica.

  13. Relationships between diffusing capacity for carbon monoxide (D{sub L}CO), and quantitative computed tomography measurements and visual assessment for chronic obstructive pulmonary disease

    Energy Technology Data Exchange (ETDEWEB)

    Nambu, Atsushi, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Teikyo University Mizonokuchi Hospital (Japan); Zach, Jordan, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Schroeder, Joyce, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Jin, Gong Yong, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Chonbuk National University Hospital (Korea, Republic of); Kim, Song Soo, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States); Department of Radiology, Chungnam National Hospital, Chungnam National University School of Medicine (Korea, Republic of); Kim, Yu-IL, E-mail: [Department of Medicine, National Jewish Health, Denver, CO (United States); Department of Internal Medicine, Chonnam National University Hospital, Gwangju (Korea, Republic of); Schnell, Christina, E-mail: [Department of Medicine, National Jewish Health, Denver, CO (United States); Bowler, Russell, E-mail: [Division of Pulmonary Medicine, Department of Medicine, National Jewish Health (United States); Lynch, David A., E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO 80206 (United States)


    Highlights: • Quantitative CT measurements significantly correlated with D{sub L}CO/V{sub A}. • 15{sup th} percentile HU had the strongest correlation with D{sub L}CO/V{sub A}. • Visual scoring of emphysema had independent significant correlations with D{sub L}CO/V{sub A}. - Abstract: Purpose: To evaluate the relationships between D{sub L}CO, and Quantitative CT (QCT) measurements and visual assessment of pulmonary emphysema and to test the relative roles of visual and quantitative assessment of emphysema. Materials and methods: The subjects included 199 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had diffusing capacity for carbon monoxide corrected for alveolar volume (D{sub L}CO/V{sub A}). Quantitative CT measurements included % low attenuation areas (%LAA−950ins = voxels ≤−950 Hounsfield unit (HU), % LAA{sub −910ins}, and % LAA{sub −856ins}), mean CT attenuation and 15th percentile HU value on inspiratory CT, and %LAA{sub −856exp} (voxels ≤−856 HU on expiratory CT). The extent of emphysema was visually assessed using a 5-point grading system. Univariate and multiple variable linear regression analyses were employed to evaluate the correlations between D{sub L}CO/V{sub A} and QCT parameters and visual extent of emphysema. Results: The D{sub L}CO/V{sub A} correlated most strongly with 15th percentile HU (R{sup 2} = 0.440, p < 0.001) closely followed by % LAA{sub −950ins} (R{sup 2} = 0.417, p < 0.001) and visual extent of emphysema (R{sup 2} = 0.411, p < 0.001). Multiple variable analysis showed that visual extent of emphysema and 15th percentile HU were independent significant predictors of D{sub L}CO/V{sub A} at an R{sup 2} of 0.599. Conclusions: 15th percentile HU seems the best parameter to represent the respiratory condition of COPD. Visual and Quantitative CT assessment of emphysema provide complementary information to QCT analysis.

  14. Assessment of a portable device for the quantitative measurement of ankle joint stiffness in spastic individuals

    DEFF Research Database (Denmark)

    Lorentzen, Jakob; Grey, Michael J; Geertsen, Svend Sparre


    OBJECTIVE: Spasticity is a common complication with neurological diseases and CNS lesions. Instrumented systems to evaluate spasticity often cannot provide an immediate result, thus limiting their clinical usefulness. In this study we investigated the accuracy and reliability of the portable...

  15. Correlation of subjective slipperiness judgements with quantitative COF (Coefficient Of Friction) measurements for structural steel (United States)

    Purswell, Jerry L.; Schlegel, Robert E.


    When there is no simple or accurate procedure for measuring the coefficient of friction (COF) at a job site, workers and/or supervisors involved must make subjective judgments about the slipperiness of the walking and climbing surfaces and in turn decide whether the surface presents a safe or an unsafe condition for work. This project was designed to determine whether these subjective judgment calls did in fact agree with the COF measurements obtained using a mechanical device. It was noted that the coatings chosen for study were subject to a polishing factor by the boot soles during the trials, causing the COF values to become lower as the trials continued. Poor correlation was obtained between subjective ratings of slipperiness and the COF values measured before the trials began. A relatively high correlation was obtained between subjective ratings and the COF values measured after the trials had been completed. A difference was noted in the subjective ratings for the effects of water on a coating for column climbing, but not for walking a beam, suggesting the effects of water on a coating are related to the type of task being performed in steel erection. An increase in the measured COF was noted for all of the coatings when they were wet as compared to the dry condition. The importance of clean shoe soles was clearly demonstrated.

  16. Quantitative Evaluation of Maceration in Venous Leg Ulcers by Transepidermal Water Loss (TEWL) Measurement. (United States)

    Dini, Valentina; Barbanera, Sabrina; Romanelli, Marco


    Skin maceration is a clinical manifestation in venous leg ulcers that leads to severe consequences for patients' quality of life and wound management. The aim of this study was to explore the use of transepidermal water loss (TEWL) measurement technique to quantify different level of surrounding skin maceration in patients with venous leg ulcers. A total of 50 patients were recruited and TEWL measurements were taken with a portable device on different locations surrounding the leg ulcer and on control skin. A clinical score for maceration was used and correlated to the involvement of surrounding skin. Statistically significant differences of TEWL values were noted between affected skin and control site (P maceration clinical score increased (r = 0.954). Objective monitoring of skin maceration in venous leg ulcer with TEWL measurement represents an useful tool to analyze morphologic changes at different time points during treatment. © The Author(s) 2014.

  17. Aggression and quantitative MRI measures of caudate in patients with chronic schizophrenia or schizoaffective disorder. (United States)

    Hoptman, Matthew J; Volavka, Jan; Czobor, Pál; Gerig, Guido; Chakos, Miranda; Blocher, Joseph; Citrome, Leslie L; Sheitman, Brain; Lindenmayer, Jean-Pierre; Lieberman, Jeffrey A; Bilder, Robert M


    Caudate dysfunction is implicated in schizophrenia. However, little is known about the relationship between aggression and caudate volumes. Forty-nine patients received magnetic resonance imaging scanning in a double-blind treatment study in which aggression was measured. Caudate volumes were computed using a semiautomated method. The authors measured aggression with the Overt Aggression Scale and the Positive and Negative Syndrome Scale. Larger caudate volumes were associated with greater levels of aggression. The relationship between aggression and caudate volumes may be related to the iatrogenic effects of long-term treatment with typical antipsychotic agents or to a direct effect of schizophrenic processes on the caudate.

  18. Quantitative computed tomography measurements to evaluate airway disease in chronic obstructive pulmonary disease: Relationship to physiological measurements, clinical index and visual assessment of airway disease

    Energy Technology Data Exchange (ETDEWEB)

    Nambu, Atsushi, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States); Zach, Jordan, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States); Schroeder, Joyce, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States); Jin, Gongyoung, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States); Kim, Song Soo, E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States); Kim, Yu-IL, E-mail: [Department of Medicine, National Jewish Health, Denver, CO (United States); Schnell, Christina, E-mail: [Department of Medicine, National Jewish Health, Denver, CO (United States); Bowler, Russell, E-mail: [Division of Pulmonary Medicine, Department of Medicine, National Jewish Health (United States); Lynch, David A., E-mail: [Department of Radiology, National Jewish Health, 1400 Jackson Street, Denver, CO, 80206 (United States)


    Purpose: To correlate currently available quantitative CT measurements for airway disease with physiological indices and the body-mass index, airflow obstruction, dyspnea, and exercise capacity (BODE) index in patients with chronic obstructive pulmonary disease (COPD). Materials and methods: This study was approved by our institutional review board (IRB number 2778). Written informed consent was obtained from all subjects. The subjects included 188 current and former cigarette smokers from the COPDGene cohort who underwent inspiratory and expiratory CT and also had physiological measurements for the evaluation of airflow limitation, including FEF25-75%, airway resistance (Raw), and specific airway conductance (sGaw). The BODE index was used as the index of clinical symptoms. Quantitative CT measures included % low attenuation areas [% voxels ≤ 950 Hounsfield unit (HU) on inspiratory CT, %LAA{sub −950ins}], percent gas trapping (% voxels ≤ −856 HU on expiratory CT, %LAA {sub −856exp}), relative inspiratory to expiratory volume change of voxels with attenuation values from −856 to −950 HU [Relative Volume Change (RVC){sub −856} {sub to} {sub −950}], expiratory to inspiratory ratio of mean lung density (E/I-ratio {sub MLD}), Pi10, and airway wall thickness (WT), luminal diameter (LD) and airway wall area percent (WA%) in the segmental, subsegmental and subsubsegmental bronchi on inspiratory CT. Correlation coefficients were calculated between the QCT measurements and physiological measurements in all subjects and in the subjects with mild emphysema (%LAA{sub −950ins} <10%). Univariate and multiple variable analysis for the BODE index were also performed. Adjustments were made for age, gender, smoking pack years, FEF25-75%, Raw, and sGaw. Results: Quantitative CT measurements had significant correlations with physiological indices. Among them, E/I-ratio {sub MLD} had the strongest correlations with FEF25-75% (r = −0.648, <0.001) and sGaw (r = −0

  19. A bench-top K X-ray fluorescence system for quantitative measurement of gold nanoparticles for biological sample diagnostics

    Energy Technology Data Exchange (ETDEWEB)

    Ricketts, K., E-mail: [Division of Surgery and Interventional Sciences, University College London, Royal Free Campus, Rowland Hill Street, London NW3 2PF (United Kingdom); Guazzoni, C.; Castoldi, A. [Dipartimento di Elettronica, Informazione e Bioingegneria Politecnico di Milano and INFN, Sezione di Milano Leonardo da Vinci, 32-20133 Milano (Italy); Royle, G. [Department of Medical Physics and Bioengineering, University College London, Malet Place Engineering Building, Gower Street, London WC1E 6BT (United Kingdom)


    Gold nanoparticles can be targeted to biomarkers to give functional information on a range of tumour characteristics. X-ray fluorescence (XRF) techniques offer potential quantitative measurement of the distribution of such heavy metal nanoparticles. Biologists are developing 3D tissue engineered cellular models on the centimetre scale to optimise targeting techniques of nanoparticles to a range of tumour characteristics. Here we present a high energy bench-top K-X-ray fluorescence system designed for sensitivity to bulk measurement of gold nanoparticle concentration for intended use in such thick biological samples. Previous work has demonstrated use of a L-XRF system in measuring gold concentrations but being a low energy technique it is restricted to thin samples or superficial tumours. The presented system comprised a high purity germanium detector and filtered tungsten X-ray source, capable of quantitative measurement of gold nanoparticle concentration of thicker samples. The developed system achieved a measured detection limit of between 0.2 and 0.6 mgAu/ml, meeting specifications of biologists and being approximately one order of magnitude better than the detection limit of alternative K-XRF nanoparticle detection techniques. The scatter-corrected K-XRF signal of gold was linear with GNP concentrations down to the detection limit, thus demonstrating potential in GNP concentration quantification. The K-XRF system demonstrated between 5 and 9 times less sensitivity than a previous L-XRF bench-top system, due to a fundamental limitation of lower photoelectric interaction probabilities at higher K-edge energies. Importantly, the K-XRF technique is however less affected by overlying thickness, and so offers future potential in interrogating thick biological samples.

  20. Facial Phenotyping by Quantitative Photography Reflects Craniofacial Morphology Measured on Magnetic Resonance Imaging in Icelandic Sleep Apnea Patients (United States)

    Sutherland, Kate; Schwab, Richard J.; Maislin, Greg; Lee, Richard W.W.; Benedikstdsottir, Bryndis; Pack, Allan I.; Gislason, Thorarinn; Juliusson, Sigurdur; Cistulli, Peter A.


    Study Objectives: (1) To determine whether facial phenotype, measured by quantitative photography, relates to underlying craniofacial obstructive sleep apnea (OSA) risk factors, measured with magnetic resonance imaging (MRI); (2) To assess whether these associations are independent of body size and obesity. Design: Cross-sectional cohort. Setting: Landspitali, The National University Hospital, Iceland. Participants: One hundred forty patients (87.1% male) from the Icelandic Sleep Apnea Cohort who had both calibrated frontal and profile craniofacial photographs and upper airway MRI. Mean ± standard deviation age 56.1 ± 10.4 y, body mass index 33.5 ± 5.05 kg/m2, with on-average severe OSA (apnea-hypopnea index 45.4 ± 19.7 h-1). Interventions: N/A. Measurements and Results: Relationships between surface facial dimensions (photos) and facial bony dimensions and upper airway soft-tissue volumes (MRI) was assessed using canonical correlation analysis. Photo and MRI craniofacial datasets related in four significant canonical correlations, primarily driven by measurements of (1) maxillary-mandibular relationship (r = 0.8, P photography and MRI. This study confirms that facial photographic phenotype reflects underlying aspects of craniofacial skeletal abnormalities associated with OSA. Therefore, facial photographic phenotyping may be a useful tool to assess intermediate phenotypes for OSA, particularly in large-scale studies. Citation: Sutherland K, Schwab RJ, Maislin G, Lee RW, Benedikstdsottir B, Pack AI, Gislason T, Juliusson S, Cistulli PA. Facial phenotyping by quantitative photography reflects craniofacial morphology measured on magnetic resonance imaging in icelandic sleep apnea patients. SLEEP 2014;37(5):959-968. PMID:24790275

  1. Identification of Phosphoglycerate Kinase 1 (PGK1 as a reference gene for quantitative gene expression measurements in human blood RNA

    Directory of Open Access Journals (Sweden)

    Unger Elizabeth R


    Full Text Available Abstract Background Blood is a convenient sample and increasingly used for quantitative gene expression measurements with a variety of diseases including chronic fatigue syndrome (CFS. Quantitative gene expression measurements require normalization of target genes to reference genes that are stable and independent from variables being tested in the experiment. Because there are no genes that are useful for all situations, reference gene selection is an essential step to any quantitative reverse transcription-PCR protocol. Many publications have described appropriate genes for a wide variety of tissues and experimental conditions, however, reference genes that may be suitable for the analysis of CFS, or human blood RNA derived from whole blood as well as isolated peripheral blood mononuclear cells (PBMCs, have not been described. Findings Literature review and analyses of our unpublished microarray data were used to narrow down the pool of candidate reference genes to six. We assayed whole blood RNA from Tempus tubes and cell preparation tube (CPT-collected PBMC RNA from 46 subjects, and used the geNorm and NormFinder algorithms to select the most stable reference genes. Phosphoglycerate kinase 1 (PGK1 was one of the optimal normalization genes for both whole blood and PBMC RNA, however, additional genes differed for the two sample types; Ribosomal protein large, P0 (RPLP0 for PBMC RNA and Peptidylprolyl isomerase B (PPIB for whole blood RNA. We also show that the use of a single reference gene is sufficient for normalization when the most stable candidates are used. Conclusions We have identified PGK1 as a stable reference gene for use with whole blood RNA and RNA derived from PBMC. When stable genes are selected it is possible to use a single gene for normalization rather than two or three. Optimal normalization will improve the ability of results from PBMC RNA to be compared with those from whole blood RNA and potentially allows comparison of

  2. Quantitative vibro-acoustography of tissue-like objects by measurement of resonant modes. (United States)

    Mazumder, Dibbyan; Umesh, Sharath; Vasu, Ram Mohan; Roy, Debasish; Kanhirodan, Rajan; Asokan, Sundarrajan


    We demonstrate a simple and computationally efficient method to recover the shear modulus pertaining to the focal volume of an ultrasound transducer from the measured vibro-acoustic spectral peaks. A model that explains the transport of local deformation information with the acoustic wave acting as a carrier is put forth. It is also shown that the peaks correspond to the natural frequencies of vibration of the focal volume, which may be readily computed by solving an eigenvalue problem associated with the vibrating region. Having measured the first natural frequency with a fibre Bragg grating sensor, and armed with an expedient means of computing the same, we demonstrate a simple procedure, based on the method of bisection, to recover the average shear modulus of the object in the ultrasound focal volume. We demonstrate this recovery for four homogeneous agarose slabs of different stiffness and verify the accuracy of the recovery using independent rheometer-based measurements. Extension of the method to anisotropic samples through the measurement of a more complete set of resonant modes and the recovery of an elasticity tensor distribution, as is done in resonant ultrasound spectroscopy, is suggested.

  3. TV shearography: quantitative measurement of shear-magnitude fields by use of digital speckle photography. (United States)

    Andersson, A; Krishna Mohan, N; Sjödahl, M; Molin, N E


    Digital speckle photography combined with TV shearography is developed for precise measurement of the magnitude of the shear field in a linear shear configuration. As an application the method is implemented to determine the slope-change variations of a three-dimensional object with TV shearography in which the shear magnitude is obtained with the digital speckle photography technique.

  4. A quantitative introduction of physical safety measures for realising buildings above roads and railway tracks

    NARCIS (Netherlands)

    Suddle, S.I.; Ale, B.J.M.; Waarts, P.H.; Weerheijm, J.


    Buildings above roads and railways are examples of multiple use of space. Safety is one of the critical issues for such projects. This paper will propose effects of safety measures for multiple use of space projects for critical scenarios i.e. fires, explosions, release of toxic substances and

  5. A Quantitative introduction of physical safety measures for realising buildings above roads and railway tracks

    NARCIS (Netherlands)

    Suddle, S.I.; Ale, B.J.M.; Weerheijm, J.; Waarts, P.H.


    Buildings above roads and railways are examples of multiple use of space. Safety is one of the critical issues for such projects. This paer will propose effects of safety measures for multiple use of space projects for critical scenarios i.e. fires, explosions, release of toxic substances and

  6. Orientation on quantitative IR-thermografy in wall-shear stress measurements

    NARCIS (Netherlands)

    Mayer, R.


    Wall-shear stresses are highly important in the aerodynamic design of aircraft, because they determine the drag and thus the fuel consumption of an airplane. Due to this importance many different measurement techniques have been developed. Most of these techniques are intrusive, which means that the


    NARCIS (Netherlands)


    Fluoride in solution is most usually measured with the ion-specific electrode, although a few other methods are available. The electrode can be used in a straightforward manner, its lower concentration limit may be extended by special methods such as the standard addition of fluoride, or

  8. Quantitative measures of the effect of the melanocortin 1 receptor on human pigmentary status. (United States)

    Naysmith, Lisa; Waterston, Karen; Ha, Tom; Flanagan, Niamh; Bisset, Yvonne; Ray, Amanda; Wakamatsu, Kazumasa; Ito, Shosuke; Rees, Jonathan L


    Variation in human hair and skin color is the most striking visible aspect of human genetic variation. The only gene known to exert an effect on pigmentary within the normal population is the melanocortin-1 receptor (MC1R). Previous studies have used a Mendelian framework to relate MC1R genotype to phenotype, by measuring pigmentary status using categorical scales. Such approaches are inadequate. We report results using direct measures of hair color using objective colorimetric dimensions and HPLC determined hair melanins. We have linked MC1R genotype with chemical measures of melanin quantity and type and objective phenotype measures of color. MC1R genotype was predictive of hair melanin expressed as the ratio of the loge of eumelanin to pheomelanin ratio, with a dosage effect evident: MC1R homozygote mean, 1.46; heterozygote, 4.44; and wild type, 5.81 (pcolor, most prominently for the b* axis (p<0.001), but also for the a* and L* scales (L*a*b*, CIE). We show for one of the most polymorphic human traits that it is possible to demonstrate meaningful relations between various physical characteristics: DNA sequence diversity, hair-wavelength-specific reflectance patterns, and chemical melanin assays.

  9. A new soil test for quantitative measurement of available and adsorbed boron (United States)

    Boron soil tests currently in use, do not extract all plant available B but are used by relating the extractable amount of B to plant B content. There is a need to accurately measure all plant available or adsorbed B because B can be toxic to plants at elevated concentrations and can cause marked y...

  10. Quantitative FRET measurement using emission-spectral unmixing with independent excitation crosstalk correction. (United States)

    Zhang, J; Li, H; Chai, L; Zhang, L; Qu, J; Chen, T


    Quantification of fluorescence resonance energy transfer (FRET) needs at least two external samples, an acceptor-only reference and a linked FRET reference, to calibrate fluorescence signal. Furthermore, all measurements for references and FRET samples must be performed under the same instrumental conditions. Based on a novel notion to predetermine the molar extinction coefficient ratio (RC ) of acceptor-to-donor for the correction of acceptor excitation crosstalk, we present here a robust and independent emission-spectral unmixing FRET methodology, Iem-spFRET, which can simultaneously measure the E and RC of FRET sample without any external references, such that Iem-spFRET circumvents the rigorous restriction of keeping the same imaging conditions for all FRET experiments and thus can be used for the direct measurement of FRET sample. We validate Iem-spFRET by measuring the absolute E and RC values of standard constructs with different acceptor-to-donor stoichiometry expressed in living cells. Our results demonstrate that Iem-spFRET is a simple and powerful tool for real-time monitoring the dynamic intermolecular interaction within single living cells. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

  11. A Critical Evaluation of Quantitative Measures of the Quality of Arts and Culture

    DEFF Research Database (Denmark)

    Bille, Trine

    Art and culture i.e. theatre, film, music, visual art, literature, cultural heritage etc. and related institutions and participants, have traditionally not been measured and evaluated in the same way as other sectors. The reason for this is perhaps that art and culture cannot be ‘weighed...

  12. Measurement issues associated with quantitative molecular biology analysis of complex food matrices for the detection of food fraud. (United States)

    Burns, Malcolm; Wiseman, Gordon; Knight, Angus; Bramley, Peter; Foster, Lucy; Rollinson, Sophie; Damant, Andrew; Primrose, Sandy


    Following a report on a significant amount of horse DNA being detected in a beef burger product on sale to the public at a UK supermarket in early 2013, the Elliott report was published in 2014 and contained a list of recommendations for helping ensure food integrity. One of the recommendations included improving laboratory testing capacity and capability to ensure a harmonised approach for testing for food authenticity. Molecular biologists have developed exquisitely sensitive methods based on the polymerase chain reaction (PCR) or mass spectrometry for detecting the presence of particular nucleic acid or peptide/protein sequences. These methods have been shown to be specific and sensitive in terms of lower limits of applicability, but they are largely qualitative in nature. Historically, the conversion of these qualitative techniques into reliable quantitative methods has been beset with problems even when used on relatively simple sample matrices. When the methods are applied to complex sample matrices, as found in many foods, the problems are magnified resulting in a high measurement uncertainty associated with the result which may mean that the assay is not fit for purpose. However, recent advances in the technology and the understanding of molecular biology approaches have further given rise to the re-assessment of these methods for their quantitative potential. This review focuses on important issues for consideration when validating a molecular biology assay and the various factors that can impact on the measurement uncertainty of a result associated with molecular biology approaches used in detection of food fraud, with a particular focus on quantitative PCR-based and proteomics assays.

  13. Multi-slice echo-planar spectroscopic MR imaging provides both global and local metabolite measures in multiple sclerosis

    DEFF Research Database (Denmark)

    Mathiesen, Henrik Kahr; Tscherning, Thomas; Sorensen, Per Soelberg


    MR spectroscopy (MRS) provides information about neuronal loss or dysfunction by measuring decreases in N-acetyl aspartate (NAA), a metabolite widely believed to be a marker of neuronal viability. In multiple sclerosis (MS), whole-brain NAA (WBNAA) has been suggested as a marker of disease progre...

  14. Multiwavelength shearography for quantitative measurements of two-dimensional strain distributions. (United States)

    Kästle, R; Hack, E; Sennhauser, U


    We report on the development of a multiwavelength speckle pattern shearing interferometer for the determination of two-dimensional strain distributions. This system is based on simultaneous illumination of the object with three diode lasers that emit at different wavelengths between 800 and 850 nm. Wavelength separation and image acquisition were performed with a special optical arrangement, including narrow-bandpass filters and three black-and-white cameras. The shearographic camera with a variable shearing element, in combination with the appropriate illumination geometry, permitted us to isolate all six displacement derivatives from phase-stepped fringe patterns. The optical system and the measurement procedure were validated with two different experiments. First, the shearographic sensor head was used for the determination of in-plane displacements, and, second, in-plane strain distributions of an aluminum block caused by temperature expansion were measured.

  15. A study on quantitative measurement of internal defects of pressure vessel by digital shearography

    Energy Technology Data Exchange (ETDEWEB)

    Park, Sung Tae; Kang, Young Jun; Jang, Jong Min [Chonbuk National University, Chonju (Korea, Republic of)


    Pipelines in power plants, nuclear facilities and chemical industries are often affected by corrosion effects. It is very important in detect such internal flaws of pipelines because they sometimes bring about serious problems. Conventional NDT methods have been taken relatively much time, money, and manpower because of performing as the method of contact with objects to be inspected. Digital shearography is a laser-based optical method which allows full-field observation of surface displacement derivatives. This method has many advantages in practical use, such as low sensitivity to environmental noise, simple optical configuration and real time measurement. In this paper, the experiment was performed with some pressure vessels which has different internal cracks. We measured internal crack length of the pressure vessels at a real time and compared with FEM simulation results.

  16. Differences in quantitative methods for measuring subjective cognitive decline - results from a prospective memory clinic study

    DEFF Research Database (Denmark)

    Vogel, Asmus; Salem, Lise Cronberg; Andersen, Birgitte Bo


    decline. Depression scores were significantly correlated to both scales measuring subjective decline. Linear regression models showed that age did not have a significant contribution to the variance in subjective memory beyond that of depressive symptoms. CONCLUSIONS: Measures for subjective cognitive......BACKGROUND: Cognitive complaints occur frequently in elderly people and may be a risk factor for dementia and cognitive decline. Results from studies on subjective cognitive decline are difficult to compare due to variability in assessment methods, and little is known about how different methods...... influence reports of cognitive decline. METHODS: The Subjective Memory Complaints Scale (SMC) and The Memory Complaint Questionnaire (MAC-Q) were applied in 121 mixed memory clinic patients with mild cognitive symptoms (mean MMSE = 26.8, SD 2.7). The scales were applied independently and raters were blinded...

  17. RAPID COMMUNICATION: A TALIF calibration method for quantitative oxygen atom density measurement in plasma jets (United States)

    Dilecce, G.; Vigliotti, M.; DeBenedictis, S.


    In this communication we propose a calibration method for two-photon absorption laser induced fluorescence (TALIF). It can be carried out without any addition or modification to the O atom TALIF set-up. It is based on the measurement of the collision quenching of the laser-excited state (3p3 P2 ) in a pure O2 system in which a high dissociation degree can be achieved. Since the collision rate constant by O is largely lower than that by O2 , the quenching rate can be correlated to the O density. The incertitude in this procedure is comparable to other calibration techniques. We have applied this method to the spatially resolved measurement of O atom density in an O2 rf plasma jet.

  18. Quantitative evaluation of three-dimensional facial scanners measurement accuracy for facial deformity (United States)

    Zhao, Yi-jiao; Xiong, Yu-xue; Sun, Yu-chun; Yang, Hui-fang; Lyu, Pei-jun; Wang, Yong


    Objective: To evaluate the measurement accuracy of three-dimensional (3D) facial scanners for facial deformity patients from oral clinic. Methods: 10 patients in different types of facial deformity from oral clinical were included. Three 3D digital face models for each patient were obtained by three facial scanners separately (line laser scanner from Faro for reference, stereophotography scanner from 3dMD and structured light scanner from FaceScan for test). For each patient, registration based on Iterative Closest Point (ICP) algorithm was executed to align two test models (3dMD data & Facescan data) to the reference models (Faro data in high accuracy) respectively. The same boundaries on each pair models (one test and one reference models) were obtained by projection function in Geomagic Stuido 2012 software for trimming overlapping region, then 3D average measurement errors (3D errors) were calculated for each pair models also by the software. Paired t-test analysis was adopted to compare the 3D errors of two test facial scanners (10 data for each group). 3D profile measurement accuracy (3D accuracy) that is integrated embodied by average value and standard deviation of 10 patients' 3D errors were obtained by surveying analysis for each test scanner finally. Results: 3D accuracies of 2 test facial scanners in this study for facial deformity were 0.44+/-0.08 mm and 0.43+/-0.05 mm. The result of structured light scanner was slightly better than stereophotography scanner. No statistical difference between them. Conclusions: Both test facial scanners could meet the accuracy requirement (0.5mm) of 3D facial data acquisition for oral clinic facial deformity patients in this study. Their practical measurement accuracies were all slightly lower than their nominal accuracies.

  19. A quantitative approach to measure road network information based on edge diversity (United States)

    Wu, Xun; Zhang, Hong; Lan, Tian; Cao, Weiwei; He, Jing


    The measure of map information has been one of the key issues in assessing cartographic quality and map generalization algorithms. It is also important for developing efficient approaches to transfer geospatial information. Road network is the most common linear object in real world. Approximately describe road network information will benefit road map generalization, navigation map production and urban planning. Most of current approaches focused on node diversities and supposed that all the edges are the same, which is inconsistent to real-life condition, and thus show limitations in measuring network information. As real-life traffic flow are directed and of different quantities, the original undirected vector road map was first converted to a directed topographic connectivity map. Then in consideration of preferential attachment in complex network study and rich-club phenomenon in social network, the from and to weights of each edge are assigned. The from weight of a given edge is defined as the connectivity of its end node to the sum of the connectivities of all the neighbors of the from nodes of the edge. After getting the from and to weights of each edge, edge information, node information and the whole network structure information entropies could be obtained based on information theory. The approach has been applied to several 1 square mile road network samples. Results show that information entropies based on edge diversities could successfully describe the structural differences of road networks. This approach is a complementarity to current map information measurements, and can be extended to measure other kinds of geographical objects.

  20. The quantitative measurement of magnetic moments from phase images of nanoparticles and nanostructures – I. Fundamentals

    DEFF Research Database (Denmark)

    Beleggia, Marco; Kasama, Takeshi; Dunin-Borkowski, Rafal E.


    the structure of interest. The quantity obtained is found to be directly proportional to the magnetic moment of the particle, with a constant of proportionality that does not depend on the particle's shape or magnetization state. The measurement of magnetic moments from both simulated and experimental phase...... images is demonstrated, and strategies are presented that can be utilized to overcome sources of error associated with, for example, the presence of neighboring magnetic particles and the perturbation of the holographic reference wave...

  1. Measurement of lentiviral vector titre and copy number by cross-species duplex quantitative PCR


    Christodoulou, I.; Patsali, P; Stephanou, C.; Antoniou, M; Kleanthous, M; Lederer, C. W.


    Lentiviruses are the vectors of choice for many preclinical studies and clinical applications of gene therapy. Accurate measurement of biological vector titre before treatment is a prerequisite for vector dosing, and the calculation of vector integration sites per cell after treatment is as critical to the characterisation of modified cell products as it is to long-term follow-up and the assessment of risk and therapeutic efficiency in patients. These analyses are typically based on quantitat...

  2. Implementation of a metrology programme to provide traceability for radionuclides activity measurements in the CNEN Radiopharmaceuticals Producers Centers

    Energy Technology Data Exchange (ETDEWEB)

    Andrade, Erica A.L. de; Braghirolli, Ana M.S.; Tauhata, Luiz; Gomes, Regio S.; Silva, Carlos J., E-mail: [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Delgado, Jose U.; Oliveira, Antonio E.; Iwahara, Akira, E-mail: [Instituto de Radioprotecao e Dosimetria (IRD/CNEN-RJ), Rio de Janeiro, RJ (Brazil)


    The commercialization and use of radiopharmaceuticals in Brazil are regulated by Agencia Nacional de Vigilancia Sanitaria (ANVISA) which require Good Manufacturing Practices (GMP) certification for Radiopharmaceuticals Producer Centers. Quality Assurance Program should implement the GMP standards to ensure radiopharmaceuticals have requirements quality to proving its efficiency. Several aspects should be controlled within the Quality Assurance Programs, and one of them is the traceability of the Radionuclides Activity Measurement in radiopharmaceuticals doses. The quality assurance of activity measurements is fundamental to maintain both the efficiency of the nuclear medicine procedures and patient and exposed occupationally individuals safety. The radiation doses received by patients, during the nuclear medicine procedures, is estimated according to administered radiopharmaceuticals quantity. Therefore it is very important either the activity measurements performed in radiopharmaceuticals producer centers (RPC) as the measurements performed in nuclear medicine services are traceable to national standards. This paper aims to present an implementation program to provide traceability to radionuclides activity measurements performed in the dose calibrators(well type ionization chambers) used in Radiopharmaceuticals Producer Center placed in different states in Brazil. The proposed program is based on the principles of GM Pand ISO 17025 standards. According to dose calibrator performance, the RPC will be able to provide consistent, safe and effective radioactivity measurement to the nuclear medicine services. (author)

  3. System for quantitative measurements of methane emission from dairy cattle in Denmark

    DEFF Research Database (Denmark)

    Hellwing, Anne Louise Frydendahl; Lund, Peter; Johannes, Maike

    The methane emission from the digestive tract of cattle in Denmark accounts for 45% of the total methane emission based on the assumption that 6% of the gross energy is metabolized to methane. There is a lack of newer experimental data available for Danish cattle; therefore we have built a unit f...... expectations for a system for exact measurements of methane emission in dairy cows at production level under close to natural in barn conditions, where cows’ behavior can be expected to be natural.......The methane emission from the digestive tract of cattle in Denmark accounts for 45% of the total methane emission based on the assumption that 6% of the gross energy is metabolized to methane. There is a lack of newer experimental data available for Danish cattle; therefore we have built a unit...... the chamber air. The system constitutes of four chambers, flow meters and gas sensors for measuring methane, oxygen and carbon dioxide. The outside measurements of chambers are approximately 1.45 * 3.9 * 2.45 meters. Inside there is a platform to give the cows a comfortable laying area, space for feeding bin...

  4. Quantitative Aortic Distensibility Measurement Using CT in Patients with Abdominal Aortic Aneurysm: Reproducibility and Clinical Relevance

    Directory of Open Access Journals (Sweden)

    Yunfei Zha


    Full Text Available Purpose. To investigate the reproducibility of aortic distensibility (D measurement using CT and assess its clinical relevance in patients with infrarenal abdominal aortic aneurysm (AAA. Methods. 54 patients with infrarenal abdominal aortic aneurysm were studied to determine their distensibility by using 64-MDCT. Aortic cross-sectional area changes were determined at two positions of the aorta, immediately below the lowest renal artery (level 1. and at the level of its maximal diameter (level 2. by semiautomatic segmentation. Measurement reproducibility was assessed using intraclass correlation coefficient (ICC and Bland-Altman analyses. Stepwise multiple regression analysis was performed to assess linear associations between aortic D and anthropometric and biochemical parameters. Results. A mean distensibility of Dlevel  1.=(1.05±0.22×10-5  Pa-1 and Dlevel  2.=(0.49±0.18×10-5  Pa-1 was found. ICC proved excellent consistency between readers over two locations: 0.92 for intraobserver and 0.89 for interobserver difference in level 1. and 0.85 and 0.79 in level 2. Multivariate analysis of all these variables showed sac distensibility to be independently related (R2=0.68 to BMI, diastolic blood pressure, and AAA diameter. Conclusions. Aortic distensibility measurement in patients with AAA demonstrated high inter- and intraobserver agreement and may be valuable when choosing the optimal dimensions graft for AAA before endovascular aneurysm repair.

  5. Measuring of foot plantar pressure—possible applications in quantitative analysis of human body mobility (United States)

    Klimiec, E.; Jasiewicz, B.; Piekarski, J.; Zaraska, K.; Guzdek, P.; Kołaszczyński, G.


    The paper presents an evaluation of human mobility by gait analysis, carried out in natural conditions (outside of the laboratory). Foot plantar pressure is measured using a shoe insole with 8 sensors placed in different anatomical zones of the foot, and placed inside a sports shoe. Polarized polyvinylidene fluoride (PVDF) foil is used as a sensor material. A wireless transmission system is used to transmit voltage values to the computer. Miniaturization was the priority during the design of the system. Due to the linear relationship between force and transducer voltage, energy and power released during walking in arbitrary units can be calculated as an integral of the square of the transducer voltage over time. Gait measurements were carried out over several days on healthy persons during normal walking and slow walking. The performed measurements allowed for the determination of walking speed (number of steps per second), gait rhythm and manner of walking (applying force to inside versus outside part of the sole). It was found that switching from normal to slow walk increases gait energy by 25% while the pressure distribution across the anatomical regions of the foot remains unchanged. The results will be used to develop a programme for the evaluation of patients with orthopedic diseases or even with cardiac failures, for an estimation of the results of health recovery and training efficiency in many sports activities.

  6. Measurement of bone marrow lesions by MR imaging in knee osteoarthritis: The sensitivity to change assessed by two quantitative methods

    DEFF Research Database (Denmark)

    Nielsen, Flemming Kromann; Jurik, Anne Grethe; Peters, David Alberg


    Purpose: To compare two quantitative methods of measuring BMLs in knee osteoarthritis (KOA), one with computer assisted automatic segmentation (CAS) and one with manual segmentation (MS). Methods and Materials: Eighteen females and four males (mean age 61 years) with KOA confined to the medial...... values and standard deviations (STD) of the signal intensity (SI) of the normal marrow of the lateral femoral and tibial condyles were obtained by both methods. In three slices of the medial femoral condyle the volume of bone marrow with SIs exceeding the threshold values (BML) were measured. Threshold.......8 %, using CAS and MS, respectively. The two methods were thus not comparable; the CAS method recorded the volume of voxels exceeding the threshold values whereas manual segmentation included varying, up to 70 % voxels with normal SI. The inter-observer agreement was best by CAS with bias values of −0.1– 0...

  7. Effects of geomagnetic activity and atmospheric power variations on quantitative measures of brain activity: Replication of the Azerbaijani studies (United States)

    Mulligan, Bryce P.; Hunter, Mathew D.; Persinger, Michael A.


    This study replicates and extends the observations by Babayev and Allahveriyeva that changes in right hemispheric electroencephalographic activity are correlated with increases in geomagnetic activity. During the geomagnetically quiet interface between solar cycle 23 and 24 quantitative electroencephalographic (QEEG) measurements were completed for normal young adults in three separate experiments involving about 120 samples over 1.5 years. The most consistent, moderate strength correlations occurred for the changes in power within the gamma and theta ranges over the right frontal lobe. Real-time measures of atmospheric power obtained from polar orbiting satellites showed similar effects. The preferential involvement of the right frontal lobe and the regions subject to its inhibition with environmental energetic changes are consistent with the behavioural correlations historically associated with these conditions. They include increased incidence of emotional lability, erroneous reconstruction of experiences, social confrontations, and unusual perceptions.

  8. Defining bipolar mood states with quantitative measurement of inhibition/activation and emotional reactivity.


    Henry, Chantal; M'Bailara, Katia; Lépine, Jean-Pierre; Lajnef, Mohamed; Leboyer, Marion


    International audience; The MATHYS scale, providing a score for inhibition/activation process and a score for emotional reactivity, is clearly useful to distinguish bipolar depressive episodes without manic symptoms from those with manic symptoms. This last type of depression appears to belong to a broad spectrum of mixed state. To go further we need to explore if these two types of depression are underlined by different mechanisms and what is the most appropriate treatment for each of them.

  9. Health care providers' perceptions of and attitudes towards induced abortions in sub-Saharan Africa and Southeast Asia : a systematic literature review of qualitative and quantitative data.


    Rehnstr?m Loi, Ulrika; Gemzell-Danielsson, Kristina; Faxelid, Elisabeth; Klingberg-Allvin, Marie


    Background Unsafe abortions are a serious public health problem and a major human rights issue. In low-income countries, where restrictive abortion laws are common, safe abortion care is not always available to women in need. Health care providers have an important role in the provision of abortion services. However, the shortage of health care providers in low-income countries is critical and exacerbated by the unwillingness of some health care providers to provide abortion services. The aim...

  10. Quantitative Measurement of Soot Concentration by Two-Wavelength Correction of Laser-Induced Incandescence Signals

    Energy Technology Data Exchange (ETDEWEB)

    Jung, J. S. [Korea Institute of Science and Technology, Seoul (Korea, Republic of)


    To quantify the L II signals from soot particle of flames in diesel engine cylinder, a new method has been proposed for correcting L II signal attenuated by soot particles between the measuring point and the detector. It has been verified by an experiment on a laminar jet ethylene-air diffusion flame. Being proportional to the attenuation, the ratio of L II signal at two different detection wavelengths can be used to correct the measured L II signal and obtain the unattenuated L II signal, from which the soot volume fraction in the flame can be estimated. Both the 1064-nm and frequency-doubled 532-nm beams from the Nd : YAG laser are used. Single-shot, one-dimensional(1-D) line images are recorded on the intensified CCD camera, with the rectangular-profile laser beam using 1-mm-diameter pinhole. Two broadband optical interference filters having the center wavelengths of 647 nm and 400nm respectively and a bandwidth of 10 nm are used. This two wavelength correction has been applied to the ethylene-air coannular laminar diffusion flame, previously studied on soot formation by the laser extinction method in this laboratory. The results by the L II measurement technique and the conventional laser extinction method at the height of 40 nm above the jet exit agreed well with each other except around outside of the peaks of soot concentration, where the soot concentration was relatively high and resulting attenuation of the L II signal was large. The radial profile shape of soot concentration was not changed a lot, but the absolute value of the soot volume fraction around outside edge changed from 4 ppm to 6.5 ppm at r=2.8 mm after correction. This means that the attenuation of L II signal was approximately 40% at this point, which is higher than the average attenuation rate of this flame, 10 {approx} 15%. (author). 15 refs., 8 figs.

  11. A high precision method for quantitative measurements of reactive oxygen species in frozen biopsies.

    Directory of Open Access Journals (Sweden)

    Kirsti Berg

    Full Text Available OBJECTIVE: An electron paramagnetic resonance (EPR technique using the spin probe cyclic hydroxylamine 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH was introduced as a versatile method for high precision quantification of reactive oxygen species, including the superoxide radical in frozen biological samples such as cell suspensions, blood or biopsies. MATERIALS AND METHODS: Loss of measurement precision and accuracy due to variations in sample size and shape were minimized by assembling the sample in a well-defined volume. Measurement was carried out at low temperature (150 K using a nitrogen flow Dewar. The signal intensity was measured from the EPR 1st derivative amplitude, and related to a sample, 3-carboxy-proxyl (CP• with known spin concentration. RESULTS: The absolute spin concentration could be quantified with a precision and accuracy better than ±10 µM (k = 1. The spin concentration of samples stored at -80°C could be reproduced after 6 months of storage well within the same error estimate. CONCLUSION: The absolute spin concentration in wet biological samples such as biopsies, water solutions and cell cultures could be quantified with higher precision and accuracy than normally achievable using common techniques such as flat cells, tissue cells and various capillary tubes. In addition; biological samples could be collected and stored for future incubation with spin probe, and also further stored up to at least six months before EPR analysis, without loss of signal intensity. This opens for the possibility to store and transport incubated biological samples with known accuracy of the spin concentration over time.

  12. The Q-CHAT (Quantitative CHecklist for Autism in Toddlers): A Normally Distributed Quantitative Measure of Autistic Traits at 18-24 Months of Age--Preliminary Report (United States)

    Allison, Carrie; Baron-Cohen, Simon; Wheelwright, Sally; Charman, Tony; Richler, Jennifer; Pasco, Greg; Brayne, Carol


    We report a major revision of the CHecklist for Autism in Toddlers (CHAT). This "quantitative" CHAT (Q-CHAT) contains 25 items, scored on a 5 point scale (0-4). The Q-CHAT was completed by parents of n = 779 unselected toddlers (mean age 21 months) and n = 160 toddlers and preschoolers (mean age 44 months) with an Autism Spectrum…

  13. Flow bioreactor design for quantitative measurements over endothelial cells using micro-particle image velocimetry. (United States)

    Leong, Chia Min; Voorhees, Abram; Nackman, Gary B; Wei, Timothy


    Mechanotransduction in endothelial cells (ECs) is a highly complex process through which cells respond to changes in hemodynamic loading by generating biochemical signals involving gene and protein expression. To study the effects of mechanical loading on ECs in a controlled fashion, different in vitro devices have been designed to simulate or replicate various aspects of these physiological phenomena. This paper describes the design, use, and validation of a flow chamber which allows for spatially and temporally resolved micro-particle image velocimetry measurements of endothelial surface topography and stresses over living ECs immersed in pulsatile flow. This flow chamber also allows the study of co-cultures (i.e., ECs and smooth muscle cells) and the effect of different substrates (i.e., coverslip and∕or polyethylene terepthalate (PET) membrane) on cellular response. In this report, the results of steady and pulsatile flow on fixed endothelial cells seeded on PET membrane and coverslip, respectively, are presented. Surface topography of ECs is computed from multiple two-dimensional flow measurements. The distributions of shear stress and wall pressure on each individual cell are also determined and the importance of both types of stress in cell remodeling is highlighted.

  14. Quantitative measurement of odor detection thresholds using an air dilution olfactometer, and association with genetic variants in a sample of diverse ancestry

    Directory of Open Access Journals (Sweden)

    Gillian R. Cook


    Full Text Available Genetic association studies require a quantitative and reliable method for odor threshold assessment in order to examine the contribution of genetic variants to complex olfactory phenotypes. Our main goal was to assess the feasibility of a portable Scentroid air dilution olfactometer for use in such studies. Using the Scentroid SM110C and the SK5 n-butanol Sensitivity Kit (IDES Canada Inc., n-butanol odor thresholds were determined for 182 individuals of diverse ancestry (mean age: 20.4 ± 2.5 years; n = 128 female; n = 54 male. Threshold scores from repeat participants were used to calculate a test–retest reliability coefficient, which was statistically significant (r = 0.754, p < 0.001, n = 29, indicating that the Scentroid provides reliable estimates of odor thresholds. In addition, we performed a preliminary genetic analysis evaluating the potential association of n-butanol odor thresholds to six single-nucleotide polymorphisms (SNPs putatively involved in general olfactory sensitivity (GOS. The results of multiple linear regression analysis revealed no significant association between the SNPs tested and threshold scores. However, our sample size was relatively small, and our study was only powered to identify genetic markers with strong effects on olfactory sensitivity. Overall, we find that the Scentroid provides reliable quantitative measures of odor detection threshold and is well suited for genetic studies of olfactory sensitivity.

  15. Quantitative renal perfusion measurements in a rat model of acute kidney injury at 3T: testing inter- and intramethodical significance of ASL and DCE-MRI

    National Research Council Canada - National Science Library

    Zimmer, Fabian; Zöllner, Frank G; Hoeger, Simone; Klotz, Sarah; Tsagogiorgas, Charalambos; Krämer, Bernhard K; Schad, Lothar R


    To establish arterial spin labelling (ASL) for quantitative renal perfusion measurements in a rat model at 3 Tesla and to test the diagnostic significance of ASL and dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI...

  16. Quantitative Characterization Of The Interactions Of Some Glycolytic Enzymes: An Application Of The Fluorescence Anisotropy Measurement (United States)

    Tompa, Peter; Bar, Jorg; Batke, Jozsef


    The affinity of Saccharomyces cerevisiae fructose-1,6-bisphosphate aldolase towards the metabolically related enzymes phosphofructokinase (PFK), triosephosphate isomerase (TPI) and glyceraldehyde-3-phosphate dehydrogenase (GPDH) was tested by using the signal of fluorescein isothiocyanate (FITC) attached covalently to the aldolase. The dissociation constants of the enzyme-enzyme complexes and rate constants of their formation and dissociation were measured and compared with the same parameters derived for enzymes from rabbit muscle. Hybrid complex formation between yeast aldolase and muscle GPDH and between muscle aldolase and yeast GPDH have also been observed. From the similarities in the determined parameters for the yeast and muscle enzymes we concluded that organization based on direct enzyme-enzyme interactions may be an ancient characteristic of the cytoplasm. The existence of in vitro hybrid complexes indicates that the recognition sites responsible for these interactions may have been conserved during the evolution.

  17. Quantitative Limits on Small Molecule Transport via the Electropermeome - Measuring and Modeling Single Nanosecond Perturbations. (United States)

    Sözer, Esin B; Levine, Zachary A; Vernier, P Thomas


    The detailed molecular mechanisms underlying the permeabilization of cell membranes by pulsed electric fields (electroporation) remain obscure despite decades of investigative effort. To advance beyond descriptive schematics to the development of robust, predictive models, empirical parameters in existing models must be replaced with physics- and biology-based terms anchored in experimental observations. We report here absolute values for the uptake of YO-PRO-1, a small-molecule fluorescent indicator of membrane integrity, into cells after a single electric pulse lasting only 6 ns. We correlate these measured values, based on fluorescence microphotometry of hundreds of individual cells, with a diffusion-based geometric analysis of pore-mediated transport and with molecular simulations of transport across electropores in a phospholipid bilayer. The results challenge the "drift and diffusion through a pore" model that dominates conventional explanatory schemes for the electroporative transfer of small molecules into cells and point to the necessity for a more complex model.

  18. Single x-ray absorptiometry method for the quantitative mammographic measure of fibroglandular tissue volume

    Energy Technology Data Exchange (ETDEWEB)

    Malkov, Serghei; Wang, Jeff; Kerlikowske, Karla; Cummings, Steven R.; Shepherd, John A. [Department of Radiology and Biomedical Imaging, University of California-San Francisco, San Francisco, California 94143 (United States); Departments of Medicine and Epidemiology and Biostatistics, University of California-San Francisco, San Francisco, California 94143 (United States); Research Institute, California Pacific Medical Center, San Francisco, California 94143 (United States); Department of Radiology and Biomedical Imaging, University of California--San Francisco, San Francisco, California 94143 (United States)


    Purpose: This study describes the design and characteristics of a highly accurate, precise, and automated single-energy method to quantify percent fibroglandular tissue volume (%FGV) and fibroglandular tissue volume (FGV) using digital screening mammography. Methods: The method uses a breast tissue-equivalent phantom in the unused portion of the mammogram as a reference to estimate breast composition. The phantom is used to calculate breast thickness and composition for each image regardless of x-ray technique or the presence of paddle tilt. The phantom adheres to the top of the mammographic compression paddle and stays in place for both craniocaudal and mediolateral oblique screening views. We describe the automated method to identify the phantom and paddle orientation with a three-dimensional reconstruction least-squares technique. A series of test phantoms, with a breast thickness range of 0.5-8 cm and a %FGV of 0%-100%, were made to test the accuracy and precision of the technique. Results: Using test phantoms, the estimated repeatability standard deviation equaled 2%, with a {+-}2% accuracy for the entire thickness and density ranges. Without correction, paddle tilt was found to create large errors in the measured density values of up to 7%/mm difference from actual breast thickness. This new density measurement is stable over time, with no significant drifts in calibration noted during a four-month period. Comparisons of %FGV to mammographic percent density and left to right breast %FGV were highly correlated (r=0.83 and 0.94, respectively). Conclusions: An automated method for quantifying fibroglandular tissue volume has been developed. It exhibited good accuracy and precision for a broad range of breast thicknesses, paddle tilt angles, and %FGV values. Clinical testing showed high correlation to mammographic density and between left and right breasts.

  19. MR measurement of luminal water in prostate gland: Quantitative correlation between MRI and histology. (United States)

    Sabouri, Shirin; Fazli, Ladan; Chang, Silvia D; Savdie, Richard; Jones, Edward C; Goldenberg, S Larry; Black, Peter C; Kozlowski, Piotr


    To determine the relationship between parameters measured from luminal water imaging (LWI), a new magnetic resonance imaging (MRI) T2 mapping technique, and the corresponding tissue composition in prostate. In all, 17 patients with prostate cancer were examined with a 3D multiecho spin echo sequence at 3T prior to undergoing radical prostatectomy. Maps of seven MR parameters, called N, T2-short , T2-long , Ashort , Along , geometric mean T2 time (gmT2 ), and luminal water fraction (LWF), were generated using nonnegative least squares (NNLS) analysis of the T2 decay curves. MR parametric maps were correlated to digitized whole-mount histology sections. Percentage area of tissue components, including luminal space, nuclei, and cytoplasm plus stroma, was measured on the histology sections by using color-based image segmentation. Spearman's rank correlation test was used to evaluate the correlation between MR parameters and the corresponding tissue components, with particular attention paid to the correlation between LWF and percentage area of luminal space. N, T2-short , Along , gmT2 , and LWF showed significant correlation (P correlation (P correlation was observed between LWF and luminal space (Spearman's coefficient of rank correlation = 0.75, P correlated with the fractional amount of luminal space in prostatic tissue. This result suggests that LWI can potentially be applied for evaluation of prostatic diseases in which the extent of luminal space differs between normal and abnormal tissues. 1 Technical Efficacy: Stage 1 J. MAGN. RESON. IMAGING 2017;46:861-869. © 2017 International Society for Magnetic Resonance in Medicine.

  20. Using quantitative breath sound measurements to predict lung function following resection

    Directory of Open Access Journals (Sweden)

    Keus Leendert


    Full Text Available Abstract Background Predicting postoperative lung function is important for estimating the risk of complications and long-term disability after pulmonary resection. We investigated the capability of vibration response imaging (VRI as an alternative to lung scintigraphy for prediction of postoperative lung function in patients with intrathoracic malignancies. Methods Eighty-five patients with intrathoracic malignancies, considered candidates for lung resection, were prospectively studied. The projected postoperative (ppo lung function was calculated using: perfusion scintigraphy, ventilation scintigraphy, and VRI. Two sets of assessments made: one for lobectomy and one for pneumonectomy. Clinical concordance was defined as both methods agreeing that either a patient was or was not a surgical candidate based on a ppoFEV1% and ppoDLCO% > 40%. Results Limits of agreement between scintigraphy and VRI for ppo following lobectomy were -16.47% to 15.08% (mean difference = -0.70%;95%CI = -2.51% to 1.12% and for pneumonectomy were -23.79% to 19.04% (mean difference = -2.38%;95%CI = -4.69% to -0.07%. Clinical concordance between VRI and scintigraphy was 73% for pneumonectomy and 98% for lobectomy. For patients who had surgery and postoperative lung function testing (n = 31, ppoFEV1% using scintigraphic methods correlated with measured postoperative values better than projections using VRI, (adjusted R2 = 0.32 scintigraphy; 0.20 VRI, however the difference between methods failed to reach statistical significance. Limits of agreement between measured FEV1% postoperatively and ppoFEV1% based on perfusion scintigraphy were -16.86% to 23.73% (mean difference = 3.44%;95%CI = -0.29% to 7.16%; based on VRI were -19.56% to 28.99% (mean difference = 4.72%;95%CI = 0.27% to 9.17%. Conclusions Further investigation of VRI as an alternative to lung scintigraphy for prediction of postoperative lung function is warranted.

  1. Combined heart rate variability and dynamic measures for quantitatively characterizing the cardiac stress status during cycling exercise. (United States)

    Chen, Szi-Wen; Liaw, Jiunn-Woei; Chang, Ya-Ju; Chuang, Li-Ling; Chien, Chun-Tse


    In this study, we aimed to seek for different ways of measuring cardiac stress in t