WorldWideScience

Sample records for centroid finding method

  1. Centroid finding method for position-sensitive detectors

    International Nuclear Information System (INIS)

    Radeka, V.; Boie, R.A.

    1979-10-01

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips of wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N/sup 3/2/, where N is the number of subdivisions

  2. Centroid finding method for position-sensitive detectors

    International Nuclear Information System (INIS)

    Radeka, V.; Boie, R.A.

    1980-01-01

    A new centroid finding method for all detectors where the signal charge is collected or induced on strips or wires, or on subdivided resistive electrodes, is presented. The centroid of charge is determined by convolution of the sequentially switched outputs from these subdivisions or from the strips with a linear centroid finding filter. The position line width is inversely proportional to N 3 sup(/) 2 , where N is the number of subdivisions. (orig.)

  3. Modification of backgammon shape cathode and graded charge division readout method for a novel triple charge division centroid finding method

    International Nuclear Information System (INIS)

    Javanmardi, F.; Matoba, M.; Sakae, T.

    1996-01-01

    Triple Charge Division (TCD) centroid finding method that uses modified pattern of Backgammon Shape Cathode (MBSC) is introduced for medium range length position sensitive detectors with optimum numbers of cathode segments. MBSC pattern has three separated areas and uses saw tooth like insulator gaps for separating the areas. Side areas of the MBSC pattern are severed by a central common area. Size of the central area is twice of the size of both sides. Whereas central area is the widest area among three, both sides' areas have the main role in position sensing. With the same resolution and linearity, active region of original Backgammon pattern increases twice by using MBSC pattern, and with the same length, linearity of TCD centroid finding is much better than Backgammon charge division readout method. Linearity prediction of TCD centroid finding and experimental results conducted us to find an optimum truncation of the apices of MBCS pattern in the central area. The TCD centroid finding has an especial readout method since charges must be collected from two segments in both sides and from three segments in the central area of MBSC pattern. The so called Graded Charge Division (GCD) is the especial readout method for TCD. The GCD readout is a combination of the charge division readout and sequence grading of serial segments. Position sensing with TCD centroid finding and GCD readout were done by two sizes MBSC patterns (200mm and 80mm) and Spatial resolution about 1% of the detector length is achieved

  4. Implementation of the Centroid Method for the Correction of Turbulence

    Directory of Open Access Journals (Sweden)

    Enric Meinhardt-Llopis

    2014-07-01

    Full Text Available The centroid method for the correction of turbulence consists in computing the Karcher-Fréchet mean of the sequence of input images. The direction of deformation between a pair of images is determined by the optical flow. A distinguishing feature of the centroid method is that it can produce useful results from an arbitrarily small set of input images.

  5. Centroid crossing

    International Nuclear Information System (INIS)

    Swift, G.

    1990-01-01

    This paper presents an algorithm for finding peaks in data spectra. It is based on calculating a moving centroid across the spectrum and picking off the points between which the calculated centroid crosses the channel number. Interpolation can then yield a more precise peak location. This algorithm can be implemented very efficiently requiring about one addition, subtraction, multiplication, and division operation per data point. With integer data and a centroid window equal to a power of two (so that the division can be done with shifts), the algorithm is particularly suited to efficient machine language implementation. With suitable adjustments (involving only little overhead except at suspected peaks), it is possible to minimize either false peak location or missing good peaks. Extending the method to more dimensions is straightforward although interpolating is more difficult. The algorithm has been used on a variety of nuclear data spectra with great success

  6. Multiple centroid method to evaluate the adaptability of alfalfa genotypes

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2015-02-01

    Full Text Available This study aimed to evaluate the efficiency of multiple centroids to study the adaptability of alfalfa genotypes (Medicago sativa L.. In this method, the genotypes are compared with ideotypes defined by the bissegmented regression model, according to the researcher's interest. Thus, genotype classification is carried out as determined by the objective of the researcher and the proposed recommendation strategy. Despite the great potential of the method, it needs to be evaluated under the biological context (with real data. In this context, we used data on the evaluation of dry matter production of 92 alfalfa cultivars, with 20 cuttings, from an experiment in randomized blocks with two repetitions carried out from November 2004 to June 2006. The multiple centroid method proved efficient for classifying alfalfa genotypes. Moreover, it showed no unambiguous indications and provided that ideotypes were defined according to the researcher's interest, facilitating data interpretation.

  7. Diffeomorphic Iterative Centroid Methods for Template Estimation on Large Datasets

    OpenAIRE

    Cury , Claire; Glaunès , Joan Alexis; Colliot , Olivier

    2014-01-01

    International audience; A common approach for analysis of anatomical variability relies on the stimation of a template representative of the population. The Large Deformation Diffeomorphic Metric Mapping is an attractive framework for that purpose. However, template estimation using LDDMM is computationally expensive, which is a limitation for the study of large datasets. This paper presents an iterative method which quickly provides a centroid of the population in the shape space. This centr...

  8. A physics-motivated Centroidal Voronoi Particle domain decomposition method

    Energy Technology Data Exchange (ETDEWEB)

    Fu, Lin, E-mail: lin.fu@tum.de; Hu, Xiangyu Y., E-mail: xiangyu.hu@tum.de; Adams, Nikolaus A., E-mail: nikolaus.adams@tum.de

    2017-04-15

    In this paper, we propose a novel domain decomposition method for large-scale simulations in continuum mechanics by merging the concepts of Centroidal Voronoi Tessellation (CVT) and Voronoi Particle dynamics (VP). The CVT is introduced to achieve a high-level compactness of the partitioning subdomains by the Lloyd algorithm which monotonically decreases the CVT energy. The number of computational elements between neighboring partitioning subdomains, which scales the communication effort for parallel simulations, is optimized implicitly as the generated partitioning subdomains are convex and simply connected with small aspect-ratios. Moreover, Voronoi Particle dynamics employing physical analogy with a tailored equation of state is developed, which relaxes the particle system towards the target partition with good load balance. Since the equilibrium is computed by an iterative approach, the partitioning subdomains exhibit locality and the incremental property. Numerical experiments reveal that the proposed Centroidal Voronoi Particle (CVP) based algorithm produces high-quality partitioning with high efficiency, independently of computational-element types. Thus it can be used for a wide range of applications in computational science and engineering.

  9. A further investigation of the centroid-to-centroid method for stereotactic lung radiotherapy: A phantom study

    International Nuclear Information System (INIS)

    Lu, Bo; Samant, Sanjiv; Mittauer, Kathryn; Lee, Soyoung; Huang, Yin; Li, Jonathan; Kahler, Darren; Liu, Chihray

    2013-01-01

    Purpose: Our previous study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] proposed a deformable-registration-based patient setup strategy called the centroid-to-centroid (CTC) method, which can perform an accurate alignment of internal-target-volume (ITV) centroids between averaged four-dimensional computed tomography and cone-beam computed tomography (CBCT) images. Scenarios with variations between CBCT and simulation CT caused by irregular breathing and/or tumor change were not specifically considered in the patient study [B. Lu et al., “A patient alignment solution for lung SBRT setups based on a deformable registration technique,” Med. Phys. 39(12), 7379–7389 (2012)] due to the lack of both a sufficiently large patient data sample and a method of tumor tracking. The aim of this study is to thoroughly investigate and compare the impacts of breathing pattern and tumor change on both the CTC and the translation-only (T-only) gray-value mode strategies by employing a four-dimensional (4D) lung phantom.Methods: A sophisticated anthropomorphic 4D phantom (CIRS Dynamic Thorax Phantom model 008) was employed to simulate all desired respiratory variations. The variation scenarios were classified into four groups: inspiration to expiration ratio (IE ratio) change, tumor trajectory change, tumor position change, tumor size change, and the combination of these changes. For each category the authors designed several scenarios to demonstrate the effects of different levels of breathing variation on both of the T-only and the CTC methods. Each scenario utilized 4DCT and CBCT scans. The ITV centroid alignment discrepancies for CTC and T-only were evaluated. The dose-volume-histograms (DVHs) of ITVs for two extreme cases were analyzed.Results: Except for some extreme cases in the combined group, the accuracy of the CTC registration was about 2 mm for all cases for

  10. Comparison of performance of some common Hartmann-Shack centroid estimation methods

    Science.gov (United States)

    Thatiparthi, C.; Ommani, A.; Burman, R.; Thapa, D.; Hutchings, N.; Lakshminarayanan, V.

    2016-03-01

    The accuracy of the estimation of optical aberrations by measuring the distorted wave front using a Hartmann-Shack wave front sensor (HSWS) is mainly dependent upon the measurement accuracy of the centroid of the focal spot. The most commonly used methods for centroid estimation such as the brightest spot centroid; first moment centroid; weighted center of gravity and intensity weighted center of gravity, are generally applied on the entire individual sub-apertures of the lens let array. However, these processes of centroid estimation are sensitive to the influence of reflections, scattered light, and noise; especially in the case where the signal spot area is smaller compared to the whole sub-aperture area. In this paper, we give a comparison of performance of the commonly used centroiding methods on estimation of optical aberrations, with and without the use of some pre-processing steps (thresholding, Gaussian smoothing and adaptive windowing). As an example we use the aberrations of the human eye model. This is done using the raw data collected from a custom made ophthalmic aberrometer and a model eye to emulate myopic and hyper-metropic defocus values up to 2 Diopters. We show that the use of any simple centroiding algorithm is sufficient in the case of ophthalmic applications for estimating aberrations within the typical clinically acceptable limits of a quarter Diopter margins, when certain pre-processing steps to reduce the impact of external factors are used.

  11. The efficiency of the centroid method compared to a simple average

    DEFF Research Database (Denmark)

    Eskildsen, Jacob Kjær; Kristensen, Kai; Nielsen, Rikke

    Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot.......Based on empirical data as well as a simulation study this paper gives recommendations with respect to situations wheere a simple avarage of the manifest indicators can be used as a close proxy for the centroid method and when it cannot....

  12. Statistical analysis of x-ray stress measurement by centroid method

    International Nuclear Information System (INIS)

    Kurita, Masanori; Amano, Jun; Sakamoto, Isao

    1982-01-01

    The X-ray technique allows a nondestructive and rapid measurement of residual stresses in metallic materials. The centroid method has an advantage over other X-ray methods in that it can determine the angular position of a diffraction line, from which the stress is calculated, even with an asymmetrical line profile. An equation for the standard deviation of the angular position of a diffraction line, σsub(p), caused by statistical fluctuation was derived, which is a fundamental source of scatter in X-ray stress measurements. This equation shows that an increase of X-ray counts by a factor of k results in a decrease of σsub(p) by a factor of 1/√k. It also shows that σsub(p) increases rapidly as the angular range used in calculating the centroid increases. It is therefore important to calculate the centroid using the narrow angular range between the two ends of the diffraction line where it starts to deviate from the straight background line. By using quenched structural steels JIS S35C and S45C, the residual stresses and their standard deviations were calculated by the centroid, parabola, Gaussian curve, and half-width methods, and the results were compared. The centroid of a diffraction line was affected greatly by the background line used. The standard deviation of the stress measured by the centroid method was found to be the largest among the four methods. (author)

  13. Fast centroid algorithm for determining the surface plasmon resonance angle using the fixed-boundary method

    International Nuclear Information System (INIS)

    Zhan, Shuyue; Wang, Xiaoping; Liu, Yuling

    2011-01-01

    To simplify the algorithm for determining the surface plasmon resonance (SPR) angle for special applications and development trends, a fast method for determining an SPR angle, called the fixed-boundary centroid algorithm, has been proposed. Two experiments were conducted to compare three centroid algorithms from the aspects of the operation time, sensitivity to shot noise, signal-to-noise ratio (SNR), resolution, and measurement range. Although the measurement range of this method was narrower, the other performance indices were all better than the other two centroid methods. This method has outstanding performance, high speed, good conformity, low error and a high SNR and resolution. It thus has the potential to be widely adopted

  14. Differential computation method used to calibrate the angle-centroid relationship in coaxial reverse Hartmann test

    Science.gov (United States)

    Li, Xinji; Hui, Mei; Zhao, Zhu; Liu, Ming; Dong, Liquan; Kong, Lingqin; Zhao, Yuejin

    2018-05-01

    A differential computation method is presented to improve the precision of calibration for coaxial reverse Hartmann test (RHT). In the calibration, the accuracy of the distance measurement greatly influences the surface shape test, as demonstrated in the mathematical analyses. However, high-precision absolute distance measurement is difficult in the calibration. Thus, a differential computation method that only requires the relative distance was developed. In the proposed method, a liquid crystal display screen successively displayed two regular dot matrix patterns with different dot spacing. In a special case, images on the detector exhibited similar centroid distributions during the reflector translation. Thus, the critical value of the relative displacement distance and the centroid distributions of the dots on the detector were utilized to establish the relationship between the rays at certain angles and the detector coordinates. Experiments revealed the approximately linear behavior of the centroid variation with the relative displacement distance. With the differential computation method, we increased the precision of traditional calibration 10-5 rad root mean square. The precision of the RHT was increased by approximately 100 nm.

  15. Noninvasive measurement of cardiopulmonary blood volume: evaluation of the centroid method

    International Nuclear Information System (INIS)

    Fouad, F.M.; MacIntyre, W.J.; Tarazi, R.C.

    1981-01-01

    Cardiopulmonary blood volume (CPV) and mean pulmonary transit time (MTT) determined by radionuclide measurements (Tc-99m HSA) were compared with values obtained from simultaneous dye-dilution (DD) studies (indocyanine green). The mean transit time was obtained from radionuclide curves by two methods: the peak-to-peak time and the interval between the two centroids determined from the right and left-ventricular time-concentration curves. Correlation of dye-dilution MTT and peak-to-peak time was significant (r = 0.79, p < 0.001), but its correlation with centroid-derived values was better (r = 0.86, p < 0.001). CPV values (using the centroid method for radionuclide technique) correlated significantly with values derived from dye-dilution curves (r = 0.74, p < 0.001). Discrepancies between the two were greater the more rapid the circulation (r = 0.61, p < 0.01), suggesting that minor inaccuracies of dye-dilution methods, due to positioning or delay of the system, can become magnified in hyperkinetic conditions. The radionuclide method is simple, repeatable, and noninvasive, and it provides simultaneous evaluation of pulmonary and systemic hemodynamics. Further, calculation of the ratio of cardiopulmonary to total blood volume can be used as an index of overall venous distensibility and relocation of intravascular blood volume

  16. Performance Evaluation of the Spectral Centroid Downshift Method for Attenuation Estimation

    OpenAIRE

    Samimi, Kayvan; Varghese, Tomy

    2015-01-01

    Estimation of frequency-dependent ultrasonic attenuation is an important aspect of tissue characterization. Along with other acoustic parameters studied in quantitative ultrasound, the attenuation coefficient can be used to differentiate normal and pathological tissue. The spectral centroid downshift (CDS) method is one the most common frequency-domain approaches applied to this problem. In this study, a statistical analysis of this method’s performance was carried out based on a parametric m...

  17. Improvement of correlation-based centroiding methods for point source Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Li, Xuxu; Li, Xinyang; wang, Caixia

    2018-03-01

    This paper proposes an efficient approach to decrease the computational costs of correlation-based centroiding methods used for point source Shack-Hartmann wavefront sensors. Four typical similarity functions have been compared, i.e. the absolute difference function (ADF), ADF square (ADF2), square difference function (SDF), and cross-correlation function (CCF) using the Gaussian spot model. By combining them with fast search algorithms, such as three-step search (TSS), two-dimensional logarithmic search (TDL), cross search (CS), and orthogonal search (OS), computational costs can be reduced drastically without affecting the accuracy of centroid detection. Specifically, OS reduces calculation consumption by 90%. A comprehensive simulation indicates that CCF exhibits a better performance than other functions under various light-level conditions. Besides, the effectiveness of fast search algorithms has been verified.

  18. Adaptive thresholding and dynamic windowing method for automatic centroid detection of digital Shack-Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin Xiaoming; Li Xiang; Zhao Liping; Fang Zhongping

    2009-01-01

    A Shack-Hartmann wavefront sensor (SWHS) splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. The accuracy of the centroid measurement determines the accuracy of the SWHS. Many methods have been presented to improve the accuracy of the wavefront centroid measurement. However, most of these methods are discussed from the point of view of optics, based on the assumption that the spot intensity of the SHWS has a Gaussian distribution, which is not applicable to the digital SHWS. In this paper, we present a centroid measurement algorithm based on the adaptive thresholding and dynamic windowing method by utilizing image processing techniques for practical application of the digital SHWS in surface profile measurement. The method can detect the centroid of each focal spot precisely and robustly by eliminating the influence of various noises, such as diffraction of the digital SHWS, unevenness and instability of the light source, as well as deviation between the centroid of the focal spot and the center of the detection area. The experimental results demonstrate that the algorithm has better precision, repeatability, and stability compared with other commonly used centroid methods, such as the statistical averaging, thresholding, and windowing algorithms.

  19. Performance Analysis of Combined Methods of Genetic Algorithm and K-Means Clustering in Determining the Value of Centroid

    Science.gov (United States)

    Adya Zizwan, Putra; Zarlis, Muhammad; Budhiarti Nababan, Erna

    2017-12-01

    The determination of Centroid on K-Means Algorithm directly affects the quality of the clustering results. Determination of centroid by using random numbers has many weaknesses. The GenClust algorithm that combines the use of Genetic Algorithms and K-Means uses a genetic algorithm to determine the centroid of each cluster. The use of the GenClust algorithm uses 50% chromosomes obtained through deterministic calculations and 50% is obtained from the generation of random numbers. This study will modify the use of the GenClust algorithm in which the chromosomes used are 100% obtained through deterministic calculations. The results of this study resulted in performance comparisons expressed in Mean Square Error influenced by centroid determination on K-Means method by using GenClust method, modified GenClust method and also classic K-Means.

  20. Performance evaluation of the spectral centroid downshift method for attenuation estimation.

    Science.gov (United States)

    Samimi, Kayvan; Varghese, Tomy

    2015-05-01

    Estimation of frequency-dependent ultrasonic attenuation is an important aspect of tissue characterization. Along with other acoustic parameters studied in quantitative ultrasound, the attenuation coefficient can be used to differentiate normal and pathological tissue. The spectral centroid downshift (CDS) method is one the most common frequencydomain approaches applied to this problem. In this study, a statistical analysis of this method's performance was carried out based on a parametric model of the signal power spectrum in the presence of electronic noise. The parametric model used for the power spectrum of received RF data assumes a Gaussian spectral profile for the transmit pulse, and incorporates effects of attenuation, windowing, and electronic noise. Spectral moments were calculated and used to estimate second-order centroid statistics. A theoretical expression for the variance of a maximum likelihood estimator of attenuation coefficient was derived in terms of the centroid statistics and other model parameters, such as transmit pulse center frequency and bandwidth, RF data window length, SNR, and number of regression points. Theoretically predicted estimation variances were compared with experimentally estimated variances on RF data sets from both computer-simulated and physical tissue-mimicking phantoms. Scan parameter ranges for this study were electronic SNR from 10 to 70 dB, transmit pulse standard deviation from 0.5 to 4.1 MHz, transmit pulse center frequency from 2 to 8 MHz, and data window length from 3 to 17 mm. Acceptable agreement was observed between theoretical predictions and experimentally estimated values with differences smaller than 0.05 dB/cm/MHz across the parameter ranges investigated. This model helps predict the best attenuation estimation variance achievable with the CDS method, in terms of said scan parameters.

  1. Lifetime measurements in {sup 170}Yb using the generalized centroid difference method

    Energy Technology Data Exchange (ETDEWEB)

    Karayonchev, Vasil; Regis, Jean-Marc; Jolie, Jan; Dannhoff, Moritz; Saed-Samii, Nima; Blazhev, Andrey [Institute of Nuclear Physics, University of Cologne, Cologne (Germany)

    2016-07-01

    An experiment using the electronic γ-γ ''fast-timing'' technique was performed at the 10 MV Tandem Van-De-Graaff accelerator of the Institute for Nuclear Physics, Cologne in order to measure lifetimes of the yrast states in {sup 170}Yb. The lifetime of the first 2{sup +} state was determined using the slope method, which means by fitting an exponential decay to the ''slope'' seen in the energy-gated time-difference spectra. The value of τ=2.201(57) ns is in good agreement with the lifetimes measured using other techniques. The lifetimes of the first 4{sup +} and the 6{sup +} states are determined for the first time. They are in the ps range and were measured using the generalized centroid difference method, an extension of the well-known centroid-shift method and developed for fast-timing arrays. The derived reduced transition probabilities B(E2) values are compared with calculations done using the confined beta soft model and show good agreement within the experimental uncertainties.

  2. Shack-Hartmann centroid detection method based on high dynamic range imaging and normalization techniques

    International Nuclear Information System (INIS)

    Vargas, Javier; Gonzalez-Fernandez, Luis; Quiroga, Juan Antonio; Belenguer, Tomas

    2010-01-01

    In the optical quality measuring process of an optical system, including diamond-turning components, the use of a laser light source can produce an undesirable speckle effect in a Shack-Hartmann (SH) CCD sensor. This speckle noise can deteriorate the precision and accuracy of the wavefront sensor measurement. Here we present a SH centroid detection method founded on computer-based techniques and capable of measurement in the presence of strong speckle noise. The method extends the dynamic range imaging capabilities of the SH sensor through the use of a set of different CCD integration times. The resultant extended range spot map is normalized to accurately obtain the spot centroids. The proposed method has been applied to measure the optical quality of the main optical system (MOS) of the mid-infrared instrument telescope smulator. The wavefront at the exit of this optical system is affected by speckle noise when it is illuminated by a laser source and by air turbulence because it has a long back focal length (3017 mm). Using the proposed technique, the MOS wavefront error was measured and satisfactory results were obtained.

  3. Ranking Fuzzy Numbers with a Distance Method using Circumcenter of Centroids and an Index of Modality

    Directory of Open Access Journals (Sweden)

    P. Phani Bushan Rao

    2011-01-01

    Full Text Available Ranking fuzzy numbers are an important aspect of decision making in a fuzzy environment. Since their inception in 1965, many authors have proposed different methods for ranking fuzzy numbers. However, there is no method which gives a satisfactory result to all situations. Most of the methods proposed so far are nondiscriminating and counterintuitive. This paper proposes a new method for ranking fuzzy numbers based on the Circumcenter of Centroids and uses an index of optimism to reflect the decision maker's optimistic attitude and also an index of modality that represents the neutrality of the decision maker. This method ranks various types of fuzzy numbers which include normal, generalized trapezoidal, and triangular fuzzy numbers along with crisp numbers with the particularity that crisp numbers are to be considered particular cases of fuzzy numbers.

  4. An improved Q estimation approach: the weighted centroid frequency shift method

    Science.gov (United States)

    Li, Jingnan; Wang, Shangxu; Yang, Dengfeng; Dong, Chunhui; Tao, Yonghui; Zhou, Yatao

    2016-06-01

    Seismic wave propagation in subsurface media suffers from absorption, which can be quantified by the quality factor Q. Accurate estimation of the Q factor is of great importance for the resolution enhancement of seismic data, precise imaging and interpretation, and reservoir prediction and characterization. The centroid frequency shift method (CFS) is currently one of the most commonly used Q estimation methods. However, for seismic data that contain noise, the accuracy and stability of Q extracted using CFS depend on the choice of frequency band. In order to reduce the influence of frequency band choices and obtain Q with greater precision and robustness, we present an improved CFS Q measurement approach—the weighted CFS method (WCFS), which incorporates a Gaussian weighting coefficient into the calculation procedure of the conventional CFS. The basic idea is to enhance the proportion of advantageous frequencies in the amplitude spectrum and reduce the weight of disadvantageous frequencies. In this novel method, we first construct a Gauss function using the centroid frequency and variance of the reference wavelet. Then we employ it as the weighting coefficient for the amplitude spectrum of the original signal. Finally, the conventional CFS is adopted for the weighted amplitude spectrum to extract the Q factor. Numerical tests of noise-free synthetic data demonstrate that the WCFS is feasible and efficient, and produces more accurate results than the conventional CFS. Tests for noisy synthetic data indicate that the new method has better anti-noise capability than the CFS. The application to field vertical seismic profile (VSP) data further demonstrates its validity5.

  5. A walk-free centroid method for lifetime measutement of 207Pb 569.7 keV state

    International Nuclear Information System (INIS)

    Gu Jiahui; Liu Jingyi; Xiao Genlai

    1988-01-01

    An improvement have been made in acquiring data of delayed coincidence spectra with ND-620 data acquisition system and off-line data analysis program. The delayed and anti-delayed coincidence spectra can be obtained in one run. The difference of their centroids is the mean lifetime τ. The centroid position of a delayed coincidence spectrum is the zero time of another delayed coincidence spectrum, so the requirement of measuring prompt time spectrum is avoided. The walk of prompt and delayed coincidence spectrum coming from different run are resolved and the walk during the measurement is compensated partly. The delayed coincidence time spectra of 207 Pb 569.7 keV state are measured and the half lifetime is calculated via three different methods (slop method, convolution method, centroid shift). The final value of half lifetime is 129.5±1.4ps. THe experimental reduced transition probability is compared with theoretical values

  6. Two tree-formation methods for fast pattern search using nearest-neighbour and nearest-centroid matching

    NARCIS (Netherlands)

    Schomaker, Lambertus; Mangalagiu, D.; Vuurpijl, Louis; Weinfeld, M.; Schomaker, Lambert; Vuurpijl, Louis

    2000-01-01

    This paper describes tree­based classification of character images, comparing two methods of tree formation and two methods of matching: nearest neighbor and nearest centroid. The first method, Preprocess Using Relative Distances (PURD) is a tree­based reorganization of a flat list of patterns,

  7. Comparison of pure and 'Latinized' centroidal Voronoi tessellation against various other statistical sampling methods

    International Nuclear Information System (INIS)

    Romero, Vicente J.; Burkardt, John V.; Gunzburger, Max D.; Peterson, Janet S.

    2006-01-01

    A recently developed centroidal Voronoi tessellation (CVT) sampling method is investigated here to assess its suitability for use in statistical sampling applications. CVT efficiently generates a highly uniform distribution of sample points over arbitrarily shaped M-dimensional parameter spaces. On several 2-D test problems CVT has recently been found to provide exceedingly effective and efficient point distributions for response surface generation. Additionally, for statistical function integration and estimation of response statistics associated with uniformly distributed random-variable inputs (uncorrelated), CVT has been found in initial investigations to provide superior points sets when compared against latin-hypercube and simple-random Monte Carlo methods and Halton and Hammersley quasi-random sequence methods. In this paper, the performance of all these sampling methods and a new variant ('Latinized' CVT) are further compared for non-uniform input distributions. Specifically, given uncorrelated normal inputs in a 2-D test problem, statistical sampling efficiencies are compared for resolving various statistics of response: mean, variance, and exceedence probabilities

  8. K-Means Algorithm Performance Analysis With Determining The Value Of Starting Centroid With Random And KD-Tree Method

    Science.gov (United States)

    Sirait, Kamson; Tulus; Budhiarti Nababan, Erna

    2017-12-01

    Clustering methods that have high accuracy and time efficiency are necessary for the filtering process. One method that has been known and applied in clustering is K-Means Clustering. In its application, the determination of the begining value of the cluster center greatly affects the results of the K-Means algorithm. This research discusses the results of K-Means Clustering with starting centroid determination with a random and KD-Tree method. The initial determination of random centroid on the data set of 1000 student academic data to classify the potentially dropout has a sse value of 952972 for the quality variable and 232.48 for the GPA, whereas the initial centroid determination by KD-Tree has a sse value of 504302 for the quality variable and 214,37 for the GPA variable. The smaller sse values indicate that the result of K-Means Clustering with initial KD-Tree centroid selection have better accuracy than K-Means Clustering method with random initial centorid selection.

  9. A walk-free centroid method for lifetime measurements with pulsed beams

    International Nuclear Information System (INIS)

    Julin, R.; Kantele, J.; Luontama, M.; Passoja, A.; Poikolainen, T.

    1977-09-01

    A delayed-coincidence lifetime measurement method based on a comparison of walk-free centroids of time spectra is presented. The time is measured between the cyclotron RF signal and the pulse from a plastic scintillation detector followed by a fixed energy selection. The events to be time-analyzed are selected from the associated charge-particle spectrum of a silicon detector which is operated in coincidence with the scintillator, i.e., independently of the formation of the signal containing the time information. With this technique, with the micropulse FWHM of typically 500 to 700 ps, half-lives down to the 10 ps region can be measured. The following half-lives are obtained with the new method: 160+-6 ps for the 2032 keV level in 209 Pb; 45+-10 ps and 160+-20 ps for the 1756.8 keV (0 2 + ) and 2027.3 keV (0 3 + ) levels in 116 Sn, respectively. (author)

  10. Centroid and full-width at half maximum uncertainties of histogrammed data with an underlying Gaussian distribution -- The moments method

    International Nuclear Information System (INIS)

    Valentine, J.D.; Rana, A.E.

    1996-01-01

    The effect of approximating a continuous Gaussian distribution with histogrammed data are studied. The expressions for theoretical uncertainties in centroid and full-width at half maximum (FWHM), as determined by calculation of moments, are derived using the error propagation method for a histogrammed Gaussian distribution. The results are compared with the corresponding pseudo-experimental uncertainties for computer-generated histogrammed Gaussian peaks to demonstrate the effect of binning the data. It is shown that increasing the number of bins in the histogram improves the continuous distribution approximation. For example, a FWHM ≥ 9 and FWHM ≥ 12 bins are needed to reduce the pseudo-experimental standard deviation of FWHM to within ≥5% and ≥1%, respectively, of the theoretical value for a peak containing 10,000 counts. In addition, the uncertainties in the centroid and FWHM as a function of peak area are studied. Finally, Sheppard's correction is applied to partially correct for the binning effect

  11. Centroid Localization of Uncooperative Nodes in Wireless Networks Using a Relative Span Weighting Method

    Directory of Open Access Journals (Sweden)

    Christine Laurendeau

    2010-01-01

    Full Text Available Increasingly ubiquitous wireless technologies require novel localization techniques to pinpoint the position of an uncooperative node, whether the target is a malicious device engaging in a security exploit or a low-battery handset in the middle of a critical emergency. Such scenarios necessitate that a radio signal source be localized by other network nodes efficiently, using minimal information. We propose two new algorithms for estimating the position of an uncooperative transmitter, based on the received signal strength (RSS of a single target message at a set of receivers whose coordinates are known. As an extension to the concept of centroid localization, our mechanisms weigh each receiver's coordinates based on the message's relative RSS at that receiver, with respect to the span of RSS values over all receivers. The weights may decrease from the highest RSS receiver either linearly or exponentially. Our simulation results demonstrate that for all but the most sparsely populated wireless networks, our exponentially weighted mechanism localizes a target node within the regulations stipulated for emergency services location accuracy.

  12. The mirror symmetric centroid difference method for picosecond lifetime measurements via {gamma}-{gamma} coincidences using very fast LaBr{sub 3}(Ce) scintillator detectors

    Energy Technology Data Exchange (ETDEWEB)

    Regis, J.-M., E-mail: regis@ikp.uni-koeln.d [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany); Pascovici, G.; Jolie, J.; Rudigier, M. [Institut fuer Kernphysik, Universitaet zu Koeln, Zuelpicher Str. 77, 50937 Koeln (Germany)

    2010-10-01

    The ultra-fast timing technique was introduced in the 1980s and is capable of measuring picosecond lifetimes of nuclear excited states with about 3 ps accuracy. Very fast scintillator detectors are connected to an electronic timing circuit and detector vs. detector time spectra are analyzed by means of the centroid shift method. The very good 3% energy resolution of the nowadays available LaBr{sub 3}(Ce) scintillator detectors for {gamma}-rays has made possible an extension of the well-established fast timing technique. The energy dependent fast timing characteristics or the prompt curve, respectively, of the LaBr{sub 3}(Ce) scintillator detector has been measured using a standard {sup 152}Eu {gamma}-ray source. For any energy combination in the range of 200keVcentroid shift method providing very attractive features for picosecond lifetime measurements is presented. The mirror symmetric centroid difference method takes advantage of the symmetry obtained when performing {gamma}-{gamma} lifetime measurements using a pair of almost identical very fast scintillator detectors. In particular cases, the use of the mirror symmetric centroid difference method also allows the direct determination of picosecond lifetimes, hence without the need of calibrating the prompt curve.

  13. Alteração no método centroide de avaliação da adaptabilidade genotípica Alteration of the centroid method to evaluate genotypic adaptability

    Directory of Open Access Journals (Sweden)

    Moysés Nascimento

    2009-03-01

    Full Text Available O objetivo deste trabalho foi alterar o método centroide de avaliação da adaptabilidade e estabilidade fenotípica de genótipos, para deixá-lo com maior sentido biológico e melhorar aspectos quantitativos e qualitativos de sua análise. A alteração se deu pela adição de mais três ideótipos, definidos de acordo com valores médios dos genótipos nos ambientes. Foram utilizados dados provenientes de um experimento sobre produção de matéria seca de 92 genótipos de alfafa (Medicago sativa realizado em blocos ao acaso, com duas repetições. Os genótipos foram submetidos a 20 cortes, no período de novembro de 2004 a junho de 2006. Cada corte foi considerado um ambiente. A inclusão dos ideótipos de maior sentido biológico (valores médios nos ambientes resultou em uma dispersão gráfica em forma de uma seta voltada para a direita, na qual os genótipos mais produtivos ficaram próximos à ponta da seta. Com a alteração, apenas cinco genótipos foram classificados nas mesmas classes do método centroide original. A figura em forma de seta proporciona uma comparação direta dos genótipos, por meio da formação de um gradiente de produtividade. A alteração no método mantém a facilidade de interpretação dos resultados para a recomendação dos genótipos presente no método original e não permite duplicidade de interpretação dos resultados.ABSTRACT The objective of this work was to modify the centroid method of evaluation of phenotypic adaptability and the phenotype stability of genotypes in order for the method to make greater biological sense and improve its quantitative and qualitative performance. The method was modified by means of the inclusion of three additional ideotypes defined in accordance with the genotypes' average yield in the environments tested. The alfalfa (Medicago sativa L. forage yield of 92 genotypes was used. The trial had a randomized block design, with two replicates, and the data were used to

  14. Depth to the bottom of magnetic sources (DBMS) from aeromagnetic data of Central India using modified centroid method for fractal distribution of sources

    Science.gov (United States)

    Bansal, A. R.; Anand, S. P.; Rajaram, Mita; Rao, V. K.; Dimri, V. P.

    2013-09-01

    The depth to the bottom of the magnetic sources (DBMS) has been estimated from the aeromagnetic data of Central India. The conventional centroid method of DBMS estimation assumes random uniform uncorrelated distribution of sources and to overcome this limitation a modified centroid method based on scaling distribution has been proposed. Shallower values of the DBMS are found for the south western region. The DBMS values are found as low as 22 km in the south west Deccan trap covered regions and as deep as 43 km in the Chhattisgarh Basin. In most of the places DBMS are much shallower than the Moho depth, earlier found from the seismic study and may be representing the thermal/compositional/petrological boundaries. The large variation in the DBMS indicates the complex nature of the Indian crust.

  15. A Reference Point Construction Method Using Mobile Terminals and the Indoor Localization Evaluation in the Centroid Method

    Directory of Open Access Journals (Sweden)

    Takahiro Yamaguchi

    2015-05-01

    Full Text Available As smartphones become widespread, a variety of smartphone applications are being developed. This paper proposes a method for indoor localization (i.e., positioning that uses only smartphones, which are general-purpose mobile terminals, as reference point devices. This method has the following features: (a the localization system is built with smartphones whose movements are confined to respective limited areas. No fixed reference point devices are used; (b the method does not depend on the wireless performance of smartphones and does not require information about the propagation characteristics of the radio waves sent from reference point devices, and (c the method determines the location at the application layer, at which location information can be easily incorporated into high-level services. We have evaluated the level of localization accuracy of the proposed method by building a software emulator that modeled an underground shopping mall. We have confirmed that the determined location is within a small area in which the user can find target objects visually.

  16. A Hybridized Centroid Technique for 3D Molodensky-Badekas ...

    African Journals Online (AJOL)

    Richannan

    the same point in a second reference frame (Ghilani, 2010). ... widely used approach by most researchers to compute values of centroid coordinates in the ... choice of centroid method on the Veis model has been investigated by Ziggah et al.

  17. Centroid motion in periodically focused beams

    International Nuclear Information System (INIS)

    Moraes, J.S.; Pakter, R.; Rizzato, F.B.

    2005-01-01

    The role of the centroid dynamics in the transport of periodically focused particle beams is investigated. A Kapchinskij-Vladimirskij equilibrium distribution for an off-axis beam is derived. It is shown that centroid and envelope dynamics are uncoupled and that unstable regions for the centroid dynamics overlap with previously stable regions for the envelope dynamics alone. Multiparticle simulations validate the findings. The effects of a conducting pipe encapsulating the beam are also investigated. It is shown that the charge induced at the pipe may generate chaotic orbits which can be detrimental to the adequate functioning of the transport mechanism

  18. Research on Centroid Position for Stairs Climbing Stability of Search and Rescue Robot

    Directory of Open Access Journals (Sweden)

    Yan Guo

    2011-01-01

    Full Text Available This paper represents the relationship between the stability of stairs climbing and the centroid position of the search and rescue robot. The robot system is considered as a mass point-plane model and the kinematics features are analyzed to find the relationship between centroid position and the maximal pitch angle of stairs the robot could climb up. A computable function about this relationship is given in this paper. During the stairs climbing, there is a maximal stability-keeping angle depends on the centroid position and the pitch angle of stairs, and the numerical formula is developed about the relationship between the maximal stability-keeping angle and the centroid position and pitch angle of stairs. The experiment demonstrates the trustworthy and correction of the method in the paper.

  19. The generalized centroid difference method for picosecond sensitive determination of lifetimes of nuclear excited states using large fast-timing arrays

    Energy Technology Data Exchange (ETDEWEB)

    Régis, J.-M., E-mail: regis@ikp.uni-koeln.de [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Mach, H. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Simpson, G.S. [Laboratoire de Physique Subatomique et de Cosmologie Grenoble, 53, rue des Martyrs, 38026 Grenoble Cedex (France); Jolie, J.; Pascovici, G.; Saed-Samii, N.; Warr, N. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Bruce, A. [School of Computing, Engineering and Mathematics, University of Brighton, Lewes Road, Brighton BN2 4GJ (United Kingdom); Degenkolb, J. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Fraile, L.M. [Departamento de Física Atómica y Nuclear, Universidad Complutense, 28040 Madrid (Spain); Fransen, C. [Institut für Kernphysik der Universität zu Köln, Zülpicher Str. 77, 50937 Köln (Germany); Ghita, D.G. [Horia Hulubei National Institute for Physics and Nuclear Engineering, 77125 Bucharest (Romania); and others

    2013-10-21

    A novel method for direct electronic “fast-timing” lifetime measurements of nuclear excited states via γ–γ coincidences using an array equipped with N∈N equally shaped very fast high-resolution LaBr{sub 3}(Ce) scintillator detectors is presented. Analogous to the mirror symmetric centroid difference method, the generalized centroid difference method provides two independent “start” and “stop” time spectra obtained by a superposition of the N(N−1)γ–γ time difference spectra of the N detector fast-timing system. The two fast-timing array time spectra correspond to a forward and reverse gating of a specific γ–γ cascade. Provided that the energy response and the electronic time pick-off of the detectors are almost equal, a mean prompt response difference between start and stop events is calibrated and used as a single correction for lifetime determination. These combined fast-timing arrays mean γ–γ time-walk characteristics can be determined for 40keVmethod over the total dynamic range is mainly determined by the statistics. The setup of an N=4 detector fast-timing array delivered an absolute time resolving power of 3 ps for 10 000 γ–γ events per total fast timing array start and stop time spectrum. The new method is tested over the total dynamic range by the measurements of known picosecond lifetimes in standard γ-ray sources.

  20. Noise in position measurement by centroid calculation

    International Nuclear Information System (INIS)

    Volkov, P.

    1996-01-01

    The position of a particle trajectory in a gaseous (or semiconductor) detector can be measured by calculating the centroid of the induced charge on the cathode plane. The charge amplifiers attached to each cathode strip introduce noise which is added to the signal. This noise broadens the position resolution line. Our article gives an analytical tool to estimate the resolution broadening due to the noise per strip and the number of strips involved in the centroid calculation. It is shown that the position resolution increases faster than the square root of the number of strips involved. We also consider the consequence of added interstrip capacitors, intended to diminish the differential nonlinearity. It is shown that the position error increases slower than linearly with the interstrip capacities, due to the cancellation of correlated noise. The estimation we give, can be applied to calculations of position broadening other than the centroid finding. (orig.)

  1. A quantum generalization of intrinsic reaction coordinate using path integral centroid coordinates

    International Nuclear Information System (INIS)

    Shiga, Motoyuki; Fujisaki, Hiroshi

    2012-01-01

    We propose a generalization of the intrinsic reaction coordinate (IRC) for quantum many-body systems described in terms of the mass-weighted ring polymer centroids in the imaginary-time path integral theory. This novel kind of reaction coordinate, which may be called the ''centroid IRC,'' corresponds to the minimum free energy path connecting reactant and product states with a least amount of reversible work applied to the center of masses of the quantum nuclei, i.e., the centroids. We provide a numerical procedure to obtain the centroid IRC based on first principles by combining ab initio path integral simulation with the string method. This approach is applied to NH 3 molecule and N 2 H 5 - ion as well as their deuterated isotopomers to study the importance of nuclear quantum effects in the intramolecular and intermolecular proton transfer reactions. We find that, in the intramolecular proton transfer (inversion) of NH 3 , the free energy barrier for the centroid variables decreases with an amount of about 20% compared to the classical one at the room temperature. In the intermolecular proton transfer of N 2 H 5 - , the centroid IRC is largely deviated from the ''classical'' IRC, and the free energy barrier is reduced by the quantum effects even more drastically.

  2. A variational centroid density procedure for the calculation of transmission coefficients for asymmetric barriers at low temperature

    International Nuclear Information System (INIS)

    Messina, M.; Schenter, G.K.; Garrett, B.C.

    1995-01-01

    The low temperature behavior of the centroid density method of Voth, Chandler, and Miller (VCM) [J. Chem. Phys. 91, 7749 (1989)] is investigated for tunneling through a one-dimensional barrier. We find that the bottleneck for a quantum activated process as defined by VCM does not correspond to the classical bottleneck for the case of an asymmetric barrier. If the centroid density is constrained to be at the classical bottleneck for an asymmetric barrier, the centroid density method can give transmission coefficients that are too large by as much as five orders of magnitude. We follow a variational procedure, as suggested by VCM, whereby the best transmission coefficient is found by varying the position of the centroid until the minimum value for this transmission coefficient is obtained. This is a procedure that is readily generalizable to multidimensional systems. We present calculations on several test systems which show that this variational procedure greatly enhances the accuracy of the centroid density method compared to when the centroid is constrained to be at the barrier top. Furthermore, the relation of this procedure to the low temperature periodic orbit or ''instanton'' approach is discussed. copyright 1995 American Institute of Physics

  3. Networks and centroid metrics for understanding football

    African Journals Online (AJOL)

    Gonçalo Dias

    games. However, it seems that the centroid metric, supported only by the position of players in the field ...... the strategy adopted by the coach (Gama et al., 2014). ... centroid distance as measures of team's tactical performance in youth football.

  4. Optimisation of centroiding algorithms for photon event counting imaging

    International Nuclear Information System (INIS)

    Suhling, K.; Airey, R.W.; Morgan, B.L.

    1999-01-01

    Approaches to photon event counting imaging in which the output events of an image intensifier are located using a centroiding technique have long been plagued by fixed pattern noise in which a grid of dimensions similar to those of the CCD pixels is superimposed on the image. This is caused by a mismatch between the photon event shape and the centroiding algorithm. We have used hyperbolic cosine, Gaussian, Lorentzian, parabolic as well as 3-, 5-, and 7-point centre of gravity algorithms, and hybrids thereof, to assess means of minimising this fixed pattern noise. We show that fixed pattern noise generated by the widely used centre of gravity centroiding is due to intrinsic features of the algorithm. Our results confirm that the recently proposed use of Gaussian centroiding does indeed show a significant reduction of fixed pattern noise compared to centre of gravity centroiding (Michel et al., Mon. Not. R. Astron. Soc. 292 (1997) 611-620). However, the disadvantage of a Gaussian algorithm is a centroiding failure for small pulses, caused by a division by zero, which leads to a loss of detective quantum efficiency (DQE) and to small amounts of residual fixed pattern noise. Using both real data from an image intensifier system employing a progressive scan camera, framegrabber and PC, and also synthetic data from Monte-Carlo simulations, we find that hybrid centroiding algorithms can reduce the fixed pattern noise without loss of resolution or loss of DQE. Imaging a test pattern to assess the features of the different algorithms shows that a hybrid of Gaussian and 3-point centre of gravity centroiding algorithms results in an optimum combination of low fixed pattern noise (lower than a simple Gaussian), high DQE, and high resolution. The Lorentzian algorithm gives the worst results in terms of high fixed pattern noise and low resolution, and the Gaussian and hyperbolic cosine algorithms have the lowest DQEs

  5. The Centroid of a Lie Triple Algebra

    Directory of Open Access Journals (Sweden)

    Xiaohong Liu

    2013-01-01

    Full Text Available General results on the centroids of Lie triple algebras are developed. Centroids of the tensor product of a Lie triple algebra and a unitary commutative associative algebra are studied. Furthermore, the centroid of the tensor product of a simple Lie triple algebra and a polynomial ring is completely determined.

  6. Analysis of the positon resolution in centroid measurements in MWPC

    International Nuclear Information System (INIS)

    Gatti, E.; Longoni, A.

    1981-01-01

    Resolution limits in avalanche localization along the anode wires of an MWPC with cathodes connected by resistors and equally spaced amplifiers, are evaluated. A simple weighted-centroid method and a highly linear method based on a linear centroid finding filter, are considered. The contributions to the variance of the estimator of the avalanche position, due to the series noise of the amplifiers and to the thermal noise of the resistive line are separately calculated and compared. A comparison is made with the resolution of the MWPC with isolated cathodes. The calculations are performed with a distributed model of the diffusive line formed by the cathodes and the resistors. A comparison is also made with the results obtained with a simple lumped model of the diffusive line. A number of graphs useful in determining the best parameters of a MWPC, with a specified position and time resolution, are given. It has been found that, for short resolution times, an MWPC with cathodes connected by resitors presents better resolution (lower variance of the estimator of the avalanche position) than an MWPC with isolated cathodes. Conversely, for long resolution times, the variance of the estimator of the avalanche position is lower in an MWPC with isolated cathodes. (orig.)

  7. FINGERPRINT MATCHING BASED ON PORE CENTROIDS

    Directory of Open Access Journals (Sweden)

    S. Malathi

    2011-05-01

    Full Text Available In recent years there has been exponential growth in the use of bio- metrics for user authentication applications. Automated Fingerprint Identification systems have become popular tool in many security and law enforcement applications. Most of these systems rely on minutiae (ridge ending and bifurcation features. With the advancement in sensor technology, high resolution fingerprint images (1000 dpi pro- vide micro level of features (pores that have proven to be useful fea- tures for identification. In this paper, we propose a new strategy for fingerprint matching based on pores by reliably extracting the pore features The extraction of pores is done by Marker Controlled Wa- tershed segmentation method and the centroids of each pore are con- sidered as feature vectors for matching of two fingerprint images. Experimental results shows that the proposed method has better per- formance with lower false rates and higher accuracy.

  8. Estimating the Doppler centroid of SAR data

    DEFF Research Database (Denmark)

    Madsen, Søren Nørvang

    1989-01-01

    attractive properties. An evaluation based on an existing SEASAT processor is reported. The time-domain algorithms are shown to be extremely efficient with respect to requirements on calculations and memory, and hence they are well suited to real-time systems where the Doppler estimation is based on raw SAR......After reviewing frequency-domain techniques for estimating the Doppler centroid of synthetic-aperture radar (SAR) data, the author describes a time-domain method and highlights its advantages. In particular, a nonlinear time-domain algorithm called the sign-Doppler estimator (SDE) is shown to have...... data. For offline processors where the Doppler estimation is performed on processed data, which removes the problem of partial coverage of bright targets, the ΔE estimator and the CDE (correlation Doppler estimator) algorithm give similar performance. However, for nonhomogeneous scenes it is found...

  9. Networks and centroid metrics for understanding football | Gama ...

    African Journals Online (AJOL)

    This study aimedto verifythe network of contacts resulting from the collective behaviour of professional football teams through the centroid method and networks as well, therebyproviding detailed information about the match to coaches and sport analysts. For this purpose, 999 collective attacking actions from twoteams were ...

  10. Photon counting imaging and centroiding with an electron-bombarded CCD using single molecule localisation software

    International Nuclear Information System (INIS)

    Hirvonen, Liisa M.; Barber, Matthew J.; Suhling, Klaus

    2016-01-01

    Photon event centroiding in photon counting imaging and single-molecule localisation in super-resolution fluorescence microscopy share many traits. Although photon event centroiding has traditionally been performed with simple single-iteration algorithms, we recently reported that iterative fitting algorithms originally developed for single-molecule localisation fluorescence microscopy work very well when applied to centroiding photon events imaged with an MCP-intensified CMOS camera. Here, we have applied these algorithms for centroiding of photon events from an electron-bombarded CCD (EBCCD). We find that centroiding algorithms based on iterative fitting of the photon events yield excellent results and allow fitting of overlapping photon events, a feature not reported before and an important aspect to facilitate an increased count rate and shorter acquisition times.

  11. Bayesian centroid estimation for motif discovery.

    Science.gov (United States)

    Carvalho, Luis

    2013-01-01

    Biological sequences may contain patterns that signal important biomolecular functions; a classical example is regulation of gene expression by transcription factors that bind to specific patterns in genomic promoter regions. In motif discovery we are given a set of sequences that share a common motif and aim to identify not only the motif composition, but also the binding sites in each sequence of the set. We propose a new centroid estimator that arises from a refined and meaningful loss function for binding site inference. We discuss the main advantages of centroid estimation for motif discovery, including computational convenience, and how its principled derivation offers further insights about the posterior distribution of binding site configurations. We also illustrate, using simulated and real datasets, that the centroid estimator can differ from the traditional maximum a posteriori or maximum likelihood estimators.

  12. Bayesian centroid estimation for motif discovery.

    Directory of Open Access Journals (Sweden)

    Luis Carvalho

    Full Text Available Biological sequences may contain patterns that signal important biomolecular functions; a classical example is regulation of gene expression by transcription factors that bind to specific patterns in genomic promoter regions. In motif discovery we are given a set of sequences that share a common motif and aim to identify not only the motif composition, but also the binding sites in each sequence of the set. We propose a new centroid estimator that arises from a refined and meaningful loss function for binding site inference. We discuss the main advantages of centroid estimation for motif discovery, including computational convenience, and how its principled derivation offers further insights about the posterior distribution of binding site configurations. We also illustrate, using simulated and real datasets, that the centroid estimator can differ from the traditional maximum a posteriori or maximum likelihood estimators.

  13. Systematic shifts of evaluated charge centroid for the cathode read-out multiwire proportional chamber

    International Nuclear Information System (INIS)

    Endo, I.; Kawamoto, T.; Mizuno, Y.; Ohsugi, T.; Taniguchi, T.; Takeshita, T.

    1981-01-01

    We have investigated the systematic error associtated with the charge centroid evaluation for the cathode read-out multiwire proportional chamber. Correction curves for the systematic error according to six centroid finding algorithms have been obtained by using the charge distribution calculated in a simple electrostatic mode. They have been experimentally examined and proved to be essential for the accurate determination of the irradiated position. (orig.)

  14. On the timing properties of germanium detectors: The centroid diagrams of prompt photopeaks and Compton events

    International Nuclear Information System (INIS)

    Penev, I.; Andrejtscheff, W.; Protochristov, Ch.; Zhelev, Zh.

    1987-01-01

    In the applications of the generalized centroid shift method with germanium detectors, the energy dependence of the time centroids of prompt photopeaks (zero-time line) and of Compton background events reveal a peculiar behavior crossing each other at about 100 keV. The effect is plausibly explained as associated with the ratio of γ-quanta causing the photoeffect and Compton scattering, respectively, at the boundaries of the detector. (orig.)

  15. Finding protein sites using machine learning methods

    Directory of Open Access Journals (Sweden)

    Jaime Leonardo Bobadilla Molina

    2003-07-01

    Full Text Available The increasing amount of protein three-dimensional (3D structures determined by x-ray and NMR technologies as well as structures predicted by computational methods results in the need for automated methods to provide inital annotations. We have developed a new method for recognizing sites in three-dimensional protein structures. Our method is based on a previosly reported algorithm for creating descriptions of protein microenviroments using physical and chemical properties at multiple levels of detail. The recognition method takes three inputs: 1. A set of control nonsites that share some structural or functional role. 2. A set of control nonsites that lack this role. 3. A single query site. A support vector machine classifier is built using feature vectors where each component represents a property in a given volume. Validation against an independent test set shows that this recognition approach has high sensitivity and specificity. We also describe the results of scanning four calcium binding proteins (with the calcium removed using a three dimensional grid of probe points at 1.25 angstrom spacing. The system finds the sites in the proteins giving points at or near the blinding sites. Our results show that property based descriptions along with support vector machines can be used for recognizing protein sites in unannotated structures.

  16. Centroids of effective interactions from measured single-particle energies: An application

    International Nuclear Information System (INIS)

    Cole, B.J.

    1990-01-01

    Centroids of the effective nucleon-nucleon interaction for the mass region A=28--64 are extracted directly from experimental single-particle spectra, by comparing single-particle energies relative to different cores. Uncertainties in the centroids are estimated at approximately 100 keV, except in cases of exceptional fragmentation of the single-particle strength. The use of a large number of inert cores allows the dependence of the interaction on mass or model space to be investigated. The method permits accurate empirical modifications to be made to realistic interactions calculated from bare nucleon-nucleon potentials, which are known to possess defective centroids in many cases. In addition, the centroids can be used as input to the more sophisticated fitting procedures that are employed to produce matrix elements of the effective interaction

  17. Formulation of state projected centroid molecular dynamics: Microcanonical ensemble and connection to the Wigner distribution

    Science.gov (United States)

    Orr, Lindsay; Hernández de la Peña, Lisandro; Roy, Pierre-Nicholas

    2017-06-01

    A derivation of quantum statistical mechanics based on the concept of a Feynman path centroid is presented for the case of generalized density operators using the projected density operator formalism of Blinov and Roy [J. Chem. Phys. 115, 7822-7831 (2001)]. The resulting centroid densities, centroid symbols, and centroid correlation functions are formulated and analyzed in the context of the canonical equilibrium picture of Jang and Voth [J. Chem. Phys. 111, 2357-2370 (1999)]. The case where the density operator projects onto a particular energy eigenstate of the system is discussed, and it is shown that one can extract microcanonical dynamical information from double Kubo transformed correlation functions. It is also shown that the proposed projection operator approach can be used to formally connect the centroid and Wigner phase-space distributions in the zero reciprocal temperature β limit. A Centroid Molecular Dynamics (CMD) approximation to the state-projected exact quantum dynamics is proposed and proven to be exact in the harmonic limit. The state projected CMD method is also tested numerically for a quartic oscillator and a double-well potential and found to be more accurate than canonical CMD. In the case of a ground state projection, this method can resolve tunnelling splittings of the double well problem in the higher barrier regime where canonical CMD fails. Finally, the state-projected CMD framework is cast in a path integral form.

  18. Formulation of state projected centroid molecular dynamics: Microcanonical ensemble and connection to the Wigner distribution.

    Science.gov (United States)

    Orr, Lindsay; Hernández de la Peña, Lisandro; Roy, Pierre-Nicholas

    2017-06-07

    A derivation of quantum statistical mechanics based on the concept of a Feynman path centroid is presented for the case of generalized density operators using the projected density operator formalism of Blinov and Roy [J. Chem. Phys. 115, 7822-7831 (2001)]. The resulting centroid densities, centroid symbols, and centroid correlation functions are formulated and analyzed in the context of the canonical equilibrium picture of Jang and Voth [J. Chem. Phys. 111, 2357-2370 (1999)]. The case where the density operator projects onto a particular energy eigenstate of the system is discussed, and it is shown that one can extract microcanonical dynamical information from double Kubo transformed correlation functions. It is also shown that the proposed projection operator approach can be used to formally connect the centroid and Wigner phase-space distributions in the zero reciprocal temperature β limit. A Centroid Molecular Dynamics (CMD) approximation to the state-projected exact quantum dynamics is proposed and proven to be exact in the harmonic limit. The state projected CMD method is also tested numerically for a quartic oscillator and a double-well potential and found to be more accurate than canonical CMD. In the case of a ground state projection, this method can resolve tunnelling splittings of the double well problem in the higher barrier regime where canonical CMD fails. Finally, the state-projected CMD framework is cast in a path integral form.

  19. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    International Nuclear Information System (INIS)

    Briggs, A.M.; Greig, A.M.; Wrigley, T.V.; Tully, E.A.; Adams, P.E.; Bennell, K.L.

    2007-01-01

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r 0.83). Correspondence between measures was moderate for the Cobb method (r 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  20. Radiographic measures of thoracic kyphosis in osteoporosis: Cobb and vertebral centroid angles

    Energy Technology Data Exchange (ETDEWEB)

    Briggs, A.M.; Greig, A.M. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia); University of Melbourne, Department of Medicine, Royal Melbourne Hospital, Victoria (Australia); Wrigley, T.V.; Tully, E.A.; Adams, P.E.; Bennell, K.L. [University of Melbourne, Centre for Health, Exercise and Sports Medicine, School of Physiotherapy, Victoria (Australia)

    2007-08-15

    Several measures can quantify thoracic kyphosis from radiographs, yet their suitability for people with osteoporosis remains uncertain. The aim of this study was to examine the validity and reliability of the vertebral centroid and Cobb angles in people with osteoporosis. Lateral radiographs of the thoracic spine were captured in 31 elderly women with osteoporosis. Thoracic kyphosis was measured globally (T1-T12) and regionally (T4-T9) using Cobb and vertebral centroid angles. Multisegmental curvature was also measured by fitting polynomial functions to the thoracic curvature profile. Canonical and Pearson correlations were used to examine correspondence; agreement between measures was examined with linear regression. Moderate to high intra- and inter-rater reliability was achieved (SEM = 0.9-4.0 ). Concurrent validity of the simple measures was established against multisegmental curvature (r = 0.88-0.98). Strong association was observed between the Cobb and centroid angles globally (r = 0.84) and regionally (r = 0.83). Correspondence between measures was moderate for the Cobb method (r = 0.72), yet stronger for the centroid method (r = 0.80). The Cobb angle was 20% greater for regional measures due to the influence of endplate tilt. Regional Cobb and centroid angles are valid and reliable measures of thoracic kyphosis in people with osteoporosis. However, the Cobb angle is biased by endplate tilt, suggesting that the centroid angle is more appropriate for this population. (orig.)

  1. Alternative Polyadenylation: Methods, Findings, and Impacts

    Directory of Open Access Journals (Sweden)

    Wei Chen

    2017-10-01

    Full Text Available Alternative polyadenylation (APA, a phenomenon that RNA molecules with different 3′ ends originate from distinct polyadenylation sites of a single gene, is emerging as a mechanism widely used to regulate gene expression. In the present review, we first summarized various methods prevalently adopted in APA study, mainly focused on the next-generation sequencing (NGS-based techniques specially designed for APA identification, the related bioinformatics methods, and the strategies for APA study in single cells. Then we summarized the main findings and advances so far based on these methods, including the preferences of alternative polyA (pA site, the biological processes involved, and the corresponding consequences. We especially categorized the APA changes discovered so far and discussed their potential functions under given conditions, along with the possible underlying molecular mechanisms. With more in-depth studies on extensive samples, more signatures and functions of APA will be revealed, and its diverse roles will gradually heave in sight. Keywords: Alternative polyadenylation, Next-generation sequencing, 3′UTR, Alternative splicing, Gene regulation

  2. Prediction of RNA secondary structure using generalized centroid estimators.

    Science.gov (United States)

    Hamada, Michiaki; Kiryu, Hisanori; Sato, Kengo; Mituyama, Toutai; Asai, Kiyoshi

    2009-02-15

    Recent studies have shown that the methods for predicting secondary structures of RNAs on the basis of posterior decoding of the base-pairing probabilities has an advantage with respect to prediction accuracy over the conventionally utilized minimum free energy methods. However, there is room for improvement in the objective functions presented in previous studies, which are maximized in the posterior decoding with respect to the accuracy measures for secondary structures. We propose novel estimators which improve the accuracy of secondary structure prediction of RNAs. The proposed estimators maximize an objective function which is the weighted sum of the expected number of the true positives and that of the true negatives of the base pairs. The proposed estimators are also improved versions of the ones used in previous works, namely CONTRAfold for secondary structure prediction from a single RNA sequence and McCaskill-MEA for common secondary structure prediction from multiple alignments of RNA sequences. We clarify the relations between the proposed estimators and the estimators presented in previous works, and theoretically show that the previous estimators include additional unnecessary terms in the evaluation measures with respect to the accuracy. Furthermore, computational experiments confirm the theoretical analysis by indicating improvement in the empirical accuracy. The proposed estimators represent extensions of the centroid estimators proposed in Ding et al. and Carvalho and Lawrence, and are applicable to a wide variety of problems in bioinformatics. Supporting information and the CentroidFold software are available online at: http://www.ncrna.org/software/centroidfold/.

  3. Transverse centroid oscillations in solenoidially focused beam transport lattices

    International Nuclear Information System (INIS)

    Lund, Steven M.; Wootton, Christopher J.; Lee, Edward P.

    2009-01-01

    Transverse centroid oscillations are analyzed for a beam in a solenoid transport lattice. Linear equations of motion are derived that describe small-amplitude centroid oscillations induced by displacement and rotational misalignments of the focusing solenoids in the transport lattice, dipole steering elements, and initial centroid offset errors. These equations are analyzed in a local rotating Larmor frame to derive complex-variable 'alignment functions' and 'bending functions' that efficiently describe the characteristics of the centroid oscillations induced by both mechanical misalignments of the solenoids and dipole steering elements. The alignment and bending functions depend only on the properties of the ideal lattice in the absence of errors and steering, and have associated expansion amplitudes set by the misalignments and steering fields, respectively. Applications of this formulation are presented for statistical analysis of centroid oscillations, calculation of actual lattice misalignments from centroid measurements, and optimal beam steering.

  4. Measurement of centroid trajectory of Dragon-I electron beam

    International Nuclear Information System (INIS)

    Jiang Xiaoguo; Wang Yuan; Zhang Wenwei; Zhang Kaizhi; Li Jing; Li Chenggang; Yang Guojun

    2005-01-01

    The control of the electron beam in an intense current linear induction accelerator (LIA) is very important. The center position of the electron beam and the beam profile are two important parameters which should be measured accurately. The setup of a time-resolved measurement system and a data processing method for determining the beam center position are introduced for the purpose of obtaining Dragon-I electron beam trajectory including beam profile. The actual results show that the centroid position error can be controlled in one to two pixels. the time-resolved beam centroid trajectory of Dragon-I (18.5 MeV, 2 kA, 90 ns) is obtained recently in 10 ns interval, 3 ns exposure time with a multi-frame gated camera. The results show that the screw movement of the electron beam is mainly limited in an area with a radius of 0.5 mm and the time-resolved diameters of the beam are 8.4 mm, 8.8 mm, 8.5 mm, 9.3 mm and 7.6 mm. These results have provided a very important support to several research areas such as beam trajectory tuning and beam transmission. (authors)

  5. Accurate Alignment of Plasma Channels Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2011-01-01

    A technique has been developed to accurately align a laser beam through a plasma channel by minimizing the shift in laser centroid and angle at the channel outptut. If only the shift in centroid or angle is measured, then accurate alignment is provided by minimizing laser centroid motion at the channel exit as the channel properties are scanned. The improvement in alignment accuracy provided by this technique is important for minimizing electron beam pointing errors in laser plasma accelerators.

  6. Automatic centroid detection and surface measurement with a digital Shack–Hartmann wavefront sensor

    International Nuclear Information System (INIS)

    Yin, Xiaoming; Zhao, Liping; Li, Xiang; Fang, Zhongping

    2010-01-01

    With the breakthrough of manufacturing technologies, the measurement of surface profiles is becoming a big issue. A Shack–Hartmann wavefront sensor (SHWS) provides a promising technology for non-contact surface measurement with a number of advantages over interferometry. The SHWS splits the incident wavefront into many subsections and transfers the distorted wavefront detection into the centroid measurement. So the accuracy of the centroid measurement determines the accuracy of the SHWS. In this paper, we have presented a new centroid measurement algorithm based on an adaptive thresholding and dynamic windowing method by utilizing image-processing techniques. Based on this centroid detection method, we have developed a digital SHWS system which can automatically detect centroids of focal spots, reconstruct the wavefront and measure the 3D profile of the surface. The system has been tested with various simulated and real surfaces such as flat surfaces, spherical and aspherical surfaces as well as deformable surfaces. The experimental results demonstrate that the system has good accuracy, repeatability and immunity to optical misalignment. The system is also suitable for on-line applications of surface measurement

  7. Star point centroid algorithm based on background forecast

    Science.gov (United States)

    Wang, Jin; Zhao, Rujin; Zhu, Nan

    2014-09-01

    The calculation of star point centroid is a key step of improving star tracker measuring error. A star map photoed by APS detector includes several noises which have a great impact on veracity of calculation of star point centroid. Through analysis of characteristic of star map noise, an algorithm of calculation of star point centroid based on background forecast is presented in this paper. The experiment proves the validity of the algorithm. Comparing with classic algorithm, this algorithm not only improves veracity of calculation of star point centroid, but also does not need calibration data memory. This algorithm is applied successfully in a certain star tracker.

  8. Centroid vetting of transiting planet candidates from the Next Generation Transit Survey

    Science.gov (United States)

    Günther, Maximilian N.; Queloz, Didier; Gillen, Edward; McCormac, James; Bayliss, Daniel; Bouchy, Francois; Walker, Simon. R.; West, Richard G.; Eigmüller, Philipp; Smith, Alexis M. S.; Armstrong, David J.; Burleigh, Matthew; Casewell, Sarah L.; Chaushev, Alexander P.; Goad, Michael R.; Grange, Andrew; Jackman, James; Jenkins, James S.; Louden, Tom; Moyano, Maximiliano; Pollacco, Don; Poppenhaeger, Katja; Rauer, Heike; Raynard, Liam; Thompson, Andrew P. G.; Udry, Stéphane; Watson, Christopher A.; Wheatley, Peter J.

    2017-11-01

    The Next Generation Transit Survey (NGTS), operating in Paranal since 2016, is a wide-field survey to detect Neptunes and super-Earths transiting bright stars, which are suitable for precise radial velocity follow-up and characterization. Thereby, its sub-mmag photometric precision and ability to identify false positives are crucial. Particularly, variable background objects blended in the photometric aperture frequently mimic Neptune-sized transits and are costly in follow-up time. These objects can best be identified with the centroiding technique: if the photometric flux is lost off-centre during an eclipse, the flux centroid shifts towards the centre of the target star. Although this method has successfully been employed by the Kepler mission, it has previously not been implemented from the ground. We present a fully automated centroid vetting algorithm developed for NGTS, enabled by our high-precision autoguiding. Our method allows detecting centroid shifts with an average precision of 0.75 milli-pixel (mpix), and down to 0.25 mpix for specific targets, for a pixel size of 4.97 arcsec. The algorithm is now part of the NGTS candidate vetting pipeline and automatically employed for all detected signals. Further, we develop a joint Bayesian fitting model for all photometric and centroid data, allowing to disentangle which object (target or background) is causing the signal, and what its astrophysical parameters are. We demonstrate our method on two NGTS objects of interest. These achievements make NGTS the first ground-based wide-field transit survey ever to successfully apply the centroiding technique for automated candidate vetting, enabling the production of a robust candidate list before follow-up.

  9. Methods and findings of the SNR study

    International Nuclear Information System (INIS)

    Koeberlein, K.; Schaefer, H.; Spindler, H.

    1983-01-01

    A featfinding committee of the German Federal Parliament in July 1980 recommended to perform a ''risk-oriented study'' of the SNR-300, the German 300 MW fast breeder prototype reactor being under construction in Kalkar. The main aim of this study was to allow a comparative safety evaluation between the SNR-300 and a modern PWR, thus to prepare a basis for a political decision on the SNR-300. Methods and main results of the study are presented in this paper. In the first step of the risk analysis six groups of accidents have been identified which may initiate core destruction. These groups comprise all conceivable courses, potentially leading to core destruction. By reliability analyses, expected frequency of each group has been calculated. In the accident analysis potential failure modes of the reactor tank have been investigated. Core destruction may be accompanied by the release of significant amounts of mechanical energy. The primary coolant system of SNR-300 is designed to withstand mechanical energy releases up to 370 MJ. Design features make it possible to cool the molten core inside the reactor tank. (orig./RW) [de

  10. Hybridized centroid technique for 3D Molodensky-Badekas ...

    African Journals Online (AJOL)

    In view of this, the present study developed and tested two new hybrid centroid techniques known as the harmonic-quadratic mean and arithmetic-quadratic mean centroids. The proposed hybrid approaches were compared with the geometric mean, harmonic mean, median, quadratic mean and arithmetic mean. In addition ...

  11. Feature selection and nearest centroid classification for protein mass spectrometry

    Directory of Open Access Journals (Sweden)

    Levner Ilya

    2005-03-01

    selection methods using the nearest centroid classifier and found that several reportedly state-of-the-art algorithms in fact perform rather poorly when tested via stratified cross-validation. The revealed inconsistencies provide clear evidence that algorithm evaluation should be performed on several data sets using a consistent (i.e., non-randomized, stratified cross-validation procedure in order for the conclusions to be statistically sound.

  12. Improved measurements of RNA structure conservation with generalized centroid estimators

    Directory of Open Access Journals (Sweden)

    Yohei eOkada

    2011-08-01

    Full Text Available Identification of non-protein-coding RNAs (ncRNAs in genomes is acrucial task for not only molecular cell biology but alsobioinformatics. Secondary structures of ncRNAs are employed as a keyfeature of ncRNA analysis since biological functions of ncRNAs aredeeply related to their secondary structures. Although the minimumfree energy (MFE structure of an RNA sequence is regarded as the moststable structure, MFE alone could not be an appropriate measure foridentifying ncRNAs since the free energy is heavily biased by thenucleotide composition. Therefore, instead of MFE itself, severalalternative measures for identifying ncRNAs have been proposed such asthe structure conservation index (SCI and the base pair distance(BPD, both of which employ MFE structures. However, thesemeasurements are unfortunately not suitable for identifying ncRNAs insome cases including the genome-wide search and incur high falsediscovery rate. In this study, we propose improved measurements basedon SCI and BPD, applying generalized centroid estimators toincorporate the robustness against low quality multiple alignments.Our experiments show that our proposed methods achieve higher accuracythan the original SCI and BPD for not only human-curated structuralalignments but also low quality alignments produced by CLUSTALW. Furthermore, the centroid-based SCI on CLUSTAL W alignments is moreaccurate than or comparable with that of the original SCI onstructural alignments generated with RAF, a high quality structuralaligner, for which two-fold expensive computational time is requiredon average. We conclude that our methods are more suitable forgenome-wide alignments which are of low quality from the point of viewon secondary structures than the original SCI and BPD.

  13. A centroid model of species distribution with applications to the Carolina wren Thryothorus ludovicianus and house finch Haemorhous mexicanus in the United States

    Science.gov (United States)

    Huang, Qiongyu; Sauer, John R.; Swatantran, Anu; Dubayah, Ralph

    2016-01-01

    Drastic shifts in species distributions are a cause of concern for ecologists. Such shifts pose great threat to biodiversity especially under unprecedented anthropogenic and natural disturbances. Many studies have documented recent shifts in species distributions. However, most of these studies are limited to regional scales, and do not consider the abundance structure within species ranges. Developing methods to detect systematic changes in species distributions over their full ranges is critical for understanding the impact of changing environments and for successful conservation planning. Here, we demonstrate a centroid model for range-wide analysis of distribution shifts using the North American Breeding Bird Survey. The centroid model is based on a hierarchical Bayesian framework which models population change within physiographic strata while accounting for several factors affecting species detectability. Yearly abundance-weighted range centroids are estimated. As case studies, we derive annual centroids for the Carolina wren and house finch in their ranges in the U.S. We further evaluate the first-difference correlation between species’ centroid movement and changes in winter severity, total population abundance. We also examined associations of change in centroids from sub-ranges. Change in full-range centroid movements of Carolina wren significantly correlate with snow cover days (r = −0.58). For both species, the full-range centroid shifts also have strong correlation with total abundance (r = 0.65, and 0.51 respectively). The movements of the full-range centroids of the two species are correlated strongly (up to r = 0.76) with that of the sub-ranges with more drastic population changes. Our study demonstrates the usefulness of centroids for analyzing distribution changes in a two-dimensional spatial context. Particularly it highlights applications that associate the centroid with factors such as environmental stressors, population characteristics

  14. A focal plane metrology system and PSF centroiding experiment

    Science.gov (United States)

    Li, Haitao; Li, Baoquan; Cao, Yang; Li, Ligang

    2016-10-01

    In this paper, we present an overview of a detector array equipment metrology testbed and a micro-pixel centroiding experiment currently under development at the National Space Science Center, Chinese Academy of Sciences. We discuss on-going development efforts aimed at calibrating the intra-/inter-pixel quantum efficiency and pixel positions for scientific grade CMOS detector, and review significant progress in achieving higher precision differential centroiding for pseudo star images in large area back-illuminated CMOS detector. Without calibration of pixel positions and intrapixel response, we have demonstrated that the standard deviation of differential centroiding is below 2.0e-3 pixels.

  15. Study on Zero-Doppler Centroid Control for GEO SAR Ground Observation

    Directory of Open Access Journals (Sweden)

    Yicheng Jiang

    2014-01-01

    Full Text Available In geosynchronous Earth orbit SAR (GEO SAR, Doppler centroid compensation is a key step for imaging process, which could be performed by the attitude steering of a satellite platform. However, this zero-Doppler centroid control method does not work well when the look angle of radar is out of an expected range. This paper primarily analyzes the Doppler properties of GEO SAR in the Earth rectangular coordinate. Then, according to the actual conditions of the GEO SAR ground observation, the effective range is presented by the minimum and maximum possible look angles which are directly related to the orbital parameters. Based on the vector analysis, a new approach for zero-Doppler centroid control in GEO SAR, performing the attitude steering by a combination of pitch and roll rotation, is put forward. This approach, considering the Earth’s rotation and elliptical orbit effects, can accurately reduce the residual Doppler centroid. All the simulation results verify the correctness of the range of look angle and the proposed steering method.

  16. Ambiguity Of Doppler Centroid In Synthetic-Aperture Radar

    Science.gov (United States)

    Chang, Chi-Yung; Curlander, John C.

    1991-01-01

    Paper discusses performances of two algorithms for resolution of ambiguity in estimated Doppler centroid frequency of echoes in synthetic-aperture radar. One based on range-cross-correlation technique, other based on multiple-pulse-repetition-frequency technique.

  17. Doppler Centroid Estimation for Airborne SAR Supported by POS and DEM

    Directory of Open Access Journals (Sweden)

    CHENG Chunquan

    2015-05-01

    Full Text Available It is difficult to estimate the Doppler frequency and modulating rate for airborne SAR by using traditional vector method due to instable flight and complex terrain. In this paper, it is qualitatively analyzed that the impacts of POS, DEM and their errors on airborne SAR Doppler parameters. Then an innovative vector method is presented based on the range-coplanarity equation to estimate the Doppler centroid taking the POS and DEM as auxiliary data. The effectiveness of the proposed method is validated and analyzed via the simulation experiments. The theoretical analysis and experimental results show that the method can be used to estimate the Doppler centroid with high accuracy even in the cases of high relief, instable flight, and large squint SAR.

  18. Automatic extraction of nuclei centroids of mouse embryonic cells from fluorescence microscopy images.

    Directory of Open Access Journals (Sweden)

    Md Khayrul Bashar

    Full Text Available Accurate identification of cell nuclei and their tracking using three dimensional (3D microscopic images is a demanding task in many biological studies. Manual identification of nuclei centroids from images is an error-prone task, sometimes impossible to accomplish due to low contrast and the presence of noise. Nonetheless, only a few methods are available for 3D bioimaging applications, which sharply contrast with 2D analysis, where many methods already exist. In addition, most methods essentially adopt segmentation for which a reliable solution is still unknown, especially for 3D bio-images having juxtaposed cells. In this work, we propose a new method that can directly extract nuclei centroids from fluorescence microscopy images. This method involves three steps: (i Pre-processing, (ii Local enhancement, and (iii Centroid extraction. The first step includes two variations: first variation (Variant-1 uses the whole 3D pre-processed image, whereas the second one (Variant-2 modifies the preprocessed image to the candidate regions or the candidate hybrid image for further processing. At the second step, a multiscale cube filtering is employed in order to locally enhance the pre-processed image. Centroid extraction in the third step consists of three stages. In Stage-1, we compute a local characteristic ratio at every voxel and extract local maxima regions as candidate centroids using a ratio threshold. Stage-2 processing removes spurious centroids from Stage-1 results by analyzing shapes of intensity profiles from the enhanced image. An iterative procedure based on the nearest neighborhood principle is then proposed to combine if there are fragmented nuclei. Both qualitative and quantitative analyses on a set of 100 images of 3D mouse embryo are performed. Investigations reveal a promising achievement of the technique presented in terms of average sensitivity and precision (i.e., 88.04% and 91.30% for Variant-1; 86.19% and 95.00% for Variant-2

  19. Plasma Channel Diagnostic Based on Laser Centroid Oscillations

    International Nuclear Information System (INIS)

    Gonsalves, Anthony; Nakamura, Kei; Lin, Chen; Osterhoff, Jens; Shiraishi, Satomi; Schroeder, Carl; Geddes, Cameron; Toth, Csaba; Esarey, Eric; Leemans, Wim

    2010-01-01

    A technique has been developed for measuring the properties of discharge-based plasma channels by monitoring the centroid location of a laser beam exiting the channel as a function of input alignment offset between the laser and the channel. The centroid position of low-intensity ( 14 Wcm -2 ) laser pulses focused at the input of a hydrogen-filled capillary discharge waveguide was scanned and the exit positions recorded to determine the channel shape and depth with an accuracy of a few %. In addition, accurate alignment of the laser beam through the plasma channel can be provided by minimizing laser centroid motion at the channel exit as the channel depth is scanned either by scanning the plasma density or the discharge timing. The improvement in alignment accuracy provided by this technique will be crucial for minimizing electron beam pointing errors in laser plasma accelerators.

  20. Communications: On artificial frequency shifts in infrared spectra obtained from centroid molecular dynamics: Quantum liquid water

    Science.gov (United States)

    Ivanov, Sergei D.; Witt, Alexander; Shiga, Motoyuki; Marx, Dominik

    2010-01-01

    Centroid molecular dynamics (CMD) is a popular method to extract approximate quantum dynamics from path integral simulations. Very recently we have shown that CMD gas phase infrared spectra exhibit significant artificial redshifts of stretching peaks, due to the so-called "curvature problem" imprinted by the effective centroid potential. Here we provide evidence that for condensed phases, and in particular for liquid water, CMD produces pronounced artificial redshifts for high-frequency vibrations such as the OH stretching band. This peculiar behavior intrinsic to the CMD method explains part of the unexpectedly large quantum redshifts of the stretching band of liquid water compared to classical frequencies, which is improved after applying a simple and rough "harmonic curvature correction."

  1. Weierstrass method for quaternionic polynomial root-finding

    Science.gov (United States)

    Falcão, M. Irene; Miranda, Fernando; Severino, Ricardo; Soares, M. Joana

    2018-01-01

    Quaternions, introduced by Hamilton in 1843 as a generalization of complex numbers, have found, in more recent years, a wealth of applications in a number of different areas which motivated the design of efficient methods for numerically approximating the zeros of quaternionic polynomials. In fact, one can find in the literature recent contributions to this subject based on the use of complex techniques, but numerical methods relying on quaternion arithmetic remain scarce. In this paper we propose a Weierstrass-like method for finding simultaneously {\\sl all} the zeros of unilateral quaternionic polynomials. The convergence analysis and several numerical examples illustrating the performance of the method are also presented.

  2. Major shell centroids in the symplectic collective model

    International Nuclear Information System (INIS)

    Draayer, J.P.; Rosensteel, G.; Tulane Univ., New Orleans, LA

    1983-01-01

    Analytic expressions are given for the major shell centroids of the collective potential V(#betta#, #betta#) and the shape observable #betta# 2 in the Sp(3,R) symplectic model. The tools of statistical spectroscopy are shown to be useful, firstly, in translating a requirement that the underlying shell structure be preserved into constraints on the parameters of the collective potential and, secondly, in giving a reasonable estimate for a truncation of the infinite dimensional symplectic model space from experimental B(E2) transition strengths. Results based on the centroid information are shown to compare favorably with results from exact calculations in the case of 20 Ne. (orig.)

  3. An Adaptive Connectivity-based Centroid Algorithm for Node Positioning in Wireless Sensor Networks

    Directory of Open Access Journals (Sweden)

    Aries Pratiarso

    2015-06-01

    Full Text Available In wireless sensor network applications, the position of nodes is randomly distributed following the contour of the observation area. A simple solution without any measurement tools is provided by range-free method. However, this method yields the coarse estimating position of the nodes. In this paper, we propose Adaptive Connectivity-based (ACC algorithm. This algorithm is a combination of Centroid as range-free based algorithm, and hop-based connectivity algorithm. Nodes have a possibility to estimate their own position based on the connectivity level between them and their reference nodes. Each node divides its communication range into several regions where each of them has a certain weight depends on the received signal strength. The weighted value is used to obtain the estimated position of nodes. Simulation result shows that the proposed algorithm has up to 3 meter error of estimated position on 100x100 square meter observation area, and up to 3 hop counts for 80 meters' communication range. The proposed algorithm performs an average error positioning up to 10 meters better than Weighted Centroid algorithm. Keywords: adaptive, connectivity, centroid, range-free.

  4. Determination of star bodies from p-centroid bodies

    Indian Academy of Sciences (India)

    An immediate consequence of the definition of the p-centroid body of K is that for any .... The dual mixed volume ˜V−p(K, L) of star bodies K, L can be defined by d. −p ..... [16] Lindenstrauss J and Milman V D, Local theory of normed spaces and ...

  5. Determination of star bodies from p-centroid bodies

    Indian Academy of Sciences (India)

    In this paper, we prove that an origin-symmetric star body is uniquely determined by its -centroid body. Furthermore, using spherical harmonics, we establish a result for non-symmetric star bodies. As an application, we show that there is a unique member of p ⟨ K ⟩ characterized by having larger volume than any other ...

  6. A new method for finding vacua in string phenomenology

    Energy Technology Data Exchange (ETDEWEB)

    Gray, James [Institut d' Astrophysique de Paris and APC, Universite de Paris 7, 98 bis, Bd. Arago 75014, Paris (France); He, Yang-Hui [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)]|[Merton College, Oxford, OX1 4JD and Mathematical Institute, Oxford University, Oxford (United Kingdom); Ilderton, Anton [School of Mathematics and Statistics, University of Plymouth, Drake Circus, Plymouth PL4 8AA (United Kingdom); Lukas, Andre [Rudolf Peierls Centre for Theoretical Physics, University of Oxford, 1 Keble Road, Oxford OX1 3NP (United Kingdom)

    2007-05-15

    One of the central problems of string-phenomenology is to find stable vacua in the four dimensional effective theories which result from compactification. We present an algorithmic method to find all of the vacua of any given string-phenomenological system in a huge class. In particular, this paper reviews and then extends hep-th/0606122 to include various nonperturbative effects. These include gaugino condensation and instantonic contributions to the superpotential. (authors)

  7. Intraoperative cyclorotation and pupil centroid shift during LASIK and PRK.

    Science.gov (United States)

    Narváez, Julio; Brucks, Matthew; Zimmerman, Grenith; Bekendam, Peter; Bacon, Gregory; Schmid, Kristin

    2012-05-01

    To determine the degree of cyclorotation and centroid shift in the x and y axis that occurs intraoperatively during LASIK and photorefractive keratectomy (PRK). Intraoperative cyclorotation and centroid shift were measured in 63 eyes from 34 patients with a mean age of 34 years (range: 20 to 56 years) undergoing either LASIK or PRK. Preoperatively, an iris image of each eye was obtained with the VISX WaveScan Wavefront System (Abbott Medical Optics Inc) with iris registration. A VISX Star S4 (Abbott Medical Optics Inc) laser was later used to measure cyclotorsion and pupil centroid shift at the beginning of the refractive procedure and after flap creation or epithelial removal. The mean change in intraoperative cyclorotation was 1.48±1.11° in LASIK eyes and 2.02±2.63° in PRK eyes. Cyclorotation direction changed by >2° in 21% of eyes after flap creation in LASIK and in 32% of eyes after epithelial removal in PRK. The respective mean intraoperative shift in the x axis and y axis was 0.13±0.15 mm and 0.17±0.14 mm, respectively, in LASIK eyes, and 0.09±0.07 mm and 0.10±0.13 mm, respectively, in PRK eyes. Intraoperative centroid shifts >100 μm in either the x axis or y axis occurred in 71% of LASIK eyes and 55% of PRK eyes. Significant changes in cyclotorsion and centroid shifts were noted prior to surgery as well as intraoperatively with both LASIK and PRK. It may be advantageous to engage iris registration immediately prior to ablation to provide a reference point representative of eye position at the initiation of laser delivery. Copyright 2012, SLACK Incorporated.

  8. Optimizing the calculation of point source count-centroid in pixel size measurement

    International Nuclear Information System (INIS)

    Zhou Luyi; Kuang Anren; Su Xianyu

    2004-01-01

    Pixel size is an important parameter of gamma camera and SPECT. A number of methods are used for its accurate measurement. In the original count-centroid method, where the image of a point source (PS) is acquired and its count-centroid calculated to represent PS position in the image, background counts are inevitable. Thus the measured count-centroid (X m ) is an approximation of the true count-centroid (X p ) of the PS, i.e. X m =X p + (X b -X p )/(1+R p /R b ), where Rp is the net counting rate of the PS, X b the background count-centroid and Rb the background counting. To get accurate measurement, R p must be very big, which is unpractical, resulting in the variation of measured pixel size. R p -independent calculation of PS count-centroid is desired. Methods: The proposed method attempted to eliminate the effect of the term (X b -X p )/(1 + R p /R b ) by bringing X b closer to X p and by reducing R b . In the acquired PS image, a circular ROI was generated to enclose the PS, the pixel with the maximum count being the center of the ROI. To choose the diameter (D) of the ROI, a Gaussian count distribution was assumed for the PS, accordingly, K=1-(0.5) D/R percent of the total PS counts was in the ROI, R being the full width at half maximum of the PS count distribution. D was set to be 6*R to enclose most (K=98.4%) of the PS counts. The count-centroid of the ROI was calculated to represent X p . The proposed method was tested in measuring the pixel size of a well-tuned SPECT, whose pixel size was estimated to be 3.02 mm according to its mechanical and electronic setting (128 x 128 matrix, 387 mm UFOV, ZOOM=1). For comparison, the original method, which was use in the former versions of some commercial SPECT software, was also tested. 12 PSs were prepared and their image acquired and stored. The net counting rate of the PSs increased from 10 cps to 1183 cps. Results: Using the proposed method, the measured pixel size (in mm) varied only between 3.00 and 3.01 (mean

  9. Optimizing the calculation of point source count-centroid in pixel size measurement

    International Nuclear Information System (INIS)

    Zhou Luyi; Kuang Anren; Su Xianyu

    2004-01-01

    Purpose: Pixel size is an important parameter of gamma camera and SPECT. A number of Methods are used for its accurate measurement. In the original count-centroid method, where the image of a point source(PS) is acquired and its count-centroid calculated to represent PS position in the image, background counts are inevitable. Thus the measured count-centroid (Xm) is an approximation of the true count-centroid (Xp) of the PS, i.e. Xm=Xp+(Xb-Xp)/(1+Rp/Rb), where Rp is the net counting rate of the PS, Xb the background count-centroid and Rb the background counting rate. To get accurate measurement, Rp must be very big, which is unpractical, resulting in the variation of measured pixel size. Rp-independent calculation of PS count-centroid is desired. Methods: The proposed method attempted to eliminate the effect of the term (Xb-Xp)/(1+Rp/Rb) by bringing Xb closer to Xp and by reducing Rb. In the acquired PS image, a circular ROI was generated to enclose the PS, the pixel with the maximum count being the center of the ROI. To choose the diameter (D) of the ROI, a Gaussian count distribution was assumed for the PS, accordingly, K=I-(0.5)D/R percent of the total PS counts was in the ROI, R being the full width at half maximum of the PS count distribution. D was set to be 6*R to enclose most (K=98.4%) of the PS counts. The count-centroid of the ROI was calculated to represent Xp. The proposed method was tested in measuring the pixel size of a well-tuned SPECT, whose pixel size was estimated to be 3.02 mm according to its mechanical and electronic setting (128*128 matrix, 387 mm UFOV, ZOOM=1). For comparison, the original method, which was use in the former versions of some commercial SPECT software, was also tested. 12 PSs were prepared and their image acquired and stored. The net counting rate of the PSs increased from 10cps to 1183cps. Results: Using the proposed method, the measured pixel size (in mm) varied only between 3.00 and 3.01( mean= 3.01±0.00) as Rp increased

  10. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de.

    1986-01-01

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied, applied to a nine heated tube bundle experimental data set. (Author) [pt

  11. Relation between medium fluid temperature and centroid subchannel temperatures of a nuclear fuel bundle mock-up

    International Nuclear Information System (INIS)

    Carvalho Tofani, P. de.

    1986-01-01

    The subchannel method used in nuclear fuel bundle thermal-hydraulic analysis lies in the statement that subchannel fluid temperatures are taken at mixed mean values. However, the development of mixing correlations and code assessment procedures are, sometimes in the literature, based upon the assumption of identity between lumped and local (subchannel centroid) temperature values. The present paper is concerned with the presentation of an approach for correlating lumped to centroid subchannel temperatures, based upon previously formulated models by the author, applied to a nine heated tube bundle experimental data set. (Author) [pt

  12. Uncertainty Quantification in Earthquake Source Characterization with Probabilistic Centroid Moment Tensor Inversion

    Science.gov (United States)

    Dettmer, J.; Benavente, R. F.; Cummins, P. R.

    2017-12-01

    This work considers probabilistic, non-linear centroid moment tensor inversion of data from earthquakes at teleseismic distances. The moment tensor is treated as deviatoric and centroid location is parametrized with fully unknown latitude, longitude, depth and time delay. The inverse problem is treated as fully non-linear in a Bayesian framework and the posterior density is estimated with interacting Markov chain Monte Carlo methods which are implemented in parallel and allow for chain interaction. The source mechanism and location, including uncertainties, are fully described by the posterior probability density and complex trade-offs between various metrics are studied. These include the percent of double couple component as well as fault orientation and the probabilistic results are compared to results from earthquake catalogs. Additional focus is on the analysis of complex events which are commonly not well described by a single point source. These events are studied by jointly inverting for multiple centroid moment tensor solutions. The optimal number of sources is estimated by the Bayesian information criterion to ensure parsimonious solutions. [Supported by NSERC.

  13. Bayesian ISOLA: new tool for automated centroid moment tensor inversion

    Science.gov (United States)

    Vackář, Jiří; Burjánek, Jan; Gallovič, František; Zahradník, Jiří; Clinton, John

    2017-04-01

    Focal mechanisms are important for understanding seismotectonics of a region, and they serve as a basic input for seismic hazard assessment. Usually, the point source approximation and the moment tensor (MT) are used. We have developed a new, fully automated tool for the centroid moment tensor (CMT) inversion in a Bayesian framework. It includes automated data retrieval, data selection where station components with various instrumental disturbances and high signal-to-noise are rejected, and full-waveform inversion in a space-time grid around a provided hypocenter. The method is innovative in the following aspects: (i) The CMT inversion is fully automated, no user interaction is required, although the details of the process can be visually inspected latter on many figures which are automatically plotted.(ii) The automated process includes detection of disturbances based on MouseTrap code, so disturbed recordings do not affect inversion.(iii) A data covariance matrix calculated from pre-event noise yields an automated weighting of the station recordings according to their noise levels and also serves as an automated frequency filter suppressing noisy frequencies.(iv) Bayesian approach is used, so not only the best solution is obtained, but also the posterior probability density function.(v) A space-time grid search effectively combined with the least-squares inversion of moment tensor components speeds up the inversion and allows to obtain more accurate results compared to stochastic methods. The method has been tested on synthetic and observed data. It has been tested by comparison with manually processed moment tensors of all events greater than M≥3 in the Swiss catalogue over 16 years using data available at the Swiss data center (http://arclink.ethz.ch). The quality of the results of the presented automated process is comparable with careful manual processing of data. The software package programmed in Python has been designed to be as versatile as possible in

  14. METHODS OF FINDING BUSINESS PARTNERS OF MANUFACTURING FIRMS IN JAPAN

    Directory of Open Access Journals (Sweden)

    Nobuhiro Takahashi

    2017-09-01

    Full Text Available This paper addresses new methods of finding business partners for joint development in Japan. These methods create opportunities for a manufacturing firm, which has excellent technology, to find an appropriate business partner. We call these methods the Osaka model. In the model, a company finds a business partner among plenty of companies, while they establish mutual trust and solve higher levels of technological difficulties. The model shares strong points of both spot transaction and conventional co-development. In other words, this model takes advantages of both Western style and Japanese style inter-business relationship. This paper also argues the environment for encouraging the model. The area should be a place where you can obtain many sources of information. Increasing meetings or facilities on specific themes is an effective method to encourage the model in the area. In addition, a database with which each technological seed has been already arranged with their technological needs is beneficial for matching them. If such a database becomes a shared knowledge in the area, the model would be promoted.

  15. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming; Wonka, Peter

    2015-01-01

    We present a novel remeshing algorithm that avoids triangles with small and triangles with large (obtuse) angles. Our solution is based on an extension to Centroidal Voronoi Tesselation (CVT). We augment the original CVT formulation by a penalty term that penalizes short Voronoi edges, while the CVT term helps to avoid small angles. Our results show significant improvements of the remeshing quality over the state of the art.

  16. Non-obtuse Remeshing with Centroidal Voronoi Tessellation

    KAUST Repository

    Yan, Dongming

    2015-12-03

    We present a novel remeshing algorithm that avoids triangles with small and triangles with large (obtuse) angles. Our solution is based on an extension to Centroidal Voronoi Tesselation (CVT). We augment the original CVT formulation by a penalty term that penalizes short Voronoi edges, while the CVT term helps to avoid small angles. Our results show significant improvements of the remeshing quality over the state of the art.

  17. Model Independent Analysis of Beam Centroid Dynamics in Accelerators

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Chun-xi

    2003-04-21

    Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map

  18. Model Independent Analysis of Beam Centroid Dynamics in Accelerators

    International Nuclear Information System (INIS)

    Wang, Chun-xi

    2003-01-01

    Fundamental issues in Beam-Position-Monitor (BPM)-based beam dynamics observations are studied in this dissertation. The major topic is the Model-Independent Analysis (MIA) of beam centroid dynamics. Conventional beam dynamics analysis requires a certain machine model, which itself of ten needs to be refined by beam measurements. Instead of using any particular machine model, MIA relies on a statistical analysis of the vast amount of BPM data that often can be collected non-invasively during normal machine operation. There are two major parts in MIA. One is noise reduction and degrees-of-freedom analysis using a singular value decomposition of a BPM-data matrix, which constitutes a principal component analysis of BPM data. The other is a physical base decomposition of the BPM-data matrix based on the time structure of pulse-by-pulse beam and/or machine parameters. The combination of these two methods allows one to break the resolution limit set by individual BPMs and observe beam dynamics at more accurate levels. A physical base decomposition is particularly useful for understanding various beam dynamics issues. MIA improves observation and analysis of beam dynamics and thus leads to better understanding and control of beams in both linacs and rings. The statistical nature of MIA makes it potentially useful in other fields. Another important topic discussed in this dissertation is the measurement of a nonlinear Poincare section (one-turn) map in circular accelerators. The beam dynamics in a ring is intrinsically nonlinear. In fact, nonlinearities are a major factor that limits stability and influences the dynamics of halos. The Poincare section map plays a basic role in characterizing and analyzing such a periodic nonlinear system. Although many kinds of nonlinear beam dynamics experiments have been conducted, no direct measurement of a nonlinear map has been reported for a ring in normal operation mode. This dissertation analyzes various issues concerning map

  19. The Single-Molecule Centroid Localization Algorithm Improves the Accuracy of Fluorescence Binding Assays.

    Science.gov (United States)

    Hua, Boyang; Wang, Yanbo; Park, Seongjin; Han, Kyu Young; Singh, Digvijay; Kim, Jin H; Cheng, Wei; Ha, Taekjip

    2018-03-13

    Here, we demonstrate that the use of the single-molecule centroid localization algorithm can improve the accuracy of fluorescence binding assays. Two major artifacts in this type of assay, i.e., nonspecific binding events and optically overlapping receptors, can be detected and corrected during analysis. The effectiveness of our method was confirmed by measuring two weak biomolecular interactions, the interaction between the B1 domain of streptococcal protein G and immunoglobulin G and the interaction between double-stranded DNA and the Cas9-RNA complex with limited sequence matches. This analysis routine requires little modification to common experimental protocols, making it readily applicable to existing data and future experiments.

  20. MOBIUS-STRIP-LIKE COLUMNAR FUNCTIONAL CONNECTIONS ARE REVEALED IN SOMATO-SENSORY RECEPTIVE FIELD CENTROIDS.

    Directory of Open Access Journals (Sweden)

    James Joseph Wright

    2014-10-01

    Full Text Available Receptive fields of neurons in the forelimb region of areas 3b and 1 of primary somatosensory cortex, in cats and monkeys, were mapped using extracellular recordings obtained sequentially from nearly radial penetrations. Locations of the field centroids indicated the presence of a functional system, in which cortical homotypic representations of the limb surfaces are entwined in three-dimensional Mobius-strip-like patterns of synaptic connections. Boundaries of somatosensory receptive field in nested groups irregularly overlie the centroid order, and are interpreted as arising from the superposition of learned connections upon the embryonic order. Since the theory of embryonic synaptic self-organisation used to model these results was devised and earlier used to explain findings in primary visual cortex, the present findings suggest the theory may be of general application throughout cortex, and may reveal a modular functional synaptic system, which, only in some parts of the cortex, and in some species, is manifest as anatomical ordering into columns.

  1. Robust EM Continual Reassessment Method in Oncology Dose Finding

    Science.gov (United States)

    Yuan, Ying; Yin, Guosheng

    2012-01-01

    The continual reassessment method (CRM) is a commonly used dose-finding design for phase I clinical trials. Practical applications of this method have been restricted by two limitations: (1) the requirement that the toxicity outcome needs to be observed shortly after the initiation of the treatment; and (2) the potential sensitivity to the prespecified toxicity probability at each dose. To overcome these limitations, we naturally treat the unobserved toxicity outcomes as missing data, and use the expectation-maximization (EM) algorithm to estimate the dose toxicity probabilities based on the incomplete data to direct dose assignment. To enhance the robustness of the design, we propose prespecifying multiple sets of toxicity probabilities, each set corresponding to an individual CRM model. We carry out these multiple CRMs in parallel, across which model selection and model averaging procedures are used to make more robust inference. We evaluate the operating characteristics of the proposed robust EM-CRM designs through simulation studies and show that the proposed methods satisfactorily resolve both limitations of the CRM. Besides improving the MTD selection percentage, the new designs dramatically shorten the duration of the trial, and are robust to the prespecification of the toxicity probabilities. PMID:22375092

  2. Modelling Perception of Structure and Affect in Music: Spectral Centroid and Wishart's Red Bird

    Directory of Open Access Journals (Sweden)

    Roger T. Dean

    2011-12-01

    Full Text Available Pearce (2011 provides a positive and interesting response to our article on time series analysis of the influences of acoustic properties on real-time perception of structure and affect in a section of Trevor Wishart’s Red Bird (Dean & Bailes, 2010. We address the following topics raised in the response and our paper. First, we analyse in depth the possible influence of spectral centroid, a timbral feature of the acoustic stream distinct from the high level general parameter we used initially, spectral flatness. We find that spectral centroid, like spectral flatness, is not a powerful predictor of real-time responses, though it does show some features that encourage its continued consideration. Second, we discuss further the issue of studying both individual responses, and as in our paper, group averaged responses. We show that a multivariate Vector Autoregression model handles the grand average series quite similarly to those of individual members of our participant groups, and we analyse this in greater detail with a wide range of approaches in work which is in press and continuing. Lastly, we discuss the nature and intent of computational modelling of cognition using acoustic and music- or information theoretic data streams as predictors, and how the music- or information theoretic approaches may be applied to electroacoustic music, which is ‘sound-based’ rather than note-centred like Western classical music.

  3. A New Scrambling Evaluation Scheme Based on Spatial Distribution Entropy and Centroid Difference of Bit-Plane

    Science.gov (United States)

    Zhao, Liang; Adhikari, Avishek; Sakurai, Kouichi

    Watermarking is one of the most effective techniques for copyright protection and information hiding. It can be applied in many fields of our society. Nowadays, some image scrambling schemes are used as one part of the watermarking algorithm to enhance the security. Therefore, how to select an image scrambling scheme and what kind of the image scrambling scheme may be used for watermarking are the key problems. Evaluation method of the image scrambling schemes can be seen as a useful test tool for showing the property or flaw of the image scrambling method. In this paper, a new scrambling evaluation system based on spatial distribution entropy and centroid difference of bit-plane is presented to obtain the scrambling degree of image scrambling schemes. Our scheme is illustrated and justified through computer simulations. The experimental results show (in Figs. 6 and 7) that for the general gray-scale image, the evaluation degree of the corresponding cipher image for the first 4 significant bit-planes selection is nearly the same as that for the 8 bit-planes selection. That is why, instead of taking 8 bit-planes of a gray-scale image, it is sufficient to take only the first 4 significant bit-planes for the experiment to find the scrambling degree. This 50% reduction in the computational cost makes our scheme efficient.

  4. Methods for Finding Legacy Wells in Large Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard W. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hodges, D. Greg [Fugro Airborne Surveys, Mississauga, ON (Canada); White, Jr., Curt M. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-16

    United States. When abandoned, many wells were not adequately sealed and now provide a potential conduit for the vertical movement of liquids and gases. Today, groundwater aquifers can be contaminated by surface pollutants flowing down wells or by deep, saline water diffusing upwards. Likewise, natural gas, carbon dioxide (CO2), or radon can travel upwards via these wells to endanger structures or human health on the surface. Recently, the need to find and plug wells has become critical with the advent of carbon dioxide injection into geologic formations for enhanced oil recovery (EOR) or carbon storage. The potential for natural gas or brine leakage through existing wells has also been raised as a concern in regions where shale resources are hydraulically fractured for hydrocarbon recovery. In this study, the National Energy Technology Laboratory (NETL) updated existing, effective well finding techniques to be able to survey large areas quickly using helicopter or ground-vehicle-mounted magnetometers, combined with mobile methane detection. For this study, magnetic data were collected using airborne and ground vehicles equipped with two boom-mounted magnetometers, or on foot using a hand-held magnetometer with a single sensor. Data processing techniques were employed to accentuate well-casing-type magnetic signatures. To locate wells with no magnetic signature (wells where the steel well casing had been removed), the team monitored for anomalous concentrations of methane, which could indicate migration of volatile compounds from deeper sedimentary strata along a well or fracture pathway. Methane measurements were obtained using the ALPIS DIfferential Absorption Lidar (DIAL) sensor for helicopter surveys and the Apogee leak detection system (LDS) for ground surveys. These methods were evaluated at a 100-year-old oilfield in Wyoming, where a helicopter magnetic survey accurately located 93% of visible wells. In addition, 20% of the wells found by the survey were

  5. Methods for Finding Legacy Wells in Large Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Hodges, D. Greg [Fugro Airborne Surveys, Mississauga, ON (Canada); White, Jr., Charles E. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-16

    More than 10 million wells have been drilled during 150 years of oil and gas production in the United States. When abandoned, many wells were not adequately sealed and now provide a potential conduit for the vertical movement of liquids and gases. Today, groundwater aquifers can be contaminated by surface pollutants flowing down wells or by deep, saline water diffusing upwards. Likewise, natural gas, carbon dioxide (CO2), or radon can travel upwards via these wells to endanger structures or human health on the surface. Recently, the need to find and plug wells has become critical with the advent of carbon dioxide injection into geologic formations for enhanced oil recovery (EOR) or carbon storage. The potential for natural gas or brine leakage through existing wells has also been raised as a concern in regions where shale resources are hydraulically fractured for hydrocarbon recovery. In this study, the National Energy Technology Laboratory (NETL) updated existing, effective well finding techniques to be able to survey large areas quickly using helicopter or ground-vehicle-mounted magnetometers, combined with mobile methane detection. For this study, magnetic data were collected using airborne and ground vehicles equipped with two boom-mounted magnetometers, or on foot using a hand-held magnetometer with a single sensor. Data processing techniques were employed to accentuate well-casing-type magnetic signatures. To locate wells with no magnetic signature (wells where the steel well casing had been removed), the team monitored for anomalous concentrations of methane, which could indicate migration of volatile compounds from deeper sedimentary strata along a well or fracture pathway. Methane measurements were obtained using the ALPIS DIfferential Absorption Lidar (DIAL) sensor for helicopter surveys and the Apogee leak detection system (LDS) for ground surveys. These methods were evaluated at a 100-year-old oilfield in Wyoming, where a helicopter magnetic

  6. User Manual and Supporting Information for Library of Codes for Centroidal Voronoi Point Placement and Associated Zeroth, First, and Second Moment Determination; TOPICAL

    International Nuclear Information System (INIS)

    BURKARDT, JOHN; GUNZBURGER, MAX; PETERSON, JANET; BRANNON, REBECCA M.

    2002-01-01

    The theory, numerical algorithm, and user documentation are provided for a new ''Centroidal Voronoi Tessellation (CVT)'' method of filling a region of space (2D or 3D) with particles at any desired particle density. ''Clumping'' is entirely avoided and the boundary is optimally resolved. This particle placement capability is needed for any so-called ''mesh-free'' method in which physical fields are discretized via arbitrary-connectivity discrete points. CVT exploits efficient statistical methods to avoid expensive generation of Voronoi diagrams. Nevertheless, if a CVT particle's Voronoi cell were to be explicitly computed, then it would have a centroid that coincides with the particle itself and a minimized rotational moment. The CVT code provides each particle's volume and centroid, and also the rotational moment matrix needed to approximate a particle by an ellipsoid (instead of a simple sphere). DIATOM region specification is supported

  7. Combined centroid-envelope dynamics of intense, magnetically focused charged beams surrounded by conducting walls

    International Nuclear Information System (INIS)

    Fiuza, K.; Rizzato, F.B.; Pakter, R.

    2006-01-01

    In this paper we analyze the combined envelope-centroid dynamics of magnetically focused high-intensity charged beams surrounded by conducting walls. Similar to the case where conducting walls are absent, it is shown that the envelope and centroid dynamics decouple from each other. Mismatched envelopes still decay into equilibrium with simultaneous emittance growth, but the centroid keeps oscillating with no appreciable energy loss. Some estimates are performed to analytically obtain characteristics of halo formation seen in the full simulations

  8. An integrating factor matrix method to find first integrals

    International Nuclear Information System (INIS)

    Saputra, K V I; Quispel, G R W; Van Veen, L

    2010-01-01

    In this paper we develop an integrating factor matrix method to derive conditions for the existence of first integrals. We use this novel method to obtain first integrals, along with the conditions for their existence, for two- and three-dimensional Lotka-Volterra systems with constant terms. The results are compared to previous results obtained by other methods.

  9. A new hierarchical method to find community structure in networks

    Science.gov (United States)

    Saoud, Bilal; Moussaoui, Abdelouahab

    2018-04-01

    Community structure is very important to understand a network which represents a context. Many community detection methods have been proposed like hierarchical methods. In our study, we propose a new hierarchical method for community detection in networks based on genetic algorithm. In this method we use genetic algorithm to split a network into two networks which maximize the modularity. Each new network represents a cluster (community). Then we repeat the splitting process until we get one node at each cluster. We use the modularity function to measure the strength of the community structure found by our method, which gives us an objective metric for choosing the number of communities into which a network should be divided. We demonstrate that our method are highly effective at discovering community structure in both computer-generated and real-world network data.

  10. EPA flow reference method testing and analysis: Findings report

    International Nuclear Information System (INIS)

    1999-06-01

    This report describes an experimental program sponsored by the US Environmental Protection Agency (EPA) to evaluate potential improvements to the Agency's current reference method for measuring volumetric flow (Method 2, 40 CFR Part 60, Appendix B). Method 2 (Determination of Stack Gas Velocity and Volumetric Flow Rate (Type S Pitot Tube)) specifies measurements to determine volumetric flow, but does not prescribe specific procedures to account for yaw or pitch angles of flow when the flow in the stack is not axial. Method 2 also allows the use of only two probe types, the Type S and the Prandtl

  11. Methods to Find the Number of Latent Skills

    Science.gov (United States)

    Beheshti, Behzad; Desmarais, Michel C.; Naceur, Rhouma

    2012-01-01

    Identifying the skills that determine the success or failure to exercises and question items is a difficult task. Multiple skills may be involved at various degree of importance, and skills may overlap and correlate. In an effort towards the goal of finding the skills behind a set of items, we investigate two techniques to determine the number of…

  12. The functional variable method for finding exact solutions of some ...

    Indian Academy of Sciences (India)

    Abstract. In this paper, we implemented the functional variable method and the modified. Riemann–Liouville derivative for the exact solitary wave solutions and periodic wave solutions of the time-fractional Klein–Gordon equation, and the time-fractional Hirota–Satsuma coupled. KdV system. This method is extremely simple ...

  13. Finding function: evaluation methods for functional genomic data

    Directory of Open Access Journals (Sweden)

    Barrett Daniel R

    2006-07-01

    Full Text Available Abstract Background Accurate evaluation of the quality of genomic or proteomic data and computational methods is vital to our ability to use them for formulating novel biological hypotheses and directing further experiments. There is currently no standard approach to evaluation in functional genomics. Our analysis of existing approaches shows that they are inconsistent and contain substantial functional biases that render the resulting evaluations misleading both quantitatively and qualitatively. These problems make it essentially impossible to compare computational methods or large-scale experimental datasets and also result in conclusions that generalize poorly in most biological applications. Results We reveal issues with current evaluation methods here and suggest new approaches to evaluation that facilitate accurate and representative characterization of genomic methods and data. Specifically, we describe a functional genomics gold standard based on curation by expert biologists and demonstrate its use as an effective means of evaluation of genomic approaches. Our evaluation framework and gold standard are freely available to the community through our website. Conclusion Proper methods for evaluating genomic data and computational approaches will determine how much we, as a community, are able to learn from the wealth of available data. We propose one possible solution to this problem here but emphasize that this topic warrants broader community discussion.

  14. An Investigation on the Use of Different Centroiding Algorithms and Star Catalogs in Astro-Geodetic Observations

    Science.gov (United States)

    Basoglu, Burak; Halicioglu, Kerem; Albayrak, Muge; Ulug, Rasit; Tevfik Ozludemir, M.; Deniz, Rasim

    2017-04-01

    In the last decade, the importance of high-precise geoid determination at local or national level has been pointed out by Turkish National Geodesy Commission. The Commission has also put objective of modernization of national height system of Turkey to the agenda. Meanwhile several projects have been realized in recent years. In Istanbul city, a GNSS/Levelling geoid was defined in 2005 for the metropolitan area of the city with an accuracy of ±3.5cm. In order to achieve a better accuracy in this area, "Local Geoid Determination with Integration of GNSS/Levelling and Astro-Geodetic Data" project has been conducted in Istanbul Technical University and Bogazici University KOERI since January 2016. The project is funded by The Scientific and Technological Research Council of Turkey. With the scope of the project, modernization studies of Digital Zenith Camera System are being carried on in terms of hardware components and software development. Accentuated subjects are the star catalogues, and centroiding algorithm used to identify the stars on the zenithal star field. During the test observations of Digital Zenith Camera System performed between 2013-2016, final results were calculated using the PSF method for star centroiding, and the second USNO CCD Astrograph Catalogue (UCAC2) for the reference star positions. This study aims to investigate the position accuracy of the star images by comparing different centroiding algorithms and available star catalogs used in astro-geodetic observations conducted with the digital zenith camera system.

  15. Publication Voting Power (PVP): method of finding Evidence-Support

    African Journals Online (AJOL)

    Background: Extracting the best evidence that support a procedure is a difficult, time consuming task that needs expert statistical knowledge. A way to make weighting evidence more simple and straight for busy clinicians is needed. Methods: The publications about the procedure under question are lined in an ascending ...

  16. Research on Language Learning Strategies: Methods, Findings, and Instructional Issues.

    Science.gov (United States)

    Oxford, Rebecca; Crookall, David

    1989-01-01

    Surveys research on formal and informal second-language learning strategies, covering the effectiveness of research methods involving making lists, interviews and thinking aloud, note-taking, diaries, surveys, and training. Suggestions for future and improved research are presented. (131 references) (CB)

  17. Functional Imaging of Autonomic Regulation: Methods and Key Findings

    Directory of Open Access Journals (Sweden)

    Paul M Macey

    2016-01-01

    Full Text Available Central nervous system processing of autonomic function involves a network of regions throughout the brain which can be visualized and measured with neuroimaging techniques, notably functional magnetic resonance imaging (fMRI. The development of fMRI procedures has both confirmed and extended earlier findings from animal models, and human stroke and lesion studies. Assessments with fMRI can elucidate interactions between different central sites in regulating normal autonomic patterning, and demonstrate how disturbed systems can interact to produce aberrant regulation during autonomic challenges. Understanding autonomic dysfunction in various illnesses reveals mechanisms that potentially lead to interventions in the impairments. The objectives here are to: 1 describe the fMRI neuroimaging methodology for assessment of autonomic neural control, 2 outline the widespread, lateralized distribution of function in autonomic sites in the normal brain which includes structures from the neocortex through the medulla and cerebellum, 3 illustrate the importance of the time course of neural changes when coordinating responses, and how those patterns are impacted in conditions of sleep-disordered breathing, and 4 highlight opportunities for future research studies with emerging methodologies. Methodological considerations specific to autonomic testing include timing of challenges relative to the underlying fMRI signal, spatial resolution sufficient to identify autonomic brainstem nuclei, blood pressure and blood oxygenation influences on the fMRI signal, and the sustained timing, often measured in minutes of challenge periods and recovery. Key findings include the lateralized nature of autonomic organization, which is reminiscent of asymmetric motor, sensory and language pathways. Testing brain function during autonomic challenges demonstrate closely-integrated timing of responses in connected brain areas during autonomic challenges, and the involvement with

  18. Method to Find Recovery Event Combinations in Probabilistic Safety Assessment

    International Nuclear Information System (INIS)

    Jung, Woo Sik; Riley, Jeff

    2016-01-01

    These research activities may develop mathematical methods, engineering analyses, and business processes. The research activities of the project covered by this scope are directed toward the specific issues of implementing the methods and strategies on a computational platform, identifying the features and enhancements to EPRI tools that would be necessary to realize significant improvements to the risk assessments performed by the end user. Fault tree analysis is extensively and successfully applied to the risk assessment of safety-critical systems such as nuclear, chemical and aerospace systems. The fault tree analysis is being used together with an event tree analysis in PSA of nuclear power plants. Fault tree solvers for a PSA are mostly based on the cutset-based algorithm. They generate minimal cut sets (MCSs) from a fault tree. The most popular fault tree solver in the PSA industry is FTREX. During the course of this project, certain technical issues (see Sections 2 to 5) have been identified that need to be addressed regarding how minimal cut sets are generated and quantified. The objective of this scope of the work was to develop new methods or techniques to address these technical limitations. By turning on all the cutset initiators (%1, %2, %3, %), all the possible minimal cut sets can be calculated easier than with the original fault tree. It is accomplished by the fact that the number of events in the minimal cut sets are significantly reduced by using cutset initiators instead of random failure events. And byy turning on a few chosen cutset initiators and turning off the other cutset initiators, minimal cut sets of the selected cutset initiator(s) can be easily calculated. As explained in the previous Sections, there is no way to calculate these minimal cut sets by turning off/on the random failure events in the original fault tree

  19. Method to Find Recovery Event Combinations in Probabilistic Safety Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Jung, Woo Sik [Sejong University, Seoul (Korea, Republic of); Riley, Jeff [Electric Power Research, Palo Alto (United States)

    2016-05-15

    These research activities may develop mathematical methods, engineering analyses, and business processes. The research activities of the project covered by this scope are directed toward the specific issues of implementing the methods and strategies on a computational platform, identifying the features and enhancements to EPRI tools that would be necessary to realize significant improvements to the risk assessments performed by the end user. Fault tree analysis is extensively and successfully applied to the risk assessment of safety-critical systems such as nuclear, chemical and aerospace systems. The fault tree analysis is being used together with an event tree analysis in PSA of nuclear power plants. Fault tree solvers for a PSA are mostly based on the cutset-based algorithm. They generate minimal cut sets (MCSs) from a fault tree. The most popular fault tree solver in the PSA industry is FTREX. During the course of this project, certain technical issues (see Sections 2 to 5) have been identified that need to be addressed regarding how minimal cut sets are generated and quantified. The objective of this scope of the work was to develop new methods or techniques to address these technical limitations. By turning on all the cutset initiators (%1, %2, %3, %), all the possible minimal cut sets can be calculated easier than with the original fault tree. It is accomplished by the fact that the number of events in the minimal cut sets are significantly reduced by using cutset initiators instead of random failure events. And byy turning on a few chosen cutset initiators and turning off the other cutset initiators, minimal cut sets of the selected cutset initiator(s) can be easily calculated. As explained in the previous Sections, there is no way to calculate these minimal cut sets by turning off/on the random failure events in the original fault tree.

  20. Findings from analysing and quantifying human error using current methods

    International Nuclear Information System (INIS)

    Dang, V.N.; Reer, B.

    1999-01-01

    In human reliability analysis (HRA), the scarcity of data means that, at best, judgement must be applied to transfer to the domain of the analysis what data are available for similar tasks. In particular for the quantification of tasks involving decisions, the analyst has to choose among quantification approaches that all depend to a significant degree on expert judgement. The use of expert judgement can be made more reliable by eliciting relative judgements rather than absolute judgements. These approaches, which are based on multiple criterion decision theory, focus on ranking the tasks to be analysed by difficulty. While these approaches remedy at least partially the poor performance of experts in the estimation of probabilities, they nevertheless require the calibration of the relative scale on which the actions are ranked in order to obtain the probabilities of interest. This paper presents some results from a comparison of some current HRA methods performed in the frame of a study of SLIM calibration options. The HRA quantification methods THERP, HEART, and INTENT were applied to derive calibration human error probabilities for two groups of operator actions. (author)

  1. Assessing Backwards Integration as a Method of KBO Family Finding

    Science.gov (United States)

    Benfell, Nathan; Ragozzine, Darin

    2018-04-01

    The age of young asteroid collisional families can sometimes be determined by using backwards n-body integrations of the solar system. This method is not used for discovering young asteroid families and is limited by the unpredictable influence of the Yarkovsky effect on individual specific asteroids over time. Since these limitations are not as important for objects in the Kuiper belt, Marcus et al. 2011 suggested that backwards integration could be used to discover and characterize collisional families in the outer solar system. But various challenges present themselves when running precise and accurate 4+ Gyr integrations of Kuiper Belt objects. We have created simulated families of Kuiper Belt Objects with identical starting locations and velocity distributions, based on the Haumea Family. We then ran several long-term test integrations to observe the effect of various simulation parameters on integration results. These integrations were then used to investigate which parameters are of enough significance to require inclusion in the integration. Thereby we determined how to construct long-term integrations that both yield significant results and require manageable processing power. Additionally, we have tested the use of backwards integration as a method of discovery of potential young families in the Kuiper Belt.

  2. Our findings, my method: Framing science in televised interviews.

    Science.gov (United States)

    Armon, Rony; Baram-Tsabari, Ayelet

    2017-11-01

    The public communication of science and technology largely depends on their framing in the news media, but scientists' role in this process has only been explored indirectly. This study focuses on storied accounts told by scientists when asked to present their research or provide expert advice in the course of a news interview. A total of 150 items from a current affairs talk show broadcast in the Israeli media were explored through a methodology combining narrative and conversation analysis. Using the concept of framing as originally proposed by Erving Goffman, we show that researchers use personal accounts as a way of reframing news stories introduced by the program hosts. Elements of method and rationale, which are usually considered technical and are shunned in journalistic reports, emerged as a crucial element in the accounts that experts themselves provided. The implications for framing research and science communication training are discussed.

  3. Finding Similarities in Ancient Ceramics by EDXRF and Multivariate Methods

    International Nuclear Information System (INIS)

    Civici, N.; Stamati, F.

    1999-01-01

    We have studied 39 samples of fragments from ceramic roof tiles with different stamps(Diamalas and Heraion), dated between 330 to 170 BC and found at the archaeological site of Dimales, some 30 km from the Adriatic coast. The data from these samples were compared with those obtained from 7 samples of similar objects and period with the stamp H eraion , found at the archaeological site of APOLLONIA. The samples were analyzed by energy-dispersive X -ray fluorescence(EDXRF), using of the x-ray lines of the elements to the intensity of the Compton peak. The results have been treated with diverse multivariate methods. The application of hierarchical cluster analysis and factor analysis permitted the identification of two main clusters. The first cluster is composed from the ''Heraion'' samples discovered in Apollonia, while the second comprises all the samples discovered in Dimale independent of their stamp. (authors)

  4. Planning Pharmacies: An Operational Method to Find the Best Location

    Directory of Open Access Journals (Sweden)

    Simona Tondelli

    2014-05-01

    Full Text Available The theme of the spatial distribution of the pharmacies on the territory is closely connected to urban planning and to services supply. In Italy, the regulatory change that took place in 2012, triggered partly by the need to adhere more to a constantly changing economic system, has led to a revision of the existing situation, consisting both on the method to quantify the pharmacies distribution and on the efficiency of the service. If Law 27/2012 has effectively allowed municipalities to increase the number of pharmacies that they can settle on the municipal territory, it has also started a process of rethinking the logic of pharmacies location and of their catchment areas. In this framework, the present paper aims to discuss the merits of a regulatory evolutions that sparked the process of liberalization of locations, integrating the law guidelines and goals with an operating logic process, usable and useful to translate goals into planning actions in a continuous dialogue between law and territory, constraints and opportunities, equity and accessibility of the care services. Following this logic operations, we have investigated the urban context of Castelfranco Emilia, assuming the location of new offices on the basis of pharmaceutical analyzes.

  5. Onychomycosis: Clinical findings, etiological agents and evaluation of laboratory methods

    Directory of Open Access Journals (Sweden)

    Dubljanin Eleonora

    2014-01-01

    Full Text Available The aim of this study was to identify the etiological agents in patients with suspected onychomycosis, and to carry out comparative testing of individual or combinations of tests: direct microscopy with KOH and Blankophor (BP, culturing on Sabouraud’s dextrose agar (SDA, diluted Sabouraud’s dextrose agar (D-SDA and dermatophyte test medium (DTM. From 70 nail samples (65 toenails, 5 fingernails, 46 (60.5% had at least one of five positive tests. Isolation was possible in 41, while in 5 samples the presence of fungi was observed by KOH and/or BP. Dermatophytes were most frequently isolated (80.5% where Trichophyton rubrum was predominant. Candida spp. was isolated in 9.8%, Aspergillus spp. 4.9%, Alternaria spp. 2.4% and Fusarium spp. 2.4%. Application of BP as an individual test was the most sensitive method. The combination of BP with DTM or D-SDA provides the best sensitivity and allows the identification of fungi to the species/genus level.

  6. Methods for Finding Legacy Wells in Residential and Commercial Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard W. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret A. [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-16

    In 1919, the enthusiasm surrounding a short-lived gas play in Versailles Borough, Pennsylvania resulted in the drilling of many needless wells. The legacy of this activity exists today in the form of abandoned, unplugged gas wells that are a continuing source of fugitive methane in the midst of a residential and commercial area. Flammable concentrations of methane have been detected near building foundations, which have forced people from their homes and businesses until methane concentrations decreased. Despite mitigation efforts, methane problems persist and have caused some buildings to be permanently abandoned and demolished. This paper describes the use of magnetic and methane sensing methods by the National Energy Technology Laboratory (NETL) to locate abandoned gas wells in Versailles Borough where site access is limited and existing infrastructure can interfere. Here, wells are located between closely spaced houses and beneath buildings and parking lots. Wells are seldom visible, often because wellheads and internal casing strings have been removed, and external casing has been cut off below ground level. The magnetic survey of Versailles Borough identified 53 strong, monopole magnetic anomalies that are presumed to indicate the locations of steel-cased wells. This hypothesis was tested by excavating the location of one strong, monopole magnetic anomaly that was within an area of anomalous methane concentrations. The excavation uncovered an unplugged gas well that was within 0.2 m of the location of the maximum magnetic signal. Truck-mounted methane surveys of Versailles Borough detected numerous methane anomalies that were useful for narrowing search areas. Methane sources identified during truck-mounted surveys included strong methane sources such as sewers and methane mitigation vents. However, inconsistent wind direction and speed, especially between buildings, made locating weaker methane sources (such as leaking wells) difficult. Walking surveys with

  7. Observations of sensor bias dependent cluster centroid shifts in a prototype sensor for the LHCb Vertex Locator detector

    CERN Document Server

    Papadelis, Aras

    2006-01-01

    We present results from a recent beam test of a prototype sensor for the LHCb Vertex Locator detector, read out with the Beetle 1.3 front-end chip. We have studied the effect of the sensor bias voltage on the reconstructed cluster positions in a sensor placed in a 120GeV pion beam at a 10° incidence angle. We find an unexplained sysematic shift in the reconstructed cluster centroid when increasing the bias voltage on an already overdepleted sensor. The shift is independent of strip pitch and sensor thickness.

  8. Peak-locking centroid bias in Shack-Hartmann wavefront sensing

    Science.gov (United States)

    Anugu, Narsireddy; Garcia, Paulo J. V.; Correia, Carlos M.

    2018-05-01

    Shack-Hartmann wavefront sensing relies on accurate spot centre measurement. Several algorithms were developed with this aim, mostly focused on precision, i.e. minimizing random errors. In the solar and extended scene community, the importance of the accuracy (bias error due to peak-locking, quantization, or sampling) of the centroid determination was identified and solutions proposed. But these solutions only allow partial bias corrections. To date, no systematic study of the bias error was conducted. This article bridges the gap by quantifying the bias error for different correlation peak-finding algorithms and types of sub-aperture images and by proposing a practical solution to minimize its effects. Four classes of sub-aperture images (point source, elongated laser guide star, crowded field, and solar extended scene) together with five types of peak-finding algorithms (1D parabola, the centre of gravity, Gaussian, 2D quadratic polynomial, and pyramid) are considered, in a variety of signal-to-noise conditions. The best performing peak-finding algorithm depends on the sub-aperture image type, but none is satisfactory to both bias and random errors. A practical solution is proposed that relies on the antisymmetric response of the bias to the sub-pixel position of the true centre. The solution decreases the bias by a factor of ˜7 to values of ≲ 0.02 pix. The computational cost is typically twice of current cross-correlation algorithms.

  9. Empirical Centroid Fictitious Play: An Approach For Distributed Learning In Multi-Agent Games

    OpenAIRE

    Swenson, Brian; Kar, Soummya; Xavier, Joao

    2013-01-01

    The paper is concerned with distributed learning in large-scale games. The well-known fictitious play (FP) algorithm is addressed, which, despite theoretical convergence results, might be impractical to implement in large-scale settings due to intense computation and communication requirements. An adaptation of the FP algorithm, designated as the empirical centroid fictitious play (ECFP), is presented. In ECFP players respond to the centroid of all players' actions rather than track and respo...

  10. Simplex-centroid mixture formulation for optimised composting of kitchen waste.

    Science.gov (United States)

    Abdullah, N; Chin, N L

    2010-11-01

    Composting is a good recycling method to fully utilise all the organic wastes present in kitchen waste due to its high nutritious matter within the waste. In this present study, the optimised mixture proportions of kitchen waste containing vegetable scraps (V), fish processing waste (F) and newspaper (N) or onion peels (O) were determined by applying the simplex-centroid mixture design method to achieve the desired initial moisture content and carbon-to-nitrogen (CN) ratio for effective composting process. The best mixture was at 48.5% V, 17.7% F and 33.7% N for blends with newspaper while for blends with onion peels, the mixture proportion was 44.0% V, 19.7% F and 36.2% O. The predicted responses from these mixture proportions fall in the acceptable limits of moisture content of 50% to 65% and CN ratio of 20-40 and were also validated experimentally. Copyright 2010 Elsevier Ltd. All rights reserved.

  11. Centroid based clustering of high throughput sequencing reads based on n-mer counts.

    Science.gov (United States)

    Solovyov, Alexander; Lipkin, W Ian

    2013-09-08

    Many problems in computational biology require alignment-free sequence comparisons. One of the common tasks involving sequence comparison is sequence clustering. Here we apply methods of alignment-free comparison (in particular, comparison using sequence composition) to the challenge of sequence clustering. We study several centroid based algorithms for clustering sequences based on word counts. Study of their performance shows that using k-means algorithm with or without the data whitening is efficient from the computational point of view. A higher clustering accuracy can be achieved using the soft expectation maximization method, whereby each sequence is attributed to each cluster with a specific probability. We implement an open source tool for alignment-free clustering. It is publicly available from github: https://github.com/luscinius/afcluster. We show the utility of alignment-free sequence clustering for high throughput sequencing analysis despite its limitations. In particular, it allows one to perform assembly with reduced resources and a minimal loss of quality. The major factor affecting performance of alignment-free read clustering is the length of the read.

  12. The effect of event shape on centroiding in photon counting detectors

    International Nuclear Information System (INIS)

    Kawakami, Hajime; Bone, David; Fordham, John; Michel, Raul

    1994-01-01

    High resolution, CCD readout, photon counting detectors employ simple centroiding algorithms for defining the spatial position of each detected event. The accuracy of centroiding is very dependent upon a number of parameters including the profile, energy and width of the intensified event. In this paper, we provide an analysis of how the characteristics of an intensified event change as the input count rate increases and the consequent effect on centroiding. The changes in these parameters are applied in particular to the MIC photon counting detector developed at UCL for ground and space based astronomical applications. This detector has a maximum format of 3072x2304 pixels permitting its use in the highest resolution applications. Individual events, at light level from 5 to 1000k events/s over the detector area, were analysed. It was found that both the asymmetry and width of event profiles were strongly dependent upon the energy of the intensified event. The variation in profile then affected the centroiding accuracy leading to loss of resolution. These inaccuracies have been quantified for two different 3 CCD pixel centroiding algorithms and one 2 pixel algorithm. The results show that a maximum error of less than 0.05 CCD pixel occurs with the 3 pixel algorithms and 0.1 CCD pixel for the 2 pixel algorithm. An improvement is proposed by utilising straight pore MCPs in the intensifier and a 70 μm air gap in front of the CCD. ((orig.))

  13. Detection of a surface breaking crack by using the centroid variations of laser ultrasonic spectrums

    International Nuclear Information System (INIS)

    Park, Seung Kyu; Baik, Sung Hoon; Lim, Chang Hwan; Joo, Young Sang; Jung, Hyun Kyu; Cha, Hyung Ki; Kang, Young June

    2006-01-01

    A laser ultrasonic system is a non-contact inspection device with a wide-band spectrum and a high spatial resolution. It provides absolute measurements of the moving distance and it can be applied to hard-to-access locations including curved or rough surfaces like in a nuclear power plant. In this paper, we have investigated the detection methods of the depth of a surface-breaking crack by using the surface wave of a laser ultrasound. The filtering function of a surface-breaking crack is a kind of a low-pass filter. The higher frequency components are more highly decreased in proportion to the crack depth. Also, the center frequency value of each ultrasound spectrum is decreased in proportion to the crack depth. We extracted the depth information of a surface-breaking crack by observing the centroid variation of the frequency spectrum. We describe the experimental results to detect the crack depth information by using the peak-to-valley values in the time domain and the center frequency values in the frequency domain.

  14. Robustness of regularities for energy centroids in the presence of random interactions

    International Nuclear Information System (INIS)

    Zhao, Y.M.; Arima, A.; Yoshida, N.; Ogawa, K.; Yoshinaga, N.; Kota, V. K. B.

    2005-01-01

    In this paper we study energy centroids such as those with fixed spin and isospin and those with fixed irreducible representations for both bosons and fermions, in the presence of random two-body and/or three-body interactions. Our results show that regularities of energy centroids of fixed-spin states reported in earlier works are very robust in these more complicated cases. We suggest that these behaviors might be intrinsic features of quantum many-body systems interacting by random forces

  15. The Global Optimal Algorithm of Reliable Path Finding Problem Based on Backtracking Method

    Directory of Open Access Journals (Sweden)

    Liang Shen

    2017-01-01

    Full Text Available There is a growing interest in finding a global optimal path in transportation networks particularly when the network suffers from unexpected disturbance. This paper studies the problem of finding a global optimal path to guarantee a given probability of arriving on time in a network with uncertainty, in which the travel time is stochastic instead of deterministic. Traditional path finding methods based on least expected travel time cannot capture the network user’s risk-taking behaviors in path finding. To overcome such limitation, the reliable path finding algorithms have been proposed but the convergence of global optimum is seldom addressed in the literature. This paper integrates the K-shortest path algorithm into Backtracking method to propose a new path finding algorithm under uncertainty. The global optimum of the proposed method can be guaranteed. Numerical examples are conducted to demonstrate the correctness and efficiency of the proposed algorithm.

  16. Text-in-context: a method for extracting findings in mixed-methods mixed research synthesis studies.

    Science.gov (United States)

    Sandelowski, Margarete; Leeman, Jennifer; Knafl, Kathleen; Crandell, Jamie L

    2013-06-01

    Our purpose in this paper is to propose a new method for extracting findings from research reports included in mixed-methods mixed research synthesis studies. International initiatives in the domains of systematic review and evidence synthesis have been focused on broadening the conceptualization of evidence, increased methodological inclusiveness and the production of evidence syntheses that will be accessible to and usable by a wider range of consumers. Initiatives in the general mixed-methods research field have been focused on developing truly integrative approaches to data analysis and interpretation. The data extraction challenges described here were encountered, and the method proposed for addressing these challenges was developed, in the first year of the ongoing (2011-2016) study: Mixed-Methods Synthesis of Research on Childhood Chronic Conditions and Family. To preserve the text-in-context of findings in research reports, we describe a method whereby findings are transformed into portable statements that anchor results to relevant information about sample, source of information, time, comparative reference point, magnitude and significance and study-specific conceptions of phenomena. The data extraction method featured here was developed specifically to accommodate mixed-methods mixed research synthesis studies conducted in nursing and other health sciences, but reviewers might find it useful in other kinds of research synthesis studies. This data extraction method itself constitutes a type of integration to preserve the methodological context of findings when statements are read individually and in comparison to each other. © 2012 Blackwell Publishing Ltd.

  17. Finger vein identification using fuzzy-based k-nearest centroid neighbor classifier

    Science.gov (United States)

    Rosdi, Bakhtiar Affendi; Jaafar, Haryati; Ramli, Dzati Athiar

    2015-02-01

    In this paper, a new approach for personal identification using finger vein image is presented. Finger vein is an emerging type of biometrics that attracts attention of researchers in biometrics area. As compared to other biometric traits such as face, fingerprint and iris, finger vein is more secured and hard to counterfeit since the features are inside the human body. So far, most of the researchers focus on how to extract robust features from the captured vein images. Not much research was conducted on the classification of the extracted features. In this paper, a new classifier called fuzzy-based k-nearest centroid neighbor (FkNCN) is applied to classify the finger vein image. The proposed FkNCN employs a surrounding rule to obtain the k-nearest centroid neighbors based on the spatial distributions of the training images and their distance to the test image. Then, the fuzzy membership function is utilized to assign the test image to the class which is frequently represented by the k-nearest centroid neighbors. Experimental evaluation using our own database which was collected from 492 fingers shows that the proposed FkNCN has better performance than the k-nearest neighbor, k-nearest-centroid neighbor and fuzzy-based-k-nearest neighbor classifiers. This shows that the proposed classifier is able to identify the finger vein image effectively.

  18. Centroid and Theoretical Rotation: Justification for Their Use in Q Methodology Research

    Science.gov (United States)

    Ramlo, Sue

    2016-01-01

    This manuscript's purpose is to introduce Q as a methodology before providing clarification about the preferred factor analytical choices of centroid and theoretical (hand) rotation. Stephenson, the creator of Q, designated that only these choices allowed for scientific exploration of subjectivity while not violating assumptions associated with…

  19. A double inequality for bounding Toader mean by the centroidal mean

    Indian Academy of Sciences (India)

    Annual Meetings · Mid Year Meetings · Discussion Meetings · Public Lectures · Lecture Workshops · Refresher Courses · Symposia · Live Streaming. Home; Journals; Proceedings – Mathematical Sciences; Volume 124; Issue 4. A double inequality for bounding Toader mean by the centroidal mean. Yun Hua Feng Qi.

  20. A double inequality for bounding Toader mean by the centroidal mean

    Indian Academy of Sciences (India)

    A double inequality for bounding Toader mean by the centroidal mean. YUN HUA1,∗ and FENG QI2. 1Department of Information Engineering, Weihai Vocational College, Weihai City,. Shandong Province 264210, China. 2College of Mathematics, Inner Mongolia University for Nationalities, Tongliao City,. Inner Mongolia ...

  1. A general centroid determination methodology, with application to multilayer dielectric structures and thermally stimulated current measurements

    International Nuclear Information System (INIS)

    Miller, S.L.; Fleetwood, D.M.; McWhorter, P.J.; Reber, R.A. Jr.; Murray, J.R.

    1993-01-01

    A general methodology is developed to experimentally characterize the spatial distribution of occupied traps in dielectric films on a semiconductor. The effects of parasitics such as leakage, charge transport through more than one interface, and interface trap charge are quantitatively addressed. Charge transport with contributions from multiple charge species is rigorously treated. The methodology is independent of the charge transport mechanism(s), and is directly applicable to multilayer dielectric structures. The centroid capacitance, rather than the centroid itself, is introduced as the fundamental quantity that permits the generic analysis of multilayer structures. In particular, the form of many equations describing stacked dielectric structures becomes independent of the number of layers comprising the stack if they are expressed in terms of the centroid capacitance and/or the flatband voltage. The experimental methodology is illustrated with an application using thermally stimulated current (TSC) measurements. The centroid of changes (via thermal emission) in the amount of trapped charge was determined for two different samples of a triple-layer dielectric structure. A direct consequence of the TSC analyses is the rigorous proof that changes in interface trap charge can contribute, though typically not significantly, to thermally stimulated current

  2. Oscillations of centroid position and surface area of soccer teams in small-sided games

    NARCIS (Netherlands)

    Frencken, Wouter; Lemmink, Koen; Delleman, Nico; Visscher, Chris

    2011-01-01

    There is a need for a collective variable that captures the dynamics of team sports like soccer at match level. The centroid positions and surface areas of two soccer teams potentially describe the coordinated flow of attacking and defending in small-sided soccer games at team level. The aim of the

  3. Finding-equal regression method and its application in predication of U resources

    International Nuclear Information System (INIS)

    Cao Huimo

    1995-03-01

    The commonly adopted deposit model method in mineral resources predication has two main part: one is model data that show up geological mineralization law for deposit, the other is statistics predication method that accords with characters of the data namely pretty regression method. This kind of regression method may be called finding-equal regression, which is made of the linear regression and distribution finding-equal method. Because distribution finding-equal method is a data pretreatment which accords with advanced mathematical precondition for the linear regression namely equal distribution theory, and this kind of data pretreatment is possible of realization. Therefore finding-equal regression not only can overcome nonlinear limitations, that are commonly occurred in traditional linear regression or other regression and always have no solution, but also can distinguish outliers and eliminate its weak influence, which would usually appeared when Robust regression possesses outlier in independent variables. Thus this newly finding-equal regression stands the best status in all kind of regression methods. Finally, two good examples of U resource quantitative predication are provided

  4. Parallel shooting methods for finding steady state solutions to engine simulation models

    DEFF Research Database (Denmark)

    Andersen, Stig Kildegård; Thomsen, Per Grove; Carlsen, Henrik

    2007-01-01

    Parallel single- and multiple shooting methods were tested for finding periodic steady state solutions to a Stirling engine model. The model was used to illustrate features of the methods and possibilities for optimisations. Performance was measured using simulation of an experimental data set...

  5. An effective method for finding special solutions of nonlinear differential equations with variable coefficients

    International Nuclear Information System (INIS)

    Qin Maochang; Fan Guihong

    2008-01-01

    There are many interesting methods can be utilized to construct special solutions of nonlinear differential equations with constant coefficients. However, most of these methods are not applicable to nonlinear differential equations with variable coefficients. A new method is presented in this Letter, which can be used to find special solutions of nonlinear differential equations with variable coefficients. This method is based on seeking appropriate Bernoulli equation corresponding to the equation studied. Many well-known equations are chosen to illustrate the application of this method

  6. AN EFFICIENT DATA MINING METHOD TO FIND FREQUENT ITEM SETS IN LARGE DATABASE USING TR- FCTM

    Directory of Open Access Journals (Sweden)

    Saravanan Suba

    2016-01-01

    Full Text Available Mining association rules in large database is one of most popular data mining techniques for business decision makers. Discovering frequent item set is the core process in association rule mining. Numerous algorithms are available in the literature to find frequent patterns. Apriori and FP-tree are the most common methods for finding frequent items. Apriori finds significant frequent items using candidate generation with more number of data base scans. FP-tree uses two database scans to find significant frequent items without using candidate generation. This proposed TR-FCTM (Transaction Reduction- Frequency Count Table Method discovers significant frequent items by generating full candidates once to form frequency count table with one database scan. Experimental results of TR-FCTM shows that this algorithm outperforms than Apriori and FP-tree.

  7. General method to find the attractors of discrete dynamic models of biological systems

    Science.gov (United States)

    Gan, Xiao; Albert, Réka

    2018-04-01

    Analyzing the long-term behaviors (attractors) of dynamic models of biological networks can provide valuable insight. We propose a general method that can find the attractors of multilevel discrete dynamical systems by extending a method that finds the attractors of a Boolean network model. The previous method is based on finding stable motifs, subgraphs whose nodes' states can stabilize on their own. We extend the framework from binary states to any finite discrete levels by creating a virtual node for each level of a multilevel node, and describing each virtual node with a quasi-Boolean function. We then create an expanded representation of the multilevel network, find multilevel stable motifs and oscillating motifs, and identify attractors by successive network reduction. In this way, we find both fixed point attractors and complex attractors. We implemented an algorithm, which we test and validate on representative synthetic networks and on published multilevel models of biological networks. Despite its primary motivation to analyze biological networks, our motif-based method is general and can be applied to any finite discrete dynamical system.

  8. General method to find the attractors of discrete dynamic models of biological systems.

    Science.gov (United States)

    Gan, Xiao; Albert, Réka

    2018-04-01

    Analyzing the long-term behaviors (attractors) of dynamic models of biological networks can provide valuable insight. We propose a general method that can find the attractors of multilevel discrete dynamical systems by extending a method that finds the attractors of a Boolean network model. The previous method is based on finding stable motifs, subgraphs whose nodes' states can stabilize on their own. We extend the framework from binary states to any finite discrete levels by creating a virtual node for each level of a multilevel node, and describing each virtual node with a quasi-Boolean function. We then create an expanded representation of the multilevel network, find multilevel stable motifs and oscillating motifs, and identify attractors by successive network reduction. In this way, we find both fixed point attractors and complex attractors. We implemented an algorithm, which we test and validate on representative synthetic networks and on published multilevel models of biological networks. Despite its primary motivation to analyze biological networks, our motif-based method is general and can be applied to any finite discrete dynamical system.

  9. Optimization of soy isoflavone extraction with different solvents using the simplex-centroid mixture design.

    Science.gov (United States)

    Yoshiara, Luciane Yuri; Madeira, Tiago Bervelieri; Delaroza, Fernanda; da Silva, Josemeyre Bonifácio; Ida, Elza Iouko

    2012-12-01

    The objective of this study was to optimize the extraction of different isoflavone forms (glycosidic, malonyl-glycosidic, aglycone and total) from defatted cotyledon soy flour using the simplex-centroid experimental design with four solvents of varying polarity (water, acetone, ethanol and acetonitrile). The obtained extracts were then analysed by high-performance liquid chromatography. The profile of the different soy isoflavones forms varied with different extractions solvents. Varying the solvent or mixture used, the extraction of different isoflavones was optimized using the centroid-simplex mixture design. The special cubic model best fitted to the four solvents and its combination for soy isoflavones extraction. For glycosidic isoflavones extraction, the polar ternary mixture (water, acetone and acetonitrile) achieved the best extraction; malonyl-glycosidic forms were better extracted with mixtures of water, acetone and ethanol. Aglycone isoflavones, water and acetone mixture were best extracted and total isoflavones, the best solvents were ternary mixture of water, acetone and ethanol.

  10. Hough transform used on the spot-centroiding algorithm for the Shack-Hartmann wavefront sensor

    Science.gov (United States)

    Chia, Chou-Min; Huang, Kuang-Yuh; Chang, Elmer

    2016-01-01

    An approach to the spot-centroiding algorithm for the Shack-Hartmann wavefront sensor (SHWS) is presented. The SHWS has a common problem, in that while measuring high-order wavefront distortion, the spots may exceed each of the subapertures, which are used to restrict the displacement of spots. This artificial restriction may limit the dynamic range of the SHWS. When using the SHWS to measure adaptive optics or aspheric lenses, the accuracy of the traditional spot-centroiding algorithm may be uncertain because the spots leave or cross the confined area of the subapertures. The proposed algorithm combines the Hough transform with an artificial neural network, which requires no confined subapertures, to increase the dynamic range of the SHWS. This algorithm is then explored in comprehensive simulations and the results are compared with those of the existing algorithm.

  11. Methods for synthesizing findings on moderation effects across multiple randomized trials.

    Science.gov (United States)

    Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

    2013-04-01

    This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design.

  12. Methods for Synthesizing Findings on Moderation Effects Across Multiple Randomized Trials

    Science.gov (United States)

    Brown, C Hendricks; Sloboda, Zili; Faggiano, Fabrizio; Teasdale, Brent; Keller, Ferdinand; Burkhart, Gregor; Vigna-Taglianti, Federica; Howe, George; Masyn, Katherine; Wang, Wei; Muthén, Bengt; Stephens, Peggy; Grey, Scott; Perrino, Tatiana

    2011-01-01

    This paper presents new methods for synthesizing results from subgroup and moderation analyses across different randomized trials. We demonstrate that such a synthesis generally results in additional power to detect significant moderation findings above what one would find in a single trial. Three general methods for conducting synthesis analyses are discussed, with two methods, integrative data analysis, and parallel analyses, sharing a large advantage over traditional methods available in meta-analysis. We present a broad class of analytic models to examine moderation effects across trials that can be used to assess their overall effect and explain sources of heterogeneity, and present ways to disentangle differences across trials due to individual differences, contextual level differences, intervention, and trial design. PMID:21360061

  13. CentroidFold: a web server for RNA secondary structure prediction

    OpenAIRE

    Sato, Kengo; Hamada, Michiaki; Asai, Kiyoshi; Mituyama, Toutai

    2009-01-01

    The CentroidFold web server (http://www.ncrna.org/centroidfold/) is a web application for RNA secondary structure prediction powered by one of the most accurate prediction engine. The server accepts two kinds of sequence data: a single RNA sequence and a multiple alignment of RNA sequences. It responses with a prediction result shown as a popular base-pair notation and a graph representation. PDF version of the graph representation is also available. For a multiple alignment sequence, the ser...

  14. A Mixed Method Research for Finding a Model of Administrative Decentralization

    OpenAIRE

    Tahereh Feizy; Alireza Moghali; Masuod Geramipoor; Reza Zare

    2015-01-01

    One of the critical issues of administrative decentralization in translating theory into practice is understanding its meaning. An important method to identify administrative decentralization is to address how it can be planned and implemented, and what are its implications, and how it would overcome challenges. The purpose of this study is finding a model for analyzing and evaluating administrative decentralization, so a mixed method research was used to explore and confirm the model of Admi...

  15. Automatic localization of the left ventricular blood pool centroid in short axis cardiac cine MR images.

    Science.gov (United States)

    Tan, Li Kuo; Liew, Yih Miin; Lim, Einly; Abdul Aziz, Yang Faridah; Chee, Kok Han; McLaughlin, Robert A

    2018-06-01

    In this paper, we develop and validate an open source, fully automatic algorithm to localize the left ventricular (LV) blood pool centroid in short axis cardiac cine MR images, enabling follow-on automated LV segmentation algorithms. The algorithm comprises four steps: (i) quantify motion to determine an initial region of interest surrounding the heart, (ii) identify potential 2D objects of interest using an intensity-based segmentation, (iii) assess contraction/expansion, circularity, and proximity to lung tissue to score all objects of interest in terms of their likelihood of constituting part of the LV, and (iv) aggregate the objects into connected groups and construct the final LV blood pool volume and centroid. This algorithm was tested against 1140 datasets from the Kaggle Second Annual Data Science Bowl, as well as 45 datasets from the STACOM 2009 Cardiac MR Left Ventricle Segmentation Challenge. Correct LV localization was confirmed in 97.3% of the datasets. The mean absolute error between the gold standard and localization centroids was 2.8 to 4.7 mm, or 12 to 22% of the average endocardial radius. Graphical abstract Fully automated localization of the left ventricular blood pool in short axis cardiac cine MR images.

  16. Error-finding and error-correcting methods for the start-up of the SLC

    International Nuclear Information System (INIS)

    Lee, M.J.; Clearwater, S.H.; Kleban, S.D.; Selig, L.J.

    1987-02-01

    During the commissioning of an accelerator, storage ring, or beam transfer line, one of the important tasks of an accelertor physicist is to check the first-order optics of the beam line and to look for errors in the system. Conceptually, it is important to distinguish between techniques for finding the machine errors that are the cause of the problem and techniques for correcting the beam errors that are the result of the machine errors. In this paper we will limit our presentation to certain applications of these two methods for finding or correcting beam-focus errors and beam-kick errors that affect the profile and trajectory of the beam respectively. Many of these methods have been used successfully in the commissioning of SLC systems. In order not to waste expensive beam time we have developed and used a beam-line simulator to test the ideas that have not been tested experimentally. To save valuable physicist's time we have further automated the beam-kick error-finding procedures by adopting methods from the field of artificial intelligence to develop a prototype expert system. Our experience with this prototype has demonstrated the usefulness of expert systems in solving accelerator control problems. The expert system is able to find the same solutions as an expert physicist but in a more systematic fashion. The methods used in these procedures and some of the recent applications will be described in this paper

  17. "Expectations to Change" ((E2C): A Participatory Method for Facilitating Stakeholder Engagement with Evaluation Findings

    Science.gov (United States)

    Adams, Adrienne E.; Nnawulezi, Nkiru A.; Vandenberg, Lela

    2015-01-01

    From a utilization-focused evaluation perspective, the success of an evaluation is rooted in the extent to which the evaluation was used by stakeholders. This paper details the "Expectations to Change" (E2C) process, an interactive, workshop-based method designed to engage primary users with their evaluation findings as a means of…

  18. Using Machine Learning Methods Jointly to Find Better Set of Rules in Data Mining

    Directory of Open Access Journals (Sweden)

    SUG Hyontai

    2017-01-01

    Full Text Available Rough set-based data mining algorithms are one of widely accepted machine learning technologies because of their strong mathematical background and capability of finding optimal rules based on given data sets only without room for prejudiced views to be inserted on the data. But, because the algorithms find rules very precisely, we may confront with the overfitting problem. On the other hand, association rule algorithms find rules of association, where the association resides between sets of items in database. The algorithms find itemsets that occur more than given minimum support, so that they can find the itemsets practically in reasonable time even for very large databases by supplying the minimum support appropriately. In order to overcome the problem of the overfitting problem in rough set-based algorithms, first we find large itemsets, after that we select attributes that cover the large itemsets. By using the selected attributes only, we may find better set of rules based on rough set theory. Results from experiments support our suggested method.

  19. Finding all solutions of nonlinear equations using the dual simplex method

    Science.gov (United States)

    Yamamura, Kiyotaka; Fujioka, Tsuyoshi

    2003-03-01

    Recently, an efficient algorithm has been proposed for finding all solutions of systems of nonlinear equations using linear programming. This algorithm is based on a simple test (termed the LP test) for nonexistence of a solution to a system of nonlinear equations using the dual simplex method. In this letter, an improved version of the LP test algorithm is proposed. By numerical examples, it is shown that the proposed algorithm could find all solutions of a system of 300 nonlinear equations in practical computation time.

  20. Establishing the soft and hard tissue area centers (centroids) for the skull and introducing a newnon-anatomical cephalometric line

    International Nuclear Information System (INIS)

    AlBalkhi, Khalid M; AlShahrani, Ibrahim; AlMadi, Abdulaziz

    2008-01-01

    The purpose of this study was to demonstrate how to establish the area center (centroid) of both the soft and hard tissues of the outline of the lateral cephalometric skull image, and to introduce the concept of a new non-anatomical centroid line. Lateral cephalometric radiographs, size 12 x 14 inch, of fifty seven adult subjects were selected based on their pleasant, balanced profile, Class I skeletal and dental relationship and no major dental malocclusion or malrelationship. The area centers (centroids) of both soft and hard tissue skull were practically established using a customized software computer program called the m -file . Connecting the two centers introduced the concept of a new non-anatomical soft and hard centroids line. (author)

  1. A Root-MUSIC-Like Direction Finding Method for Cyclostationary Signals

    Directory of Open Access Journals (Sweden)

    Yide Wang

    2005-01-01

    Full Text Available We propose a new root-MUSIC-like direction finding algorithm that exploits cyclostationarity in order to improve the direction-of-arrival estimation. The proposed cyclic method is signal selective, it allows to increase the resolution power and the noise robustness significantly, and it is also able to handle more sources than the number of sensors. Computer simulations are used to show the performance of the algorithm.

  2. Numerical form-finding method for large mesh reflectors with elastic rim trusses

    Science.gov (United States)

    Yang, Dongwu; Zhang, Yiqun; Li, Peng; Du, Jingli

    2018-06-01

    Traditional methods for designing a mesh reflector usually treat the rim truss as rigid. Due to large aperture, light weight and high accuracy requirements on spaceborne reflectors, the rim truss deformation is indeed not negligible. In order to design a cable net with asymmetric boundaries for the front and rear nets, a cable-net form-finding method is firstly introduced. Then, the form-finding method is embedded into an iterative approach for designing a mesh reflector considering the elasticity of the supporting rim truss. By iterations on form-findings of the cable-net based on the updated boundary conditions due to the rim truss deformation, a mesh reflector with a fairly uniform tension distribution in its equilibrium state could be finally designed. Applications on offset mesh reflectors with both circular and elliptical rim trusses are illustrated. The numerical results show the effectiveness of the proposed approach and that a circular rim truss is more stable than an elliptical rim truss.

  3. Search methods that people use to find owners of lost pets.

    Science.gov (United States)

    Lord, Linda K; Wittum, Thomas E; Ferketich, Amy K; Funk, Julie A; Rajala-Schultz, Päivi J

    2007-06-15

    To characterize the process by which people who find lost pets search for the owners. Cross-sectional study. Sample Population-188 individuals who found a lost pet in Dayton, Ohio, between March 1 and June 30, 2006. Procedures-Potential participants were identified as a result of contact with a local animal agency or placement of an advertisement in the local newspaper. A telephone survey was conducted to identify methods participants used to find the pets' owners. 156 of 188 (83%) individuals completed the survey. Fifty-nine of the 156 (38%) pets were reunited with their owners; median time to reunification was 2 days (range, 0.5 to 45 days). Only 1 (3%) cat owner was found, compared with 58 (46%) dog owners. Pet owners were found as a result of information provided by an animal agency (25%), placement of a newspaper advertisement (24%), walking the neighborhood (19%), signs in the neighborhood (15%), information on a pet tag (10%), and other methods (7%). Most finders (87%) considered it extremely important to find the owner, yet only 13 (8%) initially surrendered the found pet to an animal agency. The primary reason people did not surrender found pets was fear of euthanasia (57%). Only 97 (62%) individuals were aware they could run a found-pet advertisement in the newspaper at no charge, and only 1 person who was unaware of the no-charge policy placed an advertisement. Veterinarians and shelters can help educate people who find lost pets about methods to search for the pets' owners.

  4. Demonstration of biased membrane static figure mapping by optical beam subpixel centroid shift

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Fabrizio, E-mail: fpinto@jazanu.edu.sa [Laboratory for Quantum Vacuum Applications, Department of Physics, Faculty of Science, Jazan University, P.O. Box 114, Gizan 45142 (Saudi Arabia)

    2016-06-10

    The measurement of Casimir forces by means of condenser microphones has been shown to be quite promising since its early introduction almost half-a-century ago. However, unlike the remarkable progress achieved in characterizing the vibrating membrane in the dynamical case, the accurate determination of the membrane static figure under electrostatic bias remains a challenge. In this paper, we discuss our first data obtained by measuring the centroid shift of an optical beam with subpixel accuracy by charge coupled device (CCD) and by an extensive analysis of noise sources present in the experimental setup.

  5. A simple method for finding explicit analytic transition densities of diffusion processes with general diploid selection.

    Science.gov (United States)

    Song, Yun S; Steinrücken, Matthias

    2012-03-01

    The transition density function of the Wright-Fisher diffusion describes the evolution of population-wide allele frequencies over time. This function has important practical applications in population genetics, but finding an explicit formula under a general diploid selection model has remained a difficult open problem. In this article, we develop a new computational method to tackle this classic problem. Specifically, our method explicitly finds the eigenvalues and eigenfunctions of the diffusion generator associated with the Wright-Fisher diffusion with recurrent mutation and arbitrary diploid selection, thus allowing one to obtain an accurate spectral representation of the transition density function. Simplicity is one of the appealing features of our approach. Although our derivation involves somewhat advanced mathematical concepts, the resulting algorithm is quite simple and efficient, only involving standard linear algebra. Furthermore, unlike previous approaches based on perturbation, which is applicable only when the population-scaled selection coefficient is small, our method is nonperturbative and is valid for a broad range of parameter values. As a by-product of our work, we obtain the rate of convergence to the stationary distribution under mutation-selection balance.

  6. Methodically finding solutions of equipments for carrying out experiments in materials testing and research. Pt. 2

    International Nuclear Information System (INIS)

    Findeisen, D.; Nachtweide, D.; Kuntze, G.

    1983-01-01

    In comparison with the development of industrial products the development of test equipments is of special kind, which is demonstrated by methodical proceeding for finding solutions and by potentialities for technical design and production of test equipment engineering. Some general principles are turned out and explained by several realized examples of design belonging to the sphere of materials testing in den Federal Institute of Materials Testing (BAM) representative of other problems. User are large scientific institutes independent of university, scientific institutes as members of university just as test stands and quality control offices of industrial works. (orig.) [de

  7. Centroid moment tensor catalogue using a 3-D continental scale Earth model: Application to earthquakes in Papua New Guinea and the Solomon Islands

    Science.gov (United States)

    Hejrani, Babak; Tkalčić, Hrvoje; Fichtner, Andreas

    2017-07-01

    Although both earthquake mechanism and 3-D Earth structure contribute to the seismic wavefield, the latter is usually assumed to be layered in source studies, which may limit the quality of the source estimate. To overcome this limitation, we implement a method that takes advantage of a 3-D heterogeneous Earth model, recently developed for the Australasian region. We calculate centroid moment tensors (CMTs) for earthquakes in Papua New Guinea (PNG) and the Solomon Islands. Our method is based on a library of Green's functions for each source-station pair for selected Geoscience Australia and Global Seismic Network stations in the region, and distributed on a 3-D grid covering the seismicity down to 50 km depth. For the calculation of Green's functions, we utilize a spectral-element method for the solution of the seismic wave equation. Seismic moment tensors were calculated using least squares inversion, and the 3-D location of the centroid is found by grid search. Through several synthetic tests, we confirm a trade-off between the location and the correct input moment tensor components when using a 1-D Earth model to invert synthetics produced in a 3-D heterogeneous Earth. Our CMT catalogue for PNG in comparison to the global CMT shows a meaningful increase in the double-couple percentage (up to 70%). Another significant difference that we observe is in the mechanism of events with depth shallower then 15 km and Mw region.

  8. Target Centroid Position Estimation of Phase-Path Volume Kalman Filtering

    Directory of Open Access Journals (Sweden)

    Fengjun Hu

    2016-01-01

    Full Text Available For the problem of easily losing track target when obstacles appear in intelligent robot target tracking, this paper proposes a target tracking algorithm integrating reduced dimension optimal Kalman filtering algorithm based on phase-path volume integral with Camshift algorithm. After analyzing the defects of Camshift algorithm, compare the performance with the SIFT algorithm and Mean Shift algorithm, and Kalman filtering algorithm is used for fusion optimization aiming at the defects. Then aiming at the increasing amount of calculation in integrated algorithm, reduce dimension with the phase-path volume integral instead of the Gaussian integral in Kalman algorithm and reduce the number of sampling points in the filtering process without influencing the operational precision of the original algorithm. Finally set the target centroid position from the Camshift algorithm iteration as the observation value of the improved Kalman filtering algorithm to fix predictive value; thus to make optimal estimation of target centroid position and keep the target tracking so that the robot can understand the environmental scene and react in time correctly according to the changes. The experiments show that the improved algorithm proposed in this paper shows good performance in target tracking with obstructions and reduces the computational complexity of the algorithm through the dimension reduction.

  9. An automated method to find transition states using chemical dynamics simulations.

    Science.gov (United States)

    Martínez-Núñez, Emilio

    2015-02-05

    A procedure to automatically find the transition states (TSs) of a molecular system (MS) is proposed. It has two components: high-energy chemical dynamics simulations (CDS), and an algorithm that analyzes the geometries along the trajectories to find reactive pathways. Two levels of electronic structure calculations are involved: a low level (LL) is used to integrate the trajectories and also to optimize the TSs, and a higher level (HL) is used to reoptimize the structures. The method has been tested in three MSs: formaldehyde, formic acid (FA), and vinyl cyanide (VC), using MOPAC2012 and Gaussian09 to run the LL and HL calculations, respectively. Both the efficacy and efficiency of the method are very good, with around 15 TS structures optimized every 10 trajectories, which gives a total of 7, 12, and 83 TSs for formaldehyde, FA, and VC, respectively. The use of CDS makes it a powerful tool to unveil possible nonstatistical behavior of the system under study. © 2014 Wiley Periodicals, Inc.

  10. BAYESIAN DATA AUGMENTATION DOSE FINDING WITH CONTINUAL REASSESSMENT METHOD AND DELAYED TOXICITY

    Science.gov (United States)

    Liu, Suyu; Yin, Guosheng; Yuan, Ying

    2014-01-01

    A major practical impediment when implementing adaptive dose-finding designs is that the toxicity outcome used by the decision rules may not be observed shortly after the initiation of the treatment. To address this issue, we propose the data augmentation continual re-assessment method (DA-CRM) for dose finding. By naturally treating the unobserved toxicities as missing data, we show that such missing data are nonignorable in the sense that the missingness depends on the unobserved outcomes. The Bayesian data augmentation approach is used to sample both the missing data and model parameters from their posterior full conditional distributions. We evaluate the performance of the DA-CRM through extensive simulation studies, and also compare it with other existing methods. The results show that the proposed design satisfactorily resolves the issues related to late-onset toxicities and possesses desirable operating characteristics: treating patients more safely, and also selecting the maximum tolerated dose with a higher probability. The new DA-CRM is illustrated with two phase I cancer clinical trials. PMID:24707327

  11. Reducing false-positive incidental findings with ensemble genotyping and logistic regression based variant filtering methods.

    Science.gov (United States)

    Hwang, Kyu-Baek; Lee, In-Hee; Park, Jin-Ho; Hambuch, Tina; Choe, Yongjoon; Kim, MinHyeok; Lee, Kyungjoon; Song, Taemin; Neu, Matthew B; Gupta, Neha; Kohane, Isaac S; Green, Robert C; Kong, Sek Won

    2014-08-01

    As whole genome sequencing (WGS) uncovers variants associated with rare and common diseases, an immediate challenge is to minimize false-positive findings due to sequencing and variant calling errors. False positives can be reduced by combining results from orthogonal sequencing methods, but costly. Here, we present variant filtering approaches using logistic regression (LR) and ensemble genotyping to minimize false positives without sacrificing sensitivity. We evaluated the methods using paired WGS datasets of an extended family prepared using two sequencing platforms and a validated set of variants in NA12878. Using LR or ensemble genotyping based filtering, false-negative rates were significantly reduced by 1.1- to 17.8-fold at the same levels of false discovery rates (5.4% for heterozygous and 4.5% for homozygous single nucleotide variants (SNVs); 30.0% for heterozygous and 18.7% for homozygous insertions; 25.2% for heterozygous and 16.6% for homozygous deletions) compared to the filtering based on genotype quality scores. Moreover, ensemble genotyping excluded > 98% (105,080 of 107,167) of false positives while retaining > 95% (897 of 937) of true positives in de novo mutation (DNM) discovery in NA12878, and performed better than a consensus method using two sequencing platforms. Our proposed methods were effective in prioritizing phenotype-associated variants, and an ensemble genotyping would be essential to minimize false-positive DNM candidates. © 2014 WILEY PERIODICALS, INC.

  12. THE USE OF THE PATENT ANALYSIS METHOD FOR FINDING ANALOGUES AND PROTOTYPES OF RECEIVED TECHNICAL SOLUTIONS

    Directory of Open Access Journals (Sweden)

    Irina Petrova

    2016-03-01

    Full Text Available The research deals with the issue of the patent analysis efficiency, which is a necessary stage of seaching analogues and prototypes to obtain technical solutions. The article presents the results of analyzing the present automation systems for finding necessary information in the patent databases and identifies their advantages and disadvantages. It gives a description of the “Intellect” system, which is an example of software systems for the conceptual design stage support. Materials and Methods The article presents some of the possible ways to organize the patents-analogues search process and specific features of searching analogues and prototypes for the generated parametric structure scheme of the technical solution, which is the result of the synthesis of a new information-measuring and control system element in the “Intellect” system. The description of the proposed search query forming method is given. The article gives the structure of the patent passport, which must be stored in a database to organize the process of searcing analogues and prototypes. There given a description of algorithms for automatic adding a patent to the database, recalculating the weights while adding a patent by experts, identifying the fact of using different physical and technical effects in a patent. Results The final part of the article contains an example of the results of testing the developed subsystem implementing the proposed method. According to the test results it is concluded that the selected software and algorithmic solutions are effective.

  13. Component optimization of dairy manure vermicompost, straw, and peat in seedling compressed substrates using simplex-centroid design.

    Science.gov (United States)

    Yang, Longyuan; Cao, Hongliang; Yuan, Qiaoxia; Luoa, Shuai; Liu, Zhigang

    2018-03-01

    Vermicomposting is a promising method to disposal dairy manures, and the dairy manure vermicompost (DMV) to replace expensive peat is of high value in the application of seedling compressed substrates. In this research, three main components: DMV, straw, and peat, are conducted in the compressed substrates, and the effect of individual components and the corresponding optimal ratio for the seedling production are significant. To address these issues, the simplex-centroid experimental mixture design is employed, and the cucumber seedling experiment is conducted to evaluate the compressed substrates. Results demonstrated that the mechanical strength and physicochemical properties of compressed substrates for cucumber seedling can be well satisfied with suitable mixture ratio of the components. Moreover, DMV, straw, and peat) could be determined at 0.5917:0.1608:0.2475 when the weight coefficients of the three parameters (shoot length, root dry weight, and aboveground dry weight) were 1:1:1. For different purpose, the optimum ratio can be little changed on the basis of different weight coefficients. Compressed substrate is lump and has certain mechanical strength, produced by application of mechanical pressure to the seedling substrates. It will not harm seedlings when bedding out the seedlings, since the compressed substrate and seedling are bedded out together. However, there is no one using the vermicompost and agricultural waste components of compressed substrate for vegetable seedling production before. Thus, it is important to understand the effect of individual components to seedling production, and to determine the optimal ratio of components.

  14. Electrocution of Raptors on Power Lines: A Review of Necropsy Methods and Findings.

    Science.gov (United States)

    Kagan, R A

    2016-09-01

    Decades after the problem was first identified, power line electrocution continues to be a cause of avian mortality. Currently, several federal laws protect eagles and other migratory birds, meaning that utility companies may be liable for electrocution-related deaths. Veterinarians and veterinary pathologists called upon to diagnose and treat electrocuted birds should keep this in mind when conducting clinical and postmortem examinations. This review details necropsy findings and methods used to diagnose electrocution. A combination of gross, subgross, and radiographic examinations can aid in identification of subtle injury. Diagnosis is made based on the presence of skin and/or feather burns. Other necropsy findings may include skin lacerations, subcutaneous burns, bruising, limb avulsion, hemopericardium, and vascular rupture. At the US Fish and Wildlife Service's National Forensics Laboratory, from 2000 to 2015, 417 raptor deaths were determined to have been caused by electrocution. Bald eagles and golden eagles were the most commonly submitted species. In a retrospective review of 377 cases, for which whole bodies were submitted, 18% of the electrocuted birds had only a single, small (less than 3 cm in diameter) external burn. Small, isolated burns tended to occur on the undersides of the wings at and distal to the elbow and on the lower legs and feet. These areas should be most carefully examined in cases where electrocution injury is not immediately apparent. © The Author(s) 2016.

  15. School Locations and Traffic Emissions — Environmental (InJustice Findings Using a New Screening Method

    Directory of Open Access Journals (Sweden)

    Philine Gaffron

    2015-02-01

    Full Text Available It has been shown that the location of schools near heavily trafficked roads can have detrimental effects on the health of children attending those schools. It is therefore desirable to screen both existing school locations and potential new school sites to assess either the need for remedial measures or suitability for the intended use. Current screening tools and public guidance on school siting are either too coarse in their spatial resolution for assessing individual sites or are highly resource intensive in their execution (e.g., through dispersion modeling. We propose a new method to help bridge the gap between these two approaches. Using this method, we also examine the public K-12 schools in the Sacramento Area Council of Governments Region, California (USA from an environmental justice perspective. We find that PM2.5 emissions from road traffic affecting a school site are significantly positively correlated with the following metrics: percent share of Black, Hispanic and multi-ethnic students, percent share of students eligible for subsidized meals. The emissions metric correlates negatively with the schools’ Academic Performance Index, the share of White students and average parental education levels. Our PM2.5 metric also correlates with the traffic related, census tract level screening indicators from the California Communities Environmental Health Screening Tool and the tool’s tract level rate of asthma related emergency department visits.

  16. Path integral centroid molecular dynamics simulations of semiinfinite slab and bulk liquid of para-hydrogen

    Energy Technology Data Exchange (ETDEWEB)

    Kinugawa, Kenichi [Nara Women`s Univ., Nara (Japan). Dept. of Chemistry

    1998-10-01

    It has been unsuccessful to solve a set of time-dependent Schroedinger equations numerically for many-body quantum systems which involve, e.g., a number of hydrogen molecules, protons, and excess electrons at a low temperature, where quantum effect evidently appears. This undesirable situation is fatal for the investigation of real low-temperature chemical systems because they are essentially composed of many quantum degrees of freedom. However, if we use a new technique called `path integral centroid molecular dynamics (CMD) simulation` proposed by Cao and Voth in 1994, the real-time semi-classical dynamics of many degrees of freedom can be computed by utilizing the techniques already developed in the traditional classical molecular dynamics (MD) simulations. Therefore, the CMD simulation is expected to be very powerful tool for the quantum dynamics studies or real substances. (J.P.N.)

  17. Acquisition and Initial Analysis of H+- and H--Beam Centroid Jitter at LANSCE

    Science.gov (United States)

    Gilpatrick, J. D.; Bitteker, L.; Gulley, M. S.; Kerstiens, D.; Oothoudt, M.; Pillai, C.; Power, J.; Shelley, F.

    2006-11-01

    During the 2005 Los Alamos Neutron Science Center (LANSCE) beam runs, beam current and centroid-jitter data were observed, acquired, analyzed, and documented for both the LANSCE H+ and H- beams. These data were acquired using three beam position monitors (BPMs) from the 100-MeV Isotope Production Facility (IPF) beam line and three BPMs from the Switchyard transport line at the end of the LANSCE 800-MeV linac. The two types of data acquired, intermacropulse and intramacropulse, were analyzed for statistical and frequency characteristics as well as various other correlations including comparing their phase-space like characteristics in a coordinate system of transverse angle versus transverse position. This paper will briefly describe the measurements required to acquire these data, the initial analysis of these jitter data, and some interesting dilemmas these data presented.

  18. The centroidal algorithm in molecular similarity and diversity calculations on confidential datasets

    Science.gov (United States)

    Trepalin, Sergey; Osadchiy, Nikolay

    2005-09-01

    Chemical structure provides exhaustive description of a compound, but it is often proprietary and thus an impediment in the exchange of information. For example, structure disclosure is often needed for the selection of most similar or dissimilar compounds. Authors propose a centroidal algorithm based on structural fragments (screens) that can be efficiently used for the similarity and diversity selections without disclosing structures from the reference set. For an increased security purposes, authors recommend that such set contains at least some tens of structures. Analysis of reverse engineering feasibility showed that the problem difficulty grows with decrease of the screen's radius. The algorithm is illustrated with concrete calculations on known steroidal, quinoline, and quinazoline drugs. We also investigate a problem of scaffold identification in combinatorial library dataset. The results show that relatively small screens of radius equal to 2 bond lengths perform well in the similarity sorting, while radius 4 screens yield better results in diversity sorting. The software implementation of the algorithm taking SDF file with a reference set generates screens of various radii which are subsequently used for the similarity and diversity sorting of external SDFs. Since the reverse engineering of the reference set molecules from their screens has the same difficulty as the RSA asymmetric encryption algorithm, generated screens can be stored openly without further encryption. This approach ensures an end user transfers only a set of structural fragments and no other data. Like other algorithms of encryption, the centroid algorithm cannot give 100% guarantee of protecting a chemical structure from dataset, but probability of initial structure identification is very small-order of 10-40 in typical cases.

  19. Bayesian inference and interpretation of centroid moment tensors of the 2016 Kumamoto earthquake sequence, Kyushu, Japan

    Science.gov (United States)

    Hallo, Miroslav; Asano, Kimiyuki; Gallovič, František

    2017-09-01

    On April 16, 2016, Kumamoto prefecture in Kyushu region, Japan, was devastated by a shallow M JMA7.3 earthquake. The series of foreshocks started by M JMA6.5 foreshock 28 h before the mainshock. They have originated in Hinagu fault zone intersecting the mainshock Futagawa fault zone; hence, the tectonic background for this earthquake sequence is rather complex. Here we infer centroid moment tensors (CMTs) for 11 events with M JMA between 4.8 and 6.5, using strong motion records of the K-NET, KiK-net and F-net networks. We use upgraded Bayesian full-waveform inversion code ISOLA-ObsPy, which takes into account uncertainty of the velocity model. Such an approach allows us to reliably assess uncertainty of the CMT parameters including the centroid position. The solutions show significant systematic spatial and temporal variations throughout the sequence. Foreshocks are right-lateral steeply dipping strike-slip events connected to the NE-SW shear zone. Those located close to the intersection of the Hinagu and Futagawa fault zones are dipping slightly to ESE, while those in the southern area are dipping to WNW. Contrarily, aftershocks are mostly normal dip-slip events, being related to the N-S extensional tectonic regime. Most of the deviatoric moment tensors contain only minor CLVD component, which can be attributed to the velocity model uncertainty. Nevertheless, two of the CMTs involve a significant CLVD component, which may reflect complex rupture process. Decomposition of those moment tensors into two pure shear moment tensors suggests combined right-lateral strike-slip and normal dip-slip mechanisms, consistent with the tectonic settings of the intersection of the Hinagu and Futagawa fault zones.[Figure not available: see fulltext.

  20. A Proposal to Speed up the Computation of the Centroid of an Interval Type-2 Fuzzy Set

    Directory of Open Access Journals (Sweden)

    Carlos E. Celemin

    2013-01-01

    Full Text Available This paper presents two new algorithms that speed up the centroid computation of an interval type-2 fuzzy set. The algorithms include precomputation of the main operations and initialization based on the concept of uncertainty bounds. Simulations over different kinds of footprints of uncertainty reveal that the new algorithms achieve computation time reductions with respect to the Enhanced-Karnik algorithm, ranging from 40 to 70%. The results suggest that the initialization used in the new algorithms effectively reduces the number of iterations to compute the extreme points of the interval centroid while precomputation reduces the computational cost of each iteration.

  1. The Dietary Patterns Methods Project: Synthesis of Findings across Cohorts and Relevance to Dietary Guidance1234

    Science.gov (United States)

    Liese, Angela D; Krebs-Smith, Susan M; Subar, Amy F; George, Stephanie M; Harmon, Brook E; Neuhouser, Marian L; Boushey, Carol J; Schap, TusaRebecca E; Reedy, Jill

    2015-01-01

    The Dietary Patterns Methods Project (DPMP) was initiated in 2012 to strengthen research evidence on dietary indices, dietary patterns, and health for upcoming revisions of the Dietary Guidelines for Americans, given that the lack of consistent methodology has impeded development of consistent and reliable conclusions. DPMP investigators developed research questions and a standardized approach to index-based dietary analysis. This article presents a synthesis of findings across the cohorts. Standardized analyses were conducted in the NIH-AARP Diet and Health Study, the Multiethnic Cohort, and the Women’s Health Initiative Observational Study (WHI-OS). Healthy Eating Index 2010, Alternative Healthy Eating Index 2010 (AHEI-2010), alternate Mediterranean Diet, and Dietary Approaches to Stop Hypertension (DASH) scores were examined across cohorts for correlations between pairs of indices; concordant classifications into index score quintiles; associations with all-cause, cardiovascular disease (CVD), and cancer mortality with the use of Cox proportional hazards models; and dietary intake of foods and nutrients corresponding to index quintiles. Across all cohorts in women and men, there was a high degree of correlation and consistent classifications between index pairs. Higher diet quality (top quintile) was significantly and consistently associated with an 11–28% reduced risk of death due to all causes, CVD, and cancer compared with the lowest quintile, independent of known confounders. This was true for all diet index–mortality associations, with the exception of AHEI-2010 and cancer mortality in WHI-OS women. In all cohorts, survival benefit was greater with a higher-quality diet, and relatively small intake differences distinguished the index quintiles. The reductions in mortality risk started at relatively lower levels of diet quality. Higher scores on each of the indices, signifying higher diet quality, were associated with marked reductions in mortality

  2. Old Wine in New Skins: The Sensitivity of Established Findings to New Methods

    Science.gov (United States)

    Foster, E. Michael; Wiley-Exley, Elizabeth; Bickman, Leonard

    2009-01-01

    Findings from an evaluation of a model system for delivering mental health services to youth were reassessed to determine the robustness of key findings to the use of methodologies unavailable to the original analysts. These analyses address a key concern about earlier findings--that the quasi-experimental design involved the comparison of two…

  3. Cooling as a method of finding topological dislocations in lattice models

    International Nuclear Information System (INIS)

    Gomberoff, K.

    1989-01-01

    It is well known that the O(3) two-dimensional model has configurations with topological charge Q=1 and action S/sub min/=6.69. Since the exponent characterizing the renormalization-group behavior of this model is 4π such configurations invalidate the standard scaling behavior of the topological susceptibility. The analog exponent for the four-dimensional lattice SU(2) gauge model is 10.77. If there would exist configurations with Q=1 and S<10.77 in this model, they would invalidate the standard scaling behavior of its topological susceptibility. Kremer et al. have calculated the action of different configurations during cooling runs. They report that they do not find any configuration with S<12.7 and Q=1. I show that in the O(3) two-dimensional model cooling runs fail to uncover the well-known configurations with S<8. We conclude that the cooling method is not effective in uncovering the smallest action configurations in the Q=1 sector

  4. Novel method of finding extreme edges in a convex set of N-dimension vectors

    Science.gov (United States)

    Hu, Chia-Lun J.

    2001-11-01

    As we published in the last few years, for a binary neural network pattern recognition system to learn a given mapping {Um mapped to Vm, m=1 to M} where um is an N- dimension analog (pattern) vector, Vm is a P-bit binary (classification) vector, the if-and-only-if (IFF) condition that this network can learn this mapping is that each i-set in {Ymi, m=1 to M} (where Ymithere existsVmiUm and Vmi=+1 or -1, is the i-th bit of VR-m).)(i=1 to P and there are P sets included here.) Is POSITIVELY, LINEARLY, INDEPENDENT or PLI. We have shown that this PLI condition is MORE GENERAL than the convexity condition applied to a set of N-vectors. In the design of old learning machines, we know that if a set of N-dimension analog vectors form a convex set, and if the machine can learn the boundary vectors (or extreme edges) of this set, then it can definitely learn the inside vectors contained in this POLYHEDRON CONE. This paper reports a new method and new algorithm to find the boundary vectors of a convex set of ND analog vectors.

  5. A Novel Approach Based on MEMS-Gyro's Data Deep Coupling for Determining the Centroid of Star Spot

    Directory of Open Access Journals (Sweden)

    Xing Fei

    2012-01-01

    Full Text Available The traditional approach of star tracker for determining the centroid of spot requires enough energy and good shape, so a relatively long exposure time and stable three-axis state become necessary conditions to maintain high accuracy, these limit its update rate and dynamic performance. In view of these issues, this paper presents an approach for determining the centroid of star spot which based on MEMS-Gyro's data deep coupling, it achieves the deep fusion of the data of star tracker and MEMS-Gyro at star map level through the introduction of EKF. The trajectory predicted by using the angular velocity of three axes can be used to set the extraction window, this enhances the dynamic performance because of the accurate extraction when the satellite has angular speed. The optimal estimations of the centroid position and the drift in the output signal of MEMS-Gyro through this approach reduce the influence of noise of the detector on accuracy of the traditional approach for determining the centroid and effectively correct the output signal of MEMS-Gyro. At the end of this paper, feasibility of this approach is verified by simulation.

  6. Infant feeding experiences among teen mothers in North Carolina: Findings from a mixed-methods study

    Directory of Open Access Journals (Sweden)

    Samandari Ghazaleh

    2011-09-01

    Full Text Available Abstract Background Adolescent mothers in the U.S. are much less likely to initiate breastfeeding than older mothers, and teens who do initiate breastfeeding tend to breastfeed for shorter durations. The purpose of this mixed-methods study is to investigate breastfeeding practices, barriers and facilitators among adolescent mothers ages 17 and younger. Methods Quantitative descriptive analyses are conducted using data from the North Carolina Pregnancy Risk Assessment Monitoring System (PRAMS. The population-based sample comprises 389 teens ages 13-17 giving birth to a live born infant in North Carolina in 2000 - 2005 and in 2007. Qualitative analyses are based on in-depth interviews with 22 Black, White and Hispanic teen mothers residing in rural and urban areas of North Carolina conducted between November 2007 and February 2009. Results In quantitative analyses, 52% (196 of 389 of North Carolina teen mothers initiated breastfeeding, but half of those who initiated breastfeeding (92/196 stopped within the first month postpartum. Hispanic teens (44/52 or 89% were much more likely than Black (61/159 or 41% or White teens (87/164 or 52% to initiate breastfeeding and to continue for a longer duration. Nearly sixty two percent (29/52 of Hispanic respondents breastfed for greater than four weeks as compared to 16% (29/159 of Black respondents and 26% (39/164 of White respondents. Common barriers to breastfeeding initiation and continuation included not liking breastfeeding, returning to school, nipple pain, and insufficient milk. Qualitative data provided context for the quantitative findings, elucidating the barriers and facilitators to breastfeeding from the teens' perspective and insight into the ways in which breastfeeding support to teens could be enhanced. Conclusions The large number of adolescents ceasing breastfeeding within the first month points to the need for more individualized follow-up after hospital discharge in the first few days

  7. Interprofessional teamwork in comprehensive primary healthcare services: Findings from a mixed methods study.

    Science.gov (United States)

    Bentley, Michael; Freeman, Toby; Baum, Fran; Javanparast, Sara

    2018-05-01

    This article draws on data from a 5-year project that examined the effectiveness of Comprehensive primary healthcare (CPHC) in local communities. A hallmark of CPHC services is interprofessional teamwork. Drawing from this study, our article presents factors that enabled, or hindered, healthcare teams working interprofessionally in Australian primary healthcare (PHC) services. The article reports on the experiences of teams working in six Australian PHC services (four managed by state governments, one non-government sexual health organisation, and one Aboriginal community-controlled health service) during a time of significant health sector restructure. Findings are drawn from two key methods: an online survey of practitioners and managers (n = 154), and interviews with managers and practitioners (n = 60) from the six study sites. The majority of survey respondents worked with other health professionals in their service to provide interprofessional care to clients. Processes included formal team meetings, case conferencing, referring clients to other health professionals if needed, informal communication with other health professionals about clients, and team-based delivery of care. A range of interrelated factors affected interprofessional work at the services, from contextual, organisational, processual, and relational domains. Funding cuts and policy changes that saw a reorientation and re-medicalisation of South Australian services undermined interprofessional work, while a shared CPHC culture and commitment among some staff was helpful in resisting some of these effects. The co-location of services was a factor in PHC teams working interprofessionally and not only enabled some PHC teams to work more interprofessionally but also created barriers to interprofessional teamwork through disruption resulting from restructuring of services. Our study indicates the importance of decision makers taking into account the potential effects of policy and structural

  8. Reconciling incongruous qualitative and quantitative findings in mixed methods research: exemplars from research with drug using populations.

    Science.gov (United States)

    Wagner, Karla D; Davidson, Peter J; Pollini, Robin A; Strathdee, Steffanie A; Washburn, Rachel; Palinkas, Lawrence A

    2012-01-01

    Mixed methods research is increasingly being promoted in the health sciences as a way to gain more comprehensive understandings of how social processes and individual behaviours shape human health. Mixed methods research most commonly combines qualitative and quantitative data collection and analysis strategies. Often, integrating findings from multiple methods is assumed to confirm or validate the findings from one method with the findings from another, seeking convergence or agreement between methods. Cases in which findings from different methods are congruous are generally thought of as ideal, whilst conflicting findings may, at first glance, appear problematic. However, the latter situation provides the opportunity for a process through which apparently discordant results are reconciled, potentially leading to new emergent understandings of complex social phenomena. This paper presents three case studies drawn from the authors' research on HIV risk amongst injection drug users in which mixed methods studies yielded apparently discrepant results. We use these case studies (involving injection drug users [IDUs] using a Needle/Syringe Exchange Program in Los Angeles, CA, USA; IDUs seeking to purchase needle/syringes at pharmacies in Tijuana, Mexico; and young street-based IDUs in San Francisco, CA, USA) to identify challenges associated with integrating findings from mixed methods projects, summarize lessons learned, and make recommendations for how to more successfully anticipate and manage the integration of findings. Despite the challenges inherent in reconciling apparently conflicting findings from qualitative and quantitative approaches, in keeping with others who have argued in favour of integrating mixed methods findings, we contend that such an undertaking has the potential to yield benefits that emerge only through the struggle to reconcile discrepant results and may provide a sum that is greater than the individual qualitative and quantitative parts

  9. Findings, theories and methods in the study of children's national identifications and national attitudes

    NARCIS (Netherlands)

    Barrett, M.; Oppenheimer, L.

    2011-01-01

    This paper reviews some of the relevant background findings against which the empirical studies reported in this special issue were designed. Particular attention is given to previous findings on the development of children’s national knowledge, national attitudes and national identifications. The

  10. Quality of life in child and adolescent illness: concepts, methods, and findings

    National Research Council Canada - National Science Library

    Koot, Hans M; Wallander, Jan Lance

    2001-01-01

    ... and Findings Edited by Hans M. Koot Erasmus University Rotterdam, The Netherlands and Jan L. Wallander University of Alabama, Birmingham, USA I ~ ~~o~~~n~~~up LONDON...

  11. A path method for finding energy barriers and minimum energy paths in complex micromagnetic systems

    International Nuclear Information System (INIS)

    Dittrich, R.; Schrefl, T.; Suess, D.; Scholz, W.; Forster, H.; Fidler, J.

    2002-01-01

    Minimum energy paths and energy barriers are calculated for complex micromagnetic systems. The method is based on the nudged elastic band method and uses finite-element techniques to represent granular structures. The method was found to be robust and fast for both simple test problems as well as for large systems such as patterned granular media. The method is used to estimate the energy barriers in CoCr-based perpendicular recording media

  12. Kepler Planet Detection Metrics: Automatic Detection of Background Objects Using the Centroid Robovetter

    Science.gov (United States)

    Mullally, Fergal

    2017-01-01

    We present an automated method of identifying background eclipsing binaries masquerading as planet candidates in the Kepler planet candidate catalogs. We codify the manual vetting process for Kepler Objects of Interest (KOIs) described in Bryson et al. (2013) with a series of measurements and tests that can be performed algorithmically. We compare our automated results with a sample of manually vetted KOIs from the catalog of Burke et al. (2014) and find excellent agreement. We test the performance on a set of simulated transits and find our algorithm correctly identifies simulated false positives approximately 50 of the time, and correctly identifies 99 of simulated planet candidates.

  13. Decadal Western Pacific Warm Pool Variability: A Centroid and Heat Content Study.

    Science.gov (United States)

    Kidwell, Autumn; Han, Lu; Jo, Young-Heon; Yan, Xiao-Hai

    2017-10-13

    We examine several characteristics of the Western Pacific Warm Pool (WP) in the past thirty years of mixed interannual variability and climate change. Our study presents the three-dimensional WP centroid (WPC) movement, WP heat content anomaly (HC) and WP volume (WPV) on interannual to decadal time scales. We show the statistically significant correlation between each parameter's interannual anomaly and the NINO 3, NINO 3.4, NINO 4, SOI, and PDO indices. The longitudinal component of the WPC is most strongly correlated with NINO 4 (R = 0.78). The depth component of the WPC has the highest correlation (R = -0.6) with NINO3.4. The WPV and NINO4 have an R-Value of -0.65. HC has the highest correlation with NINO3.4 (R = -0.52). During the study period of 1982-2014, the non-linear trends, derived from ensemble empirical mode decomposition (EEMD), show that the WPV, WP depth and HC have all increased. The WPV has increased by 14% since 1982 and the HC has increased from -1 × 10 8  J/m 2 in 1993 to 10 × 10 8  J/m 2 in 2014. While the largest variances in the latitudinal and longitudinal WPC locations are associated with annual and seasonal timescales, the largest variances in the WPV and HC are due to the multi-decadal non-linear trend.

  14. Power centroid radar and its rise from the universal cybernetics duality

    Science.gov (United States)

    Feria, Erlan H.

    2014-05-01

    Power centroid radar (PC-Radar) is a fast and powerful adaptive radar scheme that naturally surfaced from the recent discovery of the time-dual for information theory which has been named "latency theory." Latency theory itself was born from the universal cybernetics duality (UC-Duality), first identified in the late 1970s, that has also delivered a time dual for thermodynamics that has been named "lingerdynamics" and anchors an emerging lifespan theory for biological systems. In this paper the rise of PC-Radar from the UC-Duality is described. The development of PC-Radar, US patented, started with Defense Advanced Research Projects Agency (DARPA) funded research on knowledge-aided (KA) adaptive radar of the last decade. The outstanding signal to interference plus noise ratio (SINR) performance of PC-Radar under severely taxing environmental disturbances will be established. More specifically, it will be seen that the SINR performance of PC-Radar, either KA or knowledgeunaided (KU), approximates that of an optimum KA radar scheme. The explanation for this remarkable result is that PC-Radar inherently arises from the UC-Duality, which advances a "first principles" duality guidance theory for the derivation of synergistic storage-space/computational-time compression solutions. Real-world synthetic aperture radar (SAR) images will be used as prior-knowledge to illustrate these results.

  15. Collective centroid oscillations as an emittance preservation diagnostic in linear collider linacs

    International Nuclear Information System (INIS)

    Adolphsen, C.E.; Bane, K.L.F.; Spence, W.L.; Woodley, M.D.

    1997-08-01

    Transverse bunch centroid oscillations, induced at operating beam currents at which transverse wakefields are substantial, and observed at Beam Position Monitors, are sensitive to the actual magnetic focusing, energy gain, and rf phase profiles in a linac, and are insensitive to misalignments and jitter sources. In the pulse stealing set-up implemented at the SLC, they thus allow the frequent monitoring of the stability of the in-place emittance growth inhibiting or mitigating measures--primarily the energy scaled magnetic lattice and the rf phases necessary for BNS damping--independent of the actual emittance growth as driven by misalignments and jitter. The authors have developed a physically based analysis technique to meaningfully reduce the data. Oscillation beta-beating is a primary indicator of beam energy errors; shifts in the invariant amplitude reflect differential internal motion along the longitudinally extended bunch and thus are a sensitive indicator of the real rf phases in the machine; shifts in betatron phase advance contain corroborative information sensitive to both effects

  16. The Expanded FindCore Method for Identification of a Core Atom Set for Assessment of Protein Structure Prediction

    Science.gov (United States)

    Snyder, David A.; Grullon, Jennifer; Huang, Yuanpeng J.; Tejero, Roberto; Montelione, Gaetano T.

    2014-01-01

    Maximizing the scientific impact of NMR-based structure determination requires robust and statistically sound methods for assessing the precision of NMR-derived structures. In particular, a method to define a core atom set for calculating superimpositions and validating structure predictions is critical to the use of NMR-derived structures as targets in the CASP competition. FindCore (D.A. Snyder and G.T. Montelione PROTEINS 2005;59:673–686) is a superimposition independent method for identifying a core atom set, and partitioning that set into domains. However, as FindCore optimizes superimposition by sensitively excluding not-well-defined atoms, the FindCore core may not comprise all atoms suitable for use in certain applications of NMR structures, including the CASP assessment process. Adapting the FindCore approach to assess predicted models against experimental NMR structures in CASP10 required modification of the FindCore method. This paper describes conventions and a standard protocol to calculate an “Expanded FindCore” atom set suitable for validation and application in biological and biophysical contexts. A key application of the Expanded FindCore method is to identify a core set of atoms in the experimental NMR structure for which it makes sense to validate predicted protein structure models. We demonstrate the application of this Expanded FindCore method in characterizing well-defined regions of 18 NMR-derived CASP10 target structures. The Expanded FindCore protocol defines “expanded core atom sets” that match an expert’s intuition of which parts of the structure are sufficiently well-defined to use in assessing CASP model predictions. We also illustrate the impact of this analysis on the CASP GDT assessment scores. PMID:24327305

  17. Finding ultracool brown dwarfs with MegaCam on CFHT: method and first results

    Science.gov (United States)

    Delorme, P.; Willott, C. J.; Forveille, T.; Delfosse, X.; Reylé, C.; Bertin, E.; Albert, L.; Artigau, E.; Robin, A. C.; Allard, F.; Doyon, R.; Hill, G. J.

    2008-06-01

    Aims: We present the first results of a wide field survey for cool brown dwarfs with the MegaCam camera on the CFHT telescope, the Canada-France Brown Dwarf Survey, hereafter CFBDS. Our objectives are to find ultracool brown dwarfs and to constrain the field-brown dwarf mass function thanks to a larger sample of L and T dwarfs. Methods: We identify candidates in CFHT/MegaCam i' and z' images using optimised psf-fitting within Source Extractor, and follow them up with pointed near-infrared imaging on several telescopes. Results: We have so far analysed over 350 square degrees and found 770 brown dwarf candidates brighter than z'_AB=22.5. We currently have J-band photometry for 220 of these candidates, which confirms 37% as potential L or T dwarfs. Some are among the reddest and farthest brown dwarfs currently known, including an independent identification of the recently published ULAS J003402.77-005206.7 and the discovery of a second brown dwarf later than T8, CFBDS J005910.83-011401.3. Infrared spectra of three T dwarf candidates confirm their nature, and validate the selection process. Conclusions: The completed survey will discover ~100 T dwarfs and ~500 L dwarfs or M dwarfs later than M8, approximately doubling the number of currently known brown dwarfs. The resulting sample will have a very well-defined selection function, and will therefore produce a very clean luminosity function. Based on observations obtained with MegaPrime/MegaCam, a joint project of CFHT and CEA/DAPNIA, at the Canada-France-Hawaii Telescope (CFHT) which is operated by the National Research Council (NRC) of Canada, the Institut National des Sciences de l'Univers of the Centre National de la Recherche Scientifique (CNRS) of France, and the University of Hawaii. This work is based in part on data products produced at TERAPIX and the Canadian Astronomy Data Centre as part of the Canada-France-Hawaii Telescope Legacy Survey, a collaborative project of NRC and CNRS. Based on observations made

  18. A simple method for finding the scattering coefficients of quantum graphs

    International Nuclear Information System (INIS)

    Cottrell, Seth S.

    2015-01-01

    Quantum walks are roughly analogous to classical random walks, and similar to classical walks they have been used to find new (quantum) algorithms. When studying the behavior of large graphs or combinations of graphs, it is useful to find the response of a subgraph to signals of different frequencies. In doing so, we can replace an entire subgraph with a single vertex with variable scattering coefficients. In this paper, a simple technique for quickly finding the scattering coefficients of any discrete-time quantum graph will be presented. These scattering coefficients can be expressed entirely in terms of the characteristic polynomial of the graph’s time step operator. This is a marked improvement over previous techniques which have traditionally required finding eigenstates for a given eigenvalue, which is far more computationally costly. With the scattering coefficients we can easily derive the “impulse response” which is the key to predicting the response of a graph to any signal. This gives us a powerful set of tools for rapidly understanding the behavior of graphs or for reducing a large graph into its constituent subgraphs regardless of how they are connected

  19. Literature Shows Recurring Efforts at Finding a Method of Teaching Ethics.

    Science.gov (United States)

    Knudtson, Judy

    1994-01-01

    Reviews classroom journalism texts and articles published in "Quill and Scroll" and this journal since the early 1970s. Notes that the topic of ethics has been addressed recurrently. Finds a wealth of commitment to and concern for ethical issues for high school journalists. (RS)

  20. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data

    DEFF Research Database (Denmark)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-01-01

    ). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold...... LCA and SNOB LCA). METHODS: The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program...... classify individuals into those subgroups. CONCLUSIONS: Our subjective judgement was that Latent Gold offered the best balance of sensitivity to subgroups, ease of use and presentation of results with these datasets but we recognise that different clustering methods may suit other types of data...

  1. Finding all real roots of a polynomial by matrix algebra and the Adomian decomposition method

    Directory of Open Access Journals (Sweden)

    Hooman Fatoorehchi

    2014-10-01

    Full Text Available In this paper, we put forth a combined method for calculation of all real zeroes of a polynomial equation through the Adomian decomposition method equipped with a number of developed theorems from matrix algebra. These auxiliary theorems are associated with eigenvalues of matrices and enable convergence of the Adomian decomposition method toward different real roots of the target polynomial equation. To further improve the computational speed of our technique, a nonlinear convergence accelerator known as the Shanks transform has optionally been employed. For the sake of illustration, a number of numerical examples are given.

  2. Towards understanding household-level forest reliance in Cambodia - study sites, methods, and preliminary findings

    DEFF Research Database (Denmark)

    Ra, Koy; Pichdara, Lonn; Dararath, Yem

    There is growing international interest in the role of forests in poverty prevention and reduction. In consequence, this broad area of investigation has been subject to increased research; one major international research project is that facilitated by the Poverty Environment Network (PEN). This ......). This project covers a large number of sites in 26 countries throughout the tropics. The present report contains contextual details, methodological information and preliminary findings for the PEN sites in Cambodia....

  3. CT findings of pancreatic carcinoma. Evaluation with the combined method of early enhancement CT and high dose enhancement CT

    International Nuclear Information System (INIS)

    Itoh, Shigeki; Endo, Tokiko; Isomura, Takayuki; Ishigaki, Takeo; Ikeda, Mitsuru; Senda, Kouhei.

    1995-01-01

    Computed tomographic (CT) findings of pancreatic ductal adenocarcinoma were studied with the combined method of early enhancement CT and high dose enhancement CT in 72 carcinomas. Common Findings were change in pancreatic contour, abnormal attenuation in a tumor and dilatation of the main pancreatic duct. The incidence of abnormal attenuation and dilatation of the main pancreatic duct and bile duct was constant regardless of tumor size. The finding of hypoattenuation at early enhancement CT was most useful for demonstrating a carcinoma. However, this finding was negative in ten cases, five of which showed inhomogenous hyperattenuation at high dose enhancement CT. The detection of change in pancreatic contour and dilatation of the main pancreatic duct was most frequent at high dose enhancement CT. The finding of change in pancreatic contour and/or abnormal attenuation in a tumor could be detected in 47 cases at plain CT, 66 at early enhancement CT and 65 at high dose enhancement CT. Since the four cases in which neither finding was detected by any CT method showed dilatated main pancreatic duct, there was no case without abnormal CT findings. This combined CT method will be a reliable diagnostic technique in the imaging of pancreatic carcinoma. (author)

  4. Exploration of barriers and facilitators to publishing local public health findings: A mixed methods protocol

    OpenAIRE

    Smith, Selina A.; Webb, Nancy C.; Blumenthal, Daniel S.; Willcox, Bobbie; Ballance, Darra; Kinard, Faith; Gates, Madison L.

    2016-01-01

    Background Worldwide, the US accounts for a large proportion of journals related to public health. Although the American Public Health Association (APHA) includes 54 affiliated regional and state associations, little is known about their capacity to support public health scholarship. The aim of this study is to assess barriers and facilitators to operation of state journals for the dissemination of local public health research and practices. Methods A mixed methods approach will be used to co...

  5. Hybrid of Natural Element Method (NEM with Genetic Algorithm (GA to find critical slip surface

    Directory of Open Access Journals (Sweden)

    Shahriar Shahrokhabadi

    2014-06-01

    Full Text Available One of the most important issues in geotechnical engineering is the slope stability analysis for determination of the factor of safety and the probable slip surface. Finite Element Method (FEM is well suited for numerical study of advanced geotechnical problems. However, mesh requirements of FEM creates some difficulties for solution processing in certain problems. Recently, motivated by these limitations, several new Meshfree methods such as Natural Element Method (NEM have been used to analyze engineering problems. This paper presents advantages of using NEM in 2D slope stability analysis and Genetic Algorithm (GA optimization to determine the probable slip surface and the related factor of safety. The stress field is produced under plane strain condition using natural element formulation to simulate material behavior analysis utilized in conjunction with a conventional limit equilibrium method. In order to justify the preciseness and convergence of the proposed method, two kinds of examples, homogenous and non-homogenous, are conducted and results are compared with FEM and conventional limit equilibrium methods. The results show the robustness of the NEM in slope stability analysis.

  6. Quantum size correction to the work function and the centroid of excess charge in positively ionized simple metal clusters

    Directory of Open Access Journals (Sweden)

    M. Payami

    2003-12-01

    Full Text Available  In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct position of the centroid of excess charge in positively charged simple metal clusters with different values . For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes in the framework of local spin-density approximation and stabilized jellium model (SJM as well as simple jellium model (JM with rigid jellium. Secondly, we have fitted our results to the asymptotic ionization formulas both with and without the size correction to the work function. The results of fittings show that the formula containing the size correction predict a correct position of the centroid inside the jellium while the other predicts a false position, outside the jellium sphere.

  7. 4fn-15d centroid shift in lanthanides and relation with anion polarizability, covalency, and cation electronegativity

    International Nuclear Information System (INIS)

    Dorenbos, P.; Andriessen, J.; Eijk, C.W.E. van

    2003-01-01

    Data collected on the centroid shift of the 5d-configuration of Ce 3+ in oxide and fluoride compounds were recently analyzed with a model involving the correlated motion between 5d-electron and ligand electrons. The correlation effects are proportional to the polarizability of the anion ligands and it leads, like covalency, to lowering of the 5d-orbital energies. By means of ab initio Hartree-Fock-LCAO calculations including configuration interaction the contribution from covalency and correlated motion to the centroid shift are determined separately for Ce 3+ in various compounds. It will be shown that in fluoride compounds, covalency provides an insignificant contribution. In oxides, polarizability appears to be of comparable importance as covalency

  8. Quantum size correction to the work function and centroid of excess charge in positively ionized simple metal clusters

    International Nuclear Information System (INIS)

    Payami, M.

    2004-01-01

    In this work, we have shown the important role of the finite-size correction to the work function in predicting the correct position of the centroid of excess charge in positively charged simple metal clusters with different r s values (2≤ r s ≥ 7). For this purpose, firstly we have calculated the self-consistent Kohn-Sham energies of neutral and singly-ionized clusters with sizes 2≤ N ≥100 in the framework of local spin-density approximation and stabilized jellium model as well as simple jellium model with rigid jellium. Secondly, we have fitted our results to the asymptotic ionization formulas both with and without the size correction to the work function. The results of fittings show that the formula containing the size correction predict a correct position of the centroid inside the jellium while the other predicts a false position, outside the jellium sphere

  9. Centroid and Envelope Eynamics of Charged Particle Beams in an Oscillating Wobbler and External Focusing Lattice for Heavy Ion Fusion Applications

    International Nuclear Information System (INIS)

    Davidson, Ronald C.; Logan, B. Grant

    2011-01-01

    Recent heavy ion fusion target studies show that it is possible to achieve ignition with direct drive and energy gain larger than 100 at 1MJ. To realize these advanced, high-gain schemes based on direct drive, it is necessary to develop a reliable beam smoothing technique to mitigate instabilities and facilitate uniform deposition on the target. The dynamics of the beam centroid can be explored as a possible beam smoothing technique to achieve a uniform illumination over a suitably chosen region of the target. The basic idea of this technique is to induce an oscillatory motion of the centroid for each transverse slice of the beam in such a way that the centroids of different slices strike different locations on the target. The centroid dynamics is controlled by a set of biased electrical plates called 'wobblers'. Using a model based on moments of the Vlasov-Maxwell equations, we show that the wobbler deflection force acts only on the centroid motion, and that the envelope dynamics are independent of the wobbler fields. If the conducting wall is far away from the beam, then the envelope dynamics and centroid dynamics are completely decoupled. This is a preferred situation for the beam wobbling technique, because the wobbler system can be designed to generate the desired centroid motion on the target without considering its effects on the envelope and emittance. A conceptual design of the wobbler system for a heavy ion fusion driver is briefly summarized.

  10. The Lagrangian Multiplier Method of Finding Upper and Lower Limits to Critical Stresses of Clamped Plates

    Science.gov (United States)

    1946-01-01

    geometrica ~ boundary condi- tions of the problem. (2) The energy of the load-plate system is computed for this deflection surface and is then minimized...and interpolating to find the k that makes the seriw vanish. The correct value of m is that which gives the lowest value of k. For two half waves (m=2...the square plate, the present rekdively simple upper- and lower-limit calcula- tions show that his est,imatd limit of error is correct for this case

  11. A numerical method for finding sign-changing solutions of superlinear Dirichlet problems

    Energy Technology Data Exchange (ETDEWEB)

    Neuberger, J.M.

    1996-12-31

    In a recent result it was shown via a variational argument that a class of superlinear elliptic boundary value problems has at least three nontrivial solutions, a pair of one sign and one which sign changes exactly once. These three and all other nontrivial solutions are saddle points of an action functional, and are characterized as local minima of that functional restricted to a codimension one submanifold of the Hilbert space H-0-1-2, or an appropriate higher codimension subset of that manifold. In this paper, we present a numerical Sobolev steepest descent algorithm for finding these three solutions.

  12. Neutron radiography with sub-15 {mu}m resolution through event centroiding

    Energy Technology Data Exchange (ETDEWEB)

    Tremsin, Anton S., E-mail: ast@ssl.berkeley.edu [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); McPhate, Jason B.; Vallerga, John V.; Siegmund, Oswald H.W. [Space Sciences Laboratory, University of California at Berkeley, Berkeley, CA 94720 (United States); Bruce Feller, W. [NOVA Scientific, Inc. 10 Picker Road, Sturbridge, MA 01566 (United States); Lehmann, Eberhard; Kaestner, Anders; Boillat, Pierre; Panzner, Tobias; Filges, Uwe [Spallation Neutron Source Division, Paul Scherrer Institute, CH-5232 Villigen (Switzerland)

    2012-10-01

    Conversion of thermal and cold neutrons into a strong {approx}1 ns electron pulse with an absolute neutron detection efficiency as high as 50-70% makes detectors with {sup 10}B-doped Microchannel Plates (MCPs) very attractive for neutron radiography and microtomography applications. The subsequent signal amplification preserves the location of the event within the MCP pore (typically 6-10 {mu}m in diameter), providing the possibility to perform neutron counting with high spatial resolution. Different event centroiding techniques of the charge landing on a patterned anode enable accurate reconstruction of the neutron position, provided the charge footprints do not overlap within the time required for event processing. The new fast 2 Multiplication-Sign 2 Timepix readout with >1.2 kHz frame rates provides the unique possibility to detect neutrons with sub-15 {mu}m resolution at several MHz/cm{sup 2} counting rates. The results of high resolution neutron radiography experiments presented in this paper, demonstrate the sub-15 {mu}m resolution capability of our detection system. The high degree of collimation and cold spectrum of ICON and BOA beamlines combined with the high spatial resolution and detection efficiency of MCP-Timepix detectors are crucial for high contrast neutron radiography and microtomography with high spatial resolution. The next generation of Timepix electronics with sparsified readout should enable counting rates in excess of 10{sup 7} n/cm{sup 2}/s taking full advantage of high beam intensity of present brightest neutron imaging facilities.

  13. Forecasting the Rupture Directivity of Large Earthquakes: Centroid Bias of the Conditional Hypocenter Distribution

    Science.gov (United States)

    Donovan, J.; Jordan, T. H.

    2012-12-01

    Forecasting the rupture directivity of large earthquakes is an important problem in probabilistic seismic hazard analysis (PSHA), because directivity is known to strongly influence ground motions. We describe how rupture directivity can be forecast in terms of the "conditional hypocenter distribution" or CHD, defined to be the probability distribution of a hypocenter given the spatial distribution of moment release (fault slip). The simplest CHD is a uniform distribution, in which the hypocenter probability density equals the moment-release probability density. For rupture models in which the rupture velocity and rise time depend only on the local slip, the CHD completely specifies the distribution of the directivity parameter D, defined in terms of the degree-two polynomial moments of the source space-time function. This parameter, which is zero for a bilateral rupture and unity for a unilateral rupture, can be estimated from finite-source models or by the direct inversion of seismograms (McGuire et al., 2002). We compile D-values from published studies of 65 large earthquakes and show that these data are statistically inconsistent with the uniform CHD advocated by McGuire et al. (2002). Instead, the data indicate a "centroid biased" CHD, in which the expected distance between the hypocenter and the hypocentroid is less than that of a uniform CHD. In other words, the observed directivities appear to be closer to bilateral than predicted by this simple model. We discuss the implications of these results for rupture dynamics and fault-zone heterogeneities. We also explore their PSHA implications by modifying the CyberShake simulation-based hazard model for the Los Angeles region, which assumed a uniform CHD (Graves et al., 2011).

  14. Quick regional centroid moment tensor solutions for the Emilia 2012 (northern Italy seismic sequence

    Directory of Open Access Journals (Sweden)

    Silvia Pondrelli

    2012-10-01

    Full Text Available In May 2012, a seismic sequence struck the Emilia region (northern Italy. The mainshock, of Ml 5.9, occurred on May 20, 2012, at 02:03 UTC. This was preceded by a smaller Ml 4.1 foreshock some hours before (23:13 UTC on May 19, 2012 and followed by more than 2,500 earthquakes in the magnitude range from Ml 0.7 to 5.2. In addition, on May 29, 2012, three further strong earthquakes occurred, all with magnitude Ml ≥5.2: a Ml 5.8 earthquake in the morning (07:00 UTC, followed by two events within just 5 min of each other, one at 10:55 UTC (Ml 5.3 and the second at 11:00 UTC (Ml 5.2. For all of the Ml ≥4.0 earthquakes in Italy and for all of the Ml ≥4.5 in the Mediterranean area, an automatic procedure for the computation of a regional centroid moment tensor (RCMT is triggered by an email alert. Within 1 h of the event, a manually revised quick RCMT (QRCMT can be published on the website if the solution is considered stable. In particular, for the Emilia seismic sequence, 13 QRCMTs were determined and for three of them, those with M >5.5, the automatically computed QRCMTs fitted the criteria for publication without manual revision. Using this seismic sequence as a test, we can then identify the magnitude threshold for automatic publication of our QRCMTs.

  15. The Findings from the OECD/NEA/CSNI UMS (Uncertainty Method Study)

    International Nuclear Information System (INIS)

    D'Auria, F.; Glaeser, H.

    2013-01-01

    Within licensing procedures there is the incentive to replace the conservative requirements for code application by a 'best estimate' concept supplemented by an uncertainty analysis to account for predictive uncertainties of code results. Methods have been developed to quantify these uncertainties. The Uncertainty Methods Study (UMS) Group, following a mandate from CSNI (Committee on the Safety of Nuclear Installations) of OECD/NEA (Organization for Economic Cooperation and Development / Nuclear Energy Agency), has compared five methods for calculating the uncertainty in the predictions of advanced 'best estimate' thermal-hydraulic codes. Most of the methods identify and combine input uncertainties. The major differences between the predictions of the methods came from the choice of uncertain parameters and the quantification of the input uncertainties, i.e. the wideness of the uncertainty ranges. Therefore, suitable experimental and analytical information has to be selected to specify these uncertainty ranges or distributions. After the closure of the Uncertainty Method Study (UMS) and after the report was issued comparison calculations of experiment LSTF-SB-CL-18 were performed by University of Pisa using different versions of the RELAP 5 code. It turned out that the version used by two of the participants calculated a 170 K higher peak clad temperature compared with other versions using the same input deck. This may contribute to the differences of the upper limit of the uncertainty ranges. A 'bifurcation' analysis was also performed by the same research group also providing another way of interpreting the high temperature peak calculated by two of the participants. (authors)

  16. An efficient search method for finding the critical slip surface using the compositional Monte Carlo technique

    International Nuclear Information System (INIS)

    Goshtasbi, K.; Ahmadi, M; Naeimi, Y.

    2008-01-01

    Locating the critical slip surface and the associated minimum factor of safety are two complementary parts in a slope stability analysis. A large number of computer programs exist to solve slope stability problems. Most of these programs, however, have used inefficient and unreliable search procedures to locate the global minimum factor of safety. This paper presents an efficient and reliable method to determine the global minimum factor of safety coupled with a modified version of the Monte Carlo technique. Examples arc presented to illustrate the reliability of the proposed method

  17. The strengths and limitations of effective centroid force models explored by studying isotopic effects in liquid water

    Science.gov (United States)

    Yuan, Ying; Li, Jicun; Li, Xin-Zheng; Wang, Feng

    2018-05-01

    The development of effective centroid potentials (ECPs) is explored with both the constrained-centroid and quasi-adiabatic force matching using liquid water as a test system. A trajectory integrated with the ECP is free of statistical noises that would be introduced when the centroid potential is approximated on the fly with a finite number of beads. With the reduced cost of ECP, challenging experimental properties can be studied in the spirit of centroid molecular dynamics. The experimental number density of H2O is 0.38% higher than that of D2O. With the ECP, the H2O number density is predicted to be 0.42% higher, when the dispersion term is not refit. After correction of finite size effects, the diffusion constant of H2O is found to be 21% higher than that of D2O, which is in good agreement with the 29.9% higher diffusivity for H2O observed experimentally. Although the ECP is also able to capture the redshifts of both the OH and OD stretching modes in liquid water, there are a number of properties that a classical simulation with the ECP will not be able to recover. For example, the heat capacities of H2O and D2O are predicted to be almost identical and higher than the experimental values. Such a failure is simply a result of not properly treating quantized vibrational energy levels when the trajectory is propagated with classical mechanics. Several limitations of the ECP based approach without bead population reconstruction are discussed.

  18. Simultaneous hit finding and timing method for pulse shape analysis of drift chamber signals

    Energy Technology Data Exchange (ETDEWEB)

    Schaile, D; Schaile, O; Schwarz, J

    1986-01-01

    An algorithm for the analysis of the digitized signal waveform of drift chamber pulses is described which yields a good multihit resolution and an accurate drift time determination with little processing time. The method has been tested and evaluated with measured pulse shapes from the full size prototype of the OPAL central detector which were digitized by 100 MHz FADCs. (orig.).

  19. Simultaneous hit finding and timing method for pulse shape analysis of drift chamber signals

    Energy Technology Data Exchange (ETDEWEB)

    Schaile, D; Schaile, O; Schwarz, J

    1986-01-01

    An algorithm for the analysis of the digitized signal waveform of drift chamber pulses is described which yields a good multihit resolution and an accurate drift time determination with little processing time. The method has been tested and evaluated with measured pulse shapes from the full size prototype of the OPAL central detector which were digitized by 100 MHz FADCs.

  20. Towards predicting the (dis)comfort performance by modelling: methods and findings

    NARCIS (Netherlands)

    Naddeo, A.

    2017-01-01

    The research work underlying this thesis starts from a societal issue: A comfortable artefact helps people to improve their well-being and can be sold easier.
    In order to fulfil these two requirements (wellbeing and companies’ profit) a comfort-driven human-centred design method is

  1. A Simple Method to Find out when an Ordinary Differential Equation Is Separable

    Science.gov (United States)

    Cid, Jose Angel

    2009-01-01

    We present an alternative method to that of Scott (D. Scott, "When is an ordinary differential equation separable?", "Amer. Math. Monthly" 92 (1985), pp. 422-423) to teach the students how to discover whether a differential equation y[prime] = f(x,y) is separable or not when the nonlinearity f(x, y) is not explicitly factorized. Our approach is…

  2. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality - preliminary findings

    International Nuclear Information System (INIS)

    Mieville, Frederic A.; Gudinchet, Francois; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Bochud, Francois O.; Verdun, Francis R.

    2011-01-01

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI vol 4.8-7.9 mGy, DLP 37.1-178.9 mGy.cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone. (orig.)

  3. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality - preliminary findings

    Energy Technology Data Exchange (ETDEWEB)

    Mieville, Frederic A. [University Hospital Center and University of Lausanne, Institute of Radiation Physics, Lausanne (Switzerland); University Hospital Center and University of Lausanne, Institute of Radiation Physics - Medical Radiology, Lausanne (Switzerland); Gudinchet, Francois; Rizzo, Elena [University Hospital Center and University of Lausanne, Department of Radiology, Lausanne (Switzerland); Ou, Phalla; Brunelle, Francis [Necker Children' s Hospital, Department of Radiology, Paris (France); Bochud, Francois O.; Verdun, Francis R. [University Hospital Center and University of Lausanne, Institute of Radiation Physics, Lausanne (Switzerland)

    2011-09-15

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI{sub vol} 4.8-7.9 mGy, DLP 37.1-178.9 mGy.cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p < 0.001) whereas with ASIR above 50%, image quality significantly decreased (p < 0.001). With 100% ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone. (orig.)

  4. A critical assessment of theoretical methods for finding reaction pathways and transition states of surface processes

    International Nuclear Information System (INIS)

    Klimes, JirI; Michaelides, Angelos; Bowler, David R

    2010-01-01

    The performance of a variety of techniques for locating transition states on potential energy surfaces is evaluated within the density functional theory framework. Diffusion of a water molecule across NaCl(001) and HCl bond breaking on the same surface are treated as general test cases; the former is an example of a low barrier diffusion process and the latter an example of a relatively high barrier covalent bond rupture event. The methods considered include the nudged elastic band (NEB), Dewar, Healy and Stewart (DHS), dimer, constrained optimization (CO), activation-relaxation technique (ART) and one-side growing string (OGS) as well as novel combinations of the DHS with growing string (DHS + GS) and DHS plus climbing image (CI-DHS). A key conclusion to come from this study is that the NEB method is relatively fast, especially when just a single (climbing) image is used. Indeed, using more images represents an unnecessary computational burden for our set of processes. The dimer method exhibits variable performance; being poor for the water diffusion processes, which have small activation energies, but much more efficient for the HCl bond breaking process which has a higher barrier. When only a poor initial guess of the transition state geometry is available, the CI-DHS scheme is one of the most efficient techniques considered. And as a means to quickly establish an approximate minimum energy pathway the DHS + GS scheme offers some potential.

  5. A comparison of companion matrix methods to find roots of a trigonometric polynomial

    Science.gov (United States)

    Boyd, John P.

    2013-08-01

    A trigonometric polynomial is a truncated Fourier series of the form fN(t)≡∑j=0Naj cos(jt)+∑j=1N bj sin(jt). It has been previously shown by the author that zeros of such a polynomial can be computed as the eigenvalues of a companion matrix with elements which are complex valued combinations of the Fourier coefficients, the "CCM" method. However, previous work provided no examples, so one goal of this new work is to experimentally test the CCM method. A second goal is introduce a new alternative, the elimination/Chebyshev algorithm, and experimentally compare it with the CCM scheme. The elimination/Chebyshev matrix (ECM) algorithm yields a companion matrix with real-valued elements, albeit at the price of usefulness only for real roots. The new elimination scheme first converts the trigonometric rootfinding problem to a pair of polynomial equations in the variables (c,s) where c≡cos(t) and s≡sin(t). The elimination method next reduces the system to a single univariate polynomial P(c). We show that this same polynomial is the resultant of the system and is also a generator of the Groebner basis with lexicographic ordering for the system. Both methods give very high numerical accuracy for real-valued roots, typically at least 11 decimal places in Matlab/IEEE 754 16 digit floating point arithmetic. The CCM algorithm is typically one or two decimal places more accurate, though these differences disappear if the roots are "Newton-polished" by a single Newton's iteration. The complex-valued matrix is accurate for complex-valued roots, too, though accuracy decreases with the magnitude of the imaginary part of the root. The cost of both methods scales as O(N3) floating point operations. In spite of intimate connections of the elimination/Chebyshev scheme to two well-established technologies for solving systems of equations, resultants and Groebner bases, and the advantages of using only real-valued arithmetic to obtain a companion matrix with real-valued elements

  6. Seismicity in the block mountains between Halle and Leipzig, Central Germany: centroid moment tensors, ground motion simulation, and felt intensities of two M ≈ 3 earthquakes in 2015 and 2017

    Science.gov (United States)

    Dahm, Torsten; Heimann, Sebastian; Funke, Sigward; Wendt, Siegfried; Rappsilber, Ivo; Bindi, Dino; Plenefisch, Thomas; Cotton, Fabrice

    2018-05-01

    On April 29, 2017 at 0:56 UTC (2:56 local time), an M W = 2.8 earthquake struck the metropolitan area between Leipzig and Halle, Germany, near the small town of Markranstädt. The earthquake was felt within 50 km from the epicenter and reached a local intensity of I 0 = IV. Already in 2015 and only 15 km northwest of the epicenter, a M W = 3.2 earthquake struck the area with a similar large felt radius and I 0 = IV. More than 1.1 million people live in the region, and the unusual occurrence of the two earthquakes led to public attention, because the tectonic activity is unclear and induced earthquakes have occurred in neighboring regions. Historical earthquakes south of Leipzig had estimated magnitudes up to M W ≈ 5 and coincide with NW-SE striking crustal basement faults. We use different seismological methods to analyze the two recent earthquakes and discuss them in the context of the known tectonic structures and historical seismicity. Novel stochastic full waveform simulation and inversion approaches are adapted for the application to weak, local earthquakes, to analyze mechanisms and ground motions and their relation to observed intensities. We find NW-SE striking normal faulting mechanisms for both earthquakes and centroid depths of 26 and 29 km. The earthquakes are located where faults with large vertical offsets of several hundred meters and Hercynian strike have developed since the Mesozoic. We use a stochastic full waveform simulation to explain the local peak ground velocities and calibrate the method to simulate intensities. Since the area is densely populated and has sensitive infrastructure, we simulate scenarios assuming that a 12-km long fault segment between the two recent earthquakes is ruptured and study the impact of rupture parameters on ground motions and expected damage.

  7. The Family Investigation of Nephropathy and Diabetes (FIND): design and methods.

    Science.gov (United States)

    Knowler, William C; Coresh, Josef; Elston, Robert C; Freedman, Barry I; Iyengar, Sudha K; Kimmel, Paul L; Olson, Jane M; Plaetke, Rosemarie; Sedor, John R; Seldin, Michael F

    2005-01-01

    The Family Investigation of Nephropathy and Diabetes (FIND) is a multicenter study designed to identify genetic determinants of diabetic nephropathy. It is conducted in eight U.S. clinical centers and a coordinating center, and with four ethnic groups (European Americans, African Americans, Mexican Americans, and American Indians). Two strategies are used to localize susceptibility genes: a family-based linkage study and a case-control study using mapping by admixture linkage disequilibrium (MALD). In the family-based study, probands with diabetic nephropathy are recruited with their parents and selected siblings. Linkage analyses will be conducted to identify chromosomal regions containing genes that influence the development of diabetic nephropathy or related quantitative traits such as serum creatinine concentration, urinary albumin excretion, and plasma glucose concentrations. Regions showing evidence of linkage will be examined further with both genetic linkage and association studies to identify genes that influence diabetic nephropathy or related traits. Two types of MALD studies are being done. One is a case-control study of unrelated individuals of Mexican American heritage in which both cases and controls have diabetes, but only the case has nephropathy. The other is a case-control study of African American patients with nephropathy (cases) and their spouses (controls) unaffected by diabetes and nephropathy; offspring are genotyped when available to provide haplotype data. Identification of genes that influence susceptibility to diabetic nephropathy will lead to a better understanding of how nephropathy develops. This should eventually lead to improved treatment and prevention.

  8. The use of multicriteria decision making methods to find the environmental costs of hydropower development alternatives

    International Nuclear Information System (INIS)

    Carlsen, A.J.; Wenstoep, F.

    1994-01-01

    The conference paper deals with a decision support system (DSS) developed to find the costs of environmental goods. The system is based on multicriteria decision making and uses pairwise comparisons of two and two criteria. The criteria weights are calculated with linear regression. When one criterion is monetary, all criteria weights can be expressed in monetary units when the weights are known. The DSS has been tested on a hydropower project in the area of Sauda in Norway. To represent the decision makers, three panels each consisting of three persons were formed. The persons were selected from governmental agencies, the developers, the local environmental administration and a local politician. The DSS worked well with the panels. One problem was that impacts of hydropower projects are very site specific and also hard to quantify. Therefore, a considerable amount of time was used in creating a cognitive understanding of the issues involved and how they were represented by quantitative criteria. Some had also difficulties in accepting the principle of expressing environmental goods in monetary units. The results so far are preliminary. This research work is part of the Norwegian research programme Energy, Environment and Development. 3 refs., 4 figs., 2 tabs

  9. Microplastic pollution in China's inland water systems: A review of findings, methods, characteristics, effects, and management.

    Science.gov (United States)

    Zhang, Kai; Shi, Huahong; Peng, Jinping; Wang, Yinghui; Xiong, Xiong; Wu, Chenxi; Lam, Paul K S

    2018-07-15

    The pollution of marine environments and inland waters by plastic debris has raised increasing concerns worldwide in recent years. China is the world's largest developing country and the largest plastic producer. In this review, we gather available information on microplastic pollution in China's inland water systems. The results show that microplastics are ubiquitous in the investigated inland water systems, and high microplastic abundances were observed in developed areas. Although similar sampling and analytical methods were used for microplastic research in inland water and marine systems, methods of investigation should be standardized in the future. The characteristics of the detected microplastics suggest secondary sources as their major sources. The biological and ecological effects of microplastics have been demonstrated, but their risks are difficult to determine at this stage due to the discrepancy between the field-collected microplastics and microplastics used in ecotoxicological studies. Although many laws and regulations have already been established to manage and control plastic waste in China, the implementation of these laws and regulations has been ineffective and sometimes difficult. Several research priorities are identified, and we suggest that the Chinese government should be more proactive in tackling plastic pollution problems to protect the environment and fulfill international responsibilities. Copyright © 2018 Elsevier B.V. All rights reserved.

  10. The value of earth observations: methods and findings on the value of Landsat imagery

    Science.gov (United States)

    Miller, Holly M.; Serbina, Larisa O.; Richardson, Leslie A.; Ryker, Sarah J.; Newman, Timothy R.

    2016-01-01

    Data from Earth observation systems are used extensively in managing and monitoring natural resources, natural hazards, and the impacts of climate change, but the value of such data can be difficult to estimate, particularly when it is available at no cost. Assessing the socioeconomic and scientific value of these data provides a better understanding of the existing and emerging research, science, and applications related to this information and contributes to the decision making process regarding current and future Earth observation systems. Recent USGS research on Landsat data has advanced the literature in this area by using a variety of methods to estimate value. The results of a 2012 survey of Landsat users, a 2013 requirements assessment, and 2013 case studies of applications of Landsat imagery are discussed.

  11. Three-Dimensional Computed Tomography as a Method for Finding Die Attach Voids in Diodes

    Science.gov (United States)

    Brahm, E. N.; Rolin, T. D.

    2010-01-01

    NASA analyzes electrical, electronic, and electromechanical (EEE) parts used in space vehicles to understand failure modes of these components. The diode is an EEE part critical to NASA missions that can fail due to excessive voiding in the die attach. Metallography, one established method for studying the die attach, is a time-intensive, destructive, and equivocal process whereby mechanical grinding of the diodes is performed to reveal voiding in the die attach. Problems such as die attach pull-out tend to complicate results and can lead to erroneous conclusions. The objective of this study is to determine if three-dimensional computed tomography (3DCT), a nondestructive technique, is a viable alternative to metallography for detecting die attach voiding. The die attach voiding in two- dimensional planes created from 3DCT scans was compared to several physical cross sections of the same diode to determine if the 3DCT scan accurately recreates die attach volumetric variability

  12. Description and pilot results from a novel method for evaluating return of incidental findings from next-generation sequencing technologies.

    Science.gov (United States)

    Goddard, Katrina A B; Whitlock, Evelyn P; Berg, Jonathan S; Williams, Marc S; Webber, Elizabeth M; Webster, Jennifer A; Lin, Jennifer S; Schrader, Kasmintan A; Campos-Outcalt, Doug; Offit, Kenneth; Feigelson, Heather Spencer; Hollombe, Celine

    2013-09-01

    The aim of this study was to develop, operationalize, and pilot test a transparent, reproducible, and evidence-informed method to determine when to report incidental findings from next-generation sequencing technologies. Using evidence-based principles, we proposed a three-stage process. Stage I "rules out" incidental findings below a minimal threshold of evidence and is evaluated using inter-rater agreement and comparison with an expert-based approach. Stage II documents criteria for clinical actionability using a standardized approach to allow experts to consistently consider and recommend whether results should be routinely reported (stage III). We used expert opinion to determine the face validity of stages II and III using three case studies. We evaluated the time and effort for stages I and II. For stage I, we assessed 99 conditions and found high inter-rater agreement (89%), and strong agreement with a separate expert-based method. Case studies for familial adenomatous polyposis, hereditary hemochromatosis, and α1-antitrypsin deficiency were all recommended for routine reporting as incidental findings. The method requires definition of clinically actionable incidental findings and provide documentation and pilot testing of a feasible method that is scalable to the whole genome.

  13. The Teaching of General Solution Methods to Pattern Finding Problems through Focusing on an Evaluation and Improvement Process.

    Science.gov (United States)

    Ishida, Junichi

    1997-01-01

    Examines the effects of a teaching strategy in which fifth-grade students evaluated the strengths or weaknesses of solution methods to pattern finding problems, including an experimental and control group each consisting of 34 elementary students, in Japan. The experimental group showed a significantly better performance on the retention test…

  14. Finding an optimal method for imaging lymphatic vessels of the upper limb

    International Nuclear Information System (INIS)

    O'Mahony, Susan; Purushotham, Arnie D.; Rose, Sarah L.; Chilvers, Alison J.; Ballinger, James R.; Solanki, Chandra K.; Barber, Robert W.; Peters, A. Michael; Mortimer, Peter S.

    2004-01-01

    Lymphoscintigraphy involves interstitial injection of radiolabelled particulate materials or radioproteins. Although several variations in the technique have been described, their place in clinical practice remains controversial. Traditional diagnostic criteria are based primarily on lymph node appearances but in situations such as breast cancer, where lymph nodes may have been excised, these criteria are of limited use. In these circumstances, lymphatic vessel morphology takes on greater importance as a clinical endpoint, so a method that gives good definition of lymphatic vessels would be useful. In patients with breast cancer, for example, such a method, used before and after lymph node resection, may assist in predicting the development of breast cancer-related lymphoedema. The aim of this study was to optimise a method for the visualisation of lymphatic vessels. Subcutaneous (sc) and intradermal (id) injection sites were compared, and technetium-99m nanocolloid, a particulate material, was compared with 99m Tc-human immunoglobulin (HIG), which is a soluble macromolecule. Twelve normal volunteers were each studied on two occasions. In three subjects, id 99m Tc-HIG was compared with sc 99m Tc-HIG, in three id 99m Tc-nanocolloid was compared with sc 99m Tc-nanocolloid, in three id 99m Tc-HIG was compared with id 99m Tc-nanocolloid and in three sc 99m Tc-HIG was compared with sc 99m Tc-nanocolloid. Endpoints were quality of lymphatic vessel definition, the time after injection at which vessels were most clearly visualised, the rate constant of depot disappearance (k) and the systemic blood accumulation rate as measured by gamma camera imaging over the liver or cardiac blood pool. Excellent definition of lymphatic vessels was obtained following id injection of either radiopharmaceutical, an injection route that was clearly superior to sc. Differences between radiopharmaceuticals were less clear, although after id injection, 99m Tc-HIG gave images that were

  15. Modified enthalpy method for the simulation of melting and ...

    Indian Academy of Sciences (India)

    These include the implicit time stepping method of Voller & Cross. (1981), explicit enthalpy method of Tacke (1985), centroidal temperature correction method ... In variable viscosity method, viscosity is written as a function of liquid fraction.

  16. Atmospheric Deposition: Sampling Procedures, Analytical Methods, and Main Recent Findings from the Scientific Literature

    Directory of Open Access Journals (Sweden)

    M. Amodio

    2014-01-01

    Full Text Available The atmosphere is a carrier on which some natural and anthropogenic organic and inorganic chemicals are transported, and the wet and dry deposition events are the most important processes that remove those chemicals, depositing it on soil and water. A wide variety of different collectors were tested to evaluate site-specificity, seasonality and daily variability of settleable particle concentrations. Deposition fluxes of POPs showed spatial and seasonal variations, diagnostic ratios of PAHs on deposited particles, allowed the discrimination between pyrolytic or petrogenic sources. Congener pattern analysis and bulk deposition fluxes in rural sites confirmed long-range atmospheric transport of PCDDs/Fs. More and more sophisticated and newly designed deposition samplers have being used for characterization of deposited mercury, demonstrating the importance of rain scavenging and the relatively higher magnitude of Hg deposition from Chinese anthropogenic sources. Recently biological monitors demonstrated that PAH concentrations in lichens were comparable with concentrations measured in a conventional active sampler in an outdoor environment. In this review the authors explore the methodological approaches used for the assessment of atmospheric deposition, from the analysis of the sampling methods, the analytical procedures for chemical characterization of pollutants and the main results from the scientific literature.

  17. Insights on leadership from early career nurse academics: findings from a mixed methods study.

    Science.gov (United States)

    Halcomb, Elizabeth; Jackson, Debra; Daly, John; Gray, Joanne; Salamonson, Yenna; Andrew, Sharon; Peters, Kath

    2016-03-01

    To explore the perceptions of early career nursing academics on leadership in academia. There is growing emphasis on leadership capacity building across all domains of nursing. However, there is limited evidence on leadership capacity in early career academics. This study tested an intervention to develop leadership capacity amongst early career nursing academics in two Australian universities. A sequential mixed methods design, using online surveys and semi-structured interviews, was used to collect data. Twenty-three early career nursing academics participated. Most had experience of formal leadership roles and were aware of its importance to them as they developed their academic careers. Participants were able to discuss their own views of themselves as leaders; their perceptions of their own needs for leadership development, and ways in which they could seek to develop further as leaders. There is a need to provide initial and ongoing opportunities for leadership development amongst nurse academics. These opportunities should be contextualised and recognise factors such as gender, and the effects of structural oppression. Nurse academics are involved in the preparation of the next generation of clinical leaders and it is imperative that they are able to articulate a clear view of leadership. © 2015 John Wiley & Sons Ltd.

  18. Occupational burnout among radiation therapists in Australia: Findings from a mixed methods study

    International Nuclear Information System (INIS)

    Singh, N.; Wright, C.; Knight, K.; Baird, M.; Akroyd, D.; Adams, R.D.; Schneider, M.E.

    2017-01-01

    Introduction: Evidence demonstrates that health care professionals in the palliative care context are more burned out than other health professionals. The aims of this study were to examine: (1) occupational burnout levels among radiation therapists in Australia, (2) association between demographic factors on burnout and (3) radiation therapists' perceptions of burnout. Methods: A cross-sectional online survey including the Maslach Burnout Inventory was administered to Radiation Therapists in Australia. Data were analysed using SPSS Ver 20 and open ended comments were analysed thematically using Nvivo 10. Results: A total of 200 radiation therapists participated in the survey. RTs had a high mean (±SD) burnout score for emotional exhaustion (38.5 ± 8.2), depersonalisation (17.5 ± 4.7) and personal achievement (30.5.3 ± 4.3) compared to RTs and health workers in other studies. High levels of emotional exhaustion, depersonalisation and low levels of personal achievement were present in 93% (186/200), 87% (174/200) and 61% (122/200) of participants respectively. RTs identified high workload and staff shortages, interpersonal conflict and technology as key sources of stress in the RT work environment. Conclusion: Australian RTs' level of burnout on all three stages of burnout exceed previously reported burnout levels for similar cohorts both locally and internationally. It is important that future interventions aimed at minimising or preventing stressors are identified and implemented in the radiation therapy work environment. - Highlights: • The burnout rate is higher among Australian RTs compared to studies in other countries. • Dealing with patients and their emotions were not a contributing factor to RTs' stress. • Challenging interpersonal relationships between staff was identified as one of the key stressors. • It is important that future interventions aimed at minimising or preventing stressors are recognised.

  19. Exploring community gardens in a health disparate population: findings from a mixed methods pilot study.

    Science.gov (United States)

    Zoellner, Jamie; Zanko, Ashley; Price, Bryan; Bonner, Jennifer; Hill, Jennie L

    2012-01-01

    Despite recommendations, there have been few efforts to apply the community-based participatory research (CBPR) approach in the development, implementation, and evaluation of community gardens. As guided by the CBPR approach and grounded in a social-ecological model and behavioral theory, the purpose of this mixed methods study was to understand opinions and interests in developing and implementing a community garden and to understand factors impacting fruit, vegetable, and gardening behaviors. Community and academic members collaborated to develop and execute this study. The qualitative phase- targeting regional key informants-was designed to elicit perceived benefits and challenges of community gardens at the environmental, community, and individual levels. The quantitative phase targeted low resourced youth and parents and included a variety of validated theory-based questionnaires to understand factors impacting fruit, vegetable, and gardening behaviors. Major benefits of community gardens that emerged from the 10 qualitative interviews included increasing community cohesion and improving nutrition and physical activity factors. The quantitative phase included 87 youth and 67 parents. Across 16 items for fruits and vegetables, the average willingness to try was 1.32 (standard deviation [SD] = 0.40) on a 2-point scale. The majority of youth indicated they would work in a garden (n = 59; 68%) and eat food grown in their garden (n = 71; 82%). Among parents, gardening attitude, belief, and self-efficacy scores were all above average; however, gardening intentions were neutral. This research illustrates the successful partnering a community-academic team and has provided the partnership with a clearer lens to conceptualize and launch future regional community garden efforts.

  20. Healthy bread initiative: methods, findings, and theories--Isfahan Healthy Heart Program.

    Science.gov (United States)

    Talaei, Mohammad; Mohammadifard, Noushin; Khaje, Mohammad-Reza; Sarrafzadegan, Nizal; Sajjadi, Firoozeh; Alikhasi, Hasan; Maghroun, Maryam; Iraji, Farhad; Ehteshami, Shahram

    2013-03-01

    The scientific evidences show that the content, baking methods, and types of bread can make health impacts. Bread, as a major part of Iranian diet, demonstrates a significant potential to be targeted as health promotion subject. Healthy Food for Healthy Communities (HFHC) was a project of Isfahan Healthy Heart Program (IHHP), consisting of a wide variety of strategies, like Healthy Bread (HB) Initiative. The HB Initiative was designed to improve the behaviour of both producers and consumers, mainly aiming at making high-fibre, low-salt bread, eliminating the use of baking soda, providing enough rest time for dough before baking (at least one hour), and enough baking time (at least one minute in oven). A workshop was held for volunteer bakers, and a baker-to-baker training protocol under direct supervision was designed for future volunteers. Cereal Organization was persuaded to provide less refined flour that contained more bran. Health messages in support of new breads were disseminated by media and at bakeries by health professionals. Evaluation of the HB Initiative was done using before-after assessments and population surveys. While HB was baked in 1 (0.01%) bakery at baseline, 402 (41%) bakeries in the intervention area joined the HB Initiative in 2009. Soda was completely eliminated and fibre significantly increased from 4 +/- 0.4 g% before study to 12 +/- 0.6 g% after the intervention (p bread decreased from 13 +/- 1.8 g% to 2 +/- 0.5 g% and was expressed as the most important advantage of this initiative by consumers. People who lived in Isfahan city consumed whole bread 6 times more than those who lived in reference area Arak (p breads as a healthy choice that were compatible with local dishes and made a model to solve the longstanding problems of bread. It used various health promotion approaches but was best consistent with Beattie's model.

  1. An efficient method to find potentially universal population genetic markers, applied to metazoans

    Directory of Open Access Journals (Sweden)

    Chenuil Anne

    2010-09-01

    Full Text Available Abstract Background Despite the impressive growth of sequence databases, the limited availability of nuclear markers that are sufficiently polymorphic for population genetics and phylogeography and applicable across various phyla restricts many potential studies, particularly in non-model organisms. Numerous introns have invariant positions among kingdoms, providing a potential source for such markers. Unfortunately, most of the few known EPIC (Exon Primed Intron Crossing loci are restricted to vertebrates or belong to multigenic families. Results In order to develop markers with broad applicability, we designed a bioinformatic approach aimed at avoiding multigenic families while identifying intron positions conserved across metazoan phyla. We developed a program facilitating the identification of EPIC loci which allowed slight variation in intron position. From the Homolens databases we selected 29 gene families which contained 52 promising introns for which we designed 93 primer pairs. PCR tests were performed on several ascidians, echinoderms, bivalves and cnidarians. On average, 24 different introns per genus were amplified in bilaterians. Remarkably, five of the introns successfully amplified in all of the metazoan genera tested (a dozen genera, including cnidarians. The influence of several factors on amplification success was investigated. Success rate was not related to the phylogenetic relatedness of a taxon to the groups that most influenced primer design, showing that these EPIC markers are extremely conserved in animals. Conclusions Our new method now makes it possible to (i rapidly isolate a set of EPIC markers for any phylum, even outside the animal kingdom, and thus, (ii compare genetic diversity at potentially homologous polymorphic loci between divergent taxa.

  2. Healthy Bread Initiative: Methods, Findings, and Theories—Isfahan Healthy Heart Program

    Science.gov (United States)

    Talaei, Mohammad; Khaje, Mohammad-Reza; Sarrafzadegan, Nizal; Sajjadi, Firoozeh; Alikhasi, Hasan; Maghroun, Maryam; Iraji, Farhad; Ehteshami, Shahram

    2013-01-01

    The scientific evidences show that the content, baking methods, and types of bread can make health impacts. Bread, as a major part of Iranian diet, demonstrates a significant potential to be targeted as health promotion subject. Healthy Food for Healthy Communities (HFHC) was a project of Isfahan Healthy Heart Program (IHHP), consisting of a wide variety of strategies, like Healthy Bread (HB) Initiative. The HB Initiative was designed to improve the behaviour of both producers and consumers, mainly aiming at making high-fibre, low-salt bread, eliminating the use of baking soda, providing enough rest time for dough before baking (at least one hour), and enough baking time (at least one minute in oven). A workshop was held for volunteer bakers, and a baker-to-baker training protocol under direct supervision was designed for future volunteers. Cereal Organization was persuaded to provide less refined flour that contained more bran. Health messages in support of new breads were disseminated by media and at bakeries by health professionals. Evaluation of the HB Initiative was done using before-after assessments and population surveys. While HB was baked in 1 (0.01%) bakery at baseline, 402 (41%) bakeries in the intervention area joined the HB Initiative in 2009. Soda was completely eliminated and fibre significantly increased from 4±0.4 g% before study to 12±0.6 g% after the intervention (p<0.001). The preparation and baking times remarkably increased. Wastage of bread decreased from 13±1.8 g% to 2±0.5 g% and was expressed as the most important advantage of this initiative by consumers. People who lived in Isfahan city consumed whole bread 6 times more than those who lived in reference area Arak (p<0.001). The HB Initiative managed to add new breads as a healthy choice that were compatible with local dishes and made a model to solve the long-standing problems of bread. It used various health promotion approaches but was best consistent with Beattie's model. PMID

  3. The centroid shift of the 5d levels of Ce3+ with respect to the 4f levels in ionic crystals, a theoretical investigation

    International Nuclear Information System (INIS)

    Andriessen, J.; Dorenbos, P.; Eijk, C.W.E van

    2002-01-01

    The centroid shifts of the 5d level of Ce 3+ in BaF 2 , LaAlO 3 and LaCl 3 have been calculated using the ionic cluster approach. By applying configuration interaction as extension of the basic HF-LCAO approach the dynamical polarization contribution to the centroid shift was calculated. This was found to be only successful if basis sets are used optimized for polarization of the anions

  4. A Review on Hot-IP Finding Methods and Its Application in Early DDoS Target Detection

    Directory of Open Access Journals (Sweden)

    Xuan Dau Hoang

    2016-10-01

    Full Text Available On the high-speed connections of the Internet or computer networks, the IP (Internet Protocol packet traffic passing through the network is extremely high, and that makes it difficult for network monitoring and attack detection applications. This paper reviews methods to find the high-occurrence-frequency elements in the data stream and applies the most efficient methods to find Hot-IPs that are high-frequency IP addresses of IP packets passing through the network. Fast finding of Hot-IPs in the IP packet stream can be effectively used in early detection of DDoS (Distributed Denial of Service attack targets and spreading sources of network worms. Research results show that the Count-Min method gives the best overall performance for Hot-IP detection thanks to its low computational complexity, low space requirement and fast processing speed. We also propose an early detection model of DDoS attack targets based on Hot-IP finding, which can be deployed on the target network routers.

  5. Use of traditional and modern contraceptives among childbearing women: findings from a mixed methods study in two southwestern Nigerian states.

    Science.gov (United States)

    Ajayi, Anthony Idowu; Adeniyi, Oladele Vincent; Akpan, Wilson

    2018-05-09

    Contraceptive use has numerous health benefits such as preventing unplanned pregnancies, ensuring optimum spacing between births, reducing maternal and child mortality, and improving the lives of women and children in general. This study examines the level of contraceptive use, its determinants, reasons for non-use of contraception among women in the reproductive age group (18-49 years) in two southwestern Nigerian states. The study adopted an interviewer-administered questionnaire to collect data from 809 participants selected using a 3-stage cluster random sampling technique. We also conducted 46 in-depth interviews. In order to investigate the association between the socio-demographic variables and use of contraceptive methods, we estimated the binary logistic regression models. The findings indicated that knowledge of any methods of contraception was almost universal among the participants. The rates of ever use and current use of contraception was 80 and 66.6%, respectively. However, only 43.9% of the participants had ever used any modern contraceptive methods, considered to be more reliable. The fear of side effects of modern contraceptive methods drove women to rely on less effective traditional methods (withdrawal and rhythm methods). Some women employed crude and unproven contraceptive methods to prevent pregnancies. Our findings show that the rate of contraceptive use was high in the study setting. However, many women chose less effective traditional contraceptive methods over more effective modern contraceptive methods due to fear of side effects of the latter. Patient education on the various options of modern contraceptives, their side effects and management would be crucial towards expanding the family planning services in the study setting.

  6. The Shortlist Method for fast computation of the Earth Mover's Distance and finding optimal solutions to transportation problems.

    Science.gov (United States)

    Gottschlich, Carsten; Schuhmacher, Dominic

    2014-01-01

    Finding solutions to the classical transportation problem is of great importance, since this optimization problem arises in many engineering and computer science applications. Especially the Earth Mover's Distance is used in a plethora of applications ranging from content-based image retrieval, shape matching, fingerprint recognition, object tracking and phishing web page detection to computing color differences in linguistics and biology. Our starting point is the well-known revised simplex algorithm, which iteratively improves a feasible solution to optimality. The Shortlist Method that we propose substantially reduces the number of candidates inspected for improving the solution, while at the same time balancing the number of pivots required. Tests on simulated benchmarks demonstrate a considerable reduction in computation time for the new method as compared to the usual revised simplex algorithm implemented with state-of-the-art initialization and pivot strategies. As a consequence, the Shortlist Method facilitates the computation of large scale transportation problems in viable time. In addition we describe a novel method for finding an initial feasible solution which we coin Modified Russell's Method.

  7. Meeting report: discussions and preliminary findings on extracellular RNA measurement methods from laboratories in the NIH Extracellular RNA Communication Consortium

    Directory of Open Access Journals (Sweden)

    Louise C. Laurent

    2015-08-01

    Full Text Available Extracellular RNAs (exRNAs have been identified in all tested biofluids and have been associated with a variety of extracellular vesicles, ribonucleoprotein complexes and lipoprotein complexes. Much of the interest in exRNAs lies in the fact that they may serve as signalling molecules between cells, their potential to serve as biomarkers for prediction and diagnosis of disease and the possibility that exRNAs or the extracellular particles that carry them might be used for therapeutic purposes. Among the most significant bottlenecks to progress in this field is the lack of robust and standardized methods for collection and processing of biofluids, separation of different types of exRNA-containing particles and isolation and analysis of exRNAs. The Sample and Assay Standards Working Group of the Extracellular RNA Communication Consortium is a group of laboratories funded by the U.S. National Institutes of Health to develop such methods. In our first joint endeavour, we held a series of conference calls and in-person meetings to survey the methods used among our members, placed them in the context of the current literature and used our findings to identify areas in which the identification of robust methodologies would promote rapid advancements in the exRNA field.

  8. THE ENERGY DEPENDENCE OF THE CENTROID FREQUENCY AND PHASE LAG OF THE QUASI-PERIODIC OSCILLATIONS IN GRS 1915+105

    International Nuclear Information System (INIS)

    Qu, J. L.; Lu, F. J.; Lu, Y.; Song, L. M.; Zhang, S.; Wang, J. M.; Ding, G. Q.

    2010-01-01

    We present a study of the centroid frequencies and phase lags of quasi-periodic oscillations (QPOs) as functions of photon energy for GRS 1915+105. It is found that the centroid frequencies of the 0.5-10 Hz QPOs and their phase lags are both energy dependent, and there exists an anticorrelation between the QPO frequency and phase lag. These new results challenge the popular QPO models, because none of them can fully explain the observed properties. We suggest that the observed QPO phase lags are partially due to the variation of the QPO frequency with energy, especially for those with frequency higher than 3.5 Hz.

  9. A mixed methods investigation of dropout among talented young dancers: findings from the UK Centres for Advanced Training.

    Science.gov (United States)

    Walker, Imogen J; Nordin-Bates, Sanna M; Redding, Emma

    2012-01-01

    The aim of this study was to understand reasons for dropout from a dance-talent program in the UK, using a mixed methods design. In-depth interviews were conducted with ten dropout students to explore the influencing factors in their decision to leave the program. In order to triangulate these findings, reasons for dropout were then examined from descriptive records of 147 young dancers who had withdrawn from the talent program over a four-year period. Overall, the most frequently cited reasons for dropping out were conflicting demands, change in aspirations, course content, difficulty making friends, and lost passion. Injury, financial factors, low perceived competence, and teacher behavior emerged as minor reasons. Intervention strategies that focus on changes in course content may be the easiest to implement and most effective means to enhance student retention.

  10. When are night shifts effective for nursing student clinical learning? Findings from a mixed-method study design.

    Science.gov (United States)

    Palese, Alvisa; Basso, Felix; Del Negro, Elena; Achil, Illarj; Ferraresi, Annamaria; Morandini, Marzia; Moreale, Renzo; Mansutti, Irene

    2017-05-01

    Some nursing programmes offer night shifts for students while others do not, mainly due to the lack of evidence regarding their effectiveness on clinical learning. The principal aims of the study were to describe nursing students' perceptions and to explore conditions influencing effectiveness on learning processes during night shifts. An explanatory mixed-method study design composed of a cross-sectional study (primary method, first phase) followed by a descriptive phenomenological study design (secondary method, second phase) in 2015. Two bachelor of nursing degree programmes located in Northern Italy, three years in length and requiring night shifts for students starting in the second semester of the 1st year, were involved. First phase: all nursing students ending their last clinical placement of the academic year attended were eligible; 352 out the 370 participated. Second phase: a purposeful sample of nine students among those included in the first phase and who attended the highest amount of night shifts were interviewed. First phase: a questionnaire composed of closed and open-ended questions was adopted; data was analyzed through descriptive statistical methods. Second phase: an open-ended face-to-face audio-recorded interview was adopted and data was analyzed through content analysis. Findings from the quantitative phase, showed that students who attended night shifts reported satisfaction (44.7%) less frequently than those who attended only day shifts (55.9%). They also reported boredom (23.5%) significantly more often compared to day shift students (p=0001). Understanding of the nursing role and learning competence was significantly inferior among night shift students as compared to day shift students, while the perception of wasting time was significantly higher among night shift students compared to their counterparts. Night shift students performed nursing rounds (288; 98.2%), non-nursing tasks (247; 84.3%) and/or less often managed clinical problems

  11. Finding possible transition states of defects in silicon-carbide and alpha-iron using the dimer method

    CERN Document Server

    Gao Fei; Weber, W J; Corrales, L R; Jonsson, H

    2003-01-01

    Energetic primary recoil atoms from ion implantation or fast neutron irradiation produce isolated point defects and clusters of both vacancies and interstitials. The migration energies and mechanisms for these defects are crucial to successful multiscale modeling of microstructural evolution during ion-implantation, thermal annealing, or under irradiation over long periods of time. The dimer method is employed to search for possible transition states of interstitials and small interstitial clusters in SiC and alpha-Fe. The method uses only the first derivatives of the potential energy to find saddle points without knowledge of the final state of the transition. In SiC, the possible migration pathway for the C interstitial is found to consist of the first neighbor jump via a Si site or second neighbor jump, but the relative probability for the second neighbor jump is very low. In alpha-Fe, the possible transition states are studied as a function of interstitial cluster size, and the lowest energy barriers corr...

  12. Mixed methods evaluation of targeted case finding for cardiovascular disease prevention using a stepped wedged cluster RCT

    Directory of Open Access Journals (Sweden)

    Marshall Tom

    2012-10-01

    Full Text Available Abstract Background A pilot project cardiovascular prevention was implemented in Sandwell (West Midlands, UK. This used electronic primary care records to identify untreated patients at high risk of cardiovascular disease then invited these high risk patients for assessment by a nurse in their own general practice. Those found to be eligible for treatment were offered treatment. During the pilot a higher proportion of high risk patients were started on treatment in the intervention practices than in control practices. Following the apparent success of the prevention project, it was intended to extend the service to all practices across the Sandwell area. However the pilot project was not a robust evaluation. There was a need for an efficient evaluation that would not disrupt the planned rollout of the project. Methods/design Project nurses will sequentially implement targeted cardiovascular case finding in a phased way across all general practices, with the sequence of general practices determined randomly. This is a stepped wedge randomised controlled trial design. The target population is patients aged 35 to 74, without diabetes or cardiovascular disease whose ten-year cardiovascular risk, (determined from data in their electronic records is ≥20%. The primary outcome is the number of high risk patients started on treatment, because these data could be efficiently obtained from electronic primary care records. From this we can determine the effects of the case finding programme on the proportion of high risk patients started on treatment in practices before and after implementation of targeted case finding. Cost-effectiveness will be modelled from the predicted effects of treatments on cardiovascular events and associated health service costs. Alongside the implementation it is intended to interview clinical staff and patients who participated in the programme in order to determine acceptability to patients and clinicians. Practical

  13. Disconnects in pedagogy and practice in community health nursing clinical experiences: Qualitative findings of a mixed method study.

    Science.gov (United States)

    Pijl-Zieber, Em M; Barton, Sylvia; Awosoga, Olu; Konkin, Jill

    2015-10-01

    Many baccalaureate schools of nursing are using non-traditional placements for undergraduate community health clinical rotations. These placements occur at agencies not organizationally affiliated with the health care system and they typically do not employ registered nurses (RNs). In this paper, we describe the qualitative findings of a mixed method study that explored these gaps as they relate to pre-registration nursing students' preparation for community health roles. While non-traditional community health placements offer unique opportunities for learning through carefully crafted service learning pedagogy, these placements also present challenges for student preparation for practice in community health roles. The theory-practice gap and the gap between the expected and actual performance of new graduates are accentuated through the use of non-traditional community clinical experiences. These gaps are not necessarily due to poor pedagogy, but rather due to the perceptions and values of the stakeholders involved: nursing students, community health nursing faculty, and community health nurses. New ways must be developed between academe and community health practice areas to provide students with opportunities to develop competence for practice. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry.

    Science.gov (United States)

    Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

    2015-06-01

    Diets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population-based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan-fried beefsteak (P(trend) carcinogens relevant for CRC risk. © 2015 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

  15. Cash transfers for HIV prevention: what do young women spend it on? Mixed methods findings from HPTN 068

    Directory of Open Access Journals (Sweden)

    Catherine MacPhail

    2017-07-01

    Full Text Available Abstract Background Social grants have been found to have an impact on health and wellbeing in multiple settings. Who receives the grant, however, has been the subject of discussion with regards to how the money is spent and who benefits from the grant. Methods Using survey data from 1214 young women who were in the intervention arm and completed at least one annual visit in the HPTN 068 trial, and qualitative interview data from a subset of 38 participants, we examined spending of a cash transfer provided to young women conditioned on school attendance. Results We found that spending was largely determined and controlled by young women themselves and that the cash transfer was predominately spent on toiletries, clothing and school supplies. In interview data, young women discussed the significant role of cash transfers for adolescent identity, specifically with regard to independence from family and status within the peer network. There were almost no negative consequences from receiving the cash transfer. Conclusions We established that providing adolescents access to cash was not reported to be associated with social harms or negative consequences. Rather, spending of the cash facilitated appropriate adolescent developmental behaviours. The findings are encouraging at a time in which there is global interest in addressing the structural drivers of HIV risk, such as poverty, for young women. Trial registration Clinicaltrials.gov NCT01233531 (1 Nov 2010. First participant enrolled 5 March 2011.

  16. Meat intake, cooking methods, dietary carcinogens, and colorectal cancer risk: findings from the Colorectal Cancer Family Registry

    International Nuclear Information System (INIS)

    Joshi, Amit D; Kim, Andre; Lewinger, Juan Pablo; Ulrich, Cornelia M; Potter, John D; Cotterchio, Michelle; Le Marchand, Loic; Stern, Mariana C

    2015-01-01

    Diets high in red meat and processed meats are established colorectal cancer (CRC) risk factors. However, it is still not well understood what explains this association. We conducted comprehensive analyses of CRC risk and red meat and poultry intakes, taking into account cooking methods, level of doneness, estimated intakes of heterocyclic amines (HCAs) that accumulate during meat cooking, tumor location, and tumor mismatch repair proficiency (MMR) status. We analyzed food frequency and portion size data including a meat cooking module for 3364 CRC cases, 1806 unaffected siblings, 136 unaffected spouses, and 1620 unaffected population-based controls, recruited into the CRC Family Registry. Odds ratios (OR) and 95% confidence intervals (CI) for nutrient density variables were estimated using generalized estimating equations. We found no evidence of an association between total nonprocessed red meat or total processed meat and CRC risk. Our main finding was a positive association with CRC for pan-fried beefsteak (P trend < 0.001), which was stronger among MMR deficient cases (heterogeneity P = 0.059). Other worth noting associations, of borderline statistical significance after multiple testing correction, were a positive association between diets high in oven-broiled short ribs or spareribs and CRC risk (P trend = 0.002), which was also stronger among MMR-deficient cases, and an inverse association with grilled hamburgers (P trend = 0.002). Our results support the role of specific meat types and cooking practices as possible sources of human carcinogens relevant for CRC risk

  17. Differential impact of contraceptive methods on seizures varies by antiepileptic drug category: Findings of the Epilepsy Birth Control Registry.

    Science.gov (United States)

    Herzog, Andrew G; Mandle, Hannah B; Cahill, Kaitlyn E; Fowler, Kristen M; Hauser, W Allen

    2016-07-01

    The aim of this study was to determine whether categories of contraception differ in their impact on seizures in women with epilepsy and whether the impact varies by antiepileptic drug category. Retrospective survey data came from 2712 contraceptive experiences reported by 1144 women with epilepsy. We compared risk ratios for reports of increase and decrease in seizure frequency on hormonal versus nonhormonal contraception, stratified by antiepileptic drug categories. More women with epilepsy reported a change in seizures on hormonal (28.2%) than on nonhormonal contraception (9.7%) (pcontraception (4.2%) was 4.47 (pcontraception (5.5%) was 1.71, pcontraception, the risk ratio for seizure increase was greater than for decrease (1.98, pmethod with a greater risk ratio for seizure decrease than combined pills. Seizure increase was greater for hormonal than nonhormonal contraception for each antiepileptic drug category (pcontraception, relative to the non-enzyme-inducing antiepileptic drug category which had the lowest rate, each of the other categories had significantly greater risks for seizure increase, especially the enzyme-inhibiting (valproate) category (risk ratio=2.53, p=0.0002). The findings provide community-based, epidemiological survey evidence that contraceptive methods may differ in their impact on seizures and that this impact may vary by antiepileptic drug category. Copyright © 2016. Published by Elsevier Inc.

  18. A Randomized Trial Evaluating Two Approaches for Promoting Pharmacy-Based Referrals to the Tobacco Quitline: Methods and Baseline Findings

    Science.gov (United States)

    Zillich, Alan J.; Corelli, Robin L.; Zbikowski, Susan M.; Magnusson, L. Brooke; Fenlon, Christine M.; Prokhorov, Alexander V.; de Moor, Carl; Hudmon, Karen S.

    2012-01-01

    Background Historically, community pharmacies have not integrated tobacco cessation activities into routine practice, instead unbundling them as unique services. This approach might have limited success and viability. Objective The objective of this report is to describe the methods and baseline findings for a two-state, randomized trial evaluating two intervention approaches for increasing pharmacy-based referrals to their state’s tobacco quitline. Methods Participating community pharmacies in Connecticut (n=32) and Washington (n=32) were randomized to receive either (a) on-site education with an academic detailer, describing methods for implementing brief interventions with patients and providing referrals to the tobacco quitline, or (b) quitline materials delivered by mail. Both interventions advocated for pharmacy personnel to ask about tobacco use, advise patients who smoke to quit, and refer patients to the tobacco quitline for additional assistance with quitting. Study outcome measures include the number of quitline registrants who are referred by pharmacies (before and during the intervention period), the number of quitline materials distributed to patients, and self-reported behavior of cessation counseling and quitline referrals, assessed using written surveys completed by pharmacy personnel (pharmacists, technicians). Results Pharmacists (n=124) and pharmacy technicians (n=127), representing 64 participating pharmacies with equal numbers of retail chain and independently-owned pharmacies, participated in the study. Most pharmacists (67%) and half of pharmacy technicians (50%) indicated that they were “not at all” familiar with the tobacco quitline. During the baseline (pre-intervention) monitoring period, the quitline registered 120 patients (18 in CT and 102 in WA) who reported that they heard about the quitline from a pharmacy. Conclusion Novel tobacco intervention approaches are needed to capitalize on the community pharmacy’s frequent

  19. Image motion compensation by area correlation and centroid tracking of solar surface features

    International Nuclear Information System (INIS)

    Nein, M.E.; Mcintosh, W.R.; Cumings, N.P.

    1983-07-01

    An experimental solar correlation tracker was tested and evaluated on a ground-based solar magnetograph. Using sunspots as fixed targets, tracking error signals were derived by which the telescope image was stabilized against wind induced perturbations. Two methods of stabilization were investigated mechanical stabilization of the image by controlled two-axes motion of an active optical element in the telescope beam, and electronic stabilization by biasing of the electron scan in the recording camera. Both approaches have demonstrated telescope stability of about 0.6 arc sec under random perturbations which can cause the unstabilized image to move up to 120 arc sec at frequencies up to 30 Hz

  20. Image motion compensation by area correlation and centroid tracking of solar surface features

    Science.gov (United States)

    Nein, M. E.; Mcintosh, W. R.; Cumings, N. P.

    1983-01-01

    An experimental solar correlation tracker was tested and evaluated on a ground-based solar magnetograph. Using sunspots as fixed targets, tracking error signals were derived by which the telescope image was stabilized against wind induced perturbations. Two methods of stabilization were investigated; mechanical stabilization of the image by controlled two-axes motion of an active optical element in the telescope beam, and electronic stabilization by biasing of the electron scan in the recording camera. Both approaches have demonstrated telescope stability of about 0.6 arc sec under random perturbations which can cause the unstabilized image to move up to 120 arc sec at frequencies up to 30 Hz.

  1. Suppressing beam-centroid motion in a long-pulse linear induction accelerator

    Directory of Open Access Journals (Sweden)

    Carl Ekdahl

    2011-12-01

    Full Text Available The second axis of the dual-axis radiography of hydrodynamic testing (DARHT facility produces up to four radiographs within an interval of 1.6  μs. It does this by slicing four micropulses out of a 2-μs long electron beam pulse and focusing them onto a bremsstrahlung converter target. The 1.8-kA beam pulse is created by a dispenser cathode diode and accelerated to more than 16 MeV by the unique DARHT Axis-II linear induction accelerator (LIA. Beam motion in the accelerator would be a problem for multipulse flash radiography. High-frequency motion, such as from beam-breakup (BBU instability, would blur the individual spots. Low-frequency motion, such as produced by pulsed-power variation, would produce spot-to-spot differences. In this article, we describe these sources of beam motion, and the measures we have taken to minimize it. Using the methods discussed, we have reduced beam motion at the accelerator exit to less than 2% of the beam envelope radius for the high-frequency BBU, and less than 1/3 of the envelope radius for the low-frequency sweep.

  2. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    Science.gov (United States)

    Chin, Alexander W.; Herrera, Claudia Y.; Spivey, Natalie D.; Fladung, William A.; Cloutier, David

    2015-01-01

    The mass properties of an aerospace vehicle are required by multiple disciplines in the analysis and prediction of flight behavior. Pendulum oscillation methods have been developed and employed for almost a century as a means to measure mass properties. However, these oscillation methods are costly, time consuming, and risky. The NASA Armstrong Flight Research Center has been investigating the Dynamic Inertia Measurement, or DIM method as a possible alternative to oscillation methods. The DIM method uses ground test techniques that are already applied to aerospace vehicles when conducting modal surveys. Ground vibration tests would require minimal additional instrumentation and time to apply the DIM method. The DIM method has been validated on smaller test articles, but has not yet been fully proven on large aerospace vehicles.

  3. An Example of the Use of Research Methods and Findings as an Experiential Learning Exercise in an Accounting Theory Course

    Science.gov (United States)

    Bublitz, Bruce; Philipich, Kirk; Blatz, Robert

    2015-01-01

    The purpose of this teaching note is to describe an experiential learning exercise used in a master's level financial accounting theory course. The experiential exercise illustrates how order effects can affect user's judgments, a long-standing research finding. This experiential exercise was used in an attempt to make students more cognizant of…

  4. Experimental Validation of the Dynamic Inertia Measurement Method to Find the Mass Properties of an Iron Bird Test Article

    Science.gov (United States)

    Chin, Alexander; Herrera, Claudia; Spivey, Natalie; Fladung, William; Cloutier, David

    2015-01-01

    This presentation describes the DIM method and how it measures the inertia properties of an object by analyzing the frequency response functions measured during a ground vibration test (GVT). The DIM method has been in development at the University of Cincinnati and has shown success on a variety of small scale test articles. The NASA AFRC version was modified for larger applications.

  5. For a reasoned development of experimental methods in information and communication sciences Some epistemological findings of methodological pluralism

    Directory of Open Access Journals (Sweden)

    Didier COURBET

    2013-07-01

    Full Text Available If multidisciplinarity is necessary, first, for studying the widest possible set of communication phenomena (organizational, in groups, interpersonal, media, computer-mediated communication... and, secondly, for grasping the complexity of the different moments of the same phenomenon of communication (production, content, reception, circulation ..., methodological pluralism is also important. However, French research in communication sciences leaves in the shade a number of phenomena and moments of communication that could be better understood thanks to the experimental method. We will underline that the epistemological issues related to rational use of the experimental method in communication sciences are not negligible: it allows the study of objects that cannot be investigated with other methods and offers the opportunity to build knowledge by the refutation of hypotheses and theoretical propositions. We will clarify some epistemological misunderstandings concerning this method. First, it is actually a method of studying complex systems and communication processes. Secondly, its use is not incompatible with constructivism.

  6. Method of transient identification based on a possibilistic approach, optimized by genetic algorithm

    International Nuclear Information System (INIS)

    Almeida, Jose Carlos Soares de

    2001-02-01

    This work develops a method for transient identification based on a possible approach, optimized by Genetic Algorithm to optimize the number of the centroids of the classes that represent the transients. The basic idea of the proposed method is to optimize the partition of the search space, generating subsets in the classes within a partition, defined as subclasses, whose centroids are able to distinguish the classes with the maximum correct classifications. The interpretation of the subclasses as fuzzy sets and the possible approach provided a heuristic to establish influence zones of the centroids, allowing to achieve the 'don't know' answer for unknown transients, that is, outside the training set. (author)

  7. Ce3+ 5d-centroid shift and vacuum referred 4f-electron binding energies of all lanthanide impurities in 150 different compounds

    International Nuclear Information System (INIS)

    Dorenbos, Pieter

    2013-01-01

    A review on the wavelengths of all five 4f–5d transitions for Ce 3+ in about 150 different inorganic compounds (fluorides, chlorides, bromides, iodides, oxides, sulfides, selenides, nitrides) is presented. It provides data on the centroid shift and the crystal field splitting of the 5d-configuration which are then used to estimate the Eu 2+ inter 4f-electron Coulomb repulsion energy U(6,A) in compound A. The four semi-empirical models (the redshift model, the centroid shift model, the charge transfer model, and the chemical shift model) on lanthanide levels that were developed past 12 years are briefly reviewed. It will be demonstrated how those models together with the collected data of this work and elsewhere can be united to construct schemes that contain the binding energy of electrons in the 4f and 5d states for each divalent and each trivalent lanthanide ion relative to the vacuum energy. As example the vacuum referred binding energy schemes for LaF 3 and La 2 O 3 will be constructed. - Highlights: ► An compilation on all five Ce 3+ 4f–5d energies in 150 inorganic compounds is presented. ► The relationship between the 5d centroid shift and host cation electronegativity id demonstrated. ► The electronic structure scheme of the lanthanides in La 2 O 3 and LaF 3 is presented.

  8. Simulation of plume rise: Study the effect of stably stratified turbulence layer on the rise of a buoyant plume from a continuous source by observing the plume centroid

    Science.gov (United States)

    Bhimireddy, Sudheer Reddy; Bhaganagar, Kiran

    2016-11-01

    Buoyant plumes are common in atmosphere when there exists a difference in temperature or density between the source and its ambience. In a stratified environment, plume rise happens until the buoyancy variation exists between the plume and ambience. In a calm no wind ambience, this plume rise is purely vertical and the entrainment happens because of the relative motion of the plume with ambience and also ambient turbulence. In this study, a plume centroid is defined as the plume mass center and is calculated from the kinematic equation which relates the rate of change of centroids position to the plume rise velocity. Parameters needed to describe the plume are considered as the plume radius, plumes vertical velocity and local buoyancy of the plume. The plume rise velocity is calculated by the mass, momentum and heat conservation equations in their differential form. Our study focuses on the entrainment velocity, as it depicts the extent of plume growth. This entrainment velocity is made up as sum of fractions of plume's relative velocity and ambient turbulence. From the results, we studied the effect of turbulence on the plume growth by observing the variation in the plume radius at different heights and the centroid height reached before loosing its buoyancy.

  9. How do clinical genetics consent forms address the familial approach to confidentiality and incidental findings? A mixed-methods study.

    Science.gov (United States)

    Dheensa, Sandi; Crawford, Gillian; Salter, Claire; Parker, Michael; Fenwick, Angela; Lucassen, Anneke

    2018-01-01

    Genetic test results can be relevant to patients and their relatives. Questions thus arise around whether clinicians regard genetic information as confidential to individuals or to families, and about how they broach this and other issues, including the potential for incidental findings, in consent (forms) for genetic testing. We conducted a content analysis of UK-wide genetic testing consent forms and interviewed 128 clinicians/laboratory scientists. We found that almost all genetic services offered patients multiple, sometimes unworkable, choices on forms, including an option to veto the use of familial genetic information to benefit relatives. Participants worried that documented choices were overriding professional judgement and cautioned against any future forms dictating practice around incidental findings. We conclude that 'tick-box' forms, which do little to enhance autonomy, are masking valid consent processes in clinical practice. As genome-wide testing becomes commonplace, we must re-consider consent processes, so that they protects patients'-and relatives'-interests.

  10. Radiographic localization of unerupted teeth: further findings about the vertical tube shift method and other localization techniques.

    Science.gov (United States)

    Jacobs, S G

    2000-10-01

    The parallax method (image/tube shift method, Clark's rule, Richards' buccal object rule) is recommended to localize unerupted teeth. Richards' contribution to the development of the parallax method is discussed. The favored method for localization uses a rotational panoramic radiograph in combination with an occlusal radiograph involving a vertical shift of the x-ray tube. The use of this combination when localizing teeth and supernumeraries in the premolar region is illustrated. When taking an occlusal radiograph to localize an unerupted maxillary canine, clinical situations are presented where modification of the vertical angulation of the tube of 70 degrees to 75 degrees or of the horizontal position of the tube is warranted. The limitations of axial (true, cross-sectional, vertex) occlusal radiographs are also explored.

  11. A new generalized exponential rational function method to find exact special solutions for the resonance nonlinear Schrödinger equation

    Science.gov (United States)

    Ghanbari, Behzad; Inc, Mustafa

    2018-04-01

    The present paper suggests a novel technique to acquire exact solutions of nonlinear partial differential equations. The main idea of the method is to generalize the exponential rational function method. In order to examine the ability of the method, we consider the resonant nonlinear Schrödinger equation (R-NLSE). Many variants of exact soliton solutions for the equation are derived by the proposed method. Physical interpretations of some obtained solutions is also included. One can easily conclude that the new proposed method is very efficient and finds the exact solutions of the equation in a relatively easy way.

  12. Tomography methods for diagnostic examination of cerebrovascular disease: a comparative evaluation of SPECT, PET and MR/CT findings

    International Nuclear Information System (INIS)

    Reiche, W.; Kaiser, H.J.; Weiller, C.; Altehoefer, C.; Buell, U.; Isensee, C.

    1991-01-01

    Single Photon Emissions Computerized Tomography (SPECT), Positron Emissions Tomography (PET), Magnetic Resonance Tomography (MR), and Transmission Computerized Tomography (CT) complement each other and lead to a consideration of the cerebrovascular disease under patho-physiological aspects. Indications for the combined application of functionally oriented (SPECT/PET) and morphologically oriented (CT/MR) examination methods with cerebrovascular disease are presented. (orig./MG) [de

  13. The Continuing Search to Find a More Effective and Less Intimidating Way to Teach Research Methods in Higher Education

    Science.gov (United States)

    Bell, Robin

    2016-01-01

    Existing literature examining the teaching of research methods highlights difficulties students face when developing research competencies. Studies of student-centred teaching approaches have found increased student performance and improved confidence in undertaking research projects. To develop a student-centred approach, it could be beneficial…

  14. A genetic-algorithm-based method to find unitary transformations for any desired quantum computation and application to a one-bit oracle decision problem

    Energy Technology Data Exchange (ETDEWEB)

    Bang, Jeongho [Seoul National University, Seoul (Korea, Republic of); Hanyang University, Seoul (Korea, Republic of); Yoo, Seokwon [Hanyang University, Seoul (Korea, Republic of)

    2014-12-15

    We propose a genetic-algorithm-based method to find the unitary transformations for any desired quantum computation. We formulate a simple genetic algorithm by introducing the 'genetic parameter vector' of the unitary transformations to be found. In the genetic algorithm process, all components of the genetic parameter vectors are supposed to evolve to the solution parameters of the unitary transformations. We apply our method to find the optimal unitary transformations and to generalize the corresponding quantum algorithms for a realistic problem, the one-bit oracle decision problem, or the often-called Deutsch problem. By numerical simulations, we can faithfully find the appropriate unitary transformations to solve the problem by using our method. We analyze the quantum algorithms identified by the found unitary transformations and generalize the variant models of the original Deutsch's algorithm.

  15. Finding Relevant Parameters for the Thin-film Photovoltaic Cells Production Process with the Application of Data Mining Methods.

    Science.gov (United States)

    Ulaczyk, Jan; Morawiec, Krzysztof; Zabierowski, Paweł; Drobiazg, Tomasz; Barreau, Nicolas

    2017-09-01

    A data mining approach is proposed as a useful tool for the control parameters analysis of the 3-stage CIGSe photovoltaic cell production process, in order to find variables that are the most relevant for cell electric parameters and efficiency. The analysed data set consists of stage duration times, heater power values as well as temperatures for the element sources and the substrate - there are 14 variables per sample in total. The most relevant variables of the process have been found based on the so-called random forest analysis with the application of the Boruta algorithm. 118 CIGSe samples, prepared at Institut des Matériaux Jean Rouxel, were analysed. The results are close to experimental knowledge on the CIGSe cells production process. They bring new evidence to production parameters of new cells and further research. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Method for finding the distribution function of the ions formed in an electrode sheath in a plasma

    International Nuclear Information System (INIS)

    Chumenkov, V.

    1981-01-01

    A steady-state one-dimensional kinetic equation is studied for the ions formed in an electrode sheath in a discharge in a transverse magnetic field and also in the ionization--acceleration zone of Hall accelerators. Only single ionization of atoms by electron impact is considered in the collision term on the right side of the equation. The variables which appear on the right side are grouped into an expression which is a measure of the ion energy distribution. The problem is solved through the use of an empirical expression for the integrated ion energy distribution. This approach for finding the ion distribution function makes it a comparatively simple matter to trace the evolution of the distribution function due to changes in the external parameters (the magnetic field, the discharge voltage, and the pressure) or in the geometric characteristics of the discharge apparatus

  17. Paediatric cardiac CT examinations: impact of the iterative reconstruction method ASIR on image quality--preliminary findings.

    Science.gov (United States)

    Miéville, Frédéric A; Gudinchet, François; Rizzo, Elena; Ou, Phalla; Brunelle, Francis; Bochud, François O; Verdun, Francis R

    2011-09-01

    Radiation dose exposure is of particular concern in children due to the possible harmful effects of ionizing radiation. The adaptive statistical iterative reconstruction (ASIR) method is a promising new technique that reduces image noise and produces better overall image quality compared with routine-dose contrast-enhanced methods. To assess the benefits of ASIR on the diagnostic image quality in paediatric cardiac CT examinations. Four paediatric radiologists based at two major hospitals evaluated ten low-dose paediatric cardiac examinations (80 kVp, CTDI(vol) 4.8-7.9 mGy, DLP 37.1-178.9 mGy·cm). The average age of the cohort studied was 2.6 years (range 1 day to 7 years). Acquisitions were performed on a 64-MDCT scanner. All images were reconstructed at various ASIR percentages (0-100%). For each examination, radiologists scored 19 anatomical structures using the relative visual grading analysis method. To estimate the potential for dose reduction, acquisitions were also performed on a Catphan phantom and a paediatric phantom. The best image quality for all clinical images was obtained with 20% and 40% ASIR (p ASIR above 50%, image quality significantly decreased (p ASIR, a strong noise-free appearance of the structures reduced image conspicuity. A potential for dose reduction of about 36% is predicted for a 2- to 3-year-old child when using 40% ASIR rather than the standard filtered back-projection method. Reconstruction including 20% to 40% ASIR slightly improved the conspicuity of various paediatric cardiac structures in newborns and children with respect to conventional reconstruction (filtered back-projection) alone.

  18. An econometric method for estimating population parameters from non-random samples: An application to clinical case finding.

    Science.gov (United States)

    Burger, Rulof P; McLaren, Zoë M

    2017-09-01

    The problem of sample selection complicates the process of drawing inference about populations. Selective sampling arises in many real world situations when agents such as doctors and customs officials search for targets with high values of a characteristic. We propose a new method for estimating population characteristics from these types of selected samples. We develop a model that captures key features of the agent's sampling decision. We use a generalized method of moments with instrumental variables and maximum likelihood to estimate the population prevalence of the characteristic of interest and the agents' accuracy in identifying targets. We apply this method to tuberculosis (TB), which is the leading infectious disease cause of death worldwide. We use a national database of TB test data from South Africa to examine testing for multidrug resistant TB (MDR-TB). Approximately one quarter of MDR-TB cases was undiagnosed between 2004 and 2010. The official estimate of 2.5% is therefore too low, and MDR-TB prevalence is as high as 3.5%. Signal-to-noise ratios are estimated to be between 0.5 and 1. Our approach is widely applicable because of the availability of routinely collected data and abundance of potential instruments. Using routinely collected data to monitor population prevalence can guide evidence-based policy making. Copyright © 2017 John Wiley & Sons, Ltd.

  19. An Innovative Method of Measuring Changes in Access to Healthful Foods in School Lunch Programs: Findings from a Pilot Evaluation.

    Directory of Open Access Journals (Sweden)

    Allison P Hawkes

    Full Text Available A large local health department in Colorado partnered with 15 school districts to develop an approach to evaluate changes in access to healthy foods in reimbursable school lunches and a la carte offerings.School district nutrition managers were engaged at the start of this project. Health department dietitians developed criteria to classify food items as "Lower Fat and less added Sugar" (LFS and "Higher Fat and more added Sugar" (HFS based on the percentage of calories from fat and grams of added sugar. Lunch production sheets were obtained for two time periods, food items and the number of planned servings recorded. LFS and HFS planned servings were summed for each time period, and a LFS to HFS ratio calculated by dividing LFS planned servings by HFS planned servings. Additional analyses included calculating LFS: HFS ratios by school district, and for a la carte offerings.In 2009, the LFS: HFS ratio was 2.08, in 2011, 3.71 (P<0.0001. The method also detected changes in ratios at the school district level. For a la carte items, in 2009 the ratio of LFS: HFS was 0.53, and in 2011, 0.61 (not statistically significant.This method detected an increase in the LFS: HFS ratio over time and demonstrated that the school districts improved access to healthful food/drink by changing the contents of reimbursable school lunches. The evaluation method discussed here can generate information that districts can use in helping sustain and expand their efforts to create healthier environments for children and adults. Although federal regulations now cover all food and beverages served during the school day, there are still opportunities to improve and measure changes in food served in other settings such as child care centers, youth correction facilities, or in schools not participating in the National School Lunch Program.

  20. Characterization of a millefiori glass find from Aquincum by SEM-EDX and micro-PIXE methods

    International Nuclear Information System (INIS)

    Uzonyi, I.; Csontos, K.; Verebes, A.; Cserhati, C.; Csedreki, L.; Kis-Varga, M.; Kiss, A.Z.

    2011-01-01

    Research has been focused on the analysis of archaeological glasses from the Roman age and medieval times. Study of ancient millefiori type glasses from the collection of Hungarian Museums has been started. A test measurement, carried out on a glass fragment supposedly part of a dish, was performed by SEM-EDX and micro-PIXE methods. Complementary analytical data were obtained for texture and composition. Results suggest that Roman and Mesopotamian techniques were used together. Our data contribute to data bases of millefiori glasses.

  1. Characterization of a millefiori glass find from Aquincum by SEM-EDX and micro-PIXE methods

    Energy Technology Data Exchange (ETDEWEB)

    Uzonyi, I., E-mail: uzonyi@atomki.hu [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary); Csontos, K.; Verebes, A. [Budapest History Museum, Aquincum Museum H-8211 Budapest, Zahony u. 4. (Hungary); Cserhati, C. [Department of Solid State Physics, University of Debrecen H-4032 Debrecen, Bem ter 18/B (Hungary); Csedreki, L.; Kis-Varga, M.; Kiss, A.Z. [Institute of Nuclear Research of the Hungarian Academy of Sciences, H-4026 Debrecen, Bem ter 18/C (Hungary)

    2011-10-15

    Research has been focused on the analysis of archaeological glasses from the Roman age and medieval times. Study of ancient millefiori type glasses from the collection of Hungarian Museums has been started. A test measurement, carried out on a glass fragment supposedly part of a dish, was performed by SEM-EDX and micro-PIXE methods. Complementary analytical data were obtained for texture and composition. Results suggest that Roman and Mesopotamian techniques were used together. Our data contribute to data bases of millefiori glasses.

  2. Consumer Attitudes and Perceptions on mHealth Privacy and Security: Findings From a Mixed-Methods Study.

    Science.gov (United States)

    Atienza, Audie A; Zarcadoolas, Christina; Vaughon, Wendy; Hughes, Penelope; Patel, Vaishali; Chou, Wen-Ying Sylvia; Pritts, Joy

    2015-01-01

    This study examined consumers' attitudes and perceptions regarding mobile health (mHealth) technology use in health care. Twenty-four focus groups with 256 participants were conducted in 5 geographically diverse locations. Participants were also diverse in age, education, race/ethnicity, gender, and rural versus urban settings. Several key themes emerged from the focus groups. Findings suggest that consumer attitudes regarding mHealth privacy/security are highly contextualized, with concerns depending on the type of information being communicated, where and when the information is being accessed, who is accessing or seeing the information, and for what reasons. Consumers frequently considered the tradeoffs between the privacy/security of using mHealth technologies and the potential benefits. Having control over mHealth privacy/security features and trust in providers were important issues for consumers. Overall, this study found significant diversity in attitudes regarding mHealth privacy/security both within and between traditional demographic groups. Thus, to address consumers' concerns regarding mHealth privacy and security, a one-size-fits-all approach may not be adequate. Health care providers and technology developers should consider tailoring mHealth technology according to how various types of information are communicated in the health care setting, as well as according to the comfort, skills, and concerns individuals may have with mHealth technology.

  3. Interwoven histories: Mental health nurses with experience of mental illness, qualitative findings from a mixed methods study.

    Science.gov (United States)

    Oates, Jennifer; Drey, Nicholas; Jones, Julia

    2018-02-15

    The effects of mental health nurses' own experience of mental illness or being a carer have rarely been researched beyond the workplace setting. This study aimed to explore how the experience of mental illness affects mental health nurses' lives outside of and inside work. A sample of 26 mental health nurses with personal experience of mental illness took part in semistructured interviews. Data were analysed thematically using a six-phase approach. The analysis revealed the broad context of nurses' experiences of mental illness according to three interwoven themes: mental illness as part of family life; experience of accessing services; and life interwoven with mental illness. Participants typically described personal and familial experience of mental illness across their life course, with multiple causes and consequences. The findings suggest that nurses' lives outside of work should be taken into account when considering the impact of their personal experience of mental illness. Similarly being a nurse influences how mental illness is experienced. Treatment of nurses with mental illness should account for their nursing expertise whilst recognizing that the context for nurses' mental illness could be much broader than the effect of workplace stress. © 2018 Australian College of Mental Health Nurses Inc.

  4. Diagnostic methods in finding out the causes of infertility, results of HSG examination and laparoscopy in infertile women examined at the Gynecological Ward of the City Hospital

    International Nuclear Information System (INIS)

    Kwasniewski, S.; Kukulski, P.; Szymanski, J.; Kwasniewska, A.

    1993-01-01

    The paper presents diagnostic methods and the results of hysterosalpingography (HSG) and laparoscopy examination, with special attention being drawn to the usefulness of these methods in finding out the causes of infertility. 51 patients with primary and second infertility were examined. HSG and laparoscopy make it possible to diagnose correctly the cause of infertility. They also enable adequate and early classification of patients for further diagnosis and treatment at highly specialized centers dealing with the problems of infertility. (author)

  5. Ongoing challenges to finding people with Parkinson's disease for epidemiological studies: a comparison of population-level case ascertainment methods.

    Science.gov (United States)

    Harris, M Anne; Koehoorn, Mieke; Teschke, Kay

    2011-07-01

    Locating Parkinson's disease cases for epidemiological studies has long been challenging. Self reports, secondary records of physician diagnosis and drug tracer methods each exhibit known disadvantages but have rarely been compared directly. Prescriptions of levodopa have in some studies been considered to comprise a reasonable proxy for Parkinson's disease diagnosis. We tested this assumption by comparing three methods of population-level case ascertainment. We compared the number of Parkinson's disease cases in British Columbia derived from self-reports in the 2001 Canadian Community Health Survey to those obtained from administrative records of filled levodopa prescriptions and to Parkinson's disease diagnoses from physician visit billing and hospital discharge records in 1996 and 2005. We directly compared a case definition based on levodopa prescriptions with a definition based on records of physician diagnosis by calculating positive predictive value and sensitivity. Crude prevalence estimates ranged from approximately 100 to 200 per 100,000. Levodopa-based case definitions overestimated prevalence, while physician- and hospital-record-based case definitions provided lower prevalence estimates compared to survey derived estimates. The proportion of levodopa users with a diagnosis of Parkinson's disease declined from 62% to 52% between 1996 and 2005. This decrease was most dramatic among women (64%-44%) and those under age 65 (54%-39%). Sex and age trends suggest increasing use of levodopa among patients with conditions other than Parkinson's disease, such as restless legs syndrome. Increased non-Parkinson's levodopa use decreases the efficiency of levodopa as a Parkinson's disease case tracer. Copyright © 2011 Elsevier Ltd. All rights reserved.

  6. Finding out who is nesting where: a method for locating nest sites of hole-nesting species prior to egg laying

    NARCIS (Netherlands)

    Grieco, F.

    2000-01-01

    A method to find out which species is more likely to start egg laying in a certain nestbox is described. Nestboxes were visited daily and the behaviour of the birds (Great, Blue and Coal Tits) that appeared around the nestbox was observed. The birds' response consisted mainly of giving alarm calls

  7. The TIMSS Videotape Classroom Study: Methods and Findings from an Exploratory Research Project on Eighth-Grade Mathematics Instruction in Germany, Japan, and the United States.

    Science.gov (United States)

    Stigler, James W.; Gonzales, Patrick; Kawanaka, Takako; Knoll, Steffen; Serrano, Ana

    1999-01-01

    Describes the methods and preliminary findings of the Videotape Classroom Study, a video survey of eighth-grade mathematics lessons in Germany, Japan, and the United States. Part of the Third International Mathematics and Science study, this research project is the first study of videotaped records from national probability samples. (SLD)

  8. The application of infrared chemical imaging to the detection and enhancement of latent fingerprints: method optimization and further findings.

    Science.gov (United States)

    Tahtouh, Mark; Despland, Pauline; Shimmon, Ronald; Kalman, John R; Reedy, Brian J

    2007-09-01

    Fourier transform infrared (FTIR) chemical imaging allows the collection of fingerprint images from backgrounds that have traditionally posed problems for conventional fingerprint detection methods. In this work, the suitability of this technique for the imaging of fingerprints on a wider range of difficult surfaces (including polymer banknotes, various types of paper, and aluminum drink cans) has been tested. For each new surface, a systematic methodology was employed to optimize settings such as spectral resolution, number of scans, and pixel aggregation in order to reduce collection time and file-size without compromising spatial resolution and the quality of the final fingerprint image. The imaging of cyanoacrylate-fumed fingerprints on polymer banknotes has been improved, with shorter collection times for larger image areas. One-month-old fingerprints on polymer banknotes have been successfully fumed and imaged. It was also found that FTIR chemical imaging gives high quality images of cyanoacrylate-fumed fingerprints on aluminum drink cans, regardless of the printed background. Although visible and UV light sources do not yield fingerprint images of the same quality on difficult, nonporous backgrounds, in many cases they can be used to locate a fingerprint prior to higher quality imaging by the FTIR technique. Attempts to acquire FTIR images of fingerprints on paper-based porous surfaces that had been treated with established reagents such as ninhydrin were all unsuccessful due to the swamping effect of the cellulose constituents of the paper.

  9. The Tourette International Collaborative Genetics (TIC Genetics) study, finding the genes causing Tourette syndrome: objectives and methods.

    Science.gov (United States)

    Dietrich, Andrea; Fernandez, Thomas V; King, Robert A; State, Matthew W; Tischfield, Jay A; Hoekstra, Pieter J; Heiman, Gary A

    2015-02-01

    Tourette syndrome (TS) is a neuropsychiatric disorder characterized by recurrent motor and vocal tics, often accompanied by obsessive-compulsive disorder and/or attention-deficit/hyperactivity disorder. While the evidence for a genetic contribution is strong, its exact nature has yet to be clarified fully. There is now mounting evidence that the genetic risks for TS include both common and rare variants and may involve complex multigenic inheritance or, in rare cases, a single major gene. Based on recent progress in many other common disorders with apparently similar genetic architectures, it is clear that large patient cohorts and open-access repositories will be essential to further advance the field. To that end, the large multicenter Tourette International Collaborative Genetics (TIC Genetics) study was established. The goal of the TIC Genetics study is to undertake a comprehensive gene discovery effort, focusing both on familial genetic variants with large effects within multiply affected pedigrees and on de novo mutations ascertained through the analysis of apparently simplex parent-child trios with non-familial tics. The clinical data and biomaterials (DNA, transformed cell lines, RNA) are part of a sharing repository located within the National Institute for Mental Health Center for Collaborative Genomics Research on Mental Disorders, USA, and will be made available to the broad scientific community. This resource will ultimately facilitate better understanding of the pathophysiology of TS and related disorders and the development of novel therapies. Here, we describe the objectives and methods of the TIC Genetics study as a reference for future studies from our group and to facilitate collaboration between genetics consortia in the field of TS.

  10. Numerical methods for finding periodic points in discrete maps. High order islands chains and noble barriers in a toroidal magnetic configuration

    Energy Technology Data Exchange (ETDEWEB)

    Steinbrecher, G. [Association Euratom-Nasti Romania, Dept. of Theoretical Physics, Physics Faculty, University of Craiova (Romania); Reuss, J.D.; Misguich, J.H. [Association Euratom-CEA Cadarache, 13 - Saint-Paul-lez-Durance (France). Dept. de Recherches sur la Fusion Controlee

    2001-11-01

    We first remind usual physical and mathematical concepts involved in the dynamics of Hamiltonian systems, and namely in chaotic systems described by discrete 2D maps (representing the intersection points of toroidal magnetic lines in a poloidal plane in situations of incomplete magnetic chaos in Tokamaks). Finding the periodic points characterizing chains of magnetic islands is an essential step not only to determine the skeleton of the phase space picture, but also to determine the flux of magnetic lines across semi-permeable barriers like Cantori. We discuss here several computational methods used to determine periodic points in N dimensions, which amounts to solve a set of N nonlinear coupled equations: Newton method, minimization techniques, Laplace or steepest descend method, conjugated direction method and Fletcher-Reeves method. We have succeeded to improve this last method in an important way, without modifying its useful double-exponential convergence. This improved method has been tested and applied to finding periodic points of high order m in the 2D 'Tokamap' mapping, for values of m along rational chains of winding number n/m converging towards a noble value where a Cantorus exists. Such precise positions of periodic points have been used in the calculation of the flux across this Cantorus. (authors)

  11. Automatic NC-Data generation method for 5-axis cutting of turbine-blades by finding Safe heel-angles and adaptive path-intervals

    International Nuclear Information System (INIS)

    Piao, Cheng Dao; Lee, Cheol Soo; Cho, Kyu Zong; Park, Gwang Ryeol

    2004-01-01

    In this paper, an efficient method for generating 5-axis cutting data for a turbine blade is presented. The interference elimination of 5-axis cutting currently is very complicated, and it takes up a lot of time. The proposed method can generate an interference-free tool path, within an allowance range. Generating the cutting data just point to the cutting process and using it to obtain NC data by calculating the feed rate, allows us to maintain the proper feed rate of the 5-axis machine. This paper includes the algorithms for: (1) CL data generation by detecting an interference-free heel angle, (2) finding the optimal tool path interval considering the cusp-height, (3) finding the adaptive feed rate values for each cutter path, and (4) the inverse kinematics depending on the structure of the 5-axis machine, for generating the NC data

  12. Experimental Test of Data Analysis Methods from Staggered Pair X-ray Beam Position Monitors at Bending Magnet Beamlines

    Science.gov (United States)

    Buth, G.; Huttel, E.; Mangold, S.; Steininger, R.; Batchelor, D.; Doyle, S.; Simon, R.

    2013-03-01

    Different methods have been proposed to calculate the vertical position of the photon beam centroid from the four blade currents of staggered pair X-ray beam position monitors (XBPMs) at bending magnet beamlines since they emerged about 15 years ago. The original difference-over-sum method introduced by Peatman and Holldack is still widely used, even though it has been proven to be rather inaccurate at large beam displacements. By systematically generating bumps in the electron orbit of the ANKA storage ring and comparing synchronized data from electron BPMs and XBPM blade currents, we have been able to show that the log-ratio method by S. F. Lin, B.G. Sun et al. is superior (meaning the characteristic being closer to linear) to the ratio method, which in turn is superior to the difference over sum method. These findings are supported by simulations of the XBPM response to changes of the beam centroid. The heuristic basis for each of the methods is investigated. The implications on using XBPM readings for orbit correction are discussed

  13. The impact of the in-orbit background and the X-ray source intensity on the centroiding accuracy of the Swift X-ray telescope

    CERN Document Server

    Ambrosi, R M; Hill, J; Cheruvu, C; Abbey, A F; Short, A D T

    2002-01-01

    The optical components of the Swift Gamma Ray Burst Explorer X-ray Telescope (XRT), consisting of the JET-X spare flight mirror and a charge coupled device of the type used in the EPIC program, were used in a re-calibration study carried out at the Panter facility, which is part of the Max Planck Institute for Extraterrestrial Physics. The objective of this study was to check the focal length and the off axis performance of the mirrors and to show that the half energy width (HEW) of the on-axis point spread function (PSF) was of the order of 16 arcsec at 1.5 keV (Nucl. Instr. and Meth. A 488 (2002) 543; SPIE 4140 (2000) 64) and that a centroiding accuracy better that 1 arcsec could be achieved within the 4 arcmin sampling area designated by the Burst Alert Telescope (Nucl. Instr. and Meth. A 488 (2002) 543). The centroiding accuracy of the Swift XRT's optical components was tested as a function of distance from the focus and off axis position of the PSF (Nucl. Instr. and Meth. A 488 (2002) 543). The presence ...

  14. A new method for finding the minimum free energy pathway of ions and small molecule transportation through protein based on 3D-RISM theory and the string method

    Science.gov (United States)

    Yoshida, Norio

    2018-05-01

    A new method for finding the minimum free energy pathway (MFEP) of ions and small molecule transportation through a protein based on the three-dimensional reference interaction site model (3D-RISM) theory combined with the string method has been proposed. The 3D-RISM theory produces the distribution function, or the potential of mean force (PMF), for transporting substances around the given protein structures. By applying the string method to the PMF surface, one can readily determine the MFEP on the PMF surface. The method has been applied to consider the Na+ conduction pathway of channelrhodopsin as an example.

  15. A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Xiu-Hua; Ling, Jian, E-mail: lingjian@ynu.edu.cn; Peng, Jun; Cao, Qiu-E., E-mail: qecao@ynu.edu.cn; Ding, Zhong-Tao; Bian, Long-Chun

    2013-10-10

    Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis.

  16. A colorimetric method for highly sensitive and accurate detection of iodide by finding the critical color in a color change process using silver triangular nanoplates

    International Nuclear Information System (INIS)

    Yang, Xiu-Hua; Ling, Jian; Peng, Jun; Cao, Qiu-E.; Ding, Zhong-Tao; Bian, Long-Chun

    2013-01-01

    Graphical abstract: -- Highlights: •Demonstrated a new colorimetric strategy for iodide detection by silver nanoplates. •The colorimetric strategy is to find the critical color in a color change process. •The colorimetric strategy is more accurate and sensitive than common colorimetry. •Discovered a new morphological transformation phenomenon of silver nanoplates. -- Abstract: In this contribution, we demonstrated a novel colorimetric method for highly sensitive and accurate detection of iodide using citrate-stabilized silver triangular nanoplates (silver TNPs). Very lower concentration of iodide can induce an appreciable color change of silver TNPs solution from blue to yellow by fusing of silver TNPs to nanoparticles, as confirmed by UV–vis absorption spectroscopy and transmission electron microscopy (TEM). The principle of this colorimetric assay is not an ordinary colorimetry, but a new colorimetric strategy by finding the critical color in a color change process. With this strategy, 0.1 μM of iodide can be recognized within 30 min by naked-eyes observation, and lower concentration of iodide down to 8.8 nM can be detected using a spectrophotometer. Furthermore, this high sensitive colorimetric assay has good accuracy, stability and reproducibility comparing with other ordinary colorimetry. We believe this new colorimetric method will open up a fresh insight of simple, rapid and reliable detection of iodide and can find its future application in the biochemical analysis or clinical diagnosis

  17. Global pathways to men's caregiving: mixed methods findings from the International Men and Gender Equality Survey and the Men Who Care study.

    Science.gov (United States)

    Kato-Wallace, Jane; Barker, Gary; Eads, Marci; Levtov, Ruti

    2014-01-01

    Promoting men's participation in unpaid care work is part of the Programme of Action for the International Conference on Population and Development. However, men's involvement in care work does not mirror the advances women have made in paid work outside the home. This mixed method study explores which men are more involved in caregiving, and what childhood and adulthood factors influence their level of involvement. Quantitative research presents findings from 1169 men across six countries with children aged 0-4, and a qualitative study presents findings from in-depth interviews with 83 men engaged in atypical caregiving practices. Survey research finds that being taught to care for children, witnessing one's father take care of one's siblings, respondents' present attitudes about gender equality and having outside help (or none, in some cases) were all also associated with men's higher level of involvement. Qualitative research reveals that men's experiences of violence, the normalisation of domestic work as children and life circumstances rather than greater-than-average beliefs in gender equality all propelled them into care work. Findings suggest that engaging more men into care work implies changes to policies and structural realities in the workplace coupled with changing gender attitudes. These insights inform policy and practice aimed at promoting greater involvement in care work by men.

  18. A comparison of three clustering methods for finding subgroups in MRI, SMS or clinical data: SPSS TwoStep Cluster analysis, Latent Gold and SNOB.

    Science.gov (United States)

    Kent, Peter; Jensen, Rikke K; Kongsted, Alice

    2014-10-02

    There are various methodological approaches to identifying clinically important subgroups and one method is to identify clusters of characteristics that differentiate people in cross-sectional and/or longitudinal data using Cluster Analysis (CA) or Latent Class Analysis (LCA). There is a scarcity of head-to-head comparisons that can inform the choice of which clustering method might be suitable for particular clinical datasets and research questions. Therefore, the aim of this study was to perform a head-to-head comparison of three commonly available methods (SPSS TwoStep CA, Latent Gold LCA and SNOB LCA). The performance of these three methods was compared: (i) quantitatively using the number of subgroups detected, the classification probability of individuals into subgroups, the reproducibility of results, and (ii) qualitatively using subjective judgments about each program's ease of use and interpretability of the presentation of results.We analysed five real datasets of varying complexity in a secondary analysis of data from other research projects. Three datasets contained only MRI findings (n = 2,060 to 20,810 vertebral disc levels), one dataset contained only pain intensity data collected for 52 weeks by text (SMS) messaging (n = 1,121 people), and the last dataset contained a range of clinical variables measured in low back pain patients (n = 543 people). Four artificial datasets (n = 1,000 each) containing subgroups of varying complexity were also analysed testing the ability of these clustering methods to detect subgroups and correctly classify individuals when subgroup membership was known. The results from the real clinical datasets indicated that the number of subgroups detected varied, the certainty of classifying individuals into those subgroups varied, the findings had perfect reproducibility, some programs were easier to use and the interpretability of the presentation of their findings also varied. The results from the artificial datasets

  19. Evidence-informed health policy 1 – Synthesis of findings from a multi-method study of organizations that support the use of research evidence

    Directory of Open Access Journals (Sweden)

    Moynihan Ray

    2008-12-01

    Full Text Available Abstract Background Organizations have been established in many countries and internationally to support the use of research evidence by producing clinical practice guidelines, undertaking health technology assessments, and/or directly supporting the use of research evidence in developing health policy on an international, national, and state or provincial level. Learning from these organizations can reduce the need to 'reinvent the wheel' and inform decisions about how best to organize support for such organizations, particularly in low- and middle-income countries (LMICs. Methods We undertook a multi-method study in three phases – a survey, interviews, and case descriptions that drew on site visits – and in each of the second and third phases we focused on a purposive sample of those involved in the previous phase. We used the seven main recommendations that emerged from the advice offered in the interviews to organize much of the synthesis of findings across phases and methods. We used a constant comparative method to identify themes from across phases and methods. Results Seven recommendations emerged for those involved in establishing or leading organizations that support the use of research evidence in developing health policy: 1 collaborate with other organizations; 2 establish strong links with policymakers and involve stakeholders in the work; 3 be independent and manage conflicts of interest among those involved in the work; 4 build capacity among those working in the organization; 5 use good methods and be transparent in the work; 6 start small, have a clear audience and scope, and address important questions; and 7 be attentive to implementation considerations, even if implementation is not a remit. Four recommendations emerged for the World Health Organization (WHO and other international organizations and networks: 1 support collaborations among organizations; 2 support local adaptation efforts; 3 mobilize support; and 4 create

  20. Evidence-informed health policy 1 - synthesis of findings from a multi-method study of organizations that support the use of research evidence.

    Science.gov (United States)

    Lavis, John N; Oxman, Andrew D; Moynihan, Ray; Paulsen, Elizabeth J

    2008-12-17

    Organizations have been established in many countries and internationally to support the use of research evidence by producing clinical practice guidelines, undertaking health technology assessments, and/or directly supporting the use of research evidence in developing health policy on an international, national, and state or provincial level. Learning from these organizations can reduce the need to 'reinvent the wheel' and inform decisions about how best to organize support for such organizations, particularly in low- and middle-income countries (LMICs). We undertook a multi-method study in three phases - a survey, interviews, and case descriptions that drew on site visits - and in each of the second and third phases we focused on a purposive sample of those involved in the previous phase. We used the seven main recommendations that emerged from the advice offered in the interviews to organize much of the synthesis of findings across phases and methods. We used a constant comparative method to identify themes from across phases and methods. Seven recommendations emerged for those involved in establishing or leading organizations that support the use of research evidence in developing health policy: 1) collaborate with other organizations; 2) establish strong links with policymakers and involve stakeholders in the work; 3) be independent and manage conflicts of interest among those involved in the work; 4) build capacity among those working in the organization; 5) use good methods and be transparent in the work; 6) start small, have a clear audience and scope, and address important questions; and 7) be attentive to implementation considerations, even if implementation is not a remit. Four recommendations emerged for the World Health Organization (WHO) and other international organizations and networks: 1) support collaborations among organizations; 2) support local adaptation efforts; 3) mobilize support; and 4) create global public goods. This synthesis of

  1. Reliability of change in lumbar MRI findings over time in patients with and without disc prosthesis - comparing two different image evaluation methods

    International Nuclear Information System (INIS)

    Berg, Linda; Espeland, Ansgar; Gjertsen, Oeivind; Hellum, Christian; Neckelmann, Gesche; Johnsen, Lars G.; Eide, Geir E.

    2012-01-01

    To assess the reliability of change in lumbar magnetic resonance imaging (MRI) findings evaluated retrospectively by direct comparison of images and by non-comparison. Pre-treatment and 2-year follow-up MRI was performed in 126 patients randomized to disc prosthesis surgery or non-surgical treatment. Two experienced radiologists independently evaluated progress and regress for Modic changes, disc findings, and facet arthropathy (FA) at L3/L4, L4/L5, and L5/S1, both by non-comparison and by comparison of initial and follow-up images. FA was evaluated at all levels, and other findings at non-operated levels. We calculated prevalence- and bias-adjusted kappa (PABAK) values for interobserver agreement. The impact of an adjacent prosthesis (which causes artefacts) and image evaluation method on PABAK was assessed using generalized estimating equations. Image comparison indicated good interobserver agreement on progress and regress (PABAK 0.63-1.00) for Modic changes, posterior high-intensity zone, disc height, and disc contour at L3-S1 and for nucleus pulposus signal and FA at L3/L4; and moderate interobserver agreement (PABAK 0.46-0.59) on decreasing nucleus signal and increasing FA at L4-S1. Image comparison indicated lower (but fair) interobserver agreement (PABAK 0.29) only for increasing FA at L5/S1 in patients with prosthesis in L4/L5 and/or L5/S1. An adjacent prosthesis had no overall impact on PABAK values (p ≥ 0.22). Comparison yielded higher PABAK values than non-comparison (p < 0.001). Regarding changes in lumbar MRI findings over time, comparison of images can provide moderate or good interobserver agreement, and better agreement than non-comparison. An adjacent prosthesis may not reduce agreement on change for most findings. (orig.)

  2. Estimation Of Young’s Modulus Of Elesticity By The Form Finding Of Grid Shell Structures By The Dynamic Relaxation Method

    Directory of Open Access Journals (Sweden)

    Grančičová Ivana

    2015-12-01

    Full Text Available The paper is basically focused on the process of form finding by the dynamic relaxation method (DRM with the aid of computational tools that enable us to make many calculations with different inputs. There are many important input values with a significant impact on the course of the calculations and the resulting displacement of a structure. One of these values is Young’s modulus of elasticity. This value has a considerable impact on the final displacement of a grid shell structure and the resulting internal forces.

  3. Reliability of an experimental method to analyse the impact point on a golf ball during putting.

    Science.gov (United States)

    Richardson, Ashley K; Mitchell, Andrew C S; Hughes, Gerwyn

    2015-06-01

    This study aimed to examine the reliability of an experimental method identifying the location of the impact point on a golf ball during putting. Forty trials were completed using a mechanical putting robot set to reproduce a putt of 3.2 m, with four different putter-ball combinations. After locating the centre of the dimple pattern (centroid) the following variables were tested; distance of the impact point from the centroid, angle of the impact point from the centroid and distance of the impact point from the centroid derived from the X, Y coordinates. Good to excellent reliability was demonstrated in all impact variables reflected in very strong relative (ICC = 0.98-1.00) and absolute reliability (SEM% = 0.9-4.3%). The highest SEM% observed was 7% for the angle of the impact point from the centroid. In conclusion, the experimental method was shown to be reliable at locating the centroid location of a golf ball, therefore allowing for the identification of the point of impact with the putter head and is suitable for use in subsequent studies.

  4. Cochrane Qualitative and Implementation Methods Group guidance series-paper 3: methods for assessing methodological limitations, data extraction and synthesis, and confidence in synthesized qualitative findings.

    Science.gov (United States)

    Noyes, Jane; Booth, Andrew; Flemming, Kate; Garside, Ruth; Harden, Angela; Lewin, Simon; Pantoja, Tomas; Hannes, Karin; Cargo, Margaret; Thomas, James

    2018-05-01

    The Cochrane Qualitative and Implementation Methods Group develops and publishes guidance on the synthesis of qualitative and mixed-method implementation evidence. Choice of appropriate methodologies, methods, and tools is essential when developing a rigorous protocol and conducting the synthesis. Cochrane authors who conduct qualitative evidence syntheses have thus far used a small number of relatively simple methods to address similarly written questions. Cochrane has invested in methodological work to develop new tools and to encourage the production of exemplar reviews to show the value of more innovative methods that address a wider range of questions. In this paper, in the series, we report updated guidance on the selection of tools to assess methodological limitations in qualitative studies and methods to extract and synthesize qualitative evidence. We recommend application of Grades of Recommendation, Assessment, Development, and Evaluation-Confidence in the Evidence from Qualitative Reviews to assess confidence in qualitative synthesized findings. This guidance aims to support review authors to undertake a qualitative evidence synthesis that is intended to be integrated subsequently with the findings of one or more Cochrane reviews of the effects of similar interventions. The review of intervention effects may be undertaken concurrently with or separate to the qualitative evidence synthesis. We encourage further development through reflection and formal testing. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Finding Sliesthorp?

    DEFF Research Database (Denmark)

    Dobat, Andres S.

    2016-01-01

    In 2003, a hitherto unknown Viking age settlement was discovered at Füsing in Northern Germany close to Hedeby/Schleswig, the largest of the early Scandinavian towns. Finds and building features suggest a high status residence and a seat of some chiefly elite that flourished from around 700 to th...... and the transformation of socio‐political structures in Northern Europe as it transitioned from prehistory into the middle Ages....

  6. A comprehensive method to find RPO trajectory and incentive scheme for promotion of renewable energy in India with study of impact of RPO on tariff

    International Nuclear Information System (INIS)

    Shereef, R.M.; Khaparde, S.A.

    2013-01-01

    Renewable Purchase Obligation (RPO) regime in India started in 2011 with the announcement of benchmark RPO (BRPO) of states for the Financial Year (FY) 2011 by respective State Electricity Regulatory Commissions (SERC), to promote Renewable Energy (RE). The report submitted to Forum of Regulators (FoR) in this regard has recommended uniform rate of increase of BRPO of states and studied the impact of RPO on tariff for FY 2011–2015. However, more rigorous analysis is needed for fixing BRPO in a scientific manner and for fair allocation of incentives to promote RE. This paper attempts to evaluate all states on a common platform to find BRPO, giving due weightage to the state-wise energy demand and RE generation, ensuring minimum change in BRPO of consecutive years and hence less impact of RPO on tariff. To encourage the states to align their actual RPO with BRPO, a financial incentive scheme is proposed giving due weightage to RE consumption, RE capacity addition and RPO compliance of the states. The methods are illustrated for the Indian states using real system data. A study of RPO's impact on electricity tariff of Indian states is also conducted and reported for FY 2011–2015, considering Renewable Energy Certificate (REC). - Author-Highlights: • Proposes a comprehensive method to find the BRPO of Indian states for promoting RE. • Minimum change in BRPO of consecutive years hence less impact of RPO on tariff. • Incentive scheme to encourage the states to align their actual RPO with BRPO. • Study of impact of RPO on tariff of Indian states is conducted

  7. Hide and vanish: data sets where the most parsimonious tree is known but hard to find, and their implications for tree search methods.

    Science.gov (United States)

    Goloboff, Pablo A

    2014-10-01

    Three different types of data sets, for which the uniquely most parsimonious tree can be known exactly but is hard to find with heuristic tree search methods, are studied. Tree searches are complicated more by the shape of the tree landscape (i.e. the distribution of homoplasy on different trees) than by the sheer abundance of homoplasy or character conflict. Data sets of Type 1 are those constructed by Radel et al. (2013). Data sets of Type 2 present a very rugged landscape, with narrow peaks and valleys, but relatively low amounts of homoplasy. For such a tree landscape, subjecting the trees to TBR and saving suboptimal trees produces much better results when the sequence of clipping for the tree branches is randomized instead of fixed. An unexpected finding for data sets of Types 1 and 2 is that starting a search from a random tree instead of a random addition sequence Wagner tree may increase the probability that the search finds the most parsimonious tree; a small artificial example where these probabilities can be calculated exactly is presented. Data sets of Type 3, the most difficult data sets studied here, comprise only congruent characters, and a single island with only one most parsimonious tree. Even if there is a single island, missing entries create a very flat landscape which is difficult to traverse with tree search algorithms because the number of equally parsimonious trees that need to be saved and swapped to effectively move around the plateaus is too large. Minor modifications of the parameters of tree drifting, ratchet, and sectorial searches allow travelling around these plateaus much more efficiently than saving and swapping large numbers of equally parsimonious trees with TBR. For these data sets, two new related criteria for selecting taxon addition sequences in Wagner trees (the "selected" and "informative" addition sequences) produce much better results than the standard random or closest addition sequences. These new methods for Wagner

  8. New treatment method for developmental dysplasia of the hips after walking age. Arthroscopic reduction with limboplasty based on the findings of preoperative imaging

    International Nuclear Information System (INIS)

    Kitano, Toshio; Morita, Mitsuaki; Nakagawa, Keisuke; Wada, Mayuko; Kuroda, Takaaki; Imai, Yuuki; Sakai, Toshiyuki; Eguchi, Yoshitaka

    2010-01-01

    What makes treatment choice for developmental dysplasia of the hips diagnosed after walking age difficult is the poor understanding of prereduction conditions that obstruct the reduction in spatial terms. To evaluate these problems, we employed subtraction three-dimensional imaging to search for the factors involved in intraarticular obstruction. On the basis of the findings of preoperative subtraction three-dimensional imaging from computed tomography, we developed a new method, a minimum invasive arthroscopic reduction with limboplasty, for reduction of developmental dysplasia of the hips after walking age. The purposes of this report were to: describe the technique of the arthroscopic procedure, and evaluate our new method using radiographic parameters. Ten patients with ten hips with developmental dysplasia after walking age treated by arthroscopic reduction with limboplasty were included in this study. The mean age of the patients at reduction was 22.6 months (range, 18.6-29.7 months); mean age at follow up was 7.2 years (range, 3.9-10.9 years); and mean follow up was 5.4 years (range, 1.7-9.0 years). These ten hips were evaluated using radiographic measurements. Moderate or severe avascular necrosis of the femoral head was not observed. Two hips that had a spherical-shaped head with minimal residual height loss or coxa magna were classified as Kalamchi and MacEwen grade 1. Additional surgery had been performed for two hips classified as Severin group 4 during the course of follow up. These two hips were classified as Severin group 1 at final examination. One more hip was classified as Severin group 4 at final examination, and additional surgery was recommended. The remaining seven hips (70%) therefore obtained good evaluations by arthroscopic reduction with limboplasty alone. We developed a new reduction method by using an arthroscopic procedure for the reduction of developmental dysplasia of the hips after walking age when this dysplasia failed to be reduced

  9. Application of advanced biomechanical methods in studying low back pain – recent development in estimation of lower back loads and large-array surface electromyography and findings

    Directory of Open Access Journals (Sweden)

    Bazrgari B

    2017-07-01

    Full Text Available Babak Bazrgari,1 Ting Xia2 1F. Joseph Halcomb III, M.D. Department of Biomedical Engineering, University of Kentucky, Lexington, KY, 2Palmer Center for Chiropractic Research, Palmer College of Chiropractic, Davenport, IA, USA Abstract: Low back pain (LBP is a major public health problem and the leading disabling musculoskeletal disorder globally. A number of biomechanical methods using kinematic, kinetic and/or neuromuscular approaches have been used to study LBP. In this narrative review, we report recent developments in two biomechanical methods: estimation of lower back loads and large-array surface electromyography (LA-SEMG and the findings associated with LBP. The ability to estimate lower back loads is very important for the prevention and the management of work-related low back injuries based on the mechanical loading model as one category of LBP classification. The methods used for estimation of lower back loads vary from simple rigid link-segment models to sophisticated, optimization-based finite element models. In general, reviewed reports of differences in mechanical loads experienced in lower back tissues between patients with LBP and asymptomatic individuals are not consistent. Such lack of consistency is primarily due to differences in activities under which lower back mechanical loads were investigated as well as heterogeneity of patient populations. The ability to examine trunk neuromuscular behavior is particularly relevant to the motor control model, another category of LBP classification. LA-SEMG not only is noninvasive but also provides spatial resolution within and across muscle groups. Studies using LA-SEMG showed that healthy individuals exhibit highly organized, symmetric back muscle activity patterns, suggesting an orderly recruitment of muscle fibers. In contrast, back muscle activity patterns in LBP patients are asymmetric or multifocal, suggesting lack of orderly muscle recruitment. LA-SEMG was also shown capable of

  10. Accuracy of unfolded map method for determining the left ventricular border. Evaluation of the cut-off value from autopsy finding

    International Nuclear Information System (INIS)

    Sugibayashi, Keiichi; Abe, Yoshiteru; Suga, Yutaka

    1996-01-01

    To improve the quantification of the left ventricular surface area (LVSA) by unfolded map method, we evaluated the cut-off value for determining the left ventricular border. The LVSA measured by unfolded map was compared with those measured using myocardial phantom and autopsy findings. The relative error (RE) was calculated as difference between LVSA in phantom and area of unfolded map. In phantom study, the cut-off value was calculated as 73.3±0.5% when the RE was zero. In autopsy study, the cut-off value was 74.0±7.2%. The area of unfolded map had good correlation with LVSA at autopsy when the cut-off value was 74% (r=0.83, p<0.003). The diameter of left ventricle at autopsy was compared with that of beating heart obtained by two-dimensional echocardiography, because the area of unfolded map was greater than LVSA at autopsy. The ratio of LVSA at autopsy to beating heart was calculated as 1.37. The suitable cut-off value was evaluated as 55.6% when the unfolded map area obtained by autopsy was increased 1.37 magnifications. There was a good correlation between LVSA of unfolded map (cut-off=56%) and the LVSA at autopsy (r=0.90, p<0.001). These results suggest that the cut-off value for determining the left ventricular border in vivo is 56%. (author)

  11. Characterization of the porosity of human dental enamel and shear bond strength in vitro after variable etch times: initial findings using the BET method.

    Science.gov (United States)

    Nguyen, Trang T; Miller, Arthur; Orellana, Maria F

    2011-07-01

    (1) To quantitatively characterize human enamel porosity and surface area in vitro before and after etching for variable etching times; and (2) to evaluate shear bond strength after variable etching times. Specifically, our goal was to identify the presence of any correlation between enamel porosity and shear bond strength. Pore surface area, pore volume, and pore size of enamel from extracted human teeth were analyzed by Brunauer-Emmett-Teller (BET) gas adsorption before and after etching for 15, 30, and 60 seconds with 37% phosphoric acid. Orthodontic brackets were bonded with Transbond to the samples with variable etch times and were subsequently applied to a single-plane lap shear testing system. Pore volume and surface area increased after etching for 15 and 30 seconds. At 60 seconds, this increase was less pronounced. On the contrary, pore size appears to decrease after etching. No correlation was found between variable etching times and shear strength. Samples etched for 15, 30, and 60 seconds all demonstrated clinically viable shear strength values. The BET adsorption method could be a valuable tool in enhancing our understanding of enamel characteristics. Our findings indicate that distinct quantitative changes in enamel pore architecture are evident after etching. Further testing with a larger sample size would have to be carried out for more definitive conclusions to be made.

  12. Development and optimization of a mixed beverage made of whey and water-soluble soybean extract flavored with chocolate using a simplex-centroid design

    Directory of Open Access Journals (Sweden)

    Dóris Faria de OLIVEIRA

    2017-10-01

    Full Text Available Abstract This study aimed to combine the nutritional advantages of whey and soybean by developing a type of chocolate beverage with water-soluble soybean extract dissolved in whey. Different concentrations of thickeners (carrageenan, pectin and starch – maximum level of 500 mg.100 mL-1 were tested by a simplex-centroid design. Several physicochemical, rheological, and sensory properties of the beverages were measured and a multi-response optimization was conducted aiming to obtain a whey and soybean beverage with increased overall sensory impression and maximum purchase intention. Beverages presented mean protein levels higher than 3.1 g.100 mL-1, a low content of lipids (< 2 g.100 mL-1 and total soluble solids ≥20 g.100 mL-1. Response surface methodology was applied and the proposed for overall impression and purchase intention presented R2=0.891 and R2=0.966, respectively. The desirability index (d-value=0.92 showed that the best formulation should contain 46% carrageenan and 54% pectin in the formulation. The formulation manufactured with this combination of thickeners was tested and the overall impression was 7.11±1.09 (over a 9-point hedonic scale and the purchase intention was 4.0±1.3 (over a 5-point hedonic scale, thus showing that the proposed models were predictive.

  13. Multiresponse optimisation on biodiesel obtained through a ternary mixture of vegetable oil and animal fat: Simplex-centroid mixture design application

    International Nuclear Information System (INIS)

    Orives, Juliane Resges; Galvan, Diego; Coppo, Rodolfo Lopes; Rodrigues, Cezar Henrique Furtoso; Angilelli, Karina Gomes; Borsato, Dionísio

    2014-01-01

    Highlights: • Mixture experimental design was used which allowed evaluating various responses. • Predictive equation was presented that allows verifying the behavior of the mixtures. • The results depicted that the obtained biodiesel dispensed the use of any additives. - Abstract: The quality of biodiesel is a determining factor in its commercialisation, and parameters such as the Cold Filter Plugging Point (CFPP) and Induction Period (IP) determine its operability in engines on cold days and storage time, respectively. These factors are important in characterisation of the final product. A B100 biodiesel formulation was developed using a multiresponse optimisation, for which the CFPP and cost were minimised, and the IP and yield were maximised. The experiments were carried out according to a simplex-centroid mixture design using soybean oil, beef tallow, and poultry fat. The optimum formulation consisted of 50% soybean oil, 20% beef tallow, and 30% poultry fat and had CFPP values of 1.92 °C, raw material costs of US$ 903.87 ton −1 , an IP of 8.28 h, and a yield of 95.68%. Validation was performed in triplicate and the t-test indicated that there were no difference between the estimated and experimental values for none of the dependent variables, thus indicating efficiency of the joint optimisation in the biodiesel production process that met the criteria for CFPP and IP, as well as high yield and low cost

  14. Combined effect of carnosol, rosmarinic acid and thymol on the oxidative stability of soybean oil using a simplex centroid mixture design.

    Science.gov (United States)

    Saoudi, Salma; Chammem, Nadia; Sifaoui, Ines; Jiménez, Ignacio A; Lorenzo-Morales, Jacob; Piñero, José E; Bouassida-Beji, Maha; Hamdi, Moktar; L Bazzocchi, Isabel

    2017-08-01

    Oxidation taking place during the use of oil leads to the deterioration of both nutritional and sensorial qualities. Natural antioxidants from herbs and plants are rich in phenolic compounds and could therefore be more efficient than synthetic ones in preventing lipid oxidation reactions. This study was aimed at the valorization of Tunisian aromatic plants and their active compounds as new sources of natural antioxidant preventing oil oxidation. Carnosol, rosmarinic acid and thymol were isolated from Rosmarinus officinalis and Thymus capitatus by column chromatography and were analyzed by nuclear magnetic resonance. Their antioxidant activities were measured by DPPH, ABTS and FRAP assays. These active compounds were added to soybean oil in different proportions using a simplex-centroid mixture design. Antioxidant activity and oxidative stability of oils were determined before and after 20 days of accelerated oxidation at 60 °C. Results showed that bioactive compounds are effective in maintaining oxidative stability of soybean oil. However, the binary interaction of rosmarinic acid and thymol caused a reduction in antioxidant activity and oxidative stability of soybean oil. Optimum conditions for maximum antioxidant activity and oxidative stability were found to be an equal ternary mixture of carnosol, rosmarinic acid and thymol. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

  15. Main findings

    International Nuclear Information System (INIS)

    2014-01-01

    Licensing regimes vary from country to country. When the license regime involves several regulators and several licenses, this may lead to complex situations. Identifying a leading organisation in charge of overall coordination including preparation of the licensing decision is a useful practice. Also, if a stepwise licensing process is implemented, it is important to fix in legislation decisions and/or time points and to identify the relevant actors. There is considerable experience in civil and mining engineering that can be applied when constructing a deep geological disposal facility. Specific challenges are, however, the minimization of disturbances to the host rock and the understanding of its long-term behavior. Construction activities may affect the geo-hydraulic and geochemical properties of the various system components which are important safety features of the repository system. Clearly defined technical specifications and an effective quality management plan are important in ensuring successful repository implementation which is consistent with safety requirements. Monitoring plan should also be defined in advance. The regulatory organization should prepare itself to the licensing review before construction by allocating sufficient resources. It should increase its competence, e.g., by interacting early with the implementer and through its own R and D. This will allow the regulator to define appropriate technical conditions associated to the construction license and to elaborate a relevant inspection plan of the construction work. After construction, obtaining the operational license is the most important and crucial step. Main challenges include (a) establishing sufficient confidence so that the methods for closing the individual disposal units comply with the safety objectives and (b) addressing the issue of ageing of materials during a 50-100 years operational period. This latter challenge is amplified when reversibility/retrievability is required

  16. Challenges from Tuberculosis Diagnosis to Care in Community-Based Active Case Finding among the Urban Poor in Cambodia: A Mixed-Methods Study.

    Science.gov (United States)

    Lorent, Natalie; Choun, Kimcheng; Malhotra, Shelly; Koeut, Pichenda; Thai, Sopheak; Khun, Kim Eam; Colebunders, Robert; Lynen, Lut

    2015-01-01

    While community-based active case finding (ACF) for tuberculosis (TB) holds promise for increasing early case detection among hard-to-reach populations, limited data exist on the acceptability of active screening. We aimed to identify barriers and explore facilitators on the pathway from diagnosis to care among TB patients and health providers. Mixed-methods study. We administered a survey questionnaire to, and performed in-depth interviews with, TB patients identified through ACF from poor urban settlements in Phnom Penh, Cambodia. Additionally, we conducted focus group discussions and in-depth interviews with community and public health providers involved in ACF, respectively. Acceptance of home TB screening was strong among key stakeholders due to perceived reductions in access barriers and in direct and indirect patient costs. Privacy and stigma were not an issue. To build trust and facilitate communication, the participation of community representatives alongside health workers was preferred. Most health providers saw ACF as complementary to existing TB services; however, additional workload as a result of ACF was perceived as straining operating capacity at public sector sites. Proximity to a health facility and disease severity were the strongest determinants of prompt care-seeking. The main reasons reported for delays in treatment-seeking were non-acceptance of diagnosis, high indirect costs related to lost income/productivity and transportation expenses, and anticipated side-effects from TB drugs. TB patients and health providers considered home-based ACF complementary to facility-based TB screening. Strong engagement with community representatives was believed critical in gaining access to high risk communities. The main barriers to prompt treatment uptake in ACF were refusal of diagnosis, high indirect costs, and anticipated treatment side-effects. A patient-centred approach and community involvement were essential in mitigating barriers to care in

  17. Why do some physicians in Portuguese-speaking African countries work exclusively for the private sector? Findings from a mixed-methods study.

    Science.gov (United States)

    Russo, Giuliano; de Sousa, Bruno; Sidat, Mohsin; Ferrinho, Paulo; Dussault, Gilles

    2014-09-11

    Despite the growing interest in the private health sector in low- and middle-income countries, little is known about physicians working outside the public sector. The present work adopts a mixed-methods approach to explore characteristics, working patterns, choices, and motivations of the physicians working exclusively for the private sector in the capital cities of Cape Verde, Guinea Bissau, and Mozambique. The paper's objective is to contribute to the understanding of such physicians, ultimately informing the policies regulating the medical profession in low- and middle-income countries. The qualitative part of the study involved 48 interviews with physicians and health policy-makers and aimed at understanding the practice in the three locations. The quantitative study included a survey of 329 physicians, and multivariate analysis was conducted to analyse characteristics, time allocation, earnings, and motivations of those physicians working only for the private sector, in comparison to their public sector-only and dual practice peers. Our findings showed that only a limited proportion of physicians in the three locations work exclusively for the private sector (11.2%), with members of this group being older than those practicing only in the public or in both sectors. They were found to work fewer hours per week (49 hours) than their public (56 hours) and dual practice peers (62 hours) (P private-only physicians' preference for an independent and more flexible work modality, and this was quoted as a determining factor for their choice of sector. This group appears to include those working in the more informal sector, and those who decided to leave the civil service following a disagreement with the public employer. The study shows the importance of understanding the relation between health professionals' characteristics, motivations, and their engagement with the private sector to develop effective policies to regulate the profession. This may ultimately

  18. Challenges from Tuberculosis Diagnosis to Care in Community-Based Active Case Finding among the Urban Poor in Cambodia: A Mixed-Methods Study.

    Directory of Open Access Journals (Sweden)

    Natalie Lorent

    Full Text Available While community-based active case finding (ACF for tuberculosis (TB holds promise for increasing early case detection among hard-to-reach populations, limited data exist on the acceptability of active screening. We aimed to identify barriers and explore facilitators on the pathway from diagnosis to care among TB patients and health providers.Mixed-methods study. We administered a survey questionnaire to, and performed in-depth interviews with, TB patients identified through ACF from poor urban settlements in Phnom Penh, Cambodia. Additionally, we conducted focus group discussions and in-depth interviews with community and public health providers involved in ACF, respectively.Acceptance of home TB screening was strong among key stakeholders due to perceived reductions in access barriers and in direct and indirect patient costs. Privacy and stigma were not an issue. To build trust and facilitate communication, the participation of community representatives alongside health workers was preferred. Most health providers saw ACF as complementary to existing TB services; however, additional workload as a result of ACF was perceived as straining operating capacity at public sector sites. Proximity to a health facility and disease severity were the strongest determinants of prompt care-seeking. The main reasons reported for delays in treatment-seeking were non-acceptance of diagnosis, high indirect costs related to lost income/productivity and transportation expenses, and anticipated side-effects from TB drugs.TB patients and health providers considered home-based ACF complementary to facility-based TB screening. Strong engagement with community representatives was believed critical in gaining access to high risk communities. The main barriers to prompt treatment uptake in ACF were refusal of diagnosis, high indirect costs, and anticipated treatment side-effects. A patient-centred approach and community involvement were essential in mitigating barriers

  19. Two methods to estimate the position resolution for straw chambers with strip readout

    International Nuclear Information System (INIS)

    Golutvin, I.A.; Movchan, S.A.; Peshekhonov, V.D.; Preda, T.

    1992-01-01

    The centroid and charge-ratio methods are presented to estimate the position resolution of the straw chambers with strip readout. For the straw chambers of 10 mm in diameter, the highest position resolution was obtained for a strip pitch of 5 mm. With the centroid method and perpendicular X-ray beam, the position resolution was ≅120 μm, for the signal-to-noise ratio of 60-65. The charge-ratio method has demonstrated ≅10% better position resolution at the edges of the strip. 6 refs.; 5 figs

  20. Assessment of a multimedia-based prospective method to support public deliberations on health technology design: participant survey findings and qualitative insights.

    Science.gov (United States)

    Lehoux, P; Jimenez-Pernett, J; Miller, F A; Williams-Jones, B

    2016-10-26

    Using a combination of videos and online short stories, we conducted four face-to-face deliberative workshops in Montreal (Quebec, Canada) with members of the public who later joined additional participants in an online forum to discuss the social and ethical implications of prospective technologies. This paper presents the participants' appraisal of our intervention and provides novel qualitative insights into the use of videos and online tools in public deliberations. We applied a mixed-method study design. A self-administered survey contained open- and close-ended items using a 5-level Likert-like scale. Absolute frequencies and proportions for the close-ended items were compiled. Qualitative data included field notes, the transcripts of the workshops and the participants' contributions to the online forum. The qualitative data were used to flesh out the survey data describing the participants' appraisal of: 1) the multimedia components of our intervention; 2) its deliberative face-to-face and online processes; and 3) its perceived effects. Thirty-eight participants contributed to the workshops and 57 to the online forum. A total of 46 participants filled-in the survey, for a response rate of 73 % (46/63). The videos helped 96 % of the participants to understand the fictional technologies and the online scenarios helped 98 % to reflect about the issues raised. Up to 81 % considered the arguments of the other participants to be well thought-out. Nearly all participants felt comfortable sharing their ideas in both the face-to-face (89 %) and online environments (93 %), but 88 % preferred the face-to-face workshop. As a result of the intervention, 85 % reflected more about the pros and cons of technology and 94 % learned more about the way technologies may transform society. This study confirms the methodological feasibility of a deliberative intervention whose originality lies in its use of videos and online scenarios. To increase deliberative depth and foster a

  1. Generalized Centroid Estimators in Bioinformatics

    Science.gov (United States)

    Hamada, Michiaki; Kiryu, Hisanori; Iwasaki, Wataru; Asai, Kiyoshi

    2011-01-01

    In a number of estimation problems in bioinformatics, accuracy measures of the target problem are usually given, and it is important to design estimators that are suitable to those accuracy measures. However, there is often a discrepancy between an employed estimator and a given accuracy measure of the problem. In this study, we introduce a general class of efficient estimators for estimation problems on high-dimensional binary spaces, which represent many fundamental problems in bioinformatics. Theoretical analysis reveals that the proposed estimators generally fit with commonly-used accuracy measures (e.g. sensitivity, PPV, MCC and F-score) as well as it can be computed efficiently in many cases, and cover a wide range of problems in bioinformatics from the viewpoint of the principle of maximum expected accuracy (MEA). It is also shown that some important algorithms in bioinformatics can be interpreted in a unified manner. Not only the concept presented in this paper gives a useful framework to design MEA-based estimators but also it is highly extendable and sheds new light on many problems in bioinformatics. PMID:21365017

  2. An alignment-free method to find similarity among protein sequences via the general form of Chou's pseudo amino acid composition.

    Science.gov (United States)

    Gupta, M K; Niyogi, R; Misra, M

    2013-01-01

    In this paper, we propose a method to create the 60-dimensional feature vector for protein sequences via the general form of pseudo amino acid composition. The construction of the feature vector is based on the contents of amino acids, total distance of each amino acid from the first amino acid in the protein sequence and the distribution of 20 amino acids. The obtained cosine distance metric (also called the similarity matrix) is used to construct the phylogenetic tree by the neighbour joining method. In order to show the applicability of our approach, we tested it on three proteins: 1) ND5 protein sequences from nine species, 2) ND6 protein sequences from eight species, and 3) 50 coronavirus spike proteins. The results are in agreement with known history and the output from the multiple sequence alignment program ClustalW, which is widely used. We have also compared our phylogenetic results with six other recently proposed alignment-free methods. These comparisons show that our proposed method gives a more consistent biological relationship than the others. In addition, the time complexity is linear and space required is less as compared with other alignment-free methods that use graphical representation. It should be noted that the multiple sequence alignment method has exponential time complexity.

  3. Cellular Phone Towers, Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected to orthophotography. Probably includes towers other than cell towers (uncertain). Not published., Published in 2003, 1:1200 (1in=100ft) scale, Sedgwick County Government.

    Data.gov (United States)

    NSGIC Local Govt | GIS Inventory — Cellular Phone Towers dataset current as of 2003. Cell towers developed for Appraiser's Department in 2003. Location was based upon parcel centroids, and corrected...

  4. Statistical comparison of leaching behavior of incineration bottom ash using seawater and deionized water: Significant findings based on several leaching methods.

    Science.gov (United States)

    Yin, Ke; Dou, Xiaomin; Ren, Fei; Chan, Wei-Ping; Chang, Victor Wei-Chung

    2018-02-15

    Bottom ashes generated from municipal solid waste incineration have gained increasing popularity as alternative construction materials, however, they contains elevated heavy metals posing a challenge for its free usage. Different leaching methods are developed to quantify leaching potential of incineration bottom ashes meanwhile guide its environmentally friendly application. Yet, there are diverse IBA applications while the in situ environment is always complicated, challenging its legislation. In this study, leaching tests were conveyed using batch and column leaching methods with seawater as opposed to deionized water, to unveil the metal leaching potential of IBA subjected to salty environment, which is commonly encountered when using IBA in land reclamation yet not well understood. Statistical analysis for different leaching methods suggested disparate performance between seawater and deionized water primarily ascribed to ionic strength. Impacts of leachant are metal-specific dependent on leaching methods and have a function of intrinsic characteristics of incineration bottom ashes. Leaching performances were further compared on additional perspectives, e.g. leaching approach and liquid to solid ratio, indicating sophisticated leaching potentials dominated by combined geochemistry. It is necessary to develop application-oriented leaching methods with corresponding leaching criteria to preclude discriminations between different applications, e.g., terrestrial applications vs. land reclamation. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Vape Factor Fast Find-Adult (VF3-A): a prototype survey method for recording brand-specific vaping factors in adult populations.

    Science.gov (United States)

    Ross, Craig S; Zhang, Tancy C; DeJong, William; Siegel, Michael

    2018-03-23

    In population studies, vaping is often treated as a dichotomous exposure (present/absent) without consideration of specific vaping devices and materials being used. A survey instrument is needed to record specific vaping devices and materials. We developed a database of 613 vaping device models and 3196 vaping liquid products, indexed by device brand, device type, liquid brand, liquid name and liquid flavour type. We developed a survey instrument to allow participants to report their vaping device and liquid from the indexed lists. The survey was pilot tested with a convenience sample of 208 adults (≥age 21). We validated the vaping device and liquid responses with a recontact survey. We report the proportion of respondents finding their products, characteristics of people finding their products and survey response times. Devices used most frequently in the past 30 days were electronic cigarettes (33% of respondents), vaping pens (28%) and vaping mods (16%). Fifty-seven per cent used liquids containing nicotine most frequently in the past 30 days, followed by liquids without nicotine (20%) and marijuana or hashish (10%). Most (85%) participants found their vaping device successfully (median 19.7 s) and 74% found their vaping liquid (median 19.8 s). Females and older adults were less likely to find their devices and liquids. Responses were validated for 91% and 76% of devices and e-liquids, respectively. This study demonstrated the feasibility of an internet-based survey instrument to record specific vaping factors for use in studies of vaping and health. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  6. A new generalized expansion method and its application in finding explicit exact solutions for a generalized variable coefficients KdV equation

    International Nuclear Information System (INIS)

    Sabry, R.; Zahran, M.A.; Fan Engui

    2004-01-01

    A generalized expansion method is proposed to uniformly construct a series of exact solutions for general variable coefficients non-linear evolution equations. The new approach admits the following types of solutions (a) polynomial solutions, (b) exponential solutions, (c) rational solutions, (d) triangular periodic wave solutions, (e) hyperbolic and solitary wave solutions and (f) Jacobi and Weierstrass doubly periodic wave solutions. The efficiency of the method has been demonstrated by applying it to a generalized variable coefficients KdV equation. Then, new and rich variety of exact explicit solutions have been found

  7. Psychological Distress and Help Seeking Amongst Higher Education Students: Findings from a Mixed Method Study of Undergraduate Nursing/Midwifery and Teacher Education Students in Ireland

    Science.gov (United States)

    Deasy, Christine; Coughlan, Barry; Pironom, Julie; Jourdan, Didier; Mannix-McNamara, Patricia

    2016-01-01

    Psychological distress as experienced by higher education students is of major concern because of its potential to adversely impact academic performance, retention, mental health and lifestyle. This paper reports a mixed method investigation of student self-reported psychological distress and help-seeking behaviour. The sample comprised all…

  8. Striking trends in the incidence of health problems in the Netherlands (2002-05): findings from a new method for record linkage in general practice.

    NARCIS (Netherlands)

    Biermans, M.C.J.; Spreeuwenberg, P.; Verheij, R.A.; Bakker, D.H. de; Vries Robbé, P.F. de; Zielhuis, G.A.

    2009-01-01

    BACKGROUND: This study aimed to detect striking trends based on a new strategy for monitoring public health. METHODS: We used data over 4 years from electronic medical records of a large, nationally representative network of general practices. Episodes were either directly recorded by general

  9. How to find non-dependent opiate users: a comparison of sampling methods in a field study of opium and heroin users

    NARCIS (Netherlands)

    Korf, D.J.; van Ginkel, P.; Benschop, A.

    2010-01-01

    Background/aim The first aim is to better understand the potentials and limitations of different sampling methods for reaching a specific, rarely studied population of drug users and for persuading them to take part in a multidisciplinary study. The second is to determine the extent to which these

  10. Are current case-finding methods under-diagnosing tuberculosis among women in Myanmar? An analysis of operational data from Yangon and the nationwide prevalence survey.

    Science.gov (United States)

    Khan, M S; Khine, T M; Hutchison, C; Coker, R J; Hane, K M; Innes, A L; Aung, S

    2016-03-03

    Although there is a large increase in investment for tuberculosis control in Myanmar, there are few operational analyses to inform policies. Only 34% of nationally reported cases are from women. In this study, we investigate sex differences in tuberculosis diagnoses in Myanmar in order to identify potential health systems barriers that may be driving lower tuberculosis case finding among women. From October 2014 to March 2015, we systematically collected data on all new adult smear positive tuberculosis cases in ten township health centres across Yangon, the largest city in Myanmar, to produce an electronic tuberculosis database. We conducted a descriptive cross-sectional analysis of sex differences in tuberculosis diagnoses at the township health centres. We also analysed national prevalence survey data to calculate additional case finding in men and women by using sputum culture when smear microscopy was negative, and estimated the sex-specific impact of using a more sensitive diagnostic tool at township health centres. Overall, only 514 (30%) out of 1371 new smear positive tuberculosis patients diagnosed at the township health centres were female. The proportion of female patients varied by township (from 21% to 37%, p = 0.0172), month of diagnosis (37% in February 2015 and 23% in March 2015 p = 0.0004) and age group (26% in 25-64 years and 49% in 18-25 years, p Myanmar, found that substantially fewer women than men were diagnosed in all study townships. The sex ratio of newly diagnosed cases varied by age group, month of diagnosis and township of diagnosis. Low sensitivity of tuberculosis diagnosis may lead to a potential under-diagnosis of tuberculosis among women.

  11. Online Versus Telephone Methods to Recruit and Interview Older Gay and Bisexual Men Treated for Prostate Cancer: Findings from the Restore Study.

    Science.gov (United States)

    Rosser, B R Simon; Capistrant, Benjamin

    2016-07-19

    Recently, researchers have faced the challenge of conflicting recommendations for online versus traditional methods to recruit and interview older, sexual minority men. Older populations represent the cohort least likely to be online, necessitating the use of traditional research methods, such as telephone or in-person interviews. By contrast, gay and bisexual men represent a population of early adopters of new technology, both in general and for medical research. In a study of older gay and bisexual men with prostate cancer, we asked whether respondents preferred online versus offline methods for data collection. Given the paucity of research on how to recruit older gay and bisexual men in general, and older gay and bisexual men with prostate cancer in particular, we conducted an observational study to identify participant preferences when participating in research studies. To test online versus offline recruitment demographic data collection, and interview preferences of older gay and bisexual men with prostate cancer. Email blasts were sent from a website providing support services for gay and bisexual men with prostate cancer, supplemented with an email invitation from the web-host. All invitations provided information via the study website address and a toll-free telephone number. Study tasks included respondents being screened, giving informed consent, completing a short survey collecting demographic data, and a 60-75 minute telephone or Internet chat interview. All materials stressed that enrollees could participate in each task using either online methods or by telephone, whichever they preferred. A total of 74 men were screened into the study, and 30 were interviewed. The average age of the participants was 63 years (standard deviation 6.9, range 48-75 years), with most residing in 14 American states, and one temporarily located overseas. For screening, consent, and the collection of demographic data, 97% (29/30) of the participants completed these tasks

  12. A New Method Based on Simulation-Optimization Approach to Find Optimal Solution in Dynamic Job-shop Scheduling Problem with Breakdown and Rework

    Directory of Open Access Journals (Sweden)

    Farzad Amirkhani

    2017-03-01

    The proposed method is implemented on classical job-shop problems with objective of makespan and results are compared with mixed integer programming model. Moreover, the appropriate dispatching priorities are achieved for dynamic job-shop problem minimizing a multi-objective criteria. The results show that simulation-based optimization are highly capable to capture the main characteristics of the shop and produce optimal/near-optimal solutions with highly credibility degree.

  13. How to find non-dependent opiate users: a comparison of sampling methods in a field study of opium and heroin users.

    Science.gov (United States)

    Korf, Dirk J; van Ginkel, Patrick; Benschop, Annemieke

    2010-05-01

    The first aim is to better understand the potentials and limitations of different sampling methods for reaching a specific, rarely studied population of drug users and for persuading them to take part in a multidisciplinary study. The second is to determine the extent to which these different methods reach similar or dissimilar segments of the non-dependent opiate-using population. Using ethnographic fieldwork (EFW) and targeted canvassing (TARC; small newspaper advertisements and website announcements), supplemented by snowball referrals, we recruited and interviewed 127 non-dependent opiate users (lifetime prevalence of use 5-100 times; 86.6% had used heroin and 56.7% opium). Average age was 39.0; 66.1% were male and 33.9% female. In addition to opiates, many respondents had wide experience with other illicit drugs. The majority had non-conventional lifestyles. Both EFW and TARC yielded only limited numbers of snowball referrals. EFW requires specific skills, is labour-intensive, thus expensive, but allows unsuitable candidates to be excluded faster. Respondents recruited through EFW were significantly more likely to have experience with opium and various drugs other than opiates. TARC resulted in larger percentages of women and respondents with conventional lifestyles. TARC is less labour-intensive but requires more time for screening candidates; its cost-effectiveness depends on the price of advertising for the recruitment. Different methods reach different segments of the population of non-dependent opiate users. It is useful to employ a multi-method approach to reduce selectivity. Copyright 2009 Elsevier B.V. All rights reserved.

  14. Finding of experience of the use of computer-integrated forms and methods of teaching in the process of preparation of future teachers of initial school

    Directory of Open Access Journals (Sweden)

    Sinopalnikova N.N.

    2010-06-01

    Full Text Available Theoretically grounded and experimentally examined that one of the trends of future teachers training for the integrated activity is gaining experience in using the integrated organization forms of learning. It is realized in the process of specially organized student's learning and during their pedagogical practice. It was promoted by conducting the special course The integrated forms of learning organization in primary school with the use of interactive forms and methods of learning, fulfilling the aimed tasks while passing pedagogical practice.

  15. Importance of diagnostic laboratory methods of beta hemolytic streptococcus group A in comparison with clinical findings in the diagnosis of streptococcal sore throat and unnecessary antibacterial therapy

    Directory of Open Access Journals (Sweden)

    Peiman Eini

    2012-04-01

    Full Text Available Background: Streptococcus Pyogenes (group A streptococcus, GAS is the most important cause of bacterial pharyngitis in children and adolescents. Acute pharyngitis is one of the most common conditions in all ages but it is most common in children. Over diagnosis of acute pharyngitis represents one of the major causes of antibiotic abuse. The goal of this study is to make an estimate of the frequency of group A streptococcus in sore throat patients in Farshchian hospital emergency department and clinic in Hamadan. Methods: For estimation of the clinical features role in diagnosis of streptococcal sore throat, we took samples of 100 patients with average age of 32.96±29.86 years with sore throat. We took samples from pharynx and used standard methods of bacteriology in order to detect streptococcus. Results: Group A Streptococcus (GAS accounts for 3 percent of all cases of pharyngitis. Clinically, all of the patients had sore throat. The percent breakdowns are as follows: 30% had exudate, 78% had fever, 8% had lymphadenopathy and 7.7 percent of exudative pharyngitis was streptococcal. The cost for unnecessary antibiotic therapy for every single patient who had negative pharynx culture was approximately 32160 Rails. Conclusion: The low frequency of streptococcus pharyngitis in treated patients reveal that diagnosis based on clinical features is not reliable. We recommend use of other diagnostic methods such as Rapid Antigen Detection Tests (RATs. Only reliable and scientific protocols for antibiotic to therapy.

  16. Methods for medical device and equipment procurement and prioritization within low- and middle-income countries: findings of a systematic literature review.

    Science.gov (United States)

    Diaconu, Karin; Chen, Yen-Fu; Cummins, Carole; Jimenez Moyao, Gabriela; Manaseki-Holland, Semira; Lilford, Richard

    2017-08-18

    Forty to 70 % of medical devices and equipment in low- and middle-income countries are broken, unused or unfit for purpose; this impairs service delivery to patients and results in lost resources. Undiscerning procurement processes are at the heart of this issue. We conducted a systematic review of the literature to August 2013 with no time or language restrictions to identify what product selection or prioritization methods are recommended or used for medical device and equipment procurement planning within low- and middle-income countries. We explore the factors/evidence-base proposed for consideration within such methods and identify prioritization criteria. We included 217 documents (corresponding to 250 texts) in the narrative synthesis. Of these 111 featured in the meta-summary. We identify experience and needs-based methods used to reach procurement decisions. Equipment costs (including maintenance) and health needs are the dominant issues considered. Extracted data suggest that procurement officials should prioritize devices with low- and middle-income country appropriate technical specifications - i.e. devices and equipment that can be used given available human resources, infrastructure and maintenance capacity. Suboptimal device use is directly linked to incomplete costing and inadequate consideration of maintenance services and user training during procurement planning. Accurate estimation of life-cycle costing and careful consideration of device servicing are of crucial importance.

  17. MANAGEMENT CONTROL SYSTEM AND THE CASE OF CSR IN THE TUNISIAN INDUSTRIAL COMPANIES: WHAT FINDINGS BY THE METHOD OF STRUCTURAL EQUATION?

    Directory of Open Access Journals (Sweden)

    Hichem Dkhili

    2013-01-01

    Full Text Available This study aims to the behavior of management control; it is providing a model to the behavior of integration of social responsibility in the management control tools. This model was validated with 306 Tunisian companies in the industrial sector. Through a questionnaire, the data collected are processed using exploratory and confirmatory analysis by the methods of structural equations. The results revealed that the management control system in industrial Tunisia is facing economic responsibility. This is in response to emerging pressures of uncertainty related to the environment, and in enrolling a strategy of domination by cost. In addition, the management control system is designed as a guidance tool actions and behaviors.

  18. Matrix Organization and Merit Factor Evaluation as a Method to Address the Challenge of Finding a Polymer Material for Roll Coated Polymer Solar Cells

    DEFF Research Database (Denmark)

    Bundgaard, Eva; Livi, Francesco; Hagemann, Ole

    2015-01-01

    The results presented demonstrate how the screening of 104 light-absorbing low band gap polymers for suitability in roll coated polymer solar cells can be accomplished through rational synthesis according to a matrix where 8 donor and 13 acceptor units are organized in rows and columns. Synthesis...... silver comb back electrode structure. The matrix organization enables fast identification of active layer materials according to a weighted merit factor that includes more than simply the power conversion efficiency and is used as a method to identify the lead candidates. Based on several characteristics...

  19. A NEW APPLICATION OF THE ASTROMETRIC METHOD TO BREAK SEVERE DEGENERACIES IN BINARY MICROLENSING EVENTS

    International Nuclear Information System (INIS)

    Chung, Sun-Ju; Park, Byeong-Gon; Humphrey, Andrew; Ryu, Yoon-Hyun

    2009-01-01

    When a source star is microlensed by one stellar component of widely separated binary stellar components, after finishing the lensing event, the event induced by the other binary star can be additionally detected. In this paper, we investigate whether the close/wide degeneracies in binary lensing events can be resolved by detecting the additional centroid shift of the source images induced by the secondary binary star in wide binary lensing events. From this investigation, we find that if the source star passes close to the Einstein ring of the secondary companion, the degeneracy can be easily resolved by using future astrometric follow-up observations with high astrometric precision. We determine the probability of detecting the additional centroid shift in binary lensing events with high magnification. From this, we find that the degeneracy of binary lensing events with a separation of ∼<20.0 AU can be resolved with a significant efficiency. We also estimate the waiting time for the detection of the additional centroid shift in wide binary lensing events. We find that for typical Galactic lensing events with a separation of ∼<20.0 AU, the additional centroid shift can be detected within 100 days, and thus the degeneracy of those events can be sufficiently broken within a year.

  20. Servicemembers and veterans with major traumatic limb loss from Vietnam war and OIF/OEF conflicts: survey methods, participants, and summary findings.

    Science.gov (United States)

    Reiber, Gayle E; McFarland, Lynne V; Hubbard, Sharon; Maynard, Charles; Blough, David K; Gambel, Jeffrey M; Smith, Douglas G

    2010-01-01

    Care of veterans and servicemembers with major traumatic limb loss from combat theaters is one of the highest priorities of the Department of Veteran Affairs. We achieved a 62% response rate in our Survey for Prosthetic Use from 298 Vietnam war veterans and 283 servicemembers/veterans from Operation Iraqi Freedom/Operation Enduring Freedom (OIF/OEF) who sustained major traumatic limb loss. Participants reported their combat injuries; health status; quality of life; and prosthetic device use, function, rejection, and satisfaction. Despite the serious injuries experienced, health status was rated excellent, very good, or good by 70.7% of Vietnam war and 85.5% of OIF/OEF survey participants. However, many health issues persist for Vietnam war and OIF/OEF survey participants (respectively): phantom limb pain (72.2%/76.0%), chronic back pain (36.2%/42.1%), residual-limb pain (48.3%/62.9%), prosthesis-related skin problems (51.0%/58.0%), hearing loss (47.0%/47.0%), traumatic brain injury (3.4%/33.9%), depression (24.5%/24.0%), and posttraumatic stress disorder (37.6%/58.7%). Prosthetic devices are currently used by 78.2% of Vietnam war and 90.5% of OIF/OEF survey participants to improve function and mobility. On average, the annual rate for prosthetic device receipt is 10.7-fold higher for OIF/OEF than for Vietnam war survey participants. Findings from this cross-conflict survey identify many strengths in prosthetic rehabilitation for those with limb loss and several areas for future attention.

  1. Radiological findings after gastrectomy

    Energy Technology Data Exchange (ETDEWEB)

    Riedl, P.; Polterauer, P.; Funovics, J.

    1980-06-01

    In 63 patients after total gastrectomy and reconstruction of the small bowel described by Beal-Longmire, Roux and Tomoda radiological findings were correlated with clinical symptoms. No correlation could be found between clinical symptoms of dumping and oesophagitis caused by reflux on one side and increased length of intestinal transit time, increased diameter of intestinal loops and gastro-oesophageal reflux on the other side. Enlarged blind loops after termino-lateral oesophago-jejunostomy and insufficient ligations (operation technique by Tomoda) were correlated with higher incidence of pains. Patients operated by the method of Beal-Longmire and Roux showed better results than those operated with the method of Tomoda.

  2. The TIMSS Videotape Classroom Study: Methods and Findings from an Exploratory Research Project on Eighth-Grade Mathematics Instruction in Germany, Japan, and the United States. A Research and Development Report.

    Science.gov (United States)

    Stigler, James W.; Gonzales, Patrick; Kwanaka, Takako; Knoll, Steffen; Serrano, Ana

    This report presents the methods and preliminary findings of the Videotape Classroom Study, a video study of eighth-grade mathematics lessons in Germany, Japan, and the United States. This exploratory research project is part of the Third International Mathematics and Science Study (TIMSS). The study included 231 eighth-grade mathematics…

  3. Support for targeted sampling of red fox (Vulpes vulpes) feces in Sweden: a method to improve the probability of finding Echinococcus multilocularis.

    Science.gov (United States)

    Miller, Andrea L; Olsson, Gert E; Sollenberg, Sofia; Skarin, Moa; Wahlström, Helene; Höglund, Johan

    2016-11-29

    Localized concentrations of Echinococcus multilocularis eggs from feces of infected red fox (Vulpes vulpes) can create areas of higher transmission risk for rodent hosts and possibly also for humans; therefore, identification of these areas is important. However, in a low prevalence environment, such as Sweden, these areas could be easily overlooked. As part of a project investigating the role of different rodents in the epidemiology of E. multilocularis in Sweden, fox feces were collected seasonally from rodent trapping sites in two regions with known parasite status and in two regions with unknown parasite status, 2013-2015. The aim was to evaluate background contamination in rodent trapping sites from parasite eggs in these regions. To maximize the likelihood of finding fox feces positive for the parasite, fecal collection was focused in habitats with the assumed presence of suitable rodent intermediate hosts (i.e. targeted sampling). Parasite eggs were isolated from feces through sieving-flotation, and parasite species were then confirmed using PCR and sequencing. Most samples were collected in the late winter/early spring and in open fields where both Arvicola amphibius and Microtus agrestis were captured. Fox feces positive for E. multilocularis (41/714) were found within 1-3 field collection sites within each of the four regions. The overall proportion of positive samples was low (≤5.4%) in three regions, but was significantly higher in one region (22.5%, P < 0.001). There was not a significant difference between seasons or years. Compared to previous national screenings, our sampling strategy identified multiple E. multilocularis positive feces in all four regions, including the two regions with previously unknown parasite status. These results further suggest that the distribution of E. multilocularis is highly aggregated in the environment and provide support for further development of a targeted sampling strategy. Our results show that it was

  4. How possible is the development of an operational psychometric method to assess the presence of the 5-HTTLPR s allele? Equivocal preliminary findings

    Directory of Open Access Journals (Sweden)

    Laszik Andras

    2010-05-01

    Full Text Available Abstract Objective The s allele of the 5-hydroxytryptamine transporter-linked promoter region (5-HTTLPR polymorphism of the serotonin transporter gene has been found to be associated with neuroticism-related traits, affective temperaments and response to selective serotonin reuptake inhibitor (SSRI treatment. The aim of the current study was to develop a psychometric tool that could at least partially substitute for laboratory testing and could predict the presence of the s allele. Methods The study included 138 women of Caucasian origin, mean 32.20 ± 1.02 years old. All subjects completed the Hungarian standardised version of the Temperament Evaluation of the Memphis, Pisa, Paris, and San Diego Autoquestionnaire (TEMPS-A instrument and were genotyped for 5-HTTLPR using PCR. The statistical analysis included the calculation of the Index of Discrimination (D, Discriminant Function Analysis, creation of scales on the basis of the above and then item analysis and calculation of sensitivity and specificity. Results Four indices were eventually developed, but their psychometric properties were relatively poor and their joint application did not improve the outcome. Conclusions We could not create a scale that predicts the 5-HTTLPR genotype with sufficient sensitivity and specificity, therefore we could not substitute a psychometric scale for laboratory genetic testing in predicting genotype, and also possibly affective disorder characterisation and treatment.

  5. A novel method of spectrum stabilization

    International Nuclear Information System (INIS)

    Sidhu, N.P.S.

    1978-01-01

    A new type of spectrum stabilizer for a scintillation spectrometer is described. A pulse light source DM 160 is used to introduce an artificial peak in the spectrum at a convenient energy. The centroid of pulse spectrum corresponding to artificial peak is compared with that of suitable reference pulses obtained from the DM 160 driver circuit. Any drift in artificial peak produces a d.c. voltage at the output of centroid comparator and this voltage is used to control the gain of variable gain amplifier to counter the drift. With suitable adjustment the effect of any variation in pulse height of DM 160 driving pulse can be compensated so that the spectrometer gain is independent of any variation, drift etc. in the height of pulse driving DM 160 tube. This circuit is simple and gives improved performance compared to 2 channel method of obtaining the control voltage for variable gain amplifier. (author)

  6. Motivation or demotivation of health workers providing maternal health services in rural areas in Vietnam: findings from a mixed-methods study.

    Science.gov (United States)

    Thu, Nguyen Thi Hoai; Wilson, Andrew; McDonald, Fiona

    2015-12-02

    Motivation is an important driver for health professionals to maintain their professional competencies, continue in the workforce and make a positive contribution to their workplace. While there is some research about the motivation of health workers in low- to middle-income countries, maternal morbidity and mortality remains high and this can be lowered by improving the quality of maternal health services and the training and maintenance of the skills of maternal health workers. This study examines the impact of motivation on maintenance of professional competence among maternal health workers in Vietnam using mixed methods. The study consisted of a survey using a self-administered questionnaire of 240 health workers in five districts across two Vietnamese provinces and in-depth interviews with 43 health workers and health managers at the commune, district and provincial level to explore external factors that influenced motivation. The questionnaire includes a 23-item motivation instrument based on the Kenyan health context, modified for Vietnamese language and culture. The 240 responses represented an estimated 95% of the target sample. Multivariate analysis showed that three factors contributed to the motivation of health workers: access to training (β = -0.14, P = 0.03), ability to perform key tasks (β = 0.22, P = 0.001) and shift schedule (β = -0.13, P = 0.05). Motivation was higher in health workers self-identifying as competent or who were enabled to provide more maternal care services. Motivation was lower in those who worked more frequent night shifts and those who had received training in the last 12 months. The interviews identified that the latter was because they felt the training was irrelevant to them, and in some cases, they do not have the opportunity to practice their learnt skills. The qualitative data also showed other factors relating to service context and organisational management practices contributed to

  7. A comparison of methods for calculating population exposure estimates of daily weather for health research

    Directory of Open Access Journals (Sweden)

    Dear Keith BG

    2006-09-01

    appropriate method conceptually is the use of weather data from sites within 50 kilometres radius of the area weighted to population centres, but a simpler acceptable option is to weight to the geographic centroid.

  8. Granulomatous mastitis: radiological findings

    International Nuclear Information System (INIS)

    Ozturk, M.; Mavili, E.; Kahriman, G.; Akcan, A.C.; Ozturk, F.

    2007-01-01

    Purpose: To evaluate the radiological, ultrasonographic, and magnetic resonance imaging (MRI) findings of idiopathic granulomatous mastitis. Material and Methods: Between April 2002 and June 2005, the mammography, ultrasound, color Doppler ultrasound, non enhanced MR, and dynamic MR findings of nine patients with the preliminary clinical diagnosis of malignancy and the final diagnosis of granulomatous mastitis were evaluated. Results: On mammography, asymmetrical focal densities with no distinct margins, ill-defined masses with spiculated contours, and bilateral multiple ill-defined nodules were seen. On ultrasound, in four patients a discrete, heterogenous hypoechoic mass, in two patients multiple abscesses, in one patient bilateral multiple central hypo peripheral hyperechoic lesions, in two patients heterogeneous hypo- and hyperechoic areas together with parenchymal distortion, and in one patient irregular hypoechoic masses with tubular extensions and abscess cavities were seen. Five of the lesions were vascular on color Doppler ultrasound. On MR mammography, the most frequent finding was focal or diffuse asymmetrical signal intensity changes that were hypointense on T1W images and hyperintense on T2W images, without significant mass effect. Nodular lesions were also seen. On dynamic contrast-enhanced mammography, mass-like enhancement, ring-like enhancement, and nodular enhancement were seen. The time-intensity curves differed from patient to patient and from lesion to lesion. Conclusion: The imaging findings of idiopathic granulomatous mastitis have a wide spectrum, and they are inconclusive for differentiating malignant and benign lesions

  9. Granulomatous mastitis: radiological findings

    Energy Technology Data Exchange (ETDEWEB)

    Ozturk, M.; Mavili, E.; Kahriman, G.; Akcan, A.C.; Ozturk, F. [Depts. of Radiology, Surgery, and Pathology, Erciyes Univ. Medical Faculty, Kayseri (Turkey)

    2007-02-15

    Purpose: To evaluate the radiological, ultrasonographic, and magnetic resonance imaging (MRI) findings of idiopathic granulomatous mastitis. Material and Methods: Between April 2002 and June 2005, the mammography, ultrasound, color Doppler ultrasound, non enhanced MR, and dynamic MR findings of nine patients with the preliminary clinical diagnosis of malignancy and the final diagnosis of granulomatous mastitis were evaluated. Results: On mammography, asymmetrical focal densities with no distinct margins, ill-defined masses with spiculated contours, and bilateral multiple ill-defined nodules were seen. On ultrasound, in four patients a discrete, heterogenous hypoechoic mass, in two patients multiple abscesses, in one patient bilateral multiple central hypo peripheral hyperechoic lesions, in two patients heterogeneous hypo- and hyperechoic areas together with parenchymal distortion, and in one patient irregular hypoechoic masses with tubular extensions and abscess cavities were seen. Five of the lesions were vascular on color Doppler ultrasound. On MR mammography, the most frequent finding was focal or diffuse asymmetrical signal intensity changes that were hypointense on T1W images and hyperintense on T2W images, without significant mass effect. Nodular lesions were also seen. On dynamic contrast-enhanced mammography, mass-like enhancement, ring-like enhancement, and nodular enhancement were seen. The time-intensity curves differed from patient to patient and from lesion to lesion. Conclusion: The imaging findings of idiopathic granulomatous mastitis have a wide spectrum, and they are inconclusive for differentiating malignant and benign lesions.

  10. Method

    Directory of Open Access Journals (Sweden)

    Ling Fiona W.M.

    2017-01-01

    Full Text Available Rapid prototyping of microchannel gain lots of attention from researchers along with the rapid development of microfluidic technology. The conventional methods carried few disadvantages such as high cost, time consuming, required high operating pressure and temperature and involve expertise in operating the equipment. In this work, new method adapting xurography method is introduced to replace the conventional method of fabrication of microchannels. The novelty in this study is replacing the adhesion film with clear plastic film which was used to cut the design of the microchannel as the material is more suitable for fabricating more complex microchannel design. The microchannel was then mold using polymethyldisiloxane (PDMS and bonded with a clean glass to produce a close microchannel. The microchannel produced had a clean edge indicating good master mold was produced using the cutting plotter and the bonding between the PDMS and glass was good where no leakage was observed. The materials used in this method is cheap and the total time consumed is less than 5 hours where this method is suitable for rapid prototyping of microchannel.

  11. Computing travel time when the exact address is unknown: a comparison of point and polygon ZIP code approximation methods.

    Science.gov (United States)

    Berke, Ethan M; Shi, Xun

    2009-04-29

    Travel time is an important metric of geographic access to health care. We compared strategies of estimating travel times when only subject ZIP code data were available. Using simulated data from New Hampshire and Arizona, we estimated travel times to nearest cancer centers by using: 1) geometric centroid of ZIP code polygons as origins, 2) population centroids as origin, 3) service area rings around each cancer center, assigning subjects to rings by assuming they are evenly distributed within their ZIP code, 4) service area rings around each center, assuming the subjects follow the population distribution within the ZIP code. We used travel times based on street addresses as true values to validate estimates. Population-based methods have smaller errors than geometry-based methods. Within categories (geometry or population), centroid and service area methods have similar errors. Errors are smaller in urban areas than in rural areas. Population-based methods are superior to the geometry-based methods, with the population centroid method appearing to be the best choice for estimating travel time. Estimates in rural areas are less reliable.

  12. method

    Directory of Open Access Journals (Sweden)

    L. M. Kimball

    2002-01-01

    Full Text Available This paper presents an interior point algorithm to solve the multiperiod hydrothermal economic dispatch (HTED. The multiperiod HTED is a large scale nonlinear programming problem. Various optimization methods have been applied to the multiperiod HTED, but most neglect important network characteristics or require decomposition into thermal and hydro subproblems. The algorithm described here exploits the special bordered block diagonal structure and sparsity of the Newton system for the first order necessary conditions to result in a fast efficient algorithm that can account for all network aspects. Applying this new algorithm challenges a conventional method for the use of available hydro resources known as the peak shaving heuristic.

  13. Find a Podiatrist

    Science.gov (United States)

    ... RSS Home » Learn About Feet » Find a Podiatrist Find a Podiatrist Search Criteria: First Name: Last Name: ... first 3 digits of your zip code to find the closest doctor. Country: Australia Canada Guam Israel ...

  14. Find a Therapist

    Science.gov (United States)

    ... My ADAA Blog Home / Find Help Print | Email Find a Therapist Zip Code: Radius: 5 Miles 10 ... personal referrals. We supply information to help you find local mental health services and resources that allow ...

  15. Radiological findings in angiofibroma

    Energy Technology Data Exchange (ETDEWEB)

    Schick, B. [Univ. of Marburg (Germany). Dept. of Ear, Nose and Throat Diseases; Kahle, G. [Univ. of Marburg, (Germany). Inst.of Radiology

    2000-11-01

    Surgery after pre-operative embolization has become the main treatment modality in angiofibroma therapy. As surgical planning is based on precise pre-operative tumour evaluation, knowledge of the characteristic growth patterns is of great interest. Analysis of tumour extension and blood supply, as well as methods of controlling intra-operative bleeding, help in determining the appropriate surgical approach. Though benign, angiofibroma demonstrates a locally aggressive nature. This fibrovascular tumour is characterised by typical radiological findings and by predictable growth patterns. The tumour extension and blood supply can be accurately determined by CT, MR imaging and angiography. With classic radiological findings, no pre-operative biopsy is necessary in most angiofibromas. Advances in radiological imaging have contributed to improved surgical planning and tumour resection. The surgeon is able to select the least traumatic approach with secure haemostatic control, which is also critical for avoiding the disturbance of facial skeletal growth in this group of young patients. Embolization, pre-operative autologous donation and the cell saver system for immediate retransfusion of the collected blood after filtration, are important tools for dealing with blood loss in angiofibroma surgery as they minimize homologous blood transfusion.

  16. Abdominal aspergillosis: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Yeom, Suk Keu, E-mail: pagoda20@hanmail.net [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Hye Jin, E-mail: kimhyejin@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Byun, Jae Ho, E-mail: jhbyun@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Kim, Ah Young, E-mail: aykim@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Lee, Moon-Gyu, E-mail: mglee@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of); Ha, Hyun Kwon, E-mail: hkha@amc.seoul.kr [Department of Radiology and Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, 388-1, Poongnap2-dong, Songpa-gu, Seoul, 138-736 (Korea, Republic of)

    2011-03-15

    Objective: In order to retrospectively evaluate the CT findings of abdominal aspergillosis in immunocompromised patients. Materials and methods: CT scans were reviewed with regard to the sites, number, morphologic appearance, attenuation, and the contrast enhancement patterns of the lesions in six patients (5 women, 1 man; mean age, 43.4 years; range, 23-59 years) with pathologically proved abdominal aspergillosis by two gastrointestinal radiologists in consensus. Medical records were also reviewed to determine each patient's clinical status and outcome. Results: All patients were immunocompromised state: 4 patients received immunosuppressive therapy for solid organ transplantation and 2 patients received chemotherapy for acute myeloid leukemia. Aspergillosis involved blood vessels (n = 3), liver (n = 2), spleen (n = 2), gastrointestinal tract (n = 2), native kidney (n = 1), transplanted kidney (n = 1), peritoneum (n = 1), and retroperitoneum (n = 1). CT demonstrated solid organ or bowel infarction or perforation secondary to vascular thrombosis or pseudoaneurysm, multiple low-attenuating lesions of solid organs presenting as abscesses, concentric bowel wall thickening mimicking typhlitis, or diffuse or nodular infiltration of the peritoneum and retroperitoneum. Conclusion: Familiarity with findings commonly presenting as angioinvasive features or abscesses on CT, may facilitate the diagnosis of rare and fatal abdominal aspergillosis.

  17. Fabrication Aware Form-finding

    DEFF Research Database (Denmark)

    Egholm Pedersen, Ole; Larsen, Niels Martin; Pigram, Dave

    2014-01-01

    This paper describes a design and construction method that combines two distinct material systems with fabrication aware form-finding and file-to-factory workflows. The method enables the fluent creation of complex materially efficient structures comprising high populations of geometrically uniqu...

  18. Novel Method of Detecting Movement of the Interference Fringes Using One-Dimensional PSD

    Directory of Open Access Journals (Sweden)

    Qi Wang

    2015-06-01

    Full Text Available In this paper, a method of using a one-dimensional position-sensitive detector (PSD by replacing charge-coupled device (CCD to measure the movement of the interference fringes is presented first, and its feasibility is demonstrated through an experimental setup based on the principle of centroid detection. Firstly, the centroid position of the interference fringes in a fiber Mach-Zehnder (M-Z interferometer is solved in theory, showing it has a higher resolution and sensitivity. According to the physical characteristics and principles of PSD, a simulation of the interference fringe’s phase difference in fiber M-Z interferometers and PSD output is carried out. Comparing the simulation results with the relationship between phase differences and centroid positions in fiber M-Z interferometers, the conclusion that the output of interference fringes by PSD is still the centroid position is obtained. Based on massive measurements, the best resolution of the system is achieved with 5.15, 625 μm. Finally, the detection system is evaluated through setup error analysis and an ultra-narrow-band filter structure. The filter structure is configured with a one-dimensional photonic crystal containing positive and negative refraction material, which can eliminate background light in the PSD detection experiment. This detection system has a simple structure, good stability, high precision and easily performs remote measurements, which makes it potentially useful in material small deformation tests, refractivity measurements of optical media and optical wave front detection.

  19. MRI finding of hemangioblastomas

    International Nuclear Information System (INIS)

    Park, Seung Cheol; Oh, Min Cheol; Chung, Hwan Hoon; Seol, Hye Young; Lee, Nam Joon; Kim, Jung Hyuk

    1994-01-01

    The purpose of this study is to evaluate the findings of magnetic resonance imaging (MRI) of posterior fossa hemanangioblastoma and usefulness of contrast enhancement with Gd-DTPA. Seven patients with posterior fossa hemangioblastoma were studied with both pre- and post-enhanced MRI. The MR images were reviewed regarding the location, size, signal intensities of cysts and mural nodules, and their contrast enhancement pattern. Five tumors were located in cerebellar hemisphere, one in vermis, and one in posterior part of medulla. One patient with von Hippel-Lindau disease had a medullary hemangioblastoma with multiple pancreatic cysts. In 6 cases, the major portion of the tumor was cysts and had small mulkal nodules. The solid portion was relatively lange in one cases, cemprising half of the tumor cysts were oval shaped and their sized were 3-6.7 cm in diameter. In five cases(71%), septations were noted within the cysts. Cysts were isointense or slightly hyperintense on T1-weighted image and hyperintense on T2- weighted image compared with cerebrospinal fluid. Mural nodules were oval or rounded radiotherapy had better prognosis than those treated with radiotherapy alwas 0.5-2.5 cm in diameter. Mural nodules were isointense to gray matter. They were detected in five cases on T1-weighted images and one case on T2-weighted images. In two cases, vascular signal void area was noted in mural nodules. On contrast-enhanced T1-weighted images, all mural nodules were intensely enhanced. MRI provide to be a good diagnostic method to detect and characterize posterior fossa hemangioblastoma. The most common finding is Cystic posterior fossa lesion with enhancing mural nodule. Contrast enhancement is essential for specific diagnosis

  20. Finding a Neurosurgeon

    Science.gov (United States)

    Tip: Finding A Neurosurgeon The first step in getting proper treatment for Chiari is to find the right doctor. While many patients are ... surgical, Conquer Chiari recommends that patients see a neurosurgeon for evaluation. As a policy, Conquer Chiari does ...

  1. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

    The problem of attribute reduction is an important problem related to feature selection and knowledge discovery. The problem of finding reducts with minimum cardinality is NP-hard. This paper suggests a new algorithm for finding exact reducts

  2. Find a Dermatologist

    Science.gov (United States)

    ... Practice Tools Education Meetings & Events Advocacy Public & Patients Find a Dermatologist Why see a dermatologist? Learn more . ... Last Name Search Special Proprietary Notice and Disclaimer "Find a Dermatologist" is produced by the American Academy ...

  3. Find din stemme

    DEFF Research Database (Denmark)

    Hansen, Jette Barnholdt

    2010-01-01

    Anmeldelse af Dorte Kock og Lene Kleinschmidts: Find din stemme. En brugsbog.Hans Reitzels Forlag 2010.......Anmeldelse af Dorte Kock og Lene Kleinschmidts: Find din stemme. En brugsbog.Hans Reitzels Forlag 2010....

  4. Metasynthesis findings: potential versus reality.

    Science.gov (United States)

    Finfgeld-Connett, Deborah

    2014-11-01

    Early on, qualitative researchers predicted that metasynthesis research had the potential to significantly push knowledge development forward. More recently, scholars have questioned whether this is actually occurring. To examine this concern, a randomly selected sample of metasynthesis articles was systematically reviewed to identify the types of findings that have been produced. Based on this systematic examination, it appears that findings from metasynthesis investigations might not be reaching their full potential. Metasynthesis investigations frequently result in isolated findings rather than findings in relationship, and opportunities to generate research hypotheses and theoretical models are not always fully realized. With this in mind, methods for moving metasynthesis findings into relationship are discussed. © The Author(s) 2014.

  5. Radiologic findings of sacroiliitis : emphasis on MR findings

    International Nuclear Information System (INIS)

    Yang, Ik; Park, Hai Jung; Lee, Yul; Chung, Soo Young; Park, Jong Ho

    1997-01-01

    To compare the characteristic MR findings of infectious sacroiliitis (IS) and ankylosing spondylitis (AS). We retrospectively reviewed MR findings in eight patients with IS (pyogenic in six, tuberculosis in two) confirmed by culture and clinical follow-up, and in six with AS by HLA-B27 typing. AA control group of 13 asymptomatic volunteers was formed, and they underwent MRI Findings were analysed for morphology, degree of bone erosion, and adjacent soft tissue change. CT findings of AS in four patients and IS in four were also compared to MR findings. MR characteristics of IS included unilaterality (100%), abnormal cartilage signal intensity (100%), bone marrow change (100%), contrast enhancement (100%), erosion (63%), and soft tissue change (63%). MR findings of AS showed bilaterality (67%), abnormal cartilage signal intensity (80%), bone marrow change (80%), erosion (80%), contrast enhancement (44%) and soft tissue change (10%). CT scan showed bony sclerosis and erosion (86%), and abnormal joint space (71%). MR findings of sacroiliitis were loss of thin zone of a cartilage and erosions on T1-weighted image, and increased signal intensity on T2-weighted image. MRI is regarded as a useful diagnostic method where conventional diagnosis is difficult, and is able to image cartilage abnormalities directly and noninvasively. Significant differences in MR findings between IS and AS were not noted, however

  6. Finding beam focus errors automatically

    International Nuclear Information System (INIS)

    Lee, M.J.; Clearwater, S.H.; Kleban, S.D.

    1987-01-01

    An automated method for finding beam focus errors using an optimization program called COMFORT-PLUS. The steps involved in finding the correction factors using COMFORT-PLUS has been used to find the beam focus errors for two damping rings at the SLAC Linear Collider. The program is to be used as an off-line program to analyze actual measured data for any SLC system. A limitation on the application of this procedure is found to be that it depends on the magnitude of the machine errors. Another is that the program is not totally automated since the user must decide a priori where to look for errors

  7. Thoracic textilomas: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Machado, Dianne Melo; Zanetti, Glaucia; Araujo Neto, Cesar Augusto; Nobre, Luiz Felipe; Meirelles, Gustavo de Souza Portes; Silva, Jorge Luiz Pereira e; Guimaraes, Marcos Duarte; Escuissato, Dante Luiz; Souza Junior, Arthur Soares; Hochhegger, Bruno; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Hospital Universitario Antonio Pedro (HUAP/UFF), Niteroi, RJ (Brazil)

    2014-09-15

    Objective: the aim of this study was to analyze chest CT scans of patients with thoracic textiloma. Methods: this was a retrospective study of 16 patients (11 men and 5 women) with surgically confirmed thoracic textiloma. The chest CT scans of those patients were evaluated by two independent observers, and discordant results were resolved by consensus. Results: the majority (62.5%) of the textilomas were caused by previous heart surgery. The most common symptoms were chest pain (in 68.75%) and cough (in 56.25%). In all cases, the main tomographic finding was a mass with regular contours and borders that were well-defined or partially defined. Half of the textilomas occurred in the right hemithorax and half occurred in the left. The majority (56.25%) were located in the lower third of the lung. The diameter of the mass was ≤ 10 cm in 10 cases (62.5%) and > 10 cm in the remaining 6 cases (37.5%). Most (81.25%) of the textilomas were heterogeneous in density, with signs of calcification, gas, radiopaque marker, or sponge-like material. Peripheral expansion of the mass was observed in 12 (92.3%) of the 13 patients in whom a contrast agent was used. Intraoperatively, pleural involvement was observed in 14 cases (87.5%) and pericardial involvement was observed in 2 (12.5%). Conclusions: it is important to recognize the main tomographic aspects of thoracic textilomas in order to include this possibility in the differential diagnosis of chest pain and cough in patients with a history of heart or thoracic surgery, thus promoting the early identification and treatment of this postoperative complication. (author)

  8. Finding Rising and Falling Words

    NARCIS (Netherlands)

    Tjong Kim Sang, E.

    2016-01-01

    We examine two different methods for finding rising words (among which neologisms) and falling words (among which archaisms) in decades of magazine texts (millions of words) and in years of tweets (billions of words): one based on correlation coefficients of relative frequencies and time, and one

  9. Ultrasonographic findings of cataract

    International Nuclear Information System (INIS)

    Choi, Sun Seob; Kim, Yang Soo; Lee, Kwan Seh; Kim, Kun Sang

    1985-01-01

    Examining the eye with high resolution ultrasonography, authors encountered 34 cases (41 eyeballs) of cataract and found out its characteristic ultrasonographic findings, though cataract is easily recognized by physician on inspection. Ultrasonographic findings of cataract were as follows; 1. Thickening of lens due to edema. 2. Demonstration of lens echo in whole circumference. 3. Multiple internal lens echo

  10. Radiologic findings of anthracofibrosis

    International Nuclear Information System (INIS)

    Yoon, Mi Jin; Ko, Eun Joo; Yoon, Sook Ja; Tien, Kuang Lung; Yoon, Yong Kyu; Lee, Kyung Soo; Kim, Jin Hwan

    1998-01-01

    To evaluate the CT findings of bronchial anthracofibrosis. Fourteen patients with bronchoscopically confirmed anthracofibrosis were involved in this study. CT findings (n=3D12) were retrospectively analysed; the pattern, distri-bution and extent of bronchial and parenchymal abnormalities and additional findings such as mediastinal lymphadenopathy and pleural effusion were assessed. Age, sex, and occupational and disease history were history were also reviewed. Patients were aged between 63 and 95 (mean, 71.3) years, and ten were female. Only one patient had an occupational history, but four had a history of pulmonary tuberculosis. Frequent radiologic findings were bronchial wall thickening(n=3D6), atelectasis(n=3D8), mediastinal lymphad-enopathy(n=3D7) and mass(n=3D4). Other accompanying findings were bronchial wall calcification(n=3D3), consolidation(n=3D2) and pleural effusion(n=3D2). Right upper (n=3D7) and right middle lobe(n=3D7) were the most commonly involved sites, and multifocal involvement (n=3D7) was frequent. Bronchial wall thickening, atelectasis and mediastinal lymphadenopathy were characteristic CT findings of anthracofibrosis. When such findings are noted in older or aged female patients, anthracofibrosis should be included in the differential diagnosis

  11. Dermoscopic findings in cicatricial alopecia

    Directory of Open Access Journals (Sweden)

    Seher Arı

    2013-12-01

    Full Text Available Background: Dermoscopy is an important tool for the diagnosis of pigmented skin lesions. Newly, this method has also been used in the diagnosis and follow-up hair and scalp disorders. Objective: The objective of this study was to investigate dermoscopic findings in a sample of patients with clinical and histopathological compatible with cicatricial alopecia. Methods: Twenty nine patients with cicatricial alopecia diagnosed by clinical and histological findings were examined by dermoscopy.. Results: Dermoscopic features evaluated included folliculitis decalvans (n=8, pseudopelade of Brocq (n=7, lichen planopilaris (n=6, discoid lupus erythematosus (n=2, dissecting cellulitis (n=1, and secondary cicatricial alopecia (n=5. Visualization of structures previously examined with naked eye were seen in great detail with dermoscopy. The loss of follicular orifices was seen in all patients with cicatricial alopecia. Perifollicular scaling, arborizing red lines, honeycomb pigment pattern, white dots and tufted hairs were the other most obvious findings. Conclusion: Use of dermoscopy in the clinical evaluation of cicatrical alopecia improves diagnostic capability beyond simple clinic inspection, but larger studies correlating dermoscopic findings with histopathology exams are needed to improve understanding of this method.

  12. Finding the Right Doctor

    Science.gov (United States)

    ... certified hospital Communicating with Healthcare Professionals for Caregivers Consumer Health Care • Home • Health Insurance Information • Your Healthcare Team Introduction Finding the Right Doctor Talking to Your Doctor Getting a Second ...

  13. Hepatic encephalopathy. Imaging Findings

    International Nuclear Information System (INIS)

    Carrillo, Maria Claudia; Bermudez Munoz, Sonia; J Morillo, Anibal

    2007-01-01

    Hepatic encephalopathy occurs in patients with chronic hepatic insufficiency and can produce abnormalities in the central nervous system, which can be observed in MRI studies. Traditionally, these imaging findings include symmetrical hyper intensities in T1-weighted sequences in the basal ganglia (mainly globus pallidus), involving also the substantia nigra, mesencephalic tegmentum, frontal and occipital cortex. These areas appear of normal intensity in T2-weighted imaging sequences. Other entities that can lead to similar findings include manganese intoxication and type-1 neurofibromatosis. Currently, with the advent of MR spectroscopy, abnormalities in patients with clinical and subclinical hepatic encephalopathy have been described. After hepatic transplantation, hyper intensities of the basal ganglia and the MR spectroscopic findings may disappear within 3 months to 1 year, suggesting a functional, more than a structural damage. This article will demonstrate the MR findings of patients with hepatic encephalopathy due to chronic hepatic insufficiency.

  14. Find a Doctor

    Science.gov (United States)

    ... Spira Galifianakis Gallagher Galvez-Jimenez Gancher Garnett Garrett Gates Gayton Gaziano Gelb Geleris George Gerber Gerlach Germano ... Donate Donate Online Membership Find an Event Donor Bill of Rights About Dystonia Symptoms & Diagnosis Forms of ...

  15. Find a Doctor

    Science.gov (United States)

    ... Manager Book Appointments Getting Care When on Active Duty Getting Care When Traveling What's Covered Health Care Dental Care ... Manager Book Appointments Getting Care When on Active Duty Getting Care When Traveling Bread Crumbs Home Find a Doctor ...

  16. CT findings of colonic diverticulitis

    International Nuclear Information System (INIS)

    Sasaki, Shigeru; Ohba, Satoru; Mizutani, Masaru

    1998-01-01

    Although colonic diverticulitis has no indication for operation, but in some mistaken cases were operated with a diagnosis of acute appendicitis. We evaluated the CT findings of colonic diverticulitis about 19 cases and of asymptomatic colonic diverticula about 15 cases retrospectively. Diagnosis was confirmed of barium enema and operation. CT are complementary methods of examination that can delineated the range of thickening of the colon and the extension of inflammatory changes around the colon. We also believe that CT findings of colonic diverticulitis are useful for differentiating from a diagnosis of appendicitis. (author)

  17. Finding Maximal Pairs with Bounded Gap

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Lyngsø, Rune B.; Pedersen, Christian N. S.

    1999-01-01

    . In this paper we present methods for finding all maximal pairs under various constraints on the gap. In a string of length n we can find all maximal pairs with gap in an upper and lower bounded interval in time O(n log n+z) where z is the number of reported pairs. If the upper bound is removed the time reduces...... to O(n+z). Since a tandem repeat is a pair where the gap is zero, our methods can be seen as a generalization of finding tandem repeats. The running time of our methods equals the running time of well known methods for finding tandem repeats....

  18. Finding Maximal Quasiperiodicities in Strings

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Pedersen, Christian N. S.

    2000-01-01

    of length n in time O(n log n) and space O(n). Our algorithm uses the suffix tree as the fundamental data structure combined with efficient methods for merging and performing multiple searches in search trees. Besides finding all maximal quasiperiodic substrings, our algorithm also marks the nodes......Apostolico and Ehrenfeucht defined the notion of a maximal quasiperiodic substring and gave an algorithm that finds all maximal quasiperiodic substrings in a string of length n in time O(n log2 n). In this paper we give an algorithm that finds all maximal quasiperiodic substrings in a string...... in the suffix tree that have a superprimitive path-label....

  19. Ultrasonographic findings of gynecomastia

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Ji Hyung; Oh, Ki Keun; Yoon, Choon Sik; Park, Chang Yun [Yongdong Severance Hospital, Seoul (Korea, Republic of)

    1993-12-15

    The purposes of our study were to find out characteristic ultrasonographic findings of gynecomastia and to analyze age distribution, causative factors of gynecomastia. For these purposes, medical records of 39 male patients with gynecomastia were reviewed and sonographic findings of 13 cases of gentamycin were analyzed. Gynecomastia was found most commonly in teenagers and commonly in twenties. Almostly, it occurred without any evident etiology and classified as idiopathic or pirbuterol type. Less frequently, it occurred due to drug administration, systemic disease, or male hormone deficiency. Unilateral involvement was seen in 29 cases; 17cases involving the left and 12 cases the right. Bilateral involvement was seen in 10 cases. Sonographically,gynecomastia appeared as hypoechoic or intermediate echoic mass with various shape in the subareolar area. One case showed diffuse fatty breast pattern without definable mass. On sonographic evaluation, prominent nipple should not be misinterpreted as a breast mass. For the correct diagnosis of gynecomastia, both side breasts should be evaluated for comparison

  20. Effective Bug Finding

    DEFF Research Database (Denmark)

    Rivas, Iago Abal

    Lightweight bug finders (also known as code scanners) are becoming popular, they scale well and can find simple yet common programming errors. It is now considered a good practice to integrate these tools as part of your development process. The Linux project, for instance, has an automated testing...... service, known as the Kbuild robot, that runs a few of these code scanners. In this project, I have carefully studied tens of historical Linux bugs, and I have found that many of these bugs, despite being conceptually simple, were not caught by any code scanning tool. The reason is that, by design, code...... scanners will find mostly superficial errors. Thus, when bugs span multiple functions, even if simple, they become undetectable by most code scanners. The studied set of historical bugs contained many of such cases. This PhD thesis proposes a bug-finding technique that is both lightweight and capable...

  1. Mobious syndrome: MR findings

    Directory of Open Access Journals (Sweden)

    Maskal Revanna Srinivas

    2016-01-01

    Full Text Available Möbius syndrome is an extremely rare congenital disorder. We report a case of Möbius syndrome in a 2-year-old girl with bilateral convergent squint and left-sided facial weakness. The characteristic magnetic resonance imaging (MRI findings of Möbius syndrome, which include absent bilateral abducens nerves and absent left facial nerve, were noted. In addition, there was absence of left anterior inferior cerebellar artery (AICA and absence of bilateral facial colliculi. Clinical features, etiology, and imaging findings are discussed.

  2. Finding optimal exact reducts

    KAUST Repository

    AbouEisha, Hassan M.

    2014-01-01

    The problem of attribute reduction is an important problem related to feature selection and knowledge discovery. The problem of finding reducts with minimum cardinality is NP-hard. This paper suggests a new algorithm for finding exact reducts with minimum cardinality. This algorithm transforms the initial table to a decision table of a special kind, apply a set of simplification steps to this table, and use a dynamic programming algorithm to finish the construction of an optimal reduct. I present results of computer experiments for a collection of decision tables from UCIML Repository. For many of the experimented tables, the simplification steps solved the problem.

  3. Neuroimaging findings in movement disorders

    International Nuclear Information System (INIS)

    Topalov, N.

    2015-01-01

    Full text: Neuroimaging methods are of great importance for the differential diagnostic delimitation of movement disorders associated with structural damage (neoplasms, ischemic lesions, neuroinfections) from those associated with specific pathophysiological mechanisms (dysmetabolic disorders, neurotransmitter disorders). Learning objective: Presentation of typical imaging findings contributing to nosological differentiation in groups of movement disorders with similar clinical signs. In this presentation are discussed neuroimaging findings in Parkinson‘s disease, atypical parkinsonian syndromes (multiple system atrophy, progressive supranuclear palsy, corticobasal degeneration), parkinsonism in genetically mediated diseases (Wilson’s disease, pantothenate kinase-associated neurodegeneration – PKAN), vascular parkinsonism, hyperkinetic movement disorders (palatal tremor, Huntington‘s chorea, symptomatic chorea in ischemic stroke and diabetes, rubral tremor, ballismus, hemifacial spasm). Contemporary neuroimaging methods enable support for diagnostic and differential diagnostic precision of a number of hypo- and hyperkinetic movement disorders, which is essential for neurological clinical practice

  4. Circumcenter, Circumcircle and Centroid of a Triangle

    OpenAIRE

    Coghetto Roland

    2016-01-01

    We introduce, using the Mizar system [1], some basic concepts of Euclidean geometry: the half length and the midpoint of a segment, the perpendicular bisector of a segment, the medians (the cevians that join the vertices of a triangle to the midpoints of the opposite sides) of a triangle.

  5. Circumcenter, Circumcircle and Centroid of a Triangle

    Directory of Open Access Journals (Sweden)

    Coghetto Roland

    2016-03-01

    Full Text Available We introduce, using the Mizar system [1], some basic concepts of Euclidean geometry: the half length and the midpoint of a segment, the perpendicular bisector of a segment, the medians (the cevians that join the vertices of a triangle to the midpoints of the opposite sides of a triangle.

  6. Center for Research on Infrared Detectors (CENTROID)

    Science.gov (United States)

    2006-09-30

    of growth, x is also monitored in situ by SE, and Tis measured by a thermocouple, a pyrometer and indirectly by the heating power and is calibrated...Polar optical, acoustic , and inter-valley phonon scattering are included, as wells as scattering from the quantum dots. The simulation includes

  7. Primary cerebral lymphoma: radiological findings

    International Nuclear Information System (INIS)

    Ruiz, J.C.; Grandse, D.; Equidazu, J.; Elizagaray, E.; Grande, J.; Carrandi, J.

    1990-01-01

    We present four cases of primary cerebral lymphoma in non-immunodepressed adult patients. All cases were dsemonstrated with pathological study. CAT study showed solitary or multiple isodense lesions, which incorporated avidly and homoneneously the contrast. Arteriography performed in three patients and magnetic resonance, performed in one did not help for diagnosis. We also review the radiological findings obtained with different imaging methods, and suggest the criteria which could be useful for early diagnosis (Author)

  8. Finding Their Identities

    Science.gov (United States)

    Lum, Lydia

    2009-01-01

    Every time Dr. Larry Shinagawa teaches his "Introduction to Asian American Studies" course at the University of Maryland (UMD), College Park, he finds that 10 to 20 percent of his students are adoptees. Among other things, they hunger to better comprehend the social and political circumstances overseas leading to their adoption. In…

  9. Neuroblastoma: computed tomographic findings

    International Nuclear Information System (INIS)

    Yoon, Choon Sik; Ahn, Chang Su; Kim, Myung Jun; Oh, Ki Keun

    1994-01-01

    To evaluate the characteristic CT findings of neuroblastoma, we studied neuroblastomas. We analysed CT findings of available 25 cases among pathologically proved 51 neuroblastomas from Jan. 1983 to Sept. 1990. The most frequent site of origin is adrenal gland (40%) and the second is retroperitoneum (32%) and the third ismediastinum (16%). Characteristic CT findings are as follows: Calcifications within the tumor is detected in 86% of abdominal neuroblastomas and 50% of mediastinal origin. Hemorrhagic and necrotic changes within the tumor is noted at 86% in the tumor of abdominal origin and 25% in mediastinal neuroblastomas. Contrast enhanced study showed frequently seperated enhanced appearance with/without solid contrast enhancement. Encasements of major great vessels such as aorta and IVC with/without displacement by metastatic lymph nodes or tumor are frequently seen in 90% of abdominal neuroblastomas. Multiple lymphadenopathy are detected in 95% of abdominal neuroblastomas and 25% of mediastinal neuroblastomas. The most common organ or contiguous direct invasion is kidney in 6 cases and the next one is liver but intraspinal canal invasion is also noted in 2 cases. We concluded that diagnosis of neuroblastoma would be easily obtained in masses of pediatric group from recognition of above characteristic findings

  10. Swarm: robust and fast clustering method for amplicon-based studies

    Science.gov (United States)

    Rognes, Torbjørn; Quince, Christopher; de Vargas, Colomban; Dunthorn, Micah

    2014-01-01

    Popular de novo amplicon clustering methods suffer from two fundamental flaws: arbitrary global clustering thresholds, and input-order dependency induced by centroid selection. Swarm was developed to address these issues by first clustering nearly identical amplicons iteratively using a local threshold, and then by using clusters’ internal structure and amplicon abundances to refine its results. This fast, scalable, and input-order independent approach reduces the influence of clustering parameters and produces robust operational taxonomic units. PMID:25276506

  11. Swarm: robust and fast clustering method for amplicon-based studies

    Directory of Open Access Journals (Sweden)

    Frédéric Mahé

    2014-09-01

    Full Text Available Popular de novo amplicon clustering methods suffer from two fundamental flaws: arbitrary global clustering thresholds, and input-order dependency induced by centroid selection. Swarm was developed to address these issues by first clustering nearly identical amplicons iteratively using a local threshold, and then by using clusters’ internal structure and amplicon abundances to refine its results. This fast, scalable, and input-order independent approach reduces the influence of clustering parameters and produces robust operational taxonomic units.

  12. Effective Bug Finding

    DEFF Research Database (Denmark)

    Rivas, Iago Abal

    Lightweight bug finders (also known as code scanners) are becoming popular, they scale well and can find simple yet common programming errors. It is now considered a good practice to integrate these tools as part of your development process. The Linux project, for instance, has an automated testing...... service, known as the Kbuild robot, that runs a few of these code scanners. In this project, I have carefully studied tens of historical Linux bugs, and I have found that many of these bugs, despite being conceptually simple, were not caught by any code scanning tool. The reason is that, by design, code...... by matching temporal bug-patterns against the control-flow graph of this program abstraction. I have implemented a proof-of-concept bug finder based on this technique, EBA, and confirmed that it is both scalable and effective at finding bugs. On a benchmark of historical Linux double-lock bugs, EBA was able...

  13. MR findings of craniopharyngioma

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Moon; Woo, Young Hoon; Joo, Yang Goo; Suh, Soo Jhi [College of Medicine, Keimyung University, Daegu (Korea, Republic of)

    1992-11-15

    Craniopharyngioma is a benign, slow-growing tumor that constitues 3-9% of all intracranial tumors, and arises from epithelial remnants of the Rathke's pouch. We analyzed MR (2.0T) findings of ten cases with surgically proved craniopharyngioma retrospectively. CT was available in five cases, and Gd-DTPA was used in six cases. Characteristic findings of craniopharyngioma in MRI included multilocularity and variable signal intensities within each loculus that were more prominent in T1WI. Detection rate of calcification in MR was 60%. Six cases with Gd-DTPA enhancement revealed irregular or rim-like enhancement. MRI provides useful information regarding the location, extent and biochemical characteristics of the oraniopharyngioma as well as its relationship to the neighboring structures which will be valuable in planning surgical resection.

  14. MR findings of craniopharyngioma

    International Nuclear Information System (INIS)

    Lee, Sung Moon; Woo, Young Hoon; Joo, Yang Goo; Suh, Soo Jhi

    1992-01-01

    Craniopharyngioma is a benign, slow-growing tumor that constitues 3-9% of all intracranial tumors, and arises from epithelial remnants of the Rathke's pouch. We analyzed MR (2.0T) findings of ten cases with surgically proved craniopharyngioma retrospectively. CT was available in five cases, and Gd-DTPA was used in six cases. Characteristic findings of craniopharyngioma in MRI included multilocularity and variable signal intensities within each loculus that were more prominent in T1WI. Detection rate of calcification in MR was 60%. Six cases with Gd-DTPA enhancement revealed irregular or rim-like enhancement. MRI provides useful information regarding the location, extent and biochemical characteristics of the oraniopharyngioma as well as its relationship to the neighboring structures which will be valuable in planning surgical resection

  15. Heterotopic pregnancy: Sonographic findings

    International Nuclear Information System (INIS)

    Kwon, Tae Hee

    1999-01-01

    To evaluate the sonographic findings of the heterotopic pregnancy which is increasing recently. Thirty-nine cases of heterotopic pregnancy after ovulation induction and IVF-ET (In Vitro Fertilization-Embryo Transfer) during the recent 3 years were analyzed. They were diagnosed by ultrasonography and proved surgically afterwards. Sonographic findings were analyzed focusing on gestational week of intrauterine pregnancy and location of ectopic pregnancy. In particular, adnexal mass was evaluated with regard to size and the characteristic findings such as ectopic gestational sac (echogenic ring). Also, overian cyst and fluid collection in cul-de-sac space were reviewed carefully. Heterotopic pregnancy was proved surgically by salpingectomy in 33 cases and by resection of cornus in six cases. Sonographic diagnosis using transvaginal ultrasound was made from five weeks to nine weeks two days (six weeks and four days in average) from last menstral period in all 39 cases. Ectopic pregnancy was identified in ampullary part in 29 cases, in the isthmic portion of tube in four cases and in the cornus of uterus in six cases. The intrauterine pregnancy was diagnosed by identifying the intrauterine gestational saccontaining a yolk sac in seven cases and the embryo with fetal heart beat in the remaining 32 cases. Adnexal masses of heterotopic pregnancy were less than 3 cm in diameter in 2 cases (57%), 3-4 cm in 11 cases (28%) and more than 4 cm in 6 cases (15%). A characteristic finding of ectopic mass was echogenic ring which was visible in 33 (84.6%) cases by transvaginal ultrasound. Six cases had pelvic hematosalpinx and two had pelvic hematoma. Of 10 cases (26%) which were identified to have ovarian hyperstimulation syndrome, eight (21%) had large amount of fluid collection in cul-de-sac and abdomen. Ultrasonographic identification of the intrauterine pregnancy and the ectopic chorion ring is effective for the early diagnosis of the heterotopic pregnancy.

  16. MELAS syndrome: neuroradiological findings

    International Nuclear Information System (INIS)

    Cano, A.; Romero, A. I.; Bravo, F.; Vida, J. M.; Espejo, S.

    2002-01-01

    To assess the computed tomography (CT) and magnetic resonance (MR) findings in MELAS syndrome (mitochondrial encephalomyopathy, lactic acidosis and stroke-like episodes) and their contribution to the diagnosis of this entity. We present three patients in which a diagnosis of MELAS syndrome was confirmed by muscle biopsy. CT revealed pathological findings in two patients: bilateral calcifications in the basal nuclei in one and low-attenuation lesions in occipital lobes in the other. Initial or follow-up MR demonstrated pathological findings highly suggestive of MELAS syndrome in all the patients. They consisted of hyperintense lesions in T2-weighted images, located predominantly in the cortex of occipital and parietal lobes. Cerebellar atrophy was also observed in two patients. The clinical signs varied, but epileptic seizures, headache, vomiting, ataxia, muscle weakness and pyramidal involvement were among the major ones. Only one patient presented high lactic acid levels, and in two, the initial muscle biopsy was not conclusive enough to provide the definitive diagnosis. CT and, especially, MR are useful tools in the diagnosis of MELAS syndrome, particularly in those cases in which initial negative laboratory and histological results make diagnosis difficult. (Author) 21 refs

  17. CT findings of slilcosis

    International Nuclear Information System (INIS)

    Jung, Dong Hee; Kim, Kun Il; Son, Hyun Ju; Ro, Young Jin; Jung, Doo Young; Park, Jae Yeong; Lee, Jun Woo; Kim, Byung Soo

    1996-01-01

    To describe chest radiographic and CT findings of silicosis, and to compare their findings. Ten coal miners and six stonemasons were included in this study. All were male and their mean age was 53.1. The mean duration of dust exposure was 15.2 years(range, 5-30 years) in coal miners and 25.3 years(range, 15-35 years) in stonemasons. Chest radiographs(n=16), conventional CT scans(n=4), and high resolution CT(HRCT) scans(n=13) were evaluated. Parenchymal abnormalities were interpreted on the basis of ILO standard films(1980) in chest radiographs and on the basis of CAP(College of American Pathologists, 1979) in CT(HRCT) films. Chest radiographs revealed large opacities(n=8), small opacities(n=6), and normal findings(n=2). Type r(n=4) and category 1/1(n=2) were most common for small opacities, while for large opacities, category B(n=4) and category c(n=4) were most common. These small and large opacities were located predominantly in the area of the upper and middle lung. Associated findings were emphysema(n=7), eggshell nodal calcifications(n=3), pneumothorax(n=3), C-P angle blunting(n=4), and pleural thickening(n=1). CT scans revealed micronodules(n=16), nodules(n=3), and progressive massive fibrosis(PMF, n=8). All these lesions were located in the upper and middle lungs, especially in the central portion of the posterior lung. PMF showed diffuse and homogenous(n=3) and puntate(n=2) calcifications, cavitations(n=5), air bronchograms(n=3), and necrosis(n=1). Peripheral paracicatrical emphysema was associated with PMF(n=8). Other findings were pneumothorax(n=4), emphysema(n=10), hilar and mediastinal nodal enlargement(n=11) bronchial wall thick- enings(n=6), bronchiectasis(n=1), pleural thickening(n=7), parenchymal fibrosis(n=1), and pulmonary tuberculosis(n=2). Small and large opacities in chest radiographs and micronodules, nodules, and PMFs in CT (HRCT) films were located predominately in the upper and middle lungs, especially in the central portion of the

  18. Radiological findings in NAO syndrome

    Energy Technology Data Exchange (ETDEWEB)

    Al-Otaibi, Leftan; Hugosson, Claes O. [Department of Radiology, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia); Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea' am; Bahabri, Sultan [Department of Paediatrics, King Faisal Specialist Hospital and Research Center, Riyadh (Saudi Arabia)

    2002-07-01

    Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

  19. Radiological findings in NAO syndrome

    International Nuclear Information System (INIS)

    Al-Otaibi, Leftan; Hugosson, Claes O.; Al-Mayouf, Sulalman M.; Majeed, Mahmoud; Al-Eid, Wea'am; Bahabri, Sultan

    2002-01-01

    Background: Diseases exhibiting osteolysis in children are rare hereditary conditions. Several types have been recognised with different clinical manifestations. One type includes subcutaneous nodules, arthropathy and osteolysis and has been termed NAO syndrome. Previous radiological reports have described the affected bones, usually the carpal and tarsal regions, but a detailed analysis of the radiological findings of both the axial as well as the appendicular skeleton has not been reported. Objectives: To describe the radiological findings in a large group of children with an autosomal recessive disease characterized by nodules, familial arthropathy and osteolysis. Materials and methods: The study comprises 14 patients from 9 families and all patients had the triad of nodulosis, arthropathy and osteolysis (NAO). Results: The most common radiological manifestations were osteopenia, undertubulation of long bones, arthritic changes, sclerotic sutures of the calvaria, osteolysis and muscle contractures. Other common findings were squared vertebrae, broad medial clavicles and brachycephaly. Progress of disease was documented in more than half of the patients. Conclusions: Our study is the first report of the detailed radiological findings of NAO syndrome. In NAO syndrome, both the axial and appendicular skeleton are involved (orig.)

  20. MR findings of ulegyria

    International Nuclear Information System (INIS)

    Momoshima, Suketaka; Shiga, Hayao; Yuasa, Yuji; Imai, Yutaka; Higuchi, Nobuya; Maezawa, Mariko.

    1991-01-01

    Magnetic resonance (MR) findings of the brains diagnosed to have ulegyria were reviewed. The reviewed subjects comprised six epileptic children, ranged from 2 to 16 years of age. All patients had convulsion of tonic-clonic type of various severity and had histories of ischemic-hypoxic or hypoglycemic episode in the perinatal or postnatal period. T 1 -weighted images demonstrated the findings precisely reflecting the salient macroscopic features of ulegyria; localized atrophy of the brain with mushroom-shaped cortical gyri with narrow roots and relatively spared wider crowns. T 2 -weighted images showed the areas of hyperintensity in the subcortical and deep white matter subjacent to the atrophic cortex, suggestive of cicatrical gliosis as well as cystic degeneration. The atrophic gyri were seen in the anterior and/or posterior parasagittal arterial border zones bilaterally with minimal asymmetry. Although these findings were nearly pathognomonic to ulegyria, polymicrogyria could mimic it since both are characterized by abnormally diminutive cortical gyri seen in epileptic children. In polymicrogyria, however, affected gyri are uniformly diminutive and not mushroom-shaped, the cortex is rather thickened than atrophic, the underlying white matter shows no focal hyperintensity, subcortical cystic changes are not present, and affected cortex is not restricted to arterial border zones. Even in one of our cases with extensive ulegyria, it was easy to differentiate it from polymicrogyria since parasagittal regions were most severely affected. Although the previous reports on ulegyria have been exclusively based on postmortem pathological examinations or experimental models, its easy recognition on MRI would contribute to further understanding of its clinical significance and mechanisms. (author)

  1. MR findings of spondylolysis

    International Nuclear Information System (INIS)

    Ojiri, Hiroya; Fukuda, Kunihiko; Hashimoto, Toru; Doi, Michiko; Irie, Takeo; Tatsuno, Satoshi; Tada, Shinpei; Toyoda, Keiko.

    1994-01-01

    We reviewed MR images of 50 patients with spondylolisthesis to disclose MR findings of spondylolysis. In almost half of our series, spondylolysis was detected as a low signal intensity band traversing in the pairs interarticularis on both T1 and T2 weighted images. Sagittal images was superior to axial image in detection of the low signal intensity band. In some patients, a focal high signal intensity accompanying the low signal intensity band was considered to be fluid collection within pseudoarthrosis due to spondylolysis on T2-weighted image. (author)

  2. MR findings of spondylolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ojiri, Hiroya; Fukuda, Kunihiko; Hashimoto, Toru; Doi, Michiko; Irie, Takeo; Tatsuno, Satoshi; Tada, Shinpei (Jikei Univ., Tokyo (Japan). School of Medicine); Toyoda, Keiko

    1994-08-01

    We reviewed MR images of 50 patients with spondylolisthesis to disclose MR findings of spondylolysis. In almost half of our series, spondylolysis was detected as a low signal intensity band traversing in the pairs interarticularis on both T1 and T2 weighted images. Sagittal images was superior to axial image in detection of the low signal intensity band. In some patients, a focal high signal intensity accompanying the low signal intensity band was considered to be fluid collection within pseudoarthrosis due to spondylolysis on T2-weighted image. (author).

  3. [Ultrasound findings in rhabdomyolysis].

    Science.gov (United States)

    Carrillo-Esper, Raúl; Galván-Talamantes, Yazmin; Meza-Ayala, Cynthia Margarita; Cruz-Santana, Julio Alberto; Bonilla-Reséndiz, Luis Ignacio

    Rhabdomyolysis is defined as skeletal muscle necrosis. Ultrasound assessment has recently become a useful tool for the diagnosis and monitoring of muscle diseases, including rhabdomyolysis. A case is presented on the ultrasound findings in a patient with rhabdomyolysis. To highlight the importance of ultrasound as an essential part in the diagnosis in rhabdomyolysis, to describe the ultrasound findings, and review the literature. A 30 year-old with post-traumatic rhabdomyolysis of both thighs. Ultrasound was performed using a Philips Sparq model with a high-frequency linear transducer (5-10MHz), in low-dimensional scanning mode (2D), in longitudinal and transverse sections at the level of both thighs. The images obtained showed disorganisation of the orientation of the muscle fibres, ground glass image, thickening of the muscular fascia, and the presence of anechoic areas. Ultrasound is a useful tool in the evaluation of rhabdomyolysis. Copyright © 2015 Academia Mexicana de Cirugía A.C. Publicado por Masson Doyma México S.A. All rights reserved.

  4. Ultrasonographic findings of Epicondylitis

    International Nuclear Information System (INIS)

    Kwak, Seo Hyun; Song, In Sup; Lee, Jong Beum; Lee, Hwa Yeon; Yoo, Seung Min; Yang, Seong Jun; Seo, Kyung Mook

    2002-01-01

    To evaluate the usefulness of ultrasonographic findings of the common extensor and flexor tendon in evaluation of patients with lateral and medial epicondylitis. Thirty eight elbows from twenty four patients (mean age=45.2 years) were included. Ultrasonographic examination was performed to evaluate lateral or medial epicondylitis. Epicondylitis was divided into five groups according to the severity of disease: 1) normal, 2) tendinopathy, 3) tendinopathy with a partial tear, partial tear and 4) complete tear. Change in the size of a tendon, bony change of the epicondylitis, presence or absence of calcification or echogenic foci in the common tendon and hypervascularity for each categories were also assessed. In addition, these lesions were divided into the superficial and deep according to the location of lesions. According to the severity, there were 15 cases of normal, 13 tendinopathies, 8 tendinopathies with a partial tear, 2 partial tears and 0 complete tear. Bony change was seen only in tendinopathy, tendinopathy with partial tear and partial tear. Calcification or echogenic foci were only observed in cases with tendinopathy and tendinopathy with partial tear. Hypervascularity was only seen in one case of tendinopathy. With thorough understanding of ultrasonographic findings of epicondylitis, ultrasonographic examination can be especially useful and effective in evaluating the severity and location of lesions.

  5. Ultrasonographic findings of Epicondylitis

    Energy Technology Data Exchange (ETDEWEB)

    Kwak, Seo Hyun; Song, In Sup; Lee, Jong Beum; Lee, Hwa Yeon; Yoo, Seung Min; Yang, Seong Jun [Yong San Hospital, Chung-Ang University College of Medicine, Seoul (Korea, Republic of); Seo, Kyung Mook [Chung-Ang University College of Medicine, Seoul (Korea, Republic of)

    2002-09-15

    To evaluate the usefulness of ultrasonographic findings of the common extensor and flexor tendon in evaluation of patients with lateral and medial epicondylitis. Thirty eight elbows from twenty four patients (mean age=45.2 years) were included. Ultrasonographic examination was performed to evaluate lateral or medial epicondylitis. Epicondylitis was divided into five groups according to the severity of disease: 1) normal, 2) tendinopathy, 3) tendinopathy with a partial tear, partial tear and 4) complete tear. Change in the size of a tendon, bony change of the epicondylitis, presence or absence of calcification or echogenic foci in the common tendon and hypervascularity for each categories were also assessed. In addition, these lesions were divided into the superficial and deep according to the location of lesions. According to the severity, there were 15 cases of normal, 13 tendinopathies, 8 tendinopathies with a partial tear, 2 partial tears and 0 complete tear. Bony change was seen only in tendinopathy, tendinopathy with partial tear and partial tear. Calcification or echogenic foci were only observed in cases with tendinopathy and tendinopathy with partial tear. Hypervascularity was only seen in one case of tendinopathy. With thorough understanding of ultrasonographic findings of epicondylitis, ultrasonographic examination can be especially useful and effective in evaluating the severity and location of lesions.

  6. Climate change: Recent findings

    International Nuclear Information System (INIS)

    Hesselmans, G.H.F.M.

    1993-08-01

    In the late eighties several reports have been published on climate change and sea level rise. In the meantime insights may have changed due to the availability of better and more observations and/or more advanced climate models. The aim of this report is to present the most recent findings with respect to climate change, in particular of sea level rise, storm surges and river peak flows. These climate factors are important for the safety of low-lying areas with respect to coastal erosion and flooding. In the first chapters a short review is presented of a few of the eighties reports. Furthermore, the predictions by state of the art climate models at that time are given. The reports from the eighties should be considered as 'old' information, whereas the IPCC supplement and work, for example, by Wigley should be considered as new information. To assess the latest findings two experts in this field were interviewed: dr J. Oerlemans and dr C.J.E. Schuurmans, a climate expert from the Royal Netherlands Meteorological Institute (KNMI). Their views are presented together with results published in recent papers on the subject. On the basis of this assessment, the report presents current knowledge regarding predictions of climate change (including sea-level rise) over the next century, together with an assessment of the uncertainties associated with these predictions. 14 figs., 11 tabs., 24 refs

  7. Optimization of control parameters of a hot cold controller by means of Simplex type methods

    Science.gov (United States)

    Porte, C.; Caron-Poussin, M.; Carot, S.; Couriol, C.; Moreno, M. Martin; Delacroix, A.

    1997-01-01

    This paper describes a hot/cold controller for regulating crystallization operations. The system was identified with a common method (the Broida method) and the parameters were obtained by the Ziegler-Nichols method. The paper shows that this empirical method will only allow a qualitative approach to regulation and that, in some instances, the parameters obtained are unreliable and therefore cannot be used to cancel variations between the set point and the actual values. Optimization methods were used to determine the regulation parameters and solve this identcation problem. It was found that the weighted centroid method was the best one. PMID:18924791

  8. Electroencephalographic findings in panic disorder

    Directory of Open Access Journals (Sweden)

    Marcele Regine de Carvalho

    2013-12-01

    Full Text Available Some studies have reported the importance of electroencephalography (EEG as a method for investigating abnormal parameters in psychiatric disorders. Different findings in time and frequency domain analysis with regard to central nervous system arousal during acute panic states have already been obtained. This study aimed to systematically review the EEG findings in panic disorder (PD, discuss them having a currently accepted neuroanatomical hypothesis for this pathology as a basis, and identify limitations in the selected studies. Literature search was conducted in the databases PubMed and ISI Web of Knowledge, using the keywords electroencephalography and panic disorder; 16 articles were selected. Despite the inconsistency of EEG findings in PD, the major conclusions about the absolute power of alpha and beta bands point to a decreased alpha power, while beta power tends to increase. Different asymmetry patterns were found between studies. Coherence studies pointed to a lower degree of inter-hemispheric functional connectivity at the frontal region and intra-hemispheric at the bilateral temporal region. Studies on possible related events showed changes in memory processing in PD patients when exposed to aversive stimuli. It was noticed that most findings reflect the current neurobiological hypothesis of PD, where inhibitory deficits of the prefrontal cortex related to the modulation of amygdala activity, and the subsequent activation of subcortical regions, may be responsible to trigger anxiety responses. We approached some important issues that need to be considered in further researches, especially the use of different methods for analyzing EEG signals. Keywords: Electroencephalography, panic disorder, neurobiology, brain mapping.

  9. Radiologic findings in neurofibromatosis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dai Young; Jeon, Seok Chol; Lee, Kwan Se; Yeon, Kyung Mo; Choo, Dong Woon [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1979-12-15

    Neurofibromatosis is an uncommon but certainly not a rare hereditary disorder, probably of neuralcrest origin, involving not only neuroectoderm and mesoderm but also endoderm and characterized by cafe au lait spots and cutaneous and subcutaneous tumors, with secondary mesodermal defects responsible for protean osseous abnormalities and various manifestations in other systems. This paper is a study of confirmed 143 cases of neurofibromatosis collected for past 8 years. In this analysis, special attention was given to the selected 37 cases which showed abnormal findings on radiological examinations. Overall male to female ratio was 1 : 1.3. The most frequent kind of abnormalities was vertebral kyphoscoliosis in 12 cases. Among the more pathognomonic but uncommon abnormalities to neurofibromatosis, we experienced each 2 cases of lambdoid defect, pseudoarthrosis and renovascular hypertension, and 1 cases of sphenoid bone absence.

  10. Trochanteric bursitis: radiological findings

    International Nuclear Information System (INIS)

    Revilla, T.Y.; Manjon, P.; Lozaono, C.

    1997-01-01

    To describe the radiological findings associated with trochanteric bursitis. Six patients studied by means of plain radiography (n=6), CT(n=4) and MR(n=2). The conventional radiography study was normal in two patients and disclosed bone abnormalities in four. US showed a hypoechoic or anechoic collection in all the patients. Two patients presented areas suggestive of calcification, and septa were observed in one. CT disclosed the presence of well defined, low-attenuation, unenhanced collections. MR images identified collections with a signal intensity similar to that of water. Trochanteric bursitis is a relatively common cause of hip pain, and can involve any one of a number of etiologies. US is a good imaging technique for diagnosing this pathology. (Author) 10 refs

  11. CT findings in mucopolysaccharidoses

    International Nuclear Information System (INIS)

    Tsuchida, Tomio; Nemoto, Shigeru; Fujiwara, Kazue; Hayakawa, Isao; Nihei, Kenji.

    1981-01-01

    The CT findings for four patients with mucopolysaccharidosis were analyzed using a Delta scan-25 (Ohio Nuclear). In three cases of Hunter's syndrome (MPS IIA 13-year-old male, MPS IIB 12-year-old male, and 25-year-old male), a dilatation of the cortical sulci was observed. Moderate dilatations were also seen in the basal cistern, the quadrigeminal cistern, and the ambient cistern. In one case of Hunter's syndrome, a low-density area was observed in the bilateral tharamic regions. An irregular low-density area was also seen in the white matter in some cases. PVL was not apparent in any case. Marked ventricular dilations were observed in cases with mental retardation, for example, in one case of Hurler's syndrome (8-year-old male) and one case of MPS IIA. The circulation and absorbtion of CSF in cortical snbarachnoid spaces were supposed to be moderately retarded by metrizamide CT cisternography. (author)

  12. Radiologic findings of dwarfism

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, M. S.; Oh, K. K.; Park, C. Y.; Kim, D. H. [Yonsei University, College of Medicine, Seoul (Korea, Republic of); Kim, D. H. [Yonsei Univ., Seoul (Korea, Republic of)

    1981-06-15

    The stature of human is very important factor in human-being, especially in childhood. The stature depends on various different conditions, such as familial factor, constitutional factor, chromosomal anomalies, skeletal disorders, or endocrinopathies. The early diagnosis of dwarfism is very important problem, because if appropriate treatment is delayed, the complication or sequales are more increased. The survey of familial history or patient's past history, detail check up of physical examination, radiological evaluation, and other laboratory examinations are essentially needed for the accurate diagnosis of dwarfism. Among the patients admitted to Yonsei University college of Medicine, Severance Hospital since 1963, with chief complaint of short stature or other associated diseases, an analysis of radiological findings were made for the 72 cases of chromosomal anomalies, skeletal dysplasia, and cretinism in which radiologic evaluation was available. The conclusions are as follows; 1. The cause of short stature are chromosomal anomalies (48 cases), skeletal dysplasia (14 cases) and cretinism (10 cases). 2. in chromosomal anomalies, 43 cases of mongolism and 5 cease of Turner's syndrome are noted. In mongolism, 18 cases among the 30 cases below 1 year old are distributed below the 10 percentile of height. On radiologic findings, 11 paired ribs (22/43), congenital heart disease (14/43), decreased iliac index (8/12), and associated anomalies or diseases, such as pneumonia (14 cases), C1-C2 dislocation (1 case), imperforated anus (1 case), Morgagni's hernia (1 case) and leukemia with sepsis (1 case). In Turner's syndrome, decreased bone density (5/5), positive metacarpal sign (2/5), positive carpal sign (1/5), change of knee joint (3/5), hypoplasia of (1/3), and increased carrying angle of elbows (1/3) are noted.

  13. Radiologic findings of dwarfism

    International Nuclear Information System (INIS)

    Hwang, M. S.; Oh, K. K.; Park, C. Y.; Kim, D. H.; Kim, D. H.

    1981-01-01

    The stature of human is very important factor in human-being, especially in childhood. The stature depends on various different conditions, such as familial factor, constitutional factor, chromosomal anomalies, skeletal disorders, or endocrinopathies. The early diagnosis of dwarfism is very important problem, because if appropriate treatment is delayed, the complication or sequales are more increased. The survey of familial history or patient's past history, detail check up of physical examination, radiological evaluation, and other laboratory examinations are essentially needed for the accurate diagnosis of dwarfism. Among the patients admitted to Yonsei University college of Medicine, Severance Hospital since 1963, with chief complaint of short stature or other associated diseases, an analysis of radiological findings were made for the 72 cases of chromosomal anomalies, skeletal dysplasia, and cretinism in which radiologic evaluation was available. The conclusions are as follows; 1. The cause of short stature are chromosomal anomalies (48 cases), skeletal dysplasia (14 cases) and cretinism (10 cases). 2. in chromosomal anomalies, 43 cases of mongolism and 5 cease of Turner's syndrome are noted. In mongolism, 18 cases among the 30 cases below 1 year old are distributed below the 10 percentile of height. On radiologic findings, 11 paired ribs (22/43), congenital heart disease (14/43), decreased iliac index (8/12), and associated anomalies or diseases, such as pneumonia (14 cases), C1-C2 dislocation (1 case), imperforated anus (1 case), Morgagni's hernia (1 case) and leukemia with sepsis (1 case). In Turner's syndrome, decreased bone density (5/5), positive metacarpal sign (2/5), positive carpal sign (1/5), change of knee joint (3/5), hypoplasia of (1/3), and increased carrying angle of elbows (1/3) are noted

  14. Ultrasonographic findings of retinoblastoma

    International Nuclear Information System (INIS)

    Chung, Sung Hoo; Kang, Ik Won; Park, Yang Hee; Kim, Chu Wan; Chi, Je Geun

    1982-01-01

    Retinoblastoma is the most common intraocular tumor in infants and young children which has relatively favorable prognosis with early diagnosis and adequate treatment, however, it can be lethal if the treatment is delayed or inadequate. Clinically, early diagnosis is often difficult because of minimal subjective and objective signs and symptoms, and the patients are usually too young to complain visual disturbance. When ophthalmoscopicexamination is impossible due to presence of opaue media in front of tumor mass as associated inflammatory reaction, hemorrhage, corneal opacity, retinal detachment, etc, ultrasonography is necessary for diagnosis of retinoblastoma. Authors analyzed ultrasonographic al findings with pathological correlation on 10 cases of confirmed retinoblastoma during the period of March 1981 to September1982 at the Seoul National University Hospital. In all cases, ultrasonography demonstrates intraocular masses and all of which are cystic type.Reflectivity of masses are higher than retroorbital fat tissue in 8 cases, and 7 cases show irregular internal echogenic texture. There is no correlation between reflexivity and internal echogenic texture with microscopic findings as rosette, pseudo rosette and micro cysts. Calcifications are demonstrated by ultrasonography as strong reflectiveness with posterior sonic shadowing in 9 cases and 9 of 10 cases are well correlated with calcifications in pathologic specimens. Anechoic cystic areas are shown in 9 cases, and 6 of 10 cases are well correlated with necrosis in pathologic specimen. In all cases, there is no attenuation of sound within tumor masses, and no demonstrable choroidal excavation. Associated retinal detachment is hardly identifiable in irregular contour and internal texture of cystic tumor masses

  15. Brain venous pathologies: MRI findings

    International Nuclear Information System (INIS)

    Salvatico, Rosana; Gonzalez, Alejandro; Yanez, Paulina; Romero, Carlos; Trejo, Mariano; Lambre, Hector

    2006-01-01

    Purpose: To describe MRI findings of the different brain venous pathologies. Material and Methods: Between January 2002 and March 2004, 18 patients were studied 10 males and 8 females between 6 and 63 years old; with different brain venous pathologies. In all cases brain MRI were performed including morphological sequences with and without gadolinium injection and angiographic venous sequences. Results: 10 venous occlusions were found, 6 venous angiomas, and 2 presented varices secondary to arteriovenous dural fistula. Conclusion: Brain venous pathologies can appear in many different clinical contexts, with different prognosis and treatment. In all the cases brain MRI was the best imaging study to disclose typical morphologic abnormalities. (author) [es

  16. Calcaneal tendon: imaging findings

    International Nuclear Information System (INIS)

    Montandon, Cristiano; Fonseca, Cristiano Rezio; Montandon Junior, Marcelo Eustaquio; Lobo, Leonardo Valadares; Ribeiro, Flavia Aparecida de Souza; Teixeira, Kim-Ir-Sen Santos

    2003-01-01

    We reviewed the radiological and clinical features of 23 patients with calcaneal tendon diseases, who were submitted to ultrasound or magnetic resonance imaging. The objective of this study was to characterize the lesions for a precise diagnosis of calcaneal tendon injuries. A wide range of calcaneal tendon diseases include degenerative lesions, inflammation of the peritendinous tissue such as peritendinitis and bursitis, and rupture. Imaging methods are essential in the diagnosis, treatment and follow-up of calcaneal tendon diseases. (author)

  17. Numerical simulation of the electrohydrodynamic effects on bubble rising using the SPH method

    International Nuclear Information System (INIS)

    Rahmat, A.; Tofighi, N.; Yildiz, M.

    2016-01-01

    Highlights: • An oil-water bubble rising system is simulated under the electrohydrodynamic effects using ISPH method. • The bubble aspect ratio increases by incrementing electrical capillary and Reynolds numbers, and decrementing the Bond number. • The centroid velocity increases with increments of electric capillary and Reynolds number. • Negative values of the bottom velocity are observed due to the pulling effect of the bottom boundary. • The distance between the bubble centroids decreases in vertically in-line bubble pairs. - Abstract: In this paper, numerical simulations of two dimensional bubble rising in the presence of electrohydrodynamic forces are presented. The physical properties of the bubble and the background fluid are adjusted to resemble an oil-water system. The numerical technique utilized to discretize the governing equations is the Lagrangian Incompressible Smoothed Particle Hydrodynamics (ISPH) method. A single bubble is subjected to an electric field using a leaky dielectric model under different values of Reynolds, Bond and electrical Capillary numbers. The results show that the bubble elongates in the direction of the electric field forming a prolate shape. The increase in the values of Reynolds and electrical Capillary numbers enhances prolate deformation of the bubble, but raising the Bond number reduces the prolateness of the bubble. The interaction of a bubble pair is also investigated for various configurations. If the bubbles are placed such that their centroids are vertically in-line, they tend to merge due to the initial prolate deformation. However, the bubbles do not merge for off center-oriented cases.

  18. Initial findings from a mixed-methods evaluation of computer-assisted therapy for substance misuse in prisoners: Development, implementation and clinical outcomes from the ‘Breaking Free Health & Justice’ treatment and recovery programme

    Directory of Open Access Journals (Sweden)

    Sarah Elison

    2015-08-01

    examine the processes of implementation of this novel digital health programme and the various barriers and facilitators of this, including the practicalities of providing an online treatment programme in an environment in which there are multiple, complex security requirements and considerations. Additionally, the acceptability of the BFHJ programme to prisoners who may have limited experience of using online technologies was also explored. Clinical outcomes in terms of the programmes impact on substance dependence and use were also examined. Methods: In line with the Medical Research Council (MRC guidelines around development and evaluation of complex interventions (Craig et al., 2008, a mixed-methods approach was used including a qualitative study to explore the implementation of this online treatment programme within the secure prison environment, and offender perceptions of this novel, technology-enhanced approach to substance misuse treatment. In addition, quantitative data derived from a battery of standardised psychometric assessments was used to examine clinical effectiveness of BFHJ. Results: In order to meet MoJ security requirements prior to implementation, the BFHJ programme had to be reviewed and ‘white listed’ by NOMS and their security partner XMA to ensure the programme met all security, quality and information assurance processes and standards. This was a lengthy and costly process that entailed freshly developing the programme in partnership with VC experts at NOMS to ensure the programme is ‘sterile’ i.e., there are no holes in the system or links to external websites – this comprised some aspects of the programme content and resulted in some clinical techniques requiring reworking e.g., removing Google maps from one section of the programme. Themes emerging from qualitative data around offenders experiences of BFHJ illustrate its potential for use in prison settings and also to provide, for the first time, genuine continuity of care during

  19. Findings of autopsy imaging

    International Nuclear Information System (INIS)

    Shiotani, Seiji; Saito, Tsukuru; Itoya, Saori

    2009-01-01

    Described is the outline of autopsy imaging (Ai) by CT, MRI and ultrasonography (US) as the reading of the postmortem images is becoming important for radiologist on site. The present major Ai modality is CT, where the cause of death can be identified in most cases of injuries like that by traffic accident, and of intracranial hemorrhagic lesions. It is difficult for CT alone to determine the cause due to acute heart failure, for which Ai by enhanced CT (2-min heart massage during the intravenous infusion of a contrast agent) has been introduced. CT findings in Ai are varied according to the death cause, anabiotic treatment conducted and postmortem changes. The second item includes the gastrointestinal tract dilation, rib fracture, pneumo- or hemo-thorax, bruise or rupture, and intravascular gas, and the third, the blood hypostasis, which emphasizing the shadow at the gravity-loaded portions in Ai CT. MRI signals vary dependently on the temperature and the inversion time should be shortened to suppress the cerebrospinal signal at Ai of the cold body like that stored in a refrigerator. US can detect clear, macroscopic morphological changes and the portable machine has been in practice at autopsy onsite. As sound speed depends on the temperature in water, Ai US images are obscure relative to living body due to the low temperature. Authors think the problem to identify the cause of death will be mostly solved in Japan when radiological technologists more actively participate in Ai. (K.T.)

  20. Radiographic findings in immunodeficiency

    International Nuclear Information System (INIS)

    Obregon, R.; Lynch, D.A.; Cink, T.M.; Newell, J.D.; Kirkpatrick, C.

    1991-01-01

    This paper reviews the chest radiographs and high-resolution CT (HRCT) scans in patients with immunodeficiency disorders and define the role of HRCT. Thirty-three cases were retrospectively graded according to the consensus of two radiologists. Patients with HIV seropositivity and asthma were excluded. HRCT was performed in 12 cases with standard techniques. Diagnoses included common variable hypogammaglobulinemia (n = 19), X-linked agammaglobulinemia (n = 4), chronic mucocutaneous candidiasis (n = 4), and selective immunoglobulin g deficiencies (n = 2). Chest radiographs showed bronchiectasis in 11 of 33 cases with a predominant lower lobe distribution (82%). Nodules were present in six cases and mucus plugs in four cases. HRCT showed bronchiectasis in nine of 12 cases; in five of these nine cases, bronchiectasis was not apparent on chest radiographs. Other HRCT findings included segmental air trapping (four of 12), mucus plugs (three of 12), hazy consolidation (four of 12), nodules (five of 12), and bronchiolectasis (two of 12). Therapy was altered in seven of 12 cases in which HRCT was performed. Most pertinent to clinical management were the presence of a thymoma (n = 1) and severe focal of diffuse bronchiectasis

  1. Verified scientific findings

    International Nuclear Information System (INIS)

    Bullinger, M.G.

    1982-01-01

    In this essay, the author attempts to enlighten the reader as to the meaning of the term ''verified scientific findings'' in section 13, sub-section 1, sentence 2 of the new Chemicals Control Law. The examples given here are the generally accepted regulations in regards to technology (that is sections 7a and 18b of the WHG (law on water economy), section 3, sub-section 1 of the machine- and engine protection laws) and to the status of technology (section 3, sub-section 6 of the BImSchG (Fed. law on prevention of air-borne pollution)), and to the status of science (section 5, sub-section 2 of the AMG (drug legislation). The ''status of science and technology'' as defined in sections 4 ff of the Atomic Energy Law (AtomG) and in sections 3, 4, 12, 2) of the First Radiation Protection Ordinance (1.StrlSch. VO), is also being discussed. The author defines the in his opinion ''dynamic term'' as the generally recognized result of scientific research, and the respective possibilities of practical utilization of technology. (orig.) [de

  2. Laryngotracheobronchial papillomatosis: chest CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Fortes, Helena Ribeiro; Zanetti, Glaucia; Marchiori, Edson, E-mail: edmarchiori@gmail.com [Universidade Federal do Rio de Janeiro (UFRJ), Rio de Janeiro, RJ (Brazil); Ranke, Felipe Mussi von [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Escuissato, Dante Luiz [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Clinica Medica; Araujo Neto, Cesar Augusto [Universidade Federal da Bahia (UFBA), Salvador (Brazil). Dept. de Medicina e Apoio Diagnostico; Hochhegger, Bruno [Universidade Federal de Ciencias da Saude de Porto Alegre (UFCSPA), RS (Brazil). Diagnostico por Imagem; Irion, Klaus Loureiro [Liverpool Heart and Chest Hospital NHS Foundation Trust, Liverpool (United Kingdom); Souza, Carolina Althoff [Dept. of Diagnostic Imaging, The Ottawa Hospital, University of Ottawa, Ontario (Canada)

    2017-07-15

    To evaluate the findings on chest CTs in 16 patients (8 men and 8 women) with laryngotracheobronchial papillomatosis. Methods: This was a retrospective study involving patients ranging from 2 to 72 years of age. The evaluation of the CT scans was independently performed by two observers, and discordant results were resolved by consensus. The inclusion criteria were presence of abnormalities on the CT scans, and the diagnosis was confirmed by anatomopathological examination of the papillomatous lesions. Results: The most common symptoms were hoarseness, cough, dyspnea, and recurrent respiratory infections. The major CT findings were nodular formations in the trachea, solid or cavitated nodules in the lung parenchyma, air trapping, masses, and consolidation. Nodular formations in the trachea were observed in 14 patients (87.5%). Only 2 patients had lesions in lung parenchyma without tracheal involvement. Only 1 patient had no pulmonary dissemination of the disease, showing airway involvement only. Solid and cavitated lung nodules were observed in 14 patients (87.5%) and 13 (81.2%), respectively. Masses were observed in 6 patients (37.5%); air trapping, in 3 (18.7%); consolidation in 3 (18.7%); and pleural effusion, in 1 (6.3%). Pulmonary involvement was bilateral in all cases. Conclusions: The most common tomography findings were nodular formations in the trachea, as well as solid or cavitated nodules and masses in the lung parenchyma. Malignant transformation of the lesions was observed in 5 cases. (author)

  3. Aortographic findings of Takayasu's arteritis

    International Nuclear Information System (INIS)

    Han, Man Chung; Chang, Kee Hyun; Kim, Hyo Rin; Choo, Dong Woon

    1973-01-01

    Takayasu's arteritis is a stenosing inflammatory process of unknown etiology affecting not only the aortic arch and its branches, but also the abdominal aorta, its branches and the pulmonary arteries. During the period from August 1971 to August 1973, 9 cases with Takayasu's arteries have been observed in the Seoul National University Hospital. The diagnosis was mainly based upon the aortography, which is the only practical method of delineating the extent and nature of the vascular involvement. The purpose of this paper is describe and analyze the radiographic findings, especially aortographic aspect. The results obtained are as follows: 1. The 9 cases are all female and two thirds are under 30 years of age. Headache, dizziness, absent or weak radial pulse and hypertension are the most common symptoms and signs. The laboratory data are generally unremarkable, except elevation of E.S.R. and gamma globulin fraction on electrophoresis. 2. Conventional roentgenography of the chest may be helpful but not specific in diagnosis of Takayasu's arteritis. 3. The aortographic findings are characteristic and pathognomonic in diagnosis of Takayasu's arteritis. In our cases, the most common findings are stenosis or occlusion of subclavian artery, diffuse narrowing with irregular contour of descending aorta, renal artery involvement, narrowing and aneurysmal dilatation of abdominal aorta, and multiple sites involvement. 4. Therefore, value of total aortography was stressed

  4. Hippocampal malrotation: MRI findings

    International Nuclear Information System (INIS)

    Yanez, Paulina; Martinez, Adriana; Romero, Carlos; Lopez, Miriam; Zaffaroni, Alejandra; Lopez, Adriana

    2001-01-01

    Purpose: To demonstrate the common features of hippocampus malrotation in patients with epilepsy by volumetric and high-resolution MRI. Material and methods: MRI study was performed in 5 patients (2 females and 3 males) ages ranged between 6-41 years (average: 25 years), all of them with epilepsy diagnosis. MRI was performed with a 1.5 T (GE Signa). The epilepsy protocol include sagittal T1, axial T1 and T2, coronal FLAIR, coronal T2 (high-resolution) and volumetric 3D SPGR IR 1.5 mm thick sequences. Results: The common features found in all patients were: a) Incomplete inversion and round configuration of the hippocampus; b) Unilateral affectation; c) Variable affectation of the hippocampus; d) Normal signal intensity; e) Modification of the inner structure of the hippocampus; f) Abnormal angularity of the collateral sulcus; g) Abnormal position and size of the fornix; h) Normal size of the temporal lobe; and i) Enlargement of the temporal horn with particular configuration. Conclusion: Hippocampus malrotation is a malformation that should be included in the differential diagnosis of the epilepsy patients. MRI provides accurate information for the diagnosis. (author)

  5. Finding Ernst Mayr's Plato.

    Science.gov (United States)

    Powers, Jack

    2013-12-01

    Many biologists have accepted Ernst Mayr's claim that evolutionary biology undermined an essentialist or typological view of species that had its roots in Platonic philosophy. However, Mayr has been accused of failing to support with textual evidence his attributions to Plato of these sorts of views about biology. Contemporary work in history and philosophy of biology often seems to take onboard Mayr's account of Plato's view of species. This paper seeks to provide a critical account of putative inconsistencies between an evolutionary view of species and Platonic philosophy with renewed attention to the Platonic texts in light of recent Plato scholarship; I argue that claims that Plato held an essentialist view of species inconsistent with evolutionary biology are inadequately supported by textual evidence. If Mayr's essentialist thesis fails, one might think that the intuition that Platonic philosophy is in tension with Darwinian evolution could nonetheless be accounted for by Plato's apparent privileging of a certain sort of teleological explanation, a thesis that Mayr suggests in his 1959 paper on Louis Agassiz. However, this thesis also faces difficulties. Ernst Mayr's Plato is more likely to be found in the writings of anti-evolutionary 19th century biologists like Mayr's frequent target, Agassiz, than in a cautious reading of the Platonic dialogues themselves. Interlocutors in discussions of the history of biological thought and classificatory methods in biology should be cautious in ascribing views about biology to Plato and using terms like "Platonic essentialism." Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Find a NCCAOM Certified Practitioner

    Science.gov (United States)

    ... in finding a NCCAOM Certified Diplomate. The NCCAOM Find a Practitioner Directory is a voluntary directory designed ... by the NCCAOM. If you are unable to find an individual in our registry and would like ...

  7. Primary thyroid lymphoma: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hyo-Cheol; Han, Moon Hee E-mail: hanmh@radcom.snu.ac.kr; Kim, Keon Ha; Jae, Hwan Jun; Lee, Sang Hyun; Kim, Sam Soo; Kim, Kwang Hyun; Chang, Kee-Hyun

    2003-06-01

    Introduction: To evaluate the computed tomographic (CT) findings of primary thyroid lymphoma. Methods and material: The clinicopathological data and CT images of nine patients with primary thyroid lymphoma were retrospectively reviewed. The CT appearances were classified into three types: type 1, a solitary nodule surrounded by normal thyroid tissue; type 2, multiple nodules in the thyroid, and type 3, a homogeneously enlarged both thyroid glands with a reduced attenuation with or without peripheral thin hyperattenuating thyroid tissue. Results: All patients had a rapidly enlarging thyroid mass and coexistent Hashimoto's thyroiditis. One patient showed type 1 pattern, three type 2, and five type 3. Six patients had homogeneous tumor isoattenuating to surrounding muscles. The tumors had a strong tendency to compress normal remnant thyroid and the surrounding structure without invasion. Conclusion: Primary thyroid lymphoma should be included in the differential diagnosis when old female had a homogeneous thyroidal mass isoattenuating to muscles, which does not invade surrounding structures.

  8. Hematological findings in Noonan syndrome

    Directory of Open Access Journals (Sweden)

    Bertola Débora R.

    2003-01-01

    Full Text Available OBJECTIVE: Noonan syndrome is a multiple congenital anomaly syndrome, and bleeding diathesis is considered part of the clinical findings. The purpose of this study was to determine the frequency of hemostatic abnormalities in a group of Noonan syndrome patients. METHOD: We studied 30 patients with clinical diagnosis of Noonan syndrome regarding their hemostatic status consisting of bleeding time, prothrombin time, activated partial thromboplastin time and thrombin time tests, a platelet count, and a quantitative determination of factor XI. RESULTS: An abnormal laboratory result was observed in 9 patients (30%. Although coagulation-factor deficiencies, especially factor XI deficiency, were the most common hematological findings, we also observed abnormalities of platelet count and function in our screening. CONCLUSIONS: Hemostatic abnormalities are found with some frequency in Noonan syndrome patients (30% in our sample. Therefore, we emphasize the importance of a more extensive hematological investigation in these patients, especially prior to an invasive procedure, which is required with some frequency in this disorder.

  9. MRI findings of vermian medulloblastoma

    International Nuclear Information System (INIS)

    Jung, Seung Eun; Choi, Kyu Ho; Chung, Myung Hee; Yang, Il Kwon; Shinn, Kyung Sub; Park, Young Sub

    1996-01-01

    To find characteristic MRI features of vermian medulloblastoma. Materials and methods; MRI studies and medical records were retrospectively reviewed for 12 patients with surgically proven midline medulloblastoma. The assessment concerned appearance of the mass in relation to surrounding structures: MR signal intensity; the enhancement pattern; the mass's location and size: presence of a cystic/necrotic area, calcification, or vascular void: extension through the foramen Luschka: degree of hydrocephalus: and presence of tonsillar herniation. The midline medulloblastoma commonly showed roundish moon-surface appearance, especially on the axial T2-weighted images. All tumors showed heterogeneous signal intensities mainly due to intratumoral cystic/necrotic or hemorrhagic changes. The tumors were commonly located at mid-and/or inferior vermis. Occasionally the tumors extended through the foramen Luschka, and caused obstructive hydrocephalus of moderate to severe degree. Post-contrast study showed heterogeneous, dense contrast enhancement in the majority of patients. The MR finding of the moon-surface appearance formed by both the mass and the intratumoral cystic/necrotic change as seen on axial T2-weighted images could be helpful in the diagnosis of vermian medulloblastoma

  10. Large-scale structure of the Taurus molecular complex. II. Analysis of velocity fluctuations and turbulence. III. Methods for turbulence

    International Nuclear Information System (INIS)

    Kleiner, S.C.; Dickman, R.L.

    1985-01-01

    The velocity autocorrelation function (ACF) of observed spectral line centroid fluctuations is noted to effectively reproduce the actual ACF of turbulent gas motions within an interstellar cloud, thereby furnishing a framework for the study of the large scale velocity structure of the Taurus dark cloud complex traced by the present C-13O J = 1-0 observations of this region. The results obtained are discussed in the context of recent suggestions that widely observed correlations between molecular cloud widths and cloud sizes indicate the presence of a continuum of turbulent motions within the dense interstellar medium. Attention is then given to a method for the quantitative study of these turbulent motions, involving the mapping of a source in an optically thin spectral line and studying the spatial correlation properties of the resulting velocity centroid map. 61 references

  11. Reconstruction of brachytherapy seed positions and orientations from cone-beam CT x-ray projections via a novel iterative forward projection matching method

    Energy Technology Data Exchange (ETDEWEB)

    Pokhrel, Damodar; Murphy, Martin J.; Todor, Dorin A.; Weiss, Elisabeth; Williamson, Jeffrey F. [Department of Radiation Oncology, School of Medicine, Virginia Commonwealth University, Richmond, Virginia 23298 (United States)

    2011-01-15

    Purpose: To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. Methods: The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. Results: In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 deg., respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78{+-}0.57) mm or less. The {theta} and {phi} angle errors were found to be (5.7{+-}4.9) deg. and (6.0{+-}4.1) deg., respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 deg. compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. Conclusions: This work describes a novel, accurate, and completely automatic method for reconstructing

  12. MR findings of polymyositis / dermatomyositis

    International Nuclear Information System (INIS)

    Lee, Hak Soo; Joo, Kyung Bin; Moon, Won Jin; Lee, Tae Hee; Park, Ki Ho; Park, Dong Woo; Hahm, Chang Kok

    1998-01-01

    The purpose of this study was to evaluate the MR findings and useful sequences in Polymyositis/ Dermatomyositis, and to correlate MR findings with disease activity. Materials and Methods: The study included nine clinically proven cases of Polymyositis/Dermatomyositis, eight involving the thigh and one, the shoulder (2 cases, 1 follow-up). The contrast between affected and normal muscles and difference in signal intensity ratio in the muscle groups were retrospectively evaluated on Gd-enhanced T1WI and T2WI. We also evaluated the magnitude of involvement of muscle groups, fatty replacement of muscle and change of subcutaneous fat layer, and correlated signal intensity ratio with serum level of muscle enzymes. Differences in signal intensity ratio and the frequency of chemical shift artifact were evaluated on T2WI as active and inactive groups classified according to clinical findings, and the chemical shift artifact was correlated with the finding of Gd-enhanced T1WI. Except in the case of one shoulder, statistical analysis was assessed by the Anova test and-test. Results: On Gd-enhanced T1WI and T2WI contrast was 0.54 and 0.82, respectively and p value was 0.02. With regard to difference in signal intensity ratios of muscle groups, as seen on Gd-enhanced T1WI and T2WI, p valves were 0.07 and < 0.01, respectively. Muscle involvement was thus clearly visualized on T2WI. The order of frequency of involved muscle groups was vastus muscles, gluteus maximus, sartorius muscles, adductor muscles, gracilis muscle, and hamstring muscles. Fatty replacement and subcutaneous fatty change were visualized in five cases and one, respectively. The correlation coefficient between the signal intensity seen on T2WI and muscle enzymes was 0.59 (CPK) and 0.52 (LDH). The chemical-shift artifact was detected in both clinical groups (four active two inactive) and corresponded to one case of muscle involvement and five of perimuscular edema, as seen on Gd-enhanced T1WI. Conclusion: T2WI is

  13. Major KEEP Findings, 1971 - 1975.

    Science.gov (United States)

    Kamehameha Schools, Honolulu, HI. Kamehameha Early Education Project.

    This report lists the 34 major research findings from the Kamehameha Early Education Program (KEEP) for the years 1971-1975. Each finding is accompanied by a listing of KEEP technical reports and working papers which contain information relevant to that finding. Included among areas covered in the findings are: (1) student motivation, (2) teacher…

  14. Fast, rugged and sensitive ultra high pressure liquid chromatography tandem mass spectrometry method for analysis of cyanotoxins in raw water and drinking water--First findings of anatoxins, cylindrospermopsins and microcystin variants in Swedish source waters and infiltration ponds.

    Science.gov (United States)

    Pekar, Heidi; Westerberg, Erik; Bruno, Oscar; Lääne, Ants; Persson, Kenneth M; Sundström, L Fredrik; Thim, Anna-Maria

    2016-01-15

    Freshwater blooms of cyanobacteria (blue-green algae) in source waters are generally composed of several different strains with the capability to produce a variety of toxins. The major exposure routes for humans are direct contact with recreational waters and ingestion of drinking water not efficiently treated. The ultra high pressure liquid chromatography tandem mass spectrometry based analytical method presented here allows simultaneous analysis of 22 cyanotoxins from different toxin groups, including anatoxins, cylindrospermopsins, nodularin and microcystins in raw water and drinking water. The use of reference standards enables correct identification of toxins as well as precision of the quantification and due to matrix effects, recovery correction is required. The multi-toxin group method presented here, does not compromise sensitivity, despite the large number of analytes. The limit of quantification was set to 0.1 μg/L for 75% of the cyanotoxins in drinking water and 0.5 μg/L for all cyanotoxins in raw water, which is compliant with the WHO guidance value for microcystin-LR. The matrix effects experienced during analysis were reasonable for most analytes, considering the large volume injected into the mass spectrometer. The time of analysis, including lysing of cell bound toxins, is less than three hours. Furthermore, the method was tested in Swedish source waters and infiltration ponds resulting in evidence of presence of anatoxin, homo-anatoxin, cylindrospermopsin and several variants of microcystins for the first time in Sweden, proving its usefulness. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

  15. A method to determine the detector locations of the cone-beam projection of the balls’ centers

    International Nuclear Information System (INIS)

    Deng, Lin; Xi, Xiaoqi; Li, Lei; Han, Yu; Yan, Bin

    2015-01-01

    In geometric calibration of cone-beam computed tomography (CBCT), sphere-like objects such as balls are widely imaged, the positioning information of which is obtained to determine the unknown geometric parameters. In this process, the accuracy of the detector location of CB projection of the center of the ball, which we call the center projection, is very important, since geometric calibration is sensitive to errors in the positioning information. Currently in almost all the geometric calibration using balls, the center projection is invariably estimated by the center of the support of the projection or the centroid of the intensity values inside the support approximately. Clackdoyle’s work indicates that the center projection is not always at the center of the support or the centroid of the intensity values inside, and has given a quantitative analysis of the maximum errors in evaluating the center projection by the centroid. In this paper, an exact method is proposed to calculate the center projection, utilizing both the detector location of the ellipse center and the two axis lengths of the ellipse. Numerical simulation results have demonstrated the precision and the robustness of the proposed method. Finally there are some comments on this work with non-uniform density balls, as well as the effect by the error occurred in the evaluation for the location of the orthogonal projection of the cone vertex onto the detector. (paper)

  16. Findings

    Science.gov (United States)

    ... Response Chemistry and Biochemistry Enzymes, Molecular Probes, Metabolic Engineering, Glycobiology, Synthesis, Natural Products, Chemical Reactions Computers in Biology Bioinformatics, Modeling, Systems Biology, Data ...

  17. The Brain and Spinal Injury Center score: a novel, simple, and reproducible method for assessing the severity of acute cervical spinal cord injury with axial T2-weighted MRI findings.

    Science.gov (United States)

    Talbott, Jason F; Whetstone, William D; Readdy, William J; Ferguson, Adam R; Bresnahan, Jacqueline C; Saigal, Rajiv; Hawryluk, Gregory W J; Beattie, Michael S; Mabray, Marc C; Pan, Jonathan Z; Manley, Geoffrey T; Dhall, Sanjay S

    2015-10-01

    Previous studies that have evaluated the prognostic value of abnormal changes in signals on T2-weighted MRI scans of an injured spinal cord have focused on the longitudinal extent of this signal abnormality in the sagittal plane. Although the transverse extent of injury and the degree of spared spinal cord white matter have been shown to be important for predicting outcomes in preclinical animal models of spinal cord injury (SCI), surprisingly little is known about the prognostic value of altered T2 relaxivity in humans in the axial plane. The authors undertook a retrospective chart review of 60 patients who met the inclusion criteria of this study and presented to the authors' Level I trauma center with an acute blunt traumatic cervical SCI. Within 48 hours of admission, all patients underwent MRI examination, which included axial and sagittal T2 images. Neurological symptoms, evaluated with the grades according to the American Spinal Injury Association (ASIA) Impairment Scale (AIS), at the time of admission and at hospital discharge were correlated with MRI findings. Five distinct patterns of intramedullary spinal cord T2 signal abnormality were defined in the axial plane at the injury epicenter. These patterns were assigned ordinal values ranging from 0 to 4, referred to as the Brain and Spinal Injury Center (BASIC) scores, which encompassed the spectrum of SCI severity. The BASIC score strongly correlated with neurological symptoms at the time of both hospital admission and discharge. It also distinguished patients initially presenting with complete injury who improved by at least one AIS grade by the time of discharge from those whose injury did not improve. The authors' proposed score was rapid to apply and showed excellent interrater reliability. The authors describe a novel 5-point ordinal MRI score for classifying acute SCIs on the basis of axial T2-weighted imaging. The proposed BASIC score stratifies the SCIs according to the extent of transverse T2

  18. "Because if we talk about health issues first, it is easier to talk about human trafficking"; findings from a mixed methods study on health needs and service provision among migrant and trafficked fishermen in the Mekong.

    Science.gov (United States)

    Pocock, Nicola S; Tadee, Reena; Tharawan, Kanokwan; Rongrongmuang, Wansiri; Dickson, Brett; Suos, Soksreymom; Kiss, Ligia; Zimmerman, Cathy

    2018-05-09

    Human trafficking in the fishing industry or "sea slavery" in the Greater Mekong Subregion is reported to involve some of the most extreme forms of exploitation and abuse. A largely unregulated sector, commercial fishing boats operate in international waters far from shore and outside of national jurisdiction, where workers are commonly subjected to life-threatening risks. Yet, research on the health needs of trafficked fishermen is sparse. This paper describes abuses, occupational hazards, physical and mental health and post-trafficking well-being among a systematic consecutive sample of 275 trafficked fishermen using post-trafficking services in Thailand and Cambodia. These findings are complemented by qualitative interview data collected with 20 key informants working with fishermen or on issues related to their welfare in Thailand. Men and boys trafficked for fishing (aged 12-55) were mainly from Cambodia (n = 217) and Myanmar (n = 55). Common physical health problems included dizzy spells (30.2%), exhaustion (29.5%), headaches (28.4%) and memory problems (24.0%). Nearly one-third (29.1%) reported pain in three or more areas of their body and one-quarter (26.9%) reported being in "poor" health. Physical health symptoms were strongly associated with: severe violence; injuries; engagement in long-haul fishing; immigration detention or symptoms of mental health disorders. Survivors were exposed to multiple work hazards and were perceived as disposable when disabled by illness or injuries. Employers struggled to apply internationally recommended Personal Protective Equipment (PPE) practices in Thailand. Non-governmental organizations (NGOs) encountered challenges when trying to obtain healthcare for uninsured fishermen. Challenges included fee payment, service provision in native languages and officials siding with employers in disputes over treatment costs and accident compensation. Survivors' post-trafficking concerns included: money problems (75

  19. Asking about Sex in General Health Surveys: Comparing the Methods and Findings of the 2010 Health Survey for England with Those of the Third National Survey of Sexual Attitudes and Lifestyles.

    Directory of Open Access Journals (Sweden)

    Philip Prah

    Full Text Available Including questions about sexual health in the annual Health Survey for England (HSE provides opportunities for regular measurement of key public health indicators, augmenting Britain's decennial National Survey of Sexual Attitudes and Lifestyles (Natsal. However, contextual and methodological differences may limit comparability of the findings. We examine the extent of these differences between HSE 2010 and Natsal-3 and investigate their impact on parameter estimates.Complex survey analyses of data from men and women in the 2010 HSE (n = 2,782 men and 3,588 women and Natsal-3 undertaken 2010-2012 (n = 4,882 men and 6,869 women aged 16-69y and resident in England, both using probability sampling, compared their characteristics, the amount of non-response to, and estimates from, sexual health questions. Both surveys used self-completion for the sexual behaviour questions but this was via computer-assisted self-interview (CASI in Natsal-3 and a pen-and-paper questionnaire in HSE 2010.The surveys achieved similar response rates, both around 60%, and demographic profiles largely consistent with the census, although HSE participants tended to be less educated, and reported worse general health, than Natsal-3 participants. Item non-response to the sexual health questions was typically higher in HSE 2010 (range: 9-18% relative to Natsal-3 (all <5%. Prevalence estimates for sexual risk behaviours and STI-related indicators were generally slightly lower in HSE 2010 than Natsal-3.While a relatively high response to sexual health questions in HSE 2010 demonstrates the feasibility of asking such questions in a general health survey, differences with Natsal-3 do exist. These are likely due to the HSE's context as a general health survey and methodological limitations such as its current use of pen-and-paper questionnaires. Methodological developments to the HSE should be considered so that its data can be interpreted in combination with those from dedicated

  20. A Local Weighted Nearest Neighbor Algorithm and a Weighted and Constrained Least-Squared Method for Mixed Odor Analysis by Electronic Nose Systems

    Directory of Open Access Journals (Sweden)

    Jyuo-Min Shyu

    2010-11-01

    Full Text Available A great deal of work has been done to develop techniques for odor analysis by electronic nose systems. These analyses mostly focus on identifying a particular odor by comparing with a known odor dataset. However, in many situations, it would be more practical if each individual odorant could be determined directly. This paper proposes two methods for such odor components analysis for electronic nose systems. First, a K-nearest neighbor (KNN-based local weighted nearest neighbor (LWNN algorithm is proposed to determine the components of an odor. According to the component analysis, the odor training data is firstly categorized into several groups, each of which is represented by its centroid. The examined odor is then classified as the class of the nearest centroid. The distance between the examined odor and the centroid is calculated based on a weighting scheme, which captures the local structure of each predefined group. To further determine the concentration of each component, odor models are built by regressions. Then, a weighted and constrained least-squares (WCLS method is proposed to estimate the component concentrations. Experiments were carried out to assess the effectiveness of the proposed methods. The LWNN algorithm is able to classify mixed odors with different mixing ratios, while the WCLS method can provide good estimates on component concentrations.

  1. Chronic eosinophilic pneumonia: CT findings

    International Nuclear Information System (INIS)

    Gutierrez, Haydee; Beccar Varela, Lucia; De Felippi, Maria S.

    2002-01-01

    Objective: To assess the usefulness of computerized tomography (CT) in the diagnosis of chronic eosinophilic pneumonia. Material and Methods: A double helical CT was performed in 6 patients referred to our center because of a chest X-ray with pulmonary infiltrates. Clinical presentation was cough, fever and eosinophilia in peripheral blood. Patients' age ranged from 25 to 55 years; 4 were women and 2 were men, one of the latter had a history of bronchial asthma. All patients received treatment with corticosteroids, with remission of the clinical and radiological parameters. Three patients underwent a control CT. Results: Findings consisted in focal parenchymal alterations, with areas of pulmonary consolidation and areas of 'ground glass' appearance; both patterns coexisted in certain areas. In 3 cases the lesions extended from the apices to the pulmonary bases, with predominance of the upper and middle fields. In 1 patient, there was frank predominance in the left hemi thorax. In another patient, who had a history of asthma, there were signs of pulmonary hyperinflation, with diffuse thickening of the bronchial walls, added to the previously mentioned findings, which involved the entire lung. In the mediastinum, 1 patient had lymph nodes larger than 1 cm, 3 had lymph nodes that were not enlarged but were more numerous than usual, and in the remaining patients no lymph nodes were found. The control CT's showed almost total resolution of the pulmonary infiltrates. Conclusion: The combination of eosinophilia and characteristic pulmonary infiltrates with a likely clinical presentation, associated with an optimal response to treatment with corticosteroids allows to make a reliable diagnosis and avoids the need for a pulmonary biopsy. (author)

  2. MRI findings of uveal metastases

    International Nuclear Information System (INIS)

    Chen Qinghua; Wang Zhenchang; Xian Junfang; Yan Fei; He Liyan; Tian Qichang; Yang Bentao; Liu Zhonglin

    2007-01-01

    Objective: To evaluate MR imaging findings of uveal metastases. Methods: MR imaging findings of 20 cases with uveal metastases comfirmed by pathology or follow-up were retrospectively analyzed. MR imaging was performed in 20 patients, of which postcontrast T 1 -weighted imaging was performed in 19 patients including dynamic contrast enhancement scanning in four cases. Results: Metastatic tumor was found in the iris and ciliary body in two cases, and in choroid in 18 cases. The tumor demonstrated slightly hypointense signal on T 1 -weighted imaging and isointense signal on T 2 -weighted imaging in two cases, isointense signal on T 1 -weighted imaging and isointense signal on T 2 -weighted imaging in nine cases, isointense signal on T 1 -weighted imaging and slightly hyperintense signal on T 2 -weighted imaging in three cases, isointense signal on T 1 -weighted imaging and slightly hypointense signal on T 2 - weighted imaging in three cases, slightly hyperintense signal on T 1 -weighted imaging and slightly hypointense signal on T 2 -weighted imaging in two cases, and slightly hyperintense signal on T 1 -weighted imaging and slightly hyperintense signal on T 2 -weighted imaging in one case. The tumor appeared as mild thickness of the wall of the globe in eight cases, a crescent mass in three cases, a fusiform mass in seven cases, and a nodule in two cases. Nineteen patients showed moderate or marked enhancement on postcontrast T 1 -weighted imaging. The time-intensity curve of dynamic contrast enhancement in four patients suggested a rapid enhancement and slow washout pattern. Retinal detachment was observed in 11 patients and abnormal signal intensity within the vitreous body was seen in two cases. Conclusion: MRI can display the location, shape, signal characteristics, and enhancement pattern of uveal metastases, contributing to diagnosis and differential diagnosis. (authors)

  3. Reconstruction of brachytherapy seed positions and orientations from cone-beam CT x-ray projections via a novel iterative forward projection matching method.

    Science.gov (United States)

    Pokhrel, Damodar; Murphy, Martin J; Todor, Dorin A; Weiss, Elisabeth; Williamson, Jeffrey F

    2011-01-01

    To generalize and experimentally validate a novel algorithm for reconstructing the 3D pose (position and orientation) of implanted brachytherapy seeds from a set of a few measured 2D cone-beam CT (CBCT) x-ray projections. The iterative forward projection matching (IFPM) algorithm was generalized to reconstruct the 3D pose, as well as the centroid, of brachytherapy seeds from three to ten measured 2D projections. The gIFPM algorithm finds the set of seed poses that minimizes the sum-of-squared-difference of the pixel-by-pixel intensities between computed and measured autosegmented radiographic projections of the implant. Numerical simulations of clinically realistic brachytherapy seed configurations were performed to demonstrate the proof of principle. An in-house machined brachytherapy phantom, which supports precise specification of seed position and orientation at known values for simulated implant geometries, was used to experimentally validate this algorithm. The phantom was scanned on an ACUITY CBCT digital simulator over a full 660 sinogram projections. Three to ten x-ray images were selected from the full set of CBCT sinogram projections and postprocessed to create binary seed-only images. In the numerical simulations, seed reconstruction position and orientation errors were approximately 0.6 mm and 5 degrees, respectively. The physical phantom measurements demonstrated an absolute positional accuracy of (0.78 +/- 0.57) mm or less. The theta and phi angle errors were found to be (5.7 +/- 4.9) degrees and (6.0 +/- 4.1) degrees, respectively, or less when using three projections; with six projections, results were slightly better. The mean registration error was better than 1 mm/6 degrees compared to the measured seed projections. Each test trial converged in 10-20 iterations with computation time of 12-18 min/iteration on a 1 GHz processor. This work describes a novel, accurate, and completely automatic method for reconstructing seed orientations, as well as

  4. Can the Onset of Type 2 Diabetes Be Delayed by a Group-Based Lifestyle Intervention in Women with Prediabetes following Gestational Diabetes Mellitus (GDM? Findings from a Randomized Control Mixed Methods Trial

    Directory of Open Access Journals (Sweden)

    Angela O’Dea

    2015-01-01

    Full Text Available Objective. To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM. Design. A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n=24 or wait control (n=26 and postintervention qualitative interviews with participants. Main Outcome Measures. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG from study entry to one-year follow-up. Results. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Conclusions. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

  5. Can the Onset of Type 2 Diabetes Be Delayed by a Group-Based Lifestyle Intervention in Women with Prediabetes following Gestational Diabetes Mellitus (GDM)? Findings from a Randomized Control Mixed Methods Trial.

    Science.gov (United States)

    O'Dea, Angela; Tierney, Marie; McGuire, Brian E; Newell, John; Glynn, Liam G; Gibson, Irene; Noctor, Eoin; Danyliv, Andrii; Connolly, Susan B; Dunne, Fidelma P

    2015-01-01

    To evaluate a 12-week group-based lifestyle intervention programme for women with prediabetes following gestational diabetes (GDM). A two-group, mixed methods randomized controlled trial in which 50 women with a history of GDM and abnormal glucose tolerance postpartum were randomly assigned to intervention (n = 24) or wait control (n = 26) and postintervention qualitative interviews with participants. Modifiable biochemical, anthropometric, behavioural, and psychosocial risk factors associated with the development of type 2 diabetes. The primary outcome variable was the change in fasting plasma glucose (FPG) from study entry to one-year follow-up. At one-year follow-up, the intervention group showed significant improvements over the wait control group on stress, diet self-efficacy, and quality of life. There was no evidence of an effect of the intervention on measures of biochemistry or anthropometry; the effect on one health behaviour, diet adherence, was close to significance. Prevention programmes must tackle the barriers to participation faced by this population; home-based interventions should be investigated. Strategies for promoting long-term health self-management need to be developed and tested.

  6. Going Local to Find Help

    Science.gov (United States)

    ... Cover Story: Traumatic Brain Injury Going Local to Find Help Past Issues / Fall 2008 Table of Contents ... phone numbers, maps and directions, such as To Find Out More: Visit www.ninds.nih.gov/Disorders/ ...

  7. Find an Allergist/Immunologist

    Science.gov (United States)

    ... Search Search AAAAI Breadcrumb navigation Home ▸ Members Only Find an Allergist / Immunologist "); } $(document).ready( function () { refreshFields(); }); Welcome to AAAAI Find an Allergist. The search options below can be ...

  8. Analysis of k-means clustering approach on the breast cancer Wisconsin dataset.

    Science.gov (United States)

    Dubey, Ashutosh Kumar; Gupta, Umesh; Jain, Sonal

    2016-11-01

    Breast cancer is one of the most common cancers found worldwide and most frequently found in women. An early detection of breast cancer provides the possibility of its cure; therefore, a large number of studies are currently going on to identify methods that can detect breast cancer in its early stages. This study was aimed to find the effects of k-means clustering algorithm with different computation measures like centroid, distance, split method, epoch, attribute, and iteration and to carefully consider and identify the combination of measures that has potential of highly accurate clustering accuracy. K-means algorithm was used to evaluate the impact of clustering using centroid initialization, distance measures, and split methods. The experiments were performed using breast cancer Wisconsin (BCW) diagnostic dataset. Foggy and random centroids were used for the centroid initialization. In foggy centroid, based on random values, the first centroid was calculated. For random centroid, the initial centroid was considered as (0, 0). The results were obtained by employing k-means algorithm and are discussed with different cases considering variable parameters. The calculations were based on the centroid (foggy/random), distance (Euclidean/Manhattan/Pearson), split (simple/variance), threshold (constant epoch/same centroid), attribute (2-9), and iteration (4-10). Approximately, 92 % average positive prediction accuracy was obtained with this approach. Better results were found for the same centroid and the highest variance. The results achieved using Euclidean and Manhattan were better than the Pearson correlation. The findings of this work provided extensive understanding of the computational parameters that can be used with k-means. The results indicated that k-means has a potential to classify BCW dataset.

  9. Find an Ob-Gyn

    Science.gov (United States)

    ... Management Education & Events Advocacy For Patients About ACOG Find an Ob-Gyn Home About ACOG Find an Ob-Gyn Page Navigation ▼ About Us ACOG ... Districts ACOG Sections Careers at ACOG Contact Us Find an Ob-Gyn Search by State Search by ...

  10. A new method for ordering triangular fuzzy numbers

    Directory of Open Access Journals (Sweden)

    S.H. Nasseri

    2010-09-01

    Full Text Available Ranking fuzzy numbers plays a very important role in linguistic decision making and other fuzzy application systems. In spite of many ranking methods, no one can rank fuzzy numbers with human intuition consistently in all cases. Shortcoming are found in some of the convenient methods for ranking triangular fuzzy numbers such as the coefficient of variation (CV index, distance between fuzzy sets, centroid point and original point, and also weighted mean value. In this paper, we introduce a new method for ranking triangular fuzzy number to overcome the shortcomings of the previous techniques. Finally, we compare our method with some convenient methods for ranking fuzzy numbers to illustrate the advantage our method.

  11. MR findings in intralabyrinthine schwannomas

    Energy Technology Data Exchange (ETDEWEB)

    Montague, Mary-Louise; Kishore, Ameet; Hadley, Donald M.; O' Reilly, Brian

    2002-05-01

    AIM: Intralabyrinthine schwannomas (ILS) are rare benign tumours. They are not always recognized on routine magnetic resonance imaging (MRI). We aimed to study the clinical presentation and MRI findings in our patients with ILS. MATERIALS AND METHODS: Retrospective analysis of patients with vestibular schwannomas treated at this center. RESULTS: Of 144 vestibular schwannomas studied at this centre, three patients had an ILS. The most common presenting symptoms were unilateral hearing loss, tinnitus and vertigo. Two patients demonstrated a progressive sensorineural hearing loss (SNHL). The third patient had a severe SNHL at presentation. MRI enhanced with contrast medium was positive in the two patients with progressive SNHL and negative in the patient with the severe SNHL. CONCLUSION: This series demonstrates the ability of MRI to identify schwannomas filling the labyrinth, and also its inability to identify extremely small ILS. It underlines the importance of sending the cristae of patients undergoing labyrinthectomy for presumed Meniere's disease for histological examination. Montague, M.-L. et al. (2002)

  12. MR findings in intralabyrinthine schwannomas

    International Nuclear Information System (INIS)

    Montague, Mary-Louise; Kishore, Ameet; Hadley, Donald M.; O'Reilly, Brian

    2002-01-01

    AIM: Intralabyrinthine schwannomas (ILS) are rare benign tumours. They are not always recognized on routine magnetic resonance imaging (MRI). We aimed to study the clinical presentation and MRI findings in our patients with ILS. MATERIALS AND METHODS: Retrospective analysis of patients with vestibular schwannomas treated at this center. RESULTS: Of 144 vestibular schwannomas studied at this centre, three patients had an ILS. The most common presenting symptoms were unilateral hearing loss, tinnitus and vertigo. Two patients demonstrated a progressive sensorineural hearing loss (SNHL). The third patient had a severe SNHL at presentation. MRI enhanced with contrast medium was positive in the two patients with progressive SNHL and negative in the patient with the severe SNHL. CONCLUSION: This series demonstrates the ability of MRI to identify schwannomas filling the labyrinth, and also its inability to identify extremely small ILS. It underlines the importance of sending the cristae of patients undergoing labyrinthectomy for presumed Meniere's disease for histological examination. Montague, M.-L. et al. (2002)

  13. Radiologic findings of osteochondritis dissecans

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jae Seung; Choi, Choong Gon; Kang, Heung Sik; Lee, Seon Kyu; Kim, Chu Wan [Seoul National University College of Medicine, Seoul (Korea, Republic of)

    1993-05-15

    To evaluate the radiographic characteristics of osteochondritis dissecans (OCD) and useful parameter for predicting mechanical stability, we retrospectively analysed 26 plain radiographic examinations and seven MR imagings in 28 cases of OCD in 24 patients. Typical radiologic findings were osteochondral defect with sclerotic rim of variable thickness and osteochondral fragment. Sites of osteochondral defect were medial (35.9%) or lateral (32%) femoral chondyle and medial (7.1%) or lateral (25%) side of talar dome. Sclerotic rim was seen in 24 cases (85%) and osteochondral fragments including nine loose bodies were seen in 21 cases (75%). The size of osteochondral defect with unstable fragment (average 2.05 cm) and loose body (2.04 cm) in the knee joint were similar to, but statistically larger than that with stable fragment (1.35 cm). All osteochondral defects were well visualized on MR images. Abnormalities of articular cartilage and effusion in the interface between the parent bone and fragment were seen in five cases of which there were confirmed three unstable cases arthroscopically. We concluded that size of defect may be a good parameter for predicting mechanical stability and MRI may be useful in the diagnosis of OCD and determining the methods of treatment.

  14. MR findings in intralabyrinthine schwannomas

    Energy Technology Data Exchange (ETDEWEB)

    Montague, Mary-Louise; Kishore, Ameet; Hadley, Donald M; O' Reilly, Brian

    2002-05-01

    AIM: Intralabyrinthine schwannomas (ILS) are rare benign tumours. They are not always recognized on routine magnetic resonance imaging (MRI). We aimed to study the clinical presentation and MRI findings in our patients with ILS. MATERIALS AND METHODS: Retrospective analysis of patients with vestibular schwannomas treated at this center. RESULTS: Of 144 vestibular schwannomas studied at this centre, three patients had an ILS. The most common presenting symptoms were unilateral hearing loss, tinnitus and vertigo. Two patients demonstrated a progressive sensorineural hearing loss (SNHL). The third patient had a severe SNHL at presentation. MRI enhanced with contrast medium was positive in the two patients with progressive SNHL and negative in the patient with the severe SNHL. CONCLUSION: This series demonstrates the ability of MRI to identify schwannomas filling the labyrinth, and also its inability to identify extremely small ILS. It underlines the importance of sending the cristae of patients undergoing labyrinthectomy for presumed Meniere's disease for histological examination. Montague, M.-L. et al. (2002)

  15. Gastric traumatic injuries: CT findings

    International Nuclear Information System (INIS)

    Lassandro, Francesco; Romano, Stefania; Rossi, Giovanni; Muto, Roberto; Cappabianca, Salvatore; Grassi, Roberto

    2006-01-01

    Objective: Gastric blunt traumatic injuries are uncommon and their radiological appearance has been infrequently reported in medical literature. These injuries are difficult to diagnose preoperatively, though they require immediate recognition to minimize their otherwise high mortality and morbidity. The aim of our study is to describe the radiological appearance of blunt gastric traumatic injuries. Materials and methods: Retrospective evaluation of a 25 patients series observed between January 1997 and May 2005. Results: We observed rupture of the stomach in 20% of cases, in 44% of cases a partial lesion of the stomach, in one case a necrotic post-traumatic volvulus, five patients (20%) had benign portal pneumatosis, in three patients the stomach was secondarily involved because of a diaphragmatic hernia. The fundus resulted to be the most frequently damaged part of the stomach (80%). Conclusions: Blunt traumatic injuries need a careful and systematic approach given their economical and social relevance. For these reasons uncommon lesions require attention and may be important to search for specific findings of gastric lesions

  16. Gastric traumatic injuries: CT findings

    Energy Technology Data Exchange (ETDEWEB)

    Lassandro, Francesco [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy)]. E-mail: francesco.lassandro@fastwebnet.it; Romano, Stefania [Department of Diagnostic Imaging, ' A. Cardarelli' Hospital, I-80131 Naples (Italy); Rossi, Giovanni [Department of Radiology, V. Monaldi Hospital, Naples (Italy); Muto, Roberto [Department of Radiology, V. Monaldi Hospital, Naples (Italy); Cappabianca, Salvatore [Magrassi-Lanzara Department, Institute of Radiology, Second University of Naples (Italy); Grassi, Roberto [Magrassi-Lanzara Department, Institute of Radiology, Second University of Naples (Italy)

    2006-09-15

    Objective: Gastric blunt traumatic injuries are uncommon and their radiological appearance has been infrequently reported in medical literature. These injuries are difficult to diagnose preoperatively, though they require immediate recognition to minimize their otherwise high mortality and morbidity. The aim of our study is to describe the radiological appearance of blunt gastric traumatic injuries. Materials and methods: Retrospective evaluation of a 25 patients series observed between January 1997 and May 2005. Results: We observed rupture of the stomach in 20% of cases, in 44% of cases a partial lesion of the stomach, in one case a necrotic post-traumatic volvulus, five patients (20%) had benign portal pneumatosis, in three patients the stomach was secondarily involved because of a diaphragmatic hernia. The fundus resulted to be the most frequently damaged part of the stomach (80%). Conclusions: Blunt traumatic injuries need a careful and systematic approach given their economical and social relevance. For these reasons uncommon lesions require attention and may be important to search for specific findings of gastric lesions.

  17. Incidental findings in musculoskeletal radiology

    International Nuclear Information System (INIS)

    Wuennemann, F.; Rehnitz, C.; Weber, M.A.

    2017-01-01

    Increasing numbers of conventional X-rays, computed tomography and magnetic resonance imaging in the inpatient, outpatient and scientific routine leads to an increasing number of incidental findings. The correct interpretation of these incidental findings with respect to the relevance and the evaluation concerning further work-up is an important task of radiologists. Description of common incidental findings in musculoskeletal imaging and their clinical classification. A PubMed literature search was performed using the following terms: incidental findings, population-based imaging, musculoskeletal imaging, non-ossifying fibroma, enchondroma, osteodystrophia deformans, chondrosarcoma, fibrous dysplasia, simple bone cyst, unicameral bone cyst, solitary bone cyst, aneurysmal bone cyst, vertebral hemangioma, bone island, osteopoikilosis, Tarlov cyst and diffuse idiopathic skeletal hyperostosis (DISH). Incidental findings are observed in up to 40% of imaging procedures. In up to 6% these incidental findings involve the skeletal system. Common incidental findings are discussed and their clinical relevance is explained. (orig.) [de

  18. TOWARDS FINDING A NEW KERNELIZED FUZZY C-MEANS CLUSTERING ALGORITHM

    Directory of Open Access Journals (Sweden)

    Samarjit Das

    2014-04-01

    Full Text Available Kernelized Fuzzy C-Means clustering technique is an attempt to improve the performance of the conventional Fuzzy C-Means clustering technique. Recently this technique where a kernel-induced distance function is used as a similarity measure instead of a Euclidean distance which is used in the conventional Fuzzy C-Means clustering technique, has earned popularity among research community. Like the conventional Fuzzy C-Means clustering technique this technique also suffers from inconsistency in its performance due to the fact that here also the initial centroids are obtained based on the randomly initialized membership values of the objects. Our present work proposes a new method where we have applied the Subtractive clustering technique of Chiu as a preprocessor to Kernelized Fuzzy CMeans clustering technique. With this new method we have tried not only to remove the inconsistency of Kernelized Fuzzy C-Means clustering technique but also to deal with the situations where the number of clusters is not predetermined. We have also provided a comparison of our method with the Subtractive clustering technique of Chiu and Kernelized Fuzzy C-Means clustering technique using two validity measures namely Partition Coefficient and Clustering Entropy.

  19. MRI findings of congenita dysosmia

    International Nuclear Information System (INIS)

    You Hui; Feng Feng; Liu Jianfeng; Wu Xueyan; Wang Jian; Ni Daofeng; Sun Hongyi; Chen Jun; Jin Zhengyu

    2009-01-01

    Objective: To study the MRI findings of congenital dysosmia. Methods: Forty-seven patients with congenital dysosmia (39 with Kallmann syndrome and 8 with isolated dysosmia) and 21 normal volunteers underwent MRI examination. The features of congenital malformation were recorded. The volume of olfactory bulbs, depth of olfactory sulci as well as diameters of pituitary glands and stalks were measured. The rate of dysplasia of olfactory bulbs and tracts in the two patients groups was compared with X 2 test. The difference of volume of olfactory bulbs between the two groups was evaluated with nonparametric test. And the difference of diameters of pituitary glands and stalks was analyzed with analysis of variance. Results: All the patients had abnormal findings in olfactory bulbs, tracts and/or olfactory sulci on MR images. The patterns of congenital malformation may be dysplastic of hypoplastic, symmetric or asymmetric. The proportion of patients with dysplasia of olfactory bulbs and tracts in Kallmann syndrome patients (31/39) was higher than that in isolated dysosmia ones (2/8) (X 2 = 6.998, P =0.008), and the olfactory bulbs'volume of patients with Kallmann syndrome (median 8 mm 3 ) was smaller than that of patients with isolated dysosmia (median 22 mm 3 ) (Z = -2.902, P =0.004). The pituitary glands were smaller and the stalks were thinner in patients with Kallmann syndrome than those in volunteers [ the anteroposterior diameter of pituitary glands in Kallmann syndrome (7.22 ± 1.93) mm, that in normal volunteers (9.94 ± 1.59) mm, F= 16.835, P =0.000; height of pituitary glands in Kallmann syndrome (3.71 ± 1.74) mm, that in normal volunteers (6.00 ± 1.24) mm, F =16.092, P =0.000; the anteroposterior diameter of pituitary stalks in Kallmann syndrome (1.19 ± 0.55) mm, that in normal volunteers (1.88 ± 0.49) mm, F =13.060, P =0.000]. Conclusions: In congenital dysosmic patients, dysplasia or hypoplasia of olfactory bulbs, tracts and sulci can be clearly depicted

  20. Correlation of Imaging Findings with Pathologic Findings of Sclerosing Adenosis

    International Nuclear Information System (INIS)

    Choi, Bo Bae; Shu, Kwang Sun

    2012-01-01

    The purpose of this study was to evaluate the mammographic and sonographic findings of pure sclerosing adenosis. We retrospectively reviewed the mammographic and sonographic findings in 40 cases of pure sclerosing adenosis confirmed by core needle biopsy (n = 23), vacuum-assisted biopsy (n = 7), excision biopsy (n = 9), and lumpectomy (n = 1) from January 2002 to March 2010. All imaging findings were analyzed according to the American College of Radiology (ACR) breast imaging reporting and data system (BI-RADS). Radiologic features were correlated with pathologic findings. Although most mammograms showed negative findings (57%), calcification was the most common abnormal finding of sclerosing adenosis. On sonography, the most common finding was a circumscribed oval hypoechoic mass without posterior features (78%). Most masses showed BI-RADS category 3, (75%, 27/36). Five cases showed categories 4 or 5 (14%, 5/36). Most mammographic and sonographic findings of sclerosing adenosis are non-specific and non-pathognomonic, even though sometimes sclerosing adenosis can be radiologically or histopathologically confused with malignancy

  1. Simple method of obtaining the band strengths in the electronic spectra of diatomic molecules

    International Nuclear Information System (INIS)

    Gowda, L.S.; Balaji, V.N.

    1977-01-01

    It is shown that relative band strengths of diatomic molecules for which the product of Franck-Condon factor and r-centroid is approximately equal to 1 for (0,0) band can be determined by a simple method which is in good agreement with the smoothed array of experimental values. Such values for the Swan bands of the C 2 molecule are compared with the band strengths of the simple method. It is noted that the Swan bands are one of the outstanding features of R- and N-type stars and of the heads of comets

  2. Finding costs methodology - alternative approaches

    International Nuclear Information System (INIS)

    Gaddis, D.

    1992-01-01

    Though the context may vary, the topic of the day in the oil and gas industry is ''finding costs per barrel.'' First, there have been numerous articles in both the popular media and the industry press that have argued it is cheaper for companies to buy reserves that find them with the drill bit. Financial analysts have emphasized the importance of comparing relative finding costs when evaluating different companies. The success of failure of a company's management has been judged on the basis of finding costs. In discussing oil and gas prices, economists commonly refer to the relationship between the market prices of oil and gas and their finding costs, and no discussion of the U.S. petroleum industry and the development of a national energy policy is complete without reference to finding costs. (Author)

  3. An Investigation of the Academic Information Finding and Re-finding Behavior on the Web

    Directory of Open Access Journals (Sweden)

    Hsiao-Tieh Pu

    2014-12-01

    Full Text Available Academic researchers often need and re-use relevant information found after a period of time. This preliminary study used various methods, including experiments, interviews, search log analysis, sequential analysis, and observation to investigate characteristics of academic information finding and re-finding behavior. Overall, the participants in this study entered short queries either in finding or re-finding phases. Comparatively speaking, the participants entered greater number of queries, modified more queries, browsed more web pages, and stayed longer on web pages in the finding phase. On the other hand, in the re-finding phase, they utilized personal information management tools to re-find instead of finding again using search engine, such as checking browsing history; moreover, they tend to input less number of queries and stayed shorter on web pages. In short, the participants interacted more with the retrieval system during the finding phase, while they increased the use of personal information management tools in the re-finding phase. As to the contextual clues used in re-finding phase, the participants used less clues from the target itself, instead, they used indirect clues more often, especially location-related information. Based on the results of sequential analysis, the transition states in the re-finding phase was found to be more complex than those in the finding phase. Web information finding and re-finding behavior is an important and novel area of research. The preliminary results would benefit research on Web information re-finding behavior, and provide useful suggestions for developing personal academic information management systems. [Article content in Chinese

  4. Defecography - analysis of qualitative findings

    International Nuclear Information System (INIS)

    Schott, U.; Braunschweig, R.; Claussen, C.D.

    1994-01-01

    The defectography is an examination of the anorectal function in defecatory disorder. The defecography has a diagnostic impact on disease, which only emerge during defecation as intussusception, enterocele, prolapse or sphincter dysfunction. Other findings as rectocele or descending pelvic floor are ambiguous concerning clinical relevance. The interpretation of defecography should include patient's history and clinical findings and - if available -endoscopic and manometric findings. (orig.) [de

  5. Imaging findings of sacral tumors

    International Nuclear Information System (INIS)

    Kim, Seung Ho; Hong, Sung Hwan; Choi, Ja Young; Koh, Sung Hye; Chung, Hye Won; Choi, Jung Ah; Kang, Heung Sik

    2003-01-01

    The various pathologic conditions detected at CT and MRI and subsumed by the term 'sacral tumor' include primary bone tumors, sacral canal tumors and metastases. Among these, metastases are much more common than primary bone tumors, of which chordoma is the most common. Although the imaging findings of sacral tumors are nonspecific, a patient's age and sex, and specific findings such as calcification or fluid-fluid levels, can help radiologists in their differential diagnosis. We describe the imaging findings of primary sacral tumors, emphasizing the MRI findings

  6. CT findings of infant epilepsy

    International Nuclear Information System (INIS)

    Hojoh, Hiroatsu; Kataoka, Kenkichi; Nakagawa, Yoshihiro; Nakano, Shozo; Tomita, Yutaka.

    1982-01-01

    CT diagnosis of infantile epilepsy was evaluated. High incidence of abnormal CT findings in infantile spasms and Lennox-Gastaut syndrome was same as in other reports. Comparison between CT findings and neurological complications and that between CT findings and electroencephalogram findings revealed a stronger relationship existing in the former. This suggested that CT is more useful as a measure to detect underlying diseases which are due to organic change of the brain to cause epilepsy, rather than as that to disclose epileptic primary lesions of functional change. (Ueda, J.)

  7. Radiologic findings of thoracic trauma

    Directory of Open Access Journals (Sweden)

    Akgul Ozmen C

    2017-08-01

    Full Text Available Cihan Akgul Ozmen,1 Serdar Onat,2 Delal Aycicek3 1Department of Radiology, 2Department of Chest Surgery, Dicle University School of Medicine, Diyarbakir, 3Radiology Unit, Siirt State Hospital, Siirt, Turkey Introduction: Chest trauma may be blunt or penetrating and the chest is the third most common trauma region. It is a significant cause of mortality. Multidetector computed tomography (MDCT has been an increasingly used method to evaluate chest trauma because of its high success in detecting tissue and organ injuries. Herein, we aimed to present MDCT findings in patients with blunt and penetrating chest trauma admitted to our department. Methods: A total of 240 patients admitted to the emergency department of our hospital between April 2012 and July 2013 with a diagnosis of chest trauma who underwent MDCT evaluations were included. Most of the patients were male (83.3% and victims of a blunt chest trauma. The images were analyzed with respect to the presence of fractures of bony structures, hemothorax, pneumothorax, mediastinal organ injury, and pulmonary and vascular injuries. Results: MDCT images of the 240 patients yielded a prevalence of 41.7% rib fractures, 11.2% scapular fractures, and 7.5% clavicle fractures. The prevalence of thoracic vertebral fracture was 13.8% and that of sternal fracture was 3.8%. The prevalence of hemothorax, pneumothorax, pneumomediastinum, and subcutaneous emphysema was 34.6%, 62.1%, 9.6%, and 35.4%, respectively. The prevalence of rib, clavicle, and thoracic vertebral fractures and pulmonary contusion was higher in the blunt trauma group, whereas the prevalence of hemothorax, subcutaneous emphysema, diaphragmatic injury, and other vascular lacerations was significantly higher in the penetrating trauma group than in the blunt trauma group (p<0.05. Conclusion: MDCT images may yield a high prevalence of fracture of bony structures, soft tissue lacerations, and vascular lesions, which should be well understood by

  8. CT findings of pancreatic disease

    International Nuclear Information System (INIS)

    Lee, Mi Sook; Park, In Sook; Jeon, Doo Sung; Kim, Hong Soo; Rhee, Hak Song; Won, Jong Jin

    1988-01-01

    CT was found to be a reliable, often specific, and noninvasive method for detecting pancreatic diseases. In a study of pancreatic lesions, 37 cases having satisfactory operative and histological proofs were analyzed by CT at PMC from Jan. 1986 to Oct. 1987. The results were as following: 1. Male:female is 26:11. 2. The incidence of pancreatic disease were as follows: 1) Pancreatic cancer:21 cases (56%) a.Head:12 cases b.Body:4 cases c.Tail:1 case d.Body and tail:1 case e.Uncinate process:2 cases f.Entire pancreas: 1 case 2) Acute pancreatitis: 6 cases (16%) 3) Chronic pancreatitis:5 cases (14%) 3. The characteristic CT findings: 1) 100% of pancreatic head cancer showed focal mass or alteration of pancreatic head contour and biliary tree dilatation, and 33% (7/12) fat line obliteration. 2) All of other pancreatic cancer except head appeared as focal mass or contour alteration and fat line obliteration. 3) Total 6 cases of acute pancreatitis showed that 5 cases diffuse enlargement of pancreas, 3 fluid collection (2 cases:left anterior pararenal and posterior pararenal space and lesser sac, 1 case:only pancreas body) and 1 case abscess formation. 4) Total 5 cases of chronic pancreatitis revealed diffuse enlargement 2 cases and atrophy 1 case, pancreatic ductal dilatation 3 cases, calcification 2 cases, and biliary tree dilatation with CBD tapering appearance 1 case. 5) All cases of pseudocysts were well marginated cystic lesions that located at head in 3 cases and tail 3 cases, and 4 cases were well defined pure cystic masses but 1 case was well capsulated cyst with multiple internal septation

  9. Post-therapeutic imaging findings

    Energy Technology Data Exchange (ETDEWEB)

    Pollice, Saverio, E-mail: saveriopollice@hotmail.it [Department of Radiology and Neuroradiology, “L. Bonomo Hospital”, 76123 Andria, BT (Italy); Muto, Mario, E-mail: mutomar@tiscali.it [Department of Neuroradiology, “Cardarelli Hospital”, Naples (Italy); Scarabino, Tommaso, E-mail: tscarabino@hotmail.com [Department of Radiology and Neuroradiology, “L. Bonomo Hospital”, 76123 Andria, BT (Italy)

    2015-05-15

    Highlights: • This study is the result of collaboration between neuroradiologists and neurosurgeons. • Comparison between neuroimaging techniques to better evaluate the complications after treatment of the spin. • Evaluation of the imaging features of complications and definition of follow-up. - Abstract: Any surgical approach modifies the normal anatomical and functional arrangement of the segmental spine which is aimed, therefore image interpretation cannot ignore a correct set of knowledge in the field of anatomy, pathophysiology, drug compliance, interventional radiology and surgery. Neuroradiological imaging has an important role before surgery to direct the surgeon or interventional radiologist during the operation, both in post-surgery, where imaging examination can rightly evaluate properties and effects of the treatment and can detect potential complications as infections, abscess, bleeding, exuberant scar, mobilization and rupture of devices. The available methods of imaging are the X-rays (XR) made at least in two projections, Computed Tomography (CT) with MPR (multiplanar) and VR (volume rendering) reconstruction, and Magnetic Resonance (MR), often performed before and after contrast media injection. Imaging assessment of spine after surgery is complex and depends upon several factors, including surgical procedures and disease for which it was performed; biomechanical of the underlying cortical and cancellous bone findings; conditions of muscles, intervertebral disk and ligaments; time since surgery procedures; duration and nature of the post-surgical syndrome. Depending upon several factors, one or a combination of complementary imaging modalities (X-rays, Computed Tomography, Magnetic Resonance) may be required to evaluate effectiveness of the treatment; to demonstrate any clinically relevant abnormality at the treated region and adjacent structures (complications such as inflammation, abscesses, bleeding and misplacement of the device); to

  10. Post-therapeutic imaging findings

    International Nuclear Information System (INIS)

    Pollice, Saverio; Muto, Mario; Scarabino, Tommaso

    2015-01-01

    Highlights: • This study is the result of collaboration between neuroradiologists and neurosurgeons. • Comparison between neuroimaging techniques to better evaluate the complications after treatment of the spin. • Evaluation of the imaging features of complications and definition of follow-up. - Abstract: Any surgical approach modifies the normal anatomical and functional arrangement of the segmental spine which is aimed, therefore image interpretation cannot ignore a correct set of knowledge in the field of anatomy, pathophysiology, drug compliance, interventional radiology and surgery. Neuroradiological imaging has an important role before surgery to direct the surgeon or interventional radiologist during the operation, both in post-surgery, where imaging examination can rightly evaluate properties and effects of the treatment and can detect potential complications as infections, abscess, bleeding, exuberant scar, mobilization and rupture of devices. The available methods of imaging are the X-rays (XR) made at least in two projections, Computed Tomography (CT) with MPR (multiplanar) and VR (volume rendering) reconstruction, and Magnetic Resonance (MR), often performed before and after contrast media injection. Imaging assessment of spine after surgery is complex and depends upon several factors, including surgical procedures and disease for which it was performed; biomechanical of the underlying cortical and cancellous bone findings; conditions of muscles, intervertebral disk and ligaments; time since surgery procedures; duration and nature of the post-surgical syndrome. Depending upon several factors, one or a combination of complementary imaging modalities (X-rays, Computed Tomography, Magnetic Resonance) may be required to evaluate effectiveness of the treatment; to demonstrate any clinically relevant abnormality at the treated region and adjacent structures (complications such as inflammation, abscesses, bleeding and misplacement of the device); to

  11. Urologic diseases in America Project: analytical methods and principal findings.

    Science.gov (United States)

    Litwin, Mark S; Saigal, Christopher S; Yano, Elizabeth M; Avila, Chantal; Geschwind, Sandy A; Hanley, Jan M; Joyce, Geoffrey F; Madison, Rodger; Pace, Jennifer; Polich, Suzanne M; Wang, Mingming

    2005-03-01

    The burden of urological diseases on the American public is immense in human and financial terms but it has been under studied. We undertook a project, Urologic Diseases in America, to quantify the burden of urological diseases on the American public. We identified public and private data sources that contain population based data on resource utilization by patients with benign and malignant urological conditions. Sources included the Centers for Medicare and Medicaid Services, National Center for Health Statistics, Medical Expenditure Panel Survey, National Health and Nutrition Examination Survey, Department of Veterans Affairs, National Association of Children's Hospitals and Related Institutions, and private data sets maintained by MarketScan Health and Productivity Management (MarketScan, Chichester, United Kingdom), Ingenix (Ingenix, Salt Lake City, Utah) and Center for Health Care Policy and Evaluation. Using diagnosis and procedure codes we described trends in the utilization of urological services. In 2000 urinary tract infections accounted for more than 6.8 million office visits and 1.3 million emergency room visits, and 245,000 hospitalizations in women with an annual cost of more than 2.4 billion dollars. Urinary tract infections accounted for more than 1.4 million office visits, 424,000 emergency room visits and 121,000 hospitalizations in men with an annual cost of more than 1 billion dollars. Benign prostatic hyperplasia was the primary diagnosis in more than 4.4 million office visits, 117,000 emergency room visits and 105,000 hospitalizations, accounting for 1.1 billion dollars in expenditures that year. Urolithiasis was the primary diagnosis for almost 2 million office visits, more than 600,000 emergency room visits, and more than 177,000 hospitalizations, totaling more than 2 billion dollars in annual expenditures. Urinary incontinence in women was the primary cause for more than 1.1 million office visits in 2000 and 452 million dollars in aggregate primary cause for more than 1.1 million office visits in 2000 and 452 million dollars in aggregate annual expenditures. Other manuscripts in this series present further detail for specific urologic conditions. Recent trends in epidemiology, practice patterns, resource utilization and costs for urological diseases have broad implications for quality of health care, access to care and the equitable allocation of scarce resources for clinical care and research.

  12. Methods for Finding Legacy Wells in Residential and Commercial Areas

    Energy Technology Data Exchange (ETDEWEB)

    Hammack, Richard [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States); Veloski, Garret [National Energy Technology Lab. (NETL), Pittsburgh, PA, (United States)

    2016-06-06

    The objective of this study was to locate legacy wells in Versailles Borough so that the Pennsylvania Department of Environmental Protection could mitigate dangerous CH4 concentrations in the community by venting or plugging leaking wells.

  13. Neuroradiological methods and findings on presurgical evaluation of epileptic children

    International Nuclear Information System (INIS)

    Ostertun, B.; Elger, C.E.; Solymosi, L.; Kurthen, M.; Schramm, J.

    1993-01-01

    Epilepsy in childhood is often caused by morphological abnormalities and is frequently pharmacoresistant. Therefore it represents a challenge to the neuroradiologist because early and accurate diagnosis of abnormal morphology is the basis for planning surgical intervention with a high change of controlling seizures and a low risk of complications. Both morphological (radiography, CT, MRI and angiography) and functional examinations [intracarotid amobarbital test (IAT)] are essential parts of the presurgical evaluation. In most cases MRI has proved to be most sensitive in detecting lesions except for some calcifications. Routine protocols for brain examinations are not sufficient, missing about 22% of lesions. Therefore a refined MRI and CT protocol is proposed. Even in very young children IAT can be performed at very low risk; these tests contribute highly valuable information about hemispheric dominance and other functions in more than 80% of procedures that is indispensable if postoperative neurological and neuropsychological deficits are to be avoided. (orig.) [de

  14. Clinical and Proctosigmoidoscopic findings in Patients with ...

    African Journals Online (AJOL)

    Background: Anorectal sepsis is a distressing condition which is sometimes inadequately treated. Objectives: To determine the clinical and prostosigmoidoscopic findings in patients with anorectal sepsis seen by the authors over a 5 year period as well as identifying the commonly performed procedures. Method: A review of ...

  15. On König's root finding algorithms

    DEFF Research Database (Denmark)

    Buff, Xavier; Henriksen, Christian

    2003-01-01

    In this paper, we first recall the definition of a family of root-finding algorithms known as König's algorithms. We establish some local and some global properties of those algorithms. We give a characterization of rational maps which arise as König's methods of polynomials with simple roots. We...

  16. Pollution! Find a STEM solution!

    Science.gov (United States)

    Takač, Danijela; Moćan, Marina

    2016-04-01

    Primary and secondary school Pantovčak is an innovative school in downtown Zagreb, Croatia. The school is involved in many projects concerning STEM education. Pollution! Find a STEM solution! is a two year long cross-curricular project that grew out of identified need to develop STEM and ICT skills more. Pisa results make evident that students' knowledge is poor and motivation for math and similar subjects is low. Implying priorities of European Commission, like e-learning, raises motivation and also develops basic skills and improves knowledge in science, math, physic, ICT. Main objectives are to increase students' interest in STEM education and careers and introduce them to all available new trends in technology, engineering and science in their region by visiting clean technology industries and strengthening links with them, to introduce some future digital jobs and prepare students for rapid technological changes by integrating ICT into classroom practice more, to highlight the importance of global environmental issues and improve the knowledge in the areas of sustainable development and renewable energy, to develop collaborative partnership between schools and the wider community in formal, non-formal and informal learning, to support multilingualism by publishing Open Educational Resources in 8 different languages and to strengthen the professional profile of the teaching profession. The project brings together 231 teachers and 2729 students from five different European countries in learning to think globally and work on activities that contribute to the community's well-being. There are altogether 33 activities, divided in 4 categories. STEM activities are focused on students building the devices for measuring air, light and noise pollution in their school and homes. They use the scientific method to analyze the data and compare the results with their peers to find a solution. Eskills, digital literacy and digital jobs are focused on introducing career

  17. CT findings of necrotizing pneumonia

    International Nuclear Information System (INIS)

    Kim, Hyae Young; Im, Jung Gi; Whang, Sung Il; Cheon, Jung Eun; Lee, Jae Kyo; Song, Jae Woo

    1998-01-01

    Necrotizing pneumonia causes necrosis of pulmonary parenchyma and may lead to pulmonary gangrene. Prior to the antibiotic era, extensive pulmonary involvement was potentially fatal, but the incidence of necrotizing pneumoniais now less common. On contrast-enhanced CT scans, consolidation with contrast enhancement containing necrotic foci with low attenuation and cavities is characteristic. Radiologic findings do not differ according to the causative organism and in most of cases, specific diagnosis may be impossible. Clinical findings and certain characteristic radiologic findings may be helpful for narrowing the differential diagnosis. We illustrate the clinical and radiologic characteristics of necrotizing pneumonia according to causative bacterial organisms

  18. Imaging findings of sternal abnormalities

    International Nuclear Information System (INIS)

    Franquet, T.; Gimenez, A.; Alegret, X.; Sanchis, E.; Rivas, A.

    1997-01-01

    Radiographic findings in the sternal abnormalities are often nonspecific, showing appearances from a localized benign lesion to an aggressive lesion as seen with infections and malignant neoplasms. A specific diagnosis of sternal abnormalities can be suggested on the basis of CT and MR characteristics. Familiarity with the presentation and variable appearance of sternal abnormalities may aid the radiologist is suggesting a specific diagnosis. We present among others characteristic radiographic findings of hemangioma, chondrosarcoma, hydatid disease, and SAPHO syndrome. In those cases in which findings are not specific, cross-sectional imaging modalities may help the clinician in their management. (orig.)

  19. CT findings in Reye syndrome

    International Nuclear Information System (INIS)

    Lee, Kil Woo; Lim, Hyo Keun; Choo, In Wook; Bae, Sang Hoon

    1990-01-01

    We present here the CT findings in 10 patients with Reye syndrome. Acute findings is diffuse cerebral swelling with or without parenchymal low density. The cerebral swelling gradually changed to atrophy. The parenchymal low density predisposes in Lt temporoparietal area. Contrast enhanced CT scan showed no additional finding, except 1 case. The hemorrhagic infarction which has not been reported previously was seen in 1 case and resulted in the most prominent sequela. The sequelae were developed in all atrophic cases. So, the brain CT may be useful in monitoring cerebral swelling, determining treatment plan in acute stage, and in presenting prognosis and sequelae on fellow up CT

  20. CT findings of pulmonary aspergillosis

    International Nuclear Information System (INIS)

    Cheon, Jung Eun; Im, Jung Gi; Goo, Jin Mo; Kim, Hong Dae; Han, Man Chung

    1995-01-01

    The fungus aspergillus can cause a variety of pulmonary disorders. Aspergilloma is a noninvasive aspergillus colonization of virtually any type of preexisting pulmonary cavity or cystic space. Invasive pulmonary aspergillosis is serious, usually fatal infection in patients being treated with immunosuppressants or who have chronic debilitating disease. Allergic bronchopulmonary aspergillosis is characterized clinically by asthma, blood and sputum eosinophilia and positive immunologic reaction to aspergillus antigen. Awareness of the radiographic and CT findings of pulmonary aspergillosis is important in making the diagnosis of aspergillus-caused pulmonary disorders. In this pictorial essay, we illustrated various radiological findings of pulmonary aspergillosis focused on CT findings correlated with gross pathologic specimens

  1. HRCT findings of scrub typhus

    International Nuclear Information System (INIS)

    Kim, Kyu Sik; Kang, Sung Soo; Jin, Kong Yong; Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Chung, Gyung Ho; Lee, Sang Yong; Sohn, Myung Hee; Choi, Ki Chul

    1997-01-01

    To evaluate high-resolution CT (HRCT) findings of scrub typhus. We retrospectively reviewed the HRCT scans of 26 serologically confirmed scrub typhus patients. One underwent follow-up HRCT scanning. Twenty-three(88.5%) of the 26 patients showed abnormal findings. All 23 had lung parenchymal lesions; a small amount of pleural effusion was seen in 11 patients, and lymphadenopathy in six. The predominant parenchymal lesion was thickening of interlobular septae and the axial and intralobular interstitium (n=16). Most lesions were located in both lower lung zones. Other findings were ground-glass attenuation (n=11) and focal parenchymal consolidation (n=8). In one patient, parenchymal lesions were resolved on follow-up HRCT scanning. HRCT findings of interstitial thickening, abnormally increased parenchymal attenuation, pleural effusion and lymphadenopathy with typical clinical symptoms were diagnostic of scrub typhus

  2. HRCT findings of scrub typhus

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Kyu Sik; Kang, Sung Soo; Jin, Kong Yong; Lee, Jeong Min; Han, Young Min; Kim, Chong Soo; Chung, Gyung Ho; Lee, Sang Yong; Sohn, Myung Hee; Choi, Ki Chul [Chonbuk National Univ. Medical School, Chonju (Korea, Republic of)

    1997-06-01

    To evaluate high-resolution CT (HRCT) findings of scrub typhus. We retrospectively reviewed the HRCT scans of 26 serologically confirmed scrub typhus patients. One underwent follow-up HRCT scanning. Twenty-three(88.5%) of the 26 patients showed abnormal findings. All 23 had lung parenchymal lesions; a small amount of pleural effusion was seen in 11 patients, and lymphadenopathy in six. The predominant parenchymal lesion was thickening of interlobular septae and the axial and intralobular interstitium (n=16). Most lesions were located in both lower lung zones. Other findings were ground-glass attenuation (n=11) and focal parenchymal consolidation (n=8). In one patient, parenchymal lesions were resolved on follow-up HRCT scanning. HRCT findings of interstitial thickening, abnormally increased parenchymal attenuation, pleural effusion and lymphadenopathy with typical clinical symptoms were diagnostic of scrub typhus.

  3. Disclosing finding and development costs

    International Nuclear Information System (INIS)

    Janisch, M.L.

    1998-01-01

    The importance of finding and development costs in the petroleum industry and the issue of how they can be either manipulated or misunderstood was discussed. Finding and development costs are usually expressed in terms of $/BOE (barrel of oil equivalents) and reflect the total capital expenditures divided by the total reserves replaced and added. Various examples of the importance of finding and development costs in making investment decisions were used to illustrate the effects of potential bias by the resource company, and the need for care and understanding of what the numbers issued by the company actually mean. In general, low and consistent finding and development costs, combined with good netbacks, are the key to value added for shareholders. tabs

  4. Learning as way-finding

    DEFF Research Database (Denmark)

    Dau, Susanne

    motions of humans and non-human agencies. The findings reveal that learning; formal and informal can be conceptualized by the metaphor of way-finding; embodied, emotionally and/or cognitive both individually and socially. Way-finding, is argued, to be a contemporary concept for learning processes......, knowledge development and identity-shaping, where learning emerges through motions, feeling and thinking within an information rich world in constant change.......Based on empirical case-study findings and the theoretical framework of learning by Illeris coupled with Nonaka & Takeuchis´s perspectives on knowledge creation, it is stressed that learning are conditioned by contextual orientations-processes in spaces near the body (peripersonal spaces) through...

  5. Find an Endocrinology - Thyroid Specialist

    Science.gov (United States)

    ... History Resource Center Patients Thyroid Information Find an Endocrinology – Thyroid Specialist Patient Support Links Clinical Thyroidology for ... Access Thyroid Online Access Clinical Thyroidology Online Video Endocrinology Donate Give Online Research Accomplishments Ridgway Legacy Fund ...

  6. Dermoscopy Findings of Hidroacanthoma Simplex

    Directory of Open Access Journals (Sweden)

    Yota Sato

    2014-05-01

    Full Text Available Hidroacanthoma simplex (HAS, also known as intraepidermal eccrine poroma, is a rare eccrine adnexal tumor that tends to be misdiagnosed as other types of benign skin tumor, including clonal seborrheic keratosis. Notably, HAS is sometimes misdiagnosed and treated by cryosurgery as seborrheic keratosis, which could trigger the later development of porocarcinoma. Therefore, accurate diagnosis of HAS is indispensable for dermatologists to avoid the development of malignant tumors by an unsuitable treatment. In this report, we present the characteristic dermoscopy findings of HAS. Indeed, the dermoscopy findings might be related to the melanin-rich necrotic cells in the epidermis, which are quite different from dermoscopy findings of clonal seborrheic keratosis. As a previous report suggested, it is difficult for a dermatologist to differentiate HAS from clonal seborrheic keratosis by the naked eye. Our findings might be supportive for the early diagnosis of HAS.

  7. Finding an Eye Care Professional

    Science.gov (United States)

    ... article rating hospitals in the United States. Website: http://health.usnews.com/best-hospitals For More Information ... ophthalmologists in the United States and abroad. Website: https://secure.aao.org/aao/find-ophthalmologist The American ...

  8. Finding Direction in the Search for Selection.

    Science.gov (United States)

    Thiltgen, Grant; Dos Reis, Mario; Goldstein, Richard A

    2017-01-01

    Tests for positive selection have mostly been developed to look for diversifying selection where change away from the current amino acid is often favorable. However, in many cases we are interested in directional selection where there is a shift toward specific amino acids, resulting in increased fitness in the species. Recently, a few methods have been developed to detect and characterize directional selection on a molecular level. Using the results of evolutionary simulations as well as HIV drug resistance data as models of directional selection, we compare two such methods with each other, as well as against a standard method for detecting diversifying selection. We find that the method to detect diversifying selection also detects directional selection under certain conditions. One method developed for detecting directional selection is powerful and accurate for a wide range of conditions, while the other can generate an excessive number of false positives.

  9. CompaRNA: a server for continuous benchmarking of automated methods for RNA secondary structure prediction

    Science.gov (United States)

    Puton, Tomasz; Kozlowski, Lukasz P.; Rother, Kristian M.; Bujnicki, Janusz M.

    2013-01-01

    We present a continuous benchmarking approach for the assessment of RNA secondary structure prediction methods implemented in the CompaRNA web server. As of 3 October 2012, the performance of 28 single-sequence and 13 comparative methods has been evaluated on RNA sequences/structures released weekly by the Protein Data Bank. We also provide a static benchmark generated on RNA 2D structures derived from the RNAstrand database. Benchmarks on both data sets offer insight into the relative performance of RNA secondary structure prediction methods on RNAs of different size and with respect to different types of structure. According to our tests, on the average, the most accurate predictions obtained by a comparative approach are generated by CentroidAlifold, MXScarna, RNAalifold and TurboFold. On the average, the most accurate predictions obtained by single-sequence analyses are generated by CentroidFold, ContextFold and IPknot. The best comparative methods typically outperform the best single-sequence methods if an alignment of homologous RNA sequences is available. This article presents the results of our benchmarks as of 3 October 2012, whereas the rankings presented online are continuously updated. We will gladly include new prediction methods and new measures of accuracy in the new editions of CompaRNA benchmarks. PMID:23435231

  10. Investigation on method of estimating the excitation spectrum of vibration source

    International Nuclear Information System (INIS)

    Zhang Kun; Sun Lei; Lin Song

    2010-01-01

    In practical engineer area, it is hard to obtain the excitation spectrum of the auxiliary machines of nuclear reactor through direct measurement. To solve this problem, the general method of estimating the excitation spectrum of vibration source through indirect measurement is proposed. First, the dynamic transfer matrix between the virtual excitation points and the measure points is obtained through experiment. The matrix combined with the response spectrum at the measure points under practical work condition can be used to calculate the excitation spectrum acts on the virtual excitation points. Then a simplified method is proposed which is based on the assumption that the vibration machine can be regarded as rigid body. The method treats the centroid as the excitation point and the dynamic transfer matrix is derived by using the sub structure mobility synthesis method. Thus, the excitation spectrum can be obtained by the inverse of the transfer matrix combined with the response spectrum at the measure points. Based on the above method, a computing example is carried out to estimate the excitation spectrum acts on the centroid of a electrical pump. By comparing the input excitation and the estimated excitation, the reliability of this method is verified. (authors)

  11. Fault Diagnosis of Rotating Machinery Based on the Multiscale Local Projection Method and Diagonal Slice Spectrum

    Directory of Open Access Journals (Sweden)

    Yong Lv

    2018-04-01

    Full Text Available The vibration signals of bearings and gears measured from rotating machinery usually have nonlinear, nonstationary characteristics. The local projection algorithm cannot only reduce the noise of the nonlinear system, but can also preserve the nonlinear deterministic structure of the signal. The influence of centroid selection on the performance of noise reduction methods is analyzed, and the multiscale local projection method of centroid was proposed in this paper. This method considers both the geometrical shape and statistical error of the signal in high dimensional phase space, which can effectively eliminate the noise and preserve the complete geometric structure of the attractors. The diagonal slice spectrum can identify the frequency components of quadratic phase coupling and enlarge the coupled frequency component in the nonlinear signal. Therefore, the proposed method based on the above two algorithms can achieve more accurate results of fault diagnosis of gears and rolling bearings. The simulated signal is used to verify its effectiveness in a numerical simulation. Then, the proposed method is conducted for fault diagnosis of gears and rolling bearings in application researches. The fault characteristics of faulty bearings and gears can be extracted successfully in the researches. The experimental results indicate the effectiveness of the novel proposed method.

  12. CompaRNA: a server for continuous benchmarking of automated methods for RNA secondary structure prediction.

    Science.gov (United States)

    Puton, Tomasz; Kozlowski, Lukasz P; Rother, Kristian M; Bujnicki, Janusz M

    2013-04-01

    We present a continuous benchmarking approach for the assessment of RNA secondary structure prediction methods implemented in the CompaRNA web server. As of 3 October 2012, the performance of 28 single-sequence and 13 comparative methods has been evaluated on RNA sequences/structures released weekly by the Protein Data Bank. We also provide a static benchmark generated on RNA 2D structures derived from the RNAstrand database. Benchmarks on both data sets offer insight into the relative performance of RNA secondary structure prediction methods on RNAs of different size and with respect to different types of structure. According to our tests, on the average, the most accurate predictions obtained by a comparative approach are generated by CentroidAlifold, MXScarna, RNAalifold and TurboFold. On the average, the most accurate predictions obtained by single-sequence analyses are generated by CentroidFold, ContextFold and IPknot. The best comparative methods typically outperform the best single-sequence methods if an alignment of homologous RNA sequences is available. This article presents the results of our benchmarks as of 3 October 2012, whereas the rankings presented online are continuously updated. We will gladly include new prediction methods and new measures of accuracy in the new editions of CompaRNA benchmarks.

  13. Find selv fred og ro

    DEFF Research Database (Denmark)

    Juelskjær, Malou

    2010-01-01

    I klasseværelset er det lærerens ansvar at skabe ro. Men i de nye skolebygninger er det den enkelte elevs ansvar at finde frem til fredfyldte steder.......I klasseværelset er det lærerens ansvar at skabe ro. Men i de nye skolebygninger er det den enkelte elevs ansvar at finde frem til fredfyldte steder....

  14. CT findings in abdominal actinomycosis

    International Nuclear Information System (INIS)

    Lee, In Jae; Ha, Hyun Kwon; Lee, Moon Gyu; Kim, Pyo Nyun; Auh, Yong Ho

    1999-01-01

    Abdominal actinomycosis is a chronic, progressive, suppurative disease with a favorable response to intravenous treatment with penicillin. In many instances, however, its clinical and radiological findings may overlap with those of other inflammatory and neoplastic conditions, and the familiarity with the various radiological features can thus avoid diagnostic delays. The purpose of this paper is to describe and discuss the CT findings of abdominal actinomycosis

  15. Radiologic findings of granulomatous mastitis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Tae Gyu; Kim, Ji Young; Jeong, Myeong Ja; Kim, Jae Hyung; Kim, Soung Hee; Kim, Soo Hyun; Jun, Woo Sun; Park, Kyeong Mee; Han, Se Hwan [Paik Hospital, Inje University College of Medicine, Seoul (Korea, Republic of)

    2008-08-15

    The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment.

  16. Radiologic findings of granulomatous mastitis

    International Nuclear Information System (INIS)

    Kim, Tae Gyu; Kim, Ji Young; Jeong, Myeong Ja; Kim, Jae Hyung; Kim, Soung Hee; Kim, Soo Hyun; Jun, Woo Sun; Park, Kyeong Mee; Han, Se Hwan

    2008-01-01

    The describe the radiologic findings of granulomatous mastitis of the breast. This study included 19 patients (age range: 22 to 56 years; mean 37 years) with 22 lesions that were pathologically confirmed as having granulomatous mastitis. All the patients underwent a breast ultrasonography and 13 patients underwent a mammography. The results of the mammography revealed focal asymmetry (n = 9), multiple ill-defined isodense nodules (n 2), ill-defined nodular density on craniocaudal view (n = 1), and unremarkable finding (n = 1). The sonographic findings included continuous or discontinuous multiple tubular and nodular low echoic lesions (n = 7), ill-defined heterogeneously low echoic lesion (n = 5), irregular-shaped, ill-defined low echoic mass (n = 4), fluid collection with internal floating materials suggesting the presence of an abscess (n = 4), ill-defined heterogeneously low echoic lesion and abscess (n = 1), and multiple ill-defined nodules (n = 1). In the case of granulomatous mastitis, the mammography results indicate a lack of specificity between normal findings and focal asymmetry. The sonographic findings indicate that ill-defined heterogeneously low echoic lesions or irregular shaped, ill-defined low echoic masses are difficult to differentiate from breast cancer. The sonographic findings of abscesses indicate a difficulty in differentiating them from cases of pyogenic mastitis. However, multiple tubular and nodular low echoic lesions, especially with a continuous appearance, should point to granulomatous mastitis, and is helpful in its differential diagnosis and treatment

  17. CT findings of exophageal perforation

    Energy Technology Data Exchange (ETDEWEB)

    Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok [Hanyang University College of Medicine, Seoul (Korea, Republic of)

    2002-09-01

    To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening.

  18. CT findings of exophageal perforation

    International Nuclear Information System (INIS)

    Heo, Jeong Nam; Choi, Yo Won; Jeon, Seok Chol; Park, Choong Ki; Hahm, Chang Kok

    2002-01-01

    To determine which CT findings are useful for the early disgnosis of esophageal perforation, and on the basis of these findings, to assess the accuracy of prediction of the perforation site. A review of medical records indicated that between January 1995 and December 2001, 36 patients with esophageal perforation were admitted to our hospital. Thirteen of these [M:F=8:5, age; 28-69 (mean, 52.4) years], who had undergone CT chest scanning, were included in this study. The causes of esophageal perforation were trauma (n=5), infectious diseases (n=4), Boerhaave syndrome (n=1), lung cancer (n=1), esophageal cancer (n=1), and idiopathic. Two chest radiologists unaware of the clinical findings reviewed the CT scans and predicted whether the upper or lower esophagus was perforated. The most common CT finding was extraluminal air at the posterior mediastinum (n=11), while other findings included pulmonary consolidation (n=10), pleural effusion (n=7), discontinuity of the esophageal wall (n=6) and subcutaneous emphysema (n=4), fluid collection around the esophagus (n-4), esophageal wall thickening (n=4), pneumothorax (n=2), and lung abscess (n=2). The perforation site was accurately predicted in 76.9% of cases (10/13). The CT findings which help the diagnosis of esophageal perforation, and prediction of the sites at which it occurs, are extraluminal air of fluid collection, focal defect of the esophageal wall, and esophageal wall thickening

  19. Finding biomedical categories in Medline®

    Directory of Open Access Journals (Sweden)

    Yeganova Lana

    2012-10-01

    Full Text Available Abstract Background There are several humanly defined ontologies relevant to Medline. However, Medline is a fast growing collection of biomedical documents which creates difficulties in updating and expanding these humanly defined ontologies. Automatically identifying meaningful categories of entities in a large text corpus is useful for information extraction, construction of machine learning features, and development of semantic representations. In this paper we describe and compare two methods for automatically learning meaningful biomedical categories in Medline. The first approach is a simple statistical method that uses part-of-speech and frequency information to extract a list of frequent nouns from Medline. The second method implements an alignment-based technique to learn frequent generic patterns that indicate a hyponymy/hypernymy relationship between a pair of noun phrases. We then apply these patterns to Medline to collect frequent hypernyms as potential biomedical categories. Results We study and compare these two alternative sets of terms to identify semantic categories in Medline. We find that both approaches produce reasonable terms as potential categories. We also find that there is a significant agreement between the two sets of terms. The overlap between the two methods improves our confidence regarding categories predicted by these independent methods. Conclusions This study is an initial attempt to extract categories that are discussed in Medline. Rather than imposing external ontologies on Medline, our methods allow categories to emerge from the text.

  20. Imaging findings of xanthogranulomatous pyelonephritis

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jong Chul [School of Medicine, Chungnam National University, Taejon (Korea, Republic of)

    2000-01-01

    To define the imaging patterns of xanthogranulomatous pyelonephritis (XGP). The demographic, clinical, and imaging findings of 21 cases of pathologically proven XGP in 20 patients (bilateral in one) were evaluated. The findings of ultrasonography and CT were retrospectively evaluated with regard to distribution and extent of the disease, kidney size, the presence of calculi, hydronephrosis, and renal function. The findings were assessed by two radiologists, who established a consensus. Imaging and pathologic findings were compared. Sixteen of the 20 patients were female, and 19 were adults. Their age ranged from 3 to 16 (mean, 45) years. In all patients except one, the disease was unilateral (right: left =3D 13 :16). In one patient, XGP was bilateral, and there were thus 21 cases. Seventeen (81%) of these were diffuse, and four (19%) were focal; extrarenal extension occurred in 13 cases (62%), among which ipsilateral pleural effusion was noted in two. The kidney was enlarged diffusely in 12 cases (57%), and focally in three (14%); urinary calculi were present in 16 cases (76%), with staghorn calculi in four of these; and hydronephrosis occurred in 17 (81%). Impairment of ipsilateral renal function was noted in 13 cases (62%). Clinical findings of inflammation such as fever, pyuria, bacteriuria, or leucocytosis were noted in all patients. In addition to nephromegaly, renal function impairment, and urinary obstruction due to calculi, which are typical features of XGP, the condition may also show variable imaging findings. If the images obtained in the case of a middle-aged woman with clinical findings of urinary infection are atypical, we believe that XGP should be included in the differential diagnosis. (author)