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Sample records for random sampling procedure

  1. k-Means: Random Sampling Procedure

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. k-Means: Random Sampling Procedure. Optimal 1-Mean is. Approximation of Centroid (Inaba et al). S = random sample of size O(1/ ); Centroid of S is a (1+ )-approx centroid of P with constant probability.

  2. K-Median: Random Sampling Procedure

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. K-Median: Random Sampling Procedure. Sample a set of 1/ + 1 points from P. Let Q = first 1/ points, p = last point. Let T = Avg. 1-Median cost of P, c=1-Median. Let B1 = B(c,T/ 2), B2 = B(p, T). Let P' = points in B1.

  3. Comparison of transition-matrix sampling procedures

    DEFF Research Database (Denmark)

    Yevick, D.; Reimer, M.; Tromborg, Bjarne

    2009-01-01

    We compare the accuracy of the multicanonical procedure with that of transition-matrix models of static and dynamic communication system properties incorporating different acceptance rules. We find that for appropriate ranges of the underlying numerical parameters, algorithmically simple yet high...... accurate procedures can be employed in place of the standard multicanonical sampling algorithm....

  4. 32 CFR 1624.1 - Random selection procedures for induction.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 6 2010-07-01 2010-07-01 false Random selection procedures for induction. 1624... SYSTEM INDUCTIONS § 1624.1 Random selection procedures for induction. (a) The Director of Selective Service shall from time to time establish a random selection sequence for induction by a drawing to be...

  5. A single baseline ultrasound assessment of fibroid presence and size is strongly predictive of future uterine procedure: 8-year follow-up of randomly sampled premenopausal women aged 35-49 years.

    Science.gov (United States)

    Baird, D D; Saldana, T M; Shore, D L; Hill, M C; Schectman, J M

    2015-12-01

    How well can a single baseline ultrasound assessment of fibroid burden (presence or absence of fibroids and size of largest, if present) predict future probability of having a major uterine procedure? During an 8-year follow-up period, the risk of having a major uterine procedure was 2% for those without fibroids and increased with fibroid size for those with fibroids, reaching 47% for those with fibroids ≥ 4 cm in diameter at baseline. Uterine fibroids are a leading indication for hysterectomy. However, when fibroids are found, there are few available data to help clinicians advise patients about disease progression. Women who were 35-49 years old were randomly selected from the membership of a large urban health plan; 80% of those determined to be eligible were enrolled and screened with ultrasound for fibroids ≥ 0.5 cm in diameter. African-American and white premenopausal participants who responded to at least one follow-up interview (N = 964, 85% of those eligible) constituted the study cohort. During follow-up (5822 person-years), participants self-reported any major uterine procedure (67% hysterectomies). Life-table analyses and Cox regression (with censoring for menopause) were used to estimate the risk of having a uterine procedure for women with no fibroids, small (fibroids (≥ 4 cm). Differences between African-American and white women, importance of a clinical diagnosis of fibroids prior to study enrollment, and the impact of submucosal fibroids on risk were investigated. There was a greater loss to follow-up for African-Americans than whites (19 versus 11%). For those with follow-up data, 64% had fibroids at baseline, 33% of whom had had a prior diagnosis. Of those with fibroids, 27% had small fibroids (fibroid 2-3.9 cm in diameter), and 27% had large fibroids (largest ≥ 4 cm in diameter). Twenty-one percent had at least one submucosal fibroid. Major uterine procedures were reported by 115 women during follow-up. The estimated risk of having a

  6. A single baseline ultrasound assessment of fibroid presence and size is strongly predictive of future uterine procedure: 8-year follow-up of randomly sampled premenopausal women aged 35–49 years

    Science.gov (United States)

    Baird, D.D.; Saldana, T.M.; Shore, D.L.; Hill, M.C.; Schectman, J.M.

    2015-01-01

    STUDY QUESTION How well can a single baseline ultrasound assessment of fibroid burden (presence or absence of fibroids and size of largest, if present) predict future probability of having a major uterine procedure? SUMMARY ANSWER During an 8-year follow-up period, the risk of having a major uterine procedure was 2% for those without fibroids and increased with fibroid size for those with fibroids, reaching 47% for those with fibroids ≥4 cm in diameter at baseline. WHAT IS KNOWN ALREADY Uterine fibroids are a leading indication for hysterectomy. However, when fibroids are found, there are few available data to help clinicians advise patients about disease progression. STUDY DESIGN, SIZE, DURATION Women who were 35–49 years old were randomly selected from the membership of a large urban health plan; 80% of those determined to be eligible were enrolled and screened with ultrasound for fibroids ≥0.5 cm in diameter. African-American and white premenopausal participants who responded to at least one follow-up interview (N = 964, 85% of those eligible) constituted the study cohort. During follow-up (5822 person-years), participants self-reported any major uterine procedure (67% hysterectomies). Life-table analyses and Cox regression (with censoring for menopause) were used to estimate the risk of having a uterine procedure for women with no fibroids, small (fibroids (≥4 cm). Differences between African-American and white women, importance of a clinical diagnosis of fibroids prior to study enrollment, and the impact of submucosal fibroids on risk were investigated. PARTICIPANTS/MATERIALS, SETTING, METHODS There was a greater loss to follow-up for African-Americans than whites (19 versus 11%). For those with follow-up data, 64% had fibroids at baseline, 33% of whom had had a prior diagnosis. Of those with fibroids, 27% had small fibroids (fibroid 2–3.9 cm in diameter), and 27% had large fibroids (largest ≥4 cm in diameter). Twenty-one percent had at least one

  7. 7 CFR 42.121 - Sampling and inspection procedures.

    Science.gov (United States)

    2010-01-01

    ... recommence the above procedure. See § 42.123 for a flow diagram of the skip lot sampling plan. (b) Two... REGULATIONS STANDARDS FOR CONDITION OF FOOD CONTAINERS Skip Lot Sampling and Inspection Procedures § 42.121...

  8. Acceptance sampling using judgmental and randomly selected samples

    Energy Technology Data Exchange (ETDEWEB)

    Sego, Landon H.; Shulman, Stanley A.; Anderson, Kevin K.; Wilson, John E.; Pulsipher, Brent A.; Sieber, W. Karl

    2010-09-01

    We present a Bayesian model for acceptance sampling where the population consists of two groups, each with different levels of risk of containing unacceptable items. Expert opinion, or judgment, may be required to distinguish between the high and low-risk groups. Hence, high-risk items are likely to be identifed (and sampled) using expert judgment, while the remaining low-risk items are sampled randomly. We focus on the situation where all observed samples must be acceptable. Consequently, the objective of the statistical inference is to quantify the probability that a large percentage of the unsampled items in the population are also acceptable. We demonstrate that traditional (frequentist) acceptance sampling and simpler Bayesian formulations of the problem are essentially special cases of the proposed model. We explore the properties of the model in detail, and discuss the conditions necessary to ensure that required samples sizes are non-decreasing function of the population size. The method is applicable to a variety of acceptance sampling problems, and, in particular, to environmental sampling where the objective is to demonstrate the safety of reoccupying a remediated facility that has been contaminated with a lethal agent.

  9. GSAMPLE: Stata module to draw a random sample

    OpenAIRE

    Jann, Ben

    2006-01-01

    gsample draws a random sample from the data in memory. Simple random sampling (SRS) is supported, as well as unequal probability sampling (UPS), of which sampling with probabilities proportional to size (PPS) is a special case. Both methods, SRS and UPS/PPS, provide sampling with replacement and sampling without replacement. Furthermore, stratified sampling and cluster sampling is supported.

  10. CTEPP STANDARD OPERATING PROCEDURE FOR SAMPLE SELECTION (SOP-1.10)

    Science.gov (United States)

    The procedures for selecting CTEPP study subjects are described in the SOP. The primary, county-level stratification is by region and urbanicity. Six sample counties in each of the two states (North Carolina and Ohio) are selected using stratified random sampling and reflect ...

  11. Randomized trial to examine procedure-to-procedure transfer in laparoscopic simulator training

    DEFF Research Database (Denmark)

    Bjerrum, F; Sorensen, J L; Konge, L

    2016-01-01

    -centre educational superiority trial. Surgical novices practised basic skills on a laparoscopic virtual reality simulator. On reaching proficiency, participants were randomized to proficiency-based training. The intervention group practised two procedures on the simulator (appendicectomy followed by salpingectomy......BACKGROUND: Laparoscopic simulation has become a standard component of surgical training, but there is limited knowledge regarding skills transfer between procedural tasks. The objective was to investigate the specificity of procedural simulator training. METHODS: This was randomized single......), whereas the control group trained on only one procedure (salpingectomy). The main outcomes were number of repetitions and time to proficiency for the second procedure. RESULTS: Ninety-six participants were randomized, of whom 74 per cent were women, with a median age of 26 years. The intervention group...

  12. Generation and Analysis of Constrained Random Sampling Patterns

    DEFF Research Database (Denmark)

    Pierzchlewski, Jacek; Arildsen, Thomas

    2016-01-01

    Random sampling is a technique for signal acquisition which is gaining popularity in practical signal processing systems. Nowadays, event-driven analog-to-digital converters make random sampling feasible in practical applications. A process of random sampling is defined by a sampling pattern, whi...

  13. Sampling procedure for the foliar analysis of deciduous trees

    NARCIS (Netherlands)

    Luyssaert, Sebastiaan; Raitio, Hannu; Vervaeke, Pieter; Mertens, Jan; Lust, Noël

    2002-01-01

    Sampling can be the source of the greatest errors in the overall results of foliar analysis. This paper reviews the variability in heavy metal concentrations in tree crowns, which is a feature that should be known and understood when designing a suitable leaf sampling procedure. The leaf sampling

  14. A Unified Approach to Power Calculation and Sample Size Determination for Random Regression Models

    Science.gov (United States)

    Shieh, Gwowen

    2007-01-01

    The underlying statistical models for multiple regression analysis are typically attributed to two types of modeling: fixed and random. The procedures for calculating power and sample size under the fixed regression models are well known. However, the literature on random regression models is limited and has been confined to the case of all…

  15. Some heuristic procedures for analyzing random vibration of nonlinear oscillators.

    Science.gov (United States)

    Crandall, S. H.

    1971-01-01

    The stationary response of a lightly damped nonlinear oscillator subjected to wideband random excitation can be examined as an example of thermal equilibrium. It may be assumed that the response consists of a series of free-vibration cycles with small random fluctuations in phase and amplitude. Certain statistical properties of the response can be estimated by averaging corresponding properties of the free vibration with respect to cycle amplitude distributions. Such heuristic procedures for determining the expected frequency and the autocorrelation function of the stationary response are outlined. Some additional results concerning first-passage problems for nonlinear oscillators are included.

  16. A random spatial sampling method in a rural developing nation

    Science.gov (United States)

    Michelle C. Kondo; Kent D.W. Bream; Frances K. Barg; Charles C. Branas

    2014-01-01

    Nonrandom sampling of populations in developing nations has limitations and can inaccurately estimate health phenomena, especially among hard-to-reach populations such as rural residents. However, random sampling of rural populations in developing nations can be challenged by incomplete enumeration of the base population. We describe a stratified random sampling method...

  17. Power Spectrum Estimation of Randomly Sampled Signals

    DEFF Research Database (Denmark)

    Velte, Clara M.; Buchhave, Preben; K. George, William

    2014-01-01

    with high data rate and low inherent bias, respectively, while residence time weighting provides non-biased estimates regardless of setting. The free-running processor was also tested and compared to residence time weighting using actual LDA measurements in a turbulent round jet. Power spectra from...... of alternative methods attempting to produce correct power spectra have been invented andtested. The objective of the current study is to create a simple computer generated signal for baseline testing of residence time weighting and some of the most commonly proposed algorithms (or algorithms which most...... modernalgorithms ultimately are based on), sample-and-hold and the direct spectral estimator without residence time weighting, and compare how they perform in relation to power spectra based on the equidistantly sampled reference signal. The computer generated signal is a Poisson process with a sample rate...

  18. Random constraint sampling and duality for convex optimization

    OpenAIRE

    Haskell, William B.; Pengqian, Yu

    2016-01-01

    We are interested in solving convex optimization problems with large numbers of constraints. Randomized algorithms, such as random constraint sampling, have been very successful in giving nearly optimal solutions to such problems. In this paper, we combine random constraint sampling with the classical primal-dual algorithm for convex optimization problems with large numbers of constraints, and we give a convergence rate analysis. We then report numerical experiments that verify the effectiven...

  19. Random number datasets generated from statistical analysis of randomly sampled GSM recharge cards.

    Science.gov (United States)

    Okagbue, Hilary I; Opanuga, Abiodun A; Oguntunde, Pelumi E; Ugwoke, Paulinus O

    2017-02-01

    In this article, a random number of datasets was generated from random samples of used GSM (Global Systems for Mobile Communications) recharge cards. Statistical analyses were performed to refine the raw data to random number datasets arranged in table. A detailed description of the method and relevant tests of randomness were also discussed.

  20. Power Spectrum Estimation of Randomly Sampled Signals

    DEFF Research Database (Denmark)

    Velte, C. M.; Buchhave, P.; K. George, W.

    . Residence time weighting provides non-biased estimates regardless of setting. The free-running processor was also tested and compared to residence time weighting using actual LDA measurements in a turbulent round jet. Power spectra from measurements on the jet centerline and the outer part of the jet...... sine waves. The primary signal and the corresponding power spectrum are shown in Figure 1. The conventional spectrum shows multiple erroneous mixing frequencies and the peak values are too low. The residence time weighted spectrum is correct. The sample-and-hold spectrum has lower power than...... the correct spectrum, and the f -2-filtering effect appearing for low data densities is evident (Adrian and Yao 1987). The remaining tests also show that sample-and-hold and the free-running processor perform well only under very particular circumstances with high data rate and low inherent bias, respectively...

  1. Are most samples of animals systematically biased? Consistent individual trait differences bias samples despite random sampling.

    Science.gov (United States)

    Biro, Peter A

    2013-02-01

    Sampling animals from the wild for study is something nearly every biologist has done, but despite our best efforts to obtain random samples of animals, 'hidden' trait biases may still exist. For example, consistent behavioral traits can affect trappability/catchability, independent of obvious factors such as size and gender, and these traits are often correlated with other repeatable physiological and/or life history traits. If so, systematic sampling bias may exist for any of these traits. The extent to which this is a problem, of course, depends on the magnitude of bias, which is presently unknown because the underlying trait distributions in populations are usually unknown, or unknowable. Indeed, our present knowledge about sampling bias comes from samples (not complete population censuses), which can possess bias to begin with. I had the unique opportunity to create naturalized populations of fish by seeding each of four small fishless lakes with equal densities of slow-, intermediate-, and fast-growing fish. Using sampling methods that are not size-selective, I observed that fast-growing fish were up to two-times more likely to be sampled than slower-growing fish. This indicates substantial and systematic bias with respect to an important life history trait (growth rate). If correlations between behavioral, physiological and life-history traits are as widespread as the literature suggests, then many animal samples may be systematically biased with respect to these traits (e.g., when collecting animals for laboratory use), and affect our inferences about population structure and abundance. I conclude with a discussion on ways to minimize sampling bias for particular physiological/behavioral/life-history types within animal populations.

  2. Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

  3. SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

    Directory of Open Access Journals (Sweden)

    Sampath Sundaram

    2010-09-01

    Full Text Available In this paper an attempt is made to extend linear systematic sampling using multiple random starts due to Gautschi(1957for various types of systematic sampling schemes available in literature, namely(i  Balanced Systematic Sampling (BSS of  Sethi (1965 and (ii Modified Systematic Sampling (MSS of Singh, Jindal, and Garg  (1968. Further, the proposed methods were compared with Yates corrected estimator developed with reference to Gautschi’s Linear systematic sampling (LSS with two random starts using appropriate super population models with the  help of R package for statistical computing.

  4. Efficient sampling of complex network with modified random walk strategies

    Science.gov (United States)

    Xie, Yunya; Chang, Shuhua; Zhang, Zhipeng; Zhang, Mi; Yang, Lei

    2018-02-01

    We present two novel random walk strategies, choosing seed node (CSN) random walk and no-retracing (NR) random walk. Different from the classical random walk sampling, the CSN and NR strategies focus on the influences of the seed node choice and path overlap, respectively. Three random walk samplings are applied in the Erdös-Rényi (ER), Barabási-Albert (BA), Watts-Strogatz (WS), and the weighted USAir networks, respectively. Then, the major properties of sampled subnets, such as sampling efficiency, degree distributions, average degree and average clustering coefficient, are studied. The similar conclusions can be reached with these three random walk strategies. Firstly, the networks with small scales and simple structures are conducive to the sampling. Secondly, the average degree and the average clustering coefficient of the sampled subnet tend to the corresponding values of original networks with limited steps. And thirdly, all the degree distributions of the subnets are slightly biased to the high degree side. However, the NR strategy performs better for the average clustering coefficient of the subnet. In the real weighted USAir networks, some obvious characters like the larger clustering coefficient and the fluctuation of degree distribution are reproduced well by these random walk strategies.

  5. Secondary School Students' Reasoning about Conditional Probability, Samples, and Sampling Procedures

    Science.gov (United States)

    Prodromou, Theodosia

    2016-01-01

    In the Australian mathematics curriculum, Year 12 students (aged 16-17) are asked to solve conditional probability problems that involve the representation of the problem situation with two-way tables or three-dimensional diagrams and consider sampling procedures that result in different correct answers. In a small exploratory study, we…

  6. Spatial Random Sampling: A Structure-Preserving Data Sketching Tool

    Science.gov (United States)

    Rahmani, Mostafa; Atia, George K.

    2017-09-01

    Random column sampling is not guaranteed to yield data sketches that preserve the underlying structures of the data and may not sample sufficiently from less-populated data clusters. Also, adaptive sampling can often provide accurate low rank approximations, yet may fall short of producing descriptive data sketches, especially when the cluster centers are linearly dependent. Motivated by that, this paper introduces a novel randomized column sampling tool dubbed Spatial Random Sampling (SRS), in which data points are sampled based on their proximity to randomly sampled points on the unit sphere. The most compelling feature of SRS is that the corresponding probability of sampling from a given data cluster is proportional to the surface area the cluster occupies on the unit sphere, independently from the size of the cluster population. Although it is fully randomized, SRS is shown to provide descriptive and balanced data representations. The proposed idea addresses a pressing need in data science and holds potential to inspire many novel approaches for analysis of big data.

  7. Methods for sample size determination in cluster randomized trials.

    Science.gov (United States)

    Rutterford, Clare; Copas, Andrew; Eldridge, Sandra

    2015-06-01

    The use of cluster randomized trials (CRTs) is increasing, along with the variety in their design and analysis. The simplest approach for their sample size calculation is to calculate the sample size assuming individual randomization and inflate this by a design effect to account for randomization by cluster. The assumptions of a simple design effect may not always be met; alternative or more complicated approaches are required. We summarise a wide range of sample size methods available for cluster randomized trials. For those familiar with sample size calculations for individually randomized trials but with less experience in the clustered case, this manuscript provides formulae for a wide range of scenarios with associated explanation and recommendations. For those with more experience, comprehensive summaries are provided that allow quick identification of methods for a given design, outcome and analysis method. We present first those methods applicable to the simplest two-arm, parallel group, completely randomized design followed by methods that incorporate deviations from this design such as: variability in cluster sizes; attrition; non-compliance; or the inclusion of baseline covariates or repeated measures. The paper concludes with methods for alternative designs. There is a large amount of methodology available for sample size calculations in CRTs. This paper gives the most comprehensive description of published methodology for sample size calculation and provides an important resource for those designing these trials. © The Author 2015. Published by Oxford University Press on behalf of the International Epidemiological Association.

  8. Optimization by GRASP greedy randomized adaptive search procedures

    CERN Document Server

    Resende, Mauricio G C

    2016-01-01

    This is the first book to cover GRASP (Greedy Randomized Adaptive Search Procedures), a metaheuristic that has enjoyed wide success in practice with a broad range of applications to real-world combinatorial optimization problems. The state-of-the-art coverage and carefully crafted pedagogical style lends this book highly accessible as an introductory text not only to GRASP, but also to combinatorial optimization, greedy algorithms, local search, and path-relinking, as well as to heuristics and metaheuristics, in general. The focus is on algorithmic and computational aspects of applied optimization with GRASP with emphasis given to the end-user, providing sufficient information on the broad spectrum of advances in applied optimization with GRASP. For the more advanced reader, chapters on hybridization with path-relinking and parallel and continuous GRASP present these topics in a clear and concise fashion. Additionally, the book offers a very complete annotated bibliography of GRASP and combinatorial optimizat...

  9. SOME SYSTEMATIC SAMPLING STRATEGIES USING MULTIPLE RANDOM STARTS

    OpenAIRE

    Sampath Sundaram; Ammani Sivaraman

    2010-01-01

    In this paper an attempt is made to extend linear systematic sampling using multiple random starts due to Gautschi(1957)for various types of systematic sampling schemes available in literature, namely(i)  Balanced Systematic Sampling (BSS) of  Sethi (1965) and (ii) Modified Systematic Sampling (MSS) of Singh, Jindal, and Garg  (1968). Further, the proposed methods were compared with Yates corrected estimator developed with reference to Gautschi’s Linear systematic samplin...

  10. Sampling large random knots in a confined space

    Energy Technology Data Exchange (ETDEWEB)

    Arsuaga, J [Department of Mathematics, San Francisco State University, 1600 Holloway Ave, San Francisco, CA 94132 (United States); Blackstone, T [Department of Computer Science, San Francisco State University, 1600 Holloway Ave., San Francisco, CA 94132 (United States); Diao, Y [Department of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Hinson, K [Department of Mathematics and Statistics, University of North Carolina at Charlotte, Charlotte, NC 28223 (United States); Karadayi, E [Department of Mathematics, University of South Florida, 4202 E Fowler Avenue, Tampa, FL 33620 (United States); Saito, M [Department of Mathematics, University of South Florida, 4202 E Fowler Avenue, Tampa, FL 33620 (United States)

    2007-09-28

    DNA knots formed under extreme conditions of condensation, as in bacteriophage P4, are difficult to analyze experimentally and theoretically. In this paper, we propose to use the uniform random polygon model as a supplementary method to the existing methods for generating random knots in confinement. The uniform random polygon model allows us to sample knots with large crossing numbers and also to generate large diagrammatically prime knot diagrams. We show numerically that uniform random polygons sample knots with large minimum crossing numbers and certain complicated knot invariants (as those observed experimentally). We do this in terms of the knot determinants or colorings. Our numerical results suggest that the average determinant of a uniform random polygon of n vertices grows faster than O(e{sup n{sup 2}}). We also investigate the complexity of prime knot diagrams. We show rigorously that the probability that a randomly selected 2D uniform random polygon of n vertices is almost diagrammatically prime goes to 1 as n goes to infinity. Furthermore, the average number of crossings in such a diagram is at the order of O(n{sup 2}). Therefore, the two-dimensional uniform random polygons offer an effective way in sampling large (prime) knots, which can be useful in various applications.

  11. A New Stratified Sampling Procedure which Decreases Error Estimation of Varroa Mite Number on Sticky Boards.

    Science.gov (United States)

    Kretzschmar, A; Durand, E; Maisonnasse, A; Vallon, J; Le Conte, Y

    2015-06-01

    A new procedure of stratified sampling is proposed in order to establish an accurate estimation of Varroa destructor populations on sticky bottom boards of the hive. It is based on the spatial sampling theory that recommends using regular grid stratification in the case of spatially structured process. The distribution of varroa mites on sticky board being observed as spatially structured, we designed a sampling scheme based on a regular grid with circles centered on each grid element. This new procedure is then compared with a former method using partially random sampling. Relative error improvements are exposed on the basis of a large sample of simulated sticky boards (n=20,000) which provides a complete range of spatial structures, from a random structure to a highly frame driven structure. The improvement of varroa mite number estimation is then measured by the percentage of counts with an error greater than a given level. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  12. Sequential time interleaved random equivalent sampling for repetitive signal

    Science.gov (United States)

    Zhao, Yijiu; Liu, Jingjing

    2016-12-01

    Compressed sensing (CS) based sampling techniques exhibit many advantages over other existing approaches for sparse signal spectrum sensing; they are also incorporated into non-uniform sampling signal reconstruction to improve the efficiency, such as random equivalent sampling (RES). However, in CS based RES, only one sample of each acquisition is considered in the signal reconstruction stage, and it will result in more acquisition runs and longer sampling time. In this paper, a sampling sequence is taken in each RES acquisition run, and the corresponding block measurement matrix is constructed using a Whittaker-Shannon interpolation formula. All the block matrices are combined into an equivalent measurement matrix with respect to all sampling sequences. We implemented the proposed approach with a multi-cores analog-to-digital converter (ADC), whose ADC cores are time interleaved. A prototype realization of this proposed CS based sequential random equivalent sampling method has been developed. It is able to capture an analog waveform at an equivalent sampling rate of 40 GHz while sampled at 1 GHz physically. Experiments indicate that, for a sparse signal, the proposed CS based sequential random equivalent sampling exhibits high efficiency.

  13. Optimum allocation in multivariate stratified random sampling: Stochastic matrix optimisation

    OpenAIRE

    Diaz-Garcia, Jose A.; Ramos-Quiroga, Rogelio

    2011-01-01

    The allocation problem for multivariate stratified random sampling as a problem of stochastic matrix integer mathematical programming is considered. With these aims the asymptotic normality of sample covariance matrices for each strata is established. Some alternative approaches are suggested for its solution. An example is solved by applying the proposed techniques.

  14. Performance of Random Effects Model Estimators under Complex Sampling Designs

    Science.gov (United States)

    Jia, Yue; Stokes, Lynne; Harris, Ian; Wang, Yan

    2011-01-01

    In this article, we consider estimation of parameters of random effects models from samples collected via complex multistage designs. Incorporation of sampling weights is one way to reduce estimation bias due to unequal probabilities of selection. Several weighting methods have been proposed in the literature for estimating the parameters of…

  15. A random spatial sampling method in a rural developing nation.

    Science.gov (United States)

    Kondo, Michelle C; Bream, Kent D W; Barg, Frances K; Branas, Charles C

    2014-04-10

    Nonrandom sampling of populations in developing nations has limitations and can inaccurately estimate health phenomena, especially among hard-to-reach populations such as rural residents. However, random sampling of rural populations in developing nations can be challenged by incomplete enumeration of the base population. We describe a stratified random sampling method using geographical information system (GIS) software and global positioning system (GPS) technology for application in a health survey in a rural region of Guatemala, as well as a qualitative study of the enumeration process. This method offers an alternative sampling technique that could reduce opportunities for bias in household selection compared to cluster methods. However, its use is subject to issues surrounding survey preparation, technological limitations and in-the-field household selection. Application of this method in remote areas will raise challenges surrounding the boundary delineation process, use and translation of satellite imagery between GIS and GPS, and household selection at each survey point in varying field conditions. This method favors household selection in denser urban areas and in new residential developments. Random spatial sampling methodology can be used to survey a random sample of population in a remote region of a developing nation. Although this method should be further validated and compared with more established methods to determine its utility in social survey applications, it shows promise for use in developing nations with resource-challenged environments where detailed geographic and human census data are less available.

  16. Sample Selection in Randomized Experiments: A New Method Using Propensity Score Stratified Sampling

    Science.gov (United States)

    Tipton, Elizabeth; Hedges, Larry; Vaden-Kiernan, Michael; Borman, Geoffrey; Sullivan, Kate; Caverly, Sarah

    2014-01-01

    Randomized experiments are often seen as the "gold standard" for causal research. Despite the fact that experiments use random assignment to treatment conditions, units are seldom selected into the experiment using probability sampling. Very little research on experimental design has focused on how to make generalizations to well-defined…

  17. Random sampling and validation of covariance matrices of resonance parameters

    Science.gov (United States)

    Plevnik, Lucijan; Zerovnik, Gašper

    2017-09-01

    Analytically exact methods for random sampling of arbitrary correlated parameters are presented. Emphasis is given on one hand on the possible inconsistencies in the covariance data, concentrating on the positive semi-definiteness and consistent sampling of correlated inherently positive parameters, and on the other hand on optimization of the implementation of the methods itself. The methods have been applied in the program ENDSAM, written in the Fortran language, which from a file from a nuclear data library of a chosen isotope in ENDF-6 format produces an arbitrary number of new files in ENDF-6 format which contain values of random samples of resonance parameters (in accordance with corresponding covariance matrices) in places of original values. The source code for the program ENDSAM is available from the OECD/NEA Data Bank. The program works in the following steps: reads resonance parameters and their covariance data from nuclear data library, checks whether the covariance data is consistent, and produces random samples of resonance parameters. The code has been validated with both realistic and artificial data to show that the produced samples are statistically consistent. Additionally, the code was used to validate covariance data in existing nuclear data libraries. A list of inconsistencies, observed in covariance data of resonance parameters in ENDF-VII.1, JEFF-3.2 and JENDL-4.0 is presented. For now, the work has been limited to resonance parameters, however the methods presented are general and can in principle be extended to sampling and validation of any nuclear data.

  18. Generalized and synthetic regression estimators for randomized branch sampling

    Science.gov (United States)

    David L. R. Affleck; Timothy G. Gregoire

    2015-01-01

    In felled-tree studies, ratio and regression estimators are commonly used to convert more readily measured branch characteristics to dry crown mass estimates. In some cases, data from multiple trees are pooled to form these estimates. This research evaluates the utility of both tactics in the estimation of crown biomass following randomized branch sampling (...

  19. Effective sampling of random surfaces by baby universe surgery

    NARCIS (Netherlands)

    Ambjørn, J.; Białas, P.; Jurkiewicz, J.; Burda, Z.; Petersson, B.

    1994-01-01

    We propose a new, very efficient algorithm for sampling of random surfaces in the Monte Carlo simulations, based on so-called baby universe surgery, i.e. cutting and pasting of baby universe. It drastically reduces slowing down as compared to the standard local flip algorithm, thereby allowing

  20. Stratified random sampling plan for an irrigation customer telephone survey

    Energy Technology Data Exchange (ETDEWEB)

    Johnston, J.W.; Davis, L.J.

    1986-05-01

    This report describes the procedures used to design and select a sample for a telephone survey of individuals who use electricity in irrigating agricultural cropland in the Pacific Northwest. The survey is intended to gather information on the irrigated agricultural sector that will be useful for conservation assessment, load forecasting, rate design, and other regional power planning activities.

  1. Random Walks on Directed Networks: Inference and Respondent-driven Sampling

    CERN Document Server

    Malmros, Jens; Britton, Tom

    2013-01-01

    Respondent driven sampling (RDS) is a method often used to estimate population properties (e.g. sexual risk behavior) in hard-to-reach populations. It combines an effective modified snowball sampling methodology with an estimation procedure that yields unbiased population estimates under the assumption that the sampling process behaves like a random walk on the social network of the population. Current RDS estimation methodology assumes that the social network is undirected, i.e. that all edges are reciprocal. However, empirical social networks in general also have non-reciprocated edges. To account for this fact, we develop a new estimation method for RDS in the presence of directed edges on the basis of random walks on directed networks. We distinguish directed and undirected edges and consider the possibility that the random walk returns to its current position in two steps through an undirected edge. We derive estimators of the selection probabilities of individuals as a function of the number of outgoing...

  2. 7 CFR 52.38 - Sampling plans and procedures for determining lot compliance.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Sampling plans and procedures for determining lot... Sampling § 52.38 Sampling plans and procedures for determining lot compliance. (a) Except as otherwise... Administrator, samples shall be selected from each lot in the exact number of sample units indicated for the lot...

  3. Random sampling and validation of covariance matrices of resonance parameters

    Directory of Open Access Journals (Sweden)

    Plevnik Lucijan

    2017-01-01

    Full Text Available Analytically exact methods for random sampling of arbitrary correlated parameters are presented. Emphasis is given on one hand on the possible inconsistencies in the covariance data, concentrating on the positive semi-definiteness and consistent sampling of correlated inherently positive parameters, and on the other hand on optimization of the implementation of the methods itself. The methods have been applied in the program ENDSAM, written in the Fortran language, which from a file from a nuclear data library of a chosen isotope in ENDF-6 format produces an arbitrary number of new files in ENDF-6 format which contain values of random samples of resonance parameters (in accordance with corresponding covariance matrices in places of original values. The source code for the program ENDSAM is available from the OECD/NEA Data Bank. The program works in the following steps: reads resonance parameters and their covariance data from nuclear data library, checks whether the covariance data is consistent, and produces random samples of resonance parameters. The code has been validated with both realistic and artificial data to show that the produced samples are statistically consistent. Additionally, the code was used to validate covariance data in existing nuclear data libraries. A list of inconsistencies, observed in covariance data of resonance parameters in ENDF-VII.1, JEFF-3.2 and JENDL-4.0 is presented. For now, the work has been limited to resonance parameters, however the methods presented are general and can in principle be extended to sampling and validation of any nuclear data.

  4. Implementation guide for turbidity threshold sampling: principles, procedures, and analysis

    Science.gov (United States)

    Jack Lewis; Rand Eads

    2009-01-01

    Turbidity Threshold Sampling uses real-time turbidity and river stage information to automatically collect water quality samples for estimating suspended sediment loads. The system uses a programmable data logger in conjunction with a stage measurement device, a turbidity sensor, and a pumping sampler. Specialized software enables the user to control the sampling...

  5. Random analysis of bearing capacity of square footing using the LAS procedure

    Directory of Open Access Journals (Sweden)

    Kawa Marek

    2016-09-01

    Full Text Available In the present paper, a three-dimensional problem of bearing capacity of square footing on random soil medium is analyzed. The random fields of strength parameters c and φ are generated using LAS procedure (Local Average Subdivision, Fenton and Vanmarcke 1990. The procedure used is re-implemented by the authors in Mathematica environment in order to combine it with commercial program. Since the procedure is still tested the random filed has been assumed as one-dimensional: the strength properties of soil are random in vertical direction only.

  6. SNP selection and classification of genome-wide SNP data using stratified sampling random forests.

    Science.gov (United States)

    Wu, Qingyao; Ye, Yunming; Liu, Yang; Ng, Michael K

    2012-09-01

    For high dimensional genome-wide association (GWA) case-control data of complex disease, there are usually a large portion of single-nucleotide polymorphisms (SNPs) that are irrelevant with the disease. A simple random sampling method in random forest using default mtry parameter to choose feature subspace, will select too many subspaces without informative SNPs. Exhaustive searching an optimal mtry is often required in order to include useful and relevant SNPs and get rid of vast of non-informative SNPs. However, it is too time-consuming and not favorable in GWA for high-dimensional data. The main aim of this paper is to propose a stratified sampling method for feature subspace selection to generate decision trees in a random forest for GWA high-dimensional data. Our idea is to design an equal-width discretization scheme for informativeness to divide SNPs into multiple groups. In feature subspace selection, we randomly select the same number of SNPs from each group and combine them to form a subspace to generate a decision tree. The advantage of this stratified sampling procedure can make sure each subspace contains enough useful SNPs, but can avoid a very high computational cost of exhaustive search of an optimal mtry, and maintain the randomness of a random forest. We employ two genome-wide SNP data sets (Parkinson case-control data comprised of 408 803 SNPs and Alzheimer case-control data comprised of 380 157 SNPs) to demonstrate that the proposed stratified sampling method is effective, and it can generate better random forest with higher accuracy and lower error bound than those by Breiman's random forest generation method. For Parkinson data, we also show some interesting genes identified by the method, which may be associated with neurological disorders for further biological investigations.

  7. 40 CFR 87.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.82 Sampling and analytical procedures for measuring smoke exhaust emissions. The system and procedures for sampling and...

  8. The Effectiveness of Two Grammar Treatment Procedures for Children with SLI: A Randomized Clinical Trial

    Science.gov (United States)

    Smith-Lock, Karen M.; Leitão, Suze; Prior, Polly; Nickels, Lyndsey

    2015-01-01

    Purpose: This study compared the effectiveness of two grammar treatment procedures for children with specific language impairment. Method: A double-blind superiority trial with cluster randomization was used to compare a cueing procedure, designed to elicit a correct production following an initial error, to a recasting procedure, which required…

  9. Sampling procedure for lake or stream surface water chemistry

    Science.gov (United States)

    Robert Musselman

    2012-01-01

    Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

  10. Sampling Polymorphs of Ionic Solids using Random Superlattices.

    Science.gov (United States)

    Stevanović, Vladan

    2016-02-19

    Polymorphism offers rich and virtually unexplored space for discovering novel functional materials. To harness this potential approaches capable of both exploring the space of polymorphs and assessing their realizability are needed. One such approach devised for partially ionic solids is presented. The structure prediction part is carried out by performing local density functional theory relaxations on a large set of random supperlattices (RSLs) with atoms distributed randomly over different planes in a way that favors cation-anion coordination. Applying the RSL sampling on MgO, ZnO, and SnO_{2} reveals that the resulting probability of occurrence of a given structure offers a measure of its realizability explaining fully the experimentally observed, metastable polymorphs in these three systems.

  11. Analysis of a global random stratified sample of nurse legislation.

    Science.gov (United States)

    Benton, D C; Fernández-Fernández, M P; González-Jurado, M A; Beneit-Montesinos, J V

    2015-06-01

    To identify, compare and contrast the major component parts of heterogeneous stratified sample of nursing legislation. Nursing legislation varies from one jurisdiction to another. Up until now no research exists into whether the variations of such legislation are random or if variations are related to a set of key attributes. This mixed method study used a random stratified sample of legislation to map through documentary analysis the content of 14 nursing acts and then explored, using quantitative techniques, whether the material contained relates to a number of key attributes. These attributes include: legal tradition of the jurisdiction; model of regulation; administrative approach; area of the world; and the economic status of the jurisdiction. Twelve component parts of nursing legislation were identified. These were remarkably similar irrespective of attributes of interest. However, not all component parts were specified in the same level of detail and the manner by which the elements were addressed did vary. A number of potential relationships between the structure of the legislation and the key attributes of interest were identified. This study generated a comprehensive and integrated map of a global sample of nursing legislation. It provides a set of descriptors to be used to undertake further quantitative work and provides an important policy tool to facilitate dialogue between regulatory bodies. At the individual nurse level it offers insights that can help nurses pursue recognition of credentials across jurisdictions. © 2015 International Council of Nurses.

  12. Influence of Sampling Procedure on Codeine Concentrations in Oral Fluid.

    Science.gov (United States)

    Coucke, Line D; De Smet, Lien; Verstraete, Alain G

    2016-03-01

    For many drugs, there is a poor correlation between the plasma and oral fluid (OF) concentrations, due to differences in OF pH, oral contamination, stimulation of OF flow and variability of the volume of sample taken. The aim of this study was to evaluate the OF/plasma ratio and variability in drug concentration in OF sampled by two commercially available collection systems: Saliva Collection System (SCS) and Quantisal. Blood and OF samples were collected from 12 volunteers after intake of 19.5 mg codeine phosphate. Six persons were sampled by SCS first, followed by Quantisal; six other participants used Quantisal before SCS. The OF content of SCS tubes was measured spectrophotometrically. The Quantisal devices were weighed to correct for the effectively obtained OF volume. Codeine was measured by gas chromatography-mass spectrometry. The mean codeine concentration at 1 h was 29.8 ± 18.8 μg/L in plasma, 72.8 ± 63.9 μg/L in SCS OF and 85.3 ± 72.6 μg/L in Quantisal OF. The mean OF/plasma ratio was 2.30 ± 0.77 (SCS) and 2.69 ± 1.94 (Quantisal). Pearson's correlation coefficient between OF and plasma codeine concentrations was statistically significantly (P = 0.005) higher for SCS (R(2) = 0.745) than for Quantisal (R(2) = 0.403). The variability in ratios with Quantisal was markedly reduced when used after SCS. Codeine concentrations measured in OF taken with SCS correlate better with plasma concentrations than in OF obtained with Quantisal, particularly when Quantisal was used first. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  13. Modular approach to customise sample preparation procedures for viral metagenomics: a reproducible protocol for virome analysis.

    Science.gov (United States)

    Conceição-Neto, Nádia; Zeller, Mark; Lefrère, Hanne; De Bruyn, Pieter; Beller, Leen; Deboutte, Ward; Yinda, Claude Kwe; Lavigne, Rob; Maes, Piet; Van Ranst, Marc; Heylen, Elisabeth; Matthijnssens, Jelle

    2015-11-12

    A major limitation for better understanding the role of the human gut virome in health and disease is the lack of validated methods that allow high throughput virome analysis. To overcome this, we evaluated the quantitative effect of homogenisation, centrifugation, filtration, chloroform treatment and random amplification on a mock-virome (containing nine highly diverse viruses) and a bacterial mock-community (containing four faecal bacterial species) using quantitative PCR and next-generation sequencing. This resulted in an optimised protocol that was able to recover all viruses present in the mock-virome and strongly alters the ratio of viral versus bacterial and 16S rRNA genetic material in favour of viruses (from 43.2% to 96.7% viral reads and from 47.6% to 0.19% bacterial reads). Furthermore, our study indicated that most of the currently used virome protocols, using small filter pores and/or stringent centrifugation conditions may have largely overlooked large viruses present in viromes. We propose NetoVIR (Novel enrichment technique of VIRomes), which allows for a fast, reproducible and high throughput sample preparation for viral metagenomics studies, introducing minimal bias. This procedure is optimised mainly for faecal samples, but with appropriate concentration steps can also be used for other sample types with lower initial viral loads.

  14. Randomly Sampled-Data Control Systems. Ph.D. Thesis

    Science.gov (United States)

    Han, Kuoruey

    1990-01-01

    The purpose is to solve the Linear Quadratic Regulator (LQR) problem with random time sampling. Such a sampling scheme may arise from imperfect instrumentation as in the case of sampling jitter. It can also model the stochastic information exchange among decentralized controllers to name just a few. A practical suboptimal controller is proposed with the nice property of mean square stability. The proposed controller is suboptimal in the sense that the control structure is limited to be linear. Because of i. i. d. assumption, this does not seem unreasonable. Once the control structure is fixed, the stochastic discrete optimal control problem is transformed into an equivalent deterministic optimal control problem with dynamics described by the matrix difference equation. The N-horizon control problem is solved using the Lagrange's multiplier method. The infinite horizon control problem is formulated as a classical minimization problem. Assuming existence of solution to the minimization problem, the total system is shown to be mean square stable under certain observability conditions. Computer simulations are performed to illustrate these conditions.

  15. Procedures for cryogenic X-ray ptychographic imaging of biological samples.

    Science.gov (United States)

    Yusuf, M; Zhang, F; Chen, B; Bhartiya, A; Cunnea, K; Wagner, U; Cacho-Nerin, F; Schwenke, J; Robinson, I K

    2017-03-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  16. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    Directory of Open Access Journals (Sweden)

    M. Yusuf

    2017-03-01

    Full Text Available Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  17. A Table-Based Random Sampling Simulation for Bioluminescence Tomography

    Directory of Open Access Journals (Sweden)

    Xiaomeng Zhang

    2006-01-01

    Full Text Available As a popular simulation of photon propagation in turbid media, the main problem of Monte Carlo (MC method is its cumbersome computation. In this work a table-based random sampling simulation (TBRS is proposed. The key idea of TBRS is to simplify multisteps of scattering to a single-step process, through randomly table querying, thus greatly reducing the computing complexity of the conventional MC algorithm and expediting the computation. The TBRS simulation is a fast algorithm of the conventional MC simulation of photon propagation. It retained the merits of flexibility and accuracy of conventional MC method and adapted well to complex geometric media and various source shapes. Both MC simulations were conducted in a homogeneous medium in our work. Also, we present a reconstructing approach to estimate the position of the fluorescent source based on the trial-and-error theory as a validation of the TBRS algorithm. Good agreement is found between the conventional MC simulation and the TBRS simulation.

  18. Random sampling for a mental health survey in a deprived multi-ethnic area of Berlin.

    Science.gov (United States)

    Mundt, Adrian P; Aichberger, Marion C; Kliewe, Thomas; Ignatyev, Yuriy; Yayla, Seda; Heimann, Hannah; Schouler-Ocak, Meryam; Busch, Markus; Rapp, Michael; Heinz, Andreas; Ströhle, Andreas

    2012-12-01

    The aim of the study was to assess the response to random sampling for a mental health survey in a deprived multi-ethnic area of Berlin, Germany, with a large Turkish-speaking population. A random list from the registration office with 1,000 persons stratified by age and gender was retrieved from the population registry and these persons were contacted using a three-stage design including written information, telephone calls and personal contact at home. A female bilingual interviewer contacted persons with Turkish names. Of the persons on the list, 202 were not living in the area, one was deceased, 502 did not respond. Of the 295 responders, 152 explicitly refused(51.5%) to participate. We retained a sample of 143 participants(48.5%) representing the rate of multi-ethnicity in the area (52.1% migrants in the sample vs. 53.5% in the population). Turkish migrants were over-represented(28.9% in the sample vs. 18.6% in the population). Polish migrants (2.1 vs. 5.3% in the population) and persons from the former Yugoslavia (1.4 vs. 4.8% in the population)were under-represented. Bilingual contact procedures can improve the response rates of the most common migrant populations to random sampling if migrants of the same origin gate the contact. High non-contact and non-response rates for migrant and non-migrant populations in deprived urban areas remain a challenge for obtaining representative random samples.

  19. Accounting for Sampling Error in Genetic Eigenvalues Using Random Matrix Theory.

    Science.gov (United States)

    Sztepanacz, Jacqueline L; Blows, Mark W

    2017-07-01

    The distribution of genetic variance in multivariate phenotypes is characterized by the empirical spectral distribution of the eigenvalues of the genetic covariance matrix. Empirical estimates of genetic eigenvalues from random effects linear models are known to be overdispersed by sampling error, where large eigenvalues are biased upward, and small eigenvalues are biased downward. The overdispersion of the leading eigenvalues of sample covariance matrices have been demonstrated to conform to the Tracy-Widom (TW) distribution. Here we show that genetic eigenvalues estimated using restricted maximum likelihood (REML) in a multivariate random effects model with an unconstrained genetic covariance structure will also conform to the TW distribution after empirical scaling and centering. However, where estimation procedures using either REML or MCMC impose boundary constraints, the resulting genetic eigenvalues tend not be TW distributed. We show how using confidence intervals from sampling distributions of genetic eigenvalues without reference to the TW distribution is insufficient protection against mistaking sampling error as genetic variance, particularly when eigenvalues are small. By scaling such sampling distributions to the appropriate TW distribution, the critical value of the TW statistic can be used to determine if the magnitude of a genetic eigenvalue exceeds the sampling error for each eigenvalue in the spectral distribution of a given genetic covariance matrix. Copyright © 2017 by the Genetics Society of America.

  20. A comparison of methods for representing sparsely sampled random quantities.

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vicente Jose; Swiler, Laura Painton; Urbina, Angel; Mullins, Joshua

    2013-09-01

    This report discusses the treatment of uncertainties stemming from relatively few samples of random quantities. The importance of this topic extends beyond experimental data uncertainty to situations involving uncertainty in model calibration, validation, and prediction. With very sparse data samples it is not practical to have a goal of accurately estimating the underlying probability density function (PDF). Rather, a pragmatic goal is that the uncertainty representation should be conservative so as to bound a specified percentile range of the actual PDF, say the range between 0.025 and .975 percentiles, with reasonable reliability. A second, opposing objective is that the representation not be overly conservative; that it minimally over-estimate the desired percentile range of the actual PDF. The presence of the two opposing objectives makes the sparse-data uncertainty representation problem interesting and difficult. In this report, five uncertainty representation techniques are characterized for their performance on twenty-one test problems (over thousands of trials for each problem) according to these two opposing objectives and other performance measures. Two of the methods, statistical Tolerance Intervals and a kernel density approach specifically developed for handling sparse data, exhibit significantly better overall performance than the others.

  1. Randomization in laboratory procedure is key to obtaining reproducible microarray results.

    Directory of Open Access Journals (Sweden)

    Hyuna Yang

    Full Text Available The quality of gene expression microarray data has improved dramatically since the first arrays were introduced in the late 1990s. However, the reproducibility of data generated at multiple laboratory sites remains a matter of concern, especially for scientists who are attempting to combine and analyze data from public repositories. We have carried out a study in which a common set of RNA samples was assayed five times in four different laboratories using Affymetrix GeneChip arrays. We observed dramatic differences in the results across laboratories and identified batch effects in array processing as one of the primary causes for these differences. When batch processing of samples is confounded with experimental factors of interest it is not possible to separate their effects, and lists of differentially expressed genes may include many artifacts. This study demonstrates the substantial impact of sample processing on microarray analysis results and underscores the need for randomization in the laboratory as a means to avoid confounding of biological factors with procedural effects.

  2. Random analysis of bearing capacity of square footing using the LAS procedure

    Science.gov (United States)

    Kawa, Marek; Puła, Wojciech; Suska, Michał

    2016-09-01

    In the present paper, a three-dimensional problem of bearing capacity of square footing on random soil medium is analyzed. The random fields of strength parameters c and φ are generated using LAS procedure (Local Average Subdivision, Fenton and Vanmarcke 1990). The procedure used is re-implemented by the authors in Mathematica environment in order to combine it with commercial program. Since the procedure is still tested the random filed has been assumed as one-dimensional: the strength properties of soil are random in vertical direction only. Individual realizations of bearing capacity boundary-problem with strength parameters of medium defined the above procedure are solved using FLAC3D Software. The analysis is performed for two qualitatively different cases, namely for the purely cohesive and cohesive-frictional soils. For the latter case the friction angle and cohesion have been assumed as independent random variables. For these two cases the random square footing bearing capacity results have been obtained for the range of fluctuation scales from 0.5 m to 10 m. Each time 1000 Monte Carlo realizations have been performed. The obtained results allow not only the mean and variance but also the probability density function to be estimated. An example of application of this function for reliability calculation has been presented in the final part of the paper.

  3. Analytical procedures for determining Pb and Sr isotopic compositions in water samples by ID-TIMS

    Directory of Open Access Journals (Sweden)

    Veridiana Martins

    2008-01-01

    Full Text Available Few articles deal with lead and strontium isotopic analysis of water samples. The aim of this study was to define the chemical procedures for Pb and Sr isotopic analyses of groundwater samples from an urban sedimentary aquifer. Thirty lead and fourteen strontium isotopic analyses were performed to test different analytical procedures. Pb and Sr isotopic ratios as well as Sr concentration did not vary using different chemical procedures. However, the Pb concentrations were very dependent on the different procedures. Therefore, the choice of the best analytical procedure was based on the Pb results, which indicated a higher reproducibility from samples that had been filtered and acidified before the evaporation, had their residues totally dissolved, and were purified by ion chromatography using the Biorad® column. Our results showed no changes in Pb ratios with the storage time.

  4. On the assessment of extremely low breakdown probabilities by an inverse sampling procedure [gaseous insulation

    DEFF Research Database (Denmark)

    Thyregod, Poul; Vibholm, Svend

    1991-01-01

    the flashover probability function and the corresponding distribution of first breakdown voltages under the inverse sampling procedure, and show how this relation may be utilized to assess the single-shot flashover probability corresponding to the observed average first breakdown voltage. Since the procedure...

  5. 40 CFR 87.64 - Sampling and analytical procedures for measuring gaseous exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.64 Sampling and analytical procedures for measuring gaseous exhaust emissions. (a) The system and...

  6. Empirical aspects about Heckman Procedure Application: Is there sample selection bias in the Brazilian Industry

    OpenAIRE

    Flávio Kaue Fiuza-Moura; Katy Maia

    2015-01-01

    There are several labor market researches whose main goal is to analyze the probability of employment and the structure of wage determination and, for empirical purposes, most of these researches deploy Heckman sample selection bias hazard detection and correction procedure. However, few Brazilian studies are focused in this procedure applicability, especially concerning specific industries. This paper aims to approach these issues by testing the existence of sample selection bias in Brazilia...

  7. An improved stool concentration procedure for the detection of Cryptosporidium oocysts in Orang Asli stool samples.

    Science.gov (United States)

    Salleh, Fatmah Md; Moktar, Norhayati; Yasin, Azlin Mohd; Al-Mekhlafi, Hesham M; Anuar, Tengku Shahrul

    2014-11-01

    To improve the stool concentration procedure, we modified different steps of the standard formalin-ether concentration technique and evaluated these modifications by examining stool samples collected in the field. Seven samples were found positive by the modified formalin-ether concentration technique (M-FECT). Therefore, the M-FECT procedure provides enhanced detection of Cryptosporidium oocysts. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Delineating sampling procedures: Pedagogical significance of analysing sampling descriptions and their justifications in TESL experimental research reports

    Directory of Open Access Journals (Sweden)

    Jason Miin-Hwa Lim

    2011-04-01

    Full Text Available Teaching second language learners how to write research reports constitutes a crucial component in programmes on English for Specific Purposes (ESP in institutions of higher learning. One of the rhetorical segments in research reports that merit attention has to do with the descriptions and justifications of sampling procedures. This genre-based study looks into sampling delineations in the Method-related sections of research articles on the teaching of English as a second language (TESL written by expert writers and published in eight reputed international refereed journals. Using Swales’s (1990 & 2004 framework, I conducted a quantitative analysis of the rhetorical steps and a qualitative investigation into the language resources employed in delineating sampling procedures. This investigation has considerable relevance to ESP students and instructors as it has yielded pertinent findings on how samples can be appropriately described to meet the expectations of dissertation examiners, reviewers, and supervisors. The findings of this study have furnished insights into how supervisors and instructors can possibly teach novice writers ways of using specific linguistic mechanisms to lucidly describe and convincingly justify the sampling procedures in the Method sections of experimental research reports.

  9. 77 FR 58804 - Testing of Product Samples for Listeria monocytogenes: Changes in Procedures

    Science.gov (United States)

    2012-09-24

    ... Food Safety and Inspection Service Testing of Product Samples for Listeria monocytogenes: Changes in... Inspection Service (FSIS) is announcing changes in procedures for Listeria (L.) monocytogenes product... products for laboratory analysis (21 U.S.C. 642(a) and 460(b)). RTE Sampling Programs for Listeria...

  10. 40 CFR 61.207 - Radium-226 sampling and measurement procedures.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Radium-226 sampling and measurement... for Radon Emissions From Phosphogypsum Stacks § 61.207 Radium-226 sampling and measurement procedures... § 61.206, the owner or operator of a phosphogypsum stack shall measure the average radium-226...

  11. 50 CFR 260.61 - Sampling plans and procedures for determining lot compliance.

    Science.gov (United States)

    2010-10-01

    ... determining lot compliance. 260.61 Section 260.61 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE... Sampling plans and procedures for determining lot compliance. (a) Except as otherwise provided for in this... shall be selected from each lot in the exact number of sample units indicated for the lot size in the...

  12. Aromatherapy for reducing colonoscopy related procedural anxiety and physiological parameters: a randomized controlled study.

    Science.gov (United States)

    Hu, Pei-Hsin; Peng, Yen-Chun; Lin, Yu-Ting; Chang, Chi-Sen; Ou, Ming-Chiu

    2010-01-01

    Colonoscopy is generally tolerated, some patients regarding the procedure as unpleasant and painful and generally performed with the patient sedated and receiving analgesics. The effect of sedation and analgesia for colonoscopy is limited. Aromatherapy is also applied to gastrointestinal endoscopy to reduce procedural anxiety. There is lack of information about aromatherapy specific for colonoscopy. In this study, we aimed to performed a randomized controlled study to investigate the effect of aromatherapy on relieve anxiety, stress and physiological parameters of colonoscopy. A randomized controlled trail was carried out and collected in 2009 and 2010. The participants were randomized in two groups. Aromatherapy was then carried out by inhalation of Sunflower oil (control group) and Neroli oil (Experimental group). The anxiety index was evaluated by State Trait Anxiety Inventory-state (STAI-S) score before aromatherapy and after colonoscopy as well as the pain index for post-procedural by visual analogue scale (VAS). Physiological indicators, such as blood pressure (systolic and diastolic blood pressure), heart rate and respiratory rate were evaluated before and after aromatherapy. Participates in this study were 27 subjects, 13 in control group and 14 in Neroli group with average age 52.26 +/- 17.79 years. There was no significance of procedural anxiety by STAI-S score and procedural pain by VAS. The physiological parameters showed a significant lower pre- and post-procedural systolic blood pressure in Neroli group than control group. Aromatic care for colonoscopy, although with no significant effect on procedural anxiety, is an inexpensive, effective and safe pre-procedural technique that could decrease systolic blood pressure.

  13. A recommended procedure for establishing the source level relationships between heroin case samples of unknown origins

    Directory of Open Access Journals (Sweden)

    Kar-Weng Chan

    2014-06-01

    Full Text Available A recent concern of how to reliably establish the source level relationships of heroin case samples is addressed in this paper. Twenty-two trafficking heroin case samples of unknown origins seized from two major regions (Kuala Lumpur and Penang in Malaysia were studied. A procedure containing six major steps was followed to analyze and classify these samples. Subsequently, with the aid of statistical control samples, reliability of the clustering result was assessed. The final outcome reveals that the samples seized from the two regions in 2013 had highly likely originated from two different sources. Hence, the six-step procedure is sufficient for any chemist who attempts to assess the relative source level relationships of heroin samples.

  14. A Combined Weighting Method Based on Hybrid of Interval Evidence Fusion and Random Sampling

    Directory of Open Access Journals (Sweden)

    Ying Yan

    2017-01-01

    Full Text Available Due to the complexity of system and lack of expertise, epistemic uncertainties may present in the experts’ judgment on the importance of certain indices during group decision-making. A novel combination weighting method is proposed to solve the index weighting problem when various uncertainties are present in expert comments. Based on the idea of evidence theory, various types of uncertain evaluation information are uniformly expressed through interval evidence structures. Similarity matrix between interval evidences is constructed, and expert’s information is fused. Comment grades are quantified using the interval number, and cumulative probability function for evaluating the importance of indices is constructed based on the fused information. Finally, index weights are obtained by Monte Carlo random sampling. The method can process expert’s information with varying degrees of uncertainties, which possesses good compatibility. Difficulty in effectively fusing high-conflict group decision-making information and large information loss after fusion is avertible. Original expert judgments are retained rather objectively throughout the processing procedure. Cumulative probability function constructing and random sampling processes do not require any human intervention or judgment. It can be implemented by computer programs easily, thus having an apparent advantage in evaluation practices of fairly huge index systems.

  15. Sample size calculations for 3-level cluster randomized trials

    NARCIS (Netherlands)

    Teerenstra, S.; Moerbeek, M.; Achterberg, T. van; Pelzer, B.J.; Borm, G.F.

    2008-01-01

    BACKGROUND: The first applications of cluster randomized trials with three instead of two levels are beginning to appear in health research, for instance, in trials where different strategies to implement best-practice guidelines are compared. In such trials, the strategy is implemented in health

  16. Sample size calculations for 3-level cluster randomized trials

    NARCIS (Netherlands)

    Teerenstra, S.; Moerbeek, M.; Achterberg, T. van; Pelzer, B.J.; Borm, G.F.

    2008-01-01

    Background The first applications of cluster randomized trials with three instead of two levels are beginning to appear in health research, for instance, in trials where different strategies to implement best-practice guidelines are compared. In such trials, the strategy is implemented in health

  17. Improved estimator of finite population mean using auxiliary attribute in stratified random sampling

    OpenAIRE

    Verma, Hemant K.; Sharma, Prayas; Singh, Rajesh

    2014-01-01

    The present study discuss the problem of estimating the finite population mean using auxiliary attribute in stratified random sampling. In this paper taking the advantage of point bi-serial correlation between the study variable and auxiliary attribute, we have improved the estimation of population mean in stratified random sampling. The expressions for Bias and Mean square error have been derived under stratified random sampling. In addition, an empirical study has been carried out to examin...

  18. A Family of Estimators of a Sensitive Variable Using Auxiliary Information in Stratified Random Sampling

    Directory of Open Access Journals (Sweden)

    Nadia Mushtaq

    2017-03-01

    Full Text Available In this article, a combined general family of estimators is proposed for estimating finite population mean of a sensitive variable in stratified random sampling with non-sensitive auxiliary variable based on randomized response technique. Under stratified random sampling without replacement scheme, the expression of bias and mean square error (MSE up to the first-order approximations are derived. Theoretical and empirical results through a simulation study show that the proposed class of estimators is more efficient than the existing estimators, i.e., usual stratified random sample mean estimator, Sousa et al (2014 ratio and regression estimator of the sensitive variable in stratified sampling.

  19. Reforming procedural skills training for pediatric residents: a randomized, interventional trial.

    Science.gov (United States)

    Gaies, Michael G; Morris, Shaine A; Hafler, Janet P; Graham, Dionne A; Capraro, Andrew J; Zhou, Jing; Landrigan, Christopher P; Sandora, Thomas J

    2009-08-01

    Pediatric housestaff are required to learn basic procedural skills and demonstrate competence during training. To our knowledge, an evidenced-based procedural skills curriculum does not exist. To create, implement, and evaluate a modular procedural skills curriculum for pediatric residents. A randomized, controlled trial was performed. Thirty-eight interns in the Boston Combined Residency Program who began their training in 2005 were enrolled and randomly assigned. Modules were created to teach residents bag-mask ventilation, venipuncture, peripheral intravenous catheter (PIV) insertion, and lumbar puncture skills. The curriculum was administered to participants in the intervention group during intern orientation. Interns in the control group learned procedural skills by usual methods. Subjects were evaluated by using a structured objective assessment on simulators immediately after the intervention and 7 months later. Success in performing live-patient procedures was self-reported by subjects. The primary outcome was successful performance of the procedure on the initial assessment. Secondary outcomes included checklist and knowledge examination scores, live-patient success, and qualitative assessment of the curriculum. Participants in the intervention group performed PIV placement more successfully than controls (79% vs 35%) and scored significantly higher on the checklist for PIV placement (81% vs 61%) and lumbar puncture (77% vs 68%) at the initial assessment. There were no differences between groups at month 7, and both groups demonstrated declining skills. There were no statistically significant differences in success on live-patient procedures. Those in the intervention group scored significantly higher on knowledge examinations. Participants in the intervention group were more successful performing certain simulated procedures than controls when tested immediately after receiving the curriculum but demonstrated declining skills thereafter. Future efforts

  20. Randomized Comparison of 3 High-Level Disinfection and Sterilization Procedures for Duodenoscopes.

    Science.gov (United States)

    Snyder, Graham M; Wright, Sharon B; Smithey, Anne; Mizrahi, Meir; Sheppard, Michelle; Hirsch, Elizabeth B; Chuttani, Ram; Heroux, Riley; Yassa, David S; Olafsdottir, Lovisa B; Davis, Roger B; Anastasiou, Jiannis; Bapat, Vijay; Bidari, Kiran; Pleskow, Douglas K; Leffler, Daniel; Lane, Benjamin; Chen, Alice; Gold, Howard S; Bartley, Anthony; King, Aleah D; Sawhney, Mandeep S

    2017-10-01

    Duodenoscopes have been implicated in the transmission of multidrug-resistant organisms (MDRO). We compared the frequency of duodenoscope contamination with MDRO or any other bacteria after disinfection or sterilization by 3 different methods. We performed a single-center prospective randomized study in which duodenoscopes were randomly reprocessed by standard high-level disinfection (sHLD), double high-level disinfection (dHLD), or standard high-level disinfection followed by ethylene oxide gas sterilization (HLD/ETO). Samples were collected from the elevator mechanism and working channel of each duodenoscope and cultured before use. The primary outcome was the proportion of duodenoscopes with an elevator mechanism or working channel culture showing 1 or more MDRO; secondary outcomes included the frequency of duodenoscope contamination with more than 0 and 10 or more colony-forming units (CFU) of aerobic bacterial growth on either sampling location. After 3 months of enrollment, the study was closed because of the futility; we did not observe sufficient events to evaluate the primary outcome. Among 541 duodenoscope culture events, 516 were included in the final analysis. No duodenoscope culture in any group was positive for MDRO. Bacterial growth of more than 0 CFU was noted in 16.1% duodenoscopes in the sHLD group, 16.0% in the dHLD group, and 22.5% in the HLD/ETO group (P = .21). Bacterial growth or 10 or more CFU was noted in 2.3% of duodenoscopes in the sHLD group, 4.1% in the dHLD group, and 4.2% in the HLD/ETO group (P = .36). MRDOs were cultured from 3.2% of pre-procedure rectal swabs and 2.5% of duodenal aspirates. In a comparison of duodenoscopes reprocessed by sHLD, dHLD, or HLD/ETO, we found no significant differences between groups for MDRO or bacteria contamination. Enhanced disinfection methods (dHLD or HLD/ETO) did not provide additional protection against contamination. However, insufficient events occurred to assess our primary study end

  1. Empirical aspects about Heckman Procedure Application: Is there sample selection bias in the Brazilian Industry

    Directory of Open Access Journals (Sweden)

    Flávio Kaue Fiuza-Moura

    2015-12-01

    Full Text Available There are several labor market researches whose main goal is to analyze the probability of employment and the structure of wage determination and, for empirical purposes, most of these researches deploy Heckman sample selection bias hazard detection and correction procedure. However, few Brazilian studies are focused in this procedure applicability, especially concerning specific industries. This paper aims to approach these issues by testing the existence of sample selection bias in Brazilian manufacturing industry, and to analyze the impact of the bias correction procedure over the estimated coefficients of OLS Mincer equations. We found sample selection bias hazard only in manufacturing segments which average wages are lower than market average and only in groups of workers which average wage level is below the market average (women, especially blacks. The analysis and comparison of Mincer equations with and without Heckman’s sample selection bias correction procedure brought up that the estimation’s coefficients related to wage differential for male over female workers and the wage differential for urban over non-urban workers tends to be overestimated in cases which the sample selection bias isn’t corrected.

  2. Development of Radioanalytical and Microanalytical Procedures for the Determination of Actinides in Environmental Samples

    Energy Technology Data Exchange (ETDEWEB)

    Macsik, Zsuzsanna [Institute of Nuclear Techniques, Moegyetem rakpart 9, H-1111 Budapest (Hungary); Vajda, Nora [RadAnal Ltd., Bimbo ut 119/a, H-1026 Budapest (Hungary); Bene, Balazs [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Varga, Zsolt [Institute of Isotopes, Konkoly-Thege M. ut 29-33, H-1121 Budapest (Hungary)

    2008-07-01

    A radio-analytical procedure has been developed for the simultaneous determination of actinides in swipe samples by alpha-spectrometry after the separation of the actinides by extraction chromatography. The procedure is based on the complete decomposition of the sample by destruction with microwave digestion or ashing in furnace. Actinides are separated on an extraction chromatographic column filled with TRU resin (product of Eichrom Industries Inc.). Alpha sources prepared from the separated fractions of americium, plutonium, thorium and uranium are counted by alpha spectrometry. Micro-analytical procedure is being developed for the location and identification of individual particles containing fissile material using solid state nuclear track detectors. The parameters of alpha and fission track detection have been optimized and a procedure has been elaborated to locate the particles on the sample by defining the coordinates of the tracks created by the particles on the track detector. Development of a procedure is planned to separate the located particles using micromanipulator and these particles will be examined individually by different micro- and radio-analytical techniques. (authors)

  3. Comparison of ten different DNA extraction procedures with respect to their suitability for environmental samples.

    Science.gov (United States)

    Kuhn, Ramona; Böllmann, Jörg; Krahl, Kathrin; Bryant, Isaac Mbir; Martienssen, Marion

    2017-12-01

    DNA extraction for molecular biological applications usually requires target optimized extraction procedures depending on the origin of the samples. For environmental samples, a range of different procedures has been developed. We compared the applicability and efficiency of ten selected DNA extraction methods published in recent literature using four different environmental samples namely: activated sludge from a domestic wastewater treatment plant, river sediment, anaerobic digestion sludge and nitrifying enrichment culture. We assessed the suitability of the extraction procedures based on both DNA yield and quality. DNA quantification was performed by both ultra violet (UV) spectrophotometry and fluorescence spectrophotometry after staining with PicoGreen. In our study, DNA yields based on UV measurement were overestimated in most cases while DNA yields from fluorescence measurements correlated well with the sample load on agarose gels of crude DNA. The quality of the DNA extracts was determined by gel electrophoresis of crude DNA and PCR products from 16S rDNA with the universal primer set 27f/1525r. It was observed that gel electrophoresis of crude DNA was not always suitable to evaluate DNA integrity and purity since interfering background substances (e.g. humic substances) were not visible. Therefore, we strongly recommend examining the DNA quality of both crude DNA and 16S rDNA PCR products by gel electrophoresis when a new extraction method is established. Summarizing, we found four out of ten extraction procedures being applicable to all tested samples without noticeable restrictions. The procedure G (according to the standard method 432_10401 of the Lower Saxony State Office for Consumer Protection and Food Safety) had the broadest application range over procedure J (published by Wilson, 2001). These were followed by procedures F (Singka et al., 2012) and A (Bourrain et al., 1999). All four extraction procedures delivered reliable and reproducible crude

  4. Computer Corner: A Note on Pascal's Triangle and Simple Random Sampling.

    Science.gov (United States)

    Wright, Tommy

    1989-01-01

    Describes the algorithm used to select a simple random sample of certain size without having to list all possible samples and a justification based on Pascal's triangle. Provides testing results by various computers. (YP)

  5. Influence of Freezing and Storage Procedure on Human Urine Samples in NMR-Based Metabolomics

    OpenAIRE

    Burkhard Luy; Bernhard Watzl; Stefan Heissler; Achim Bub; Rist, Manuela J.; Benjamin Görling; Claudia Muhle-Goll

    2013-01-01

    It is consensus in the metabolomics community that standardized protocols should be followed for sample handling, storage and analysis, as it is of utmost importance to maintain constant measurement conditions to identify subtle biological differences. The aim of this work, therefore, was to systematically investigate the influence of freezing procedures and storage temperatures and their effect on NMR spectra as a potentially disturbing aspect for NMR-based metabolomics studies. Urine sample...

  6. Influence of pre-analytical procedures on genomic DNA integrity in blood samples: the SPIDIA experience.

    Science.gov (United States)

    Malentacchi, F; Ciniselli, C M; Pazzagli, M; Verderio, P; Barraud, L; Hartmann, C C; Pizzamiglio, S; Weisbuch, S; Wyrich, R; Gelmini, S

    2015-02-02

    DNA integrity is a critical part of the definition of genomic DNA (gDNA) quality and can influence downstream molecular applications. Pre-analytical variables as sample storage and DNA extraction methods can influence the quality and quantity of isolated DNA and affect molecular test performances. The aim of this paper is to investigate the role of blood sample storage and DNA extraction procedures on gDNA integrity and gDNA fragmentation impact on a molecular test. 157 DNA samples deriving from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. 157 DNA samples derived from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), which aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. Our results demonstrate that blood sample storage and DNA extraction procedures influence gDNA integrity and that the same blood sample which underwent a long range multiplex PCR based analytical test can provide different results if the adopted pre-analytical procedures are not standardized. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. Application of the Mantel-Haenszel Procedure to Complex Samples of Items.

    Science.gov (United States)

    Allen, Nancy L.; Donoghue, John R.

    This Monte Carlo study examined the effect of complex sampling of items on the measurement of differential item functioning (DIF) using the Mantel-Haenszel procedure. Data were generated using a three-parameter logistic item response theory model according to the balanced incomplete block (BIB) design used in the National Assessment of Educational…

  8. Sampling procedure in a willow plantation for estimation of moisture content

    DEFF Research Database (Denmark)

    Nielsen, Henrik Kofoed; Lærke, Poul Erik; Liu, Na

    2015-01-01

    Heating value and fuel quality of wood is closely connected to moisture content. In this work the variation of moisture content (MC) of short rotation coppice (SRC) willow shoots is described for five clones during one harvesting season. Subsequently an appropriate sampling procedure minimising l...

  9. 40 CFR 91.413 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ...”) analysis, the analyzer response must be stable at greater than 99 percent of the final reading for the... only) by the grab (“bag”) technique outlined in paragraph (c) of this section. (e) Hydrocarbon hang-up... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Exhaust sample procedure-gaseous...

  10. Influence of Freezing and Storage Procedure on Human Urine Samples in NMR-Based Metabolomics

    Directory of Open Access Journals (Sweden)

    Burkhard Luy

    2013-04-01

    Full Text Available It is consensus in the metabolomics community that standardized protocols should be followed for sample handling, storage and analysis, as it is of utmost importance to maintain constant measurement conditions to identify subtle biological differences. The aim of this work, therefore, was to systematically investigate the influence of freezing procedures and storage temperatures and their effect on NMR spectra as a potentially disturbing aspect for NMR-based metabolomics studies. Urine samples were collected from two healthy volunteers, centrifuged and divided into aliquots. Urine aliquots were frozen either at −20 °C, on dry ice, at −80 °C or in liquid nitrogen and then stored at −20 °C, −80 °C or in liquid nitrogen vapor phase for 1–5 weeks before NMR analysis. Results show spectral changes depending on the freezing procedure, with samples frozen on dry ice showing the largest deviations. The effect was found to be based on pH differences, which were caused by variations in CO2 concentrations introduced by the freezing procedure. Thus, we recommend that urine samples should be frozen at −20 °C and transferred to lower storage temperatures within one week and that freezing procedures should be part of the publication protocol.

  11. Sample Design and Estimation Procedures for a National Health Examination Survey of Children.

    Science.gov (United States)

    Bryant, E. Earl; And Others

    This report presents considerations for sample design and estimation procedures for the Health Examination Survey, one of the major survey programs employed by the National Center for Health Statistics. The survey collects data which provide national estimates and distributions of various health characteristics related to the growth and…

  12. Effect of music in endoscopy procedures: systematic review and meta-analysis of randomized controlled trials.

    Science.gov (United States)

    Wang, Man Cai; Zhang, Ling Yi; Zhang, Yu Long; Zhang, Ya Wu; Xu, Xiao Dong; Zhang, You Cheng

    2014-10-01

    Endoscopies are common clinical examinations that are somewhat painful and even cause fear and anxiety for patients. We performed this systematic review and meta-analysis of randomized controlled trials to determine the effect of music on patients undergoing various endoscopic procedures. We searched the Cochrane Library, Issue 6, 2013, PubMed, and EMBASE databases up to July 2013. Randomized controlled trials comparing endoscopies, with and without the use of music, were included. Two authors independently abstracted data and assessed risk of bias. Subgroup analyses were performed to examine the impact of music on different types of endoscopic procedures. Twenty-one randomized controlled trials involving 2,134 patients were included. The overall effect of music on patients undergoing a variety of endoscopic procedures significantly improved pain score (weighted mean difference [WMD] = -1.53, 95% confidence interval [CI] [-2.53, -0.53]), anxiety (WMD = -6.04, 95% CI [-9.61, -2.48]), heart rate (P = 0.01), arterial pressure (P music group, compared with the control group. Furthermore, music had little effect for patients undergoing colposcopy and bronchoscopy in the subanalysis. Our meta-analysis suggested that music may offer benefits for patients undergoing endoscopy, except in colposcopy and bronchoscopy. Wiley Periodicals, Inc.

  13. Exponential ratio-product type estimators under second order approximation in stratified random sampling

    OpenAIRE

    Singh, Rajesh; Sharma, Prayas; Smarandache, Florentin

    2014-01-01

    Singh et al (20009) introduced a family of exponential ratio and product type estimators in stratified random sampling. Under stratified random sampling without replacement scheme, the expressions of bias and mean square error (MSE) of Singh et al (2009) and some other estimators, up to the first- and second-order approximations are derived. Also, the theoretical findings are supported by a numerical example.

  14. Query-Based Sampling: Can we do Better than Random?

    NARCIS (Netherlands)

    Tigelaar, A.S.; Hiemstra, Djoerd

    2010-01-01

    Many servers on the web offer content that is only accessible via a search interface. These are part of the deep web. Using conventional crawling to index the content of these remote servers is impossible without some form of cooperation. Query-based sampling provides an alternative to crawling

  15. A Randomized Prospective Study Of The Use Of Ipads In Reducing Anxiety During Cast Room Procedures.

    Science.gov (United States)

    Ko, Justine S; Whiting, Zachariah; Nguyen, Cynthia; Liu, Raymond W; Gilmore, Allison

    2016-01-01

    Cast room procedures can be a source of anxiety for children. Various techniques, including music therapy, have been evaluated as a way to ease this anxiety. The use of iPads as a form of distraction during cast room procedures has not previously been evaluated and was the purpose of the current study. 146 children and adolescents who underwent cast room procedures during June- August 2015 were randomly assigned to one of three groups: no-iPad, iPad with video, or iPad with game. Patient heart rates were measured using a pulse oximeter in the waiting room, before the procedure, during the procedure, and after the procedure. Mean values for each group were calculated at each time interval and compared both between groups and within groups over time. There were no significant differences in baseline (waiting room) heart rate between the no-iPad and iPad groups. When compared with the no-iPad group, there was a trend toward decreased heart rate in the video group (p=0.13) and a significant increase in heart rate in the game group (p=0.026) before the procedure. There were no significant decreases in heart rate within any of the groups when comparing the waiting room heart rates with the during procedure heart rates. There was a significant difference between the no-iPad and video groups (p=0.047) when comparing the change in heart rate from baseline to before the procedure, with a decreased heart rate observed in the video group. The results of this study show a significant decrease in heart rate when transitioning from the waiting room to the cast room while watching videos on the iPad. iPad-based video delivery appears to decrease anxiety prior to cast room procedures. iPad-based game play is difficult to assess as elevations in heart rate prior to the procedure are presumed to be related to game play and confound the observed effect it may have on anxiety related to the procedure.

  16. Destructive and nondestructive procedures to obtain chicken carcass samples for Escherichia coli and Salmonella spp. detection.

    Science.gov (United States)

    Cossi, Marcus Vinícius Coutinho; de Almeida, Michelle Vieira; Dias, Mariane Rezende; de Arruda Pinto, Paulo Sérgio; Nero, Luís Augusto

    2011-12-01

    Destructive and nondestructive sampling procedures were compared for Escherichia coli and Salmonella spp. detection in 60 fresh chicken carcasses, which were submitted to the following sampling procedures: rinsing, skin swabbing, tissue excision, and skin excision; the proximity or not to the cloacae region was also considered. The obtained results were compared to identify significant differences (pchicken carcasses were positive for E. coli, and five were positive for Salmonella spp. For E. coli, nonsignificant differences were observed between rinsing and tissue excision, rinsing and skin excision, and skin excision and tissue excision (p>0.05), thus indicating equivalencies between these techniques. Skin swabbing produced a statistically significant lower frequency of positive results (pE. coli, thus indicating its inadequacy for detection of this microorganism. For Salmonella spp., no significant differences were observed between the sampling techniques (p>0.05), possibly due to the low overall frequency of positive carcasses. No significant differences in the number of positive samples (E. coli or Salmonella spp.) were observed between samples collected near or far from the cloacae region (p>0.05), regardless of the sampling technique. The obtained results demonstrate that the tested sampling techniques were equivalent for Salmonella spp. detection in chicken carcasses, as observed for E. coli with the exception of skin swabbing.

  17. Fast egg collection method greatly improves randomness of egg sampling in Drosophila melanogaster

    DEFF Research Database (Denmark)

    Schou, Mads Fristrup

    2013-01-01

    When obtaining samples for population genetic studies, it is essential that the sampling is random. For Drosophila, one of the crucial steps in sampling experimental flies is the collection of eggs. Here an egg collection method is presented, which randomizes the eggs in a water column and dimini......When obtaining samples for population genetic studies, it is essential that the sampling is random. For Drosophila, one of the crucial steps in sampling experimental flies is the collection of eggs. Here an egg collection method is presented, which randomizes the eggs in a water column...... and to obtain a representative collection of genotypes, the method presented here is strongly recommended when collecting eggs from Drosophila....

  18. Prospective randomized assessment of single versus double-gloving for general surgical procedures.

    Science.gov (United States)

    Na'aya, H U; Madziga, A G; Eni, U E

    2009-01-01

    There is increased tendency towards double-gloving by general surgeons in our practice, due probably to awareness of the risk of contamination with blood or other body fluids during surgery. The aim of the study was to compare the relative frequency of glove puncture in single-glove versus double glove sets in general surgical procedures, and to determine if duration of surgery affects perforation rate. Surgeons at random do single or double gloves at their discretion, for general surgical procedures. All the gloves used by the surgeons were assessed immediately after surgery for perforation. A total of 1120 gloves were tested, of which 880 were double-glove sets and 240 single-glove sets. There was no significant difference in the overall perforation rate between single and double glove sets (18.3% versus 20%). However, only 2.3% had perforations in both the outer and inner gloves in the double glove group. Therefore, there was significantly greater risk for blood-skin exposure in the single glove sets (p < 0.01). The perforation rate was also significantly greater during procedures lasting an hour or more compared to those lasting less than an hour (p < 0.01). Double-gloving reduces the risk of blood-skin contamination in all general surgical procedures, and especially so in procedures lasting an hour or more.

  19. Inflammatory Biomarkers and Risk of Schizophrenia: A 2-Sample Mendelian Randomization Study.

    Science.gov (United States)

    Hartwig, Fernando Pires; Borges, Maria Carolina; Horta, Bernardo Lessa; Bowden, Jack; Davey Smith, George

    2017-12-01

    Positive associations between inflammatory biomarkers and risk of psychiatric disorders, including schizophrenia, have been reported in observational studies. However, conventional observational studies are prone to bias, such as reverse causation and residual confounding, thus limiting our understanding of the effect (if any) of inflammatory biomarkers on schizophrenia risk. To evaluate whether inflammatory biomarkers have an effect on the risk of developing schizophrenia. Two-sample mendelian randomization study using genetic variants associated with inflammatory biomarkers as instrumental variables to improve inference. Summary association results from large consortia of candidate gene or genome-wide association studies, including several epidemiologic studies with different designs, were used. Gene-inflammatory biomarker associations were estimated in pooled samples ranging from 1645 to more than 80 000 individuals, while gene-schizophrenia associations were estimated in more than 30 000 cases and more than 45 000 ancestry-matched controls. In most studies included in the consortia, participants were of European ancestry, and the prevalence of men was approximately 50%. All studies were conducted in adults, with a wide age range (18 to 80 years). Genetically elevated circulating levels of C-reactive protein (CRP), interleukin-1 receptor antagonist (IL-1Ra), and soluble interleukin-6 receptor (sIL-6R). Risk of developing schizophrenia. Individuals with schizophrenia or schizoaffective disorders were included as cases. Given that many studies contributed to the analyses, different diagnostic procedures were used. The pooled odds ratio estimate using 18 CRP genetic instruments was 0.90 (random effects 95% CI, 0.84-0.97; P = .005) per 2-fold increment in CRP levels; consistent results were obtained using different mendelian randomization methods and a more conservative set of instruments. The odds ratio for sIL-6R was 1.06 (95% CI, 1.01-1.12; P = .02

  20. Comparison of statistical and operational properties of subject randomization procedures for large multicenter clinical trial treating medical emergencies

    Science.gov (United States)

    Zhao, Wenle; Mu, Yunming; Tayama, Darren; Yeatts, Sharon D.

    2015-01-01

    Large multicenter acute stroke trials demand a randomization procedure with a high level of treatment allocation randomness, an effective control on overall and within-site imbalances, and a minimized time delay of study treatment caused by the randomization procedure. Driven by the randomization algorithm design of A Study of the Efficacy and Safety of Activase (Alteplase) in Patients With Mild Stroke (PRISMS) (NCT02072226), this paper compares operational and statistical properties of different randomization algorithms in local, central, and step-forward randomization settings. Results show that the step-forward randomization with block urn design provides better performances over others. If the concern on the potential time delay is not serious and a central randomization system is available, the minimization method with an imbalance control threshold and a biased coin probability could be a better choice. PMID:25638754

  1. Start-up designs for response-adaptive randomization procedures with sequential estimation.

    Science.gov (United States)

    Haines, Linda M; Sadiq, Hassan

    2015-09-20

    Response-adaptive randomization procedures are appropriate for clinical trials in which two or more treatments are to be compared, patients arrive sequentially and the response of each patient is recorded before the next patient arrives. However, for those procedures that involve sequential estimation of model parameters, start-up designs are commonly required in order to provide initial estimates of the parameters. In this paper, a suite of such start-up designs for two treatments and binary patient responses are considered and compared in terms of the numbers of patients required in order to give meaningful parameters estimates, the number of patients allocated to the better treatment, and the bias in the parameter estimates. It is shown that permuted block designs with blocks of size 4 are to be preferred over a wide range of parameter values. For the case of two treatments, normal responses and selected start-up procedures, a design incorporating complete randomization followed appropriately by repeats of one of the treatments yields the minimum expected number of patients and is to be preferred. Copyright © 2015 John Wiley & Sons, Ltd.

  2. Procedures Performed during Hospitalizations for Malignant Pleural Effusions: Data from the 2012 National Inpatient Sample.

    Science.gov (United States)

    Fortin, Marc; Taghizadeh, Niloofar; Tremblay, Alain

    2018-02-07

    Malignant pleural effusions (MPE) are a common clinical problem. Little is known about the burden of MPE and of the treatments used to alleviate its symptoms on the United States Health Care System. We aimed to obtain a better portrait of inpatient pleural procedures performed in the United States. We conducted a retrospective analysis of MPE-associated hospitalizations using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample, Agency for Healthcare Research and Quality (HCUP-NIS 2012). Descriptive statistics were used to analyze procedures performed and their complications. Univariate and multivariate logistic regression models were used to explore the relationship between procedures performed and inpatient mortality and length of stay. Among the 126,825 hospital admissions with a diagnosis of MPE, 72,240 included one or more pleural procedures. Thoracentesis (54,070) was the most frequently performed procedure followed by chest tube placement (23,035), chemical pleurodesis (10,240), and thoracoscopy (6,615). Hospitalization for lung and breast cancer was more likely to include pleural procedures compared to hospitalization for other types of cancer (59.2 and 65.6%, respectively, p < 0.0001). Chemical pleurodesis through a chest tube compared to thoracoscopic chemical pleurodesis was performed more frequently (57 vs. 43%, p < 0.001) and associated with a longer hospital stay (4.9 vs. 5.9 days, p < 0.001). Hospital admissions for MPE represent a large burden on the US Health Care System. Many hospitalizations are associated with procedures not expected to reduce the recurrence rate of this condition. © 2018 S. Karger AG, Basel.

  3. New procedure of selected biogenic amines determination in wine samples by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

    2014-06-27

    Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

  4. Multivariate Optimization in Preconcentration Procedure for Manganese Determination in Seawater Samples by FAAS

    OpenAIRE

    Ferreira, Adriana C.; Korn, Maria das Graças Andrade; Ferreira, Sergio Luis Costa

    2004-01-01

    Texto completo: acesso restrito . p. 271-278 In the present paper, a preconcentration procedure for manganese determination in seawater samples by flame atomic absorption spectrometry (FAAS) is proposed. It is based on the solid phase extraction of manganese(II) ions as a 4-(2-pyridylazo-resorcinol) (PAR) chelate using activated carbon as sorbent. Optimization of the experimental parameters (pH, activated carbon mass, PAR mass and shaking time) was carried out using a two-level full factor...

  5. [Sampling in qualitative research: a proposal for procedures to detect theoretical saturation].

    Science.gov (United States)

    Fontanella, Bruno Jose Barcellos; Luchesi, Bruna Moretti; Saidel, Maria Giovana Borges; Ricas, Janete; Turato, Egberto Ribeiro; Melo, Débora Gusmão

    2011-02-01

    A qualitative study's methodological transparency is considered a key factor for achieving its reliability and should be guaranteed by the researchers. Closing the sampling process by saturation is a common approach, but it is rarely made explicit in research reports. Qualitative researchers also commonly experience technical difficulties in objectively identifying saturation. This article proposes a method to organize sample closing by saturation, with a sequence of eight procedural steps for treating and analyzing data collected through open or semi-structured interviews or focus groups. The article aims to help researchers objectively explain how and when saturation occurred and to allow their readers to know how this process occurred.

  6. Parameter Estimation in Stratified Cluster Sampling under Randomized Response Models for Sensitive Question Survey.

    Science.gov (United States)

    Pu, Xiangke; Gao, Ge; Fan, Yubo; Wang, Mian

    2016-01-01

    Randomized response is a research method to get accurate answers to sensitive questions in structured sample survey. Simple random sampling is widely used in surveys of sensitive questions but hard to apply on large targeted populations. On the other side, more sophisticated sampling regimes and corresponding formulas are seldom employed to sensitive question surveys. In this work, we developed a series of formulas for parameter estimation in cluster sampling and stratified cluster sampling under two kinds of randomized response models by using classic sampling theories and total probability formulas. The performances of the sampling methods and formulas in the survey of premarital sex and cheating on exams at Soochow University were also provided. The reliability of the survey methods and formulas for sensitive question survey was found to be high.

  7. Parameter Estimation in Stratified Cluster Sampling under Randomized Response Models for Sensitive Question Survey.

    Directory of Open Access Journals (Sweden)

    Xiangke Pu

    Full Text Available Randomized response is a research method to get accurate answers to sensitive questions in structured sample survey. Simple random sampling is widely used in surveys of sensitive questions but hard to apply on large targeted populations. On the other side, more sophisticated sampling regimes and corresponding formulas are seldom employed to sensitive question surveys. In this work, we developed a series of formulas for parameter estimation in cluster sampling and stratified cluster sampling under two kinds of randomized response models by using classic sampling theories and total probability formulas. The performances of the sampling methods and formulas in the survey of premarital sex and cheating on exams at Soochow University were also provided. The reliability of the survey methods and formulas for sensitive question survey was found to be high.

  8. Effects of Music Listening During Loop Electrosurgical Excision Procedure on Pain and Anxiety: A Randomized Trial.

    Science.gov (United States)

    Chantawong, Nopwaree; Charoenkwan, Kittipat

    2017-10-01

    The aim of the study was to compare pain, anxiety, and satisfaction between women, who listened to music, and those who did not during loop electrosurgical excision procedure (LEEP). Participants were randomly assigned into two groups. In group 1 (music), the participants listened to relaxing instrumental music through the stereo headset from the time of arrival at the preoperative waiting room until the procedure completed. For group 2 (control), the participants underwent LEEP without music listening. The women rated pain, anxiety, and satisfaction according to 10-cm visual analog scales. Pain was assessed at the time of speculum insertion (baseline pain) and immediately after the LEEP completed (procedural pain). Anxiety and satisfaction were examined just before starting the LEEP and 10 minutes after the procedure completed. One hundred fifty patients (74 in music group and 76 in control group) participated. Mean baseline pain scores after speculum insertion were comparable between the groups (3.7 in the music group vs. 3.5 in the control group, p = .55). Mean procedural pain scores were not different between the groups (4.7 in the music group vs. 5.2 in the control group, p = .32). The differences of the procedural pain scores from baseline were statistically comparable between the study groups (0.9 in the music group vs. 1.7 in the control group, p = .15). There were no significant differences in anxiety and satisfaction scores at any time points assessed between the groups. The effects of music listening on reducing pain and anxiety during LEEP could not be demonstrated in this study.

  9. A Procedure for Accurately Measuring the Shaker Overturning Moment During Random Vibration Tests

    Science.gov (United States)

    Nayeri, Reza D.

    2011-01-01

    Motivation: For large system level random vibration tests, there may be some concerns about the shaker's capability for the overturning moment. It is the test conductor's responsibility to predict and monitor the overturning moment during random vibration tests. If the predicted moment is close to the shaker's capability, test conductor must measure the instantaneous moment at low levels and extrapolate to higher levels. That data will be used to decide whether it is safe to proceed to the next test level. Challenge: Kistler analog formulation for computing the real-time moment is only applicable to very limited cases in which we have 3 or 4 load cells installed at shaker interface with hardware. Approach: To overcome that limitation, a simple procedure was developed for computing the overturning moment time histories using the measured time histories of the individual load cells.

  10. Simulation improves procedural protocol adherence during central venous catheter placement: a randomized-controlled trial

    Science.gov (United States)

    Peltan, Ithan D.; Shiga, Takashi; Gordon, James A.; Currier, Paul F.

    2015-01-01

    Background Simulation training may improve proficiency at and reduces complications from central venous catheter (CVC) placement, but the scope of simulation’s effect remains unclear. This randomized controlled trial evaluated the effects of a pragmatic CVC simulation program on procedural protocol adherence, technical skill, and patient outcomes. Methods Internal medicine interns were randomized to standard training for CVC insertion or standard training plus simulation-based mastery training. Standard training involved a lecture, a video-based online module, and instruction by the supervising physician during actual CVC insertions. Intervention-group subjects additionally underwent supervised training on a venous access simulator until they demonstrated procedural competence. Raters evaluated interns’ performance during internal jugular CVC placement on actual patients in the medical intensive care unit. Generalized estimating equations were used to account for outcome clustering within trainees. Results We observed 52 interns place 87 CVCs. Simulation-trained interns exhibited better adherence to prescribed procedural technique than interns who received only standard training (p=0.024). There were no significant differences detected in first-attempt or overall cannulation success rates, mean needle passes, global assessment scores or complication rates. Conclusions Simulation training added to standard training improved protocol adherence during CVC insertion by novice practitioners. This study may have been too small to detect meaningful differences in venous cannulation proficiency and other clinical outcomes, highlighting the difficulty of patient-centered simulation research in settings where poor outcomes are rare. For high-performing systems, where protocol deviations may provide an important proxy for rare procedural complications, simulation may improve CVC insertion quality and safety. PMID:26154250

  11. Utilization of vertebroplasty and kyphoplasty procedures throughout the United States over a recent decade: an analysis of the Nationwide Inpatient Sample

    Science.gov (United States)

    Shillingford, Jamal N.; Lombardi, Joseph M.; Mueller, John D.; Reddy, Hemant; Saifi, Comron; Fischer, Charla R.; Ludwig, Steven C.; Lenke, Lawrence G.; Lehman, Ronald A.

    2017-01-01

    Background Given the increasing societal focus on health care utilization and value-based care, it is essential to understand the demographic and economic data surrounding percutaneous vertebral augmentation procedures performed in the United States. Double-blinded prospective randomized controlled trials have shown no benefit to the use of vertebroplasty over a sham procedure in the treatment of vertebral fractures. Contrastingly, kyphoplasty may be beneficial when appropriately indicated. Methods The National Inpatient Sample (NIS) database was queried for patients who underwent either kyphoplasty (ICD-9-CM 81.66) or vertebroplasty (ICD-9-CM 81.65) procedures between 2006 and 2014 across 44 states. Demographic and economic data were obtained which included the annual number of surgeries, age, sex, insurance type, location, and frequency of routine discharge. The NIS database represents a 20% sample of discharges from U.S. hospitals, which is weighted to provide national estimates. Results In 2014, an estimated total number of 19,420 kyphoplasty and 6,130 vertebroplasty procedures were performed across the United States. The number of vertebroplasty procedures decreased 53% from 13,128 in 2008. Similarly, the number of kyphoplasty procedures decreased 17% from 23,320 in 2007. Based on payer, Medicare patients comprised 83% of those billed for kyphoplasty and vertebroplasty, and 75% of procedures were utilized in areas designated as “not low income”. In 2014, patients in the South Atlantic region comprised 24% of vertebroplasty and 28% of kyphoplasty cases, far more than any other region. Additionally, kyphoplasty and vertebroplasty were more often performed in teaching facilities rather than community hospitals (60% and 67%, respectively). Conclusions Since the publication of two double-blind, prospective randomized controlled trials showed no benefit of vertebroplasty over a sham procedure, there has been a significant decrease in both kyphoplasty and

  12. The Alaska Commercial Fisheries Water Quality Sampling Methods and Procedures Manual

    Energy Technology Data Exchange (ETDEWEB)

    Folley, G.; Pearson, L.; Crosby, C. [Alaska Dept. of Environmental Conservation, Soldotna, AK (United States); DeCola, E.; Robertson, T. [Nuka Research and Planning Group, Seldovia, AK (United States)

    2006-07-01

    A comprehensive water quality sampling program was conducted in response to the oil spill that occurred when the M/V Selendang Ayu ship ran aground near a major fishing port at Unalaska Island, Alaska in December 2004. In particular, the sampling program focused on the threat of spilled oil to the local commercial fisheries resources. Spill scientists were unable to confidently model the movement of oil away from the wreck because of limited oceanographic data. In order to determine which fish species were at risk of oil contamination, a real-time assessment of how and where the oil was moving was needed, because the wreck became a continual source of oil release for several weeks after the initial grounding. The newly developed methods and procedures used to detect whole oil during the sampling program will be presented in the Alaska Commercial Fisheries Water Quality Sampling Methods and Procedures Manual which is currently under development. The purpose of the manual is to provide instructions to spill managers while they try to determine where spilled oil has or has not been encountered. The manual will include a meaningful data set that can be analyzed in real time to assess oil movement and concentration. Sections on oil properties and processes will be included along with scientific water quality sampling methods for whole and dissolved phase oil to assess potential contamination of commercial fishery resources and gear in Alaska waters during an oil spill. The manual will present a general discussion of factors that should be considered when designing a sampling program after a spill. In order to implement Alaska's improved seafood safety measures, the spatial scope of spilled oil must be known. A water quality sampling program can provide state and federal fishery managers and food safety inspectors with important information as they identify at-risk fisheries. 11 refs., 7 figs.

  13. A Family of Estimators of a Sensitive Variable Using Auxiliary Information in Stratified Random Sampling

    National Research Council Canada - National Science Library

    Nadia Mushtaq; Noor Ul Amin; Muhammad Hanif

    2017-01-01

    In this article, a combined general family of estimators is proposed for estimating finite population mean of a sensitive variable in stratified random sampling with non-sensitive auxiliary variable...

  14. Standardized Nanomechanical Atomic Force Microscopy Procedure (SNAP) for Measuring Soft and Biological Samples.

    Science.gov (United States)

    Schillers, Hermann; Rianna, Carmela; Schäpe, Jens; Luque, Tomas; Doschke, Holger; Wälte, Mike; Uriarte, Juan José; Campillo, Noelia; Michanetzis, Georgios P A; Bobrowska, Justyna; Dumitru, Andra; Herruzo, Elena T; Bovio, Simone; Parot, Pierre; Galluzzi, Massimiliano; Podestà, Alessandro; Puricelli, Luca; Scheuring, Simon; Missirlis, Yannis; Garcia, Ricardo; Odorico, Michael; Teulon, Jean-Marie; Lafont, Frank; Lekka, Malgorzata; Rico, Felix; Rigato, Annafrancesca; Pellequer, Jean-Luc; Oberleithner, Hans; Navajas, Daniel; Radmacher, Manfred

    2017-07-11

    We present a procedure that allows a reliable determination of the elastic (Young's) modulus of soft samples, including living cells, by atomic force microscopy (AFM). The standardized nanomechanical AFM procedure (SNAP) ensures the precise adjustment of the AFM optical lever system, a prerequisite for all kinds of force spectroscopy methods, to obtain reliable values independent of the instrument, laboratory and operator. Measurements of soft hydrogel samples with a well-defined elastic modulus using different AFMs revealed that the uncertainties in the determination of the deflection sensitivity and subsequently cantilever's spring constant were the main sources of error. SNAP eliminates those errors by calculating the correct deflection sensitivity based on spring constants determined with a vibrometer. The procedure was validated within a large network of European laboratories by measuring the elastic properties of gels and living cells, showing that its application reduces the variability in elastic moduli of hydrogels down to 1%, and increased the consistency of living cells elasticity measurements by a factor of two. The high reproducibility of elasticity measurements provided by SNAP could improve significantly the applicability of cell mechanics as a quantitative marker to discriminate between cell types and conditions.

  15. A New Estimator For Population Mean Using Two Auxiliary Variables in Stratified random Sampling

    OpenAIRE

    Singh, Rajesh; Malik, Sachin

    2014-01-01

    In this paper, we suggest an estimator using two auxiliary variables in stratified random sampling. The propose estimator has an improvement over mean per unit estimator as well as some other considered estimators. Expressions for bias and MSE of the estimator are derived up to first degree of approximation. Moreover, these theoretical findings are supported by a numerical example with original data. Key words: Study variable, auxiliary variable, stratified random sampling, bias and mean squa...

  16. Membrane biofouling characterization: effects of sample preparation procedures on biofilm structure and the microbial community

    KAUST Repository

    Xue, Zheng

    2014-07-15

    Ensuring the quality and reproducibility of results from biofilm structure and microbial community analysis is essential to membrane biofouling studies. This study evaluated the impacts of three sample preparation factors (ie number of buffer rinses, storage time at 4°C, and DNA extraction method) on the downstream analysis of nitrifying biofilms grown on ultrafiltration membranes. Both rinse and storage affected biofilm structure, as suggested by their strong correlation with total biovolume, biofilm thickness, roughness and the spatial distribution of EPS. Significant variations in DNA yields and microbial community diversity were also observed among samples treated by different rinses, storage and DNA extraction methods. For the tested biofilms, two rinses, no storage and DNA extraction with both mechanical and chemical cell lysis from attached biofilm were the optimal sample preparation procedures for obtaining accurate information about biofilm structure, EPS distribution and the microbial community. © 2014 © 2014 Taylor & Francis.

  17. The effect of music in gynaecological office procedures on pain, anxiety and satisfaction: a randomized controlled trial

    OpenAIRE

    Mak, N; Reinders, I. M. A.; Slockers, S. A.; Westen, E. H. M. N.; Maas, J. W. M.; M.Y. Bongers

    2017-01-01

    Background Pain can interfere with office procedures in gynaecology. The aim of this study is to measure the positive effect of music in gynaecological office procedures. Methods A randomized controlled trial was performed between October 2014 and January 2016. Women scheduled for an office hysteroscopy or colposcopy were eligible for randomization in the music group or control group. Stratification for hysteroscopy and colposcopy took place. The primary outcome is patients? level of pain dur...

  18. Conflict-cost based random sampling design for parallel MRI with low rank constraints

    Science.gov (United States)

    Kim, Wan; Zhou, Yihang; Lyu, Jingyuan; Ying, Leslie

    2015-05-01

    In compressed sensing MRI, it is very important to design sampling pattern for random sampling. For example, SAKE (simultaneous auto-calibrating and k-space estimation) is a parallel MRI reconstruction method using random undersampling. It formulates image reconstruction as a structured low-rank matrix completion problem. Variable density (VD) Poisson discs are typically adopted for 2D random sampling. The basic concept of Poisson disc generation is to guarantee samples are neither too close to nor too far away from each other. However, it is difficult to meet such a condition especially in the high density region. Therefore the sampling becomes inefficient. In this paper, we present an improved random sampling pattern for SAKE reconstruction. The pattern is generated based on a conflict cost with a probability model. The conflict cost measures how many dense samples already assigned are around a target location, while the probability model adopts the generalized Gaussian distribution which includes uniform and Gaussian-like distributions as special cases. Our method preferentially assigns a sample to a k-space location with the least conflict cost on the circle of the highest probability. To evaluate the effectiveness of the proposed random pattern, we compare the performance of SAKEs using both VD Poisson discs and the proposed pattern. Experimental results for brain data show that the proposed pattern yields lower normalized mean square error (NMSE) than VD Poisson discs.

  19. Hartmann's Procedure or Primary Anastomosis for Generalized Peritonitis due to Perforated Diverticulitis: A Prospective Multicenter Randomized Trial (DIVERTI).

    Science.gov (United States)

    Bridoux, Valerie; Regimbeau, Jean Marc; Ouaissi, Mehdi; Mathonnet, Muriel; Mauvais, Francois; Houivet, Estelle; Schwarz, Lilian; Mege, Diane; Sielezneff, Igor; Sabbagh, Charles; Tuech, Jean-Jacques

    2017-12-01

    About 25% of patients with acute diverticulitis require emergency intervention. Currently, most patients with diverticular peritonitis undergo a Hartmann's procedure. Our objective was to assess whether primary anastomosis (PA) with a diverting stoma results in lower mortality rates than Hartmann's procedure (HP) in patients with diverticular peritonitis. We conducted a multicenter randomized controlled trial conducted between June 2008 and May 2012: the DIVERTI (Primary vs Secondary Anastomosis for Hinchey Stage III-IV Diverticulitis) trial. Follow-up duration was up to 18 months. A random sample of 102 eligible participants with purulent or fecal diverticular peritonitis from tertiary care referral centers and associated centers in France were equally randomized to either a PA arm or to an HP arm. Data were analyzed on an intention-to-treat basis. The primary end point was mortality rate at 18 months. Secondary outcomes were postoperative complications, operative time, length of hospital stay, rate of definitive stoma, and morbidity. All 102 patients enrolled were comparable for age (p = 0.4453), sex (p = 0.2347), Hinchey stage III vs IV (p = 0.2347), and Mannheim Peritonitis Index (p = 0.0606). Overall mortality did not differ significantly between HP (7.7%) and PA (4%) (p = 0.4233). Morbidity for both resection and stoma reversal operations were comparable (39% in the HP arm vs 44% in the PA arm; p = 0.4233). At 18 months, 96% of PA patients and 65% of HP patients had a stoma reversal (p = 0.0001). Although mortality was similar in both arms, the rate of stoma reversal was significantly higher in the PA arm. This trial provides additional evidence in favor of PA with diverting ileostomy over HP in patients with diverticular peritonitis. ClinicalTrials.gov Identifier: NCT 00692393. Copyright © 2017. Published by Elsevier Inc.

  20. Biclustering of gene expression data using reactive greedy randomized adaptive search procedure.

    Science.gov (United States)

    Dharan, Smitha; Nair, Achuthsankar S

    2009-01-30

    Biclustering algorithms belong to a distinct class of clustering algorithms that perform simultaneous clustering of both rows and columns of the gene expression matrix and can be a very useful analysis tool when some genes have multiple functions and experimental conditions are diverse. Cheng and Church have introduced a measure called mean squared residue score to evaluate the quality of a bicluster and has become one of the most popular measures to search for biclusters. In this paper, we review basic concepts of the metaheuristics Greedy Randomized Adaptive Search Procedure (GRASP)-construction and local search phases and propose a new method which is a variant of GRASP called Reactive Greedy Randomized Adaptive Search Procedure (Reactive GRASP) to detect significant biclusters from large microarray datasets. The method has two major steps. First, high quality bicluster seeds are generated by means of k-means clustering. In the second step, these seeds are grown using the Reactive GRASP, in which the basic parameter that defines the restrictiveness of the candidate list is self-adjusted, depending on the quality of the solutions found previously. We performed statistical and biological validations of the biclusters obtained and evaluated the method against the results of basic GRASP and as well as with the classic work of Cheng and Church. The experimental results indicate that the Reactive GRASP approach outperforms the basic GRASP algorithm and Cheng and Church approach. The Reactive GRASP approach for the detection of significant biclusters is robust and does not require calibration efforts.

  1. The influence of a eutectic mixture of lidocaine and prilocaine on minor surgical procedures: a randomized controlled double-blind trial.

    LENUS (Irish Health Repository)

    Shaikh, Faisal M

    2012-01-31

    BACKGROUND: A eutectic mixture of lidocaine and prilocaine (EMLA) has been shown to be effective in reducing pain from needle sticks, including those associated with blood sampling and intravenous insertion. OBJECTIVE: To evaluate the effectiveness of EMLA cream applied before needle puncture for local anesthetic administration before minor surgical procedures in this double-blind, randomized, controlled, parallel-group study. MATERIALS AND METHODS: Patients were randomly assigned to receive EMLA or placebo cream (Aqueous) applied under an occlusive dressing. After the procedure, patients were asked to rate the needle prick and procedure pain on a visual analog scale (0=no pain; 10=maximum pain). RESULTS: A total of 94 minor surgical procedures (49 in EMLA and 45 in control) were performed. The mean needle-stick pain score in the EMLA group was significantly lower than in the control group (2.7 vs. 5.7, p<.001, Mann-Whitney U-test). There was also significantly lower procedure pain in the EMLA group than in the control group (0.83 vs. 1.86, p=.009). There were no complications associated with the use of EMLA. CONCLUSION: EMLA effectively reduces the preprocedural needle-stick pain and procedural pain associated with minor surgical procedures.

  2. Automated fast procedure for the simultaneous extraction of hair sample performed with an automated workstation.

    Science.gov (United States)

    Angeli, I; Minoli, M; Ravelli, A; Gigli, F; Lodi, F

    2012-05-10

    Hair testing has a leading role in toxicology practice and even more in those aspects tightly linked to the assessment of psychoactive drug use and abuse in social life. The objective of the present study was to develop and validate an automated SPE sample-preparation step, suited for GC/MS confirmation analysis of basic drugs in hair drug control. The method was studied and optimized for quantitative determination and in a second time it was extended to real hair samples. The purpose of method validation was to ensure good reliability, reproducibility and quickness. Janus Automated Workstation (PerkinElmer) was employed to perform SPE hair extraction, using 96-well plate SPEC MP1 acquired from Varian (Agilent Technologies). After derivatization of dried extracts, screening confirmations were performed using gas chromatography (GC) followed by mass spectrometry (MS). GC/MS data were validated following standard guidelines, but our attention was focused on three headings: samples cross-contamination, "memory effect" and extraction recovery. Validation requests were fully accomplished and we always obtained best results with the automated procedure. For instance, analytes mean recovery was between 70 and 90% and data analysis proved that no contamination between samples occurred. The automated workstation has shown good reliability (cross contamination and "memory effect" were tested and excluded), effectiveness (no false negative was detected), solvent saving (500μL/sample vs traditionally LLE 4mL/sample) and quickness (50min for 96 tests cycle). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  3. TVT-Exact and midurethral sling (SLING-IUFT) operative procedures: a randomized study.

    Science.gov (United States)

    Aniuliene, Rosita; Aniulis, Povilas; Skaudickas, Darijus

    2015-01-01

    The aim of the study is to compare results, effectiveness and complications of TVT exact and midurethral sling (SLING-IUFT) operations in the treatment of female stress urinary incontinence (SUI). A single center nonblind, randomized study of women with SUI who were randomized to TVT-Exact and SLING-IUFT was performed by one surgeon from April 2009 to April 2011. SUI was diagnosed on coughing and Valsalva test and urodynamics (cystometry and uroflowmetry) were assessed before operation and 1 year after surgery. This was a prospective randomized study. The follow up period was 12 months. 76 patients were operated using the TVT-Exact operation and 78 patients - using the SLING-IUFT operation. There was no statistically significant differences between groups for BMI, parity, menopausal status and prolapsed stage (no patients had cystocele greater than stage II). Mean operative time was significantly shorter in the SLING-IUFT group (19 ± 5.6 min.) compared with the TVT-Exact group (27 ± 7.1 min.). There were statistically significant differences in the effectiveness of both procedures: TVT-Exact - at 94.5% and SLING-IUFT - at 61.2% after one year. Hospital stay was statistically significantly shorter in the SLING-IUFT group (1. 2 ± 0.5 days) compared with the TVT-Exact group (3.5 ± 1.5 days). Statistically significantly fewer complications occurred in the SLING-IUFT group. the TVT-Exact and SLING-IUFT operations are both effective for surgical treatment of female stress urinary incontinence. The SLING-IUFT involved a shorter operation time and lower complications rate., the TVT-Exact procedure had statistically significantly more complications than the SLING-IUFT operation, but a higher effectiveness.

  4. Randomized clinical trial of propofol versus alfentanil for moderate procedural sedation in the emergency department.

    Science.gov (United States)

    Miner, James R; Driver, Brian E; Moore, Johanna C; Faegerstrom, Erik; Klein, Lauren; Prekker, Matthew; Cole, Jon B

    2017-10-01

    To compare the frequency of airway and respiratory adverse events leading to an intervention between moderate sedation using alfentanil or propofol. We performed a randomized clinical trial in which adults undergoing moderate sedation in the ED received either alfentanil or propofol. Our primary outcome was the frequency of airway and respiratory adverse events leading to an intervention. Other outcomes included sedation depth, efficacy, sedation time, patient satisfaction, pain, and satisfaction. 108 subjects completed the trial: 52 receiving alfentanil and 56 receiving propofol. Airway or respiratory adverse events leading to an intervention were similar between the two groups: 23% for alfentanil and 20% for propofol (p=0.657). There were no serious adverse events in any group. Secondary outcomes were notably different in the rate of reported pain (48% for alfentanil, 13% for propofol) and recall (75% for alfentanil, 23% for propofol) and similar in the rate of satisfaction with the procedure (87% for alfentanil, 84% for propofol). We found a similar frequency of airway and respiratory adverse events leading to intervention between alfentanil and propofol used for moderate procedural sedation. Both agents appear safe for moderate procedural sedation. Copyright © 2017 Elsevier Inc. All rights reserved.

  5. Misrepresenting random sampling? A systematic review of research papers in the Journal of Advanced Nursing.

    Science.gov (United States)

    Williamson, Graham R

    2003-11-01

    This paper discusses the theoretical limitations of the use of random sampling and probability theory in the production of a significance level (or P-value) in nursing research. Potential alternatives, in the form of randomization tests, are proposed. Research papers in nursing, medicine and psychology frequently misrepresent their statistical findings, as the P-values reported assume random sampling. In this systematic review of studies published between January 1995 and June 2002 in the Journal of Advanced Nursing, 89 (68%) studies broke this assumption because they used convenience samples or entire populations. As a result, some of the findings may be questionable. The key ideas of random sampling and probability theory for statistical testing (for generating a P-value) are outlined. The result of a systematic review of research papers published in the Journal of Advanced Nursing is then presented, showing how frequently random sampling appears to have been misrepresented. Useful alternative techniques that might overcome these limitations are then discussed. REVIEW LIMITATIONS: This review is limited in scope because it is applied to one journal, and so the findings cannot be generalized to other nursing journals or to nursing research in general. However, it is possible that other nursing journals are also publishing research articles based on the misrepresentation of random sampling. The review is also limited because in several of the articles the sampling method was not completely clearly stated, and in this circumstance a judgment has been made as to the sampling method employed, based on the indications given by author(s). Quantitative researchers in nursing should be very careful that the statistical techniques they use are appropriate for the design and sampling methods of their studies. If the techniques they employ are not appropriate, they run the risk of misinterpreting findings by using inappropriate, unrepresentative and biased samples.

  6. Procedures for Handling and Chemical Analysis of Sediment and Water Samples,

    Science.gov (United States)

    1981-05-01

    Method 1: Potassium Chloride Extraction 3-154 Method 2: Distillation 3-155 Method 3: Distilled Water Extraction 3-157 Nitrogen (Nitrate) 3-159...185 Procedures for Water Samples 3-185 Method 1: Colorimotric, Semiautomated with Block Digestor 3-185 Method 2: Manual Colorimotrir, Titrimetrie 3-190...Phenfls 21.11 5.00 - 3(-.50 Total Phosphorus 9.00 6.00 - 12.50 Orthophosphorus 5.57 2.00 - 10.00 Potassium 8.77 2.00 - 20.00 (Continued) t Polychlorinated

  7. Comparison of kriging interpolation precision between grid sampling scheme and simple random sampling scheme for precision agriculture

    Directory of Open Access Journals (Sweden)

    Jiang Houlong

    2016-01-01

    Full Text Available Sampling methods are important factors that can potentially limit the accuracy of predictions of spatial distribution patterns. A 10 ha tobacco-planted field was selected to compared the accuracy in predicting the spatial distribution of soil properties by using ordinary kriging and cross validation methods between grid sampling and simple random sampling scheme (SRS. To achieve this objective, we collected soil samples from the topsoil (0-20 cm in March 2012. Sample numbers of grid sampling and SRS were both 115 points each. Accuracies of spatial interpolation using the two sampling schemes were then evaluated based on validation samples (36 points and deviations of the estimates. The results suggested that soil pH and nitrate-N (NO3-N had low variation, whereas all other soil properties exhibited medium variation. Soil pH, organic matter (OM, total nitrogen (TN, cation exchange capacity (CEC, total phosphorus (TP and available phosphorus (AP matched the spherical model, whereas the remaining variables fit an exponential model with both sampling methods. The interpolation error of soil pH, TP, and AP was the lowest in SRS. The errors of interpolation for OM, CEC, TN, available potassium (AK and total potassium (TK were the lowest for grid sampling. The interpolation precisions of the soil NO3-N showed no significant differences between the two sampling schemes. Considering our data on interpolation precision and the importance of minerals for cultivation of flue-cured tobacco, the grid-sampling scheme should be used in tobacco-planted fields to determine the spatial distribution of soil properties. The grid-sampling method can be applied in a practical and cost-effective manner to facilitate soil sampling in tobacco-planted field.

  8. Comparison of sample preparation procedures on metal(loid) fractionation patterns in lichens.

    Science.gov (United States)

    Kroukamp, E M; Godeto, T W; Forbes, P B C

    2017-08-13

    The effects of different sample preparation strategies and storage on metal(loid) fractionation trends in plant material is largely underresearched. In this study, a bulk sample of lichen Parmotrema austrosinense (Zahlbr.) Hale was analysed for its total extractable metal(loid) content by ICP-MS, and was determined to be adequately homogenous (82% for As, Cu, Mn, Pb, Sr and Zn but poor for other elements, where sample preparation strategies 'no sample preparation' and 'dried in a desiccator' had the best extraction recoveries. Cryogenic freezing procedures had a significantly (p lichens. Biotransformation over a period of a month is suspected for most elements, with the exception of Sr and Zn, where changes in the fractionation patterns were statistically significant (p < 0.05), indicating the need for minimal delay in sample cleaning and preservation when species fractionation patterns are of interest. This study also shows that the assumption that species stability can be ensured through cryopreservation and freeze drying techniques needs to be revisited.

  9. Music Therapy as Procedural Support for Young Children Undergoing Immunizations: A Randomized Controlled Study.

    Science.gov (United States)

    Yinger, Olivia Swedberg

    2016-01-01

    Children undergoing routine immunizations frequently experience severe distress, which may be improved through music therapy as procedural support. The purpose of this study was to examine effects of live, cognitive-behavioral music therapy during immunizations on (a) the behaviors of children, their parents, and their nurses; and (b) parental perceptions. Participants were children between the ages of 4 and 6 years (N = 58) who underwent immunizations, their parents (N = 62), and the nurses who administered the procedure (N = 19). Parent/child dyads were randomly assigned to receive music therapy (n = 29) or standard care (n = 29) during their immunization. Afterward, each parent rated their child's level of pain and the distress their child experienced compared to previous medical experiences. All procedures were videotaped and later viewed by trained observers, who classified child, parent, and nurse behaviors using the categories of the Child-Adult Medical Procedure Interaction Scale-Revised (CAMPIS-R). Significant differences between the music therapy and control groups were found in rates of child coping and distress behaviors and parent distress-promoting behaviors. Parents of children who received music therapy reported that their child's level of distress was less than during previous medical experiences, whereas parents of children in the control group reported that their child's level of distress was greater. No significant differences between groups were found in parents' ratings of children's pain or in rates of nurse behavior. Live, cognitive-behavioral music therapy has potential benefits for young children and their parents during immunizations. © the American Music Therapy Association 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  10. Calculating sample sizes for cluster randomized trials: we can keep it simple and efficient !

    NARCIS (Netherlands)

    van Breukelen, Gerard J.P.; Candel, Math J.J.M.

    2012-01-01

    Objective: Simple guidelines for efficient sample sizes in cluster randomized trials with unknown intraclass correlation and varying cluster sizes. Methods: A simple equation is given for the optimal number of clusters and sample size per cluster. Here, optimal means maximizing power for a given

  11. Multistage point relascope and randomized branch sampling for downed coarse woody debris estimation

    Science.gov (United States)

    Jeffrey H. Gove; Mark J. Ducey; Harry T. Valentine

    2002-01-01

    New sampling methods have recently been introduced that allow estimation of downed coarse woody debris using an angle gauge, or relascope. The theory behind these methods is based on sampling straight pieces of downed coarse woody debris. When pieces deviate from this ideal situation, auxillary methods must be employed. We describe a two-stage procedure where the...

  12. Survey research with a random digit dial national mobile phone sample in Ghana: Methods and sample quality

    Science.gov (United States)

    Sefa, Eunice; Adimazoya, Edward Akolgo; Yartey, Emmanuel; Lenzi, Rachel; Tarpo, Cindy; Heward-Mills, Nii Lante; Lew, Katherine; Ampeh, Yvonne

    2018-01-01

    Introduction Generating a nationally representative sample in low and middle income countries typically requires resource-intensive household level sampling with door-to-door data collection. High mobile phone penetration rates in developing countries provide new opportunities for alternative sampling and data collection methods, but there is limited information about response rates and sample biases in coverage and nonresponse using these methods. We utilized data from an interactive voice response, random-digit dial, national mobile phone survey in Ghana to calculate standardized response rates and assess representativeness of the obtained sample. Materials and methods The survey methodology was piloted in two rounds of data collection. The final survey included 18 demographic, media exposure, and health behavior questions. Call outcomes and response rates were calculated according to the American Association of Public Opinion Research guidelines. Sample characteristics, productivity, and costs per interview were calculated. Representativeness was assessed by comparing data to the Ghana Demographic and Health Survey and the National Population and Housing Census. Results The survey was fielded during a 27-day period in February-March 2017. There were 9,469 completed interviews and 3,547 partial interviews. Response, cooperation, refusal, and contact rates were 31%, 81%, 7%, and 39% respectively. Twenty-three calls were dialed to produce an eligible contact: nonresponse was substantial due to the automated calling system and dialing of many unassigned or non-working numbers. Younger, urban, better educated, and male respondents were overrepresented in the sample. Conclusions The innovative mobile phone data collection methodology yielded a large sample in a relatively short period. Response rates were comparable to other surveys, although substantial coverage bias resulted from fewer women, rural, and older residents completing the mobile phone survey in

  13. A new selective enrichment procedure for isolating Pasteurella multocida from avian and environmental samples

    Science.gov (United States)

    Moore, M.K.; Cicnjak-Chubbs, L.; Gates, R.J.

    1994-01-01

    A selective enrichment procedure, using two new selective media, was developed to isolate Pasteurella multocida from wild birds and environmental samples. These media were developed by testing 15 selective agents with six isolates of P. multocida from wild avian origin and seven other bacteria representing genera frequently found in environmental and avian samples. The resulting media—Pasteurella multocida selective enrichment broth and Pasteurella multocida selective agar—consisted of a blood agar medium at pH 10 containing gentamicin, potassium tellurite, and amphotericin B. Media were tested to determine: 1) selectivity when attempting isolation from pond water and avian carcasses, 2) sensitivity for detection of low numbers of P. multocida from pure and mixed cultures, 3) host range specificity of the media, and 4) performance compared with standard blood agar. With the new selective enrichment procedure, P. multocida was isolated from inoculated (60 organisms/ml) pond water 84% of the time, whereas when standard blood agar was used, the recovery rate was 0%.

  14. Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992

    Science.gov (United States)

    Manning, T.K.; Smith, K.E.; Wood, C.D.; Williams, J.B.

    1994-01-01

    Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

  15. A Randomized Controlled Trial Comparing Intranasal Midazolam and Chloral Hydrate for Procedural Sedation in Children.

    Science.gov (United States)

    Stephen, Marie Christy Sharafine; Mathew, John; Varghese, Ajoy Mathew; Kurien, Mary; Mathew, George Ani

    2015-12-01

    To evaluate the efficacy and safety of intranasal midazolam and chloral hydrate syrup for procedural sedation in children. Prospective randomized placebo-controlled trial (double blind, double dummy). Tertiary care hospital over 18 months. Eighty-two children, 1 to 6 years old, undergoing auditory brainstem response testing were randomized to receive either intranasal midazolam with oral placebo or chloral hydrate syrup with placebo nasal spray. Intranasal midazolam was delivered at 0.5 mg/kg (100 mcg per spray) and oral syrup at 50 mg/kg. Children not sedated at 30 minutes had a second dose at half the initial dose. The primary outcomes measured were safety and efficacy. Secondary outcomes were time to onset of sedation, parental separation, nature of parental separation, parental satisfaction, audiologist's satisfaction, time to recovery, and number of attempts. Forty-one children were in each group, and no major adverse events were noted. The chloral hydrate group showed earlier onset of sedation (66%) compared with the intranasal midazolam group (33%). Significant difference in time to recovery was noted in the chloral hydrate group (78 minutes) versus the intranasal midazolam group (108 minutes). The parents' and audiologist's satisfaction was higher for chloral hydrate (95% and 75%) than for intranasal midazolam (49% and 29%, respectively). Overall, sedation was 95% with chloral hydrate versus 51% with intranasal midazolam. Both drugs maintained sedation. Intranasal midazolam and chloral hydrate are both safe and efficacious for pediatric procedural sedation. Chloral hydrate was superior to intranasal midazolam, with an earlier time to onset of sedation, a faster recovery, better satisfaction among parents and the audiologist, and successful sedation. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  16. Enhanced procedural blank control for organic geochemical studies of critical sample material.

    Science.gov (United States)

    Leider, A; Schumacher, T C; Hallmann, C

    2016-09-01

    Organic contamination of sedimentary rocks can produce artefacts in studies of hydrocarbon composition, and this can have significant negative consequences for interpretations of the geobiological record. False positives - that is cases of non-syngenetic hydrocarbon biomarkers - are common in Precambrian studies, and significant challenges persist despite the intensive effort devoted to these studies. Efforts to standardize the 'burden of proof' for distinguishing between contamination and syngenetic material have to date failed to yield a simple or universal protocol, yet the need remains great, as both bitumen-lean rocks and bitumen-rich samples can be vulnerable to the accumulation of false-positive signals. In an effort to determine the best approach to quality control, we tested the capability of different blank materials to collect ambient contamination by assessing their capacity to adsorb hydrocarbons during storage in plastic bags and found that commonly used Quartz sand does not provide an adequate measure of storage- or laboratory-induced contamination. Brick blanks, having the advantage that they can parallel rock samples even during the sawing process, are characterized by similar poor adsorption properties. Primarily steered by mineralogy, organic carbon content and surface area, model-black shales can adsorb up to 20 times more contaminants than sand blanks and up to 200 times more contaminants than organic-free model-carbonates. This observation provides an explanation for reports and observations of seemingly systematic stratigraphic variation of contaminants, but mostly should raise awareness for the evaluation of procedural blanks, in particular of sample-to-blank ratios, when studying bitumen-lean rock samples of varying lithologies. Additionally, differences between the hydrocarbon profiles in plastic bags and the hydrocarbon signatures transferred to blank materials emphasize difficulties in the unequivocal detection of contamination sources

  17. Stratified random sampling for estimating billing accuracy in health care systems.

    Science.gov (United States)

    Buddhakulsomsiri, Jirachai; Parthanadee, Parthana

    2008-03-01

    This paper presents a stratified random sampling plan for estimating accuracy of bill processing performance for the health care bills submitted to third party payers in health care systems. Bill processing accuracy is estimated with two measures: percent accuracy and total dollar accuracy. Difficulties in constructing a sampling plan arise when the population strata structure is unknown, and when the two measures require different sampling schemes. To efficiently utilize sample resource, the sampling plan is designed to effectively estimate both measures from the same sample. The sampling plan features a simple but efficient strata construction method, called rectangular method, and two accuracy estimation methods, one for each measure. The sampling plan is tested on actual populations from an insurance company. Accuracy estimates obtained are then used to compare the rectangular method to other potential clustering methods for strata construction, and compare the accuracy estimation methods to other eligible methods. Computational study results show effectiveness of the proposed sampling plan.

  18. Hemostasis pad combined with compression device after transradial coronary procedures: A randomized controlled trial.

    Science.gov (United States)

    Kang, Si-Hyuck; Han, Donghoon; Kim, Sehun; Yoon, Chang-Hwan; Park, Jin-Joo; Suh, Jung-Won; Cho, Young-Seok; Youn, Tae-Jin; Chae, In-Ho

    2017-01-01

    Arterial access and hemostasis are important processes during percutaneous coronary procedures. In this study, we tested if the use of chitosan-based pads on top of compression devices could improve hemostasis efficacy compared with compression devices alone after transradial coronary angiography or interventions. This study was a single-center open-label randomized controlled trial. Patients who underwent coronary angiography or intervention with the transradial approach were randomly assigned to the study (compression device and a chitosan-based pad) or control (compression devices alone) group in a 2:1 fashion. The primary endpoint was time to hemostasis, categorized into ≤5, 6-10, 11-20, and >20 minutes. Between April and July 2016, 95 patients were enrolled (59 were assigned to the study arm and 36 to the control arm). Time to hemostasis, the primary endpoint, was significantly lower in the study group than in the control group (phemostasis pad in combination with rotatory compression devices is a safe and effective hemostasis strategy after radial artery access. ClinicalTrials.gov NCT02954029.

  19. Hemostasis pad combined with compression device after transradial coronary procedures: A randomized controlled trial.

    Directory of Open Access Journals (Sweden)

    Si-Hyuck Kang

    Full Text Available Arterial access and hemostasis are important processes during percutaneous coronary procedures. In this study, we tested if the use of chitosan-based pads on top of compression devices could improve hemostasis efficacy compared with compression devices alone after transradial coronary angiography or interventions.This study was a single-center open-label randomized controlled trial. Patients who underwent coronary angiography or intervention with the transradial approach were randomly assigned to the study (compression device and a chitosan-based pad or control (compression devices alone group in a 2:1 fashion. The primary endpoint was time to hemostasis, categorized into ≤5, 6-10, 11-20, and >20 minutes.Between April and July 2016, 95 patients were enrolled (59 were assigned to the study arm and 36 to the control arm. Time to hemostasis, the primary endpoint, was significantly lower in the study group than in the control group (p<0.001. Both groups showed low rates of vascular complications.This study suggests that the use of a hemostasis pad in combination with rotatory compression devices is a safe and effective hemostasis strategy after radial artery access.ClinicalTrials.gov NCT02954029.

  20. Use of protein: creatinine ratio in a random spot urine sample for predicting significant proteinuria in diabetes mellitus.

    Science.gov (United States)

    Yadav, B K; Adhikari, S; Gyawali, P; Shrestha, R; Poudel, B; Khanal, M

    2010-06-01

    Present study was undertaken during a period of 6 months (September 2008-February 2009) to see an correlation of 24 hours urine protein estimation with random spot protein-creatinine (P:C) ratio among a diabetic patients. The study comprised of 144 patients aged 30-70 years, recruited from Kantipur hospital, Kathmandu. The 24-hr urine sample was collected, followed by spot random urine sample. Both samples were analyzed for protein and creatinine excretion. An informed consent was taken from all participants. Sixteen inadequately collected urine samples as defined by (predicted creatinine--measured creatinine)/predicted creatinine > 0.2 were excluded from analysis. The Spearman's rank correlation between the spot urine P:C ratio and 24-hr total protein were performed by the Statistical Package for Social Service. At the P:C ratio cutoff of 0.15 and reference method (24-hr urine protein) cutoff of 150 mg/day, the correlation coefficient was found to be 0.892 (p urine collection but the cutoff should be carefully selected for different patients group under different laboratory procedures and settings.

  1. Protocol: MYTHBUSTERS: a universal procedure for sample preparation for mass spectrometry.

    Science.gov (United States)

    Drabik, Anna; Ner-Kluza, Joanna; Bodzon-Kulakowska, Anna; Suder, Piotr

    Improvements in proteomic strategies from the development of new and robust separation and identification techniques have led to broad applications of proteomics to solve numerous biological questions. For all analyses, sample quality is unquestionably a critical factor; therefore protein extraction is of outmost importance. The ideal extraction method should provide reproducible spectra of the most comprehensive repertoire of proteins, while minimizing sample loss and degradation. It is already known that to capture the whole proteome is an unenforceable task. Many protein extraction protocols have been described, yet there is no "one perfect procedure" taking into account the vast diversity of biological and physical properties of proteins, including their charge, size, hydrophobicity, interactions and sub-cellular localization. The research presented here reflects the main obstacle occurring in proteomic experimental design; i.e. the lack of reproducibility as a result of alterations in protein extraction methods. We have performed a series of experiments, aimed towards identification of the aptamer-binding partners in cancerous cells. Aptamers are chemically synthesized, short, single-stranded nucleic acids with a strictly defined three-dimensional structure, which allows them to interact with a target molecule with high affinity. The low immunogenicity and cellular- targeting properties of aptamers might facilitate design of suitable drugs with low side-effects. Aptamers can be used for identification of molecules associated with a pathogenic state of a cell. Aptamers can be considered as a powerful tool, since they possess unique properties to benefit cancer diagnosis, prevention and treatment. We have used different types of protein extraction methods prior to analyses of complex biological samples by mass spectrometry, based on slight changes of homogenization buffers, and have observed the changes in the identified compounds. These results should prove to

  2. Critical evaluation of distillation procedure for the determination of methylmercury in soil samples.

    Science.gov (United States)

    Perez, Pablo A; Hintelman, Holger; Quiroz, Waldo; Bravo, Manuel A

    2017-11-01

    In the present work, the efficiency of distillation process for extracting monomethylmercury (MMHg) from soil samples was studied and optimized using an experimental design methodology. The influence of soil composition on MMHg extraction was evaluated by testing of four soil samples with different geochemical characteristics. Optimization suggested that the acid concentration and the duration of the distillation process were most significant and the most favorable conditions, established as a compromise for the studied soils, were determined to be a 70 min distillation using an 0.2 M acid. Corresponding limits of detection (LOD) and quantification (LOQ) were 0.21 and 0.7 pg absolute, respectively. The optimized methodology was applied with satisfactory results to soil samples and was compared to a reference methodology based on isotopic dilution analysis followed by gas chromatography-inductively coupled plasma mass spectrometry (IDA-GC-ICP-MS). Using the optimized conditions, recoveries ranged from 82 to 98%, which is an increase of 9-34% relative to the previously used standard operating procedure. Finally, the validated methodology was applied to quantify MMHg in soils collected from different sites impacted by coal fired power plants in the north-central zone of Chile, measuring MMHg concentrations ranging from 0.091 to 2.8 ng g-1. These data are to the best of our knowledge the first MMHg measurements reported for Chile. Copyright © 2017 Elsevier Ltd. All rights reserved.

  3. Rapid Microwave Digestion Procedures for the Elemental Analysis of Alloy and Slag Samples of Smelted Ocean Bed Polymetallic Nodules

    Directory of Open Access Journals (Sweden)

    Kumari Smita

    2013-01-01

    Full Text Available The use of microwave digester for digestion of alloy and slag samples of smelted ocean bed polymetallic nodules has permitted the complete digestion of samples, thereby replacing the tedious classical methods of digestion of samples. The digestion procedure includes two acid-closed digestions of samples in a microwave oven. Owing to the hazardous nature of perchloric acid, it was not used in developed digestion procedure. Digested sample solutions were analyzed for concentrations of various radicals and the effectiveness of the developed digestion methodology was tested using certified reference materials. It was found that the developed method is giving results comparable with that obtained from conventionally digested samples. In this digestion procedure, time required for digestion of samples was reduced to about 1 hour only from 8-9 hours of conventional digestion.

  4. Impact of Sample Type and DNA Isolation Procedure on Genomic Inference of Microbiome Composition

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær; Bergmark, Lasse; Munk, Patrick

    2016-01-01

    was dependent on inherent specimen properties as well as DNA extraction method. We further show that bead beating or enzymatic treatment can increase the extraction of DNA from Gram-positive bacteria. Final DNA quantities could be increased by isolating DNA from a larger volume of cell lysate than...... resistance from different reservoirs. Here, we compare in a stepwise approach a total of eight commercially available DNA extraction kits and 16 procedures based on these for three specimentypes (human feces, pig feces, and hospital sewage). We assess DNA extraction using spike-in controls and different...... types of beads for bead beating, facilitating cell lysis. We evaluate DNA concentration, purity, and stability and microbial community composition using 16S rRNA gene sequencing and for selected samples using shotgun metagenomic sequencing. Our results suggest that inferred community composition...

  5. Improved extraction procedures for polychlorinated biphenyls in solid samples with aqueous sodium hydroxide under autoclave conditions.

    Science.gov (United States)

    Akimoto, Y; Inouye, Y

    2000-03-01

    The efficacy of the extraction of polychlorinated biphenyls (PCBs) from varnish-infiltrated insulating papers as a model of solid materials with an aqueous sodium hydroxide (NaOH) by autoclaving at 121 degrees C for 30 min was compared with those for the conventional procedures, i.e., saponification with 1 N ethanolic NaOH in a boiling water bath for 60 min and extraction with benzene in a Soxhlet apparatus. The newly invented autoclaving method was found to be superior to the conventional ones, yielding approximately 5- to 6-fold cumulative PCB congeners without being accompanied by extended decomposition. Therefore, the autoclave-based sample treatment is recommended for more accurate determination of PCBs in the case of PCB-impregnated solid materials such as hardened oils and resin-coated or -infiltrated papers instead of being treated conventionally.

  6. Investigation of propofol renal elimination by HPLC using supported liquid membrane procedure for sample preparation.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Kalityński, Rafał; Trocewicz, Jerzy; Nestorowicz, Andrzej; Fijałkowska, Anna; Trela-Stachurska, Katarzyna

    2002-10-01

    One of the least explored subjects in the research on the metabolism of a widely used anaesthetic, propofol, is its excretion in an unchanged form. According to literature, the estimated percentage of applied propofol eliminated intact via kidneys is lower than 0.3%. The present study shows the amount of propofol excreted in an unchanged form with urine collected during the first 48 h after anaesthesia in five patients undergoing elective intracranial procedures. The drug was concentrated and selectively isolated from urine samples by supported liquid membrane technique and determined by HPLC with fluorescence detection. The amount of unchanged propofol eliminated with urine was approximately (0.004 +/- 0.002)% of the total applied dose. The obtained results may suggest that propofol in an unchanged form is not excreted by kidneys at all provided that all propofol determined in presented study originated from conjugates hydrolysis. Copyright 2002 John Wiley & Sons, Ltd.

  7. TVT-Secur (Hammock) versus TVT-Obturator: a randomized trial of suburethral sling operative procedures.

    Science.gov (United States)

    Hota, Lekha S; Hanaway, Katherine; Hacker, Michele R; Disciullo, Anthony; Elkadry, Eman; Dramitinos, Patricia; Shapiro, Alexander; Ferzandi, Tanaz; Rosenblatt, Peter L

    2012-01-01

    This study aimed to compare TVT-Secur (TVT-S) and TVT-Obturator (TVT-O) suburethral slings for treatment of stress urinary incontinence (SUI). This was a single-center, nonblinded, randomized trial of women with SUI who were randomized to TVT-S or TVT-O from May 2007 to April 2009. The primary outcome, SUI on cough stress test (CST), and quality-of-life and symptom questionnaires (Pelvic Floor Distress Inventory [PFDI-20] and Pelvic Floor Impact Questionnaire [PFIQ-7]) were assessed at 12 weeks and 1 year. Forty-three women were randomized to TVT-S and 44 to TVT-O. There were no differences in median baseline PFDI-20 and PFIQ-7. Twenty-two (52.4%) of 42 participants randomized to TVT-S had a positive CST result at evaluation after 12 weeks or 1 year, whereas 4 (9.1%) of the 44 in the TVT-O group had a positive CST result. The intent-to-treat analysis showed that the risk of a positive CST result was 6 times higher after TVT-S than TVT-O (risk ratio, 6.0; 95% confidence interval [CI], 2.3-16.0). Among women not lost to follow-up, the risk ratio for a positive CST result after TVT-S compared with TVT-O was 17.9 (95% CI, 2.5-128.0) at 12 weeks and 3.5 (95% CI, 1.1-11.0) at 1 year. Both TVT-S and TVT-O resulted in improved quality of life and symptoms at 12 weeks. There was no difference between the groups for PFDI-20 (P = 0.40) or PFIQ-7 (P = 0.43). A similar pattern was seen at 1 year (P = 0.85 and P = 0.36). The TVT-S seems to have a higher risk of positive postoperative CST result; however, the procedures result in similar improvements in quality of life and symptoms.

  8. Estimation of Sensitive Proportion by Randomized Response Data in Successive Sampling

    Directory of Open Access Journals (Sweden)

    Bo Yu

    2015-01-01

    Full Text Available This paper considers the problem of estimation for binomial proportions of sensitive or stigmatizing attributes in the population of interest. Randomized response techniques are suggested for protecting the privacy of respondents and reducing the response bias while eliciting information on sensitive attributes. In many sensitive question surveys, the same population is often sampled repeatedly on each occasion. In this paper, we apply successive sampling scheme to improve the estimation of the sensitive proportion on current occasion.

  9. Nonpharmacological techniques to reduce pain in preterm infants who receive heel-lance procedure: a randomized controlled trial.

    Science.gov (United States)

    Bergomi, Piera; Chieppi, Michele; Maini, Antonella; Mugnos, Tiziana; Spotti, Debora; Tzialla, Chrisoulle; Scudeller, Luigia

    2014-01-01

    The heel-lance (HL) method for blood collection from the newborn is controversial for the pain it causes. This is the first randomized controlled trial on the management and reduction of pain using the music of Wolfgang Amadeus Mozart ("Sonata K. 448") in premature infants hospitalized in a neonatal intensive care unit (NICU). This study has compared nonpharmacological techniques with standard procedure for reducing pain during HL procedure. Thirty-five premature infants were enrolled, each for 3 HL procedures, of which each was randomized to 1 of the 3 study arms. Arms were then compared in terms of the Premature Infant Pain Profile (PIPP) changes by analysis of variance (ANOVA). One hundred five HL procedures were available for analysis (35 standard procedure, 35 music, 35 glucose). Median baseline PIPP was 3, and median PIPP after the HL procedure was 5. PIPP scale change was +3 in the control arm, +1 in the glucose arm, +2 in the music arm (p = .008). Both glucose and music were safe and effective in limiting pain increase when compared to standard procedure in HL procedures in preterm infants.

  10. Random sampling of elementary flux modes in large-scale metabolic networks.

    Science.gov (United States)

    Machado, Daniel; Soons, Zita; Patil, Kiran Raosaheb; Ferreira, Eugénio C; Rocha, Isabel

    2012-09-15

    The description of a metabolic network in terms of elementary (flux) modes (EMs) provides an important framework for metabolic pathway analysis. However, their application to large networks has been hampered by the combinatorial explosion in the number of modes. In this work, we develop a method for generating random samples of EMs without computing the whole set. Our algorithm is an adaptation of the canonical basis approach, where we add an additional filtering step which, at each iteration, selects a random subset of the new combinations of modes. In order to obtain an unbiased sample, all candidates are assigned the same probability of getting selected. This approach avoids the exponential growth of the number of modes during computation, thus generating a random sample of the complete set of EMs within reasonable time. We generated samples of different sizes for a metabolic network of Escherichia coli, and observed that they preserve several properties of the full EM set. It is also shown that EM sampling can be used for rational strain design. A well distributed sample, that is representative of the complete set of EMs, should be suitable to most EM-based methods for analysis and optimization of metabolic networks. Source code for a cross-platform implementation in Python is freely available at http://code.google.com/p/emsampler. dmachado@deb.uminho.pt Supplementary data are available at Bioinformatics online.

  11. Power and sample size calculations for Mendelian randomization studies using one genetic instrument.

    Science.gov (United States)

    Freeman, Guy; Cowling, Benjamin J; Schooling, C Mary

    2013-08-01

    Mendelian randomization, which is instrumental variable analysis using genetic variants as instruments, is an increasingly popular method of making causal inferences from observational studies. In order to design efficient Mendelian randomization studies, it is essential to calculate the sample sizes required. We present formulas for calculating the power of a Mendelian randomization study using one genetic instrument to detect an effect of a given size, and the minimum sample size required to detect effects for given levels of significance and power, using asymptotic statistical theory. We apply the formulas to some example data and compare the results with those from simulation methods. Power and sample size calculations using these formulas should be more straightforward to carry out than simulation approaches. These formulas make explicit that the sample size needed for Mendelian randomization study is inversely proportional to the square of the correlation between the genetic instrument and the exposure and proportional to the residual variance of the outcome after removing the effect of the exposure, as well as inversely proportional to the square of the effect size.

  12. Sampling versus Random Binning for Multiple Descriptions of a Bandlimited Source

    DEFF Research Database (Denmark)

    Mashiach, Adam; Østergaard, Jan; Zamir, Ram

    2013-01-01

    Random binning is an efficient, yet complex, coding technique for the symmetric L-description source coding problem. We propose an alternative approach, that uses the quantized samples of a bandlimited source as "descriptions". By the Nyquist condition, the source can be reconstructed if enough s...

  13. Recidivism among Child Sexual Abusers: Initial Results of a 13-Year Longitudinal Random Sample

    Science.gov (United States)

    Patrick, Steven; Marsh, Robert

    2009-01-01

    In the initial analysis of data from a random sample of all those charged with child sexual abuse in Idaho over a 13-year period, only one predictive variable was found that related to recidivism of those convicted. Variables such as ethnicity, relationship, gender, and age differences did not show a significant or even large association with…

  14. HABITAT ASSESSMENT USING A RANDOM PROBABILITY BASED SAMPLING DESIGN: ESCAMBIA RIVER DELTA, FLORIDA

    Science.gov (United States)

    Smith, Lisa M., Darrin D. Dantin and Steve Jordan. In press. Habitat Assessment Using a Random Probability Based Sampling Design: Escambia River Delta, Florida (Abstract). To be presented at the SWS/GERS Fall Joint Society Meeting: Communication and Collaboration: Coastal Systems...

  15. Reinforcing Sampling Distributions through a Randomization-Based Activity for Introducing ANOVA

    Science.gov (United States)

    Taylor, Laura; Doehler, Kirsten

    2015-01-01

    This paper examines the use of a randomization-based activity to introduce the ANOVA F-test to students. The two main goals of this activity are to successfully teach students to comprehend ANOVA F-tests and to increase student comprehension of sampling distributions. Four sections of students in an advanced introductory statistics course…

  16. Rapid and efficient filtration-based procedure for separation and safe analysis of CBRN mixed samples.

    Directory of Open Access Journals (Sweden)

    Mostafa Bentahir

    Full Text Available Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV, Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA and pinacolyl methylphophonic acid (PMPA were used as VX and soman (GD nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm and three RNA extraction methods (Invisorb, EZ1 and Nuclisens were compared. RNA (MS2 and DNA (AcNPV quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR. Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  17. Rapid and Efficient Filtration-Based Procedure for Separation and Safe Analysis of CBRN Mixed Samples

    Science.gov (United States)

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  18. Flexible sampling large-scale social networks by self-adjustable random walk

    Science.gov (United States)

    Xu, Xiao-Ke; Zhu, Jonathan J. H.

    2016-12-01

    Online social networks (OSNs) have become an increasingly attractive gold mine for academic and commercial researchers. However, research on OSNs faces a number of difficult challenges. One bottleneck lies in the massive quantity and often unavailability of OSN population data. Sampling perhaps becomes the only feasible solution to the problems. How to draw samples that can represent the underlying OSNs has remained a formidable task because of a number of conceptual and methodological reasons. Especially, most of the empirically-driven studies on network sampling are confined to simulated data or sub-graph data, which are fundamentally different from real and complete-graph OSNs. In the current study, we propose a flexible sampling method, called Self-Adjustable Random Walk (SARW), and test it against with the population data of a real large-scale OSN. We evaluate the strengths of the sampling method in comparison with four prevailing methods, including uniform, breadth-first search (BFS), random walk (RW), and revised RW (i.e., MHRW) sampling. We try to mix both induced-edge and external-edge information of sampled nodes together in the same sampling process. Our results show that the SARW sampling method has been able to generate unbiased samples of OSNs with maximal precision and minimal cost. The study is helpful for the practice of OSN research by providing a highly needed sampling tools, for the methodological development of large-scale network sampling by comparative evaluations of existing sampling methods, and for the theoretical understanding of human networks by highlighting discrepancies and contradictions between existing knowledge/assumptions of large-scale real OSN data.

  19. Sample size calculations for micro-randomized trials in mHealth.

    Science.gov (United States)

    Liao, Peng; Klasnja, Predrag; Tewari, Ambuj; Murphy, Susan A

    2016-05-30

    The use and development of mobile interventions are experiencing rapid growth. In "just-in-time" mobile interventions, treatments are provided via a mobile device, and they are intended to help an individual make healthy decisions 'in the moment,' and thus have a proximal, near future impact. Currently, the development of mobile interventions is proceeding at a much faster pace than that of associated data science methods. A first step toward developing data-based methods is to provide an experimental design for testing the proximal effects of these just-in-time treatments. In this paper, we propose a 'micro-randomized' trial design for this purpose. In a micro-randomized trial, treatments are sequentially randomized throughout the conduct of the study, with the result that each participant may be randomized at the 100s or 1000s of occasions at which a treatment might be provided. Further, we develop a test statistic for assessing the proximal effect of a treatment as well as an associated sample size calculator. We conduct simulation evaluations of the sample size calculator in various settings. Rules of thumb that might be used in designing a micro-randomized trial are discussed. This work is motivated by our collaboration on the HeartSteps mobile application designed to increase physical activity. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  20. Generalized SAMPLE SIZE Determination Formulas for Investigating Contextual Effects by a Three-Level Random Intercept Model.

    Science.gov (United States)

    Usami, Satoshi

    2017-03-01

    Behavioral and psychological researchers have shown strong interests in investigating contextual effects (i.e., the influences of combinations of individual- and group-level predictors on individual-level outcomes). The present research provides generalized formulas for determining the sample size needed in investigating contextual effects according to the desired level of statistical power as well as width of confidence interval. These formulas are derived within a three-level random intercept model that includes one predictor/contextual variable at each level to simultaneously cover various kinds of contextual effects that researchers can show interest. The relative influences of indices included in the formulas on the standard errors of contextual effects estimates are investigated with the aim of further simplifying sample size determination procedures. In addition, simulation studies are performed to investigate finite sample behavior of calculated statistical power, showing that estimated sample sizes based on derived formulas can be both positively and negatively biased due to complex effects of unreliability of contextual variables, multicollinearity, and violation of assumption regarding the known variances. Thus, it is advisable to compare estimated sample sizes under various specifications of indices and to evaluate its potential bias, as illustrated in the example.

  1. Occupational position and its relation to mental distress in a random sample of Danish residents

    DEFF Research Database (Denmark)

    Rugulies, Reiner Ernst; Madsen, Ida E H; Nielsen, Maj Britt D

    2010-01-01

    somatization symptoms (OR = 6.28, 95% CI = 1.39-28.46). CONCLUSIONS: Unskilled manual workers, the unemployed, and, to a lesser extent, the low-grade self-employed showed an increased level of mental distress. Activities to promote mental health in the Danish population should be directed toward these groups.......PURPOSE: To analyze the distribution of depressive, anxiety, and somatization symptoms across different occupational positions in a random sample of Danish residents. METHODS: The study sample consisted of 591 Danish residents (50% women), aged 20-65, drawn from an age- and gender-stratified random...... sample of the Danish population. Participants filled out a survey that included the 92 item version of the Hopkins Symptom Checklist (SCL-92). We categorized occupational position into seven groups: high- and low-grade non-manual workers, skilled and unskilled manual workers, high- and low-grade self...

  2. Assessment of proteinuria by using protein: creatinine index in random urine sample.

    Science.gov (United States)

    Khan, Dilshad Ahmed; Ahmad, Tariq Mahmood; Qureshil, Ayaz Hussain; Halim, Abdul; Ahmad, Mumtaz; Afzal, Saeed

    2005-10-01

    To assess the quantitative measurement of proteinuria by using random urine protein:creatinine index/ratio in comparison with 24 hours urinary protein excretion in patients of renal diseases having normal glomerular filtration rate. One hundred and thirty patients, 94 males and 36 females, with an age range of 5 to 60 years; having proteinuria of more than 150 mg/day were included in this study. Qualitative urinary protein estimation was done on random urine specimen by dipstick. Quantitative measurement of protein in the random and 24 hours urine specimens were carried out by a method based on the formation of a red complex of protein with pyrogallal red in acid medium on Micro lab 200 (Merck). Estimation of creatinine was done on Selectra -2 (Merck) by Jaffe's reaction. The urine protein:creatinine index and ratio were calculated by dividing the urine protein concentration (mg/L) by urine creatinine concentration (mmol/L) multilplied by 10 and mg/mg respectively. The protein:creatinine index and ratio of more than 140 and 0.18 respectively in a random urine sample indicated pathological proteinuria. An excellent correlation (r=0.96) was found between random urine protein:creatinine index/ratio and standard 24 hours urinary protein excretion in these patients (pprotein:creatinine index in random urine is a convenient, quick and reliable method of estimation of proteinuria as compared to 24 hours of urinary protein excretion for diagnosis and monitoring of renal diseases in our medical setup.

  3. Generalized essential energy space random walks to more effectively accelerate solute sampling in aqueous environment.

    Science.gov (United States)

    Lv, Chao; Zheng, Lianqing; Yang, Wei

    2012-01-28

    Molecular dynamics sampling can be enhanced via the promoting of potential energy fluctuations, for instance, based on a Hamiltonian modified with the addition of a potential-energy-dependent biasing term. To overcome the diffusion sampling issue, which reveals the fact that enlargement of event-irrelevant energy fluctuations may abolish sampling efficiency, the essential energy space random walk (EESRW) approach was proposed earlier. To more effectively accelerate the sampling of solute conformations in aqueous environment, in the current work, we generalized the EESRW method to a two-dimension-EESRW (2D-EESRW) strategy. Specifically, the essential internal energy component of a focused region and the essential interaction energy component between the focused region and the environmental region are employed to define the two-dimensional essential energy space. This proposal is motivated by the general observation that in different conformational events, the two essential energy components have distinctive interplays. Model studies on the alanine dipeptide and the aspartate-arginine peptide demonstrate sampling improvement over the original one-dimension-EESRW strategy; with the same biasing level, the present generalization allows more effective acceleration of the sampling of conformational transitions in aqueous solution. The 2D-EESRW generalization is readily extended to higher dimension schemes and employed in more advanced enhanced-sampling schemes, such as the recent orthogonal space random walk method. © 2012 American Institute of Physics

  4. Multilayer pixel super-resolution lensless in-line holographic microscope with random sample movement.

    Science.gov (United States)

    Wang, Mingjun; Feng, Shaodong; Wu, Jigang

    2017-10-06

    We report a multilayer lensless in-line holographic microscope (LIHM) with improved imaging resolution by using the pixel super-resolution technique and random sample movement. In our imaging system, a laser beam illuminated the sample and a CMOS imaging sensor located behind the sample recorded the in-line hologram for image reconstruction. During the imaging process, the sample was moved by hand randomly and the in-line holograms were acquired sequentially. Then the sample image was reconstructed from an enhanced-resolution hologram obtained from multiple low-resolution in-line holograms by applying the pixel super-resolution (PSR) technique. We studied the resolution enhancement effects by using the U.S. Air Force (USAF) target as the sample in numerical simulation and experiment. We also showed that multilayer pixel super-resolution images can be obtained by imaging a triple-layer sample made with the filamentous algae on the middle layer and microspheres with diameter of 2 μm on the top and bottom layers. Our pixel super-resolution LIHM provides a compact and low-cost solution for microscopic imaging and is promising for many biomedical applications.

  5. Concept formation based on value relations evaluated with a matching-to-sample procedure.

    Science.gov (United States)

    Pérez-González, Luis Antonio

    2008-01-01

    To study concept formation based on relations, adults were taught and tested on complex discriminations involving figures that varied in colors, forms, and orientations. In Experiment 1, participants learned to select figures with values A1 and B1 or values B1 and C1; thereafter, they consistently selected figures with values A1 and C1. Selections were based on the relations among the values, rather than on perceptual properties. Experiments 2 and 3 studied generalization with a matching-to-sample procedure: participants learned to select "yes" in the presence of the positive figures, such as A1B1, and "no" in the presence of the negative figures. Thereafter, all figures that resulted from combining three values of the three relevant dimensions were probed. Participants typically selected "yes" in the presence of the novel figures that had two or three values related to one another and selected "no" in the presence of the other figures. Finally, two participants learned a simple discrimination. They did not generalize responding to other figures with the same values; instead, their performance in the generalization test remained almost unaltered. Thus, the concept based on relations was not affected by the simple discrimination. These results showed some unique properties of the concept based on relations and challenge previous theories on concept formation.

  6. 76 FR 65953 - CBP Audit Procedures; Use of Sampling Methods and Offsetting of Overpayments and Over-Declarations

    Science.gov (United States)

    2011-10-25

    ... projection will not produce accurate audits unless an audit takes into account the specifics for each...-AD65 (Formerly RIN 1505-AC00) CBP Audit Procedures; Use of Sampling Methods and Offsetting of... Protection (CBP) regulations by adding provisions for the use of sampling methods in CBP audits and prior...

  7. Randomized controlled trials 5: Determining the sample size and power for clinical trials and cohort studies.

    Science.gov (United States)

    Greene, Tom

    2015-01-01

    Performing well-powered randomized controlled trials is of fundamental importance in clinical research. The goal of sample size calculations is to assure that statistical power is acceptable while maintaining a small probability of a type I error. This chapter overviews the fundamentals of sample size calculation for standard types of outcomes for two-group studies. It considers (1) the problems of determining the size of the treatment effect that the studies will be designed to detect, (2) the modifications to sample size calculations to account for loss to follow-up and nonadherence, (3) the options when initial calculations indicate that the feasible sample size is insufficient to provide adequate power, and (4) the implication of using multiple primary endpoints. Sample size estimates for longitudinal cohort studies must take account of confounding by baseline factors.

  8. Characterization of Electron Microscopes with Binary Pseudo-random Multilayer Test Samples

    Energy Technology Data Exchange (ETDEWEB)

    V Yashchuk; R Conley; E Anderson; S Barber; N Bouet; W McKinney; P Takacs; D Voronov

    2011-12-31

    Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested [1] and [2] and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi2/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

  9. Characterization of electron microscopes with binary pseudo-random multilayer test samples

    Energy Technology Data Exchange (ETDEWEB)

    Yashchuk, Valeriy V., E-mail: VVYashchuk@lbl.gov [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Conley, Raymond [NSLS-II, Brookhaven National Laboratory, Upton, NY 11973 (United States); Anderson, Erik H. [Center for X-ray Optics, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Barber, Samuel K. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Bouet, Nathalie [NSLS-II, Brookhaven National Laboratory, Upton, NY 11973 (United States); McKinney, Wayne R. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States); Takacs, Peter Z. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Voronov, Dmitriy L. [Advanced Light Source, Lawrence Berkeley National Laboratory, Berkeley, CA 94720 (United States)

    2011-09-01

    Verification of the reliability of metrology data from high quality X-ray optics requires that adequate methods for test and calibration of the instruments be developed. For such verification for optical surface profilometers in the spatial frequency domain, a modulation transfer function (MTF) calibration method based on binary pseudo-random (BPR) gratings and arrays has been suggested and proven to be an effective calibration method for a number of interferometric microscopes, a phase shifting Fizeau interferometer, and a scatterometer [5]. Here we describe the details of development of binary pseudo-random multilayer (BPRML) test samples suitable for characterization of scanning (SEM) and transmission (TEM) electron microscopes. We discuss the results of TEM measurements with the BPRML test samples fabricated from a WiSi{sub 2}/Si multilayer coating with pseudo-randomly distributed layers. In particular, we demonstrate that significant information about the metrological reliability of the TEM measurements can be extracted even when the fundamental frequency of the BPRML sample is smaller than the Nyquist frequency of the measurements. The measurements demonstrate a number of problems related to the interpretation of the SEM and TEM data. Note that similar BPRML test samples can be used to characterize X-ray microscopes. Corresponding work with X-ray microscopes is in progress.

  10. Mannitol and renal dysfunction after endovascular aortic aneurysm repair procedures: a randomized trial.

    Science.gov (United States)

    Kalimeris, Konstantinos; Nikolakopoulos, Nikolaos; Riga, Maria; Christodoulaki, Kalliopi; Moulakakis, Konstantinos G; Dima, Cleanthi; Papasideris, Christos; Sidiropoulou, Tatiana; Kostopanagiotou, Georgia; Pandazi, Angeliki

    2014-08-01

    Endovascular aortic aneurysm repair (EVAR) may result in deterioration of renal function. Mannitol has renovascular and antioxidant properties that could prove beneficial in this respect. A randomized prospective study. Attikon University Hospital, single institution. Eighty-six patients undergoing elective EVAR under regional anesthesia. Patients received hydration alone (controls) or hydration plus mannitol (0.5 g/kg). Creatinine, serum cystatin-C, urine neutrophil-gelatinase-associated lipocalin (NGAL), albuminuria and serum urea were measured 24 hours and 72 hours after the procedure (baseline NGAL was measured in 19 randomly selected patients). Serum creatinine also was measured at the followup of the patients. Serum creatinine and cystatin-C were lower in the mannitol group at 24 hours postoperatively (creatinine, mannitol [n=43]; 1.07±0.26 [CI95%: 0.99-1.15] v controls [n=43]; 1.20±0.30 [CI95%: 1.11-1.30]), but not at 72 hours (creatinine, mannitol [n=43]; 1.13±0.29 [CI95%: 1.04-1.22] v controls [n=43]; 1.26±0.41 [CI95% 1.15-1.38]). Urine NGAL increased substantially at 24 hours without differences between groups. At followup (controls: 13±7 months; mannitol: 12±7 months), there were no differences between creatinine or creatinine clearance (creatinine: controls [n=28]; 1.15±0.39 [CI95% 1.02-1.29] v mannitol [n=23]; 1.05±0.27 [CI95%: 0.95-1.17]). The overall changes of creatinine and creatinine clearance with time were significant in controls but not in the mannitol group. The classification according to the RIFLE criteria yielded 4 patients at risk for renal injury and 2 with renal injury in the control group and 6 patients at risk with no patients with injury in the mannitol group, but the difference of renal dysfunction between the 2 groups was not statistically significant. Mannitol plus hydration during EVAR provides a small but significant benefit for renal function. Future preventive protocols aiming at greater restoration of renal function

  11. A Randomized Trial of Displaying Paid Price Information on Imaging Study and Procedure Ordering Rates.

    Science.gov (United States)

    Chien, Alyna T; Lehmann, Lisa Soleymani; Hatfield, Laura A; Koplan, Kate E; Petty, Carter R; Sinaiko, Anna D; Rosenthal, Meredith B; Sequist, Thomas D

    2017-04-01

    Prior studies have demonstrated how price transparency lowers the test-ordering rates of trainees in hospitals, and physician-targeted price transparency efforts have been viewed as a promising cost-controlling strategy. To examine the effect of displaying paid-price information on test-ordering rates for common imaging studies and procedures within an accountable care organization (ACO). Block randomized controlled trial for 1 year. A total of 1205 fully licensed clinicians (728 primary care, 477 specialists). Starting January 2014, clinicians in the Control arm received no price display; those in the intervention arms received Single or Paired Internal/External Median Prices in the test-ordering screen of their electronic health record. Internal prices were the amounts paid by insurers for the ACO's services; external paid prices were the amounts paid by insurers for the same services when delivered by unaffiliated providers. Ordering rates (orders per 100 face-to-face encounters with adult patients): overall, designated to be completed internally within the ACO, considered "inappropriate" (e.g., MRI for simple headache), and thought to be "appropriate" (e.g., screening colonoscopy). We found no significant difference in overall ordering rates across the Control, Single Median Price, or Paired Internal/External Median Prices study arms. For every 100 encounters, clinicians in the Control arm ordered 15.0 (SD 31.1) tests, those in the Single Median Price arm ordered 15.0 (SD 16.2) tests, and those in the Paired Prices arms ordered 15.7 (SD 20.5) tests (one-way ANOVA p-value 0.88). There was no difference in ordering rates for tests designated to be completed internally or considered to be inappropriate or appropriate. Displaying paid-price information did not alter how frequently primary care and specialist clinicians ordered imaging studies and procedures within an ACO. Those with a particular interest in removing waste from the health care system may want to

  12. TOPICAL MITOMYCIN C IN DACRIOCYSTORHINOSTOMY: ITS EFFECT ON FAILURE RATE OF PROCEDURE - A RANDOMIZED CLINICAL TRIAL

    Directory of Open Access Journals (Sweden)

    A ZANDI

    2002-03-01

    Full Text Available Introduction. Epiphoria is one of the most common symptom among patients in ophtalmologic clinics. The most important cause of it, is tear drainage obstrution through the nasolacrimal duct. Dacryocystorhinostomy (DCR is the only critical treatment. The failure is important complication of DCR and in spite of varios methods, failure rate has remained 10 percent. Ingrowgh of fibrous tissue in osteotomy site and flaps has been known as cause of surgical failue. In this study we investigated the efficacy of mitomycin C as antiproliferative agent on DCR failure rate. Methods. In this clinical trial study, 110 patients with primary acquired nasolacrimal duct obstruction have been chosen between who that refer to the Farabi clinic, and were assigned randomly to either mitomycin or control group. Both group were operated with standard method and one surgen. In control group a cotton aid band and in interventional group a cottonoid band soaked with 0.2 mg/cc mitomycin C was applied to the osteotomy site. After 30 minutes was removed transnasaly. Groups have been examined at 1, 3 and 6 months intervals after surgery. Results. All patients in mitomycin group remained symptom free in all examination, and there was five pateints in control group who had recurrent epiphora. In the control group, 3 patients in 1 st month, 1 patient in 3rd months and 1 patient in 6th month were failed. In 3 patients of mitomycin group, severe post operative bleeding was seen. Discussion. The difference between these groups is (P < 0.01. Intraoperative mitomycin C may possibly improve success rates of DCR procedure with no serious complication.

  13. On analysis-based two-step interpolation methods for randomly sampled seismic data

    Science.gov (United States)

    Yang, Pengliang; Gao, Jinghuai; Chen, Wenchao

    2013-02-01

    Interpolating the missing traces of regularly or irregularly sampled seismic record is an exceedingly important issue in the geophysical community. Many modern acquisition and reconstruction methods are designed to exploit the transform domain sparsity of the few randomly recorded but informative seismic data using thresholding techniques. In this paper, to regularize randomly sampled seismic data, we introduce two accelerated, analysis-based two-step interpolation algorithms, the analysis-based FISTA (fast iterative shrinkage-thresholding algorithm) and the FPOCS (fast projection onto convex sets) algorithm from the IST (iterative shrinkage-thresholding) algorithm and the POCS (projection onto convex sets) algorithm. A MATLAB package is developed for the implementation of these thresholding-related interpolation methods. Based on this package, we compare the reconstruction performance of these algorithms, using synthetic and real seismic data. Combined with several thresholding strategies, the accelerated convergence of the proposed methods is also highlighted.

  14. Hemodynamic and glucometabolic factors fail to predict renal function in a random population sample

    DEFF Research Database (Denmark)

    Pareek, M.; Nielsen, M.; Olesen, Thomas Bastholm

    2015-01-01

    Objective: To determine whether baseline hemodynamic and/or glucometabolic risk factors could predict renal function at follow-up, independently of baseline serum creatinine, in survivors from a random population sample. Design and method: We examined associations between baseline serum creatinine...... indices of beta-cell function (HOMA-2B), insulin sensitivity (HOMA-2S), and insulin resistance (HOMA-2IR)), traditional cardiovascular risk factors (age, sex, smoking status, body mass index, diabetes mellitus, total serum cholesterol), and later renal function determined as serum cystatin C in 238 men...... and 7 women aged 38 to 49 years at the time of inclusion, using multivariable linear regression analysis (p-entry 0.05, p-removal 0.20). Study subjects came from a random population based sample and were included 1974-1992, whilst the follow-up with cystatin C measurement was performed 2002...

  15. An inversion method based on random sampling for real-time MEG neuroimaging

    CERN Document Server

    Pascarella, Annalisa

    2016-01-01

    The MagnetoEncephaloGraphy (MEG) has gained great interest in neurorehabilitation training due to its high temporal resolution. The challenge is to localize the active regions of the brain in a fast and accurate way. In this paper we use an inversion method based on random spatial sampling to solve the real-time MEG inverse problem. Several numerical tests on synthetic but realistic data show that the method takes just a few hundredths of a second on a laptop to produce an accurate map of the electric activity inside the brain. Moreover, it requires very little memory storage. For this reasons the random sampling method is particularly attractive in real-time MEG applications.

  16. Radiochemical procedures for analysis of Pu, Am, Cs and Sr in water, soil, sediments and biota samples

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.M.; Jokela, T.A.; Noshkin, V.E.

    1994-02-01

    The Environmental Radioactivity Analysis Laboratory (ERAL) was established as an analytical facility. The primary function of ERAL is to provide fast and accurate radiological data of environmental samples. Over the years, many radiochemical procedures have been developed by the staffs of ERAL. As result, we have found that our procedures exist in many different formats and in many different notebooks, documents and files. Therefore, in order to provide for more complete and orderly documentation of the radiochemical procedures that are being used by ERAL, we have decided to standardize the format and compile them into a series of reports. This first report covers procedures we have developed and are using for the radiochemical analysis of Pu, Am, Cs, and Sr in various matrices. Additional analytical procedures and/or revisions for other elements will be reported as they become available through continuation of these compilation efforts.

  17. Modified Exponential Type Estimator for Population Mean Using Auxiliary Variables in Stratified Random Sampling

    OpenAIRE

    Özel, Gamze

    2015-01-01

    In this paper, a new exponential type estimator is developed in the stratified random sampling for the population mean using auxiliary variable information. In order to evaluate efficiency of the introduced estimator, we first review some estimators and study the optimum property of the suggested strategy. To judge the merits of the suggested class of estimators over others under the optimal condition, simulation study and real data applications are conducted. The results show that the introduc...

  18. Effectiveness of hand hygiene education among a random sample of women from the community

    OpenAIRE

    Ubheeram, J.; Biranjia-Hurdoyal, S.D.

    2017-01-01

    Summary Objective. The effectiveness of hand hygiene education was investigated by studying the hand hygiene awareness and bacterial hand contamination among a random sample of 170 women in the community. Methods. Questionnaire was used to assess the hand hygiene awareness score, followed by swabbing of the dominant hand. Bacterial identification was done by conventional biochemical tests. Results. Better hand hygiene awareness score was significantly associated with age, scarce bacterial gro...

  19. Control Capacity and A Random Sampling Method in Exploring Controllability of Complex Networks

    OpenAIRE

    Jia, Tao; Barab?si, Albert-L?szl?

    2013-01-01

    Controlling complex systems is a fundamental challenge of network science. Recent advances indicate that control over the system can be achieved through a minimum driver node set (MDS). The existence of multiple MDS's suggests that nodes do not participate in control equally, prompting us to quantify their participations. Here we introduce control capacity quantifying the likelihood that a node is a driver node. To efficiently measure this quantity, we develop a random sampling algorithm. Thi...

  20. Classification of epileptic EEG signals based on simple random sampling and sequential feature selection

    OpenAIRE

    Ghayab, Hadi Ratham Al; Li, Yan; Abdulla, Shahab; Diykh, Mohammed; Wan, Xiangkui

    2016-01-01

    Electroencephalogram (EEG) signals are used broadly in the medical fields. The main applications of EEG signals are the diagnosis and treatment of diseases such as epilepsy, Alzheimer, sleep problems and so on. This paper presents a new method which extracts and selects features from multi-channel EEG signals. This research focuses on three main points. Firstly, simple random sampling (SRS) technique is used to extract features from the time domain of EEG signals. Secondly, the sequential fea...

  1. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.

    2008-01-01

    , and 30 days at the same temperatures. 27 inflammatory markers in serum and plasma and 25 markers in DBSS were measured by a previously validated multiplex sandwich immunoassay using Luminex xMAP technology. The measurable concentrations of several cytokines in serum and plasma were significantly......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected...... increased when blood samples were stored for a period of time before the centrifugation, for certain cytokines more than 1000 fold compared to serum and plasma isolated and frozen immediately after venepuncture. The concentrations in serum generally increased more than in plasma. The measurable...

  2. Precision of systematic and random sampling in clustered populations: habitat patches and aggregating organisms.

    Science.gov (United States)

    McGarvey, Richard; Burch, Paul; Matthews, Janet M

    2016-01-01

    Natural populations of plants and animals spatially cluster because (1) suitable habitat is patchy, and (2) within suitable habitat, individuals aggregate further into clusters of higher density. We compare the precision of random and systematic field sampling survey designs under these two processes of species clustering. Second, we evaluate the performance of 13 estimators for the variance of the sample mean from a systematic survey. Replicated simulated surveys, as counts from 100 transects, allocated either randomly or systematically within the study region, were used to estimate population density in six spatial point populations including habitat patches and Matérn circular clustered aggregations of organisms, together and in combination. The standard one-start aligned systematic survey design, a uniform 10 x 10 grid of transects, was much more precise. Variances of the 10 000 replicated systematic survey mean densities were one-third to one-fifth of those from randomly allocated transects, implying transect sample sizes giving equivalent precision by random survey would need to be three to five times larger. Organisms being restricted to patches of habitat was alone sufficient to yield this precision advantage for the systematic design. But this improved precision for systematic sampling in clustered populations is underestimated by standard variance estimators used to compute confidence intervals. True variance for the survey sample mean was computed from the variance of 10 000 simulated survey mean estimates. Testing 10 published and three newly proposed variance estimators, the two variance estimators (v) that corrected for inter-transect correlation (ν₈ and ν(W)) were the most accurate and also the most precise in clustered populations. These greatly outperformed the two "post-stratification" variance estimators (ν₂ and ν₃) that are now more commonly applied in systematic surveys. Similar variance estimator performance rankings were found with

  3. Soft tissue cell adhesion to titanium abutments after different cleaning procedures: preliminary results of a randomized clinical trial.

    Science.gov (United States)

    Canullo, L; Penarrocha-Oltra, D; Marchionni, S; Bagán, L; Peñarrocha-Diago, M-A; Micarelli, C

    2014-03-01

    A randomized controlled trial was performed to assess soft tissue cell adhesion to implant titanium abutments subjected to different cleaning procedures and test if plasma cleaning can enhance cell adhesion at an early healing time. Eighteen patients with osseointegrated and submerged implants were included. Before re-opening, 18 abutments were divided in 3 groups corresponding to different clinical conditions with different cleaning processes: no treatment (G1), laboratory customization and cleaning by steam (G2), cleaning by plasma of Argon (G3). Abutments were removed after 1 week and scanning electron microscopy was used to analyze cell adhesion to the abutment surface quantitatively (percentage of area occupied by cells) and qualitatively (aspect of adhered cells and presence of contaminants). Mean percentages of area occupied by cells were 17.6 ± 22.7%, 16.5 ± 12.9% and 46.3 ± 27.9% for G1, G2 and G3 respectively. Differences were statistically significant between G1 and G3 (p=0.030), close to significance between G2 and G3 (p=0.056), and non-significant between G1 and G2 (p=0.530). The proportion of samples presenting adhered cells was homogeneous among the 3 groups (p-valor = 1.000). In all cases cells presented a flattened aspect; in 2 cases cells were less efficiently adhered and in 1 case cells presented filipodia. Three cases showed contamination with cocobacteria. Within the limits of the present study, plasma of Argon may enhance cell adhesion to titanium abutments, even at the early stage of soft tissue healing. Further studies with greater samples are necessary to confirm these findings.

  4. Determining optimal sample sizes for multi-stage randomized clinical trials using value of information methods.

    Science.gov (United States)

    Willan, Andrew; Kowgier, Matthew

    2008-01-01

    Traditional sample size calculations for randomized clinical trials depend on somewhat arbitrarily chosen factors, such as Type I and II errors. An effectiveness trial (otherwise known as a pragmatic trial or management trial) is essentially an effort to inform decision-making, i.e., should treatment be adopted over standard? Taking a societal perspective and using Bayesian decision theory, Willan and Pinto (Stat. Med. 2005; 24:1791-1806 and Stat. Med. 2006; 25:720) show how to determine the sample size that maximizes the expected net gain, i.e., the difference between the cost of doing the trial and the value of the information gained from the results. These methods are extended to include multi-stage adaptive designs, with a solution given for a two-stage design. The methods are applied to two examples. As demonstrated by the two examples, substantial increases in the expected net gain (ENG) can be realized by using multi-stage adaptive designs based on expected value of information methods. In addition, the expected sample size and total cost may be reduced. Exact solutions have been provided for the two-stage design. Solutions for higher-order designs may prove to be prohibitively complex and approximate solutions may be required. The use of multi-stage adaptive designs for randomized clinical trials based on expected value of sample information methods leads to substantial gains in the ENG and reductions in the expected sample size and total cost.

  5. Sample size calculations for pilot randomized trials: a confidence interval approach.

    Science.gov (United States)

    Cocks, Kim; Torgerson, David J

    2013-02-01

    To describe a method using confidence intervals (CIs) to estimate the sample size for a pilot randomized trial. Using one-sided CIs and the estimated effect size that would be sought in a large trial, we calculated the sample size needed for pilot trials. Using an 80% one-sided CI, we estimated that a pilot trial should have at least 9% of the sample size of the main planned trial. Using the estimated effect size difference for the main trial and using a one-sided CI, this allows us to calculate a sample size for a pilot trial, which will make its results more useful than at present. Copyright © 2013 Elsevier Inc. All rights reserved.

  6. Music Reduces State Anxiety Scores in Patients Undergoing Pleural Procedures: A Randomized Controlled Trial.

    Science.gov (United States)

    Mackintosh, John; Cone, Grace; Harland, Kate; Sriram, Krishna B

    2018-01-18

    Patient anxiety is an often overlooked complication of pleural diagnostic and therapeutic procedures. Listening to music is effective in reducing patient anxiety in some endoscopy procedures but has not yet been evaluated in pleural procedures. Consecutive patients undergoing therapeutic pleural procedures were randomised to music and control groups. Participants in the music group listened to self selected music using ear-bud headphones for the duration of the procedure. State anxiety was assessed before and after the procedure using the State Trait Anxiety Inventory (STAI). Physiological parameters were also measured. 60 patients were included in the study. In the music group, a reduction in State Anxiety Scores were observed post-procedure (34±11 vs. 48±13, p<0.001) while no change was observed in the Control group (40±11 vs. 42±11, p=0.51). Participants in the music group had reductions in heart rate (87±17 vs. 95±15, p=0.04), systolic (121±13 vs. 130±16, p=0.02) and diastolic blood pressure (72±8 vs. 78±9, p=0.01) post procedure compared to the pre-procedures values. A similar change was not detected in the control group: heart rate (86±17 vs. 85±15, p=0.73), systolic (133±21 vs. 134±20, p=0.83) and diastolic blood pressure (77±9 vs. 79±10, p=0.30). There was no difference in patient pain scores (p=0.8), willingness to undergo the procedure again (p=0.27), satisfaction with the performance of the pleural procedure (p=0.20) and duration of the procedure (p=0.68) between the music and control groups. Listening to music appears to be beneficial in reducing anxiety in patients undergoing pleural procedures. This article is protected by copyright. All rights reserved.

  7. The effect of music in gynaecological office procedures on pain, anxiety and satisfaction: a randomized controlled trial.

    Science.gov (United States)

    Mak, N; Reinders, I M A; Slockers, S A; Westen, E H M N; Maas, J W M; Bongers, M Y

    2017-01-01

    Pain can interfere with office procedures in gynaecology. The aim of this study is to measure the positive effect of music in gynaecological office procedures. A randomized controlled trial was performed between October 2014 and January 2016. Women scheduled for an office hysteroscopy or colposcopy were eligible for randomization in the music group or control group. Stratification for hysteroscopy and colposcopy took place. The primary outcome is patients' level of pain during the procedure measured by the visual analogue scale (VAS). Secondary outcomes include patients' level of pain after the procedure, anxiety and satisfaction of patient and doctor. No positive effect of music on patients' perception of pain during the procedure was measured, neither for the hysteroscopy group (57 mm vs. 52 mm) nor for the colposcopy group (32 mm vs. 32 mm). Secondary outcomes were also similar for both groups. This study showed no positive effect of music on patients' level of pain, anxiety or satisfaction of patient or doctor for office hysteroscopy and colposcopy. We believe a multimodal approach has to be used to decrease patient distress in terms of pain and anxiety, with or without music. Dutch Trial Register, NTR4924.

  8. RISK-ASSESSMENT PROCEDURES AND ESTABLISHING THE SIZE OF SAMPLES FOR AUDITING FINANCIAL STATEMENTS

    National Research Council Canada - National Science Library

    Daniel Botez

    2014-01-01

    In auditing financial statements, the procedures for the assessment of the risks and the calculation of the materiality differ from an auditor to another, by audit cabinet policy or advice professional bodies...

  9. Estimating the Size of a Large Network and its Communities from a Random Sample.

    Science.gov (United States)

    Chen, Lin; Karbasi, Amin; Crawford, Forrest W

    2016-01-01

    Most real-world networks are too large to be measured or studied directly and there is substantial interest in estimating global network properties from smaller sub-samples. One of the most important global properties is the number of vertices/nodes in the network. Estimating the number of vertices in a large network is a major challenge in computer science, epidemiology, demography, and intelligence analysis. In this paper we consider a population random graph G = (V, E) from the stochastic block model (SBM) with K communities/blocks. A sample is obtained by randomly choosing a subset W ⊆ V and letting G(W) be the induced subgraph in G of the vertices in W. In addition to G(W), we observe the total degree of each sampled vertex and its block membership. Given this partial information, we propose an efficient PopULation Size Estimation algorithm, called PULSE, that accurately estimates the size of the whole population as well as the size of each community. To support our theoretical analysis, we perform an exhaustive set of experiments to study the effects of sample size, K, and SBM model parameters on the accuracy of the estimates. The experimental results also demonstrate that PULSE significantly outperforms a widely-used method called the network scale-up estimator in a wide variety of scenarios.

  10. Optimization of Procedures for Isolation of Mycobacteria from Soil and Water Samples Obtained in Northern India

    OpenAIRE

    Parashar, Deepti; D S Chauhan; Sharma, V.D; Chauhan, Aradhana; Chauhan, S.V.S.; Katoch, V.M.

    2004-01-01

    For isolation of environmental mycobacteria, a decontamination procedure has been standardized by which treatment with 3% sodium dodecyl sulfate plus 4% NaOH (15 and 30 min for rapid and slow growers, respectively) is followed by incubation with 2% cetrimide (5 and 15 min for fast- and slow-growing mycobacteria, respectively); this procedure was found to completely eliminate contamination with other organisms and resulted in the isolation of only mycobacteria.

  11. Rectal Thiopental versus Intramuscular Ketamine in Pediatric Procedural Sedation and Analgesia; a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Reza Azizkhani

    2015-01-01

    Full Text Available Introduction: Physicians frequently deal with procedures which require sedation of pediatric patients. Laceration repair is one of them. No study has been performed regarding the comparison between induction of sedation with sodium thiopental and ketamine in laceration repair. Therefore, the present study was aimed to comparison of induced sedation by rectal sodium thiopental and muscular injection of hydrochloride ketamine in pediatric patients need laceration repair. Methods: The presented study is a single-blinded clinical trial performed through 2013 to 2014 in Ayatollah Kashani and Alzahra Hospitals, Isfahan, Iran. Patients from 3 months to 14 years, needed sedation for laceration repair, were entered. Patients were sequentially evaluated and randomly categorized in two groups of hydrochloride ketamine with dose of 2-4 milligram per kilogram and sodium thiopental with dose of 25 milligram per kilogram. Demographic data and vital signs before drug administration and after induction of sedation, Ramsey score, time to onset of action, and sedation recovery time were evaluated. Chi-squared, Mann-Whitney, and Non-parametric analysis of covariance tests were used. P<0.05 was considered as a significant level. Results: In this study 60 pediatric patients were entered. 30 patients with mean age of 42.8±18.82 months were received sodium thiopental and the rest with mean age of 30.08±16.88 months given ketamine. Mann-Whitney test was showed that time to onset of action in sodium thiopental group (28.23±5.18 minutes was significantly higher than ketamine (7.77±4.13 minutes, (p<0.001. The sedation recovery time in ketamine group (29.83±7.70 was higher than sodium thiopental. Depth of sedation had no significant difference between two groups based on Ramsey score (p=0.87. No significant difference was seen between two groups in the respiratory rate (df=1, 58; F=0.002; P=0.96 and heart rate (df=1, 58; F=0.98; P=0.33. However, arterial oxygen

  12. Nicotine therapy sampling to induce quit attempts among smokers unmotivated to quit: a randomized clinical trial.

    Science.gov (United States)

    Carpenter, Matthew J; Hughes, John R; Gray, Kevin M; Wahlquist, Amy E; Saladin, Michael E; Alberg, Anthony J

    2011-11-28

    Rates of smoking cessation have not changed in a decade, accentuating the need for novel approaches to prompt quit attempts. Within a nationwide randomized clinical trial (N = 849) to induce further quit attempts and cessation, smokers currently unmotivated to quit were randomized to a practice quit attempt (PQA) alone or to nicotine replacement therapy (hereafter referred to as nicotine therapy), sampling within the context of a PQA. Following a 6-week intervention period, participants were followed up for 6 months to assess outcomes. The PQA intervention was designed to increase motivation, confidence, and coping skills. The combination of a PQA plus nicotine therapy sampling added samples of nicotine lozenges to enhance attitudes toward pharmacotherapy and to promote the use of additional cessation resources. Primary outcomes included the incidence of any ever occurring self-defined quit attempt and 24-hour quit attempt. Secondary measures included 7-day point prevalence abstinence at any time during the study (ie, floating abstinence) and at the final follow-up assessment. Compared with PQA intervention, nicotine therapy sampling was associated with a significantly higher incidence of any quit attempt (49% vs 40%; relative risk [RR], 1.2; 95% CI, 1.1-1.4) and any 24-hour quit attempt (43% vs 34%; 1.3; 1.1-1.5). Nicotine therapy sampling was marginally more likely to promote floating abstinence (19% vs 15%; RR, 1.3; 95% CI, 1.0-1.7); 6-month point prevalence abstinence rates were no different between groups (16% vs 14%; 1.2; 0.9-1.6). Nicotine therapy sampling during a PQA represents a novel strategy to motivate smokers to make a quit attempt. clinicaltrials.gov Identifier: NCT00706979.

  13. Location and multi-depot vehicle routing for emergency vehicles using tour coverage and random sampling

    Directory of Open Access Journals (Sweden)

    Alireza Goli

    2015-09-01

    Full Text Available Distribution and optimum allocation of emergency resources are the most important tasks, which need to be accomplished during crisis. When a natural disaster such as earthquake, flood, etc. takes place, it is necessary to deliver rescue efforts as quickly as possible. Therefore, it is important to find optimum location and distribution of emergency relief resources. When a natural disaster occurs, it is not possible to reach some damaged areas. In this paper, location and multi-depot vehicle routing for emergency vehicles using tour coverage and random sampling is investigated. In this study, there is no need to visit all the places and some demand points receive their needs from the nearest possible location. The proposed study is implemented for some randomly generated numbers in different sizes. The preliminary results indicate that the proposed method was capable of reaching desirable solutions in reasonable amount of time.

  14. ESTIMATION OF FINITE POPULATION MEAN USING RANDOM NON–RESPONSE IN SURVEY SAMPLING

    Directory of Open Access Journals (Sweden)

    Housila P. Singh

    2010-12-01

    Full Text Available This paper consider the problem of estimating the population mean under three different situations of random non–response envisaged by Singh et al (2000. Some ratio and product type estimators have been proposed and their properties are studied under an assumption that the number of sampling units on which information can not be obtained owing to random non–response follows some distribution. The suggested estimators are compared with the usual ratio and product estimators. An empirical study is carried out to show the performance of the suggested estimators over usual unbiased estimator, ratio and product estimators. A generalized version of the proposed ratio and product estimators is also given.

  15. Chi-Squared Test of Fit and Sample Size-A Comparison between a Random Sample Approach and a Chi-Square Value Adjustment Method.

    Science.gov (United States)

    Bergh, Daniel

    2015-01-01

    Chi-square statistics are commonly used for tests of fit of measurement models. Chi-square is also sensitive to sample size, which is why several approaches to handle large samples in test of fit analysis have been developed. One strategy to handle the sample size problem may be to adjust the sample size in the analysis of fit. An alternative is to adopt a random sample approach. The purpose of this study was to analyze and to compare these two strategies using simulated data. Given an original sample size of 21,000, for reductions of sample sizes down to the order of 5,000 the adjusted sample size function works as good as the random sample approach. In contrast, when applying adjustments to sample sizes of lower order the adjustment function is less effective at approximating the chi-square value for an actual random sample of the relevant size. Hence, the fit is exaggerated and misfit under-estimated using the adjusted sample size function. Although there are big differences in chi-square values between the two approaches at lower sample sizes, the inferences based on the p-values may be the same.

  16. Randomized controlled trial on timing and number of sampling for bile aspiration cytology.

    Science.gov (United States)

    Tsuchiya, Tomonori; Yokoyama, Yukihiro; Ebata, Tomoki; Igami, Tsuyoshi; Sugawara, Gen; Kato, Katsuyuki; Shimoyama, Yoshie; Nagino, Masato

    2014-06-01

    The issue on timing and number of bile sampling for exfoliative bile cytology is still unsettled. A total of 100 patients with cholangiocarcinoma undergoing resection after external biliary drainage were randomized into two groups: a 2-day group where bile was sampled five times per day for 2 days; and a 10-day group where bile was sampled once per day for 10 days (registered University Hospital Medical Information Network/ID 000005983). The outcome of 87 patients who underwent laparotomy was analyzed, 44 in the 2-day group and 43 in the 10-day group. There were no significant differences in patient characteristics between the two groups. Positivity after one sampling session was significantly lower in the 2-day group than in the 10-day group (17.0 ± 3.7% vs. 20.7 ± 3.5%, P = 0.034). However, cumulative positivity curves were similar and overlapped each other between both groups. The final cumulative positivity by the 10th sampling session was 52.3% in the 2-day group and 51.2% in the 10-day group. We observed a small increase in cumulative positivity after the 5th or 6th session in both groups. Bile cytology positivity is unlikely to be affected by sample time. © 2013 Japanese Society of Hepato-Biliary-Pancreatic Surgery.

  17. Establishing Reliable Cognitive Change in Children with Epilepsy: The Procedures and Results for a Sample with Epilepsy

    Science.gov (United States)

    van Iterson, Loretta; Augustijn, Paul B.; de Jong, Peter F.; van der Leij, Aryan

    2013-01-01

    The goal of this study was to investigate reliable cognitive change in epilepsy by developing computational procedures to determine reliable change index scores (RCIs) for the Dutch Wechsler Intelligence Scales for Children. First, RCIs were calculated based on stability coefficients from a reference sample. Then, these RCIs were applied to a…

  18. Estimating the Size of a Large Network and its Communities from a Random Sample

    CERN Document Server

    Chen, Lin; Crawford, Forrest W

    2016-01-01

    Most real-world networks are too large to be measured or studied directly and there is substantial interest in estimating global network properties from smaller sub-samples. One of the most important global properties is the number of vertices/nodes in the network. Estimating the number of vertices in a large network is a major challenge in computer science, epidemiology, demography, and intelligence analysis. In this paper we consider a population random graph G = (V;E) from the stochastic block model (SBM) with K communities/blocks. A sample is obtained by randomly choosing a subset W and letting G(W) be the induced subgraph in G of the vertices in W. In addition to G(W), we observe the total degree of each sampled vertex and its block membership. Given this partial information, we propose an efficient PopULation Size Estimation algorithm, called PULSE, that correctly estimates the size of the whole population as well as the size of each community. To support our theoretical analysis, we perform an exhausti...

  19. Studies on spectral analysis of randomly sampled signals: Application to laser velocimetry data

    Science.gov (United States)

    Sree, David

    1992-01-01

    Spectral analysis is very useful in determining the frequency characteristics of many turbulent flows, for example, vortex flows, tail buffeting, and other pulsating flows. It is also used for obtaining turbulence spectra from which the time and length scales associated with the turbulence structure can be estimated. These estimates, in turn, can be helpful for validation of theoretical/numerical flow turbulence models. Laser velocimetry (LV) is being extensively used in the experimental investigation of different types of flows, because of its inherent advantages; nonintrusive probing, high frequency response, no calibration requirements, etc. Typically, the output of an individual realization laser velocimeter is a set of randomly sampled velocity data. Spectral analysis of such data requires special techniques to obtain reliable estimates of correlation and power spectral density functions that describe the flow characteristics. FORTRAN codes for obtaining the autocorrelation and power spectral density estimates using the correlation-based slotting technique were developed. Extensive studies have been conducted on simulated first-order spectrum and sine signals to improve the spectral estimates. A first-order spectrum was chosen because it represents the characteristics of a typical one-dimensional turbulence spectrum. Digital prefiltering techniques, to improve the spectral estimates from randomly sampled data were applied. Studies show that the spectral estimates can be increased up to about five times the mean sampling rate.

  20. Prevalence and correlates of problematic smartphone use in a large random sample of Chinese undergraduates.

    Science.gov (United States)

    Long, Jiang; Liu, Tie-Qiao; Liao, Yan-Hui; Qi, Chang; He, Hao-Yu; Chen, Shu-Bao; Billieux, Joël

    2016-11-17

    Smartphones are becoming a daily necessity for most undergraduates in Mainland China. Because the present scenario of problematic smartphone use (PSU) is largely unexplored, in the current study we aimed to estimate the prevalence of PSU and to screen suitable predictors for PSU among Chinese undergraduates in the framework of the stress-coping theory. A sample of 1062 undergraduate smartphone users was recruited by means of the stratified cluster random sampling strategy between April and May 2015. The Problematic Cellular Phone Use Questionnaire was used to identify PSU. We evaluated five candidate risk factors for PSU by using logistic regression analysis while controlling for demographic characteristics and specific features of smartphone use. The prevalence of PSU among Chinese undergraduates was estimated to be 21.3%. The risk factors for PSU were majoring in the humanities, high monthly income from the family (≥1500 RMB), serious emotional symptoms, high perceived stress, and perfectionism-related factors (high doubts about actions, high parental expectations). PSU among undergraduates appears to be ubiquitous and thus constitutes a public health issue in Mainland China. Although further longitudinal studies are required to test whether PSU is a transient phenomenon or a chronic and progressive condition, our study successfully identified socio-demographic and psychological risk factors for PSU. These results, obtained from a random and thus representative sample of undergraduates, opens up new avenues in terms of prevention and regulation policies.

  1. CTEPP STANDARD OPERATING PROCEDURE FOR HANDLING SAMPLE AND DATA CUSTODY (SOP-2.26)

    Science.gov (United States)

    This SOP describes the method for handling sample custody. A standardized Chain-of-Custody (CoC) Record is used to document the sample/data custody. Each participant is assigned one CoC Record for the samples/data collected at their home and/or day care center.

  2. 9 CFR 147.12 - Procedures for collection, isolation, and identification of Salmonella from environmental samples...

    Science.gov (United States)

    2010-01-01

    ... sanitizing soap prior to the sampling. Outer clothing, including gloves, should be changed between visits to... strength skim milk from USDA-APHIS “Recommended Sample Collection Methods for Environmental Samples.... Autoclave the assembled DS sampler bundle and transfer it with sterile forceps or other aseptic method to a...

  3. 40 CFR 90.413 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ... percent of the final reading for the dilute exhaust sample. The ADC must store a single value representing... dictates that exhaust emission sample bag analyzer readings below 15 percent of full scale should generally... dilute exhaust sampling only) by the grab (“bag”) technique outlined in paragraph (c) of this section. (e...

  4. Effect of repeated Kangaroo Mother Care on repeated procedural pain in preterm infants: A randomized controlled trial.

    Science.gov (United States)

    Gao, Haixia; Xu, Guihua; Gao, Honglian; Dong, Rongzhi; Fu, Hongjie; Wang, Danwen; Zhang, Heng; Zhang, Hua

    2015-07-01

    Preterm infants' repeated exposure to painful procedures may lead to negative consequences. Thus, non-pharmacological pain management is essential due to medication side effects. Kangaroo Mother Care, which aims at offering human care to neonates, has been established for the treatment of a single painful procedure, but the effectiveness of Kangaroo Mother Care across repeated painful procedures is unknown. To test the effectiveness of repeated Kangaroo Mother Care on repeated heel-stick pain in preterm neonates. Randomized controlled trial. Level III Neonatal Intensive Care Unit at a large teaching hospital in northeast China. Preterm infants (gestational age less than 37 weeks) (n=80) were recruited and randomly assigned using a random table format to either an incubator group (n=40) or Kangaroo Mother Care group (n=40). Pain assessments were carried out during four routine heel stick procedures. For the first heel stick, preterm infants in each group received no intervention (routinely stayed in incubator). During the next three heel sticks, the infants in Kangaroo Mother Care group received heel sticks during Kangaroo Mother Care, while infants in the incubator group received heel sticks in incubator. The procedure of each heel stick included 3 phases: baseline, blood collection and recovery. Crying, grimacing and heart rate in response to pain were evaluated at each phase across four heel sticks by three trained independent observers who were blinded to the purpose of the study. Data were analyzed by analysis of variance (ANOVA), with repeated measures at different evaluation phases of heel stick. 75 preterm infants completed the protocol. Between-group comparison revealed that preterm infants' heart rate was significantly lower, and the duration of crying and facial grimacing were both significantly shorter in the Kangaroo Mother Care group (n=38) than the incubator group (n=37) from the blood collection phase to recovery phase during repeated heel sticks. No

  5. CTEPP STANDARD OPERATING PROCEDURE FOR DAY CARE CENTER SAMPLE SUBJECTS RECRUITMENT (SOP-1.11)

    Science.gov (United States)

    The CTEPP subject recruitment procedures for the daycare center component are described in the SOP. There are two stages in this phase of CTEPP subject recruitment. The objective of the first stage is to enroll daycare centers for the study. Six target counties in each state ar...

  6. Visual Sample Plan (VSP) Statistical Software as Related to the CTBTO’s On-Site Inspection Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Pulsipher, Trenton C.; Walsh, Stephen J.; Pulsipher, Brent A.; Milbrath, Brian D.

    2010-09-01

    In the event of a potential nuclear weapons test the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is commissioned to conduct an on-site investigation (OSI) of the suspected test site in an effort to find confirmatory evidence of the nuclear test. The OSI activities include collecting air, surface soil, and underground samples to search for indications of a nuclear weapons test - these indicators include radionuclides and radioactive isotopes Ar and Xe. This report investigates the capability of the Visual Sample Plan (VSP) software to contribute to the sampling activities of the CTBTO during an OSI. VSP is a statistical sampling design software, constructed under data quality objectives, which has been adapted for environmental remediation and contamination detection problems for the EPA, US Army, DoD and DHS among others. This report provides discussion of a number of VSP sample designs, which may be pertinent to the work undertaken during an OSI. Examples and descriptions of such designs include hot spot sampling, combined random and judgment sampling, multiple increment sampling, radiological transect surveying, and a brief description of other potentially applicable sampling methods. Further, this work highlights a potential need for the use of statistically based sample designs in OSI activities. The use of such designs may enable canvassing a sample area without full sampling, provide a measure of confidence that radionuclides are not present, and allow investigators to refocus resources in other areas of concern.

  7. Efficacy of a children’s procedural preparation and distraction device on healing in acute burn wound care procedures: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Brown Nadia J

    2012-12-01

    Full Text Available Abstract Background The intense pain and anxiety triggered by burns and their associated wound care procedures are well established in the literature. Non-pharmacological intervention is a critical component of total pain management protocols and is used as an adjunct to pharmacological analgesia. An example is virtual reality, which has been used effectively to dampen pain intensity and unpleasantness. Possible links or causal relationships between pain/anxiety/stress and burn wound healing have previously not been investigated. The purpose of this study is to investigate these relationships, specifically by determining if a newly developed multi-modal procedural preparation and distraction device (Ditto™ used during acute burn wound care procedures will reduce the pain and anxiety of a child and increase the rate of re-epithelialization. Methods/design Children (4 to 12 years with acute burn injuries presenting for their first dressing change will be randomly assigned to either the (1 Control group (standard distraction or (2 Ditto™ intervention group (receiving Ditto™, procedural preparation and Ditto™ distraction. It is intended that a minimum of 29 participants will be recruited for each treatment group. Repeated measures of pain intensity, anxiety, stress and healing will be taken at every dressing change until complete wound re-epithelialization. Further data collection will aid in determining patient satisfaction and cost effectiveness of the Ditto™ intervention, as well as its effect on speed of wound re-epithelialization. Discussion Results of this study will provide data on whether the disease process can be altered by reducing stress, pain and anxiety in the context of acute burn wounds. Trial registration ACTRN12611000913976

  8. RESTORING LOCOMOTION IN SPINAL CORD INJURY: A RANDOMIZED CONTROLLED TRIAL OF THE LION PROCEDURE

    DEFF Research Database (Denmark)

    Elmgreen, Søren Bruno; Forman, Axel; Possover, Marc

    2017-01-01

    that four patients with chronic traumatic spinal cord 153 injury (SCI) regained significant sensory and motor function following this laparoscopic implantation of neuroprosthesis (LION). Our aim is, therefore, to conduct a prospective randomized activecontrolled trial with elaborate neurophysiological...

  9. Sample size determination for assessing equivalence based on proportion ratio under a randomized trial with non-compliance and missing outcomes.

    Science.gov (United States)

    Lui, Kung-Jong; Chang, Kuang-Chao

    2008-01-15

    When a generic drug is developed, it is important to assess the equivalence of therapeutic efficacy between the new and the standard drugs. Although the number of publications on testing equivalence and its relevant sample size determination is numerous, the discussion on sample size determination for a desired power of detecting equivalence under a randomized clinical trial (RCT) with non-compliance and missing outcomes is limited. In this paper, we derive under the compound exclusion restriction model the maximum likelihood estimator (MLE) for the ratio of probabilities of response among compliers between two treatments in a RCT with both non-compliance and missing outcomes. Using the MLE with the logarithmic transformation, we develop an asymptotic test procedure for assessing equivalence and find that this test procedure can perform well with respect to type I error based on Monte Carlo simulation. We further develop a sample size calculation formula for a desired power of detecting equivalence at a nominal alpha-level. To evaluate the accuracy of the sample size calculation formula, we apply Monte Carlo simulation again to calculate the simulated power of the proposed test procedure corresponding to the resulting sample size for a desired power of 80 per cent at 0.05 level in a variety of situations. We also include a discussion on determining the optimal ratio of sample size allocation subject to a desired power to minimize a linear cost function and provide a sensitivity analysis of the sample size formula developed here under an alterative model with missing at random. Copyright (c) 2007 John Wiley & Sons, Ltd.

  10. Protein/creatinine ratio on random urine samples for prediction of proteinuria in preeclampsia.

    Science.gov (United States)

    Roudsari, F Vahid; Ayati, S; Ayatollahi, H; Shakeri, M T

    2012-01-01

    To evaluate Protein/Creatinine ratio on random urine samples for prediction of proteinuria in preeclampsia. This study was performed on 150 pregnant women who were hospitalized as preeclampsia in Ghaem Hospital during 2006. At first, a 24-hours urine sample was collected for each patient to determine protein/creatinine ratio. Then, 24-hours urine collection was analyzed for the evaluation of proteinuria. Statistical analysis was performed with SPSS software. A total of 150 patients entered the study. There was a significant relation between the 24-hours urine protein and protein/creatinine ratio (r = 0.659, P < 0.001). Since the measurement of protein/creatinine ratio is more accurate, reliable, and cost-effective, it can be replaced by the method of measurement the 24-hours urine protein.

  11. Pre-exposure to food temptation reduces subsequent consumption: A test of the procedure with a South-African sample.

    Science.gov (United States)

    Duh, Helen Inseng; Grubliauskiene, Aiste; Dewitte, Siegfried

    2016-01-01

    It has been suggested that the consumption of unhealthy Westernized diet in a context of poverty and resultant food insecurity may have contributed to South-Africa's status of the third fattest country in the World. Considering that a number of South-Africans are reported to have experienced, or are still experiencing food insecurity, procedures which have been shown to reduce the consumption of unhealthy food in higher income countries may be ineffective in South-Africa. We thus tested the robustness of the so called pre-exposure procedure in South-Africa. We also tested the moderating role of childhood poverty in the pre-exposure procedure. With the pre-exposure procedure, a respondent is exposed to a tempting unhealthy food (e.g. candy) in a context that is designed such that eating the food interferes with a task goal. The typical result is that this procedure spills over and reduces consumption of similar tempting food later on. An experimental study conducted in a South-African laboratory showed that the pre-exposure effect is robust even with a sample, where food insecurity prevails. Childhood poverty did not moderate the effect. This study proves that behavioral procedures aimed at reducing the consumption of unhealthy food would be valuable in less rich non-Western countries. Further testing of the robustness of the pre-exposure effect is however recommended in other poorer food insecure countries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. LOD score exclusion analyses for candidate QTLs using random population samples.

    Science.gov (United States)

    Deng, Hong-Wen

    2003-11-01

    While extensive analyses have been conducted to test for, no formal analyses have been conducted to test against, the importance of candidate genes as putative QTLs using random population samples. Previously, we developed an LOD score exclusion mapping approach for candidate genes for complex diseases. Here, we extend this LOD score approach for exclusion analyses of candidate genes for quantitative traits. Under this approach, specific genetic effects (as reflected by heritability) and inheritance models at candidate QTLs can be analyzed and if an LOD score is < or = -2.0, the locus can be excluded from having a heritability larger than that specified. Simulations show that this approach has high power to exclude a candidate gene from having moderate genetic effects if it is not a QTL and is robust to population admixture. Our exclusion analysis complements association analysis for candidate genes as putative QTLs in random population samples. The approach is applied to test the importance of Vitamin D receptor (VDR) gene as a potential QTL underlying the variation of bone mass, an important determinant of osteoporosis.

  13. A descriptive analysis of a representative sample of pediatric randomized controlled trials published in 2007

    Directory of Open Access Journals (Sweden)

    Thomson Denise

    2010-12-01

    Full Text Available Abstract Background Randomized controlled trials (RCTs are the gold standard for trials assessing the effects of therapeutic interventions; therefore it is important to understand how they are conducted. Our objectives were to provide an overview of a representative sample of pediatric RCTs published in 2007 and assess the validity of their results. Methods We searched Cochrane Central Register of Controlled Trials using a pediatric filter and randomly selected 300 RCTs published in 2007. We extracted data on trial characteristics; outcomes; methodological quality; reporting; and registration and protocol characteristics. Trial registration and protocol availability were determined for each study based on the publication, an Internet search and an author survey. Results Most studies (83% were efficacy trials, 40% evaluated drugs, and 30% were placebo-controlled. Primary outcomes were specified in 41%; 43% reported on adverse events. At least one statistically significant outcome was reported in 77% of trials; 63% favored the treatment group. Trial registration was declared in 12% of publications and 23% were found through an Internet search. Risk of bias (ROB was high in 59% of trials, unclear in 33%, and low in 8%. Registered trials were more likely to have low ROB than non-registered trials (16% vs. 5%; p = 0.008. Effect sizes tended to be larger for trials at high vs. low ROB (0.28, 95% CI 0.21,0.35 vs. 0.16, 95% CI 0.07,0.25. Among survey respondents (50% response rate, the most common reason for trial registration was a publication requirement and for non-registration, a lack of familiarity with the process. Conclusions More than half of this random sample of pediatric RCTs published in 2007 was at high ROB and three quarters of trials were not registered. There is an urgent need to improve the design, conduct, and reporting of child health research.

  14. 9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

    Science.gov (United States)

    2010-01-01

    ... samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... a representative sample of 30 eggs collected from a single day's production from the flock, must be... IgG antibodies set forth for testing serum in § 147.7 (for these tests the resultant supernatant...

  15. Statistical considerations for plot design, sampling procedures, analysis, and quality assurance of ozone injury studies

    Science.gov (United States)

    Michael Arbaugh; Larry Bednar

    1996-01-01

    The sampling methods used to monitor ozone injury to ponderosa and Jeffrey pines depend on the objectives of the study, geographic and genetic composition of the forest, and the source and composition of air pollutant emissions. By using a standardized sampling methodology, it may be possible to compare conditions within local areas more accurately, and to apply the...

  16. Health economic analysis of laparoscopic lavage versus Hartmann's procedure for diverticulitis in the randomized DILALA trial

    DEFF Research Database (Denmark)

    Gehrman, J.; Angenete, E; Björholt, I.

    2016-01-01

    Background: Open surgery with resection and colostomy (Hartmann's procedure) has been the standard treatment for perforated diverticulitis with purulent peritonitis. In recent years laparoscopic lavage has emerged as an alternative, with potential benefits for patients with purulent peritonitis......, Hinchey grade III. The aim of this study was to compare laparoscopic lavage and Hartmann's procedure with health economic evaluation within the framework of the DILALA (DIverticulitis – LAparoscopic LAvage versus resection (Hartmann's procedure) for acute diverticulitis with peritonitis) trial. Methods...... were robust as demonstrated in sensitivity analyses. Conclusion: The significant cost reduction in this study, together with results of safety and efficacy from RCTs, support the routine use of laparoscopic lavage as treatment for complicated diverticulitis with purulent peritonitis....

  17. A randomized controlled trial of pre-procedure simethicone and N-acetylcysteine to improve mucosal visibility during gastroscopy - NICEVIS.

    Science.gov (United States)

    Basford, Peter John; Brown, James; Gadeke, Lisa; Fogg, Carole; Haysom-Newport, Ben; Ogollah, Reuben; Bhattacharyya, Rupam; Longcroft-Wheaton, Gaius; Thursby-Pelham, Fergus; Neale, James R; Bhandari, Pradeep

    2016-11-01

    Background and study aims: Mucosal views can be impaired by residual bubbles and mucus during gastroscopy. This study aimed to determine whether a pre-gastroscopy drink containing simethicone and N-acetylcysteine improves mucosal visualisation. Patients and methods: We conducted a randomized controlled trial recruiting 126 subjects undergoing routine gastroscopy. Subjects were randomized 1:1:1 to receive: A-pre-procedure drink of water, simethicone and N-acetylcysteine (NAC); B-water alone; or C-no preparation. Study endoscopists were blinded to group allocation. Digital images were taken at 4 locations (lower esophagus/upper gastric body/antrum/fundus), and rated for mucosal visibility (MV) using a 4-point scale (1 = best, 4 = worst) by 4 separate experienced endoscopists. The primary outcome measure was mean mucosal visibility score (MVS). Secondary outcome measures were procedure duration and volume of fluid flush required to achieve adequate mucosal views. Results: Mean MVS for Group A was significantly better than for Group B (1.35 vs 2.11, P  NAC significantly improves mucosal visibility during gastroscopy and reduces the need for flushes during the procedure. Effectiveness in the lower esophagus demonstrates potential benefit in Barrett's oesophagus surveillance gastroscopy.

  18. Nonparametric relevance-shifted multiple testing procedures for the analysis of high-dimensional multivariate data with small sample sizes

    Directory of Open Access Journals (Sweden)

    Kropf Siegfried

    2008-01-01

    Full Text Available Abstract Background In many research areas it is necessary to find differences between treatment groups with several variables. For example, studies of microarray data seek to find a significant difference in location parameters from zero or one for ratios thereof for each variable. However, in some studies a significant deviation of the difference in locations from zero (or 1 in terms of the ratio is biologically meaningless. A relevant difference or ratio is sought in such cases. Results This article addresses the use of relevance-shifted tests on ratios for a multivariate parallel two-sample group design. Two empirical procedures are proposed which embed the relevance-shifted test on ratios. As both procedures test a hypothesis for each variable, the resulting multiple testing problem has to be considered. Hence, the procedures include a multiplicity correction. Both procedures are extensions of available procedures for point null hypotheses achieving exact control of the familywise error rate. Whereas the shift of the null hypothesis alone would give straight-forward solutions, the problems that are the reason for the empirical considerations discussed here arise by the fact that the shift is considered in both directions and the whole parameter space in between these two limits has to be accepted as null hypothesis. Conclusion The first algorithm to be discussed uses a permutation algorithm, and is appropriate for designs with a moderately large number of observations. However, many experiments have limited sample sizes. Then the second procedure might be more appropriate, where multiplicity is corrected according to a concept of data-driven order of hypotheses.

  19. Kinetic studies in solid state reactions by sample-controlled methods and advanced analysis procedures

    OpenAIRE

    Pérez-Maqueda, Luis A.; Criado, J. M.; Sánchez-Jiménez, P.E.; Perejón, Antonio

    2013-01-01

    A comparative study of both conventional rising temperature and sample-controlled methods, like constant rate thermal analysis (CRTA), is carried out after analyzing a set of solid state reactions using both methods. It is shown that CRTA avoids the influence of heat and mass transfer phenomena for a wide range of sample sizes leading to reliable kinetic parameters. On the other hand, conventional rising temperature methods yield α–T plots dependent on experimental conditions, even when using...

  20. Validation of the 2008 Landsat Burned Area Ecv Product for North America Using Stratified Random Sampling

    Science.gov (United States)

    Brunner, N. M.; Mladinich, C. S.; Caldwell, M. K.; Beal, Y. J. G.

    2014-12-01

    The U.S. Geological Survey is generating a suite of Essential Climate Variables (ECVs) products, as defined by the Global Climate Observing System, from the Landsat data archive. Validation protocols for these products are being established, incorporating the Committee on Earth Observing Satellites Land Product Validation Subgroup's best practice guidelines and validation hierarchy stages. The sampling design and accuracy measures follow the methodology developed by the European Space Agency's Climate Change Initiative Fire Disturbance (fire_cci) project (Padilla and others, 2014). A rigorous validation was performed on the 2008 Burned Area ECV (BAECV) prototype product, using a stratified random sample of 48 Thiessen scene areas overlaying Landsat path/rows distributed across several terrestrial biomes throughout North America. The validation reference data consisted of fourteen sample sites acquired from the fire_cci project and the remaining new samples sites generated from a densification of the stratified sampling for North America. The reference burned area polygons were generated using the ABAMS (Automatic Burned Area Mapping) software (Bastarrika and others, 2011; Izagirre, 2014). Accuracy results will be presented indicating strengths and weaknesses of the BAECV algorithm.Bastarrika, A., Chuvieco, E., and Martín, M.P., 2011, Mapping burned areas from Landsat TM/ETM+ data with a two-phase algorithm: Balancing omission and commission errors: Remote Sensing of Environment, v. 115, no. 4, p. 1003-1012.Izagirre, A.B., 2014, Automatic Burned Area Mapping Software (ABAMS), Preliminary Documentation, Version 10 v4,: Vitoria-Gasteiz, Spain, University of Basque Country, p. 27.Padilla, M., Chuvieco, E., Hantson, S., Theis, R., and Sandow, C., 2014, D2.1 - Product Validation Plan: UAH - University of Alcalá de Henares (Spain), 37 p.

  1. Conic sampling: an efficient method for solving linear and quadratic programming by randomly linking constraints within the interior.

    Science.gov (United States)

    Serang, Oliver

    2012-01-01

    Linear programming (LP) problems are commonly used in analysis and resource allocation, frequently surfacing as approximations to more difficult problems. Existing approaches to LP have been dominated by a small group of methods, and randomized algorithms have not enjoyed popularity in practice. This paper introduces a novel randomized method of solving LP problems by moving along the facets and within the interior of the polytope along rays randomly sampled from the polyhedral cones defined by the bounding constraints. This conic sampling method is then applied to randomly sampled LPs, and its runtime performance is shown to compare favorably to the simplex and primal affine-scaling algorithms, especially on polytopes with certain characteristics. The conic sampling method is then adapted and applied to solve a certain quadratic program, which compute a projection onto a polytope; the proposed method is shown to outperform the proprietary software Mathematica on large, sparse QP problems constructed from mass spectometry-based proteomics.

  2. Improvement of sampling strategies for randomly distributed hotspots in soil applying a computerized simulation considering the concept of uncertainty.

    Science.gov (United States)

    Hildebrandt, Thomas; Pick, Denis; Einax, Jürgen W

    2012-02-01

    The pollution of soil and environment as a result of human activity is a major problem. Nowadays, the determination of local contaminations is of interest for environmental remediation. These hotspots can have various toxic effects on plants, animals, humans, and the whole ecological system. However, economical and juridical consequences are also possible, e.g., high costs for remediation measures. In this study three sampling strategies (simple random sampling, stratified sampling, and systematic sampling) were applied on randomly distributed hotspot contaminations to prove their efficiency in term of finding hotspots. The results were used for the validation of a computerized simulation. This application can simulate the contamination on a field, the sampling pattern, and a virtual sampling. A constant hit rate showed that none of the sampling patterns could reach better results than others. Furthermore, the uncertainty associated with the results is described by confidence intervals. It is to be considered that the uncertainty during sampling is enormous and will decrease slightly, even the number of samples applied was increased to an unreasonable amount. It is hardly possible to identify the exact number of randomly distributed hotspot contaminations by statistical sampling. But a range of possible results could be calculated. Depending on various parameters such as shape and size of the area, number of hotspots, and sample quantity, optimal sampling strategies could be derived. Furthermore, an estimation of bias arising from sampling methodology is possible. The developed computerized simulation is an innovative tool for optimizing sampling strategies in terrestrial compartments for hotspot distributions.

  3. RANdom SAmple Consensus (RANSAC) algorithm for material-informatics: application to photovoltaic solar cells.

    Science.gov (United States)

    Kaspi, Omer; Yosipof, Abraham; Senderowitz, Hanoch

    2017-06-06

    An important aspect of chemoinformatics and material-informatics is the usage of machine learning algorithms to build Quantitative Structure Activity Relationship (QSAR) models. The RANdom SAmple Consensus (RANSAC) algorithm is a predictive modeling tool widely used in the image processing field for cleaning datasets from noise. RANSAC could be used as a "one stop shop" algorithm for developing and validating QSAR models, performing outlier removal, descriptors selection, model development and predictions for test set samples using applicability domain. For "future" predictions (i.e., for samples not included in the original test set) RANSAC provides a statistical estimate for the probability of obtaining reliable predictions, i.e., predictions within a pre-defined number of standard deviations from the true values. In this work we describe the first application of RNASAC in material informatics, focusing on the analysis of solar cells. We demonstrate that for three datasets representing different metal oxide (MO) based solar cell libraries RANSAC-derived models select descriptors previously shown to correlate with key photovoltaic properties and lead to good predictive statistics for these properties. These models were subsequently used to predict the properties of virtual solar cells libraries highlighting interesting dependencies of PV properties on MO compositions.

  4. Novel field sampling procedure for the determination of methiocarb residues in surface waters from rice fields.

    Science.gov (United States)

    Primus, T M; Kohler, D J; Avery, M; Bolich, P; Way, M O; Johnston, J J

    2001-12-01

    Methiocarb was extracted from surface water samples collected at experimental rice field sites in Louisiana and Texas. The sampling system consisted of a single-stage 90-mm Empore extraction disk unit equipped with a battery-powered vacuum pump. After extraction, the C-18 extraction disks were stored in an inert atmosphere at -10 degrees C and shipped overnight to the laboratory. The disks were extracted with methanol and the extracts analyzed by reversed-phase high-performance liquid chromatography with a methanol/water mobile phase. Methiocarb was detected by ultraviolet absorption at 223 nm and quantified with the use of calibration standards. Recoveries from control surface water samples fortified at 5.0, 10, 50, and 100 ng/mL methiocarb averaged 92 +/- 7%. A method limit of detection for methiocarb in rice field surface water was estimated to be 0.23 ng/mL at 223 nm.

  5. Multistate evaluation of an ultrafiltration-based procedure for simultaneous recovery of enteric microbes in 100-liter tap water samples.

    Science.gov (United States)

    Hill, Vincent R; Kahler, Amy M; Jothikumar, Narayanan; Johnson, Trisha B; Hahn, Donghyun; Cromeans, Theresa L

    2007-07-01

    Ultrafiltration (UF) is increasingly being recognized as a potentially effective procedure for concentrating and recovering microbes from large volumes of water and treated wastewater. Because of their very small pore sizes, UF membranes are capable of simultaneously concentrating viruses, bacteria, and parasites based on size exclusion. In this study, a UF-based water sampling procedure was used to simultaneously recover representatives of these three microbial classes seeded into 100-liter samples of tap water collected from eight cities covering six hydrologic areas of the United States. The UF-based procedure included hollow-fiber UF as the primary step for concentrating microbes and then used membrane filtration for bacterial culture assays, immunomagnetic separation for parasite recovery and quantification, and centrifugal UF for secondary concentration of viruses. Water samples were tested for nine water quality parameters to investigate whether water quality data correlated with measured recovery efficiencies and molecular detection levels. Average total method recovery efficiencies were 71, 97, 120, 110, and 91% for phiX174 bacteriophage, MS2 bacteriophage, Enterococcus faecalis, Clostridium perfringens spores, and Cryptosporidium parvum oocysts, respectively. Real-time PCR and reverse transcription-PCR (RT-PCR) for seeded microbes and controls indicated that tap water quality could affect the analytical performance of molecular amplification assays, although no specific water quality parameter was found to correlate with reduced PCR or RT-PCR performance.

  6. [Sampling procedure for a survey of an interventional study on acute respiratory infections].

    Science.gov (United States)

    Ramón Bravo, J; González Ochoa, E

    1993-01-01

    A description is made of the methodology used for obtaining a sample made up of 500 children under 5 years and 500 adults 65 year old and more, in order to carry out an intervention study on acute respiratory tract infections in an urban zone in Havana City and in a rural zone in Matanzas province, where different intervention stops will be taken with regards sanitary education about management of acute respiratory tract infections for the population and training for primary care medical personnel. We show the way the selected sample fits was planned with a very homogeneous distribution in the 8 areas under study, which allows for great reliability in the results.

  7. Adverse Events With Ketamine Versus Ketofol for Procedural Sedation on Adults: A Double-blind, Randomized Controlled Trial.

    Science.gov (United States)

    Lemoel, Fabien; Contenti, Julie; Giolito, Didier; Boiffier, Mathieu; Rapp, Jocelyn; Istria, Jacques; Fournier, Marc; Ageron, François-Xavier; Levraut, Jacques

    2017-12-01

    The goal of our study was to compare the frequency and severity of recovery reactions between ketamine and ketamine-propofol 1:1 admixture ("ketofol"). We performed a multicentric, randomized, double-blind trial in which adult patients received emergency procedural sedations with ketamine or ketofol. Our primary outcome was the proportion of unpleasant recovery reactions. Other outcomes were frequency of interventions required by these recovery reactions, rates of respiratory or hemodynamic events, emesis, and satisfaction of patients as well as providers. A total of 152 patients completed the study, 76 in each arm. Compared with ketamine, ketofol determined a 22% reduction in recovery reactions incidence (p ketamine. We found a significant reduction in recovery reactions and emesis frequencies among adult patients receiving emergency procedural sedations with ketofol, compared with ketamine. © 2017 by the Society for Academic Emergency Medicine.

  8. Sample size and power for a stratified doubly randomized preference design.

    Science.gov (United States)

    Cameron, Briana; Esserman, Denise A

    2016-11-21

    The two-stage (or doubly) randomized preference trial design is an important tool for researchers seeking to disentangle the role of patient treatment preference on treatment response through estimation of selection and preference effects. Up until now, these designs have been limited by their assumption of equal preference rates and effect sizes across the entire study population. We propose a stratified two-stage randomized trial design that addresses this limitation. We begin by deriving stratified test statistics for the treatment, preference, and selection effects. Next, we develop a sample size formula for the number of patients required to detect each effect. The properties of the model and the efficiency of the design are established using a series of simulation studies. We demonstrate the applicability of the design using a study of Hepatitis C treatment modality, specialty clinic versus mobile medical clinic. In this example, a stratified preference design (stratified by alcohol/drug use) may more closely capture the true distribution of patient preferences and allow for a more efficient design than a design which ignores these differences (unstratified version). © The Author(s) 2016.

  9. Notes on interval estimation of the generalized odds ratio under stratified random sampling.

    Science.gov (United States)

    Lui, Kung-Jong; Chang, Kuang-Chao

    2013-05-01

    It is not rare to encounter the patient response on the ordinal scale in a randomized clinical trial (RCT). Under the assumption that the generalized odds ratio (GOR) is homogeneous across strata, we consider four asymptotic interval estimators for the GOR under stratified random sampling. These include the interval estimator using the weighted-least-squares (WLS) approach with the logarithmic transformation (WLSL), the interval estimator using the Mantel-Haenszel (MH) type of estimator with the logarithmic transformation (MHL), the interval estimator using Fieller's theorem with the MH weights (FTMH) and the interval estimator using Fieller's theorem with the WLS weights (FTWLS). We employ Monte Carlo simulation to evaluate the performance of these interval estimators by calculating the coverage probability and the average length. To study the bias of these interval estimators, we also calculate and compare the noncoverage probabilities in the two tails of the resulting confidence intervals. We find that WLSL and MHL can generally perform well, while FTMH and FTWLS can lose either precision or accuracy. We further find that MHL is likely the least biased. Finally, we use the data taken from a study of smoking status and breathing test among workers in certain industrial plants in Houston, Texas, during 1974 to 1975 to illustrate the use of these interval estimators.

  10. RISK-ASSESSMENT PROCEDURES AND ESTABLISHING THE SIZE OF SAMPLES FOR AUDITING FINANCIAL STATEMENTS

    Directory of Open Access Journals (Sweden)

    Daniel Botez

    2014-12-01

    Full Text Available In auditing financial statements, the procedures for the assessment of the risks and the calculation of the materiality differ from an auditor to another, by audit cabinet policy or advice professional bodies. All, however, have the reference International Audit Standards ISA 315 “Identifying and assessing the risks of material misstatement through understanding the entity and its environment” and ISA 320 “Materiality in planning and performing an audit”. On the basis of specific practices auditors in Romania, the article shows some laborious and examples of these aspects. Such considerations are presented evaluation of the general inherent risk, a specific inherent risk, the risk of control and the calculation of the materiality.

  11. Control capacity and a random sampling method in exploring controllability of complex networks.

    Science.gov (United States)

    Jia, Tao; Barabási, Albert-László

    2013-01-01

    Controlling complex systems is a fundamental challenge of network science. Recent advances indicate that control over the system can be achieved through a minimum driver node set (MDS). The existence of multiple MDS's suggests that nodes do not participate in control equally, prompting us to quantify their participations. Here we introduce control capacity quantifying the likelihood that a node is a driver node. To efficiently measure this quantity, we develop a random sampling algorithm. This algorithm not only provides a statistical estimate of the control capacity, but also bridges the gap between multiple microscopic control configurations and macroscopic properties of the network under control. We demonstrate that the possibility of being a driver node decreases with a node's in-degree and is independent of its out-degree. Given the inherent multiplicity of MDS's, our findings offer tools to explore control in various complex systems.

  12. Classification of epileptic EEG signals based on simple random sampling and sequential feature selection.

    Science.gov (United States)

    Ghayab, Hadi Ratham Al; Li, Yan; Abdulla, Shahab; Diykh, Mohammed; Wan, Xiangkui

    2016-06-01

    Electroencephalogram (EEG) signals are used broadly in the medical fields. The main applications of EEG signals are the diagnosis and treatment of diseases such as epilepsy, Alzheimer, sleep problems and so on. This paper presents a new method which extracts and selects features from multi-channel EEG signals. This research focuses on three main points. Firstly, simple random sampling (SRS) technique is used to extract features from the time domain of EEG signals. Secondly, the sequential feature selection (SFS) algorithm is applied to select the key features and to reduce the dimensionality of the data. Finally, the selected features are forwarded to a least square support vector machine (LS_SVM) classifier to classify the EEG signals. The LS_SVM classifier classified the features which are extracted and selected from the SRS and the SFS. The experimental results show that the method achieves 99.90, 99.80 and 100 % for classification accuracy, sensitivity and specificity, respectively.

  13. What Is the Outcome of an Incision and Drainage Procedure in Endodontic Patients? A Prospective, Randomized, Single-blind Study.

    Science.gov (United States)

    Beus, Hannah; Fowler, Sara; Drum, Melissa; Reader, Al; Nusstein, John; Beck, Mike; Jatana, Courtney

    2018-02-01

    There are no prospective endodontic studies to determine the outcome of an incision and drainage (I&D) procedure for swelling in healthy, endodontic patients. The purpose of this prospective, randomized, single-blind study was to compare the postoperative course of I&D with drain placement versus a mock I&D procedure with mock drain placement after endodontic debridement in swollen emergency patients with symptomatic teeth and a pulpal diagnosis of necrosis. Eighty-one adult emergency patients presenting with clinical swelling received either penicillin or, if allergic, clindamycin and complete endodontic debridement, and then were randomly divided into 2 treatment groups: I&D with drain placement or a mock I&D procedure with mock drain placement. At the end of the appointment, all patients received a combination of ibuprofen/acetaminophen and, if needed, an opioid-containing escape medication. Patients recorded their pain and medication use for 4 days postoperatively. Success was defined as no or mild postoperative pain and no use of an opioid-containing escape medication. Success was evaluated using repeated measure mixed model logistic regression. Both groups had a decrease in postoperative pain and medication use over the 4 days. The mock I&D group had significantly higher success than the I&D group (odds ratio = 2.00; 95% confidence interval, 1.16-3.41). The success rate was 45% with the mock I&D and 33% with the I&D. After endodontic debridement, patients who received a mock I&D procedure with mock drain placement had more success than patients who received I&D with drain placement. Both groups clinically improved over 4 days. Copyright © 2017 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  14. Occurrence of Arcobacter in Iranian poultry and slaughterhouse samples implicates contamination by processing equipment and procedures.

    Science.gov (United States)

    Khoshbakht, R; Tabatabaei, M; Shirzad Aski, H; Seifi, S

    2014-01-01

    1. The occurrence of Arcobacter spp. and three pathogenic species of Arcobacter from Iranian poultry carcasses was investigated at different steps of broiler processing to determine critical control points for reducing carcass contamination. 2. Samples were collected from (a) cloaca immediately before processing, (b) different points during processing and (c) at different stations in a processing plant of a slaughterhouse in southern Iran. 3. After enrichment steps in Arcobacter selective broth, DNA of the samples was extracted and three significant pathogen species of Arcobacter were identified based on polymerase chain reaction (PCR) detection of 16S rRNA and specific species PCR. 4. Out of a total of 540 samples, 244 (45%) were positive for Arcobacter spp. Arcobacter butzleri was more frequently detected (73% ± 13.9%) than A. cryaeophilus (9% ± 13.9%) and A. skirrowii (4.1%). In addition, co-colonisation (A. butzleri and A. cryaerophilus) occurred in 13.9% of the positive samples. 5. The results indicate a high prevalence of Arcobacter in the investigated slaughterhouse and broiler carcasses and that Arcobacter is not a normal flora of the broilers. Evidence for the presence of Arcobacter in the environment and water of processing plants suggests that these are sources of contamination of poultry carcasses. In addition, contamination of the poultry carcasses can spread between poultry meats in different parts and processes of the slaughterhouse (pre-scalding to after evisceration).

  15. Comparison of two different procedures for quantification of drugs of abuse in postmortem brain samples

    DEFF Research Database (Denmark)

    Reiter, Birgit; Stimpfl, Thomas; Holm, Karen Marie Dollerup

    The aim of this study was to compare a routine method for qualitative and quantitative analysis of body-fluids and tissue samples developed in Vienna to a routine method developed for blood used in Copenhagen. No optimization was performed beforehand on the Copenhagen method to accommodate for the...... for the use of brain tissue....

  16. Continuous quality control of the blood sampling procedure using a structured observation scheme

    DEFF Research Database (Denmark)

    Seemann, Tine Lindberg; Nybo, Mads

    2016-01-01

    blood drawings by 39 phlebotomists were observed in the pilot study, while 84 blood drawings by 34 phlebotomists were observed in the follow-up study. In the pilot study, the three major error items were hand hygiene (42% error), mixing of samples (22%), and order of draw (21%). Minor significant...

  17. Sampling procedure in a willow plantation for chemical elements important for biomass combustion quality

    DEFF Research Database (Denmark)

    Liu, Na; Nielsen, Henrik Kofoed; Jørgensen, Uffe

    2015-01-01

    Willow (Salix spp.) is expected to contribute significantly to the woody bioenergy system in the future, so more information on how to sample the quality of the willow biomass is needed. The objectives of this study were to investigate the spatial variation of elements within shoots of a willow...

  18. 1979 Reserve Force Studies Surveys: Survey Design, Sample Design and Administrative Procedures,

    Science.gov (United States)

    1981-08-01

    Dental Service 17 Reception Cnt. 11Other 46 Total 2914 The heterogeneity of the units poses a problem for a unit sampling plan. Namely, if the...regular schoel or collae 04. What is tha ZIP Code ZIP Cods thats you think you will ama c0oMsil In tha futura? If af tha placa whare your highest grade

  19. Information Sampling and Group Decision Making: The Effects of an Advocacy Decision Procedure and Task Experience

    Science.gov (United States)

    Greitemeyer, Tobias; Schulz-Hardt, Stefan; Brodbeck, Felix C.; Frey, Dieter

    2006-01-01

    Group discussions tend to focus on information that was previously known by all members (shared information) rather than information known by only 1 member (unshared information). If the shared information implies a suboptimal alternative, this sampling bias is associated with inaccurate group decisions. The present study examines the impact of 2…

  20. Fish Farm Inspections and Sampling Procedures: The Mediterranean Point of View

    DEFF Research Database (Denmark)

    Vendramin, Niccolò

    2012-01-01

    Marine Mediterranean aquaculture meant as intesive rearing system for zootechnical production has known a recent development extremely fast. The development of efficacious breeding protocols, the availability of artificial feeding more and more efficient and some principles adopted in facing dise...... firstly. In this presentation, mainly based on pictures, different aspects of clinical inspection/sampling protocols are described....

  1. 40 CFR 89.411 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ... reading. (5) Zero and span each range to be used on each analyzer operated prior to the beginning of the... bag sample technique outlined in paragraph (c) of this section. (e) Hydrocarbon hangup. If HC hangup... the difference between the readings obtained greater than or equal to 2 percent of full scale...

  2. Ficolin-2 reveals different analytical and biological properties dependent on different sample handling procedures

    DEFF Research Database (Denmark)

    Hein, Estrid; Bay, Jakob T; Munthe-Fog, Lea

    2013-01-01

    mediated formation of the terminal complement complex was observed under the applied assay conditions. In conclusion, our results show that Ficolin-2 is a promiscuous molecule and that care should be taken during sampling, handling and matrix chosen for measurement of Ficolin-2 levels and activity....

  3. Comparison of noninvasive sample collection procedures for canine leishmaniasis diagnosis by PCR-hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Sidney de Almeida; Andrade, Antero Silva Ribeiro de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: vidasnino@yahoo.com.br; antero@cdtn.br; Ituassu, Leonardo Trindade; Melo, Maria Norma de [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)]. E-mail: melo@mono.icb.ufmg.br; ltituassu@yahoo.com.br

    2007-07-01

    The dogs are the main reservoir of the visceral leishmaniasis etiological agent Leishmania chagasi and these animals have to be systematically monitored. The aim of present work was to standardize a method for canine leishmaniasis diagnosis using DNA samples obtained by a noninvasive ways. Two kind of samples were compared: conjunctival swab and blood. The samples were analyzed by the Polymerase Chain Reaction (PCR) associated with the hybridization of {sup 32}P labeled DNA probes. An in vitro test was carried out using cotton swabs seeded with L. chagasi parasites at different cell numbers. After that, the PCR and hybridization sensitivity was evaluated in two groups of 23 seropositive dogs. Conjunctival swabs and 1,0 mL of blood were collected from each animal. 90 {mu}L of these blood were spotted onto filter paper and the remaining used to prepare the buffy coat. The DNA purification from cotton swabs was carried out through the phenol-chloroform (group 1) or boiling (group 2). The Wizard kit was used to DNA extraction from buffy coat. The filters were treated according to Dialab protocol. The analysis of the seeded samples showed that the PCR was able to identify until ten parasites while the following hybridization of the PCR products allows the detection of until one parasite. The PCR positivity for the conjunctival swabs were 73.9% and 52.2% respectively to the groups 1 and 2. For buffy coat the positivities were 43.5% and 56.5% respectively. The filters presented the lowest positivity. The hybridization step was not accomplished yet for these samples. (author)

  4. Randomized Controlled Trial of Attention Bias Modification in a Racially Diverse, Socially Anxious, Alcohol Dependent Sample

    Science.gov (United States)

    Clerkin, Elise M.; Magee, Joshua C.; Wells, Tony T.; Beard, Courtney; Barnett, Nancy P.

    2016-01-01

    Objective Attention biases may be an important treatment target for both alcohol dependence and social anxiety. This is the first ABM trial to investigate two (vs. one) targets of attention bias within a sample with co-occurring symptoms of social anxiety and alcohol dependence. Additionally, we used trial-level bias scores (TL-BS) to capture the phenomena of attention bias in a more ecologically valid, dynamic way compared to traditional attention bias scores. Method Adult participants (N=86; 41% Female; 52% African American; 40% White) with elevated social anxiety symptoms and alcohol dependence were randomly assigned to an 8-session training condition in this 2 (Social Anxiety ABM vs. Social Anxiety Control) by 2 (Alcohol ABM vs. Alcohol Control) design. Symptoms of social anxiety, alcohol dependence, and attention bias were assessed across time. Results Multilevel models estimated the trajectories for each measure within individuals, and tested whether these trajectories differed according to the randomized training conditions. Across time, there were significant or trending decreases in all attention TL-BS parameters (but not traditional attention bias scores) and most symptom measures. However, there were not significant differences in the trajectories of change between any ABM and control conditions for any symptom measures. Conclusions These findings add to previous evidence questioning the robustness of ABM and point to the need to extend the effects of ABM to samples that are racially diverse and/or have co-occurring psychopathology. The results also illustrate the potential importance of calculating trial-level attention bias scores rather than only including traditional bias scores. PMID:27591918

  5. Random sampling or geostatistical modelling? Choosing between design-based and model-based sampling strategies for soil (with discussion)

    NARCIS (Netherlands)

    Brus, D.J.; Gruijter, de J.J.

    1997-01-01

    Classical sampling theory has been repeatedly identified with classical statistics which assumes that data are identically and independently distributed. This explains the switch of many soil scientists from design-based sampling strategies, based on classical sampling theory, to the model-based

  6. Study on different pre-treatment procedures for metal determination in Orujo spirit samples by ICP-AES

    Energy Technology Data Exchange (ETDEWEB)

    Barciela, Julia; Vilar, Manuela; Garcia-Martin, Sagrario [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Pena, Rosa M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)], E-mail: qarosa@lugo.usc.es; Herrero, Carlos [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)], E-mail: cherrero@lugo.usc.es

    2008-10-17

    In this work several pre-treatment methods were studied for metal (Na, K, Mg, Cu and Ca) determination in Orujo spirit samples using inductively coupled plasma atomic emission spectrometry (ICP-AES). Dilution, digestion, evaporation, and cryogenic desolvatation techniques were comparatively evaluated. Because of their analytical characteristics, digestion and evaporation with nitrogen current were found to be appropriate procedures for the determination of metals in alcoholic spirit samples. Yet, if simplicity and application time are to be considered, the latter-evaporation in a water bath with a nitrogen current-stands out as the optimum procedure for any further determinations in Orujo samples by ICP-AES. Low detection levels and wide linear ranges (sufficient to determine these metals in the samples studied) were achieved for each metal. The recoveries (in the 97.5-100.5% range) and the precision (R.S.D. lower than 5.6%) obtained were also satisfactory. The selected procedure was applied to determine the content of metals in 80 representative Galician Orujo spirit samples with and without a Certified Brand of Origin (CBO) which had been produced using different distillation systems. The metal concentrations ranged between 0.37 and 79.7 mg L{sup -1} for Na,

  7. Mercury speciation in seafood samples by LC-ICP-MS with a rapid ultrasound-assisted extraction procedure: Application to the determination of mercury in Brazilian seafood samples.

    Science.gov (United States)

    Batista, Bruno Lemos; Rodrigues, Jairo L; de Souza, Samuel S; Oliveira Souza, Vanessa C; Barbosa, Fernando

    2011-06-15

    This paper describes a simple method for mercury speciation in seafood samples by LC-ICP-MS with a fast sample preparation procedure. Prior to analysis, mercury species were extracted from food samples with a solution containing mercaptoethanol, l-cysteine and HCl and sonication for 15min. Separation of mercury species was accomplished in less than 5min on a C8 reverse phase column with a mobile phase containing 0.05%-v/v mercaptoethanol, 0.4%m/v l-cysteine and 0.06molL(-1) ammonium acetate. The method detection limits were found to be 0.25, 0.20 and 0.1ngg(-1) for inorganic mercury, ethylmercury and methylmercury, respectively. Method accuracy is traceable to Certified Reference Materials (DOLT-3 and DORM-3) from the National Research Council Canada (NRCC). With the proposed method there is a considerable reduction of the time of sample preparation. Finally, the method was applied for the speciation of mercury in seafood samples purchased from the Brazilian market. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Multiple-image authentication with a cascaded multilevel architecture based on amplitude field random sampling and phase information multiplexing.

    Science.gov (United States)

    Fan, Desheng; Meng, Xiangfeng; Wang, Yurong; Yang, Xiulun; Pan, Xuemei; Peng, Xiang; He, Wenqi; Dong, Guoyan; Chen, Hongyi

    2015-04-10

    A multiple-image authentication method with a cascaded multilevel architecture in the Fresnel domain is proposed, in which a synthetic encoded complex amplitude is first fabricated, and its real amplitude component is generated by iterative amplitude encoding, random sampling, and space multiplexing for the low-level certification images, while the phase component of the synthetic encoded complex amplitude is constructed by iterative phase information encoding and multiplexing for the high-level certification images. Then the synthetic encoded complex amplitude is iteratively encoded into two phase-type ciphertexts located in two different transform planes. During high-level authentication, when the two phase-type ciphertexts and the high-level decryption key are presented to the system and then the Fresnel transform is carried out, a meaningful image with good quality and a high correlation coefficient with the original certification image can be recovered in the output plane. Similar to the procedure of high-level authentication, in the case of low-level authentication with the aid of a low-level decryption key, no significant or meaningful information is retrieved, but it can result in a remarkable peak output in the nonlinear correlation coefficient of the output image and the corresponding original certification image. Therefore, the method realizes different levels of accessibility to the original certification image for different authority levels with the same cascaded multilevel architecture.

  9. Random Photon Absorption Model Elucidates How Early Gain Control in Fly Photoreceptors Arises from Quantal Sampling

    Science.gov (United States)

    Song, Zhuoyi; Zhou, Yu; Juusola, Mikko

    2016-01-01

    Many diurnal photoreceptors encode vast real-world light changes effectively, but how this performance originates from photon sampling is unclear. A 4-module biophysically-realistic fly photoreceptor model, in which information capture is limited by the number of its sampling units (microvilli) and their photon-hit recovery time (refractoriness), can accurately simulate real recordings and their information content. However, sublinear summation in quantum bump production (quantum-gain-nonlinearity) may also cause adaptation by reducing the bump/photon gain when multiple photons hit the same microvillus simultaneously. Here, we use a Random Photon Absorption Model (RandPAM), which is the 1st module of the 4-module fly photoreceptor model, to quantify the contribution of quantum-gain-nonlinearity in light adaptation. We show how quantum-gain-nonlinearity already results from photon sampling alone. In the extreme case, when two or more simultaneous photon-hits reduce to a single sublinear value, quantum-gain-nonlinearity is preset before the phototransduction reactions adapt the quantum bump waveform. However, the contribution of quantum-gain-nonlinearity in light adaptation depends upon the likelihood of multi-photon-hits, which is strictly determined by the number of microvilli and light intensity. Specifically, its contribution to light-adaptation is marginal (≤ 1%) in fly photoreceptors with many thousands of microvilli, because the probability of simultaneous multi-photon-hits on any one microvillus is low even during daylight conditions. However, in cells with fewer sampling units, the impact of quantum-gain-nonlinearity increases with brightening light. PMID:27445779

  10. Effect of Spike Lavender Lakhlakhe on Pain Intensity Due to Phlebotomy Procedure in Premature Infants Hospitalized in Neonatal Intensive Care Unit: A Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Noushin Beheshtipoor

    2017-06-01

    Full Text Available Background: A Premature infants undergo multiple painful procedures during treatment; thus, it must be tried to limit complications caused by diagnostic and treatment procedures using simple and practical methods. This study was performed to evaluate the effect of spike lavender lakhlakhe on pain intensity due to phlebotomy in hospitalized premature infants.Methods: This single-arm, randomized clinical trial was performed on 30 infants chosen through convenience sampling method. Each newborn was considered as its own control. For the test group, one drop of pure (100% spike lavender lakhlakhe was taken by a standard dropper and diluted with 4 ml of warm distilled water by the research assistant. This mixture was stirred at 2-3 cm distance of the newborns’ nose from 60 minutes before until 2 minutes after phlebotomy, such that it could be smelled by the newborns. In both groups, heart rate and blood oxygen saturation were measured by a standard portable device, and the corresponding data was recorded in data collection sheets. Moreover, the infants’ facial expression changes were recorded by a camera and the intensity of pain was measured by Premature Infant Pain Profile before and after the procedure. Finally, the data was analyzed by paired comparison analysis test in SPSS, version 17.Results: Comparison of mean pain intensity caused by phlebotomy in the control and test groups showed a significant difference (7.667±0.311 vs. 4.882±0.311; P

  11. An investigation into the sample preparation procedure and analysis of cyanoacrylate adhesives using capillary electrophoresis

    OpenAIRE

    Whitaker, Gillian; Kincaid, Brendan J.; Van Hoof, Nicole; Regan, Fiona; Smyth, Malcolm R.; Leonard, Raymond G.

    2007-01-01

    In this study, the trace acid profile of cyanoacrylate adhesives was studied using capillary electrophoresis. Liquid–liquid extraction was employed as the sample preparation step before separation by capillary electrophoresis. The solubility of the adhesives was investigated using various organic solvents, e.g. hexane and dichloromethane, and chloroform was determined to be the optimum solvent as it enabled the full dissolution of the adhesive. A comprehensive stability study was performed ov...

  12. The development of metabolomic sampling procedures for Pichia pastoris, and baseline metabolome data.

    Directory of Open Access Journals (Sweden)

    Gregory D Tredwell

    Full Text Available Metabolic profiling is increasingly being used to investigate a diverse range of biological questions. Due to the rapid turnover of intracellular metabolites it is important to have reliable, reproducible techniques for sampling and sample treatment. Through the use of non-targeted analytical techniques such as NMR and GC-MS we have performed a comprehensive quantitative investigation of sampling techniques for Pichia pastoris. It was clear that quenching metabolism using solutions based on the standard cold methanol protocol caused some metabolite losses from P. pastoris cells. However, these were at a low level, with the NMR results indicating metabolite increases in the quenching solution below 5% of their intracellular level for 75% of metabolites identified; while the GC-MS results suggest a slightly higher level with increases below 15% of their intracellular values. There were subtle differences between the four quenching solutions investigated but broadly, they all gave similar results. Total culture extraction of cells + broth using high cell density cultures typical of P. pastoris fermentations, was an efficient sampling technique for NMR analysis and provided a gold standard of intracellular metabolite levels; however, salts in the media affected the GC-MS analysis. Furthermore, there was no benefit in including an additional washing step in the quenching process, as the results were essentially identical to those obtained just by a single centrifugation step. We have identified the major high-concentration metabolites found in both the extra- and intracellular locations of P. pastoris cultures by NMR spectroscopy and GC-MS. This has provided us with a baseline metabolome for P. pastoris for future studies. The P. pastoris metabolome is significantly different from that of Saccharomyces cerevisiae, with the most notable difference being the production of high concentrations of arabitol by P. pastoris.

  13. Effects of Analytical Procedures on the Repeatability of Malondialdehyde Determinations in Biological Samples

    Directory of Open Access Journals (Sweden)

    Sajad Azizi, Maryam Khoubnasabjafari, Aziz Shahrisa, Mehry Khoubnasabjafari, Jafar Soleymani, Abolghasem Jouyban

    2017-09-01

    Full Text Available Background: Malondialdehyde (MDA is a commonly used biomarker of oxidative stress in clinical studies and has been measured in many pathological conditions during last decades. Different analytical methods have been reported for determination of MDA in biological samples in which MDA was adducted with thiobarbituric acid (TBA to produce more sensitive chromophore and also convert it to a fluorescent compound. In spite of the routine applications of this derivatization and subsequent analysis of MDA in biomedical studies, its reliability, repeatability and reproducibility is questionable. The aim of this work is to investigate the effects of some factors on the repeatability of MDA determinations in standard solutions and also in plasma samples using spectroscopic method. Methods: MDA-TBA adduct is prepared in standard solutions and the effects of pH, temperature, reaction time, open, closed and reflux systems and the ratio of MDA and TBA is investigated by measuring the absorbance of the solution at 532 nm. These effects are also investigated in human plasma samples. Results: The best results are obtained at pH 2.5, temperature of 70 °C, reaction time of 150 minutes, reflux system and ratio of 2. Conclusion: Using the optimized conditions are resulted in better repeatability.

  14. SAMPL4 & DOCK3.7: lessons for automated docking procedures

    Science.gov (United States)

    Coleman, Ryan G.; Sterling, Teague; Weiss, Dahlia R.

    2014-03-01

    The SAMPL4 challenges were used to test current automated methods for solvation energy, virtual screening, pose and affinity prediction of the molecular docking pipeline DOCK 3.7. Additionally, first-order models of binding affinity were proposed as milestones for any method predicting binding affinity. Several important discoveries about the molecular docking software were made during the challenge: (1) Solvation energies of ligands were five-fold worse than any other method used in SAMPL4, including methods that were similarly fast, (2) HIV Integrase is a challenging target, but automated docking on the correct allosteric site performed well in terms of virtual screening and pose prediction (compared to other methods) but affinity prediction, as expected, was very poor, (3) Molecular docking grid sizes can be very important, serious errors were discovered with default settings that have been adjusted for all future work. Overall, lessons from SAMPL4 suggest many changes to molecular docking tools, not just DOCK 3.7, that could improve the state of the art. Future difficulties and projects will be discussed.

  15. Determining the optimal forensic DNA analysis procedure following investigation of sample quality.

    Science.gov (United States)

    Hedell, Ronny; Hedman, Johannes; Mostad, Petter

    2017-07-17

    Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for analysis are using a standard short tandem repeat (STR) DNA analysis assay, using the standard assay and a complementary assay, or the analysis may be cancelled following quantification. The decision is based on information about the DNA amount and level of DNA degradation of the forensic sample, as well as case circumstances and the cost for analysis. Semi-continuous electropherogram models are used for simulation of DNA profiles and for computation of likelihood ratios. It is shown how tables and graphs, prepared beforehand, can be used to quickly find the optimal decision in forensic casework.

  16. Notes on interval estimation of the gamma correlation under stratified random sampling.

    Science.gov (United States)

    Lui, Kung-Jong; Chang, Kuang-Chao

    2012-07-01

    We have developed four asymptotic interval estimators in closed forms for the gamma correlation under stratified random sampling, including the confidence interval based on the most commonly used weighted-least-squares (WLS) approach (CIWLS), the confidence interval calculated from the Mantel-Haenszel (MH) type estimator with the Fisher-type transformation (CIMHT), the confidence interval using the fundamental idea of Fieller's Theorem (CIFT) and the confidence interval derived from a monotonic function of the WLS estimator of Agresti's α with the logarithmic transformation (MWLSLR). To evaluate the finite-sample performance of these four interval estimators and note the possible loss of accuracy in application of both Wald's confidence interval and MWLSLR using pooled data without accounting for stratification, we employ Monte Carlo simulation. We use the data taken from a general social survey studying the association between the income level and job satisfaction with strata formed by genders in black Americans published elsewhere to illustrate the practical use of these interval estimators. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Predictive value of testing random urine sample to detect microalbuminuria in diabetic subjects during outpatient visit.

    Science.gov (United States)

    Bouhanick, B; Berrut, G; Chameau, A M; Hallar, M; Bled, F; Chevet, B; Vergely, J; Rohmer, V; Fressinaud, P; Marre, M

    1992-01-01

    The predictive value of random urine sample during outpatient visit to predict persistent microalbuminuria was studied in 76 Type 1, insulin-dependent diabetic subjects, 61 Type 2, non-insulin-dependent diabetic subjects, and 72 Type 2, insulin-treated diabetic subjects. Seventy-six patients attended outpatient clinic during morning, and 133 during afternoon. Microalbuminuria was suspected if Urinary Albumin Excretion (UAE) exceeded 20 mg/l. All patients were hospitalized within 6 months following outpatient visit, and persistent microalbuminuria was assessed then if UAE was between 30 and 300 mg/24 h on 2-3 occasions in 3 urines samples. Of these 209 subjects eighty-three were also screened with Microbumintest (Ames-Bayer), a semi-quantitative method. Among the 209 subjects, 71 were positive both for microalbuminuria during outpatient visit and a persistent microalbuminuria during hospitalization: sensitivity 91.0%, specificity 83.2%, concordance 86.1%, and positive predictive value 76.3% (chi-squared test: 191; p less than 10(-4)). Data were not different for subjects examined on morning, or on afternoon. Among the 83 subjects also screened with Microbumintest, 22 displayed both a positive reaction and a persistent microalbuminuria: sensitivity 76%, specificity 81%, concordance 80%, and positive predictive value 69% (chi-squared test: 126; p less than 10(-4)). Both types of screening appeared equally effective during outpatient visit. Hence, a persistent microalbuminuria can be predicted during an outpatient visit in a diabetic clinic.

  18. Effectiveness of hand hygiene education among a random sample of women from the community.

    Science.gov (United States)

    Ubheeram, J; Biranjia-Hurdoyal, S D

    2017-03-01

    The effectiveness of hand hygiene education was investigated by studying the hand hygiene awareness and bacterial hand contamination among a random sample of 170 women in the community. Questionnaire was used to assess the hand hygiene awareness score, followed by swabbing of the dominant hand. Bacterial identification was done by conventional biochemical tests. Better hand hygiene awareness score was significantly associated with age, scarce bacterial growth and absence of potential pathogen (p hand samples, bacterial growth was noted in 155 (91.2%), which included 91 (53.5%) heavy growth, 53 (31.2%) moderate growth and 11 (6.47%) scanty growth. The presence of enteric bacteria was associated with long nails (49.4% vs 29.2%; p = 0.007; OR = 2.3; 95% CI: 1.25-4.44) while finger rings were associated with higher bacterial load (p = 0.003). Coliforms was significantly higher among women who had a lower hand hygiene awareness score, washed their hands at lower frequency (59.0% vs 32.8%; p = 0.003; OR = 2.9; 95% CI: 1.41-6.13) and used common soap as compared to antiseptic soaps (69.7% vs 30.3%, p = 0.000; OR = 4.11; 95% CI: 1.67-10.12). Level of hand hygiene awareness among the participants was satisfactory but not the compliance of hand washing practice, especially among the elders.

  19. Association between stalking victimisation and psychiatric morbidity in a random community sample.

    Science.gov (United States)

    Purcell, Rosemary; Pathé, Michele; Mullen, Paul E

    2005-11-01

    No studies have assessed psychopathology among victims of stalking who have not sought specialist help. To examine the associations between stalking victimisation and psychiatric morbidity in a representative community sample. A random community sample (n=1844) completed surveys examining the experience of harassment and current mental health. The 28-item General Health Questionnaire (GHQ-28) and the Impact of Event Scale were used to assess symptomatology in those reporting brief harassment (n=196) or protracted stalking (n=236) and a matched control group reporting no harassment (n=432). Rates of caseness on the GHQ-28 were higher among stalking victims (36.4%) than among controls (19.3%) and victims of brief harassment (21.9%). Psychiatric morbidity did not differ according to the recency of victimisation, with 34.1% of victims meeting caseness criteria 1 year after stalking had ended. In a significant minority of victims, stalking victimisation is associated with psychiatric morbidity that may persist long after it has ceased. Recognition of the immediate and long-term impacts of stalking is necessary to assist victims and help alleviate distress and long-term disability.

  20. Forensic analysis of Salvia divinorum using multivariate statistical procedures. Part II: association of adulterated samples to S. divinorum.

    Science.gov (United States)

    Willard, Melissa A Bodnar; McGuffin, Victoria L; Smith, Ruth Waddell

    2012-01-01

    Salvia divinorum is a plant material that is of forensic interest due to the hallucinogenic nature of the active ingredient, salvinorin A. In this study, S. divinorum was extracted and spiked onto four different plant materials (S. divinorum, Salvia officinalis, Cannabis sativa, and Nicotiana tabacum) to simulate an adulterated sample that might be encountered in a forensic laboratory. The adulterated samples were extracted and analyzed by gas chromatography-mass spectrometry, and the resulting total ion chromatograms were subjected to a series of pretreatment procedures that were used to minimize non-chemical sources of variance in the data set. The data were then analyzed using principal components analysis (PCA) to investigate association of the adulterated extracts to unadulterated S. divinorum. While association was possible based on visual assessment of the PCA scores plot, additional procedures including Euclidean distance measurement, hierarchical cluster analysis, Student's t tests, Wilcoxon rank-sum tests, and Pearson product moment correlation were also applied to the PCA scores to provide a statistical evaluation of the association observed. The advantages and limitations of each statistical procedure in a forensic context were compared and are presented herein.

  1. Comparative analysis of EV isolation procedures for miRNAs detection in serum samples

    Directory of Open Access Journals (Sweden)

    Zoraida Andreu

    2016-06-01

    Full Text Available Extracellular vesicles (EVs are emerging as potent non-invasive biomarkers. However, current methodologies are time consuming and difficult to translate to clinical practice. To analyse EV-encapsulated circulating miRNA, we searched for a quick, easy and economic method to enrich frozen human serum samples for EV. We compared the efficiency of several protocols and commercial kits to isolate EVs. Different methods based on precipitation, columns or filter systems were tested and compared with ultracentrifugation, which is the most classical protocol to isolate EVs. EV samples were assessed for purity and quantity by nanoparticle tracking analysis and western blot or cytometry against major EV protein markers. For biomarker validation, levels of a set of miRNAs were determined in EV fractions and compared with their levels in total serum. EVs isolated with precipitation-based methods were enriched for a subgroup of miRNAs that corresponded to miRNAs described to be encapsulated into EVs (miR-126, miR-30c and miR-143, while the detection of miR-21, miR-16-5p and miR-19a was very low compared with total serum. Our results point to precipitation using polyethylene glycol (PEG as a suitable method for an easy and cheap enrichment of serum EVs for miRNA analyses. The overall performance of PEG was very similar, or better than other commercial precipitating reagents, in both protein and miRNA yield, but in comparison to them PEG is much cheaper. Other methods presented poorer results, mostly when assessing miRNA by qPCR analyses. Using PEG precipitation in a longitudinal study with human samples, we demonstrated that miRNA could be assessed in frozen samples up to 8 years of storage. We report a method based on a cut-off value of mean of fold EV detection versus serum that provides an estimate of the degree of encapsulation of a given miRNA.

  2. Application of solid phase extraction procedures for rare earth elements determination in environmental samples.

    Science.gov (United States)

    Pyrzynska, Krystyna; Kubiak, Anna; Wysocka, Irena

    2016-07-01

    Determination of rare earth elements in environmental samples requires often pre-concentration and separation step due to a low metal content and high concentration of the interfering matrix components. A solid phase extraction technique with different kind of solid sorbents offers a high enrichment factor, rapid phase separation and the possibility of its combination with various detection techniques used either in on-line or off-line mode. The recent developments in this area published over the last five years are presented and discussed in this paper. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Random sample community-based health surveys: does the effort to reach participants matter?

    Science.gov (United States)

    Messiah, Antoine; Castro, Grettel; Rodríguez de la Vega, Pura; Acuna, Juan M

    2014-12-15

    Conducting health surveys with community-based random samples are essential to capture an otherwise unreachable population, but these surveys can be biased if the effort to reach participants is insufficient. This study determines the desirable amount of effort to minimise such bias. A household-based health survey with random sampling and face-to-face interviews. Up to 11 visits, organised by canvassing rounds, were made to obtain an interview. Single-family homes in an underserved and understudied population in North Miami-Dade County, Florida, USA. Of a probabilistic sample of 2200 household addresses, 30 corresponded to empty lots, 74 were abandoned houses, 625 households declined to participate and 265 could not be reached and interviewed within 11 attempts. Analyses were performed on the 1206 remaining households. Each household was asked if any of their members had been told by a doctor that they had high blood pressure, heart disease including heart attack, cancer, diabetes, anxiety/ depression, obesity or asthma. Responses to these questions were analysed by the number of visit attempts needed to obtain the interview. Return per visit fell below 10% after four attempts, below 5% after six attempts and below 2% after eight attempts. As the effort increased, household size decreased, while household income and the percentage of interviewees active and employed increased; proportion of the seven health conditions decreased, four of which did so significantly: heart disease 20.4-9.2%, high blood pressure 63.5-58.1%, anxiety/depression 24.4-9.2% and obesity 21.8-12.6%. Beyond the fifth attempt, however, cumulative percentages varied by less than 1% and precision varied by less than 0.1%. In spite of the early and steep drop, sustaining at least five attempts to reach participants is necessary to reduce selection bias. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

  4. Acute changes of hip joint range of motion using selected clinical stretching procedures: A randomized crossover study.

    Science.gov (United States)

    Hammer, Adam M; Hammer, Roger L; Lomond, Karen V; O'Connor, Paul

    2017-09-01

    Hip adductor flexibility and strength is an important component of athletic performance and many activities of daily living. Little research has been done on the acute effects of a single session of stretching on hip abduction range of motion (ROM). The aim of this study was to compare 3 clinical stretching procedures against passive static stretching and control on ROM and peak isometric maximal voluntary contraction (MVC). Using a randomized crossover study design, a total of 40 participants (20 male and 20 female) who had reduced hip adductor muscle length attended a familiarization session and 5 testing sessions on non-consecutive days. Following the warm-up and pre-intervention measures of ROM and MVC, participants were randomly assigned 1 of 3 clinical stretching procedures (modified lunge, multidirectional, and joint mobilization) or a static stretch or control condition. Post-intervention measures of ROM and MVC were taken immediately following completion of the assigned condition. An ANOVA using a repeated measure design with the change score was conducted. All interventions resulted in small but statistically significant (p stretching was greater than control (p = 0.031). These data suggest that a single session of stretching has only a minimal effect on acute changes of hip abduction ROM. Although hip abduction is a frontal plane motion, to effectively increase the extensibility of the structures that limit abduction, integrating multi-planar stretches may be indicated. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Oral analgesia vs intravenous conscious sedation during Essure Micro-Insert sterilization procedure: randomized, double-blind, controlled trial.

    Science.gov (United States)

    Thiel, John A; Lukwinski, Angelina; Kamencic, Huse; Lim, Hyung

    2011-01-01

    To compare the pain reported by patients during the Essure Micro-Insert sterilization procedure using either intravenous conscious sedation or oral analgesia. Randomized, double-blind, placebo-controlled trial (Canadian Task Force classification I). Tertiary care ambulatory women's clinic. Eighty women of reproductive age women requesting permanent sterilization. Hysteroscopic placement of the Essure Micro-Insert permanent birth control system. Patients undergoing placement of the Essure Micro-Insert system for permanent contraception were randomized to receive either intravenous conscious sedation, oral analgesia, or placebo. During the procedure, pain scores were recorded using a visual analog scale. Patients in the oral analgesia group reported slightly more pain during insertion of the hysteroscope and placement of the second micro-insert; the groups were otherwise equivalent. They were also equivalent when all visual analog scale scores were combined. Oral analgesia is an effective method of pain control during placement of the Essure Micro-Insert permanent birth control system. Copyright © 2011 AAGL. Published by Elsevier Inc. All rights reserved.

  6. A Discussion of Procedures and Equipment for the Comprehensive Test Ban Treaty On-Site Inspection Environmental Sampling and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wogman, Ned A.; Milbrath, Brian D.; Payne, Rosara F.; Seifert, Carolyn E.; Friese, Judah I.; Miley, Harry S.; Bowyer, Ted W.; Hanlen, Richard C.; Onishi, Yasuo; Hayes, James C.; Wigmosta, Mark S.

    2011-02-01

    This paper is intended to serve as a scientific basis to start discussions of the available environmental sampling techniques and equipment that have been used in the past that could be considered for use within the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on-site inspections (OSI). This work contains information on the techniques, equipment, costs, and some operational procedures associated with environmental sampling that have actually been used in the past by the United States for the detection of nuclear explosions. This paper also includes a discussion of issues, recommendations, and questions needing further study within the context of the sampling and analysis of aquatic materials, atmospheric gases, atmospheric particulates, vegetation, sediments and soils, fauna, and drill-back materials.

  7. Therapeutic touch is not therapeutic for procedural pain in very preterm neonates: a randomized trial.

    Science.gov (United States)

    Johnston, Celeste; Campbell-Yeo, Marsha; Rich, Bonnie; Whitley, Julie; Filion, Francoise; Cogan, Jennifer; Walker, Claire-Dominique

    2013-09-01

    Preterm neonates below 30 weeks' gestational age undergo numerous painful procedures. Many management approaches are not appropriate for this population. Therapeutic Touch, an alternative approach based on the theory of energy medicine, has been shown to promote physiological stability in preterm neonates and reduce pain in some adult studies. The objective was to determine whether Therapeutic Touch is efficacious in decreasing pain in preterm neonates. Infants Touch (n = 27) with infant behind curtains, leaving the curtained area for the heel lance, performed by another. In the sham condition (n = 28), the therapist stood by the incubator with hands by her side. The Premature Infant Pain Profile was used for pain response and time for heart rate to return to baseline for recovery. Heart rate variability and stress response were secondary outcomes. There were no group differences in any of the outcomes. Mean Premature Infant Pain Profile scores across 2 minutes of heel lance procedure in 30-second blocks ranged from 7.92 to 8.98 in the Therapeutic Touch group and 7.64 to 8.46 in the sham group. Therapeutic Touch given immediately before and after heel lance has no comforting effect in preterm neonates. Other effective strategies involving actual touch should be considered.

  8. Sample treatment procedures for the determination of mineral constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Mendes Teresa M. F. F.

    2006-01-01

    Full Text Available Preparative methods for quantification of inorganic constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES using microwave assisted digestion and ultrasonication procedures were developed. Analytical aspects such as matrix complexity, instrumental optimization and the essentiality/toxicity of the species K, Ca, Mg, Na, Fe, Mn, Zn, Cu, Co, Ni, Pb, Cd were considered. Parameters such as plasma power, nebulizer flow rate, torch configuration and the convenience of the use of yttrium as internal standard were evaluated. Recoveries between 93 and 107% (microwave digestion and between 90 to 110% (ultrasonication procedure and relative standard deviations lower than 10% were obtained. Samples of Brazilian honeys, from different parts of the country, were analysed and the results obtained provide relevant information about their mineral content.

  9. New procedure for recovering extra- and intracellular DNA from marine sediment samples

    Science.gov (United States)

    Alawi, M.; Kallmeyer, J.

    2012-12-01

    Extracellular DNA (eDNA) is a ubiquitous biological compound in aquatic sediment and soil. Despite major methodological advances, analysis of DNA from sediment is still technically challenging, not just because of the co-elution of inhibitory substances, but also due to co-elution of extracellular DNA, which potentially leads to an overestimate of the actual diversity. Previous studies suggested that eDNA might play an important role in biogeochemical element cycling, horizontal gene transfer and stabilization of biofilm structures. Several protocols based on the precipitation of eDNA e.g. with CTAB and ethanol have already been published. However, using these methods we did not succeed in quantifying very low amounts of eDNA (e.g. applications like PCR can be performed. To evaluate the new extraction method two sediments with rather opposing composition were analyzed. Sediment from the South Pacific Gyre, the most oligotrophic oceanic region on earth and organic-rich Baltic Sea sediment (Northern Germany) were processed. Using this new procedure high purity genomic iDNA and eDNA with a molecular size range between 20 bp and 50k bp can be simultaneously recovered even from very oligotrophic sediment with very low cell abundances. The main fraction of recovered eDNA was suitable for downstream applications like PCR and had a molecular size that indicates minimal shearing. Despite about two decades of research many questions about deep subsurface life remain unanswered. The fact that microbes can be found even in deep oligotrophic marine sediment raises the fundamental questions of the types and availability of substrates and their biogeochemical cycling. This is the first study that provides evidence that eDNA is an important potential substrate for microorganisms in the deep biosphere. Also, our results show a link between cell counts and eDNA content, indicating that the eDNA pool in the investigated sediment consist mainly of microbial DNA. Comparative sequence

  10. A Loop-Mediated Isothermal Amplification Assay and Sample Preparation Procedure for Sensitive Detection of Xanthomonas fragariae in Strawberry

    Science.gov (United States)

    Wang, Hehe; Turechek, William W.

    2016-01-01

    Xanthomonas fragariae is a bacterium that causes angular leaf spot of strawberry. Asymptomatic infection is common and contributes to the difficulties in disease management. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) assay as an efficient method for detection of asymptomatic infections of X. fragariae. In addition, a new method of sample preparation was developed that allows sampling of a larger amount of plant tissue, hence increasing the detection rate in real-life samples. The sample preparation procedure includes an overnight incubation of strawberry tissues in phosphate-buffered saline (PBS), followed by a quick sample concentration and a boiling step to extract DNA for amplification. The detection limit of the LAMP assay was approximately 2×103 CFU/mL for pure bacteria culture and 300 CFU/mL for bacteria spiked strawberry leaf and petiole samples. LAMP provided a 2–3 fold lower detection limit than the standard qPCR assay but was faster, and more user-friendly. The LAMP assay should serve as a rapid, sensitive and cost-effective tool for detecting asymptomatic infections of X. fragariae in strawberry nursery stock and contribute to improved disease management. PMID:26766068

  11. A Procedure to Determine the Optimal Sensor Positions for Locating AE Sources in Rock Samples

    Science.gov (United States)

    Duca, S.; Occhiena, C.; Sambuelli, L.

    2015-03-01

    Within a research work aimed to better understand frost weathering mechanisms of rocks, laboratory tests have been designed to specifically assess a theoretical model of crack propagation due to ice segregation process in water-saturated and thermally microcracked cubic samples of Arolla gneiss. As the formation and growth of microcracks during freezing tests on rock material is accompanied by a sudden release of stored elastic energy, the propagation of elastic waves can be detected, at the laboratory scale, by acoustic emission (AE) sensors. The AE receiver array geometry is a sensitive factor influencing source location errors, for it can greatly amplify the effect of small measurement errors. Despite the large literature on the AE source location, little attention, to our knowledge, has been paid to the description of the experimental design phase. As a consequence, the criteria for sensor positioning are often not declared and not related to location accuracy. In the present paper, a tool for the identification of the optimal sensor position on a cubic shape rock specimen is presented. The optimal receiver configuration is chosen by studying the condition numbers of each of the kernel matrices, used for inverting the arrival time and finding the source location, and obtained for properly selected combinations between sensors and sources positions.

  12. Sample-to-sample fluctuations of power spectrum of a random motion in a periodic Sinai model

    Science.gov (United States)

    Dean, David S.; Iorio, Antonio; Marinari, Enzo; Oshanin, Gleb

    2016-09-01

    The Sinai model of a tracer diffusing in a quenched Brownian potential is a much-studied problem exhibiting a logarithmically slow anomalous diffusion due to the growth of energy barriers with the system size. However, if the potential is random but periodic, the regime of anomalous diffusion crosses over to one of normal diffusion once a tracer has diffused over a few periods of the system. Here we consider a system in which the potential is given by a Brownian bridge on a finite interval (0 ,L ) and then periodically repeated over the whole real line and study the power spectrum S (f ) of the diffusive process x (t ) in such a potential. We show that for most of realizations of x (t ) in a given realization of the potential, the low-frequency behavior is S (f ) ˜A /f2 , i.e., the same as for standard Brownian motion, and the amplitude A is a disorder-dependent random variable with a finite support. Focusing on the statistical properties of this random variable, we determine the moments of A of arbitrary, negative, or positive order k and demonstrate that they exhibit a multifractal dependence on k and a rather unusual dependence on the temperature and on the periodicity L , which are supported by atypical realizations of the periodic disorder. We finally show that the distribution of A has a log-normal left tail and exhibits an essential singularity close to the right edge of the support, which is related to the Lifshitz singularity. Our findings are based both on analytic results and on extensive numerical simulations of the process x (t ) .

  13. Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

    Science.gov (United States)

    Roque, Inês; Lourenço, Rui; Marques, Ana; Coelho, João Pedro; Coelho, Cláudia; Pereira, Eduarda; Rabaça, João E; Roulin, Alexandre

    2016-04-01

    Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios.

  14. Effects of estrogen plus progestin on gynecologic cancers and associated diagnostic procedures: the Women's Health Initiative randomized trial.

    Science.gov (United States)

    Anderson, Garnet L; Judd, Howard L; Kaunitz, Andrew M; Barad, David H; Beresford, Shirley A A; Pettinger, Mary; Liu, James; McNeeley, S Gene; Lopez, Ana Maria

    2003-10-01

    The effects of continuous combined hormone therapy on gynecologic cancers have not been investigated previously in a randomized trial setting. To determine the possible associations of estrogen plus progestin on gynecologic cancers and related diagnostic procedures. Randomized, double-blind, placebo-controlled trial of 16 608 postmenopausal women, who had not had a hysterectomy at baseline and who had been recruited from 40 US clinical centers between September 1993 and October 1998 (average follow-up, 5.6 years). One tablet per day containing 0.625 mg of conjugated equine estrogens plus 2.5 mg of medroxyprogesterone acetate (n = 8506) or placebo (n = 8102). Incident invasive cancer of the ovary and endometrium. In 5.6 years of follow-up, there were 32 cases of invasive ovarian cancer, 58 cases of endometrial cancer, 1 case of nonendometrial uterine cancer, 13 cases of cervical cancer, and 7 cases of other gynecologic cancers. The hazard ratio (HR) for invasive ovarian cancer in women assigned to estrogen plus progestin compared with placebo was 1.58 (95% confidence interval [CI], 0.77-3.24). The HR for endometrial cancer was 0.81 (95% CI, 0.48-1.36). No appreciable differences were found in the distributions of tumor histology, stage, or grade for either cancer site. The incidence of other gynecologic cancers was low and did not differ by randomization assignment. More women taking estrogen plus progestin required endometrial biopsies (33% vs 6%; P<.001). This randomized trial suggests that continuous combined estrogen plus progestin therapy may increase the risk of ovarian cancer while producing endometrial cancer rates similar to placebo. The increased burden of endometrial biopsies required to assess vaginal bleeding further limits the acceptability of this regimen. These data provide additional support for caution in the use of continuous combined hormones.

  15. Missing citations due to exact reference matching: Analysis of a random sample from WoS. Are publications from peripheral countries disadvantaged?

    Energy Technology Data Exchange (ETDEWEB)

    Donner, P.

    2016-07-01

    Citation counts of scientific research contributions are one fundamental data in scientometrics. Accuracy and completeness of citation links are therefore crucial data quality issues (Moed, 2005, Ch. 13). However, despite the known flaws of reference matching algorithms, usually no attempts are made to incorporate uncertainty about citation counts into indicators. This study is a step towards that goal. Particular attention is paid to the question whether publications from countries not using basic Latin script are differently affected by missed citations. The proprietary reference matching procedure of Web of Science (WoS) is based on (near) exact agreement of cited reference data (normalized during processing) to the target papers bibliographical data. Consequently, the procedure has near-optimal precision but incomplete recall - it is known to miss some slightly inaccurate reference links (Olensky, 2015). However, there has been no attempt so far to estimate the rate of missed citations by a principled method for a random sample. For this study a simple random sample of WoS source papers was drawn and it was attempted to find all reference strings of WoS indexed documents that refer to them, in particular inexact matches. The objective is to give a statistical estimate of the proportion of missed citations and to describe the relationship of the number of found citations to the number of missed citations, i.e. the conditional error distribution. The empirical error distribution is statistically analyzed and modelled. (Author)

  16. Random Model Sampling: Making Craig Interpolation Work When It Should Not

    Directory of Open Access Journals (Sweden)

    Marat Akhin

    2014-01-01

    Full Text Available One of the most serious problems when doing program analyses is dealing with function calls. While function inlining is the traditional approach to this problem, it nonetheless suffers from the increase in analysis complexity due to the state space explosion. Craig interpolation has been successfully used in recent years in the context of bounded model checking to do function summarization which allows one to replace the complete function body with its succinct summary and, therefore, reduce the complexity. Unfortunately this technique can be applied only to a pair of unsatisfiable formulae.In this work-in-progress paper we present an approach to function summarization based on Craig interpolation that overcomes its limitation by using random model sampling. It captures interesting input/output relations, strengthening satisfiable formulae into unsatisfiable ones and thus allowing the use of Craig interpolation. Preliminary experiments show the applicability of this approach; in our future work we plan to do a full evaluation on real-world examples.

  17. Discriminative motif discovery via simulated evolution and random under-sampling.

    Directory of Open Access Journals (Sweden)

    Tao Song

    Full Text Available Conserved motifs in biological sequences are closely related to their structure and functions. Recently, discriminative motif discovery methods have attracted more and more attention. However, little attention has been devoted to the data imbalance problem, which is one of the main reasons affecting the performance of the discriminative models. In this article, a simulated evolution method is applied to solve the multi-class imbalance problem at the stage of data preprocessing, and at the stage of Hidden Markov Models (HMMs training, a random under-sampling method is introduced for the imbalance between the positive and negative datasets. It is shown that, in the task of discovering targeting motifs of nine subcellular compartments, the motifs found by our method are more conserved than the methods without considering data imbalance problem and recover the most known targeting motifs from Minimotif Miner and InterPro. Meanwhile, we use the found motifs to predict protein subcellular localization and achieve higher prediction precision and recall for the minority classes.

  18. Neurofeedback Against Binge Eating: A Randomized Controlled Trial in a Female Subclinical Threshold Sample.

    Science.gov (United States)

    Schmidt, Jennifer; Martin, Alexandra

    2016-09-01

    Brain-directed treatment techniques, such as neurofeedback, have recently been proposed as adjuncts in the treatment of eating disorders to improve therapeutic outcomes. In line with this recommendation, a cue exposure EEG-neurofeedback protocol was developed. The present study aimed at the evaluation of the specific efficacy of neurofeedback to reduce subjective binge eating in a female subthreshold sample. A total of 75 subjects were randomized to EEG-neurofeedback, mental imagery with a comparable treatment set-up or a waitlist group. At post-treatment, only EEG-neurofeedback led to a reduced frequency of binge eating (p = .015, g = 0.65). The effects remained stable to a 3-month follow-up. EEG-neurofeedback further showed particular beneficial effects on perceived stress and dietary self-efficacy. Differences in outcomes did not arise from divergent treatment expectations. Because EEG-neurofeedback showed a specific efficacy, it may be a promising brain-directed approach that should be tested as a treatment adjunct in clinical groups with binge eating. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association. Copyright © 2016 John Wiley & Sons, Ltd and Eating Disorders Association.

  19. A coupled well-balanced and random sampling scheme for computing bubble oscillations*

    Directory of Open Access Journals (Sweden)

    Jung Jonathan

    2012-04-01

    Full Text Available We propose a finite volume scheme to study the oscillations of a spherical bubble of gas in a liquid phase. Spherical symmetry implies a geometric source term in the Euler equations. Our scheme satisfies the well-balanced property. It is based on the VFRoe approach. In order to avoid spurious pressure oscillations, the well-balanced approach is coupled with an ALE (Arbitrary Lagrangian Eulerian technique at the interface and a random sampling remap. Nous proposons un schéma de volumes finis pour étudier les oscillations d’une bulle sphérique de gaz dans l’eau. La symétrie sphérique fait apparaitre un terme source géométrique dans les équations d’Euler. Notre schéma est basé sur une approche VFRoe et préserve les états stationnaires. Pour éviter les oscillations de pression, l’approche well-balanced est couplée avec une approche ALE (Arbitrary Lagrangian Eulerian, et une étape de projection basée sur un échantillonage aléatoire.

  20. Accelerating Markov chain Monte Carlo simulation by differential evolution with self-adaptive randomized subspace sampling

    Energy Technology Data Exchange (ETDEWEB)

    Vrugt, Jasper A [Los Alamos National Laboratory; Hyman, James M [Los Alamos National Laboratory; Robinson, Bruce A [Los Alamos National Laboratory; Higdon, Dave [Los Alamos National Laboratory; Ter Braak, Cajo J F [NETHERLANDS; Diks, Cees G H [UNIV OF AMSTERDAM

    2008-01-01

    Markov chain Monte Carlo (MCMC) methods have found widespread use in many fields of study to estimate the average properties of complex systems, and for posterior inference in a Bayesian framework. Existing theory and experiments prove convergence of well constructed MCMC schemes to the appropriate limiting distribution under a variety of different conditions. In practice, however this convergence is often observed to be disturbingly slow. This is frequently caused by an inappropriate selection of the proposal distribution used to generate trial moves in the Markov Chain. Here we show that significant improvements to the efficiency of MCMC simulation can be made by using a self-adaptive Differential Evolution learning strategy within a population-based evolutionary framework. This scheme, entitled DiffeRential Evolution Adaptive Metropolis or DREAM, runs multiple different chains simultaneously for global exploration, and automatically tunes the scale and orientation of the proposal distribution in randomized subspaces during the search. Ergodicity of the algorithm is proved, and various examples involving nonlinearity, high-dimensionality, and multimodality show that DREAM is generally superior to other adaptive MCMC sampling approaches. The DREAM scheme significantly enhances the applicability of MCMC simulation to complex, multi-modal search problems.

  1. Sample preparation and data interpretation procedures for the examination of xenobiotic compounds in skin by indirect imaging MALDI-MS

    Science.gov (United States)

    Prideaux, Brendan; Atkinson, Sally J.; Carolan, Vikki A.; Morton, Jacqueline; Clench, Malcolm R.

    2007-02-01

    Aspects of the indirect examination of xenobiotic distribution on the surface of and within skin sections by imaging matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) have been examined. A solvent assisted blotting technique previously developed for the examination of the absorption of agrochemicals into leaves has been examined for the analysis of the distribution of hydrocortisone on the surface of skin. It was found that by careful control of the extraction and blotting procedure an 80-fold sensitivity improvement could by obtained over dry blotting with only 10% lateral diffusion of the image. However, in contrast it was found that the use of a hydrophobic blotting membrane was more suitable for the examination of the transdermal absorption of the pesticide chlorpyrifos. The potential of incorporating a derivatisation step into the solvent assisted blotting procedure was investigated by blotting isocyanate treated skin onto a methanol soaked blotting membrane. This served the dual purpose of derivatising the isocyanate to a stable substituted urea derivative and extracting it from the skin. Preliminary data indicate that this approach may have some merit for field sampling for such compound and clearly derivatisation also offers the potential for sensitivity enhancements. Finally, the use of principal components analysis with an ion species specific normalisation procedure is proposed to identify regions of drug treated skin where the ion abundance of the compound of interest is low.

  2. Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations.

    Science.gov (United States)

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2017-08-01

    Cluster-level dynamic treatment regimens can be used to guide sequential treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level dynamic treatment regimen, the treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including aggregate measures of the individuals or patients that compose it. Cluster-randomized sequential multiple assignment randomized trials can be used to answer multiple open questions preventing scientists from developing high-quality cluster-level dynamic treatment regimens. In a cluster-randomized sequential multiple assignment randomized trial, sequential randomizations occur at the cluster level and outcomes are observed at the individual level. This manuscript makes two contributions to the design and analysis of cluster-randomized sequential multiple assignment randomized trials. First, a weighted least squares regression approach is proposed for comparing the mean of a patient-level outcome between the cluster-level dynamic treatment regimens embedded in a sequential multiple assignment randomized trial. The regression approach facilitates the use of baseline covariates which is often critical in the analysis of cluster-level trials. Second, sample size calculators are derived for two common cluster-randomized sequential multiple assignment randomized trial designs for use when the primary aim is a between-dynamic treatment regimen comparison of the mean of a continuous patient-level outcome. The methods are motivated by the Adaptive Implementation of Effective Programs Trial which is, to our knowledge, the first-ever cluster-randomized sequential multiple assignment randomized trial in psychiatry.

  3. Early Aqueous Suppressant Therapy on Hypertensive Phase Following Glaucoma Drainage Device Procedure: A Randomized Prospective Trial.

    Science.gov (United States)

    Law, Simon K; Kornmann, Helen L; Giaconi, JoAnn A; Kwong, Allen; Tran, Eric; Caprioli, Joseph

    2016-03-01

    To prospectively evaluate the effect of early aqueous suppression (therapy) on hypertensive phase (HP) and intraocular pressure (IOP) control after implantation of silicone Ahmed glaucoma valve (AGV). Patients who underwent AGV implantation were randomized to initiate therapy (including β-blockers, α-agonists, or carbonic anhydrase inhibitors) when postoperative IOP>10 mm Hg (low-IOP initiation group) or >17 mm Hg (moderate-IOP initiation group). HP was defined as an IOP>21 mm Hg during the first 6 postoperative months, after an initial IOP reduction to measures included the occurrence of HP and IOP control. Fifty-two eyes (50 patients) underwent AGV implantation. Average follow-up was 21.9±10.7 months. HP was observed in 21 eyes (40.4%) with average peak IOP of 30±8 mm Hg, onset at 32±30 days, and duration of 15±32 days. One year postoperatively, those eyes with HP had higher IOP than eyes that did not develop HP (15.1±5.2, 11.4±4.3, respectively; P=0.021) and required more additional glaucoma surgeries (28.6%, 3.2%, respectively; P=0.013). The peak IOP at week 3 postoperatively in the low-IOP initiation group (26 eyes) was significantly lower than in the moderate-IOP initiation group (26 eyes; 15.7±3.6, 20.6±8.9, respectively; P=0.012). Eyes with therapy started after HP onset had significantly higher postoperative IOP from 2 to 4 months. Therapy initiated before the development of HP was not associated with a higher complication rate. Aqueous suppression initiated in the early postoperative period while IOPs were still in the low-teens and was able to reduce the incidence of IOP spike associated with the HP without an increased complication rate.

  4. Optimized pre-thinning procedures of ion-beam thinning for TEM sample preparation by magnetorheological polishing.

    Science.gov (United States)

    Luo, Hu; Yin, Shaohui; Zhang, Guanhua; Liu, Chunhui; Tang, Qingchun; Guo, Meijian

    2017-10-01

    Ion-beam-thinning is a well-established sample preparation technique for transmission electron microscopy (TEM), but tedious procedures and labor consuming pre-thinning could seriously reduce its efficiency. In this work, we present a simple pre-thinning technique by using magnetorheological (MR) polishing to replace manual lapping and dimpling, and demonstrate the successful preparation of electron-transparent single crystal silicon samples after MR polishing and single-sided ion milling. Dimples pre-thinned to less than 30 microns and with little mechanical surface damage were repeatedly produced under optimized MR polishing conditions. Samples pre-thinned by both MR polishing and traditional technique were ion-beam thinned from the rear side until perforation, and then observed by optical microscopy and TEM. The results show that the specimen pre-thinned by MR technique was free from dimpling related defects, which were still residual in sample pre-thinned by conventional technique. Nice high-resolution TEM images could be acquired after MR polishing and one side ion-thinning. MR polishing promises to be an adaptable and efficient method for pre-thinning in preparation of TEM specimens, especially for brittle ceramics. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    Science.gov (United States)

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Determination of thiobencarb in water samples by gas chromatography using a homogeneous liquid-liquid microextraction via flotation assistance procedure

    Directory of Open Access Journals (Sweden)

    H.A. Mashayekhi

    2013-09-01

    Full Text Available Homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA coupled with gas chromatography-flame ionization detection (GC-FID was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added into the extraction cell which contained an appropriate mixture of toluene (as an extraction solvent and acetone (as a homogeneous solvent. By using air flotation, the organic solvent was collected at the conical part of the designed cell. The effect of the different parameters on the efficiency of extraction such as type and volume of extraction and homogeneous solvents, ionic strength and extraction time were studied and optimized. Under the optimal conditions, linearity of the method was in the range of 1.0-200 µg L-1. The relative standard deviations in the real samples varied from 7.8-11.7 % (n = 3. The proposed method was successfully applied to analysis of thiobencarb in the water samples and satisfactory results were obtained.DOI: http://dx.doi.org/10.4314/bcse.v27i3.4

  7. Prospective randomized controlled trial of an injectable esophageal prosthesis versus a sham procedure for endoscopic treatment of gastroesophageal reflux disease.

    Science.gov (United States)

    Fockens, Paul; Cohen, Lawrence; Edmundowicz, Steven A; Binmoeller, Kenneth; Rothstein, Richard I; Smith, Daniel; Lin, Edward; Nickl, Nicholas; Overholt, Bergein; Kahrilas, Peter J; Vakil, Nimish; Abdel Aziz Hassan, Ayman M; Lehman, Glen A

    2010-06-01

    This study aimed to assess whether endoscopic implantation of an injectable esophageal prosthesis, the Gatekeeper Reflux Repair System (GK), is a safe and effective therapy for controlling gastroesophageal reflux disease (GERD). A prospective, randomized, sham-controlled, single-blinded, international multicenter study planned final enrollment of 204 patients in three groups: up to 60 lead-in, 96 GK, and 48 sham patients. The sham patients were allowed to cross over to the GK treatment arm or exit the study at 6 months. The primary end points were (1) reduction in serious device- and procedure-related adverse device effects compared with a surgical composite complication rate and (2) reduction in heartburn symptoms 6 months after the GK procedure compared with the sham procedure. The secondary end point was improved esophageal pH (total time pH was <4) 6 months after the GK procedure compared with baseline. A planned interim analysis was performed after 143 patients were enrolled (25 lead-in, 75 GK, and 43 sham patients), and the GK study was terminated early due to lack of compelling efficacy data. Four reported serious adverse events had occurred (2 perforations, 1 pulmonary infiltrate related to a perforation, and 1 severe chest pain) at termination of the study with no mortality or long-term sequelae. Heartburn symptoms had improved significantly at 6 months compared with baseline in the GK group (p < 0.0001) and the sham group (p < 0.0001), but no significant between-group difference in improvement was observed (p = 0.146). Esophageal acid exposure had improved significantly at 6 months compared with baseline in the GK group (p = 0.021) and the sham group (p = 0.003), but no significant between-group difference in improvement was observed (p = 0.27). The GK procedure was associated with some serious but infrequent complications. No statistically significant difference in outcomes was observed between the treatment and control groups at 6 months compared with

  8. Comparison of amnion allograft with connective tissue graft for root coverage procedures: a double-blind, randomized, controlled clinical trial.

    Science.gov (United States)

    Ghahroudi, Amir Alireza Rasouli; Khorsand, Afshin; Rokn, Amir Reza; Sabounchi, Sepideh Seyedzadeh; Shayesteh, Yadollah Soleimani; Soolari, Ahmad

    2013-10-01

    The aim of the present double-blind, randomized, controlled study was to evaluate and compare the efficacy of amnion allograft and connective tissue graft in covering denuded root surfaces. Seventy-one teeth in 22 patients with gingival recession were treated randomly with coronally displaced flap plus connective tissue graft (control group, n = 29 recessions in 10 patients) or coronally displaced flap plus amnion allograft (test group, n = 42 recessions in 12 patients). The amount of root coverage and clinical parameters (probing depth, recession depth, clinical attachment level, recession width, gingival width, and papilla dimensions) were measured at baseline and at 3 and 6 months postoperatively. Average root coverage percentages after 6 months in the test and control groups were 67% (2.3 +/- 0.289 mm) and 54% (2.24 +/- 0.519 mm), respectively, with no statistically significant differences (p = 0.054). The changes in depth and width of recessions and in gingival width were significant 3 and 6 months after surgery compared to baseline (p = 0.000). Variations in the level of attachment and probing depths after 6 months were statistically significant in the test group compared to the control group (p = 0.002). Papilla dimensions were significantly correlated with root coverage (p = 0.00). Amnion allograft might be a suitable alternative to connective tissue graft in procedures to cover denuded root surfaces and can reduce recession depth.

  9. Oral Chloral Hydrate Compare with Rectal Thiopental in Pediatric Procedural Sedation and Analgesia; a Randomized Clinical Trial

    Directory of Open Access Journals (Sweden)

    Reza Azizkhani

    2014-03-01

    Full Text Available Introduction: The increasing use of diagnostic imaging in pediatric medicine has resulted in growing need for procedural sedation and analgesia (PSA to minimize motion artifacts during procedures. The drug of choice in pediatric PSA was not introduced till now. The aim of the present study was comparison of oral chloral hydrate (OCH and rectal sodium thiopental (RST in pediatric PSA.Methods: In the present randomized clinical trial, 2-6 years old pediatrics who referred for performing brain computed tomography scan was enrolled and were randomly divided in to two groups. OCH (50mg/kg and RST (25mg/kg were prescribed and a trained nurse recorded the time from drug prescription to receiving the conscious sedation (onset of action, the total time period which the patient has the Ramsay score≥4 (duration of action, and adverse effect of agents. Mann-Whitney U test and chi-squared test, and Non-parametric analysis of covariance (ANCOVA were used for comparisons. Results: One hundred and forty children were entered to two groups of OCH and RST, randomly. The patients of two groups had similar age, sex, weight, and baseline vital signs except for diastolic blood pressure (p<0.001. The onset of action in OCH and RST groups were 24.5±6.1and 28.7±5.2 minutes, respectively (p<0.001. Duration of action in OCH and RST groups were 12.9±2.8 minutes and 13.7±2.6 minutes, respectively (p=0.085. Non parametric ANCOVA revealed that only diastolic blood pressure was affected by drug prescription (p=0.001. In 11(15.7% patients in RST group, diarrhea was observed during 24 hours (p=0.001. Oxygen desaturation was observed only in two patients, both in OCH group. Conclusion: Each of the sedative has advantages and disadvantages that should be considered when selecting one for inducing short-term sedation. It seems that rectal sodium thiopental and oral chloral hydrate are equally effective in pediatric PSA and based on patient’s condition we can administrate

  10. Simplified matrix solid phase dispersion procedure for the determination of parabens and benzophenone-ultraviolet filters in human placental tissue samples.

    Science.gov (United States)

    Vela-Soria, F; Rodríguez, I; Ballesteros, O; Zafra-Gómez, A; Ballesteros, L; Cela, R; Navalón, A

    2014-12-05

    In recent decades, the industrial development has resulted in the appearance of a large amount of new chemicals that are able to produce disorders in the human endocrine system. These substances, so-called endocrine disrupting chemicals (EDCs), include many families of compounds, such as parabens and benzophenone-UV filters. Taking into account the demonstrated biological activity of these compounds, it is necessary to develop new analytical procedures to assess the exposure in order to establish, in an accurate way, relationships between EDCs and harmful health effects in population. In the present work, a new method based on a simplified sample treatment by matrix solid phase dispersion (MSPD) followed by ultrahigh performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis, is validated for the determination of four parabens (methyl-, ethyl-, propyl- and butylparaben) and six benzophenone-UV filters (benzophenone-1, benzophenone-2, benzophenone-3, benzophenone-6, benzophenone-8 and 4-hydroxybenzophenone) in human placental tissue samples. The extraction parameters were accurately optimized using multivariate optimization strategies. Ethylparaben ring-13C6 and benzophenone-d10 were used as surrogates. The found limits of quantification ranged from 0.2 to 0.4 ng g(-1) and inter-day variability (evaluated as relative standard deviation) ranged from 5.4% to 12.8%. The method was validated using matrix-matched standard calibration followed by a recovery assay with spiked samples. Recovery rates ranged from 96% to 104%. The method was satisfactorily applied for the determination of compounds in human placental tissue samples collected at the moment of delivery from 10 randomly selected women. Copyright © 2014 Elsevier B.V. All rights reserved.

  11. Hierarchical Structure of the Eysenck Personality Inventory in a Large Population Sample: Goldberg's Trait-Tier Mapping Procedure.

    Science.gov (United States)

    Chapman, Benjamin P; Weiss, Alexander; Barrett, Paul; Duberstein, Paul

    2013-03-01

    The structure of the Eysenck Personality Inventory (EPI) is poorly understood, and applications have mostly been confined to the broad Neuroticism, Extraversion, and Lie scales. Using a hierarchical factoring procedure, we mapped the sequential differentiation of EPI scales from broad, molar factors to more specific, molecular factors, in a UK population sample of over 6500 persons. Replicable facets at the lowest tier of Neuroticism included emotional fragility, mood lability, nervous tension, and rumination. The lowest order set of replicable Extraversion facets consisted of social dynamism, sociotropy, decisiveness, jocularity, social information seeking, and impulsivity. The Lie scale consisted of an interpersonal virtue and a behavioral diligence facet. Users of the EPI may be well served in some circumstances by considering its broad Neuroticism, Extraversion, and Lie scales as multifactorial, a feature that was explicitly incorporated into subsequent Eysenck inventories and is consistent with other hierarchical trait structures.

  12. Experiments with central-limit properties of spatial samples from locally covariant random fields

    Science.gov (United States)

    Barringer, T.H.; Smith, T.E.

    1992-01-01

    When spatial samples are statistically dependent, the classical estimator of sample-mean standard deviation is well known to be inconsistent. For locally dependent samples, however, consistent estimators of sample-mean standard deviation can be constructed. The present paper investigates the sampling properties of one such estimator, designated as the tau estimator of sample-mean standard deviation. In particular, the asymptotic normality properties of standardized sample means based on tau estimators are studied in terms of computer experiments with simulated sample-mean distributions. The effects of both sample size and dependency levels among samples are examined for various value of tau (denoting the size of the spatial kernel for the estimator). The results suggest that even for small degrees of spatial dependency, the tau estimator exhibits significantly stronger normality properties than does the classical estimator of standardized sample means. ?? 1992.

  13. LONG-TERM VARIABILITY OF BRONCHIAL RESPONSIVENESS TO HISTAMINE IN A RANDOM-POPULATION SAMPLE OF ADULTS

    NARCIS (Netherlands)

    RIJCKEN, B; SCHOUTEN, JP; WEISS, ST; ROSNER, B; DEVRIES, K; VANDERLENDE, R

    1993-01-01

    Long-term variability of bronchial responsiveness has been studied in a random population sample of adults. During a follow-up period of 18 yr, 2,216 subjects contributed 5,012 observations to the analyses. Each subject could have as many as seven observations. Bronchial responsiveness was assessed

  14. Recovery of extracellular vesicles from human breast milk is influenced by sample collection and vesicle isolation procedures

    Directory of Open Access Journals (Sweden)

    Marijke I. Zonneveld

    2014-08-01

    Full Text Available Extracellular vesicles (EV in breast milk carry immune relevant proteins and could play an important role in the instruction of the neonatal immune system. To further analyze these EV and to elucidate their function it is important that native populations of EV can be recovered from (stored breast milk samples in a reproducible fashion. However, the impact of isolation and storage procedures on recovery of breast milk EV has remained underexposed. Here, we aimed to define parameters important for EV recovery from fresh and stored breast milk. To compare various protocols across different donors, breast milk was spiked with a well-defined murine EV population. We found that centrifugation of EV down into density gradients largely improved density-based separation and isolation of EV, compared to floatation up into gradients after high-force pelleting of EV. Using cryo-electron microscopy, we identified different subpopulations of human breast milk EV and a not previously described population of lipid tubules. Additionally, the impact of cold storage on breast milk EV was investigated. We determined that storing unprocessed breast milk at −80°C or 4°C caused death of cells present in breast milk, leading to contamination of the breast milk EV population with storage-induced EV. Here, an alternative method is proposed to store breast milk samples for EV analysis at later time points. The proposed adaptations to the breast milk storage and EV isolation procedures can be applied for EV-based biomarker profiling of breast milk and functional analysis of the role of breast milk EV in the development of the neonatal immune system.

  15. Albumin to creatinine ratio in a random urine sample: Correlation with severity of preeclampsia

    Directory of Open Access Journals (Sweden)

    Fady S. Moiety

    2014-06-01

    Conclusions: Random urine ACR may be a reliable method for prediction and assessment of severity of preeclampsia. Using the estimated cut-off may add to the predictive value of such a simple quick test.

  16. Evaluation of a Class of Simple and Effective Uncertainty Methods for Sparse Samples of Random Variables and Functions

    Energy Technology Data Exchange (ETDEWEB)

    Romero, Vicente [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bonney, Matthew [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Schroeder, Benjamin [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Weirs, V. Gregory [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2017-11-01

    When very few samples of a random quantity are available from a source distribution of unknown shape, it is usually not possible to accurately infer the exact distribution from which the data samples come. Under-estimation of important quantities such as response variance and failure probabilities can result. For many engineering purposes, including design and risk analysis, we attempt to avoid under-estimation with a strategy to conservatively estimate (bound) these types of quantities -- without being overly conservative -- when only a few samples of a random quantity are available from model predictions or replicate experiments. This report examines a class of related sparse-data uncertainty representation and inference approaches that are relatively simple, inexpensive, and effective. Tradeoffs between the methods' conservatism, reliability, and risk versus number of data samples (cost) are quantified with multi-attribute metrics use d to assess method performance for conservative estimation of two representative quantities: central 95% of response; and 10-4 probability of exceeding a response threshold in a tail of the distribution. Each method's performance is characterized with 10,000 random trials on a large number of diverse and challenging distributions. The best method and number of samples to use in a given circumstance depends on the uncertainty quantity to be estimated, the PDF character, and the desired reliability of bounding the true value. On the basis of this large data base and study, a strategy is proposed for selecting the method and number of samples for attaining reasonable credibility levels in bounding these types of quantities when sparse samples of random variables or functions are available from experiments or simulations.

  17. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  18. Sampling procedure, receipt and conservation of water samples to determine environmental radioactivity; Procedimiento para el muestreo, recepcion y conservacion de muestras de agua para la determinacion de la radiactividad ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M.; Navarro, E.; Payeras, J. (and others)

    2009-07-01

    The present document informs about essential goals, processes and contents that the subgroups Samling and Samples Preparation and Conservation believe they should be part of the procedure to obtain a correct sampling, receipt, conservation and preparation of samples of continental, marine and waste water before qualifying its radioactive content.

  19. Beyond Random Walk and Metropolis-Hastings Samplers: Why You Should Not Backtrack for Unbiased Graph Sampling

    CERN Document Server

    Lee, Chul-Ho; Eun, Do Young

    2012-01-01

    Graph sampling via crawling has been actively considered as a generic and important tool for collecting uniform node samples so as to consistently estimate and uncover various characteristics of complex networks. The so-called simple random walk with re-weighting (SRW-rw) and Metropolis-Hastings (MH) algorithm have been popular in the literature for such unbiased graph sampling. However, an unavoidable downside of their core random walks -- slow diffusion over the space, can cause poor estimation accuracy. In this paper, we propose non-backtracking random walk with re-weighting (NBRW-rw) and MH algorithm with delayed acceptance (MHDA) which are theoretically guaranteed to achieve, at almost no additional cost, not only unbiased graph sampling but also higher efficiency (smaller asymptotic variance of the resulting unbiased estimators) than the SRW-rw and the MH algorithm, respectively. In particular, a remarkable feature of the MHDA is its applicability for any non-uniform node sampling like the MH algorithm,...

  20. Identifying the origin of groundwater samples in a multi-layer aquifer system with Random Forest classification

    Science.gov (United States)

    Baudron, Paul; Alonso-Sarría, Francisco; García-Aróstegui, José Luís; Cánovas-García, Fulgencio; Martínez-Vicente, David; Moreno-Brotóns, Jesús

    2013-08-01

    Accurate identification of the origin of groundwater samples is not always possible in complex multilayered aquifers. This poses a major difficulty for a reliable interpretation of geochemical results. The problem is especially severe when the information on the tubewells design is hard to obtain. This paper shows a supervised classification method based on the Random Forest (RF) machine learning technique to identify the layer from where groundwater samples were extracted. The classification rules were based on the major ion composition of the samples. We applied this method to the Campo de Cartagena multi-layer aquifer system, in southeastern Spain. A large amount of hydrogeochemical data was available, but only a limited fraction of the sampled tubewells included a reliable determination of the borehole design and, consequently, of the aquifer layer being exploited. Added difficulty was the very similar compositions of water samples extracted from different aquifer layers. Moreover, not all groundwater samples included the same geochemical variables. Despite of the difficulty of such a background, the Random Forest classification reached accuracies over 90%. These results were much better than the Linear Discriminant Analysis (LDA) and Decision Trees (CART) supervised classification methods. From a total of 1549 samples, 805 proceeded from one unique identified aquifer, 409 proceeded from a possible blend of waters from several aquifers and 335 were of unknown origin. Only 468 of the 805 unique-aquifer samples included all the chemical variables needed to calibrate and validate the models. Finally, 107 of the groundwater samples of unknown origin could be classified. Most unclassified samples did not feature a complete dataset. The uncertainty on the identification of training samples was taken in account to enhance the model. Most of the samples that could not be identified had an incomplete dataset.

  1. Soil map disaggregation improved by soil-landscape relationships, area-proportional sampling and random forest implementation

    DEFF Research Database (Denmark)

    Møller, Anders Bjørn; Malone, Brendan P.; Odgers, Nathan

    algorithm were evaluated. The resulting maps were validated on 777 soil profiles situated in a grid covering Denmark. The experiments showed that the results obtained with Jacobsen’s map were more accurate than the results obtained with the CEC map, despite a nominally coarser scale of 1:2,000,000 vs. 1...... of European Communities (CEC, 1985) respectively, both using the FAO 1974 classification. Furthermore, the effects of implementing soil-landscape relationships, using area proportional sampling instead of per polygon sampling, and replacing the default C5.0 classification tree algorithm with a random forest......:1,000,000. This finding is probably related to the fact that Jacobsen’s map was more detailed with a larger number of polygons, soil map units and soil types, despite its coarser scale. The results showed that the implementation of soil-landscape relationships, area-proportional sampling and the random forest...

  2. Measurement of density distribution of a cracking catalyst in experimental riser with a sampling procedure for gamma ray tomography

    Energy Technology Data Exchange (ETDEWEB)

    Dantas, C.C. [Department of Nuclear Energy, Federal University of Pernambuco - UFPE, Av. Prof. Luiz Freire 1000, CDU 50740-540 Recife, PE (Brazil)], E-mail: ccd@ufpe.br; Melo, S.B.; Oliveira, E.F.; Simoes, F.P.M.; Santos, M.G. dos [Informatic Center CIN, Federal University of Pernambuco - UFPE, Av. Prof. Luiz Freire 1000, CDU 50740-540 Recife, PE (Brazil); Santos, V.A. dos [Department of Chemistry, Catholic University of Pernambuco - UNICAP, Rua do Principe 526, Boa Vista, 50050-900 Recife, PE (Brazil)

    2008-03-15

    By scanning a riser the number of the gamma ray trajectories and the beam width involve temporal, spatial and density resolutions as they are closely correlated parameters. Therefore, evaluation of parameters and their interaction quantification, certainly, are required in the imaging process. Measuring the density distribution of the catalyst from the FCC - fluid cracking catalytic process in an experimental riser in single beam tomographic system, density resolution is evaluated and correlated with spatial resolution. The beam width {delta}s inside riser is measured and a criterion for determining spatial resolution is proposed. Experiments are carried out to demonstrate resolution effects of three {delta}s values: 3.30 x 10{sup -3}, 6.20 x 10{sup -3} and 12.00 x 10{sup -3} m. The gamma beam profile is modeled and a sampling rate according to Nyquist criterion is analyzed. The 4.3%, 8.1% and 15.6% ratios of {delta}s/R to internal riser radius are correlated to counting time in the sampling procedure. Results are discussed by comparison with values from literature.

  3. Measurement of density distribution of a cracking catalyst in experimental riser with a sampling procedure for gamma ray tomography

    Science.gov (United States)

    Dantas, C. C.; Melo, S. B.; Oliveira, E. F.; Simões, F. P. M.; dos Santos, M. G.; dos Santos, V. A.

    2008-03-01

    By scanning a riser the number of the gamma ray trajectories and the beam width involve temporal, spatial and density resolutions as they are closely correlated parameters. Therefore, evaluation of parameters and their interaction quantification, certainly, are required in the imaging process. Measuring the density distribution of the catalyst from the FCC - fluid cracking catalytic process in an experimental riser in single beam tomographic system, density resolution is evaluated and correlated with spatial resolution. The beam width Δs inside riser is measured and a criterion for determining spatial resolution is proposed. Experiments are carried out to demonstrate resolution effects of three Δs values: 3.30 × 10-3, 6.20 × 10-3 and 12.00 × 10-3 m. The gamma beam profile is modeled and a sampling rate according to Nyquist criterion is analyzed. The 4.3%, 8.1% and 15.6% ratios of Δs/R to internal riser radius are correlated to counting time in the sampling procedure. Results are discussed by comparison with values from literature.

  4. A sensitive analytical procedure for monitoring acrylamide in environmental water samples by offline SPE-UPLC/MS/MS.

    Science.gov (United States)

    Togola, Anne; Coureau, Charlotte; Guezennec, Anne-Gwenaëlle; Touzé, Solène

    2015-05-01

    The presence of acrylamide in natural systems is of concern from both environmental and health points of view. We developed an accurate and robust analytical procedure (offline solid phase extraction combined with UPLC/MS/MS) with a limit of quantification (20 ng L(-1)) compatible with toxicity threshold values. The optimized (considering the nature of extraction phases, sampling volumes, and solvent of elution) solid phase extraction (SPE) was validated according to ISO Standard ISO/IEC 17025 on groundwater, surface water, and industrial process water samples. Acrylamide is highly polar, which induces a high variability during the SPE step, therefore requiring the use of C(13)-labeled acrylamide as an internal standard to guarantee the accuracy and robustness of the method (uncertainty about 25 % (k = 2) at limit of quantification level). The specificity of the method and the stability of acrylamide were studied for these environmental media, and it was shown that the method is suitable for measuring acrylamide in environmental studies.

  5. A procedure for estimating Bacillus cereus spores in soil and stream-sediment samples - A potential exploration technique

    Science.gov (United States)

    Watterson, J.R.

    1985-01-01

    The presence of bacterial spores of the Bacillus cereus group in soils and stream sediments appears to be a sensitive indicator of several types of concealed mineral deposits, including vein-type gold deposits. The B. cereus assay is rapid, inexpensive, and inherently reproducible. The test, currently under investigation for its potential in mineral exploration, is recommended for use on a research basis. Among the aerobic spore-forming bacilli, only B. cereus and closely related strains produce an opaque zone in egg-yolk emulsion agar. This characteristic, also known as the Nagler of lecitho-vitellin reaction, has long been used to rapidly indentify and estimate presumptive B. cereus. The test is here adapted to permit rapid estimation of B. cereus spores in soil and stream-sediment samples. Relative standard deviation was 10.3% on counts obtained from two 40-replicate pour-plate determinations. As many as 40 samples per day can be processed. Enough procedural detail is included to permit investigation of the test in conventional geochemical laboratories using standard microbiological safety precautions. ?? 1985.

  6. Duodenum-preserving pancreatic head resection--a randomized controlled trial comparing the original Beger procedure with the Berne modification (ISRCTN No. 50638764).

    Science.gov (United States)

    Köninger, Jörg; Seiler, Christoph M; Sauerland, Stefan; Wente, Moritz N; Reidel, Margot A; Müller, Michael W; Friess, Helmut; Büchler, Markus W

    2008-04-01

    A prospective, randomized study was performed to evaluate two variations of the duodenum-preserving pancreatic head resection (DPPHR), either with (Beger procedure) or without (Berne modification) the division of the pancreas anterior to the portal vein, in patients with chronic pancreatitis. Randomized, controlled, patient-blinded trial of patients with inflammatory pancreatic head tumors. The primary endpoint was the duration of surgery. Other a priori-ordered endpoints were length of ICU stay, postoperative complication, length of hospital stay, and quality of life after 24 months. Sixty-five patients were randomized to the Berne or Beger procedures. The Berne modification could be performed faster (46 minutes difference, P Berne group (11 (8-39) versus 15 (8-47); P = .015). The quality of life two years after surgery did not differ significantly between the two groups (EORTC-QLQ-C30, Beger 65.6% vs. Berne 71.3%, P = .371). Three patients who had received the Berne procedure were reoperated on during the follow-up period due to ongoing pancreatitis and bile duct obstruction (P = .22). The Berne technique is technically simpler compared with the original Beger procedure, reflected in its significantly shorter operation times and hospital stays. The quality of life is similar after both procedures. The Berne modification of DPPHR adds to our panel of surgical procedures that can be applied with effective early and late outcomes.

  7. Can live music therapy reduce distress and pain in children with burns after wound care procedures? A randomized controlled trial.

    Science.gov (United States)

    van der Heijden, Marianne J E; Jeekel, Johannes; Rode, Heinz; Cox, Sharon; van Rosmalen, Joost; Hunink, Myriam G M; van Dijk, Monique

    2018-01-30

    Burn wound care procedures are very painful and lead to distress. Live music therapy has shown beneficial effects on distress and pain in specific pediatric patient populations. In this study we measured whether live music therapy has beneficial effects in terms of less distress and pain in children with burns after wound care procedures. This randomized assessor-blinded controlled trial (RCT) took place at the burns unit of the Red Cross War Memorial Children's Hospital, Cape Town, South Africa. It included newly admitted inpatients between the ages of 0 and 13 years undergoing their first or second wound care procedures. Excluded were children with a hearing impairment or low level of consciousness. The intervention group received one live music therapy session directly after wound care in addition to standard care. The control group received standard care only. The primary outcome was distress measured with the Observational Scale of Behavioral Distress-revised (OSBD-r). The secondary outcome was pain measured with the COMFORT-behavioral scale (COMFORT-B). In addition, in children older than 5 years self-reported distress with the validated Wong-Baker scale (FACES) and pain with the Faces Pain Scale-Revised (FPS-R) were measured. Patients in both groups were videotaped for three minutes before wound care; during the music therapy or the control condition; and for two minutes thereafter. Two researchers, blinded to the study condition, independently scored the OSBD-r and the COMFORT-B from the video footage before and after music therapy. We included 135 patients, median age 22.6 months (IQR 15.4-40.7 months). Change scores did not significantly differ between the intervention and the control groups for either distress (p=0.53; d=0.11; 95% CI -0.23 to 0.45) or pain (p=0.99; d=0.04; 95% CI -0.30 to 0.38). Self-reported distress in a small group of children (n=18) older than 5 years indicated a significant reduction in distress after live music therapy (p=0

  8. Meta-analysis of Randomized Controlled Trials Comparing Clinical Outcomes Between Short Implants and Long Implants with Bone Augmentation Procedure.

    Science.gov (United States)

    Tong, Qingchun; Zhang, Xingwen; Yu, Liming

    The purpose of this meta-analysis was to assess and compare clinical outcomes of short implants versus long implants placed in conjunction with a bone augmentation procedure. The eligible studies were searched from PubMed, Embase, Springer link, and the Cochrane library databases up to 23 January 2015. Prosthesis failures, implant failures, complications, and marginal bone loss were the clinical outcomes measured. The pooled weighted mean difference (WMD) or risk ratios (RRs) and their 95% confidence intervals (CIs) were used to measure the effect size of continuous variables and dichotomous variables, respectively. A random-effects model was performed to assess the effect size. Nine eligible studies including 480 short implants (≤ 8 mm) and 503 long implants (≥ 9.3 mm) were selected for this meta-analysis. Compared with the long-implant group, a notable decrease in the short-implant group was found for complications at the 5-year follow-up (RR = 0.34, 95% CI: 0.15 to 0.79, P .05). Moreover, the results were not obviously changed when stratified by implants placed in the mandible and maxilla. Implants ≤ 8 mm in length are considered to be a suitable alternative treatment when bone height is not adequate for standard implants.

  9. GPCR-drug interactions prediction using random forest with drug-association-matrix-based post-processing procedure.

    Science.gov (United States)

    Hu, Jun; Li, Yang; Yang, Jing-Yu; Shen, Hong-Bin; Yu, Dong-Jun

    2016-02-01

    G-protein-coupled receptors (GPCRs) are important targets of modern medicinal drugs. The accurate identification of interactions between GPCRs and drugs is of significant importance for both protein function annotations and drug discovery. In this paper, a new sequence-based predictor called TargetGDrug is designed and implemented for predicting GPCR-drug interactions. In TargetGDrug, the evolutionary feature of GPCR sequence and the wavelet-based molecular fingerprint feature of drug are integrated to form the combined feature of a GPCR-drug pair; then, the combined feature is fed to a trained random forest (RF) classifier to perform initial prediction; finally, a novel drug-association-matrix-based post-processing procedure is applied to reduce potential false positive or false negative of the initial prediction. Experimental results on benchmark datasets demonstrate the efficacy of the proposed method, and an improvement of 15% in the Matthews correlation coefficient (MCC) was observed over independent validation tests when compared with the most recently released sequence-based GPCR-drug interactions predictor. The implemented webserver, together with the datasets used in this study, is freely available for academic use at http://csbio.njust.edu.cn/bioinf/TargetGDrug. Copyright © 2015 Elsevier Ltd. All rights reserved.

  10. Gel microbead cultivation with a subenrichment procedure can yield better bacterial cultivability from a seawater sample than standard plating method

    Science.gov (United States)

    Ji, Shiqi; Zhao, Rui; Yin, Qi; Zhao, Yuan; Liu, Chenguang; Xiao, Tian; Zhang, Xiaohua

    2012-03-01

    A gel microbead (GMD) cultivation method was employed to cultivate microorganisms from an amphioxus breeding zone in Qingdao, P. R. China. The culture results were compared with those by standard plating method. In the GMD-based method, the microcolony-forming GMDs were sorted by fluorescence-activated cell sorting (FACS). To further get pure cultures, a subsequent enrichment culture and a streaking purification procedure were conducted on marine R2A medium. Eighty bacterial strains isolated by the GMD-based method were randomly selected for sequencing. These isolates belonged to Alphaproteobacteria (33%), Gammaproteobacteria (44%), Bacteroidetes (11%), Actinobacteria (5%), Firmicutes (5%), Epsilonproteobacteria (1%), and Verrucomicrobia (1%), the last two groups being usually difficult to culture. The 16S rRNA gene sequences revealed a diverse community with 91.1%-100% of the bacterial rRNAs similarities. Thirteen strains were sharing 16S rRNA gene sequence which was less than 97% similar to any other rRNA genes currently deposited in TYP16S database. Seventy isolates derived from the standard plating method fell into 4 different taxonomic groups: Alphaproteobacteria (9%), Gammaproteobacteria (81%), Bacteroidetes (7%) and Firmicutes (3%) with a 16S rRNA gene sequence similarities between 95.8%-100%, in which only 3 strains were sharing 16S rRNA gene sequence of less than 97%. The results indicated that the GMD-based method with subenrichment culture yielded more taxonomic groups and more novel microbial strains, including members of previously rarely cultured groups, when compared with the standard plating method, and that this method markedly improved the bacterial cultivability.

  11. Comparisons of sampling procedures and time of sampling for the detection of Salmonella in Danish infected chicken flocks raised in floor systems

    DEFF Research Database (Denmark)

    Gradel, K.O.; Andersen, J.; Madsen, M.

    2002-01-01

    Bacteriological follow-up samples were taken from 41 chicken (Gallus gallus) flocks in floor systems, where Salmonella enterica (Salmonella) had been detected either directly in bacteriological samples or indirectly by serological samples. Three types of follow-up samples were compared to each...... other within each flock: 1) 5 pairs of socks, analysed as 5 samples, 2) 2 pairs of socks, analysed as one sample, and 3) 60 faecal samples, analysed as one pooled sample. Agreement between sampling methods was evaluated by the following statistical tests: 'Kappa', 'The adjusted rand', McNemar"s test...

  12. Randomization tests

    CERN Document Server

    Edgington, Eugene

    2007-01-01

    Statistical Tests That Do Not Require Random Sampling Randomization Tests Numerical Examples Randomization Tests and Nonrandom Samples The Prevalence of Nonrandom Samples in Experiments The Irrelevance of Random Samples for the Typical Experiment Generalizing from Nonrandom Samples Intelligibility Respect for the Validity of Randomization Tests Versatility Practicality Precursors of Randomization Tests Other Applications of Permutation Tests Questions and Exercises Notes References Randomized Experiments Unique Benefits of Experiments Experimentation without Mani

  13. A solid phase extraction procedure for the simultaneous determination of total inorganic arsenic and trace metals in seawater: Sample preparation for total-reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Staniszewski, B. [Department of Analytical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland)], E-mail: bstanisz@amu.edu.pl; Freimann, P. [Bundesamt fuer Seeschifffahrt und Hydrographie, Wuestland 2, 22589 Hamburg (Germany)], E-mail: peter.freimann@bsh.de

    2008-11-15

    In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As{sup +3} with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L{sup -1}.

  14. A solid phase extraction procedure for the simultaneous determination of total inorganic arsenic and trace metals in seawater: Sample preparation for total-reflection X-ray fluorescence

    Science.gov (United States)

    Staniszewski, B.; Freimann, P.

    2008-11-01

    In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As +3 with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L - 1 .

  15. Finite-sample corrected generalized estimating equation of population average treatment effects in stepped wedge cluster randomized trials.

    Science.gov (United States)

    Scott, JoAnna M; deCamp, Allan; Juraska, Michal; Fay, Michael P; Gilbert, Peter B

    2017-04-01

    Stepped wedge designs are increasingly commonplace and advantageous for cluster randomized trials when it is both unethical to assign placebo, and it is logistically difficult to allocate an intervention simultaneously to many clusters. We study marginal mean models fit with generalized estimating equations for assessing treatment effectiveness in stepped wedge cluster randomized trials. This approach has advantages over the more commonly used mixed models that (1) the population-average parameters have an important interpretation for public health applications and (2) they avoid untestable assumptions on latent variable distributions and avoid parametric assumptions about error distributions, therefore, providing more robust evidence on treatment effects. However, cluster randomized trials typically have a small number of clusters, rendering the standard generalized estimating equation sandwich variance estimator biased and highly variable and hence yielding incorrect inferences. We study the usual asymptotic generalized estimating equation inferences (i.e., using sandwich variance estimators and asymptotic normality) and four small-sample corrections to generalized estimating equation for stepped wedge cluster randomized trials and for parallel cluster randomized trials as a comparison. We show by simulation that the small-sample corrections provide improvement, with one correction appearing to provide at least nominal coverage even with only 10 clusters per group. These results demonstrate the viability of the marginal mean approach for both stepped wedge and parallel cluster randomized trials. We also study the comparative performance of the corrected methods for stepped wedge and parallel designs, and describe how the methods can accommodate interval censoring of individual failure times and incorporate semiparametric efficient estimators.

  16. Random access procedures and radio access network (RAN) overload control in standard and advanced long-term evolution (LTE and LTE-A) networks

    DEFF Research Database (Denmark)

    Kiilerich Pratas, Nuno; Thomsen, Henning; Popovski, Petar

    2015-01-01

    In this chapter, we describe and discuss the current LTE random access procedure and the Radio Access Network Load Control solution within LTE/LTE-A. We provide an overview of the several considered load control solutions and give a detailed description of the standardized Extended Access Class B...

  17. Bile acid profiling in human biological samples: comparison of extraction procedures and application to normal and cholestatic patients.

    Science.gov (United States)

    Humbert, Lydie; Maubert, Marie Anne; Wolf, Claude; Duboc, Henri; Mahé, Myriam; Farabos, Dominique; Seksik, Philippe; Mallet, Jean Maurice; Trugnan, Germain; Masliah, Joëlle; Rainteau, Dominique

    2012-06-15

    The role of bile acids in cell metabolism, membrane biology and cell signaling is increasingly recognized, thus making necessary a robust and versatile technique to extract, separate and quantify a large concentration range of these numerous molecular species. HPLC-MS/MS analysis provides the highest sensitivity to detect and identify bile acids. However, due to their large chemical diversity, extraction methods are critical and quite difficult to optimize, as shown by a survey of the literature. This paper compares the performances of four bile acid extraction protocols applied to either liquid (serum, urine, bile) or solid (stool) samples. Acetonitrile was found to be the best solvent for deproteinizing liquid samples and NaOH the best one for stool extraction. These optimized extraction procedures allowed us to quantitate as much as 27 distinct bile acids including sulfated species in a unique 30 min HPLC run, including both hydrophilic and hydrophobic species with a high efficiency. Tandem MS provided a non ambiguous identification of each metabolite with a good sensitivity (LOQ below 20 nmol/l except for THDCA and TLCA). After validation, these methods, successfully applied to a group of 39 control patients, detected 14 different species in serum in the range of 30-800 nmol/l, 11 species in urine in the range of 20-200 nmol/l and 25 species in stool in the range of 0.4-2000 nmol/g. The clinical interest of this method has been then validated on cholestatic patients. The proposed protocols seem suitable for profiling bile acids in routine analysis. Copyright © 2012 Elsevier B.V. All rights reserved.

  18. Securing image information using double random phase encoding and parallel compressive sensing with updated sampling processes

    Science.gov (United States)

    Hu, Guiqiang; Xiao, Di; Wang, Yong; Xiang, Tao; Zhou, Qing

    2017-11-01

    Recently, a new kind of image encryption approach using compressive sensing (CS) and double random phase encoding has received much attention due to the advantages such as compressibility and robustness. However, this approach is found to be vulnerable to chosen plaintext attack (CPA) if the CS measurement matrix is re-used. Therefore, designing an efficient measurement matrix updating mechanism that ensures resistance to CPA is of practical significance. In this paper, we provide a novel solution to update the CS measurement matrix by altering the secret sparse basis with the help of counter mode operation. Particularly, the secret sparse basis is implemented by a reality-preserving fractional cosine transform matrix. Compared with the conventional CS-based cryptosystem that totally generates all the random entries of measurement matrix, our scheme owns efficiency superiority while guaranteeing resistance to CPA. Experimental and analysis results show that the proposed scheme has a good security performance and has robustness against noise and occlusion.

  19. Influence of plasma cleaning procedure on the interaction between soft tissue and abutments: a randomized controlled histologic study.

    Science.gov (United States)

    Garcia, Berta; Camacho, Fabio; Peñarrocha, David; Tallarico, Marco; Perez, Sara; Canullo, Luigi

    2017-10-01

    Plasma application can lead to an improved adhesion between soft tissue and abutments and promotes cell spreading. A triple-blinded randomized controlled clinical trial was performed to in vivo test the effect of cleaning abutment titanium surfaces with plasma of argon on cell adhesion and collagen fiber orientation at an early healing time. Thirty healthy patients with 30 submerged implants, at the second surgery, randomly received either a specially designed abutment with no additional treatment (as they come from industry; control group, G1) or cleaned by plasma of argon (test group, G2). Two weeks thereafter, a small biopsy including abutment and soft tissues around the abutment was performed. Abutments were analyzed using scanning electron microscopy to assess cell adhesion to the abutment surface. Outcome measures were the following: percentage of area occupied by cells, the presence or absence of cells, aspect of adhered cells, and the presence of contaminants. At the same time, the soft tissue histological analysis evaluated density and orientation of collagen fibers. Statistical analysis was performed using the Kolmogorov-Smirnov normality test and Levene variance homogeneity test. Data were analyzed using a nonparametric ranking test. The associations between the different qualitative variables were studied using Pearson's chi-squared test. The Mann-Whitney U-test (for two independent samples) was applied for quantitative variables. Mean percentages of area occupied by cells were 15.14% (range 2.91-44.27) and 33.75% (range 2.37-68.4) for G1 and G2, respectively. Differences were close to significance (P = 0.089). The proportion of samples presenting adhered cells was homogeneous between the two groups (P = 0.142). In all cases, cells presented a flattened aspect, but not in three cases in the G2; in 17 cases, cells were efficiently adhered, and in 11 cases, cells presented filopodia with no statistical differences between groups (P > 0.05). No case

  20. Alcohol and marijuana use in adolescents' daily lives: a random sample of experiences.

    Science.gov (United States)

    Larson, R; Csikszentmihalyi, M; Freeman, M

    1984-07-01

    High school students filled out reports on their experiences at random times during their daily lives, including 48 occasions when they were using alcohol or marijuana. Alcohol use was reported primarily in the context of Friday and Saturday night social gatherings and was associated with a happy and gregarious subjective state. Marijuana use was reported across a wider range of situations and was associated with an average state that differed much less from ordinary experience.

  1. Stemflow estimation in a redwood forest using model-based stratified random sampling

    Science.gov (United States)

    Jack Lewis

    2003-01-01

    Model-based stratified sampling is illustrated by a case study of stemflow volume in a redwood forest. The approach is actually a model-assisted sampling design in which auxiliary information (tree diameter) is utilized in the design of stratum boundaries to optimize the efficiency of a regression or ratio estimator. The auxiliary information is utilized in both the...

  2. Random or systematic sampling to detect a localised microbial contamination within a batch of food

    NARCIS (Netherlands)

    Jongenburger, I.; Reij, M.W.; Boer, E.P.J.; Gorris, L.G.M.; Zwietering, M.H.

    2011-01-01

    Pathogenic microorganisms are known to be distributed heterogeneously in food products that are solid, semi-solid or powdered, like for instance peanut butter, cereals, or powdered milk. This complicates effective detection of the pathogens by sampling. Two-class sampling plans, which are deployed

  3. Effectiveness of sublingual nitroglycerin before puncture compared with conventional intra-arterial nitroglycerin in transradial procedures: a randomized trial

    Energy Technology Data Exchange (ETDEWEB)

    Turan, Burak, E-mail: drburakturan@gmail.com; Daşlı, Tolga; Erkol, Ayhan; Erden, İsmail

    2015-10-15

    Aim: Sublingual (SL) nitroglycerin administered before radial artery puncture can improve cannulation success and decrease the incidence of radial artery spasm (RAS) compared with intra-arterial (IA) nitroglycerin in transradial procedures. Methods: Patients undergoing diagnostic transradial angiography were randomized to IA (200 mcg) or SL (400 mcg) nitroglycerin. Primary endpoints were puncture time and puncture attempts. Secondary endpoint was the incidence of RAS. Results: Total of 101 participants (mean age 60 ± 11 years, 53% male) were randomized (51 in IA and 50 in SL groups). Puncture time (50 [36–75] vs 50 [35–90] sec), puncture attempts (1.18 ± 0.48 vs 1.20 ± 0.49), multiple punctures (13.7 vs 16.0%) and RAS (19.6 vs 24.0%) were not statistically different between IA vs SL groups respectively. A composite endpoint of all adverse events related to transradial angiography (multiple punctures, RAS, access site crossover, hypotension/bradycardia associated with nitroglycerin and radial artery occlusion) was very similar in IA vs SL groups (39 vs 40%, respectively). However puncture time was significantly longer with SL nitroglycerin in patients < 1.65 m height (47 [36–66] vs 63 [41–110] sec, p = 0.042). Multiple punctures seemed higher with SL nitroglycerin in patients with diabetes (0 vs 30%, p = 0.028) or in patients < 1.65 m height (7.4 vs 25%, p = 0.085). Likewise, RAS with SL nitroglycerin seemed more frequent in smokers compared to IA nitroglycerin (0 vs 27%, p = 0.089). Conclusions: SL nitroglycerin was not different from IA nitroglycerin in terms of efficiency and safety in overall study population. However it may be inferior to IA nitroglycerin in certain subgroups (shorter individuals, diabetics and smokers). - Highlights: • Improvement in radial artery puncture time and success with subcutaneous nitrate was reported. • Giving nitrate sublingually may have vasodilation along entire length of radial artery and may prevent RAS

  4. Random sampling technique for ultra-fast computations of molecular opacities for exoplanet atmospheres

    Science.gov (United States)

    Min, M.

    2017-10-01

    Context. Opacities of molecules in exoplanet atmospheres rely on increasingly detailed line-lists for these molecules. The line lists available today contain for many species up to several billions of lines. Computation of the spectral line profile created by pressure and temperature broadening, the Voigt profile, of all of these lines is becoming a computational challenge. Aims: We aim to create a method to compute the Voigt profile in a way that automatically focusses the computation time into the strongest lines, while still maintaining the continuum contribution of the high number of weaker lines. Methods: Here, we outline a statistical line sampling technique that samples the Voigt profile quickly and with high accuracy. The number of samples is adjusted to the strength of the line and the local spectral line density. This automatically provides high accuracy line shapes for strong lines or lines that are spectrally isolated. The line sampling technique automatically preserves the integrated line opacity for all lines, thereby also providing the continuum opacity created by the large number of weak lines at very low computational cost. Results: The line sampling technique is tested for accuracy when computing line spectra and correlated-k tables. Extremely fast computations ( 3.5 × 105 lines per second per core on a standard current day desktop computer) with high accuracy (≤1% almost everywhere) are obtained. A detailed recipe on how to perform the computations is given.

  5. Hybrid random walk-linear discriminant analysis method for unwrapping quantitative phase microscopy images of biological samples

    Science.gov (United States)

    Kim, Diane N. H.; Teitell, Michael A.; Reed, Jason; Zangle, Thomas A.

    2015-11-01

    Standard algorithms for phase unwrapping often fail for interferometric quantitative phase imaging (QPI) of biological samples due to the variable morphology of these samples and the requirement to image at low light intensities to avoid phototoxicity. We describe a new algorithm combining random walk-based image segmentation with linear discriminant analysis (LDA)-based feature detection, using assumptions about the morphology of biological samples to account for phase ambiguities when standard methods have failed. We present three versions of our method: first, a method for LDA image segmentation based on a manually compiled training dataset; second, a method using a random walker (RW) algorithm informed by the assumed properties of a biological phase image; and third, an algorithm which combines LDA-based edge detection with an efficient RW algorithm. We show that the combination of LDA plus the RW algorithm gives the best overall performance with little speed penalty compared to LDA alone, and that this algorithm can be further optimized using a genetic algorithm to yield superior performance for phase unwrapping of QPI data from biological samples.

  6. Multivariate technique for optimization of digestion procedure by focussed microwave system for determination of Mn, Zn and Fe in food samples using FAAS

    OpenAIRE

    Bezerra, Marcos de Almeida; Ferreira, Sergio Luis Costa; Santelli,Ricardo Erthal; SantAna, Otoniel Domingos de; Cassella, Ricardo Jorgensen

    2006-01-01

    This article describes the development by response surface methodology (RSM) of a procedure for iron, zinc and manganese determination by flame atomic absorption spectrometry (FAAS) in food samples after digestion employing a focussed microwave system. A Doehlert matrix was used to find optimal conditions for the procedure through response surface study. Three variables (irradiation power and time and composition of oxidant solution—HNO3 + H2O2) were regarded as factors in the optimization st...

  7. A Split Mouth Randomized Clinical Comparative Study to Evaluate the Efficacy of Gingival Depigmentation Procedure Using Conventional Scalpel Technique or Diode Laser.

    Science.gov (United States)

    Suragimath, Girish; Lohana, Mohini Hemant; Varma, Siddhartha

    2016-01-01

    Introduction: Dark or black coloured gingiva is an esthetic concern especially in subjects with high lip line or gummy smile. Gingival depigmentation procedure is a type of perioplastic surgery where the gingival epithelium is excised with various techniques to lighten the colour of the gingiva. The aim of this study was to compare the clinical efficacy of gingival depigmentation procedure with conventional scalpel technique and diode laser application. Methods: This split mouth randomized study was conducted on 12 subjects (18-40 years of age), exhibiting melanin hyperpigmentation of gingiva. The anterior labial sextant of maxilla and mandible were divided into two halves involving three anterior teeth i.e. central incisor, lateral incisor and canine on each side. The divided areas were randomly allotted for depigmentation procedure either with scalpel technique or diode laser operating at 980 nm wavelength. Various parameters such as bleeding, pain, difficulty of procedure and wound healing were assessed and compared between the two techniques. The level of melanin pigment was assessed with Dummette Gupta index and photographic analysis with the help of adobe software. The subjects were followed up to one year to see for recurrence of melanin pigmentation. Results: Bleeding during surgery, pain score and difficulty of procedure assessed by the operator were statistically higher for scalpel technique as compared to laser technique. Wound healing did not show any statistical significant difference between both techniques. Gingival depigmentation procedures with scalpel as well as laser technique were effective when compared preoperatively and at consecutive postoperative visits, and this was statistically significant. Comparison of melanin depigmentation procedure between scalpel and laser technique did not show any significant differences at all postoperative intervals. Conclusion: The findings of the present study suggest that gingival depigmentation was

  8. THE RHETORICAL USE OF RANDOM SAMPLING: CRAFTING AND COMMUNICATING THE PUBLIC IMAGE OF POLLS AS A SCIENCE (1935-1948).

    Science.gov (United States)

    Lusinchi, Dominic

    2017-03-01

    The scientific pollsters (Archibald Crossley, George H. Gallup, and Elmo Roper) emerged onto the American news media scene in 1935. Much of what they did in the following years (1935-1948) was to promote both the political and scientific legitimacy of their enterprise. They sought to be recognized as the sole legitimate producers of public opinion. In this essay I examine the, mostly overlooked, rhetorical work deployed by the pollsters to publicize the scientific credentials of their polling activities, and the central role the concept of sampling has had in that pursuit. First, they distanced themselves from the failed straw poll by claiming that their sampling methodology based on quotas was informed by science. Second, although in practice they did not use random sampling, they relied on it rhetorically to derive the symbolic benefits of being associated with the "laws of probability." © 2017 Wiley Periodicals, Inc.

  9. Multivariate Multi-Objective Allocation in Stratified Random Sampling: A Game Theoretic Approach.

    Science.gov (United States)

    Muhammad, Yousaf Shad; Hussain, Ijaz; Shoukry, Alaa Mohamd

    2016-01-01

    We consider the problem of multivariate multi-objective allocation where no or limited information is available within the stratum variance. Results show that a game theoretic approach (based on weighted goal programming) can be applied to sample size allocation problems. We use simulation technique to determine payoff matrix and to solve a minimax game.

  10. The effect of dead time on randomly sampled power spectral estimates

    DEFF Research Database (Denmark)

    Buchhave, Preben; Velte, Clara Marika; George, William K.

    2014-01-01

    consider both the effect on the measured spectrum of a finite sampling time, i.e., a finite time during which the signal is acquired, and a finite dead time, that is a time in which the signal processor is busy evaluating a data point and therefore unable to measure a subsequent data point arriving within...... the dead time delay....

  11. Phase microscopy of technical and biological samples through random phase modulation with a difuser

    DEFF Research Database (Denmark)

    Almoro, Percival; Pedrini, Giancarlo; Gundu, Phanindra Narayan

    2010-01-01

    A technique for phase microscopy using a phase diffuser and a reconstruction algorithm is proposed. A magnified specimen wavefront is projected on the diffuser plane that modulates the wavefront into a speckle field. The speckle patterns at axially displaced planes are sampled and used in an iter...

  12. Avaliação de procedimentos de preparo de amostra de amendoim in natura para análise de aflatoxinas Evaluation of sample preparation procedures for aflatoxin analysis in raw peanut

    Directory of Open Access Journals (Sweden)

    Maria Antonia Calori-Domingues

    2010-01-01

    Full Text Available The variability in aflatoxin B1 concentration among peanut subsamples of 4 sample preparation procedures was evaluated. For each procedure, 18 samples were prepared involving dry comminuting/homogenization or dry roughly comminuting followed by the preparation of a aqueous slurry. Ten analytical samples were withdrawn from each sample/procedure and analyzed by thin layer chromatography. The coefficient of variation (CV% among each set of 10 analytical samples was assumed to be associated with the sample preparation procedure. The procedure that made use of a subsample mill and preparation of a subsample slurry, showed lower variability (CV% among the analytical subsamples.

  13. Random Evolutionary Dynamics Driven by Fitness and House-of-Cards Mutations: Sampling Formulae

    Science.gov (United States)

    Huillet, Thierry E.

    2017-07-01

    We first revisit the multi-allelic mutation-fitness balance problem, especially when mutations obey a house of cards condition, where the discrete-time deterministic evolutionary dynamics of the allelic frequencies derives from a Shahshahani potential. We then consider multi-allelic Wright-Fisher stochastic models whose deviation to neutrality is from the Shahshahani mutation/selection potential. We next focus on the weak selection, weak mutation cases and, making use of a Gamma calculus, we compute the normalizing partition functions of the invariant probability densities appearing in their Wright-Fisher diffusive approximations. Using these results, generalized Ewens sampling formulae (ESF) from the equilibrium distributions are derived. We start treating the ESF in the mixed mutation/selection potential case and then we restrict ourselves to the ESF in the simpler house-of-cards mutations only situation. We also address some issues concerning sampling problems from infinitely-many alleles weak limits.

  14. Dual to Ratio-Cum-Product Estimator in Simple and Stratified Random Sampling

    OpenAIRE

    Yunusa Olufadi

    2013-01-01

    New estimators for estimating the finite population mean using two auxiliary variables under simple and stratified sampling design is proposed. Their properties (e.g., mean square error) are studied to the first order of approximation. More so, some estimators are shown to be a particular member of this estimator. Furthermore, comparison of the proposed estimator with the usual unbiased estimator and other estimators considered in this paper reveals interesting results. These results are fur...

  15. The psychometric properties of the AUDIT: a survey from a random sample of elderly Swedish adults.

    Science.gov (United States)

    Källmén, Håkan; Wennberg, Peter; Ramstedt, Mats; Hallgren, Mats

    2014-07-01

    Increasing alcohol consumption and related harms have been reported among the elderly population of Europe. Consequently, it is important to monitor patterns of alcohol use, and to use a valid and reliable tool when screening for risky consumption in this age group. The aim was to evaluate the internal consistency reliability and construct validity of the Alcohol Use Disorders Identification Test (AUDIT) in elderly Swedish adults, and to compare the results with the general Swedish population. Another aim was to calculate the level of alcohol consumption (AUDIT-C) to be used for comparison in future studies. The questionnaire was sent to 1459 Swedish adults aged 79-80 years with a response rate of 73.3%. Internal consistency reliability, were assessed using Cronbach alpha, and confirmatory factor analysis assessed construct validity of the Alcohol Use Disorders Identification Test (AUDIT) in elderly population as compared to a Swedish general population sample. The results showed that AUDIT was more reliable and valid among the Swedish general population sample than among the elderly and that Item 1 and 4 in AUDIT was less reliable and valid among the elderly. While the AUDIT showed acceptable psychometric properties in the general population sample, it's performance was of less quality among the elderly respondents. Further psychometric assessments of the AUDIT in elderly populations are required before it is implemented more widely.

  16. The quality of the reported sample size calculations in randomized controlled trials indexed in PubMed.

    Science.gov (United States)

    Lee, Paul H; Tse, Andy C Y

    2017-05-01

    There are limited data on the quality of reporting of information essential for replication of the calculation as well as the accuracy of the sample size calculation. We examine the current quality of reporting of the sample size calculation in randomized controlled trials (RCTs) published in PubMed and to examine the variation in reporting across study design, study characteristics, and journal impact factor. We also reviewed the targeted sample size reported in trial registries. We reviewed and analyzed all RCTs published in December 2014 with journals indexed in PubMed. The 2014 Impact Factors for the journals were used as proxies for their quality. Of the 451 analyzed papers, 58.1% reported an a priori sample size calculation. Nearly all papers provided the level of significance (97.7%) and desired power (96.6%), and most of the papers reported the minimum clinically important effect size (73.3%). The median (inter-quartile range) of the percentage difference of the reported and calculated sample size calculation was 0.0% (IQR -4.6%;3.0%). The accuracy of the reported sample size was better for studies published in journals that endorsed the CONSORT statement and journals with an impact factor. A total of 98 papers had provided targeted sample size on trial registries and about two-third of these papers (n=62) reported sample size calculation, but only 25 (40.3%) had no discrepancy with the reported number in the trial registries. The reporting of the sample size calculation in RCTs published in PubMed-indexed journals and trial registries were poor. The CONSORT statement should be more widely endorsed. Copyright © 2016 European Federation of Internal Medicine. Published by Elsevier B.V. All rights reserved.

  17. Active Learning Not Associated with Student Learning in a Random Sample of College Biology Courses

    Science.gov (United States)

    Andrews, T. M.; Leonard, M. J.; Colgrove, C. A.; Kalinowski, S. T.

    2011-01-01

    Previous research has suggested that adding active learning to traditional college science lectures substantially improves student learning. However, this research predominantly studied courses taught by science education researchers, who are likely to have exceptional teaching expertise. The present study investigated introductory biology courses randomly selected from a list of prominent colleges and universities to include instructors representing a broader population. We examined the relationship between active learning and student learning in the subject area of natural selection. We found no association between student learning gains and the use of active-learning instruction. Although active learning has the potential to substantially improve student learning, this research suggests that active learning, as used by typical college biology instructors, is not associated with greater learning gains. We contend that most instructors lack the rich and nuanced understanding of teaching and learning that science education researchers have developed. Therefore, active learning as designed and implemented by typical college biology instructors may superficially resemble active learning used by education researchers, but lacks the constructivist elements necessary for improving learning. PMID:22135373

  18. Effect of the Mediterranean diet on heart failure biomarkers: a randomized sample from the PREDIMED trial.

    Science.gov (United States)

    Fitó, Montserrat; Estruch, Ramón; Salas-Salvadó, Jordi; Martínez-Gonzalez, Miguel Angel; Arós, Fernando; Vila, Joan; Corella, Dolores; Díaz, Oscar; Sáez, Guillermo; de la Torre, Rafael; Mitjavila, María-Teresa; Muñoz, Miguel Angel; Lamuela-Raventós, Rosa-María; Ruiz-Gutierrez, Valentina; Fiol, Miquel; Gómez-Gracia, Enrique; Lapetra, José; Ros, Emilio; Serra-Majem, Lluis; Covas, María-Isabel

    2014-05-01

    Scarce data are available on the effect of the traditional Mediterranean diet (TMD) on heart failure biomarkers. We assessed the effect of TMD on biomarkers related to heart failure in a high cardiovascular disease risk population. A total of 930 subjects at high cardiovascular risk (420 men and 510 women) were recruited in the framework of a multicentre, randomized, controlled, parallel-group clinical trial directed at testing the efficacy of the TMD on the primary prevention of cardiovascular disease (The PREDIMED Study). Participants were assigned to a low-fat diet (control, n = 310) or one of two TMDs [TMD + virgin olive oil (VOO) or TMD + nuts]. Depending on group assignment, participants received free provision of extra-virgin olive oil, mixed nuts, or small non-food gifts. After 1 year of intervention, both TMDs decreased plasma N-terminal pro-brain natriuretic peptide, with changes reaching significance vs. control group (P cardiovascular disease (CVD) who improved their diet toward a TMD pattern reduced their N-terminal pro-brain natriuretic peptide compared with those assigned to a low-fat diet. The same was found for in vivo oxidized low-density lipoprotein and lipoprotein(a) plasma concentrations after the TMD + VOO diet. From our results TMD could be a useful tool to mitigate against risk factors for heart failure. From our results TMD could modify markers of heart failure towards a more protective mode. © 2014 The Authors. European Journal of Heart Failure © 2014 European Society of Cardiology.

  19. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order.

    Science.gov (United States)

    Diederich, Adele; Oswald, Peter

    2014-01-01

    A sequential sampling model for multiattribute binary choice options, called multiattribute attention switching (MAAS) model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered-the attention time-influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability p 0 > 0 of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process.

  20. Sequential sampling model for multiattribute choice alternatives with random attention time and processing order

    Directory of Open Access Journals (Sweden)

    Adele eDiederich

    2014-09-01

    Full Text Available A sequential sampling model for multiattribute binary choice options, called Multiattribute attention switching (MAAS model, assumes a separate sampling process for each attribute. During the deliberation process attention switches from one attribute consideration to the next. The order in which attributes are considered as well for how long each attribute is considered - the attention time - influences the predicted choice probabilities and choice response times. Several probability distributions for the attention time including deterministic, Poisson, binomial, geometric, and uniform with different variances are investigated. Depending on the time and order schedule the model predicts a rich choice probability/choice response time pattern including preference reversals and fast errors. Furthermore, the difference between a finite and infinite decision horizons for the attribute considered last is investigated. For the former case the model predicts a probability $p_0> 0$ of not deciding within the available time. The underlying stochastic process for each attribute is an Ornstein-Uhlenbeck process approximated by a discrete birth-death process. All predictions are also true for the widely applied Wiener process.

  1. Incorporating covariance estimation uncertainty in spatial sampling design for prediction with trans-Gaussian random fields

    Directory of Open Access Journals (Sweden)

    Gunter eSpöck

    2015-05-01

    Full Text Available Recently, Spock and Pilz [38], demonstratedthat the spatial sampling design problem forthe Bayesian linear kriging predictor can betransformed to an equivalent experimentaldesign problem for a linear regression modelwith stochastic regression coefficients anduncorrelated errors. The stochastic regressioncoefficients derive from the polar spectralapproximation of the residual process. Thus,standard optimal convex experimental designtheory can be used to calculate optimal spatialsampling designs. The design functionals ̈considered in Spock and Pilz [38] did nottake into account the fact that kriging isactually a plug-in predictor which uses theestimated covariance function. The resultingoptimal designs were close to space-fillingconfigurations, because the design criteriondid not consider the uncertainty of thecovariance function.In this paper we also assume that thecovariance function is estimated, e.g., byrestricted maximum likelihood (REML. Wethen develop a design criterion that fully takesaccount of the covariance uncertainty. Theresulting designs are less regular and space-filling compared to those ignoring covarianceuncertainty. The new designs, however, alsorequire some closely spaced samples in orderto improve the estimate of the covariancefunction. We also relax the assumption ofGaussian observations and assume that thedata is transformed to Gaussianity by meansof the Box-Cox transformation. The resultingprediction method is known as trans-Gaussiankriging. We apply the Smith and Zhu [37]approach to this kriging method and show thatresulting optimal designs also depend on theavailable data. We illustrate our results witha data set of monthly rainfall measurementsfrom Upper Austria.

  2. Comparison of Detrusor Muscle Sampling Rate in Monopolar and Bipolar Transurethral Resection of Bladder Tumor: A Randomized Trial.

    Science.gov (United States)

    Teoh, Jeremy Yuen-Chun; Chan, Eddie Shu-Yin; Yip, Siu-Ying; Tam, Ho-Man; Chiu, Peter Ka-Fung; Yee, Chi-Hang; Wong, Hon-Ming; Chan, Chi-Kwok; Hou, Simon See-Ming; Ng, Chi-Fai

    2017-05-01

    Our aim was to investigate the detrusor muscle sampling rate after monopolar versus bipolar transurethral resection of bladder tumor (TURBT). This was a single-center, prospective, randomized, phase III trial on monopolar versus bipolar TURBT. Baseline patient characteristics, disease characteristics and perioperative outcomes were compared, with the primary outcome being the detrusor muscle sampling rate in the TURBT specimen. Multivariate logistic regression analyses on detrusor muscle sampling were performed. From May 2012 to December 2015, a total of 160 patients with similar baseline characteristics were randomized to receive monopolar or bipolar TURBT. Fewer patients in the bipolar TURBT group required postoperative irrigation than patients in the monopolar TURBT group (18.7 vs. 43%; p = 0.001). In the whole cohort, no significant difference in the detrusor muscle sampling rates was observed between the bipolar and monopolar TURBT groups (77.3 vs. 63.3%; p = 0.057). In patients with urothelial carcinoma, bipolar TURBT achieved a higher detrusor muscle sampling rate than monopolar TURBT (84.6 vs. 67.7%; p = 0.025). On multivariate analyses, bipolar TURBT (odds ratio [OR] 2.23, 95% confidence interval [CI] 1.03-4.81; p = 0.042) and larger tumor size (OR 1.04, 95% CI 1.01-1.08; p = 0.022) were significantly associated with detrusor muscle sampling in the whole cohort. In addition, bipolar TURBT (OR 2.88, 95% CI 1.10-7.53; p = 0.031), larger tumor size (OR 1.05, 95% CI 1.01-1.10; p = 0.035), and female sex (OR 3.25, 95% CI 1.10-9.59; p = 0.033) were significantly associated with detrusor muscle sampling in patients with urothelial carcinoma. There was a trend towards a superior detrusor muscle sampling rate after bipolar TURBT. Further studies are needed to determine its implications on disease recurrence and progression.

  3. Multivariate technique for optimization of digestion procedure by focussed microwave system for determination of Mn, Zn and Fe in food samples using FAAS.

    Science.gov (United States)

    Santelli, Ricardo Erthal; Bezerra, Marcos de Almeida; de Santana, Otoniel Domingos; Cassella, Ricardo Jorgensen; Ferreira, Sérgio Luis Costa

    2006-02-15

    This article describes the development by response surface methodology (RSM) of a procedure for iron, zinc and manganese determination by flame atomic absorption spectrometry (FAAS) in food samples after digestion employing a focussed microwave system. A Doehlert matrix was used to find optimal conditions for the procedure through response surface study. Three variables (irradiation power and time and composition of oxidant solution-HNO(3)+H(2)O(2)) were regarded as factors in the optimization study. The working conditions were established as a compromise between optimum values found for each analyte taking into consideration the robustness of the procedure. These values were 12min, 260W and 42% (v/v) for irradiation time, irradiation power and percent of H(2)O(2) in solution, respectively. The accuracy of the optimized procedure was evaluated by analysis of certified reference materials and by comparison with a well-established closed vessel microwave dissolution methodology.

  4. Determining optimal sample sizes for multistage adaptive randomized clinical trials from an industry perspective using value of information methods.

    Science.gov (United States)

    Chen, Maggie H; Willan, Andrew R

    2013-02-01

    Most often, sample size determinations for randomized clinical trials are based on frequentist approaches that depend on somewhat arbitrarily chosen factors, such as type I and II error probabilities and the smallest clinically important difference. As an alternative, many authors have proposed decision-theoretic (full Bayesian) approaches, often referred to as value of information methods that attempt to determine the sample size that maximizes the difference between the trial's expected utility and its expected cost, referred to as the expected net gain. Taking an industry perspective, Willan proposes a solution in which the trial's utility is the increase in expected profit. Furthermore, Willan and Kowgier, taking a societal perspective, show that multistage designs can increase expected net gain. The purpose of this article is to determine the optimal sample size using value of information methods for industry-based, multistage adaptive randomized clinical trials, and to demonstrate the increase in expected net gain realized. At the end of each stage, the trial's sponsor must decide between three actions: continue to the next stage, stop the trial and seek regulatory approval, or stop the trial and abandon the drug. A model for expected total profit is proposed that includes consideration of per-patient profit, disease incidence, time horizon, trial duration, market share, and the relationship between trial results and probability of regulatory approval. The proposed method is extended to include multistage designs with a solution provided for a two-stage design. An example is given. Significant increases in the expected net gain are realized by using multistage designs. The complexity of the solutions increases with the number of stages, although far simpler near-optimal solutions exist. The method relies on the central limit theorem, assuming that the sample size is sufficiently large so that the relevant statistics are normally distributed. From a value of

  5. Comparison of intra-procedural pain between a novel continuous arteriovenous exchange and conventional pull-push techniques of partial exchange transfusion in neonates: a randomized controlled trial.

    Science.gov (United States)

    Patil, S; Saini, S S; Kumar, P; Shah, R

    2014-09-01

    We compared intra-procedural neonatal pain, agitation and sedation scale (N-PASS) scores between a novel 'continuous arteriovenous exchange' (CAVE) and conventional pull-push (PP) techniques of partial exchange transfusion (PET) among neonates with polycythemia. Neonates >32-0/7 weeks gestation, requiring PET for polycythemia, were randomized to PP or CAVE techniques. The procedure was video-recorded and edited to mask the technique. Intra-procedural N-PASS scores assigned by two trained and masked neonatal fellows were compared. Twenty-two neonates were randomized to CAVE (n=12) or PP (n=10) method. The area under curve for cumulative N-PASS scores was significantly lesser in CAVE group (mean difference-11.9 (95% CI=-4.2, -19.6), P=0.005)). Decrease in hematocrit and complications of PET were comparable. Time for PET was longer with CAVE technique (16 (9, 29) min vs 10 (6, 12) min, P=0.016). CAVE technique of PET was associated with lesser procedure-related pain (N-PASS scores) as compared with PP technique among neonates >32 weeks gestation.

  6. Is Virtual Reality Ready for Prime Time in the Medical Space? A Randomized Control Trial of Pediatric Virtual Reality for Acute Procedural Pain Management.

    Science.gov (United States)

    Gold, Jeffrey I; Mahrer, Nicole E

    2017-10-19

    To conduct a randomized control trial to evaluate the feasibility and efficacy of virtual reality (VR) compared with standard of care (SOC) for reducing pain, anxiety, and improving satisfaction associated with blood draw in children ages 10-21 years. In total, 143 triads (patients, their caregiver, and the phlebotomist) were recruited in outpatient phlebotomy at a pediatric hospital and randomized to receive either VR or SOC when undergoing routine blood draw. Patients and caregivers completed preprocedural and postprocedural standardized measures of pain, anxiety, and satisfaction, and phlebotomists reported about the patient's experience during the procedure. Findings showed that VR significantly reduced acute procedural pain and anxiety compared with SOC. A significant interaction between patient-reported anxiety sensitivity and treatment condition indicated that patients undergoing routine blood draw benefit more from VR intervention when they are more fearful of physiological sensations related to anxiety. Patients and caregivers in the VR condition reported high levels of satisfaction with the procedure. VR is feasible, tolerated, and well-liked by patients, caregivers, and phlebotomists alike for routine blood draw. Given the immersive and engaging nature of the VR experience, VR has the capacity to act as a preventive intervention transforming the blood draw experience into a less distressing, potentially pain-free routine medical procedure, particularly for pediatric patients with high anxiety sensitivity. VR holds promise to reduce negative health outcomes for children and reduce distress in caregivers, while facilitating increased satisfaction and throughput in hectic outpatient phlebotomy clinics.

  7. How effective is tetracaine 4% gel, before a venipuncture, in reducing procedural pain in infants: a randomized double-blind placebo controlled trial

    Directory of Open Access Journals (Sweden)

    Sherlock Rebecca

    2007-02-01

    Full Text Available Abstract Background Procedural pain relief is sub-optimal in neonates. Topical tetracaine provides pain relief in children. Evidence of its efficacy and safety in neonates is limited. The objective of this study was to assess the efficacy and safety of topical tetracaine on the pain response of neonates during a venipuncture. Methods Medically stable infants greater than or equal to 24 weeks gestation, requiring a venipuncture, were included. Following randomization and double blinding, 1.1 g of tetracaine or placebo was applied to the skin for 30 minutes. Participants received oral sucrose if they met local eligibility criteria. The venipuncture was performed according to a standard protocol. A medium effect size in the pain score (corresponding to about 2 point difference in the PIPP score was considered clinically significant, leading to a sample size of 142 infants, with 80% statistical power. Local skin reactions and immediate adverse cardiorespiratory events were noted. The primary outcome, PIPP score at 1 minute, was analysed using an independent Student's t-test. Results One hundred and forty two infants were included, 33 +/- 4 weeks gestation, 2100 +/- 900 grams and 6 +/- 3 days of age. There was almost no difference in PIPP scores at 1 minute between groups (mean difference -0.09; 95% confidence interval [CI]: -1.68 to 1.50; P = . 91. Similarly, there were no differences in PIPP scores during the 2nd, 3rd and 4th minute. Duration of cry did not differ between the groups (median difference, 0; 95% CI, -3 to 0; P = . 84. The majority of infants in both groups received sucrose 24%. Sucrose had a significant effect on the PIPP score, as assessed by an ANOVA model (p = 0.0026. Local skin erythema was observed transiently in 11 infants (7 in the tetracaine and 4 in the placebo group. No serious side effect was observed. Conclusion Tetracaine did not significantly decrease procedural pain in infants undergoing a venipuncture, when used in

  8. How effective is tetracaine 4% gel, before a peripherally inserted central catheter, in reducing procedural pain in infants: a randomized double-blind placebo controlled trial [ISRCTN75884221

    Directory of Open Access Journals (Sweden)

    Blanchard Colline

    2006-05-01

    Full Text Available Abstract Background Procedural pain relief is sub-optimal in infants, especially small and vulnerable ones. Tetracaine gel 4% (Ametop®, Smith-Nephew provides pain relief in children and larger infants, but its efficacy in smaller infants and for peripherally inserted central catheters (PICC remains uncertain. The objective of this trial was to assess the safety and efficacy of tetracaine gel on the pain response of very low birth weight (VLBW infants during insertion of a PICC. Methods Medically stable infants greater than or equal to 24 weeks gestation, requiring a non-urgent PICC, were included. Following randomization and double blinding, 1.1 g of tetracaine or placebo was applied to the skin for 30 minutes. The PICC was inserted according to a standard protocol. Pain was assessed using the Premature Infant Pain Profile (PIPP. A 3-point change in the pain score was considered clinically significant, leading to a sample size of 54 infants, with 90% statistical power. Local skin reactions and immediate adverse cardiorespiratory events were noted. The primary outcome, PIPP score at 1 minute, was analysed using an independent Student's t-test. Results Fifty-four infants were included, 27 +/- 2 weeks gestation, 916 +/- 292 grams and 6.5 +/- 3.2 days of age. Baseline characteristics were similar between groups. The mean PIPP score in the first minute was 10.88 in the treatment group as compared to 11.74 in the placebo group (difference 0.86, 95% CI -1.86, 3.58. Median duration of crying in non-intubated infants was 181 seconds in the tetracaine group compared to 68 seconds in the placebo group (difference -78, 95% CI -539, 117. Local skin erythema was observed transiently in 4 infants (3 in the treatment and 1 in the placebo group. No serious harms were observed. Conclusion Tetracaine 4% when applied for 30 minutes was not beneficial in decreasing procedural pain associated with a PICC in very small infants.

  9. Uncertainty Of Stream Nutrient Transport Estimates Using Random Sampling Of Storm Events From High Resolution Water Quality And Discharge Data

    Science.gov (United States)

    Scholefield, P. A.; Arnscheidt, J.; Jordan, P.; Beven, K.; Heathwaite, L.

    2007-12-01

    The uncertainties associated with stream nutrient transport estimates are frequently overlooked and the sampling strategy is rarely if ever investigated. Indeed, the impact of sampling strategy and estimation method on the bias and precision of stream phosphorus (P) transport calculations is little understood despite the use of such values in the calibration and testing of models of phosphorus transport. The objectives of this research were to investigate the variability and uncertainty in the estimates of total phosphorus transfers at an intensively monitored agricultural catchment. The Oona Water which is located in the Irish border region, is part of a long term monitoring program focusing on water quality. The Oona Water is a rural river catchment with grassland agriculture and scattered dwelling houses and has been monitored for total phosphorus (TP) at 10 min resolution for several years (Jordan et al, 2007). Concurrent sensitive measurements of discharge are also collected. The water quality and discharge data were provided at 1 hour resolution (averaged) and this meant that a robust estimate of the annual flow weighted concentration could be obtained by simple interpolation between points. A two-strata approach (Kronvang and Bruhn, 1996) was used to estimate flow weighted concentrations using randomly sampled storm events from the 400 identified within the time series and also base flow concentrations. Using a random stratified sampling approach for the selection of events, a series ranging from 10 through to the full 400 were used, each time generating a flow weighted mean using a load-discharge relationship identified through log-log regression and monte-carlo simulation. These values were then compared to the observed total phosphorus concentration for the catchment. Analysis of these results show the impact of sampling strategy, the inherent bias in any estimate of phosphorus concentrations and the uncertainty associated with such estimates. The

  10. Global Stratigraphy of Venus: Analysis of a Random Sample of Thirty-Six Test Areas

    Science.gov (United States)

    Basilevsky, Alexander T.; Head, James W., III

    1995-01-01

    The age relations between 36 impact craters with dark paraboloids and other geologic units and structures at these localities have been studied through photogeologic analysis of Magellan SAR images of the surface of Venus. Geologic settings in all 36 sites, about 1000 x 1000 km each, could be characterized using only 10 different terrain units and six types of structures. These units and structures form a major stratigraphic and geologic sequence (from oldest to youngest): (1) tessera terrain; (2) densely fractured terrains associated with coronae and in the form of remnants among plains; (3) fractured and ridged plains and ridge belts; (4) plains with wrinkle ridges; (5) ridges associated with coronae annulae and ridges of arachnoid annulae which are contemporary with wrinkle ridges of the ridged plains; (6) smooth and lobate plains; (7) fractures of coronae annulae, and fractures not related to coronae annulae, which disrupt ridged and smooth plains; (8) rift-associated fractures; and (9) craters with associated dark paraboloids, which represent the youngest 1O% of the Venus impact crater population (Campbell et al.), and are on top of all volcanic and tectonic units except the youngest episodes of rift-associated fracturing and volcanism; surficial streaks and patches are approximately contemporary with dark-paraboloid craters. Mapping of such units and structures in 36 randomly distributed large regions (each approximately 10(exp 6) sq km) shows evidence for a distinctive regional and global stratigraphic and geologic sequence. On the basis of this sequence we have developed a model that illustrates several major themes in the history of Venus. Most of the history of Venus (that of its first 80% or so) is not preserved in the surface geomorphological record. The major deformation associated with tessera formation in the period sometime between 0.5-1.0 b.y. ago (Ivanov and Basilevsky) is the earliest event detected. In the terminal stages of tessera fon

  11. Use of pornography in a random sample of Norwegian heterosexual couples.

    Science.gov (United States)

    Daneback, Kristian; Traeen, Bente; Månsson, Sven-Axel

    2009-10-01

    This study examined the use of pornography in couple relationships to enhance the sex-life. The study contained a representative sample of 398 heterosexual couples aged 22-67 years. Data collection was carried out by self-administered postal questionnaires. The majority (77%) of the couples did not report any kind of pornography use to enhance the sex-life. In 15% of the couples, both had used pornography; in 3% of the couples, only the female partner had used pornography; and, in 5% of the couples, only the male partner had used pornography for this purpose. Based on the results of a discriminant function analysis, it is suggested that couples where one or both used pornography had a more permissive erotic climate compared to the couples who did not use pornography. In couples where only one partner used pornography, we found more problems related to arousal (male) and negative (female) self-perception. These findings could be of importance for clinicians who work with couples.

  12. CSS Need Analysis, Theory and Computation Procedures for the 1977-78 PCS and FAF, Including Sample Cases and Tables.

    Science.gov (United States)

    College Entrance Examination Board, New York, NY. Coll. Scholarship Service.

    The College Scholarship Service (CSS) need analysis system is described in this comprehensive guide. It includes information about the basic rationale, the economic principles, and the computational procedures used in the CSS system. The chapters deal with the following: principles and practices of student financial aid administration; the history…

  13. Control of the positional relationship between a sample collection instrument and a surface to be analyzed during a sampling procedure with image analysis

    Science.gov (United States)

    Van Berkel, Gary J.; Kertesz, Vilmos

    2011-08-09

    A system and method utilizes an image analysis approach for controlling the collection instrument-to-surface distance in a sampling system for use, for example, with mass spectrometric detection. Such an approach involves the capturing of an image of the collection instrument or the shadow thereof cast across the surface and the utilization of line average brightness (LAB) techniques to determine the actual distance between the collection instrument and the surface. The actual distance is subsequently compared to a target distance for re-optimization, as necessary, of the collection instrument-to-surface during an automated surface sampling operation.

  14. A randomized clinical trial comparing cervical dysplasia treatment with cryotherapy vs loop electrosurgical excision procedure in HIV-seropositive women from Johannesburg, South Africa.

    Science.gov (United States)

    Smith, Jennifer S; Sanusi, Busola; Swarts, Avril; Faesen, Mark; Levin, Simon; Goeieman, Bridgette; Ramotshela, Sibongile; Rakhombe, Ntombiyenkosi; Williamson, Anna L; Michelow, Pam; Omar, Tanvier; Hudgens, Michael G; Firnhaber, Cynthia

    2017-08-01

    Mortality associated with cervical cancer is a public health concern for women, particularly in HIV-seropositive women in resource-limited countries. HIV-seropositive women are at a higher risk of high-grade cervical precancer, which can eventually progress to invasive carcinoma as compared to HIV-seronegative women. It is imperative to identify effective treatment methods for high-grade cervical precursors among HIV-seropositive women. Randomized controlled trial data are needed comparing cryotherapy vs loop electrosurgical excision procedure treatment efficacy in HIV-seropositive women. Our primary aim was to compare the difference in the efficacy of loop electrosurgical excision procedure vs cryotherapy for the treatment of high-grade cervical intraepithelial neoplasia (grade ≥2) among HIV-seropositive women by conducting a randomized clinical trial. HIV-seropositive women (n = 166) aged 18-65 years with histology-proven cervical intraepithelial neoplasia grade ≥2 were randomized (1:1) to cryotherapy or loop electrosurgical excision procedure treatment at a government hospital in Johannesburg. Treatment efficacy was compared using 6- and 12-month cumulative incidence posttreatment of: (1) cervical intraepithelial neoplasia grade ≥2; (2) secondary endpoints of histologic cervical intraepithelial neoplasia grade ≥3 and grade ≥1; and (3) high-grade and low-grade cervical cytology. The study was registered (ClinicalTrials.govNCT01723956). From January 2010 through August 2014, 166 participants were randomized (86 loop electrosurgical excision procedure; 80 cryotherapy). Cumulative cervical intraepithelial neoplasia grade ≥2 incidence was higher for cryotherapy (24.3%; 95% confidence interval, 16.1-35.8) than loop electrosurgical excision procedure at 6 months (10.8%; 95% confidence interval, 5.7-19.8) (P = .02), although by 12 months, the difference was not significant (27.2%; 95% confidence interval, 18.5-38.9 vs 18.5%; 95% confidence interval, 11

  15. Estimating screening-mammography receiver operating characteristic (ROC) curves from stratified random samples of screening mammograms: a simulation study.

    Science.gov (United States)

    Zur, Richard M; Pesce, Lorenzo L; Jiang, Yulei

    2015-05-01

    To evaluate stratified random sampling (SRS) of screening mammograms by (1) Breast Imaging Reporting and Data System (BI-RADS) assessment categories, and (2) the presence of breast cancer in mammograms, for estimation of screening-mammography receiver operating characteristic (ROC) curves in retrospective observer studies. We compared observer study case sets constructed by (1) random sampling (RS); (2) SRS with proportional allocation (SRS-P) with BI-RADS 1 and 2 noncancer cases accounting for 90.6% of all noncancer cases; (3) SRS with disproportional allocation (SRS-D) with BI-RADS 1 and 2 noncancer cases accounting for 10%-80%; and (4) SRS-D and multiple imputation (SRS-D + MI) with missing BI-RADS 1 and 2 noncancer cases imputed to recover the 90.6% proportion. Monte Carlo simulated case sets were drawn from a large case population modeled after published Digital Mammography Imaging Screening Trial data. We compared the bias, root-mean-square error, and coverage of 95% confidence intervals of area under the ROC curve (AUC) estimates from the sampling methods (200-2000 cases, of which 25% were cancer cases) versus from the large case population. AUC estimates were unbiased from RS, SRS-P, and SRS-D + MI, but biased from SRS-D. AUC estimates from SRS-P and SRS-D + MI had 10% smaller root-mean-square error than RS. Both SRS-P and SRS-D + MI can be used to obtain unbiased and 10% more efficient estimate of screening-mammography ROC curves. Copyright © 2015 AUR. Published by Elsevier Inc. All rights reserved.

  16. Assessment of the Worldwide Antimalarial Resistance Network Standardized Procedure for In Vitro Malaria Drug Sensitivity Testing Using SYBR Green Assay for Field Samples with Various Initial Parasitemia Levels.

    Science.gov (United States)

    Cheruiyot, Agnes C; Auschwitz, Jennifer M; Lee, Patricia J; Yeda, Redemptah A; Okello, Charles O; Leed, Susan E; Talwar, Mayank; Murthy, Tushar; Gaona, Heather W; Hickman, Mark R; Akala, Hoseah M; Kamau, Edwin; Johnson, Jacob D

    2016-04-01

    The malaria SYBR green assay, which is used to profilein vitrodrug susceptibility ofPlasmodium falciparum, is a reliable drug screening and surveillance tool. Malaria field surveillance efforts provide isolates with various low levels of parasitemia. To be advantageous, malaria drug sensitivity assays should perform reproducibly among various starting parasitemia levels rather than at one fixed initial value. We examined the SYBR green assay standardized procedure developed by the Worldwide Antimalarial Resistance Network (WWARN) for its sensitivity and ability to accurately determine the drug concentration that inhibits parasite growth by 50% (IC50) in samples with a range of initial parasitemia levels. The initial sensitivity determination of the WWARN procedure yielded a detection limit of 0.019% parasitemia.P. falciparumlaboratory strains and field isolates with various levels of initial parasitemia were then subjected to a range of doses of common antimalarials. The IC50s were comparable for laboratory strains with between 0.0375% and 0.6% parasitemia and for field isolates with between 0.075% and 0.6% parasitemia for all drugs tested. Furthermore, assay quality (Z') analysis indicated that the WWARN procedure displays high robustness, allowing for drug testing of malaria field samples within the derived range of initial parasitemia. The use of the WWARN procedure should allow for the inclusion of more malaria field samples in malaria drug sensitivity screens that would have otherwise been excluded due to low initial parasitemia levels. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  17. The Effect of Listening to Music During Percutaneous Nephrostomy Tube Placement on Pain, Anxiety, and Success Rate of Procedure: A Randomized Prospective Study.

    Science.gov (United States)

    Hamidi, Nurullah; Ozturk, Erdem

    2017-05-01

    To evaluate the effect of listening to music on pain, anxiety, and success of procedure during office-based percutaneous nephrostomy tube placement (PNTP). One hundred consecutive patients (age >18 years) with hydronephrosis were prospectively enrolled in this study. All patients were prospectively randomized to undergo office-based PNTP with (Group I, n = 50) or without music (Group II, n = 50). Anxiety levels were evaluated with State Trait Anxiety Inventory. A visual analog scale was used to evaluate pain levels, patient's satisfaction, and willingness to undergo the procedure. We also compared success rates of procedures. The mean age, duration of procedure, and gender distribution were statistically similar between the two groups. The mean postprocedural heart rates and systolic blood pressures in Group I patients were significantly lower than Group II patients (p = 0.01 and p = 0.028, respectively), whereas preprocedural pulse rate and systolic blood pressure were similar. The mean anxiety level and mean pain score of Group I were significantly lower than those of Group II (p = 0.008 and p music during office-based PNTP decreases anxiety or pain and increases success rate of procedure. As an alternative to sedation or general anesthesia, music is easily accessible without side effect and cost.

  18. Control of the positional relationship between a sample collection instrument and a surface to be analyzed during a sampling procedure using a laser sensor

    Science.gov (United States)

    Van Berkel, Gary J [Clinton, TN; Kertesz, Vilmos [Knoxville, TN

    2012-02-21

    A system and method utilizes distance-measuring equipment including a laser sensor for controlling the collection instrument-to-surface distance during a sample collection process for use, for example, with mass spectrometric detection. The laser sensor is arranged in a fixed positional relationship with the collection instrument, and a signal is generated by way of the laser sensor which corresponds to the actual distance between the laser sensor and the surface. The actual distance between the laser sensor and the surface is compared to a target distance between the laser sensor and the surface when the collection instrument is arranged at a desired distance from the surface for sample collecting purposes, and adjustments are made, if necessary, so that the actual distance approaches the target distance.

  19. Comparison study of two different procedures for the determination of drugs of abuse in postmortem brain samples

    DEFF Research Database (Denmark)

    Holm, Karen Marie Dollerup; Reiter, Birgit; Skov, Louise

    2014-01-01

    The aim of this study was to compare two routine solid phase extraction methods for the analysis of body-fluids and tissue samples; a routine method developed in Vienna for tissue samples compared to a routine method developed in Copenhagen for blood. Our approach was to simply exchange the matri......, diazepam and 7-aminoflunitrazepam) in 19 brain homogenates of authentic cases were conducted....

  20. Randomized Comparison of Two Vaginal Self-Sampling Methods for Human Papillomavirus Detection: Dry Swab versus FTA Cartridge.

    Directory of Open Access Journals (Sweden)

    Rosa Catarino

    Full Text Available Human papillomavirus (HPV self-sampling (self-HPV is valuable in cervical cancer screening. HPV testing is usually performed on physician-collected cervical smears stored in liquid-based medium. Dry filters and swabs are an alternative. We evaluated the adequacy of self-HPV using two dry storage and transport devices, the FTA cartridge and swab.A total of 130 women performed two consecutive self-HPV samples. Randomization determined which of the two tests was performed first: self-HPV using dry swabs (s-DRY or vaginal specimen collection using a cytobrush applied to an FTA cartridge (s-FTA. After self-HPV, a physician collected a cervical sample using liquid-based medium (Dr-WET. HPV types were identified by real-time PCR. Agreement between collection methods was measured using the kappa statistic.HPV prevalence for high-risk types was 62.3% (95%CI: 53.7-70.2 detected by s-DRY, 56.2% (95%CI: 47.6-64.4 by Dr-WET, and 54.6% (95%CI: 46.1-62.9 by s-FTA. There was overall agreement of 70.8% between s-FTA and s-DRY samples (kappa = 0.34, and of 82.3% between self-HPV and Dr-WET samples (kappa = 0.56. Detection sensitivities for low-grade squamous intraepithelial lesion or worse (LSIL+ were: 64.0% (95%CI: 44.5-79.8 for s-FTA, 84.6% (95%CI: 66.5-93.9 for s-DRY, and 76.9% (95%CI: 58.0-89.0 for Dr-WET. The preferred self-collection method among patients was s-DRY (40.8% vs. 15.4%. Regarding costs, FTA card was five times more expensive than the swab (~5 US dollars (USD/per card vs. ~1 USD/per swab.Self-HPV using dry swabs is sensitive for detecting LSIL+ and less expensive than s-FTA.International Standard Randomized Controlled Trial Number (ISRCTN: 43310942.

  1. Randomized, Double-Blind, Placebo-Controlled Study on Decolonization Procedures for Methicillin-Resistant Staphylococcus aureus (MRSA) among HIV-Infected Adults.

    Science.gov (United States)

    Weintrob, Amy; Bebu, Ionut; Agan, Brian; Diem, Alona; Johnson, Erica; Lalani, Tahaniyat; Wang, Xun; Bavaro, Mary; Ellis, Michael; Mende, Katrin; Crum-Cianflone, Nancy

    2015-01-01

    HIV-infected persons have increased risk of MRSA colonization and skin and soft-tissue infections (SSTI). However, no large clinical trial has examined the utility of decolonization procedures in reducing MRSA colonization or infection among community-dwelling HIV-infected persons. 550 HIV-infected adults at four geographically diverse US military HIV clinics were prospectively screened for MRSA colonization at five body locations every 6 months during a 2-year period. Those colonized were randomized in a double-blind fashion to nasal mupirocin (Bactroban) twice daily and hexachlorophene (pHisoHex) soaps daily for 7 days compared to placeboes similar in appearance but without specific antibacterial activity. The primary endpoint was MRSA colonization at 6-months post-randomization; secondary endpoints were time to MRSA clearance, subsequent MRSA infections/SSTI, and predictors for MRSA clearance at the 6-month time point. Forty-nine (9%) HIV-infected persons were MRSA colonized and randomized. Among those with 6-month colonization data (80% of those randomized), 67% were negative for MRSA colonization in both groups (p = 1.0). Analyses accounting for missing 6-month data showed no significant differences could have been achieved. In the multivariate adjusted models, randomization group was not associated with 6-month MRSA clearance. The median time to MRSA clearance was similar in the treatment vs. placebo groups (1.4 vs. 1.8 months, p = 0.35). There was no difference on subsequent development of MRSA infections/SSTI (p = 0.89). In a multivariable model, treatment group, demographics, and HIV-specific factors were not predictive of MRSA clearance at the 6-month time point. A one-week decolonization procedure had no effect on MRSA colonization at the 6-month time point or subsequent infection rates among community-dwelling HIV-infected persons. More aggressive or novel interventions may be needed to reduce the burden of MRSA in this population. Clinical

  2. Duodenum-preserving pancreatic head resection: 10-year follow-up of a randomized controlled trial comparing the Beger procedure with the Berne modification.

    Science.gov (United States)

    Klaiber, Ulla; Alldinger, Ingo; Probst, Pascal; Bruckner, Thomas; Contin, Pietro; Köninger, Jörg; Hackert, Thilo; Büchler, Markus W; Diener, Markus K

    2016-07-01

    Since the introduction of the duodenum-preserving pancreatic head resection for operative treatment of chronic pancreatitis, various modifications of the original Beger procedure have emerged. A randomized controlled trial comparing the Beger procedure and the Berne modification indicated that the latter is an equivalent alternative, but a comparison of the long-term results of both procedures has not yet been published. Between December 2002 and January 2005, 65 patients were randomized intraoperatively to the Beger or the Berne procedure. For this 10-year follow-up, patients were contacted by phone and in writing to evaluate patient-relevant outcome parameters. Statistical analysis was made on an intention-to-treat basis. Median follow-up was 129 (111-137) months. Forty of 65 patients were available for follow-up; 11 of the original study cohort had died, and 14 were otherwise lost to follow-up. Quality of life, pain, occupational disability, exocrine and endocrine pancreatic function, endoscopic interventions, and redo operations were comparable in both groups. More than half of the patients were completely free of pain, and the majority in both groups judged that the index operation had improved their quality of life. Ten-year follow-up showed no differences in patient-relevant outcome parameters between the Beger and Berne procedures for treatment of chronic pancreatitis. Because short-term results have shown the Berne modification is superior in terms of operation time and duration of hospital stay, it should be preferred whenever possible, depending on the individual surgeon's expertise and the intraoperative findings. Copyright © 2016 Elsevier Inc. All rights reserved.

  3. Comparison of sampling procedures and microbiological and non-microbiological parameters to evaluate cleaning and disinfection in broiler houses.

    Science.gov (United States)

    Luyckx, K; Dewulf, J; Van Weyenberg, S; Herman, L; Zoons, J; Vervaet, E; Heyndrickx, M; De Reu, K

    2015-04-01

    Cleaning and disinfection of the broiler stable environment is an essential part of farm hygiene management. Adequate cleaning and disinfection is essential for prevention and control of animal diseases and zoonoses. The goal of this study was to shed light on the dynamics of microbiological and non-microbiological parameters during the successive steps of cleaning and disinfection and to select the most suitable sampling methods and parameters to evaluate cleaning and disinfection in broiler houses. The effectiveness of cleaning and disinfection protocols was measured in six broiler houses on two farms through visual inspection, adenosine triphosphate hygiene monitoring and microbiological analyses. Samples were taken at three time points: 1) before cleaning, 2) after cleaning, and 3) after disinfection. Before cleaning and after disinfection, air samples were taken in addition to agar contact plates and swab samples taken from various sampling points for enumeration of total aerobic flora, Enterococcus spp., and Escherichia coli and the detection of E. coli and Salmonella. After cleaning, air samples, swab samples, and adenosine triphosphate swabs were taken and a visual score was also assigned for each sampling point. The mean total aerobic flora determined by swab samples decreased from 7.7±1.4 to 5.7±1.2 log CFU/625 cm2 after cleaning and to 4.2±1.6 log CFU/625 cm2 after disinfection. Agar contact plates were used as the standard for evaluating cleaning and disinfection, but in this study they were found to be less suitable than swabs for enumeration. In addition to measuring total aerobic flora, Enterococcus spp. seemed to be a better hygiene indicator to evaluate cleaning and disinfection protocols than E. coli. All stables were Salmonella negative, but the detection of its indicator organism E. coli provided additional information for evaluating cleaning and disinfection protocols. Adenosine triphosphate analyses gave additional information about the

  4. Optimal Subset Selection of Time-Series MODIS Images and Sample Data Transfer with Random Forests for Supervised Classification Modelling

    Directory of Open Access Journals (Sweden)

    Fuqun Zhou

    2016-10-01

    Full Text Available Nowadays, various time-series Earth Observation data with multiple bands are freely available, such as Moderate Resolution Imaging Spectroradiometer (MODIS datasets including 8-day composites from NASA, and 10-day composites from the Canada Centre for Remote Sensing (CCRS. It is challenging to efficiently use these time-series MODIS datasets for long-term environmental monitoring due to their vast volume and information redundancy. This challenge will be greater when Sentinel 2–3 data become available. Another challenge that researchers face is the lack of in-situ data for supervised modelling, especially for time-series data analysis. In this study, we attempt to tackle the two important issues with a case study of land cover mapping using CCRS 10-day MODIS composites with the help of Random Forests’ features: variable importance, outlier identification. The variable importance feature is used to analyze and select optimal subsets of time-series MODIS imagery for efficient land cover mapping, and the outlier identification feature is utilized for transferring sample data available from one year to an adjacent year for supervised classification modelling. The results of the case study of agricultural land cover classification at a regional scale show that using only about a half of the variables we can achieve land cover classification accuracy close to that generated using the full dataset. The proposed simple but effective solution of sample transferring could make supervised modelling possible for applications lacking sample data.

  5. Optimal Subset Selection of Time-Series MODIS Images and Sample Data Transfer with Random Forests for Supervised Classification Modelling.

    Science.gov (United States)

    Zhou, Fuqun; Zhang, Aining

    2016-10-25

    Nowadays, various time-series Earth Observation data with multiple bands are freely available, such as Moderate Resolution Imaging Spectroradiometer (MODIS) datasets including 8-day composites from NASA, and 10-day composites from the Canada Centre for Remote Sensing (CCRS). It is challenging to efficiently use these time-series MODIS datasets for long-term environmental monitoring due to their vast volume and information redundancy. This challenge will be greater when Sentinel 2-3 data become available. Another challenge that researchers face is the lack of in-situ data for supervised modelling, especially for time-series data analysis. In this study, we attempt to tackle the two important issues with a case study of land cover mapping using CCRS 10-day MODIS composites with the help of Random Forests' features: variable importance, outlier identification. The variable importance feature is used to analyze and select optimal subsets of time-series MODIS imagery for efficient land cover mapping, and the outlier identification feature is utilized for transferring sample data available from one year to an adjacent year for supervised classification modelling. The results of the case study of agricultural land cover classification at a regional scale show that using only about a half of the variables we can achieve land cover classification accuracy close to that generated using the full dataset. The proposed simple but effective solution of sample transferring could make supervised modelling possible for applications lacking sample data.

  6. Optimisation of focused-microwave assisted digestion procedure for Kjeldahl nitrogen determination in bean samples by factorial design and Doehlert design.

    Science.gov (United States)

    Korn, Maria das Graças A; Dos Santos, Wagna P C; Korn, Mauro; Ferreira, Sérgio L C

    2005-02-15

    In the present paper a focused-microwave Kjeldahl digestion procedure without metal catalyst for nitrogen determination in bean samples was developed. Temperature at which the decomposition plateau occurs, mass of potassium sulphate and either volume of sulphuric acid or hydrogen peroxide were optimised. Results of the two-level full factorial design (2(4)) based on an analysis of variance demonstrated that only the decomposition plateau temperature and the sulphuric acid volume were statistically significant. Optimal conditions for the digestion of bean samples were obtained by using Doehlert design. The modified digestion procedure of 0.25g of bean samples has been performed in 27min at optimised conditions. The accuracy of the developed procedure by the analysis of the two certified reference materials, peach leaves (NIST 1547) and apple leaves (NIST 1515). The t-test applied to the results revealed that they are in agreement (p > 0.05) with the certified values. The precision, expressed as relative standard deviation (R.S.D.) was of 0.96% for four successive Kjeldahl nitrogen determinations. In addition, interlaboratory exercises were performed with several bean samples in reference Brazilian food control laboratory.

  7. Media Use and Source Trust among Muslims in Seven Countries: Results of a Large Random Sample Survey

    Directory of Open Access Journals (Sweden)

    Steven R. Corman

    2013-12-01

    Full Text Available Despite the perceived importance of media in the spread of and resistance against Islamist extremism, little is known about how Muslims use different kinds of media to get information about religious issues, and what sources they trust when doing so. This paper reports the results of a large, random sample survey among Muslims in seven countries Southeast Asia, West Africa and Western Europe, which helps fill this gap. Results show a diverse set of profiles of media use and source trust that differ by country, with overall low trust in mediated sources of information. Based on these findings, we conclude that mass media is still the most common source of religious information for Muslims, but that trust in mediated information is low overall. This suggests that media are probably best used to persuade opinion leaders, who will then carry anti-extremist messages through more personal means.

  8. Enhancing positive parent-child interactions and family functioning in a poverty sample: a randomized control trial.

    Science.gov (United States)

    Negrão, Mariana; Pereira, Mariana; Soares, Isabel; Mesman, Judi

    2014-01-01

    This study tested the attachment-based intervention program Video-feedback Intervention to promote Positive Parenting and Sensitive Discipline (VIPP-SD) in a randomized controlled trial with poor families of toddlers screened for professional's concerns about the child's caregiving environment. The VIPP-SD is an evidence-based intervention, but has not yet been tested in the context of poverty. The sample included 43 families with 1- to 4-year-old children: mean age at the pretest was 29 months and 51% were boys. At the pretest and posttest, mother-child interactions were observed at home, and mothers reported on family functioning. The VIPP-SD proved to be effective in enhancing positive parent-child interactions and positive family relations in a severely deprived context. Results are discussed in terms of implications for support services provided to such poor families in order to reduce intergenerational risk transmission.

  9. Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples.

    Science.gov (United States)

    Sulej, Anna Maria; Polkowska, Żaneta; Astel, Aleksander; Namieśnik, Jacek

    2013-12-15

    The purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination of PAHs, benzotriazoles and glycols is sample preparation stage, due to diverse matrix composition, the possibility of interference associated with the presence of components with similar physicochemical properties. In this study, five different versions of sample preparation using extraction techniques, such as: LLE and SPE, were tested. In all examined runoff water samples collected from the airports, the presence of PAH compounds and glycols was observed. In majority of the samples, BT compounds were determined. Runoff water samples collected from the areas of Polish and British international airports as well as local airports had similar qualitative composition, but quantitative composition of the analytes was very diverse. New and validated analytical methodologies ensure that the necessary information for assessing the negative impact of airport activities on the environment can be obtained. © 2013 Elsevier B.V. All rights reserved.

  10. Rationale, Design, Samples, and Baseline Sun Protection in a Randomized Trial on a Skin Cancer Prevention Intervention in Resort Environments

    Science.gov (United States)

    Buller, David B.; Andersen, Peter A.; Walkosz, Barbara J.; Scott, Michael D.; Beck, Larry; Cutter, Gary R.

    2016-01-01

    Introduction Exposure to solar ultraviolet radiation during recreation is a risk factor for skin cancer. A trial evaluating an intervention to promote advanced sun protection (sunscreen pre-application/reapplication; protective hats and clothing; use of shade) during vacations. Materials and Methods Adult visitors to hotels/resorts with outdoor recreation (i.e., vacationers) participated in a group-randomized pretest-posttest controlled quasi-experimental design in 2012–14. Hotels/resorts were pair-matched and randomly assigned to the intervention or untreated control group. Sun protection (e.g., clothing, hats, shade and sunscreen) was measured in cross-sectional samples by observation and a face-to-face intercept survey during two-day visits. Results Initially, 41 hotel/resorts (11%) participated but 4 dropped out before posttest. Hotel/resorts were diverse (employees=30 to 900; latitude=24o 78′ N to 50o 52′ N; elevation=2 ft. to 9,726 ft. above sea level), and had a variety of outdoor venues (beaches/pools, court/lawn games, golf courses, common areas, and chairlifts). At pretest, 4,347 vacationers were observed and 3,531 surveyed. More females were surveyed (61%) than observed (50%). Vacationers were mostly 35–60 years old, highly educated (college education = 68%) and non-Hispanic white (93%), with high-risk skin types (22%). Vacationers reported covering 60% of their skin with clothing. Also, 40% of vacationers used shade; 60% applied sunscreen; and 42% had been sunburned. Conclusions The trial faced challenges recruiting resorts but result show that the large, multi-state sample of vacationers were at high risk for solar UV exposure. PMID:26593781

  11. Investigating causal associations between use of nicotine, alcohol, caffeine, and cannabis: A two-sample bidirectional Mendelian randomization study.

    Science.gov (United States)

    Verweij, Karin J H; Treur, Jorien L; Vink, Jacqueline M

    2018-01-15

    Epidemiological studies consistently show co-occurrence of use of different addictive substances. Whether these associations are causal or due to overlapping underlying influences remains an important question in addiction research. Methodological advances have made it possible to use published genetic associations to infer causal relationships between phenotypes. In this exploratory study, we used Mendelian randomization (MR) to examine the causality of well-established associations between nicotine, alcohol, caffeine, and cannabis use. Two-sample MR was employed to estimate bi-directional causal effects between four addictive substances: nicotine (smoking initiation and cigarettes smoked per day), caffeine (cups of coffee per day), alcohol (units per week), and cannabis (initiation). Based on existing genome-wide association results we selected genetic variants associated with the exposure measure as an instrument to estimate causal effects. Where possible we applied sensitivity analyses (MR-Egger and weighted median) more robust to horizontal pleiotropy. Most MR tests did not reveal causal associations. There was some weak evidence for a causal positive effect of genetically instrumented alcohol use on smoking initiation and of cigarettes per day on caffeine use, but these did not hold up with the sensitivity analyses. There was also some suggestive evidence for a positive effect of alcohol use on caffeine use (only with MR-Egger) and smoking initiation on cannabis initiation (only with weighted median). None of the suggestive causal associations survived corrections for multiple testing. Two-sample Mendelian randomization analyses found little evidence for causal relationships between nicotine, alcohol, caffeine, and cannabis use. This article is protected by copyright. All rights reserved.

  12. Angioseal versus manual compression for haemostasis following peripheral vascular diagnostic and interventional procedures-A randomized controlled trial

    Energy Technology Data Exchange (ETDEWEB)

    Upponi, S.S. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom); Ganeshan, A.G. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom); Warakaulle, D.R. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom); Phillips-Hughes, J. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom); Boardman, P. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom); Uberoi, R. [Department of Clinical Radiology, John Radcliffe Hospital, Headley Way, Headington, Oxford OX3 9DZ (United Kingdom)]. E-mail: Raman.Uberoi@orh.nhs.uk

    2007-02-15

    The aim of this study was to compare the angioseal device to manual compression for femoral artery puncture following peripheral vascular procedures, in the context of day case vascular procedures. One hundred patients were prospectively randomised to haemostasis using the angioseal device or manual compression following arterial puncture for peripheral vascular diagnostic or intervention procedures. Data were collected regarding time to haemostasis and complications immediately post-procedure, at 1 h, 2 h and at 1 week. There were 50 patients in each group. There were no significant differences in demographic variables, or in complication rates immediately, at 1 h, 2 h and at 1 week (Chi-squared). The only significant difference between the two groups was time to haemostasis. The mean time to haemostasis in the compression group was 10.6 min and 2.0 min in the angioseal group (t-test p < 0.0001). In conclusion, no significant differences in complications were found between manual compression and angioseal. However, there was a significant difference in time to haemostasis.

  13. What's in a name? The challenge of describing interventions in systematic reviews: analysis of a random sample of reviews of non-pharmacological stroke interventions.

    Science.gov (United States)

    Hoffmann, Tammy C; Walker, Marion F; Langhorne, Peter; Eames, Sally; Thomas, Emma; Glasziou, Paul

    2015-11-17

    To assess, in a sample of systematic reviews of non-pharmacological interventions, the completeness of intervention reporting, identify the most frequently missing elements, and assess review authors' use of and beliefs about providing intervention information. Analysis of a random sample of systematic reviews of non-pharmacological stroke interventions; online survey of review authors. The Cochrane Library and PubMed were searched for potentially eligible systematic reviews and a random sample of these assessed for eligibility until 60 (30 Cochrane, 30 non-Cochrane) eligible reviews were identified. In each review, the completeness of the intervention description in each eligible trial (n=568) was assessed by 2 independent raters using the Template for Intervention Description and Replication (TIDieR) checklist. All review authors (n=46) were invited to complete a survey. Most reviews were missing intervention information for the majority of items. The most incompletely described items were: modifications, fidelity, materials, procedure and tailoring (missing from all interventions in 97%, 90%, 88%, 83% and 83% of reviews, respectively). Items that scored better, but were still incomplete for the majority of reviews, were: 'when and how much' (in 31% of reviews, adequate for all trials; in 57% of reviews, adequate for some trials); intervention mode (in 22% of reviews, adequate for all trials; in 38%, adequate for some trials); and location (in 19% of reviews, adequate for all trials). Of the 33 (71%) authors who responded, 58% reported having further intervention information but not including it, and 70% tried to obtain information. Most focus on intervention reporting has been directed at trials. Poor intervention reporting in stroke systematic reviews is prevalent, compounded by poor trial reporting. Without adequate intervention descriptions, the conduct, usability and interpretation of reviews are restricted and therefore, require action by trialists

  14. Development of a simple desulfurization procedure for the determination of butyltins in complex sediment samples using gas chromatography-pulsed flame photometric detection.

    Science.gov (United States)

    Bravo, M; Valenzuela, A; Quiroz, W; Pinto, M; Flores, M; Pinochet, H

    2010-05-15

    In this study a rapid solid phase extraction (SPE) procedure was developed to minimize the effect of different sulfur species for the determination of butyltin in sediments. The organosulfur species and organotins were firstly retained on C8 cartridges and then organotins were selectively eluted and analyzed by gas chromatography-pulsed flame photometric detection (GC-PFPD). Optimal conditions for the SPE procedure were obtained using an experimental design approach. The method's accuracy was established by analyzing a certified reference material (CRM), BCR-646 freshwater sediment. The experimental values were found to be in agreement with the assigned values for butyltins. Finally, complex sediment samples collected from a Chilean harbor were analyzed using this methodology to demonstrate its analytical potential for the determination of butyltin in environmental samples.

  15. U.S. Geological Survey Noble Gas Laboratory’s standard operating procedures for the measurement of dissolved gas in water samples

    Science.gov (United States)

    Hunt, Andrew G.

    2015-08-12

    This report addresses the standard operating procedures used by the U.S. Geological Survey’s Noble Gas Laboratory in Denver, Colorado, U.S.A., for the measurement of dissolved gases (methane, nitrogen, oxygen, and carbon dioxide) and noble gas isotopes (helium-3, helium-4, neon-20, neon-21, neon-22, argon-36, argon-38, argon-40, kryton-84, krypton-86, xenon-103, and xenon-132) dissolved in water. A synopsis of the instrumentation used, procedures followed, calibration practices, standards used, and a quality assurance and quality control program is presented. The report outlines the day-to-day operation of the Residual Gas Analyzer Model 200, Mass Analyzer Products Model 215–50, and ultralow vacuum extraction line along with the sample handling procedures, noble gas extraction and purification, instrument measurement procedures, instrumental data acquisition, and calculations for the conversion of raw data from the mass spectrometer into noble gas concentrations per unit mass of water analyzed. Techniques for the preparation of artificial dissolved gas standards are detailed and coupled to a quality assurance and quality control program to present the accuracy of the procedures used in the laboratory.

  16. Standardization and optimization of core sampling procedure for carbon isotope analysis in eucalyptus and variation in carbon isotope ratios across species and growth conditions

    CSIR Research Space (South Africa)

    Raju, M

    2011-11-01

    Full Text Available and optimization of core sampling procedure for carbon isotope analysis in eucalyptus and variation in carbon isotope ratios across species and growth conditions Mohan Raju, B#; Nuveshen Naidoo*; Sheshshaayee, M. S; Verryn, S. D*; Kamalkannan, R^; Bindumadhava... isotope analysis in Eucalyptus. Methods Expt 1: * Cores were taken from periphery to pith in 5 year old trees of Eucalyptus * Five half sib families of Eucalyptus grandis & E. urophylla were used ? Cores were further subdivided into 5 fragments...

  17. Optimisation of focused-microwave assisted digestion procedure for Kjeldahl nitrogen determination in bean samples by factorial design and Doehlert design

    OpenAIRE

    Korn, Maria das Graças Andrade; Santos, Wagna P. C. dos; Korn, Mauro; Ferreira, Sergio Luis Costa

    2005-01-01

    Trabalho completo: acesso restrito, p. 710–715 In the present paper a focused-microwave Kjeldahl digestion procedure without metal catalyst for nitrogen determination in bean samples was developed. Temperature at which the decomposition plateau occurs, mass of potassium sulphate and either volume of sulphuric acid or hydrogen peroxide were optimised. Results of the two-level full factorial design (24) based on an analysis of variance demonstrated that only the decomposition plateau tempera...

  18. Study of extraction procedures for protein analysis in plankton samples by OFFGEL electrophoresis hyphenated with Lab-on-a-chip technology.

    Science.gov (United States)

    García-Otero, Natalia; Barciela-Alonso, Ma Carmen; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2013-10-15

    Extraction procedures for protein analysis from plankton samples were studied. OFFGEL electrophoresis combined with Lab-on-a-chip technology has been applied for protein analysis in plankton samples. BCR-414 (plankton) certified reference material from the European Commission was used to evaluate the protein extraction procedures. Three protein extraction procedures were studied: (1) by using Tris-HCl buffer containing a protease inhibitor cocktail, (2) urea/triton X-100 buffer extraction, and (3) using the phenol/sodium dodecyl sulphate method after different washing steps with 10% trichloroacetic acid/acetone solution and methanol. The pellet of proteins obtained was dried and then dissolved in the OFFGEL buffer. Proteins were separated according to their isoelectric points by OFFGEL electrophoresis. This separation was performed using 24 cm, pH 3-10 IPG Dry Strips. The proteins present in each liquid fraction (24 fractions) were separated according to their molecular weight using a microfluidic Lab-on-a-chip electrophoresis with the Protein 80 LabChip kit. This kit allows for the separation of proteins with a molecular weight ranging from 5 to 80 kDa. Taking into account the intensity and the number of the protein bands obtained, the protein extraction procedure using the phenol/sodium dodecyl sulphate after different wash steps with 10% trichloroacetic acid/acetone solution was selected. The developed method was applied for protein determination in a fresh marine plankton sample. The proteins found in this sample have a molecular weight ranging from 6.4 to 57.3 kDa, and the proteins with highest molecular weight were in the OFFGEL fractions with an isoelectric point ranging from 4.40 to 8.60. The concentration of proteins were calculated using external calibration with Bovine Serum Albumin, and the protein concentrations varied from 50.0 to 925.9 ng µL(-1). Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Development of a new sample pre-treatment procedure based on pressurized liquid extraction for the determination of metals in edible seaweed.

    Science.gov (United States)

    Moreda-Piñeiro, Jorge; Alonso-Rodríguez, Elia; López-Mahía, Purificación; Muniategui-Lorenzo, Soledad; Prada-Rodríguez, Darío; Moreda-Piñeiro, Antonio; Bermejo-Barrera, Pilar

    2007-08-13

    A new, simple, fast and automated method based on acetic acid-pressurized liquid extraction (PLE) has been developed for the simultaneous extraction of major and trace elements (As, Ca, Cd, Co, Cr, K, Mg, Mn, Na, Pb, Sr and Zn) from edible seaweeds. The target elements have been simultaneously determined by inductively coupled plasma-optical emission spectrometry (ICP-OES). The influence of several extraction parameters (e.g. acetic acid concentration, extraction temperature, extraction time, pressure, number of cycles, particle size and diatomaceous earth (DE) mass/sample mass ratio) on the efficiency of metal leaching has been evaluated. The results showed that metal extraction efficiency depends on the mass ratio of the dispersing agent mass and the sample. The optimized procedure consisted of the following conditions: acetic acid (0.75 M) as an extracting solution, 5 min of extraction time, one extraction cycle at room temperature at a pressure of 10.3 MPa and addition of a dispersing agent (at a ratio of 5:1 over the sample mass). The leaching procedure was completed after 7 min (5 min extraction time plus 1 min purge time plus 1 min end relief time). Limits of detection and quantification and repeatability of the over all procedure have been assessed. Method validation was performed analysing two seaweed reference materials (NIES-03 Chlorella Kessleri and NIES-09 Sargasso). The developed extraction method has been applied to red (Dulse and Nori), green (Sea Lettuce) and brown (Kombu, Wakame and Sea Spaghetti) edible seaweeds.

  20. Air sampling procedures to evaluate microbial contamination: a comparison between active and passive methods in operating theatres

    Directory of Open Access Journals (Sweden)

    Napoli Christian

    2012-08-01

    Full Text Available Abstract Background Since air can play a central role as a reservoir for microorganisms, in controlled environments such as operating theatres regular microbial monitoring is useful to measure air quality and identify critical situations. The aim of this study is to assess microbial contamination levels in operating theatres using both an active and a passive sampling method and then to assess if there is a correlation between the results of the two different sampling methods. Methods The study was performed in 32 turbulent air flow operating theatres of a University Hospital in Southern Italy. Active sampling was carried out using the Surface Air System and passive sampling with settle plates, in accordance with ISO 14698. The Total Viable Count (TVC was evaluated at rest (in the morning before the beginning of surgical activity and in operational (during surgery. Results The mean TVC at rest was 12.4 CFU/m3 and 722.5 CFU/m2/h for active and passive samplings respectively. The mean in operational TVC was 93.8 CFU/m3 (SD = 52.69; range = 22-256 and 10496.5 CFU/m2/h (SD = 7460.5; range = 1415.5-25479.7 for active and passive samplings respectively. Statistical analysis confirmed that the two methods correlate in a comparable way with the quality of air. Conclusion It is possible to conclude that both methods can be used for general monitoring of air contamination, such as routine surveillance programs. However, the choice must be made between one or the other to obtain specific information.

  1. A headspace solid-phase microextraction procedure coupled with gas chromatography-mass spectrometry for the analysis of volatile polycyclic aromatic hydrocarbons in milk samples

    Energy Technology Data Exchange (ETDEWEB)

    Aguinaga, N.; Campillo, N.; Vinas, P.; Hernandez-Cordoba, M. [University of Murcia, Department of Analytical Chemistry, Faculty of Chemistry, Murcia (Spain)

    2008-06-15

    A sensitive and solvent-free method for the determination of ten polycyclic aromatic hydrocarbons, namely, naphthalene, acenaphthylene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benzo[a]anthracene and chrysene, with up to four aromatic rings, in milk samples using headspace solid-phase microextraction and gas chromatography-mass spectrometry detection has been developed. A polydimethylsiloxane-divinylbenzene fiber was chosen and used at 75 C for 60 min. Detection limits ranging from 0.2 to 5 ng L{sup -1} were attained at a signal-to-noise ratio of 3, depending on the compound and the milk sample under analysis. The proposed method was applied to ten different milk samples and the presence of six of the analytes studied in a skimmed milk with vegetal fiber sample was confirmed. The reliability of the procedure was verified by analyzing two different certified reference materials and by recovery studies. (orig.)

  2. Limited Impact of Music Therapy on Patient Anxiety with the Large Loop Excision of Transformation Zone Procedure - a Randomized Controlled Trial.

    Science.gov (United States)

    Kongsawatvorakul, Chompunoot; Charakorn, Chuenkamon; Paiwattananupant, Krissada; Lekskul, Navamol; Rattanasiri, Sasivimol; Lertkhachonsuk, Arb-Aroon

    2016-01-01

    Many studies have pointed to strategies to cope with patient anxiety in colposcopy. Evidence shows that patients experienced considerable distress with the large loop excision of transformation zone (LLETZ) procedure and suitable interventions should be introduced to reduce anxiety. This study aimed to investigate the effects of music therapy in patients undergoing LLETZ. A randomized controlled trial was conducted with patients undergoing LLETZ performed under local anesthesia in an out patient setting at Ramathibodi Hospital, Bangkok, Thailand, from February 2015 to January 2016. After informed consent and demographic data were obtained, we assessed the anxiety level using State Anxiety Inventory pre and post procedures. Music group patients listened to classical songs through headphones, while the control group received the standard care. Pain score was evaluated with a visual analog scale (VAS). Statistical analysis was conducted using Pearson Chi-square, Fisher's Exact test and T-Test and p-values less than 0.05 were considered statistically significant. A total of 73 patients were enrolled and randomized, resulting in 36 women in the music group and 37 women in the non-music control group. The preoperative mean anxiety score was higher in the music group (46.8 VS 45.8 points). The postoperative mean anxiety scores in the music and the non-music groups were 38.7 and 41.3 points, respectively. VAS was lower in music group (2.55 VS 3.33). The percent change of anxiety was greater in the music group, although there was no significant difference between two groups. Music therapy did not significantly reduce anxiety in patients undergoing the LLETZ procedure. However, different interventions should be developed to ease the patients' apprehension during this procedure.

  3. A fast, easy circumcision procedure combining a CO2 laser and cyanoacrylate adhesive: a non-randomized comparative trial

    Directory of Open Access Journals (Sweden)

    Tahsin Gorgulu

    2016-02-01

    Full Text Available ABSTRACT Background Circumcision is performed as a routine operation in many countries, more commonly for religious and cultural reasons than for indicated conditions, such as phimosis and balanitis. There are many techniques available, and recently electrocautery and both Nd:YAG and CO2 lasers, instead of blades, have been used for skin and mucosal incisions. However, the infection risk in circumcisions performed using a CO2 laser was 10% higher. There are also reports of sutureless procedures using cyanoacrylate, but these have higher risks of hematoma and hemorrhage. We combined a CO2 laser and cyanoacrylate to shorten the operation time and to decrease bleeding complications. Materials and Methods : Circumcisions were performed under general anesthesia with CO2 laser and cyanoacrylate combination in 75 6–9-year-old boys between May 2013 and August 2014 only for religious reasons. As a control, we compared them retrospectively with 75 age-matched patients who were circumcised using the conventional guillotine method in our clinic. Results No hematomas, bleeding, or wound infections were observed. One wound dehiscence (1.33% occurred during the early postoperative period and healed without any additional procedures. The median operating time was 7 (range 6–9 minutes. The conventional guillotine group comprised one hematoma (1.3%, two wound dehiscences (2.6%, and two hemorrhages (2.6%, and the median operating time was 22 (range 20–26 minutes. The difference in surgical time was significant (p<0.001, with no significant difference in the rate of complications between the two groups. Conclusion The combined CO2 laser and cyanoacrylate procedure not only decreased the operating time markedly, but also eliminated the disadvantages associated with each individual procedure alone.

  4. Comparison of Column Solid-Phase Extraction Procedures for Spectrophotometric Determination of E129 (Allura Red) in Foodstuff, Pharmaceutical, and Energy Drink Samples.

    Science.gov (United States)

    Bişgin, Abdullah Taner; Uçan, Mustafa; Narin, İbrahim

    2015-01-01

    Two novel spectrophotometric determination procedures based on retention of Allura Red onto Amberlite XAD-1180 and XAD-16 resins for its preconcentration, purification, and separation were developed. Analytical parameters of the methods including pH, eluent type, sample volume, and sample and eluent flow rates, were investigated and optimized. Interference effects of some cations, anions, and widely used food dyes were also investigated. Detection limits of the two methods were found to be 1.2 and 1.5 μg/L for XAD-1180 and XAD-16 columns, respectively, under optimum conditions. Linear calibration curve ranges of the methods were 0.4-8.0 and 0.5-6.0 μg/mL of Allura Red for XAD-1180 and XAD-16 resins, respectively. Preconcentration factors were found as 80 for both the XAD-1180 and XAD-16 columns using maximum sample volume and minimum eluent volume. RSDs of the methods were below 6% throughout all experiments. All absorbance measurements were performed at 506 nm. Validations of the methods were performed comparatively with determination of the Allura Red contents of some foodstuff, pharmaceutical, and energy drink samples. Allura Red concentrations in investigated solid and liquid samples ranged from 298 to 501 μg/g and 53.8 to 508 μg/mL, respectively. Satisfactory results were obtained from the real samples analysis. Allura Red contents of samples were determined to be highly similar using the two extraction methods. Comparisons of the methods were performed by analysis of Allura Red contents of the real samples. In addition to analytical parameters, adsorption isotherm studies were performed for the two kinds of Amberlite resins. It was observed that developed methods fit the linear form of the Freundlich adsorption isotherm model. All of the experimental results suggested that the developed SPE procedures are suitable for separation, preconcentration, and determination of Allura Red in solid and liquid matrixes.

  5. 46 CFR Appendix D to Subpart C to... - Sampling and Analytical Methods for Benzene Monitoring-Measurement Procedures

    Science.gov (United States)

    2010-10-01

    ... mm portion of urethane foam is placed between the outlet end of the tube and the back-up section. A... be taken in the employee's breathing zone (i.e., air that would most nearly represent that inhaled by... percent of that found on the front section, the possibility of sample loss exists. 3. Apparatus 3.1. A...

  6. A nanoparticle-based solid-phase extraction procedure followed by spectrofluorimetry to determine carbaryl in different water samples

    Energy Technology Data Exchange (ETDEWEB)

    Tabrizi, Ahad Bavili, E-mail: a.bavili@tbzmed.ac.ir, E-mail: abavilitabrizia@gmail.com [Biotechnology Research Center, Tabriz University of Medical Sciences, Tabriz (Iran, Islamic Republic of); Rashidi, Mohammad Reza [Research Center for Pharmaceutical Nanotechnology, Tabriz University of Medical Sciences, Tabriz, (Iran, Islamic Republic of); Ostadi, Hadi [Department of Chemistry, Payam-e-noor University, Ardabil Branch, Ardabil (Iran, Islamic Republic of)

    2014-04-15

    In this study, a new method based on Fe{sub 3}O{sub 4} magnetite nanoparticles (MNPs) has been developed for the extraction, preconcentration and determination of trace amounts of carbaryl from environmental water samples. Fe{sub 3}O{sub 4} MNPs were synthesized and modified by the surfactant sodium dodecyl sulfate (SDS), then successfully applied for the extraction of carbaryl and its determination by spectrofluorimetry. Main factors affecting the adsolubilization of carbaryl such as the amount of SDS, pH value, standing time, desorption solvent and maximal extraction volume were optimized. Under the selected conditions, carbaryl could be quantitatively extracted. Acceptable recoveries (84.5-91.9%) and relative standard deviations (6.2%) were achieved in analyzing spiked water samples. A concentration factor of 20 was achieved by the extraction of 100 mL of environmental water samples. The limit of detection and quantification were found to be 2.1 and 6.9 μg L{sup -1}, respectively. The proposed method was successfully applied for the extraction and determination of carbaryl in environmental water samples. (author)

  7. 7 CFR 52.38c - Statistical sampling procedures for lot inspection of processed fruits and vegetables by attributes.

    Science.gov (United States)

    2010-01-01

    ... processed fruits and vegetables by attributes. 52.38c Section 52.38c Agriculture Regulations of the... FRUITS AND VEGETABLES, PROCESSED PRODUCTS THEREOF, AND CERTAIN OTHER PROCESSED FOOD PRODUCTS 1... inspection of processed fruits and vegetables by attributes. (a) General. Single sampling plans shall be used...

  8. High Field In Vivo 13C Magnetic Resonance Spectroscopy of Brain by Random Radiofrequency Heteronuclear Decoupling and Data Sampling

    Science.gov (United States)

    Li, Ningzhi; Li, Shizhe; Shen, Jun

    2017-06-01

    In vivo 13C magnetic resonance spectroscopy (MRS) is a unique and effective tool for studying dynamic human brain metabolism and the cycling of neurotransmitters. One of the major technical challenges for in vivo 13C-MRS is the high radio frequency (RF) power necessary for heteronuclear decoupling. In the common practice of in vivo 13C-MRS, alkanyl carbons are detected in the spectra range of 10-65ppm. The amplitude of decoupling pulses has to be significantly greater than the large one-bond 1H-13C scalar coupling (1JCH=125-145 Hz). Two main proton decoupling methods have been developed: broadband stochastic decoupling and coherent composite or adiabatic pulse decoupling (e.g., WALTZ); the latter is widely used because of its efficiency and superb performance under inhomogeneous B1 field. Because the RF power required for proton decoupling increases quadratically with field strength, in vivo 13C-MRS using coherent decoupling is often limited to low magnetic fields (Drug Administration (FDA). Alternately, carboxylic/amide carbons are coupled to protons via weak long-range 1H-13C scalar couplings, which can be decoupled using low RF power broadband stochastic decoupling. Recently, the carboxylic/amide 13C-MRS technique using low power random RF heteronuclear decoupling was safely applied to human brain studies at 7T. Here, we review the two major decoupling methods and the carboxylic/amide 13C-MRS with low power decoupling strategy. Further decreases in RF power deposition by frequency-domain windowing and time-domain random under-sampling are also discussed. Low RF power decoupling opens the possibility of performing in vivo 13C experiments of human brain at very high magnetic fields (such as 11.7T), where signal-to-noise ratio as well as spatial and temporal spectral resolution are more favorable than lower fields.

  9. Rationale, design, methodology and sample characteristics for the Vietnam pre-conceptual micronutrient supplementation trial (PRECONCEPT: a randomized controlled study

    Directory of Open Access Journals (Sweden)

    Nguyen Phuong H

    2012-10-01

    Full Text Available Abstract Background Low birth weight and maternal anemia remain intractable problems in many developing countries. The adequacy of the current strategy of providing iron-folic acid (IFA supplements only during pregnancy has been questioned given many women enter pregnancy with poor iron stores, the substantial micronutrient demand by maternal and fetal tissues, and programmatic issues related to timing and coverage of prenatal care. Weekly IFA supplementation for women of reproductive age (WRA improves iron status and reduces the burden of anemia in the short term, but few studies have evaluated subsequent pregnancy and birth outcomes. The Preconcept trial aims to determine whether pre-pregnancy weekly IFA or multiple micronutrient (MM supplementation will improve birth outcomes and maternal and infant iron status compared to the current practice of prenatal IFA supplementation only. This paper provides an overview of study design, methodology and sample characteristics from baseline survey data and key lessons learned. Methods/design We have recruited 5011 WRA in a double-blind stratified randomized controlled trial in rural Vietnam and randomly assigned them to receive weekly supplements containing either: 1 2800 μg folic acid 2 60 mg iron and 2800 μg folic acid or 3 MM. Women who become pregnant receive daily IFA, and are being followed through pregnancy, delivery, and up to three months post-partum. Study outcomes include birth outcomes and maternal and infant iron status. Data are being collected on household characteristics, maternal diet and mental health, anthropometry, infant feeding practices, morbidity and compliance. Discussion The study is timely and responds to the WHO Global Expert Consultation which identified the need to evaluate the long term benefits of weekly IFA and MM supplementation in WRA. Findings will generate new information to help guide policy and programs designed to reduce the burden of anemia in women and

  10. Determination of novel brominated flame retardants and polybrominated diphenyl ethers in serum using gas chromatography-mass spectrometry with two simplified sample preparation procedures.

    Science.gov (United States)

    Gao, Le; Li, Jian; Wu, Yandan; Yu, Miaohao; Chen, Tian; Shi, Zhixiong; Zhou, Xianqing; Sun, Zhiwei

    2016-11-01

    Two simple and efficient pretreatment procedures have been developed for the simultaneous extraction and cleanup of six novel brominated flame retardants (NBFRs) and eight common polybrominated diphenyl ethers (PBDEs) in human serum. The first sample pretreatment procedure was a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based approach. An acetone/hexane mixture was employed to isolate the lipid and analytes from the serum with a combination of MgSO4 and NaCl, followed by a dispersive solid-phase extraction (d-SPE) step using C18 particles as a sorbent. The second sample pretreatment procedure was based on solid-phase extraction. The sample extraction and cleanup were conducted directly on an Oasis HLB SPE column using 5 % aqueous isopropanol, concentrated sulfuric acid, and 10 % aqueous methanol, followed by elution with dichloromethane. The NBFRs and PBDEs were then detected using gas chromatography-negative chemical ionization mass spectrometry (GC-NCI MS). The methods were assessed for repeatability, accuracy, selectivity, limits of detection (LODs), and linearity. The results of spike recovery experiments in fetal bovine serum showed that average recoveries ranged from 77.9 % to 128.8 % with relative standard deviations (RSDs) from 0.73 % to 12.37 % for most of the analytes. The LODs for the analytes in fetal bovine serum ranged from 0.3 to 50.8 pg/mL except for decabromodiphenyl ethane. The proposed method was successfully applied to the determination of the 14 brominated flame retardants in human serum. The two pretreatment procedures described here are simple, accurate, and precise, and are suitable for the routine analysis of human serum. Graphical Abstract Workflow of a QuEChERS-based approach (top) and an SPE-based approach (bottom) for the detection of PBDEs and NBFRs in serum.

  11. Development and optimization of the SPE procedure for determination of pharmaceuticals in water samples by HPLC-diode array detection.

    Science.gov (United States)

    Mutavdzić Pavlović, Dragana; Babić, Sandra; Dolar, Davor; Asperger, Danijela; Kosutić, Kresimir; Horvat, Alka J M; Kastelan-Macan, Marija

    2010-02-01

    This paper focuses on the investigation of different types of SPE sorbents for the preconcentration of eight veterinary pharmaceuticals from water samples. The pharmaceuticals studied were sulfamethazine, sulfadiazine, sulfaguanidine, trimethoprim, oxytetracycline, enrofloxacin, norfloxacin and penicillin G/procaine. Five different SPE materials (Strata-X, Strata-X-C, Strata SDB-L, Strata C8 and Strata C18) from Phenomenex were compared with Oasis HLB with a view to obtaining the best cartridges for all pharmaceuticals investigated. Extraction efficiency was determined by HPLC with diode array detection (DAD). HPLC-DAD separation and quantification of the selected pharmaceuticals were carried out under gradient elution by a binary mixture of 0.01 M oxalic acid and ACN based on cyano modified column (LiChrosphere 100 CN) from Merck. Strata-X provided the best results in the preconcentration of 100 mL water samples, yielding average pharmaceutical recoveries of higher than 90%, except for sulfaguanidine (76.1%). The developed Strata-X-HLPC-DAD method was validated and applied, for the efficient investigation of reverse osmosis/nanofiltration membranes and for the removal of these eight pharmaceuticals from the production wastewater samples. NF90 and XLE membranes were shown to be the best for the rejection of all investigated pharmaceuticals.

  12. Blood Flow Velocity in Brachial and Subclavian Vessels Immediately After Compressive Procedures for Treatment of Postcancer Therapy Lymphedema in Breast Cancer: A Randomized Blind Clinical Trial.

    Science.gov (United States)

    Rezende, Monique Silva; Marsengo, Ana Luiza; de Jesus Guirro, Rinaldo Roberto; de Oliveira Guirro, Elaine Caldeira

    2017-03-01

    This study sought to evaluate the effect of elastic compression, functional compressive bandaging, and kinesiotherapy on blood flow of the upper limb with lymphedema secondary to the treatment of breast cancer. This was a randomized blind crossover clinical trial with a washout period of 7 days between treatments. We evaluated 20 women with a mean age of 66.85 years (standard deviation = 11.76), undergoing three types of therapeutic procedures randomly applied by lot: kinesiotherapy, functional compressive bandaging + kinesiotherapy (FCB), and elastic compression + kinesiotherapy (EC). Blood flow, including mean and maximum velocity, was assessed by Doppler ultrasound before and after the therapeutic procedure (immediately after, 15 minutes, and 30 minutes). We used two-way analysis of variance for repeated measures followed by Bonferroni's test, considering a significance level of 5%. The EC and FCB groups showed a significant increase in the mean velocity of blood flow in the axillary and brachial arteries and veins compared to the group that received only kinesiotherapy (p  0.05). Moreover, the EC and FCB groups showed greater increase in maximum velocity of blood flow in the brachial artery (p  0.05). Elastic compression and functional compressive bandaging combined with kinesiotherapy increased blood flow of upper limb lymphedema.

  13. Comparing attitudes about legal sanctions and teratogenic effects for cocaine, alcohol, tobacco and caffeine: A randomized, independent samples design

    Directory of Open Access Journals (Sweden)

    Alanis Kelly L

    2006-02-01

    Full Text Available Abstract Background Establishing more sensible measures to treat cocaine-addicted mothers and their children is essential for improving U.S. drug policy. Favorable post-natal environments have moderated potential deleterious prenatal effects. However, since cocaine is an illicit substance having long been demonized, we hypothesized that attitudes toward prenatal cocaine exposure would be more negative than for licit substances, alcohol, nicotine and caffeine. Further, media portrayals about long-term outcomes were hypothesized to influence viewers' attitudes, measured immediately post-viewing. Reducing popular crack baby stigmas could influence future policy decisions by legislators. In Study 1, 336 participants were randomly assigned to 1 of 4 conditions describing hypothetical legal sanction scenarios for pregnant women using cocaine, alcohol, nicotine or caffeine. Participants rated legal sanctions against pregnant women who used one of these substances and risk potential for developing children. In Study 2, 139 participants were randomly assigned to positive, neutral and negative media conditions. Immediately post-viewing, participants rated prenatal cocaine-exposed or non-exposed teens for their academic performance and risk for problems at age18. Results Participants in Study 1 imposed significantly greater legal sanctions for cocaine, perceiving prenatal cocaine exposure as more harmful than alcohol, nicotine or caffeine. A one-way ANOVA for independent samples showed significant differences, beyond .0001. Post-hoc Sheffe test illustrated that cocaine was rated differently from other substances. In Study 2, a one-way ANOVA for independent samples was performed on difference scores for the positive, neutral or negative media conditions about prenatal cocaine exposure. Participants in the neutral and negative media conditions estimated significantly lower grade point averages and more problems for the teen with prenatal cocaine exposure

  14. Comparing attitudes about legal sanctions and teratogenic effects for cocaine, alcohol, tobacco and caffeine: A randomized, independent samples design

    Science.gov (United States)

    Ginsburg, Harvey J; Raffeld, Paul; Alanis, Kelly L; Boyce, Angela S

    2006-01-01

    Background Establishing more sensible measures to treat cocaine-addicted mothers and their children is essential for improving U.S. drug policy. Favorable post-natal environments have moderated potential deleterious prenatal effects. However, since cocaine is an illicit substance having long been demonized, we hypothesized that attitudes toward prenatal cocaine exposure would be more negative than for licit substances, alcohol, nicotine and caffeine. Further, media portrayals about long-term outcomes were hypothesized to influence viewers' attitudes, measured immediately post-viewing. Reducing popular crack baby stigmas could influence future policy decisions by legislators. In Study 1, 336 participants were randomly assigned to 1 of 4 conditions describing hypothetical legal sanction scenarios for pregnant women using cocaine, alcohol, nicotine or caffeine. Participants rated legal sanctions against pregnant women who used one of these substances and risk potential for developing children. In Study 2, 139 participants were randomly assigned to positive, neutral and negative media conditions. Immediately post-viewing, participants rated prenatal cocaine-exposed or non-exposed teens for their academic performance and risk for problems at age18. Results Participants in Study 1 imposed significantly greater legal sanctions for cocaine, perceiving prenatal cocaine exposure as more harmful than alcohol, nicotine or caffeine. A one-way ANOVA for independent samples showed significant differences, beyond .0001. Post-hoc Sheffe test illustrated that cocaine was rated differently from other substances. In Study 2, a one-way ANOVA for independent samples was performed on difference scores for the positive, neutral or negative media conditions about prenatal cocaine exposure. Participants in the neutral and negative media conditions estimated significantly lower grade point averages and more problems for the teen with prenatal cocaine exposure than for the non-exposed teen

  15. A Randomized Controlled Trial of Two Syntactic Treatment Procedures With Cantonese-Speaking, School-Age Children With Language Disorders.

    Science.gov (United States)

    To, Carol K S; Lui, Hoi Ming; Li, Xin Xin; Lam, Gary Y H

    2015-08-01

    In this study, we aimed to evaluate the efficacy of sentence-combining (SC) and narrative-based (NAR) intervention approaches to syntax intervention using a randomized-controlled-trial design. Fifty-two Cantonese-speaking, school-age children with language impairment were assigned randomly to either the SC or the NAR treatment arm. Seven children did not receive treatment as assigned. Intervention in both arms targeted the same complex syntactical structures. The SC group focused on sentence combination training, whereas the NAR group made use of narratives in which the target structures were embedded. Pretest and posttest performances measured using a standardized language assessment were subjected to analyses of covariance mixed-effect-model analyses of variance. Children in both treatment arms demonstrated significant growth after 4 months of intervention. The main effect between treatment arms and time was not significant after controlling the pretest performance, suggesting that both treatment approaches showed similar effects. The main effect of time was significant. This study provided evidence to support language intervention in the school years in Cantonese-speaking children. However, neither approach was shown to be more efficacious than the other. Future researchers could examine the effects of a longer treatment period and include functional outcome measures.

  16. Development of a candidate reference measurement procedure for the analysis of cortisol in human serum samples by isotope dilution-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kawaguchi, Migaku; Takatsu, Akiko

    2009-08-01

    A candidate reference measurement procedure involving isotope dilution coupled with gas chromatography-mass spectrometry (GC-MS) has been developed and critically evaluated. An isotopically labeled internal standard, cortisol-d(2), was added to a serum sample. After equilibration, solid-phase extractions (SPE) for sample preparation and derivatization with heptafluorobutyric anhydride (HFBA) were performed for GC-MS analysis. The limit of detection (LOD) and the limit of quantification (LOQ) were 5 and 20 ng g(-1), respectively. The recovery of the added cortisol ranged from 99.8 to 101.0%. Excellent precision was obtained with a within-day variation (RSD) of 0.7% for GC-MS analysis. The accuracy of the measurement was evaluated by comparing of results of this reference measurement procedure on lyophilized human serum reference materials for cortisol (European Reference Materials (ERM)-DA 192) as Certified Reference Materials (CRMs). The results of this method for total cortisol agreed with the certified values within some uncertainty. This method, which demonstrates simply, easy, good accuracy, high precision, and is free from interferences from structural analogues, qualifies as a reference measurement procedure.

  17. GC-MS identification of proteins in wall painting samples: a fast clean-up procedure to remove copper-based pigment interferences.

    Science.gov (United States)

    Gautier, Gwénaëlle; Colombini, Maria Perla

    2007-08-15

    A new approach was explored to purify proteins in a multi-step procedure for the characterisation of proteinaceous materials (casein, animal glue, and egg) in artwork samples by gas chromatography-mass spectrometry. High concentrations of inorganic salts, such as azurite, have been found to impair the determination of protein via amino acid analysis. The effect of varying concentrations of copper-based pigments on the quantification of amino acids was evaluated through the analysis of replica paintings prepared with the three types of proteinaceous materials. Glycine, aspartic and glutamic acids are the amino acids most affected by the presence of copper salts. In the case of high concentration of salts, this interference hampers the correct identification of the proteins. To eliminate the inorganic salts, a C18 pipette tip was used to clean-up the ammonia extracts before the acidic hydrolysis step. The clean-up procedure allows us to prevent the influence of the inorganic salts and thus allows correct protein identification, though the quantitative recovery of proteinaceous material is quite low. The effectiveness of the optimised procedure was evaluated by analysing samples from two Italian wall paintings from the 13th and the 14th centuries. Without the clean-up it would not have been possible to detect the presence of a mixture of egg and animal glue in one case, and that of egg in the other one.

  18. Multicriteria optimisation of a simultaneous supercritical fluid extraction and clean-up procedure for the determination of persistent organohalogenated pollutants in aquaculture samples.

    Science.gov (United States)

    Rodil, R; Carro, A M; Lorenzo, R A; Cela, R

    2007-04-01

    A useful tool based on a single-step extraction and clean-up procedure for the determination of 15 organohalogenated pollutants (including brominated flame retardants) in aquaculture samples, using aluminium oxide basic and acidic silica gel in the supercritical extraction cell followed by gas chromatography with electron capture detection or mass spectrometry has been developed. This effective clean-up step ensures a minimum of chromatographic difficulties related to complex matrix components such as aquaculture feed. The extraction procedure has been screened by a fractional factorial design for the preliminary statistically significant parameters. The factors selected were extraction temperature, pressure, static extraction time, dynamic extraction time and carbon dioxide flow rate. The Doehlert design, followed by a multicriteria decision-making strategy, was then performed in order to determine the optimum conditions for the two most significant factors: pressure (165 bar) and dynamic extraction time (27 min). Under optimal conditions, the procedure developed with GC-MS/MS provides an excellent linearity, detection (0.01-0.2 ng g(-1)) and quantification limits (0.05-0.8 ng g(-1)) for most of the analytes investigated. The feasibility of the proposed supercritical fluid extraction method was validated by analysing two reference materials and fish feed and shellfish samples with satisfactory results.

  19. Standard operating procedures for collection of soil and sediment samples for the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study

    Science.gov (United States)

    Fisher, Shawn C.; Reilly, Timothy J.; Jones, Daniel K.; Benzel, William M.; Griffin, Dale W.; Loftin, Keith A.; Iwanowicz, Luke R.; Cohl, Jonathan A.

    2015-12-17

    An understanding of the effects on human and ecological health brought by major coastal storms or flooding events is typically limited because of a lack of regionally consistent baseline and trends data in locations proximal to potential contaminant sources and mitigation activities, sensitive ecosystems, and recreational facilities where exposures are probable. In an attempt to close this gap, the U.S. Geological Survey (USGS) has implemented the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study to collect regional sediment-quality data prior to and in response to future coastal storms. The standard operating procedure (SOP) detailed in this document serves as the sample-collection protocol for the SCoRR strategy by providing step-by-step instructions for site preparation, sample collection and processing, and shipping of soil and surficial sediment (for example, bed sediment, marsh sediment, or beach material). The objectives of the SCoRR strategy pilot study are (1) to create a baseline of soil-, sand-, marsh sediment-, and bed-sediment-quality data from sites located in the coastal counties from Maine to Virginia based on their potential risk of being contaminated in the event of a major coastal storm or flooding (defined as Resiliency mode); and (2) respond to major coastal storms and flooding by reoccupying select baseline sites and sampling within days of the event (defined as Response mode). For both modes, samples are collected in a consistent manner to minimize bias and maximize quality control by ensuring that all sampling personnel across the region collect, document, and process soil and sediment samples following the procedures outlined in this SOP. Samples are analyzed using four USGS-developed screening methods—inorganic geochemistry, organic geochemistry, pathogens, and biological assays—which are also outlined in this SOP. Because the SCoRR strategy employs a multi-metric approach for sample analyses, this

  20. Chapter A5. Section 2.2B. Syringe-Filter Procedure for Processing Samples for Analysis of Organic Compounds by DAI LC-MS/MS

    Science.gov (United States)

    Sandstrom, Mark W.; Wilde, Franceska D.

    2014-01-01

    This section of chapter 5 of the National Field Manual for the Collection of Water-Quality Data (NFM) describes the field procedures for collecting small-volume samples using a syringe-tip filtration method. The samples are sent to the U.S. Geological Survey (USGS) National Water Quality Laboratory (NWQL) for analysis of organic compounds by direct aqueous injection high-performance liquid chromatography/tandem mass spectrometry (DAI LC-MS/MS). The DAI LC-MS/MS method was developed specifically for NWQL analytical schedules 2437 (pesticides) and 2440 (pharmaceuticals) and should not be considered transferrable or applicable to other types of samples to be analyzed using methods other than those that use DAI LC-MS/MS or other tandem mass

  1. Association of macronutrient intake patterns with being overweight in a population-based random sample of men in France.

    Science.gov (United States)

    Ahluwalia, N; Ferrières, J; Dallongeville, J; Simon, C; Ducimetière, P; Amouyel, P; Arveiler, D; Ruidavets, J-B

    2009-04-01

    Diet is considered an important modifiable factor in the overweight. The role of macronutrients in obesity has been examined in general in selected populations, but the results of these studies are mixed, depending on the potential confounders and adjustments for other macronutrients. For this reason, we examined the association between macronutrient intake patterns and being overweight in a population-based representative sample of middle-aged (55.1+/-6.1 years) men (n=966), using various adjustment modalities. The study subjects kept 3-day food-intake records, and the standard cardiovascular risk factors were assessed. Weight, height and waist circumference (WC) were also measured. Carbohydrate intake was negatively associated and fat intake was positively associated with body mass index (BMI) and WC in regression models adjusted for energy intake and other factors, including age, smoking and physical activity. However, with mutual adjustments for other energy-yielding nutrients, the negative association of carbohydrate intake with WC remained significant, whereas the associations between fat intake and measures of obesity did not. Adjusted odds ratios (95% confidence interval) comparing the highest and lowest quartiles of carbohydrate intake were 0.50 (0.25-0.97) for obesity (BMI>29.9) and 0.41 (0.23-0.73) for abdominal obesity (WC>101.9 cm). Consistent negative associations between carbohydrate intake and BMI and WC were seen in this random representative sample of the general male population. The associations between fat intake and these measures of being overweight were attenuated on adjusting for carbohydrate intake. Thus, the balance of carbohydrate-to-fat intake is an important element in obesity in a general male population, and should be highlighted in dietary guidelines.

  2. GRASP (Greedy Randomized Adaptive Search Procedures) applied to optimization of petroleum products distribution in pipeline networks; GRASP (Greedy Randomized Adaptative Search Procedures) aplicado ao 'scheduling' de redes de distribuicao de petroleo e derivados

    Energy Technology Data Exchange (ETDEWEB)

    Conte, Viviane Cristhyne Bini; Arruda, Lucia Valeria Ramos de; Yamamoto, Lia [Universidade Tecnologica Federal do Parana (UTFPR), Curitiba, PR (Brazil)

    2008-07-01

    Planning and scheduling of the pipeline network operations aim the most efficient use of the resources resulting in a better performance of the network. A petroleum distribution pipeline network is composed by refineries, sources and/or storage parks, connected by a set of pipelines, which operate the transportation of petroleum and derivatives among adjacent areas. In real scenes, this problem is considered a combinatorial problem, which has difficult solution, which makes necessary methodologies of the resolution that present low computational time. This work aims to get solutions that attempt the demands and minimize the number of batch fragmentations on the sent operations of products for the pipelines in a simplified model of a real network, through by application of the local search metaheuristic GRASP. GRASP does not depend of solutions of previous iterations and works in a random way so it allows the search for the solution in an ampler and diversified search space. GRASP utilization does not demand complex calculation, even the construction stage that requires more computational effort, which provides relative rapidity in the attainment of good solutions. GRASP application on the scheduling of the operations of this network presented feasible solutions in a low computational time. (author)

  3. Randomized, Double-Blind, Placebo-Controlled Study on Decolonization Procedures for Methicillin-Resistant Staphylococcus aureus (MRSA among HIV-Infected Adults.

    Directory of Open Access Journals (Sweden)

    Amy Weintrob

    Full Text Available HIV-infected persons have increased risk of MRSA colonization and skin and soft-tissue infections (SSTI. However, no large clinical trial has examined the utility of decolonization procedures in reducing MRSA colonization or infection among community-dwelling HIV-infected persons.550 HIV-infected adults at four geographically diverse US military HIV clinics were prospectively screened for MRSA colonization at five body locations every 6 months during a 2-year period. Those colonized were randomized in a double-blind fashion to nasal mupirocin (Bactroban twice daily and hexachlorophene (pHisoHex soaps daily for 7 days compared to placeboes similar in appearance but without specific antibacterial activity. The primary endpoint was MRSA colonization at 6-months post-randomization; secondary endpoints were time to MRSA clearance, subsequent MRSA infections/SSTI, and predictors for MRSA clearance at the 6-month time point.Forty-nine (9% HIV-infected persons were MRSA colonized and randomized. Among those with 6-month colonization data (80% of those randomized, 67% were negative for MRSA colonization in both groups (p = 1.0. Analyses accounting for missing 6-month data showed no significant differences could have been achieved. In the multivariate adjusted models, randomization group was not associated with 6-month MRSA clearance. The median time to MRSA clearance was similar in the treatment vs. placebo groups (1.4 vs. 1.8 months, p = 0.35. There was no difference on subsequent development of MRSA infections/SSTI (p = 0.89. In a multivariable model, treatment group, demographics, and HIV-specific factors were not predictive of MRSA clearance at the 6-month time point.A one-week decolonization procedure had no effect on MRSA colonization at the 6-month time point or subsequent infection rates among community-dwelling HIV-infected persons. More aggressive or novel interventions may be needed to reduce the burden of MRSA in this population

  4. Randomized, Double-Blind, Placebo-Controlled Study on Decolonization Procedures for Methicillin-Resistant Staphylococcus aureus (MRSA) among HIV-Infected Adults

    Science.gov (United States)

    Weintrob, Amy; Bebu, Ionut; Agan, Brian; Diem, Alona; Johnson, Erica; Lalani, Tahaniyat; Wang, Xun; Bavaro, Mary; Ellis, Michael; Mende, Katrin; Crum-Cianflone, Nancy

    2015-01-01

    Background HIV-infected persons have increased risk of MRSA colonization and skin and soft-tissue infections (SSTI). However, no large clinical trial has examined the utility of decolonization procedures in reducing MRSA colonization or infection among community-dwelling HIV-infected persons. Methods 550 HIV-infected adults at four geographically diverse US military HIV clinics were prospectively screened for MRSA colonization at five body locations every 6 months during a 2-year period. Those colonized were randomized in a double-blind fashion to nasal mupirocin (Bactroban) twice daily and hexachlorophene (pHisoHex) soaps daily for 7 days compared to placeboes similar in appearance but without specific antibacterial activity. The primary endpoint was MRSA colonization at 6-months post-randomization; secondary endpoints were time to MRSA clearance, subsequent MRSA infections/SSTI, and predictors for MRSA clearance at the 6-month time point. Results Forty-nine (9%) HIV-infected persons were MRSA colonized and randomized. Among those with 6-month colonization data (80% of those randomized), 67% were negative for MRSA colonization in both groups (p = 1.0). Analyses accounting for missing 6-month data showed no significant differences could have been achieved. In the multivariate adjusted models, randomization group was not associated with 6-month MRSA clearance. The median time to MRSA clearance was similar in the treatment vs. placebo groups (1.4 vs. 1.8 months, p = 0.35). There was no difference on subsequent development of MRSA infections/SSTI (p = 0.89). In a multivariable model, treatment group, demographics, and HIV-specific factors were not predictive of MRSA clearance at the 6-month time point. Conclusion A one-week decolonization procedure had no effect on MRSA colonization at the 6-month time point or subsequent infection rates among community-dwelling HIV-infected persons. More aggressive or novel interventions may be needed to reduce the burden of MRSA in

  5. A prospective, randomized, double blinded comparison of intranasal dexmedetomodine vs intranasal ketamine in combination with intravenous midazolam for procedural sedation in school aged children undergoing MRI.

    Science.gov (United States)

    Ibrahim, Mohamed

    2014-01-01

    For optimum magnetic resonance imaging (MRI) image quality and to ensure precise diagnosis, patients have to remain motionless. We studied the effects of intranasal dexmedetomidine and ketamine with intravenous midazolam for pre-procedural and procedural sedation in school aged children. Children were randomly allocated to one of two groups: (Group D) received intranasal dexmedetomidine 3 μg kg(-1) and (Group K) received intranasal ketamine 7 mg kg(-1). Sedation levels 10, 20 and 30 min after drug instillation were evaluated using a Modified Ramsay sedation scale. A 4-point score was used to evaluate patients when they were separated from their parents and their response to intravenous cannulation. The two groups were comparable in terms of the child's anxiety at presentation (P = 0.245). We observed that Group K achieved faster sedation at 10 min point with P Intranasal dexmedetomidine 3 μg kg(-1) or ketamine 7 mg kg(-1) can be used safely and effectively to induce a state of moderate conscious sedation and to facilitate parents' separation and IV cannulation. Addition of midazolam in a dose not sufficient alone to produce the target sedation achieved our goal of deep level of sedation suitable for MRI procedure.

  6. Assessing causality in associations between cannabis use and schizophrenia risk: a two-sample Mendelian randomization study.

    Science.gov (United States)

    Gage, S H; Jones, H J; Burgess, S; Bowden, J; Davey Smith, G; Zammit, S; Munafò, M R

    2017-04-01

    Observational associations between cannabis and schizophrenia are well documented, but ascertaining causation is more challenging. We used Mendelian randomization (MR), utilizing publicly available data as a method for ascertaining causation from observational data. We performed bi-directional two-sample MR using summary-level genome-wide data from the International Cannabis Consortium (ICC) and the Psychiatric Genomics Consortium (PGC2). Single nucleotide polymorphisms (SNPs) associated with cannabis initiation (p schizophrenia (p cannabis initiation on risk of schizophrenia [odds ratio (OR) 1.04 per doubling odds of cannabis initiation, 95% confidence interval (CI) 1.01-1.07, p = 0.019]. There was strong evidence consistent with a causal effect of schizophrenia risk on likelihood of cannabis initiation (OR 1.10 per doubling of the odds of schizophrenia, 95% CI 1.05-1.14, p = 2.64 × 10-5). Findings were as predicted for the negative control (height: OR 1.00, 95% CI 0.99-1.01, p = 0.90) but weaker than predicted for the positive control (years in education: OR 0.99, 95% CI 0.97-1.00, p = 0.066) analyses. Our results provide some that cannabis initiation increases the risk of schizophrenia, although the size of the causal estimate is small. We find stronger evidence that schizophrenia risk predicts cannabis initiation, possibly as genetic instruments for schizophrenia are stronger than for cannabis initiation.

  7. Mental health impact of the 2010 Haiti earthquake on the Miami Haitian population: A random-sample survey.

    Science.gov (United States)

    Messiah, Antoine; Acuna, Juan M; Castro, Grettel; de la Vega, Pura Rodríguez; Vaiva, Guillaume; Shultz, James; Neria, Yuval; De La Rosa, Mario

    2014-07-01

    This study examined the mental health consequences of the January 2010 Haiti earthquake on Haitians living in Miami-Dade County, Florida, 2-3 years following the event. A random-sample household survey was conducted from October 2011 through December 2012 in Miami-Dade County, Florida. Haitian participants (N = 421) were assessed for their earthquake exposure and its impact on family, friends, and household finances; and for symptoms of posttraumatic stress disorder (PTSD), anxiety, and major depression; using standardized screening measures and thresholds. Exposure was considered as "direct" if the interviewee was in Haiti during the earthquake. Exposure was classified as "indirect" if the interviewee was not in Haiti during the earthquake but (1) family members or close friends were victims of the earthquake, and/or (2) family members were hosted in the respondent's household, and/or (3) assets or jobs were lost because of the earthquake. Interviewees who did not qualify for either direct or indirect exposure were designated as "lower" exposure. Eight percent of respondents qualified for direct exposure, and 63% qualified for indirect exposure. Among those with direct exposure, 19% exceeded threshold for PTSD, 36% for anxiety, and 45% for depression. Corresponding percentages were 9%, 22% and 24% for respondents with indirect exposure, and 6%, 14%, and 10% for those with lower exposure. A majority of Miami Haitians were directly or indirectly exposed to the earthquake. Mental health distress among them remains considerable two to three years post-earthquake.

  8. Mental Health Impact of Hosting Disaster Refugees: Analyses from a Random Sample Survey Among Haitians Living in Miami.

    Science.gov (United States)

    Messiah, Antoine; Lacoste, Jérôme; Gokalsing, Erick; Shultz, James M; Rodríguez de la Vega, Pura; Castro, Grettel; Acuna, Juan M

    2016-08-01

    Studies on the mental health of families hosting disaster refugees are lacking. This study compares participants in households that hosted 2010 Haitian earthquake disaster refugees with their nonhost counterparts. A random sample survey was conducted from October 2011 through December 2012 in Miami-Dade County, Florida. Haitian participants were assessed regarding their 2010 earthquake exposure and impact on family and friends and whether they hosted earthquake refugees. Using standardized scores and thresholds, they were evaluated for symptoms of three common mental disorders (CMDs): posttraumatic stress disorder, generalized anxiety disorder, and major depressive disorder (MDD). Participants who hosted refugees (n = 51) had significantly higher percentages of scores beyond thresholds for MDD than those who did not host refugees (n = 365) and for at least one CMD, after adjusting for participants' earthquake exposures and effects on family and friends. Hosting refugees from a natural disaster appears to elevate the risk for MDD and possibly other CMDs, independent of risks posed by exposure to the disaster itself. Families hosting refugees deserve special attention.

  9. Randomization modeling to ascertain clustering patterns of human papillomavirus types detected in cervicovaginal samples in the United States.

    Directory of Open Access Journals (Sweden)

    Troy David Querec

    Full Text Available Detection of multiple human papillomavirus (HPV types in the genital tract is common. Associations among HPV types may impact HPV vaccination modeling and type replacement. The objectives were to determine the distribution of concurrent HPV type infections in cervicovaginal samples and examine type-specific associations. We analyzed HPV genotyping results from 32,245 cervicovaginal specimens collected from women aged 11 to 83 years in the United States from 2001 through 2011. Statistical power was enhanced by combining 6 separate studies. Expected concurrent infection frequencies from a series of permutation models, each with increasing fidelity to the real data, were compared with the observed data. Statistics were computed based on the distributional properties of the randomized data. Concurrent detection occurred more than expected with 0 or ≥3 HPV types and less than expected with 1 and 2 types. Some women bear a disproportionate burden of the HPV type prevalence. Type associations were observed that exceeded multiple hypothesis corrected significance. Multiple HPV types were detected more frequently than expected by chance and associations among particular HPV types were detected. However vaccine-targeted types were not specifically affected, supporting the expectation that current bivalent/quadrivalent HPV vaccination will not result in type replacement with other high-risk types.

  10. A block variational procedure for the iterative diagonalization of non-Hermitian random-phase approximation matrices.

    Science.gov (United States)

    Rocca, Dario; Bai, Zhaojun; Li, Ren-Cang; Galli, Giulia

    2012-01-21

    We present a technique for the iterative diagonalization of random-phase approximation (RPA) matrices, which are encountered in the framework of time-dependent density-functional theory (TDDFT) and the Bethe-Salpeter equation. The non-Hermitian character of these matrices does not permit a straightforward application of standard iterative techniques used, i.e., for the diagonalization of ground state Hamiltonians. We first introduce a new block variational principle for RPA matrices. We then develop an algorithm for the simultaneous calculation of multiple eigenvalues and eigenvectors, with convergence and stability properties similar to techniques used to iteratively diagonalize Hermitian matrices. The algorithm is validated for simple systems (Na(2) and Na(4)) and then used to compute multiple low-lying TDDFT excitation energies of the benzene molecule. © 2012 American Institute of Physics

  11. Thrombelastography-guided blood product use before invasive procedures in cirrhosis with severe coagulopathy: A randomized, controlled trial.

    Science.gov (United States)

    De Pietri, Lesley; Bianchini, Marcello; Montalti, Roberto; De Maria, Nicola; Di Maira, Tommaso; Begliomini, Bruno; Gerunda, Giorgio Enrico; di Benedetto, Fabrizio; Garcia-Tsao, Guadalupe; Villa, Erica

    2016-02-01

    Bleeding is a feared complication of invasive procedures in patients with cirrhosis and significant coagulopathy (as defined by routine coagulation tests) and is used to justify preprocedure use of fresh frozen plasma (FFP) and/or platelets (PLT). Thromboelastography (TEG) provides a more comprehensive global coagulation assessment than routine tests (international normalized ratio [INR] and platelet count), and its use may avoid unnecessary blood product transfusion in patients with cirrhosis and significant coagulopathy (defined in this study as INR >1.8 and/or platelet count 40 min and/or PLT if maximum amplitude (MA) was <30 mm. All SOC patients received FFP and/or PLT per hospital guidelines. Endpoints were blood product use and bleeding complications. Baseline characteristics of the two groups were similar. Per protocol, all subjects in the SOC group received blood product transfusions versus 5 in the TEG group (100% vs. 16.7%; P < 0.0001). Sixteen SOC (53.3%) received FFP, 10 (33.3%) PLT, and 4 (13.3%) both FFP and PLT. In the TEG group, none received FFP alone (P < 0.0001 vs. SOC), 2 received PLT (6.7%; P = 0.009 vs. SOC), and 3 both FFP and PLT (not significant). Postprocedure bleeding occurred in only 1 patient (SOC group) after large-volume paracentesis. In patients with cirrhosis and significant coagulopathy before invasive procedures, TEG-guided transfusion strategy leads to a significantly lower use of blood products compared to SOC (transfusion guided by INR and platelet count), without an increase in bleeding complications. Remarkably, even in patients with significant coagulopathy, postprocedure bleeding was rare, indicating that TEG thresholds should be reevaluated. © 2015 by the American Association for the Study of Liver Diseases.

  12. Ochratoxin A in raisins and currants: basic extraction procedure used in two small marketing surveys of the occurrence and control of the heterogeneity of the toxins in samples.

    Science.gov (United States)

    Möller, T E; Nyberg, M

    2003-11-01

    A basic extraction procedure for analysis of ochratoxin A (OTA) in currants and raisins is described, as well as the occurrence of OTA and a control of heterogeneity of the toxin in samples bought for two small marketing surveys 1999/2000 and 2001/02. Most samples in the surveys were divided into two subsamples that were individually prepared as slurries and analysed separately. The limit of quantification for the method was estimated as 0.1 microg kg(-1) and recoveries of 85, 90 and 115% were achieved in recovery experiments at 10, 5 and 0.1 microg kg(-1), respectively. Of all 118 subsamples analysed in the surveys, 96 (84%) contained ochratoxin A at levels above the quantification level and five samples (4%) contained more than the European Community legislation of 10 microg kg(-1). The OTA concentrations found in the first survey were in the range Big differences were often achieved between individual subsamples of the original sample, which indicate a wide heterogeneous distribution of the toxin. Data from the repeatability test as well as recovery experiments from the same slurries showed that preparation of slurries as described here seemed to give a homogeneous and representative sample. The extraction with the basic sodium bicarbonate-methanol mixture used in the surveys gave similar or somewhat higher OTA values on some samples tested in a comparison with a weak phosphoric acid water-methanol extraction mixture.

  13. [Acupuncture and moxibustion for peripheral facial palsy at different stages: multi-central large-sample randomized controlled trial].

    Science.gov (United States)

    Li, Ying; Li, Yan; Liu, Li-an; Zhao, Ling; Hu, Ka-ming; Wu, Xi; Chen, Xiao-qin; Li, Gui-ping; Mang, Ling-ling; Qi, Qi-hua

    2011-04-01

    To explore the best intervention time of acupuncture and moxibustion for peripheral facial palsy (Bell's palsy) and the clinical advantage program of selective treatment with acupuncture and moxibustion. Multi-central large-sample randomized controlled trial was carried out. Nine hundreds cases of Bell's palsy were randomized into 5 treatment groups, named selective filiform needle group (group A), selective acupuncture + moxibustion group (group B), selective acupuncture + electroacupuncture (group C), selective acupuncture + line-up needling on muscle region of meridian group (group D) and non-selective filiform needle group (group E). Four sessions of treatment were required in each group. Separately, during the enrollment, after 4 sessions of treatment, in 1 month and 3 months of follow-up after treatment, House-Brackmann Scale, Facial Disability Index Scale and Degree of Facial Nerve Paralysis (NFNP) were adopted for efficacy assessment. And the efficacy systematic analysis was provided in view of the intervention time and nerve localization of disease separately. The curative rates of intervention in acute stage and resting stage were 50.1% (223/445) and 52.1% (162/311), which were superior to recovery stage (25.9%, 35/135) separately. There were no statistical significant differences in efficacy in comparison among 5 treatment programs at the same stage (all P > 0.05). The efficacy of intervention of group A and group E in acute stage was superior to that in recovery stage (both P < 0.01). The difference was significant statistically between the efficacy on the localization above chorda tympani nerve and that on the localization below the nerve in group D (P < 0.01). The efficacy on the localization below chorda tympani nerve was superior to the localization above the nerve. The best intervention time for the treatment of Bell's palsy is in acute stage and resting stage, meaning 1 to 3 weeks after occurrence. All of the 5 treatment programs are advantageous

  14. Tobacco smoking surveillance: is quota sampling an efficient tool for monitoring national trends? A comparison with a random cross-sectional survey.

    Directory of Open Access Journals (Sweden)

    Romain Guignard

    Full Text Available OBJECTIVES: It is crucial for policy makers to monitor the evolution of tobacco smoking prevalence. In France, this monitoring is based on a series of cross-sectional general population surveys, the Health Barometers, conducted every five years and based on random samples. A methodological study has been carried out to assess the reliability of a monitoring system based on regular quota sampling surveys for smoking prevalence. DESIGN / OUTCOME MEASURES: In 2010, current and daily tobacco smoking prevalences obtained in a quota survey on 8,018 people were compared with those of the 2010 Health Barometer carried out on 27,653 people. Prevalences were assessed separately according to the telephone equipment of the interviewee (landline phone owner vs "mobile-only", and logistic regressions were conducted in the pooled database to assess the impact of the telephone equipment and of the survey mode on the prevalences found. Finally, logistic regressions adjusted for sociodemographic characteristics were conducted in the random sample in order to determine the impact of the needed number of calls to interwiew "hard-to-reach" people on the prevalence found. RESULTS: Current and daily prevalences were higher in the random sample (respectively 33.9% and 27.5% in 15-75 years-old than in the quota sample (respectively 30.2% and 25.3%. In both surveys, current and daily prevalences were lower among landline phone owners (respectively 31.8% and 25.5% in the random sample and 28.9% and 24.0% in the quota survey. The required number of calls was slightly related to the smoking status after adjustment for sociodemographic characteristics. CONCLUSION: Random sampling appears to be more effective than quota sampling, mainly by making it possible to interview hard-to-reach populations.

  15. Procedure for the determination of uranium on cellulose air-sampling filters by photon-electron-rejecting-alpha-liquid-scintillation spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    McDowell, W.J.; Case, G.N.

    1986-08-01

    A procedure is described for obtaining from cellulose air-sampling filters the total uranium content whether it be in the form of metal, oxide, tetrafluoride or most other salts of uranium. It is demonstrated that the uranium content can be accurately assayed by low-temperature ashing of the filter paper, dissolving the ash in a mixed nitrate-sulfate system, extracting the uranium selectively into a scintillator containing a high-molecular-weight amine sulfate, and counting the extract using a Photon-Electron-Rejecting-Alpha-Liquid-Scintillation (PERALS) spectrometer. 2 refs., 4 figs., 2 tabs.

  16. Histological and radiological evaluation of sintered and non-sintered deproteinized bovine bone substitute materials in sinus augmentation procedures. A prospective, randomized-controlled, clinical multicenter study.

    Science.gov (United States)

    Fienitz, Tim; Moses, Ofer; Klemm, Christoph; Happe, Arndt; Ferrari, Daniel; Kreppel, Matthias; Ormianer, Zeev; Gal, Moti; Rothamel, Daniel

    2017-04-01

    The objective of this study is to histologically and radiologically compare a sintered and a non-sintered bovine bone substitute material in sinus augmentation procedures. Thirty-three patients were included in the clinically controlled randomized multicentre study resulting in a total of 44 treated sinuses. After lateral approach, sinuses were filled with either a sintered (SBM, Alpha Bio's Graft(®)) or a non-sintered (NSBM, Bio Oss(®)) deproteinized bovine bone substitute material. The augmentation sites were radiologically assessed before and immediately after the augmentation procedure as well as prior to implant placement. Bone trephine biopsies for histological analysis were harvested 6 months after augmentation whilst preparing the osteotomies for implant placement. Healing was uneventful in all patients. After 6 months, radiological evaluation of 43 sinuses revealed a residual augmentation height of 94.65 % (±2.74) for SBM and 95.76 % (±2.15) for NSBM. One patient left the study for personal reasons. Histological analysis revealed a percentage of new bone of 29.71 % (±13.67) for SBM and 30.57 % (±16.07) for NSBM. Residual bone substitute material averaged at 40.68 % (±16.32) for SBM compared to 43.43 % (±19.07) for NSBM. All differences between the groups were not statistically significant (p > 0.05, Student's t test). Both xenogeneic bone substitute materials showed comparable results regarding new bone formation and radiological height changes in external sinus grafting procedures. Both bone substitute materials allow for a predictable new bone formation following sinus augmentation procedures.

  17. Treatment of gastroesophageal reflux disease using radiofrequency ablation (Stretta procedure): An interim analysis of a randomized trial.

    Science.gov (United States)

    Kalapala, Rakesh; Shah, Harshal; Nabi, Zaheer; Darisetty, Santosh; Talukdar, Rupjyoti; Nageshwar Reddy, D

    2017-09-01

    Gastroesophageal reflux disease (GERD) is the most common chronic gastrointestinal disorder, affecting one third of the population worldwide. Recently, there has been a renewed interest in Stretta therapy in view of potential long-term side effects of PPIs and the durability of relief with fundoplication. Prospective randomized study comparing the Stretta treatment with controls receiving PPIs. Patient (> 18 years, n = 20) with symptoms of heartburn, regurgitation, abnormal esophageal acid exposure (≥ 4%), and endoscopically confirmed esophagitis were included into the study. The primary measure was improvement in quality of life (QOL) and decrease in the frequency and severity of GERD symptoms. The mean age of the patients was 39 (± 15) years and controls were 34 (± 11) years. Three months after Stretta, 80% reported improvement in QOL compared to 40% in the control group. At the end of 3 months, significant (p < 0.05) improvement in GERD symptom score for heartburn, regurgitation, chest pain, and cough compared with the control group was observed. After Stretta treatment, 60% of the patients were free of PPIs whereas there was no change in the control group. Almost 80% of the patients on Stretta treatment were satisfied with the treatment compared to 30% of the patients in the control group. Stretta was effective in the short-term for the management of GERD.

  18. A multicenter randomized controlled trial comparing absorbable barbed sutures versus conventional absorbable sutures for dermal closure in open surgical procedures.

    Science.gov (United States)

    Rubin, J Peter; Hunstad, Joseph P; Polynice, Alain; Gusenoff, Jeffrey A; Schoeller, Thomas; Dunn, Raymond; Walgenbach, Klaus J; Hansen, Juliana E

    2014-02-01

    Barbed sutures were developed to reduce operative time and improve security of wound closure. The authors compare absorbable barbed sutures (V-Loc, Covidien, Mansfield, Massachusetts) with conventional (smooth) absorbable sutures for soft tissue approximation. A prospective multicenter randomized study comparing barbed sutures with smooth sutures was undertaken between August 13, 2009, and January 31, 2010, in 241 patients undergoing abdominoplasty, mastopexy, and reduction mammaplasty. Each patient received barbed sutures on 1 side of the body, with deep dermal sutures eliminated or reduced. Smooth sutures with deep dermal and subcuticular closure were used on the other side as a control. The primary endpoint was dermal closure time. Safety was assessed through adverse event reporting through a 12-week follow-up. A total of 229 patients were ultimately treated (115 with slow-absorbing polymer and 114 with rapid-absorbing polymer). Mean dermal closure time was significantly quicker with the barbed suture compared with the smooth suture (12.0 vs 19.2 minutes; Psutures. The rapid-absorbing barbed suture showed a complication profile equivalent to the smooth suture, while the slow-absorbing barbed suture had a higher incidence of minor suture extrusion. Barbed sutures enabled faster dermal closure quicker than smooth sutures, with a comparable complication profile. 1.

  19. Do placebo effects associated with sham osteopathic procedure occur in newborns? Results of a randomized controlled trial.

    Science.gov (United States)

    Martelli, Marta; Cardinali, Lucia; Barlafante, Gina; Pizzolorusso, Gianfranco; Renzetti, Cinzia; Cerritelli, Francesco

    2014-04-01

    Placebo effect has been largely studied and debated in medicine. Research focused mainly on children and adults but not on newborns. In osteopathy, few studies documented this effect and no research has been conducted in newborns. To assess the presence of placebo effect in newborns using sham osteopathic manipulative treatment. Randomized control trial. Neonatal Intensive Care Unit in Italy. Two groups (103 patients each) of preterm infants aged 29-36 weeks without medical complications received routine pediatric care and osteopathic sham therapy was administrated to the study group only for the entire period of hospitalization. Primary end point was the mean reduction of length of stay at discharge. Secondary objective was the change in daily weight gain. 206 newborns entered the study. No difference between sham and control group was found for the primary outcome length of stay (30.0±20.3; 28.8±18.9; p=0.70). Multivariate analysis showed no difference between study and control group on length of stay. A negative association was found for gestational age (-2.33; 95% CI -3.81 to -0.85; p=0.002), birth weight (-0.01; 95% CI -0.02 to -0.01; pplacebo effect on newborns. Further discussions are opened concerning the age when placebo effect starts. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Prospective randomized trial comparing Billroth I and Roux-en-Y procedures after distal gastrectomy for gastric carcinoma.

    Science.gov (United States)

    Ishikawa, Makoto; Kitayama, Joji; Kaizaki, Shoichi; Nakayama, Hiroshi; Ishigami, Hironori; Fujii, Shin; Suzuki, Hiroyuki; Inoue, Tomomi; Sako, Akihiro; Asakage, Masahiro; Yamashita, Hiroharu; Hatono, Kenji; Nagawa, Hirokazu

    2005-11-01

    To determine the clinical efficacy of Roux-en-Y reconstruction (RY) after distal gastrectomy, we compared postoperative outcomes of patients who underwent RY or conventional Billroth I reconstruction (B-I). A total of 50 patients were prospectively randomized to either B-I or RY reconstruction, and complications, postoperative course, and nutritional status were compared. Bile reflux and inflammation in the remnant stomach and lower esophagus were evaluated by postoperative follow-up endoscopy at 6 months. Operative time and blood loss as well as postoperative nutrition did not show significant differences between the two groups. As anticipated, 5 of 24 patients with RY reconstruction developed gastrojejunal stasis in the early postoperative period, which led to a longer postoperative hospital stay as compared with the B-I group (mean +/- S.D; B-I; 19.0 +/- 6.2, RY; 31.8 +/- 21.7 days) (P gastritis, but it did not prevent esophagitis. Because RY reconstruction induces the frequent complication of Roux-en-Y stasis, causing longer postoperative hospital stay, this method has limited advantages over B-I anastomosis after distal gastrectomy.

  1. Isolation and preconcentration of Cd(II) from environmental samples using polypropylene porous membrane in a hollow fiber renewal liquid membrane extraction procedure and determination by FAAS.

    Science.gov (United States)

    Luciano, Raquel Medeiros; Bedendo, Gizelle Cristina; Carletto, Jeferson Schneider; Carasek, Eduardo

    2010-05-15

    The use of polypropylene porous membrane in a hollow fiber renewal liquid membrane (HFRLM) procedure for determination of Cd(II) in water samples was assessed. Ammonium O,O-diethyl dithiophosphate (DDTP) was used to complex cadmium (II) in an acid medium to obtain a neutral hydrophobic complex. The organic solvent introduced to the sample extracts this complex from the aqueous solution and carries it over the polypropylene membrane porous. The organic solvent is immobilized inside the polypropylene membrane porous, leading to an homogeneous phase. The complex strips the lumen of the membrane where, at higher pH, the complex Cd-DDTP is broken down and Cd(II) is released into the stripping phase. EDTA was used to complex the cadmium (II), helping to trap the analyte in the stripping phase. The optimized variables were: sample pH, DDTP concentration, stripping pH, EDTA concentration, extraction temperature and time, extractor solvent and addition of salt to saturate the sample. The sample volume used was 15 mL and the stripping volume was 165 microL. The analyte enrichment factor was 107, limit of detection 1.5 microg L(-1), relative standard deviation 4.0% (15 microg L(-1), n=7) and the working linear range 5-30 microg L(-1). Copyright (c) 2009 Elsevier B.V. All rights reserved.

  2. Automated large-volume sample stacking procedure to detect labeled peptides at picomolar concentration using capillary electrophoresis and laser-induced fluorescence detection.

    Science.gov (United States)

    Siri, Nathalie; Riolet, Pierre; Bayle, Christophe; Couderc, François

    2003-08-05

    We have developed an automated large-volume sample stacking (LVSS) procedure to detect fluorescein isothiocyanate-labeled peptides in the picomolar range. The injection duration is 10 min at 50 mbar to fill 62% of the capillary volume to the detection cell. The calculated limit of detection (S/N=3), filling 1% of the capillary volume, is 74 pM for bradykinin and 45 pM for L-enkephalin with samples diluted in water and analyzed in a 50 mM borate buffer, pH 9.2. With the automated LVSS system, the limits of detection are 7 pM for bradykinin, 3 pM for L-enkephalin and 2 pM for substance P. LVSS is shown to be quantitative from 500 to 10 pM.

  3. The role of topical vitamin A in promoting healing in surface refractive procedures: a prospective randomized controlled study

    Directory of Open Access Journals (Sweden)

    Chelala E

    2013-09-01

    Full Text Available Elias Chelala,1 Ali Dirani,1 Ali Fadlallah,1 Sharbel Fahd21Saint Joseph University, Faculty of Medicine, Beirut, Lebanon; 2Ophthalmic Consultant of Beirut, Chairman Ophthalmology, Lebanese American University, Beirut, LebanonAim: To evaluate the effect of topical vitamin A supplementation on corneal re-epithelialization time, postoperative pain, visual acuity, and haze following photorefractive keratectomy (PRK.Patients and methods: This prospective study included 32 patients. For each patient, one eye was randomized to the vitamin A group and the fellow eye to the non-vitamin A group (control group. Eyes in the vitamin A group received perioperative topical vitamin A (retinol palmitate, 250 IU/g VitAPOS eye ointment [AFT Pharmaceuticals Pty, Ltd, Sydney, NSW, Australia] in addition to the classic treatment for PRK. Clinical outcomes were evaluated up to 3 months after PRK.Results: There was no difference in the mean time to complete healing between the vitamin A group and the control group (3.36 ± 0.6 days in the control group; 3.42 ± 0.7 days in the vitamin A group; P = 0.854. Mean postoperative pain at the 48-hour visit was 4.35 ± 1.42 over 10 in the control group, and 4.42 ± 1.37 over 10 in the vitamin A group, with no difference between the two groups (P = 0.589. Subepithelial haze evaluated at 3 months postoperatively did not differ between the two groups (P = 0.960. Also, visual and refractive outcomes were not different between the two groups 3 months postoperatively.Conclusion: Topical vitamin A supplementation did not affect re-epithelialization time, postoperative pain, corneal haze formation, or visual outcomes after PRK.Keywords: photorefractive keratectomy, topical vitamin A, corneal re-epithelialization

  4. Differentiating intraprofessional attitudes toward paradigms in health care delivery among chiropractic factions: results from a randomly sampled survey

    Science.gov (United States)

    2014-01-01

    Background As health care has increased in complexity and health care teams have been offered as a solution, so too is there an increased need for stronger interprofessional collaboration. However the intraprofessional factions that exist within every profession challenge interprofessional communication through contrary paradigms. As a contender in the conservative spinal health care market, factions within chiropractic that result in unorthodox practice behaviours may compromise interprofessional relations and that profession’s progress toward institutionalization. The purpose of this investigation was to quantify the professional stratification among Canadian chiropractic practitioners and evaluate the practice perceptions of those factions. Methods A stratified random sample of 740 Canadian chiropractors was surveyed to determine faction membership and how professional stratification could be related to views that could be considered unorthodox to current evidence-based care and guidelines. Stratification in practice behaviours is a stated concern of mainstream medicine when considering interprofessional referrals. Results Of 740 deliverable questionnaires, 503 were returned for a response rate of 68%. Less than 20% of chiropractors (18.8%) were aligned with a predefined unorthodox perspective of the conditions they treat. Prediction models suggest that unorthodox perceptions of health practice related to treatment choices, x-ray use and vaccinations were strongly associated with unorthodox group membership (X2 =13.4, p = 0.0002). Conclusion Chiropractors holding unorthodox views may be identified based on response to specific beliefs that appear to align with unorthodox health practices. Despite continued concerns by mainstream medicine, only a minority of the profession has retained a perspective in contrast to current scientific paradigms. Understanding the profession’s factions is important to the anticipation of care delivery when considering

  5. Cluster analysis of commercial samples of Bauhinia spp. using HPLC-UV/PDA and MCR-ALS/PCA without peak alignment procedure.

    Science.gov (United States)

    Ardila, Jorge Armando; Funari, Cristiano Soleo; Andrade, André Marques; Cavalheiro, Alberto José; Carneiro, Renato Lajarim

    2015-01-01

    Bauhinia forficata Link. is recognised by the Brazilian Health Ministry as a treatment of hypoglycemia and diabetes. Analytical methods are useful to assess the plant identity due the similarities found in plants from Bauhinia spp. HPLC-UV/PDA in combination with chemometric tools is an alternative widely used and suitable for authentication of plant material, however, the shifts of retention times for similar compounds in different samples is a problem. To perform comparisons between the authentic medicinal plant (Bauhinia forficata Link.) and samples commercially available in drugstores claiming to be "Bauhinia spp. to treat diabetes" and to evaluate the performance of multivariate curve resolution - alternating least squares (MCR-ALS) associated to principal component analysis (PCA) when compared to pure PCA. HPLC-UV/PDA data obtained from extracts of leaves were evaluated employing a combination of MCR-ALS and PCA, which allowed the use of the full chromatographic and spectrometric information without the need of peak alignment procedures. The use of MCR-ALS/PCA showed better results than the conventional PCA using only one wavelength. Only two of nine commercial samples presented characteristics similar to the authentic Bauhinia forficata spp., considering the full HPLC-UV/PDA data. The combination of MCR-ALS and PCA is very useful when applied to a group of samples where a general alignment procedure could not be applied due to the different chromatographic profiles. This work also demonstrates the need of more strict control from the health authorities regarding herbal products available on the market. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Development of an in vitro Test Procedure to Determine the Direct Infrared A Protection of Sunscreens and Non-Cosmetic Samples.

    Science.gov (United States)

    Quistorf, Jan Carlos; Kockott, Dieter; Garbe, Birgit; Heinrich, Ulrike; Tronnier, Hagen; Braun, Nicole

    2017-01-01

    Every day human skin is exposed to infrared A (IRA) radiation as part of the natural sun rays. As IRA radiation accounts for around one third of the solar radiation, it has gained great attention concerning its effects on the human body and skin. In the past few years it has been discussed controversially whether IRA radiation (of solar origin) is harmful or not. Nonetheless, there are several sunscreens on the German market that claim IRA protection for themselves. The present study seeks to find an experimental set-up and a test procedure for the determination and quantification of direct IRA protection (realized via reflection or absorption of the IRA radiation), since to our knowledge these do not yet exist. In this study we proved the usability of a set-up consisting of a light source, an IRA-transmissible filter system and a sensor unit, for the determination and quantification of the IRA protection of cosmetic and non-cosmetic samples. The applicability of the IRA emission of the light source, the spectral detector, transmissivity of the filter systems and the sample carriers could be validated. This experimental set-up can be used as an in vitro test procedure for the determination of direct IRA protection. © 2017 S. Karger AG, Basel.

  7. Percutaneous Sacroiliac Screw Placement: A Prospective Randomized Comparison of Robot-assisted Navigation Procedures with a Conventional Technique.

    Science.gov (United States)

    Wang, Jun-Qiang; Wang, Yu; Feng, Yun; Han, Wei; Su, Yong-Gang; Liu, Wen-Yong; Zhang, Wei-Jun; Wu, Xin-Bao; Wang, Man-Yi; Fan, Yu-Bo

    2017-11-05

    Sacroiliac (SI) screw fixation is a demanding technique, with a high rate of screw malposition due to the complex pelvic anatomy. TiRobot™ is an orthopedic surgery robot which can be used for SI screw fixation. This study aimed to evaluate the accuracy of robot-assisted placement of SI screws compared with a freehand technique. Thirty patients requiring posterior pelvic ring stabilization were randomized to receive freehand or robot-assisted SI screw fixation, between January 2016 and June 2016 at Beijing Jishuitan Hospital. Forty-five screws were placed at levels S1 and S2. In both methods, the primary end point screw position was assessed and classified using postoperative computed tomography. Fisher's exact probability test was used to analyze the screws' positions. Secondary end points, such as duration of trajectory planning, surgical time after reduction of the pelvis, insertion time for guide wire, number of guide wire attempts, and radiation exposure without pelvic reduction, were also assessed. Twenty-three screws were placed in the robot-assisted group and 22 screws in the freehand group; no postoperative complications or revisions were reported. The excellent and good rate of screw placement was 100% in the robot-assisted group and 95% in the freehand group. The P value (0.009) showed the same superiority in screw distribution. The fluoroscopy time after pelvic reduction in the robot-assisted group was significantly shorter than that in the freehand group (median [Q1, Q3]: 6.0 [6.0, 9.0] s vs. median [Q1, Q3]: 36.0 [21.5, 48.0] s; χ2 = 13.590, respectively, P robot-assisted group than that for the freehand group (median [Q1, Q3]: 2.0 [2.0, 2.7] min vs. median [Q1, Q3]: 19.0 [15.5, 45.0] min; χ2 = 20.952, respectively, P robot-assisted group was significantly less than that in the freehand group (median [Q1, Q3]: 1.0 [1.0,1.0] time vs. median [Q1, Q3]: 7.0 [1.0, 9.0] times; χ2 = 15.771, respectively, P robot-assisted technique was superior to that of

  8. Gas chromatographic-mass spectrometric analysis of urinary volatile organic metabolites: Optimization of the HS-SPME procedure and sample storage conditions.

    Science.gov (United States)

    Živković Semren, Tanja; Brčić Karačonji, Irena; Safner, Toni; Brajenović, Nataša; Tariba Lovaković, Blanka; Pizent, Alica

    2018-01-01

    Non-targeted metabolomics research of human volatile urinary metabolome can be used to identify potential biomarkers associated with the changes in metabolism related to various health disorders. To ensure reliable analysis of urinary volatile organic metabolites (VOMs) by gas chromatography-mass spectrometry (GC-MS), parameters affecting the headspace-solid phase microextraction (HS-SPME) procedure have been evaluated and optimized. The influence of incubation and extraction temperatures and times, coating fibre material and salt addition on SPME efficiency was investigated by multivariate optimization methods using reduced factorial and Doehlert matrix designs. The results showed optimum values for temperature to be 60°C, extraction time 50min, and incubation time 35min. The proposed conditions were applied to investigate urine samples' stability regarding different storage conditions and freeze-thaw processes. The sum of peak areas of urine samples stored at 4°C, -20°C, and -80°C up to six months showed a time dependent decrease over time although storage at -80°C resulted in a slight non-significant reduction comparing to the fresh sample. However, due to the volatile nature of the analysed compounds, more than two cycles of freezing/thawing of the sample stored for six months at -80°C should be avoided whenever possible. Copyright © 2017 Elsevier B.V. All rights reserved.

  9. Utility of recorded guided imagery and relaxing music in reducing patient pain and anxiety, and surgeon anxiety, during cutaneous surgical procedures: A single-blinded randomized controlled trial.

    Science.gov (United States)

    Alam, Murad; Roongpisuthipong, Wanjarus; Kim, Natalie A; Goyal, Amita; Swary, Jillian H; Brindise, Renata T; Iyengar, Sanjana; Pace, Natalie; West, Dennis P; Polavarapu, Mahesh; Yoo, Simon

    2016-09-01

    Guided imagery and music can reportedly reduce pain and anxiety during surgery, but no comparative study has been performed for cutaneous surgery to our knowledge. We sought to determine whether short-contact recorded guided imagery or relaxing music could reduce patient pain and anxiety, and surgeon anxiety, during cutaneous surgical procedures. Subjects were adults undergoing excisional surgery for basal and squamous cell carcinoma. Randomization was to guided imagery (n = 50), relaxing music (n = 54), or control group (n = 51). Primary outcomes were pain and anxiety measured using visual analog scale and 6-item short-form of the State-Trait Anxiety Inventory, respectively. Secondary outcomes were anxiety of surgeons measured by the 6-item short-form of the State-Trait Anxiety Inventory and physical stress of patients conveyed by vital signs, respectively. There were no significant differences in subjects' pain, anxiety, blood pressure, and pulse rate across groups. In the recorded guided imagery and the relaxing music group, surgeon anxiety was significantly lower than in the control group. Patients could not be blinded. Short-contact recorded guided imagery and relaxing music appear not to reduce patient pain and anxiety during excisional procedures under local anesthetic. However, surgeon anxiety may be reduced when patients are listening to such recordings. Copyright © 2016 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.

  10. Effect of periprocedural amiodarone on procedure outcome in patients with longstanding persistent atrial fibrillation undergoing extended pulmonary vein antrum isolation: results from a randomized study (SPECULATE).

    Science.gov (United States)

    Mohanty, Sanghamitra; Di Biase, Luigi; Mohanty, Prasant; Trivedi, Chintan; Santangeli, Pasquale; Bai, Rong; Burkhardt, John David; Gallinghouse, Joseph G; Horton, Rodney; Sanchez, Javier E; Hranitzky, Patrick M; Zagrodzky, Jason; Al-Ahmad, Amin; Pelargonio, Gemma; Lakkireddy, Dhanunjay; Reddy, Madhu; Forleo, Giovanni; Rossillo, Antonio; Themistoclakis, Sakis; Hongo, Richard; Beheiry, Salzwa; Casella, Michela; Dello Russo, Antonio; Tondo, Claudio; Natale, Andrea

    2015-03-01

    The impact of amiodarone on ablation outcome in longstanding persistent atrial fibrillation (LSPAF) patients is not known yet. The purpose of this study was to assess the effect of amiodarone on procedural-outcomes in LSPAF patients undergoing catheter ablation. We enrolled 112 LSPAF patients on amiodarone and scheduled to undergo atrial fibrillation (AF) ablation. Patients were randomized to amiodarone discontinuation 4 months before ablation (group 1, n = 56) and a control group (group 2, n = 56) in which ablation was performed without amiodarone discontinuation. All patients underwent pulmonary vein (PV) antrum and posterior wall isolation, defragmentation and extra PV triggers ablation. Patients were followed up for recurrence for 32 ± 8 months post-ablation. Repeat procedures in all recurrent patients were performed off amiodarone. During ablation, AF termination was more frequent in group 2 compared to group 1 [44 (79%) vs 32 (57%), P = .015]. After high-dosage isoproterenol, more non-PV triggers were disclosed in group 1 compared to group 2 (42 [75%] vs 24 [43%] respectively, P amiodarone was associated with higher organization rate and lower radiofrequency ablation rate. However, masking non-PV triggers increased the late recurrence rate. Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.

  11. Functional exercise capacity and lung function in patients undergoing an early rehabilitation program after the Nuss procedure: a randomized controlled trial.

    Science.gov (United States)

    Linhares, Sâmia Georgia Dantas; Pereira, João Carlos Das-Neves; Fernades, Paulo Manuel Pêgo; de Campos, José Ribas Milanez

    2017-01-01

    The aim of this study was to compare the functional exercise capacity and the lung function among patients undergoing early rehabilitation with those submitted to the conventional care after pectus excavatum repair using the Nuss procedure. Patients were randomly allocated to the early rehabilitation group (ERG) who started rehabilitation after surgery and the group of the conventional care (CG) received routine care of the institution. They were evaluated before surgery (preoperative) and in hospital discharge day (postoperative). Forty patients were evaluated, twenty in each group. All patients presented a significant reduction in FVC, FEV1, and PEF in the postoperative period, there was no statistically significant difference between groups. There was significant different in postoperative functional exercise capacity between the ERG and CG (506.26 ± 66.54 vs 431.11 ± 75.61, p = 0.02) and the difference between distance walked in the preoperative and postoperative period was lower in the ERC than in the CG (76.57 ± 49.41 vs 166.82 ± 70.13, p rehabilitation after the Nuss procedure presented a better postoperative functional exercise capacity in hospital discharge day compared with patients in the conventional group, with no difference in lung function between groups.

  12. Direct solid sample analysis with graphite furnace atomic absorption spectrometry—a fast and reliable screening procedure for the determination of inorganic arsenic in fish and seafood.

    Science.gov (United States)

    Zmozinski, Ariane V; Llorente-Mirandes, Toni; Damin, Isabel C F; López-Sánchez, José F; Vale, Maria Goreti R; Welz, Bernhard; Silva, Márcia M

    2015-03-01

    Direct solid sample analysis with graphite furnace atomic absorption spectrometry (SS-GF AAS) was investigated initially with the intention of developing a method for the determination of total As in fish and other seafood. A mixture of 0.1% Pd+0.06% Mg+0.06% Triton X-100 was used as the chemical modifier, added in solution over the solid samples, making possible the use of pyrolysis and atomization temperatures of 1200 °C and 2400 °C, respectively. The sample mass had to be limited to 0.25 mg, as the integrated absorbance did not increase further with increasing sample mass. Nevertheless, the recovery of As from several certified reference materials was of the order of 50% lower than the certified value. Strong molecular absorption due to the phosphorus monoxide molecule (PO) was observed with high-resolution continuum source AAS (HR CS AAS), which, however, did not cause any spectral interference. A microwave-assisted digestion with HNO3/H2O2 was also investigated to solve the problem; however, the results obtained for several certified reference materials were statistically not different from those found with direct SS-GF AAS. Accurate values were obtained using inductively coupled plasma mass spectrometry (ICP-MS) to analyze the digested samples, which suggested that organic As compounds are responsible for the low recoveries. HPLC-ICP-MS was used to determine the arsenobetaine (AB) concentration. Accurate results that were not different from the certified values were obtained when the AB concentration was added to the As concentration found by SS-GF AAS for most certified reference materials (CRM) and samples, suggesting that SS-GF AAS could be used as a fast screening procedure for inorganic As determination in fish and seafood. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Design of a randomized controlled trial to compare debridement to observation of chondral lesions encountered during partial meniscectomy: The ChAMP (Chondral Lesions And Meniscus Procedures) Trial.

    Science.gov (United States)

    Bisson, Leslie J; Kluczynski, Melissa A; Wind, William M; Fineberg, Marc S; Bernas, Geoffrey A; Rauh, Michael A; Marzo, John M; Smolinski, Robert J

    2015-11-01

    Few studies have examined whether chondral lesions encountered in patients undergoing meniscectomy should be surgically treated. The primary aim of the ChAMP (Chondral Lesions And Meniscus Procedures) Trial is to determine whether there is a difference in knee pain between patients undergoing debridement versus observation of chondral lesions encountered during arthroscopic meniscectomy. This paper describes the rationale and study design for the ChAMP Trial. The ChAMP Trial is a randomized controlled trial of patients aged 30 and older undergoing partial meniscectomy and randomly allocated to debridement (CL-Deb, N=98) or observation (CL-Obs, N=92) of chondral lesions identified during surgery and deemed to be significant (Outerbridge Grade II-IV). Patients and data collectors were unaware of treatment allocation until completion of the study. Patients with surgically insignificant (Outerbridge Grade I) chondral lesions or no chondral lesions were included as a third non-randomized comparison group (NoCL, N=76). The primary outcome is the difference in knee pain assessed by WOMAC (Western Ontario and McMaster Universities Arthritis Index) between the CL-Deb and CL-Obs groups at 1-year after surgery. Secondary outcomes include 1-year differences in additional measures of knee pain, function, symptoms, activity, and quality of life assessed by the WOMAC, KOOS (Knee Injury and Osteoarthritis Outcome Score), visual analog pain scale, and physical exam; as well as general health assessed with the SF-36 (Short-form Health Survey). Increased intraoperative costs associated with the addition of chondral debridement will also be assessed. This study will add to the scant literature regarding management of chondral lesions in patients undergoing meniscectomy and might provide treatment guidance for clinicians and their patients. Copyright © 2015 Elsevier Inc. All rights reserved.

  14. Distribution of peak expiratory flow variability by age, gender and smoking habits in a random population sample aged 20-70 yrs

    NARCIS (Netherlands)

    Boezen, H M; Schouten, J. P.; Postma, D S; Rijcken, B

    1994-01-01

    Peak expiratory flow (PEF) variability can be considered as an index of bronchial lability. Population studies on PEF variability are few. The purpose of the current paper is to describe the distribution of PEF variability in a random population sample of adults with a wide age range (20-70 yrs),

  15. From Planning to Implementation: An Examination of Changes in the Research Design, Sample Size, and Precision of Group Randomized Trials Launched by the Institute of Education Sciences

    Science.gov (United States)

    Spybrook, Jessaca; Puente, Anne Cullen; Lininger, Monica

    2013-01-01

    This article examines changes in the research design, sample size, and precision between the planning phase and implementation phase of group randomized trials (GRTs) funded by the Institute of Education Sciences. Thirty-eight GRTs funded between 2002 and 2006 were examined. Three studies revealed changes in the experimental design. Ten studies…

  16. Evaluating effectiveness of down-sampling for stratified designs and unbalanced prevalence in Random Forest models of tree species distributions in Nevada

    Science.gov (United States)

    Elizabeth A. Freeman; Gretchen G. Moisen; Tracy S. Frescino

    2012-01-01

    Random Forests is frequently used to model species distributions over large geographic areas. Complications arise when data used to train the models have been collected in stratified designs that involve different sampling intensity per stratum. The modeling process is further complicated if some of the target species are relatively rare on the landscape leading to an...

  17. Changes in prevalence of, and risk factors for, lameness in random samples of English sheep flocks: 2004-2013.

    Science.gov (United States)

    Winter, Joanne R; Kaler, Jasmeet; Ferguson, Eamonn; KilBride, Amy L; Green, Laura E

    2015-11-01

    The aims of this study were to update the prevalence of lameness in sheep in England and identify novel risk factors. A total of 1260 sheep farmers responded to a postal survey. The survey captured detailed information on the period prevalence of lameness from May 2012-April 2013 and the prevalence and farmer naming of lesions attributable to interdigital dermatitis (ID), severe footrot (SFR), contagious ovine digital dermatitis (CODD) and shelly hoof (SH), management and treatment of lameness, and farm and flock details. The global mean period prevalence of lameness fell between 2004 and 2013 from 10.6% to 4.9% and the geometric mean period prevalence of lameness fell from 5.4% (95% CL: 4.7%-6.0%) to 3.5% (95% CI: 3.3%-3.7%). In 2013, more farmers were using vaccination and antibiotic treatment for ID and SFR and fewer farmers were using foot trimming as a routine or therapeutic treatment than in 2004. Two over-dispersed Poisson regression models were developed with the outcome the period prevalence of lameness, one investigated associations with farmer estimates of prevalence of the four foot lesions and one investigated associations with management practices to control and treat lameness and footrot. A prevalence of ID>10%, SFR>2.5% and CODD>2.5% were associated with a higher prevalence of lameness compared with those lesions being absent, however, the prevalence of SH was not associated with a change in risk of lameness. A key novel management risk associated with higher prevalence of lameness was the rate of feet bleeding/100 ewes trimmed/year. In addition, vaccination of ewes once per year and selecting breeding replacements from never-lame ewes were associated with a decreased risk of lameness. Other factors associated with a lower risk of lameness for the first time in a random sample of farmers and a full risk model were: recognising lameness in sheep at locomotion score 1 compared with higher scores, treatment of the first lame sheep in a group compared

  18. Nutritional status and falls in community-dwelling older people: a longitudinal study of a population-based random sample.

    Science.gov (United States)

    Chien, Ming-Hung; Guo, How-Ran

    2014-01-01

    Falls are common in older people and may lead to functional decline, disability, and death. Many risk factors have been identified, but studies evaluating effects of nutritional status are limited. To determine whether nutritional status is a predictor of falls in older people living in the community, we analyzed data collected through the Survey of Health and Living Status of the Elderly in Taiwan (SHLSET). SHLSET include a series of interview surveys conducted by the government on a random sample of people living in community dwellings in the nation. We included participants who received nutritional status assessment using the Mini Nutritional Assessment Taiwan Version 2 (MNA-T2) in the 1999 survey when they were 53 years or older and followed up on the cumulative incidence of falls in the one-year period before the interview in the 2003 survey. At the beginning of follow-up, the 4440 participants had a mean age of 69.5 (standard deviation= 9.1) years, and 467 participants were "not well-nourished," which was defined as having an MNA-T2 score of 23 or less. In the one-year study period, 659 participants reported having at least one fall. After adjusting for other risk factors, we found the associated odds ratio for falls was 1.73 (95% confidence interval, 1.23, 2.42) for "not well-nourished," 1.57 (1.30, 1.90) for female gender, 1.03 (1.02, 1.04) for one-year older, 1.55 (1.22, 1.98) for history of falls, 1.34 (1.05, 1.72) for hospital stay during the past 12 months, 1.66 (1.07, 2.58) for difficulties in activities of daily living, and 1.53 (1.23, 1.91) for difficulties in instrumental activities of daily living. Nutritional status is an independent predictor of falls in older people living in the community. Further studies are warranted to identify nutritional interventions that can help prevent falls in the elderly.

  19. Processes and procedures for a worldwide biological samples distribution; product assurance and logistic activities to support the mice drawer system tissue sharing event

    Science.gov (United States)

    Benassai, Mario; Cotronei, Vittorio

    The Mice Drawer System (MDS) is a scientific payload developed by the Italian Space Agency (ASI), it hosted 6 mice on the International Space Station (ISS) and re-entered on ground on November 28, 2009 with the STS 129 at KSC. Linked to the MDS experiment, a Tissue Sharing Program (TSP), was developed in order to make available to 16 Payload Investigators (PI) (located in USA, Canada, EU -Italy, Belgium and Germany -and Japan) the biological samples coming from the mice. ALTEC SpA (a PPP owned by ASI, TAS-I and local institutions) was responsible to support the logistics aspects of the MDS samples for the first MDS mission, in the frame of Italian Space Agency (ASI) OSMA program (OSteoporosis and Muscle Atrophy). The TSP resulted in a complex scenario, as ASI, progressively, extended the original OSMA Team also to researchers from other ASI programs and from other Agencies (ESA, NASA, JAXA). The science coordination was performed by the University of Genova (UNIGE). ALTEC has managed all the logistic process with the support of a specialized freight forwarder agent during the whole shipping operation phases. ALTEC formalized all the steps from the handover of samples by the dissection Team to the packaging and shipping process in a dedicated procedure. ALTEC approached all the work in a structured way, performing: A study of the aspects connected to international shipments of biological samples. A coopera-tive work with UNIGE/ASI /PIs to identify all the needs of the various researchers and their compatibility. A complete revision and integration of shipment requirements (addresses, tem-peratures, samples, materials and so on). A complete definition of the final shipment scenario in terms of boxes, content, refrigerant and requirements. A formal approach to identification and selection of the most suited and specialized Freight Forwarder. A clear identification of all the processes from sample dissection by PI Team, sample processing, freezing, tube preparation

  20. Inference for Noisy Samples

    Directory of Open Access Journals (Sweden)

    I. A. Ahmad

    2012-07-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE In the current work, some well-known inference procedures including testing and estimation are adjusted to accommodate noisy data that lead to nonidentically distributed sample.  The main two cases addressed are the Poisson and the normal distributions. Both one and two sample cases are addressed.  Other cases including the exponential and the Pareto distributions are briefly mentioned.  In the Poisson case, the situation when the sample size is random is mentioned.

  1. A Randomized Controlled Trial to Compare e-Feedback Versus "Standard" Face-to-Face Verbal Feedback to Improve the Acquisition of Procedural Skill.

    Science.gov (United States)

    Al-Jundi, Wissam; Elsharif, Mohamed; Anderson, Melanie; Chan, Phillip; Beard, Jonathan; Nawaz, Shah

    Constructive feedback plays an important role in learning during surgical training. Standard feedback is usually given verbally following direct observation of the procedure by a trained assessor. However, such feedback requires the physical presence of expert faculty members who are usually busy and time-constrained by clinical commitments. We aim to evaluate electronic feedback (e-feedback) after video observation of surgical suturing in comparison with standard face-to-face verbal feedback. A prospective, blinded, randomized controlled trial comparing e-feedback with standard verbal feedback was carried out in February 2015 using a validated pro formas for assessment. The study participants were 38 undergraduate medical students from the University of Sheffield, UK. They were recorded on video performing the procedural skill, completed a self-evaluation form, and received e-feedback on the same day (group 1); observed directly by an assessor, invited to provide verbal self-reflection, and then received standard verbal feedback (group 2). In both groups, the feedback was provided after performing the procedure. The participants returned 2 days later and performed the same skill again. Poststudy questionnaire was used to assess the acceptability of each feedback among the participants. Overall, 19 students in group 1 and 18 students in group 2 completed the study. Although there was a significant improvement in the overall mean score on the second performance of the task for all participants (first performance mean 11.59, second performance mean 15.95; p ≤ 0.0001), there was no difference in the overall mean improvement score between group 1 and group 2 (4.74 and 3.94, respectively; p = 0.49). The mean overall scores for the e-feedback group at baseline recorded by 2 independent investigators showed good agreement (mean overall scores of 12.84 and 11.89; Cronbach α = 0.86). Poststudy questionnaire demonstrated that both e-feedback and standard verbal feedback

  2. Frontally eluted components procedure with thin layer chromatography as a mode of sample preparation for high performance liquid chromatography quantitation of acetaminophen in biological matrix.

    Science.gov (United States)

    Klimek-Turek, A; Sikora, M; Rybicki, M; Dzido, T H

    2016-03-04

    A new concept of using thin-layer chromatography to sample preparation for the quantitative determination of solute/s followed by instrumental techniques is presented Thin-layer chromatography (TLC) is used to completely separate acetaminophen and its internal standard from other components (matrix) and to form a single spot/zone containing them at the solvent front position (after the final stage of the thin-layer chromatogram development). The location of the analytes and internal standard in the solvent front zone allows their easy extraction followed by quantitation by HPLC. The exctraction procedure of the solute/s and internal standard can proceed from whole solute frontal zone or its part without lowering in accuracy of quantitative analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Stages of change of the readiness to quit smoking among a random sample of minority Arab male smokers in Israel.

    Science.gov (United States)

    Daoud, Nihaya; Hayek, Samah; Sheikh Muhammad, Ahmad; Abu-Saad, Kathleen; Osman, Amira; Thrasher, James F; Kalter-Leibovici, Ofra

    2015-07-16

    Despite advanced smoking prevention and cessation policies in many countries, the prevalence of cigarette smoking among indigenous and some ethnic minorities continues to be high. This study examined the stages of change (SOC) of the readiness to quit smoking among Arab men in Israel shortly after new regulations of free-of-charge smoking cessation workshops and subsidized medications were introduced through primary health care clinics. We conducted a countrywide study in Israel between 2012-2013. Participants, 735 current smokers; 18-64 years old; were recruited from a stratified random sample and interviewed face-to-face using a structured questionnaire in Arabic. We used ordered regression to examine the contribution of socio-economic position (SEP), health status, psychosocial attributes, smoking-related factors, and physician advice to the SOC of the readiness to quit smoking (pre-contemplation, contemplation and preparation). Of the current smokers, 61.8% were at the pre-contemplation stage, 23.8% were at the contemplation stage, and only 14.4% were at the preparation stage. In the multinomial analysis, factors significantly (P stage compared to pre-contemplation stage included [odds ratio (OR), 95% confidence interval (CI)]: chronic morbidity [0.52, (0.31-0.88)], social support [1.35, (1.07-1.70)], duration of smoking for 11-21 years [1.94, (1.07-3.50)], three or more previous attempts to quit [2.27, (1.26-4.01)], knowledge about smoking hazards [1.75, (1.29-2.35)], positive attitudes toward smoking prevention [1.44, (1.14-1.82)], and physician advice to quit smoking [1.88, (1.19-2.97)]. The factors significantly (P stage compared to pre-contemplation stage were [OR, (95 % CI)]: chronic morbidity [0.36, (0.20-0.67)], anxiety [1.07, (1.01-1.13)], social support [1.34, (1.01-1.78)], duration of smoking 5 years or less [2.93, (1.14-7.52)], three or more previous attempts to quit [3.16, (1.60-6.26)], knowledge about smoking hazards [1.57, (1.10-2.21)], and

  4. The Accuracy of Pass/Fail Decisions in Random and Difficulty-Balanced Domain-Sampling Tests.

    Science.gov (United States)

    Schnipke, Deborah L.

    A common practice in some certification fields (e.g., information technology) is to draw items from an item pool randomly and apply a common passing score, regardless of the items administered. Because these tests are commonly used, it is important to determine how accurate the pass/fail decisions are for such tests and whether fairly small,…

  5. The Prevention of Depression and Anxiety in a Sample of High-Risk Adolescents: A Randomized Controlled Trial

    Science.gov (United States)

    Dobson, Keith S.; Hopkins, Jamie Ahnberg; Fata, Ladan; Scherrer, Martin; Allan, Lauren C.

    2010-01-01

    This study investigated the efficacy of cognitive behavioural therapy (CBT) techniques in preventing depression and anxiety in a group of adolescent high school students with elevated risk for developing emotional disorders. Students were screened using a measure of depression severity and clinical interview. Following screening procedures,…

  6. Early Endarterectomy Carries a Lower Procedural Risk Than Early Stenting in Patients With Symptomatic Stenosis of the Internal Carotid Artery: Results From 4 Randomized Controlled Trials.

    Science.gov (United States)

    Rantner, Barbara; Kollerits, Barbara; Roubin, Gary S; Ringleb, Peter A; Jansen, Olaf; Howard, George; Hendrikse, Jeroen; Halliday, Alison; Gregson, John; Eckstein, Hans-Henning; Calvet, David; Bulbulia, Richard; Bonati, Leo H; Becquemin, Jean-Pierre; Algra, Ale; Brown, Martin M; Mas, Jean-Louis; Brott, Thomas G; Fraedrich, Gustav

    2017-06-01

    Patients undergoing carotid endarterectomy (CEA) for symptomatic stenosis of the internal carotid artery benefit from early intervention. Heterogeneous data are available on the influence of timing of carotid artery stenting (CAS) on procedural risk. We investigated the association between timing of treatment (0-7 days and >7 days after the qualifying neurological event) and the 30-day risk of stroke or death after CAS or CEA in a pooled analysis of individual patient data from 4 randomized trials by the Carotid Stenosis Trialists' Collaboration. Analyses were done per protocol. To obtain combined estimates, logistic mixed models were applied. Among a total of 4138 patients, a minority received their allocated treatment within 7 days after symptom onset (14% CAS versus 11% CEA). Among patients treated within 1 week of symptoms, those treated by CAS had a higher risk of stroke or death compared with those treated with CEA: 8.3% versus 1.3%, risk ratio, 6.7; 95% confidence interval, 2.1 to 21.9 (adjusted for age at treatment, sex, and type of qualifying event). For interventions after 1 week, CAS was also more hazardous than CEA: 7.1% versus 3.6%, adjusted risk ratio, 2.0; 95% confidence interval, 1.5 to 2.7 (P value for interaction with time interval 0.06). In randomized trials comparing stenting with CEA for symptomatic carotid artery stenosis, CAS was associated with a substantially higher periprocedural risk during the first 7 days after the onset of symptoms. Early surgery is safer than stenting for preventing future stroke. URL: http://www.clinicaltrials.gov. Unique identifier: NCT00190398; URL: http://www.controlled-trials.com. Unique identifier: ISRCTN57874028; Unique identifier: ISRCTN25337470; URL: http://www.clinicaltrials.gov. Unique identifier: NCT00004732. © 2017 American Heart Association, Inc.

  7. Development a novel supramolecular solvent microextraction procedure for copper in environmental samples and its determination by microsampling flame atomic absorption spectrometry.

    Science.gov (United States)

    Yilmaz, Erkan; Soylak, Mustafa

    2014-08-01

    A supramolecular solvent (Ss) made up of reverse micelles of 1-decanol in tetrahydrofuran (THF): water was used for the fast and selective microextraction of Cu(II) prior to its determination by microsampling flame atomic absorption spectrometry (FAAS). Cu(II) was complexed with dimethyl dithiocarbamate (DMDC) to obtain hydrophobic complex and extracted to supramolecular solvent phase. The influences of some analytical parameters including pH, type and volume of supramolecular solvent, amount of complexing agent, ultrasonication and centrifuge time and sample volume were investigated. The effects of matrix components were also examined. The detection limit (LOD) and the quantification limit (LOQ) were 0.52µg L(-1) and 1.71µg L(-1) respectively. An preconcentration factor was obtained as 60 and the relative standard deviation was <3%. The accuracy of the developed method was evaluated by the analysis of the certified reference materials (TMDA-64.2 water, SRM 1568A Rice Flour and 8433 Corn Bran) and addition-recovery tests. The presented supramolecular solvent based liquid-liquid microextraction (SsLLME) procedure was applied to the determination of copper in food and water samples with satisfactory results. Copyright © 2014 Elsevier B.V. All rights reserved.

  8. Time-varying Markov regression random-effect model with Bayesian estimation procedures: Application to dynamics of functional recovery in patients with stroke.

    Science.gov (United States)

    Pan, Shin-Liang; Chen, Hsiu-Hsi

    2010-09-01

    The rates of functional recovery after stroke tend to decrease with time. Time-varying Markov processes (TVMP) may be more biologically plausible than time-invariant Markov process for modeling such data. However, analysis of such stochastic processes, particularly tackling reversible transitions and the incorporation of random effects into models, can be analytically intractable. We make use of ordinary differential equations to solve continuous-time TVMP with reversible transitions. The proportional hazard form was used to assess the effects of an individual's covariates on multi-state transitions with the incorporation of random effects that capture the residual variation after being explained by measured covariates under the concept of generalized linear model. We further built up Bayesian directed acyclic graphic model to obtain full joint posterior distribution. Markov chain Monte Carlo (MCMC) with Gibbs sampling was applied to estimate parameters based on posterior marginal distributions with multiple integrands. The proposed method was illustrated with empirical data from a study on the functional recovery after stroke. Copyright 2010 Elsevier Inc. All rights reserved.

  9. Comparing cluster-level dynamic treatment regimens using sequential, multiple assignment, randomized trials: Regression estimation and sample size considerations

    OpenAIRE

    NeCamp, Timothy; Kilbourne, Amy; Almirall, Daniel

    2016-01-01

    Cluster-level dynamic treatment regimens can be used to guide sequential, intervention or treatment decision-making at the cluster level in order to improve outcomes at the individual or patient-level. In a cluster-level DTR, the intervention or treatment is potentially adapted and re-adapted over time based on changes in the cluster that could be impacted by prior intervention, including based on aggregate measures of the individuals or patients that comprise it. Cluster-randomized sequentia...

  10. Additional Considerations in Determining Sample Size.

    Science.gov (United States)

    Levin, Joel R.; Subkoviak, Michael J.

    Levin's (1975) sample-size determination procedure for completely randomized analysis of variance designs is extended to designs in which antecedent or blocking variables information is considered. In particular, a researcher's choice of designs is framed in terms of determining the respective sample sizes necessary to detect specified contrasts…

  11. Approximating the variance of estimated means for systematic random sampling, illustrated with data of the French Soil Monitoring Network

    NARCIS (Netherlands)

    Brus, D.J.; Saby, N.P.A.

    2016-01-01

    In France like in many other countries, the soil is monitored at the locations of a regular, square grid thus forming a systematic sample (SY). This sampling design leads to good spatial coverage, enhancing the precision of design-based estimates of spatial means and totals. Design-based

  12. Endothelial nitric oxide synthase (G894T) gene polymorphism in a random sample of the Egyptian population: comparison with myocardial infarction patients.

    Science.gov (United States)

    Gad, Mohamed Z; Abdel Rahman, Mohamed F; Hashad, Ingy M; Abdel-Maksoud, Sahar M; Farag, Nabil M; Abou-Aisha, Khaled

    2012-07-01

    The aim of this study was to detect endothelial nitric oxide synthase (eNOS) Glu298Asp gene variants in a random sample of the Egyptian population, compare it with those from other populations, and attempt to correlate these variants with serum levels of nitric oxide (NO). The association of eNOS genotypes or serum NO levels with the incidence of acute myocardial infarction (AMI) was also examined. One hundred one unrelated healthy subjects and 104 unrelated AMI patients were recruited randomly from the 57357 Hospital and intensive care units of El Demerdash Hospital and National Heart Institute, Cairo, Egypt. eNOS genotypes were determined by polymerase chain reaction-restriction fragment length polymorphism. Serum NO was determined spectrophotometrically. The genotype distribution of eNOS Glu298Asp polymorphism determined for our sample was 58.42% GG (wild type), 33.66% GT, and 7.92% TT genotypes while allele frequencies were 75.25% and 24.75% for G and T alleles, respectively. No significant association between serum NO and specific eNOS genotype could be detected. No significant correlation between eNOS genotype distribution or allele frequencies and the incidence of AMI was observed. The present study demonstrated the predominance of the homozygous genotype GG over the heterozygous GT and homozygous TT in random samples of Egyptian population. It also showed the lack of association between eNOS genotypes and mean serum levels of NO, as well as the incidence of AMI.

  13. A solid phase extraction procedure for the determination of Cd(II) and Pb(II) ions in food and water samples by flame atomic absorption spectrometry.

    Science.gov (United States)

    Daşbaşı, Teslima; Saçmacı, Şerife; Ülgen, Ahmet; Kartal, Şenol

    2015-05-01

    A relatively rapid, accurate and precise solid phase extraction method is presented for the determination of cadmium(II) and lead(II) in various food and water samples. Quantitation is carried out by flame atomic absorption spectrometry (FAAS). The method is based on the retention of the trace metal ions on Dowex Marathon C, a strong acid cation exchange resin. Some important parameters affecting the analytical performance of the method such as pH, flow rate and volume of the sample solution; type, concentration, volume, flow rate of the eluent; and matrix effects on the retention of the metal ions were investigated. Common coexisting ions did not interfere on the separation and determination of the analytes. The detection limits (3 σb) for Cd(II) and Pb(II) were found as 0.13 and 0.18 μg L(-1), respectively, while the limit of quantification values (10 σb) were computed as 0.43 and 0.60 μg L(-1) for the same sequence of the analytes. The precision (as relative standard deviation was lower than 4% at 5 μg L(-1) Cd(II) and 10 μg L(-1) Pb(II) levels, and the preconcentration factor was found to be 250. The accuracy of the proposed procedure was verified by analysing the certified reference materials, SPS-WW2 Batch 108 wastewater level 2 and INCT-TL-1 tea leaves, with the satisfactory results. In addition, for the accuracy of the method the recovery studies (⩾ 95%) were carried out. The method was applied to the determination of the analytes in the various natural waters (lake water, tap water, waste water with boric acid, waste water with H2SO4) and food samples (pomegranate flower, organic pear, radish leaf, lamb meat, etc.), and good results were obtained. While the food samples almost do not contain cadmium, they have included lead at low levels of 0.13-1.12 μg g(-1). Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Differentiating emotions across contexts: comparing adults with and without social anxiety disorder using random, social interaction, and daily experience sampling.

    Science.gov (United States)

    Kashdan, Todd B; Farmer, Antonina S

    2014-06-01

    The ability to recognize and label emotional experiences has been associated with well-being and adaptive functioning. This skill is particularly important in social situations, as emotions provide information about the state of relationships and help guide interpersonal decisions, such as whether to disclose personal information. Given the interpersonal difficulties linked to social anxiety disorder (SAD), deficient negative emotion differentiation may contribute to impairment in this population. We hypothesized that people with SAD would exhibit less negative emotion differentiation in daily life, and these differences would translate to impairment in social functioning. We recruited 43 people diagnosed with generalized SAD and 43 healthy adults to describe the emotions they experienced over 14 days. Participants received palmtop computers for responding to random prompts and describing naturalistic social interactions; to complete end-of-day diary entries, they used a secure online website. We calculated intraclass correlation coefficients to capture the degree of differentiation of negative and positive emotions for each context (random moments, face-to-face social interactions, and end-of-day reflections). Compared to healthy controls, the SAD group exhibited less negative (but not positive) emotion differentiation during random prompts, social interactions, and (at trend level) end-of-day assessments. These differences could not be explained by emotion intensity or variability over the 14 days, or to comorbid depression or anxiety disorders. Our findings suggest that people with generalized SAD have deficits in clarifying specific negative emotions felt at a given point of time. These deficits may contribute to difficulties with effective emotion regulation and healthy social relationship functioning.

  15. Differentiating Emotions Across Contexts: Comparing Adults with and without Social Anxiety Disorder Using Random, Social Interaction, and Daily Experience Sampling

    Science.gov (United States)

    Kashdan, Todd B.; Farmer, Antonina S.

    2014-01-01

    The ability to recognize and label emotional experiences has been associated with well-being and adaptive functioning. This skill is particularly important in social situations, as emotions provide information about the state of relationships and help guide interpersonal decisions, such as whether to disclose personal information. Given the interpersonal difficulties linked to social anxiety disorder (SAD), deficient negative emotion differentiation may contribute to impairment in this population. We hypothesized that people with SAD would exhibit less negative emotion differentiation in daily life, and these differences would translate to impairment in social functioning. We recruited 43 people diagnosed with generalized SAD and 43 healthy adults to describe the emotions they experienced over 14 days. Participants received palmtop computers for responding to random prompts and describing naturalistic social interactions; to complete end-of-day diary entries, they used a secure online website. We calculated intraclass correlation coefficients to capture the degree of differentiation of negative and positive emotions for each context (random moments, face-to-face social interactions, and end-of-day reflections). Compared to healthy controls, the SAD group exhibited less negative (but not positive) emotion differentiation during random prompts, social interactions, and (at trend level) end-of-day assessments. These differences could not be explained by emotion intensity or variability over the 14 days, or to comorbid depression or anxiety disorders. Our findings suggest that people with generalized SAD have deficits in clarifying specific negative emotions felt at a given point of time. These deficits may contribute to difficulties with effective emotion regulation and healthy social relationship functioning. PMID:24512246

  16. Surveys of larval sealworm (Pseudoterranova decipiens infection in various fish species sampled from Nova Scotian waters between 1988 and 1996, with an assessment of examination procedures

    Directory of Open Access Journals (Sweden)

    G McClelland

    2001-11-01

    Full Text Available Between November 1988 and October 1996, >10,000 fish from the Breton Shelf, Sable Island Bank and the northeastern Gulf of Maine were examined for larval anisakines. Larval sealworm, Pseudoterranova decipiens, occurred in 30 of 39 species surveyed, including 8 new host records, Enchelyopus cimbrius, Lycodes reticulatus, Eumesogrammus praecisus, Lumpenus lumpretaeformis, Lumpenus maculatus, Cryptacanthodes maculatus, Artediellus atlanticus and Triglops murrayi. The parasite was most prevalent and abundant in mature demersal piscivores and benthic consumers. Sealworm densities (nr kg-1 host wt., however, were greatest in small benthophagous fish including mature E. cimbrius, A. atlanticus, T. murrayi and Aspidophoroides monopterygius, and juvenile Hippoglossoides platessoides. ANOVA revealed that geographical disparities in sealworm prevalence and abundance were highly significant in 14 of 20 species tested, although significant disparities between samples from each of the three areas were evident only in H. platessoides. Almost invariably, infection parameters were greatest in fish from Sable Island Bank. ANOVA also indicated that sealworm prevalence and/or abundance increased significantly in Sable Island Bank populations of Gadus morhua, H. platessoides, and seven other species between 1985-1986 and 1989-1990. Routine examinations, in which host flesh was sliced and candled, proved as efficacious as digestion in warm (35° C pepsin-HCl for detection of larval sealworm in the flesh of large frozen fish. Procedures employing fresh (iced samples, digestion at ambient temperature and microscopy are recommended, however, for surveys of small benthic consumers. Many of the sealworm infecting the latter hosts are tiny (2 to 10 mm in length nematodes, which escape detection by routine inspection, and may not survive in warm pepsin-HCl solution.

  17. Genetically predicted body mass index and Alzheimer's disease-related phenotypes in three large samples: Mendelian randomization analyses.

    Science.gov (United States)

    Mukherjee, Shubhabrata; Walter, Stefan; Kauwe, John S K; Saykin, Andrew J; Bennett, David A; Larson, Eric B; Crane, Paul K; Glymour, M Maria

    2015-12-01

    Observational research shows that higher body mass index (BMI) increases Alzheimer's disease (AD) risk, but it is unclear whether this association is causal. We applied genetic variants that predict BMI in Mendelian randomization analyses, an approach that is not biased by reverse causation or confounding, to evaluate whether higher BMI increases AD risk. We evaluated individual-level data from the AD Genetics Consortium (ADGC: 10,079 AD cases and 9613 controls), the Health and Retirement Study (HRS: 8403 participants with algorithm-predicted dementia status), and published associations from the Genetic and Environmental Risk for AD consortium (GERAD1: 3177 AD cases and 7277 controls). No evidence from individual single-nucleotide polymorphisms or polygenic scores indicated BMI increased AD risk. Mendelian randomization effect estimates per BMI point (95% confidence intervals) were as follows: ADGC, odds ratio (OR) = 0.95 (0.90-1.01); HRS, OR = 1.00 (0.75-1.32); GERAD1, OR = 0.96 (0.87-1.07). One subscore (cellular processes not otherwise specified) unexpectedly predicted lower AD risk. Copyright © 2015 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.

  18. Family constellation seminars improve psychological functioning in a general population sample: results of a randomized controlled trial.

    Science.gov (United States)

    Weinhold, Jan; Hunger, Christina; Bornhäuser, Annette; Link, Leoni; Rochon, Justine; Wild, Beate; Schweitzer, Jochen

    2013-10-01

    The study examined the efficacy of nonrecurring family constellation seminars on psychological health. We conducted a monocentric, single-blind, stratified, and balanced randomized controlled trial (RCT). After choosing their roles for participating in a family constellation seminar as either active participant (AP) or observing participant (OP), 208 adults (M = 48 years, SD = 10; 79% women) from the general population were randomly allocated to the intervention group (IG; 3-day family constellation seminar; 64 AP, 40 OP) or a wait-list control group (WLG; 64 AP, 40 OP). It was predicted that family constellation seminars would improve psychological functioning (Outcome Questionnaire OQ-45.2) at 2-week and 4-month follow-ups. In addition, we assessed the impact of family constellation seminars on psychological distress and motivational incongruence. The IG showed significantly improved psychological functioning (d = 0.45 at 2-week follow-up, p = .003; d = 0.46 at 4-month follow-up, p = .003). Results were confirmed for psychological distress and motivational incongruence. No adverse events were reported. This RCT provides evidence for the efficacy of family constellation in a nonclinical population. The implications of the findings are discussed.

  19. Effects of delayed compared with early umbilical cord clamping on maternal postpartum hemorrhage and cord blood gas sampling: a randomized trial.

    Science.gov (United States)

    Andersson, Ola; Hellström-Westas, Lena; Andersson, Dan; Clausen, Jesper; Domellöf, Magnus

    2013-05-01

    To investigate the effect of delayed cord clamping (DCC) compared with early cord clamping (ECC) on maternal postpartum hemorrhage (PPH) and umbilical cord blood gas sampling. Secondary analysis of a parallel-group, single-center, randomized controlled trial. Swedish county hospital. 382 term deliveries after a low-risk pregnancy. Deliveries were randomized to DCC (≥180 seconds, n = 193) or ECC (≤10 seconds, n = 189). Maternal blood loss was estimated by the midwife. Samples for blood gas analysis were taken from one umbilical artery and the umbilical vein, from the pulsating unclamped cord in the DCC group and from the double-clamped cord in the ECC group. Samples were classified as valid when the arterial-venous difference was -0.02 or less for pH and 0.5 kPa or more for pCO2 . Main outcome measures. PPH and proportion of valid blood gas samples. The differences between the DCC and ECC groups with regard to PPH (1.2%, p = 0.8) and severe PPH (-2.7%, p = 0.3) were small and non-significant. The proportion of valid blood gas samples was similar between the DCC (67%, n = 130) and ECC (74%, n = 139) groups, with 6% (95% confidence interval: -4%-16%, p = 0.2) fewer valid samples after DCC. Delayed cord clamping, compared with early, did not have a significant effect on maternal postpartum hemorrhage or on the proportion of valid blood gas samples. We conclude that delayed cord clamping is a feasible method from an obstetric perspective. © 2012 The Authors Acta Obstetricia et Gynecologica Scandinavica© 2012 Nordic Federation of Societies of Obstetrics and Gynecology.

  20. Variance results for the second and third reduced sample moments in neutron multiplicity counting for randomly triggered or signal-triggered counting gates

    Energy Technology Data Exchange (ETDEWEB)

    Burr, T. [Statistical Sciences Group, Los Alamos National Laboratory, Mail Stop F600, Los Alamos, NM 87545 (United States)], E-mail: tburr@lanl.gov; Butterfield, K. [Advanced Nuclear Technology Group, Los Alamos National Laboratory, Mail Stop F600, Los Alamos, NM 87545 (United States)

    2008-09-01

    Neutron multiplicity counting is an established method to estimate the spontaneous fission rate, and therefore also the plutonium mass for example, in a sample that includes other neutron sources. The extent to which the sample and detector obey the 'point model' assumptions impacts the estimate's total measurement error, but, in nearly all cases, for the random error contribution, it is useful to evaluate the variances of the second and third reduced sample moments of the neutron source strength. Therefore, this paper derives exact expressions for the variances and covariances of the second and third reduced sample moments for either randomly triggered or signal-triggered non-overlapping counting gates, and compares them to the corresponding variances in simulated data. Approximate expressions are also provided for the case of overlapping counting gates. These variances and covariances are useful in figure of merit calculations to predict assay performance prior to data collection. In addition, whenever real data are available, a bootstrap method is presented as an alternate but effective way to estimate these variances.

  1. Selection of the effect size for sample size determination for a continuous response in a superiority clinical trial using a hybrid classical and Bayesian procedure.

    Science.gov (United States)

    Ciarleglio, Maria M; Arendt, Christopher D; Peduzzi, Peter N

    2016-06-01

    When designing studies that have a continuous outcome as the primary endpoint, the hypothesized effect size ([Formula: see text]), that is, the hypothesized difference in means ([Formula: see text]) relative to the assumed variability of the endpoint ([Formula: see text]), plays an important role in sample size and power calculations. Point estimates for [Formula: see text] and [Formula: see text] are often calculated using historical data. However, the uncertainty in these estimates is rarely addressed. This article presents a hybrid classical and Bayesian procedure that formally integrates prior information on the distributions of [Formula: see text] and [Formula: see text] into the study's power calculation. Conditional expected power, which averages the traditional power curve using the prior distributions of [Formula: see text] and [Formula: see text] as the averaging weight, is used, and the value of [Formula: see text] is found that equates the prespecified frequentist power ([Formula: see text]) and the conditional expected power of the trial. This hypothesized effect size is then used in traditional sample size calculations when determining sample size for the study. The value of [Formula: see text] found using this method may be expressed as a function of the prior means of [Formula: see text] and [Formula: see text], [Formula: see text], and their prior standard deviations, [Formula: see text]. We show that the "naïve" estimate of the effect size, that is, the ratio of prior means, should be down-weighted to account for the variability in the parameters. An example is presented for designing a placebo-controlled clinical trial testing the antidepressant effect of alprazolam as monotherapy for major depression. Through this method, we are able to formally integrate prior information on the uncertainty and variability of both the treatment effect and the common standard deviation into the design of the study while maintaining a frequentist framework for

  2. A randomized controlled trial to compare fentanyl-propofol and ketamine-propofol combination for procedural sedation and analgesia in laparoscopic tubal ligation

    Directory of Open Access Journals (Sweden)

    Ranju Singh

    2013-01-01

    Full Text Available Background: Procedural sedation and analgesia is widely being used for female laparoscopic sterilization using combinations of different drugs at varying doses. This study compared the combination of fentanyl and propofol, and ketamine and propofol in patients undergoing outpatient laparoscopic tubal ligation, with respect to their hemodynamic effects, postoperative recovery characteristics, duration of hospital stay, adverse effects, and patient comfort and acceptability. Settings and Design: Randomized, double blind. Methods: Patients were assigned to receive premixed injection of either fentanyl 1.5 μg/kg + propofol 2 mg/kg (Group PF, n0=50 or ketamine 0.5 mg/kg + propofol 2 mg/kg (Group PK, n=50. Hemodynamic data, peripheral oxygen saturation, and respiratory rate were recorded perioperatively. Recovery time, time to discharge, and comfort score were noted. Statistical Analysis: Chi-square (χ2 test was used for categorical data. Student′s t-test was used for quantitative variables for comparison between the two groups. For intragroup comparison, paired t-test was used. SPSS 14.0 was used for analysis. Results: Although the heart rate was comparable, blood pressures were consistently higher in group PK. Postoperative nausea and vomiting and delay in voiding were more frequent in group PK ( P<0.05. The time to reach Aldrete score ≥8 was significantly longer in group PK (11.14±3.29 min in group PF vs. 17.3±6.32 min in group PK, P<0.01. The time to discharge was significantly longer in group PK (105.8±13.07 min in group PF vs.138.18±13.20 min in group PK, P<0.01. Patient comfort and acceptability was better in group PF, P<0.01. Conclusion: As compared to ketamine-propofol, fentanyl-propofol combination is associated with faster recovery, earlier discharge, and better patient acceptability.

  3. A double-blind randomized controlled trial to study the efficacy of topiramate in a civilian sample of PTSD.

    Science.gov (United States)

    Yeh, Mary S L; Mari, Jair Jesus; Costa, Mariana Caddrobi Pupo; Andreoli, Sergio Baxter; Bressan, Rodrigo Affonseca; Mello, Marcelo Feijó

    2011-10-01

    To evaluate the efficacy and tolerability of topiramate in patients with posttraumatic stress disorder (PTSD). We conducted a 12-week double-blind, randomized, placebo-controlled study comparing topiramate to placebo. Men and women aged 18-62 years with diagnosis of PTSD according to DSM-IV were recruited from the outpatient clinic of the violence program of Federal University of São Paulo Hospital (Prove-UNIFESP), São Paulo City, between April 2006 and December 2009. Subjects were assessed for the Clinician-Administered Posttraumatic Stress Scale (CAPS), Clinical Global Impression, and Beck Depression Inventory (BDI). After 1-week period of washout, 35 patients were randomized to either group. The primary outcome measure was the CAPS total score changes from baseline to the endpoint. 82.35% of patients in the topiramate group exhibited improvements in PTSD symptoms. The efficacy analysis demonstrated that patients in the topiramate group exhibited significant improvements in reexperiencing symptoms: flashbacks, intrusive memories, and nightmares of the trauma (CAPS-B; P= 0.04) and in avoidance/numbing symptoms associated with the trauma, social isolation, and emotional numbing (CAPS-C; P= 0.0001). Furthermore, the experimental group demonstrated a significant difference in decrease in CAPS total score (topiramate -57.78; placebo -32.41; P= 0.0076). Mean topiramate dose was 102.94 mg/d. Topiramate was generally well tolerated. Topiramate was effective in improving reexperiencing and avoidance/numbing symptom clusters in patients with PTSD. This study supports the use of anticonvulsants for the improvement of symptoms of PTSD. © 2010 Blackwell Publishing Ltd.

  4. 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.

  5. Purposive versus random sampling for map validation: a case study on ecotope maps of floodplains in the Netherlands

    NARCIS (Netherlands)

    Knotters, M.; Brus, D.J.

    2013-01-01

    The quality of ecotope maps of five districts of main water courses in the Netherlands was assessed on the basis of independent validation samples of field observations. The overall proportion of area correctly classified, and user's and producer's accuracy for each map unit were estimated. In four

  6. Estimation of the Box Correction for Degrees of Freedom from Sample Data in Randomized Block and Split-Plot Designs

    Science.gov (United States)

    Huynh, Huynh; Feldt, Leonard S.

    1976-01-01

    When the variance assumptions of a repeated measures ANOVA are not met, the F distribution of the mean square ratio should be adjusted by the sample estimate of the Box correction factor. An alternative is proposed which is shown by Monte Carlo methods to be less biased for a moderately large factor. (RC)

  7. Randomized controlled trial of endoscopic ultrasound-guided fine-needle sampling with or without suction for better cytological diagnosis

    DEFF Research Database (Denmark)

    Puri, Rajesh; Vilmann, Peter; Saftoiu, Adrian

    2009-01-01

    ). The samples were characterized for cellularity and bloodiness, with a final cytology diagnosis established blindly. The final diagnosis was reached either by EUS-FNA if malignancy was definite, or by surgery and/or clinical follow-up of a minimum of 6 months in the cases of non-specific benign lesions...

  8. HPV self-sampling or the Pap-smear: a randomized study among cervical screening nonattenders from lower socioeconomic groups in France.

    Science.gov (United States)

    Sancho-Garnier, H; Tamalet, C; Halfon, P; Leandri, F X; Le Retraite, L; Djoufelkit, K; Heid, P; Davies, P; Piana, L

    2013-12-01

    Today in France, low attendance to cervical screening by Papanicolaou cytology (Pap-smear) is a major contributor to the 3,000 new cervical cancer cases and 1,000 deaths that occur from this disease every year. Nonattenders are mostly from lower socioeconomic groups and testing of self-obtained samples for high-risk Human Papilloma virus (HPV) types has been proposed as a method to increase screening participation in these groups. In 2011, we conducted a randomized study of women aged 35-69 from very low-income populations around Marseille who had not responded to an initial invitation for a free Pap-smear. After randomization, one group received a second invitation for a free Pap-smear and the other group was offered a free self-sampling kit for HPV testing. Participation rates were significantly different between the two groups with only 2.0% of women attending for a Pap-smear while 18.3% of women returned a self-sample for HPV testing (p ≤ 0.001). The detection rate of high-grade lesions (≥CIN2) was 0.2‰ in the Pap-smear group and 1.25‰ in the self-sampling group (p = 0.01). Offering self-sampling increased participation rates while the use of HPV testing increased the detection of cervical lesions (≥CIN2) in comparison to the group of women receiving a second invitation for a Pap-smear. However, low compliance to follow-up in the self-sampling group reduces the effectiveness of this screening approach in nonattenders women and must be carefully managed. Copyright © 2013 UICC.

  9. Aerobic physical activity and resistance training: an application of the theory of planned behavior among adults with type 2 diabetes in a random, national sample of Canadians

    Directory of Open Access Journals (Sweden)

    Karunamuni Nandini

    2008-12-01

    Full Text Available Abstract Background Aerobic physical activity (PA and resistance training are paramount in the treatment and management of type 2 diabetes (T2D, but few studies have examined the determinants of both types of exercise in the same sample. Objective The primary purpose was to investigate the utility of the Theory of Planned Behavior (TPB in explaining aerobic PA and resistance training in a population sample of T2D adults. Methods A total of 244 individuals were recruited through a random national sample which was created by generating a random list of household phone numbers. The list was proportionate to the actual number of household telephone numbers for each Canadian province (with the exception of Quebec. These individuals completed self-report TPB constructs of attitude, subjective norm, perceived behavioral control and intention, and a 3-month follow-up that assessed aerobic PA and resistance training. Results TPB explained 10% and 8% of the variance respectively for aerobic PA and resistance training; and accounted for 39% and 45% of the variance respectively for aerobic PA and resistance training intentions. Conclusion These results may guide the development of appropriate PA interventions for aerobic PA and resistance training based on the TPB.

  10. Correspondence of two procedures to measure abdominal circumference in a convenience sample of urban, middle-class schoolchildren in Guatemala City.

    Science.gov (United States)

    Alvarado, Virginia J; Mayorga, Evelyn; Molina, Susana; Solomons, Noel W

    2010-01-01

    Given an emerging concern for juvenile overweight and obesity, even in populations of developing countries, techniques to assess central obesity, such as abdominal circumference (AC), are of increasing interest. To compare two procedures for measuring AC in schoolchildren from a convenience sample of middle-class, urban children aged 72 to 131 months in Guatemala City. We conducted a cross-sectional study (August 2004- April 2005) in 363 schoolchildren; 190 boys and 173 girls. The AC was recorded using both the conventional natural waist circumference (NWC) and the umbilical-level abdominal circumference (UAC) methods; each of which was measured over a thin T-shirt. Height and weight were also measured. The NWC and UAC methods were compared between genders and age groups. In addition, correlation coefficients and Bland-Altman regression were performed. A reproducibility study was performed on a subsample of 50 children. Mean NWC was 63.2+/-10.0 cm for boys and 60.2+/-7.7 cm for girls (p=0.001), and mean UAC was 65.9+/-11.0 cm for boys and 63.2+/-8.8 cm for girls (p=0.008). Both measures of AC generally increased with age. The UAC - NWC difference increased with abdominal girth. The Pearson correlation coefficient of BMI vs. NWC and BMI vs. UAC was r=0.92, CV=0.46+/-0.27%. A high test-retest reproducibility (r > 0.98, CV= 0.50+/-0.24%) of the NWC and UAC measurements was found. Reliable NWC and UAC measurements may be obtained by applying a correction term to account for light clothing. Both measurements are applicable methodologies for the collection of data in populations with cultural limitations.

  11. A cluster-randomized trial of a middle school gender violence prevention program: Design, rationale, and sample characteristics.

    Science.gov (United States)

    Abebe, Kaleab Z; Jones, Kelley A; Ciaravino, Samantha; Ripper, Lisa; Paglisotti, Taylor; Morrow, Sarah Elizabeth; Grafals, Melanie; Van Dusen, Courtney; Miller, Elizabeth

    2017-11-01

    High rates of adolescent relationship abuse (ARA) and sexual violence (SV) reported among adolescents point to the need for prevention among middle school-age youth. This is a cluster randomized controlled trial to test an athletic coach-delivered ARA/SV prevention program in 41 middle schools (38 clusters). Trained coaches talk to their male athletes about 1) what constitutes harmful vs. respectful relationship behaviors, 2) dispelling myths that glorify male sexual aggression and promoting more gender-equitable attitudes, and 3) positive bystander intervention when aggressive male behaviors toward females are witnessed. A total of 973 male athletes (ages 11-14, grades 6-8) are participating. Athletes complete surveys at the beginning and end of sports season (Time 2), and one year later (Time 3). The primary outcome is an increase in positive bystander behaviors (i.e., intervening in peers' disrespectful or harmful behaviors); secondary outcomes are changes in recognition of what constitutes abusive behavior, intentions to intervene, and gender equitable attitudes (Time 2 and 3) as well as reduction in abuse perpetration (Time 3). Participating schools have a greater proportion of non-White students and students on free/reduced lunch compared to schools that declined participation. Participants' self-reported ethnicities are 54.5% White, 29.0% Black, 1.4% Hispanic and the remainder, multi-racial, other, or not reported. This study will evaluate the effectiveness of a coach-delivered ARA/SV prevention program for middle school male athletes. Findings will add to the evidence base regarding developmentally appropriate violence prevention programs as well as the role of coaches in adolescent health promotion. Clinical Trials #: NCT02331238. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  12. Reducing eating disorder onset in a very high risk sample with significant comorbid depression: A randomized controlled trial.

    Science.gov (United States)

    Taylor, C Barr; Kass, Andrea E; Trockel, Mickey; Cunning, Darby; Weisman, Hannah; Bailey, Jakki; Sinton, Meghan; Aspen, Vandana; Schecthman, Kenneth; Jacobi, Corinna; Wilfley, Denise E

    2016-05-01

    Eating disorders (EDs) are serious problems among college-age women and may be preventable. An indicated online eating disorder (ED) intervention, designed to reduce ED and comorbid pathology, was evaluated. 206 women (M age = 20 ± 1.8 years; 51% White/Caucasian, 11% African American, 10% Hispanic, 21% Asian/Asian American, 7% other) at very high risk for ED onset (i.e., with high weight/shape concerns plus a history of being teased, current or lifetime depression, and/or nonclinical levels of compensatory behaviors) were randomized to a 10-week, Internet-based, cognitive-behavioral intervention or waitlist control. Assessments included the Eating Disorder Examination (EDE, to assess ED onset), EDE-Questionnaire, Structured Clinical Interview for DSM Disorders, and Beck Depression Inventory-II. ED attitudes and behaviors improved more in the intervention than control group (p = .02, d = 0.31); although ED onset rate was 27% lower, this difference was not significant (p = .28, NNT = 15). In the subgroup with highest shape concerns, ED onset rate was significantly lower in the intervention than control group (20% vs. 42%, p = .025, NNT = 5). For the 27 individuals with depression at baseline, depressive symptomatology improved more in the intervention than control group (p = .016, d = 0.96); although ED onset rate was lower in the intervention than control group, this difference was not significant (25% vs. 57%, NNT = 4). An inexpensive, easily disseminated intervention might reduce ED onset among those at highest risk. Low adoption rates need to be addressed in future research. (c) 2016 APA, all rights reserved).

  13. Laqueadura intraparto e de intervalo Intrapartum and interval tubal sterilization: characteristics correlated with the procedure and regret in a sample of women from a public hospital

    Directory of Open Access Journals (Sweden)

    Arlete Maria dos Santos Fernandes

    2006-10-01

    foi cesárea. Não se detectou diferença nas taxas de satisfação e arrependimento após o procedimento entre os grupos.BACKGROUND: Brazil is a country with a high prevalence of tubal ligation, which is frequently performed at the time of delivery. In recent years, an increase in tubal reversal has been noticed, primarily among young women. OBJECTIVES: To study characteristics correlated with the procedure, determine frequency of intrapartum tubal ligation, measure patient satisfaction rates and tubal sterilization regret, in a sample of post-tubal patients. METHODS: Three hundred and thirty-five women underwent tubal ligation. The variables studied were related to the procedure: age at tubal ligation, whether ligation was performed intrapartum (vaginal or cesarean section or after an interval (other than the intrapartum and puerperal period, health service performing the sterilization, medical expenses paid for the procedure, reason stated for choosing the method and causes related to satisfaction/regret: desire to become pregnant after sterilization, search for treatment and performance of tubal ligation reversal. The women were divided into two groups, a group undergoing ligation in the intrapartum period and a second group ligated after an interval, to evaluate the association between variables by using Fisher's exact test and chi-squared calculation with Yates' correction. The study was approved by the Ethics Committee of the institution. RESULTS: There was a predominance of Caucasian women over 35 years of age, married, and with a low level of education of which 43.5% had undergone sterilization before 30 years of age. Two hundred and forty-five women underwent intrapartum tubal ligation, 91.2% of them had cesarean delivery and 44.6% vaginal delivery. In both groups undergoing intrapartum tubal ligation and ligation after an interval, 82.0% and 80.8% reported satisfaction with the method. Although 14.6% expressed a desire to become pregnant at some time after

  14. Novel approach to systematic random sampling in population surveys: Lessons from the United Arab Emirates National Diabetes Study (UAEDIAB).

    Science.gov (United States)

    Sulaiman, Nabil; Albadawi, Salah; Abusnana, Salah; Fikri, Mahmoud; Madani, Abdulrazzag; Mairghani, Maisoon; Alawadi, Fatheya; Zimmet, Paul; Shaw, Jonathan

    2015-09-01

    The prevalence of diabetes has risen rapidly in the Middle East, particularly in the Gulf Region. However, some prevalence estimates have not fully accounted for large migrant worker populations and have focused on minority indigenous populations. The objectives of the UAE National Diabetes and Lifestyle Study are to: (i) define the prevalence of, and risk factors for, T2DM; (ii) describe the distribution and determinants of T2DM risk factors; (iii) study health knowledge, attitudes, and (iv) identify gene-environment interactions; and (v) develop baseline data for evaluation of future intervention programs. Given the high burden of diabetes in the region and the absence of accurate data on non-UAE nationals in the UAE, a representative sample of the non-UAE nationals was essential. We used an innovative methodology in which non-UAE nationals were sampled when attending the mandatory biannual health check that is required for visa renewal. Such an approach could also be used in other countries in the region. Complete data were available for 2719 eligible non-UAE nationals (25.9% Arabs, 70.7% Asian non-Arabs, 1.1% African non-Arabs, and 2.3% Westerners). Most were men service and sales, and unskilled occupations. Most (37.4%) had completed high school and 4.1% had a postgraduate degree. This novel methodology could provide insights for epidemiological studies in the UAE and other Gulf States, particularly for expatriates. © 2015 Ruijin Hospital, Shanghai Jiaotong University School of Medicine and Wiley Publishing Asia Pty Ltd.

  15. Two to five repeated measurements per patient reduced the required sample size considerably in a randomized clinical trial for patients with inflammatory rheumatic diseases

    Directory of Open Access Journals (Sweden)

    Smedslund Geir

    2013-02-01

    Full Text Available Abstract Background Patient reported outcomes are accepted as important outcome measures in rheumatology. The fluctuating symptoms in patients with rheumatic diseases have serious implications for sample size in clinical trials. We estimated the effects of measuring the outcome 1-5 times on the sample size required in a two-armed trial. Findings In a randomized controlled trial that evaluated the effects of a mindfulness-based group intervention for patients with inflammatory arthritis (n=71, the outcome variables Numerical Rating Scales (NRS (pain, fatigue, disease activity, self-care ability, and emotional wellbeing and General Health Questionnaire (GHQ-20 were measured five times before and after the intervention. For each variable we calculated the necessary sample sizes for obtaining 80% power (α=.05 for one up to five measurements. Two, three, and four measures reduced the required sample sizes by 15%, 21%, and 24%, respectively. With three (and five measures, the required sample size per group was reduced from 56 to 39 (32 for the GHQ-20, from 71 to 60 (55 for pain, 96 to 71 (73 for fatigue, 57 to 51 (48 for disease activity, 59 to 44 (45 for self-care, and 47 to 37 (33 for emotional wellbeing. Conclusions Measuring the outcomes five times rather than once reduced the necessary sample size by an average of 27%. When planning a study, researchers should carefully compare the advantages and disadvantages of increasing sample size versus employing three to five repeated measurements in order to obtain the required statistical power.

  16. Sample Preparation of Nano-sized Inorganic Materials for Scanning Electron Microscopy or Transmission Electron Microscopy: Scientific Operating Procedure SOP-P-2

    Science.gov (United States)

    2015-07-01

    sample. Nano- sized particles have a tendency to agglomerate during sample preparation. ERDC/GSL SR-15-1 4 3 Scope This SOP is used to determine the...conductive vs. nonconductive samples. The preparation of nanomaterial samples for imaging can be challenging as these materials tend to agglomerate or...aggregated or agglomerated samples. Another way is to extract the material from the liquid. In selected cases, imaging of the nanoparticles is aided

  17. Solid-phase extraction and separation procedure for trace aluminum in water samples and its determination by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS).

    Science.gov (United States)

    Ciftci, Harun; Er, Cigdem

    2013-03-01

    In the present study, a separation/preconcentration procedure for determination of aluminum in water samples has been developed by using a new atomic absorption spectrometer concept with a high-intensity xenon short-arc lamp as continuum radiation source, a high-resolution double-echelle monochromator, and a charge-coupled device array detector. Sample solution pH, sample volume, flow rate of sample solution, volume, and concentration of eluent for solid-phase extraction of Al chelates with 4-[(dicyanomethyl)diazenyl] benzoic acid on polymeric resin (Duolite XAD-761) have been investigated. The adsorbed aluminum on resin was eluted with 5 mL of 2 mol L(-1) HNO(3) and its concentration was determined by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS). Under the optimal conditions, limit of detection obtained with HR-CS FAAS and Line Source FAAS (LS-FAAS) were 0.49 μg L(-1) and 3.91 μg L(-1), respectively. The accuracy of the procedure was confirmed by analyzing certified materials (NIST SRM 1643e, Trace elements in water) and spiked real samples. The developed procedure was successfully applied to water samples.

  18. Improved diagnosis of Trichuris trichiura by using a bead-beating procedure on ethanol preserved stool samples prior to DNA isolation and the performance of multiplex real-time PCR for intestinal parasites.

    Science.gov (United States)

    Kaisar, Maria M M; Brienen, Eric A T; Djuardi, Yenny; Sartono, Erliyani; Yazdanbakhsh, Maria; Verweij, Jaco J; Supali, Taniawati; VAN Lieshout, Lisette

    2017-06-01

    For the majority of intestinal parasites, real-time PCR-based diagnosis outperforms microscopy. However, the data for Trichuris trichiura have been less convincing and most comparative studies have been performed in populations with low prevalence. This study aims to improve detection of T. trichuria DNA in human stool by evaluating four sample preparation methods. Faecal samples (n = 60) were collected at Flores island, Indonesia and examined by microscopy. Aliquots were taken and a bead-beating procedure was used both on directly frozen stool and on material preserved with 96% ethanol. PCR on frozen samples showed 40% to be positive for T. trichiura, compared with 45% positive by microscopy. The percentage positive increased when using ethanol preservation (45·0%), bead-beating (51·7%) and a combination (55·0%) and all three methods showed significantly higher DNA loads. The various procedures had a less pronounced effect on the PCR results of nine other parasite targets tested. Most prevalent were Ascaris lumbricoides (≈60%), Necator americanus (≈60%), Dientamoeba fragilis (≈50%) and Giardia lamblia (≈12%). To validate the practicality of the procedure, bead-beating was applied in a population-based survey testing 910 stool samples. Findings confirmed bead-beating before DNA extraction to be a highly efficient procedure for the detection of T. trichiura DNA in stool.

  19. Seminal plasma insemination during ovum-pickup—a method to increase pregnancy rate in IVF/ICSI procedure. A pilot randomized trial

    National Research Council Canada - National Science Library

    Chicea, Radu; Ispasoiu, Florin; Focsa, Mircea

    2013-01-01

    In IVF procedures, endometrial function is a limiting factor of the pregnancy rate and the aims of this study is to determine whether seminal plasma insemination at ovum pick-up in IVF has any effect on pregnancy...

  20. A Split Mouth Randomized Clinical Comparative Study to Evaluate the Efficacy of Gingival Depigmentation Procedure Using Conventional Scalpel Technique or Diode Laser

    OpenAIRE

    Suragimath, Girish; Lohana, Mohini Hemant; Varma, Siddhartha

    2016-01-01

    Introduction: Dark or black coloured gingiva is an esthetic concern especially in subjects with high lip line or gummy smile. Gingival depigmentation procedure is a type of perioplastic surgery where the gingival epithelium is excised with various techniques to lighten the colour of the gingiva. The aim of this study was to compare the clinical efficacy of gingival depigmentation procedure with conventional scalpel technique and diode laser application.

  1. Validity of protein-osmolality versus protein-creatinine ratios in the estimation of quantitative proteinuria from random samples of urine in children.

    Science.gov (United States)

    Morgenstern, Bruce Z; Butani, Lavjay; Wollan, Peter; Wilson, David M; Larson, Timothy S

    2003-04-01

    Proteinuria is an important marker of kidney disease. Simple methods to determine the presence of proteinuria in a semiquantitative fashion require measurement of either a protein-creatinine or protein-osmolality ratio. Urine samples from 134 healthy infants and children and 150 children from the pediatric nephrology practice were analyzed to develop normative data for protein-osmolality ratios on random urine samples and compare protein-osmolality with protein-creatinine ratio as a predictor of 24-hour urine protein excretion. Children were grouped according to age. Three groups were established: infants (protein excretion was determined to be a protein-osmolality ratio of 0.15 mg x kg H2O/mOsm. L; for children between 2 and 8 years old, 0.14; and for children older than 8 years, 0.17 (P = not significant between age groups). The corresponding optimal cutoff value for protein-creatinine ratio for the entire group of children older than 2 years is 0.20. Area under the curve analysis of receiver operator characteristic curves showed protein-creatinine ratio was superior to protein-osmolality ratio for predicting abnormal amounts of proteinuria in children and adolescents (P protein-creatinine ratio in children, it would be appropriate to screen urine samples for proteinuria using protein-creatinine ratio rather than protein-osmolality ratio.

  2. Changes in brain volume and cognition in a randomized trial of exercise and social interaction in a community-based sample of non-demented Chinese elders.

    Science.gov (United States)

    Mortimer, James A; Ding, Ding; Borenstein, Amy R; DeCarli, Charles; Guo, Qihao; Wu, Yougui; Zhao, Qianhua; Chu, Shugang

    2012-01-01

    Physical exercise has been shown to increase brain volume and improve cognition in randomized trials of non-demented elderly. Although greater social engagement was found to reduce dementia risk in observational studies, randomized trials of social interventions have not been reported. A representative sample of 120 elderly from Shanghai, China was randomized to four groups (Tai Chi, Walking, Social Interaction, No Intervention) for 40 weeks. Two MRIs were obtained, one before the intervention period, the other after. A neuropsychological battery was administered at baseline, 20 weeks, and 40 weeks. Comparison of changes in brain volumes in intervention groups with the No Intervention group were assessed by t-tests. Time-intervention group interactions for neuropsychological measures were evaluated with repeated-measures mixed models. Compared to the No Intervention group, significant increases in brain volume were seen in the Tai Chi and Social Intervention groups (p < 0.05). Improvements also were observed in several neuropsychological measures in the Tai Chi group, including the Mattis Dementia Rating Scale score (p = 0.004), the Trailmaking Test A (p = 0.002) and B (p = 0.0002), the Auditory Verbal Learning Test (p = 0.009), and verbal fluency for animals (p = 0.01). The Social Interaction group showed improvement on some, but fewer neuropsychological indices. No differences were observed between the Walking and No Intervention groups. The findings differ from previous clinical trials in showing increases in brain volume and improvements in cognition with a largely non-aerobic exercise (Tai Chi). In addition, intellectual stimulation through social interaction was associated with increases in brain volume as well as with some cognitive improvements.

  3. Why choose Random Forest to predict rare species distribution with few samples in large undersampled areas? Three Asian crane species models provide supporting evidence

    Directory of Open Access Journals (Sweden)

    Chunrong Mi

    2017-01-01

    Full Text Available Species distribution models (SDMs have become an essential tool in ecology, biogeography, evolution and, more recently, in conservation biology. How to generalize species distributions in large undersampled areas, especially with few samples, is a fundamental issue of SDMs. In order to explore this issue, we used the best available presence records for the Hooded Crane (Grus monacha, n = 33, White-naped Crane (Grus vipio, n = 40, and Black-necked Crane (Grus nigricollis, n = 75 in China as three case studies, employing four powerful and commonly used machine learning algorithms to map the breeding distributions of the three species: TreeNet (Stochastic Gradient Boosting, Boosted Regression Tree Model, Random Forest, CART (Classification and Regression Tree and Maxent (Maximum Entropy Models. In addition, we developed an ensemble forecast by averaging predicted probability of the above four models results. Commonly used model performance metrics (Area under ROC (AUC and true skill statistic (TSS were employed to evaluate model accuracy. The latest satellite tracking data and compiled literature data were used as two independent testing datasets to confront model predictions. We found Random Forest demonstrated the best performance for the most assessment method, provided a better model fit to the testing data, and achieved better species range maps for each crane species in undersampled areas. Random Forest has been generally available for more than 20 years and has been known to perform extremely well in ecological predictions. However, while increasingly on the rise, its potential is still widely underused in conservation, (spatial ecological applications and for inference. Our results show that it informs ecological and biogeographical theories as well as being suitable for conservation applications, specifically when the study area is undersampled. This method helps to save model-selection time and effort, and allows robust and rapid

  4. Microscale Procedure for Inorganic Qualitative Analysis with Emphasis on Writing Equations: Chemical Fingerprinting Applied to the "n"-bottle Problem of Matching Samples with Their Formulas

    Science.gov (United States)

    Sattsangi, Prem D.

    2014-01-01

    A laboratory method for teaching inorganic qualitative analysis and chemical equations is described. The experiment has been designed to focus attention on cations and anions that react to form products. This leads to a logical approach to understand and write chemical equations. The procedure uses 3 mL plastic micropipettes to store and deliver…

  5. In vivo photoacoustic mouse eye imaging of healing after chemical injury and automated eyeball surface estimation based on a random sample consensus algorithm

    Science.gov (United States)

    Jeon, Seungwan; Song, Hyun Beom; Kim, Jaewoo; Lee, Byung Joo; Kim, Jeong Hun; Kim, Chulhong

    2017-03-01

    Ocular chemical damage may induce limbal vessel ischemia and neovascularization, but the pathophysiology of the disease is not completely known. To observe changes in blood vessels after alkaline burn, we monitored the anterior segment and choroidal vasculature using a photoacoustic microscope (OR-PAM). We were able to observe not only the iris blood vessels but also the choroidal vessels under the sclera, which were difficult to be observed with conventional photographs. After alkali burning, we observed neovascularization and limbal ischemia and successfully tracked changes in vasculature during the 7-day healing process. We also used the RANdom SAmple Consensus (RANSAC) method to segment the abnormally generated blood vessels in the cornea by detecting the eyeball surface and successfully visualize the distance from each PA signal to the center of the eye. We believe that photoacoustic imaging has an important potential to reveal the pathophysiology of limb ischemia and neovascularization.

  6. Access to medical care among persons with musculoskeletal conditions. A study using a random sample of households in San Mateo County, California.

    Science.gov (United States)

    Yelin, E; Bernhard, G; Pflugrad, D

    1995-08-01

    To study access to medical care services, including subspecialty care, among persons with musculoskeletal conditions. In early 1993, a random sample of households in San Mateo County, California, was screened for the presence of household members with musculoskeletal conditions, and a member of each household so identified was administered a structured survey about access to medical care and other related subjects. Eighty-six percent of all persons with a musculoskeletal condition had ever seen at least one physician for the condition, but only 6.5% had ever seen a rheumatologist. Those without health insurance were only 82% as likely as those with health insurance to have ever seen a physician. Most persons with a musculoskeletal condition have seen a physician for the condition, but lack of health insurance significantly reduces the proportion who have done so.

  7. Random Sampling of Squamate Reptiles in Spanish Natural Reserves Reveals the Presence of Novel Adenoviruses in Lacertids (Family Lacertidae) and Worm Lizards (Amphisbaenia).

    Science.gov (United States)

    Szirovicza, Leonóra; López, Pilar; Kopena, Renáta; Benkő, Mária; Martín, José; Pénzes, Judit J

    2016-01-01

    Here, we report the results of a large-scale PCR survey on the prevalence and diversity of adenoviruses (AdVs) in samples collected randomly from free-living reptiles. On the territories of the Guadarrama Mountains National Park in Central Spain and of the Chafarinas Islands in North Africa, cloacal swabs were taken from 318 specimens of eight native species representing five squamate reptilian families. The healthy-looking animals had been captured temporarily for physiological and ethological examinations, after which they were released. We found 22 AdV-positive samples in representatives of three species, all from Central Spain. Sequence analysis of the PCR products revealed the existence of three hitherto unknown AdVs in 11 Carpetane rock lizards (Iberolacerta cyreni), nine Iberian worm lizards (Blanus cinereus), and two Iberian green lizards (Lacerta schreiberi), respectively. Phylogeny inference showed every novel putative virus to be a member of the genus Atadenovirus. This is the very first description of the occurrence of AdVs in amphisbaenian and lacertid hosts. Unlike all squamate atadenoviruses examined previously, two of the novel putative AdVs had A+T rich DNA, a feature generally deemed to mirror previous host switch events. Our results shed new light on the diversity and evolution of atadenoviruses.

  8. Impact of an educational intervention on women's knowledge and acceptability of human papillomavirus self-sampling: a randomized controlled trial in Cameroon.

    Science.gov (United States)

    Sossauer, Gaëtan; Zbinden, Michel; Tebeu, Pierre-Marie; Fosso, Gisèle K; Untiet, Sarah; Vassilakos, Pierre; Petignat, Patrick

    2014-01-01

    Human papillomavirus (HPV) self-sampling (Self-HPV) may be used as a primary cervical cancer screening method in a low resource setting. Our aim was to evaluate whether an educational intervention would improve women's knowledge and confidence in the Self-HPV method. Women aged between 25 and 65 years old, eligible for cervical cancer screening, were randomly chosen to receive standard information (control group) or standard information followed by educational intervention (interventional group). Standard information included explanations about what the test detects (HPV), the link between HPV and cervical cancer and how to perform HPV self-sampling. The educational intervention consisted of a culturally tailored video about HPV, cervical cancer, Self-HPV and its relevancy as a screening test. All participants completed a questionnaire that assessed sociodemographic data, women's knowledge about cervical cancer and acceptability of Self-HPV. A total of 302 women were enrolled in 4 health care centers in Yaoundé and the surrounding countryside. 301 women (149 in the "control group" and 152 in the "intervention group") completed the full process and were included into the analysis. Participants who received the educational intervention had a significantly higher knowledge about HPV and cervical cancer than the control group (pEducational intervention promotes an increase in knowledge about HPV and cervical cancer. Further investigation should be conducted to determine if this intervention can be sustained beyond the short term and influences screening behavior. International Standard Randomised Controlled Trial Number (ISRCTN) Register ISRCTN78123709.

  9. A review of regression procedures for randomized response data, including univariate and multivariate logistic regression, the proportional odds model and item response model, and self-protective responses

    NARCIS (Netherlands)

    Cruyff, M.; Böckenholt, U.; van der Heijden, P.G.M.; Frank, L.E.

    2016-01-01

    In survey research, it is often problematic to ask people sensitive questions because they may refuse to answer or they may provide a socially desirable answer that does not reveal their true status on the sensitive question. To solve this problem Warner (1965) proposed randomized response (RR).

  10. Study protocol for a randomized controlled trial for anterior inguinal hernia repair: transrectus sheath preperitoneal mesh repair compared to transinguinal preperitoneal procedure

    NARCIS (Netherlands)

    Prins, M.W.; Koning, G.G.; Keus, E.; Vriens, P.W.H.E.; Mollen, R.M.H.G.; Akkersdijk, W.L.; Laarhoven, C.J. van

    2013-01-01

    BACKGROUND: Anterior open treatment of the inguinal hernia with a tension-free mesh has reduced the incidence of hernia recurrence. The Lichtenstein procedure is the current reference technique for inguinal hernia treatment. Chronic pain has become the main postoperative complication after surgical

  11. Evaluation of aesthetics of implant-supported single-tooth replacements using different bone augmentation procedures : A prospective randomized clinical study

    NARCIS (Netherlands)

    Meijndert, Leo; Meijer, Henny J. A.; Stellingsma, Kees; Stegenga, Boudewijn; Raghoebar, Gerry M.

    2007-01-01

    Objectives: The aim of this study was to evaluate the aesthetics of implant-supported single-tooth replacements using different augmentation procedures in a prospective study with the use of an objective rating index and with a subjective patient questionnaire, and to compare the results with each

  12. Dataset - Evaluation of Standardized Sample Collection, Packaging, and Decontamination Procedures to Assess Cross-Contamination Potential during Bacillus anthracis Incident Response Operations

    Data.gov (United States)

    U.S. Environmental Protection Agency — Spore recovery data during sample packaging decontamination tests. This dataset is associated with the following publication: Calfee, W., J. Tufts, K. Meyer, K....

  13. Selection of representative calibration samp